net/packet/af_packet.c

   1 /*
   2  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   3  *              operating system.  INET is implemented using the  BSD Socket
   4  *              interface as the means of communication with the user level.
   5  *
   6  *              PACKET - implements raw packet sockets.
   7  *
   8  * Authors:     Ross Biro
   9  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  10  *              Alan Cox, <gw4pts@gw4pts.ampr.org>
  11  *
  12  * Fixes:
  13  *              Alan Cox        :       verify_area() now used correctly
  14  *              Alan Cox        :       new skbuff lists, look ma no backlogs!
  15  *              Alan Cox        :       tidied skbuff lists.
  16  *              Alan Cox        :       Now uses generic datagram routines I
  17  *                                      added. Also fixed the peek/read crash
  18  *                                      from all old Linux datagram code.
  19  *              Alan Cox        :       Uses the improved datagram code.
  20  *              Alan Cox        :       Added NULL's for socket options.
  21  *              Alan Cox        :       Re-commented the code.
  22  *              Alan Cox        :       Use new kernel side addressing
  23  *              Rob Janssen     :       Correct MTU usage.
  24  *              Dave Platt      :       Counter leaks caused by incorrect
  25  *                                      interrupt locking and some slightly
  26  *                                      dubious gcc output. Can you read
  27  *                                      compiler: it said _VOLATILE_
  28  *      Richard Kooijman        :       Timestamp fixes.
  29  *              Alan Cox        :       New buffers. Use sk->mac.raw.
  30  *              Alan Cox        :       sendmsg/recvmsg support.
  31  *              Alan Cox        :       Protocol setting support
  32  *      Alexey Kuznetsov        :       Untied from IPv4 stack.
  33  *      Cyrus Durgin            :       Fixed kerneld for kmod.
  34  *      Michal Ostrowski        :       Module initialization cleanup.
  35  *         Ulises Alonso        :       Frame number limit removal and
  36  *                                      packet_set_ring memory leak.
  37  *              Eric Biederman  :       Allow for > 8 byte hardware addresses.
  38  *                                      The convention is that longer addresses
  39  *                                      will simply extend the hardware address
  40  *                                      byte arrays at the end of sockaddr_ll
  41  *                                      and packet_mreq.
  42  *              Johann Baudy    :       Added TX RING.
  43  *              Chetan Loke     :       Implemented TPACKET_V3 block abstraction
  44  *                                      layer.
  45  *                                      Copyright (C) 2011, <lokec@ccs.neu.edu>
  46  *
  47  *
  48  *              This program is free software; you can redistribute it and/or
  49  *              modify it under the terms of the GNU General Public License
  50  *              as published by the Free Software Foundation; either version
  51  *              2 of the License, or (at your option) any later version.
  52  *
  53  */
  54
  55 #include <linux/types.h>
  56 #include <linux/mm.h>
  57 #include <linux/capability.h>
  58 #include <linux/fcntl.h>
  59 #include <linux/socket.h>
  60 #include <linux/in.h>
  61 #include <linux/inet.h>
  62 #include <linux/netdevice.h>
  63 #include <linux/if_packet.h>
  64 #include <linux/wireless.h>
  65 #include <linux/kernel.h>
  66 #include <linux/kmod.h>
  67 #include <linux/slab.h>
  68 #include <linux/vmalloc.h>
  69 #include <net/net_namespace.h>
  70 #include <net/ip.h>
  71 #include <net/protocol.h>
  72 #include <linux/skbuff.h>
  73 #include <net/sock.h>
  74 #include <linux/errno.h>
  75 #include <linux/timer.h>
  76 #include <linux/uaccess.h>
  77 #include <asm/ioctls.h>
  78 #include <asm/page.h>
  79 #include <asm/cacheflush.h>
  80 #include <asm/io.h>
  81 #include <linux/proc_fs.h>
  82 #include <linux/seq_file.h>
  83 #include <linux/poll.h>
  84 #include <linux/module.h>
  85 #include <linux/init.h>
  86 #include <linux/mutex.h>
  87 #include <linux/if_vlan.h>
  88 #include <linux/virtio_net.h>
  89 #include <linux/errqueue.h>
  90 #include <linux/net_tstamp.h>
  91 #include <linux/percpu.h>
  92 #ifdef CONFIG_INET
  93 #include <net/inet_common.h>
  94 #endif
  95 #include <linux/bpf.h>
  96 #include <net/compat.h>
  97
  98 #include "internal.h"
  99
 100 /*
 101    Assumptions:
 102    - if device has no dev->hard_header routine, it adds and removes ll header
 103      inside itself. In this case ll header is invisible outside of device,
 104      but higher levels still should reserve dev->hard_header_len.
 105      Some devices are enough clever to reallocate skb, when header
 106      will not fit to reserved space (tunnel), another ones are silly
 107      (PPP).
 108    - packet socket receives packets with pulled ll header,
 109      so that SOCK_RAW should push it back.
 110
 111 On receive:
 112 -----------
 113
 114 Incoming, dev->hard_header!=NULL
 115    mac_header -> ll header
 116    data       -> data
 117
 118 Outgoing, dev->hard_header!=NULL
 119    mac_header -> ll header
 120    data       -> ll header
 121
 122 Incoming, dev->hard_header==NULL
 123    mac_header -> UNKNOWN position. It is very likely, that it points to ll
 124                  header.  PPP makes it, that is wrong, because introduce
 125                  assymetry between rx and tx paths.
 126    data       -> data
 127
 128 Outgoing, dev->hard_header==NULL
 129    mac_header -> data. ll header is still not built!
 130    data       -> data
 131
 132 Resume
 133   If dev->hard_header==NULL we are unlikely to restore sensible ll header.
 134
 135
 136 On transmit:
 137 ------------
 138
 139 dev->hard_header != NULL
 140    mac_header -> ll header
 141    data       -> ll header
 142
 143 dev->hard_header == NULL (ll header is added by device, we cannot control it)
 144    mac_header -> data
 145    data       -> data
 146
 147    We should set nh.raw on output to correct posistion,
 148    packet classifier depends on it.
 149  */
 150
 151 /* Private packet socket structures. */
 152
 153 /* identical to struct packet_mreq except it has
 154  * a longer address field.
 155  */
 156 struct packet_mreq_max {
 157         int             mr_ifindex;
 158         unsigned short  mr_type;
 159         unsigned short  mr_alen;
 160         unsigned char   mr_address[MAX_ADDR_LEN];
 161 };
 162
 163 union tpacket_uhdr {
 164         struct tpacket_hdr  *h1;
 165         struct tpacket2_hdr *h2;
 166         struct tpacket3_hdr *h3;
 167         void *raw;
 168 };
 169
 170 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 171                 int closing, int tx_ring);
 172
 173 #define V3_ALIGNMENT    (8)
 174
 175 #define BLK_HDR_LEN     (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
 176
 177 #define BLK_PLUS_PRIV(sz_of_priv) \
 178         (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
 179
 180 #define PGV_FROM_VMALLOC 1
 181
 182 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
 183 #define BLOCK_NUM_PKTS(x)       ((x)->hdr.bh1.num_pkts)
 184 #define BLOCK_O2FP(x)           ((x)->hdr.bh1.offset_to_first_pkt)
 185 #define BLOCK_LEN(x)            ((x)->hdr.bh1.blk_len)
 186 #define BLOCK_SNUM(x)           ((x)->hdr.bh1.seq_num)
 187 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
 188 #define BLOCK_PRIV(x)           ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
 189
 190 struct packet_sock;
 191 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
 192 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
 193                        struct packet_type *pt, struct net_device *orig_dev);
 194
 195 static void *packet_previous_frame(struct packet_sock *po,
 196                 struct packet_ring_buffer *rb,
 197                 int status);
 198 static void packet_increment_head(struct packet_ring_buffer *buff);
 199 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
 200                         struct tpacket_block_desc *);
 201 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
 202                         struct packet_sock *);
 203 static void prb_retire_current_block(struct tpacket_kbdq_core *,
 204                 struct packet_sock *, unsigned int status);
 205 static int prb_queue_frozen(struct tpacket_kbdq_core *);
 206 static void prb_open_block(struct tpacket_kbdq_core *,
 207                 struct tpacket_block_desc *);
 208 static void prb_retire_rx_blk_timer_expired(unsigned long);
 209 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
 210 static void prb_init_blk_timer(struct packet_sock *,
 211                 struct tpacket_kbdq_core *,
 212                 void (*func) (unsigned long));
 213 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
 214 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
 215                 struct tpacket3_hdr *);
 216 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
 217                 struct tpacket3_hdr *);
 218 static void packet_flush_mclist(struct sock *sk);
 219
 220 struct packet_skb_cb {
 221         union {
 222                 struct sockaddr_pkt pkt;
 223                 union {
 224                         /* Trick: alias skb original length with
 225                          * ll.sll_family and ll.protocol in order
 226                          * to save room.
 227                          */
 228                         unsigned int origlen;
 229                         struct sockaddr_ll ll;
 230                 };
 231         } sa;
 232 };
 233
 234 #define vio_le() virtio_legacy_is_little_endian()
 235
 236 #define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
 237
 238 #define GET_PBDQC_FROM_RB(x)    ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
 239 #define GET_PBLOCK_DESC(x, bid) \
 240         ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
 241 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x)       \
 242         ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
 243 #define GET_NEXT_PRB_BLK_NUM(x) \
 244         (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
 245         ((x)->kactive_blk_num+1) : 0)
 246
 247 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
 248 static void __fanout_link(struct sock *sk, struct packet_sock *po);
 249
 250 static int packet_direct_xmit(struct sk_buff *skb)
 251 {
 252         struct net_device *dev = skb->dev;
 253         struct sk_buff *orig_skb = skb;
 254         struct netdev_queue *txq;
 255         int ret = NETDEV_TX_BUSY;
 256
 257         if (unlikely(!netif_running(dev) ||
 258                      !netif_carrier_ok(dev)))
 259                 goto drop;
 260
 261         skb = validate_xmit_skb_list(skb, dev);
 262         if (skb != orig_skb)
 263                 goto drop;
 264
 265         txq = skb_get_tx_queue(dev, skb);
 266
 267         local_bh_disable();
 268
 269         HARD_TX_LOCK(dev, txq, smp_processor_id());
 270         if (!netif_xmit_frozen_or_drv_stopped(txq))
 271                 ret = netdev_start_xmit(skb, dev, txq, false);
 272         HARD_TX_UNLOCK(dev, txq);
 273
 274         local_bh_enable();
 275
 276         if (!dev_xmit_complete(ret))
 277                 kfree_skb(skb);
 278
 279         return ret;
 280 drop:
 281         atomic_long_inc(&dev->tx_dropped);
 282         kfree_skb_list(skb);
 283         return NET_XMIT_DROP;
 284 }
 285
 286 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
 287 {
 288         struct net_device *dev;
 289
 290         rcu_read_lock();
 291         dev = rcu_dereference(po->cached_dev);
 292         if (likely(dev))
 293                 dev_hold(dev);
 294         rcu_read_unlock();
 295
 296         return dev;
 297 }
 298
 299 static void packet_cached_dev_assign(struct packet_sock *po,
 300                                      struct net_device *dev)
 301 {
 302         rcu_assign_pointer(po->cached_dev, dev);
 303 }
 304
 305 static void packet_cached_dev_reset(struct packet_sock *po)
 306 {
 307         RCU_INIT_POINTER(po->cached_dev, NULL);
 308 }
 309
 310 static bool packet_use_direct_xmit(const struct packet_sock *po)
 311 {
 312         return po->xmit == packet_direct_xmit;
 313 }
 314
 315 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
 316 {
 317         return (u16) raw_smp_processor_id() % dev->real_num_tx_queues;
 318 }
 319
 320 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
 321 {
 322         const struct net_device_ops *ops = dev->netdev_ops;
 323         u16 queue_index;
 324
 325         if (ops->ndo_select_queue) {
 326                 queue_index = ops->ndo_select_queue(dev, skb, NULL,
 327                                                     __packet_pick_tx_queue);
 328                 queue_index = netdev_cap_txqueue(dev, queue_index);
 329         } else {
 330                 queue_index = __packet_pick_tx_queue(dev, skb);
 331         }
 332
 333         skb_set_queue_mapping(skb, queue_index);
 334 }
 335
 336 /* register_prot_hook must be invoked with the po->bind_lock held,
 337  * or from a context in which asynchronous accesses to the packet
 338  * socket is not possible (packet_create()).
 339  */
 340 static void register_prot_hook(struct sock *sk)
 341 {
 342         struct packet_sock *po = pkt_sk(sk);
 343
 344         if (!po->running) {
 345                 if (po->fanout)
 346                         __fanout_link(sk, po);
 347                 else
 348                         dev_add_pack(&po->prot_hook);
 349
 350                 sock_hold(sk);
 351                 po->running = 1;
 352         }
 353 }
 354
 355 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
 356  * held.   If the sync parameter is true, we will temporarily drop
 357  * the po->bind_lock and do a synchronize_net to make sure no
 358  * asynchronous packet processing paths still refer to the elements
 359  * of po->prot_hook.  If the sync parameter is false, it is the
 360  * callers responsibility to take care of this.
 361  */
 362 static void __unregister_prot_hook(struct sock *sk, bool sync)
 363 {
 364         struct packet_sock *po = pkt_sk(sk);
 365
 366         po->running = 0;
 367
 368         if (po->fanout)
 369                 __fanout_unlink(sk, po);
 370         else
 371                 __dev_remove_pack(&po->prot_hook);
 372
 373         __sock_put(sk);
 374
 375         if (sync) {
 376                 spin_unlock(&po->bind_lock);
 377                 synchronize_net();
 378                 spin_lock(&po->bind_lock);
 379         }
 380 }
 381
 382 static void unregister_prot_hook(struct sock *sk, bool sync)
 383 {
 384         struct packet_sock *po = pkt_sk(sk);
 385
 386         if (po->running)
 387                 __unregister_prot_hook(sk, sync);
 388 }
 389
 390 static inline struct page * __pure pgv_to_page(void *addr)
 391 {
 392         if (is_vmalloc_addr(addr))
 393                 return vmalloc_to_page(addr);
 394         return virt_to_page(addr);
 395 }
 396
 397 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
 398 {
 399         union tpacket_uhdr h;
 400
 401         h.raw = frame;
 402         switch (po->tp_version) {
 403         case TPACKET_V1:
 404                 h.h1->tp_status = status;
 405                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 406                 break;
 407         case TPACKET_V2:
 408                 h.h2->tp_status = status;
 409                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 410                 break;
 411         case TPACKET_V3:
 412                 h.h3->tp_status = status;
 413                 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
 414                 break;
 415         default:
 416                 WARN(1, "TPACKET version not supported.\n");
 417                 BUG();
 418         }
 419
 420         smp_wmb();
 421 }
 422
 423 static int __packet_get_status(struct packet_sock *po, void *frame)
 424 {
 425         union tpacket_uhdr h;
 426
 427         smp_rmb();
 428
 429         h.raw = frame;
 430         switch (po->tp_version) {
 431         case TPACKET_V1:
 432                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 433                 return h.h1->tp_status;
 434         case TPACKET_V2:
 435                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 436                 return h.h2->tp_status;
 437         case TPACKET_V3:
 438                 flush_dcache_page(pgv_to_page(&h.h3->tp_status));
 439                 return h.h3->tp_status;
 440         default:
 441                 WARN(1, "TPACKET version not supported.\n");
 442                 BUG();
 443                 return 0;
 444         }
 445 }
 446
 447 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
 448                                    unsigned int flags)
 449 {
 450         struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
 451
 452         if (shhwtstamps &&
 453             (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
 454             ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
 455                 return TP_STATUS_TS_RAW_HARDWARE;
 456
 457         if (ktime_to_timespec_cond(skb->tstamp, ts))
 458                 return TP_STATUS_TS_SOFTWARE;
 459
 460         return 0;
 461 }
 462
 463 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
 464                                     struct sk_buff *skb)
 465 {
 466         union tpacket_uhdr h;
 467         struct timespec ts;
 468         __u32 ts_status;
 469
 470         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
 471                 return 0;
 472
 473         h.raw = frame;
 474         switch (po->tp_version) {
 475         case TPACKET_V1:
 476                 h.h1->tp_sec = ts.tv_sec;
 477                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
 478                 break;
 479         case TPACKET_V2:
 480                 h.h2->tp_sec = ts.tv_sec;
 481                 h.h2->tp_nsec = ts.tv_nsec;
 482                 break;
 483         case TPACKET_V3:
 484                 h.h3->tp_sec = ts.tv_sec;
 485                 h.h3->tp_nsec = ts.tv_nsec;
 486                 break;
 487         default:
 488                 WARN(1, "TPACKET version not supported.\n");
 489                 BUG();
 490         }
 491
 492         /* one flush is safe, as both fields always lie on the same cacheline */
 493         flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
 494         smp_wmb();
 495
 496         return ts_status;
 497 }
 498
 499 static void *packet_lookup_frame(struct packet_sock *po,
 500                 struct packet_ring_buffer *rb,
 501                 unsigned int position,
 502                 int status)
 503 {
 504         unsigned int pg_vec_pos, frame_offset;
 505         union tpacket_uhdr h;
 506
 507         pg_vec_pos = position / rb->frames_per_block;
 508         frame_offset = position % rb->frames_per_block;
 509
 510         h.raw = rb->pg_vec[pg_vec_pos].buffer +
 511                 (frame_offset * rb->frame_size);
 512
 513         if (status != __packet_get_status(po, h.raw))
 514                 return NULL;
 515
 516         return h.raw;
 517 }
 518
 519 static void *packet_current_frame(struct packet_sock *po,
 520                 struct packet_ring_buffer *rb,
 521                 int status)
 522 {
 523         return packet_lookup_frame(po, rb, rb->head, status);
 524 }
 525
 526 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 527 {
 528         del_timer_sync(&pkc->retire_blk_timer);
 529 }
 530
 531 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
 532                 struct sk_buff_head *rb_queue)
 533 {
 534         struct tpacket_kbdq_core *pkc;
 535
 536         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 537
 538         spin_lock_bh(&rb_queue->lock);
 539         pkc->delete_blk_timer = 1;
 540         spin_unlock_bh(&rb_queue->lock);
 541
 542         prb_del_retire_blk_timer(pkc);
 543 }
 544
 545 static void prb_init_blk_timer(struct packet_sock *po,
 546                 struct tpacket_kbdq_core *pkc,
 547                 void (*func) (unsigned long))
 548 {
 549         init_timer(&pkc->retire_blk_timer);
 550         pkc->retire_blk_timer.data = (long)po;
 551         pkc->retire_blk_timer.function = func;
 552         pkc->retire_blk_timer.expires = jiffies;
 553 }
 554
 555 static void prb_setup_retire_blk_timer(struct packet_sock *po)
 556 {
 557         struct tpacket_kbdq_core *pkc;
 558
 559         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 560         prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
 561 }
 562
 563 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
 564                                 int blk_size_in_bytes)
 565 {
 566         struct net_device *dev;
 567         unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
 568         struct ethtool_link_ksettings ecmd;
 569         int err;
 570
 571         rtnl_lock();
 572         dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
 573         if (unlikely(!dev)) {
 574                 rtnl_unlock();
 575                 return DEFAULT_PRB_RETIRE_TOV;
 576         }
 577         err = __ethtool_get_link_ksettings(dev, &ecmd);
 578         rtnl_unlock();
 579         if (!err) {
 580                 /*
 581                  * If the link speed is so slow you don't really
 582                  * need to worry about perf anyways
 583                  */
 584                 if (ecmd.base.speed < SPEED_1000 ||
 585                     ecmd.base.speed == SPEED_UNKNOWN) {
 586                         return DEFAULT_PRB_RETIRE_TOV;
 587                 } else {
 588                         msec = 1;
 589                         div = ecmd.base.speed / 1000;
 590                 }
 591         }
 592
 593         mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
 594
 595         if (div)
 596                 mbits /= div;
 597
 598         tmo = mbits * msec;
 599
 600         if (div)
 601                 return tmo+1;
 602         return tmo;
 603 }
 604
 605 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
 606                         union tpacket_req_u *req_u)
 607 {
 608         p1->feature_req_word = req_u->req3.tp_feature_req_word;
 609 }
 610
 611 static void init_prb_bdqc(struct packet_sock *po,
 612                         struct packet_ring_buffer *rb,
 613                         struct pgv *pg_vec,
 614                         union tpacket_req_u *req_u)
 615 {
 616         struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
 617         struct tpacket_block_desc *pbd;
 618
 619         memset(p1, 0x0, sizeof(*p1));
 620
 621         p1->knxt_seq_num = 1;
 622         p1->pkbdq = pg_vec;
 623         pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
 624         p1->pkblk_start = pg_vec[0].buffer;
 625         p1->kblk_size = req_u->req3.tp_block_size;
 626         p1->knum_blocks = req_u->req3.tp_block_nr;
 627         p1->hdrlen = po->tp_hdrlen;
 628         p1->version = po->tp_version;
 629         p1->last_kactive_blk_num = 0;
 630         po->stats.stats3.tp_freeze_q_cnt = 0;
 631         if (req_u->req3.tp_retire_blk_tov)
 632                 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
 633         else
 634                 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
 635                                                 req_u->req3.tp_block_size);
 636         p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
 637         p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
 638
 639         p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
 640         prb_init_ft_ops(p1, req_u);
 641         prb_setup_retire_blk_timer(po);
 642         prb_open_block(p1, pbd);
 643 }
 644
 645 /*  Do NOT update the last_blk_num first.
 646  *  Assumes sk_buff_head lock is held.
 647  */
 648 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 649 {
 650         mod_timer(&pkc->retire_blk_timer,
 651                         jiffies + pkc->tov_in_jiffies);
 652         pkc->last_kactive_blk_num = pkc->kactive_blk_num;
 653 }
 654
 655 /*
 656  * Timer logic:
 657  * 1) We refresh the timer only when we open a block.
 658  *    By doing this we don't waste cycles refreshing the timer
 659  *        on packet-by-packet basis.
 660  *
 661  * With a 1MB block-size, on a 1Gbps line, it will take
 662  * i) ~8 ms to fill a block + ii) memcpy etc.
 663  * In this cut we are not accounting for the memcpy time.
 664  *
 665  * So, if the user sets the 'tmo' to 10ms then the timer
 666  * will never fire while the block is still getting filled
 667  * (which is what we want). However, the user could choose
 668  * to close a block early and that's fine.
 669  *
 670  * But when the timer does fire, we check whether or not to refresh it.
 671  * Since the tmo granularity is in msecs, it is not too expensive
 672  * to refresh the timer, lets say every '8' msecs.
 673  * Either the user can set the 'tmo' or we can derive it based on
 674  * a) line-speed and b) block-size.
 675  * prb_calc_retire_blk_tmo() calculates the tmo.
 676  *
 677  */
 678 static void prb_retire_rx_blk_timer_expired(unsigned long data)
 679 {
 680         struct packet_sock *po = (struct packet_sock *)data;
 681         struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 682         unsigned int frozen;
 683         struct tpacket_block_desc *pbd;
 684
 685         spin_lock(&po->sk.sk_receive_queue.lock);
 686
 687         frozen = prb_queue_frozen(pkc);
 688         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 689
 690         if (unlikely(pkc->delete_blk_timer))
 691                 goto out;
 692
 693         /* We only need to plug the race when the block is partially filled.
 694          * tpacket_rcv:
 695          *              lock(); increment BLOCK_NUM_PKTS; unlock()
 696          *              copy_bits() is in progress ...
 697          *              timer fires on other cpu:
 698          *              we can't retire the current block because copy_bits
 699          *              is in progress.
 700          *
 701          */
 702         if (BLOCK_NUM_PKTS(pbd)) {
 703                 while (atomic_read(&pkc->blk_fill_in_prog)) {
 704                         /* Waiting for skb_copy_bits to finish... */
 705                         cpu_relax();
 706                 }
 707         }
 708
 709         if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
 710                 if (!frozen) {
 711                         if (!BLOCK_NUM_PKTS(pbd)) {
 712                                 /* An empty block. Just refresh the timer. */
 713                                 goto refresh_timer;
 714                         }
 715                         prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
 716                         if (!prb_dispatch_next_block(pkc, po))
 717                                 goto refresh_timer;
 718                         else
 719                                 goto out;
 720                 } else {
 721                         /* Case 1. Queue was frozen because user-space was
 722                          *         lagging behind.
 723                          */
 724                         if (prb_curr_blk_in_use(pkc, pbd)) {
 725                                 /*
 726                                  * Ok, user-space is still behind.
 727                                  * So just refresh the timer.
 728                                  */
 729                                 goto refresh_timer;
 730                         } else {
 731                                /* Case 2. queue was frozen,user-space caught up,
 732                                 * now the link went idle && the timer fired.
 733                                 * We don't have a block to close.So we open this
 734                                 * block and restart the timer.
 735                                 * opening a block thaws the queue,restarts timer
 736                                 * Thawing/timer-refresh is a side effect.
 737                                 */
 738                                 prb_open_block(pkc, pbd);
 739                                 goto out;
 740                         }
 741                 }
 742         }
 743
 744 refresh_timer:
 745         _prb_refresh_rx_retire_blk_timer(pkc);
 746
 747 out:
 748         spin_unlock(&po->sk.sk_receive_queue.lock);
 749 }
 750
 751 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
 752                 struct tpacket_block_desc *pbd1, __u32 status)
 753 {
 754         /* Flush everything minus the block header */
 755
 756 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 757         u8 *start, *end;
 758
 759         start = (u8 *)pbd1;
 760
 761         /* Skip the block header(we know header WILL fit in 4K) */
 762         start += PAGE_SIZE;
 763
 764         end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
 765         for (; start < end; start += PAGE_SIZE)
 766                 flush_dcache_page(pgv_to_page(start));
 767
 768         smp_wmb();
 769 #endif
 770
 771         /* Now update the block status. */
 772
 773         BLOCK_STATUS(pbd1) = status;
 774
 775         /* Flush the block header */
 776
 777 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 778         start = (u8 *)pbd1;
 779         flush_dcache_page(pgv_to_page(start));
 780
 781         smp_wmb();
 782 #endif
 783 }
 784
 785 /*
 786  * Side effect:
 787  *
 788  * 1) flush the block
 789  * 2) Increment active_blk_num
 790  *
 791  * Note:We DONT refresh the timer on purpose.
 792  *      Because almost always the next block will be opened.
 793  */
 794 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
 795                 struct tpacket_block_desc *pbd1,
 796                 struct packet_sock *po, unsigned int stat)
 797 {
 798         __u32 status = TP_STATUS_USER | stat;
 799
 800         struct tpacket3_hdr *last_pkt;
 801         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 802         struct sock *sk = &po->sk;
 803
 804         if (po->stats.stats3.tp_drops)
 805                 status |= TP_STATUS_LOSING;
 806
 807         last_pkt = (struct tpacket3_hdr *)pkc1->prev;
 808         last_pkt->tp_next_offset = 0;
 809
 810         /* Get the ts of the last pkt */
 811         if (BLOCK_NUM_PKTS(pbd1)) {
 812                 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
 813                 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
 814         } else {
 815                 /* Ok, we tmo'd - so get the current time.
 816                  *
 817                  * It shouldn't really happen as we don't close empty
 818                  * blocks. See prb_retire_rx_blk_timer_expired().
 819                  */
 820                 struct timespec ts;
 821                 getnstimeofday(&ts);
 822                 h1->ts_last_pkt.ts_sec = ts.tv_sec;
 823                 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
 824         }
 825
 826         smp_wmb();
 827
 828         /* Flush the block */
 829         prb_flush_block(pkc1, pbd1, status);
 830
 831         sk->sk_data_ready(sk);
 832
 833         pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
 834 }
 835
 836 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
 837 {
 838         pkc->reset_pending_on_curr_blk = 0;
 839 }
 840
 841 /*
 842  * Side effect of opening a block:
 843  *
 844  * 1) prb_queue is thawed.
 845  * 2) retire_blk_timer is refreshed.
 846  *
 847  */
 848 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
 849         struct tpacket_block_desc *pbd1)
 850 {
 851         struct timespec ts;
 852         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 853
 854         smp_rmb();
 855
 856         /* We could have just memset this but we will lose the
 857          * flexibility of making the priv area sticky
 858          */
 859
 860         BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
 861         BLOCK_NUM_PKTS(pbd1) = 0;
 862         BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 863
 864         getnstimeofday(&ts);
 865
 866         h1->ts_first_pkt.ts_sec = ts.tv_sec;
 867         h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
 868
 869         pkc1->pkblk_start = (char *)pbd1;
 870         pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 871
 872         BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 873         BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
 874
 875         pbd1->version = pkc1->version;
 876         pkc1->prev = pkc1->nxt_offset;
 877         pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
 878
 879         prb_thaw_queue(pkc1);
 880         _prb_refresh_rx_retire_blk_timer(pkc1);
 881
 882         smp_wmb();
 883 }
 884
 885 /*
 886  * Queue freeze logic:
 887  * 1) Assume tp_block_nr = 8 blocks.
 888  * 2) At time 't0', user opens Rx ring.
 889  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
 890  * 4) user-space is either sleeping or processing block '0'.
 891  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
 892  *    it will close block-7,loop around and try to fill block '0'.
 893  *    call-flow:
 894  *    __packet_lookup_frame_in_block
 895  *      prb_retire_current_block()
 896  *      prb_dispatch_next_block()
 897  *        |->(BLOCK_STATUS == USER) evaluates to true
 898  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
 899  * 6) Now there are two cases:
 900  *    6.1) Link goes idle right after the queue is frozen.
 901  *         But remember, the last open_block() refreshed the timer.
 902  *         When this timer expires,it will refresh itself so that we can
 903  *         re-open block-0 in near future.
 904  *    6.2) Link is busy and keeps on receiving packets. This is a simple
 905  *         case and __packet_lookup_frame_in_block will check if block-0
 906  *         is free and can now be re-used.
 907  */
 908 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
 909                                   struct packet_sock *po)
 910 {
 911         pkc->reset_pending_on_curr_blk = 1;
 912         po->stats.stats3.tp_freeze_q_cnt++;
 913 }
 914
 915 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
 916
 917 /*
 918  * If the next block is free then we will dispatch it
 919  * and return a good offset.
 920  * Else, we will freeze the queue.
 921  * So, caller must check the return value.
 922  */
 923 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
 924                 struct packet_sock *po)
 925 {
 926         struct tpacket_block_desc *pbd;
 927
 928         smp_rmb();
 929
 930         /* 1. Get current block num */
 931         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 932
 933         /* 2. If this block is currently in_use then freeze the queue */
 934         if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
 935                 prb_freeze_queue(pkc, po);
 936                 return NULL;
 937         }
 938
 939         /*
 940          * 3.
 941          * open this block and return the offset where the first packet
 942          * needs to get stored.
 943          */
 944         prb_open_block(pkc, pbd);
 945         return (void *)pkc->nxt_offset;
 946 }
 947
 948 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
 949                 struct packet_sock *po, unsigned int status)
 950 {
 951         struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 952
 953         /* retire/close the current block */
 954         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
 955                 /*
 956                  * Plug the case where copy_bits() is in progress on
 957                  * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
 958                  * have space to copy the pkt in the current block and
 959                  * called prb_retire_current_block()
 960                  *
 961                  * We don't need to worry about the TMO case because
 962                  * the timer-handler already handled this case.
 963                  */
 964                 if (!(status & TP_STATUS_BLK_TMO)) {
 965                         while (atomic_read(&pkc->blk_fill_in_prog)) {
 966                                 /* Waiting for skb_copy_bits to finish... */
 967                                 cpu_relax();
 968                         }
 969                 }
 970                 prb_close_block(pkc, pbd, po, status);
 971                 return;
 972         }
 973 }
 974
 975 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
 976                                       struct tpacket_block_desc *pbd)
 977 {
 978         return TP_STATUS_USER & BLOCK_STATUS(pbd);
 979 }
 980
 981 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
 982 {
 983         return pkc->reset_pending_on_curr_blk;
 984 }
 985
 986 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
 987 {
 988         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
 989         atomic_dec(&pkc->blk_fill_in_prog);
 990 }
 991
 992 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
 993                         struct tpacket3_hdr *ppd)
 994 {
 995         ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
 996 }
 997
 998 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
 999                         struct tpacket3_hdr *ppd)
1000 {
1001         ppd->hv1.tp_rxhash = 0;
1002 }
1003
1004 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
1005                         struct tpacket3_hdr *ppd)
1006 {
1007         if (skb_vlan_tag_present(pkc->skb)) {
1008                 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1009                 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1010                 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1011         } else {
1012                 ppd->hv1.tp_vlan_tci = 0;
1013                 ppd->hv1.tp_vlan_tpid = 0;
1014                 ppd->tp_status = TP_STATUS_AVAILABLE;
1015         }
1016 }
1017
1018 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1019                         struct tpacket3_hdr *ppd)
1020 {
1021         ppd->hv1.tp_padding = 0;
1022         prb_fill_vlan_info(pkc, ppd);
1023
1024         if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1025                 prb_fill_rxhash(pkc, ppd);
1026         else
1027                 prb_clear_rxhash(pkc, ppd);
1028 }
1029
1030 static void prb_fill_curr_block(char *curr,
1031                                 struct tpacket_kbdq_core *pkc,
1032                                 struct tpacket_block_desc *pbd,
1033                                 unsigned int len)
1034 {
1035         struct tpacket3_hdr *ppd;
1036
1037         ppd  = (struct tpacket3_hdr *)curr;
1038         ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1039         pkc->prev = curr;
1040         pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1041         BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1042         BLOCK_NUM_PKTS(pbd) += 1;
1043         atomic_inc(&pkc->blk_fill_in_prog);
1044         prb_run_all_ft_ops(pkc, ppd);
1045 }
1046
1047 /* Assumes caller has the sk->rx_queue.lock */
1048 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1049                                             struct sk_buff *skb,
1050                                                 int status,
1051                                             unsigned int len
1052                                             )
1053 {
1054         struct tpacket_kbdq_core *pkc;
1055         struct tpacket_block_desc *pbd;
1056         char *curr, *end;
1057
1058         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1059         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1060
1061         /* Queue is frozen when user space is lagging behind */
1062         if (prb_queue_frozen(pkc)) {
1063                 /*
1064                  * Check if that last block which caused the queue to freeze,
1065                  * is still in_use by user-space.
1066                  */
1067                 if (prb_curr_blk_in_use(pkc, pbd)) {
1068                         /* Can't record this packet */
1069                         return NULL;
1070                 } else {
1071                         /*
1072                          * Ok, the block was released by user-space.
1073                          * Now let's open that block.
1074                          * opening a block also thaws the queue.
1075                          * Thawing is a side effect.
1076                          */
1077                         prb_open_block(pkc, pbd);
1078                 }
1079         }
1080
1081         smp_mb();
1082         curr = pkc->nxt_offset;
1083         pkc->skb = skb;
1084         end = (char *)pbd + pkc->kblk_size;
1085
1086         /* first try the current block */
1087         if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1088                 prb_fill_curr_block(curr, pkc, pbd, len);
1089                 return (void *)curr;
1090         }
1091
1092         /* Ok, close the current block */
1093         prb_retire_current_block(pkc, po, 0);
1094
1095         /* Now, try to dispatch the next block */
1096         curr = (char *)prb_dispatch_next_block(pkc, po);
1097         if (curr) {
1098                 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1099                 prb_fill_curr_block(curr, pkc, pbd, len);
1100                 return (void *)curr;
1101         }
1102
1103         /*
1104          * No free blocks are available.user_space hasn't caught up yet.
1105          * Queue was just frozen and now this packet will get dropped.
1106          */
1107         return NULL;
1108 }
1109
1110 static void *packet_current_rx_frame(struct packet_sock *po,
1111                                             struct sk_buff *skb,
1112                                             int status, unsigned int len)
1113 {
1114         char *curr = NULL;
1115         switch (po->tp_version) {
1116         case TPACKET_V1:
1117         case TPACKET_V2:
1118                 curr = packet_lookup_frame(po, &po->rx_ring,
1119                                         po->rx_ring.head, status);
1120                 return curr;
1121         case TPACKET_V3:
1122                 return __packet_lookup_frame_in_block(po, skb, status, len);
1123         default:
1124                 WARN(1, "TPACKET version not supported\n");
1125                 BUG();
1126                 return NULL;
1127         }
1128 }
1129
1130 static void *prb_lookup_block(struct packet_sock *po,
1131                                      struct packet_ring_buffer *rb,
1132                                      unsigned int idx,
1133                                      int status)
1134 {
1135         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1136         struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1137
1138         if (status != BLOCK_STATUS(pbd))
1139                 return NULL;
1140         return pbd;
1141 }
1142
1143 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1144 {
1145         unsigned int prev;
1146         if (rb->prb_bdqc.kactive_blk_num)
1147                 prev = rb->prb_bdqc.kactive_blk_num-1;
1148         else
1149                 prev = rb->prb_bdqc.knum_blocks-1;
1150         return prev;
1151 }
1152
1153 /* Assumes caller has held the rx_queue.lock */
1154 static void *__prb_previous_block(struct packet_sock *po,
1155                                          struct packet_ring_buffer *rb,
1156                                          int status)
1157 {
1158         unsigned int previous = prb_previous_blk_num(rb);
1159         return prb_lookup_block(po, rb, previous, status);
1160 }
1161
1162 static void *packet_previous_rx_frame(struct packet_sock *po,
1163                                              struct packet_ring_buffer *rb,
1164                                              int status)
1165 {
1166         if (po->tp_version <= TPACKET_V2)
1167                 return packet_previous_frame(po, rb, status);
1168
1169         return __prb_previous_block(po, rb, status);
1170 }
1171
1172 static void packet_increment_rx_head(struct packet_sock *po,
1173                                             struct packet_ring_buffer *rb)
1174 {
1175         switch (po->tp_version) {
1176         case TPACKET_V1:
1177         case TPACKET_V2:
1178                 return packet_increment_head(rb);
1179         case TPACKET_V3:
1180         default:
1181                 WARN(1, "TPACKET version not supported.\n");
1182                 BUG();
1183                 return;
1184         }
1185 }
1186
1187 static void *packet_previous_frame(struct packet_sock *po,
1188                 struct packet_ring_buffer *rb,
1189                 int status)
1190 {
1191         unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1192         return packet_lookup_frame(po, rb, previous, status);
1193 }
1194
1195 static void packet_increment_head(struct packet_ring_buffer *buff)
1196 {
1197         buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1198 }
1199
1200 static void packet_inc_pending(struct packet_ring_buffer *rb)
1201 {
1202         this_cpu_inc(*rb->pending_refcnt);
1203 }
1204
1205 static void packet_dec_pending(struct packet_ring_buffer *rb)
1206 {
1207         this_cpu_dec(*rb->pending_refcnt);
1208 }
1209
1210 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1211 {
1212         unsigned int refcnt = 0;
1213         int cpu;
1214
1215         /* We don't use pending refcount in rx_ring. */
1216         if (rb->pending_refcnt == NULL)
1217                 return 0;
1218
1219         for_each_possible_cpu(cpu)
1220                 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1221
1222         return refcnt;
1223 }
1224
1225 static int packet_alloc_pending(struct packet_sock *po)
1226 {
1227         po->rx_ring.pending_refcnt = NULL;
1228
1229         po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1230         if (unlikely(po->tx_ring.pending_refcnt == NULL))
1231                 return -ENOBUFS;
1232
1233         return 0;
1234 }
1235
1236 static void packet_free_pending(struct packet_sock *po)
1237 {
1238         free_percpu(po->tx_ring.pending_refcnt);
1239 }
1240
1241 #define ROOM_POW_OFF    2
1242 #define ROOM_NONE       0x0
1243 #define ROOM_LOW        0x1
1244 #define ROOM_NORMAL     0x2
1245
1246 static bool __tpacket_has_room(struct packet_sock *po, int pow_off)
1247 {
1248         int idx, len;
1249
1250         len = po->rx_ring.frame_max + 1;
1251         idx = po->rx_ring.head;
1252         if (pow_off)
1253                 idx += len >> pow_off;
1254         if (idx >= len)
1255                 idx -= len;
1256         return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1257 }
1258
1259 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off)
1260 {
1261         int idx, len;
1262
1263         len = po->rx_ring.prb_bdqc.knum_blocks;
1264         idx = po->rx_ring.prb_bdqc.kactive_blk_num;
1265         if (pow_off)
1266                 idx += len >> pow_off;
1267         if (idx >= len)
1268                 idx -= len;
1269         return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1270 }
1271
1272 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1273 {
1274         struct sock *sk = &po->sk;
1275         int ret = ROOM_NONE;
1276
1277         if (po->prot_hook.func != tpacket_rcv) {
1278                 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1279                                           - (skb ? skb->truesize : 0);
1280                 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF))
1281                         return ROOM_NORMAL;
1282                 else if (avail > 0)
1283                         return ROOM_LOW;
1284                 else
1285                         return ROOM_NONE;
1286         }
1287
1288         if (po->tp_version == TPACKET_V3) {
1289                 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1290                         ret = ROOM_NORMAL;
1291                 else if (__tpacket_v3_has_room(po, 0))
1292                         ret = ROOM_LOW;
1293         } else {
1294                 if (__tpacket_has_room(po, ROOM_POW_OFF))
1295                         ret = ROOM_NORMAL;
1296                 else if (__tpacket_has_room(po, 0))
1297                         ret = ROOM_LOW;
1298         }
1299
1300         return ret;
1301 }
1302
1303 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1304 {
1305         int ret;
1306         bool has_room;
1307
1308         spin_lock_bh(&po->sk.sk_receive_queue.lock);
1309         ret = __packet_rcv_has_room(po, skb);
1310         has_room = ret == ROOM_NORMAL;
1311         if (po->pressure == has_room)
1312                 po->pressure = !has_room;
1313         spin_unlock_bh(&po->sk.sk_receive_queue.lock);
1314
1315         return ret;
1316 }
1317
1318 static void packet_sock_destruct(struct sock *sk)
1319 {
1320         skb_queue_purge(&sk->sk_error_queue);
1321
1322         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1323         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1324
1325         if (!sock_flag(sk, SOCK_DEAD)) {
1326                 pr_err("Attempt to release alive packet socket: %p\n", sk);
1327                 return;
1328         }
1329
1330         sk_refcnt_debug_dec(sk);
1331 }
1332
1333 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1334 {
1335         u32 rxhash;
1336         int i, count = 0;
1337
1338         rxhash = skb_get_hash(skb);
1339         for (i = 0; i < ROLLOVER_HLEN; i++)
1340                 if (po->rollover->history[i] == rxhash)
1341                         count++;
1342
1343         po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1344         return count > (ROLLOVER_HLEN >> 1);
1345 }
1346
1347 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1348                                       struct sk_buff *skb,
1349                                       unsigned int num)
1350 {
1351         return reciprocal_scale(__skb_get_hash_symmetric(skb), num);
1352 }
1353
1354 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1355                                     struct sk_buff *skb,
1356                                     unsigned int num)
1357 {
1358         unsigned int val = atomic_inc_return(&f->rr_cur);
1359
1360         return val % num;
1361 }
1362
1363 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1364                                      struct sk_buff *skb,
1365                                      unsigned int num)
1366 {
1367         return smp_processor_id() % num;
1368 }
1369
1370 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1371                                      struct sk_buff *skb,
1372                                      unsigned int num)
1373 {
1374         return prandom_u32_max(num);
1375 }
1376
1377 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1378                                           struct sk_buff *skb,
1379                                           unsigned int idx, bool try_self,
1380                                           unsigned int num)
1381 {
1382         struct packet_sock *po, *po_next, *po_skip = NULL;
1383         unsigned int i, j, room = ROOM_NONE;
1384
1385         po = pkt_sk(f->arr[idx]);
1386
1387         if (try_self) {
1388                 room = packet_rcv_has_room(po, skb);
1389                 if (room == ROOM_NORMAL ||
1390                     (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1391                         return idx;
1392                 po_skip = po;
1393         }
1394
1395         i = j = min_t(int, po->rollover->sock, num - 1);
1396         do {
1397                 po_next = pkt_sk(f->arr[i]);
1398                 if (po_next != po_skip && !po_next->pressure &&
1399                     packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1400                         if (i != j)
1401                                 po->rollover->sock = i;
1402                         atomic_long_inc(&po->rollover->num);
1403                         if (room == ROOM_LOW)
1404                                 atomic_long_inc(&po->rollover->num_huge);
1405                         return i;
1406                 }
1407
1408                 if (++i == num)
1409                         i = 0;
1410         } while (i != j);
1411
1412         atomic_long_inc(&po->rollover->num_failed);
1413         return idx;
1414 }
1415
1416 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1417                                     struct sk_buff *skb,
1418                                     unsigned int num)
1419 {
1420         return skb_get_queue_mapping(skb) % num;
1421 }
1422
1423 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1424                                      struct sk_buff *skb,
1425                                      unsigned int num)
1426 {
1427         struct bpf_prog *prog;
1428         unsigned int ret = 0;
1429
1430         rcu_read_lock();
1431         prog = rcu_dereference(f->bpf_prog);
1432         if (prog)
1433                 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1434         rcu_read_unlock();
1435
1436         return ret;
1437 }
1438
1439 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1440 {
1441         return f->flags & (flag >> 8);
1442 }
1443
1444 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1445                              struct packet_type *pt, struct net_device *orig_dev)
1446 {
1447         struct packet_fanout *f = pt->af_packet_priv;
1448         unsigned int num = READ_ONCE(f->num_members);
1449         struct net *net = read_pnet(&f->net);
1450         struct packet_sock *po;
1451         unsigned int idx;
1452
1453         if (!net_eq(dev_net(dev), net) || !num) {
1454                 kfree_skb(skb);
1455                 return 0;
1456         }
1457
1458         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1459                 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1460                 if (!skb)
1461                         return 0;
1462         }
1463         switch (f->type) {
1464         case PACKET_FANOUT_HASH:
1465         default:
1466                 idx = fanout_demux_hash(f, skb, num);
1467                 break;
1468         case PACKET_FANOUT_LB:
1469                 idx = fanout_demux_lb(f, skb, num);
1470                 break;
1471         case PACKET_FANOUT_CPU:
1472                 idx = fanout_demux_cpu(f, skb, num);
1473                 break;
1474         case PACKET_FANOUT_RND:
1475                 idx = fanout_demux_rnd(f, skb, num);
1476                 break;
1477         case PACKET_FANOUT_QM:
1478                 idx = fanout_demux_qm(f, skb, num);
1479                 break;
1480         case PACKET_FANOUT_ROLLOVER:
1481                 idx = fanout_demux_rollover(f, skb, 0, false, num);
1482                 break;
1483         case PACKET_FANOUT_CBPF:
1484         case PACKET_FANOUT_EBPF:
1485                 idx = fanout_demux_bpf(f, skb, num);
1486                 break;
1487         }
1488
1489         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1490                 idx = fanout_demux_rollover(f, skb, idx, true, num);
1491
1492         po = pkt_sk(f->arr[idx]);
1493         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1494 }
1495
1496 DEFINE_MUTEX(fanout_mutex);
1497 EXPORT_SYMBOL_GPL(fanout_mutex);
1498 static LIST_HEAD(fanout_list);
1499
1500 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1501 {
1502         struct packet_fanout *f = po->fanout;
1503
1504         spin_lock(&f->lock);
1505         f->arr[f->num_members] = sk;
1506         smp_wmb();
1507         f->num_members++;
1508         if (f->num_members == 1)
1509                 dev_add_pack(&f->prot_hook);
1510         spin_unlock(&f->lock);
1511 }
1512
1513 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1514 {
1515         struct packet_fanout *f = po->fanout;
1516         int i;
1517
1518         spin_lock(&f->lock);
1519         for (i = 0; i < f->num_members; i++) {
1520                 if (f->arr[i] == sk)
1521                         break;
1522         }
1523         BUG_ON(i >= f->num_members);
1524         f->arr[i] = f->arr[f->num_members - 1];
1525         f->num_members--;
1526         if (f->num_members == 0)
1527                 __dev_remove_pack(&f->prot_hook);
1528         spin_unlock(&f->lock);
1529 }
1530
1531 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1532 {
1533         if (sk->sk_family != PF_PACKET)
1534                 return false;
1535
1536         return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1537 }
1538
1539 static void fanout_init_data(struct packet_fanout *f)
1540 {
1541         switch (f->type) {
1542         case PACKET_FANOUT_LB:
1543                 atomic_set(&f->rr_cur, 0);
1544                 break;
1545         case PACKET_FANOUT_CBPF:
1546         case PACKET_FANOUT_EBPF:
1547                 RCU_INIT_POINTER(f->bpf_prog, NULL);
1548                 break;
1549         }
1550 }
1551
1552 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1553 {
1554         struct bpf_prog *old;
1555
1556         spin_lock(&f->lock);
1557         old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1558         rcu_assign_pointer(f->bpf_prog, new);
1559         spin_unlock(&f->lock);
1560
1561         if (old) {
1562                 synchronize_net();
1563                 bpf_prog_destroy(old);
1564         }
1565 }
1566
1567 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1568                                 unsigned int len)
1569 {
1570         struct bpf_prog *new;
1571         struct sock_fprog fprog;
1572         int ret;
1573
1574         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1575                 return -EPERM;
1576         if (len != sizeof(fprog))
1577                 return -EINVAL;
1578         if (copy_from_user(&fprog, data, len))
1579                 return -EFAULT;
1580
1581         ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1582         if (ret)
1583                 return ret;
1584
1585         __fanout_set_data_bpf(po->fanout, new);
1586         return 0;
1587 }
1588
1589 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1590                                 unsigned int len)
1591 {
1592         struct bpf_prog *new;
1593         u32 fd;
1594
1595         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1596                 return -EPERM;
1597         if (len != sizeof(fd))
1598                 return -EINVAL;
1599         if (copy_from_user(&fd, data, len))
1600                 return -EFAULT;
1601
1602         new = bpf_prog_get_type(fd, BPF_PROG_TYPE_SOCKET_FILTER);
1603         if (IS_ERR(new))
1604                 return PTR_ERR(new);
1605
1606         __fanout_set_data_bpf(po->fanout, new);
1607         return 0;
1608 }
1609
1610 static int fanout_set_data(struct packet_sock *po, char __user *data,
1611                            unsigned int len)
1612 {
1613         switch (po->fanout->type) {
1614         case PACKET_FANOUT_CBPF:
1615                 return fanout_set_data_cbpf(po, data, len);
1616         case PACKET_FANOUT_EBPF:
1617                 return fanout_set_data_ebpf(po, data, len);
1618         default:
1619                 return -EINVAL;
1620         };
1621 }
1622
1623 static void fanout_release_data(struct packet_fanout *f)
1624 {
1625         switch (f->type) {
1626         case PACKET_FANOUT_CBPF:
1627         case PACKET_FANOUT_EBPF:
1628                 __fanout_set_data_bpf(f, NULL);
1629         };
1630 }
1631
1632 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1633 {
1634         struct packet_rollover *rollover = NULL;
1635         struct packet_sock *po = pkt_sk(sk);
1636         struct packet_fanout *f, *match;
1637         u8 type = type_flags & 0xff;
1638         u8 flags = type_flags >> 8;
1639         int err;
1640
1641         switch (type) {
1642         case PACKET_FANOUT_ROLLOVER:
1643                 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1644                         return -EINVAL;
1645         case PACKET_FANOUT_HASH:
1646         case PACKET_FANOUT_LB:
1647         case PACKET_FANOUT_CPU:
1648         case PACKET_FANOUT_RND:
1649         case PACKET_FANOUT_QM:
1650         case PACKET_FANOUT_CBPF:
1651         case PACKET_FANOUT_EBPF:
1652                 break;
1653         default:
1654                 return -EINVAL;
1655         }
1656
1657         mutex_lock(&fanout_mutex);
1658
1659         err = -EINVAL;
1660         if (!po->running)
1661                 goto out;
1662
1663         err = -EALREADY;
1664         if (po->fanout)
1665                 goto out;
1666
1667         if (type == PACKET_FANOUT_ROLLOVER ||
1668             (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1669                 err = -ENOMEM;
1670                 rollover = kzalloc(sizeof(*rollover), GFP_KERNEL);
1671                 if (!rollover)
1672                         goto out;
1673                 atomic_long_set(&rollover->num, 0);
1674                 atomic_long_set(&rollover->num_huge, 0);
1675                 atomic_long_set(&rollover->num_failed, 0);
1676                 po->rollover = rollover;
1677         }
1678
1679         match = NULL;
1680         list_for_each_entry(f, &fanout_list, list) {
1681                 if (f->id == id &&
1682                     read_pnet(&f->net) == sock_net(sk)) {
1683                         match = f;
1684                         break;
1685                 }
1686         }
1687         err = -EINVAL;
1688         if (match && match->flags != flags)
1689                 goto out;
1690         if (!match) {
1691                 err = -ENOMEM;
1692                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1693                 if (!match)
1694                         goto out;
1695                 write_pnet(&match->net, sock_net(sk));
1696                 match->id = id;
1697                 match->type = type;
1698                 match->flags = flags;
1699                 INIT_LIST_HEAD(&match->list);
1700                 spin_lock_init(&match->lock);
1701                 atomic_set(&match->sk_ref, 0);
1702                 fanout_init_data(match);
1703                 match->prot_hook.type = po->prot_hook.type;
1704                 match->prot_hook.dev = po->prot_hook.dev;
1705                 match->prot_hook.func = packet_rcv_fanout;
1706                 match->prot_hook.af_packet_priv = match;
1707                 match->prot_hook.id_match = match_fanout_group;
1708                 list_add(&match->list, &fanout_list);
1709         }
1710         err = -EINVAL;
1711         if (match->type == type &&
1712             match->prot_hook.type == po->prot_hook.type &&
1713             match->prot_hook.dev == po->prot_hook.dev) {
1714                 err = -ENOSPC;
1715                 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1716                         __dev_remove_pack(&po->prot_hook);
1717                         po->fanout = match;
1718                         atomic_inc(&match->sk_ref);
1719                         __fanout_link(sk, po);
1720                         err = 0;
1721                 }
1722         }
1723 out:
1724         if (err && rollover) {
1725                 kfree(rollover);
1726                 po->rollover = NULL;
1727         }
1728         mutex_unlock(&fanout_mutex);
1729         return err;
1730 }
1731
1732 /* If pkt_sk(sk)->fanout->sk_ref is zero, this function removes
1733  * pkt_sk(sk)->fanout from fanout_list and returns pkt_sk(sk)->fanout.
1734  * It is the responsibility of the caller to call fanout_release_data() and
1735  * free the returned packet_fanout (after synchronize_net())
1736  */
1737 static struct packet_fanout *fanout_release(struct sock *sk)
1738 {
1739         struct packet_sock *po = pkt_sk(sk);
1740         struct packet_fanout *f;
1741
1742         mutex_lock(&fanout_mutex);
1743         f = po->fanout;
1744         if (f) {
1745                 po->fanout = NULL;
1746
1747                 if (atomic_dec_and_test(&f->sk_ref))
1748                         list_del(&f->list);
1749                 else
1750                         f = NULL;
1751
1752                 if (po->rollover)
1753                         kfree_rcu(po->rollover, rcu);
1754         }
1755         mutex_unlock(&fanout_mutex);
1756
1757         return f;
1758 }
1759
1760 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1761                                           struct sk_buff *skb)
1762 {
1763         /* Earlier code assumed this would be a VLAN pkt, double-check
1764          * this now that we have the actual packet in hand. We can only
1765          * do this check on Ethernet devices.
1766          */
1767         if (unlikely(dev->type != ARPHRD_ETHER))
1768                 return false;
1769
1770         skb_reset_mac_header(skb);
1771         return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1772 }
1773
1774 static const struct proto_ops packet_ops;
1775
1776 static const struct proto_ops packet_ops_spkt;
1777
1778 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1779                            struct packet_type *pt, struct net_device *orig_dev)
1780 {
1781         struct sock *sk;
1782         struct sockaddr_pkt *spkt;
1783
1784         /*
1785          *      When we registered the protocol we saved the socket in the data
1786          *      field for just this event.
1787          */
1788
1789         sk = pt->af_packet_priv;
1790
1791         /*
1792          *      Yank back the headers [hope the device set this
1793          *      right or kerboom...]
1794          *
1795          *      Incoming packets have ll header pulled,
1796          *      push it back.
1797          *
1798          *      For outgoing ones skb->data == skb_mac_header(skb)
1799          *      so that this procedure is noop.
1800          */
1801
1802         if (skb->pkt_type == PACKET_LOOPBACK)
1803                 goto out;
1804
1805         if (!net_eq(dev_net(dev), sock_net(sk)))
1806                 goto out;
1807
1808         skb = skb_share_check(skb, GFP_ATOMIC);
1809         if (skb == NULL)
1810                 goto oom;
1811
1812         /* drop any routing info */
1813         skb_dst_drop(skb);
1814
1815         /* drop conntrack reference */
1816         nf_reset(skb);
1817
1818         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1819
1820         skb_push(skb, skb->data - skb_mac_header(skb));
1821
1822         /*
1823          *      The SOCK_PACKET socket receives _all_ frames.
1824          */
1825
1826         spkt->spkt_family = dev->type;
1827         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1828         spkt->spkt_protocol = skb->protocol;
1829
1830         /*
1831          *      Charge the memory to the socket. This is done specifically
1832          *      to prevent sockets using all the memory up.
1833          */
1834
1835         if (sock_queue_rcv_skb(sk, skb) == 0)
1836                 return 0;
1837
1838 out:
1839         kfree_skb(skb);
1840 oom:
1841         return 0;
1842 }
1843
1844
1845 /*
1846  *      Output a raw packet to a device layer. This bypasses all the other
1847  *      protocol layers and you must therefore supply it with a complete frame
1848  */
1849
1850 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1851                                size_t len)
1852 {
1853         struct sock *sk = sock->sk;
1854         DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1855         struct sk_buff *skb = NULL;
1856         struct net_device *dev;
1857         struct sockcm_cookie sockc;
1858         __be16 proto = 0;
1859         int err;
1860         int extra_len = 0;
1861
1862         /*
1863          *      Get and verify the address.
1864          */
1865
1866         if (saddr) {
1867                 if (msg->msg_namelen < sizeof(struct sockaddr))
1868                         return -EINVAL;
1869                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1870                         proto = saddr->spkt_protocol;
1871         } else
1872                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1873
1874         /*
1875          *      Find the device first to size check it
1876          */
1877
1878         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1879 retry:
1880         rcu_read_lock();
1881         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1882         err = -ENODEV;
1883         if (dev == NULL)
1884                 goto out_unlock;
1885
1886         err = -ENETDOWN;
1887         if (!(dev->flags & IFF_UP))
1888                 goto out_unlock;
1889
1890         /*
1891          * You may not queue a frame bigger than the mtu. This is the lowest level
1892          * raw protocol and you must do your own fragmentation at this level.
1893          */
1894
1895         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1896                 if (!netif_supports_nofcs(dev)) {
1897                         err = -EPROTONOSUPPORT;
1898                         goto out_unlock;
1899                 }
1900                 extra_len = 4; /* We're doing our own CRC */
1901         }
1902
1903         err = -EMSGSIZE;
1904         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1905                 goto out_unlock;
1906
1907         if (!skb) {
1908                 size_t reserved = LL_RESERVED_SPACE(dev);
1909                 int tlen = dev->needed_tailroom;
1910                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1911
1912                 rcu_read_unlock();
1913                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1914                 if (skb == NULL)
1915                         return -ENOBUFS;
1916                 /* FIXME: Save some space for broken drivers that write a hard
1917                  * header at transmission time by themselves. PPP is the notable
1918                  * one here. This should really be fixed at the driver level.
1919                  */
1920                 skb_reserve(skb, reserved);
1921                 skb_reset_network_header(skb);
1922
1923                 /* Try to align data part correctly */
1924                 if (hhlen) {
1925                         skb->data -= hhlen;
1926                         skb->tail -= hhlen;
1927                         if (len < hhlen)
1928                                 skb_reset_network_header(skb);
1929                 }
1930                 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1931                 if (err)
1932                         goto out_free;
1933                 goto retry;
1934         }
1935
1936         if (!dev_validate_header(dev, skb->data, len)) {
1937                 err = -EINVAL;
1938                 goto out_unlock;
1939         }
1940         if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1941             !packet_extra_vlan_len_allowed(dev, skb)) {
1942                 err = -EMSGSIZE;
1943                 goto out_unlock;
1944         }
1945
1946         sockc.tsflags = sk->sk_tsflags;
1947         if (msg->msg_controllen) {
1948                 err = sock_cmsg_send(sk, msg, &sockc);
1949                 if (unlikely(err))
1950                         goto out_unlock;
1951         }
1952
1953         skb->protocol = proto;
1954         skb->dev = dev;
1955         skb->priority = sk->sk_priority;
1956         skb->mark = sk->sk_mark;
1957
1958         sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags);
1959
1960         if (unlikely(extra_len == 4))
1961                 skb->no_fcs = 1;
1962
1963         skb_probe_transport_header(skb, 0);
1964
1965         dev_queue_xmit(skb);
1966         rcu_read_unlock();
1967         return len;
1968
1969 out_unlock:
1970         rcu_read_unlock();
1971 out_free:
1972         kfree_skb(skb);
1973         return err;
1974 }
1975
1976 static unsigned int run_filter(struct sk_buff *skb,
1977                                const struct sock *sk,
1978                                unsigned int res)
1979 {
1980         struct sk_filter *filter;
1981
1982         rcu_read_lock();
1983         filter = rcu_dereference(sk->sk_filter);
1984         if (filter != NULL)
1985                 res = bpf_prog_run_clear_cb(filter->prog, skb);
1986         rcu_read_unlock();
1987
1988         return res;
1989 }
1990
1991 static int packet_rcv_vnet(struct msghdr *msg, const struct sk_buff *skb,
1992                            size_t *len)
1993 {
1994         struct virtio_net_hdr vnet_hdr;
1995
1996         if (*len < sizeof(vnet_hdr))
1997                 return -EINVAL;
1998         *len -= sizeof(vnet_hdr);
1999
2000         if (virtio_net_hdr_from_skb(skb, &vnet_hdr, vio_le(), true))
2001                 return -EINVAL;
2002
2003         return memcpy_to_msg(msg, (void *)&vnet_hdr, sizeof(vnet_hdr));
2004 }
2005
2006 /*
2007  * This function makes lazy skb cloning in hope that most of packets
2008  * are discarded by BPF.
2009  *
2010  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
2011  * and skb->cb are mangled. It works because (and until) packets
2012  * falling here are owned by current CPU. Output packets are cloned
2013  * by dev_queue_xmit_nit(), input packets are processed by net_bh
2014  * sequencially, so that if we return skb to original state on exit,
2015  * we will not harm anyone.
2016  */
2017
2018 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
2019                       struct packet_type *pt, struct net_device *orig_dev)
2020 {
2021         struct sock *sk;
2022         struct sockaddr_ll *sll;
2023         struct packet_sock *po;
2024         u8 *skb_head = skb->data;
2025         int skb_len = skb->len;
2026         unsigned int snaplen, res;
2027         bool is_drop_n_account = false;
2028
2029         if (skb->pkt_type == PACKET_LOOPBACK)
2030                 goto drop;
2031
2032         sk = pt->af_packet_priv;
2033         po = pkt_sk(sk);
2034
2035         if (!net_eq(dev_net(dev), sock_net(sk)))
2036                 goto drop;
2037
2038         skb->dev = dev;
2039
2040         if (dev->header_ops) {
2041                 /* The device has an explicit notion of ll header,
2042                  * exported to higher levels.
2043                  *
2044                  * Otherwise, the device hides details of its frame
2045                  * structure, so that corresponding packet head is
2046                  * never delivered to user.
2047                  */
2048                 if (sk->sk_type != SOCK_DGRAM)
2049                         skb_push(skb, skb->data - skb_mac_header(skb));
2050                 else if (skb->pkt_type == PACKET_OUTGOING) {
2051                         /* Special case: outgoing packets have ll header at head */
2052                         skb_pull(skb, skb_network_offset(skb));
2053                 }
2054         }
2055
2056         snaplen = skb->len;
2057
2058         res = run_filter(skb, sk, snaplen);
2059         if (!res)
2060                 goto drop_n_restore;
2061         if (snaplen > res)
2062                 snaplen = res;
2063
2064         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2065                 goto drop_n_acct;
2066
2067         if (skb_shared(skb)) {
2068                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2069                 if (nskb == NULL)
2070                         goto drop_n_acct;
2071
2072                 if (skb_head != skb->data) {
2073                         skb->data = skb_head;
2074                         skb->len = skb_len;
2075                 }
2076                 consume_skb(skb);
2077                 skb = nskb;
2078         }
2079
2080         sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2081
2082         sll = &PACKET_SKB_CB(skb)->sa.ll;
2083         sll->sll_hatype = dev->type;
2084         sll->sll_pkttype = skb->pkt_type;
2085         if (unlikely(po->origdev))
2086                 sll->sll_ifindex = orig_dev->ifindex;
2087         else
2088                 sll->sll_ifindex = dev->ifindex;
2089
2090         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2091
2092         /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2093          * Use their space for storing the original skb length.
2094          */
2095         PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2096
2097         if (pskb_trim(skb, snaplen))
2098                 goto drop_n_acct;
2099
2100         skb_set_owner_r(skb, sk);
2101         skb->dev = NULL;
2102         skb_dst_drop(skb);
2103
2104         /* drop conntrack reference */
2105         nf_reset(skb);
2106
2107         spin_lock(&sk->sk_receive_queue.lock);
2108         po->stats.stats1.tp_packets++;
2109         sock_skb_set_dropcount(sk, skb);
2110         __skb_queue_tail(&sk->sk_receive_queue, skb);
2111         spin_unlock(&sk->sk_receive_queue.lock);
2112         sk->sk_data_ready(sk);
2113         return 0;
2114
2115 drop_n_acct:
2116         is_drop_n_account = true;
2117         spin_lock(&sk->sk_receive_queue.lock);
2118         po->stats.stats1.tp_drops++;
2119         atomic_inc(&sk->sk_drops);
2120         spin_unlock(&sk->sk_receive_queue.lock);
2121
2122 drop_n_restore:
2123         if (skb_head != skb->data && skb_shared(skb)) {
2124                 skb->data = skb_head;
2125                 skb->len = skb_len;
2126         }
2127 drop:
2128         if (!is_drop_n_account)
2129                 consume_skb(skb);
2130         else
2131                 kfree_skb(skb);
2132         return 0;
2133 }
2134
2135 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2136                        struct packet_type *pt, struct net_device *orig_dev)
2137 {
2138         struct sock *sk;
2139         struct packet_sock *po;
2140         struct sockaddr_ll *sll;
2141         union tpacket_uhdr h;
2142         u8 *skb_head = skb->data;
2143         int skb_len = skb->len;
2144         unsigned int snaplen, res;
2145         unsigned long status = TP_STATUS_USER;
2146         unsigned short macoff, netoff, hdrlen;
2147         struct sk_buff *copy_skb = NULL;
2148         struct timespec ts;
2149         __u32 ts_status;
2150         bool is_drop_n_account = false;
2151
2152         /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2153          * We may add members to them until current aligned size without forcing
2154          * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2155          */
2156         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2157         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2158
2159         if (skb->pkt_type == PACKET_LOOPBACK)
2160                 goto drop;
2161
2162         sk = pt->af_packet_priv;
2163         po = pkt_sk(sk);
2164
2165         if (!net_eq(dev_net(dev), sock_net(sk)))
2166                 goto drop;
2167
2168         if (dev->header_ops) {
2169                 if (sk->sk_type != SOCK_DGRAM)
2170                         skb_push(skb, skb->data - skb_mac_header(skb));
2171                 else if (skb->pkt_type == PACKET_OUTGOING) {
2172                         /* Special case: outgoing packets have ll header at head */
2173                         skb_pull(skb, skb_network_offset(skb));
2174                 }
2175         }
2176
2177         snaplen = skb->len;
2178
2179         res = run_filter(skb, sk, snaplen);
2180         if (!res)
2181                 goto drop_n_restore;
2182
2183         if (skb->ip_summed == CHECKSUM_PARTIAL)
2184                 status |= TP_STATUS_CSUMNOTREADY;
2185         else if (skb->pkt_type != PACKET_OUTGOING &&
2186                  (skb->ip_summed == CHECKSUM_COMPLETE ||
2187                   skb_csum_unnecessary(skb)))
2188                 status |= TP_STATUS_CSUM_VALID;
2189
2190         if (snaplen > res)
2191                 snaplen = res;
2192
2193         if (sk->sk_type == SOCK_DGRAM) {
2194                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2195                                   po->tp_reserve;
2196         } else {
2197                 unsigned int maclen = skb_network_offset(skb);
2198                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2199                                        (maclen < 16 ? 16 : maclen)) +
2200                                        po->tp_reserve;
2201                 if (po->has_vnet_hdr)
2202                         netoff += sizeof(struct virtio_net_hdr);
2203                 macoff = netoff - maclen;
2204         }
2205         if (po->tp_version <= TPACKET_V2) {
2206                 if (macoff + snaplen > po->rx_ring.frame_size) {
2207                         if (po->copy_thresh &&
2208                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2209                                 if (skb_shared(skb)) {
2210                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
2211                                 } else {
2212                                         copy_skb = skb_get(skb);
2213                                         skb_head = skb->data;
2214                                 }
2215                                 if (copy_skb)
2216                                         skb_set_owner_r(copy_skb, sk);
2217                         }
2218                         snaplen = po->rx_ring.frame_size - macoff;
2219                         if ((int)snaplen < 0)
2220                                 snaplen = 0;
2221                 }
2222         } else if (unlikely(macoff + snaplen >
2223                             GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2224                 u32 nval;
2225
2226                 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2227                 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2228                             snaplen, nval, macoff);
2229                 snaplen = nval;
2230                 if (unlikely((int)snaplen < 0)) {
2231                         snaplen = 0;
2232                         macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2233                 }
2234         }
2235         spin_lock(&sk->sk_receive_queue.lock);
2236         h.raw = packet_current_rx_frame(po, skb,
2237                                         TP_STATUS_KERNEL, (macoff+snaplen));
2238         if (!h.raw)
2239                 goto drop_n_account;
2240         if (po->tp_version <= TPACKET_V2) {
2241                 packet_increment_rx_head(po, &po->rx_ring);
2242         /*
2243          * LOSING will be reported till you read the stats,
2244          * because it's COR - Clear On Read.
2245          * Anyways, moving it for V1/V2 only as V3 doesn't need this
2246          * at packet level.
2247          */
2248                 if (po->stats.stats1.tp_drops)
2249                         status |= TP_STATUS_LOSING;
2250         }
2251         po->stats.stats1.tp_packets++;
2252         if (copy_skb) {
2253                 status |= TP_STATUS_COPY;
2254                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2255         }
2256         spin_unlock(&sk->sk_receive_queue.lock);
2257
2258         if (po->has_vnet_hdr) {
2259                 if (virtio_net_hdr_from_skb(skb, h.raw + macoff -
2260                                             sizeof(struct virtio_net_hdr),
2261                                             vio_le(), true)) {
2262                         spin_lock(&sk->sk_receive_queue.lock);
2263                         goto drop_n_account;
2264                 }
2265         }
2266
2267         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2268
2269         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2270                 getnstimeofday(&ts);
2271
2272         status |= ts_status;
2273
2274         switch (po->tp_version) {
2275         case TPACKET_V1:
2276                 h.h1->tp_len = skb->len;
2277                 h.h1->tp_snaplen = snaplen;
2278                 h.h1->tp_mac = macoff;
2279                 h.h1->tp_net = netoff;
2280                 h.h1->tp_sec = ts.tv_sec;
2281                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2282                 hdrlen = sizeof(*h.h1);
2283                 break;
2284         case TPACKET_V2:
2285                 h.h2->tp_len = skb->len;
2286                 h.h2->tp_snaplen = snaplen;
2287                 h.h2->tp_mac = macoff;
2288                 h.h2->tp_net = netoff;
2289                 h.h2->tp_sec = ts.tv_sec;
2290                 h.h2->tp_nsec = ts.tv_nsec;
2291                 if (skb_vlan_tag_present(skb)) {
2292                         h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2293                         h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2294                         status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2295                 } else {
2296                         h.h2->tp_vlan_tci = 0;
2297                         h.h2->tp_vlan_tpid = 0;
2298                 }
2299                 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2300                 hdrlen = sizeof(*h.h2);
2301                 break;
2302         case TPACKET_V3:
2303                 /* tp_nxt_offset,vlan are already populated above.
2304                  * So DONT clear those fields here
2305                  */
2306                 h.h3->tp_status |= status;
2307                 h.h3->tp_len = skb->len;
2308                 h.h3->tp_snaplen = snaplen;
2309                 h.h3->tp_mac = macoff;
2310                 h.h3->tp_net = netoff;
2311                 h.h3->tp_sec  = ts.tv_sec;
2312                 h.h3->tp_nsec = ts.tv_nsec;
2313                 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2314                 hdrlen = sizeof(*h.h3);
2315                 break;
2316         default:
2317                 BUG();
2318         }
2319
2320         sll = h.raw + TPACKET_ALIGN(hdrlen);
2321         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2322         sll->sll_family = AF_PACKET;
2323         sll->sll_hatype = dev->type;
2324         sll->sll_protocol = skb->protocol;
2325         sll->sll_pkttype = skb->pkt_type;
2326         if (unlikely(po->origdev))
2327                 sll->sll_ifindex = orig_dev->ifindex;
2328         else
2329                 sll->sll_ifindex = dev->ifindex;
2330
2331         smp_mb();
2332
2333 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2334         if (po->tp_version <= TPACKET_V2) {
2335                 u8 *start, *end;
2336
2337                 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2338                                         macoff + snaplen);
2339
2340                 for (start = h.raw; start < end; start += PAGE_SIZE)
2341                         flush_dcache_page(pgv_to_page(start));
2342         }
2343         smp_wmb();
2344 #endif
2345
2346         if (po->tp_version <= TPACKET_V2) {
2347                 __packet_set_status(po, h.raw, status);
2348                 sk->sk_data_ready(sk);
2349         } else {
2350                 prb_clear_blk_fill_status(&po->rx_ring);
2351         }
2352
2353 drop_n_restore:
2354         if (skb_head != skb->data && skb_shared(skb)) {
2355                 skb->data = skb_head;
2356                 skb->len = skb_len;
2357         }
2358 drop:
2359         if (!is_drop_n_account)
2360                 consume_skb(skb);
2361         else
2362                 kfree_skb(skb);
2363         return 0;
2364
2365 drop_n_account:
2366         is_drop_n_account = true;
2367         po->stats.stats1.tp_drops++;
2368         spin_unlock(&sk->sk_receive_queue.lock);
2369
2370         sk->sk_data_ready(sk);
2371         kfree_skb(copy_skb);
2372         goto drop_n_restore;
2373 }
2374
2375 static void tpacket_destruct_skb(struct sk_buff *skb)
2376 {
2377         struct packet_sock *po = pkt_sk(skb->sk);
2378
2379         if (likely(po->tx_ring.pg_vec)) {
2380                 void *ph;
2381                 __u32 ts;
2382
2383                 ph = skb_shinfo(skb)->destructor_arg;
2384                 packet_dec_pending(&po->tx_ring);
2385
2386                 ts = __packet_set_timestamp(po, ph, skb);
2387                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2388         }
2389
2390         sock_wfree(skb);
2391 }
2392
2393 static void tpacket_set_protocol(const struct net_device *dev,
2394                                  struct sk_buff *skb)
2395 {
2396         if (dev->type == ARPHRD_ETHER) {
2397                 skb_reset_mac_header(skb);
2398                 skb->protocol = eth_hdr(skb)->h_proto;
2399         }
2400 }
2401
2402 static int __packet_snd_vnet_parse(struct virtio_net_hdr *vnet_hdr, size_t len)
2403 {
2404         if ((vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2405             (__virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2406              __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2 >
2407               __virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len)))
2408                 vnet_hdr->hdr_len = __cpu_to_virtio16(vio_le(),
2409                          __virtio16_to_cpu(vio_le(), vnet_hdr->csum_start) +
2410                         __virtio16_to_cpu(vio_le(), vnet_hdr->csum_offset) + 2);
2411
2412         if (__virtio16_to_cpu(vio_le(), vnet_hdr->hdr_len) > len)
2413                 return -EINVAL;
2414
2415         return 0;
2416 }
2417
2418 static int packet_snd_vnet_parse(struct msghdr *msg, size_t *len,
2419                                  struct virtio_net_hdr *vnet_hdr)
2420 {
2421         if (*len < sizeof(*vnet_hdr))
2422                 return -EINVAL;
2423         *len -= sizeof(*vnet_hdr);
2424
2425         if (!copy_from_iter_full(vnet_hdr, sizeof(*vnet_hdr), &msg->msg_iter))
2426                 return -EFAULT;
2427
2428         return __packet_snd_vnet_parse(vnet_hdr, *len);
2429 }
2430
2431 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2432                 void *frame, struct net_device *dev, void *data, int tp_len,
2433                 __be16 proto, unsigned char *addr, int hlen, int copylen,
2434                 const struct sockcm_cookie *sockc)
2435 {
2436         union tpacket_uhdr ph;
2437         int to_write, offset, len, nr_frags, len_max;
2438         struct socket *sock = po->sk.sk_socket;
2439         struct page *page;
2440         int err;
2441
2442         ph.raw = frame;
2443
2444         skb->protocol = proto;
2445         skb->dev = dev;
2446         skb->priority = po->sk.sk_priority;
2447         skb->mark = po->sk.sk_mark;
2448         sock_tx_timestamp(&po->sk, sockc->tsflags, &skb_shinfo(skb)->tx_flags);
2449         skb_shinfo(skb)->destructor_arg = ph.raw;
2450
2451         skb_reserve(skb, hlen);
2452         skb_reset_network_header(skb);
2453
2454         to_write = tp_len;
2455
2456         if (sock->type == SOCK_DGRAM) {
2457                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2458                                 NULL, tp_len);
2459                 if (unlikely(err < 0))
2460                         return -EINVAL;
2461         } else if (copylen) {
2462                 int hdrlen = min_t(int, copylen, tp_len);
2463
2464                 skb_push(skb, dev->hard_header_len);
2465                 skb_put(skb, copylen - dev->hard_header_len);
2466                 err = skb_store_bits(skb, 0, data, hdrlen);
2467                 if (unlikely(err))
2468                         return err;
2469                 if (!dev_validate_header(dev, skb->data, hdrlen))
2470                         return -EINVAL;
2471                 if (!skb->protocol)
2472                         tpacket_set_protocol(dev, skb);
2473
2474                 data += hdrlen;
2475                 to_write -= hdrlen;
2476         }
2477
2478         offset = offset_in_page(data);
2479         len_max = PAGE_SIZE - offset;
2480         len = ((to_write > len_max) ? len_max : to_write);
2481
2482         skb->data_len = to_write;
2483         skb->len += to_write;
2484         skb->truesize += to_write;
2485         atomic_add(to_write, &po->sk.sk_wmem_alloc);
2486
2487         while (likely(to_write)) {
2488                 nr_frags = skb_shinfo(skb)->nr_frags;
2489
2490                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2491                         pr_err("Packet exceed the number of skb frags(%lu)\n",
2492                                MAX_SKB_FRAGS);
2493                         return -EFAULT;
2494                 }
2495
2496                 page = pgv_to_page(data);
2497                 data += len;
2498                 flush_dcache_page(page);
2499                 get_page(page);
2500                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2501                 to_write -= len;
2502                 offset = 0;
2503                 len_max = PAGE_SIZE;
2504                 len = ((to_write > len_max) ? len_max : to_write);
2505         }
2506
2507         skb_probe_transport_header(skb, 0);
2508
2509         return tp_len;
2510 }
2511
2512 static int tpacket_parse_header(struct packet_sock *po, void *frame,
2513                                 int size_max, void **data)
2514 {
2515         union tpacket_uhdr ph;
2516         int tp_len, off;
2517
2518         ph.raw = frame;
2519
2520         switch (po->tp_version) {
2521         case TPACKET_V3:
2522                 if (ph.h3->tp_next_offset != 0) {
2523                         pr_warn_once("variable sized slot not supported");
2524                         return -EINVAL;
2525                 }
2526                 tp_len = ph.h3->tp_len;
2527                 break;
2528         case TPACKET_V2:
2529                 tp_len = ph.h2->tp_len;
2530                 break;
2531         default:
2532                 tp_len = ph.h1->tp_len;
2533                 break;
2534         }
2535         if (unlikely(tp_len > size_max)) {
2536                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2537                 return -EMSGSIZE;
2538         }
2539
2540         if (unlikely(po->tp_tx_has_off)) {
2541                 int off_min, off_max;
2542
2543                 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2544                 off_max = po->tx_ring.frame_size - tp_len;
2545                 if (po->sk.sk_type == SOCK_DGRAM) {
2546                         switch (po->tp_version) {
2547                         case TPACKET_V3:
2548                                 off = ph.h3->tp_net;
2549                                 break;
2550                         case TPACKET_V2:
2551                                 off = ph.h2->tp_net;
2552                                 break;
2553                         default:
2554                                 off = ph.h1->tp_net;
2555                                 break;
2556                         }
2557                 } else {
2558                         switch (po->tp_version) {
2559                         case TPACKET_V3:
2560                                 off = ph.h3->tp_mac;
2561                                 break;
2562                         case TPACKET_V2:
2563                                 off = ph.h2->tp_mac;
2564                                 break;
2565                         default:
2566                                 off = ph.h1->tp_mac;
2567                                 break;
2568                         }
2569                 }
2570                 if (unlikely((off < off_min) || (off_max < off)))
2571                         return -EINVAL;
2572         } else {
2573                 off = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2574         }
2575
2576         *data = frame + off;
2577         return tp_len;
2578 }
2579
2580 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2581 {
2582         struct sk_buff *skb;
2583         struct net_device *dev;
2584         struct virtio_net_hdr *vnet_hdr = NULL;
2585         struct sockcm_cookie sockc;
2586         __be16 proto;
2587         int err, reserve = 0;
2588         void *ph;
2589         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2590         bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2591         int tp_len, size_max;
2592         unsigned char *addr;
2593         void *data;
2594         int len_sum = 0;
2595         int status = TP_STATUS_AVAILABLE;
2596         int hlen, tlen, copylen = 0;
2597
2598         mutex_lock(&po->pg_vec_lock);
2599
2600         if (likely(saddr == NULL)) {
2601                 dev     = packet_cached_dev_get(po);
2602                 proto   = po->num;
2603                 addr    = NULL;
2604         } else {
2605                 err = -EINVAL;
2606                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2607                         goto out;
2608                 if (msg->msg_namelen < (saddr->sll_halen
2609                                         + offsetof(struct sockaddr_ll,
2610                                                 sll_addr)))
2611                         goto out;
2612                 proto   = saddr->sll_protocol;
2613                 addr    = saddr->sll_addr;
2614                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2615         }
2616
2617         sockc.tsflags = po->sk.sk_tsflags;
2618         if (msg->msg_controllen) {
2619                 err = sock_cmsg_send(&po->sk, msg, &sockc);
2620                 if (unlikely(err))
2621                         goto out;
2622         }
2623
2624         err = -ENXIO;
2625         if (unlikely(dev == NULL))
2626                 goto out;
2627         err = -ENETDOWN;
2628         if (unlikely(!(dev->flags & IFF_UP)))
2629                 goto out_put;
2630
2631         if (po->sk.sk_socket->type == SOCK_RAW)
2632                 reserve = dev->hard_header_len;
2633         size_max = po->tx_ring.frame_size
2634                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2635
2636         if ((size_max > dev->mtu + reserve + VLAN_HLEN) && !po->has_vnet_hdr)
2637                 size_max = dev->mtu + reserve + VLAN_HLEN;
2638
2639         do {
2640                 ph = packet_current_frame(po, &po->tx_ring,
2641                                           TP_STATUS_SEND_REQUEST);
2642                 if (unlikely(ph == NULL)) {
2643                         if (need_wait && need_resched())
2644                                 schedule();
2645                         continue;
2646                 }
2647
2648                 skb = NULL;
2649                 tp_len = tpacket_parse_header(po, ph, size_max, &data);
2650                 if (tp_len < 0)
2651                         goto tpacket_error;
2652
2653                 status = TP_STATUS_SEND_REQUEST;
2654                 hlen = LL_RESERVED_SPACE(dev);
2655                 tlen = dev->needed_tailroom;
2656                 if (po->has_vnet_hdr) {
2657                         vnet_hdr = data;
2658                         data += sizeof(*vnet_hdr);
2659                         tp_len -= sizeof(*vnet_hdr);
2660                         if (tp_len < 0 ||
2661                             __packet_snd_vnet_parse(vnet_hdr, tp_len)) {
2662                                 tp_len = -EINVAL;
2663                                 goto tpacket_error;
2664                         }
2665                         copylen = __virtio16_to_cpu(vio_le(),
2666                                                     vnet_hdr->hdr_len);
2667                 }
2668                 copylen = max_t(int, copylen, dev->hard_header_len);
2669                 skb = sock_alloc_send_skb(&po->sk,
2670                                 hlen + tlen + sizeof(struct sockaddr_ll) +
2671                                 (copylen - dev->hard_header_len),
2672                                 !need_wait, &err);
2673
2674                 if (unlikely(skb == NULL)) {
2675                         /* we assume the socket was initially writeable ... */
2676                         if (likely(len_sum > 0))
2677                                 err = len_sum;
2678                         goto out_status;
2679                 }
2680                 tp_len = tpacket_fill_skb(po, skb, ph, dev, data, tp_len, proto,
2681                                           addr, hlen, copylen, &sockc);
2682                 if (likely(tp_len >= 0) &&
2683                     tp_len > dev->mtu + reserve &&
2684                     !po->has_vnet_hdr &&
2685                     !packet_extra_vlan_len_allowed(dev, skb))
2686                         tp_len = -EMSGSIZE;
2687
2688                 if (unlikely(tp_len < 0)) {
2689 tpacket_error:
2690                         if (po->tp_loss) {
2691                                 __packet_set_status(po, ph,
2692                                                 TP_STATUS_AVAILABLE);
2693                                 packet_increment_head(&po->tx_ring);
2694                                 kfree_skb(skb);
2695                                 continue;
2696                         } else {
2697                                 status = TP_STATUS_WRONG_FORMAT;
2698                                 err = tp_len;
2699                                 goto out_status;
2700                         }
2701                 }
2702
2703                 if (po->has_vnet_hdr && virtio_net_hdr_to_skb(skb, vnet_hdr,
2704                                                               vio_le())) {
2705                         tp_len = -EINVAL;
2706                         goto tpacket_error;
2707                 }
2708
2709                 packet_pick_tx_queue(dev, skb);
2710
2711                 skb->destructor = tpacket_destruct_skb;
2712                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2713                 packet_inc_pending(&po->tx_ring);
2714
2715                 status = TP_STATUS_SEND_REQUEST;
2716                 err = po->xmit(skb);
2717                 if (unlikely(err > 0)) {
2718                         err = net_xmit_errno(err);
2719                         if (err && __packet_get_status(po, ph) ==
2720                                    TP_STATUS_AVAILABLE) {
2721                                 /* skb was destructed already */
2722                                 skb = NULL;
2723                                 goto out_status;
2724                         }
2725                         /*
2726                          * skb was dropped but not destructed yet;
2727                          * let's treat it like congestion or err < 0
2728                          */
2729                         err = 0;
2730                 }
2731                 packet_increment_head(&po->tx_ring);
2732                 len_sum += tp_len;
2733         } while (likely((ph != NULL) ||
2734                 /* Note: packet_read_pending() might be slow if we have
2735                  * to call it as it's per_cpu variable, but in fast-path
2736                  * we already short-circuit the loop with the first
2737                  * condition, and luckily don't have to go that path
2738                  * anyway.
2739                  */
2740                  (need_wait && packet_read_pending(&po->tx_ring))));
2741
2742         err = len_sum;
2743         goto out_put;
2744
2745 out_status:
2746         __packet_set_status(po, ph, status);
2747         kfree_skb(skb);
2748 out_put:
2749         dev_put(dev);
2750 out:
2751         mutex_unlock(&po->pg_vec_lock);
2752         return err;
2753 }
2754
2755 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2756                                         size_t reserve, size_t len,
2757                                         size_t linear, int noblock,
2758                                         int *err)
2759 {
2760         struct sk_buff *skb;
2761
2762         /* Under a page?  Don't bother with paged skb. */
2763         if (prepad + len < PAGE_SIZE || !linear)
2764                 linear = len;
2765
2766         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2767                                    err, 0);
2768         if (!skb)
2769                 return NULL;
2770
2771         skb_reserve(skb, reserve);
2772         skb_put(skb, linear);
2773         skb->data_len = len - linear;
2774         skb->len += len - linear;
2775
2776         return skb;
2777 }
2778
2779 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2780 {
2781         struct sock *sk = sock->sk;
2782         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2783         struct sk_buff *skb;
2784         struct net_device *dev;
2785         __be16 proto;
2786         unsigned char *addr;
2787         int err, reserve = 0;
2788         struct sockcm_cookie sockc;
2789         struct virtio_net_hdr vnet_hdr = { 0 };
2790         int offset = 0;
2791         struct packet_sock *po = pkt_sk(sk);
2792         int hlen, tlen, linear;
2793         int extra_len = 0;
2794
2795         /*
2796          *      Get and verify the address.
2797          */
2798
2799         if (likely(saddr == NULL)) {
2800                 dev     = packet_cached_dev_get(po);
2801                 proto   = po->num;
2802                 addr    = NULL;
2803         } else {
2804                 err = -EINVAL;
2805                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2806                         goto out;
2807                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2808                         goto out;
2809                 proto   = saddr->sll_protocol;
2810                 addr    = saddr->sll_addr;
2811                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2812         }
2813
2814         err = -ENXIO;
2815         if (unlikely(dev == NULL))
2816                 goto out_unlock;
2817         err = -ENETDOWN;
2818         if (unlikely(!(dev->flags & IFF_UP)))
2819                 goto out_unlock;
2820
2821         sockc.tsflags = sk->sk_tsflags;
2822         sockc.mark = sk->sk_mark;
2823         if (msg->msg_controllen) {
2824                 err = sock_cmsg_send(sk, msg, &sockc);
2825                 if (unlikely(err))
2826                         goto out_unlock;
2827         }
2828
2829         if (sock->type == SOCK_RAW)
2830                 reserve = dev->hard_header_len;
2831         if (po->has_vnet_hdr) {
2832                 err = packet_snd_vnet_parse(msg, &len, &vnet_hdr);
2833                 if (err)
2834                         goto out_unlock;
2835         }
2836
2837         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2838                 if (!netif_supports_nofcs(dev)) {
2839                         err = -EPROTONOSUPPORT;
2840                         goto out_unlock;
2841                 }
2842                 extra_len = 4; /* We're doing our own CRC */
2843         }
2844
2845         err = -EMSGSIZE;
2846         if (!vnet_hdr.gso_type &&
2847             (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2848                 goto out_unlock;
2849
2850         err = -ENOBUFS;
2851         hlen = LL_RESERVED_SPACE(dev);
2852         tlen = dev->needed_tailroom;
2853         linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
2854         linear = max(linear, min_t(int, len, dev->hard_header_len));
2855         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
2856                                msg->msg_flags & MSG_DONTWAIT, &err);
2857         if (skb == NULL)
2858                 goto out_unlock;
2859
2860         skb_set_network_header(skb, reserve);
2861
2862         err = -EINVAL;
2863         if (sock->type == SOCK_DGRAM) {
2864                 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2865                 if (unlikely(offset < 0))
2866                         goto out_free;
2867         }
2868
2869         /* Returns -EFAULT on error */
2870         err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2871         if (err)
2872                 goto out_free;
2873
2874         if (sock->type == SOCK_RAW &&
2875             !dev_validate_header(dev, skb->data, len)) {
2876                 err = -EINVAL;
2877                 goto out_free;
2878         }
2879
2880         sock_tx_timestamp(sk, sockc.tsflags, &skb_shinfo(skb)->tx_flags);
2881
2882         if (!vnet_hdr.gso_type && (len > dev->mtu + reserve + extra_len) &&
2883             !packet_extra_vlan_len_allowed(dev, skb)) {
2884                 err = -EMSGSIZE;
2885                 goto out_free;
2886         }
2887
2888         skb->protocol = proto;
2889         skb->dev = dev;
2890         skb->priority = sk->sk_priority;
2891         skb->mark = sockc.mark;
2892
2893         packet_pick_tx_queue(dev, skb);
2894
2895         if (po->has_vnet_hdr) {
2896                 err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
2897                 if (err)
2898                         goto out_free;
2899                 len += sizeof(vnet_hdr);
2900         }
2901
2902         skb_probe_transport_header(skb, reserve);
2903
2904         if (unlikely(extra_len == 4))
2905                 skb->no_fcs = 1;
2906
2907         err = po->xmit(skb);
2908         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2909                 goto out_unlock;
2910
2911         dev_put(dev);
2912
2913         return len;
2914
2915 out_free:
2916         kfree_skb(skb);
2917 out_unlock:
2918         if (dev)
2919                 dev_put(dev);
2920 out:
2921         return err;
2922 }
2923
2924 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2925 {
2926         struct sock *sk = sock->sk;
2927         struct packet_sock *po = pkt_sk(sk);
2928
2929         if (po->tx_ring.pg_vec)
2930                 return tpacket_snd(po, msg);
2931         else
2932                 return packet_snd(sock, msg, len);
2933 }
2934
2935 /*
2936  *      Close a PACKET socket. This is fairly simple. We immediately go
2937  *      to 'closed' state and remove our protocol entry in the device list.
2938  */
2939
2940 static int packet_release(struct socket *sock)
2941 {
2942         struct sock *sk = sock->sk;
2943         struct packet_sock *po;
2944         struct packet_fanout *f;
2945         struct net *net;
2946         union tpacket_req_u req_u;
2947
2948         if (!sk)
2949                 return 0;
2950
2951         net = sock_net(sk);
2952         po = pkt_sk(sk);
2953
2954         mutex_lock(&net->packet.sklist_lock);
2955         sk_del_node_init_rcu(sk);
2956         mutex_unlock(&net->packet.sklist_lock);
2957
2958         preempt_disable();
2959         sock_prot_inuse_add(net, sk->sk_prot, -1);
2960         preempt_enable();
2961
2962         spin_lock(&po->bind_lock);
2963         unregister_prot_hook(sk, false);
2964         packet_cached_dev_reset(po);
2965
2966         if (po->prot_hook.dev) {
2967                 dev_put(po->prot_hook.dev);
2968                 po->prot_hook.dev = NULL;
2969         }
2970         spin_unlock(&po->bind_lock);
2971
2972         packet_flush_mclist(sk);
2973
2974         if (po->rx_ring.pg_vec) {
2975                 memset(&req_u, 0, sizeof(req_u));
2976                 packet_set_ring(sk, &req_u, 1, 0);
2977         }
2978
2979         if (po->tx_ring.pg_vec) {
2980                 memset(&req_u, 0, sizeof(req_u));
2981                 packet_set_ring(sk, &req_u, 1, 1);
2982         }
2983
2984         f = fanout_release(sk);
2985
2986         synchronize_net();
2987
2988         if (f) {
2989                 fanout_release_data(f);
2990                 kfree(f);
2991         }
2992         /*
2993          *      Now the socket is dead. No more input will appear.
2994          */
2995         sock_orphan(sk);
2996         sock->sk = NULL;
2997
2998         /* Purge queues */
2999
3000         skb_queue_purge(&sk->sk_receive_queue);
3001         packet_free_pending(po);
3002         sk_refcnt_debug_release(sk);
3003
3004         sock_put(sk);
3005         return 0;
3006 }
3007
3008 /*
3009  *      Attach a packet hook.
3010  */
3011
3012 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
3013                           __be16 proto)
3014 {
3015         struct packet_sock *po = pkt_sk(sk);
3016         struct net_device *dev_curr;
3017         __be16 proto_curr;
3018         bool need_rehook;
3019         struct net_device *dev = NULL;
3020         int ret = 0;
3021         bool unlisted = false;
3022
3023         if (po->fanout)
3024                 return -EINVAL;
3025
3026         lock_sock(sk);
3027         spin_lock(&po->bind_lock);
3028         rcu_read_lock();
3029
3030         if (name) {
3031                 dev = dev_get_by_name_rcu(sock_net(sk), name);
3032                 if (!dev) {
3033                         ret = -ENODEV;
3034                         goto out_unlock;
3035                 }
3036         } else if (ifindex) {
3037                 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
3038                 if (!dev) {
3039                         ret = -ENODEV;
3040                         goto out_unlock;
3041                 }
3042         }
3043
3044         if (dev)
3045                 dev_hold(dev);
3046
3047         proto_curr = po->prot_hook.type;
3048         dev_curr = po->prot_hook.dev;
3049
3050         need_rehook = proto_curr != proto || dev_curr != dev;
3051
3052         if (need_rehook) {
3053                 if (po->running) {
3054                         rcu_read_unlock();
3055                         __unregister_prot_hook(sk, true);
3056                         rcu_read_lock();
3057                         dev_curr = po->prot_hook.dev;
3058                         if (dev)
3059                                 unlisted = !dev_get_by_index_rcu(sock_net(sk),
3060                                                                  dev->ifindex);
3061                 }
3062
3063                 po->num = proto;
3064                 po->prot_hook.type = proto;
3065
3066                 if (unlikely(unlisted)) {
3067                         dev_put(dev);
3068                         po->prot_hook.dev = NULL;
3069                         po->ifindex = -1;
3070                         packet_cached_dev_reset(po);
3071                 } else {
3072                         po->prot_hook.dev = dev;
3073                         po->ifindex = dev ? dev->ifindex : 0;
3074                         packet_cached_dev_assign(po, dev);
3075                 }
3076         }
3077         if (dev_curr)
3078                 dev_put(dev_curr);
3079
3080         if (proto == 0 || !need_rehook)
3081                 goto out_unlock;
3082
3083         if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
3084                 register_prot_hook(sk);
3085         } else {
3086                 sk->sk_err = ENETDOWN;
3087                 if (!sock_flag(sk, SOCK_DEAD))
3088                         sk->sk_error_report(sk);
3089         }
3090
3091 out_unlock:
3092         rcu_read_unlock();
3093         spin_unlock(&po->bind_lock);
3094         release_sock(sk);
3095         return ret;
3096 }
3097
3098 /*
3099  *      Bind a packet socket to a device
3100  */
3101
3102 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
3103                             int addr_len)
3104 {
3105         struct sock *sk = sock->sk;
3106         char name[15];
3107
3108         /*
3109          *      Check legality
3110          */
3111
3112         if (addr_len != sizeof(struct sockaddr))
3113                 return -EINVAL;
3114         strlcpy(name, uaddr->sa_data, sizeof(name));
3115
3116         return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3117 }
3118
3119 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3120 {
3121         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3122         struct sock *sk = sock->sk;
3123
3124         /*
3125          *      Check legality
3126          */
3127
3128         if (addr_len < sizeof(struct sockaddr_ll))
3129                 return -EINVAL;
3130         if (sll->sll_family != AF_PACKET)
3131                 return -EINVAL;
3132
3133         return packet_do_bind(sk, NULL, sll->sll_ifindex,
3134                               sll->sll_protocol ? : pkt_sk(sk)->num);
3135 }
3136
3137 static struct proto packet_proto = {
3138         .name     = "PACKET",
3139         .owner    = THIS_MODULE,
3140         .obj_size = sizeof(struct packet_sock),
3141 };
3142
3143 /*
3144  *      Create a packet of type SOCK_PACKET.
3145  */
3146
3147 static int packet_create(struct net *net, struct socket *sock, int protocol,
3148                          int kern)
3149 {
3150         struct sock *sk;
3151         struct packet_sock *po;
3152         __be16 proto = (__force __be16)protocol; /* weird, but documented */
3153         int err;
3154
3155         if (!ns_capable(net->user_ns, CAP_NET_RAW))
3156                 return -EPERM;
3157         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3158             sock->type != SOCK_PACKET)
3159                 return -ESOCKTNOSUPPORT;
3160
3161         sock->state = SS_UNCONNECTED;
3162
3163         err = -ENOBUFS;
3164         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3165         if (sk == NULL)
3166                 goto out;
3167
3168         sock->ops = &packet_ops;
3169         if (sock->type == SOCK_PACKET)
3170                 sock->ops = &packet_ops_spkt;
3171
3172         sock_init_data(sock, sk);
3173
3174         po = pkt_sk(sk);
3175         sk->sk_family = PF_PACKET;
3176         po->num = proto;
3177         po->xmit = dev_queue_xmit;
3178
3179         err = packet_alloc_pending(po);
3180         if (err)
3181                 goto out2;
3182
3183         packet_cached_dev_reset(po);
3184
3185         sk->sk_destruct = packet_sock_destruct;
3186         sk_refcnt_debug_inc(sk);
3187
3188         /*
3189          *      Attach a protocol block
3190          */
3191
3192         spin_lock_init(&po->bind_lock);
3193         mutex_init(&po->pg_vec_lock);
3194         po->rollover = NULL;
3195         po->prot_hook.func = packet_rcv;
3196
3197         if (sock->type == SOCK_PACKET)
3198                 po->prot_hook.func = packet_rcv_spkt;
3199
3200         po->prot_hook.af_packet_priv = sk;
3201
3202         if (proto) {
3203                 po->prot_hook.type = proto;
3204                 register_prot_hook(sk);
3205         }
3206
3207         mutex_lock(&net->packet.sklist_lock);
3208         sk_add_node_rcu(sk, &net->packet.sklist);
3209         mutex_unlock(&net->packet.sklist_lock);
3210
3211         preempt_disable();
3212         sock_prot_inuse_add(net, &packet_proto, 1);
3213         preempt_enable();
3214
3215         return 0;
3216 out2:
3217         sk_free(sk);
3218 out:
3219         return err;
3220 }
3221
3222 /*
3223  *      Pull a packet from our receive queue and hand it to the user.
3224  *      If necessary we block.
3225  */
3226
3227 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3228                           int flags)
3229 {
3230         struct sock *sk = sock->sk;
3231         struct sk_buff *skb;
3232         int copied, err;
3233         int vnet_hdr_len = 0;
3234         unsigned int origlen = 0;
3235
3236         err = -EINVAL;
3237         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3238                 goto out;
3239
3240 #if 0
3241         /* What error should we return now? EUNATTACH? */
3242         if (pkt_sk(sk)->ifindex < 0)
3243                 return -ENODEV;
3244 #endif
3245
3246         if (flags & MSG_ERRQUEUE) {
3247                 err = sock_recv_errqueue(sk, msg, len,
3248                                          SOL_PACKET, PACKET_TX_TIMESTAMP);
3249                 goto out;
3250         }
3251
3252         /*
3253          *      Call the generic datagram receiver. This handles all sorts
3254          *      of horrible races and re-entrancy so we can forget about it
3255          *      in the protocol layers.
3256          *
3257          *      Now it will return ENETDOWN, if device have just gone down,
3258          *      but then it will block.
3259          */
3260
3261         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3262
3263         /*
3264          *      An error occurred so return it. Because skb_recv_datagram()
3265          *      handles the blocking we don't see and worry about blocking
3266          *      retries.
3267          */
3268
3269         if (skb == NULL)
3270                 goto out;
3271
3272         if (pkt_sk(sk)->pressure)
3273                 packet_rcv_has_room(pkt_sk(sk), NULL);
3274
3275         if (pkt_sk(sk)->has_vnet_hdr) {
3276                 err = packet_rcv_vnet(msg, skb, &len);
3277                 if (err)
3278                         goto out_free;
3279                 vnet_hdr_len = sizeof(struct virtio_net_hdr);
3280         }
3281
3282         /* You lose any data beyond the buffer you gave. If it worries
3283          * a user program they can ask the device for its MTU
3284          * anyway.
3285          */
3286         copied = skb->len;
3287         if (copied > len) {
3288                 copied = len;
3289                 msg->msg_flags |= MSG_TRUNC;
3290         }
3291
3292         err = skb_copy_datagram_msg(skb, 0, msg, copied);
3293         if (err)
3294                 goto out_free;
3295
3296         if (sock->type != SOCK_PACKET) {
3297                 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3298
3299                 /* Original length was stored in sockaddr_ll fields */
3300                 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3301                 sll->sll_family = AF_PACKET;
3302                 sll->sll_protocol = skb->protocol;
3303         }
3304
3305         sock_recv_ts_and_drops(msg, sk, skb);
3306
3307         if (msg->msg_name) {
3308                 /* If the address length field is there to be filled
3309                  * in, we fill it in now.
3310                  */
3311                 if (sock->type == SOCK_PACKET) {
3312                         __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3313                         msg->msg_namelen = sizeof(struct sockaddr_pkt);
3314                 } else {
3315                         struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3316
3317                         msg->msg_namelen = sll->sll_halen +
3318                                 offsetof(struct sockaddr_ll, sll_addr);
3319                 }
3320                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3321                        msg->msg_namelen);
3322         }
3323
3324         if (pkt_sk(sk)->auxdata) {
3325                 struct tpacket_auxdata aux;
3326
3327                 aux.tp_status = TP_STATUS_USER;
3328                 if (skb->ip_summed == CHECKSUM_PARTIAL)
3329                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3330                 else if (skb->pkt_type != PACKET_OUTGOING &&
3331                          (skb->ip_summed == CHECKSUM_COMPLETE ||
3332                           skb_csum_unnecessary(skb)))
3333                         aux.tp_status |= TP_STATUS_CSUM_VALID;
3334
3335                 aux.tp_len = origlen;
3336                 aux.tp_snaplen = skb->len;
3337                 aux.tp_mac = 0;
3338                 aux.tp_net = skb_network_offset(skb);
3339                 if (skb_vlan_tag_present(skb)) {
3340                         aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3341                         aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3342                         aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3343                 } else {
3344                         aux.tp_vlan_tci = 0;
3345                         aux.tp_vlan_tpid = 0;
3346                 }
3347                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3348         }
3349
3350         /*
3351          *      Free or return the buffer as appropriate. Again this
3352          *      hides all the races and re-entrancy issues from us.
3353          */
3354         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3355
3356 out_free:
3357         skb_free_datagram(sk, skb);
3358 out:
3359         return err;
3360 }
3361
3362 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3363                                int *uaddr_len, int peer)
3364 {
3365         struct net_device *dev;
3366         struct sock *sk = sock->sk;
3367
3368         if (peer)
3369                 return -EOPNOTSUPP;
3370
3371         uaddr->sa_family = AF_PACKET;
3372         memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3373         rcu_read_lock();
3374         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3375         if (dev)
3376                 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3377         rcu_read_unlock();
3378         *uaddr_len = sizeof(*uaddr);
3379
3380         return 0;
3381 }
3382
3383 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3384                           int *uaddr_len, int peer)
3385 {
3386         struct net_device *dev;
3387         struct sock *sk = sock->sk;
3388         struct packet_sock *po = pkt_sk(sk);
3389         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3390
3391         if (peer)
3392                 return -EOPNOTSUPP;
3393
3394         sll->sll_family = AF_PACKET;
3395         sll->sll_ifindex = po->ifindex;
3396         sll->sll_protocol = po->num;
3397         sll->sll_pkttype = 0;
3398         rcu_read_lock();
3399         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3400         if (dev) {
3401                 sll->sll_hatype = dev->type;
3402                 sll->sll_halen = dev->addr_len;
3403                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3404         } else {
3405                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
3406                 sll->sll_halen = 0;
3407         }
3408         rcu_read_unlock();
3409         *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3410
3411         return 0;
3412 }
3413
3414 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3415                          int what)
3416 {
3417         switch (i->type) {
3418         case PACKET_MR_MULTICAST:
3419                 if (i->alen != dev->addr_len)
3420                         return -EINVAL;
3421                 if (what > 0)
3422                         return dev_mc_add(dev, i->addr);
3423                 else
3424                         return dev_mc_del(dev, i->addr);
3425                 break;
3426         case PACKET_MR_PROMISC:
3427                 return dev_set_promiscuity(dev, what);
3428         case PACKET_MR_ALLMULTI:
3429                 return dev_set_allmulti(dev, what);
3430         case PACKET_MR_UNICAST:
3431                 if (i->alen != dev->addr_len)
3432                         return -EINVAL;
3433                 if (what > 0)
3434                         return dev_uc_add(dev, i->addr);
3435                 else
3436                         return dev_uc_del(dev, i->addr);
3437                 break;
3438         default:
3439                 break;
3440         }
3441         return 0;
3442 }
3443
3444 static void packet_dev_mclist_delete(struct net_device *dev,
3445                                      struct packet_mclist **mlp)
3446 {
3447         struct packet_mclist *ml;
3448
3449         while ((ml = *mlp) != NULL) {
3450                 if (ml->ifindex == dev->ifindex) {
3451                         packet_dev_mc(dev, ml, -1);
3452                         *mlp = ml->next;
3453                         kfree(ml);
3454                 } else
3455                         mlp = &ml->next;
3456         }
3457 }
3458
3459 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3460 {
3461         struct packet_sock *po = pkt_sk(sk);
3462         struct packet_mclist *ml, *i;
3463         struct net_device *dev;
3464         int err;
3465
3466         rtnl_lock();
3467
3468         err = -ENODEV;
3469         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3470         if (!dev)
3471                 goto done;
3472
3473         err = -EINVAL;
3474         if (mreq->mr_alen > dev->addr_len)
3475                 goto done;
3476
3477         err = -ENOBUFS;
3478         i = kmalloc(sizeof(*i), GFP_KERNEL);
3479         if (i == NULL)
3480                 goto done;
3481
3482         err = 0;
3483         for (ml = po->mclist; ml; ml = ml->next) {
3484                 if (ml->ifindex == mreq->mr_ifindex &&
3485                     ml->type == mreq->mr_type &&
3486                     ml->alen == mreq->mr_alen &&
3487                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3488                         ml->count++;
3489                         /* Free the new element ... */
3490                         kfree(i);
3491                         goto done;
3492                 }
3493         }
3494
3495         i->type = mreq->mr_type;
3496         i->ifindex = mreq->mr_ifindex;
3497         i->alen = mreq->mr_alen;
3498         memcpy(i->addr, mreq->mr_address, i->alen);
3499         memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
3500         i->count = 1;
3501         i->next = po->mclist;
3502         po->mclist = i;
3503         err = packet_dev_mc(dev, i, 1);
3504         if (err) {
3505                 po->mclist = i->next;
3506                 kfree(i);
3507         }
3508
3509 done:
3510         rtnl_unlock();
3511         return err;
3512 }
3513
3514 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3515 {
3516         struct packet_mclist *ml, **mlp;
3517
3518         rtnl_lock();
3519
3520         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3521                 if (ml->ifindex == mreq->mr_ifindex &&
3522                     ml->type == mreq->mr_type &&
3523                     ml->alen == mreq->mr_alen &&
3524                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3525                         if (--ml->count == 0) {
3526                                 struct net_device *dev;
3527                                 *mlp = ml->next;
3528                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3529                                 if (dev)
3530                                         packet_dev_mc(dev, ml, -1);
3531                                 kfree(ml);
3532                         }
3533                         break;
3534                 }
3535         }
3536         rtnl_unlock();
3537         return 0;
3538 }
3539
3540 static void packet_flush_mclist(struct sock *sk)
3541 {
3542         struct packet_sock *po = pkt_sk(sk);
3543         struct packet_mclist *ml;
3544
3545         if (!po->mclist)
3546                 return;
3547
3548         rtnl_lock();
3549         while ((ml = po->mclist) != NULL) {
3550                 struct net_device *dev;
3551
3552                 po->mclist = ml->next;
3553                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3554                 if (dev != NULL)
3555                         packet_dev_mc(dev, ml, -1);
3556                 kfree(ml);
3557         }
3558         rtnl_unlock();
3559 }
3560
3561 static int
3562 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3563 {
3564         struct sock *sk = sock->sk;
3565         struct packet_sock *po = pkt_sk(sk);
3566         int ret;
3567
3568         if (level != SOL_PACKET)
3569                 return -ENOPROTOOPT;
3570
3571         switch (optname) {
3572         case PACKET_ADD_MEMBERSHIP:
3573         case PACKET_DROP_MEMBERSHIP:
3574         {
3575                 struct packet_mreq_max mreq;
3576                 int len = optlen;
3577                 memset(&mreq, 0, sizeof(mreq));
3578                 if (len < sizeof(struct packet_mreq))
3579                         return -EINVAL;
3580                 if (len > sizeof(mreq))
3581                         len = sizeof(mreq);
3582                 if (copy_from_user(&mreq, optval, len))
3583                         return -EFAULT;
3584                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3585                         return -EINVAL;
3586                 if (optname == PACKET_ADD_MEMBERSHIP)
3587                         ret = packet_mc_add(sk, &mreq);
3588                 else
3589                         ret = packet_mc_drop(sk, &mreq);
3590                 return ret;
3591         }
3592
3593         case PACKET_RX_RING:
3594         case PACKET_TX_RING:
3595         {
3596                 union tpacket_req_u req_u;
3597                 int len;
3598
3599                 switch (po->tp_version) {
3600                 case TPACKET_V1:
3601                 case TPACKET_V2:
3602                         len = sizeof(req_u.req);
3603                         break;
3604                 case TPACKET_V3:
3605                 default:
3606                         len = sizeof(req_u.req3);
3607                         break;
3608                 }
3609                 if (optlen < len)
3610                         return -EINVAL;
3611                 if (copy_from_user(&req_u.req, optval, len))
3612                         return -EFAULT;
3613                 return packet_set_ring(sk, &req_u, 0,
3614                         optname == PACKET_TX_RING);
3615         }
3616         case PACKET_COPY_THRESH:
3617         {
3618                 int val;
3619
3620                 if (optlen != sizeof(val))
3621                         return -EINVAL;
3622                 if (copy_from_user(&val, optval, sizeof(val)))
3623                         return -EFAULT;
3624
3625                 pkt_sk(sk)->copy_thresh = val;
3626                 return 0;
3627         }
3628         case PACKET_VERSION:
3629         {
3630                 int val;
3631
3632                 if (optlen != sizeof(val))
3633                         return -EINVAL;
3634                 if (copy_from_user(&val, optval, sizeof(val)))
3635                         return -EFAULT;
3636                 switch (val) {
3637                 case TPACKET_V1:
3638                 case TPACKET_V2:
3639                 case TPACKET_V3:
3640                         break;
3641                 default:
3642                         return -EINVAL;
3643                 }
3644                 lock_sock(sk);
3645                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec) {
3646                         ret = -EBUSY;
3647                 } else {
3648                         po->tp_version = val;
3649                         ret = 0;
3650                 }
3651                 release_sock(sk);
3652                 return ret;
3653         }
3654         case PACKET_RESERVE:
3655         {
3656                 unsigned int val;
3657
3658                 if (optlen != sizeof(val))
3659                         return -EINVAL;
3660                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3661                         return -EBUSY;
3662                 if (copy_from_user(&val, optval, sizeof(val)))
3663                         return -EFAULT;
3664                 po->tp_reserve = val;
3665                 return 0;
3666         }
3667         case PACKET_LOSS:
3668         {
3669                 unsigned int val;
3670
3671                 if (optlen != sizeof(val))
3672                         return -EINVAL;
3673                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3674                         return -EBUSY;
3675                 if (copy_from_user(&val, optval, sizeof(val)))
3676                         return -EFAULT;
3677                 po->tp_loss = !!val;
3678                 return 0;
3679         }
3680         case PACKET_AUXDATA:
3681         {
3682                 int val;
3683
3684                 if (optlen < sizeof(val))
3685                         return -EINVAL;
3686                 if (copy_from_user(&val, optval, sizeof(val)))
3687                         return -EFAULT;
3688
3689                 po->auxdata = !!val;
3690                 return 0;
3691         }
3692         case PACKET_ORIGDEV:
3693         {
3694                 int val;
3695
3696                 if (optlen < sizeof(val))
3697                         return -EINVAL;
3698                 if (copy_from_user(&val, optval, sizeof(val)))
3699                         return -EFAULT;
3700
3701                 po->origdev = !!val;
3702                 return 0;
3703         }
3704         case PACKET_VNET_HDR:
3705         {
3706                 int val;
3707
3708                 if (sock->type != SOCK_RAW)
3709                         return -EINVAL;
3710                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3711                         return -EBUSY;
3712                 if (optlen < sizeof(val))
3713                         return -EINVAL;
3714                 if (copy_from_user(&val, optval, sizeof(val)))
3715                         return -EFAULT;
3716
3717                 po->has_vnet_hdr = !!val;
3718                 return 0;
3719         }
3720         case PACKET_TIMESTAMP:
3721         {
3722                 int val;
3723
3724                 if (optlen != sizeof(val))
3725                         return -EINVAL;
3726                 if (copy_from_user(&val, optval, sizeof(val)))
3727                         return -EFAULT;
3728
3729                 po->tp_tstamp = val;
3730                 return 0;
3731         }
3732         case PACKET_FANOUT:
3733         {
3734                 int val;
3735
3736                 if (optlen != sizeof(val))
3737                         return -EINVAL;
3738                 if (copy_from_user(&val, optval, sizeof(val)))
3739                         return -EFAULT;
3740
3741                 return fanout_add(sk, val & 0xffff, val >> 16);
3742         }
3743         case PACKET_FANOUT_DATA:
3744         {
3745                 if (!po->fanout)
3746                         return -EINVAL;
3747
3748                 return fanout_set_data(po, optval, optlen);
3749         }
3750         case PACKET_TX_HAS_OFF:
3751         {
3752                 unsigned int val;
3753
3754                 if (optlen != sizeof(val))
3755                         return -EINVAL;
3756                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3757                         return -EBUSY;
3758                 if (copy_from_user(&val, optval, sizeof(val)))
3759                         return -EFAULT;
3760                 po->tp_tx_has_off = !!val;
3761                 return 0;
3762         }
3763         case PACKET_QDISC_BYPASS:
3764         {
3765                 int val;
3766
3767                 if (optlen != sizeof(val))
3768                         return -EINVAL;
3769                 if (copy_from_user(&val, optval, sizeof(val)))
3770                         return -EFAULT;
3771
3772                 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3773                 return 0;
3774         }
3775         default:
3776                 return -ENOPROTOOPT;
3777         }
3778 }
3779
3780 static int packet_getsockopt(struct socket *sock, int level, int optname,
3781                              char __user *optval, int __user *optlen)
3782 {
3783         int len;
3784         int val, lv = sizeof(val);
3785         struct sock *sk = sock->sk;
3786         struct packet_sock *po = pkt_sk(sk);
3787         void *data = &val;
3788         union tpacket_stats_u st;
3789         struct tpacket_rollover_stats rstats;
3790
3791         if (level != SOL_PACKET)
3792                 return -ENOPROTOOPT;
3793
3794         if (get_user(len, optlen))
3795                 return -EFAULT;
3796
3797         if (len < 0)
3798                 return -EINVAL;
3799
3800         switch (optname) {
3801         case PACKET_STATISTICS:
3802                 spin_lock_bh(&sk->sk_receive_queue.lock);
3803                 memcpy(&st, &po->stats, sizeof(st));
3804                 memset(&po->stats, 0, sizeof(po->stats));
3805                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3806
3807                 if (po->tp_version == TPACKET_V3) {
3808                         lv = sizeof(struct tpacket_stats_v3);
3809                         st.stats3.tp_packets += st.stats3.tp_drops;
3810                         data = &st.stats3;
3811                 } else {
3812                         lv = sizeof(struct tpacket_stats);
3813                         st.stats1.tp_packets += st.stats1.tp_drops;
3814                         data = &st.stats1;
3815                 }
3816
3817                 break;
3818         case PACKET_AUXDATA:
3819                 val = po->auxdata;
3820                 break;
3821         case PACKET_ORIGDEV:
3822                 val = po->origdev;
3823                 break;
3824         case PACKET_VNET_HDR:
3825                 val = po->has_vnet_hdr;
3826                 break;
3827         case PACKET_VERSION:
3828                 val = po->tp_version;
3829                 break;
3830         case PACKET_HDRLEN:
3831                 if (len > sizeof(int))
3832                         len = sizeof(int);
3833                 if (copy_from_user(&val, optval, len))
3834                         return -EFAULT;
3835                 switch (val) {
3836                 case TPACKET_V1:
3837                         val = sizeof(struct tpacket_hdr);
3838                         break;
3839                 case TPACKET_V2:
3840                         val = sizeof(struct tpacket2_hdr);
3841                         break;
3842                 case TPACKET_V3:
3843                         val = sizeof(struct tpacket3_hdr);
3844                         break;
3845                 default:
3846                         return -EINVAL;
3847                 }
3848                 break;
3849         case PACKET_RESERVE:
3850                 val = po->tp_reserve;
3851                 break;
3852         case PACKET_LOSS:
3853                 val = po->tp_loss;
3854                 break;
3855         case PACKET_TIMESTAMP:
3856                 val = po->tp_tstamp;
3857                 break;
3858         case PACKET_FANOUT:
3859                 val = (po->fanout ?
3860                        ((u32)po->fanout->id |
3861                         ((u32)po->fanout->type << 16) |
3862                         ((u32)po->fanout->flags << 24)) :
3863                        0);
3864                 break;
3865         case PACKET_ROLLOVER_STATS:
3866                 if (!po->rollover)
3867                         return -EINVAL;
3868                 rstats.tp_all = atomic_long_read(&po->rollover->num);
3869                 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3870                 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3871                 data = &rstats;
3872                 lv = sizeof(rstats);
3873                 break;
3874         case PACKET_TX_HAS_OFF:
3875                 val = po->tp_tx_has_off;
3876                 break;
3877         case PACKET_QDISC_BYPASS:
3878                 val = packet_use_direct_xmit(po);
3879                 break;
3880         default:
3881                 return -ENOPROTOOPT;
3882         }
3883
3884         if (len > lv)
3885                 len = lv;
3886         if (put_user(len, optlen))
3887                 return -EFAULT;
3888         if (copy_to_user(optval, data, len))
3889                 return -EFAULT;
3890         return 0;
3891 }
3892
3893
3894 #ifdef CONFIG_COMPAT
3895 static int compat_packet_setsockopt(struct socket *sock, int level, int optname,
3896                                     char __user *optval, unsigned int optlen)
3897 {
3898         struct packet_sock *po = pkt_sk(sock->sk);
3899
3900         if (level != SOL_PACKET)
3901                 return -ENOPROTOOPT;
3902
3903         if (optname == PACKET_FANOUT_DATA &&
3904             po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) {
3905                 optval = (char __user *)get_compat_bpf_fprog(optval);
3906                 if (!optval)
3907                         return -EFAULT;
3908                 optlen = sizeof(struct sock_fprog);
3909         }
3910
3911         return packet_setsockopt(sock, level, optname, optval, optlen);
3912 }
3913 #endif
3914
3915 static int packet_notifier(struct notifier_block *this,
3916                            unsigned long msg, void *ptr)
3917 {
3918         struct sock *sk;
3919         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3920         struct net *net = dev_net(dev);
3921
3922         rcu_read_lock();
3923         sk_for_each_rcu(sk, &net->packet.sklist) {
3924                 struct packet_sock *po = pkt_sk(sk);
3925
3926                 switch (msg) {
3927                 case NETDEV_UNREGISTER:
3928                         if (po->mclist)
3929                                 packet_dev_mclist_delete(dev, &po->mclist);
3930                         /* fallthrough */
3931
3932                 case NETDEV_DOWN:
3933                         if (dev->ifindex == po->ifindex) {
3934                                 spin_lock(&po->bind_lock);
3935                                 if (po->running) {
3936                                         __unregister_prot_hook(sk, false);
3937                                         sk->sk_err = ENETDOWN;
3938                                         if (!sock_flag(sk, SOCK_DEAD))
3939                                                 sk->sk_error_report(sk);
3940                                 }
3941                                 if (msg == NETDEV_UNREGISTER) {
3942                                         packet_cached_dev_reset(po);
3943                                         po->ifindex = -1;
3944                                         if (po->prot_hook.dev)
3945                                                 dev_put(po->prot_hook.dev);
3946                                         po->prot_hook.dev = NULL;
3947                                 }
3948                                 spin_unlock(&po->bind_lock);
3949                         }
3950                         break;
3951                 case NETDEV_UP:
3952                         if (dev->ifindex == po->ifindex) {
3953                                 spin_lock(&po->bind_lock);
3954                                 if (po->num)
3955                                         register_prot_hook(sk);
3956                                 spin_unlock(&po->bind_lock);
3957                         }
3958                         break;
3959                 }
3960         }
3961         rcu_read_unlock();
3962         return NOTIFY_DONE;
3963 }
3964
3965
3966 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3967                         unsigned long arg)
3968 {
3969         struct sock *sk = sock->sk;
3970
3971         switch (cmd) {
3972         case SIOCOUTQ:
3973         {
3974                 int amount = sk_wmem_alloc_get(sk);
3975
3976                 return put_user(amount, (int __user *)arg);
3977         }
3978         case SIOCINQ:
3979         {
3980                 struct sk_buff *skb;
3981                 int amount = 0;
3982
3983                 spin_lock_bh(&sk->sk_receive_queue.lock);
3984                 skb = skb_peek(&sk->sk_receive_queue);
3985                 if (skb)
3986                         amount = skb->len;
3987                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3988                 return put_user(amount, (int __user *)arg);
3989         }
3990         case SIOCGSTAMP:
3991                 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3992         case SIOCGSTAMPNS:
3993                 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3994
3995 #ifdef CONFIG_INET
3996         case SIOCADDRT:
3997         case SIOCDELRT:
3998         case SIOCDARP:
3999         case SIOCGARP:
4000         case SIOCSARP:
4001         case SIOCGIFADDR:
4002         case SIOCSIFADDR:
4003         case SIOCGIFBRDADDR:
4004         case SIOCSIFBRDADDR:
4005         case SIOCGIFNETMASK:
4006         case SIOCSIFNETMASK:
4007         case SIOCGIFDSTADDR:
4008         case SIOCSIFDSTADDR:
4009         case SIOCSIFFLAGS:
4010                 return inet_dgram_ops.ioctl(sock, cmd, arg);
4011 #endif
4012
4013         default:
4014                 return -ENOIOCTLCMD;
4015         }
4016         return 0;
4017 }
4018
4019 static unsigned int packet_poll(struct file *file, struct socket *sock,
4020                                 poll_table *wait)
4021 {
4022         struct sock *sk = sock->sk;
4023         struct packet_sock *po = pkt_sk(sk);
4024         unsigned int mask = datagram_poll(file, sock, wait);
4025
4026         spin_lock_bh(&sk->sk_receive_queue.lock);
4027         if (po->rx_ring.pg_vec) {
4028                 if (!packet_previous_rx_frame(po, &po->rx_ring,
4029                         TP_STATUS_KERNEL))
4030                         mask |= POLLIN | POLLRDNORM;
4031         }
4032         if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
4033                 po->pressure = 0;
4034         spin_unlock_bh(&sk->sk_receive_queue.lock);
4035         spin_lock_bh(&sk->sk_write_queue.lock);
4036         if (po->tx_ring.pg_vec) {
4037                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
4038                         mask |= POLLOUT | POLLWRNORM;
4039         }
4040         spin_unlock_bh(&sk->sk_write_queue.lock);
4041         return mask;
4042 }
4043
4044
4045 /* Dirty? Well, I still did not learn better way to account
4046  * for user mmaps.
4047  */
4048
4049 static void packet_mm_open(struct vm_area_struct *vma)
4050 {
4051         struct file *file = vma->vm_file;
4052         struct socket *sock = file->private_data;
4053         struct sock *sk = sock->sk;
4054
4055         if (sk)
4056                 atomic_inc(&pkt_sk(sk)->mapped);
4057 }
4058
4059 static void packet_mm_close(struct vm_area_struct *vma)
4060 {
4061         struct file *file = vma->vm_file;
4062         struct socket *sock = file->private_data;
4063         struct sock *sk = sock->sk;
4064
4065         if (sk)
4066                 atomic_dec(&pkt_sk(sk)->mapped);
4067 }
4068
4069 static const struct vm_operations_struct packet_mmap_ops = {
4070         .open   =       packet_mm_open,
4071         .close  =       packet_mm_close,
4072 };
4073
4074 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
4075                         unsigned int len)
4076 {
4077         int i;
4078
4079         for (i = 0; i < len; i++) {
4080                 if (likely(pg_vec[i].buffer)) {
4081                         if (is_vmalloc_addr(pg_vec[i].buffer))
4082                                 vfree(pg_vec[i].buffer);
4083                         else
4084                                 free_pages((unsigned long)pg_vec[i].buffer,
4085                                            order);
4086                         pg_vec[i].buffer = NULL;
4087                 }
4088         }
4089         kfree(pg_vec);
4090 }
4091
4092 static char *alloc_one_pg_vec_page(unsigned long order)
4093 {
4094         char *buffer;
4095         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4096                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4097
4098         buffer = (char *) __get_free_pages(gfp_flags, order);
4099         if (buffer)
4100                 return buffer;
4101
4102         /* __get_free_pages failed, fall back to vmalloc */
4103         buffer = vzalloc((1 << order) * PAGE_SIZE);
4104         if (buffer)
4105                 return buffer;
4106
4107         /* vmalloc failed, lets dig into swap here */
4108         gfp_flags &= ~__GFP_NORETRY;
4109         buffer = (char *) __get_free_pages(gfp_flags, order);
4110         if (buffer)
4111                 return buffer;
4112
4113         /* complete and utter failure */
4114         return NULL;
4115 }
4116
4117 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4118 {
4119         unsigned int block_nr = req->tp_block_nr;
4120         struct pgv *pg_vec;
4121         int i;
4122
4123         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
4124         if (unlikely(!pg_vec))
4125                 goto out;
4126
4127         for (i = 0; i < block_nr; i++) {
4128                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4129                 if (unlikely(!pg_vec[i].buffer))
4130                         goto out_free_pgvec;
4131         }
4132
4133 out:
4134         return pg_vec;
4135
4136 out_free_pgvec:
4137         free_pg_vec(pg_vec, order, block_nr);
4138         pg_vec = NULL;
4139         goto out;
4140 }
4141
4142 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4143                 int closing, int tx_ring)
4144 {
4145         struct pgv *pg_vec = NULL;
4146         struct packet_sock *po = pkt_sk(sk);
4147         int was_running, order = 0;
4148         struct packet_ring_buffer *rb;
4149         struct sk_buff_head *rb_queue;
4150         __be16 num;
4151         int err = -EINVAL;
4152         /* Added to avoid minimal code churn */
4153         struct tpacket_req *req = &req_u->req;
4154
4155         lock_sock(sk);
4156
4157         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4158         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4159
4160         err = -EBUSY;
4161         if (!closing) {
4162                 if (atomic_read(&po->mapped))
4163                         goto out;
4164                 if (packet_read_pending(rb))
4165                         goto out;
4166         }
4167
4168         if (req->tp_block_nr) {
4169                 /* Sanity tests and some calculations */
4170                 err = -EBUSY;
4171                 if (unlikely(rb->pg_vec))
4172                         goto out;
4173
4174                 switch (po->tp_version) {
4175                 case TPACKET_V1:
4176                         po->tp_hdrlen = TPACKET_HDRLEN;
4177                         break;
4178                 case TPACKET_V2:
4179                         po->tp_hdrlen = TPACKET2_HDRLEN;
4180                         break;
4181                 case TPACKET_V3:
4182                         po->tp_hdrlen = TPACKET3_HDRLEN;
4183                         break;
4184                 }
4185
4186                 err = -EINVAL;
4187                 if (unlikely((int)req->tp_block_size <= 0))
4188                         goto out;
4189                 if (unlikely(!PAGE_ALIGNED(req->tp_block_size)))
4190                         goto out;
4191                 if (po->tp_version >= TPACKET_V3 &&
4192                     (int)(req->tp_block_size -
4193                           BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
4194                         goto out;
4195                 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
4196                                         po->tp_reserve))
4197                         goto out;
4198                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4199                         goto out;
4200
4201                 rb->frames_per_block = req->tp_block_size / req->tp_frame_size;
4202                 if (unlikely(rb->frames_per_block == 0))
4203                         goto out;
4204                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4205                                         req->tp_frame_nr))
4206                         goto out;
4207
4208                 err = -ENOMEM;
4209                 order = get_order(req->tp_block_size);
4210                 pg_vec = alloc_pg_vec(req, order);
4211                 if (unlikely(!pg_vec))
4212                         goto out;
4213                 switch (po->tp_version) {
4214                 case TPACKET_V3:
4215                         /* Block transmit is not supported yet */
4216                         if (!tx_ring) {
4217                                 init_prb_bdqc(po, rb, pg_vec, req_u);
4218                         } else {
4219                                 struct tpacket_req3 *req3 = &req_u->req3;
4220
4221                                 if (req3->tp_retire_blk_tov ||
4222                                     req3->tp_sizeof_priv ||
4223                                     req3->tp_feature_req_word) {
4224                                         err = -EINVAL;
4225                                         goto out;
4226                                 }
4227                         }
4228                         break;
4229                 default:
4230                         break;
4231                 }
4232         }
4233         /* Done */
4234         else {
4235                 err = -EINVAL;
4236                 if (unlikely(req->tp_frame_nr))
4237                         goto out;
4238         }
4239
4240
4241         /* Detach socket from network */
4242         spin_lock(&po->bind_lock);
4243         was_running = po->running;
4244         num = po->num;
4245         if (was_running) {
4246                 po->num = 0;
4247                 __unregister_prot_hook(sk, false);
4248         }
4249         spin_unlock(&po->bind_lock);
4250
4251         synchronize_net();
4252
4253         err = -EBUSY;
4254         mutex_lock(&po->pg_vec_lock);
4255         if (closing || atomic_read(&po->mapped) == 0) {
4256                 err = 0;
4257                 spin_lock_bh(&rb_queue->lock);
4258                 swap(rb->pg_vec, pg_vec);
4259                 rb->frame_max = (req->tp_frame_nr - 1);
4260                 rb->head = 0;
4261                 rb->frame_size = req->tp_frame_size;
4262                 spin_unlock_bh(&rb_queue->lock);
4263
4264                 swap(rb->pg_vec_order, order);
4265                 swap(rb->pg_vec_len, req->tp_block_nr);
4266
4267                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4268                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4269                                                 tpacket_rcv : packet_rcv;
4270                 skb_queue_purge(rb_queue);
4271                 if (atomic_read(&po->mapped))
4272                         pr_err("packet_mmap: vma is busy: %d\n",
4273                                atomic_read(&po->mapped));
4274         }
4275         mutex_unlock(&po->pg_vec_lock);
4276
4277         spin_lock(&po->bind_lock);
4278         if (was_running) {
4279                 po->num = num;
4280                 register_prot_hook(sk);
4281         }
4282         spin_unlock(&po->bind_lock);
4283         if (closing && (po->tp_version > TPACKET_V2)) {
4284                 /* Because we don't support block-based V3 on tx-ring */
4285                 if (!tx_ring)
4286                         prb_shutdown_retire_blk_timer(po, rb_queue);
4287         }
4288
4289         if (pg_vec)
4290                 free_pg_vec(pg_vec, order, req->tp_block_nr);
4291 out:
4292         release_sock(sk);
4293         return err;
4294 }
4295
4296 static int packet_mmap(struct file *file, struct socket *sock,
4297                 struct vm_area_struct *vma)
4298 {
4299         struct sock *sk = sock->sk;
4300         struct packet_sock *po = pkt_sk(sk);
4301         unsigned long size, expected_size;
4302         struct packet_ring_buffer *rb;
4303         unsigned long start;
4304         int err = -EINVAL;
4305         int i;
4306
4307         if (vma->vm_pgoff)
4308                 return -EINVAL;
4309
4310         mutex_lock(&po->pg_vec_lock);
4311
4312         expected_size = 0;
4313         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4314                 if (rb->pg_vec) {
4315                         expected_size += rb->pg_vec_len
4316                                                 * rb->pg_vec_pages
4317                                                 * PAGE_SIZE;
4318                 }
4319         }
4320
4321         if (expected_size == 0)
4322                 goto out;
4323
4324         size = vma->vm_end - vma->vm_start;
4325         if (size != expected_size)
4326                 goto out;
4327
4328         start = vma->vm_start;
4329         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4330                 if (rb->pg_vec == NULL)
4331                         continue;
4332
4333                 for (i = 0; i < rb->pg_vec_len; i++) {
4334                         struct page *page;
4335                         void *kaddr = rb->pg_vec[i].buffer;
4336                         int pg_num;
4337
4338                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4339                                 page = pgv_to_page(kaddr);
4340                                 err = vm_insert_page(vma, start, page);
4341                                 if (unlikely(err))
4342                                         goto out;
4343                                 start += PAGE_SIZE;
4344                                 kaddr += PAGE_SIZE;
4345                         }
4346                 }
4347         }
4348
4349         atomic_inc(&po->mapped);
4350         vma->vm_ops = &packet_mmap_ops;
4351         err = 0;
4352
4353 out:
4354         mutex_unlock(&po->pg_vec_lock);
4355         return err;
4356 }
4357
4358 static const struct proto_ops packet_ops_spkt = {
4359         .family =       PF_PACKET,
4360         .owner =        THIS_MODULE,
4361         .release =      packet_release,
4362         .bind =         packet_bind_spkt,
4363         .connect =      sock_no_connect,
4364         .socketpair =   sock_no_socketpair,
4365         .accept =       sock_no_accept,
4366         .getname =      packet_getname_spkt,
4367         .poll =         datagram_poll,
4368         .ioctl =        packet_ioctl,
4369         .listen =       sock_no_listen,
4370         .shutdown =     sock_no_shutdown,
4371         .setsockopt =   sock_no_setsockopt,
4372         .getsockopt =   sock_no_getsockopt,
4373         .sendmsg =      packet_sendmsg_spkt,
4374         .recvmsg =      packet_recvmsg,
4375         .mmap =         sock_no_mmap,
4376         .sendpage =     sock_no_sendpage,
4377 };
4378
4379 static const struct proto_ops packet_ops = {
4380         .family =       PF_PACKET,
4381         .owner =        THIS_MODULE,
4382         .release =      packet_release,
4383         .bind =         packet_bind,
4384         .connect =      sock_no_connect,
4385         .socketpair =   sock_no_socketpair,
4386         .accept =       sock_no_accept,
4387         .getname =      packet_getname,
4388         .poll =         packet_poll,
4389         .ioctl =        packet_ioctl,
4390         .listen =       sock_no_listen,
4391         .shutdown =     sock_no_shutdown,
4392         .setsockopt =   packet_setsockopt,
4393         .getsockopt =   packet_getsockopt,
4394 #ifdef CONFIG_COMPAT
4395         .compat_setsockopt = compat_packet_setsockopt,
4396 #endif
4397         .sendmsg =      packet_sendmsg,
4398         .recvmsg =      packet_recvmsg,
4399         .mmap =         packet_mmap,
4400         .sendpage =     sock_no_sendpage,
4401 };
4402
4403 static const struct net_proto_family packet_family_ops = {
4404         .family =       PF_PACKET,
4405         .create =       packet_create,
4406         .owner  =       THIS_MODULE,
4407 };
4408
4409 static struct notifier_block packet_netdev_notifier = {
4410         .notifier_call =        packet_notifier,
4411 };
4412
4413 #ifdef CONFIG_PROC_FS
4414
4415 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4416         __acquires(RCU)
4417 {
4418         struct net *net = seq_file_net(seq);
4419
4420         rcu_read_lock();
4421         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4422 }
4423
4424 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4425 {
4426         struct net *net = seq_file_net(seq);
4427         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4428 }
4429
4430 static void packet_seq_stop(struct seq_file *seq, void *v)
4431         __releases(RCU)
4432 {
4433         rcu_read_unlock();
4434 }
4435
4436 static int packet_seq_show(struct seq_file *seq, void *v)
4437 {
4438         if (v == SEQ_START_TOKEN)
4439                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
4440         else {
4441                 struct sock *s = sk_entry(v);
4442                 const struct packet_sock *po = pkt_sk(s);
4443
4444                 seq_printf(seq,
4445                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
4446                            s,
4447                            atomic_read(&s->sk_refcnt),
4448                            s->sk_type,
4449                            ntohs(po->num),
4450                            po->ifindex,
4451                            po->running,
4452                            atomic_read(&s->sk_rmem_alloc),
4453                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4454                            sock_i_ino(s));
4455         }
4456
4457         return 0;
4458 }
4459
4460 static const struct seq_operations packet_seq_ops = {
4461         .start  = packet_seq_start,
4462         .next   = packet_seq_next,
4463         .stop   = packet_seq_stop,
4464         .show   = packet_seq_show,
4465 };
4466
4467 static int packet_seq_open(struct inode *inode, struct file *file)
4468 {
4469         return seq_open_net(inode, file, &packet_seq_ops,
4470                             sizeof(struct seq_net_private));
4471 }
4472
4473 static const struct file_operations packet_seq_fops = {
4474         .owner          = THIS_MODULE,
4475         .open           = packet_seq_open,
4476         .read           = seq_read,
4477         .llseek         = seq_lseek,
4478         .release        = seq_release_net,
4479 };
4480
4481 #endif
4482
4483 static int __net_init packet_net_init(struct net *net)
4484 {
4485         mutex_init(&net->packet.sklist_lock);
4486         INIT_HLIST_HEAD(&net->packet.sklist);
4487
4488         if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4489                 return -ENOMEM;
4490
4491         return 0;
4492 }
4493
4494 static void __net_exit packet_net_exit(struct net *net)
4495 {
4496         remove_proc_entry("packet", net->proc_net);
4497 }
4498
4499 static struct pernet_operations packet_net_ops = {
4500         .init = packet_net_init,
4501         .exit = packet_net_exit,
4502 };
4503
4504
4505 static void __exit packet_exit(void)
4506 {
4507         unregister_netdevice_notifier(&packet_netdev_notifier);
4508         unregister_pernet_subsys(&packet_net_ops);
4509         sock_unregister(PF_PACKET);
4510         proto_unregister(&packet_proto);
4511 }
4512
4513 static int __init packet_init(void)
4514 {
4515         int rc = proto_register(&packet_proto, 0);
4516
4517         if (rc != 0)
4518                 goto out;
4519
4520         sock_register(&packet_family_ops);
4521         register_pernet_subsys(&packet_net_ops);
4522         register_netdevice_notifier(&packet_netdev_notifier);
4523 out:
4524         return rc;
4525 }
4526
4527 module_init(packet_init);
4528 module_exit(packet_exit);
4529 MODULE_LICENSE("GPL");
4530 MODULE_ALIAS_NETPROTO(PF_PACKET);