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 <asm/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
  97 #include "internal.h"
  98
  99 /*
 100    Assumptions:
 101    - if device has no dev->hard_header routine, it adds and removes ll header
 102      inside itself. In this case ll header is invisible outside of device,
 103      but higher levels still should reserve dev->hard_header_len.
 104      Some devices are enough clever to reallocate skb, when header
 105      will not fit to reserved space (tunnel), another ones are silly
 106      (PPP).
 107    - packet socket receives packets with pulled ll header,
 108      so that SOCK_RAW should push it back.
 109
 110 On receive:
 111 -----------
 112
 113 Incoming, dev->hard_header!=NULL
 114    mac_header -> ll header
 115    data       -> data
 116
 117 Outgoing, dev->hard_header!=NULL
 118    mac_header -> ll header
 119    data       -> ll header
 120
 121 Incoming, dev->hard_header==NULL
 122    mac_header -> UNKNOWN position. It is very likely, that it points to ll
 123                  header.  PPP makes it, that is wrong, because introduce
 124                  assymetry between rx and tx paths.
 125    data       -> data
 126
 127 Outgoing, dev->hard_header==NULL
 128    mac_header -> data. ll header is still not built!
 129    data       -> data
 130
 131 Resume
 132   If dev->hard_header==NULL we are unlikely to restore sensible ll header.
 133
 134
 135 On transmit:
 136 ------------
 137
 138 dev->hard_header != NULL
 139    mac_header -> ll header
 140    data       -> ll header
 141
 142 dev->hard_header == NULL (ll header is added by device, we cannot control it)
 143    mac_header -> data
 144    data       -> data
 145
 146    We should set nh.raw on output to correct posistion,
 147    packet classifier depends on it.
 148  */
 149
 150 /* Private packet socket structures. */
 151
 152 /* identical to struct packet_mreq except it has
 153  * a longer address field.
 154  */
 155 struct packet_mreq_max {
 156         int             mr_ifindex;
 157         unsigned short  mr_type;
 158         unsigned short  mr_alen;
 159         unsigned char   mr_address[MAX_ADDR_LEN];
 160 };
 161
 162 union tpacket_uhdr {
 163         struct tpacket_hdr  *h1;
 164         struct tpacket2_hdr *h2;
 165         struct tpacket3_hdr *h3;
 166         void *raw;
 167 };
 168
 169 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 170                 int closing, int tx_ring);
 171
 172 #define V3_ALIGNMENT    (8)
 173
 174 #define BLK_HDR_LEN     (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
 175
 176 #define BLK_PLUS_PRIV(sz_of_priv) \
 177         (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
 178
 179 #define PGV_FROM_VMALLOC 1
 180
 181 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
 182 #define BLOCK_NUM_PKTS(x)       ((x)->hdr.bh1.num_pkts)
 183 #define BLOCK_O2FP(x)           ((x)->hdr.bh1.offset_to_first_pkt)
 184 #define BLOCK_LEN(x)            ((x)->hdr.bh1.blk_len)
 185 #define BLOCK_SNUM(x)           ((x)->hdr.bh1.seq_num)
 186 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
 187 #define BLOCK_PRIV(x)           ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
 188
 189 struct packet_sock;
 190 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
 191 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
 192                        struct packet_type *pt, struct net_device *orig_dev);
 193
 194 static void *packet_previous_frame(struct packet_sock *po,
 195                 struct packet_ring_buffer *rb,
 196                 int status);
 197 static void packet_increment_head(struct packet_ring_buffer *buff);
 198 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
 199                         struct tpacket_block_desc *);
 200 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
 201                         struct packet_sock *);
 202 static void prb_retire_current_block(struct tpacket_kbdq_core *,
 203                 struct packet_sock *, unsigned int status);
 204 static int prb_queue_frozen(struct tpacket_kbdq_core *);
 205 static void prb_open_block(struct tpacket_kbdq_core *,
 206                 struct tpacket_block_desc *);
 207 static void prb_retire_rx_blk_timer_expired(unsigned long);
 208 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
 209 static void prb_init_blk_timer(struct packet_sock *,
 210                 struct tpacket_kbdq_core *,
 211                 void (*func) (unsigned long));
 212 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
 213 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
 214                 struct tpacket3_hdr *);
 215 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
 216                 struct tpacket3_hdr *);
 217 static void packet_flush_mclist(struct sock *sk);
 218
 219 struct packet_skb_cb {
 220         union {
 221                 struct sockaddr_pkt pkt;
 222                 union {
 223                         /* Trick: alias skb original length with
 224                          * ll.sll_family and ll.protocol in order
 225                          * to save room.
 226                          */
 227                         unsigned int origlen;
 228                         struct sockaddr_ll ll;
 229                 };
 230         } sa;
 231 };
 232
 233 #define vio_le() virtio_legacy_is_little_endian()
 234
 235 #define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
 236
 237 #define GET_PBDQC_FROM_RB(x)    ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
 238 #define GET_PBLOCK_DESC(x, bid) \
 239         ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
 240 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x)       \
 241         ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
 242 #define GET_NEXT_PRB_BLK_NUM(x) \
 243         (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
 244         ((x)->kactive_blk_num+1) : 0)
 245
 246 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
 247 static void __fanout_link(struct sock *sk, struct packet_sock *po);
 248
 249 static int packet_direct_xmit(struct sk_buff *skb)
 250 {
 251         struct net_device *dev = skb->dev;
 252         netdev_features_t features;
 253         struct netdev_queue *txq;
 254         int ret = NETDEV_TX_BUSY;
 255
 256         if (unlikely(!netif_running(dev) ||
 257                      !netif_carrier_ok(dev)))
 258                 goto drop;
 259
 260         features = netif_skb_features(skb);
 261         if (skb_needs_linearize(skb, features) &&
 262             __skb_linearize(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(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         default:
 413                 WARN(1, "TPACKET version not supported.\n");
 414                 BUG();
 415         }
 416
 417         smp_wmb();
 418 }
 419
 420 static int __packet_get_status(struct packet_sock *po, void *frame)
 421 {
 422         union tpacket_uhdr h;
 423
 424         smp_rmb();
 425
 426         h.raw = frame;
 427         switch (po->tp_version) {
 428         case TPACKET_V1:
 429                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 430                 return h.h1->tp_status;
 431         case TPACKET_V2:
 432                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 433                 return h.h2->tp_status;
 434         case TPACKET_V3:
 435         default:
 436                 WARN(1, "TPACKET version not supported.\n");
 437                 BUG();
 438                 return 0;
 439         }
 440 }
 441
 442 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
 443                                    unsigned int flags)
 444 {
 445         struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
 446
 447         if (shhwtstamps &&
 448             (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
 449             ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
 450                 return TP_STATUS_TS_RAW_HARDWARE;
 451
 452         if (ktime_to_timespec_cond(skb->tstamp, ts))
 453                 return TP_STATUS_TS_SOFTWARE;
 454
 455         return 0;
 456 }
 457
 458 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
 459                                     struct sk_buff *skb)
 460 {
 461         union tpacket_uhdr h;
 462         struct timespec ts;
 463         __u32 ts_status;
 464
 465         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
 466                 return 0;
 467
 468         h.raw = frame;
 469         switch (po->tp_version) {
 470         case TPACKET_V1:
 471                 h.h1->tp_sec = ts.tv_sec;
 472                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
 473                 break;
 474         case TPACKET_V2:
 475                 h.h2->tp_sec = ts.tv_sec;
 476                 h.h2->tp_nsec = ts.tv_nsec;
 477                 break;
 478         case TPACKET_V3:
 479         default:
 480                 WARN(1, "TPACKET version not supported.\n");
 481                 BUG();
 482         }
 483
 484         /* one flush is safe, as both fields always lie on the same cacheline */
 485         flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
 486         smp_wmb();
 487
 488         return ts_status;
 489 }
 490
 491 static void *packet_lookup_frame(struct packet_sock *po,
 492                 struct packet_ring_buffer *rb,
 493                 unsigned int position,
 494                 int status)
 495 {
 496         unsigned int pg_vec_pos, frame_offset;
 497         union tpacket_uhdr h;
 498
 499         pg_vec_pos = position / rb->frames_per_block;
 500         frame_offset = position % rb->frames_per_block;
 501
 502         h.raw = rb->pg_vec[pg_vec_pos].buffer +
 503                 (frame_offset * rb->frame_size);
 504
 505         if (status != __packet_get_status(po, h.raw))
 506                 return NULL;
 507
 508         return h.raw;
 509 }
 510
 511 static void *packet_current_frame(struct packet_sock *po,
 512                 struct packet_ring_buffer *rb,
 513                 int status)
 514 {
 515         return packet_lookup_frame(po, rb, rb->head, status);
 516 }
 517
 518 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 519 {
 520         del_timer_sync(&pkc->retire_blk_timer);
 521 }
 522
 523 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
 524                 struct sk_buff_head *rb_queue)
 525 {
 526         struct tpacket_kbdq_core *pkc;
 527
 528         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 529
 530         spin_lock_bh(&rb_queue->lock);
 531         pkc->delete_blk_timer = 1;
 532         spin_unlock_bh(&rb_queue->lock);
 533
 534         prb_del_retire_blk_timer(pkc);
 535 }
 536
 537 static void prb_init_blk_timer(struct packet_sock *po,
 538                 struct tpacket_kbdq_core *pkc,
 539                 void (*func) (unsigned long))
 540 {
 541         init_timer(&pkc->retire_blk_timer);
 542         pkc->retire_blk_timer.data = (long)po;
 543         pkc->retire_blk_timer.function = func;
 544         pkc->retire_blk_timer.expires = jiffies;
 545 }
 546
 547 static void prb_setup_retire_blk_timer(struct packet_sock *po)
 548 {
 549         struct tpacket_kbdq_core *pkc;
 550
 551         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 552         prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
 553 }
 554
 555 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
 556                                 int blk_size_in_bytes)
 557 {
 558         struct net_device *dev;
 559         unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
 560         struct ethtool_cmd ecmd;
 561         int err;
 562         u32 speed;
 563
 564         rtnl_lock();
 565         dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
 566         if (unlikely(!dev)) {
 567                 rtnl_unlock();
 568                 return DEFAULT_PRB_RETIRE_TOV;
 569         }
 570         err = __ethtool_get_settings(dev, &ecmd);
 571         speed = ethtool_cmd_speed(&ecmd);
 572         rtnl_unlock();
 573         if (!err) {
 574                 /*
 575                  * If the link speed is so slow you don't really
 576                  * need to worry about perf anyways
 577                  */
 578                 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
 579                         return DEFAULT_PRB_RETIRE_TOV;
 580                 } else {
 581                         msec = 1;
 582                         div = speed / 1000;
 583                 }
 584         }
 585
 586         mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
 587
 588         if (div)
 589                 mbits /= div;
 590
 591         tmo = mbits * msec;
 592
 593         if (div)
 594                 return tmo+1;
 595         return tmo;
 596 }
 597
 598 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
 599                         union tpacket_req_u *req_u)
 600 {
 601         p1->feature_req_word = req_u->req3.tp_feature_req_word;
 602 }
 603
 604 static void init_prb_bdqc(struct packet_sock *po,
 605                         struct packet_ring_buffer *rb,
 606                         struct pgv *pg_vec,
 607                         union tpacket_req_u *req_u)
 608 {
 609         struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
 610         struct tpacket_block_desc *pbd;
 611
 612         memset(p1, 0x0, sizeof(*p1));
 613
 614         p1->knxt_seq_num = 1;
 615         p1->pkbdq = pg_vec;
 616         pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
 617         p1->pkblk_start = pg_vec[0].buffer;
 618         p1->kblk_size = req_u->req3.tp_block_size;
 619         p1->knum_blocks = req_u->req3.tp_block_nr;
 620         p1->hdrlen = po->tp_hdrlen;
 621         p1->version = po->tp_version;
 622         p1->last_kactive_blk_num = 0;
 623         po->stats.stats3.tp_freeze_q_cnt = 0;
 624         if (req_u->req3.tp_retire_blk_tov)
 625                 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
 626         else
 627                 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
 628                                                 req_u->req3.tp_block_size);
 629         p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
 630         p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
 631
 632         p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
 633         prb_init_ft_ops(p1, req_u);
 634         prb_setup_retire_blk_timer(po);
 635         prb_open_block(p1, pbd);
 636 }
 637
 638 /*  Do NOT update the last_blk_num first.
 639  *  Assumes sk_buff_head lock is held.
 640  */
 641 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 642 {
 643         mod_timer(&pkc->retire_blk_timer,
 644                         jiffies + pkc->tov_in_jiffies);
 645         pkc->last_kactive_blk_num = pkc->kactive_blk_num;
 646 }
 647
 648 /*
 649  * Timer logic:
 650  * 1) We refresh the timer only when we open a block.
 651  *    By doing this we don't waste cycles refreshing the timer
 652  *        on packet-by-packet basis.
 653  *
 654  * With a 1MB block-size, on a 1Gbps line, it will take
 655  * i) ~8 ms to fill a block + ii) memcpy etc.
 656  * In this cut we are not accounting for the memcpy time.
 657  *
 658  * So, if the user sets the 'tmo' to 10ms then the timer
 659  * will never fire while the block is still getting filled
 660  * (which is what we want). However, the user could choose
 661  * to close a block early and that's fine.
 662  *
 663  * But when the timer does fire, we check whether or not to refresh it.
 664  * Since the tmo granularity is in msecs, it is not too expensive
 665  * to refresh the timer, lets say every '8' msecs.
 666  * Either the user can set the 'tmo' or we can derive it based on
 667  * a) line-speed and b) block-size.
 668  * prb_calc_retire_blk_tmo() calculates the tmo.
 669  *
 670  */
 671 static void prb_retire_rx_blk_timer_expired(unsigned long data)
 672 {
 673         struct packet_sock *po = (struct packet_sock *)data;
 674         struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 675         unsigned int frozen;
 676         struct tpacket_block_desc *pbd;
 677
 678         spin_lock(&po->sk.sk_receive_queue.lock);
 679
 680         frozen = prb_queue_frozen(pkc);
 681         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 682
 683         if (unlikely(pkc->delete_blk_timer))
 684                 goto out;
 685
 686         /* We only need to plug the race when the block is partially filled.
 687          * tpacket_rcv:
 688          *              lock(); increment BLOCK_NUM_PKTS; unlock()
 689          *              copy_bits() is in progress ...
 690          *              timer fires on other cpu:
 691          *              we can't retire the current block because copy_bits
 692          *              is in progress.
 693          *
 694          */
 695         if (BLOCK_NUM_PKTS(pbd)) {
 696                 while (atomic_read(&pkc->blk_fill_in_prog)) {
 697                         /* Waiting for skb_copy_bits to finish... */
 698                         cpu_relax();
 699                 }
 700         }
 701
 702         if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
 703                 if (!frozen) {
 704                         if (!BLOCK_NUM_PKTS(pbd)) {
 705                                 /* An empty block. Just refresh the timer. */
 706                                 goto refresh_timer;
 707                         }
 708                         prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
 709                         if (!prb_dispatch_next_block(pkc, po))
 710                                 goto refresh_timer;
 711                         else
 712                                 goto out;
 713                 } else {
 714                         /* Case 1. Queue was frozen because user-space was
 715                          *         lagging behind.
 716                          */
 717                         if (prb_curr_blk_in_use(pkc, pbd)) {
 718                                 /*
 719                                  * Ok, user-space is still behind.
 720                                  * So just refresh the timer.
 721                                  */
 722                                 goto refresh_timer;
 723                         } else {
 724                                /* Case 2. queue was frozen,user-space caught up,
 725                                 * now the link went idle && the timer fired.
 726                                 * We don't have a block to close.So we open this
 727                                 * block and restart the timer.
 728                                 * opening a block thaws the queue,restarts timer
 729                                 * Thawing/timer-refresh is a side effect.
 730                                 */
 731                                 prb_open_block(pkc, pbd);
 732                                 goto out;
 733                         }
 734                 }
 735         }
 736
 737 refresh_timer:
 738         _prb_refresh_rx_retire_blk_timer(pkc);
 739
 740 out:
 741         spin_unlock(&po->sk.sk_receive_queue.lock);
 742 }
 743
 744 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
 745                 struct tpacket_block_desc *pbd1, __u32 status)
 746 {
 747         /* Flush everything minus the block header */
 748
 749 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 750         u8 *start, *end;
 751
 752         start = (u8 *)pbd1;
 753
 754         /* Skip the block header(we know header WILL fit in 4K) */
 755         start += PAGE_SIZE;
 756
 757         end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
 758         for (; start < end; start += PAGE_SIZE)
 759                 flush_dcache_page(pgv_to_page(start));
 760
 761         smp_wmb();
 762 #endif
 763
 764         /* Now update the block status. */
 765
 766         BLOCK_STATUS(pbd1) = status;
 767
 768         /* Flush the block header */
 769
 770 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 771         start = (u8 *)pbd1;
 772         flush_dcache_page(pgv_to_page(start));
 773
 774         smp_wmb();
 775 #endif
 776 }
 777
 778 /*
 779  * Side effect:
 780  *
 781  * 1) flush the block
 782  * 2) Increment active_blk_num
 783  *
 784  * Note:We DONT refresh the timer on purpose.
 785  *      Because almost always the next block will be opened.
 786  */
 787 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
 788                 struct tpacket_block_desc *pbd1,
 789                 struct packet_sock *po, unsigned int stat)
 790 {
 791         __u32 status = TP_STATUS_USER | stat;
 792
 793         struct tpacket3_hdr *last_pkt;
 794         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 795         struct sock *sk = &po->sk;
 796
 797         if (po->stats.stats3.tp_drops)
 798                 status |= TP_STATUS_LOSING;
 799
 800         last_pkt = (struct tpacket3_hdr *)pkc1->prev;
 801         last_pkt->tp_next_offset = 0;
 802
 803         /* Get the ts of the last pkt */
 804         if (BLOCK_NUM_PKTS(pbd1)) {
 805                 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
 806                 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
 807         } else {
 808                 /* Ok, we tmo'd - so get the current time.
 809                  *
 810                  * It shouldn't really happen as we don't close empty
 811                  * blocks. See prb_retire_rx_blk_timer_expired().
 812                  */
 813                 struct timespec ts;
 814                 getnstimeofday(&ts);
 815                 h1->ts_last_pkt.ts_sec = ts.tv_sec;
 816                 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
 817         }
 818
 819         smp_wmb();
 820
 821         /* Flush the block */
 822         prb_flush_block(pkc1, pbd1, status);
 823
 824         sk->sk_data_ready(sk);
 825
 826         pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
 827 }
 828
 829 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
 830 {
 831         pkc->reset_pending_on_curr_blk = 0;
 832 }
 833
 834 /*
 835  * Side effect of opening a block:
 836  *
 837  * 1) prb_queue is thawed.
 838  * 2) retire_blk_timer is refreshed.
 839  *
 840  */
 841 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
 842         struct tpacket_block_desc *pbd1)
 843 {
 844         struct timespec ts;
 845         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 846
 847         smp_rmb();
 848
 849         /* We could have just memset this but we will lose the
 850          * flexibility of making the priv area sticky
 851          */
 852
 853         BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
 854         BLOCK_NUM_PKTS(pbd1) = 0;
 855         BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 856
 857         getnstimeofday(&ts);
 858
 859         h1->ts_first_pkt.ts_sec = ts.tv_sec;
 860         h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
 861
 862         pkc1->pkblk_start = (char *)pbd1;
 863         pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 864
 865         BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 866         BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
 867
 868         pbd1->version = pkc1->version;
 869         pkc1->prev = pkc1->nxt_offset;
 870         pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
 871
 872         prb_thaw_queue(pkc1);
 873         _prb_refresh_rx_retire_blk_timer(pkc1);
 874
 875         smp_wmb();
 876 }
 877
 878 /*
 879  * Queue freeze logic:
 880  * 1) Assume tp_block_nr = 8 blocks.
 881  * 2) At time 't0', user opens Rx ring.
 882  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
 883  * 4) user-space is either sleeping or processing block '0'.
 884  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
 885  *    it will close block-7,loop around and try to fill block '0'.
 886  *    call-flow:
 887  *    __packet_lookup_frame_in_block
 888  *      prb_retire_current_block()
 889  *      prb_dispatch_next_block()
 890  *        |->(BLOCK_STATUS == USER) evaluates to true
 891  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
 892  * 6) Now there are two cases:
 893  *    6.1) Link goes idle right after the queue is frozen.
 894  *         But remember, the last open_block() refreshed the timer.
 895  *         When this timer expires,it will refresh itself so that we can
 896  *         re-open block-0 in near future.
 897  *    6.2) Link is busy and keeps on receiving packets. This is a simple
 898  *         case and __packet_lookup_frame_in_block will check if block-0
 899  *         is free and can now be re-used.
 900  */
 901 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
 902                                   struct packet_sock *po)
 903 {
 904         pkc->reset_pending_on_curr_blk = 1;
 905         po->stats.stats3.tp_freeze_q_cnt++;
 906 }
 907
 908 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
 909
 910 /*
 911  * If the next block is free then we will dispatch it
 912  * and return a good offset.
 913  * Else, we will freeze the queue.
 914  * So, caller must check the return value.
 915  */
 916 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
 917                 struct packet_sock *po)
 918 {
 919         struct tpacket_block_desc *pbd;
 920
 921         smp_rmb();
 922
 923         /* 1. Get current block num */
 924         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 925
 926         /* 2. If this block is currently in_use then freeze the queue */
 927         if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
 928                 prb_freeze_queue(pkc, po);
 929                 return NULL;
 930         }
 931
 932         /*
 933          * 3.
 934          * open this block and return the offset where the first packet
 935          * needs to get stored.
 936          */
 937         prb_open_block(pkc, pbd);
 938         return (void *)pkc->nxt_offset;
 939 }
 940
 941 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
 942                 struct packet_sock *po, unsigned int status)
 943 {
 944         struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 945
 946         /* retire/close the current block */
 947         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
 948                 /*
 949                  * Plug the case where copy_bits() is in progress on
 950                  * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
 951                  * have space to copy the pkt in the current block and
 952                  * called prb_retire_current_block()
 953                  *
 954                  * We don't need to worry about the TMO case because
 955                  * the timer-handler already handled this case.
 956                  */
 957                 if (!(status & TP_STATUS_BLK_TMO)) {
 958                         while (atomic_read(&pkc->blk_fill_in_prog)) {
 959                                 /* Waiting for skb_copy_bits to finish... */
 960                                 cpu_relax();
 961                         }
 962                 }
 963                 prb_close_block(pkc, pbd, po, status);
 964                 return;
 965         }
 966 }
 967
 968 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
 969                                       struct tpacket_block_desc *pbd)
 970 {
 971         return TP_STATUS_USER & BLOCK_STATUS(pbd);
 972 }
 973
 974 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
 975 {
 976         return pkc->reset_pending_on_curr_blk;
 977 }
 978
 979 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
 980 {
 981         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
 982         atomic_dec(&pkc->blk_fill_in_prog);
 983 }
 984
 985 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
 986                         struct tpacket3_hdr *ppd)
 987 {
 988         ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
 989 }
 990
 991 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
 992                         struct tpacket3_hdr *ppd)
 993 {
 994         ppd->hv1.tp_rxhash = 0;
 995 }
 996
 997 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
 998                         struct tpacket3_hdr *ppd)
 999 {
1000         if (skb_vlan_tag_present(pkc->skb)) {
1001                 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1002                 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1003                 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1004         } else {
1005                 ppd->hv1.tp_vlan_tci = 0;
1006                 ppd->hv1.tp_vlan_tpid = 0;
1007                 ppd->tp_status = TP_STATUS_AVAILABLE;
1008         }
1009 }
1010
1011 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1012                         struct tpacket3_hdr *ppd)
1013 {
1014         ppd->hv1.tp_padding = 0;
1015         prb_fill_vlan_info(pkc, ppd);
1016
1017         if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1018                 prb_fill_rxhash(pkc, ppd);
1019         else
1020                 prb_clear_rxhash(pkc, ppd);
1021 }
1022
1023 static void prb_fill_curr_block(char *curr,
1024                                 struct tpacket_kbdq_core *pkc,
1025                                 struct tpacket_block_desc *pbd,
1026                                 unsigned int len)
1027 {
1028         struct tpacket3_hdr *ppd;
1029
1030         ppd  = (struct tpacket3_hdr *)curr;
1031         ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1032         pkc->prev = curr;
1033         pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1034         BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1035         BLOCK_NUM_PKTS(pbd) += 1;
1036         atomic_inc(&pkc->blk_fill_in_prog);
1037         prb_run_all_ft_ops(pkc, ppd);
1038 }
1039
1040 /* Assumes caller has the sk->rx_queue.lock */
1041 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1042                                             struct sk_buff *skb,
1043                                                 int status,
1044                                             unsigned int len
1045                                             )
1046 {
1047         struct tpacket_kbdq_core *pkc;
1048         struct tpacket_block_desc *pbd;
1049         char *curr, *end;
1050
1051         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1052         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1053
1054         /* Queue is frozen when user space is lagging behind */
1055         if (prb_queue_frozen(pkc)) {
1056                 /*
1057                  * Check if that last block which caused the queue to freeze,
1058                  * is still in_use by user-space.
1059                  */
1060                 if (prb_curr_blk_in_use(pkc, pbd)) {
1061                         /* Can't record this packet */
1062                         return NULL;
1063                 } else {
1064                         /*
1065                          * Ok, the block was released by user-space.
1066                          * Now let's open that block.
1067                          * opening a block also thaws the queue.
1068                          * Thawing is a side effect.
1069                          */
1070                         prb_open_block(pkc, pbd);
1071                 }
1072         }
1073
1074         smp_mb();
1075         curr = pkc->nxt_offset;
1076         pkc->skb = skb;
1077         end = (char *)pbd + pkc->kblk_size;
1078
1079         /* first try the current block */
1080         if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1081                 prb_fill_curr_block(curr, pkc, pbd, len);
1082                 return (void *)curr;
1083         }
1084
1085         /* Ok, close the current block */
1086         prb_retire_current_block(pkc, po, 0);
1087
1088         /* Now, try to dispatch the next block */
1089         curr = (char *)prb_dispatch_next_block(pkc, po);
1090         if (curr) {
1091                 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1092                 prb_fill_curr_block(curr, pkc, pbd, len);
1093                 return (void *)curr;
1094         }
1095
1096         /*
1097          * No free blocks are available.user_space hasn't caught up yet.
1098          * Queue was just frozen and now this packet will get dropped.
1099          */
1100         return NULL;
1101 }
1102
1103 static void *packet_current_rx_frame(struct packet_sock *po,
1104                                             struct sk_buff *skb,
1105                                             int status, unsigned int len)
1106 {
1107         char *curr = NULL;
1108         switch (po->tp_version) {
1109         case TPACKET_V1:
1110         case TPACKET_V2:
1111                 curr = packet_lookup_frame(po, &po->rx_ring,
1112                                         po->rx_ring.head, status);
1113                 return curr;
1114         case TPACKET_V3:
1115                 return __packet_lookup_frame_in_block(po, skb, status, len);
1116         default:
1117                 WARN(1, "TPACKET version not supported\n");
1118                 BUG();
1119                 return NULL;
1120         }
1121 }
1122
1123 static void *prb_lookup_block(struct packet_sock *po,
1124                                      struct packet_ring_buffer *rb,
1125                                      unsigned int idx,
1126                                      int status)
1127 {
1128         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1129         struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1130
1131         if (status != BLOCK_STATUS(pbd))
1132                 return NULL;
1133         return pbd;
1134 }
1135
1136 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1137 {
1138         unsigned int prev;
1139         if (rb->prb_bdqc.kactive_blk_num)
1140                 prev = rb->prb_bdqc.kactive_blk_num-1;
1141         else
1142                 prev = rb->prb_bdqc.knum_blocks-1;
1143         return prev;
1144 }
1145
1146 /* Assumes caller has held the rx_queue.lock */
1147 static void *__prb_previous_block(struct packet_sock *po,
1148                                          struct packet_ring_buffer *rb,
1149                                          int status)
1150 {
1151         unsigned int previous = prb_previous_blk_num(rb);
1152         return prb_lookup_block(po, rb, previous, status);
1153 }
1154
1155 static void *packet_previous_rx_frame(struct packet_sock *po,
1156                                              struct packet_ring_buffer *rb,
1157                                              int status)
1158 {
1159         if (po->tp_version <= TPACKET_V2)
1160                 return packet_previous_frame(po, rb, status);
1161
1162         return __prb_previous_block(po, rb, status);
1163 }
1164
1165 static void packet_increment_rx_head(struct packet_sock *po,
1166                                             struct packet_ring_buffer *rb)
1167 {
1168         switch (po->tp_version) {
1169         case TPACKET_V1:
1170         case TPACKET_V2:
1171                 return packet_increment_head(rb);
1172         case TPACKET_V3:
1173         default:
1174                 WARN(1, "TPACKET version not supported.\n");
1175                 BUG();
1176                 return;
1177         }
1178 }
1179
1180 static void *packet_previous_frame(struct packet_sock *po,
1181                 struct packet_ring_buffer *rb,
1182                 int status)
1183 {
1184         unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1185         return packet_lookup_frame(po, rb, previous, status);
1186 }
1187
1188 static void packet_increment_head(struct packet_ring_buffer *buff)
1189 {
1190         buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1191 }
1192
1193 static void packet_inc_pending(struct packet_ring_buffer *rb)
1194 {
1195         this_cpu_inc(*rb->pending_refcnt);
1196 }
1197
1198 static void packet_dec_pending(struct packet_ring_buffer *rb)
1199 {
1200         this_cpu_dec(*rb->pending_refcnt);
1201 }
1202
1203 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1204 {
1205         unsigned int refcnt = 0;
1206         int cpu;
1207
1208         /* We don't use pending refcount in rx_ring. */
1209         if (rb->pending_refcnt == NULL)
1210                 return 0;
1211
1212         for_each_possible_cpu(cpu)
1213                 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1214
1215         return refcnt;
1216 }
1217
1218 static int packet_alloc_pending(struct packet_sock *po)
1219 {
1220         po->rx_ring.pending_refcnt = NULL;
1221
1222         po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1223         if (unlikely(po->tx_ring.pending_refcnt == NULL))
1224                 return -ENOBUFS;
1225
1226         return 0;
1227 }
1228
1229 static void packet_free_pending(struct packet_sock *po)
1230 {
1231         free_percpu(po->tx_ring.pending_refcnt);
1232 }
1233
1234 #define ROOM_POW_OFF    2
1235 #define ROOM_NONE       0x0
1236 #define ROOM_LOW        0x1
1237 #define ROOM_NORMAL     0x2
1238
1239 static bool __tpacket_has_room(struct packet_sock *po, int pow_off)
1240 {
1241         int idx, len;
1242
1243         len = po->rx_ring.frame_max + 1;
1244         idx = po->rx_ring.head;
1245         if (pow_off)
1246                 idx += len >> pow_off;
1247         if (idx >= len)
1248                 idx -= len;
1249         return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1250 }
1251
1252 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off)
1253 {
1254         int idx, len;
1255
1256         len = po->rx_ring.prb_bdqc.knum_blocks;
1257         idx = po->rx_ring.prb_bdqc.kactive_blk_num;
1258         if (pow_off)
1259                 idx += len >> pow_off;
1260         if (idx >= len)
1261                 idx -= len;
1262         return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1263 }
1264
1265 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1266 {
1267         struct sock *sk = &po->sk;
1268         int ret = ROOM_NONE;
1269
1270         if (po->prot_hook.func != tpacket_rcv) {
1271                 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1272                                           - (skb ? skb->truesize : 0);
1273                 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF))
1274                         return ROOM_NORMAL;
1275                 else if (avail > 0)
1276                         return ROOM_LOW;
1277                 else
1278                         return ROOM_NONE;
1279         }
1280
1281         if (po->tp_version == TPACKET_V3) {
1282                 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1283                         ret = ROOM_NORMAL;
1284                 else if (__tpacket_v3_has_room(po, 0))
1285                         ret = ROOM_LOW;
1286         } else {
1287                 if (__tpacket_has_room(po, ROOM_POW_OFF))
1288                         ret = ROOM_NORMAL;
1289                 else if (__tpacket_has_room(po, 0))
1290                         ret = ROOM_LOW;
1291         }
1292
1293         return ret;
1294 }
1295
1296 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1297 {
1298         int ret;
1299         bool has_room;
1300
1301         spin_lock_bh(&po->sk.sk_receive_queue.lock);
1302         ret = __packet_rcv_has_room(po, skb);
1303         has_room = ret == ROOM_NORMAL;
1304         if (po->pressure == has_room)
1305                 po->pressure = !has_room;
1306         spin_unlock_bh(&po->sk.sk_receive_queue.lock);
1307
1308         return ret;
1309 }
1310
1311 static void packet_sock_destruct(struct sock *sk)
1312 {
1313         skb_queue_purge(&sk->sk_error_queue);
1314
1315         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1316         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1317
1318         if (!sock_flag(sk, SOCK_DEAD)) {
1319                 pr_err("Attempt to release alive packet socket: %p\n", sk);
1320                 return;
1321         }
1322
1323         sk_refcnt_debug_dec(sk);
1324 }
1325
1326 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1327 {
1328         u32 rxhash;
1329         int i, count = 0;
1330
1331         rxhash = skb_get_hash(skb);
1332         for (i = 0; i < ROLLOVER_HLEN; i++)
1333                 if (po->rollover->history[i] == rxhash)
1334                         count++;
1335
1336         po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1337         return count > (ROLLOVER_HLEN >> 1);
1338 }
1339
1340 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1341                                       struct sk_buff *skb,
1342                                       unsigned int num)
1343 {
1344         return reciprocal_scale(skb_get_hash(skb), num);
1345 }
1346
1347 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1348                                     struct sk_buff *skb,
1349                                     unsigned int num)
1350 {
1351         unsigned int val = atomic_inc_return(&f->rr_cur);
1352
1353         return val % num;
1354 }
1355
1356 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1357                                      struct sk_buff *skb,
1358                                      unsigned int num)
1359 {
1360         return smp_processor_id() % num;
1361 }
1362
1363 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1364                                      struct sk_buff *skb,
1365                                      unsigned int num)
1366 {
1367         return prandom_u32_max(num);
1368 }
1369
1370 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1371                                           struct sk_buff *skb,
1372                                           unsigned int idx, bool try_self,
1373                                           unsigned int num)
1374 {
1375         struct packet_sock *po, *po_next, *po_skip = NULL;
1376         unsigned int i, j, room = ROOM_NONE;
1377
1378         po = pkt_sk(f->arr[idx]);
1379
1380         if (try_self) {
1381                 room = packet_rcv_has_room(po, skb);
1382                 if (room == ROOM_NORMAL ||
1383                     (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1384                         return idx;
1385                 po_skip = po;
1386         }
1387
1388         i = j = min_t(int, po->rollover->sock, num - 1);
1389         do {
1390                 po_next = pkt_sk(f->arr[i]);
1391                 if (po_next != po_skip && !po_next->pressure &&
1392                     packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1393                         if (i != j)
1394                                 po->rollover->sock = i;
1395                         atomic_long_inc(&po->rollover->num);
1396                         if (room == ROOM_LOW)
1397                                 atomic_long_inc(&po->rollover->num_huge);
1398                         return i;
1399                 }
1400
1401                 if (++i == num)
1402                         i = 0;
1403         } while (i != j);
1404
1405         atomic_long_inc(&po->rollover->num_failed);
1406         return idx;
1407 }
1408
1409 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1410                                     struct sk_buff *skb,
1411                                     unsigned int num)
1412 {
1413         return skb_get_queue_mapping(skb) % num;
1414 }
1415
1416 static unsigned int fanout_demux_bpf(struct packet_fanout *f,
1417                                      struct sk_buff *skb,
1418                                      unsigned int num)
1419 {
1420         struct bpf_prog *prog;
1421         unsigned int ret = 0;
1422
1423         rcu_read_lock();
1424         prog = rcu_dereference(f->bpf_prog);
1425         if (prog)
1426                 ret = bpf_prog_run_clear_cb(prog, skb) % num;
1427         rcu_read_unlock();
1428
1429         return ret;
1430 }
1431
1432 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1433 {
1434         return f->flags & (flag >> 8);
1435 }
1436
1437 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1438                              struct packet_type *pt, struct net_device *orig_dev)
1439 {
1440         struct packet_fanout *f = pt->af_packet_priv;
1441         unsigned int num = READ_ONCE(f->num_members);
1442         struct net *net = read_pnet(&f->net);
1443         struct packet_sock *po;
1444         unsigned int idx;
1445
1446         if (!net_eq(dev_net(dev), net) || !num) {
1447                 kfree_skb(skb);
1448                 return 0;
1449         }
1450
1451         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1452                 skb = ip_check_defrag(net, skb, IP_DEFRAG_AF_PACKET);
1453                 if (!skb)
1454                         return 0;
1455         }
1456         switch (f->type) {
1457         case PACKET_FANOUT_HASH:
1458         default:
1459                 idx = fanout_demux_hash(f, skb, num);
1460                 break;
1461         case PACKET_FANOUT_LB:
1462                 idx = fanout_demux_lb(f, skb, num);
1463                 break;
1464         case PACKET_FANOUT_CPU:
1465                 idx = fanout_demux_cpu(f, skb, num);
1466                 break;
1467         case PACKET_FANOUT_RND:
1468                 idx = fanout_demux_rnd(f, skb, num);
1469                 break;
1470         case PACKET_FANOUT_QM:
1471                 idx = fanout_demux_qm(f, skb, num);
1472                 break;
1473         case PACKET_FANOUT_ROLLOVER:
1474                 idx = fanout_demux_rollover(f, skb, 0, false, num);
1475                 break;
1476         case PACKET_FANOUT_CBPF:
1477         case PACKET_FANOUT_EBPF:
1478                 idx = fanout_demux_bpf(f, skb, num);
1479                 break;
1480         }
1481
1482         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1483                 idx = fanout_demux_rollover(f, skb, idx, true, num);
1484
1485         po = pkt_sk(f->arr[idx]);
1486         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1487 }
1488
1489 DEFINE_MUTEX(fanout_mutex);
1490 EXPORT_SYMBOL_GPL(fanout_mutex);
1491 static LIST_HEAD(fanout_list);
1492
1493 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1494 {
1495         struct packet_fanout *f = po->fanout;
1496
1497         spin_lock(&f->lock);
1498         f->arr[f->num_members] = sk;
1499         smp_wmb();
1500         f->num_members++;
1501         spin_unlock(&f->lock);
1502 }
1503
1504 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1505 {
1506         struct packet_fanout *f = po->fanout;
1507         int i;
1508
1509         spin_lock(&f->lock);
1510         for (i = 0; i < f->num_members; i++) {
1511                 if (f->arr[i] == sk)
1512                         break;
1513         }
1514         BUG_ON(i >= f->num_members);
1515         f->arr[i] = f->arr[f->num_members - 1];
1516         f->num_members--;
1517         spin_unlock(&f->lock);
1518 }
1519
1520 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1521 {
1522         if (sk->sk_family != PF_PACKET)
1523                 return false;
1524
1525         return ptype->af_packet_priv == pkt_sk(sk)->fanout;
1526 }
1527
1528 static void fanout_init_data(struct packet_fanout *f)
1529 {
1530         switch (f->type) {
1531         case PACKET_FANOUT_LB:
1532                 atomic_set(&f->rr_cur, 0);
1533                 break;
1534         case PACKET_FANOUT_CBPF:
1535         case PACKET_FANOUT_EBPF:
1536                 RCU_INIT_POINTER(f->bpf_prog, NULL);
1537                 break;
1538         }
1539 }
1540
1541 static void __fanout_set_data_bpf(struct packet_fanout *f, struct bpf_prog *new)
1542 {
1543         struct bpf_prog *old;
1544
1545         spin_lock(&f->lock);
1546         old = rcu_dereference_protected(f->bpf_prog, lockdep_is_held(&f->lock));
1547         rcu_assign_pointer(f->bpf_prog, new);
1548         spin_unlock(&f->lock);
1549
1550         if (old) {
1551                 synchronize_net();
1552                 bpf_prog_destroy(old);
1553         }
1554 }
1555
1556 static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
1557                                 unsigned int len)
1558 {
1559         struct bpf_prog *new;
1560         struct sock_fprog fprog;
1561         int ret;
1562
1563         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1564                 return -EPERM;
1565         if (len != sizeof(fprog))
1566                 return -EINVAL;
1567         if (copy_from_user(&fprog, data, len))
1568                 return -EFAULT;
1569
1570         ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
1571         if (ret)
1572                 return ret;
1573
1574         __fanout_set_data_bpf(po->fanout, new);
1575         return 0;
1576 }
1577
1578 static int fanout_set_data_ebpf(struct packet_sock *po, char __user *data,
1579                                 unsigned int len)
1580 {
1581         struct bpf_prog *new;
1582         u32 fd;
1583
1584         if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
1585                 return -EPERM;
1586         if (len != sizeof(fd))
1587                 return -EINVAL;
1588         if (copy_from_user(&fd, data, len))
1589                 return -EFAULT;
1590
1591         new = bpf_prog_get(fd);
1592         if (IS_ERR(new))
1593                 return PTR_ERR(new);
1594         if (new->type != BPF_PROG_TYPE_SOCKET_FILTER) {
1595                 bpf_prog_put(new);
1596                 return -EINVAL;
1597         }
1598
1599         __fanout_set_data_bpf(po->fanout, new);
1600         return 0;
1601 }
1602
1603 static int fanout_set_data(struct packet_sock *po, char __user *data,
1604                            unsigned int len)
1605 {
1606         switch (po->fanout->type) {
1607         case PACKET_FANOUT_CBPF:
1608                 return fanout_set_data_cbpf(po, data, len);
1609         case PACKET_FANOUT_EBPF:
1610                 return fanout_set_data_ebpf(po, data, len);
1611         default:
1612                 return -EINVAL;
1613         };
1614 }
1615
1616 static void fanout_release_data(struct packet_fanout *f)
1617 {
1618         switch (f->type) {
1619         case PACKET_FANOUT_CBPF:
1620         case PACKET_FANOUT_EBPF:
1621                 __fanout_set_data_bpf(f, NULL);
1622         };
1623 }
1624
1625 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1626 {
1627         struct packet_sock *po = pkt_sk(sk);
1628         struct packet_fanout *f, *match;
1629         u8 type = type_flags & 0xff;
1630         u8 flags = type_flags >> 8;
1631         int err;
1632
1633         switch (type) {
1634         case PACKET_FANOUT_ROLLOVER:
1635                 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1636                         return -EINVAL;
1637         case PACKET_FANOUT_HASH:
1638         case PACKET_FANOUT_LB:
1639         case PACKET_FANOUT_CPU:
1640         case PACKET_FANOUT_RND:
1641         case PACKET_FANOUT_QM:
1642         case PACKET_FANOUT_CBPF:
1643         case PACKET_FANOUT_EBPF:
1644                 break;
1645         default:
1646                 return -EINVAL;
1647         }
1648
1649         if (!po->running)
1650                 return -EINVAL;
1651
1652         if (po->fanout)
1653                 return -EALREADY;
1654
1655         if (type == PACKET_FANOUT_ROLLOVER ||
1656             (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)) {
1657                 po->rollover = kzalloc(sizeof(*po->rollover), GFP_KERNEL);
1658                 if (!po->rollover)
1659                         return -ENOMEM;
1660                 atomic_long_set(&po->rollover->num, 0);
1661                 atomic_long_set(&po->rollover->num_huge, 0);
1662                 atomic_long_set(&po->rollover->num_failed, 0);
1663         }
1664
1665         mutex_lock(&fanout_mutex);
1666         match = NULL;
1667         list_for_each_entry(f, &fanout_list, list) {
1668                 if (f->id == id &&
1669                     read_pnet(&f->net) == sock_net(sk)) {
1670                         match = f;
1671                         break;
1672                 }
1673         }
1674         err = -EINVAL;
1675         if (match && match->flags != flags)
1676                 goto out;
1677         if (!match) {
1678                 err = -ENOMEM;
1679                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1680                 if (!match)
1681                         goto out;
1682                 write_pnet(&match->net, sock_net(sk));
1683                 match->id = id;
1684                 match->type = type;
1685                 match->flags = flags;
1686                 INIT_LIST_HEAD(&match->list);
1687                 spin_lock_init(&match->lock);
1688                 atomic_set(&match->sk_ref, 0);
1689                 fanout_init_data(match);
1690                 match->prot_hook.type = po->prot_hook.type;
1691                 match->prot_hook.dev = po->prot_hook.dev;
1692                 match->prot_hook.func = packet_rcv_fanout;
1693                 match->prot_hook.af_packet_priv = match;
1694                 match->prot_hook.id_match = match_fanout_group;
1695                 dev_add_pack(&match->prot_hook);
1696                 list_add(&match->list, &fanout_list);
1697         }
1698         err = -EINVAL;
1699         if (match->type == type &&
1700             match->prot_hook.type == po->prot_hook.type &&
1701             match->prot_hook.dev == po->prot_hook.dev) {
1702                 err = -ENOSPC;
1703                 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1704                         __dev_remove_pack(&po->prot_hook);
1705                         po->fanout = match;
1706                         atomic_inc(&match->sk_ref);
1707                         __fanout_link(sk, po);
1708                         err = 0;
1709                 }
1710         }
1711 out:
1712         mutex_unlock(&fanout_mutex);
1713         if (err) {
1714                 kfree(po->rollover);
1715                 po->rollover = NULL;
1716         }
1717         return err;
1718 }
1719
1720 static void fanout_release(struct sock *sk)
1721 {
1722         struct packet_sock *po = pkt_sk(sk);
1723         struct packet_fanout *f;
1724
1725         f = po->fanout;
1726         if (!f)
1727                 return;
1728
1729         mutex_lock(&fanout_mutex);
1730         po->fanout = NULL;
1731
1732         if (atomic_dec_and_test(&f->sk_ref)) {
1733                 list_del(&f->list);
1734                 dev_remove_pack(&f->prot_hook);
1735                 fanout_release_data(f);
1736                 kfree(f);
1737         }
1738         mutex_unlock(&fanout_mutex);
1739
1740         if (po->rollover)
1741                 kfree_rcu(po->rollover, rcu);
1742 }
1743
1744 static bool packet_extra_vlan_len_allowed(const struct net_device *dev,
1745                                           struct sk_buff *skb)
1746 {
1747         /* Earlier code assumed this would be a VLAN pkt, double-check
1748          * this now that we have the actual packet in hand. We can only
1749          * do this check on Ethernet devices.
1750          */
1751         if (unlikely(dev->type != ARPHRD_ETHER))
1752                 return false;
1753
1754         skb_reset_mac_header(skb);
1755         return likely(eth_hdr(skb)->h_proto == htons(ETH_P_8021Q));
1756 }
1757
1758 static const struct proto_ops packet_ops;
1759
1760 static const struct proto_ops packet_ops_spkt;
1761
1762 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1763                            struct packet_type *pt, struct net_device *orig_dev)
1764 {
1765         struct sock *sk;
1766         struct sockaddr_pkt *spkt;
1767
1768         /*
1769          *      When we registered the protocol we saved the socket in the data
1770          *      field for just this event.
1771          */
1772
1773         sk = pt->af_packet_priv;
1774
1775         /*
1776          *      Yank back the headers [hope the device set this
1777          *      right or kerboom...]
1778          *
1779          *      Incoming packets have ll header pulled,
1780          *      push it back.
1781          *
1782          *      For outgoing ones skb->data == skb_mac_header(skb)
1783          *      so that this procedure is noop.
1784          */
1785
1786         if (skb->pkt_type == PACKET_LOOPBACK)
1787                 goto out;
1788
1789         if (!net_eq(dev_net(dev), sock_net(sk)))
1790                 goto out;
1791
1792         skb = skb_share_check(skb, GFP_ATOMIC);
1793         if (skb == NULL)
1794                 goto oom;
1795
1796         /* drop any routing info */
1797         skb_dst_drop(skb);
1798
1799         /* drop conntrack reference */
1800         nf_reset(skb);
1801
1802         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1803
1804         skb_push(skb, skb->data - skb_mac_header(skb));
1805
1806         /*
1807          *      The SOCK_PACKET socket receives _all_ frames.
1808          */
1809
1810         spkt->spkt_family = dev->type;
1811         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1812         spkt->spkt_protocol = skb->protocol;
1813
1814         /*
1815          *      Charge the memory to the socket. This is done specifically
1816          *      to prevent sockets using all the memory up.
1817          */
1818
1819         if (sock_queue_rcv_skb(sk, skb) == 0)
1820                 return 0;
1821
1822 out:
1823         kfree_skb(skb);
1824 oom:
1825         return 0;
1826 }
1827
1828
1829 /*
1830  *      Output a raw packet to a device layer. This bypasses all the other
1831  *      protocol layers and you must therefore supply it with a complete frame
1832  */
1833
1834 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1835                                size_t len)
1836 {
1837         struct sock *sk = sock->sk;
1838         DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1839         struct sk_buff *skb = NULL;
1840         struct net_device *dev;
1841         __be16 proto = 0;
1842         int err;
1843         int extra_len = 0;
1844
1845         /*
1846          *      Get and verify the address.
1847          */
1848
1849         if (saddr) {
1850                 if (msg->msg_namelen < sizeof(struct sockaddr))
1851                         return -EINVAL;
1852                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1853                         proto = saddr->spkt_protocol;
1854         } else
1855                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1856
1857         /*
1858          *      Find the device first to size check it
1859          */
1860
1861         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1862 retry:
1863         rcu_read_lock();
1864         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1865         err = -ENODEV;
1866         if (dev == NULL)
1867                 goto out_unlock;
1868
1869         err = -ENETDOWN;
1870         if (!(dev->flags & IFF_UP))
1871                 goto out_unlock;
1872
1873         /*
1874          * You may not queue a frame bigger than the mtu. This is the lowest level
1875          * raw protocol and you must do your own fragmentation at this level.
1876          */
1877
1878         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1879                 if (!netif_supports_nofcs(dev)) {
1880                         err = -EPROTONOSUPPORT;
1881                         goto out_unlock;
1882                 }
1883                 extra_len = 4; /* We're doing our own CRC */
1884         }
1885
1886         err = -EMSGSIZE;
1887         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1888                 goto out_unlock;
1889
1890         if (!skb) {
1891                 size_t reserved = LL_RESERVED_SPACE(dev);
1892                 int tlen = dev->needed_tailroom;
1893                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1894
1895                 rcu_read_unlock();
1896                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1897                 if (skb == NULL)
1898                         return -ENOBUFS;
1899                 /* FIXME: Save some space for broken drivers that write a hard
1900                  * header at transmission time by themselves. PPP is the notable
1901                  * one here. This should really be fixed at the driver level.
1902                  */
1903                 skb_reserve(skb, reserved);
1904                 skb_reset_network_header(skb);
1905
1906                 /* Try to align data part correctly */
1907                 if (hhlen) {
1908                         skb->data -= hhlen;
1909                         skb->tail -= hhlen;
1910                         if (len < hhlen)
1911                                 skb_reset_network_header(skb);
1912                 }
1913                 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1914                 if (err)
1915                         goto out_free;
1916                 goto retry;
1917         }
1918
1919         if (len > (dev->mtu + dev->hard_header_len + extra_len) &&
1920             !packet_extra_vlan_len_allowed(dev, skb)) {
1921                 err = -EMSGSIZE;
1922                 goto out_unlock;
1923         }
1924
1925         skb->protocol = proto;
1926         skb->dev = dev;
1927         skb->priority = sk->sk_priority;
1928         skb->mark = sk->sk_mark;
1929
1930         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1931
1932         if (unlikely(extra_len == 4))
1933                 skb->no_fcs = 1;
1934
1935         skb_probe_transport_header(skb, 0);
1936
1937         dev_queue_xmit(skb);
1938         rcu_read_unlock();
1939         return len;
1940
1941 out_unlock:
1942         rcu_read_unlock();
1943 out_free:
1944         kfree_skb(skb);
1945         return err;
1946 }
1947
1948 static unsigned int run_filter(struct sk_buff *skb,
1949                                const struct sock *sk,
1950                                unsigned int res)
1951 {
1952         struct sk_filter *filter;
1953
1954         rcu_read_lock();
1955         filter = rcu_dereference(sk->sk_filter);
1956         if (filter != NULL)
1957                 res = bpf_prog_run_clear_cb(filter->prog, skb);
1958         rcu_read_unlock();
1959
1960         return res;
1961 }
1962
1963 /*
1964  * This function makes lazy skb cloning in hope that most of packets
1965  * are discarded by BPF.
1966  *
1967  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1968  * and skb->cb are mangled. It works because (and until) packets
1969  * falling here are owned by current CPU. Output packets are cloned
1970  * by dev_queue_xmit_nit(), input packets are processed by net_bh
1971  * sequencially, so that if we return skb to original state on exit,
1972  * we will not harm anyone.
1973  */
1974
1975 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1976                       struct packet_type *pt, struct net_device *orig_dev)
1977 {
1978         struct sock *sk;
1979         struct sockaddr_ll *sll;
1980         struct packet_sock *po;
1981         u8 *skb_head = skb->data;
1982         int skb_len = skb->len;
1983         unsigned int snaplen, res;
1984
1985         if (skb->pkt_type == PACKET_LOOPBACK)
1986                 goto drop;
1987
1988         sk = pt->af_packet_priv;
1989         po = pkt_sk(sk);
1990
1991         if (!net_eq(dev_net(dev), sock_net(sk)))
1992                 goto drop;
1993
1994         skb->dev = dev;
1995
1996         if (dev->header_ops) {
1997                 /* The device has an explicit notion of ll header,
1998                  * exported to higher levels.
1999                  *
2000                  * Otherwise, the device hides details of its frame
2001                  * structure, so that corresponding packet head is
2002                  * never delivered to user.
2003                  */
2004                 if (sk->sk_type != SOCK_DGRAM)
2005                         skb_push(skb, skb->data - skb_mac_header(skb));
2006                 else if (skb->pkt_type == PACKET_OUTGOING) {
2007                         /* Special case: outgoing packets have ll header at head */
2008                         skb_pull(skb, skb_network_offset(skb));
2009                 }
2010         }
2011
2012         snaplen = skb->len;
2013
2014         res = run_filter(skb, sk, snaplen);
2015         if (!res)
2016                 goto drop_n_restore;
2017         if (snaplen > res)
2018                 snaplen = res;
2019
2020         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
2021                 goto drop_n_acct;
2022
2023         if (skb_shared(skb)) {
2024                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
2025                 if (nskb == NULL)
2026                         goto drop_n_acct;
2027
2028                 if (skb_head != skb->data) {
2029                         skb->data = skb_head;
2030                         skb->len = skb_len;
2031                 }
2032                 consume_skb(skb);
2033                 skb = nskb;
2034         }
2035
2036         sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
2037
2038         sll = &PACKET_SKB_CB(skb)->sa.ll;
2039         sll->sll_hatype = dev->type;
2040         sll->sll_pkttype = skb->pkt_type;
2041         if (unlikely(po->origdev))
2042                 sll->sll_ifindex = orig_dev->ifindex;
2043         else
2044                 sll->sll_ifindex = dev->ifindex;
2045
2046         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2047
2048         /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
2049          * Use their space for storing the original skb length.
2050          */
2051         PACKET_SKB_CB(skb)->sa.origlen = skb->len;
2052
2053         if (pskb_trim(skb, snaplen))
2054                 goto drop_n_acct;
2055
2056         skb_set_owner_r(skb, sk);
2057         skb->dev = NULL;
2058         skb_dst_drop(skb);
2059
2060         /* drop conntrack reference */
2061         nf_reset(skb);
2062
2063         spin_lock(&sk->sk_receive_queue.lock);
2064         po->stats.stats1.tp_packets++;
2065         sock_skb_set_dropcount(sk, skb);
2066         __skb_queue_tail(&sk->sk_receive_queue, skb);
2067         spin_unlock(&sk->sk_receive_queue.lock);
2068         sk->sk_data_ready(sk);
2069         return 0;
2070
2071 drop_n_acct:
2072         spin_lock(&sk->sk_receive_queue.lock);
2073         po->stats.stats1.tp_drops++;
2074         atomic_inc(&sk->sk_drops);
2075         spin_unlock(&sk->sk_receive_queue.lock);
2076
2077 drop_n_restore:
2078         if (skb_head != skb->data && skb_shared(skb)) {
2079                 skb->data = skb_head;
2080                 skb->len = skb_len;
2081         }
2082 drop:
2083         consume_skb(skb);
2084         return 0;
2085 }
2086
2087 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
2088                        struct packet_type *pt, struct net_device *orig_dev)
2089 {
2090         struct sock *sk;
2091         struct packet_sock *po;
2092         struct sockaddr_ll *sll;
2093         union tpacket_uhdr h;
2094         u8 *skb_head = skb->data;
2095         int skb_len = skb->len;
2096         unsigned int snaplen, res;
2097         unsigned long status = TP_STATUS_USER;
2098         unsigned short macoff, netoff, hdrlen;
2099         struct sk_buff *copy_skb = NULL;
2100         struct timespec ts;
2101         __u32 ts_status;
2102
2103         /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
2104          * We may add members to them until current aligned size without forcing
2105          * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
2106          */
2107         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
2108         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
2109
2110         if (skb->pkt_type == PACKET_LOOPBACK)
2111                 goto drop;
2112
2113         sk = pt->af_packet_priv;
2114         po = pkt_sk(sk);
2115
2116         if (!net_eq(dev_net(dev), sock_net(sk)))
2117                 goto drop;
2118
2119         if (dev->header_ops) {
2120                 if (sk->sk_type != SOCK_DGRAM)
2121                         skb_push(skb, skb->data - skb_mac_header(skb));
2122                 else if (skb->pkt_type == PACKET_OUTGOING) {
2123                         /* Special case: outgoing packets have ll header at head */
2124                         skb_pull(skb, skb_network_offset(skb));
2125                 }
2126         }
2127
2128         snaplen = skb->len;
2129
2130         res = run_filter(skb, sk, snaplen);
2131         if (!res)
2132                 goto drop_n_restore;
2133
2134         if (skb->ip_summed == CHECKSUM_PARTIAL)
2135                 status |= TP_STATUS_CSUMNOTREADY;
2136         else if (skb->pkt_type != PACKET_OUTGOING &&
2137                  (skb->ip_summed == CHECKSUM_COMPLETE ||
2138                   skb_csum_unnecessary(skb)))
2139                 status |= TP_STATUS_CSUM_VALID;
2140
2141         if (snaplen > res)
2142                 snaplen = res;
2143
2144         if (sk->sk_type == SOCK_DGRAM) {
2145                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2146                                   po->tp_reserve;
2147         } else {
2148                 unsigned int maclen = skb_network_offset(skb);
2149                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2150                                        (maclen < 16 ? 16 : maclen)) +
2151                         po->tp_reserve;
2152                 macoff = netoff - maclen;
2153         }
2154         if (po->tp_version <= TPACKET_V2) {
2155                 if (macoff + snaplen > po->rx_ring.frame_size) {
2156                         if (po->copy_thresh &&
2157                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2158                                 if (skb_shared(skb)) {
2159                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
2160                                 } else {
2161                                         copy_skb = skb_get(skb);
2162                                         skb_head = skb->data;
2163                                 }
2164                                 if (copy_skb)
2165                                         skb_set_owner_r(copy_skb, sk);
2166                         }
2167                         snaplen = po->rx_ring.frame_size - macoff;
2168                         if ((int)snaplen < 0)
2169                                 snaplen = 0;
2170                 }
2171         } else if (unlikely(macoff + snaplen >
2172                             GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2173                 u32 nval;
2174
2175                 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2176                 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2177                             snaplen, nval, macoff);
2178                 snaplen = nval;
2179                 if (unlikely((int)snaplen < 0)) {
2180                         snaplen = 0;
2181                         macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2182                 }
2183         }
2184         spin_lock(&sk->sk_receive_queue.lock);
2185         h.raw = packet_current_rx_frame(po, skb,
2186                                         TP_STATUS_KERNEL, (macoff+snaplen));
2187         if (!h.raw)
2188                 goto ring_is_full;
2189         if (po->tp_version <= TPACKET_V2) {
2190                 packet_increment_rx_head(po, &po->rx_ring);
2191         /*
2192          * LOSING will be reported till you read the stats,
2193          * because it's COR - Clear On Read.
2194          * Anyways, moving it for V1/V2 only as V3 doesn't need this
2195          * at packet level.
2196          */
2197                 if (po->stats.stats1.tp_drops)
2198                         status |= TP_STATUS_LOSING;
2199         }
2200         po->stats.stats1.tp_packets++;
2201         if (copy_skb) {
2202                 status |= TP_STATUS_COPY;
2203                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2204         }
2205         spin_unlock(&sk->sk_receive_queue.lock);
2206
2207         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2208
2209         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2210                 getnstimeofday(&ts);
2211
2212         status |= ts_status;
2213
2214         switch (po->tp_version) {
2215         case TPACKET_V1:
2216                 h.h1->tp_len = skb->len;
2217                 h.h1->tp_snaplen = snaplen;
2218                 h.h1->tp_mac = macoff;
2219                 h.h1->tp_net = netoff;
2220                 h.h1->tp_sec = ts.tv_sec;
2221                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2222                 hdrlen = sizeof(*h.h1);
2223                 break;
2224         case TPACKET_V2:
2225                 h.h2->tp_len = skb->len;
2226                 h.h2->tp_snaplen = snaplen;
2227                 h.h2->tp_mac = macoff;
2228                 h.h2->tp_net = netoff;
2229                 h.h2->tp_sec = ts.tv_sec;
2230                 h.h2->tp_nsec = ts.tv_nsec;
2231                 if (skb_vlan_tag_present(skb)) {
2232                         h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2233                         h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2234                         status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2235                 } else {
2236                         h.h2->tp_vlan_tci = 0;
2237                         h.h2->tp_vlan_tpid = 0;
2238                 }
2239                 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2240                 hdrlen = sizeof(*h.h2);
2241                 break;
2242         case TPACKET_V3:
2243                 /* tp_nxt_offset,vlan are already populated above.
2244                  * So DONT clear those fields here
2245                  */
2246                 h.h3->tp_status |= status;
2247                 h.h3->tp_len = skb->len;
2248                 h.h3->tp_snaplen = snaplen;
2249                 h.h3->tp_mac = macoff;
2250                 h.h3->tp_net = netoff;
2251                 h.h3->tp_sec  = ts.tv_sec;
2252                 h.h3->tp_nsec = ts.tv_nsec;
2253                 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2254                 hdrlen = sizeof(*h.h3);
2255                 break;
2256         default:
2257                 BUG();
2258         }
2259
2260         sll = h.raw + TPACKET_ALIGN(hdrlen);
2261         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2262         sll->sll_family = AF_PACKET;
2263         sll->sll_hatype = dev->type;
2264         sll->sll_protocol = skb->protocol;
2265         sll->sll_pkttype = skb->pkt_type;
2266         if (unlikely(po->origdev))
2267                 sll->sll_ifindex = orig_dev->ifindex;
2268         else
2269                 sll->sll_ifindex = dev->ifindex;
2270
2271         smp_mb();
2272
2273 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2274         if (po->tp_version <= TPACKET_V2) {
2275                 u8 *start, *end;
2276
2277                 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2278                                         macoff + snaplen);
2279
2280                 for (start = h.raw; start < end; start += PAGE_SIZE)
2281                         flush_dcache_page(pgv_to_page(start));
2282         }
2283         smp_wmb();
2284 #endif
2285
2286         if (po->tp_version <= TPACKET_V2) {
2287                 __packet_set_status(po, h.raw, status);
2288                 sk->sk_data_ready(sk);
2289         } else {
2290                 prb_clear_blk_fill_status(&po->rx_ring);
2291         }
2292
2293 drop_n_restore:
2294         if (skb_head != skb->data && skb_shared(skb)) {
2295                 skb->data = skb_head;
2296                 skb->len = skb_len;
2297         }
2298 drop:
2299         kfree_skb(skb);
2300         return 0;
2301
2302 ring_is_full:
2303         po->stats.stats1.tp_drops++;
2304         spin_unlock(&sk->sk_receive_queue.lock);
2305
2306         sk->sk_data_ready(sk);
2307         kfree_skb(copy_skb);
2308         goto drop_n_restore;
2309 }
2310
2311 static void tpacket_destruct_skb(struct sk_buff *skb)
2312 {
2313         struct packet_sock *po = pkt_sk(skb->sk);
2314
2315         if (likely(po->tx_ring.pg_vec)) {
2316                 void *ph;
2317                 __u32 ts;
2318
2319                 ph = skb_shinfo(skb)->destructor_arg;
2320                 packet_dec_pending(&po->tx_ring);
2321
2322                 ts = __packet_set_timestamp(po, ph, skb);
2323                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2324         }
2325
2326         sock_wfree(skb);
2327 }
2328
2329 static bool ll_header_truncated(const struct net_device *dev, int len)
2330 {
2331         /* net device doesn't like empty head */
2332         if (unlikely(len <= dev->hard_header_len)) {
2333                 net_warn_ratelimited("%s: packet size is too short (%d <= %d)\n",
2334                                      current->comm, len, dev->hard_header_len);
2335                 return true;
2336         }
2337
2338         return false;
2339 }
2340
2341 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2342                 void *frame, struct net_device *dev, int size_max,
2343                 __be16 proto, unsigned char *addr, int hlen)
2344 {
2345         union tpacket_uhdr ph;
2346         int to_write, offset, len, tp_len, nr_frags, len_max;
2347         struct socket *sock = po->sk.sk_socket;
2348         struct page *page;
2349         void *data;
2350         int err;
2351
2352         ph.raw = frame;
2353
2354         skb->protocol = proto;
2355         skb->dev = dev;
2356         skb->priority = po->sk.sk_priority;
2357         skb->mark = po->sk.sk_mark;
2358         sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
2359         skb_shinfo(skb)->destructor_arg = ph.raw;
2360
2361         switch (po->tp_version) {
2362         case TPACKET_V2:
2363                 tp_len = ph.h2->tp_len;
2364                 break;
2365         default:
2366                 tp_len = ph.h1->tp_len;
2367                 break;
2368         }
2369         if (unlikely(tp_len > size_max)) {
2370                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2371                 return -EMSGSIZE;
2372         }
2373
2374         skb_reserve(skb, hlen);
2375         skb_reset_network_header(skb);
2376
2377         if (unlikely(po->tp_tx_has_off)) {
2378                 int off_min, off_max, off;
2379                 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2380                 off_max = po->tx_ring.frame_size - tp_len;
2381                 if (sock->type == SOCK_DGRAM) {
2382                         switch (po->tp_version) {
2383                         case TPACKET_V2:
2384                                 off = ph.h2->tp_net;
2385                                 break;
2386                         default:
2387                                 off = ph.h1->tp_net;
2388                                 break;
2389                         }
2390                 } else {
2391                         switch (po->tp_version) {
2392                         case TPACKET_V2:
2393                                 off = ph.h2->tp_mac;
2394                                 break;
2395                         default:
2396                                 off = ph.h1->tp_mac;
2397                                 break;
2398                         }
2399                 }
2400                 if (unlikely((off < off_min) || (off_max < off)))
2401                         return -EINVAL;
2402                 data = ph.raw + off;
2403         } else {
2404                 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2405         }
2406         to_write = tp_len;
2407
2408         if (sock->type == SOCK_DGRAM) {
2409                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2410                                 NULL, tp_len);
2411                 if (unlikely(err < 0))
2412                         return -EINVAL;
2413         } else if (dev->hard_header_len) {
2414                 if (ll_header_truncated(dev, tp_len))
2415                         return -EINVAL;
2416
2417                 skb_push(skb, dev->hard_header_len);
2418                 err = skb_store_bits(skb, 0, data,
2419                                 dev->hard_header_len);
2420                 if (unlikely(err))
2421                         return err;
2422
2423                 data += dev->hard_header_len;
2424                 to_write -= dev->hard_header_len;
2425         }
2426
2427         offset = offset_in_page(data);
2428         len_max = PAGE_SIZE - offset;
2429         len = ((to_write > len_max) ? len_max : to_write);
2430
2431         skb->data_len = to_write;
2432         skb->len += to_write;
2433         skb->truesize += to_write;
2434         atomic_add(to_write, &po->sk.sk_wmem_alloc);
2435
2436         while (likely(to_write)) {
2437                 nr_frags = skb_shinfo(skb)->nr_frags;
2438
2439                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2440                         pr_err("Packet exceed the number of skb frags(%lu)\n",
2441                                MAX_SKB_FRAGS);
2442                         return -EFAULT;
2443                 }
2444
2445                 page = pgv_to_page(data);
2446                 data += len;
2447                 flush_dcache_page(page);
2448                 get_page(page);
2449                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2450                 to_write -= len;
2451                 offset = 0;
2452                 len_max = PAGE_SIZE;
2453                 len = ((to_write > len_max) ? len_max : to_write);
2454         }
2455
2456         skb_probe_transport_header(skb, 0);
2457
2458         return tp_len;
2459 }
2460
2461 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2462 {
2463         struct sk_buff *skb;
2464         struct net_device *dev;
2465         __be16 proto;
2466         int err, reserve = 0;
2467         void *ph;
2468         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2469         bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2470         int tp_len, size_max;
2471         unsigned char *addr;
2472         int len_sum = 0;
2473         int status = TP_STATUS_AVAILABLE;
2474         int hlen, tlen;
2475
2476         mutex_lock(&po->pg_vec_lock);
2477
2478         if (likely(saddr == NULL)) {
2479                 dev     = packet_cached_dev_get(po);
2480                 proto   = po->num;
2481                 addr    = NULL;
2482         } else {
2483                 err = -EINVAL;
2484                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2485                         goto out;
2486                 if (msg->msg_namelen < (saddr->sll_halen
2487                                         + offsetof(struct sockaddr_ll,
2488                                                 sll_addr)))
2489                         goto out;
2490                 proto   = saddr->sll_protocol;
2491                 addr    = saddr->sll_addr;
2492                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2493         }
2494
2495         err = -ENXIO;
2496         if (unlikely(dev == NULL))
2497                 goto out;
2498         err = -ENETDOWN;
2499         if (unlikely(!(dev->flags & IFF_UP)))
2500                 goto out_put;
2501
2502         reserve = dev->hard_header_len + VLAN_HLEN;
2503         size_max = po->tx_ring.frame_size
2504                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2505
2506         if (size_max > dev->mtu + reserve)
2507                 size_max = dev->mtu + reserve;
2508
2509         do {
2510                 ph = packet_current_frame(po, &po->tx_ring,
2511                                           TP_STATUS_SEND_REQUEST);
2512                 if (unlikely(ph == NULL)) {
2513                         if (need_wait && need_resched())
2514                                 schedule();
2515                         continue;
2516                 }
2517
2518                 status = TP_STATUS_SEND_REQUEST;
2519                 hlen = LL_RESERVED_SPACE(dev);
2520                 tlen = dev->needed_tailroom;
2521                 skb = sock_alloc_send_skb(&po->sk,
2522                                 hlen + tlen + sizeof(struct sockaddr_ll),
2523                                 !need_wait, &err);
2524
2525                 if (unlikely(skb == NULL)) {
2526                         /* we assume the socket was initially writeable ... */
2527                         if (likely(len_sum > 0))
2528                                 err = len_sum;
2529                         goto out_status;
2530                 }
2531                 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2532                                           addr, hlen);
2533                 if (likely(tp_len >= 0) &&
2534                     tp_len > dev->mtu + dev->hard_header_len &&
2535                     !packet_extra_vlan_len_allowed(dev, skb))
2536                         tp_len = -EMSGSIZE;
2537
2538                 if (unlikely(tp_len < 0)) {
2539                         if (po->tp_loss) {
2540                                 __packet_set_status(po, ph,
2541                                                 TP_STATUS_AVAILABLE);
2542                                 packet_increment_head(&po->tx_ring);
2543                                 kfree_skb(skb);
2544                                 continue;
2545                         } else {
2546                                 status = TP_STATUS_WRONG_FORMAT;
2547                                 err = tp_len;
2548                                 goto out_status;
2549                         }
2550                 }
2551
2552                 packet_pick_tx_queue(dev, skb);
2553
2554                 skb->destructor = tpacket_destruct_skb;
2555                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2556                 packet_inc_pending(&po->tx_ring);
2557
2558                 status = TP_STATUS_SEND_REQUEST;
2559                 err = po->xmit(skb);
2560                 if (unlikely(err > 0)) {
2561                         err = net_xmit_errno(err);
2562                         if (err && __packet_get_status(po, ph) ==
2563                                    TP_STATUS_AVAILABLE) {
2564                                 /* skb was destructed already */
2565                                 skb = NULL;
2566                                 goto out_status;
2567                         }
2568                         /*
2569                          * skb was dropped but not destructed yet;
2570                          * let's treat it like congestion or err < 0
2571                          */
2572                         err = 0;
2573                 }
2574                 packet_increment_head(&po->tx_ring);
2575                 len_sum += tp_len;
2576         } while (likely((ph != NULL) ||
2577                 /* Note: packet_read_pending() might be slow if we have
2578                  * to call it as it's per_cpu variable, but in fast-path
2579                  * we already short-circuit the loop with the first
2580                  * condition, and luckily don't have to go that path
2581                  * anyway.
2582                  */
2583                  (need_wait && packet_read_pending(&po->tx_ring))));
2584
2585         err = len_sum;
2586         goto out_put;
2587
2588 out_status:
2589         __packet_set_status(po, ph, status);
2590         kfree_skb(skb);
2591 out_put:
2592         dev_put(dev);
2593 out:
2594         mutex_unlock(&po->pg_vec_lock);
2595         return err;
2596 }
2597
2598 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2599                                         size_t reserve, size_t len,
2600                                         size_t linear, int noblock,
2601                                         int *err)
2602 {
2603         struct sk_buff *skb;
2604
2605         /* Under a page?  Don't bother with paged skb. */
2606         if (prepad + len < PAGE_SIZE || !linear)
2607                 linear = len;
2608
2609         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2610                                    err, 0);
2611         if (!skb)
2612                 return NULL;
2613
2614         skb_reserve(skb, reserve);
2615         skb_put(skb, linear);
2616         skb->data_len = len - linear;
2617         skb->len += len - linear;
2618
2619         return skb;
2620 }
2621
2622 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2623 {
2624         struct sock *sk = sock->sk;
2625         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2626         struct sk_buff *skb;
2627         struct net_device *dev;
2628         __be16 proto;
2629         unsigned char *addr;
2630         int err, reserve = 0;
2631         struct sockcm_cookie sockc;
2632         struct virtio_net_hdr vnet_hdr = { 0 };
2633         int offset = 0;
2634         int vnet_hdr_len;
2635         struct packet_sock *po = pkt_sk(sk);
2636         unsigned short gso_type = 0;
2637         int hlen, tlen;
2638         int extra_len = 0;
2639         ssize_t n;
2640
2641         /*
2642          *      Get and verify the address.
2643          */
2644
2645         if (likely(saddr == NULL)) {
2646                 dev     = packet_cached_dev_get(po);
2647                 proto   = po->num;
2648                 addr    = NULL;
2649         } else {
2650                 err = -EINVAL;
2651                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2652                         goto out;
2653                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2654                         goto out;
2655                 proto   = saddr->sll_protocol;
2656                 addr    = saddr->sll_addr;
2657                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2658         }
2659
2660         err = -ENXIO;
2661         if (unlikely(dev == NULL))
2662                 goto out_unlock;
2663         err = -ENETDOWN;
2664         if (unlikely(!(dev->flags & IFF_UP)))
2665                 goto out_unlock;
2666
2667         sockc.mark = sk->sk_mark;
2668         if (msg->msg_controllen) {
2669                 err = sock_cmsg_send(sk, msg, &sockc);
2670                 if (unlikely(err))
2671                         goto out_unlock;
2672         }
2673
2674         if (sock->type == SOCK_RAW)
2675                 reserve = dev->hard_header_len;
2676         if (po->has_vnet_hdr) {
2677                 vnet_hdr_len = sizeof(vnet_hdr);
2678
2679                 err = -EINVAL;
2680                 if (len < vnet_hdr_len)
2681                         goto out_unlock;
2682
2683                 len -= vnet_hdr_len;
2684
2685                 err = -EFAULT;
2686                 n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &msg->msg_iter);
2687                 if (n != vnet_hdr_len)
2688                         goto out_unlock;
2689
2690                 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2691                     (__virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) +
2692                      __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2 >
2693                       __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len)))
2694                         vnet_hdr.hdr_len = __cpu_to_virtio16(vio_le(),
2695                                  __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start) +
2696                                 __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset) + 2);
2697
2698                 err = -EINVAL;
2699                 if (__virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len) > len)
2700                         goto out_unlock;
2701
2702                 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2703                         switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2704                         case VIRTIO_NET_HDR_GSO_TCPV4:
2705                                 gso_type = SKB_GSO_TCPV4;
2706                                 break;
2707                         case VIRTIO_NET_HDR_GSO_TCPV6:
2708                                 gso_type = SKB_GSO_TCPV6;
2709                                 break;
2710                         case VIRTIO_NET_HDR_GSO_UDP:
2711                                 gso_type = SKB_GSO_UDP;
2712                                 break;
2713                         default:
2714                                 goto out_unlock;
2715                         }
2716
2717                         if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2718                                 gso_type |= SKB_GSO_TCP_ECN;
2719
2720                         if (vnet_hdr.gso_size == 0)
2721                                 goto out_unlock;
2722
2723                 }
2724         }
2725
2726         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2727                 if (!netif_supports_nofcs(dev)) {
2728                         err = -EPROTONOSUPPORT;
2729                         goto out_unlock;
2730                 }
2731                 extra_len = 4; /* We're doing our own CRC */
2732         }
2733
2734         err = -EMSGSIZE;
2735         if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2736                 goto out_unlock;
2737
2738         err = -ENOBUFS;
2739         hlen = LL_RESERVED_SPACE(dev);
2740         tlen = dev->needed_tailroom;
2741         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len,
2742                                __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len),
2743                                msg->msg_flags & MSG_DONTWAIT, &err);
2744         if (skb == NULL)
2745                 goto out_unlock;
2746
2747         skb_set_network_header(skb, reserve);
2748
2749         err = -EINVAL;
2750         if (sock->type == SOCK_DGRAM) {
2751                 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2752                 if (unlikely(offset < 0))
2753                         goto out_free;
2754         } else {
2755                 if (ll_header_truncated(dev, len))
2756                         goto out_free;
2757         }
2758
2759         /* Returns -EFAULT on error */
2760         err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2761         if (err)
2762                 goto out_free;
2763
2764         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2765
2766         if (!gso_type && (len > dev->mtu + reserve + extra_len) &&
2767             !packet_extra_vlan_len_allowed(dev, skb)) {
2768                 err = -EMSGSIZE;
2769                 goto out_free;
2770         }
2771
2772         skb->protocol = proto;
2773         skb->dev = dev;
2774         skb->priority = sk->sk_priority;
2775         skb->mark = sockc.mark;
2776
2777         packet_pick_tx_queue(dev, skb);
2778
2779         if (po->has_vnet_hdr) {
2780                 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2781                         u16 s = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_start);
2782                         u16 o = __virtio16_to_cpu(vio_le(), vnet_hdr.csum_offset);
2783                         if (!skb_partial_csum_set(skb, s, o)) {
2784                                 err = -EINVAL;
2785                                 goto out_free;
2786                         }
2787                 }
2788
2789                 skb_shinfo(skb)->gso_size =
2790                         __virtio16_to_cpu(vio_le(), vnet_hdr.gso_size);
2791                 skb_shinfo(skb)->gso_type = gso_type;
2792
2793                 /* Header must be checked, and gso_segs computed. */
2794                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2795                 skb_shinfo(skb)->gso_segs = 0;
2796
2797                 len += vnet_hdr_len;
2798         }
2799
2800         skb_probe_transport_header(skb, reserve);
2801
2802         if (unlikely(extra_len == 4))
2803                 skb->no_fcs = 1;
2804
2805         err = po->xmit(skb);
2806         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2807                 goto out_unlock;
2808
2809         dev_put(dev);
2810
2811         return len;
2812
2813 out_free:
2814         kfree_skb(skb);
2815 out_unlock:
2816         if (dev)
2817                 dev_put(dev);
2818 out:
2819         return err;
2820 }
2821
2822 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2823 {
2824         struct sock *sk = sock->sk;
2825         struct packet_sock *po = pkt_sk(sk);
2826
2827         if (po->tx_ring.pg_vec)
2828                 return tpacket_snd(po, msg);
2829         else
2830                 return packet_snd(sock, msg, len);
2831 }
2832
2833 /*
2834  *      Close a PACKET socket. This is fairly simple. We immediately go
2835  *      to 'closed' state and remove our protocol entry in the device list.
2836  */
2837
2838 static int packet_release(struct socket *sock)
2839 {
2840         struct sock *sk = sock->sk;
2841         struct packet_sock *po;
2842         struct net *net;
2843         union tpacket_req_u req_u;
2844
2845         if (!sk)
2846                 return 0;
2847
2848         net = sock_net(sk);
2849         po = pkt_sk(sk);
2850
2851         mutex_lock(&net->packet.sklist_lock);
2852         sk_del_node_init_rcu(sk);
2853         mutex_unlock(&net->packet.sklist_lock);
2854
2855         preempt_disable();
2856         sock_prot_inuse_add(net, sk->sk_prot, -1);
2857         preempt_enable();
2858
2859         spin_lock(&po->bind_lock);
2860         unregister_prot_hook(sk, false);
2861         packet_cached_dev_reset(po);
2862
2863         if (po->prot_hook.dev) {
2864                 dev_put(po->prot_hook.dev);
2865                 po->prot_hook.dev = NULL;
2866         }
2867         spin_unlock(&po->bind_lock);
2868
2869         packet_flush_mclist(sk);
2870
2871         if (po->rx_ring.pg_vec) {
2872                 memset(&req_u, 0, sizeof(req_u));
2873                 packet_set_ring(sk, &req_u, 1, 0);
2874         }
2875
2876         if (po->tx_ring.pg_vec) {
2877                 memset(&req_u, 0, sizeof(req_u));
2878                 packet_set_ring(sk, &req_u, 1, 1);
2879         }
2880
2881         fanout_release(sk);
2882
2883         synchronize_net();
2884         /*
2885          *      Now the socket is dead. No more input will appear.
2886          */
2887         sock_orphan(sk);
2888         sock->sk = NULL;
2889
2890         /* Purge queues */
2891
2892         skb_queue_purge(&sk->sk_receive_queue);
2893         packet_free_pending(po);
2894         sk_refcnt_debug_release(sk);
2895
2896         sock_put(sk);
2897         return 0;
2898 }
2899
2900 /*
2901  *      Attach a packet hook.
2902  */
2903
2904 static int packet_do_bind(struct sock *sk, const char *name, int ifindex,
2905                           __be16 proto)
2906 {
2907         struct packet_sock *po = pkt_sk(sk);
2908         struct net_device *dev_curr;
2909         __be16 proto_curr;
2910         bool need_rehook;
2911         struct net_device *dev = NULL;
2912         int ret = 0;
2913         bool unlisted = false;
2914
2915         if (po->fanout)
2916                 return -EINVAL;
2917
2918         lock_sock(sk);
2919         spin_lock(&po->bind_lock);
2920         rcu_read_lock();
2921
2922         if (name) {
2923                 dev = dev_get_by_name_rcu(sock_net(sk), name);
2924                 if (!dev) {
2925                         ret = -ENODEV;
2926                         goto out_unlock;
2927                 }
2928         } else if (ifindex) {
2929                 dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
2930                 if (!dev) {
2931                         ret = -ENODEV;
2932                         goto out_unlock;
2933                 }
2934         }
2935
2936         if (dev)
2937                 dev_hold(dev);
2938
2939         proto_curr = po->prot_hook.type;
2940         dev_curr = po->prot_hook.dev;
2941
2942         need_rehook = proto_curr != proto || dev_curr != dev;
2943
2944         if (need_rehook) {
2945                 if (po->running) {
2946                         rcu_read_unlock();
2947                         __unregister_prot_hook(sk, true);
2948                         rcu_read_lock();
2949                         dev_curr = po->prot_hook.dev;
2950                         if (dev)
2951                                 unlisted = !dev_get_by_index_rcu(sock_net(sk),
2952                                                                  dev->ifindex);
2953                 }
2954
2955                 po->num = proto;
2956                 po->prot_hook.type = proto;
2957
2958                 if (unlikely(unlisted)) {
2959                         dev_put(dev);
2960                         po->prot_hook.dev = NULL;
2961                         po->ifindex = -1;
2962                         packet_cached_dev_reset(po);
2963                 } else {
2964                         po->prot_hook.dev = dev;
2965                         po->ifindex = dev ? dev->ifindex : 0;
2966                         packet_cached_dev_assign(po, dev);
2967                 }
2968         }
2969         if (dev_curr)
2970                 dev_put(dev_curr);
2971
2972         if (proto == 0 || !need_rehook)
2973                 goto out_unlock;
2974
2975         if (!unlisted && (!dev || (dev->flags & IFF_UP))) {
2976                 register_prot_hook(sk);
2977         } else {
2978                 sk->sk_err = ENETDOWN;
2979                 if (!sock_flag(sk, SOCK_DEAD))
2980                         sk->sk_error_report(sk);
2981         }
2982
2983 out_unlock:
2984         rcu_read_unlock();
2985         spin_unlock(&po->bind_lock);
2986         release_sock(sk);
2987         return ret;
2988 }
2989
2990 /*
2991  *      Bind a packet socket to a device
2992  */
2993
2994 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2995                             int addr_len)
2996 {
2997         struct sock *sk = sock->sk;
2998         char name[15];
2999
3000         /*
3001          *      Check legality
3002          */
3003
3004         if (addr_len != sizeof(struct sockaddr))
3005                 return -EINVAL;
3006         strlcpy(name, uaddr->sa_data, sizeof(name));
3007
3008         return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
3009 }
3010
3011 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
3012 {
3013         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
3014         struct sock *sk = sock->sk;
3015
3016         /*
3017          *      Check legality
3018          */
3019
3020         if (addr_len < sizeof(struct sockaddr_ll))
3021                 return -EINVAL;
3022         if (sll->sll_family != AF_PACKET)
3023                 return -EINVAL;
3024
3025         return packet_do_bind(sk, NULL, sll->sll_ifindex,
3026                               sll->sll_protocol ? : pkt_sk(sk)->num);
3027 }
3028
3029 static struct proto packet_proto = {
3030         .name     = "PACKET",
3031         .owner    = THIS_MODULE,
3032         .obj_size = sizeof(struct packet_sock),
3033 };
3034
3035 /*
3036  *      Create a packet of type SOCK_PACKET.
3037  */
3038
3039 static int packet_create(struct net *net, struct socket *sock, int protocol,
3040                          int kern)
3041 {
3042         struct sock *sk;
3043         struct packet_sock *po;
3044         __be16 proto = (__force __be16)protocol; /* weird, but documented */
3045         int err;
3046
3047         if (!ns_capable(net->user_ns, CAP_NET_RAW))
3048                 return -EPERM;
3049         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
3050             sock->type != SOCK_PACKET)
3051                 return -ESOCKTNOSUPPORT;
3052
3053         sock->state = SS_UNCONNECTED;
3054
3055         err = -ENOBUFS;
3056         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
3057         if (sk == NULL)
3058                 goto out;
3059
3060         sock->ops = &packet_ops;
3061         if (sock->type == SOCK_PACKET)
3062                 sock->ops = &packet_ops_spkt;
3063
3064         sock_init_data(sock, sk);
3065
3066         po = pkt_sk(sk);
3067         sk->sk_family = PF_PACKET;
3068         po->num = proto;
3069         po->xmit = dev_queue_xmit;
3070
3071         err = packet_alloc_pending(po);
3072         if (err)
3073                 goto out2;
3074
3075         packet_cached_dev_reset(po);
3076
3077         sk->sk_destruct = packet_sock_destruct;
3078         sk_refcnt_debug_inc(sk);
3079
3080         /*
3081          *      Attach a protocol block
3082          */
3083
3084         spin_lock_init(&po->bind_lock);
3085         mutex_init(&po->pg_vec_lock);
3086         po->rollover = NULL;
3087         po->prot_hook.func = packet_rcv;
3088
3089         if (sock->type == SOCK_PACKET)
3090                 po->prot_hook.func = packet_rcv_spkt;
3091
3092         po->prot_hook.af_packet_priv = sk;
3093
3094         if (proto) {
3095                 po->prot_hook.type = proto;
3096                 register_prot_hook(sk);
3097         }
3098
3099         mutex_lock(&net->packet.sklist_lock);
3100         sk_add_node_rcu(sk, &net->packet.sklist);
3101         mutex_unlock(&net->packet.sklist_lock);
3102
3103         preempt_disable();
3104         sock_prot_inuse_add(net, &packet_proto, 1);
3105         preempt_enable();
3106
3107         return 0;
3108 out2:
3109         sk_free(sk);
3110 out:
3111         return err;
3112 }
3113
3114 /*
3115  *      Pull a packet from our receive queue and hand it to the user.
3116  *      If necessary we block.
3117  */
3118
3119 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
3120                           int flags)
3121 {
3122         struct sock *sk = sock->sk;
3123         struct sk_buff *skb;
3124         int copied, err;
3125         int vnet_hdr_len = 0;
3126         unsigned int origlen = 0;
3127
3128         err = -EINVAL;
3129         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3130                 goto out;
3131
3132 #if 0
3133         /* What error should we return now? EUNATTACH? */
3134         if (pkt_sk(sk)->ifindex < 0)
3135                 return -ENODEV;
3136 #endif
3137
3138         if (flags & MSG_ERRQUEUE) {
3139                 err = sock_recv_errqueue(sk, msg, len,
3140                                          SOL_PACKET, PACKET_TX_TIMESTAMP);
3141                 goto out;
3142         }
3143
3144         /*
3145          *      Call the generic datagram receiver. This handles all sorts
3146          *      of horrible races and re-entrancy so we can forget about it
3147          *      in the protocol layers.
3148          *
3149          *      Now it will return ENETDOWN, if device have just gone down,
3150          *      but then it will block.
3151          */
3152
3153         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3154
3155         /*
3156          *      An error occurred so return it. Because skb_recv_datagram()
3157          *      handles the blocking we don't see and worry about blocking
3158          *      retries.
3159          */
3160
3161         if (skb == NULL)
3162                 goto out;
3163
3164         if (pkt_sk(sk)->pressure)
3165                 packet_rcv_has_room(pkt_sk(sk), NULL);
3166
3167         if (pkt_sk(sk)->has_vnet_hdr) {
3168                 struct virtio_net_hdr vnet_hdr = { 0 };
3169
3170                 err = -EINVAL;
3171                 vnet_hdr_len = sizeof(vnet_hdr);
3172                 if (len < vnet_hdr_len)
3173                         goto out_free;
3174
3175                 len -= vnet_hdr_len;
3176
3177                 if (skb_is_gso(skb)) {
3178                         struct skb_shared_info *sinfo = skb_shinfo(skb);
3179
3180                         /* This is a hint as to how much should be linear. */
3181                         vnet_hdr.hdr_len =
3182                                 __cpu_to_virtio16(vio_le(), skb_headlen(skb));
3183                         vnet_hdr.gso_size =
3184                                 __cpu_to_virtio16(vio_le(), sinfo->gso_size);
3185                         if (sinfo->gso_type & SKB_GSO_TCPV4)
3186                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
3187                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
3188                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
3189                         else if (sinfo->gso_type & SKB_GSO_UDP)
3190                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
3191                         else if (sinfo->gso_type & SKB_GSO_FCOE)
3192                                 goto out_free;
3193                         else
3194                                 BUG();
3195                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
3196                                 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
3197                 } else
3198                         vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
3199
3200                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
3201                         vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
3202                         vnet_hdr.csum_start = __cpu_to_virtio16(vio_le(),
3203                                           skb_checksum_start_offset(skb));
3204                         vnet_hdr.csum_offset = __cpu_to_virtio16(vio_le(),
3205                                                          skb->csum_offset);
3206                 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
3207                         vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
3208                 } /* else everything is zero */
3209
3210                 err = memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_len);
3211                 if (err < 0)
3212                         goto out_free;
3213         }
3214
3215         /* You lose any data beyond the buffer you gave. If it worries
3216          * a user program they can ask the device for its MTU
3217          * anyway.
3218          */
3219         copied = skb->len;
3220         if (copied > len) {
3221                 copied = len;
3222                 msg->msg_flags |= MSG_TRUNC;
3223         }
3224
3225         err = skb_copy_datagram_msg(skb, 0, msg, copied);
3226         if (err)
3227                 goto out_free;
3228
3229         if (sock->type != SOCK_PACKET) {
3230                 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3231
3232                 /* Original length was stored in sockaddr_ll fields */
3233                 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3234                 sll->sll_family = AF_PACKET;
3235                 sll->sll_protocol = skb->protocol;
3236         }
3237
3238         sock_recv_ts_and_drops(msg, sk, skb);
3239
3240         if (msg->msg_name) {
3241                 /* If the address length field is there to be filled
3242                  * in, we fill it in now.
3243                  */
3244                 if (sock->type == SOCK_PACKET) {
3245                         __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3246                         msg->msg_namelen = sizeof(struct sockaddr_pkt);
3247                 } else {
3248                         struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3249
3250                         msg->msg_namelen = sll->sll_halen +
3251                                 offsetof(struct sockaddr_ll, sll_addr);
3252                 }
3253                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3254                        msg->msg_namelen);
3255         }
3256
3257         if (pkt_sk(sk)->auxdata) {
3258                 struct tpacket_auxdata aux;
3259
3260                 aux.tp_status = TP_STATUS_USER;
3261                 if (skb->ip_summed == CHECKSUM_PARTIAL)
3262                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3263                 else if (skb->pkt_type != PACKET_OUTGOING &&
3264                          (skb->ip_summed == CHECKSUM_COMPLETE ||
3265                           skb_csum_unnecessary(skb)))
3266                         aux.tp_status |= TP_STATUS_CSUM_VALID;
3267
3268                 aux.tp_len = origlen;
3269                 aux.tp_snaplen = skb->len;
3270                 aux.tp_mac = 0;
3271                 aux.tp_net = skb_network_offset(skb);
3272                 if (skb_vlan_tag_present(skb)) {
3273                         aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3274                         aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3275                         aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3276                 } else {
3277                         aux.tp_vlan_tci = 0;
3278                         aux.tp_vlan_tpid = 0;
3279                 }
3280                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3281         }
3282
3283         /*
3284          *      Free or return the buffer as appropriate. Again this
3285          *      hides all the races and re-entrancy issues from us.
3286          */
3287         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3288
3289 out_free:
3290         skb_free_datagram(sk, skb);
3291 out:
3292         return err;
3293 }
3294
3295 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3296                                int *uaddr_len, int peer)
3297 {
3298         struct net_device *dev;
3299         struct sock *sk = sock->sk;
3300
3301         if (peer)
3302                 return -EOPNOTSUPP;
3303
3304         uaddr->sa_family = AF_PACKET;
3305         memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3306         rcu_read_lock();
3307         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3308         if (dev)
3309                 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3310         rcu_read_unlock();
3311         *uaddr_len = sizeof(*uaddr);
3312
3313         return 0;
3314 }
3315
3316 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3317                           int *uaddr_len, int peer)
3318 {
3319         struct net_device *dev;
3320         struct sock *sk = sock->sk;
3321         struct packet_sock *po = pkt_sk(sk);
3322         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3323
3324         if (peer)
3325                 return -EOPNOTSUPP;
3326
3327         sll->sll_family = AF_PACKET;
3328         sll->sll_ifindex = po->ifindex;
3329         sll->sll_protocol = po->num;
3330         sll->sll_pkttype = 0;
3331         rcu_read_lock();
3332         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3333         if (dev) {
3334                 sll->sll_hatype = dev->type;
3335                 sll->sll_halen = dev->addr_len;
3336                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3337         } else {
3338                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
3339                 sll->sll_halen = 0;
3340         }
3341         rcu_read_unlock();
3342         *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3343
3344         return 0;
3345 }
3346
3347 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3348                          int what)
3349 {
3350         switch (i->type) {
3351         case PACKET_MR_MULTICAST:
3352                 if (i->alen != dev->addr_len)
3353                         return -EINVAL;
3354                 if (what > 0)
3355                         return dev_mc_add(dev, i->addr);
3356                 else
3357                         return dev_mc_del(dev, i->addr);
3358                 break;
3359         case PACKET_MR_PROMISC:
3360                 return dev_set_promiscuity(dev, what);
3361         case PACKET_MR_ALLMULTI:
3362                 return dev_set_allmulti(dev, what);
3363         case PACKET_MR_UNICAST:
3364                 if (i->alen != dev->addr_len)
3365                         return -EINVAL;
3366                 if (what > 0)
3367                         return dev_uc_add(dev, i->addr);
3368                 else
3369                         return dev_uc_del(dev, i->addr);
3370                 break;
3371         default:
3372                 break;
3373         }
3374         return 0;
3375 }
3376
3377 static void packet_dev_mclist_delete(struct net_device *dev,
3378                                      struct packet_mclist **mlp)
3379 {
3380         struct packet_mclist *ml;
3381
3382         while ((ml = *mlp) != NULL) {
3383                 if (ml->ifindex == dev->ifindex) {
3384                         packet_dev_mc(dev, ml, -1);
3385                         *mlp = ml->next;
3386                         kfree(ml);
3387                 } else
3388                         mlp = &ml->next;
3389         }
3390 }
3391
3392 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3393 {
3394         struct packet_sock *po = pkt_sk(sk);
3395         struct packet_mclist *ml, *i;
3396         struct net_device *dev;
3397         int err;
3398
3399         rtnl_lock();
3400
3401         err = -ENODEV;
3402         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3403         if (!dev)
3404                 goto done;
3405
3406         err = -EINVAL;
3407         if (mreq->mr_alen > dev->addr_len)
3408                 goto done;
3409
3410         err = -ENOBUFS;
3411         i = kmalloc(sizeof(*i), GFP_KERNEL);
3412         if (i == NULL)
3413                 goto done;
3414
3415         err = 0;
3416         for (ml = po->mclist; ml; ml = ml->next) {
3417                 if (ml->ifindex == mreq->mr_ifindex &&
3418                     ml->type == mreq->mr_type &&
3419                     ml->alen == mreq->mr_alen &&
3420                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3421                         ml->count++;
3422                         /* Free the new element ... */
3423                         kfree(i);
3424                         goto done;
3425                 }
3426         }
3427
3428         i->type = mreq->mr_type;
3429         i->ifindex = mreq->mr_ifindex;
3430         i->alen = mreq->mr_alen;
3431         memcpy(i->addr, mreq->mr_address, i->alen);
3432         i->count = 1;
3433         i->next = po->mclist;
3434         po->mclist = i;
3435         err = packet_dev_mc(dev, i, 1);
3436         if (err) {
3437                 po->mclist = i->next;
3438                 kfree(i);
3439         }
3440
3441 done:
3442         rtnl_unlock();
3443         return err;
3444 }
3445
3446 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3447 {
3448         struct packet_mclist *ml, **mlp;
3449
3450         rtnl_lock();
3451
3452         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3453                 if (ml->ifindex == mreq->mr_ifindex &&
3454                     ml->type == mreq->mr_type &&
3455                     ml->alen == mreq->mr_alen &&
3456                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3457                         if (--ml->count == 0) {
3458                                 struct net_device *dev;
3459                                 *mlp = ml->next;
3460                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3461                                 if (dev)
3462                                         packet_dev_mc(dev, ml, -1);
3463                                 kfree(ml);
3464                         }
3465                         break;
3466                 }
3467         }
3468         rtnl_unlock();
3469         return 0;
3470 }
3471
3472 static void packet_flush_mclist(struct sock *sk)
3473 {
3474         struct packet_sock *po = pkt_sk(sk);
3475         struct packet_mclist *ml;
3476
3477         if (!po->mclist)
3478                 return;
3479
3480         rtnl_lock();
3481         while ((ml = po->mclist) != NULL) {
3482                 struct net_device *dev;
3483
3484                 po->mclist = ml->next;
3485                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3486                 if (dev != NULL)
3487                         packet_dev_mc(dev, ml, -1);
3488                 kfree(ml);
3489         }
3490         rtnl_unlock();
3491 }
3492
3493 static int
3494 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3495 {
3496         struct sock *sk = sock->sk;
3497         struct packet_sock *po = pkt_sk(sk);
3498         int ret;
3499
3500         if (level != SOL_PACKET)
3501                 return -ENOPROTOOPT;
3502
3503         switch (optname) {
3504         case PACKET_ADD_MEMBERSHIP:
3505         case PACKET_DROP_MEMBERSHIP:
3506         {
3507                 struct packet_mreq_max mreq;
3508                 int len = optlen;
3509                 memset(&mreq, 0, sizeof(mreq));
3510                 if (len < sizeof(struct packet_mreq))
3511                         return -EINVAL;
3512                 if (len > sizeof(mreq))
3513                         len = sizeof(mreq);
3514                 if (copy_from_user(&mreq, optval, len))
3515                         return -EFAULT;
3516                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3517                         return -EINVAL;
3518                 if (optname == PACKET_ADD_MEMBERSHIP)
3519                         ret = packet_mc_add(sk, &mreq);
3520                 else
3521                         ret = packet_mc_drop(sk, &mreq);
3522                 return ret;
3523         }
3524
3525         case PACKET_RX_RING:
3526         case PACKET_TX_RING:
3527         {
3528                 union tpacket_req_u req_u;
3529                 int len;
3530
3531                 switch (po->tp_version) {
3532                 case TPACKET_V1:
3533                 case TPACKET_V2:
3534                         len = sizeof(req_u.req);
3535                         break;
3536                 case TPACKET_V3:
3537                 default:
3538                         len = sizeof(req_u.req3);
3539                         break;
3540                 }
3541                 if (optlen < len)
3542                         return -EINVAL;
3543                 if (pkt_sk(sk)->has_vnet_hdr)
3544                         return -EINVAL;
3545                 if (copy_from_user(&req_u.req, optval, len))
3546                         return -EFAULT;
3547                 return packet_set_ring(sk, &req_u, 0,
3548                         optname == PACKET_TX_RING);
3549         }
3550         case PACKET_COPY_THRESH:
3551         {
3552                 int val;
3553
3554                 if (optlen != sizeof(val))
3555                         return -EINVAL;
3556                 if (copy_from_user(&val, optval, sizeof(val)))
3557                         return -EFAULT;
3558
3559                 pkt_sk(sk)->copy_thresh = val;
3560                 return 0;
3561         }
3562         case PACKET_VERSION:
3563         {
3564                 int val;
3565
3566                 if (optlen != sizeof(val))
3567                         return -EINVAL;
3568                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3569                         return -EBUSY;
3570                 if (copy_from_user(&val, optval, sizeof(val)))
3571                         return -EFAULT;
3572                 switch (val) {
3573                 case TPACKET_V1:
3574                 case TPACKET_V2:
3575                 case TPACKET_V3:
3576                         po->tp_version = val;
3577                         return 0;
3578                 default:
3579                         return -EINVAL;
3580                 }
3581         }
3582         case PACKET_RESERVE:
3583         {
3584                 unsigned int val;
3585
3586                 if (optlen != sizeof(val))
3587                         return -EINVAL;
3588                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3589                         return -EBUSY;
3590                 if (copy_from_user(&val, optval, sizeof(val)))
3591                         return -EFAULT;
3592                 po->tp_reserve = val;
3593                 return 0;
3594         }
3595         case PACKET_LOSS:
3596         {
3597                 unsigned int val;
3598
3599                 if (optlen != sizeof(val))
3600                         return -EINVAL;
3601                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3602                         return -EBUSY;
3603                 if (copy_from_user(&val, optval, sizeof(val)))
3604                         return -EFAULT;
3605                 po->tp_loss = !!val;
3606                 return 0;
3607         }
3608         case PACKET_AUXDATA:
3609         {
3610                 int val;
3611
3612                 if (optlen < sizeof(val))
3613                         return -EINVAL;
3614                 if (copy_from_user(&val, optval, sizeof(val)))
3615                         return -EFAULT;
3616
3617                 po->auxdata = !!val;
3618                 return 0;
3619         }
3620         case PACKET_ORIGDEV:
3621         {
3622                 int val;
3623
3624                 if (optlen < sizeof(val))
3625                         return -EINVAL;
3626                 if (copy_from_user(&val, optval, sizeof(val)))
3627                         return -EFAULT;
3628
3629                 po->origdev = !!val;
3630                 return 0;
3631         }
3632         case PACKET_VNET_HDR:
3633         {
3634                 int val;
3635
3636                 if (sock->type != SOCK_RAW)
3637                         return -EINVAL;
3638                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3639                         return -EBUSY;
3640                 if (optlen < sizeof(val))
3641                         return -EINVAL;
3642                 if (copy_from_user(&val, optval, sizeof(val)))
3643                         return -EFAULT;
3644
3645                 po->has_vnet_hdr = !!val;
3646                 return 0;
3647         }
3648         case PACKET_TIMESTAMP:
3649         {
3650                 int val;
3651
3652                 if (optlen != sizeof(val))
3653                         return -EINVAL;
3654                 if (copy_from_user(&val, optval, sizeof(val)))
3655                         return -EFAULT;
3656
3657                 po->tp_tstamp = val;
3658                 return 0;
3659         }
3660         case PACKET_FANOUT:
3661         {
3662                 int val;
3663
3664                 if (optlen != sizeof(val))
3665                         return -EINVAL;
3666                 if (copy_from_user(&val, optval, sizeof(val)))
3667                         return -EFAULT;
3668
3669                 return fanout_add(sk, val & 0xffff, val >> 16);
3670         }
3671         case PACKET_FANOUT_DATA:
3672         {
3673                 if (!po->fanout)
3674                         return -EINVAL;
3675
3676                 return fanout_set_data(po, optval, optlen);
3677         }
3678         case PACKET_TX_HAS_OFF:
3679         {
3680                 unsigned int val;
3681
3682                 if (optlen != sizeof(val))
3683                         return -EINVAL;
3684                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3685                         return -EBUSY;
3686                 if (copy_from_user(&val, optval, sizeof(val)))
3687                         return -EFAULT;
3688                 po->tp_tx_has_off = !!val;
3689                 return 0;
3690         }
3691         case PACKET_QDISC_BYPASS:
3692         {
3693                 int val;
3694
3695                 if (optlen != sizeof(val))
3696                         return -EINVAL;
3697                 if (copy_from_user(&val, optval, sizeof(val)))
3698                         return -EFAULT;
3699
3700                 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3701                 return 0;
3702         }
3703         default:
3704                 return -ENOPROTOOPT;
3705         }
3706 }
3707
3708 static int packet_getsockopt(struct socket *sock, int level, int optname,
3709                              char __user *optval, int __user *optlen)
3710 {
3711         int len;
3712         int val, lv = sizeof(val);
3713         struct sock *sk = sock->sk;
3714         struct packet_sock *po = pkt_sk(sk);
3715         void *data = &val;
3716         union tpacket_stats_u st;
3717         struct tpacket_rollover_stats rstats;
3718
3719         if (level != SOL_PACKET)
3720                 return -ENOPROTOOPT;
3721
3722         if (get_user(len, optlen))
3723                 return -EFAULT;
3724
3725         if (len < 0)
3726                 return -EINVAL;
3727
3728         switch (optname) {
3729         case PACKET_STATISTICS:
3730                 spin_lock_bh(&sk->sk_receive_queue.lock);
3731                 memcpy(&st, &po->stats, sizeof(st));
3732                 memset(&po->stats, 0, sizeof(po->stats));
3733                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3734
3735                 if (po->tp_version == TPACKET_V3) {
3736                         lv = sizeof(struct tpacket_stats_v3);
3737                         st.stats3.tp_packets += st.stats3.tp_drops;
3738                         data = &st.stats3;
3739                 } else {
3740                         lv = sizeof(struct tpacket_stats);
3741                         st.stats1.tp_packets += st.stats1.tp_drops;
3742                         data = &st.stats1;
3743                 }
3744
3745                 break;
3746         case PACKET_AUXDATA:
3747                 val = po->auxdata;
3748                 break;
3749         case PACKET_ORIGDEV:
3750                 val = po->origdev;
3751                 break;
3752         case PACKET_VNET_HDR:
3753                 val = po->has_vnet_hdr;
3754                 break;
3755         case PACKET_VERSION:
3756                 val = po->tp_version;
3757                 break;
3758         case PACKET_HDRLEN:
3759                 if (len > sizeof(int))
3760                         len = sizeof(int);
3761                 if (copy_from_user(&val, optval, len))
3762                         return -EFAULT;
3763                 switch (val) {
3764                 case TPACKET_V1:
3765                         val = sizeof(struct tpacket_hdr);
3766                         break;
3767                 case TPACKET_V2:
3768                         val = sizeof(struct tpacket2_hdr);
3769                         break;
3770                 case TPACKET_V3:
3771                         val = sizeof(struct tpacket3_hdr);
3772                         break;
3773                 default:
3774                         return -EINVAL;
3775                 }
3776                 break;
3777         case PACKET_RESERVE:
3778                 val = po->tp_reserve;
3779                 break;
3780         case PACKET_LOSS:
3781                 val = po->tp_loss;
3782                 break;
3783         case PACKET_TIMESTAMP:
3784                 val = po->tp_tstamp;
3785                 break;
3786         case PACKET_FANOUT:
3787                 val = (po->fanout ?
3788                        ((u32)po->fanout->id |
3789                         ((u32)po->fanout->type << 16) |
3790                         ((u32)po->fanout->flags << 24)) :
3791                        0);
3792                 break;
3793         case PACKET_ROLLOVER_STATS:
3794                 if (!po->rollover)
3795                         return -EINVAL;
3796                 rstats.tp_all = atomic_long_read(&po->rollover->num);
3797                 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3798                 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3799                 data = &rstats;
3800                 lv = sizeof(rstats);
3801                 break;
3802         case PACKET_TX_HAS_OFF:
3803                 val = po->tp_tx_has_off;
3804                 break;
3805         case PACKET_QDISC_BYPASS:
3806                 val = packet_use_direct_xmit(po);
3807                 break;
3808         default:
3809                 return -ENOPROTOOPT;
3810         }
3811
3812         if (len > lv)
3813                 len = lv;
3814         if (put_user(len, optlen))
3815                 return -EFAULT;
3816         if (copy_to_user(optval, data, len))
3817                 return -EFAULT;
3818         return 0;
3819 }
3820
3821
3822 static int packet_notifier(struct notifier_block *this,
3823                            unsigned long msg, void *ptr)
3824 {
3825         struct sock *sk;
3826         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3827         struct net *net = dev_net(dev);
3828
3829         rcu_read_lock();
3830         sk_for_each_rcu(sk, &net->packet.sklist) {
3831                 struct packet_sock *po = pkt_sk(sk);
3832
3833                 switch (msg) {
3834                 case NETDEV_UNREGISTER:
3835                         if (po->mclist)
3836                                 packet_dev_mclist_delete(dev, &po->mclist);
3837                         /* fallthrough */
3838
3839                 case NETDEV_DOWN:
3840                         if (dev->ifindex == po->ifindex) {
3841                                 spin_lock(&po->bind_lock);
3842                                 if (po->running) {
3843                                         __unregister_prot_hook(sk, false);
3844                                         sk->sk_err = ENETDOWN;
3845                                         if (!sock_flag(sk, SOCK_DEAD))
3846                                                 sk->sk_error_report(sk);
3847                                 }
3848                                 if (msg == NETDEV_UNREGISTER) {
3849                                         packet_cached_dev_reset(po);
3850                                         po->ifindex = -1;
3851                                         if (po->prot_hook.dev)
3852                                                 dev_put(po->prot_hook.dev);
3853                                         po->prot_hook.dev = NULL;
3854                                 }
3855                                 spin_unlock(&po->bind_lock);
3856                         }
3857                         break;
3858                 case NETDEV_UP:
3859                         if (dev->ifindex == po->ifindex) {
3860                                 spin_lock(&po->bind_lock);
3861                                 if (po->num)
3862                                         register_prot_hook(sk);
3863                                 spin_unlock(&po->bind_lock);
3864                         }
3865                         break;
3866                 }
3867         }
3868         rcu_read_unlock();
3869         return NOTIFY_DONE;
3870 }
3871
3872
3873 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3874                         unsigned long arg)
3875 {
3876         struct sock *sk = sock->sk;
3877
3878         switch (cmd) {
3879         case SIOCOUTQ:
3880         {
3881                 int amount = sk_wmem_alloc_get(sk);
3882
3883                 return put_user(amount, (int __user *)arg);
3884         }
3885         case SIOCINQ:
3886         {
3887                 struct sk_buff *skb;
3888                 int amount = 0;
3889
3890                 spin_lock_bh(&sk->sk_receive_queue.lock);
3891                 skb = skb_peek(&sk->sk_receive_queue);
3892                 if (skb)
3893                         amount = skb->len;
3894                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3895                 return put_user(amount, (int __user *)arg);
3896         }
3897         case SIOCGSTAMP:
3898                 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3899         case SIOCGSTAMPNS:
3900                 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3901
3902 #ifdef CONFIG_INET
3903         case SIOCADDRT:
3904         case SIOCDELRT:
3905         case SIOCDARP:
3906         case SIOCGARP:
3907         case SIOCSARP:
3908         case SIOCGIFADDR:
3909         case SIOCSIFADDR:
3910         case SIOCGIFBRDADDR:
3911         case SIOCSIFBRDADDR:
3912         case SIOCGIFNETMASK:
3913         case SIOCSIFNETMASK:
3914         case SIOCGIFDSTADDR:
3915         case SIOCSIFDSTADDR:
3916         case SIOCSIFFLAGS:
3917                 return inet_dgram_ops.ioctl(sock, cmd, arg);
3918 #endif
3919
3920         default:
3921                 return -ENOIOCTLCMD;
3922         }
3923         return 0;
3924 }
3925
3926 static unsigned int packet_poll(struct file *file, struct socket *sock,
3927                                 poll_table *wait)
3928 {
3929         struct sock *sk = sock->sk;
3930         struct packet_sock *po = pkt_sk(sk);
3931         unsigned int mask = datagram_poll(file, sock, wait);
3932
3933         spin_lock_bh(&sk->sk_receive_queue.lock);
3934         if (po->rx_ring.pg_vec) {
3935                 if (!packet_previous_rx_frame(po, &po->rx_ring,
3936                         TP_STATUS_KERNEL))
3937                         mask |= POLLIN | POLLRDNORM;
3938         }
3939         if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
3940                 po->pressure = 0;
3941         spin_unlock_bh(&sk->sk_receive_queue.lock);
3942         spin_lock_bh(&sk->sk_write_queue.lock);
3943         if (po->tx_ring.pg_vec) {
3944                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3945                         mask |= POLLOUT | POLLWRNORM;
3946         }
3947         spin_unlock_bh(&sk->sk_write_queue.lock);
3948         return mask;
3949 }
3950
3951
3952 /* Dirty? Well, I still did not learn better way to account
3953  * for user mmaps.
3954  */
3955
3956 static void packet_mm_open(struct vm_area_struct *vma)
3957 {
3958         struct file *file = vma->vm_file;
3959         struct socket *sock = file->private_data;
3960         struct sock *sk = sock->sk;
3961
3962         if (sk)
3963                 atomic_inc(&pkt_sk(sk)->mapped);
3964 }
3965
3966 static void packet_mm_close(struct vm_area_struct *vma)
3967 {
3968         struct file *file = vma->vm_file;
3969         struct socket *sock = file->private_data;
3970         struct sock *sk = sock->sk;
3971
3972         if (sk)
3973                 atomic_dec(&pkt_sk(sk)->mapped);
3974 }
3975
3976 static const struct vm_operations_struct packet_mmap_ops = {
3977         .open   =       packet_mm_open,
3978         .close  =       packet_mm_close,
3979 };
3980
3981 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3982                         unsigned int len)
3983 {
3984         int i;
3985
3986         for (i = 0; i < len; i++) {
3987                 if (likely(pg_vec[i].buffer)) {
3988                         if (is_vmalloc_addr(pg_vec[i].buffer))
3989                                 vfree(pg_vec[i].buffer);
3990                         else
3991                                 free_pages((unsigned long)pg_vec[i].buffer,
3992                                            order);
3993                         pg_vec[i].buffer = NULL;
3994                 }
3995         }
3996         kfree(pg_vec);
3997 }
3998
3999 static char *alloc_one_pg_vec_page(unsigned long order)
4000 {
4001         char *buffer;
4002         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
4003                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
4004
4005         buffer = (char *) __get_free_pages(gfp_flags, order);
4006         if (buffer)
4007                 return buffer;
4008
4009         /* __get_free_pages failed, fall back to vmalloc */
4010         buffer = vzalloc((1 << order) * PAGE_SIZE);
4011         if (buffer)
4012                 return buffer;
4013
4014         /* vmalloc failed, lets dig into swap here */
4015         gfp_flags &= ~__GFP_NORETRY;
4016         buffer = (char *) __get_free_pages(gfp_flags, order);
4017         if (buffer)
4018                 return buffer;
4019
4020         /* complete and utter failure */
4021         return NULL;
4022 }
4023
4024 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
4025 {
4026         unsigned int block_nr = req->tp_block_nr;
4027         struct pgv *pg_vec;
4028         int i;
4029
4030         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
4031         if (unlikely(!pg_vec))
4032                 goto out;
4033
4034         for (i = 0; i < block_nr; i++) {
4035                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
4036                 if (unlikely(!pg_vec[i].buffer))
4037                         goto out_free_pgvec;
4038         }
4039
4040 out:
4041         return pg_vec;
4042
4043 out_free_pgvec:
4044         free_pg_vec(pg_vec, order, block_nr);
4045         pg_vec = NULL;
4046         goto out;
4047 }
4048
4049 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
4050                 int closing, int tx_ring)
4051 {
4052         struct pgv *pg_vec = NULL;
4053         struct packet_sock *po = pkt_sk(sk);
4054         int was_running, order = 0;
4055         struct packet_ring_buffer *rb;
4056         struct sk_buff_head *rb_queue;
4057         __be16 num;
4058         int err = -EINVAL;
4059         /* Added to avoid minimal code churn */
4060         struct tpacket_req *req = &req_u->req;
4061
4062         /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
4063         if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
4064                 WARN(1, "Tx-ring is not supported.\n");
4065                 goto out;
4066         }
4067
4068         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
4069         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
4070
4071         err = -EBUSY;
4072         if (!closing) {
4073                 if (atomic_read(&po->mapped))
4074                         goto out;
4075                 if (packet_read_pending(rb))
4076                         goto out;
4077         }
4078
4079         if (req->tp_block_nr) {
4080                 /* Sanity tests and some calculations */
4081                 err = -EBUSY;
4082                 if (unlikely(rb->pg_vec))
4083                         goto out;
4084
4085                 switch (po->tp_version) {
4086                 case TPACKET_V1:
4087                         po->tp_hdrlen = TPACKET_HDRLEN;
4088                         break;
4089                 case TPACKET_V2:
4090                         po->tp_hdrlen = TPACKET2_HDRLEN;
4091                         break;
4092                 case TPACKET_V3:
4093                         po->tp_hdrlen = TPACKET3_HDRLEN;
4094                         break;
4095                 }
4096
4097                 err = -EINVAL;
4098                 if (unlikely((int)req->tp_block_size <= 0))
4099                         goto out;
4100                 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
4101                         goto out;
4102                 if (po->tp_version >= TPACKET_V3 &&
4103                     (int)(req->tp_block_size -
4104                           BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
4105                         goto out;
4106                 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
4107                                         po->tp_reserve))
4108                         goto out;
4109                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
4110                         goto out;
4111
4112                 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
4113                 if (unlikely(rb->frames_per_block <= 0))
4114                         goto out;
4115                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
4116                                         req->tp_frame_nr))
4117                         goto out;
4118
4119                 err = -ENOMEM;
4120                 order = get_order(req->tp_block_size);
4121                 pg_vec = alloc_pg_vec(req, order);
4122                 if (unlikely(!pg_vec))
4123                         goto out;
4124                 switch (po->tp_version) {
4125                 case TPACKET_V3:
4126                 /* Transmit path is not supported. We checked
4127                  * it above but just being paranoid
4128                  */
4129                         if (!tx_ring)
4130                                 init_prb_bdqc(po, rb, pg_vec, req_u);
4131                         break;
4132                 default:
4133                         break;
4134                 }
4135         }
4136         /* Done */
4137         else {
4138                 err = -EINVAL;
4139                 if (unlikely(req->tp_frame_nr))
4140                         goto out;
4141         }
4142
4143         lock_sock(sk);
4144
4145         /* Detach socket from network */
4146         spin_lock(&po->bind_lock);
4147         was_running = po->running;
4148         num = po->num;
4149         if (was_running) {
4150                 po->num = 0;
4151                 __unregister_prot_hook(sk, false);
4152         }
4153         spin_unlock(&po->bind_lock);
4154
4155         synchronize_net();
4156
4157         err = -EBUSY;
4158         mutex_lock(&po->pg_vec_lock);
4159         if (closing || atomic_read(&po->mapped) == 0) {
4160                 err = 0;
4161                 spin_lock_bh(&rb_queue->lock);
4162                 swap(rb->pg_vec, pg_vec);
4163                 rb->frame_max = (req->tp_frame_nr - 1);
4164                 rb->head = 0;
4165                 rb->frame_size = req->tp_frame_size;
4166                 spin_unlock_bh(&rb_queue->lock);
4167
4168                 swap(rb->pg_vec_order, order);
4169                 swap(rb->pg_vec_len, req->tp_block_nr);
4170
4171                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4172                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4173                                                 tpacket_rcv : packet_rcv;
4174                 skb_queue_purge(rb_queue);
4175                 if (atomic_read(&po->mapped))
4176                         pr_err("packet_mmap: vma is busy: %d\n",
4177                                atomic_read(&po->mapped));
4178         }
4179         mutex_unlock(&po->pg_vec_lock);
4180
4181         spin_lock(&po->bind_lock);
4182         if (was_running) {
4183                 po->num = num;
4184                 register_prot_hook(sk);
4185         }
4186         spin_unlock(&po->bind_lock);
4187         if (closing && (po->tp_version > TPACKET_V2)) {
4188                 /* Because we don't support block-based V3 on tx-ring */
4189                 if (!tx_ring)
4190                         prb_shutdown_retire_blk_timer(po, rb_queue);
4191         }
4192         release_sock(sk);
4193
4194         if (pg_vec)
4195                 free_pg_vec(pg_vec, order, req->tp_block_nr);
4196 out:
4197         return err;
4198 }
4199
4200 static int packet_mmap(struct file *file, struct socket *sock,
4201                 struct vm_area_struct *vma)
4202 {
4203         struct sock *sk = sock->sk;
4204         struct packet_sock *po = pkt_sk(sk);
4205         unsigned long size, expected_size;
4206         struct packet_ring_buffer *rb;
4207         unsigned long start;
4208         int err = -EINVAL;
4209         int i;
4210
4211         if (vma->vm_pgoff)
4212                 return -EINVAL;
4213
4214         mutex_lock(&po->pg_vec_lock);
4215
4216         expected_size = 0;
4217         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4218                 if (rb->pg_vec) {
4219                         expected_size += rb->pg_vec_len
4220                                                 * rb->pg_vec_pages
4221                                                 * PAGE_SIZE;
4222                 }
4223         }
4224
4225         if (expected_size == 0)
4226                 goto out;
4227
4228         size = vma->vm_end - vma->vm_start;
4229         if (size != expected_size)
4230                 goto out;
4231
4232         start = vma->vm_start;
4233         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4234                 if (rb->pg_vec == NULL)
4235                         continue;
4236
4237                 for (i = 0; i < rb->pg_vec_len; i++) {
4238                         struct page *page;
4239                         void *kaddr = rb->pg_vec[i].buffer;
4240                         int pg_num;
4241
4242                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4243                                 page = pgv_to_page(kaddr);
4244                                 err = vm_insert_page(vma, start, page);
4245                                 if (unlikely(err))
4246                                         goto out;
4247                                 start += PAGE_SIZE;
4248                                 kaddr += PAGE_SIZE;
4249                         }
4250                 }
4251         }
4252
4253         atomic_inc(&po->mapped);
4254         vma->vm_ops = &packet_mmap_ops;
4255         err = 0;
4256
4257 out:
4258         mutex_unlock(&po->pg_vec_lock);
4259         return err;
4260 }
4261
4262 static const struct proto_ops packet_ops_spkt = {
4263         .family =       PF_PACKET,
4264         .owner =        THIS_MODULE,
4265         .release =      packet_release,
4266         .bind =         packet_bind_spkt,
4267         .connect =      sock_no_connect,
4268         .socketpair =   sock_no_socketpair,
4269         .accept =       sock_no_accept,
4270         .getname =      packet_getname_spkt,
4271         .poll =         datagram_poll,
4272         .ioctl =        packet_ioctl,
4273         .listen =       sock_no_listen,
4274         .shutdown =     sock_no_shutdown,
4275         .setsockopt =   sock_no_setsockopt,
4276         .getsockopt =   sock_no_getsockopt,
4277         .sendmsg =      packet_sendmsg_spkt,
4278         .recvmsg =      packet_recvmsg,
4279         .mmap =         sock_no_mmap,
4280         .sendpage =     sock_no_sendpage,
4281 };
4282
4283 static const struct proto_ops packet_ops = {
4284         .family =       PF_PACKET,
4285         .owner =        THIS_MODULE,
4286         .release =      packet_release,
4287         .bind =         packet_bind,
4288         .connect =      sock_no_connect,
4289         .socketpair =   sock_no_socketpair,
4290         .accept =       sock_no_accept,
4291         .getname =      packet_getname,
4292         .poll =         packet_poll,
4293         .ioctl =        packet_ioctl,
4294         .listen =       sock_no_listen,
4295         .shutdown =     sock_no_shutdown,
4296         .setsockopt =   packet_setsockopt,
4297         .getsockopt =   packet_getsockopt,
4298         .sendmsg =      packet_sendmsg,
4299         .recvmsg =      packet_recvmsg,
4300         .mmap =         packet_mmap,
4301         .sendpage =     sock_no_sendpage,
4302 };
4303
4304 static const struct net_proto_family packet_family_ops = {
4305         .family =       PF_PACKET,
4306         .create =       packet_create,
4307         .owner  =       THIS_MODULE,
4308 };
4309
4310 static struct notifier_block packet_netdev_notifier = {
4311         .notifier_call =        packet_notifier,
4312 };
4313
4314 #ifdef CONFIG_PROC_FS
4315
4316 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4317         __acquires(RCU)
4318 {
4319         struct net *net = seq_file_net(seq);
4320
4321         rcu_read_lock();
4322         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4323 }
4324
4325 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4326 {
4327         struct net *net = seq_file_net(seq);
4328         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4329 }
4330
4331 static void packet_seq_stop(struct seq_file *seq, void *v)
4332         __releases(RCU)
4333 {
4334         rcu_read_unlock();
4335 }
4336
4337 static int packet_seq_show(struct seq_file *seq, void *v)
4338 {
4339         if (v == SEQ_START_TOKEN)
4340                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
4341         else {
4342                 struct sock *s = sk_entry(v);
4343                 const struct packet_sock *po = pkt_sk(s);
4344
4345                 seq_printf(seq,
4346                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
4347                            s,
4348                            atomic_read(&s->sk_refcnt),
4349                            s->sk_type,
4350                            ntohs(po->num),
4351                            po->ifindex,
4352                            po->running,
4353                            atomic_read(&s->sk_rmem_alloc),
4354                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4355                            sock_i_ino(s));
4356         }
4357
4358         return 0;
4359 }
4360
4361 static const struct seq_operations packet_seq_ops = {
4362         .start  = packet_seq_start,
4363         .next   = packet_seq_next,
4364         .stop   = packet_seq_stop,
4365         .show   = packet_seq_show,
4366 };
4367
4368 static int packet_seq_open(struct inode *inode, struct file *file)
4369 {
4370         return seq_open_net(inode, file, &packet_seq_ops,
4371                             sizeof(struct seq_net_private));
4372 }
4373
4374 static const struct file_operations packet_seq_fops = {
4375         .owner          = THIS_MODULE,
4376         .open           = packet_seq_open,
4377         .read           = seq_read,
4378         .llseek         = seq_lseek,
4379         .release        = seq_release_net,
4380 };
4381
4382 #endif
4383
4384 static int __net_init packet_net_init(struct net *net)
4385 {
4386         mutex_init(&net->packet.sklist_lock);
4387         INIT_HLIST_HEAD(&net->packet.sklist);
4388
4389         if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4390                 return -ENOMEM;
4391
4392         return 0;
4393 }
4394
4395 static void __net_exit packet_net_exit(struct net *net)
4396 {
4397         remove_proc_entry("packet", net->proc_net);
4398 }
4399
4400 static struct pernet_operations packet_net_ops = {
4401         .init = packet_net_init,
4402         .exit = packet_net_exit,
4403 };
4404
4405
4406 static void __exit packet_exit(void)
4407 {
4408         unregister_netdevice_notifier(&packet_netdev_notifier);
4409         unregister_pernet_subsys(&packet_net_ops);
4410         sock_unregister(PF_PACKET);
4411         proto_unregister(&packet_proto);
4412 }
4413
4414 static int __init packet_init(void)
4415 {
4416         int rc = proto_register(&packet_proto, 0);
4417
4418         if (rc != 0)
4419                 goto out;
4420
4421         sock_register(&packet_family_ops);
4422         register_pernet_subsys(&packet_net_ops);
4423         register_netdevice_notifier(&packet_netdev_notifier);
4424 out:
4425         return rc;
4426 }
4427
4428 module_init(packet_init);
4429 module_exit(packet_exit);
4430 MODULE_LICENSE("GPL");
4431 MODULE_ALIAS_NETPROTO(PF_PACKET);