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
  96 #include "internal.h"
  97
  98 /*
  99    Assumptions:
 100    - if device has no dev->hard_header routine, it adds and removes ll header
 101      inside itself. In this case ll header is invisible outside of device,
 102      but higher levels still should reserve dev->hard_header_len.
 103      Some devices are enough clever to reallocate skb, when header
 104      will not fit to reserved space (tunnel), another ones are silly
 105      (PPP).
 106    - packet socket receives packets with pulled ll header,
 107      so that SOCK_RAW should push it back.
 108
 109 On receive:
 110 -----------
 111
 112 Incoming, dev->hard_header!=NULL
 113    mac_header -> ll header
 114    data       -> data
 115
 116 Outgoing, dev->hard_header!=NULL
 117    mac_header -> ll header
 118    data       -> ll header
 119
 120 Incoming, dev->hard_header==NULL
 121    mac_header -> UNKNOWN position. It is very likely, that it points to ll
 122                  header.  PPP makes it, that is wrong, because introduce
 123                  assymetry between rx and tx paths.
 124    data       -> data
 125
 126 Outgoing, dev->hard_header==NULL
 127    mac_header -> data. ll header is still not built!
 128    data       -> data
 129
 130 Resume
 131   If dev->hard_header==NULL we are unlikely to restore sensible ll header.
 132
 133
 134 On transmit:
 135 ------------
 136
 137 dev->hard_header != NULL
 138    mac_header -> ll header
 139    data       -> ll header
 140
 141 dev->hard_header == NULL (ll header is added by device, we cannot control it)
 142    mac_header -> data
 143    data       -> data
 144
 145    We should set nh.raw on output to correct posistion,
 146    packet classifier depends on it.
 147  */
 148
 149 /* Private packet socket structures. */
 150
 151 /* identical to struct packet_mreq except it has
 152  * a longer address field.
 153  */
 154 struct packet_mreq_max {
 155         int             mr_ifindex;
 156         unsigned short  mr_type;
 157         unsigned short  mr_alen;
 158         unsigned char   mr_address[MAX_ADDR_LEN];
 159 };
 160
 161 union tpacket_uhdr {
 162         struct tpacket_hdr  *h1;
 163         struct tpacket2_hdr *h2;
 164         struct tpacket3_hdr *h3;
 165         void *raw;
 166 };
 167
 168 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 169                 int closing, int tx_ring);
 170
 171 #define V3_ALIGNMENT    (8)
 172
 173 #define BLK_HDR_LEN     (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
 174
 175 #define BLK_PLUS_PRIV(sz_of_priv) \
 176         (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
 177
 178 #define PGV_FROM_VMALLOC 1
 179
 180 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
 181 #define BLOCK_NUM_PKTS(x)       ((x)->hdr.bh1.num_pkts)
 182 #define BLOCK_O2FP(x)           ((x)->hdr.bh1.offset_to_first_pkt)
 183 #define BLOCK_LEN(x)            ((x)->hdr.bh1.blk_len)
 184 #define BLOCK_SNUM(x)           ((x)->hdr.bh1.seq_num)
 185 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
 186 #define BLOCK_PRIV(x)           ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
 187
 188 struct packet_sock;
 189 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
 190 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
 191                        struct packet_type *pt, struct net_device *orig_dev);
 192
 193 static void *packet_previous_frame(struct packet_sock *po,
 194                 struct packet_ring_buffer *rb,
 195                 int status);
 196 static void packet_increment_head(struct packet_ring_buffer *buff);
 197 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
 198                         struct tpacket_block_desc *);
 199 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
 200                         struct packet_sock *);
 201 static void prb_retire_current_block(struct tpacket_kbdq_core *,
 202                 struct packet_sock *, unsigned int status);
 203 static int prb_queue_frozen(struct tpacket_kbdq_core *);
 204 static void prb_open_block(struct tpacket_kbdq_core *,
 205                 struct tpacket_block_desc *);
 206 static void prb_retire_rx_blk_timer_expired(unsigned long);
 207 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
 208 static void prb_init_blk_timer(struct packet_sock *,
 209                 struct tpacket_kbdq_core *,
 210                 void (*func) (unsigned long));
 211 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
 212 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
 213                 struct tpacket3_hdr *);
 214 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
 215                 struct tpacket3_hdr *);
 216 static void packet_flush_mclist(struct sock *sk);
 217
 218 struct packet_skb_cb {
 219         union {
 220                 struct sockaddr_pkt pkt;
 221                 union {
 222                         /* Trick: alias skb original length with
 223                          * ll.sll_family and ll.protocol in order
 224                          * to save room.
 225                          */
 226                         unsigned int origlen;
 227                         struct sockaddr_ll ll;
 228                 };
 229         } sa;
 230 };
 231
 232 #define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
 233
 234 #define GET_PBDQC_FROM_RB(x)    ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
 235 #define GET_PBLOCK_DESC(x, bid) \
 236         ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
 237 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x)       \
 238         ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
 239 #define GET_NEXT_PRB_BLK_NUM(x) \
 240         (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
 241         ((x)->kactive_blk_num+1) : 0)
 242
 243 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
 244 static void __fanout_link(struct sock *sk, struct packet_sock *po);
 245
 246 static int packet_direct_xmit(struct sk_buff *skb)
 247 {
 248         struct net_device *dev = skb->dev;
 249         netdev_features_t features;
 250         struct netdev_queue *txq;
 251         int ret = NETDEV_TX_BUSY;
 252
 253         if (unlikely(!netif_running(dev) ||
 254                      !netif_carrier_ok(dev)))
 255                 goto drop;
 256
 257         features = netif_skb_features(skb);
 258         if (skb_needs_linearize(skb, features) &&
 259             __skb_linearize(skb))
 260                 goto drop;
 261
 262         txq = skb_get_tx_queue(dev, skb);
 263
 264         local_bh_disable();
 265
 266         HARD_TX_LOCK(dev, txq, smp_processor_id());
 267         if (!netif_xmit_frozen_or_drv_stopped(txq))
 268                 ret = netdev_start_xmit(skb, dev, txq, false);
 269         HARD_TX_UNLOCK(dev, txq);
 270
 271         local_bh_enable();
 272
 273         if (!dev_xmit_complete(ret))
 274                 kfree_skb(skb);
 275
 276         return ret;
 277 drop:
 278         atomic_long_inc(&dev->tx_dropped);
 279         kfree_skb(skb);
 280         return NET_XMIT_DROP;
 281 }
 282
 283 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
 284 {
 285         struct net_device *dev;
 286
 287         rcu_read_lock();
 288         dev = rcu_dereference(po->cached_dev);
 289         if (likely(dev))
 290                 dev_hold(dev);
 291         rcu_read_unlock();
 292
 293         return dev;
 294 }
 295
 296 static void packet_cached_dev_assign(struct packet_sock *po,
 297                                      struct net_device *dev)
 298 {
 299         rcu_assign_pointer(po->cached_dev, dev);
 300 }
 301
 302 static void packet_cached_dev_reset(struct packet_sock *po)
 303 {
 304         RCU_INIT_POINTER(po->cached_dev, NULL);
 305 }
 306
 307 static bool packet_use_direct_xmit(const struct packet_sock *po)
 308 {
 309         return po->xmit == packet_direct_xmit;
 310 }
 311
 312 static u16 __packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
 313 {
 314         return (u16) raw_smp_processor_id() % dev->real_num_tx_queues;
 315 }
 316
 317 static void packet_pick_tx_queue(struct net_device *dev, struct sk_buff *skb)
 318 {
 319         const struct net_device_ops *ops = dev->netdev_ops;
 320         u16 queue_index;
 321
 322         if (ops->ndo_select_queue) {
 323                 queue_index = ops->ndo_select_queue(dev, skb, NULL,
 324                                                     __packet_pick_tx_queue);
 325                 queue_index = netdev_cap_txqueue(dev, queue_index);
 326         } else {
 327                 queue_index = __packet_pick_tx_queue(dev, skb);
 328         }
 329
 330         skb_set_queue_mapping(skb, queue_index);
 331 }
 332
 333 /* register_prot_hook must be invoked with the po->bind_lock held,
 334  * or from a context in which asynchronous accesses to the packet
 335  * socket is not possible (packet_create()).
 336  */
 337 static void register_prot_hook(struct sock *sk)
 338 {
 339         struct packet_sock *po = pkt_sk(sk);
 340
 341         if (!po->running) {
 342                 if (po->fanout)
 343                         __fanout_link(sk, po);
 344                 else
 345                         dev_add_pack(&po->prot_hook);
 346
 347                 sock_hold(sk);
 348                 po->running = 1;
 349         }
 350 }
 351
 352 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
 353  * held.   If the sync parameter is true, we will temporarily drop
 354  * the po->bind_lock and do a synchronize_net to make sure no
 355  * asynchronous packet processing paths still refer to the elements
 356  * of po->prot_hook.  If the sync parameter is false, it is the
 357  * callers responsibility to take care of this.
 358  */
 359 static void __unregister_prot_hook(struct sock *sk, bool sync)
 360 {
 361         struct packet_sock *po = pkt_sk(sk);
 362
 363         po->running = 0;
 364
 365         if (po->fanout)
 366                 __fanout_unlink(sk, po);
 367         else
 368                 __dev_remove_pack(&po->prot_hook);
 369
 370         __sock_put(sk);
 371
 372         if (sync) {
 373                 spin_unlock(&po->bind_lock);
 374                 synchronize_net();
 375                 spin_lock(&po->bind_lock);
 376         }
 377 }
 378
 379 static void unregister_prot_hook(struct sock *sk, bool sync)
 380 {
 381         struct packet_sock *po = pkt_sk(sk);
 382
 383         if (po->running)
 384                 __unregister_prot_hook(sk, sync);
 385 }
 386
 387 static inline struct page * __pure pgv_to_page(void *addr)
 388 {
 389         if (is_vmalloc_addr(addr))
 390                 return vmalloc_to_page(addr);
 391         return virt_to_page(addr);
 392 }
 393
 394 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
 395 {
 396         union tpacket_uhdr h;
 397
 398         h.raw = frame;
 399         switch (po->tp_version) {
 400         case TPACKET_V1:
 401                 h.h1->tp_status = status;
 402                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 403                 break;
 404         case TPACKET_V2:
 405                 h.h2->tp_status = status;
 406                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 407                 break;
 408         case TPACKET_V3:
 409         default:
 410                 WARN(1, "TPACKET version not supported.\n");
 411                 BUG();
 412         }
 413
 414         smp_wmb();
 415 }
 416
 417 static int __packet_get_status(struct packet_sock *po, void *frame)
 418 {
 419         union tpacket_uhdr h;
 420
 421         smp_rmb();
 422
 423         h.raw = frame;
 424         switch (po->tp_version) {
 425         case TPACKET_V1:
 426                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 427                 return h.h1->tp_status;
 428         case TPACKET_V2:
 429                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 430                 return h.h2->tp_status;
 431         case TPACKET_V3:
 432         default:
 433                 WARN(1, "TPACKET version not supported.\n");
 434                 BUG();
 435                 return 0;
 436         }
 437 }
 438
 439 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
 440                                    unsigned int flags)
 441 {
 442         struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
 443
 444         if (shhwtstamps &&
 445             (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
 446             ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
 447                 return TP_STATUS_TS_RAW_HARDWARE;
 448
 449         if (ktime_to_timespec_cond(skb->tstamp, ts))
 450                 return TP_STATUS_TS_SOFTWARE;
 451
 452         return 0;
 453 }
 454
 455 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
 456                                     struct sk_buff *skb)
 457 {
 458         union tpacket_uhdr h;
 459         struct timespec ts;
 460         __u32 ts_status;
 461
 462         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
 463                 return 0;
 464
 465         h.raw = frame;
 466         switch (po->tp_version) {
 467         case TPACKET_V1:
 468                 h.h1->tp_sec = ts.tv_sec;
 469                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
 470                 break;
 471         case TPACKET_V2:
 472                 h.h2->tp_sec = ts.tv_sec;
 473                 h.h2->tp_nsec = ts.tv_nsec;
 474                 break;
 475         case TPACKET_V3:
 476         default:
 477                 WARN(1, "TPACKET version not supported.\n");
 478                 BUG();
 479         }
 480
 481         /* one flush is safe, as both fields always lie on the same cacheline */
 482         flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
 483         smp_wmb();
 484
 485         return ts_status;
 486 }
 487
 488 static void *packet_lookup_frame(struct packet_sock *po,
 489                 struct packet_ring_buffer *rb,
 490                 unsigned int position,
 491                 int status)
 492 {
 493         unsigned int pg_vec_pos, frame_offset;
 494         union tpacket_uhdr h;
 495
 496         pg_vec_pos = position / rb->frames_per_block;
 497         frame_offset = position % rb->frames_per_block;
 498
 499         h.raw = rb->pg_vec[pg_vec_pos].buffer +
 500                 (frame_offset * rb->frame_size);
 501
 502         if (status != __packet_get_status(po, h.raw))
 503                 return NULL;
 504
 505         return h.raw;
 506 }
 507
 508 static void *packet_current_frame(struct packet_sock *po,
 509                 struct packet_ring_buffer *rb,
 510                 int status)
 511 {
 512         return packet_lookup_frame(po, rb, rb->head, status);
 513 }
 514
 515 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 516 {
 517         del_timer_sync(&pkc->retire_blk_timer);
 518 }
 519
 520 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
 521                 int tx_ring,
 522                 struct sk_buff_head *rb_queue)
 523 {
 524         struct tpacket_kbdq_core *pkc;
 525
 526         pkc = tx_ring ? GET_PBDQC_FROM_RB(&po->tx_ring) :
 527                         GET_PBDQC_FROM_RB(&po->rx_ring);
 528
 529         spin_lock_bh(&rb_queue->lock);
 530         pkc->delete_blk_timer = 1;
 531         spin_unlock_bh(&rb_queue->lock);
 532
 533         prb_del_retire_blk_timer(pkc);
 534 }
 535
 536 static void prb_init_blk_timer(struct packet_sock *po,
 537                 struct tpacket_kbdq_core *pkc,
 538                 void (*func) (unsigned long))
 539 {
 540         init_timer(&pkc->retire_blk_timer);
 541         pkc->retire_blk_timer.data = (long)po;
 542         pkc->retire_blk_timer.function = func;
 543         pkc->retire_blk_timer.expires = jiffies;
 544 }
 545
 546 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
 547 {
 548         struct tpacket_kbdq_core *pkc;
 549
 550         if (tx_ring)
 551                 BUG();
 552
 553         pkc = tx_ring ? GET_PBDQC_FROM_RB(&po->tx_ring) :
 554                         GET_PBDQC_FROM_RB(&po->rx_ring);
 555         prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
 556 }
 557
 558 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
 559                                 int blk_size_in_bytes)
 560 {
 561         struct net_device *dev;
 562         unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
 563         struct ethtool_cmd ecmd;
 564         int err;
 565         u32 speed;
 566
 567         rtnl_lock();
 568         dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
 569         if (unlikely(!dev)) {
 570                 rtnl_unlock();
 571                 return DEFAULT_PRB_RETIRE_TOV;
 572         }
 573         err = __ethtool_get_settings(dev, &ecmd);
 574         speed = ethtool_cmd_speed(&ecmd);
 575         rtnl_unlock();
 576         if (!err) {
 577                 /*
 578                  * If the link speed is so slow you don't really
 579                  * need to worry about perf anyways
 580                  */
 581                 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
 582                         return DEFAULT_PRB_RETIRE_TOV;
 583                 } else {
 584                         msec = 1;
 585                         div = speed / 1000;
 586                 }
 587         }
 588
 589         mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
 590
 591         if (div)
 592                 mbits /= div;
 593
 594         tmo = mbits * msec;
 595
 596         if (div)
 597                 return tmo+1;
 598         return tmo;
 599 }
 600
 601 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
 602                         union tpacket_req_u *req_u)
 603 {
 604         p1->feature_req_word = req_u->req3.tp_feature_req_word;
 605 }
 606
 607 static void init_prb_bdqc(struct packet_sock *po,
 608                         struct packet_ring_buffer *rb,
 609                         struct pgv *pg_vec,
 610                         union tpacket_req_u *req_u, int tx_ring)
 611 {
 612         struct tpacket_kbdq_core *p1 = GET_PBDQC_FROM_RB(rb);
 613         struct tpacket_block_desc *pbd;
 614
 615         memset(p1, 0x0, sizeof(*p1));
 616
 617         p1->knxt_seq_num = 1;
 618         p1->pkbdq = pg_vec;
 619         pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
 620         p1->pkblk_start = pg_vec[0].buffer;
 621         p1->kblk_size = req_u->req3.tp_block_size;
 622         p1->knum_blocks = req_u->req3.tp_block_nr;
 623         p1->hdrlen = po->tp_hdrlen;
 624         p1->version = po->tp_version;
 625         p1->last_kactive_blk_num = 0;
 626         po->stats.stats3.tp_freeze_q_cnt = 0;
 627         if (req_u->req3.tp_retire_blk_tov)
 628                 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
 629         else
 630                 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
 631                                                 req_u->req3.tp_block_size);
 632         p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
 633         p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
 634
 635         p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
 636         prb_init_ft_ops(p1, req_u);
 637         prb_setup_retire_blk_timer(po, tx_ring);
 638         prb_open_block(p1, pbd);
 639 }
 640
 641 /*  Do NOT update the last_blk_num first.
 642  *  Assumes sk_buff_head lock is held.
 643  */
 644 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 645 {
 646         mod_timer(&pkc->retire_blk_timer,
 647                         jiffies + pkc->tov_in_jiffies);
 648         pkc->last_kactive_blk_num = pkc->kactive_blk_num;
 649 }
 650
 651 /*
 652  * Timer logic:
 653  * 1) We refresh the timer only when we open a block.
 654  *    By doing this we don't waste cycles refreshing the timer
 655  *        on packet-by-packet basis.
 656  *
 657  * With a 1MB block-size, on a 1Gbps line, it will take
 658  * i) ~8 ms to fill a block + ii) memcpy etc.
 659  * In this cut we are not accounting for the memcpy time.
 660  *
 661  * So, if the user sets the 'tmo' to 10ms then the timer
 662  * will never fire while the block is still getting filled
 663  * (which is what we want). However, the user could choose
 664  * to close a block early and that's fine.
 665  *
 666  * But when the timer does fire, we check whether or not to refresh it.
 667  * Since the tmo granularity is in msecs, it is not too expensive
 668  * to refresh the timer, lets say every '8' msecs.
 669  * Either the user can set the 'tmo' or we can derive it based on
 670  * a) line-speed and b) block-size.
 671  * prb_calc_retire_blk_tmo() calculates the tmo.
 672  *
 673  */
 674 static void prb_retire_rx_blk_timer_expired(unsigned long data)
 675 {
 676         struct packet_sock *po = (struct packet_sock *)data;
 677         struct tpacket_kbdq_core *pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 678         unsigned int frozen;
 679         struct tpacket_block_desc *pbd;
 680
 681         spin_lock(&po->sk.sk_receive_queue.lock);
 682
 683         frozen = prb_queue_frozen(pkc);
 684         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 685
 686         if (unlikely(pkc->delete_blk_timer))
 687                 goto out;
 688
 689         /* We only need to plug the race when the block is partially filled.
 690          * tpacket_rcv:
 691          *              lock(); increment BLOCK_NUM_PKTS; unlock()
 692          *              copy_bits() is in progress ...
 693          *              timer fires on other cpu:
 694          *              we can't retire the current block because copy_bits
 695          *              is in progress.
 696          *
 697          */
 698         if (BLOCK_NUM_PKTS(pbd)) {
 699                 while (atomic_read(&pkc->blk_fill_in_prog)) {
 700                         /* Waiting for skb_copy_bits to finish... */
 701                         cpu_relax();
 702                 }
 703         }
 704
 705         if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
 706                 if (!frozen) {
 707                         if (!BLOCK_NUM_PKTS(pbd)) {
 708                                 /* An empty block. Just refresh the timer. */
 709                                 goto refresh_timer;
 710                         }
 711                         prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
 712                         if (!prb_dispatch_next_block(pkc, po))
 713                                 goto refresh_timer;
 714                         else
 715                                 goto out;
 716                 } else {
 717                         /* Case 1. Queue was frozen because user-space was
 718                          *         lagging behind.
 719                          */
 720                         if (prb_curr_blk_in_use(pkc, pbd)) {
 721                                 /*
 722                                  * Ok, user-space is still behind.
 723                                  * So just refresh the timer.
 724                                  */
 725                                 goto refresh_timer;
 726                         } else {
 727                                /* Case 2. queue was frozen,user-space caught up,
 728                                 * now the link went idle && the timer fired.
 729                                 * We don't have a block to close.So we open this
 730                                 * block and restart the timer.
 731                                 * opening a block thaws the queue,restarts timer
 732                                 * Thawing/timer-refresh is a side effect.
 733                                 */
 734                                 prb_open_block(pkc, pbd);
 735                                 goto out;
 736                         }
 737                 }
 738         }
 739
 740 refresh_timer:
 741         _prb_refresh_rx_retire_blk_timer(pkc);
 742
 743 out:
 744         spin_unlock(&po->sk.sk_receive_queue.lock);
 745 }
 746
 747 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
 748                 struct tpacket_block_desc *pbd1, __u32 status)
 749 {
 750         /* Flush everything minus the block header */
 751
 752 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 753         u8 *start, *end;
 754
 755         start = (u8 *)pbd1;
 756
 757         /* Skip the block header(we know header WILL fit in 4K) */
 758         start += PAGE_SIZE;
 759
 760         end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
 761         for (; start < end; start += PAGE_SIZE)
 762                 flush_dcache_page(pgv_to_page(start));
 763
 764         smp_wmb();
 765 #endif
 766
 767         /* Now update the block status. */
 768
 769         BLOCK_STATUS(pbd1) = status;
 770
 771         /* Flush the block header */
 772
 773 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 774         start = (u8 *)pbd1;
 775         flush_dcache_page(pgv_to_page(start));
 776
 777         smp_wmb();
 778 #endif
 779 }
 780
 781 /*
 782  * Side effect:
 783  *
 784  * 1) flush the block
 785  * 2) Increment active_blk_num
 786  *
 787  * Note:We DONT refresh the timer on purpose.
 788  *      Because almost always the next block will be opened.
 789  */
 790 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
 791                 struct tpacket_block_desc *pbd1,
 792                 struct packet_sock *po, unsigned int stat)
 793 {
 794         __u32 status = TP_STATUS_USER | stat;
 795
 796         struct tpacket3_hdr *last_pkt;
 797         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 798         struct sock *sk = &po->sk;
 799
 800         if (po->stats.stats3.tp_drops)
 801                 status |= TP_STATUS_LOSING;
 802
 803         last_pkt = (struct tpacket3_hdr *)pkc1->prev;
 804         last_pkt->tp_next_offset = 0;
 805
 806         /* Get the ts of the last pkt */
 807         if (BLOCK_NUM_PKTS(pbd1)) {
 808                 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
 809                 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
 810         } else {
 811                 /* Ok, we tmo'd - so get the current time.
 812                  *
 813                  * It shouldn't really happen as we don't close empty
 814                  * blocks. See prb_retire_rx_blk_timer_expired().
 815                  */
 816                 struct timespec ts;
 817                 getnstimeofday(&ts);
 818                 h1->ts_last_pkt.ts_sec = ts.tv_sec;
 819                 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
 820         }
 821
 822         smp_wmb();
 823
 824         /* Flush the block */
 825         prb_flush_block(pkc1, pbd1, status);
 826
 827         sk->sk_data_ready(sk);
 828
 829         pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
 830 }
 831
 832 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
 833 {
 834         pkc->reset_pending_on_curr_blk = 0;
 835 }
 836
 837 /*
 838  * Side effect of opening a block:
 839  *
 840  * 1) prb_queue is thawed.
 841  * 2) retire_blk_timer is refreshed.
 842  *
 843  */
 844 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
 845         struct tpacket_block_desc *pbd1)
 846 {
 847         struct timespec ts;
 848         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 849
 850         smp_rmb();
 851
 852         /* We could have just memset this but we will lose the
 853          * flexibility of making the priv area sticky
 854          */
 855
 856         BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
 857         BLOCK_NUM_PKTS(pbd1) = 0;
 858         BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 859
 860         getnstimeofday(&ts);
 861
 862         h1->ts_first_pkt.ts_sec = ts.tv_sec;
 863         h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
 864
 865         pkc1->pkblk_start = (char *)pbd1;
 866         pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 867
 868         BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 869         BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
 870
 871         pbd1->version = pkc1->version;
 872         pkc1->prev = pkc1->nxt_offset;
 873         pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
 874
 875         prb_thaw_queue(pkc1);
 876         _prb_refresh_rx_retire_blk_timer(pkc1);
 877
 878         smp_wmb();
 879 }
 880
 881 /*
 882  * Queue freeze logic:
 883  * 1) Assume tp_block_nr = 8 blocks.
 884  * 2) At time 't0', user opens Rx ring.
 885  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
 886  * 4) user-space is either sleeping or processing block '0'.
 887  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
 888  *    it will close block-7,loop around and try to fill block '0'.
 889  *    call-flow:
 890  *    __packet_lookup_frame_in_block
 891  *      prb_retire_current_block()
 892  *      prb_dispatch_next_block()
 893  *        |->(BLOCK_STATUS == USER) evaluates to true
 894  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
 895  * 6) Now there are two cases:
 896  *    6.1) Link goes idle right after the queue is frozen.
 897  *         But remember, the last open_block() refreshed the timer.
 898  *         When this timer expires,it will refresh itself so that we can
 899  *         re-open block-0 in near future.
 900  *    6.2) Link is busy and keeps on receiving packets. This is a simple
 901  *         case and __packet_lookup_frame_in_block will check if block-0
 902  *         is free and can now be re-used.
 903  */
 904 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
 905                                   struct packet_sock *po)
 906 {
 907         pkc->reset_pending_on_curr_blk = 1;
 908         po->stats.stats3.tp_freeze_q_cnt++;
 909 }
 910
 911 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
 912
 913 /*
 914  * If the next block is free then we will dispatch it
 915  * and return a good offset.
 916  * Else, we will freeze the queue.
 917  * So, caller must check the return value.
 918  */
 919 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
 920                 struct packet_sock *po)
 921 {
 922         struct tpacket_block_desc *pbd;
 923
 924         smp_rmb();
 925
 926         /* 1. Get current block num */
 927         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 928
 929         /* 2. If this block is currently in_use then freeze the queue */
 930         if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
 931                 prb_freeze_queue(pkc, po);
 932                 return NULL;
 933         }
 934
 935         /*
 936          * 3.
 937          * open this block and return the offset where the first packet
 938          * needs to get stored.
 939          */
 940         prb_open_block(pkc, pbd);
 941         return (void *)pkc->nxt_offset;
 942 }
 943
 944 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
 945                 struct packet_sock *po, unsigned int status)
 946 {
 947         struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 948
 949         /* retire/close the current block */
 950         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
 951                 /*
 952                  * Plug the case where copy_bits() is in progress on
 953                  * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
 954                  * have space to copy the pkt in the current block and
 955                  * called prb_retire_current_block()
 956                  *
 957                  * We don't need to worry about the TMO case because
 958                  * the timer-handler already handled this case.
 959                  */
 960                 if (!(status & TP_STATUS_BLK_TMO)) {
 961                         while (atomic_read(&pkc->blk_fill_in_prog)) {
 962                                 /* Waiting for skb_copy_bits to finish... */
 963                                 cpu_relax();
 964                         }
 965                 }
 966                 prb_close_block(pkc, pbd, po, status);
 967                 return;
 968         }
 969 }
 970
 971 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
 972                                       struct tpacket_block_desc *pbd)
 973 {
 974         return TP_STATUS_USER & BLOCK_STATUS(pbd);
 975 }
 976
 977 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
 978 {
 979         return pkc->reset_pending_on_curr_blk;
 980 }
 981
 982 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
 983 {
 984         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
 985         atomic_dec(&pkc->blk_fill_in_prog);
 986 }
 987
 988 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
 989                         struct tpacket3_hdr *ppd)
 990 {
 991         ppd->hv1.tp_rxhash = skb_get_hash(pkc->skb);
 992 }
 993
 994 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
 995                         struct tpacket3_hdr *ppd)
 996 {
 997         ppd->hv1.tp_rxhash = 0;
 998 }
 999
1000 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
1001                         struct tpacket3_hdr *ppd)
1002 {
1003         if (skb_vlan_tag_present(pkc->skb)) {
1004                 ppd->hv1.tp_vlan_tci = skb_vlan_tag_get(pkc->skb);
1005                 ppd->hv1.tp_vlan_tpid = ntohs(pkc->skb->vlan_proto);
1006                 ppd->tp_status = TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
1007         } else {
1008                 ppd->hv1.tp_vlan_tci = 0;
1009                 ppd->hv1.tp_vlan_tpid = 0;
1010                 ppd->tp_status = TP_STATUS_AVAILABLE;
1011         }
1012 }
1013
1014 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
1015                         struct tpacket3_hdr *ppd)
1016 {
1017         ppd->hv1.tp_padding = 0;
1018         prb_fill_vlan_info(pkc, ppd);
1019
1020         if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
1021                 prb_fill_rxhash(pkc, ppd);
1022         else
1023                 prb_clear_rxhash(pkc, ppd);
1024 }
1025
1026 static void prb_fill_curr_block(char *curr,
1027                                 struct tpacket_kbdq_core *pkc,
1028                                 struct tpacket_block_desc *pbd,
1029                                 unsigned int len)
1030 {
1031         struct tpacket3_hdr *ppd;
1032
1033         ppd  = (struct tpacket3_hdr *)curr;
1034         ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
1035         pkc->prev = curr;
1036         pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
1037         BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
1038         BLOCK_NUM_PKTS(pbd) += 1;
1039         atomic_inc(&pkc->blk_fill_in_prog);
1040         prb_run_all_ft_ops(pkc, ppd);
1041 }
1042
1043 /* Assumes caller has the sk->rx_queue.lock */
1044 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1045                                             struct sk_buff *skb,
1046                                                 int status,
1047                                             unsigned int len
1048                                             )
1049 {
1050         struct tpacket_kbdq_core *pkc;
1051         struct tpacket_block_desc *pbd;
1052         char *curr, *end;
1053
1054         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1055         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1056
1057         /* Queue is frozen when user space is lagging behind */
1058         if (prb_queue_frozen(pkc)) {
1059                 /*
1060                  * Check if that last block which caused the queue to freeze,
1061                  * is still in_use by user-space.
1062                  */
1063                 if (prb_curr_blk_in_use(pkc, pbd)) {
1064                         /* Can't record this packet */
1065                         return NULL;
1066                 } else {
1067                         /*
1068                          * Ok, the block was released by user-space.
1069                          * Now let's open that block.
1070                          * opening a block also thaws the queue.
1071                          * Thawing is a side effect.
1072                          */
1073                         prb_open_block(pkc, pbd);
1074                 }
1075         }
1076
1077         smp_mb();
1078         curr = pkc->nxt_offset;
1079         pkc->skb = skb;
1080         end = (char *)pbd + pkc->kblk_size;
1081
1082         /* first try the current block */
1083         if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1084                 prb_fill_curr_block(curr, pkc, pbd, len);
1085                 return (void *)curr;
1086         }
1087
1088         /* Ok, close the current block */
1089         prb_retire_current_block(pkc, po, 0);
1090
1091         /* Now, try to dispatch the next block */
1092         curr = (char *)prb_dispatch_next_block(pkc, po);
1093         if (curr) {
1094                 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1095                 prb_fill_curr_block(curr, pkc, pbd, len);
1096                 return (void *)curr;
1097         }
1098
1099         /*
1100          * No free blocks are available.user_space hasn't caught up yet.
1101          * Queue was just frozen and now this packet will get dropped.
1102          */
1103         return NULL;
1104 }
1105
1106 static void *packet_current_rx_frame(struct packet_sock *po,
1107                                             struct sk_buff *skb,
1108                                             int status, unsigned int len)
1109 {
1110         char *curr = NULL;
1111         switch (po->tp_version) {
1112         case TPACKET_V1:
1113         case TPACKET_V2:
1114                 curr = packet_lookup_frame(po, &po->rx_ring,
1115                                         po->rx_ring.head, status);
1116                 return curr;
1117         case TPACKET_V3:
1118                 return __packet_lookup_frame_in_block(po, skb, status, len);
1119         default:
1120                 WARN(1, "TPACKET version not supported\n");
1121                 BUG();
1122                 return NULL;
1123         }
1124 }
1125
1126 static void *prb_lookup_block(struct packet_sock *po,
1127                                      struct packet_ring_buffer *rb,
1128                                      unsigned int idx,
1129                                      int status)
1130 {
1131         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1132         struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1133
1134         if (status != BLOCK_STATUS(pbd))
1135                 return NULL;
1136         return pbd;
1137 }
1138
1139 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1140 {
1141         unsigned int prev;
1142         if (rb->prb_bdqc.kactive_blk_num)
1143                 prev = rb->prb_bdqc.kactive_blk_num-1;
1144         else
1145                 prev = rb->prb_bdqc.knum_blocks-1;
1146         return prev;
1147 }
1148
1149 /* Assumes caller has held the rx_queue.lock */
1150 static void *__prb_previous_block(struct packet_sock *po,
1151                                          struct packet_ring_buffer *rb,
1152                                          int status)
1153 {
1154         unsigned int previous = prb_previous_blk_num(rb);
1155         return prb_lookup_block(po, rb, previous, status);
1156 }
1157
1158 static void *packet_previous_rx_frame(struct packet_sock *po,
1159                                              struct packet_ring_buffer *rb,
1160                                              int status)
1161 {
1162         if (po->tp_version <= TPACKET_V2)
1163                 return packet_previous_frame(po, rb, status);
1164
1165         return __prb_previous_block(po, rb, status);
1166 }
1167
1168 static void packet_increment_rx_head(struct packet_sock *po,
1169                                             struct packet_ring_buffer *rb)
1170 {
1171         switch (po->tp_version) {
1172         case TPACKET_V1:
1173         case TPACKET_V2:
1174                 return packet_increment_head(rb);
1175         case TPACKET_V3:
1176         default:
1177                 WARN(1, "TPACKET version not supported.\n");
1178                 BUG();
1179                 return;
1180         }
1181 }
1182
1183 static void *packet_previous_frame(struct packet_sock *po,
1184                 struct packet_ring_buffer *rb,
1185                 int status)
1186 {
1187         unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1188         return packet_lookup_frame(po, rb, previous, status);
1189 }
1190
1191 static void packet_increment_head(struct packet_ring_buffer *buff)
1192 {
1193         buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1194 }
1195
1196 static void packet_inc_pending(struct packet_ring_buffer *rb)
1197 {
1198         this_cpu_inc(*rb->pending_refcnt);
1199 }
1200
1201 static void packet_dec_pending(struct packet_ring_buffer *rb)
1202 {
1203         this_cpu_dec(*rb->pending_refcnt);
1204 }
1205
1206 static unsigned int packet_read_pending(const struct packet_ring_buffer *rb)
1207 {
1208         unsigned int refcnt = 0;
1209         int cpu;
1210
1211         /* We don't use pending refcount in rx_ring. */
1212         if (rb->pending_refcnt == NULL)
1213                 return 0;
1214
1215         for_each_possible_cpu(cpu)
1216                 refcnt += *per_cpu_ptr(rb->pending_refcnt, cpu);
1217
1218         return refcnt;
1219 }
1220
1221 static int packet_alloc_pending(struct packet_sock *po)
1222 {
1223         po->rx_ring.pending_refcnt = NULL;
1224
1225         po->tx_ring.pending_refcnt = alloc_percpu(unsigned int);
1226         if (unlikely(po->tx_ring.pending_refcnt == NULL))
1227                 return -ENOBUFS;
1228
1229         return 0;
1230 }
1231
1232 static void packet_free_pending(struct packet_sock *po)
1233 {
1234         free_percpu(po->tx_ring.pending_refcnt);
1235 }
1236
1237 #define ROOM_POW_OFF    2
1238 #define ROOM_NONE       0x0
1239 #define ROOM_LOW        0x1
1240 #define ROOM_NORMAL     0x2
1241
1242 static bool __tpacket_has_room(struct packet_sock *po, int pow_off)
1243 {
1244         int idx, len;
1245
1246         len = po->rx_ring.frame_max + 1;
1247         idx = po->rx_ring.head;
1248         if (pow_off)
1249                 idx += len >> pow_off;
1250         if (idx >= len)
1251                 idx -= len;
1252         return packet_lookup_frame(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1253 }
1254
1255 static bool __tpacket_v3_has_room(struct packet_sock *po, int pow_off)
1256 {
1257         int idx, len;
1258
1259         len = po->rx_ring.prb_bdqc.knum_blocks;
1260         idx = po->rx_ring.prb_bdqc.kactive_blk_num;
1261         if (pow_off)
1262                 idx += len >> pow_off;
1263         if (idx >= len)
1264                 idx -= len;
1265         return prb_lookup_block(po, &po->rx_ring, idx, TP_STATUS_KERNEL);
1266 }
1267
1268 static int __packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1269 {
1270         struct sock *sk = &po->sk;
1271         int ret = ROOM_NONE;
1272
1273         if (po->prot_hook.func != tpacket_rcv) {
1274                 int avail = sk->sk_rcvbuf - atomic_read(&sk->sk_rmem_alloc)
1275                                           - (skb ? skb->truesize : 0);
1276                 if (avail > (sk->sk_rcvbuf >> ROOM_POW_OFF))
1277                         return ROOM_NORMAL;
1278                 else if (avail > 0)
1279                         return ROOM_LOW;
1280                 else
1281                         return ROOM_NONE;
1282         }
1283
1284         if (po->tp_version == TPACKET_V3) {
1285                 if (__tpacket_v3_has_room(po, ROOM_POW_OFF))
1286                         ret = ROOM_NORMAL;
1287                 else if (__tpacket_v3_has_room(po, 0))
1288                         ret = ROOM_LOW;
1289         } else {
1290                 if (__tpacket_has_room(po, ROOM_POW_OFF))
1291                         ret = ROOM_NORMAL;
1292                 else if (__tpacket_has_room(po, 0))
1293                         ret = ROOM_LOW;
1294         }
1295
1296         return ret;
1297 }
1298
1299 static int packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1300 {
1301         int ret;
1302         bool has_room;
1303
1304         spin_lock_bh(&po->sk.sk_receive_queue.lock);
1305         ret = __packet_rcv_has_room(po, skb);
1306         has_room = ret == ROOM_NORMAL;
1307         if (po->pressure == has_room)
1308                 po->pressure = !has_room;
1309         spin_unlock_bh(&po->sk.sk_receive_queue.lock);
1310
1311         return ret;
1312 }
1313
1314 static void packet_sock_destruct(struct sock *sk)
1315 {
1316         skb_queue_purge(&sk->sk_error_queue);
1317
1318         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1319         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1320
1321         if (!sock_flag(sk, SOCK_DEAD)) {
1322                 pr_err("Attempt to release alive packet socket: %p\n", sk);
1323                 return;
1324         }
1325
1326         sk_refcnt_debug_dec(sk);
1327 }
1328
1329 static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1330 {
1331         int x = atomic_read(&f->rr_cur) + 1;
1332
1333         if (x >= num)
1334                 x = 0;
1335
1336         return x;
1337 }
1338
1339 static bool fanout_flow_is_huge(struct packet_sock *po, struct sk_buff *skb)
1340 {
1341         u32 rxhash;
1342         int i, count = 0;
1343
1344         rxhash = skb_get_hash(skb);
1345         for (i = 0; i < ROLLOVER_HLEN; i++)
1346                 if (po->rollover->history[i] == rxhash)
1347                         count++;
1348
1349         po->rollover->history[prandom_u32() % ROLLOVER_HLEN] = rxhash;
1350         return count > (ROLLOVER_HLEN >> 1);
1351 }
1352
1353 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1354                                       struct sk_buff *skb,
1355                                       unsigned int num)
1356 {
1357         return reciprocal_scale(skb_get_hash(skb), num);
1358 }
1359
1360 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1361                                     struct sk_buff *skb,
1362                                     unsigned int num)
1363 {
1364         int cur, old;
1365
1366         cur = atomic_read(&f->rr_cur);
1367         while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1368                                      fanout_rr_next(f, num))) != cur)
1369                 cur = old;
1370         return cur;
1371 }
1372
1373 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1374                                      struct sk_buff *skb,
1375                                      unsigned int num)
1376 {
1377         return smp_processor_id() % num;
1378 }
1379
1380 static unsigned int fanout_demux_rnd(struct packet_fanout *f,
1381                                      struct sk_buff *skb,
1382                                      unsigned int num)
1383 {
1384         return prandom_u32_max(num);
1385 }
1386
1387 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1388                                           struct sk_buff *skb,
1389                                           unsigned int idx, bool try_self,
1390                                           unsigned int num)
1391 {
1392         struct packet_sock *po, *po_next;
1393         unsigned int i, j, room = ROOM_NONE;
1394
1395         po = pkt_sk(f->arr[idx]);
1396
1397         if (try_self) {
1398                 room = packet_rcv_has_room(po, skb);
1399                 if (room == ROOM_NORMAL ||
1400                     (room == ROOM_LOW && !fanout_flow_is_huge(po, skb)))
1401                         return idx;
1402         }
1403
1404         i = j = min_t(int, po->rollover->sock, num - 1);
1405         do {
1406                 po_next = pkt_sk(f->arr[i]);
1407                 if (po_next != po && !po_next->pressure &&
1408                     packet_rcv_has_room(po_next, skb) == ROOM_NORMAL) {
1409                         if (i != j)
1410                                 po->rollover->sock = i;
1411                         atomic_long_inc(&po->rollover->num);
1412                         if (room == ROOM_LOW)
1413                                 atomic_long_inc(&po->rollover->num_huge);
1414                         return i;
1415                 }
1416
1417                 if (++i == num)
1418                         i = 0;
1419         } while (i != j);
1420
1421         atomic_long_inc(&po->rollover->num_failed);
1422         return idx;
1423 }
1424
1425 static unsigned int fanout_demux_qm(struct packet_fanout *f,
1426                                     struct sk_buff *skb,
1427                                     unsigned int num)
1428 {
1429         return skb_get_queue_mapping(skb) % num;
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 = f->num_members;
1442         struct packet_sock *po;
1443         unsigned int idx;
1444
1445         if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1446             !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(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         }
1477
1478         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER))
1479                 idx = fanout_demux_rollover(f, skb, idx, true, num);
1480
1481         po = pkt_sk(f->arr[idx]);
1482         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1483 }
1484
1485 DEFINE_MUTEX(fanout_mutex);
1486 EXPORT_SYMBOL_GPL(fanout_mutex);
1487 static LIST_HEAD(fanout_list);
1488
1489 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1490 {
1491         struct packet_fanout *f = po->fanout;
1492
1493         spin_lock(&f->lock);
1494         f->arr[f->num_members] = sk;
1495         smp_wmb();
1496         f->num_members++;
1497         spin_unlock(&f->lock);
1498 }
1499
1500 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1501 {
1502         struct packet_fanout *f = po->fanout;
1503         int i;
1504
1505         spin_lock(&f->lock);
1506         for (i = 0; i < f->num_members; i++) {
1507                 if (f->arr[i] == sk)
1508                         break;
1509         }
1510         BUG_ON(i >= f->num_members);
1511         f->arr[i] = f->arr[f->num_members - 1];
1512         f->num_members--;
1513         spin_unlock(&f->lock);
1514 }
1515
1516 static bool match_fanout_group(struct packet_type *ptype, struct sock *sk)
1517 {
1518         if (ptype->af_packet_priv == (void *)((struct packet_sock *)sk)->fanout)
1519                 return true;
1520
1521         return false;
1522 }
1523
1524 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1525 {
1526         struct packet_sock *po = pkt_sk(sk);
1527         struct packet_fanout *f, *match;
1528         u8 type = type_flags & 0xff;
1529         u8 flags = type_flags >> 8;
1530         int err;
1531
1532         switch (type) {
1533         case PACKET_FANOUT_ROLLOVER:
1534                 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1535                         return -EINVAL;
1536         case PACKET_FANOUT_HASH:
1537         case PACKET_FANOUT_LB:
1538         case PACKET_FANOUT_CPU:
1539         case PACKET_FANOUT_RND:
1540         case PACKET_FANOUT_QM:
1541                 break;
1542         default:
1543                 return -EINVAL;
1544         }
1545
1546         if (!po->running)
1547                 return -EINVAL;
1548
1549         if (po->fanout)
1550                 return -EALREADY;
1551
1552         if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER) {
1553                 po->rollover = kzalloc(sizeof(*po->rollover), GFP_KERNEL);
1554                 if (!po->rollover)
1555                         return -ENOMEM;
1556                 atomic_long_set(&po->rollover->num, 0);
1557                 atomic_long_set(&po->rollover->num_huge, 0);
1558                 atomic_long_set(&po->rollover->num_failed, 0);
1559         }
1560
1561         mutex_lock(&fanout_mutex);
1562         match = NULL;
1563         list_for_each_entry(f, &fanout_list, list) {
1564                 if (f->id == id &&
1565                     read_pnet(&f->net) == sock_net(sk)) {
1566                         match = f;
1567                         break;
1568                 }
1569         }
1570         err = -EINVAL;
1571         if (match && match->flags != flags)
1572                 goto out;
1573         if (!match) {
1574                 err = -ENOMEM;
1575                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1576                 if (!match)
1577                         goto out;
1578                 write_pnet(&match->net, sock_net(sk));
1579                 match->id = id;
1580                 match->type = type;
1581                 match->flags = flags;
1582                 atomic_set(&match->rr_cur, 0);
1583                 INIT_LIST_HEAD(&match->list);
1584                 spin_lock_init(&match->lock);
1585                 atomic_set(&match->sk_ref, 0);
1586                 match->prot_hook.type = po->prot_hook.type;
1587                 match->prot_hook.dev = po->prot_hook.dev;
1588                 match->prot_hook.func = packet_rcv_fanout;
1589                 match->prot_hook.af_packet_priv = match;
1590                 match->prot_hook.id_match = match_fanout_group;
1591                 dev_add_pack(&match->prot_hook);
1592                 list_add(&match->list, &fanout_list);
1593         }
1594         err = -EINVAL;
1595         if (match->type == type &&
1596             match->prot_hook.type == po->prot_hook.type &&
1597             match->prot_hook.dev == po->prot_hook.dev) {
1598                 err = -ENOSPC;
1599                 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1600                         __dev_remove_pack(&po->prot_hook);
1601                         po->fanout = match;
1602                         atomic_inc(&match->sk_ref);
1603                         __fanout_link(sk, po);
1604                         err = 0;
1605                 }
1606         }
1607 out:
1608         mutex_unlock(&fanout_mutex);
1609         if (err) {
1610                 kfree(po->rollover);
1611                 po->rollover = NULL;
1612         }
1613         return err;
1614 }
1615
1616 static void fanout_release(struct sock *sk)
1617 {
1618         struct packet_sock *po = pkt_sk(sk);
1619         struct packet_fanout *f;
1620
1621         f = po->fanout;
1622         if (!f)
1623                 return;
1624
1625         mutex_lock(&fanout_mutex);
1626         po->fanout = NULL;
1627
1628         if (atomic_dec_and_test(&f->sk_ref)) {
1629                 list_del(&f->list);
1630                 dev_remove_pack(&f->prot_hook);
1631                 kfree(f);
1632         }
1633         mutex_unlock(&fanout_mutex);
1634
1635         kfree(po->rollover);
1636 }
1637
1638 static const struct proto_ops packet_ops;
1639
1640 static const struct proto_ops packet_ops_spkt;
1641
1642 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1643                            struct packet_type *pt, struct net_device *orig_dev)
1644 {
1645         struct sock *sk;
1646         struct sockaddr_pkt *spkt;
1647
1648         /*
1649          *      When we registered the protocol we saved the socket in the data
1650          *      field for just this event.
1651          */
1652
1653         sk = pt->af_packet_priv;
1654
1655         /*
1656          *      Yank back the headers [hope the device set this
1657          *      right or kerboom...]
1658          *
1659          *      Incoming packets have ll header pulled,
1660          *      push it back.
1661          *
1662          *      For outgoing ones skb->data == skb_mac_header(skb)
1663          *      so that this procedure is noop.
1664          */
1665
1666         if (skb->pkt_type == PACKET_LOOPBACK)
1667                 goto out;
1668
1669         if (!net_eq(dev_net(dev), sock_net(sk)))
1670                 goto out;
1671
1672         skb = skb_share_check(skb, GFP_ATOMIC);
1673         if (skb == NULL)
1674                 goto oom;
1675
1676         /* drop any routing info */
1677         skb_dst_drop(skb);
1678
1679         /* drop conntrack reference */
1680         nf_reset(skb);
1681
1682         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1683
1684         skb_push(skb, skb->data - skb_mac_header(skb));
1685
1686         /*
1687          *      The SOCK_PACKET socket receives _all_ frames.
1688          */
1689
1690         spkt->spkt_family = dev->type;
1691         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1692         spkt->spkt_protocol = skb->protocol;
1693
1694         /*
1695          *      Charge the memory to the socket. This is done specifically
1696          *      to prevent sockets using all the memory up.
1697          */
1698
1699         if (sock_queue_rcv_skb(sk, skb) == 0)
1700                 return 0;
1701
1702 out:
1703         kfree_skb(skb);
1704 oom:
1705         return 0;
1706 }
1707
1708
1709 /*
1710  *      Output a raw packet to a device layer. This bypasses all the other
1711  *      protocol layers and you must therefore supply it with a complete frame
1712  */
1713
1714 static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg,
1715                                size_t len)
1716 {
1717         struct sock *sk = sock->sk;
1718         DECLARE_SOCKADDR(struct sockaddr_pkt *, saddr, msg->msg_name);
1719         struct sk_buff *skb = NULL;
1720         struct net_device *dev;
1721         __be16 proto = 0;
1722         int err;
1723         int extra_len = 0;
1724
1725         /*
1726          *      Get and verify the address.
1727          */
1728
1729         if (saddr) {
1730                 if (msg->msg_namelen < sizeof(struct sockaddr))
1731                         return -EINVAL;
1732                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1733                         proto = saddr->spkt_protocol;
1734         } else
1735                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1736
1737         /*
1738          *      Find the device first to size check it
1739          */
1740
1741         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1742 retry:
1743         rcu_read_lock();
1744         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1745         err = -ENODEV;
1746         if (dev == NULL)
1747                 goto out_unlock;
1748
1749         err = -ENETDOWN;
1750         if (!(dev->flags & IFF_UP))
1751                 goto out_unlock;
1752
1753         /*
1754          * You may not queue a frame bigger than the mtu. This is the lowest level
1755          * raw protocol and you must do your own fragmentation at this level.
1756          */
1757
1758         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1759                 if (!netif_supports_nofcs(dev)) {
1760                         err = -EPROTONOSUPPORT;
1761                         goto out_unlock;
1762                 }
1763                 extra_len = 4; /* We're doing our own CRC */
1764         }
1765
1766         err = -EMSGSIZE;
1767         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1768                 goto out_unlock;
1769
1770         if (!skb) {
1771                 size_t reserved = LL_RESERVED_SPACE(dev);
1772                 int tlen = dev->needed_tailroom;
1773                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1774
1775                 rcu_read_unlock();
1776                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1777                 if (skb == NULL)
1778                         return -ENOBUFS;
1779                 /* FIXME: Save some space for broken drivers that write a hard
1780                  * header at transmission time by themselves. PPP is the notable
1781                  * one here. This should really be fixed at the driver level.
1782                  */
1783                 skb_reserve(skb, reserved);
1784                 skb_reset_network_header(skb);
1785
1786                 /* Try to align data part correctly */
1787                 if (hhlen) {
1788                         skb->data -= hhlen;
1789                         skb->tail -= hhlen;
1790                         if (len < hhlen)
1791                                 skb_reset_network_header(skb);
1792                 }
1793                 err = memcpy_from_msg(skb_put(skb, len), msg, len);
1794                 if (err)
1795                         goto out_free;
1796                 goto retry;
1797         }
1798
1799         if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1800                 /* Earlier code assumed this would be a VLAN pkt,
1801                  * double-check this now that we have the actual
1802                  * packet in hand.
1803                  */
1804                 struct ethhdr *ehdr;
1805                 skb_reset_mac_header(skb);
1806                 ehdr = eth_hdr(skb);
1807                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1808                         err = -EMSGSIZE;
1809                         goto out_unlock;
1810                 }
1811         }
1812
1813         skb->protocol = proto;
1814         skb->dev = dev;
1815         skb->priority = sk->sk_priority;
1816         skb->mark = sk->sk_mark;
1817
1818         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1819
1820         if (unlikely(extra_len == 4))
1821                 skb->no_fcs = 1;
1822
1823         skb_probe_transport_header(skb, 0);
1824
1825         dev_queue_xmit(skb);
1826         rcu_read_unlock();
1827         return len;
1828
1829 out_unlock:
1830         rcu_read_unlock();
1831 out_free:
1832         kfree_skb(skb);
1833         return err;
1834 }
1835
1836 static unsigned int run_filter(const struct sk_buff *skb,
1837                                       const struct sock *sk,
1838                                       unsigned int res)
1839 {
1840         struct sk_filter *filter;
1841
1842         rcu_read_lock();
1843         filter = rcu_dereference(sk->sk_filter);
1844         if (filter != NULL)
1845                 res = SK_RUN_FILTER(filter, skb);
1846         rcu_read_unlock();
1847
1848         return res;
1849 }
1850
1851 /*
1852  * This function makes lazy skb cloning in hope that most of packets
1853  * are discarded by BPF.
1854  *
1855  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1856  * and skb->cb are mangled. It works because (and until) packets
1857  * falling here are owned by current CPU. Output packets are cloned
1858  * by dev_queue_xmit_nit(), input packets are processed by net_bh
1859  * sequencially, so that if we return skb to original state on exit,
1860  * we will not harm anyone.
1861  */
1862
1863 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1864                       struct packet_type *pt, struct net_device *orig_dev)
1865 {
1866         struct sock *sk;
1867         struct sockaddr_ll *sll;
1868         struct packet_sock *po;
1869         u8 *skb_head = skb->data;
1870         int skb_len = skb->len;
1871         unsigned int snaplen, res;
1872
1873         if (skb->pkt_type == PACKET_LOOPBACK)
1874                 goto drop;
1875
1876         sk = pt->af_packet_priv;
1877         po = pkt_sk(sk);
1878
1879         if (!net_eq(dev_net(dev), sock_net(sk)))
1880                 goto drop;
1881
1882         skb->dev = dev;
1883
1884         if (dev->header_ops) {
1885                 /* The device has an explicit notion of ll header,
1886                  * exported to higher levels.
1887                  *
1888                  * Otherwise, the device hides details of its frame
1889                  * structure, so that corresponding packet head is
1890                  * never delivered to user.
1891                  */
1892                 if (sk->sk_type != SOCK_DGRAM)
1893                         skb_push(skb, skb->data - skb_mac_header(skb));
1894                 else if (skb->pkt_type == PACKET_OUTGOING) {
1895                         /* Special case: outgoing packets have ll header at head */
1896                         skb_pull(skb, skb_network_offset(skb));
1897                 }
1898         }
1899
1900         snaplen = skb->len;
1901
1902         res = run_filter(skb, sk, snaplen);
1903         if (!res)
1904                 goto drop_n_restore;
1905         if (snaplen > res)
1906                 snaplen = res;
1907
1908         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1909                 goto drop_n_acct;
1910
1911         if (skb_shared(skb)) {
1912                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1913                 if (nskb == NULL)
1914                         goto drop_n_acct;
1915
1916                 if (skb_head != skb->data) {
1917                         skb->data = skb_head;
1918                         skb->len = skb_len;
1919                 }
1920                 consume_skb(skb);
1921                 skb = nskb;
1922         }
1923
1924         sock_skb_cb_check_size(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8);
1925
1926         sll = &PACKET_SKB_CB(skb)->sa.ll;
1927         sll->sll_hatype = dev->type;
1928         sll->sll_pkttype = skb->pkt_type;
1929         if (unlikely(po->origdev))
1930                 sll->sll_ifindex = orig_dev->ifindex;
1931         else
1932                 sll->sll_ifindex = dev->ifindex;
1933
1934         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1935
1936         /* sll->sll_family and sll->sll_protocol are set in packet_recvmsg().
1937          * Use their space for storing the original skb length.
1938          */
1939         PACKET_SKB_CB(skb)->sa.origlen = skb->len;
1940
1941         if (pskb_trim(skb, snaplen))
1942                 goto drop_n_acct;
1943
1944         skb_set_owner_r(skb, sk);
1945         skb->dev = NULL;
1946         skb_dst_drop(skb);
1947
1948         /* drop conntrack reference */
1949         nf_reset(skb);
1950
1951         spin_lock(&sk->sk_receive_queue.lock);
1952         po->stats.stats1.tp_packets++;
1953         sock_skb_set_dropcount(sk, skb);
1954         __skb_queue_tail(&sk->sk_receive_queue, skb);
1955         spin_unlock(&sk->sk_receive_queue.lock);
1956         sk->sk_data_ready(sk);
1957         return 0;
1958
1959 drop_n_acct:
1960         spin_lock(&sk->sk_receive_queue.lock);
1961         po->stats.stats1.tp_drops++;
1962         atomic_inc(&sk->sk_drops);
1963         spin_unlock(&sk->sk_receive_queue.lock);
1964
1965 drop_n_restore:
1966         if (skb_head != skb->data && skb_shared(skb)) {
1967                 skb->data = skb_head;
1968                 skb->len = skb_len;
1969         }
1970 drop:
1971         consume_skb(skb);
1972         return 0;
1973 }
1974
1975 static int tpacket_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 packet_sock *po;
1980         struct sockaddr_ll *sll;
1981         union tpacket_uhdr h;
1982         u8 *skb_head = skb->data;
1983         int skb_len = skb->len;
1984         unsigned int snaplen, res;
1985         unsigned long status = TP_STATUS_USER;
1986         unsigned short macoff, netoff, hdrlen;
1987         struct sk_buff *copy_skb = NULL;
1988         struct timespec ts;
1989         __u32 ts_status;
1990
1991         /* struct tpacket{2,3}_hdr is aligned to a multiple of TPACKET_ALIGNMENT.
1992          * We may add members to them until current aligned size without forcing
1993          * userspace to call getsockopt(..., PACKET_HDRLEN, ...).
1994          */
1995         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h2)) != 32);
1996         BUILD_BUG_ON(TPACKET_ALIGN(sizeof(*h.h3)) != 48);
1997
1998         if (skb->pkt_type == PACKET_LOOPBACK)
1999                 goto drop;
2000
2001         sk = pt->af_packet_priv;
2002         po = pkt_sk(sk);
2003
2004         if (!net_eq(dev_net(dev), sock_net(sk)))
2005                 goto drop;
2006
2007         if (dev->header_ops) {
2008                 if (sk->sk_type != SOCK_DGRAM)
2009                         skb_push(skb, skb->data - skb_mac_header(skb));
2010                 else if (skb->pkt_type == PACKET_OUTGOING) {
2011                         /* Special case: outgoing packets have ll header at head */
2012                         skb_pull(skb, skb_network_offset(skb));
2013                 }
2014         }
2015
2016         snaplen = skb->len;
2017
2018         res = run_filter(skb, sk, snaplen);
2019         if (!res)
2020                 goto drop_n_restore;
2021
2022         if (skb->ip_summed == CHECKSUM_PARTIAL)
2023                 status |= TP_STATUS_CSUMNOTREADY;
2024         else if (skb->pkt_type != PACKET_OUTGOING &&
2025                  (skb->ip_summed == CHECKSUM_COMPLETE ||
2026                   skb_csum_unnecessary(skb)))
2027                 status |= TP_STATUS_CSUM_VALID;
2028
2029         if (snaplen > res)
2030                 snaplen = res;
2031
2032         if (sk->sk_type == SOCK_DGRAM) {
2033                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
2034                                   po->tp_reserve;
2035         } else {
2036                 unsigned int maclen = skb_network_offset(skb);
2037                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
2038                                        (maclen < 16 ? 16 : maclen)) +
2039                         po->tp_reserve;
2040                 macoff = netoff - maclen;
2041         }
2042         if (po->tp_version <= TPACKET_V2) {
2043                 if (macoff + snaplen > po->rx_ring.frame_size) {
2044                         if (po->copy_thresh &&
2045                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
2046                                 if (skb_shared(skb)) {
2047                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
2048                                 } else {
2049                                         copy_skb = skb_get(skb);
2050                                         skb_head = skb->data;
2051                                 }
2052                                 if (copy_skb)
2053                                         skb_set_owner_r(copy_skb, sk);
2054                         }
2055                         snaplen = po->rx_ring.frame_size - macoff;
2056                         if ((int)snaplen < 0)
2057                                 snaplen = 0;
2058                 }
2059         } else if (unlikely(macoff + snaplen >
2060                             GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
2061                 u32 nval;
2062
2063                 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
2064                 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
2065                             snaplen, nval, macoff);
2066                 snaplen = nval;
2067                 if (unlikely((int)snaplen < 0)) {
2068                         snaplen = 0;
2069                         macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
2070                 }
2071         }
2072         spin_lock(&sk->sk_receive_queue.lock);
2073         h.raw = packet_current_rx_frame(po, skb,
2074                                         TP_STATUS_KERNEL, (macoff+snaplen));
2075         if (!h.raw)
2076                 goto ring_is_full;
2077         if (po->tp_version <= TPACKET_V2) {
2078                 packet_increment_rx_head(po, &po->rx_ring);
2079         /*
2080          * LOSING will be reported till you read the stats,
2081          * because it's COR - Clear On Read.
2082          * Anyways, moving it for V1/V2 only as V3 doesn't need this
2083          * at packet level.
2084          */
2085                 if (po->stats.stats1.tp_drops)
2086                         status |= TP_STATUS_LOSING;
2087         }
2088         po->stats.stats1.tp_packets++;
2089         if (copy_skb) {
2090                 status |= TP_STATUS_COPY;
2091                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
2092         }
2093         spin_unlock(&sk->sk_receive_queue.lock);
2094
2095         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
2096
2097         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
2098                 getnstimeofday(&ts);
2099
2100         status |= ts_status;
2101
2102         switch (po->tp_version) {
2103         case TPACKET_V1:
2104                 h.h1->tp_len = skb->len;
2105                 h.h1->tp_snaplen = snaplen;
2106                 h.h1->tp_mac = macoff;
2107                 h.h1->tp_net = netoff;
2108                 h.h1->tp_sec = ts.tv_sec;
2109                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
2110                 hdrlen = sizeof(*h.h1);
2111                 break;
2112         case TPACKET_V2:
2113                 h.h2->tp_len = skb->len;
2114                 h.h2->tp_snaplen = snaplen;
2115                 h.h2->tp_mac = macoff;
2116                 h.h2->tp_net = netoff;
2117                 h.h2->tp_sec = ts.tv_sec;
2118                 h.h2->tp_nsec = ts.tv_nsec;
2119                 if (skb_vlan_tag_present(skb)) {
2120                         h.h2->tp_vlan_tci = skb_vlan_tag_get(skb);
2121                         h.h2->tp_vlan_tpid = ntohs(skb->vlan_proto);
2122                         status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
2123                 } else {
2124                         h.h2->tp_vlan_tci = 0;
2125                         h.h2->tp_vlan_tpid = 0;
2126                 }
2127                 memset(h.h2->tp_padding, 0, sizeof(h.h2->tp_padding));
2128                 hdrlen = sizeof(*h.h2);
2129                 break;
2130         case TPACKET_V3:
2131                 /* tp_nxt_offset,vlan are already populated above.
2132                  * So DONT clear those fields here
2133                  */
2134                 h.h3->tp_status |= status;
2135                 h.h3->tp_len = skb->len;
2136                 h.h3->tp_snaplen = snaplen;
2137                 h.h3->tp_mac = macoff;
2138                 h.h3->tp_net = netoff;
2139                 h.h3->tp_sec  = ts.tv_sec;
2140                 h.h3->tp_nsec = ts.tv_nsec;
2141                 memset(h.h3->tp_padding, 0, sizeof(h.h3->tp_padding));
2142                 hdrlen = sizeof(*h.h3);
2143                 break;
2144         default:
2145                 BUG();
2146         }
2147
2148         sll = h.raw + TPACKET_ALIGN(hdrlen);
2149         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
2150         sll->sll_family = AF_PACKET;
2151         sll->sll_hatype = dev->type;
2152         sll->sll_protocol = skb->protocol;
2153         sll->sll_pkttype = skb->pkt_type;
2154         if (unlikely(po->origdev))
2155                 sll->sll_ifindex = orig_dev->ifindex;
2156         else
2157                 sll->sll_ifindex = dev->ifindex;
2158
2159         smp_mb();
2160
2161 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
2162         if (po->tp_version <= TPACKET_V2) {
2163                 u8 *start, *end;
2164
2165                 end = (u8 *) PAGE_ALIGN((unsigned long) h.raw +
2166                                         macoff + snaplen);
2167
2168                 for (start = h.raw; start < end; start += PAGE_SIZE)
2169                         flush_dcache_page(pgv_to_page(start));
2170         }
2171         smp_wmb();
2172 #endif
2173
2174         if (po->tp_version <= TPACKET_V2) {
2175                 __packet_set_status(po, h.raw, status);
2176                 sk->sk_data_ready(sk);
2177         } else {
2178                 prb_clear_blk_fill_status(&po->rx_ring);
2179         }
2180
2181 drop_n_restore:
2182         if (skb_head != skb->data && skb_shared(skb)) {
2183                 skb->data = skb_head;
2184                 skb->len = skb_len;
2185         }
2186 drop:
2187         kfree_skb(skb);
2188         return 0;
2189
2190 ring_is_full:
2191         po->stats.stats1.tp_drops++;
2192         spin_unlock(&sk->sk_receive_queue.lock);
2193
2194         sk->sk_data_ready(sk);
2195         kfree_skb(copy_skb);
2196         goto drop_n_restore;
2197 }
2198
2199 static void tpacket_destruct_skb(struct sk_buff *skb)
2200 {
2201         struct packet_sock *po = pkt_sk(skb->sk);
2202
2203         if (likely(po->tx_ring.pg_vec)) {
2204                 void *ph;
2205                 __u32 ts;
2206
2207                 ph = skb_shinfo(skb)->destructor_arg;
2208                 packet_dec_pending(&po->tx_ring);
2209
2210                 ts = __packet_set_timestamp(po, ph, skb);
2211                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
2212         }
2213
2214         sock_wfree(skb);
2215 }
2216
2217 static bool ll_header_truncated(const struct net_device *dev, int len)
2218 {
2219         /* net device doesn't like empty head */
2220         if (unlikely(len <= dev->hard_header_len)) {
2221                 net_warn_ratelimited("%s: packet size is too short (%d <= %d)\n",
2222                                      current->comm, len, dev->hard_header_len);
2223                 return true;
2224         }
2225
2226         return false;
2227 }
2228
2229 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
2230                 void *frame, struct net_device *dev, int size_max,
2231                 __be16 proto, unsigned char *addr, int hlen)
2232 {
2233         union tpacket_uhdr ph;
2234         int to_write, offset, len, tp_len, nr_frags, len_max;
2235         struct socket *sock = po->sk.sk_socket;
2236         struct page *page;
2237         void *data;
2238         int err;
2239
2240         ph.raw = frame;
2241
2242         skb->protocol = proto;
2243         skb->dev = dev;
2244         skb->priority = po->sk.sk_priority;
2245         skb->mark = po->sk.sk_mark;
2246         sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
2247         skb_shinfo(skb)->destructor_arg = ph.raw;
2248
2249         switch (po->tp_version) {
2250         case TPACKET_V2:
2251                 tp_len = ph.h2->tp_len;
2252                 break;
2253         default:
2254                 tp_len = ph.h1->tp_len;
2255                 break;
2256         }
2257         if (unlikely(tp_len > size_max)) {
2258                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
2259                 return -EMSGSIZE;
2260         }
2261
2262         skb_reserve(skb, hlen);
2263         skb_reset_network_header(skb);
2264
2265         if (!packet_use_direct_xmit(po))
2266                 skb_probe_transport_header(skb, 0);
2267         if (unlikely(po->tp_tx_has_off)) {
2268                 int off_min, off_max, off;
2269                 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2270                 off_max = po->tx_ring.frame_size - tp_len;
2271                 if (sock->type == SOCK_DGRAM) {
2272                         switch (po->tp_version) {
2273                         case TPACKET_V2:
2274                                 off = ph.h2->tp_net;
2275                                 break;
2276                         default:
2277                                 off = ph.h1->tp_net;
2278                                 break;
2279                         }
2280                 } else {
2281                         switch (po->tp_version) {
2282                         case TPACKET_V2:
2283                                 off = ph.h2->tp_mac;
2284                                 break;
2285                         default:
2286                                 off = ph.h1->tp_mac;
2287                                 break;
2288                         }
2289                 }
2290                 if (unlikely((off < off_min) || (off_max < off)))
2291                         return -EINVAL;
2292                 data = ph.raw + off;
2293         } else {
2294                 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2295         }
2296         to_write = tp_len;
2297
2298         if (sock->type == SOCK_DGRAM) {
2299                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2300                                 NULL, tp_len);
2301                 if (unlikely(err < 0))
2302                         return -EINVAL;
2303         } else if (dev->hard_header_len) {
2304                 if (ll_header_truncated(dev, tp_len))
2305                         return -EINVAL;
2306
2307                 skb_push(skb, dev->hard_header_len);
2308                 err = skb_store_bits(skb, 0, data,
2309                                 dev->hard_header_len);
2310                 if (unlikely(err))
2311                         return err;
2312
2313                 data += dev->hard_header_len;
2314                 to_write -= dev->hard_header_len;
2315         }
2316
2317         offset = offset_in_page(data);
2318         len_max = PAGE_SIZE - offset;
2319         len = ((to_write > len_max) ? len_max : to_write);
2320
2321         skb->data_len = to_write;
2322         skb->len += to_write;
2323         skb->truesize += to_write;
2324         atomic_add(to_write, &po->sk.sk_wmem_alloc);
2325
2326         while (likely(to_write)) {
2327                 nr_frags = skb_shinfo(skb)->nr_frags;
2328
2329                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2330                         pr_err("Packet exceed the number of skb frags(%lu)\n",
2331                                MAX_SKB_FRAGS);
2332                         return -EFAULT;
2333                 }
2334
2335                 page = pgv_to_page(data);
2336                 data += len;
2337                 flush_dcache_page(page);
2338                 get_page(page);
2339                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2340                 to_write -= len;
2341                 offset = 0;
2342                 len_max = PAGE_SIZE;
2343                 len = ((to_write > len_max) ? len_max : to_write);
2344         }
2345
2346         return tp_len;
2347 }
2348
2349 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2350 {
2351         struct sk_buff *skb;
2352         struct net_device *dev;
2353         __be16 proto;
2354         int err, reserve = 0;
2355         void *ph;
2356         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2357         bool need_wait = !(msg->msg_flags & MSG_DONTWAIT);
2358         int tp_len, size_max;
2359         unsigned char *addr;
2360         int len_sum = 0;
2361         int status = TP_STATUS_AVAILABLE;
2362         int hlen, tlen;
2363
2364         mutex_lock(&po->pg_vec_lock);
2365
2366         if (likely(saddr == NULL)) {
2367                 dev     = packet_cached_dev_get(po);
2368                 proto   = po->num;
2369                 addr    = NULL;
2370         } else {
2371                 err = -EINVAL;
2372                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2373                         goto out;
2374                 if (msg->msg_namelen < (saddr->sll_halen
2375                                         + offsetof(struct sockaddr_ll,
2376                                                 sll_addr)))
2377                         goto out;
2378                 proto   = saddr->sll_protocol;
2379                 addr    = saddr->sll_addr;
2380                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2381         }
2382
2383         err = -ENXIO;
2384         if (unlikely(dev == NULL))
2385                 goto out;
2386         err = -ENETDOWN;
2387         if (unlikely(!(dev->flags & IFF_UP)))
2388                 goto out_put;
2389
2390         reserve = dev->hard_header_len + VLAN_HLEN;
2391         size_max = po->tx_ring.frame_size
2392                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2393
2394         if (size_max > dev->mtu + reserve)
2395                 size_max = dev->mtu + reserve;
2396
2397         do {
2398                 ph = packet_current_frame(po, &po->tx_ring,
2399                                           TP_STATUS_SEND_REQUEST);
2400                 if (unlikely(ph == NULL)) {
2401                         if (need_wait && need_resched())
2402                                 schedule();
2403                         continue;
2404                 }
2405
2406                 status = TP_STATUS_SEND_REQUEST;
2407                 hlen = LL_RESERVED_SPACE(dev);
2408                 tlen = dev->needed_tailroom;
2409                 skb = sock_alloc_send_skb(&po->sk,
2410                                 hlen + tlen + sizeof(struct sockaddr_ll),
2411                                 !need_wait, &err);
2412
2413                 if (unlikely(skb == NULL)) {
2414                         /* we assume the socket was initially writeable ... */
2415                         if (likely(len_sum > 0))
2416                                 err = len_sum;
2417                         goto out_status;
2418                 }
2419                 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2420                                           addr, hlen);
2421                 if (tp_len > dev->mtu + dev->hard_header_len) {
2422                         struct ethhdr *ehdr;
2423                         /* Earlier code assumed this would be a VLAN pkt,
2424                          * double-check this now that we have the actual
2425                          * packet in hand.
2426                          */
2427
2428                         skb_reset_mac_header(skb);
2429                         ehdr = eth_hdr(skb);
2430                         if (ehdr->h_proto != htons(ETH_P_8021Q))
2431                                 tp_len = -EMSGSIZE;
2432                 }
2433                 if (unlikely(tp_len < 0)) {
2434                         if (po->tp_loss) {
2435                                 __packet_set_status(po, ph,
2436                                                 TP_STATUS_AVAILABLE);
2437                                 packet_increment_head(&po->tx_ring);
2438                                 kfree_skb(skb);
2439                                 continue;
2440                         } else {
2441                                 status = TP_STATUS_WRONG_FORMAT;
2442                                 err = tp_len;
2443                                 goto out_status;
2444                         }
2445                 }
2446
2447                 packet_pick_tx_queue(dev, skb);
2448
2449                 skb->destructor = tpacket_destruct_skb;
2450                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2451                 packet_inc_pending(&po->tx_ring);
2452
2453                 status = TP_STATUS_SEND_REQUEST;
2454                 err = po->xmit(skb);
2455                 if (unlikely(err > 0)) {
2456                         err = net_xmit_errno(err);
2457                         if (err && __packet_get_status(po, ph) ==
2458                                    TP_STATUS_AVAILABLE) {
2459                                 /* skb was destructed already */
2460                                 skb = NULL;
2461                                 goto out_status;
2462                         }
2463                         /*
2464                          * skb was dropped but not destructed yet;
2465                          * let's treat it like congestion or err < 0
2466                          */
2467                         err = 0;
2468                 }
2469                 packet_increment_head(&po->tx_ring);
2470                 len_sum += tp_len;
2471         } while (likely((ph != NULL) ||
2472                 /* Note: packet_read_pending() might be slow if we have
2473                  * to call it as it's per_cpu variable, but in fast-path
2474                  * we already short-circuit the loop with the first
2475                  * condition, and luckily don't have to go that path
2476                  * anyway.
2477                  */
2478                  (need_wait && packet_read_pending(&po->tx_ring))));
2479
2480         err = len_sum;
2481         goto out_put;
2482
2483 out_status:
2484         __packet_set_status(po, ph, status);
2485         kfree_skb(skb);
2486 out_put:
2487         dev_put(dev);
2488 out:
2489         mutex_unlock(&po->pg_vec_lock);
2490         return err;
2491 }
2492
2493 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2494                                         size_t reserve, size_t len,
2495                                         size_t linear, int noblock,
2496                                         int *err)
2497 {
2498         struct sk_buff *skb;
2499
2500         /* Under a page?  Don't bother with paged skb. */
2501         if (prepad + len < PAGE_SIZE || !linear)
2502                 linear = len;
2503
2504         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2505                                    err, 0);
2506         if (!skb)
2507                 return NULL;
2508
2509         skb_reserve(skb, reserve);
2510         skb_put(skb, linear);
2511         skb->data_len = len - linear;
2512         skb->len += len - linear;
2513
2514         return skb;
2515 }
2516
2517 static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
2518 {
2519         struct sock *sk = sock->sk;
2520         DECLARE_SOCKADDR(struct sockaddr_ll *, saddr, msg->msg_name);
2521         struct sk_buff *skb;
2522         struct net_device *dev;
2523         __be16 proto;
2524         unsigned char *addr;
2525         int err, reserve = 0;
2526         struct virtio_net_hdr vnet_hdr = { 0 };
2527         int offset = 0;
2528         int vnet_hdr_len;
2529         struct packet_sock *po = pkt_sk(sk);
2530         unsigned short gso_type = 0;
2531         int hlen, tlen;
2532         int extra_len = 0;
2533         ssize_t n;
2534
2535         /*
2536          *      Get and verify the address.
2537          */
2538
2539         if (likely(saddr == NULL)) {
2540                 dev     = packet_cached_dev_get(po);
2541                 proto   = po->num;
2542                 addr    = NULL;
2543         } else {
2544                 err = -EINVAL;
2545                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2546                         goto out;
2547                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2548                         goto out;
2549                 proto   = saddr->sll_protocol;
2550                 addr    = saddr->sll_addr;
2551                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2552         }
2553
2554         err = -ENXIO;
2555         if (unlikely(dev == NULL))
2556                 goto out_unlock;
2557         err = -ENETDOWN;
2558         if (unlikely(!(dev->flags & IFF_UP)))
2559                 goto out_unlock;
2560
2561         if (sock->type == SOCK_RAW)
2562                 reserve = dev->hard_header_len;
2563         if (po->has_vnet_hdr) {
2564                 vnet_hdr_len = sizeof(vnet_hdr);
2565
2566                 err = -EINVAL;
2567                 if (len < vnet_hdr_len)
2568                         goto out_unlock;
2569
2570                 len -= vnet_hdr_len;
2571
2572                 err = -EFAULT;
2573                 n = copy_from_iter(&vnet_hdr, vnet_hdr_len, &msg->msg_iter);
2574                 if (n != vnet_hdr_len)
2575                         goto out_unlock;
2576
2577                 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2578                     (__virtio16_to_cpu(false, vnet_hdr.csum_start) +
2579                      __virtio16_to_cpu(false, vnet_hdr.csum_offset) + 2 >
2580                       __virtio16_to_cpu(false, vnet_hdr.hdr_len)))
2581                         vnet_hdr.hdr_len = __cpu_to_virtio16(false,
2582                                  __virtio16_to_cpu(false, vnet_hdr.csum_start) +
2583                                 __virtio16_to_cpu(false, vnet_hdr.csum_offset) + 2);
2584
2585                 err = -EINVAL;
2586                 if (__virtio16_to_cpu(false, vnet_hdr.hdr_len) > len)
2587                         goto out_unlock;
2588
2589                 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2590                         switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2591                         case VIRTIO_NET_HDR_GSO_TCPV4:
2592                                 gso_type = SKB_GSO_TCPV4;
2593                                 break;
2594                         case VIRTIO_NET_HDR_GSO_TCPV6:
2595                                 gso_type = SKB_GSO_TCPV6;
2596                                 break;
2597                         case VIRTIO_NET_HDR_GSO_UDP:
2598                                 gso_type = SKB_GSO_UDP;
2599                                 break;
2600                         default:
2601                                 goto out_unlock;
2602                         }
2603
2604                         if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2605                                 gso_type |= SKB_GSO_TCP_ECN;
2606
2607                         if (vnet_hdr.gso_size == 0)
2608                                 goto out_unlock;
2609
2610                 }
2611         }
2612
2613         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2614                 if (!netif_supports_nofcs(dev)) {
2615                         err = -EPROTONOSUPPORT;
2616                         goto out_unlock;
2617                 }
2618                 extra_len = 4; /* We're doing our own CRC */
2619         }
2620
2621         err = -EMSGSIZE;
2622         if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2623                 goto out_unlock;
2624
2625         err = -ENOBUFS;
2626         hlen = LL_RESERVED_SPACE(dev);
2627         tlen = dev->needed_tailroom;
2628         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len,
2629                                __virtio16_to_cpu(false, vnet_hdr.hdr_len),
2630                                msg->msg_flags & MSG_DONTWAIT, &err);
2631         if (skb == NULL)
2632                 goto out_unlock;
2633
2634         skb_set_network_header(skb, reserve);
2635
2636         err = -EINVAL;
2637         if (sock->type == SOCK_DGRAM) {
2638                 offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len);
2639                 if (unlikely(offset < 0))
2640                         goto out_free;
2641         } else {
2642                 if (ll_header_truncated(dev, len))
2643                         goto out_free;
2644         }
2645
2646         /* Returns -EFAULT on error */
2647         err = skb_copy_datagram_from_iter(skb, offset, &msg->msg_iter, len);
2648         if (err)
2649                 goto out_free;
2650
2651         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2652
2653         if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2654                 /* Earlier code assumed this would be a VLAN pkt,
2655                  * double-check this now that we have the actual
2656                  * packet in hand.
2657                  */
2658                 struct ethhdr *ehdr;
2659                 skb_reset_mac_header(skb);
2660                 ehdr = eth_hdr(skb);
2661                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2662                         err = -EMSGSIZE;
2663                         goto out_free;
2664                 }
2665         }
2666
2667         skb->protocol = proto;
2668         skb->dev = dev;
2669         skb->priority = sk->sk_priority;
2670         skb->mark = sk->sk_mark;
2671
2672         packet_pick_tx_queue(dev, skb);
2673
2674         if (po->has_vnet_hdr) {
2675                 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2676                         u16 s = __virtio16_to_cpu(false, vnet_hdr.csum_start);
2677                         u16 o = __virtio16_to_cpu(false, vnet_hdr.csum_offset);
2678                         if (!skb_partial_csum_set(skb, s, o)) {
2679                                 err = -EINVAL;
2680                                 goto out_free;
2681                         }
2682                 }
2683
2684                 skb_shinfo(skb)->gso_size =
2685                         __virtio16_to_cpu(false, vnet_hdr.gso_size);
2686                 skb_shinfo(skb)->gso_type = gso_type;
2687
2688                 /* Header must be checked, and gso_segs computed. */
2689                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2690                 skb_shinfo(skb)->gso_segs = 0;
2691
2692                 len += vnet_hdr_len;
2693         }
2694
2695         if (!packet_use_direct_xmit(po))
2696                 skb_probe_transport_header(skb, reserve);
2697         if (unlikely(extra_len == 4))
2698                 skb->no_fcs = 1;
2699
2700         err = po->xmit(skb);
2701         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2702                 goto out_unlock;
2703
2704         dev_put(dev);
2705
2706         return len;
2707
2708 out_free:
2709         kfree_skb(skb);
2710 out_unlock:
2711         if (dev)
2712                 dev_put(dev);
2713 out:
2714         return err;
2715 }
2716
2717 static int packet_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
2718 {
2719         struct sock *sk = sock->sk;
2720         struct packet_sock *po = pkt_sk(sk);
2721
2722         if (po->tx_ring.pg_vec)
2723                 return tpacket_snd(po, msg);
2724         else
2725                 return packet_snd(sock, msg, len);
2726 }
2727
2728 /*
2729  *      Close a PACKET socket. This is fairly simple. We immediately go
2730  *      to 'closed' state and remove our protocol entry in the device list.
2731  */
2732
2733 static int packet_release(struct socket *sock)
2734 {
2735         struct sock *sk = sock->sk;
2736         struct packet_sock *po;
2737         struct net *net;
2738         union tpacket_req_u req_u;
2739
2740         if (!sk)
2741                 return 0;
2742
2743         net = sock_net(sk);
2744         po = pkt_sk(sk);
2745
2746         mutex_lock(&net->packet.sklist_lock);
2747         sk_del_node_init_rcu(sk);
2748         mutex_unlock(&net->packet.sklist_lock);
2749
2750         preempt_disable();
2751         sock_prot_inuse_add(net, sk->sk_prot, -1);
2752         preempt_enable();
2753
2754         spin_lock(&po->bind_lock);
2755         unregister_prot_hook(sk, false);
2756         packet_cached_dev_reset(po);
2757
2758         if (po->prot_hook.dev) {
2759                 dev_put(po->prot_hook.dev);
2760                 po->prot_hook.dev = NULL;
2761         }
2762         spin_unlock(&po->bind_lock);
2763
2764         packet_flush_mclist(sk);
2765
2766         if (po->rx_ring.pg_vec) {
2767                 memset(&req_u, 0, sizeof(req_u));
2768                 packet_set_ring(sk, &req_u, 1, 0);
2769         }
2770
2771         if (po->tx_ring.pg_vec) {
2772                 memset(&req_u, 0, sizeof(req_u));
2773                 packet_set_ring(sk, &req_u, 1, 1);
2774         }
2775
2776         fanout_release(sk);
2777
2778         synchronize_net();
2779         /*
2780          *      Now the socket is dead. No more input will appear.
2781          */
2782         sock_orphan(sk);
2783         sock->sk = NULL;
2784
2785         /* Purge queues */
2786
2787         skb_queue_purge(&sk->sk_receive_queue);
2788         packet_free_pending(po);
2789         sk_refcnt_debug_release(sk);
2790
2791         sock_put(sk);
2792         return 0;
2793 }
2794
2795 /*
2796  *      Attach a packet hook.
2797  */
2798
2799 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 proto)
2800 {
2801         struct packet_sock *po = pkt_sk(sk);
2802         const struct net_device *dev_curr;
2803         __be16 proto_curr;
2804         bool need_rehook;
2805
2806         if (po->fanout) {
2807                 if (dev)
2808                         dev_put(dev);
2809
2810                 return -EINVAL;
2811         }
2812
2813         lock_sock(sk);
2814         spin_lock(&po->bind_lock);
2815
2816         proto_curr = po->prot_hook.type;
2817         dev_curr = po->prot_hook.dev;
2818
2819         need_rehook = proto_curr != proto || dev_curr != dev;
2820
2821         if (need_rehook) {
2822                 unregister_prot_hook(sk, true);
2823
2824                 po->num = proto;
2825                 po->prot_hook.type = proto;
2826
2827                 if (po->prot_hook.dev)
2828                         dev_put(po->prot_hook.dev);
2829
2830                 po->prot_hook.dev = dev;
2831
2832                 po->ifindex = dev ? dev->ifindex : 0;
2833                 packet_cached_dev_assign(po, dev);
2834         }
2835
2836         if (proto == 0 || !need_rehook)
2837                 goto out_unlock;
2838
2839         if (!dev || (dev->flags & IFF_UP)) {
2840                 register_prot_hook(sk);
2841         } else {
2842                 sk->sk_err = ENETDOWN;
2843                 if (!sock_flag(sk, SOCK_DEAD))
2844                         sk->sk_error_report(sk);
2845         }
2846
2847 out_unlock:
2848         spin_unlock(&po->bind_lock);
2849         release_sock(sk);
2850         return 0;
2851 }
2852
2853 /*
2854  *      Bind a packet socket to a device
2855  */
2856
2857 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2858                             int addr_len)
2859 {
2860         struct sock *sk = sock->sk;
2861         char name[15];
2862         struct net_device *dev;
2863         int err = -ENODEV;
2864
2865         /*
2866          *      Check legality
2867          */
2868
2869         if (addr_len != sizeof(struct sockaddr))
2870                 return -EINVAL;
2871         strlcpy(name, uaddr->sa_data, sizeof(name));
2872
2873         dev = dev_get_by_name(sock_net(sk), name);
2874         if (dev)
2875                 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2876         return err;
2877 }
2878
2879 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2880 {
2881         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2882         struct sock *sk = sock->sk;
2883         struct net_device *dev = NULL;
2884         int err;
2885
2886
2887         /*
2888          *      Check legality
2889          */
2890
2891         if (addr_len < sizeof(struct sockaddr_ll))
2892                 return -EINVAL;
2893         if (sll->sll_family != AF_PACKET)
2894                 return -EINVAL;
2895
2896         if (sll->sll_ifindex) {
2897                 err = -ENODEV;
2898                 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2899                 if (dev == NULL)
2900                         goto out;
2901         }
2902         err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2903
2904 out:
2905         return err;
2906 }
2907
2908 static struct proto packet_proto = {
2909         .name     = "PACKET",
2910         .owner    = THIS_MODULE,
2911         .obj_size = sizeof(struct packet_sock),
2912 };
2913
2914 /*
2915  *      Create a packet of type SOCK_PACKET.
2916  */
2917
2918 static int packet_create(struct net *net, struct socket *sock, int protocol,
2919                          int kern)
2920 {
2921         struct sock *sk;
2922         struct packet_sock *po;
2923         __be16 proto = (__force __be16)protocol; /* weird, but documented */
2924         int err;
2925
2926         if (!ns_capable(net->user_ns, CAP_NET_RAW))
2927                 return -EPERM;
2928         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2929             sock->type != SOCK_PACKET)
2930                 return -ESOCKTNOSUPPORT;
2931
2932         sock->state = SS_UNCONNECTED;
2933
2934         err = -ENOBUFS;
2935         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto, kern);
2936         if (sk == NULL)
2937                 goto out;
2938
2939         sock->ops = &packet_ops;
2940         if (sock->type == SOCK_PACKET)
2941                 sock->ops = &packet_ops_spkt;
2942
2943         sock_init_data(sock, sk);
2944
2945         po = pkt_sk(sk);
2946         sk->sk_family = PF_PACKET;
2947         po->num = proto;
2948         po->xmit = dev_queue_xmit;
2949
2950         err = packet_alloc_pending(po);
2951         if (err)
2952                 goto out2;
2953
2954         packet_cached_dev_reset(po);
2955
2956         sk->sk_destruct = packet_sock_destruct;
2957         sk_refcnt_debug_inc(sk);
2958
2959         /*
2960          *      Attach a protocol block
2961          */
2962
2963         spin_lock_init(&po->bind_lock);
2964         mutex_init(&po->pg_vec_lock);
2965         po->rollover = NULL;
2966         po->prot_hook.func = packet_rcv;
2967
2968         if (sock->type == SOCK_PACKET)
2969                 po->prot_hook.func = packet_rcv_spkt;
2970
2971         po->prot_hook.af_packet_priv = sk;
2972
2973         if (proto) {
2974                 po->prot_hook.type = proto;
2975                 register_prot_hook(sk);
2976         }
2977
2978         mutex_lock(&net->packet.sklist_lock);
2979         sk_add_node_rcu(sk, &net->packet.sklist);
2980         mutex_unlock(&net->packet.sklist_lock);
2981
2982         preempt_disable();
2983         sock_prot_inuse_add(net, &packet_proto, 1);
2984         preempt_enable();
2985
2986         return 0;
2987 out2:
2988         sk_free(sk);
2989 out:
2990         return err;
2991 }
2992
2993 /*
2994  *      Pull a packet from our receive queue and hand it to the user.
2995  *      If necessary we block.
2996  */
2997
2998 static int packet_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
2999                           int flags)
3000 {
3001         struct sock *sk = sock->sk;
3002         struct sk_buff *skb;
3003         int copied, err;
3004         int vnet_hdr_len = 0;
3005         unsigned int origlen = 0;
3006
3007         err = -EINVAL;
3008         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
3009                 goto out;
3010
3011 #if 0
3012         /* What error should we return now? EUNATTACH? */
3013         if (pkt_sk(sk)->ifindex < 0)
3014                 return -ENODEV;
3015 #endif
3016
3017         if (flags & MSG_ERRQUEUE) {
3018                 err = sock_recv_errqueue(sk, msg, len,
3019                                          SOL_PACKET, PACKET_TX_TIMESTAMP);
3020                 goto out;
3021         }
3022
3023         /*
3024          *      Call the generic datagram receiver. This handles all sorts
3025          *      of horrible races and re-entrancy so we can forget about it
3026          *      in the protocol layers.
3027          *
3028          *      Now it will return ENETDOWN, if device have just gone down,
3029          *      but then it will block.
3030          */
3031
3032         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
3033
3034         /*
3035          *      An error occurred so return it. Because skb_recv_datagram()
3036          *      handles the blocking we don't see and worry about blocking
3037          *      retries.
3038          */
3039
3040         if (skb == NULL)
3041                 goto out;
3042
3043         if (pkt_sk(sk)->pressure)
3044                 packet_rcv_has_room(pkt_sk(sk), NULL);
3045
3046         if (pkt_sk(sk)->has_vnet_hdr) {
3047                 struct virtio_net_hdr vnet_hdr = { 0 };
3048
3049                 err = -EINVAL;
3050                 vnet_hdr_len = sizeof(vnet_hdr);
3051                 if (len < vnet_hdr_len)
3052                         goto out_free;
3053
3054                 len -= vnet_hdr_len;
3055
3056                 if (skb_is_gso(skb)) {
3057                         struct skb_shared_info *sinfo = skb_shinfo(skb);
3058
3059                         /* This is a hint as to how much should be linear. */
3060                         vnet_hdr.hdr_len =
3061                                 __cpu_to_virtio16(false, skb_headlen(skb));
3062                         vnet_hdr.gso_size =
3063                                 __cpu_to_virtio16(false, sinfo->gso_size);
3064                         if (sinfo->gso_type & SKB_GSO_TCPV4)
3065                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
3066                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
3067                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
3068                         else if (sinfo->gso_type & SKB_GSO_UDP)
3069                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
3070                         else if (sinfo->gso_type & SKB_GSO_FCOE)
3071                                 goto out_free;
3072                         else
3073                                 BUG();
3074                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
3075                                 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
3076                 } else
3077                         vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
3078
3079                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
3080                         vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
3081                         vnet_hdr.csum_start = __cpu_to_virtio16(false,
3082                                           skb_checksum_start_offset(skb));
3083                         vnet_hdr.csum_offset = __cpu_to_virtio16(false,
3084                                                          skb->csum_offset);
3085                 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
3086                         vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
3087                 } /* else everything is zero */
3088
3089                 err = memcpy_to_msg(msg, (void *)&vnet_hdr, vnet_hdr_len);
3090                 if (err < 0)
3091                         goto out_free;
3092         }
3093
3094         /* You lose any data beyond the buffer you gave. If it worries
3095          * a user program they can ask the device for its MTU
3096          * anyway.
3097          */
3098         copied = skb->len;
3099         if (copied > len) {
3100                 copied = len;
3101                 msg->msg_flags |= MSG_TRUNC;
3102         }
3103
3104         err = skb_copy_datagram_msg(skb, 0, msg, copied);
3105         if (err)
3106                 goto out_free;
3107
3108         if (sock->type != SOCK_PACKET) {
3109                 struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3110
3111                 /* Original length was stored in sockaddr_ll fields */
3112                 origlen = PACKET_SKB_CB(skb)->sa.origlen;
3113                 sll->sll_family = AF_PACKET;
3114                 sll->sll_protocol = skb->protocol;
3115         }
3116
3117         sock_recv_ts_and_drops(msg, sk, skb);
3118
3119         if (msg->msg_name) {
3120                 /* If the address length field is there to be filled
3121                  * in, we fill it in now.
3122                  */
3123                 if (sock->type == SOCK_PACKET) {
3124                         __sockaddr_check_size(sizeof(struct sockaddr_pkt));
3125                         msg->msg_namelen = sizeof(struct sockaddr_pkt);
3126                 } else {
3127                         struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
3128
3129                         msg->msg_namelen = sll->sll_halen +
3130                                 offsetof(struct sockaddr_ll, sll_addr);
3131                 }
3132                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
3133                        msg->msg_namelen);
3134         }
3135
3136         if (pkt_sk(sk)->auxdata) {
3137                 struct tpacket_auxdata aux;
3138
3139                 aux.tp_status = TP_STATUS_USER;
3140                 if (skb->ip_summed == CHECKSUM_PARTIAL)
3141                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
3142                 else if (skb->pkt_type != PACKET_OUTGOING &&
3143                          (skb->ip_summed == CHECKSUM_COMPLETE ||
3144                           skb_csum_unnecessary(skb)))
3145                         aux.tp_status |= TP_STATUS_CSUM_VALID;
3146
3147                 aux.tp_len = origlen;
3148                 aux.tp_snaplen = skb->len;
3149                 aux.tp_mac = 0;
3150                 aux.tp_net = skb_network_offset(skb);
3151                 if (skb_vlan_tag_present(skb)) {
3152                         aux.tp_vlan_tci = skb_vlan_tag_get(skb);
3153                         aux.tp_vlan_tpid = ntohs(skb->vlan_proto);
3154                         aux.tp_status |= TP_STATUS_VLAN_VALID | TP_STATUS_VLAN_TPID_VALID;
3155                 } else {
3156                         aux.tp_vlan_tci = 0;
3157                         aux.tp_vlan_tpid = 0;
3158                 }
3159                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
3160         }
3161
3162         /*
3163          *      Free or return the buffer as appropriate. Again this
3164          *      hides all the races and re-entrancy issues from us.
3165          */
3166         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
3167
3168 out_free:
3169         skb_free_datagram(sk, skb);
3170 out:
3171         return err;
3172 }
3173
3174 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
3175                                int *uaddr_len, int peer)
3176 {
3177         struct net_device *dev;
3178         struct sock *sk = sock->sk;
3179
3180         if (peer)
3181                 return -EOPNOTSUPP;
3182
3183         uaddr->sa_family = AF_PACKET;
3184         memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
3185         rcu_read_lock();
3186         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
3187         if (dev)
3188                 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
3189         rcu_read_unlock();
3190         *uaddr_len = sizeof(*uaddr);
3191
3192         return 0;
3193 }
3194
3195 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
3196                           int *uaddr_len, int peer)
3197 {
3198         struct net_device *dev;
3199         struct sock *sk = sock->sk;
3200         struct packet_sock *po = pkt_sk(sk);
3201         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
3202
3203         if (peer)
3204                 return -EOPNOTSUPP;
3205
3206         sll->sll_family = AF_PACKET;
3207         sll->sll_ifindex = po->ifindex;
3208         sll->sll_protocol = po->num;
3209         sll->sll_pkttype = 0;
3210         rcu_read_lock();
3211         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
3212         if (dev) {
3213                 sll->sll_hatype = dev->type;
3214                 sll->sll_halen = dev->addr_len;
3215                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
3216         } else {
3217                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
3218                 sll->sll_halen = 0;
3219         }
3220         rcu_read_unlock();
3221         *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
3222
3223         return 0;
3224 }
3225
3226 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
3227                          int what)
3228 {
3229         switch (i->type) {
3230         case PACKET_MR_MULTICAST:
3231                 if (i->alen != dev->addr_len)
3232                         return -EINVAL;
3233                 if (what > 0)
3234                         return dev_mc_add(dev, i->addr);
3235                 else
3236                         return dev_mc_del(dev, i->addr);
3237                 break;
3238         case PACKET_MR_PROMISC:
3239                 return dev_set_promiscuity(dev, what);
3240         case PACKET_MR_ALLMULTI:
3241                 return dev_set_allmulti(dev, what);
3242         case PACKET_MR_UNICAST:
3243                 if (i->alen != dev->addr_len)
3244                         return -EINVAL;
3245                 if (what > 0)
3246                         return dev_uc_add(dev, i->addr);
3247                 else
3248                         return dev_uc_del(dev, i->addr);
3249                 break;
3250         default:
3251                 break;
3252         }
3253         return 0;
3254 }
3255
3256 static void packet_dev_mclist_delete(struct net_device *dev,
3257                                      struct packet_mclist **mlp)
3258 {
3259         struct packet_mclist *ml;
3260
3261         while ((ml = *mlp) != NULL) {
3262                 if (ml->ifindex == dev->ifindex) {
3263                         packet_dev_mc(dev, ml, -1);
3264                         *mlp = ml->next;
3265                         kfree(ml);
3266                 } else
3267                         mlp = &ml->next;
3268         }
3269 }
3270
3271 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
3272 {
3273         struct packet_sock *po = pkt_sk(sk);
3274         struct packet_mclist *ml, *i;
3275         struct net_device *dev;
3276         int err;
3277
3278         rtnl_lock();
3279
3280         err = -ENODEV;
3281         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
3282         if (!dev)
3283                 goto done;
3284
3285         err = -EINVAL;
3286         if (mreq->mr_alen > dev->addr_len)
3287                 goto done;
3288
3289         err = -ENOBUFS;
3290         i = kmalloc(sizeof(*i), GFP_KERNEL);
3291         if (i == NULL)
3292                 goto done;
3293
3294         err = 0;
3295         for (ml = po->mclist; ml; ml = ml->next) {
3296                 if (ml->ifindex == mreq->mr_ifindex &&
3297                     ml->type == mreq->mr_type &&
3298                     ml->alen == mreq->mr_alen &&
3299                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3300                         ml->count++;
3301                         /* Free the new element ... */
3302                         kfree(i);
3303                         goto done;
3304                 }
3305         }
3306
3307         i->type = mreq->mr_type;
3308         i->ifindex = mreq->mr_ifindex;
3309         i->alen = mreq->mr_alen;
3310         memcpy(i->addr, mreq->mr_address, i->alen);
3311         i->count = 1;
3312         i->next = po->mclist;
3313         po->mclist = i;
3314         err = packet_dev_mc(dev, i, 1);
3315         if (err) {
3316                 po->mclist = i->next;
3317                 kfree(i);
3318         }
3319
3320 done:
3321         rtnl_unlock();
3322         return err;
3323 }
3324
3325 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3326 {
3327         struct packet_mclist *ml, **mlp;
3328
3329         rtnl_lock();
3330
3331         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3332                 if (ml->ifindex == mreq->mr_ifindex &&
3333                     ml->type == mreq->mr_type &&
3334                     ml->alen == mreq->mr_alen &&
3335                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3336                         if (--ml->count == 0) {
3337                                 struct net_device *dev;
3338                                 *mlp = ml->next;
3339                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3340                                 if (dev)
3341                                         packet_dev_mc(dev, ml, -1);
3342                                 kfree(ml);
3343                         }
3344                         break;
3345                 }
3346         }
3347         rtnl_unlock();
3348         return 0;
3349 }
3350
3351 static void packet_flush_mclist(struct sock *sk)
3352 {
3353         struct packet_sock *po = pkt_sk(sk);
3354         struct packet_mclist *ml;
3355
3356         if (!po->mclist)
3357                 return;
3358
3359         rtnl_lock();
3360         while ((ml = po->mclist) != NULL) {
3361                 struct net_device *dev;
3362
3363                 po->mclist = ml->next;
3364                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3365                 if (dev != NULL)
3366                         packet_dev_mc(dev, ml, -1);
3367                 kfree(ml);
3368         }
3369         rtnl_unlock();
3370 }
3371
3372 static int
3373 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3374 {
3375         struct sock *sk = sock->sk;
3376         struct packet_sock *po = pkt_sk(sk);
3377         int ret;
3378
3379         if (level != SOL_PACKET)
3380                 return -ENOPROTOOPT;
3381
3382         switch (optname) {
3383         case PACKET_ADD_MEMBERSHIP:
3384         case PACKET_DROP_MEMBERSHIP:
3385         {
3386                 struct packet_mreq_max mreq;
3387                 int len = optlen;
3388                 memset(&mreq, 0, sizeof(mreq));
3389                 if (len < sizeof(struct packet_mreq))
3390                         return -EINVAL;
3391                 if (len > sizeof(mreq))
3392                         len = sizeof(mreq);
3393                 if (copy_from_user(&mreq, optval, len))
3394                         return -EFAULT;
3395                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3396                         return -EINVAL;
3397                 if (optname == PACKET_ADD_MEMBERSHIP)
3398                         ret = packet_mc_add(sk, &mreq);
3399                 else
3400                         ret = packet_mc_drop(sk, &mreq);
3401                 return ret;
3402         }
3403
3404         case PACKET_RX_RING:
3405         case PACKET_TX_RING:
3406         {
3407                 union tpacket_req_u req_u;
3408                 int len;
3409
3410                 switch (po->tp_version) {
3411                 case TPACKET_V1:
3412                 case TPACKET_V2:
3413                         len = sizeof(req_u.req);
3414                         break;
3415                 case TPACKET_V3:
3416                 default:
3417                         len = sizeof(req_u.req3);
3418                         break;
3419                 }
3420                 if (optlen < len)
3421                         return -EINVAL;
3422                 if (pkt_sk(sk)->has_vnet_hdr)
3423                         return -EINVAL;
3424                 if (copy_from_user(&req_u.req, optval, len))
3425                         return -EFAULT;
3426                 return packet_set_ring(sk, &req_u, 0,
3427                         optname == PACKET_TX_RING);
3428         }
3429         case PACKET_COPY_THRESH:
3430         {
3431                 int val;
3432
3433                 if (optlen != sizeof(val))
3434                         return -EINVAL;
3435                 if (copy_from_user(&val, optval, sizeof(val)))
3436                         return -EFAULT;
3437
3438                 pkt_sk(sk)->copy_thresh = val;
3439                 return 0;
3440         }
3441         case PACKET_VERSION:
3442         {
3443                 int val;
3444
3445                 if (optlen != sizeof(val))
3446                         return -EINVAL;
3447                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3448                         return -EBUSY;
3449                 if (copy_from_user(&val, optval, sizeof(val)))
3450                         return -EFAULT;
3451                 switch (val) {
3452                 case TPACKET_V1:
3453                 case TPACKET_V2:
3454                 case TPACKET_V3:
3455                         po->tp_version = val;
3456                         return 0;
3457                 default:
3458                         return -EINVAL;
3459                 }
3460         }
3461         case PACKET_RESERVE:
3462         {
3463                 unsigned int val;
3464
3465                 if (optlen != sizeof(val))
3466                         return -EINVAL;
3467                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3468                         return -EBUSY;
3469                 if (copy_from_user(&val, optval, sizeof(val)))
3470                         return -EFAULT;
3471                 po->tp_reserve = val;
3472                 return 0;
3473         }
3474         case PACKET_LOSS:
3475         {
3476                 unsigned int val;
3477
3478                 if (optlen != sizeof(val))
3479                         return -EINVAL;
3480                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3481                         return -EBUSY;
3482                 if (copy_from_user(&val, optval, sizeof(val)))
3483                         return -EFAULT;
3484                 po->tp_loss = !!val;
3485                 return 0;
3486         }
3487         case PACKET_AUXDATA:
3488         {
3489                 int val;
3490
3491                 if (optlen < sizeof(val))
3492                         return -EINVAL;
3493                 if (copy_from_user(&val, optval, sizeof(val)))
3494                         return -EFAULT;
3495
3496                 po->auxdata = !!val;
3497                 return 0;
3498         }
3499         case PACKET_ORIGDEV:
3500         {
3501                 int val;
3502
3503                 if (optlen < sizeof(val))
3504                         return -EINVAL;
3505                 if (copy_from_user(&val, optval, sizeof(val)))
3506                         return -EFAULT;
3507
3508                 po->origdev = !!val;
3509                 return 0;
3510         }
3511         case PACKET_VNET_HDR:
3512         {
3513                 int val;
3514
3515                 if (sock->type != SOCK_RAW)
3516                         return -EINVAL;
3517                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3518                         return -EBUSY;
3519                 if (optlen < sizeof(val))
3520                         return -EINVAL;
3521                 if (copy_from_user(&val, optval, sizeof(val)))
3522                         return -EFAULT;
3523
3524                 po->has_vnet_hdr = !!val;
3525                 return 0;
3526         }
3527         case PACKET_TIMESTAMP:
3528         {
3529                 int val;
3530
3531                 if (optlen != sizeof(val))
3532                         return -EINVAL;
3533                 if (copy_from_user(&val, optval, sizeof(val)))
3534                         return -EFAULT;
3535
3536                 po->tp_tstamp = val;
3537                 return 0;
3538         }
3539         case PACKET_FANOUT:
3540         {
3541                 int val;
3542
3543                 if (optlen != sizeof(val))
3544                         return -EINVAL;
3545                 if (copy_from_user(&val, optval, sizeof(val)))
3546                         return -EFAULT;
3547
3548                 return fanout_add(sk, val & 0xffff, val >> 16);
3549         }
3550         case PACKET_TX_HAS_OFF:
3551         {
3552                 unsigned int val;
3553
3554                 if (optlen != sizeof(val))
3555                         return -EINVAL;
3556                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3557                         return -EBUSY;
3558                 if (copy_from_user(&val, optval, sizeof(val)))
3559                         return -EFAULT;
3560                 po->tp_tx_has_off = !!val;
3561                 return 0;
3562         }
3563         case PACKET_QDISC_BYPASS:
3564         {
3565                 int val;
3566
3567                 if (optlen != sizeof(val))
3568                         return -EINVAL;
3569                 if (copy_from_user(&val, optval, sizeof(val)))
3570                         return -EFAULT;
3571
3572                 po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
3573                 return 0;
3574         }
3575         default:
3576                 return -ENOPROTOOPT;
3577         }
3578 }
3579
3580 static int packet_getsockopt(struct socket *sock, int level, int optname,
3581                              char __user *optval, int __user *optlen)
3582 {
3583         int len;
3584         int val, lv = sizeof(val);
3585         struct sock *sk = sock->sk;
3586         struct packet_sock *po = pkt_sk(sk);
3587         void *data = &val;
3588         union tpacket_stats_u st;
3589         struct tpacket_rollover_stats rstats;
3590
3591         if (level != SOL_PACKET)
3592                 return -ENOPROTOOPT;
3593
3594         if (get_user(len, optlen))
3595                 return -EFAULT;
3596
3597         if (len < 0)
3598                 return -EINVAL;
3599
3600         switch (optname) {
3601         case PACKET_STATISTICS:
3602                 spin_lock_bh(&sk->sk_receive_queue.lock);
3603                 memcpy(&st, &po->stats, sizeof(st));
3604                 memset(&po->stats, 0, sizeof(po->stats));
3605                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3606
3607                 if (po->tp_version == TPACKET_V3) {
3608                         lv = sizeof(struct tpacket_stats_v3);
3609                         st.stats3.tp_packets += st.stats3.tp_drops;
3610                         data = &st.stats3;
3611                 } else {
3612                         lv = sizeof(struct tpacket_stats);
3613                         st.stats1.tp_packets += st.stats1.tp_drops;
3614                         data = &st.stats1;
3615                 }
3616
3617                 break;
3618         case PACKET_AUXDATA:
3619                 val = po->auxdata;
3620                 break;
3621         case PACKET_ORIGDEV:
3622                 val = po->origdev;
3623                 break;
3624         case PACKET_VNET_HDR:
3625                 val = po->has_vnet_hdr;
3626                 break;
3627         case PACKET_VERSION:
3628                 val = po->tp_version;
3629                 break;
3630         case PACKET_HDRLEN:
3631                 if (len > sizeof(int))
3632                         len = sizeof(int);
3633                 if (copy_from_user(&val, optval, len))
3634                         return -EFAULT;
3635                 switch (val) {
3636                 case TPACKET_V1:
3637                         val = sizeof(struct tpacket_hdr);
3638                         break;
3639                 case TPACKET_V2:
3640                         val = sizeof(struct tpacket2_hdr);
3641                         break;
3642                 case TPACKET_V3:
3643                         val = sizeof(struct tpacket3_hdr);
3644                         break;
3645                 default:
3646                         return -EINVAL;
3647                 }
3648                 break;
3649         case PACKET_RESERVE:
3650                 val = po->tp_reserve;
3651                 break;
3652         case PACKET_LOSS:
3653                 val = po->tp_loss;
3654                 break;
3655         case PACKET_TIMESTAMP:
3656                 val = po->tp_tstamp;
3657                 break;
3658         case PACKET_FANOUT:
3659                 val = (po->fanout ?
3660                        ((u32)po->fanout->id |
3661                         ((u32)po->fanout->type << 16) |
3662                         ((u32)po->fanout->flags << 24)) :
3663                        0);
3664                 break;
3665         case PACKET_ROLLOVER_STATS:
3666                 if (!po->rollover)
3667                         return -EINVAL;
3668                 rstats.tp_all = atomic_long_read(&po->rollover->num);
3669                 rstats.tp_huge = atomic_long_read(&po->rollover->num_huge);
3670                 rstats.tp_failed = atomic_long_read(&po->rollover->num_failed);
3671                 data = &rstats;
3672                 lv = sizeof(rstats);
3673                 break;
3674         case PACKET_TX_HAS_OFF:
3675                 val = po->tp_tx_has_off;
3676                 break;
3677         case PACKET_QDISC_BYPASS:
3678                 val = packet_use_direct_xmit(po);
3679                 break;
3680         default:
3681                 return -ENOPROTOOPT;
3682         }
3683
3684         if (len > lv)
3685                 len = lv;
3686         if (put_user(len, optlen))
3687                 return -EFAULT;
3688         if (copy_to_user(optval, data, len))
3689                 return -EFAULT;
3690         return 0;
3691 }
3692
3693
3694 static int packet_notifier(struct notifier_block *this,
3695                            unsigned long msg, void *ptr)
3696 {
3697         struct sock *sk;
3698         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
3699         struct net *net = dev_net(dev);
3700
3701         rcu_read_lock();
3702         sk_for_each_rcu(sk, &net->packet.sklist) {
3703                 struct packet_sock *po = pkt_sk(sk);
3704
3705                 switch (msg) {
3706                 case NETDEV_UNREGISTER:
3707                         if (po->mclist)
3708                                 packet_dev_mclist_delete(dev, &po->mclist);
3709                         /* fallthrough */
3710
3711                 case NETDEV_DOWN:
3712                         if (dev->ifindex == po->ifindex) {
3713                                 spin_lock(&po->bind_lock);
3714                                 if (po->running) {
3715                                         __unregister_prot_hook(sk, false);
3716                                         sk->sk_err = ENETDOWN;
3717                                         if (!sock_flag(sk, SOCK_DEAD))
3718                                                 sk->sk_error_report(sk);
3719                                 }
3720                                 if (msg == NETDEV_UNREGISTER) {
3721                                         packet_cached_dev_reset(po);
3722                                         po->ifindex = -1;
3723                                         if (po->prot_hook.dev)
3724                                                 dev_put(po->prot_hook.dev);
3725                                         po->prot_hook.dev = NULL;
3726                                 }
3727                                 spin_unlock(&po->bind_lock);
3728                         }
3729                         break;
3730                 case NETDEV_UP:
3731                         if (dev->ifindex == po->ifindex) {
3732                                 spin_lock(&po->bind_lock);
3733                                 if (po->num)
3734                                         register_prot_hook(sk);
3735                                 spin_unlock(&po->bind_lock);
3736                         }
3737                         break;
3738                 }
3739         }
3740         rcu_read_unlock();
3741         return NOTIFY_DONE;
3742 }
3743
3744
3745 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3746                         unsigned long arg)
3747 {
3748         struct sock *sk = sock->sk;
3749
3750         switch (cmd) {
3751         case SIOCOUTQ:
3752         {
3753                 int amount = sk_wmem_alloc_get(sk);
3754
3755                 return put_user(amount, (int __user *)arg);
3756         }
3757         case SIOCINQ:
3758         {
3759                 struct sk_buff *skb;
3760                 int amount = 0;
3761
3762                 spin_lock_bh(&sk->sk_receive_queue.lock);
3763                 skb = skb_peek(&sk->sk_receive_queue);
3764                 if (skb)
3765                         amount = skb->len;
3766                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3767                 return put_user(amount, (int __user *)arg);
3768         }
3769         case SIOCGSTAMP:
3770                 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3771         case SIOCGSTAMPNS:
3772                 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3773
3774 #ifdef CONFIG_INET
3775         case SIOCADDRT:
3776         case SIOCDELRT:
3777         case SIOCDARP:
3778         case SIOCGARP:
3779         case SIOCSARP:
3780         case SIOCGIFADDR:
3781         case SIOCSIFADDR:
3782         case SIOCGIFBRDADDR:
3783         case SIOCSIFBRDADDR:
3784         case SIOCGIFNETMASK:
3785         case SIOCSIFNETMASK:
3786         case SIOCGIFDSTADDR:
3787         case SIOCSIFDSTADDR:
3788         case SIOCSIFFLAGS:
3789                 return inet_dgram_ops.ioctl(sock, cmd, arg);
3790 #endif
3791
3792         default:
3793                 return -ENOIOCTLCMD;
3794         }
3795         return 0;
3796 }
3797
3798 static unsigned int packet_poll(struct file *file, struct socket *sock,
3799                                 poll_table *wait)
3800 {
3801         struct sock *sk = sock->sk;
3802         struct packet_sock *po = pkt_sk(sk);
3803         unsigned int mask = datagram_poll(file, sock, wait);
3804
3805         spin_lock_bh(&sk->sk_receive_queue.lock);
3806         if (po->rx_ring.pg_vec) {
3807                 if (!packet_previous_rx_frame(po, &po->rx_ring,
3808                         TP_STATUS_KERNEL))
3809                         mask |= POLLIN | POLLRDNORM;
3810         }
3811         if (po->pressure && __packet_rcv_has_room(po, NULL) == ROOM_NORMAL)
3812                 po->pressure = 0;
3813         spin_unlock_bh(&sk->sk_receive_queue.lock);
3814         spin_lock_bh(&sk->sk_write_queue.lock);
3815         if (po->tx_ring.pg_vec) {
3816                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3817                         mask |= POLLOUT | POLLWRNORM;
3818         }
3819         spin_unlock_bh(&sk->sk_write_queue.lock);
3820         return mask;
3821 }
3822
3823
3824 /* Dirty? Well, I still did not learn better way to account
3825  * for user mmaps.
3826  */
3827
3828 static void packet_mm_open(struct vm_area_struct *vma)
3829 {
3830         struct file *file = vma->vm_file;
3831         struct socket *sock = file->private_data;
3832         struct sock *sk = sock->sk;
3833
3834         if (sk)
3835                 atomic_inc(&pkt_sk(sk)->mapped);
3836 }
3837
3838 static void packet_mm_close(struct vm_area_struct *vma)
3839 {
3840         struct file *file = vma->vm_file;
3841         struct socket *sock = file->private_data;
3842         struct sock *sk = sock->sk;
3843
3844         if (sk)
3845                 atomic_dec(&pkt_sk(sk)->mapped);
3846 }
3847
3848 static const struct vm_operations_struct packet_mmap_ops = {
3849         .open   =       packet_mm_open,
3850         .close  =       packet_mm_close,
3851 };
3852
3853 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3854                         unsigned int len)
3855 {
3856         int i;
3857
3858         for (i = 0; i < len; i++) {
3859                 if (likely(pg_vec[i].buffer)) {
3860                         if (is_vmalloc_addr(pg_vec[i].buffer))
3861                                 vfree(pg_vec[i].buffer);
3862                         else
3863                                 free_pages((unsigned long)pg_vec[i].buffer,
3864                                            order);
3865                         pg_vec[i].buffer = NULL;
3866                 }
3867         }
3868         kfree(pg_vec);
3869 }
3870
3871 static char *alloc_one_pg_vec_page(unsigned long order)
3872 {
3873         char *buffer;
3874         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3875                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3876
3877         buffer = (char *) __get_free_pages(gfp_flags, order);
3878         if (buffer)
3879                 return buffer;
3880
3881         /* __get_free_pages failed, fall back to vmalloc */
3882         buffer = vzalloc((1 << order) * PAGE_SIZE);
3883         if (buffer)
3884                 return buffer;
3885
3886         /* vmalloc failed, lets dig into swap here */
3887         gfp_flags &= ~__GFP_NORETRY;
3888         buffer = (char *) __get_free_pages(gfp_flags, order);
3889         if (buffer)
3890                 return buffer;
3891
3892         /* complete and utter failure */
3893         return NULL;
3894 }
3895
3896 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3897 {
3898         unsigned int block_nr = req->tp_block_nr;
3899         struct pgv *pg_vec;
3900         int i;
3901
3902         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3903         if (unlikely(!pg_vec))
3904                 goto out;
3905
3906         for (i = 0; i < block_nr; i++) {
3907                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3908                 if (unlikely(!pg_vec[i].buffer))
3909                         goto out_free_pgvec;
3910         }
3911
3912 out:
3913         return pg_vec;
3914
3915 out_free_pgvec:
3916         free_pg_vec(pg_vec, order, block_nr);
3917         pg_vec = NULL;
3918         goto out;
3919 }
3920
3921 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3922                 int closing, int tx_ring)
3923 {
3924         struct pgv *pg_vec = NULL;
3925         struct packet_sock *po = pkt_sk(sk);
3926         int was_running, order = 0;
3927         struct packet_ring_buffer *rb;
3928         struct sk_buff_head *rb_queue;
3929         __be16 num;
3930         int err = -EINVAL;
3931         /* Added to avoid minimal code churn */
3932         struct tpacket_req *req = &req_u->req;
3933
3934         /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3935         if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3936                 WARN(1, "Tx-ring is not supported.\n");
3937                 goto out;
3938         }
3939
3940         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3941         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3942
3943         err = -EBUSY;
3944         if (!closing) {
3945                 if (atomic_read(&po->mapped))
3946                         goto out;
3947                 if (packet_read_pending(rb))
3948                         goto out;
3949         }
3950
3951         if (req->tp_block_nr) {
3952                 /* Sanity tests and some calculations */
3953                 err = -EBUSY;
3954                 if (unlikely(rb->pg_vec))
3955                         goto out;
3956
3957                 switch (po->tp_version) {
3958                 case TPACKET_V1:
3959                         po->tp_hdrlen = TPACKET_HDRLEN;
3960                         break;
3961                 case TPACKET_V2:
3962                         po->tp_hdrlen = TPACKET2_HDRLEN;
3963                         break;
3964                 case TPACKET_V3:
3965                         po->tp_hdrlen = TPACKET3_HDRLEN;
3966                         break;
3967                 }
3968
3969                 err = -EINVAL;
3970                 if (unlikely((int)req->tp_block_size <= 0))
3971                         goto out;
3972                 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3973                         goto out;
3974                 if (po->tp_version >= TPACKET_V3 &&
3975                     (int)(req->tp_block_size -
3976                           BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
3977                         goto out;
3978                 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3979                                         po->tp_reserve))
3980                         goto out;
3981                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3982                         goto out;
3983
3984                 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3985                 if (unlikely(rb->frames_per_block <= 0))
3986                         goto out;
3987                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3988                                         req->tp_frame_nr))
3989                         goto out;
3990
3991                 err = -ENOMEM;
3992                 order = get_order(req->tp_block_size);
3993                 pg_vec = alloc_pg_vec(req, order);
3994                 if (unlikely(!pg_vec))
3995                         goto out;
3996                 switch (po->tp_version) {
3997                 case TPACKET_V3:
3998                 /* Transmit path is not supported. We checked
3999                  * it above but just being paranoid
4000                  */
4001                         if (!tx_ring)
4002                                 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
4003                         break;
4004                 default:
4005                         break;
4006                 }
4007         }
4008         /* Done */
4009         else {
4010                 err = -EINVAL;
4011                 if (unlikely(req->tp_frame_nr))
4012                         goto out;
4013         }
4014
4015         lock_sock(sk);
4016
4017         /* Detach socket from network */
4018         spin_lock(&po->bind_lock);
4019         was_running = po->running;
4020         num = po->num;
4021         if (was_running) {
4022                 po->num = 0;
4023                 __unregister_prot_hook(sk, false);
4024         }
4025         spin_unlock(&po->bind_lock);
4026
4027         synchronize_net();
4028
4029         err = -EBUSY;
4030         mutex_lock(&po->pg_vec_lock);
4031         if (closing || atomic_read(&po->mapped) == 0) {
4032                 err = 0;
4033                 spin_lock_bh(&rb_queue->lock);
4034                 swap(rb->pg_vec, pg_vec);
4035                 rb->frame_max = (req->tp_frame_nr - 1);
4036                 rb->head = 0;
4037                 rb->frame_size = req->tp_frame_size;
4038                 spin_unlock_bh(&rb_queue->lock);
4039
4040                 swap(rb->pg_vec_order, order);
4041                 swap(rb->pg_vec_len, req->tp_block_nr);
4042
4043                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
4044                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
4045                                                 tpacket_rcv : packet_rcv;
4046                 skb_queue_purge(rb_queue);
4047                 if (atomic_read(&po->mapped))
4048                         pr_err("packet_mmap: vma is busy: %d\n",
4049                                atomic_read(&po->mapped));
4050         }
4051         mutex_unlock(&po->pg_vec_lock);
4052
4053         spin_lock(&po->bind_lock);
4054         if (was_running) {
4055                 po->num = num;
4056                 register_prot_hook(sk);
4057         }
4058         spin_unlock(&po->bind_lock);
4059         if (closing && (po->tp_version > TPACKET_V2)) {
4060                 /* Because we don't support block-based V3 on tx-ring */
4061                 if (!tx_ring)
4062                         prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
4063         }
4064         release_sock(sk);
4065
4066         if (pg_vec)
4067                 free_pg_vec(pg_vec, order, req->tp_block_nr);
4068 out:
4069         return err;
4070 }
4071
4072 static int packet_mmap(struct file *file, struct socket *sock,
4073                 struct vm_area_struct *vma)
4074 {
4075         struct sock *sk = sock->sk;
4076         struct packet_sock *po = pkt_sk(sk);
4077         unsigned long size, expected_size;
4078         struct packet_ring_buffer *rb;
4079         unsigned long start;
4080         int err = -EINVAL;
4081         int i;
4082
4083         if (vma->vm_pgoff)
4084                 return -EINVAL;
4085
4086         mutex_lock(&po->pg_vec_lock);
4087
4088         expected_size = 0;
4089         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4090                 if (rb->pg_vec) {
4091                         expected_size += rb->pg_vec_len
4092                                                 * rb->pg_vec_pages
4093                                                 * PAGE_SIZE;
4094                 }
4095         }
4096
4097         if (expected_size == 0)
4098                 goto out;
4099
4100         size = vma->vm_end - vma->vm_start;
4101         if (size != expected_size)
4102                 goto out;
4103
4104         start = vma->vm_start;
4105         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
4106                 if (rb->pg_vec == NULL)
4107                         continue;
4108
4109                 for (i = 0; i < rb->pg_vec_len; i++) {
4110                         struct page *page;
4111                         void *kaddr = rb->pg_vec[i].buffer;
4112                         int pg_num;
4113
4114                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
4115                                 page = pgv_to_page(kaddr);
4116                                 err = vm_insert_page(vma, start, page);
4117                                 if (unlikely(err))
4118                                         goto out;
4119                                 start += PAGE_SIZE;
4120                                 kaddr += PAGE_SIZE;
4121                         }
4122                 }
4123         }
4124
4125         atomic_inc(&po->mapped);
4126         vma->vm_ops = &packet_mmap_ops;
4127         err = 0;
4128
4129 out:
4130         mutex_unlock(&po->pg_vec_lock);
4131         return err;
4132 }
4133
4134 static const struct proto_ops packet_ops_spkt = {
4135         .family =       PF_PACKET,
4136         .owner =        THIS_MODULE,
4137         .release =      packet_release,
4138         .bind =         packet_bind_spkt,
4139         .connect =      sock_no_connect,
4140         .socketpair =   sock_no_socketpair,
4141         .accept =       sock_no_accept,
4142         .getname =      packet_getname_spkt,
4143         .poll =         datagram_poll,
4144         .ioctl =        packet_ioctl,
4145         .listen =       sock_no_listen,
4146         .shutdown =     sock_no_shutdown,
4147         .setsockopt =   sock_no_setsockopt,
4148         .getsockopt =   sock_no_getsockopt,
4149         .sendmsg =      packet_sendmsg_spkt,
4150         .recvmsg =      packet_recvmsg,
4151         .mmap =         sock_no_mmap,
4152         .sendpage =     sock_no_sendpage,
4153 };
4154
4155 static const struct proto_ops packet_ops = {
4156         .family =       PF_PACKET,
4157         .owner =        THIS_MODULE,
4158         .release =      packet_release,
4159         .bind =         packet_bind,
4160         .connect =      sock_no_connect,
4161         .socketpair =   sock_no_socketpair,
4162         .accept =       sock_no_accept,
4163         .getname =      packet_getname,
4164         .poll =         packet_poll,
4165         .ioctl =        packet_ioctl,
4166         .listen =       sock_no_listen,
4167         .shutdown =     sock_no_shutdown,
4168         .setsockopt =   packet_setsockopt,
4169         .getsockopt =   packet_getsockopt,
4170         .sendmsg =      packet_sendmsg,
4171         .recvmsg =      packet_recvmsg,
4172         .mmap =         packet_mmap,
4173         .sendpage =     sock_no_sendpage,
4174 };
4175
4176 static const struct net_proto_family packet_family_ops = {
4177         .family =       PF_PACKET,
4178         .create =       packet_create,
4179         .owner  =       THIS_MODULE,
4180 };
4181
4182 static struct notifier_block packet_netdev_notifier = {
4183         .notifier_call =        packet_notifier,
4184 };
4185
4186 #ifdef CONFIG_PROC_FS
4187
4188 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
4189         __acquires(RCU)
4190 {
4191         struct net *net = seq_file_net(seq);
4192
4193         rcu_read_lock();
4194         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
4195 }
4196
4197 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
4198 {
4199         struct net *net = seq_file_net(seq);
4200         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
4201 }
4202
4203 static void packet_seq_stop(struct seq_file *seq, void *v)
4204         __releases(RCU)
4205 {
4206         rcu_read_unlock();
4207 }
4208
4209 static int packet_seq_show(struct seq_file *seq, void *v)
4210 {
4211         if (v == SEQ_START_TOKEN)
4212                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
4213         else {
4214                 struct sock *s = sk_entry(v);
4215                 const struct packet_sock *po = pkt_sk(s);
4216
4217                 seq_printf(seq,
4218                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
4219                            s,
4220                            atomic_read(&s->sk_refcnt),
4221                            s->sk_type,
4222                            ntohs(po->num),
4223                            po->ifindex,
4224                            po->running,
4225                            atomic_read(&s->sk_rmem_alloc),
4226                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
4227                            sock_i_ino(s));
4228         }
4229
4230         return 0;
4231 }
4232
4233 static const struct seq_operations packet_seq_ops = {
4234         .start  = packet_seq_start,
4235         .next   = packet_seq_next,
4236         .stop   = packet_seq_stop,
4237         .show   = packet_seq_show,
4238 };
4239
4240 static int packet_seq_open(struct inode *inode, struct file *file)
4241 {
4242         return seq_open_net(inode, file, &packet_seq_ops,
4243                             sizeof(struct seq_net_private));
4244 }
4245
4246 static const struct file_operations packet_seq_fops = {
4247         .owner          = THIS_MODULE,
4248         .open           = packet_seq_open,
4249         .read           = seq_read,
4250         .llseek         = seq_lseek,
4251         .release        = seq_release_net,
4252 };
4253
4254 #endif
4255
4256 static int __net_init packet_net_init(struct net *net)
4257 {
4258         mutex_init(&net->packet.sklist_lock);
4259         INIT_HLIST_HEAD(&net->packet.sklist);
4260
4261         if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
4262                 return -ENOMEM;
4263
4264         return 0;
4265 }
4266
4267 static void __net_exit packet_net_exit(struct net *net)
4268 {
4269         remove_proc_entry("packet", net->proc_net);
4270 }
4271
4272 static struct pernet_operations packet_net_ops = {
4273         .init = packet_net_init,
4274         .exit = packet_net_exit,
4275 };
4276
4277
4278 static void __exit packet_exit(void)
4279 {
4280         unregister_netdevice_notifier(&packet_netdev_notifier);
4281         unregister_pernet_subsys(&packet_net_ops);
4282         sock_unregister(PF_PACKET);
4283         proto_unregister(&packet_proto);
4284 }
4285
4286 static int __init packet_init(void)
4287 {
4288         int rc = proto_register(&packet_proto, 0);
4289
4290         if (rc != 0)
4291                 goto out;
4292
4293         sock_register(&packet_family_ops);
4294         register_pernet_subsys(&packet_net_ops);
4295         register_netdevice_notifier(&packet_netdev_notifier);
4296 out:
4297         return rc;
4298 }
4299
4300 module_init(packet_init);
4301 module_exit(packet_exit);
4302 MODULE_LICENSE("GPL");
4303 MODULE_ALIAS_NETPROTO(PF_PACKET);