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
  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         unsigned int origlen;
 220         union {
 221                 struct sockaddr_pkt pkt;
 222                 struct sockaddr_ll ll;
 223         } sa;
 224 };
 225
 226 #define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
 227
 228 #define GET_PBDQC_FROM_RB(x)    ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
 229 #define GET_PBLOCK_DESC(x, bid) \
 230         ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
 231 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x)       \
 232         ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
 233 #define GET_NEXT_PRB_BLK_NUM(x) \
 234         (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
 235         ((x)->kactive_blk_num+1) : 0)
 236
 237 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
 238 static void __fanout_link(struct sock *sk, struct packet_sock *po);
 239
 240 static struct net_device *packet_cached_dev_get(struct packet_sock *po)
 241 {
 242         struct net_device *dev;
 243
 244         rcu_read_lock();
 245         dev = rcu_dereference(po->cached_dev);
 246         if (likely(dev))
 247                 dev_hold(dev);
 248         rcu_read_unlock();
 249
 250         return dev;
 251 }
 252
 253 static void packet_cached_dev_assign(struct packet_sock *po,
 254                                      struct net_device *dev)
 255 {
 256         rcu_assign_pointer(po->cached_dev, dev);
 257 }
 258
 259 static void packet_cached_dev_reset(struct packet_sock *po)
 260 {
 261         RCU_INIT_POINTER(po->cached_dev, NULL);
 262 }
 263
 264 /* register_prot_hook must be invoked with the po->bind_lock held,
 265  * or from a context in which asynchronous accesses to the packet
 266  * socket is not possible (packet_create()).
 267  */
 268 static void register_prot_hook(struct sock *sk)
 269 {
 270         struct packet_sock *po = pkt_sk(sk);
 271
 272         if (!po->running) {
 273                 if (po->fanout)
 274                         __fanout_link(sk, po);
 275                 else
 276                         dev_add_pack(&po->prot_hook);
 277
 278                 sock_hold(sk);
 279                 po->running = 1;
 280         }
 281 }
 282
 283 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
 284  * held.   If the sync parameter is true, we will temporarily drop
 285  * the po->bind_lock and do a synchronize_net to make sure no
 286  * asynchronous packet processing paths still refer to the elements
 287  * of po->prot_hook.  If the sync parameter is false, it is the
 288  * callers responsibility to take care of this.
 289  */
 290 static void __unregister_prot_hook(struct sock *sk, bool sync)
 291 {
 292         struct packet_sock *po = pkt_sk(sk);
 293
 294         po->running = 0;
 295
 296         if (po->fanout)
 297                 __fanout_unlink(sk, po);
 298         else
 299                 __dev_remove_pack(&po->prot_hook);
 300
 301         __sock_put(sk);
 302
 303         if (sync) {
 304                 spin_unlock(&po->bind_lock);
 305                 synchronize_net();
 306                 spin_lock(&po->bind_lock);
 307         }
 308 }
 309
 310 static void unregister_prot_hook(struct sock *sk, bool sync)
 311 {
 312         struct packet_sock *po = pkt_sk(sk);
 313
 314         if (po->running)
 315                 __unregister_prot_hook(sk, sync);
 316 }
 317
 318 static inline __pure struct page *pgv_to_page(void *addr)
 319 {
 320         if (is_vmalloc_addr(addr))
 321                 return vmalloc_to_page(addr);
 322         return virt_to_page(addr);
 323 }
 324
 325 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
 326 {
 327         union tpacket_uhdr h;
 328
 329         h.raw = frame;
 330         switch (po->tp_version) {
 331         case TPACKET_V1:
 332                 h.h1->tp_status = status;
 333                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 334                 break;
 335         case TPACKET_V2:
 336                 h.h2->tp_status = status;
 337                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 338                 break;
 339         case TPACKET_V3:
 340         default:
 341                 WARN(1, "TPACKET version not supported.\n");
 342                 BUG();
 343         }
 344
 345         smp_wmb();
 346 }
 347
 348 static int __packet_get_status(struct packet_sock *po, void *frame)
 349 {
 350         union tpacket_uhdr h;
 351
 352         smp_rmb();
 353
 354         h.raw = frame;
 355         switch (po->tp_version) {
 356         case TPACKET_V1:
 357                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 358                 return h.h1->tp_status;
 359         case TPACKET_V2:
 360                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 361                 return h.h2->tp_status;
 362         case TPACKET_V3:
 363         default:
 364                 WARN(1, "TPACKET version not supported.\n");
 365                 BUG();
 366                 return 0;
 367         }
 368 }
 369
 370 static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
 371                                    unsigned int flags)
 372 {
 373         struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
 374
 375         if (shhwtstamps) {
 376                 if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) &&
 377                     ktime_to_timespec_cond(shhwtstamps->syststamp, ts))
 378                         return TP_STATUS_TS_SYS_HARDWARE;
 379                 if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
 380                     ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
 381                         return TP_STATUS_TS_RAW_HARDWARE;
 382         }
 383
 384         if (ktime_to_timespec_cond(skb->tstamp, ts))
 385                 return TP_STATUS_TS_SOFTWARE;
 386
 387         return 0;
 388 }
 389
 390 static __u32 __packet_set_timestamp(struct packet_sock *po, void *frame,
 391                                     struct sk_buff *skb)
 392 {
 393         union tpacket_uhdr h;
 394         struct timespec ts;
 395         __u32 ts_status;
 396
 397         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
 398                 return 0;
 399
 400         h.raw = frame;
 401         switch (po->tp_version) {
 402         case TPACKET_V1:
 403                 h.h1->tp_sec = ts.tv_sec;
 404                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
 405                 break;
 406         case TPACKET_V2:
 407                 h.h2->tp_sec = ts.tv_sec;
 408                 h.h2->tp_nsec = ts.tv_nsec;
 409                 break;
 410         case TPACKET_V3:
 411         default:
 412                 WARN(1, "TPACKET version not supported.\n");
 413                 BUG();
 414         }
 415
 416         /* one flush is safe, as both fields always lie on the same cacheline */
 417         flush_dcache_page(pgv_to_page(&h.h1->tp_sec));
 418         smp_wmb();
 419
 420         return ts_status;
 421 }
 422
 423 static void *packet_lookup_frame(struct packet_sock *po,
 424                 struct packet_ring_buffer *rb,
 425                 unsigned int position,
 426                 int status)
 427 {
 428         unsigned int pg_vec_pos, frame_offset;
 429         union tpacket_uhdr h;
 430
 431         pg_vec_pos = position / rb->frames_per_block;
 432         frame_offset = position % rb->frames_per_block;
 433
 434         h.raw = rb->pg_vec[pg_vec_pos].buffer +
 435                 (frame_offset * rb->frame_size);
 436
 437         if (status != __packet_get_status(po, h.raw))
 438                 return NULL;
 439
 440         return h.raw;
 441 }
 442
 443 static void *packet_current_frame(struct packet_sock *po,
 444                 struct packet_ring_buffer *rb,
 445                 int status)
 446 {
 447         return packet_lookup_frame(po, rb, rb->head, status);
 448 }
 449
 450 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 451 {
 452         del_timer_sync(&pkc->retire_blk_timer);
 453 }
 454
 455 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
 456                 int tx_ring,
 457                 struct sk_buff_head *rb_queue)
 458 {
 459         struct tpacket_kbdq_core *pkc;
 460
 461         pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
 462
 463         spin_lock_bh(&rb_queue->lock);
 464         pkc->delete_blk_timer = 1;
 465         spin_unlock_bh(&rb_queue->lock);
 466
 467         prb_del_retire_blk_timer(pkc);
 468 }
 469
 470 static void prb_init_blk_timer(struct packet_sock *po,
 471                 struct tpacket_kbdq_core *pkc,
 472                 void (*func) (unsigned long))
 473 {
 474         init_timer(&pkc->retire_blk_timer);
 475         pkc->retire_blk_timer.data = (long)po;
 476         pkc->retire_blk_timer.function = func;
 477         pkc->retire_blk_timer.expires = jiffies;
 478 }
 479
 480 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
 481 {
 482         struct tpacket_kbdq_core *pkc;
 483
 484         if (tx_ring)
 485                 BUG();
 486
 487         pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
 488         prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
 489 }
 490
 491 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
 492                                 int blk_size_in_bytes)
 493 {
 494         struct net_device *dev;
 495         unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
 496         struct ethtool_cmd ecmd;
 497         int err;
 498         u32 speed;
 499
 500         rtnl_lock();
 501         dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
 502         if (unlikely(!dev)) {
 503                 rtnl_unlock();
 504                 return DEFAULT_PRB_RETIRE_TOV;
 505         }
 506         err = __ethtool_get_settings(dev, &ecmd);
 507         speed = ethtool_cmd_speed(&ecmd);
 508         rtnl_unlock();
 509         if (!err) {
 510                 /*
 511                  * If the link speed is so slow you don't really
 512                  * need to worry about perf anyways
 513                  */
 514                 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
 515                         return DEFAULT_PRB_RETIRE_TOV;
 516                 } else {
 517                         msec = 1;
 518                         div = speed / 1000;
 519                 }
 520         }
 521
 522         mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
 523
 524         if (div)
 525                 mbits /= div;
 526
 527         tmo = mbits * msec;
 528
 529         if (div)
 530                 return tmo+1;
 531         return tmo;
 532 }
 533
 534 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
 535                         union tpacket_req_u *req_u)
 536 {
 537         p1->feature_req_word = req_u->req3.tp_feature_req_word;
 538 }
 539
 540 static void init_prb_bdqc(struct packet_sock *po,
 541                         struct packet_ring_buffer *rb,
 542                         struct pgv *pg_vec,
 543                         union tpacket_req_u *req_u, int tx_ring)
 544 {
 545         struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
 546         struct tpacket_block_desc *pbd;
 547
 548         memset(p1, 0x0, sizeof(*p1));
 549
 550         p1->knxt_seq_num = 1;
 551         p1->pkbdq = pg_vec;
 552         pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
 553         p1->pkblk_start = pg_vec[0].buffer;
 554         p1->kblk_size = req_u->req3.tp_block_size;
 555         p1->knum_blocks = req_u->req3.tp_block_nr;
 556         p1->hdrlen = po->tp_hdrlen;
 557         p1->version = po->tp_version;
 558         p1->last_kactive_blk_num = 0;
 559         po->stats.stats3.tp_freeze_q_cnt = 0;
 560         if (req_u->req3.tp_retire_blk_tov)
 561                 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
 562         else
 563                 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
 564                                                 req_u->req3.tp_block_size);
 565         p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
 566         p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
 567
 568         p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
 569         prb_init_ft_ops(p1, req_u);
 570         prb_setup_retire_blk_timer(po, tx_ring);
 571         prb_open_block(p1, pbd);
 572 }
 573
 574 /*  Do NOT update the last_blk_num first.
 575  *  Assumes sk_buff_head lock is held.
 576  */
 577 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 578 {
 579         mod_timer(&pkc->retire_blk_timer,
 580                         jiffies + pkc->tov_in_jiffies);
 581         pkc->last_kactive_blk_num = pkc->kactive_blk_num;
 582 }
 583
 584 /*
 585  * Timer logic:
 586  * 1) We refresh the timer only when we open a block.
 587  *    By doing this we don't waste cycles refreshing the timer
 588  *        on packet-by-packet basis.
 589  *
 590  * With a 1MB block-size, on a 1Gbps line, it will take
 591  * i) ~8 ms to fill a block + ii) memcpy etc.
 592  * In this cut we are not accounting for the memcpy time.
 593  *
 594  * So, if the user sets the 'tmo' to 10ms then the timer
 595  * will never fire while the block is still getting filled
 596  * (which is what we want). However, the user could choose
 597  * to close a block early and that's fine.
 598  *
 599  * But when the timer does fire, we check whether or not to refresh it.
 600  * Since the tmo granularity is in msecs, it is not too expensive
 601  * to refresh the timer, lets say every '8' msecs.
 602  * Either the user can set the 'tmo' or we can derive it based on
 603  * a) line-speed and b) block-size.
 604  * prb_calc_retire_blk_tmo() calculates the tmo.
 605  *
 606  */
 607 static void prb_retire_rx_blk_timer_expired(unsigned long data)
 608 {
 609         struct packet_sock *po = (struct packet_sock *)data;
 610         struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
 611         unsigned int frozen;
 612         struct tpacket_block_desc *pbd;
 613
 614         spin_lock(&po->sk.sk_receive_queue.lock);
 615
 616         frozen = prb_queue_frozen(pkc);
 617         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 618
 619         if (unlikely(pkc->delete_blk_timer))
 620                 goto out;
 621
 622         /* We only need to plug the race when the block is partially filled.
 623          * tpacket_rcv:
 624          *              lock(); increment BLOCK_NUM_PKTS; unlock()
 625          *              copy_bits() is in progress ...
 626          *              timer fires on other cpu:
 627          *              we can't retire the current block because copy_bits
 628          *              is in progress.
 629          *
 630          */
 631         if (BLOCK_NUM_PKTS(pbd)) {
 632                 while (atomic_read(&pkc->blk_fill_in_prog)) {
 633                         /* Waiting for skb_copy_bits to finish... */
 634                         cpu_relax();
 635                 }
 636         }
 637
 638         if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
 639                 if (!frozen) {
 640                         prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
 641                         if (!prb_dispatch_next_block(pkc, po))
 642                                 goto refresh_timer;
 643                         else
 644                                 goto out;
 645                 } else {
 646                         /* Case 1. Queue was frozen because user-space was
 647                          *         lagging behind.
 648                          */
 649                         if (prb_curr_blk_in_use(pkc, pbd)) {
 650                                 /*
 651                                  * Ok, user-space is still behind.
 652                                  * So just refresh the timer.
 653                                  */
 654                                 goto refresh_timer;
 655                         } else {
 656                                /* Case 2. queue was frozen,user-space caught up,
 657                                 * now the link went idle && the timer fired.
 658                                 * We don't have a block to close.So we open this
 659                                 * block and restart the timer.
 660                                 * opening a block thaws the queue,restarts timer
 661                                 * Thawing/timer-refresh is a side effect.
 662                                 */
 663                                 prb_open_block(pkc, pbd);
 664                                 goto out;
 665                         }
 666                 }
 667         }
 668
 669 refresh_timer:
 670         _prb_refresh_rx_retire_blk_timer(pkc);
 671
 672 out:
 673         spin_unlock(&po->sk.sk_receive_queue.lock);
 674 }
 675
 676 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
 677                 struct tpacket_block_desc *pbd1, __u32 status)
 678 {
 679         /* Flush everything minus the block header */
 680
 681 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 682         u8 *start, *end;
 683
 684         start = (u8 *)pbd1;
 685
 686         /* Skip the block header(we know header WILL fit in 4K) */
 687         start += PAGE_SIZE;
 688
 689         end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
 690         for (; start < end; start += PAGE_SIZE)
 691                 flush_dcache_page(pgv_to_page(start));
 692
 693         smp_wmb();
 694 #endif
 695
 696         /* Now update the block status. */
 697
 698         BLOCK_STATUS(pbd1) = status;
 699
 700         /* Flush the block header */
 701
 702 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 703         start = (u8 *)pbd1;
 704         flush_dcache_page(pgv_to_page(start));
 705
 706         smp_wmb();
 707 #endif
 708 }
 709
 710 /*
 711  * Side effect:
 712  *
 713  * 1) flush the block
 714  * 2) Increment active_blk_num
 715  *
 716  * Note:We DONT refresh the timer on purpose.
 717  *      Because almost always the next block will be opened.
 718  */
 719 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
 720                 struct tpacket_block_desc *pbd1,
 721                 struct packet_sock *po, unsigned int stat)
 722 {
 723         __u32 status = TP_STATUS_USER | stat;
 724
 725         struct tpacket3_hdr *last_pkt;
 726         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 727
 728         if (po->stats.stats3.tp_drops)
 729                 status |= TP_STATUS_LOSING;
 730
 731         last_pkt = (struct tpacket3_hdr *)pkc1->prev;
 732         last_pkt->tp_next_offset = 0;
 733
 734         /* Get the ts of the last pkt */
 735         if (BLOCK_NUM_PKTS(pbd1)) {
 736                 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
 737                 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
 738         } else {
 739                 /* Ok, we tmo'd - so get the current time */
 740                 struct timespec ts;
 741                 getnstimeofday(&ts);
 742                 h1->ts_last_pkt.ts_sec = ts.tv_sec;
 743                 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
 744         }
 745
 746         smp_wmb();
 747
 748         /* Flush the block */
 749         prb_flush_block(pkc1, pbd1, status);
 750
 751         pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
 752 }
 753
 754 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
 755 {
 756         pkc->reset_pending_on_curr_blk = 0;
 757 }
 758
 759 /*
 760  * Side effect of opening a block:
 761  *
 762  * 1) prb_queue is thawed.
 763  * 2) retire_blk_timer is refreshed.
 764  *
 765  */
 766 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
 767         struct tpacket_block_desc *pbd1)
 768 {
 769         struct timespec ts;
 770         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 771
 772         smp_rmb();
 773
 774         /* We could have just memset this but we will lose the
 775          * flexibility of making the priv area sticky
 776          */
 777
 778         BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
 779         BLOCK_NUM_PKTS(pbd1) = 0;
 780         BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 781
 782         getnstimeofday(&ts);
 783
 784         h1->ts_first_pkt.ts_sec = ts.tv_sec;
 785         h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
 786
 787         pkc1->pkblk_start = (char *)pbd1;
 788         pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 789
 790         BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 791         BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
 792
 793         pbd1->version = pkc1->version;
 794         pkc1->prev = pkc1->nxt_offset;
 795         pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
 796
 797         prb_thaw_queue(pkc1);
 798         _prb_refresh_rx_retire_blk_timer(pkc1);
 799
 800         smp_wmb();
 801 }
 802
 803 /*
 804  * Queue freeze logic:
 805  * 1) Assume tp_block_nr = 8 blocks.
 806  * 2) At time 't0', user opens Rx ring.
 807  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
 808  * 4) user-space is either sleeping or processing block '0'.
 809  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
 810  *    it will close block-7,loop around and try to fill block '0'.
 811  *    call-flow:
 812  *    __packet_lookup_frame_in_block
 813  *      prb_retire_current_block()
 814  *      prb_dispatch_next_block()
 815  *        |->(BLOCK_STATUS == USER) evaluates to true
 816  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
 817  * 6) Now there are two cases:
 818  *    6.1) Link goes idle right after the queue is frozen.
 819  *         But remember, the last open_block() refreshed the timer.
 820  *         When this timer expires,it will refresh itself so that we can
 821  *         re-open block-0 in near future.
 822  *    6.2) Link is busy and keeps on receiving packets. This is a simple
 823  *         case and __packet_lookup_frame_in_block will check if block-0
 824  *         is free and can now be re-used.
 825  */
 826 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
 827                                   struct packet_sock *po)
 828 {
 829         pkc->reset_pending_on_curr_blk = 1;
 830         po->stats.stats3.tp_freeze_q_cnt++;
 831 }
 832
 833 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
 834
 835 /*
 836  * If the next block is free then we will dispatch it
 837  * and return a good offset.
 838  * Else, we will freeze the queue.
 839  * So, caller must check the return value.
 840  */
 841 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
 842                 struct packet_sock *po)
 843 {
 844         struct tpacket_block_desc *pbd;
 845
 846         smp_rmb();
 847
 848         /* 1. Get current block num */
 849         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 850
 851         /* 2. If this block is currently in_use then freeze the queue */
 852         if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
 853                 prb_freeze_queue(pkc, po);
 854                 return NULL;
 855         }
 856
 857         /*
 858          * 3.
 859          * open this block and return the offset where the first packet
 860          * needs to get stored.
 861          */
 862         prb_open_block(pkc, pbd);
 863         return (void *)pkc->nxt_offset;
 864 }
 865
 866 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
 867                 struct packet_sock *po, unsigned int status)
 868 {
 869         struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 870
 871         /* retire/close the current block */
 872         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
 873                 /*
 874                  * Plug the case where copy_bits() is in progress on
 875                  * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
 876                  * have space to copy the pkt in the current block and
 877                  * called prb_retire_current_block()
 878                  *
 879                  * We don't need to worry about the TMO case because
 880                  * the timer-handler already handled this case.
 881                  */
 882                 if (!(status & TP_STATUS_BLK_TMO)) {
 883                         while (atomic_read(&pkc->blk_fill_in_prog)) {
 884                                 /* Waiting for skb_copy_bits to finish... */
 885                                 cpu_relax();
 886                         }
 887                 }
 888                 prb_close_block(pkc, pbd, po, status);
 889                 return;
 890         }
 891 }
 892
 893 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
 894                                       struct tpacket_block_desc *pbd)
 895 {
 896         return TP_STATUS_USER & BLOCK_STATUS(pbd);
 897 }
 898
 899 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
 900 {
 901         return pkc->reset_pending_on_curr_blk;
 902 }
 903
 904 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
 905 {
 906         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
 907         atomic_dec(&pkc->blk_fill_in_prog);
 908 }
 909
 910 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
 911                         struct tpacket3_hdr *ppd)
 912 {
 913         ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
 914 }
 915
 916 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
 917                         struct tpacket3_hdr *ppd)
 918 {
 919         ppd->hv1.tp_rxhash = 0;
 920 }
 921
 922 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
 923                         struct tpacket3_hdr *ppd)
 924 {
 925         if (vlan_tx_tag_present(pkc->skb)) {
 926                 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
 927                 ppd->tp_status = TP_STATUS_VLAN_VALID;
 928         } else {
 929                 ppd->hv1.tp_vlan_tci = 0;
 930                 ppd->tp_status = TP_STATUS_AVAILABLE;
 931         }
 932 }
 933
 934 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
 935                         struct tpacket3_hdr *ppd)
 936 {
 937         prb_fill_vlan_info(pkc, ppd);
 938
 939         if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
 940                 prb_fill_rxhash(pkc, ppd);
 941         else
 942                 prb_clear_rxhash(pkc, ppd);
 943 }
 944
 945 static void prb_fill_curr_block(char *curr,
 946                                 struct tpacket_kbdq_core *pkc,
 947                                 struct tpacket_block_desc *pbd,
 948                                 unsigned int len)
 949 {
 950         struct tpacket3_hdr *ppd;
 951
 952         ppd  = (struct tpacket3_hdr *)curr;
 953         ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
 954         pkc->prev = curr;
 955         pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
 956         BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
 957         BLOCK_NUM_PKTS(pbd) += 1;
 958         atomic_inc(&pkc->blk_fill_in_prog);
 959         prb_run_all_ft_ops(pkc, ppd);
 960 }
 961
 962 /* Assumes caller has the sk->rx_queue.lock */
 963 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
 964                                             struct sk_buff *skb,
 965                                                 int status,
 966                                             unsigned int len
 967                                             )
 968 {
 969         struct tpacket_kbdq_core *pkc;
 970         struct tpacket_block_desc *pbd;
 971         char *curr, *end;
 972
 973         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 974         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 975
 976         /* Queue is frozen when user space is lagging behind */
 977         if (prb_queue_frozen(pkc)) {
 978                 /*
 979                  * Check if that last block which caused the queue to freeze,
 980                  * is still in_use by user-space.
 981                  */
 982                 if (prb_curr_blk_in_use(pkc, pbd)) {
 983                         /* Can't record this packet */
 984                         return NULL;
 985                 } else {
 986                         /*
 987                          * Ok, the block was released by user-space.
 988                          * Now let's open that block.
 989                          * opening a block also thaws the queue.
 990                          * Thawing is a side effect.
 991                          */
 992                         prb_open_block(pkc, pbd);
 993                 }
 994         }
 995
 996         smp_mb();
 997         curr = pkc->nxt_offset;
 998         pkc->skb = skb;
 999         end = (char *)pbd + pkc->kblk_size;
1000
1001         /* first try the current block */
1002         if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1003                 prb_fill_curr_block(curr, pkc, pbd, len);
1004                 return (void *)curr;
1005         }
1006
1007         /* Ok, close the current block */
1008         prb_retire_current_block(pkc, po, 0);
1009
1010         /* Now, try to dispatch the next block */
1011         curr = (char *)prb_dispatch_next_block(pkc, po);
1012         if (curr) {
1013                 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1014                 prb_fill_curr_block(curr, pkc, pbd, len);
1015                 return (void *)curr;
1016         }
1017
1018         /*
1019          * No free blocks are available.user_space hasn't caught up yet.
1020          * Queue was just frozen and now this packet will get dropped.
1021          */
1022         return NULL;
1023 }
1024
1025 static void *packet_current_rx_frame(struct packet_sock *po,
1026                                             struct sk_buff *skb,
1027                                             int status, unsigned int len)
1028 {
1029         char *curr = NULL;
1030         switch (po->tp_version) {
1031         case TPACKET_V1:
1032         case TPACKET_V2:
1033                 curr = packet_lookup_frame(po, &po->rx_ring,
1034                                         po->rx_ring.head, status);
1035                 return curr;
1036         case TPACKET_V3:
1037                 return __packet_lookup_frame_in_block(po, skb, status, len);
1038         default:
1039                 WARN(1, "TPACKET version not supported\n");
1040                 BUG();
1041                 return NULL;
1042         }
1043 }
1044
1045 static void *prb_lookup_block(struct packet_sock *po,
1046                                      struct packet_ring_buffer *rb,
1047                                      unsigned int idx,
1048                                      int status)
1049 {
1050         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1051         struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
1052
1053         if (status != BLOCK_STATUS(pbd))
1054                 return NULL;
1055         return pbd;
1056 }
1057
1058 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1059 {
1060         unsigned int prev;
1061         if (rb->prb_bdqc.kactive_blk_num)
1062                 prev = rb->prb_bdqc.kactive_blk_num-1;
1063         else
1064                 prev = rb->prb_bdqc.knum_blocks-1;
1065         return prev;
1066 }
1067
1068 /* Assumes caller has held the rx_queue.lock */
1069 static void *__prb_previous_block(struct packet_sock *po,
1070                                          struct packet_ring_buffer *rb,
1071                                          int status)
1072 {
1073         unsigned int previous = prb_previous_blk_num(rb);
1074         return prb_lookup_block(po, rb, previous, status);
1075 }
1076
1077 static void *packet_previous_rx_frame(struct packet_sock *po,
1078                                              struct packet_ring_buffer *rb,
1079                                              int status)
1080 {
1081         if (po->tp_version <= TPACKET_V2)
1082                 return packet_previous_frame(po, rb, status);
1083
1084         return __prb_previous_block(po, rb, status);
1085 }
1086
1087 static void packet_increment_rx_head(struct packet_sock *po,
1088                                             struct packet_ring_buffer *rb)
1089 {
1090         switch (po->tp_version) {
1091         case TPACKET_V1:
1092         case TPACKET_V2:
1093                 return packet_increment_head(rb);
1094         case TPACKET_V3:
1095         default:
1096                 WARN(1, "TPACKET version not supported.\n");
1097                 BUG();
1098                 return;
1099         }
1100 }
1101
1102 static void *packet_previous_frame(struct packet_sock *po,
1103                 struct packet_ring_buffer *rb,
1104                 int status)
1105 {
1106         unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1107         return packet_lookup_frame(po, rb, previous, status);
1108 }
1109
1110 static void packet_increment_head(struct packet_ring_buffer *buff)
1111 {
1112         buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1113 }
1114
1115 static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
1116 {
1117         struct sock *sk = &po->sk;
1118         bool has_room;
1119
1120         if (po->prot_hook.func != tpacket_rcv)
1121                 return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize)
1122                         <= sk->sk_rcvbuf;
1123
1124         spin_lock(&sk->sk_receive_queue.lock);
1125         if (po->tp_version == TPACKET_V3)
1126                 has_room = prb_lookup_block(po, &po->rx_ring,
1127                                             po->rx_ring.prb_bdqc.kactive_blk_num,
1128                                             TP_STATUS_KERNEL);
1129         else
1130                 has_room = packet_lookup_frame(po, &po->rx_ring,
1131                                                po->rx_ring.head,
1132                                                TP_STATUS_KERNEL);
1133         spin_unlock(&sk->sk_receive_queue.lock);
1134
1135         return has_room;
1136 }
1137
1138 static void packet_sock_destruct(struct sock *sk)
1139 {
1140         skb_queue_purge(&sk->sk_error_queue);
1141
1142         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1143         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1144
1145         if (!sock_flag(sk, SOCK_DEAD)) {
1146                 pr_err("Attempt to release alive packet socket: %p\n", sk);
1147                 return;
1148         }
1149
1150         sk_refcnt_debug_dec(sk);
1151 }
1152
1153 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1154                                       struct sk_buff *skb,
1155                                       unsigned int num)
1156 {
1157         return (((u64)skb->rxhash) * num) >> 32;
1158 }
1159
1160 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1161                                     struct sk_buff *skb,
1162                                     unsigned int num)
1163 {
1164         unsigned int val = atomic_inc_return(&f->rr_cur);
1165
1166         return val % num;
1167 }
1168
1169 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1170                                      struct sk_buff *skb,
1171                                      unsigned int num)
1172 {
1173         return smp_processor_id() % num;
1174 }
1175
1176 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1177                                           struct sk_buff *skb,
1178                                           unsigned int idx, unsigned int skip,
1179                                           unsigned int num)
1180 {
1181         unsigned int i, j;
1182
1183         i = j = min_t(int, f->next[idx], num - 1);
1184         do {
1185                 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) {
1186                         if (i != j)
1187                                 f->next[idx] = i;
1188                         return i;
1189                 }
1190                 if (++i == num)
1191                         i = 0;
1192         } while (i != j);
1193
1194         return idx;
1195 }
1196
1197 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1198 {
1199         return f->flags & (flag >> 8);
1200 }
1201
1202 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1203                              struct packet_type *pt, struct net_device *orig_dev)
1204 {
1205         struct packet_fanout *f = pt->af_packet_priv;
1206         unsigned int num = ACCESS_ONCE(f->num_members);
1207         struct packet_sock *po;
1208         unsigned int idx;
1209
1210         if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1211             !num) {
1212                 kfree_skb(skb);
1213                 return 0;
1214         }
1215
1216         switch (f->type) {
1217         case PACKET_FANOUT_HASH:
1218         default:
1219                 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1220                         skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1221                         if (!skb)
1222                                 return 0;
1223                 }
1224                 skb_get_rxhash(skb);
1225                 idx = fanout_demux_hash(f, skb, num);
1226                 break;
1227         case PACKET_FANOUT_LB:
1228                 idx = fanout_demux_lb(f, skb, num);
1229                 break;
1230         case PACKET_FANOUT_CPU:
1231                 idx = fanout_demux_cpu(f, skb, num);
1232                 break;
1233         case PACKET_FANOUT_ROLLOVER:
1234                 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num);
1235                 break;
1236         }
1237
1238         po = pkt_sk(f->arr[idx]);
1239         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) &&
1240             unlikely(!packet_rcv_has_room(po, skb))) {
1241                 idx = fanout_demux_rollover(f, skb, idx, idx, num);
1242                 po = pkt_sk(f->arr[idx]);
1243         }
1244
1245         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1246 }
1247
1248 DEFINE_MUTEX(fanout_mutex);
1249 EXPORT_SYMBOL_GPL(fanout_mutex);
1250 static LIST_HEAD(fanout_list);
1251
1252 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1253 {
1254         struct packet_fanout *f = po->fanout;
1255
1256         spin_lock(&f->lock);
1257         f->arr[f->num_members] = sk;
1258         smp_wmb();
1259         f->num_members++;
1260         spin_unlock(&f->lock);
1261 }
1262
1263 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1264 {
1265         struct packet_fanout *f = po->fanout;
1266         int i;
1267
1268         spin_lock(&f->lock);
1269         for (i = 0; i < f->num_members; i++) {
1270                 if (f->arr[i] == sk)
1271                         break;
1272         }
1273         BUG_ON(i >= f->num_members);
1274         f->arr[i] = f->arr[f->num_members - 1];
1275         f->num_members--;
1276         spin_unlock(&f->lock);
1277 }
1278
1279 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk)
1280 {
1281         if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout)
1282                 return true;
1283
1284         return false;
1285 }
1286
1287 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1288 {
1289         struct packet_sock *po = pkt_sk(sk);
1290         struct packet_fanout *f, *match;
1291         u8 type = type_flags & 0xff;
1292         u8 flags = type_flags >> 8;
1293         int err;
1294
1295         switch (type) {
1296         case PACKET_FANOUT_ROLLOVER:
1297                 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1298                         return -EINVAL;
1299         case PACKET_FANOUT_HASH:
1300         case PACKET_FANOUT_LB:
1301         case PACKET_FANOUT_CPU:
1302                 break;
1303         default:
1304                 return -EINVAL;
1305         }
1306
1307         if (!po->running)
1308                 return -EINVAL;
1309
1310         if (po->fanout)
1311                 return -EALREADY;
1312
1313         mutex_lock(&fanout_mutex);
1314         match = NULL;
1315         list_for_each_entry(f, &fanout_list, list) {
1316                 if (f->id == id &&
1317                     read_pnet(&f->net) == sock_net(sk)) {
1318                         match = f;
1319                         break;
1320                 }
1321         }
1322         err = -EINVAL;
1323         if (match && match->flags != flags)
1324                 goto out;
1325         if (!match) {
1326                 err = -ENOMEM;
1327                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1328                 if (!match)
1329                         goto out;
1330                 write_pnet(&match->net, sock_net(sk));
1331                 match->id = id;
1332                 match->type = type;
1333                 match->flags = flags;
1334                 atomic_set(&match->rr_cur, 0);
1335                 INIT_LIST_HEAD(&match->list);
1336                 spin_lock_init(&match->lock);
1337                 atomic_set(&match->sk_ref, 0);
1338                 match->prot_hook.type = po->prot_hook.type;
1339                 match->prot_hook.dev = po->prot_hook.dev;
1340                 match->prot_hook.func = packet_rcv_fanout;
1341                 match->prot_hook.af_packet_priv = match;
1342                 match->prot_hook.id_match = match_fanout_group;
1343                 dev_add_pack(&match->prot_hook);
1344                 list_add(&match->list, &fanout_list);
1345         }
1346         err = -EINVAL;
1347         if (match->type == type &&
1348             match->prot_hook.type == po->prot_hook.type &&
1349             match->prot_hook.dev == po->prot_hook.dev) {
1350                 err = -ENOSPC;
1351                 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1352                         __dev_remove_pack(&po->prot_hook);
1353                         po->fanout = match;
1354                         atomic_inc(&match->sk_ref);
1355                         __fanout_link(sk, po);
1356                         err = 0;
1357                 }
1358         }
1359 out:
1360         mutex_unlock(&fanout_mutex);
1361         return err;
1362 }
1363
1364 static void fanout_release(struct sock *sk)
1365 {
1366         struct packet_sock *po = pkt_sk(sk);
1367         struct packet_fanout *f;
1368
1369         f = po->fanout;
1370         if (!f)
1371                 return;
1372
1373         mutex_lock(&fanout_mutex);
1374         po->fanout = NULL;
1375
1376         if (atomic_dec_and_test(&f->sk_ref)) {
1377                 list_del(&f->list);
1378                 dev_remove_pack(&f->prot_hook);
1379                 kfree(f);
1380         }
1381         mutex_unlock(&fanout_mutex);
1382 }
1383
1384 static const struct proto_ops packet_ops;
1385
1386 static const struct proto_ops packet_ops_spkt;
1387
1388 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1389                            struct packet_type *pt, struct net_device *orig_dev)
1390 {
1391         struct sock *sk;
1392         struct sockaddr_pkt *spkt;
1393
1394         /*
1395          *      When we registered the protocol we saved the socket in the data
1396          *      field for just this event.
1397          */
1398
1399         sk = pt->af_packet_priv;
1400
1401         /*
1402          *      Yank back the headers [hope the device set this
1403          *      right or kerboom...]
1404          *
1405          *      Incoming packets have ll header pulled,
1406          *      push it back.
1407          *
1408          *      For outgoing ones skb->data == skb_mac_header(skb)
1409          *      so that this procedure is noop.
1410          */
1411
1412         if (skb->pkt_type == PACKET_LOOPBACK)
1413                 goto out;
1414
1415         if (!net_eq(dev_net(dev), sock_net(sk)))
1416                 goto out;
1417
1418         skb = skb_share_check(skb, GFP_ATOMIC);
1419         if (skb == NULL)
1420                 goto oom;
1421
1422         /* drop any routing info */
1423         skb_dst_drop(skb);
1424
1425         /* drop conntrack reference */
1426         nf_reset(skb);
1427
1428         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1429
1430         skb_push(skb, skb->data - skb_mac_header(skb));
1431
1432         /*
1433          *      The SOCK_PACKET socket receives _all_ frames.
1434          */
1435
1436         spkt->spkt_family = dev->type;
1437         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1438         spkt->spkt_protocol = skb->protocol;
1439
1440         /*
1441          *      Charge the memory to the socket. This is done specifically
1442          *      to prevent sockets using all the memory up.
1443          */
1444
1445         if (sock_queue_rcv_skb(sk, skb) == 0)
1446                 return 0;
1447
1448 out:
1449         kfree_skb(skb);
1450 oom:
1451         return 0;
1452 }
1453
1454
1455 /*
1456  *      Output a raw packet to a device layer. This bypasses all the other
1457  *      protocol layers and you must therefore supply it with a complete frame
1458  */
1459
1460 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1461                                struct msghdr *msg, size_t len)
1462 {
1463         struct sock *sk = sock->sk;
1464         struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1465         struct sk_buff *skb = NULL;
1466         struct net_device *dev;
1467         __be16 proto = 0;
1468         int err;
1469         int extra_len = 0;
1470
1471         /*
1472          *      Get and verify the address.
1473          */
1474
1475         if (saddr) {
1476                 if (msg->msg_namelen < sizeof(struct sockaddr))
1477                         return -EINVAL;
1478                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1479                         proto = saddr->spkt_protocol;
1480         } else
1481                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1482
1483         /*
1484          *      Find the device first to size check it
1485          */
1486
1487         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1488 retry:
1489         rcu_read_lock();
1490         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1491         err = -ENODEV;
1492         if (dev == NULL)
1493                 goto out_unlock;
1494
1495         err = -ENETDOWN;
1496         if (!(dev->flags & IFF_UP))
1497                 goto out_unlock;
1498
1499         /*
1500          * You may not queue a frame bigger than the mtu. This is the lowest level
1501          * raw protocol and you must do your own fragmentation at this level.
1502          */
1503
1504         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1505                 if (!netif_supports_nofcs(dev)) {
1506                         err = -EPROTONOSUPPORT;
1507                         goto out_unlock;
1508                 }
1509                 extra_len = 4; /* We're doing our own CRC */
1510         }
1511
1512         err = -EMSGSIZE;
1513         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1514                 goto out_unlock;
1515
1516         if (!skb) {
1517                 size_t reserved = LL_RESERVED_SPACE(dev);
1518                 int tlen = dev->needed_tailroom;
1519                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1520
1521                 rcu_read_unlock();
1522                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1523                 if (skb == NULL)
1524                         return -ENOBUFS;
1525                 /* FIXME: Save some space for broken drivers that write a hard
1526                  * header at transmission time by themselves. PPP is the notable
1527                  * one here. This should really be fixed at the driver level.
1528                  */
1529                 skb_reserve(skb, reserved);
1530                 skb_reset_network_header(skb);
1531
1532                 /* Try to align data part correctly */
1533                 if (hhlen) {
1534                         skb->data -= hhlen;
1535                         skb->tail -= hhlen;
1536                         if (len < hhlen)
1537                                 skb_reset_network_header(skb);
1538                 }
1539                 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1540                 if (err)
1541                         goto out_free;
1542                 goto retry;
1543         }
1544
1545         if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1546                 /* Earlier code assumed this would be a VLAN pkt,
1547                  * double-check this now that we have the actual
1548                  * packet in hand.
1549                  */
1550                 struct ethhdr *ehdr;
1551                 skb_reset_mac_header(skb);
1552                 ehdr = eth_hdr(skb);
1553                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1554                         err = -EMSGSIZE;
1555                         goto out_unlock;
1556                 }
1557         }
1558
1559         skb->protocol = proto;
1560         skb->dev = dev;
1561         skb->priority = sk->sk_priority;
1562         skb->mark = sk->sk_mark;
1563
1564         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1565
1566         if (unlikely(extra_len == 4))
1567                 skb->no_fcs = 1;
1568
1569         skb_probe_transport_header(skb, 0);
1570
1571         dev_queue_xmit(skb);
1572         rcu_read_unlock();
1573         return len;
1574
1575 out_unlock:
1576         rcu_read_unlock();
1577 out_free:
1578         kfree_skb(skb);
1579         return err;
1580 }
1581
1582 static unsigned int run_filter(const struct sk_buff *skb,
1583                                       const struct sock *sk,
1584                                       unsigned int res)
1585 {
1586         struct sk_filter *filter;
1587
1588         rcu_read_lock();
1589         filter = rcu_dereference(sk->sk_filter);
1590         if (filter != NULL)
1591                 res = SK_RUN_FILTER(filter, skb);
1592         rcu_read_unlock();
1593
1594         return res;
1595 }
1596
1597 /*
1598  * This function makes lazy skb cloning in hope that most of packets
1599  * are discarded by BPF.
1600  *
1601  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1602  * and skb->cb are mangled. It works because (and until) packets
1603  * falling here are owned by current CPU. Output packets are cloned
1604  * by dev_queue_xmit_nit(), input packets are processed by net_bh
1605  * sequencially, so that if we return skb to original state on exit,
1606  * we will not harm anyone.
1607  */
1608
1609 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1610                       struct packet_type *pt, struct net_device *orig_dev)
1611 {
1612         struct sock *sk;
1613         struct sockaddr_ll *sll;
1614         struct packet_sock *po;
1615         u8 *skb_head = skb->data;
1616         int skb_len = skb->len;
1617         unsigned int snaplen, res;
1618
1619         if (skb->pkt_type == PACKET_LOOPBACK)
1620                 goto drop;
1621
1622         sk = pt->af_packet_priv;
1623         po = pkt_sk(sk);
1624
1625         if (!net_eq(dev_net(dev), sock_net(sk)))
1626                 goto drop;
1627
1628         skb->dev = dev;
1629
1630         if (dev->header_ops) {
1631                 /* The device has an explicit notion of ll header,
1632                  * exported to higher levels.
1633                  *
1634                  * Otherwise, the device hides details of its frame
1635                  * structure, so that corresponding packet head is
1636                  * never delivered to user.
1637                  */
1638                 if (sk->sk_type != SOCK_DGRAM)
1639                         skb_push(skb, skb->data - skb_mac_header(skb));
1640                 else if (skb->pkt_type == PACKET_OUTGOING) {
1641                         /* Special case: outgoing packets have ll header at head */
1642                         skb_pull(skb, skb_network_offset(skb));
1643                 }
1644         }
1645
1646         snaplen = skb->len;
1647
1648         res = run_filter(skb, sk, snaplen);
1649         if (!res)
1650                 goto drop_n_restore;
1651         if (snaplen > res)
1652                 snaplen = res;
1653
1654         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1655                 goto drop_n_acct;
1656
1657         if (skb_shared(skb)) {
1658                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1659                 if (nskb == NULL)
1660                         goto drop_n_acct;
1661
1662                 if (skb_head != skb->data) {
1663                         skb->data = skb_head;
1664                         skb->len = skb_len;
1665                 }
1666                 consume_skb(skb);
1667                 skb = nskb;
1668         }
1669
1670         BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1671                      sizeof(skb->cb));
1672
1673         sll = &PACKET_SKB_CB(skb)->sa.ll;
1674         sll->sll_family = AF_PACKET;
1675         sll->sll_hatype = dev->type;
1676         sll->sll_protocol = skb->protocol;
1677         sll->sll_pkttype = skb->pkt_type;
1678         if (unlikely(po->origdev))
1679                 sll->sll_ifindex = orig_dev->ifindex;
1680         else
1681                 sll->sll_ifindex = dev->ifindex;
1682
1683         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1684
1685         PACKET_SKB_CB(skb)->origlen = skb->len;
1686
1687         if (pskb_trim(skb, snaplen))
1688                 goto drop_n_acct;
1689
1690         skb_set_owner_r(skb, sk);
1691         skb->dev = NULL;
1692         skb_dst_drop(skb);
1693
1694         /* drop conntrack reference */
1695         nf_reset(skb);
1696
1697         spin_lock(&sk->sk_receive_queue.lock);
1698         po->stats.stats1.tp_packets++;
1699         skb->dropcount = atomic_read(&sk->sk_drops);
1700         __skb_queue_tail(&sk->sk_receive_queue, skb);
1701         spin_unlock(&sk->sk_receive_queue.lock);
1702         sk->sk_data_ready(sk, skb->len);
1703         return 0;
1704
1705 drop_n_acct:
1706         spin_lock(&sk->sk_receive_queue.lock);
1707         po->stats.stats1.tp_drops++;
1708         atomic_inc(&sk->sk_drops);
1709         spin_unlock(&sk->sk_receive_queue.lock);
1710
1711 drop_n_restore:
1712         if (skb_head != skb->data && skb_shared(skb)) {
1713                 skb->data = skb_head;
1714                 skb->len = skb_len;
1715         }
1716 drop:
1717         consume_skb(skb);
1718         return 0;
1719 }
1720
1721 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1722                        struct packet_type *pt, struct net_device *orig_dev)
1723 {
1724         struct sock *sk;
1725         struct packet_sock *po;
1726         struct sockaddr_ll *sll;
1727         union tpacket_uhdr h;
1728         u8 *skb_head = skb->data;
1729         int skb_len = skb->len;
1730         unsigned int snaplen, res;
1731         unsigned long status = TP_STATUS_USER;
1732         unsigned short macoff, netoff, hdrlen;
1733         struct sk_buff *copy_skb = NULL;
1734         struct timespec ts;
1735         __u32 ts_status;
1736
1737         if (skb->pkt_type == PACKET_LOOPBACK)
1738                 goto drop;
1739
1740         sk = pt->af_packet_priv;
1741         po = pkt_sk(sk);
1742
1743         if (!net_eq(dev_net(dev), sock_net(sk)))
1744                 goto drop;
1745
1746         if (dev->header_ops) {
1747                 if (sk->sk_type != SOCK_DGRAM)
1748                         skb_push(skb, skb->data - skb_mac_header(skb));
1749                 else if (skb->pkt_type == PACKET_OUTGOING) {
1750                         /* Special case: outgoing packets have ll header at head */
1751                         skb_pull(skb, skb_network_offset(skb));
1752                 }
1753         }
1754
1755         if (skb->ip_summed == CHECKSUM_PARTIAL)
1756                 status |= TP_STATUS_CSUMNOTREADY;
1757
1758         snaplen = skb->len;
1759
1760         res = run_filter(skb, sk, snaplen);
1761         if (!res)
1762                 goto drop_n_restore;
1763         if (snaplen > res)
1764                 snaplen = res;
1765
1766         if (sk->sk_type == SOCK_DGRAM) {
1767                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1768                                   po->tp_reserve;
1769         } else {
1770                 unsigned int maclen = skb_network_offset(skb);
1771                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1772                                        (maclen < 16 ? 16 : maclen)) +
1773                         po->tp_reserve;
1774                 macoff = netoff - maclen;
1775         }
1776         if (po->tp_version <= TPACKET_V2) {
1777                 if (macoff + snaplen > po->rx_ring.frame_size) {
1778                         if (po->copy_thresh &&
1779                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1780                                 if (skb_shared(skb)) {
1781                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
1782                                 } else {
1783                                         copy_skb = skb_get(skb);
1784                                         skb_head = skb->data;
1785                                 }
1786                                 if (copy_skb)
1787                                         skb_set_owner_r(copy_skb, sk);
1788                         }
1789                         snaplen = po->rx_ring.frame_size - macoff;
1790                         if ((int)snaplen < 0)
1791                                 snaplen = 0;
1792                 }
1793         } else if (unlikely(macoff + snaplen >
1794                             GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
1795                 u32 nval;
1796
1797                 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
1798                 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
1799                             snaplen, nval, macoff);
1800                 snaplen = nval;
1801                 if (unlikely((int)snaplen < 0)) {
1802                         snaplen = 0;
1803                         macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
1804                 }
1805         }
1806         spin_lock(&sk->sk_receive_queue.lock);
1807         h.raw = packet_current_rx_frame(po, skb,
1808                                         TP_STATUS_KERNEL, (macoff+snaplen));
1809         if (!h.raw)
1810                 goto ring_is_full;
1811         if (po->tp_version <= TPACKET_V2) {
1812                 packet_increment_rx_head(po, &po->rx_ring);
1813         /*
1814          * LOSING will be reported till you read the stats,
1815          * because it's COR - Clear On Read.
1816          * Anyways, moving it for V1/V2 only as V3 doesn't need this
1817          * at packet level.
1818          */
1819                 if (po->stats.stats1.tp_drops)
1820                         status |= TP_STATUS_LOSING;
1821         }
1822         po->stats.stats1.tp_packets++;
1823         if (copy_skb) {
1824                 status |= TP_STATUS_COPY;
1825                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1826         }
1827         spin_unlock(&sk->sk_receive_queue.lock);
1828
1829         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1830
1831         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
1832                 getnstimeofday(&ts);
1833
1834         status |= ts_status;
1835
1836         switch (po->tp_version) {
1837         case TPACKET_V1:
1838                 h.h1->tp_len = skb->len;
1839                 h.h1->tp_snaplen = snaplen;
1840                 h.h1->tp_mac = macoff;
1841                 h.h1->tp_net = netoff;
1842                 h.h1->tp_sec = ts.tv_sec;
1843                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
1844                 hdrlen = sizeof(*h.h1);
1845                 break;
1846         case TPACKET_V2:
1847                 h.h2->tp_len = skb->len;
1848                 h.h2->tp_snaplen = snaplen;
1849                 h.h2->tp_mac = macoff;
1850                 h.h2->tp_net = netoff;
1851                 h.h2->tp_sec = ts.tv_sec;
1852                 h.h2->tp_nsec = ts.tv_nsec;
1853                 if (vlan_tx_tag_present(skb)) {
1854                         h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1855                         status |= TP_STATUS_VLAN_VALID;
1856                 } else {
1857                         h.h2->tp_vlan_tci = 0;
1858                 }
1859                 h.h2->tp_padding = 0;
1860                 hdrlen = sizeof(*h.h2);
1861                 break;
1862         case TPACKET_V3:
1863                 /* tp_nxt_offset,vlan are already populated above.
1864                  * So DONT clear those fields here
1865                  */
1866                 h.h3->tp_status |= status;
1867                 h.h3->tp_len = skb->len;
1868                 h.h3->tp_snaplen = snaplen;
1869                 h.h3->tp_mac = macoff;
1870                 h.h3->tp_net = netoff;
1871                 h.h3->tp_sec  = ts.tv_sec;
1872                 h.h3->tp_nsec = ts.tv_nsec;
1873                 hdrlen = sizeof(*h.h3);
1874                 break;
1875         default:
1876                 BUG();
1877         }
1878
1879         sll = h.raw + TPACKET_ALIGN(hdrlen);
1880         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1881         sll->sll_family = AF_PACKET;
1882         sll->sll_hatype = dev->type;
1883         sll->sll_protocol = skb->protocol;
1884         sll->sll_pkttype = skb->pkt_type;
1885         if (unlikely(po->origdev))
1886                 sll->sll_ifindex = orig_dev->ifindex;
1887         else
1888                 sll->sll_ifindex = dev->ifindex;
1889
1890         smp_mb();
1891 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1892         {
1893                 u8 *start, *end;
1894
1895                 if (po->tp_version <= TPACKET_V2) {
1896                         end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1897                                 + macoff + snaplen);
1898                         for (start = h.raw; start < end; start += PAGE_SIZE)
1899                                 flush_dcache_page(pgv_to_page(start));
1900                 }
1901                 smp_wmb();
1902         }
1903 #endif
1904         if (po->tp_version <= TPACKET_V2)
1905                 __packet_set_status(po, h.raw, status);
1906         else
1907                 prb_clear_blk_fill_status(&po->rx_ring);
1908
1909         sk->sk_data_ready(sk, 0);
1910
1911 drop_n_restore:
1912         if (skb_head != skb->data && skb_shared(skb)) {
1913                 skb->data = skb_head;
1914                 skb->len = skb_len;
1915         }
1916 drop:
1917         kfree_skb(skb);
1918         return 0;
1919
1920 ring_is_full:
1921         po->stats.stats1.tp_drops++;
1922         spin_unlock(&sk->sk_receive_queue.lock);
1923
1924         sk->sk_data_ready(sk, 0);
1925         kfree_skb(copy_skb);
1926         goto drop_n_restore;
1927 }
1928
1929 static void tpacket_destruct_skb(struct sk_buff *skb)
1930 {
1931         struct packet_sock *po = pkt_sk(skb->sk);
1932         void *ph;
1933
1934         if (likely(po->tx_ring.pg_vec)) {
1935                 __u32 ts;
1936
1937                 ph = skb_shinfo(skb)->destructor_arg;
1938                 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1939                 atomic_dec(&po->tx_ring.pending);
1940
1941                 ts = __packet_set_timestamp(po, ph, skb);
1942                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
1943         }
1944
1945         sock_wfree(skb);
1946 }
1947
1948 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1949                 void *frame, struct net_device *dev, int size_max,
1950                 __be16 proto, unsigned char *addr, int hlen)
1951 {
1952         union tpacket_uhdr ph;
1953         int to_write, offset, len, tp_len, nr_frags, len_max;
1954         struct socket *sock = po->sk.sk_socket;
1955         struct page *page;
1956         void *data;
1957         int err;
1958
1959         ph.raw = frame;
1960
1961         skb->protocol = proto;
1962         skb->dev = dev;
1963         skb->priority = po->sk.sk_priority;
1964         skb->mark = po->sk.sk_mark;
1965         sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
1966         skb_shinfo(skb)->destructor_arg = ph.raw;
1967
1968         switch (po->tp_version) {
1969         case TPACKET_V2:
1970                 tp_len = ph.h2->tp_len;
1971                 break;
1972         default:
1973                 tp_len = ph.h1->tp_len;
1974                 break;
1975         }
1976         if (unlikely(tp_len > size_max)) {
1977                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1978                 return -EMSGSIZE;
1979         }
1980
1981         skb_reserve(skb, hlen);
1982         skb_reset_network_header(skb);
1983         skb_probe_transport_header(skb, 0);
1984
1985         if (po->tp_tx_has_off) {
1986                 int off_min, off_max, off;
1987                 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
1988                 off_max = po->tx_ring.frame_size - tp_len;
1989                 if (sock->type == SOCK_DGRAM) {
1990                         switch (po->tp_version) {
1991                         case TPACKET_V2:
1992                                 off = ph.h2->tp_net;
1993                                 break;
1994                         default:
1995                                 off = ph.h1->tp_net;
1996                                 break;
1997                         }
1998                 } else {
1999                         switch (po->tp_version) {
2000                         case TPACKET_V2:
2001                                 off = ph.h2->tp_mac;
2002                                 break;
2003                         default:
2004                                 off = ph.h1->tp_mac;
2005                                 break;
2006                         }
2007                 }
2008                 if (unlikely((off < off_min) || (off_max < off)))
2009                         return -EINVAL;
2010                 data = ph.raw + off;
2011         } else {
2012                 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2013         }
2014         to_write = tp_len;
2015
2016         if (sock->type == SOCK_DGRAM) {
2017                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2018                                 NULL, tp_len);
2019                 if (unlikely(err < 0))
2020                         return -EINVAL;
2021         } else if (dev->hard_header_len) {
2022                 /* net device doesn't like empty head */
2023                 if (unlikely(tp_len <= dev->hard_header_len)) {
2024                         pr_err("packet size is too short (%d < %d)\n",
2025                                tp_len, dev->hard_header_len);
2026                         return -EINVAL;
2027                 }
2028
2029                 skb_push(skb, dev->hard_header_len);
2030                 err = skb_store_bits(skb, 0, data,
2031                                 dev->hard_header_len);
2032                 if (unlikely(err))
2033                         return err;
2034
2035                 data += dev->hard_header_len;
2036                 to_write -= dev->hard_header_len;
2037         }
2038
2039         offset = offset_in_page(data);
2040         len_max = PAGE_SIZE - offset;
2041         len = ((to_write > len_max) ? len_max : to_write);
2042
2043         skb->data_len = to_write;
2044         skb->len += to_write;
2045         skb->truesize += to_write;
2046         atomic_add(to_write, &po->sk.sk_wmem_alloc);
2047
2048         while (likely(to_write)) {
2049                 nr_frags = skb_shinfo(skb)->nr_frags;
2050
2051                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2052                         pr_err("Packet exceed the number of skb frags(%lu)\n",
2053                                MAX_SKB_FRAGS);
2054                         return -EFAULT;
2055                 }
2056
2057                 page = pgv_to_page(data);
2058                 data += len;
2059                 flush_dcache_page(page);
2060                 get_page(page);
2061                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2062                 to_write -= len;
2063                 offset = 0;
2064                 len_max = PAGE_SIZE;
2065                 len = ((to_write > len_max) ? len_max : to_write);
2066         }
2067
2068         return tp_len;
2069 }
2070
2071 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2072 {
2073         struct sk_buff *skb;
2074         struct net_device *dev;
2075         __be16 proto;
2076         int err, reserve = 0;
2077         void *ph;
2078         struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2079         int tp_len, size_max;
2080         unsigned char *addr;
2081         int len_sum = 0;
2082         int status = TP_STATUS_AVAILABLE;
2083         int hlen, tlen;
2084
2085         mutex_lock(&po->pg_vec_lock);
2086
2087         if (likely(saddr == NULL)) {
2088                 dev     = packet_cached_dev_get(po);
2089                 proto   = po->num;
2090                 addr    = NULL;
2091         } else {
2092                 err = -EINVAL;
2093                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2094                         goto out;
2095                 if (msg->msg_namelen < (saddr->sll_halen
2096                                         + offsetof(struct sockaddr_ll,
2097                                                 sll_addr)))
2098                         goto out;
2099                 proto   = saddr->sll_protocol;
2100                 addr    = saddr->sll_addr;
2101                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2102         }
2103
2104         err = -ENXIO;
2105         if (unlikely(dev == NULL))
2106                 goto out;
2107         err = -ENETDOWN;
2108         if (unlikely(!(dev->flags & IFF_UP)))
2109                 goto out_put;
2110
2111         reserve = dev->hard_header_len;
2112
2113         size_max = po->tx_ring.frame_size
2114                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2115
2116         if (size_max > dev->mtu + reserve)
2117                 size_max = dev->mtu + reserve;
2118
2119         do {
2120                 ph = packet_current_frame(po, &po->tx_ring,
2121                                 TP_STATUS_SEND_REQUEST);
2122
2123                 if (unlikely(ph == NULL)) {
2124                         schedule();
2125                         continue;
2126                 }
2127
2128                 status = TP_STATUS_SEND_REQUEST;
2129                 hlen = LL_RESERVED_SPACE(dev);
2130                 tlen = dev->needed_tailroom;
2131                 skb = sock_alloc_send_skb(&po->sk,
2132                                 hlen + tlen + sizeof(struct sockaddr_ll),
2133                                 0, &err);
2134
2135                 if (unlikely(skb == NULL))
2136                         goto out_status;
2137
2138                 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2139                                 addr, hlen);
2140
2141                 if (unlikely(tp_len < 0)) {
2142                         if (po->tp_loss) {
2143                                 __packet_set_status(po, ph,
2144                                                 TP_STATUS_AVAILABLE);
2145                                 packet_increment_head(&po->tx_ring);
2146                                 kfree_skb(skb);
2147                                 continue;
2148                         } else {
2149                                 status = TP_STATUS_WRONG_FORMAT;
2150                                 err = tp_len;
2151                                 goto out_status;
2152                         }
2153                 }
2154
2155                 skb->destructor = tpacket_destruct_skb;
2156                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2157                 atomic_inc(&po->tx_ring.pending);
2158
2159                 status = TP_STATUS_SEND_REQUEST;
2160                 err = dev_queue_xmit(skb);
2161                 if (unlikely(err > 0)) {
2162                         err = net_xmit_errno(err);
2163                         if (err && __packet_get_status(po, ph) ==
2164                                    TP_STATUS_AVAILABLE) {
2165                                 /* skb was destructed already */
2166                                 skb = NULL;
2167                                 goto out_status;
2168                         }
2169                         /*
2170                          * skb was dropped but not destructed yet;
2171                          * let's treat it like congestion or err < 0
2172                          */
2173                         err = 0;
2174                 }
2175                 packet_increment_head(&po->tx_ring);
2176                 len_sum += tp_len;
2177         } while (likely((ph != NULL) ||
2178                         ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2179                          (atomic_read(&po->tx_ring.pending))))
2180                 );
2181
2182         err = len_sum;
2183         goto out_put;
2184
2185 out_status:
2186         __packet_set_status(po, ph, status);
2187         kfree_skb(skb);
2188 out_put:
2189         dev_put(dev);
2190 out:
2191         mutex_unlock(&po->pg_vec_lock);
2192         return err;
2193 }
2194
2195 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2196                                         size_t reserve, size_t len,
2197                                         size_t linear, int noblock,
2198                                         int *err)
2199 {
2200         struct sk_buff *skb;
2201
2202         /* Under a page?  Don't bother with paged skb. */
2203         if (prepad + len < PAGE_SIZE || !linear)
2204                 linear = len;
2205
2206         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2207                                    err);
2208         if (!skb)
2209                 return NULL;
2210
2211         skb_reserve(skb, reserve);
2212         skb_put(skb, linear);
2213         skb->data_len = len - linear;
2214         skb->len += len - linear;
2215
2216         return skb;
2217 }
2218
2219 static int packet_snd(struct socket *sock,
2220                           struct msghdr *msg, size_t len)
2221 {
2222         struct sock *sk = sock->sk;
2223         struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2224         struct sk_buff *skb;
2225         struct net_device *dev;
2226         __be16 proto;
2227         unsigned char *addr;
2228         int err, reserve = 0;
2229         struct virtio_net_hdr vnet_hdr = { 0 };
2230         int offset = 0;
2231         int vnet_hdr_len;
2232         struct packet_sock *po = pkt_sk(sk);
2233         unsigned short gso_type = 0;
2234         int hlen, tlen;
2235         int extra_len = 0;
2236
2237         /*
2238          *      Get and verify the address.
2239          */
2240
2241         if (likely(saddr == NULL)) {
2242                 dev     = packet_cached_dev_get(po);
2243                 proto   = po->num;
2244                 addr    = NULL;
2245         } else {
2246                 err = -EINVAL;
2247                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2248                         goto out;
2249                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2250                         goto out;
2251                 proto   = saddr->sll_protocol;
2252                 addr    = saddr->sll_addr;
2253                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2254         }
2255
2256         err = -ENXIO;
2257         if (unlikely(dev == NULL))
2258                 goto out_unlock;
2259         err = -ENETDOWN;
2260         if (unlikely(!(dev->flags & IFF_UP)))
2261                 goto out_unlock;
2262
2263         if (sock->type == SOCK_RAW)
2264                 reserve = dev->hard_header_len;
2265         if (po->has_vnet_hdr) {
2266                 vnet_hdr_len = sizeof(vnet_hdr);
2267
2268                 err = -EINVAL;
2269                 if (len < vnet_hdr_len)
2270                         goto out_unlock;
2271
2272                 len -= vnet_hdr_len;
2273
2274                 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2275                                        vnet_hdr_len);
2276                 if (err < 0)
2277                         goto out_unlock;
2278
2279                 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2280                     (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2281                       vnet_hdr.hdr_len))
2282                         vnet_hdr.hdr_len = vnet_hdr.csum_start +
2283                                                  vnet_hdr.csum_offset + 2;
2284
2285                 err = -EINVAL;
2286                 if (vnet_hdr.hdr_len > len)
2287                         goto out_unlock;
2288
2289                 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2290                         switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2291                         case VIRTIO_NET_HDR_GSO_TCPV4:
2292                                 gso_type = SKB_GSO_TCPV4;
2293                                 break;
2294                         case VIRTIO_NET_HDR_GSO_TCPV6:
2295                                 gso_type = SKB_GSO_TCPV6;
2296                                 break;
2297                         case VIRTIO_NET_HDR_GSO_UDP:
2298                                 gso_type = SKB_GSO_UDP;
2299                                 break;
2300                         default:
2301                                 goto out_unlock;
2302                         }
2303
2304                         if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2305                                 gso_type |= SKB_GSO_TCP_ECN;
2306
2307                         if (vnet_hdr.gso_size == 0)
2308                                 goto out_unlock;
2309
2310                 }
2311         }
2312
2313         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2314                 if (!netif_supports_nofcs(dev)) {
2315                         err = -EPROTONOSUPPORT;
2316                         goto out_unlock;
2317                 }
2318                 extra_len = 4; /* We're doing our own CRC */
2319         }
2320
2321         err = -EMSGSIZE;
2322         if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2323                 goto out_unlock;
2324
2325         err = -ENOBUFS;
2326         hlen = LL_RESERVED_SPACE(dev);
2327         tlen = dev->needed_tailroom;
2328         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2329                                msg->msg_flags & MSG_DONTWAIT, &err);
2330         if (skb == NULL)
2331                 goto out_unlock;
2332
2333         skb_set_network_header(skb, reserve);
2334
2335         err = -EINVAL;
2336         if (sock->type == SOCK_DGRAM &&
2337             (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2338                 goto out_free;
2339
2340         /* Returns -EFAULT on error */
2341         err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2342         if (err)
2343                 goto out_free;
2344
2345         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2346
2347         if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2348                 /* Earlier code assumed this would be a VLAN pkt,
2349                  * double-check this now that we have the actual
2350                  * packet in hand.
2351                  */
2352                 struct ethhdr *ehdr;
2353                 skb_reset_mac_header(skb);
2354                 ehdr = eth_hdr(skb);
2355                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2356                         err = -EMSGSIZE;
2357                         goto out_free;
2358                 }
2359         }
2360
2361         skb->protocol = proto;
2362         skb->dev = dev;
2363         skb->priority = sk->sk_priority;
2364         skb->mark = sk->sk_mark;
2365
2366         if (po->has_vnet_hdr) {
2367                 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2368                         if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2369                                                   vnet_hdr.csum_offset)) {
2370                                 err = -EINVAL;
2371                                 goto out_free;
2372                         }
2373                 }
2374
2375                 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2376                 skb_shinfo(skb)->gso_type = gso_type;
2377
2378                 /* Header must be checked, and gso_segs computed. */
2379                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2380                 skb_shinfo(skb)->gso_segs = 0;
2381
2382                 len += vnet_hdr_len;
2383         }
2384
2385         skb_probe_transport_header(skb, reserve);
2386
2387         if (unlikely(extra_len == 4))
2388                 skb->no_fcs = 1;
2389
2390         /*
2391          *      Now send it
2392          */
2393
2394         err = dev_queue_xmit(skb);
2395         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2396                 goto out_unlock;
2397
2398         dev_put(dev);
2399
2400         return len;
2401
2402 out_free:
2403         kfree_skb(skb);
2404 out_unlock:
2405         if (dev)
2406                 dev_put(dev);
2407 out:
2408         return err;
2409 }
2410
2411 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2412                 struct msghdr *msg, size_t len)
2413 {
2414         struct sock *sk = sock->sk;
2415         struct packet_sock *po = pkt_sk(sk);
2416         if (po->tx_ring.pg_vec)
2417                 return tpacket_snd(po, msg);
2418         else
2419                 return packet_snd(sock, msg, len);
2420 }
2421
2422 /*
2423  *      Close a PACKET socket. This is fairly simple. We immediately go
2424  *      to 'closed' state and remove our protocol entry in the device list.
2425  */
2426
2427 static int packet_release(struct socket *sock)
2428 {
2429         struct sock *sk = sock->sk;
2430         struct packet_sock *po;
2431         struct net *net;
2432         union tpacket_req_u req_u;
2433
2434         if (!sk)
2435                 return 0;
2436
2437         net = sock_net(sk);
2438         po = pkt_sk(sk);
2439
2440         mutex_lock(&net->packet.sklist_lock);
2441         sk_del_node_init_rcu(sk);
2442         mutex_unlock(&net->packet.sklist_lock);
2443
2444         preempt_disable();
2445         sock_prot_inuse_add(net, sk->sk_prot, -1);
2446         preempt_enable();
2447
2448         spin_lock(&po->bind_lock);
2449         unregister_prot_hook(sk, false);
2450         packet_cached_dev_reset(po);
2451
2452         if (po->prot_hook.dev) {
2453                 dev_put(po->prot_hook.dev);
2454                 po->prot_hook.dev = NULL;
2455         }
2456         spin_unlock(&po->bind_lock);
2457
2458         packet_flush_mclist(sk);
2459
2460         if (po->rx_ring.pg_vec) {
2461                 memset(&req_u, 0, sizeof(req_u));
2462                 packet_set_ring(sk, &req_u, 1, 0);
2463         }
2464
2465         if (po->tx_ring.pg_vec) {
2466                 memset(&req_u, 0, sizeof(req_u));
2467                 packet_set_ring(sk, &req_u, 1, 1);
2468         }
2469
2470         fanout_release(sk);
2471
2472         synchronize_net();
2473         /*
2474          *      Now the socket is dead. No more input will appear.
2475          */
2476         sock_orphan(sk);
2477         sock->sk = NULL;
2478
2479         /* Purge queues */
2480
2481         skb_queue_purge(&sk->sk_receive_queue);
2482         sk_refcnt_debug_release(sk);
2483
2484         sock_put(sk);
2485         return 0;
2486 }
2487
2488 /*
2489  *      Attach a packet hook.
2490  */
2491
2492 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2493 {
2494         struct packet_sock *po = pkt_sk(sk);
2495
2496         if (po->fanout) {
2497                 if (dev)
2498                         dev_put(dev);
2499
2500                 return -EINVAL;
2501         }
2502
2503         lock_sock(sk);
2504
2505         spin_lock(&po->bind_lock);
2506         unregister_prot_hook(sk, true);
2507
2508         po->num = protocol;
2509         po->prot_hook.type = protocol;
2510         if (po->prot_hook.dev)
2511                 dev_put(po->prot_hook.dev);
2512
2513         po->prot_hook.dev = dev;
2514         po->ifindex = dev ? dev->ifindex : 0;
2515
2516         packet_cached_dev_assign(po, dev);
2517
2518         if (protocol == 0)
2519                 goto out_unlock;
2520
2521         if (!dev || (dev->flags & IFF_UP)) {
2522                 register_prot_hook(sk);
2523         } else {
2524                 sk->sk_err = ENETDOWN;
2525                 if (!sock_flag(sk, SOCK_DEAD))
2526                         sk->sk_error_report(sk);
2527         }
2528
2529 out_unlock:
2530         spin_unlock(&po->bind_lock);
2531         release_sock(sk);
2532         return 0;
2533 }
2534
2535 /*
2536  *      Bind a packet socket to a device
2537  */
2538
2539 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2540                             int addr_len)
2541 {
2542         struct sock *sk = sock->sk;
2543         char name[15];
2544         struct net_device *dev;
2545         int err = -ENODEV;
2546
2547         /*
2548          *      Check legality
2549          */
2550
2551         if (addr_len != sizeof(struct sockaddr))
2552                 return -EINVAL;
2553         strlcpy(name, uaddr->sa_data, sizeof(name));
2554
2555         dev = dev_get_by_name(sock_net(sk), name);
2556         if (dev)
2557                 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2558         return err;
2559 }
2560
2561 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2562 {
2563         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2564         struct sock *sk = sock->sk;
2565         struct net_device *dev = NULL;
2566         int err;
2567
2568
2569         /*
2570          *      Check legality
2571          */
2572
2573         if (addr_len < sizeof(struct sockaddr_ll))
2574                 return -EINVAL;
2575         if (sll->sll_family != AF_PACKET)
2576                 return -EINVAL;
2577
2578         if (sll->sll_ifindex) {
2579                 err = -ENODEV;
2580                 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2581                 if (dev == NULL)
2582                         goto out;
2583         }
2584         err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2585
2586 out:
2587         return err;
2588 }
2589
2590 static struct proto packet_proto = {
2591         .name     = "PACKET",
2592         .owner    = THIS_MODULE,
2593         .obj_size = sizeof(struct packet_sock),
2594 };
2595
2596 /*
2597  *      Create a packet of type SOCK_PACKET.
2598  */
2599
2600 static int packet_create(struct net *net, struct socket *sock, int protocol,
2601                          int kern)
2602 {
2603         struct sock *sk;
2604         struct packet_sock *po;
2605         __be16 proto = (__force __be16)protocol; /* weird, but documented */
2606         int err;
2607
2608         if (!ns_capable(net->user_ns, CAP_NET_RAW))
2609                 return -EPERM;
2610         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2611             sock->type != SOCK_PACKET)
2612                 return -ESOCKTNOSUPPORT;
2613
2614         sock->state = SS_UNCONNECTED;
2615
2616         err = -ENOBUFS;
2617         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2618         if (sk == NULL)
2619                 goto out;
2620
2621         sock->ops = &packet_ops;
2622         if (sock->type == SOCK_PACKET)
2623                 sock->ops = &packet_ops_spkt;
2624
2625         sock_init_data(sock, sk);
2626
2627         po = pkt_sk(sk);
2628         sk->sk_family = PF_PACKET;
2629         po->num = proto;
2630
2631         packet_cached_dev_reset(po);
2632
2633         sk->sk_destruct = packet_sock_destruct;
2634         sk_refcnt_debug_inc(sk);
2635
2636         /*
2637          *      Attach a protocol block
2638          */
2639
2640         spin_lock_init(&po->bind_lock);
2641         mutex_init(&po->pg_vec_lock);
2642         po->prot_hook.func = packet_rcv;
2643
2644         if (sock->type == SOCK_PACKET)
2645                 po->prot_hook.func = packet_rcv_spkt;
2646
2647         po->prot_hook.af_packet_priv = sk;
2648
2649         if (proto) {
2650                 po->prot_hook.type = proto;
2651                 register_prot_hook(sk);
2652         }
2653
2654         mutex_lock(&net->packet.sklist_lock);
2655         sk_add_node_rcu(sk, &net->packet.sklist);
2656         mutex_unlock(&net->packet.sklist_lock);
2657
2658         preempt_disable();
2659         sock_prot_inuse_add(net, &packet_proto, 1);
2660         preempt_enable();
2661
2662         return 0;
2663 out:
2664         return err;
2665 }
2666
2667 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
2668 {
2669         struct sock_exterr_skb *serr;
2670         struct sk_buff *skb, *skb2;
2671         int copied, err;
2672
2673         err = -EAGAIN;
2674         skb = skb_dequeue(&sk->sk_error_queue);
2675         if (skb == NULL)
2676                 goto out;
2677
2678         copied = skb->len;
2679         if (copied > len) {
2680                 msg->msg_flags |= MSG_TRUNC;
2681                 copied = len;
2682         }
2683         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2684         if (err)
2685                 goto out_free_skb;
2686
2687         sock_recv_timestamp(msg, sk, skb);
2688
2689         serr = SKB_EXT_ERR(skb);
2690         put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP,
2691                  sizeof(serr->ee), &serr->ee);
2692
2693         msg->msg_flags |= MSG_ERRQUEUE;
2694         err = copied;
2695
2696         /* Reset and regenerate socket error */
2697         spin_lock_bh(&sk->sk_error_queue.lock);
2698         sk->sk_err = 0;
2699         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2700                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2701                 spin_unlock_bh(&sk->sk_error_queue.lock);
2702                 sk->sk_error_report(sk);
2703         } else
2704                 spin_unlock_bh(&sk->sk_error_queue.lock);
2705
2706 out_free_skb:
2707         kfree_skb(skb);
2708 out:
2709         return err;
2710 }
2711
2712 /*
2713  *      Pull a packet from our receive queue and hand it to the user.
2714  *      If necessary we block.
2715  */
2716
2717 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2718                           struct msghdr *msg, size_t len, int flags)
2719 {
2720         struct sock *sk = sock->sk;
2721         struct sk_buff *skb;
2722         int copied, err;
2723         int vnet_hdr_len = 0;
2724
2725         err = -EINVAL;
2726         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2727                 goto out;
2728
2729 #if 0
2730         /* What error should we return now? EUNATTACH? */
2731         if (pkt_sk(sk)->ifindex < 0)
2732                 return -ENODEV;
2733 #endif
2734
2735         if (flags & MSG_ERRQUEUE) {
2736                 err = packet_recv_error(sk, msg, len);
2737                 goto out;
2738         }
2739
2740         /*
2741          *      Call the generic datagram receiver. This handles all sorts
2742          *      of horrible races and re-entrancy so we can forget about it
2743          *      in the protocol layers.
2744          *
2745          *      Now it will return ENETDOWN, if device have just gone down,
2746          *      but then it will block.
2747          */
2748
2749         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2750
2751         /*
2752          *      An error occurred so return it. Because skb_recv_datagram()
2753          *      handles the blocking we don't see and worry about blocking
2754          *      retries.
2755          */
2756
2757         if (skb == NULL)
2758                 goto out;
2759
2760         if (pkt_sk(sk)->has_vnet_hdr) {
2761                 struct virtio_net_hdr vnet_hdr = { 0 };
2762
2763                 err = -EINVAL;
2764                 vnet_hdr_len = sizeof(vnet_hdr);
2765                 if (len < vnet_hdr_len)
2766                         goto out_free;
2767
2768                 len -= vnet_hdr_len;
2769
2770                 if (skb_is_gso(skb)) {
2771                         struct skb_shared_info *sinfo = skb_shinfo(skb);
2772
2773                         /* This is a hint as to how much should be linear. */
2774                         vnet_hdr.hdr_len = skb_headlen(skb);
2775                         vnet_hdr.gso_size = sinfo->gso_size;
2776                         if (sinfo->gso_type & SKB_GSO_TCPV4)
2777                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2778                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
2779                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2780                         else if (sinfo->gso_type & SKB_GSO_UDP)
2781                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2782                         else if (sinfo->gso_type & SKB_GSO_FCOE)
2783                                 goto out_free;
2784                         else
2785                                 BUG();
2786                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2787                                 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2788                 } else
2789                         vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2790
2791                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2792                         vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2793                         vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2794                         vnet_hdr.csum_offset = skb->csum_offset;
2795                 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2796                         vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2797                 } /* else everything is zero */
2798
2799                 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2800                                      vnet_hdr_len);
2801                 if (err < 0)
2802                         goto out_free;
2803         }
2804
2805         /* You lose any data beyond the buffer you gave. If it worries
2806          * a user program they can ask the device for its MTU
2807          * anyway.
2808          */
2809         copied = skb->len;
2810         if (copied > len) {
2811                 copied = len;
2812                 msg->msg_flags |= MSG_TRUNC;
2813         }
2814
2815         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2816         if (err)
2817                 goto out_free;
2818
2819         sock_recv_ts_and_drops(msg, sk, skb);
2820
2821         if (msg->msg_name) {
2822                 /* If the address length field is there to be filled
2823                  * in, we fill it in now.
2824                  */
2825                 if (sock->type == SOCK_PACKET) {
2826                         msg->msg_namelen = sizeof(struct sockaddr_pkt);
2827                 } else {
2828                         struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
2829                         msg->msg_namelen = sll->sll_halen +
2830                                 offsetof(struct sockaddr_ll, sll_addr);
2831                 }
2832                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2833                        msg->msg_namelen);
2834         }
2835
2836         if (pkt_sk(sk)->auxdata) {
2837                 struct tpacket_auxdata aux;
2838
2839                 aux.tp_status = TP_STATUS_USER;
2840                 if (skb->ip_summed == CHECKSUM_PARTIAL)
2841                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2842                 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2843                 aux.tp_snaplen = skb->len;
2844                 aux.tp_mac = 0;
2845                 aux.tp_net = skb_network_offset(skb);
2846                 if (vlan_tx_tag_present(skb)) {
2847                         aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2848                         aux.tp_status |= TP_STATUS_VLAN_VALID;
2849                 } else {
2850                         aux.tp_vlan_tci = 0;
2851                 }
2852                 aux.tp_padding = 0;
2853                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2854         }
2855
2856         /*
2857          *      Free or return the buffer as appropriate. Again this
2858          *      hides all the races and re-entrancy issues from us.
2859          */
2860         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2861
2862 out_free:
2863         skb_free_datagram(sk, skb);
2864 out:
2865         return err;
2866 }
2867
2868 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2869                                int *uaddr_len, int peer)
2870 {
2871         struct net_device *dev;
2872         struct sock *sk = sock->sk;
2873
2874         if (peer)
2875                 return -EOPNOTSUPP;
2876
2877         uaddr->sa_family = AF_PACKET;
2878         memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
2879         rcu_read_lock();
2880         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2881         if (dev)
2882                 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
2883         rcu_read_unlock();
2884         *uaddr_len = sizeof(*uaddr);
2885
2886         return 0;
2887 }
2888
2889 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2890                           int *uaddr_len, int peer)
2891 {
2892         struct net_device *dev;
2893         struct sock *sk = sock->sk;
2894         struct packet_sock *po = pkt_sk(sk);
2895         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2896
2897         if (peer)
2898                 return -EOPNOTSUPP;
2899
2900         sll->sll_family = AF_PACKET;
2901         sll->sll_ifindex = po->ifindex;
2902         sll->sll_protocol = po->num;
2903         sll->sll_pkttype = 0;
2904         rcu_read_lock();
2905         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2906         if (dev) {
2907                 sll->sll_hatype = dev->type;
2908                 sll->sll_halen = dev->addr_len;
2909                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2910         } else {
2911                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
2912                 sll->sll_halen = 0;
2913         }
2914         rcu_read_unlock();
2915         *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2916
2917         return 0;
2918 }
2919
2920 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2921                          int what)
2922 {
2923         switch (i->type) {
2924         case PACKET_MR_MULTICAST:
2925                 if (i->alen != dev->addr_len)
2926                         return -EINVAL;
2927                 if (what > 0)
2928                         return dev_mc_add(dev, i->addr);
2929                 else
2930                         return dev_mc_del(dev, i->addr);
2931                 break;
2932         case PACKET_MR_PROMISC:
2933                 return dev_set_promiscuity(dev, what);
2934                 break;
2935         case PACKET_MR_ALLMULTI:
2936                 return dev_set_allmulti(dev, what);
2937                 break;
2938         case PACKET_MR_UNICAST:
2939                 if (i->alen != dev->addr_len)
2940                         return -EINVAL;
2941                 if (what > 0)
2942                         return dev_uc_add(dev, i->addr);
2943                 else
2944                         return dev_uc_del(dev, i->addr);
2945                 break;
2946         default:
2947                 break;
2948         }
2949         return 0;
2950 }
2951
2952 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2953 {
2954         for ( ; i; i = i->next) {
2955                 if (i->ifindex == dev->ifindex)
2956                         packet_dev_mc(dev, i, what);
2957         }
2958 }
2959
2960 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2961 {
2962         struct packet_sock *po = pkt_sk(sk);
2963         struct packet_mclist *ml, *i;
2964         struct net_device *dev;
2965         int err;
2966
2967         rtnl_lock();
2968
2969         err = -ENODEV;
2970         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2971         if (!dev)
2972                 goto done;
2973
2974         err = -EINVAL;
2975         if (mreq->mr_alen > dev->addr_len)
2976                 goto done;
2977
2978         err = -ENOBUFS;
2979         i = kmalloc(sizeof(*i), GFP_KERNEL);
2980         if (i == NULL)
2981                 goto done;
2982
2983         err = 0;
2984         for (ml = po->mclist; ml; ml = ml->next) {
2985                 if (ml->ifindex == mreq->mr_ifindex &&
2986                     ml->type == mreq->mr_type &&
2987                     ml->alen == mreq->mr_alen &&
2988                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2989                         ml->count++;
2990                         /* Free the new element ... */
2991                         kfree(i);
2992                         goto done;
2993                 }
2994         }
2995
2996         i->type = mreq->mr_type;
2997         i->ifindex = mreq->mr_ifindex;
2998         i->alen = mreq->mr_alen;
2999         memcpy(i->addr, mreq->mr_address, i->alen);
3000         i->count = 1;
3001         i->next = po->mclist;
3002         po->mclist = i;
3003         err = packet_dev_mc(dev, i, 1);
3004         if (err) {
3005                 po->mclist = i->next;
3006                 kfree(i);
3007         }
3008
3009 done:
3010         rtnl_unlock();
3011         return err;
3012 }
3013
3014 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3015 {
3016         struct packet_mclist *ml, **mlp;
3017
3018         rtnl_lock();
3019
3020         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3021                 if (ml->ifindex == mreq->mr_ifindex &&
3022                     ml->type == mreq->mr_type &&
3023                     ml->alen == mreq->mr_alen &&
3024                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3025                         if (--ml->count == 0) {
3026                                 struct net_device *dev;
3027                                 *mlp = ml->next;
3028                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3029                                 if (dev)
3030                                         packet_dev_mc(dev, ml, -1);
3031                                 kfree(ml);
3032                         }
3033                         rtnl_unlock();
3034                         return 0;
3035                 }
3036         }
3037         rtnl_unlock();
3038         return -EADDRNOTAVAIL;
3039 }
3040
3041 static void packet_flush_mclist(struct sock *sk)
3042 {
3043         struct packet_sock *po = pkt_sk(sk);
3044         struct packet_mclist *ml;
3045
3046         if (!po->mclist)
3047                 return;
3048
3049         rtnl_lock();
3050         while ((ml = po->mclist) != NULL) {
3051                 struct net_device *dev;
3052
3053                 po->mclist = ml->next;
3054                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3055                 if (dev != NULL)
3056                         packet_dev_mc(dev, ml, -1);
3057                 kfree(ml);
3058         }
3059         rtnl_unlock();
3060 }
3061
3062 static int
3063 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3064 {
3065         struct sock *sk = sock->sk;
3066         struct packet_sock *po = pkt_sk(sk);
3067         int ret;
3068
3069         if (level != SOL_PACKET)
3070                 return -ENOPROTOOPT;
3071
3072         switch (optname) {
3073         case PACKET_ADD_MEMBERSHIP:
3074         case PACKET_DROP_MEMBERSHIP:
3075         {
3076                 struct packet_mreq_max mreq;
3077                 int len = optlen;
3078                 memset(&mreq, 0, sizeof(mreq));
3079                 if (len < sizeof(struct packet_mreq))
3080                         return -EINVAL;
3081                 if (len > sizeof(mreq))
3082                         len = sizeof(mreq);
3083                 if (copy_from_user(&mreq, optval, len))
3084                         return -EFAULT;
3085                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3086                         return -EINVAL;
3087                 if (optname == PACKET_ADD_MEMBERSHIP)
3088                         ret = packet_mc_add(sk, &mreq);
3089                 else
3090                         ret = packet_mc_drop(sk, &mreq);
3091                 return ret;
3092         }
3093
3094         case PACKET_RX_RING:
3095         case PACKET_TX_RING:
3096         {
3097                 union tpacket_req_u req_u;
3098                 int len;
3099
3100                 switch (po->tp_version) {
3101                 case TPACKET_V1:
3102                 case TPACKET_V2:
3103                         len = sizeof(req_u.req);
3104                         break;
3105                 case TPACKET_V3:
3106                 default:
3107                         len = sizeof(req_u.req3);
3108                         break;
3109                 }
3110                 if (optlen < len)
3111                         return -EINVAL;
3112                 if (pkt_sk(sk)->has_vnet_hdr)
3113                         return -EINVAL;
3114                 if (copy_from_user(&req_u.req, optval, len))
3115                         return -EFAULT;
3116                 return packet_set_ring(sk, &req_u, 0,
3117                         optname == PACKET_TX_RING);
3118         }
3119         case PACKET_COPY_THRESH:
3120         {
3121                 int val;
3122
3123                 if (optlen != sizeof(val))
3124                         return -EINVAL;
3125                 if (copy_from_user(&val, optval, sizeof(val)))
3126                         return -EFAULT;
3127
3128                 pkt_sk(sk)->copy_thresh = val;
3129                 return 0;
3130         }
3131         case PACKET_VERSION:
3132         {
3133                 int val;
3134
3135                 if (optlen != sizeof(val))
3136                         return -EINVAL;
3137                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3138                         return -EBUSY;
3139                 if (copy_from_user(&val, optval, sizeof(val)))
3140                         return -EFAULT;
3141                 switch (val) {
3142                 case TPACKET_V1:
3143                 case TPACKET_V2:
3144                 case TPACKET_V3:
3145                         po->tp_version = val;
3146                         return 0;
3147                 default:
3148                         return -EINVAL;
3149                 }
3150         }
3151         case PACKET_RESERVE:
3152         {
3153                 unsigned int val;
3154
3155                 if (optlen != sizeof(val))
3156                         return -EINVAL;
3157                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3158                         return -EBUSY;
3159                 if (copy_from_user(&val, optval, sizeof(val)))
3160                         return -EFAULT;
3161                 po->tp_reserve = val;
3162                 return 0;
3163         }
3164         case PACKET_LOSS:
3165         {
3166                 unsigned int val;
3167
3168                 if (optlen != sizeof(val))
3169                         return -EINVAL;
3170                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3171                         return -EBUSY;
3172                 if (copy_from_user(&val, optval, sizeof(val)))
3173                         return -EFAULT;
3174                 po->tp_loss = !!val;
3175                 return 0;
3176         }
3177         case PACKET_AUXDATA:
3178         {
3179                 int val;
3180
3181                 if (optlen < sizeof(val))
3182                         return -EINVAL;
3183                 if (copy_from_user(&val, optval, sizeof(val)))
3184                         return -EFAULT;
3185
3186                 po->auxdata = !!val;
3187                 return 0;
3188         }
3189         case PACKET_ORIGDEV:
3190         {
3191                 int val;
3192
3193                 if (optlen < sizeof(val))
3194                         return -EINVAL;
3195                 if (copy_from_user(&val, optval, sizeof(val)))
3196                         return -EFAULT;
3197
3198                 po->origdev = !!val;
3199                 return 0;
3200         }
3201         case PACKET_VNET_HDR:
3202         {
3203                 int val;
3204
3205                 if (sock->type != SOCK_RAW)
3206                         return -EINVAL;
3207                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3208                         return -EBUSY;
3209                 if (optlen < sizeof(val))
3210                         return -EINVAL;
3211                 if (copy_from_user(&val, optval, sizeof(val)))
3212                         return -EFAULT;
3213
3214                 po->has_vnet_hdr = !!val;
3215                 return 0;
3216         }
3217         case PACKET_TIMESTAMP:
3218         {
3219                 int val;
3220
3221                 if (optlen != sizeof(val))
3222                         return -EINVAL;
3223                 if (copy_from_user(&val, optval, sizeof(val)))
3224                         return -EFAULT;
3225
3226                 po->tp_tstamp = val;
3227                 return 0;
3228         }
3229         case PACKET_FANOUT:
3230         {
3231                 int val;
3232
3233                 if (optlen != sizeof(val))
3234                         return -EINVAL;
3235                 if (copy_from_user(&val, optval, sizeof(val)))
3236                         return -EFAULT;
3237
3238                 return fanout_add(sk, val & 0xffff, val >> 16);
3239         }
3240         case PACKET_TX_HAS_OFF:
3241         {
3242                 unsigned int val;
3243
3244                 if (optlen != sizeof(val))
3245                         return -EINVAL;
3246                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3247                         return -EBUSY;
3248                 if (copy_from_user(&val, optval, sizeof(val)))
3249                         return -EFAULT;
3250                 po->tp_tx_has_off = !!val;
3251                 return 0;
3252         }
3253         default:
3254                 return -ENOPROTOOPT;
3255         }
3256 }
3257
3258 static int packet_getsockopt(struct socket *sock, int level, int optname,
3259                              char __user *optval, int __user *optlen)
3260 {
3261         int len;
3262         int val, lv = sizeof(val);
3263         struct sock *sk = sock->sk;
3264         struct packet_sock *po = pkt_sk(sk);
3265         void *data = &val;
3266         union tpacket_stats_u st;
3267
3268         if (level != SOL_PACKET)
3269                 return -ENOPROTOOPT;
3270
3271         if (get_user(len, optlen))
3272                 return -EFAULT;
3273
3274         if (len < 0)
3275                 return -EINVAL;
3276
3277         switch (optname) {
3278         case PACKET_STATISTICS:
3279                 spin_lock_bh(&sk->sk_receive_queue.lock);
3280                 memcpy(&st, &po->stats, sizeof(st));
3281                 memset(&po->stats, 0, sizeof(po->stats));
3282                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3283
3284                 if (po->tp_version == TPACKET_V3) {
3285                         lv = sizeof(struct tpacket_stats_v3);
3286                         st.stats3.tp_packets += st.stats3.tp_drops;
3287                         data = &st.stats3;
3288                 } else {
3289                         lv = sizeof(struct tpacket_stats);
3290                         st.stats1.tp_packets += st.stats1.tp_drops;
3291                         data = &st.stats1;
3292                 }
3293
3294                 break;
3295         case PACKET_AUXDATA:
3296                 val = po->auxdata;
3297                 break;
3298         case PACKET_ORIGDEV:
3299                 val = po->origdev;
3300                 break;
3301         case PACKET_VNET_HDR:
3302                 val = po->has_vnet_hdr;
3303                 break;
3304         case PACKET_VERSION:
3305                 val = po->tp_version;
3306                 break;
3307         case PACKET_HDRLEN:
3308                 if (len > sizeof(int))
3309                         len = sizeof(int);
3310                 if (copy_from_user(&val, optval, len))
3311                         return -EFAULT;
3312                 switch (val) {
3313                 case TPACKET_V1:
3314                         val = sizeof(struct tpacket_hdr);
3315                         break;
3316                 case TPACKET_V2:
3317                         val = sizeof(struct tpacket2_hdr);
3318                         break;
3319                 case TPACKET_V3:
3320                         val = sizeof(struct tpacket3_hdr);
3321                         break;
3322                 default:
3323                         return -EINVAL;
3324                 }
3325                 break;
3326         case PACKET_RESERVE:
3327                 val = po->tp_reserve;
3328                 break;
3329         case PACKET_LOSS:
3330                 val = po->tp_loss;
3331                 break;
3332         case PACKET_TIMESTAMP:
3333                 val = po->tp_tstamp;
3334                 break;
3335         case PACKET_FANOUT:
3336                 val = (po->fanout ?
3337                        ((u32)po->fanout->id |
3338                         ((u32)po->fanout->type << 16) |
3339                         ((u32)po->fanout->flags << 24)) :
3340                        0);
3341                 break;
3342         case PACKET_TX_HAS_OFF:
3343                 val = po->tp_tx_has_off;
3344                 break;
3345         default:
3346                 return -ENOPROTOOPT;
3347         }
3348
3349         if (len > lv)
3350                 len = lv;
3351         if (put_user(len, optlen))
3352                 return -EFAULT;
3353         if (copy_to_user(optval, data, len))
3354                 return -EFAULT;
3355         return 0;
3356 }
3357
3358
3359 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
3360 {
3361         struct sock *sk;
3362         struct net_device *dev = data;
3363         struct net *net = dev_net(dev);
3364
3365         rcu_read_lock();
3366         sk_for_each_rcu(sk, &net->packet.sklist) {
3367                 struct packet_sock *po = pkt_sk(sk);
3368
3369                 switch (msg) {
3370                 case NETDEV_UNREGISTER:
3371                         if (po->mclist)
3372                                 packet_dev_mclist(dev, po->mclist, -1);
3373                         /* fallthrough */
3374
3375                 case NETDEV_DOWN:
3376                         if (dev->ifindex == po->ifindex) {
3377                                 spin_lock(&po->bind_lock);
3378                                 if (po->running) {
3379                                         __unregister_prot_hook(sk, false);
3380                                         sk->sk_err = ENETDOWN;
3381                                         if (!sock_flag(sk, SOCK_DEAD))
3382                                                 sk->sk_error_report(sk);
3383                                 }
3384                                 if (msg == NETDEV_UNREGISTER) {
3385                                         packet_cached_dev_reset(po);
3386                                         po->ifindex = -1;
3387                                         if (po->prot_hook.dev)
3388                                                 dev_put(po->prot_hook.dev);
3389                                         po->prot_hook.dev = NULL;
3390                                 }
3391                                 spin_unlock(&po->bind_lock);
3392                         }
3393                         break;
3394                 case NETDEV_UP:
3395                         if (dev->ifindex == po->ifindex) {
3396                                 spin_lock(&po->bind_lock);
3397                                 if (po->num)
3398                                         register_prot_hook(sk);
3399                                 spin_unlock(&po->bind_lock);
3400                         }
3401                         break;
3402                 }
3403         }
3404         rcu_read_unlock();
3405         return NOTIFY_DONE;
3406 }
3407
3408
3409 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3410                         unsigned long arg)
3411 {
3412         struct sock *sk = sock->sk;
3413
3414         switch (cmd) {
3415         case SIOCOUTQ:
3416         {
3417                 int amount = sk_wmem_alloc_get(sk);
3418
3419                 return put_user(amount, (int __user *)arg);
3420         }
3421         case SIOCINQ:
3422         {
3423                 struct sk_buff *skb;
3424                 int amount = 0;
3425
3426                 spin_lock_bh(&sk->sk_receive_queue.lock);
3427                 skb = skb_peek(&sk->sk_receive_queue);
3428                 if (skb)
3429                         amount = skb->len;
3430                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3431                 return put_user(amount, (int __user *)arg);
3432         }
3433         case SIOCGSTAMP:
3434                 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3435         case SIOCGSTAMPNS:
3436                 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3437
3438 #ifdef CONFIG_INET
3439         case SIOCADDRT:
3440         case SIOCDELRT:
3441         case SIOCDARP:
3442         case SIOCGARP:
3443         case SIOCSARP:
3444         case SIOCGIFADDR:
3445         case SIOCSIFADDR:
3446         case SIOCGIFBRDADDR:
3447         case SIOCSIFBRDADDR:
3448         case SIOCGIFNETMASK:
3449         case SIOCSIFNETMASK:
3450         case SIOCGIFDSTADDR:
3451         case SIOCSIFDSTADDR:
3452         case SIOCSIFFLAGS:
3453                 return inet_dgram_ops.ioctl(sock, cmd, arg);
3454 #endif
3455
3456         default:
3457                 return -ENOIOCTLCMD;
3458         }
3459         return 0;
3460 }
3461
3462 static unsigned int packet_poll(struct file *file, struct socket *sock,
3463                                 poll_table *wait)
3464 {
3465         struct sock *sk = sock->sk;
3466         struct packet_sock *po = pkt_sk(sk);
3467         unsigned int mask = datagram_poll(file, sock, wait);
3468
3469         spin_lock_bh(&sk->sk_receive_queue.lock);
3470         if (po->rx_ring.pg_vec) {
3471                 if (!packet_previous_rx_frame(po, &po->rx_ring,
3472                         TP_STATUS_KERNEL))
3473                         mask |= POLLIN | POLLRDNORM;
3474         }
3475         spin_unlock_bh(&sk->sk_receive_queue.lock);
3476         spin_lock_bh(&sk->sk_write_queue.lock);
3477         if (po->tx_ring.pg_vec) {
3478                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3479                         mask |= POLLOUT | POLLWRNORM;
3480         }
3481         spin_unlock_bh(&sk->sk_write_queue.lock);
3482         return mask;
3483 }
3484
3485
3486 /* Dirty? Well, I still did not learn better way to account
3487  * for user mmaps.
3488  */
3489
3490 static void packet_mm_open(struct vm_area_struct *vma)
3491 {
3492         struct file *file = vma->vm_file;
3493         struct socket *sock = file->private_data;
3494         struct sock *sk = sock->sk;
3495
3496         if (sk)
3497                 atomic_inc(&pkt_sk(sk)->mapped);
3498 }
3499
3500 static void packet_mm_close(struct vm_area_struct *vma)
3501 {
3502         struct file *file = vma->vm_file;
3503         struct socket *sock = file->private_data;
3504         struct sock *sk = sock->sk;
3505
3506         if (sk)
3507                 atomic_dec(&pkt_sk(sk)->mapped);
3508 }
3509
3510 static const struct vm_operations_struct packet_mmap_ops = {
3511         .open   =       packet_mm_open,
3512         .close  =       packet_mm_close,
3513 };
3514
3515 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3516                         unsigned int len)
3517 {
3518         int i;
3519
3520         for (i = 0; i < len; i++) {
3521                 if (likely(pg_vec[i].buffer)) {
3522                         if (is_vmalloc_addr(pg_vec[i].buffer))
3523                                 vfree(pg_vec[i].buffer);
3524                         else
3525                                 free_pages((unsigned long)pg_vec[i].buffer,
3526                                            order);
3527                         pg_vec[i].buffer = NULL;
3528                 }
3529         }
3530         kfree(pg_vec);
3531 }
3532
3533 static char *alloc_one_pg_vec_page(unsigned long order)
3534 {
3535         char *buffer = NULL;
3536         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3537                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3538
3539         buffer = (char *) __get_free_pages(gfp_flags, order);
3540
3541         if (buffer)
3542                 return buffer;
3543
3544         /*
3545          * __get_free_pages failed, fall back to vmalloc
3546          */
3547         buffer = vzalloc((1 << order) * PAGE_SIZE);
3548
3549         if (buffer)
3550                 return buffer;
3551
3552         /*
3553          * vmalloc failed, lets dig into swap here
3554          */
3555         gfp_flags &= ~__GFP_NORETRY;
3556         buffer = (char *)__get_free_pages(gfp_flags, order);
3557         if (buffer)
3558                 return buffer;
3559
3560         /*
3561          * complete and utter failure
3562          */
3563         return NULL;
3564 }
3565
3566 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3567 {
3568         unsigned int block_nr = req->tp_block_nr;
3569         struct pgv *pg_vec;
3570         int i;
3571
3572         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3573         if (unlikely(!pg_vec))
3574                 goto out;
3575
3576         for (i = 0; i < block_nr; i++) {
3577                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3578                 if (unlikely(!pg_vec[i].buffer))
3579                         goto out_free_pgvec;
3580         }
3581
3582 out:
3583         return pg_vec;
3584
3585 out_free_pgvec:
3586         free_pg_vec(pg_vec, order, block_nr);
3587         pg_vec = NULL;
3588         goto out;
3589 }
3590
3591 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3592                 int closing, int tx_ring)
3593 {
3594         struct pgv *pg_vec = NULL;
3595         struct packet_sock *po = pkt_sk(sk);
3596         int was_running, order = 0;
3597         struct packet_ring_buffer *rb;
3598         struct sk_buff_head *rb_queue;
3599         __be16 num;
3600         int err = -EINVAL;
3601         /* Added to avoid minimal code churn */
3602         struct tpacket_req *req = &req_u->req;
3603
3604         /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3605         if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3606                 WARN(1, "Tx-ring is not supported.\n");
3607                 goto out;
3608         }
3609
3610         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3611         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3612
3613         err = -EBUSY;
3614         if (!closing) {
3615                 if (atomic_read(&po->mapped))
3616                         goto out;
3617                 if (atomic_read(&rb->pending))
3618                         goto out;
3619         }
3620
3621         if (req->tp_block_nr) {
3622                 /* Sanity tests and some calculations */
3623                 err = -EBUSY;
3624                 if (unlikely(rb->pg_vec))
3625                         goto out;
3626
3627                 switch (po->tp_version) {
3628                 case TPACKET_V1:
3629                         po->tp_hdrlen = TPACKET_HDRLEN;
3630                         break;
3631                 case TPACKET_V2:
3632                         po->tp_hdrlen = TPACKET2_HDRLEN;
3633                         break;
3634                 case TPACKET_V3:
3635                         po->tp_hdrlen = TPACKET3_HDRLEN;
3636                         break;
3637                 }
3638
3639                 err = -EINVAL;
3640                 if (unlikely((int)req->tp_block_size <= 0))
3641                         goto out;
3642                 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3643                         goto out;
3644                 if (po->tp_version >= TPACKET_V3 &&
3645                     (int)(req->tp_block_size -
3646                           BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
3647                         goto out;
3648                 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3649                                         po->tp_reserve))
3650                         goto out;
3651                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3652                         goto out;
3653
3654                 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3655                 if (unlikely(rb->frames_per_block <= 0))
3656                         goto out;
3657                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3658                                         req->tp_frame_nr))
3659                         goto out;
3660
3661                 err = -ENOMEM;
3662                 order = get_order(req->tp_block_size);
3663                 pg_vec = alloc_pg_vec(req, order);
3664                 if (unlikely(!pg_vec))
3665                         goto out;
3666                 switch (po->tp_version) {
3667                 case TPACKET_V3:
3668                 /* Transmit path is not supported. We checked
3669                  * it above but just being paranoid
3670                  */
3671                         if (!tx_ring)
3672                                 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3673                                 break;
3674                 default:
3675                         break;
3676                 }
3677         }
3678         /* Done */
3679         else {
3680                 err = -EINVAL;
3681                 if (unlikely(req->tp_frame_nr))
3682                         goto out;
3683         }
3684
3685         lock_sock(sk);
3686
3687         /* Detach socket from network */
3688         spin_lock(&po->bind_lock);
3689         was_running = po->running;
3690         num = po->num;
3691         if (was_running) {
3692                 po->num = 0;
3693                 __unregister_prot_hook(sk, false);
3694         }
3695         spin_unlock(&po->bind_lock);
3696
3697         synchronize_net();
3698
3699         err = -EBUSY;
3700         mutex_lock(&po->pg_vec_lock);
3701         if (closing || atomic_read(&po->mapped) == 0) {
3702                 err = 0;
3703                 spin_lock_bh(&rb_queue->lock);
3704                 swap(rb->pg_vec, pg_vec);
3705                 rb->frame_max = (req->tp_frame_nr - 1);
3706                 rb->head = 0;
3707                 rb->frame_size = req->tp_frame_size;
3708                 spin_unlock_bh(&rb_queue->lock);
3709
3710                 swap(rb->pg_vec_order, order);
3711                 swap(rb->pg_vec_len, req->tp_block_nr);
3712
3713                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3714                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3715                                                 tpacket_rcv : packet_rcv;
3716                 skb_queue_purge(rb_queue);
3717                 if (atomic_read(&po->mapped))
3718                         pr_err("packet_mmap: vma is busy: %d\n",
3719                                atomic_read(&po->mapped));
3720         }
3721         mutex_unlock(&po->pg_vec_lock);
3722
3723         spin_lock(&po->bind_lock);
3724         if (was_running) {
3725                 po->num = num;
3726                 register_prot_hook(sk);
3727         }
3728         spin_unlock(&po->bind_lock);
3729         if (closing && (po->tp_version > TPACKET_V2)) {
3730                 /* Because we don't support block-based V3 on tx-ring */
3731                 if (!tx_ring)
3732                         prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3733         }
3734         release_sock(sk);
3735
3736         if (pg_vec)
3737                 free_pg_vec(pg_vec, order, req->tp_block_nr);
3738 out:
3739         return err;
3740 }
3741
3742 static int packet_mmap(struct file *file, struct socket *sock,
3743                 struct vm_area_struct *vma)
3744 {
3745         struct sock *sk = sock->sk;
3746         struct packet_sock *po = pkt_sk(sk);
3747         unsigned long size, expected_size;
3748         struct packet_ring_buffer *rb;
3749         unsigned long start;
3750         int err = -EINVAL;
3751         int i;
3752
3753         if (vma->vm_pgoff)
3754                 return -EINVAL;
3755
3756         mutex_lock(&po->pg_vec_lock);
3757
3758         expected_size = 0;
3759         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3760                 if (rb->pg_vec) {
3761                         expected_size += rb->pg_vec_len
3762                                                 * rb->pg_vec_pages
3763                                                 * PAGE_SIZE;
3764                 }
3765         }
3766
3767         if (expected_size == 0)
3768                 goto out;
3769
3770         size = vma->vm_end - vma->vm_start;
3771         if (size != expected_size)
3772                 goto out;
3773
3774         start = vma->vm_start;
3775         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3776                 if (rb->pg_vec == NULL)
3777                         continue;
3778
3779                 for (i = 0; i < rb->pg_vec_len; i++) {
3780                         struct page *page;
3781                         void *kaddr = rb->pg_vec[i].buffer;
3782                         int pg_num;
3783
3784                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3785                                 page = pgv_to_page(kaddr);
3786                                 err = vm_insert_page(vma, start, page);
3787                                 if (unlikely(err))
3788                                         goto out;
3789                                 start += PAGE_SIZE;
3790                                 kaddr += PAGE_SIZE;
3791                         }
3792                 }
3793         }
3794
3795         atomic_inc(&po->mapped);
3796         vma->vm_ops = &packet_mmap_ops;
3797         err = 0;
3798
3799 out:
3800         mutex_unlock(&po->pg_vec_lock);
3801         return err;
3802 }
3803
3804 static const struct proto_ops packet_ops_spkt = {
3805         .family =       PF_PACKET,
3806         .owner =        THIS_MODULE,
3807         .release =      packet_release,
3808         .bind =         packet_bind_spkt,
3809         .connect =      sock_no_connect,
3810         .socketpair =   sock_no_socketpair,
3811         .accept =       sock_no_accept,
3812         .getname =      packet_getname_spkt,
3813         .poll =         datagram_poll,
3814         .ioctl =        packet_ioctl,
3815         .listen =       sock_no_listen,
3816         .shutdown =     sock_no_shutdown,
3817         .setsockopt =   sock_no_setsockopt,
3818         .getsockopt =   sock_no_getsockopt,
3819         .sendmsg =      packet_sendmsg_spkt,
3820         .recvmsg =      packet_recvmsg,
3821         .mmap =         sock_no_mmap,
3822         .sendpage =     sock_no_sendpage,
3823 };
3824
3825 static const struct proto_ops packet_ops = {
3826         .family =       PF_PACKET,
3827         .owner =        THIS_MODULE,
3828         .release =      packet_release,
3829         .bind =         packet_bind,
3830         .connect =      sock_no_connect,
3831         .socketpair =   sock_no_socketpair,
3832         .accept =       sock_no_accept,
3833         .getname =      packet_getname,
3834         .poll =         packet_poll,
3835         .ioctl =        packet_ioctl,
3836         .listen =       sock_no_listen,
3837         .shutdown =     sock_no_shutdown,
3838         .setsockopt =   packet_setsockopt,
3839         .getsockopt =   packet_getsockopt,
3840         .sendmsg =      packet_sendmsg,
3841         .recvmsg =      packet_recvmsg,
3842         .mmap =         packet_mmap,
3843         .sendpage =     sock_no_sendpage,
3844 };
3845
3846 static const struct net_proto_family packet_family_ops = {
3847         .family =       PF_PACKET,
3848         .create =       packet_create,
3849         .owner  =       THIS_MODULE,
3850 };
3851
3852 static struct notifier_block packet_netdev_notifier = {
3853         .notifier_call =        packet_notifier,
3854 };
3855
3856 #ifdef CONFIG_PROC_FS
3857
3858 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3859         __acquires(RCU)
3860 {
3861         struct net *net = seq_file_net(seq);
3862
3863         rcu_read_lock();
3864         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3865 }
3866
3867 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3868 {
3869         struct net *net = seq_file_net(seq);
3870         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3871 }
3872
3873 static void packet_seq_stop(struct seq_file *seq, void *v)
3874         __releases(RCU)
3875 {
3876         rcu_read_unlock();
3877 }
3878
3879 static int packet_seq_show(struct seq_file *seq, void *v)
3880 {
3881         if (v == SEQ_START_TOKEN)
3882                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
3883         else {
3884                 struct sock *s = sk_entry(v);
3885                 const struct packet_sock *po = pkt_sk(s);
3886
3887                 seq_printf(seq,
3888                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
3889                            s,
3890                            atomic_read(&s->sk_refcnt),
3891                            s->sk_type,
3892                            ntohs(po->num),
3893                            po->ifindex,
3894                            po->running,
3895                            atomic_read(&s->sk_rmem_alloc),
3896                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
3897                            sock_i_ino(s));
3898         }
3899
3900         return 0;
3901 }
3902
3903 static const struct seq_operations packet_seq_ops = {
3904         .start  = packet_seq_start,
3905         .next   = packet_seq_next,
3906         .stop   = packet_seq_stop,
3907         .show   = packet_seq_show,
3908 };
3909
3910 static int packet_seq_open(struct inode *inode, struct file *file)
3911 {
3912         return seq_open_net(inode, file, &packet_seq_ops,
3913                             sizeof(struct seq_net_private));
3914 }
3915
3916 static const struct file_operations packet_seq_fops = {
3917         .owner          = THIS_MODULE,
3918         .open           = packet_seq_open,
3919         .read           = seq_read,
3920         .llseek         = seq_lseek,
3921         .release        = seq_release_net,
3922 };
3923
3924 #endif
3925
3926 static int __net_init packet_net_init(struct net *net)
3927 {
3928         mutex_init(&net->packet.sklist_lock);
3929         INIT_HLIST_HEAD(&net->packet.sklist);
3930
3931         if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
3932                 return -ENOMEM;
3933
3934         return 0;
3935 }
3936
3937 static void __net_exit packet_net_exit(struct net *net)
3938 {
3939         remove_proc_entry("packet", net->proc_net);
3940 }
3941
3942 static struct pernet_operations packet_net_ops = {
3943         .init = packet_net_init,
3944         .exit = packet_net_exit,
3945 };
3946
3947
3948 static void __exit packet_exit(void)
3949 {
3950         unregister_netdevice_notifier(&packet_netdev_notifier);
3951         unregister_pernet_subsys(&packet_net_ops);
3952         sock_unregister(PF_PACKET);
3953         proto_unregister(&packet_proto);
3954 }
3955
3956 static int __init packet_init(void)
3957 {
3958         int rc = proto_register(&packet_proto, 0);
3959
3960         if (rc != 0)
3961                 goto out;
3962
3963         sock_register(&packet_family_ops);
3964         register_pernet_subsys(&packet_net_ops);
3965         register_netdevice_notifier(&packet_netdev_notifier);
3966 out:
3967         return rc;
3968 }
3969
3970 module_init(packet_init);
3971 module_exit(packet_exit);
3972 MODULE_LICENSE("GPL");
3973 MODULE_ALIAS_NETPROTO(PF_PACKET);