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 int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1154 {
1155         int x = atomic_read(&f->rr_cur) + 1;
1156
1157         if (x >= num)
1158                 x = 0;
1159
1160         return x;
1161 }
1162
1163 static unsigned int fanout_demux_hash(struct packet_fanout *f,
1164                                       struct sk_buff *skb,
1165                                       unsigned int num)
1166 {
1167         return (((u64)skb->rxhash) * num) >> 32;
1168 }
1169
1170 static unsigned int fanout_demux_lb(struct packet_fanout *f,
1171                                     struct sk_buff *skb,
1172                                     unsigned int num)
1173 {
1174         int cur, old;
1175
1176         cur = atomic_read(&f->rr_cur);
1177         while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1178                                      fanout_rr_next(f, num))) != cur)
1179                 cur = old;
1180         return cur;
1181 }
1182
1183 static unsigned int fanout_demux_cpu(struct packet_fanout *f,
1184                                      struct sk_buff *skb,
1185                                      unsigned int num)
1186 {
1187         return smp_processor_id() % num;
1188 }
1189
1190 static unsigned int fanout_demux_rollover(struct packet_fanout *f,
1191                                           struct sk_buff *skb,
1192                                           unsigned int idx, unsigned int skip,
1193                                           unsigned int num)
1194 {
1195         unsigned int i, j;
1196
1197         i = j = min_t(int, f->next[idx], num - 1);
1198         do {
1199                 if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) {
1200                         if (i != j)
1201                                 f->next[idx] = i;
1202                         return i;
1203                 }
1204                 if (++i == num)
1205                         i = 0;
1206         } while (i != j);
1207
1208         return idx;
1209 }
1210
1211 static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
1212 {
1213         return f->flags & (flag >> 8);
1214 }
1215
1216 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1217                              struct packet_type *pt, struct net_device *orig_dev)
1218 {
1219         struct packet_fanout *f = pt->af_packet_priv;
1220         unsigned int num = f->num_members;
1221         struct packet_sock *po;
1222         unsigned int idx;
1223
1224         if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1225             !num) {
1226                 kfree_skb(skb);
1227                 return 0;
1228         }
1229
1230         switch (f->type) {
1231         case PACKET_FANOUT_HASH:
1232         default:
1233                 if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
1234                         skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1235                         if (!skb)
1236                                 return 0;
1237                 }
1238                 skb_get_rxhash(skb);
1239                 idx = fanout_demux_hash(f, skb, num);
1240                 break;
1241         case PACKET_FANOUT_LB:
1242                 idx = fanout_demux_lb(f, skb, num);
1243                 break;
1244         case PACKET_FANOUT_CPU:
1245                 idx = fanout_demux_cpu(f, skb, num);
1246                 break;
1247         case PACKET_FANOUT_ROLLOVER:
1248                 idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num);
1249                 break;
1250         }
1251
1252         po = pkt_sk(f->arr[idx]);
1253         if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) &&
1254             unlikely(!packet_rcv_has_room(po, skb))) {
1255                 idx = fanout_demux_rollover(f, skb, idx, idx, num);
1256                 po = pkt_sk(f->arr[idx]);
1257         }
1258
1259         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1260 }
1261
1262 DEFINE_MUTEX(fanout_mutex);
1263 EXPORT_SYMBOL_GPL(fanout_mutex);
1264 static LIST_HEAD(fanout_list);
1265
1266 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1267 {
1268         struct packet_fanout *f = po->fanout;
1269
1270         spin_lock(&f->lock);
1271         f->arr[f->num_members] = sk;
1272         smp_wmb();
1273         f->num_members++;
1274         spin_unlock(&f->lock);
1275 }
1276
1277 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1278 {
1279         struct packet_fanout *f = po->fanout;
1280         int i;
1281
1282         spin_lock(&f->lock);
1283         for (i = 0; i < f->num_members; i++) {
1284                 if (f->arr[i] == sk)
1285                         break;
1286         }
1287         BUG_ON(i >= f->num_members);
1288         f->arr[i] = f->arr[f->num_members - 1];
1289         f->num_members--;
1290         spin_unlock(&f->lock);
1291 }
1292
1293 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk)
1294 {
1295         if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout)
1296                 return true;
1297
1298         return false;
1299 }
1300
1301 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1302 {
1303         struct packet_sock *po = pkt_sk(sk);
1304         struct packet_fanout *f, *match;
1305         u8 type = type_flags & 0xff;
1306         u8 flags = type_flags >> 8;
1307         int err;
1308
1309         switch (type) {
1310         case PACKET_FANOUT_ROLLOVER:
1311                 if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
1312                         return -EINVAL;
1313         case PACKET_FANOUT_HASH:
1314         case PACKET_FANOUT_LB:
1315         case PACKET_FANOUT_CPU:
1316                 break;
1317         default:
1318                 return -EINVAL;
1319         }
1320
1321         if (!po->running)
1322                 return -EINVAL;
1323
1324         if (po->fanout)
1325                 return -EALREADY;
1326
1327         mutex_lock(&fanout_mutex);
1328         match = NULL;
1329         list_for_each_entry(f, &fanout_list, list) {
1330                 if (f->id == id &&
1331                     read_pnet(&f->net) == sock_net(sk)) {
1332                         match = f;
1333                         break;
1334                 }
1335         }
1336         err = -EINVAL;
1337         if (match && match->flags != flags)
1338                 goto out;
1339         if (!match) {
1340                 err = -ENOMEM;
1341                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1342                 if (!match)
1343                         goto out;
1344                 write_pnet(&match->net, sock_net(sk));
1345                 match->id = id;
1346                 match->type = type;
1347                 match->flags = flags;
1348                 atomic_set(&match->rr_cur, 0);
1349                 INIT_LIST_HEAD(&match->list);
1350                 spin_lock_init(&match->lock);
1351                 atomic_set(&match->sk_ref, 0);
1352                 match->prot_hook.type = po->prot_hook.type;
1353                 match->prot_hook.dev = po->prot_hook.dev;
1354                 match->prot_hook.func = packet_rcv_fanout;
1355                 match->prot_hook.af_packet_priv = match;
1356                 match->prot_hook.id_match = match_fanout_group;
1357                 dev_add_pack(&match->prot_hook);
1358                 list_add(&match->list, &fanout_list);
1359         }
1360         err = -EINVAL;
1361         if (match->type == type &&
1362             match->prot_hook.type == po->prot_hook.type &&
1363             match->prot_hook.dev == po->prot_hook.dev) {
1364                 err = -ENOSPC;
1365                 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1366                         __dev_remove_pack(&po->prot_hook);
1367                         po->fanout = match;
1368                         atomic_inc(&match->sk_ref);
1369                         __fanout_link(sk, po);
1370                         err = 0;
1371                 }
1372         }
1373 out:
1374         mutex_unlock(&fanout_mutex);
1375         return err;
1376 }
1377
1378 static void fanout_release(struct sock *sk)
1379 {
1380         struct packet_sock *po = pkt_sk(sk);
1381         struct packet_fanout *f;
1382
1383         f = po->fanout;
1384         if (!f)
1385                 return;
1386
1387         mutex_lock(&fanout_mutex);
1388         po->fanout = NULL;
1389
1390         if (atomic_dec_and_test(&f->sk_ref)) {
1391                 list_del(&f->list);
1392                 dev_remove_pack(&f->prot_hook);
1393                 kfree(f);
1394         }
1395         mutex_unlock(&fanout_mutex);
1396 }
1397
1398 static const struct proto_ops packet_ops;
1399
1400 static const struct proto_ops packet_ops_spkt;
1401
1402 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1403                            struct packet_type *pt, struct net_device *orig_dev)
1404 {
1405         struct sock *sk;
1406         struct sockaddr_pkt *spkt;
1407
1408         /*
1409          *      When we registered the protocol we saved the socket in the data
1410          *      field for just this event.
1411          */
1412
1413         sk = pt->af_packet_priv;
1414
1415         /*
1416          *      Yank back the headers [hope the device set this
1417          *      right or kerboom...]
1418          *
1419          *      Incoming packets have ll header pulled,
1420          *      push it back.
1421          *
1422          *      For outgoing ones skb->data == skb_mac_header(skb)
1423          *      so that this procedure is noop.
1424          */
1425
1426         if (skb->pkt_type == PACKET_LOOPBACK)
1427                 goto out;
1428
1429         if (!net_eq(dev_net(dev), sock_net(sk)))
1430                 goto out;
1431
1432         skb = skb_share_check(skb, GFP_ATOMIC);
1433         if (skb == NULL)
1434                 goto oom;
1435
1436         /* drop any routing info */
1437         skb_dst_drop(skb);
1438
1439         /* drop conntrack reference */
1440         nf_reset(skb);
1441
1442         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1443
1444         skb_push(skb, skb->data - skb_mac_header(skb));
1445
1446         /*
1447          *      The SOCK_PACKET socket receives _all_ frames.
1448          */
1449
1450         spkt->spkt_family = dev->type;
1451         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1452         spkt->spkt_protocol = skb->protocol;
1453
1454         /*
1455          *      Charge the memory to the socket. This is done specifically
1456          *      to prevent sockets using all the memory up.
1457          */
1458
1459         if (sock_queue_rcv_skb(sk, skb) == 0)
1460                 return 0;
1461
1462 out:
1463         kfree_skb(skb);
1464 oom:
1465         return 0;
1466 }
1467
1468
1469 /*
1470  *      Output a raw packet to a device layer. This bypasses all the other
1471  *      protocol layers and you must therefore supply it with a complete frame
1472  */
1473
1474 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1475                                struct msghdr *msg, size_t len)
1476 {
1477         struct sock *sk = sock->sk;
1478         struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1479         struct sk_buff *skb = NULL;
1480         struct net_device *dev;
1481         __be16 proto = 0;
1482         int err;
1483         int extra_len = 0;
1484
1485         /*
1486          *      Get and verify the address.
1487          */
1488
1489         if (saddr) {
1490                 if (msg->msg_namelen < sizeof(struct sockaddr))
1491                         return -EINVAL;
1492                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1493                         proto = saddr->spkt_protocol;
1494         } else
1495                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1496
1497         /*
1498          *      Find the device first to size check it
1499          */
1500
1501         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1502 retry:
1503         rcu_read_lock();
1504         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1505         err = -ENODEV;
1506         if (dev == NULL)
1507                 goto out_unlock;
1508
1509         err = -ENETDOWN;
1510         if (!(dev->flags & IFF_UP))
1511                 goto out_unlock;
1512
1513         /*
1514          * You may not queue a frame bigger than the mtu. This is the lowest level
1515          * raw protocol and you must do your own fragmentation at this level.
1516          */
1517
1518         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1519                 if (!netif_supports_nofcs(dev)) {
1520                         err = -EPROTONOSUPPORT;
1521                         goto out_unlock;
1522                 }
1523                 extra_len = 4; /* We're doing our own CRC */
1524         }
1525
1526         err = -EMSGSIZE;
1527         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1528                 goto out_unlock;
1529
1530         if (!skb) {
1531                 size_t reserved = LL_RESERVED_SPACE(dev);
1532                 int tlen = dev->needed_tailroom;
1533                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1534
1535                 rcu_read_unlock();
1536                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1537                 if (skb == NULL)
1538                         return -ENOBUFS;
1539                 /* FIXME: Save some space for broken drivers that write a hard
1540                  * header at transmission time by themselves. PPP is the notable
1541                  * one here. This should really be fixed at the driver level.
1542                  */
1543                 skb_reserve(skb, reserved);
1544                 skb_reset_network_header(skb);
1545
1546                 /* Try to align data part correctly */
1547                 if (hhlen) {
1548                         skb->data -= hhlen;
1549                         skb->tail -= hhlen;
1550                         if (len < hhlen)
1551                                 skb_reset_network_header(skb);
1552                 }
1553                 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1554                 if (err)
1555                         goto out_free;
1556                 goto retry;
1557         }
1558
1559         if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1560                 /* Earlier code assumed this would be a VLAN pkt,
1561                  * double-check this now that we have the actual
1562                  * packet in hand.
1563                  */
1564                 struct ethhdr *ehdr;
1565                 skb_reset_mac_header(skb);
1566                 ehdr = eth_hdr(skb);
1567                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1568                         err = -EMSGSIZE;
1569                         goto out_unlock;
1570                 }
1571         }
1572
1573         skb->protocol = proto;
1574         skb->dev = dev;
1575         skb->priority = sk->sk_priority;
1576         skb->mark = sk->sk_mark;
1577
1578         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1579
1580         if (unlikely(extra_len == 4))
1581                 skb->no_fcs = 1;
1582
1583         skb_probe_transport_header(skb, 0);
1584
1585         dev_queue_xmit(skb);
1586         rcu_read_unlock();
1587         return len;
1588
1589 out_unlock:
1590         rcu_read_unlock();
1591 out_free:
1592         kfree_skb(skb);
1593         return err;
1594 }
1595
1596 static unsigned int run_filter(const struct sk_buff *skb,
1597                                       const struct sock *sk,
1598                                       unsigned int res)
1599 {
1600         struct sk_filter *filter;
1601
1602         rcu_read_lock();
1603         filter = rcu_dereference(sk->sk_filter);
1604         if (filter != NULL)
1605                 res = SK_RUN_FILTER(filter, skb);
1606         rcu_read_unlock();
1607
1608         return res;
1609 }
1610
1611 /*
1612  * This function makes lazy skb cloning in hope that most of packets
1613  * are discarded by BPF.
1614  *
1615  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1616  * and skb->cb are mangled. It works because (and until) packets
1617  * falling here are owned by current CPU. Output packets are cloned
1618  * by dev_queue_xmit_nit(), input packets are processed by net_bh
1619  * sequencially, so that if we return skb to original state on exit,
1620  * we will not harm anyone.
1621  */
1622
1623 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1624                       struct packet_type *pt, struct net_device *orig_dev)
1625 {
1626         struct sock *sk;
1627         struct sockaddr_ll *sll;
1628         struct packet_sock *po;
1629         u8 *skb_head = skb->data;
1630         int skb_len = skb->len;
1631         unsigned int snaplen, res;
1632
1633         if (skb->pkt_type == PACKET_LOOPBACK)
1634                 goto drop;
1635
1636         sk = pt->af_packet_priv;
1637         po = pkt_sk(sk);
1638
1639         if (!net_eq(dev_net(dev), sock_net(sk)))
1640                 goto drop;
1641
1642         skb->dev = dev;
1643
1644         if (dev->header_ops) {
1645                 /* The device has an explicit notion of ll header,
1646                  * exported to higher levels.
1647                  *
1648                  * Otherwise, the device hides details of its frame
1649                  * structure, so that corresponding packet head is
1650                  * never delivered to user.
1651                  */
1652                 if (sk->sk_type != SOCK_DGRAM)
1653                         skb_push(skb, skb->data - skb_mac_header(skb));
1654                 else if (skb->pkt_type == PACKET_OUTGOING) {
1655                         /* Special case: outgoing packets have ll header at head */
1656                         skb_pull(skb, skb_network_offset(skb));
1657                 }
1658         }
1659
1660         snaplen = skb->len;
1661
1662         res = run_filter(skb, sk, snaplen);
1663         if (!res)
1664                 goto drop_n_restore;
1665         if (snaplen > res)
1666                 snaplen = res;
1667
1668         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1669                 goto drop_n_acct;
1670
1671         if (skb_shared(skb)) {
1672                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1673                 if (nskb == NULL)
1674                         goto drop_n_acct;
1675
1676                 if (skb_head != skb->data) {
1677                         skb->data = skb_head;
1678                         skb->len = skb_len;
1679                 }
1680                 consume_skb(skb);
1681                 skb = nskb;
1682         }
1683
1684         BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1685                      sizeof(skb->cb));
1686
1687         sll = &PACKET_SKB_CB(skb)->sa.ll;
1688         sll->sll_family = AF_PACKET;
1689         sll->sll_hatype = dev->type;
1690         sll->sll_protocol = skb->protocol;
1691         sll->sll_pkttype = skb->pkt_type;
1692         if (unlikely(po->origdev))
1693                 sll->sll_ifindex = orig_dev->ifindex;
1694         else
1695                 sll->sll_ifindex = dev->ifindex;
1696
1697         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1698
1699         PACKET_SKB_CB(skb)->origlen = skb->len;
1700
1701         if (pskb_trim(skb, snaplen))
1702                 goto drop_n_acct;
1703
1704         skb_set_owner_r(skb, sk);
1705         skb->dev = NULL;
1706         skb_dst_drop(skb);
1707
1708         /* drop conntrack reference */
1709         nf_reset(skb);
1710
1711         spin_lock(&sk->sk_receive_queue.lock);
1712         po->stats.stats1.tp_packets++;
1713         skb->dropcount = atomic_read(&sk->sk_drops);
1714         __skb_queue_tail(&sk->sk_receive_queue, skb);
1715         spin_unlock(&sk->sk_receive_queue.lock);
1716         sk->sk_data_ready(sk, skb->len);
1717         return 0;
1718
1719 drop_n_acct:
1720         spin_lock(&sk->sk_receive_queue.lock);
1721         po->stats.stats1.tp_drops++;
1722         atomic_inc(&sk->sk_drops);
1723         spin_unlock(&sk->sk_receive_queue.lock);
1724
1725 drop_n_restore:
1726         if (skb_head != skb->data && skb_shared(skb)) {
1727                 skb->data = skb_head;
1728                 skb->len = skb_len;
1729         }
1730 drop:
1731         consume_skb(skb);
1732         return 0;
1733 }
1734
1735 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1736                        struct packet_type *pt, struct net_device *orig_dev)
1737 {
1738         struct sock *sk;
1739         struct packet_sock *po;
1740         struct sockaddr_ll *sll;
1741         union tpacket_uhdr h;
1742         u8 *skb_head = skb->data;
1743         int skb_len = skb->len;
1744         unsigned int snaplen, res;
1745         unsigned long status = TP_STATUS_USER;
1746         unsigned short macoff, netoff, hdrlen;
1747         struct sk_buff *copy_skb = NULL;
1748         struct timespec ts;
1749         __u32 ts_status;
1750
1751         if (skb->pkt_type == PACKET_LOOPBACK)
1752                 goto drop;
1753
1754         sk = pt->af_packet_priv;
1755         po = pkt_sk(sk);
1756
1757         if (!net_eq(dev_net(dev), sock_net(sk)))
1758                 goto drop;
1759
1760         if (dev->header_ops) {
1761                 if (sk->sk_type != SOCK_DGRAM)
1762                         skb_push(skb, skb->data - skb_mac_header(skb));
1763                 else if (skb->pkt_type == PACKET_OUTGOING) {
1764                         /* Special case: outgoing packets have ll header at head */
1765                         skb_pull(skb, skb_network_offset(skb));
1766                 }
1767         }
1768
1769         if (skb->ip_summed == CHECKSUM_PARTIAL)
1770                 status |= TP_STATUS_CSUMNOTREADY;
1771
1772         snaplen = skb->len;
1773
1774         res = run_filter(skb, sk, snaplen);
1775         if (!res)
1776                 goto drop_n_restore;
1777         if (snaplen > res)
1778                 snaplen = res;
1779
1780         if (sk->sk_type == SOCK_DGRAM) {
1781                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1782                                   po->tp_reserve;
1783         } else {
1784                 unsigned int maclen = skb_network_offset(skb);
1785                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1786                                        (maclen < 16 ? 16 : maclen)) +
1787                         po->tp_reserve;
1788                 macoff = netoff - maclen;
1789         }
1790         if (po->tp_version <= TPACKET_V2) {
1791                 if (macoff + snaplen > po->rx_ring.frame_size) {
1792                         if (po->copy_thresh &&
1793                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1794                                 if (skb_shared(skb)) {
1795                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
1796                                 } else {
1797                                         copy_skb = skb_get(skb);
1798                                         skb_head = skb->data;
1799                                 }
1800                                 if (copy_skb)
1801                                         skb_set_owner_r(copy_skb, sk);
1802                         }
1803                         snaplen = po->rx_ring.frame_size - macoff;
1804                         if ((int)snaplen < 0)
1805                                 snaplen = 0;
1806                 }
1807         } else if (unlikely(macoff + snaplen >
1808                             GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
1809                 u32 nval;
1810
1811                 nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
1812                 pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
1813                             snaplen, nval, macoff);
1814                 snaplen = nval;
1815                 if (unlikely((int)snaplen < 0)) {
1816                         snaplen = 0;
1817                         macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
1818                 }
1819         }
1820         spin_lock(&sk->sk_receive_queue.lock);
1821         h.raw = packet_current_rx_frame(po, skb,
1822                                         TP_STATUS_KERNEL, (macoff+snaplen));
1823         if (!h.raw)
1824                 goto ring_is_full;
1825         if (po->tp_version <= TPACKET_V2) {
1826                 packet_increment_rx_head(po, &po->rx_ring);
1827         /*
1828          * LOSING will be reported till you read the stats,
1829          * because it's COR - Clear On Read.
1830          * Anyways, moving it for V1/V2 only as V3 doesn't need this
1831          * at packet level.
1832          */
1833                 if (po->stats.stats1.tp_drops)
1834                         status |= TP_STATUS_LOSING;
1835         }
1836         po->stats.stats1.tp_packets++;
1837         if (copy_skb) {
1838                 status |= TP_STATUS_COPY;
1839                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1840         }
1841         spin_unlock(&sk->sk_receive_queue.lock);
1842
1843         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1844
1845         if (!(ts_status = tpacket_get_timestamp(skb, &ts, po->tp_tstamp)))
1846                 getnstimeofday(&ts);
1847
1848         status |= ts_status;
1849
1850         switch (po->tp_version) {
1851         case TPACKET_V1:
1852                 h.h1->tp_len = skb->len;
1853                 h.h1->tp_snaplen = snaplen;
1854                 h.h1->tp_mac = macoff;
1855                 h.h1->tp_net = netoff;
1856                 h.h1->tp_sec = ts.tv_sec;
1857                 h.h1->tp_usec = ts.tv_nsec / NSEC_PER_USEC;
1858                 hdrlen = sizeof(*h.h1);
1859                 break;
1860         case TPACKET_V2:
1861                 h.h2->tp_len = skb->len;
1862                 h.h2->tp_snaplen = snaplen;
1863                 h.h2->tp_mac = macoff;
1864                 h.h2->tp_net = netoff;
1865                 h.h2->tp_sec = ts.tv_sec;
1866                 h.h2->tp_nsec = ts.tv_nsec;
1867                 if (vlan_tx_tag_present(skb)) {
1868                         h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1869                         status |= TP_STATUS_VLAN_VALID;
1870                 } else {
1871                         h.h2->tp_vlan_tci = 0;
1872                 }
1873                 h.h2->tp_padding = 0;
1874                 hdrlen = sizeof(*h.h2);
1875                 break;
1876         case TPACKET_V3:
1877                 /* tp_nxt_offset,vlan are already populated above.
1878                  * So DONT clear those fields here
1879                  */
1880                 h.h3->tp_status |= status;
1881                 h.h3->tp_len = skb->len;
1882                 h.h3->tp_snaplen = snaplen;
1883                 h.h3->tp_mac = macoff;
1884                 h.h3->tp_net = netoff;
1885                 h.h3->tp_sec  = ts.tv_sec;
1886                 h.h3->tp_nsec = ts.tv_nsec;
1887                 hdrlen = sizeof(*h.h3);
1888                 break;
1889         default:
1890                 BUG();
1891         }
1892
1893         sll = h.raw + TPACKET_ALIGN(hdrlen);
1894         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1895         sll->sll_family = AF_PACKET;
1896         sll->sll_hatype = dev->type;
1897         sll->sll_protocol = skb->protocol;
1898         sll->sll_pkttype = skb->pkt_type;
1899         if (unlikely(po->origdev))
1900                 sll->sll_ifindex = orig_dev->ifindex;
1901         else
1902                 sll->sll_ifindex = dev->ifindex;
1903
1904         smp_mb();
1905 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1906         {
1907                 u8 *start, *end;
1908
1909                 if (po->tp_version <= TPACKET_V2) {
1910                         end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1911                                 + macoff + snaplen);
1912                         for (start = h.raw; start < end; start += PAGE_SIZE)
1913                                 flush_dcache_page(pgv_to_page(start));
1914                 }
1915                 smp_wmb();
1916         }
1917 #endif
1918         if (po->tp_version <= TPACKET_V2)
1919                 __packet_set_status(po, h.raw, status);
1920         else
1921                 prb_clear_blk_fill_status(&po->rx_ring);
1922
1923         sk->sk_data_ready(sk, 0);
1924
1925 drop_n_restore:
1926         if (skb_head != skb->data && skb_shared(skb)) {
1927                 skb->data = skb_head;
1928                 skb->len = skb_len;
1929         }
1930 drop:
1931         kfree_skb(skb);
1932         return 0;
1933
1934 ring_is_full:
1935         po->stats.stats1.tp_drops++;
1936         spin_unlock(&sk->sk_receive_queue.lock);
1937
1938         sk->sk_data_ready(sk, 0);
1939         kfree_skb(copy_skb);
1940         goto drop_n_restore;
1941 }
1942
1943 static void tpacket_destruct_skb(struct sk_buff *skb)
1944 {
1945         struct packet_sock *po = pkt_sk(skb->sk);
1946         void *ph;
1947
1948         if (likely(po->tx_ring.pg_vec)) {
1949                 __u32 ts;
1950
1951                 ph = skb_shinfo(skb)->destructor_arg;
1952                 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1953                 atomic_dec(&po->tx_ring.pending);
1954
1955                 ts = __packet_set_timestamp(po, ph, skb);
1956                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE | ts);
1957         }
1958
1959         sock_wfree(skb);
1960 }
1961
1962 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1963                 void *frame, struct net_device *dev, int size_max,
1964                 __be16 proto, unsigned char *addr, int hlen)
1965 {
1966         union tpacket_uhdr ph;
1967         int to_write, offset, len, tp_len, nr_frags, len_max;
1968         struct socket *sock = po->sk.sk_socket;
1969         struct page *page;
1970         void *data;
1971         int err;
1972
1973         ph.raw = frame;
1974
1975         skb->protocol = proto;
1976         skb->dev = dev;
1977         skb->priority = po->sk.sk_priority;
1978         skb->mark = po->sk.sk_mark;
1979         sock_tx_timestamp(&po->sk, &skb_shinfo(skb)->tx_flags);
1980         skb_shinfo(skb)->destructor_arg = ph.raw;
1981
1982         switch (po->tp_version) {
1983         case TPACKET_V2:
1984                 tp_len = ph.h2->tp_len;
1985                 break;
1986         default:
1987                 tp_len = ph.h1->tp_len;
1988                 break;
1989         }
1990         if (unlikely(tp_len > size_max)) {
1991                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1992                 return -EMSGSIZE;
1993         }
1994
1995         skb_reserve(skb, hlen);
1996         skb_reset_network_header(skb);
1997         skb_probe_transport_header(skb, 0);
1998
1999         if (po->tp_tx_has_off) {
2000                 int off_min, off_max, off;
2001                 off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll);
2002                 off_max = po->tx_ring.frame_size - tp_len;
2003                 if (sock->type == SOCK_DGRAM) {
2004                         switch (po->tp_version) {
2005                         case TPACKET_V2:
2006                                 off = ph.h2->tp_net;
2007                                 break;
2008                         default:
2009                                 off = ph.h1->tp_net;
2010                                 break;
2011                         }
2012                 } else {
2013                         switch (po->tp_version) {
2014                         case TPACKET_V2:
2015                                 off = ph.h2->tp_mac;
2016                                 break;
2017                         default:
2018                                 off = ph.h1->tp_mac;
2019                                 break;
2020                         }
2021                 }
2022                 if (unlikely((off < off_min) || (off_max < off)))
2023                         return -EINVAL;
2024                 data = ph.raw + off;
2025         } else {
2026                 data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
2027         }
2028         to_write = tp_len;
2029
2030         if (sock->type == SOCK_DGRAM) {
2031                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
2032                                 NULL, tp_len);
2033                 if (unlikely(err < 0))
2034                         return -EINVAL;
2035         } else if (dev->hard_header_len) {
2036                 /* net device doesn't like empty head */
2037                 if (unlikely(tp_len <= dev->hard_header_len)) {
2038                         pr_err("packet size is too short (%d < %d)\n",
2039                                tp_len, dev->hard_header_len);
2040                         return -EINVAL;
2041                 }
2042
2043                 skb_push(skb, dev->hard_header_len);
2044                 err = skb_store_bits(skb, 0, data,
2045                                 dev->hard_header_len);
2046                 if (unlikely(err))
2047                         return err;
2048
2049                 data += dev->hard_header_len;
2050                 to_write -= dev->hard_header_len;
2051         }
2052
2053         offset = offset_in_page(data);
2054         len_max = PAGE_SIZE - offset;
2055         len = ((to_write > len_max) ? len_max : to_write);
2056
2057         skb->data_len = to_write;
2058         skb->len += to_write;
2059         skb->truesize += to_write;
2060         atomic_add(to_write, &po->sk.sk_wmem_alloc);
2061
2062         while (likely(to_write)) {
2063                 nr_frags = skb_shinfo(skb)->nr_frags;
2064
2065                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2066                         pr_err("Packet exceed the number of skb frags(%lu)\n",
2067                                MAX_SKB_FRAGS);
2068                         return -EFAULT;
2069                 }
2070
2071                 page = pgv_to_page(data);
2072                 data += len;
2073                 flush_dcache_page(page);
2074                 get_page(page);
2075                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
2076                 to_write -= len;
2077                 offset = 0;
2078                 len_max = PAGE_SIZE;
2079                 len = ((to_write > len_max) ? len_max : to_write);
2080         }
2081
2082         return tp_len;
2083 }
2084
2085 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2086 {
2087         struct sk_buff *skb;
2088         struct net_device *dev;
2089         __be16 proto;
2090         int err, reserve = 0;
2091         void *ph;
2092         struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2093         int tp_len, size_max;
2094         unsigned char *addr;
2095         int len_sum = 0;
2096         int status = TP_STATUS_AVAILABLE;
2097         int hlen, tlen;
2098
2099         mutex_lock(&po->pg_vec_lock);
2100
2101         if (likely(saddr == NULL)) {
2102                 dev     = packet_cached_dev_get(po);
2103                 proto   = po->num;
2104                 addr    = NULL;
2105         } else {
2106                 err = -EINVAL;
2107                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2108                         goto out;
2109                 if (msg->msg_namelen < (saddr->sll_halen
2110                                         + offsetof(struct sockaddr_ll,
2111                                                 sll_addr)))
2112                         goto out;
2113                 proto   = saddr->sll_protocol;
2114                 addr    = saddr->sll_addr;
2115                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2116         }
2117
2118         err = -ENXIO;
2119         if (unlikely(dev == NULL))
2120                 goto out;
2121         err = -ENETDOWN;
2122         if (unlikely(!(dev->flags & IFF_UP)))
2123                 goto out_put;
2124
2125         reserve = dev->hard_header_len;
2126
2127         size_max = po->tx_ring.frame_size
2128                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2129
2130         if (size_max > dev->mtu + reserve)
2131                 size_max = dev->mtu + reserve;
2132
2133         do {
2134                 ph = packet_current_frame(po, &po->tx_ring,
2135                                 TP_STATUS_SEND_REQUEST);
2136
2137                 if (unlikely(ph == NULL)) {
2138                         schedule();
2139                         continue;
2140                 }
2141
2142                 status = TP_STATUS_SEND_REQUEST;
2143                 hlen = LL_RESERVED_SPACE(dev);
2144                 tlen = dev->needed_tailroom;
2145                 skb = sock_alloc_send_skb(&po->sk,
2146                                 hlen + tlen + sizeof(struct sockaddr_ll),
2147                                 0, &err);
2148
2149                 if (unlikely(skb == NULL))
2150                         goto out_status;
2151
2152                 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2153                                 addr, hlen);
2154
2155                 if (unlikely(tp_len < 0)) {
2156                         if (po->tp_loss) {
2157                                 __packet_set_status(po, ph,
2158                                                 TP_STATUS_AVAILABLE);
2159                                 packet_increment_head(&po->tx_ring);
2160                                 kfree_skb(skb);
2161                                 continue;
2162                         } else {
2163                                 status = TP_STATUS_WRONG_FORMAT;
2164                                 err = tp_len;
2165                                 goto out_status;
2166                         }
2167                 }
2168
2169                 skb->destructor = tpacket_destruct_skb;
2170                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2171                 atomic_inc(&po->tx_ring.pending);
2172
2173                 status = TP_STATUS_SEND_REQUEST;
2174                 err = dev_queue_xmit(skb);
2175                 if (unlikely(err > 0)) {
2176                         err = net_xmit_errno(err);
2177                         if (err && __packet_get_status(po, ph) ==
2178                                    TP_STATUS_AVAILABLE) {
2179                                 /* skb was destructed already */
2180                                 skb = NULL;
2181                                 goto out_status;
2182                         }
2183                         /*
2184                          * skb was dropped but not destructed yet;
2185                          * let's treat it like congestion or err < 0
2186                          */
2187                         err = 0;
2188                 }
2189                 packet_increment_head(&po->tx_ring);
2190                 len_sum += tp_len;
2191         } while (likely((ph != NULL) ||
2192                         ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2193                          (atomic_read(&po->tx_ring.pending))))
2194                 );
2195
2196         err = len_sum;
2197         goto out_put;
2198
2199 out_status:
2200         __packet_set_status(po, ph, status);
2201         kfree_skb(skb);
2202 out_put:
2203         dev_put(dev);
2204 out:
2205         mutex_unlock(&po->pg_vec_lock);
2206         return err;
2207 }
2208
2209 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2210                                         size_t reserve, size_t len,
2211                                         size_t linear, int noblock,
2212                                         int *err)
2213 {
2214         struct sk_buff *skb;
2215
2216         /* Under a page?  Don't bother with paged skb. */
2217         if (prepad + len < PAGE_SIZE || !linear)
2218                 linear = len;
2219
2220         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2221                                    err);
2222         if (!skb)
2223                 return NULL;
2224
2225         skb_reserve(skb, reserve);
2226         skb_put(skb, linear);
2227         skb->data_len = len - linear;
2228         skb->len += len - linear;
2229
2230         return skb;
2231 }
2232
2233 static int packet_snd(struct socket *sock,
2234                           struct msghdr *msg, size_t len)
2235 {
2236         struct sock *sk = sock->sk;
2237         struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2238         struct sk_buff *skb;
2239         struct net_device *dev;
2240         __be16 proto;
2241         unsigned char *addr;
2242         int err, reserve = 0;
2243         struct virtio_net_hdr vnet_hdr = { 0 };
2244         int offset = 0;
2245         int vnet_hdr_len;
2246         struct packet_sock *po = pkt_sk(sk);
2247         unsigned short gso_type = 0;
2248         int hlen, tlen;
2249         int extra_len = 0;
2250
2251         /*
2252          *      Get and verify the address.
2253          */
2254
2255         if (likely(saddr == NULL)) {
2256                 dev     = packet_cached_dev_get(po);
2257                 proto   = po->num;
2258                 addr    = NULL;
2259         } else {
2260                 err = -EINVAL;
2261                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2262                         goto out;
2263                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2264                         goto out;
2265                 proto   = saddr->sll_protocol;
2266                 addr    = saddr->sll_addr;
2267                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2268         }
2269
2270         err = -ENXIO;
2271         if (unlikely(dev == NULL))
2272                 goto out_unlock;
2273         err = -ENETDOWN;
2274         if (unlikely(!(dev->flags & IFF_UP)))
2275                 goto out_unlock;
2276
2277         if (sock->type == SOCK_RAW)
2278                 reserve = dev->hard_header_len;
2279         if (po->has_vnet_hdr) {
2280                 vnet_hdr_len = sizeof(vnet_hdr);
2281
2282                 err = -EINVAL;
2283                 if (len < vnet_hdr_len)
2284                         goto out_unlock;
2285
2286                 len -= vnet_hdr_len;
2287
2288                 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2289                                        vnet_hdr_len);
2290                 if (err < 0)
2291                         goto out_unlock;
2292
2293                 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2294                     (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2295                       vnet_hdr.hdr_len))
2296                         vnet_hdr.hdr_len = vnet_hdr.csum_start +
2297                                                  vnet_hdr.csum_offset + 2;
2298
2299                 err = -EINVAL;
2300                 if (vnet_hdr.hdr_len > len)
2301                         goto out_unlock;
2302
2303                 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2304                         switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2305                         case VIRTIO_NET_HDR_GSO_TCPV4:
2306                                 gso_type = SKB_GSO_TCPV4;
2307                                 break;
2308                         case VIRTIO_NET_HDR_GSO_TCPV6:
2309                                 gso_type = SKB_GSO_TCPV6;
2310                                 break;
2311                         case VIRTIO_NET_HDR_GSO_UDP:
2312                                 gso_type = SKB_GSO_UDP;
2313                                 break;
2314                         default:
2315                                 goto out_unlock;
2316                         }
2317
2318                         if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2319                                 gso_type |= SKB_GSO_TCP_ECN;
2320
2321                         if (vnet_hdr.gso_size == 0)
2322                                 goto out_unlock;
2323
2324                 }
2325         }
2326
2327         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2328                 if (!netif_supports_nofcs(dev)) {
2329                         err = -EPROTONOSUPPORT;
2330                         goto out_unlock;
2331                 }
2332                 extra_len = 4; /* We're doing our own CRC */
2333         }
2334
2335         err = -EMSGSIZE;
2336         if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2337                 goto out_unlock;
2338
2339         err = -ENOBUFS;
2340         hlen = LL_RESERVED_SPACE(dev);
2341         tlen = dev->needed_tailroom;
2342         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2343                                msg->msg_flags & MSG_DONTWAIT, &err);
2344         if (skb == NULL)
2345                 goto out_unlock;
2346
2347         skb_set_network_header(skb, reserve);
2348
2349         err = -EINVAL;
2350         if (sock->type == SOCK_DGRAM &&
2351             (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2352                 goto out_free;
2353
2354         /* Returns -EFAULT on error */
2355         err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2356         if (err)
2357                 goto out_free;
2358
2359         sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2360
2361         if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2362                 /* Earlier code assumed this would be a VLAN pkt,
2363                  * double-check this now that we have the actual
2364                  * packet in hand.
2365                  */
2366                 struct ethhdr *ehdr;
2367                 skb_reset_mac_header(skb);
2368                 ehdr = eth_hdr(skb);
2369                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2370                         err = -EMSGSIZE;
2371                         goto out_free;
2372                 }
2373         }
2374
2375         skb->protocol = proto;
2376         skb->dev = dev;
2377         skb->priority = sk->sk_priority;
2378         skb->mark = sk->sk_mark;
2379
2380         if (po->has_vnet_hdr) {
2381                 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2382                         if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2383                                                   vnet_hdr.csum_offset)) {
2384                                 err = -EINVAL;
2385                                 goto out_free;
2386                         }
2387                 }
2388
2389                 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2390                 skb_shinfo(skb)->gso_type = gso_type;
2391
2392                 /* Header must be checked, and gso_segs computed. */
2393                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2394                 skb_shinfo(skb)->gso_segs = 0;
2395
2396                 len += vnet_hdr_len;
2397         }
2398
2399         skb_probe_transport_header(skb, reserve);
2400
2401         if (unlikely(extra_len == 4))
2402                 skb->no_fcs = 1;
2403
2404         /*
2405          *      Now send it
2406          */
2407
2408         err = dev_queue_xmit(skb);
2409         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2410                 goto out_unlock;
2411
2412         dev_put(dev);
2413
2414         return len;
2415
2416 out_free:
2417         kfree_skb(skb);
2418 out_unlock:
2419         if (dev)
2420                 dev_put(dev);
2421 out:
2422         return err;
2423 }
2424
2425 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2426                 struct msghdr *msg, size_t len)
2427 {
2428         struct sock *sk = sock->sk;
2429         struct packet_sock *po = pkt_sk(sk);
2430         if (po->tx_ring.pg_vec)
2431                 return tpacket_snd(po, msg);
2432         else
2433                 return packet_snd(sock, msg, len);
2434 }
2435
2436 /*
2437  *      Close a PACKET socket. This is fairly simple. We immediately go
2438  *      to 'closed' state and remove our protocol entry in the device list.
2439  */
2440
2441 static int packet_release(struct socket *sock)
2442 {
2443         struct sock *sk = sock->sk;
2444         struct packet_sock *po;
2445         struct net *net;
2446         union tpacket_req_u req_u;
2447
2448         if (!sk)
2449                 return 0;
2450
2451         net = sock_net(sk);
2452         po = pkt_sk(sk);
2453
2454         mutex_lock(&net->packet.sklist_lock);
2455         sk_del_node_init_rcu(sk);
2456         mutex_unlock(&net->packet.sklist_lock);
2457
2458         preempt_disable();
2459         sock_prot_inuse_add(net, sk->sk_prot, -1);
2460         preempt_enable();
2461
2462         spin_lock(&po->bind_lock);
2463         unregister_prot_hook(sk, false);
2464         packet_cached_dev_reset(po);
2465
2466         if (po->prot_hook.dev) {
2467                 dev_put(po->prot_hook.dev);
2468                 po->prot_hook.dev = NULL;
2469         }
2470         spin_unlock(&po->bind_lock);
2471
2472         packet_flush_mclist(sk);
2473
2474         if (po->rx_ring.pg_vec) {
2475                 memset(&req_u, 0, sizeof(req_u));
2476                 packet_set_ring(sk, &req_u, 1, 0);
2477         }
2478
2479         if (po->tx_ring.pg_vec) {
2480                 memset(&req_u, 0, sizeof(req_u));
2481                 packet_set_ring(sk, &req_u, 1, 1);
2482         }
2483
2484         fanout_release(sk);
2485
2486         synchronize_net();
2487         /*
2488          *      Now the socket is dead. No more input will appear.
2489          */
2490         sock_orphan(sk);
2491         sock->sk = NULL;
2492
2493         /* Purge queues */
2494
2495         skb_queue_purge(&sk->sk_receive_queue);
2496         sk_refcnt_debug_release(sk);
2497
2498         sock_put(sk);
2499         return 0;
2500 }
2501
2502 /*
2503  *      Attach a packet hook.
2504  */
2505
2506 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2507 {
2508         struct packet_sock *po = pkt_sk(sk);
2509
2510         if (po->fanout) {
2511                 if (dev)
2512                         dev_put(dev);
2513
2514                 return -EINVAL;
2515         }
2516
2517         lock_sock(sk);
2518
2519         spin_lock(&po->bind_lock);
2520         unregister_prot_hook(sk, true);
2521
2522         po->num = protocol;
2523         po->prot_hook.type = protocol;
2524         if (po->prot_hook.dev)
2525                 dev_put(po->prot_hook.dev);
2526
2527         po->prot_hook.dev = dev;
2528         po->ifindex = dev ? dev->ifindex : 0;
2529
2530         packet_cached_dev_assign(po, dev);
2531
2532         if (protocol == 0)
2533                 goto out_unlock;
2534
2535         if (!dev || (dev->flags & IFF_UP)) {
2536                 register_prot_hook(sk);
2537         } else {
2538                 sk->sk_err = ENETDOWN;
2539                 if (!sock_flag(sk, SOCK_DEAD))
2540                         sk->sk_error_report(sk);
2541         }
2542
2543 out_unlock:
2544         spin_unlock(&po->bind_lock);
2545         release_sock(sk);
2546         return 0;
2547 }
2548
2549 /*
2550  *      Bind a packet socket to a device
2551  */
2552
2553 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2554                             int addr_len)
2555 {
2556         struct sock *sk = sock->sk;
2557         char name[15];
2558         struct net_device *dev;
2559         int err = -ENODEV;
2560
2561         /*
2562          *      Check legality
2563          */
2564
2565         if (addr_len != sizeof(struct sockaddr))
2566                 return -EINVAL;
2567         strlcpy(name, uaddr->sa_data, sizeof(name));
2568
2569         dev = dev_get_by_name(sock_net(sk), name);
2570         if (dev)
2571                 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2572         return err;
2573 }
2574
2575 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2576 {
2577         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2578         struct sock *sk = sock->sk;
2579         struct net_device *dev = NULL;
2580         int err;
2581
2582
2583         /*
2584          *      Check legality
2585          */
2586
2587         if (addr_len < sizeof(struct sockaddr_ll))
2588                 return -EINVAL;
2589         if (sll->sll_family != AF_PACKET)
2590                 return -EINVAL;
2591
2592         if (sll->sll_ifindex) {
2593                 err = -ENODEV;
2594                 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2595                 if (dev == NULL)
2596                         goto out;
2597         }
2598         err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2599
2600 out:
2601         return err;
2602 }
2603
2604 static struct proto packet_proto = {
2605         .name     = "PACKET",
2606         .owner    = THIS_MODULE,
2607         .obj_size = sizeof(struct packet_sock),
2608 };
2609
2610 /*
2611  *      Create a packet of type SOCK_PACKET.
2612  */
2613
2614 static int packet_create(struct net *net, struct socket *sock, int protocol,
2615                          int kern)
2616 {
2617         struct sock *sk;
2618         struct packet_sock *po;
2619         __be16 proto = (__force __be16)protocol; /* weird, but documented */
2620         int err;
2621
2622         if (!ns_capable(net->user_ns, CAP_NET_RAW))
2623                 return -EPERM;
2624         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2625             sock->type != SOCK_PACKET)
2626                 return -ESOCKTNOSUPPORT;
2627
2628         sock->state = SS_UNCONNECTED;
2629
2630         err = -ENOBUFS;
2631         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2632         if (sk == NULL)
2633                 goto out;
2634
2635         sock->ops = &packet_ops;
2636         if (sock->type == SOCK_PACKET)
2637                 sock->ops = &packet_ops_spkt;
2638
2639         sock_init_data(sock, sk);
2640
2641         po = pkt_sk(sk);
2642         sk->sk_family = PF_PACKET;
2643         po->num = proto;
2644
2645         packet_cached_dev_reset(po);
2646
2647         sk->sk_destruct = packet_sock_destruct;
2648         sk_refcnt_debug_inc(sk);
2649
2650         /*
2651          *      Attach a protocol block
2652          */
2653
2654         spin_lock_init(&po->bind_lock);
2655         mutex_init(&po->pg_vec_lock);
2656         po->prot_hook.func = packet_rcv;
2657
2658         if (sock->type == SOCK_PACKET)
2659                 po->prot_hook.func = packet_rcv_spkt;
2660
2661         po->prot_hook.af_packet_priv = sk;
2662
2663         if (proto) {
2664                 po->prot_hook.type = proto;
2665                 register_prot_hook(sk);
2666         }
2667
2668         mutex_lock(&net->packet.sklist_lock);
2669         sk_add_node_rcu(sk, &net->packet.sklist);
2670         mutex_unlock(&net->packet.sklist_lock);
2671
2672         preempt_disable();
2673         sock_prot_inuse_add(net, &packet_proto, 1);
2674         preempt_enable();
2675
2676         return 0;
2677 out:
2678         return err;
2679 }
2680
2681 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
2682 {
2683         struct sock_exterr_skb *serr;
2684         struct sk_buff *skb, *skb2;
2685         int copied, err;
2686
2687         err = -EAGAIN;
2688         skb = skb_dequeue(&sk->sk_error_queue);
2689         if (skb == NULL)
2690                 goto out;
2691
2692         copied = skb->len;
2693         if (copied > len) {
2694                 msg->msg_flags |= MSG_TRUNC;
2695                 copied = len;
2696         }
2697         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2698         if (err)
2699                 goto out_free_skb;
2700
2701         sock_recv_timestamp(msg, sk, skb);
2702
2703         serr = SKB_EXT_ERR(skb);
2704         put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP,
2705                  sizeof(serr->ee), &serr->ee);
2706
2707         msg->msg_flags |= MSG_ERRQUEUE;
2708         err = copied;
2709
2710         /* Reset and regenerate socket error */
2711         spin_lock_bh(&sk->sk_error_queue.lock);
2712         sk->sk_err = 0;
2713         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2714                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2715                 spin_unlock_bh(&sk->sk_error_queue.lock);
2716                 sk->sk_error_report(sk);
2717         } else
2718                 spin_unlock_bh(&sk->sk_error_queue.lock);
2719
2720 out_free_skb:
2721         kfree_skb(skb);
2722 out:
2723         return err;
2724 }
2725
2726 /*
2727  *      Pull a packet from our receive queue and hand it to the user.
2728  *      If necessary we block.
2729  */
2730
2731 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2732                           struct msghdr *msg, size_t len, int flags)
2733 {
2734         struct sock *sk = sock->sk;
2735         struct sk_buff *skb;
2736         int copied, err;
2737         int vnet_hdr_len = 0;
2738
2739         err = -EINVAL;
2740         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2741                 goto out;
2742
2743 #if 0
2744         /* What error should we return now? EUNATTACH? */
2745         if (pkt_sk(sk)->ifindex < 0)
2746                 return -ENODEV;
2747 #endif
2748
2749         if (flags & MSG_ERRQUEUE) {
2750                 err = packet_recv_error(sk, msg, len);
2751                 goto out;
2752         }
2753
2754         /*
2755          *      Call the generic datagram receiver. This handles all sorts
2756          *      of horrible races and re-entrancy so we can forget about it
2757          *      in the protocol layers.
2758          *
2759          *      Now it will return ENETDOWN, if device have just gone down,
2760          *      but then it will block.
2761          */
2762
2763         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2764
2765         /*
2766          *      An error occurred so return it. Because skb_recv_datagram()
2767          *      handles the blocking we don't see and worry about blocking
2768          *      retries.
2769          */
2770
2771         if (skb == NULL)
2772                 goto out;
2773
2774         if (pkt_sk(sk)->has_vnet_hdr) {
2775                 struct virtio_net_hdr vnet_hdr = { 0 };
2776
2777                 err = -EINVAL;
2778                 vnet_hdr_len = sizeof(vnet_hdr);
2779                 if (len < vnet_hdr_len)
2780                         goto out_free;
2781
2782                 len -= vnet_hdr_len;
2783
2784                 if (skb_is_gso(skb)) {
2785                         struct skb_shared_info *sinfo = skb_shinfo(skb);
2786
2787                         /* This is a hint as to how much should be linear. */
2788                         vnet_hdr.hdr_len = skb_headlen(skb);
2789                         vnet_hdr.gso_size = sinfo->gso_size;
2790                         if (sinfo->gso_type & SKB_GSO_TCPV4)
2791                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2792                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
2793                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2794                         else if (sinfo->gso_type & SKB_GSO_UDP)
2795                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2796                         else if (sinfo->gso_type & SKB_GSO_FCOE)
2797                                 goto out_free;
2798                         else
2799                                 BUG();
2800                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2801                                 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2802                 } else
2803                         vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2804
2805                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2806                         vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2807                         vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2808                         vnet_hdr.csum_offset = skb->csum_offset;
2809                 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2810                         vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2811                 } /* else everything is zero */
2812
2813                 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2814                                      vnet_hdr_len);
2815                 if (err < 0)
2816                         goto out_free;
2817         }
2818
2819         /* You lose any data beyond the buffer you gave. If it worries
2820          * a user program they can ask the device for its MTU
2821          * anyway.
2822          */
2823         copied = skb->len;
2824         if (copied > len) {
2825                 copied = len;
2826                 msg->msg_flags |= MSG_TRUNC;
2827         }
2828
2829         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2830         if (err)
2831                 goto out_free;
2832
2833         sock_recv_ts_and_drops(msg, sk, skb);
2834
2835         if (msg->msg_name) {
2836                 /* If the address length field is there to be filled
2837                  * in, we fill it in now.
2838                  */
2839                 if (sock->type == SOCK_PACKET) {
2840                         msg->msg_namelen = sizeof(struct sockaddr_pkt);
2841                 } else {
2842                         struct sockaddr_ll *sll = &PACKET_SKB_CB(skb)->sa.ll;
2843                         msg->msg_namelen = sll->sll_halen +
2844                                 offsetof(struct sockaddr_ll, sll_addr);
2845                 }
2846                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2847                        msg->msg_namelen);
2848         }
2849
2850         if (pkt_sk(sk)->auxdata) {
2851                 struct tpacket_auxdata aux;
2852
2853                 aux.tp_status = TP_STATUS_USER;
2854                 if (skb->ip_summed == CHECKSUM_PARTIAL)
2855                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2856                 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2857                 aux.tp_snaplen = skb->len;
2858                 aux.tp_mac = 0;
2859                 aux.tp_net = skb_network_offset(skb);
2860                 if (vlan_tx_tag_present(skb)) {
2861                         aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2862                         aux.tp_status |= TP_STATUS_VLAN_VALID;
2863                 } else {
2864                         aux.tp_vlan_tci = 0;
2865                 }
2866                 aux.tp_padding = 0;
2867                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2868         }
2869
2870         /*
2871          *      Free or return the buffer as appropriate. Again this
2872          *      hides all the races and re-entrancy issues from us.
2873          */
2874         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2875
2876 out_free:
2877         skb_free_datagram(sk, skb);
2878 out:
2879         return err;
2880 }
2881
2882 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2883                                int *uaddr_len, int peer)
2884 {
2885         struct net_device *dev;
2886         struct sock *sk = sock->sk;
2887
2888         if (peer)
2889                 return -EOPNOTSUPP;
2890
2891         uaddr->sa_family = AF_PACKET;
2892         memset(uaddr->sa_data, 0, sizeof(uaddr->sa_data));
2893         rcu_read_lock();
2894         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2895         if (dev)
2896                 strlcpy(uaddr->sa_data, dev->name, sizeof(uaddr->sa_data));
2897         rcu_read_unlock();
2898         *uaddr_len = sizeof(*uaddr);
2899
2900         return 0;
2901 }
2902
2903 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2904                           int *uaddr_len, int peer)
2905 {
2906         struct net_device *dev;
2907         struct sock *sk = sock->sk;
2908         struct packet_sock *po = pkt_sk(sk);
2909         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2910
2911         if (peer)
2912                 return -EOPNOTSUPP;
2913
2914         sll->sll_family = AF_PACKET;
2915         sll->sll_ifindex = po->ifindex;
2916         sll->sll_protocol = po->num;
2917         sll->sll_pkttype = 0;
2918         rcu_read_lock();
2919         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2920         if (dev) {
2921                 sll->sll_hatype = dev->type;
2922                 sll->sll_halen = dev->addr_len;
2923                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2924         } else {
2925                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
2926                 sll->sll_halen = 0;
2927         }
2928         rcu_read_unlock();
2929         *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2930
2931         return 0;
2932 }
2933
2934 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2935                          int what)
2936 {
2937         switch (i->type) {
2938         case PACKET_MR_MULTICAST:
2939                 if (i->alen != dev->addr_len)
2940                         return -EINVAL;
2941                 if (what > 0)
2942                         return dev_mc_add(dev, i->addr);
2943                 else
2944                         return dev_mc_del(dev, i->addr);
2945                 break;
2946         case PACKET_MR_PROMISC:
2947                 return dev_set_promiscuity(dev, what);
2948                 break;
2949         case PACKET_MR_ALLMULTI:
2950                 return dev_set_allmulti(dev, what);
2951                 break;
2952         case PACKET_MR_UNICAST:
2953                 if (i->alen != dev->addr_len)
2954                         return -EINVAL;
2955                 if (what > 0)
2956                         return dev_uc_add(dev, i->addr);
2957                 else
2958                         return dev_uc_del(dev, i->addr);
2959                 break;
2960         default:
2961                 break;
2962         }
2963         return 0;
2964 }
2965
2966 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2967 {
2968         for ( ; i; i = i->next) {
2969                 if (i->ifindex == dev->ifindex)
2970                         packet_dev_mc(dev, i, what);
2971         }
2972 }
2973
2974 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2975 {
2976         struct packet_sock *po = pkt_sk(sk);
2977         struct packet_mclist *ml, *i;
2978         struct net_device *dev;
2979         int err;
2980
2981         rtnl_lock();
2982
2983         err = -ENODEV;
2984         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2985         if (!dev)
2986                 goto done;
2987
2988         err = -EINVAL;
2989         if (mreq->mr_alen > dev->addr_len)
2990                 goto done;
2991
2992         err = -ENOBUFS;
2993         i = kmalloc(sizeof(*i), GFP_KERNEL);
2994         if (i == NULL)
2995                 goto done;
2996
2997         err = 0;
2998         for (ml = po->mclist; ml; ml = ml->next) {
2999                 if (ml->ifindex == mreq->mr_ifindex &&
3000                     ml->type == mreq->mr_type &&
3001                     ml->alen == mreq->mr_alen &&
3002                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3003                         ml->count++;
3004                         /* Free the new element ... */
3005                         kfree(i);
3006                         goto done;
3007                 }
3008         }
3009
3010         i->type = mreq->mr_type;
3011         i->ifindex = mreq->mr_ifindex;
3012         i->alen = mreq->mr_alen;
3013         memcpy(i->addr, mreq->mr_address, i->alen);
3014         i->count = 1;
3015         i->next = po->mclist;
3016         po->mclist = i;
3017         err = packet_dev_mc(dev, i, 1);
3018         if (err) {
3019                 po->mclist = i->next;
3020                 kfree(i);
3021         }
3022
3023 done:
3024         rtnl_unlock();
3025         return err;
3026 }
3027
3028 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
3029 {
3030         struct packet_mclist *ml, **mlp;
3031
3032         rtnl_lock();
3033
3034         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3035                 if (ml->ifindex == mreq->mr_ifindex &&
3036                     ml->type == mreq->mr_type &&
3037                     ml->alen == mreq->mr_alen &&
3038                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3039                         if (--ml->count == 0) {
3040                                 struct net_device *dev;
3041                                 *mlp = ml->next;
3042                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3043                                 if (dev)
3044                                         packet_dev_mc(dev, ml, -1);
3045                                 kfree(ml);
3046                         }
3047                         rtnl_unlock();
3048                         return 0;
3049                 }
3050         }
3051         rtnl_unlock();
3052         return -EADDRNOTAVAIL;
3053 }
3054
3055 static void packet_flush_mclist(struct sock *sk)
3056 {
3057         struct packet_sock *po = pkt_sk(sk);
3058         struct packet_mclist *ml;
3059
3060         if (!po->mclist)
3061                 return;
3062
3063         rtnl_lock();
3064         while ((ml = po->mclist) != NULL) {
3065                 struct net_device *dev;
3066
3067                 po->mclist = ml->next;
3068                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3069                 if (dev != NULL)
3070                         packet_dev_mc(dev, ml, -1);
3071                 kfree(ml);
3072         }
3073         rtnl_unlock();
3074 }
3075
3076 static int
3077 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3078 {
3079         struct sock *sk = sock->sk;
3080         struct packet_sock *po = pkt_sk(sk);
3081         int ret;
3082
3083         if (level != SOL_PACKET)
3084                 return -ENOPROTOOPT;
3085
3086         switch (optname) {
3087         case PACKET_ADD_MEMBERSHIP:
3088         case PACKET_DROP_MEMBERSHIP:
3089         {
3090                 struct packet_mreq_max mreq;
3091                 int len = optlen;
3092                 memset(&mreq, 0, sizeof(mreq));
3093                 if (len < sizeof(struct packet_mreq))
3094                         return -EINVAL;
3095                 if (len > sizeof(mreq))
3096                         len = sizeof(mreq);
3097                 if (copy_from_user(&mreq, optval, len))
3098                         return -EFAULT;
3099                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3100                         return -EINVAL;
3101                 if (optname == PACKET_ADD_MEMBERSHIP)
3102                         ret = packet_mc_add(sk, &mreq);
3103                 else
3104                         ret = packet_mc_drop(sk, &mreq);
3105                 return ret;
3106         }
3107
3108         case PACKET_RX_RING:
3109         case PACKET_TX_RING:
3110         {
3111                 union tpacket_req_u req_u;
3112                 int len;
3113
3114                 switch (po->tp_version) {
3115                 case TPACKET_V1:
3116                 case TPACKET_V2:
3117                         len = sizeof(req_u.req);
3118                         break;
3119                 case TPACKET_V3:
3120                 default:
3121                         len = sizeof(req_u.req3);
3122                         break;
3123                 }
3124                 if (optlen < len)
3125                         return -EINVAL;
3126                 if (pkt_sk(sk)->has_vnet_hdr)
3127                         return -EINVAL;
3128                 if (copy_from_user(&req_u.req, optval, len))
3129                         return -EFAULT;
3130                 return packet_set_ring(sk, &req_u, 0,
3131                         optname == PACKET_TX_RING);
3132         }
3133         case PACKET_COPY_THRESH:
3134         {
3135                 int val;
3136
3137                 if (optlen != sizeof(val))
3138                         return -EINVAL;
3139                 if (copy_from_user(&val, optval, sizeof(val)))
3140                         return -EFAULT;
3141
3142                 pkt_sk(sk)->copy_thresh = val;
3143                 return 0;
3144         }
3145         case PACKET_VERSION:
3146         {
3147                 int val;
3148
3149                 if (optlen != sizeof(val))
3150                         return -EINVAL;
3151                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3152                         return -EBUSY;
3153                 if (copy_from_user(&val, optval, sizeof(val)))
3154                         return -EFAULT;
3155                 switch (val) {
3156                 case TPACKET_V1:
3157                 case TPACKET_V2:
3158                 case TPACKET_V3:
3159                         po->tp_version = val;
3160                         return 0;
3161                 default:
3162                         return -EINVAL;
3163                 }
3164         }
3165         case PACKET_RESERVE:
3166         {
3167                 unsigned int val;
3168
3169                 if (optlen != sizeof(val))
3170                         return -EINVAL;
3171                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3172                         return -EBUSY;
3173                 if (copy_from_user(&val, optval, sizeof(val)))
3174                         return -EFAULT;
3175                 po->tp_reserve = val;
3176                 return 0;
3177         }
3178         case PACKET_LOSS:
3179         {
3180                 unsigned int val;
3181
3182                 if (optlen != sizeof(val))
3183                         return -EINVAL;
3184                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3185                         return -EBUSY;
3186                 if (copy_from_user(&val, optval, sizeof(val)))
3187                         return -EFAULT;
3188                 po->tp_loss = !!val;
3189                 return 0;
3190         }
3191         case PACKET_AUXDATA:
3192         {
3193                 int val;
3194
3195                 if (optlen < sizeof(val))
3196                         return -EINVAL;
3197                 if (copy_from_user(&val, optval, sizeof(val)))
3198                         return -EFAULT;
3199
3200                 po->auxdata = !!val;
3201                 return 0;
3202         }
3203         case PACKET_ORIGDEV:
3204         {
3205                 int val;
3206
3207                 if (optlen < sizeof(val))
3208                         return -EINVAL;
3209                 if (copy_from_user(&val, optval, sizeof(val)))
3210                         return -EFAULT;
3211
3212                 po->origdev = !!val;
3213                 return 0;
3214         }
3215         case PACKET_VNET_HDR:
3216         {
3217                 int val;
3218
3219                 if (sock->type != SOCK_RAW)
3220                         return -EINVAL;
3221                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3222                         return -EBUSY;
3223                 if (optlen < sizeof(val))
3224                         return -EINVAL;
3225                 if (copy_from_user(&val, optval, sizeof(val)))
3226                         return -EFAULT;
3227
3228                 po->has_vnet_hdr = !!val;
3229                 return 0;
3230         }
3231         case PACKET_TIMESTAMP:
3232         {
3233                 int val;
3234
3235                 if (optlen != sizeof(val))
3236                         return -EINVAL;
3237                 if (copy_from_user(&val, optval, sizeof(val)))
3238                         return -EFAULT;
3239
3240                 po->tp_tstamp = val;
3241                 return 0;
3242         }
3243         case PACKET_FANOUT:
3244         {
3245                 int val;
3246
3247                 if (optlen != sizeof(val))
3248                         return -EINVAL;
3249                 if (copy_from_user(&val, optval, sizeof(val)))
3250                         return -EFAULT;
3251
3252                 return fanout_add(sk, val & 0xffff, val >> 16);
3253         }
3254         case PACKET_TX_HAS_OFF:
3255         {
3256                 unsigned int val;
3257
3258                 if (optlen != sizeof(val))
3259                         return -EINVAL;
3260                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3261                         return -EBUSY;
3262                 if (copy_from_user(&val, optval, sizeof(val)))
3263                         return -EFAULT;
3264                 po->tp_tx_has_off = !!val;
3265                 return 0;
3266         }
3267         default:
3268                 return -ENOPROTOOPT;
3269         }
3270 }
3271
3272 static int packet_getsockopt(struct socket *sock, int level, int optname,
3273                              char __user *optval, int __user *optlen)
3274 {
3275         int len;
3276         int val, lv = sizeof(val);
3277         struct sock *sk = sock->sk;
3278         struct packet_sock *po = pkt_sk(sk);
3279         void *data = &val;
3280         union tpacket_stats_u st;
3281
3282         if (level != SOL_PACKET)
3283                 return -ENOPROTOOPT;
3284
3285         if (get_user(len, optlen))
3286                 return -EFAULT;
3287
3288         if (len < 0)
3289                 return -EINVAL;
3290
3291         switch (optname) {
3292         case PACKET_STATISTICS:
3293                 spin_lock_bh(&sk->sk_receive_queue.lock);
3294                 memcpy(&st, &po->stats, sizeof(st));
3295                 memset(&po->stats, 0, sizeof(po->stats));
3296                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3297
3298                 if (po->tp_version == TPACKET_V3) {
3299                         lv = sizeof(struct tpacket_stats_v3);
3300                         st.stats3.tp_packets += st.stats3.tp_drops;
3301                         data = &st.stats3;
3302                 } else {
3303                         lv = sizeof(struct tpacket_stats);
3304                         st.stats1.tp_packets += st.stats1.tp_drops;
3305                         data = &st.stats1;
3306                 }
3307
3308                 break;
3309         case PACKET_AUXDATA:
3310                 val = po->auxdata;
3311                 break;
3312         case PACKET_ORIGDEV:
3313                 val = po->origdev;
3314                 break;
3315         case PACKET_VNET_HDR:
3316                 val = po->has_vnet_hdr;
3317                 break;
3318         case PACKET_VERSION:
3319                 val = po->tp_version;
3320                 break;
3321         case PACKET_HDRLEN:
3322                 if (len > sizeof(int))
3323                         len = sizeof(int);
3324                 if (copy_from_user(&val, optval, len))
3325                         return -EFAULT;
3326                 switch (val) {
3327                 case TPACKET_V1:
3328                         val = sizeof(struct tpacket_hdr);
3329                         break;
3330                 case TPACKET_V2:
3331                         val = sizeof(struct tpacket2_hdr);
3332                         break;
3333                 case TPACKET_V3:
3334                         val = sizeof(struct tpacket3_hdr);
3335                         break;
3336                 default:
3337                         return -EINVAL;
3338                 }
3339                 break;
3340         case PACKET_RESERVE:
3341                 val = po->tp_reserve;
3342                 break;
3343         case PACKET_LOSS:
3344                 val = po->tp_loss;
3345                 break;
3346         case PACKET_TIMESTAMP:
3347                 val = po->tp_tstamp;
3348                 break;
3349         case PACKET_FANOUT:
3350                 val = (po->fanout ?
3351                        ((u32)po->fanout->id |
3352                         ((u32)po->fanout->type << 16) |
3353                         ((u32)po->fanout->flags << 24)) :
3354                        0);
3355                 break;
3356         case PACKET_TX_HAS_OFF:
3357                 val = po->tp_tx_has_off;
3358                 break;
3359         default:
3360                 return -ENOPROTOOPT;
3361         }
3362
3363         if (len > lv)
3364                 len = lv;
3365         if (put_user(len, optlen))
3366                 return -EFAULT;
3367         if (copy_to_user(optval, data, len))
3368                 return -EFAULT;
3369         return 0;
3370 }
3371
3372
3373 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
3374 {
3375         struct sock *sk;
3376         struct net_device *dev = data;
3377         struct net *net = dev_net(dev);
3378
3379         rcu_read_lock();
3380         sk_for_each_rcu(sk, &net->packet.sklist) {
3381                 struct packet_sock *po = pkt_sk(sk);
3382
3383                 switch (msg) {
3384                 case NETDEV_UNREGISTER:
3385                         if (po->mclist)
3386                                 packet_dev_mclist(dev, po->mclist, -1);
3387                         /* fallthrough */
3388
3389                 case NETDEV_DOWN:
3390                         if (dev->ifindex == po->ifindex) {
3391                                 spin_lock(&po->bind_lock);
3392                                 if (po->running) {
3393                                         __unregister_prot_hook(sk, false);
3394                                         sk->sk_err = ENETDOWN;
3395                                         if (!sock_flag(sk, SOCK_DEAD))
3396                                                 sk->sk_error_report(sk);
3397                                 }
3398                                 if (msg == NETDEV_UNREGISTER) {
3399                                         packet_cached_dev_reset(po);
3400                                         po->ifindex = -1;
3401                                         if (po->prot_hook.dev)
3402                                                 dev_put(po->prot_hook.dev);
3403                                         po->prot_hook.dev = NULL;
3404                                 }
3405                                 spin_unlock(&po->bind_lock);
3406                         }
3407                         break;
3408                 case NETDEV_UP:
3409                         if (dev->ifindex == po->ifindex) {
3410                                 spin_lock(&po->bind_lock);
3411                                 if (po->num)
3412                                         register_prot_hook(sk);
3413                                 spin_unlock(&po->bind_lock);
3414                         }
3415                         break;
3416                 }
3417         }
3418         rcu_read_unlock();
3419         return NOTIFY_DONE;
3420 }
3421
3422
3423 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3424                         unsigned long arg)
3425 {
3426         struct sock *sk = sock->sk;
3427
3428         switch (cmd) {
3429         case SIOCOUTQ:
3430         {
3431                 int amount = sk_wmem_alloc_get(sk);
3432
3433                 return put_user(amount, (int __user *)arg);
3434         }
3435         case SIOCINQ:
3436         {
3437                 struct sk_buff *skb;
3438                 int amount = 0;
3439
3440                 spin_lock_bh(&sk->sk_receive_queue.lock);
3441                 skb = skb_peek(&sk->sk_receive_queue);
3442                 if (skb)
3443                         amount = skb->len;
3444                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3445                 return put_user(amount, (int __user *)arg);
3446         }
3447         case SIOCGSTAMP:
3448                 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3449         case SIOCGSTAMPNS:
3450                 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3451
3452 #ifdef CONFIG_INET
3453         case SIOCADDRT:
3454         case SIOCDELRT:
3455         case SIOCDARP:
3456         case SIOCGARP:
3457         case SIOCSARP:
3458         case SIOCGIFADDR:
3459         case SIOCSIFADDR:
3460         case SIOCGIFBRDADDR:
3461         case SIOCSIFBRDADDR:
3462         case SIOCGIFNETMASK:
3463         case SIOCSIFNETMASK:
3464         case SIOCGIFDSTADDR:
3465         case SIOCSIFDSTADDR:
3466         case SIOCSIFFLAGS:
3467                 return inet_dgram_ops.ioctl(sock, cmd, arg);
3468 #endif
3469
3470         default:
3471                 return -ENOIOCTLCMD;
3472         }
3473         return 0;
3474 }
3475
3476 static unsigned int packet_poll(struct file *file, struct socket *sock,
3477                                 poll_table *wait)
3478 {
3479         struct sock *sk = sock->sk;
3480         struct packet_sock *po = pkt_sk(sk);
3481         unsigned int mask = datagram_poll(file, sock, wait);
3482
3483         spin_lock_bh(&sk->sk_receive_queue.lock);
3484         if (po->rx_ring.pg_vec) {
3485                 if (!packet_previous_rx_frame(po, &po->rx_ring,
3486                         TP_STATUS_KERNEL))
3487                         mask |= POLLIN | POLLRDNORM;
3488         }
3489         spin_unlock_bh(&sk->sk_receive_queue.lock);
3490         spin_lock_bh(&sk->sk_write_queue.lock);
3491         if (po->tx_ring.pg_vec) {
3492                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3493                         mask |= POLLOUT | POLLWRNORM;
3494         }
3495         spin_unlock_bh(&sk->sk_write_queue.lock);
3496         return mask;
3497 }
3498
3499
3500 /* Dirty? Well, I still did not learn better way to account
3501  * for user mmaps.
3502  */
3503
3504 static void packet_mm_open(struct vm_area_struct *vma)
3505 {
3506         struct file *file = vma->vm_file;
3507         struct socket *sock = file->private_data;
3508         struct sock *sk = sock->sk;
3509
3510         if (sk)
3511                 atomic_inc(&pkt_sk(sk)->mapped);
3512 }
3513
3514 static void packet_mm_close(struct vm_area_struct *vma)
3515 {
3516         struct file *file = vma->vm_file;
3517         struct socket *sock = file->private_data;
3518         struct sock *sk = sock->sk;
3519
3520         if (sk)
3521                 atomic_dec(&pkt_sk(sk)->mapped);
3522 }
3523
3524 static const struct vm_operations_struct packet_mmap_ops = {
3525         .open   =       packet_mm_open,
3526         .close  =       packet_mm_close,
3527 };
3528
3529 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3530                         unsigned int len)
3531 {
3532         int i;
3533
3534         for (i = 0; i < len; i++) {
3535                 if (likely(pg_vec[i].buffer)) {
3536                         if (is_vmalloc_addr(pg_vec[i].buffer))
3537                                 vfree(pg_vec[i].buffer);
3538                         else
3539                                 free_pages((unsigned long)pg_vec[i].buffer,
3540                                            order);
3541                         pg_vec[i].buffer = NULL;
3542                 }
3543         }
3544         kfree(pg_vec);
3545 }
3546
3547 static char *alloc_one_pg_vec_page(unsigned long order)
3548 {
3549         char *buffer = NULL;
3550         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3551                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3552
3553         buffer = (char *) __get_free_pages(gfp_flags, order);
3554
3555         if (buffer)
3556                 return buffer;
3557
3558         /*
3559          * __get_free_pages failed, fall back to vmalloc
3560          */
3561         buffer = vzalloc((1 << order) * PAGE_SIZE);
3562
3563         if (buffer)
3564                 return buffer;
3565
3566         /*
3567          * vmalloc failed, lets dig into swap here
3568          */
3569         gfp_flags &= ~__GFP_NORETRY;
3570         buffer = (char *)__get_free_pages(gfp_flags, order);
3571         if (buffer)
3572                 return buffer;
3573
3574         /*
3575          * complete and utter failure
3576          */
3577         return NULL;
3578 }
3579
3580 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3581 {
3582         unsigned int block_nr = req->tp_block_nr;
3583         struct pgv *pg_vec;
3584         int i;
3585
3586         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3587         if (unlikely(!pg_vec))
3588                 goto out;
3589
3590         for (i = 0; i < block_nr; i++) {
3591                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3592                 if (unlikely(!pg_vec[i].buffer))
3593                         goto out_free_pgvec;
3594         }
3595
3596 out:
3597         return pg_vec;
3598
3599 out_free_pgvec:
3600         free_pg_vec(pg_vec, order, block_nr);
3601         pg_vec = NULL;
3602         goto out;
3603 }
3604
3605 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3606                 int closing, int tx_ring)
3607 {
3608         struct pgv *pg_vec = NULL;
3609         struct packet_sock *po = pkt_sk(sk);
3610         int was_running, order = 0;
3611         struct packet_ring_buffer *rb;
3612         struct sk_buff_head *rb_queue;
3613         __be16 num;
3614         int err = -EINVAL;
3615         /* Added to avoid minimal code churn */
3616         struct tpacket_req *req = &req_u->req;
3617
3618         /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3619         if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3620                 WARN(1, "Tx-ring is not supported.\n");
3621                 goto out;
3622         }
3623
3624         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3625         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3626
3627         err = -EBUSY;
3628         if (!closing) {
3629                 if (atomic_read(&po->mapped))
3630                         goto out;
3631                 if (atomic_read(&rb->pending))
3632                         goto out;
3633         }
3634
3635         if (req->tp_block_nr) {
3636                 /* Sanity tests and some calculations */
3637                 err = -EBUSY;
3638                 if (unlikely(rb->pg_vec))
3639                         goto out;
3640
3641                 switch (po->tp_version) {
3642                 case TPACKET_V1:
3643                         po->tp_hdrlen = TPACKET_HDRLEN;
3644                         break;
3645                 case TPACKET_V2:
3646                         po->tp_hdrlen = TPACKET2_HDRLEN;
3647                         break;
3648                 case TPACKET_V3:
3649                         po->tp_hdrlen = TPACKET3_HDRLEN;
3650                         break;
3651                 }
3652
3653                 err = -EINVAL;
3654                 if (unlikely((int)req->tp_block_size <= 0))
3655                         goto out;
3656                 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3657                         goto out;
3658                 if (po->tp_version >= TPACKET_V3 &&
3659                     (int)(req->tp_block_size -
3660                           BLK_PLUS_PRIV(req_u->req3.tp_sizeof_priv)) <= 0)
3661                         goto out;
3662                 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3663                                         po->tp_reserve))
3664                         goto out;
3665                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3666                         goto out;
3667
3668                 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3669                 if (unlikely(rb->frames_per_block <= 0))
3670                         goto out;
3671                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3672                                         req->tp_frame_nr))
3673                         goto out;
3674
3675                 err = -ENOMEM;
3676                 order = get_order(req->tp_block_size);
3677                 pg_vec = alloc_pg_vec(req, order);
3678                 if (unlikely(!pg_vec))
3679                         goto out;
3680                 switch (po->tp_version) {
3681                 case TPACKET_V3:
3682                 /* Transmit path is not supported. We checked
3683                  * it above but just being paranoid
3684                  */
3685                         if (!tx_ring)
3686                                 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3687                                 break;
3688                 default:
3689                         break;
3690                 }
3691         }
3692         /* Done */
3693         else {
3694                 err = -EINVAL;
3695                 if (unlikely(req->tp_frame_nr))
3696                         goto out;
3697         }
3698
3699         lock_sock(sk);
3700
3701         /* Detach socket from network */
3702         spin_lock(&po->bind_lock);
3703         was_running = po->running;
3704         num = po->num;
3705         if (was_running) {
3706                 po->num = 0;
3707                 __unregister_prot_hook(sk, false);
3708         }
3709         spin_unlock(&po->bind_lock);
3710
3711         synchronize_net();
3712
3713         err = -EBUSY;
3714         mutex_lock(&po->pg_vec_lock);
3715         if (closing || atomic_read(&po->mapped) == 0) {
3716                 err = 0;
3717                 spin_lock_bh(&rb_queue->lock);
3718                 swap(rb->pg_vec, pg_vec);
3719                 rb->frame_max = (req->tp_frame_nr - 1);
3720                 rb->head = 0;
3721                 rb->frame_size = req->tp_frame_size;
3722                 spin_unlock_bh(&rb_queue->lock);
3723
3724                 swap(rb->pg_vec_order, order);
3725                 swap(rb->pg_vec_len, req->tp_block_nr);
3726
3727                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3728                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3729                                                 tpacket_rcv : packet_rcv;
3730                 skb_queue_purge(rb_queue);
3731                 if (atomic_read(&po->mapped))
3732                         pr_err("packet_mmap: vma is busy: %d\n",
3733                                atomic_read(&po->mapped));
3734         }
3735         mutex_unlock(&po->pg_vec_lock);
3736
3737         spin_lock(&po->bind_lock);
3738         if (was_running) {
3739                 po->num = num;
3740                 register_prot_hook(sk);
3741         }
3742         spin_unlock(&po->bind_lock);
3743         if (closing && (po->tp_version > TPACKET_V2)) {
3744                 /* Because we don't support block-based V3 on tx-ring */
3745                 if (!tx_ring)
3746                         prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3747         }
3748         release_sock(sk);
3749
3750         if (pg_vec)
3751                 free_pg_vec(pg_vec, order, req->tp_block_nr);
3752 out:
3753         return err;
3754 }
3755
3756 static int packet_mmap(struct file *file, struct socket *sock,
3757                 struct vm_area_struct *vma)
3758 {
3759         struct sock *sk = sock->sk;
3760         struct packet_sock *po = pkt_sk(sk);
3761         unsigned long size, expected_size;
3762         struct packet_ring_buffer *rb;
3763         unsigned long start;
3764         int err = -EINVAL;
3765         int i;
3766
3767         if (vma->vm_pgoff)
3768                 return -EINVAL;
3769
3770         mutex_lock(&po->pg_vec_lock);
3771
3772         expected_size = 0;
3773         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3774                 if (rb->pg_vec) {
3775                         expected_size += rb->pg_vec_len
3776                                                 * rb->pg_vec_pages
3777                                                 * PAGE_SIZE;
3778                 }
3779         }
3780
3781         if (expected_size == 0)
3782                 goto out;
3783
3784         size = vma->vm_end - vma->vm_start;
3785         if (size != expected_size)
3786                 goto out;
3787
3788         start = vma->vm_start;
3789         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3790                 if (rb->pg_vec == NULL)
3791                         continue;
3792
3793                 for (i = 0; i < rb->pg_vec_len; i++) {
3794                         struct page *page;
3795                         void *kaddr = rb->pg_vec[i].buffer;
3796                         int pg_num;
3797
3798                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3799                                 page = pgv_to_page(kaddr);
3800                                 err = vm_insert_page(vma, start, page);
3801                                 if (unlikely(err))
3802                                         goto out;
3803                                 start += PAGE_SIZE;
3804                                 kaddr += PAGE_SIZE;
3805                         }
3806                 }
3807         }
3808
3809         atomic_inc(&po->mapped);
3810         vma->vm_ops = &packet_mmap_ops;
3811         err = 0;
3812
3813 out:
3814         mutex_unlock(&po->pg_vec_lock);
3815         return err;
3816 }
3817
3818 static const struct proto_ops packet_ops_spkt = {
3819         .family =       PF_PACKET,
3820         .owner =        THIS_MODULE,
3821         .release =      packet_release,
3822         .bind =         packet_bind_spkt,
3823         .connect =      sock_no_connect,
3824         .socketpair =   sock_no_socketpair,
3825         .accept =       sock_no_accept,
3826         .getname =      packet_getname_spkt,
3827         .poll =         datagram_poll,
3828         .ioctl =        packet_ioctl,
3829         .listen =       sock_no_listen,
3830         .shutdown =     sock_no_shutdown,
3831         .setsockopt =   sock_no_setsockopt,
3832         .getsockopt =   sock_no_getsockopt,
3833         .sendmsg =      packet_sendmsg_spkt,
3834         .recvmsg =      packet_recvmsg,
3835         .mmap =         sock_no_mmap,
3836         .sendpage =     sock_no_sendpage,
3837 };
3838
3839 static const struct proto_ops packet_ops = {
3840         .family =       PF_PACKET,
3841         .owner =        THIS_MODULE,
3842         .release =      packet_release,
3843         .bind =         packet_bind,
3844         .connect =      sock_no_connect,
3845         .socketpair =   sock_no_socketpair,
3846         .accept =       sock_no_accept,
3847         .getname =      packet_getname,
3848         .poll =         packet_poll,
3849         .ioctl =        packet_ioctl,
3850         .listen =       sock_no_listen,
3851         .shutdown =     sock_no_shutdown,
3852         .setsockopt =   packet_setsockopt,
3853         .getsockopt =   packet_getsockopt,
3854         .sendmsg =      packet_sendmsg,
3855         .recvmsg =      packet_recvmsg,
3856         .mmap =         packet_mmap,
3857         .sendpage =     sock_no_sendpage,
3858 };
3859
3860 static const struct net_proto_family packet_family_ops = {
3861         .family =       PF_PACKET,
3862         .create =       packet_create,
3863         .owner  =       THIS_MODULE,
3864 };
3865
3866 static struct notifier_block packet_netdev_notifier = {
3867         .notifier_call =        packet_notifier,
3868 };
3869
3870 #ifdef CONFIG_PROC_FS
3871
3872 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3873         __acquires(RCU)
3874 {
3875         struct net *net = seq_file_net(seq);
3876
3877         rcu_read_lock();
3878         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3879 }
3880
3881 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3882 {
3883         struct net *net = seq_file_net(seq);
3884         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3885 }
3886
3887 static void packet_seq_stop(struct seq_file *seq, void *v)
3888         __releases(RCU)
3889 {
3890         rcu_read_unlock();
3891 }
3892
3893 static int packet_seq_show(struct seq_file *seq, void *v)
3894 {
3895         if (v == SEQ_START_TOKEN)
3896                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
3897         else {
3898                 struct sock *s = sk_entry(v);
3899                 const struct packet_sock *po = pkt_sk(s);
3900
3901                 seq_printf(seq,
3902                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
3903                            s,
3904                            atomic_read(&s->sk_refcnt),
3905                            s->sk_type,
3906                            ntohs(po->num),
3907                            po->ifindex,
3908                            po->running,
3909                            atomic_read(&s->sk_rmem_alloc),
3910                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
3911                            sock_i_ino(s));
3912         }
3913
3914         return 0;
3915 }
3916
3917 static const struct seq_operations packet_seq_ops = {
3918         .start  = packet_seq_start,
3919         .next   = packet_seq_next,
3920         .stop   = packet_seq_stop,
3921         .show   = packet_seq_show,
3922 };
3923
3924 static int packet_seq_open(struct inode *inode, struct file *file)
3925 {
3926         return seq_open_net(inode, file, &packet_seq_ops,
3927                             sizeof(struct seq_net_private));
3928 }
3929
3930 static const struct file_operations packet_seq_fops = {
3931         .owner          = THIS_MODULE,
3932         .open           = packet_seq_open,
3933         .read           = seq_read,
3934         .llseek         = seq_lseek,
3935         .release        = seq_release_net,
3936 };
3937
3938 #endif
3939
3940 static int __net_init packet_net_init(struct net *net)
3941 {
3942         mutex_init(&net->packet.sklist_lock);
3943         INIT_HLIST_HEAD(&net->packet.sklist);
3944
3945         if (!proc_create("packet", 0, net->proc_net, &packet_seq_fops))
3946                 return -ENOMEM;
3947
3948         return 0;
3949 }
3950
3951 static void __net_exit packet_net_exit(struct net *net)
3952 {
3953         remove_proc_entry("packet", net->proc_net);
3954 }
3955
3956 static struct pernet_operations packet_net_ops = {
3957         .init = packet_net_init,
3958         .exit = packet_net_exit,
3959 };
3960
3961
3962 static void __exit packet_exit(void)
3963 {
3964         unregister_netdevice_notifier(&packet_netdev_notifier);
3965         unregister_pernet_subsys(&packet_net_ops);
3966         sock_unregister(PF_PACKET);
3967         proto_unregister(&packet_proto);
3968 }
3969
3970 static int __init packet_init(void)
3971 {
3972         int rc = proto_register(&packet_proto, 0);
3973
3974         if (rc != 0)
3975                 goto out;
3976
3977         sock_register(&packet_family_ops);
3978         register_pernet_subsys(&packet_net_ops);
3979         register_netdevice_notifier(&packet_netdev_notifier);
3980 out:
3981         return rc;
3982 }
3983
3984 module_init(packet_init);
3985 module_exit(packet_exit);
3986 MODULE_LICENSE("GPL");
3987 MODULE_ALIAS_NETPROTO(PF_PACKET);