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 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 162                 int closing, int tx_ring);
 163
 164
 165 #define V3_ALIGNMENT    (8)
 166
 167 #define BLK_HDR_LEN     (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
 168
 169 #define BLK_PLUS_PRIV(sz_of_priv) \
 170         (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
 171
 172 #define PGV_FROM_VMALLOC 1
 173
 174 #define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
 175 #define BLOCK_NUM_PKTS(x)       ((x)->hdr.bh1.num_pkts)
 176 #define BLOCK_O2FP(x)           ((x)->hdr.bh1.offset_to_first_pkt)
 177 #define BLOCK_LEN(x)            ((x)->hdr.bh1.blk_len)
 178 #define BLOCK_SNUM(x)           ((x)->hdr.bh1.seq_num)
 179 #define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
 180 #define BLOCK_PRIV(x)           ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
 181
 182 struct packet_sock;
 183 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
 184
 185 static void *packet_previous_frame(struct packet_sock *po,
 186                 struct packet_ring_buffer *rb,
 187                 int status);
 188 static void packet_increment_head(struct packet_ring_buffer *buff);
 189 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
 190                         struct tpacket_block_desc *);
 191 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
 192                         struct packet_sock *);
 193 static void prb_retire_current_block(struct tpacket_kbdq_core *,
 194                 struct packet_sock *, unsigned int status);
 195 static int prb_queue_frozen(struct tpacket_kbdq_core *);
 196 static void prb_open_block(struct tpacket_kbdq_core *,
 197                 struct tpacket_block_desc *);
 198 static void prb_retire_rx_blk_timer_expired(unsigned long);
 199 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
 200 static void prb_init_blk_timer(struct packet_sock *,
 201                 struct tpacket_kbdq_core *,
 202                 void (*func) (unsigned long));
 203 static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
 204 static void prb_clear_rxhash(struct tpacket_kbdq_core *,
 205                 struct tpacket3_hdr *);
 206 static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
 207                 struct tpacket3_hdr *);
 208 static void packet_flush_mclist(struct sock *sk);
 209
 210 struct packet_skb_cb {
 211         unsigned int origlen;
 212         union {
 213                 struct sockaddr_pkt pkt;
 214                 struct sockaddr_ll ll;
 215         } sa;
 216 };
 217
 218 #define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
 219
 220 #define GET_PBDQC_FROM_RB(x)    ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
 221 #define GET_PBLOCK_DESC(x, bid) \
 222         ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
 223 #define GET_CURR_PBLOCK_DESC_FROM_CORE(x)       \
 224         ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
 225 #define GET_NEXT_PRB_BLK_NUM(x) \
 226         (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
 227         ((x)->kactive_blk_num+1) : 0)
 228
 229 static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
 230 static void __fanout_link(struct sock *sk, struct packet_sock *po);
 231
 232 /* register_prot_hook must be invoked with the po->bind_lock held,
 233  * or from a context in which asynchronous accesses to the packet
 234  * socket is not possible (packet_create()).
 235  */
 236 static void register_prot_hook(struct sock *sk)
 237 {
 238         struct packet_sock *po = pkt_sk(sk);
 239         if (!po->running) {
 240                 if (po->fanout)
 241                         __fanout_link(sk, po);
 242                 else
 243                         dev_add_pack(&po->prot_hook);
 244                 sock_hold(sk);
 245                 po->running = 1;
 246         }
 247 }
 248
 249 /* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
 250  * held.   If the sync parameter is true, we will temporarily drop
 251  * the po->bind_lock and do a synchronize_net to make sure no
 252  * asynchronous packet processing paths still refer to the elements
 253  * of po->prot_hook.  If the sync parameter is false, it is the
 254  * callers responsibility to take care of this.
 255  */
 256 static void __unregister_prot_hook(struct sock *sk, bool sync)
 257 {
 258         struct packet_sock *po = pkt_sk(sk);
 259
 260         po->running = 0;
 261         if (po->fanout)
 262                 __fanout_unlink(sk, po);
 263         else
 264                 __dev_remove_pack(&po->prot_hook);
 265         __sock_put(sk);
 266
 267         if (sync) {
 268                 spin_unlock(&po->bind_lock);
 269                 synchronize_net();
 270                 spin_lock(&po->bind_lock);
 271         }
 272 }
 273
 274 static void unregister_prot_hook(struct sock *sk, bool sync)
 275 {
 276         struct packet_sock *po = pkt_sk(sk);
 277
 278         if (po->running)
 279                 __unregister_prot_hook(sk, sync);
 280 }
 281
 282 static inline __pure struct page *pgv_to_page(void *addr)
 283 {
 284         if (is_vmalloc_addr(addr))
 285                 return vmalloc_to_page(addr);
 286         return virt_to_page(addr);
 287 }
 288
 289 static void __packet_set_status(struct packet_sock *po, void *frame, int status)
 290 {
 291         union {
 292                 struct tpacket_hdr *h1;
 293                 struct tpacket2_hdr *h2;
 294                 void *raw;
 295         } h;
 296
 297         h.raw = frame;
 298         switch (po->tp_version) {
 299         case TPACKET_V1:
 300                 h.h1->tp_status = status;
 301                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 302                 break;
 303         case TPACKET_V2:
 304                 h.h2->tp_status = status;
 305                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 306                 break;
 307         case TPACKET_V3:
 308         default:
 309                 WARN(1, "TPACKET version not supported.\n");
 310                 BUG();
 311         }
 312
 313         smp_wmb();
 314 }
 315
 316 static int __packet_get_status(struct packet_sock *po, void *frame)
 317 {
 318         union {
 319                 struct tpacket_hdr *h1;
 320                 struct tpacket2_hdr *h2;
 321                 void *raw;
 322         } h;
 323
 324         smp_rmb();
 325
 326         h.raw = frame;
 327         switch (po->tp_version) {
 328         case TPACKET_V1:
 329                 flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 330                 return h.h1->tp_status;
 331         case TPACKET_V2:
 332                 flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 333                 return h.h2->tp_status;
 334         case TPACKET_V3:
 335         default:
 336                 WARN(1, "TPACKET version not supported.\n");
 337                 BUG();
 338                 return 0;
 339         }
 340 }
 341
 342 static void *packet_lookup_frame(struct packet_sock *po,
 343                 struct packet_ring_buffer *rb,
 344                 unsigned int position,
 345                 int status)
 346 {
 347         unsigned int pg_vec_pos, frame_offset;
 348         union {
 349                 struct tpacket_hdr *h1;
 350                 struct tpacket2_hdr *h2;
 351                 void *raw;
 352         } h;
 353
 354         pg_vec_pos = position / rb->frames_per_block;
 355         frame_offset = position % rb->frames_per_block;
 356
 357         h.raw = rb->pg_vec[pg_vec_pos].buffer +
 358                 (frame_offset * rb->frame_size);
 359
 360         if (status != __packet_get_status(po, h.raw))
 361                 return NULL;
 362
 363         return h.raw;
 364 }
 365
 366 static void *packet_current_frame(struct packet_sock *po,
 367                 struct packet_ring_buffer *rb,
 368                 int status)
 369 {
 370         return packet_lookup_frame(po, rb, rb->head, status);
 371 }
 372
 373 static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 374 {
 375         del_timer_sync(&pkc->retire_blk_timer);
 376 }
 377
 378 static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
 379                 int tx_ring,
 380                 struct sk_buff_head *rb_queue)
 381 {
 382         struct tpacket_kbdq_core *pkc;
 383
 384         pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
 385
 386         spin_lock(&rb_queue->lock);
 387         pkc->delete_blk_timer = 1;
 388         spin_unlock(&rb_queue->lock);
 389
 390         prb_del_retire_blk_timer(pkc);
 391 }
 392
 393 static void prb_init_blk_timer(struct packet_sock *po,
 394                 struct tpacket_kbdq_core *pkc,
 395                 void (*func) (unsigned long))
 396 {
 397         init_timer(&pkc->retire_blk_timer);
 398         pkc->retire_blk_timer.data = (long)po;
 399         pkc->retire_blk_timer.function = func;
 400         pkc->retire_blk_timer.expires = jiffies;
 401 }
 402
 403 static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
 404 {
 405         struct tpacket_kbdq_core *pkc;
 406
 407         if (tx_ring)
 408                 BUG();
 409
 410         pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
 411         prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
 412 }
 413
 414 static int prb_calc_retire_blk_tmo(struct packet_sock *po,
 415                                 int blk_size_in_bytes)
 416 {
 417         struct net_device *dev;
 418         unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
 419         struct ethtool_cmd ecmd;
 420         int err;
 421         u32 speed;
 422
 423         rtnl_lock();
 424         dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
 425         if (unlikely(!dev)) {
 426                 rtnl_unlock();
 427                 return DEFAULT_PRB_RETIRE_TOV;
 428         }
 429         err = __ethtool_get_settings(dev, &ecmd);
 430         speed = ethtool_cmd_speed(&ecmd);
 431         rtnl_unlock();
 432         if (!err) {
 433                 /*
 434                  * If the link speed is so slow you don't really
 435                  * need to worry about perf anyways
 436                  */
 437                 if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
 438                         return DEFAULT_PRB_RETIRE_TOV;
 439                 } else {
 440                         msec = 1;
 441                         div = speed / 1000;
 442                 }
 443         }
 444
 445         mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
 446
 447         if (div)
 448                 mbits /= div;
 449
 450         tmo = mbits * msec;
 451
 452         if (div)
 453                 return tmo+1;
 454         return tmo;
 455 }
 456
 457 static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
 458                         union tpacket_req_u *req_u)
 459 {
 460         p1->feature_req_word = req_u->req3.tp_feature_req_word;
 461 }
 462
 463 static void init_prb_bdqc(struct packet_sock *po,
 464                         struct packet_ring_buffer *rb,
 465                         struct pgv *pg_vec,
 466                         union tpacket_req_u *req_u, int tx_ring)
 467 {
 468         struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
 469         struct tpacket_block_desc *pbd;
 470
 471         memset(p1, 0x0, sizeof(*p1));
 472
 473         p1->knxt_seq_num = 1;
 474         p1->pkbdq = pg_vec;
 475         pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
 476         p1->pkblk_start = pg_vec[0].buffer;
 477         p1->kblk_size = req_u->req3.tp_block_size;
 478         p1->knum_blocks = req_u->req3.tp_block_nr;
 479         p1->hdrlen = po->tp_hdrlen;
 480         p1->version = po->tp_version;
 481         p1->last_kactive_blk_num = 0;
 482         po->stats_u.stats3.tp_freeze_q_cnt = 0;
 483         if (req_u->req3.tp_retire_blk_tov)
 484                 p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
 485         else
 486                 p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
 487                                                 req_u->req3.tp_block_size);
 488         p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
 489         p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
 490
 491         prb_init_ft_ops(p1, req_u);
 492         prb_setup_retire_blk_timer(po, tx_ring);
 493         prb_open_block(p1, pbd);
 494 }
 495
 496 /*  Do NOT update the last_blk_num first.
 497  *  Assumes sk_buff_head lock is held.
 498  */
 499 static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 500 {
 501         mod_timer(&pkc->retire_blk_timer,
 502                         jiffies + pkc->tov_in_jiffies);
 503         pkc->last_kactive_blk_num = pkc->kactive_blk_num;
 504 }
 505
 506 /*
 507  * Timer logic:
 508  * 1) We refresh the timer only when we open a block.
 509  *    By doing this we don't waste cycles refreshing the timer
 510  *        on packet-by-packet basis.
 511  *
 512  * With a 1MB block-size, on a 1Gbps line, it will take
 513  * i) ~8 ms to fill a block + ii) memcpy etc.
 514  * In this cut we are not accounting for the memcpy time.
 515  *
 516  * So, if the user sets the 'tmo' to 10ms then the timer
 517  * will never fire while the block is still getting filled
 518  * (which is what we want). However, the user could choose
 519  * to close a block early and that's fine.
 520  *
 521  * But when the timer does fire, we check whether or not to refresh it.
 522  * Since the tmo granularity is in msecs, it is not too expensive
 523  * to refresh the timer, lets say every '8' msecs.
 524  * Either the user can set the 'tmo' or we can derive it based on
 525  * a) line-speed and b) block-size.
 526  * prb_calc_retire_blk_tmo() calculates the tmo.
 527  *
 528  */
 529 static void prb_retire_rx_blk_timer_expired(unsigned long data)
 530 {
 531         struct packet_sock *po = (struct packet_sock *)data;
 532         struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
 533         unsigned int frozen;
 534         struct tpacket_block_desc *pbd;
 535
 536         spin_lock(&po->sk.sk_receive_queue.lock);
 537
 538         frozen = prb_queue_frozen(pkc);
 539         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 540
 541         if (unlikely(pkc->delete_blk_timer))
 542                 goto out;
 543
 544         /* We only need to plug the race when the block is partially filled.
 545          * tpacket_rcv:
 546          *              lock(); increment BLOCK_NUM_PKTS; unlock()
 547          *              copy_bits() is in progress ...
 548          *              timer fires on other cpu:
 549          *              we can't retire the current block because copy_bits
 550          *              is in progress.
 551          *
 552          */
 553         if (BLOCK_NUM_PKTS(pbd)) {
 554                 while (atomic_read(&pkc->blk_fill_in_prog)) {
 555                         /* Waiting for skb_copy_bits to finish... */
 556                         cpu_relax();
 557                 }
 558         }
 559
 560         if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
 561                 if (!frozen) {
 562                         prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
 563                         if (!prb_dispatch_next_block(pkc, po))
 564                                 goto refresh_timer;
 565                         else
 566                                 goto out;
 567                 } else {
 568                         /* Case 1. Queue was frozen because user-space was
 569                          *         lagging behind.
 570                          */
 571                         if (prb_curr_blk_in_use(pkc, pbd)) {
 572                                 /*
 573                                  * Ok, user-space is still behind.
 574                                  * So just refresh the timer.
 575                                  */
 576                                 goto refresh_timer;
 577                         } else {
 578                                /* Case 2. queue was frozen,user-space caught up,
 579                                 * now the link went idle && the timer fired.
 580                                 * We don't have a block to close.So we open this
 581                                 * block and restart the timer.
 582                                 * opening a block thaws the queue,restarts timer
 583                                 * Thawing/timer-refresh is a side effect.
 584                                 */
 585                                 prb_open_block(pkc, pbd);
 586                                 goto out;
 587                         }
 588                 }
 589         }
 590
 591 refresh_timer:
 592         _prb_refresh_rx_retire_blk_timer(pkc);
 593
 594 out:
 595         spin_unlock(&po->sk.sk_receive_queue.lock);
 596 }
 597
 598 static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
 599                 struct tpacket_block_desc *pbd1, __u32 status)
 600 {
 601         /* Flush everything minus the block header */
 602
 603 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 604         u8 *start, *end;
 605
 606         start = (u8 *)pbd1;
 607
 608         /* Skip the block header(we know header WILL fit in 4K) */
 609         start += PAGE_SIZE;
 610
 611         end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
 612         for (; start < end; start += PAGE_SIZE)
 613                 flush_dcache_page(pgv_to_page(start));
 614
 615         smp_wmb();
 616 #endif
 617
 618         /* Now update the block status. */
 619
 620         BLOCK_STATUS(pbd1) = status;
 621
 622         /* Flush the block header */
 623
 624 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 625         start = (u8 *)pbd1;
 626         flush_dcache_page(pgv_to_page(start));
 627
 628         smp_wmb();
 629 #endif
 630 }
 631
 632 /*
 633  * Side effect:
 634  *
 635  * 1) flush the block
 636  * 2) Increment active_blk_num
 637  *
 638  * Note:We DONT refresh the timer on purpose.
 639  *      Because almost always the next block will be opened.
 640  */
 641 static void prb_close_block(struct tpacket_kbdq_core *pkc1,
 642                 struct tpacket_block_desc *pbd1,
 643                 struct packet_sock *po, unsigned int stat)
 644 {
 645         __u32 status = TP_STATUS_USER | stat;
 646
 647         struct tpacket3_hdr *last_pkt;
 648         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 649
 650         if (po->stats.tp_drops)
 651                 status |= TP_STATUS_LOSING;
 652
 653         last_pkt = (struct tpacket3_hdr *)pkc1->prev;
 654         last_pkt->tp_next_offset = 0;
 655
 656         /* Get the ts of the last pkt */
 657         if (BLOCK_NUM_PKTS(pbd1)) {
 658                 h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
 659                 h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
 660         } else {
 661                 /* Ok, we tmo'd - so get the current time */
 662                 struct timespec ts;
 663                 getnstimeofday(&ts);
 664                 h1->ts_last_pkt.ts_sec = ts.tv_sec;
 665                 h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
 666         }
 667
 668         smp_wmb();
 669
 670         /* Flush the block */
 671         prb_flush_block(pkc1, pbd1, status);
 672
 673         pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
 674 }
 675
 676 static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
 677 {
 678         pkc->reset_pending_on_curr_blk = 0;
 679 }
 680
 681 /*
 682  * Side effect of opening a block:
 683  *
 684  * 1) prb_queue is thawed.
 685  * 2) retire_blk_timer is refreshed.
 686  *
 687  */
 688 static void prb_open_block(struct tpacket_kbdq_core *pkc1,
 689         struct tpacket_block_desc *pbd1)
 690 {
 691         struct timespec ts;
 692         struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 693
 694         smp_rmb();
 695
 696         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) {
 697
 698                 /* We could have just memset this but we will lose the
 699                  * flexibility of making the priv area sticky
 700                  */
 701                 BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
 702                 BLOCK_NUM_PKTS(pbd1) = 0;
 703                 BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 704                 getnstimeofday(&ts);
 705                 h1->ts_first_pkt.ts_sec = ts.tv_sec;
 706                 h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
 707                 pkc1->pkblk_start = (char *)pbd1;
 708                 pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 709                 BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 710                 BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
 711                 pbd1->version = pkc1->version;
 712                 pkc1->prev = pkc1->nxt_offset;
 713                 pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
 714                 prb_thaw_queue(pkc1);
 715                 _prb_refresh_rx_retire_blk_timer(pkc1);
 716
 717                 smp_wmb();
 718
 719                 return;
 720         }
 721
 722         WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n",
 723                 pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num);
 724         dump_stack();
 725         BUG();
 726 }
 727
 728 /*
 729  * Queue freeze logic:
 730  * 1) Assume tp_block_nr = 8 blocks.
 731  * 2) At time 't0', user opens Rx ring.
 732  * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
 733  * 4) user-space is either sleeping or processing block '0'.
 734  * 5) tpacket_rcv is currently filling block '7', since there is no space left,
 735  *    it will close block-7,loop around and try to fill block '0'.
 736  *    call-flow:
 737  *    __packet_lookup_frame_in_block
 738  *      prb_retire_current_block()
 739  *      prb_dispatch_next_block()
 740  *        |->(BLOCK_STATUS == USER) evaluates to true
 741  *    5.1) Since block-0 is currently in-use, we just freeze the queue.
 742  * 6) Now there are two cases:
 743  *    6.1) Link goes idle right after the queue is frozen.
 744  *         But remember, the last open_block() refreshed the timer.
 745  *         When this timer expires,it will refresh itself so that we can
 746  *         re-open block-0 in near future.
 747  *    6.2) Link is busy and keeps on receiving packets. This is a simple
 748  *         case and __packet_lookup_frame_in_block will check if block-0
 749  *         is free and can now be re-used.
 750  */
 751 static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
 752                                   struct packet_sock *po)
 753 {
 754         pkc->reset_pending_on_curr_blk = 1;
 755         po->stats_u.stats3.tp_freeze_q_cnt++;
 756 }
 757
 758 #define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
 759
 760 /*
 761  * If the next block is free then we will dispatch it
 762  * and return a good offset.
 763  * Else, we will freeze the queue.
 764  * So, caller must check the return value.
 765  */
 766 static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
 767                 struct packet_sock *po)
 768 {
 769         struct tpacket_block_desc *pbd;
 770
 771         smp_rmb();
 772
 773         /* 1. Get current block num */
 774         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 775
 776         /* 2. If this block is currently in_use then freeze the queue */
 777         if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
 778                 prb_freeze_queue(pkc, po);
 779                 return NULL;
 780         }
 781
 782         /*
 783          * 3.
 784          * open this block and return the offset where the first packet
 785          * needs to get stored.
 786          */
 787         prb_open_block(pkc, pbd);
 788         return (void *)pkc->nxt_offset;
 789 }
 790
 791 static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
 792                 struct packet_sock *po, unsigned int status)
 793 {
 794         struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 795
 796         /* retire/close the current block */
 797         if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
 798                 /*
 799                  * Plug the case where copy_bits() is in progress on
 800                  * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
 801                  * have space to copy the pkt in the current block and
 802                  * called prb_retire_current_block()
 803                  *
 804                  * We don't need to worry about the TMO case because
 805                  * the timer-handler already handled this case.
 806                  */
 807                 if (!(status & TP_STATUS_BLK_TMO)) {
 808                         while (atomic_read(&pkc->blk_fill_in_prog)) {
 809                                 /* Waiting for skb_copy_bits to finish... */
 810                                 cpu_relax();
 811                         }
 812                 }
 813                 prb_close_block(pkc, pbd, po, status);
 814                 return;
 815         }
 816
 817         WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd);
 818         dump_stack();
 819         BUG();
 820 }
 821
 822 static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
 823                                       struct tpacket_block_desc *pbd)
 824 {
 825         return TP_STATUS_USER & BLOCK_STATUS(pbd);
 826 }
 827
 828 static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
 829 {
 830         return pkc->reset_pending_on_curr_blk;
 831 }
 832
 833 static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
 834 {
 835         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
 836         atomic_dec(&pkc->blk_fill_in_prog);
 837 }
 838
 839 static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
 840                         struct tpacket3_hdr *ppd)
 841 {
 842         ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
 843 }
 844
 845 static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
 846                         struct tpacket3_hdr *ppd)
 847 {
 848         ppd->hv1.tp_rxhash = 0;
 849 }
 850
 851 static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
 852                         struct tpacket3_hdr *ppd)
 853 {
 854         if (vlan_tx_tag_present(pkc->skb)) {
 855                 ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
 856                 ppd->tp_status = TP_STATUS_VLAN_VALID;
 857         } else {
 858                 ppd->hv1.tp_vlan_tci = 0;
 859                 ppd->tp_status = TP_STATUS_AVAILABLE;
 860         }
 861 }
 862
 863 static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
 864                         struct tpacket3_hdr *ppd)
 865 {
 866         prb_fill_vlan_info(pkc, ppd);
 867
 868         if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
 869                 prb_fill_rxhash(pkc, ppd);
 870         else
 871                 prb_clear_rxhash(pkc, ppd);
 872 }
 873
 874 static void prb_fill_curr_block(char *curr,
 875                                 struct tpacket_kbdq_core *pkc,
 876                                 struct tpacket_block_desc *pbd,
 877                                 unsigned int len)
 878 {
 879         struct tpacket3_hdr *ppd;
 880
 881         ppd  = (struct tpacket3_hdr *)curr;
 882         ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
 883         pkc->prev = curr;
 884         pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
 885         BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
 886         BLOCK_NUM_PKTS(pbd) += 1;
 887         atomic_inc(&pkc->blk_fill_in_prog);
 888         prb_run_all_ft_ops(pkc, ppd);
 889 }
 890
 891 /* Assumes caller has the sk->rx_queue.lock */
 892 static void *__packet_lookup_frame_in_block(struct packet_sock *po,
 893                                             struct sk_buff *skb,
 894                                                 int status,
 895                                             unsigned int len
 896                                             )
 897 {
 898         struct tpacket_kbdq_core *pkc;
 899         struct tpacket_block_desc *pbd;
 900         char *curr, *end;
 901
 902         pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
 903         pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 904
 905         /* Queue is frozen when user space is lagging behind */
 906         if (prb_queue_frozen(pkc)) {
 907                 /*
 908                  * Check if that last block which caused the queue to freeze,
 909                  * is still in_use by user-space.
 910                  */
 911                 if (prb_curr_blk_in_use(pkc, pbd)) {
 912                         /* Can't record this packet */
 913                         return NULL;
 914                 } else {
 915                         /*
 916                          * Ok, the block was released by user-space.
 917                          * Now let's open that block.
 918                          * opening a block also thaws the queue.
 919                          * Thawing is a side effect.
 920                          */
 921                         prb_open_block(pkc, pbd);
 922                 }
 923         }
 924
 925         smp_mb();
 926         curr = pkc->nxt_offset;
 927         pkc->skb = skb;
 928         end = (char *)pbd + pkc->kblk_size;
 929
 930         /* first try the current block */
 931         if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
 932                 prb_fill_curr_block(curr, pkc, pbd, len);
 933                 return (void *)curr;
 934         }
 935
 936         /* Ok, close the current block */
 937         prb_retire_current_block(pkc, po, 0);
 938
 939         /* Now, try to dispatch the next block */
 940         curr = (char *)prb_dispatch_next_block(pkc, po);
 941         if (curr) {
 942                 pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 943                 prb_fill_curr_block(curr, pkc, pbd, len);
 944                 return (void *)curr;
 945         }
 946
 947         /*
 948          * No free blocks are available.user_space hasn't caught up yet.
 949          * Queue was just frozen and now this packet will get dropped.
 950          */
 951         return NULL;
 952 }
 953
 954 static void *packet_current_rx_frame(struct packet_sock *po,
 955                                             struct sk_buff *skb,
 956                                             int status, unsigned int len)
 957 {
 958         char *curr = NULL;
 959         switch (po->tp_version) {
 960         case TPACKET_V1:
 961         case TPACKET_V2:
 962                 curr = packet_lookup_frame(po, &po->rx_ring,
 963                                         po->rx_ring.head, status);
 964                 return curr;
 965         case TPACKET_V3:
 966                 return __packet_lookup_frame_in_block(po, skb, status, len);
 967         default:
 968                 WARN(1, "TPACKET version not supported\n");
 969                 BUG();
 970                 return NULL;
 971         }
 972 }
 973
 974 static void *prb_lookup_block(struct packet_sock *po,
 975                                      struct packet_ring_buffer *rb,
 976                                      unsigned int previous,
 977                                      int status)
 978 {
 979         struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
 980         struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous);
 981
 982         if (status != BLOCK_STATUS(pbd))
 983                 return NULL;
 984         return pbd;
 985 }
 986
 987 static int prb_previous_blk_num(struct packet_ring_buffer *rb)
 988 {
 989         unsigned int prev;
 990         if (rb->prb_bdqc.kactive_blk_num)
 991                 prev = rb->prb_bdqc.kactive_blk_num-1;
 992         else
 993                 prev = rb->prb_bdqc.knum_blocks-1;
 994         return prev;
 995 }
 996
 997 /* Assumes caller has held the rx_queue.lock */
 998 static void *__prb_previous_block(struct packet_sock *po,
 999                                          struct packet_ring_buffer *rb,
1000                                          int status)
1001 {
1002         unsigned int previous = prb_previous_blk_num(rb);
1003         return prb_lookup_block(po, rb, previous, status);
1004 }
1005
1006 static void *packet_previous_rx_frame(struct packet_sock *po,
1007                                              struct packet_ring_buffer *rb,
1008                                              int status)
1009 {
1010         if (po->tp_version <= TPACKET_V2)
1011                 return packet_previous_frame(po, rb, status);
1012
1013         return __prb_previous_block(po, rb, status);
1014 }
1015
1016 static void packet_increment_rx_head(struct packet_sock *po,
1017                                             struct packet_ring_buffer *rb)
1018 {
1019         switch (po->tp_version) {
1020         case TPACKET_V1:
1021         case TPACKET_V2:
1022                 return packet_increment_head(rb);
1023         case TPACKET_V3:
1024         default:
1025                 WARN(1, "TPACKET version not supported.\n");
1026                 BUG();
1027                 return;
1028         }
1029 }
1030
1031 static void *packet_previous_frame(struct packet_sock *po,
1032                 struct packet_ring_buffer *rb,
1033                 int status)
1034 {
1035         unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1036         return packet_lookup_frame(po, rb, previous, status);
1037 }
1038
1039 static void packet_increment_head(struct packet_ring_buffer *buff)
1040 {
1041         buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1042 }
1043
1044 static void packet_sock_destruct(struct sock *sk)
1045 {
1046         skb_queue_purge(&sk->sk_error_queue);
1047
1048         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1049         WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1050
1051         if (!sock_flag(sk, SOCK_DEAD)) {
1052                 pr_err("Attempt to release alive packet socket: %p\n", sk);
1053                 return;
1054         }
1055
1056         sk_refcnt_debug_dec(sk);
1057 }
1058
1059 static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1060 {
1061         int x = atomic_read(&f->rr_cur) + 1;
1062
1063         if (x >= num)
1064                 x = 0;
1065
1066         return x;
1067 }
1068
1069 static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1070 {
1071         u32 idx, hash = skb->rxhash;
1072
1073         idx = ((u64)hash * num) >> 32;
1074
1075         return f->arr[idx];
1076 }
1077
1078 static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1079 {
1080         int cur, old;
1081
1082         cur = atomic_read(&f->rr_cur);
1083         while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1084                                      fanout_rr_next(f, num))) != cur)
1085                 cur = old;
1086         return f->arr[cur];
1087 }
1088
1089 static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1090 {
1091         unsigned int cpu = smp_processor_id();
1092
1093         return f->arr[cpu % num];
1094 }
1095
1096 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1097                              struct packet_type *pt, struct net_device *orig_dev)
1098 {
1099         struct packet_fanout *f = pt->af_packet_priv;
1100         unsigned int num = f->num_members;
1101         struct packet_sock *po;
1102         struct sock *sk;
1103
1104         if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1105             !num) {
1106                 kfree_skb(skb);
1107                 return 0;
1108         }
1109
1110         switch (f->type) {
1111         case PACKET_FANOUT_HASH:
1112         default:
1113                 if (f->defrag) {
1114                         skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1115                         if (!skb)
1116                                 return 0;
1117                 }
1118                 skb_get_rxhash(skb);
1119                 sk = fanout_demux_hash(f, skb, num);
1120                 break;
1121         case PACKET_FANOUT_LB:
1122                 sk = fanout_demux_lb(f, skb, num);
1123                 break;
1124         case PACKET_FANOUT_CPU:
1125                 sk = fanout_demux_cpu(f, skb, num);
1126                 break;
1127         }
1128
1129         po = pkt_sk(sk);
1130
1131         return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1132 }
1133
1134 DEFINE_MUTEX(fanout_mutex);
1135 EXPORT_SYMBOL_GPL(fanout_mutex);
1136 static LIST_HEAD(fanout_list);
1137
1138 static void __fanout_link(struct sock *sk, struct packet_sock *po)
1139 {
1140         struct packet_fanout *f = po->fanout;
1141
1142         spin_lock(&f->lock);
1143         f->arr[f->num_members] = sk;
1144         smp_wmb();
1145         f->num_members++;
1146         spin_unlock(&f->lock);
1147 }
1148
1149 static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1150 {
1151         struct packet_fanout *f = po->fanout;
1152         int i;
1153
1154         spin_lock(&f->lock);
1155         for (i = 0; i < f->num_members; i++) {
1156                 if (f->arr[i] == sk)
1157                         break;
1158         }
1159         BUG_ON(i >= f->num_members);
1160         f->arr[i] = f->arr[f->num_members - 1];
1161         f->num_members--;
1162         spin_unlock(&f->lock);
1163 }
1164
1165 static bool match_fanout_group(struct packet_type *ptype, struct sock * sk)
1166 {
1167         if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout)
1168                 return true;
1169
1170         return false;
1171 }
1172
1173 static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1174 {
1175         struct packet_sock *po = pkt_sk(sk);
1176         struct packet_fanout *f, *match;
1177         u8 type = type_flags & 0xff;
1178         u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0;
1179         int err;
1180
1181         switch (type) {
1182         case PACKET_FANOUT_HASH:
1183         case PACKET_FANOUT_LB:
1184         case PACKET_FANOUT_CPU:
1185                 break;
1186         default:
1187                 return -EINVAL;
1188         }
1189
1190         if (!po->running)
1191                 return -EINVAL;
1192
1193         if (po->fanout)
1194                 return -EALREADY;
1195
1196         mutex_lock(&fanout_mutex);
1197         match = NULL;
1198         list_for_each_entry(f, &fanout_list, list) {
1199                 if (f->id == id &&
1200                     read_pnet(&f->net) == sock_net(sk)) {
1201                         match = f;
1202                         break;
1203                 }
1204         }
1205         err = -EINVAL;
1206         if (match && match->defrag != defrag)
1207                 goto out;
1208         if (!match) {
1209                 err = -ENOMEM;
1210                 match = kzalloc(sizeof(*match), GFP_KERNEL);
1211                 if (!match)
1212                         goto out;
1213                 write_pnet(&match->net, sock_net(sk));
1214                 match->id = id;
1215                 match->type = type;
1216                 match->defrag = defrag;
1217                 atomic_set(&match->rr_cur, 0);
1218                 INIT_LIST_HEAD(&match->list);
1219                 spin_lock_init(&match->lock);
1220                 atomic_set(&match->sk_ref, 0);
1221                 match->prot_hook.type = po->prot_hook.type;
1222                 match->prot_hook.dev = po->prot_hook.dev;
1223                 match->prot_hook.func = packet_rcv_fanout;
1224                 match->prot_hook.af_packet_priv = match;
1225                 match->prot_hook.id_match = match_fanout_group;
1226                 dev_add_pack(&match->prot_hook);
1227                 list_add(&match->list, &fanout_list);
1228         }
1229         err = -EINVAL;
1230         if (match->type == type &&
1231             match->prot_hook.type == po->prot_hook.type &&
1232             match->prot_hook.dev == po->prot_hook.dev) {
1233                 err = -ENOSPC;
1234                 if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1235                         __dev_remove_pack(&po->prot_hook);
1236                         po->fanout = match;
1237                         atomic_inc(&match->sk_ref);
1238                         __fanout_link(sk, po);
1239                         err = 0;
1240                 }
1241         }
1242 out:
1243         mutex_unlock(&fanout_mutex);
1244         return err;
1245 }
1246
1247 static void fanout_release(struct sock *sk)
1248 {
1249         struct packet_sock *po = pkt_sk(sk);
1250         struct packet_fanout *f;
1251
1252         f = po->fanout;
1253         if (!f)
1254                 return;
1255
1256         mutex_lock(&fanout_mutex);
1257         po->fanout = NULL;
1258
1259         if (atomic_dec_and_test(&f->sk_ref)) {
1260                 list_del(&f->list);
1261                 dev_remove_pack(&f->prot_hook);
1262                 kfree(f);
1263         }
1264         mutex_unlock(&fanout_mutex);
1265 }
1266
1267 static const struct proto_ops packet_ops;
1268
1269 static const struct proto_ops packet_ops_spkt;
1270
1271 static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1272                            struct packet_type *pt, struct net_device *orig_dev)
1273 {
1274         struct sock *sk;
1275         struct sockaddr_pkt *spkt;
1276
1277         /*
1278          *      When we registered the protocol we saved the socket in the data
1279          *      field for just this event.
1280          */
1281
1282         sk = pt->af_packet_priv;
1283
1284         /*
1285          *      Yank back the headers [hope the device set this
1286          *      right or kerboom...]
1287          *
1288          *      Incoming packets have ll header pulled,
1289          *      push it back.
1290          *
1291          *      For outgoing ones skb->data == skb_mac_header(skb)
1292          *      so that this procedure is noop.
1293          */
1294
1295         if (skb->pkt_type == PACKET_LOOPBACK)
1296                 goto out;
1297
1298         if (!net_eq(dev_net(dev), sock_net(sk)))
1299                 goto out;
1300
1301         skb = skb_share_check(skb, GFP_ATOMIC);
1302         if (skb == NULL)
1303                 goto oom;
1304
1305         /* drop any routing info */
1306         skb_dst_drop(skb);
1307
1308         /* drop conntrack reference */
1309         nf_reset(skb);
1310
1311         spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1312
1313         skb_push(skb, skb->data - skb_mac_header(skb));
1314
1315         /*
1316          *      The SOCK_PACKET socket receives _all_ frames.
1317          */
1318
1319         spkt->spkt_family = dev->type;
1320         strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1321         spkt->spkt_protocol = skb->protocol;
1322
1323         /*
1324          *      Charge the memory to the socket. This is done specifically
1325          *      to prevent sockets using all the memory up.
1326          */
1327
1328         if (sock_queue_rcv_skb(sk, skb) == 0)
1329                 return 0;
1330
1331 out:
1332         kfree_skb(skb);
1333 oom:
1334         return 0;
1335 }
1336
1337
1338 /*
1339  *      Output a raw packet to a device layer. This bypasses all the other
1340  *      protocol layers and you must therefore supply it with a complete frame
1341  */
1342
1343 static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1344                                struct msghdr *msg, size_t len)
1345 {
1346         struct sock *sk = sock->sk;
1347         struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1348         struct sk_buff *skb = NULL;
1349         struct net_device *dev;
1350         __be16 proto = 0;
1351         int err;
1352         int extra_len = 0;
1353
1354         /*
1355          *      Get and verify the address.
1356          */
1357
1358         if (saddr) {
1359                 if (msg->msg_namelen < sizeof(struct sockaddr))
1360                         return -EINVAL;
1361                 if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1362                         proto = saddr->spkt_protocol;
1363         } else
1364                 return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1365
1366         /*
1367          *      Find the device first to size check it
1368          */
1369
1370         saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1371 retry:
1372         rcu_read_lock();
1373         dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1374         err = -ENODEV;
1375         if (dev == NULL)
1376                 goto out_unlock;
1377
1378         err = -ENETDOWN;
1379         if (!(dev->flags & IFF_UP))
1380                 goto out_unlock;
1381
1382         /*
1383          * You may not queue a frame bigger than the mtu. This is the lowest level
1384          * raw protocol and you must do your own fragmentation at this level.
1385          */
1386
1387         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1388                 if (!netif_supports_nofcs(dev)) {
1389                         err = -EPROTONOSUPPORT;
1390                         goto out_unlock;
1391                 }
1392                 extra_len = 4; /* We're doing our own CRC */
1393         }
1394
1395         err = -EMSGSIZE;
1396         if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1397                 goto out_unlock;
1398
1399         if (!skb) {
1400                 size_t reserved = LL_RESERVED_SPACE(dev);
1401                 int tlen = dev->needed_tailroom;
1402                 unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1403
1404                 rcu_read_unlock();
1405                 skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1406                 if (skb == NULL)
1407                         return -ENOBUFS;
1408                 /* FIXME: Save some space for broken drivers that write a hard
1409                  * header at transmission time by themselves. PPP is the notable
1410                  * one here. This should really be fixed at the driver level.
1411                  */
1412                 skb_reserve(skb, reserved);
1413                 skb_reset_network_header(skb);
1414
1415                 /* Try to align data part correctly */
1416                 if (hhlen) {
1417                         skb->data -= hhlen;
1418                         skb->tail -= hhlen;
1419                         if (len < hhlen)
1420                                 skb_reset_network_header(skb);
1421                 }
1422                 err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1423                 if (err)
1424                         goto out_free;
1425                 goto retry;
1426         }
1427
1428         if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1429                 /* Earlier code assumed this would be a VLAN pkt,
1430                  * double-check this now that we have the actual
1431                  * packet in hand.
1432                  */
1433                 struct ethhdr *ehdr;
1434                 skb_reset_mac_header(skb);
1435                 ehdr = eth_hdr(skb);
1436                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1437                         err = -EMSGSIZE;
1438                         goto out_unlock;
1439                 }
1440         }
1441
1442         skb->protocol = proto;
1443         skb->dev = dev;
1444         skb->priority = sk->sk_priority;
1445         skb->mark = sk->sk_mark;
1446         err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1447         if (err < 0)
1448                 goto out_unlock;
1449
1450         if (unlikely(extra_len == 4))
1451                 skb->no_fcs = 1;
1452
1453         dev_queue_xmit(skb);
1454         rcu_read_unlock();
1455         return len;
1456
1457 out_unlock:
1458         rcu_read_unlock();
1459 out_free:
1460         kfree_skb(skb);
1461         return err;
1462 }
1463
1464 static unsigned int run_filter(const struct sk_buff *skb,
1465                                       const struct sock *sk,
1466                                       unsigned int res)
1467 {
1468         struct sk_filter *filter;
1469
1470         rcu_read_lock();
1471         filter = rcu_dereference(sk->sk_filter);
1472         if (filter != NULL)
1473                 res = SK_RUN_FILTER(filter, skb);
1474         rcu_read_unlock();
1475
1476         return res;
1477 }
1478
1479 /*
1480  * This function makes lazy skb cloning in hope that most of packets
1481  * are discarded by BPF.
1482  *
1483  * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1484  * and skb->cb are mangled. It works because (and until) packets
1485  * falling here are owned by current CPU. Output packets are cloned
1486  * by dev_queue_xmit_nit(), input packets are processed by net_bh
1487  * sequencially, so that if we return skb to original state on exit,
1488  * we will not harm anyone.
1489  */
1490
1491 static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1492                       struct packet_type *pt, struct net_device *orig_dev)
1493 {
1494         struct sock *sk;
1495         struct sockaddr_ll *sll;
1496         struct packet_sock *po;
1497         u8 *skb_head = skb->data;
1498         int skb_len = skb->len;
1499         unsigned int snaplen, res;
1500
1501         if (skb->pkt_type == PACKET_LOOPBACK)
1502                 goto drop;
1503
1504         sk = pt->af_packet_priv;
1505         po = pkt_sk(sk);
1506
1507         if (!net_eq(dev_net(dev), sock_net(sk)))
1508                 goto drop;
1509
1510         skb->dev = dev;
1511
1512         if (dev->header_ops) {
1513                 /* The device has an explicit notion of ll header,
1514                  * exported to higher levels.
1515                  *
1516                  * Otherwise, the device hides details of its frame
1517                  * structure, so that corresponding packet head is
1518                  * never delivered to user.
1519                  */
1520                 if (sk->sk_type != SOCK_DGRAM)
1521                         skb_push(skb, skb->data - skb_mac_header(skb));
1522                 else if (skb->pkt_type == PACKET_OUTGOING) {
1523                         /* Special case: outgoing packets have ll header at head */
1524                         skb_pull(skb, skb_network_offset(skb));
1525                 }
1526         }
1527
1528         snaplen = skb->len;
1529
1530         res = run_filter(skb, sk, snaplen);
1531         if (!res)
1532                 goto drop_n_restore;
1533         if (snaplen > res)
1534                 snaplen = res;
1535
1536         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1537                 goto drop_n_acct;
1538
1539         if (skb_shared(skb)) {
1540                 struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1541                 if (nskb == NULL)
1542                         goto drop_n_acct;
1543
1544                 if (skb_head != skb->data) {
1545                         skb->data = skb_head;
1546                         skb->len = skb_len;
1547                 }
1548                 consume_skb(skb);
1549                 skb = nskb;
1550         }
1551
1552         BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1553                      sizeof(skb->cb));
1554
1555         sll = &PACKET_SKB_CB(skb)->sa.ll;
1556         sll->sll_family = AF_PACKET;
1557         sll->sll_hatype = dev->type;
1558         sll->sll_protocol = skb->protocol;
1559         sll->sll_pkttype = skb->pkt_type;
1560         if (unlikely(po->origdev))
1561                 sll->sll_ifindex = orig_dev->ifindex;
1562         else
1563                 sll->sll_ifindex = dev->ifindex;
1564
1565         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1566
1567         PACKET_SKB_CB(skb)->origlen = skb->len;
1568
1569         if (pskb_trim(skb, snaplen))
1570                 goto drop_n_acct;
1571
1572         skb_set_owner_r(skb, sk);
1573         skb->dev = NULL;
1574         skb_dst_drop(skb);
1575
1576         /* drop conntrack reference */
1577         nf_reset(skb);
1578
1579         spin_lock(&sk->sk_receive_queue.lock);
1580         po->stats.tp_packets++;
1581         skb->dropcount = atomic_read(&sk->sk_drops);
1582         __skb_queue_tail(&sk->sk_receive_queue, skb);
1583         spin_unlock(&sk->sk_receive_queue.lock);
1584         sk->sk_data_ready(sk, skb->len);
1585         return 0;
1586
1587 drop_n_acct:
1588         spin_lock(&sk->sk_receive_queue.lock);
1589         po->stats.tp_drops++;
1590         atomic_inc(&sk->sk_drops);
1591         spin_unlock(&sk->sk_receive_queue.lock);
1592
1593 drop_n_restore:
1594         if (skb_head != skb->data && skb_shared(skb)) {
1595                 skb->data = skb_head;
1596                 skb->len = skb_len;
1597         }
1598 drop:
1599         consume_skb(skb);
1600         return 0;
1601 }
1602
1603 static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1604                        struct packet_type *pt, struct net_device *orig_dev)
1605 {
1606         struct sock *sk;
1607         struct packet_sock *po;
1608         struct sockaddr_ll *sll;
1609         union {
1610                 struct tpacket_hdr *h1;
1611                 struct tpacket2_hdr *h2;
1612                 struct tpacket3_hdr *h3;
1613                 void *raw;
1614         } h;
1615         u8 *skb_head = skb->data;
1616         int skb_len = skb->len;
1617         unsigned int snaplen, res;
1618         unsigned long status = TP_STATUS_USER;
1619         unsigned short macoff, netoff, hdrlen;
1620         struct sk_buff *copy_skb = NULL;
1621         struct timeval tv;
1622         struct timespec ts;
1623         struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
1624
1625         if (skb->pkt_type == PACKET_LOOPBACK)
1626                 goto drop;
1627
1628         sk = pt->af_packet_priv;
1629         po = pkt_sk(sk);
1630
1631         if (!net_eq(dev_net(dev), sock_net(sk)))
1632                 goto drop;
1633
1634         if (dev->header_ops) {
1635                 if (sk->sk_type != SOCK_DGRAM)
1636                         skb_push(skb, skb->data - skb_mac_header(skb));
1637                 else if (skb->pkt_type == PACKET_OUTGOING) {
1638                         /* Special case: outgoing packets have ll header at head */
1639                         skb_pull(skb, skb_network_offset(skb));
1640                 }
1641         }
1642
1643         if (skb->ip_summed == CHECKSUM_PARTIAL)
1644                 status |= TP_STATUS_CSUMNOTREADY;
1645
1646         snaplen = skb->len;
1647
1648         res = run_filter(skb, sk, snaplen);
1649         if (!res)
1650                 goto drop_n_restore;
1651         if (snaplen > res)
1652                 snaplen = res;
1653
1654         if (sk->sk_type == SOCK_DGRAM) {
1655                 macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1656                                   po->tp_reserve;
1657         } else {
1658                 unsigned int maclen = skb_network_offset(skb);
1659                 netoff = TPACKET_ALIGN(po->tp_hdrlen +
1660                                        (maclen < 16 ? 16 : maclen)) +
1661                         po->tp_reserve;
1662                 macoff = netoff - maclen;
1663         }
1664         if (po->tp_version <= TPACKET_V2) {
1665                 if (macoff + snaplen > po->rx_ring.frame_size) {
1666                         if (po->copy_thresh &&
1667                             atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1668                                 if (skb_shared(skb)) {
1669                                         copy_skb = skb_clone(skb, GFP_ATOMIC);
1670                                 } else {
1671                                         copy_skb = skb_get(skb);
1672                                         skb_head = skb->data;
1673                                 }
1674                                 if (copy_skb)
1675                                         skb_set_owner_r(copy_skb, sk);
1676                         }
1677                         snaplen = po->rx_ring.frame_size - macoff;
1678                         if ((int)snaplen < 0)
1679                                 snaplen = 0;
1680                 }
1681         }
1682         spin_lock(&sk->sk_receive_queue.lock);
1683         h.raw = packet_current_rx_frame(po, skb,
1684                                         TP_STATUS_KERNEL, (macoff+snaplen));
1685         if (!h.raw)
1686                 goto ring_is_full;
1687         if (po->tp_version <= TPACKET_V2) {
1688                 packet_increment_rx_head(po, &po->rx_ring);
1689         /*
1690          * LOSING will be reported till you read the stats,
1691          * because it's COR - Clear On Read.
1692          * Anyways, moving it for V1/V2 only as V3 doesn't need this
1693          * at packet level.
1694          */
1695                 if (po->stats.tp_drops)
1696                         status |= TP_STATUS_LOSING;
1697         }
1698         po->stats.tp_packets++;
1699         if (copy_skb) {
1700                 status |= TP_STATUS_COPY;
1701                 __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1702         }
1703         spin_unlock(&sk->sk_receive_queue.lock);
1704
1705         skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1706
1707         switch (po->tp_version) {
1708         case TPACKET_V1:
1709                 h.h1->tp_len = skb->len;
1710                 h.h1->tp_snaplen = snaplen;
1711                 h.h1->tp_mac = macoff;
1712                 h.h1->tp_net = netoff;
1713                 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1714                                 && shhwtstamps->syststamp.tv64)
1715                         tv = ktime_to_timeval(shhwtstamps->syststamp);
1716                 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1717                                 && shhwtstamps->hwtstamp.tv64)
1718                         tv = ktime_to_timeval(shhwtstamps->hwtstamp);
1719                 else if (skb->tstamp.tv64)
1720                         tv = ktime_to_timeval(skb->tstamp);
1721                 else
1722                         do_gettimeofday(&tv);
1723                 h.h1->tp_sec = tv.tv_sec;
1724                 h.h1->tp_usec = tv.tv_usec;
1725                 hdrlen = sizeof(*h.h1);
1726                 break;
1727         case TPACKET_V2:
1728                 h.h2->tp_len = skb->len;
1729                 h.h2->tp_snaplen = snaplen;
1730                 h.h2->tp_mac = macoff;
1731                 h.h2->tp_net = netoff;
1732                 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1733                                 && shhwtstamps->syststamp.tv64)
1734                         ts = ktime_to_timespec(shhwtstamps->syststamp);
1735                 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1736                                 && shhwtstamps->hwtstamp.tv64)
1737                         ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1738                 else if (skb->tstamp.tv64)
1739                         ts = ktime_to_timespec(skb->tstamp);
1740                 else
1741                         getnstimeofday(&ts);
1742                 h.h2->tp_sec = ts.tv_sec;
1743                 h.h2->tp_nsec = ts.tv_nsec;
1744                 if (vlan_tx_tag_present(skb)) {
1745                         h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1746                         status |= TP_STATUS_VLAN_VALID;
1747                 } else {
1748                         h.h2->tp_vlan_tci = 0;
1749                 }
1750                 h.h2->tp_padding = 0;
1751                 hdrlen = sizeof(*h.h2);
1752                 break;
1753         case TPACKET_V3:
1754                 /* tp_nxt_offset,vlan are already populated above.
1755                  * So DONT clear those fields here
1756                  */
1757                 h.h3->tp_status |= status;
1758                 h.h3->tp_len = skb->len;
1759                 h.h3->tp_snaplen = snaplen;
1760                 h.h3->tp_mac = macoff;
1761                 h.h3->tp_net = netoff;
1762                 if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1763                                 && shhwtstamps->syststamp.tv64)
1764                         ts = ktime_to_timespec(shhwtstamps->syststamp);
1765                 else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1766                                 && shhwtstamps->hwtstamp.tv64)
1767                         ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1768                 else if (skb->tstamp.tv64)
1769                         ts = ktime_to_timespec(skb->tstamp);
1770                 else
1771                         getnstimeofday(&ts);
1772                 h.h3->tp_sec  = ts.tv_sec;
1773                 h.h3->tp_nsec = ts.tv_nsec;
1774                 hdrlen = sizeof(*h.h3);
1775                 break;
1776         default:
1777                 BUG();
1778         }
1779
1780         sll = h.raw + TPACKET_ALIGN(hdrlen);
1781         sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1782         sll->sll_family = AF_PACKET;
1783         sll->sll_hatype = dev->type;
1784         sll->sll_protocol = skb->protocol;
1785         sll->sll_pkttype = skb->pkt_type;
1786         if (unlikely(po->origdev))
1787                 sll->sll_ifindex = orig_dev->ifindex;
1788         else
1789                 sll->sll_ifindex = dev->ifindex;
1790
1791         smp_mb();
1792 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1793         {
1794                 u8 *start, *end;
1795
1796                 if (po->tp_version <= TPACKET_V2) {
1797                         end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1798                                 + macoff + snaplen);
1799                         for (start = h.raw; start < end; start += PAGE_SIZE)
1800                                 flush_dcache_page(pgv_to_page(start));
1801                 }
1802                 smp_wmb();
1803         }
1804 #endif
1805         if (po->tp_version <= TPACKET_V2)
1806                 __packet_set_status(po, h.raw, status);
1807         else
1808                 prb_clear_blk_fill_status(&po->rx_ring);
1809
1810         sk->sk_data_ready(sk, 0);
1811
1812 drop_n_restore:
1813         if (skb_head != skb->data && skb_shared(skb)) {
1814                 skb->data = skb_head;
1815                 skb->len = skb_len;
1816         }
1817 drop:
1818         kfree_skb(skb);
1819         return 0;
1820
1821 ring_is_full:
1822         po->stats.tp_drops++;
1823         spin_unlock(&sk->sk_receive_queue.lock);
1824
1825         sk->sk_data_ready(sk, 0);
1826         kfree_skb(copy_skb);
1827         goto drop_n_restore;
1828 }
1829
1830 static void tpacket_destruct_skb(struct sk_buff *skb)
1831 {
1832         struct packet_sock *po = pkt_sk(skb->sk);
1833         void *ph;
1834
1835         if (likely(po->tx_ring.pg_vec)) {
1836                 ph = skb_shinfo(skb)->destructor_arg;
1837                 BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1838                 atomic_dec(&po->tx_ring.pending);
1839                 __packet_set_status(po, ph, TP_STATUS_AVAILABLE);
1840         }
1841
1842         sock_wfree(skb);
1843 }
1844
1845 static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1846                 void *frame, struct net_device *dev, int size_max,
1847                 __be16 proto, unsigned char *addr, int hlen)
1848 {
1849         union {
1850                 struct tpacket_hdr *h1;
1851                 struct tpacket2_hdr *h2;
1852                 void *raw;
1853         } ph;
1854         int to_write, offset, len, tp_len, nr_frags, len_max;
1855         struct socket *sock = po->sk.sk_socket;
1856         struct page *page;
1857         void *data;
1858         int err;
1859
1860         ph.raw = frame;
1861
1862         skb->protocol = proto;
1863         skb->dev = dev;
1864         skb->priority = po->sk.sk_priority;
1865         skb->mark = po->sk.sk_mark;
1866         skb_shinfo(skb)->destructor_arg = ph.raw;
1867
1868         switch (po->tp_version) {
1869         case TPACKET_V2:
1870                 tp_len = ph.h2->tp_len;
1871                 break;
1872         default:
1873                 tp_len = ph.h1->tp_len;
1874                 break;
1875         }
1876         if (unlikely(tp_len > size_max)) {
1877                 pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1878                 return -EMSGSIZE;
1879         }
1880
1881         skb_reserve(skb, hlen);
1882         skb_reset_network_header(skb);
1883
1884         data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
1885         to_write = tp_len;
1886
1887         if (sock->type == SOCK_DGRAM) {
1888                 err = dev_hard_header(skb, dev, ntohs(proto), addr,
1889                                 NULL, tp_len);
1890                 if (unlikely(err < 0))
1891                         return -EINVAL;
1892         } else if (dev->hard_header_len) {
1893                 /* net device doesn't like empty head */
1894                 if (unlikely(tp_len <= dev->hard_header_len)) {
1895                         pr_err("packet size is too short (%d < %d)\n",
1896                                tp_len, dev->hard_header_len);
1897                         return -EINVAL;
1898                 }
1899
1900                 skb_push(skb, dev->hard_header_len);
1901                 err = skb_store_bits(skb, 0, data,
1902                                 dev->hard_header_len);
1903                 if (unlikely(err))
1904                         return err;
1905
1906                 data += dev->hard_header_len;
1907                 to_write -= dev->hard_header_len;
1908         }
1909
1910         err = -EFAULT;
1911         offset = offset_in_page(data);
1912         len_max = PAGE_SIZE - offset;
1913         len = ((to_write > len_max) ? len_max : to_write);
1914
1915         skb->data_len = to_write;
1916         skb->len += to_write;
1917         skb->truesize += to_write;
1918         atomic_add(to_write, &po->sk.sk_wmem_alloc);
1919
1920         while (likely(to_write)) {
1921                 nr_frags = skb_shinfo(skb)->nr_frags;
1922
1923                 if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
1924                         pr_err("Packet exceed the number of skb frags(%lu)\n",
1925                                MAX_SKB_FRAGS);
1926                         return -EFAULT;
1927                 }
1928
1929                 page = pgv_to_page(data);
1930                 data += len;
1931                 flush_dcache_page(page);
1932                 get_page(page);
1933                 skb_fill_page_desc(skb, nr_frags, page, offset, len);
1934                 to_write -= len;
1935                 offset = 0;
1936                 len_max = PAGE_SIZE;
1937                 len = ((to_write > len_max) ? len_max : to_write);
1938         }
1939
1940         return tp_len;
1941 }
1942
1943 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
1944 {
1945         struct sk_buff *skb;
1946         struct net_device *dev;
1947         __be16 proto;
1948         bool need_rls_dev = false;
1949         int err, reserve = 0;
1950         void *ph;
1951         struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
1952         int tp_len, size_max;
1953         unsigned char *addr;
1954         int len_sum = 0;
1955         int status = TP_STATUS_AVAILABLE;
1956         int hlen, tlen;
1957
1958         mutex_lock(&po->pg_vec_lock);
1959
1960         err = -EBUSY;
1961         if (saddr == NULL) {
1962                 dev = po->prot_hook.dev;
1963                 proto   = po->num;
1964                 addr    = NULL;
1965         } else {
1966                 err = -EINVAL;
1967                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
1968                         goto out;
1969                 if (msg->msg_namelen < (saddr->sll_halen
1970                                         + offsetof(struct sockaddr_ll,
1971                                                 sll_addr)))
1972                         goto out;
1973                 proto   = saddr->sll_protocol;
1974                 addr    = saddr->sll_addr;
1975                 dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
1976                 need_rls_dev = true;
1977         }
1978
1979         err = -ENXIO;
1980         if (unlikely(dev == NULL))
1981                 goto out;
1982
1983         reserve = dev->hard_header_len;
1984
1985         err = -ENETDOWN;
1986         if (unlikely(!(dev->flags & IFF_UP)))
1987                 goto out_put;
1988
1989         size_max = po->tx_ring.frame_size
1990                 - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
1991
1992         if (size_max > dev->mtu + reserve)
1993                 size_max = dev->mtu + reserve;
1994
1995         do {
1996                 ph = packet_current_frame(po, &po->tx_ring,
1997                                 TP_STATUS_SEND_REQUEST);
1998
1999                 if (unlikely(ph == NULL)) {
2000                         schedule();
2001                         continue;
2002                 }
2003
2004                 status = TP_STATUS_SEND_REQUEST;
2005                 hlen = LL_RESERVED_SPACE(dev);
2006                 tlen = dev->needed_tailroom;
2007                 skb = sock_alloc_send_skb(&po->sk,
2008                                 hlen + tlen + sizeof(struct sockaddr_ll),
2009                                 0, &err);
2010
2011                 if (unlikely(skb == NULL))
2012                         goto out_status;
2013
2014                 tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2015                                 addr, hlen);
2016
2017                 if (unlikely(tp_len < 0)) {
2018                         if (po->tp_loss) {
2019                                 __packet_set_status(po, ph,
2020                                                 TP_STATUS_AVAILABLE);
2021                                 packet_increment_head(&po->tx_ring);
2022                                 kfree_skb(skb);
2023                                 continue;
2024                         } else {
2025                                 status = TP_STATUS_WRONG_FORMAT;
2026                                 err = tp_len;
2027                                 goto out_status;
2028                         }
2029                 }
2030
2031                 skb->destructor = tpacket_destruct_skb;
2032                 __packet_set_status(po, ph, TP_STATUS_SENDING);
2033                 atomic_inc(&po->tx_ring.pending);
2034
2035                 status = TP_STATUS_SEND_REQUEST;
2036                 err = dev_queue_xmit(skb);
2037                 if (unlikely(err > 0)) {
2038                         err = net_xmit_errno(err);
2039                         if (err && __packet_get_status(po, ph) ==
2040                                    TP_STATUS_AVAILABLE) {
2041                                 /* skb was destructed already */
2042                                 skb = NULL;
2043                                 goto out_status;
2044                         }
2045                         /*
2046                          * skb was dropped but not destructed yet;
2047                          * let's treat it like congestion or err < 0
2048                          */
2049                         err = 0;
2050                 }
2051                 packet_increment_head(&po->tx_ring);
2052                 len_sum += tp_len;
2053         } while (likely((ph != NULL) ||
2054                         ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2055                          (atomic_read(&po->tx_ring.pending))))
2056                 );
2057
2058         err = len_sum;
2059         goto out_put;
2060
2061 out_status:
2062         __packet_set_status(po, ph, status);
2063         kfree_skb(skb);
2064 out_put:
2065         if (need_rls_dev)
2066                 dev_put(dev);
2067 out:
2068         mutex_unlock(&po->pg_vec_lock);
2069         return err;
2070 }
2071
2072 static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2073                                         size_t reserve, size_t len,
2074                                         size_t linear, int noblock,
2075                                         int *err)
2076 {
2077         struct sk_buff *skb;
2078
2079         /* Under a page?  Don't bother with paged skb. */
2080         if (prepad + len < PAGE_SIZE || !linear)
2081                 linear = len;
2082
2083         skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2084                                    err);
2085         if (!skb)
2086                 return NULL;
2087
2088         skb_reserve(skb, reserve);
2089         skb_put(skb, linear);
2090         skb->data_len = len - linear;
2091         skb->len += len - linear;
2092
2093         return skb;
2094 }
2095
2096 static int packet_snd(struct socket *sock,
2097                           struct msghdr *msg, size_t len)
2098 {
2099         struct sock *sk = sock->sk;
2100         struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2101         struct sk_buff *skb;
2102         struct net_device *dev;
2103         __be16 proto;
2104         bool need_rls_dev = false;
2105         unsigned char *addr;
2106         int err, reserve = 0;
2107         struct virtio_net_hdr vnet_hdr = { 0 };
2108         int offset = 0;
2109         int vnet_hdr_len;
2110         struct packet_sock *po = pkt_sk(sk);
2111         unsigned short gso_type = 0;
2112         int hlen, tlen;
2113         int extra_len = 0;
2114
2115         /*
2116          *      Get and verify the address.
2117          */
2118
2119         if (saddr == NULL) {
2120                 dev = po->prot_hook.dev;
2121                 proto   = po->num;
2122                 addr    = NULL;
2123         } else {
2124                 err = -EINVAL;
2125                 if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2126                         goto out;
2127                 if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2128                         goto out;
2129                 proto   = saddr->sll_protocol;
2130                 addr    = saddr->sll_addr;
2131                 dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2132                 need_rls_dev = true;
2133         }
2134
2135         err = -ENXIO;
2136         if (dev == NULL)
2137                 goto out_unlock;
2138         if (sock->type == SOCK_RAW)
2139                 reserve = dev->hard_header_len;
2140
2141         err = -ENETDOWN;
2142         if (!(dev->flags & IFF_UP))
2143                 goto out_unlock;
2144
2145         if (po->has_vnet_hdr) {
2146                 vnet_hdr_len = sizeof(vnet_hdr);
2147
2148                 err = -EINVAL;
2149                 if (len < vnet_hdr_len)
2150                         goto out_unlock;
2151
2152                 len -= vnet_hdr_len;
2153
2154                 err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2155                                        vnet_hdr_len);
2156                 if (err < 0)
2157                         goto out_unlock;
2158
2159                 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2160                     (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2161                       vnet_hdr.hdr_len))
2162                         vnet_hdr.hdr_len = vnet_hdr.csum_start +
2163                                                  vnet_hdr.csum_offset + 2;
2164
2165                 err = -EINVAL;
2166                 if (vnet_hdr.hdr_len > len)
2167                         goto out_unlock;
2168
2169                 if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2170                         switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2171                         case VIRTIO_NET_HDR_GSO_TCPV4:
2172                                 gso_type = SKB_GSO_TCPV4;
2173                                 break;
2174                         case VIRTIO_NET_HDR_GSO_TCPV6:
2175                                 gso_type = SKB_GSO_TCPV6;
2176                                 break;
2177                         case VIRTIO_NET_HDR_GSO_UDP:
2178                                 gso_type = SKB_GSO_UDP;
2179                                 break;
2180                         default:
2181                                 goto out_unlock;
2182                         }
2183
2184                         if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2185                                 gso_type |= SKB_GSO_TCP_ECN;
2186
2187                         if (vnet_hdr.gso_size == 0)
2188                                 goto out_unlock;
2189
2190                 }
2191         }
2192
2193         if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2194                 if (!netif_supports_nofcs(dev)) {
2195                         err = -EPROTONOSUPPORT;
2196                         goto out_unlock;
2197                 }
2198                 extra_len = 4; /* We're doing our own CRC */
2199         }
2200
2201         err = -EMSGSIZE;
2202         if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2203                 goto out_unlock;
2204
2205         err = -ENOBUFS;
2206         hlen = LL_RESERVED_SPACE(dev);
2207         tlen = dev->needed_tailroom;
2208         skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2209                                msg->msg_flags & MSG_DONTWAIT, &err);
2210         if (skb == NULL)
2211                 goto out_unlock;
2212
2213         skb_set_network_header(skb, reserve);
2214
2215         err = -EINVAL;
2216         if (sock->type == SOCK_DGRAM &&
2217             (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2218                 goto out_free;
2219
2220         /* Returns -EFAULT on error */
2221         err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2222         if (err)
2223                 goto out_free;
2224         err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2225         if (err < 0)
2226                 goto out_free;
2227
2228         if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2229                 /* Earlier code assumed this would be a VLAN pkt,
2230                  * double-check this now that we have the actual
2231                  * packet in hand.
2232                  */
2233                 struct ethhdr *ehdr;
2234                 skb_reset_mac_header(skb);
2235                 ehdr = eth_hdr(skb);
2236                 if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2237                         err = -EMSGSIZE;
2238                         goto out_free;
2239                 }
2240         }
2241
2242         skb->protocol = proto;
2243         skb->dev = dev;
2244         skb->priority = sk->sk_priority;
2245         skb->mark = sk->sk_mark;
2246
2247         if (po->has_vnet_hdr) {
2248                 if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2249                         if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2250                                                   vnet_hdr.csum_offset)) {
2251                                 err = -EINVAL;
2252                                 goto out_free;
2253                         }
2254                 }
2255
2256                 skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2257                 skb_shinfo(skb)->gso_type = gso_type;
2258
2259                 /* Header must be checked, and gso_segs computed. */
2260                 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2261                 skb_shinfo(skb)->gso_segs = 0;
2262
2263                 len += vnet_hdr_len;
2264         }
2265
2266         if (unlikely(extra_len == 4))
2267                 skb->no_fcs = 1;
2268
2269         /*
2270          *      Now send it
2271          */
2272
2273         err = dev_queue_xmit(skb);
2274         if (err > 0 && (err = net_xmit_errno(err)) != 0)
2275                 goto out_unlock;
2276
2277         if (need_rls_dev)
2278                 dev_put(dev);
2279
2280         return len;
2281
2282 out_free:
2283         kfree_skb(skb);
2284 out_unlock:
2285         if (dev && need_rls_dev)
2286                 dev_put(dev);
2287 out:
2288         return err;
2289 }
2290
2291 static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2292                 struct msghdr *msg, size_t len)
2293 {
2294         struct sock *sk = sock->sk;
2295         struct packet_sock *po = pkt_sk(sk);
2296         if (po->tx_ring.pg_vec)
2297                 return tpacket_snd(po, msg);
2298         else
2299                 return packet_snd(sock, msg, len);
2300 }
2301
2302 /*
2303  *      Close a PACKET socket. This is fairly simple. We immediately go
2304  *      to 'closed' state and remove our protocol entry in the device list.
2305  */
2306
2307 static int packet_release(struct socket *sock)
2308 {
2309         struct sock *sk = sock->sk;
2310         struct packet_sock *po;
2311         struct net *net;
2312         union tpacket_req_u req_u;
2313
2314         if (!sk)
2315                 return 0;
2316
2317         net = sock_net(sk);
2318         po = pkt_sk(sk);
2319
2320         mutex_lock(&net->packet.sklist_lock);
2321         sk_del_node_init_rcu(sk);
2322         mutex_unlock(&net->packet.sklist_lock);
2323
2324         preempt_disable();
2325         sock_prot_inuse_add(net, sk->sk_prot, -1);
2326         preempt_enable();
2327
2328         spin_lock(&po->bind_lock);
2329         unregister_prot_hook(sk, false);
2330         if (po->prot_hook.dev) {
2331                 dev_put(po->prot_hook.dev);
2332                 po->prot_hook.dev = NULL;
2333         }
2334         spin_unlock(&po->bind_lock);
2335
2336         packet_flush_mclist(sk);
2337
2338         memset(&req_u, 0, sizeof(req_u));
2339
2340         if (po->rx_ring.pg_vec)
2341                 packet_set_ring(sk, &req_u, 1, 0);
2342
2343         if (po->tx_ring.pg_vec)
2344                 packet_set_ring(sk, &req_u, 1, 1);
2345
2346         fanout_release(sk);
2347
2348         synchronize_net();
2349         /*
2350          *      Now the socket is dead. No more input will appear.
2351          */
2352         sock_orphan(sk);
2353         sock->sk = NULL;
2354
2355         /* Purge queues */
2356
2357         skb_queue_purge(&sk->sk_receive_queue);
2358         sk_refcnt_debug_release(sk);
2359
2360         sock_put(sk);
2361         return 0;
2362 }
2363
2364 /*
2365  *      Attach a packet hook.
2366  */
2367
2368 static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2369 {
2370         struct packet_sock *po = pkt_sk(sk);
2371
2372         if (po->fanout) {
2373                 if (dev)
2374                         dev_put(dev);
2375
2376                 return -EINVAL;
2377         }
2378
2379         lock_sock(sk);
2380
2381         spin_lock(&po->bind_lock);
2382         unregister_prot_hook(sk, true);
2383         po->num = protocol;
2384         po->prot_hook.type = protocol;
2385         if (po->prot_hook.dev)
2386                 dev_put(po->prot_hook.dev);
2387         po->prot_hook.dev = dev;
2388
2389         po->ifindex = dev ? dev->ifindex : 0;
2390
2391         if (protocol == 0)
2392                 goto out_unlock;
2393
2394         if (!dev || (dev->flags & IFF_UP)) {
2395                 register_prot_hook(sk);
2396         } else {
2397                 sk->sk_err = ENETDOWN;
2398                 if (!sock_flag(sk, SOCK_DEAD))
2399                         sk->sk_error_report(sk);
2400         }
2401
2402 out_unlock:
2403         spin_unlock(&po->bind_lock);
2404         release_sock(sk);
2405         return 0;
2406 }
2407
2408 /*
2409  *      Bind a packet socket to a device
2410  */
2411
2412 static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2413                             int addr_len)
2414 {
2415         struct sock *sk = sock->sk;
2416         char name[15];
2417         struct net_device *dev;
2418         int err = -ENODEV;
2419
2420         /*
2421          *      Check legality
2422          */
2423
2424         if (addr_len != sizeof(struct sockaddr))
2425                 return -EINVAL;
2426         strlcpy(name, uaddr->sa_data, sizeof(name));
2427
2428         dev = dev_get_by_name(sock_net(sk), name);
2429         if (dev)
2430                 err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2431         return err;
2432 }
2433
2434 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2435 {
2436         struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2437         struct sock *sk = sock->sk;
2438         struct net_device *dev = NULL;
2439         int err;
2440
2441
2442         /*
2443          *      Check legality
2444          */
2445
2446         if (addr_len < sizeof(struct sockaddr_ll))
2447                 return -EINVAL;
2448         if (sll->sll_family != AF_PACKET)
2449                 return -EINVAL;
2450
2451         if (sll->sll_ifindex) {
2452                 err = -ENODEV;
2453                 dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2454                 if (dev == NULL)
2455                         goto out;
2456         }
2457         err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2458
2459 out:
2460         return err;
2461 }
2462
2463 static struct proto packet_proto = {
2464         .name     = "PACKET",
2465         .owner    = THIS_MODULE,
2466         .obj_size = sizeof(struct packet_sock),
2467 };
2468
2469 /*
2470  *      Create a packet of type SOCK_PACKET.
2471  */
2472
2473 static int packet_create(struct net *net, struct socket *sock, int protocol,
2474                          int kern)
2475 {
2476         struct sock *sk;
2477         struct packet_sock *po;
2478         __be16 proto = (__force __be16)protocol; /* weird, but documented */
2479         int err;
2480
2481         if (!capable(CAP_NET_RAW))
2482                 return -EPERM;
2483         if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2484             sock->type != SOCK_PACKET)
2485                 return -ESOCKTNOSUPPORT;
2486
2487         sock->state = SS_UNCONNECTED;
2488
2489         err = -ENOBUFS;
2490         sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2491         if (sk == NULL)
2492                 goto out;
2493
2494         sock->ops = &packet_ops;
2495         if (sock->type == SOCK_PACKET)
2496                 sock->ops = &packet_ops_spkt;
2497
2498         sock_init_data(sock, sk);
2499
2500         po = pkt_sk(sk);
2501         sk->sk_family = PF_PACKET;
2502         po->num = proto;
2503
2504         sk->sk_destruct = packet_sock_destruct;
2505         sk_refcnt_debug_inc(sk);
2506
2507         /*
2508          *      Attach a protocol block
2509          */
2510
2511         spin_lock_init(&po->bind_lock);
2512         mutex_init(&po->pg_vec_lock);
2513         po->prot_hook.func = packet_rcv;
2514
2515         if (sock->type == SOCK_PACKET)
2516                 po->prot_hook.func = packet_rcv_spkt;
2517
2518         po->prot_hook.af_packet_priv = sk;
2519
2520         if (proto) {
2521                 po->prot_hook.type = proto;
2522                 register_prot_hook(sk);
2523         }
2524
2525         mutex_lock(&net->packet.sklist_lock);
2526         sk_add_node_rcu(sk, &net->packet.sklist);
2527         mutex_unlock(&net->packet.sklist_lock);
2528
2529         preempt_disable();
2530         sock_prot_inuse_add(net, &packet_proto, 1);
2531         preempt_enable();
2532
2533         return 0;
2534 out:
2535         return err;
2536 }
2537
2538 static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
2539 {
2540         struct sock_exterr_skb *serr;
2541         struct sk_buff *skb, *skb2;
2542         int copied, err;
2543
2544         err = -EAGAIN;
2545         skb = skb_dequeue(&sk->sk_error_queue);
2546         if (skb == NULL)
2547                 goto out;
2548
2549         copied = skb->len;
2550         if (copied > len) {
2551                 msg->msg_flags |= MSG_TRUNC;
2552                 copied = len;
2553         }
2554         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2555         if (err)
2556                 goto out_free_skb;
2557
2558         sock_recv_timestamp(msg, sk, skb);
2559
2560         serr = SKB_EXT_ERR(skb);
2561         put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP,
2562                  sizeof(serr->ee), &serr->ee);
2563
2564         msg->msg_flags |= MSG_ERRQUEUE;
2565         err = copied;
2566
2567         /* Reset and regenerate socket error */
2568         spin_lock_bh(&sk->sk_error_queue.lock);
2569         sk->sk_err = 0;
2570         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2571                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2572                 spin_unlock_bh(&sk->sk_error_queue.lock);
2573                 sk->sk_error_report(sk);
2574         } else
2575                 spin_unlock_bh(&sk->sk_error_queue.lock);
2576
2577 out_free_skb:
2578         kfree_skb(skb);
2579 out:
2580         return err;
2581 }
2582
2583 /*
2584  *      Pull a packet from our receive queue and hand it to the user.
2585  *      If necessary we block.
2586  */
2587
2588 static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2589                           struct msghdr *msg, size_t len, int flags)
2590 {
2591         struct sock *sk = sock->sk;
2592         struct sk_buff *skb;
2593         int copied, err;
2594         struct sockaddr_ll *sll;
2595         int vnet_hdr_len = 0;
2596
2597         err = -EINVAL;
2598         if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2599                 goto out;
2600
2601 #if 0
2602         /* What error should we return now? EUNATTACH? */
2603         if (pkt_sk(sk)->ifindex < 0)
2604                 return -ENODEV;
2605 #endif
2606
2607         if (flags & MSG_ERRQUEUE) {
2608                 err = packet_recv_error(sk, msg, len);
2609                 goto out;
2610         }
2611
2612         /*
2613          *      Call the generic datagram receiver. This handles all sorts
2614          *      of horrible races and re-entrancy so we can forget about it
2615          *      in the protocol layers.
2616          *
2617          *      Now it will return ENETDOWN, if device have just gone down,
2618          *      but then it will block.
2619          */
2620
2621         skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2622
2623         /*
2624          *      An error occurred so return it. Because skb_recv_datagram()
2625          *      handles the blocking we don't see and worry about blocking
2626          *      retries.
2627          */
2628
2629         if (skb == NULL)
2630                 goto out;
2631
2632         if (pkt_sk(sk)->has_vnet_hdr) {
2633                 struct virtio_net_hdr vnet_hdr = { 0 };
2634
2635                 err = -EINVAL;
2636                 vnet_hdr_len = sizeof(vnet_hdr);
2637                 if (len < vnet_hdr_len)
2638                         goto out_free;
2639
2640                 len -= vnet_hdr_len;
2641
2642                 if (skb_is_gso(skb)) {
2643                         struct skb_shared_info *sinfo = skb_shinfo(skb);
2644
2645                         /* This is a hint as to how much should be linear. */
2646                         vnet_hdr.hdr_len = skb_headlen(skb);
2647                         vnet_hdr.gso_size = sinfo->gso_size;
2648                         if (sinfo->gso_type & SKB_GSO_TCPV4)
2649                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2650                         else if (sinfo->gso_type & SKB_GSO_TCPV6)
2651                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2652                         else if (sinfo->gso_type & SKB_GSO_UDP)
2653                                 vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2654                         else if (sinfo->gso_type & SKB_GSO_FCOE)
2655                                 goto out_free;
2656                         else
2657                                 BUG();
2658                         if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2659                                 vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2660                 } else
2661                         vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2662
2663                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
2664                         vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2665                         vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2666                         vnet_hdr.csum_offset = skb->csum_offset;
2667                 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2668                         vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2669                 } /* else everything is zero */
2670
2671                 err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2672                                      vnet_hdr_len);
2673                 if (err < 0)
2674                         goto out_free;
2675         }
2676
2677         /*
2678          *      If the address length field is there to be filled in, we fill
2679          *      it in now.
2680          */
2681
2682         sll = &PACKET_SKB_CB(skb)->sa.ll;
2683         if (sock->type == SOCK_PACKET)
2684                 msg->msg_namelen = sizeof(struct sockaddr_pkt);
2685         else
2686                 msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
2687
2688         /*
2689          *      You lose any data beyond the buffer you gave. If it worries a
2690          *      user program they can ask the device for its MTU anyway.
2691          */
2692
2693         copied = skb->len;
2694         if (copied > len) {
2695                 copied = len;
2696                 msg->msg_flags |= MSG_TRUNC;
2697         }
2698
2699         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2700         if (err)
2701                 goto out_free;
2702
2703         sock_recv_ts_and_drops(msg, sk, skb);
2704
2705         if (msg->msg_name)
2706                 memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2707                        msg->msg_namelen);
2708
2709         if (pkt_sk(sk)->auxdata) {
2710                 struct tpacket_auxdata aux;
2711
2712                 aux.tp_status = TP_STATUS_USER;
2713                 if (skb->ip_summed == CHECKSUM_PARTIAL)
2714                         aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2715                 aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2716                 aux.tp_snaplen = skb->len;
2717                 aux.tp_mac = 0;
2718                 aux.tp_net = skb_network_offset(skb);
2719                 if (vlan_tx_tag_present(skb)) {
2720                         aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2721                         aux.tp_status |= TP_STATUS_VLAN_VALID;
2722                 } else {
2723                         aux.tp_vlan_tci = 0;
2724                 }
2725                 aux.tp_padding = 0;
2726                 put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2727         }
2728
2729         /*
2730          *      Free or return the buffer as appropriate. Again this
2731          *      hides all the races and re-entrancy issues from us.
2732          */
2733         err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2734
2735 out_free:
2736         skb_free_datagram(sk, skb);
2737 out:
2738         return err;
2739 }
2740
2741 static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2742                                int *uaddr_len, int peer)
2743 {
2744         struct net_device *dev;
2745         struct sock *sk = sock->sk;
2746
2747         if (peer)
2748                 return -EOPNOTSUPP;
2749
2750         uaddr->sa_family = AF_PACKET;
2751         rcu_read_lock();
2752         dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2753         if (dev)
2754                 strncpy(uaddr->sa_data, dev->name, 14);
2755         else
2756                 memset(uaddr->sa_data, 0, 14);
2757         rcu_read_unlock();
2758         *uaddr_len = sizeof(*uaddr);
2759
2760         return 0;
2761 }
2762
2763 static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2764                           int *uaddr_len, int peer)
2765 {
2766         struct net_device *dev;
2767         struct sock *sk = sock->sk;
2768         struct packet_sock *po = pkt_sk(sk);
2769         DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2770
2771         if (peer)
2772                 return -EOPNOTSUPP;
2773
2774         sll->sll_family = AF_PACKET;
2775         sll->sll_ifindex = po->ifindex;
2776         sll->sll_protocol = po->num;
2777         sll->sll_pkttype = 0;
2778         rcu_read_lock();
2779         dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2780         if (dev) {
2781                 sll->sll_hatype = dev->type;
2782                 sll->sll_halen = dev->addr_len;
2783                 memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2784         } else {
2785                 sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
2786                 sll->sll_halen = 0;
2787         }
2788         rcu_read_unlock();
2789         *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2790
2791         return 0;
2792 }
2793
2794 static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2795                          int what)
2796 {
2797         switch (i->type) {
2798         case PACKET_MR_MULTICAST:
2799                 if (i->alen != dev->addr_len)
2800                         return -EINVAL;
2801                 if (what > 0)
2802                         return dev_mc_add(dev, i->addr);
2803                 else
2804                         return dev_mc_del(dev, i->addr);
2805                 break;
2806         case PACKET_MR_PROMISC:
2807                 return dev_set_promiscuity(dev, what);
2808                 break;
2809         case PACKET_MR_ALLMULTI:
2810                 return dev_set_allmulti(dev, what);
2811                 break;
2812         case PACKET_MR_UNICAST:
2813                 if (i->alen != dev->addr_len)
2814                         return -EINVAL;
2815                 if (what > 0)
2816                         return dev_uc_add(dev, i->addr);
2817                 else
2818                         return dev_uc_del(dev, i->addr);
2819                 break;
2820         default:
2821                 break;
2822         }
2823         return 0;
2824 }
2825
2826 static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2827 {
2828         for ( ; i; i = i->next) {
2829                 if (i->ifindex == dev->ifindex)
2830                         packet_dev_mc(dev, i, what);
2831         }
2832 }
2833
2834 static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2835 {
2836         struct packet_sock *po = pkt_sk(sk);
2837         struct packet_mclist *ml, *i;
2838         struct net_device *dev;
2839         int err;
2840
2841         rtnl_lock();
2842
2843         err = -ENODEV;
2844         dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2845         if (!dev)
2846                 goto done;
2847
2848         err = -EINVAL;
2849         if (mreq->mr_alen > dev->addr_len)
2850                 goto done;
2851
2852         err = -ENOBUFS;
2853         i = kmalloc(sizeof(*i), GFP_KERNEL);
2854         if (i == NULL)
2855                 goto done;
2856
2857         err = 0;
2858         for (ml = po->mclist; ml; ml = ml->next) {
2859                 if (ml->ifindex == mreq->mr_ifindex &&
2860                     ml->type == mreq->mr_type &&
2861                     ml->alen == mreq->mr_alen &&
2862                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2863                         ml->count++;
2864                         /* Free the new element ... */
2865                         kfree(i);
2866                         goto done;
2867                 }
2868         }
2869
2870         i->type = mreq->mr_type;
2871         i->ifindex = mreq->mr_ifindex;
2872         i->alen = mreq->mr_alen;
2873         memcpy(i->addr, mreq->mr_address, i->alen);
2874         i->count = 1;
2875         i->next = po->mclist;
2876         po->mclist = i;
2877         err = packet_dev_mc(dev, i, 1);
2878         if (err) {
2879                 po->mclist = i->next;
2880                 kfree(i);
2881         }
2882
2883 done:
2884         rtnl_unlock();
2885         return err;
2886 }
2887
2888 static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
2889 {
2890         struct packet_mclist *ml, **mlp;
2891
2892         rtnl_lock();
2893
2894         for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
2895                 if (ml->ifindex == mreq->mr_ifindex &&
2896                     ml->type == mreq->mr_type &&
2897                     ml->alen == mreq->mr_alen &&
2898                     memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2899                         if (--ml->count == 0) {
2900                                 struct net_device *dev;
2901                                 *mlp = ml->next;
2902                                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
2903                                 if (dev)
2904                                         packet_dev_mc(dev, ml, -1);
2905                                 kfree(ml);
2906                         }
2907                         rtnl_unlock();
2908                         return 0;
2909                 }
2910         }
2911         rtnl_unlock();
2912         return -EADDRNOTAVAIL;
2913 }
2914
2915 static void packet_flush_mclist(struct sock *sk)
2916 {
2917         struct packet_sock *po = pkt_sk(sk);
2918         struct packet_mclist *ml;
2919
2920         if (!po->mclist)
2921                 return;
2922
2923         rtnl_lock();
2924         while ((ml = po->mclist) != NULL) {
2925                 struct net_device *dev;
2926
2927                 po->mclist = ml->next;
2928                 dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
2929                 if (dev != NULL)
2930                         packet_dev_mc(dev, ml, -1);
2931                 kfree(ml);
2932         }
2933         rtnl_unlock();
2934 }
2935
2936 static int
2937 packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
2938 {
2939         struct sock *sk = sock->sk;
2940         struct packet_sock *po = pkt_sk(sk);
2941         int ret;
2942
2943         if (level != SOL_PACKET)
2944                 return -ENOPROTOOPT;
2945
2946         switch (optname) {
2947         case PACKET_ADD_MEMBERSHIP:
2948         case PACKET_DROP_MEMBERSHIP:
2949         {
2950                 struct packet_mreq_max mreq;
2951                 int len = optlen;
2952                 memset(&mreq, 0, sizeof(mreq));
2953                 if (len < sizeof(struct packet_mreq))
2954                         return -EINVAL;
2955                 if (len > sizeof(mreq))
2956                         len = sizeof(mreq);
2957                 if (copy_from_user(&mreq, optval, len))
2958                         return -EFAULT;
2959                 if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
2960                         return -EINVAL;
2961                 if (optname == PACKET_ADD_MEMBERSHIP)
2962                         ret = packet_mc_add(sk, &mreq);
2963                 else
2964                         ret = packet_mc_drop(sk, &mreq);
2965                 return ret;
2966         }
2967
2968         case PACKET_RX_RING:
2969         case PACKET_TX_RING:
2970         {
2971                 union tpacket_req_u req_u;
2972                 int len;
2973
2974                 switch (po->tp_version) {
2975                 case TPACKET_V1:
2976                 case TPACKET_V2:
2977                         len = sizeof(req_u.req);
2978                         break;
2979                 case TPACKET_V3:
2980                 default:
2981                         len = sizeof(req_u.req3);
2982                         break;
2983                 }
2984                 if (optlen < len)
2985                         return -EINVAL;
2986                 if (pkt_sk(sk)->has_vnet_hdr)
2987                         return -EINVAL;
2988                 if (copy_from_user(&req_u.req, optval, len))
2989                         return -EFAULT;
2990                 return packet_set_ring(sk, &req_u, 0,
2991                         optname == PACKET_TX_RING);
2992         }
2993         case PACKET_COPY_THRESH:
2994         {
2995                 int val;
2996
2997                 if (optlen != sizeof(val))
2998                         return -EINVAL;
2999                 if (copy_from_user(&val, optval, sizeof(val)))
3000                         return -EFAULT;
3001
3002                 pkt_sk(sk)->copy_thresh = val;
3003                 return 0;
3004         }
3005         case PACKET_VERSION:
3006         {
3007                 int val;
3008
3009                 if (optlen != sizeof(val))
3010                         return -EINVAL;
3011                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3012                         return -EBUSY;
3013                 if (copy_from_user(&val, optval, sizeof(val)))
3014                         return -EFAULT;
3015                 switch (val) {
3016                 case TPACKET_V1:
3017                 case TPACKET_V2:
3018                 case TPACKET_V3:
3019                         po->tp_version = val;
3020                         return 0;
3021                 default:
3022                         return -EINVAL;
3023                 }
3024         }
3025         case PACKET_RESERVE:
3026         {
3027                 unsigned int val;
3028
3029                 if (optlen != sizeof(val))
3030                         return -EINVAL;
3031                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3032                         return -EBUSY;
3033                 if (copy_from_user(&val, optval, sizeof(val)))
3034                         return -EFAULT;
3035                 po->tp_reserve = val;
3036                 return 0;
3037         }
3038         case PACKET_LOSS:
3039         {
3040                 unsigned int val;
3041
3042                 if (optlen != sizeof(val))
3043                         return -EINVAL;
3044                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3045                         return -EBUSY;
3046                 if (copy_from_user(&val, optval, sizeof(val)))
3047                         return -EFAULT;
3048                 po->tp_loss = !!val;
3049                 return 0;
3050         }
3051         case PACKET_AUXDATA:
3052         {
3053                 int val;
3054
3055                 if (optlen < sizeof(val))
3056                         return -EINVAL;
3057                 if (copy_from_user(&val, optval, sizeof(val)))
3058                         return -EFAULT;
3059
3060                 po->auxdata = !!val;
3061                 return 0;
3062         }
3063         case PACKET_ORIGDEV:
3064         {
3065                 int val;
3066
3067                 if (optlen < sizeof(val))
3068                         return -EINVAL;
3069                 if (copy_from_user(&val, optval, sizeof(val)))
3070                         return -EFAULT;
3071
3072                 po->origdev = !!val;
3073                 return 0;
3074         }
3075         case PACKET_VNET_HDR:
3076         {
3077                 int val;
3078
3079                 if (sock->type != SOCK_RAW)
3080                         return -EINVAL;
3081                 if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3082                         return -EBUSY;
3083                 if (optlen < sizeof(val))
3084                         return -EINVAL;
3085                 if (copy_from_user(&val, optval, sizeof(val)))
3086                         return -EFAULT;
3087
3088                 po->has_vnet_hdr = !!val;
3089                 return 0;
3090         }
3091         case PACKET_TIMESTAMP:
3092         {
3093                 int val;
3094
3095                 if (optlen != sizeof(val))
3096                         return -EINVAL;
3097                 if (copy_from_user(&val, optval, sizeof(val)))
3098                         return -EFAULT;
3099
3100                 po->tp_tstamp = val;
3101                 return 0;
3102         }
3103         case PACKET_FANOUT:
3104         {
3105                 int val;
3106
3107                 if (optlen != sizeof(val))
3108                         return -EINVAL;
3109                 if (copy_from_user(&val, optval, sizeof(val)))
3110                         return -EFAULT;
3111
3112                 return fanout_add(sk, val & 0xffff, val >> 16);
3113         }
3114         default:
3115                 return -ENOPROTOOPT;
3116         }
3117 }
3118
3119 static int packet_getsockopt(struct socket *sock, int level, int optname,
3120                              char __user *optval, int __user *optlen)
3121 {
3122         int len;
3123         int val, lv = sizeof(val);
3124         struct sock *sk = sock->sk;
3125         struct packet_sock *po = pkt_sk(sk);
3126         void *data = &val;
3127         struct tpacket_stats st;
3128         union tpacket_stats_u st_u;
3129
3130         if (level != SOL_PACKET)
3131                 return -ENOPROTOOPT;
3132
3133         if (get_user(len, optlen))
3134                 return -EFAULT;
3135
3136         if (len < 0)
3137                 return -EINVAL;
3138
3139         switch (optname) {
3140         case PACKET_STATISTICS:
3141                 spin_lock_bh(&sk->sk_receive_queue.lock);
3142                 if (po->tp_version == TPACKET_V3) {
3143                         lv = sizeof(struct tpacket_stats_v3);
3144                         memcpy(&st_u.stats3, &po->stats,
3145                                sizeof(struct tpacket_stats));
3146                         st_u.stats3.tp_freeze_q_cnt =
3147                                         po->stats_u.stats3.tp_freeze_q_cnt;
3148                         st_u.stats3.tp_packets += po->stats.tp_drops;
3149                         data = &st_u.stats3;
3150                 } else {
3151                         lv = sizeof(struct tpacket_stats);
3152                         st = po->stats;
3153                         st.tp_packets += st.tp_drops;
3154                         data = &st;
3155                 }
3156                 memset(&po->stats, 0, sizeof(st));
3157                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3158                 break;
3159         case PACKET_AUXDATA:
3160                 val = po->auxdata;
3161                 break;
3162         case PACKET_ORIGDEV:
3163                 val = po->origdev;
3164                 break;
3165         case PACKET_VNET_HDR:
3166                 val = po->has_vnet_hdr;
3167                 break;
3168         case PACKET_VERSION:
3169                 val = po->tp_version;
3170                 break;
3171         case PACKET_HDRLEN:
3172                 if (len > sizeof(int))
3173                         len = sizeof(int);
3174                 if (copy_from_user(&val, optval, len))
3175                         return -EFAULT;
3176                 switch (val) {
3177                 case TPACKET_V1:
3178                         val = sizeof(struct tpacket_hdr);
3179                         break;
3180                 case TPACKET_V2:
3181                         val = sizeof(struct tpacket2_hdr);
3182                         break;
3183                 case TPACKET_V3:
3184                         val = sizeof(struct tpacket3_hdr);
3185                         break;
3186                 default:
3187                         return -EINVAL;
3188                 }
3189                 break;
3190         case PACKET_RESERVE:
3191                 val = po->tp_reserve;
3192                 break;
3193         case PACKET_LOSS:
3194                 val = po->tp_loss;
3195                 break;
3196         case PACKET_TIMESTAMP:
3197                 val = po->tp_tstamp;
3198                 break;
3199         case PACKET_FANOUT:
3200                 val = (po->fanout ?
3201                        ((u32)po->fanout->id |
3202                         ((u32)po->fanout->type << 16)) :
3203                        0);
3204                 break;
3205         default:
3206                 return -ENOPROTOOPT;
3207         }
3208
3209         if (len > lv)
3210                 len = lv;
3211         if (put_user(len, optlen))
3212                 return -EFAULT;
3213         if (copy_to_user(optval, data, len))
3214                 return -EFAULT;
3215         return 0;
3216 }
3217
3218
3219 static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
3220 {
3221         struct sock *sk;
3222         struct hlist_node *node;
3223         struct net_device *dev = data;
3224         struct net *net = dev_net(dev);
3225
3226         rcu_read_lock();
3227         sk_for_each_rcu(sk, node, &net->packet.sklist) {
3228                 struct packet_sock *po = pkt_sk(sk);
3229
3230                 switch (msg) {
3231                 case NETDEV_UNREGISTER:
3232                         if (po->mclist)
3233                                 packet_dev_mclist(dev, po->mclist, -1);
3234                         /* fallthrough */
3235
3236                 case NETDEV_DOWN:
3237                         if (dev->ifindex == po->ifindex) {
3238                                 spin_lock(&po->bind_lock);
3239                                 if (po->running) {
3240                                         __unregister_prot_hook(sk, false);
3241                                         sk->sk_err = ENETDOWN;
3242                                         if (!sock_flag(sk, SOCK_DEAD))
3243                                                 sk->sk_error_report(sk);
3244                                 }
3245                                 if (msg == NETDEV_UNREGISTER) {
3246                                         po->ifindex = -1;
3247                                         if (po->prot_hook.dev)
3248                                                 dev_put(po->prot_hook.dev);
3249                                         po->prot_hook.dev = NULL;
3250                                 }
3251                                 spin_unlock(&po->bind_lock);
3252                         }
3253                         break;
3254                 case NETDEV_UP:
3255                         if (dev->ifindex == po->ifindex) {
3256                                 spin_lock(&po->bind_lock);
3257                                 if (po->num)
3258                                         register_prot_hook(sk);
3259                                 spin_unlock(&po->bind_lock);
3260                         }
3261                         break;
3262                 }
3263         }
3264         rcu_read_unlock();
3265         return NOTIFY_DONE;
3266 }
3267
3268
3269 static int packet_ioctl(struct socket *sock, unsigned int cmd,
3270                         unsigned long arg)
3271 {
3272         struct sock *sk = sock->sk;
3273
3274         switch (cmd) {
3275         case SIOCOUTQ:
3276         {
3277                 int amount = sk_wmem_alloc_get(sk);
3278
3279                 return put_user(amount, (int __user *)arg);
3280         }
3281         case SIOCINQ:
3282         {
3283                 struct sk_buff *skb;
3284                 int amount = 0;
3285
3286                 spin_lock_bh(&sk->sk_receive_queue.lock);
3287                 skb = skb_peek(&sk->sk_receive_queue);
3288                 if (skb)
3289                         amount = skb->len;
3290                 spin_unlock_bh(&sk->sk_receive_queue.lock);
3291                 return put_user(amount, (int __user *)arg);
3292         }
3293         case SIOCGSTAMP:
3294                 return sock_get_timestamp(sk, (struct timeval __user *)arg);
3295         case SIOCGSTAMPNS:
3296                 return sock_get_timestampns(sk, (struct timespec __user *)arg);
3297
3298 #ifdef CONFIG_INET
3299         case SIOCADDRT:
3300         case SIOCDELRT:
3301         case SIOCDARP:
3302         case SIOCGARP:
3303         case SIOCSARP:
3304         case SIOCGIFADDR:
3305         case SIOCSIFADDR:
3306         case SIOCGIFBRDADDR:
3307         case SIOCSIFBRDADDR:
3308         case SIOCGIFNETMASK:
3309         case SIOCSIFNETMASK:
3310         case SIOCGIFDSTADDR:
3311         case SIOCSIFDSTADDR:
3312         case SIOCSIFFLAGS:
3313                 return inet_dgram_ops.ioctl(sock, cmd, arg);
3314 #endif
3315
3316         default:
3317                 return -ENOIOCTLCMD;
3318         }
3319         return 0;
3320 }
3321
3322 static unsigned int packet_poll(struct file *file, struct socket *sock,
3323                                 poll_table *wait)
3324 {
3325         struct sock *sk = sock->sk;
3326         struct packet_sock *po = pkt_sk(sk);
3327         unsigned int mask = datagram_poll(file, sock, wait);
3328
3329         spin_lock_bh(&sk->sk_receive_queue.lock);
3330         if (po->rx_ring.pg_vec) {
3331                 if (!packet_previous_rx_frame(po, &po->rx_ring,
3332                         TP_STATUS_KERNEL))
3333                         mask |= POLLIN | POLLRDNORM;
3334         }
3335         spin_unlock_bh(&sk->sk_receive_queue.lock);
3336         spin_lock_bh(&sk->sk_write_queue.lock);
3337         if (po->tx_ring.pg_vec) {
3338                 if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3339                         mask |= POLLOUT | POLLWRNORM;
3340         }
3341         spin_unlock_bh(&sk->sk_write_queue.lock);
3342         return mask;
3343 }
3344
3345
3346 /* Dirty? Well, I still did not learn better way to account
3347  * for user mmaps.
3348  */
3349
3350 static void packet_mm_open(struct vm_area_struct *vma)
3351 {
3352         struct file *file = vma->vm_file;
3353         struct socket *sock = file->private_data;
3354         struct sock *sk = sock->sk;
3355
3356         if (sk)
3357                 atomic_inc(&pkt_sk(sk)->mapped);
3358 }
3359
3360 static void packet_mm_close(struct vm_area_struct *vma)
3361 {
3362         struct file *file = vma->vm_file;
3363         struct socket *sock = file->private_data;
3364         struct sock *sk = sock->sk;
3365
3366         if (sk)
3367                 atomic_dec(&pkt_sk(sk)->mapped);
3368 }
3369
3370 static const struct vm_operations_struct packet_mmap_ops = {
3371         .open   =       packet_mm_open,
3372         .close  =       packet_mm_close,
3373 };
3374
3375 static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3376                         unsigned int len)
3377 {
3378         int i;
3379
3380         for (i = 0; i < len; i++) {
3381                 if (likely(pg_vec[i].buffer)) {
3382                         if (is_vmalloc_addr(pg_vec[i].buffer))
3383                                 vfree(pg_vec[i].buffer);
3384                         else
3385                                 free_pages((unsigned long)pg_vec[i].buffer,
3386                                            order);
3387                         pg_vec[i].buffer = NULL;
3388                 }
3389         }
3390         kfree(pg_vec);
3391 }
3392
3393 static char *alloc_one_pg_vec_page(unsigned long order)
3394 {
3395         char *buffer = NULL;
3396         gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3397                           __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3398
3399         buffer = (char *) __get_free_pages(gfp_flags, order);
3400
3401         if (buffer)
3402                 return buffer;
3403
3404         /*
3405          * __get_free_pages failed, fall back to vmalloc
3406          */
3407         buffer = vzalloc((1 << order) * PAGE_SIZE);
3408
3409         if (buffer)
3410                 return buffer;
3411
3412         /*
3413          * vmalloc failed, lets dig into swap here
3414          */
3415         gfp_flags &= ~__GFP_NORETRY;
3416         buffer = (char *)__get_free_pages(gfp_flags, order);
3417         if (buffer)
3418                 return buffer;
3419
3420         /*
3421          * complete and utter failure
3422          */
3423         return NULL;
3424 }
3425
3426 static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3427 {
3428         unsigned int block_nr = req->tp_block_nr;
3429         struct pgv *pg_vec;
3430         int i;
3431
3432         pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3433         if (unlikely(!pg_vec))
3434                 goto out;
3435
3436         for (i = 0; i < block_nr; i++) {
3437                 pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3438                 if (unlikely(!pg_vec[i].buffer))
3439                         goto out_free_pgvec;
3440         }
3441
3442 out:
3443         return pg_vec;
3444
3445 out_free_pgvec:
3446         free_pg_vec(pg_vec, order, block_nr);
3447         pg_vec = NULL;
3448         goto out;
3449 }
3450
3451 static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3452                 int closing, int tx_ring)
3453 {
3454         struct pgv *pg_vec = NULL;
3455         struct packet_sock *po = pkt_sk(sk);
3456         int was_running, order = 0;
3457         struct packet_ring_buffer *rb;
3458         struct sk_buff_head *rb_queue;
3459         __be16 num;
3460         int err = -EINVAL;
3461         /* Added to avoid minimal code churn */
3462         struct tpacket_req *req = &req_u->req;
3463
3464         /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3465         if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3466                 WARN(1, "Tx-ring is not supported.\n");
3467                 goto out;
3468         }
3469
3470         rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3471         rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3472
3473         err = -EBUSY;
3474         if (!closing) {
3475                 if (atomic_read(&po->mapped))
3476                         goto out;
3477                 if (atomic_read(&rb->pending))
3478                         goto out;
3479         }
3480
3481         if (req->tp_block_nr) {
3482                 /* Sanity tests and some calculations */
3483                 err = -EBUSY;
3484                 if (unlikely(rb->pg_vec))
3485                         goto out;
3486
3487                 switch (po->tp_version) {
3488                 case TPACKET_V1:
3489                         po->tp_hdrlen = TPACKET_HDRLEN;
3490                         break;
3491                 case TPACKET_V2:
3492                         po->tp_hdrlen = TPACKET2_HDRLEN;
3493                         break;
3494                 case TPACKET_V3:
3495                         po->tp_hdrlen = TPACKET3_HDRLEN;
3496                         break;
3497                 }
3498
3499                 err = -EINVAL;
3500                 if (unlikely((int)req->tp_block_size <= 0))
3501                         goto out;
3502                 if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3503                         goto out;
3504                 if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3505                                         po->tp_reserve))
3506                         goto out;
3507                 if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3508                         goto out;
3509
3510                 rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3511                 if (unlikely(rb->frames_per_block <= 0))
3512                         goto out;
3513                 if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3514                                         req->tp_frame_nr))
3515                         goto out;
3516
3517                 err = -ENOMEM;
3518                 order = get_order(req->tp_block_size);
3519                 pg_vec = alloc_pg_vec(req, order);
3520                 if (unlikely(!pg_vec))
3521                         goto out;
3522                 switch (po->tp_version) {
3523                 case TPACKET_V3:
3524                 /* Transmit path is not supported. We checked
3525                  * it above but just being paranoid
3526                  */
3527                         if (!tx_ring)
3528                                 init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3529                                 break;
3530                 default:
3531                         break;
3532                 }
3533         }
3534         /* Done */
3535         else {
3536                 err = -EINVAL;
3537                 if (unlikely(req->tp_frame_nr))
3538                         goto out;
3539         }
3540
3541         lock_sock(sk);
3542
3543         /* Detach socket from network */
3544         spin_lock(&po->bind_lock);
3545         was_running = po->running;
3546         num = po->num;
3547         if (was_running) {
3548                 po->num = 0;
3549                 __unregister_prot_hook(sk, false);
3550         }
3551         spin_unlock(&po->bind_lock);
3552
3553         synchronize_net();
3554
3555         err = -EBUSY;
3556         mutex_lock(&po->pg_vec_lock);
3557         if (closing || atomic_read(&po->mapped) == 0) {
3558                 err = 0;
3559                 spin_lock_bh(&rb_queue->lock);
3560                 swap(rb->pg_vec, pg_vec);
3561                 rb->frame_max = (req->tp_frame_nr - 1);
3562                 rb->head = 0;
3563                 rb->frame_size = req->tp_frame_size;
3564                 spin_unlock_bh(&rb_queue->lock);
3565
3566                 swap(rb->pg_vec_order, order);
3567                 swap(rb->pg_vec_len, req->tp_block_nr);
3568
3569                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3570                 po->prot_hook.func = (po->rx_ring.pg_vec) ?
3571                                                 tpacket_rcv : packet_rcv;
3572                 skb_queue_purge(rb_queue);
3573                 if (atomic_read(&po->mapped))
3574                         pr_err("packet_mmap: vma is busy: %d\n",
3575                                atomic_read(&po->mapped));
3576         }
3577         mutex_unlock(&po->pg_vec_lock);
3578
3579         spin_lock(&po->bind_lock);
3580         if (was_running) {
3581                 po->num = num;
3582                 register_prot_hook(sk);
3583         }
3584         spin_unlock(&po->bind_lock);
3585         if (closing && (po->tp_version > TPACKET_V2)) {
3586                 /* Because we don't support block-based V3 on tx-ring */
3587                 if (!tx_ring)
3588                         prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3589         }
3590         release_sock(sk);
3591
3592         if (pg_vec)
3593                 free_pg_vec(pg_vec, order, req->tp_block_nr);
3594 out:
3595         return err;
3596 }
3597
3598 static int packet_mmap(struct file *file, struct socket *sock,
3599                 struct vm_area_struct *vma)
3600 {
3601         struct sock *sk = sock->sk;
3602         struct packet_sock *po = pkt_sk(sk);
3603         unsigned long size, expected_size;
3604         struct packet_ring_buffer *rb;
3605         unsigned long start;
3606         int err = -EINVAL;
3607         int i;
3608
3609         if (vma->vm_pgoff)
3610                 return -EINVAL;
3611
3612         mutex_lock(&po->pg_vec_lock);
3613
3614         expected_size = 0;
3615         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3616                 if (rb->pg_vec) {
3617                         expected_size += rb->pg_vec_len
3618                                                 * rb->pg_vec_pages
3619                                                 * PAGE_SIZE;
3620                 }
3621         }
3622
3623         if (expected_size == 0)
3624                 goto out;
3625
3626         size = vma->vm_end - vma->vm_start;
3627         if (size != expected_size)
3628                 goto out;
3629
3630         start = vma->vm_start;
3631         for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3632                 if (rb->pg_vec == NULL)
3633                         continue;
3634
3635                 for (i = 0; i < rb->pg_vec_len; i++) {
3636                         struct page *page;
3637                         void *kaddr = rb->pg_vec[i].buffer;
3638                         int pg_num;
3639
3640                         for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3641                                 page = pgv_to_page(kaddr);
3642                                 err = vm_insert_page(vma, start, page);
3643                                 if (unlikely(err))
3644                                         goto out;
3645                                 start += PAGE_SIZE;
3646                                 kaddr += PAGE_SIZE;
3647                         }
3648                 }
3649         }
3650
3651         atomic_inc(&po->mapped);
3652         vma->vm_ops = &packet_mmap_ops;
3653         err = 0;
3654
3655 out:
3656         mutex_unlock(&po->pg_vec_lock);
3657         return err;
3658 }
3659
3660 static const struct proto_ops packet_ops_spkt = {
3661         .family =       PF_PACKET,
3662         .owner =        THIS_MODULE,
3663         .release =      packet_release,
3664         .bind =         packet_bind_spkt,
3665         .connect =      sock_no_connect,
3666         .socketpair =   sock_no_socketpair,
3667         .accept =       sock_no_accept,
3668         .getname =      packet_getname_spkt,
3669         .poll =         datagram_poll,
3670         .ioctl =        packet_ioctl,
3671         .listen =       sock_no_listen,
3672         .shutdown =     sock_no_shutdown,
3673         .setsockopt =   sock_no_setsockopt,
3674         .getsockopt =   sock_no_getsockopt,
3675         .sendmsg =      packet_sendmsg_spkt,
3676         .recvmsg =      packet_recvmsg,
3677         .mmap =         sock_no_mmap,
3678         .sendpage =     sock_no_sendpage,
3679 };
3680
3681 static const struct proto_ops packet_ops = {
3682         .family =       PF_PACKET,
3683         .owner =        THIS_MODULE,
3684         .release =      packet_release,
3685         .bind =         packet_bind,
3686         .connect =      sock_no_connect,
3687         .socketpair =   sock_no_socketpair,
3688         .accept =       sock_no_accept,
3689         .getname =      packet_getname,
3690         .poll =         packet_poll,
3691         .ioctl =        packet_ioctl,
3692         .listen =       sock_no_listen,
3693         .shutdown =     sock_no_shutdown,
3694         .setsockopt =   packet_setsockopt,
3695         .getsockopt =   packet_getsockopt,
3696         .sendmsg =      packet_sendmsg,
3697         .recvmsg =      packet_recvmsg,
3698         .mmap =         packet_mmap,
3699         .sendpage =     sock_no_sendpage,
3700 };
3701
3702 static const struct net_proto_family packet_family_ops = {
3703         .family =       PF_PACKET,
3704         .create =       packet_create,
3705         .owner  =       THIS_MODULE,
3706 };
3707
3708 static struct notifier_block packet_netdev_notifier = {
3709         .notifier_call =        packet_notifier,
3710 };
3711
3712 #ifdef CONFIG_PROC_FS
3713
3714 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3715         __acquires(RCU)
3716 {
3717         struct net *net = seq_file_net(seq);
3718
3719         rcu_read_lock();
3720         return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3721 }
3722
3723 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3724 {
3725         struct net *net = seq_file_net(seq);
3726         return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3727 }
3728
3729 static void packet_seq_stop(struct seq_file *seq, void *v)
3730         __releases(RCU)
3731 {
3732         rcu_read_unlock();
3733 }
3734
3735 static int packet_seq_show(struct seq_file *seq, void *v)
3736 {
3737         if (v == SEQ_START_TOKEN)
3738                 seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
3739         else {
3740                 struct sock *s = sk_entry(v);
3741                 const struct packet_sock *po = pkt_sk(s);
3742
3743                 seq_printf(seq,
3744                            "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
3745                            s,
3746                            atomic_read(&s->sk_refcnt),
3747                            s->sk_type,
3748                            ntohs(po->num),
3749                            po->ifindex,
3750                            po->running,
3751                            atomic_read(&s->sk_rmem_alloc),
3752                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(s)),
3753                            sock_i_ino(s));
3754         }
3755
3756         return 0;
3757 }
3758
3759 static const struct seq_operations packet_seq_ops = {
3760         .start  = packet_seq_start,
3761         .next   = packet_seq_next,
3762         .stop   = packet_seq_stop,
3763         .show   = packet_seq_show,
3764 };
3765
3766 static int packet_seq_open(struct inode *inode, struct file *file)
3767 {
3768         return seq_open_net(inode, file, &packet_seq_ops,
3769                             sizeof(struct seq_net_private));
3770 }
3771
3772 static const struct file_operations packet_seq_fops = {
3773         .owner          = THIS_MODULE,
3774         .open           = packet_seq_open,
3775         .read           = seq_read,
3776         .llseek         = seq_lseek,
3777         .release        = seq_release_net,
3778 };
3779
3780 #endif
3781
3782 static int __net_init packet_net_init(struct net *net)
3783 {
3784         mutex_init(&net->packet.sklist_lock);
3785         INIT_HLIST_HEAD(&net->packet.sklist);
3786
3787         if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops))
3788                 return -ENOMEM;
3789
3790         return 0;
3791 }
3792
3793 static void __net_exit packet_net_exit(struct net *net)
3794 {
3795         proc_net_remove(net, "packet");
3796 }
3797
3798 static struct pernet_operations packet_net_ops = {
3799         .init = packet_net_init,
3800         .exit = packet_net_exit,
3801 };
3802
3803
3804 static void __exit packet_exit(void)
3805 {
3806         unregister_netdevice_notifier(&packet_netdev_notifier);
3807         unregister_pernet_subsys(&packet_net_ops);
3808         sock_unregister(PF_PACKET);
3809         proto_unregister(&packet_proto);
3810 }
3811
3812 static int __init packet_init(void)
3813 {
3814         int rc = proto_register(&packet_proto, 0);
3815
3816         if (rc != 0)
3817                 goto out;
3818
3819         sock_register(&packet_family_ops);
3820         register_pernet_subsys(&packet_net_ops);
3821         register_netdevice_notifier(&packet_netdev_notifier);
3822 out:
3823         return rc;
3824 }
3825
3826 module_init(packet_init);
3827 module_exit(packet_exit);
3828 MODULE_LICENSE("GPL");
3829 MODULE_ALIAS_NETPROTO(PF_PACKET);