linux/net/packet/af_packet.c
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   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
 109On receive:
 110-----------
 111
 112Incoming, dev->hard_header!=NULL
 113   mac_header -> ll header
 114   data       -> data
 115
 116Outgoing, dev->hard_header!=NULL
 117   mac_header -> ll header
 118   data       -> ll header
 119
 120Incoming, 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
 126Outgoing, dev->hard_header==NULL
 127   mac_header -> data. ll header is still not built!
 128   data       -> data
 129
 130Resume
 131  If dev->hard_header==NULL we are unlikely to restore sensible ll header.
 132
 133
 134On transmit:
 135------------
 136
 137dev->hard_header != NULL
 138   mac_header -> ll header
 139   data       -> ll header
 140
 141dev->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 */
 154struct 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
 161static 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
 182struct packet_sock;
 183static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
 184
 185static void *packet_previous_frame(struct packet_sock *po,
 186                struct packet_ring_buffer *rb,
 187                int status);
 188static void packet_increment_head(struct packet_ring_buffer *buff);
 189static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
 190                        struct tpacket_block_desc *);
 191static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
 192                        struct packet_sock *);
 193static void prb_retire_current_block(struct tpacket_kbdq_core *,
 194                struct packet_sock *, unsigned int status);
 195static int prb_queue_frozen(struct tpacket_kbdq_core *);
 196static void prb_open_block(struct tpacket_kbdq_core *,
 197                struct tpacket_block_desc *);
 198static void prb_retire_rx_blk_timer_expired(unsigned long);
 199static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
 200static void prb_init_blk_timer(struct packet_sock *,
 201                struct tpacket_kbdq_core *,
 202                void (*func) (unsigned long));
 203static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
 204static void prb_clear_rxhash(struct tpacket_kbdq_core *,
 205                struct tpacket3_hdr *);
 206static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
 207                struct tpacket3_hdr *);
 208static void packet_flush_mclist(struct sock *sk);
 209
 210struct 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
 229static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
 230static 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 */
 236static 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 */
 256static 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
 274static 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
 282static 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
 289static 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
 316static 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
 342static 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
 366static 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
 373static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 374{
 375        del_timer_sync(&pkc->retire_blk_timer);
 376}
 377
 378static 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
 393static 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
 403static 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
 414static 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
 457static 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
 463static 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 */
 499static 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 */
 529static 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
 591refresh_timer:
 592        _prb_refresh_rx_retire_blk_timer(pkc);
 593
 594out:
 595        spin_unlock(&po->sk.sk_receive_queue.lock);
 596}
 597
 598static 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 */
 641static 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
 676static 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 */
 688static 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 */
 751static 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 */
 766static 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
 791static 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
 822static 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
 828static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
 829{
 830        return pkc->reset_pending_on_curr_blk;
 831}
 832
 833static 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
 839static 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
 845static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
 846                        struct tpacket3_hdr *ppd)
 847{
 848        ppd->hv1.tp_rxhash = 0;
 849}
 850
 851static 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
 863static 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
 874static 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 */
 892static 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
 954static 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
 974static 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
 987static 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 */
 998static 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
1006static 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
1016static 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
1031static 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
1039static void packet_increment_head(struct packet_ring_buffer *buff)
1040{
1041        buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1042}
1043
1044static 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
1059static 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
1069static 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
1078static 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
1089static 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
1096static 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
1134DEFINE_MUTEX(fanout_mutex);
1135EXPORT_SYMBOL_GPL(fanout_mutex);
1136static LIST_HEAD(fanout_list);
1137
1138static 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
1149static 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
1165static 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
1173static 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        }
1242out:
1243        mutex_unlock(&fanout_mutex);
1244        return err;
1245}
1246
1247static 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
1267static const struct proto_ops packet_ops;
1268
1269static const struct proto_ops packet_ops_spkt;
1270
1271static 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
1331out:
1332        kfree_skb(skb);
1333oom:
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
1343static 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;
1371retry:
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
1457out_unlock:
1458        rcu_read_unlock();
1459out_free:
1460        kfree_skb(skb);
1461        return err;
1462}
1463
1464static 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
1491static 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
1587drop_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
1593drop_n_restore:
1594        if (skb_head != skb->data && skb_shared(skb)) {
1595                skb->data = skb_head;
1596                skb->len = skb_len;
1597        }
1598drop:
1599        consume_skb(skb);
1600        return 0;
1601}
1602
1603static 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
1812drop_n_restore:
1813        if (skb_head != skb->data && skb_shared(skb)) {
1814                skb->data = skb_head;
1815                skb->len = skb_len;
1816        }
1817drop:
1818        kfree_skb(skb);
1819        return 0;
1820
1821ring_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
1830static 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
1845static 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
1943static 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
2061out_status:
2062        __packet_set_status(po, ph, status);
2063        kfree_skb(skb);
2064out_put:
2065        if (need_rls_dev)
2066                dev_put(dev);
2067out:
2068        mutex_unlock(&po->pg_vec_lock);
2069        return err;
2070}
2071
2072static 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
2096static 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
2282out_free:
2283        kfree_skb(skb);
2284out_unlock:
2285        if (dev && need_rls_dev)
2286                dev_put(dev);
2287out:
2288        return err;
2289}
2290
2291static 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
2307static 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
2368static 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
2402out_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
2412static 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
2434static 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
2459out:
2460        return err;
2461}
2462
2463static 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
2473static 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;
2534out:
2535        return err;
2536}
2537
2538static 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
2577out_free_skb:
2578        kfree_skb(skb);
2579out:
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
2588static 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
2735out_free:
2736        skb_free_datagram(sk, skb);
2737out:
2738        return err;
2739}
2740
2741static 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
2763static 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
2794static 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
2826static 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
2834static 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
2883done:
2884        rtnl_unlock();
2885        return err;
2886}
2887
2888static 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
2915static 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
2936static int
2937packet_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
3119static 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
3219static 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
3269static 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
3322static 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
3350static 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
3360static 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
3370static const struct vm_operations_struct packet_mmap_ops = {
3371        .open   =       packet_mm_open,
3372        .close  =       packet_mm_close,
3373};
3374
3375static 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
3393static 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
3426static 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
3442out:
3443        return pg_vec;
3444
3445out_free_pgvec:
3446        free_pg_vec(pg_vec, order, block_nr);
3447        pg_vec = NULL;
3448        goto out;
3449}
3450
3451static 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);
3594out:
3595        return err;
3596}
3597
3598static 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
3655out:
3656        mutex_unlock(&po->pg_vec_lock);
3657        return err;
3658}
3659
3660static 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
3681static 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
3702static const struct net_proto_family packet_family_ops = {
3703        .family =       PF_PACKET,
3704        .create =       packet_create,
3705        .owner  =       THIS_MODULE,
3706};
3707
3708static struct notifier_block packet_netdev_notifier = {
3709        .notifier_call =        packet_notifier,
3710};
3711
3712#ifdef CONFIG_PROC_FS
3713
3714static 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
3723static 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
3729static void packet_seq_stop(struct seq_file *seq, void *v)
3730        __releases(RCU)
3731{
3732        rcu_read_unlock();
3733}
3734
3735static 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
3759static 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
3766static 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
3772static 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
3782static 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
3793static void __net_exit packet_net_exit(struct net *net)
3794{
3795        proc_net_remove(net, "packet");
3796}
3797
3798static struct pernet_operations packet_net_ops = {
3799        .init = packet_net_init,
3800        .exit = packet_net_exit,
3801};
3802
3803
3804static 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
3812static 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);
3822out:
3823        return rc;
3824}
3825
3826module_init(packet_init);
3827module_exit(packet_exit);
3828MODULE_LICENSE("GPL");
3829MODULE_ALIAS_NETPROTO(PF_PACKET);
3830
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