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/*
  97   Assumptions:
  98   - if device has no dev->hard_header routine, it adds and removes ll header
  99     inside itself. In this case ll header is invisible outside of device,
 100     but higher levels still should reserve dev->hard_header_len.
 101     Some devices are enough clever to reallocate skb, when header
 102     will not fit to reserved space (tunnel), another ones are silly
 103     (PPP).
 104   - packet socket receives packets with pulled ll header,
 105     so that SOCK_RAW should push it back.
 106
 107On receive:
 108-----------
 109
 110Incoming, dev->hard_header!=NULL
 111   mac_header -> ll header
 112   data       -> data
 113
 114Outgoing, dev->hard_header!=NULL
 115   mac_header -> ll header
 116   data       -> ll header
 117
 118Incoming, dev->hard_header==NULL
 119   mac_header -> UNKNOWN position. It is very likely, that it points to ll
 120                 header.  PPP makes it, that is wrong, because introduce
 121                 assymetry between rx and tx paths.
 122   data       -> data
 123
 124Outgoing, dev->hard_header==NULL
 125   mac_header -> data. ll header is still not built!
 126   data       -> data
 127
 128Resume
 129  If dev->hard_header==NULL we are unlikely to restore sensible ll header.
 130
 131
 132On transmit:
 133------------
 134
 135dev->hard_header != NULL
 136   mac_header -> ll header
 137   data       -> ll header
 138
 139dev->hard_header == NULL (ll header is added by device, we cannot control it)
 140   mac_header -> data
 141   data       -> data
 142
 143   We should set nh.raw on output to correct posistion,
 144   packet classifier depends on it.
 145 */
 146
 147/* Private packet socket structures. */
 148
 149struct packet_mclist {
 150        struct packet_mclist    *next;
 151        int                     ifindex;
 152        int                     count;
 153        unsigned short          type;
 154        unsigned short          alen;
 155        unsigned char           addr[MAX_ADDR_LEN];
 156};
 157/* identical to struct packet_mreq except it has
 158 * a longer address field.
 159 */
 160struct packet_mreq_max {
 161        int             mr_ifindex;
 162        unsigned short  mr_type;
 163        unsigned short  mr_alen;
 164        unsigned char   mr_address[MAX_ADDR_LEN];
 165};
 166
 167static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 168                int closing, int tx_ring);
 169
 170
 171#define V3_ALIGNMENT    (8)
 172
 173#define BLK_HDR_LEN     (ALIGN(sizeof(struct tpacket_block_desc), V3_ALIGNMENT))
 174
 175#define BLK_PLUS_PRIV(sz_of_priv) \
 176        (BLK_HDR_LEN + ALIGN((sz_of_priv), V3_ALIGNMENT))
 177
 178/* kbdq - kernel block descriptor queue */
 179struct tpacket_kbdq_core {
 180        struct pgv      *pkbdq;
 181        unsigned int    feature_req_word;
 182        unsigned int    hdrlen;
 183        unsigned char   reset_pending_on_curr_blk;
 184        unsigned char   delete_blk_timer;
 185        unsigned short  kactive_blk_num;
 186        unsigned short  blk_sizeof_priv;
 187
 188        /* last_kactive_blk_num:
 189         * trick to see if user-space has caught up
 190         * in order to avoid refreshing timer when every single pkt arrives.
 191         */
 192        unsigned short  last_kactive_blk_num;
 193
 194        char            *pkblk_start;
 195        char            *pkblk_end;
 196        int             kblk_size;
 197        unsigned int    knum_blocks;
 198        uint64_t        knxt_seq_num;
 199        char            *prev;
 200        char            *nxt_offset;
 201        struct sk_buff  *skb;
 202
 203        atomic_t        blk_fill_in_prog;
 204
 205        /* Default is set to 8ms */
 206#define DEFAULT_PRB_RETIRE_TOV  (8)
 207
 208        unsigned short  retire_blk_tov;
 209        unsigned short  version;
 210        unsigned long   tov_in_jiffies;
 211
 212        /* timer to retire an outstanding block */
 213        struct timer_list retire_blk_timer;
 214};
 215
 216#define PGV_FROM_VMALLOC 1
 217struct pgv {
 218        char *buffer;
 219};
 220
 221struct packet_ring_buffer {
 222        struct pgv              *pg_vec;
 223        unsigned int            head;
 224        unsigned int            frames_per_block;
 225        unsigned int            frame_size;
 226        unsigned int            frame_max;
 227
 228        unsigned int            pg_vec_order;
 229        unsigned int            pg_vec_pages;
 230        unsigned int            pg_vec_len;
 231
 232        struct tpacket_kbdq_core        prb_bdqc;
 233        atomic_t                pending;
 234};
 235
 236#define BLOCK_STATUS(x) ((x)->hdr.bh1.block_status)
 237#define BLOCK_NUM_PKTS(x)       ((x)->hdr.bh1.num_pkts)
 238#define BLOCK_O2FP(x)           ((x)->hdr.bh1.offset_to_first_pkt)
 239#define BLOCK_LEN(x)            ((x)->hdr.bh1.blk_len)
 240#define BLOCK_SNUM(x)           ((x)->hdr.bh1.seq_num)
 241#define BLOCK_O2PRIV(x) ((x)->offset_to_priv)
 242#define BLOCK_PRIV(x)           ((void *)((char *)(x) + BLOCK_O2PRIV(x)))
 243
 244struct packet_sock;
 245static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
 246
 247static void *packet_previous_frame(struct packet_sock *po,
 248                struct packet_ring_buffer *rb,
 249                int status);
 250static void packet_increment_head(struct packet_ring_buffer *buff);
 251static int prb_curr_blk_in_use(struct tpacket_kbdq_core *,
 252                        struct tpacket_block_desc *);
 253static void *prb_dispatch_next_block(struct tpacket_kbdq_core *,
 254                        struct packet_sock *);
 255static void prb_retire_current_block(struct tpacket_kbdq_core *,
 256                struct packet_sock *, unsigned int status);
 257static int prb_queue_frozen(struct tpacket_kbdq_core *);
 258static void prb_open_block(struct tpacket_kbdq_core *,
 259                struct tpacket_block_desc *);
 260static void prb_retire_rx_blk_timer_expired(unsigned long);
 261static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *);
 262static void prb_init_blk_timer(struct packet_sock *,
 263                struct tpacket_kbdq_core *,
 264                void (*func) (unsigned long));
 265static void prb_fill_rxhash(struct tpacket_kbdq_core *, struct tpacket3_hdr *);
 266static void prb_clear_rxhash(struct tpacket_kbdq_core *,
 267                struct tpacket3_hdr *);
 268static void prb_fill_vlan_info(struct tpacket_kbdq_core *,
 269                struct tpacket3_hdr *);
 270static void packet_flush_mclist(struct sock *sk);
 271
 272struct packet_fanout;
 273struct packet_sock {
 274        /* struct sock has to be the first member of packet_sock */
 275        struct sock             sk;
 276        struct packet_fanout    *fanout;
 277        struct tpacket_stats    stats;
 278        union  tpacket_stats_u  stats_u;
 279        struct packet_ring_buffer       rx_ring;
 280        struct packet_ring_buffer       tx_ring;
 281        int                     copy_thresh;
 282        spinlock_t              bind_lock;
 283        struct mutex            pg_vec_lock;
 284        unsigned int            running:1,      /* prot_hook is attached*/
 285                                auxdata:1,
 286                                origdev:1,
 287                                has_vnet_hdr:1;
 288        int                     ifindex;        /* bound device         */
 289        __be16                  num;
 290        struct packet_mclist    *mclist;
 291        atomic_t                mapped;
 292        enum tpacket_versions   tp_version;
 293        unsigned int            tp_hdrlen;
 294        unsigned int            tp_reserve;
 295        unsigned int            tp_loss:1;
 296        unsigned int            tp_tstamp;
 297        struct packet_type      prot_hook ____cacheline_aligned_in_smp;
 298};
 299
 300#define PACKET_FANOUT_MAX       256
 301
 302struct packet_fanout {
 303#ifdef CONFIG_NET_NS
 304        struct net              *net;
 305#endif
 306        unsigned int            num_members;
 307        u16                     id;
 308        u8                      type;
 309        u8                      defrag;
 310        atomic_t                rr_cur;
 311        struct list_head        list;
 312        struct sock             *arr[PACKET_FANOUT_MAX];
 313        spinlock_t              lock;
 314        atomic_t                sk_ref;
 315        struct packet_type      prot_hook ____cacheline_aligned_in_smp;
 316};
 317
 318struct packet_skb_cb {
 319        unsigned int origlen;
 320        union {
 321                struct sockaddr_pkt pkt;
 322                struct sockaddr_ll ll;
 323        } sa;
 324};
 325
 326#define PACKET_SKB_CB(__skb)    ((struct packet_skb_cb *)((__skb)->cb))
 327
 328#define GET_PBDQC_FROM_RB(x)    ((struct tpacket_kbdq_core *)(&(x)->prb_bdqc))
 329#define GET_PBLOCK_DESC(x, bid) \
 330        ((struct tpacket_block_desc *)((x)->pkbdq[(bid)].buffer))
 331#define GET_CURR_PBLOCK_DESC_FROM_CORE(x)       \
 332        ((struct tpacket_block_desc *)((x)->pkbdq[(x)->kactive_blk_num].buffer))
 333#define GET_NEXT_PRB_BLK_NUM(x) \
 334        (((x)->kactive_blk_num < ((x)->knum_blocks-1)) ? \
 335        ((x)->kactive_blk_num+1) : 0)
 336
 337static struct packet_sock *pkt_sk(struct sock *sk)
 338{
 339        return (struct packet_sock *)sk;
 340}
 341
 342static void __fanout_unlink(struct sock *sk, struct packet_sock *po);
 343static void __fanout_link(struct sock *sk, struct packet_sock *po);
 344
 345/* register_prot_hook must be invoked with the po->bind_lock held,
 346 * or from a context in which asynchronous accesses to the packet
 347 * socket is not possible (packet_create()).
 348 */
 349static void register_prot_hook(struct sock *sk)
 350{
 351        struct packet_sock *po = pkt_sk(sk);
 352        if (!po->running) {
 353                if (po->fanout)
 354                        __fanout_link(sk, po);
 355                else
 356                        dev_add_pack(&po->prot_hook);
 357                sock_hold(sk);
 358                po->running = 1;
 359        }
 360}
 361
 362/* {,__}unregister_prot_hook() must be invoked with the po->bind_lock
 363 * held.   If the sync parameter is true, we will temporarily drop
 364 * the po->bind_lock and do a synchronize_net to make sure no
 365 * asynchronous packet processing paths still refer to the elements
 366 * of po->prot_hook.  If the sync parameter is false, it is the
 367 * callers responsibility to take care of this.
 368 */
 369static void __unregister_prot_hook(struct sock *sk, bool sync)
 370{
 371        struct packet_sock *po = pkt_sk(sk);
 372
 373        po->running = 0;
 374        if (po->fanout)
 375                __fanout_unlink(sk, po);
 376        else
 377                __dev_remove_pack(&po->prot_hook);
 378        __sock_put(sk);
 379
 380        if (sync) {
 381                spin_unlock(&po->bind_lock);
 382                synchronize_net();
 383                spin_lock(&po->bind_lock);
 384        }
 385}
 386
 387static void unregister_prot_hook(struct sock *sk, bool sync)
 388{
 389        struct packet_sock *po = pkt_sk(sk);
 390
 391        if (po->running)
 392                __unregister_prot_hook(sk, sync);
 393}
 394
 395static inline __pure struct page *pgv_to_page(void *addr)
 396{
 397        if (is_vmalloc_addr(addr))
 398                return vmalloc_to_page(addr);
 399        return virt_to_page(addr);
 400}
 401
 402static void __packet_set_status(struct packet_sock *po, void *frame, int status)
 403{
 404        union {
 405                struct tpacket_hdr *h1;
 406                struct tpacket2_hdr *h2;
 407                void *raw;
 408        } h;
 409
 410        h.raw = frame;
 411        switch (po->tp_version) {
 412        case TPACKET_V1:
 413                h.h1->tp_status = status;
 414                flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 415                break;
 416        case TPACKET_V2:
 417                h.h2->tp_status = status;
 418                flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 419                break;
 420        case TPACKET_V3:
 421        default:
 422                WARN(1, "TPACKET version not supported.\n");
 423                BUG();
 424        }
 425
 426        smp_wmb();
 427}
 428
 429static int __packet_get_status(struct packet_sock *po, void *frame)
 430{
 431        union {
 432                struct tpacket_hdr *h1;
 433                struct tpacket2_hdr *h2;
 434                void *raw;
 435        } h;
 436
 437        smp_rmb();
 438
 439        h.raw = frame;
 440        switch (po->tp_version) {
 441        case TPACKET_V1:
 442                flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 443                return h.h1->tp_status;
 444        case TPACKET_V2:
 445                flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 446                return h.h2->tp_status;
 447        case TPACKET_V3:
 448        default:
 449                WARN(1, "TPACKET version not supported.\n");
 450                BUG();
 451                return 0;
 452        }
 453}
 454
 455static void *packet_lookup_frame(struct packet_sock *po,
 456                struct packet_ring_buffer *rb,
 457                unsigned int position,
 458                int status)
 459{
 460        unsigned int pg_vec_pos, frame_offset;
 461        union {
 462                struct tpacket_hdr *h1;
 463                struct tpacket2_hdr *h2;
 464                void *raw;
 465        } h;
 466
 467        pg_vec_pos = position / rb->frames_per_block;
 468        frame_offset = position % rb->frames_per_block;
 469
 470        h.raw = rb->pg_vec[pg_vec_pos].buffer +
 471                (frame_offset * rb->frame_size);
 472
 473        if (status != __packet_get_status(po, h.raw))
 474                return NULL;
 475
 476        return h.raw;
 477}
 478
 479static void *packet_current_frame(struct packet_sock *po,
 480                struct packet_ring_buffer *rb,
 481                int status)
 482{
 483        return packet_lookup_frame(po, rb, rb->head, status);
 484}
 485
 486static void prb_del_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 487{
 488        del_timer_sync(&pkc->retire_blk_timer);
 489}
 490
 491static void prb_shutdown_retire_blk_timer(struct packet_sock *po,
 492                int tx_ring,
 493                struct sk_buff_head *rb_queue)
 494{
 495        struct tpacket_kbdq_core *pkc;
 496
 497        pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
 498
 499        spin_lock(&rb_queue->lock);
 500        pkc->delete_blk_timer = 1;
 501        spin_unlock(&rb_queue->lock);
 502
 503        prb_del_retire_blk_timer(pkc);
 504}
 505
 506static void prb_init_blk_timer(struct packet_sock *po,
 507                struct tpacket_kbdq_core *pkc,
 508                void (*func) (unsigned long))
 509{
 510        init_timer(&pkc->retire_blk_timer);
 511        pkc->retire_blk_timer.data = (long)po;
 512        pkc->retire_blk_timer.function = func;
 513        pkc->retire_blk_timer.expires = jiffies;
 514}
 515
 516static void prb_setup_retire_blk_timer(struct packet_sock *po, int tx_ring)
 517{
 518        struct tpacket_kbdq_core *pkc;
 519
 520        if (tx_ring)
 521                BUG();
 522
 523        pkc = tx_ring ? &po->tx_ring.prb_bdqc : &po->rx_ring.prb_bdqc;
 524        prb_init_blk_timer(po, pkc, prb_retire_rx_blk_timer_expired);
 525}
 526
 527static int prb_calc_retire_blk_tmo(struct packet_sock *po,
 528                                int blk_size_in_bytes)
 529{
 530        struct net_device *dev;
 531        unsigned int mbits = 0, msec = 0, div = 0, tmo = 0;
 532        struct ethtool_cmd ecmd;
 533        int err;
 534        u32 speed;
 535
 536        rtnl_lock();
 537        dev = __dev_get_by_index(sock_net(&po->sk), po->ifindex);
 538        if (unlikely(!dev)) {
 539                rtnl_unlock();
 540                return DEFAULT_PRB_RETIRE_TOV;
 541        }
 542        err = __ethtool_get_settings(dev, &ecmd);
 543        speed = ethtool_cmd_speed(&ecmd);
 544        rtnl_unlock();
 545        if (!err) {
 546                /*
 547                 * If the link speed is so slow you don't really
 548                 * need to worry about perf anyways
 549                 */
 550                if (speed < SPEED_1000 || speed == SPEED_UNKNOWN) {
 551                        return DEFAULT_PRB_RETIRE_TOV;
 552                } else {
 553                        msec = 1;
 554                        div = speed / 1000;
 555                }
 556        }
 557
 558        mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
 559
 560        if (div)
 561                mbits /= div;
 562
 563        tmo = mbits * msec;
 564
 565        if (div)
 566                return tmo+1;
 567        return tmo;
 568}
 569
 570static void prb_init_ft_ops(struct tpacket_kbdq_core *p1,
 571                        union tpacket_req_u *req_u)
 572{
 573        p1->feature_req_word = req_u->req3.tp_feature_req_word;
 574}
 575
 576static void init_prb_bdqc(struct packet_sock *po,
 577                        struct packet_ring_buffer *rb,
 578                        struct pgv *pg_vec,
 579                        union tpacket_req_u *req_u, int tx_ring)
 580{
 581        struct tpacket_kbdq_core *p1 = &rb->prb_bdqc;
 582        struct tpacket_block_desc *pbd;
 583
 584        memset(p1, 0x0, sizeof(*p1));
 585
 586        p1->knxt_seq_num = 1;
 587        p1->pkbdq = pg_vec;
 588        pbd = (struct tpacket_block_desc *)pg_vec[0].buffer;
 589        p1->pkblk_start = pg_vec[0].buffer;
 590        p1->kblk_size = req_u->req3.tp_block_size;
 591        p1->knum_blocks = req_u->req3.tp_block_nr;
 592        p1->hdrlen = po->tp_hdrlen;
 593        p1->version = po->tp_version;
 594        p1->last_kactive_blk_num = 0;
 595        po->stats_u.stats3.tp_freeze_q_cnt = 0;
 596        if (req_u->req3.tp_retire_blk_tov)
 597                p1->retire_blk_tov = req_u->req3.tp_retire_blk_tov;
 598        else
 599                p1->retire_blk_tov = prb_calc_retire_blk_tmo(po,
 600                                                req_u->req3.tp_block_size);
 601        p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
 602        p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
 603
 604        prb_init_ft_ops(p1, req_u);
 605        prb_setup_retire_blk_timer(po, tx_ring);
 606        prb_open_block(p1, pbd);
 607}
 608
 609/*  Do NOT update the last_blk_num first.
 610 *  Assumes sk_buff_head lock is held.
 611 */
 612static void _prb_refresh_rx_retire_blk_timer(struct tpacket_kbdq_core *pkc)
 613{
 614        mod_timer(&pkc->retire_blk_timer,
 615                        jiffies + pkc->tov_in_jiffies);
 616        pkc->last_kactive_blk_num = pkc->kactive_blk_num;
 617}
 618
 619/*
 620 * Timer logic:
 621 * 1) We refresh the timer only when we open a block.
 622 *    By doing this we don't waste cycles refreshing the timer
 623 *        on packet-by-packet basis.
 624 *
 625 * With a 1MB block-size, on a 1Gbps line, it will take
 626 * i) ~8 ms to fill a block + ii) memcpy etc.
 627 * In this cut we are not accounting for the memcpy time.
 628 *
 629 * So, if the user sets the 'tmo' to 10ms then the timer
 630 * will never fire while the block is still getting filled
 631 * (which is what we want). However, the user could choose
 632 * to close a block early and that's fine.
 633 *
 634 * But when the timer does fire, we check whether or not to refresh it.
 635 * Since the tmo granularity is in msecs, it is not too expensive
 636 * to refresh the timer, lets say every '8' msecs.
 637 * Either the user can set the 'tmo' or we can derive it based on
 638 * a) line-speed and b) block-size.
 639 * prb_calc_retire_blk_tmo() calculates the tmo.
 640 *
 641 */
 642static void prb_retire_rx_blk_timer_expired(unsigned long data)
 643{
 644        struct packet_sock *po = (struct packet_sock *)data;
 645        struct tpacket_kbdq_core *pkc = &po->rx_ring.prb_bdqc;
 646        unsigned int frozen;
 647        struct tpacket_block_desc *pbd;
 648
 649        spin_lock(&po->sk.sk_receive_queue.lock);
 650
 651        frozen = prb_queue_frozen(pkc);
 652        pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 653
 654        if (unlikely(pkc->delete_blk_timer))
 655                goto out;
 656
 657        /* We only need to plug the race when the block is partially filled.
 658         * tpacket_rcv:
 659         *              lock(); increment BLOCK_NUM_PKTS; unlock()
 660         *              copy_bits() is in progress ...
 661         *              timer fires on other cpu:
 662         *              we can't retire the current block because copy_bits
 663         *              is in progress.
 664         *
 665         */
 666        if (BLOCK_NUM_PKTS(pbd)) {
 667                while (atomic_read(&pkc->blk_fill_in_prog)) {
 668                        /* Waiting for skb_copy_bits to finish... */
 669                        cpu_relax();
 670                }
 671        }
 672
 673        if (pkc->last_kactive_blk_num == pkc->kactive_blk_num) {
 674                if (!frozen) {
 675                        prb_retire_current_block(pkc, po, TP_STATUS_BLK_TMO);
 676                        if (!prb_dispatch_next_block(pkc, po))
 677                                goto refresh_timer;
 678                        else
 679                                goto out;
 680                } else {
 681                        /* Case 1. Queue was frozen because user-space was
 682                         *         lagging behind.
 683                         */
 684                        if (prb_curr_blk_in_use(pkc, pbd)) {
 685                                /*
 686                                 * Ok, user-space is still behind.
 687                                 * So just refresh the timer.
 688                                 */
 689                                goto refresh_timer;
 690                        } else {
 691                               /* Case 2. queue was frozen,user-space caught up,
 692                                * now the link went idle && the timer fired.
 693                                * We don't have a block to close.So we open this
 694                                * block and restart the timer.
 695                                * opening a block thaws the queue,restarts timer
 696                                * Thawing/timer-refresh is a side effect.
 697                                */
 698                                prb_open_block(pkc, pbd);
 699                                goto out;
 700                        }
 701                }
 702        }
 703
 704refresh_timer:
 705        _prb_refresh_rx_retire_blk_timer(pkc);
 706
 707out:
 708        spin_unlock(&po->sk.sk_receive_queue.lock);
 709}
 710
 711static void prb_flush_block(struct tpacket_kbdq_core *pkc1,
 712                struct tpacket_block_desc *pbd1, __u32 status)
 713{
 714        /* Flush everything minus the block header */
 715
 716#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 717        u8 *start, *end;
 718
 719        start = (u8 *)pbd1;
 720
 721        /* Skip the block header(we know header WILL fit in 4K) */
 722        start += PAGE_SIZE;
 723
 724        end = (u8 *)PAGE_ALIGN((unsigned long)pkc1->pkblk_end);
 725        for (; start < end; start += PAGE_SIZE)
 726                flush_dcache_page(pgv_to_page(start));
 727
 728        smp_wmb();
 729#endif
 730
 731        /* Now update the block status. */
 732
 733        BLOCK_STATUS(pbd1) = status;
 734
 735        /* Flush the block header */
 736
 737#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
 738        start = (u8 *)pbd1;
 739        flush_dcache_page(pgv_to_page(start));
 740
 741        smp_wmb();
 742#endif
 743}
 744
 745/*
 746 * Side effect:
 747 *
 748 * 1) flush the block
 749 * 2) Increment active_blk_num
 750 *
 751 * Note:We DONT refresh the timer on purpose.
 752 *      Because almost always the next block will be opened.
 753 */
 754static void prb_close_block(struct tpacket_kbdq_core *pkc1,
 755                struct tpacket_block_desc *pbd1,
 756                struct packet_sock *po, unsigned int stat)
 757{
 758        __u32 status = TP_STATUS_USER | stat;
 759
 760        struct tpacket3_hdr *last_pkt;
 761        struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 762
 763        if (po->stats.tp_drops)
 764                status |= TP_STATUS_LOSING;
 765
 766        last_pkt = (struct tpacket3_hdr *)pkc1->prev;
 767        last_pkt->tp_next_offset = 0;
 768
 769        /* Get the ts of the last pkt */
 770        if (BLOCK_NUM_PKTS(pbd1)) {
 771                h1->ts_last_pkt.ts_sec = last_pkt->tp_sec;
 772                h1->ts_last_pkt.ts_nsec = last_pkt->tp_nsec;
 773        } else {
 774                /* Ok, we tmo'd - so get the current time */
 775                struct timespec ts;
 776                getnstimeofday(&ts);
 777                h1->ts_last_pkt.ts_sec = ts.tv_sec;
 778                h1->ts_last_pkt.ts_nsec = ts.tv_nsec;
 779        }
 780
 781        smp_wmb();
 782
 783        /* Flush the block */
 784        prb_flush_block(pkc1, pbd1, status);
 785
 786        pkc1->kactive_blk_num = GET_NEXT_PRB_BLK_NUM(pkc1);
 787}
 788
 789static void prb_thaw_queue(struct tpacket_kbdq_core *pkc)
 790{
 791        pkc->reset_pending_on_curr_blk = 0;
 792}
 793
 794/*
 795 * Side effect of opening a block:
 796 *
 797 * 1) prb_queue is thawed.
 798 * 2) retire_blk_timer is refreshed.
 799 *
 800 */
 801static void prb_open_block(struct tpacket_kbdq_core *pkc1,
 802        struct tpacket_block_desc *pbd1)
 803{
 804        struct timespec ts;
 805        struct tpacket_hdr_v1 *h1 = &pbd1->hdr.bh1;
 806
 807        smp_rmb();
 808
 809        if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd1))) {
 810
 811                /* We could have just memset this but we will lose the
 812                 * flexibility of making the priv area sticky
 813                 */
 814                BLOCK_SNUM(pbd1) = pkc1->knxt_seq_num++;
 815                BLOCK_NUM_PKTS(pbd1) = 0;
 816                BLOCK_LEN(pbd1) = BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 817                getnstimeofday(&ts);
 818                h1->ts_first_pkt.ts_sec = ts.tv_sec;
 819                h1->ts_first_pkt.ts_nsec = ts.tv_nsec;
 820                pkc1->pkblk_start = (char *)pbd1;
 821                pkc1->nxt_offset = pkc1->pkblk_start + BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 822                BLOCK_O2FP(pbd1) = (__u32)BLK_PLUS_PRIV(pkc1->blk_sizeof_priv);
 823                BLOCK_O2PRIV(pbd1) = BLK_HDR_LEN;
 824                pbd1->version = pkc1->version;
 825                pkc1->prev = pkc1->nxt_offset;
 826                pkc1->pkblk_end = pkc1->pkblk_start + pkc1->kblk_size;
 827                prb_thaw_queue(pkc1);
 828                _prb_refresh_rx_retire_blk_timer(pkc1);
 829
 830                smp_wmb();
 831
 832                return;
 833        }
 834
 835        WARN(1, "ERROR block:%p is NOT FREE status:%d kactive_blk_num:%d\n",
 836                pbd1, BLOCK_STATUS(pbd1), pkc1->kactive_blk_num);
 837        dump_stack();
 838        BUG();
 839}
 840
 841/*
 842 * Queue freeze logic:
 843 * 1) Assume tp_block_nr = 8 blocks.
 844 * 2) At time 't0', user opens Rx ring.
 845 * 3) Some time past 't0', kernel starts filling blocks starting from 0 .. 7
 846 * 4) user-space is either sleeping or processing block '0'.
 847 * 5) tpacket_rcv is currently filling block '7', since there is no space left,
 848 *    it will close block-7,loop around and try to fill block '0'.
 849 *    call-flow:
 850 *    __packet_lookup_frame_in_block
 851 *      prb_retire_current_block()
 852 *      prb_dispatch_next_block()
 853 *        |->(BLOCK_STATUS == USER) evaluates to true
 854 *    5.1) Since block-0 is currently in-use, we just freeze the queue.
 855 * 6) Now there are two cases:
 856 *    6.1) Link goes idle right after the queue is frozen.
 857 *         But remember, the last open_block() refreshed the timer.
 858 *         When this timer expires,it will refresh itself so that we can
 859 *         re-open block-0 in near future.
 860 *    6.2) Link is busy and keeps on receiving packets. This is a simple
 861 *         case and __packet_lookup_frame_in_block will check if block-0
 862 *         is free and can now be re-used.
 863 */
 864static void prb_freeze_queue(struct tpacket_kbdq_core *pkc,
 865                                  struct packet_sock *po)
 866{
 867        pkc->reset_pending_on_curr_blk = 1;
 868        po->stats_u.stats3.tp_freeze_q_cnt++;
 869}
 870
 871#define TOTAL_PKT_LEN_INCL_ALIGN(length) (ALIGN((length), V3_ALIGNMENT))
 872
 873/*
 874 * If the next block is free then we will dispatch it
 875 * and return a good offset.
 876 * Else, we will freeze the queue.
 877 * So, caller must check the return value.
 878 */
 879static void *prb_dispatch_next_block(struct tpacket_kbdq_core *pkc,
 880                struct packet_sock *po)
 881{
 882        struct tpacket_block_desc *pbd;
 883
 884        smp_rmb();
 885
 886        /* 1. Get current block num */
 887        pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 888
 889        /* 2. If this block is currently in_use then freeze the queue */
 890        if (TP_STATUS_USER & BLOCK_STATUS(pbd)) {
 891                prb_freeze_queue(pkc, po);
 892                return NULL;
 893        }
 894
 895        /*
 896         * 3.
 897         * open this block and return the offset where the first packet
 898         * needs to get stored.
 899         */
 900        prb_open_block(pkc, pbd);
 901        return (void *)pkc->nxt_offset;
 902}
 903
 904static void prb_retire_current_block(struct tpacket_kbdq_core *pkc,
 905                struct packet_sock *po, unsigned int status)
 906{
 907        struct tpacket_block_desc *pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
 908
 909        /* retire/close the current block */
 910        if (likely(TP_STATUS_KERNEL == BLOCK_STATUS(pbd))) {
 911                /*
 912                 * Plug the case where copy_bits() is in progress on
 913                 * cpu-0 and tpacket_rcv() got invoked on cpu-1, didn't
 914                 * have space to copy the pkt in the current block and
 915                 * called prb_retire_current_block()
 916                 *
 917                 * We don't need to worry about the TMO case because
 918                 * the timer-handler already handled this case.
 919                 */
 920                if (!(status & TP_STATUS_BLK_TMO)) {
 921                        while (atomic_read(&pkc->blk_fill_in_prog)) {
 922                                /* Waiting for skb_copy_bits to finish... */
 923                                cpu_relax();
 924                        }
 925                }
 926                prb_close_block(pkc, pbd, po, status);
 927                return;
 928        }
 929
 930        WARN(1, "ERROR-pbd[%d]:%p\n", pkc->kactive_blk_num, pbd);
 931        dump_stack();
 932        BUG();
 933}
 934
 935static int prb_curr_blk_in_use(struct tpacket_kbdq_core *pkc,
 936                                      struct tpacket_block_desc *pbd)
 937{
 938        return TP_STATUS_USER & BLOCK_STATUS(pbd);
 939}
 940
 941static int prb_queue_frozen(struct tpacket_kbdq_core *pkc)
 942{
 943        return pkc->reset_pending_on_curr_blk;
 944}
 945
 946static void prb_clear_blk_fill_status(struct packet_ring_buffer *rb)
 947{
 948        struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
 949        atomic_dec(&pkc->blk_fill_in_prog);
 950}
 951
 952static void prb_fill_rxhash(struct tpacket_kbdq_core *pkc,
 953                        struct tpacket3_hdr *ppd)
 954{
 955        ppd->hv1.tp_rxhash = skb_get_rxhash(pkc->skb);
 956}
 957
 958static void prb_clear_rxhash(struct tpacket_kbdq_core *pkc,
 959                        struct tpacket3_hdr *ppd)
 960{
 961        ppd->hv1.tp_rxhash = 0;
 962}
 963
 964static void prb_fill_vlan_info(struct tpacket_kbdq_core *pkc,
 965                        struct tpacket3_hdr *ppd)
 966{
 967        if (vlan_tx_tag_present(pkc->skb)) {
 968                ppd->hv1.tp_vlan_tci = vlan_tx_tag_get(pkc->skb);
 969                ppd->tp_status = TP_STATUS_VLAN_VALID;
 970        } else {
 971                ppd->hv1.tp_vlan_tci = ppd->tp_status = 0;
 972        }
 973}
 974
 975static void prb_run_all_ft_ops(struct tpacket_kbdq_core *pkc,
 976                        struct tpacket3_hdr *ppd)
 977{
 978        prb_fill_vlan_info(pkc, ppd);
 979
 980        if (pkc->feature_req_word & TP_FT_REQ_FILL_RXHASH)
 981                prb_fill_rxhash(pkc, ppd);
 982        else
 983                prb_clear_rxhash(pkc, ppd);
 984}
 985
 986static void prb_fill_curr_block(char *curr,
 987                                struct tpacket_kbdq_core *pkc,
 988                                struct tpacket_block_desc *pbd,
 989                                unsigned int len)
 990{
 991        struct tpacket3_hdr *ppd;
 992
 993        ppd  = (struct tpacket3_hdr *)curr;
 994        ppd->tp_next_offset = TOTAL_PKT_LEN_INCL_ALIGN(len);
 995        pkc->prev = curr;
 996        pkc->nxt_offset += TOTAL_PKT_LEN_INCL_ALIGN(len);
 997        BLOCK_LEN(pbd) += TOTAL_PKT_LEN_INCL_ALIGN(len);
 998        BLOCK_NUM_PKTS(pbd) += 1;
 999        atomic_inc(&pkc->blk_fill_in_prog);
1000        prb_run_all_ft_ops(pkc, ppd);
1001}
1002
1003/* Assumes caller has the sk->rx_queue.lock */
1004static void *__packet_lookup_frame_in_block(struct packet_sock *po,
1005                                            struct sk_buff *skb,
1006                                                int status,
1007                                            unsigned int len
1008                                            )
1009{
1010        struct tpacket_kbdq_core *pkc;
1011        struct tpacket_block_desc *pbd;
1012        char *curr, *end;
1013
1014        pkc = GET_PBDQC_FROM_RB(&po->rx_ring);
1015        pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1016
1017        /* Queue is frozen when user space is lagging behind */
1018        if (prb_queue_frozen(pkc)) {
1019                /*
1020                 * Check if that last block which caused the queue to freeze,
1021                 * is still in_use by user-space.
1022                 */
1023                if (prb_curr_blk_in_use(pkc, pbd)) {
1024                        /* Can't record this packet */
1025                        return NULL;
1026                } else {
1027                        /*
1028                         * Ok, the block was released by user-space.
1029                         * Now let's open that block.
1030                         * opening a block also thaws the queue.
1031                         * Thawing is a side effect.
1032                         */
1033                        prb_open_block(pkc, pbd);
1034                }
1035        }
1036
1037        smp_mb();
1038        curr = pkc->nxt_offset;
1039        pkc->skb = skb;
1040        end = (char *)pbd + pkc->kblk_size;
1041
1042        /* first try the current block */
1043        if (curr+TOTAL_PKT_LEN_INCL_ALIGN(len) < end) {
1044                prb_fill_curr_block(curr, pkc, pbd, len);
1045                return (void *)curr;
1046        }
1047
1048        /* Ok, close the current block */
1049        prb_retire_current_block(pkc, po, 0);
1050
1051        /* Now, try to dispatch the next block */
1052        curr = (char *)prb_dispatch_next_block(pkc, po);
1053        if (curr) {
1054                pbd = GET_CURR_PBLOCK_DESC_FROM_CORE(pkc);
1055                prb_fill_curr_block(curr, pkc, pbd, len);
1056                return (void *)curr;
1057        }
1058
1059        /*
1060         * No free blocks are available.user_space hasn't caught up yet.
1061         * Queue was just frozen and now this packet will get dropped.
1062         */
1063        return NULL;
1064}
1065
1066static void *packet_current_rx_frame(struct packet_sock *po,
1067                                            struct sk_buff *skb,
1068                                            int status, unsigned int len)
1069{
1070        char *curr = NULL;
1071        switch (po->tp_version) {
1072        case TPACKET_V1:
1073        case TPACKET_V2:
1074                curr = packet_lookup_frame(po, &po->rx_ring,
1075                                        po->rx_ring.head, status);
1076                return curr;
1077        case TPACKET_V3:
1078                return __packet_lookup_frame_in_block(po, skb, status, len);
1079        default:
1080                WARN(1, "TPACKET version not supported\n");
1081                BUG();
1082                return NULL;
1083        }
1084}
1085
1086static void *prb_lookup_block(struct packet_sock *po,
1087                                     struct packet_ring_buffer *rb,
1088                                     unsigned int previous,
1089                                     int status)
1090{
1091        struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
1092        struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous);
1093
1094        if (status != BLOCK_STATUS(pbd))
1095                return NULL;
1096        return pbd;
1097}
1098
1099static int prb_previous_blk_num(struct packet_ring_buffer *rb)
1100{
1101        unsigned int prev;
1102        if (rb->prb_bdqc.kactive_blk_num)
1103                prev = rb->prb_bdqc.kactive_blk_num-1;
1104        else
1105                prev = rb->prb_bdqc.knum_blocks-1;
1106        return prev;
1107}
1108
1109/* Assumes caller has held the rx_queue.lock */
1110static void *__prb_previous_block(struct packet_sock *po,
1111                                         struct packet_ring_buffer *rb,
1112                                         int status)
1113{
1114        unsigned int previous = prb_previous_blk_num(rb);
1115        return prb_lookup_block(po, rb, previous, status);
1116}
1117
1118static void *packet_previous_rx_frame(struct packet_sock *po,
1119                                             struct packet_ring_buffer *rb,
1120                                             int status)
1121{
1122        if (po->tp_version <= TPACKET_V2)
1123                return packet_previous_frame(po, rb, status);
1124
1125        return __prb_previous_block(po, rb, status);
1126}
1127
1128static void packet_increment_rx_head(struct packet_sock *po,
1129                                            struct packet_ring_buffer *rb)
1130{
1131        switch (po->tp_version) {
1132        case TPACKET_V1:
1133        case TPACKET_V2:
1134                return packet_increment_head(rb);
1135        case TPACKET_V3:
1136        default:
1137                WARN(1, "TPACKET version not supported.\n");
1138                BUG();
1139                return;
1140        }
1141}
1142
1143static void *packet_previous_frame(struct packet_sock *po,
1144                struct packet_ring_buffer *rb,
1145                int status)
1146{
1147        unsigned int previous = rb->head ? rb->head - 1 : rb->frame_max;
1148        return packet_lookup_frame(po, rb, previous, status);
1149}
1150
1151static void packet_increment_head(struct packet_ring_buffer *buff)
1152{
1153        buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
1154}
1155
1156static void packet_sock_destruct(struct sock *sk)
1157{
1158        skb_queue_purge(&sk->sk_error_queue);
1159
1160        WARN_ON(atomic_read(&sk->sk_rmem_alloc));
1161        WARN_ON(atomic_read(&sk->sk_wmem_alloc));
1162
1163        if (!sock_flag(sk, SOCK_DEAD)) {
1164                pr_err("Attempt to release alive packet socket: %p\n", sk);
1165                return;
1166        }
1167
1168        sk_refcnt_debug_dec(sk);
1169}
1170
1171static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
1172{
1173        int x = atomic_read(&f->rr_cur) + 1;
1174
1175        if (x >= num)
1176                x = 0;
1177
1178        return x;
1179}
1180
1181static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1182{
1183        u32 idx, hash = skb->rxhash;
1184
1185        idx = ((u64)hash * num) >> 32;
1186
1187        return f->arr[idx];
1188}
1189
1190static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1191{
1192        int cur, old;
1193
1194        cur = atomic_read(&f->rr_cur);
1195        while ((old = atomic_cmpxchg(&f->rr_cur, cur,
1196                                     fanout_rr_next(f, num))) != cur)
1197                cur = old;
1198        return f->arr[cur];
1199}
1200
1201static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
1202{
1203        unsigned int cpu = smp_processor_id();
1204
1205        return f->arr[cpu % num];
1206}
1207
1208static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
1209                             struct packet_type *pt, struct net_device *orig_dev)
1210{
1211        struct packet_fanout *f = pt->af_packet_priv;
1212        unsigned int num = f->num_members;
1213        struct packet_sock *po;
1214        struct sock *sk;
1215
1216        if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
1217            !num) {
1218                kfree_skb(skb);
1219                return 0;
1220        }
1221
1222        switch (f->type) {
1223        case PACKET_FANOUT_HASH:
1224        default:
1225                if (f->defrag) {
1226                        skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
1227                        if (!skb)
1228                                return 0;
1229                }
1230                skb_get_rxhash(skb);
1231                sk = fanout_demux_hash(f, skb, num);
1232                break;
1233        case PACKET_FANOUT_LB:
1234                sk = fanout_demux_lb(f, skb, num);
1235                break;
1236        case PACKET_FANOUT_CPU:
1237                sk = fanout_demux_cpu(f, skb, num);
1238                break;
1239        }
1240
1241        po = pkt_sk(sk);
1242
1243        return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
1244}
1245
1246static DEFINE_MUTEX(fanout_mutex);
1247static LIST_HEAD(fanout_list);
1248
1249static void __fanout_link(struct sock *sk, struct packet_sock *po)
1250{
1251        struct packet_fanout *f = po->fanout;
1252
1253        spin_lock(&f->lock);
1254        f->arr[f->num_members] = sk;
1255        smp_wmb();
1256        f->num_members++;
1257        spin_unlock(&f->lock);
1258}
1259
1260static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
1261{
1262        struct packet_fanout *f = po->fanout;
1263        int i;
1264
1265        spin_lock(&f->lock);
1266        for (i = 0; i < f->num_members; i++) {
1267                if (f->arr[i] == sk)
1268                        break;
1269        }
1270        BUG_ON(i >= f->num_members);
1271        f->arr[i] = f->arr[f->num_members - 1];
1272        f->num_members--;
1273        spin_unlock(&f->lock);
1274}
1275
1276static bool match_fanout_group(struct packet_type *ptype, struct sock * sk)
1277{
1278        if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout)
1279                return true;
1280
1281        return false;
1282}
1283
1284static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
1285{
1286        struct packet_sock *po = pkt_sk(sk);
1287        struct packet_fanout *f, *match;
1288        u8 type = type_flags & 0xff;
1289        u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0;
1290        int err;
1291
1292        switch (type) {
1293        case PACKET_FANOUT_HASH:
1294        case PACKET_FANOUT_LB:
1295        case PACKET_FANOUT_CPU:
1296                break;
1297        default:
1298                return -EINVAL;
1299        }
1300
1301        if (!po->running)
1302                return -EINVAL;
1303
1304        if (po->fanout)
1305                return -EALREADY;
1306
1307        mutex_lock(&fanout_mutex);
1308        match = NULL;
1309        list_for_each_entry(f, &fanout_list, list) {
1310                if (f->id == id &&
1311                    read_pnet(&f->net) == sock_net(sk)) {
1312                        match = f;
1313                        break;
1314                }
1315        }
1316        err = -EINVAL;
1317        if (match && match->defrag != defrag)
1318                goto out;
1319        if (!match) {
1320                err = -ENOMEM;
1321                match = kzalloc(sizeof(*match), GFP_KERNEL);
1322                if (!match)
1323                        goto out;
1324                write_pnet(&match->net, sock_net(sk));
1325                match->id = id;
1326                match->type = type;
1327                match->defrag = defrag;
1328                atomic_set(&match->rr_cur, 0);
1329                INIT_LIST_HEAD(&match->list);
1330                spin_lock_init(&match->lock);
1331                atomic_set(&match->sk_ref, 0);
1332                match->prot_hook.type = po->prot_hook.type;
1333                match->prot_hook.dev = po->prot_hook.dev;
1334                match->prot_hook.func = packet_rcv_fanout;
1335                match->prot_hook.af_packet_priv = match;
1336                match->prot_hook.id_match = match_fanout_group;
1337                dev_add_pack(&match->prot_hook);
1338                list_add(&match->list, &fanout_list);
1339        }
1340        err = -EINVAL;
1341        if (match->type == type &&
1342            match->prot_hook.type == po->prot_hook.type &&
1343            match->prot_hook.dev == po->prot_hook.dev) {
1344                err = -ENOSPC;
1345                if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
1346                        __dev_remove_pack(&po->prot_hook);
1347                        po->fanout = match;
1348                        atomic_inc(&match->sk_ref);
1349                        __fanout_link(sk, po);
1350                        err = 0;
1351                }
1352        }
1353out:
1354        mutex_unlock(&fanout_mutex);
1355        return err;
1356}
1357
1358static void fanout_release(struct sock *sk)
1359{
1360        struct packet_sock *po = pkt_sk(sk);
1361        struct packet_fanout *f;
1362
1363        f = po->fanout;
1364        if (!f)
1365                return;
1366
1367        po->fanout = NULL;
1368
1369        mutex_lock(&fanout_mutex);
1370        if (atomic_dec_and_test(&f->sk_ref)) {
1371                list_del(&f->list);
1372                dev_remove_pack(&f->prot_hook);
1373                kfree(f);
1374        }
1375        mutex_unlock(&fanout_mutex);
1376}
1377
1378static const struct proto_ops packet_ops;
1379
1380static const struct proto_ops packet_ops_spkt;
1381
1382static int packet_rcv_spkt(struct sk_buff *skb, struct net_device *dev,
1383                           struct packet_type *pt, struct net_device *orig_dev)
1384{
1385        struct sock *sk;
1386        struct sockaddr_pkt *spkt;
1387
1388        /*
1389         *      When we registered the protocol we saved the socket in the data
1390         *      field for just this event.
1391         */
1392
1393        sk = pt->af_packet_priv;
1394
1395        /*
1396         *      Yank back the headers [hope the device set this
1397         *      right or kerboom...]
1398         *
1399         *      Incoming packets have ll header pulled,
1400         *      push it back.
1401         *
1402         *      For outgoing ones skb->data == skb_mac_header(skb)
1403         *      so that this procedure is noop.
1404         */
1405
1406        if (skb->pkt_type == PACKET_LOOPBACK)
1407                goto out;
1408
1409        if (!net_eq(dev_net(dev), sock_net(sk)))
1410                goto out;
1411
1412        skb = skb_share_check(skb, GFP_ATOMIC);
1413        if (skb == NULL)
1414                goto oom;
1415
1416        /* drop any routing info */
1417        skb_dst_drop(skb);
1418
1419        /* drop conntrack reference */
1420        nf_reset(skb);
1421
1422        spkt = &PACKET_SKB_CB(skb)->sa.pkt;
1423
1424        skb_push(skb, skb->data - skb_mac_header(skb));
1425
1426        /*
1427         *      The SOCK_PACKET socket receives _all_ frames.
1428         */
1429
1430        spkt->spkt_family = dev->type;
1431        strlcpy(spkt->spkt_device, dev->name, sizeof(spkt->spkt_device));
1432        spkt->spkt_protocol = skb->protocol;
1433
1434        /*
1435         *      Charge the memory to the socket. This is done specifically
1436         *      to prevent sockets using all the memory up.
1437         */
1438
1439        if (sock_queue_rcv_skb(sk, skb) == 0)
1440                return 0;
1441
1442out:
1443        kfree_skb(skb);
1444oom:
1445        return 0;
1446}
1447
1448
1449/*
1450 *      Output a raw packet to a device layer. This bypasses all the other
1451 *      protocol layers and you must therefore supply it with a complete frame
1452 */
1453
1454static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
1455                               struct msghdr *msg, size_t len)
1456{
1457        struct sock *sk = sock->sk;
1458        struct sockaddr_pkt *saddr = (struct sockaddr_pkt *)msg->msg_name;
1459        struct sk_buff *skb = NULL;
1460        struct net_device *dev;
1461        __be16 proto = 0;
1462        int err;
1463        int extra_len = 0;
1464
1465        /*
1466         *      Get and verify the address.
1467         */
1468
1469        if (saddr) {
1470                if (msg->msg_namelen < sizeof(struct sockaddr))
1471                        return -EINVAL;
1472                if (msg->msg_namelen == sizeof(struct sockaddr_pkt))
1473                        proto = saddr->spkt_protocol;
1474        } else
1475                return -ENOTCONN;       /* SOCK_PACKET must be sent giving an address */
1476
1477        /*
1478         *      Find the device first to size check it
1479         */
1480
1481        saddr->spkt_device[sizeof(saddr->spkt_device) - 1] = 0;
1482retry:
1483        rcu_read_lock();
1484        dev = dev_get_by_name_rcu(sock_net(sk), saddr->spkt_device);
1485        err = -ENODEV;
1486        if (dev == NULL)
1487                goto out_unlock;
1488
1489        err = -ENETDOWN;
1490        if (!(dev->flags & IFF_UP))
1491                goto out_unlock;
1492
1493        /*
1494         * You may not queue a frame bigger than the mtu. This is the lowest level
1495         * raw protocol and you must do your own fragmentation at this level.
1496         */
1497
1498        if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
1499                if (!netif_supports_nofcs(dev)) {
1500                        err = -EPROTONOSUPPORT;
1501                        goto out_unlock;
1502                }
1503                extra_len = 4; /* We're doing our own CRC */
1504        }
1505
1506        err = -EMSGSIZE;
1507        if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
1508                goto out_unlock;
1509
1510        if (!skb) {
1511                size_t reserved = LL_RESERVED_SPACE(dev);
1512                int tlen = dev->needed_tailroom;
1513                unsigned int hhlen = dev->header_ops ? dev->hard_header_len : 0;
1514
1515                rcu_read_unlock();
1516                skb = sock_wmalloc(sk, len + reserved + tlen, 0, GFP_KERNEL);
1517                if (skb == NULL)
1518                        return -ENOBUFS;
1519                /* FIXME: Save some space for broken drivers that write a hard
1520                 * header at transmission time by themselves. PPP is the notable
1521                 * one here. This should really be fixed at the driver level.
1522                 */
1523                skb_reserve(skb, reserved);
1524                skb_reset_network_header(skb);
1525
1526                /* Try to align data part correctly */
1527                if (hhlen) {
1528                        skb->data -= hhlen;
1529                        skb->tail -= hhlen;
1530                        if (len < hhlen)
1531                                skb_reset_network_header(skb);
1532                }
1533                err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1534                if (err)
1535                        goto out_free;
1536                goto retry;
1537        }
1538
1539        if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
1540                /* Earlier code assumed this would be a VLAN pkt,
1541                 * double-check this now that we have the actual
1542                 * packet in hand.
1543                 */
1544                struct ethhdr *ehdr;
1545                skb_reset_mac_header(skb);
1546                ehdr = eth_hdr(skb);
1547                if (ehdr->h_proto != htons(ETH_P_8021Q)) {
1548                        err = -EMSGSIZE;
1549                        goto out_unlock;
1550                }
1551        }
1552
1553        skb->protocol = proto;
1554        skb->dev = dev;
1555        skb->priority = sk->sk_priority;
1556        skb->mark = sk->sk_mark;
1557        err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
1558        if (err < 0)
1559                goto out_unlock;
1560
1561        if (unlikely(extra_len == 4))
1562                skb->no_fcs = 1;
1563
1564        dev_queue_xmit(skb);
1565        rcu_read_unlock();
1566        return len;
1567
1568out_unlock:
1569        rcu_read_unlock();
1570out_free:
1571        kfree_skb(skb);
1572        return err;
1573}
1574
1575static unsigned int run_filter(const struct sk_buff *skb,
1576                                      const struct sock *sk,
1577                                      unsigned int res)
1578{
1579        struct sk_filter *filter;
1580
1581        rcu_read_lock();
1582        filter = rcu_dereference(sk->sk_filter);
1583        if (filter != NULL)
1584                res = SK_RUN_FILTER(filter, skb);
1585        rcu_read_unlock();
1586
1587        return res;
1588}
1589
1590/*
1591 * This function makes lazy skb cloning in hope that most of packets
1592 * are discarded by BPF.
1593 *
1594 * Note tricky part: we DO mangle shared skb! skb->data, skb->len
1595 * and skb->cb are mangled. It works because (and until) packets
1596 * falling here are owned by current CPU. Output packets are cloned
1597 * by dev_queue_xmit_nit(), input packets are processed by net_bh
1598 * sequencially, so that if we return skb to original state on exit,
1599 * we will not harm anyone.
1600 */
1601
1602static int packet_rcv(struct sk_buff *skb, struct net_device *dev,
1603                      struct packet_type *pt, struct net_device *orig_dev)
1604{
1605        struct sock *sk;
1606        struct sockaddr_ll *sll;
1607        struct packet_sock *po;
1608        u8 *skb_head = skb->data;
1609        int skb_len = skb->len;
1610        unsigned int snaplen, res;
1611
1612        if (skb->pkt_type == PACKET_LOOPBACK)
1613                goto drop;
1614
1615        sk = pt->af_packet_priv;
1616        po = pkt_sk(sk);
1617
1618        if (!net_eq(dev_net(dev), sock_net(sk)))
1619                goto drop;
1620
1621        skb->dev = dev;
1622
1623        if (dev->header_ops) {
1624                /* The device has an explicit notion of ll header,
1625                 * exported to higher levels.
1626                 *
1627                 * Otherwise, the device hides details of its frame
1628                 * structure, so that corresponding packet head is
1629                 * never delivered to user.
1630                 */
1631                if (sk->sk_type != SOCK_DGRAM)
1632                        skb_push(skb, skb->data - skb_mac_header(skb));
1633                else if (skb->pkt_type == PACKET_OUTGOING) {
1634                        /* Special case: outgoing packets have ll header at head */
1635                        skb_pull(skb, skb_network_offset(skb));
1636                }
1637        }
1638
1639        snaplen = skb->len;
1640
1641        res = run_filter(skb, sk, snaplen);
1642        if (!res)
1643                goto drop_n_restore;
1644        if (snaplen > res)
1645                snaplen = res;
1646
1647        if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
1648                goto drop_n_acct;
1649
1650        if (skb_shared(skb)) {
1651                struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
1652                if (nskb == NULL)
1653                        goto drop_n_acct;
1654
1655                if (skb_head != skb->data) {
1656                        skb->data = skb_head;
1657                        skb->len = skb_len;
1658                }
1659                consume_skb(skb);
1660                skb = nskb;
1661        }
1662
1663        BUILD_BUG_ON(sizeof(*PACKET_SKB_CB(skb)) + MAX_ADDR_LEN - 8 >
1664                     sizeof(skb->cb));
1665
1666        sll = &PACKET_SKB_CB(skb)->sa.ll;
1667        sll->sll_family = AF_PACKET;
1668        sll->sll_hatype = dev->type;
1669        sll->sll_protocol = skb->protocol;
1670        sll->sll_pkttype = skb->pkt_type;
1671        if (unlikely(po->origdev))
1672                sll->sll_ifindex = orig_dev->ifindex;
1673        else
1674                sll->sll_ifindex = dev->ifindex;
1675
1676        sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1677
1678        PACKET_SKB_CB(skb)->origlen = skb->len;
1679
1680        if (pskb_trim(skb, snaplen))
1681                goto drop_n_acct;
1682
1683        skb_set_owner_r(skb, sk);
1684        skb->dev = NULL;
1685        skb_dst_drop(skb);
1686
1687        /* drop conntrack reference */
1688        nf_reset(skb);
1689
1690        spin_lock(&sk->sk_receive_queue.lock);
1691        po->stats.tp_packets++;
1692        skb->dropcount = atomic_read(&sk->sk_drops);
1693        __skb_queue_tail(&sk->sk_receive_queue, skb);
1694        spin_unlock(&sk->sk_receive_queue.lock);
1695        sk->sk_data_ready(sk, skb->len);
1696        return 0;
1697
1698drop_n_acct:
1699        spin_lock(&sk->sk_receive_queue.lock);
1700        po->stats.tp_drops++;
1701        atomic_inc(&sk->sk_drops);
1702        spin_unlock(&sk->sk_receive_queue.lock);
1703
1704drop_n_restore:
1705        if (skb_head != skb->data && skb_shared(skb)) {
1706                skb->data = skb_head;
1707                skb->len = skb_len;
1708        }
1709drop:
1710        consume_skb(skb);
1711        return 0;
1712}
1713
1714static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
1715                       struct packet_type *pt, struct net_device *orig_dev)
1716{
1717        struct sock *sk;
1718        struct packet_sock *po;
1719        struct sockaddr_ll *sll;
1720        union {
1721                struct tpacket_hdr *h1;
1722                struct tpacket2_hdr *h2;
1723                struct tpacket3_hdr *h3;
1724                void *raw;
1725        } h;
1726        u8 *skb_head = skb->data;
1727        int skb_len = skb->len;
1728        unsigned int snaplen, res;
1729        unsigned long status = TP_STATUS_USER;
1730        unsigned short macoff, netoff, hdrlen;
1731        struct sk_buff *copy_skb = NULL;
1732        struct timeval tv;
1733        struct timespec ts;
1734        struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
1735
1736        if (skb->pkt_type == PACKET_LOOPBACK)
1737                goto drop;
1738
1739        sk = pt->af_packet_priv;
1740        po = pkt_sk(sk);
1741
1742        if (!net_eq(dev_net(dev), sock_net(sk)))
1743                goto drop;
1744
1745        if (dev->header_ops) {
1746                if (sk->sk_type != SOCK_DGRAM)
1747                        skb_push(skb, skb->data - skb_mac_header(skb));
1748                else if (skb->pkt_type == PACKET_OUTGOING) {
1749                        /* Special case: outgoing packets have ll header at head */
1750                        skb_pull(skb, skb_network_offset(skb));
1751                }
1752        }
1753
1754        if (skb->ip_summed == CHECKSUM_PARTIAL)
1755                status |= TP_STATUS_CSUMNOTREADY;
1756
1757        snaplen = skb->len;
1758
1759        res = run_filter(skb, sk, snaplen);
1760        if (!res)
1761                goto drop_n_restore;
1762        if (snaplen > res)
1763                snaplen = res;
1764
1765        if (sk->sk_type == SOCK_DGRAM) {
1766                macoff = netoff = TPACKET_ALIGN(po->tp_hdrlen) + 16 +
1767                                  po->tp_reserve;
1768        } else {
1769                unsigned int maclen = skb_network_offset(skb);
1770                netoff = TPACKET_ALIGN(po->tp_hdrlen +
1771                                       (maclen < 16 ? 16 : maclen)) +
1772                        po->tp_reserve;
1773                macoff = netoff - maclen;
1774        }
1775        if (po->tp_version <= TPACKET_V2) {
1776                if (macoff + snaplen > po->rx_ring.frame_size) {
1777                        if (po->copy_thresh &&
1778                            atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1779                                if (skb_shared(skb)) {
1780                                        copy_skb = skb_clone(skb, GFP_ATOMIC);
1781                                } else {
1782                                        copy_skb = skb_get(skb);
1783                                        skb_head = skb->data;
1784                                }
1785                                if (copy_skb)
1786                                        skb_set_owner_r(copy_skb, sk);
1787                        }
1788                        snaplen = po->rx_ring.frame_size - macoff;
1789                        if ((int)snaplen < 0)
1790                                snaplen = 0;
1791                }
1792        }
1793        spin_lock(&sk->sk_receive_queue.lock);
1794        h.raw = packet_current_rx_frame(po, skb,
1795                                        TP_STATUS_KERNEL, (macoff+snaplen));
1796        if (!h.raw)
1797                goto ring_is_full;
1798        if (po->tp_version <= TPACKET_V2) {
1799                packet_increment_rx_head(po, &po->rx_ring);
1800        /*
1801         * LOSING will be reported till you read the stats,
1802         * because it's COR - Clear On Read.
1803         * Anyways, moving it for V1/V2 only as V3 doesn't need this
1804         * at packet level.
1805         */
1806                if (po->stats.tp_drops)
1807                        status |= TP_STATUS_LOSING;
1808        }
1809        po->stats.tp_packets++;
1810        if (copy_skb) {
1811                status |= TP_STATUS_COPY;
1812                __skb_queue_tail(&sk->sk_receive_queue, copy_skb);
1813        }
1814        spin_unlock(&sk->sk_receive_queue.lock);
1815
1816        skb_copy_bits(skb, 0, h.raw + macoff, snaplen);
1817
1818        switch (po->tp_version) {
1819        case TPACKET_V1:
1820                h.h1->tp_len = skb->len;
1821                h.h1->tp_snaplen = snaplen;
1822                h.h1->tp_mac = macoff;
1823                h.h1->tp_net = netoff;
1824                if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1825                                && shhwtstamps->syststamp.tv64)
1826                        tv = ktime_to_timeval(shhwtstamps->syststamp);
1827                else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1828                                && shhwtstamps->hwtstamp.tv64)
1829                        tv = ktime_to_timeval(shhwtstamps->hwtstamp);
1830                else if (skb->tstamp.tv64)
1831                        tv = ktime_to_timeval(skb->tstamp);
1832                else
1833                        do_gettimeofday(&tv);
1834                h.h1->tp_sec = tv.tv_sec;
1835                h.h1->tp_usec = tv.tv_usec;
1836                hdrlen = sizeof(*h.h1);
1837                break;
1838        case TPACKET_V2:
1839                h.h2->tp_len = skb->len;
1840                h.h2->tp_snaplen = snaplen;
1841                h.h2->tp_mac = macoff;
1842                h.h2->tp_net = netoff;
1843                if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1844                                && shhwtstamps->syststamp.tv64)
1845                        ts = ktime_to_timespec(shhwtstamps->syststamp);
1846                else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1847                                && shhwtstamps->hwtstamp.tv64)
1848                        ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1849                else if (skb->tstamp.tv64)
1850                        ts = ktime_to_timespec(skb->tstamp);
1851                else
1852                        getnstimeofday(&ts);
1853                h.h2->tp_sec = ts.tv_sec;
1854                h.h2->tp_nsec = ts.tv_nsec;
1855                if (vlan_tx_tag_present(skb)) {
1856                        h.h2->tp_vlan_tci = vlan_tx_tag_get(skb);
1857                        status |= TP_STATUS_VLAN_VALID;
1858                } else {
1859                        h.h2->tp_vlan_tci = 0;
1860                }
1861                h.h2->tp_padding = 0;
1862                hdrlen = sizeof(*h.h2);
1863                break;
1864        case TPACKET_V3:
1865                /* tp_nxt_offset,vlan are already populated above.
1866                 * So DONT clear those fields here
1867                 */
1868                h.h3->tp_status |= status;
1869                h.h3->tp_len = skb->len;
1870                h.h3->tp_snaplen = snaplen;
1871                h.h3->tp_mac = macoff;
1872                h.h3->tp_net = netoff;
1873                if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
1874                                && shhwtstamps->syststamp.tv64)
1875                        ts = ktime_to_timespec(shhwtstamps->syststamp);
1876                else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
1877                                && shhwtstamps->hwtstamp.tv64)
1878                        ts = ktime_to_timespec(shhwtstamps->hwtstamp);
1879                else if (skb->tstamp.tv64)
1880                        ts = ktime_to_timespec(skb->tstamp);
1881                else
1882                        getnstimeofday(&ts);
1883                h.h3->tp_sec  = ts.tv_sec;
1884                h.h3->tp_nsec = ts.tv_nsec;
1885                hdrlen = sizeof(*h.h3);
1886                break;
1887        default:
1888                BUG();
1889        }
1890
1891        sll = h.raw + TPACKET_ALIGN(hdrlen);
1892        sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
1893        sll->sll_family = AF_PACKET;
1894        sll->sll_hatype = dev->type;
1895        sll->sll_protocol = skb->protocol;
1896        sll->sll_pkttype = skb->pkt_type;
1897        if (unlikely(po->origdev))
1898                sll->sll_ifindex = orig_dev->ifindex;
1899        else
1900                sll->sll_ifindex = dev->ifindex;
1901
1902        smp_mb();
1903#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
1904        {
1905                u8 *start, *end;
1906
1907                if (po->tp_version <= TPACKET_V2) {
1908                        end = (u8 *)PAGE_ALIGN((unsigned long)h.raw
1909                                + macoff + snaplen);
1910                        for (start = h.raw; start < end; start += PAGE_SIZE)
1911                                flush_dcache_page(pgv_to_page(start));
1912                }
1913                smp_wmb();
1914        }
1915#endif
1916        if (po->tp_version <= TPACKET_V2)
1917                __packet_set_status(po, h.raw, status);
1918        else
1919                prb_clear_blk_fill_status(&po->rx_ring);
1920
1921        sk->sk_data_ready(sk, 0);
1922
1923drop_n_restore:
1924        if (skb_head != skb->data && skb_shared(skb)) {
1925                skb->data = skb_head;
1926                skb->len = skb_len;
1927        }
1928drop:
1929        kfree_skb(skb);
1930        return 0;
1931
1932ring_is_full:
1933        po->stats.tp_drops++;
1934        spin_unlock(&sk->sk_receive_queue.lock);
1935
1936        sk->sk_data_ready(sk, 0);
1937        kfree_skb(copy_skb);
1938        goto drop_n_restore;
1939}
1940
1941static void tpacket_destruct_skb(struct sk_buff *skb)
1942{
1943        struct packet_sock *po = pkt_sk(skb->sk);
1944        void *ph;
1945
1946        if (likely(po->tx_ring.pg_vec)) {
1947                ph = skb_shinfo(skb)->destructor_arg;
1948                BUG_ON(atomic_read(&po->tx_ring.pending) == 0);
1949                atomic_dec(&po->tx_ring.pending);
1950                __packet_set_status(po, ph, TP_STATUS_AVAILABLE);
1951        }
1952
1953        sock_wfree(skb);
1954}
1955
1956static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
1957                void *frame, struct net_device *dev, int size_max,
1958                __be16 proto, unsigned char *addr, int hlen)
1959{
1960        union {
1961                struct tpacket_hdr *h1;
1962                struct tpacket2_hdr *h2;
1963                void *raw;
1964        } ph;
1965        int to_write, offset, len, tp_len, nr_frags, len_max;
1966        struct socket *sock = po->sk.sk_socket;
1967        struct page *page;
1968        void *data;
1969        int err;
1970
1971        ph.raw = frame;
1972
1973        skb->protocol = proto;
1974        skb->dev = dev;
1975        skb->priority = po->sk.sk_priority;
1976        skb->mark = po->sk.sk_mark;
1977        skb_shinfo(skb)->destructor_arg = ph.raw;
1978
1979        switch (po->tp_version) {
1980        case TPACKET_V2:
1981                tp_len = ph.h2->tp_len;
1982                break;
1983        default:
1984                tp_len = ph.h1->tp_len;
1985                break;
1986        }
1987        if (unlikely(tp_len > size_max)) {
1988                pr_err("packet size is too long (%d > %d)\n", tp_len, size_max);
1989                return -EMSGSIZE;
1990        }
1991
1992        skb_reserve(skb, hlen);
1993        skb_reset_network_header(skb);
1994
1995        data = ph.raw + po->tp_hdrlen - sizeof(struct sockaddr_ll);
1996        to_write = tp_len;
1997
1998        if (sock->type == SOCK_DGRAM) {
1999                err = dev_hard_header(skb, dev, ntohs(proto), addr,
2000                                NULL, tp_len);
2001                if (unlikely(err < 0))
2002                        return -EINVAL;
2003        } else if (dev->hard_header_len) {
2004                /* net device doesn't like empty head */
2005                if (unlikely(tp_len <= dev->hard_header_len)) {
2006                        pr_err("packet size is too short (%d < %d)\n",
2007                               tp_len, dev->hard_header_len);
2008                        return -EINVAL;
2009                }
2010
2011                skb_push(skb, dev->hard_header_len);
2012                err = skb_store_bits(skb, 0, data,
2013                                dev->hard_header_len);
2014                if (unlikely(err))
2015                        return err;
2016
2017                data += dev->hard_header_len;
2018                to_write -= dev->hard_header_len;
2019        }
2020
2021        err = -EFAULT;
2022        offset = offset_in_page(data);
2023        len_max = PAGE_SIZE - offset;
2024        len = ((to_write > len_max) ? len_max : to_write);
2025
2026        skb->data_len = to_write;
2027        skb->len += to_write;
2028        skb->truesize += to_write;
2029        atomic_add(to_write, &po->sk.sk_wmem_alloc);
2030
2031        while (likely(to_write)) {
2032                nr_frags = skb_shinfo(skb)->nr_frags;
2033
2034                if (unlikely(nr_frags >= MAX_SKB_FRAGS)) {
2035                        pr_err("Packet exceed the number of skb frags(%lu)\n",
2036                               MAX_SKB_FRAGS);
2037                        return -EFAULT;
2038                }
2039
2040                page = pgv_to_page(data);
2041                data += len;
2042                flush_dcache_page(page);
2043                get_page(page);
2044                skb_fill_page_desc(skb, nr_frags, page, offset, len);
2045                to_write -= len;
2046                offset = 0;
2047                len_max = PAGE_SIZE;
2048                len = ((to_write > len_max) ? len_max : to_write);
2049        }
2050
2051        return tp_len;
2052}
2053
2054static int tpacket_snd(struct packet_sock *po, struct msghdr *msg)
2055{
2056        struct sk_buff *skb;
2057        struct net_device *dev;
2058        __be16 proto;
2059        bool need_rls_dev = false;
2060        int err, reserve = 0;
2061        void *ph;
2062        struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2063        int tp_len, size_max;
2064        unsigned char *addr;
2065        int len_sum = 0;
2066        int status = 0;
2067        int hlen, tlen;
2068
2069        mutex_lock(&po->pg_vec_lock);
2070
2071        err = -EBUSY;
2072        if (saddr == NULL) {
2073                dev = po->prot_hook.dev;
2074                proto   = po->num;
2075                addr    = NULL;
2076        } else {
2077                err = -EINVAL;
2078                if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2079                        goto out;
2080                if (msg->msg_namelen < (saddr->sll_halen
2081                                        + offsetof(struct sockaddr_ll,
2082                                                sll_addr)))
2083                        goto out;
2084                proto   = saddr->sll_protocol;
2085                addr    = saddr->sll_addr;
2086                dev = dev_get_by_index(sock_net(&po->sk), saddr->sll_ifindex);
2087                need_rls_dev = true;
2088        }
2089
2090        err = -ENXIO;
2091        if (unlikely(dev == NULL))
2092                goto out;
2093
2094        reserve = dev->hard_header_len;
2095
2096        err = -ENETDOWN;
2097        if (unlikely(!(dev->flags & IFF_UP)))
2098                goto out_put;
2099
2100        size_max = po->tx_ring.frame_size
2101                - (po->tp_hdrlen - sizeof(struct sockaddr_ll));
2102
2103        if (size_max > dev->mtu + reserve)
2104                size_max = dev->mtu + reserve;
2105
2106        do {
2107                ph = packet_current_frame(po, &po->tx_ring,
2108                                TP_STATUS_SEND_REQUEST);
2109
2110                if (unlikely(ph == NULL)) {
2111                        schedule();
2112                        continue;
2113                }
2114
2115                status = TP_STATUS_SEND_REQUEST;
2116                hlen = LL_RESERVED_SPACE(dev);
2117                tlen = dev->needed_tailroom;
2118                skb = sock_alloc_send_skb(&po->sk,
2119                                hlen + tlen + sizeof(struct sockaddr_ll),
2120                                0, &err);
2121
2122                if (unlikely(skb == NULL))
2123                        goto out_status;
2124
2125                tp_len = tpacket_fill_skb(po, skb, ph, dev, size_max, proto,
2126                                addr, hlen);
2127
2128                if (unlikely(tp_len < 0)) {
2129                        if (po->tp_loss) {
2130                                __packet_set_status(po, ph,
2131                                                TP_STATUS_AVAILABLE);
2132                                packet_increment_head(&po->tx_ring);
2133                                kfree_skb(skb);
2134                                continue;
2135                        } else {
2136                                status = TP_STATUS_WRONG_FORMAT;
2137                                err = tp_len;
2138                                goto out_status;
2139                        }
2140                }
2141
2142                skb->destructor = tpacket_destruct_skb;
2143                __packet_set_status(po, ph, TP_STATUS_SENDING);
2144                atomic_inc(&po->tx_ring.pending);
2145
2146                status = TP_STATUS_SEND_REQUEST;
2147                err = dev_queue_xmit(skb);
2148                if (unlikely(err > 0)) {
2149                        err = net_xmit_errno(err);
2150                        if (err && __packet_get_status(po, ph) ==
2151                                   TP_STATUS_AVAILABLE) {
2152                                /* skb was destructed already */
2153                                skb = NULL;
2154                                goto out_status;
2155                        }
2156                        /*
2157                         * skb was dropped but not destructed yet;
2158                         * let's treat it like congestion or err < 0
2159                         */
2160                        err = 0;
2161                }
2162                packet_increment_head(&po->tx_ring);
2163                len_sum += tp_len;
2164        } while (likely((ph != NULL) ||
2165                        ((!(msg->msg_flags & MSG_DONTWAIT)) &&
2166                         (atomic_read(&po->tx_ring.pending))))
2167                );
2168
2169        err = len_sum;
2170        goto out_put;
2171
2172out_status:
2173        __packet_set_status(po, ph, status);
2174        kfree_skb(skb);
2175out_put:
2176        if (need_rls_dev)
2177                dev_put(dev);
2178out:
2179        mutex_unlock(&po->pg_vec_lock);
2180        return err;
2181}
2182
2183static struct sk_buff *packet_alloc_skb(struct sock *sk, size_t prepad,
2184                                        size_t reserve, size_t len,
2185                                        size_t linear, int noblock,
2186                                        int *err)
2187{
2188        struct sk_buff *skb;
2189
2190        /* Under a page?  Don't bother with paged skb. */
2191        if (prepad + len < PAGE_SIZE || !linear)
2192                linear = len;
2193
2194        skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
2195                                   err);
2196        if (!skb)
2197                return NULL;
2198
2199        skb_reserve(skb, reserve);
2200        skb_put(skb, linear);
2201        skb->data_len = len - linear;
2202        skb->len += len - linear;
2203
2204        return skb;
2205}
2206
2207static int packet_snd(struct socket *sock,
2208                          struct msghdr *msg, size_t len)
2209{
2210        struct sock *sk = sock->sk;
2211        struct sockaddr_ll *saddr = (struct sockaddr_ll *)msg->msg_name;
2212        struct sk_buff *skb;
2213        struct net_device *dev;
2214        __be16 proto;
2215        bool need_rls_dev = false;
2216        unsigned char *addr;
2217        int err, reserve = 0;
2218        struct virtio_net_hdr vnet_hdr = { 0 };
2219        int offset = 0;
2220        int vnet_hdr_len;
2221        struct packet_sock *po = pkt_sk(sk);
2222        unsigned short gso_type = 0;
2223        int hlen, tlen;
2224        int extra_len = 0;
2225
2226        /*
2227         *      Get and verify the address.
2228         */
2229
2230        if (saddr == NULL) {
2231                dev = po->prot_hook.dev;
2232                proto   = po->num;
2233                addr    = NULL;
2234        } else {
2235                err = -EINVAL;
2236                if (msg->msg_namelen < sizeof(struct sockaddr_ll))
2237                        goto out;
2238                if (msg->msg_namelen < (saddr->sll_halen + offsetof(struct sockaddr_ll, sll_addr)))
2239                        goto out;
2240                proto   = saddr->sll_protocol;
2241                addr    = saddr->sll_addr;
2242                dev = dev_get_by_index(sock_net(sk), saddr->sll_ifindex);
2243                need_rls_dev = true;
2244        }
2245
2246        err = -ENXIO;
2247        if (dev == NULL)
2248                goto out_unlock;
2249        if (sock->type == SOCK_RAW)
2250                reserve = dev->hard_header_len;
2251
2252        err = -ENETDOWN;
2253        if (!(dev->flags & IFF_UP))
2254                goto out_unlock;
2255
2256        if (po->has_vnet_hdr) {
2257                vnet_hdr_len = sizeof(vnet_hdr);
2258
2259                err = -EINVAL;
2260                if (len < vnet_hdr_len)
2261                        goto out_unlock;
2262
2263                len -= vnet_hdr_len;
2264
2265                err = memcpy_fromiovec((void *)&vnet_hdr, msg->msg_iov,
2266                                       vnet_hdr_len);
2267                if (err < 0)
2268                        goto out_unlock;
2269
2270                if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
2271                    (vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
2272                      vnet_hdr.hdr_len))
2273                        vnet_hdr.hdr_len = vnet_hdr.csum_start +
2274                                                 vnet_hdr.csum_offset + 2;
2275
2276                err = -EINVAL;
2277                if (vnet_hdr.hdr_len > len)
2278                        goto out_unlock;
2279
2280                if (vnet_hdr.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
2281                        switch (vnet_hdr.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
2282                        case VIRTIO_NET_HDR_GSO_TCPV4:
2283                                gso_type = SKB_GSO_TCPV4;
2284                                break;
2285                        case VIRTIO_NET_HDR_GSO_TCPV6:
2286                                gso_type = SKB_GSO_TCPV6;
2287                                break;
2288                        case VIRTIO_NET_HDR_GSO_UDP:
2289                                gso_type = SKB_GSO_UDP;
2290                                break;
2291                        default:
2292                                goto out_unlock;
2293                        }
2294
2295                        if (vnet_hdr.gso_type & VIRTIO_NET_HDR_GSO_ECN)
2296                                gso_type |= SKB_GSO_TCP_ECN;
2297
2298                        if (vnet_hdr.gso_size == 0)
2299                                goto out_unlock;
2300
2301                }
2302        }
2303
2304        if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
2305                if (!netif_supports_nofcs(dev)) {
2306                        err = -EPROTONOSUPPORT;
2307                        goto out_unlock;
2308                }
2309                extra_len = 4; /* We're doing our own CRC */
2310        }
2311
2312        err = -EMSGSIZE;
2313        if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
2314                goto out_unlock;
2315
2316        err = -ENOBUFS;
2317        hlen = LL_RESERVED_SPACE(dev);
2318        tlen = dev->needed_tailroom;
2319        skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len,
2320                               msg->msg_flags & MSG_DONTWAIT, &err);
2321        if (skb == NULL)
2322                goto out_unlock;
2323
2324        skb_set_network_header(skb, reserve);
2325
2326        err = -EINVAL;
2327        if (sock->type == SOCK_DGRAM &&
2328            (offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len)) < 0)
2329                goto out_free;
2330
2331        /* Returns -EFAULT on error */
2332        err = skb_copy_datagram_from_iovec(skb, offset, msg->msg_iov, 0, len);
2333        if (err)
2334                goto out_free;
2335        err = sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags);
2336        if (err < 0)
2337                goto out_free;
2338
2339        if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
2340                /* Earlier code assumed this would be a VLAN pkt,
2341                 * double-check this now that we have the actual
2342                 * packet in hand.
2343                 */
2344                struct ethhdr *ehdr;
2345                skb_reset_mac_header(skb);
2346                ehdr = eth_hdr(skb);
2347                if (ehdr->h_proto != htons(ETH_P_8021Q)) {
2348                        err = -EMSGSIZE;
2349                        goto out_free;
2350                }
2351        }
2352
2353        skb->protocol = proto;
2354        skb->dev = dev;
2355        skb->priority = sk->sk_priority;
2356        skb->mark = sk->sk_mark;
2357
2358        if (po->has_vnet_hdr) {
2359                if (vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
2360                        if (!skb_partial_csum_set(skb, vnet_hdr.csum_start,
2361                                                  vnet_hdr.csum_offset)) {
2362                                err = -EINVAL;
2363                                goto out_free;
2364                        }
2365                }
2366
2367                skb_shinfo(skb)->gso_size = vnet_hdr.gso_size;
2368                skb_shinfo(skb)->gso_type = gso_type;
2369
2370                /* Header must be checked, and gso_segs computed. */
2371                skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
2372                skb_shinfo(skb)->gso_segs = 0;
2373
2374                len += vnet_hdr_len;
2375        }
2376
2377        if (unlikely(extra_len == 4))
2378                skb->no_fcs = 1;
2379
2380        /*
2381         *      Now send it
2382         */
2383
2384        err = dev_queue_xmit(skb);
2385        if (err > 0 && (err = net_xmit_errno(err)) != 0)
2386                goto out_unlock;
2387
2388        if (need_rls_dev)
2389                dev_put(dev);
2390
2391        return len;
2392
2393out_free:
2394        kfree_skb(skb);
2395out_unlock:
2396        if (dev && need_rls_dev)
2397                dev_put(dev);
2398out:
2399        return err;
2400}
2401
2402static int packet_sendmsg(struct kiocb *iocb, struct socket *sock,
2403                struct msghdr *msg, size_t len)
2404{
2405        struct sock *sk = sock->sk;
2406        struct packet_sock *po = pkt_sk(sk);
2407        if (po->tx_ring.pg_vec)
2408                return tpacket_snd(po, msg);
2409        else
2410                return packet_snd(sock, msg, len);
2411}
2412
2413/*
2414 *      Close a PACKET socket. This is fairly simple. We immediately go
2415 *      to 'closed' state and remove our protocol entry in the device list.
2416 */
2417
2418static int packet_release(struct socket *sock)
2419{
2420        struct sock *sk = sock->sk;
2421        struct packet_sock *po;
2422        struct net *net;
2423        union tpacket_req_u req_u;
2424
2425        if (!sk)
2426                return 0;
2427
2428        net = sock_net(sk);
2429        po = pkt_sk(sk);
2430
2431        spin_lock_bh(&net->packet.sklist_lock);
2432        sk_del_node_init_rcu(sk);
2433        sock_prot_inuse_add(net, sk->sk_prot, -1);
2434        spin_unlock_bh(&net->packet.sklist_lock);
2435
2436        spin_lock(&po->bind_lock);
2437        unregister_prot_hook(sk, false);
2438        if (po->prot_hook.dev) {
2439                dev_put(po->prot_hook.dev);
2440                po->prot_hook.dev = NULL;
2441        }
2442        spin_unlock(&po->bind_lock);
2443
2444        packet_flush_mclist(sk);
2445
2446        memset(&req_u, 0, sizeof(req_u));
2447
2448        if (po->rx_ring.pg_vec)
2449                packet_set_ring(sk, &req_u, 1, 0);
2450
2451        if (po->tx_ring.pg_vec)
2452                packet_set_ring(sk, &req_u, 1, 1);
2453
2454        fanout_release(sk);
2455
2456        synchronize_net();
2457        /*
2458         *      Now the socket is dead. No more input will appear.
2459         */
2460        sock_orphan(sk);
2461        sock->sk = NULL;
2462
2463        /* Purge queues */
2464
2465        skb_queue_purge(&sk->sk_receive_queue);
2466        sk_refcnt_debug_release(sk);
2467
2468        sock_put(sk);
2469        return 0;
2470}
2471
2472/*
2473 *      Attach a packet hook.
2474 */
2475
2476static int packet_do_bind(struct sock *sk, struct net_device *dev, __be16 protocol)
2477{
2478        struct packet_sock *po = pkt_sk(sk);
2479
2480        if (po->fanout) {
2481                if (dev)
2482                        dev_put(dev);
2483
2484                return -EINVAL;
2485        }
2486
2487        lock_sock(sk);
2488
2489        spin_lock(&po->bind_lock);
2490        unregister_prot_hook(sk, true);
2491        po->num = protocol;
2492        po->prot_hook.type = protocol;
2493        if (po->prot_hook.dev)
2494                dev_put(po->prot_hook.dev);
2495        po->prot_hook.dev = dev;
2496
2497        po->ifindex = dev ? dev->ifindex : 0;
2498
2499        if (protocol == 0)
2500                goto out_unlock;
2501
2502        if (!dev || (dev->flags & IFF_UP)) {
2503                register_prot_hook(sk);
2504        } else {
2505                sk->sk_err = ENETDOWN;
2506                if (!sock_flag(sk, SOCK_DEAD))
2507                        sk->sk_error_report(sk);
2508        }
2509
2510out_unlock:
2511        spin_unlock(&po->bind_lock);
2512        release_sock(sk);
2513        return 0;
2514}
2515
2516/*
2517 *      Bind a packet socket to a device
2518 */
2519
2520static int packet_bind_spkt(struct socket *sock, struct sockaddr *uaddr,
2521                            int addr_len)
2522{
2523        struct sock *sk = sock->sk;
2524        char name[15];
2525        struct net_device *dev;
2526        int err = -ENODEV;
2527
2528        /*
2529         *      Check legality
2530         */
2531
2532        if (addr_len != sizeof(struct sockaddr))
2533                return -EINVAL;
2534        strlcpy(name, uaddr->sa_data, sizeof(name));
2535
2536        dev = dev_get_by_name(sock_net(sk), name);
2537        if (dev)
2538                err = packet_do_bind(sk, dev, pkt_sk(sk)->num);
2539        return err;
2540}
2541
2542static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
2543{
2544        struct sockaddr_ll *sll = (struct sockaddr_ll *)uaddr;
2545        struct sock *sk = sock->sk;
2546        struct net_device *dev = NULL;
2547        int err;
2548
2549
2550        /*
2551         *      Check legality
2552         */
2553
2554        if (addr_len < sizeof(struct sockaddr_ll))
2555                return -EINVAL;
2556        if (sll->sll_family != AF_PACKET)
2557                return -EINVAL;
2558
2559        if (sll->sll_ifindex) {
2560                err = -ENODEV;
2561                dev = dev_get_by_index(sock_net(sk), sll->sll_ifindex);
2562                if (dev == NULL)
2563                        goto out;
2564        }
2565        err = packet_do_bind(sk, dev, sll->sll_protocol ? : pkt_sk(sk)->num);
2566
2567out:
2568        return err;
2569}
2570
2571static struct proto packet_proto = {
2572        .name     = "PACKET",
2573        .owner    = THIS_MODULE,
2574        .obj_size = sizeof(struct packet_sock),
2575};
2576
2577/*
2578 *      Create a packet of type SOCK_PACKET.
2579 */
2580
2581static int packet_create(struct net *net, struct socket *sock, int protocol,
2582                         int kern)
2583{
2584        struct sock *sk;
2585        struct packet_sock *po;
2586        __be16 proto = (__force __be16)protocol; /* weird, but documented */
2587        int err;
2588
2589        if (!capable(CAP_NET_RAW))
2590                return -EPERM;
2591        if (sock->type != SOCK_DGRAM && sock->type != SOCK_RAW &&
2592            sock->type != SOCK_PACKET)
2593                return -ESOCKTNOSUPPORT;
2594
2595        sock->state = SS_UNCONNECTED;
2596
2597        err = -ENOBUFS;
2598        sk = sk_alloc(net, PF_PACKET, GFP_KERNEL, &packet_proto);
2599        if (sk == NULL)
2600                goto out;
2601
2602        sock->ops = &packet_ops;
2603        if (sock->type == SOCK_PACKET)
2604                sock->ops = &packet_ops_spkt;
2605
2606        sock_init_data(sock, sk);
2607
2608        po = pkt_sk(sk);
2609        sk->sk_family = PF_PACKET;
2610        po->num = proto;
2611
2612        sk->sk_destruct = packet_sock_destruct;
2613        sk_refcnt_debug_inc(sk);
2614
2615        /*
2616         *      Attach a protocol block
2617         */
2618
2619        spin_lock_init(&po->bind_lock);
2620        mutex_init(&po->pg_vec_lock);
2621        po->prot_hook.func = packet_rcv;
2622
2623        if (sock->type == SOCK_PACKET)
2624                po->prot_hook.func = packet_rcv_spkt;
2625
2626        po->prot_hook.af_packet_priv = sk;
2627
2628        if (proto) {
2629                po->prot_hook.type = proto;
2630                register_prot_hook(sk);
2631        }
2632
2633        spin_lock_bh(&net->packet.sklist_lock);
2634        sk_add_node_rcu(sk, &net->packet.sklist);
2635        sock_prot_inuse_add(net, &packet_proto, 1);
2636        spin_unlock_bh(&net->packet.sklist_lock);
2637
2638        return 0;
2639out:
2640        return err;
2641}
2642
2643static int packet_recv_error(struct sock *sk, struct msghdr *msg, int len)
2644{
2645        struct sock_exterr_skb *serr;
2646        struct sk_buff *skb, *skb2;
2647        int copied, err;
2648
2649        err = -EAGAIN;
2650        skb = skb_dequeue(&sk->sk_error_queue);
2651        if (skb == NULL)
2652                goto out;
2653
2654        copied = skb->len;
2655        if (copied > len) {
2656                msg->msg_flags |= MSG_TRUNC;
2657                copied = len;
2658        }
2659        err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2660        if (err)
2661                goto out_free_skb;
2662
2663        sock_recv_timestamp(msg, sk, skb);
2664
2665        serr = SKB_EXT_ERR(skb);
2666        put_cmsg(msg, SOL_PACKET, PACKET_TX_TIMESTAMP,
2667                 sizeof(serr->ee), &serr->ee);
2668
2669        msg->msg_flags |= MSG_ERRQUEUE;
2670        err = copied;
2671
2672        /* Reset and regenerate socket error */
2673        spin_lock_bh(&sk->sk_error_queue.lock);
2674        sk->sk_err = 0;
2675        if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2676                sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2677                spin_unlock_bh(&sk->sk_error_queue.lock);
2678                sk->sk_error_report(sk);
2679        } else
2680                spin_unlock_bh(&sk->sk_error_queue.lock);
2681
2682out_free_skb:
2683        kfree_skb(skb);
2684out:
2685        return err;
2686}
2687
2688/*
2689 *      Pull a packet from our receive queue and hand it to the user.
2690 *      If necessary we block.
2691 */
2692
2693static int packet_recvmsg(struct kiocb *iocb, struct socket *sock,
2694                          struct msghdr *msg, size_t len, int flags)
2695{
2696        struct sock *sk = sock->sk;
2697        struct sk_buff *skb;
2698        int copied, err;
2699        struct sockaddr_ll *sll;
2700        int vnet_hdr_len = 0;
2701
2702        err = -EINVAL;
2703        if (flags & ~(MSG_PEEK|MSG_DONTWAIT|MSG_TRUNC|MSG_CMSG_COMPAT|MSG_ERRQUEUE))
2704                goto out;
2705
2706#if 0
2707        /* What error should we return now? EUNATTACH? */
2708        if (pkt_sk(sk)->ifindex < 0)
2709                return -ENODEV;
2710#endif
2711
2712        if (flags & MSG_ERRQUEUE) {
2713                err = packet_recv_error(sk, msg, len);
2714                goto out;
2715        }
2716
2717        /*
2718         *      Call the generic datagram receiver. This handles all sorts
2719         *      of horrible races and re-entrancy so we can forget about it
2720         *      in the protocol layers.
2721         *
2722         *      Now it will return ENETDOWN, if device have just gone down,
2723         *      but then it will block.
2724         */
2725
2726        skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
2727
2728        /*
2729         *      An error occurred so return it. Because skb_recv_datagram()
2730         *      handles the blocking we don't see and worry about blocking
2731         *      retries.
2732         */
2733
2734        if (skb == NULL)
2735                goto out;
2736
2737        if (pkt_sk(sk)->has_vnet_hdr) {
2738                struct virtio_net_hdr vnet_hdr = { 0 };
2739
2740                err = -EINVAL;
2741                vnet_hdr_len = sizeof(vnet_hdr);
2742                if (len < vnet_hdr_len)
2743                        goto out_free;
2744
2745                len -= vnet_hdr_len;
2746
2747                if (skb_is_gso(skb)) {
2748                        struct skb_shared_info *sinfo = skb_shinfo(skb);
2749
2750                        /* This is a hint as to how much should be linear. */
2751                        vnet_hdr.hdr_len = skb_headlen(skb);
2752                        vnet_hdr.gso_size = sinfo->gso_size;
2753                        if (sinfo->gso_type & SKB_GSO_TCPV4)
2754                                vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
2755                        else if (sinfo->gso_type & SKB_GSO_TCPV6)
2756                                vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
2757                        else if (sinfo->gso_type & SKB_GSO_UDP)
2758                                vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_UDP;
2759                        else if (sinfo->gso_type & SKB_GSO_FCOE)
2760                                goto out_free;
2761                        else
2762                                BUG();
2763                        if (sinfo->gso_type & SKB_GSO_TCP_ECN)
2764                                vnet_hdr.gso_type |= VIRTIO_NET_HDR_GSO_ECN;
2765                } else
2766                        vnet_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
2767
2768                if (skb->ip_summed == CHECKSUM_PARTIAL) {
2769                        vnet_hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
2770                        vnet_hdr.csum_start = skb_checksum_start_offset(skb);
2771                        vnet_hdr.csum_offset = skb->csum_offset;
2772                } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2773                        vnet_hdr.flags = VIRTIO_NET_HDR_F_DATA_VALID;
2774                } /* else everything is zero */
2775
2776                err = memcpy_toiovec(msg->msg_iov, (void *)&vnet_hdr,
2777                                     vnet_hdr_len);
2778                if (err < 0)
2779                        goto out_free;
2780        }
2781
2782        /*
2783         *      If the address length field is there to be filled in, we fill
2784         *      it in now.
2785         */
2786
2787        sll = &PACKET_SKB_CB(skb)->sa.ll;
2788        if (sock->type == SOCK_PACKET)
2789                msg->msg_namelen = sizeof(struct sockaddr_pkt);
2790        else
2791                msg->msg_namelen = sll->sll_halen + offsetof(struct sockaddr_ll, sll_addr);
2792
2793        /*
2794         *      You lose any data beyond the buffer you gave. If it worries a
2795         *      user program they can ask the device for its MTU anyway.
2796         */
2797
2798        copied = skb->len;
2799        if (copied > len) {
2800                copied = len;
2801                msg->msg_flags |= MSG_TRUNC;
2802        }
2803
2804        err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2805        if (err)
2806                goto out_free;
2807
2808        sock_recv_ts_and_drops(msg, sk, skb);
2809
2810        if (msg->msg_name)
2811                memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa,
2812                       msg->msg_namelen);
2813
2814        if (pkt_sk(sk)->auxdata) {
2815                struct tpacket_auxdata aux;
2816
2817                aux.tp_status = TP_STATUS_USER;
2818                if (skb->ip_summed == CHECKSUM_PARTIAL)
2819                        aux.tp_status |= TP_STATUS_CSUMNOTREADY;
2820                aux.tp_len = PACKET_SKB_CB(skb)->origlen;
2821                aux.tp_snaplen = skb->len;
2822                aux.tp_mac = 0;
2823                aux.tp_net = skb_network_offset(skb);
2824                if (vlan_tx_tag_present(skb)) {
2825                        aux.tp_vlan_tci = vlan_tx_tag_get(skb);
2826                        aux.tp_status |= TP_STATUS_VLAN_VALID;
2827                } else {
2828                        aux.tp_vlan_tci = 0;
2829                }
2830                aux.tp_padding = 0;
2831                put_cmsg(msg, SOL_PACKET, PACKET_AUXDATA, sizeof(aux), &aux);
2832        }
2833
2834        /*
2835         *      Free or return the buffer as appropriate. Again this
2836         *      hides all the races and re-entrancy issues from us.
2837         */
2838        err = vnet_hdr_len + ((flags&MSG_TRUNC) ? skb->len : copied);
2839
2840out_free:
2841        skb_free_datagram(sk, skb);
2842out:
2843        return err;
2844}
2845
2846static int packet_getname_spkt(struct socket *sock, struct sockaddr *uaddr,
2847                               int *uaddr_len, int peer)
2848{
2849        struct net_device *dev;
2850        struct sock *sk = sock->sk;
2851
2852        if (peer)
2853                return -EOPNOTSUPP;
2854
2855        uaddr->sa_family = AF_PACKET;
2856        rcu_read_lock();
2857        dev = dev_get_by_index_rcu(sock_net(sk), pkt_sk(sk)->ifindex);
2858        if (dev)
2859                strncpy(uaddr->sa_data, dev->name, 14);
2860        else
2861                memset(uaddr->sa_data, 0, 14);
2862        rcu_read_unlock();
2863        *uaddr_len = sizeof(*uaddr);
2864
2865        return 0;
2866}
2867
2868static int packet_getname(struct socket *sock, struct sockaddr *uaddr,
2869                          int *uaddr_len, int peer)
2870{
2871        struct net_device *dev;
2872        struct sock *sk = sock->sk;
2873        struct packet_sock *po = pkt_sk(sk);
2874        DECLARE_SOCKADDR(struct sockaddr_ll *, sll, uaddr);
2875
2876        if (peer)
2877                return -EOPNOTSUPP;
2878
2879        sll->sll_family = AF_PACKET;
2880        sll->sll_ifindex = po->ifindex;
2881        sll->sll_protocol = po->num;
2882        sll->sll_pkttype = 0;
2883        rcu_read_lock();
2884        dev = dev_get_by_index_rcu(sock_net(sk), po->ifindex);
2885        if (dev) {
2886                sll->sll_hatype = dev->type;
2887                sll->sll_halen = dev->addr_len;
2888                memcpy(sll->sll_addr, dev->dev_addr, dev->addr_len);
2889        } else {
2890                sll->sll_hatype = 0;    /* Bad: we have no ARPHRD_UNSPEC */
2891                sll->sll_halen = 0;
2892        }
2893        rcu_read_unlock();
2894        *uaddr_len = offsetof(struct sockaddr_ll, sll_addr) + sll->sll_halen;
2895
2896        return 0;
2897}
2898
2899static int packet_dev_mc(struct net_device *dev, struct packet_mclist *i,
2900                         int what)
2901{
2902        switch (i->type) {
2903        case PACKET_MR_MULTICAST:
2904                if (i->alen != dev->addr_len)
2905                        return -EINVAL;
2906                if (what > 0)
2907                        return dev_mc_add(dev, i->addr);
2908                else
2909                        return dev_mc_del(dev, i->addr);
2910                break;
2911        case PACKET_MR_PROMISC:
2912                return dev_set_promiscuity(dev, what);
2913                break;
2914        case PACKET_MR_ALLMULTI:
2915                return dev_set_allmulti(dev, what);
2916                break;
2917        case PACKET_MR_UNICAST:
2918                if (i->alen != dev->addr_len)
2919                        return -EINVAL;
2920                if (what > 0)
2921                        return dev_uc_add(dev, i->addr);
2922                else
2923                        return dev_uc_del(dev, i->addr);
2924                break;
2925        default:
2926                break;
2927        }
2928        return 0;
2929}
2930
2931static void packet_dev_mclist(struct net_device *dev, struct packet_mclist *i, int what)
2932{
2933        for ( ; i; i = i->next) {
2934                if (i->ifindex == dev->ifindex)
2935                        packet_dev_mc(dev, i, what);
2936        }
2937}
2938
2939static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
2940{
2941        struct packet_sock *po = pkt_sk(sk);
2942        struct packet_mclist *ml, *i;
2943        struct net_device *dev;
2944        int err;
2945
2946        rtnl_lock();
2947
2948        err = -ENODEV;
2949        dev = __dev_get_by_index(sock_net(sk), mreq->mr_ifindex);
2950        if (!dev)
2951                goto done;
2952
2953        err = -EINVAL;
2954        if (mreq->mr_alen > dev->addr_len)
2955                goto done;
2956
2957        err = -ENOBUFS;
2958        i = kmalloc(sizeof(*i), GFP_KERNEL);
2959        if (i == NULL)
2960                goto done;
2961
2962        err = 0;
2963        for (ml = po->mclist; ml; ml = ml->next) {
2964                if (ml->ifindex == mreq->mr_ifindex &&
2965                    ml->type == mreq->mr_type &&
2966                    ml->alen == mreq->mr_alen &&
2967                    memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
2968                        ml->count++;
2969                        /* Free the new element ... */
2970                        kfree(i);
2971                        goto done;
2972                }
2973        }
2974
2975        i->type = mreq->mr_type;
2976        i->ifindex = mreq->mr_ifindex;
2977        i->alen = mreq->mr_alen;
2978        memcpy(i->addr, mreq->mr_address, i->alen);
2979        i->count = 1;
2980        i->next = po->mclist;
2981        po->mclist = i;
2982        err = packet_dev_mc(dev, i, 1);
2983        if (err) {
2984                po->mclist = i->next;
2985                kfree(i);
2986        }
2987
2988done:
2989        rtnl_unlock();
2990        return err;
2991}
2992
2993static int packet_mc_drop(struct sock *sk, struct packet_mreq_max *mreq)
2994{
2995        struct packet_mclist *ml, **mlp;
2996
2997        rtnl_lock();
2998
2999        for (mlp = &pkt_sk(sk)->mclist; (ml = *mlp) != NULL; mlp = &ml->next) {
3000                if (ml->ifindex == mreq->mr_ifindex &&
3001                    ml->type == mreq->mr_type &&
3002                    ml->alen == mreq->mr_alen &&
3003                    memcmp(ml->addr, mreq->mr_address, ml->alen) == 0) {
3004                        if (--ml->count == 0) {
3005                                struct net_device *dev;
3006                                *mlp = ml->next;
3007                                dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3008                                if (dev)
3009                                        packet_dev_mc(dev, ml, -1);
3010                                kfree(ml);
3011                        }
3012                        rtnl_unlock();
3013                        return 0;
3014                }
3015        }
3016        rtnl_unlock();
3017        return -EADDRNOTAVAIL;
3018}
3019
3020static void packet_flush_mclist(struct sock *sk)
3021{
3022        struct packet_sock *po = pkt_sk(sk);
3023        struct packet_mclist *ml;
3024
3025        if (!po->mclist)
3026                return;
3027
3028        rtnl_lock();
3029        while ((ml = po->mclist) != NULL) {
3030                struct net_device *dev;
3031
3032                po->mclist = ml->next;
3033                dev = __dev_get_by_index(sock_net(sk), ml->ifindex);
3034                if (dev != NULL)
3035                        packet_dev_mc(dev, ml, -1);
3036                kfree(ml);
3037        }
3038        rtnl_unlock();
3039}
3040
3041static int
3042packet_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen)
3043{
3044        struct sock *sk = sock->sk;
3045        struct packet_sock *po = pkt_sk(sk);
3046        int ret;
3047
3048        if (level != SOL_PACKET)
3049                return -ENOPROTOOPT;
3050
3051        switch (optname) {
3052        case PACKET_ADD_MEMBERSHIP:
3053        case PACKET_DROP_MEMBERSHIP:
3054        {
3055                struct packet_mreq_max mreq;
3056                int len = optlen;
3057                memset(&mreq, 0, sizeof(mreq));
3058                if (len < sizeof(struct packet_mreq))
3059                        return -EINVAL;
3060                if (len > sizeof(mreq))
3061                        len = sizeof(mreq);
3062                if (copy_from_user(&mreq, optval, len))
3063                        return -EFAULT;
3064                if (len < (mreq.mr_alen + offsetof(struct packet_mreq, mr_address)))
3065                        return -EINVAL;
3066                if (optname == PACKET_ADD_MEMBERSHIP)
3067                        ret = packet_mc_add(sk, &mreq);
3068                else
3069                        ret = packet_mc_drop(sk, &mreq);
3070                return ret;
3071        }
3072
3073        case PACKET_RX_RING:
3074        case PACKET_TX_RING:
3075        {
3076                union tpacket_req_u req_u;
3077                int len;
3078
3079                switch (po->tp_version) {
3080                case TPACKET_V1:
3081                case TPACKET_V2:
3082                        len = sizeof(req_u.req);
3083                        break;
3084                case TPACKET_V3:
3085                default:
3086                        len = sizeof(req_u.req3);
3087                        break;
3088                }
3089                if (optlen < len)
3090                        return -EINVAL;
3091                if (pkt_sk(sk)->has_vnet_hdr)
3092                        return -EINVAL;
3093                if (copy_from_user(&req_u.req, optval, len))
3094                        return -EFAULT;
3095                return packet_set_ring(sk, &req_u, 0,
3096                        optname == PACKET_TX_RING);
3097        }
3098        case PACKET_COPY_THRESH:
3099        {
3100                int val;
3101
3102                if (optlen != sizeof(val))
3103                        return -EINVAL;
3104                if (copy_from_user(&val, optval, sizeof(val)))
3105                        return -EFAULT;
3106
3107                pkt_sk(sk)->copy_thresh = val;
3108                return 0;
3109        }
3110        case PACKET_VERSION:
3111        {
3112                int val;
3113
3114                if (optlen != sizeof(val))
3115                        return -EINVAL;
3116                if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3117                        return -EBUSY;
3118                if (copy_from_user(&val, optval, sizeof(val)))
3119                        return -EFAULT;
3120                switch (val) {
3121                case TPACKET_V1:
3122                case TPACKET_V2:
3123                case TPACKET_V3:
3124                        po->tp_version = val;
3125                        return 0;
3126                default:
3127                        return -EINVAL;
3128                }
3129        }
3130        case PACKET_RESERVE:
3131        {
3132                unsigned int val;
3133
3134                if (optlen != sizeof(val))
3135                        return -EINVAL;
3136                if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3137                        return -EBUSY;
3138                if (copy_from_user(&val, optval, sizeof(val)))
3139                        return -EFAULT;
3140                po->tp_reserve = val;
3141                return 0;
3142        }
3143        case PACKET_LOSS:
3144        {
3145                unsigned int val;
3146
3147                if (optlen != sizeof(val))
3148                        return -EINVAL;
3149                if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3150                        return -EBUSY;
3151                if (copy_from_user(&val, optval, sizeof(val)))
3152                        return -EFAULT;
3153                po->tp_loss = !!val;
3154                return 0;
3155        }
3156        case PACKET_AUXDATA:
3157        {
3158                int val;
3159
3160                if (optlen < sizeof(val))
3161                        return -EINVAL;
3162                if (copy_from_user(&val, optval, sizeof(val)))
3163                        return -EFAULT;
3164
3165                po->auxdata = !!val;
3166                return 0;
3167        }
3168        case PACKET_ORIGDEV:
3169        {
3170                int val;
3171
3172                if (optlen < sizeof(val))
3173                        return -EINVAL;
3174                if (copy_from_user(&val, optval, sizeof(val)))
3175                        return -EFAULT;
3176
3177                po->origdev = !!val;
3178                return 0;
3179        }
3180        case PACKET_VNET_HDR:
3181        {
3182                int val;
3183
3184                if (sock->type != SOCK_RAW)
3185                        return -EINVAL;
3186                if (po->rx_ring.pg_vec || po->tx_ring.pg_vec)
3187                        return -EBUSY;
3188                if (optlen < sizeof(val))
3189                        return -EINVAL;
3190                if (copy_from_user(&val, optval, sizeof(val)))
3191                        return -EFAULT;
3192
3193                po->has_vnet_hdr = !!val;
3194                return 0;
3195        }
3196        case PACKET_TIMESTAMP:
3197        {
3198                int val;
3199
3200                if (optlen != sizeof(val))
3201                        return -EINVAL;
3202                if (copy_from_user(&val, optval, sizeof(val)))
3203                        return -EFAULT;
3204
3205                po->tp_tstamp = val;
3206                return 0;
3207        }
3208        case PACKET_FANOUT:
3209        {
3210                int val;
3211
3212                if (optlen != sizeof(val))
3213                        return -EINVAL;
3214                if (copy_from_user(&val, optval, sizeof(val)))
3215                        return -EFAULT;
3216
3217                return fanout_add(sk, val & 0xffff, val >> 16);
3218        }
3219        default:
3220                return -ENOPROTOOPT;
3221        }
3222}
3223
3224static int packet_getsockopt(struct socket *sock, int level, int optname,
3225                             char __user *optval, int __user *optlen)
3226{
3227        int len;
3228        int val, lv = sizeof(val);
3229        struct sock *sk = sock->sk;
3230        struct packet_sock *po = pkt_sk(sk);
3231        void *data = &val;
3232        struct tpacket_stats st;
3233        union tpacket_stats_u st_u;
3234
3235        if (level != SOL_PACKET)
3236                return -ENOPROTOOPT;
3237
3238        if (get_user(len, optlen))
3239                return -EFAULT;
3240
3241        if (len < 0)
3242                return -EINVAL;
3243
3244        switch (optname) {
3245        case PACKET_STATISTICS:
3246                spin_lock_bh(&sk->sk_receive_queue.lock);
3247                if (po->tp_version == TPACKET_V3) {
3248                        lv = sizeof(struct tpacket_stats_v3);
3249                        memcpy(&st_u.stats3, &po->stats,
3250                               sizeof(struct tpacket_stats));
3251                        st_u.stats3.tp_freeze_q_cnt =
3252                                        po->stats_u.stats3.tp_freeze_q_cnt;
3253                        st_u.stats3.tp_packets += po->stats.tp_drops;
3254                        data = &st_u.stats3;
3255                } else {
3256                        lv = sizeof(struct tpacket_stats);
3257                        st = po->stats;
3258                        st.tp_packets += st.tp_drops;
3259                        data = &st;
3260                }
3261                memset(&po->stats, 0, sizeof(st));
3262                spin_unlock_bh(&sk->sk_receive_queue.lock);
3263                break;
3264        case PACKET_AUXDATA:
3265                val = po->auxdata;
3266                break;
3267        case PACKET_ORIGDEV:
3268                val = po->origdev;
3269                break;
3270        case PACKET_VNET_HDR:
3271                val = po->has_vnet_hdr;
3272                break;
3273        case PACKET_VERSION:
3274                val = po->tp_version;
3275                break;
3276        case PACKET_HDRLEN:
3277                if (len > sizeof(int))
3278                        len = sizeof(int);
3279                if (copy_from_user(&val, optval, len))
3280                        return -EFAULT;
3281                switch (val) {
3282                case TPACKET_V1:
3283                        val = sizeof(struct tpacket_hdr);
3284                        break;
3285                case TPACKET_V2:
3286                        val = sizeof(struct tpacket2_hdr);
3287                        break;
3288                case TPACKET_V3:
3289                        val = sizeof(struct tpacket3_hdr);
3290                        break;
3291                default:
3292                        return -EINVAL;
3293                }
3294                break;
3295        case PACKET_RESERVE:
3296                val = po->tp_reserve;
3297                break;
3298        case PACKET_LOSS:
3299                val = po->tp_loss;
3300                break;
3301        case PACKET_TIMESTAMP:
3302                val = po->tp_tstamp;
3303                break;
3304        case PACKET_FANOUT:
3305                val = (po->fanout ?
3306                       ((u32)po->fanout->id |
3307                        ((u32)po->fanout->type << 16)) :
3308                       0);
3309                break;
3310        default:
3311                return -ENOPROTOOPT;
3312        }
3313
3314        if (len > lv)
3315                len = lv;
3316        if (put_user(len, optlen))
3317                return -EFAULT;
3318        if (copy_to_user(optval, data, len))
3319                return -EFAULT;
3320        return 0;
3321}
3322
3323
3324static int packet_notifier(struct notifier_block *this, unsigned long msg, void *data)
3325{
3326        struct sock *sk;
3327        struct hlist_node *node;
3328        struct net_device *dev = data;
3329        struct net *net = dev_net(dev);
3330
3331        rcu_read_lock();
3332        sk_for_each_rcu(sk, node, &net->packet.sklist) {
3333                struct packet_sock *po = pkt_sk(sk);
3334
3335                switch (msg) {
3336                case NETDEV_UNREGISTER:
3337                        if (po->mclist)
3338                                packet_dev_mclist(dev, po->mclist, -1);
3339                        /* fallthrough */
3340
3341                case NETDEV_DOWN:
3342                        if (dev->ifindex == po->ifindex) {
3343                                spin_lock(&po->bind_lock);
3344                                if (po->running) {
3345                                        __unregister_prot_hook(sk, false);
3346                                        sk->sk_err = ENETDOWN;
3347                                        if (!sock_flag(sk, SOCK_DEAD))
3348                                                sk->sk_error_report(sk);
3349                                }
3350                                if (msg == NETDEV_UNREGISTER) {
3351                                        po->ifindex = -1;
3352                                        if (po->prot_hook.dev)
3353                                                dev_put(po->prot_hook.dev);
3354                                        po->prot_hook.dev = NULL;
3355                                }
3356                                spin_unlock(&po->bind_lock);
3357                        }
3358                        break;
3359                case NETDEV_UP:
3360                        if (dev->ifindex == po->ifindex) {
3361                                spin_lock(&po->bind_lock);
3362                                if (po->num)
3363                                        register_prot_hook(sk);
3364                                spin_unlock(&po->bind_lock);
3365                        }
3366                        break;
3367                }
3368        }
3369        rcu_read_unlock();
3370        return NOTIFY_DONE;
3371}
3372
3373
3374static int packet_ioctl(struct socket *sock, unsigned int cmd,
3375                        unsigned long arg)
3376{
3377        struct sock *sk = sock->sk;
3378
3379        switch (cmd) {
3380        case SIOCOUTQ:
3381        {
3382                int amount = sk_wmem_alloc_get(sk);
3383
3384                return put_user(amount, (int __user *)arg);
3385        }
3386        case SIOCINQ:
3387        {
3388                struct sk_buff *skb;
3389                int amount = 0;
3390
3391                spin_lock_bh(&sk->sk_receive_queue.lock);
3392                skb = skb_peek(&sk->sk_receive_queue);
3393                if (skb)
3394                        amount = skb->len;
3395                spin_unlock_bh(&sk->sk_receive_queue.lock);
3396                return put_user(amount, (int __user *)arg);
3397        }
3398        case SIOCGSTAMP:
3399                return sock_get_timestamp(sk, (struct timeval __user *)arg);
3400        case SIOCGSTAMPNS:
3401                return sock_get_timestampns(sk, (struct timespec __user *)arg);
3402
3403#ifdef CONFIG_INET
3404        case SIOCADDRT:
3405        case SIOCDELRT:
3406        case SIOCDARP:
3407        case SIOCGARP:
3408        case SIOCSARP:
3409        case SIOCGIFADDR:
3410        case SIOCSIFADDR:
3411        case SIOCGIFBRDADDR:
3412        case SIOCSIFBRDADDR:
3413        case SIOCGIFNETMASK:
3414        case SIOCSIFNETMASK:
3415        case SIOCGIFDSTADDR:
3416        case SIOCSIFDSTADDR:
3417        case SIOCSIFFLAGS:
3418                return inet_dgram_ops.ioctl(sock, cmd, arg);
3419#endif
3420
3421        default:
3422                return -ENOIOCTLCMD;
3423        }
3424        return 0;
3425}
3426
3427static unsigned int packet_poll(struct file *file, struct socket *sock,
3428                                poll_table *wait)
3429{
3430        struct sock *sk = sock->sk;
3431        struct packet_sock *po = pkt_sk(sk);
3432        unsigned int mask = datagram_poll(file, sock, wait);
3433
3434        spin_lock_bh(&sk->sk_receive_queue.lock);
3435        if (po->rx_ring.pg_vec) {
3436                if (!packet_previous_rx_frame(po, &po->rx_ring,
3437                        TP_STATUS_KERNEL))
3438                        mask |= POLLIN | POLLRDNORM;
3439        }
3440        spin_unlock_bh(&sk->sk_receive_queue.lock);
3441        spin_lock_bh(&sk->sk_write_queue.lock);
3442        if (po->tx_ring.pg_vec) {
3443                if (packet_current_frame(po, &po->tx_ring, TP_STATUS_AVAILABLE))
3444                        mask |= POLLOUT | POLLWRNORM;
3445        }
3446        spin_unlock_bh(&sk->sk_write_queue.lock);
3447        return mask;
3448}
3449
3450
3451/* Dirty? Well, I still did not learn better way to account
3452 * for user mmaps.
3453 */
3454
3455static void packet_mm_open(struct vm_area_struct *vma)
3456{
3457        struct file *file = vma->vm_file;
3458        struct socket *sock = file->private_data;
3459        struct sock *sk = sock->sk;
3460
3461        if (sk)
3462                atomic_inc(&pkt_sk(sk)->mapped);
3463}
3464
3465static void packet_mm_close(struct vm_area_struct *vma)
3466{
3467        struct file *file = vma->vm_file;
3468        struct socket *sock = file->private_data;
3469        struct sock *sk = sock->sk;
3470
3471        if (sk)
3472                atomic_dec(&pkt_sk(sk)->mapped);
3473}
3474
3475static const struct vm_operations_struct packet_mmap_ops = {
3476        .open   =       packet_mm_open,
3477        .close  =       packet_mm_close,
3478};
3479
3480static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
3481                        unsigned int len)
3482{
3483        int i;
3484
3485        for (i = 0; i < len; i++) {
3486                if (likely(pg_vec[i].buffer)) {
3487                        if (is_vmalloc_addr(pg_vec[i].buffer))
3488                                vfree(pg_vec[i].buffer);
3489                        else
3490                                free_pages((unsigned long)pg_vec[i].buffer,
3491                                           order);
3492                        pg_vec[i].buffer = NULL;
3493                }
3494        }
3495        kfree(pg_vec);
3496}
3497
3498static char *alloc_one_pg_vec_page(unsigned long order)
3499{
3500        char *buffer = NULL;
3501        gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
3502                          __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
3503
3504        buffer = (char *) __get_free_pages(gfp_flags, order);
3505
3506        if (buffer)
3507                return buffer;
3508
3509        /*
3510         * __get_free_pages failed, fall back to vmalloc
3511         */
3512        buffer = vzalloc((1 << order) * PAGE_SIZE);
3513
3514        if (buffer)
3515                return buffer;
3516
3517        /*
3518         * vmalloc failed, lets dig into swap here
3519         */
3520        gfp_flags &= ~__GFP_NORETRY;
3521        buffer = (char *)__get_free_pages(gfp_flags, order);
3522        if (buffer)
3523                return buffer;
3524
3525        /*
3526         * complete and utter failure
3527         */
3528        return NULL;
3529}
3530
3531static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
3532{
3533        unsigned int block_nr = req->tp_block_nr;
3534        struct pgv *pg_vec;
3535        int i;
3536
3537        pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
3538        if (unlikely(!pg_vec))
3539                goto out;
3540
3541        for (i = 0; i < block_nr; i++) {
3542                pg_vec[i].buffer = alloc_one_pg_vec_page(order);
3543                if (unlikely(!pg_vec[i].buffer))
3544                        goto out_free_pgvec;
3545        }
3546
3547out:
3548        return pg_vec;
3549
3550out_free_pgvec:
3551        free_pg_vec(pg_vec, order, block_nr);
3552        pg_vec = NULL;
3553        goto out;
3554}
3555
3556static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
3557                int closing, int tx_ring)
3558{
3559        struct pgv *pg_vec = NULL;
3560        struct packet_sock *po = pkt_sk(sk);
3561        int was_running, order = 0;
3562        struct packet_ring_buffer *rb;
3563        struct sk_buff_head *rb_queue;
3564        __be16 num;
3565        int err = -EINVAL;
3566        /* Added to avoid minimal code churn */
3567        struct tpacket_req *req = &req_u->req;
3568
3569        /* Opening a Tx-ring is NOT supported in TPACKET_V3 */
3570        if (!closing && tx_ring && (po->tp_version > TPACKET_V2)) {
3571                WARN(1, "Tx-ring is not supported.\n");
3572                goto out;
3573        }
3574
3575        rb = tx_ring ? &po->tx_ring : &po->rx_ring;
3576        rb_queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
3577
3578        err = -EBUSY;
3579        if (!closing) {
3580                if (atomic_read(&po->mapped))
3581                        goto out;
3582                if (atomic_read(&rb->pending))
3583                        goto out;
3584        }
3585
3586        if (req->tp_block_nr) {
3587                /* Sanity tests and some calculations */
3588                err = -EBUSY;
3589                if (unlikely(rb->pg_vec))
3590                        goto out;
3591
3592                switch (po->tp_version) {
3593                case TPACKET_V1:
3594                        po->tp_hdrlen = TPACKET_HDRLEN;
3595                        break;
3596                case TPACKET_V2:
3597                        po->tp_hdrlen = TPACKET2_HDRLEN;
3598                        break;
3599                case TPACKET_V3:
3600                        po->tp_hdrlen = TPACKET3_HDRLEN;
3601                        break;
3602                }
3603
3604                err = -EINVAL;
3605                if (unlikely((int)req->tp_block_size <= 0))
3606                        goto out;
3607                if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
3608                        goto out;
3609                if (unlikely(req->tp_frame_size < po->tp_hdrlen +
3610                                        po->tp_reserve))
3611                        goto out;
3612                if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
3613                        goto out;
3614
3615                rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
3616                if (unlikely(rb->frames_per_block <= 0))
3617                        goto out;
3618                if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
3619                                        req->tp_frame_nr))
3620                        goto out;
3621
3622                err = -ENOMEM;
3623                order = get_order(req->tp_block_size);
3624                pg_vec = alloc_pg_vec(req, order);
3625                if (unlikely(!pg_vec))
3626                        goto out;
3627                switch (po->tp_version) {
3628                case TPACKET_V3:
3629                /* Transmit path is not supported. We checked
3630                 * it above but just being paranoid
3631                 */
3632                        if (!tx_ring)
3633                                init_prb_bdqc(po, rb, pg_vec, req_u, tx_ring);
3634                                break;
3635                default:
3636                        break;
3637                }
3638        }
3639        /* Done */
3640        else {
3641                err = -EINVAL;
3642                if (unlikely(req->tp_frame_nr))
3643                        goto out;
3644        }
3645
3646        lock_sock(sk);
3647
3648        /* Detach socket from network */
3649        spin_lock(&po->bind_lock);
3650        was_running = po->running;
3651        num = po->num;
3652        if (was_running) {
3653                po->num = 0;
3654                __unregister_prot_hook(sk, false);
3655        }
3656        spin_unlock(&po->bind_lock);
3657
3658        synchronize_net();
3659
3660        err = -EBUSY;
3661        mutex_lock(&po->pg_vec_lock);
3662        if (closing || atomic_read(&po->mapped) == 0) {
3663                err = 0;
3664                spin_lock_bh(&rb_queue->lock);
3665                swap(rb->pg_vec, pg_vec);
3666                rb->frame_max = (req->tp_frame_nr - 1);
3667                rb->head = 0;
3668                rb->frame_size = req->tp_frame_size;
3669                spin_unlock_bh(&rb_queue->lock);
3670
3671                swap(rb->pg_vec_order, order);
3672                swap(rb->pg_vec_len, req->tp_block_nr);
3673
3674                rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
3675                po->prot_hook.func = (po->rx_ring.pg_vec) ?
3676                                                tpacket_rcv : packet_rcv;
3677                skb_queue_purge(rb_queue);
3678                if (atomic_read(&po->mapped))
3679                        pr_err("packet_mmap: vma is busy: %d\n",
3680                               atomic_read(&po->mapped));
3681        }
3682        mutex_unlock(&po->pg_vec_lock);
3683
3684        spin_lock(&po->bind_lock);
3685        if (was_running) {
3686                po->num = num;
3687                register_prot_hook(sk);
3688        }
3689        spin_unlock(&po->bind_lock);
3690        if (closing && (po->tp_version > TPACKET_V2)) {
3691                /* Because we don't support block-based V3 on tx-ring */
3692                if (!tx_ring)
3693                        prb_shutdown_retire_blk_timer(po, tx_ring, rb_queue);
3694        }
3695        release_sock(sk);
3696
3697        if (pg_vec)
3698                free_pg_vec(pg_vec, order, req->tp_block_nr);
3699out:
3700        return err;
3701}
3702
3703static int packet_mmap(struct file *file, struct socket *sock,
3704                struct vm_area_struct *vma)
3705{
3706        struct sock *sk = sock->sk;
3707        struct packet_sock *po = pkt_sk(sk);
3708        unsigned long size, expected_size;
3709        struct packet_ring_buffer *rb;
3710        unsigned long start;
3711        int err = -EINVAL;
3712        int i;
3713
3714        if (vma->vm_pgoff)
3715                return -EINVAL;
3716
3717        mutex_lock(&po->pg_vec_lock);
3718
3719        expected_size = 0;
3720        for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3721                if (rb->pg_vec) {
3722                        expected_size += rb->pg_vec_len
3723                                                * rb->pg_vec_pages
3724                                                * PAGE_SIZE;
3725                }
3726        }
3727
3728        if (expected_size == 0)
3729                goto out;
3730
3731        size = vma->vm_end - vma->vm_start;
3732        if (size != expected_size)
3733                goto out;
3734
3735        start = vma->vm_start;
3736        for (rb = &po->rx_ring; rb <= &po->tx_ring; rb++) {
3737                if (rb->pg_vec == NULL)
3738                        continue;
3739
3740                for (i = 0; i < rb->pg_vec_len; i++) {
3741                        struct page *page;
3742                        void *kaddr = rb->pg_vec[i].buffer;
3743                        int pg_num;
3744
3745                        for (pg_num = 0; pg_num < rb->pg_vec_pages; pg_num++) {
3746                                page = pgv_to_page(kaddr);
3747                                err = vm_insert_page(vma, start, page);
3748                                if (unlikely(err))
3749                                        goto out;
3750                                start += PAGE_SIZE;
3751                                kaddr += PAGE_SIZE;
3752                        }
3753                }
3754        }
3755
3756        atomic_inc(&po->mapped);
3757        vma->vm_ops = &packet_mmap_ops;
3758        err = 0;
3759
3760out:
3761        mutex_unlock(&po->pg_vec_lock);
3762        return err;
3763}
3764
3765static const struct proto_ops packet_ops_spkt = {
3766        .family =       PF_PACKET,
3767        .owner =        THIS_MODULE,
3768        .release =      packet_release,
3769        .bind =         packet_bind_spkt,
3770        .connect =      sock_no_connect,
3771        .socketpair =   sock_no_socketpair,
3772        .accept =       sock_no_accept,
3773        .getname =      packet_getname_spkt,
3774        .poll =         datagram_poll,
3775        .ioctl =        packet_ioctl,
3776        .listen =       sock_no_listen,
3777        .shutdown =     sock_no_shutdown,
3778        .setsockopt =   sock_no_setsockopt,
3779        .getsockopt =   sock_no_getsockopt,
3780        .sendmsg =      packet_sendmsg_spkt,
3781        .recvmsg =      packet_recvmsg,
3782        .mmap =         sock_no_mmap,
3783        .sendpage =     sock_no_sendpage,
3784};
3785
3786static const struct proto_ops packet_ops = {
3787        .family =       PF_PACKET,
3788        .owner =        THIS_MODULE,
3789        .release =      packet_release,
3790        .bind =         packet_bind,
3791        .connect =      sock_no_connect,
3792        .socketpair =   sock_no_socketpair,
3793        .accept =       sock_no_accept,
3794        .getname =      packet_getname,
3795        .poll =         packet_poll,
3796        .ioctl =        packet_ioctl,
3797        .listen =       sock_no_listen,
3798        .shutdown =     sock_no_shutdown,
3799        .setsockopt =   packet_setsockopt,
3800        .getsockopt =   packet_getsockopt,
3801        .sendmsg =      packet_sendmsg,
3802        .recvmsg =      packet_recvmsg,
3803        .mmap =         packet_mmap,
3804        .sendpage =     sock_no_sendpage,
3805};
3806
3807static const struct net_proto_family packet_family_ops = {
3808        .family =       PF_PACKET,
3809        .create =       packet_create,
3810        .owner  =       THIS_MODULE,
3811};
3812
3813static struct notifier_block packet_netdev_notifier = {
3814        .notifier_call =        packet_notifier,
3815};
3816
3817#ifdef CONFIG_PROC_FS
3818
3819static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
3820        __acquires(RCU)
3821{
3822        struct net *net = seq_file_net(seq);
3823
3824        rcu_read_lock();
3825        return seq_hlist_start_head_rcu(&net->packet.sklist, *pos);
3826}
3827
3828static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3829{
3830        struct net *net = seq_file_net(seq);
3831        return seq_hlist_next_rcu(v, &net->packet.sklist, pos);
3832}
3833
3834static void packet_seq_stop(struct seq_file *seq, void *v)
3835        __releases(RCU)
3836{
3837        rcu_read_unlock();
3838}
3839
3840static int packet_seq_show(struct seq_file *seq, void *v)
3841{
3842        if (v == SEQ_START_TOKEN)
3843                seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
3844        else {
3845                struct sock *s = sk_entry(v);
3846                const struct packet_sock *po = pkt_sk(s);
3847
3848                seq_printf(seq,
3849                           "%pK %-6d %-4d %04x   %-5d %1d %-6u %-6u %-6lu\n",
3850                           s,
3851                           atomic_read(&s->sk_refcnt),
3852                           s->sk_type,
3853                           ntohs(po->num),
3854                           po->ifindex,
3855                           po->running,
3856                           atomic_read(&s->sk_rmem_alloc),
3857                           sock_i_uid(s),
3858                           sock_i_ino(s));
3859        }
3860
3861        return 0;
3862}
3863
3864static const struct seq_operations packet_seq_ops = {
3865        .start  = packet_seq_start,
3866        .next   = packet_seq_next,
3867        .stop   = packet_seq_stop,
3868        .show   = packet_seq_show,
3869};
3870
3871static int packet_seq_open(struct inode *inode, struct file *file)
3872{
3873        return seq_open_net(inode, file, &packet_seq_ops,
3874                            sizeof(struct seq_net_private));
3875}
3876
3877static const struct file_operations packet_seq_fops = {
3878        .owner          = THIS_MODULE,
3879        .open           = packet_seq_open,
3880        .read           = seq_read,
3881        .llseek         = seq_lseek,
3882        .release        = seq_release_net,
3883};
3884
3885#endif
3886
3887static int __net_init packet_net_init(struct net *net)
3888{
3889        spin_lock_init(&net->packet.sklist_lock);
3890        INIT_HLIST_HEAD(&net->packet.sklist);
3891
3892        if (!proc_net_fops_create(net, "packet", 0, &packet_seq_fops))
3893                return -ENOMEM;
3894
3895        return 0;
3896}
3897
3898static void __net_exit packet_net_exit(struct net *net)
3899{
3900        proc_net_remove(net, "packet");
3901}
3902
3903static struct pernet_operations packet_net_ops = {
3904        .init = packet_net_init,
3905        .exit = packet_net_exit,
3906};
3907
3908
3909static void __exit packet_exit(void)
3910{
3911        unregister_netdevice_notifier(&packet_netdev_notifier);
3912        unregister_pernet_subsys(&packet_net_ops);
3913        sock_unregister(PF_PACKET);
3914        proto_unregister(&packet_proto);
3915}
3916
3917static int __init packet_init(void)
3918{
3919        int rc = proto_register(&packet_proto, 0);
3920
3921        if (rc != 0)
3922                goto out;
3923
3924        sock_register(&packet_family_ops);
3925        register_pernet_subsys(&packet_net_ops);
3926        register_netdevice_notifier(&packet_netdev_notifier);
3927out:
3928        return rc;
3929}
3930
3931module_init(packet_init);
3932module_exit(packet_exit);
3933MODULE_LICENSE("GPL");
3934MODULE_ALIAS_NETPROTO(PF_PACKET);
3935
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