linux/net/ipv4/ping.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 *              "Ping" sockets
   7 *
   8 *              This program is free software; you can redistribute it and/or
   9 *              modify it under the terms of the GNU General Public License
  10 *              as published by the Free Software Foundation; either version
  11 *              2 of the License, or (at your option) any later version.
  12 *
  13 * Based on ipv4/udp.c code.
  14 *
  15 * Authors:     Vasiliy Kulikov / Openwall (for Linux 2.6),
  16 *              Pavel Kankovsky (for Linux 2.4.32)
  17 *
  18 * Pavel gave all rights to bugs to Vasiliy,
  19 * none of the bugs are Pavel's now.
  20 *
  21 */
  22
  23#include <asm/system.h>
  24#include <linux/uaccess.h>
  25#include <linux/types.h>
  26#include <linux/fcntl.h>
  27#include <linux/socket.h>
  28#include <linux/sockios.h>
  29#include <linux/in.h>
  30#include <linux/errno.h>
  31#include <linux/timer.h>
  32#include <linux/mm.h>
  33#include <linux/inet.h>
  34#include <linux/netdevice.h>
  35#include <net/snmp.h>
  36#include <net/ip.h>
  37#include <net/ipv6.h>
  38#include <net/icmp.h>
  39#include <net/protocol.h>
  40#include <linux/skbuff.h>
  41#include <linux/proc_fs.h>
  42#include <linux/export.h>
  43#include <net/sock.h>
  44#include <net/ping.h>
  45#include <net/udp.h>
  46#include <net/route.h>
  47#include <net/inet_common.h>
  48#include <net/checksum.h>
  49
  50
  51static struct ping_table ping_table;
  52
  53static u16 ping_port_rover;
  54
  55static inline int ping_hashfn(struct net *net, unsigned num, unsigned mask)
  56{
  57        int res = (num + net_hash_mix(net)) & mask;
  58        pr_debug("hash(%d) = %d\n", num, res);
  59        return res;
  60}
  61
  62static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
  63                                             struct net *net, unsigned num)
  64{
  65        return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
  66}
  67
  68static int ping_v4_get_port(struct sock *sk, unsigned short ident)
  69{
  70        struct hlist_nulls_node *node;
  71        struct hlist_nulls_head *hlist;
  72        struct inet_sock *isk, *isk2;
  73        struct sock *sk2 = NULL;
  74
  75        isk = inet_sk(sk);
  76        write_lock_bh(&ping_table.lock);
  77        if (ident == 0) {
  78                u32 i;
  79                u16 result = ping_port_rover + 1;
  80
  81                for (i = 0; i < (1L << 16); i++, result++) {
  82                        if (!result)
  83                                result++; /* avoid zero */
  84                        hlist = ping_hashslot(&ping_table, sock_net(sk),
  85                                            result);
  86                        ping_portaddr_for_each_entry(sk2, node, hlist) {
  87                                isk2 = inet_sk(sk2);
  88
  89                                if (isk2->inet_num == result)
  90                                        goto next_port;
  91                        }
  92
  93                        /* found */
  94                        ping_port_rover = ident = result;
  95                        break;
  96next_port:
  97                        ;
  98                }
  99                if (i >= (1L << 16))
 100                        goto fail;
 101        } else {
 102                hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
 103                ping_portaddr_for_each_entry(sk2, node, hlist) {
 104                        isk2 = inet_sk(sk2);
 105
 106                        if ((isk2->inet_num == ident) &&
 107                            (sk2 != sk) &&
 108                            (!sk2->sk_reuse || !sk->sk_reuse))
 109                                goto fail;
 110                }
 111        }
 112
 113        pr_debug("found port/ident = %d\n", ident);
 114        isk->inet_num = ident;
 115        if (sk_unhashed(sk)) {
 116                pr_debug("was not hashed\n");
 117                sock_hold(sk);
 118                hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
 119                sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 120        }
 121        write_unlock_bh(&ping_table.lock);
 122        return 0;
 123
 124fail:
 125        write_unlock_bh(&ping_table.lock);
 126        return 1;
 127}
 128
 129static void ping_v4_hash(struct sock *sk)
 130{
 131        pr_debug("ping_v4_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
 132        BUG(); /* "Please do not press this button again." */
 133}
 134
 135static void ping_v4_unhash(struct sock *sk)
 136{
 137        struct inet_sock *isk = inet_sk(sk);
 138        pr_debug("ping_v4_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
 139        if (sk_hashed(sk)) {
 140                write_lock_bh(&ping_table.lock);
 141                hlist_nulls_del(&sk->sk_nulls_node);
 142                sock_put(sk);
 143                isk->inet_num = 0;
 144                isk->inet_sport = 0;
 145                sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
 146                write_unlock_bh(&ping_table.lock);
 147        }
 148}
 149
 150static struct sock *ping_v4_lookup(struct net *net, __be32 saddr, __be32 daddr,
 151                                   u16 ident, int dif)
 152{
 153        struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
 154        struct sock *sk = NULL;
 155        struct inet_sock *isk;
 156        struct hlist_nulls_node *hnode;
 157
 158        pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
 159                         (int)ident, &daddr, dif);
 160        read_lock_bh(&ping_table.lock);
 161
 162        ping_portaddr_for_each_entry(sk, hnode, hslot) {
 163                isk = inet_sk(sk);
 164
 165                pr_debug("found: %p: num = %d, daddr = %pI4, dif = %d\n", sk,
 166                         (int)isk->inet_num, &isk->inet_rcv_saddr,
 167                         sk->sk_bound_dev_if);
 168
 169                pr_debug("iterate\n");
 170                if (isk->inet_num != ident)
 171                        continue;
 172                if (isk->inet_rcv_saddr && isk->inet_rcv_saddr != daddr)
 173                        continue;
 174                if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
 175                        continue;
 176
 177                sock_hold(sk);
 178                goto exit;
 179        }
 180
 181        sk = NULL;
 182exit:
 183        read_unlock_bh(&ping_table.lock);
 184
 185        return sk;
 186}
 187
 188static void inet_get_ping_group_range_net(struct net *net, gid_t *low,
 189                                          gid_t *high)
 190{
 191        gid_t *data = net->ipv4.sysctl_ping_group_range;
 192        unsigned seq;
 193        do {
 194                seq = read_seqbegin(&sysctl_local_ports.lock);
 195
 196                *low = data[0];
 197                *high = data[1];
 198        } while (read_seqretry(&sysctl_local_ports.lock, seq));
 199}
 200
 201
 202static int ping_init_sock(struct sock *sk)
 203{
 204        struct net *net = sock_net(sk);
 205        gid_t group = current_egid();
 206        gid_t range[2];
 207        struct group_info *group_info = get_current_groups();
 208        int i, j, count = group_info->ngroups;
 209
 210        inet_get_ping_group_range_net(net, range, range+1);
 211        if (range[0] <= group && group <= range[1])
 212                return 0;
 213
 214        for (i = 0; i < group_info->nblocks; i++) {
 215                int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
 216
 217                for (j = 0; j < cp_count; j++) {
 218                        group = group_info->blocks[i][j];
 219                        if (range[0] <= group && group <= range[1])
 220                                return 0;
 221                }
 222
 223                count -= cp_count;
 224        }
 225
 226        return -EACCES;
 227}
 228
 229static void ping_close(struct sock *sk, long timeout)
 230{
 231        pr_debug("ping_close(sk=%p,sk->num=%u)\n",
 232                inet_sk(sk), inet_sk(sk)->inet_num);
 233        pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
 234
 235        sk_common_release(sk);
 236}
 237
 238/*
 239 * We need our own bind because there are no privileged id's == local ports.
 240 * Moreover, we don't allow binding to multi- and broadcast addresses.
 241 */
 242
 243static int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 244{
 245        struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
 246        struct inet_sock *isk = inet_sk(sk);
 247        unsigned short snum;
 248        int chk_addr_ret;
 249        int err;
 250
 251        if (addr_len < sizeof(struct sockaddr_in))
 252                return -EINVAL;
 253
 254        pr_debug("ping_v4_bind(sk=%p,sa_addr=%08x,sa_port=%d)\n",
 255                sk, addr->sin_addr.s_addr, ntohs(addr->sin_port));
 256
 257        chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
 258        if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
 259                chk_addr_ret = RTN_LOCAL;
 260
 261        if ((sysctl_ip_nonlocal_bind == 0 &&
 262            isk->freebind == 0 && isk->transparent == 0 &&
 263             chk_addr_ret != RTN_LOCAL) ||
 264            chk_addr_ret == RTN_MULTICAST ||
 265            chk_addr_ret == RTN_BROADCAST)
 266                return -EADDRNOTAVAIL;
 267
 268        lock_sock(sk);
 269
 270        err = -EINVAL;
 271        if (isk->inet_num != 0)
 272                goto out;
 273
 274        err = -EADDRINUSE;
 275        isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
 276        snum = ntohs(addr->sin_port);
 277        if (ping_v4_get_port(sk, snum) != 0) {
 278                isk->inet_saddr = isk->inet_rcv_saddr = 0;
 279                goto out;
 280        }
 281
 282        pr_debug("after bind(): num = %d, daddr = %pI4, dif = %d\n",
 283                (int)isk->inet_num,
 284                &isk->inet_rcv_saddr,
 285                (int)sk->sk_bound_dev_if);
 286
 287        err = 0;
 288        if (isk->inet_rcv_saddr)
 289                sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
 290        if (snum)
 291                sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
 292        isk->inet_sport = htons(isk->inet_num);
 293        isk->inet_daddr = 0;
 294        isk->inet_dport = 0;
 295        sk_dst_reset(sk);
 296out:
 297        release_sock(sk);
 298        pr_debug("ping_v4_bind -> %d\n", err);
 299        return err;
 300}
 301
 302/*
 303 * Is this a supported type of ICMP message?
 304 */
 305
 306static inline int ping_supported(int type, int code)
 307{
 308        if (type == ICMP_ECHO && code == 0)
 309                return 1;
 310        return 0;
 311}
 312
 313/*
 314 * This routine is called by the ICMP module when it gets some
 315 * sort of error condition.
 316 */
 317
 318static int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 319
 320void ping_err(struct sk_buff *skb, u32 info)
 321{
 322        struct iphdr *iph = (struct iphdr *)skb->data;
 323        struct icmphdr *icmph = (struct icmphdr *)(skb->data+(iph->ihl<<2));
 324        struct inet_sock *inet_sock;
 325        int type = icmph->type;
 326        int code = icmph->code;
 327        struct net *net = dev_net(skb->dev);
 328        struct sock *sk;
 329        int harderr;
 330        int err;
 331
 332        /* We assume the packet has already been checked by icmp_unreach */
 333
 334        if (!ping_supported(icmph->type, icmph->code))
 335                return;
 336
 337        pr_debug("ping_err(type=%04x,code=%04x,id=%04x,seq=%04x)\n", type,
 338                code, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
 339
 340        sk = ping_v4_lookup(net, iph->daddr, iph->saddr,
 341                            ntohs(icmph->un.echo.id), skb->dev->ifindex);
 342        if (sk == NULL) {
 343                pr_debug("no socket, dropping\n");
 344                return; /* No socket for error */
 345        }
 346        pr_debug("err on socket %p\n", sk);
 347
 348        err = 0;
 349        harderr = 0;
 350        inet_sock = inet_sk(sk);
 351
 352        switch (type) {
 353        default:
 354        case ICMP_TIME_EXCEEDED:
 355                err = EHOSTUNREACH;
 356                break;
 357        case ICMP_SOURCE_QUENCH:
 358                /* This is not a real error but ping wants to see it.
 359                 * Report it with some fake errno. */
 360                err = EREMOTEIO;
 361                break;
 362        case ICMP_PARAMETERPROB:
 363                err = EPROTO;
 364                harderr = 1;
 365                break;
 366        case ICMP_DEST_UNREACH:
 367                if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
 368                        if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
 369                                err = EMSGSIZE;
 370                                harderr = 1;
 371                                break;
 372                        }
 373                        goto out;
 374                }
 375                err = EHOSTUNREACH;
 376                if (code <= NR_ICMP_UNREACH) {
 377                        harderr = icmp_err_convert[code].fatal;
 378                        err = icmp_err_convert[code].errno;
 379                }
 380                break;
 381        case ICMP_REDIRECT:
 382                /* See ICMP_SOURCE_QUENCH */
 383                err = EREMOTEIO;
 384                break;
 385        }
 386
 387        /*
 388         *      RFC1122: OK.  Passes ICMP errors back to application, as per
 389         *      4.1.3.3.
 390         */
 391        if (!inet_sock->recverr) {
 392                if (!harderr || sk->sk_state != TCP_ESTABLISHED)
 393                        goto out;
 394        } else {
 395                ip_icmp_error(sk, skb, err, 0 /* no remote port */,
 396                         info, (u8 *)icmph);
 397        }
 398        sk->sk_err = err;
 399        sk->sk_error_report(sk);
 400out:
 401        sock_put(sk);
 402}
 403
 404/*
 405 *      Copy and checksum an ICMP Echo packet from user space into a buffer.
 406 */
 407
 408struct pingfakehdr {
 409        struct icmphdr icmph;
 410        struct iovec *iov;
 411        __wsum wcheck;
 412};
 413
 414static int ping_getfrag(void *from, char * to,
 415                        int offset, int fraglen, int odd, struct sk_buff *skb)
 416{
 417        struct pingfakehdr *pfh = (struct pingfakehdr *)from;
 418
 419        if (offset == 0) {
 420                if (fraglen < sizeof(struct icmphdr))
 421                        BUG();
 422                if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
 423                            pfh->iov, 0, fraglen - sizeof(struct icmphdr),
 424                            &pfh->wcheck))
 425                        return -EFAULT;
 426
 427                return 0;
 428        }
 429        if (offset < sizeof(struct icmphdr))
 430                BUG();
 431        if (csum_partial_copy_fromiovecend
 432                        (to, pfh->iov, offset - sizeof(struct icmphdr),
 433                         fraglen, &pfh->wcheck))
 434                return -EFAULT;
 435        return 0;
 436}
 437
 438static int ping_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
 439                                    struct flowi4 *fl4)
 440{
 441        struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
 442
 443        pfh->wcheck = csum_partial((char *)&pfh->icmph,
 444                sizeof(struct icmphdr), pfh->wcheck);
 445        pfh->icmph.checksum = csum_fold(pfh->wcheck);
 446        memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
 447        skb->ip_summed = CHECKSUM_NONE;
 448        return ip_push_pending_frames(sk, fl4);
 449}
 450
 451static int ping_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 452                        size_t len)
 453{
 454        struct net *net = sock_net(sk);
 455        struct flowi4 fl4;
 456        struct inet_sock *inet = inet_sk(sk);
 457        struct ipcm_cookie ipc;
 458        struct icmphdr user_icmph;
 459        struct pingfakehdr pfh;
 460        struct rtable *rt = NULL;
 461        struct ip_options_data opt_copy;
 462        int free = 0;
 463        __be32 saddr, daddr, faddr;
 464        u8  tos;
 465        int err;
 466
 467        pr_debug("ping_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
 468
 469
 470        if (len > 0xFFFF)
 471                return -EMSGSIZE;
 472
 473        /*
 474         *      Check the flags.
 475         */
 476
 477        /* Mirror BSD error message compatibility */
 478        if (msg->msg_flags & MSG_OOB)
 479                return -EOPNOTSUPP;
 480
 481        /*
 482         *      Fetch the ICMP header provided by the userland.
 483         *      iovec is modified!
 484         */
 485
 486        if (memcpy_fromiovec((u8 *)&user_icmph, msg->msg_iov,
 487                             sizeof(struct icmphdr)))
 488                return -EFAULT;
 489        if (!ping_supported(user_icmph.type, user_icmph.code))
 490                return -EINVAL;
 491
 492        /*
 493         *      Get and verify the address.
 494         */
 495
 496        if (msg->msg_name) {
 497                struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
 498                if (msg->msg_namelen < sizeof(*usin))
 499                        return -EINVAL;
 500                if (usin->sin_family != AF_INET)
 501                        return -EINVAL;
 502                daddr = usin->sin_addr.s_addr;
 503                /* no remote port */
 504        } else {
 505                if (sk->sk_state != TCP_ESTABLISHED)
 506                        return -EDESTADDRREQ;
 507                daddr = inet->inet_daddr;
 508                /* no remote port */
 509        }
 510
 511        ipc.addr = inet->inet_saddr;
 512        ipc.opt = NULL;
 513        ipc.oif = sk->sk_bound_dev_if;
 514        ipc.tx_flags = 0;
 515        err = sock_tx_timestamp(sk, &ipc.tx_flags);
 516        if (err)
 517                return err;
 518
 519        if (msg->msg_controllen) {
 520                err = ip_cmsg_send(sock_net(sk), msg, &ipc);
 521                if (err)
 522                        return err;
 523                if (ipc.opt)
 524                        free = 1;
 525        }
 526        if (!ipc.opt) {
 527                struct ip_options_rcu *inet_opt;
 528
 529                rcu_read_lock();
 530                inet_opt = rcu_dereference(inet->inet_opt);
 531                if (inet_opt) {
 532                        memcpy(&opt_copy, inet_opt,
 533                               sizeof(*inet_opt) + inet_opt->opt.optlen);
 534                        ipc.opt = &opt_copy.opt;
 535                }
 536                rcu_read_unlock();
 537        }
 538
 539        saddr = ipc.addr;
 540        ipc.addr = faddr = daddr;
 541
 542        if (ipc.opt && ipc.opt->opt.srr) {
 543                if (!daddr)
 544                        return -EINVAL;
 545                faddr = ipc.opt->opt.faddr;
 546        }
 547        tos = RT_TOS(inet->tos);
 548        if (sock_flag(sk, SOCK_LOCALROUTE) ||
 549            (msg->msg_flags & MSG_DONTROUTE) ||
 550            (ipc.opt && ipc.opt->opt.is_strictroute)) {
 551                tos |= RTO_ONLINK;
 552        }
 553
 554        if (ipv4_is_multicast(daddr)) {
 555                if (!ipc.oif)
 556                        ipc.oif = inet->mc_index;
 557                if (!saddr)
 558                        saddr = inet->mc_addr;
 559        }
 560
 561        flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
 562                           RT_SCOPE_UNIVERSE, sk->sk_protocol,
 563                           inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
 564
 565        security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
 566        rt = ip_route_output_flow(net, &fl4, sk);
 567        if (IS_ERR(rt)) {
 568                err = PTR_ERR(rt);
 569                rt = NULL;
 570                if (err == -ENETUNREACH)
 571                        IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
 572                goto out;
 573        }
 574
 575        err = -EACCES;
 576        if ((rt->rt_flags & RTCF_BROADCAST) &&
 577            !sock_flag(sk, SOCK_BROADCAST))
 578                goto out;
 579
 580        if (msg->msg_flags & MSG_CONFIRM)
 581                goto do_confirm;
 582back_from_confirm:
 583
 584        if (!ipc.addr)
 585                ipc.addr = fl4.daddr;
 586
 587        lock_sock(sk);
 588
 589        pfh.icmph.type = user_icmph.type; /* already checked */
 590        pfh.icmph.code = user_icmph.code; /* ditto */
 591        pfh.icmph.checksum = 0;
 592        pfh.icmph.un.echo.id = inet->inet_sport;
 593        pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
 594        pfh.iov = msg->msg_iov;
 595        pfh.wcheck = 0;
 596
 597        err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
 598                        0, &ipc, &rt, msg->msg_flags);
 599        if (err)
 600                ip_flush_pending_frames(sk);
 601        else
 602                err = ping_push_pending_frames(sk, &pfh, &fl4);
 603        release_sock(sk);
 604
 605out:
 606        ip_rt_put(rt);
 607        if (free)
 608                kfree(ipc.opt);
 609        if (!err) {
 610                icmp_out_count(sock_net(sk), user_icmph.type);
 611                return len;
 612        }
 613        return err;
 614
 615do_confirm:
 616        dst_confirm(&rt->dst);
 617        if (!(msg->msg_flags & MSG_PROBE) || len)
 618                goto back_from_confirm;
 619        err = 0;
 620        goto out;
 621}
 622
 623static int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 624                        size_t len, int noblock, int flags, int *addr_len)
 625{
 626        struct inet_sock *isk = inet_sk(sk);
 627        struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
 628        struct sk_buff *skb;
 629        int copied, err;
 630
 631        pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
 632
 633        err = -EOPNOTSUPP;
 634        if (flags & MSG_OOB)
 635                goto out;
 636
 637        if (addr_len)
 638                *addr_len = sizeof(*sin);
 639
 640        if (flags & MSG_ERRQUEUE)
 641                return ip_recv_error(sk, msg, len);
 642
 643        skb = skb_recv_datagram(sk, flags, noblock, &err);
 644        if (!skb)
 645                goto out;
 646
 647        copied = skb->len;
 648        if (copied > len) {
 649                msg->msg_flags |= MSG_TRUNC;
 650                copied = len;
 651        }
 652
 653        /* Don't bother checking the checksum */
 654        err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 655        if (err)
 656                goto done;
 657
 658        sock_recv_timestamp(msg, sk, skb);
 659
 660        /* Copy the address. */
 661        if (sin) {
 662                sin->sin_family = AF_INET;
 663                sin->sin_port = 0 /* skb->h.uh->source */;
 664                sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 665                memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 666        }
 667        if (isk->cmsg_flags)
 668                ip_cmsg_recv(msg, skb);
 669        err = copied;
 670
 671done:
 672        skb_free_datagram(sk, skb);
 673out:
 674        pr_debug("ping_recvmsg -> %d\n", err);
 675        return err;
 676}
 677
 678static int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 679{
 680        pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
 681                inet_sk(sk), inet_sk(sk)->inet_num, skb);
 682        if (sock_queue_rcv_skb(sk, skb) < 0) {
 683                kfree_skb(skb);
 684                pr_debug("ping_queue_rcv_skb -> failed\n");
 685                return -1;
 686        }
 687        return 0;
 688}
 689
 690
 691/*
 692 *      All we need to do is get the socket.
 693 */
 694
 695void ping_rcv(struct sk_buff *skb)
 696{
 697        struct sock *sk;
 698        struct net *net = dev_net(skb->dev);
 699        struct iphdr *iph = ip_hdr(skb);
 700        struct icmphdr *icmph = icmp_hdr(skb);
 701        __be32 saddr = iph->saddr;
 702        __be32 daddr = iph->daddr;
 703
 704        /* We assume the packet has already been checked by icmp_rcv */
 705
 706        pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
 707                skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
 708
 709        /* Push ICMP header back */
 710        skb_push(skb, skb->data - (u8 *)icmph);
 711
 712        sk = ping_v4_lookup(net, saddr, daddr, ntohs(icmph->un.echo.id),
 713                            skb->dev->ifindex);
 714        if (sk != NULL) {
 715                pr_debug("rcv on socket %p\n", sk);
 716                ping_queue_rcv_skb(sk, skb_get(skb));
 717                sock_put(sk);
 718                return;
 719        }
 720        pr_debug("no socket, dropping\n");
 721
 722        /* We're called from icmp_rcv(). kfree_skb() is done there. */
 723}
 724
 725struct proto ping_prot = {
 726        .name =         "PING",
 727        .owner =        THIS_MODULE,
 728        .init =         ping_init_sock,
 729        .close =        ping_close,
 730        .connect =      ip4_datagram_connect,
 731        .disconnect =   udp_disconnect,
 732        .setsockopt =   ip_setsockopt,
 733        .getsockopt =   ip_getsockopt,
 734        .sendmsg =      ping_sendmsg,
 735        .recvmsg =      ping_recvmsg,
 736        .bind =         ping_bind,
 737        .backlog_rcv =  ping_queue_rcv_skb,
 738        .hash =         ping_v4_hash,
 739        .unhash =       ping_v4_unhash,
 740        .get_port =     ping_v4_get_port,
 741        .obj_size =     sizeof(struct inet_sock),
 742};
 743EXPORT_SYMBOL(ping_prot);
 744
 745#ifdef CONFIG_PROC_FS
 746
 747static struct sock *ping_get_first(struct seq_file *seq, int start)
 748{
 749        struct sock *sk;
 750        struct ping_iter_state *state = seq->private;
 751        struct net *net = seq_file_net(seq);
 752
 753        for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
 754             ++state->bucket) {
 755                struct hlist_nulls_node *node;
 756                struct hlist_nulls_head *hslot;
 757
 758                hslot = &ping_table.hash[state->bucket];
 759
 760                if (hlist_nulls_empty(hslot))
 761                        continue;
 762
 763                sk_nulls_for_each(sk, node, hslot) {
 764                        if (net_eq(sock_net(sk), net))
 765                                goto found;
 766                }
 767        }
 768        sk = NULL;
 769found:
 770        return sk;
 771}
 772
 773static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
 774{
 775        struct ping_iter_state *state = seq->private;
 776        struct net *net = seq_file_net(seq);
 777
 778        do {
 779                sk = sk_nulls_next(sk);
 780        } while (sk && (!net_eq(sock_net(sk), net)));
 781
 782        if (!sk)
 783                return ping_get_first(seq, state->bucket + 1);
 784        return sk;
 785}
 786
 787static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
 788{
 789        struct sock *sk = ping_get_first(seq, 0);
 790
 791        if (sk)
 792                while (pos && (sk = ping_get_next(seq, sk)) != NULL)
 793                        --pos;
 794        return pos ? NULL : sk;
 795}
 796
 797static void *ping_seq_start(struct seq_file *seq, loff_t *pos)
 798{
 799        struct ping_iter_state *state = seq->private;
 800        state->bucket = 0;
 801
 802        read_lock_bh(&ping_table.lock);
 803
 804        return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
 805}
 806
 807static void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 808{
 809        struct sock *sk;
 810
 811        if (v == SEQ_START_TOKEN)
 812                sk = ping_get_idx(seq, 0);
 813        else
 814                sk = ping_get_next(seq, v);
 815
 816        ++*pos;
 817        return sk;
 818}
 819
 820static void ping_seq_stop(struct seq_file *seq, void *v)
 821{
 822        read_unlock_bh(&ping_table.lock);
 823}
 824
 825static void ping_format_sock(struct sock *sp, struct seq_file *f,
 826                int bucket, int *len)
 827{
 828        struct inet_sock *inet = inet_sk(sp);
 829        __be32 dest = inet->inet_daddr;
 830        __be32 src = inet->inet_rcv_saddr;
 831        __u16 destp = ntohs(inet->inet_dport);
 832        __u16 srcp = ntohs(inet->inet_sport);
 833
 834        seq_printf(f, "%5d: %08X:%04X %08X:%04X"
 835                " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n",
 836                bucket, src, srcp, dest, destp, sp->sk_state,
 837                sk_wmem_alloc_get(sp),
 838                sk_rmem_alloc_get(sp),
 839                0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
 840                atomic_read(&sp->sk_refcnt), sp,
 841                atomic_read(&sp->sk_drops), len);
 842}
 843
 844static int ping_seq_show(struct seq_file *seq, void *v)
 845{
 846        if (v == SEQ_START_TOKEN)
 847                seq_printf(seq, "%-127s\n",
 848                           "  sl  local_address rem_address   st tx_queue "
 849                           "rx_queue tr tm->when retrnsmt   uid  timeout "
 850                           "inode ref pointer drops");
 851        else {
 852                struct ping_iter_state *state = seq->private;
 853                int len;
 854
 855                ping_format_sock(v, seq, state->bucket, &len);
 856                seq_printf(seq, "%*s\n", 127 - len, "");
 857        }
 858        return 0;
 859}
 860
 861static const struct seq_operations ping_seq_ops = {
 862        .show           = ping_seq_show,
 863        .start          = ping_seq_start,
 864        .next           = ping_seq_next,
 865        .stop           = ping_seq_stop,
 866};
 867
 868static int ping_seq_open(struct inode *inode, struct file *file)
 869{
 870        return seq_open_net(inode, file, &ping_seq_ops,
 871                           sizeof(struct ping_iter_state));
 872}
 873
 874static const struct file_operations ping_seq_fops = {
 875        .open           = ping_seq_open,
 876        .read           = seq_read,
 877        .llseek         = seq_lseek,
 878        .release        = seq_release_net,
 879};
 880
 881static int ping_proc_register(struct net *net)
 882{
 883        struct proc_dir_entry *p;
 884        int rc = 0;
 885
 886        p = proc_net_fops_create(net, "icmp", S_IRUGO, &ping_seq_fops);
 887        if (!p)
 888                rc = -ENOMEM;
 889        return rc;
 890}
 891
 892static void ping_proc_unregister(struct net *net)
 893{
 894        proc_net_remove(net, "icmp");
 895}
 896
 897
 898static int __net_init ping_proc_init_net(struct net *net)
 899{
 900        return ping_proc_register(net);
 901}
 902
 903static void __net_exit ping_proc_exit_net(struct net *net)
 904{
 905        ping_proc_unregister(net);
 906}
 907
 908static struct pernet_operations ping_net_ops = {
 909        .init = ping_proc_init_net,
 910        .exit = ping_proc_exit_net,
 911};
 912
 913int __init ping_proc_init(void)
 914{
 915        return register_pernet_subsys(&ping_net_ops);
 916}
 917
 918void ping_proc_exit(void)
 919{
 920        unregister_pernet_subsys(&ping_net_ops);
 921}
 922
 923#endif
 924
 925void __init ping_init(void)
 926{
 927        int i;
 928
 929        for (i = 0; i < PING_HTABLE_SIZE; i++)
 930                INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
 931        rwlock_init(&ping_table.lock);
 932}
 933