net/ipv4/ping.c

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