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 <linux/uaccess.h> 24 #include <linux/types.h> 25 #include <linux/fcntl.h> 26 #include <linux/socket.h> 27 #include <linux/sockios.h> 28 #include <linux/in.h> 29 #include <linux/errno.h> 30 #include <linux/timer.h> 31 #include <linux/mm.h> 32 #include <linux/inet.h> 33 #include <linux/netdevice.h> 34 #include <net/snmp.h> 35 #include <net/ip.h> 36 #include <net/ipv6.h> 37 #include <net/icmp.h> 38 #include <net/protocol.h> 39 #include <linux/skbuff.h> 40 #include <linux/proc_fs.h> 41 #include <linux/export.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 int num, unsigned int mask) 55 { 56 int res = (num + net_hash_mix(net)) & mask; 57 58 pr_debug("hash(%d) = %d\n", num, res); 59 return res; 60 } 61 62 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table, 63 struct net *net, unsigned int num) 64 { 65 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)]; 66 } 67 68 static 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; 96 next_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; 123 124 fail: 125 write_unlock_bh(&ping_table.lock); 126 return 1; 127 } 128 129 static 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 } 134 135 static 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 } 149 150 static 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; 182 exit: 183 read_unlock_bh(&ping_table.lock); 184 185 return sk; 186 } 187 188 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 189 kgid_t *high) 190 { 191 kgid_t *data = net->ipv4.sysctl_ping_group_range; 192 unsigned int seq; 193 194 do { 195 seq = read_seqbegin(&sysctl_local_ports.lock); 196 197 *low = data[0]; 198 *high = data[1]; 199 } while (read_seqretry(&sysctl_local_ports.lock, seq)); 200 } 201 202 203 static int ping_init_sock(struct sock *sk) 204 { 205 struct net *net = sock_net(sk); 206 kgid_t group = current_egid(); 207 struct group_info *group_info = get_current_groups(); 208 int i, j, count = group_info->ngroups; 209 kgid_t low, high; 210 211 inet_get_ping_group_range_net(net, &low, &high); 212 if (gid_lte(low, group) && gid_lte(group, high)) 213 return 0; 214 215 for (i = 0; i < group_info->nblocks; i++) { 216 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count); 217 for (j = 0; j < cp_count; j++) { 218 kgid_t gid = group_info->blocks[i][j]; 219 if (gid_lte(low, gid) && gid_lte(gid, high)) 220 return 0; 221 } 222 223 count -= cp_count; 224 } 225 226 return -EACCES; 227 } 228 229 static 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 */ 242 243 static 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); 296 out: 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 */ 305 306 static 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 */ 317 318 static int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); 319 320 void 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 ipv4_sk_update_pmtu(skb, sk, info); 369 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 370 err = EMSGSIZE; 371 harderr = 1; 372 break; 373 } 374 goto out; 375 } 376 err = EHOSTUNREACH; 377 if (code <= NR_ICMP_UNREACH) { 378 harderr = icmp_err_convert[code].fatal; 379 err = icmp_err_convert[code].errno; 380 } 381 break; 382 case ICMP_REDIRECT: 383 /* See ICMP_SOURCE_QUENCH */ 384 ipv4_sk_redirect(skb, sk); 385 err = EREMOTEIO; 386 break; 387 } 388 389 /* 390 * RFC1122: OK. Passes ICMP errors back to application, as per 391 * 4.1.3.3. 392 */ 393 if (!inet_sock->recverr) { 394 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 395 goto out; 396 } else { 397 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 398 info, (u8 *)icmph); 399 } 400 sk->sk_err = err; 401 sk->sk_error_report(sk); 402 out: 403 sock_put(sk); 404 } 405 406 /* 407 * Copy and checksum an ICMP Echo packet from user space into a buffer. 408 */ 409 410 struct pingfakehdr { 411 struct icmphdr icmph; 412 struct iovec *iov; 413 __wsum wcheck; 414 }; 415 416 static int ping_getfrag(void *from, char *to, 417 int offset, int fraglen, int odd, struct sk_buff *skb) 418 { 419 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 420 421 if (offset == 0) { 422 if (fraglen < sizeof(struct icmphdr)) 423 BUG(); 424 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr), 425 pfh->iov, 0, fraglen - sizeof(struct icmphdr), 426 &pfh->wcheck)) 427 return -EFAULT; 428 429 return 0; 430 } 431 if (offset < sizeof(struct icmphdr)) 432 BUG(); 433 if (csum_partial_copy_fromiovecend 434 (to, pfh->iov, offset - sizeof(struct icmphdr), 435 fraglen, &pfh->wcheck)) 436 return -EFAULT; 437 return 0; 438 } 439 440 static int ping_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 441 struct flowi4 *fl4) 442 { 443 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 444 445 pfh->wcheck = csum_partial((char *)&pfh->icmph, 446 sizeof(struct icmphdr), pfh->wcheck); 447 pfh->icmph.checksum = csum_fold(pfh->wcheck); 448 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 449 skb->ip_summed = CHECKSUM_NONE; 450 return ip_push_pending_frames(sk, fl4); 451 } 452 453 static int ping_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 454 size_t len) 455 { 456 struct net *net = sock_net(sk); 457 struct flowi4 fl4; 458 struct inet_sock *inet = inet_sk(sk); 459 struct ipcm_cookie ipc; 460 struct icmphdr user_icmph; 461 struct pingfakehdr pfh; 462 struct rtable *rt = NULL; 463 struct ip_options_data opt_copy; 464 int free = 0; 465 __be32 saddr, daddr, faddr; 466 u8 tos; 467 int err; 468 469 pr_debug("ping_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 470 471 472 if (len > 0xFFFF) 473 return -EMSGSIZE; 474 475 /* 476 * Check the flags. 477 */ 478 479 /* Mirror BSD error message compatibility */ 480 if (msg->msg_flags & MSG_OOB) 481 return -EOPNOTSUPP; 482 483 /* 484 * Fetch the ICMP header provided by the userland. 485 * iovec is modified! 486 */ 487 488 if (memcpy_fromiovec((u8 *)&user_icmph, msg->msg_iov, 489 sizeof(struct icmphdr))) 490 return -EFAULT; 491 if (!ping_supported(user_icmph.type, user_icmph.code)) 492 return -EINVAL; 493 494 /* 495 * Get and verify the address. 496 */ 497 498 if (msg->msg_name) { 499 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name; 500 if (msg->msg_namelen < sizeof(*usin)) 501 return -EINVAL; 502 if (usin->sin_family != AF_INET) 503 return -EINVAL; 504 daddr = usin->sin_addr.s_addr; 505 /* no remote port */ 506 } else { 507 if (sk->sk_state != TCP_ESTABLISHED) 508 return -EDESTADDRREQ; 509 daddr = inet->inet_daddr; 510 /* no remote port */ 511 } 512 513 ipc.addr = inet->inet_saddr; 514 ipc.opt = NULL; 515 ipc.oif = sk->sk_bound_dev_if; 516 ipc.tx_flags = 0; 517 err = sock_tx_timestamp(sk, &ipc.tx_flags); 518 if (err) 519 return err; 520 521 if (msg->msg_controllen) { 522 err = ip_cmsg_send(sock_net(sk), msg, &ipc); 523 if (err) 524 return err; 525 if (ipc.opt) 526 free = 1; 527 } 528 if (!ipc.opt) { 529 struct ip_options_rcu *inet_opt; 530 531 rcu_read_lock(); 532 inet_opt = rcu_dereference(inet->inet_opt); 533 if (inet_opt) { 534 memcpy(&opt_copy, inet_opt, 535 sizeof(*inet_opt) + inet_opt->opt.optlen); 536 ipc.opt = &opt_copy.opt; 537 } 538 rcu_read_unlock(); 539 } 540 541 saddr = ipc.addr; 542 ipc.addr = faddr = daddr; 543 544 if (ipc.opt && ipc.opt->opt.srr) { 545 if (!daddr) 546 return -EINVAL; 547 faddr = ipc.opt->opt.faddr; 548 } 549 tos = RT_TOS(inet->tos); 550 if (sock_flag(sk, SOCK_LOCALROUTE) || 551 (msg->msg_flags & MSG_DONTROUTE) || 552 (ipc.opt && ipc.opt->opt.is_strictroute)) { 553 tos |= RTO_ONLINK; 554 } 555 556 if (ipv4_is_multicast(daddr)) { 557 if (!ipc.oif) 558 ipc.oif = inet->mc_index; 559 if (!saddr) 560 saddr = inet->mc_addr; 561 } else if (!ipc.oif) 562 ipc.oif = inet->uc_index; 563 564 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos, 565 RT_SCOPE_UNIVERSE, sk->sk_protocol, 566 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0); 567 568 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 569 rt = ip_route_output_flow(net, &fl4, sk); 570 if (IS_ERR(rt)) { 571 err = PTR_ERR(rt); 572 rt = NULL; 573 if (err == -ENETUNREACH) 574 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); 575 goto out; 576 } 577 578 err = -EACCES; 579 if ((rt->rt_flags & RTCF_BROADCAST) && 580 !sock_flag(sk, SOCK_BROADCAST)) 581 goto out; 582 583 if (msg->msg_flags & MSG_CONFIRM) 584 goto do_confirm; 585 back_from_confirm: 586 587 if (!ipc.addr) 588 ipc.addr = fl4.daddr; 589 590 lock_sock(sk); 591 592 pfh.icmph.type = user_icmph.type; /* already checked */ 593 pfh.icmph.code = user_icmph.code; /* ditto */ 594 pfh.icmph.checksum = 0; 595 pfh.icmph.un.echo.id = inet->inet_sport; 596 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 597 pfh.iov = msg->msg_iov; 598 pfh.wcheck = 0; 599 600 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 601 0, &ipc, &rt, msg->msg_flags); 602 if (err) 603 ip_flush_pending_frames(sk); 604 else 605 err = ping_push_pending_frames(sk, &pfh, &fl4); 606 release_sock(sk); 607 608 out: 609 ip_rt_put(rt); 610 if (free) 611 kfree(ipc.opt); 612 if (!err) { 613 icmp_out_count(sock_net(sk), user_icmph.type); 614 return len; 615 } 616 return err; 617 618 do_confirm: 619 dst_confirm(&rt->dst); 620 if (!(msg->msg_flags & MSG_PROBE) || len) 621 goto back_from_confirm; 622 err = 0; 623 goto out; 624 } 625 626 static int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 627 size_t len, int noblock, int flags, int *addr_len) 628 { 629 struct inet_sock *isk = inet_sk(sk); 630 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 631 struct sk_buff *skb; 632 int copied, err; 633 634 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 635 636 err = -EOPNOTSUPP; 637 if (flags & MSG_OOB) 638 goto out; 639 640 if (addr_len) 641 *addr_len = sizeof(*sin); 642 643 if (flags & MSG_ERRQUEUE) 644 return ip_recv_error(sk, msg, len); 645 646 skb = skb_recv_datagram(sk, flags, noblock, &err); 647 if (!skb) 648 goto out; 649 650 copied = skb->len; 651 if (copied > len) { 652 msg->msg_flags |= MSG_TRUNC; 653 copied = len; 654 } 655 656 /* Don't bother checking the checksum */ 657 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 658 if (err) 659 goto done; 660 661 sock_recv_timestamp(msg, sk, skb); 662 663 /* Copy the address. */ 664 if (sin) { 665 sin->sin_family = AF_INET; 666 sin->sin_port = 0 /* skb->h.uh->source */; 667 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 668 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 669 } 670 if (isk->cmsg_flags) 671 ip_cmsg_recv(msg, skb); 672 err = copied; 673 674 done: 675 skb_free_datagram(sk, skb); 676 out: 677 pr_debug("ping_recvmsg -> %d\n", err); 678 return err; 679 } 680 681 static int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 682 { 683 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 684 inet_sk(sk), inet_sk(sk)->inet_num, skb); 685 if (sock_queue_rcv_skb(sk, skb) < 0) { 686 kfree_skb(skb); 687 pr_debug("ping_queue_rcv_skb -> failed\n"); 688 return -1; 689 } 690 return 0; 691 } 692 693 694 /* 695 * All we need to do is get the socket. 696 */ 697 698 void ping_rcv(struct sk_buff *skb) 699 { 700 struct sock *sk; 701 struct net *net = dev_net(skb->dev); 702 struct iphdr *iph = ip_hdr(skb); 703 struct icmphdr *icmph = icmp_hdr(skb); 704 __be32 saddr = iph->saddr; 705 __be32 daddr = iph->daddr; 706 707 /* We assume the packet has already been checked by icmp_rcv */ 708 709 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 710 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 711 712 /* Push ICMP header back */ 713 skb_push(skb, skb->data - (u8 *)icmph); 714 715 sk = ping_v4_lookup(net, saddr, daddr, ntohs(icmph->un.echo.id), 716 skb->dev->ifindex); 717 if (sk != NULL) { 718 pr_debug("rcv on socket %p\n", sk); 719 ping_queue_rcv_skb(sk, skb_get(skb)); 720 sock_put(sk); 721 return; 722 } 723 pr_debug("no socket, dropping\n"); 724 725 /* We're called from icmp_rcv(). kfree_skb() is done there. */ 726 } 727 728 struct proto ping_prot = { 729 .name = "PING", 730 .owner = THIS_MODULE, 731 .init = ping_init_sock, 732 .close = ping_close, 733 .connect = ip4_datagram_connect, 734 .disconnect = udp_disconnect, 735 .setsockopt = ip_setsockopt, 736 .getsockopt = ip_getsockopt, 737 .sendmsg = ping_sendmsg, 738 .recvmsg = ping_recvmsg, 739 .bind = ping_bind, 740 .backlog_rcv = ping_queue_rcv_skb, 741 .release_cb = ip4_datagram_release_cb, 742 .hash = ping_v4_hash, 743 .unhash = ping_v4_unhash, 744 .get_port = ping_v4_get_port, 745 .obj_size = sizeof(struct inet_sock), 746 }; 747 EXPORT_SYMBOL(ping_prot); 748 749 #ifdef CONFIG_PROC_FS 750 751 static struct sock *ping_get_first(struct seq_file *seq, int start) 752 { 753 struct sock *sk; 754 struct ping_iter_state *state = seq->private; 755 struct net *net = seq_file_net(seq); 756 757 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 758 ++state->bucket) { 759 struct hlist_nulls_node *node; 760 struct hlist_nulls_head *hslot; 761 762 hslot = &ping_table.hash[state->bucket]; 763 764 if (hlist_nulls_empty(hslot)) 765 continue; 766 767 sk_nulls_for_each(sk, node, hslot) { 768 if (net_eq(sock_net(sk), net)) 769 goto found; 770 } 771 } 772 sk = NULL; 773 found: 774 return sk; 775 } 776 777 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 778 { 779 struct ping_iter_state *state = seq->private; 780 struct net *net = seq_file_net(seq); 781 782 do { 783 sk = sk_nulls_next(sk); 784 } while (sk && (!net_eq(sock_net(sk), net))); 785 786 if (!sk) 787 return ping_get_first(seq, state->bucket + 1); 788 return sk; 789 } 790 791 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 792 { 793 struct sock *sk = ping_get_first(seq, 0); 794 795 if (sk) 796 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 797 --pos; 798 return pos ? NULL : sk; 799 } 800 801 static void *ping_seq_start(struct seq_file *seq, loff_t *pos) 802 { 803 struct ping_iter_state *state = seq->private; 804 state->bucket = 0; 805 806 read_lock_bh(&ping_table.lock); 807 808 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 809 } 810 811 static void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 812 { 813 struct sock *sk; 814 815 if (v == SEQ_START_TOKEN) 816 sk = ping_get_idx(seq, 0); 817 else 818 sk = ping_get_next(seq, v); 819 820 ++*pos; 821 return sk; 822 } 823 824 static void ping_seq_stop(struct seq_file *seq, void *v) 825 { 826 read_unlock_bh(&ping_table.lock); 827 } 828 829 static void ping_format_sock(struct sock *sp, struct seq_file *f, 830 int bucket, int *len) 831 { 832 struct inet_sock *inet = inet_sk(sp); 833 __be32 dest = inet->inet_daddr; 834 __be32 src = inet->inet_rcv_saddr; 835 __u16 destp = ntohs(inet->inet_dport); 836 __u16 srcp = ntohs(inet->inet_sport); 837 838 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 839 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n", 840 bucket, src, srcp, dest, destp, sp->sk_state, 841 sk_wmem_alloc_get(sp), 842 sk_rmem_alloc_get(sp), 843 0, 0L, 0, 844 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 845 0, sock_i_ino(sp), 846 atomic_read(&sp->sk_refcnt), sp, 847 atomic_read(&sp->sk_drops), len); 848 } 849 850 static int ping_seq_show(struct seq_file *seq, void *v) 851 { 852 if (v == SEQ_START_TOKEN) 853 seq_printf(seq, "%-127s\n", 854 " sl local_address rem_address st tx_queue " 855 "rx_queue tr tm->when retrnsmt uid timeout " 856 "inode ref pointer drops"); 857 else { 858 struct ping_iter_state *state = seq->private; 859 int len; 860 861 ping_format_sock(v, seq, state->bucket, &len); 862 seq_printf(seq, "%*s\n", 127 - len, ""); 863 } 864 return 0; 865 } 866 867 static const struct seq_operations ping_seq_ops = { 868 .show = ping_seq_show, 869 .start = ping_seq_start, 870 .next = ping_seq_next, 871 .stop = ping_seq_stop, 872 }; 873 874 static int ping_seq_open(struct inode *inode, struct file *file) 875 { 876 return seq_open_net(inode, file, &ping_seq_ops, 877 sizeof(struct ping_iter_state)); 878 } 879 880 static const struct file_operations ping_seq_fops = { 881 .open = ping_seq_open, 882 .read = seq_read, 883 .llseek = seq_lseek, 884 .release = seq_release_net, 885 }; 886 887 static int ping_proc_register(struct net *net) 888 { 889 struct proc_dir_entry *p; 890 int rc = 0; 891 892 p = proc_net_fops_create(net, "icmp", S_IRUGO, &ping_seq_fops); 893 if (!p) 894 rc = -ENOMEM; 895 return rc; 896 } 897 898 static void ping_proc_unregister(struct net *net) 899 { 900 proc_net_remove(net, "icmp"); 901 } 902 903 904 static int __net_init ping_proc_init_net(struct net *net) 905 { 906 return ping_proc_register(net); 907 } 908 909 static void __net_exit ping_proc_exit_net(struct net *net) 910 { 911 ping_proc_unregister(net); 912 } 913 914 static struct pernet_operations ping_net_ops = { 915 .init = ping_proc_init_net, 916 .exit = ping_proc_exit_net, 917 }; 918 919 int __init ping_proc_init(void) 920 { 921 return register_pernet_subsys(&ping_net_ops); 922 } 923 924 void ping_proc_exit(void) 925 { 926 unregister_pernet_subsys(&ping_net_ops); 927 } 928 929 #endif 930 931 void __init ping_init(void) 932 { 933 int i; 934 935 for (i = 0; i < PING_HTABLE_SIZE; i++) 936 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 937 rwlock_init(&ping_table.lock); 938 } 939