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 } 932