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/icmp.h> 37 #include <net/protocol.h> 38 #include <linux/skbuff.h> 39 #include <linux/proc_fs.h> 40 #include <linux/export.h> 41 #include <net/sock.h> 42 #include <net/ping.h> 43 #include <net/udp.h> 44 #include <net/route.h> 45 #include <net/inet_common.h> 46 #include <net/checksum.h> 47 48 #if IS_ENABLED(CONFIG_IPV6) 49 #include <linux/in6.h> 50 #include <linux/icmpv6.h> 51 #include <net/addrconf.h> 52 #include <net/ipv6.h> 53 #include <net/transp_v6.h> 54 #endif 55 56 struct ping_table { 57 struct hlist_nulls_head hash[PING_HTABLE_SIZE]; 58 rwlock_t lock; 59 }; 60 61 static struct ping_table ping_table; 62 struct pingv6_ops pingv6_ops; 63 EXPORT_SYMBOL_GPL(pingv6_ops); 64 65 static u16 ping_port_rover; 66 67 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask) 68 { 69 u32 res = (num + net_hash_mix(net)) & mask; 70 71 pr_debug("hash(%u) = %u\n", num, res); 72 return res; 73 } 74 EXPORT_SYMBOL_GPL(ping_hash); 75 76 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table, 77 struct net *net, unsigned int num) 78 { 79 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)]; 80 } 81 82 int ping_get_port(struct sock *sk, unsigned short ident) 83 { 84 struct hlist_nulls_node *node; 85 struct hlist_nulls_head *hlist; 86 struct inet_sock *isk, *isk2; 87 struct sock *sk2 = NULL; 88 89 isk = inet_sk(sk); 90 write_lock_bh(&ping_table.lock); 91 if (ident == 0) { 92 u32 i; 93 u16 result = ping_port_rover + 1; 94 95 for (i = 0; i < (1L << 16); i++, result++) { 96 if (!result) 97 result++; /* avoid zero */ 98 hlist = ping_hashslot(&ping_table, sock_net(sk), 99 result); 100 ping_portaddr_for_each_entry(sk2, node, hlist) { 101 isk2 = inet_sk(sk2); 102 103 if (isk2->inet_num == result) 104 goto next_port; 105 } 106 107 /* found */ 108 ping_port_rover = ident = result; 109 break; 110 next_port: 111 ; 112 } 113 if (i >= (1L << 16)) 114 goto fail; 115 } else { 116 hlist = ping_hashslot(&ping_table, sock_net(sk), ident); 117 ping_portaddr_for_each_entry(sk2, node, hlist) { 118 isk2 = inet_sk(sk2); 119 120 /* BUG? Why is this reuse and not reuseaddr? ping.c 121 * doesn't turn off SO_REUSEADDR, and it doesn't expect 122 * that other ping processes can steal its packets. 123 */ 124 if ((isk2->inet_num == ident) && 125 (sk2 != sk) && 126 (!sk2->sk_reuse || !sk->sk_reuse)) 127 goto fail; 128 } 129 } 130 131 pr_debug("found port/ident = %d\n", ident); 132 isk->inet_num = ident; 133 if (sk_unhashed(sk)) { 134 pr_debug("was not hashed\n"); 135 sock_hold(sk); 136 hlist_nulls_add_head(&sk->sk_nulls_node, hlist); 137 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 138 } 139 write_unlock_bh(&ping_table.lock); 140 return 0; 141 142 fail: 143 write_unlock_bh(&ping_table.lock); 144 return 1; 145 } 146 EXPORT_SYMBOL_GPL(ping_get_port); 147 148 void ping_hash(struct sock *sk) 149 { 150 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num); 151 BUG(); /* "Please do not press this button again." */ 152 } 153 154 void ping_unhash(struct sock *sk) 155 { 156 struct inet_sock *isk = inet_sk(sk); 157 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); 158 if (sk_hashed(sk)) { 159 write_lock_bh(&ping_table.lock); 160 hlist_nulls_del(&sk->sk_nulls_node); 161 sk_nulls_node_init(&sk->sk_nulls_node); 162 sock_put(sk); 163 isk->inet_num = 0; 164 isk->inet_sport = 0; 165 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 166 write_unlock_bh(&ping_table.lock); 167 } 168 } 169 EXPORT_SYMBOL_GPL(ping_unhash); 170 171 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) 172 { 173 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); 174 struct sock *sk = NULL; 175 struct inet_sock *isk; 176 struct hlist_nulls_node *hnode; 177 int dif = skb->dev->ifindex; 178 179 if (skb->protocol == htons(ETH_P_IP)) { 180 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n", 181 (int)ident, &ip_hdr(skb)->daddr, dif); 182 #if IS_ENABLED(CONFIG_IPV6) 183 } else if (skb->protocol == htons(ETH_P_IPV6)) { 184 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", 185 (int)ident, &ipv6_hdr(skb)->daddr, dif); 186 #endif 187 } 188 189 read_lock_bh(&ping_table.lock); 190 191 ping_portaddr_for_each_entry(sk, hnode, hslot) { 192 isk = inet_sk(sk); 193 194 pr_debug("iterate\n"); 195 if (isk->inet_num != ident) 196 continue; 197 198 if (skb->protocol == htons(ETH_P_IP) && 199 sk->sk_family == AF_INET) { 200 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, 201 (int) isk->inet_num, &isk->inet_rcv_saddr, 202 sk->sk_bound_dev_if); 203 204 if (isk->inet_rcv_saddr && 205 isk->inet_rcv_saddr != ip_hdr(skb)->daddr) 206 continue; 207 #if IS_ENABLED(CONFIG_IPV6) 208 } else if (skb->protocol == htons(ETH_P_IPV6) && 209 sk->sk_family == AF_INET6) { 210 211 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, 212 (int) isk->inet_num, 213 &sk->sk_v6_rcv_saddr, 214 sk->sk_bound_dev_if); 215 216 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 217 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, 218 &ipv6_hdr(skb)->daddr)) 219 continue; 220 #endif 221 } else { 222 continue; 223 } 224 225 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) 226 continue; 227 228 sock_hold(sk); 229 goto exit; 230 } 231 232 sk = NULL; 233 exit: 234 read_unlock_bh(&ping_table.lock); 235 236 return sk; 237 } 238 239 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 240 kgid_t *high) 241 { 242 kgid_t *data = net->ipv4.ping_group_range.range; 243 unsigned int seq; 244 245 do { 246 seq = read_seqbegin(&net->ipv4.ping_group_range.lock); 247 248 *low = data[0]; 249 *high = data[1]; 250 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); 251 } 252 253 254 int ping_init_sock(struct sock *sk) 255 { 256 struct net *net = sock_net(sk); 257 kgid_t group = current_egid(); 258 struct group_info *group_info; 259 int i, j, count; 260 kgid_t low, high; 261 int ret = 0; 262 263 if (sk->sk_family == AF_INET6) 264 sk->sk_ipv6only = 1; 265 266 inet_get_ping_group_range_net(net, &low, &high); 267 if (gid_lte(low, group) && gid_lte(group, high)) 268 return 0; 269 270 group_info = get_current_groups(); 271 count = group_info->ngroups; 272 for (i = 0; i < group_info->nblocks; i++) { 273 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count); 274 for (j = 0; j < cp_count; j++) { 275 kgid_t gid = group_info->blocks[i][j]; 276 if (gid_lte(low, gid) && gid_lte(gid, high)) 277 goto out_release_group; 278 } 279 280 count -= cp_count; 281 } 282 283 ret = -EACCES; 284 285 out_release_group: 286 put_group_info(group_info); 287 return ret; 288 } 289 EXPORT_SYMBOL_GPL(ping_init_sock); 290 291 void ping_close(struct sock *sk, long timeout) 292 { 293 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 294 inet_sk(sk), inet_sk(sk)->inet_num); 295 pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter); 296 297 sk_common_release(sk); 298 } 299 EXPORT_SYMBOL_GPL(ping_close); 300 301 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 302 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 303 struct sockaddr *uaddr, int addr_len) { 304 struct net *net = sock_net(sk); 305 if (sk->sk_family == AF_INET) { 306 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 307 int chk_addr_ret; 308 309 if (addr_len < sizeof(*addr)) 310 return -EINVAL; 311 312 if (addr->sin_family != AF_INET && 313 !(addr->sin_family == AF_UNSPEC && 314 addr->sin_addr.s_addr == htonl(INADDR_ANY))) 315 return -EAFNOSUPPORT; 316 317 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 318 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 319 320 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); 321 322 if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) 323 chk_addr_ret = RTN_LOCAL; 324 325 if ((net->ipv4.sysctl_ip_nonlocal_bind == 0 && 326 isk->freebind == 0 && isk->transparent == 0 && 327 chk_addr_ret != RTN_LOCAL) || 328 chk_addr_ret == RTN_MULTICAST || 329 chk_addr_ret == RTN_BROADCAST) 330 return -EADDRNOTAVAIL; 331 332 #if IS_ENABLED(CONFIG_IPV6) 333 } else if (sk->sk_family == AF_INET6) { 334 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 335 int addr_type, scoped, has_addr; 336 struct net_device *dev = NULL; 337 338 if (addr_len < sizeof(*addr)) 339 return -EINVAL; 340 341 if (addr->sin6_family != AF_INET6) 342 return -EAFNOSUPPORT; 343 344 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 345 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 346 347 addr_type = ipv6_addr_type(&addr->sin6_addr); 348 scoped = __ipv6_addr_needs_scope_id(addr_type); 349 if ((addr_type != IPV6_ADDR_ANY && 350 !(addr_type & IPV6_ADDR_UNICAST)) || 351 (scoped && !addr->sin6_scope_id)) 352 return -EINVAL; 353 354 rcu_read_lock(); 355 if (addr->sin6_scope_id) { 356 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 357 if (!dev) { 358 rcu_read_unlock(); 359 return -ENODEV; 360 } 361 } 362 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 363 scoped); 364 rcu_read_unlock(); 365 366 if (!(net->ipv6.sysctl.ip_nonlocal_bind || 367 isk->freebind || isk->transparent || has_addr || 368 addr_type == IPV6_ADDR_ANY)) 369 return -EADDRNOTAVAIL; 370 371 if (scoped) 372 sk->sk_bound_dev_if = addr->sin6_scope_id; 373 #endif 374 } else { 375 return -EAFNOSUPPORT; 376 } 377 return 0; 378 } 379 380 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 381 { 382 if (saddr->sa_family == AF_INET) { 383 struct inet_sock *isk = inet_sk(sk); 384 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 385 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 386 #if IS_ENABLED(CONFIG_IPV6) 387 } else if (saddr->sa_family == AF_INET6) { 388 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 389 struct ipv6_pinfo *np = inet6_sk(sk); 390 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 391 #endif 392 } 393 } 394 395 static void ping_clear_saddr(struct sock *sk, int dif) 396 { 397 sk->sk_bound_dev_if = dif; 398 if (sk->sk_family == AF_INET) { 399 struct inet_sock *isk = inet_sk(sk); 400 isk->inet_rcv_saddr = isk->inet_saddr = 0; 401 #if IS_ENABLED(CONFIG_IPV6) 402 } else if (sk->sk_family == AF_INET6) { 403 struct ipv6_pinfo *np = inet6_sk(sk); 404 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 405 memset(&np->saddr, 0, sizeof(np->saddr)); 406 #endif 407 } 408 } 409 /* 410 * We need our own bind because there are no privileged id's == local ports. 411 * Moreover, we don't allow binding to multi- and broadcast addresses. 412 */ 413 414 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 415 { 416 struct inet_sock *isk = inet_sk(sk); 417 unsigned short snum; 418 int err; 419 int dif = sk->sk_bound_dev_if; 420 421 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 422 if (err) 423 return err; 424 425 lock_sock(sk); 426 427 err = -EINVAL; 428 if (isk->inet_num != 0) 429 goto out; 430 431 err = -EADDRINUSE; 432 ping_set_saddr(sk, uaddr); 433 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 434 if (ping_get_port(sk, snum) != 0) { 435 ping_clear_saddr(sk, dif); 436 goto out; 437 } 438 439 pr_debug("after bind(): num = %d, dif = %d\n", 440 (int)isk->inet_num, 441 (int)sk->sk_bound_dev_if); 442 443 err = 0; 444 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 445 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 446 #if IS_ENABLED(CONFIG_IPV6) 447 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 448 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 449 #endif 450 451 if (snum) 452 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 453 isk->inet_sport = htons(isk->inet_num); 454 isk->inet_daddr = 0; 455 isk->inet_dport = 0; 456 457 #if IS_ENABLED(CONFIG_IPV6) 458 if (sk->sk_family == AF_INET6) 459 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 460 #endif 461 462 sk_dst_reset(sk); 463 out: 464 release_sock(sk); 465 pr_debug("ping_v4_bind -> %d\n", err); 466 return err; 467 } 468 EXPORT_SYMBOL_GPL(ping_bind); 469 470 /* 471 * Is this a supported type of ICMP message? 472 */ 473 474 static inline int ping_supported(int family, int type, int code) 475 { 476 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 477 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0); 478 } 479 480 /* 481 * This routine is called by the ICMP module when it gets some 482 * sort of error condition. 483 */ 484 485 void ping_err(struct sk_buff *skb, int offset, u32 info) 486 { 487 int family; 488 struct icmphdr *icmph; 489 struct inet_sock *inet_sock; 490 int type; 491 int code; 492 struct net *net = dev_net(skb->dev); 493 struct sock *sk; 494 int harderr; 495 int err; 496 497 if (skb->protocol == htons(ETH_P_IP)) { 498 family = AF_INET; 499 type = icmp_hdr(skb)->type; 500 code = icmp_hdr(skb)->code; 501 icmph = (struct icmphdr *)(skb->data + offset); 502 } else if (skb->protocol == htons(ETH_P_IPV6)) { 503 family = AF_INET6; 504 type = icmp6_hdr(skb)->icmp6_type; 505 code = icmp6_hdr(skb)->icmp6_code; 506 icmph = (struct icmphdr *) (skb->data + offset); 507 } else { 508 BUG(); 509 } 510 511 /* We assume the packet has already been checked by icmp_unreach */ 512 513 if (!ping_supported(family, icmph->type, icmph->code)) 514 return; 515 516 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 517 skb->protocol, type, code, ntohs(icmph->un.echo.id), 518 ntohs(icmph->un.echo.sequence)); 519 520 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 521 if (!sk) { 522 pr_debug("no socket, dropping\n"); 523 return; /* No socket for error */ 524 } 525 pr_debug("err on socket %p\n", sk); 526 527 err = 0; 528 harderr = 0; 529 inet_sock = inet_sk(sk); 530 531 if (skb->protocol == htons(ETH_P_IP)) { 532 switch (type) { 533 default: 534 case ICMP_TIME_EXCEEDED: 535 err = EHOSTUNREACH; 536 break; 537 case ICMP_SOURCE_QUENCH: 538 /* This is not a real error but ping wants to see it. 539 * Report it with some fake errno. 540 */ 541 err = EREMOTEIO; 542 break; 543 case ICMP_PARAMETERPROB: 544 err = EPROTO; 545 harderr = 1; 546 break; 547 case ICMP_DEST_UNREACH: 548 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 549 ipv4_sk_update_pmtu(skb, sk, info); 550 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 551 err = EMSGSIZE; 552 harderr = 1; 553 break; 554 } 555 goto out; 556 } 557 err = EHOSTUNREACH; 558 if (code <= NR_ICMP_UNREACH) { 559 harderr = icmp_err_convert[code].fatal; 560 err = icmp_err_convert[code].errno; 561 } 562 break; 563 case ICMP_REDIRECT: 564 /* See ICMP_SOURCE_QUENCH */ 565 ipv4_sk_redirect(skb, sk); 566 err = EREMOTEIO; 567 break; 568 } 569 #if IS_ENABLED(CONFIG_IPV6) 570 } else if (skb->protocol == htons(ETH_P_IPV6)) { 571 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 572 #endif 573 } 574 575 /* 576 * RFC1122: OK. Passes ICMP errors back to application, as per 577 * 4.1.3.3. 578 */ 579 if ((family == AF_INET && !inet_sock->recverr) || 580 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 581 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 582 goto out; 583 } else { 584 if (family == AF_INET) { 585 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 586 info, (u8 *)icmph); 587 #if IS_ENABLED(CONFIG_IPV6) 588 } else if (family == AF_INET6) { 589 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 590 info, (u8 *)icmph); 591 #endif 592 } 593 } 594 sk->sk_err = err; 595 sk->sk_error_report(sk); 596 out: 597 sock_put(sk); 598 } 599 EXPORT_SYMBOL_GPL(ping_err); 600 601 /* 602 * Copy and checksum an ICMP Echo packet from user space into a buffer 603 * starting from the payload. 604 */ 605 606 int ping_getfrag(void *from, char *to, 607 int offset, int fraglen, int odd, struct sk_buff *skb) 608 { 609 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 610 611 if (offset == 0) { 612 fraglen -= sizeof(struct icmphdr); 613 if (fraglen < 0) 614 BUG(); 615 if (csum_and_copy_from_iter(to + sizeof(struct icmphdr), 616 fraglen, &pfh->wcheck, 617 &pfh->msg->msg_iter) != fraglen) 618 return -EFAULT; 619 } else if (offset < sizeof(struct icmphdr)) { 620 BUG(); 621 } else { 622 if (csum_and_copy_from_iter(to, fraglen, &pfh->wcheck, 623 &pfh->msg->msg_iter) != fraglen) 624 return -EFAULT; 625 } 626 627 #if IS_ENABLED(CONFIG_IPV6) 628 /* For IPv6, checksum each skb as we go along, as expected by 629 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 630 * wcheck, it will be finalized in ping_v4_push_pending_frames. 631 */ 632 if (pfh->family == AF_INET6) { 633 skb->csum = pfh->wcheck; 634 skb->ip_summed = CHECKSUM_NONE; 635 pfh->wcheck = 0; 636 } 637 #endif 638 639 return 0; 640 } 641 EXPORT_SYMBOL_GPL(ping_getfrag); 642 643 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 644 struct flowi4 *fl4) 645 { 646 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 647 648 pfh->wcheck = csum_partial((char *)&pfh->icmph, 649 sizeof(struct icmphdr), pfh->wcheck); 650 pfh->icmph.checksum = csum_fold(pfh->wcheck); 651 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 652 skb->ip_summed = CHECKSUM_NONE; 653 return ip_push_pending_frames(sk, fl4); 654 } 655 656 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 657 void *user_icmph, size_t icmph_len) { 658 u8 type, code; 659 660 if (len > 0xFFFF) 661 return -EMSGSIZE; 662 663 /* 664 * Check the flags. 665 */ 666 667 /* Mirror BSD error message compatibility */ 668 if (msg->msg_flags & MSG_OOB) 669 return -EOPNOTSUPP; 670 671 /* 672 * Fetch the ICMP header provided by the userland. 673 * iovec is modified! The ICMP header is consumed. 674 */ 675 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 676 return -EFAULT; 677 678 if (family == AF_INET) { 679 type = ((struct icmphdr *) user_icmph)->type; 680 code = ((struct icmphdr *) user_icmph)->code; 681 #if IS_ENABLED(CONFIG_IPV6) 682 } else if (family == AF_INET6) { 683 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 684 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 685 #endif 686 } else { 687 BUG(); 688 } 689 690 if (!ping_supported(family, type, code)) 691 return -EINVAL; 692 693 return 0; 694 } 695 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 696 697 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 698 { 699 struct net *net = sock_net(sk); 700 struct flowi4 fl4; 701 struct inet_sock *inet = inet_sk(sk); 702 struct ipcm_cookie ipc; 703 struct icmphdr user_icmph; 704 struct pingfakehdr pfh; 705 struct rtable *rt = NULL; 706 struct ip_options_data opt_copy; 707 int free = 0; 708 __be32 saddr, daddr, faddr; 709 u8 tos; 710 int err; 711 712 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 713 714 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 715 sizeof(user_icmph)); 716 if (err) 717 return err; 718 719 /* 720 * Get and verify the address. 721 */ 722 723 if (msg->msg_name) { 724 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 725 if (msg->msg_namelen < sizeof(*usin)) 726 return -EINVAL; 727 if (usin->sin_family != AF_INET) 728 return -EAFNOSUPPORT; 729 daddr = usin->sin_addr.s_addr; 730 /* no remote port */ 731 } else { 732 if (sk->sk_state != TCP_ESTABLISHED) 733 return -EDESTADDRREQ; 734 daddr = inet->inet_daddr; 735 /* no remote port */ 736 } 737 738 ipc.addr = inet->inet_saddr; 739 ipc.opt = NULL; 740 ipc.oif = sk->sk_bound_dev_if; 741 ipc.tx_flags = 0; 742 ipc.ttl = 0; 743 ipc.tos = -1; 744 745 sock_tx_timestamp(sk, &ipc.tx_flags); 746 747 if (msg->msg_controllen) { 748 err = ip_cmsg_send(sock_net(sk), msg, &ipc, false); 749 if (err) 750 return err; 751 if (ipc.opt) 752 free = 1; 753 } 754 if (!ipc.opt) { 755 struct ip_options_rcu *inet_opt; 756 757 rcu_read_lock(); 758 inet_opt = rcu_dereference(inet->inet_opt); 759 if (inet_opt) { 760 memcpy(&opt_copy, inet_opt, 761 sizeof(*inet_opt) + inet_opt->opt.optlen); 762 ipc.opt = &opt_copy.opt; 763 } 764 rcu_read_unlock(); 765 } 766 767 saddr = ipc.addr; 768 ipc.addr = faddr = daddr; 769 770 if (ipc.opt && ipc.opt->opt.srr) { 771 if (!daddr) 772 return -EINVAL; 773 faddr = ipc.opt->opt.faddr; 774 } 775 tos = get_rttos(&ipc, inet); 776 if (sock_flag(sk, SOCK_LOCALROUTE) || 777 (msg->msg_flags & MSG_DONTROUTE) || 778 (ipc.opt && ipc.opt->opt.is_strictroute)) { 779 tos |= RTO_ONLINK; 780 } 781 782 if (ipv4_is_multicast(daddr)) { 783 if (!ipc.oif) 784 ipc.oif = inet->mc_index; 785 if (!saddr) 786 saddr = inet->mc_addr; 787 } else if (!ipc.oif) 788 ipc.oif = inet->uc_index; 789 790 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos, 791 RT_SCOPE_UNIVERSE, sk->sk_protocol, 792 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0); 793 794 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 795 rt = ip_route_output_flow(net, &fl4, sk); 796 if (IS_ERR(rt)) { 797 err = PTR_ERR(rt); 798 rt = NULL; 799 if (err == -ENETUNREACH) 800 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 801 goto out; 802 } 803 804 err = -EACCES; 805 if ((rt->rt_flags & RTCF_BROADCAST) && 806 !sock_flag(sk, SOCK_BROADCAST)) 807 goto out; 808 809 if (msg->msg_flags & MSG_CONFIRM) 810 goto do_confirm; 811 back_from_confirm: 812 813 if (!ipc.addr) 814 ipc.addr = fl4.daddr; 815 816 lock_sock(sk); 817 818 pfh.icmph.type = user_icmph.type; /* already checked */ 819 pfh.icmph.code = user_icmph.code; /* ditto */ 820 pfh.icmph.checksum = 0; 821 pfh.icmph.un.echo.id = inet->inet_sport; 822 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 823 pfh.msg = msg; 824 pfh.wcheck = 0; 825 pfh.family = AF_INET; 826 827 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 828 0, &ipc, &rt, msg->msg_flags); 829 if (err) 830 ip_flush_pending_frames(sk); 831 else 832 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 833 release_sock(sk); 834 835 out: 836 ip_rt_put(rt); 837 if (free) 838 kfree(ipc.opt); 839 if (!err) { 840 icmp_out_count(sock_net(sk), user_icmph.type); 841 return len; 842 } 843 return err; 844 845 do_confirm: 846 dst_confirm(&rt->dst); 847 if (!(msg->msg_flags & MSG_PROBE) || len) 848 goto back_from_confirm; 849 err = 0; 850 goto out; 851 } 852 853 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 854 int flags, int *addr_len) 855 { 856 struct inet_sock *isk = inet_sk(sk); 857 int family = sk->sk_family; 858 struct sk_buff *skb; 859 int copied, err; 860 861 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 862 863 err = -EOPNOTSUPP; 864 if (flags & MSG_OOB) 865 goto out; 866 867 if (flags & MSG_ERRQUEUE) 868 return inet_recv_error(sk, msg, len, addr_len); 869 870 skb = skb_recv_datagram(sk, flags, noblock, &err); 871 if (!skb) 872 goto out; 873 874 copied = skb->len; 875 if (copied > len) { 876 msg->msg_flags |= MSG_TRUNC; 877 copied = len; 878 } 879 880 /* Don't bother checking the checksum */ 881 err = skb_copy_datagram_msg(skb, 0, msg, copied); 882 if (err) 883 goto done; 884 885 sock_recv_timestamp(msg, sk, skb); 886 887 /* Copy the address and add cmsg data. */ 888 if (family == AF_INET) { 889 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 890 891 if (sin) { 892 sin->sin_family = AF_INET; 893 sin->sin_port = 0 /* skb->h.uh->source */; 894 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 895 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 896 *addr_len = sizeof(*sin); 897 } 898 899 if (isk->cmsg_flags) 900 ip_cmsg_recv(msg, skb); 901 902 #if IS_ENABLED(CONFIG_IPV6) 903 } else if (family == AF_INET6) { 904 struct ipv6_pinfo *np = inet6_sk(sk); 905 struct ipv6hdr *ip6 = ipv6_hdr(skb); 906 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 907 908 if (sin6) { 909 sin6->sin6_family = AF_INET6; 910 sin6->sin6_port = 0; 911 sin6->sin6_addr = ip6->saddr; 912 sin6->sin6_flowinfo = 0; 913 if (np->sndflow) 914 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 915 sin6->sin6_scope_id = 916 ipv6_iface_scope_id(&sin6->sin6_addr, 917 inet6_iif(skb)); 918 *addr_len = sizeof(*sin6); 919 } 920 921 if (inet6_sk(sk)->rxopt.all) 922 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 923 if (skb->protocol == htons(ETH_P_IPV6) && 924 inet6_sk(sk)->rxopt.all) 925 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 926 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 927 ip_cmsg_recv(msg, skb); 928 #endif 929 } else { 930 BUG(); 931 } 932 933 err = copied; 934 935 done: 936 skb_free_datagram(sk, skb); 937 out: 938 pr_debug("ping_recvmsg -> %d\n", err); 939 return err; 940 } 941 EXPORT_SYMBOL_GPL(ping_recvmsg); 942 943 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 944 { 945 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 946 inet_sk(sk), inet_sk(sk)->inet_num, skb); 947 if (sock_queue_rcv_skb(sk, skb) < 0) { 948 kfree_skb(skb); 949 pr_debug("ping_queue_rcv_skb -> failed\n"); 950 return -1; 951 } 952 return 0; 953 } 954 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 955 956 957 /* 958 * All we need to do is get the socket. 959 */ 960 961 bool ping_rcv(struct sk_buff *skb) 962 { 963 struct sock *sk; 964 struct net *net = dev_net(skb->dev); 965 struct icmphdr *icmph = icmp_hdr(skb); 966 967 /* We assume the packet has already been checked by icmp_rcv */ 968 969 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 970 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 971 972 /* Push ICMP header back */ 973 skb_push(skb, skb->data - (u8 *)icmph); 974 975 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 976 if (sk) { 977 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 978 979 pr_debug("rcv on socket %p\n", sk); 980 if (skb2) 981 ping_queue_rcv_skb(sk, skb2); 982 sock_put(sk); 983 return true; 984 } 985 pr_debug("no socket, dropping\n"); 986 987 return false; 988 } 989 EXPORT_SYMBOL_GPL(ping_rcv); 990 991 struct proto ping_prot = { 992 .name = "PING", 993 .owner = THIS_MODULE, 994 .init = ping_init_sock, 995 .close = ping_close, 996 .connect = ip4_datagram_connect, 997 .disconnect = udp_disconnect, 998 .setsockopt = ip_setsockopt, 999 .getsockopt = ip_getsockopt, 1000 .sendmsg = ping_v4_sendmsg, 1001 .recvmsg = ping_recvmsg, 1002 .bind = ping_bind, 1003 .backlog_rcv = ping_queue_rcv_skb, 1004 .release_cb = ip4_datagram_release_cb, 1005 .hash = ping_hash, 1006 .unhash = ping_unhash, 1007 .get_port = ping_get_port, 1008 .obj_size = sizeof(struct inet_sock), 1009 }; 1010 EXPORT_SYMBOL(ping_prot); 1011 1012 #ifdef CONFIG_PROC_FS 1013 1014 static struct sock *ping_get_first(struct seq_file *seq, int start) 1015 { 1016 struct sock *sk; 1017 struct ping_iter_state *state = seq->private; 1018 struct net *net = seq_file_net(seq); 1019 1020 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1021 ++state->bucket) { 1022 struct hlist_nulls_node *node; 1023 struct hlist_nulls_head *hslot; 1024 1025 hslot = &ping_table.hash[state->bucket]; 1026 1027 if (hlist_nulls_empty(hslot)) 1028 continue; 1029 1030 sk_nulls_for_each(sk, node, hslot) { 1031 if (net_eq(sock_net(sk), net) && 1032 sk->sk_family == state->family) 1033 goto found; 1034 } 1035 } 1036 sk = NULL; 1037 found: 1038 return sk; 1039 } 1040 1041 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1042 { 1043 struct ping_iter_state *state = seq->private; 1044 struct net *net = seq_file_net(seq); 1045 1046 do { 1047 sk = sk_nulls_next(sk); 1048 } while (sk && (!net_eq(sock_net(sk), net))); 1049 1050 if (!sk) 1051 return ping_get_first(seq, state->bucket + 1); 1052 return sk; 1053 } 1054 1055 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1056 { 1057 struct sock *sk = ping_get_first(seq, 0); 1058 1059 if (sk) 1060 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1061 --pos; 1062 return pos ? NULL : sk; 1063 } 1064 1065 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1066 { 1067 struct ping_iter_state *state = seq->private; 1068 state->bucket = 0; 1069 state->family = family; 1070 1071 read_lock_bh(&ping_table.lock); 1072 1073 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1074 } 1075 EXPORT_SYMBOL_GPL(ping_seq_start); 1076 1077 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1078 { 1079 return ping_seq_start(seq, pos, AF_INET); 1080 } 1081 1082 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1083 { 1084 struct sock *sk; 1085 1086 if (v == SEQ_START_TOKEN) 1087 sk = ping_get_idx(seq, 0); 1088 else 1089 sk = ping_get_next(seq, v); 1090 1091 ++*pos; 1092 return sk; 1093 } 1094 EXPORT_SYMBOL_GPL(ping_seq_next); 1095 1096 void ping_seq_stop(struct seq_file *seq, void *v) 1097 { 1098 read_unlock_bh(&ping_table.lock); 1099 } 1100 EXPORT_SYMBOL_GPL(ping_seq_stop); 1101 1102 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1103 int bucket) 1104 { 1105 struct inet_sock *inet = inet_sk(sp); 1106 __be32 dest = inet->inet_daddr; 1107 __be32 src = inet->inet_rcv_saddr; 1108 __u16 destp = ntohs(inet->inet_dport); 1109 __u16 srcp = ntohs(inet->inet_sport); 1110 1111 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1112 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 1113 bucket, src, srcp, dest, destp, sp->sk_state, 1114 sk_wmem_alloc_get(sp), 1115 sk_rmem_alloc_get(sp), 1116 0, 0L, 0, 1117 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1118 0, sock_i_ino(sp), 1119 atomic_read(&sp->sk_refcnt), sp, 1120 atomic_read(&sp->sk_drops)); 1121 } 1122 1123 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1124 { 1125 seq_setwidth(seq, 127); 1126 if (v == SEQ_START_TOKEN) 1127 seq_puts(seq, " sl local_address rem_address st tx_queue " 1128 "rx_queue tr tm->when retrnsmt uid timeout " 1129 "inode ref pointer drops"); 1130 else { 1131 struct ping_iter_state *state = seq->private; 1132 1133 ping_v4_format_sock(v, seq, state->bucket); 1134 } 1135 seq_pad(seq, '\n'); 1136 return 0; 1137 } 1138 1139 static const struct seq_operations ping_v4_seq_ops = { 1140 .show = ping_v4_seq_show, 1141 .start = ping_v4_seq_start, 1142 .next = ping_seq_next, 1143 .stop = ping_seq_stop, 1144 }; 1145 1146 static int ping_seq_open(struct inode *inode, struct file *file) 1147 { 1148 struct ping_seq_afinfo *afinfo = PDE_DATA(inode); 1149 return seq_open_net(inode, file, &afinfo->seq_ops, 1150 sizeof(struct ping_iter_state)); 1151 } 1152 1153 const struct file_operations ping_seq_fops = { 1154 .open = ping_seq_open, 1155 .read = seq_read, 1156 .llseek = seq_lseek, 1157 .release = seq_release_net, 1158 }; 1159 EXPORT_SYMBOL_GPL(ping_seq_fops); 1160 1161 static struct ping_seq_afinfo ping_v4_seq_afinfo = { 1162 .name = "icmp", 1163 .family = AF_INET, 1164 .seq_fops = &ping_seq_fops, 1165 .seq_ops = { 1166 .start = ping_v4_seq_start, 1167 .show = ping_v4_seq_show, 1168 .next = ping_seq_next, 1169 .stop = ping_seq_stop, 1170 }, 1171 }; 1172 1173 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo) 1174 { 1175 struct proc_dir_entry *p; 1176 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 1177 afinfo->seq_fops, afinfo); 1178 if (!p) 1179 return -ENOMEM; 1180 return 0; 1181 } 1182 EXPORT_SYMBOL_GPL(ping_proc_register); 1183 1184 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo) 1185 { 1186 remove_proc_entry(afinfo->name, net->proc_net); 1187 } 1188 EXPORT_SYMBOL_GPL(ping_proc_unregister); 1189 1190 static int __net_init ping_v4_proc_init_net(struct net *net) 1191 { 1192 return ping_proc_register(net, &ping_v4_seq_afinfo); 1193 } 1194 1195 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1196 { 1197 ping_proc_unregister(net, &ping_v4_seq_afinfo); 1198 } 1199 1200 static struct pernet_operations ping_v4_net_ops = { 1201 .init = ping_v4_proc_init_net, 1202 .exit = ping_v4_proc_exit_net, 1203 }; 1204 1205 int __init ping_proc_init(void) 1206 { 1207 return register_pernet_subsys(&ping_v4_net_ops); 1208 } 1209 1210 void ping_proc_exit(void) 1211 { 1212 unregister_pernet_subsys(&ping_v4_net_ops); 1213 } 1214 1215 #endif 1216 1217 void __init ping_init(void) 1218 { 1219 int i; 1220 1221 for (i = 0; i < PING_HTABLE_SIZE; i++) 1222 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1223 rwlock_init(&ping_table.lock); 1224 } 1225