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 (!(isk->freebind || isk->transparent || has_addr || 367 addr_type == IPV6_ADDR_ANY)) 368 return -EADDRNOTAVAIL; 369 370 if (scoped) 371 sk->sk_bound_dev_if = addr->sin6_scope_id; 372 #endif 373 } else { 374 return -EAFNOSUPPORT; 375 } 376 return 0; 377 } 378 379 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 380 { 381 if (saddr->sa_family == AF_INET) { 382 struct inet_sock *isk = inet_sk(sk); 383 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 384 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 385 #if IS_ENABLED(CONFIG_IPV6) 386 } else if (saddr->sa_family == AF_INET6) { 387 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 388 struct ipv6_pinfo *np = inet6_sk(sk); 389 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 390 #endif 391 } 392 } 393 394 static void ping_clear_saddr(struct sock *sk, int dif) 395 { 396 sk->sk_bound_dev_if = dif; 397 if (sk->sk_family == AF_INET) { 398 struct inet_sock *isk = inet_sk(sk); 399 isk->inet_rcv_saddr = isk->inet_saddr = 0; 400 #if IS_ENABLED(CONFIG_IPV6) 401 } else if (sk->sk_family == AF_INET6) { 402 struct ipv6_pinfo *np = inet6_sk(sk); 403 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 404 memset(&np->saddr, 0, sizeof(np->saddr)); 405 #endif 406 } 407 } 408 /* 409 * We need our own bind because there are no privileged id's == local ports. 410 * Moreover, we don't allow binding to multi- and broadcast addresses. 411 */ 412 413 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 414 { 415 struct inet_sock *isk = inet_sk(sk); 416 unsigned short snum; 417 int err; 418 int dif = sk->sk_bound_dev_if; 419 420 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 421 if (err) 422 return err; 423 424 lock_sock(sk); 425 426 err = -EINVAL; 427 if (isk->inet_num != 0) 428 goto out; 429 430 err = -EADDRINUSE; 431 ping_set_saddr(sk, uaddr); 432 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 433 if (ping_get_port(sk, snum) != 0) { 434 ping_clear_saddr(sk, dif); 435 goto out; 436 } 437 438 pr_debug("after bind(): num = %d, dif = %d\n", 439 (int)isk->inet_num, 440 (int)sk->sk_bound_dev_if); 441 442 err = 0; 443 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 444 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 445 #if IS_ENABLED(CONFIG_IPV6) 446 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 447 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 448 #endif 449 450 if (snum) 451 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 452 isk->inet_sport = htons(isk->inet_num); 453 isk->inet_daddr = 0; 454 isk->inet_dport = 0; 455 456 #if IS_ENABLED(CONFIG_IPV6) 457 if (sk->sk_family == AF_INET6) 458 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 459 #endif 460 461 sk_dst_reset(sk); 462 out: 463 release_sock(sk); 464 pr_debug("ping_v4_bind -> %d\n", err); 465 return err; 466 } 467 EXPORT_SYMBOL_GPL(ping_bind); 468 469 /* 470 * Is this a supported type of ICMP message? 471 */ 472 473 static inline int ping_supported(int family, int type, int code) 474 { 475 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 476 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0); 477 } 478 479 /* 480 * This routine is called by the ICMP module when it gets some 481 * sort of error condition. 482 */ 483 484 void ping_err(struct sk_buff *skb, int offset, u32 info) 485 { 486 int family; 487 struct icmphdr *icmph; 488 struct inet_sock *inet_sock; 489 int type; 490 int code; 491 struct net *net = dev_net(skb->dev); 492 struct sock *sk; 493 int harderr; 494 int err; 495 496 if (skb->protocol == htons(ETH_P_IP)) { 497 family = AF_INET; 498 type = icmp_hdr(skb)->type; 499 code = icmp_hdr(skb)->code; 500 icmph = (struct icmphdr *)(skb->data + offset); 501 } else if (skb->protocol == htons(ETH_P_IPV6)) { 502 family = AF_INET6; 503 type = icmp6_hdr(skb)->icmp6_type; 504 code = icmp6_hdr(skb)->icmp6_code; 505 icmph = (struct icmphdr *) (skb->data + offset); 506 } else { 507 BUG(); 508 } 509 510 /* We assume the packet has already been checked by icmp_unreach */ 511 512 if (!ping_supported(family, icmph->type, icmph->code)) 513 return; 514 515 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 516 skb->protocol, type, code, ntohs(icmph->un.echo.id), 517 ntohs(icmph->un.echo.sequence)); 518 519 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 520 if (!sk) { 521 pr_debug("no socket, dropping\n"); 522 return; /* No socket for error */ 523 } 524 pr_debug("err on socket %p\n", sk); 525 526 err = 0; 527 harderr = 0; 528 inet_sock = inet_sk(sk); 529 530 if (skb->protocol == htons(ETH_P_IP)) { 531 switch (type) { 532 default: 533 case ICMP_TIME_EXCEEDED: 534 err = EHOSTUNREACH; 535 break; 536 case ICMP_SOURCE_QUENCH: 537 /* This is not a real error but ping wants to see it. 538 * Report it with some fake errno. 539 */ 540 err = EREMOTEIO; 541 break; 542 case ICMP_PARAMETERPROB: 543 err = EPROTO; 544 harderr = 1; 545 break; 546 case ICMP_DEST_UNREACH: 547 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 548 ipv4_sk_update_pmtu(skb, sk, info); 549 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 550 err = EMSGSIZE; 551 harderr = 1; 552 break; 553 } 554 goto out; 555 } 556 err = EHOSTUNREACH; 557 if (code <= NR_ICMP_UNREACH) { 558 harderr = icmp_err_convert[code].fatal; 559 err = icmp_err_convert[code].errno; 560 } 561 break; 562 case ICMP_REDIRECT: 563 /* See ICMP_SOURCE_QUENCH */ 564 ipv4_sk_redirect(skb, sk); 565 err = EREMOTEIO; 566 break; 567 } 568 #if IS_ENABLED(CONFIG_IPV6) 569 } else if (skb->protocol == htons(ETH_P_IPV6)) { 570 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 571 #endif 572 } 573 574 /* 575 * RFC1122: OK. Passes ICMP errors back to application, as per 576 * 4.1.3.3. 577 */ 578 if ((family == AF_INET && !inet_sock->recverr) || 579 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 580 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 581 goto out; 582 } else { 583 if (family == AF_INET) { 584 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 585 info, (u8 *)icmph); 586 #if IS_ENABLED(CONFIG_IPV6) 587 } else if (family == AF_INET6) { 588 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 589 info, (u8 *)icmph); 590 #endif 591 } 592 } 593 sk->sk_err = err; 594 sk->sk_error_report(sk); 595 out: 596 sock_put(sk); 597 } 598 EXPORT_SYMBOL_GPL(ping_err); 599 600 /* 601 * Copy and checksum an ICMP Echo packet from user space into a buffer 602 * starting from the payload. 603 */ 604 605 int ping_getfrag(void *from, char *to, 606 int offset, int fraglen, int odd, struct sk_buff *skb) 607 { 608 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 609 610 if (offset == 0) { 611 fraglen -= sizeof(struct icmphdr); 612 if (fraglen < 0) 613 BUG(); 614 if (csum_and_copy_from_iter(to + sizeof(struct icmphdr), 615 fraglen, &pfh->wcheck, 616 &pfh->msg->msg_iter) != fraglen) 617 return -EFAULT; 618 } else if (offset < sizeof(struct icmphdr)) { 619 BUG(); 620 } else { 621 if (csum_and_copy_from_iter(to, fraglen, &pfh->wcheck, 622 &pfh->msg->msg_iter) != fraglen) 623 return -EFAULT; 624 } 625 626 #if IS_ENABLED(CONFIG_IPV6) 627 /* For IPv6, checksum each skb as we go along, as expected by 628 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 629 * wcheck, it will be finalized in ping_v4_push_pending_frames. 630 */ 631 if (pfh->family == AF_INET6) { 632 skb->csum = pfh->wcheck; 633 skb->ip_summed = CHECKSUM_NONE; 634 pfh->wcheck = 0; 635 } 636 #endif 637 638 return 0; 639 } 640 EXPORT_SYMBOL_GPL(ping_getfrag); 641 642 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 643 struct flowi4 *fl4) 644 { 645 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 646 647 pfh->wcheck = csum_partial((char *)&pfh->icmph, 648 sizeof(struct icmphdr), pfh->wcheck); 649 pfh->icmph.checksum = csum_fold(pfh->wcheck); 650 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 651 skb->ip_summed = CHECKSUM_NONE; 652 return ip_push_pending_frames(sk, fl4); 653 } 654 655 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 656 void *user_icmph, size_t icmph_len) { 657 u8 type, code; 658 659 if (len > 0xFFFF) 660 return -EMSGSIZE; 661 662 /* 663 * Check the flags. 664 */ 665 666 /* Mirror BSD error message compatibility */ 667 if (msg->msg_flags & MSG_OOB) 668 return -EOPNOTSUPP; 669 670 /* 671 * Fetch the ICMP header provided by the userland. 672 * iovec is modified! The ICMP header is consumed. 673 */ 674 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 675 return -EFAULT; 676 677 if (family == AF_INET) { 678 type = ((struct icmphdr *) user_icmph)->type; 679 code = ((struct icmphdr *) user_icmph)->code; 680 #if IS_ENABLED(CONFIG_IPV6) 681 } else if (family == AF_INET6) { 682 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 683 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 684 #endif 685 } else { 686 BUG(); 687 } 688 689 if (!ping_supported(family, type, code)) 690 return -EINVAL; 691 692 return 0; 693 } 694 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 695 696 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 697 { 698 struct net *net = sock_net(sk); 699 struct flowi4 fl4; 700 struct inet_sock *inet = inet_sk(sk); 701 struct ipcm_cookie ipc; 702 struct icmphdr user_icmph; 703 struct pingfakehdr pfh; 704 struct rtable *rt = NULL; 705 struct ip_options_data opt_copy; 706 int free = 0; 707 __be32 saddr, daddr, faddr; 708 u8 tos; 709 int err; 710 711 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 712 713 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 714 sizeof(user_icmph)); 715 if (err) 716 return err; 717 718 /* 719 * Get and verify the address. 720 */ 721 722 if (msg->msg_name) { 723 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 724 if (msg->msg_namelen < sizeof(*usin)) 725 return -EINVAL; 726 if (usin->sin_family != AF_INET) 727 return -EAFNOSUPPORT; 728 daddr = usin->sin_addr.s_addr; 729 /* no remote port */ 730 } else { 731 if (sk->sk_state != TCP_ESTABLISHED) 732 return -EDESTADDRREQ; 733 daddr = inet->inet_daddr; 734 /* no remote port */ 735 } 736 737 ipc.addr = inet->inet_saddr; 738 ipc.opt = NULL; 739 ipc.oif = sk->sk_bound_dev_if; 740 ipc.tx_flags = 0; 741 ipc.ttl = 0; 742 ipc.tos = -1; 743 744 sock_tx_timestamp(sk, &ipc.tx_flags); 745 746 if (msg->msg_controllen) { 747 err = ip_cmsg_send(sock_net(sk), msg, &ipc, false); 748 if (err) 749 return err; 750 if (ipc.opt) 751 free = 1; 752 } 753 if (!ipc.opt) { 754 struct ip_options_rcu *inet_opt; 755 756 rcu_read_lock(); 757 inet_opt = rcu_dereference(inet->inet_opt); 758 if (inet_opt) { 759 memcpy(&opt_copy, inet_opt, 760 sizeof(*inet_opt) + inet_opt->opt.optlen); 761 ipc.opt = &opt_copy.opt; 762 } 763 rcu_read_unlock(); 764 } 765 766 saddr = ipc.addr; 767 ipc.addr = faddr = daddr; 768 769 if (ipc.opt && ipc.opt->opt.srr) { 770 if (!daddr) 771 return -EINVAL; 772 faddr = ipc.opt->opt.faddr; 773 } 774 tos = get_rttos(&ipc, inet); 775 if (sock_flag(sk, SOCK_LOCALROUTE) || 776 (msg->msg_flags & MSG_DONTROUTE) || 777 (ipc.opt && ipc.opt->opt.is_strictroute)) { 778 tos |= RTO_ONLINK; 779 } 780 781 if (ipv4_is_multicast(daddr)) { 782 if (!ipc.oif) 783 ipc.oif = inet->mc_index; 784 if (!saddr) 785 saddr = inet->mc_addr; 786 } else if (!ipc.oif) 787 ipc.oif = inet->uc_index; 788 789 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos, 790 RT_SCOPE_UNIVERSE, sk->sk_protocol, 791 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0); 792 793 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 794 rt = ip_route_output_flow(net, &fl4, sk); 795 if (IS_ERR(rt)) { 796 err = PTR_ERR(rt); 797 rt = NULL; 798 if (err == -ENETUNREACH) 799 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 800 goto out; 801 } 802 803 err = -EACCES; 804 if ((rt->rt_flags & RTCF_BROADCAST) && 805 !sock_flag(sk, SOCK_BROADCAST)) 806 goto out; 807 808 if (msg->msg_flags & MSG_CONFIRM) 809 goto do_confirm; 810 back_from_confirm: 811 812 if (!ipc.addr) 813 ipc.addr = fl4.daddr; 814 815 lock_sock(sk); 816 817 pfh.icmph.type = user_icmph.type; /* already checked */ 818 pfh.icmph.code = user_icmph.code; /* ditto */ 819 pfh.icmph.checksum = 0; 820 pfh.icmph.un.echo.id = inet->inet_sport; 821 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 822 pfh.msg = msg; 823 pfh.wcheck = 0; 824 pfh.family = AF_INET; 825 826 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 827 0, &ipc, &rt, msg->msg_flags); 828 if (err) 829 ip_flush_pending_frames(sk); 830 else 831 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 832 release_sock(sk); 833 834 out: 835 ip_rt_put(rt); 836 if (free) 837 kfree(ipc.opt); 838 if (!err) { 839 icmp_out_count(sock_net(sk), user_icmph.type); 840 return len; 841 } 842 return err; 843 844 do_confirm: 845 dst_confirm(&rt->dst); 846 if (!(msg->msg_flags & MSG_PROBE) || len) 847 goto back_from_confirm; 848 err = 0; 849 goto out; 850 } 851 852 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 853 int flags, int *addr_len) 854 { 855 struct inet_sock *isk = inet_sk(sk); 856 int family = sk->sk_family; 857 struct sk_buff *skb; 858 int copied, err; 859 860 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 861 862 err = -EOPNOTSUPP; 863 if (flags & MSG_OOB) 864 goto out; 865 866 if (flags & MSG_ERRQUEUE) 867 return inet_recv_error(sk, msg, len, addr_len); 868 869 skb = skb_recv_datagram(sk, flags, noblock, &err); 870 if (!skb) 871 goto out; 872 873 copied = skb->len; 874 if (copied > len) { 875 msg->msg_flags |= MSG_TRUNC; 876 copied = len; 877 } 878 879 /* Don't bother checking the checksum */ 880 err = skb_copy_datagram_msg(skb, 0, msg, copied); 881 if (err) 882 goto done; 883 884 sock_recv_timestamp(msg, sk, skb); 885 886 /* Copy the address and add cmsg data. */ 887 if (family == AF_INET) { 888 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 889 890 if (sin) { 891 sin->sin_family = AF_INET; 892 sin->sin_port = 0 /* skb->h.uh->source */; 893 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 894 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 895 *addr_len = sizeof(*sin); 896 } 897 898 if (isk->cmsg_flags) 899 ip_cmsg_recv(msg, skb); 900 901 #if IS_ENABLED(CONFIG_IPV6) 902 } else if (family == AF_INET6) { 903 struct ipv6_pinfo *np = inet6_sk(sk); 904 struct ipv6hdr *ip6 = ipv6_hdr(skb); 905 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 906 907 if (sin6) { 908 sin6->sin6_family = AF_INET6; 909 sin6->sin6_port = 0; 910 sin6->sin6_addr = ip6->saddr; 911 sin6->sin6_flowinfo = 0; 912 if (np->sndflow) 913 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 914 sin6->sin6_scope_id = 915 ipv6_iface_scope_id(&sin6->sin6_addr, 916 inet6_iif(skb)); 917 *addr_len = sizeof(*sin6); 918 } 919 920 if (inet6_sk(sk)->rxopt.all) 921 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 922 if (skb->protocol == htons(ETH_P_IPV6) && 923 inet6_sk(sk)->rxopt.all) 924 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 925 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 926 ip_cmsg_recv(msg, skb); 927 #endif 928 } else { 929 BUG(); 930 } 931 932 err = copied; 933 934 done: 935 skb_free_datagram(sk, skb); 936 out: 937 pr_debug("ping_recvmsg -> %d\n", err); 938 return err; 939 } 940 EXPORT_SYMBOL_GPL(ping_recvmsg); 941 942 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 943 { 944 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 945 inet_sk(sk), inet_sk(sk)->inet_num, skb); 946 if (sock_queue_rcv_skb(sk, skb) < 0) { 947 kfree_skb(skb); 948 pr_debug("ping_queue_rcv_skb -> failed\n"); 949 return -1; 950 } 951 return 0; 952 } 953 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 954 955 956 /* 957 * All we need to do is get the socket. 958 */ 959 960 bool ping_rcv(struct sk_buff *skb) 961 { 962 struct sock *sk; 963 struct net *net = dev_net(skb->dev); 964 struct icmphdr *icmph = icmp_hdr(skb); 965 966 /* We assume the packet has already been checked by icmp_rcv */ 967 968 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 969 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 970 971 /* Push ICMP header back */ 972 skb_push(skb, skb->data - (u8 *)icmph); 973 974 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 975 if (sk) { 976 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 977 978 pr_debug("rcv on socket %p\n", sk); 979 if (skb2) 980 ping_queue_rcv_skb(sk, skb2); 981 sock_put(sk); 982 return true; 983 } 984 pr_debug("no socket, dropping\n"); 985 986 return false; 987 } 988 EXPORT_SYMBOL_GPL(ping_rcv); 989 990 struct proto ping_prot = { 991 .name = "PING", 992 .owner = THIS_MODULE, 993 .init = ping_init_sock, 994 .close = ping_close, 995 .connect = ip4_datagram_connect, 996 .disconnect = udp_disconnect, 997 .setsockopt = ip_setsockopt, 998 .getsockopt = ip_getsockopt, 999 .sendmsg = ping_v4_sendmsg, 1000 .recvmsg = ping_recvmsg, 1001 .bind = ping_bind, 1002 .backlog_rcv = ping_queue_rcv_skb, 1003 .release_cb = ip4_datagram_release_cb, 1004 .hash = ping_hash, 1005 .unhash = ping_unhash, 1006 .get_port = ping_get_port, 1007 .obj_size = sizeof(struct inet_sock), 1008 }; 1009 EXPORT_SYMBOL(ping_prot); 1010 1011 #ifdef CONFIG_PROC_FS 1012 1013 static struct sock *ping_get_first(struct seq_file *seq, int start) 1014 { 1015 struct sock *sk; 1016 struct ping_iter_state *state = seq->private; 1017 struct net *net = seq_file_net(seq); 1018 1019 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1020 ++state->bucket) { 1021 struct hlist_nulls_node *node; 1022 struct hlist_nulls_head *hslot; 1023 1024 hslot = &ping_table.hash[state->bucket]; 1025 1026 if (hlist_nulls_empty(hslot)) 1027 continue; 1028 1029 sk_nulls_for_each(sk, node, hslot) { 1030 if (net_eq(sock_net(sk), net) && 1031 sk->sk_family == state->family) 1032 goto found; 1033 } 1034 } 1035 sk = NULL; 1036 found: 1037 return sk; 1038 } 1039 1040 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1041 { 1042 struct ping_iter_state *state = seq->private; 1043 struct net *net = seq_file_net(seq); 1044 1045 do { 1046 sk = sk_nulls_next(sk); 1047 } while (sk && (!net_eq(sock_net(sk), net))); 1048 1049 if (!sk) 1050 return ping_get_first(seq, state->bucket + 1); 1051 return sk; 1052 } 1053 1054 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1055 { 1056 struct sock *sk = ping_get_first(seq, 0); 1057 1058 if (sk) 1059 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1060 --pos; 1061 return pos ? NULL : sk; 1062 } 1063 1064 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1065 { 1066 struct ping_iter_state *state = seq->private; 1067 state->bucket = 0; 1068 state->family = family; 1069 1070 read_lock_bh(&ping_table.lock); 1071 1072 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1073 } 1074 EXPORT_SYMBOL_GPL(ping_seq_start); 1075 1076 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1077 { 1078 return ping_seq_start(seq, pos, AF_INET); 1079 } 1080 1081 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1082 { 1083 struct sock *sk; 1084 1085 if (v == SEQ_START_TOKEN) 1086 sk = ping_get_idx(seq, 0); 1087 else 1088 sk = ping_get_next(seq, v); 1089 1090 ++*pos; 1091 return sk; 1092 } 1093 EXPORT_SYMBOL_GPL(ping_seq_next); 1094 1095 void ping_seq_stop(struct seq_file *seq, void *v) 1096 { 1097 read_unlock_bh(&ping_table.lock); 1098 } 1099 EXPORT_SYMBOL_GPL(ping_seq_stop); 1100 1101 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1102 int bucket) 1103 { 1104 struct inet_sock *inet = inet_sk(sp); 1105 __be32 dest = inet->inet_daddr; 1106 __be32 src = inet->inet_rcv_saddr; 1107 __u16 destp = ntohs(inet->inet_dport); 1108 __u16 srcp = ntohs(inet->inet_sport); 1109 1110 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1111 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 1112 bucket, src, srcp, dest, destp, sp->sk_state, 1113 sk_wmem_alloc_get(sp), 1114 sk_rmem_alloc_get(sp), 1115 0, 0L, 0, 1116 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1117 0, sock_i_ino(sp), 1118 atomic_read(&sp->sk_refcnt), sp, 1119 atomic_read(&sp->sk_drops)); 1120 } 1121 1122 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1123 { 1124 seq_setwidth(seq, 127); 1125 if (v == SEQ_START_TOKEN) 1126 seq_puts(seq, " sl local_address rem_address st tx_queue " 1127 "rx_queue tr tm->when retrnsmt uid timeout " 1128 "inode ref pointer drops"); 1129 else { 1130 struct ping_iter_state *state = seq->private; 1131 1132 ping_v4_format_sock(v, seq, state->bucket); 1133 } 1134 seq_pad(seq, '\n'); 1135 return 0; 1136 } 1137 1138 static const struct seq_operations ping_v4_seq_ops = { 1139 .show = ping_v4_seq_show, 1140 .start = ping_v4_seq_start, 1141 .next = ping_seq_next, 1142 .stop = ping_seq_stop, 1143 }; 1144 1145 static int ping_seq_open(struct inode *inode, struct file *file) 1146 { 1147 struct ping_seq_afinfo *afinfo = PDE_DATA(inode); 1148 return seq_open_net(inode, file, &afinfo->seq_ops, 1149 sizeof(struct ping_iter_state)); 1150 } 1151 1152 const struct file_operations ping_seq_fops = { 1153 .open = ping_seq_open, 1154 .read = seq_read, 1155 .llseek = seq_lseek, 1156 .release = seq_release_net, 1157 }; 1158 EXPORT_SYMBOL_GPL(ping_seq_fops); 1159 1160 static struct ping_seq_afinfo ping_v4_seq_afinfo = { 1161 .name = "icmp", 1162 .family = AF_INET, 1163 .seq_fops = &ping_seq_fops, 1164 .seq_ops = { 1165 .start = ping_v4_seq_start, 1166 .show = ping_v4_seq_show, 1167 .next = ping_seq_next, 1168 .stop = ping_seq_stop, 1169 }, 1170 }; 1171 1172 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo) 1173 { 1174 struct proc_dir_entry *p; 1175 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 1176 afinfo->seq_fops, afinfo); 1177 if (!p) 1178 return -ENOMEM; 1179 return 0; 1180 } 1181 EXPORT_SYMBOL_GPL(ping_proc_register); 1182 1183 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo) 1184 { 1185 remove_proc_entry(afinfo->name, net->proc_net); 1186 } 1187 EXPORT_SYMBOL_GPL(ping_proc_unregister); 1188 1189 static int __net_init ping_v4_proc_init_net(struct net *net) 1190 { 1191 return ping_proc_register(net, &ping_v4_seq_afinfo); 1192 } 1193 1194 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1195 { 1196 ping_proc_unregister(net, &ping_v4_seq_afinfo); 1197 } 1198 1199 static struct pernet_operations ping_v4_net_ops = { 1200 .init = ping_v4_proc_init_net, 1201 .exit = ping_v4_proc_exit_net, 1202 }; 1203 1204 int __init ping_proc_init(void) 1205 { 1206 return register_pernet_subsys(&ping_v4_net_ops); 1207 } 1208 1209 void ping_proc_exit(void) 1210 { 1211 unregister_pernet_subsys(&ping_v4_net_ops); 1212 } 1213 1214 #endif 1215 1216 void __init ping_init(void) 1217 { 1218 int i; 1219 1220 for (i = 0; i < PING_HTABLE_SIZE; i++) 1221 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1222 rwlock_init(&ping_table.lock); 1223 } 1224