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