1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * "Ping" sockets 8 * 9 * Based on ipv4/udp.c code. 10 * 11 * Authors: Vasiliy Kulikov / Openwall (for Linux 2.6), 12 * Pavel Kankovsky (for Linux 2.4.32) 13 * 14 * Pavel gave all rights to bugs to Vasiliy, 15 * none of the bugs are Pavel's now. 16 */ 17 18 #include <linux/uaccess.h> 19 #include <linux/types.h> 20 #include <linux/fcntl.h> 21 #include <linux/socket.h> 22 #include <linux/sockios.h> 23 #include <linux/in.h> 24 #include <linux/errno.h> 25 #include <linux/timer.h> 26 #include <linux/mm.h> 27 #include <linux/inet.h> 28 #include <linux/netdevice.h> 29 #include <net/snmp.h> 30 #include <net/ip.h> 31 #include <net/icmp.h> 32 #include <net/protocol.h> 33 #include <linux/skbuff.h> 34 #include <linux/proc_fs.h> 35 #include <linux/export.h> 36 #include <linux/bpf-cgroup.h> 37 #include <net/sock.h> 38 #include <net/ping.h> 39 #include <net/udp.h> 40 #include <net/route.h> 41 #include <net/inet_common.h> 42 #include <net/checksum.h> 43 44 #if IS_ENABLED(CONFIG_IPV6) 45 #include <linux/in6.h> 46 #include <linux/icmpv6.h> 47 #include <net/addrconf.h> 48 #include <net/ipv6.h> 49 #include <net/transp_v6.h> 50 #endif 51 52 #define ping_portaddr_for_each_entry(__sk, node, list) \ 53 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node) 54 #define ping_portaddr_for_each_entry_rcu(__sk, node, list) \ 55 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node) 56 57 struct ping_table { 58 struct hlist_nulls_head hash[PING_HTABLE_SIZE]; 59 spinlock_t lock; 60 }; 61 62 static struct ping_table ping_table; 63 struct pingv6_ops pingv6_ops; 64 EXPORT_SYMBOL_GPL(pingv6_ops); 65 66 static u16 ping_port_rover; 67 68 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask) 69 { 70 u32 res = (num + net_hash_mix(net)) & mask; 71 72 pr_debug("hash(%u) = %u\n", num, res); 73 return res; 74 } 75 EXPORT_SYMBOL_GPL(ping_hash); 76 77 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table, 78 struct net *net, unsigned int num) 79 { 80 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)]; 81 } 82 83 int ping_get_port(struct sock *sk, unsigned short ident) 84 { 85 struct hlist_nulls_node *node; 86 struct hlist_nulls_head *hlist; 87 struct inet_sock *isk, *isk2; 88 struct sock *sk2 = NULL; 89 90 isk = inet_sk(sk); 91 spin_lock(&ping_table.lock); 92 if (ident == 0) { 93 u32 i; 94 u16 result = ping_port_rover + 1; 95 96 for (i = 0; i < (1L << 16); i++, result++) { 97 if (!result) 98 result++; /* avoid zero */ 99 hlist = ping_hashslot(&ping_table, sock_net(sk), 100 result); 101 ping_portaddr_for_each_entry(sk2, node, hlist) { 102 isk2 = inet_sk(sk2); 103 104 if (isk2->inet_num == result) 105 goto next_port; 106 } 107 108 /* found */ 109 ping_port_rover = ident = result; 110 break; 111 next_port: 112 ; 113 } 114 if (i >= (1L << 16)) 115 goto fail; 116 } else { 117 hlist = ping_hashslot(&ping_table, sock_net(sk), ident); 118 ping_portaddr_for_each_entry(sk2, node, hlist) { 119 isk2 = inet_sk(sk2); 120 121 /* BUG? Why is this reuse and not reuseaddr? ping.c 122 * doesn't turn off SO_REUSEADDR, and it doesn't expect 123 * that other ping processes can steal its packets. 124 */ 125 if ((isk2->inet_num == ident) && 126 (sk2 != sk) && 127 (!sk2->sk_reuse || !sk->sk_reuse)) 128 goto fail; 129 } 130 } 131 132 pr_debug("found port/ident = %d\n", ident); 133 isk->inet_num = ident; 134 if (sk_unhashed(sk)) { 135 pr_debug("was not hashed\n"); 136 sock_hold(sk); 137 sock_set_flag(sk, SOCK_RCU_FREE); 138 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, hlist); 139 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 140 } 141 spin_unlock(&ping_table.lock); 142 return 0; 143 144 fail: 145 spin_unlock(&ping_table.lock); 146 return -EADDRINUSE; 147 } 148 EXPORT_SYMBOL_GPL(ping_get_port); 149 150 int ping_hash(struct sock *sk) 151 { 152 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num); 153 BUG(); /* "Please do not press this button again." */ 154 155 return 0; 156 } 157 158 void ping_unhash(struct sock *sk) 159 { 160 struct inet_sock *isk = inet_sk(sk); 161 162 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); 163 spin_lock(&ping_table.lock); 164 if (sk_hashed(sk)) { 165 hlist_nulls_del_init_rcu(&sk->sk_nulls_node); 166 sock_put(sk); 167 isk->inet_num = 0; 168 isk->inet_sport = 0; 169 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 170 } 171 spin_unlock(&ping_table.lock); 172 } 173 EXPORT_SYMBOL_GPL(ping_unhash); 174 175 /* Called under rcu_read_lock() */ 176 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) 177 { 178 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); 179 struct sock *sk = NULL; 180 struct inet_sock *isk; 181 struct hlist_nulls_node *hnode; 182 int dif, sdif; 183 184 if (skb->protocol == htons(ETH_P_IP)) { 185 dif = inet_iif(skb); 186 sdif = inet_sdif(skb); 187 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n", 188 (int)ident, &ip_hdr(skb)->daddr, dif); 189 #if IS_ENABLED(CONFIG_IPV6) 190 } else if (skb->protocol == htons(ETH_P_IPV6)) { 191 dif = inet6_iif(skb); 192 sdif = inet6_sdif(skb); 193 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", 194 (int)ident, &ipv6_hdr(skb)->daddr, dif); 195 #endif 196 } else { 197 return NULL; 198 } 199 200 ping_portaddr_for_each_entry_rcu(sk, hnode, hslot) { 201 isk = inet_sk(sk); 202 203 pr_debug("iterate\n"); 204 if (isk->inet_num != ident) 205 continue; 206 207 if (skb->protocol == htons(ETH_P_IP) && 208 sk->sk_family == AF_INET) { 209 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, 210 (int) isk->inet_num, &isk->inet_rcv_saddr, 211 sk->sk_bound_dev_if); 212 213 if (isk->inet_rcv_saddr && 214 isk->inet_rcv_saddr != ip_hdr(skb)->daddr) 215 continue; 216 #if IS_ENABLED(CONFIG_IPV6) 217 } else if (skb->protocol == htons(ETH_P_IPV6) && 218 sk->sk_family == AF_INET6) { 219 220 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, 221 (int) isk->inet_num, 222 &sk->sk_v6_rcv_saddr, 223 sk->sk_bound_dev_if); 224 225 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 226 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, 227 &ipv6_hdr(skb)->daddr)) 228 continue; 229 #endif 230 } else { 231 continue; 232 } 233 234 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif && 235 sk->sk_bound_dev_if != sdif) 236 continue; 237 238 goto exit; 239 } 240 241 sk = NULL; 242 exit: 243 244 return sk; 245 } 246 247 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 248 kgid_t *high) 249 { 250 kgid_t *data = net->ipv4.ping_group_range.range; 251 unsigned int seq; 252 253 do { 254 seq = read_seqbegin(&net->ipv4.ping_group_range.lock); 255 256 *low = data[0]; 257 *high = data[1]; 258 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); 259 } 260 261 262 int ping_init_sock(struct sock *sk) 263 { 264 struct net *net = sock_net(sk); 265 kgid_t group = current_egid(); 266 struct group_info *group_info; 267 int i; 268 kgid_t low, high; 269 int ret = 0; 270 271 if (sk->sk_family == AF_INET6) 272 sk->sk_ipv6only = 1; 273 274 inet_get_ping_group_range_net(net, &low, &high); 275 if (gid_lte(low, group) && gid_lte(group, high)) 276 return 0; 277 278 group_info = get_current_groups(); 279 for (i = 0; i < group_info->ngroups; i++) { 280 kgid_t gid = group_info->gid[i]; 281 282 if (gid_lte(low, gid) && gid_lte(gid, high)) 283 goto out_release_group; 284 } 285 286 ret = -EACCES; 287 288 out_release_group: 289 put_group_info(group_info); 290 return ret; 291 } 292 EXPORT_SYMBOL_GPL(ping_init_sock); 293 294 void ping_close(struct sock *sk, long timeout) 295 { 296 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 297 inet_sk(sk), inet_sk(sk)->inet_num); 298 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt)); 299 300 sk_common_release(sk); 301 } 302 EXPORT_SYMBOL_GPL(ping_close); 303 304 static int ping_pre_connect(struct sock *sk, struct sockaddr *uaddr, 305 int addr_len) 306 { 307 /* This check is replicated from __ip4_datagram_connect() and 308 * intended to prevent BPF program called below from accessing bytes 309 * that are out of the bound specified by user in addr_len. 310 */ 311 if (addr_len < sizeof(struct sockaddr_in)) 312 return -EINVAL; 313 314 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr); 315 } 316 317 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 318 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 319 struct sockaddr *uaddr, int addr_len) 320 { 321 struct net *net = sock_net(sk); 322 if (sk->sk_family == AF_INET) { 323 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 324 u32 tb_id = RT_TABLE_LOCAL; 325 int chk_addr_ret; 326 327 if (addr_len < sizeof(*addr)) 328 return -EINVAL; 329 330 if (addr->sin_family != AF_INET && 331 !(addr->sin_family == AF_UNSPEC && 332 addr->sin_addr.s_addr == htonl(INADDR_ANY))) 333 return -EAFNOSUPPORT; 334 335 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 336 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 337 338 if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) 339 return 0; 340 341 tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id; 342 chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id); 343 344 if (chk_addr_ret == RTN_MULTICAST || 345 chk_addr_ret == RTN_BROADCAST || 346 (chk_addr_ret != RTN_LOCAL && 347 !inet_can_nonlocal_bind(net, isk))) 348 return -EADDRNOTAVAIL; 349 350 #if IS_ENABLED(CONFIG_IPV6) 351 } else if (sk->sk_family == AF_INET6) { 352 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 353 int addr_type, scoped, has_addr; 354 struct net_device *dev = NULL; 355 356 if (addr_len < sizeof(*addr)) 357 return -EINVAL; 358 359 if (addr->sin6_family != AF_INET6) 360 return -EAFNOSUPPORT; 361 362 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 363 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 364 365 addr_type = ipv6_addr_type(&addr->sin6_addr); 366 scoped = __ipv6_addr_needs_scope_id(addr_type); 367 if ((addr_type != IPV6_ADDR_ANY && 368 !(addr_type & IPV6_ADDR_UNICAST)) || 369 (scoped && !addr->sin6_scope_id)) 370 return -EINVAL; 371 372 rcu_read_lock(); 373 if (addr->sin6_scope_id) { 374 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 375 if (!dev) { 376 rcu_read_unlock(); 377 return -ENODEV; 378 } 379 } 380 381 if (!dev && sk->sk_bound_dev_if) { 382 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if); 383 if (!dev) { 384 rcu_read_unlock(); 385 return -ENODEV; 386 } 387 } 388 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 389 scoped); 390 rcu_read_unlock(); 391 392 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr || 393 addr_type == IPV6_ADDR_ANY)) 394 return -EADDRNOTAVAIL; 395 396 if (scoped) 397 sk->sk_bound_dev_if = addr->sin6_scope_id; 398 #endif 399 } else { 400 return -EAFNOSUPPORT; 401 } 402 return 0; 403 } 404 405 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 406 { 407 if (saddr->sa_family == AF_INET) { 408 struct inet_sock *isk = inet_sk(sk); 409 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 410 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 411 #if IS_ENABLED(CONFIG_IPV6) 412 } else if (saddr->sa_family == AF_INET6) { 413 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 414 struct ipv6_pinfo *np = inet6_sk(sk); 415 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 416 #endif 417 } 418 } 419 420 /* 421 * We need our own bind because there are no privileged id's == local ports. 422 * Moreover, we don't allow binding to multi- and broadcast addresses. 423 */ 424 425 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 426 { 427 struct inet_sock *isk = inet_sk(sk); 428 unsigned short snum; 429 int err; 430 int dif = sk->sk_bound_dev_if; 431 432 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 433 if (err) 434 return err; 435 436 lock_sock(sk); 437 438 err = -EINVAL; 439 if (isk->inet_num != 0) 440 goto out; 441 442 err = -EADDRINUSE; 443 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 444 if (ping_get_port(sk, snum) != 0) { 445 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */ 446 sk->sk_bound_dev_if = dif; 447 goto out; 448 } 449 ping_set_saddr(sk, uaddr); 450 451 pr_debug("after bind(): num = %hu, dif = %d\n", 452 isk->inet_num, 453 sk->sk_bound_dev_if); 454 455 err = 0; 456 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 457 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 458 #if IS_ENABLED(CONFIG_IPV6) 459 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 460 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 461 #endif 462 463 if (snum) 464 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 465 isk->inet_sport = htons(isk->inet_num); 466 isk->inet_daddr = 0; 467 isk->inet_dport = 0; 468 469 #if IS_ENABLED(CONFIG_IPV6) 470 if (sk->sk_family == AF_INET6) 471 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 472 #endif 473 474 sk_dst_reset(sk); 475 out: 476 release_sock(sk); 477 pr_debug("ping_v4_bind -> %d\n", err); 478 return err; 479 } 480 EXPORT_SYMBOL_GPL(ping_bind); 481 482 /* 483 * Is this a supported type of ICMP message? 484 */ 485 486 static inline int ping_supported(int family, int type, int code) 487 { 488 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 489 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) || 490 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) || 491 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0); 492 } 493 494 /* 495 * This routine is called by the ICMP module when it gets some 496 * sort of error condition. 497 */ 498 499 void ping_err(struct sk_buff *skb, int offset, u32 info) 500 { 501 int family; 502 struct icmphdr *icmph; 503 struct inet_sock *inet_sock; 504 int type; 505 int code; 506 struct net *net = dev_net(skb->dev); 507 struct sock *sk; 508 int harderr; 509 int err; 510 511 if (skb->protocol == htons(ETH_P_IP)) { 512 family = AF_INET; 513 type = icmp_hdr(skb)->type; 514 code = icmp_hdr(skb)->code; 515 icmph = (struct icmphdr *)(skb->data + offset); 516 } else if (skb->protocol == htons(ETH_P_IPV6)) { 517 family = AF_INET6; 518 type = icmp6_hdr(skb)->icmp6_type; 519 code = icmp6_hdr(skb)->icmp6_code; 520 icmph = (struct icmphdr *) (skb->data + offset); 521 } else { 522 BUG(); 523 } 524 525 /* We assume the packet has already been checked by icmp_unreach */ 526 527 if (!ping_supported(family, icmph->type, icmph->code)) 528 return; 529 530 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 531 skb->protocol, type, code, ntohs(icmph->un.echo.id), 532 ntohs(icmph->un.echo.sequence)); 533 534 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 535 if (!sk) { 536 pr_debug("no socket, dropping\n"); 537 return; /* No socket for error */ 538 } 539 pr_debug("err on socket %p\n", sk); 540 541 err = 0; 542 harderr = 0; 543 inet_sock = inet_sk(sk); 544 545 if (skb->protocol == htons(ETH_P_IP)) { 546 switch (type) { 547 default: 548 case ICMP_TIME_EXCEEDED: 549 err = EHOSTUNREACH; 550 break; 551 case ICMP_SOURCE_QUENCH: 552 /* This is not a real error but ping wants to see it. 553 * Report it with some fake errno. 554 */ 555 err = EREMOTEIO; 556 break; 557 case ICMP_PARAMETERPROB: 558 err = EPROTO; 559 harderr = 1; 560 break; 561 case ICMP_DEST_UNREACH: 562 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 563 ipv4_sk_update_pmtu(skb, sk, info); 564 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 565 err = EMSGSIZE; 566 harderr = 1; 567 break; 568 } 569 goto out; 570 } 571 err = EHOSTUNREACH; 572 if (code <= NR_ICMP_UNREACH) { 573 harderr = icmp_err_convert[code].fatal; 574 err = icmp_err_convert[code].errno; 575 } 576 break; 577 case ICMP_REDIRECT: 578 /* See ICMP_SOURCE_QUENCH */ 579 ipv4_sk_redirect(skb, sk); 580 err = EREMOTEIO; 581 break; 582 } 583 #if IS_ENABLED(CONFIG_IPV6) 584 } else if (skb->protocol == htons(ETH_P_IPV6)) { 585 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 586 #endif 587 } 588 589 /* 590 * RFC1122: OK. Passes ICMP errors back to application, as per 591 * 4.1.3.3. 592 */ 593 if ((family == AF_INET && !inet_sock->recverr) || 594 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 595 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 596 goto out; 597 } else { 598 if (family == AF_INET) { 599 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 600 info, (u8 *)icmph); 601 #if IS_ENABLED(CONFIG_IPV6) 602 } else if (family == AF_INET6) { 603 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 604 info, (u8 *)icmph); 605 #endif 606 } 607 } 608 sk->sk_err = err; 609 sk_error_report(sk); 610 out: 611 return; 612 } 613 EXPORT_SYMBOL_GPL(ping_err); 614 615 /* 616 * Copy and checksum an ICMP Echo packet from user space into a buffer 617 * starting from the payload. 618 */ 619 620 int ping_getfrag(void *from, char *to, 621 int offset, int fraglen, int odd, struct sk_buff *skb) 622 { 623 struct pingfakehdr *pfh = from; 624 625 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, 626 &pfh->msg->msg_iter)) 627 return -EFAULT; 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 = csum_block_add(skb->csum, pfh->wcheck, odd); 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 if (!skb) 651 return 0; 652 pfh->wcheck = csum_partial((char *)&pfh->icmph, 653 sizeof(struct icmphdr), pfh->wcheck); 654 pfh->icmph.checksum = csum_fold(pfh->wcheck); 655 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 656 skb->ip_summed = CHECKSUM_NONE; 657 return ip_push_pending_frames(sk, fl4); 658 } 659 660 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 661 void *user_icmph, size_t icmph_len) 662 { 663 u8 type, code; 664 665 if (len > 0xFFFF) 666 return -EMSGSIZE; 667 668 /* Must have at least a full ICMP header. */ 669 if (len < icmph_len) 670 return -EINVAL; 671 672 /* 673 * Check the flags. 674 */ 675 676 /* Mirror BSD error message compatibility */ 677 if (msg->msg_flags & MSG_OOB) 678 return -EOPNOTSUPP; 679 680 /* 681 * Fetch the ICMP header provided by the userland. 682 * iovec is modified! The ICMP header is consumed. 683 */ 684 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 685 return -EFAULT; 686 687 if (family == AF_INET) { 688 type = ((struct icmphdr *) user_icmph)->type; 689 code = ((struct icmphdr *) user_icmph)->code; 690 #if IS_ENABLED(CONFIG_IPV6) 691 } else if (family == AF_INET6) { 692 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 693 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 694 #endif 695 } else { 696 BUG(); 697 } 698 699 if (!ping_supported(family, type, code)) 700 return -EINVAL; 701 702 return 0; 703 } 704 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 705 706 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 707 { 708 struct net *net = sock_net(sk); 709 struct flowi4 fl4; 710 struct inet_sock *inet = inet_sk(sk); 711 struct ipcm_cookie ipc; 712 struct icmphdr user_icmph; 713 struct pingfakehdr pfh; 714 struct rtable *rt = NULL; 715 struct ip_options_data opt_copy; 716 int free = 0; 717 __be32 saddr, daddr, faddr; 718 u8 tos; 719 int err; 720 721 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 722 723 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 724 sizeof(user_icmph)); 725 if (err) 726 return err; 727 728 /* 729 * Get and verify the address. 730 */ 731 732 if (msg->msg_name) { 733 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 734 if (msg->msg_namelen < sizeof(*usin)) 735 return -EINVAL; 736 if (usin->sin_family != AF_INET) 737 return -EAFNOSUPPORT; 738 daddr = usin->sin_addr.s_addr; 739 /* no remote port */ 740 } else { 741 if (sk->sk_state != TCP_ESTABLISHED) 742 return -EDESTADDRREQ; 743 daddr = inet->inet_daddr; 744 /* no remote port */ 745 } 746 747 ipcm_init_sk(&ipc, inet); 748 749 if (msg->msg_controllen) { 750 err = ip_cmsg_send(sk, msg, &ipc, false); 751 if (unlikely(err)) { 752 kfree(ipc.opt); 753 return err; 754 } 755 if (ipc.opt) 756 free = 1; 757 } 758 if (!ipc.opt) { 759 struct ip_options_rcu *inet_opt; 760 761 rcu_read_lock(); 762 inet_opt = rcu_dereference(inet->inet_opt); 763 if (inet_opt) { 764 memcpy(&opt_copy, inet_opt, 765 sizeof(*inet_opt) + inet_opt->opt.optlen); 766 ipc.opt = &opt_copy.opt; 767 } 768 rcu_read_unlock(); 769 } 770 771 saddr = ipc.addr; 772 ipc.addr = faddr = daddr; 773 774 if (ipc.opt && ipc.opt->opt.srr) { 775 if (!daddr) { 776 err = -EINVAL; 777 goto out_free; 778 } 779 faddr = ipc.opt->opt.faddr; 780 } 781 tos = get_rttos(&ipc, inet); 782 if (sock_flag(sk, SOCK_LOCALROUTE) || 783 (msg->msg_flags & MSG_DONTROUTE) || 784 (ipc.opt && ipc.opt->opt.is_strictroute)) { 785 tos |= RTO_ONLINK; 786 } 787 788 if (ipv4_is_multicast(daddr)) { 789 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 790 ipc.oif = inet->mc_index; 791 if (!saddr) 792 saddr = inet->mc_addr; 793 } else if (!ipc.oif) 794 ipc.oif = inet->uc_index; 795 796 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, 797 RT_SCOPE_UNIVERSE, sk->sk_protocol, 798 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 799 sk->sk_uid); 800 801 fl4.fl4_icmp_type = user_icmph.type; 802 fl4.fl4_icmp_code = user_icmph.code; 803 804 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4)); 805 rt = ip_route_output_flow(net, &fl4, sk); 806 if (IS_ERR(rt)) { 807 err = PTR_ERR(rt); 808 rt = NULL; 809 if (err == -ENETUNREACH) 810 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 811 goto out; 812 } 813 814 err = -EACCES; 815 if ((rt->rt_flags & RTCF_BROADCAST) && 816 !sock_flag(sk, SOCK_BROADCAST)) 817 goto out; 818 819 if (msg->msg_flags & MSG_CONFIRM) 820 goto do_confirm; 821 back_from_confirm: 822 823 if (!ipc.addr) 824 ipc.addr = fl4.daddr; 825 826 lock_sock(sk); 827 828 pfh.icmph.type = user_icmph.type; /* already checked */ 829 pfh.icmph.code = user_icmph.code; /* ditto */ 830 pfh.icmph.checksum = 0; 831 pfh.icmph.un.echo.id = inet->inet_sport; 832 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 833 pfh.msg = msg; 834 pfh.wcheck = 0; 835 pfh.family = AF_INET; 836 837 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 838 sizeof(struct icmphdr), &ipc, &rt, 839 msg->msg_flags); 840 if (err) 841 ip_flush_pending_frames(sk); 842 else 843 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 844 release_sock(sk); 845 846 out: 847 ip_rt_put(rt); 848 out_free: 849 if (free) 850 kfree(ipc.opt); 851 if (!err) { 852 icmp_out_count(sock_net(sk), user_icmph.type); 853 return len; 854 } 855 return err; 856 857 do_confirm: 858 if (msg->msg_flags & MSG_PROBE) 859 dst_confirm_neigh(&rt->dst, &fl4.daddr); 860 if (!(msg->msg_flags & MSG_PROBE) || len) 861 goto back_from_confirm; 862 err = 0; 863 goto out; 864 } 865 866 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags, 867 int *addr_len) 868 { 869 struct inet_sock *isk = inet_sk(sk); 870 int family = sk->sk_family; 871 struct sk_buff *skb; 872 int copied, err; 873 874 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 875 876 err = -EOPNOTSUPP; 877 if (flags & MSG_OOB) 878 goto out; 879 880 if (flags & MSG_ERRQUEUE) 881 return inet_recv_error(sk, msg, len, addr_len); 882 883 skb = skb_recv_datagram(sk, flags, &err); 884 if (!skb) 885 goto out; 886 887 copied = skb->len; 888 if (copied > len) { 889 msg->msg_flags |= MSG_TRUNC; 890 copied = len; 891 } 892 893 /* Don't bother checking the checksum */ 894 err = skb_copy_datagram_msg(skb, 0, msg, copied); 895 if (err) 896 goto done; 897 898 sock_recv_timestamp(msg, sk, skb); 899 900 /* Copy the address and add cmsg data. */ 901 if (family == AF_INET) { 902 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 903 904 if (sin) { 905 sin->sin_family = AF_INET; 906 sin->sin_port = 0 /* skb->h.uh->source */; 907 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 908 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 909 *addr_len = sizeof(*sin); 910 } 911 912 if (isk->cmsg_flags) 913 ip_cmsg_recv(msg, skb); 914 915 #if IS_ENABLED(CONFIG_IPV6) 916 } else if (family == AF_INET6) { 917 struct ipv6_pinfo *np = inet6_sk(sk); 918 struct ipv6hdr *ip6 = ipv6_hdr(skb); 919 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 920 921 if (sin6) { 922 sin6->sin6_family = AF_INET6; 923 sin6->sin6_port = 0; 924 sin6->sin6_addr = ip6->saddr; 925 sin6->sin6_flowinfo = 0; 926 if (np->sndflow) 927 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 928 sin6->sin6_scope_id = 929 ipv6_iface_scope_id(&sin6->sin6_addr, 930 inet6_iif(skb)); 931 *addr_len = sizeof(*sin6); 932 } 933 934 if (inet6_sk(sk)->rxopt.all) 935 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 936 if (skb->protocol == htons(ETH_P_IPV6) && 937 inet6_sk(sk)->rxopt.all) 938 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 939 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 940 ip_cmsg_recv(msg, skb); 941 #endif 942 } else { 943 BUG(); 944 } 945 946 err = copied; 947 948 done: 949 skb_free_datagram(sk, skb); 950 out: 951 pr_debug("ping_recvmsg -> %d\n", err); 952 return err; 953 } 954 EXPORT_SYMBOL_GPL(ping_recvmsg); 955 956 static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk, 957 struct sk_buff *skb) 958 { 959 enum skb_drop_reason reason; 960 961 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 962 inet_sk(sk), inet_sk(sk)->inet_num, skb); 963 if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) { 964 kfree_skb_reason(skb, reason); 965 pr_debug("ping_queue_rcv_skb -> failed\n"); 966 return reason; 967 } 968 return SKB_NOT_DROPPED_YET; 969 } 970 971 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 972 { 973 return __ping_queue_rcv_skb(sk, skb) ? -1 : 0; 974 } 975 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 976 977 978 /* 979 * All we need to do is get the socket. 980 */ 981 982 enum skb_drop_reason ping_rcv(struct sk_buff *skb) 983 { 984 enum skb_drop_reason reason = SKB_DROP_REASON_NO_SOCKET; 985 struct sock *sk; 986 struct net *net = dev_net(skb->dev); 987 struct icmphdr *icmph = icmp_hdr(skb); 988 989 /* We assume the packet has already been checked by icmp_rcv */ 990 991 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 992 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 993 994 /* Push ICMP header back */ 995 skb_push(skb, skb->data - (u8 *)icmph); 996 997 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 998 if (sk) { 999 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 1000 1001 pr_debug("rcv on socket %p\n", sk); 1002 if (skb2) 1003 reason = __ping_queue_rcv_skb(sk, skb2); 1004 else 1005 reason = SKB_DROP_REASON_NOMEM; 1006 } 1007 1008 if (reason) 1009 pr_debug("no socket, dropping\n"); 1010 1011 return reason; 1012 } 1013 EXPORT_SYMBOL_GPL(ping_rcv); 1014 1015 struct proto ping_prot = { 1016 .name = "PING", 1017 .owner = THIS_MODULE, 1018 .init = ping_init_sock, 1019 .close = ping_close, 1020 .pre_connect = ping_pre_connect, 1021 .connect = ip4_datagram_connect, 1022 .disconnect = __udp_disconnect, 1023 .setsockopt = ip_setsockopt, 1024 .getsockopt = ip_getsockopt, 1025 .sendmsg = ping_v4_sendmsg, 1026 .recvmsg = ping_recvmsg, 1027 .bind = ping_bind, 1028 .backlog_rcv = ping_queue_rcv_skb, 1029 .release_cb = ip4_datagram_release_cb, 1030 .hash = ping_hash, 1031 .unhash = ping_unhash, 1032 .get_port = ping_get_port, 1033 .put_port = ping_unhash, 1034 .obj_size = sizeof(struct inet_sock), 1035 }; 1036 EXPORT_SYMBOL(ping_prot); 1037 1038 #ifdef CONFIG_PROC_FS 1039 1040 static struct sock *ping_get_first(struct seq_file *seq, int start) 1041 { 1042 struct sock *sk; 1043 struct ping_iter_state *state = seq->private; 1044 struct net *net = seq_file_net(seq); 1045 1046 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1047 ++state->bucket) { 1048 struct hlist_nulls_node *node; 1049 struct hlist_nulls_head *hslot; 1050 1051 hslot = &ping_table.hash[state->bucket]; 1052 1053 if (hlist_nulls_empty(hslot)) 1054 continue; 1055 1056 sk_nulls_for_each(sk, node, hslot) { 1057 if (net_eq(sock_net(sk), net) && 1058 sk->sk_family == state->family) 1059 goto found; 1060 } 1061 } 1062 sk = NULL; 1063 found: 1064 return sk; 1065 } 1066 1067 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1068 { 1069 struct ping_iter_state *state = seq->private; 1070 struct net *net = seq_file_net(seq); 1071 1072 do { 1073 sk = sk_nulls_next(sk); 1074 } while (sk && (!net_eq(sock_net(sk), net))); 1075 1076 if (!sk) 1077 return ping_get_first(seq, state->bucket + 1); 1078 return sk; 1079 } 1080 1081 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1082 { 1083 struct sock *sk = ping_get_first(seq, 0); 1084 1085 if (sk) 1086 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1087 --pos; 1088 return pos ? NULL : sk; 1089 } 1090 1091 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1092 __acquires(ping_table.lock) 1093 { 1094 struct ping_iter_state *state = seq->private; 1095 state->bucket = 0; 1096 state->family = family; 1097 1098 spin_lock(&ping_table.lock); 1099 1100 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1101 } 1102 EXPORT_SYMBOL_GPL(ping_seq_start); 1103 1104 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1105 { 1106 return ping_seq_start(seq, pos, AF_INET); 1107 } 1108 1109 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1110 { 1111 struct sock *sk; 1112 1113 if (v == SEQ_START_TOKEN) 1114 sk = ping_get_idx(seq, 0); 1115 else 1116 sk = ping_get_next(seq, v); 1117 1118 ++*pos; 1119 return sk; 1120 } 1121 EXPORT_SYMBOL_GPL(ping_seq_next); 1122 1123 void ping_seq_stop(struct seq_file *seq, void *v) 1124 __releases(ping_table.lock) 1125 { 1126 spin_unlock(&ping_table.lock); 1127 } 1128 EXPORT_SYMBOL_GPL(ping_seq_stop); 1129 1130 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1131 int bucket) 1132 { 1133 struct inet_sock *inet = inet_sk(sp); 1134 __be32 dest = inet->inet_daddr; 1135 __be32 src = inet->inet_rcv_saddr; 1136 __u16 destp = ntohs(inet->inet_dport); 1137 __u16 srcp = ntohs(inet->inet_sport); 1138 1139 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1140 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", 1141 bucket, src, srcp, dest, destp, sp->sk_state, 1142 sk_wmem_alloc_get(sp), 1143 sk_rmem_alloc_get(sp), 1144 0, 0L, 0, 1145 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1146 0, sock_i_ino(sp), 1147 refcount_read(&sp->sk_refcnt), sp, 1148 atomic_read(&sp->sk_drops)); 1149 } 1150 1151 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1152 { 1153 seq_setwidth(seq, 127); 1154 if (v == SEQ_START_TOKEN) 1155 seq_puts(seq, " sl local_address rem_address st tx_queue " 1156 "rx_queue tr tm->when retrnsmt uid timeout " 1157 "inode ref pointer drops"); 1158 else { 1159 struct ping_iter_state *state = seq->private; 1160 1161 ping_v4_format_sock(v, seq, state->bucket); 1162 } 1163 seq_pad(seq, '\n'); 1164 return 0; 1165 } 1166 1167 static const struct seq_operations ping_v4_seq_ops = { 1168 .start = ping_v4_seq_start, 1169 .show = ping_v4_seq_show, 1170 .next = ping_seq_next, 1171 .stop = ping_seq_stop, 1172 }; 1173 1174 static int __net_init ping_v4_proc_init_net(struct net *net) 1175 { 1176 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops, 1177 sizeof(struct ping_iter_state))) 1178 return -ENOMEM; 1179 return 0; 1180 } 1181 1182 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1183 { 1184 remove_proc_entry("icmp", net->proc_net); 1185 } 1186 1187 static struct pernet_operations ping_v4_net_ops = { 1188 .init = ping_v4_proc_init_net, 1189 .exit = ping_v4_proc_exit_net, 1190 }; 1191 1192 int __init ping_proc_init(void) 1193 { 1194 return register_pernet_subsys(&ping_v4_net_ops); 1195 } 1196 1197 void ping_proc_exit(void) 1198 { 1199 unregister_pernet_subsys(&ping_v4_net_ops); 1200 } 1201 1202 #endif 1203 1204 void __init ping_init(void) 1205 { 1206 int i; 1207 1208 for (i = 0; i < PING_HTABLE_SIZE; i++) 1209 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1210 spin_lock_init(&ping_table.lock); 1211 } 1212