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 <net/sock.h> 37 #include <net/ping.h> 38 #include <net/udp.h> 39 #include <net/route.h> 40 #include <net/inet_common.h> 41 #include <net/checksum.h> 42 43 #if IS_ENABLED(CONFIG_IPV6) 44 #include <linux/in6.h> 45 #include <linux/icmpv6.h> 46 #include <net/addrconf.h> 47 #include <net/ipv6.h> 48 #include <net/transp_v6.h> 49 #endif 50 51 struct ping_table { 52 struct hlist_nulls_head hash[PING_HTABLE_SIZE]; 53 rwlock_t lock; 54 }; 55 56 static struct ping_table ping_table; 57 struct pingv6_ops pingv6_ops; 58 EXPORT_SYMBOL_GPL(pingv6_ops); 59 60 static u16 ping_port_rover; 61 62 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask) 63 { 64 u32 res = (num + net_hash_mix(net)) & mask; 65 66 pr_debug("hash(%u) = %u\n", num, res); 67 return res; 68 } 69 EXPORT_SYMBOL_GPL(ping_hash); 70 71 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table, 72 struct net *net, unsigned int num) 73 { 74 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)]; 75 } 76 77 int ping_get_port(struct sock *sk, unsigned short ident) 78 { 79 struct hlist_nulls_node *node; 80 struct hlist_nulls_head *hlist; 81 struct inet_sock *isk, *isk2; 82 struct sock *sk2 = NULL; 83 84 isk = inet_sk(sk); 85 write_lock_bh(&ping_table.lock); 86 if (ident == 0) { 87 u32 i; 88 u16 result = ping_port_rover + 1; 89 90 for (i = 0; i < (1L << 16); i++, result++) { 91 if (!result) 92 result++; /* avoid zero */ 93 hlist = ping_hashslot(&ping_table, sock_net(sk), 94 result); 95 ping_portaddr_for_each_entry(sk2, node, hlist) { 96 isk2 = inet_sk(sk2); 97 98 if (isk2->inet_num == result) 99 goto next_port; 100 } 101 102 /* found */ 103 ping_port_rover = ident = result; 104 break; 105 next_port: 106 ; 107 } 108 if (i >= (1L << 16)) 109 goto fail; 110 } else { 111 hlist = ping_hashslot(&ping_table, sock_net(sk), ident); 112 ping_portaddr_for_each_entry(sk2, node, hlist) { 113 isk2 = inet_sk(sk2); 114 115 /* BUG? Why is this reuse and not reuseaddr? ping.c 116 * doesn't turn off SO_REUSEADDR, and it doesn't expect 117 * that other ping processes can steal its packets. 118 */ 119 if ((isk2->inet_num == ident) && 120 (sk2 != sk) && 121 (!sk2->sk_reuse || !sk->sk_reuse)) 122 goto fail; 123 } 124 } 125 126 pr_debug("found port/ident = %d\n", ident); 127 isk->inet_num = ident; 128 if (sk_unhashed(sk)) { 129 pr_debug("was not hashed\n"); 130 sock_hold(sk); 131 hlist_nulls_add_head(&sk->sk_nulls_node, hlist); 132 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 133 } 134 write_unlock_bh(&ping_table.lock); 135 return 0; 136 137 fail: 138 write_unlock_bh(&ping_table.lock); 139 return 1; 140 } 141 EXPORT_SYMBOL_GPL(ping_get_port); 142 143 int ping_hash(struct sock *sk) 144 { 145 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num); 146 BUG(); /* "Please do not press this button again." */ 147 148 return 0; 149 } 150 151 void ping_unhash(struct sock *sk) 152 { 153 struct inet_sock *isk = inet_sk(sk); 154 155 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); 156 write_lock_bh(&ping_table.lock); 157 if (sk_hashed(sk)) { 158 hlist_nulls_del(&sk->sk_nulls_node); 159 sk_nulls_node_init(&sk->sk_nulls_node); 160 sock_put(sk); 161 isk->inet_num = 0; 162 isk->inet_sport = 0; 163 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 164 } 165 write_unlock_bh(&ping_table.lock); 166 } 167 EXPORT_SYMBOL_GPL(ping_unhash); 168 169 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) 170 { 171 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); 172 struct sock *sk = NULL; 173 struct inet_sock *isk; 174 struct hlist_nulls_node *hnode; 175 int dif, sdif; 176 177 if (skb->protocol == htons(ETH_P_IP)) { 178 dif = inet_iif(skb); 179 sdif = inet_sdif(skb); 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 dif = inet6_iif(skb); 185 sdif = inet6_sdif(skb); 186 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", 187 (int)ident, &ipv6_hdr(skb)->daddr, dif); 188 #endif 189 } else { 190 return NULL; 191 } 192 193 read_lock_bh(&ping_table.lock); 194 195 ping_portaddr_for_each_entry(sk, hnode, hslot) { 196 isk = inet_sk(sk); 197 198 pr_debug("iterate\n"); 199 if (isk->inet_num != ident) 200 continue; 201 202 if (skb->protocol == htons(ETH_P_IP) && 203 sk->sk_family == AF_INET) { 204 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, 205 (int) isk->inet_num, &isk->inet_rcv_saddr, 206 sk->sk_bound_dev_if); 207 208 if (isk->inet_rcv_saddr && 209 isk->inet_rcv_saddr != ip_hdr(skb)->daddr) 210 continue; 211 #if IS_ENABLED(CONFIG_IPV6) 212 } else if (skb->protocol == htons(ETH_P_IPV6) && 213 sk->sk_family == AF_INET6) { 214 215 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, 216 (int) isk->inet_num, 217 &sk->sk_v6_rcv_saddr, 218 sk->sk_bound_dev_if); 219 220 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 221 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, 222 &ipv6_hdr(skb)->daddr)) 223 continue; 224 #endif 225 } else { 226 continue; 227 } 228 229 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif && 230 sk->sk_bound_dev_if != sdif) 231 continue; 232 233 sock_hold(sk); 234 goto exit; 235 } 236 237 sk = NULL; 238 exit: 239 read_unlock_bh(&ping_table.lock); 240 241 return sk; 242 } 243 244 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 245 kgid_t *high) 246 { 247 kgid_t *data = net->ipv4.ping_group_range.range; 248 unsigned int seq; 249 250 do { 251 seq = read_seqbegin(&net->ipv4.ping_group_range.lock); 252 253 *low = data[0]; 254 *high = data[1]; 255 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); 256 } 257 258 259 int ping_init_sock(struct sock *sk) 260 { 261 struct net *net = sock_net(sk); 262 kgid_t group = current_egid(); 263 struct group_info *group_info; 264 int i; 265 kgid_t low, high; 266 int ret = 0; 267 268 if (sk->sk_family == AF_INET6) 269 sk->sk_ipv6only = 1; 270 271 inet_get_ping_group_range_net(net, &low, &high); 272 if (gid_lte(low, group) && gid_lte(group, high)) 273 return 0; 274 275 group_info = get_current_groups(); 276 for (i = 0; i < group_info->ngroups; i++) { 277 kgid_t gid = group_info->gid[i]; 278 279 if (gid_lte(low, gid) && gid_lte(gid, high)) 280 goto out_release_group; 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", refcount_read(&sk->sk_refcnt)); 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 { 305 struct net *net = sock_net(sk); 306 if (sk->sk_family == AF_INET) { 307 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 308 u32 tb_id = RT_TABLE_LOCAL; 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 tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id; 323 chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id); 324 325 if (!inet_addr_valid_or_nonlocal(net, inet_sk(sk), 326 addr->sin_addr.s_addr, 327 chk_addr_ret)) 328 return -EADDRNOTAVAIL; 329 330 #if IS_ENABLED(CONFIG_IPV6) 331 } else if (sk->sk_family == AF_INET6) { 332 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 333 int addr_type, scoped, has_addr; 334 struct net_device *dev = NULL; 335 336 if (addr_len < sizeof(*addr)) 337 return -EINVAL; 338 339 if (addr->sin6_family != AF_INET6) 340 return -EAFNOSUPPORT; 341 342 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 343 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 344 345 addr_type = ipv6_addr_type(&addr->sin6_addr); 346 scoped = __ipv6_addr_needs_scope_id(addr_type); 347 if ((addr_type != IPV6_ADDR_ANY && 348 !(addr_type & IPV6_ADDR_UNICAST)) || 349 (scoped && !addr->sin6_scope_id)) 350 return -EINVAL; 351 352 rcu_read_lock(); 353 if (addr->sin6_scope_id) { 354 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 355 if (!dev) { 356 rcu_read_unlock(); 357 return -ENODEV; 358 } 359 } 360 361 if (!dev && sk->sk_bound_dev_if) { 362 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if); 363 if (!dev) { 364 rcu_read_unlock(); 365 return -ENODEV; 366 } 367 } 368 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 369 scoped); 370 rcu_read_unlock(); 371 372 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr || 373 addr_type == IPV6_ADDR_ANY)) 374 return -EADDRNOTAVAIL; 375 376 if (scoped) 377 sk->sk_bound_dev_if = addr->sin6_scope_id; 378 #endif 379 } else { 380 return -EAFNOSUPPORT; 381 } 382 return 0; 383 } 384 385 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 386 { 387 if (saddr->sa_family == AF_INET) { 388 struct inet_sock *isk = inet_sk(sk); 389 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 390 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 391 #if IS_ENABLED(CONFIG_IPV6) 392 } else if (saddr->sa_family == AF_INET6) { 393 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 394 struct ipv6_pinfo *np = inet6_sk(sk); 395 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 396 #endif 397 } 398 } 399 400 /* 401 * We need our own bind because there are no privileged id's == local ports. 402 * Moreover, we don't allow binding to multi- and broadcast addresses. 403 */ 404 405 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 406 { 407 struct inet_sock *isk = inet_sk(sk); 408 unsigned short snum; 409 int err; 410 int dif = sk->sk_bound_dev_if; 411 412 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 413 if (err) 414 return err; 415 416 lock_sock(sk); 417 418 err = -EINVAL; 419 if (isk->inet_num != 0) 420 goto out; 421 422 err = -EADDRINUSE; 423 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 424 if (ping_get_port(sk, snum) != 0) { 425 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */ 426 sk->sk_bound_dev_if = dif; 427 goto out; 428 } 429 ping_set_saddr(sk, uaddr); 430 431 pr_debug("after bind(): num = %hu, dif = %d\n", 432 isk->inet_num, 433 sk->sk_bound_dev_if); 434 435 err = 0; 436 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 437 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 438 #if IS_ENABLED(CONFIG_IPV6) 439 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 440 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 441 #endif 442 443 if (snum) 444 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 445 isk->inet_sport = htons(isk->inet_num); 446 isk->inet_daddr = 0; 447 isk->inet_dport = 0; 448 449 #if IS_ENABLED(CONFIG_IPV6) 450 if (sk->sk_family == AF_INET6) 451 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 452 #endif 453 454 sk_dst_reset(sk); 455 out: 456 release_sock(sk); 457 pr_debug("ping_v4_bind -> %d\n", err); 458 return err; 459 } 460 EXPORT_SYMBOL_GPL(ping_bind); 461 462 /* 463 * Is this a supported type of ICMP message? 464 */ 465 466 static inline int ping_supported(int family, int type, int code) 467 { 468 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 469 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) || 470 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) || 471 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0); 472 } 473 474 /* 475 * This routine is called by the ICMP module when it gets some 476 * sort of error condition. 477 */ 478 479 void ping_err(struct sk_buff *skb, int offset, u32 info) 480 { 481 int family; 482 struct icmphdr *icmph; 483 struct inet_sock *inet_sock; 484 int type; 485 int code; 486 struct net *net = dev_net(skb->dev); 487 struct sock *sk; 488 int harderr; 489 int err; 490 491 if (skb->protocol == htons(ETH_P_IP)) { 492 family = AF_INET; 493 type = icmp_hdr(skb)->type; 494 code = icmp_hdr(skb)->code; 495 icmph = (struct icmphdr *)(skb->data + offset); 496 } else if (skb->protocol == htons(ETH_P_IPV6)) { 497 family = AF_INET6; 498 type = icmp6_hdr(skb)->icmp6_type; 499 code = icmp6_hdr(skb)->icmp6_code; 500 icmph = (struct icmphdr *) (skb->data + offset); 501 } else { 502 BUG(); 503 } 504 505 /* We assume the packet has already been checked by icmp_unreach */ 506 507 if (!ping_supported(family, icmph->type, icmph->code)) 508 return; 509 510 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 511 skb->protocol, type, code, ntohs(icmph->un.echo.id), 512 ntohs(icmph->un.echo.sequence)); 513 514 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 515 if (!sk) { 516 pr_debug("no socket, dropping\n"); 517 return; /* No socket for error */ 518 } 519 pr_debug("err on socket %p\n", sk); 520 521 err = 0; 522 harderr = 0; 523 inet_sock = inet_sk(sk); 524 525 if (skb->protocol == htons(ETH_P_IP)) { 526 switch (type) { 527 default: 528 case ICMP_TIME_EXCEEDED: 529 err = EHOSTUNREACH; 530 break; 531 case ICMP_SOURCE_QUENCH: 532 /* This is not a real error but ping wants to see it. 533 * Report it with some fake errno. 534 */ 535 err = EREMOTEIO; 536 break; 537 case ICMP_PARAMETERPROB: 538 err = EPROTO; 539 harderr = 1; 540 break; 541 case ICMP_DEST_UNREACH: 542 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 543 ipv4_sk_update_pmtu(skb, sk, info); 544 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 545 err = EMSGSIZE; 546 harderr = 1; 547 break; 548 } 549 goto out; 550 } 551 err = EHOSTUNREACH; 552 if (code <= NR_ICMP_UNREACH) { 553 harderr = icmp_err_convert[code].fatal; 554 err = icmp_err_convert[code].errno; 555 } 556 break; 557 case ICMP_REDIRECT: 558 /* See ICMP_SOURCE_QUENCH */ 559 ipv4_sk_redirect(skb, sk); 560 err = EREMOTEIO; 561 break; 562 } 563 #if IS_ENABLED(CONFIG_IPV6) 564 } else if (skb->protocol == htons(ETH_P_IPV6)) { 565 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 566 #endif 567 } 568 569 /* 570 * RFC1122: OK. Passes ICMP errors back to application, as per 571 * 4.1.3.3. 572 */ 573 if ((family == AF_INET && !inet_sock->recverr) || 574 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 575 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 576 goto out; 577 } else { 578 if (family == AF_INET) { 579 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 580 info, (u8 *)icmph); 581 #if IS_ENABLED(CONFIG_IPV6) 582 } else if (family == AF_INET6) { 583 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 584 info, (u8 *)icmph); 585 #endif 586 } 587 } 588 sk->sk_err = err; 589 sk_error_report(sk); 590 out: 591 sock_put(sk); 592 } 593 EXPORT_SYMBOL_GPL(ping_err); 594 595 /* 596 * Copy and checksum an ICMP Echo packet from user space into a buffer 597 * starting from the payload. 598 */ 599 600 int ping_getfrag(void *from, char *to, 601 int offset, int fraglen, int odd, struct sk_buff *skb) 602 { 603 struct pingfakehdr *pfh = from; 604 605 if (offset == 0) { 606 fraglen -= sizeof(struct icmphdr); 607 if (fraglen < 0) 608 BUG(); 609 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), 610 fraglen, &pfh->wcheck, 611 &pfh->msg->msg_iter)) 612 return -EFAULT; 613 } else if (offset < sizeof(struct icmphdr)) { 614 BUG(); 615 } else { 616 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, 617 &pfh->msg->msg_iter)) 618 return -EFAULT; 619 } 620 621 #if IS_ENABLED(CONFIG_IPV6) 622 /* For IPv6, checksum each skb as we go along, as expected by 623 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 624 * wcheck, it will be finalized in ping_v4_push_pending_frames. 625 */ 626 if (pfh->family == AF_INET6) { 627 skb->csum = pfh->wcheck; 628 skb->ip_summed = CHECKSUM_NONE; 629 pfh->wcheck = 0; 630 } 631 #endif 632 633 return 0; 634 } 635 EXPORT_SYMBOL_GPL(ping_getfrag); 636 637 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 638 struct flowi4 *fl4) 639 { 640 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 641 642 if (!skb) 643 return 0; 644 pfh->wcheck = csum_partial((char *)&pfh->icmph, 645 sizeof(struct icmphdr), pfh->wcheck); 646 pfh->icmph.checksum = csum_fold(pfh->wcheck); 647 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 648 skb->ip_summed = CHECKSUM_NONE; 649 return ip_push_pending_frames(sk, fl4); 650 } 651 652 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 653 void *user_icmph, size_t icmph_len) 654 { 655 u8 type, code; 656 657 if (len > 0xFFFF) 658 return -EMSGSIZE; 659 660 /* Must have at least a full ICMP header. */ 661 if (len < icmph_len) 662 return -EINVAL; 663 664 /* 665 * Check the flags. 666 */ 667 668 /* Mirror BSD error message compatibility */ 669 if (msg->msg_flags & MSG_OOB) 670 return -EOPNOTSUPP; 671 672 /* 673 * Fetch the ICMP header provided by the userland. 674 * iovec is modified! The ICMP header is consumed. 675 */ 676 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 677 return -EFAULT; 678 679 if (family == AF_INET) { 680 type = ((struct icmphdr *) user_icmph)->type; 681 code = ((struct icmphdr *) user_icmph)->code; 682 #if IS_ENABLED(CONFIG_IPV6) 683 } else if (family == AF_INET6) { 684 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 685 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 686 #endif 687 } else { 688 BUG(); 689 } 690 691 if (!ping_supported(family, type, code)) 692 return -EINVAL; 693 694 return 0; 695 } 696 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 697 698 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 699 { 700 struct net *net = sock_net(sk); 701 struct flowi4 fl4; 702 struct inet_sock *inet = inet_sk(sk); 703 struct ipcm_cookie ipc; 704 struct icmphdr user_icmph; 705 struct pingfakehdr pfh; 706 struct rtable *rt = NULL; 707 struct ip_options_data opt_copy; 708 int free = 0; 709 __be32 saddr, daddr, faddr; 710 u8 tos; 711 int err; 712 713 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 714 715 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 716 sizeof(user_icmph)); 717 if (err) 718 return err; 719 720 /* 721 * Get and verify the address. 722 */ 723 724 if (msg->msg_name) { 725 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 726 if (msg->msg_namelen < sizeof(*usin)) 727 return -EINVAL; 728 if (usin->sin_family != AF_INET) 729 return -EAFNOSUPPORT; 730 daddr = usin->sin_addr.s_addr; 731 /* no remote port */ 732 } else { 733 if (sk->sk_state != TCP_ESTABLISHED) 734 return -EDESTADDRREQ; 735 daddr = inet->inet_daddr; 736 /* no remote port */ 737 } 738 739 ipcm_init_sk(&ipc, inet); 740 741 if (msg->msg_controllen) { 742 err = ip_cmsg_send(sk, msg, &ipc, false); 743 if (unlikely(err)) { 744 kfree(ipc.opt); 745 return err; 746 } 747 if (ipc.opt) 748 free = 1; 749 } 750 if (!ipc.opt) { 751 struct ip_options_rcu *inet_opt; 752 753 rcu_read_lock(); 754 inet_opt = rcu_dereference(inet->inet_opt); 755 if (inet_opt) { 756 memcpy(&opt_copy, inet_opt, 757 sizeof(*inet_opt) + inet_opt->opt.optlen); 758 ipc.opt = &opt_copy.opt; 759 } 760 rcu_read_unlock(); 761 } 762 763 saddr = ipc.addr; 764 ipc.addr = faddr = daddr; 765 766 if (ipc.opt && ipc.opt->opt.srr) { 767 if (!daddr) { 768 err = -EINVAL; 769 goto out_free; 770 } 771 faddr = ipc.opt->opt.faddr; 772 } 773 tos = get_rttos(&ipc, inet); 774 if (sock_flag(sk, SOCK_LOCALROUTE) || 775 (msg->msg_flags & MSG_DONTROUTE) || 776 (ipc.opt && ipc.opt->opt.is_strictroute)) { 777 tos |= RTO_ONLINK; 778 } 779 780 if (ipv4_is_multicast(daddr)) { 781 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 782 ipc.oif = inet->mc_index; 783 if (!saddr) 784 saddr = inet->mc_addr; 785 } else if (!ipc.oif) 786 ipc.oif = inet->uc_index; 787 788 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, 789 RT_SCOPE_UNIVERSE, sk->sk_protocol, 790 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 791 sk->sk_uid); 792 793 fl4.fl4_icmp_type = user_icmph.type; 794 fl4.fl4_icmp_code = user_icmph.code; 795 796 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4)); 797 rt = ip_route_output_flow(net, &fl4, sk); 798 if (IS_ERR(rt)) { 799 err = PTR_ERR(rt); 800 rt = NULL; 801 if (err == -ENETUNREACH) 802 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 803 goto out; 804 } 805 806 err = -EACCES; 807 if ((rt->rt_flags & RTCF_BROADCAST) && 808 !sock_flag(sk, SOCK_BROADCAST)) 809 goto out; 810 811 if (msg->msg_flags & MSG_CONFIRM) 812 goto do_confirm; 813 back_from_confirm: 814 815 if (!ipc.addr) 816 ipc.addr = fl4.daddr; 817 818 lock_sock(sk); 819 820 pfh.icmph.type = user_icmph.type; /* already checked */ 821 pfh.icmph.code = user_icmph.code; /* ditto */ 822 pfh.icmph.checksum = 0; 823 pfh.icmph.un.echo.id = inet->inet_sport; 824 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 825 pfh.msg = msg; 826 pfh.wcheck = 0; 827 pfh.family = AF_INET; 828 829 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 830 0, &ipc, &rt, msg->msg_flags); 831 if (err) 832 ip_flush_pending_frames(sk); 833 else 834 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 835 release_sock(sk); 836 837 out: 838 ip_rt_put(rt); 839 out_free: 840 if (free) 841 kfree(ipc.opt); 842 if (!err) { 843 icmp_out_count(sock_net(sk), user_icmph.type); 844 return len; 845 } 846 return err; 847 848 do_confirm: 849 if (msg->msg_flags & MSG_PROBE) 850 dst_confirm_neigh(&rt->dst, &fl4.daddr); 851 if (!(msg->msg_flags & MSG_PROBE) || len) 852 goto back_from_confirm; 853 err = 0; 854 goto out; 855 } 856 857 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags, 858 int *addr_len) 859 { 860 struct inet_sock *isk = inet_sk(sk); 861 int family = sk->sk_family; 862 struct sk_buff *skb; 863 int copied, err; 864 865 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 866 867 err = -EOPNOTSUPP; 868 if (flags & MSG_OOB) 869 goto out; 870 871 if (flags & MSG_ERRQUEUE) 872 return inet_recv_error(sk, msg, len, addr_len); 873 874 skb = skb_recv_datagram(sk, flags, &err); 875 if (!skb) 876 goto out; 877 878 copied = skb->len; 879 if (copied > len) { 880 msg->msg_flags |= MSG_TRUNC; 881 copied = len; 882 } 883 884 /* Don't bother checking the checksum */ 885 err = skb_copy_datagram_msg(skb, 0, msg, copied); 886 if (err) 887 goto done; 888 889 sock_recv_timestamp(msg, sk, skb); 890 891 /* Copy the address and add cmsg data. */ 892 if (family == AF_INET) { 893 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 894 895 if (sin) { 896 sin->sin_family = AF_INET; 897 sin->sin_port = 0 /* skb->h.uh->source */; 898 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 899 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 900 *addr_len = sizeof(*sin); 901 } 902 903 if (isk->cmsg_flags) 904 ip_cmsg_recv(msg, skb); 905 906 #if IS_ENABLED(CONFIG_IPV6) 907 } else if (family == AF_INET6) { 908 struct ipv6_pinfo *np = inet6_sk(sk); 909 struct ipv6hdr *ip6 = ipv6_hdr(skb); 910 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 911 912 if (sin6) { 913 sin6->sin6_family = AF_INET6; 914 sin6->sin6_port = 0; 915 sin6->sin6_addr = ip6->saddr; 916 sin6->sin6_flowinfo = 0; 917 if (np->sndflow) 918 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 919 sin6->sin6_scope_id = 920 ipv6_iface_scope_id(&sin6->sin6_addr, 921 inet6_iif(skb)); 922 *addr_len = sizeof(*sin6); 923 } 924 925 if (inet6_sk(sk)->rxopt.all) 926 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 927 if (skb->protocol == htons(ETH_P_IPV6) && 928 inet6_sk(sk)->rxopt.all) 929 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 930 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 931 ip_cmsg_recv(msg, skb); 932 #endif 933 } else { 934 BUG(); 935 } 936 937 err = copied; 938 939 done: 940 skb_free_datagram(sk, skb); 941 out: 942 pr_debug("ping_recvmsg -> %d\n", err); 943 return err; 944 } 945 EXPORT_SYMBOL_GPL(ping_recvmsg); 946 947 static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk, 948 struct sk_buff *skb) 949 { 950 enum skb_drop_reason reason; 951 952 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 953 inet_sk(sk), inet_sk(sk)->inet_num, skb); 954 if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) { 955 kfree_skb_reason(skb, reason); 956 pr_debug("ping_queue_rcv_skb -> failed\n"); 957 return reason; 958 } 959 return SKB_NOT_DROPPED_YET; 960 } 961 962 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 963 { 964 return __ping_queue_rcv_skb(sk, skb) ? -1 : 0; 965 } 966 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 967 968 969 /* 970 * All we need to do is get the socket. 971 */ 972 973 enum skb_drop_reason ping_rcv(struct sk_buff *skb) 974 { 975 enum skb_drop_reason reason = SKB_DROP_REASON_NO_SOCKET; 976 struct sock *sk; 977 struct net *net = dev_net(skb->dev); 978 struct icmphdr *icmph = icmp_hdr(skb); 979 980 /* We assume the packet has already been checked by icmp_rcv */ 981 982 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 983 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 984 985 /* Push ICMP header back */ 986 skb_push(skb, skb->data - (u8 *)icmph); 987 988 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 989 if (sk) { 990 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 991 992 pr_debug("rcv on socket %p\n", sk); 993 if (skb2) 994 reason = __ping_queue_rcv_skb(sk, skb2); 995 else 996 reason = SKB_DROP_REASON_NOMEM; 997 sock_put(sk); 998 } 999 1000 if (reason) 1001 pr_debug("no socket, dropping\n"); 1002 1003 return reason; 1004 } 1005 EXPORT_SYMBOL_GPL(ping_rcv); 1006 1007 struct proto ping_prot = { 1008 .name = "PING", 1009 .owner = THIS_MODULE, 1010 .init = ping_init_sock, 1011 .close = ping_close, 1012 .connect = ip4_datagram_connect, 1013 .disconnect = __udp_disconnect, 1014 .setsockopt = ip_setsockopt, 1015 .getsockopt = ip_getsockopt, 1016 .sendmsg = ping_v4_sendmsg, 1017 .recvmsg = ping_recvmsg, 1018 .bind = ping_bind, 1019 .backlog_rcv = ping_queue_rcv_skb, 1020 .release_cb = ip4_datagram_release_cb, 1021 .hash = ping_hash, 1022 .unhash = ping_unhash, 1023 .get_port = ping_get_port, 1024 .put_port = ping_unhash, 1025 .obj_size = sizeof(struct inet_sock), 1026 }; 1027 EXPORT_SYMBOL(ping_prot); 1028 1029 #ifdef CONFIG_PROC_FS 1030 1031 static struct sock *ping_get_first(struct seq_file *seq, int start) 1032 { 1033 struct sock *sk; 1034 struct ping_iter_state *state = seq->private; 1035 struct net *net = seq_file_net(seq); 1036 1037 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1038 ++state->bucket) { 1039 struct hlist_nulls_node *node; 1040 struct hlist_nulls_head *hslot; 1041 1042 hslot = &ping_table.hash[state->bucket]; 1043 1044 if (hlist_nulls_empty(hslot)) 1045 continue; 1046 1047 sk_nulls_for_each(sk, node, hslot) { 1048 if (net_eq(sock_net(sk), net) && 1049 sk->sk_family == state->family) 1050 goto found; 1051 } 1052 } 1053 sk = NULL; 1054 found: 1055 return sk; 1056 } 1057 1058 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1059 { 1060 struct ping_iter_state *state = seq->private; 1061 struct net *net = seq_file_net(seq); 1062 1063 do { 1064 sk = sk_nulls_next(sk); 1065 } while (sk && (!net_eq(sock_net(sk), net))); 1066 1067 if (!sk) 1068 return ping_get_first(seq, state->bucket + 1); 1069 return sk; 1070 } 1071 1072 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1073 { 1074 struct sock *sk = ping_get_first(seq, 0); 1075 1076 if (sk) 1077 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1078 --pos; 1079 return pos ? NULL : sk; 1080 } 1081 1082 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1083 __acquires(ping_table.lock) 1084 { 1085 struct ping_iter_state *state = seq->private; 1086 state->bucket = 0; 1087 state->family = family; 1088 1089 read_lock_bh(&ping_table.lock); 1090 1091 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1092 } 1093 EXPORT_SYMBOL_GPL(ping_seq_start); 1094 1095 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1096 { 1097 return ping_seq_start(seq, pos, AF_INET); 1098 } 1099 1100 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1101 { 1102 struct sock *sk; 1103 1104 if (v == SEQ_START_TOKEN) 1105 sk = ping_get_idx(seq, 0); 1106 else 1107 sk = ping_get_next(seq, v); 1108 1109 ++*pos; 1110 return sk; 1111 } 1112 EXPORT_SYMBOL_GPL(ping_seq_next); 1113 1114 void ping_seq_stop(struct seq_file *seq, void *v) 1115 __releases(ping_table.lock) 1116 { 1117 read_unlock_bh(&ping_table.lock); 1118 } 1119 EXPORT_SYMBOL_GPL(ping_seq_stop); 1120 1121 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1122 int bucket) 1123 { 1124 struct inet_sock *inet = inet_sk(sp); 1125 __be32 dest = inet->inet_daddr; 1126 __be32 src = inet->inet_rcv_saddr; 1127 __u16 destp = ntohs(inet->inet_dport); 1128 __u16 srcp = ntohs(inet->inet_sport); 1129 1130 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1131 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", 1132 bucket, src, srcp, dest, destp, sp->sk_state, 1133 sk_wmem_alloc_get(sp), 1134 sk_rmem_alloc_get(sp), 1135 0, 0L, 0, 1136 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1137 0, sock_i_ino(sp), 1138 refcount_read(&sp->sk_refcnt), sp, 1139 atomic_read(&sp->sk_drops)); 1140 } 1141 1142 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1143 { 1144 seq_setwidth(seq, 127); 1145 if (v == SEQ_START_TOKEN) 1146 seq_puts(seq, " sl local_address rem_address st tx_queue " 1147 "rx_queue tr tm->when retrnsmt uid timeout " 1148 "inode ref pointer drops"); 1149 else { 1150 struct ping_iter_state *state = seq->private; 1151 1152 ping_v4_format_sock(v, seq, state->bucket); 1153 } 1154 seq_pad(seq, '\n'); 1155 return 0; 1156 } 1157 1158 static const struct seq_operations ping_v4_seq_ops = { 1159 .start = ping_v4_seq_start, 1160 .show = ping_v4_seq_show, 1161 .next = ping_seq_next, 1162 .stop = ping_seq_stop, 1163 }; 1164 1165 static int __net_init ping_v4_proc_init_net(struct net *net) 1166 { 1167 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops, 1168 sizeof(struct ping_iter_state))) 1169 return -ENOMEM; 1170 return 0; 1171 } 1172 1173 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1174 { 1175 remove_proc_entry("icmp", net->proc_net); 1176 } 1177 1178 static struct pernet_operations ping_v4_net_ops = { 1179 .init = ping_v4_proc_init_net, 1180 .exit = ping_v4_proc_exit_net, 1181 }; 1182 1183 int __init ping_proc_init(void) 1184 { 1185 return register_pernet_subsys(&ping_v4_net_ops); 1186 } 1187 1188 void ping_proc_exit(void) 1189 { 1190 unregister_pernet_subsys(&ping_v4_net_ops); 1191 } 1192 1193 #endif 1194 1195 void __init ping_init(void) 1196 { 1197 int i; 1198 1199 for (i = 0; i < PING_HTABLE_SIZE; i++) 1200 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1201 rwlock_init(&ping_table.lock); 1202 } 1203