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 struct ping_table { 53 struct hlist_nulls_head hash[PING_HTABLE_SIZE]; 54 spinlock_t lock; 55 }; 56 57 static struct ping_table ping_table; 58 struct pingv6_ops pingv6_ops; 59 EXPORT_SYMBOL_GPL(pingv6_ops); 60 61 static u16 ping_port_rover; 62 63 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask) 64 { 65 u32 res = (num + net_hash_mix(net)) & mask; 66 67 pr_debug("hash(%u) = %u\n", num, res); 68 return res; 69 } 70 EXPORT_SYMBOL_GPL(ping_hash); 71 72 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table, 73 struct net *net, unsigned int num) 74 { 75 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)]; 76 } 77 78 int ping_get_port(struct sock *sk, unsigned short ident) 79 { 80 struct hlist_nulls_node *node; 81 struct hlist_nulls_head *hlist; 82 struct inet_sock *isk, *isk2; 83 struct sock *sk2 = NULL; 84 85 isk = inet_sk(sk); 86 spin_lock(&ping_table.lock); 87 if (ident == 0) { 88 u32 i; 89 u16 result = ping_port_rover + 1; 90 91 for (i = 0; i < (1L << 16); i++, result++) { 92 if (!result) 93 result++; /* avoid zero */ 94 hlist = ping_hashslot(&ping_table, sock_net(sk), 95 result); 96 ping_portaddr_for_each_entry(sk2, node, hlist) { 97 isk2 = inet_sk(sk2); 98 99 if (isk2->inet_num == result) 100 goto next_port; 101 } 102 103 /* found */ 104 ping_port_rover = ident = result; 105 break; 106 next_port: 107 ; 108 } 109 if (i >= (1L << 16)) 110 goto fail; 111 } else { 112 hlist = ping_hashslot(&ping_table, sock_net(sk), ident); 113 ping_portaddr_for_each_entry(sk2, node, hlist) { 114 isk2 = inet_sk(sk2); 115 116 /* BUG? Why is this reuse and not reuseaddr? ping.c 117 * doesn't turn off SO_REUSEADDR, and it doesn't expect 118 * that other ping processes can steal its packets. 119 */ 120 if ((isk2->inet_num == ident) && 121 (sk2 != sk) && 122 (!sk2->sk_reuse || !sk->sk_reuse)) 123 goto fail; 124 } 125 } 126 127 pr_debug("found port/ident = %d\n", ident); 128 isk->inet_num = ident; 129 if (sk_unhashed(sk)) { 130 pr_debug("was not hashed\n"); 131 sock_hold(sk); 132 sock_set_flag(sk, SOCK_RCU_FREE); 133 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, hlist); 134 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 135 } 136 spin_unlock(&ping_table.lock); 137 return 0; 138 139 fail: 140 spin_unlock(&ping_table.lock); 141 return 1; 142 } 143 EXPORT_SYMBOL_GPL(ping_get_port); 144 145 int ping_hash(struct sock *sk) 146 { 147 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num); 148 BUG(); /* "Please do not press this button again." */ 149 150 return 0; 151 } 152 153 void ping_unhash(struct sock *sk) 154 { 155 struct inet_sock *isk = inet_sk(sk); 156 157 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); 158 spin_lock(&ping_table.lock); 159 if (sk_hashed(sk)) { 160 hlist_nulls_del_init_rcu(&sk->sk_nulls_node); 161 sock_put(sk); 162 isk->inet_num = 0; 163 isk->inet_sport = 0; 164 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 165 } 166 spin_unlock(&ping_table.lock); 167 } 168 EXPORT_SYMBOL_GPL(ping_unhash); 169 170 /* Called under rcu_read_lock() */ 171 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) 172 { 173 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); 174 struct sock *sk = NULL; 175 struct inet_sock *isk; 176 struct hlist_nulls_node *hnode; 177 int dif, sdif; 178 179 if (skb->protocol == htons(ETH_P_IP)) { 180 dif = inet_iif(skb); 181 sdif = inet_sdif(skb); 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 dif = inet6_iif(skb); 187 sdif = inet6_sdif(skb); 188 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", 189 (int)ident, &ipv6_hdr(skb)->daddr, dif); 190 #endif 191 } else { 192 return NULL; 193 } 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 goto exit; 234 } 235 236 sk = NULL; 237 exit: 238 239 return sk; 240 } 241 242 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 243 kgid_t *high) 244 { 245 kgid_t *data = net->ipv4.ping_group_range.range; 246 unsigned int seq; 247 248 do { 249 seq = read_seqbegin(&net->ipv4.ping_group_range.lock); 250 251 *low = data[0]; 252 *high = data[1]; 253 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); 254 } 255 256 257 int ping_init_sock(struct sock *sk) 258 { 259 struct net *net = sock_net(sk); 260 kgid_t group = current_egid(); 261 struct group_info *group_info; 262 int i; 263 kgid_t low, high; 264 int ret = 0; 265 266 if (sk->sk_family == AF_INET6) 267 sk->sk_ipv6only = 1; 268 269 inet_get_ping_group_range_net(net, &low, &high); 270 if (gid_lte(low, group) && gid_lte(group, high)) 271 return 0; 272 273 group_info = get_current_groups(); 274 for (i = 0; i < group_info->ngroups; i++) { 275 kgid_t gid = group_info->gid[i]; 276 277 if (gid_lte(low, gid) && gid_lte(gid, high)) 278 goto out_release_group; 279 } 280 281 ret = -EACCES; 282 283 out_release_group: 284 put_group_info(group_info); 285 return ret; 286 } 287 EXPORT_SYMBOL_GPL(ping_init_sock); 288 289 void ping_close(struct sock *sk, long timeout) 290 { 291 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 292 inet_sk(sk), inet_sk(sk)->inet_num); 293 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt)); 294 295 sk_common_release(sk); 296 } 297 EXPORT_SYMBOL_GPL(ping_close); 298 299 static int ping_pre_connect(struct sock *sk, struct sockaddr *uaddr, 300 int addr_len) 301 { 302 /* This check is replicated from __ip4_datagram_connect() and 303 * intended to prevent BPF program called below from accessing bytes 304 * that are out of the bound specified by user in addr_len. 305 */ 306 if (addr_len < sizeof(struct sockaddr_in)) 307 return -EINVAL; 308 309 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr); 310 } 311 312 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 313 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 314 struct sockaddr *uaddr, int addr_len) 315 { 316 struct net *net = sock_net(sk); 317 if (sk->sk_family == AF_INET) { 318 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 319 u32 tb_id = RT_TABLE_LOCAL; 320 int chk_addr_ret; 321 322 if (addr_len < sizeof(*addr)) 323 return -EINVAL; 324 325 if (addr->sin_family != AF_INET && 326 !(addr->sin_family == AF_UNSPEC && 327 addr->sin_addr.s_addr == htonl(INADDR_ANY))) 328 return -EAFNOSUPPORT; 329 330 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 331 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 332 333 if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) 334 return 0; 335 336 tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id; 337 chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id); 338 339 if (chk_addr_ret == RTN_MULTICAST || 340 chk_addr_ret == RTN_BROADCAST || 341 (chk_addr_ret != RTN_LOCAL && 342 !inet_can_nonlocal_bind(net, isk))) 343 return -EADDRNOTAVAIL; 344 345 #if IS_ENABLED(CONFIG_IPV6) 346 } else if (sk->sk_family == AF_INET6) { 347 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 348 int addr_type, scoped, has_addr; 349 struct net_device *dev = NULL; 350 351 if (addr_len < sizeof(*addr)) 352 return -EINVAL; 353 354 if (addr->sin6_family != AF_INET6) 355 return -EAFNOSUPPORT; 356 357 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 358 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 359 360 addr_type = ipv6_addr_type(&addr->sin6_addr); 361 scoped = __ipv6_addr_needs_scope_id(addr_type); 362 if ((addr_type != IPV6_ADDR_ANY && 363 !(addr_type & IPV6_ADDR_UNICAST)) || 364 (scoped && !addr->sin6_scope_id)) 365 return -EINVAL; 366 367 rcu_read_lock(); 368 if (addr->sin6_scope_id) { 369 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 370 if (!dev) { 371 rcu_read_unlock(); 372 return -ENODEV; 373 } 374 } 375 376 if (!dev && sk->sk_bound_dev_if) { 377 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if); 378 if (!dev) { 379 rcu_read_unlock(); 380 return -ENODEV; 381 } 382 } 383 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 384 scoped); 385 rcu_read_unlock(); 386 387 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr || 388 addr_type == IPV6_ADDR_ANY)) 389 return -EADDRNOTAVAIL; 390 391 if (scoped) 392 sk->sk_bound_dev_if = addr->sin6_scope_id; 393 #endif 394 } else { 395 return -EAFNOSUPPORT; 396 } 397 return 0; 398 } 399 400 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 401 { 402 if (saddr->sa_family == AF_INET) { 403 struct inet_sock *isk = inet_sk(sk); 404 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 405 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 406 #if IS_ENABLED(CONFIG_IPV6) 407 } else if (saddr->sa_family == AF_INET6) { 408 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 409 struct ipv6_pinfo *np = inet6_sk(sk); 410 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 411 #endif 412 } 413 } 414 415 /* 416 * We need our own bind because there are no privileged id's == local ports. 417 * Moreover, we don't allow binding to multi- and broadcast addresses. 418 */ 419 420 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 421 { 422 struct inet_sock *isk = inet_sk(sk); 423 unsigned short snum; 424 int err; 425 int dif = sk->sk_bound_dev_if; 426 427 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 428 if (err) 429 return err; 430 431 lock_sock(sk); 432 433 err = -EINVAL; 434 if (isk->inet_num != 0) 435 goto out; 436 437 err = -EADDRINUSE; 438 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 439 if (ping_get_port(sk, snum) != 0) { 440 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */ 441 sk->sk_bound_dev_if = dif; 442 goto out; 443 } 444 ping_set_saddr(sk, uaddr); 445 446 pr_debug("after bind(): num = %hu, dif = %d\n", 447 isk->inet_num, 448 sk->sk_bound_dev_if); 449 450 err = 0; 451 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 452 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 453 #if IS_ENABLED(CONFIG_IPV6) 454 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 455 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 456 #endif 457 458 if (snum) 459 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 460 isk->inet_sport = htons(isk->inet_num); 461 isk->inet_daddr = 0; 462 isk->inet_dport = 0; 463 464 #if IS_ENABLED(CONFIG_IPV6) 465 if (sk->sk_family == AF_INET6) 466 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 467 #endif 468 469 sk_dst_reset(sk); 470 out: 471 release_sock(sk); 472 pr_debug("ping_v4_bind -> %d\n", err); 473 return err; 474 } 475 EXPORT_SYMBOL_GPL(ping_bind); 476 477 /* 478 * Is this a supported type of ICMP message? 479 */ 480 481 static inline int ping_supported(int family, int type, int code) 482 { 483 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 484 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) || 485 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) || 486 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0); 487 } 488 489 /* 490 * This routine is called by the ICMP module when it gets some 491 * sort of error condition. 492 */ 493 494 void ping_err(struct sk_buff *skb, int offset, u32 info) 495 { 496 int family; 497 struct icmphdr *icmph; 498 struct inet_sock *inet_sock; 499 int type; 500 int code; 501 struct net *net = dev_net(skb->dev); 502 struct sock *sk; 503 int harderr; 504 int err; 505 506 if (skb->protocol == htons(ETH_P_IP)) { 507 family = AF_INET; 508 type = icmp_hdr(skb)->type; 509 code = icmp_hdr(skb)->code; 510 icmph = (struct icmphdr *)(skb->data + offset); 511 } else if (skb->protocol == htons(ETH_P_IPV6)) { 512 family = AF_INET6; 513 type = icmp6_hdr(skb)->icmp6_type; 514 code = icmp6_hdr(skb)->icmp6_code; 515 icmph = (struct icmphdr *) (skb->data + offset); 516 } else { 517 BUG(); 518 } 519 520 /* We assume the packet has already been checked by icmp_unreach */ 521 522 if (!ping_supported(family, icmph->type, icmph->code)) 523 return; 524 525 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 526 skb->protocol, type, code, ntohs(icmph->un.echo.id), 527 ntohs(icmph->un.echo.sequence)); 528 529 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 530 if (!sk) { 531 pr_debug("no socket, dropping\n"); 532 return; /* No socket for error */ 533 } 534 pr_debug("err on socket %p\n", sk); 535 536 err = 0; 537 harderr = 0; 538 inet_sock = inet_sk(sk); 539 540 if (skb->protocol == htons(ETH_P_IP)) { 541 switch (type) { 542 default: 543 case ICMP_TIME_EXCEEDED: 544 err = EHOSTUNREACH; 545 break; 546 case ICMP_SOURCE_QUENCH: 547 /* This is not a real error but ping wants to see it. 548 * Report it with some fake errno. 549 */ 550 err = EREMOTEIO; 551 break; 552 case ICMP_PARAMETERPROB: 553 err = EPROTO; 554 harderr = 1; 555 break; 556 case ICMP_DEST_UNREACH: 557 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 558 ipv4_sk_update_pmtu(skb, sk, info); 559 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 560 err = EMSGSIZE; 561 harderr = 1; 562 break; 563 } 564 goto out; 565 } 566 err = EHOSTUNREACH; 567 if (code <= NR_ICMP_UNREACH) { 568 harderr = icmp_err_convert[code].fatal; 569 err = icmp_err_convert[code].errno; 570 } 571 break; 572 case ICMP_REDIRECT: 573 /* See ICMP_SOURCE_QUENCH */ 574 ipv4_sk_redirect(skb, sk); 575 err = EREMOTEIO; 576 break; 577 } 578 #if IS_ENABLED(CONFIG_IPV6) 579 } else if (skb->protocol == htons(ETH_P_IPV6)) { 580 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 581 #endif 582 } 583 584 /* 585 * RFC1122: OK. Passes ICMP errors back to application, as per 586 * 4.1.3.3. 587 */ 588 if ((family == AF_INET && !inet_sock->recverr) || 589 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 590 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 591 goto out; 592 } else { 593 if (family == AF_INET) { 594 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 595 info, (u8 *)icmph); 596 #if IS_ENABLED(CONFIG_IPV6) 597 } else if (family == AF_INET6) { 598 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 599 info, (u8 *)icmph); 600 #endif 601 } 602 } 603 sk->sk_err = err; 604 sk_error_report(sk); 605 out: 606 return; 607 } 608 EXPORT_SYMBOL_GPL(ping_err); 609 610 /* 611 * Copy and checksum an ICMP Echo packet from user space into a buffer 612 * starting from the payload. 613 */ 614 615 int ping_getfrag(void *from, char *to, 616 int offset, int fraglen, int odd, struct sk_buff *skb) 617 { 618 struct pingfakehdr *pfh = from; 619 620 if (offset == 0) { 621 fraglen -= sizeof(struct icmphdr); 622 if (fraglen < 0) 623 BUG(); 624 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), 625 fraglen, &pfh->wcheck, 626 &pfh->msg->msg_iter)) 627 return -EFAULT; 628 } else if (offset < sizeof(struct icmphdr)) { 629 BUG(); 630 } else { 631 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, 632 &pfh->msg->msg_iter)) 633 return -EFAULT; 634 } 635 636 #if IS_ENABLED(CONFIG_IPV6) 637 /* For IPv6, checksum each skb as we go along, as expected by 638 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 639 * wcheck, it will be finalized in ping_v4_push_pending_frames. 640 */ 641 if (pfh->family == AF_INET6) { 642 skb->csum = pfh->wcheck; 643 skb->ip_summed = CHECKSUM_NONE; 644 pfh->wcheck = 0; 645 } 646 #endif 647 648 return 0; 649 } 650 EXPORT_SYMBOL_GPL(ping_getfrag); 651 652 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 653 struct flowi4 *fl4) 654 { 655 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 656 657 if (!skb) 658 return 0; 659 pfh->wcheck = csum_partial((char *)&pfh->icmph, 660 sizeof(struct icmphdr), pfh->wcheck); 661 pfh->icmph.checksum = csum_fold(pfh->wcheck); 662 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 663 skb->ip_summed = CHECKSUM_NONE; 664 return ip_push_pending_frames(sk, fl4); 665 } 666 667 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 668 void *user_icmph, size_t icmph_len) 669 { 670 u8 type, code; 671 672 if (len > 0xFFFF) 673 return -EMSGSIZE; 674 675 /* Must have at least a full ICMP header. */ 676 if (len < icmph_len) 677 return -EINVAL; 678 679 /* 680 * Check the flags. 681 */ 682 683 /* Mirror BSD error message compatibility */ 684 if (msg->msg_flags & MSG_OOB) 685 return -EOPNOTSUPP; 686 687 /* 688 * Fetch the ICMP header provided by the userland. 689 * iovec is modified! The ICMP header is consumed. 690 */ 691 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 692 return -EFAULT; 693 694 if (family == AF_INET) { 695 type = ((struct icmphdr *) user_icmph)->type; 696 code = ((struct icmphdr *) user_icmph)->code; 697 #if IS_ENABLED(CONFIG_IPV6) 698 } else if (family == AF_INET6) { 699 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 700 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 701 #endif 702 } else { 703 BUG(); 704 } 705 706 if (!ping_supported(family, type, code)) 707 return -EINVAL; 708 709 return 0; 710 } 711 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 712 713 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 714 { 715 struct net *net = sock_net(sk); 716 struct flowi4 fl4; 717 struct inet_sock *inet = inet_sk(sk); 718 struct ipcm_cookie ipc; 719 struct icmphdr user_icmph; 720 struct pingfakehdr pfh; 721 struct rtable *rt = NULL; 722 struct ip_options_data opt_copy; 723 int free = 0; 724 __be32 saddr, daddr, faddr; 725 u8 tos; 726 int err; 727 728 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 729 730 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 731 sizeof(user_icmph)); 732 if (err) 733 return err; 734 735 /* 736 * Get and verify the address. 737 */ 738 739 if (msg->msg_name) { 740 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 741 if (msg->msg_namelen < sizeof(*usin)) 742 return -EINVAL; 743 if (usin->sin_family != AF_INET) 744 return -EAFNOSUPPORT; 745 daddr = usin->sin_addr.s_addr; 746 /* no remote port */ 747 } else { 748 if (sk->sk_state != TCP_ESTABLISHED) 749 return -EDESTADDRREQ; 750 daddr = inet->inet_daddr; 751 /* no remote port */ 752 } 753 754 ipcm_init_sk(&ipc, inet); 755 756 if (msg->msg_controllen) { 757 err = ip_cmsg_send(sk, msg, &ipc, false); 758 if (unlikely(err)) { 759 kfree(ipc.opt); 760 return err; 761 } 762 if (ipc.opt) 763 free = 1; 764 } 765 if (!ipc.opt) { 766 struct ip_options_rcu *inet_opt; 767 768 rcu_read_lock(); 769 inet_opt = rcu_dereference(inet->inet_opt); 770 if (inet_opt) { 771 memcpy(&opt_copy, inet_opt, 772 sizeof(*inet_opt) + inet_opt->opt.optlen); 773 ipc.opt = &opt_copy.opt; 774 } 775 rcu_read_unlock(); 776 } 777 778 saddr = ipc.addr; 779 ipc.addr = faddr = daddr; 780 781 if (ipc.opt && ipc.opt->opt.srr) { 782 if (!daddr) { 783 err = -EINVAL; 784 goto out_free; 785 } 786 faddr = ipc.opt->opt.faddr; 787 } 788 tos = get_rttos(&ipc, inet); 789 if (sock_flag(sk, SOCK_LOCALROUTE) || 790 (msg->msg_flags & MSG_DONTROUTE) || 791 (ipc.opt && ipc.opt->opt.is_strictroute)) { 792 tos |= RTO_ONLINK; 793 } 794 795 if (ipv4_is_multicast(daddr)) { 796 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 797 ipc.oif = inet->mc_index; 798 if (!saddr) 799 saddr = inet->mc_addr; 800 } else if (!ipc.oif) 801 ipc.oif = inet->uc_index; 802 803 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, 804 RT_SCOPE_UNIVERSE, sk->sk_protocol, 805 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 806 sk->sk_uid); 807 808 fl4.fl4_icmp_type = user_icmph.type; 809 fl4.fl4_icmp_code = user_icmph.code; 810 811 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4)); 812 rt = ip_route_output_flow(net, &fl4, sk); 813 if (IS_ERR(rt)) { 814 err = PTR_ERR(rt); 815 rt = NULL; 816 if (err == -ENETUNREACH) 817 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 818 goto out; 819 } 820 821 err = -EACCES; 822 if ((rt->rt_flags & RTCF_BROADCAST) && 823 !sock_flag(sk, SOCK_BROADCAST)) 824 goto out; 825 826 if (msg->msg_flags & MSG_CONFIRM) 827 goto do_confirm; 828 back_from_confirm: 829 830 if (!ipc.addr) 831 ipc.addr = fl4.daddr; 832 833 lock_sock(sk); 834 835 pfh.icmph.type = user_icmph.type; /* already checked */ 836 pfh.icmph.code = user_icmph.code; /* ditto */ 837 pfh.icmph.checksum = 0; 838 pfh.icmph.un.echo.id = inet->inet_sport; 839 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 840 pfh.msg = msg; 841 pfh.wcheck = 0; 842 pfh.family = AF_INET; 843 844 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 845 0, &ipc, &rt, msg->msg_flags); 846 if (err) 847 ip_flush_pending_frames(sk); 848 else 849 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 850 release_sock(sk); 851 852 out: 853 ip_rt_put(rt); 854 out_free: 855 if (free) 856 kfree(ipc.opt); 857 if (!err) { 858 icmp_out_count(sock_net(sk), user_icmph.type); 859 return len; 860 } 861 return err; 862 863 do_confirm: 864 if (msg->msg_flags & MSG_PROBE) 865 dst_confirm_neigh(&rt->dst, &fl4.daddr); 866 if (!(msg->msg_flags & MSG_PROBE) || len) 867 goto back_from_confirm; 868 err = 0; 869 goto out; 870 } 871 872 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags, 873 int *addr_len) 874 { 875 struct inet_sock *isk = inet_sk(sk); 876 int family = sk->sk_family; 877 struct sk_buff *skb; 878 int copied, err; 879 880 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 881 882 err = -EOPNOTSUPP; 883 if (flags & MSG_OOB) 884 goto out; 885 886 if (flags & MSG_ERRQUEUE) 887 return inet_recv_error(sk, msg, len, addr_len); 888 889 skb = skb_recv_datagram(sk, flags, &err); 890 if (!skb) 891 goto out; 892 893 copied = skb->len; 894 if (copied > len) { 895 msg->msg_flags |= MSG_TRUNC; 896 copied = len; 897 } 898 899 /* Don't bother checking the checksum */ 900 err = skb_copy_datagram_msg(skb, 0, msg, copied); 901 if (err) 902 goto done; 903 904 sock_recv_timestamp(msg, sk, skb); 905 906 /* Copy the address and add cmsg data. */ 907 if (family == AF_INET) { 908 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 909 910 if (sin) { 911 sin->sin_family = AF_INET; 912 sin->sin_port = 0 /* skb->h.uh->source */; 913 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 914 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 915 *addr_len = sizeof(*sin); 916 } 917 918 if (isk->cmsg_flags) 919 ip_cmsg_recv(msg, skb); 920 921 #if IS_ENABLED(CONFIG_IPV6) 922 } else if (family == AF_INET6) { 923 struct ipv6_pinfo *np = inet6_sk(sk); 924 struct ipv6hdr *ip6 = ipv6_hdr(skb); 925 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 926 927 if (sin6) { 928 sin6->sin6_family = AF_INET6; 929 sin6->sin6_port = 0; 930 sin6->sin6_addr = ip6->saddr; 931 sin6->sin6_flowinfo = 0; 932 if (np->sndflow) 933 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 934 sin6->sin6_scope_id = 935 ipv6_iface_scope_id(&sin6->sin6_addr, 936 inet6_iif(skb)); 937 *addr_len = sizeof(*sin6); 938 } 939 940 if (inet6_sk(sk)->rxopt.all) 941 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 942 if (skb->protocol == htons(ETH_P_IPV6) && 943 inet6_sk(sk)->rxopt.all) 944 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 945 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 946 ip_cmsg_recv(msg, skb); 947 #endif 948 } else { 949 BUG(); 950 } 951 952 err = copied; 953 954 done: 955 skb_free_datagram(sk, skb); 956 out: 957 pr_debug("ping_recvmsg -> %d\n", err); 958 return err; 959 } 960 EXPORT_SYMBOL_GPL(ping_recvmsg); 961 962 static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk, 963 struct sk_buff *skb) 964 { 965 enum skb_drop_reason reason; 966 967 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 968 inet_sk(sk), inet_sk(sk)->inet_num, skb); 969 if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) { 970 kfree_skb_reason(skb, reason); 971 pr_debug("ping_queue_rcv_skb -> failed\n"); 972 return reason; 973 } 974 return SKB_NOT_DROPPED_YET; 975 } 976 977 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 978 { 979 return __ping_queue_rcv_skb(sk, skb) ? -1 : 0; 980 } 981 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 982 983 984 /* 985 * All we need to do is get the socket. 986 */ 987 988 enum skb_drop_reason ping_rcv(struct sk_buff *skb) 989 { 990 enum skb_drop_reason reason = SKB_DROP_REASON_NO_SOCKET; 991 struct sock *sk; 992 struct net *net = dev_net(skb->dev); 993 struct icmphdr *icmph = icmp_hdr(skb); 994 995 /* We assume the packet has already been checked by icmp_rcv */ 996 997 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 998 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 999 1000 /* Push ICMP header back */ 1001 skb_push(skb, skb->data - (u8 *)icmph); 1002 1003 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 1004 if (sk) { 1005 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 1006 1007 pr_debug("rcv on socket %p\n", sk); 1008 if (skb2) 1009 reason = __ping_queue_rcv_skb(sk, skb2); 1010 else 1011 reason = SKB_DROP_REASON_NOMEM; 1012 } 1013 1014 if (reason) 1015 pr_debug("no socket, dropping\n"); 1016 1017 return reason; 1018 } 1019 EXPORT_SYMBOL_GPL(ping_rcv); 1020 1021 struct proto ping_prot = { 1022 .name = "PING", 1023 .owner = THIS_MODULE, 1024 .init = ping_init_sock, 1025 .close = ping_close, 1026 .pre_connect = ping_pre_connect, 1027 .connect = ip4_datagram_connect, 1028 .disconnect = __udp_disconnect, 1029 .setsockopt = ip_setsockopt, 1030 .getsockopt = ip_getsockopt, 1031 .sendmsg = ping_v4_sendmsg, 1032 .recvmsg = ping_recvmsg, 1033 .bind = ping_bind, 1034 .backlog_rcv = ping_queue_rcv_skb, 1035 .release_cb = ip4_datagram_release_cb, 1036 .hash = ping_hash, 1037 .unhash = ping_unhash, 1038 .get_port = ping_get_port, 1039 .put_port = ping_unhash, 1040 .obj_size = sizeof(struct inet_sock), 1041 }; 1042 EXPORT_SYMBOL(ping_prot); 1043 1044 #ifdef CONFIG_PROC_FS 1045 1046 static struct sock *ping_get_first(struct seq_file *seq, int start) 1047 { 1048 struct sock *sk; 1049 struct ping_iter_state *state = seq->private; 1050 struct net *net = seq_file_net(seq); 1051 1052 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1053 ++state->bucket) { 1054 struct hlist_nulls_node *node; 1055 struct hlist_nulls_head *hslot; 1056 1057 hslot = &ping_table.hash[state->bucket]; 1058 1059 if (hlist_nulls_empty(hslot)) 1060 continue; 1061 1062 sk_nulls_for_each(sk, node, hslot) { 1063 if (net_eq(sock_net(sk), net) && 1064 sk->sk_family == state->family) 1065 goto found; 1066 } 1067 } 1068 sk = NULL; 1069 found: 1070 return sk; 1071 } 1072 1073 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1074 { 1075 struct ping_iter_state *state = seq->private; 1076 struct net *net = seq_file_net(seq); 1077 1078 do { 1079 sk = sk_nulls_next(sk); 1080 } while (sk && (!net_eq(sock_net(sk), net))); 1081 1082 if (!sk) 1083 return ping_get_first(seq, state->bucket + 1); 1084 return sk; 1085 } 1086 1087 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1088 { 1089 struct sock *sk = ping_get_first(seq, 0); 1090 1091 if (sk) 1092 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1093 --pos; 1094 return pos ? NULL : sk; 1095 } 1096 1097 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1098 __acquires(RCU) 1099 { 1100 struct ping_iter_state *state = seq->private; 1101 state->bucket = 0; 1102 state->family = family; 1103 1104 rcu_read_lock(); 1105 1106 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1107 } 1108 EXPORT_SYMBOL_GPL(ping_seq_start); 1109 1110 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1111 { 1112 return ping_seq_start(seq, pos, AF_INET); 1113 } 1114 1115 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1116 { 1117 struct sock *sk; 1118 1119 if (v == SEQ_START_TOKEN) 1120 sk = ping_get_idx(seq, 0); 1121 else 1122 sk = ping_get_next(seq, v); 1123 1124 ++*pos; 1125 return sk; 1126 } 1127 EXPORT_SYMBOL_GPL(ping_seq_next); 1128 1129 void ping_seq_stop(struct seq_file *seq, void *v) 1130 __releases(RCU) 1131 { 1132 rcu_read_unlock(); 1133 } 1134 EXPORT_SYMBOL_GPL(ping_seq_stop); 1135 1136 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1137 int bucket) 1138 { 1139 struct inet_sock *inet = inet_sk(sp); 1140 __be32 dest = inet->inet_daddr; 1141 __be32 src = inet->inet_rcv_saddr; 1142 __u16 destp = ntohs(inet->inet_dport); 1143 __u16 srcp = ntohs(inet->inet_sport); 1144 1145 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1146 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", 1147 bucket, src, srcp, dest, destp, sp->sk_state, 1148 sk_wmem_alloc_get(sp), 1149 sk_rmem_alloc_get(sp), 1150 0, 0L, 0, 1151 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1152 0, sock_i_ino(sp), 1153 refcount_read(&sp->sk_refcnt), sp, 1154 atomic_read(&sp->sk_drops)); 1155 } 1156 1157 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1158 { 1159 seq_setwidth(seq, 127); 1160 if (v == SEQ_START_TOKEN) 1161 seq_puts(seq, " sl local_address rem_address st tx_queue " 1162 "rx_queue tr tm->when retrnsmt uid timeout " 1163 "inode ref pointer drops"); 1164 else { 1165 struct ping_iter_state *state = seq->private; 1166 1167 ping_v4_format_sock(v, seq, state->bucket); 1168 } 1169 seq_pad(seq, '\n'); 1170 return 0; 1171 } 1172 1173 static const struct seq_operations ping_v4_seq_ops = { 1174 .start = ping_v4_seq_start, 1175 .show = ping_v4_seq_show, 1176 .next = ping_seq_next, 1177 .stop = ping_seq_stop, 1178 }; 1179 1180 static int __net_init ping_v4_proc_init_net(struct net *net) 1181 { 1182 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops, 1183 sizeof(struct ping_iter_state))) 1184 return -ENOMEM; 1185 return 0; 1186 } 1187 1188 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1189 { 1190 remove_proc_entry("icmp", net->proc_net); 1191 } 1192 1193 static struct pernet_operations ping_v4_net_ops = { 1194 .init = ping_v4_proc_init_net, 1195 .exit = ping_v4_proc_exit_net, 1196 }; 1197 1198 int __init ping_proc_init(void) 1199 { 1200 return register_pernet_subsys(&ping_v4_net_ops); 1201 } 1202 1203 void ping_proc_exit(void) 1204 { 1205 unregister_pernet_subsys(&ping_v4_net_ops); 1206 } 1207 1208 #endif 1209 1210 void __init ping_init(void) 1211 { 1212 int i; 1213 1214 for (i = 0; i < PING_HTABLE_SIZE; i++) 1215 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1216 spin_lock_init(&ping_table.lock); 1217 } 1218