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 spinlock_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 spin_lock(&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 sock_set_flag(sk, SOCK_RCU_FREE); 132 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, hlist); 133 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 134 } 135 spin_unlock(&ping_table.lock); 136 return 0; 137 138 fail: 139 spin_unlock(&ping_table.lock); 140 return 1; 141 } 142 EXPORT_SYMBOL_GPL(ping_get_port); 143 144 int ping_hash(struct sock *sk) 145 { 146 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num); 147 BUG(); /* "Please do not press this button again." */ 148 149 return 0; 150 } 151 152 void ping_unhash(struct sock *sk) 153 { 154 struct inet_sock *isk = inet_sk(sk); 155 156 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); 157 spin_lock(&ping_table.lock); 158 if (sk_hashed(sk)) { 159 hlist_nulls_del_init_rcu(&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 spin_unlock(&ping_table.lock); 166 } 167 EXPORT_SYMBOL_GPL(ping_unhash); 168 169 /* Called under rcu_read_lock() */ 170 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) 171 { 172 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); 173 struct sock *sk = NULL; 174 struct inet_sock *isk; 175 struct hlist_nulls_node *hnode; 176 int dif, sdif; 177 178 if (skb->protocol == htons(ETH_P_IP)) { 179 dif = inet_iif(skb); 180 sdif = inet_sdif(skb); 181 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n", 182 (int)ident, &ip_hdr(skb)->daddr, dif); 183 #if IS_ENABLED(CONFIG_IPV6) 184 } else if (skb->protocol == htons(ETH_P_IPV6)) { 185 dif = inet6_iif(skb); 186 sdif = inet6_sdif(skb); 187 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", 188 (int)ident, &ipv6_hdr(skb)->daddr, dif); 189 #endif 190 } else { 191 return NULL; 192 } 193 194 ping_portaddr_for_each_entry(sk, hnode, hslot) { 195 isk = inet_sk(sk); 196 197 pr_debug("iterate\n"); 198 if (isk->inet_num != ident) 199 continue; 200 201 if (skb->protocol == htons(ETH_P_IP) && 202 sk->sk_family == AF_INET) { 203 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, 204 (int) isk->inet_num, &isk->inet_rcv_saddr, 205 sk->sk_bound_dev_if); 206 207 if (isk->inet_rcv_saddr && 208 isk->inet_rcv_saddr != ip_hdr(skb)->daddr) 209 continue; 210 #if IS_ENABLED(CONFIG_IPV6) 211 } else if (skb->protocol == htons(ETH_P_IPV6) && 212 sk->sk_family == AF_INET6) { 213 214 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, 215 (int) isk->inet_num, 216 &sk->sk_v6_rcv_saddr, 217 sk->sk_bound_dev_if); 218 219 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 220 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, 221 &ipv6_hdr(skb)->daddr)) 222 continue; 223 #endif 224 } else { 225 continue; 226 } 227 228 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif && 229 sk->sk_bound_dev_if != sdif) 230 continue; 231 232 goto exit; 233 } 234 235 sk = NULL; 236 exit: 237 238 return sk; 239 } 240 241 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 242 kgid_t *high) 243 { 244 kgid_t *data = net->ipv4.ping_group_range.range; 245 unsigned int seq; 246 247 do { 248 seq = read_seqbegin(&net->ipv4.ping_group_range.lock); 249 250 *low = data[0]; 251 *high = data[1]; 252 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); 253 } 254 255 256 int ping_init_sock(struct sock *sk) 257 { 258 struct net *net = sock_net(sk); 259 kgid_t group = current_egid(); 260 struct group_info *group_info; 261 int i; 262 kgid_t low, high; 263 int ret = 0; 264 265 if (sk->sk_family == AF_INET6) 266 sk->sk_ipv6only = 1; 267 268 inet_get_ping_group_range_net(net, &low, &high); 269 if (gid_lte(low, group) && gid_lte(group, high)) 270 return 0; 271 272 group_info = get_current_groups(); 273 for (i = 0; i < group_info->ngroups; i++) { 274 kgid_t gid = group_info->gid[i]; 275 276 if (gid_lte(low, gid) && gid_lte(gid, high)) 277 goto out_release_group; 278 } 279 280 ret = -EACCES; 281 282 out_release_group: 283 put_group_info(group_info); 284 return ret; 285 } 286 EXPORT_SYMBOL_GPL(ping_init_sock); 287 288 void ping_close(struct sock *sk, long timeout) 289 { 290 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 291 inet_sk(sk), inet_sk(sk)->inet_num); 292 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt)); 293 294 sk_common_release(sk); 295 } 296 EXPORT_SYMBOL_GPL(ping_close); 297 298 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 299 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 300 struct sockaddr *uaddr, int addr_len) 301 { 302 struct net *net = sock_net(sk); 303 if (sk->sk_family == AF_INET) { 304 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 305 u32 tb_id = RT_TABLE_LOCAL; 306 int chk_addr_ret; 307 308 if (addr_len < sizeof(*addr)) 309 return -EINVAL; 310 311 if (addr->sin_family != AF_INET && 312 !(addr->sin_family == AF_UNSPEC && 313 addr->sin_addr.s_addr == htonl(INADDR_ANY))) 314 return -EAFNOSUPPORT; 315 316 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 317 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 318 319 if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) 320 return 0; 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 (chk_addr_ret == RTN_MULTICAST || 326 chk_addr_ret == RTN_BROADCAST || 327 (chk_addr_ret != RTN_LOCAL && 328 !inet_can_nonlocal_bind(net, isk))) 329 return -EADDRNOTAVAIL; 330 331 #if IS_ENABLED(CONFIG_IPV6) 332 } else if (sk->sk_family == AF_INET6) { 333 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 334 int addr_type, scoped, has_addr; 335 struct net_device *dev = NULL; 336 337 if (addr_len < sizeof(*addr)) 338 return -EINVAL; 339 340 if (addr->sin6_family != AF_INET6) 341 return -EAFNOSUPPORT; 342 343 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 344 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 345 346 addr_type = ipv6_addr_type(&addr->sin6_addr); 347 scoped = __ipv6_addr_needs_scope_id(addr_type); 348 if ((addr_type != IPV6_ADDR_ANY && 349 !(addr_type & IPV6_ADDR_UNICAST)) || 350 (scoped && !addr->sin6_scope_id)) 351 return -EINVAL; 352 353 rcu_read_lock(); 354 if (addr->sin6_scope_id) { 355 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 356 if (!dev) { 357 rcu_read_unlock(); 358 return -ENODEV; 359 } 360 } 361 362 if (!dev && sk->sk_bound_dev_if) { 363 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if); 364 if (!dev) { 365 rcu_read_unlock(); 366 return -ENODEV; 367 } 368 } 369 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 370 scoped); 371 rcu_read_unlock(); 372 373 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr || 374 addr_type == IPV6_ADDR_ANY)) 375 return -EADDRNOTAVAIL; 376 377 if (scoped) 378 sk->sk_bound_dev_if = addr->sin6_scope_id; 379 #endif 380 } else { 381 return -EAFNOSUPPORT; 382 } 383 return 0; 384 } 385 386 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 387 { 388 if (saddr->sa_family == AF_INET) { 389 struct inet_sock *isk = inet_sk(sk); 390 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 391 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 392 #if IS_ENABLED(CONFIG_IPV6) 393 } else if (saddr->sa_family == AF_INET6) { 394 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 395 struct ipv6_pinfo *np = inet6_sk(sk); 396 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 397 #endif 398 } 399 } 400 401 /* 402 * We need our own bind because there are no privileged id's == local ports. 403 * Moreover, we don't allow binding to multi- and broadcast addresses. 404 */ 405 406 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 407 { 408 struct inet_sock *isk = inet_sk(sk); 409 unsigned short snum; 410 int err; 411 int dif = sk->sk_bound_dev_if; 412 413 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 414 if (err) 415 return err; 416 417 lock_sock(sk); 418 419 err = -EINVAL; 420 if (isk->inet_num != 0) 421 goto out; 422 423 err = -EADDRINUSE; 424 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 425 if (ping_get_port(sk, snum) != 0) { 426 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */ 427 sk->sk_bound_dev_if = dif; 428 goto out; 429 } 430 ping_set_saddr(sk, uaddr); 431 432 pr_debug("after bind(): num = %hu, dif = %d\n", 433 isk->inet_num, 434 sk->sk_bound_dev_if); 435 436 err = 0; 437 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 438 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 439 #if IS_ENABLED(CONFIG_IPV6) 440 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 441 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 442 #endif 443 444 if (snum) 445 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 446 isk->inet_sport = htons(isk->inet_num); 447 isk->inet_daddr = 0; 448 isk->inet_dport = 0; 449 450 #if IS_ENABLED(CONFIG_IPV6) 451 if (sk->sk_family == AF_INET6) 452 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 453 #endif 454 455 sk_dst_reset(sk); 456 out: 457 release_sock(sk); 458 pr_debug("ping_v4_bind -> %d\n", err); 459 return err; 460 } 461 EXPORT_SYMBOL_GPL(ping_bind); 462 463 /* 464 * Is this a supported type of ICMP message? 465 */ 466 467 static inline int ping_supported(int family, int type, int code) 468 { 469 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 470 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) || 471 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) || 472 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0); 473 } 474 475 /* 476 * This routine is called by the ICMP module when it gets some 477 * sort of error condition. 478 */ 479 480 void ping_err(struct sk_buff *skb, int offset, u32 info) 481 { 482 int family; 483 struct icmphdr *icmph; 484 struct inet_sock *inet_sock; 485 int type; 486 int code; 487 struct net *net = dev_net(skb->dev); 488 struct sock *sk; 489 int harderr; 490 int err; 491 492 if (skb->protocol == htons(ETH_P_IP)) { 493 family = AF_INET; 494 type = icmp_hdr(skb)->type; 495 code = icmp_hdr(skb)->code; 496 icmph = (struct icmphdr *)(skb->data + offset); 497 } else if (skb->protocol == htons(ETH_P_IPV6)) { 498 family = AF_INET6; 499 type = icmp6_hdr(skb)->icmp6_type; 500 code = icmp6_hdr(skb)->icmp6_code; 501 icmph = (struct icmphdr *) (skb->data + offset); 502 } else { 503 BUG(); 504 } 505 506 /* We assume the packet has already been checked by icmp_unreach */ 507 508 if (!ping_supported(family, icmph->type, icmph->code)) 509 return; 510 511 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 512 skb->protocol, type, code, ntohs(icmph->un.echo.id), 513 ntohs(icmph->un.echo.sequence)); 514 515 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 516 if (!sk) { 517 pr_debug("no socket, dropping\n"); 518 return; /* No socket for error */ 519 } 520 pr_debug("err on socket %p\n", sk); 521 522 err = 0; 523 harderr = 0; 524 inet_sock = inet_sk(sk); 525 526 if (skb->protocol == htons(ETH_P_IP)) { 527 switch (type) { 528 default: 529 case ICMP_TIME_EXCEEDED: 530 err = EHOSTUNREACH; 531 break; 532 case ICMP_SOURCE_QUENCH: 533 /* This is not a real error but ping wants to see it. 534 * Report it with some fake errno. 535 */ 536 err = EREMOTEIO; 537 break; 538 case ICMP_PARAMETERPROB: 539 err = EPROTO; 540 harderr = 1; 541 break; 542 case ICMP_DEST_UNREACH: 543 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 544 ipv4_sk_update_pmtu(skb, sk, info); 545 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 546 err = EMSGSIZE; 547 harderr = 1; 548 break; 549 } 550 goto out; 551 } 552 err = EHOSTUNREACH; 553 if (code <= NR_ICMP_UNREACH) { 554 harderr = icmp_err_convert[code].fatal; 555 err = icmp_err_convert[code].errno; 556 } 557 break; 558 case ICMP_REDIRECT: 559 /* See ICMP_SOURCE_QUENCH */ 560 ipv4_sk_redirect(skb, sk); 561 err = EREMOTEIO; 562 break; 563 } 564 #if IS_ENABLED(CONFIG_IPV6) 565 } else if (skb->protocol == htons(ETH_P_IPV6)) { 566 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 567 #endif 568 } 569 570 /* 571 * RFC1122: OK. Passes ICMP errors back to application, as per 572 * 4.1.3.3. 573 */ 574 if ((family == AF_INET && !inet_sock->recverr) || 575 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 576 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 577 goto out; 578 } else { 579 if (family == AF_INET) { 580 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 581 info, (u8 *)icmph); 582 #if IS_ENABLED(CONFIG_IPV6) 583 } else if (family == AF_INET6) { 584 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 585 info, (u8 *)icmph); 586 #endif 587 } 588 } 589 sk->sk_err = err; 590 sk_error_report(sk); 591 out: 592 return; 593 } 594 EXPORT_SYMBOL_GPL(ping_err); 595 596 /* 597 * Copy and checksum an ICMP Echo packet from user space into a buffer 598 * starting from the payload. 599 */ 600 601 int ping_getfrag(void *from, char *to, 602 int offset, int fraglen, int odd, struct sk_buff *skb) 603 { 604 struct pingfakehdr *pfh = from; 605 606 if (offset == 0) { 607 fraglen -= sizeof(struct icmphdr); 608 if (fraglen < 0) 609 BUG(); 610 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), 611 fraglen, &pfh->wcheck, 612 &pfh->msg->msg_iter)) 613 return -EFAULT; 614 } else if (offset < sizeof(struct icmphdr)) { 615 BUG(); 616 } else { 617 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, 618 &pfh->msg->msg_iter)) 619 return -EFAULT; 620 } 621 622 #if IS_ENABLED(CONFIG_IPV6) 623 /* For IPv6, checksum each skb as we go along, as expected by 624 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 625 * wcheck, it will be finalized in ping_v4_push_pending_frames. 626 */ 627 if (pfh->family == AF_INET6) { 628 skb->csum = pfh->wcheck; 629 skb->ip_summed = CHECKSUM_NONE; 630 pfh->wcheck = 0; 631 } 632 #endif 633 634 return 0; 635 } 636 EXPORT_SYMBOL_GPL(ping_getfrag); 637 638 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 639 struct flowi4 *fl4) 640 { 641 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 642 643 if (!skb) 644 return 0; 645 pfh->wcheck = csum_partial((char *)&pfh->icmph, 646 sizeof(struct icmphdr), pfh->wcheck); 647 pfh->icmph.checksum = csum_fold(pfh->wcheck); 648 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 649 skb->ip_summed = CHECKSUM_NONE; 650 return ip_push_pending_frames(sk, fl4); 651 } 652 653 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 654 void *user_icmph, size_t icmph_len) 655 { 656 u8 type, code; 657 658 if (len > 0xFFFF) 659 return -EMSGSIZE; 660 661 /* Must have at least a full ICMP header. */ 662 if (len < icmph_len) 663 return -EINVAL; 664 665 /* 666 * Check the flags. 667 */ 668 669 /* Mirror BSD error message compatibility */ 670 if (msg->msg_flags & MSG_OOB) 671 return -EOPNOTSUPP; 672 673 /* 674 * Fetch the ICMP header provided by the userland. 675 * iovec is modified! The ICMP header is consumed. 676 */ 677 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 678 return -EFAULT; 679 680 if (family == AF_INET) { 681 type = ((struct icmphdr *) user_icmph)->type; 682 code = ((struct icmphdr *) user_icmph)->code; 683 #if IS_ENABLED(CONFIG_IPV6) 684 } else if (family == AF_INET6) { 685 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 686 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 687 #endif 688 } else { 689 BUG(); 690 } 691 692 if (!ping_supported(family, type, code)) 693 return -EINVAL; 694 695 return 0; 696 } 697 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 698 699 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 700 { 701 struct net *net = sock_net(sk); 702 struct flowi4 fl4; 703 struct inet_sock *inet = inet_sk(sk); 704 struct ipcm_cookie ipc; 705 struct icmphdr user_icmph; 706 struct pingfakehdr pfh; 707 struct rtable *rt = NULL; 708 struct ip_options_data opt_copy; 709 int free = 0; 710 __be32 saddr, daddr, faddr; 711 u8 tos; 712 int err; 713 714 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 715 716 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 717 sizeof(user_icmph)); 718 if (err) 719 return err; 720 721 /* 722 * Get and verify the address. 723 */ 724 725 if (msg->msg_name) { 726 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 727 if (msg->msg_namelen < sizeof(*usin)) 728 return -EINVAL; 729 if (usin->sin_family != AF_INET) 730 return -EAFNOSUPPORT; 731 daddr = usin->sin_addr.s_addr; 732 /* no remote port */ 733 } else { 734 if (sk->sk_state != TCP_ESTABLISHED) 735 return -EDESTADDRREQ; 736 daddr = inet->inet_daddr; 737 /* no remote port */ 738 } 739 740 ipcm_init_sk(&ipc, inet); 741 742 if (msg->msg_controllen) { 743 err = ip_cmsg_send(sk, msg, &ipc, false); 744 if (unlikely(err)) { 745 kfree(ipc.opt); 746 return err; 747 } 748 if (ipc.opt) 749 free = 1; 750 } 751 if (!ipc.opt) { 752 struct ip_options_rcu *inet_opt; 753 754 rcu_read_lock(); 755 inet_opt = rcu_dereference(inet->inet_opt); 756 if (inet_opt) { 757 memcpy(&opt_copy, inet_opt, 758 sizeof(*inet_opt) + inet_opt->opt.optlen); 759 ipc.opt = &opt_copy.opt; 760 } 761 rcu_read_unlock(); 762 } 763 764 saddr = ipc.addr; 765 ipc.addr = faddr = daddr; 766 767 if (ipc.opt && ipc.opt->opt.srr) { 768 if (!daddr) { 769 err = -EINVAL; 770 goto out_free; 771 } 772 faddr = ipc.opt->opt.faddr; 773 } 774 tos = get_rttos(&ipc, inet); 775 if (sock_flag(sk, SOCK_LOCALROUTE) || 776 (msg->msg_flags & MSG_DONTROUTE) || 777 (ipc.opt && ipc.opt->opt.is_strictroute)) { 778 tos |= RTO_ONLINK; 779 } 780 781 if (ipv4_is_multicast(daddr)) { 782 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 783 ipc.oif = inet->mc_index; 784 if (!saddr) 785 saddr = inet->mc_addr; 786 } else if (!ipc.oif) 787 ipc.oif = inet->uc_index; 788 789 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, 790 RT_SCOPE_UNIVERSE, sk->sk_protocol, 791 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 792 sk->sk_uid); 793 794 fl4.fl4_icmp_type = user_icmph.type; 795 fl4.fl4_icmp_code = user_icmph.code; 796 797 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4)); 798 rt = ip_route_output_flow(net, &fl4, sk); 799 if (IS_ERR(rt)) { 800 err = PTR_ERR(rt); 801 rt = NULL; 802 if (err == -ENETUNREACH) 803 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 804 goto out; 805 } 806 807 err = -EACCES; 808 if ((rt->rt_flags & RTCF_BROADCAST) && 809 !sock_flag(sk, SOCK_BROADCAST)) 810 goto out; 811 812 if (msg->msg_flags & MSG_CONFIRM) 813 goto do_confirm; 814 back_from_confirm: 815 816 if (!ipc.addr) 817 ipc.addr = fl4.daddr; 818 819 lock_sock(sk); 820 821 pfh.icmph.type = user_icmph.type; /* already checked */ 822 pfh.icmph.code = user_icmph.code; /* ditto */ 823 pfh.icmph.checksum = 0; 824 pfh.icmph.un.echo.id = inet->inet_sport; 825 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 826 pfh.msg = msg; 827 pfh.wcheck = 0; 828 pfh.family = AF_INET; 829 830 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 831 0, &ipc, &rt, msg->msg_flags); 832 if (err) 833 ip_flush_pending_frames(sk); 834 else 835 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 836 release_sock(sk); 837 838 out: 839 ip_rt_put(rt); 840 out_free: 841 if (free) 842 kfree(ipc.opt); 843 if (!err) { 844 icmp_out_count(sock_net(sk), user_icmph.type); 845 return len; 846 } 847 return err; 848 849 do_confirm: 850 if (msg->msg_flags & MSG_PROBE) 851 dst_confirm_neigh(&rt->dst, &fl4.daddr); 852 if (!(msg->msg_flags & MSG_PROBE) || len) 853 goto back_from_confirm; 854 err = 0; 855 goto out; 856 } 857 858 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags, 859 int *addr_len) 860 { 861 struct inet_sock *isk = inet_sk(sk); 862 int family = sk->sk_family; 863 struct sk_buff *skb; 864 int copied, err; 865 866 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 867 868 err = -EOPNOTSUPP; 869 if (flags & MSG_OOB) 870 goto out; 871 872 if (flags & MSG_ERRQUEUE) 873 return inet_recv_error(sk, msg, len, addr_len); 874 875 skb = skb_recv_datagram(sk, flags, &err); 876 if (!skb) 877 goto out; 878 879 copied = skb->len; 880 if (copied > len) { 881 msg->msg_flags |= MSG_TRUNC; 882 copied = len; 883 } 884 885 /* Don't bother checking the checksum */ 886 err = skb_copy_datagram_msg(skb, 0, msg, copied); 887 if (err) 888 goto done; 889 890 sock_recv_timestamp(msg, sk, skb); 891 892 /* Copy the address and add cmsg data. */ 893 if (family == AF_INET) { 894 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 895 896 if (sin) { 897 sin->sin_family = AF_INET; 898 sin->sin_port = 0 /* skb->h.uh->source */; 899 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 900 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 901 *addr_len = sizeof(*sin); 902 } 903 904 if (isk->cmsg_flags) 905 ip_cmsg_recv(msg, skb); 906 907 #if IS_ENABLED(CONFIG_IPV6) 908 } else if (family == AF_INET6) { 909 struct ipv6_pinfo *np = inet6_sk(sk); 910 struct ipv6hdr *ip6 = ipv6_hdr(skb); 911 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 912 913 if (sin6) { 914 sin6->sin6_family = AF_INET6; 915 sin6->sin6_port = 0; 916 sin6->sin6_addr = ip6->saddr; 917 sin6->sin6_flowinfo = 0; 918 if (np->sndflow) 919 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 920 sin6->sin6_scope_id = 921 ipv6_iface_scope_id(&sin6->sin6_addr, 922 inet6_iif(skb)); 923 *addr_len = sizeof(*sin6); 924 } 925 926 if (inet6_sk(sk)->rxopt.all) 927 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 928 if (skb->protocol == htons(ETH_P_IPV6) && 929 inet6_sk(sk)->rxopt.all) 930 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 931 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 932 ip_cmsg_recv(msg, skb); 933 #endif 934 } else { 935 BUG(); 936 } 937 938 err = copied; 939 940 done: 941 skb_free_datagram(sk, skb); 942 out: 943 pr_debug("ping_recvmsg -> %d\n", err); 944 return err; 945 } 946 EXPORT_SYMBOL_GPL(ping_recvmsg); 947 948 static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk, 949 struct sk_buff *skb) 950 { 951 enum skb_drop_reason reason; 952 953 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 954 inet_sk(sk), inet_sk(sk)->inet_num, skb); 955 if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) { 956 kfree_skb_reason(skb, reason); 957 pr_debug("ping_queue_rcv_skb -> failed\n"); 958 return reason; 959 } 960 return SKB_NOT_DROPPED_YET; 961 } 962 963 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 964 { 965 return __ping_queue_rcv_skb(sk, skb) ? -1 : 0; 966 } 967 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 968 969 970 /* 971 * All we need to do is get the socket. 972 */ 973 974 enum skb_drop_reason ping_rcv(struct sk_buff *skb) 975 { 976 enum skb_drop_reason reason = SKB_DROP_REASON_NO_SOCKET; 977 struct sock *sk; 978 struct net *net = dev_net(skb->dev); 979 struct icmphdr *icmph = icmp_hdr(skb); 980 981 /* We assume the packet has already been checked by icmp_rcv */ 982 983 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 984 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 985 986 /* Push ICMP header back */ 987 skb_push(skb, skb->data - (u8 *)icmph); 988 989 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 990 if (sk) { 991 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 992 993 pr_debug("rcv on socket %p\n", sk); 994 if (skb2) 995 reason = __ping_queue_rcv_skb(sk, skb2); 996 else 997 reason = SKB_DROP_REASON_NOMEM; 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(RCU) 1084 { 1085 struct ping_iter_state *state = seq->private; 1086 state->bucket = 0; 1087 state->family = family; 1088 1089 rcu_read_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(RCU) 1116 { 1117 rcu_read_unlock(); 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 spin_lock_init(&ping_table.lock); 1202 } 1203