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 pr_err("ping: protocol(%x) is not supported\n", ntohs(skb->protocol)); 191 return NULL; 192 } 193 194 read_lock_bh(&ping_table.lock); 195 196 ping_portaddr_for_each_entry(sk, hnode, hslot) { 197 isk = inet_sk(sk); 198 199 pr_debug("iterate\n"); 200 if (isk->inet_num != ident) 201 continue; 202 203 if (skb->protocol == htons(ETH_P_IP) && 204 sk->sk_family == AF_INET) { 205 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, 206 (int) isk->inet_num, &isk->inet_rcv_saddr, 207 sk->sk_bound_dev_if); 208 209 if (isk->inet_rcv_saddr && 210 isk->inet_rcv_saddr != ip_hdr(skb)->daddr) 211 continue; 212 #if IS_ENABLED(CONFIG_IPV6) 213 } else if (skb->protocol == htons(ETH_P_IPV6) && 214 sk->sk_family == AF_INET6) { 215 216 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, 217 (int) isk->inet_num, 218 &sk->sk_v6_rcv_saddr, 219 sk->sk_bound_dev_if); 220 221 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 222 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, 223 &ipv6_hdr(skb)->daddr)) 224 continue; 225 #endif 226 } else { 227 continue; 228 } 229 230 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif && 231 sk->sk_bound_dev_if != sdif) 232 continue; 233 234 sock_hold(sk); 235 goto exit; 236 } 237 238 sk = NULL; 239 exit: 240 read_unlock_bh(&ping_table.lock); 241 242 return sk; 243 } 244 245 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 246 kgid_t *high) 247 { 248 kgid_t *data = net->ipv4.ping_group_range.range; 249 unsigned int seq; 250 251 do { 252 seq = read_seqbegin(&net->ipv4.ping_group_range.lock); 253 254 *low = data[0]; 255 *high = data[1]; 256 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); 257 } 258 259 260 int ping_init_sock(struct sock *sk) 261 { 262 struct net *net = sock_net(sk); 263 kgid_t group = current_egid(); 264 struct group_info *group_info; 265 int i; 266 kgid_t low, high; 267 int ret = 0; 268 269 if (sk->sk_family == AF_INET6) 270 sk->sk_ipv6only = 1; 271 272 inet_get_ping_group_range_net(net, &low, &high); 273 if (gid_lte(low, group) && gid_lte(group, high)) 274 return 0; 275 276 group_info = get_current_groups(); 277 for (i = 0; i < group_info->ngroups; i++) { 278 kgid_t gid = group_info->gid[i]; 279 280 if (gid_lte(low, gid) && gid_lte(gid, high)) 281 goto out_release_group; 282 } 283 284 ret = -EACCES; 285 286 out_release_group: 287 put_group_info(group_info); 288 return ret; 289 } 290 EXPORT_SYMBOL_GPL(ping_init_sock); 291 292 void ping_close(struct sock *sk, long timeout) 293 { 294 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 295 inet_sk(sk), inet_sk(sk)->inet_num); 296 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt)); 297 298 sk_common_release(sk); 299 } 300 EXPORT_SYMBOL_GPL(ping_close); 301 302 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 303 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 304 struct sockaddr *uaddr, int addr_len) 305 { 306 struct net *net = sock_net(sk); 307 if (sk->sk_family == AF_INET) { 308 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 309 int chk_addr_ret; 310 311 if (addr_len < sizeof(*addr)) 312 return -EINVAL; 313 314 if (addr->sin_family != AF_INET && 315 !(addr->sin_family == AF_UNSPEC && 316 addr->sin_addr.s_addr == htonl(INADDR_ANY))) 317 return -EAFNOSUPPORT; 318 319 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 320 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 321 322 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); 323 324 if (!inet_addr_valid_or_nonlocal(net, inet_sk(sk), 325 addr->sin_addr.s_addr, 326 chk_addr_ret)) 327 return -EADDRNOTAVAIL; 328 329 #if IS_ENABLED(CONFIG_IPV6) 330 } else if (sk->sk_family == AF_INET6) { 331 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 332 int addr_type, scoped, has_addr; 333 struct net_device *dev = NULL; 334 335 if (addr_len < sizeof(*addr)) 336 return -EINVAL; 337 338 if (addr->sin6_family != AF_INET6) 339 return -EAFNOSUPPORT; 340 341 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 342 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 343 344 addr_type = ipv6_addr_type(&addr->sin6_addr); 345 scoped = __ipv6_addr_needs_scope_id(addr_type); 346 if ((addr_type != IPV6_ADDR_ANY && 347 !(addr_type & IPV6_ADDR_UNICAST)) || 348 (scoped && !addr->sin6_scope_id)) 349 return -EINVAL; 350 351 rcu_read_lock(); 352 if (addr->sin6_scope_id) { 353 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 354 if (!dev) { 355 rcu_read_unlock(); 356 return -ENODEV; 357 } 358 } 359 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 360 scoped); 361 rcu_read_unlock(); 362 363 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr || 364 addr_type == IPV6_ADDR_ANY)) 365 return -EADDRNOTAVAIL; 366 367 if (scoped) 368 sk->sk_bound_dev_if = addr->sin6_scope_id; 369 #endif 370 } else { 371 return -EAFNOSUPPORT; 372 } 373 return 0; 374 } 375 376 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 377 { 378 if (saddr->sa_family == AF_INET) { 379 struct inet_sock *isk = inet_sk(sk); 380 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 381 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 382 #if IS_ENABLED(CONFIG_IPV6) 383 } else if (saddr->sa_family == AF_INET6) { 384 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 385 struct ipv6_pinfo *np = inet6_sk(sk); 386 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 387 #endif 388 } 389 } 390 391 /* 392 * We need our own bind because there are no privileged id's == local ports. 393 * Moreover, we don't allow binding to multi- and broadcast addresses. 394 */ 395 396 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 397 { 398 struct inet_sock *isk = inet_sk(sk); 399 unsigned short snum; 400 int err; 401 int dif = sk->sk_bound_dev_if; 402 403 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 404 if (err) 405 return err; 406 407 lock_sock(sk); 408 409 err = -EINVAL; 410 if (isk->inet_num != 0) 411 goto out; 412 413 err = -EADDRINUSE; 414 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 415 if (ping_get_port(sk, snum) != 0) { 416 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */ 417 sk->sk_bound_dev_if = dif; 418 goto out; 419 } 420 ping_set_saddr(sk, uaddr); 421 422 pr_debug("after bind(): num = %hu, dif = %d\n", 423 isk->inet_num, 424 sk->sk_bound_dev_if); 425 426 err = 0; 427 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 428 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 429 #if IS_ENABLED(CONFIG_IPV6) 430 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 431 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 432 #endif 433 434 if (snum) 435 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 436 isk->inet_sport = htons(isk->inet_num); 437 isk->inet_daddr = 0; 438 isk->inet_dport = 0; 439 440 #if IS_ENABLED(CONFIG_IPV6) 441 if (sk->sk_family == AF_INET6) 442 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 443 #endif 444 445 sk_dst_reset(sk); 446 out: 447 release_sock(sk); 448 pr_debug("ping_v4_bind -> %d\n", err); 449 return err; 450 } 451 EXPORT_SYMBOL_GPL(ping_bind); 452 453 /* 454 * Is this a supported type of ICMP message? 455 */ 456 457 static inline int ping_supported(int family, int type, int code) 458 { 459 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 460 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) || 461 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) || 462 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0); 463 } 464 465 /* 466 * This routine is called by the ICMP module when it gets some 467 * sort of error condition. 468 */ 469 470 void ping_err(struct sk_buff *skb, int offset, u32 info) 471 { 472 int family; 473 struct icmphdr *icmph; 474 struct inet_sock *inet_sock; 475 int type; 476 int code; 477 struct net *net = dev_net(skb->dev); 478 struct sock *sk; 479 int harderr; 480 int err; 481 482 if (skb->protocol == htons(ETH_P_IP)) { 483 family = AF_INET; 484 type = icmp_hdr(skb)->type; 485 code = icmp_hdr(skb)->code; 486 icmph = (struct icmphdr *)(skb->data + offset); 487 } else if (skb->protocol == htons(ETH_P_IPV6)) { 488 family = AF_INET6; 489 type = icmp6_hdr(skb)->icmp6_type; 490 code = icmp6_hdr(skb)->icmp6_code; 491 icmph = (struct icmphdr *) (skb->data + offset); 492 } else { 493 BUG(); 494 } 495 496 /* We assume the packet has already been checked by icmp_unreach */ 497 498 if (!ping_supported(family, icmph->type, icmph->code)) 499 return; 500 501 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 502 skb->protocol, type, code, ntohs(icmph->un.echo.id), 503 ntohs(icmph->un.echo.sequence)); 504 505 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 506 if (!sk) { 507 pr_debug("no socket, dropping\n"); 508 return; /* No socket for error */ 509 } 510 pr_debug("err on socket %p\n", sk); 511 512 err = 0; 513 harderr = 0; 514 inet_sock = inet_sk(sk); 515 516 if (skb->protocol == htons(ETH_P_IP)) { 517 switch (type) { 518 default: 519 case ICMP_TIME_EXCEEDED: 520 err = EHOSTUNREACH; 521 break; 522 case ICMP_SOURCE_QUENCH: 523 /* This is not a real error but ping wants to see it. 524 * Report it with some fake errno. 525 */ 526 err = EREMOTEIO; 527 break; 528 case ICMP_PARAMETERPROB: 529 err = EPROTO; 530 harderr = 1; 531 break; 532 case ICMP_DEST_UNREACH: 533 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 534 ipv4_sk_update_pmtu(skb, sk, info); 535 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 536 err = EMSGSIZE; 537 harderr = 1; 538 break; 539 } 540 goto out; 541 } 542 err = EHOSTUNREACH; 543 if (code <= NR_ICMP_UNREACH) { 544 harderr = icmp_err_convert[code].fatal; 545 err = icmp_err_convert[code].errno; 546 } 547 break; 548 case ICMP_REDIRECT: 549 /* See ICMP_SOURCE_QUENCH */ 550 ipv4_sk_redirect(skb, sk); 551 err = EREMOTEIO; 552 break; 553 } 554 #if IS_ENABLED(CONFIG_IPV6) 555 } else if (skb->protocol == htons(ETH_P_IPV6)) { 556 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 557 #endif 558 } 559 560 /* 561 * RFC1122: OK. Passes ICMP errors back to application, as per 562 * 4.1.3.3. 563 */ 564 if ((family == AF_INET && !inet_sock->recverr) || 565 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 566 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 567 goto out; 568 } else { 569 if (family == AF_INET) { 570 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 571 info, (u8 *)icmph); 572 #if IS_ENABLED(CONFIG_IPV6) 573 } else if (family == AF_INET6) { 574 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 575 info, (u8 *)icmph); 576 #endif 577 } 578 } 579 sk->sk_err = err; 580 sk_error_report(sk); 581 out: 582 sock_put(sk); 583 } 584 EXPORT_SYMBOL_GPL(ping_err); 585 586 /* 587 * Copy and checksum an ICMP Echo packet from user space into a buffer 588 * starting from the payload. 589 */ 590 591 int ping_getfrag(void *from, char *to, 592 int offset, int fraglen, int odd, struct sk_buff *skb) 593 { 594 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 595 596 if (offset == 0) { 597 fraglen -= sizeof(struct icmphdr); 598 if (fraglen < 0) 599 BUG(); 600 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), 601 fraglen, &pfh->wcheck, 602 &pfh->msg->msg_iter)) 603 return -EFAULT; 604 } else if (offset < sizeof(struct icmphdr)) { 605 BUG(); 606 } else { 607 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, 608 &pfh->msg->msg_iter)) 609 return -EFAULT; 610 } 611 612 #if IS_ENABLED(CONFIG_IPV6) 613 /* For IPv6, checksum each skb as we go along, as expected by 614 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 615 * wcheck, it will be finalized in ping_v4_push_pending_frames. 616 */ 617 if (pfh->family == AF_INET6) { 618 skb->csum = pfh->wcheck; 619 skb->ip_summed = CHECKSUM_NONE; 620 pfh->wcheck = 0; 621 } 622 #endif 623 624 return 0; 625 } 626 EXPORT_SYMBOL_GPL(ping_getfrag); 627 628 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 629 struct flowi4 *fl4) 630 { 631 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 632 633 if (!skb) 634 return 0; 635 pfh->wcheck = csum_partial((char *)&pfh->icmph, 636 sizeof(struct icmphdr), pfh->wcheck); 637 pfh->icmph.checksum = csum_fold(pfh->wcheck); 638 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 639 skb->ip_summed = CHECKSUM_NONE; 640 return ip_push_pending_frames(sk, fl4); 641 } 642 643 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 644 void *user_icmph, size_t icmph_len) 645 { 646 u8 type, code; 647 648 if (len > 0xFFFF) 649 return -EMSGSIZE; 650 651 /* Must have at least a full ICMP header. */ 652 if (len < icmph_len) 653 return -EINVAL; 654 655 /* 656 * Check the flags. 657 */ 658 659 /* Mirror BSD error message compatibility */ 660 if (msg->msg_flags & MSG_OOB) 661 return -EOPNOTSUPP; 662 663 /* 664 * Fetch the ICMP header provided by the userland. 665 * iovec is modified! The ICMP header is consumed. 666 */ 667 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 668 return -EFAULT; 669 670 if (family == AF_INET) { 671 type = ((struct icmphdr *) user_icmph)->type; 672 code = ((struct icmphdr *) user_icmph)->code; 673 #if IS_ENABLED(CONFIG_IPV6) 674 } else if (family == AF_INET6) { 675 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 676 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 677 #endif 678 } else { 679 BUG(); 680 } 681 682 if (!ping_supported(family, type, code)) 683 return -EINVAL; 684 685 return 0; 686 } 687 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 688 689 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 690 { 691 struct net *net = sock_net(sk); 692 struct flowi4 fl4; 693 struct inet_sock *inet = inet_sk(sk); 694 struct ipcm_cookie ipc; 695 struct icmphdr user_icmph; 696 struct pingfakehdr pfh; 697 struct rtable *rt = NULL; 698 struct ip_options_data opt_copy; 699 int free = 0; 700 __be32 saddr, daddr, faddr; 701 u8 tos; 702 int err; 703 704 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 705 706 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 707 sizeof(user_icmph)); 708 if (err) 709 return err; 710 711 /* 712 * Get and verify the address. 713 */ 714 715 if (msg->msg_name) { 716 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 717 if (msg->msg_namelen < sizeof(*usin)) 718 return -EINVAL; 719 if (usin->sin_family != AF_INET) 720 return -EAFNOSUPPORT; 721 daddr = usin->sin_addr.s_addr; 722 /* no remote port */ 723 } else { 724 if (sk->sk_state != TCP_ESTABLISHED) 725 return -EDESTADDRREQ; 726 daddr = inet->inet_daddr; 727 /* no remote port */ 728 } 729 730 ipcm_init_sk(&ipc, inet); 731 732 if (msg->msg_controllen) { 733 err = ip_cmsg_send(sk, msg, &ipc, false); 734 if (unlikely(err)) { 735 kfree(ipc.opt); 736 return err; 737 } 738 if (ipc.opt) 739 free = 1; 740 } 741 if (!ipc.opt) { 742 struct ip_options_rcu *inet_opt; 743 744 rcu_read_lock(); 745 inet_opt = rcu_dereference(inet->inet_opt); 746 if (inet_opt) { 747 memcpy(&opt_copy, inet_opt, 748 sizeof(*inet_opt) + inet_opt->opt.optlen); 749 ipc.opt = &opt_copy.opt; 750 } 751 rcu_read_unlock(); 752 } 753 754 saddr = ipc.addr; 755 ipc.addr = faddr = daddr; 756 757 if (ipc.opt && ipc.opt->opt.srr) { 758 if (!daddr) { 759 err = -EINVAL; 760 goto out_free; 761 } 762 faddr = ipc.opt->opt.faddr; 763 } 764 tos = get_rttos(&ipc, inet); 765 if (sock_flag(sk, SOCK_LOCALROUTE) || 766 (msg->msg_flags & MSG_DONTROUTE) || 767 (ipc.opt && ipc.opt->opt.is_strictroute)) { 768 tos |= RTO_ONLINK; 769 } 770 771 if (ipv4_is_multicast(daddr)) { 772 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 773 ipc.oif = inet->mc_index; 774 if (!saddr) 775 saddr = inet->mc_addr; 776 } else if (!ipc.oif) 777 ipc.oif = inet->uc_index; 778 779 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, 780 RT_SCOPE_UNIVERSE, sk->sk_protocol, 781 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 782 sk->sk_uid); 783 784 fl4.fl4_icmp_type = user_icmph.type; 785 fl4.fl4_icmp_code = user_icmph.code; 786 787 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4)); 788 rt = ip_route_output_flow(net, &fl4, sk); 789 if (IS_ERR(rt)) { 790 err = PTR_ERR(rt); 791 rt = NULL; 792 if (err == -ENETUNREACH) 793 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 794 goto out; 795 } 796 797 err = -EACCES; 798 if ((rt->rt_flags & RTCF_BROADCAST) && 799 !sock_flag(sk, SOCK_BROADCAST)) 800 goto out; 801 802 if (msg->msg_flags & MSG_CONFIRM) 803 goto do_confirm; 804 back_from_confirm: 805 806 if (!ipc.addr) 807 ipc.addr = fl4.daddr; 808 809 lock_sock(sk); 810 811 pfh.icmph.type = user_icmph.type; /* already checked */ 812 pfh.icmph.code = user_icmph.code; /* ditto */ 813 pfh.icmph.checksum = 0; 814 pfh.icmph.un.echo.id = inet->inet_sport; 815 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 816 pfh.msg = msg; 817 pfh.wcheck = 0; 818 pfh.family = AF_INET; 819 820 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 821 0, &ipc, &rt, msg->msg_flags); 822 if (err) 823 ip_flush_pending_frames(sk); 824 else 825 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 826 release_sock(sk); 827 828 out: 829 ip_rt_put(rt); 830 out_free: 831 if (free) 832 kfree(ipc.opt); 833 if (!err) { 834 icmp_out_count(sock_net(sk), user_icmph.type); 835 return len; 836 } 837 return err; 838 839 do_confirm: 840 if (msg->msg_flags & MSG_PROBE) 841 dst_confirm_neigh(&rt->dst, &fl4.daddr); 842 if (!(msg->msg_flags & MSG_PROBE) || len) 843 goto back_from_confirm; 844 err = 0; 845 goto out; 846 } 847 848 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 849 int flags, int *addr_len) 850 { 851 struct inet_sock *isk = inet_sk(sk); 852 int family = sk->sk_family; 853 struct sk_buff *skb; 854 int copied, err; 855 856 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 857 858 err = -EOPNOTSUPP; 859 if (flags & MSG_OOB) 860 goto out; 861 862 if (flags & MSG_ERRQUEUE) 863 return inet_recv_error(sk, msg, len, addr_len); 864 865 skb = skb_recv_datagram(sk, flags, noblock, &err); 866 if (!skb) 867 goto out; 868 869 copied = skb->len; 870 if (copied > len) { 871 msg->msg_flags |= MSG_TRUNC; 872 copied = len; 873 } 874 875 /* Don't bother checking the checksum */ 876 err = skb_copy_datagram_msg(skb, 0, msg, copied); 877 if (err) 878 goto done; 879 880 sock_recv_timestamp(msg, sk, skb); 881 882 /* Copy the address and add cmsg data. */ 883 if (family == AF_INET) { 884 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 885 886 if (sin) { 887 sin->sin_family = AF_INET; 888 sin->sin_port = 0 /* skb->h.uh->source */; 889 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 890 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 891 *addr_len = sizeof(*sin); 892 } 893 894 if (isk->cmsg_flags) 895 ip_cmsg_recv(msg, skb); 896 897 #if IS_ENABLED(CONFIG_IPV6) 898 } else if (family == AF_INET6) { 899 struct ipv6_pinfo *np = inet6_sk(sk); 900 struct ipv6hdr *ip6 = ipv6_hdr(skb); 901 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 902 903 if (sin6) { 904 sin6->sin6_family = AF_INET6; 905 sin6->sin6_port = 0; 906 sin6->sin6_addr = ip6->saddr; 907 sin6->sin6_flowinfo = 0; 908 if (np->sndflow) 909 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 910 sin6->sin6_scope_id = 911 ipv6_iface_scope_id(&sin6->sin6_addr, 912 inet6_iif(skb)); 913 *addr_len = sizeof(*sin6); 914 } 915 916 if (inet6_sk(sk)->rxopt.all) 917 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 918 if (skb->protocol == htons(ETH_P_IPV6) && 919 inet6_sk(sk)->rxopt.all) 920 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 921 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 922 ip_cmsg_recv(msg, skb); 923 #endif 924 } else { 925 BUG(); 926 } 927 928 err = copied; 929 930 done: 931 skb_free_datagram(sk, skb); 932 out: 933 pr_debug("ping_recvmsg -> %d\n", err); 934 return err; 935 } 936 EXPORT_SYMBOL_GPL(ping_recvmsg); 937 938 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 939 { 940 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 941 inet_sk(sk), inet_sk(sk)->inet_num, skb); 942 if (sock_queue_rcv_skb(sk, skb) < 0) { 943 kfree_skb(skb); 944 pr_debug("ping_queue_rcv_skb -> failed\n"); 945 return -1; 946 } 947 return 0; 948 } 949 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 950 951 952 /* 953 * All we need to do is get the socket. 954 */ 955 956 bool ping_rcv(struct sk_buff *skb) 957 { 958 struct sock *sk; 959 struct net *net = dev_net(skb->dev); 960 struct icmphdr *icmph = icmp_hdr(skb); 961 bool rc = false; 962 963 /* We assume the packet has already been checked by icmp_rcv */ 964 965 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 966 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 967 968 /* Push ICMP header back */ 969 skb_push(skb, skb->data - (u8 *)icmph); 970 971 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 972 if (sk) { 973 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 974 975 pr_debug("rcv on socket %p\n", sk); 976 if (skb2 && !ping_queue_rcv_skb(sk, skb2)) 977 rc = true; 978 sock_put(sk); 979 } 980 981 if (!rc) 982 pr_debug("no socket, dropping\n"); 983 984 return rc; 985 } 986 EXPORT_SYMBOL_GPL(ping_rcv); 987 988 struct proto ping_prot = { 989 .name = "PING", 990 .owner = THIS_MODULE, 991 .init = ping_init_sock, 992 .close = ping_close, 993 .connect = ip4_datagram_connect, 994 .disconnect = __udp_disconnect, 995 .setsockopt = ip_setsockopt, 996 .getsockopt = ip_getsockopt, 997 .sendmsg = ping_v4_sendmsg, 998 .recvmsg = ping_recvmsg, 999 .bind = ping_bind, 1000 .backlog_rcv = ping_queue_rcv_skb, 1001 .release_cb = ip4_datagram_release_cb, 1002 .hash = ping_hash, 1003 .unhash = ping_unhash, 1004 .get_port = ping_get_port, 1005 .put_port = ping_unhash, 1006 .obj_size = sizeof(struct inet_sock), 1007 }; 1008 EXPORT_SYMBOL(ping_prot); 1009 1010 #ifdef CONFIG_PROC_FS 1011 1012 static struct sock *ping_get_first(struct seq_file *seq, int start) 1013 { 1014 struct sock *sk; 1015 struct ping_iter_state *state = seq->private; 1016 struct net *net = seq_file_net(seq); 1017 1018 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1019 ++state->bucket) { 1020 struct hlist_nulls_node *node; 1021 struct hlist_nulls_head *hslot; 1022 1023 hslot = &ping_table.hash[state->bucket]; 1024 1025 if (hlist_nulls_empty(hslot)) 1026 continue; 1027 1028 sk_nulls_for_each(sk, node, hslot) { 1029 if (net_eq(sock_net(sk), net) && 1030 sk->sk_family == state->family) 1031 goto found; 1032 } 1033 } 1034 sk = NULL; 1035 found: 1036 return sk; 1037 } 1038 1039 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1040 { 1041 struct ping_iter_state *state = seq->private; 1042 struct net *net = seq_file_net(seq); 1043 1044 do { 1045 sk = sk_nulls_next(sk); 1046 } while (sk && (!net_eq(sock_net(sk), net))); 1047 1048 if (!sk) 1049 return ping_get_first(seq, state->bucket + 1); 1050 return sk; 1051 } 1052 1053 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1054 { 1055 struct sock *sk = ping_get_first(seq, 0); 1056 1057 if (sk) 1058 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1059 --pos; 1060 return pos ? NULL : sk; 1061 } 1062 1063 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1064 __acquires(ping_table.lock) 1065 { 1066 struct ping_iter_state *state = seq->private; 1067 state->bucket = 0; 1068 state->family = family; 1069 1070 read_lock_bh(&ping_table.lock); 1071 1072 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1073 } 1074 EXPORT_SYMBOL_GPL(ping_seq_start); 1075 1076 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1077 { 1078 return ping_seq_start(seq, pos, AF_INET); 1079 } 1080 1081 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1082 { 1083 struct sock *sk; 1084 1085 if (v == SEQ_START_TOKEN) 1086 sk = ping_get_idx(seq, 0); 1087 else 1088 sk = ping_get_next(seq, v); 1089 1090 ++*pos; 1091 return sk; 1092 } 1093 EXPORT_SYMBOL_GPL(ping_seq_next); 1094 1095 void ping_seq_stop(struct seq_file *seq, void *v) 1096 __releases(ping_table.lock) 1097 { 1098 read_unlock_bh(&ping_table.lock); 1099 } 1100 EXPORT_SYMBOL_GPL(ping_seq_stop); 1101 1102 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1103 int bucket) 1104 { 1105 struct inet_sock *inet = inet_sk(sp); 1106 __be32 dest = inet->inet_daddr; 1107 __be32 src = inet->inet_rcv_saddr; 1108 __u16 destp = ntohs(inet->inet_dport); 1109 __u16 srcp = ntohs(inet->inet_sport); 1110 1111 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1112 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", 1113 bucket, src, srcp, dest, destp, sp->sk_state, 1114 sk_wmem_alloc_get(sp), 1115 sk_rmem_alloc_get(sp), 1116 0, 0L, 0, 1117 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1118 0, sock_i_ino(sp), 1119 refcount_read(&sp->sk_refcnt), sp, 1120 atomic_read(&sp->sk_drops)); 1121 } 1122 1123 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1124 { 1125 seq_setwidth(seq, 127); 1126 if (v == SEQ_START_TOKEN) 1127 seq_puts(seq, " sl local_address rem_address st tx_queue " 1128 "rx_queue tr tm->when retrnsmt uid timeout " 1129 "inode ref pointer drops"); 1130 else { 1131 struct ping_iter_state *state = seq->private; 1132 1133 ping_v4_format_sock(v, seq, state->bucket); 1134 } 1135 seq_pad(seq, '\n'); 1136 return 0; 1137 } 1138 1139 static const struct seq_operations ping_v4_seq_ops = { 1140 .start = ping_v4_seq_start, 1141 .show = ping_v4_seq_show, 1142 .next = ping_seq_next, 1143 .stop = ping_seq_stop, 1144 }; 1145 1146 static int __net_init ping_v4_proc_init_net(struct net *net) 1147 { 1148 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops, 1149 sizeof(struct ping_iter_state))) 1150 return -ENOMEM; 1151 return 0; 1152 } 1153 1154 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1155 { 1156 remove_proc_entry("icmp", net->proc_net); 1157 } 1158 1159 static struct pernet_operations ping_v4_net_ops = { 1160 .init = ping_v4_proc_init_net, 1161 .exit = ping_v4_proc_exit_net, 1162 }; 1163 1164 int __init ping_proc_init(void) 1165 { 1166 return register_pernet_subsys(&ping_v4_net_ops); 1167 } 1168 1169 void ping_proc_exit(void) 1170 { 1171 unregister_pernet_subsys(&ping_v4_net_ops); 1172 } 1173 1174 #endif 1175 1176 void __init ping_init(void) 1177 { 1178 int i; 1179 1180 for (i = 0; i < PING_HTABLE_SIZE; i++) 1181 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1182 rwlock_init(&ping_table.lock); 1183 } 1184