1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * "Ping" sockets 8 * 9 * Based on ipv4/udp.c code. 10 * 11 * Authors: Vasiliy Kulikov / Openwall (for Linux 2.6), 12 * Pavel Kankovsky (for Linux 2.4.32) 13 * 14 * Pavel gave all rights to bugs to Vasiliy, 15 * none of the bugs are Pavel's now. 16 */ 17 18 #include <linux/uaccess.h> 19 #include <linux/types.h> 20 #include <linux/fcntl.h> 21 #include <linux/socket.h> 22 #include <linux/sockios.h> 23 #include <linux/in.h> 24 #include <linux/errno.h> 25 #include <linux/timer.h> 26 #include <linux/mm.h> 27 #include <linux/inet.h> 28 #include <linux/netdevice.h> 29 #include <net/snmp.h> 30 #include <net/ip.h> 31 #include <net/icmp.h> 32 #include <net/protocol.h> 33 #include <linux/skbuff.h> 34 #include <linux/proc_fs.h> 35 #include <linux/export.h> 36 #include <net/sock.h> 37 #include <net/ping.h> 38 #include <net/udp.h> 39 #include <net/route.h> 40 #include <net/inet_common.h> 41 #include <net/checksum.h> 42 43 #if IS_ENABLED(CONFIG_IPV6) 44 #include <linux/in6.h> 45 #include <linux/icmpv6.h> 46 #include <net/addrconf.h> 47 #include <net/ipv6.h> 48 #include <net/transp_v6.h> 49 #endif 50 51 struct ping_table { 52 struct hlist_nulls_head hash[PING_HTABLE_SIZE]; 53 rwlock_t lock; 54 }; 55 56 static struct ping_table ping_table; 57 struct pingv6_ops pingv6_ops; 58 EXPORT_SYMBOL_GPL(pingv6_ops); 59 60 static u16 ping_port_rover; 61 62 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask) 63 { 64 u32 res = (num + net_hash_mix(net)) & mask; 65 66 pr_debug("hash(%u) = %u\n", num, res); 67 return res; 68 } 69 EXPORT_SYMBOL_GPL(ping_hash); 70 71 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table, 72 struct net *net, unsigned int num) 73 { 74 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)]; 75 } 76 77 int ping_get_port(struct sock *sk, unsigned short ident) 78 { 79 struct hlist_nulls_node *node; 80 struct hlist_nulls_head *hlist; 81 struct inet_sock *isk, *isk2; 82 struct sock *sk2 = NULL; 83 84 isk = inet_sk(sk); 85 write_lock_bh(&ping_table.lock); 86 if (ident == 0) { 87 u32 i; 88 u16 result = ping_port_rover + 1; 89 90 for (i = 0; i < (1L << 16); i++, result++) { 91 if (!result) 92 result++; /* avoid zero */ 93 hlist = ping_hashslot(&ping_table, sock_net(sk), 94 result); 95 ping_portaddr_for_each_entry(sk2, node, hlist) { 96 isk2 = inet_sk(sk2); 97 98 if (isk2->inet_num == result) 99 goto next_port; 100 } 101 102 /* found */ 103 ping_port_rover = ident = result; 104 break; 105 next_port: 106 ; 107 } 108 if (i >= (1L << 16)) 109 goto fail; 110 } else { 111 hlist = ping_hashslot(&ping_table, sock_net(sk), ident); 112 ping_portaddr_for_each_entry(sk2, node, hlist) { 113 isk2 = inet_sk(sk2); 114 115 /* BUG? Why is this reuse and not reuseaddr? ping.c 116 * doesn't turn off SO_REUSEADDR, and it doesn't expect 117 * that other ping processes can steal its packets. 118 */ 119 if ((isk2->inet_num == ident) && 120 (sk2 != sk) && 121 (!sk2->sk_reuse || !sk->sk_reuse)) 122 goto fail; 123 } 124 } 125 126 pr_debug("found port/ident = %d\n", ident); 127 isk->inet_num = ident; 128 if (sk_unhashed(sk)) { 129 pr_debug("was not hashed\n"); 130 sock_hold(sk); 131 hlist_nulls_add_head(&sk->sk_nulls_node, hlist); 132 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 133 } 134 write_unlock_bh(&ping_table.lock); 135 return 0; 136 137 fail: 138 write_unlock_bh(&ping_table.lock); 139 return 1; 140 } 141 EXPORT_SYMBOL_GPL(ping_get_port); 142 143 int ping_hash(struct sock *sk) 144 { 145 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num); 146 BUG(); /* "Please do not press this button again." */ 147 148 return 0; 149 } 150 151 void ping_unhash(struct sock *sk) 152 { 153 struct inet_sock *isk = inet_sk(sk); 154 155 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); 156 write_lock_bh(&ping_table.lock); 157 if (sk_hashed(sk)) { 158 hlist_nulls_del(&sk->sk_nulls_node); 159 sk_nulls_node_init(&sk->sk_nulls_node); 160 sock_put(sk); 161 isk->inet_num = 0; 162 isk->inet_sport = 0; 163 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 164 } 165 write_unlock_bh(&ping_table.lock); 166 } 167 EXPORT_SYMBOL_GPL(ping_unhash); 168 169 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) 170 { 171 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); 172 struct sock *sk = NULL; 173 struct inet_sock *isk; 174 struct hlist_nulls_node *hnode; 175 int dif, sdif; 176 177 if (skb->protocol == htons(ETH_P_IP)) { 178 dif = inet_iif(skb); 179 sdif = inet_sdif(skb); 180 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n", 181 (int)ident, &ip_hdr(skb)->daddr, dif); 182 #if IS_ENABLED(CONFIG_IPV6) 183 } else if (skb->protocol == htons(ETH_P_IPV6)) { 184 dif = inet6_iif(skb); 185 sdif = inet6_sdif(skb); 186 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", 187 (int)ident, &ipv6_hdr(skb)->daddr, dif); 188 #endif 189 } else { 190 return NULL; 191 } 192 193 read_lock_bh(&ping_table.lock); 194 195 ping_portaddr_for_each_entry(sk, hnode, hslot) { 196 isk = inet_sk(sk); 197 198 pr_debug("iterate\n"); 199 if (isk->inet_num != ident) 200 continue; 201 202 if (skb->protocol == htons(ETH_P_IP) && 203 sk->sk_family == AF_INET) { 204 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, 205 (int) isk->inet_num, &isk->inet_rcv_saddr, 206 sk->sk_bound_dev_if); 207 208 if (isk->inet_rcv_saddr && 209 isk->inet_rcv_saddr != ip_hdr(skb)->daddr) 210 continue; 211 #if IS_ENABLED(CONFIG_IPV6) 212 } else if (skb->protocol == htons(ETH_P_IPV6) && 213 sk->sk_family == AF_INET6) { 214 215 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, 216 (int) isk->inet_num, 217 &sk->sk_v6_rcv_saddr, 218 sk->sk_bound_dev_if); 219 220 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 221 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, 222 &ipv6_hdr(skb)->daddr)) 223 continue; 224 #endif 225 } else { 226 continue; 227 } 228 229 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif && 230 sk->sk_bound_dev_if != sdif) 231 continue; 232 233 sock_hold(sk); 234 goto exit; 235 } 236 237 sk = NULL; 238 exit: 239 read_unlock_bh(&ping_table.lock); 240 241 return sk; 242 } 243 244 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 245 kgid_t *high) 246 { 247 kgid_t *data = net->ipv4.ping_group_range.range; 248 unsigned int seq; 249 250 do { 251 seq = read_seqbegin(&net->ipv4.ping_group_range.lock); 252 253 *low = data[0]; 254 *high = data[1]; 255 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); 256 } 257 258 259 int ping_init_sock(struct sock *sk) 260 { 261 struct net *net = sock_net(sk); 262 kgid_t group = current_egid(); 263 struct group_info *group_info; 264 int i; 265 kgid_t low, high; 266 int ret = 0; 267 268 if (sk->sk_family == AF_INET6) 269 sk->sk_ipv6only = 1; 270 271 inet_get_ping_group_range_net(net, &low, &high); 272 if (gid_lte(low, group) && gid_lte(group, high)) 273 return 0; 274 275 group_info = get_current_groups(); 276 for (i = 0; i < group_info->ngroups; i++) { 277 kgid_t gid = group_info->gid[i]; 278 279 if (gid_lte(low, gid) && gid_lte(gid, high)) 280 goto out_release_group; 281 } 282 283 ret = -EACCES; 284 285 out_release_group: 286 put_group_info(group_info); 287 return ret; 288 } 289 EXPORT_SYMBOL_GPL(ping_init_sock); 290 291 void ping_close(struct sock *sk, long timeout) 292 { 293 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 294 inet_sk(sk), inet_sk(sk)->inet_num); 295 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt)); 296 297 sk_common_release(sk); 298 } 299 EXPORT_SYMBOL_GPL(ping_close); 300 301 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 302 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 303 struct sockaddr *uaddr, int addr_len) 304 { 305 struct net *net = sock_net(sk); 306 if (sk->sk_family == AF_INET) { 307 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 308 int chk_addr_ret; 309 310 if (addr_len < sizeof(*addr)) 311 return -EINVAL; 312 313 if (addr->sin_family != AF_INET && 314 !(addr->sin_family == AF_UNSPEC && 315 addr->sin_addr.s_addr == htonl(INADDR_ANY))) 316 return -EAFNOSUPPORT; 317 318 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 319 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 320 321 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); 322 323 if (!inet_addr_valid_or_nonlocal(net, inet_sk(sk), 324 addr->sin_addr.s_addr, 325 chk_addr_ret)) 326 return -EADDRNOTAVAIL; 327 328 #if IS_ENABLED(CONFIG_IPV6) 329 } else if (sk->sk_family == AF_INET6) { 330 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 331 int addr_type, scoped, has_addr; 332 struct net_device *dev = NULL; 333 334 if (addr_len < sizeof(*addr)) 335 return -EINVAL; 336 337 if (addr->sin6_family != AF_INET6) 338 return -EAFNOSUPPORT; 339 340 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 341 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 342 343 addr_type = ipv6_addr_type(&addr->sin6_addr); 344 scoped = __ipv6_addr_needs_scope_id(addr_type); 345 if ((addr_type != IPV6_ADDR_ANY && 346 !(addr_type & IPV6_ADDR_UNICAST)) || 347 (scoped && !addr->sin6_scope_id)) 348 return -EINVAL; 349 350 rcu_read_lock(); 351 if (addr->sin6_scope_id) { 352 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 353 if (!dev) { 354 rcu_read_unlock(); 355 return -ENODEV; 356 } 357 } 358 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 359 scoped); 360 rcu_read_unlock(); 361 362 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr || 363 addr_type == IPV6_ADDR_ANY)) 364 return -EADDRNOTAVAIL; 365 366 if (scoped) 367 sk->sk_bound_dev_if = addr->sin6_scope_id; 368 #endif 369 } else { 370 return -EAFNOSUPPORT; 371 } 372 return 0; 373 } 374 375 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 376 { 377 if (saddr->sa_family == AF_INET) { 378 struct inet_sock *isk = inet_sk(sk); 379 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 380 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 381 #if IS_ENABLED(CONFIG_IPV6) 382 } else if (saddr->sa_family == AF_INET6) { 383 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 384 struct ipv6_pinfo *np = inet6_sk(sk); 385 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 386 #endif 387 } 388 } 389 390 /* 391 * We need our own bind because there are no privileged id's == local ports. 392 * Moreover, we don't allow binding to multi- and broadcast addresses. 393 */ 394 395 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 396 { 397 struct inet_sock *isk = inet_sk(sk); 398 unsigned short snum; 399 int err; 400 int dif = sk->sk_bound_dev_if; 401 402 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 403 if (err) 404 return err; 405 406 lock_sock(sk); 407 408 err = -EINVAL; 409 if (isk->inet_num != 0) 410 goto out; 411 412 err = -EADDRINUSE; 413 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 414 if (ping_get_port(sk, snum) != 0) { 415 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */ 416 sk->sk_bound_dev_if = dif; 417 goto out; 418 } 419 ping_set_saddr(sk, uaddr); 420 421 pr_debug("after bind(): num = %hu, dif = %d\n", 422 isk->inet_num, 423 sk->sk_bound_dev_if); 424 425 err = 0; 426 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 427 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 428 #if IS_ENABLED(CONFIG_IPV6) 429 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 430 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 431 #endif 432 433 if (snum) 434 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 435 isk->inet_sport = htons(isk->inet_num); 436 isk->inet_daddr = 0; 437 isk->inet_dport = 0; 438 439 #if IS_ENABLED(CONFIG_IPV6) 440 if (sk->sk_family == AF_INET6) 441 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 442 #endif 443 444 sk_dst_reset(sk); 445 out: 446 release_sock(sk); 447 pr_debug("ping_v4_bind -> %d\n", err); 448 return err; 449 } 450 EXPORT_SYMBOL_GPL(ping_bind); 451 452 /* 453 * Is this a supported type of ICMP message? 454 */ 455 456 static inline int ping_supported(int family, int type, int code) 457 { 458 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 459 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) || 460 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) || 461 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0); 462 } 463 464 /* 465 * This routine is called by the ICMP module when it gets some 466 * sort of error condition. 467 */ 468 469 void ping_err(struct sk_buff *skb, int offset, u32 info) 470 { 471 int family; 472 struct icmphdr *icmph; 473 struct inet_sock *inet_sock; 474 int type; 475 int code; 476 struct net *net = dev_net(skb->dev); 477 struct sock *sk; 478 int harderr; 479 int err; 480 481 if (skb->protocol == htons(ETH_P_IP)) { 482 family = AF_INET; 483 type = icmp_hdr(skb)->type; 484 code = icmp_hdr(skb)->code; 485 icmph = (struct icmphdr *)(skb->data + offset); 486 } else if (skb->protocol == htons(ETH_P_IPV6)) { 487 family = AF_INET6; 488 type = icmp6_hdr(skb)->icmp6_type; 489 code = icmp6_hdr(skb)->icmp6_code; 490 icmph = (struct icmphdr *) (skb->data + offset); 491 } else { 492 BUG(); 493 } 494 495 /* We assume the packet has already been checked by icmp_unreach */ 496 497 if (!ping_supported(family, icmph->type, icmph->code)) 498 return; 499 500 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 501 skb->protocol, type, code, ntohs(icmph->un.echo.id), 502 ntohs(icmph->un.echo.sequence)); 503 504 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 505 if (!sk) { 506 pr_debug("no socket, dropping\n"); 507 return; /* No socket for error */ 508 } 509 pr_debug("err on socket %p\n", sk); 510 511 err = 0; 512 harderr = 0; 513 inet_sock = inet_sk(sk); 514 515 if (skb->protocol == htons(ETH_P_IP)) { 516 switch (type) { 517 default: 518 case ICMP_TIME_EXCEEDED: 519 err = EHOSTUNREACH; 520 break; 521 case ICMP_SOURCE_QUENCH: 522 /* This is not a real error but ping wants to see it. 523 * Report it with some fake errno. 524 */ 525 err = EREMOTEIO; 526 break; 527 case ICMP_PARAMETERPROB: 528 err = EPROTO; 529 harderr = 1; 530 break; 531 case ICMP_DEST_UNREACH: 532 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 533 ipv4_sk_update_pmtu(skb, sk, info); 534 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 535 err = EMSGSIZE; 536 harderr = 1; 537 break; 538 } 539 goto out; 540 } 541 err = EHOSTUNREACH; 542 if (code <= NR_ICMP_UNREACH) { 543 harderr = icmp_err_convert[code].fatal; 544 err = icmp_err_convert[code].errno; 545 } 546 break; 547 case ICMP_REDIRECT: 548 /* See ICMP_SOURCE_QUENCH */ 549 ipv4_sk_redirect(skb, sk); 550 err = EREMOTEIO; 551 break; 552 } 553 #if IS_ENABLED(CONFIG_IPV6) 554 } else if (skb->protocol == htons(ETH_P_IPV6)) { 555 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 556 #endif 557 } 558 559 /* 560 * RFC1122: OK. Passes ICMP errors back to application, as per 561 * 4.1.3.3. 562 */ 563 if ((family == AF_INET && !inet_sock->recverr) || 564 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 565 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 566 goto out; 567 } else { 568 if (family == AF_INET) { 569 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 570 info, (u8 *)icmph); 571 #if IS_ENABLED(CONFIG_IPV6) 572 } else if (family == AF_INET6) { 573 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 574 info, (u8 *)icmph); 575 #endif 576 } 577 } 578 sk->sk_err = err; 579 sk_error_report(sk); 580 out: 581 sock_put(sk); 582 } 583 EXPORT_SYMBOL_GPL(ping_err); 584 585 /* 586 * Copy and checksum an ICMP Echo packet from user space into a buffer 587 * starting from the payload. 588 */ 589 590 int ping_getfrag(void *from, char *to, 591 int offset, int fraglen, int odd, struct sk_buff *skb) 592 { 593 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 594 595 if (offset == 0) { 596 fraglen -= sizeof(struct icmphdr); 597 if (fraglen < 0) 598 BUG(); 599 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), 600 fraglen, &pfh->wcheck, 601 &pfh->msg->msg_iter)) 602 return -EFAULT; 603 } else if (offset < sizeof(struct icmphdr)) { 604 BUG(); 605 } else { 606 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, 607 &pfh->msg->msg_iter)) 608 return -EFAULT; 609 } 610 611 #if IS_ENABLED(CONFIG_IPV6) 612 /* For IPv6, checksum each skb as we go along, as expected by 613 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 614 * wcheck, it will be finalized in ping_v4_push_pending_frames. 615 */ 616 if (pfh->family == AF_INET6) { 617 skb->csum = pfh->wcheck; 618 skb->ip_summed = CHECKSUM_NONE; 619 pfh->wcheck = 0; 620 } 621 #endif 622 623 return 0; 624 } 625 EXPORT_SYMBOL_GPL(ping_getfrag); 626 627 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 628 struct flowi4 *fl4) 629 { 630 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 631 632 if (!skb) 633 return 0; 634 pfh->wcheck = csum_partial((char *)&pfh->icmph, 635 sizeof(struct icmphdr), pfh->wcheck); 636 pfh->icmph.checksum = csum_fold(pfh->wcheck); 637 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 638 skb->ip_summed = CHECKSUM_NONE; 639 return ip_push_pending_frames(sk, fl4); 640 } 641 642 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 643 void *user_icmph, size_t icmph_len) 644 { 645 u8 type, code; 646 647 if (len > 0xFFFF) 648 return -EMSGSIZE; 649 650 /* Must have at least a full ICMP header. */ 651 if (len < icmph_len) 652 return -EINVAL; 653 654 /* 655 * Check the flags. 656 */ 657 658 /* Mirror BSD error message compatibility */ 659 if (msg->msg_flags & MSG_OOB) 660 return -EOPNOTSUPP; 661 662 /* 663 * Fetch the ICMP header provided by the userland. 664 * iovec is modified! The ICMP header is consumed. 665 */ 666 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 667 return -EFAULT; 668 669 if (family == AF_INET) { 670 type = ((struct icmphdr *) user_icmph)->type; 671 code = ((struct icmphdr *) user_icmph)->code; 672 #if IS_ENABLED(CONFIG_IPV6) 673 } else if (family == AF_INET6) { 674 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 675 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 676 #endif 677 } else { 678 BUG(); 679 } 680 681 if (!ping_supported(family, type, code)) 682 return -EINVAL; 683 684 return 0; 685 } 686 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 687 688 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 689 { 690 struct net *net = sock_net(sk); 691 struct flowi4 fl4; 692 struct inet_sock *inet = inet_sk(sk); 693 struct ipcm_cookie ipc; 694 struct icmphdr user_icmph; 695 struct pingfakehdr pfh; 696 struct rtable *rt = NULL; 697 struct ip_options_data opt_copy; 698 int free = 0; 699 __be32 saddr, daddr, faddr; 700 u8 tos; 701 int err; 702 703 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 704 705 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 706 sizeof(user_icmph)); 707 if (err) 708 return err; 709 710 /* 711 * Get and verify the address. 712 */ 713 714 if (msg->msg_name) { 715 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 716 if (msg->msg_namelen < sizeof(*usin)) 717 return -EINVAL; 718 if (usin->sin_family != AF_INET) 719 return -EAFNOSUPPORT; 720 daddr = usin->sin_addr.s_addr; 721 /* no remote port */ 722 } else { 723 if (sk->sk_state != TCP_ESTABLISHED) 724 return -EDESTADDRREQ; 725 daddr = inet->inet_daddr; 726 /* no remote port */ 727 } 728 729 ipcm_init_sk(&ipc, inet); 730 731 if (msg->msg_controllen) { 732 err = ip_cmsg_send(sk, msg, &ipc, false); 733 if (unlikely(err)) { 734 kfree(ipc.opt); 735 return err; 736 } 737 if (ipc.opt) 738 free = 1; 739 } 740 if (!ipc.opt) { 741 struct ip_options_rcu *inet_opt; 742 743 rcu_read_lock(); 744 inet_opt = rcu_dereference(inet->inet_opt); 745 if (inet_opt) { 746 memcpy(&opt_copy, inet_opt, 747 sizeof(*inet_opt) + inet_opt->opt.optlen); 748 ipc.opt = &opt_copy.opt; 749 } 750 rcu_read_unlock(); 751 } 752 753 saddr = ipc.addr; 754 ipc.addr = faddr = daddr; 755 756 if (ipc.opt && ipc.opt->opt.srr) { 757 if (!daddr) { 758 err = -EINVAL; 759 goto out_free; 760 } 761 faddr = ipc.opt->opt.faddr; 762 } 763 tos = get_rttos(&ipc, inet); 764 if (sock_flag(sk, SOCK_LOCALROUTE) || 765 (msg->msg_flags & MSG_DONTROUTE) || 766 (ipc.opt && ipc.opt->opt.is_strictroute)) { 767 tos |= RTO_ONLINK; 768 } 769 770 if (ipv4_is_multicast(daddr)) { 771 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 772 ipc.oif = inet->mc_index; 773 if (!saddr) 774 saddr = inet->mc_addr; 775 } else if (!ipc.oif) 776 ipc.oif = inet->uc_index; 777 778 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, 779 RT_SCOPE_UNIVERSE, sk->sk_protocol, 780 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 781 sk->sk_uid); 782 783 fl4.fl4_icmp_type = user_icmph.type; 784 fl4.fl4_icmp_code = user_icmph.code; 785 786 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4)); 787 rt = ip_route_output_flow(net, &fl4, sk); 788 if (IS_ERR(rt)) { 789 err = PTR_ERR(rt); 790 rt = NULL; 791 if (err == -ENETUNREACH) 792 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 793 goto out; 794 } 795 796 err = -EACCES; 797 if ((rt->rt_flags & RTCF_BROADCAST) && 798 !sock_flag(sk, SOCK_BROADCAST)) 799 goto out; 800 801 if (msg->msg_flags & MSG_CONFIRM) 802 goto do_confirm; 803 back_from_confirm: 804 805 if (!ipc.addr) 806 ipc.addr = fl4.daddr; 807 808 lock_sock(sk); 809 810 pfh.icmph.type = user_icmph.type; /* already checked */ 811 pfh.icmph.code = user_icmph.code; /* ditto */ 812 pfh.icmph.checksum = 0; 813 pfh.icmph.un.echo.id = inet->inet_sport; 814 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 815 pfh.msg = msg; 816 pfh.wcheck = 0; 817 pfh.family = AF_INET; 818 819 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 820 0, &ipc, &rt, msg->msg_flags); 821 if (err) 822 ip_flush_pending_frames(sk); 823 else 824 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 825 release_sock(sk); 826 827 out: 828 ip_rt_put(rt); 829 out_free: 830 if (free) 831 kfree(ipc.opt); 832 if (!err) { 833 icmp_out_count(sock_net(sk), user_icmph.type); 834 return len; 835 } 836 return err; 837 838 do_confirm: 839 if (msg->msg_flags & MSG_PROBE) 840 dst_confirm_neigh(&rt->dst, &fl4.daddr); 841 if (!(msg->msg_flags & MSG_PROBE) || len) 842 goto back_from_confirm; 843 err = 0; 844 goto out; 845 } 846 847 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 848 int flags, int *addr_len) 849 { 850 struct inet_sock *isk = inet_sk(sk); 851 int family = sk->sk_family; 852 struct sk_buff *skb; 853 int copied, err; 854 855 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 856 857 err = -EOPNOTSUPP; 858 if (flags & MSG_OOB) 859 goto out; 860 861 if (flags & MSG_ERRQUEUE) 862 return inet_recv_error(sk, msg, len, addr_len); 863 864 skb = skb_recv_datagram(sk, flags, noblock, &err); 865 if (!skb) 866 goto out; 867 868 copied = skb->len; 869 if (copied > len) { 870 msg->msg_flags |= MSG_TRUNC; 871 copied = len; 872 } 873 874 /* Don't bother checking the checksum */ 875 err = skb_copy_datagram_msg(skb, 0, msg, copied); 876 if (err) 877 goto done; 878 879 sock_recv_timestamp(msg, sk, skb); 880 881 /* Copy the address and add cmsg data. */ 882 if (family == AF_INET) { 883 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 884 885 if (sin) { 886 sin->sin_family = AF_INET; 887 sin->sin_port = 0 /* skb->h.uh->source */; 888 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 889 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 890 *addr_len = sizeof(*sin); 891 } 892 893 if (isk->cmsg_flags) 894 ip_cmsg_recv(msg, skb); 895 896 #if IS_ENABLED(CONFIG_IPV6) 897 } else if (family == AF_INET6) { 898 struct ipv6_pinfo *np = inet6_sk(sk); 899 struct ipv6hdr *ip6 = ipv6_hdr(skb); 900 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 901 902 if (sin6) { 903 sin6->sin6_family = AF_INET6; 904 sin6->sin6_port = 0; 905 sin6->sin6_addr = ip6->saddr; 906 sin6->sin6_flowinfo = 0; 907 if (np->sndflow) 908 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 909 sin6->sin6_scope_id = 910 ipv6_iface_scope_id(&sin6->sin6_addr, 911 inet6_iif(skb)); 912 *addr_len = sizeof(*sin6); 913 } 914 915 if (inet6_sk(sk)->rxopt.all) 916 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 917 if (skb->protocol == htons(ETH_P_IPV6) && 918 inet6_sk(sk)->rxopt.all) 919 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 920 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 921 ip_cmsg_recv(msg, skb); 922 #endif 923 } else { 924 BUG(); 925 } 926 927 err = copied; 928 929 done: 930 skb_free_datagram(sk, skb); 931 out: 932 pr_debug("ping_recvmsg -> %d\n", err); 933 return err; 934 } 935 EXPORT_SYMBOL_GPL(ping_recvmsg); 936 937 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 938 { 939 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 940 inet_sk(sk), inet_sk(sk)->inet_num, skb); 941 if (sock_queue_rcv_skb(sk, skb) < 0) { 942 kfree_skb(skb); 943 pr_debug("ping_queue_rcv_skb -> failed\n"); 944 return -1; 945 } 946 return 0; 947 } 948 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 949 950 951 /* 952 * All we need to do is get the socket. 953 */ 954 955 bool ping_rcv(struct sk_buff *skb) 956 { 957 struct sock *sk; 958 struct net *net = dev_net(skb->dev); 959 struct icmphdr *icmph = icmp_hdr(skb); 960 bool rc = false; 961 962 /* We assume the packet has already been checked by icmp_rcv */ 963 964 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 965 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 966 967 /* Push ICMP header back */ 968 skb_push(skb, skb->data - (u8 *)icmph); 969 970 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 971 if (sk) { 972 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 973 974 pr_debug("rcv on socket %p\n", sk); 975 if (skb2 && !ping_queue_rcv_skb(sk, skb2)) 976 rc = true; 977 sock_put(sk); 978 } 979 980 if (!rc) 981 pr_debug("no socket, dropping\n"); 982 983 return rc; 984 } 985 EXPORT_SYMBOL_GPL(ping_rcv); 986 987 struct proto ping_prot = { 988 .name = "PING", 989 .owner = THIS_MODULE, 990 .init = ping_init_sock, 991 .close = ping_close, 992 .connect = ip4_datagram_connect, 993 .disconnect = __udp_disconnect, 994 .setsockopt = ip_setsockopt, 995 .getsockopt = ip_getsockopt, 996 .sendmsg = ping_v4_sendmsg, 997 .recvmsg = ping_recvmsg, 998 .bind = ping_bind, 999 .backlog_rcv = ping_queue_rcv_skb, 1000 .release_cb = ip4_datagram_release_cb, 1001 .hash = ping_hash, 1002 .unhash = ping_unhash, 1003 .get_port = ping_get_port, 1004 .put_port = ping_unhash, 1005 .obj_size = sizeof(struct inet_sock), 1006 }; 1007 EXPORT_SYMBOL(ping_prot); 1008 1009 #ifdef CONFIG_PROC_FS 1010 1011 static struct sock *ping_get_first(struct seq_file *seq, int start) 1012 { 1013 struct sock *sk; 1014 struct ping_iter_state *state = seq->private; 1015 struct net *net = seq_file_net(seq); 1016 1017 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1018 ++state->bucket) { 1019 struct hlist_nulls_node *node; 1020 struct hlist_nulls_head *hslot; 1021 1022 hslot = &ping_table.hash[state->bucket]; 1023 1024 if (hlist_nulls_empty(hslot)) 1025 continue; 1026 1027 sk_nulls_for_each(sk, node, hslot) { 1028 if (net_eq(sock_net(sk), net) && 1029 sk->sk_family == state->family) 1030 goto found; 1031 } 1032 } 1033 sk = NULL; 1034 found: 1035 return sk; 1036 } 1037 1038 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1039 { 1040 struct ping_iter_state *state = seq->private; 1041 struct net *net = seq_file_net(seq); 1042 1043 do { 1044 sk = sk_nulls_next(sk); 1045 } while (sk && (!net_eq(sock_net(sk), net))); 1046 1047 if (!sk) 1048 return ping_get_first(seq, state->bucket + 1); 1049 return sk; 1050 } 1051 1052 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1053 { 1054 struct sock *sk = ping_get_first(seq, 0); 1055 1056 if (sk) 1057 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1058 --pos; 1059 return pos ? NULL : sk; 1060 } 1061 1062 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1063 __acquires(ping_table.lock) 1064 { 1065 struct ping_iter_state *state = seq->private; 1066 state->bucket = 0; 1067 state->family = family; 1068 1069 read_lock_bh(&ping_table.lock); 1070 1071 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1072 } 1073 EXPORT_SYMBOL_GPL(ping_seq_start); 1074 1075 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1076 { 1077 return ping_seq_start(seq, pos, AF_INET); 1078 } 1079 1080 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1081 { 1082 struct sock *sk; 1083 1084 if (v == SEQ_START_TOKEN) 1085 sk = ping_get_idx(seq, 0); 1086 else 1087 sk = ping_get_next(seq, v); 1088 1089 ++*pos; 1090 return sk; 1091 } 1092 EXPORT_SYMBOL_GPL(ping_seq_next); 1093 1094 void ping_seq_stop(struct seq_file *seq, void *v) 1095 __releases(ping_table.lock) 1096 { 1097 read_unlock_bh(&ping_table.lock); 1098 } 1099 EXPORT_SYMBOL_GPL(ping_seq_stop); 1100 1101 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1102 int bucket) 1103 { 1104 struct inet_sock *inet = inet_sk(sp); 1105 __be32 dest = inet->inet_daddr; 1106 __be32 src = inet->inet_rcv_saddr; 1107 __u16 destp = ntohs(inet->inet_dport); 1108 __u16 srcp = ntohs(inet->inet_sport); 1109 1110 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1111 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", 1112 bucket, src, srcp, dest, destp, sp->sk_state, 1113 sk_wmem_alloc_get(sp), 1114 sk_rmem_alloc_get(sp), 1115 0, 0L, 0, 1116 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1117 0, sock_i_ino(sp), 1118 refcount_read(&sp->sk_refcnt), sp, 1119 atomic_read(&sp->sk_drops)); 1120 } 1121 1122 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1123 { 1124 seq_setwidth(seq, 127); 1125 if (v == SEQ_START_TOKEN) 1126 seq_puts(seq, " sl local_address rem_address st tx_queue " 1127 "rx_queue tr tm->when retrnsmt uid timeout " 1128 "inode ref pointer drops"); 1129 else { 1130 struct ping_iter_state *state = seq->private; 1131 1132 ping_v4_format_sock(v, seq, state->bucket); 1133 } 1134 seq_pad(seq, '\n'); 1135 return 0; 1136 } 1137 1138 static const struct seq_operations ping_v4_seq_ops = { 1139 .start = ping_v4_seq_start, 1140 .show = ping_v4_seq_show, 1141 .next = ping_seq_next, 1142 .stop = ping_seq_stop, 1143 }; 1144 1145 static int __net_init ping_v4_proc_init_net(struct net *net) 1146 { 1147 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops, 1148 sizeof(struct ping_iter_state))) 1149 return -ENOMEM; 1150 return 0; 1151 } 1152 1153 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1154 { 1155 remove_proc_entry("icmp", net->proc_net); 1156 } 1157 1158 static struct pernet_operations ping_v4_net_ops = { 1159 .init = ping_v4_proc_init_net, 1160 .exit = ping_v4_proc_exit_net, 1161 }; 1162 1163 int __init ping_proc_init(void) 1164 { 1165 return register_pernet_subsys(&ping_v4_net_ops); 1166 } 1167 1168 void ping_proc_exit(void) 1169 { 1170 unregister_pernet_subsys(&ping_v4_net_ops); 1171 } 1172 1173 #endif 1174 1175 void __init ping_init(void) 1176 { 1177 int i; 1178 1179 for (i = 0; i < PING_HTABLE_SIZE; i++) 1180 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1181 rwlock_init(&ping_table.lock); 1182 } 1183