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