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 struct net *net = sock_net(sk); 298 if (sk->sk_family == AF_INET) { 299 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 300 int chk_addr_ret; 301 302 if (addr_len < sizeof(*addr)) 303 return -EINVAL; 304 305 if (addr->sin_family != AF_INET && 306 !(addr->sin_family == AF_UNSPEC && 307 addr->sin_addr.s_addr == htonl(INADDR_ANY))) 308 return -EAFNOSUPPORT; 309 310 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 311 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 312 313 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); 314 315 if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) 316 chk_addr_ret = RTN_LOCAL; 317 318 if ((!inet_can_nonlocal_bind(net, isk) && 319 chk_addr_ret != RTN_LOCAL) || 320 chk_addr_ret == RTN_MULTICAST || 321 chk_addr_ret == RTN_BROADCAST) 322 return -EADDRNOTAVAIL; 323 324 #if IS_ENABLED(CONFIG_IPV6) 325 } else if (sk->sk_family == AF_INET6) { 326 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 327 int addr_type, scoped, has_addr; 328 struct net_device *dev = NULL; 329 330 if (addr_len < sizeof(*addr)) 331 return -EINVAL; 332 333 if (addr->sin6_family != AF_INET6) 334 return -EAFNOSUPPORT; 335 336 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 337 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 338 339 addr_type = ipv6_addr_type(&addr->sin6_addr); 340 scoped = __ipv6_addr_needs_scope_id(addr_type); 341 if ((addr_type != IPV6_ADDR_ANY && 342 !(addr_type & IPV6_ADDR_UNICAST)) || 343 (scoped && !addr->sin6_scope_id)) 344 return -EINVAL; 345 346 rcu_read_lock(); 347 if (addr->sin6_scope_id) { 348 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 349 if (!dev) { 350 rcu_read_unlock(); 351 return -ENODEV; 352 } 353 } 354 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 355 scoped); 356 rcu_read_unlock(); 357 358 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr || 359 addr_type == IPV6_ADDR_ANY)) 360 return -EADDRNOTAVAIL; 361 362 if (scoped) 363 sk->sk_bound_dev_if = addr->sin6_scope_id; 364 #endif 365 } else { 366 return -EAFNOSUPPORT; 367 } 368 return 0; 369 } 370 371 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 372 { 373 if (saddr->sa_family == AF_INET) { 374 struct inet_sock *isk = inet_sk(sk); 375 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 376 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 377 #if IS_ENABLED(CONFIG_IPV6) 378 } else if (saddr->sa_family == AF_INET6) { 379 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 380 struct ipv6_pinfo *np = inet6_sk(sk); 381 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 382 #endif 383 } 384 } 385 386 static void ping_clear_saddr(struct sock *sk, int dif) 387 { 388 sk->sk_bound_dev_if = dif; 389 if (sk->sk_family == AF_INET) { 390 struct inet_sock *isk = inet_sk(sk); 391 isk->inet_rcv_saddr = isk->inet_saddr = 0; 392 #if IS_ENABLED(CONFIG_IPV6) 393 } else if (sk->sk_family == AF_INET6) { 394 struct ipv6_pinfo *np = inet6_sk(sk); 395 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 396 memset(&np->saddr, 0, sizeof(np->saddr)); 397 #endif 398 } 399 } 400 /* 401 * We need our own bind because there are no privileged id's == local ports. 402 * Moreover, we don't allow binding to multi- and broadcast addresses. 403 */ 404 405 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 406 { 407 struct inet_sock *isk = inet_sk(sk); 408 unsigned short snum; 409 int err; 410 int dif = sk->sk_bound_dev_if; 411 412 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 413 if (err) 414 return err; 415 416 lock_sock(sk); 417 418 err = -EINVAL; 419 if (isk->inet_num != 0) 420 goto out; 421 422 err = -EADDRINUSE; 423 ping_set_saddr(sk, uaddr); 424 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 425 if (ping_get_port(sk, snum) != 0) { 426 ping_clear_saddr(sk, dif); 427 goto out; 428 } 429 430 pr_debug("after bind(): num = %hu, dif = %d\n", 431 isk->inet_num, 432 sk->sk_bound_dev_if); 433 434 err = 0; 435 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 436 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 437 #if IS_ENABLED(CONFIG_IPV6) 438 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 439 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 440 #endif 441 442 if (snum) 443 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 444 isk->inet_sport = htons(isk->inet_num); 445 isk->inet_daddr = 0; 446 isk->inet_dport = 0; 447 448 #if IS_ENABLED(CONFIG_IPV6) 449 if (sk->sk_family == AF_INET6) 450 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 451 #endif 452 453 sk_dst_reset(sk); 454 out: 455 release_sock(sk); 456 pr_debug("ping_v4_bind -> %d\n", err); 457 return err; 458 } 459 EXPORT_SYMBOL_GPL(ping_bind); 460 461 /* 462 * Is this a supported type of ICMP message? 463 */ 464 465 static inline int ping_supported(int family, int type, int code) 466 { 467 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 468 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0); 469 } 470 471 /* 472 * This routine is called by the ICMP module when it gets some 473 * sort of error condition. 474 */ 475 476 void ping_err(struct sk_buff *skb, int offset, u32 info) 477 { 478 int family; 479 struct icmphdr *icmph; 480 struct inet_sock *inet_sock; 481 int type; 482 int code; 483 struct net *net = dev_net(skb->dev); 484 struct sock *sk; 485 int harderr; 486 int err; 487 488 if (skb->protocol == htons(ETH_P_IP)) { 489 family = AF_INET; 490 type = icmp_hdr(skb)->type; 491 code = icmp_hdr(skb)->code; 492 icmph = (struct icmphdr *)(skb->data + offset); 493 } else if (skb->protocol == htons(ETH_P_IPV6)) { 494 family = AF_INET6; 495 type = icmp6_hdr(skb)->icmp6_type; 496 code = icmp6_hdr(skb)->icmp6_code; 497 icmph = (struct icmphdr *) (skb->data + offset); 498 } else { 499 BUG(); 500 } 501 502 /* We assume the packet has already been checked by icmp_unreach */ 503 504 if (!ping_supported(family, icmph->type, icmph->code)) 505 return; 506 507 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 508 skb->protocol, type, code, ntohs(icmph->un.echo.id), 509 ntohs(icmph->un.echo.sequence)); 510 511 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 512 if (!sk) { 513 pr_debug("no socket, dropping\n"); 514 return; /* No socket for error */ 515 } 516 pr_debug("err on socket %p\n", sk); 517 518 err = 0; 519 harderr = 0; 520 inet_sock = inet_sk(sk); 521 522 if (skb->protocol == htons(ETH_P_IP)) { 523 switch (type) { 524 default: 525 case ICMP_TIME_EXCEEDED: 526 err = EHOSTUNREACH; 527 break; 528 case ICMP_SOURCE_QUENCH: 529 /* This is not a real error but ping wants to see it. 530 * Report it with some fake errno. 531 */ 532 err = EREMOTEIO; 533 break; 534 case ICMP_PARAMETERPROB: 535 err = EPROTO; 536 harderr = 1; 537 break; 538 case ICMP_DEST_UNREACH: 539 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 540 ipv4_sk_update_pmtu(skb, sk, info); 541 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 542 err = EMSGSIZE; 543 harderr = 1; 544 break; 545 } 546 goto out; 547 } 548 err = EHOSTUNREACH; 549 if (code <= NR_ICMP_UNREACH) { 550 harderr = icmp_err_convert[code].fatal; 551 err = icmp_err_convert[code].errno; 552 } 553 break; 554 case ICMP_REDIRECT: 555 /* See ICMP_SOURCE_QUENCH */ 556 ipv4_sk_redirect(skb, sk); 557 err = EREMOTEIO; 558 break; 559 } 560 #if IS_ENABLED(CONFIG_IPV6) 561 } else if (skb->protocol == htons(ETH_P_IPV6)) { 562 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 563 #endif 564 } 565 566 /* 567 * RFC1122: OK. Passes ICMP errors back to application, as per 568 * 4.1.3.3. 569 */ 570 if ((family == AF_INET && !inet_sock->recverr) || 571 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 572 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 573 goto out; 574 } else { 575 if (family == AF_INET) { 576 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 577 info, (u8 *)icmph); 578 #if IS_ENABLED(CONFIG_IPV6) 579 } else if (family == AF_INET6) { 580 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 581 info, (u8 *)icmph); 582 #endif 583 } 584 } 585 sk->sk_err = err; 586 sk->sk_error_report(sk); 587 out: 588 sock_put(sk); 589 } 590 EXPORT_SYMBOL_GPL(ping_err); 591 592 /* 593 * Copy and checksum an ICMP Echo packet from user space into a buffer 594 * starting from the payload. 595 */ 596 597 int ping_getfrag(void *from, char *to, 598 int offset, int fraglen, int odd, struct sk_buff *skb) 599 { 600 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 601 602 if (offset == 0) { 603 fraglen -= sizeof(struct icmphdr); 604 if (fraglen < 0) 605 BUG(); 606 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), 607 fraglen, &pfh->wcheck, 608 &pfh->msg->msg_iter)) 609 return -EFAULT; 610 } else if (offset < sizeof(struct icmphdr)) { 611 BUG(); 612 } else { 613 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, 614 &pfh->msg->msg_iter)) 615 return -EFAULT; 616 } 617 618 #if IS_ENABLED(CONFIG_IPV6) 619 /* For IPv6, checksum each skb as we go along, as expected by 620 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 621 * wcheck, it will be finalized in ping_v4_push_pending_frames. 622 */ 623 if (pfh->family == AF_INET6) { 624 skb->csum = pfh->wcheck; 625 skb->ip_summed = CHECKSUM_NONE; 626 pfh->wcheck = 0; 627 } 628 #endif 629 630 return 0; 631 } 632 EXPORT_SYMBOL_GPL(ping_getfrag); 633 634 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 635 struct flowi4 *fl4) 636 { 637 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 638 639 if (!skb) 640 return 0; 641 pfh->wcheck = csum_partial((char *)&pfh->icmph, 642 sizeof(struct icmphdr), pfh->wcheck); 643 pfh->icmph.checksum = csum_fold(pfh->wcheck); 644 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 645 skb->ip_summed = CHECKSUM_NONE; 646 return ip_push_pending_frames(sk, fl4); 647 } 648 649 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 650 void *user_icmph, size_t icmph_len) { 651 u8 type, code; 652 653 if (len > 0xFFFF) 654 return -EMSGSIZE; 655 656 /* Must have at least a full ICMP header. */ 657 if (len < icmph_len) 658 return -EINVAL; 659 660 /* 661 * Check the flags. 662 */ 663 664 /* Mirror BSD error message compatibility */ 665 if (msg->msg_flags & MSG_OOB) 666 return -EOPNOTSUPP; 667 668 /* 669 * Fetch the ICMP header provided by the userland. 670 * iovec is modified! The ICMP header is consumed. 671 */ 672 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 673 return -EFAULT; 674 675 if (family == AF_INET) { 676 type = ((struct icmphdr *) user_icmph)->type; 677 code = ((struct icmphdr *) user_icmph)->code; 678 #if IS_ENABLED(CONFIG_IPV6) 679 } else if (family == AF_INET6) { 680 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 681 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 682 #endif 683 } else { 684 BUG(); 685 } 686 687 if (!ping_supported(family, type, code)) 688 return -EINVAL; 689 690 return 0; 691 } 692 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 693 694 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 695 { 696 struct net *net = sock_net(sk); 697 struct flowi4 fl4; 698 struct inet_sock *inet = inet_sk(sk); 699 struct ipcm_cookie ipc; 700 struct icmphdr user_icmph; 701 struct pingfakehdr pfh; 702 struct rtable *rt = NULL; 703 struct ip_options_data opt_copy; 704 int free = 0; 705 __be32 saddr, daddr, faddr; 706 u8 tos; 707 int err; 708 709 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 710 711 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 712 sizeof(user_icmph)); 713 if (err) 714 return err; 715 716 /* 717 * Get and verify the address. 718 */ 719 720 if (msg->msg_name) { 721 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 722 if (msg->msg_namelen < sizeof(*usin)) 723 return -EINVAL; 724 if (usin->sin_family != AF_INET) 725 return -EAFNOSUPPORT; 726 daddr = usin->sin_addr.s_addr; 727 /* no remote port */ 728 } else { 729 if (sk->sk_state != TCP_ESTABLISHED) 730 return -EDESTADDRREQ; 731 daddr = inet->inet_daddr; 732 /* no remote port */ 733 } 734 735 ipcm_init_sk(&ipc, inet); 736 737 if (msg->msg_controllen) { 738 err = ip_cmsg_send(sk, msg, &ipc, false); 739 if (unlikely(err)) { 740 kfree(ipc.opt); 741 return err; 742 } 743 if (ipc.opt) 744 free = 1; 745 } 746 if (!ipc.opt) { 747 struct ip_options_rcu *inet_opt; 748 749 rcu_read_lock(); 750 inet_opt = rcu_dereference(inet->inet_opt); 751 if (inet_opt) { 752 memcpy(&opt_copy, inet_opt, 753 sizeof(*inet_opt) + inet_opt->opt.optlen); 754 ipc.opt = &opt_copy.opt; 755 } 756 rcu_read_unlock(); 757 } 758 759 saddr = ipc.addr; 760 ipc.addr = faddr = daddr; 761 762 if (ipc.opt && ipc.opt->opt.srr) { 763 if (!daddr) { 764 err = -EINVAL; 765 goto out_free; 766 } 767 faddr = ipc.opt->opt.faddr; 768 } 769 tos = get_rttos(&ipc, inet); 770 if (sock_flag(sk, SOCK_LOCALROUTE) || 771 (msg->msg_flags & MSG_DONTROUTE) || 772 (ipc.opt && ipc.opt->opt.is_strictroute)) { 773 tos |= RTO_ONLINK; 774 } 775 776 if (ipv4_is_multicast(daddr)) { 777 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 778 ipc.oif = inet->mc_index; 779 if (!saddr) 780 saddr = inet->mc_addr; 781 } else if (!ipc.oif) 782 ipc.oif = inet->uc_index; 783 784 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, 785 RT_SCOPE_UNIVERSE, sk->sk_protocol, 786 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 787 sk->sk_uid); 788 789 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 790 rt = ip_route_output_flow(net, &fl4, sk); 791 if (IS_ERR(rt)) { 792 err = PTR_ERR(rt); 793 rt = NULL; 794 if (err == -ENETUNREACH) 795 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 796 goto out; 797 } 798 799 err = -EACCES; 800 if ((rt->rt_flags & RTCF_BROADCAST) && 801 !sock_flag(sk, SOCK_BROADCAST)) 802 goto out; 803 804 if (msg->msg_flags & MSG_CONFIRM) 805 goto do_confirm; 806 back_from_confirm: 807 808 if (!ipc.addr) 809 ipc.addr = fl4.daddr; 810 811 lock_sock(sk); 812 813 pfh.icmph.type = user_icmph.type; /* already checked */ 814 pfh.icmph.code = user_icmph.code; /* ditto */ 815 pfh.icmph.checksum = 0; 816 pfh.icmph.un.echo.id = inet->inet_sport; 817 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 818 pfh.msg = msg; 819 pfh.wcheck = 0; 820 pfh.family = AF_INET; 821 822 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 823 0, &ipc, &rt, msg->msg_flags); 824 if (err) 825 ip_flush_pending_frames(sk); 826 else 827 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 828 release_sock(sk); 829 830 out: 831 ip_rt_put(rt); 832 out_free: 833 if (free) 834 kfree(ipc.opt); 835 if (!err) { 836 icmp_out_count(sock_net(sk), user_icmph.type); 837 return len; 838 } 839 return err; 840 841 do_confirm: 842 if (msg->msg_flags & MSG_PROBE) 843 dst_confirm_neigh(&rt->dst, &fl4.daddr); 844 if (!(msg->msg_flags & MSG_PROBE) || len) 845 goto back_from_confirm; 846 err = 0; 847 goto out; 848 } 849 850 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 851 int flags, int *addr_len) 852 { 853 struct inet_sock *isk = inet_sk(sk); 854 int family = sk->sk_family; 855 struct sk_buff *skb; 856 int copied, err; 857 858 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 859 860 err = -EOPNOTSUPP; 861 if (flags & MSG_OOB) 862 goto out; 863 864 if (flags & MSG_ERRQUEUE) 865 return inet_recv_error(sk, msg, len, addr_len); 866 867 skb = skb_recv_datagram(sk, flags, noblock, &err); 868 if (!skb) 869 goto out; 870 871 copied = skb->len; 872 if (copied > len) { 873 msg->msg_flags |= MSG_TRUNC; 874 copied = len; 875 } 876 877 /* Don't bother checking the checksum */ 878 err = skb_copy_datagram_msg(skb, 0, msg, copied); 879 if (err) 880 goto done; 881 882 sock_recv_timestamp(msg, sk, skb); 883 884 /* Copy the address and add cmsg data. */ 885 if (family == AF_INET) { 886 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 887 888 if (sin) { 889 sin->sin_family = AF_INET; 890 sin->sin_port = 0 /* skb->h.uh->source */; 891 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 892 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 893 *addr_len = sizeof(*sin); 894 } 895 896 if (isk->cmsg_flags) 897 ip_cmsg_recv(msg, skb); 898 899 #if IS_ENABLED(CONFIG_IPV6) 900 } else if (family == AF_INET6) { 901 struct ipv6_pinfo *np = inet6_sk(sk); 902 struct ipv6hdr *ip6 = ipv6_hdr(skb); 903 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 904 905 if (sin6) { 906 sin6->sin6_family = AF_INET6; 907 sin6->sin6_port = 0; 908 sin6->sin6_addr = ip6->saddr; 909 sin6->sin6_flowinfo = 0; 910 if (np->sndflow) 911 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 912 sin6->sin6_scope_id = 913 ipv6_iface_scope_id(&sin6->sin6_addr, 914 inet6_iif(skb)); 915 *addr_len = sizeof(*sin6); 916 } 917 918 if (inet6_sk(sk)->rxopt.all) 919 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 920 if (skb->protocol == htons(ETH_P_IPV6) && 921 inet6_sk(sk)->rxopt.all) 922 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 923 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 924 ip_cmsg_recv(msg, skb); 925 #endif 926 } else { 927 BUG(); 928 } 929 930 err = copied; 931 932 done: 933 skb_free_datagram(sk, skb); 934 out: 935 pr_debug("ping_recvmsg -> %d\n", err); 936 return err; 937 } 938 EXPORT_SYMBOL_GPL(ping_recvmsg); 939 940 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 941 { 942 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 943 inet_sk(sk), inet_sk(sk)->inet_num, skb); 944 if (sock_queue_rcv_skb(sk, skb) < 0) { 945 kfree_skb(skb); 946 pr_debug("ping_queue_rcv_skb -> failed\n"); 947 return -1; 948 } 949 return 0; 950 } 951 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 952 953 954 /* 955 * All we need to do is get the socket. 956 */ 957 958 bool ping_rcv(struct sk_buff *skb) 959 { 960 struct sock *sk; 961 struct net *net = dev_net(skb->dev); 962 struct icmphdr *icmph = icmp_hdr(skb); 963 964 /* We assume the packet has already been checked by icmp_rcv */ 965 966 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 967 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 968 969 /* Push ICMP header back */ 970 skb_push(skb, skb->data - (u8 *)icmph); 971 972 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 973 if (sk) { 974 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 975 976 pr_debug("rcv on socket %p\n", sk); 977 if (skb2) 978 ping_queue_rcv_skb(sk, skb2); 979 sock_put(sk); 980 return true; 981 } 982 pr_debug("no socket, dropping\n"); 983 984 return false; 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 .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