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_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0); 457 } 458 459 /* 460 * This routine is called by the ICMP module when it gets some 461 * sort of error condition. 462 */ 463 464 void ping_err(struct sk_buff *skb, int offset, u32 info) 465 { 466 int family; 467 struct icmphdr *icmph; 468 struct inet_sock *inet_sock; 469 int type; 470 int code; 471 struct net *net = dev_net(skb->dev); 472 struct sock *sk; 473 int harderr; 474 int err; 475 476 if (skb->protocol == htons(ETH_P_IP)) { 477 family = AF_INET; 478 type = icmp_hdr(skb)->type; 479 code = icmp_hdr(skb)->code; 480 icmph = (struct icmphdr *)(skb->data + offset); 481 } else if (skb->protocol == htons(ETH_P_IPV6)) { 482 family = AF_INET6; 483 type = icmp6_hdr(skb)->icmp6_type; 484 code = icmp6_hdr(skb)->icmp6_code; 485 icmph = (struct icmphdr *) (skb->data + offset); 486 } else { 487 BUG(); 488 } 489 490 /* We assume the packet has already been checked by icmp_unreach */ 491 492 if (!ping_supported(family, icmph->type, icmph->code)) 493 return; 494 495 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 496 skb->protocol, type, code, ntohs(icmph->un.echo.id), 497 ntohs(icmph->un.echo.sequence)); 498 499 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 500 if (!sk) { 501 pr_debug("no socket, dropping\n"); 502 return; /* No socket for error */ 503 } 504 pr_debug("err on socket %p\n", sk); 505 506 err = 0; 507 harderr = 0; 508 inet_sock = inet_sk(sk); 509 510 if (skb->protocol == htons(ETH_P_IP)) { 511 switch (type) { 512 default: 513 case ICMP_TIME_EXCEEDED: 514 err = EHOSTUNREACH; 515 break; 516 case ICMP_SOURCE_QUENCH: 517 /* This is not a real error but ping wants to see it. 518 * Report it with some fake errno. 519 */ 520 err = EREMOTEIO; 521 break; 522 case ICMP_PARAMETERPROB: 523 err = EPROTO; 524 harderr = 1; 525 break; 526 case ICMP_DEST_UNREACH: 527 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 528 ipv4_sk_update_pmtu(skb, sk, info); 529 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 530 err = EMSGSIZE; 531 harderr = 1; 532 break; 533 } 534 goto out; 535 } 536 err = EHOSTUNREACH; 537 if (code <= NR_ICMP_UNREACH) { 538 harderr = icmp_err_convert[code].fatal; 539 err = icmp_err_convert[code].errno; 540 } 541 break; 542 case ICMP_REDIRECT: 543 /* See ICMP_SOURCE_QUENCH */ 544 ipv4_sk_redirect(skb, sk); 545 err = EREMOTEIO; 546 break; 547 } 548 #if IS_ENABLED(CONFIG_IPV6) 549 } else if (skb->protocol == htons(ETH_P_IPV6)) { 550 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 551 #endif 552 } 553 554 /* 555 * RFC1122: OK. Passes ICMP errors back to application, as per 556 * 4.1.3.3. 557 */ 558 if ((family == AF_INET && !inet_sock->recverr) || 559 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 560 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 561 goto out; 562 } else { 563 if (family == AF_INET) { 564 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 565 info, (u8 *)icmph); 566 #if IS_ENABLED(CONFIG_IPV6) 567 } else if (family == AF_INET6) { 568 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 569 info, (u8 *)icmph); 570 #endif 571 } 572 } 573 sk->sk_err = err; 574 sk->sk_error_report(sk); 575 out: 576 sock_put(sk); 577 } 578 EXPORT_SYMBOL_GPL(ping_err); 579 580 /* 581 * Copy and checksum an ICMP Echo packet from user space into a buffer 582 * starting from the payload. 583 */ 584 585 int ping_getfrag(void *from, char *to, 586 int offset, int fraglen, int odd, struct sk_buff *skb) 587 { 588 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 589 590 if (offset == 0) { 591 fraglen -= sizeof(struct icmphdr); 592 if (fraglen < 0) 593 BUG(); 594 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), 595 fraglen, &pfh->wcheck, 596 &pfh->msg->msg_iter)) 597 return -EFAULT; 598 } else if (offset < sizeof(struct icmphdr)) { 599 BUG(); 600 } else { 601 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, 602 &pfh->msg->msg_iter)) 603 return -EFAULT; 604 } 605 606 #if IS_ENABLED(CONFIG_IPV6) 607 /* For IPv6, checksum each skb as we go along, as expected by 608 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 609 * wcheck, it will be finalized in ping_v4_push_pending_frames. 610 */ 611 if (pfh->family == AF_INET6) { 612 skb->csum = pfh->wcheck; 613 skb->ip_summed = CHECKSUM_NONE; 614 pfh->wcheck = 0; 615 } 616 #endif 617 618 return 0; 619 } 620 EXPORT_SYMBOL_GPL(ping_getfrag); 621 622 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 623 struct flowi4 *fl4) 624 { 625 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 626 627 if (!skb) 628 return 0; 629 pfh->wcheck = csum_partial((char *)&pfh->icmph, 630 sizeof(struct icmphdr), pfh->wcheck); 631 pfh->icmph.checksum = csum_fold(pfh->wcheck); 632 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 633 skb->ip_summed = CHECKSUM_NONE; 634 return ip_push_pending_frames(sk, fl4); 635 } 636 637 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 638 void *user_icmph, size_t icmph_len) 639 { 640 u8 type, code; 641 642 if (len > 0xFFFF) 643 return -EMSGSIZE; 644 645 /* Must have at least a full ICMP header. */ 646 if (len < icmph_len) 647 return -EINVAL; 648 649 /* 650 * Check the flags. 651 */ 652 653 /* Mirror BSD error message compatibility */ 654 if (msg->msg_flags & MSG_OOB) 655 return -EOPNOTSUPP; 656 657 /* 658 * Fetch the ICMP header provided by the userland. 659 * iovec is modified! The ICMP header is consumed. 660 */ 661 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 662 return -EFAULT; 663 664 if (family == AF_INET) { 665 type = ((struct icmphdr *) user_icmph)->type; 666 code = ((struct icmphdr *) user_icmph)->code; 667 #if IS_ENABLED(CONFIG_IPV6) 668 } else if (family == AF_INET6) { 669 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 670 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 671 #endif 672 } else { 673 BUG(); 674 } 675 676 if (!ping_supported(family, type, code)) 677 return -EINVAL; 678 679 return 0; 680 } 681 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 682 683 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 684 { 685 struct net *net = sock_net(sk); 686 struct flowi4 fl4; 687 struct inet_sock *inet = inet_sk(sk); 688 struct ipcm_cookie ipc; 689 struct icmphdr user_icmph; 690 struct pingfakehdr pfh; 691 struct rtable *rt = NULL; 692 struct ip_options_data opt_copy; 693 int free = 0; 694 __be32 saddr, daddr, faddr; 695 u8 tos; 696 int err; 697 698 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 699 700 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 701 sizeof(user_icmph)); 702 if (err) 703 return err; 704 705 /* 706 * Get and verify the address. 707 */ 708 709 if (msg->msg_name) { 710 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 711 if (msg->msg_namelen < sizeof(*usin)) 712 return -EINVAL; 713 if (usin->sin_family != AF_INET) 714 return -EAFNOSUPPORT; 715 daddr = usin->sin_addr.s_addr; 716 /* no remote port */ 717 } else { 718 if (sk->sk_state != TCP_ESTABLISHED) 719 return -EDESTADDRREQ; 720 daddr = inet->inet_daddr; 721 /* no remote port */ 722 } 723 724 ipcm_init_sk(&ipc, inet); 725 726 if (msg->msg_controllen) { 727 err = ip_cmsg_send(sk, msg, &ipc, false); 728 if (unlikely(err)) { 729 kfree(ipc.opt); 730 return err; 731 } 732 if (ipc.opt) 733 free = 1; 734 } 735 if (!ipc.opt) { 736 struct ip_options_rcu *inet_opt; 737 738 rcu_read_lock(); 739 inet_opt = rcu_dereference(inet->inet_opt); 740 if (inet_opt) { 741 memcpy(&opt_copy, inet_opt, 742 sizeof(*inet_opt) + inet_opt->opt.optlen); 743 ipc.opt = &opt_copy.opt; 744 } 745 rcu_read_unlock(); 746 } 747 748 saddr = ipc.addr; 749 ipc.addr = faddr = daddr; 750 751 if (ipc.opt && ipc.opt->opt.srr) { 752 if (!daddr) { 753 err = -EINVAL; 754 goto out_free; 755 } 756 faddr = ipc.opt->opt.faddr; 757 } 758 tos = get_rttos(&ipc, inet); 759 if (sock_flag(sk, SOCK_LOCALROUTE) || 760 (msg->msg_flags & MSG_DONTROUTE) || 761 (ipc.opt && ipc.opt->opt.is_strictroute)) { 762 tos |= RTO_ONLINK; 763 } 764 765 if (ipv4_is_multicast(daddr)) { 766 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 767 ipc.oif = inet->mc_index; 768 if (!saddr) 769 saddr = inet->mc_addr; 770 } else if (!ipc.oif) 771 ipc.oif = inet->uc_index; 772 773 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, 774 RT_SCOPE_UNIVERSE, sk->sk_protocol, 775 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 776 sk->sk_uid); 777 778 fl4.fl4_icmp_type = user_icmph.type; 779 fl4.fl4_icmp_code = user_icmph.code; 780 781 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4)); 782 rt = ip_route_output_flow(net, &fl4, sk); 783 if (IS_ERR(rt)) { 784 err = PTR_ERR(rt); 785 rt = NULL; 786 if (err == -ENETUNREACH) 787 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 788 goto out; 789 } 790 791 err = -EACCES; 792 if ((rt->rt_flags & RTCF_BROADCAST) && 793 !sock_flag(sk, SOCK_BROADCAST)) 794 goto out; 795 796 if (msg->msg_flags & MSG_CONFIRM) 797 goto do_confirm; 798 back_from_confirm: 799 800 if (!ipc.addr) 801 ipc.addr = fl4.daddr; 802 803 lock_sock(sk); 804 805 pfh.icmph.type = user_icmph.type; /* already checked */ 806 pfh.icmph.code = user_icmph.code; /* ditto */ 807 pfh.icmph.checksum = 0; 808 pfh.icmph.un.echo.id = inet->inet_sport; 809 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 810 pfh.msg = msg; 811 pfh.wcheck = 0; 812 pfh.family = AF_INET; 813 814 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 815 0, &ipc, &rt, msg->msg_flags); 816 if (err) 817 ip_flush_pending_frames(sk); 818 else 819 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 820 release_sock(sk); 821 822 out: 823 ip_rt_put(rt); 824 out_free: 825 if (free) 826 kfree(ipc.opt); 827 if (!err) { 828 icmp_out_count(sock_net(sk), user_icmph.type); 829 return len; 830 } 831 return err; 832 833 do_confirm: 834 if (msg->msg_flags & MSG_PROBE) 835 dst_confirm_neigh(&rt->dst, &fl4.daddr); 836 if (!(msg->msg_flags & MSG_PROBE) || len) 837 goto back_from_confirm; 838 err = 0; 839 goto out; 840 } 841 842 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 843 int flags, int *addr_len) 844 { 845 struct inet_sock *isk = inet_sk(sk); 846 int family = sk->sk_family; 847 struct sk_buff *skb; 848 int copied, err; 849 850 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 851 852 err = -EOPNOTSUPP; 853 if (flags & MSG_OOB) 854 goto out; 855 856 if (flags & MSG_ERRQUEUE) 857 return inet_recv_error(sk, msg, len, addr_len); 858 859 skb = skb_recv_datagram(sk, flags, noblock, &err); 860 if (!skb) 861 goto out; 862 863 copied = skb->len; 864 if (copied > len) { 865 msg->msg_flags |= MSG_TRUNC; 866 copied = len; 867 } 868 869 /* Don't bother checking the checksum */ 870 err = skb_copy_datagram_msg(skb, 0, msg, copied); 871 if (err) 872 goto done; 873 874 sock_recv_timestamp(msg, sk, skb); 875 876 /* Copy the address and add cmsg data. */ 877 if (family == AF_INET) { 878 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 879 880 if (sin) { 881 sin->sin_family = AF_INET; 882 sin->sin_port = 0 /* skb->h.uh->source */; 883 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 884 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 885 *addr_len = sizeof(*sin); 886 } 887 888 if (isk->cmsg_flags) 889 ip_cmsg_recv(msg, skb); 890 891 #if IS_ENABLED(CONFIG_IPV6) 892 } else if (family == AF_INET6) { 893 struct ipv6_pinfo *np = inet6_sk(sk); 894 struct ipv6hdr *ip6 = ipv6_hdr(skb); 895 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 896 897 if (sin6) { 898 sin6->sin6_family = AF_INET6; 899 sin6->sin6_port = 0; 900 sin6->sin6_addr = ip6->saddr; 901 sin6->sin6_flowinfo = 0; 902 if (np->sndflow) 903 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 904 sin6->sin6_scope_id = 905 ipv6_iface_scope_id(&sin6->sin6_addr, 906 inet6_iif(skb)); 907 *addr_len = sizeof(*sin6); 908 } 909 910 if (inet6_sk(sk)->rxopt.all) 911 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 912 if (skb->protocol == htons(ETH_P_IPV6) && 913 inet6_sk(sk)->rxopt.all) 914 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 915 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 916 ip_cmsg_recv(msg, skb); 917 #endif 918 } else { 919 BUG(); 920 } 921 922 err = copied; 923 924 done: 925 skb_free_datagram(sk, skb); 926 out: 927 pr_debug("ping_recvmsg -> %d\n", err); 928 return err; 929 } 930 EXPORT_SYMBOL_GPL(ping_recvmsg); 931 932 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 933 { 934 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 935 inet_sk(sk), inet_sk(sk)->inet_num, skb); 936 if (sock_queue_rcv_skb(sk, skb) < 0) { 937 kfree_skb(skb); 938 pr_debug("ping_queue_rcv_skb -> failed\n"); 939 return -1; 940 } 941 return 0; 942 } 943 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 944 945 946 /* 947 * All we need to do is get the socket. 948 */ 949 950 bool ping_rcv(struct sk_buff *skb) 951 { 952 struct sock *sk; 953 struct net *net = dev_net(skb->dev); 954 struct icmphdr *icmph = icmp_hdr(skb); 955 956 /* We assume the packet has already been checked by icmp_rcv */ 957 958 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 959 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 960 961 /* Push ICMP header back */ 962 skb_push(skb, skb->data - (u8 *)icmph); 963 964 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 965 if (sk) { 966 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 967 968 pr_debug("rcv on socket %p\n", sk); 969 if (skb2) 970 ping_queue_rcv_skb(sk, skb2); 971 sock_put(sk); 972 return true; 973 } 974 pr_debug("no socket, dropping\n"); 975 976 return false; 977 } 978 EXPORT_SYMBOL_GPL(ping_rcv); 979 980 struct proto ping_prot = { 981 .name = "PING", 982 .owner = THIS_MODULE, 983 .init = ping_init_sock, 984 .close = ping_close, 985 .connect = ip4_datagram_connect, 986 .disconnect = __udp_disconnect, 987 .setsockopt = ip_setsockopt, 988 .getsockopt = ip_getsockopt, 989 .sendmsg = ping_v4_sendmsg, 990 .recvmsg = ping_recvmsg, 991 .bind = ping_bind, 992 .backlog_rcv = ping_queue_rcv_skb, 993 .release_cb = ip4_datagram_release_cb, 994 .hash = ping_hash, 995 .unhash = ping_unhash, 996 .get_port = ping_get_port, 997 .obj_size = sizeof(struct inet_sock), 998 }; 999 EXPORT_SYMBOL(ping_prot); 1000 1001 #ifdef CONFIG_PROC_FS 1002 1003 static struct sock *ping_get_first(struct seq_file *seq, int start) 1004 { 1005 struct sock *sk; 1006 struct ping_iter_state *state = seq->private; 1007 struct net *net = seq_file_net(seq); 1008 1009 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1010 ++state->bucket) { 1011 struct hlist_nulls_node *node; 1012 struct hlist_nulls_head *hslot; 1013 1014 hslot = &ping_table.hash[state->bucket]; 1015 1016 if (hlist_nulls_empty(hslot)) 1017 continue; 1018 1019 sk_nulls_for_each(sk, node, hslot) { 1020 if (net_eq(sock_net(sk), net) && 1021 sk->sk_family == state->family) 1022 goto found; 1023 } 1024 } 1025 sk = NULL; 1026 found: 1027 return sk; 1028 } 1029 1030 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1031 { 1032 struct ping_iter_state *state = seq->private; 1033 struct net *net = seq_file_net(seq); 1034 1035 do { 1036 sk = sk_nulls_next(sk); 1037 } while (sk && (!net_eq(sock_net(sk), net))); 1038 1039 if (!sk) 1040 return ping_get_first(seq, state->bucket + 1); 1041 return sk; 1042 } 1043 1044 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1045 { 1046 struct sock *sk = ping_get_first(seq, 0); 1047 1048 if (sk) 1049 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1050 --pos; 1051 return pos ? NULL : sk; 1052 } 1053 1054 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1055 __acquires(ping_table.lock) 1056 { 1057 struct ping_iter_state *state = seq->private; 1058 state->bucket = 0; 1059 state->family = family; 1060 1061 read_lock_bh(&ping_table.lock); 1062 1063 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1064 } 1065 EXPORT_SYMBOL_GPL(ping_seq_start); 1066 1067 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1068 { 1069 return ping_seq_start(seq, pos, AF_INET); 1070 } 1071 1072 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1073 { 1074 struct sock *sk; 1075 1076 if (v == SEQ_START_TOKEN) 1077 sk = ping_get_idx(seq, 0); 1078 else 1079 sk = ping_get_next(seq, v); 1080 1081 ++*pos; 1082 return sk; 1083 } 1084 EXPORT_SYMBOL_GPL(ping_seq_next); 1085 1086 void ping_seq_stop(struct seq_file *seq, void *v) 1087 __releases(ping_table.lock) 1088 { 1089 read_unlock_bh(&ping_table.lock); 1090 } 1091 EXPORT_SYMBOL_GPL(ping_seq_stop); 1092 1093 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1094 int bucket) 1095 { 1096 struct inet_sock *inet = inet_sk(sp); 1097 __be32 dest = inet->inet_daddr; 1098 __be32 src = inet->inet_rcv_saddr; 1099 __u16 destp = ntohs(inet->inet_dport); 1100 __u16 srcp = ntohs(inet->inet_sport); 1101 1102 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1103 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", 1104 bucket, src, srcp, dest, destp, sp->sk_state, 1105 sk_wmem_alloc_get(sp), 1106 sk_rmem_alloc_get(sp), 1107 0, 0L, 0, 1108 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1109 0, sock_i_ino(sp), 1110 refcount_read(&sp->sk_refcnt), sp, 1111 atomic_read(&sp->sk_drops)); 1112 } 1113 1114 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1115 { 1116 seq_setwidth(seq, 127); 1117 if (v == SEQ_START_TOKEN) 1118 seq_puts(seq, " sl local_address rem_address st tx_queue " 1119 "rx_queue tr tm->when retrnsmt uid timeout " 1120 "inode ref pointer drops"); 1121 else { 1122 struct ping_iter_state *state = seq->private; 1123 1124 ping_v4_format_sock(v, seq, state->bucket); 1125 } 1126 seq_pad(seq, '\n'); 1127 return 0; 1128 } 1129 1130 static const struct seq_operations ping_v4_seq_ops = { 1131 .start = ping_v4_seq_start, 1132 .show = ping_v4_seq_show, 1133 .next = ping_seq_next, 1134 .stop = ping_seq_stop, 1135 }; 1136 1137 static int __net_init ping_v4_proc_init_net(struct net *net) 1138 { 1139 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops, 1140 sizeof(struct ping_iter_state))) 1141 return -ENOMEM; 1142 return 0; 1143 } 1144 1145 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1146 { 1147 remove_proc_entry("icmp", net->proc_net); 1148 } 1149 1150 static struct pernet_operations ping_v4_net_ops = { 1151 .init = ping_v4_proc_init_net, 1152 .exit = ping_v4_proc_exit_net, 1153 }; 1154 1155 int __init ping_proc_init(void) 1156 { 1157 return register_pernet_subsys(&ping_v4_net_ops); 1158 } 1159 1160 void ping_proc_exit(void) 1161 { 1162 unregister_pernet_subsys(&ping_v4_net_ops); 1163 } 1164 1165 #endif 1166 1167 void __init ping_init(void) 1168 { 1169 int i; 1170 1171 for (i = 0; i < PING_HTABLE_SIZE; i++) 1172 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1173 rwlock_init(&ping_table.lock); 1174 } 1175