1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * "Ping" sockets 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 * 13 * Based on ipv4/udp.c code. 14 * 15 * Authors: Vasiliy Kulikov / Openwall (for Linux 2.6), 16 * Pavel Kankovsky (for Linux 2.4.32) 17 * 18 * Pavel gave all rights to bugs to Vasiliy, 19 * none of the bugs are Pavel's now. 20 * 21 */ 22 23 #include <linux/uaccess.h> 24 #include <linux/types.h> 25 #include <linux/fcntl.h> 26 #include <linux/socket.h> 27 #include <linux/sockios.h> 28 #include <linux/in.h> 29 #include <linux/errno.h> 30 #include <linux/timer.h> 31 #include <linux/mm.h> 32 #include <linux/inet.h> 33 #include <linux/netdevice.h> 34 #include <net/snmp.h> 35 #include <net/ip.h> 36 #include <net/icmp.h> 37 #include <net/protocol.h> 38 #include <linux/skbuff.h> 39 #include <linux/proc_fs.h> 40 #include <linux/export.h> 41 #include <net/sock.h> 42 #include <net/ping.h> 43 #include <net/udp.h> 44 #include <net/route.h> 45 #include <net/inet_common.h> 46 #include <net/checksum.h> 47 48 #if IS_ENABLED(CONFIG_IPV6) 49 #include <linux/in6.h> 50 #include <linux/icmpv6.h> 51 #include <net/addrconf.h> 52 #include <net/ipv6.h> 53 #include <net/transp_v6.h> 54 #endif 55 56 struct ping_table { 57 struct hlist_nulls_head hash[PING_HTABLE_SIZE]; 58 rwlock_t lock; 59 }; 60 61 static struct ping_table ping_table; 62 struct pingv6_ops pingv6_ops; 63 EXPORT_SYMBOL_GPL(pingv6_ops); 64 65 static u16 ping_port_rover; 66 67 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask) 68 { 69 u32 res = (num + net_hash_mix(net)) & mask; 70 71 pr_debug("hash(%u) = %u\n", num, res); 72 return res; 73 } 74 EXPORT_SYMBOL_GPL(ping_hash); 75 76 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table, 77 struct net *net, unsigned int num) 78 { 79 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)]; 80 } 81 82 int ping_get_port(struct sock *sk, unsigned short ident) 83 { 84 struct hlist_nulls_node *node; 85 struct hlist_nulls_head *hlist; 86 struct inet_sock *isk, *isk2; 87 struct sock *sk2 = NULL; 88 89 isk = inet_sk(sk); 90 write_lock_bh(&ping_table.lock); 91 if (ident == 0) { 92 u32 i; 93 u16 result = ping_port_rover + 1; 94 95 for (i = 0; i < (1L << 16); i++, result++) { 96 if (!result) 97 result++; /* avoid zero */ 98 hlist = ping_hashslot(&ping_table, sock_net(sk), 99 result); 100 ping_portaddr_for_each_entry(sk2, node, hlist) { 101 isk2 = inet_sk(sk2); 102 103 if (isk2->inet_num == result) 104 goto next_port; 105 } 106 107 /* found */ 108 ping_port_rover = ident = result; 109 break; 110 next_port: 111 ; 112 } 113 if (i >= (1L << 16)) 114 goto fail; 115 } else { 116 hlist = ping_hashslot(&ping_table, sock_net(sk), ident); 117 ping_portaddr_for_each_entry(sk2, node, hlist) { 118 isk2 = inet_sk(sk2); 119 120 /* BUG? Why is this reuse and not reuseaddr? ping.c 121 * doesn't turn off SO_REUSEADDR, and it doesn't expect 122 * that other ping processes can steal its packets. 123 */ 124 if ((isk2->inet_num == ident) && 125 (sk2 != sk) && 126 (!sk2->sk_reuse || !sk->sk_reuse)) 127 goto fail; 128 } 129 } 130 131 pr_debug("found port/ident = %d\n", ident); 132 isk->inet_num = ident; 133 if (sk_unhashed(sk)) { 134 pr_debug("was not hashed\n"); 135 sock_hold(sk); 136 hlist_nulls_add_head(&sk->sk_nulls_node, hlist); 137 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 138 } 139 write_unlock_bh(&ping_table.lock); 140 return 0; 141 142 fail: 143 write_unlock_bh(&ping_table.lock); 144 return 1; 145 } 146 EXPORT_SYMBOL_GPL(ping_get_port); 147 148 int ping_hash(struct sock *sk) 149 { 150 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num); 151 BUG(); /* "Please do not press this button again." */ 152 153 return 0; 154 } 155 156 void ping_unhash(struct sock *sk) 157 { 158 struct inet_sock *isk = inet_sk(sk); 159 160 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); 161 write_lock_bh(&ping_table.lock); 162 if (sk_hashed(sk)) { 163 hlist_nulls_del(&sk->sk_nulls_node); 164 sk_nulls_node_init(&sk->sk_nulls_node); 165 sock_put(sk); 166 isk->inet_num = 0; 167 isk->inet_sport = 0; 168 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 169 } 170 write_unlock_bh(&ping_table.lock); 171 } 172 EXPORT_SYMBOL_GPL(ping_unhash); 173 174 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) 175 { 176 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); 177 struct sock *sk = NULL; 178 struct inet_sock *isk; 179 struct hlist_nulls_node *hnode; 180 int dif = skb->dev->ifindex; 181 182 if (skb->protocol == htons(ETH_P_IP)) { 183 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n", 184 (int)ident, &ip_hdr(skb)->daddr, dif); 185 #if IS_ENABLED(CONFIG_IPV6) 186 } else if (skb->protocol == htons(ETH_P_IPV6)) { 187 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", 188 (int)ident, &ipv6_hdr(skb)->daddr, dif); 189 #endif 190 } 191 192 read_lock_bh(&ping_table.lock); 193 194 ping_portaddr_for_each_entry(sk, hnode, hslot) { 195 isk = inet_sk(sk); 196 197 pr_debug("iterate\n"); 198 if (isk->inet_num != ident) 199 continue; 200 201 if (skb->protocol == htons(ETH_P_IP) && 202 sk->sk_family == AF_INET) { 203 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, 204 (int) isk->inet_num, &isk->inet_rcv_saddr, 205 sk->sk_bound_dev_if); 206 207 if (isk->inet_rcv_saddr && 208 isk->inet_rcv_saddr != ip_hdr(skb)->daddr) 209 continue; 210 #if IS_ENABLED(CONFIG_IPV6) 211 } else if (skb->protocol == htons(ETH_P_IPV6) && 212 sk->sk_family == AF_INET6) { 213 214 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, 215 (int) isk->inet_num, 216 &sk->sk_v6_rcv_saddr, 217 sk->sk_bound_dev_if); 218 219 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 220 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, 221 &ipv6_hdr(skb)->daddr)) 222 continue; 223 #endif 224 } else { 225 continue; 226 } 227 228 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) 229 continue; 230 231 sock_hold(sk); 232 goto exit; 233 } 234 235 sk = NULL; 236 exit: 237 read_unlock_bh(&ping_table.lock); 238 239 return sk; 240 } 241 242 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 243 kgid_t *high) 244 { 245 kgid_t *data = net->ipv4.ping_group_range.range; 246 unsigned int seq; 247 248 do { 249 seq = read_seqbegin(&net->ipv4.ping_group_range.lock); 250 251 *low = data[0]; 252 *high = data[1]; 253 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); 254 } 255 256 257 int ping_init_sock(struct sock *sk) 258 { 259 struct net *net = sock_net(sk); 260 kgid_t group = current_egid(); 261 struct group_info *group_info; 262 int i; 263 kgid_t low, high; 264 int ret = 0; 265 266 if (sk->sk_family == AF_INET6) 267 sk->sk_ipv6only = 1; 268 269 inet_get_ping_group_range_net(net, &low, &high); 270 if (gid_lte(low, group) && gid_lte(group, high)) 271 return 0; 272 273 group_info = get_current_groups(); 274 for (i = 0; i < group_info->ngroups; i++) { 275 kgid_t gid = group_info->gid[i]; 276 277 if (gid_lte(low, gid) && gid_lte(gid, high)) 278 goto out_release_group; 279 } 280 281 ret = -EACCES; 282 283 out_release_group: 284 put_group_info(group_info); 285 return ret; 286 } 287 EXPORT_SYMBOL_GPL(ping_init_sock); 288 289 void ping_close(struct sock *sk, long timeout) 290 { 291 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 292 inet_sk(sk), inet_sk(sk)->inet_num); 293 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt)); 294 295 sk_common_release(sk); 296 } 297 EXPORT_SYMBOL_GPL(ping_close); 298 299 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 300 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 301 struct sockaddr *uaddr, int addr_len) { 302 struct net *net = sock_net(sk); 303 if (sk->sk_family == AF_INET) { 304 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 305 int chk_addr_ret; 306 307 if (addr_len < sizeof(*addr)) 308 return -EINVAL; 309 310 if (addr->sin_family != AF_INET && 311 !(addr->sin_family == AF_UNSPEC && 312 addr->sin_addr.s_addr == htonl(INADDR_ANY))) 313 return -EAFNOSUPPORT; 314 315 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 316 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 317 318 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); 319 320 if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) 321 chk_addr_ret = RTN_LOCAL; 322 323 if ((net->ipv4.sysctl_ip_nonlocal_bind == 0 && 324 isk->freebind == 0 && isk->transparent == 0 && 325 chk_addr_ret != RTN_LOCAL) || 326 chk_addr_ret == RTN_MULTICAST || 327 chk_addr_ret == RTN_BROADCAST) 328 return -EADDRNOTAVAIL; 329 330 #if IS_ENABLED(CONFIG_IPV6) 331 } else if (sk->sk_family == AF_INET6) { 332 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 333 int addr_type, scoped, has_addr; 334 struct net_device *dev = NULL; 335 336 if (addr_len < sizeof(*addr)) 337 return -EINVAL; 338 339 if (addr->sin6_family != AF_INET6) 340 return -EAFNOSUPPORT; 341 342 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 343 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 344 345 addr_type = ipv6_addr_type(&addr->sin6_addr); 346 scoped = __ipv6_addr_needs_scope_id(addr_type); 347 if ((addr_type != IPV6_ADDR_ANY && 348 !(addr_type & IPV6_ADDR_UNICAST)) || 349 (scoped && !addr->sin6_scope_id)) 350 return -EINVAL; 351 352 rcu_read_lock(); 353 if (addr->sin6_scope_id) { 354 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 355 if (!dev) { 356 rcu_read_unlock(); 357 return -ENODEV; 358 } 359 } 360 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 361 scoped); 362 rcu_read_unlock(); 363 364 if (!(net->ipv6.sysctl.ip_nonlocal_bind || 365 isk->freebind || isk->transparent || has_addr || 366 addr_type == IPV6_ADDR_ANY)) 367 return -EADDRNOTAVAIL; 368 369 if (scoped) 370 sk->sk_bound_dev_if = addr->sin6_scope_id; 371 #endif 372 } else { 373 return -EAFNOSUPPORT; 374 } 375 return 0; 376 } 377 378 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 379 { 380 if (saddr->sa_family == AF_INET) { 381 struct inet_sock *isk = inet_sk(sk); 382 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 383 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 384 #if IS_ENABLED(CONFIG_IPV6) 385 } else if (saddr->sa_family == AF_INET6) { 386 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 387 struct ipv6_pinfo *np = inet6_sk(sk); 388 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 389 #endif 390 } 391 } 392 393 static void ping_clear_saddr(struct sock *sk, int dif) 394 { 395 sk->sk_bound_dev_if = dif; 396 if (sk->sk_family == AF_INET) { 397 struct inet_sock *isk = inet_sk(sk); 398 isk->inet_rcv_saddr = isk->inet_saddr = 0; 399 #if IS_ENABLED(CONFIG_IPV6) 400 } else if (sk->sk_family == AF_INET6) { 401 struct ipv6_pinfo *np = inet6_sk(sk); 402 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 403 memset(&np->saddr, 0, sizeof(np->saddr)); 404 #endif 405 } 406 } 407 /* 408 * We need our own bind because there are no privileged id's == local ports. 409 * Moreover, we don't allow binding to multi- and broadcast addresses. 410 */ 411 412 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 413 { 414 struct inet_sock *isk = inet_sk(sk); 415 unsigned short snum; 416 int err; 417 int dif = sk->sk_bound_dev_if; 418 419 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 420 if (err) 421 return err; 422 423 lock_sock(sk); 424 425 err = -EINVAL; 426 if (isk->inet_num != 0) 427 goto out; 428 429 err = -EADDRINUSE; 430 ping_set_saddr(sk, uaddr); 431 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 432 if (ping_get_port(sk, snum) != 0) { 433 ping_clear_saddr(sk, dif); 434 goto out; 435 } 436 437 pr_debug("after bind(): num = %hu, dif = %d\n", 438 isk->inet_num, 439 sk->sk_bound_dev_if); 440 441 err = 0; 442 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 443 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 444 #if IS_ENABLED(CONFIG_IPV6) 445 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 446 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 447 #endif 448 449 if (snum) 450 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 451 isk->inet_sport = htons(isk->inet_num); 452 isk->inet_daddr = 0; 453 isk->inet_dport = 0; 454 455 #if IS_ENABLED(CONFIG_IPV6) 456 if (sk->sk_family == AF_INET6) 457 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 458 #endif 459 460 sk_dst_reset(sk); 461 out: 462 release_sock(sk); 463 pr_debug("ping_v4_bind -> %d\n", err); 464 return err; 465 } 466 EXPORT_SYMBOL_GPL(ping_bind); 467 468 /* 469 * Is this a supported type of ICMP message? 470 */ 471 472 static inline int ping_supported(int family, int type, int code) 473 { 474 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 475 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0); 476 } 477 478 /* 479 * This routine is called by the ICMP module when it gets some 480 * sort of error condition. 481 */ 482 483 void ping_err(struct sk_buff *skb, int offset, u32 info) 484 { 485 int family; 486 struct icmphdr *icmph; 487 struct inet_sock *inet_sock; 488 int type; 489 int code; 490 struct net *net = dev_net(skb->dev); 491 struct sock *sk; 492 int harderr; 493 int err; 494 495 if (skb->protocol == htons(ETH_P_IP)) { 496 family = AF_INET; 497 type = icmp_hdr(skb)->type; 498 code = icmp_hdr(skb)->code; 499 icmph = (struct icmphdr *)(skb->data + offset); 500 } else if (skb->protocol == htons(ETH_P_IPV6)) { 501 family = AF_INET6; 502 type = icmp6_hdr(skb)->icmp6_type; 503 code = icmp6_hdr(skb)->icmp6_code; 504 icmph = (struct icmphdr *) (skb->data + offset); 505 } else { 506 BUG(); 507 } 508 509 /* We assume the packet has already been checked by icmp_unreach */ 510 511 if (!ping_supported(family, icmph->type, icmph->code)) 512 return; 513 514 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 515 skb->protocol, type, code, ntohs(icmph->un.echo.id), 516 ntohs(icmph->un.echo.sequence)); 517 518 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 519 if (!sk) { 520 pr_debug("no socket, dropping\n"); 521 return; /* No socket for error */ 522 } 523 pr_debug("err on socket %p\n", sk); 524 525 err = 0; 526 harderr = 0; 527 inet_sock = inet_sk(sk); 528 529 if (skb->protocol == htons(ETH_P_IP)) { 530 switch (type) { 531 default: 532 case ICMP_TIME_EXCEEDED: 533 err = EHOSTUNREACH; 534 break; 535 case ICMP_SOURCE_QUENCH: 536 /* This is not a real error but ping wants to see it. 537 * Report it with some fake errno. 538 */ 539 err = EREMOTEIO; 540 break; 541 case ICMP_PARAMETERPROB: 542 err = EPROTO; 543 harderr = 1; 544 break; 545 case ICMP_DEST_UNREACH: 546 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 547 ipv4_sk_update_pmtu(skb, sk, info); 548 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 549 err = EMSGSIZE; 550 harderr = 1; 551 break; 552 } 553 goto out; 554 } 555 err = EHOSTUNREACH; 556 if (code <= NR_ICMP_UNREACH) { 557 harderr = icmp_err_convert[code].fatal; 558 err = icmp_err_convert[code].errno; 559 } 560 break; 561 case ICMP_REDIRECT: 562 /* See ICMP_SOURCE_QUENCH */ 563 ipv4_sk_redirect(skb, sk); 564 err = EREMOTEIO; 565 break; 566 } 567 #if IS_ENABLED(CONFIG_IPV6) 568 } else if (skb->protocol == htons(ETH_P_IPV6)) { 569 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 570 #endif 571 } 572 573 /* 574 * RFC1122: OK. Passes ICMP errors back to application, as per 575 * 4.1.3.3. 576 */ 577 if ((family == AF_INET && !inet_sock->recverr) || 578 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 579 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 580 goto out; 581 } else { 582 if (family == AF_INET) { 583 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 584 info, (u8 *)icmph); 585 #if IS_ENABLED(CONFIG_IPV6) 586 } else if (family == AF_INET6) { 587 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 588 info, (u8 *)icmph); 589 #endif 590 } 591 } 592 sk->sk_err = err; 593 sk->sk_error_report(sk); 594 out: 595 sock_put(sk); 596 } 597 EXPORT_SYMBOL_GPL(ping_err); 598 599 /* 600 * Copy and checksum an ICMP Echo packet from user space into a buffer 601 * starting from the payload. 602 */ 603 604 int ping_getfrag(void *from, char *to, 605 int offset, int fraglen, int odd, struct sk_buff *skb) 606 { 607 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 608 609 if (offset == 0) { 610 fraglen -= sizeof(struct icmphdr); 611 if (fraglen < 0) 612 BUG(); 613 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), 614 fraglen, &pfh->wcheck, 615 &pfh->msg->msg_iter)) 616 return -EFAULT; 617 } else if (offset < sizeof(struct icmphdr)) { 618 BUG(); 619 } else { 620 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, 621 &pfh->msg->msg_iter)) 622 return -EFAULT; 623 } 624 625 #if IS_ENABLED(CONFIG_IPV6) 626 /* For IPv6, checksum each skb as we go along, as expected by 627 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 628 * wcheck, it will be finalized in ping_v4_push_pending_frames. 629 */ 630 if (pfh->family == AF_INET6) { 631 skb->csum = pfh->wcheck; 632 skb->ip_summed = CHECKSUM_NONE; 633 pfh->wcheck = 0; 634 } 635 #endif 636 637 return 0; 638 } 639 EXPORT_SYMBOL_GPL(ping_getfrag); 640 641 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 642 struct flowi4 *fl4) 643 { 644 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 645 646 if (!skb) 647 return 0; 648 pfh->wcheck = csum_partial((char *)&pfh->icmph, 649 sizeof(struct icmphdr), pfh->wcheck); 650 pfh->icmph.checksum = csum_fold(pfh->wcheck); 651 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 652 skb->ip_summed = CHECKSUM_NONE; 653 return ip_push_pending_frames(sk, fl4); 654 } 655 656 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 657 void *user_icmph, size_t icmph_len) { 658 u8 type, code; 659 660 if (len > 0xFFFF) 661 return -EMSGSIZE; 662 663 /* Must have at least a full ICMP header. */ 664 if (len < icmph_len) 665 return -EINVAL; 666 667 /* 668 * Check the flags. 669 */ 670 671 /* Mirror BSD error message compatibility */ 672 if (msg->msg_flags & MSG_OOB) 673 return -EOPNOTSUPP; 674 675 /* 676 * Fetch the ICMP header provided by the userland. 677 * iovec is modified! The ICMP header is consumed. 678 */ 679 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 680 return -EFAULT; 681 682 if (family == AF_INET) { 683 type = ((struct icmphdr *) user_icmph)->type; 684 code = ((struct icmphdr *) user_icmph)->code; 685 #if IS_ENABLED(CONFIG_IPV6) 686 } else if (family == AF_INET6) { 687 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 688 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 689 #endif 690 } else { 691 BUG(); 692 } 693 694 if (!ping_supported(family, type, code)) 695 return -EINVAL; 696 697 return 0; 698 } 699 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 700 701 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 702 { 703 struct net *net = sock_net(sk); 704 struct flowi4 fl4; 705 struct inet_sock *inet = inet_sk(sk); 706 struct ipcm_cookie ipc; 707 struct icmphdr user_icmph; 708 struct pingfakehdr pfh; 709 struct rtable *rt = NULL; 710 struct ip_options_data opt_copy; 711 int free = 0; 712 __be32 saddr, daddr, faddr; 713 u8 tos; 714 int err; 715 716 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 717 718 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 719 sizeof(user_icmph)); 720 if (err) 721 return err; 722 723 /* 724 * Get and verify the address. 725 */ 726 727 if (msg->msg_name) { 728 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 729 if (msg->msg_namelen < sizeof(*usin)) 730 return -EINVAL; 731 if (usin->sin_family != AF_INET) 732 return -EAFNOSUPPORT; 733 daddr = usin->sin_addr.s_addr; 734 /* no remote port */ 735 } else { 736 if (sk->sk_state != TCP_ESTABLISHED) 737 return -EDESTADDRREQ; 738 daddr = inet->inet_daddr; 739 /* no remote port */ 740 } 741 742 ipc.sockc.tsflags = sk->sk_tsflags; 743 ipc.addr = inet->inet_saddr; 744 ipc.opt = NULL; 745 ipc.oif = sk->sk_bound_dev_if; 746 ipc.tx_flags = 0; 747 ipc.ttl = 0; 748 ipc.tos = -1; 749 ipc.sockc.transmit_time = 0; 750 751 if (msg->msg_controllen) { 752 err = ip_cmsg_send(sk, msg, &ipc, false); 753 if (unlikely(err)) { 754 kfree(ipc.opt); 755 return err; 756 } 757 if (ipc.opt) 758 free = 1; 759 } 760 if (!ipc.opt) { 761 struct ip_options_rcu *inet_opt; 762 763 rcu_read_lock(); 764 inet_opt = rcu_dereference(inet->inet_opt); 765 if (inet_opt) { 766 memcpy(&opt_copy, inet_opt, 767 sizeof(*inet_opt) + inet_opt->opt.optlen); 768 ipc.opt = &opt_copy.opt; 769 } 770 rcu_read_unlock(); 771 } 772 773 sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags); 774 775 saddr = ipc.addr; 776 ipc.addr = faddr = daddr; 777 778 if (ipc.opt && ipc.opt->opt.srr) { 779 if (!daddr) { 780 err = -EINVAL; 781 goto out_free; 782 } 783 faddr = ipc.opt->opt.faddr; 784 } 785 tos = get_rttos(&ipc, inet); 786 if (sock_flag(sk, SOCK_LOCALROUTE) || 787 (msg->msg_flags & MSG_DONTROUTE) || 788 (ipc.opt && ipc.opt->opt.is_strictroute)) { 789 tos |= RTO_ONLINK; 790 } 791 792 if (ipv4_is_multicast(daddr)) { 793 if (!ipc.oif) 794 ipc.oif = inet->mc_index; 795 if (!saddr) 796 saddr = inet->mc_addr; 797 } else if (!ipc.oif) 798 ipc.oif = inet->uc_index; 799 800 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos, 801 RT_SCOPE_UNIVERSE, sk->sk_protocol, 802 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 803 sk->sk_uid); 804 805 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 806 rt = ip_route_output_flow(net, &fl4, sk); 807 if (IS_ERR(rt)) { 808 err = PTR_ERR(rt); 809 rt = NULL; 810 if (err == -ENETUNREACH) 811 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 812 goto out; 813 } 814 815 err = -EACCES; 816 if ((rt->rt_flags & RTCF_BROADCAST) && 817 !sock_flag(sk, SOCK_BROADCAST)) 818 goto out; 819 820 if (msg->msg_flags & MSG_CONFIRM) 821 goto do_confirm; 822 back_from_confirm: 823 824 if (!ipc.addr) 825 ipc.addr = fl4.daddr; 826 827 lock_sock(sk); 828 829 pfh.icmph.type = user_icmph.type; /* already checked */ 830 pfh.icmph.code = user_icmph.code; /* ditto */ 831 pfh.icmph.checksum = 0; 832 pfh.icmph.un.echo.id = inet->inet_sport; 833 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 834 pfh.msg = msg; 835 pfh.wcheck = 0; 836 pfh.family = AF_INET; 837 838 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 839 0, &ipc, &rt, msg->msg_flags); 840 if (err) 841 ip_flush_pending_frames(sk); 842 else 843 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 844 release_sock(sk); 845 846 out: 847 ip_rt_put(rt); 848 out_free: 849 if (free) 850 kfree(ipc.opt); 851 if (!err) { 852 icmp_out_count(sock_net(sk), user_icmph.type); 853 return len; 854 } 855 return err; 856 857 do_confirm: 858 if (msg->msg_flags & MSG_PROBE) 859 dst_confirm_neigh(&rt->dst, &fl4.daddr); 860 if (!(msg->msg_flags & MSG_PROBE) || len) 861 goto back_from_confirm; 862 err = 0; 863 goto out; 864 } 865 866 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 867 int flags, int *addr_len) 868 { 869 struct inet_sock *isk = inet_sk(sk); 870 int family = sk->sk_family; 871 struct sk_buff *skb; 872 int copied, err; 873 874 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 875 876 err = -EOPNOTSUPP; 877 if (flags & MSG_OOB) 878 goto out; 879 880 if (flags & MSG_ERRQUEUE) 881 return inet_recv_error(sk, msg, len, addr_len); 882 883 skb = skb_recv_datagram(sk, flags, noblock, &err); 884 if (!skb) 885 goto out; 886 887 copied = skb->len; 888 if (copied > len) { 889 msg->msg_flags |= MSG_TRUNC; 890 copied = len; 891 } 892 893 /* Don't bother checking the checksum */ 894 err = skb_copy_datagram_msg(skb, 0, msg, copied); 895 if (err) 896 goto done; 897 898 sock_recv_timestamp(msg, sk, skb); 899 900 /* Copy the address and add cmsg data. */ 901 if (family == AF_INET) { 902 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 903 904 if (sin) { 905 sin->sin_family = AF_INET; 906 sin->sin_port = 0 /* skb->h.uh->source */; 907 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 908 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 909 *addr_len = sizeof(*sin); 910 } 911 912 if (isk->cmsg_flags) 913 ip_cmsg_recv(msg, skb); 914 915 #if IS_ENABLED(CONFIG_IPV6) 916 } else if (family == AF_INET6) { 917 struct ipv6_pinfo *np = inet6_sk(sk); 918 struct ipv6hdr *ip6 = ipv6_hdr(skb); 919 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 920 921 if (sin6) { 922 sin6->sin6_family = AF_INET6; 923 sin6->sin6_port = 0; 924 sin6->sin6_addr = ip6->saddr; 925 sin6->sin6_flowinfo = 0; 926 if (np->sndflow) 927 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 928 sin6->sin6_scope_id = 929 ipv6_iface_scope_id(&sin6->sin6_addr, 930 inet6_iif(skb)); 931 *addr_len = sizeof(*sin6); 932 } 933 934 if (inet6_sk(sk)->rxopt.all) 935 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 936 if (skb->protocol == htons(ETH_P_IPV6) && 937 inet6_sk(sk)->rxopt.all) 938 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 939 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 940 ip_cmsg_recv(msg, skb); 941 #endif 942 } else { 943 BUG(); 944 } 945 946 err = copied; 947 948 done: 949 skb_free_datagram(sk, skb); 950 out: 951 pr_debug("ping_recvmsg -> %d\n", err); 952 return err; 953 } 954 EXPORT_SYMBOL_GPL(ping_recvmsg); 955 956 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 957 { 958 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 959 inet_sk(sk), inet_sk(sk)->inet_num, skb); 960 if (sock_queue_rcv_skb(sk, skb) < 0) { 961 kfree_skb(skb); 962 pr_debug("ping_queue_rcv_skb -> failed\n"); 963 return -1; 964 } 965 return 0; 966 } 967 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 968 969 970 /* 971 * All we need to do is get the socket. 972 */ 973 974 bool ping_rcv(struct sk_buff *skb) 975 { 976 struct sock *sk; 977 struct net *net = dev_net(skb->dev); 978 struct icmphdr *icmph = icmp_hdr(skb); 979 980 /* We assume the packet has already been checked by icmp_rcv */ 981 982 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 983 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 984 985 /* Push ICMP header back */ 986 skb_push(skb, skb->data - (u8 *)icmph); 987 988 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 989 if (sk) { 990 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 991 992 pr_debug("rcv on socket %p\n", sk); 993 if (skb2) 994 ping_queue_rcv_skb(sk, skb2); 995 sock_put(sk); 996 return true; 997 } 998 pr_debug("no socket, dropping\n"); 999 1000 return false; 1001 } 1002 EXPORT_SYMBOL_GPL(ping_rcv); 1003 1004 struct proto ping_prot = { 1005 .name = "PING", 1006 .owner = THIS_MODULE, 1007 .init = ping_init_sock, 1008 .close = ping_close, 1009 .connect = ip4_datagram_connect, 1010 .disconnect = __udp_disconnect, 1011 .setsockopt = ip_setsockopt, 1012 .getsockopt = ip_getsockopt, 1013 .sendmsg = ping_v4_sendmsg, 1014 .recvmsg = ping_recvmsg, 1015 .bind = ping_bind, 1016 .backlog_rcv = ping_queue_rcv_skb, 1017 .release_cb = ip4_datagram_release_cb, 1018 .hash = ping_hash, 1019 .unhash = ping_unhash, 1020 .get_port = ping_get_port, 1021 .obj_size = sizeof(struct inet_sock), 1022 }; 1023 EXPORT_SYMBOL(ping_prot); 1024 1025 #ifdef CONFIG_PROC_FS 1026 1027 static struct sock *ping_get_first(struct seq_file *seq, int start) 1028 { 1029 struct sock *sk; 1030 struct ping_iter_state *state = seq->private; 1031 struct net *net = seq_file_net(seq); 1032 1033 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1034 ++state->bucket) { 1035 struct hlist_nulls_node *node; 1036 struct hlist_nulls_head *hslot; 1037 1038 hslot = &ping_table.hash[state->bucket]; 1039 1040 if (hlist_nulls_empty(hslot)) 1041 continue; 1042 1043 sk_nulls_for_each(sk, node, hslot) { 1044 if (net_eq(sock_net(sk), net) && 1045 sk->sk_family == state->family) 1046 goto found; 1047 } 1048 } 1049 sk = NULL; 1050 found: 1051 return sk; 1052 } 1053 1054 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1055 { 1056 struct ping_iter_state *state = seq->private; 1057 struct net *net = seq_file_net(seq); 1058 1059 do { 1060 sk = sk_nulls_next(sk); 1061 } while (sk && (!net_eq(sock_net(sk), net))); 1062 1063 if (!sk) 1064 return ping_get_first(seq, state->bucket + 1); 1065 return sk; 1066 } 1067 1068 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1069 { 1070 struct sock *sk = ping_get_first(seq, 0); 1071 1072 if (sk) 1073 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1074 --pos; 1075 return pos ? NULL : sk; 1076 } 1077 1078 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1079 __acquires(ping_table.lock) 1080 { 1081 struct ping_iter_state *state = seq->private; 1082 state->bucket = 0; 1083 state->family = family; 1084 1085 read_lock_bh(&ping_table.lock); 1086 1087 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1088 } 1089 EXPORT_SYMBOL_GPL(ping_seq_start); 1090 1091 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1092 { 1093 return ping_seq_start(seq, pos, AF_INET); 1094 } 1095 1096 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1097 { 1098 struct sock *sk; 1099 1100 if (v == SEQ_START_TOKEN) 1101 sk = ping_get_idx(seq, 0); 1102 else 1103 sk = ping_get_next(seq, v); 1104 1105 ++*pos; 1106 return sk; 1107 } 1108 EXPORT_SYMBOL_GPL(ping_seq_next); 1109 1110 void ping_seq_stop(struct seq_file *seq, void *v) 1111 __releases(ping_table.lock) 1112 { 1113 read_unlock_bh(&ping_table.lock); 1114 } 1115 EXPORT_SYMBOL_GPL(ping_seq_stop); 1116 1117 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1118 int bucket) 1119 { 1120 struct inet_sock *inet = inet_sk(sp); 1121 __be32 dest = inet->inet_daddr; 1122 __be32 src = inet->inet_rcv_saddr; 1123 __u16 destp = ntohs(inet->inet_dport); 1124 __u16 srcp = ntohs(inet->inet_sport); 1125 1126 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1127 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 1128 bucket, src, srcp, dest, destp, sp->sk_state, 1129 sk_wmem_alloc_get(sp), 1130 sk_rmem_alloc_get(sp), 1131 0, 0L, 0, 1132 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1133 0, sock_i_ino(sp), 1134 refcount_read(&sp->sk_refcnt), sp, 1135 atomic_read(&sp->sk_drops)); 1136 } 1137 1138 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1139 { 1140 seq_setwidth(seq, 127); 1141 if (v == SEQ_START_TOKEN) 1142 seq_puts(seq, " sl local_address rem_address st tx_queue " 1143 "rx_queue tr tm->when retrnsmt uid timeout " 1144 "inode ref pointer drops"); 1145 else { 1146 struct ping_iter_state *state = seq->private; 1147 1148 ping_v4_format_sock(v, seq, state->bucket); 1149 } 1150 seq_pad(seq, '\n'); 1151 return 0; 1152 } 1153 1154 static const struct seq_operations ping_v4_seq_ops = { 1155 .start = ping_v4_seq_start, 1156 .show = ping_v4_seq_show, 1157 .next = ping_seq_next, 1158 .stop = ping_seq_stop, 1159 }; 1160 1161 static int __net_init ping_v4_proc_init_net(struct net *net) 1162 { 1163 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops, 1164 sizeof(struct ping_iter_state))) 1165 return -ENOMEM; 1166 return 0; 1167 } 1168 1169 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1170 { 1171 remove_proc_entry("icmp", net->proc_net); 1172 } 1173 1174 static struct pernet_operations ping_v4_net_ops = { 1175 .init = ping_v4_proc_init_net, 1176 .exit = ping_v4_proc_exit_net, 1177 }; 1178 1179 int __init ping_proc_init(void) 1180 { 1181 return register_pernet_subsys(&ping_v4_net_ops); 1182 } 1183 1184 void ping_proc_exit(void) 1185 { 1186 unregister_pernet_subsys(&ping_v4_net_ops); 1187 } 1188 1189 #endif 1190 1191 void __init ping_init(void) 1192 { 1193 int i; 1194 1195 for (i = 0; i < PING_HTABLE_SIZE; i++) 1196 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1197 rwlock_init(&ping_table.lock); 1198 } 1199