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 ipcm_init_sk(&ipc, inet); 743 744 if (msg->msg_controllen) { 745 err = ip_cmsg_send(sk, msg, &ipc, false); 746 if (unlikely(err)) { 747 kfree(ipc.opt); 748 return err; 749 } 750 if (ipc.opt) 751 free = 1; 752 } 753 if (!ipc.opt) { 754 struct ip_options_rcu *inet_opt; 755 756 rcu_read_lock(); 757 inet_opt = rcu_dereference(inet->inet_opt); 758 if (inet_opt) { 759 memcpy(&opt_copy, inet_opt, 760 sizeof(*inet_opt) + inet_opt->opt.optlen); 761 ipc.opt = &opt_copy.opt; 762 } 763 rcu_read_unlock(); 764 } 765 766 saddr = ipc.addr; 767 ipc.addr = faddr = daddr; 768 769 if (ipc.opt && ipc.opt->opt.srr) { 770 if (!daddr) { 771 err = -EINVAL; 772 goto out_free; 773 } 774 faddr = ipc.opt->opt.faddr; 775 } 776 tos = get_rttos(&ipc, inet); 777 if (sock_flag(sk, SOCK_LOCALROUTE) || 778 (msg->msg_flags & MSG_DONTROUTE) || 779 (ipc.opt && ipc.opt->opt.is_strictroute)) { 780 tos |= RTO_ONLINK; 781 } 782 783 if (ipv4_is_multicast(daddr)) { 784 if (!ipc.oif) 785 ipc.oif = inet->mc_index; 786 if (!saddr) 787 saddr = inet->mc_addr; 788 } else if (!ipc.oif) 789 ipc.oif = inet->uc_index; 790 791 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos, 792 RT_SCOPE_UNIVERSE, sk->sk_protocol, 793 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 794 sk->sk_uid); 795 796 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 797 rt = ip_route_output_flow(net, &fl4, sk); 798 if (IS_ERR(rt)) { 799 err = PTR_ERR(rt); 800 rt = NULL; 801 if (err == -ENETUNREACH) 802 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 803 goto out; 804 } 805 806 err = -EACCES; 807 if ((rt->rt_flags & RTCF_BROADCAST) && 808 !sock_flag(sk, SOCK_BROADCAST)) 809 goto out; 810 811 if (msg->msg_flags & MSG_CONFIRM) 812 goto do_confirm; 813 back_from_confirm: 814 815 if (!ipc.addr) 816 ipc.addr = fl4.daddr; 817 818 lock_sock(sk); 819 820 pfh.icmph.type = user_icmph.type; /* already checked */ 821 pfh.icmph.code = user_icmph.code; /* ditto */ 822 pfh.icmph.checksum = 0; 823 pfh.icmph.un.echo.id = inet->inet_sport; 824 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 825 pfh.msg = msg; 826 pfh.wcheck = 0; 827 pfh.family = AF_INET; 828 829 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 830 0, &ipc, &rt, msg->msg_flags); 831 if (err) 832 ip_flush_pending_frames(sk); 833 else 834 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 835 release_sock(sk); 836 837 out: 838 ip_rt_put(rt); 839 out_free: 840 if (free) 841 kfree(ipc.opt); 842 if (!err) { 843 icmp_out_count(sock_net(sk), user_icmph.type); 844 return len; 845 } 846 return err; 847 848 do_confirm: 849 if (msg->msg_flags & MSG_PROBE) 850 dst_confirm_neigh(&rt->dst, &fl4.daddr); 851 if (!(msg->msg_flags & MSG_PROBE) || len) 852 goto back_from_confirm; 853 err = 0; 854 goto out; 855 } 856 857 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 858 int flags, int *addr_len) 859 { 860 struct inet_sock *isk = inet_sk(sk); 861 int family = sk->sk_family; 862 struct sk_buff *skb; 863 int copied, err; 864 865 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 866 867 err = -EOPNOTSUPP; 868 if (flags & MSG_OOB) 869 goto out; 870 871 if (flags & MSG_ERRQUEUE) 872 return inet_recv_error(sk, msg, len, addr_len); 873 874 skb = skb_recv_datagram(sk, flags, noblock, &err); 875 if (!skb) 876 goto out; 877 878 copied = skb->len; 879 if (copied > len) { 880 msg->msg_flags |= MSG_TRUNC; 881 copied = len; 882 } 883 884 /* Don't bother checking the checksum */ 885 err = skb_copy_datagram_msg(skb, 0, msg, copied); 886 if (err) 887 goto done; 888 889 sock_recv_timestamp(msg, sk, skb); 890 891 /* Copy the address and add cmsg data. */ 892 if (family == AF_INET) { 893 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 894 895 if (sin) { 896 sin->sin_family = AF_INET; 897 sin->sin_port = 0 /* skb->h.uh->source */; 898 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 899 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 900 *addr_len = sizeof(*sin); 901 } 902 903 if (isk->cmsg_flags) 904 ip_cmsg_recv(msg, skb); 905 906 #if IS_ENABLED(CONFIG_IPV6) 907 } else if (family == AF_INET6) { 908 struct ipv6_pinfo *np = inet6_sk(sk); 909 struct ipv6hdr *ip6 = ipv6_hdr(skb); 910 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 911 912 if (sin6) { 913 sin6->sin6_family = AF_INET6; 914 sin6->sin6_port = 0; 915 sin6->sin6_addr = ip6->saddr; 916 sin6->sin6_flowinfo = 0; 917 if (np->sndflow) 918 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 919 sin6->sin6_scope_id = 920 ipv6_iface_scope_id(&sin6->sin6_addr, 921 inet6_iif(skb)); 922 *addr_len = sizeof(*sin6); 923 } 924 925 if (inet6_sk(sk)->rxopt.all) 926 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 927 if (skb->protocol == htons(ETH_P_IPV6) && 928 inet6_sk(sk)->rxopt.all) 929 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 930 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 931 ip_cmsg_recv(msg, skb); 932 #endif 933 } else { 934 BUG(); 935 } 936 937 err = copied; 938 939 done: 940 skb_free_datagram(sk, skb); 941 out: 942 pr_debug("ping_recvmsg -> %d\n", err); 943 return err; 944 } 945 EXPORT_SYMBOL_GPL(ping_recvmsg); 946 947 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 948 { 949 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 950 inet_sk(sk), inet_sk(sk)->inet_num, skb); 951 if (sock_queue_rcv_skb(sk, skb) < 0) { 952 kfree_skb(skb); 953 pr_debug("ping_queue_rcv_skb -> failed\n"); 954 return -1; 955 } 956 return 0; 957 } 958 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 959 960 961 /* 962 * All we need to do is get the socket. 963 */ 964 965 bool ping_rcv(struct sk_buff *skb) 966 { 967 struct sock *sk; 968 struct net *net = dev_net(skb->dev); 969 struct icmphdr *icmph = icmp_hdr(skb); 970 971 /* We assume the packet has already been checked by icmp_rcv */ 972 973 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 974 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 975 976 /* Push ICMP header back */ 977 skb_push(skb, skb->data - (u8 *)icmph); 978 979 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 980 if (sk) { 981 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 982 983 pr_debug("rcv on socket %p\n", sk); 984 if (skb2) 985 ping_queue_rcv_skb(sk, skb2); 986 sock_put(sk); 987 return true; 988 } 989 pr_debug("no socket, dropping\n"); 990 991 return false; 992 } 993 EXPORT_SYMBOL_GPL(ping_rcv); 994 995 struct proto ping_prot = { 996 .name = "PING", 997 .owner = THIS_MODULE, 998 .init = ping_init_sock, 999 .close = ping_close, 1000 .connect = ip4_datagram_connect, 1001 .disconnect = __udp_disconnect, 1002 .setsockopt = ip_setsockopt, 1003 .getsockopt = ip_getsockopt, 1004 .sendmsg = ping_v4_sendmsg, 1005 .recvmsg = ping_recvmsg, 1006 .bind = ping_bind, 1007 .backlog_rcv = ping_queue_rcv_skb, 1008 .release_cb = ip4_datagram_release_cb, 1009 .hash = ping_hash, 1010 .unhash = ping_unhash, 1011 .get_port = ping_get_port, 1012 .obj_size = sizeof(struct inet_sock), 1013 }; 1014 EXPORT_SYMBOL(ping_prot); 1015 1016 #ifdef CONFIG_PROC_FS 1017 1018 static struct sock *ping_get_first(struct seq_file *seq, int start) 1019 { 1020 struct sock *sk; 1021 struct ping_iter_state *state = seq->private; 1022 struct net *net = seq_file_net(seq); 1023 1024 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1025 ++state->bucket) { 1026 struct hlist_nulls_node *node; 1027 struct hlist_nulls_head *hslot; 1028 1029 hslot = &ping_table.hash[state->bucket]; 1030 1031 if (hlist_nulls_empty(hslot)) 1032 continue; 1033 1034 sk_nulls_for_each(sk, node, hslot) { 1035 if (net_eq(sock_net(sk), net) && 1036 sk->sk_family == state->family) 1037 goto found; 1038 } 1039 } 1040 sk = NULL; 1041 found: 1042 return sk; 1043 } 1044 1045 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1046 { 1047 struct ping_iter_state *state = seq->private; 1048 struct net *net = seq_file_net(seq); 1049 1050 do { 1051 sk = sk_nulls_next(sk); 1052 } while (sk && (!net_eq(sock_net(sk), net))); 1053 1054 if (!sk) 1055 return ping_get_first(seq, state->bucket + 1); 1056 return sk; 1057 } 1058 1059 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1060 { 1061 struct sock *sk = ping_get_first(seq, 0); 1062 1063 if (sk) 1064 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1065 --pos; 1066 return pos ? NULL : sk; 1067 } 1068 1069 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1070 __acquires(ping_table.lock) 1071 { 1072 struct ping_iter_state *state = seq->private; 1073 state->bucket = 0; 1074 state->family = family; 1075 1076 read_lock_bh(&ping_table.lock); 1077 1078 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1079 } 1080 EXPORT_SYMBOL_GPL(ping_seq_start); 1081 1082 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1083 { 1084 return ping_seq_start(seq, pos, AF_INET); 1085 } 1086 1087 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1088 { 1089 struct sock *sk; 1090 1091 if (v == SEQ_START_TOKEN) 1092 sk = ping_get_idx(seq, 0); 1093 else 1094 sk = ping_get_next(seq, v); 1095 1096 ++*pos; 1097 return sk; 1098 } 1099 EXPORT_SYMBOL_GPL(ping_seq_next); 1100 1101 void ping_seq_stop(struct seq_file *seq, void *v) 1102 __releases(ping_table.lock) 1103 { 1104 read_unlock_bh(&ping_table.lock); 1105 } 1106 EXPORT_SYMBOL_GPL(ping_seq_stop); 1107 1108 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1109 int bucket) 1110 { 1111 struct inet_sock *inet = inet_sk(sp); 1112 __be32 dest = inet->inet_daddr; 1113 __be32 src = inet->inet_rcv_saddr; 1114 __u16 destp = ntohs(inet->inet_dport); 1115 __u16 srcp = ntohs(inet->inet_sport); 1116 1117 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1118 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 1119 bucket, src, srcp, dest, destp, sp->sk_state, 1120 sk_wmem_alloc_get(sp), 1121 sk_rmem_alloc_get(sp), 1122 0, 0L, 0, 1123 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1124 0, sock_i_ino(sp), 1125 refcount_read(&sp->sk_refcnt), sp, 1126 atomic_read(&sp->sk_drops)); 1127 } 1128 1129 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1130 { 1131 seq_setwidth(seq, 127); 1132 if (v == SEQ_START_TOKEN) 1133 seq_puts(seq, " sl local_address rem_address st tx_queue " 1134 "rx_queue tr tm->when retrnsmt uid timeout " 1135 "inode ref pointer drops"); 1136 else { 1137 struct ping_iter_state *state = seq->private; 1138 1139 ping_v4_format_sock(v, seq, state->bucket); 1140 } 1141 seq_pad(seq, '\n'); 1142 return 0; 1143 } 1144 1145 static const struct seq_operations ping_v4_seq_ops = { 1146 .start = ping_v4_seq_start, 1147 .show = ping_v4_seq_show, 1148 .next = ping_seq_next, 1149 .stop = ping_seq_stop, 1150 }; 1151 1152 static int __net_init ping_v4_proc_init_net(struct net *net) 1153 { 1154 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops, 1155 sizeof(struct ping_iter_state))) 1156 return -ENOMEM; 1157 return 0; 1158 } 1159 1160 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1161 { 1162 remove_proc_entry("icmp", net->proc_net); 1163 } 1164 1165 static struct pernet_operations ping_v4_net_ops = { 1166 .init = ping_v4_proc_init_net, 1167 .exit = ping_v4_proc_exit_net, 1168 }; 1169 1170 int __init ping_proc_init(void) 1171 { 1172 return register_pernet_subsys(&ping_v4_net_ops); 1173 } 1174 1175 void ping_proc_exit(void) 1176 { 1177 unregister_pernet_subsys(&ping_v4_net_ops); 1178 } 1179 1180 #endif 1181 1182 void __init ping_init(void) 1183 { 1184 int i; 1185 1186 for (i = 0; i < PING_HTABLE_SIZE; i++) 1187 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1188 rwlock_init(&ping_table.lock); 1189 } 1190