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 int ping_hashfn(struct net *net, unsigned int num, unsigned int mask) 68 { 69 int res = (num + net_hash_mix(net)) & mask; 70 71 pr_debug("hash(%d) = %d\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 void 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 } 153 154 void ping_unhash(struct sock *sk) 155 { 156 struct inet_sock *isk = inet_sk(sk); 157 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); 158 if (sk_hashed(sk)) { 159 write_lock_bh(&ping_table.lock); 160 hlist_nulls_del(&sk->sk_nulls_node); 161 sock_put(sk); 162 isk->inet_num = 0; 163 isk->inet_sport = 0; 164 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 165 write_unlock_bh(&ping_table.lock); 166 } 167 } 168 EXPORT_SYMBOL_GPL(ping_unhash); 169 170 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) 171 { 172 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); 173 struct sock *sk = NULL; 174 struct inet_sock *isk; 175 struct hlist_nulls_node *hnode; 176 int dif = skb->dev->ifindex; 177 178 if (skb->protocol == htons(ETH_P_IP)) { 179 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n", 180 (int)ident, &ip_hdr(skb)->daddr, dif); 181 #if IS_ENABLED(CONFIG_IPV6) 182 } else if (skb->protocol == htons(ETH_P_IPV6)) { 183 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", 184 (int)ident, &ipv6_hdr(skb)->daddr, dif); 185 #endif 186 } 187 188 read_lock_bh(&ping_table.lock); 189 190 ping_portaddr_for_each_entry(sk, hnode, hslot) { 191 isk = inet_sk(sk); 192 193 pr_debug("iterate\n"); 194 if (isk->inet_num != ident) 195 continue; 196 197 if (skb->protocol == htons(ETH_P_IP) && 198 sk->sk_family == AF_INET) { 199 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, 200 (int) isk->inet_num, &isk->inet_rcv_saddr, 201 sk->sk_bound_dev_if); 202 203 if (isk->inet_rcv_saddr && 204 isk->inet_rcv_saddr != ip_hdr(skb)->daddr) 205 continue; 206 #if IS_ENABLED(CONFIG_IPV6) 207 } else if (skb->protocol == htons(ETH_P_IPV6) && 208 sk->sk_family == AF_INET6) { 209 210 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, 211 (int) isk->inet_num, 212 &sk->sk_v6_rcv_saddr, 213 sk->sk_bound_dev_if); 214 215 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 216 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, 217 &ipv6_hdr(skb)->daddr)) 218 continue; 219 #endif 220 } else { 221 continue; 222 } 223 224 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) 225 continue; 226 227 sock_hold(sk); 228 goto exit; 229 } 230 231 sk = NULL; 232 exit: 233 read_unlock_bh(&ping_table.lock); 234 235 return sk; 236 } 237 238 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 239 kgid_t *high) 240 { 241 kgid_t *data = net->ipv4.ping_group_range.range; 242 unsigned int seq; 243 244 do { 245 seq = read_seqbegin(&net->ipv4.ping_group_range.lock); 246 247 *low = data[0]; 248 *high = data[1]; 249 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); 250 } 251 252 253 int ping_init_sock(struct sock *sk) 254 { 255 struct net *net = sock_net(sk); 256 kgid_t group = current_egid(); 257 struct group_info *group_info; 258 int i, j, count; 259 kgid_t low, high; 260 int ret = 0; 261 262 inet_get_ping_group_range_net(net, &low, &high); 263 if (gid_lte(low, group) && gid_lte(group, high)) 264 return 0; 265 266 group_info = get_current_groups(); 267 count = group_info->ngroups; 268 for (i = 0; i < group_info->nblocks; i++) { 269 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count); 270 for (j = 0; j < cp_count; j++) { 271 kgid_t gid = group_info->blocks[i][j]; 272 if (gid_lte(low, gid) && gid_lte(gid, high)) 273 goto out_release_group; 274 } 275 276 count -= cp_count; 277 } 278 279 ret = -EACCES; 280 281 out_release_group: 282 put_group_info(group_info); 283 return ret; 284 } 285 EXPORT_SYMBOL_GPL(ping_init_sock); 286 287 void ping_close(struct sock *sk, long timeout) 288 { 289 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 290 inet_sk(sk), inet_sk(sk)->inet_num); 291 pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter); 292 293 sk_common_release(sk); 294 } 295 EXPORT_SYMBOL_GPL(ping_close); 296 297 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 298 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 299 struct sockaddr *uaddr, int addr_len) { 300 struct net *net = sock_net(sk); 301 if (sk->sk_family == AF_INET) { 302 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 303 int chk_addr_ret; 304 305 if (addr_len < sizeof(*addr)) 306 return -EINVAL; 307 308 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 309 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 310 311 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); 312 313 if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) 314 chk_addr_ret = RTN_LOCAL; 315 316 if ((net->ipv4.sysctl_ip_nonlocal_bind == 0 && 317 isk->freebind == 0 && isk->transparent == 0 && 318 chk_addr_ret != RTN_LOCAL) || 319 chk_addr_ret == RTN_MULTICAST || 320 chk_addr_ret == RTN_BROADCAST) 321 return -EADDRNOTAVAIL; 322 323 #if IS_ENABLED(CONFIG_IPV6) 324 } else if (sk->sk_family == AF_INET6) { 325 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 326 int addr_type, scoped, has_addr; 327 struct net_device *dev = NULL; 328 329 if (addr_len < sizeof(*addr)) 330 return -EINVAL; 331 332 if (addr->sin6_family != AF_INET6) 333 return -EINVAL; 334 335 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 336 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 337 338 addr_type = ipv6_addr_type(&addr->sin6_addr); 339 scoped = __ipv6_addr_needs_scope_id(addr_type); 340 if ((addr_type != IPV6_ADDR_ANY && 341 !(addr_type & IPV6_ADDR_UNICAST)) || 342 (scoped && !addr->sin6_scope_id)) 343 return -EINVAL; 344 345 rcu_read_lock(); 346 if (addr->sin6_scope_id) { 347 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 348 if (!dev) { 349 rcu_read_unlock(); 350 return -ENODEV; 351 } 352 } 353 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 354 scoped); 355 rcu_read_unlock(); 356 357 if (!(isk->freebind || isk->transparent || has_addr || 358 addr_type == IPV6_ADDR_ANY)) 359 return -EADDRNOTAVAIL; 360 361 if (scoped) 362 sk->sk_bound_dev_if = addr->sin6_scope_id; 363 #endif 364 } else { 365 return -EAFNOSUPPORT; 366 } 367 return 0; 368 } 369 370 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 371 { 372 if (saddr->sa_family == AF_INET) { 373 struct inet_sock *isk = inet_sk(sk); 374 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 375 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 376 #if IS_ENABLED(CONFIG_IPV6) 377 } else if (saddr->sa_family == AF_INET6) { 378 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 379 struct ipv6_pinfo *np = inet6_sk(sk); 380 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 381 #endif 382 } 383 } 384 385 static void ping_clear_saddr(struct sock *sk, int dif) 386 { 387 sk->sk_bound_dev_if = dif; 388 if (sk->sk_family == AF_INET) { 389 struct inet_sock *isk = inet_sk(sk); 390 isk->inet_rcv_saddr = isk->inet_saddr = 0; 391 #if IS_ENABLED(CONFIG_IPV6) 392 } else if (sk->sk_family == AF_INET6) { 393 struct ipv6_pinfo *np = inet6_sk(sk); 394 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 395 memset(&np->saddr, 0, sizeof(np->saddr)); 396 #endif 397 } 398 } 399 /* 400 * We need our own bind because there are no privileged id's == local ports. 401 * Moreover, we don't allow binding to multi- and broadcast addresses. 402 */ 403 404 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 405 { 406 struct inet_sock *isk = inet_sk(sk); 407 unsigned short snum; 408 int err; 409 int dif = sk->sk_bound_dev_if; 410 411 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 412 if (err) 413 return err; 414 415 lock_sock(sk); 416 417 err = -EINVAL; 418 if (isk->inet_num != 0) 419 goto out; 420 421 err = -EADDRINUSE; 422 ping_set_saddr(sk, uaddr); 423 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 424 if (ping_get_port(sk, snum) != 0) { 425 ping_clear_saddr(sk, dif); 426 goto out; 427 } 428 429 pr_debug("after bind(): num = %d, dif = %d\n", 430 (int)isk->inet_num, 431 (int)sk->sk_bound_dev_if); 432 433 err = 0; 434 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 435 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 436 #if IS_ENABLED(CONFIG_IPV6) 437 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 438 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 439 #endif 440 441 if (snum) 442 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 443 isk->inet_sport = htons(isk->inet_num); 444 isk->inet_daddr = 0; 445 isk->inet_dport = 0; 446 447 #if IS_ENABLED(CONFIG_IPV6) 448 if (sk->sk_family == AF_INET6) 449 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 450 #endif 451 452 sk_dst_reset(sk); 453 out: 454 release_sock(sk); 455 pr_debug("ping_v4_bind -> %d\n", err); 456 return err; 457 } 458 EXPORT_SYMBOL_GPL(ping_bind); 459 460 /* 461 * Is this a supported type of ICMP message? 462 */ 463 464 static inline int ping_supported(int family, int type, int code) 465 { 466 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 467 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0); 468 } 469 470 /* 471 * This routine is called by the ICMP module when it gets some 472 * sort of error condition. 473 */ 474 475 void ping_err(struct sk_buff *skb, int offset, u32 info) 476 { 477 int family; 478 struct icmphdr *icmph; 479 struct inet_sock *inet_sock; 480 int type; 481 int code; 482 struct net *net = dev_net(skb->dev); 483 struct sock *sk; 484 int harderr; 485 int err; 486 487 if (skb->protocol == htons(ETH_P_IP)) { 488 family = AF_INET; 489 type = icmp_hdr(skb)->type; 490 code = icmp_hdr(skb)->code; 491 icmph = (struct icmphdr *)(skb->data + offset); 492 } else if (skb->protocol == htons(ETH_P_IPV6)) { 493 family = AF_INET6; 494 type = icmp6_hdr(skb)->icmp6_type; 495 code = icmp6_hdr(skb)->icmp6_code; 496 icmph = (struct icmphdr *) (skb->data + offset); 497 } else { 498 BUG(); 499 } 500 501 /* We assume the packet has already been checked by icmp_unreach */ 502 503 if (!ping_supported(family, icmph->type, icmph->code)) 504 return; 505 506 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 507 skb->protocol, type, code, ntohs(icmph->un.echo.id), 508 ntohs(icmph->un.echo.sequence)); 509 510 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 511 if (sk == NULL) { 512 pr_debug("no socket, dropping\n"); 513 return; /* No socket for error */ 514 } 515 pr_debug("err on socket %p\n", sk); 516 517 err = 0; 518 harderr = 0; 519 inet_sock = inet_sk(sk); 520 521 if (skb->protocol == htons(ETH_P_IP)) { 522 switch (type) { 523 default: 524 case ICMP_TIME_EXCEEDED: 525 err = EHOSTUNREACH; 526 break; 527 case ICMP_SOURCE_QUENCH: 528 /* This is not a real error but ping wants to see it. 529 * Report it with some fake errno. 530 */ 531 err = EREMOTEIO; 532 break; 533 case ICMP_PARAMETERPROB: 534 err = EPROTO; 535 harderr = 1; 536 break; 537 case ICMP_DEST_UNREACH: 538 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 539 ipv4_sk_update_pmtu(skb, sk, info); 540 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 541 err = EMSGSIZE; 542 harderr = 1; 543 break; 544 } 545 goto out; 546 } 547 err = EHOSTUNREACH; 548 if (code <= NR_ICMP_UNREACH) { 549 harderr = icmp_err_convert[code].fatal; 550 err = icmp_err_convert[code].errno; 551 } 552 break; 553 case ICMP_REDIRECT: 554 /* See ICMP_SOURCE_QUENCH */ 555 ipv4_sk_redirect(skb, sk); 556 err = EREMOTEIO; 557 break; 558 } 559 #if IS_ENABLED(CONFIG_IPV6) 560 } else if (skb->protocol == htons(ETH_P_IPV6)) { 561 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 562 #endif 563 } 564 565 /* 566 * RFC1122: OK. Passes ICMP errors back to application, as per 567 * 4.1.3.3. 568 */ 569 if ((family == AF_INET && !inet_sock->recverr) || 570 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 571 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 572 goto out; 573 } else { 574 if (family == AF_INET) { 575 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 576 info, (u8 *)icmph); 577 #if IS_ENABLED(CONFIG_IPV6) 578 } else if (family == AF_INET6) { 579 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 580 info, (u8 *)icmph); 581 #endif 582 } 583 } 584 sk->sk_err = err; 585 sk->sk_error_report(sk); 586 out: 587 sock_put(sk); 588 } 589 EXPORT_SYMBOL_GPL(ping_err); 590 591 /* 592 * Copy and checksum an ICMP Echo packet from user space into a buffer 593 * starting from the payload. 594 */ 595 596 int ping_getfrag(void *from, char *to, 597 int offset, int fraglen, int odd, struct sk_buff *skb) 598 { 599 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 600 601 if (offset == 0) { 602 if (fraglen < sizeof(struct icmphdr)) 603 BUG(); 604 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr), 605 pfh->iov, 0, fraglen - sizeof(struct icmphdr), 606 &pfh->wcheck)) 607 return -EFAULT; 608 } else if (offset < sizeof(struct icmphdr)) { 609 BUG(); 610 } else { 611 if (csum_partial_copy_fromiovecend 612 (to, pfh->iov, offset - sizeof(struct icmphdr), 613 fraglen, &pfh->wcheck)) 614 return -EFAULT; 615 } 616 617 #if IS_ENABLED(CONFIG_IPV6) 618 /* For IPv6, checksum each skb as we go along, as expected by 619 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 620 * wcheck, it will be finalized in ping_v4_push_pending_frames. 621 */ 622 if (pfh->family == AF_INET6) { 623 skb->csum = pfh->wcheck; 624 skb->ip_summed = CHECKSUM_NONE; 625 pfh->wcheck = 0; 626 } 627 #endif 628 629 return 0; 630 } 631 EXPORT_SYMBOL_GPL(ping_getfrag); 632 633 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 634 struct flowi4 *fl4) 635 { 636 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 637 638 pfh->wcheck = csum_partial((char *)&pfh->icmph, 639 sizeof(struct icmphdr), pfh->wcheck); 640 pfh->icmph.checksum = csum_fold(pfh->wcheck); 641 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 642 skb->ip_summed = CHECKSUM_NONE; 643 return ip_push_pending_frames(sk, fl4); 644 } 645 646 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 647 void *user_icmph, size_t icmph_len) { 648 u8 type, code; 649 650 if (len > 0xFFFF) 651 return -EMSGSIZE; 652 653 /* 654 * Check the flags. 655 */ 656 657 /* Mirror BSD error message compatibility */ 658 if (msg->msg_flags & MSG_OOB) 659 return -EOPNOTSUPP; 660 661 /* 662 * Fetch the ICMP header provided by the userland. 663 * iovec is modified! The ICMP header is consumed. 664 */ 665 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 666 return -EFAULT; 667 668 if (family == AF_INET) { 669 type = ((struct icmphdr *) user_icmph)->type; 670 code = ((struct icmphdr *) user_icmph)->code; 671 #if IS_ENABLED(CONFIG_IPV6) 672 } else if (family == AF_INET6) { 673 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 674 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 675 #endif 676 } else { 677 BUG(); 678 } 679 680 if (!ping_supported(family, type, code)) 681 return -EINVAL; 682 683 return 0; 684 } 685 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 686 687 static int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 688 size_t len) 689 { 690 struct net *net = sock_net(sk); 691 struct flowi4 fl4; 692 struct inet_sock *inet = inet_sk(sk); 693 struct ipcm_cookie ipc; 694 struct icmphdr user_icmph; 695 struct pingfakehdr pfh; 696 struct rtable *rt = NULL; 697 struct ip_options_data opt_copy; 698 int free = 0; 699 __be32 saddr, daddr, faddr; 700 u8 tos; 701 int err; 702 703 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 704 705 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 706 sizeof(user_icmph)); 707 if (err) 708 return err; 709 710 /* 711 * Get and verify the address. 712 */ 713 714 if (msg->msg_name) { 715 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 716 if (msg->msg_namelen < sizeof(*usin)) 717 return -EINVAL; 718 if (usin->sin_family != AF_INET) 719 return -EINVAL; 720 daddr = usin->sin_addr.s_addr; 721 /* no remote port */ 722 } else { 723 if (sk->sk_state != TCP_ESTABLISHED) 724 return -EDESTADDRREQ; 725 daddr = inet->inet_daddr; 726 /* no remote port */ 727 } 728 729 ipc.addr = inet->inet_saddr; 730 ipc.opt = NULL; 731 ipc.oif = sk->sk_bound_dev_if; 732 ipc.tx_flags = 0; 733 ipc.ttl = 0; 734 ipc.tos = -1; 735 736 sock_tx_timestamp(sk, &ipc.tx_flags); 737 738 if (msg->msg_controllen) { 739 err = ip_cmsg_send(sock_net(sk), msg, &ipc, false); 740 if (err) 741 return err; 742 if (ipc.opt) 743 free = 1; 744 } 745 if (!ipc.opt) { 746 struct ip_options_rcu *inet_opt; 747 748 rcu_read_lock(); 749 inet_opt = rcu_dereference(inet->inet_opt); 750 if (inet_opt) { 751 memcpy(&opt_copy, inet_opt, 752 sizeof(*inet_opt) + inet_opt->opt.optlen); 753 ipc.opt = &opt_copy.opt; 754 } 755 rcu_read_unlock(); 756 } 757 758 saddr = ipc.addr; 759 ipc.addr = faddr = daddr; 760 761 if (ipc.opt && ipc.opt->opt.srr) { 762 if (!daddr) 763 return -EINVAL; 764 faddr = ipc.opt->opt.faddr; 765 } 766 tos = get_rttos(&ipc, inet); 767 if (sock_flag(sk, SOCK_LOCALROUTE) || 768 (msg->msg_flags & MSG_DONTROUTE) || 769 (ipc.opt && ipc.opt->opt.is_strictroute)) { 770 tos |= RTO_ONLINK; 771 } 772 773 if (ipv4_is_multicast(daddr)) { 774 if (!ipc.oif) 775 ipc.oif = inet->mc_index; 776 if (!saddr) 777 saddr = inet->mc_addr; 778 } else if (!ipc.oif) 779 ipc.oif = inet->uc_index; 780 781 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos, 782 RT_SCOPE_UNIVERSE, sk->sk_protocol, 783 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0); 784 785 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 786 rt = ip_route_output_flow(net, &fl4, sk); 787 if (IS_ERR(rt)) { 788 err = PTR_ERR(rt); 789 rt = NULL; 790 if (err == -ENETUNREACH) 791 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 792 goto out; 793 } 794 795 err = -EACCES; 796 if ((rt->rt_flags & RTCF_BROADCAST) && 797 !sock_flag(sk, SOCK_BROADCAST)) 798 goto out; 799 800 if (msg->msg_flags & MSG_CONFIRM) 801 goto do_confirm; 802 back_from_confirm: 803 804 if (!ipc.addr) 805 ipc.addr = fl4.daddr; 806 807 lock_sock(sk); 808 809 pfh.icmph.type = user_icmph.type; /* already checked */ 810 pfh.icmph.code = user_icmph.code; /* ditto */ 811 pfh.icmph.checksum = 0; 812 pfh.icmph.un.echo.id = inet->inet_sport; 813 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 814 /* XXX: stripping const */ 815 pfh.iov = (struct iovec *)msg->msg_iter.iov; 816 pfh.wcheck = 0; 817 pfh.family = AF_INET; 818 819 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 820 0, &ipc, &rt, msg->msg_flags); 821 if (err) 822 ip_flush_pending_frames(sk); 823 else 824 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 825 release_sock(sk); 826 827 out: 828 ip_rt_put(rt); 829 if (free) 830 kfree(ipc.opt); 831 if (!err) { 832 icmp_out_count(sock_net(sk), user_icmph.type); 833 return len; 834 } 835 return err; 836 837 do_confirm: 838 dst_confirm(&rt->dst); 839 if (!(msg->msg_flags & MSG_PROBE) || len) 840 goto back_from_confirm; 841 err = 0; 842 goto out; 843 } 844 845 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 846 size_t len, int noblock, int flags, int *addr_len) 847 { 848 struct inet_sock *isk = inet_sk(sk); 849 int family = sk->sk_family; 850 struct sk_buff *skb; 851 int copied, err; 852 853 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 854 855 err = -EOPNOTSUPP; 856 if (flags & MSG_OOB) 857 goto out; 858 859 if (flags & MSG_ERRQUEUE) 860 return inet_recv_error(sk, msg, len, addr_len); 861 862 skb = skb_recv_datagram(sk, flags, noblock, &err); 863 if (!skb) 864 goto out; 865 866 copied = skb->len; 867 if (copied > len) { 868 msg->msg_flags |= MSG_TRUNC; 869 copied = len; 870 } 871 872 /* Don't bother checking the checksum */ 873 err = skb_copy_datagram_msg(skb, 0, msg, copied); 874 if (err) 875 goto done; 876 877 sock_recv_timestamp(msg, sk, skb); 878 879 /* Copy the address and add cmsg data. */ 880 if (family == AF_INET) { 881 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 882 883 if (sin) { 884 sin->sin_family = AF_INET; 885 sin->sin_port = 0 /* skb->h.uh->source */; 886 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 887 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 888 *addr_len = sizeof(*sin); 889 } 890 891 if (isk->cmsg_flags) 892 ip_cmsg_recv(msg, skb); 893 894 #if IS_ENABLED(CONFIG_IPV6) 895 } else if (family == AF_INET6) { 896 struct ipv6_pinfo *np = inet6_sk(sk); 897 struct ipv6hdr *ip6 = ipv6_hdr(skb); 898 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 899 900 if (sin6) { 901 sin6->sin6_family = AF_INET6; 902 sin6->sin6_port = 0; 903 sin6->sin6_addr = ip6->saddr; 904 sin6->sin6_flowinfo = 0; 905 if (np->sndflow) 906 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 907 sin6->sin6_scope_id = 908 ipv6_iface_scope_id(&sin6->sin6_addr, 909 inet6_iif(skb)); 910 *addr_len = sizeof(*sin6); 911 } 912 913 if (inet6_sk(sk)->rxopt.all) 914 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 915 if (skb->protocol == htons(ETH_P_IPV6) && 916 inet6_sk(sk)->rxopt.all) 917 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 918 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 919 ip_cmsg_recv(msg, skb); 920 #endif 921 } else { 922 BUG(); 923 } 924 925 err = copied; 926 927 done: 928 skb_free_datagram(sk, skb); 929 out: 930 pr_debug("ping_recvmsg -> %d\n", err); 931 return err; 932 } 933 EXPORT_SYMBOL_GPL(ping_recvmsg); 934 935 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 936 { 937 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 938 inet_sk(sk), inet_sk(sk)->inet_num, skb); 939 if (sock_queue_rcv_skb(sk, skb) < 0) { 940 kfree_skb(skb); 941 pr_debug("ping_queue_rcv_skb -> failed\n"); 942 return -1; 943 } 944 return 0; 945 } 946 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 947 948 949 /* 950 * All we need to do is get the socket. 951 */ 952 953 bool ping_rcv(struct sk_buff *skb) 954 { 955 struct sock *sk; 956 struct net *net = dev_net(skb->dev); 957 struct icmphdr *icmph = icmp_hdr(skb); 958 959 /* We assume the packet has already been checked by icmp_rcv */ 960 961 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 962 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 963 964 /* Push ICMP header back */ 965 skb_push(skb, skb->data - (u8 *)icmph); 966 967 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 968 if (sk != NULL) { 969 pr_debug("rcv on socket %p\n", sk); 970 ping_queue_rcv_skb(sk, skb_get(skb)); 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 { 1056 struct ping_iter_state *state = seq->private; 1057 state->bucket = 0; 1058 state->family = family; 1059 1060 read_lock_bh(&ping_table.lock); 1061 1062 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1063 } 1064 EXPORT_SYMBOL_GPL(ping_seq_start); 1065 1066 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1067 { 1068 return ping_seq_start(seq, pos, AF_INET); 1069 } 1070 1071 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1072 { 1073 struct sock *sk; 1074 1075 if (v == SEQ_START_TOKEN) 1076 sk = ping_get_idx(seq, 0); 1077 else 1078 sk = ping_get_next(seq, v); 1079 1080 ++*pos; 1081 return sk; 1082 } 1083 EXPORT_SYMBOL_GPL(ping_seq_next); 1084 1085 void ping_seq_stop(struct seq_file *seq, void *v) 1086 { 1087 read_unlock_bh(&ping_table.lock); 1088 } 1089 EXPORT_SYMBOL_GPL(ping_seq_stop); 1090 1091 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1092 int bucket) 1093 { 1094 struct inet_sock *inet = inet_sk(sp); 1095 __be32 dest = inet->inet_daddr; 1096 __be32 src = inet->inet_rcv_saddr; 1097 __u16 destp = ntohs(inet->inet_dport); 1098 __u16 srcp = ntohs(inet->inet_sport); 1099 1100 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1101 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 1102 bucket, src, srcp, dest, destp, sp->sk_state, 1103 sk_wmem_alloc_get(sp), 1104 sk_rmem_alloc_get(sp), 1105 0, 0L, 0, 1106 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1107 0, sock_i_ino(sp), 1108 atomic_read(&sp->sk_refcnt), sp, 1109 atomic_read(&sp->sk_drops)); 1110 } 1111 1112 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1113 { 1114 seq_setwidth(seq, 127); 1115 if (v == SEQ_START_TOKEN) 1116 seq_puts(seq, " sl local_address rem_address st tx_queue " 1117 "rx_queue tr tm->when retrnsmt uid timeout " 1118 "inode ref pointer drops"); 1119 else { 1120 struct ping_iter_state *state = seq->private; 1121 1122 ping_v4_format_sock(v, seq, state->bucket); 1123 } 1124 seq_pad(seq, '\n'); 1125 return 0; 1126 } 1127 1128 static const struct seq_operations ping_v4_seq_ops = { 1129 .show = ping_v4_seq_show, 1130 .start = ping_v4_seq_start, 1131 .next = ping_seq_next, 1132 .stop = ping_seq_stop, 1133 }; 1134 1135 static int ping_seq_open(struct inode *inode, struct file *file) 1136 { 1137 struct ping_seq_afinfo *afinfo = PDE_DATA(inode); 1138 return seq_open_net(inode, file, &afinfo->seq_ops, 1139 sizeof(struct ping_iter_state)); 1140 } 1141 1142 const struct file_operations ping_seq_fops = { 1143 .open = ping_seq_open, 1144 .read = seq_read, 1145 .llseek = seq_lseek, 1146 .release = seq_release_net, 1147 }; 1148 EXPORT_SYMBOL_GPL(ping_seq_fops); 1149 1150 static struct ping_seq_afinfo ping_v4_seq_afinfo = { 1151 .name = "icmp", 1152 .family = AF_INET, 1153 .seq_fops = &ping_seq_fops, 1154 .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 1162 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo) 1163 { 1164 struct proc_dir_entry *p; 1165 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 1166 afinfo->seq_fops, afinfo); 1167 if (!p) 1168 return -ENOMEM; 1169 return 0; 1170 } 1171 EXPORT_SYMBOL_GPL(ping_proc_register); 1172 1173 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo) 1174 { 1175 remove_proc_entry(afinfo->name, net->proc_net); 1176 } 1177 EXPORT_SYMBOL_GPL(ping_proc_unregister); 1178 1179 static int __net_init ping_v4_proc_init_net(struct net *net) 1180 { 1181 return ping_proc_register(net, &ping_v4_seq_afinfo); 1182 } 1183 1184 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1185 { 1186 ping_proc_unregister(net, &ping_v4_seq_afinfo); 1187 } 1188 1189 static struct pernet_operations ping_v4_net_ops = { 1190 .init = ping_v4_proc_init_net, 1191 .exit = ping_v4_proc_exit_net, 1192 }; 1193 1194 int __init ping_proc_init(void) 1195 { 1196 return register_pernet_subsys(&ping_v4_net_ops); 1197 } 1198 1199 void ping_proc_exit(void) 1200 { 1201 unregister_pernet_subsys(&ping_v4_net_ops); 1202 } 1203 1204 #endif 1205 1206 void __init ping_init(void) 1207 { 1208 int i; 1209 1210 for (i = 0; i < PING_HTABLE_SIZE; i++) 1211 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1212 rwlock_init(&ping_table.lock); 1213 } 1214