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 } 221 222 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) 223 continue; 224 225 sock_hold(sk); 226 goto exit; 227 } 228 229 sk = NULL; 230 exit: 231 read_unlock_bh(&ping_table.lock); 232 233 return sk; 234 } 235 236 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 237 kgid_t *high) 238 { 239 kgid_t *data = net->ipv4.sysctl_ping_group_range; 240 unsigned int seq; 241 242 do { 243 seq = read_seqbegin(&net->ipv4.sysctl_local_ports.lock); 244 245 *low = data[0]; 246 *high = data[1]; 247 } while (read_seqretry(&net->ipv4.sysctl_local_ports.lock, seq)); 248 } 249 250 251 int ping_init_sock(struct sock *sk) 252 { 253 struct net *net = sock_net(sk); 254 kgid_t group = current_egid(); 255 struct group_info *group_info = get_current_groups(); 256 int i, j, count = group_info->ngroups; 257 kgid_t low, high; 258 259 inet_get_ping_group_range_net(net, &low, &high); 260 if (gid_lte(low, group) && gid_lte(group, high)) 261 return 0; 262 263 for (i = 0; i < group_info->nblocks; i++) { 264 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count); 265 for (j = 0; j < cp_count; j++) { 266 kgid_t gid = group_info->blocks[i][j]; 267 if (gid_lte(low, gid) && gid_lte(gid, high)) 268 return 0; 269 } 270 271 count -= cp_count; 272 } 273 274 return -EACCES; 275 } 276 EXPORT_SYMBOL_GPL(ping_init_sock); 277 278 void ping_close(struct sock *sk, long timeout) 279 { 280 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 281 inet_sk(sk), inet_sk(sk)->inet_num); 282 pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter); 283 284 sk_common_release(sk); 285 } 286 EXPORT_SYMBOL_GPL(ping_close); 287 288 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 289 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 290 struct sockaddr *uaddr, int addr_len) { 291 struct net *net = sock_net(sk); 292 if (sk->sk_family == AF_INET) { 293 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 294 int chk_addr_ret; 295 296 if (addr_len < sizeof(*addr)) 297 return -EINVAL; 298 299 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 300 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 301 302 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); 303 304 if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) 305 chk_addr_ret = RTN_LOCAL; 306 307 if ((sysctl_ip_nonlocal_bind == 0 && 308 isk->freebind == 0 && isk->transparent == 0 && 309 chk_addr_ret != RTN_LOCAL) || 310 chk_addr_ret == RTN_MULTICAST || 311 chk_addr_ret == RTN_BROADCAST) 312 return -EADDRNOTAVAIL; 313 314 #if IS_ENABLED(CONFIG_IPV6) 315 } else if (sk->sk_family == AF_INET6) { 316 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 317 int addr_type, scoped, has_addr; 318 struct net_device *dev = NULL; 319 320 if (addr_len < sizeof(*addr)) 321 return -EINVAL; 322 323 if (addr->sin6_family != AF_INET6) 324 return -EINVAL; 325 326 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 327 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 328 329 addr_type = ipv6_addr_type(&addr->sin6_addr); 330 scoped = __ipv6_addr_needs_scope_id(addr_type); 331 if ((addr_type != IPV6_ADDR_ANY && 332 !(addr_type & IPV6_ADDR_UNICAST)) || 333 (scoped && !addr->sin6_scope_id)) 334 return -EINVAL; 335 336 rcu_read_lock(); 337 if (addr->sin6_scope_id) { 338 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 339 if (!dev) { 340 rcu_read_unlock(); 341 return -ENODEV; 342 } 343 } 344 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 345 scoped); 346 rcu_read_unlock(); 347 348 if (!(isk->freebind || isk->transparent || has_addr || 349 addr_type == IPV6_ADDR_ANY)) 350 return -EADDRNOTAVAIL; 351 352 if (scoped) 353 sk->sk_bound_dev_if = addr->sin6_scope_id; 354 #endif 355 } else { 356 return -EAFNOSUPPORT; 357 } 358 return 0; 359 } 360 361 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 362 { 363 if (saddr->sa_family == AF_INET) { 364 struct inet_sock *isk = inet_sk(sk); 365 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 366 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 367 #if IS_ENABLED(CONFIG_IPV6) 368 } else if (saddr->sa_family == AF_INET6) { 369 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 370 struct ipv6_pinfo *np = inet6_sk(sk); 371 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 372 #endif 373 } 374 } 375 376 static void ping_clear_saddr(struct sock *sk, int dif) 377 { 378 sk->sk_bound_dev_if = dif; 379 if (sk->sk_family == AF_INET) { 380 struct inet_sock *isk = inet_sk(sk); 381 isk->inet_rcv_saddr = isk->inet_saddr = 0; 382 #if IS_ENABLED(CONFIG_IPV6) 383 } else if (sk->sk_family == AF_INET6) { 384 struct ipv6_pinfo *np = inet6_sk(sk); 385 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 386 memset(&np->saddr, 0, sizeof(np->saddr)); 387 #endif 388 } 389 } 390 /* 391 * We need our own bind because there are no privileged id's == local ports. 392 * Moreover, we don't allow binding to multi- and broadcast addresses. 393 */ 394 395 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 396 { 397 struct inet_sock *isk = inet_sk(sk); 398 unsigned short snum; 399 int err; 400 int dif = sk->sk_bound_dev_if; 401 402 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 403 if (err) 404 return err; 405 406 lock_sock(sk); 407 408 err = -EINVAL; 409 if (isk->inet_num != 0) 410 goto out; 411 412 err = -EADDRINUSE; 413 ping_set_saddr(sk, uaddr); 414 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 415 if (ping_get_port(sk, snum) != 0) { 416 ping_clear_saddr(sk, dif); 417 goto out; 418 } 419 420 pr_debug("after bind(): num = %d, dif = %d\n", 421 (int)isk->inet_num, 422 (int)sk->sk_bound_dev_if); 423 424 err = 0; 425 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 426 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 427 #if IS_ENABLED(CONFIG_IPV6) 428 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 429 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 430 #endif 431 432 if (snum) 433 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 434 isk->inet_sport = htons(isk->inet_num); 435 isk->inet_daddr = 0; 436 isk->inet_dport = 0; 437 438 #if IS_ENABLED(CONFIG_IPV6) 439 if (sk->sk_family == AF_INET6) 440 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 441 #endif 442 443 sk_dst_reset(sk); 444 out: 445 release_sock(sk); 446 pr_debug("ping_v4_bind -> %d\n", err); 447 return err; 448 } 449 EXPORT_SYMBOL_GPL(ping_bind); 450 451 /* 452 * Is this a supported type of ICMP message? 453 */ 454 455 static inline int ping_supported(int family, int type, int code) 456 { 457 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 458 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0); 459 } 460 461 /* 462 * This routine is called by the ICMP module when it gets some 463 * sort of error condition. 464 */ 465 466 void ping_err(struct sk_buff *skb, int offset, u32 info) 467 { 468 int family; 469 struct icmphdr *icmph; 470 struct inet_sock *inet_sock; 471 int type; 472 int code; 473 struct net *net = dev_net(skb->dev); 474 struct sock *sk; 475 int harderr; 476 int err; 477 478 if (skb->protocol == htons(ETH_P_IP)) { 479 family = AF_INET; 480 type = icmp_hdr(skb)->type; 481 code = icmp_hdr(skb)->code; 482 icmph = (struct icmphdr *)(skb->data + offset); 483 } else if (skb->protocol == htons(ETH_P_IPV6)) { 484 family = AF_INET6; 485 type = icmp6_hdr(skb)->icmp6_type; 486 code = icmp6_hdr(skb)->icmp6_code; 487 icmph = (struct icmphdr *) (skb->data + offset); 488 } else { 489 BUG(); 490 } 491 492 /* We assume the packet has already been checked by icmp_unreach */ 493 494 if (!ping_supported(family, icmph->type, icmph->code)) 495 return; 496 497 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 498 skb->protocol, type, code, ntohs(icmph->un.echo.id), 499 ntohs(icmph->un.echo.sequence)); 500 501 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 502 if (sk == NULL) { 503 pr_debug("no socket, dropping\n"); 504 return; /* No socket for error */ 505 } 506 pr_debug("err on socket %p\n", sk); 507 508 err = 0; 509 harderr = 0; 510 inet_sock = inet_sk(sk); 511 512 if (skb->protocol == htons(ETH_P_IP)) { 513 switch (type) { 514 default: 515 case ICMP_TIME_EXCEEDED: 516 err = EHOSTUNREACH; 517 break; 518 case ICMP_SOURCE_QUENCH: 519 /* This is not a real error but ping wants to see it. 520 * Report it with some fake errno. 521 */ 522 err = EREMOTEIO; 523 break; 524 case ICMP_PARAMETERPROB: 525 err = EPROTO; 526 harderr = 1; 527 break; 528 case ICMP_DEST_UNREACH: 529 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 530 ipv4_sk_update_pmtu(skb, sk, info); 531 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 532 err = EMSGSIZE; 533 harderr = 1; 534 break; 535 } 536 goto out; 537 } 538 err = EHOSTUNREACH; 539 if (code <= NR_ICMP_UNREACH) { 540 harderr = icmp_err_convert[code].fatal; 541 err = icmp_err_convert[code].errno; 542 } 543 break; 544 case ICMP_REDIRECT: 545 /* See ICMP_SOURCE_QUENCH */ 546 ipv4_sk_redirect(skb, sk); 547 err = EREMOTEIO; 548 break; 549 } 550 #if IS_ENABLED(CONFIG_IPV6) 551 } else if (skb->protocol == htons(ETH_P_IPV6)) { 552 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 553 #endif 554 } 555 556 /* 557 * RFC1122: OK. Passes ICMP errors back to application, as per 558 * 4.1.3.3. 559 */ 560 if ((family == AF_INET && !inet_sock->recverr) || 561 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 562 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 563 goto out; 564 } else { 565 if (family == AF_INET) { 566 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 567 info, (u8 *)icmph); 568 #if IS_ENABLED(CONFIG_IPV6) 569 } else if (family == AF_INET6) { 570 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 571 info, (u8 *)icmph); 572 #endif 573 } 574 } 575 sk->sk_err = err; 576 sk->sk_error_report(sk); 577 out: 578 sock_put(sk); 579 } 580 EXPORT_SYMBOL_GPL(ping_err); 581 582 /* 583 * Copy and checksum an ICMP Echo packet from user space into a buffer 584 * starting from the payload. 585 */ 586 587 int ping_getfrag(void *from, char *to, 588 int offset, int fraglen, int odd, struct sk_buff *skb) 589 { 590 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 591 592 if (offset == 0) { 593 if (fraglen < sizeof(struct icmphdr)) 594 BUG(); 595 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr), 596 pfh->iov, 0, fraglen - sizeof(struct icmphdr), 597 &pfh->wcheck)) 598 return -EFAULT; 599 } else if (offset < sizeof(struct icmphdr)) { 600 BUG(); 601 } else { 602 if (csum_partial_copy_fromiovecend 603 (to, pfh->iov, offset - sizeof(struct icmphdr), 604 fraglen, &pfh->wcheck)) 605 return -EFAULT; 606 } 607 608 #if IS_ENABLED(CONFIG_IPV6) 609 /* For IPv6, checksum each skb as we go along, as expected by 610 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 611 * wcheck, it will be finalized in ping_v4_push_pending_frames. 612 */ 613 if (pfh->family == AF_INET6) { 614 skb->csum = pfh->wcheck; 615 skb->ip_summed = CHECKSUM_NONE; 616 pfh->wcheck = 0; 617 } 618 #endif 619 620 return 0; 621 } 622 EXPORT_SYMBOL_GPL(ping_getfrag); 623 624 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 625 struct flowi4 *fl4) 626 { 627 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 628 629 pfh->wcheck = csum_partial((char *)&pfh->icmph, 630 sizeof(struct icmphdr), pfh->wcheck); 631 pfh->icmph.checksum = csum_fold(pfh->wcheck); 632 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 633 skb->ip_summed = CHECKSUM_NONE; 634 return ip_push_pending_frames(sk, fl4); 635 } 636 637 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 638 void *user_icmph, size_t icmph_len) { 639 u8 type, code; 640 641 if (len > 0xFFFF) 642 return -EMSGSIZE; 643 644 /* 645 * Check the flags. 646 */ 647 648 /* Mirror BSD error message compatibility */ 649 if (msg->msg_flags & MSG_OOB) 650 return -EOPNOTSUPP; 651 652 /* 653 * Fetch the ICMP header provided by the userland. 654 * iovec is modified! The ICMP header is consumed. 655 */ 656 if (memcpy_fromiovec(user_icmph, msg->msg_iov, icmph_len)) 657 return -EFAULT; 658 659 if (family == AF_INET) { 660 type = ((struct icmphdr *) user_icmph)->type; 661 code = ((struct icmphdr *) user_icmph)->code; 662 #if IS_ENABLED(CONFIG_IPV6) 663 } else if (family == AF_INET6) { 664 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 665 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 666 #endif 667 } else { 668 BUG(); 669 } 670 671 if (!ping_supported(family, type, code)) 672 return -EINVAL; 673 674 return 0; 675 } 676 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 677 678 static int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 679 size_t len) 680 { 681 struct net *net = sock_net(sk); 682 struct flowi4 fl4; 683 struct inet_sock *inet = inet_sk(sk); 684 struct ipcm_cookie ipc; 685 struct icmphdr user_icmph; 686 struct pingfakehdr pfh; 687 struct rtable *rt = NULL; 688 struct ip_options_data opt_copy; 689 int free = 0; 690 __be32 saddr, daddr, faddr; 691 u8 tos; 692 int err; 693 694 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 695 696 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 697 sizeof(user_icmph)); 698 if (err) 699 return err; 700 701 /* 702 * Get and verify the address. 703 */ 704 705 if (msg->msg_name) { 706 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 707 if (msg->msg_namelen < sizeof(*usin)) 708 return -EINVAL; 709 if (usin->sin_family != AF_INET) 710 return -EINVAL; 711 daddr = usin->sin_addr.s_addr; 712 /* no remote port */ 713 } else { 714 if (sk->sk_state != TCP_ESTABLISHED) 715 return -EDESTADDRREQ; 716 daddr = inet->inet_daddr; 717 /* no remote port */ 718 } 719 720 ipc.addr = inet->inet_saddr; 721 ipc.opt = NULL; 722 ipc.oif = sk->sk_bound_dev_if; 723 ipc.tx_flags = 0; 724 ipc.ttl = 0; 725 ipc.tos = -1; 726 727 sock_tx_timestamp(sk, &ipc.tx_flags); 728 729 if (msg->msg_controllen) { 730 err = ip_cmsg_send(sock_net(sk), msg, &ipc); 731 if (err) 732 return err; 733 if (ipc.opt) 734 free = 1; 735 } 736 if (!ipc.opt) { 737 struct ip_options_rcu *inet_opt; 738 739 rcu_read_lock(); 740 inet_opt = rcu_dereference(inet->inet_opt); 741 if (inet_opt) { 742 memcpy(&opt_copy, inet_opt, 743 sizeof(*inet_opt) + inet_opt->opt.optlen); 744 ipc.opt = &opt_copy.opt; 745 } 746 rcu_read_unlock(); 747 } 748 749 saddr = ipc.addr; 750 ipc.addr = faddr = daddr; 751 752 if (ipc.opt && ipc.opt->opt.srr) { 753 if (!daddr) 754 return -EINVAL; 755 faddr = ipc.opt->opt.faddr; 756 } 757 tos = get_rttos(&ipc, inet); 758 if (sock_flag(sk, SOCK_LOCALROUTE) || 759 (msg->msg_flags & MSG_DONTROUTE) || 760 (ipc.opt && ipc.opt->opt.is_strictroute)) { 761 tos |= RTO_ONLINK; 762 } 763 764 if (ipv4_is_multicast(daddr)) { 765 if (!ipc.oif) 766 ipc.oif = inet->mc_index; 767 if (!saddr) 768 saddr = inet->mc_addr; 769 } else if (!ipc.oif) 770 ipc.oif = inet->uc_index; 771 772 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos, 773 RT_SCOPE_UNIVERSE, sk->sk_protocol, 774 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0); 775 776 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 777 rt = ip_route_output_flow(net, &fl4, sk); 778 if (IS_ERR(rt)) { 779 err = PTR_ERR(rt); 780 rt = NULL; 781 if (err == -ENETUNREACH) 782 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 783 goto out; 784 } 785 786 err = -EACCES; 787 if ((rt->rt_flags & RTCF_BROADCAST) && 788 !sock_flag(sk, SOCK_BROADCAST)) 789 goto out; 790 791 if (msg->msg_flags & MSG_CONFIRM) 792 goto do_confirm; 793 back_from_confirm: 794 795 if (!ipc.addr) 796 ipc.addr = fl4.daddr; 797 798 lock_sock(sk); 799 800 pfh.icmph.type = user_icmph.type; /* already checked */ 801 pfh.icmph.code = user_icmph.code; /* ditto */ 802 pfh.icmph.checksum = 0; 803 pfh.icmph.un.echo.id = inet->inet_sport; 804 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 805 pfh.iov = msg->msg_iov; 806 pfh.wcheck = 0; 807 pfh.family = AF_INET; 808 809 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 810 0, &ipc, &rt, msg->msg_flags); 811 if (err) 812 ip_flush_pending_frames(sk); 813 else 814 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 815 release_sock(sk); 816 817 out: 818 ip_rt_put(rt); 819 if (free) 820 kfree(ipc.opt); 821 if (!err) { 822 icmp_out_count(sock_net(sk), user_icmph.type); 823 return len; 824 } 825 return err; 826 827 do_confirm: 828 dst_confirm(&rt->dst); 829 if (!(msg->msg_flags & MSG_PROBE) || len) 830 goto back_from_confirm; 831 err = 0; 832 goto out; 833 } 834 835 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 836 size_t len, int noblock, int flags, int *addr_len) 837 { 838 struct inet_sock *isk = inet_sk(sk); 839 int family = sk->sk_family; 840 struct sk_buff *skb; 841 int copied, err; 842 843 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 844 845 err = -EOPNOTSUPP; 846 if (flags & MSG_OOB) 847 goto out; 848 849 if (flags & MSG_ERRQUEUE) { 850 if (family == AF_INET) { 851 return ip_recv_error(sk, msg, len, addr_len); 852 #if IS_ENABLED(CONFIG_IPV6) 853 } else if (family == AF_INET6) { 854 return pingv6_ops.ipv6_recv_error(sk, msg, len, 855 addr_len); 856 #endif 857 } 858 } 859 860 skb = skb_recv_datagram(sk, flags, noblock, &err); 861 if (!skb) 862 goto out; 863 864 copied = skb->len; 865 if (copied > len) { 866 msg->msg_flags |= MSG_TRUNC; 867 copied = len; 868 } 869 870 /* Don't bother checking the checksum */ 871 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 872 if (err) 873 goto done; 874 875 sock_recv_timestamp(msg, sk, skb); 876 877 /* Copy the address and add cmsg data. */ 878 if (family == AF_INET) { 879 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 880 881 if (sin) { 882 sin->sin_family = AF_INET; 883 sin->sin_port = 0 /* skb->h.uh->source */; 884 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 885 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 886 *addr_len = sizeof(*sin); 887 } 888 889 if (isk->cmsg_flags) 890 ip_cmsg_recv(msg, skb); 891 892 #if IS_ENABLED(CONFIG_IPV6) 893 } else if (family == AF_INET6) { 894 struct ipv6_pinfo *np = inet6_sk(sk); 895 struct ipv6hdr *ip6 = ipv6_hdr(skb); 896 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 897 898 if (sin6) { 899 sin6->sin6_family = AF_INET6; 900 sin6->sin6_port = 0; 901 sin6->sin6_addr = ip6->saddr; 902 sin6->sin6_flowinfo = 0; 903 if (np->sndflow) 904 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 905 sin6->sin6_scope_id = 906 ipv6_iface_scope_id(&sin6->sin6_addr, 907 IP6CB(skb)->iif); 908 *addr_len = sizeof(*sin6); 909 } 910 911 if (inet6_sk(sk)->rxopt.all) 912 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 913 if (skb->protocol == htons(ETH_P_IPV6) && 914 inet6_sk(sk)->rxopt.all) 915 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 916 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 917 ip_cmsg_recv(msg, skb); 918 #endif 919 } else { 920 BUG(); 921 } 922 923 err = copied; 924 925 done: 926 skb_free_datagram(sk, skb); 927 out: 928 pr_debug("ping_recvmsg -> %d\n", err); 929 return err; 930 } 931 EXPORT_SYMBOL_GPL(ping_recvmsg); 932 933 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 934 { 935 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 936 inet_sk(sk), inet_sk(sk)->inet_num, skb); 937 if (sock_queue_rcv_skb(sk, skb) < 0) { 938 kfree_skb(skb); 939 pr_debug("ping_queue_rcv_skb -> failed\n"); 940 return -1; 941 } 942 return 0; 943 } 944 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 945 946 947 /* 948 * All we need to do is get the socket. 949 */ 950 951 void ping_rcv(struct sk_buff *skb) 952 { 953 struct sock *sk; 954 struct net *net = dev_net(skb->dev); 955 struct icmphdr *icmph = icmp_hdr(skb); 956 957 /* We assume the packet has already been checked by icmp_rcv */ 958 959 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 960 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 961 962 /* Push ICMP header back */ 963 skb_push(skb, skb->data - (u8 *)icmph); 964 965 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 966 if (sk != NULL) { 967 pr_debug("rcv on socket %p\n", sk); 968 ping_queue_rcv_skb(sk, skb_get(skb)); 969 sock_put(sk); 970 return; 971 } 972 pr_debug("no socket, dropping\n"); 973 974 /* We're called from icmp_rcv(). kfree_skb() is done there. */ 975 } 976 EXPORT_SYMBOL_GPL(ping_rcv); 977 978 struct proto ping_prot = { 979 .name = "PING", 980 .owner = THIS_MODULE, 981 .init = ping_init_sock, 982 .close = ping_close, 983 .connect = ip4_datagram_connect, 984 .disconnect = udp_disconnect, 985 .setsockopt = ip_setsockopt, 986 .getsockopt = ip_getsockopt, 987 .sendmsg = ping_v4_sendmsg, 988 .recvmsg = ping_recvmsg, 989 .bind = ping_bind, 990 .backlog_rcv = ping_queue_rcv_skb, 991 .release_cb = ip4_datagram_release_cb, 992 .hash = ping_hash, 993 .unhash = ping_unhash, 994 .get_port = ping_get_port, 995 .obj_size = sizeof(struct inet_sock), 996 }; 997 EXPORT_SYMBOL(ping_prot); 998 999 #ifdef CONFIG_PROC_FS 1000 1001 static struct sock *ping_get_first(struct seq_file *seq, int start) 1002 { 1003 struct sock *sk; 1004 struct ping_iter_state *state = seq->private; 1005 struct net *net = seq_file_net(seq); 1006 1007 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1008 ++state->bucket) { 1009 struct hlist_nulls_node *node; 1010 struct hlist_nulls_head *hslot; 1011 1012 hslot = &ping_table.hash[state->bucket]; 1013 1014 if (hlist_nulls_empty(hslot)) 1015 continue; 1016 1017 sk_nulls_for_each(sk, node, hslot) { 1018 if (net_eq(sock_net(sk), net) && 1019 sk->sk_family == state->family) 1020 goto found; 1021 } 1022 } 1023 sk = NULL; 1024 found: 1025 return sk; 1026 } 1027 1028 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1029 { 1030 struct ping_iter_state *state = seq->private; 1031 struct net *net = seq_file_net(seq); 1032 1033 do { 1034 sk = sk_nulls_next(sk); 1035 } while (sk && (!net_eq(sock_net(sk), net))); 1036 1037 if (!sk) 1038 return ping_get_first(seq, state->bucket + 1); 1039 return sk; 1040 } 1041 1042 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1043 { 1044 struct sock *sk = ping_get_first(seq, 0); 1045 1046 if (sk) 1047 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1048 --pos; 1049 return pos ? NULL : sk; 1050 } 1051 1052 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1053 { 1054 struct ping_iter_state *state = seq->private; 1055 state->bucket = 0; 1056 state->family = family; 1057 1058 read_lock_bh(&ping_table.lock); 1059 1060 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1061 } 1062 EXPORT_SYMBOL_GPL(ping_seq_start); 1063 1064 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1065 { 1066 return ping_seq_start(seq, pos, AF_INET); 1067 } 1068 1069 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1070 { 1071 struct sock *sk; 1072 1073 if (v == SEQ_START_TOKEN) 1074 sk = ping_get_idx(seq, 0); 1075 else 1076 sk = ping_get_next(seq, v); 1077 1078 ++*pos; 1079 return sk; 1080 } 1081 EXPORT_SYMBOL_GPL(ping_seq_next); 1082 1083 void ping_seq_stop(struct seq_file *seq, void *v) 1084 { 1085 read_unlock_bh(&ping_table.lock); 1086 } 1087 EXPORT_SYMBOL_GPL(ping_seq_stop); 1088 1089 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1090 int bucket) 1091 { 1092 struct inet_sock *inet = inet_sk(sp); 1093 __be32 dest = inet->inet_daddr; 1094 __be32 src = inet->inet_rcv_saddr; 1095 __u16 destp = ntohs(inet->inet_dport); 1096 __u16 srcp = ntohs(inet->inet_sport); 1097 1098 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1099 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 1100 bucket, src, srcp, dest, destp, sp->sk_state, 1101 sk_wmem_alloc_get(sp), 1102 sk_rmem_alloc_get(sp), 1103 0, 0L, 0, 1104 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1105 0, sock_i_ino(sp), 1106 atomic_read(&sp->sk_refcnt), sp, 1107 atomic_read(&sp->sk_drops)); 1108 } 1109 1110 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1111 { 1112 seq_setwidth(seq, 127); 1113 if (v == SEQ_START_TOKEN) 1114 seq_puts(seq, " sl local_address rem_address st tx_queue " 1115 "rx_queue tr tm->when retrnsmt uid timeout " 1116 "inode ref pointer drops"); 1117 else { 1118 struct ping_iter_state *state = seq->private; 1119 1120 ping_v4_format_sock(v, seq, state->bucket); 1121 } 1122 seq_pad(seq, '\n'); 1123 return 0; 1124 } 1125 1126 static const struct seq_operations ping_v4_seq_ops = { 1127 .show = ping_v4_seq_show, 1128 .start = ping_v4_seq_start, 1129 .next = ping_seq_next, 1130 .stop = ping_seq_stop, 1131 }; 1132 1133 static int ping_seq_open(struct inode *inode, struct file *file) 1134 { 1135 struct ping_seq_afinfo *afinfo = PDE_DATA(inode); 1136 return seq_open_net(inode, file, &afinfo->seq_ops, 1137 sizeof(struct ping_iter_state)); 1138 } 1139 1140 const struct file_operations ping_seq_fops = { 1141 .open = ping_seq_open, 1142 .read = seq_read, 1143 .llseek = seq_lseek, 1144 .release = seq_release_net, 1145 }; 1146 EXPORT_SYMBOL_GPL(ping_seq_fops); 1147 1148 static struct ping_seq_afinfo ping_v4_seq_afinfo = { 1149 .name = "icmp", 1150 .family = AF_INET, 1151 .seq_fops = &ping_seq_fops, 1152 .seq_ops = { 1153 .start = ping_v4_seq_start, 1154 .show = ping_v4_seq_show, 1155 .next = ping_seq_next, 1156 .stop = ping_seq_stop, 1157 }, 1158 }; 1159 1160 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo) 1161 { 1162 struct proc_dir_entry *p; 1163 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 1164 afinfo->seq_fops, afinfo); 1165 if (!p) 1166 return -ENOMEM; 1167 return 0; 1168 } 1169 EXPORT_SYMBOL_GPL(ping_proc_register); 1170 1171 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo) 1172 { 1173 remove_proc_entry(afinfo->name, net->proc_net); 1174 } 1175 EXPORT_SYMBOL_GPL(ping_proc_unregister); 1176 1177 static int __net_init ping_v4_proc_init_net(struct net *net) 1178 { 1179 return ping_proc_register(net, &ping_v4_seq_afinfo); 1180 } 1181 1182 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1183 { 1184 ping_proc_unregister(net, &ping_v4_seq_afinfo); 1185 } 1186 1187 static struct pernet_operations ping_v4_net_ops = { 1188 .init = ping_v4_proc_init_net, 1189 .exit = ping_v4_proc_exit_net, 1190 }; 1191 1192 int __init ping_proc_init(void) 1193 { 1194 return register_pernet_subsys(&ping_v4_net_ops); 1195 } 1196 1197 void ping_proc_exit(void) 1198 { 1199 unregister_pernet_subsys(&ping_v4_net_ops); 1200 } 1201 1202 #endif 1203 1204 void __init ping_init(void) 1205 { 1206 int i; 1207 1208 for (i = 0; i < PING_HTABLE_SIZE; i++) 1209 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1210 rwlock_init(&ping_table.lock); 1211 } 1212