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 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 324 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 325 326 addr_type = ipv6_addr_type(&addr->sin6_addr); 327 scoped = __ipv6_addr_needs_scope_id(addr_type); 328 if ((addr_type != IPV6_ADDR_ANY && 329 !(addr_type & IPV6_ADDR_UNICAST)) || 330 (scoped && !addr->sin6_scope_id)) 331 return -EINVAL; 332 333 rcu_read_lock(); 334 if (addr->sin6_scope_id) { 335 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 336 if (!dev) { 337 rcu_read_unlock(); 338 return -ENODEV; 339 } 340 } 341 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 342 scoped); 343 rcu_read_unlock(); 344 345 if (!(isk->freebind || isk->transparent || has_addr || 346 addr_type == IPV6_ADDR_ANY)) 347 return -EADDRNOTAVAIL; 348 349 if (scoped) 350 sk->sk_bound_dev_if = addr->sin6_scope_id; 351 #endif 352 } else { 353 return -EAFNOSUPPORT; 354 } 355 return 0; 356 } 357 358 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 359 { 360 if (saddr->sa_family == AF_INET) { 361 struct inet_sock *isk = inet_sk(sk); 362 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 363 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 364 #if IS_ENABLED(CONFIG_IPV6) 365 } else if (saddr->sa_family == AF_INET6) { 366 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 367 struct ipv6_pinfo *np = inet6_sk(sk); 368 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 369 #endif 370 } 371 } 372 373 static void ping_clear_saddr(struct sock *sk, int dif) 374 { 375 sk->sk_bound_dev_if = dif; 376 if (sk->sk_family == AF_INET) { 377 struct inet_sock *isk = inet_sk(sk); 378 isk->inet_rcv_saddr = isk->inet_saddr = 0; 379 #if IS_ENABLED(CONFIG_IPV6) 380 } else if (sk->sk_family == AF_INET6) { 381 struct ipv6_pinfo *np = inet6_sk(sk); 382 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 383 memset(&np->saddr, 0, sizeof(np->saddr)); 384 #endif 385 } 386 } 387 /* 388 * We need our own bind because there are no privileged id's == local ports. 389 * Moreover, we don't allow binding to multi- and broadcast addresses. 390 */ 391 392 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 393 { 394 struct inet_sock *isk = inet_sk(sk); 395 unsigned short snum; 396 int err; 397 int dif = sk->sk_bound_dev_if; 398 399 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 400 if (err) 401 return err; 402 403 lock_sock(sk); 404 405 err = -EINVAL; 406 if (isk->inet_num != 0) 407 goto out; 408 409 err = -EADDRINUSE; 410 ping_set_saddr(sk, uaddr); 411 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 412 if (ping_get_port(sk, snum) != 0) { 413 ping_clear_saddr(sk, dif); 414 goto out; 415 } 416 417 pr_debug("after bind(): num = %d, dif = %d\n", 418 (int)isk->inet_num, 419 (int)sk->sk_bound_dev_if); 420 421 err = 0; 422 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 423 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 424 #if IS_ENABLED(CONFIG_IPV6) 425 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 426 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 427 #endif 428 429 if (snum) 430 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 431 isk->inet_sport = htons(isk->inet_num); 432 isk->inet_daddr = 0; 433 isk->inet_dport = 0; 434 435 #if IS_ENABLED(CONFIG_IPV6) 436 if (sk->sk_family == AF_INET6) 437 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 438 #endif 439 440 sk_dst_reset(sk); 441 out: 442 release_sock(sk); 443 pr_debug("ping_v4_bind -> %d\n", err); 444 return err; 445 } 446 EXPORT_SYMBOL_GPL(ping_bind); 447 448 /* 449 * Is this a supported type of ICMP message? 450 */ 451 452 static inline int ping_supported(int family, int type, int code) 453 { 454 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 455 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0); 456 } 457 458 /* 459 * This routine is called by the ICMP module when it gets some 460 * sort of error condition. 461 */ 462 463 void ping_err(struct sk_buff *skb, int offset, u32 info) 464 { 465 int family; 466 struct icmphdr *icmph; 467 struct inet_sock *inet_sock; 468 int type; 469 int code; 470 struct net *net = dev_net(skb->dev); 471 struct sock *sk; 472 int harderr; 473 int err; 474 475 if (skb->protocol == htons(ETH_P_IP)) { 476 family = AF_INET; 477 type = icmp_hdr(skb)->type; 478 code = icmp_hdr(skb)->code; 479 icmph = (struct icmphdr *)(skb->data + offset); 480 } else if (skb->protocol == htons(ETH_P_IPV6)) { 481 family = AF_INET6; 482 type = icmp6_hdr(skb)->icmp6_type; 483 code = icmp6_hdr(skb)->icmp6_code; 484 icmph = (struct icmphdr *) (skb->data + offset); 485 } else { 486 BUG(); 487 } 488 489 /* We assume the packet has already been checked by icmp_unreach */ 490 491 if (!ping_supported(family, icmph->type, icmph->code)) 492 return; 493 494 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 495 skb->protocol, type, code, ntohs(icmph->un.echo.id), 496 ntohs(icmph->un.echo.sequence)); 497 498 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 499 if (sk == NULL) { 500 pr_debug("no socket, dropping\n"); 501 return; /* No socket for error */ 502 } 503 pr_debug("err on socket %p\n", sk); 504 505 err = 0; 506 harderr = 0; 507 inet_sock = inet_sk(sk); 508 509 if (skb->protocol == htons(ETH_P_IP)) { 510 switch (type) { 511 default: 512 case ICMP_TIME_EXCEEDED: 513 err = EHOSTUNREACH; 514 break; 515 case ICMP_SOURCE_QUENCH: 516 /* This is not a real error but ping wants to see it. 517 * Report it with some fake errno. 518 */ 519 err = EREMOTEIO; 520 break; 521 case ICMP_PARAMETERPROB: 522 err = EPROTO; 523 harderr = 1; 524 break; 525 case ICMP_DEST_UNREACH: 526 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 527 ipv4_sk_update_pmtu(skb, sk, info); 528 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 529 err = EMSGSIZE; 530 harderr = 1; 531 break; 532 } 533 goto out; 534 } 535 err = EHOSTUNREACH; 536 if (code <= NR_ICMP_UNREACH) { 537 harderr = icmp_err_convert[code].fatal; 538 err = icmp_err_convert[code].errno; 539 } 540 break; 541 case ICMP_REDIRECT: 542 /* See ICMP_SOURCE_QUENCH */ 543 ipv4_sk_redirect(skb, sk); 544 err = EREMOTEIO; 545 break; 546 } 547 #if IS_ENABLED(CONFIG_IPV6) 548 } else if (skb->protocol == htons(ETH_P_IPV6)) { 549 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 550 #endif 551 } 552 553 /* 554 * RFC1122: OK. Passes ICMP errors back to application, as per 555 * 4.1.3.3. 556 */ 557 if ((family == AF_INET && !inet_sock->recverr) || 558 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 559 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 560 goto out; 561 } else { 562 if (family == AF_INET) { 563 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 564 info, (u8 *)icmph); 565 #if IS_ENABLED(CONFIG_IPV6) 566 } else if (family == AF_INET6) { 567 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 568 info, (u8 *)icmph); 569 #endif 570 } 571 } 572 sk->sk_err = err; 573 sk->sk_error_report(sk); 574 out: 575 sock_put(sk); 576 } 577 EXPORT_SYMBOL_GPL(ping_err); 578 579 /* 580 * Copy and checksum an ICMP Echo packet from user space into a buffer 581 * starting from the payload. 582 */ 583 584 int ping_getfrag(void *from, char *to, 585 int offset, int fraglen, int odd, struct sk_buff *skb) 586 { 587 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 588 589 if (offset == 0) { 590 if (fraglen < sizeof(struct icmphdr)) 591 BUG(); 592 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr), 593 pfh->iov, 0, fraglen - sizeof(struct icmphdr), 594 &pfh->wcheck)) 595 return -EFAULT; 596 } else if (offset < sizeof(struct icmphdr)) { 597 BUG(); 598 } else { 599 if (csum_partial_copy_fromiovecend 600 (to, pfh->iov, offset - sizeof(struct icmphdr), 601 fraglen, &pfh->wcheck)) 602 return -EFAULT; 603 } 604 605 #if IS_ENABLED(CONFIG_IPV6) 606 /* For IPv6, checksum each skb as we go along, as expected by 607 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 608 * wcheck, it will be finalized in ping_v4_push_pending_frames. 609 */ 610 if (pfh->family == AF_INET6) { 611 skb->csum = pfh->wcheck; 612 skb->ip_summed = CHECKSUM_NONE; 613 pfh->wcheck = 0; 614 } 615 #endif 616 617 return 0; 618 } 619 EXPORT_SYMBOL_GPL(ping_getfrag); 620 621 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 622 struct flowi4 *fl4) 623 { 624 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 625 626 pfh->wcheck = csum_partial((char *)&pfh->icmph, 627 sizeof(struct icmphdr), pfh->wcheck); 628 pfh->icmph.checksum = csum_fold(pfh->wcheck); 629 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 630 skb->ip_summed = CHECKSUM_NONE; 631 return ip_push_pending_frames(sk, fl4); 632 } 633 634 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 635 void *user_icmph, size_t icmph_len) { 636 u8 type, code; 637 638 if (len > 0xFFFF) 639 return -EMSGSIZE; 640 641 /* 642 * Check the flags. 643 */ 644 645 /* Mirror BSD error message compatibility */ 646 if (msg->msg_flags & MSG_OOB) 647 return -EOPNOTSUPP; 648 649 /* 650 * Fetch the ICMP header provided by the userland. 651 * iovec is modified! The ICMP header is consumed. 652 */ 653 if (memcpy_fromiovec(user_icmph, msg->msg_iov, icmph_len)) 654 return -EFAULT; 655 656 if (family == AF_INET) { 657 type = ((struct icmphdr *) user_icmph)->type; 658 code = ((struct icmphdr *) user_icmph)->code; 659 #if IS_ENABLED(CONFIG_IPV6) 660 } else if (family == AF_INET6) { 661 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 662 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 663 #endif 664 } else { 665 BUG(); 666 } 667 668 if (!ping_supported(family, type, code)) 669 return -EINVAL; 670 671 return 0; 672 } 673 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 674 675 static int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 676 size_t len) 677 { 678 struct net *net = sock_net(sk); 679 struct flowi4 fl4; 680 struct inet_sock *inet = inet_sk(sk); 681 struct ipcm_cookie ipc; 682 struct icmphdr user_icmph; 683 struct pingfakehdr pfh; 684 struct rtable *rt = NULL; 685 struct ip_options_data opt_copy; 686 int free = 0; 687 __be32 saddr, daddr, faddr; 688 u8 tos; 689 int err; 690 691 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 692 693 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 694 sizeof(user_icmph)); 695 if (err) 696 return err; 697 698 /* 699 * Get and verify the address. 700 */ 701 702 if (msg->msg_name) { 703 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name; 704 if (msg->msg_namelen < sizeof(*usin)) 705 return -EINVAL; 706 if (usin->sin_family != AF_INET) 707 return -EINVAL; 708 daddr = usin->sin_addr.s_addr; 709 /* no remote port */ 710 } else { 711 if (sk->sk_state != TCP_ESTABLISHED) 712 return -EDESTADDRREQ; 713 daddr = inet->inet_daddr; 714 /* no remote port */ 715 } 716 717 ipc.addr = inet->inet_saddr; 718 ipc.opt = NULL; 719 ipc.oif = sk->sk_bound_dev_if; 720 ipc.tx_flags = 0; 721 ipc.ttl = 0; 722 ipc.tos = -1; 723 724 sock_tx_timestamp(sk, &ipc.tx_flags); 725 726 if (msg->msg_controllen) { 727 err = ip_cmsg_send(sock_net(sk), msg, &ipc); 728 if (err) 729 return err; 730 if (ipc.opt) 731 free = 1; 732 } 733 if (!ipc.opt) { 734 struct ip_options_rcu *inet_opt; 735 736 rcu_read_lock(); 737 inet_opt = rcu_dereference(inet->inet_opt); 738 if (inet_opt) { 739 memcpy(&opt_copy, inet_opt, 740 sizeof(*inet_opt) + inet_opt->opt.optlen); 741 ipc.opt = &opt_copy.opt; 742 } 743 rcu_read_unlock(); 744 } 745 746 saddr = ipc.addr; 747 ipc.addr = faddr = daddr; 748 749 if (ipc.opt && ipc.opt->opt.srr) { 750 if (!daddr) 751 return -EINVAL; 752 faddr = ipc.opt->opt.faddr; 753 } 754 tos = get_rttos(&ipc, inet); 755 if (sock_flag(sk, SOCK_LOCALROUTE) || 756 (msg->msg_flags & MSG_DONTROUTE) || 757 (ipc.opt && ipc.opt->opt.is_strictroute)) { 758 tos |= RTO_ONLINK; 759 } 760 761 if (ipv4_is_multicast(daddr)) { 762 if (!ipc.oif) 763 ipc.oif = inet->mc_index; 764 if (!saddr) 765 saddr = inet->mc_addr; 766 } else if (!ipc.oif) 767 ipc.oif = inet->uc_index; 768 769 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos, 770 RT_SCOPE_UNIVERSE, sk->sk_protocol, 771 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0); 772 773 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 774 rt = ip_route_output_flow(net, &fl4, sk); 775 if (IS_ERR(rt)) { 776 err = PTR_ERR(rt); 777 rt = NULL; 778 if (err == -ENETUNREACH) 779 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 780 goto out; 781 } 782 783 err = -EACCES; 784 if ((rt->rt_flags & RTCF_BROADCAST) && 785 !sock_flag(sk, SOCK_BROADCAST)) 786 goto out; 787 788 if (msg->msg_flags & MSG_CONFIRM) 789 goto do_confirm; 790 back_from_confirm: 791 792 if (!ipc.addr) 793 ipc.addr = fl4.daddr; 794 795 lock_sock(sk); 796 797 pfh.icmph.type = user_icmph.type; /* already checked */ 798 pfh.icmph.code = user_icmph.code; /* ditto */ 799 pfh.icmph.checksum = 0; 800 pfh.icmph.un.echo.id = inet->inet_sport; 801 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 802 pfh.iov = msg->msg_iov; 803 pfh.wcheck = 0; 804 pfh.family = AF_INET; 805 806 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 807 0, &ipc, &rt, msg->msg_flags); 808 if (err) 809 ip_flush_pending_frames(sk); 810 else 811 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 812 release_sock(sk); 813 814 out: 815 ip_rt_put(rt); 816 if (free) 817 kfree(ipc.opt); 818 if (!err) { 819 icmp_out_count(sock_net(sk), user_icmph.type); 820 return len; 821 } 822 return err; 823 824 do_confirm: 825 dst_confirm(&rt->dst); 826 if (!(msg->msg_flags & MSG_PROBE) || len) 827 goto back_from_confirm; 828 err = 0; 829 goto out; 830 } 831 832 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 833 size_t len, int noblock, int flags, int *addr_len) 834 { 835 struct inet_sock *isk = inet_sk(sk); 836 int family = sk->sk_family; 837 struct sk_buff *skb; 838 int copied, err; 839 840 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 841 842 err = -EOPNOTSUPP; 843 if (flags & MSG_OOB) 844 goto out; 845 846 if (flags & MSG_ERRQUEUE) { 847 if (family == AF_INET) { 848 return ip_recv_error(sk, msg, len, addr_len); 849 #if IS_ENABLED(CONFIG_IPV6) 850 } else if (family == AF_INET6) { 851 return pingv6_ops.ipv6_recv_error(sk, msg, len, 852 addr_len); 853 #endif 854 } 855 } 856 857 skb = skb_recv_datagram(sk, flags, noblock, &err); 858 if (!skb) 859 goto out; 860 861 copied = skb->len; 862 if (copied > len) { 863 msg->msg_flags |= MSG_TRUNC; 864 copied = len; 865 } 866 867 /* Don't bother checking the checksum */ 868 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 869 if (err) 870 goto done; 871 872 sock_recv_timestamp(msg, sk, skb); 873 874 /* Copy the address and add cmsg data. */ 875 if (family == AF_INET) { 876 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 877 878 if (sin) { 879 sin->sin_family = AF_INET; 880 sin->sin_port = 0 /* skb->h.uh->source */; 881 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 882 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 883 *addr_len = sizeof(*sin); 884 } 885 886 if (isk->cmsg_flags) 887 ip_cmsg_recv(msg, skb); 888 889 #if IS_ENABLED(CONFIG_IPV6) 890 } else if (family == AF_INET6) { 891 struct ipv6_pinfo *np = inet6_sk(sk); 892 struct ipv6hdr *ip6 = ipv6_hdr(skb); 893 struct sockaddr_in6 *sin6 = 894 (struct sockaddr_in6 *)msg->msg_name; 895 896 if (sin6) { 897 sin6->sin6_family = AF_INET6; 898 sin6->sin6_port = 0; 899 sin6->sin6_addr = ip6->saddr; 900 sin6->sin6_flowinfo = 0; 901 if (np->sndflow) 902 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 903 sin6->sin6_scope_id = 904 ipv6_iface_scope_id(&sin6->sin6_addr, 905 IP6CB(skb)->iif); 906 *addr_len = sizeof(*sin6); 907 } 908 909 if (inet6_sk(sk)->rxopt.all) 910 pingv6_ops.ip6_datagram_recv_ctl(sk, msg, skb); 911 #endif 912 } else { 913 BUG(); 914 } 915 916 err = copied; 917 918 done: 919 skb_free_datagram(sk, skb); 920 out: 921 pr_debug("ping_recvmsg -> %d\n", err); 922 return err; 923 } 924 EXPORT_SYMBOL_GPL(ping_recvmsg); 925 926 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 927 { 928 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 929 inet_sk(sk), inet_sk(sk)->inet_num, skb); 930 if (sock_queue_rcv_skb(sk, skb) < 0) { 931 kfree_skb(skb); 932 pr_debug("ping_queue_rcv_skb -> failed\n"); 933 return -1; 934 } 935 return 0; 936 } 937 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 938 939 940 /* 941 * All we need to do is get the socket. 942 */ 943 944 void ping_rcv(struct sk_buff *skb) 945 { 946 struct sock *sk; 947 struct net *net = dev_net(skb->dev); 948 struct icmphdr *icmph = icmp_hdr(skb); 949 950 /* We assume the packet has already been checked by icmp_rcv */ 951 952 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 953 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 954 955 /* Push ICMP header back */ 956 skb_push(skb, skb->data - (u8 *)icmph); 957 958 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 959 if (sk != NULL) { 960 pr_debug("rcv on socket %p\n", sk); 961 ping_queue_rcv_skb(sk, skb_get(skb)); 962 sock_put(sk); 963 return; 964 } 965 pr_debug("no socket, dropping\n"); 966 967 /* We're called from icmp_rcv(). kfree_skb() is done there. */ 968 } 969 EXPORT_SYMBOL_GPL(ping_rcv); 970 971 struct proto ping_prot = { 972 .name = "PING", 973 .owner = THIS_MODULE, 974 .init = ping_init_sock, 975 .close = ping_close, 976 .connect = ip4_datagram_connect, 977 .disconnect = udp_disconnect, 978 .setsockopt = ip_setsockopt, 979 .getsockopt = ip_getsockopt, 980 .sendmsg = ping_v4_sendmsg, 981 .recvmsg = ping_recvmsg, 982 .bind = ping_bind, 983 .backlog_rcv = ping_queue_rcv_skb, 984 .release_cb = ip4_datagram_release_cb, 985 .hash = ping_hash, 986 .unhash = ping_unhash, 987 .get_port = ping_get_port, 988 .obj_size = sizeof(struct inet_sock), 989 }; 990 EXPORT_SYMBOL(ping_prot); 991 992 #ifdef CONFIG_PROC_FS 993 994 static struct sock *ping_get_first(struct seq_file *seq, int start) 995 { 996 struct sock *sk; 997 struct ping_iter_state *state = seq->private; 998 struct net *net = seq_file_net(seq); 999 1000 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1001 ++state->bucket) { 1002 struct hlist_nulls_node *node; 1003 struct hlist_nulls_head *hslot; 1004 1005 hslot = &ping_table.hash[state->bucket]; 1006 1007 if (hlist_nulls_empty(hslot)) 1008 continue; 1009 1010 sk_nulls_for_each(sk, node, hslot) { 1011 if (net_eq(sock_net(sk), net) && 1012 sk->sk_family == state->family) 1013 goto found; 1014 } 1015 } 1016 sk = NULL; 1017 found: 1018 return sk; 1019 } 1020 1021 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1022 { 1023 struct ping_iter_state *state = seq->private; 1024 struct net *net = seq_file_net(seq); 1025 1026 do { 1027 sk = sk_nulls_next(sk); 1028 } while (sk && (!net_eq(sock_net(sk), net))); 1029 1030 if (!sk) 1031 return ping_get_first(seq, state->bucket + 1); 1032 return sk; 1033 } 1034 1035 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1036 { 1037 struct sock *sk = ping_get_first(seq, 0); 1038 1039 if (sk) 1040 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1041 --pos; 1042 return pos ? NULL : sk; 1043 } 1044 1045 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1046 { 1047 struct ping_iter_state *state = seq->private; 1048 state->bucket = 0; 1049 state->family = family; 1050 1051 read_lock_bh(&ping_table.lock); 1052 1053 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1054 } 1055 EXPORT_SYMBOL_GPL(ping_seq_start); 1056 1057 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1058 { 1059 return ping_seq_start(seq, pos, AF_INET); 1060 } 1061 1062 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1063 { 1064 struct sock *sk; 1065 1066 if (v == SEQ_START_TOKEN) 1067 sk = ping_get_idx(seq, 0); 1068 else 1069 sk = ping_get_next(seq, v); 1070 1071 ++*pos; 1072 return sk; 1073 } 1074 EXPORT_SYMBOL_GPL(ping_seq_next); 1075 1076 void ping_seq_stop(struct seq_file *seq, void *v) 1077 { 1078 read_unlock_bh(&ping_table.lock); 1079 } 1080 EXPORT_SYMBOL_GPL(ping_seq_stop); 1081 1082 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1083 int bucket) 1084 { 1085 struct inet_sock *inet = inet_sk(sp); 1086 __be32 dest = inet->inet_daddr; 1087 __be32 src = inet->inet_rcv_saddr; 1088 __u16 destp = ntohs(inet->inet_dport); 1089 __u16 srcp = ntohs(inet->inet_sport); 1090 1091 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1092 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 1093 bucket, src, srcp, dest, destp, sp->sk_state, 1094 sk_wmem_alloc_get(sp), 1095 sk_rmem_alloc_get(sp), 1096 0, 0L, 0, 1097 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1098 0, sock_i_ino(sp), 1099 atomic_read(&sp->sk_refcnt), sp, 1100 atomic_read(&sp->sk_drops)); 1101 } 1102 1103 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1104 { 1105 seq_setwidth(seq, 127); 1106 if (v == SEQ_START_TOKEN) 1107 seq_puts(seq, " sl local_address rem_address st tx_queue " 1108 "rx_queue tr tm->when retrnsmt uid timeout " 1109 "inode ref pointer drops"); 1110 else { 1111 struct ping_iter_state *state = seq->private; 1112 1113 ping_v4_format_sock(v, seq, state->bucket); 1114 } 1115 seq_pad(seq, '\n'); 1116 return 0; 1117 } 1118 1119 static const struct seq_operations ping_v4_seq_ops = { 1120 .show = ping_v4_seq_show, 1121 .start = ping_v4_seq_start, 1122 .next = ping_seq_next, 1123 .stop = ping_seq_stop, 1124 }; 1125 1126 static int ping_seq_open(struct inode *inode, struct file *file) 1127 { 1128 struct ping_seq_afinfo *afinfo = PDE_DATA(inode); 1129 return seq_open_net(inode, file, &afinfo->seq_ops, 1130 sizeof(struct ping_iter_state)); 1131 } 1132 1133 const struct file_operations ping_seq_fops = { 1134 .open = ping_seq_open, 1135 .read = seq_read, 1136 .llseek = seq_lseek, 1137 .release = seq_release_net, 1138 }; 1139 EXPORT_SYMBOL_GPL(ping_seq_fops); 1140 1141 static struct ping_seq_afinfo ping_v4_seq_afinfo = { 1142 .name = "icmp", 1143 .family = AF_INET, 1144 .seq_fops = &ping_seq_fops, 1145 .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 1153 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo) 1154 { 1155 struct proc_dir_entry *p; 1156 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 1157 afinfo->seq_fops, afinfo); 1158 if (!p) 1159 return -ENOMEM; 1160 return 0; 1161 } 1162 EXPORT_SYMBOL_GPL(ping_proc_register); 1163 1164 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo) 1165 { 1166 remove_proc_entry(afinfo->name, net->proc_net); 1167 } 1168 EXPORT_SYMBOL_GPL(ping_proc_unregister); 1169 1170 static int __net_init ping_v4_proc_init_net(struct net *net) 1171 { 1172 return ping_proc_register(net, &ping_v4_seq_afinfo); 1173 } 1174 1175 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1176 { 1177 ping_proc_unregister(net, &ping_v4_seq_afinfo); 1178 } 1179 1180 static struct pernet_operations ping_v4_net_ops = { 1181 .init = ping_v4_proc_init_net, 1182 .exit = ping_v4_proc_exit_net, 1183 }; 1184 1185 int __init ping_proc_init(void) 1186 { 1187 return register_pernet_subsys(&ping_v4_net_ops); 1188 } 1189 1190 void ping_proc_exit(void) 1191 { 1192 unregister_pernet_subsys(&ping_v4_net_ops); 1193 } 1194 1195 #endif 1196 1197 void __init ping_init(void) 1198 { 1199 int i; 1200 1201 for (i = 0; i < PING_HTABLE_SIZE; i++) 1202 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1203 rwlock_init(&ping_table.lock); 1204 } 1205