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 57 struct ping_table ping_table; 58 struct pingv6_ops pingv6_ops; 59 EXPORT_SYMBOL_GPL(pingv6_ops); 60 61 static u16 ping_port_rover; 62 63 static inline int ping_hashfn(struct net *net, unsigned int num, unsigned int mask) 64 { 65 int res = (num + net_hash_mix(net)) & mask; 66 67 pr_debug("hash(%d) = %d\n", num, res); 68 return res; 69 } 70 EXPORT_SYMBOL_GPL(ping_hash); 71 72 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table, 73 struct net *net, unsigned int num) 74 { 75 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)]; 76 } 77 78 int ping_get_port(struct sock *sk, unsigned short ident) 79 { 80 struct hlist_nulls_node *node; 81 struct hlist_nulls_head *hlist; 82 struct inet_sock *isk, *isk2; 83 struct sock *sk2 = NULL; 84 85 isk = inet_sk(sk); 86 write_lock_bh(&ping_table.lock); 87 if (ident == 0) { 88 u32 i; 89 u16 result = ping_port_rover + 1; 90 91 for (i = 0; i < (1L << 16); i++, result++) { 92 if (!result) 93 result++; /* avoid zero */ 94 hlist = ping_hashslot(&ping_table, sock_net(sk), 95 result); 96 ping_portaddr_for_each_entry(sk2, node, hlist) { 97 isk2 = inet_sk(sk2); 98 99 if (isk2->inet_num == result) 100 goto next_port; 101 } 102 103 /* found */ 104 ping_port_rover = ident = result; 105 break; 106 next_port: 107 ; 108 } 109 if (i >= (1L << 16)) 110 goto fail; 111 } else { 112 hlist = ping_hashslot(&ping_table, sock_net(sk), ident); 113 ping_portaddr_for_each_entry(sk2, node, hlist) { 114 isk2 = inet_sk(sk2); 115 116 /* BUG? Why is this reuse and not reuseaddr? ping.c 117 * doesn't turn off SO_REUSEADDR, and it doesn't expect 118 * that other ping processes can steal its packets. 119 */ 120 if ((isk2->inet_num == ident) && 121 (sk2 != sk) && 122 (!sk2->sk_reuse || !sk->sk_reuse)) 123 goto fail; 124 } 125 } 126 127 pr_debug("found port/ident = %d\n", ident); 128 isk->inet_num = ident; 129 if (sk_unhashed(sk)) { 130 pr_debug("was not hashed\n"); 131 sock_hold(sk); 132 hlist_nulls_add_head(&sk->sk_nulls_node, hlist); 133 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 134 } 135 write_unlock_bh(&ping_table.lock); 136 return 0; 137 138 fail: 139 write_unlock_bh(&ping_table.lock); 140 return 1; 141 } 142 EXPORT_SYMBOL_GPL(ping_get_port); 143 144 void ping_hash(struct sock *sk) 145 { 146 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num); 147 BUG(); /* "Please do not press this button again." */ 148 } 149 150 void ping_unhash(struct sock *sk) 151 { 152 struct inet_sock *isk = inet_sk(sk); 153 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); 154 if (sk_hashed(sk)) { 155 write_lock_bh(&ping_table.lock); 156 hlist_nulls_del(&sk->sk_nulls_node); 157 sock_put(sk); 158 isk->inet_num = 0; 159 isk->inet_sport = 0; 160 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 161 write_unlock_bh(&ping_table.lock); 162 } 163 } 164 EXPORT_SYMBOL_GPL(ping_unhash); 165 166 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) 167 { 168 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); 169 struct sock *sk = NULL; 170 struct inet_sock *isk; 171 struct hlist_nulls_node *hnode; 172 int dif = skb->dev->ifindex; 173 174 if (skb->protocol == htons(ETH_P_IP)) { 175 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n", 176 (int)ident, &ip_hdr(skb)->daddr, dif); 177 #if IS_ENABLED(CONFIG_IPV6) 178 } else if (skb->protocol == htons(ETH_P_IPV6)) { 179 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", 180 (int)ident, &ipv6_hdr(skb)->daddr, dif); 181 #endif 182 } 183 184 read_lock_bh(&ping_table.lock); 185 186 ping_portaddr_for_each_entry(sk, hnode, hslot) { 187 isk = inet_sk(sk); 188 189 pr_debug("iterate\n"); 190 if (isk->inet_num != ident) 191 continue; 192 193 if (skb->protocol == htons(ETH_P_IP) && 194 sk->sk_family == AF_INET) { 195 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, 196 (int) isk->inet_num, &isk->inet_rcv_saddr, 197 sk->sk_bound_dev_if); 198 199 if (isk->inet_rcv_saddr && 200 isk->inet_rcv_saddr != ip_hdr(skb)->daddr) 201 continue; 202 #if IS_ENABLED(CONFIG_IPV6) 203 } else if (skb->protocol == htons(ETH_P_IPV6) && 204 sk->sk_family == AF_INET6) { 205 206 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, 207 (int) isk->inet_num, 208 &sk->sk_v6_rcv_saddr, 209 sk->sk_bound_dev_if); 210 211 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 212 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, 213 &ipv6_hdr(skb)->daddr)) 214 continue; 215 #endif 216 } 217 218 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) 219 continue; 220 221 sock_hold(sk); 222 goto exit; 223 } 224 225 sk = NULL; 226 exit: 227 read_unlock_bh(&ping_table.lock); 228 229 return sk; 230 } 231 232 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 233 kgid_t *high) 234 { 235 kgid_t *data = net->ipv4.sysctl_ping_group_range; 236 unsigned int seq; 237 238 do { 239 seq = read_seqbegin(&net->ipv4.sysctl_local_ports.lock); 240 241 *low = data[0]; 242 *high = data[1]; 243 } while (read_seqretry(&net->ipv4.sysctl_local_ports.lock, seq)); 244 } 245 246 247 int ping_init_sock(struct sock *sk) 248 { 249 struct net *net = sock_net(sk); 250 kgid_t group = current_egid(); 251 struct group_info *group_info = get_current_groups(); 252 int i, j, count = group_info->ngroups; 253 kgid_t low, high; 254 255 inet_get_ping_group_range_net(net, &low, &high); 256 if (gid_lte(low, group) && gid_lte(group, high)) 257 return 0; 258 259 for (i = 0; i < group_info->nblocks; i++) { 260 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count); 261 for (j = 0; j < cp_count; j++) { 262 kgid_t gid = group_info->blocks[i][j]; 263 if (gid_lte(low, gid) && gid_lte(gid, high)) 264 return 0; 265 } 266 267 count -= cp_count; 268 } 269 270 return -EACCES; 271 } 272 EXPORT_SYMBOL_GPL(ping_init_sock); 273 274 void ping_close(struct sock *sk, long timeout) 275 { 276 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 277 inet_sk(sk), inet_sk(sk)->inet_num); 278 pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter); 279 280 sk_common_release(sk); 281 } 282 EXPORT_SYMBOL_GPL(ping_close); 283 284 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 285 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 286 struct sockaddr *uaddr, int addr_len) { 287 struct net *net = sock_net(sk); 288 if (sk->sk_family == AF_INET) { 289 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 290 int chk_addr_ret; 291 292 if (addr_len < sizeof(*addr)) 293 return -EINVAL; 294 295 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 296 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 297 298 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); 299 300 if (addr->sin_addr.s_addr == htonl(INADDR_ANY)) 301 chk_addr_ret = RTN_LOCAL; 302 303 if ((sysctl_ip_nonlocal_bind == 0 && 304 isk->freebind == 0 && isk->transparent == 0 && 305 chk_addr_ret != RTN_LOCAL) || 306 chk_addr_ret == RTN_MULTICAST || 307 chk_addr_ret == RTN_BROADCAST) 308 return -EADDRNOTAVAIL; 309 310 #if IS_ENABLED(CONFIG_IPV6) 311 } else if (sk->sk_family == AF_INET6) { 312 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 313 int addr_type, scoped, has_addr; 314 struct net_device *dev = NULL; 315 316 if (addr_len < sizeof(*addr)) 317 return -EINVAL; 318 319 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 320 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 321 322 addr_type = ipv6_addr_type(&addr->sin6_addr); 323 scoped = __ipv6_addr_needs_scope_id(addr_type); 324 if ((addr_type != IPV6_ADDR_ANY && 325 !(addr_type & IPV6_ADDR_UNICAST)) || 326 (scoped && !addr->sin6_scope_id)) 327 return -EINVAL; 328 329 rcu_read_lock(); 330 if (addr->sin6_scope_id) { 331 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 332 if (!dev) { 333 rcu_read_unlock(); 334 return -ENODEV; 335 } 336 } 337 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 338 scoped); 339 rcu_read_unlock(); 340 341 if (!(isk->freebind || isk->transparent || has_addr || 342 addr_type == IPV6_ADDR_ANY)) 343 return -EADDRNOTAVAIL; 344 345 if (scoped) 346 sk->sk_bound_dev_if = addr->sin6_scope_id; 347 #endif 348 } else { 349 return -EAFNOSUPPORT; 350 } 351 return 0; 352 } 353 354 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 355 { 356 if (saddr->sa_family == AF_INET) { 357 struct inet_sock *isk = inet_sk(sk); 358 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 359 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 360 #if IS_ENABLED(CONFIG_IPV6) 361 } else if (saddr->sa_family == AF_INET6) { 362 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 363 struct ipv6_pinfo *np = inet6_sk(sk); 364 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 365 #endif 366 } 367 } 368 369 static void ping_clear_saddr(struct sock *sk, int dif) 370 { 371 sk->sk_bound_dev_if = dif; 372 if (sk->sk_family == AF_INET) { 373 struct inet_sock *isk = inet_sk(sk); 374 isk->inet_rcv_saddr = isk->inet_saddr = 0; 375 #if IS_ENABLED(CONFIG_IPV6) 376 } else if (sk->sk_family == AF_INET6) { 377 struct ipv6_pinfo *np = inet6_sk(sk); 378 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr)); 379 memset(&np->saddr, 0, sizeof(np->saddr)); 380 #endif 381 } 382 } 383 /* 384 * We need our own bind because there are no privileged id's == local ports. 385 * Moreover, we don't allow binding to multi- and broadcast addresses. 386 */ 387 388 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 389 { 390 struct inet_sock *isk = inet_sk(sk); 391 unsigned short snum; 392 int err; 393 int dif = sk->sk_bound_dev_if; 394 395 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 396 if (err) 397 return err; 398 399 lock_sock(sk); 400 401 err = -EINVAL; 402 if (isk->inet_num != 0) 403 goto out; 404 405 err = -EADDRINUSE; 406 ping_set_saddr(sk, uaddr); 407 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 408 if (ping_get_port(sk, snum) != 0) { 409 ping_clear_saddr(sk, dif); 410 goto out; 411 } 412 413 pr_debug("after bind(): num = %d, dif = %d\n", 414 (int)isk->inet_num, 415 (int)sk->sk_bound_dev_if); 416 417 err = 0; 418 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 419 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 420 #if IS_ENABLED(CONFIG_IPV6) 421 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 422 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 423 #endif 424 425 if (snum) 426 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 427 isk->inet_sport = htons(isk->inet_num); 428 isk->inet_daddr = 0; 429 isk->inet_dport = 0; 430 431 #if IS_ENABLED(CONFIG_IPV6) 432 if (sk->sk_family == AF_INET6) 433 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 434 #endif 435 436 sk_dst_reset(sk); 437 out: 438 release_sock(sk); 439 pr_debug("ping_v4_bind -> %d\n", err); 440 return err; 441 } 442 EXPORT_SYMBOL_GPL(ping_bind); 443 444 /* 445 * Is this a supported type of ICMP message? 446 */ 447 448 static inline int ping_supported(int family, int type, int code) 449 { 450 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 451 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0); 452 } 453 454 /* 455 * This routine is called by the ICMP module when it gets some 456 * sort of error condition. 457 */ 458 459 void ping_err(struct sk_buff *skb, int offset, u32 info) 460 { 461 int family; 462 struct icmphdr *icmph; 463 struct inet_sock *inet_sock; 464 int type; 465 int code; 466 struct net *net = dev_net(skb->dev); 467 struct sock *sk; 468 int harderr; 469 int err; 470 471 if (skb->protocol == htons(ETH_P_IP)) { 472 family = AF_INET; 473 type = icmp_hdr(skb)->type; 474 code = icmp_hdr(skb)->code; 475 icmph = (struct icmphdr *)(skb->data + offset); 476 } else if (skb->protocol == htons(ETH_P_IPV6)) { 477 family = AF_INET6; 478 type = icmp6_hdr(skb)->icmp6_type; 479 code = icmp6_hdr(skb)->icmp6_code; 480 icmph = (struct icmphdr *) (skb->data + offset); 481 } else { 482 BUG(); 483 } 484 485 /* We assume the packet has already been checked by icmp_unreach */ 486 487 if (!ping_supported(family, icmph->type, icmph->code)) 488 return; 489 490 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 491 skb->protocol, type, code, ntohs(icmph->un.echo.id), 492 ntohs(icmph->un.echo.sequence)); 493 494 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 495 if (sk == NULL) { 496 pr_debug("no socket, dropping\n"); 497 return; /* No socket for error */ 498 } 499 pr_debug("err on socket %p\n", sk); 500 501 err = 0; 502 harderr = 0; 503 inet_sock = inet_sk(sk); 504 505 if (skb->protocol == htons(ETH_P_IP)) { 506 switch (type) { 507 default: 508 case ICMP_TIME_EXCEEDED: 509 err = EHOSTUNREACH; 510 break; 511 case ICMP_SOURCE_QUENCH: 512 /* This is not a real error but ping wants to see it. 513 * Report it with some fake errno. 514 */ 515 err = EREMOTEIO; 516 break; 517 case ICMP_PARAMETERPROB: 518 err = EPROTO; 519 harderr = 1; 520 break; 521 case ICMP_DEST_UNREACH: 522 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 523 ipv4_sk_update_pmtu(skb, sk, info); 524 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 525 err = EMSGSIZE; 526 harderr = 1; 527 break; 528 } 529 goto out; 530 } 531 err = EHOSTUNREACH; 532 if (code <= NR_ICMP_UNREACH) { 533 harderr = icmp_err_convert[code].fatal; 534 err = icmp_err_convert[code].errno; 535 } 536 break; 537 case ICMP_REDIRECT: 538 /* See ICMP_SOURCE_QUENCH */ 539 ipv4_sk_redirect(skb, sk); 540 err = EREMOTEIO; 541 break; 542 } 543 #if IS_ENABLED(CONFIG_IPV6) 544 } else if (skb->protocol == htons(ETH_P_IPV6)) { 545 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 546 #endif 547 } 548 549 /* 550 * RFC1122: OK. Passes ICMP errors back to application, as per 551 * 4.1.3.3. 552 */ 553 if ((family == AF_INET && !inet_sock->recverr) || 554 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 555 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 556 goto out; 557 } else { 558 if (family == AF_INET) { 559 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 560 info, (u8 *)icmph); 561 #if IS_ENABLED(CONFIG_IPV6) 562 } else if (family == AF_INET6) { 563 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 564 info, (u8 *)icmph); 565 #endif 566 } 567 } 568 sk->sk_err = err; 569 sk->sk_error_report(sk); 570 out: 571 sock_put(sk); 572 } 573 EXPORT_SYMBOL_GPL(ping_err); 574 575 /* 576 * Copy and checksum an ICMP Echo packet from user space into a buffer 577 * starting from the payload. 578 */ 579 580 int ping_getfrag(void *from, char *to, 581 int offset, int fraglen, int odd, struct sk_buff *skb) 582 { 583 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 584 585 if (offset == 0) { 586 if (fraglen < sizeof(struct icmphdr)) 587 BUG(); 588 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr), 589 pfh->iov, 0, fraglen - sizeof(struct icmphdr), 590 &pfh->wcheck)) 591 return -EFAULT; 592 } else if (offset < sizeof(struct icmphdr)) { 593 BUG(); 594 } else { 595 if (csum_partial_copy_fromiovecend 596 (to, pfh->iov, offset - sizeof(struct icmphdr), 597 fraglen, &pfh->wcheck)) 598 return -EFAULT; 599 } 600 601 #if IS_ENABLED(CONFIG_IPV6) 602 /* For IPv6, checksum each skb as we go along, as expected by 603 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 604 * wcheck, it will be finalized in ping_v4_push_pending_frames. 605 */ 606 if (pfh->family == AF_INET6) { 607 skb->csum = pfh->wcheck; 608 skb->ip_summed = CHECKSUM_NONE; 609 pfh->wcheck = 0; 610 } 611 #endif 612 613 return 0; 614 } 615 EXPORT_SYMBOL_GPL(ping_getfrag); 616 617 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 618 struct flowi4 *fl4) 619 { 620 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 621 622 pfh->wcheck = csum_partial((char *)&pfh->icmph, 623 sizeof(struct icmphdr), pfh->wcheck); 624 pfh->icmph.checksum = csum_fold(pfh->wcheck); 625 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 626 skb->ip_summed = CHECKSUM_NONE; 627 return ip_push_pending_frames(sk, fl4); 628 } 629 630 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 631 void *user_icmph, size_t icmph_len) { 632 u8 type, code; 633 634 if (len > 0xFFFF) 635 return -EMSGSIZE; 636 637 /* 638 * Check the flags. 639 */ 640 641 /* Mirror BSD error message compatibility */ 642 if (msg->msg_flags & MSG_OOB) 643 return -EOPNOTSUPP; 644 645 /* 646 * Fetch the ICMP header provided by the userland. 647 * iovec is modified! The ICMP header is consumed. 648 */ 649 if (memcpy_fromiovec(user_icmph, msg->msg_iov, icmph_len)) 650 return -EFAULT; 651 652 if (family == AF_INET) { 653 type = ((struct icmphdr *) user_icmph)->type; 654 code = ((struct icmphdr *) user_icmph)->code; 655 #if IS_ENABLED(CONFIG_IPV6) 656 } else if (family == AF_INET6) { 657 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 658 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 659 #endif 660 } else { 661 BUG(); 662 } 663 664 if (!ping_supported(family, type, code)) 665 return -EINVAL; 666 667 return 0; 668 } 669 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 670 671 int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 672 size_t len) 673 { 674 struct net *net = sock_net(sk); 675 struct flowi4 fl4; 676 struct inet_sock *inet = inet_sk(sk); 677 struct ipcm_cookie ipc; 678 struct icmphdr user_icmph; 679 struct pingfakehdr pfh; 680 struct rtable *rt = NULL; 681 struct ip_options_data opt_copy; 682 int free = 0; 683 __be32 saddr, daddr, faddr; 684 u8 tos; 685 int err; 686 687 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 688 689 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 690 sizeof(user_icmph)); 691 if (err) 692 return err; 693 694 /* 695 * Get and verify the address. 696 */ 697 698 if (msg->msg_name) { 699 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name; 700 if (msg->msg_namelen < sizeof(*usin)) 701 return -EINVAL; 702 if (usin->sin_family != AF_INET) 703 return -EINVAL; 704 daddr = usin->sin_addr.s_addr; 705 /* no remote port */ 706 } else { 707 if (sk->sk_state != TCP_ESTABLISHED) 708 return -EDESTADDRREQ; 709 daddr = inet->inet_daddr; 710 /* no remote port */ 711 } 712 713 ipc.addr = inet->inet_saddr; 714 ipc.opt = NULL; 715 ipc.oif = sk->sk_bound_dev_if; 716 ipc.tx_flags = 0; 717 ipc.ttl = 0; 718 ipc.tos = -1; 719 720 sock_tx_timestamp(sk, &ipc.tx_flags); 721 722 if (msg->msg_controllen) { 723 err = ip_cmsg_send(sock_net(sk), msg, &ipc); 724 if (err) 725 return err; 726 if (ipc.opt) 727 free = 1; 728 } 729 if (!ipc.opt) { 730 struct ip_options_rcu *inet_opt; 731 732 rcu_read_lock(); 733 inet_opt = rcu_dereference(inet->inet_opt); 734 if (inet_opt) { 735 memcpy(&opt_copy, inet_opt, 736 sizeof(*inet_opt) + inet_opt->opt.optlen); 737 ipc.opt = &opt_copy.opt; 738 } 739 rcu_read_unlock(); 740 } 741 742 saddr = ipc.addr; 743 ipc.addr = faddr = daddr; 744 745 if (ipc.opt && ipc.opt->opt.srr) { 746 if (!daddr) 747 return -EINVAL; 748 faddr = ipc.opt->opt.faddr; 749 } 750 tos = get_rttos(&ipc, inet); 751 if (sock_flag(sk, SOCK_LOCALROUTE) || 752 (msg->msg_flags & MSG_DONTROUTE) || 753 (ipc.opt && ipc.opt->opt.is_strictroute)) { 754 tos |= RTO_ONLINK; 755 } 756 757 if (ipv4_is_multicast(daddr)) { 758 if (!ipc.oif) 759 ipc.oif = inet->mc_index; 760 if (!saddr) 761 saddr = inet->mc_addr; 762 } else if (!ipc.oif) 763 ipc.oif = inet->uc_index; 764 765 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos, 766 RT_SCOPE_UNIVERSE, sk->sk_protocol, 767 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0); 768 769 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4)); 770 rt = ip_route_output_flow(net, &fl4, sk); 771 if (IS_ERR(rt)) { 772 err = PTR_ERR(rt); 773 rt = NULL; 774 if (err == -ENETUNREACH) 775 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES); 776 goto out; 777 } 778 779 err = -EACCES; 780 if ((rt->rt_flags & RTCF_BROADCAST) && 781 !sock_flag(sk, SOCK_BROADCAST)) 782 goto out; 783 784 if (msg->msg_flags & MSG_CONFIRM) 785 goto do_confirm; 786 back_from_confirm: 787 788 if (!ipc.addr) 789 ipc.addr = fl4.daddr; 790 791 lock_sock(sk); 792 793 pfh.icmph.type = user_icmph.type; /* already checked */ 794 pfh.icmph.code = user_icmph.code; /* ditto */ 795 pfh.icmph.checksum = 0; 796 pfh.icmph.un.echo.id = inet->inet_sport; 797 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 798 pfh.iov = msg->msg_iov; 799 pfh.wcheck = 0; 800 pfh.family = AF_INET; 801 802 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 803 0, &ipc, &rt, msg->msg_flags); 804 if (err) 805 ip_flush_pending_frames(sk); 806 else 807 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 808 release_sock(sk); 809 810 out: 811 ip_rt_put(rt); 812 if (free) 813 kfree(ipc.opt); 814 if (!err) { 815 icmp_out_count(sock_net(sk), user_icmph.type); 816 return len; 817 } 818 return err; 819 820 do_confirm: 821 dst_confirm(&rt->dst); 822 if (!(msg->msg_flags & MSG_PROBE) || len) 823 goto back_from_confirm; 824 err = 0; 825 goto out; 826 } 827 828 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 829 size_t len, int noblock, int flags, int *addr_len) 830 { 831 struct inet_sock *isk = inet_sk(sk); 832 int family = sk->sk_family; 833 struct sk_buff *skb; 834 int copied, err; 835 836 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 837 838 err = -EOPNOTSUPP; 839 if (flags & MSG_OOB) 840 goto out; 841 842 if (flags & MSG_ERRQUEUE) { 843 if (family == AF_INET) { 844 return ip_recv_error(sk, msg, len); 845 #if IS_ENABLED(CONFIG_IPV6) 846 } else if (family == AF_INET6) { 847 return pingv6_ops.ipv6_recv_error(sk, msg, len); 848 #endif 849 } 850 } 851 852 skb = skb_recv_datagram(sk, flags, noblock, &err); 853 if (!skb) 854 goto out; 855 856 copied = skb->len; 857 if (copied > len) { 858 msg->msg_flags |= MSG_TRUNC; 859 copied = len; 860 } 861 862 /* Don't bother checking the checksum */ 863 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 864 if (err) 865 goto done; 866 867 sock_recv_timestamp(msg, sk, skb); 868 869 /* Copy the address and add cmsg data. */ 870 if (family == AF_INET) { 871 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; 872 873 if (sin) { 874 sin->sin_family = AF_INET; 875 sin->sin_port = 0 /* skb->h.uh->source */; 876 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 877 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 878 *addr_len = sizeof(*sin); 879 } 880 881 if (isk->cmsg_flags) 882 ip_cmsg_recv(msg, skb); 883 884 #if IS_ENABLED(CONFIG_IPV6) 885 } else if (family == AF_INET6) { 886 struct ipv6_pinfo *np = inet6_sk(sk); 887 struct ipv6hdr *ip6 = ipv6_hdr(skb); 888 struct sockaddr_in6 *sin6 = 889 (struct sockaddr_in6 *)msg->msg_name; 890 891 if (sin6) { 892 sin6->sin6_family = AF_INET6; 893 sin6->sin6_port = 0; 894 sin6->sin6_addr = ip6->saddr; 895 sin6->sin6_flowinfo = 0; 896 if (np->sndflow) 897 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 898 sin6->sin6_scope_id = 899 ipv6_iface_scope_id(&sin6->sin6_addr, 900 IP6CB(skb)->iif); 901 *addr_len = sizeof(*sin6); 902 } 903 904 if (inet6_sk(sk)->rxopt.all) 905 pingv6_ops.ip6_datagram_recv_ctl(sk, msg, skb); 906 #endif 907 } else { 908 BUG(); 909 } 910 911 err = copied; 912 913 done: 914 skb_free_datagram(sk, skb); 915 out: 916 pr_debug("ping_recvmsg -> %d\n", err); 917 return err; 918 } 919 EXPORT_SYMBOL_GPL(ping_recvmsg); 920 921 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 922 { 923 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 924 inet_sk(sk), inet_sk(sk)->inet_num, skb); 925 if (sock_queue_rcv_skb(sk, skb) < 0) { 926 kfree_skb(skb); 927 pr_debug("ping_queue_rcv_skb -> failed\n"); 928 return -1; 929 } 930 return 0; 931 } 932 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 933 934 935 /* 936 * All we need to do is get the socket. 937 */ 938 939 void ping_rcv(struct sk_buff *skb) 940 { 941 struct sock *sk; 942 struct net *net = dev_net(skb->dev); 943 struct icmphdr *icmph = icmp_hdr(skb); 944 945 /* We assume the packet has already been checked by icmp_rcv */ 946 947 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 948 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 949 950 /* Push ICMP header back */ 951 skb_push(skb, skb->data - (u8 *)icmph); 952 953 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 954 if (sk != NULL) { 955 pr_debug("rcv on socket %p\n", sk); 956 ping_queue_rcv_skb(sk, skb_get(skb)); 957 sock_put(sk); 958 return; 959 } 960 pr_debug("no socket, dropping\n"); 961 962 /* We're called from icmp_rcv(). kfree_skb() is done there. */ 963 } 964 EXPORT_SYMBOL_GPL(ping_rcv); 965 966 struct proto ping_prot = { 967 .name = "PING", 968 .owner = THIS_MODULE, 969 .init = ping_init_sock, 970 .close = ping_close, 971 .connect = ip4_datagram_connect, 972 .disconnect = udp_disconnect, 973 .setsockopt = ip_setsockopt, 974 .getsockopt = ip_getsockopt, 975 .sendmsg = ping_v4_sendmsg, 976 .recvmsg = ping_recvmsg, 977 .bind = ping_bind, 978 .backlog_rcv = ping_queue_rcv_skb, 979 .release_cb = ip4_datagram_release_cb, 980 .hash = ping_hash, 981 .unhash = ping_unhash, 982 .get_port = ping_get_port, 983 .obj_size = sizeof(struct inet_sock), 984 }; 985 EXPORT_SYMBOL(ping_prot); 986 987 #ifdef CONFIG_PROC_FS 988 989 static struct sock *ping_get_first(struct seq_file *seq, int start) 990 { 991 struct sock *sk; 992 struct ping_iter_state *state = seq->private; 993 struct net *net = seq_file_net(seq); 994 995 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 996 ++state->bucket) { 997 struct hlist_nulls_node *node; 998 struct hlist_nulls_head *hslot; 999 1000 hslot = &ping_table.hash[state->bucket]; 1001 1002 if (hlist_nulls_empty(hslot)) 1003 continue; 1004 1005 sk_nulls_for_each(sk, node, hslot) { 1006 if (net_eq(sock_net(sk), net) && 1007 sk->sk_family == state->family) 1008 goto found; 1009 } 1010 } 1011 sk = NULL; 1012 found: 1013 return sk; 1014 } 1015 1016 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1017 { 1018 struct ping_iter_state *state = seq->private; 1019 struct net *net = seq_file_net(seq); 1020 1021 do { 1022 sk = sk_nulls_next(sk); 1023 } while (sk && (!net_eq(sock_net(sk), net))); 1024 1025 if (!sk) 1026 return ping_get_first(seq, state->bucket + 1); 1027 return sk; 1028 } 1029 1030 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1031 { 1032 struct sock *sk = ping_get_first(seq, 0); 1033 1034 if (sk) 1035 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1036 --pos; 1037 return pos ? NULL : sk; 1038 } 1039 1040 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1041 { 1042 struct ping_iter_state *state = seq->private; 1043 state->bucket = 0; 1044 state->family = family; 1045 1046 read_lock_bh(&ping_table.lock); 1047 1048 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1049 } 1050 EXPORT_SYMBOL_GPL(ping_seq_start); 1051 1052 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1053 { 1054 return ping_seq_start(seq, pos, AF_INET); 1055 } 1056 1057 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1058 { 1059 struct sock *sk; 1060 1061 if (v == SEQ_START_TOKEN) 1062 sk = ping_get_idx(seq, 0); 1063 else 1064 sk = ping_get_next(seq, v); 1065 1066 ++*pos; 1067 return sk; 1068 } 1069 EXPORT_SYMBOL_GPL(ping_seq_next); 1070 1071 void ping_seq_stop(struct seq_file *seq, void *v) 1072 { 1073 read_unlock_bh(&ping_table.lock); 1074 } 1075 EXPORT_SYMBOL_GPL(ping_seq_stop); 1076 1077 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1078 int bucket) 1079 { 1080 struct inet_sock *inet = inet_sk(sp); 1081 __be32 dest = inet->inet_daddr; 1082 __be32 src = inet->inet_rcv_saddr; 1083 __u16 destp = ntohs(inet->inet_dport); 1084 __u16 srcp = ntohs(inet->inet_sport); 1085 1086 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1087 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d", 1088 bucket, src, srcp, dest, destp, sp->sk_state, 1089 sk_wmem_alloc_get(sp), 1090 sk_rmem_alloc_get(sp), 1091 0, 0L, 0, 1092 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1093 0, sock_i_ino(sp), 1094 atomic_read(&sp->sk_refcnt), sp, 1095 atomic_read(&sp->sk_drops)); 1096 } 1097 1098 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1099 { 1100 seq_setwidth(seq, 127); 1101 if (v == SEQ_START_TOKEN) 1102 seq_puts(seq, " sl local_address rem_address st tx_queue " 1103 "rx_queue tr tm->when retrnsmt uid timeout " 1104 "inode ref pointer drops"); 1105 else { 1106 struct ping_iter_state *state = seq->private; 1107 1108 ping_v4_format_sock(v, seq, state->bucket); 1109 } 1110 seq_pad(seq, '\n'); 1111 return 0; 1112 } 1113 1114 static const struct seq_operations ping_v4_seq_ops = { 1115 .show = ping_v4_seq_show, 1116 .start = ping_v4_seq_start, 1117 .next = ping_seq_next, 1118 .stop = ping_seq_stop, 1119 }; 1120 1121 static int ping_seq_open(struct inode *inode, struct file *file) 1122 { 1123 struct ping_seq_afinfo *afinfo = PDE_DATA(inode); 1124 return seq_open_net(inode, file, &afinfo->seq_ops, 1125 sizeof(struct ping_iter_state)); 1126 } 1127 1128 const struct file_operations ping_seq_fops = { 1129 .open = ping_seq_open, 1130 .read = seq_read, 1131 .llseek = seq_lseek, 1132 .release = seq_release_net, 1133 }; 1134 EXPORT_SYMBOL_GPL(ping_seq_fops); 1135 1136 static struct ping_seq_afinfo ping_v4_seq_afinfo = { 1137 .name = "icmp", 1138 .family = AF_INET, 1139 .seq_fops = &ping_seq_fops, 1140 .seq_ops = { 1141 .start = ping_v4_seq_start, 1142 .show = ping_v4_seq_show, 1143 .next = ping_seq_next, 1144 .stop = ping_seq_stop, 1145 }, 1146 }; 1147 1148 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo) 1149 { 1150 struct proc_dir_entry *p; 1151 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, 1152 afinfo->seq_fops, afinfo); 1153 if (!p) 1154 return -ENOMEM; 1155 return 0; 1156 } 1157 EXPORT_SYMBOL_GPL(ping_proc_register); 1158 1159 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo) 1160 { 1161 remove_proc_entry(afinfo->name, net->proc_net); 1162 } 1163 EXPORT_SYMBOL_GPL(ping_proc_unregister); 1164 1165 static int __net_init ping_v4_proc_init_net(struct net *net) 1166 { 1167 return ping_proc_register(net, &ping_v4_seq_afinfo); 1168 } 1169 1170 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1171 { 1172 ping_proc_unregister(net, &ping_v4_seq_afinfo); 1173 } 1174 1175 static struct pernet_operations ping_v4_net_ops = { 1176 .init = ping_v4_proc_init_net, 1177 .exit = ping_v4_proc_exit_net, 1178 }; 1179 1180 int __init ping_proc_init(void) 1181 { 1182 return register_pernet_subsys(&ping_v4_net_ops); 1183 } 1184 1185 void ping_proc_exit(void) 1186 { 1187 unregister_pernet_subsys(&ping_v4_net_ops); 1188 } 1189 1190 #endif 1191 1192 void __init ping_init(void) 1193 { 1194 int i; 1195 1196 for (i = 0; i < PING_HTABLE_SIZE; i++) 1197 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1198 rwlock_init(&ping_table.lock); 1199 } 1200