1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * "Ping" sockets 8 * 9 * Based on ipv4/udp.c code. 10 * 11 * Authors: Vasiliy Kulikov / Openwall (for Linux 2.6), 12 * Pavel Kankovsky (for Linux 2.4.32) 13 * 14 * Pavel gave all rights to bugs to Vasiliy, 15 * none of the bugs are Pavel's now. 16 */ 17 18 #include <linux/uaccess.h> 19 #include <linux/types.h> 20 #include <linux/fcntl.h> 21 #include <linux/socket.h> 22 #include <linux/sockios.h> 23 #include <linux/in.h> 24 #include <linux/errno.h> 25 #include <linux/timer.h> 26 #include <linux/mm.h> 27 #include <linux/inet.h> 28 #include <linux/netdevice.h> 29 #include <net/snmp.h> 30 #include <net/ip.h> 31 #include <net/icmp.h> 32 #include <net/protocol.h> 33 #include <linux/skbuff.h> 34 #include <linux/proc_fs.h> 35 #include <linux/export.h> 36 #include <net/sock.h> 37 #include <net/ping.h> 38 #include <net/udp.h> 39 #include <net/route.h> 40 #include <net/inet_common.h> 41 #include <net/checksum.h> 42 43 #if IS_ENABLED(CONFIG_IPV6) 44 #include <linux/in6.h> 45 #include <linux/icmpv6.h> 46 #include <net/addrconf.h> 47 #include <net/ipv6.h> 48 #include <net/transp_v6.h> 49 #endif 50 51 struct ping_table { 52 struct hlist_nulls_head hash[PING_HTABLE_SIZE]; 53 rwlock_t lock; 54 }; 55 56 static struct ping_table ping_table; 57 struct pingv6_ops pingv6_ops; 58 EXPORT_SYMBOL_GPL(pingv6_ops); 59 60 static u16 ping_port_rover; 61 62 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask) 63 { 64 u32 res = (num + net_hash_mix(net)) & mask; 65 66 pr_debug("hash(%u) = %u\n", num, res); 67 return res; 68 } 69 EXPORT_SYMBOL_GPL(ping_hash); 70 71 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table, 72 struct net *net, unsigned int num) 73 { 74 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)]; 75 } 76 77 int ping_get_port(struct sock *sk, unsigned short ident) 78 { 79 struct hlist_nulls_node *node; 80 struct hlist_nulls_head *hlist; 81 struct inet_sock *isk, *isk2; 82 struct sock *sk2 = NULL; 83 84 isk = inet_sk(sk); 85 write_lock_bh(&ping_table.lock); 86 if (ident == 0) { 87 u32 i; 88 u16 result = ping_port_rover + 1; 89 90 for (i = 0; i < (1L << 16); i++, result++) { 91 if (!result) 92 result++; /* avoid zero */ 93 hlist = ping_hashslot(&ping_table, sock_net(sk), 94 result); 95 ping_portaddr_for_each_entry(sk2, node, hlist) { 96 isk2 = inet_sk(sk2); 97 98 if (isk2->inet_num == result) 99 goto next_port; 100 } 101 102 /* found */ 103 ping_port_rover = ident = result; 104 break; 105 next_port: 106 ; 107 } 108 if (i >= (1L << 16)) 109 goto fail; 110 } else { 111 hlist = ping_hashslot(&ping_table, sock_net(sk), ident); 112 ping_portaddr_for_each_entry(sk2, node, hlist) { 113 isk2 = inet_sk(sk2); 114 115 /* BUG? Why is this reuse and not reuseaddr? ping.c 116 * doesn't turn off SO_REUSEADDR, and it doesn't expect 117 * that other ping processes can steal its packets. 118 */ 119 if ((isk2->inet_num == ident) && 120 (sk2 != sk) && 121 (!sk2->sk_reuse || !sk->sk_reuse)) 122 goto fail; 123 } 124 } 125 126 pr_debug("found port/ident = %d\n", ident); 127 isk->inet_num = ident; 128 if (sk_unhashed(sk)) { 129 pr_debug("was not hashed\n"); 130 sock_hold(sk); 131 hlist_nulls_add_head(&sk->sk_nulls_node, hlist); 132 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1); 133 } 134 write_unlock_bh(&ping_table.lock); 135 return 0; 136 137 fail: 138 write_unlock_bh(&ping_table.lock); 139 return 1; 140 } 141 EXPORT_SYMBOL_GPL(ping_get_port); 142 143 int ping_hash(struct sock *sk) 144 { 145 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num); 146 BUG(); /* "Please do not press this button again." */ 147 148 return 0; 149 } 150 151 void ping_unhash(struct sock *sk) 152 { 153 struct inet_sock *isk = inet_sk(sk); 154 155 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); 156 write_lock_bh(&ping_table.lock); 157 if (sk_hashed(sk)) { 158 hlist_nulls_del(&sk->sk_nulls_node); 159 sk_nulls_node_init(&sk->sk_nulls_node); 160 sock_put(sk); 161 isk->inet_num = 0; 162 isk->inet_sport = 0; 163 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); 164 } 165 write_unlock_bh(&ping_table.lock); 166 } 167 EXPORT_SYMBOL_GPL(ping_unhash); 168 169 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident) 170 { 171 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident); 172 struct sock *sk = NULL; 173 struct inet_sock *isk; 174 struct hlist_nulls_node *hnode; 175 int dif = skb->dev->ifindex; 176 177 if (skb->protocol == htons(ETH_P_IP)) { 178 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n", 179 (int)ident, &ip_hdr(skb)->daddr, dif); 180 #if IS_ENABLED(CONFIG_IPV6) 181 } else if (skb->protocol == htons(ETH_P_IPV6)) { 182 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n", 183 (int)ident, &ipv6_hdr(skb)->daddr, dif); 184 #endif 185 } 186 187 read_lock_bh(&ping_table.lock); 188 189 ping_portaddr_for_each_entry(sk, hnode, hslot) { 190 isk = inet_sk(sk); 191 192 pr_debug("iterate\n"); 193 if (isk->inet_num != ident) 194 continue; 195 196 if (skb->protocol == htons(ETH_P_IP) && 197 sk->sk_family == AF_INET) { 198 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk, 199 (int) isk->inet_num, &isk->inet_rcv_saddr, 200 sk->sk_bound_dev_if); 201 202 if (isk->inet_rcv_saddr && 203 isk->inet_rcv_saddr != ip_hdr(skb)->daddr) 204 continue; 205 #if IS_ENABLED(CONFIG_IPV6) 206 } else if (skb->protocol == htons(ETH_P_IPV6) && 207 sk->sk_family == AF_INET6) { 208 209 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk, 210 (int) isk->inet_num, 211 &sk->sk_v6_rcv_saddr, 212 sk->sk_bound_dev_if); 213 214 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 215 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, 216 &ipv6_hdr(skb)->daddr)) 217 continue; 218 #endif 219 } else { 220 continue; 221 } 222 223 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif && 224 sk->sk_bound_dev_if != inet_sdif(skb)) 225 continue; 226 227 sock_hold(sk); 228 goto exit; 229 } 230 231 sk = NULL; 232 exit: 233 read_unlock_bh(&ping_table.lock); 234 235 return sk; 236 } 237 238 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 239 kgid_t *high) 240 { 241 kgid_t *data = net->ipv4.ping_group_range.range; 242 unsigned int seq; 243 244 do { 245 seq = read_seqbegin(&net->ipv4.ping_group_range.lock); 246 247 *low = data[0]; 248 *high = data[1]; 249 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); 250 } 251 252 253 int ping_init_sock(struct sock *sk) 254 { 255 struct net *net = sock_net(sk); 256 kgid_t group = current_egid(); 257 struct group_info *group_info; 258 int i; 259 kgid_t low, high; 260 int ret = 0; 261 262 if (sk->sk_family == AF_INET6) 263 sk->sk_ipv6only = 1; 264 265 inet_get_ping_group_range_net(net, &low, &high); 266 if (gid_lte(low, group) && gid_lte(group, high)) 267 return 0; 268 269 group_info = get_current_groups(); 270 for (i = 0; i < group_info->ngroups; i++) { 271 kgid_t gid = group_info->gid[i]; 272 273 if (gid_lte(low, gid) && gid_lte(gid, high)) 274 goto out_release_group; 275 } 276 277 ret = -EACCES; 278 279 out_release_group: 280 put_group_info(group_info); 281 return ret; 282 } 283 EXPORT_SYMBOL_GPL(ping_init_sock); 284 285 void ping_close(struct sock *sk, long timeout) 286 { 287 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 288 inet_sk(sk), inet_sk(sk)->inet_num); 289 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt)); 290 291 sk_common_release(sk); 292 } 293 EXPORT_SYMBOL_GPL(ping_close); 294 295 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 296 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 297 struct sockaddr *uaddr, int addr_len) 298 { 299 struct net *net = sock_net(sk); 300 if (sk->sk_family == AF_INET) { 301 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 302 int chk_addr_ret; 303 304 if (addr_len < sizeof(*addr)) 305 return -EINVAL; 306 307 if (addr->sin_family != AF_INET && 308 !(addr->sin_family == AF_UNSPEC && 309 addr->sin_addr.s_addr == htonl(INADDR_ANY))) 310 return -EAFNOSUPPORT; 311 312 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 313 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 314 315 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); 316 317 if (!inet_addr_valid_or_nonlocal(net, inet_sk(sk), 318 addr->sin_addr.s_addr, 319 chk_addr_ret)) 320 return -EADDRNOTAVAIL; 321 322 #if IS_ENABLED(CONFIG_IPV6) 323 } else if (sk->sk_family == AF_INET6) { 324 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 325 int addr_type, scoped, has_addr; 326 struct net_device *dev = NULL; 327 328 if (addr_len < sizeof(*addr)) 329 return -EINVAL; 330 331 if (addr->sin6_family != AF_INET6) 332 return -EAFNOSUPPORT; 333 334 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 335 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 336 337 addr_type = ipv6_addr_type(&addr->sin6_addr); 338 scoped = __ipv6_addr_needs_scope_id(addr_type); 339 if ((addr_type != IPV6_ADDR_ANY && 340 !(addr_type & IPV6_ADDR_UNICAST)) || 341 (scoped && !addr->sin6_scope_id)) 342 return -EINVAL; 343 344 rcu_read_lock(); 345 if (addr->sin6_scope_id) { 346 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 347 if (!dev) { 348 rcu_read_unlock(); 349 return -ENODEV; 350 } 351 } 352 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 353 scoped); 354 rcu_read_unlock(); 355 356 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr || 357 addr_type == IPV6_ADDR_ANY)) 358 return -EADDRNOTAVAIL; 359 360 if (scoped) 361 sk->sk_bound_dev_if = addr->sin6_scope_id; 362 #endif 363 } else { 364 return -EAFNOSUPPORT; 365 } 366 return 0; 367 } 368 369 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 370 { 371 if (saddr->sa_family == AF_INET) { 372 struct inet_sock *isk = inet_sk(sk); 373 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 374 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 375 #if IS_ENABLED(CONFIG_IPV6) 376 } else if (saddr->sa_family == AF_INET6) { 377 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 378 struct ipv6_pinfo *np = inet6_sk(sk); 379 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 380 #endif 381 } 382 } 383 384 /* 385 * We need our own bind because there are no privileged id's == local ports. 386 * Moreover, we don't allow binding to multi- and broadcast addresses. 387 */ 388 389 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 390 { 391 struct inet_sock *isk = inet_sk(sk); 392 unsigned short snum; 393 int err; 394 int dif = sk->sk_bound_dev_if; 395 396 err = ping_check_bind_addr(sk, isk, uaddr, addr_len); 397 if (err) 398 return err; 399 400 lock_sock(sk); 401 402 err = -EINVAL; 403 if (isk->inet_num != 0) 404 goto out; 405 406 err = -EADDRINUSE; 407 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 408 if (ping_get_port(sk, snum) != 0) { 409 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */ 410 sk->sk_bound_dev_if = dif; 411 goto out; 412 } 413 ping_set_saddr(sk, uaddr); 414 415 pr_debug("after bind(): num = %hu, dif = %d\n", 416 isk->inet_num, 417 sk->sk_bound_dev_if); 418 419 err = 0; 420 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 421 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 422 #if IS_ENABLED(CONFIG_IPV6) 423 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 424 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 425 #endif 426 427 if (snum) 428 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 429 isk->inet_sport = htons(isk->inet_num); 430 isk->inet_daddr = 0; 431 isk->inet_dport = 0; 432 433 #if IS_ENABLED(CONFIG_IPV6) 434 if (sk->sk_family == AF_INET6) 435 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 436 #endif 437 438 sk_dst_reset(sk); 439 out: 440 release_sock(sk); 441 pr_debug("ping_v4_bind -> %d\n", err); 442 return err; 443 } 444 EXPORT_SYMBOL_GPL(ping_bind); 445 446 /* 447 * Is this a supported type of ICMP message? 448 */ 449 450 static inline int ping_supported(int family, int type, int code) 451 { 452 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 453 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) || 454 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) || 455 (family == AF_INET6 && type == ICMPV6_EXT_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) { 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_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 fraglen -= sizeof(struct icmphdr); 591 if (fraglen < 0) 592 BUG(); 593 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), 594 fraglen, &pfh->wcheck, 595 &pfh->msg->msg_iter)) 596 return -EFAULT; 597 } else if (offset < sizeof(struct icmphdr)) { 598 BUG(); 599 } else { 600 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, 601 &pfh->msg->msg_iter)) 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 if (!skb) 627 return 0; 628 pfh->wcheck = csum_partial((char *)&pfh->icmph, 629 sizeof(struct icmphdr), pfh->wcheck); 630 pfh->icmph.checksum = csum_fold(pfh->wcheck); 631 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 632 skb->ip_summed = CHECKSUM_NONE; 633 return ip_push_pending_frames(sk, fl4); 634 } 635 636 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 637 void *user_icmph, size_t icmph_len) 638 { 639 u8 type, code; 640 641 if (len > 0xFFFF) 642 return -EMSGSIZE; 643 644 /* Must have at least a full ICMP header. */ 645 if (len < icmph_len) 646 return -EINVAL; 647 648 /* 649 * Check the flags. 650 */ 651 652 /* Mirror BSD error message compatibility */ 653 if (msg->msg_flags & MSG_OOB) 654 return -EOPNOTSUPP; 655 656 /* 657 * Fetch the ICMP header provided by the userland. 658 * iovec is modified! The ICMP header is consumed. 659 */ 660 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 661 return -EFAULT; 662 663 if (family == AF_INET) { 664 type = ((struct icmphdr *) user_icmph)->type; 665 code = ((struct icmphdr *) user_icmph)->code; 666 #if IS_ENABLED(CONFIG_IPV6) 667 } else if (family == AF_INET6) { 668 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 669 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 670 #endif 671 } else { 672 BUG(); 673 } 674 675 if (!ping_supported(family, type, code)) 676 return -EINVAL; 677 678 return 0; 679 } 680 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 681 682 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 683 { 684 struct net *net = sock_net(sk); 685 struct flowi4 fl4; 686 struct inet_sock *inet = inet_sk(sk); 687 struct ipcm_cookie ipc; 688 struct icmphdr user_icmph; 689 struct pingfakehdr pfh; 690 struct rtable *rt = NULL; 691 struct ip_options_data opt_copy; 692 int free = 0; 693 __be32 saddr, daddr, faddr; 694 u8 tos; 695 int err; 696 697 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 698 699 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 700 sizeof(user_icmph)); 701 if (err) 702 return err; 703 704 /* 705 * Get and verify the address. 706 */ 707 708 if (msg->msg_name) { 709 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 710 if (msg->msg_namelen < sizeof(*usin)) 711 return -EINVAL; 712 if (usin->sin_family != AF_INET) 713 return -EAFNOSUPPORT; 714 daddr = usin->sin_addr.s_addr; 715 /* no remote port */ 716 } else { 717 if (sk->sk_state != TCP_ESTABLISHED) 718 return -EDESTADDRREQ; 719 daddr = inet->inet_daddr; 720 /* no remote port */ 721 } 722 723 ipcm_init_sk(&ipc, inet); 724 725 if (msg->msg_controllen) { 726 err = ip_cmsg_send(sk, msg, &ipc, false); 727 if (unlikely(err)) { 728 kfree(ipc.opt); 729 return err; 730 } 731 if (ipc.opt) 732 free = 1; 733 } 734 if (!ipc.opt) { 735 struct ip_options_rcu *inet_opt; 736 737 rcu_read_lock(); 738 inet_opt = rcu_dereference(inet->inet_opt); 739 if (inet_opt) { 740 memcpy(&opt_copy, inet_opt, 741 sizeof(*inet_opt) + inet_opt->opt.optlen); 742 ipc.opt = &opt_copy.opt; 743 } 744 rcu_read_unlock(); 745 } 746 747 saddr = ipc.addr; 748 ipc.addr = faddr = daddr; 749 750 if (ipc.opt && ipc.opt->opt.srr) { 751 if (!daddr) { 752 err = -EINVAL; 753 goto out_free; 754 } 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 || netif_index_is_l3_master(sock_net(sk), 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, ipc.sockc.mark, tos, 773 RT_SCOPE_UNIVERSE, sk->sk_protocol, 774 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 775 sk->sk_uid); 776 777 fl4.fl4_icmp_type = user_icmph.type; 778 fl4.fl4_icmp_code = user_icmph.code; 779 780 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4)); 781 rt = ip_route_output_flow(net, &fl4, sk); 782 if (IS_ERR(rt)) { 783 err = PTR_ERR(rt); 784 rt = NULL; 785 if (err == -ENETUNREACH) 786 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 787 goto out; 788 } 789 790 err = -EACCES; 791 if ((rt->rt_flags & RTCF_BROADCAST) && 792 !sock_flag(sk, SOCK_BROADCAST)) 793 goto out; 794 795 if (msg->msg_flags & MSG_CONFIRM) 796 goto do_confirm; 797 back_from_confirm: 798 799 if (!ipc.addr) 800 ipc.addr = fl4.daddr; 801 802 lock_sock(sk); 803 804 pfh.icmph.type = user_icmph.type; /* already checked */ 805 pfh.icmph.code = user_icmph.code; /* ditto */ 806 pfh.icmph.checksum = 0; 807 pfh.icmph.un.echo.id = inet->inet_sport; 808 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 809 pfh.msg = msg; 810 pfh.wcheck = 0; 811 pfh.family = AF_INET; 812 813 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 814 0, &ipc, &rt, msg->msg_flags); 815 if (err) 816 ip_flush_pending_frames(sk); 817 else 818 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 819 release_sock(sk); 820 821 out: 822 ip_rt_put(rt); 823 out_free: 824 if (free) 825 kfree(ipc.opt); 826 if (!err) { 827 icmp_out_count(sock_net(sk), user_icmph.type); 828 return len; 829 } 830 return err; 831 832 do_confirm: 833 if (msg->msg_flags & MSG_PROBE) 834 dst_confirm_neigh(&rt->dst, &fl4.daddr); 835 if (!(msg->msg_flags & MSG_PROBE) || len) 836 goto back_from_confirm; 837 err = 0; 838 goto out; 839 } 840 841 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 842 int flags, int *addr_len) 843 { 844 struct inet_sock *isk = inet_sk(sk); 845 int family = sk->sk_family; 846 struct sk_buff *skb; 847 int copied, err; 848 849 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 850 851 err = -EOPNOTSUPP; 852 if (flags & MSG_OOB) 853 goto out; 854 855 if (flags & MSG_ERRQUEUE) 856 return inet_recv_error(sk, msg, len, addr_len); 857 858 skb = skb_recv_datagram(sk, flags, noblock, &err); 859 if (!skb) 860 goto out; 861 862 copied = skb->len; 863 if (copied > len) { 864 msg->msg_flags |= MSG_TRUNC; 865 copied = len; 866 } 867 868 /* Don't bother checking the checksum */ 869 err = skb_copy_datagram_msg(skb, 0, msg, copied); 870 if (err) 871 goto done; 872 873 sock_recv_timestamp(msg, sk, skb); 874 875 /* Copy the address and add cmsg data. */ 876 if (family == AF_INET) { 877 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name); 878 879 if (sin) { 880 sin->sin_family = AF_INET; 881 sin->sin_port = 0 /* skb->h.uh->source */; 882 sin->sin_addr.s_addr = ip_hdr(skb)->saddr; 883 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 884 *addr_len = sizeof(*sin); 885 } 886 887 if (isk->cmsg_flags) 888 ip_cmsg_recv(msg, skb); 889 890 #if IS_ENABLED(CONFIG_IPV6) 891 } else if (family == AF_INET6) { 892 struct ipv6_pinfo *np = inet6_sk(sk); 893 struct ipv6hdr *ip6 = ipv6_hdr(skb); 894 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, 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 inet6_iif(skb)); 906 *addr_len = sizeof(*sin6); 907 } 908 909 if (inet6_sk(sk)->rxopt.all) 910 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 911 if (skb->protocol == htons(ETH_P_IPV6) && 912 inet6_sk(sk)->rxopt.all) 913 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 914 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 915 ip_cmsg_recv(msg, skb); 916 #endif 917 } else { 918 BUG(); 919 } 920 921 err = copied; 922 923 done: 924 skb_free_datagram(sk, skb); 925 out: 926 pr_debug("ping_recvmsg -> %d\n", err); 927 return err; 928 } 929 EXPORT_SYMBOL_GPL(ping_recvmsg); 930 931 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 932 { 933 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 934 inet_sk(sk), inet_sk(sk)->inet_num, skb); 935 if (sock_queue_rcv_skb(sk, skb) < 0) { 936 kfree_skb(skb); 937 pr_debug("ping_queue_rcv_skb -> failed\n"); 938 return -1; 939 } 940 return 0; 941 } 942 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 943 944 945 /* 946 * All we need to do is get the socket. 947 */ 948 949 bool ping_rcv(struct sk_buff *skb) 950 { 951 struct sock *sk; 952 struct net *net = dev_net(skb->dev); 953 struct icmphdr *icmph = icmp_hdr(skb); 954 bool rc = false; 955 956 /* We assume the packet has already been checked by icmp_rcv */ 957 958 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 959 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 960 961 /* Push ICMP header back */ 962 skb_push(skb, skb->data - (u8 *)icmph); 963 964 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 965 if (sk) { 966 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 967 968 pr_debug("rcv on socket %p\n", sk); 969 if (skb2 && !ping_queue_rcv_skb(sk, skb2)) 970 rc = true; 971 sock_put(sk); 972 } 973 974 if (!rc) 975 pr_debug("no socket, dropping\n"); 976 977 return rc; 978 } 979 EXPORT_SYMBOL_GPL(ping_rcv); 980 981 struct proto ping_prot = { 982 .name = "PING", 983 .owner = THIS_MODULE, 984 .init = ping_init_sock, 985 .close = ping_close, 986 .connect = ip4_datagram_connect, 987 .disconnect = __udp_disconnect, 988 .setsockopt = ip_setsockopt, 989 .getsockopt = ip_getsockopt, 990 .sendmsg = ping_v4_sendmsg, 991 .recvmsg = ping_recvmsg, 992 .bind = ping_bind, 993 .backlog_rcv = ping_queue_rcv_skb, 994 .release_cb = ip4_datagram_release_cb, 995 .hash = ping_hash, 996 .unhash = ping_unhash, 997 .get_port = ping_get_port, 998 .put_port = ping_unhash, 999 .obj_size = sizeof(struct inet_sock), 1000 }; 1001 EXPORT_SYMBOL(ping_prot); 1002 1003 #ifdef CONFIG_PROC_FS 1004 1005 static struct sock *ping_get_first(struct seq_file *seq, int start) 1006 { 1007 struct sock *sk; 1008 struct ping_iter_state *state = seq->private; 1009 struct net *net = seq_file_net(seq); 1010 1011 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1012 ++state->bucket) { 1013 struct hlist_nulls_node *node; 1014 struct hlist_nulls_head *hslot; 1015 1016 hslot = &ping_table.hash[state->bucket]; 1017 1018 if (hlist_nulls_empty(hslot)) 1019 continue; 1020 1021 sk_nulls_for_each(sk, node, hslot) { 1022 if (net_eq(sock_net(sk), net) && 1023 sk->sk_family == state->family) 1024 goto found; 1025 } 1026 } 1027 sk = NULL; 1028 found: 1029 return sk; 1030 } 1031 1032 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1033 { 1034 struct ping_iter_state *state = seq->private; 1035 struct net *net = seq_file_net(seq); 1036 1037 do { 1038 sk = sk_nulls_next(sk); 1039 } while (sk && (!net_eq(sock_net(sk), net))); 1040 1041 if (!sk) 1042 return ping_get_first(seq, state->bucket + 1); 1043 return sk; 1044 } 1045 1046 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1047 { 1048 struct sock *sk = ping_get_first(seq, 0); 1049 1050 if (sk) 1051 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1052 --pos; 1053 return pos ? NULL : sk; 1054 } 1055 1056 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1057 __acquires(ping_table.lock) 1058 { 1059 struct ping_iter_state *state = seq->private; 1060 state->bucket = 0; 1061 state->family = family; 1062 1063 read_lock_bh(&ping_table.lock); 1064 1065 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1066 } 1067 EXPORT_SYMBOL_GPL(ping_seq_start); 1068 1069 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1070 { 1071 return ping_seq_start(seq, pos, AF_INET); 1072 } 1073 1074 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1075 { 1076 struct sock *sk; 1077 1078 if (v == SEQ_START_TOKEN) 1079 sk = ping_get_idx(seq, 0); 1080 else 1081 sk = ping_get_next(seq, v); 1082 1083 ++*pos; 1084 return sk; 1085 } 1086 EXPORT_SYMBOL_GPL(ping_seq_next); 1087 1088 void ping_seq_stop(struct seq_file *seq, void *v) 1089 __releases(ping_table.lock) 1090 { 1091 read_unlock_bh(&ping_table.lock); 1092 } 1093 EXPORT_SYMBOL_GPL(ping_seq_stop); 1094 1095 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1096 int bucket) 1097 { 1098 struct inet_sock *inet = inet_sk(sp); 1099 __be32 dest = inet->inet_daddr; 1100 __be32 src = inet->inet_rcv_saddr; 1101 __u16 destp = ntohs(inet->inet_dport); 1102 __u16 srcp = ntohs(inet->inet_sport); 1103 1104 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1105 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", 1106 bucket, src, srcp, dest, destp, sp->sk_state, 1107 sk_wmem_alloc_get(sp), 1108 sk_rmem_alloc_get(sp), 1109 0, 0L, 0, 1110 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1111 0, sock_i_ino(sp), 1112 refcount_read(&sp->sk_refcnt), sp, 1113 atomic_read(&sp->sk_drops)); 1114 } 1115 1116 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1117 { 1118 seq_setwidth(seq, 127); 1119 if (v == SEQ_START_TOKEN) 1120 seq_puts(seq, " sl local_address rem_address st tx_queue " 1121 "rx_queue tr tm->when retrnsmt uid timeout " 1122 "inode ref pointer drops"); 1123 else { 1124 struct ping_iter_state *state = seq->private; 1125 1126 ping_v4_format_sock(v, seq, state->bucket); 1127 } 1128 seq_pad(seq, '\n'); 1129 return 0; 1130 } 1131 1132 static const struct seq_operations ping_v4_seq_ops = { 1133 .start = ping_v4_seq_start, 1134 .show = ping_v4_seq_show, 1135 .next = ping_seq_next, 1136 .stop = ping_seq_stop, 1137 }; 1138 1139 static int __net_init ping_v4_proc_init_net(struct net *net) 1140 { 1141 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops, 1142 sizeof(struct ping_iter_state))) 1143 return -ENOMEM; 1144 return 0; 1145 } 1146 1147 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1148 { 1149 remove_proc_entry("icmp", net->proc_net); 1150 } 1151 1152 static struct pernet_operations ping_v4_net_ops = { 1153 .init = ping_v4_proc_init_net, 1154 .exit = ping_v4_proc_exit_net, 1155 }; 1156 1157 int __init ping_proc_init(void) 1158 { 1159 return register_pernet_subsys(&ping_v4_net_ops); 1160 } 1161 1162 void ping_proc_exit(void) 1163 { 1164 unregister_pernet_subsys(&ping_v4_net_ops); 1165 } 1166 1167 #endif 1168 1169 void __init ping_init(void) 1170 { 1171 int i; 1172 1173 for (i = 0; i < PING_HTABLE_SIZE; i++) 1174 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1175 rwlock_init(&ping_table.lock); 1176 } 1177