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 continue; 225 226 sock_hold(sk); 227 goto exit; 228 } 229 230 sk = NULL; 231 exit: 232 read_unlock_bh(&ping_table.lock); 233 234 return sk; 235 } 236 237 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low, 238 kgid_t *high) 239 { 240 kgid_t *data = net->ipv4.ping_group_range.range; 241 unsigned int seq; 242 243 do { 244 seq = read_seqbegin(&net->ipv4.ping_group_range.lock); 245 246 *low = data[0]; 247 *high = data[1]; 248 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq)); 249 } 250 251 252 int ping_init_sock(struct sock *sk) 253 { 254 struct net *net = sock_net(sk); 255 kgid_t group = current_egid(); 256 struct group_info *group_info; 257 int i; 258 kgid_t low, high; 259 int ret = 0; 260 261 if (sk->sk_family == AF_INET6) 262 sk->sk_ipv6only = 1; 263 264 inet_get_ping_group_range_net(net, &low, &high); 265 if (gid_lte(low, group) && gid_lte(group, high)) 266 return 0; 267 268 group_info = get_current_groups(); 269 for (i = 0; i < group_info->ngroups; i++) { 270 kgid_t gid = group_info->gid[i]; 271 272 if (gid_lte(low, gid) && gid_lte(gid, high)) 273 goto out_release_group; 274 } 275 276 ret = -EACCES; 277 278 out_release_group: 279 put_group_info(group_info); 280 return ret; 281 } 282 EXPORT_SYMBOL_GPL(ping_init_sock); 283 284 void ping_close(struct sock *sk, long timeout) 285 { 286 pr_debug("ping_close(sk=%p,sk->num=%u)\n", 287 inet_sk(sk), inet_sk(sk)->inet_num); 288 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt)); 289 290 sk_common_release(sk); 291 } 292 EXPORT_SYMBOL_GPL(ping_close); 293 294 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */ 295 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 296 struct sockaddr *uaddr, int addr_len) 297 { 298 struct net *net = sock_net(sk); 299 if (sk->sk_family == AF_INET) { 300 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; 301 int chk_addr_ret; 302 303 if (addr_len < sizeof(*addr)) 304 return -EINVAL; 305 306 if (addr->sin_family != AF_INET && 307 !(addr->sin_family == AF_UNSPEC && 308 addr->sin_addr.s_addr == htonl(INADDR_ANY))) 309 return -EAFNOSUPPORT; 310 311 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n", 312 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port)); 313 314 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr); 315 316 if (!inet_addr_valid_or_nonlocal(net, inet_sk(sk), 317 addr->sin_addr.s_addr, 318 chk_addr_ret)) 319 return -EADDRNOTAVAIL; 320 321 #if IS_ENABLED(CONFIG_IPV6) 322 } else if (sk->sk_family == AF_INET6) { 323 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr; 324 int addr_type, scoped, has_addr; 325 struct net_device *dev = NULL; 326 327 if (addr_len < sizeof(*addr)) 328 return -EINVAL; 329 330 if (addr->sin6_family != AF_INET6) 331 return -EAFNOSUPPORT; 332 333 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n", 334 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port)); 335 336 addr_type = ipv6_addr_type(&addr->sin6_addr); 337 scoped = __ipv6_addr_needs_scope_id(addr_type); 338 if ((addr_type != IPV6_ADDR_ANY && 339 !(addr_type & IPV6_ADDR_UNICAST)) || 340 (scoped && !addr->sin6_scope_id)) 341 return -EINVAL; 342 343 rcu_read_lock(); 344 if (addr->sin6_scope_id) { 345 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id); 346 if (!dev) { 347 rcu_read_unlock(); 348 return -ENODEV; 349 } 350 } 351 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev, 352 scoped); 353 rcu_read_unlock(); 354 355 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr || 356 addr_type == IPV6_ADDR_ANY)) 357 return -EADDRNOTAVAIL; 358 359 if (scoped) 360 sk->sk_bound_dev_if = addr->sin6_scope_id; 361 #endif 362 } else { 363 return -EAFNOSUPPORT; 364 } 365 return 0; 366 } 367 368 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr) 369 { 370 if (saddr->sa_family == AF_INET) { 371 struct inet_sock *isk = inet_sk(sk); 372 struct sockaddr_in *addr = (struct sockaddr_in *) saddr; 373 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr; 374 #if IS_ENABLED(CONFIG_IPV6) 375 } else if (saddr->sa_family == AF_INET6) { 376 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr; 377 struct ipv6_pinfo *np = inet6_sk(sk); 378 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr; 379 #endif 380 } 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 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port); 407 if (ping_get_port(sk, snum) != 0) { 408 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */ 409 sk->sk_bound_dev_if = dif; 410 goto out; 411 } 412 ping_set_saddr(sk, uaddr); 413 414 pr_debug("after bind(): num = %hu, dif = %d\n", 415 isk->inet_num, 416 sk->sk_bound_dev_if); 417 418 err = 0; 419 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr) 420 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 421 #if IS_ENABLED(CONFIG_IPV6) 422 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 423 sk->sk_userlocks |= SOCK_BINDADDR_LOCK; 424 #endif 425 426 if (snum) 427 sk->sk_userlocks |= SOCK_BINDPORT_LOCK; 428 isk->inet_sport = htons(isk->inet_num); 429 isk->inet_daddr = 0; 430 isk->inet_dport = 0; 431 432 #if IS_ENABLED(CONFIG_IPV6) 433 if (sk->sk_family == AF_INET6) 434 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr)); 435 #endif 436 437 sk_dst_reset(sk); 438 out: 439 release_sock(sk); 440 pr_debug("ping_v4_bind -> %d\n", err); 441 return err; 442 } 443 EXPORT_SYMBOL_GPL(ping_bind); 444 445 /* 446 * Is this a supported type of ICMP message? 447 */ 448 449 static inline int ping_supported(int family, int type, int code) 450 { 451 return (family == AF_INET && type == ICMP_ECHO && code == 0) || 452 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) || 453 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) || 454 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0); 455 } 456 457 /* 458 * This routine is called by the ICMP module when it gets some 459 * sort of error condition. 460 */ 461 462 void ping_err(struct sk_buff *skb, int offset, u32 info) 463 { 464 int family; 465 struct icmphdr *icmph; 466 struct inet_sock *inet_sock; 467 int type; 468 int code; 469 struct net *net = dev_net(skb->dev); 470 struct sock *sk; 471 int harderr; 472 int err; 473 474 if (skb->protocol == htons(ETH_P_IP)) { 475 family = AF_INET; 476 type = icmp_hdr(skb)->type; 477 code = icmp_hdr(skb)->code; 478 icmph = (struct icmphdr *)(skb->data + offset); 479 } else if (skb->protocol == htons(ETH_P_IPV6)) { 480 family = AF_INET6; 481 type = icmp6_hdr(skb)->icmp6_type; 482 code = icmp6_hdr(skb)->icmp6_code; 483 icmph = (struct icmphdr *) (skb->data + offset); 484 } else { 485 BUG(); 486 } 487 488 /* We assume the packet has already been checked by icmp_unreach */ 489 490 if (!ping_supported(family, icmph->type, icmph->code)) 491 return; 492 493 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n", 494 skb->protocol, type, code, ntohs(icmph->un.echo.id), 495 ntohs(icmph->un.echo.sequence)); 496 497 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 498 if (!sk) { 499 pr_debug("no socket, dropping\n"); 500 return; /* No socket for error */ 501 } 502 pr_debug("err on socket %p\n", sk); 503 504 err = 0; 505 harderr = 0; 506 inet_sock = inet_sk(sk); 507 508 if (skb->protocol == htons(ETH_P_IP)) { 509 switch (type) { 510 default: 511 case ICMP_TIME_EXCEEDED: 512 err = EHOSTUNREACH; 513 break; 514 case ICMP_SOURCE_QUENCH: 515 /* This is not a real error but ping wants to see it. 516 * Report it with some fake errno. 517 */ 518 err = EREMOTEIO; 519 break; 520 case ICMP_PARAMETERPROB: 521 err = EPROTO; 522 harderr = 1; 523 break; 524 case ICMP_DEST_UNREACH: 525 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ 526 ipv4_sk_update_pmtu(skb, sk, info); 527 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) { 528 err = EMSGSIZE; 529 harderr = 1; 530 break; 531 } 532 goto out; 533 } 534 err = EHOSTUNREACH; 535 if (code <= NR_ICMP_UNREACH) { 536 harderr = icmp_err_convert[code].fatal; 537 err = icmp_err_convert[code].errno; 538 } 539 break; 540 case ICMP_REDIRECT: 541 /* See ICMP_SOURCE_QUENCH */ 542 ipv4_sk_redirect(skb, sk); 543 err = EREMOTEIO; 544 break; 545 } 546 #if IS_ENABLED(CONFIG_IPV6) 547 } else if (skb->protocol == htons(ETH_P_IPV6)) { 548 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err); 549 #endif 550 } 551 552 /* 553 * RFC1122: OK. Passes ICMP errors back to application, as per 554 * 4.1.3.3. 555 */ 556 if ((family == AF_INET && !inet_sock->recverr) || 557 (family == AF_INET6 && !inet6_sk(sk)->recverr)) { 558 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 559 goto out; 560 } else { 561 if (family == AF_INET) { 562 ip_icmp_error(sk, skb, err, 0 /* no remote port */, 563 info, (u8 *)icmph); 564 #if IS_ENABLED(CONFIG_IPV6) 565 } else if (family == AF_INET6) { 566 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0, 567 info, (u8 *)icmph); 568 #endif 569 } 570 } 571 sk->sk_err = err; 572 sk_error_report(sk); 573 out: 574 sock_put(sk); 575 } 576 EXPORT_SYMBOL_GPL(ping_err); 577 578 /* 579 * Copy and checksum an ICMP Echo packet from user space into a buffer 580 * starting from the payload. 581 */ 582 583 int ping_getfrag(void *from, char *to, 584 int offset, int fraglen, int odd, struct sk_buff *skb) 585 { 586 struct pingfakehdr *pfh = (struct pingfakehdr *)from; 587 588 if (offset == 0) { 589 fraglen -= sizeof(struct icmphdr); 590 if (fraglen < 0) 591 BUG(); 592 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr), 593 fraglen, &pfh->wcheck, 594 &pfh->msg->msg_iter)) 595 return -EFAULT; 596 } else if (offset < sizeof(struct icmphdr)) { 597 BUG(); 598 } else { 599 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck, 600 &pfh->msg->msg_iter)) 601 return -EFAULT; 602 } 603 604 #if IS_ENABLED(CONFIG_IPV6) 605 /* For IPv6, checksum each skb as we go along, as expected by 606 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in 607 * wcheck, it will be finalized in ping_v4_push_pending_frames. 608 */ 609 if (pfh->family == AF_INET6) { 610 skb->csum = pfh->wcheck; 611 skb->ip_summed = CHECKSUM_NONE; 612 pfh->wcheck = 0; 613 } 614 #endif 615 616 return 0; 617 } 618 EXPORT_SYMBOL_GPL(ping_getfrag); 619 620 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh, 621 struct flowi4 *fl4) 622 { 623 struct sk_buff *skb = skb_peek(&sk->sk_write_queue); 624 625 if (!skb) 626 return 0; 627 pfh->wcheck = csum_partial((char *)&pfh->icmph, 628 sizeof(struct icmphdr), pfh->wcheck); 629 pfh->icmph.checksum = csum_fold(pfh->wcheck); 630 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr)); 631 skb->ip_summed = CHECKSUM_NONE; 632 return ip_push_pending_frames(sk, fl4); 633 } 634 635 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, 636 void *user_icmph, size_t icmph_len) 637 { 638 u8 type, code; 639 640 if (len > 0xFFFF) 641 return -EMSGSIZE; 642 643 /* Must have at least a full ICMP header. */ 644 if (len < icmph_len) 645 return -EINVAL; 646 647 /* 648 * Check the flags. 649 */ 650 651 /* Mirror BSD error message compatibility */ 652 if (msg->msg_flags & MSG_OOB) 653 return -EOPNOTSUPP; 654 655 /* 656 * Fetch the ICMP header provided by the userland. 657 * iovec is modified! The ICMP header is consumed. 658 */ 659 if (memcpy_from_msg(user_icmph, msg, icmph_len)) 660 return -EFAULT; 661 662 if (family == AF_INET) { 663 type = ((struct icmphdr *) user_icmph)->type; 664 code = ((struct icmphdr *) user_icmph)->code; 665 #if IS_ENABLED(CONFIG_IPV6) 666 } else if (family == AF_INET6) { 667 type = ((struct icmp6hdr *) user_icmph)->icmp6_type; 668 code = ((struct icmp6hdr *) user_icmph)->icmp6_code; 669 #endif 670 } else { 671 BUG(); 672 } 673 674 if (!ping_supported(family, type, code)) 675 return -EINVAL; 676 677 return 0; 678 } 679 EXPORT_SYMBOL_GPL(ping_common_sendmsg); 680 681 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 682 { 683 struct net *net = sock_net(sk); 684 struct flowi4 fl4; 685 struct inet_sock *inet = inet_sk(sk); 686 struct ipcm_cookie ipc; 687 struct icmphdr user_icmph; 688 struct pingfakehdr pfh; 689 struct rtable *rt = NULL; 690 struct ip_options_data opt_copy; 691 int free = 0; 692 __be32 saddr, daddr, faddr; 693 u8 tos; 694 int err; 695 696 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num); 697 698 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph, 699 sizeof(user_icmph)); 700 if (err) 701 return err; 702 703 /* 704 * Get and verify the address. 705 */ 706 707 if (msg->msg_name) { 708 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name); 709 if (msg->msg_namelen < sizeof(*usin)) 710 return -EINVAL; 711 if (usin->sin_family != AF_INET) 712 return -EAFNOSUPPORT; 713 daddr = usin->sin_addr.s_addr; 714 /* no remote port */ 715 } else { 716 if (sk->sk_state != TCP_ESTABLISHED) 717 return -EDESTADDRREQ; 718 daddr = inet->inet_daddr; 719 /* no remote port */ 720 } 721 722 ipcm_init_sk(&ipc, inet); 723 724 if (msg->msg_controllen) { 725 err = ip_cmsg_send(sk, msg, &ipc, false); 726 if (unlikely(err)) { 727 kfree(ipc.opt); 728 return err; 729 } 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 err = -EINVAL; 752 goto out_free; 753 } 754 faddr = ipc.opt->opt.faddr; 755 } 756 tos = get_rttos(&ipc, inet); 757 if (sock_flag(sk, SOCK_LOCALROUTE) || 758 (msg->msg_flags & MSG_DONTROUTE) || 759 (ipc.opt && ipc.opt->opt.is_strictroute)) { 760 tos |= RTO_ONLINK; 761 } 762 763 if (ipv4_is_multicast(daddr)) { 764 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif)) 765 ipc.oif = inet->mc_index; 766 if (!saddr) 767 saddr = inet->mc_addr; 768 } else if (!ipc.oif) 769 ipc.oif = inet->uc_index; 770 771 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos, 772 RT_SCOPE_UNIVERSE, sk->sk_protocol, 773 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0, 774 sk->sk_uid); 775 776 fl4.fl4_icmp_type = user_icmph.type; 777 fl4.fl4_icmp_code = user_icmph.code; 778 779 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4)); 780 rt = ip_route_output_flow(net, &fl4, sk); 781 if (IS_ERR(rt)) { 782 err = PTR_ERR(rt); 783 rt = NULL; 784 if (err == -ENETUNREACH) 785 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 786 goto out; 787 } 788 789 err = -EACCES; 790 if ((rt->rt_flags & RTCF_BROADCAST) && 791 !sock_flag(sk, SOCK_BROADCAST)) 792 goto out; 793 794 if (msg->msg_flags & MSG_CONFIRM) 795 goto do_confirm; 796 back_from_confirm: 797 798 if (!ipc.addr) 799 ipc.addr = fl4.daddr; 800 801 lock_sock(sk); 802 803 pfh.icmph.type = user_icmph.type; /* already checked */ 804 pfh.icmph.code = user_icmph.code; /* ditto */ 805 pfh.icmph.checksum = 0; 806 pfh.icmph.un.echo.id = inet->inet_sport; 807 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence; 808 pfh.msg = msg; 809 pfh.wcheck = 0; 810 pfh.family = AF_INET; 811 812 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len, 813 0, &ipc, &rt, msg->msg_flags); 814 if (err) 815 ip_flush_pending_frames(sk); 816 else 817 err = ping_v4_push_pending_frames(sk, &pfh, &fl4); 818 release_sock(sk); 819 820 out: 821 ip_rt_put(rt); 822 out_free: 823 if (free) 824 kfree(ipc.opt); 825 if (!err) { 826 icmp_out_count(sock_net(sk), user_icmph.type); 827 return len; 828 } 829 return err; 830 831 do_confirm: 832 if (msg->msg_flags & MSG_PROBE) 833 dst_confirm_neigh(&rt->dst, &fl4.daddr); 834 if (!(msg->msg_flags & MSG_PROBE) || len) 835 goto back_from_confirm; 836 err = 0; 837 goto out; 838 } 839 840 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, 841 int flags, int *addr_len) 842 { 843 struct inet_sock *isk = inet_sk(sk); 844 int family = sk->sk_family; 845 struct sk_buff *skb; 846 int copied, err; 847 848 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num); 849 850 err = -EOPNOTSUPP; 851 if (flags & MSG_OOB) 852 goto out; 853 854 if (flags & MSG_ERRQUEUE) 855 return inet_recv_error(sk, msg, len, addr_len); 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_msg(skb, 0, msg, 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 DECLARE_SOCKADDR(struct sockaddr_in *, sin, 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 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 894 895 if (sin6) { 896 sin6->sin6_family = AF_INET6; 897 sin6->sin6_port = 0; 898 sin6->sin6_addr = ip6->saddr; 899 sin6->sin6_flowinfo = 0; 900 if (np->sndflow) 901 sin6->sin6_flowinfo = ip6_flowinfo(ip6); 902 sin6->sin6_scope_id = 903 ipv6_iface_scope_id(&sin6->sin6_addr, 904 inet6_iif(skb)); 905 *addr_len = sizeof(*sin6); 906 } 907 908 if (inet6_sk(sk)->rxopt.all) 909 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb); 910 if (skb->protocol == htons(ETH_P_IPV6) && 911 inet6_sk(sk)->rxopt.all) 912 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb); 913 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags) 914 ip_cmsg_recv(msg, skb); 915 #endif 916 } else { 917 BUG(); 918 } 919 920 err = copied; 921 922 done: 923 skb_free_datagram(sk, skb); 924 out: 925 pr_debug("ping_recvmsg -> %d\n", err); 926 return err; 927 } 928 EXPORT_SYMBOL_GPL(ping_recvmsg); 929 930 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 931 { 932 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n", 933 inet_sk(sk), inet_sk(sk)->inet_num, skb); 934 if (sock_queue_rcv_skb(sk, skb) < 0) { 935 kfree_skb(skb); 936 pr_debug("ping_queue_rcv_skb -> failed\n"); 937 return -1; 938 } 939 return 0; 940 } 941 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); 942 943 944 /* 945 * All we need to do is get the socket. 946 */ 947 948 bool ping_rcv(struct sk_buff *skb) 949 { 950 struct sock *sk; 951 struct net *net = dev_net(skb->dev); 952 struct icmphdr *icmph = icmp_hdr(skb); 953 bool rc = false; 954 955 /* We assume the packet has already been checked by icmp_rcv */ 956 957 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n", 958 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence)); 959 960 /* Push ICMP header back */ 961 skb_push(skb, skb->data - (u8 *)icmph); 962 963 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id)); 964 if (sk) { 965 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 966 967 pr_debug("rcv on socket %p\n", sk); 968 if (skb2 && !ping_queue_rcv_skb(sk, skb2)) 969 rc = true; 970 sock_put(sk); 971 } 972 973 if (!rc) 974 pr_debug("no socket, dropping\n"); 975 976 return rc; 977 } 978 EXPORT_SYMBOL_GPL(ping_rcv); 979 980 struct proto ping_prot = { 981 .name = "PING", 982 .owner = THIS_MODULE, 983 .init = ping_init_sock, 984 .close = ping_close, 985 .connect = ip4_datagram_connect, 986 .disconnect = __udp_disconnect, 987 .setsockopt = ip_setsockopt, 988 .getsockopt = ip_getsockopt, 989 .sendmsg = ping_v4_sendmsg, 990 .recvmsg = ping_recvmsg, 991 .bind = ping_bind, 992 .backlog_rcv = ping_queue_rcv_skb, 993 .release_cb = ip4_datagram_release_cb, 994 .hash = ping_hash, 995 .unhash = ping_unhash, 996 .get_port = ping_get_port, 997 .put_port = ping_unhash, 998 .obj_size = sizeof(struct inet_sock), 999 }; 1000 EXPORT_SYMBOL(ping_prot); 1001 1002 #ifdef CONFIG_PROC_FS 1003 1004 static struct sock *ping_get_first(struct seq_file *seq, int start) 1005 { 1006 struct sock *sk; 1007 struct ping_iter_state *state = seq->private; 1008 struct net *net = seq_file_net(seq); 1009 1010 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE; 1011 ++state->bucket) { 1012 struct hlist_nulls_node *node; 1013 struct hlist_nulls_head *hslot; 1014 1015 hslot = &ping_table.hash[state->bucket]; 1016 1017 if (hlist_nulls_empty(hslot)) 1018 continue; 1019 1020 sk_nulls_for_each(sk, node, hslot) { 1021 if (net_eq(sock_net(sk), net) && 1022 sk->sk_family == state->family) 1023 goto found; 1024 } 1025 } 1026 sk = NULL; 1027 found: 1028 return sk; 1029 } 1030 1031 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk) 1032 { 1033 struct ping_iter_state *state = seq->private; 1034 struct net *net = seq_file_net(seq); 1035 1036 do { 1037 sk = sk_nulls_next(sk); 1038 } while (sk && (!net_eq(sock_net(sk), net))); 1039 1040 if (!sk) 1041 return ping_get_first(seq, state->bucket + 1); 1042 return sk; 1043 } 1044 1045 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos) 1046 { 1047 struct sock *sk = ping_get_first(seq, 0); 1048 1049 if (sk) 1050 while (pos && (sk = ping_get_next(seq, sk)) != NULL) 1051 --pos; 1052 return pos ? NULL : sk; 1053 } 1054 1055 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family) 1056 __acquires(ping_table.lock) 1057 { 1058 struct ping_iter_state *state = seq->private; 1059 state->bucket = 0; 1060 state->family = family; 1061 1062 read_lock_bh(&ping_table.lock); 1063 1064 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN; 1065 } 1066 EXPORT_SYMBOL_GPL(ping_seq_start); 1067 1068 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos) 1069 { 1070 return ping_seq_start(seq, pos, AF_INET); 1071 } 1072 1073 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1074 { 1075 struct sock *sk; 1076 1077 if (v == SEQ_START_TOKEN) 1078 sk = ping_get_idx(seq, 0); 1079 else 1080 sk = ping_get_next(seq, v); 1081 1082 ++*pos; 1083 return sk; 1084 } 1085 EXPORT_SYMBOL_GPL(ping_seq_next); 1086 1087 void ping_seq_stop(struct seq_file *seq, void *v) 1088 __releases(ping_table.lock) 1089 { 1090 read_unlock_bh(&ping_table.lock); 1091 } 1092 EXPORT_SYMBOL_GPL(ping_seq_stop); 1093 1094 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f, 1095 int bucket) 1096 { 1097 struct inet_sock *inet = inet_sk(sp); 1098 __be32 dest = inet->inet_daddr; 1099 __be32 src = inet->inet_rcv_saddr; 1100 __u16 destp = ntohs(inet->inet_dport); 1101 __u16 srcp = ntohs(inet->inet_sport); 1102 1103 seq_printf(f, "%5d: %08X:%04X %08X:%04X" 1104 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u", 1105 bucket, src, srcp, dest, destp, sp->sk_state, 1106 sk_wmem_alloc_get(sp), 1107 sk_rmem_alloc_get(sp), 1108 0, 0L, 0, 1109 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)), 1110 0, sock_i_ino(sp), 1111 refcount_read(&sp->sk_refcnt), sp, 1112 atomic_read(&sp->sk_drops)); 1113 } 1114 1115 static int ping_v4_seq_show(struct seq_file *seq, void *v) 1116 { 1117 seq_setwidth(seq, 127); 1118 if (v == SEQ_START_TOKEN) 1119 seq_puts(seq, " sl local_address rem_address st tx_queue " 1120 "rx_queue tr tm->when retrnsmt uid timeout " 1121 "inode ref pointer drops"); 1122 else { 1123 struct ping_iter_state *state = seq->private; 1124 1125 ping_v4_format_sock(v, seq, state->bucket); 1126 } 1127 seq_pad(seq, '\n'); 1128 return 0; 1129 } 1130 1131 static const struct seq_operations ping_v4_seq_ops = { 1132 .start = ping_v4_seq_start, 1133 .show = ping_v4_seq_show, 1134 .next = ping_seq_next, 1135 .stop = ping_seq_stop, 1136 }; 1137 1138 static int __net_init ping_v4_proc_init_net(struct net *net) 1139 { 1140 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops, 1141 sizeof(struct ping_iter_state))) 1142 return -ENOMEM; 1143 return 0; 1144 } 1145 1146 static void __net_exit ping_v4_proc_exit_net(struct net *net) 1147 { 1148 remove_proc_entry("icmp", net->proc_net); 1149 } 1150 1151 static struct pernet_operations ping_v4_net_ops = { 1152 .init = ping_v4_proc_init_net, 1153 .exit = ping_v4_proc_exit_net, 1154 }; 1155 1156 int __init ping_proc_init(void) 1157 { 1158 return register_pernet_subsys(&ping_v4_net_ops); 1159 } 1160 1161 void ping_proc_exit(void) 1162 { 1163 unregister_pernet_subsys(&ping_v4_net_ops); 1164 } 1165 1166 #endif 1167 1168 void __init ping_init(void) 1169 { 1170 int i; 1171 1172 for (i = 0; i < PING_HTABLE_SIZE; i++) 1173 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i); 1174 rwlock_init(&ping_table.lock); 1175 } 1176