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