1 /* 2 * UDP over IPv6 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * 8 * Based on linux/ipv4/udp.c 9 * 10 * Fixes: 11 * Hideaki YOSHIFUJI : sin6_scope_id support 12 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which 13 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind 14 * a single port at the same time. 15 * Kazunori MIYAZAWA @USAGI: change process style to use ip6_append_data 16 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/udp6 to seq_file. 17 * 18 * This program is free software; you can redistribute it and/or 19 * modify it under the terms of the GNU General Public License 20 * as published by the Free Software Foundation; either version 21 * 2 of the License, or (at your option) any later version. 22 */ 23 24 #include <linux/errno.h> 25 #include <linux/types.h> 26 #include <linux/socket.h> 27 #include <linux/sockios.h> 28 #include <linux/net.h> 29 #include <linux/in6.h> 30 #include <linux/netdevice.h> 31 #include <linux/if_arp.h> 32 #include <linux/ipv6.h> 33 #include <linux/icmpv6.h> 34 #include <linux/init.h> 35 #include <linux/module.h> 36 #include <linux/skbuff.h> 37 #include <linux/slab.h> 38 #include <linux/uaccess.h> 39 40 #include <net/addrconf.h> 41 #include <net/ndisc.h> 42 #include <net/protocol.h> 43 #include <net/transp_v6.h> 44 #include <net/ip6_route.h> 45 #include <net/raw.h> 46 #include <net/tcp_states.h> 47 #include <net/ip6_checksum.h> 48 #include <net/xfrm.h> 49 #include <net/inet_hashtables.h> 50 #include <net/inet6_hashtables.h> 51 #include <net/busy_poll.h> 52 #include <net/sock_reuseport.h> 53 54 #include <linux/proc_fs.h> 55 #include <linux/seq_file.h> 56 #include <trace/events/skb.h> 57 #include "udp_impl.h" 58 59 static bool udp6_lib_exact_dif_match(struct net *net, struct sk_buff *skb) 60 { 61 #if defined(CONFIG_NET_L3_MASTER_DEV) 62 if (!net->ipv4.sysctl_udp_l3mdev_accept && 63 skb && ipv6_l3mdev_skb(IP6CB(skb)->flags)) 64 return true; 65 #endif 66 return false; 67 } 68 69 static u32 udp6_ehashfn(const struct net *net, 70 const struct in6_addr *laddr, 71 const u16 lport, 72 const struct in6_addr *faddr, 73 const __be16 fport) 74 { 75 static u32 udp6_ehash_secret __read_mostly; 76 static u32 udp_ipv6_hash_secret __read_mostly; 77 78 u32 lhash, fhash; 79 80 net_get_random_once(&udp6_ehash_secret, 81 sizeof(udp6_ehash_secret)); 82 net_get_random_once(&udp_ipv6_hash_secret, 83 sizeof(udp_ipv6_hash_secret)); 84 85 lhash = (__force u32)laddr->s6_addr32[3]; 86 fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret); 87 88 return __inet6_ehashfn(lhash, lport, fhash, fport, 89 udp_ipv6_hash_secret + net_hash_mix(net)); 90 } 91 92 static u32 udp6_portaddr_hash(const struct net *net, 93 const struct in6_addr *addr6, 94 unsigned int port) 95 { 96 unsigned int hash, mix = net_hash_mix(net); 97 98 if (ipv6_addr_any(addr6)) 99 hash = jhash_1word(0, mix); 100 else if (ipv6_addr_v4mapped(addr6)) 101 hash = jhash_1word((__force u32)addr6->s6_addr32[3], mix); 102 else 103 hash = jhash2((__force u32 *)addr6->s6_addr32, 4, mix); 104 105 return hash ^ port; 106 } 107 108 int udp_v6_get_port(struct sock *sk, unsigned short snum) 109 { 110 unsigned int hash2_nulladdr = 111 udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum); 112 unsigned int hash2_partial = 113 udp6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0); 114 115 /* precompute partial secondary hash */ 116 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 117 return udp_lib_get_port(sk, snum, hash2_nulladdr); 118 } 119 120 static void udp_v6_rehash(struct sock *sk) 121 { 122 u16 new_hash = udp6_portaddr_hash(sock_net(sk), 123 &sk->sk_v6_rcv_saddr, 124 inet_sk(sk)->inet_num); 125 126 udp_lib_rehash(sk, new_hash); 127 } 128 129 static int compute_score(struct sock *sk, struct net *net, 130 const struct in6_addr *saddr, __be16 sport, 131 const struct in6_addr *daddr, unsigned short hnum, 132 int dif, bool exact_dif) 133 { 134 int score; 135 struct inet_sock *inet; 136 137 if (!net_eq(sock_net(sk), net) || 138 udp_sk(sk)->udp_port_hash != hnum || 139 sk->sk_family != PF_INET6) 140 return -1; 141 142 score = 0; 143 inet = inet_sk(sk); 144 145 if (inet->inet_dport) { 146 if (inet->inet_dport != sport) 147 return -1; 148 score++; 149 } 150 151 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) { 152 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr)) 153 return -1; 154 score++; 155 } 156 157 if (!ipv6_addr_any(&sk->sk_v6_daddr)) { 158 if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr)) 159 return -1; 160 score++; 161 } 162 163 if (sk->sk_bound_dev_if || exact_dif) { 164 if (sk->sk_bound_dev_if != dif) 165 return -1; 166 score++; 167 } 168 169 if (sk->sk_incoming_cpu == raw_smp_processor_id()) 170 score++; 171 172 return score; 173 } 174 175 /* called with rcu_read_lock() */ 176 static struct sock *udp6_lib_lookup2(struct net *net, 177 const struct in6_addr *saddr, __be16 sport, 178 const struct in6_addr *daddr, unsigned int hnum, int dif, 179 bool exact_dif, struct udp_hslot *hslot2, 180 struct sk_buff *skb) 181 { 182 struct sock *sk, *result; 183 int score, badness, matches = 0, reuseport = 0; 184 u32 hash = 0; 185 186 result = NULL; 187 badness = -1; 188 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 189 score = compute_score(sk, net, saddr, sport, 190 daddr, hnum, dif, exact_dif); 191 if (score > badness) { 192 reuseport = sk->sk_reuseport; 193 if (reuseport) { 194 hash = udp6_ehashfn(net, daddr, hnum, 195 saddr, sport); 196 197 result = reuseport_select_sock(sk, hash, skb, 198 sizeof(struct udphdr)); 199 if (result) 200 return result; 201 matches = 1; 202 } 203 result = sk; 204 badness = score; 205 } else if (score == badness && reuseport) { 206 matches++; 207 if (reciprocal_scale(hash, matches) == 0) 208 result = sk; 209 hash = next_pseudo_random32(hash); 210 } 211 } 212 return result; 213 } 214 215 /* rcu_read_lock() must be held */ 216 struct sock *__udp6_lib_lookup(struct net *net, 217 const struct in6_addr *saddr, __be16 sport, 218 const struct in6_addr *daddr, __be16 dport, 219 int dif, struct udp_table *udptable, 220 struct sk_buff *skb) 221 { 222 struct sock *sk, *result; 223 unsigned short hnum = ntohs(dport); 224 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); 225 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; 226 bool exact_dif = udp6_lib_exact_dif_match(net, skb); 227 int score, badness, matches = 0, reuseport = 0; 228 u32 hash = 0; 229 230 if (hslot->count > 10) { 231 hash2 = udp6_portaddr_hash(net, daddr, hnum); 232 slot2 = hash2 & udptable->mask; 233 hslot2 = &udptable->hash2[slot2]; 234 if (hslot->count < hslot2->count) 235 goto begin; 236 237 result = udp6_lib_lookup2(net, saddr, sport, 238 daddr, hnum, dif, exact_dif, 239 hslot2, skb); 240 if (!result) { 241 unsigned int old_slot2 = slot2; 242 hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum); 243 slot2 = hash2 & udptable->mask; 244 /* avoid searching the same slot again. */ 245 if (unlikely(slot2 == old_slot2)) 246 return result; 247 248 hslot2 = &udptable->hash2[slot2]; 249 if (hslot->count < hslot2->count) 250 goto begin; 251 252 result = udp6_lib_lookup2(net, saddr, sport, 253 daddr, hnum, dif, 254 exact_dif, hslot2, 255 skb); 256 } 257 return result; 258 } 259 begin: 260 result = NULL; 261 badness = -1; 262 sk_for_each_rcu(sk, &hslot->head) { 263 score = compute_score(sk, net, saddr, sport, daddr, hnum, dif, 264 exact_dif); 265 if (score > badness) { 266 reuseport = sk->sk_reuseport; 267 if (reuseport) { 268 hash = udp6_ehashfn(net, daddr, hnum, 269 saddr, sport); 270 result = reuseport_select_sock(sk, hash, skb, 271 sizeof(struct udphdr)); 272 if (result) 273 return result; 274 matches = 1; 275 } 276 result = sk; 277 badness = score; 278 } else if (score == badness && reuseport) { 279 matches++; 280 if (reciprocal_scale(hash, matches) == 0) 281 result = sk; 282 hash = next_pseudo_random32(hash); 283 } 284 } 285 return result; 286 } 287 EXPORT_SYMBOL_GPL(__udp6_lib_lookup); 288 289 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb, 290 __be16 sport, __be16 dport, 291 struct udp_table *udptable) 292 { 293 const struct ipv6hdr *iph = ipv6_hdr(skb); 294 295 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, 296 &iph->daddr, dport, inet6_iif(skb), 297 udptable, skb); 298 } 299 300 struct sock *udp6_lib_lookup_skb(struct sk_buff *skb, 301 __be16 sport, __be16 dport) 302 { 303 const struct ipv6hdr *iph = ipv6_hdr(skb); 304 305 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, 306 &iph->daddr, dport, inet6_iif(skb), 307 &udp_table, skb); 308 } 309 EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb); 310 311 /* Must be called under rcu_read_lock(). 312 * Does increment socket refcount. 313 */ 314 #if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \ 315 IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) || \ 316 IS_ENABLED(CONFIG_NF_SOCKET_IPV6) 317 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, 318 const struct in6_addr *daddr, __be16 dport, int dif) 319 { 320 struct sock *sk; 321 322 sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport, 323 dif, &udp_table, NULL); 324 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) 325 sk = NULL; 326 return sk; 327 } 328 EXPORT_SYMBOL_GPL(udp6_lib_lookup); 329 #endif 330 331 /* do not use the scratch area len for jumbogram: their length execeeds the 332 * scratch area space; note that the IP6CB flags is still in the first 333 * cacheline, so checking for jumbograms is cheap 334 */ 335 static int udp6_skb_len(struct sk_buff *skb) 336 { 337 return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb); 338 } 339 340 /* 341 * This should be easy, if there is something there we 342 * return it, otherwise we block. 343 */ 344 345 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 346 int noblock, int flags, int *addr_len) 347 { 348 struct ipv6_pinfo *np = inet6_sk(sk); 349 struct inet_sock *inet = inet_sk(sk); 350 struct sk_buff *skb; 351 unsigned int ulen, copied; 352 int peeked, peeking, off; 353 int err; 354 int is_udplite = IS_UDPLITE(sk); 355 bool checksum_valid = false; 356 int is_udp4; 357 358 if (flags & MSG_ERRQUEUE) 359 return ipv6_recv_error(sk, msg, len, addr_len); 360 361 if (np->rxpmtu && np->rxopt.bits.rxpmtu) 362 return ipv6_recv_rxpmtu(sk, msg, len, addr_len); 363 364 try_again: 365 peeking = flags & MSG_PEEK; 366 off = sk_peek_offset(sk, flags); 367 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err); 368 if (!skb) 369 return err; 370 371 ulen = udp6_skb_len(skb); 372 copied = len; 373 if (copied > ulen - off) 374 copied = ulen - off; 375 else if (copied < ulen) 376 msg->msg_flags |= MSG_TRUNC; 377 378 is_udp4 = (skb->protocol == htons(ETH_P_IP)); 379 380 /* 381 * If checksum is needed at all, try to do it while copying the 382 * data. If the data is truncated, or if we only want a partial 383 * coverage checksum (UDP-Lite), do it before the copy. 384 */ 385 386 if (copied < ulen || peeking || 387 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { 388 checksum_valid = udp_skb_csum_unnecessary(skb) || 389 !__udp_lib_checksum_complete(skb); 390 if (!checksum_valid) 391 goto csum_copy_err; 392 } 393 394 if (checksum_valid || udp_skb_csum_unnecessary(skb)) { 395 if (udp_skb_is_linear(skb)) 396 err = copy_linear_skb(skb, copied, off, &msg->msg_iter); 397 else 398 err = skb_copy_datagram_msg(skb, off, msg, copied); 399 } else { 400 err = skb_copy_and_csum_datagram_msg(skb, off, msg); 401 if (err == -EINVAL) 402 goto csum_copy_err; 403 } 404 if (unlikely(err)) { 405 if (!peeked) { 406 atomic_inc(&sk->sk_drops); 407 if (is_udp4) 408 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, 409 is_udplite); 410 else 411 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, 412 is_udplite); 413 } 414 kfree_skb(skb); 415 return err; 416 } 417 if (!peeked) { 418 if (is_udp4) 419 UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS, 420 is_udplite); 421 else 422 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS, 423 is_udplite); 424 } 425 426 sock_recv_ts_and_drops(msg, sk, skb); 427 428 /* Copy the address. */ 429 if (msg->msg_name) { 430 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 431 sin6->sin6_family = AF_INET6; 432 sin6->sin6_port = udp_hdr(skb)->source; 433 sin6->sin6_flowinfo = 0; 434 435 if (is_udp4) { 436 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, 437 &sin6->sin6_addr); 438 sin6->sin6_scope_id = 0; 439 } else { 440 sin6->sin6_addr = ipv6_hdr(skb)->saddr; 441 sin6->sin6_scope_id = 442 ipv6_iface_scope_id(&sin6->sin6_addr, 443 inet6_iif(skb)); 444 } 445 *addr_len = sizeof(*sin6); 446 } 447 448 if (np->rxopt.all) 449 ip6_datagram_recv_common_ctl(sk, msg, skb); 450 451 if (is_udp4) { 452 if (inet->cmsg_flags) 453 ip_cmsg_recv_offset(msg, sk, skb, 454 sizeof(struct udphdr), off); 455 } else { 456 if (np->rxopt.all) 457 ip6_datagram_recv_specific_ctl(sk, msg, skb); 458 } 459 460 err = copied; 461 if (flags & MSG_TRUNC) 462 err = ulen; 463 464 skb_consume_udp(sk, skb, peeking ? -err : err); 465 return err; 466 467 csum_copy_err: 468 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, 469 udp_skb_destructor)) { 470 if (is_udp4) { 471 UDP_INC_STATS(sock_net(sk), 472 UDP_MIB_CSUMERRORS, is_udplite); 473 UDP_INC_STATS(sock_net(sk), 474 UDP_MIB_INERRORS, is_udplite); 475 } else { 476 UDP6_INC_STATS(sock_net(sk), 477 UDP_MIB_CSUMERRORS, is_udplite); 478 UDP6_INC_STATS(sock_net(sk), 479 UDP_MIB_INERRORS, is_udplite); 480 } 481 } 482 kfree_skb(skb); 483 484 /* starting over for a new packet, but check if we need to yield */ 485 cond_resched(); 486 msg->msg_flags &= ~MSG_TRUNC; 487 goto try_again; 488 } 489 490 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 491 u8 type, u8 code, int offset, __be32 info, 492 struct udp_table *udptable) 493 { 494 struct ipv6_pinfo *np; 495 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; 496 const struct in6_addr *saddr = &hdr->saddr; 497 const struct in6_addr *daddr = &hdr->daddr; 498 struct udphdr *uh = (struct udphdr *)(skb->data+offset); 499 struct sock *sk; 500 int harderr; 501 int err; 502 struct net *net = dev_net(skb->dev); 503 504 sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source, 505 inet6_iif(skb), udptable, skb); 506 if (!sk) { 507 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), 508 ICMP6_MIB_INERRORS); 509 return; 510 } 511 512 harderr = icmpv6_err_convert(type, code, &err); 513 np = inet6_sk(sk); 514 515 if (type == ICMPV6_PKT_TOOBIG) { 516 if (!ip6_sk_accept_pmtu(sk)) 517 goto out; 518 ip6_sk_update_pmtu(skb, sk, info); 519 if (np->pmtudisc != IPV6_PMTUDISC_DONT) 520 harderr = 1; 521 } 522 if (type == NDISC_REDIRECT) { 523 ip6_sk_redirect(skb, sk); 524 goto out; 525 } 526 527 if (!np->recverr) { 528 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 529 goto out; 530 } else { 531 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1)); 532 } 533 534 sk->sk_err = err; 535 sk->sk_error_report(sk); 536 out: 537 return; 538 } 539 540 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 541 { 542 int rc; 543 544 if (!ipv6_addr_any(&sk->sk_v6_daddr)) { 545 sock_rps_save_rxhash(sk, skb); 546 sk_mark_napi_id(sk, skb); 547 sk_incoming_cpu_update(sk); 548 } else { 549 sk_mark_napi_id_once(sk, skb); 550 } 551 552 rc = __udp_enqueue_schedule_skb(sk, skb); 553 if (rc < 0) { 554 int is_udplite = IS_UDPLITE(sk); 555 556 /* Note that an ENOMEM error is charged twice */ 557 if (rc == -ENOMEM) 558 UDP6_INC_STATS(sock_net(sk), 559 UDP_MIB_RCVBUFERRORS, is_udplite); 560 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 561 kfree_skb(skb); 562 return -1; 563 } 564 565 return 0; 566 } 567 568 static __inline__ void udpv6_err(struct sk_buff *skb, 569 struct inet6_skb_parm *opt, u8 type, 570 u8 code, int offset, __be32 info) 571 { 572 __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table); 573 } 574 575 static struct static_key udpv6_encap_needed __read_mostly; 576 void udpv6_encap_enable(void) 577 { 578 if (!static_key_enabled(&udpv6_encap_needed)) 579 static_key_slow_inc(&udpv6_encap_needed); 580 } 581 EXPORT_SYMBOL(udpv6_encap_enable); 582 583 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 584 { 585 struct udp_sock *up = udp_sk(sk); 586 int is_udplite = IS_UDPLITE(sk); 587 588 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 589 goto drop; 590 591 if (static_key_false(&udpv6_encap_needed) && up->encap_type) { 592 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 593 594 /* 595 * This is an encapsulation socket so pass the skb to 596 * the socket's udp_encap_rcv() hook. Otherwise, just 597 * fall through and pass this up the UDP socket. 598 * up->encap_rcv() returns the following value: 599 * =0 if skb was successfully passed to the encap 600 * handler or was discarded by it. 601 * >0 if skb should be passed on to UDP. 602 * <0 if skb should be resubmitted as proto -N 603 */ 604 605 /* if we're overly short, let UDP handle it */ 606 encap_rcv = ACCESS_ONCE(up->encap_rcv); 607 if (encap_rcv) { 608 int ret; 609 610 /* Verify checksum before giving to encap */ 611 if (udp_lib_checksum_complete(skb)) 612 goto csum_error; 613 614 ret = encap_rcv(sk, skb); 615 if (ret <= 0) { 616 __UDP_INC_STATS(sock_net(sk), 617 UDP_MIB_INDATAGRAMS, 618 is_udplite); 619 return -ret; 620 } 621 } 622 623 /* FALLTHROUGH -- it's a UDP Packet */ 624 } 625 626 /* 627 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c). 628 */ 629 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 630 631 if (up->pcrlen == 0) { /* full coverage was set */ 632 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n", 633 UDP_SKB_CB(skb)->cscov, skb->len); 634 goto drop; 635 } 636 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 637 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n", 638 UDP_SKB_CB(skb)->cscov, up->pcrlen); 639 goto drop; 640 } 641 } 642 643 prefetch(&sk->sk_rmem_alloc); 644 if (rcu_access_pointer(sk->sk_filter) && 645 udp_lib_checksum_complete(skb)) 646 goto csum_error; 647 648 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) 649 goto drop; 650 651 udp_csum_pull_header(skb); 652 653 skb_dst_drop(skb); 654 655 return __udpv6_queue_rcv_skb(sk, skb); 656 657 csum_error: 658 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 659 drop: 660 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 661 atomic_inc(&sk->sk_drops); 662 kfree_skb(skb); 663 return -1; 664 } 665 666 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk, 667 __be16 loc_port, const struct in6_addr *loc_addr, 668 __be16 rmt_port, const struct in6_addr *rmt_addr, 669 int dif, unsigned short hnum) 670 { 671 struct inet_sock *inet = inet_sk(sk); 672 673 if (!net_eq(sock_net(sk), net)) 674 return false; 675 676 if (udp_sk(sk)->udp_port_hash != hnum || 677 sk->sk_family != PF_INET6 || 678 (inet->inet_dport && inet->inet_dport != rmt_port) || 679 (!ipv6_addr_any(&sk->sk_v6_daddr) && 680 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) || 681 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) || 682 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 683 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr))) 684 return false; 685 if (!inet6_mc_check(sk, loc_addr, rmt_addr)) 686 return false; 687 return true; 688 } 689 690 static void udp6_csum_zero_error(struct sk_buff *skb) 691 { 692 /* RFC 2460 section 8.1 says that we SHOULD log 693 * this error. Well, it is reasonable. 694 */ 695 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n", 696 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source), 697 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest)); 698 } 699 700 /* 701 * Note: called only from the BH handler context, 702 * so we don't need to lock the hashes. 703 */ 704 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 705 const struct in6_addr *saddr, const struct in6_addr *daddr, 706 struct udp_table *udptable, int proto) 707 { 708 struct sock *sk, *first = NULL; 709 const struct udphdr *uh = udp_hdr(skb); 710 unsigned short hnum = ntohs(uh->dest); 711 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); 712 unsigned int offset = offsetof(typeof(*sk), sk_node); 713 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); 714 int dif = inet6_iif(skb); 715 struct hlist_node *node; 716 struct sk_buff *nskb; 717 718 if (use_hash2) { 719 hash2_any = udp6_portaddr_hash(net, &in6addr_any, hnum) & 720 udptable->mask; 721 hash2 = udp6_portaddr_hash(net, daddr, hnum) & udptable->mask; 722 start_lookup: 723 hslot = &udptable->hash2[hash2]; 724 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); 725 } 726 727 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { 728 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr, 729 uh->source, saddr, dif, hnum)) 730 continue; 731 /* If zero checksum and no_check is not on for 732 * the socket then skip it. 733 */ 734 if (!uh->check && !udp_sk(sk)->no_check6_rx) 735 continue; 736 if (!first) { 737 first = sk; 738 continue; 739 } 740 nskb = skb_clone(skb, GFP_ATOMIC); 741 if (unlikely(!nskb)) { 742 atomic_inc(&sk->sk_drops); 743 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS, 744 IS_UDPLITE(sk)); 745 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, 746 IS_UDPLITE(sk)); 747 continue; 748 } 749 750 if (udpv6_queue_rcv_skb(sk, nskb) > 0) 751 consume_skb(nskb); 752 } 753 754 /* Also lookup *:port if we are using hash2 and haven't done so yet. */ 755 if (use_hash2 && hash2 != hash2_any) { 756 hash2 = hash2_any; 757 goto start_lookup; 758 } 759 760 if (first) { 761 if (udpv6_queue_rcv_skb(first, skb) > 0) 762 consume_skb(skb); 763 } else { 764 kfree_skb(skb); 765 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI, 766 proto == IPPROTO_UDPLITE); 767 } 768 return 0; 769 } 770 771 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 772 int proto) 773 { 774 const struct in6_addr *saddr, *daddr; 775 struct net *net = dev_net(skb->dev); 776 struct udphdr *uh; 777 struct sock *sk; 778 u32 ulen = 0; 779 780 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 781 goto discard; 782 783 saddr = &ipv6_hdr(skb)->saddr; 784 daddr = &ipv6_hdr(skb)->daddr; 785 uh = udp_hdr(skb); 786 787 ulen = ntohs(uh->len); 788 if (ulen > skb->len) 789 goto short_packet; 790 791 if (proto == IPPROTO_UDP) { 792 /* UDP validates ulen. */ 793 794 /* Check for jumbo payload */ 795 if (ulen == 0) 796 ulen = skb->len; 797 798 if (ulen < sizeof(*uh)) 799 goto short_packet; 800 801 if (ulen < skb->len) { 802 if (pskb_trim_rcsum(skb, ulen)) 803 goto short_packet; 804 saddr = &ipv6_hdr(skb)->saddr; 805 daddr = &ipv6_hdr(skb)->daddr; 806 uh = udp_hdr(skb); 807 } 808 } 809 810 if (udp6_csum_init(skb, uh, proto)) 811 goto csum_error; 812 813 /* Check if the socket is already available, e.g. due to early demux */ 814 sk = skb_steal_sock(skb); 815 if (sk) { 816 struct dst_entry *dst = skb_dst(skb); 817 int ret; 818 819 if (unlikely(sk->sk_rx_dst != dst)) 820 udp_sk_rx_dst_set(sk, dst); 821 822 ret = udpv6_queue_rcv_skb(sk, skb); 823 sock_put(sk); 824 825 /* a return value > 0 means to resubmit the input */ 826 if (ret > 0) 827 return ret; 828 return 0; 829 } 830 831 /* 832 * Multicast receive code 833 */ 834 if (ipv6_addr_is_multicast(daddr)) 835 return __udp6_lib_mcast_deliver(net, skb, 836 saddr, daddr, udptable, proto); 837 838 /* Unicast */ 839 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 840 if (sk) { 841 int ret; 842 843 if (!uh->check && !udp_sk(sk)->no_check6_rx) { 844 udp6_csum_zero_error(skb); 845 goto csum_error; 846 } 847 848 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) 849 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check, 850 ip6_compute_pseudo); 851 852 ret = udpv6_queue_rcv_skb(sk, skb); 853 854 /* a return value > 0 means to resubmit the input */ 855 if (ret > 0) 856 return ret; 857 858 return 0; 859 } 860 861 if (!uh->check) { 862 udp6_csum_zero_error(skb); 863 goto csum_error; 864 } 865 866 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 867 goto discard; 868 869 if (udp_lib_checksum_complete(skb)) 870 goto csum_error; 871 872 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 873 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 874 875 kfree_skb(skb); 876 return 0; 877 878 short_packet: 879 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n", 880 proto == IPPROTO_UDPLITE ? "-Lite" : "", 881 saddr, ntohs(uh->source), 882 ulen, skb->len, 883 daddr, ntohs(uh->dest)); 884 goto discard; 885 csum_error: 886 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 887 discard: 888 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 889 kfree_skb(skb); 890 return 0; 891 } 892 893 894 static struct sock *__udp6_lib_demux_lookup(struct net *net, 895 __be16 loc_port, const struct in6_addr *loc_addr, 896 __be16 rmt_port, const struct in6_addr *rmt_addr, 897 int dif) 898 { 899 unsigned short hnum = ntohs(loc_port); 900 unsigned int hash2 = udp6_portaddr_hash(net, loc_addr, hnum); 901 unsigned int slot2 = hash2 & udp_table.mask; 902 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 903 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 904 struct sock *sk; 905 906 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 907 if (sk->sk_state == TCP_ESTABLISHED && 908 INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif)) 909 return sk; 910 /* Only check first socket in chain */ 911 break; 912 } 913 return NULL; 914 } 915 916 static void udp_v6_early_demux(struct sk_buff *skb) 917 { 918 struct net *net = dev_net(skb->dev); 919 const struct udphdr *uh; 920 struct sock *sk; 921 struct dst_entry *dst; 922 int dif = skb->dev->ifindex; 923 924 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 925 sizeof(struct udphdr))) 926 return; 927 928 uh = udp_hdr(skb); 929 930 if (skb->pkt_type == PACKET_HOST) 931 sk = __udp6_lib_demux_lookup(net, uh->dest, 932 &ipv6_hdr(skb)->daddr, 933 uh->source, &ipv6_hdr(skb)->saddr, 934 dif); 935 else 936 return; 937 938 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) 939 return; 940 941 skb->sk = sk; 942 skb->destructor = sock_efree; 943 dst = READ_ONCE(sk->sk_rx_dst); 944 945 if (dst) 946 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie); 947 if (dst) { 948 /* set noref for now. 949 * any place which wants to hold dst has to call 950 * dst_hold_safe() 951 */ 952 skb_dst_set_noref(skb, dst); 953 } 954 } 955 956 static __inline__ int udpv6_rcv(struct sk_buff *skb) 957 { 958 return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP); 959 } 960 961 /* 962 * Throw away all pending data and cancel the corking. Socket is locked. 963 */ 964 static void udp_v6_flush_pending_frames(struct sock *sk) 965 { 966 struct udp_sock *up = udp_sk(sk); 967 968 if (up->pending == AF_INET) 969 udp_flush_pending_frames(sk); 970 else if (up->pending) { 971 up->len = 0; 972 up->pending = 0; 973 ip6_flush_pending_frames(sk); 974 } 975 } 976 977 /** 978 * udp6_hwcsum_outgoing - handle outgoing HW checksumming 979 * @sk: socket we are sending on 980 * @skb: sk_buff containing the filled-in UDP header 981 * (checksum field must be zeroed out) 982 */ 983 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, 984 const struct in6_addr *saddr, 985 const struct in6_addr *daddr, int len) 986 { 987 unsigned int offset; 988 struct udphdr *uh = udp_hdr(skb); 989 struct sk_buff *frags = skb_shinfo(skb)->frag_list; 990 __wsum csum = 0; 991 992 if (!frags) { 993 /* Only one fragment on the socket. */ 994 skb->csum_start = skb_transport_header(skb) - skb->head; 995 skb->csum_offset = offsetof(struct udphdr, check); 996 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0); 997 } else { 998 /* 999 * HW-checksum won't work as there are two or more 1000 * fragments on the socket so that all csums of sk_buffs 1001 * should be together 1002 */ 1003 offset = skb_transport_offset(skb); 1004 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); 1005 1006 skb->ip_summed = CHECKSUM_NONE; 1007 1008 do { 1009 csum = csum_add(csum, frags->csum); 1010 } while ((frags = frags->next)); 1011 1012 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 1013 csum); 1014 if (uh->check == 0) 1015 uh->check = CSUM_MANGLED_0; 1016 } 1017 } 1018 1019 /* 1020 * Sending 1021 */ 1022 1023 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6) 1024 { 1025 struct sock *sk = skb->sk; 1026 struct udphdr *uh; 1027 int err = 0; 1028 int is_udplite = IS_UDPLITE(sk); 1029 __wsum csum = 0; 1030 int offset = skb_transport_offset(skb); 1031 int len = skb->len - offset; 1032 1033 /* 1034 * Create a UDP header 1035 */ 1036 uh = udp_hdr(skb); 1037 uh->source = fl6->fl6_sport; 1038 uh->dest = fl6->fl6_dport; 1039 uh->len = htons(len); 1040 uh->check = 0; 1041 1042 if (is_udplite) 1043 csum = udplite_csum(skb); 1044 else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */ 1045 skb->ip_summed = CHECKSUM_NONE; 1046 goto send; 1047 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 1048 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len); 1049 goto send; 1050 } else 1051 csum = udp_csum(skb); 1052 1053 /* add protocol-dependent pseudo-header */ 1054 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr, 1055 len, fl6->flowi6_proto, csum); 1056 if (uh->check == 0) 1057 uh->check = CSUM_MANGLED_0; 1058 1059 send: 1060 err = ip6_send_skb(skb); 1061 if (err) { 1062 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) { 1063 UDP6_INC_STATS(sock_net(sk), 1064 UDP_MIB_SNDBUFERRORS, is_udplite); 1065 err = 0; 1066 } 1067 } else { 1068 UDP6_INC_STATS(sock_net(sk), 1069 UDP_MIB_OUTDATAGRAMS, is_udplite); 1070 } 1071 return err; 1072 } 1073 1074 static int udp_v6_push_pending_frames(struct sock *sk) 1075 { 1076 struct sk_buff *skb; 1077 struct udp_sock *up = udp_sk(sk); 1078 struct flowi6 fl6; 1079 int err = 0; 1080 1081 if (up->pending == AF_INET) 1082 return udp_push_pending_frames(sk); 1083 1084 /* ip6_finish_skb will release the cork, so make a copy of 1085 * fl6 here. 1086 */ 1087 fl6 = inet_sk(sk)->cork.fl.u.ip6; 1088 1089 skb = ip6_finish_skb(sk); 1090 if (!skb) 1091 goto out; 1092 1093 err = udp_v6_send_skb(skb, &fl6); 1094 1095 out: 1096 up->len = 0; 1097 up->pending = 0; 1098 return err; 1099 } 1100 1101 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 1102 { 1103 struct ipv6_txoptions opt_space; 1104 struct udp_sock *up = udp_sk(sk); 1105 struct inet_sock *inet = inet_sk(sk); 1106 struct ipv6_pinfo *np = inet6_sk(sk); 1107 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 1108 struct in6_addr *daddr, *final_p, final; 1109 struct ipv6_txoptions *opt = NULL; 1110 struct ipv6_txoptions *opt_to_free = NULL; 1111 struct ip6_flowlabel *flowlabel = NULL; 1112 struct flowi6 fl6; 1113 struct dst_entry *dst; 1114 struct ipcm6_cookie ipc6; 1115 int addr_len = msg->msg_namelen; 1116 int ulen = len; 1117 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 1118 int err; 1119 int connected = 0; 1120 int is_udplite = IS_UDPLITE(sk); 1121 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 1122 struct sockcm_cookie sockc; 1123 1124 ipc6.hlimit = -1; 1125 ipc6.tclass = -1; 1126 ipc6.dontfrag = -1; 1127 sockc.tsflags = sk->sk_tsflags; 1128 1129 /* destination address check */ 1130 if (sin6) { 1131 if (addr_len < offsetof(struct sockaddr, sa_data)) 1132 return -EINVAL; 1133 1134 switch (sin6->sin6_family) { 1135 case AF_INET6: 1136 if (addr_len < SIN6_LEN_RFC2133) 1137 return -EINVAL; 1138 daddr = &sin6->sin6_addr; 1139 if (ipv6_addr_any(daddr) && 1140 ipv6_addr_v4mapped(&np->saddr)) 1141 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), 1142 daddr); 1143 break; 1144 case AF_INET: 1145 goto do_udp_sendmsg; 1146 case AF_UNSPEC: 1147 msg->msg_name = sin6 = NULL; 1148 msg->msg_namelen = addr_len = 0; 1149 daddr = NULL; 1150 break; 1151 default: 1152 return -EINVAL; 1153 } 1154 } else if (!up->pending) { 1155 if (sk->sk_state != TCP_ESTABLISHED) 1156 return -EDESTADDRREQ; 1157 daddr = &sk->sk_v6_daddr; 1158 } else 1159 daddr = NULL; 1160 1161 if (daddr) { 1162 if (ipv6_addr_v4mapped(daddr)) { 1163 struct sockaddr_in sin; 1164 sin.sin_family = AF_INET; 1165 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport; 1166 sin.sin_addr.s_addr = daddr->s6_addr32[3]; 1167 msg->msg_name = &sin; 1168 msg->msg_namelen = sizeof(sin); 1169 do_udp_sendmsg: 1170 if (__ipv6_only_sock(sk)) 1171 return -ENETUNREACH; 1172 return udp_sendmsg(sk, msg, len); 1173 } 1174 } 1175 1176 if (up->pending == AF_INET) 1177 return udp_sendmsg(sk, msg, len); 1178 1179 /* Rough check on arithmetic overflow, 1180 better check is made in ip6_append_data(). 1181 */ 1182 if (len > INT_MAX - sizeof(struct udphdr)) 1183 return -EMSGSIZE; 1184 1185 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 1186 if (up->pending) { 1187 /* 1188 * There are pending frames. 1189 * The socket lock must be held while it's corked. 1190 */ 1191 lock_sock(sk); 1192 if (likely(up->pending)) { 1193 if (unlikely(up->pending != AF_INET6)) { 1194 release_sock(sk); 1195 return -EAFNOSUPPORT; 1196 } 1197 dst = NULL; 1198 goto do_append_data; 1199 } 1200 release_sock(sk); 1201 } 1202 ulen += sizeof(struct udphdr); 1203 1204 memset(&fl6, 0, sizeof(fl6)); 1205 1206 if (sin6) { 1207 if (sin6->sin6_port == 0) 1208 return -EINVAL; 1209 1210 fl6.fl6_dport = sin6->sin6_port; 1211 daddr = &sin6->sin6_addr; 1212 1213 if (np->sndflow) { 1214 fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK; 1215 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 1216 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 1217 if (!flowlabel) 1218 return -EINVAL; 1219 } 1220 } 1221 1222 /* 1223 * Otherwise it will be difficult to maintain 1224 * sk->sk_dst_cache. 1225 */ 1226 if (sk->sk_state == TCP_ESTABLISHED && 1227 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 1228 daddr = &sk->sk_v6_daddr; 1229 1230 if (addr_len >= sizeof(struct sockaddr_in6) && 1231 sin6->sin6_scope_id && 1232 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr))) 1233 fl6.flowi6_oif = sin6->sin6_scope_id; 1234 } else { 1235 if (sk->sk_state != TCP_ESTABLISHED) 1236 return -EDESTADDRREQ; 1237 1238 fl6.fl6_dport = inet->inet_dport; 1239 daddr = &sk->sk_v6_daddr; 1240 fl6.flowlabel = np->flow_label; 1241 connected = 1; 1242 } 1243 1244 if (!fl6.flowi6_oif) 1245 fl6.flowi6_oif = sk->sk_bound_dev_if; 1246 1247 if (!fl6.flowi6_oif) 1248 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex; 1249 1250 fl6.flowi6_mark = sk->sk_mark; 1251 fl6.flowi6_uid = sk->sk_uid; 1252 1253 if (msg->msg_controllen) { 1254 opt = &opt_space; 1255 memset(opt, 0, sizeof(struct ipv6_txoptions)); 1256 opt->tot_len = sizeof(*opt); 1257 ipc6.opt = opt; 1258 1259 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, &sockc); 1260 if (err < 0) { 1261 fl6_sock_release(flowlabel); 1262 return err; 1263 } 1264 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) { 1265 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 1266 if (!flowlabel) 1267 return -EINVAL; 1268 } 1269 if (!(opt->opt_nflen|opt->opt_flen)) 1270 opt = NULL; 1271 connected = 0; 1272 } 1273 if (!opt) { 1274 opt = txopt_get(np); 1275 opt_to_free = opt; 1276 } 1277 if (flowlabel) 1278 opt = fl6_merge_options(&opt_space, flowlabel, opt); 1279 opt = ipv6_fixup_options(&opt_space, opt); 1280 ipc6.opt = opt; 1281 1282 fl6.flowi6_proto = sk->sk_protocol; 1283 if (!ipv6_addr_any(daddr)) 1284 fl6.daddr = *daddr; 1285 else 1286 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 1287 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 1288 fl6.saddr = np->saddr; 1289 fl6.fl6_sport = inet->inet_sport; 1290 1291 final_p = fl6_update_dst(&fl6, opt, &final); 1292 if (final_p) 1293 connected = 0; 1294 1295 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) { 1296 fl6.flowi6_oif = np->mcast_oif; 1297 connected = 0; 1298 } else if (!fl6.flowi6_oif) 1299 fl6.flowi6_oif = np->ucast_oif; 1300 1301 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 1302 1303 if (ipc6.tclass < 0) 1304 ipc6.tclass = np->tclass; 1305 1306 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 1307 1308 dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p); 1309 if (IS_ERR(dst)) { 1310 err = PTR_ERR(dst); 1311 dst = NULL; 1312 goto out; 1313 } 1314 1315 if (ipc6.hlimit < 0) 1316 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 1317 1318 if (msg->msg_flags&MSG_CONFIRM) 1319 goto do_confirm; 1320 back_from_confirm: 1321 1322 /* Lockless fast path for the non-corking case */ 1323 if (!corkreq) { 1324 struct sk_buff *skb; 1325 1326 skb = ip6_make_skb(sk, getfrag, msg, ulen, 1327 sizeof(struct udphdr), &ipc6, 1328 &fl6, (struct rt6_info *)dst, 1329 msg->msg_flags, &sockc); 1330 err = PTR_ERR(skb); 1331 if (!IS_ERR_OR_NULL(skb)) 1332 err = udp_v6_send_skb(skb, &fl6); 1333 goto release_dst; 1334 } 1335 1336 lock_sock(sk); 1337 if (unlikely(up->pending)) { 1338 /* The socket is already corked while preparing it. */ 1339 /* ... which is an evident application bug. --ANK */ 1340 release_sock(sk); 1341 1342 net_dbg_ratelimited("udp cork app bug 2\n"); 1343 err = -EINVAL; 1344 goto out; 1345 } 1346 1347 up->pending = AF_INET6; 1348 1349 do_append_data: 1350 if (ipc6.dontfrag < 0) 1351 ipc6.dontfrag = np->dontfrag; 1352 up->len += ulen; 1353 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr), 1354 &ipc6, &fl6, (struct rt6_info *)dst, 1355 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, &sockc); 1356 if (err) 1357 udp_v6_flush_pending_frames(sk); 1358 else if (!corkreq) 1359 err = udp_v6_push_pending_frames(sk); 1360 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1361 up->pending = 0; 1362 1363 if (err > 0) 1364 err = np->recverr ? net_xmit_errno(err) : 0; 1365 release_sock(sk); 1366 1367 release_dst: 1368 if (dst) { 1369 if (connected) { 1370 ip6_dst_store(sk, dst, 1371 ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ? 1372 &sk->sk_v6_daddr : NULL, 1373 #ifdef CONFIG_IPV6_SUBTREES 1374 ipv6_addr_equal(&fl6.saddr, &np->saddr) ? 1375 &np->saddr : 1376 #endif 1377 NULL); 1378 } else { 1379 dst_release(dst); 1380 } 1381 dst = NULL; 1382 } 1383 1384 out: 1385 dst_release(dst); 1386 fl6_sock_release(flowlabel); 1387 txopt_put(opt_to_free); 1388 if (!err) 1389 return len; 1390 /* 1391 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1392 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1393 * we don't have a good statistic (IpOutDiscards but it can be too many 1394 * things). We could add another new stat but at least for now that 1395 * seems like overkill. 1396 */ 1397 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1398 UDP6_INC_STATS(sock_net(sk), 1399 UDP_MIB_SNDBUFERRORS, is_udplite); 1400 } 1401 return err; 1402 1403 do_confirm: 1404 if (msg->msg_flags & MSG_PROBE) 1405 dst_confirm_neigh(dst, &fl6.daddr); 1406 if (!(msg->msg_flags&MSG_PROBE) || len) 1407 goto back_from_confirm; 1408 err = 0; 1409 goto out; 1410 } 1411 1412 void udpv6_destroy_sock(struct sock *sk) 1413 { 1414 struct udp_sock *up = udp_sk(sk); 1415 lock_sock(sk); 1416 udp_v6_flush_pending_frames(sk); 1417 release_sock(sk); 1418 1419 if (static_key_false(&udpv6_encap_needed) && up->encap_type) { 1420 void (*encap_destroy)(struct sock *sk); 1421 encap_destroy = ACCESS_ONCE(up->encap_destroy); 1422 if (encap_destroy) 1423 encap_destroy(sk); 1424 } 1425 1426 inet6_destroy_sock(sk); 1427 } 1428 1429 /* 1430 * Socket option code for UDP 1431 */ 1432 int udpv6_setsockopt(struct sock *sk, int level, int optname, 1433 char __user *optval, unsigned int optlen) 1434 { 1435 if (level == SOL_UDP || level == SOL_UDPLITE) 1436 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1437 udp_v6_push_pending_frames); 1438 return ipv6_setsockopt(sk, level, optname, optval, optlen); 1439 } 1440 1441 #ifdef CONFIG_COMPAT 1442 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname, 1443 char __user *optval, unsigned int optlen) 1444 { 1445 if (level == SOL_UDP || level == SOL_UDPLITE) 1446 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1447 udp_v6_push_pending_frames); 1448 return compat_ipv6_setsockopt(sk, level, optname, optval, optlen); 1449 } 1450 #endif 1451 1452 int udpv6_getsockopt(struct sock *sk, int level, int optname, 1453 char __user *optval, int __user *optlen) 1454 { 1455 if (level == SOL_UDP || level == SOL_UDPLITE) 1456 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1457 return ipv6_getsockopt(sk, level, optname, optval, optlen); 1458 } 1459 1460 #ifdef CONFIG_COMPAT 1461 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname, 1462 char __user *optval, int __user *optlen) 1463 { 1464 if (level == SOL_UDP || level == SOL_UDPLITE) 1465 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1466 return compat_ipv6_getsockopt(sk, level, optname, optval, optlen); 1467 } 1468 #endif 1469 1470 static struct inet6_protocol udpv6_protocol = { 1471 .early_demux = udp_v6_early_demux, 1472 .early_demux_handler = udp_v6_early_demux, 1473 .handler = udpv6_rcv, 1474 .err_handler = udpv6_err, 1475 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 1476 }; 1477 1478 /* ------------------------------------------------------------------------ */ 1479 #ifdef CONFIG_PROC_FS 1480 int udp6_seq_show(struct seq_file *seq, void *v) 1481 { 1482 if (v == SEQ_START_TOKEN) { 1483 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER); 1484 } else { 1485 int bucket = ((struct udp_iter_state *)seq->private)->bucket; 1486 struct inet_sock *inet = inet_sk(v); 1487 __u16 srcp = ntohs(inet->inet_sport); 1488 __u16 destp = ntohs(inet->inet_dport); 1489 ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket); 1490 } 1491 return 0; 1492 } 1493 1494 static const struct file_operations udp6_afinfo_seq_fops = { 1495 .owner = THIS_MODULE, 1496 .open = udp_seq_open, 1497 .read = seq_read, 1498 .llseek = seq_lseek, 1499 .release = seq_release_net 1500 }; 1501 1502 static struct udp_seq_afinfo udp6_seq_afinfo = { 1503 .name = "udp6", 1504 .family = AF_INET6, 1505 .udp_table = &udp_table, 1506 .seq_fops = &udp6_afinfo_seq_fops, 1507 .seq_ops = { 1508 .show = udp6_seq_show, 1509 }, 1510 }; 1511 1512 int __net_init udp6_proc_init(struct net *net) 1513 { 1514 return udp_proc_register(net, &udp6_seq_afinfo); 1515 } 1516 1517 void udp6_proc_exit(struct net *net) 1518 { 1519 udp_proc_unregister(net, &udp6_seq_afinfo); 1520 } 1521 #endif /* CONFIG_PROC_FS */ 1522 1523 /* ------------------------------------------------------------------------ */ 1524 1525 struct proto udpv6_prot = { 1526 .name = "UDPv6", 1527 .owner = THIS_MODULE, 1528 .close = udp_lib_close, 1529 .connect = ip6_datagram_connect, 1530 .disconnect = udp_disconnect, 1531 .ioctl = udp_ioctl, 1532 .init = udp_init_sock, 1533 .destroy = udpv6_destroy_sock, 1534 .setsockopt = udpv6_setsockopt, 1535 .getsockopt = udpv6_getsockopt, 1536 .sendmsg = udpv6_sendmsg, 1537 .recvmsg = udpv6_recvmsg, 1538 .release_cb = ip6_datagram_release_cb, 1539 .hash = udp_lib_hash, 1540 .unhash = udp_lib_unhash, 1541 .rehash = udp_v6_rehash, 1542 .get_port = udp_v6_get_port, 1543 .memory_allocated = &udp_memory_allocated, 1544 .sysctl_mem = sysctl_udp_mem, 1545 .sysctl_wmem = &sysctl_udp_wmem_min, 1546 .sysctl_rmem = &sysctl_udp_rmem_min, 1547 .obj_size = sizeof(struct udp6_sock), 1548 .h.udp_table = &udp_table, 1549 #ifdef CONFIG_COMPAT 1550 .compat_setsockopt = compat_udpv6_setsockopt, 1551 .compat_getsockopt = compat_udpv6_getsockopt, 1552 #endif 1553 .diag_destroy = udp_abort, 1554 }; 1555 1556 static struct inet_protosw udpv6_protosw = { 1557 .type = SOCK_DGRAM, 1558 .protocol = IPPROTO_UDP, 1559 .prot = &udpv6_prot, 1560 .ops = &inet6_dgram_ops, 1561 .flags = INET_PROTOSW_PERMANENT, 1562 }; 1563 1564 int __init udpv6_init(void) 1565 { 1566 int ret; 1567 1568 ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP); 1569 if (ret) 1570 goto out; 1571 1572 ret = inet6_register_protosw(&udpv6_protosw); 1573 if (ret) 1574 goto out_udpv6_protocol; 1575 out: 1576 return ret; 1577 1578 out_udpv6_protocol: 1579 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); 1580 goto out; 1581 } 1582 1583 void udpv6_exit(void) 1584 { 1585 inet6_unregister_protosw(&udpv6_protosw); 1586 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); 1587 } 1588