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, int sdif, 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 bool dev_match = (sk->sk_bound_dev_if == dif || 165 sk->sk_bound_dev_if == sdif); 166 167 if (exact_dif && !dev_match) 168 return -1; 169 if (sk->sk_bound_dev_if && dev_match) 170 score++; 171 } 172 173 if (sk->sk_incoming_cpu == raw_smp_processor_id()) 174 score++; 175 176 return score; 177 } 178 179 /* called with rcu_read_lock() */ 180 static struct sock *udp6_lib_lookup2(struct net *net, 181 const struct in6_addr *saddr, __be16 sport, 182 const struct in6_addr *daddr, unsigned int hnum, 183 int dif, int sdif, bool exact_dif, 184 struct udp_hslot *hslot2, struct sk_buff *skb) 185 { 186 struct sock *sk, *result; 187 int score, badness, matches = 0, reuseport = 0; 188 u32 hash = 0; 189 190 result = NULL; 191 badness = -1; 192 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 193 score = compute_score(sk, net, saddr, sport, 194 daddr, hnum, dif, sdif, exact_dif); 195 if (score > badness) { 196 reuseport = sk->sk_reuseport; 197 if (reuseport) { 198 hash = udp6_ehashfn(net, daddr, hnum, 199 saddr, sport); 200 201 result = reuseport_select_sock(sk, hash, skb, 202 sizeof(struct udphdr)); 203 if (result) 204 return result; 205 matches = 1; 206 } 207 result = sk; 208 badness = score; 209 } else if (score == badness && reuseport) { 210 matches++; 211 if (reciprocal_scale(hash, matches) == 0) 212 result = sk; 213 hash = next_pseudo_random32(hash); 214 } 215 } 216 return result; 217 } 218 219 /* rcu_read_lock() must be held */ 220 struct sock *__udp6_lib_lookup(struct net *net, 221 const struct in6_addr *saddr, __be16 sport, 222 const struct in6_addr *daddr, __be16 dport, 223 int dif, int sdif, struct udp_table *udptable, 224 struct sk_buff *skb) 225 { 226 struct sock *sk, *result; 227 unsigned short hnum = ntohs(dport); 228 unsigned int hash2, slot2, slot = udp_hashfn(net, hnum, udptable->mask); 229 struct udp_hslot *hslot2, *hslot = &udptable->hash[slot]; 230 bool exact_dif = udp6_lib_exact_dif_match(net, skb); 231 int score, badness, matches = 0, reuseport = 0; 232 u32 hash = 0; 233 234 if (hslot->count > 10) { 235 hash2 = udp6_portaddr_hash(net, daddr, hnum); 236 slot2 = hash2 & udptable->mask; 237 hslot2 = &udptable->hash2[slot2]; 238 if (hslot->count < hslot2->count) 239 goto begin; 240 241 result = udp6_lib_lookup2(net, saddr, sport, 242 daddr, hnum, dif, sdif, exact_dif, 243 hslot2, skb); 244 if (!result) { 245 unsigned int old_slot2 = slot2; 246 hash2 = udp6_portaddr_hash(net, &in6addr_any, hnum); 247 slot2 = hash2 & udptable->mask; 248 /* avoid searching the same slot again. */ 249 if (unlikely(slot2 == old_slot2)) 250 return result; 251 252 hslot2 = &udptable->hash2[slot2]; 253 if (hslot->count < hslot2->count) 254 goto begin; 255 256 result = udp6_lib_lookup2(net, saddr, sport, 257 daddr, hnum, dif, sdif, 258 exact_dif, hslot2, 259 skb); 260 } 261 return result; 262 } 263 begin: 264 result = NULL; 265 badness = -1; 266 sk_for_each_rcu(sk, &hslot->head) { 267 score = compute_score(sk, net, saddr, sport, daddr, hnum, dif, 268 sdif, exact_dif); 269 if (score > badness) { 270 reuseport = sk->sk_reuseport; 271 if (reuseport) { 272 hash = udp6_ehashfn(net, daddr, hnum, 273 saddr, sport); 274 result = reuseport_select_sock(sk, hash, skb, 275 sizeof(struct udphdr)); 276 if (result) 277 return result; 278 matches = 1; 279 } 280 result = sk; 281 badness = score; 282 } else if (score == badness && reuseport) { 283 matches++; 284 if (reciprocal_scale(hash, matches) == 0) 285 result = sk; 286 hash = next_pseudo_random32(hash); 287 } 288 } 289 return result; 290 } 291 EXPORT_SYMBOL_GPL(__udp6_lib_lookup); 292 293 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb, 294 __be16 sport, __be16 dport, 295 struct udp_table *udptable) 296 { 297 const struct ipv6hdr *iph = ipv6_hdr(skb); 298 299 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, 300 &iph->daddr, dport, inet6_iif(skb), 301 inet6_sdif(skb), udptable, skb); 302 } 303 304 struct sock *udp6_lib_lookup_skb(struct sk_buff *skb, 305 __be16 sport, __be16 dport) 306 { 307 const struct ipv6hdr *iph = ipv6_hdr(skb); 308 309 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, 310 &iph->daddr, dport, inet6_iif(skb), 311 inet6_sdif(skb), &udp_table, skb); 312 } 313 EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb); 314 315 /* Must be called under rcu_read_lock(). 316 * Does increment socket refcount. 317 */ 318 #if IS_ENABLED(CONFIG_NETFILTER_XT_MATCH_SOCKET) || \ 319 IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TPROXY) || \ 320 IS_ENABLED(CONFIG_NF_SOCKET_IPV6) 321 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, 322 const struct in6_addr *daddr, __be16 dport, int dif) 323 { 324 struct sock *sk; 325 326 sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport, 327 dif, 0, &udp_table, NULL); 328 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) 329 sk = NULL; 330 return sk; 331 } 332 EXPORT_SYMBOL_GPL(udp6_lib_lookup); 333 #endif 334 335 /* do not use the scratch area len for jumbogram: their length execeeds the 336 * scratch area space; note that the IP6CB flags is still in the first 337 * cacheline, so checking for jumbograms is cheap 338 */ 339 static int udp6_skb_len(struct sk_buff *skb) 340 { 341 return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb); 342 } 343 344 /* 345 * This should be easy, if there is something there we 346 * return it, otherwise we block. 347 */ 348 349 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 350 int noblock, int flags, int *addr_len) 351 { 352 struct ipv6_pinfo *np = inet6_sk(sk); 353 struct inet_sock *inet = inet_sk(sk); 354 struct sk_buff *skb; 355 unsigned int ulen, copied; 356 int peeked, peeking, off; 357 int err; 358 int is_udplite = IS_UDPLITE(sk); 359 bool checksum_valid = false; 360 int is_udp4; 361 362 if (flags & MSG_ERRQUEUE) 363 return ipv6_recv_error(sk, msg, len, addr_len); 364 365 if (np->rxpmtu && np->rxopt.bits.rxpmtu) 366 return ipv6_recv_rxpmtu(sk, msg, len, addr_len); 367 368 try_again: 369 peeking = flags & MSG_PEEK; 370 off = sk_peek_offset(sk, flags); 371 skb = __skb_recv_udp(sk, flags, noblock, &peeked, &off, &err); 372 if (!skb) 373 return err; 374 375 ulen = udp6_skb_len(skb); 376 copied = len; 377 if (copied > ulen - off) 378 copied = ulen - off; 379 else if (copied < ulen) 380 msg->msg_flags |= MSG_TRUNC; 381 382 is_udp4 = (skb->protocol == htons(ETH_P_IP)); 383 384 /* 385 * If checksum is needed at all, try to do it while copying the 386 * data. If the data is truncated, or if we only want a partial 387 * coverage checksum (UDP-Lite), do it before the copy. 388 */ 389 390 if (copied < ulen || peeking || 391 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { 392 checksum_valid = udp_skb_csum_unnecessary(skb) || 393 !__udp_lib_checksum_complete(skb); 394 if (!checksum_valid) 395 goto csum_copy_err; 396 } 397 398 if (checksum_valid || udp_skb_csum_unnecessary(skb)) { 399 if (udp_skb_is_linear(skb)) 400 err = copy_linear_skb(skb, copied, off, &msg->msg_iter); 401 else 402 err = skb_copy_datagram_msg(skb, off, msg, copied); 403 } else { 404 err = skb_copy_and_csum_datagram_msg(skb, off, msg); 405 if (err == -EINVAL) 406 goto csum_copy_err; 407 } 408 if (unlikely(err)) { 409 if (!peeked) { 410 atomic_inc(&sk->sk_drops); 411 if (is_udp4) 412 UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, 413 is_udplite); 414 else 415 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, 416 is_udplite); 417 } 418 kfree_skb(skb); 419 return err; 420 } 421 if (!peeked) { 422 if (is_udp4) 423 UDP_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS, 424 is_udplite); 425 else 426 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INDATAGRAMS, 427 is_udplite); 428 } 429 430 sock_recv_ts_and_drops(msg, sk, skb); 431 432 /* Copy the address. */ 433 if (msg->msg_name) { 434 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 435 sin6->sin6_family = AF_INET6; 436 sin6->sin6_port = udp_hdr(skb)->source; 437 sin6->sin6_flowinfo = 0; 438 439 if (is_udp4) { 440 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, 441 &sin6->sin6_addr); 442 sin6->sin6_scope_id = 0; 443 } else { 444 sin6->sin6_addr = ipv6_hdr(skb)->saddr; 445 sin6->sin6_scope_id = 446 ipv6_iface_scope_id(&sin6->sin6_addr, 447 inet6_iif(skb)); 448 } 449 *addr_len = sizeof(*sin6); 450 } 451 452 if (np->rxopt.all) 453 ip6_datagram_recv_common_ctl(sk, msg, skb); 454 455 if (is_udp4) { 456 if (inet->cmsg_flags) 457 ip_cmsg_recv_offset(msg, sk, skb, 458 sizeof(struct udphdr), off); 459 } else { 460 if (np->rxopt.all) 461 ip6_datagram_recv_specific_ctl(sk, msg, skb); 462 } 463 464 err = copied; 465 if (flags & MSG_TRUNC) 466 err = ulen; 467 468 skb_consume_udp(sk, skb, peeking ? -err : err); 469 return err; 470 471 csum_copy_err: 472 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, 473 udp_skb_destructor)) { 474 if (is_udp4) { 475 UDP_INC_STATS(sock_net(sk), 476 UDP_MIB_CSUMERRORS, is_udplite); 477 UDP_INC_STATS(sock_net(sk), 478 UDP_MIB_INERRORS, is_udplite); 479 } else { 480 UDP6_INC_STATS(sock_net(sk), 481 UDP_MIB_CSUMERRORS, is_udplite); 482 UDP6_INC_STATS(sock_net(sk), 483 UDP_MIB_INERRORS, is_udplite); 484 } 485 } 486 kfree_skb(skb); 487 488 /* starting over for a new packet, but check if we need to yield */ 489 cond_resched(); 490 msg->msg_flags &= ~MSG_TRUNC; 491 goto try_again; 492 } 493 494 void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 495 u8 type, u8 code, int offset, __be32 info, 496 struct udp_table *udptable) 497 { 498 struct ipv6_pinfo *np; 499 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; 500 const struct in6_addr *saddr = &hdr->saddr; 501 const struct in6_addr *daddr = &hdr->daddr; 502 struct udphdr *uh = (struct udphdr *)(skb->data+offset); 503 struct sock *sk; 504 int harderr; 505 int err; 506 struct net *net = dev_net(skb->dev); 507 508 sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source, 509 inet6_iif(skb), 0, udptable, skb); 510 if (!sk) { 511 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), 512 ICMP6_MIB_INERRORS); 513 return; 514 } 515 516 harderr = icmpv6_err_convert(type, code, &err); 517 np = inet6_sk(sk); 518 519 if (type == ICMPV6_PKT_TOOBIG) { 520 if (!ip6_sk_accept_pmtu(sk)) 521 goto out; 522 ip6_sk_update_pmtu(skb, sk, info); 523 if (np->pmtudisc != IPV6_PMTUDISC_DONT) 524 harderr = 1; 525 } 526 if (type == NDISC_REDIRECT) { 527 ip6_sk_redirect(skb, sk); 528 goto out; 529 } 530 531 if (!np->recverr) { 532 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 533 goto out; 534 } else { 535 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1)); 536 } 537 538 sk->sk_err = err; 539 sk->sk_error_report(sk); 540 out: 541 return; 542 } 543 544 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 545 { 546 int rc; 547 548 if (!ipv6_addr_any(&sk->sk_v6_daddr)) { 549 sock_rps_save_rxhash(sk, skb); 550 sk_mark_napi_id(sk, skb); 551 sk_incoming_cpu_update(sk); 552 } else { 553 sk_mark_napi_id_once(sk, skb); 554 } 555 556 rc = __udp_enqueue_schedule_skb(sk, skb); 557 if (rc < 0) { 558 int is_udplite = IS_UDPLITE(sk); 559 560 /* Note that an ENOMEM error is charged twice */ 561 if (rc == -ENOMEM) 562 UDP6_INC_STATS(sock_net(sk), 563 UDP_MIB_RCVBUFERRORS, is_udplite); 564 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 565 kfree_skb(skb); 566 return -1; 567 } 568 569 return 0; 570 } 571 572 static __inline__ void udpv6_err(struct sk_buff *skb, 573 struct inet6_skb_parm *opt, u8 type, 574 u8 code, int offset, __be32 info) 575 { 576 __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table); 577 } 578 579 static struct static_key udpv6_encap_needed __read_mostly; 580 void udpv6_encap_enable(void) 581 { 582 static_key_enable(&udpv6_encap_needed); 583 } 584 EXPORT_SYMBOL(udpv6_encap_enable); 585 586 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 587 { 588 struct udp_sock *up = udp_sk(sk); 589 int is_udplite = IS_UDPLITE(sk); 590 591 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 592 goto drop; 593 594 if (static_key_false(&udpv6_encap_needed) && up->encap_type) { 595 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 596 597 /* 598 * This is an encapsulation socket so pass the skb to 599 * the socket's udp_encap_rcv() hook. Otherwise, just 600 * fall through and pass this up the UDP socket. 601 * up->encap_rcv() returns the following value: 602 * =0 if skb was successfully passed to the encap 603 * handler or was discarded by it. 604 * >0 if skb should be passed on to UDP. 605 * <0 if skb should be resubmitted as proto -N 606 */ 607 608 /* if we're overly short, let UDP handle it */ 609 encap_rcv = ACCESS_ONCE(up->encap_rcv); 610 if (encap_rcv) { 611 int ret; 612 613 /* Verify checksum before giving to encap */ 614 if (udp_lib_checksum_complete(skb)) 615 goto csum_error; 616 617 ret = encap_rcv(sk, skb); 618 if (ret <= 0) { 619 __UDP_INC_STATS(sock_net(sk), 620 UDP_MIB_INDATAGRAMS, 621 is_udplite); 622 return -ret; 623 } 624 } 625 626 /* FALLTHROUGH -- it's a UDP Packet */ 627 } 628 629 /* 630 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c). 631 */ 632 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 633 634 if (up->pcrlen == 0) { /* full coverage was set */ 635 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n", 636 UDP_SKB_CB(skb)->cscov, skb->len); 637 goto drop; 638 } 639 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 640 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n", 641 UDP_SKB_CB(skb)->cscov, up->pcrlen); 642 goto drop; 643 } 644 } 645 646 prefetch(&sk->sk_rmem_alloc); 647 if (rcu_access_pointer(sk->sk_filter) && 648 udp_lib_checksum_complete(skb)) 649 goto csum_error; 650 651 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) 652 goto drop; 653 654 udp_csum_pull_header(skb); 655 656 skb_dst_drop(skb); 657 658 return __udpv6_queue_rcv_skb(sk, skb); 659 660 csum_error: 661 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 662 drop: 663 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 664 atomic_inc(&sk->sk_drops); 665 kfree_skb(skb); 666 return -1; 667 } 668 669 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk, 670 __be16 loc_port, const struct in6_addr *loc_addr, 671 __be16 rmt_port, const struct in6_addr *rmt_addr, 672 int dif, unsigned short hnum) 673 { 674 struct inet_sock *inet = inet_sk(sk); 675 676 if (!net_eq(sock_net(sk), net)) 677 return false; 678 679 if (udp_sk(sk)->udp_port_hash != hnum || 680 sk->sk_family != PF_INET6 || 681 (inet->inet_dport && inet->inet_dport != rmt_port) || 682 (!ipv6_addr_any(&sk->sk_v6_daddr) && 683 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) || 684 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) || 685 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 686 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr))) 687 return false; 688 if (!inet6_mc_check(sk, loc_addr, rmt_addr)) 689 return false; 690 return true; 691 } 692 693 static void udp6_csum_zero_error(struct sk_buff *skb) 694 { 695 /* RFC 2460 section 8.1 says that we SHOULD log 696 * this error. Well, it is reasonable. 697 */ 698 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n", 699 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source), 700 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest)); 701 } 702 703 /* 704 * Note: called only from the BH handler context, 705 * so we don't need to lock the hashes. 706 */ 707 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 708 const struct in6_addr *saddr, const struct in6_addr *daddr, 709 struct udp_table *udptable, int proto) 710 { 711 struct sock *sk, *first = NULL; 712 const struct udphdr *uh = udp_hdr(skb); 713 unsigned short hnum = ntohs(uh->dest); 714 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); 715 unsigned int offset = offsetof(typeof(*sk), sk_node); 716 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); 717 int dif = inet6_iif(skb); 718 struct hlist_node *node; 719 struct sk_buff *nskb; 720 721 if (use_hash2) { 722 hash2_any = udp6_portaddr_hash(net, &in6addr_any, hnum) & 723 udptable->mask; 724 hash2 = udp6_portaddr_hash(net, daddr, hnum) & udptable->mask; 725 start_lookup: 726 hslot = &udptable->hash2[hash2]; 727 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); 728 } 729 730 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { 731 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr, 732 uh->source, saddr, dif, hnum)) 733 continue; 734 /* If zero checksum and no_check is not on for 735 * the socket then skip it. 736 */ 737 if (!uh->check && !udp_sk(sk)->no_check6_rx) 738 continue; 739 if (!first) { 740 first = sk; 741 continue; 742 } 743 nskb = skb_clone(skb, GFP_ATOMIC); 744 if (unlikely(!nskb)) { 745 atomic_inc(&sk->sk_drops); 746 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS, 747 IS_UDPLITE(sk)); 748 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, 749 IS_UDPLITE(sk)); 750 continue; 751 } 752 753 if (udpv6_queue_rcv_skb(sk, nskb) > 0) 754 consume_skb(nskb); 755 } 756 757 /* Also lookup *:port if we are using hash2 and haven't done so yet. */ 758 if (use_hash2 && hash2 != hash2_any) { 759 hash2 = hash2_any; 760 goto start_lookup; 761 } 762 763 if (first) { 764 if (udpv6_queue_rcv_skb(first, skb) > 0) 765 consume_skb(skb); 766 } else { 767 kfree_skb(skb); 768 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI, 769 proto == IPPROTO_UDPLITE); 770 } 771 return 0; 772 } 773 774 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) 775 { 776 if (udp_sk_rx_dst_set(sk, dst)) { 777 const struct rt6_info *rt = (const struct rt6_info *)dst; 778 779 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt); 780 } 781 } 782 783 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 784 int proto) 785 { 786 const struct in6_addr *saddr, *daddr; 787 struct net *net = dev_net(skb->dev); 788 struct udphdr *uh; 789 struct sock *sk; 790 u32 ulen = 0; 791 792 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 793 goto discard; 794 795 saddr = &ipv6_hdr(skb)->saddr; 796 daddr = &ipv6_hdr(skb)->daddr; 797 uh = udp_hdr(skb); 798 799 ulen = ntohs(uh->len); 800 if (ulen > skb->len) 801 goto short_packet; 802 803 if (proto == IPPROTO_UDP) { 804 /* UDP validates ulen. */ 805 806 /* Check for jumbo payload */ 807 if (ulen == 0) 808 ulen = skb->len; 809 810 if (ulen < sizeof(*uh)) 811 goto short_packet; 812 813 if (ulen < skb->len) { 814 if (pskb_trim_rcsum(skb, ulen)) 815 goto short_packet; 816 saddr = &ipv6_hdr(skb)->saddr; 817 daddr = &ipv6_hdr(skb)->daddr; 818 uh = udp_hdr(skb); 819 } 820 } 821 822 if (udp6_csum_init(skb, uh, proto)) 823 goto csum_error; 824 825 /* Check if the socket is already available, e.g. due to early demux */ 826 sk = skb_steal_sock(skb); 827 if (sk) { 828 struct dst_entry *dst = skb_dst(skb); 829 int ret; 830 831 if (unlikely(sk->sk_rx_dst != dst)) 832 udp6_sk_rx_dst_set(sk, dst); 833 834 ret = udpv6_queue_rcv_skb(sk, skb); 835 sock_put(sk); 836 837 /* a return value > 0 means to resubmit the input */ 838 if (ret > 0) 839 return ret; 840 return 0; 841 } 842 843 /* 844 * Multicast receive code 845 */ 846 if (ipv6_addr_is_multicast(daddr)) 847 return __udp6_lib_mcast_deliver(net, skb, 848 saddr, daddr, udptable, proto); 849 850 /* Unicast */ 851 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 852 if (sk) { 853 int ret; 854 855 if (!uh->check && !udp_sk(sk)->no_check6_rx) { 856 udp6_csum_zero_error(skb); 857 goto csum_error; 858 } 859 860 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) 861 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check, 862 ip6_compute_pseudo); 863 864 ret = udpv6_queue_rcv_skb(sk, skb); 865 866 /* a return value > 0 means to resubmit the input */ 867 if (ret > 0) 868 return ret; 869 870 return 0; 871 } 872 873 if (!uh->check) { 874 udp6_csum_zero_error(skb); 875 goto csum_error; 876 } 877 878 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 879 goto discard; 880 881 if (udp_lib_checksum_complete(skb)) 882 goto csum_error; 883 884 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 885 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 886 887 kfree_skb(skb); 888 return 0; 889 890 short_packet: 891 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n", 892 proto == IPPROTO_UDPLITE ? "-Lite" : "", 893 saddr, ntohs(uh->source), 894 ulen, skb->len, 895 daddr, ntohs(uh->dest)); 896 goto discard; 897 csum_error: 898 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 899 discard: 900 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 901 kfree_skb(skb); 902 return 0; 903 } 904 905 906 static struct sock *__udp6_lib_demux_lookup(struct net *net, 907 __be16 loc_port, const struct in6_addr *loc_addr, 908 __be16 rmt_port, const struct in6_addr *rmt_addr, 909 int dif, int sdif) 910 { 911 unsigned short hnum = ntohs(loc_port); 912 unsigned int hash2 = udp6_portaddr_hash(net, loc_addr, hnum); 913 unsigned int slot2 = hash2 & udp_table.mask; 914 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 915 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 916 struct sock *sk; 917 918 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 919 if (sk->sk_state == TCP_ESTABLISHED && 920 INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif)) 921 return sk; 922 /* Only check first socket in chain */ 923 break; 924 } 925 return NULL; 926 } 927 928 static void udp_v6_early_demux(struct sk_buff *skb) 929 { 930 struct net *net = dev_net(skb->dev); 931 const struct udphdr *uh; 932 struct sock *sk; 933 struct dst_entry *dst; 934 int dif = skb->dev->ifindex; 935 int sdif = inet6_sdif(skb); 936 937 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 938 sizeof(struct udphdr))) 939 return; 940 941 uh = udp_hdr(skb); 942 943 if (skb->pkt_type == PACKET_HOST) 944 sk = __udp6_lib_demux_lookup(net, uh->dest, 945 &ipv6_hdr(skb)->daddr, 946 uh->source, &ipv6_hdr(skb)->saddr, 947 dif, sdif); 948 else 949 return; 950 951 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) 952 return; 953 954 skb->sk = sk; 955 skb->destructor = sock_efree; 956 dst = READ_ONCE(sk->sk_rx_dst); 957 958 if (dst) 959 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie); 960 if (dst) { 961 /* set noref for now. 962 * any place which wants to hold dst has to call 963 * dst_hold_safe() 964 */ 965 skb_dst_set_noref(skb, dst); 966 } 967 } 968 969 static __inline__ int udpv6_rcv(struct sk_buff *skb) 970 { 971 return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP); 972 } 973 974 /* 975 * Throw away all pending data and cancel the corking. Socket is locked. 976 */ 977 static void udp_v6_flush_pending_frames(struct sock *sk) 978 { 979 struct udp_sock *up = udp_sk(sk); 980 981 if (up->pending == AF_INET) 982 udp_flush_pending_frames(sk); 983 else if (up->pending) { 984 up->len = 0; 985 up->pending = 0; 986 ip6_flush_pending_frames(sk); 987 } 988 } 989 990 /** 991 * udp6_hwcsum_outgoing - handle outgoing HW checksumming 992 * @sk: socket we are sending on 993 * @skb: sk_buff containing the filled-in UDP header 994 * (checksum field must be zeroed out) 995 */ 996 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, 997 const struct in6_addr *saddr, 998 const struct in6_addr *daddr, int len) 999 { 1000 unsigned int offset; 1001 struct udphdr *uh = udp_hdr(skb); 1002 struct sk_buff *frags = skb_shinfo(skb)->frag_list; 1003 __wsum csum = 0; 1004 1005 if (!frags) { 1006 /* Only one fragment on the socket. */ 1007 skb->csum_start = skb_transport_header(skb) - skb->head; 1008 skb->csum_offset = offsetof(struct udphdr, check); 1009 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0); 1010 } else { 1011 /* 1012 * HW-checksum won't work as there are two or more 1013 * fragments on the socket so that all csums of sk_buffs 1014 * should be together 1015 */ 1016 offset = skb_transport_offset(skb); 1017 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); 1018 csum = skb->csum; 1019 1020 skb->ip_summed = CHECKSUM_NONE; 1021 1022 do { 1023 csum = csum_add(csum, frags->csum); 1024 } while ((frags = frags->next)); 1025 1026 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 1027 csum); 1028 if (uh->check == 0) 1029 uh->check = CSUM_MANGLED_0; 1030 } 1031 } 1032 1033 /* 1034 * Sending 1035 */ 1036 1037 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6) 1038 { 1039 struct sock *sk = skb->sk; 1040 struct udphdr *uh; 1041 int err = 0; 1042 int is_udplite = IS_UDPLITE(sk); 1043 __wsum csum = 0; 1044 int offset = skb_transport_offset(skb); 1045 int len = skb->len - offset; 1046 1047 /* 1048 * Create a UDP header 1049 */ 1050 uh = udp_hdr(skb); 1051 uh->source = fl6->fl6_sport; 1052 uh->dest = fl6->fl6_dport; 1053 uh->len = htons(len); 1054 uh->check = 0; 1055 1056 if (is_udplite) 1057 csum = udplite_csum(skb); 1058 else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */ 1059 skb->ip_summed = CHECKSUM_NONE; 1060 goto send; 1061 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 1062 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len); 1063 goto send; 1064 } else 1065 csum = udp_csum(skb); 1066 1067 /* add protocol-dependent pseudo-header */ 1068 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr, 1069 len, fl6->flowi6_proto, csum); 1070 if (uh->check == 0) 1071 uh->check = CSUM_MANGLED_0; 1072 1073 send: 1074 err = ip6_send_skb(skb); 1075 if (err) { 1076 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) { 1077 UDP6_INC_STATS(sock_net(sk), 1078 UDP_MIB_SNDBUFERRORS, is_udplite); 1079 err = 0; 1080 } 1081 } else { 1082 UDP6_INC_STATS(sock_net(sk), 1083 UDP_MIB_OUTDATAGRAMS, is_udplite); 1084 } 1085 return err; 1086 } 1087 1088 static int udp_v6_push_pending_frames(struct sock *sk) 1089 { 1090 struct sk_buff *skb; 1091 struct udp_sock *up = udp_sk(sk); 1092 struct flowi6 fl6; 1093 int err = 0; 1094 1095 if (up->pending == AF_INET) 1096 return udp_push_pending_frames(sk); 1097 1098 /* ip6_finish_skb will release the cork, so make a copy of 1099 * fl6 here. 1100 */ 1101 fl6 = inet_sk(sk)->cork.fl.u.ip6; 1102 1103 skb = ip6_finish_skb(sk); 1104 if (!skb) 1105 goto out; 1106 1107 err = udp_v6_send_skb(skb, &fl6); 1108 1109 out: 1110 up->len = 0; 1111 up->pending = 0; 1112 return err; 1113 } 1114 1115 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 1116 { 1117 struct ipv6_txoptions opt_space; 1118 struct udp_sock *up = udp_sk(sk); 1119 struct inet_sock *inet = inet_sk(sk); 1120 struct ipv6_pinfo *np = inet6_sk(sk); 1121 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 1122 struct in6_addr *daddr, *final_p, final; 1123 struct ipv6_txoptions *opt = NULL; 1124 struct ipv6_txoptions *opt_to_free = NULL; 1125 struct ip6_flowlabel *flowlabel = NULL; 1126 struct flowi6 fl6; 1127 struct dst_entry *dst; 1128 struct ipcm6_cookie ipc6; 1129 int addr_len = msg->msg_namelen; 1130 int ulen = len; 1131 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 1132 int err; 1133 int connected = 0; 1134 int is_udplite = IS_UDPLITE(sk); 1135 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 1136 struct sockcm_cookie sockc; 1137 1138 ipc6.hlimit = -1; 1139 ipc6.tclass = -1; 1140 ipc6.dontfrag = -1; 1141 sockc.tsflags = sk->sk_tsflags; 1142 1143 /* destination address check */ 1144 if (sin6) { 1145 if (addr_len < offsetof(struct sockaddr, sa_data)) 1146 return -EINVAL; 1147 1148 switch (sin6->sin6_family) { 1149 case AF_INET6: 1150 if (addr_len < SIN6_LEN_RFC2133) 1151 return -EINVAL; 1152 daddr = &sin6->sin6_addr; 1153 if (ipv6_addr_any(daddr) && 1154 ipv6_addr_v4mapped(&np->saddr)) 1155 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), 1156 daddr); 1157 break; 1158 case AF_INET: 1159 goto do_udp_sendmsg; 1160 case AF_UNSPEC: 1161 msg->msg_name = sin6 = NULL; 1162 msg->msg_namelen = addr_len = 0; 1163 daddr = NULL; 1164 break; 1165 default: 1166 return -EINVAL; 1167 } 1168 } else if (!up->pending) { 1169 if (sk->sk_state != TCP_ESTABLISHED) 1170 return -EDESTADDRREQ; 1171 daddr = &sk->sk_v6_daddr; 1172 } else 1173 daddr = NULL; 1174 1175 if (daddr) { 1176 if (ipv6_addr_v4mapped(daddr)) { 1177 struct sockaddr_in sin; 1178 sin.sin_family = AF_INET; 1179 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport; 1180 sin.sin_addr.s_addr = daddr->s6_addr32[3]; 1181 msg->msg_name = &sin; 1182 msg->msg_namelen = sizeof(sin); 1183 do_udp_sendmsg: 1184 if (__ipv6_only_sock(sk)) 1185 return -ENETUNREACH; 1186 return udp_sendmsg(sk, msg, len); 1187 } 1188 } 1189 1190 if (up->pending == AF_INET) 1191 return udp_sendmsg(sk, msg, len); 1192 1193 /* Rough check on arithmetic overflow, 1194 better check is made in ip6_append_data(). 1195 */ 1196 if (len > INT_MAX - sizeof(struct udphdr)) 1197 return -EMSGSIZE; 1198 1199 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 1200 if (up->pending) { 1201 /* 1202 * There are pending frames. 1203 * The socket lock must be held while it's corked. 1204 */ 1205 lock_sock(sk); 1206 if (likely(up->pending)) { 1207 if (unlikely(up->pending != AF_INET6)) { 1208 release_sock(sk); 1209 return -EAFNOSUPPORT; 1210 } 1211 dst = NULL; 1212 goto do_append_data; 1213 } 1214 release_sock(sk); 1215 } 1216 ulen += sizeof(struct udphdr); 1217 1218 memset(&fl6, 0, sizeof(fl6)); 1219 1220 if (sin6) { 1221 if (sin6->sin6_port == 0) 1222 return -EINVAL; 1223 1224 fl6.fl6_dport = sin6->sin6_port; 1225 daddr = &sin6->sin6_addr; 1226 1227 if (np->sndflow) { 1228 fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK; 1229 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 1230 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 1231 if (!flowlabel) 1232 return -EINVAL; 1233 } 1234 } 1235 1236 /* 1237 * Otherwise it will be difficult to maintain 1238 * sk->sk_dst_cache. 1239 */ 1240 if (sk->sk_state == TCP_ESTABLISHED && 1241 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 1242 daddr = &sk->sk_v6_daddr; 1243 1244 if (addr_len >= sizeof(struct sockaddr_in6) && 1245 sin6->sin6_scope_id && 1246 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr))) 1247 fl6.flowi6_oif = sin6->sin6_scope_id; 1248 } else { 1249 if (sk->sk_state != TCP_ESTABLISHED) 1250 return -EDESTADDRREQ; 1251 1252 fl6.fl6_dport = inet->inet_dport; 1253 daddr = &sk->sk_v6_daddr; 1254 fl6.flowlabel = np->flow_label; 1255 connected = 1; 1256 } 1257 1258 if (!fl6.flowi6_oif) 1259 fl6.flowi6_oif = sk->sk_bound_dev_if; 1260 1261 if (!fl6.flowi6_oif) 1262 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex; 1263 1264 fl6.flowi6_mark = sk->sk_mark; 1265 fl6.flowi6_uid = sk->sk_uid; 1266 1267 if (msg->msg_controllen) { 1268 opt = &opt_space; 1269 memset(opt, 0, sizeof(struct ipv6_txoptions)); 1270 opt->tot_len = sizeof(*opt); 1271 ipc6.opt = opt; 1272 1273 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, &sockc); 1274 if (err < 0) { 1275 fl6_sock_release(flowlabel); 1276 return err; 1277 } 1278 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) { 1279 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 1280 if (!flowlabel) 1281 return -EINVAL; 1282 } 1283 if (!(opt->opt_nflen|opt->opt_flen)) 1284 opt = NULL; 1285 connected = 0; 1286 } 1287 if (!opt) { 1288 opt = txopt_get(np); 1289 opt_to_free = opt; 1290 } 1291 if (flowlabel) 1292 opt = fl6_merge_options(&opt_space, flowlabel, opt); 1293 opt = ipv6_fixup_options(&opt_space, opt); 1294 ipc6.opt = opt; 1295 1296 fl6.flowi6_proto = sk->sk_protocol; 1297 if (!ipv6_addr_any(daddr)) 1298 fl6.daddr = *daddr; 1299 else 1300 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 1301 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 1302 fl6.saddr = np->saddr; 1303 fl6.fl6_sport = inet->inet_sport; 1304 1305 final_p = fl6_update_dst(&fl6, opt, &final); 1306 if (final_p) 1307 connected = 0; 1308 1309 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) { 1310 fl6.flowi6_oif = np->mcast_oif; 1311 connected = 0; 1312 } else if (!fl6.flowi6_oif) 1313 fl6.flowi6_oif = np->ucast_oif; 1314 1315 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 1316 1317 if (ipc6.tclass < 0) 1318 ipc6.tclass = np->tclass; 1319 1320 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 1321 1322 dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p); 1323 if (IS_ERR(dst)) { 1324 err = PTR_ERR(dst); 1325 dst = NULL; 1326 goto out; 1327 } 1328 1329 if (ipc6.hlimit < 0) 1330 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 1331 1332 if (msg->msg_flags&MSG_CONFIRM) 1333 goto do_confirm; 1334 back_from_confirm: 1335 1336 /* Lockless fast path for the non-corking case */ 1337 if (!corkreq) { 1338 struct sk_buff *skb; 1339 1340 skb = ip6_make_skb(sk, getfrag, msg, ulen, 1341 sizeof(struct udphdr), &ipc6, 1342 &fl6, (struct rt6_info *)dst, 1343 msg->msg_flags, &sockc); 1344 err = PTR_ERR(skb); 1345 if (!IS_ERR_OR_NULL(skb)) 1346 err = udp_v6_send_skb(skb, &fl6); 1347 goto release_dst; 1348 } 1349 1350 lock_sock(sk); 1351 if (unlikely(up->pending)) { 1352 /* The socket is already corked while preparing it. */ 1353 /* ... which is an evident application bug. --ANK */ 1354 release_sock(sk); 1355 1356 net_dbg_ratelimited("udp cork app bug 2\n"); 1357 err = -EINVAL; 1358 goto out; 1359 } 1360 1361 up->pending = AF_INET6; 1362 1363 do_append_data: 1364 if (ipc6.dontfrag < 0) 1365 ipc6.dontfrag = np->dontfrag; 1366 up->len += ulen; 1367 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr), 1368 &ipc6, &fl6, (struct rt6_info *)dst, 1369 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, &sockc); 1370 if (err) 1371 udp_v6_flush_pending_frames(sk); 1372 else if (!corkreq) 1373 err = udp_v6_push_pending_frames(sk); 1374 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1375 up->pending = 0; 1376 1377 if (err > 0) 1378 err = np->recverr ? net_xmit_errno(err) : 0; 1379 release_sock(sk); 1380 1381 release_dst: 1382 if (dst) { 1383 if (connected) { 1384 ip6_dst_store(sk, dst, 1385 ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ? 1386 &sk->sk_v6_daddr : NULL, 1387 #ifdef CONFIG_IPV6_SUBTREES 1388 ipv6_addr_equal(&fl6.saddr, &np->saddr) ? 1389 &np->saddr : 1390 #endif 1391 NULL); 1392 } else { 1393 dst_release(dst); 1394 } 1395 dst = NULL; 1396 } 1397 1398 out: 1399 dst_release(dst); 1400 fl6_sock_release(flowlabel); 1401 txopt_put(opt_to_free); 1402 if (!err) 1403 return len; 1404 /* 1405 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1406 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1407 * we don't have a good statistic (IpOutDiscards but it can be too many 1408 * things). We could add another new stat but at least for now that 1409 * seems like overkill. 1410 */ 1411 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1412 UDP6_INC_STATS(sock_net(sk), 1413 UDP_MIB_SNDBUFERRORS, is_udplite); 1414 } 1415 return err; 1416 1417 do_confirm: 1418 if (msg->msg_flags & MSG_PROBE) 1419 dst_confirm_neigh(dst, &fl6.daddr); 1420 if (!(msg->msg_flags&MSG_PROBE) || len) 1421 goto back_from_confirm; 1422 err = 0; 1423 goto out; 1424 } 1425 1426 void udpv6_destroy_sock(struct sock *sk) 1427 { 1428 struct udp_sock *up = udp_sk(sk); 1429 lock_sock(sk); 1430 udp_v6_flush_pending_frames(sk); 1431 release_sock(sk); 1432 1433 if (static_key_false(&udpv6_encap_needed) && up->encap_type) { 1434 void (*encap_destroy)(struct sock *sk); 1435 encap_destroy = ACCESS_ONCE(up->encap_destroy); 1436 if (encap_destroy) 1437 encap_destroy(sk); 1438 } 1439 1440 inet6_destroy_sock(sk); 1441 } 1442 1443 /* 1444 * Socket option code for UDP 1445 */ 1446 int udpv6_setsockopt(struct sock *sk, int level, int optname, 1447 char __user *optval, unsigned int optlen) 1448 { 1449 if (level == SOL_UDP || level == SOL_UDPLITE) 1450 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1451 udp_v6_push_pending_frames); 1452 return ipv6_setsockopt(sk, level, optname, optval, optlen); 1453 } 1454 1455 #ifdef CONFIG_COMPAT 1456 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname, 1457 char __user *optval, unsigned int optlen) 1458 { 1459 if (level == SOL_UDP || level == SOL_UDPLITE) 1460 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1461 udp_v6_push_pending_frames); 1462 return compat_ipv6_setsockopt(sk, level, optname, optval, optlen); 1463 } 1464 #endif 1465 1466 int udpv6_getsockopt(struct sock *sk, int level, int optname, 1467 char __user *optval, int __user *optlen) 1468 { 1469 if (level == SOL_UDP || level == SOL_UDPLITE) 1470 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1471 return ipv6_getsockopt(sk, level, optname, optval, optlen); 1472 } 1473 1474 #ifdef CONFIG_COMPAT 1475 int compat_udpv6_getsockopt(struct sock *sk, int level, int optname, 1476 char __user *optval, int __user *optlen) 1477 { 1478 if (level == SOL_UDP || level == SOL_UDPLITE) 1479 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1480 return compat_ipv6_getsockopt(sk, level, optname, optval, optlen); 1481 } 1482 #endif 1483 1484 /* thinking of making this const? Don't. 1485 * early_demux can change based on sysctl. 1486 */ 1487 static struct inet6_protocol udpv6_protocol = { 1488 .early_demux = udp_v6_early_demux, 1489 .early_demux_handler = udp_v6_early_demux, 1490 .handler = udpv6_rcv, 1491 .err_handler = udpv6_err, 1492 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 1493 }; 1494 1495 /* ------------------------------------------------------------------------ */ 1496 #ifdef CONFIG_PROC_FS 1497 int udp6_seq_show(struct seq_file *seq, void *v) 1498 { 1499 if (v == SEQ_START_TOKEN) { 1500 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER); 1501 } else { 1502 int bucket = ((struct udp_iter_state *)seq->private)->bucket; 1503 struct inet_sock *inet = inet_sk(v); 1504 __u16 srcp = ntohs(inet->inet_sport); 1505 __u16 destp = ntohs(inet->inet_dport); 1506 ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket); 1507 } 1508 return 0; 1509 } 1510 1511 static const struct file_operations udp6_afinfo_seq_fops = { 1512 .owner = THIS_MODULE, 1513 .open = udp_seq_open, 1514 .read = seq_read, 1515 .llseek = seq_lseek, 1516 .release = seq_release_net 1517 }; 1518 1519 static struct udp_seq_afinfo udp6_seq_afinfo = { 1520 .name = "udp6", 1521 .family = AF_INET6, 1522 .udp_table = &udp_table, 1523 .seq_fops = &udp6_afinfo_seq_fops, 1524 .seq_ops = { 1525 .show = udp6_seq_show, 1526 }, 1527 }; 1528 1529 int __net_init udp6_proc_init(struct net *net) 1530 { 1531 return udp_proc_register(net, &udp6_seq_afinfo); 1532 } 1533 1534 void udp6_proc_exit(struct net *net) 1535 { 1536 udp_proc_unregister(net, &udp6_seq_afinfo); 1537 } 1538 #endif /* CONFIG_PROC_FS */ 1539 1540 /* ------------------------------------------------------------------------ */ 1541 1542 struct proto udpv6_prot = { 1543 .name = "UDPv6", 1544 .owner = THIS_MODULE, 1545 .close = udp_lib_close, 1546 .connect = ip6_datagram_connect, 1547 .disconnect = udp_disconnect, 1548 .ioctl = udp_ioctl, 1549 .init = udp_init_sock, 1550 .destroy = udpv6_destroy_sock, 1551 .setsockopt = udpv6_setsockopt, 1552 .getsockopt = udpv6_getsockopt, 1553 .sendmsg = udpv6_sendmsg, 1554 .recvmsg = udpv6_recvmsg, 1555 .release_cb = ip6_datagram_release_cb, 1556 .hash = udp_lib_hash, 1557 .unhash = udp_lib_unhash, 1558 .rehash = udp_v6_rehash, 1559 .get_port = udp_v6_get_port, 1560 .memory_allocated = &udp_memory_allocated, 1561 .sysctl_mem = sysctl_udp_mem, 1562 .sysctl_wmem = &sysctl_udp_wmem_min, 1563 .sysctl_rmem = &sysctl_udp_rmem_min, 1564 .obj_size = sizeof(struct udp6_sock), 1565 .h.udp_table = &udp_table, 1566 #ifdef CONFIG_COMPAT 1567 .compat_setsockopt = compat_udpv6_setsockopt, 1568 .compat_getsockopt = compat_udpv6_getsockopt, 1569 #endif 1570 .diag_destroy = udp_abort, 1571 }; 1572 1573 static struct inet_protosw udpv6_protosw = { 1574 .type = SOCK_DGRAM, 1575 .protocol = IPPROTO_UDP, 1576 .prot = &udpv6_prot, 1577 .ops = &inet6_dgram_ops, 1578 .flags = INET_PROTOSW_PERMANENT, 1579 }; 1580 1581 int __init udpv6_init(void) 1582 { 1583 int ret; 1584 1585 ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP); 1586 if (ret) 1587 goto out; 1588 1589 ret = inet6_register_protosw(&udpv6_protosw); 1590 if (ret) 1591 goto out_udpv6_protocol; 1592 out: 1593 return ret; 1594 1595 out_udpv6_protocol: 1596 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); 1597 goto out; 1598 } 1599 1600 void udpv6_exit(void) 1601 { 1602 inet6_unregister_protosw(&udpv6_protosw); 1603 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); 1604 } 1605