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 if (!static_key_enabled(&udpv6_encap_needed)) 583 static_key_slow_inc(&udpv6_encap_needed); 584 } 585 EXPORT_SYMBOL(udpv6_encap_enable); 586 587 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 588 { 589 struct udp_sock *up = udp_sk(sk); 590 int is_udplite = IS_UDPLITE(sk); 591 592 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 593 goto drop; 594 595 if (static_key_false(&udpv6_encap_needed) && up->encap_type) { 596 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 597 598 /* 599 * This is an encapsulation socket so pass the skb to 600 * the socket's udp_encap_rcv() hook. Otherwise, just 601 * fall through and pass this up the UDP socket. 602 * up->encap_rcv() returns the following value: 603 * =0 if skb was successfully passed to the encap 604 * handler or was discarded by it. 605 * >0 if skb should be passed on to UDP. 606 * <0 if skb should be resubmitted as proto -N 607 */ 608 609 /* if we're overly short, let UDP handle it */ 610 encap_rcv = ACCESS_ONCE(up->encap_rcv); 611 if (encap_rcv) { 612 int ret; 613 614 /* Verify checksum before giving to encap */ 615 if (udp_lib_checksum_complete(skb)) 616 goto csum_error; 617 618 ret = encap_rcv(sk, skb); 619 if (ret <= 0) { 620 __UDP_INC_STATS(sock_net(sk), 621 UDP_MIB_INDATAGRAMS, 622 is_udplite); 623 return -ret; 624 } 625 } 626 627 /* FALLTHROUGH -- it's a UDP Packet */ 628 } 629 630 /* 631 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c). 632 */ 633 if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 634 635 if (up->pcrlen == 0) { /* full coverage was set */ 636 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n", 637 UDP_SKB_CB(skb)->cscov, skb->len); 638 goto drop; 639 } 640 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 641 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n", 642 UDP_SKB_CB(skb)->cscov, up->pcrlen); 643 goto drop; 644 } 645 } 646 647 prefetch(&sk->sk_rmem_alloc); 648 if (rcu_access_pointer(sk->sk_filter) && 649 udp_lib_checksum_complete(skb)) 650 goto csum_error; 651 652 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) 653 goto drop; 654 655 udp_csum_pull_header(skb); 656 657 skb_dst_drop(skb); 658 659 return __udpv6_queue_rcv_skb(sk, skb); 660 661 csum_error: 662 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 663 drop: 664 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 665 atomic_inc(&sk->sk_drops); 666 kfree_skb(skb); 667 return -1; 668 } 669 670 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk, 671 __be16 loc_port, const struct in6_addr *loc_addr, 672 __be16 rmt_port, const struct in6_addr *rmt_addr, 673 int dif, unsigned short hnum) 674 { 675 struct inet_sock *inet = inet_sk(sk); 676 677 if (!net_eq(sock_net(sk), net)) 678 return false; 679 680 if (udp_sk(sk)->udp_port_hash != hnum || 681 sk->sk_family != PF_INET6 || 682 (inet->inet_dport && inet->inet_dport != rmt_port) || 683 (!ipv6_addr_any(&sk->sk_v6_daddr) && 684 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) || 685 (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif) || 686 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 687 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr))) 688 return false; 689 if (!inet6_mc_check(sk, loc_addr, rmt_addr)) 690 return false; 691 return true; 692 } 693 694 static void udp6_csum_zero_error(struct sk_buff *skb) 695 { 696 /* RFC 2460 section 8.1 says that we SHOULD log 697 * this error. Well, it is reasonable. 698 */ 699 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n", 700 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source), 701 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest)); 702 } 703 704 /* 705 * Note: called only from the BH handler context, 706 * so we don't need to lock the hashes. 707 */ 708 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 709 const struct in6_addr *saddr, const struct in6_addr *daddr, 710 struct udp_table *udptable, int proto) 711 { 712 struct sock *sk, *first = NULL; 713 const struct udphdr *uh = udp_hdr(skb); 714 unsigned short hnum = ntohs(uh->dest); 715 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); 716 unsigned int offset = offsetof(typeof(*sk), sk_node); 717 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); 718 int dif = inet6_iif(skb); 719 struct hlist_node *node; 720 struct sk_buff *nskb; 721 722 if (use_hash2) { 723 hash2_any = udp6_portaddr_hash(net, &in6addr_any, hnum) & 724 udptable->mask; 725 hash2 = udp6_portaddr_hash(net, daddr, hnum) & udptable->mask; 726 start_lookup: 727 hslot = &udptable->hash2[hash2]; 728 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); 729 } 730 731 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { 732 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr, 733 uh->source, saddr, dif, hnum)) 734 continue; 735 /* If zero checksum and no_check is not on for 736 * the socket then skip it. 737 */ 738 if (!uh->check && !udp_sk(sk)->no_check6_rx) 739 continue; 740 if (!first) { 741 first = sk; 742 continue; 743 } 744 nskb = skb_clone(skb, GFP_ATOMIC); 745 if (unlikely(!nskb)) { 746 atomic_inc(&sk->sk_drops); 747 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS, 748 IS_UDPLITE(sk)); 749 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, 750 IS_UDPLITE(sk)); 751 continue; 752 } 753 754 if (udpv6_queue_rcv_skb(sk, nskb) > 0) 755 consume_skb(nskb); 756 } 757 758 /* Also lookup *:port if we are using hash2 and haven't done so yet. */ 759 if (use_hash2 && hash2 != hash2_any) { 760 hash2 = hash2_any; 761 goto start_lookup; 762 } 763 764 if (first) { 765 if (udpv6_queue_rcv_skb(first, skb) > 0) 766 consume_skb(skb); 767 } else { 768 kfree_skb(skb); 769 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI, 770 proto == IPPROTO_UDPLITE); 771 } 772 return 0; 773 } 774 775 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 776 int proto) 777 { 778 const struct in6_addr *saddr, *daddr; 779 struct net *net = dev_net(skb->dev); 780 struct udphdr *uh; 781 struct sock *sk; 782 u32 ulen = 0; 783 784 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 785 goto discard; 786 787 saddr = &ipv6_hdr(skb)->saddr; 788 daddr = &ipv6_hdr(skb)->daddr; 789 uh = udp_hdr(skb); 790 791 ulen = ntohs(uh->len); 792 if (ulen > skb->len) 793 goto short_packet; 794 795 if (proto == IPPROTO_UDP) { 796 /* UDP validates ulen. */ 797 798 /* Check for jumbo payload */ 799 if (ulen == 0) 800 ulen = skb->len; 801 802 if (ulen < sizeof(*uh)) 803 goto short_packet; 804 805 if (ulen < skb->len) { 806 if (pskb_trim_rcsum(skb, ulen)) 807 goto short_packet; 808 saddr = &ipv6_hdr(skb)->saddr; 809 daddr = &ipv6_hdr(skb)->daddr; 810 uh = udp_hdr(skb); 811 } 812 } 813 814 if (udp6_csum_init(skb, uh, proto)) 815 goto csum_error; 816 817 /* Check if the socket is already available, e.g. due to early demux */ 818 sk = skb_steal_sock(skb); 819 if (sk) { 820 struct dst_entry *dst = skb_dst(skb); 821 int ret; 822 823 if (unlikely(sk->sk_rx_dst != dst)) 824 udp_sk_rx_dst_set(sk, dst); 825 826 ret = udpv6_queue_rcv_skb(sk, skb); 827 sock_put(sk); 828 829 /* a return value > 0 means to resubmit the input */ 830 if (ret > 0) 831 return ret; 832 return 0; 833 } 834 835 /* 836 * Multicast receive code 837 */ 838 if (ipv6_addr_is_multicast(daddr)) 839 return __udp6_lib_mcast_deliver(net, skb, 840 saddr, daddr, udptable, proto); 841 842 /* Unicast */ 843 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 844 if (sk) { 845 int ret; 846 847 if (!uh->check && !udp_sk(sk)->no_check6_rx) { 848 udp6_csum_zero_error(skb); 849 goto csum_error; 850 } 851 852 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) 853 skb_checksum_try_convert(skb, IPPROTO_UDP, uh->check, 854 ip6_compute_pseudo); 855 856 ret = udpv6_queue_rcv_skb(sk, skb); 857 858 /* a return value > 0 means to resubmit the input */ 859 if (ret > 0) 860 return ret; 861 862 return 0; 863 } 864 865 if (!uh->check) { 866 udp6_csum_zero_error(skb); 867 goto csum_error; 868 } 869 870 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 871 goto discard; 872 873 if (udp_lib_checksum_complete(skb)) 874 goto csum_error; 875 876 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 877 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 878 879 kfree_skb(skb); 880 return 0; 881 882 short_packet: 883 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n", 884 proto == IPPROTO_UDPLITE ? "-Lite" : "", 885 saddr, ntohs(uh->source), 886 ulen, skb->len, 887 daddr, ntohs(uh->dest)); 888 goto discard; 889 csum_error: 890 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 891 discard: 892 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 893 kfree_skb(skb); 894 return 0; 895 } 896 897 898 static struct sock *__udp6_lib_demux_lookup(struct net *net, 899 __be16 loc_port, const struct in6_addr *loc_addr, 900 __be16 rmt_port, const struct in6_addr *rmt_addr, 901 int dif, int sdif) 902 { 903 unsigned short hnum = ntohs(loc_port); 904 unsigned int hash2 = udp6_portaddr_hash(net, loc_addr, hnum); 905 unsigned int slot2 = hash2 & udp_table.mask; 906 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 907 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 908 struct sock *sk; 909 910 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 911 if (sk->sk_state == TCP_ESTABLISHED && 912 INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif)) 913 return sk; 914 /* Only check first socket in chain */ 915 break; 916 } 917 return NULL; 918 } 919 920 static void udp_v6_early_demux(struct sk_buff *skb) 921 { 922 struct net *net = dev_net(skb->dev); 923 const struct udphdr *uh; 924 struct sock *sk; 925 struct dst_entry *dst; 926 int dif = skb->dev->ifindex; 927 int sdif = inet6_sdif(skb); 928 929 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 930 sizeof(struct udphdr))) 931 return; 932 933 uh = udp_hdr(skb); 934 935 if (skb->pkt_type == PACKET_HOST) 936 sk = __udp6_lib_demux_lookup(net, uh->dest, 937 &ipv6_hdr(skb)->daddr, 938 uh->source, &ipv6_hdr(skb)->saddr, 939 dif, sdif); 940 else 941 return; 942 943 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) 944 return; 945 946 skb->sk = sk; 947 skb->destructor = sock_efree; 948 dst = READ_ONCE(sk->sk_rx_dst); 949 950 if (dst) 951 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie); 952 if (dst) { 953 /* set noref for now. 954 * any place which wants to hold dst has to call 955 * dst_hold_safe() 956 */ 957 skb_dst_set_noref(skb, dst); 958 } 959 } 960 961 static __inline__ int udpv6_rcv(struct sk_buff *skb) 962 { 963 return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP); 964 } 965 966 /* 967 * Throw away all pending data and cancel the corking. Socket is locked. 968 */ 969 static void udp_v6_flush_pending_frames(struct sock *sk) 970 { 971 struct udp_sock *up = udp_sk(sk); 972 973 if (up->pending == AF_INET) 974 udp_flush_pending_frames(sk); 975 else if (up->pending) { 976 up->len = 0; 977 up->pending = 0; 978 ip6_flush_pending_frames(sk); 979 } 980 } 981 982 /** 983 * udp6_hwcsum_outgoing - handle outgoing HW checksumming 984 * @sk: socket we are sending on 985 * @skb: sk_buff containing the filled-in UDP header 986 * (checksum field must be zeroed out) 987 */ 988 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, 989 const struct in6_addr *saddr, 990 const struct in6_addr *daddr, int len) 991 { 992 unsigned int offset; 993 struct udphdr *uh = udp_hdr(skb); 994 struct sk_buff *frags = skb_shinfo(skb)->frag_list; 995 __wsum csum = 0; 996 997 if (!frags) { 998 /* Only one fragment on the socket. */ 999 skb->csum_start = skb_transport_header(skb) - skb->head; 1000 skb->csum_offset = offsetof(struct udphdr, check); 1001 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0); 1002 } else { 1003 /* 1004 * HW-checksum won't work as there are two or more 1005 * fragments on the socket so that all csums of sk_buffs 1006 * should be together 1007 */ 1008 offset = skb_transport_offset(skb); 1009 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); 1010 1011 skb->ip_summed = CHECKSUM_NONE; 1012 1013 do { 1014 csum = csum_add(csum, frags->csum); 1015 } while ((frags = frags->next)); 1016 1017 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 1018 csum); 1019 if (uh->check == 0) 1020 uh->check = CSUM_MANGLED_0; 1021 } 1022 } 1023 1024 /* 1025 * Sending 1026 */ 1027 1028 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6) 1029 { 1030 struct sock *sk = skb->sk; 1031 struct udphdr *uh; 1032 int err = 0; 1033 int is_udplite = IS_UDPLITE(sk); 1034 __wsum csum = 0; 1035 int offset = skb_transport_offset(skb); 1036 int len = skb->len - offset; 1037 1038 /* 1039 * Create a UDP header 1040 */ 1041 uh = udp_hdr(skb); 1042 uh->source = fl6->fl6_sport; 1043 uh->dest = fl6->fl6_dport; 1044 uh->len = htons(len); 1045 uh->check = 0; 1046 1047 if (is_udplite) 1048 csum = udplite_csum(skb); 1049 else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */ 1050 skb->ip_summed = CHECKSUM_NONE; 1051 goto send; 1052 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 1053 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len); 1054 goto send; 1055 } else 1056 csum = udp_csum(skb); 1057 1058 /* add protocol-dependent pseudo-header */ 1059 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr, 1060 len, fl6->flowi6_proto, csum); 1061 if (uh->check == 0) 1062 uh->check = CSUM_MANGLED_0; 1063 1064 send: 1065 err = ip6_send_skb(skb); 1066 if (err) { 1067 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) { 1068 UDP6_INC_STATS(sock_net(sk), 1069 UDP_MIB_SNDBUFERRORS, is_udplite); 1070 err = 0; 1071 } 1072 } else { 1073 UDP6_INC_STATS(sock_net(sk), 1074 UDP_MIB_OUTDATAGRAMS, is_udplite); 1075 } 1076 return err; 1077 } 1078 1079 static int udp_v6_push_pending_frames(struct sock *sk) 1080 { 1081 struct sk_buff *skb; 1082 struct udp_sock *up = udp_sk(sk); 1083 struct flowi6 fl6; 1084 int err = 0; 1085 1086 if (up->pending == AF_INET) 1087 return udp_push_pending_frames(sk); 1088 1089 /* ip6_finish_skb will release the cork, so make a copy of 1090 * fl6 here. 1091 */ 1092 fl6 = inet_sk(sk)->cork.fl.u.ip6; 1093 1094 skb = ip6_finish_skb(sk); 1095 if (!skb) 1096 goto out; 1097 1098 err = udp_v6_send_skb(skb, &fl6); 1099 1100 out: 1101 up->len = 0; 1102 up->pending = 0; 1103 return err; 1104 } 1105 1106 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 1107 { 1108 struct ipv6_txoptions opt_space; 1109 struct udp_sock *up = udp_sk(sk); 1110 struct inet_sock *inet = inet_sk(sk); 1111 struct ipv6_pinfo *np = inet6_sk(sk); 1112 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 1113 struct in6_addr *daddr, *final_p, final; 1114 struct ipv6_txoptions *opt = NULL; 1115 struct ipv6_txoptions *opt_to_free = NULL; 1116 struct ip6_flowlabel *flowlabel = NULL; 1117 struct flowi6 fl6; 1118 struct dst_entry *dst; 1119 struct ipcm6_cookie ipc6; 1120 int addr_len = msg->msg_namelen; 1121 int ulen = len; 1122 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 1123 int err; 1124 int connected = 0; 1125 int is_udplite = IS_UDPLITE(sk); 1126 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 1127 struct sockcm_cookie sockc; 1128 1129 ipc6.hlimit = -1; 1130 ipc6.tclass = -1; 1131 ipc6.dontfrag = -1; 1132 sockc.tsflags = sk->sk_tsflags; 1133 1134 /* destination address check */ 1135 if (sin6) { 1136 if (addr_len < offsetof(struct sockaddr, sa_data)) 1137 return -EINVAL; 1138 1139 switch (sin6->sin6_family) { 1140 case AF_INET6: 1141 if (addr_len < SIN6_LEN_RFC2133) 1142 return -EINVAL; 1143 daddr = &sin6->sin6_addr; 1144 if (ipv6_addr_any(daddr) && 1145 ipv6_addr_v4mapped(&np->saddr)) 1146 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), 1147 daddr); 1148 break; 1149 case AF_INET: 1150 goto do_udp_sendmsg; 1151 case AF_UNSPEC: 1152 msg->msg_name = sin6 = NULL; 1153 msg->msg_namelen = addr_len = 0; 1154 daddr = NULL; 1155 break; 1156 default: 1157 return -EINVAL; 1158 } 1159 } else if (!up->pending) { 1160 if (sk->sk_state != TCP_ESTABLISHED) 1161 return -EDESTADDRREQ; 1162 daddr = &sk->sk_v6_daddr; 1163 } else 1164 daddr = NULL; 1165 1166 if (daddr) { 1167 if (ipv6_addr_v4mapped(daddr)) { 1168 struct sockaddr_in sin; 1169 sin.sin_family = AF_INET; 1170 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport; 1171 sin.sin_addr.s_addr = daddr->s6_addr32[3]; 1172 msg->msg_name = &sin; 1173 msg->msg_namelen = sizeof(sin); 1174 do_udp_sendmsg: 1175 if (__ipv6_only_sock(sk)) 1176 return -ENETUNREACH; 1177 return udp_sendmsg(sk, msg, len); 1178 } 1179 } 1180 1181 if (up->pending == AF_INET) 1182 return udp_sendmsg(sk, msg, len); 1183 1184 /* Rough check on arithmetic overflow, 1185 better check is made in ip6_append_data(). 1186 */ 1187 if (len > INT_MAX - sizeof(struct udphdr)) 1188 return -EMSGSIZE; 1189 1190 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 1191 if (up->pending) { 1192 /* 1193 * There are pending frames. 1194 * The socket lock must be held while it's corked. 1195 */ 1196 lock_sock(sk); 1197 if (likely(up->pending)) { 1198 if (unlikely(up->pending != AF_INET6)) { 1199 release_sock(sk); 1200 return -EAFNOSUPPORT; 1201 } 1202 dst = NULL; 1203 goto do_append_data; 1204 } 1205 release_sock(sk); 1206 } 1207 ulen += sizeof(struct udphdr); 1208 1209 memset(&fl6, 0, sizeof(fl6)); 1210 1211 if (sin6) { 1212 if (sin6->sin6_port == 0) 1213 return -EINVAL; 1214 1215 fl6.fl6_dport = sin6->sin6_port; 1216 daddr = &sin6->sin6_addr; 1217 1218 if (np->sndflow) { 1219 fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK; 1220 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 1221 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 1222 if (!flowlabel) 1223 return -EINVAL; 1224 } 1225 } 1226 1227 /* 1228 * Otherwise it will be difficult to maintain 1229 * sk->sk_dst_cache. 1230 */ 1231 if (sk->sk_state == TCP_ESTABLISHED && 1232 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 1233 daddr = &sk->sk_v6_daddr; 1234 1235 if (addr_len >= sizeof(struct sockaddr_in6) && 1236 sin6->sin6_scope_id && 1237 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr))) 1238 fl6.flowi6_oif = sin6->sin6_scope_id; 1239 } else { 1240 if (sk->sk_state != TCP_ESTABLISHED) 1241 return -EDESTADDRREQ; 1242 1243 fl6.fl6_dport = inet->inet_dport; 1244 daddr = &sk->sk_v6_daddr; 1245 fl6.flowlabel = np->flow_label; 1246 connected = 1; 1247 } 1248 1249 if (!fl6.flowi6_oif) 1250 fl6.flowi6_oif = sk->sk_bound_dev_if; 1251 1252 if (!fl6.flowi6_oif) 1253 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex; 1254 1255 fl6.flowi6_mark = sk->sk_mark; 1256 fl6.flowi6_uid = sk->sk_uid; 1257 1258 if (msg->msg_controllen) { 1259 opt = &opt_space; 1260 memset(opt, 0, sizeof(struct ipv6_txoptions)); 1261 opt->tot_len = sizeof(*opt); 1262 ipc6.opt = opt; 1263 1264 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, &sockc); 1265 if (err < 0) { 1266 fl6_sock_release(flowlabel); 1267 return err; 1268 } 1269 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) { 1270 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 1271 if (!flowlabel) 1272 return -EINVAL; 1273 } 1274 if (!(opt->opt_nflen|opt->opt_flen)) 1275 opt = NULL; 1276 connected = 0; 1277 } 1278 if (!opt) { 1279 opt = txopt_get(np); 1280 opt_to_free = opt; 1281 } 1282 if (flowlabel) 1283 opt = fl6_merge_options(&opt_space, flowlabel, opt); 1284 opt = ipv6_fixup_options(&opt_space, opt); 1285 ipc6.opt = opt; 1286 1287 fl6.flowi6_proto = sk->sk_protocol; 1288 if (!ipv6_addr_any(daddr)) 1289 fl6.daddr = *daddr; 1290 else 1291 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 1292 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 1293 fl6.saddr = np->saddr; 1294 fl6.fl6_sport = inet->inet_sport; 1295 1296 final_p = fl6_update_dst(&fl6, opt, &final); 1297 if (final_p) 1298 connected = 0; 1299 1300 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) { 1301 fl6.flowi6_oif = np->mcast_oif; 1302 connected = 0; 1303 } else if (!fl6.flowi6_oif) 1304 fl6.flowi6_oif = np->ucast_oif; 1305 1306 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 1307 1308 if (ipc6.tclass < 0) 1309 ipc6.tclass = np->tclass; 1310 1311 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 1312 1313 dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p); 1314 if (IS_ERR(dst)) { 1315 err = PTR_ERR(dst); 1316 dst = NULL; 1317 goto out; 1318 } 1319 1320 if (ipc6.hlimit < 0) 1321 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 1322 1323 if (msg->msg_flags&MSG_CONFIRM) 1324 goto do_confirm; 1325 back_from_confirm: 1326 1327 /* Lockless fast path for the non-corking case */ 1328 if (!corkreq) { 1329 struct sk_buff *skb; 1330 1331 skb = ip6_make_skb(sk, getfrag, msg, ulen, 1332 sizeof(struct udphdr), &ipc6, 1333 &fl6, (struct rt6_info *)dst, 1334 msg->msg_flags, &sockc); 1335 err = PTR_ERR(skb); 1336 if (!IS_ERR_OR_NULL(skb)) 1337 err = udp_v6_send_skb(skb, &fl6); 1338 goto release_dst; 1339 } 1340 1341 lock_sock(sk); 1342 if (unlikely(up->pending)) { 1343 /* The socket is already corked while preparing it. */ 1344 /* ... which is an evident application bug. --ANK */ 1345 release_sock(sk); 1346 1347 net_dbg_ratelimited("udp cork app bug 2\n"); 1348 err = -EINVAL; 1349 goto out; 1350 } 1351 1352 up->pending = AF_INET6; 1353 1354 do_append_data: 1355 if (ipc6.dontfrag < 0) 1356 ipc6.dontfrag = np->dontfrag; 1357 up->len += ulen; 1358 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr), 1359 &ipc6, &fl6, (struct rt6_info *)dst, 1360 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags, &sockc); 1361 if (err) 1362 udp_v6_flush_pending_frames(sk); 1363 else if (!corkreq) 1364 err = udp_v6_push_pending_frames(sk); 1365 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1366 up->pending = 0; 1367 1368 if (err > 0) 1369 err = np->recverr ? net_xmit_errno(err) : 0; 1370 release_sock(sk); 1371 1372 release_dst: 1373 if (dst) { 1374 if (connected) { 1375 ip6_dst_store(sk, dst, 1376 ipv6_addr_equal(&fl6.daddr, &sk->sk_v6_daddr) ? 1377 &sk->sk_v6_daddr : NULL, 1378 #ifdef CONFIG_IPV6_SUBTREES 1379 ipv6_addr_equal(&fl6.saddr, &np->saddr) ? 1380 &np->saddr : 1381 #endif 1382 NULL); 1383 } else { 1384 dst_release(dst); 1385 } 1386 dst = NULL; 1387 } 1388 1389 out: 1390 dst_release(dst); 1391 fl6_sock_release(flowlabel); 1392 txopt_put(opt_to_free); 1393 if (!err) 1394 return len; 1395 /* 1396 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1397 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1398 * we don't have a good statistic (IpOutDiscards but it can be too many 1399 * things). We could add another new stat but at least for now that 1400 * seems like overkill. 1401 */ 1402 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1403 UDP6_INC_STATS(sock_net(sk), 1404 UDP_MIB_SNDBUFERRORS, is_udplite); 1405 } 1406 return err; 1407 1408 do_confirm: 1409 if (msg->msg_flags & MSG_PROBE) 1410 dst_confirm_neigh(dst, &fl6.daddr); 1411 if (!(msg->msg_flags&MSG_PROBE) || len) 1412 goto back_from_confirm; 1413 err = 0; 1414 goto out; 1415 } 1416 1417 void udpv6_destroy_sock(struct sock *sk) 1418 { 1419 struct udp_sock *up = udp_sk(sk); 1420 lock_sock(sk); 1421 udp_v6_flush_pending_frames(sk); 1422 release_sock(sk); 1423 1424 if (static_key_false(&udpv6_encap_needed) && up->encap_type) { 1425 void (*encap_destroy)(struct sock *sk); 1426 encap_destroy = ACCESS_ONCE(up->encap_destroy); 1427 if (encap_destroy) 1428 encap_destroy(sk); 1429 } 1430 1431 inet6_destroy_sock(sk); 1432 } 1433 1434 /* 1435 * Socket option code for UDP 1436 */ 1437 int udpv6_setsockopt(struct sock *sk, int level, int optname, 1438 char __user *optval, unsigned int optlen) 1439 { 1440 if (level == SOL_UDP || level == SOL_UDPLITE) 1441 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1442 udp_v6_push_pending_frames); 1443 return ipv6_setsockopt(sk, level, optname, optval, optlen); 1444 } 1445 1446 #ifdef CONFIG_COMPAT 1447 int compat_udpv6_setsockopt(struct sock *sk, int level, int optname, 1448 char __user *optval, unsigned int optlen) 1449 { 1450 if (level == SOL_UDP || level == SOL_UDPLITE) 1451 return udp_lib_setsockopt(sk, level, optname, optval, optlen, 1452 udp_v6_push_pending_frames); 1453 return compat_ipv6_setsockopt(sk, level, optname, optval, optlen); 1454 } 1455 #endif 1456 1457 int udpv6_getsockopt(struct sock *sk, int level, int optname, 1458 char __user *optval, int __user *optlen) 1459 { 1460 if (level == SOL_UDP || level == SOL_UDPLITE) 1461 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1462 return ipv6_getsockopt(sk, level, optname, optval, optlen); 1463 } 1464 1465 #ifdef CONFIG_COMPAT 1466 int compat_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 compat_ipv6_getsockopt(sk, level, optname, optval, optlen); 1472 } 1473 #endif 1474 1475 /* thinking of making this const? Don't. 1476 * early_demux can change based on sysctl. 1477 */ 1478 static struct inet6_protocol udpv6_protocol = { 1479 .early_demux = udp_v6_early_demux, 1480 .early_demux_handler = udp_v6_early_demux, 1481 .handler = udpv6_rcv, 1482 .err_handler = udpv6_err, 1483 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 1484 }; 1485 1486 /* ------------------------------------------------------------------------ */ 1487 #ifdef CONFIG_PROC_FS 1488 int udp6_seq_show(struct seq_file *seq, void *v) 1489 { 1490 if (v == SEQ_START_TOKEN) { 1491 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER); 1492 } else { 1493 int bucket = ((struct udp_iter_state *)seq->private)->bucket; 1494 struct inet_sock *inet = inet_sk(v); 1495 __u16 srcp = ntohs(inet->inet_sport); 1496 __u16 destp = ntohs(inet->inet_dport); 1497 ip6_dgram_sock_seq_show(seq, v, srcp, destp, bucket); 1498 } 1499 return 0; 1500 } 1501 1502 static const struct file_operations udp6_afinfo_seq_fops = { 1503 .owner = THIS_MODULE, 1504 .open = udp_seq_open, 1505 .read = seq_read, 1506 .llseek = seq_lseek, 1507 .release = seq_release_net 1508 }; 1509 1510 static struct udp_seq_afinfo udp6_seq_afinfo = { 1511 .name = "udp6", 1512 .family = AF_INET6, 1513 .udp_table = &udp_table, 1514 .seq_fops = &udp6_afinfo_seq_fops, 1515 .seq_ops = { 1516 .show = udp6_seq_show, 1517 }, 1518 }; 1519 1520 int __net_init udp6_proc_init(struct net *net) 1521 { 1522 return udp_proc_register(net, &udp6_seq_afinfo); 1523 } 1524 1525 void udp6_proc_exit(struct net *net) 1526 { 1527 udp_proc_unregister(net, &udp6_seq_afinfo); 1528 } 1529 #endif /* CONFIG_PROC_FS */ 1530 1531 /* ------------------------------------------------------------------------ */ 1532 1533 struct proto udpv6_prot = { 1534 .name = "UDPv6", 1535 .owner = THIS_MODULE, 1536 .close = udp_lib_close, 1537 .connect = ip6_datagram_connect, 1538 .disconnect = udp_disconnect, 1539 .ioctl = udp_ioctl, 1540 .init = udp_init_sock, 1541 .destroy = udpv6_destroy_sock, 1542 .setsockopt = udpv6_setsockopt, 1543 .getsockopt = udpv6_getsockopt, 1544 .sendmsg = udpv6_sendmsg, 1545 .recvmsg = udpv6_recvmsg, 1546 .release_cb = ip6_datagram_release_cb, 1547 .hash = udp_lib_hash, 1548 .unhash = udp_lib_unhash, 1549 .rehash = udp_v6_rehash, 1550 .get_port = udp_v6_get_port, 1551 .memory_allocated = &udp_memory_allocated, 1552 .sysctl_mem = sysctl_udp_mem, 1553 .sysctl_wmem = &sysctl_udp_wmem_min, 1554 .sysctl_rmem = &sysctl_udp_rmem_min, 1555 .obj_size = sizeof(struct udp6_sock), 1556 .h.udp_table = &udp_table, 1557 #ifdef CONFIG_COMPAT 1558 .compat_setsockopt = compat_udpv6_setsockopt, 1559 .compat_getsockopt = compat_udpv6_getsockopt, 1560 #endif 1561 .diag_destroy = udp_abort, 1562 }; 1563 1564 static struct inet_protosw udpv6_protosw = { 1565 .type = SOCK_DGRAM, 1566 .protocol = IPPROTO_UDP, 1567 .prot = &udpv6_prot, 1568 .ops = &inet6_dgram_ops, 1569 .flags = INET_PROTOSW_PERMANENT, 1570 }; 1571 1572 int __init udpv6_init(void) 1573 { 1574 int ret; 1575 1576 ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP); 1577 if (ret) 1578 goto out; 1579 1580 ret = inet6_register_protosw(&udpv6_protosw); 1581 if (ret) 1582 goto out_udpv6_protocol; 1583 out: 1584 return ret; 1585 1586 out_udpv6_protocol: 1587 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); 1588 goto out; 1589 } 1590 1591 void udpv6_exit(void) 1592 { 1593 inet6_unregister_protosw(&udpv6_protosw); 1594 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); 1595 } 1596