1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * UDP over IPv6 4 * Linux INET6 implementation 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 * 9 * Based on linux/ipv4/udp.c 10 * 11 * Fixes: 12 * Hideaki YOSHIFUJI : sin6_scope_id support 13 * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which 14 * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind 15 * a single port at the same time. 16 * Kazunori MIYAZAWA @USAGI: change process style to use ip6_append_data 17 * YOSHIFUJI Hideaki @USAGI: convert /proc/net/udp6 to seq_file. 18 */ 19 20 #include <linux/errno.h> 21 #include <linux/types.h> 22 #include <linux/socket.h> 23 #include <linux/sockios.h> 24 #include <linux/net.h> 25 #include <linux/in6.h> 26 #include <linux/netdevice.h> 27 #include <linux/if_arp.h> 28 #include <linux/ipv6.h> 29 #include <linux/icmpv6.h> 30 #include <linux/init.h> 31 #include <linux/module.h> 32 #include <linux/skbuff.h> 33 #include <linux/slab.h> 34 #include <linux/uaccess.h> 35 #include <linux/indirect_call_wrapper.h> 36 37 #include <net/addrconf.h> 38 #include <net/ndisc.h> 39 #include <net/protocol.h> 40 #include <net/transp_v6.h> 41 #include <net/ip6_route.h> 42 #include <net/raw.h> 43 #include <net/tcp_states.h> 44 #include <net/ip6_checksum.h> 45 #include <net/ip6_tunnel.h> 46 #include <net/xfrm.h> 47 #include <net/inet_hashtables.h> 48 #include <net/inet6_hashtables.h> 49 #include <net/busy_poll.h> 50 #include <net/sock_reuseport.h> 51 52 #include <linux/proc_fs.h> 53 #include <linux/seq_file.h> 54 #include <trace/events/skb.h> 55 #include "udp_impl.h" 56 57 static u32 udp6_ehashfn(const struct net *net, 58 const struct in6_addr *laddr, 59 const u16 lport, 60 const struct in6_addr *faddr, 61 const __be16 fport) 62 { 63 static u32 udp6_ehash_secret __read_mostly; 64 static u32 udp_ipv6_hash_secret __read_mostly; 65 66 u32 lhash, fhash; 67 68 net_get_random_once(&udp6_ehash_secret, 69 sizeof(udp6_ehash_secret)); 70 net_get_random_once(&udp_ipv6_hash_secret, 71 sizeof(udp_ipv6_hash_secret)); 72 73 lhash = (__force u32)laddr->s6_addr32[3]; 74 fhash = __ipv6_addr_jhash(faddr, udp_ipv6_hash_secret); 75 76 return __inet6_ehashfn(lhash, lport, fhash, fport, 77 udp_ipv6_hash_secret + net_hash_mix(net)); 78 } 79 80 int udp_v6_get_port(struct sock *sk, unsigned short snum) 81 { 82 unsigned int hash2_nulladdr = 83 ipv6_portaddr_hash(sock_net(sk), &in6addr_any, snum); 84 unsigned int hash2_partial = 85 ipv6_portaddr_hash(sock_net(sk), &sk->sk_v6_rcv_saddr, 0); 86 87 /* precompute partial secondary hash */ 88 udp_sk(sk)->udp_portaddr_hash = hash2_partial; 89 return udp_lib_get_port(sk, snum, hash2_nulladdr); 90 } 91 92 void udp_v6_rehash(struct sock *sk) 93 { 94 u16 new_hash = ipv6_portaddr_hash(sock_net(sk), 95 &sk->sk_v6_rcv_saddr, 96 inet_sk(sk)->inet_num); 97 98 udp_lib_rehash(sk, new_hash); 99 } 100 101 static int compute_score(struct sock *sk, struct net *net, 102 const struct in6_addr *saddr, __be16 sport, 103 const struct in6_addr *daddr, unsigned short hnum, 104 int dif, int sdif) 105 { 106 int score; 107 struct inet_sock *inet; 108 bool dev_match; 109 110 if (!net_eq(sock_net(sk), net) || 111 udp_sk(sk)->udp_port_hash != hnum || 112 sk->sk_family != PF_INET6) 113 return -1; 114 115 if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr)) 116 return -1; 117 118 score = 0; 119 inet = inet_sk(sk); 120 121 if (inet->inet_dport) { 122 if (inet->inet_dport != sport) 123 return -1; 124 score++; 125 } 126 127 if (!ipv6_addr_any(&sk->sk_v6_daddr)) { 128 if (!ipv6_addr_equal(&sk->sk_v6_daddr, saddr)) 129 return -1; 130 score++; 131 } 132 133 dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif); 134 if (!dev_match) 135 return -1; 136 score++; 137 138 if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) 139 score++; 140 141 return score; 142 } 143 144 static struct sock *lookup_reuseport(struct net *net, struct sock *sk, 145 struct sk_buff *skb, 146 const struct in6_addr *saddr, 147 __be16 sport, 148 const struct in6_addr *daddr, 149 unsigned int hnum) 150 { 151 struct sock *reuse_sk = NULL; 152 u32 hash; 153 154 if (sk->sk_reuseport && sk->sk_state != TCP_ESTABLISHED) { 155 hash = udp6_ehashfn(net, daddr, hnum, saddr, sport); 156 reuse_sk = reuseport_select_sock(sk, hash, skb, 157 sizeof(struct udphdr)); 158 } 159 return reuse_sk; 160 } 161 162 /* called with rcu_read_lock() */ 163 static struct sock *udp6_lib_lookup2(struct net *net, 164 const struct in6_addr *saddr, __be16 sport, 165 const struct in6_addr *daddr, unsigned int hnum, 166 int dif, int sdif, struct udp_hslot *hslot2, 167 struct sk_buff *skb) 168 { 169 struct sock *sk, *result; 170 int score, badness; 171 172 result = NULL; 173 badness = -1; 174 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 175 score = compute_score(sk, net, saddr, sport, 176 daddr, hnum, dif, sdif); 177 if (score > badness) { 178 result = lookup_reuseport(net, sk, skb, 179 saddr, sport, daddr, hnum); 180 /* Fall back to scoring if group has connections */ 181 if (result && !reuseport_has_conns(sk, false)) 182 return result; 183 184 result = result ? : sk; 185 badness = score; 186 } 187 } 188 return result; 189 } 190 191 static inline struct sock *udp6_lookup_run_bpf(struct net *net, 192 struct udp_table *udptable, 193 struct sk_buff *skb, 194 const struct in6_addr *saddr, 195 __be16 sport, 196 const struct in6_addr *daddr, 197 u16 hnum) 198 { 199 struct sock *sk, *reuse_sk; 200 bool no_reuseport; 201 202 if (udptable != &udp_table) 203 return NULL; /* only UDP is supported */ 204 205 no_reuseport = bpf_sk_lookup_run_v6(net, IPPROTO_UDP, 206 saddr, sport, daddr, hnum, &sk); 207 if (no_reuseport || IS_ERR_OR_NULL(sk)) 208 return sk; 209 210 reuse_sk = lookup_reuseport(net, sk, skb, saddr, sport, daddr, hnum); 211 if (reuse_sk) 212 sk = reuse_sk; 213 return sk; 214 } 215 216 /* rcu_read_lock() must be held */ 217 struct sock *__udp6_lib_lookup(struct net *net, 218 const struct in6_addr *saddr, __be16 sport, 219 const struct in6_addr *daddr, __be16 dport, 220 int dif, int sdif, struct udp_table *udptable, 221 struct sk_buff *skb) 222 { 223 unsigned short hnum = ntohs(dport); 224 unsigned int hash2, slot2; 225 struct udp_hslot *hslot2; 226 struct sock *result, *sk; 227 228 hash2 = ipv6_portaddr_hash(net, daddr, hnum); 229 slot2 = hash2 & udptable->mask; 230 hslot2 = &udptable->hash2[slot2]; 231 232 /* Lookup connected or non-wildcard sockets */ 233 result = udp6_lib_lookup2(net, saddr, sport, 234 daddr, hnum, dif, sdif, 235 hslot2, skb); 236 if (!IS_ERR_OR_NULL(result) && result->sk_state == TCP_ESTABLISHED) 237 goto done; 238 239 /* Lookup redirect from BPF */ 240 if (static_branch_unlikely(&bpf_sk_lookup_enabled)) { 241 sk = udp6_lookup_run_bpf(net, udptable, skb, 242 saddr, sport, daddr, hnum); 243 if (sk) { 244 result = sk; 245 goto done; 246 } 247 } 248 249 /* Got non-wildcard socket or error on first lookup */ 250 if (result) 251 goto done; 252 253 /* Lookup wildcard sockets */ 254 hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum); 255 slot2 = hash2 & udptable->mask; 256 hslot2 = &udptable->hash2[slot2]; 257 258 result = udp6_lib_lookup2(net, saddr, sport, 259 &in6addr_any, hnum, dif, sdif, 260 hslot2, skb); 261 done: 262 if (IS_ERR(result)) 263 return NULL; 264 return result; 265 } 266 EXPORT_SYMBOL_GPL(__udp6_lib_lookup); 267 268 static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb, 269 __be16 sport, __be16 dport, 270 struct udp_table *udptable) 271 { 272 const struct ipv6hdr *iph = ipv6_hdr(skb); 273 274 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, 275 &iph->daddr, dport, inet6_iif(skb), 276 inet6_sdif(skb), udptable, skb); 277 } 278 279 struct sock *udp6_lib_lookup_skb(struct sk_buff *skb, 280 __be16 sport, __be16 dport) 281 { 282 const struct ipv6hdr *iph = ipv6_hdr(skb); 283 284 return __udp6_lib_lookup(dev_net(skb->dev), &iph->saddr, sport, 285 &iph->daddr, dport, inet6_iif(skb), 286 inet6_sdif(skb), &udp_table, NULL); 287 } 288 EXPORT_SYMBOL_GPL(udp6_lib_lookup_skb); 289 290 /* Must be called under rcu_read_lock(). 291 * Does increment socket refcount. 292 */ 293 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6) 294 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, 295 const struct in6_addr *daddr, __be16 dport, int dif) 296 { 297 struct sock *sk; 298 299 sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport, 300 dif, 0, &udp_table, NULL); 301 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) 302 sk = NULL; 303 return sk; 304 } 305 EXPORT_SYMBOL_GPL(udp6_lib_lookup); 306 #endif 307 308 /* do not use the scratch area len for jumbogram: their length execeeds the 309 * scratch area space; note that the IP6CB flags is still in the first 310 * cacheline, so checking for jumbograms is cheap 311 */ 312 static int udp6_skb_len(struct sk_buff *skb) 313 { 314 return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb); 315 } 316 317 /* 318 * This should be easy, if there is something there we 319 * return it, otherwise we block. 320 */ 321 322 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 323 int noblock, int flags, int *addr_len) 324 { 325 struct ipv6_pinfo *np = inet6_sk(sk); 326 struct inet_sock *inet = inet_sk(sk); 327 struct sk_buff *skb; 328 unsigned int ulen, copied; 329 int off, err, peeking = flags & MSG_PEEK; 330 int is_udplite = IS_UDPLITE(sk); 331 struct udp_mib __percpu *mib; 332 bool checksum_valid = false; 333 int is_udp4; 334 335 if (flags & MSG_ERRQUEUE) 336 return ipv6_recv_error(sk, msg, len, addr_len); 337 338 if (np->rxpmtu && np->rxopt.bits.rxpmtu) 339 return ipv6_recv_rxpmtu(sk, msg, len, addr_len); 340 341 try_again: 342 off = sk_peek_offset(sk, flags); 343 skb = __skb_recv_udp(sk, flags, noblock, &off, &err); 344 if (!skb) 345 return err; 346 347 ulen = udp6_skb_len(skb); 348 copied = len; 349 if (copied > ulen - off) 350 copied = ulen - off; 351 else if (copied < ulen) 352 msg->msg_flags |= MSG_TRUNC; 353 354 is_udp4 = (skb->protocol == htons(ETH_P_IP)); 355 mib = __UDPX_MIB(sk, is_udp4); 356 357 /* 358 * If checksum is needed at all, try to do it while copying the 359 * data. If the data is truncated, or if we only want a partial 360 * coverage checksum (UDP-Lite), do it before the copy. 361 */ 362 363 if (copied < ulen || peeking || 364 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { 365 checksum_valid = udp_skb_csum_unnecessary(skb) || 366 !__udp_lib_checksum_complete(skb); 367 if (!checksum_valid) 368 goto csum_copy_err; 369 } 370 371 if (checksum_valid || udp_skb_csum_unnecessary(skb)) { 372 if (udp_skb_is_linear(skb)) 373 err = copy_linear_skb(skb, copied, off, &msg->msg_iter); 374 else 375 err = skb_copy_datagram_msg(skb, off, msg, copied); 376 } else { 377 err = skb_copy_and_csum_datagram_msg(skb, off, msg); 378 if (err == -EINVAL) 379 goto csum_copy_err; 380 } 381 if (unlikely(err)) { 382 if (!peeking) { 383 atomic_inc(&sk->sk_drops); 384 SNMP_INC_STATS(mib, UDP_MIB_INERRORS); 385 } 386 kfree_skb(skb); 387 return err; 388 } 389 if (!peeking) 390 SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS); 391 392 sock_recv_ts_and_drops(msg, sk, skb); 393 394 /* Copy the address. */ 395 if (msg->msg_name) { 396 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 397 sin6->sin6_family = AF_INET6; 398 sin6->sin6_port = udp_hdr(skb)->source; 399 sin6->sin6_flowinfo = 0; 400 401 if (is_udp4) { 402 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, 403 &sin6->sin6_addr); 404 sin6->sin6_scope_id = 0; 405 } else { 406 sin6->sin6_addr = ipv6_hdr(skb)->saddr; 407 sin6->sin6_scope_id = 408 ipv6_iface_scope_id(&sin6->sin6_addr, 409 inet6_iif(skb)); 410 } 411 *addr_len = sizeof(*sin6); 412 413 if (cgroup_bpf_enabled) 414 BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, 415 (struct sockaddr *)sin6); 416 } 417 418 if (udp_sk(sk)->gro_enabled) 419 udp_cmsg_recv(msg, sk, skb); 420 421 if (np->rxopt.all) 422 ip6_datagram_recv_common_ctl(sk, msg, skb); 423 424 if (is_udp4) { 425 if (inet->cmsg_flags) 426 ip_cmsg_recv_offset(msg, sk, skb, 427 sizeof(struct udphdr), off); 428 } else { 429 if (np->rxopt.all) 430 ip6_datagram_recv_specific_ctl(sk, msg, skb); 431 } 432 433 err = copied; 434 if (flags & MSG_TRUNC) 435 err = ulen; 436 437 skb_consume_udp(sk, skb, peeking ? -err : err); 438 return err; 439 440 csum_copy_err: 441 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, 442 udp_skb_destructor)) { 443 SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS); 444 SNMP_INC_STATS(mib, UDP_MIB_INERRORS); 445 } 446 kfree_skb(skb); 447 448 /* starting over for a new packet, but check if we need to yield */ 449 cond_resched(); 450 msg->msg_flags &= ~MSG_TRUNC; 451 goto try_again; 452 } 453 454 DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key); 455 void udpv6_encap_enable(void) 456 { 457 static_branch_inc(&udpv6_encap_needed_key); 458 } 459 EXPORT_SYMBOL(udpv6_encap_enable); 460 461 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go 462 * through error handlers in encapsulations looking for a match. 463 */ 464 static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb, 465 struct inet6_skb_parm *opt, 466 u8 type, u8 code, int offset, __be32 info) 467 { 468 int i; 469 470 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) { 471 int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt, 472 u8 type, u8 code, int offset, __be32 info); 473 const struct ip6_tnl_encap_ops *encap; 474 475 encap = rcu_dereference(ip6tun_encaps[i]); 476 if (!encap) 477 continue; 478 handler = encap->err_handler; 479 if (handler && !handler(skb, opt, type, code, offset, info)) 480 return 0; 481 } 482 483 return -ENOENT; 484 } 485 486 /* Try to match ICMP errors to UDP tunnels by looking up a socket without 487 * reversing source and destination port: this will match tunnels that force the 488 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that 489 * lwtunnels might actually break this assumption by being configured with 490 * different destination ports on endpoints, in this case we won't be able to 491 * trace ICMP messages back to them. 492 * 493 * If this doesn't match any socket, probe tunnels with arbitrary destination 494 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port 495 * we've sent packets to won't necessarily match the local destination port. 496 * 497 * Then ask the tunnel implementation to match the error against a valid 498 * association. 499 * 500 * Return an error if we can't find a match, the socket if we need further 501 * processing, zero otherwise. 502 */ 503 static struct sock *__udp6_lib_err_encap(struct net *net, 504 const struct ipv6hdr *hdr, int offset, 505 struct udphdr *uh, 506 struct udp_table *udptable, 507 struct sk_buff *skb, 508 struct inet6_skb_parm *opt, 509 u8 type, u8 code, __be32 info) 510 { 511 int network_offset, transport_offset; 512 struct sock *sk; 513 514 network_offset = skb_network_offset(skb); 515 transport_offset = skb_transport_offset(skb); 516 517 /* Network header needs to point to the outer IPv6 header inside ICMP */ 518 skb_reset_network_header(skb); 519 520 /* Transport header needs to point to the UDP header */ 521 skb_set_transport_header(skb, offset); 522 523 sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source, 524 &hdr->saddr, uh->dest, 525 inet6_iif(skb), 0, udptable, skb); 526 if (sk) { 527 int (*lookup)(struct sock *sk, struct sk_buff *skb); 528 struct udp_sock *up = udp_sk(sk); 529 530 lookup = READ_ONCE(up->encap_err_lookup); 531 if (!lookup || lookup(sk, skb)) 532 sk = NULL; 533 } 534 535 if (!sk) { 536 sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code, 537 offset, info)); 538 } 539 540 skb_set_transport_header(skb, transport_offset); 541 skb_set_network_header(skb, network_offset); 542 543 return sk; 544 } 545 546 int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 547 u8 type, u8 code, int offset, __be32 info, 548 struct udp_table *udptable) 549 { 550 struct ipv6_pinfo *np; 551 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; 552 const struct in6_addr *saddr = &hdr->saddr; 553 const struct in6_addr *daddr = &hdr->daddr; 554 struct udphdr *uh = (struct udphdr *)(skb->data+offset); 555 bool tunnel = false; 556 struct sock *sk; 557 int harderr; 558 int err; 559 struct net *net = dev_net(skb->dev); 560 561 sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source, 562 inet6_iif(skb), inet6_sdif(skb), udptable, NULL); 563 if (!sk) { 564 /* No socket for error: try tunnels before discarding */ 565 sk = ERR_PTR(-ENOENT); 566 if (static_branch_unlikely(&udpv6_encap_needed_key)) { 567 sk = __udp6_lib_err_encap(net, hdr, offset, uh, 568 udptable, skb, 569 opt, type, code, info); 570 if (!sk) 571 return 0; 572 } 573 574 if (IS_ERR(sk)) { 575 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), 576 ICMP6_MIB_INERRORS); 577 return PTR_ERR(sk); 578 } 579 580 tunnel = true; 581 } 582 583 harderr = icmpv6_err_convert(type, code, &err); 584 np = inet6_sk(sk); 585 586 if (type == ICMPV6_PKT_TOOBIG) { 587 if (!ip6_sk_accept_pmtu(sk)) 588 goto out; 589 ip6_sk_update_pmtu(skb, sk, info); 590 if (np->pmtudisc != IPV6_PMTUDISC_DONT) 591 harderr = 1; 592 } 593 if (type == NDISC_REDIRECT) { 594 if (tunnel) { 595 ip6_redirect(skb, sock_net(sk), inet6_iif(skb), 596 sk->sk_mark, sk->sk_uid); 597 } else { 598 ip6_sk_redirect(skb, sk); 599 } 600 goto out; 601 } 602 603 /* Tunnels don't have an application socket: don't pass errors back */ 604 if (tunnel) 605 goto out; 606 607 if (!np->recverr) { 608 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 609 goto out; 610 } else { 611 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1)); 612 } 613 614 sk->sk_err = err; 615 sk->sk_error_report(sk); 616 out: 617 return 0; 618 } 619 620 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 621 { 622 int rc; 623 624 if (!ipv6_addr_any(&sk->sk_v6_daddr)) { 625 sock_rps_save_rxhash(sk, skb); 626 sk_mark_napi_id(sk, skb); 627 sk_incoming_cpu_update(sk); 628 } else { 629 sk_mark_napi_id_once(sk, skb); 630 } 631 632 rc = __udp_enqueue_schedule_skb(sk, skb); 633 if (rc < 0) { 634 int is_udplite = IS_UDPLITE(sk); 635 636 /* Note that an ENOMEM error is charged twice */ 637 if (rc == -ENOMEM) 638 UDP6_INC_STATS(sock_net(sk), 639 UDP_MIB_RCVBUFERRORS, is_udplite); 640 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 641 kfree_skb(skb); 642 return -1; 643 } 644 645 return 0; 646 } 647 648 static __inline__ int udpv6_err(struct sk_buff *skb, 649 struct inet6_skb_parm *opt, u8 type, 650 u8 code, int offset, __be32 info) 651 { 652 return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table); 653 } 654 655 static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb) 656 { 657 struct udp_sock *up = udp_sk(sk); 658 int is_udplite = IS_UDPLITE(sk); 659 660 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 661 goto drop; 662 663 if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) { 664 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 665 666 /* 667 * This is an encapsulation socket so pass the skb to 668 * the socket's udp_encap_rcv() hook. Otherwise, just 669 * fall through and pass this up the UDP socket. 670 * up->encap_rcv() returns the following value: 671 * =0 if skb was successfully passed to the encap 672 * handler or was discarded by it. 673 * >0 if skb should be passed on to UDP. 674 * <0 if skb should be resubmitted as proto -N 675 */ 676 677 /* if we're overly short, let UDP handle it */ 678 encap_rcv = READ_ONCE(up->encap_rcv); 679 if (encap_rcv) { 680 int ret; 681 682 /* Verify checksum before giving to encap */ 683 if (udp_lib_checksum_complete(skb)) 684 goto csum_error; 685 686 ret = encap_rcv(sk, skb); 687 if (ret <= 0) { 688 __UDP_INC_STATS(sock_net(sk), 689 UDP_MIB_INDATAGRAMS, 690 is_udplite); 691 return -ret; 692 } 693 } 694 695 /* FALLTHROUGH -- it's a UDP Packet */ 696 } 697 698 /* 699 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c). 700 */ 701 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 702 703 if (up->pcrlen == 0) { /* full coverage was set */ 704 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n", 705 UDP_SKB_CB(skb)->cscov, skb->len); 706 goto drop; 707 } 708 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 709 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n", 710 UDP_SKB_CB(skb)->cscov, up->pcrlen); 711 goto drop; 712 } 713 } 714 715 prefetch(&sk->sk_rmem_alloc); 716 if (rcu_access_pointer(sk->sk_filter) && 717 udp_lib_checksum_complete(skb)) 718 goto csum_error; 719 720 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) 721 goto drop; 722 723 udp_csum_pull_header(skb); 724 725 skb_dst_drop(skb); 726 727 return __udpv6_queue_rcv_skb(sk, skb); 728 729 csum_error: 730 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 731 drop: 732 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 733 atomic_inc(&sk->sk_drops); 734 kfree_skb(skb); 735 return -1; 736 } 737 738 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 739 { 740 struct sk_buff *next, *segs; 741 int ret; 742 743 if (likely(!udp_unexpected_gso(sk, skb))) 744 return udpv6_queue_rcv_one_skb(sk, skb); 745 746 __skb_push(skb, -skb_mac_offset(skb)); 747 segs = udp_rcv_segment(sk, skb, false); 748 skb_list_walk_safe(segs, skb, next) { 749 __skb_pull(skb, skb_transport_offset(skb)); 750 751 ret = udpv6_queue_rcv_one_skb(sk, skb); 752 if (ret > 0) 753 ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret, 754 true); 755 } 756 return 0; 757 } 758 759 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk, 760 __be16 loc_port, const struct in6_addr *loc_addr, 761 __be16 rmt_port, const struct in6_addr *rmt_addr, 762 int dif, int sdif, unsigned short hnum) 763 { 764 struct inet_sock *inet = inet_sk(sk); 765 766 if (!net_eq(sock_net(sk), net)) 767 return false; 768 769 if (udp_sk(sk)->udp_port_hash != hnum || 770 sk->sk_family != PF_INET6 || 771 (inet->inet_dport && inet->inet_dport != rmt_port) || 772 (!ipv6_addr_any(&sk->sk_v6_daddr) && 773 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) || 774 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif) || 775 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 776 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr))) 777 return false; 778 if (!inet6_mc_check(sk, loc_addr, rmt_addr)) 779 return false; 780 return true; 781 } 782 783 static void udp6_csum_zero_error(struct sk_buff *skb) 784 { 785 /* RFC 2460 section 8.1 says that we SHOULD log 786 * this error. Well, it is reasonable. 787 */ 788 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n", 789 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source), 790 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest)); 791 } 792 793 /* 794 * Note: called only from the BH handler context, 795 * so we don't need to lock the hashes. 796 */ 797 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 798 const struct in6_addr *saddr, const struct in6_addr *daddr, 799 struct udp_table *udptable, int proto) 800 { 801 struct sock *sk, *first = NULL; 802 const struct udphdr *uh = udp_hdr(skb); 803 unsigned short hnum = ntohs(uh->dest); 804 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); 805 unsigned int offset = offsetof(typeof(*sk), sk_node); 806 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); 807 int dif = inet6_iif(skb); 808 int sdif = inet6_sdif(skb); 809 struct hlist_node *node; 810 struct sk_buff *nskb; 811 812 if (use_hash2) { 813 hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) & 814 udptable->mask; 815 hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask; 816 start_lookup: 817 hslot = &udptable->hash2[hash2]; 818 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); 819 } 820 821 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { 822 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr, 823 uh->source, saddr, dif, sdif, 824 hnum)) 825 continue; 826 /* If zero checksum and no_check is not on for 827 * the socket then skip it. 828 */ 829 if (!uh->check && !udp_sk(sk)->no_check6_rx) 830 continue; 831 if (!first) { 832 first = sk; 833 continue; 834 } 835 nskb = skb_clone(skb, GFP_ATOMIC); 836 if (unlikely(!nskb)) { 837 atomic_inc(&sk->sk_drops); 838 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS, 839 IS_UDPLITE(sk)); 840 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, 841 IS_UDPLITE(sk)); 842 continue; 843 } 844 845 if (udpv6_queue_rcv_skb(sk, nskb) > 0) 846 consume_skb(nskb); 847 } 848 849 /* Also lookup *:port if we are using hash2 and haven't done so yet. */ 850 if (use_hash2 && hash2 != hash2_any) { 851 hash2 = hash2_any; 852 goto start_lookup; 853 } 854 855 if (first) { 856 if (udpv6_queue_rcv_skb(first, skb) > 0) 857 consume_skb(skb); 858 } else { 859 kfree_skb(skb); 860 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI, 861 proto == IPPROTO_UDPLITE); 862 } 863 return 0; 864 } 865 866 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) 867 { 868 if (udp_sk_rx_dst_set(sk, dst)) { 869 const struct rt6_info *rt = (const struct rt6_info *)dst; 870 871 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt); 872 } 873 } 874 875 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and 876 * return code conversion for ip layer consumption 877 */ 878 static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb, 879 struct udphdr *uh) 880 { 881 int ret; 882 883 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) 884 skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo); 885 886 ret = udpv6_queue_rcv_skb(sk, skb); 887 888 /* a return value > 0 means to resubmit the input */ 889 if (ret > 0) 890 return ret; 891 return 0; 892 } 893 894 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 895 int proto) 896 { 897 const struct in6_addr *saddr, *daddr; 898 struct net *net = dev_net(skb->dev); 899 struct udphdr *uh; 900 struct sock *sk; 901 bool refcounted; 902 u32 ulen = 0; 903 904 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 905 goto discard; 906 907 saddr = &ipv6_hdr(skb)->saddr; 908 daddr = &ipv6_hdr(skb)->daddr; 909 uh = udp_hdr(skb); 910 911 ulen = ntohs(uh->len); 912 if (ulen > skb->len) 913 goto short_packet; 914 915 if (proto == IPPROTO_UDP) { 916 /* UDP validates ulen. */ 917 918 /* Check for jumbo payload */ 919 if (ulen == 0) 920 ulen = skb->len; 921 922 if (ulen < sizeof(*uh)) 923 goto short_packet; 924 925 if (ulen < skb->len) { 926 if (pskb_trim_rcsum(skb, ulen)) 927 goto short_packet; 928 saddr = &ipv6_hdr(skb)->saddr; 929 daddr = &ipv6_hdr(skb)->daddr; 930 uh = udp_hdr(skb); 931 } 932 } 933 934 if (udp6_csum_init(skb, uh, proto)) 935 goto csum_error; 936 937 /* Check if the socket is already available, e.g. due to early demux */ 938 sk = skb_steal_sock(skb, &refcounted); 939 if (sk) { 940 struct dst_entry *dst = skb_dst(skb); 941 int ret; 942 943 if (unlikely(sk->sk_rx_dst != dst)) 944 udp6_sk_rx_dst_set(sk, dst); 945 946 if (!uh->check && !udp_sk(sk)->no_check6_rx) { 947 if (refcounted) 948 sock_put(sk); 949 goto report_csum_error; 950 } 951 952 ret = udp6_unicast_rcv_skb(sk, skb, uh); 953 if (refcounted) 954 sock_put(sk); 955 return ret; 956 } 957 958 /* 959 * Multicast receive code 960 */ 961 if (ipv6_addr_is_multicast(daddr)) 962 return __udp6_lib_mcast_deliver(net, skb, 963 saddr, daddr, udptable, proto); 964 965 /* Unicast */ 966 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 967 if (sk) { 968 if (!uh->check && !udp_sk(sk)->no_check6_rx) 969 goto report_csum_error; 970 return udp6_unicast_rcv_skb(sk, skb, uh); 971 } 972 973 if (!uh->check) 974 goto report_csum_error; 975 976 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 977 goto discard; 978 979 if (udp_lib_checksum_complete(skb)) 980 goto csum_error; 981 982 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 983 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 984 985 kfree_skb(skb); 986 return 0; 987 988 short_packet: 989 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n", 990 proto == IPPROTO_UDPLITE ? "-Lite" : "", 991 saddr, ntohs(uh->source), 992 ulen, skb->len, 993 daddr, ntohs(uh->dest)); 994 goto discard; 995 996 report_csum_error: 997 udp6_csum_zero_error(skb); 998 csum_error: 999 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 1000 discard: 1001 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 1002 kfree_skb(skb); 1003 return 0; 1004 } 1005 1006 1007 static struct sock *__udp6_lib_demux_lookup(struct net *net, 1008 __be16 loc_port, const struct in6_addr *loc_addr, 1009 __be16 rmt_port, const struct in6_addr *rmt_addr, 1010 int dif, int sdif) 1011 { 1012 unsigned short hnum = ntohs(loc_port); 1013 unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum); 1014 unsigned int slot2 = hash2 & udp_table.mask; 1015 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 1016 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 1017 struct sock *sk; 1018 1019 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 1020 if (sk->sk_state == TCP_ESTABLISHED && 1021 INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif)) 1022 return sk; 1023 /* Only check first socket in chain */ 1024 break; 1025 } 1026 return NULL; 1027 } 1028 1029 INDIRECT_CALLABLE_SCOPE void udp_v6_early_demux(struct sk_buff *skb) 1030 { 1031 struct net *net = dev_net(skb->dev); 1032 const struct udphdr *uh; 1033 struct sock *sk; 1034 struct dst_entry *dst; 1035 int dif = skb->dev->ifindex; 1036 int sdif = inet6_sdif(skb); 1037 1038 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 1039 sizeof(struct udphdr))) 1040 return; 1041 1042 uh = udp_hdr(skb); 1043 1044 if (skb->pkt_type == PACKET_HOST) 1045 sk = __udp6_lib_demux_lookup(net, uh->dest, 1046 &ipv6_hdr(skb)->daddr, 1047 uh->source, &ipv6_hdr(skb)->saddr, 1048 dif, sdif); 1049 else 1050 return; 1051 1052 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) 1053 return; 1054 1055 skb->sk = sk; 1056 skb->destructor = sock_efree; 1057 dst = READ_ONCE(sk->sk_rx_dst); 1058 1059 if (dst) 1060 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie); 1061 if (dst) { 1062 /* set noref for now. 1063 * any place which wants to hold dst has to call 1064 * dst_hold_safe() 1065 */ 1066 skb_dst_set_noref(skb, dst); 1067 } 1068 } 1069 1070 INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb) 1071 { 1072 return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP); 1073 } 1074 1075 /* 1076 * Throw away all pending data and cancel the corking. Socket is locked. 1077 */ 1078 static void udp_v6_flush_pending_frames(struct sock *sk) 1079 { 1080 struct udp_sock *up = udp_sk(sk); 1081 1082 if (up->pending == AF_INET) 1083 udp_flush_pending_frames(sk); 1084 else if (up->pending) { 1085 up->len = 0; 1086 up->pending = 0; 1087 ip6_flush_pending_frames(sk); 1088 } 1089 } 1090 1091 static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr, 1092 int addr_len) 1093 { 1094 if (addr_len < offsetofend(struct sockaddr, sa_family)) 1095 return -EINVAL; 1096 /* The following checks are replicated from __ip6_datagram_connect() 1097 * and intended to prevent BPF program called below from accessing 1098 * bytes that are out of the bound specified by user in addr_len. 1099 */ 1100 if (uaddr->sa_family == AF_INET) { 1101 if (__ipv6_only_sock(sk)) 1102 return -EAFNOSUPPORT; 1103 return udp_pre_connect(sk, uaddr, addr_len); 1104 } 1105 1106 if (addr_len < SIN6_LEN_RFC2133) 1107 return -EINVAL; 1108 1109 return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr); 1110 } 1111 1112 /** 1113 * udp6_hwcsum_outgoing - handle outgoing HW checksumming 1114 * @sk: socket we are sending on 1115 * @skb: sk_buff containing the filled-in UDP header 1116 * (checksum field must be zeroed out) 1117 * @saddr: source address 1118 * @daddr: destination address 1119 * @len: length of packet 1120 */ 1121 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, 1122 const struct in6_addr *saddr, 1123 const struct in6_addr *daddr, int len) 1124 { 1125 unsigned int offset; 1126 struct udphdr *uh = udp_hdr(skb); 1127 struct sk_buff *frags = skb_shinfo(skb)->frag_list; 1128 __wsum csum = 0; 1129 1130 if (!frags) { 1131 /* Only one fragment on the socket. */ 1132 skb->csum_start = skb_transport_header(skb) - skb->head; 1133 skb->csum_offset = offsetof(struct udphdr, check); 1134 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0); 1135 } else { 1136 /* 1137 * HW-checksum won't work as there are two or more 1138 * fragments on the socket so that all csums of sk_buffs 1139 * should be together 1140 */ 1141 offset = skb_transport_offset(skb); 1142 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); 1143 csum = skb->csum; 1144 1145 skb->ip_summed = CHECKSUM_NONE; 1146 1147 do { 1148 csum = csum_add(csum, frags->csum); 1149 } while ((frags = frags->next)); 1150 1151 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 1152 csum); 1153 if (uh->check == 0) 1154 uh->check = CSUM_MANGLED_0; 1155 } 1156 } 1157 1158 /* 1159 * Sending 1160 */ 1161 1162 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6, 1163 struct inet_cork *cork) 1164 { 1165 struct sock *sk = skb->sk; 1166 struct udphdr *uh; 1167 int err = 0; 1168 int is_udplite = IS_UDPLITE(sk); 1169 __wsum csum = 0; 1170 int offset = skb_transport_offset(skb); 1171 int len = skb->len - offset; 1172 int datalen = len - sizeof(*uh); 1173 1174 /* 1175 * Create a UDP header 1176 */ 1177 uh = udp_hdr(skb); 1178 uh->source = fl6->fl6_sport; 1179 uh->dest = fl6->fl6_dport; 1180 uh->len = htons(len); 1181 uh->check = 0; 1182 1183 if (cork->gso_size) { 1184 const int hlen = skb_network_header_len(skb) + 1185 sizeof(struct udphdr); 1186 1187 if (hlen + cork->gso_size > cork->fragsize) { 1188 kfree_skb(skb); 1189 return -EINVAL; 1190 } 1191 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) { 1192 kfree_skb(skb); 1193 return -EINVAL; 1194 } 1195 if (udp_sk(sk)->no_check6_tx) { 1196 kfree_skb(skb); 1197 return -EINVAL; 1198 } 1199 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite || 1200 dst_xfrm(skb_dst(skb))) { 1201 kfree_skb(skb); 1202 return -EIO; 1203 } 1204 1205 if (datalen > cork->gso_size) { 1206 skb_shinfo(skb)->gso_size = cork->gso_size; 1207 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; 1208 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen, 1209 cork->gso_size); 1210 } 1211 goto csum_partial; 1212 } 1213 1214 if (is_udplite) 1215 csum = udplite_csum(skb); 1216 else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */ 1217 skb->ip_summed = CHECKSUM_NONE; 1218 goto send; 1219 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 1220 csum_partial: 1221 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len); 1222 goto send; 1223 } else 1224 csum = udp_csum(skb); 1225 1226 /* add protocol-dependent pseudo-header */ 1227 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr, 1228 len, fl6->flowi6_proto, csum); 1229 if (uh->check == 0) 1230 uh->check = CSUM_MANGLED_0; 1231 1232 send: 1233 err = ip6_send_skb(skb); 1234 if (err) { 1235 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) { 1236 UDP6_INC_STATS(sock_net(sk), 1237 UDP_MIB_SNDBUFERRORS, is_udplite); 1238 err = 0; 1239 } 1240 } else { 1241 UDP6_INC_STATS(sock_net(sk), 1242 UDP_MIB_OUTDATAGRAMS, is_udplite); 1243 } 1244 return err; 1245 } 1246 1247 static int udp_v6_push_pending_frames(struct sock *sk) 1248 { 1249 struct sk_buff *skb; 1250 struct udp_sock *up = udp_sk(sk); 1251 struct flowi6 fl6; 1252 int err = 0; 1253 1254 if (up->pending == AF_INET) 1255 return udp_push_pending_frames(sk); 1256 1257 /* ip6_finish_skb will release the cork, so make a copy of 1258 * fl6 here. 1259 */ 1260 fl6 = inet_sk(sk)->cork.fl.u.ip6; 1261 1262 skb = ip6_finish_skb(sk); 1263 if (!skb) 1264 goto out; 1265 1266 err = udp_v6_send_skb(skb, &fl6, &inet_sk(sk)->cork.base); 1267 1268 out: 1269 up->len = 0; 1270 up->pending = 0; 1271 return err; 1272 } 1273 1274 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 1275 { 1276 struct ipv6_txoptions opt_space; 1277 struct udp_sock *up = udp_sk(sk); 1278 struct inet_sock *inet = inet_sk(sk); 1279 struct ipv6_pinfo *np = inet6_sk(sk); 1280 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 1281 struct in6_addr *daddr, *final_p, final; 1282 struct ipv6_txoptions *opt = NULL; 1283 struct ipv6_txoptions *opt_to_free = NULL; 1284 struct ip6_flowlabel *flowlabel = NULL; 1285 struct flowi6 fl6; 1286 struct dst_entry *dst; 1287 struct ipcm6_cookie ipc6; 1288 int addr_len = msg->msg_namelen; 1289 bool connected = false; 1290 int ulen = len; 1291 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 1292 int err; 1293 int is_udplite = IS_UDPLITE(sk); 1294 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 1295 1296 ipcm6_init(&ipc6); 1297 ipc6.gso_size = up->gso_size; 1298 ipc6.sockc.tsflags = sk->sk_tsflags; 1299 ipc6.sockc.mark = sk->sk_mark; 1300 1301 /* destination address check */ 1302 if (sin6) { 1303 if (addr_len < offsetof(struct sockaddr, sa_data)) 1304 return -EINVAL; 1305 1306 switch (sin6->sin6_family) { 1307 case AF_INET6: 1308 if (addr_len < SIN6_LEN_RFC2133) 1309 return -EINVAL; 1310 daddr = &sin6->sin6_addr; 1311 if (ipv6_addr_any(daddr) && 1312 ipv6_addr_v4mapped(&np->saddr)) 1313 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), 1314 daddr); 1315 break; 1316 case AF_INET: 1317 goto do_udp_sendmsg; 1318 case AF_UNSPEC: 1319 msg->msg_name = sin6 = NULL; 1320 msg->msg_namelen = addr_len = 0; 1321 daddr = NULL; 1322 break; 1323 default: 1324 return -EINVAL; 1325 } 1326 } else if (!up->pending) { 1327 if (sk->sk_state != TCP_ESTABLISHED) 1328 return -EDESTADDRREQ; 1329 daddr = &sk->sk_v6_daddr; 1330 } else 1331 daddr = NULL; 1332 1333 if (daddr) { 1334 if (ipv6_addr_v4mapped(daddr)) { 1335 struct sockaddr_in sin; 1336 sin.sin_family = AF_INET; 1337 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport; 1338 sin.sin_addr.s_addr = daddr->s6_addr32[3]; 1339 msg->msg_name = &sin; 1340 msg->msg_namelen = sizeof(sin); 1341 do_udp_sendmsg: 1342 if (__ipv6_only_sock(sk)) 1343 return -ENETUNREACH; 1344 return udp_sendmsg(sk, msg, len); 1345 } 1346 } 1347 1348 if (up->pending == AF_INET) 1349 return udp_sendmsg(sk, msg, len); 1350 1351 /* Rough check on arithmetic overflow, 1352 better check is made in ip6_append_data(). 1353 */ 1354 if (len > INT_MAX - sizeof(struct udphdr)) 1355 return -EMSGSIZE; 1356 1357 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 1358 if (up->pending) { 1359 /* 1360 * There are pending frames. 1361 * The socket lock must be held while it's corked. 1362 */ 1363 lock_sock(sk); 1364 if (likely(up->pending)) { 1365 if (unlikely(up->pending != AF_INET6)) { 1366 release_sock(sk); 1367 return -EAFNOSUPPORT; 1368 } 1369 dst = NULL; 1370 goto do_append_data; 1371 } 1372 release_sock(sk); 1373 } 1374 ulen += sizeof(struct udphdr); 1375 1376 memset(&fl6, 0, sizeof(fl6)); 1377 1378 if (sin6) { 1379 if (sin6->sin6_port == 0) 1380 return -EINVAL; 1381 1382 fl6.fl6_dport = sin6->sin6_port; 1383 daddr = &sin6->sin6_addr; 1384 1385 if (np->sndflow) { 1386 fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK; 1387 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 1388 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 1389 if (IS_ERR(flowlabel)) 1390 return -EINVAL; 1391 } 1392 } 1393 1394 /* 1395 * Otherwise it will be difficult to maintain 1396 * sk->sk_dst_cache. 1397 */ 1398 if (sk->sk_state == TCP_ESTABLISHED && 1399 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 1400 daddr = &sk->sk_v6_daddr; 1401 1402 if (addr_len >= sizeof(struct sockaddr_in6) && 1403 sin6->sin6_scope_id && 1404 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr))) 1405 fl6.flowi6_oif = sin6->sin6_scope_id; 1406 } else { 1407 if (sk->sk_state != TCP_ESTABLISHED) 1408 return -EDESTADDRREQ; 1409 1410 fl6.fl6_dport = inet->inet_dport; 1411 daddr = &sk->sk_v6_daddr; 1412 fl6.flowlabel = np->flow_label; 1413 connected = true; 1414 } 1415 1416 if (!fl6.flowi6_oif) 1417 fl6.flowi6_oif = sk->sk_bound_dev_if; 1418 1419 if (!fl6.flowi6_oif) 1420 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex; 1421 1422 fl6.flowi6_mark = ipc6.sockc.mark; 1423 fl6.flowi6_uid = sk->sk_uid; 1424 1425 if (msg->msg_controllen) { 1426 opt = &opt_space; 1427 memset(opt, 0, sizeof(struct ipv6_txoptions)); 1428 opt->tot_len = sizeof(*opt); 1429 ipc6.opt = opt; 1430 1431 err = udp_cmsg_send(sk, msg, &ipc6.gso_size); 1432 if (err > 0) 1433 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, 1434 &ipc6); 1435 if (err < 0) { 1436 fl6_sock_release(flowlabel); 1437 return err; 1438 } 1439 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) { 1440 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 1441 if (IS_ERR(flowlabel)) 1442 return -EINVAL; 1443 } 1444 if (!(opt->opt_nflen|opt->opt_flen)) 1445 opt = NULL; 1446 connected = false; 1447 } 1448 if (!opt) { 1449 opt = txopt_get(np); 1450 opt_to_free = opt; 1451 } 1452 if (flowlabel) 1453 opt = fl6_merge_options(&opt_space, flowlabel, opt); 1454 opt = ipv6_fixup_options(&opt_space, opt); 1455 ipc6.opt = opt; 1456 1457 fl6.flowi6_proto = sk->sk_protocol; 1458 fl6.daddr = *daddr; 1459 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 1460 fl6.saddr = np->saddr; 1461 fl6.fl6_sport = inet->inet_sport; 1462 1463 if (cgroup_bpf_enabled && !connected) { 1464 err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk, 1465 (struct sockaddr *)sin6, &fl6.saddr); 1466 if (err) 1467 goto out_no_dst; 1468 if (sin6) { 1469 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) { 1470 /* BPF program rewrote IPv6-only by IPv4-mapped 1471 * IPv6. It's currently unsupported. 1472 */ 1473 err = -ENOTSUPP; 1474 goto out_no_dst; 1475 } 1476 if (sin6->sin6_port == 0) { 1477 /* BPF program set invalid port. Reject it. */ 1478 err = -EINVAL; 1479 goto out_no_dst; 1480 } 1481 fl6.fl6_dport = sin6->sin6_port; 1482 fl6.daddr = sin6->sin6_addr; 1483 } 1484 } 1485 1486 if (ipv6_addr_any(&fl6.daddr)) 1487 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 1488 1489 final_p = fl6_update_dst(&fl6, opt, &final); 1490 if (final_p) 1491 connected = false; 1492 1493 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) { 1494 fl6.flowi6_oif = np->mcast_oif; 1495 connected = false; 1496 } else if (!fl6.flowi6_oif) 1497 fl6.flowi6_oif = np->ucast_oif; 1498 1499 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 1500 1501 if (ipc6.tclass < 0) 1502 ipc6.tclass = np->tclass; 1503 1504 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 1505 1506 dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected); 1507 if (IS_ERR(dst)) { 1508 err = PTR_ERR(dst); 1509 dst = NULL; 1510 goto out; 1511 } 1512 1513 if (ipc6.hlimit < 0) 1514 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 1515 1516 if (msg->msg_flags&MSG_CONFIRM) 1517 goto do_confirm; 1518 back_from_confirm: 1519 1520 /* Lockless fast path for the non-corking case */ 1521 if (!corkreq) { 1522 struct inet_cork_full cork; 1523 struct sk_buff *skb; 1524 1525 skb = ip6_make_skb(sk, getfrag, msg, ulen, 1526 sizeof(struct udphdr), &ipc6, 1527 &fl6, (struct rt6_info *)dst, 1528 msg->msg_flags, &cork); 1529 err = PTR_ERR(skb); 1530 if (!IS_ERR_OR_NULL(skb)) 1531 err = udp_v6_send_skb(skb, &fl6, &cork.base); 1532 goto out; 1533 } 1534 1535 lock_sock(sk); 1536 if (unlikely(up->pending)) { 1537 /* The socket is already corked while preparing it. */ 1538 /* ... which is an evident application bug. --ANK */ 1539 release_sock(sk); 1540 1541 net_dbg_ratelimited("udp cork app bug 2\n"); 1542 err = -EINVAL; 1543 goto out; 1544 } 1545 1546 up->pending = AF_INET6; 1547 1548 do_append_data: 1549 if (ipc6.dontfrag < 0) 1550 ipc6.dontfrag = np->dontfrag; 1551 up->len += ulen; 1552 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr), 1553 &ipc6, &fl6, (struct rt6_info *)dst, 1554 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1555 if (err) 1556 udp_v6_flush_pending_frames(sk); 1557 else if (!corkreq) 1558 err = udp_v6_push_pending_frames(sk); 1559 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1560 up->pending = 0; 1561 1562 if (err > 0) 1563 err = np->recverr ? net_xmit_errno(err) : 0; 1564 release_sock(sk); 1565 1566 out: 1567 dst_release(dst); 1568 out_no_dst: 1569 fl6_sock_release(flowlabel); 1570 txopt_put(opt_to_free); 1571 if (!err) 1572 return len; 1573 /* 1574 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1575 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1576 * we don't have a good statistic (IpOutDiscards but it can be too many 1577 * things). We could add another new stat but at least for now that 1578 * seems like overkill. 1579 */ 1580 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1581 UDP6_INC_STATS(sock_net(sk), 1582 UDP_MIB_SNDBUFERRORS, is_udplite); 1583 } 1584 return err; 1585 1586 do_confirm: 1587 if (msg->msg_flags & MSG_PROBE) 1588 dst_confirm_neigh(dst, &fl6.daddr); 1589 if (!(msg->msg_flags&MSG_PROBE) || len) 1590 goto back_from_confirm; 1591 err = 0; 1592 goto out; 1593 } 1594 1595 void udpv6_destroy_sock(struct sock *sk) 1596 { 1597 struct udp_sock *up = udp_sk(sk); 1598 lock_sock(sk); 1599 udp_v6_flush_pending_frames(sk); 1600 release_sock(sk); 1601 1602 if (static_branch_unlikely(&udpv6_encap_needed_key)) { 1603 if (up->encap_type) { 1604 void (*encap_destroy)(struct sock *sk); 1605 encap_destroy = READ_ONCE(up->encap_destroy); 1606 if (encap_destroy) 1607 encap_destroy(sk); 1608 } 1609 if (up->encap_enabled) 1610 static_branch_dec(&udpv6_encap_needed_key); 1611 } 1612 1613 inet6_destroy_sock(sk); 1614 } 1615 1616 /* 1617 * Socket option code for UDP 1618 */ 1619 int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 1620 unsigned int optlen) 1621 { 1622 if (level == SOL_UDP || level == SOL_UDPLITE) 1623 return udp_lib_setsockopt(sk, level, optname, 1624 optval, optlen, 1625 udp_v6_push_pending_frames); 1626 return ipv6_setsockopt(sk, level, optname, optval, optlen); 1627 } 1628 1629 int udpv6_getsockopt(struct sock *sk, int level, int optname, 1630 char __user *optval, int __user *optlen) 1631 { 1632 if (level == SOL_UDP || level == SOL_UDPLITE) 1633 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1634 return ipv6_getsockopt(sk, level, optname, optval, optlen); 1635 } 1636 1637 /* thinking of making this const? Don't. 1638 * early_demux can change based on sysctl. 1639 */ 1640 static struct inet6_protocol udpv6_protocol = { 1641 .early_demux = udp_v6_early_demux, 1642 .early_demux_handler = udp_v6_early_demux, 1643 .handler = udpv6_rcv, 1644 .err_handler = udpv6_err, 1645 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 1646 }; 1647 1648 /* ------------------------------------------------------------------------ */ 1649 #ifdef CONFIG_PROC_FS 1650 int udp6_seq_show(struct seq_file *seq, void *v) 1651 { 1652 if (v == SEQ_START_TOKEN) { 1653 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER); 1654 } else { 1655 int bucket = ((struct udp_iter_state *)seq->private)->bucket; 1656 struct inet_sock *inet = inet_sk(v); 1657 __u16 srcp = ntohs(inet->inet_sport); 1658 __u16 destp = ntohs(inet->inet_dport); 1659 __ip6_dgram_sock_seq_show(seq, v, srcp, destp, 1660 udp_rqueue_get(v), bucket); 1661 } 1662 return 0; 1663 } 1664 1665 const struct seq_operations udp6_seq_ops = { 1666 .start = udp_seq_start, 1667 .next = udp_seq_next, 1668 .stop = udp_seq_stop, 1669 .show = udp6_seq_show, 1670 }; 1671 EXPORT_SYMBOL(udp6_seq_ops); 1672 1673 static struct udp_seq_afinfo udp6_seq_afinfo = { 1674 .family = AF_INET6, 1675 .udp_table = &udp_table, 1676 }; 1677 1678 int __net_init udp6_proc_init(struct net *net) 1679 { 1680 if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops, 1681 sizeof(struct udp_iter_state), &udp6_seq_afinfo)) 1682 return -ENOMEM; 1683 return 0; 1684 } 1685 1686 void udp6_proc_exit(struct net *net) 1687 { 1688 remove_proc_entry("udp6", net->proc_net); 1689 } 1690 #endif /* CONFIG_PROC_FS */ 1691 1692 /* ------------------------------------------------------------------------ */ 1693 1694 struct proto udpv6_prot = { 1695 .name = "UDPv6", 1696 .owner = THIS_MODULE, 1697 .close = udp_lib_close, 1698 .pre_connect = udpv6_pre_connect, 1699 .connect = ip6_datagram_connect, 1700 .disconnect = udp_disconnect, 1701 .ioctl = udp_ioctl, 1702 .init = udp_init_sock, 1703 .destroy = udpv6_destroy_sock, 1704 .setsockopt = udpv6_setsockopt, 1705 .getsockopt = udpv6_getsockopt, 1706 .sendmsg = udpv6_sendmsg, 1707 .recvmsg = udpv6_recvmsg, 1708 .release_cb = ip6_datagram_release_cb, 1709 .hash = udp_lib_hash, 1710 .unhash = udp_lib_unhash, 1711 .rehash = udp_v6_rehash, 1712 .get_port = udp_v6_get_port, 1713 .memory_allocated = &udp_memory_allocated, 1714 .sysctl_mem = sysctl_udp_mem, 1715 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), 1716 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), 1717 .obj_size = sizeof(struct udp6_sock), 1718 .h.udp_table = &udp_table, 1719 .diag_destroy = udp_abort, 1720 }; 1721 1722 static struct inet_protosw udpv6_protosw = { 1723 .type = SOCK_DGRAM, 1724 .protocol = IPPROTO_UDP, 1725 .prot = &udpv6_prot, 1726 .ops = &inet6_dgram_ops, 1727 .flags = INET_PROTOSW_PERMANENT, 1728 }; 1729 1730 int __init udpv6_init(void) 1731 { 1732 int ret; 1733 1734 ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP); 1735 if (ret) 1736 goto out; 1737 1738 ret = inet6_register_protosw(&udpv6_protosw); 1739 if (ret) 1740 goto out_udpv6_protocol; 1741 out: 1742 return ret; 1743 1744 out_udpv6_protocol: 1745 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); 1746 goto out; 1747 } 1748 1749 void udpv6_exit(void) 1750 { 1751 inet6_unregister_protosw(&udpv6_protosw); 1752 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); 1753 } 1754