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(const 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 } 288 289 /* Must be called under rcu_read_lock(). 290 * Does increment socket refcount. 291 */ 292 #if IS_ENABLED(CONFIG_NF_TPROXY_IPV6) || IS_ENABLED(CONFIG_NF_SOCKET_IPV6) 293 struct sock *udp6_lib_lookup(struct net *net, const struct in6_addr *saddr, __be16 sport, 294 const struct in6_addr *daddr, __be16 dport, int dif) 295 { 296 struct sock *sk; 297 298 sk = __udp6_lib_lookup(net, saddr, sport, daddr, dport, 299 dif, 0, &udp_table, NULL); 300 if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) 301 sk = NULL; 302 return sk; 303 } 304 EXPORT_SYMBOL_GPL(udp6_lib_lookup); 305 #endif 306 307 /* do not use the scratch area len for jumbogram: their length execeeds the 308 * scratch area space; note that the IP6CB flags is still in the first 309 * cacheline, so checking for jumbograms is cheap 310 */ 311 static int udp6_skb_len(struct sk_buff *skb) 312 { 313 return unlikely(inet6_is_jumbogram(skb)) ? skb->len : udp_skb_len(skb); 314 } 315 316 /* 317 * This should be easy, if there is something there we 318 * return it, otherwise we block. 319 */ 320 321 int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 322 int noblock, int flags, int *addr_len) 323 { 324 struct ipv6_pinfo *np = inet6_sk(sk); 325 struct inet_sock *inet = inet_sk(sk); 326 struct sk_buff *skb; 327 unsigned int ulen, copied; 328 int off, err, peeking = flags & MSG_PEEK; 329 int is_udplite = IS_UDPLITE(sk); 330 struct udp_mib __percpu *mib; 331 bool checksum_valid = false; 332 int is_udp4; 333 334 if (flags & MSG_ERRQUEUE) 335 return ipv6_recv_error(sk, msg, len, addr_len); 336 337 if (np->rxpmtu && np->rxopt.bits.rxpmtu) 338 return ipv6_recv_rxpmtu(sk, msg, len, addr_len); 339 340 try_again: 341 off = sk_peek_offset(sk, flags); 342 skb = __skb_recv_udp(sk, flags, noblock, &off, &err); 343 if (!skb) 344 return err; 345 346 ulen = udp6_skb_len(skb); 347 copied = len; 348 if (copied > ulen - off) 349 copied = ulen - off; 350 else if (copied < ulen) 351 msg->msg_flags |= MSG_TRUNC; 352 353 is_udp4 = (skb->protocol == htons(ETH_P_IP)); 354 mib = __UDPX_MIB(sk, is_udp4); 355 356 /* 357 * If checksum is needed at all, try to do it while copying the 358 * data. If the data is truncated, or if we only want a partial 359 * coverage checksum (UDP-Lite), do it before the copy. 360 */ 361 362 if (copied < ulen || peeking || 363 (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { 364 checksum_valid = udp_skb_csum_unnecessary(skb) || 365 !__udp_lib_checksum_complete(skb); 366 if (!checksum_valid) 367 goto csum_copy_err; 368 } 369 370 if (checksum_valid || udp_skb_csum_unnecessary(skb)) { 371 if (udp_skb_is_linear(skb)) 372 err = copy_linear_skb(skb, copied, off, &msg->msg_iter); 373 else 374 err = skb_copy_datagram_msg(skb, off, msg, copied); 375 } else { 376 err = skb_copy_and_csum_datagram_msg(skb, off, msg); 377 if (err == -EINVAL) 378 goto csum_copy_err; 379 } 380 if (unlikely(err)) { 381 if (!peeking) { 382 atomic_inc(&sk->sk_drops); 383 SNMP_INC_STATS(mib, UDP_MIB_INERRORS); 384 } 385 kfree_skb(skb); 386 return err; 387 } 388 if (!peeking) 389 SNMP_INC_STATS(mib, UDP_MIB_INDATAGRAMS); 390 391 sock_recv_ts_and_drops(msg, sk, skb); 392 393 /* Copy the address. */ 394 if (msg->msg_name) { 395 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 396 sin6->sin6_family = AF_INET6; 397 sin6->sin6_port = udp_hdr(skb)->source; 398 sin6->sin6_flowinfo = 0; 399 400 if (is_udp4) { 401 ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, 402 &sin6->sin6_addr); 403 sin6->sin6_scope_id = 0; 404 } else { 405 sin6->sin6_addr = ipv6_hdr(skb)->saddr; 406 sin6->sin6_scope_id = 407 ipv6_iface_scope_id(&sin6->sin6_addr, 408 inet6_iif(skb)); 409 } 410 *addr_len = sizeof(*sin6); 411 412 BPF_CGROUP_RUN_PROG_UDP6_RECVMSG_LOCK(sk, 413 (struct sockaddr *)sin6); 414 } 415 416 if (udp_sk(sk)->gro_enabled) 417 udp_cmsg_recv(msg, sk, skb); 418 419 if (np->rxopt.all) 420 ip6_datagram_recv_common_ctl(sk, msg, skb); 421 422 if (is_udp4) { 423 if (inet->cmsg_flags) 424 ip_cmsg_recv_offset(msg, sk, skb, 425 sizeof(struct udphdr), off); 426 } else { 427 if (np->rxopt.all) 428 ip6_datagram_recv_specific_ctl(sk, msg, skb); 429 } 430 431 err = copied; 432 if (flags & MSG_TRUNC) 433 err = ulen; 434 435 skb_consume_udp(sk, skb, peeking ? -err : err); 436 return err; 437 438 csum_copy_err: 439 if (!__sk_queue_drop_skb(sk, &udp_sk(sk)->reader_queue, skb, flags, 440 udp_skb_destructor)) { 441 SNMP_INC_STATS(mib, UDP_MIB_CSUMERRORS); 442 SNMP_INC_STATS(mib, UDP_MIB_INERRORS); 443 } 444 kfree_skb(skb); 445 446 /* starting over for a new packet, but check if we need to yield */ 447 cond_resched(); 448 msg->msg_flags &= ~MSG_TRUNC; 449 goto try_again; 450 } 451 452 DEFINE_STATIC_KEY_FALSE(udpv6_encap_needed_key); 453 void udpv6_encap_enable(void) 454 { 455 static_branch_inc(&udpv6_encap_needed_key); 456 } 457 EXPORT_SYMBOL(udpv6_encap_enable); 458 459 /* Handler for tunnels with arbitrary destination ports: no socket lookup, go 460 * through error handlers in encapsulations looking for a match. 461 */ 462 static int __udp6_lib_err_encap_no_sk(struct sk_buff *skb, 463 struct inet6_skb_parm *opt, 464 u8 type, u8 code, int offset, __be32 info) 465 { 466 int i; 467 468 for (i = 0; i < MAX_IPTUN_ENCAP_OPS; i++) { 469 int (*handler)(struct sk_buff *skb, struct inet6_skb_parm *opt, 470 u8 type, u8 code, int offset, __be32 info); 471 const struct ip6_tnl_encap_ops *encap; 472 473 encap = rcu_dereference(ip6tun_encaps[i]); 474 if (!encap) 475 continue; 476 handler = encap->err_handler; 477 if (handler && !handler(skb, opt, type, code, offset, info)) 478 return 0; 479 } 480 481 return -ENOENT; 482 } 483 484 /* Try to match ICMP errors to UDP tunnels by looking up a socket without 485 * reversing source and destination port: this will match tunnels that force the 486 * same destination port on both endpoints (e.g. VXLAN, GENEVE). Note that 487 * lwtunnels might actually break this assumption by being configured with 488 * different destination ports on endpoints, in this case we won't be able to 489 * trace ICMP messages back to them. 490 * 491 * If this doesn't match any socket, probe tunnels with arbitrary destination 492 * ports (e.g. FoU, GUE): there, the receiving socket is useless, as the port 493 * we've sent packets to won't necessarily match the local destination port. 494 * 495 * Then ask the tunnel implementation to match the error against a valid 496 * association. 497 * 498 * Return an error if we can't find a match, the socket if we need further 499 * processing, zero otherwise. 500 */ 501 static struct sock *__udp6_lib_err_encap(struct net *net, 502 const struct ipv6hdr *hdr, int offset, 503 struct udphdr *uh, 504 struct udp_table *udptable, 505 struct sk_buff *skb, 506 struct inet6_skb_parm *opt, 507 u8 type, u8 code, __be32 info) 508 { 509 int network_offset, transport_offset; 510 struct sock *sk; 511 512 network_offset = skb_network_offset(skb); 513 transport_offset = skb_transport_offset(skb); 514 515 /* Network header needs to point to the outer IPv6 header inside ICMP */ 516 skb_reset_network_header(skb); 517 518 /* Transport header needs to point to the UDP header */ 519 skb_set_transport_header(skb, offset); 520 521 sk = __udp6_lib_lookup(net, &hdr->daddr, uh->source, 522 &hdr->saddr, uh->dest, 523 inet6_iif(skb), 0, udptable, skb); 524 if (sk) { 525 int (*lookup)(struct sock *sk, struct sk_buff *skb); 526 struct udp_sock *up = udp_sk(sk); 527 528 lookup = READ_ONCE(up->encap_err_lookup); 529 if (!lookup || lookup(sk, skb)) 530 sk = NULL; 531 } 532 533 if (!sk) { 534 sk = ERR_PTR(__udp6_lib_err_encap_no_sk(skb, opt, type, code, 535 offset, info)); 536 } 537 538 skb_set_transport_header(skb, transport_offset); 539 skb_set_network_header(skb, network_offset); 540 541 return sk; 542 } 543 544 int __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 545 u8 type, u8 code, int offset, __be32 info, 546 struct udp_table *udptable) 547 { 548 struct ipv6_pinfo *np; 549 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; 550 const struct in6_addr *saddr = &hdr->saddr; 551 const struct in6_addr *daddr = &hdr->daddr; 552 struct udphdr *uh = (struct udphdr *)(skb->data+offset); 553 bool tunnel = false; 554 struct sock *sk; 555 int harderr; 556 int err; 557 struct net *net = dev_net(skb->dev); 558 559 sk = __udp6_lib_lookup(net, daddr, uh->dest, saddr, uh->source, 560 inet6_iif(skb), inet6_sdif(skb), udptable, NULL); 561 if (!sk || udp_sk(sk)->encap_type) { 562 /* No socket for error: try tunnels before discarding */ 563 sk = ERR_PTR(-ENOENT); 564 if (static_branch_unlikely(&udpv6_encap_needed_key)) { 565 sk = __udp6_lib_err_encap(net, hdr, offset, uh, 566 udptable, skb, 567 opt, type, code, info); 568 if (!sk) 569 return 0; 570 } 571 572 if (IS_ERR(sk)) { 573 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), 574 ICMP6_MIB_INERRORS); 575 return PTR_ERR(sk); 576 } 577 578 tunnel = true; 579 } 580 581 harderr = icmpv6_err_convert(type, code, &err); 582 np = inet6_sk(sk); 583 584 if (type == ICMPV6_PKT_TOOBIG) { 585 if (!ip6_sk_accept_pmtu(sk)) 586 goto out; 587 ip6_sk_update_pmtu(skb, sk, info); 588 if (np->pmtudisc != IPV6_PMTUDISC_DONT) 589 harderr = 1; 590 } 591 if (type == NDISC_REDIRECT) { 592 if (tunnel) { 593 ip6_redirect(skb, sock_net(sk), inet6_iif(skb), 594 sk->sk_mark, sk->sk_uid); 595 } else { 596 ip6_sk_redirect(skb, sk); 597 } 598 goto out; 599 } 600 601 /* Tunnels don't have an application socket: don't pass errors back */ 602 if (tunnel) 603 goto out; 604 605 if (!np->recverr) { 606 if (!harderr || sk->sk_state != TCP_ESTABLISHED) 607 goto out; 608 } else { 609 ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1)); 610 } 611 612 sk->sk_err = err; 613 sk->sk_error_report(sk); 614 out: 615 return 0; 616 } 617 618 static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 619 { 620 int rc; 621 622 if (!ipv6_addr_any(&sk->sk_v6_daddr)) { 623 sock_rps_save_rxhash(sk, skb); 624 sk_mark_napi_id(sk, skb); 625 sk_incoming_cpu_update(sk); 626 } else { 627 sk_mark_napi_id_once(sk, skb); 628 } 629 630 rc = __udp_enqueue_schedule_skb(sk, skb); 631 if (rc < 0) { 632 int is_udplite = IS_UDPLITE(sk); 633 634 /* Note that an ENOMEM error is charged twice */ 635 if (rc == -ENOMEM) 636 UDP6_INC_STATS(sock_net(sk), 637 UDP_MIB_RCVBUFERRORS, is_udplite); 638 else 639 UDP6_INC_STATS(sock_net(sk), 640 UDP_MIB_MEMERRORS, is_udplite); 641 UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 642 kfree_skb(skb); 643 return -1; 644 } 645 646 return 0; 647 } 648 649 static __inline__ int udpv6_err(struct sk_buff *skb, 650 struct inet6_skb_parm *opt, u8 type, 651 u8 code, int offset, __be32 info) 652 { 653 return __udp6_lib_err(skb, opt, type, code, offset, info, &udp_table); 654 } 655 656 static int udpv6_queue_rcv_one_skb(struct sock *sk, struct sk_buff *skb) 657 { 658 struct udp_sock *up = udp_sk(sk); 659 int is_udplite = IS_UDPLITE(sk); 660 661 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 662 goto drop; 663 664 if (static_branch_unlikely(&udpv6_encap_needed_key) && up->encap_type) { 665 int (*encap_rcv)(struct sock *sk, struct sk_buff *skb); 666 667 /* 668 * This is an encapsulation socket so pass the skb to 669 * the socket's udp_encap_rcv() hook. Otherwise, just 670 * fall through and pass this up the UDP socket. 671 * up->encap_rcv() returns the following value: 672 * =0 if skb was successfully passed to the encap 673 * handler or was discarded by it. 674 * >0 if skb should be passed on to UDP. 675 * <0 if skb should be resubmitted as proto -N 676 */ 677 678 /* if we're overly short, let UDP handle it */ 679 encap_rcv = READ_ONCE(up->encap_rcv); 680 if (encap_rcv) { 681 int ret; 682 683 /* Verify checksum before giving to encap */ 684 if (udp_lib_checksum_complete(skb)) 685 goto csum_error; 686 687 ret = encap_rcv(sk, skb); 688 if (ret <= 0) { 689 __UDP_INC_STATS(sock_net(sk), 690 UDP_MIB_INDATAGRAMS, 691 is_udplite); 692 return -ret; 693 } 694 } 695 696 /* FALLTHROUGH -- it's a UDP Packet */ 697 } 698 699 /* 700 * UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c). 701 */ 702 if ((up->pcflag & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { 703 704 if (up->pcrlen == 0) { /* full coverage was set */ 705 net_dbg_ratelimited("UDPLITE6: partial coverage %d while full coverage %d requested\n", 706 UDP_SKB_CB(skb)->cscov, skb->len); 707 goto drop; 708 } 709 if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { 710 net_dbg_ratelimited("UDPLITE6: coverage %d too small, need min %d\n", 711 UDP_SKB_CB(skb)->cscov, up->pcrlen); 712 goto drop; 713 } 714 } 715 716 prefetch(&sk->sk_rmem_alloc); 717 if (rcu_access_pointer(sk->sk_filter) && 718 udp_lib_checksum_complete(skb)) 719 goto csum_error; 720 721 if (sk_filter_trim_cap(sk, skb, sizeof(struct udphdr))) 722 goto drop; 723 724 udp_csum_pull_header(skb); 725 726 skb_dst_drop(skb); 727 728 return __udpv6_queue_rcv_skb(sk, skb); 729 730 csum_error: 731 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_CSUMERRORS, is_udplite); 732 drop: 733 __UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite); 734 atomic_inc(&sk->sk_drops); 735 kfree_skb(skb); 736 return -1; 737 } 738 739 static int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 740 { 741 struct sk_buff *next, *segs; 742 int ret; 743 744 if (likely(!udp_unexpected_gso(sk, skb))) 745 return udpv6_queue_rcv_one_skb(sk, skb); 746 747 __skb_push(skb, -skb_mac_offset(skb)); 748 segs = udp_rcv_segment(sk, skb, false); 749 skb_list_walk_safe(segs, skb, next) { 750 __skb_pull(skb, skb_transport_offset(skb)); 751 752 udp_post_segment_fix_csum(skb); 753 ret = udpv6_queue_rcv_one_skb(sk, skb); 754 if (ret > 0) 755 ip6_protocol_deliver_rcu(dev_net(skb->dev), skb, ret, 756 true); 757 } 758 return 0; 759 } 760 761 static bool __udp_v6_is_mcast_sock(struct net *net, struct sock *sk, 762 __be16 loc_port, const struct in6_addr *loc_addr, 763 __be16 rmt_port, const struct in6_addr *rmt_addr, 764 int dif, int sdif, unsigned short hnum) 765 { 766 struct inet_sock *inet = inet_sk(sk); 767 768 if (!net_eq(sock_net(sk), net)) 769 return false; 770 771 if (udp_sk(sk)->udp_port_hash != hnum || 772 sk->sk_family != PF_INET6 || 773 (inet->inet_dport && inet->inet_dport != rmt_port) || 774 (!ipv6_addr_any(&sk->sk_v6_daddr) && 775 !ipv6_addr_equal(&sk->sk_v6_daddr, rmt_addr)) || 776 !udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif) || 777 (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) && 778 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr, loc_addr))) 779 return false; 780 if (!inet6_mc_check(sk, loc_addr, rmt_addr)) 781 return false; 782 return true; 783 } 784 785 static void udp6_csum_zero_error(struct sk_buff *skb) 786 { 787 /* RFC 2460 section 8.1 says that we SHOULD log 788 * this error. Well, it is reasonable. 789 */ 790 net_dbg_ratelimited("IPv6: udp checksum is 0 for [%pI6c]:%u->[%pI6c]:%u\n", 791 &ipv6_hdr(skb)->saddr, ntohs(udp_hdr(skb)->source), 792 &ipv6_hdr(skb)->daddr, ntohs(udp_hdr(skb)->dest)); 793 } 794 795 /* 796 * Note: called only from the BH handler context, 797 * so we don't need to lock the hashes. 798 */ 799 static int __udp6_lib_mcast_deliver(struct net *net, struct sk_buff *skb, 800 const struct in6_addr *saddr, const struct in6_addr *daddr, 801 struct udp_table *udptable, int proto) 802 { 803 struct sock *sk, *first = NULL; 804 const struct udphdr *uh = udp_hdr(skb); 805 unsigned short hnum = ntohs(uh->dest); 806 struct udp_hslot *hslot = udp_hashslot(udptable, net, hnum); 807 unsigned int offset = offsetof(typeof(*sk), sk_node); 808 unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); 809 int dif = inet6_iif(skb); 810 int sdif = inet6_sdif(skb); 811 struct hlist_node *node; 812 struct sk_buff *nskb; 813 814 if (use_hash2) { 815 hash2_any = ipv6_portaddr_hash(net, &in6addr_any, hnum) & 816 udptable->mask; 817 hash2 = ipv6_portaddr_hash(net, daddr, hnum) & udptable->mask; 818 start_lookup: 819 hslot = &udptable->hash2[hash2]; 820 offset = offsetof(typeof(*sk), __sk_common.skc_portaddr_node); 821 } 822 823 sk_for_each_entry_offset_rcu(sk, node, &hslot->head, offset) { 824 if (!__udp_v6_is_mcast_sock(net, sk, uh->dest, daddr, 825 uh->source, saddr, dif, sdif, 826 hnum)) 827 continue; 828 /* If zero checksum and no_check is not on for 829 * the socket then skip it. 830 */ 831 if (!uh->check && !udp_sk(sk)->no_check6_rx) 832 continue; 833 if (!first) { 834 first = sk; 835 continue; 836 } 837 nskb = skb_clone(skb, GFP_ATOMIC); 838 if (unlikely(!nskb)) { 839 atomic_inc(&sk->sk_drops); 840 __UDP6_INC_STATS(net, UDP_MIB_RCVBUFERRORS, 841 IS_UDPLITE(sk)); 842 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, 843 IS_UDPLITE(sk)); 844 continue; 845 } 846 847 if (udpv6_queue_rcv_skb(sk, nskb) > 0) 848 consume_skb(nskb); 849 } 850 851 /* Also lookup *:port if we are using hash2 and haven't done so yet. */ 852 if (use_hash2 && hash2 != hash2_any) { 853 hash2 = hash2_any; 854 goto start_lookup; 855 } 856 857 if (first) { 858 if (udpv6_queue_rcv_skb(first, skb) > 0) 859 consume_skb(skb); 860 } else { 861 kfree_skb(skb); 862 __UDP6_INC_STATS(net, UDP_MIB_IGNOREDMULTI, 863 proto == IPPROTO_UDPLITE); 864 } 865 return 0; 866 } 867 868 static void udp6_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) 869 { 870 if (udp_sk_rx_dst_set(sk, dst)) { 871 const struct rt6_info *rt = (const struct rt6_info *)dst; 872 873 inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt); 874 } 875 } 876 877 /* wrapper for udp_queue_rcv_skb tacking care of csum conversion and 878 * return code conversion for ip layer consumption 879 */ 880 static int udp6_unicast_rcv_skb(struct sock *sk, struct sk_buff *skb, 881 struct udphdr *uh) 882 { 883 int ret; 884 885 if (inet_get_convert_csum(sk) && uh->check && !IS_UDPLITE(sk)) 886 skb_checksum_try_convert(skb, IPPROTO_UDP, ip6_compute_pseudo); 887 888 ret = udpv6_queue_rcv_skb(sk, skb); 889 890 /* a return value > 0 means to resubmit the input */ 891 if (ret > 0) 892 return ret; 893 return 0; 894 } 895 896 int __udp6_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, 897 int proto) 898 { 899 const struct in6_addr *saddr, *daddr; 900 struct net *net = dev_net(skb->dev); 901 struct udphdr *uh; 902 struct sock *sk; 903 bool refcounted; 904 u32 ulen = 0; 905 906 if (!pskb_may_pull(skb, sizeof(struct udphdr))) 907 goto discard; 908 909 saddr = &ipv6_hdr(skb)->saddr; 910 daddr = &ipv6_hdr(skb)->daddr; 911 uh = udp_hdr(skb); 912 913 ulen = ntohs(uh->len); 914 if (ulen > skb->len) 915 goto short_packet; 916 917 if (proto == IPPROTO_UDP) { 918 /* UDP validates ulen. */ 919 920 /* Check for jumbo payload */ 921 if (ulen == 0) 922 ulen = skb->len; 923 924 if (ulen < sizeof(*uh)) 925 goto short_packet; 926 927 if (ulen < skb->len) { 928 if (pskb_trim_rcsum(skb, ulen)) 929 goto short_packet; 930 saddr = &ipv6_hdr(skb)->saddr; 931 daddr = &ipv6_hdr(skb)->daddr; 932 uh = udp_hdr(skb); 933 } 934 } 935 936 if (udp6_csum_init(skb, uh, proto)) 937 goto csum_error; 938 939 /* Check if the socket is already available, e.g. due to early demux */ 940 sk = skb_steal_sock(skb, &refcounted); 941 if (sk) { 942 struct dst_entry *dst = skb_dst(skb); 943 int ret; 944 945 if (unlikely(sk->sk_rx_dst != dst)) 946 udp6_sk_rx_dst_set(sk, dst); 947 948 if (!uh->check && !udp_sk(sk)->no_check6_rx) { 949 if (refcounted) 950 sock_put(sk); 951 goto report_csum_error; 952 } 953 954 ret = udp6_unicast_rcv_skb(sk, skb, uh); 955 if (refcounted) 956 sock_put(sk); 957 return ret; 958 } 959 960 /* 961 * Multicast receive code 962 */ 963 if (ipv6_addr_is_multicast(daddr)) 964 return __udp6_lib_mcast_deliver(net, skb, 965 saddr, daddr, udptable, proto); 966 967 /* Unicast */ 968 sk = __udp6_lib_lookup_skb(skb, uh->source, uh->dest, udptable); 969 if (sk) { 970 if (!uh->check && !udp_sk(sk)->no_check6_rx) 971 goto report_csum_error; 972 return udp6_unicast_rcv_skb(sk, skb, uh); 973 } 974 975 if (!uh->check) 976 goto report_csum_error; 977 978 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 979 goto discard; 980 981 if (udp_lib_checksum_complete(skb)) 982 goto csum_error; 983 984 __UDP6_INC_STATS(net, UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE); 985 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); 986 987 kfree_skb(skb); 988 return 0; 989 990 short_packet: 991 net_dbg_ratelimited("UDP%sv6: short packet: From [%pI6c]:%u %d/%d to [%pI6c]:%u\n", 992 proto == IPPROTO_UDPLITE ? "-Lite" : "", 993 saddr, ntohs(uh->source), 994 ulen, skb->len, 995 daddr, ntohs(uh->dest)); 996 goto discard; 997 998 report_csum_error: 999 udp6_csum_zero_error(skb); 1000 csum_error: 1001 __UDP6_INC_STATS(net, UDP_MIB_CSUMERRORS, proto == IPPROTO_UDPLITE); 1002 discard: 1003 __UDP6_INC_STATS(net, UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE); 1004 kfree_skb(skb); 1005 return 0; 1006 } 1007 1008 1009 static struct sock *__udp6_lib_demux_lookup(struct net *net, 1010 __be16 loc_port, const struct in6_addr *loc_addr, 1011 __be16 rmt_port, const struct in6_addr *rmt_addr, 1012 int dif, int sdif) 1013 { 1014 unsigned short hnum = ntohs(loc_port); 1015 unsigned int hash2 = ipv6_portaddr_hash(net, loc_addr, hnum); 1016 unsigned int slot2 = hash2 & udp_table.mask; 1017 struct udp_hslot *hslot2 = &udp_table.hash2[slot2]; 1018 const __portpair ports = INET_COMBINED_PORTS(rmt_port, hnum); 1019 struct sock *sk; 1020 1021 udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) { 1022 if (sk->sk_state == TCP_ESTABLISHED && 1023 INET6_MATCH(sk, net, rmt_addr, loc_addr, ports, dif, sdif)) 1024 return sk; 1025 /* Only check first socket in chain */ 1026 break; 1027 } 1028 return NULL; 1029 } 1030 1031 INDIRECT_CALLABLE_SCOPE void udp_v6_early_demux(struct sk_buff *skb) 1032 { 1033 struct net *net = dev_net(skb->dev); 1034 const struct udphdr *uh; 1035 struct sock *sk; 1036 struct dst_entry *dst; 1037 int dif = skb->dev->ifindex; 1038 int sdif = inet6_sdif(skb); 1039 1040 if (!pskb_may_pull(skb, skb_transport_offset(skb) + 1041 sizeof(struct udphdr))) 1042 return; 1043 1044 uh = udp_hdr(skb); 1045 1046 if (skb->pkt_type == PACKET_HOST) 1047 sk = __udp6_lib_demux_lookup(net, uh->dest, 1048 &ipv6_hdr(skb)->daddr, 1049 uh->source, &ipv6_hdr(skb)->saddr, 1050 dif, sdif); 1051 else 1052 return; 1053 1054 if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) 1055 return; 1056 1057 skb->sk = sk; 1058 skb->destructor = sock_efree; 1059 dst = READ_ONCE(sk->sk_rx_dst); 1060 1061 if (dst) 1062 dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie); 1063 if (dst) { 1064 /* set noref for now. 1065 * any place which wants to hold dst has to call 1066 * dst_hold_safe() 1067 */ 1068 skb_dst_set_noref(skb, dst); 1069 } 1070 } 1071 1072 INDIRECT_CALLABLE_SCOPE int udpv6_rcv(struct sk_buff *skb) 1073 { 1074 return __udp6_lib_rcv(skb, &udp_table, IPPROTO_UDP); 1075 } 1076 1077 /* 1078 * Throw away all pending data and cancel the corking. Socket is locked. 1079 */ 1080 static void udp_v6_flush_pending_frames(struct sock *sk) 1081 { 1082 struct udp_sock *up = udp_sk(sk); 1083 1084 if (up->pending == AF_INET) 1085 udp_flush_pending_frames(sk); 1086 else if (up->pending) { 1087 up->len = 0; 1088 up->pending = 0; 1089 ip6_flush_pending_frames(sk); 1090 } 1091 } 1092 1093 static int udpv6_pre_connect(struct sock *sk, struct sockaddr *uaddr, 1094 int addr_len) 1095 { 1096 if (addr_len < offsetofend(struct sockaddr, sa_family)) 1097 return -EINVAL; 1098 /* The following checks are replicated from __ip6_datagram_connect() 1099 * and intended to prevent BPF program called below from accessing 1100 * bytes that are out of the bound specified by user in addr_len. 1101 */ 1102 if (uaddr->sa_family == AF_INET) { 1103 if (__ipv6_only_sock(sk)) 1104 return -EAFNOSUPPORT; 1105 return udp_pre_connect(sk, uaddr, addr_len); 1106 } 1107 1108 if (addr_len < SIN6_LEN_RFC2133) 1109 return -EINVAL; 1110 1111 return BPF_CGROUP_RUN_PROG_INET6_CONNECT_LOCK(sk, uaddr); 1112 } 1113 1114 /** 1115 * udp6_hwcsum_outgoing - handle outgoing HW checksumming 1116 * @sk: socket we are sending on 1117 * @skb: sk_buff containing the filled-in UDP header 1118 * (checksum field must be zeroed out) 1119 * @saddr: source address 1120 * @daddr: destination address 1121 * @len: length of packet 1122 */ 1123 static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, 1124 const struct in6_addr *saddr, 1125 const struct in6_addr *daddr, int len) 1126 { 1127 unsigned int offset; 1128 struct udphdr *uh = udp_hdr(skb); 1129 struct sk_buff *frags = skb_shinfo(skb)->frag_list; 1130 __wsum csum = 0; 1131 1132 if (!frags) { 1133 /* Only one fragment on the socket. */ 1134 skb->csum_start = skb_transport_header(skb) - skb->head; 1135 skb->csum_offset = offsetof(struct udphdr, check); 1136 uh->check = ~csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 0); 1137 } else { 1138 /* 1139 * HW-checksum won't work as there are two or more 1140 * fragments on the socket so that all csums of sk_buffs 1141 * should be together 1142 */ 1143 offset = skb_transport_offset(skb); 1144 skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); 1145 csum = skb->csum; 1146 1147 skb->ip_summed = CHECKSUM_NONE; 1148 1149 do { 1150 csum = csum_add(csum, frags->csum); 1151 } while ((frags = frags->next)); 1152 1153 uh->check = csum_ipv6_magic(saddr, daddr, len, IPPROTO_UDP, 1154 csum); 1155 if (uh->check == 0) 1156 uh->check = CSUM_MANGLED_0; 1157 } 1158 } 1159 1160 /* 1161 * Sending 1162 */ 1163 1164 static int udp_v6_send_skb(struct sk_buff *skb, struct flowi6 *fl6, 1165 struct inet_cork *cork) 1166 { 1167 struct sock *sk = skb->sk; 1168 struct udphdr *uh; 1169 int err = 0; 1170 int is_udplite = IS_UDPLITE(sk); 1171 __wsum csum = 0; 1172 int offset = skb_transport_offset(skb); 1173 int len = skb->len - offset; 1174 int datalen = len - sizeof(*uh); 1175 1176 /* 1177 * Create a UDP header 1178 */ 1179 uh = udp_hdr(skb); 1180 uh->source = fl6->fl6_sport; 1181 uh->dest = fl6->fl6_dport; 1182 uh->len = htons(len); 1183 uh->check = 0; 1184 1185 if (cork->gso_size) { 1186 const int hlen = skb_network_header_len(skb) + 1187 sizeof(struct udphdr); 1188 1189 if (hlen + cork->gso_size > cork->fragsize) { 1190 kfree_skb(skb); 1191 return -EINVAL; 1192 } 1193 if (skb->len > cork->gso_size * UDP_MAX_SEGMENTS) { 1194 kfree_skb(skb); 1195 return -EINVAL; 1196 } 1197 if (udp_sk(sk)->no_check6_tx) { 1198 kfree_skb(skb); 1199 return -EINVAL; 1200 } 1201 if (skb->ip_summed != CHECKSUM_PARTIAL || is_udplite || 1202 dst_xfrm(skb_dst(skb))) { 1203 kfree_skb(skb); 1204 return -EIO; 1205 } 1206 1207 if (datalen > cork->gso_size) { 1208 skb_shinfo(skb)->gso_size = cork->gso_size; 1209 skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4; 1210 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen, 1211 cork->gso_size); 1212 } 1213 goto csum_partial; 1214 } 1215 1216 if (is_udplite) 1217 csum = udplite_csum(skb); 1218 else if (udp_sk(sk)->no_check6_tx) { /* UDP csum disabled */ 1219 skb->ip_summed = CHECKSUM_NONE; 1220 goto send; 1221 } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ 1222 csum_partial: 1223 udp6_hwcsum_outgoing(sk, skb, &fl6->saddr, &fl6->daddr, len); 1224 goto send; 1225 } else 1226 csum = udp_csum(skb); 1227 1228 /* add protocol-dependent pseudo-header */ 1229 uh->check = csum_ipv6_magic(&fl6->saddr, &fl6->daddr, 1230 len, fl6->flowi6_proto, csum); 1231 if (uh->check == 0) 1232 uh->check = CSUM_MANGLED_0; 1233 1234 send: 1235 err = ip6_send_skb(skb); 1236 if (err) { 1237 if (err == -ENOBUFS && !inet6_sk(sk)->recverr) { 1238 UDP6_INC_STATS(sock_net(sk), 1239 UDP_MIB_SNDBUFERRORS, is_udplite); 1240 err = 0; 1241 } 1242 } else { 1243 UDP6_INC_STATS(sock_net(sk), 1244 UDP_MIB_OUTDATAGRAMS, is_udplite); 1245 } 1246 return err; 1247 } 1248 1249 static int udp_v6_push_pending_frames(struct sock *sk) 1250 { 1251 struct sk_buff *skb; 1252 struct udp_sock *up = udp_sk(sk); 1253 struct flowi6 fl6; 1254 int err = 0; 1255 1256 if (up->pending == AF_INET) 1257 return udp_push_pending_frames(sk); 1258 1259 /* ip6_finish_skb will release the cork, so make a copy of 1260 * fl6 here. 1261 */ 1262 fl6 = inet_sk(sk)->cork.fl.u.ip6; 1263 1264 skb = ip6_finish_skb(sk); 1265 if (!skb) 1266 goto out; 1267 1268 err = udp_v6_send_skb(skb, &fl6, &inet_sk(sk)->cork.base); 1269 1270 out: 1271 up->len = 0; 1272 up->pending = 0; 1273 return err; 1274 } 1275 1276 int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 1277 { 1278 struct ipv6_txoptions opt_space; 1279 struct udp_sock *up = udp_sk(sk); 1280 struct inet_sock *inet = inet_sk(sk); 1281 struct ipv6_pinfo *np = inet6_sk(sk); 1282 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name); 1283 struct in6_addr *daddr, *final_p, final; 1284 struct ipv6_txoptions *opt = NULL; 1285 struct ipv6_txoptions *opt_to_free = NULL; 1286 struct ip6_flowlabel *flowlabel = NULL; 1287 struct flowi6 fl6; 1288 struct dst_entry *dst; 1289 struct ipcm6_cookie ipc6; 1290 int addr_len = msg->msg_namelen; 1291 bool connected = false; 1292 int ulen = len; 1293 int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; 1294 int err; 1295 int is_udplite = IS_UDPLITE(sk); 1296 int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); 1297 1298 ipcm6_init(&ipc6); 1299 ipc6.gso_size = up->gso_size; 1300 ipc6.sockc.tsflags = sk->sk_tsflags; 1301 ipc6.sockc.mark = sk->sk_mark; 1302 1303 /* destination address check */ 1304 if (sin6) { 1305 if (addr_len < offsetof(struct sockaddr, sa_data)) 1306 return -EINVAL; 1307 1308 switch (sin6->sin6_family) { 1309 case AF_INET6: 1310 if (addr_len < SIN6_LEN_RFC2133) 1311 return -EINVAL; 1312 daddr = &sin6->sin6_addr; 1313 if (ipv6_addr_any(daddr) && 1314 ipv6_addr_v4mapped(&np->saddr)) 1315 ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), 1316 daddr); 1317 break; 1318 case AF_INET: 1319 goto do_udp_sendmsg; 1320 case AF_UNSPEC: 1321 msg->msg_name = sin6 = NULL; 1322 msg->msg_namelen = addr_len = 0; 1323 daddr = NULL; 1324 break; 1325 default: 1326 return -EINVAL; 1327 } 1328 } else if (!up->pending) { 1329 if (sk->sk_state != TCP_ESTABLISHED) 1330 return -EDESTADDRREQ; 1331 daddr = &sk->sk_v6_daddr; 1332 } else 1333 daddr = NULL; 1334 1335 if (daddr) { 1336 if (ipv6_addr_v4mapped(daddr)) { 1337 struct sockaddr_in sin; 1338 sin.sin_family = AF_INET; 1339 sin.sin_port = sin6 ? sin6->sin6_port : inet->inet_dport; 1340 sin.sin_addr.s_addr = daddr->s6_addr32[3]; 1341 msg->msg_name = &sin; 1342 msg->msg_namelen = sizeof(sin); 1343 do_udp_sendmsg: 1344 if (__ipv6_only_sock(sk)) 1345 return -ENETUNREACH; 1346 return udp_sendmsg(sk, msg, len); 1347 } 1348 } 1349 1350 if (up->pending == AF_INET) 1351 return udp_sendmsg(sk, msg, len); 1352 1353 /* Rough check on arithmetic overflow, 1354 better check is made in ip6_append_data(). 1355 */ 1356 if (len > INT_MAX - sizeof(struct udphdr)) 1357 return -EMSGSIZE; 1358 1359 getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; 1360 if (up->pending) { 1361 /* 1362 * There are pending frames. 1363 * The socket lock must be held while it's corked. 1364 */ 1365 lock_sock(sk); 1366 if (likely(up->pending)) { 1367 if (unlikely(up->pending != AF_INET6)) { 1368 release_sock(sk); 1369 return -EAFNOSUPPORT; 1370 } 1371 dst = NULL; 1372 goto do_append_data; 1373 } 1374 release_sock(sk); 1375 } 1376 ulen += sizeof(struct udphdr); 1377 1378 memset(&fl6, 0, sizeof(fl6)); 1379 1380 if (sin6) { 1381 if (sin6->sin6_port == 0) 1382 return -EINVAL; 1383 1384 fl6.fl6_dport = sin6->sin6_port; 1385 daddr = &sin6->sin6_addr; 1386 1387 if (np->sndflow) { 1388 fl6.flowlabel = sin6->sin6_flowinfo&IPV6_FLOWINFO_MASK; 1389 if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { 1390 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 1391 if (IS_ERR(flowlabel)) 1392 return -EINVAL; 1393 } 1394 } 1395 1396 /* 1397 * Otherwise it will be difficult to maintain 1398 * sk->sk_dst_cache. 1399 */ 1400 if (sk->sk_state == TCP_ESTABLISHED && 1401 ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) 1402 daddr = &sk->sk_v6_daddr; 1403 1404 if (addr_len >= sizeof(struct sockaddr_in6) && 1405 sin6->sin6_scope_id && 1406 __ipv6_addr_needs_scope_id(__ipv6_addr_type(daddr))) 1407 fl6.flowi6_oif = sin6->sin6_scope_id; 1408 } else { 1409 if (sk->sk_state != TCP_ESTABLISHED) 1410 return -EDESTADDRREQ; 1411 1412 fl6.fl6_dport = inet->inet_dport; 1413 daddr = &sk->sk_v6_daddr; 1414 fl6.flowlabel = np->flow_label; 1415 connected = true; 1416 } 1417 1418 if (!fl6.flowi6_oif) 1419 fl6.flowi6_oif = sk->sk_bound_dev_if; 1420 1421 if (!fl6.flowi6_oif) 1422 fl6.flowi6_oif = np->sticky_pktinfo.ipi6_ifindex; 1423 1424 fl6.flowi6_mark = ipc6.sockc.mark; 1425 fl6.flowi6_uid = sk->sk_uid; 1426 1427 if (msg->msg_controllen) { 1428 opt = &opt_space; 1429 memset(opt, 0, sizeof(struct ipv6_txoptions)); 1430 opt->tot_len = sizeof(*opt); 1431 ipc6.opt = opt; 1432 1433 err = udp_cmsg_send(sk, msg, &ipc6.gso_size); 1434 if (err > 0) 1435 err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, 1436 &ipc6); 1437 if (err < 0) { 1438 fl6_sock_release(flowlabel); 1439 return err; 1440 } 1441 if ((fl6.flowlabel&IPV6_FLOWLABEL_MASK) && !flowlabel) { 1442 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 1443 if (IS_ERR(flowlabel)) 1444 return -EINVAL; 1445 } 1446 if (!(opt->opt_nflen|opt->opt_flen)) 1447 opt = NULL; 1448 connected = false; 1449 } 1450 if (!opt) { 1451 opt = txopt_get(np); 1452 opt_to_free = opt; 1453 } 1454 if (flowlabel) 1455 opt = fl6_merge_options(&opt_space, flowlabel, opt); 1456 opt = ipv6_fixup_options(&opt_space, opt); 1457 ipc6.opt = opt; 1458 1459 fl6.flowi6_proto = sk->sk_protocol; 1460 fl6.daddr = *daddr; 1461 if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) 1462 fl6.saddr = np->saddr; 1463 fl6.fl6_sport = inet->inet_sport; 1464 1465 if (cgroup_bpf_enabled(BPF_CGROUP_UDP6_SENDMSG) && !connected) { 1466 err = BPF_CGROUP_RUN_PROG_UDP6_SENDMSG_LOCK(sk, 1467 (struct sockaddr *)sin6, &fl6.saddr); 1468 if (err) 1469 goto out_no_dst; 1470 if (sin6) { 1471 if (ipv6_addr_v4mapped(&sin6->sin6_addr)) { 1472 /* BPF program rewrote IPv6-only by IPv4-mapped 1473 * IPv6. It's currently unsupported. 1474 */ 1475 err = -ENOTSUPP; 1476 goto out_no_dst; 1477 } 1478 if (sin6->sin6_port == 0) { 1479 /* BPF program set invalid port. Reject it. */ 1480 err = -EINVAL; 1481 goto out_no_dst; 1482 } 1483 fl6.fl6_dport = sin6->sin6_port; 1484 fl6.daddr = sin6->sin6_addr; 1485 } 1486 } 1487 1488 if (ipv6_addr_any(&fl6.daddr)) 1489 fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ 1490 1491 final_p = fl6_update_dst(&fl6, opt, &final); 1492 if (final_p) 1493 connected = false; 1494 1495 if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) { 1496 fl6.flowi6_oif = np->mcast_oif; 1497 connected = false; 1498 } else if (!fl6.flowi6_oif) 1499 fl6.flowi6_oif = np->ucast_oif; 1500 1501 security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); 1502 1503 if (ipc6.tclass < 0) 1504 ipc6.tclass = np->tclass; 1505 1506 fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); 1507 1508 dst = ip6_sk_dst_lookup_flow(sk, &fl6, final_p, connected); 1509 if (IS_ERR(dst)) { 1510 err = PTR_ERR(dst); 1511 dst = NULL; 1512 goto out; 1513 } 1514 1515 if (ipc6.hlimit < 0) 1516 ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); 1517 1518 if (msg->msg_flags&MSG_CONFIRM) 1519 goto do_confirm; 1520 back_from_confirm: 1521 1522 /* Lockless fast path for the non-corking case */ 1523 if (!corkreq) { 1524 struct inet_cork_full cork; 1525 struct sk_buff *skb; 1526 1527 skb = ip6_make_skb(sk, getfrag, msg, ulen, 1528 sizeof(struct udphdr), &ipc6, 1529 &fl6, (struct rt6_info *)dst, 1530 msg->msg_flags, &cork); 1531 err = PTR_ERR(skb); 1532 if (!IS_ERR_OR_NULL(skb)) 1533 err = udp_v6_send_skb(skb, &fl6, &cork.base); 1534 goto out; 1535 } 1536 1537 lock_sock(sk); 1538 if (unlikely(up->pending)) { 1539 /* The socket is already corked while preparing it. */ 1540 /* ... which is an evident application bug. --ANK */ 1541 release_sock(sk); 1542 1543 net_dbg_ratelimited("udp cork app bug 2\n"); 1544 err = -EINVAL; 1545 goto out; 1546 } 1547 1548 up->pending = AF_INET6; 1549 1550 do_append_data: 1551 if (ipc6.dontfrag < 0) 1552 ipc6.dontfrag = np->dontfrag; 1553 up->len += ulen; 1554 err = ip6_append_data(sk, getfrag, msg, ulen, sizeof(struct udphdr), 1555 &ipc6, &fl6, (struct rt6_info *)dst, 1556 corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); 1557 if (err) 1558 udp_v6_flush_pending_frames(sk); 1559 else if (!corkreq) 1560 err = udp_v6_push_pending_frames(sk); 1561 else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) 1562 up->pending = 0; 1563 1564 if (err > 0) 1565 err = np->recverr ? net_xmit_errno(err) : 0; 1566 release_sock(sk); 1567 1568 out: 1569 dst_release(dst); 1570 out_no_dst: 1571 fl6_sock_release(flowlabel); 1572 txopt_put(opt_to_free); 1573 if (!err) 1574 return len; 1575 /* 1576 * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting 1577 * ENOBUFS might not be good (it's not tunable per se), but otherwise 1578 * we don't have a good statistic (IpOutDiscards but it can be too many 1579 * things). We could add another new stat but at least for now that 1580 * seems like overkill. 1581 */ 1582 if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { 1583 UDP6_INC_STATS(sock_net(sk), 1584 UDP_MIB_SNDBUFERRORS, is_udplite); 1585 } 1586 return err; 1587 1588 do_confirm: 1589 if (msg->msg_flags & MSG_PROBE) 1590 dst_confirm_neigh(dst, &fl6.daddr); 1591 if (!(msg->msg_flags&MSG_PROBE) || len) 1592 goto back_from_confirm; 1593 err = 0; 1594 goto out; 1595 } 1596 1597 void udpv6_destroy_sock(struct sock *sk) 1598 { 1599 struct udp_sock *up = udp_sk(sk); 1600 lock_sock(sk); 1601 udp_v6_flush_pending_frames(sk); 1602 release_sock(sk); 1603 1604 if (static_branch_unlikely(&udpv6_encap_needed_key)) { 1605 if (up->encap_type) { 1606 void (*encap_destroy)(struct sock *sk); 1607 encap_destroy = READ_ONCE(up->encap_destroy); 1608 if (encap_destroy) 1609 encap_destroy(sk); 1610 } 1611 if (up->encap_enabled) { 1612 static_branch_dec(&udpv6_encap_needed_key); 1613 udp_encap_disable(); 1614 } 1615 } 1616 1617 inet6_destroy_sock(sk); 1618 } 1619 1620 /* 1621 * Socket option code for UDP 1622 */ 1623 int udpv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, 1624 unsigned int optlen) 1625 { 1626 if (level == SOL_UDP || level == SOL_UDPLITE) 1627 return udp_lib_setsockopt(sk, level, optname, 1628 optval, optlen, 1629 udp_v6_push_pending_frames); 1630 return ipv6_setsockopt(sk, level, optname, optval, optlen); 1631 } 1632 1633 int udpv6_getsockopt(struct sock *sk, int level, int optname, 1634 char __user *optval, int __user *optlen) 1635 { 1636 if (level == SOL_UDP || level == SOL_UDPLITE) 1637 return udp_lib_getsockopt(sk, level, optname, optval, optlen); 1638 return ipv6_getsockopt(sk, level, optname, optval, optlen); 1639 } 1640 1641 /* thinking of making this const? Don't. 1642 * early_demux can change based on sysctl. 1643 */ 1644 static struct inet6_protocol udpv6_protocol = { 1645 .early_demux = udp_v6_early_demux, 1646 .early_demux_handler = udp_v6_early_demux, 1647 .handler = udpv6_rcv, 1648 .err_handler = udpv6_err, 1649 .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, 1650 }; 1651 1652 /* ------------------------------------------------------------------------ */ 1653 #ifdef CONFIG_PROC_FS 1654 int udp6_seq_show(struct seq_file *seq, void *v) 1655 { 1656 if (v == SEQ_START_TOKEN) { 1657 seq_puts(seq, IPV6_SEQ_DGRAM_HEADER); 1658 } else { 1659 int bucket = ((struct udp_iter_state *)seq->private)->bucket; 1660 struct inet_sock *inet = inet_sk(v); 1661 __u16 srcp = ntohs(inet->inet_sport); 1662 __u16 destp = ntohs(inet->inet_dport); 1663 __ip6_dgram_sock_seq_show(seq, v, srcp, destp, 1664 udp_rqueue_get(v), bucket); 1665 } 1666 return 0; 1667 } 1668 1669 const struct seq_operations udp6_seq_ops = { 1670 .start = udp_seq_start, 1671 .next = udp_seq_next, 1672 .stop = udp_seq_stop, 1673 .show = udp6_seq_show, 1674 }; 1675 EXPORT_SYMBOL(udp6_seq_ops); 1676 1677 static struct udp_seq_afinfo udp6_seq_afinfo = { 1678 .family = AF_INET6, 1679 .udp_table = &udp_table, 1680 }; 1681 1682 int __net_init udp6_proc_init(struct net *net) 1683 { 1684 if (!proc_create_net_data("udp6", 0444, net->proc_net, &udp6_seq_ops, 1685 sizeof(struct udp_iter_state), &udp6_seq_afinfo)) 1686 return -ENOMEM; 1687 return 0; 1688 } 1689 1690 void udp6_proc_exit(struct net *net) 1691 { 1692 remove_proc_entry("udp6", net->proc_net); 1693 } 1694 #endif /* CONFIG_PROC_FS */ 1695 1696 /* ------------------------------------------------------------------------ */ 1697 1698 struct proto udpv6_prot = { 1699 .name = "UDPv6", 1700 .owner = THIS_MODULE, 1701 .close = udp_lib_close, 1702 .pre_connect = udpv6_pre_connect, 1703 .connect = ip6_datagram_connect, 1704 .disconnect = udp_disconnect, 1705 .ioctl = udp_ioctl, 1706 .init = udp_init_sock, 1707 .destroy = udpv6_destroy_sock, 1708 .setsockopt = udpv6_setsockopt, 1709 .getsockopt = udpv6_getsockopt, 1710 .sendmsg = udpv6_sendmsg, 1711 .recvmsg = udpv6_recvmsg, 1712 .release_cb = ip6_datagram_release_cb, 1713 .hash = udp_lib_hash, 1714 .unhash = udp_lib_unhash, 1715 .rehash = udp_v6_rehash, 1716 .get_port = udp_v6_get_port, 1717 #ifdef CONFIG_BPF_SYSCALL 1718 .psock_update_sk_prot = udp_bpf_update_proto, 1719 #endif 1720 .memory_allocated = &udp_memory_allocated, 1721 .sysctl_mem = sysctl_udp_mem, 1722 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_udp_wmem_min), 1723 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_udp_rmem_min), 1724 .obj_size = sizeof(struct udp6_sock), 1725 .h.udp_table = &udp_table, 1726 .diag_destroy = udp_abort, 1727 }; 1728 1729 static struct inet_protosw udpv6_protosw = { 1730 .type = SOCK_DGRAM, 1731 .protocol = IPPROTO_UDP, 1732 .prot = &udpv6_prot, 1733 .ops = &inet6_dgram_ops, 1734 .flags = INET_PROTOSW_PERMANENT, 1735 }; 1736 1737 int __init udpv6_init(void) 1738 { 1739 int ret; 1740 1741 ret = inet6_add_protocol(&udpv6_protocol, IPPROTO_UDP); 1742 if (ret) 1743 goto out; 1744 1745 ret = inet6_register_protosw(&udpv6_protosw); 1746 if (ret) 1747 goto out_udpv6_protocol; 1748 out: 1749 return ret; 1750 1751 out_udpv6_protocol: 1752 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); 1753 goto out; 1754 } 1755 1756 void udpv6_exit(void) 1757 { 1758 inet6_unregister_protosw(&udpv6_protosw); 1759 inet6_del_protocol(&udpv6_protocol, IPPROTO_UDP); 1760 } 1761