1 /* 2 * DCCP over IPv6 3 * Linux INET6 implementation 4 * 5 * Based on net/dccp6/ipv6.c 6 * 7 * Arnaldo Carvalho de Melo <acme@ghostprotocols.net> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 */ 14 15 #include <linux/module.h> 16 #include <linux/random.h> 17 #include <linux/slab.h> 18 #include <linux/xfrm.h> 19 20 #include <net/addrconf.h> 21 #include <net/inet_common.h> 22 #include <net/inet_hashtables.h> 23 #include <net/inet_sock.h> 24 #include <net/inet6_connection_sock.h> 25 #include <net/inet6_hashtables.h> 26 #include <net/ip6_route.h> 27 #include <net/ipv6.h> 28 #include <net/protocol.h> 29 #include <net/transp_v6.h> 30 #include <net/ip6_checksum.h> 31 #include <net/xfrm.h> 32 #include <net/secure_seq.h> 33 34 #include "dccp.h" 35 #include "ipv6.h" 36 #include "feat.h" 37 38 /* The per-net dccp.v6_ctl_sk is used for sending RSTs and ACKs */ 39 40 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped; 41 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops; 42 43 /* add pseudo-header to DCCP checksum stored in skb->csum */ 44 static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb, 45 const struct in6_addr *saddr, 46 const struct in6_addr *daddr) 47 { 48 return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum); 49 } 50 51 static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb) 52 { 53 struct ipv6_pinfo *np = inet6_sk(sk); 54 struct dccp_hdr *dh = dccp_hdr(skb); 55 56 dccp_csum_outgoing(skb); 57 dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr); 58 } 59 60 static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb) 61 { 62 return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32, 63 ipv6_hdr(skb)->saddr.s6_addr32, 64 dccp_hdr(skb)->dccph_dport, 65 dccp_hdr(skb)->dccph_sport ); 66 67 } 68 69 static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 70 u8 type, u8 code, int offset, __be32 info) 71 { 72 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; 73 const struct dccp_hdr *dh; 74 struct dccp_sock *dp; 75 struct ipv6_pinfo *np; 76 struct sock *sk; 77 int err; 78 __u64 seq; 79 struct net *net = dev_net(skb->dev); 80 81 /* Only need dccph_dport & dccph_sport which are the first 82 * 4 bytes in dccp header. 83 * Our caller (icmpv6_notify()) already pulled 8 bytes for us. 84 */ 85 BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_sport) > 8); 86 BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_dport) > 8); 87 dh = (struct dccp_hdr *)(skb->data + offset); 88 89 sk = __inet6_lookup_established(net, &dccp_hashinfo, 90 &hdr->daddr, dh->dccph_dport, 91 &hdr->saddr, ntohs(dh->dccph_sport), 92 inet6_iif(skb)); 93 94 if (!sk) { 95 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), 96 ICMP6_MIB_INERRORS); 97 return; 98 } 99 100 if (sk->sk_state == DCCP_TIME_WAIT) { 101 inet_twsk_put(inet_twsk(sk)); 102 return; 103 } 104 seq = dccp_hdr_seq(dh); 105 if (sk->sk_state == DCCP_NEW_SYN_RECV) 106 return dccp_req_err(sk, seq); 107 108 bh_lock_sock(sk); 109 if (sock_owned_by_user(sk)) 110 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); 111 112 if (sk->sk_state == DCCP_CLOSED) 113 goto out; 114 115 dp = dccp_sk(sk); 116 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) && 117 !between48(seq, dp->dccps_awl, dp->dccps_awh)) { 118 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); 119 goto out; 120 } 121 122 np = inet6_sk(sk); 123 124 if (type == NDISC_REDIRECT) { 125 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); 126 127 if (dst) 128 dst->ops->redirect(dst, sk, skb); 129 goto out; 130 } 131 132 if (type == ICMPV6_PKT_TOOBIG) { 133 struct dst_entry *dst = NULL; 134 135 if (!ip6_sk_accept_pmtu(sk)) 136 goto out; 137 138 if (sock_owned_by_user(sk)) 139 goto out; 140 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED)) 141 goto out; 142 143 dst = inet6_csk_update_pmtu(sk, ntohl(info)); 144 if (!dst) 145 goto out; 146 147 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) 148 dccp_sync_mss(sk, dst_mtu(dst)); 149 goto out; 150 } 151 152 icmpv6_err_convert(type, code, &err); 153 154 /* Might be for an request_sock */ 155 switch (sk->sk_state) { 156 case DCCP_REQUESTING: 157 case DCCP_RESPOND: /* Cannot happen. 158 It can, it SYNs are crossed. --ANK */ 159 if (!sock_owned_by_user(sk)) { 160 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); 161 sk->sk_err = err; 162 /* 163 * Wake people up to see the error 164 * (see connect in sock.c) 165 */ 166 sk->sk_error_report(sk); 167 dccp_done(sk); 168 } else 169 sk->sk_err_soft = err; 170 goto out; 171 } 172 173 if (!sock_owned_by_user(sk) && np->recverr) { 174 sk->sk_err = err; 175 sk->sk_error_report(sk); 176 } else 177 sk->sk_err_soft = err; 178 179 out: 180 bh_unlock_sock(sk); 181 sock_put(sk); 182 } 183 184 185 static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req) 186 { 187 struct inet_request_sock *ireq = inet_rsk(req); 188 struct ipv6_pinfo *np = inet6_sk(sk); 189 struct sk_buff *skb; 190 struct in6_addr *final_p, final; 191 struct flowi6 fl6; 192 int err = -1; 193 struct dst_entry *dst; 194 195 memset(&fl6, 0, sizeof(fl6)); 196 fl6.flowi6_proto = IPPROTO_DCCP; 197 fl6.daddr = ireq->ir_v6_rmt_addr; 198 fl6.saddr = ireq->ir_v6_loc_addr; 199 fl6.flowlabel = 0; 200 fl6.flowi6_oif = ireq->ir_iif; 201 fl6.fl6_dport = ireq->ir_rmt_port; 202 fl6.fl6_sport = htons(ireq->ir_num); 203 security_req_classify_flow(req, flowi6_to_flowi(&fl6)); 204 205 206 rcu_read_lock(); 207 final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final); 208 rcu_read_unlock(); 209 210 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 211 if (IS_ERR(dst)) { 212 err = PTR_ERR(dst); 213 dst = NULL; 214 goto done; 215 } 216 217 skb = dccp_make_response(sk, dst, req); 218 if (skb != NULL) { 219 struct dccp_hdr *dh = dccp_hdr(skb); 220 struct ipv6_txoptions *opt; 221 222 dh->dccph_checksum = dccp_v6_csum_finish(skb, 223 &ireq->ir_v6_loc_addr, 224 &ireq->ir_v6_rmt_addr); 225 fl6.daddr = ireq->ir_v6_rmt_addr; 226 rcu_read_lock(); 227 opt = ireq->ipv6_opt; 228 if (!opt) 229 opt = rcu_dereference(np->opt); 230 err = ip6_xmit(sk, skb, &fl6, opt, np->tclass); 231 rcu_read_unlock(); 232 err = net_xmit_eval(err); 233 } 234 235 done: 236 dst_release(dst); 237 return err; 238 } 239 240 static void dccp_v6_reqsk_destructor(struct request_sock *req) 241 { 242 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg); 243 kfree(inet_rsk(req)->ipv6_opt); 244 kfree_skb(inet_rsk(req)->pktopts); 245 } 246 247 static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb) 248 { 249 const struct ipv6hdr *rxip6h; 250 struct sk_buff *skb; 251 struct flowi6 fl6; 252 struct net *net = dev_net(skb_dst(rxskb)->dev); 253 struct sock *ctl_sk = net->dccp.v6_ctl_sk; 254 struct dst_entry *dst; 255 256 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET) 257 return; 258 259 if (!ipv6_unicast_destination(rxskb)) 260 return; 261 262 skb = dccp_ctl_make_reset(ctl_sk, rxskb); 263 if (skb == NULL) 264 return; 265 266 rxip6h = ipv6_hdr(rxskb); 267 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr, 268 &rxip6h->daddr); 269 270 memset(&fl6, 0, sizeof(fl6)); 271 fl6.daddr = rxip6h->saddr; 272 fl6.saddr = rxip6h->daddr; 273 274 fl6.flowi6_proto = IPPROTO_DCCP; 275 fl6.flowi6_oif = inet6_iif(rxskb); 276 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport; 277 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport; 278 security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6)); 279 280 /* sk = NULL, but it is safe for now. RST socket required. */ 281 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL); 282 if (!IS_ERR(dst)) { 283 skb_dst_set(skb, dst); 284 ip6_xmit(ctl_sk, skb, &fl6, NULL, 0); 285 DCCP_INC_STATS(DCCP_MIB_OUTSEGS); 286 DCCP_INC_STATS(DCCP_MIB_OUTRSTS); 287 return; 288 } 289 290 kfree_skb(skb); 291 } 292 293 static struct request_sock_ops dccp6_request_sock_ops = { 294 .family = AF_INET6, 295 .obj_size = sizeof(struct dccp6_request_sock), 296 .rtx_syn_ack = dccp_v6_send_response, 297 .send_ack = dccp_reqsk_send_ack, 298 .destructor = dccp_v6_reqsk_destructor, 299 .send_reset = dccp_v6_ctl_send_reset, 300 .syn_ack_timeout = dccp_syn_ack_timeout, 301 }; 302 303 static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb) 304 { 305 struct request_sock *req; 306 struct dccp_request_sock *dreq; 307 struct inet_request_sock *ireq; 308 struct ipv6_pinfo *np = inet6_sk(sk); 309 const __be32 service = dccp_hdr_request(skb)->dccph_req_service; 310 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); 311 312 if (skb->protocol == htons(ETH_P_IP)) 313 return dccp_v4_conn_request(sk, skb); 314 315 if (!ipv6_unicast_destination(skb)) 316 return 0; /* discard, don't send a reset here */ 317 318 if (dccp_bad_service_code(sk, service)) { 319 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE; 320 goto drop; 321 } 322 /* 323 * There are no SYN attacks on IPv6, yet... 324 */ 325 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY; 326 if (inet_csk_reqsk_queue_is_full(sk)) 327 goto drop; 328 329 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) 330 goto drop; 331 332 req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true); 333 if (req == NULL) 334 goto drop; 335 336 if (dccp_reqsk_init(req, dccp_sk(sk), skb)) 337 goto drop_and_free; 338 339 dreq = dccp_rsk(req); 340 if (dccp_parse_options(sk, dreq, skb)) 341 goto drop_and_free; 342 343 if (security_inet_conn_request(sk, skb, req)) 344 goto drop_and_free; 345 346 ireq = inet_rsk(req); 347 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; 348 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; 349 ireq->ireq_family = AF_INET6; 350 351 if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) || 352 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || 353 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) { 354 atomic_inc(&skb->users); 355 ireq->pktopts = skb; 356 } 357 ireq->ir_iif = sk->sk_bound_dev_if; 358 359 /* So that link locals have meaning */ 360 if (!sk->sk_bound_dev_if && 361 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) 362 ireq->ir_iif = inet6_iif(skb); 363 364 /* 365 * Step 3: Process LISTEN state 366 * 367 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie 368 * 369 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child(). 370 */ 371 dreq->dreq_isr = dcb->dccpd_seq; 372 dreq->dreq_gsr = dreq->dreq_isr; 373 dreq->dreq_iss = dccp_v6_init_sequence(skb); 374 dreq->dreq_gss = dreq->dreq_iss; 375 dreq->dreq_service = service; 376 377 if (dccp_v6_send_response(sk, req)) 378 goto drop_and_free; 379 380 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT); 381 return 0; 382 383 drop_and_free: 384 reqsk_free(req); 385 drop: 386 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); 387 return -1; 388 } 389 390 static struct sock *dccp_v6_request_recv_sock(const struct sock *sk, 391 struct sk_buff *skb, 392 struct request_sock *req, 393 struct dst_entry *dst, 394 struct request_sock *req_unhash, 395 bool *own_req) 396 { 397 struct inet_request_sock *ireq = inet_rsk(req); 398 struct ipv6_pinfo *newnp; 399 const struct ipv6_pinfo *np = inet6_sk(sk); 400 struct ipv6_txoptions *opt; 401 struct inet_sock *newinet; 402 struct dccp6_sock *newdp6; 403 struct sock *newsk; 404 405 if (skb->protocol == htons(ETH_P_IP)) { 406 /* 407 * v6 mapped 408 */ 409 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst, 410 req_unhash, own_req); 411 if (newsk == NULL) 412 return NULL; 413 414 newdp6 = (struct dccp6_sock *)newsk; 415 newinet = inet_sk(newsk); 416 newinet->pinet6 = &newdp6->inet6; 417 newnp = inet6_sk(newsk); 418 419 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 420 421 newnp->saddr = newsk->sk_v6_rcv_saddr; 422 423 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped; 424 newsk->sk_backlog_rcv = dccp_v4_do_rcv; 425 newnp->pktoptions = NULL; 426 newnp->opt = NULL; 427 newnp->mcast_oif = inet6_iif(skb); 428 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 429 430 /* 431 * No need to charge this sock to the relevant IPv6 refcnt debug socks count 432 * here, dccp_create_openreq_child now does this for us, see the comment in 433 * that function for the gory details. -acme 434 */ 435 436 /* It is tricky place. Until this moment IPv4 tcp 437 worked with IPv6 icsk.icsk_af_ops. 438 Sync it now. 439 */ 440 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); 441 442 return newsk; 443 } 444 445 446 if (sk_acceptq_is_full(sk)) 447 goto out_overflow; 448 449 if (!dst) { 450 struct flowi6 fl6; 451 452 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP); 453 if (!dst) 454 goto out; 455 } 456 457 newsk = dccp_create_openreq_child(sk, req, skb); 458 if (newsk == NULL) 459 goto out_nonewsk; 460 461 /* 462 * No need to charge this sock to the relevant IPv6 refcnt debug socks 463 * count here, dccp_create_openreq_child now does this for us, see the 464 * comment in that function for the gory details. -acme 465 */ 466 467 ip6_dst_store(newsk, dst, NULL, NULL); 468 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM | 469 NETIF_F_TSO); 470 newdp6 = (struct dccp6_sock *)newsk; 471 newinet = inet_sk(newsk); 472 newinet->pinet6 = &newdp6->inet6; 473 newnp = inet6_sk(newsk); 474 475 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 476 477 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; 478 newnp->saddr = ireq->ir_v6_loc_addr; 479 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; 480 newsk->sk_bound_dev_if = ireq->ir_iif; 481 482 /* Now IPv6 options... 483 484 First: no IPv4 options. 485 */ 486 newinet->inet_opt = NULL; 487 488 /* Clone RX bits */ 489 newnp->rxopt.all = np->rxopt.all; 490 491 newnp->pktoptions = NULL; 492 newnp->opt = NULL; 493 newnp->mcast_oif = inet6_iif(skb); 494 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 495 496 /* 497 * Clone native IPv6 options from listening socket (if any) 498 * 499 * Yes, keeping reference count would be much more clever, but we make 500 * one more one thing there: reattach optmem to newsk. 501 */ 502 opt = ireq->ipv6_opt; 503 if (!opt) 504 opt = rcu_dereference(np->opt); 505 if (opt) { 506 opt = ipv6_dup_options(newsk, opt); 507 RCU_INIT_POINTER(newnp->opt, opt); 508 } 509 inet_csk(newsk)->icsk_ext_hdr_len = 0; 510 if (opt) 511 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen + 512 opt->opt_flen; 513 514 dccp_sync_mss(newsk, dst_mtu(dst)); 515 516 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; 517 newinet->inet_rcv_saddr = LOOPBACK4_IPV6; 518 519 if (__inet_inherit_port(sk, newsk) < 0) { 520 inet_csk_prepare_forced_close(newsk); 521 dccp_done(newsk); 522 goto out; 523 } 524 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash)); 525 /* Clone pktoptions received with SYN, if we own the req */ 526 if (*own_req && ireq->pktopts) { 527 newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC); 528 consume_skb(ireq->pktopts); 529 ireq->pktopts = NULL; 530 if (newnp->pktoptions) 531 skb_set_owner_r(newnp->pktoptions, newsk); 532 } 533 534 return newsk; 535 536 out_overflow: 537 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); 538 out_nonewsk: 539 dst_release(dst); 540 out: 541 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); 542 return NULL; 543 } 544 545 /* The socket must have it's spinlock held when we get 546 * here. 547 * 548 * We have a potential double-lock case here, so even when 549 * doing backlog processing we use the BH locking scheme. 550 * This is because we cannot sleep with the original spinlock 551 * held. 552 */ 553 static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 554 { 555 struct ipv6_pinfo *np = inet6_sk(sk); 556 struct sk_buff *opt_skb = NULL; 557 558 /* Imagine: socket is IPv6. IPv4 packet arrives, 559 goes to IPv4 receive handler and backlogged. 560 From backlog it always goes here. Kerboom... 561 Fortunately, dccp_rcv_established and rcv_established 562 handle them correctly, but it is not case with 563 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK 564 */ 565 566 if (skb->protocol == htons(ETH_P_IP)) 567 return dccp_v4_do_rcv(sk, skb); 568 569 if (sk_filter(sk, skb)) 570 goto discard; 571 572 /* 573 * socket locking is here for SMP purposes as backlog rcv is currently 574 * called with bh processing disabled. 575 */ 576 577 /* Do Stevens' IPV6_PKTOPTIONS. 578 579 Yes, guys, it is the only place in our code, where we 580 may make it not affecting IPv4. 581 The rest of code is protocol independent, 582 and I do not like idea to uglify IPv4. 583 584 Actually, all the idea behind IPV6_PKTOPTIONS 585 looks not very well thought. For now we latch 586 options, received in the last packet, enqueued 587 by tcp. Feel free to propose better solution. 588 --ANK (980728) 589 */ 590 if (np->rxopt.all) 591 /* 592 * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below 593 * (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example. 594 */ 595 opt_skb = skb_clone(skb, GFP_ATOMIC); 596 597 if (sk->sk_state == DCCP_OPEN) { /* Fast path */ 598 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len)) 599 goto reset; 600 if (opt_skb) { 601 /* XXX This is where we would goto ipv6_pktoptions. */ 602 __kfree_skb(opt_skb); 603 } 604 return 0; 605 } 606 607 /* 608 * Step 3: Process LISTEN state 609 * If S.state == LISTEN, 610 * If P.type == Request or P contains a valid Init Cookie option, 611 * (* Must scan the packet's options to check for Init 612 * Cookies. Only Init Cookies are processed here, 613 * however; other options are processed in Step 8. This 614 * scan need only be performed if the endpoint uses Init 615 * Cookies *) 616 * (* Generate a new socket and switch to that socket *) 617 * Set S := new socket for this port pair 618 * S.state = RESPOND 619 * Choose S.ISS (initial seqno) or set from Init Cookies 620 * Initialize S.GAR := S.ISS 621 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies 622 * Continue with S.state == RESPOND 623 * (* A Response packet will be generated in Step 11 *) 624 * Otherwise, 625 * Generate Reset(No Connection) unless P.type == Reset 626 * Drop packet and return 627 * 628 * NOTE: the check for the packet types is done in 629 * dccp_rcv_state_process 630 */ 631 632 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len)) 633 goto reset; 634 if (opt_skb) { 635 /* XXX This is where we would goto ipv6_pktoptions. */ 636 __kfree_skb(opt_skb); 637 } 638 return 0; 639 640 reset: 641 dccp_v6_ctl_send_reset(sk, skb); 642 discard: 643 if (opt_skb != NULL) 644 __kfree_skb(opt_skb); 645 kfree_skb(skb); 646 return 0; 647 } 648 649 static int dccp_v6_rcv(struct sk_buff *skb) 650 { 651 const struct dccp_hdr *dh; 652 bool refcounted; 653 struct sock *sk; 654 int min_cov; 655 656 /* Step 1: Check header basics */ 657 658 if (dccp_invalid_packet(skb)) 659 goto discard_it; 660 661 /* Step 1: If header checksum is incorrect, drop packet and return. */ 662 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr, 663 &ipv6_hdr(skb)->daddr)) { 664 DCCP_WARN("dropped packet with invalid checksum\n"); 665 goto discard_it; 666 } 667 668 dh = dccp_hdr(skb); 669 670 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh); 671 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type; 672 673 if (dccp_packet_without_ack(skb)) 674 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ; 675 else 676 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb); 677 678 lookup: 679 sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh), 680 dh->dccph_sport, dh->dccph_dport, 681 inet6_iif(skb), &refcounted); 682 if (!sk) { 683 dccp_pr_debug("failed to look up flow ID in table and " 684 "get corresponding socket\n"); 685 goto no_dccp_socket; 686 } 687 688 /* 689 * Step 2: 690 * ... or S.state == TIMEWAIT, 691 * Generate Reset(No Connection) unless P.type == Reset 692 * Drop packet and return 693 */ 694 if (sk->sk_state == DCCP_TIME_WAIT) { 695 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n"); 696 inet_twsk_put(inet_twsk(sk)); 697 goto no_dccp_socket; 698 } 699 700 if (sk->sk_state == DCCP_NEW_SYN_RECV) { 701 struct request_sock *req = inet_reqsk(sk); 702 struct sock *nsk; 703 704 sk = req->rsk_listener; 705 if (unlikely(sk->sk_state != DCCP_LISTEN)) { 706 inet_csk_reqsk_queue_drop_and_put(sk, req); 707 goto lookup; 708 } 709 sock_hold(sk); 710 refcounted = true; 711 nsk = dccp_check_req(sk, skb, req); 712 if (!nsk) { 713 reqsk_put(req); 714 goto discard_and_relse; 715 } 716 if (nsk == sk) { 717 reqsk_put(req); 718 } else if (dccp_child_process(sk, nsk, skb)) { 719 dccp_v6_ctl_send_reset(sk, skb); 720 goto discard_and_relse; 721 } else { 722 sock_put(sk); 723 return 0; 724 } 725 } 726 /* 727 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage 728 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted 729 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov 730 */ 731 min_cov = dccp_sk(sk)->dccps_pcrlen; 732 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) { 733 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n", 734 dh->dccph_cscov, min_cov); 735 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */ 736 goto discard_and_relse; 737 } 738 739 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 740 goto discard_and_relse; 741 742 return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4, 743 refcounted) ? -1 : 0; 744 745 no_dccp_socket: 746 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 747 goto discard_it; 748 /* 749 * Step 2: 750 * If no socket ... 751 * Generate Reset(No Connection) unless P.type == Reset 752 * Drop packet and return 753 */ 754 if (dh->dccph_type != DCCP_PKT_RESET) { 755 DCCP_SKB_CB(skb)->dccpd_reset_code = 756 DCCP_RESET_CODE_NO_CONNECTION; 757 dccp_v6_ctl_send_reset(sk, skb); 758 } 759 760 discard_it: 761 kfree_skb(skb); 762 return 0; 763 764 discard_and_relse: 765 if (refcounted) 766 sock_put(sk); 767 goto discard_it; 768 } 769 770 static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr, 771 int addr_len) 772 { 773 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr; 774 struct inet_connection_sock *icsk = inet_csk(sk); 775 struct inet_sock *inet = inet_sk(sk); 776 struct ipv6_pinfo *np = inet6_sk(sk); 777 struct dccp_sock *dp = dccp_sk(sk); 778 struct in6_addr *saddr = NULL, *final_p, final; 779 struct ipv6_txoptions *opt; 780 struct flowi6 fl6; 781 struct dst_entry *dst; 782 int addr_type; 783 int err; 784 785 dp->dccps_role = DCCP_ROLE_CLIENT; 786 787 if (addr_len < SIN6_LEN_RFC2133) 788 return -EINVAL; 789 790 if (usin->sin6_family != AF_INET6) 791 return -EAFNOSUPPORT; 792 793 memset(&fl6, 0, sizeof(fl6)); 794 795 if (np->sndflow) { 796 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK; 797 IP6_ECN_flow_init(fl6.flowlabel); 798 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) { 799 struct ip6_flowlabel *flowlabel; 800 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 801 if (flowlabel == NULL) 802 return -EINVAL; 803 fl6_sock_release(flowlabel); 804 } 805 } 806 /* 807 * connect() to INADDR_ANY means loopback (BSD'ism). 808 */ 809 if (ipv6_addr_any(&usin->sin6_addr)) 810 usin->sin6_addr.s6_addr[15] = 1; 811 812 addr_type = ipv6_addr_type(&usin->sin6_addr); 813 814 if (addr_type & IPV6_ADDR_MULTICAST) 815 return -ENETUNREACH; 816 817 if (addr_type & IPV6_ADDR_LINKLOCAL) { 818 if (addr_len >= sizeof(struct sockaddr_in6) && 819 usin->sin6_scope_id) { 820 /* If interface is set while binding, indices 821 * must coincide. 822 */ 823 if (sk->sk_bound_dev_if && 824 sk->sk_bound_dev_if != usin->sin6_scope_id) 825 return -EINVAL; 826 827 sk->sk_bound_dev_if = usin->sin6_scope_id; 828 } 829 830 /* Connect to link-local address requires an interface */ 831 if (!sk->sk_bound_dev_if) 832 return -EINVAL; 833 } 834 835 sk->sk_v6_daddr = usin->sin6_addr; 836 np->flow_label = fl6.flowlabel; 837 838 /* 839 * DCCP over IPv4 840 */ 841 if (addr_type == IPV6_ADDR_MAPPED) { 842 u32 exthdrlen = icsk->icsk_ext_hdr_len; 843 struct sockaddr_in sin; 844 845 SOCK_DEBUG(sk, "connect: ipv4 mapped\n"); 846 847 if (__ipv6_only_sock(sk)) 848 return -ENETUNREACH; 849 850 sin.sin_family = AF_INET; 851 sin.sin_port = usin->sin6_port; 852 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; 853 854 icsk->icsk_af_ops = &dccp_ipv6_mapped; 855 sk->sk_backlog_rcv = dccp_v4_do_rcv; 856 857 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); 858 if (err) { 859 icsk->icsk_ext_hdr_len = exthdrlen; 860 icsk->icsk_af_ops = &dccp_ipv6_af_ops; 861 sk->sk_backlog_rcv = dccp_v6_do_rcv; 862 goto failure; 863 } 864 np->saddr = sk->sk_v6_rcv_saddr; 865 return err; 866 } 867 868 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 869 saddr = &sk->sk_v6_rcv_saddr; 870 871 fl6.flowi6_proto = IPPROTO_DCCP; 872 fl6.daddr = sk->sk_v6_daddr; 873 fl6.saddr = saddr ? *saddr : np->saddr; 874 fl6.flowi6_oif = sk->sk_bound_dev_if; 875 fl6.fl6_dport = usin->sin6_port; 876 fl6.fl6_sport = inet->inet_sport; 877 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 878 879 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk)); 880 final_p = fl6_update_dst(&fl6, opt, &final); 881 882 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 883 if (IS_ERR(dst)) { 884 err = PTR_ERR(dst); 885 goto failure; 886 } 887 888 if (saddr == NULL) { 889 saddr = &fl6.saddr; 890 sk->sk_v6_rcv_saddr = *saddr; 891 } 892 893 /* set the source address */ 894 np->saddr = *saddr; 895 inet->inet_rcv_saddr = LOOPBACK4_IPV6; 896 897 ip6_dst_store(sk, dst, NULL, NULL); 898 899 icsk->icsk_ext_hdr_len = 0; 900 if (opt) 901 icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen; 902 903 inet->inet_dport = usin->sin6_port; 904 905 dccp_set_state(sk, DCCP_REQUESTING); 906 err = inet6_hash_connect(&dccp_death_row, sk); 907 if (err) 908 goto late_failure; 909 910 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32, 911 sk->sk_v6_daddr.s6_addr32, 912 inet->inet_sport, 913 inet->inet_dport); 914 err = dccp_connect(sk); 915 if (err) 916 goto late_failure; 917 918 return 0; 919 920 late_failure: 921 dccp_set_state(sk, DCCP_CLOSED); 922 __sk_dst_reset(sk); 923 failure: 924 inet->inet_dport = 0; 925 sk->sk_route_caps = 0; 926 return err; 927 } 928 929 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = { 930 .queue_xmit = inet6_csk_xmit, 931 .send_check = dccp_v6_send_check, 932 .rebuild_header = inet6_sk_rebuild_header, 933 .conn_request = dccp_v6_conn_request, 934 .syn_recv_sock = dccp_v6_request_recv_sock, 935 .net_header_len = sizeof(struct ipv6hdr), 936 .setsockopt = ipv6_setsockopt, 937 .getsockopt = ipv6_getsockopt, 938 .addr2sockaddr = inet6_csk_addr2sockaddr, 939 .sockaddr_len = sizeof(struct sockaddr_in6), 940 .bind_conflict = inet6_csk_bind_conflict, 941 #ifdef CONFIG_COMPAT 942 .compat_setsockopt = compat_ipv6_setsockopt, 943 .compat_getsockopt = compat_ipv6_getsockopt, 944 #endif 945 }; 946 947 /* 948 * DCCP over IPv4 via INET6 API 949 */ 950 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = { 951 .queue_xmit = ip_queue_xmit, 952 .send_check = dccp_v4_send_check, 953 .rebuild_header = inet_sk_rebuild_header, 954 .conn_request = dccp_v6_conn_request, 955 .syn_recv_sock = dccp_v6_request_recv_sock, 956 .net_header_len = sizeof(struct iphdr), 957 .setsockopt = ipv6_setsockopt, 958 .getsockopt = ipv6_getsockopt, 959 .addr2sockaddr = inet6_csk_addr2sockaddr, 960 .sockaddr_len = sizeof(struct sockaddr_in6), 961 .bind_conflict = inet6_csk_bind_conflict, 962 #ifdef CONFIG_COMPAT 963 .compat_setsockopt = compat_ipv6_setsockopt, 964 .compat_getsockopt = compat_ipv6_getsockopt, 965 #endif 966 }; 967 968 /* NOTE: A lot of things set to zero explicitly by call to 969 * sk_alloc() so need not be done here. 970 */ 971 static int dccp_v6_init_sock(struct sock *sk) 972 { 973 static __u8 dccp_v6_ctl_sock_initialized; 974 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized); 975 976 if (err == 0) { 977 if (unlikely(!dccp_v6_ctl_sock_initialized)) 978 dccp_v6_ctl_sock_initialized = 1; 979 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops; 980 } 981 982 return err; 983 } 984 985 static void dccp_v6_destroy_sock(struct sock *sk) 986 { 987 dccp_destroy_sock(sk); 988 inet6_destroy_sock(sk); 989 } 990 991 static struct timewait_sock_ops dccp6_timewait_sock_ops = { 992 .twsk_obj_size = sizeof(struct dccp6_timewait_sock), 993 }; 994 995 static struct proto dccp_v6_prot = { 996 .name = "DCCPv6", 997 .owner = THIS_MODULE, 998 .close = dccp_close, 999 .connect = dccp_v6_connect, 1000 .disconnect = dccp_disconnect, 1001 .ioctl = dccp_ioctl, 1002 .init = dccp_v6_init_sock, 1003 .setsockopt = dccp_setsockopt, 1004 .getsockopt = dccp_getsockopt, 1005 .sendmsg = dccp_sendmsg, 1006 .recvmsg = dccp_recvmsg, 1007 .backlog_rcv = dccp_v6_do_rcv, 1008 .hash = inet6_hash, 1009 .unhash = inet_unhash, 1010 .accept = inet_csk_accept, 1011 .get_port = inet_csk_get_port, 1012 .shutdown = dccp_shutdown, 1013 .destroy = dccp_v6_destroy_sock, 1014 .orphan_count = &dccp_orphan_count, 1015 .max_header = MAX_DCCP_HEADER, 1016 .obj_size = sizeof(struct dccp6_sock), 1017 .slab_flags = SLAB_DESTROY_BY_RCU, 1018 .rsk_prot = &dccp6_request_sock_ops, 1019 .twsk_prot = &dccp6_timewait_sock_ops, 1020 .h.hashinfo = &dccp_hashinfo, 1021 #ifdef CONFIG_COMPAT 1022 .compat_setsockopt = compat_dccp_setsockopt, 1023 .compat_getsockopt = compat_dccp_getsockopt, 1024 #endif 1025 }; 1026 1027 static const struct inet6_protocol dccp_v6_protocol = { 1028 .handler = dccp_v6_rcv, 1029 .err_handler = dccp_v6_err, 1030 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1031 }; 1032 1033 static const struct proto_ops inet6_dccp_ops = { 1034 .family = PF_INET6, 1035 .owner = THIS_MODULE, 1036 .release = inet6_release, 1037 .bind = inet6_bind, 1038 .connect = inet_stream_connect, 1039 .socketpair = sock_no_socketpair, 1040 .accept = inet_accept, 1041 .getname = inet6_getname, 1042 .poll = dccp_poll, 1043 .ioctl = inet6_ioctl, 1044 .listen = inet_dccp_listen, 1045 .shutdown = inet_shutdown, 1046 .setsockopt = sock_common_setsockopt, 1047 .getsockopt = sock_common_getsockopt, 1048 .sendmsg = inet_sendmsg, 1049 .recvmsg = sock_common_recvmsg, 1050 .mmap = sock_no_mmap, 1051 .sendpage = sock_no_sendpage, 1052 #ifdef CONFIG_COMPAT 1053 .compat_setsockopt = compat_sock_common_setsockopt, 1054 .compat_getsockopt = compat_sock_common_getsockopt, 1055 #endif 1056 }; 1057 1058 static struct inet_protosw dccp_v6_protosw = { 1059 .type = SOCK_DCCP, 1060 .protocol = IPPROTO_DCCP, 1061 .prot = &dccp_v6_prot, 1062 .ops = &inet6_dccp_ops, 1063 .flags = INET_PROTOSW_ICSK, 1064 }; 1065 1066 static int __net_init dccp_v6_init_net(struct net *net) 1067 { 1068 if (dccp_hashinfo.bhash == NULL) 1069 return -ESOCKTNOSUPPORT; 1070 1071 return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6, 1072 SOCK_DCCP, IPPROTO_DCCP, net); 1073 } 1074 1075 static void __net_exit dccp_v6_exit_net(struct net *net) 1076 { 1077 inet_ctl_sock_destroy(net->dccp.v6_ctl_sk); 1078 } 1079 1080 static struct pernet_operations dccp_v6_ops = { 1081 .init = dccp_v6_init_net, 1082 .exit = dccp_v6_exit_net, 1083 }; 1084 1085 static int __init dccp_v6_init(void) 1086 { 1087 int err = proto_register(&dccp_v6_prot, 1); 1088 1089 if (err != 0) 1090 goto out; 1091 1092 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP); 1093 if (err != 0) 1094 goto out_unregister_proto; 1095 1096 inet6_register_protosw(&dccp_v6_protosw); 1097 1098 err = register_pernet_subsys(&dccp_v6_ops); 1099 if (err != 0) 1100 goto out_destroy_ctl_sock; 1101 out: 1102 return err; 1103 1104 out_destroy_ctl_sock: 1105 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP); 1106 inet6_unregister_protosw(&dccp_v6_protosw); 1107 out_unregister_proto: 1108 proto_unregister(&dccp_v6_prot); 1109 goto out; 1110 } 1111 1112 static void __exit dccp_v6_exit(void) 1113 { 1114 unregister_pernet_subsys(&dccp_v6_ops); 1115 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP); 1116 inet6_unregister_protosw(&dccp_v6_protosw); 1117 proto_unregister(&dccp_v6_prot); 1118 } 1119 1120 module_init(dccp_v6_init); 1121 module_exit(dccp_v6_exit); 1122 1123 /* 1124 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33) 1125 * values directly, Also cover the case where the protocol is not specified, 1126 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP 1127 */ 1128 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6); 1129 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6); 1130 MODULE_LICENSE("GPL"); 1131 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>"); 1132 MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol"); 1133