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 if (!sock_owned_by_user(sk)) { 126 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); 127 128 if (dst) 129 dst->ops->redirect(dst, sk, skb); 130 } 131 goto out; 132 } 133 134 if (type == ICMPV6_PKT_TOOBIG) { 135 struct dst_entry *dst = NULL; 136 137 if (!ip6_sk_accept_pmtu(sk)) 138 goto out; 139 140 if (sock_owned_by_user(sk)) 141 goto out; 142 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED)) 143 goto out; 144 145 dst = inet6_csk_update_pmtu(sk, ntohl(info)); 146 if (!dst) 147 goto out; 148 149 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) 150 dccp_sync_mss(sk, dst_mtu(dst)); 151 goto out; 152 } 153 154 icmpv6_err_convert(type, code, &err); 155 156 /* Might be for an request_sock */ 157 switch (sk->sk_state) { 158 case DCCP_REQUESTING: 159 case DCCP_RESPOND: /* Cannot happen. 160 It can, it SYNs are crossed. --ANK */ 161 if (!sock_owned_by_user(sk)) { 162 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); 163 sk->sk_err = err; 164 /* 165 * Wake people up to see the error 166 * (see connect in sock.c) 167 */ 168 sk->sk_error_report(sk); 169 dccp_done(sk); 170 } else 171 sk->sk_err_soft = err; 172 goto out; 173 } 174 175 if (!sock_owned_by_user(sk) && np->recverr) { 176 sk->sk_err = err; 177 sk->sk_error_report(sk); 178 } else 179 sk->sk_err_soft = err; 180 181 out: 182 bh_unlock_sock(sk); 183 sock_put(sk); 184 } 185 186 187 static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req) 188 { 189 struct inet_request_sock *ireq = inet_rsk(req); 190 struct ipv6_pinfo *np = inet6_sk(sk); 191 struct sk_buff *skb; 192 struct in6_addr *final_p, final; 193 struct flowi6 fl6; 194 int err = -1; 195 struct dst_entry *dst; 196 197 memset(&fl6, 0, sizeof(fl6)); 198 fl6.flowi6_proto = IPPROTO_DCCP; 199 fl6.daddr = ireq->ir_v6_rmt_addr; 200 fl6.saddr = ireq->ir_v6_loc_addr; 201 fl6.flowlabel = 0; 202 fl6.flowi6_oif = ireq->ir_iif; 203 fl6.fl6_dport = ireq->ir_rmt_port; 204 fl6.fl6_sport = htons(ireq->ir_num); 205 security_req_classify_flow(req, flowi6_to_flowi(&fl6)); 206 207 208 rcu_read_lock(); 209 final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final); 210 rcu_read_unlock(); 211 212 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 213 if (IS_ERR(dst)) { 214 err = PTR_ERR(dst); 215 dst = NULL; 216 goto done; 217 } 218 219 skb = dccp_make_response(sk, dst, req); 220 if (skb != NULL) { 221 struct dccp_hdr *dh = dccp_hdr(skb); 222 struct ipv6_txoptions *opt; 223 224 dh->dccph_checksum = dccp_v6_csum_finish(skb, 225 &ireq->ir_v6_loc_addr, 226 &ireq->ir_v6_rmt_addr); 227 fl6.daddr = ireq->ir_v6_rmt_addr; 228 rcu_read_lock(); 229 opt = ireq->ipv6_opt; 230 if (!opt) 231 opt = rcu_dereference(np->opt); 232 err = ip6_xmit(sk, skb, &fl6, sk->sk_mark, opt, np->tclass); 233 rcu_read_unlock(); 234 err = net_xmit_eval(err); 235 } 236 237 done: 238 dst_release(dst); 239 return err; 240 } 241 242 static void dccp_v6_reqsk_destructor(struct request_sock *req) 243 { 244 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg); 245 kfree(inet_rsk(req)->ipv6_opt); 246 kfree_skb(inet_rsk(req)->pktopts); 247 } 248 249 static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb) 250 { 251 const struct ipv6hdr *rxip6h; 252 struct sk_buff *skb; 253 struct flowi6 fl6; 254 struct net *net = dev_net(skb_dst(rxskb)->dev); 255 struct sock *ctl_sk = net->dccp.v6_ctl_sk; 256 struct dst_entry *dst; 257 258 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET) 259 return; 260 261 if (!ipv6_unicast_destination(rxskb)) 262 return; 263 264 skb = dccp_ctl_make_reset(ctl_sk, rxskb); 265 if (skb == NULL) 266 return; 267 268 rxip6h = ipv6_hdr(rxskb); 269 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr, 270 &rxip6h->daddr); 271 272 memset(&fl6, 0, sizeof(fl6)); 273 fl6.daddr = rxip6h->saddr; 274 fl6.saddr = rxip6h->daddr; 275 276 fl6.flowi6_proto = IPPROTO_DCCP; 277 fl6.flowi6_oif = inet6_iif(rxskb); 278 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport; 279 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport; 280 security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6)); 281 282 /* sk = NULL, but it is safe for now. RST socket required. */ 283 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL); 284 if (!IS_ERR(dst)) { 285 skb_dst_set(skb, dst); 286 ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0); 287 DCCP_INC_STATS(DCCP_MIB_OUTSEGS); 288 DCCP_INC_STATS(DCCP_MIB_OUTRSTS); 289 return; 290 } 291 292 kfree_skb(skb); 293 } 294 295 static struct request_sock_ops dccp6_request_sock_ops = { 296 .family = AF_INET6, 297 .obj_size = sizeof(struct dccp6_request_sock), 298 .rtx_syn_ack = dccp_v6_send_response, 299 .send_ack = dccp_reqsk_send_ack, 300 .destructor = dccp_v6_reqsk_destructor, 301 .send_reset = dccp_v6_ctl_send_reset, 302 .syn_ack_timeout = dccp_syn_ack_timeout, 303 }; 304 305 static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb) 306 { 307 struct request_sock *req; 308 struct dccp_request_sock *dreq; 309 struct inet_request_sock *ireq; 310 struct ipv6_pinfo *np = inet6_sk(sk); 311 const __be32 service = dccp_hdr_request(skb)->dccph_req_service; 312 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); 313 314 if (skb->protocol == htons(ETH_P_IP)) 315 return dccp_v4_conn_request(sk, skb); 316 317 if (!ipv6_unicast_destination(skb)) 318 return 0; /* discard, don't send a reset here */ 319 320 if (dccp_bad_service_code(sk, service)) { 321 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE; 322 goto drop; 323 } 324 /* 325 * There are no SYN attacks on IPv6, yet... 326 */ 327 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY; 328 if (inet_csk_reqsk_queue_is_full(sk)) 329 goto drop; 330 331 if (sk_acceptq_is_full(sk)) 332 goto drop; 333 334 req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true); 335 if (req == NULL) 336 goto drop; 337 338 if (dccp_reqsk_init(req, dccp_sk(sk), skb)) 339 goto drop_and_free; 340 341 dreq = dccp_rsk(req); 342 if (dccp_parse_options(sk, dreq, skb)) 343 goto drop_and_free; 344 345 if (security_inet_conn_request(sk, skb, req)) 346 goto drop_and_free; 347 348 ireq = inet_rsk(req); 349 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; 350 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; 351 ireq->ireq_family = AF_INET6; 352 353 if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) || 354 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || 355 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) { 356 refcount_inc(&skb->users); 357 ireq->pktopts = skb; 358 } 359 ireq->ir_iif = sk->sk_bound_dev_if; 360 361 /* So that link locals have meaning */ 362 if (!sk->sk_bound_dev_if && 363 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) 364 ireq->ir_iif = inet6_iif(skb); 365 366 /* 367 * Step 3: Process LISTEN state 368 * 369 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie 370 * 371 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child(). 372 */ 373 dreq->dreq_isr = dcb->dccpd_seq; 374 dreq->dreq_gsr = dreq->dreq_isr; 375 dreq->dreq_iss = dccp_v6_init_sequence(skb); 376 dreq->dreq_gss = dreq->dreq_iss; 377 dreq->dreq_service = service; 378 379 if (dccp_v6_send_response(sk, req)) 380 goto drop_and_free; 381 382 inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT); 383 return 0; 384 385 drop_and_free: 386 reqsk_free(req); 387 drop: 388 __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS); 389 return -1; 390 } 391 392 static struct sock *dccp_v6_request_recv_sock(const struct sock *sk, 393 struct sk_buff *skb, 394 struct request_sock *req, 395 struct dst_entry *dst, 396 struct request_sock *req_unhash, 397 bool *own_req) 398 { 399 struct inet_request_sock *ireq = inet_rsk(req); 400 struct ipv6_pinfo *newnp; 401 const struct ipv6_pinfo *np = inet6_sk(sk); 402 struct ipv6_txoptions *opt; 403 struct inet_sock *newinet; 404 struct dccp6_sock *newdp6; 405 struct sock *newsk; 406 407 if (skb->protocol == htons(ETH_P_IP)) { 408 /* 409 * v6 mapped 410 */ 411 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst, 412 req_unhash, own_req); 413 if (newsk == NULL) 414 return NULL; 415 416 newdp6 = (struct dccp6_sock *)newsk; 417 newinet = inet_sk(newsk); 418 newinet->pinet6 = &newdp6->inet6; 419 newnp = inet6_sk(newsk); 420 421 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 422 423 newnp->saddr = newsk->sk_v6_rcv_saddr; 424 425 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped; 426 newsk->sk_backlog_rcv = dccp_v4_do_rcv; 427 newnp->pktoptions = NULL; 428 newnp->opt = NULL; 429 newnp->ipv6_mc_list = NULL; 430 newnp->ipv6_ac_list = NULL; 431 newnp->ipv6_fl_list = NULL; 432 newnp->mcast_oif = inet6_iif(skb); 433 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 434 435 /* 436 * No need to charge this sock to the relevant IPv6 refcnt debug socks count 437 * here, dccp_create_openreq_child now does this for us, see the comment in 438 * that function for the gory details. -acme 439 */ 440 441 /* It is tricky place. Until this moment IPv4 tcp 442 worked with IPv6 icsk.icsk_af_ops. 443 Sync it now. 444 */ 445 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); 446 447 return newsk; 448 } 449 450 451 if (sk_acceptq_is_full(sk)) 452 goto out_overflow; 453 454 if (!dst) { 455 struct flowi6 fl6; 456 457 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP); 458 if (!dst) 459 goto out; 460 } 461 462 newsk = dccp_create_openreq_child(sk, req, skb); 463 if (newsk == NULL) 464 goto out_nonewsk; 465 466 /* 467 * No need to charge this sock to the relevant IPv6 refcnt debug socks 468 * count here, dccp_create_openreq_child now does this for us, see the 469 * comment in that function for the gory details. -acme 470 */ 471 472 ip6_dst_store(newsk, dst, NULL, NULL); 473 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM | 474 NETIF_F_TSO); 475 newdp6 = (struct dccp6_sock *)newsk; 476 newinet = inet_sk(newsk); 477 newinet->pinet6 = &newdp6->inet6; 478 newnp = inet6_sk(newsk); 479 480 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 481 482 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; 483 newnp->saddr = ireq->ir_v6_loc_addr; 484 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; 485 newsk->sk_bound_dev_if = ireq->ir_iif; 486 487 /* Now IPv6 options... 488 489 First: no IPv4 options. 490 */ 491 newinet->inet_opt = NULL; 492 493 /* Clone RX bits */ 494 newnp->rxopt.all = np->rxopt.all; 495 496 newnp->ipv6_mc_list = NULL; 497 newnp->ipv6_ac_list = NULL; 498 newnp->ipv6_fl_list = NULL; 499 newnp->pktoptions = NULL; 500 newnp->opt = NULL; 501 newnp->mcast_oif = inet6_iif(skb); 502 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 503 504 /* 505 * Clone native IPv6 options from listening socket (if any) 506 * 507 * Yes, keeping reference count would be much more clever, but we make 508 * one more one thing there: reattach optmem to newsk. 509 */ 510 opt = ireq->ipv6_opt; 511 if (!opt) 512 opt = rcu_dereference(np->opt); 513 if (opt) { 514 opt = ipv6_dup_options(newsk, opt); 515 RCU_INIT_POINTER(newnp->opt, opt); 516 } 517 inet_csk(newsk)->icsk_ext_hdr_len = 0; 518 if (opt) 519 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen + 520 opt->opt_flen; 521 522 dccp_sync_mss(newsk, dst_mtu(dst)); 523 524 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; 525 newinet->inet_rcv_saddr = LOOPBACK4_IPV6; 526 527 if (__inet_inherit_port(sk, newsk) < 0) { 528 inet_csk_prepare_forced_close(newsk); 529 dccp_done(newsk); 530 goto out; 531 } 532 *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash)); 533 /* Clone pktoptions received with SYN, if we own the req */ 534 if (*own_req && ireq->pktopts) { 535 newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC); 536 consume_skb(ireq->pktopts); 537 ireq->pktopts = NULL; 538 if (newnp->pktoptions) 539 skb_set_owner_r(newnp->pktoptions, newsk); 540 } 541 542 return newsk; 543 544 out_overflow: 545 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); 546 out_nonewsk: 547 dst_release(dst); 548 out: 549 __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); 550 return NULL; 551 } 552 553 /* The socket must have it's spinlock held when we get 554 * here. 555 * 556 * We have a potential double-lock case here, so even when 557 * doing backlog processing we use the BH locking scheme. 558 * This is because we cannot sleep with the original spinlock 559 * held. 560 */ 561 static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 562 { 563 struct ipv6_pinfo *np = inet6_sk(sk); 564 struct sk_buff *opt_skb = NULL; 565 566 /* Imagine: socket is IPv6. IPv4 packet arrives, 567 goes to IPv4 receive handler and backlogged. 568 From backlog it always goes here. Kerboom... 569 Fortunately, dccp_rcv_established and rcv_established 570 handle them correctly, but it is not case with 571 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK 572 */ 573 574 if (skb->protocol == htons(ETH_P_IP)) 575 return dccp_v4_do_rcv(sk, skb); 576 577 if (sk_filter(sk, skb)) 578 goto discard; 579 580 /* 581 * socket locking is here for SMP purposes as backlog rcv is currently 582 * called with bh processing disabled. 583 */ 584 585 /* Do Stevens' IPV6_PKTOPTIONS. 586 587 Yes, guys, it is the only place in our code, where we 588 may make it not affecting IPv4. 589 The rest of code is protocol independent, 590 and I do not like idea to uglify IPv4. 591 592 Actually, all the idea behind IPV6_PKTOPTIONS 593 looks not very well thought. For now we latch 594 options, received in the last packet, enqueued 595 by tcp. Feel free to propose better solution. 596 --ANK (980728) 597 */ 598 if (np->rxopt.all) 599 /* 600 * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below 601 * (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example. 602 */ 603 opt_skb = skb_clone(skb, GFP_ATOMIC); 604 605 if (sk->sk_state == DCCP_OPEN) { /* Fast path */ 606 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len)) 607 goto reset; 608 if (opt_skb) { 609 /* XXX This is where we would goto ipv6_pktoptions. */ 610 __kfree_skb(opt_skb); 611 } 612 return 0; 613 } 614 615 /* 616 * Step 3: Process LISTEN state 617 * If S.state == LISTEN, 618 * If P.type == Request or P contains a valid Init Cookie option, 619 * (* Must scan the packet's options to check for Init 620 * Cookies. Only Init Cookies are processed here, 621 * however; other options are processed in Step 8. This 622 * scan need only be performed if the endpoint uses Init 623 * Cookies *) 624 * (* Generate a new socket and switch to that socket *) 625 * Set S := new socket for this port pair 626 * S.state = RESPOND 627 * Choose S.ISS (initial seqno) or set from Init Cookies 628 * Initialize S.GAR := S.ISS 629 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies 630 * Continue with S.state == RESPOND 631 * (* A Response packet will be generated in Step 11 *) 632 * Otherwise, 633 * Generate Reset(No Connection) unless P.type == Reset 634 * Drop packet and return 635 * 636 * NOTE: the check for the packet types is done in 637 * dccp_rcv_state_process 638 */ 639 640 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len)) 641 goto reset; 642 if (opt_skb) { 643 /* XXX This is where we would goto ipv6_pktoptions. */ 644 __kfree_skb(opt_skb); 645 } 646 return 0; 647 648 reset: 649 dccp_v6_ctl_send_reset(sk, skb); 650 discard: 651 if (opt_skb != NULL) 652 __kfree_skb(opt_skb); 653 kfree_skb(skb); 654 return 0; 655 } 656 657 static int dccp_v6_rcv(struct sk_buff *skb) 658 { 659 const struct dccp_hdr *dh; 660 bool refcounted; 661 struct sock *sk; 662 int min_cov; 663 664 /* Step 1: Check header basics */ 665 666 if (dccp_invalid_packet(skb)) 667 goto discard_it; 668 669 /* Step 1: If header checksum is incorrect, drop packet and return. */ 670 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr, 671 &ipv6_hdr(skb)->daddr)) { 672 DCCP_WARN("dropped packet with invalid checksum\n"); 673 goto discard_it; 674 } 675 676 dh = dccp_hdr(skb); 677 678 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh); 679 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type; 680 681 if (dccp_packet_without_ack(skb)) 682 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ; 683 else 684 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb); 685 686 lookup: 687 sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh), 688 dh->dccph_sport, dh->dccph_dport, 689 inet6_iif(skb), &refcounted); 690 if (!sk) { 691 dccp_pr_debug("failed to look up flow ID in table and " 692 "get corresponding socket\n"); 693 goto no_dccp_socket; 694 } 695 696 /* 697 * Step 2: 698 * ... or S.state == TIMEWAIT, 699 * Generate Reset(No Connection) unless P.type == Reset 700 * Drop packet and return 701 */ 702 if (sk->sk_state == DCCP_TIME_WAIT) { 703 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n"); 704 inet_twsk_put(inet_twsk(sk)); 705 goto no_dccp_socket; 706 } 707 708 if (sk->sk_state == DCCP_NEW_SYN_RECV) { 709 struct request_sock *req = inet_reqsk(sk); 710 struct sock *nsk; 711 712 sk = req->rsk_listener; 713 if (unlikely(sk->sk_state != DCCP_LISTEN)) { 714 inet_csk_reqsk_queue_drop_and_put(sk, req); 715 goto lookup; 716 } 717 sock_hold(sk); 718 refcounted = true; 719 nsk = dccp_check_req(sk, skb, req); 720 if (!nsk) { 721 reqsk_put(req); 722 goto discard_and_relse; 723 } 724 if (nsk == sk) { 725 reqsk_put(req); 726 } else if (dccp_child_process(sk, nsk, skb)) { 727 dccp_v6_ctl_send_reset(sk, skb); 728 goto discard_and_relse; 729 } else { 730 sock_put(sk); 731 return 0; 732 } 733 } 734 /* 735 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage 736 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted 737 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov 738 */ 739 min_cov = dccp_sk(sk)->dccps_pcrlen; 740 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) { 741 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n", 742 dh->dccph_cscov, min_cov); 743 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */ 744 goto discard_and_relse; 745 } 746 747 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 748 goto discard_and_relse; 749 750 return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4, 751 refcounted) ? -1 : 0; 752 753 no_dccp_socket: 754 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 755 goto discard_it; 756 /* 757 * Step 2: 758 * If no socket ... 759 * Generate Reset(No Connection) unless P.type == Reset 760 * Drop packet and return 761 */ 762 if (dh->dccph_type != DCCP_PKT_RESET) { 763 DCCP_SKB_CB(skb)->dccpd_reset_code = 764 DCCP_RESET_CODE_NO_CONNECTION; 765 dccp_v6_ctl_send_reset(sk, skb); 766 } 767 768 discard_it: 769 kfree_skb(skb); 770 return 0; 771 772 discard_and_relse: 773 if (refcounted) 774 sock_put(sk); 775 goto discard_it; 776 } 777 778 static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr, 779 int addr_len) 780 { 781 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr; 782 struct inet_connection_sock *icsk = inet_csk(sk); 783 struct inet_sock *inet = inet_sk(sk); 784 struct ipv6_pinfo *np = inet6_sk(sk); 785 struct dccp_sock *dp = dccp_sk(sk); 786 struct in6_addr *saddr = NULL, *final_p, final; 787 struct ipv6_txoptions *opt; 788 struct flowi6 fl6; 789 struct dst_entry *dst; 790 int addr_type; 791 int err; 792 793 dp->dccps_role = DCCP_ROLE_CLIENT; 794 795 if (addr_len < SIN6_LEN_RFC2133) 796 return -EINVAL; 797 798 if (usin->sin6_family != AF_INET6) 799 return -EAFNOSUPPORT; 800 801 memset(&fl6, 0, sizeof(fl6)); 802 803 if (np->sndflow) { 804 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK; 805 IP6_ECN_flow_init(fl6.flowlabel); 806 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) { 807 struct ip6_flowlabel *flowlabel; 808 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 809 if (flowlabel == NULL) 810 return -EINVAL; 811 fl6_sock_release(flowlabel); 812 } 813 } 814 /* 815 * connect() to INADDR_ANY means loopback (BSD'ism). 816 */ 817 if (ipv6_addr_any(&usin->sin6_addr)) 818 usin->sin6_addr.s6_addr[15] = 1; 819 820 addr_type = ipv6_addr_type(&usin->sin6_addr); 821 822 if (addr_type & IPV6_ADDR_MULTICAST) 823 return -ENETUNREACH; 824 825 if (addr_type & IPV6_ADDR_LINKLOCAL) { 826 if (addr_len >= sizeof(struct sockaddr_in6) && 827 usin->sin6_scope_id) { 828 /* If interface is set while binding, indices 829 * must coincide. 830 */ 831 if (sk->sk_bound_dev_if && 832 sk->sk_bound_dev_if != usin->sin6_scope_id) 833 return -EINVAL; 834 835 sk->sk_bound_dev_if = usin->sin6_scope_id; 836 } 837 838 /* Connect to link-local address requires an interface */ 839 if (!sk->sk_bound_dev_if) 840 return -EINVAL; 841 } 842 843 sk->sk_v6_daddr = usin->sin6_addr; 844 np->flow_label = fl6.flowlabel; 845 846 /* 847 * DCCP over IPv4 848 */ 849 if (addr_type == IPV6_ADDR_MAPPED) { 850 u32 exthdrlen = icsk->icsk_ext_hdr_len; 851 struct sockaddr_in sin; 852 853 SOCK_DEBUG(sk, "connect: ipv4 mapped\n"); 854 855 if (__ipv6_only_sock(sk)) 856 return -ENETUNREACH; 857 858 sin.sin_family = AF_INET; 859 sin.sin_port = usin->sin6_port; 860 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; 861 862 icsk->icsk_af_ops = &dccp_ipv6_mapped; 863 sk->sk_backlog_rcv = dccp_v4_do_rcv; 864 865 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); 866 if (err) { 867 icsk->icsk_ext_hdr_len = exthdrlen; 868 icsk->icsk_af_ops = &dccp_ipv6_af_ops; 869 sk->sk_backlog_rcv = dccp_v6_do_rcv; 870 goto failure; 871 } 872 np->saddr = sk->sk_v6_rcv_saddr; 873 return err; 874 } 875 876 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 877 saddr = &sk->sk_v6_rcv_saddr; 878 879 fl6.flowi6_proto = IPPROTO_DCCP; 880 fl6.daddr = sk->sk_v6_daddr; 881 fl6.saddr = saddr ? *saddr : np->saddr; 882 fl6.flowi6_oif = sk->sk_bound_dev_if; 883 fl6.fl6_dport = usin->sin6_port; 884 fl6.fl6_sport = inet->inet_sport; 885 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 886 887 opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk)); 888 final_p = fl6_update_dst(&fl6, opt, &final); 889 890 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 891 if (IS_ERR(dst)) { 892 err = PTR_ERR(dst); 893 goto failure; 894 } 895 896 if (saddr == NULL) { 897 saddr = &fl6.saddr; 898 sk->sk_v6_rcv_saddr = *saddr; 899 } 900 901 /* set the source address */ 902 np->saddr = *saddr; 903 inet->inet_rcv_saddr = LOOPBACK4_IPV6; 904 905 ip6_dst_store(sk, dst, NULL, NULL); 906 907 icsk->icsk_ext_hdr_len = 0; 908 if (opt) 909 icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen; 910 911 inet->inet_dport = usin->sin6_port; 912 913 dccp_set_state(sk, DCCP_REQUESTING); 914 err = inet6_hash_connect(&dccp_death_row, sk); 915 if (err) 916 goto late_failure; 917 918 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32, 919 sk->sk_v6_daddr.s6_addr32, 920 inet->inet_sport, 921 inet->inet_dport); 922 err = dccp_connect(sk); 923 if (err) 924 goto late_failure; 925 926 return 0; 927 928 late_failure: 929 dccp_set_state(sk, DCCP_CLOSED); 930 __sk_dst_reset(sk); 931 failure: 932 inet->inet_dport = 0; 933 sk->sk_route_caps = 0; 934 return err; 935 } 936 937 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = { 938 .queue_xmit = inet6_csk_xmit, 939 .send_check = dccp_v6_send_check, 940 .rebuild_header = inet6_sk_rebuild_header, 941 .conn_request = dccp_v6_conn_request, 942 .syn_recv_sock = dccp_v6_request_recv_sock, 943 .net_header_len = sizeof(struct ipv6hdr), 944 .setsockopt = ipv6_setsockopt, 945 .getsockopt = ipv6_getsockopt, 946 .addr2sockaddr = inet6_csk_addr2sockaddr, 947 .sockaddr_len = sizeof(struct sockaddr_in6), 948 #ifdef CONFIG_COMPAT 949 .compat_setsockopt = compat_ipv6_setsockopt, 950 .compat_getsockopt = compat_ipv6_getsockopt, 951 #endif 952 }; 953 954 /* 955 * DCCP over IPv4 via INET6 API 956 */ 957 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = { 958 .queue_xmit = ip_queue_xmit, 959 .send_check = dccp_v4_send_check, 960 .rebuild_header = inet_sk_rebuild_header, 961 .conn_request = dccp_v6_conn_request, 962 .syn_recv_sock = dccp_v6_request_recv_sock, 963 .net_header_len = sizeof(struct iphdr), 964 .setsockopt = ipv6_setsockopt, 965 .getsockopt = ipv6_getsockopt, 966 .addr2sockaddr = inet6_csk_addr2sockaddr, 967 .sockaddr_len = sizeof(struct sockaddr_in6), 968 #ifdef CONFIG_COMPAT 969 .compat_setsockopt = compat_ipv6_setsockopt, 970 .compat_getsockopt = compat_ipv6_getsockopt, 971 #endif 972 }; 973 974 /* NOTE: A lot of things set to zero explicitly by call to 975 * sk_alloc() so need not be done here. 976 */ 977 static int dccp_v6_init_sock(struct sock *sk) 978 { 979 static __u8 dccp_v6_ctl_sock_initialized; 980 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized); 981 982 if (err == 0) { 983 if (unlikely(!dccp_v6_ctl_sock_initialized)) 984 dccp_v6_ctl_sock_initialized = 1; 985 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops; 986 } 987 988 return err; 989 } 990 991 static void dccp_v6_destroy_sock(struct sock *sk) 992 { 993 dccp_destroy_sock(sk); 994 inet6_destroy_sock(sk); 995 } 996 997 static struct timewait_sock_ops dccp6_timewait_sock_ops = { 998 .twsk_obj_size = sizeof(struct dccp6_timewait_sock), 999 }; 1000 1001 static struct proto dccp_v6_prot = { 1002 .name = "DCCPv6", 1003 .owner = THIS_MODULE, 1004 .close = dccp_close, 1005 .connect = dccp_v6_connect, 1006 .disconnect = dccp_disconnect, 1007 .ioctl = dccp_ioctl, 1008 .init = dccp_v6_init_sock, 1009 .setsockopt = dccp_setsockopt, 1010 .getsockopt = dccp_getsockopt, 1011 .sendmsg = dccp_sendmsg, 1012 .recvmsg = dccp_recvmsg, 1013 .backlog_rcv = dccp_v6_do_rcv, 1014 .hash = inet6_hash, 1015 .unhash = inet_unhash, 1016 .accept = inet_csk_accept, 1017 .get_port = inet_csk_get_port, 1018 .shutdown = dccp_shutdown, 1019 .destroy = dccp_v6_destroy_sock, 1020 .orphan_count = &dccp_orphan_count, 1021 .max_header = MAX_DCCP_HEADER, 1022 .obj_size = sizeof(struct dccp6_sock), 1023 .slab_flags = SLAB_TYPESAFE_BY_RCU, 1024 .rsk_prot = &dccp6_request_sock_ops, 1025 .twsk_prot = &dccp6_timewait_sock_ops, 1026 .h.hashinfo = &dccp_hashinfo, 1027 #ifdef CONFIG_COMPAT 1028 .compat_setsockopt = compat_dccp_setsockopt, 1029 .compat_getsockopt = compat_dccp_getsockopt, 1030 #endif 1031 }; 1032 1033 static const struct inet6_protocol dccp_v6_protocol = { 1034 .handler = dccp_v6_rcv, 1035 .err_handler = dccp_v6_err, 1036 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1037 }; 1038 1039 static const struct proto_ops inet6_dccp_ops = { 1040 .family = PF_INET6, 1041 .owner = THIS_MODULE, 1042 .release = inet6_release, 1043 .bind = inet6_bind, 1044 .connect = inet_stream_connect, 1045 .socketpair = sock_no_socketpair, 1046 .accept = inet_accept, 1047 .getname = inet6_getname, 1048 .poll = dccp_poll, 1049 .ioctl = inet6_ioctl, 1050 .listen = inet_dccp_listen, 1051 .shutdown = inet_shutdown, 1052 .setsockopt = sock_common_setsockopt, 1053 .getsockopt = sock_common_getsockopt, 1054 .sendmsg = inet_sendmsg, 1055 .recvmsg = sock_common_recvmsg, 1056 .mmap = sock_no_mmap, 1057 .sendpage = sock_no_sendpage, 1058 #ifdef CONFIG_COMPAT 1059 .compat_setsockopt = compat_sock_common_setsockopt, 1060 .compat_getsockopt = compat_sock_common_getsockopt, 1061 #endif 1062 }; 1063 1064 static struct inet_protosw dccp_v6_protosw = { 1065 .type = SOCK_DCCP, 1066 .protocol = IPPROTO_DCCP, 1067 .prot = &dccp_v6_prot, 1068 .ops = &inet6_dccp_ops, 1069 .flags = INET_PROTOSW_ICSK, 1070 }; 1071 1072 static int __net_init dccp_v6_init_net(struct net *net) 1073 { 1074 if (dccp_hashinfo.bhash == NULL) 1075 return -ESOCKTNOSUPPORT; 1076 1077 return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6, 1078 SOCK_DCCP, IPPROTO_DCCP, net); 1079 } 1080 1081 static void __net_exit dccp_v6_exit_net(struct net *net) 1082 { 1083 inet_ctl_sock_destroy(net->dccp.v6_ctl_sk); 1084 } 1085 1086 static void __net_exit dccp_v6_exit_batch(struct list_head *net_exit_list) 1087 { 1088 inet_twsk_purge(&dccp_hashinfo, AF_INET6); 1089 } 1090 1091 static struct pernet_operations dccp_v6_ops = { 1092 .init = dccp_v6_init_net, 1093 .exit = dccp_v6_exit_net, 1094 .exit_batch = dccp_v6_exit_batch, 1095 }; 1096 1097 static int __init dccp_v6_init(void) 1098 { 1099 int err = proto_register(&dccp_v6_prot, 1); 1100 1101 if (err) 1102 goto out; 1103 1104 inet6_register_protosw(&dccp_v6_protosw); 1105 1106 err = register_pernet_subsys(&dccp_v6_ops); 1107 if (err) 1108 goto out_destroy_ctl_sock; 1109 1110 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP); 1111 if (err) 1112 goto out_unregister_proto; 1113 1114 out: 1115 return err; 1116 out_unregister_proto: 1117 unregister_pernet_subsys(&dccp_v6_ops); 1118 out_destroy_ctl_sock: 1119 inet6_unregister_protosw(&dccp_v6_protosw); 1120 proto_unregister(&dccp_v6_prot); 1121 goto out; 1122 } 1123 1124 static void __exit dccp_v6_exit(void) 1125 { 1126 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP); 1127 unregister_pernet_subsys(&dccp_v6_ops); 1128 inet6_unregister_protosw(&dccp_v6_protosw); 1129 proto_unregister(&dccp_v6_prot); 1130 } 1131 1132 module_init(dccp_v6_init); 1133 module_exit(dccp_v6_exit); 1134 1135 /* 1136 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33) 1137 * values directly, Also cover the case where the protocol is not specified, 1138 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP 1139 */ 1140 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6); 1141 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6); 1142 MODULE_LICENSE("GPL"); 1143 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>"); 1144 MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol"); 1145