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 static void dccp_v6_hash(struct sock *sk) 44 { 45 if (sk->sk_state != DCCP_CLOSED) { 46 if (inet_csk(sk)->icsk_af_ops == &dccp_ipv6_mapped) { 47 inet_hash(sk); 48 return; 49 } 50 local_bh_disable(); 51 __inet6_hash(sk, NULL); 52 local_bh_enable(); 53 } 54 } 55 56 /* add pseudo-header to DCCP checksum stored in skb->csum */ 57 static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb, 58 const struct in6_addr *saddr, 59 const struct in6_addr *daddr) 60 { 61 return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum); 62 } 63 64 static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb) 65 { 66 struct ipv6_pinfo *np = inet6_sk(sk); 67 struct dccp_hdr *dh = dccp_hdr(skb); 68 69 dccp_csum_outgoing(skb); 70 dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr); 71 } 72 73 static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb) 74 { 75 return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32, 76 ipv6_hdr(skb)->saddr.s6_addr32, 77 dccp_hdr(skb)->dccph_dport, 78 dccp_hdr(skb)->dccph_sport ); 79 80 } 81 82 static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 83 u8 type, u8 code, int offset, __be32 info) 84 { 85 const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; 86 const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset); 87 struct dccp_sock *dp; 88 struct ipv6_pinfo *np; 89 struct sock *sk; 90 int err; 91 __u64 seq; 92 struct net *net = dev_net(skb->dev); 93 94 if (skb->len < offset + sizeof(*dh) || 95 skb->len < offset + __dccp_basic_hdr_len(dh)) { 96 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev), 97 ICMP6_MIB_INERRORS); 98 return; 99 } 100 101 sk = inet6_lookup(net, &dccp_hashinfo, 102 &hdr->daddr, dh->dccph_dport, 103 &hdr->saddr, dh->dccph_sport, inet6_iif(skb)); 104 105 if (sk == NULL) { 106 ICMP6_INC_STATS_BH(net, __in6_dev_get(skb->dev), 107 ICMP6_MIB_INERRORS); 108 return; 109 } 110 111 if (sk->sk_state == DCCP_TIME_WAIT) { 112 inet_twsk_put(inet_twsk(sk)); 113 return; 114 } 115 116 bh_lock_sock(sk); 117 if (sock_owned_by_user(sk)) 118 NET_INC_STATS_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); 119 120 if (sk->sk_state == DCCP_CLOSED) 121 goto out; 122 123 dp = dccp_sk(sk); 124 seq = dccp_hdr_seq(dh); 125 if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) && 126 !between48(seq, dp->dccps_awl, dp->dccps_awh)) { 127 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); 128 goto out; 129 } 130 131 np = inet6_sk(sk); 132 133 if (type == NDISC_REDIRECT) { 134 struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); 135 136 if (dst) 137 dst->ops->redirect(dst, sk, skb); 138 goto out; 139 } 140 141 if (type == ICMPV6_PKT_TOOBIG) { 142 struct dst_entry *dst = NULL; 143 144 if (!ip6_sk_accept_pmtu(sk)) 145 goto out; 146 147 if (sock_owned_by_user(sk)) 148 goto out; 149 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED)) 150 goto out; 151 152 dst = inet6_csk_update_pmtu(sk, ntohl(info)); 153 if (!dst) 154 goto out; 155 156 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) 157 dccp_sync_mss(sk, dst_mtu(dst)); 158 goto out; 159 } 160 161 icmpv6_err_convert(type, code, &err); 162 163 /* Might be for an request_sock */ 164 switch (sk->sk_state) { 165 struct request_sock *req, **prev; 166 case DCCP_LISTEN: 167 if (sock_owned_by_user(sk)) 168 goto out; 169 170 req = inet6_csk_search_req(sk, &prev, dh->dccph_dport, 171 &hdr->daddr, &hdr->saddr, 172 inet6_iif(skb)); 173 if (req == NULL) 174 goto out; 175 176 /* 177 * ICMPs are not backlogged, hence we cannot get an established 178 * socket here. 179 */ 180 WARN_ON(req->sk != NULL); 181 182 if (!between48(seq, dccp_rsk(req)->dreq_iss, 183 dccp_rsk(req)->dreq_gss)) { 184 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); 185 goto out; 186 } 187 188 inet_csk_reqsk_queue_drop(sk, req, prev); 189 goto out; 190 191 case DCCP_REQUESTING: 192 case DCCP_RESPOND: /* Cannot happen. 193 It can, it SYNs are crossed. --ANK */ 194 if (!sock_owned_by_user(sk)) { 195 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS); 196 sk->sk_err = err; 197 /* 198 * Wake people up to see the error 199 * (see connect in sock.c) 200 */ 201 sk->sk_error_report(sk); 202 dccp_done(sk); 203 } else 204 sk->sk_err_soft = err; 205 goto out; 206 } 207 208 if (!sock_owned_by_user(sk) && np->recverr) { 209 sk->sk_err = err; 210 sk->sk_error_report(sk); 211 } else 212 sk->sk_err_soft = err; 213 214 out: 215 bh_unlock_sock(sk); 216 sock_put(sk); 217 } 218 219 220 static int dccp_v6_send_response(struct sock *sk, struct request_sock *req) 221 { 222 struct inet_request_sock *ireq = inet_rsk(req); 223 struct ipv6_pinfo *np = inet6_sk(sk); 224 struct sk_buff *skb; 225 struct in6_addr *final_p, final; 226 struct flowi6 fl6; 227 int err = -1; 228 struct dst_entry *dst; 229 230 memset(&fl6, 0, sizeof(fl6)); 231 fl6.flowi6_proto = IPPROTO_DCCP; 232 fl6.daddr = ireq->ir_v6_rmt_addr; 233 fl6.saddr = ireq->ir_v6_loc_addr; 234 fl6.flowlabel = 0; 235 fl6.flowi6_oif = ireq->ir_iif; 236 fl6.fl6_dport = ireq->ir_rmt_port; 237 fl6.fl6_sport = htons(ireq->ir_num); 238 security_req_classify_flow(req, flowi6_to_flowi(&fl6)); 239 240 241 final_p = fl6_update_dst(&fl6, np->opt, &final); 242 243 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 244 if (IS_ERR(dst)) { 245 err = PTR_ERR(dst); 246 dst = NULL; 247 goto done; 248 } 249 250 skb = dccp_make_response(sk, dst, req); 251 if (skb != NULL) { 252 struct dccp_hdr *dh = dccp_hdr(skb); 253 254 dh->dccph_checksum = dccp_v6_csum_finish(skb, 255 &ireq->ir_v6_loc_addr, 256 &ireq->ir_v6_rmt_addr); 257 fl6.daddr = ireq->ir_v6_rmt_addr; 258 err = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass); 259 err = net_xmit_eval(err); 260 } 261 262 done: 263 dst_release(dst); 264 return err; 265 } 266 267 static void dccp_v6_reqsk_destructor(struct request_sock *req) 268 { 269 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg); 270 kfree_skb(inet_rsk(req)->pktopts); 271 } 272 273 static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb) 274 { 275 const struct ipv6hdr *rxip6h; 276 struct sk_buff *skb; 277 struct flowi6 fl6; 278 struct net *net = dev_net(skb_dst(rxskb)->dev); 279 struct sock *ctl_sk = net->dccp.v6_ctl_sk; 280 struct dst_entry *dst; 281 282 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET) 283 return; 284 285 if (!ipv6_unicast_destination(rxskb)) 286 return; 287 288 skb = dccp_ctl_make_reset(ctl_sk, rxskb); 289 if (skb == NULL) 290 return; 291 292 rxip6h = ipv6_hdr(rxskb); 293 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr, 294 &rxip6h->daddr); 295 296 memset(&fl6, 0, sizeof(fl6)); 297 fl6.daddr = rxip6h->saddr; 298 fl6.saddr = rxip6h->daddr; 299 300 fl6.flowi6_proto = IPPROTO_DCCP; 301 fl6.flowi6_oif = inet6_iif(rxskb); 302 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport; 303 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport; 304 security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6)); 305 306 /* sk = NULL, but it is safe for now. RST socket required. */ 307 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL); 308 if (!IS_ERR(dst)) { 309 skb_dst_set(skb, dst); 310 ip6_xmit(ctl_sk, skb, &fl6, NULL, 0); 311 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS); 312 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS); 313 return; 314 } 315 316 kfree_skb(skb); 317 } 318 319 static struct request_sock_ops dccp6_request_sock_ops = { 320 .family = AF_INET6, 321 .obj_size = sizeof(struct dccp6_request_sock), 322 .rtx_syn_ack = dccp_v6_send_response, 323 .send_ack = dccp_reqsk_send_ack, 324 .destructor = dccp_v6_reqsk_destructor, 325 .send_reset = dccp_v6_ctl_send_reset, 326 .syn_ack_timeout = dccp_syn_ack_timeout, 327 }; 328 329 static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb) 330 { 331 const struct dccp_hdr *dh = dccp_hdr(skb); 332 const struct ipv6hdr *iph = ipv6_hdr(skb); 333 struct sock *nsk; 334 struct request_sock **prev; 335 /* Find possible connection requests. */ 336 struct request_sock *req = inet6_csk_search_req(sk, &prev, 337 dh->dccph_sport, 338 &iph->saddr, 339 &iph->daddr, 340 inet6_iif(skb)); 341 if (req != NULL) 342 return dccp_check_req(sk, skb, req, prev); 343 344 nsk = __inet6_lookup_established(sock_net(sk), &dccp_hashinfo, 345 &iph->saddr, dh->dccph_sport, 346 &iph->daddr, ntohs(dh->dccph_dport), 347 inet6_iif(skb)); 348 if (nsk != NULL) { 349 if (nsk->sk_state != DCCP_TIME_WAIT) { 350 bh_lock_sock(nsk); 351 return nsk; 352 } 353 inet_twsk_put(inet_twsk(nsk)); 354 return NULL; 355 } 356 357 return sk; 358 } 359 360 static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb) 361 { 362 struct request_sock *req; 363 struct dccp_request_sock *dreq; 364 struct inet_request_sock *ireq; 365 struct ipv6_pinfo *np = inet6_sk(sk); 366 const __be32 service = dccp_hdr_request(skb)->dccph_req_service; 367 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); 368 369 if (skb->protocol == htons(ETH_P_IP)) 370 return dccp_v4_conn_request(sk, skb); 371 372 if (!ipv6_unicast_destination(skb)) 373 return 0; /* discard, don't send a reset here */ 374 375 if (dccp_bad_service_code(sk, service)) { 376 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE; 377 goto drop; 378 } 379 /* 380 * There are no SYN attacks on IPv6, yet... 381 */ 382 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY; 383 if (inet_csk_reqsk_queue_is_full(sk)) 384 goto drop; 385 386 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) 387 goto drop; 388 389 req = inet_reqsk_alloc(&dccp6_request_sock_ops); 390 if (req == NULL) 391 goto drop; 392 393 if (dccp_reqsk_init(req, dccp_sk(sk), skb)) 394 goto drop_and_free; 395 396 dreq = dccp_rsk(req); 397 if (dccp_parse_options(sk, dreq, skb)) 398 goto drop_and_free; 399 400 if (security_inet_conn_request(sk, skb, req)) 401 goto drop_and_free; 402 403 ireq = inet_rsk(req); 404 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; 405 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; 406 407 if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) || 408 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || 409 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) { 410 atomic_inc(&skb->users); 411 ireq->pktopts = skb; 412 } 413 ireq->ir_iif = sk->sk_bound_dev_if; 414 415 /* So that link locals have meaning */ 416 if (!sk->sk_bound_dev_if && 417 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) 418 ireq->ir_iif = inet6_iif(skb); 419 420 /* 421 * Step 3: Process LISTEN state 422 * 423 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie 424 * 425 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child(). 426 */ 427 dreq->dreq_isr = dcb->dccpd_seq; 428 dreq->dreq_gsr = dreq->dreq_isr; 429 dreq->dreq_iss = dccp_v6_init_sequence(skb); 430 dreq->dreq_gss = dreq->dreq_iss; 431 dreq->dreq_service = service; 432 433 if (dccp_v6_send_response(sk, req)) 434 goto drop_and_free; 435 436 inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT); 437 return 0; 438 439 drop_and_free: 440 reqsk_free(req); 441 drop: 442 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS); 443 return -1; 444 } 445 446 static struct sock *dccp_v6_request_recv_sock(struct sock *sk, 447 struct sk_buff *skb, 448 struct request_sock *req, 449 struct dst_entry *dst) 450 { 451 struct inet_request_sock *ireq = inet_rsk(req); 452 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 453 struct inet_sock *newinet; 454 struct dccp6_sock *newdp6; 455 struct sock *newsk; 456 457 if (skb->protocol == htons(ETH_P_IP)) { 458 /* 459 * v6 mapped 460 */ 461 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst); 462 if (newsk == NULL) 463 return NULL; 464 465 newdp6 = (struct dccp6_sock *)newsk; 466 newinet = inet_sk(newsk); 467 newinet->pinet6 = &newdp6->inet6; 468 newnp = inet6_sk(newsk); 469 470 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 471 472 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newsk->sk_v6_daddr); 473 474 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr); 475 476 newsk->sk_v6_rcv_saddr = newnp->saddr; 477 478 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped; 479 newsk->sk_backlog_rcv = dccp_v4_do_rcv; 480 newnp->pktoptions = NULL; 481 newnp->opt = NULL; 482 newnp->mcast_oif = inet6_iif(skb); 483 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 484 485 /* 486 * No need to charge this sock to the relevant IPv6 refcnt debug socks count 487 * here, dccp_create_openreq_child now does this for us, see the comment in 488 * that function for the gory details. -acme 489 */ 490 491 /* It is tricky place. Until this moment IPv4 tcp 492 worked with IPv6 icsk.icsk_af_ops. 493 Sync it now. 494 */ 495 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); 496 497 return newsk; 498 } 499 500 501 if (sk_acceptq_is_full(sk)) 502 goto out_overflow; 503 504 if (dst == NULL) { 505 struct in6_addr *final_p, final; 506 struct flowi6 fl6; 507 508 memset(&fl6, 0, sizeof(fl6)); 509 fl6.flowi6_proto = IPPROTO_DCCP; 510 fl6.daddr = ireq->ir_v6_rmt_addr; 511 final_p = fl6_update_dst(&fl6, np->opt, &final); 512 fl6.saddr = ireq->ir_v6_loc_addr; 513 fl6.flowi6_oif = sk->sk_bound_dev_if; 514 fl6.fl6_dport = ireq->ir_rmt_port; 515 fl6.fl6_sport = htons(ireq->ir_num); 516 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 517 518 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 519 if (IS_ERR(dst)) 520 goto out; 521 } 522 523 newsk = dccp_create_openreq_child(sk, req, skb); 524 if (newsk == NULL) 525 goto out_nonewsk; 526 527 /* 528 * No need to charge this sock to the relevant IPv6 refcnt debug socks 529 * count here, dccp_create_openreq_child now does this for us, see the 530 * comment in that function for the gory details. -acme 531 */ 532 533 __ip6_dst_store(newsk, dst, NULL, NULL); 534 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM | 535 NETIF_F_TSO); 536 newdp6 = (struct dccp6_sock *)newsk; 537 newinet = inet_sk(newsk); 538 newinet->pinet6 = &newdp6->inet6; 539 newnp = inet6_sk(newsk); 540 541 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 542 543 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; 544 newnp->saddr = ireq->ir_v6_loc_addr; 545 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; 546 newsk->sk_bound_dev_if = ireq->ir_iif; 547 548 /* Now IPv6 options... 549 550 First: no IPv4 options. 551 */ 552 newinet->inet_opt = NULL; 553 554 /* Clone RX bits */ 555 newnp->rxopt.all = np->rxopt.all; 556 557 /* Clone pktoptions received with SYN */ 558 newnp->pktoptions = NULL; 559 if (ireq->pktopts != NULL) { 560 newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC); 561 consume_skb(ireq->pktopts); 562 ireq->pktopts = NULL; 563 if (newnp->pktoptions) 564 skb_set_owner_r(newnp->pktoptions, newsk); 565 } 566 newnp->opt = NULL; 567 newnp->mcast_oif = inet6_iif(skb); 568 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 569 570 /* 571 * Clone native IPv6 options from listening socket (if any) 572 * 573 * Yes, keeping reference count would be much more clever, but we make 574 * one more one thing there: reattach optmem to newsk. 575 */ 576 if (np->opt != NULL) 577 newnp->opt = ipv6_dup_options(newsk, np->opt); 578 579 inet_csk(newsk)->icsk_ext_hdr_len = 0; 580 if (newnp->opt != NULL) 581 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen + 582 newnp->opt->opt_flen); 583 584 dccp_sync_mss(newsk, dst_mtu(dst)); 585 586 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; 587 newinet->inet_rcv_saddr = LOOPBACK4_IPV6; 588 589 if (__inet_inherit_port(sk, newsk) < 0) { 590 inet_csk_prepare_forced_close(newsk); 591 dccp_done(newsk); 592 goto out; 593 } 594 __inet6_hash(newsk, NULL); 595 596 return newsk; 597 598 out_overflow: 599 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); 600 out_nonewsk: 601 dst_release(dst); 602 out: 603 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); 604 return NULL; 605 } 606 607 /* The socket must have it's spinlock held when we get 608 * here. 609 * 610 * We have a potential double-lock case here, so even when 611 * doing backlog processing we use the BH locking scheme. 612 * This is because we cannot sleep with the original spinlock 613 * held. 614 */ 615 static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 616 { 617 struct ipv6_pinfo *np = inet6_sk(sk); 618 struct sk_buff *opt_skb = NULL; 619 620 /* Imagine: socket is IPv6. IPv4 packet arrives, 621 goes to IPv4 receive handler and backlogged. 622 From backlog it always goes here. Kerboom... 623 Fortunately, dccp_rcv_established and rcv_established 624 handle them correctly, but it is not case with 625 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK 626 */ 627 628 if (skb->protocol == htons(ETH_P_IP)) 629 return dccp_v4_do_rcv(sk, skb); 630 631 if (sk_filter(sk, skb)) 632 goto discard; 633 634 /* 635 * socket locking is here for SMP purposes as backlog rcv is currently 636 * called with bh processing disabled. 637 */ 638 639 /* Do Stevens' IPV6_PKTOPTIONS. 640 641 Yes, guys, it is the only place in our code, where we 642 may make it not affecting IPv4. 643 The rest of code is protocol independent, 644 and I do not like idea to uglify IPv4. 645 646 Actually, all the idea behind IPV6_PKTOPTIONS 647 looks not very well thought. For now we latch 648 options, received in the last packet, enqueued 649 by tcp. Feel free to propose better solution. 650 --ANK (980728) 651 */ 652 if (np->rxopt.all) 653 /* 654 * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below 655 * (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example. 656 */ 657 opt_skb = skb_clone(skb, GFP_ATOMIC); 658 659 if (sk->sk_state == DCCP_OPEN) { /* Fast path */ 660 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len)) 661 goto reset; 662 if (opt_skb) { 663 /* XXX This is where we would goto ipv6_pktoptions. */ 664 __kfree_skb(opt_skb); 665 } 666 return 0; 667 } 668 669 /* 670 * Step 3: Process LISTEN state 671 * If S.state == LISTEN, 672 * If P.type == Request or P contains a valid Init Cookie option, 673 * (* Must scan the packet's options to check for Init 674 * Cookies. Only Init Cookies are processed here, 675 * however; other options are processed in Step 8. This 676 * scan need only be performed if the endpoint uses Init 677 * Cookies *) 678 * (* Generate a new socket and switch to that socket *) 679 * Set S := new socket for this port pair 680 * S.state = RESPOND 681 * Choose S.ISS (initial seqno) or set from Init Cookies 682 * Initialize S.GAR := S.ISS 683 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies 684 * Continue with S.state == RESPOND 685 * (* A Response packet will be generated in Step 11 *) 686 * Otherwise, 687 * Generate Reset(No Connection) unless P.type == Reset 688 * Drop packet and return 689 * 690 * NOTE: the check for the packet types is done in 691 * dccp_rcv_state_process 692 */ 693 if (sk->sk_state == DCCP_LISTEN) { 694 struct sock *nsk = dccp_v6_hnd_req(sk, skb); 695 696 if (nsk == NULL) 697 goto discard; 698 /* 699 * Queue it on the new socket if the new socket is active, 700 * otherwise we just shortcircuit this and continue with 701 * the new socket.. 702 */ 703 if (nsk != sk) { 704 if (dccp_child_process(sk, nsk, skb)) 705 goto reset; 706 if (opt_skb != NULL) 707 __kfree_skb(opt_skb); 708 return 0; 709 } 710 } 711 712 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len)) 713 goto reset; 714 if (opt_skb) { 715 /* XXX This is where we would goto ipv6_pktoptions. */ 716 __kfree_skb(opt_skb); 717 } 718 return 0; 719 720 reset: 721 dccp_v6_ctl_send_reset(sk, skb); 722 discard: 723 if (opt_skb != NULL) 724 __kfree_skb(opt_skb); 725 kfree_skb(skb); 726 return 0; 727 } 728 729 static int dccp_v6_rcv(struct sk_buff *skb) 730 { 731 const struct dccp_hdr *dh; 732 struct sock *sk; 733 int min_cov; 734 735 /* Step 1: Check header basics */ 736 737 if (dccp_invalid_packet(skb)) 738 goto discard_it; 739 740 /* Step 1: If header checksum is incorrect, drop packet and return. */ 741 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr, 742 &ipv6_hdr(skb)->daddr)) { 743 DCCP_WARN("dropped packet with invalid checksum\n"); 744 goto discard_it; 745 } 746 747 dh = dccp_hdr(skb); 748 749 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh); 750 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type; 751 752 if (dccp_packet_without_ack(skb)) 753 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ; 754 else 755 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb); 756 757 /* Step 2: 758 * Look up flow ID in table and get corresponding socket */ 759 sk = __inet6_lookup_skb(&dccp_hashinfo, skb, 760 dh->dccph_sport, dh->dccph_dport, 761 inet6_iif(skb)); 762 /* 763 * Step 2: 764 * If no socket ... 765 */ 766 if (sk == NULL) { 767 dccp_pr_debug("failed to look up flow ID in table and " 768 "get corresponding socket\n"); 769 goto no_dccp_socket; 770 } 771 772 /* 773 * Step 2: 774 * ... or S.state == TIMEWAIT, 775 * Generate Reset(No Connection) unless P.type == Reset 776 * Drop packet and return 777 */ 778 if (sk->sk_state == DCCP_TIME_WAIT) { 779 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n"); 780 inet_twsk_put(inet_twsk(sk)); 781 goto no_dccp_socket; 782 } 783 784 /* 785 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage 786 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted 787 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov 788 */ 789 min_cov = dccp_sk(sk)->dccps_pcrlen; 790 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) { 791 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n", 792 dh->dccph_cscov, min_cov); 793 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */ 794 goto discard_and_relse; 795 } 796 797 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 798 goto discard_and_relse; 799 800 return sk_receive_skb(sk, skb, 1) ? -1 : 0; 801 802 no_dccp_socket: 803 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 804 goto discard_it; 805 /* 806 * Step 2: 807 * If no socket ... 808 * Generate Reset(No Connection) unless P.type == Reset 809 * Drop packet and return 810 */ 811 if (dh->dccph_type != DCCP_PKT_RESET) { 812 DCCP_SKB_CB(skb)->dccpd_reset_code = 813 DCCP_RESET_CODE_NO_CONNECTION; 814 dccp_v6_ctl_send_reset(sk, skb); 815 } 816 817 discard_it: 818 kfree_skb(skb); 819 return 0; 820 821 discard_and_relse: 822 sock_put(sk); 823 goto discard_it; 824 } 825 826 static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr, 827 int addr_len) 828 { 829 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr; 830 struct inet_connection_sock *icsk = inet_csk(sk); 831 struct inet_sock *inet = inet_sk(sk); 832 struct ipv6_pinfo *np = inet6_sk(sk); 833 struct dccp_sock *dp = dccp_sk(sk); 834 struct in6_addr *saddr = NULL, *final_p, final; 835 struct flowi6 fl6; 836 struct dst_entry *dst; 837 int addr_type; 838 int err; 839 840 dp->dccps_role = DCCP_ROLE_CLIENT; 841 842 if (addr_len < SIN6_LEN_RFC2133) 843 return -EINVAL; 844 845 if (usin->sin6_family != AF_INET6) 846 return -EAFNOSUPPORT; 847 848 memset(&fl6, 0, sizeof(fl6)); 849 850 if (np->sndflow) { 851 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK; 852 IP6_ECN_flow_init(fl6.flowlabel); 853 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) { 854 struct ip6_flowlabel *flowlabel; 855 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 856 if (flowlabel == NULL) 857 return -EINVAL; 858 fl6_sock_release(flowlabel); 859 } 860 } 861 /* 862 * connect() to INADDR_ANY means loopback (BSD'ism). 863 */ 864 if (ipv6_addr_any(&usin->sin6_addr)) 865 usin->sin6_addr.s6_addr[15] = 1; 866 867 addr_type = ipv6_addr_type(&usin->sin6_addr); 868 869 if (addr_type & IPV6_ADDR_MULTICAST) 870 return -ENETUNREACH; 871 872 if (addr_type & IPV6_ADDR_LINKLOCAL) { 873 if (addr_len >= sizeof(struct sockaddr_in6) && 874 usin->sin6_scope_id) { 875 /* If interface is set while binding, indices 876 * must coincide. 877 */ 878 if (sk->sk_bound_dev_if && 879 sk->sk_bound_dev_if != usin->sin6_scope_id) 880 return -EINVAL; 881 882 sk->sk_bound_dev_if = usin->sin6_scope_id; 883 } 884 885 /* Connect to link-local address requires an interface */ 886 if (!sk->sk_bound_dev_if) 887 return -EINVAL; 888 } 889 890 sk->sk_v6_daddr = usin->sin6_addr; 891 np->flow_label = fl6.flowlabel; 892 893 /* 894 * DCCP over IPv4 895 */ 896 if (addr_type == IPV6_ADDR_MAPPED) { 897 u32 exthdrlen = icsk->icsk_ext_hdr_len; 898 struct sockaddr_in sin; 899 900 SOCK_DEBUG(sk, "connect: ipv4 mapped\n"); 901 902 if (__ipv6_only_sock(sk)) 903 return -ENETUNREACH; 904 905 sin.sin_family = AF_INET; 906 sin.sin_port = usin->sin6_port; 907 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; 908 909 icsk->icsk_af_ops = &dccp_ipv6_mapped; 910 sk->sk_backlog_rcv = dccp_v4_do_rcv; 911 912 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); 913 if (err) { 914 icsk->icsk_ext_hdr_len = exthdrlen; 915 icsk->icsk_af_ops = &dccp_ipv6_af_ops; 916 sk->sk_backlog_rcv = dccp_v6_do_rcv; 917 goto failure; 918 } 919 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr); 920 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr, &sk->sk_v6_rcv_saddr); 921 922 return err; 923 } 924 925 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 926 saddr = &sk->sk_v6_rcv_saddr; 927 928 fl6.flowi6_proto = IPPROTO_DCCP; 929 fl6.daddr = sk->sk_v6_daddr; 930 fl6.saddr = saddr ? *saddr : np->saddr; 931 fl6.flowi6_oif = sk->sk_bound_dev_if; 932 fl6.fl6_dport = usin->sin6_port; 933 fl6.fl6_sport = inet->inet_sport; 934 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 935 936 final_p = fl6_update_dst(&fl6, np->opt, &final); 937 938 dst = ip6_dst_lookup_flow(sk, &fl6, final_p); 939 if (IS_ERR(dst)) { 940 err = PTR_ERR(dst); 941 goto failure; 942 } 943 944 if (saddr == NULL) { 945 saddr = &fl6.saddr; 946 sk->sk_v6_rcv_saddr = *saddr; 947 } 948 949 /* set the source address */ 950 np->saddr = *saddr; 951 inet->inet_rcv_saddr = LOOPBACK4_IPV6; 952 953 __ip6_dst_store(sk, dst, NULL, NULL); 954 955 icsk->icsk_ext_hdr_len = 0; 956 if (np->opt != NULL) 957 icsk->icsk_ext_hdr_len = (np->opt->opt_flen + 958 np->opt->opt_nflen); 959 960 inet->inet_dport = usin->sin6_port; 961 962 dccp_set_state(sk, DCCP_REQUESTING); 963 err = inet6_hash_connect(&dccp_death_row, sk); 964 if (err) 965 goto late_failure; 966 967 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32, 968 sk->sk_v6_daddr.s6_addr32, 969 inet->inet_sport, 970 inet->inet_dport); 971 err = dccp_connect(sk); 972 if (err) 973 goto late_failure; 974 975 return 0; 976 977 late_failure: 978 dccp_set_state(sk, DCCP_CLOSED); 979 __sk_dst_reset(sk); 980 failure: 981 inet->inet_dport = 0; 982 sk->sk_route_caps = 0; 983 return err; 984 } 985 986 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = { 987 .queue_xmit = inet6_csk_xmit, 988 .send_check = dccp_v6_send_check, 989 .rebuild_header = inet6_sk_rebuild_header, 990 .conn_request = dccp_v6_conn_request, 991 .syn_recv_sock = dccp_v6_request_recv_sock, 992 .net_header_len = sizeof(struct ipv6hdr), 993 .setsockopt = ipv6_setsockopt, 994 .getsockopt = ipv6_getsockopt, 995 .addr2sockaddr = inet6_csk_addr2sockaddr, 996 .sockaddr_len = sizeof(struct sockaddr_in6), 997 .bind_conflict = inet6_csk_bind_conflict, 998 #ifdef CONFIG_COMPAT 999 .compat_setsockopt = compat_ipv6_setsockopt, 1000 .compat_getsockopt = compat_ipv6_getsockopt, 1001 #endif 1002 }; 1003 1004 /* 1005 * DCCP over IPv4 via INET6 API 1006 */ 1007 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = { 1008 .queue_xmit = ip_queue_xmit, 1009 .send_check = dccp_v4_send_check, 1010 .rebuild_header = inet_sk_rebuild_header, 1011 .conn_request = dccp_v6_conn_request, 1012 .syn_recv_sock = dccp_v6_request_recv_sock, 1013 .net_header_len = sizeof(struct iphdr), 1014 .setsockopt = ipv6_setsockopt, 1015 .getsockopt = ipv6_getsockopt, 1016 .addr2sockaddr = inet6_csk_addr2sockaddr, 1017 .sockaddr_len = sizeof(struct sockaddr_in6), 1018 #ifdef CONFIG_COMPAT 1019 .compat_setsockopt = compat_ipv6_setsockopt, 1020 .compat_getsockopt = compat_ipv6_getsockopt, 1021 #endif 1022 }; 1023 1024 /* NOTE: A lot of things set to zero explicitly by call to 1025 * sk_alloc() so need not be done here. 1026 */ 1027 static int dccp_v6_init_sock(struct sock *sk) 1028 { 1029 static __u8 dccp_v6_ctl_sock_initialized; 1030 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized); 1031 1032 if (err == 0) { 1033 if (unlikely(!dccp_v6_ctl_sock_initialized)) 1034 dccp_v6_ctl_sock_initialized = 1; 1035 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops; 1036 } 1037 1038 return err; 1039 } 1040 1041 static void dccp_v6_destroy_sock(struct sock *sk) 1042 { 1043 dccp_destroy_sock(sk); 1044 inet6_destroy_sock(sk); 1045 } 1046 1047 static struct timewait_sock_ops dccp6_timewait_sock_ops = { 1048 .twsk_obj_size = sizeof(struct dccp6_timewait_sock), 1049 }; 1050 1051 static struct proto dccp_v6_prot = { 1052 .name = "DCCPv6", 1053 .owner = THIS_MODULE, 1054 .close = dccp_close, 1055 .connect = dccp_v6_connect, 1056 .disconnect = dccp_disconnect, 1057 .ioctl = dccp_ioctl, 1058 .init = dccp_v6_init_sock, 1059 .setsockopt = dccp_setsockopt, 1060 .getsockopt = dccp_getsockopt, 1061 .sendmsg = dccp_sendmsg, 1062 .recvmsg = dccp_recvmsg, 1063 .backlog_rcv = dccp_v6_do_rcv, 1064 .hash = dccp_v6_hash, 1065 .unhash = inet_unhash, 1066 .accept = inet_csk_accept, 1067 .get_port = inet_csk_get_port, 1068 .shutdown = dccp_shutdown, 1069 .destroy = dccp_v6_destroy_sock, 1070 .orphan_count = &dccp_orphan_count, 1071 .max_header = MAX_DCCP_HEADER, 1072 .obj_size = sizeof(struct dccp6_sock), 1073 .slab_flags = SLAB_DESTROY_BY_RCU, 1074 .rsk_prot = &dccp6_request_sock_ops, 1075 .twsk_prot = &dccp6_timewait_sock_ops, 1076 .h.hashinfo = &dccp_hashinfo, 1077 #ifdef CONFIG_COMPAT 1078 .compat_setsockopt = compat_dccp_setsockopt, 1079 .compat_getsockopt = compat_dccp_getsockopt, 1080 #endif 1081 }; 1082 1083 static const struct inet6_protocol dccp_v6_protocol = { 1084 .handler = dccp_v6_rcv, 1085 .err_handler = dccp_v6_err, 1086 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1087 }; 1088 1089 static const struct proto_ops inet6_dccp_ops = { 1090 .family = PF_INET6, 1091 .owner = THIS_MODULE, 1092 .release = inet6_release, 1093 .bind = inet6_bind, 1094 .connect = inet_stream_connect, 1095 .socketpair = sock_no_socketpair, 1096 .accept = inet_accept, 1097 .getname = inet6_getname, 1098 .poll = dccp_poll, 1099 .ioctl = inet6_ioctl, 1100 .listen = inet_dccp_listen, 1101 .shutdown = inet_shutdown, 1102 .setsockopt = sock_common_setsockopt, 1103 .getsockopt = sock_common_getsockopt, 1104 .sendmsg = inet_sendmsg, 1105 .recvmsg = sock_common_recvmsg, 1106 .mmap = sock_no_mmap, 1107 .sendpage = sock_no_sendpage, 1108 #ifdef CONFIG_COMPAT 1109 .compat_setsockopt = compat_sock_common_setsockopt, 1110 .compat_getsockopt = compat_sock_common_getsockopt, 1111 #endif 1112 }; 1113 1114 static struct inet_protosw dccp_v6_protosw = { 1115 .type = SOCK_DCCP, 1116 .protocol = IPPROTO_DCCP, 1117 .prot = &dccp_v6_prot, 1118 .ops = &inet6_dccp_ops, 1119 .flags = INET_PROTOSW_ICSK, 1120 }; 1121 1122 static int __net_init dccp_v6_init_net(struct net *net) 1123 { 1124 if (dccp_hashinfo.bhash == NULL) 1125 return -ESOCKTNOSUPPORT; 1126 1127 return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6, 1128 SOCK_DCCP, IPPROTO_DCCP, net); 1129 } 1130 1131 static void __net_exit dccp_v6_exit_net(struct net *net) 1132 { 1133 inet_ctl_sock_destroy(net->dccp.v6_ctl_sk); 1134 } 1135 1136 static struct pernet_operations dccp_v6_ops = { 1137 .init = dccp_v6_init_net, 1138 .exit = dccp_v6_exit_net, 1139 }; 1140 1141 static int __init dccp_v6_init(void) 1142 { 1143 int err = proto_register(&dccp_v6_prot, 1); 1144 1145 if (err != 0) 1146 goto out; 1147 1148 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP); 1149 if (err != 0) 1150 goto out_unregister_proto; 1151 1152 inet6_register_protosw(&dccp_v6_protosw); 1153 1154 err = register_pernet_subsys(&dccp_v6_ops); 1155 if (err != 0) 1156 goto out_destroy_ctl_sock; 1157 out: 1158 return err; 1159 1160 out_destroy_ctl_sock: 1161 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP); 1162 inet6_unregister_protosw(&dccp_v6_protosw); 1163 out_unregister_proto: 1164 proto_unregister(&dccp_v6_prot); 1165 goto out; 1166 } 1167 1168 static void __exit dccp_v6_exit(void) 1169 { 1170 unregister_pernet_subsys(&dccp_v6_ops); 1171 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP); 1172 inet6_unregister_protosw(&dccp_v6_protosw); 1173 proto_unregister(&dccp_v6_prot); 1174 } 1175 1176 module_init(dccp_v6_init); 1177 module_exit(dccp_v6_exit); 1178 1179 /* 1180 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33) 1181 * values directly, Also cover the case where the protocol is not specified, 1182 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP 1183 */ 1184 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6); 1185 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6); 1186 MODULE_LICENSE("GPL"); 1187 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>"); 1188 MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol"); 1189