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 (sock_owned_by_user(sk)) 145 goto out; 146 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED)) 147 goto out; 148 149 dst = inet6_csk_update_pmtu(sk, ntohl(info)); 150 if (!dst) 151 goto out; 152 153 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) 154 dccp_sync_mss(sk, dst_mtu(dst)); 155 goto out; 156 } 157 158 icmpv6_err_convert(type, code, &err); 159 160 /* Might be for an request_sock */ 161 switch (sk->sk_state) { 162 struct request_sock *req, **prev; 163 case DCCP_LISTEN: 164 if (sock_owned_by_user(sk)) 165 goto out; 166 167 req = inet6_csk_search_req(sk, &prev, dh->dccph_dport, 168 &hdr->daddr, &hdr->saddr, 169 inet6_iif(skb)); 170 if (req == NULL) 171 goto out; 172 173 /* 174 * ICMPs are not backlogged, hence we cannot get an established 175 * socket here. 176 */ 177 WARN_ON(req->sk != NULL); 178 179 if (!between48(seq, dccp_rsk(req)->dreq_iss, 180 dccp_rsk(req)->dreq_gss)) { 181 NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); 182 goto out; 183 } 184 185 inet_csk_reqsk_queue_drop(sk, req, prev); 186 goto out; 187 188 case DCCP_REQUESTING: 189 case DCCP_RESPOND: /* Cannot happen. 190 It can, it SYNs are crossed. --ANK */ 191 if (!sock_owned_by_user(sk)) { 192 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS); 193 sk->sk_err = err; 194 /* 195 * Wake people up to see the error 196 * (see connect in sock.c) 197 */ 198 sk->sk_error_report(sk); 199 dccp_done(sk); 200 } else 201 sk->sk_err_soft = err; 202 goto out; 203 } 204 205 if (!sock_owned_by_user(sk) && np->recverr) { 206 sk->sk_err = err; 207 sk->sk_error_report(sk); 208 } else 209 sk->sk_err_soft = err; 210 211 out: 212 bh_unlock_sock(sk); 213 sock_put(sk); 214 } 215 216 217 static int dccp_v6_send_response(struct sock *sk, struct request_sock *req) 218 { 219 struct inet_request_sock *ireq = inet_rsk(req); 220 struct ipv6_pinfo *np = inet6_sk(sk); 221 struct sk_buff *skb; 222 struct in6_addr *final_p, final; 223 struct flowi6 fl6; 224 int err = -1; 225 struct dst_entry *dst; 226 227 memset(&fl6, 0, sizeof(fl6)); 228 fl6.flowi6_proto = IPPROTO_DCCP; 229 fl6.daddr = ireq->ir_v6_rmt_addr; 230 fl6.saddr = ireq->ir_v6_loc_addr; 231 fl6.flowlabel = 0; 232 fl6.flowi6_oif = ireq->ir_iif; 233 fl6.fl6_dport = ireq->ir_rmt_port; 234 fl6.fl6_sport = htons(ireq->ir_num); 235 security_req_classify_flow(req, flowi6_to_flowi(&fl6)); 236 237 238 final_p = fl6_update_dst(&fl6, np->opt, &final); 239 240 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false); 241 if (IS_ERR(dst)) { 242 err = PTR_ERR(dst); 243 dst = NULL; 244 goto done; 245 } 246 247 skb = dccp_make_response(sk, dst, req); 248 if (skb != NULL) { 249 struct dccp_hdr *dh = dccp_hdr(skb); 250 251 dh->dccph_checksum = dccp_v6_csum_finish(skb, 252 &ireq->ir_v6_loc_addr, 253 &ireq->ir_v6_rmt_addr); 254 fl6.daddr = ireq->ir_v6_rmt_addr; 255 err = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass); 256 err = net_xmit_eval(err); 257 } 258 259 done: 260 dst_release(dst); 261 return err; 262 } 263 264 static void dccp_v6_reqsk_destructor(struct request_sock *req) 265 { 266 dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg); 267 kfree_skb(inet_rsk(req)->pktopts); 268 } 269 270 static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb) 271 { 272 const struct ipv6hdr *rxip6h; 273 struct sk_buff *skb; 274 struct flowi6 fl6; 275 struct net *net = dev_net(skb_dst(rxskb)->dev); 276 struct sock *ctl_sk = net->dccp.v6_ctl_sk; 277 struct dst_entry *dst; 278 279 if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET) 280 return; 281 282 if (!ipv6_unicast_destination(rxskb)) 283 return; 284 285 skb = dccp_ctl_make_reset(ctl_sk, rxskb); 286 if (skb == NULL) 287 return; 288 289 rxip6h = ipv6_hdr(rxskb); 290 dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr, 291 &rxip6h->daddr); 292 293 memset(&fl6, 0, sizeof(fl6)); 294 fl6.daddr = rxip6h->saddr; 295 fl6.saddr = rxip6h->daddr; 296 297 fl6.flowi6_proto = IPPROTO_DCCP; 298 fl6.flowi6_oif = inet6_iif(rxskb); 299 fl6.fl6_dport = dccp_hdr(skb)->dccph_dport; 300 fl6.fl6_sport = dccp_hdr(skb)->dccph_sport; 301 security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6)); 302 303 /* sk = NULL, but it is safe for now. RST socket required. */ 304 dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false); 305 if (!IS_ERR(dst)) { 306 skb_dst_set(skb, dst); 307 ip6_xmit(ctl_sk, skb, &fl6, NULL, 0); 308 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS); 309 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS); 310 return; 311 } 312 313 kfree_skb(skb); 314 } 315 316 static struct request_sock_ops dccp6_request_sock_ops = { 317 .family = AF_INET6, 318 .obj_size = sizeof(struct dccp6_request_sock), 319 .rtx_syn_ack = dccp_v6_send_response, 320 .send_ack = dccp_reqsk_send_ack, 321 .destructor = dccp_v6_reqsk_destructor, 322 .send_reset = dccp_v6_ctl_send_reset, 323 .syn_ack_timeout = dccp_syn_ack_timeout, 324 }; 325 326 static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb) 327 { 328 const struct dccp_hdr *dh = dccp_hdr(skb); 329 const struct ipv6hdr *iph = ipv6_hdr(skb); 330 struct sock *nsk; 331 struct request_sock **prev; 332 /* Find possible connection requests. */ 333 struct request_sock *req = inet6_csk_search_req(sk, &prev, 334 dh->dccph_sport, 335 &iph->saddr, 336 &iph->daddr, 337 inet6_iif(skb)); 338 if (req != NULL) 339 return dccp_check_req(sk, skb, req, prev); 340 341 nsk = __inet6_lookup_established(sock_net(sk), &dccp_hashinfo, 342 &iph->saddr, dh->dccph_sport, 343 &iph->daddr, ntohs(dh->dccph_dport), 344 inet6_iif(skb)); 345 if (nsk != NULL) { 346 if (nsk->sk_state != DCCP_TIME_WAIT) { 347 bh_lock_sock(nsk); 348 return nsk; 349 } 350 inet_twsk_put(inet_twsk(nsk)); 351 return NULL; 352 } 353 354 return sk; 355 } 356 357 static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb) 358 { 359 struct request_sock *req; 360 struct dccp_request_sock *dreq; 361 struct inet_request_sock *ireq; 362 struct ipv6_pinfo *np = inet6_sk(sk); 363 const __be32 service = dccp_hdr_request(skb)->dccph_req_service; 364 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); 365 366 if (skb->protocol == htons(ETH_P_IP)) 367 return dccp_v4_conn_request(sk, skb); 368 369 if (!ipv6_unicast_destination(skb)) 370 return 0; /* discard, don't send a reset here */ 371 372 if (dccp_bad_service_code(sk, service)) { 373 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE; 374 goto drop; 375 } 376 /* 377 * There are no SYN attacks on IPv6, yet... 378 */ 379 dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY; 380 if (inet_csk_reqsk_queue_is_full(sk)) 381 goto drop; 382 383 if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1) 384 goto drop; 385 386 req = inet6_reqsk_alloc(&dccp6_request_sock_ops); 387 if (req == NULL) 388 goto drop; 389 390 if (dccp_reqsk_init(req, dccp_sk(sk), skb)) 391 goto drop_and_free; 392 393 dreq = dccp_rsk(req); 394 if (dccp_parse_options(sk, dreq, skb)) 395 goto drop_and_free; 396 397 if (security_inet_conn_request(sk, skb, req)) 398 goto drop_and_free; 399 400 ireq = inet_rsk(req); 401 ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; 402 ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; 403 404 if (ipv6_opt_accepted(sk, skb) || 405 np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || 406 np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) { 407 atomic_inc(&skb->users); 408 ireq->pktopts = skb; 409 } 410 ireq->ir_iif = sk->sk_bound_dev_if; 411 412 /* So that link locals have meaning */ 413 if (!sk->sk_bound_dev_if && 414 ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) 415 ireq->ir_iif = inet6_iif(skb); 416 417 /* 418 * Step 3: Process LISTEN state 419 * 420 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie 421 * 422 * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child(). 423 */ 424 dreq->dreq_isr = dcb->dccpd_seq; 425 dreq->dreq_gsr = dreq->dreq_isr; 426 dreq->dreq_iss = dccp_v6_init_sequence(skb); 427 dreq->dreq_gss = dreq->dreq_iss; 428 dreq->dreq_service = service; 429 430 if (dccp_v6_send_response(sk, req)) 431 goto drop_and_free; 432 433 inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT); 434 return 0; 435 436 drop_and_free: 437 reqsk_free(req); 438 drop: 439 DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS); 440 return -1; 441 } 442 443 static struct sock *dccp_v6_request_recv_sock(struct sock *sk, 444 struct sk_buff *skb, 445 struct request_sock *req, 446 struct dst_entry *dst) 447 { 448 struct inet_request_sock *ireq = inet_rsk(req); 449 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 450 struct inet_sock *newinet; 451 struct dccp6_sock *newdp6; 452 struct sock *newsk; 453 454 if (skb->protocol == htons(ETH_P_IP)) { 455 /* 456 * v6 mapped 457 */ 458 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst); 459 if (newsk == NULL) 460 return NULL; 461 462 newdp6 = (struct dccp6_sock *)newsk; 463 newinet = inet_sk(newsk); 464 newinet->pinet6 = &newdp6->inet6; 465 newnp = inet6_sk(newsk); 466 467 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 468 469 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newsk->sk_v6_daddr); 470 471 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr); 472 473 newsk->sk_v6_rcv_saddr = newnp->saddr; 474 475 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped; 476 newsk->sk_backlog_rcv = dccp_v4_do_rcv; 477 newnp->pktoptions = NULL; 478 newnp->opt = NULL; 479 newnp->mcast_oif = inet6_iif(skb); 480 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 481 482 /* 483 * No need to charge this sock to the relevant IPv6 refcnt debug socks count 484 * here, dccp_create_openreq_child now does this for us, see the comment in 485 * that function for the gory details. -acme 486 */ 487 488 /* It is tricky place. Until this moment IPv4 tcp 489 worked with IPv6 icsk.icsk_af_ops. 490 Sync it now. 491 */ 492 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); 493 494 return newsk; 495 } 496 497 498 if (sk_acceptq_is_full(sk)) 499 goto out_overflow; 500 501 if (dst == NULL) { 502 struct in6_addr *final_p, final; 503 struct flowi6 fl6; 504 505 memset(&fl6, 0, sizeof(fl6)); 506 fl6.flowi6_proto = IPPROTO_DCCP; 507 fl6.daddr = ireq->ir_v6_rmt_addr; 508 final_p = fl6_update_dst(&fl6, np->opt, &final); 509 fl6.saddr = ireq->ir_v6_loc_addr; 510 fl6.flowi6_oif = sk->sk_bound_dev_if; 511 fl6.fl6_dport = ireq->ir_rmt_port; 512 fl6.fl6_sport = htons(ireq->ir_num); 513 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 514 515 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false); 516 if (IS_ERR(dst)) 517 goto out; 518 } 519 520 newsk = dccp_create_openreq_child(sk, req, skb); 521 if (newsk == NULL) 522 goto out_nonewsk; 523 524 /* 525 * No need to charge this sock to the relevant IPv6 refcnt debug socks 526 * count here, dccp_create_openreq_child now does this for us, see the 527 * comment in that function for the gory details. -acme 528 */ 529 530 __ip6_dst_store(newsk, dst, NULL, NULL); 531 newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM | 532 NETIF_F_TSO); 533 newdp6 = (struct dccp6_sock *)newsk; 534 newinet = inet_sk(newsk); 535 newinet->pinet6 = &newdp6->inet6; 536 newnp = inet6_sk(newsk); 537 538 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 539 540 newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; 541 newnp->saddr = ireq->ir_v6_loc_addr; 542 newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; 543 newsk->sk_bound_dev_if = ireq->ir_iif; 544 545 /* Now IPv6 options... 546 547 First: no IPv4 options. 548 */ 549 newinet->inet_opt = NULL; 550 551 /* Clone RX bits */ 552 newnp->rxopt.all = np->rxopt.all; 553 554 /* Clone pktoptions received with SYN */ 555 newnp->pktoptions = NULL; 556 if (ireq->pktopts != NULL) { 557 newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC); 558 consume_skb(ireq->pktopts); 559 ireq->pktopts = NULL; 560 if (newnp->pktoptions) 561 skb_set_owner_r(newnp->pktoptions, newsk); 562 } 563 newnp->opt = NULL; 564 newnp->mcast_oif = inet6_iif(skb); 565 newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; 566 567 /* 568 * Clone native IPv6 options from listening socket (if any) 569 * 570 * Yes, keeping reference count would be much more clever, but we make 571 * one more one thing there: reattach optmem to newsk. 572 */ 573 if (np->opt != NULL) 574 newnp->opt = ipv6_dup_options(newsk, np->opt); 575 576 inet_csk(newsk)->icsk_ext_hdr_len = 0; 577 if (newnp->opt != NULL) 578 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen + 579 newnp->opt->opt_flen); 580 581 dccp_sync_mss(newsk, dst_mtu(dst)); 582 583 newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; 584 newinet->inet_rcv_saddr = LOOPBACK4_IPV6; 585 586 if (__inet_inherit_port(sk, newsk) < 0) { 587 inet_csk_prepare_forced_close(newsk); 588 dccp_done(newsk); 589 goto out; 590 } 591 __inet6_hash(newsk, NULL); 592 593 return newsk; 594 595 out_overflow: 596 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); 597 out_nonewsk: 598 dst_release(dst); 599 out: 600 NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); 601 return NULL; 602 } 603 604 /* The socket must have it's spinlock held when we get 605 * here. 606 * 607 * We have a potential double-lock case here, so even when 608 * doing backlog processing we use the BH locking scheme. 609 * This is because we cannot sleep with the original spinlock 610 * held. 611 */ 612 static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 613 { 614 struct ipv6_pinfo *np = inet6_sk(sk); 615 struct sk_buff *opt_skb = NULL; 616 617 /* Imagine: socket is IPv6. IPv4 packet arrives, 618 goes to IPv4 receive handler and backlogged. 619 From backlog it always goes here. Kerboom... 620 Fortunately, dccp_rcv_established and rcv_established 621 handle them correctly, but it is not case with 622 dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK 623 */ 624 625 if (skb->protocol == htons(ETH_P_IP)) 626 return dccp_v4_do_rcv(sk, skb); 627 628 if (sk_filter(sk, skb)) 629 goto discard; 630 631 /* 632 * socket locking is here for SMP purposes as backlog rcv is currently 633 * called with bh processing disabled. 634 */ 635 636 /* Do Stevens' IPV6_PKTOPTIONS. 637 638 Yes, guys, it is the only place in our code, where we 639 may make it not affecting IPv4. 640 The rest of code is protocol independent, 641 and I do not like idea to uglify IPv4. 642 643 Actually, all the idea behind IPV6_PKTOPTIONS 644 looks not very well thought. For now we latch 645 options, received in the last packet, enqueued 646 by tcp. Feel free to propose better solution. 647 --ANK (980728) 648 */ 649 if (np->rxopt.all) 650 /* 651 * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below 652 * (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example. 653 */ 654 opt_skb = skb_clone(skb, GFP_ATOMIC); 655 656 if (sk->sk_state == DCCP_OPEN) { /* Fast path */ 657 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len)) 658 goto reset; 659 if (opt_skb) { 660 /* XXX This is where we would goto ipv6_pktoptions. */ 661 __kfree_skb(opt_skb); 662 } 663 return 0; 664 } 665 666 /* 667 * Step 3: Process LISTEN state 668 * If S.state == LISTEN, 669 * If P.type == Request or P contains a valid Init Cookie option, 670 * (* Must scan the packet's options to check for Init 671 * Cookies. Only Init Cookies are processed here, 672 * however; other options are processed in Step 8. This 673 * scan need only be performed if the endpoint uses Init 674 * Cookies *) 675 * (* Generate a new socket and switch to that socket *) 676 * Set S := new socket for this port pair 677 * S.state = RESPOND 678 * Choose S.ISS (initial seqno) or set from Init Cookies 679 * Initialize S.GAR := S.ISS 680 * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies 681 * Continue with S.state == RESPOND 682 * (* A Response packet will be generated in Step 11 *) 683 * Otherwise, 684 * Generate Reset(No Connection) unless P.type == Reset 685 * Drop packet and return 686 * 687 * NOTE: the check for the packet types is done in 688 * dccp_rcv_state_process 689 */ 690 if (sk->sk_state == DCCP_LISTEN) { 691 struct sock *nsk = dccp_v6_hnd_req(sk, skb); 692 693 if (nsk == NULL) 694 goto discard; 695 /* 696 * Queue it on the new socket if the new socket is active, 697 * otherwise we just shortcircuit this and continue with 698 * the new socket.. 699 */ 700 if (nsk != sk) { 701 if (dccp_child_process(sk, nsk, skb)) 702 goto reset; 703 if (opt_skb != NULL) 704 __kfree_skb(opt_skb); 705 return 0; 706 } 707 } 708 709 if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len)) 710 goto reset; 711 if (opt_skb) { 712 /* XXX This is where we would goto ipv6_pktoptions. */ 713 __kfree_skb(opt_skb); 714 } 715 return 0; 716 717 reset: 718 dccp_v6_ctl_send_reset(sk, skb); 719 discard: 720 if (opt_skb != NULL) 721 __kfree_skb(opt_skb); 722 kfree_skb(skb); 723 return 0; 724 } 725 726 static int dccp_v6_rcv(struct sk_buff *skb) 727 { 728 const struct dccp_hdr *dh; 729 struct sock *sk; 730 int min_cov; 731 732 /* Step 1: Check header basics */ 733 734 if (dccp_invalid_packet(skb)) 735 goto discard_it; 736 737 /* Step 1: If header checksum is incorrect, drop packet and return. */ 738 if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr, 739 &ipv6_hdr(skb)->daddr)) { 740 DCCP_WARN("dropped packet with invalid checksum\n"); 741 goto discard_it; 742 } 743 744 dh = dccp_hdr(skb); 745 746 DCCP_SKB_CB(skb)->dccpd_seq = dccp_hdr_seq(dh); 747 DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type; 748 749 if (dccp_packet_without_ack(skb)) 750 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ; 751 else 752 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb); 753 754 /* Step 2: 755 * Look up flow ID in table and get corresponding socket */ 756 sk = __inet6_lookup_skb(&dccp_hashinfo, skb, 757 dh->dccph_sport, dh->dccph_dport); 758 /* 759 * Step 2: 760 * If no socket ... 761 */ 762 if (sk == NULL) { 763 dccp_pr_debug("failed to look up flow ID in table and " 764 "get corresponding socket\n"); 765 goto no_dccp_socket; 766 } 767 768 /* 769 * Step 2: 770 * ... or S.state == TIMEWAIT, 771 * Generate Reset(No Connection) unless P.type == Reset 772 * Drop packet and return 773 */ 774 if (sk->sk_state == DCCP_TIME_WAIT) { 775 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n"); 776 inet_twsk_put(inet_twsk(sk)); 777 goto no_dccp_socket; 778 } 779 780 /* 781 * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage 782 * o if MinCsCov = 0, only packets with CsCov = 0 are accepted 783 * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov 784 */ 785 min_cov = dccp_sk(sk)->dccps_pcrlen; 786 if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) { 787 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n", 788 dh->dccph_cscov, min_cov); 789 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */ 790 goto discard_and_relse; 791 } 792 793 if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) 794 goto discard_and_relse; 795 796 return sk_receive_skb(sk, skb, 1) ? -1 : 0; 797 798 no_dccp_socket: 799 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) 800 goto discard_it; 801 /* 802 * Step 2: 803 * If no socket ... 804 * Generate Reset(No Connection) unless P.type == Reset 805 * Drop packet and return 806 */ 807 if (dh->dccph_type != DCCP_PKT_RESET) { 808 DCCP_SKB_CB(skb)->dccpd_reset_code = 809 DCCP_RESET_CODE_NO_CONNECTION; 810 dccp_v6_ctl_send_reset(sk, skb); 811 } 812 813 discard_it: 814 kfree_skb(skb); 815 return 0; 816 817 discard_and_relse: 818 sock_put(sk); 819 goto discard_it; 820 } 821 822 static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr, 823 int addr_len) 824 { 825 struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr; 826 struct inet_connection_sock *icsk = inet_csk(sk); 827 struct inet_sock *inet = inet_sk(sk); 828 struct ipv6_pinfo *np = inet6_sk(sk); 829 struct dccp_sock *dp = dccp_sk(sk); 830 struct in6_addr *saddr = NULL, *final_p, final; 831 struct flowi6 fl6; 832 struct dst_entry *dst; 833 int addr_type; 834 int err; 835 836 dp->dccps_role = DCCP_ROLE_CLIENT; 837 838 if (addr_len < SIN6_LEN_RFC2133) 839 return -EINVAL; 840 841 if (usin->sin6_family != AF_INET6) 842 return -EAFNOSUPPORT; 843 844 memset(&fl6, 0, sizeof(fl6)); 845 846 if (np->sndflow) { 847 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK; 848 IP6_ECN_flow_init(fl6.flowlabel); 849 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) { 850 struct ip6_flowlabel *flowlabel; 851 flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); 852 if (flowlabel == NULL) 853 return -EINVAL; 854 fl6_sock_release(flowlabel); 855 } 856 } 857 /* 858 * connect() to INADDR_ANY means loopback (BSD'ism). 859 */ 860 if (ipv6_addr_any(&usin->sin6_addr)) 861 usin->sin6_addr.s6_addr[15] = 1; 862 863 addr_type = ipv6_addr_type(&usin->sin6_addr); 864 865 if (addr_type & IPV6_ADDR_MULTICAST) 866 return -ENETUNREACH; 867 868 if (addr_type & IPV6_ADDR_LINKLOCAL) { 869 if (addr_len >= sizeof(struct sockaddr_in6) && 870 usin->sin6_scope_id) { 871 /* If interface is set while binding, indices 872 * must coincide. 873 */ 874 if (sk->sk_bound_dev_if && 875 sk->sk_bound_dev_if != usin->sin6_scope_id) 876 return -EINVAL; 877 878 sk->sk_bound_dev_if = usin->sin6_scope_id; 879 } 880 881 /* Connect to link-local address requires an interface */ 882 if (!sk->sk_bound_dev_if) 883 return -EINVAL; 884 } 885 886 sk->sk_v6_daddr = usin->sin6_addr; 887 np->flow_label = fl6.flowlabel; 888 889 /* 890 * DCCP over IPv4 891 */ 892 if (addr_type == IPV6_ADDR_MAPPED) { 893 u32 exthdrlen = icsk->icsk_ext_hdr_len; 894 struct sockaddr_in sin; 895 896 SOCK_DEBUG(sk, "connect: ipv4 mapped\n"); 897 898 if (__ipv6_only_sock(sk)) 899 return -ENETUNREACH; 900 901 sin.sin_family = AF_INET; 902 sin.sin_port = usin->sin6_port; 903 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; 904 905 icsk->icsk_af_ops = &dccp_ipv6_mapped; 906 sk->sk_backlog_rcv = dccp_v4_do_rcv; 907 908 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); 909 if (err) { 910 icsk->icsk_ext_hdr_len = exthdrlen; 911 icsk->icsk_af_ops = &dccp_ipv6_af_ops; 912 sk->sk_backlog_rcv = dccp_v6_do_rcv; 913 goto failure; 914 } 915 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr); 916 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr, &sk->sk_v6_rcv_saddr); 917 918 return err; 919 } 920 921 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 922 saddr = &sk->sk_v6_rcv_saddr; 923 924 fl6.flowi6_proto = IPPROTO_DCCP; 925 fl6.daddr = sk->sk_v6_daddr; 926 fl6.saddr = saddr ? *saddr : np->saddr; 927 fl6.flowi6_oif = sk->sk_bound_dev_if; 928 fl6.fl6_dport = usin->sin6_port; 929 fl6.fl6_sport = inet->inet_sport; 930 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); 931 932 final_p = fl6_update_dst(&fl6, np->opt, &final); 933 934 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true); 935 if (IS_ERR(dst)) { 936 err = PTR_ERR(dst); 937 goto failure; 938 } 939 940 if (saddr == NULL) { 941 saddr = &fl6.saddr; 942 sk->sk_v6_rcv_saddr = *saddr; 943 } 944 945 /* set the source address */ 946 np->saddr = *saddr; 947 inet->inet_rcv_saddr = LOOPBACK4_IPV6; 948 949 __ip6_dst_store(sk, dst, NULL, NULL); 950 951 icsk->icsk_ext_hdr_len = 0; 952 if (np->opt != NULL) 953 icsk->icsk_ext_hdr_len = (np->opt->opt_flen + 954 np->opt->opt_nflen); 955 956 inet->inet_dport = usin->sin6_port; 957 958 dccp_set_state(sk, DCCP_REQUESTING); 959 err = inet6_hash_connect(&dccp_death_row, sk); 960 if (err) 961 goto late_failure; 962 963 dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32, 964 sk->sk_v6_daddr.s6_addr32, 965 inet->inet_sport, 966 inet->inet_dport); 967 err = dccp_connect(sk); 968 if (err) 969 goto late_failure; 970 971 return 0; 972 973 late_failure: 974 dccp_set_state(sk, DCCP_CLOSED); 975 __sk_dst_reset(sk); 976 failure: 977 inet->inet_dport = 0; 978 sk->sk_route_caps = 0; 979 return err; 980 } 981 982 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = { 983 .queue_xmit = inet6_csk_xmit, 984 .send_check = dccp_v6_send_check, 985 .rebuild_header = inet6_sk_rebuild_header, 986 .conn_request = dccp_v6_conn_request, 987 .syn_recv_sock = dccp_v6_request_recv_sock, 988 .net_header_len = sizeof(struct ipv6hdr), 989 .setsockopt = ipv6_setsockopt, 990 .getsockopt = ipv6_getsockopt, 991 .addr2sockaddr = inet6_csk_addr2sockaddr, 992 .sockaddr_len = sizeof(struct sockaddr_in6), 993 .bind_conflict = inet6_csk_bind_conflict, 994 #ifdef CONFIG_COMPAT 995 .compat_setsockopt = compat_ipv6_setsockopt, 996 .compat_getsockopt = compat_ipv6_getsockopt, 997 #endif 998 }; 999 1000 /* 1001 * DCCP over IPv4 via INET6 API 1002 */ 1003 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = { 1004 .queue_xmit = ip_queue_xmit, 1005 .send_check = dccp_v4_send_check, 1006 .rebuild_header = inet_sk_rebuild_header, 1007 .conn_request = dccp_v6_conn_request, 1008 .syn_recv_sock = dccp_v6_request_recv_sock, 1009 .net_header_len = sizeof(struct iphdr), 1010 .setsockopt = ipv6_setsockopt, 1011 .getsockopt = ipv6_getsockopt, 1012 .addr2sockaddr = inet6_csk_addr2sockaddr, 1013 .sockaddr_len = sizeof(struct sockaddr_in6), 1014 #ifdef CONFIG_COMPAT 1015 .compat_setsockopt = compat_ipv6_setsockopt, 1016 .compat_getsockopt = compat_ipv6_getsockopt, 1017 #endif 1018 }; 1019 1020 /* NOTE: A lot of things set to zero explicitly by call to 1021 * sk_alloc() so need not be done here. 1022 */ 1023 static int dccp_v6_init_sock(struct sock *sk) 1024 { 1025 static __u8 dccp_v6_ctl_sock_initialized; 1026 int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized); 1027 1028 if (err == 0) { 1029 if (unlikely(!dccp_v6_ctl_sock_initialized)) 1030 dccp_v6_ctl_sock_initialized = 1; 1031 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops; 1032 } 1033 1034 return err; 1035 } 1036 1037 static void dccp_v6_destroy_sock(struct sock *sk) 1038 { 1039 dccp_destroy_sock(sk); 1040 inet6_destroy_sock(sk); 1041 } 1042 1043 static struct timewait_sock_ops dccp6_timewait_sock_ops = { 1044 .twsk_obj_size = sizeof(struct dccp6_timewait_sock), 1045 }; 1046 1047 static struct proto dccp_v6_prot = { 1048 .name = "DCCPv6", 1049 .owner = THIS_MODULE, 1050 .close = dccp_close, 1051 .connect = dccp_v6_connect, 1052 .disconnect = dccp_disconnect, 1053 .ioctl = dccp_ioctl, 1054 .init = dccp_v6_init_sock, 1055 .setsockopt = dccp_setsockopt, 1056 .getsockopt = dccp_getsockopt, 1057 .sendmsg = dccp_sendmsg, 1058 .recvmsg = dccp_recvmsg, 1059 .backlog_rcv = dccp_v6_do_rcv, 1060 .hash = dccp_v6_hash, 1061 .unhash = inet_unhash, 1062 .accept = inet_csk_accept, 1063 .get_port = inet_csk_get_port, 1064 .shutdown = dccp_shutdown, 1065 .destroy = dccp_v6_destroy_sock, 1066 .orphan_count = &dccp_orphan_count, 1067 .max_header = MAX_DCCP_HEADER, 1068 .obj_size = sizeof(struct dccp6_sock), 1069 .slab_flags = SLAB_DESTROY_BY_RCU, 1070 .rsk_prot = &dccp6_request_sock_ops, 1071 .twsk_prot = &dccp6_timewait_sock_ops, 1072 .h.hashinfo = &dccp_hashinfo, 1073 #ifdef CONFIG_COMPAT 1074 .compat_setsockopt = compat_dccp_setsockopt, 1075 .compat_getsockopt = compat_dccp_getsockopt, 1076 #endif 1077 }; 1078 1079 static const struct inet6_protocol dccp_v6_protocol = { 1080 .handler = dccp_v6_rcv, 1081 .err_handler = dccp_v6_err, 1082 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1083 }; 1084 1085 static const struct proto_ops inet6_dccp_ops = { 1086 .family = PF_INET6, 1087 .owner = THIS_MODULE, 1088 .release = inet6_release, 1089 .bind = inet6_bind, 1090 .connect = inet_stream_connect, 1091 .socketpair = sock_no_socketpair, 1092 .accept = inet_accept, 1093 .getname = inet6_getname, 1094 .poll = dccp_poll, 1095 .ioctl = inet6_ioctl, 1096 .listen = inet_dccp_listen, 1097 .shutdown = inet_shutdown, 1098 .setsockopt = sock_common_setsockopt, 1099 .getsockopt = sock_common_getsockopt, 1100 .sendmsg = inet_sendmsg, 1101 .recvmsg = sock_common_recvmsg, 1102 .mmap = sock_no_mmap, 1103 .sendpage = sock_no_sendpage, 1104 #ifdef CONFIG_COMPAT 1105 .compat_setsockopt = compat_sock_common_setsockopt, 1106 .compat_getsockopt = compat_sock_common_getsockopt, 1107 #endif 1108 }; 1109 1110 static struct inet_protosw dccp_v6_protosw = { 1111 .type = SOCK_DCCP, 1112 .protocol = IPPROTO_DCCP, 1113 .prot = &dccp_v6_prot, 1114 .ops = &inet6_dccp_ops, 1115 .flags = INET_PROTOSW_ICSK, 1116 }; 1117 1118 static int __net_init dccp_v6_init_net(struct net *net) 1119 { 1120 if (dccp_hashinfo.bhash == NULL) 1121 return -ESOCKTNOSUPPORT; 1122 1123 return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6, 1124 SOCK_DCCP, IPPROTO_DCCP, net); 1125 } 1126 1127 static void __net_exit dccp_v6_exit_net(struct net *net) 1128 { 1129 inet_ctl_sock_destroy(net->dccp.v6_ctl_sk); 1130 } 1131 1132 static struct pernet_operations dccp_v6_ops = { 1133 .init = dccp_v6_init_net, 1134 .exit = dccp_v6_exit_net, 1135 }; 1136 1137 static int __init dccp_v6_init(void) 1138 { 1139 int err = proto_register(&dccp_v6_prot, 1); 1140 1141 if (err != 0) 1142 goto out; 1143 1144 err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP); 1145 if (err != 0) 1146 goto out_unregister_proto; 1147 1148 inet6_register_protosw(&dccp_v6_protosw); 1149 1150 err = register_pernet_subsys(&dccp_v6_ops); 1151 if (err != 0) 1152 goto out_destroy_ctl_sock; 1153 out: 1154 return err; 1155 1156 out_destroy_ctl_sock: 1157 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP); 1158 inet6_unregister_protosw(&dccp_v6_protosw); 1159 out_unregister_proto: 1160 proto_unregister(&dccp_v6_prot); 1161 goto out; 1162 } 1163 1164 static void __exit dccp_v6_exit(void) 1165 { 1166 unregister_pernet_subsys(&dccp_v6_ops); 1167 inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP); 1168 inet6_unregister_protosw(&dccp_v6_protosw); 1169 proto_unregister(&dccp_v6_prot); 1170 } 1171 1172 module_init(dccp_v6_init); 1173 module_exit(dccp_v6_exit); 1174 1175 /* 1176 * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33) 1177 * values directly, Also cover the case where the protocol is not specified, 1178 * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP 1179 */ 1180 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6); 1181 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6); 1182 MODULE_LICENSE("GPL"); 1183 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>"); 1184 MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol"); 1185