net/dccp/ipv6.c

   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, &np->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         }
 139
 140         if (type == ICMPV6_PKT_TOOBIG) {
 141                 struct dst_entry *dst = NULL;
 142
 143                 if (sock_owned_by_user(sk))
 144                         goto out;
 145                 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
 146                         goto out;
 147
 148                 dst = inet6_csk_update_pmtu(sk, ntohl(info));
 149                 if (!dst)
 150                         goto out;
 151
 152                 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst))
 153                         dccp_sync_mss(sk, dst_mtu(dst));
 154                 goto out;
 155         }
 156
 157         icmpv6_err_convert(type, code, &err);
 158
 159         /* Might be for an request_sock */
 160         switch (sk->sk_state) {
 161                 struct request_sock *req, **prev;
 162         case DCCP_LISTEN:
 163                 if (sock_owned_by_user(sk))
 164                         goto out;
 165
 166                 req = inet6_csk_search_req(sk, &prev, dh->dccph_dport,
 167                                            &hdr->daddr, &hdr->saddr,
 168                                            inet6_iif(skb));
 169                 if (req == NULL)
 170                         goto out;
 171
 172                 /*
 173                  * ICMPs are not backlogged, hence we cannot get an established
 174                  * socket here.
 175                  */
 176                 WARN_ON(req->sk != NULL);
 177
 178                 if (!between48(seq, dccp_rsk(req)->dreq_iss,
 179                                     dccp_rsk(req)->dreq_gss)) {
 180                         NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
 181                         goto out;
 182                 }
 183
 184                 inet_csk_reqsk_queue_drop(sk, req, prev);
 185                 goto out;
 186
 187         case DCCP_REQUESTING:
 188         case DCCP_RESPOND:  /* Cannot happen.
 189                                It can, it SYNs are crossed. --ANK */
 190                 if (!sock_owned_by_user(sk)) {
 191                         DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
 192                         sk->sk_err = err;
 193                         /*
 194                          * Wake people up to see the error
 195                          * (see connect in sock.c)
 196                          */
 197                         sk->sk_error_report(sk);
 198                         dccp_done(sk);
 199                 } else
 200                         sk->sk_err_soft = err;
 201                 goto out;
 202         }
 203
 204         if (!sock_owned_by_user(sk) && np->recverr) {
 205                 sk->sk_err = err;
 206                 sk->sk_error_report(sk);
 207         } else
 208                 sk->sk_err_soft = err;
 209
 210 out:
 211         bh_unlock_sock(sk);
 212         sock_put(sk);
 213 }
 214
 215
 216 static int dccp_v6_send_response(struct sock *sk, struct request_sock *req,
 217                                  struct request_values *rv_unused)
 218 {
 219         struct inet6_request_sock *ireq6 = inet6_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 = ireq6->rmt_addr;
 230         fl6.saddr = ireq6->loc_addr;
 231         fl6.flowlabel = 0;
 232         fl6.flowi6_oif = ireq6->iif;
 233         fl6.fl6_dport = inet_rsk(req)->rmt_port;
 234         fl6.fl6_sport = inet_rsk(req)->loc_port;
 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                                                          &ireq6->loc_addr,
 253                                                          &ireq6->rmt_addr);
 254                 fl6.daddr = ireq6->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         if (inet6_rsk(req)->pktopts != NULL)
 268                 kfree_skb(inet6_rsk(req)->pktopts);
 269 }
 270
 271 static void dccp_v6_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
 272 {
 273         const struct ipv6hdr *rxip6h;
 274         struct sk_buff *skb;
 275         struct flowi6 fl6;
 276         struct net *net = dev_net(skb_dst(rxskb)->dev);
 277         struct sock *ctl_sk = net->dccp.v6_ctl_sk;
 278         struct dst_entry *dst;
 279
 280         if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
 281                 return;
 282
 283         if (!ipv6_unicast_destination(rxskb))
 284                 return;
 285
 286         skb = dccp_ctl_make_reset(ctl_sk, rxskb);
 287         if (skb == NULL)
 288                 return;
 289
 290         rxip6h = ipv6_hdr(rxskb);
 291         dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
 292                                                             &rxip6h->daddr);
 293
 294         memset(&fl6, 0, sizeof(fl6));
 295         fl6.daddr = rxip6h->saddr;
 296         fl6.saddr = rxip6h->daddr;
 297
 298         fl6.flowi6_proto = IPPROTO_DCCP;
 299         fl6.flowi6_oif = inet6_iif(rxskb);
 300         fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
 301         fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
 302         security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6));
 303
 304         /* sk = NULL, but it is safe for now. RST socket required. */
 305         dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL, false);
 306         if (!IS_ERR(dst)) {
 307                 skb_dst_set(skb, dst);
 308                 ip6_xmit(ctl_sk, skb, &fl6, NULL, 0);
 309                 DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
 310                 DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
 311                 return;
 312         }
 313
 314         kfree_skb(skb);
 315 }
 316
 317 static struct request_sock_ops dccp6_request_sock_ops = {
 318         .family         = AF_INET6,
 319         .obj_size       = sizeof(struct dccp6_request_sock),
 320         .rtx_syn_ack    = dccp_v6_send_response,
 321         .send_ack       = dccp_reqsk_send_ack,
 322         .destructor     = dccp_v6_reqsk_destructor,
 323         .send_reset     = dccp_v6_ctl_send_reset,
 324         .syn_ack_timeout = dccp_syn_ack_timeout,
 325 };
 326
 327 static struct sock *dccp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
 328 {
 329         const struct dccp_hdr *dh = dccp_hdr(skb);
 330         const struct ipv6hdr *iph = ipv6_hdr(skb);
 331         struct sock *nsk;
 332         struct request_sock **prev;
 333         /* Find possible connection requests. */
 334         struct request_sock *req = inet6_csk_search_req(sk, &prev,
 335                                                         dh->dccph_sport,
 336                                                         &iph->saddr,
 337                                                         &iph->daddr,
 338                                                         inet6_iif(skb));
 339         if (req != NULL)
 340                 return dccp_check_req(sk, skb, req, prev);
 341
 342         nsk = __inet6_lookup_established(sock_net(sk), &dccp_hashinfo,
 343                                          &iph->saddr, dh->dccph_sport,
 344                                          &iph->daddr, ntohs(dh->dccph_dport),
 345                                          inet6_iif(skb));
 346         if (nsk != NULL) {
 347                 if (nsk->sk_state != DCCP_TIME_WAIT) {
 348                         bh_lock_sock(nsk);
 349                         return nsk;
 350                 }
 351                 inet_twsk_put(inet_twsk(nsk));
 352                 return NULL;
 353         }
 354
 355         return sk;
 356 }
 357
 358 static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 359 {
 360         struct request_sock *req;
 361         struct dccp_request_sock *dreq;
 362         struct inet6_request_sock *ireq6;
 363         struct ipv6_pinfo *np = inet6_sk(sk);
 364         const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
 365         struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
 366
 367         if (skb->protocol == htons(ETH_P_IP))
 368                 return dccp_v4_conn_request(sk, skb);
 369
 370         if (!ipv6_unicast_destination(skb))
 371                 return 0;       /* discard, don't send a reset here */
 372
 373         if (dccp_bad_service_code(sk, service)) {
 374                 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
 375                 goto drop;
 376         }
 377         /*
 378          * There are no SYN attacks on IPv6, yet...
 379          */
 380         dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
 381         if (inet_csk_reqsk_queue_is_full(sk))
 382                 goto drop;
 383
 384         if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
 385                 goto drop;
 386
 387         req = inet6_reqsk_alloc(&dccp6_request_sock_ops);
 388         if (req == NULL)
 389                 goto drop;
 390
 391         if (dccp_reqsk_init(req, dccp_sk(sk), skb))
 392                 goto drop_and_free;
 393
 394         dreq = dccp_rsk(req);
 395         if (dccp_parse_options(sk, dreq, skb))
 396                 goto drop_and_free;
 397
 398         if (security_inet_conn_request(sk, skb, req))
 399                 goto drop_and_free;
 400
 401         ireq6 = inet6_rsk(req);
 402         ireq6->rmt_addr = ipv6_hdr(skb)->saddr;
 403         ireq6->loc_addr = ipv6_hdr(skb)->daddr;
 404
 405         if (ipv6_opt_accepted(sk, skb) ||
 406             np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
 407             np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
 408                 atomic_inc(&skb->users);
 409                 ireq6->pktopts = skb;
 410         }
 411         ireq6->iif = sk->sk_bound_dev_if;
 412
 413         /* So that link locals have meaning */
 414         if (!sk->sk_bound_dev_if &&
 415             ipv6_addr_type(&ireq6->rmt_addr) & IPV6_ADDR_LINKLOCAL)
 416                 ireq6->iif = inet6_iif(skb);
 417
 418         /*
 419          * Step 3: Process LISTEN state
 420          *
 421          *   Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
 422          *
 423          * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
 424          */
 425         dreq->dreq_isr     = dcb->dccpd_seq;
 426         dreq->dreq_gsr     = dreq->dreq_isr;
 427         dreq->dreq_iss     = dccp_v6_init_sequence(skb);
 428         dreq->dreq_gss     = dreq->dreq_iss;
 429         dreq->dreq_service = service;
 430
 431         if (dccp_v6_send_response(sk, req, NULL))
 432                 goto drop_and_free;
 433
 434         inet6_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
 435         return 0;
 436
 437 drop_and_free:
 438         reqsk_free(req);
 439 drop:
 440         DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
 441         return -1;
 442 }
 443
 444 static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 445                                               struct sk_buff *skb,
 446                                               struct request_sock *req,
 447                                               struct dst_entry *dst)
 448 {
 449         struct inet6_request_sock *ireq6 = inet6_rsk(req);
 450         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 451         struct inet_sock *newinet;
 452         struct dccp6_sock *newdp6;
 453         struct sock *newsk;
 454
 455         if (skb->protocol == htons(ETH_P_IP)) {
 456                 /*
 457                  *      v6 mapped
 458                  */
 459                 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst);
 460                 if (newsk == NULL)
 461                         return NULL;
 462
 463                 newdp6 = (struct dccp6_sock *)newsk;
 464                 newinet = inet_sk(newsk);
 465                 newinet->pinet6 = &newdp6->inet6;
 466                 newnp = inet6_sk(newsk);
 467
 468                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 469
 470                 ipv6_addr_set_v4mapped(newinet->inet_daddr, &newnp->daddr);
 471
 472                 ipv6_addr_set_v4mapped(newinet->inet_saddr, &newnp->saddr);
 473
 474                 newnp->rcv_saddr = newnp->saddr;
 475
 476                 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
 477                 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
 478                 newnp->pktoptions  = NULL;
 479                 newnp->opt         = NULL;
 480                 newnp->mcast_oif   = inet6_iif(skb);
 481                 newnp->mcast_hops  = ipv6_hdr(skb)->hop_limit;
 482
 483                 /*
 484                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
 485                  * here, dccp_create_openreq_child now does this for us, see the comment in
 486                  * that function for the gory details. -acme
 487                  */
 488
 489                 /* It is tricky place. Until this moment IPv4 tcp
 490                    worked with IPv6 icsk.icsk_af_ops.
 491                    Sync it now.
 492                  */
 493                 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
 494
 495                 return newsk;
 496         }
 497
 498
 499         if (sk_acceptq_is_full(sk))
 500                 goto out_overflow;
 501
 502         if (dst == NULL) {
 503                 struct in6_addr *final_p, final;
 504                 struct flowi6 fl6;
 505
 506                 memset(&fl6, 0, sizeof(fl6));
 507                 fl6.flowi6_proto = IPPROTO_DCCP;
 508                 fl6.daddr = ireq6->rmt_addr;
 509                 final_p = fl6_update_dst(&fl6, np->opt, &final);
 510                 fl6.saddr = ireq6->loc_addr;
 511                 fl6.flowi6_oif = sk->sk_bound_dev_if;
 512                 fl6.fl6_dport = inet_rsk(req)->rmt_port;
 513                 fl6.fl6_sport = inet_rsk(req)->loc_port;
 514                 security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 515
 516                 dst = ip6_dst_lookup_flow(sk, &fl6, final_p, false);
 517                 if (IS_ERR(dst))
 518                         goto out;
 519         }
 520
 521         newsk = dccp_create_openreq_child(sk, req, skb);
 522         if (newsk == NULL)
 523                 goto out_nonewsk;
 524
 525         /*
 526          * No need to charge this sock to the relevant IPv6 refcnt debug socks
 527          * count here, dccp_create_openreq_child now does this for us, see the
 528          * comment in that function for the gory details. -acme
 529          */
 530
 531         __ip6_dst_store(newsk, dst, NULL, NULL);
 532         newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
 533                                                       NETIF_F_TSO);
 534         newdp6 = (struct dccp6_sock *)newsk;
 535         newinet = inet_sk(newsk);
 536         newinet->pinet6 = &newdp6->inet6;
 537         newnp = inet6_sk(newsk);
 538
 539         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 540
 541         newnp->daddr = ireq6->rmt_addr;
 542         newnp->saddr = ireq6->loc_addr;
 543         newnp->rcv_saddr = ireq6->loc_addr;
 544         newsk->sk_bound_dev_if = ireq6->iif;
 545
 546         /* Now IPv6 options...
 547
 548            First: no IPv4 options.
 549          */
 550         newinet->inet_opt = NULL;
 551
 552         /* Clone RX bits */
 553         newnp->rxopt.all = np->rxopt.all;
 554
 555         /* Clone pktoptions received with SYN */
 556         newnp->pktoptions = NULL;
 557         if (ireq6->pktopts != NULL) {
 558                 newnp->pktoptions = skb_clone(ireq6->pktopts, GFP_ATOMIC);
 559                 consume_skb(ireq6->pktopts);
 560                 ireq6->pktopts = NULL;
 561                 if (newnp->pktoptions)
 562                         skb_set_owner_r(newnp->pktoptions, newsk);
 563         }
 564         newnp->opt        = NULL;
 565         newnp->mcast_oif  = inet6_iif(skb);
 566         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
 567
 568         /*
 569          * Clone native IPv6 options from listening socket (if any)
 570          *
 571          * Yes, keeping reference count would be much more clever, but we make
 572          * one more one thing there: reattach optmem to newsk.
 573          */
 574         if (np->opt != NULL)
 575                 newnp->opt = ipv6_dup_options(newsk, np->opt);
 576
 577         inet_csk(newsk)->icsk_ext_hdr_len = 0;
 578         if (newnp->opt != NULL)
 579                 inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
 580                                                      newnp->opt->opt_flen);
 581
 582         dccp_sync_mss(newsk, dst_mtu(dst));
 583
 584         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
 585         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
 586
 587         if (__inet_inherit_port(sk, newsk) < 0) {
 588                 inet_csk_prepare_forced_close(newsk);
 589                 dccp_done(newsk);
 590                 goto out;
 591         }
 592         __inet6_hash(newsk, NULL);
 593
 594         return newsk;
 595
 596 out_overflow:
 597         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
 598 out_nonewsk:
 599         dst_release(dst);
 600 out:
 601         NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
 602         return NULL;
 603 }
 604
 605 /* The socket must have it's spinlock held when we get
 606  * here.
 607  *
 608  * We have a potential double-lock case here, so even when
 609  * doing backlog processing we use the BH locking scheme.
 610  * This is because we cannot sleep with the original spinlock
 611  * held.
 612  */
 613 static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 614 {
 615         struct ipv6_pinfo *np = inet6_sk(sk);
 616         struct sk_buff *opt_skb = NULL;
 617
 618         /* Imagine: socket is IPv6. IPv4 packet arrives,
 619            goes to IPv4 receive handler and backlogged.
 620            From backlog it always goes here. Kerboom...
 621            Fortunately, dccp_rcv_established and rcv_established
 622            handle them correctly, but it is not case with
 623            dccp_v6_hnd_req and dccp_v6_ctl_send_reset().   --ANK
 624          */
 625
 626         if (skb->protocol == htons(ETH_P_IP))
 627                 return dccp_v4_do_rcv(sk, skb);
 628
 629         if (sk_filter(sk, skb))
 630                 goto discard;
 631
 632         /*
 633          * socket locking is here for SMP purposes as backlog rcv is currently
 634          * called with bh processing disabled.
 635          */
 636
 637         /* Do Stevens' IPV6_PKTOPTIONS.
 638
 639            Yes, guys, it is the only place in our code, where we
 640            may make it not affecting IPv4.
 641            The rest of code is protocol independent,
 642            and I do not like idea to uglify IPv4.
 643
 644            Actually, all the idea behind IPV6_PKTOPTIONS
 645            looks not very well thought. For now we latch
 646            options, received in the last packet, enqueued
 647            by tcp. Feel free to propose better solution.
 648                                                --ANK (980728)
 649          */
 650         if (np->rxopt.all)
 651         /*
 652          * FIXME: Add handling of IPV6_PKTOPTIONS skb. See the comments below
 653          *        (wrt ipv6_pktopions) and net/ipv6/tcp_ipv6.c for an example.
 654          */
 655                 opt_skb = skb_clone(skb, GFP_ATOMIC);
 656
 657         if (sk->sk_state == DCCP_OPEN) { /* Fast path */
 658                 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
 659                         goto reset;
 660                 if (opt_skb) {
 661                         /* XXX This is where we would goto ipv6_pktoptions. */
 662                         __kfree_skb(opt_skb);
 663                 }
 664                 return 0;
 665         }
 666
 667         /*
 668          *  Step 3: Process LISTEN state
 669          *     If S.state == LISTEN,
 670          *       If P.type == Request or P contains a valid Init Cookie option,
 671          *            (* Must scan the packet's options to check for Init
 672          *               Cookies.  Only Init Cookies are processed here,
 673          *               however; other options are processed in Step 8.  This
 674          *               scan need only be performed if the endpoint uses Init
 675          *               Cookies *)
 676          *            (* Generate a new socket and switch to that socket *)
 677          *            Set S := new socket for this port pair
 678          *            S.state = RESPOND
 679          *            Choose S.ISS (initial seqno) or set from Init Cookies
 680          *            Initialize S.GAR := S.ISS
 681          *            Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
 682          *            Continue with S.state == RESPOND
 683          *            (* A Response packet will be generated in Step 11 *)
 684          *       Otherwise,
 685          *            Generate Reset(No Connection) unless P.type == Reset
 686          *            Drop packet and return
 687          *
 688          * NOTE: the check for the packet types is done in
 689          *       dccp_rcv_state_process
 690          */
 691         if (sk->sk_state == DCCP_LISTEN) {
 692                 struct sock *nsk = dccp_v6_hnd_req(sk, skb);
 693
 694                 if (nsk == NULL)
 695                         goto discard;
 696                 /*
 697                  * Queue it on the new socket if the new socket is active,
 698                  * otherwise we just shortcircuit this and continue with
 699                  * the new socket..
 700                  */
 701                 if (nsk != sk) {
 702                         if (dccp_child_process(sk, nsk, skb))
 703                                 goto reset;
 704                         if (opt_skb != NULL)
 705                                 __kfree_skb(opt_skb);
 706                         return 0;
 707                 }
 708         }
 709
 710         if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
 711                 goto reset;
 712         if (opt_skb) {
 713                 /* XXX This is where we would goto ipv6_pktoptions. */
 714                 __kfree_skb(opt_skb);
 715         }
 716         return 0;
 717
 718 reset:
 719         dccp_v6_ctl_send_reset(sk, skb);
 720 discard:
 721         if (opt_skb != NULL)
 722                 __kfree_skb(opt_skb);
 723         kfree_skb(skb);
 724         return 0;
 725 }
 726
 727 static int dccp_v6_rcv(struct sk_buff *skb)
 728 {
 729         const struct dccp_hdr *dh;
 730         struct sock *sk;
 731         int min_cov;
 732
 733         /* Step 1: Check header basics */
 734
 735         if (dccp_invalid_packet(skb))
 736                 goto discard_it;
 737
 738         /* Step 1: If header checksum is incorrect, drop packet and return. */
 739         if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
 740                                      &ipv6_hdr(skb)->daddr)) {
 741                 DCCP_WARN("dropped packet with invalid checksum\n");
 742                 goto discard_it;
 743         }
 744
 745         dh = dccp_hdr(skb);
 746
 747         DCCP_SKB_CB(skb)->dccpd_seq  = dccp_hdr_seq(dh);
 748         DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
 749
 750         if (dccp_packet_without_ack(skb))
 751                 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
 752         else
 753                 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
 754
 755         /* Step 2:
 756          *      Look up flow ID in table and get corresponding socket */
 757         sk = __inet6_lookup_skb(&dccp_hashinfo, skb,
 758                                 dh->dccph_sport, dh->dccph_dport);
 759         /*
 760          * Step 2:
 761          *      If no socket ...
 762          */
 763         if (sk == NULL) {
 764                 dccp_pr_debug("failed to look up flow ID in table and "
 765                               "get corresponding socket\n");
 766                 goto no_dccp_socket;
 767         }
 768
 769         /*
 770          * Step 2:
 771          *      ... or S.state == TIMEWAIT,
 772          *              Generate Reset(No Connection) unless P.type == Reset
 773          *              Drop packet and return
 774          */
 775         if (sk->sk_state == DCCP_TIME_WAIT) {
 776                 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
 777                 inet_twsk_put(inet_twsk(sk));
 778                 goto no_dccp_socket;
 779         }
 780
 781         /*
 782          * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
 783          *      o if MinCsCov = 0, only packets with CsCov = 0 are accepted
 784          *      o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
 785          */
 786         min_cov = dccp_sk(sk)->dccps_pcrlen;
 787         if (dh->dccph_cscov  &&  (min_cov == 0 || dh->dccph_cscov < min_cov))  {
 788                 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
 789                               dh->dccph_cscov, min_cov);
 790                 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
 791                 goto discard_and_relse;
 792         }
 793
 794         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 795                 goto discard_and_relse;
 796
 797         return sk_receive_skb(sk, skb, 1) ? -1 : 0;
 798
 799 no_dccp_socket:
 800         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 801                 goto discard_it;
 802         /*
 803          * Step 2:
 804          *      If no socket ...
 805          *              Generate Reset(No Connection) unless P.type == Reset
 806          *              Drop packet and return
 807          */
 808         if (dh->dccph_type != DCCP_PKT_RESET) {
 809                 DCCP_SKB_CB(skb)->dccpd_reset_code =
 810                                         DCCP_RESET_CODE_NO_CONNECTION;
 811                 dccp_v6_ctl_send_reset(sk, skb);
 812         }
 813
 814 discard_it:
 815         kfree_skb(skb);
 816         return 0;
 817
 818 discard_and_relse:
 819         sock_put(sk);
 820         goto discard_it;
 821 }
 822
 823 static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 824                            int addr_len)
 825 {
 826         struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
 827         struct inet_connection_sock *icsk = inet_csk(sk);
 828         struct inet_sock *inet = inet_sk(sk);
 829         struct ipv6_pinfo *np = inet6_sk(sk);
 830         struct dccp_sock *dp = dccp_sk(sk);
 831         struct in6_addr *saddr = NULL, *final_p, final;
 832         struct flowi6 fl6;
 833         struct dst_entry *dst;
 834         int addr_type;
 835         int err;
 836
 837         dp->dccps_role = DCCP_ROLE_CLIENT;
 838
 839         if (addr_len < SIN6_LEN_RFC2133)
 840                 return -EINVAL;
 841
 842         if (usin->sin6_family != AF_INET6)
 843                 return -EAFNOSUPPORT;
 844
 845         memset(&fl6, 0, sizeof(fl6));
 846
 847         if (np->sndflow) {
 848                 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 849                 IP6_ECN_flow_init(fl6.flowlabel);
 850                 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
 851                         struct ip6_flowlabel *flowlabel;
 852                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 853                         if (flowlabel == NULL)
 854                                 return -EINVAL;
 855                         usin->sin6_addr = flowlabel->dst;
 856                         fl6_sock_release(flowlabel);
 857                 }
 858         }
 859         /*
 860          * connect() to INADDR_ANY means loopback (BSD'ism).
 861          */
 862         if (ipv6_addr_any(&usin->sin6_addr))
 863                 usin->sin6_addr.s6_addr[15] = 1;
 864
 865         addr_type = ipv6_addr_type(&usin->sin6_addr);
 866
 867         if (addr_type & IPV6_ADDR_MULTICAST)
 868                 return -ENETUNREACH;
 869
 870         if (addr_type & IPV6_ADDR_LINKLOCAL) {
 871                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 872                     usin->sin6_scope_id) {
 873                         /* If interface is set while binding, indices
 874                          * must coincide.
 875                          */
 876                         if (sk->sk_bound_dev_if &&
 877                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 878                                 return -EINVAL;
 879
 880                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 881                 }
 882
 883                 /* Connect to link-local address requires an interface */
 884                 if (!sk->sk_bound_dev_if)
 885                         return -EINVAL;
 886         }
 887
 888         np->daddr = usin->sin6_addr;
 889         np->flow_label = fl6.flowlabel;
 890
 891         /*
 892          * DCCP over IPv4
 893          */
 894         if (addr_type == IPV6_ADDR_MAPPED) {
 895                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 896                 struct sockaddr_in sin;
 897
 898                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 899
 900                 if (__ipv6_only_sock(sk))
 901                         return -ENETUNREACH;
 902
 903                 sin.sin_family = AF_INET;
 904                 sin.sin_port = usin->sin6_port;
 905                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 906
 907                 icsk->icsk_af_ops = &dccp_ipv6_mapped;
 908                 sk->sk_backlog_rcv = dccp_v4_do_rcv;
 909
 910                 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 911                 if (err) {
 912                         icsk->icsk_ext_hdr_len = exthdrlen;
 913                         icsk->icsk_af_ops = &dccp_ipv6_af_ops;
 914                         sk->sk_backlog_rcv = dccp_v6_do_rcv;
 915                         goto failure;
 916                 }
 917                 ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 918                 ipv6_addr_set_v4mapped(inet->inet_rcv_saddr, &np->rcv_saddr);
 919
 920                 return err;
 921         }
 922
 923         if (!ipv6_addr_any(&np->rcv_saddr))
 924                 saddr = &np->rcv_saddr;
 925
 926         fl6.flowi6_proto = IPPROTO_DCCP;
 927         fl6.daddr = np->daddr;
 928         fl6.saddr = saddr ? *saddr : np->saddr;
 929         fl6.flowi6_oif = sk->sk_bound_dev_if;
 930         fl6.fl6_dport = usin->sin6_port;
 931         fl6.fl6_sport = inet->inet_sport;
 932         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 933
 934         final_p = fl6_update_dst(&fl6, np->opt, &final);
 935
 936         dst = ip6_dst_lookup_flow(sk, &fl6, final_p, true);
 937         if (IS_ERR(dst)) {
 938                 err = PTR_ERR(dst);
 939                 goto failure;
 940         }
 941
 942         if (saddr == NULL) {
 943                 saddr = &fl6.saddr;
 944                 np->rcv_saddr = *saddr;
 945         }
 946
 947         /* set the source address */
 948         np->saddr = *saddr;
 949         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 950
 951         __ip6_dst_store(sk, dst, NULL, NULL);
 952
 953         icsk->icsk_ext_hdr_len = 0;
 954         if (np->opt != NULL)
 955                 icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
 956                                           np->opt->opt_nflen);
 957
 958         inet->inet_dport = usin->sin6_port;
 959
 960         dccp_set_state(sk, DCCP_REQUESTING);
 961         err = inet6_hash_connect(&dccp_death_row, sk);
 962         if (err)
 963                 goto late_failure;
 964
 965         dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
 966                                                       np->daddr.s6_addr32,
 967                                                       inet->inet_sport,
 968                                                       inet->inet_dport);
 969         err = dccp_connect(sk);
 970         if (err)
 971                 goto late_failure;
 972
 973         return 0;
 974
 975 late_failure:
 976         dccp_set_state(sk, DCCP_CLOSED);
 977         __sk_dst_reset(sk);
 978 failure:
 979         inet->inet_dport = 0;
 980         sk->sk_route_caps = 0;
 981         return err;
 982 }
 983
 984 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
 985         .queue_xmit        = inet6_csk_xmit,
 986         .send_check        = dccp_v6_send_check,
 987         .rebuild_header    = inet6_sk_rebuild_header,
 988         .conn_request      = dccp_v6_conn_request,
 989         .syn_recv_sock     = dccp_v6_request_recv_sock,
 990         .net_header_len    = sizeof(struct ipv6hdr),
 991         .setsockopt        = ipv6_setsockopt,
 992         .getsockopt        = ipv6_getsockopt,
 993         .addr2sockaddr     = inet6_csk_addr2sockaddr,
 994         .sockaddr_len      = sizeof(struct sockaddr_in6),
 995         .bind_conflict     = inet6_csk_bind_conflict,
 996 #ifdef CONFIG_COMPAT
 997         .compat_setsockopt = compat_ipv6_setsockopt,
 998         .compat_getsockopt = compat_ipv6_getsockopt,
 999 #endif
1000 };
1001
1002 /*
1003  *      DCCP over IPv4 via INET6 API
1004  */
1005 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
1006         .queue_xmit        = ip_queue_xmit,
1007         .send_check        = dccp_v4_send_check,
1008         .rebuild_header    = inet_sk_rebuild_header,
1009         .conn_request      = dccp_v6_conn_request,
1010         .syn_recv_sock     = dccp_v6_request_recv_sock,
1011         .net_header_len    = sizeof(struct iphdr),
1012         .setsockopt        = ipv6_setsockopt,
1013         .getsockopt        = ipv6_getsockopt,
1014         .addr2sockaddr     = inet6_csk_addr2sockaddr,
1015         .sockaddr_len      = sizeof(struct sockaddr_in6),
1016 #ifdef CONFIG_COMPAT
1017         .compat_setsockopt = compat_ipv6_setsockopt,
1018         .compat_getsockopt = compat_ipv6_getsockopt,
1019 #endif
1020 };
1021
1022 /* NOTE: A lot of things set to zero explicitly by call to
1023  *       sk_alloc() so need not be done here.
1024  */
1025 static int dccp_v6_init_sock(struct sock *sk)
1026 {
1027         static __u8 dccp_v6_ctl_sock_initialized;
1028         int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
1029
1030         if (err == 0) {
1031                 if (unlikely(!dccp_v6_ctl_sock_initialized))
1032                         dccp_v6_ctl_sock_initialized = 1;
1033                 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1034         }
1035
1036         return err;
1037 }
1038
1039 static void dccp_v6_destroy_sock(struct sock *sk)
1040 {
1041         dccp_destroy_sock(sk);
1042         inet6_destroy_sock(sk);
1043 }
1044
1045 static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1046         .twsk_obj_size  = sizeof(struct dccp6_timewait_sock),
1047 };
1048
1049 static struct proto dccp_v6_prot = {
1050         .name              = "DCCPv6",
1051         .owner             = THIS_MODULE,
1052         .close             = dccp_close,
1053         .connect           = dccp_v6_connect,
1054         .disconnect        = dccp_disconnect,
1055         .ioctl             = dccp_ioctl,
1056         .init              = dccp_v6_init_sock,
1057         .setsockopt        = dccp_setsockopt,
1058         .getsockopt        = dccp_getsockopt,
1059         .sendmsg           = dccp_sendmsg,
1060         .recvmsg           = dccp_recvmsg,
1061         .backlog_rcv       = dccp_v6_do_rcv,
1062         .hash              = dccp_v6_hash,
1063         .unhash            = inet_unhash,
1064         .accept            = inet_csk_accept,
1065         .get_port          = inet_csk_get_port,
1066         .shutdown          = dccp_shutdown,
1067         .destroy           = dccp_v6_destroy_sock,
1068         .orphan_count      = &dccp_orphan_count,
1069         .max_header        = MAX_DCCP_HEADER,
1070         .obj_size          = sizeof(struct dccp6_sock),
1071         .slab_flags        = SLAB_DESTROY_BY_RCU,
1072         .rsk_prot          = &dccp6_request_sock_ops,
1073         .twsk_prot         = &dccp6_timewait_sock_ops,
1074         .h.hashinfo        = &dccp_hashinfo,
1075 #ifdef CONFIG_COMPAT
1076         .compat_setsockopt = compat_dccp_setsockopt,
1077         .compat_getsockopt = compat_dccp_getsockopt,
1078 #endif
1079 };
1080
1081 static const struct inet6_protocol dccp_v6_protocol = {
1082         .handler        = dccp_v6_rcv,
1083         .err_handler    = dccp_v6_err,
1084         .flags          = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1085 };
1086
1087 static const struct proto_ops inet6_dccp_ops = {
1088         .family            = PF_INET6,
1089         .owner             = THIS_MODULE,
1090         .release           = inet6_release,
1091         .bind              = inet6_bind,
1092         .connect           = inet_stream_connect,
1093         .socketpair        = sock_no_socketpair,
1094         .accept            = inet_accept,
1095         .getname           = inet6_getname,
1096         .poll              = dccp_poll,
1097         .ioctl             = inet6_ioctl,
1098         .listen            = inet_dccp_listen,
1099         .shutdown          = inet_shutdown,
1100         .setsockopt        = sock_common_setsockopt,
1101         .getsockopt        = sock_common_getsockopt,
1102         .sendmsg           = inet_sendmsg,
1103         .recvmsg           = sock_common_recvmsg,
1104         .mmap              = sock_no_mmap,
1105         .sendpage          = sock_no_sendpage,
1106 #ifdef CONFIG_COMPAT
1107         .compat_setsockopt = compat_sock_common_setsockopt,
1108         .compat_getsockopt = compat_sock_common_getsockopt,
1109 #endif
1110 };
1111
1112 static struct inet_protosw dccp_v6_protosw = {
1113         .type           = SOCK_DCCP,
1114         .protocol       = IPPROTO_DCCP,
1115         .prot           = &dccp_v6_prot,
1116         .ops            = &inet6_dccp_ops,
1117         .flags          = INET_PROTOSW_ICSK,
1118 };
1119
1120 static int __net_init dccp_v6_init_net(struct net *net)
1121 {
1122         if (dccp_hashinfo.bhash == NULL)
1123                 return -ESOCKTNOSUPPORT;
1124
1125         return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6,
1126                                     SOCK_DCCP, IPPROTO_DCCP, net);
1127 }
1128
1129 static void __net_exit dccp_v6_exit_net(struct net *net)
1130 {
1131         inet_ctl_sock_destroy(net->dccp.v6_ctl_sk);
1132 }
1133
1134 static struct pernet_operations dccp_v6_ops = {
1135         .init   = dccp_v6_init_net,
1136         .exit   = dccp_v6_exit_net,
1137 };
1138
1139 static int __init dccp_v6_init(void)
1140 {
1141         int err = proto_register(&dccp_v6_prot, 1);
1142
1143         if (err != 0)
1144                 goto out;
1145
1146         err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1147         if (err != 0)
1148                 goto out_unregister_proto;
1149
1150         inet6_register_protosw(&dccp_v6_protosw);
1151
1152         err = register_pernet_subsys(&dccp_v6_ops);
1153         if (err != 0)
1154                 goto out_destroy_ctl_sock;
1155 out:
1156         return err;
1157
1158 out_destroy_ctl_sock:
1159         inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1160         inet6_unregister_protosw(&dccp_v6_protosw);
1161 out_unregister_proto:
1162         proto_unregister(&dccp_v6_prot);
1163         goto out;
1164 }
1165
1166 static void __exit dccp_v6_exit(void)
1167 {
1168         unregister_pernet_subsys(&dccp_v6_ops);
1169         inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1170         inet6_unregister_protosw(&dccp_v6_protosw);
1171         proto_unregister(&dccp_v6_prot);
1172 }
1173
1174 module_init(dccp_v6_init);
1175 module_exit(dccp_v6_exit);
1176
1177 /*
1178  * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1179  * values directly, Also cover the case where the protocol is not specified,
1180  * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1181  */
1182 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1183 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1184 MODULE_LICENSE("GPL");
1185 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1186 MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");