net/dccp/ipv6.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
dccp_v6_csum_finish
dccp_v6_send_check
dccp_v6_init_sequence
dccp_v6_err
dccp_v6_send_response
dccp_v6_reqsk_destructor
dccp_v6_ctl_send_reset
dccp_v6_conn_request
dccp_v6_request_recv_sock
dccp_v6_do_rcv
dccp_v6_rcv
dccp_v6_connect
dccp_v6_init_sock
dccp_v6_destroy_sock
dccp_v6_init_net
dccp_v6_exit_net
dccp_v6_exit_batch
dccp_v6_init
dccp_v6_exit
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      DCCP over IPv6
   4  *      Linux INET6 implementation
   5  *
   6  *      Based on net/dccp6/ipv6.c
   7  *
   8  *      Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
   9  */
  10 
  11 #include <linux/module.h>
  12 #include <linux/random.h>
  13 #include <linux/slab.h>
  14 #include <linux/xfrm.h>
  15 #include <linux/string.h>
  16 
  17 #include <net/addrconf.h>
  18 #include <net/inet_common.h>
  19 #include <net/inet_hashtables.h>
  20 #include <net/inet_sock.h>
  21 #include <net/inet6_connection_sock.h>
  22 #include <net/inet6_hashtables.h>
  23 #include <net/ip6_route.h>
  24 #include <net/ipv6.h>
  25 #include <net/protocol.h>
  26 #include <net/transp_v6.h>
  27 #include <net/ip6_checksum.h>
  28 #include <net/xfrm.h>
  29 #include <net/secure_seq.h>
  30 #include <net/sock.h>
  31 
  32 #include "dccp.h"
  33 #include "ipv6.h"
  34 #include "feat.h"
  35 
  36 /* The per-net dccp.v6_ctl_sk is used for sending RSTs and ACKs */
  37 
  38 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped;
  39 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops;
  40 
  41 /* add pseudo-header to DCCP checksum stored in skb->csum */
  42 static inline __sum16 dccp_v6_csum_finish(struct sk_buff *skb,
  43                                       const struct in6_addr *saddr,
  44                                       const struct in6_addr *daddr)
  45 {
  46         return csum_ipv6_magic(saddr, daddr, skb->len, IPPROTO_DCCP, skb->csum);
  47 }
  48 
  49 static inline void dccp_v6_send_check(struct sock *sk, struct sk_buff *skb)
  50 {
  51         struct ipv6_pinfo *np = inet6_sk(sk);
  52         struct dccp_hdr *dh = dccp_hdr(skb);
  53 
  54         dccp_csum_outgoing(skb);
  55         dh->dccph_checksum = dccp_v6_csum_finish(skb, &np->saddr, &sk->sk_v6_daddr);
  56 }
  57 
  58 static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
  59 {
  60         return secure_dccpv6_sequence_number(ipv6_hdr(skb)->daddr.s6_addr32,
  61                                              ipv6_hdr(skb)->saddr.s6_addr32,
  62                                              dccp_hdr(skb)->dccph_dport,
  63                                              dccp_hdr(skb)->dccph_sport     );
  64 
  65 }
  66 
  67 static int dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
  68                         u8 type, u8 code, int offset, __be32 info)
  69 {
  70         const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
  71         const struct dccp_hdr *dh;
  72         struct dccp_sock *dp;
  73         struct ipv6_pinfo *np;
  74         struct sock *sk;
  75         int err;
  76         __u64 seq;
  77         struct net *net = dev_net(skb->dev);
  78 
  79         /* Only need dccph_dport & dccph_sport which are the first
  80          * 4 bytes in dccp header.
  81          * Our caller (icmpv6_notify()) already pulled 8 bytes for us.
  82          */
  83         BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_sport) > 8);
  84         BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_dport) > 8);
  85         dh = (struct dccp_hdr *)(skb->data + offset);
  86 
  87         sk = __inet6_lookup_established(net, &dccp_hashinfo,
  88                                         &hdr->daddr, dh->dccph_dport,
  89                                         &hdr->saddr, ntohs(dh->dccph_sport),
  90                                         inet6_iif(skb), 0);
  91 
  92         if (!sk) {
  93                 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
  94                                   ICMP6_MIB_INERRORS);
  95                 return -ENOENT;
  96         }
  97 
  98         if (sk->sk_state == DCCP_TIME_WAIT) {
  99                 inet_twsk_put(inet_twsk(sk));
 100                 return 0;
 101         }
 102         seq = dccp_hdr_seq(dh);
 103         if (sk->sk_state == DCCP_NEW_SYN_RECV) {
 104                 dccp_req_err(sk, seq);
 105                 return 0;
 106         }
 107 
 108         bh_lock_sock(sk);
 109         if (sock_owned_by_user(sk))
 110                 __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
 111 
 112         if (sk->sk_state == DCCP_CLOSED)
 113                 goto out;
 114 
 115         dp = dccp_sk(sk);
 116         if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
 117             !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
 118                 __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
 119                 goto out;
 120         }
 121 
 122         np = inet6_sk(sk);
 123 
 124         if (type == NDISC_REDIRECT) {
 125                 if (!sock_owned_by_user(sk)) {
 126                         struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 127 
 128                         if (dst)
 129                                 dst->ops->redirect(dst, sk, skb);
 130                 }
 131                 goto out;
 132         }
 133 
 134         if (type == ICMPV6_PKT_TOOBIG) {
 135                 struct dst_entry *dst = NULL;
 136 
 137                 if (!ip6_sk_accept_pmtu(sk))
 138                         goto out;
 139 
 140                 if (sock_owned_by_user(sk))
 141                         goto out;
 142                 if ((1 << sk->sk_state) & (DCCPF_LISTEN | DCCPF_CLOSED))
 143                         goto out;
 144 
 145                 dst = inet6_csk_update_pmtu(sk, ntohl(info));
 146                 if (!dst)
 147                         goto out;
 148 
 149                 if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst))
 150                         dccp_sync_mss(sk, dst_mtu(dst));
 151                 goto out;
 152         }
 153 
 154         icmpv6_err_convert(type, code, &err);
 155 
 156         /* Might be for an request_sock */
 157         switch (sk->sk_state) {
 158         case DCCP_REQUESTING:
 159         case DCCP_RESPOND:  /* Cannot happen.
 160                                It can, it SYNs are crossed. --ANK */
 161                 if (!sock_owned_by_user(sk)) {
 162                         __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
 163                         sk->sk_err = err;
 164                         /*
 165                          * Wake people up to see the error
 166                          * (see connect in sock.c)
 167                          */
 168                         sk->sk_error_report(sk);
 169                         dccp_done(sk);
 170                 } else
 171                         sk->sk_err_soft = err;
 172                 goto out;
 173         }
 174 
 175         if (!sock_owned_by_user(sk) && np->recverr) {
 176                 sk->sk_err = err;
 177                 sk->sk_error_report(sk);
 178         } else
 179                 sk->sk_err_soft = err;
 180 
 181 out:
 182         bh_unlock_sock(sk);
 183         sock_put(sk);
 184         return 0;
 185 }
 186 
 187 
 188 static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req)
 189 {
 190         struct inet_request_sock *ireq = inet_rsk(req);
 191         struct ipv6_pinfo *np = inet6_sk(sk);
 192         struct sk_buff *skb;
 193         struct in6_addr *final_p, final;
 194         struct flowi6 fl6;
 195         int err = -1;
 196         struct dst_entry *dst;
 197 
 198         memset(&fl6, 0, sizeof(fl6));
 199         fl6.flowi6_proto = IPPROTO_DCCP;
 200         fl6.daddr = ireq->ir_v6_rmt_addr;
 201         fl6.saddr = ireq->ir_v6_loc_addr;
 202         fl6.flowlabel = 0;
 203         fl6.flowi6_oif = ireq->ir_iif;
 204         fl6.fl6_dport = ireq->ir_rmt_port;
 205         fl6.fl6_sport = htons(ireq->ir_num);
 206         security_req_classify_flow(req, flowi6_to_flowi(&fl6));
 207 
 208 
 209         rcu_read_lock();
 210         final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
 211         rcu_read_unlock();
 212 
 213         dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
 214         if (IS_ERR(dst)) {
 215                 err = PTR_ERR(dst);
 216                 dst = NULL;
 217                 goto done;
 218         }
 219 
 220         skb = dccp_make_response(sk, dst, req);
 221         if (skb != NULL) {
 222                 struct dccp_hdr *dh = dccp_hdr(skb);
 223                 struct ipv6_txoptions *opt;
 224 
 225                 dh->dccph_checksum = dccp_v6_csum_finish(skb,
 226                                                          &ireq->ir_v6_loc_addr,
 227                                                          &ireq->ir_v6_rmt_addr);
 228                 fl6.daddr = ireq->ir_v6_rmt_addr;
 229                 rcu_read_lock();
 230                 opt = ireq->ipv6_opt;
 231                 if (!opt)
 232                         opt = rcu_dereference(np->opt);
 233                 err = ip6_xmit(sk, skb, &fl6, sk->sk_mark, opt, np->tclass,
 234                                sk->sk_priority);
 235                 rcu_read_unlock();
 236                 err = net_xmit_eval(err);
 237         }
 238 
 239 done:
 240         dst_release(dst);
 241         return err;
 242 }
 243 
 244 static void dccp_v6_reqsk_destructor(struct request_sock *req)
 245 {
 246         dccp_feat_list_purge(&dccp_rsk(req)->dreq_featneg);
 247         kfree(inet_rsk(req)->ipv6_opt);
 248         kfree_skb(inet_rsk(req)->pktopts);
 249 }
 250 
 251 static void dccp_v6_ctl_send_reset(const struct sock *sk, struct sk_buff *rxskb)
 252 {
 253         const struct ipv6hdr *rxip6h;
 254         struct sk_buff *skb;
 255         struct flowi6 fl6;
 256         struct net *net = dev_net(skb_dst(rxskb)->dev);
 257         struct sock *ctl_sk = net->dccp.v6_ctl_sk;
 258         struct dst_entry *dst;
 259 
 260         if (dccp_hdr(rxskb)->dccph_type == DCCP_PKT_RESET)
 261                 return;
 262 
 263         if (!ipv6_unicast_destination(rxskb))
 264                 return;
 265 
 266         skb = dccp_ctl_make_reset(ctl_sk, rxskb);
 267         if (skb == NULL)
 268                 return;
 269 
 270         rxip6h = ipv6_hdr(rxskb);
 271         dccp_hdr(skb)->dccph_checksum = dccp_v6_csum_finish(skb, &rxip6h->saddr,
 272                                                             &rxip6h->daddr);
 273 
 274         memset(&fl6, 0, sizeof(fl6));
 275         fl6.daddr = rxip6h->saddr;
 276         fl6.saddr = rxip6h->daddr;
 277 
 278         fl6.flowi6_proto = IPPROTO_DCCP;
 279         fl6.flowi6_oif = inet6_iif(rxskb);
 280         fl6.fl6_dport = dccp_hdr(skb)->dccph_dport;
 281         fl6.fl6_sport = dccp_hdr(skb)->dccph_sport;
 282         security_skb_classify_flow(rxskb, flowi6_to_flowi(&fl6));
 283 
 284         /* sk = NULL, but it is safe for now. RST socket required. */
 285         dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL);
 286         if (!IS_ERR(dst)) {
 287                 skb_dst_set(skb, dst);
 288                 ip6_xmit(ctl_sk, skb, &fl6, 0, NULL, 0, 0);
 289                 DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
 290                 DCCP_INC_STATS(DCCP_MIB_OUTRSTS);
 291                 return;
 292         }
 293 
 294         kfree_skb(skb);
 295 }
 296 
 297 static struct request_sock_ops dccp6_request_sock_ops = {
 298         .family         = AF_INET6,
 299         .obj_size       = sizeof(struct dccp6_request_sock),
 300         .rtx_syn_ack    = dccp_v6_send_response,
 301         .send_ack       = dccp_reqsk_send_ack,
 302         .destructor     = dccp_v6_reqsk_destructor,
 303         .send_reset     = dccp_v6_ctl_send_reset,
 304         .syn_ack_timeout = dccp_syn_ack_timeout,
 305 };
 306 
 307 static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 308 {
 309         struct request_sock *req;
 310         struct dccp_request_sock *dreq;
 311         struct inet_request_sock *ireq;
 312         struct ipv6_pinfo *np = inet6_sk(sk);
 313         const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
 314         struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
 315 
 316         if (skb->protocol == htons(ETH_P_IP))
 317                 return dccp_v4_conn_request(sk, skb);
 318 
 319         if (!ipv6_unicast_destination(skb))
 320                 return 0;       /* discard, don't send a reset here */
 321 
 322         if (dccp_bad_service_code(sk, service)) {
 323                 dcb->dccpd_reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
 324                 goto drop;
 325         }
 326         /*
 327          * There are no SYN attacks on IPv6, yet...
 328          */
 329         dcb->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;
 330         if (inet_csk_reqsk_queue_is_full(sk))
 331                 goto drop;
 332 
 333         if (sk_acceptq_is_full(sk))
 334                 goto drop;
 335 
 336         req = inet_reqsk_alloc(&dccp6_request_sock_ops, sk, true);
 337         if (req == NULL)
 338                 goto drop;
 339 
 340         if (dccp_reqsk_init(req, dccp_sk(sk), skb))
 341                 goto drop_and_free;
 342 
 343         dreq = dccp_rsk(req);
 344         if (dccp_parse_options(sk, dreq, skb))
 345                 goto drop_and_free;
 346 
 347         if (security_inet_conn_request(sk, skb, req))
 348                 goto drop_and_free;
 349 
 350         ireq = inet_rsk(req);
 351         ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 352         ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 353         ireq->ireq_family = AF_INET6;
 354         ireq->ir_mark = inet_request_mark(sk, skb);
 355 
 356         if (ipv6_opt_accepted(sk, skb, IP6CB(skb)) ||
 357             np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
 358             np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
 359                 refcount_inc(&skb->users);
 360                 ireq->pktopts = skb;
 361         }
 362         ireq->ir_iif = sk->sk_bound_dev_if;
 363 
 364         /* So that link locals have meaning */
 365         if (!sk->sk_bound_dev_if &&
 366             ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 367                 ireq->ir_iif = inet6_iif(skb);
 368 
 369         /*
 370          * Step 3: Process LISTEN state
 371          *
 372          *   Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
 373          *
 374          * Setting S.SWL/S.SWH to is deferred to dccp_create_openreq_child().
 375          */
 376         dreq->dreq_isr     = dcb->dccpd_seq;
 377         dreq->dreq_gsr     = dreq->dreq_isr;
 378         dreq->dreq_iss     = dccp_v6_init_sequence(skb);
 379         dreq->dreq_gss     = dreq->dreq_iss;
 380         dreq->dreq_service = service;
 381 
 382         if (dccp_v6_send_response(sk, req))
 383                 goto drop_and_free;
 384 
 385         inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
 386         reqsk_put(req);
 387         return 0;
 388 
 389 drop_and_free:
 390         reqsk_free(req);
 391 drop:
 392         __DCCP_INC_STATS(DCCP_MIB_ATTEMPTFAILS);
 393         return -1;
 394 }
 395 
 396 static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
 397                                               struct sk_buff *skb,
 398                                               struct request_sock *req,
 399                                               struct dst_entry *dst,
 400                                               struct request_sock *req_unhash,
 401                                               bool *own_req)
 402 {
 403         struct inet_request_sock *ireq = inet_rsk(req);
 404         struct ipv6_pinfo *newnp;
 405         const struct ipv6_pinfo *np = inet6_sk(sk);
 406         struct ipv6_txoptions *opt;
 407         struct inet_sock *newinet;
 408         struct dccp6_sock *newdp6;
 409         struct sock *newsk;
 410 
 411         if (skb->protocol == htons(ETH_P_IP)) {
 412                 /*
 413                  *      v6 mapped
 414                  */
 415                 newsk = dccp_v4_request_recv_sock(sk, skb, req, dst,
 416                                                   req_unhash, own_req);
 417                 if (newsk == NULL)
 418                         return NULL;
 419 
 420                 newdp6 = (struct dccp6_sock *)newsk;
 421                 newinet = inet_sk(newsk);
 422                 newinet->pinet6 = &newdp6->inet6;
 423                 newnp = inet6_sk(newsk);
 424 
 425                 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 426 
 427                 newnp->saddr = newsk->sk_v6_rcv_saddr;
 428 
 429                 inet_csk(newsk)->icsk_af_ops = &dccp_ipv6_mapped;
 430                 newsk->sk_backlog_rcv = dccp_v4_do_rcv;
 431                 newnp->pktoptions  = NULL;
 432                 newnp->opt         = NULL;
 433                 newnp->ipv6_mc_list = NULL;
 434                 newnp->ipv6_ac_list = NULL;
 435                 newnp->ipv6_fl_list = NULL;
 436                 newnp->mcast_oif   = inet_iif(skb);
 437                 newnp->mcast_hops  = ip_hdr(skb)->ttl;
 438 
 439                 /*
 440                  * No need to charge this sock to the relevant IPv6 refcnt debug socks count
 441                  * here, dccp_create_openreq_child now does this for us, see the comment in
 442                  * that function for the gory details. -acme
 443                  */
 444 
 445                 /* It is tricky place. Until this moment IPv4 tcp
 446                    worked with IPv6 icsk.icsk_af_ops.
 447                    Sync it now.
 448                  */
 449                 dccp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
 450 
 451                 return newsk;
 452         }
 453 
 454 
 455         if (sk_acceptq_is_full(sk))
 456                 goto out_overflow;
 457 
 458         if (!dst) {
 459                 struct flowi6 fl6;
 460 
 461                 dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_DCCP);
 462                 if (!dst)
 463                         goto out;
 464         }
 465 
 466         newsk = dccp_create_openreq_child(sk, req, skb);
 467         if (newsk == NULL)
 468                 goto out_nonewsk;
 469 
 470         /*
 471          * No need to charge this sock to the relevant IPv6 refcnt debug socks
 472          * count here, dccp_create_openreq_child now does this for us, see the
 473          * comment in that function for the gory details. -acme
 474          */
 475 
 476         ip6_dst_store(newsk, dst, NULL, NULL);
 477         newsk->sk_route_caps = dst->dev->features & ~(NETIF_F_IP_CSUM |
 478                                                       NETIF_F_TSO);
 479         newdp6 = (struct dccp6_sock *)newsk;
 480         newinet = inet_sk(newsk);
 481         newinet->pinet6 = &newdp6->inet6;
 482         newnp = inet6_sk(newsk);
 483 
 484         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 485 
 486         newsk->sk_v6_daddr      = ireq->ir_v6_rmt_addr;
 487         newnp->saddr            = ireq->ir_v6_loc_addr;
 488         newsk->sk_v6_rcv_saddr  = ireq->ir_v6_loc_addr;
 489         newsk->sk_bound_dev_if  = ireq->ir_iif;
 490 
 491         /* Now IPv6 options...
 492 
 493            First: no IPv4 options.
 494          */
 495         newinet->inet_opt = NULL;
 496 
 497         /* Clone RX bits */
 498         newnp->rxopt.all = np->rxopt.all;
 499 
 500         newnp->ipv6_mc_list = NULL;
 501         newnp->ipv6_ac_list = NULL;
 502         newnp->ipv6_fl_list = NULL;
 503         newnp->pktoptions = NULL;
 504         newnp->opt        = NULL;
 505         newnp->mcast_oif  = inet6_iif(skb);
 506         newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
 507 
 508         /*
 509          * Clone native IPv6 options from listening socket (if any)
 510          *
 511          * Yes, keeping reference count would be much more clever, but we make
 512          * one more one thing there: reattach optmem to newsk.
 513          */
 514         opt = ireq->ipv6_opt;
 515         if (!opt)
 516                 opt = rcu_dereference(np->opt);
 517         if (opt) {
 518                 opt = ipv6_dup_options(newsk, opt);
 519                 RCU_INIT_POINTER(newnp->opt, opt);
 520         }
 521         inet_csk(newsk)->icsk_ext_hdr_len = 0;
 522         if (opt)
 523                 inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
 524                                                     opt->opt_flen;
 525 
 526         dccp_sync_mss(newsk, dst_mtu(dst));
 527 
 528         newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
 529         newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
 530 
 531         if (__inet_inherit_port(sk, newsk) < 0) {
 532                 inet_csk_prepare_forced_close(newsk);
 533                 dccp_done(newsk);
 534                 goto out;
 535         }
 536         *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash));
 537         /* Clone pktoptions received with SYN, if we own the req */
 538         if (*own_req && ireq->pktopts) {
 539                 newnp->pktoptions = skb_clone(ireq->pktopts, GFP_ATOMIC);
 540                 consume_skb(ireq->pktopts);
 541                 ireq->pktopts = NULL;
 542                 if (newnp->pktoptions)
 543                         skb_set_owner_r(newnp->pktoptions, newsk);
 544         }
 545 
 546         return newsk;
 547 
 548 out_overflow:
 549         __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
 550 out_nonewsk:
 551         dst_release(dst);
 552 out:
 553         __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS);
 554         return NULL;
 555 }
 556 
 557 /* The socket must have it's spinlock held when we get
 558  * here.
 559  *
 560  * We have a potential double-lock case here, so even when
 561  * doing backlog processing we use the BH locking scheme.
 562  * This is because we cannot sleep with the original spinlock
 563  * held.
 564  */
 565 static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 566 {
 567         struct ipv6_pinfo *np = inet6_sk(sk);
 568         struct sk_buff *opt_skb = NULL;
 569 
 570         /* Imagine: socket is IPv6. IPv4 packet arrives,
 571            goes to IPv4 receive handler and backlogged.
 572            From backlog it always goes here. Kerboom...
 573            Fortunately, dccp_rcv_established and rcv_established
 574            handle them correctly, but it is not case with
 575            dccp_v6_hnd_req and dccp_v6_ctl_send_reset().   --ANK
 576          */
 577 
 578         if (skb->protocol == htons(ETH_P_IP))
 579                 return dccp_v4_do_rcv(sk, skb);
 580 
 581         if (sk_filter(sk, skb))
 582                 goto discard;
 583 
 584         /*
 585          * socket locking is here for SMP purposes as backlog rcv is currently
 586          * called with bh processing disabled.
 587          */
 588 
 589         /* Do Stevens' IPV6_PKTOPTIONS.
 590 
 591            Yes, guys, it is the only place in our code, where we
 592            may make it not affecting IPv4.
 593            The rest of code is protocol independent,
 594            and I do not like idea to uglify IPv4.
 595 
 596            Actually, all the idea behind IPV6_PKTOPTIONS
 597            looks not very well thought. For now we latch
 598            options, received in the last packet, enqueued
 599            by tcp. Feel free to propose better solution.
 600                                                --ANK (980728)
 601          */
 602         if (np->rxopt.all)
 603                 opt_skb = skb_clone(skb, GFP_ATOMIC);
 604 
 605         if (sk->sk_state == DCCP_OPEN) { /* Fast path */
 606                 if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
 607                         goto reset;
 608                 if (opt_skb)
 609                         goto ipv6_pktoptions;
 610                 return 0;
 611         }
 612 
 613         /*
 614          *  Step 3: Process LISTEN state
 615          *     If S.state == LISTEN,
 616          *       If P.type == Request or P contains a valid Init Cookie option,
 617          *            (* Must scan the packet's options to check for Init
 618          *               Cookies.  Only Init Cookies are processed here,
 619          *               however; other options are processed in Step 8.  This
 620          *               scan need only be performed if the endpoint uses Init
 621          *               Cookies *)
 622          *            (* Generate a new socket and switch to that socket *)
 623          *            Set S := new socket for this port pair
 624          *            S.state = RESPOND
 625          *            Choose S.ISS (initial seqno) or set from Init Cookies
 626          *            Initialize S.GAR := S.ISS
 627          *            Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
 628          *            Continue with S.state == RESPOND
 629          *            (* A Response packet will be generated in Step 11 *)
 630          *       Otherwise,
 631          *            Generate Reset(No Connection) unless P.type == Reset
 632          *            Drop packet and return
 633          *
 634          * NOTE: the check for the packet types is done in
 635          *       dccp_rcv_state_process
 636          */
 637 
 638         if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
 639                 goto reset;
 640         if (opt_skb)
 641                 goto ipv6_pktoptions;
 642         return 0;
 643 
 644 reset:
 645         dccp_v6_ctl_send_reset(sk, skb);
 646 discard:
 647         if (opt_skb != NULL)
 648                 __kfree_skb(opt_skb);
 649         kfree_skb(skb);
 650         return 0;
 651 
 652 /* Handling IPV6_PKTOPTIONS skb the similar
 653  * way it's done for net/ipv6/tcp_ipv6.c
 654  */
 655 ipv6_pktoptions:
 656         if (!((1 << sk->sk_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) {
 657                 if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
 658                         np->mcast_oif = inet6_iif(opt_skb);
 659                 if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
 660                         np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
 661                 if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
 662                         np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
 663                 if (np->repflow)
 664                         np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
 665                 if (ipv6_opt_accepted(sk, opt_skb,
 666                                       &DCCP_SKB_CB(opt_skb)->header.h6)) {
 667                         skb_set_owner_r(opt_skb, sk);
 668                         memmove(IP6CB(opt_skb),
 669                                 &DCCP_SKB_CB(opt_skb)->header.h6,
 670                                 sizeof(struct inet6_skb_parm));
 671                         opt_skb = xchg(&np->pktoptions, opt_skb);
 672                 } else {
 673                         __kfree_skb(opt_skb);
 674                         opt_skb = xchg(&np->pktoptions, NULL);
 675                 }
 676         }
 677 
 678         kfree_skb(opt_skb);
 679         return 0;
 680 }
 681 
 682 static int dccp_v6_rcv(struct sk_buff *skb)
 683 {
 684         const struct dccp_hdr *dh;
 685         bool refcounted;
 686         struct sock *sk;
 687         int min_cov;
 688 
 689         /* Step 1: Check header basics */
 690 
 691         if (dccp_invalid_packet(skb))
 692                 goto discard_it;
 693 
 694         /* Step 1: If header checksum is incorrect, drop packet and return. */
 695         if (dccp_v6_csum_finish(skb, &ipv6_hdr(skb)->saddr,
 696                                      &ipv6_hdr(skb)->daddr)) {
 697                 DCCP_WARN("dropped packet with invalid checksum\n");
 698                 goto discard_it;
 699         }
 700 
 701         dh = dccp_hdr(skb);
 702 
 703         DCCP_SKB_CB(skb)->dccpd_seq  = dccp_hdr_seq(dh);
 704         DCCP_SKB_CB(skb)->dccpd_type = dh->dccph_type;
 705 
 706         if (dccp_packet_without_ack(skb))
 707                 DCCP_SKB_CB(skb)->dccpd_ack_seq = DCCP_PKT_WITHOUT_ACK_SEQ;
 708         else
 709                 DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
 710 
 711 lookup:
 712         sk = __inet6_lookup_skb(&dccp_hashinfo, skb, __dccp_hdr_len(dh),
 713                                 dh->dccph_sport, dh->dccph_dport,
 714                                 inet6_iif(skb), 0, &refcounted);
 715         if (!sk) {
 716                 dccp_pr_debug("failed to look up flow ID in table and "
 717                               "get corresponding socket\n");
 718                 goto no_dccp_socket;
 719         }
 720 
 721         /*
 722          * Step 2:
 723          *      ... or S.state == TIMEWAIT,
 724          *              Generate Reset(No Connection) unless P.type == Reset
 725          *              Drop packet and return
 726          */
 727         if (sk->sk_state == DCCP_TIME_WAIT) {
 728                 dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
 729                 inet_twsk_put(inet_twsk(sk));
 730                 goto no_dccp_socket;
 731         }
 732 
 733         if (sk->sk_state == DCCP_NEW_SYN_RECV) {
 734                 struct request_sock *req = inet_reqsk(sk);
 735                 struct sock *nsk;
 736 
 737                 sk = req->rsk_listener;
 738                 if (unlikely(sk->sk_state != DCCP_LISTEN)) {
 739                         inet_csk_reqsk_queue_drop_and_put(sk, req);
 740                         goto lookup;
 741                 }
 742                 sock_hold(sk);
 743                 refcounted = true;
 744                 nsk = dccp_check_req(sk, skb, req);
 745                 if (!nsk) {
 746                         reqsk_put(req);
 747                         goto discard_and_relse;
 748                 }
 749                 if (nsk == sk) {
 750                         reqsk_put(req);
 751                 } else if (dccp_child_process(sk, nsk, skb)) {
 752                         dccp_v6_ctl_send_reset(sk, skb);
 753                         goto discard_and_relse;
 754                 } else {
 755                         sock_put(sk);
 756                         return 0;
 757                 }
 758         }
 759         /*
 760          * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
 761          *      o if MinCsCov = 0, only packets with CsCov = 0 are accepted
 762          *      o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
 763          */
 764         min_cov = dccp_sk(sk)->dccps_pcrlen;
 765         if (dh->dccph_cscov  &&  (min_cov == 0 || dh->dccph_cscov < min_cov))  {
 766                 dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
 767                               dh->dccph_cscov, min_cov);
 768                 /* FIXME: send Data Dropped option (see also dccp_v4_rcv) */
 769                 goto discard_and_relse;
 770         }
 771 
 772         if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
 773                 goto discard_and_relse;
 774 
 775         return __sk_receive_skb(sk, skb, 1, dh->dccph_doff * 4,
 776                                 refcounted) ? -1 : 0;
 777 
 778 no_dccp_socket:
 779         if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 780                 goto discard_it;
 781         /*
 782          * Step 2:
 783          *      If no socket ...
 784          *              Generate Reset(No Connection) unless P.type == Reset
 785          *              Drop packet and return
 786          */
 787         if (dh->dccph_type != DCCP_PKT_RESET) {
 788                 DCCP_SKB_CB(skb)->dccpd_reset_code =
 789                                         DCCP_RESET_CODE_NO_CONNECTION;
 790                 dccp_v6_ctl_send_reset(sk, skb);
 791         }
 792 
 793 discard_it:
 794         kfree_skb(skb);
 795         return 0;
 796 
 797 discard_and_relse:
 798         if (refcounted)
 799                 sock_put(sk);
 800         goto discard_it;
 801 }
 802 
 803 static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 804                            int addr_len)
 805 {
 806         struct sockaddr_in6 *usin = (struct sockaddr_in6 *)uaddr;
 807         struct inet_connection_sock *icsk = inet_csk(sk);
 808         struct inet_sock *inet = inet_sk(sk);
 809         struct ipv6_pinfo *np = inet6_sk(sk);
 810         struct dccp_sock *dp = dccp_sk(sk);
 811         struct in6_addr *saddr = NULL, *final_p, final;
 812         struct ipv6_txoptions *opt;
 813         struct flowi6 fl6;
 814         struct dst_entry *dst;
 815         int addr_type;
 816         int err;
 817 
 818         dp->dccps_role = DCCP_ROLE_CLIENT;
 819 
 820         if (addr_len < SIN6_LEN_RFC2133)
 821                 return -EINVAL;
 822 
 823         if (usin->sin6_family != AF_INET6)
 824                 return -EAFNOSUPPORT;
 825 
 826         memset(&fl6, 0, sizeof(fl6));
 827 
 828         if (np->sndflow) {
 829                 fl6.flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 830                 IP6_ECN_flow_init(fl6.flowlabel);
 831                 if (fl6.flowlabel & IPV6_FLOWLABEL_MASK) {
 832                         struct ip6_flowlabel *flowlabel;
 833                         flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 834                         if (IS_ERR(flowlabel))
 835                                 return -EINVAL;
 836                         fl6_sock_release(flowlabel);
 837                 }
 838         }
 839         /*
 840          * connect() to INADDR_ANY means loopback (BSD'ism).
 841          */
 842         if (ipv6_addr_any(&usin->sin6_addr))
 843                 usin->sin6_addr.s6_addr[15] = 1;
 844 
 845         addr_type = ipv6_addr_type(&usin->sin6_addr);
 846 
 847         if (addr_type & IPV6_ADDR_MULTICAST)
 848                 return -ENETUNREACH;
 849 
 850         if (addr_type & IPV6_ADDR_LINKLOCAL) {
 851                 if (addr_len >= sizeof(struct sockaddr_in6) &&
 852                     usin->sin6_scope_id) {
 853                         /* If interface is set while binding, indices
 854                          * must coincide.
 855                          */
 856                         if (sk->sk_bound_dev_if &&
 857                             sk->sk_bound_dev_if != usin->sin6_scope_id)
 858                                 return -EINVAL;
 859 
 860                         sk->sk_bound_dev_if = usin->sin6_scope_id;
 861                 }
 862 
 863                 /* Connect to link-local address requires an interface */
 864                 if (!sk->sk_bound_dev_if)
 865                         return -EINVAL;
 866         }
 867 
 868         sk->sk_v6_daddr = usin->sin6_addr;
 869         np->flow_label = fl6.flowlabel;
 870 
 871         /*
 872          * DCCP over IPv4
 873          */
 874         if (addr_type == IPV6_ADDR_MAPPED) {
 875                 u32 exthdrlen = icsk->icsk_ext_hdr_len;
 876                 struct sockaddr_in sin;
 877 
 878                 SOCK_DEBUG(sk, "connect: ipv4 mapped\n");
 879 
 880                 if (__ipv6_only_sock(sk))
 881                         return -ENETUNREACH;
 882 
 883                 sin.sin_family = AF_INET;
 884                 sin.sin_port = usin->sin6_port;
 885                 sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 886 
 887                 icsk->icsk_af_ops = &dccp_ipv6_mapped;
 888                 sk->sk_backlog_rcv = dccp_v4_do_rcv;
 889 
 890                 err = dccp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 891                 if (err) {
 892                         icsk->icsk_ext_hdr_len = exthdrlen;
 893                         icsk->icsk_af_ops = &dccp_ipv6_af_ops;
 894                         sk->sk_backlog_rcv = dccp_v6_do_rcv;
 895                         goto failure;
 896                 }
 897                 np->saddr = sk->sk_v6_rcv_saddr;
 898                 return err;
 899         }
 900 
 901         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 902                 saddr = &sk->sk_v6_rcv_saddr;
 903 
 904         fl6.flowi6_proto = IPPROTO_DCCP;
 905         fl6.daddr = sk->sk_v6_daddr;
 906         fl6.saddr = saddr ? *saddr : np->saddr;
 907         fl6.flowi6_oif = sk->sk_bound_dev_if;
 908         fl6.fl6_dport = usin->sin6_port;
 909         fl6.fl6_sport = inet->inet_sport;
 910         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 911 
 912         opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
 913         final_p = fl6_update_dst(&fl6, opt, &final);
 914 
 915         dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
 916         if (IS_ERR(dst)) {
 917                 err = PTR_ERR(dst);
 918                 goto failure;
 919         }
 920 
 921         if (saddr == NULL) {
 922                 saddr = &fl6.saddr;
 923                 sk->sk_v6_rcv_saddr = *saddr;
 924         }
 925 
 926         /* set the source address */
 927         np->saddr = *saddr;
 928         inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 929 
 930         ip6_dst_store(sk, dst, NULL, NULL);
 931 
 932         icsk->icsk_ext_hdr_len = 0;
 933         if (opt)
 934                 icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
 935 
 936         inet->inet_dport = usin->sin6_port;
 937 
 938         dccp_set_state(sk, DCCP_REQUESTING);
 939         err = inet6_hash_connect(&dccp_death_row, sk);
 940         if (err)
 941                 goto late_failure;
 942 
 943         dp->dccps_iss = secure_dccpv6_sequence_number(np->saddr.s6_addr32,
 944                                                       sk->sk_v6_daddr.s6_addr32,
 945                                                       inet->inet_sport,
 946                                                       inet->inet_dport);
 947         err = dccp_connect(sk);
 948         if (err)
 949                 goto late_failure;
 950 
 951         return 0;
 952 
 953 late_failure:
 954         dccp_set_state(sk, DCCP_CLOSED);
 955         __sk_dst_reset(sk);
 956 failure:
 957         inet->inet_dport = 0;
 958         sk->sk_route_caps = 0;
 959         return err;
 960 }
 961 
 962 static const struct inet_connection_sock_af_ops dccp_ipv6_af_ops = {
 963         .queue_xmit        = inet6_csk_xmit,
 964         .send_check        = dccp_v6_send_check,
 965         .rebuild_header    = inet6_sk_rebuild_header,
 966         .conn_request      = dccp_v6_conn_request,
 967         .syn_recv_sock     = dccp_v6_request_recv_sock,
 968         .net_header_len    = sizeof(struct ipv6hdr),
 969         .setsockopt        = ipv6_setsockopt,
 970         .getsockopt        = ipv6_getsockopt,
 971         .addr2sockaddr     = inet6_csk_addr2sockaddr,
 972         .sockaddr_len      = sizeof(struct sockaddr_in6),
 973 #ifdef CONFIG_COMPAT
 974         .compat_setsockopt = compat_ipv6_setsockopt,
 975         .compat_getsockopt = compat_ipv6_getsockopt,
 976 #endif
 977 };
 978 
 979 /*
 980  *      DCCP over IPv4 via INET6 API
 981  */
 982 static const struct inet_connection_sock_af_ops dccp_ipv6_mapped = {
 983         .queue_xmit        = ip_queue_xmit,
 984         .send_check        = dccp_v4_send_check,
 985         .rebuild_header    = inet_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 iphdr),
 989         .setsockopt        = ipv6_setsockopt,
 990         .getsockopt        = ipv6_getsockopt,
 991         .addr2sockaddr     = inet6_csk_addr2sockaddr,
 992         .sockaddr_len      = sizeof(struct sockaddr_in6),
 993 #ifdef CONFIG_COMPAT
 994         .compat_setsockopt = compat_ipv6_setsockopt,
 995         .compat_getsockopt = compat_ipv6_getsockopt,
 996 #endif
 997 };
 998 
 999 /* NOTE: A lot of things set to zero explicitly by call to
1000  *       sk_alloc() so need not be done here.
1001  */
1002 static int dccp_v6_init_sock(struct sock *sk)
1003 {
1004         static __u8 dccp_v6_ctl_sock_initialized;
1005         int err = dccp_init_sock(sk, dccp_v6_ctl_sock_initialized);
1006 
1007         if (err == 0) {
1008                 if (unlikely(!dccp_v6_ctl_sock_initialized))
1009                         dccp_v6_ctl_sock_initialized = 1;
1010                 inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
1011         }
1012 
1013         return err;
1014 }
1015 
1016 static void dccp_v6_destroy_sock(struct sock *sk)
1017 {
1018         dccp_destroy_sock(sk);
1019         inet6_destroy_sock(sk);
1020 }
1021 
1022 static struct timewait_sock_ops dccp6_timewait_sock_ops = {
1023         .twsk_obj_size  = sizeof(struct dccp6_timewait_sock),
1024 };
1025 
1026 static struct proto dccp_v6_prot = {
1027         .name              = "DCCPv6",
1028         .owner             = THIS_MODULE,
1029         .close             = dccp_close,
1030         .connect           = dccp_v6_connect,
1031         .disconnect        = dccp_disconnect,
1032         .ioctl             = dccp_ioctl,
1033         .init              = dccp_v6_init_sock,
1034         .setsockopt        = dccp_setsockopt,
1035         .getsockopt        = dccp_getsockopt,
1036         .sendmsg           = dccp_sendmsg,
1037         .recvmsg           = dccp_recvmsg,
1038         .backlog_rcv       = dccp_v6_do_rcv,
1039         .hash              = inet6_hash,
1040         .unhash            = inet_unhash,
1041         .accept            = inet_csk_accept,
1042         .get_port          = inet_csk_get_port,
1043         .shutdown          = dccp_shutdown,
1044         .destroy           = dccp_v6_destroy_sock,
1045         .orphan_count      = &dccp_orphan_count,
1046         .max_header        = MAX_DCCP_HEADER,
1047         .obj_size          = sizeof(struct dccp6_sock),
1048         .slab_flags        = SLAB_TYPESAFE_BY_RCU,
1049         .rsk_prot          = &dccp6_request_sock_ops,
1050         .twsk_prot         = &dccp6_timewait_sock_ops,
1051         .h.hashinfo        = &dccp_hashinfo,
1052 #ifdef CONFIG_COMPAT
1053         .compat_setsockopt = compat_dccp_setsockopt,
1054         .compat_getsockopt = compat_dccp_getsockopt,
1055 #endif
1056 };
1057 
1058 static const struct inet6_protocol dccp_v6_protocol = {
1059         .handler        = dccp_v6_rcv,
1060         .err_handler    = dccp_v6_err,
1061         .flags          = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1062 };
1063 
1064 static const struct proto_ops inet6_dccp_ops = {
1065         .family            = PF_INET6,
1066         .owner             = THIS_MODULE,
1067         .release           = inet6_release,
1068         .bind              = inet6_bind,
1069         .connect           = inet_stream_connect,
1070         .socketpair        = sock_no_socketpair,
1071         .accept            = inet_accept,
1072         .getname           = inet6_getname,
1073         .poll              = dccp_poll,
1074         .ioctl             = inet6_ioctl,
1075         .gettstamp         = sock_gettstamp,
1076         .listen            = inet_dccp_listen,
1077         .shutdown          = inet_shutdown,
1078         .setsockopt        = sock_common_setsockopt,
1079         .getsockopt        = sock_common_getsockopt,
1080         .sendmsg           = inet_sendmsg,
1081         .recvmsg           = sock_common_recvmsg,
1082         .mmap              = sock_no_mmap,
1083         .sendpage          = sock_no_sendpage,
1084 #ifdef CONFIG_COMPAT
1085         .compat_setsockopt = compat_sock_common_setsockopt,
1086         .compat_getsockopt = compat_sock_common_getsockopt,
1087 #endif
1088 };
1089 
1090 static struct inet_protosw dccp_v6_protosw = {
1091         .type           = SOCK_DCCP,
1092         .protocol       = IPPROTO_DCCP,
1093         .prot           = &dccp_v6_prot,
1094         .ops            = &inet6_dccp_ops,
1095         .flags          = INET_PROTOSW_ICSK,
1096 };
1097 
1098 static int __net_init dccp_v6_init_net(struct net *net)
1099 {
1100         if (dccp_hashinfo.bhash == NULL)
1101                 return -ESOCKTNOSUPPORT;
1102 
1103         return inet_ctl_sock_create(&net->dccp.v6_ctl_sk, PF_INET6,
1104                                     SOCK_DCCP, IPPROTO_DCCP, net);
1105 }
1106 
1107 static void __net_exit dccp_v6_exit_net(struct net *net)
1108 {
1109         inet_ctl_sock_destroy(net->dccp.v6_ctl_sk);
1110 }
1111 
1112 static void __net_exit dccp_v6_exit_batch(struct list_head *net_exit_list)
1113 {
1114         inet_twsk_purge(&dccp_hashinfo, AF_INET6);
1115 }
1116 
1117 static struct pernet_operations dccp_v6_ops = {
1118         .init   = dccp_v6_init_net,
1119         .exit   = dccp_v6_exit_net,
1120         .exit_batch = dccp_v6_exit_batch,
1121 };
1122 
1123 static int __init dccp_v6_init(void)
1124 {
1125         int err = proto_register(&dccp_v6_prot, 1);
1126 
1127         if (err)
1128                 goto out;
1129 
1130         inet6_register_protosw(&dccp_v6_protosw);
1131 
1132         err = register_pernet_subsys(&dccp_v6_ops);
1133         if (err)
1134                 goto out_destroy_ctl_sock;
1135 
1136         err = inet6_add_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1137         if (err)
1138                 goto out_unregister_proto;
1139 
1140 out:
1141         return err;
1142 out_unregister_proto:
1143         unregister_pernet_subsys(&dccp_v6_ops);
1144 out_destroy_ctl_sock:
1145         inet6_unregister_protosw(&dccp_v6_protosw);
1146         proto_unregister(&dccp_v6_prot);
1147         goto out;
1148 }
1149 
1150 static void __exit dccp_v6_exit(void)
1151 {
1152         inet6_del_protocol(&dccp_v6_protocol, IPPROTO_DCCP);
1153         unregister_pernet_subsys(&dccp_v6_ops);
1154         inet6_unregister_protosw(&dccp_v6_protosw);
1155         proto_unregister(&dccp_v6_prot);
1156 }
1157 
1158 module_init(dccp_v6_init);
1159 module_exit(dccp_v6_exit);
1160 
1161 /*
1162  * __stringify doesn't likes enums, so use SOCK_DCCP (6) and IPPROTO_DCCP (33)
1163  * values directly, Also cover the case where the protocol is not specified,
1164  * i.e. net-pf-PF_INET6-proto-0-type-SOCK_DCCP
1165  */
1166 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 33, 6);
1167 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 0, 6);
1168 MODULE_LICENSE("GPL");
1169 MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
1170 MODULE_DESCRIPTION("DCCPv6 - Datagram Congestion Controlled Protocol");
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root/net/dccp/ipv6.c

DEFINITIONS
