net/netfilter/nfnetlink_cttimeout.c

   1 /*
   2  * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>
   3  * (C) 2012 by Vyatta Inc. <http://www.vyatta.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation (or any later at your option).
   8  */
   9 #include <linux/init.h>
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/rculist.h>
  13 #include <linux/rculist_nulls.h>
  14 #include <linux/types.h>
  15 #include <linux/timer.h>
  16 #include <linux/security.h>
  17 #include <linux/skbuff.h>
  18 #include <linux/errno.h>
  19 #include <linux/netlink.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/slab.h>
  23
  24 #include <linux/netfilter.h>
  25 #include <net/netlink.h>
  26 #include <net/sock.h>
  27 #include <net/netfilter/nf_conntrack.h>
  28 #include <net/netfilter/nf_conntrack_core.h>
  29 #include <net/netfilter/nf_conntrack_l4proto.h>
  30 #include <net/netfilter/nf_conntrack_tuple.h>
  31 #include <net/netfilter/nf_conntrack_timeout.h>
  32
  33 #include <linux/netfilter/nfnetlink.h>
  34 #include <linux/netfilter/nfnetlink_cttimeout.h>
  35
  36 MODULE_LICENSE("GPL");
  37 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
  38 MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
  39
  40 static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
  41         [CTA_TIMEOUT_NAME]      = { .type = NLA_NUL_STRING,
  42                                     .len  = CTNL_TIMEOUT_NAME_MAX - 1},
  43         [CTA_TIMEOUT_L3PROTO]   = { .type = NLA_U16 },
  44         [CTA_TIMEOUT_L4PROTO]   = { .type = NLA_U8 },
  45         [CTA_TIMEOUT_DATA]      = { .type = NLA_NESTED },
  46 };
  47
  48 static int
  49 ctnl_timeout_parse_policy(void *timeout,
  50                           const struct nf_conntrack_l4proto *l4proto,
  51                           struct net *net, const struct nlattr *attr)
  52 {
  53         struct nlattr **tb;
  54         int ret = 0;
  55
  56         if (!l4proto->ctnl_timeout.nlattr_to_obj)
  57                 return 0;
  58
  59         tb = kcalloc(l4proto->ctnl_timeout.nlattr_max + 1, sizeof(*tb),
  60                      GFP_KERNEL);
  61
  62         if (!tb)
  63                 return -ENOMEM;
  64
  65         ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max, attr,
  66                                l4proto->ctnl_timeout.nla_policy, NULL);
  67         if (ret < 0)
  68                 goto err;
  69
  70         ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeout);
  71
  72 err:
  73         kfree(tb);
  74         return ret;
  75 }
  76
  77 static int cttimeout_new_timeout(struct net *net, struct sock *ctnl,
  78                                  struct sk_buff *skb,
  79                                  const struct nlmsghdr *nlh,
  80                                  const struct nlattr * const cda[],
  81                                  struct netlink_ext_ack *extack)
  82 {
  83         __u16 l3num;
  84         __u8 l4num;
  85         const struct nf_conntrack_l4proto *l4proto;
  86         struct ctnl_timeout *timeout, *matching = NULL;
  87         char *name;
  88         int ret;
  89
  90         if (!cda[CTA_TIMEOUT_NAME] ||
  91             !cda[CTA_TIMEOUT_L3PROTO] ||
  92             !cda[CTA_TIMEOUT_L4PROTO] ||
  93             !cda[CTA_TIMEOUT_DATA])
  94                 return -EINVAL;
  95
  96         name = nla_data(cda[CTA_TIMEOUT_NAME]);
  97         l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
  98         l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
  99
 100         list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
 101                 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
 102                         continue;
 103
 104                 if (nlh->nlmsg_flags & NLM_F_EXCL)
 105                         return -EEXIST;
 106
 107                 matching = timeout;
 108                 break;
 109         }
 110
 111         if (matching) {
 112                 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
 113                         /* You cannot replace one timeout policy by another of
 114                          * different kind, sorry.
 115                          */
 116                         if (matching->timeout.l3num != l3num ||
 117                             matching->timeout.l4proto->l4proto != l4num)
 118                                 return -EINVAL;
 119
 120                         return ctnl_timeout_parse_policy(&matching->timeout.data,
 121                                                          matching->timeout.l4proto,
 122                                                          net, cda[CTA_TIMEOUT_DATA]);
 123                 }
 124
 125                 return -EBUSY;
 126         }
 127
 128         l4proto = nf_ct_l4proto_find_get(l3num, l4num);
 129
 130         /* This protocol is not supportted, skip. */
 131         if (l4proto->l4proto != l4num) {
 132                 ret = -EOPNOTSUPP;
 133                 goto err_proto_put;
 134         }
 135
 136         timeout = kzalloc(sizeof(struct ctnl_timeout) +
 137                           l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
 138         if (timeout == NULL) {
 139                 ret = -ENOMEM;
 140                 goto err_proto_put;
 141         }
 142
 143         ret = ctnl_timeout_parse_policy(&timeout->timeout.data, l4proto, net,
 144                                         cda[CTA_TIMEOUT_DATA]);
 145         if (ret < 0)
 146                 goto err;
 147
 148         strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
 149         timeout->timeout.l3num = l3num;
 150         timeout->timeout.l4proto = l4proto;
 151         refcount_set(&timeout->refcnt, 1);
 152         list_add_tail_rcu(&timeout->head, &net->nfct_timeout_list);
 153
 154         return 0;
 155 err:
 156         kfree(timeout);
 157 err_proto_put:
 158         nf_ct_l4proto_put(l4proto);
 159         return ret;
 160 }
 161
 162 static int
 163 ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
 164                        int event, struct ctnl_timeout *timeout)
 165 {
 166         struct nlmsghdr *nlh;
 167         struct nfgenmsg *nfmsg;
 168         unsigned int flags = portid ? NLM_F_MULTI : 0;
 169         const struct nf_conntrack_l4proto *l4proto = timeout->timeout.l4proto;
 170
 171         event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
 172         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
 173         if (nlh == NULL)
 174                 goto nlmsg_failure;
 175
 176         nfmsg = nlmsg_data(nlh);
 177         nfmsg->nfgen_family = AF_UNSPEC;
 178         nfmsg->version = NFNETLINK_V0;
 179         nfmsg->res_id = 0;
 180
 181         if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
 182             nla_put_be16(skb, CTA_TIMEOUT_L3PROTO,
 183                          htons(timeout->timeout.l3num)) ||
 184             nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto) ||
 185             nla_put_be32(skb, CTA_TIMEOUT_USE,
 186                          htonl(refcount_read(&timeout->refcnt))))
 187                 goto nla_put_failure;
 188
 189         if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
 190                 struct nlattr *nest_parms;
 191                 int ret;
 192
 193                 nest_parms = nla_nest_start(skb,
 194                                             CTA_TIMEOUT_DATA | NLA_F_NESTED);
 195                 if (!nest_parms)
 196                         goto nla_put_failure;
 197
 198                 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb,
 199                                                         &timeout->timeout.data);
 200                 if (ret < 0)
 201                         goto nla_put_failure;
 202
 203                 nla_nest_end(skb, nest_parms);
 204         }
 205
 206         nlmsg_end(skb, nlh);
 207         return skb->len;
 208
 209 nlmsg_failure:
 210 nla_put_failure:
 211         nlmsg_cancel(skb, nlh);
 212         return -1;
 213 }
 214
 215 static int
 216 ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
 217 {
 218         struct net *net = sock_net(skb->sk);
 219         struct ctnl_timeout *cur, *last;
 220
 221         if (cb->args[2])
 222                 return 0;
 223
 224         last = (struct ctnl_timeout *)cb->args[1];
 225         if (cb->args[1])
 226                 cb->args[1] = 0;
 227
 228         rcu_read_lock();
 229         list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
 230                 if (last) {
 231                         if (cur != last)
 232                                 continue;
 233
 234                         last = NULL;
 235                 }
 236                 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
 237                                            cb->nlh->nlmsg_seq,
 238                                            NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
 239                                            IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
 240                         cb->args[1] = (unsigned long)cur;
 241                         break;
 242                 }
 243         }
 244         if (!cb->args[1])
 245                 cb->args[2] = 1;
 246         rcu_read_unlock();
 247         return skb->len;
 248 }
 249
 250 static int cttimeout_get_timeout(struct net *net, struct sock *ctnl,
 251                                  struct sk_buff *skb,
 252                                  const struct nlmsghdr *nlh,
 253                                  const struct nlattr * const cda[],
 254                                  struct netlink_ext_ack *extack)
 255 {
 256         int ret = -ENOENT;
 257         char *name;
 258         struct ctnl_timeout *cur;
 259
 260         if (nlh->nlmsg_flags & NLM_F_DUMP) {
 261                 struct netlink_dump_control c = {
 262                         .dump = ctnl_timeout_dump,
 263                 };
 264                 return netlink_dump_start(ctnl, skb, nlh, &c);
 265         }
 266
 267         if (!cda[CTA_TIMEOUT_NAME])
 268                 return -EINVAL;
 269         name = nla_data(cda[CTA_TIMEOUT_NAME]);
 270
 271         list_for_each_entry(cur, &net->nfct_timeout_list, head) {
 272                 struct sk_buff *skb2;
 273
 274                 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
 275                         continue;
 276
 277                 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 278                 if (skb2 == NULL) {
 279                         ret = -ENOMEM;
 280                         break;
 281                 }
 282
 283                 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
 284                                              nlh->nlmsg_seq,
 285                                              NFNL_MSG_TYPE(nlh->nlmsg_type),
 286                                              IPCTNL_MSG_TIMEOUT_NEW, cur);
 287                 if (ret <= 0) {
 288                         kfree_skb(skb2);
 289                         break;
 290                 }
 291                 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
 292                                         MSG_DONTWAIT);
 293                 if (ret > 0)
 294                         ret = 0;
 295
 296                 /* this avoids a loop in nfnetlink. */
 297                 return ret == -EAGAIN ? -ENOBUFS : ret;
 298         }
 299         return ret;
 300 }
 301
 302 /* try to delete object, fail if it is still in use. */
 303 static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
 304 {
 305         int ret = 0;
 306
 307         /* We want to avoid races with ctnl_timeout_put. So only when the
 308          * current refcnt is 1, we decrease it to 0.
 309          */
 310         if (refcount_dec_if_one(&timeout->refcnt)) {
 311                 /* We are protected by nfnl mutex. */
 312                 list_del_rcu(&timeout->head);
 313                 nf_ct_l4proto_put(timeout->timeout.l4proto);
 314                 nf_ct_untimeout(net, &timeout->timeout);
 315                 kfree_rcu(timeout, rcu_head);
 316         } else {
 317                 ret = -EBUSY;
 318         }
 319         return ret;
 320 }
 321
 322 static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
 323                                  struct sk_buff *skb,
 324                                  const struct nlmsghdr *nlh,
 325                                  const struct nlattr * const cda[],
 326                                  struct netlink_ext_ack *extack)
 327 {
 328         struct ctnl_timeout *cur, *tmp;
 329         int ret = -ENOENT;
 330         char *name;
 331
 332         if (!cda[CTA_TIMEOUT_NAME]) {
 333                 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list,
 334                                          head)
 335                         ctnl_timeout_try_del(net, cur);
 336
 337                 return 0;
 338         }
 339         name = nla_data(cda[CTA_TIMEOUT_NAME]);
 340
 341         list_for_each_entry(cur, &net->nfct_timeout_list, head) {
 342                 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
 343                         continue;
 344
 345                 ret = ctnl_timeout_try_del(net, cur);
 346                 if (ret < 0)
 347                         return ret;
 348
 349                 break;
 350         }
 351         return ret;
 352 }
 353
 354 static int cttimeout_default_set(struct net *net, struct sock *ctnl,
 355                                  struct sk_buff *skb,
 356                                  const struct nlmsghdr *nlh,
 357                                  const struct nlattr * const cda[],
 358                                  struct netlink_ext_ack *extack)
 359 {
 360         const struct nf_conntrack_l4proto *l4proto;
 361         __u16 l3num;
 362         __u8 l4num;
 363         int ret;
 364
 365         if (!cda[CTA_TIMEOUT_L3PROTO] ||
 366             !cda[CTA_TIMEOUT_L4PROTO] ||
 367             !cda[CTA_TIMEOUT_DATA])
 368                 return -EINVAL;
 369
 370         l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
 371         l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
 372         l4proto = nf_ct_l4proto_find_get(l3num, l4num);
 373
 374         /* This protocol is not supported, skip. */
 375         if (l4proto->l4proto != l4num) {
 376                 ret = -EOPNOTSUPP;
 377                 goto err;
 378         }
 379
 380         ret = ctnl_timeout_parse_policy(NULL, l4proto, net,
 381                                         cda[CTA_TIMEOUT_DATA]);
 382         if (ret < 0)
 383                 goto err;
 384
 385         nf_ct_l4proto_put(l4proto);
 386         return 0;
 387 err:
 388         nf_ct_l4proto_put(l4proto);
 389         return ret;
 390 }
 391
 392 static int
 393 cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
 394                             u32 seq, u32 type, int event,
 395                             const struct nf_conntrack_l4proto *l4proto,
 396                             const unsigned int *timeouts)
 397 {
 398         struct nlmsghdr *nlh;
 399         struct nfgenmsg *nfmsg;
 400         unsigned int flags = portid ? NLM_F_MULTI : 0;
 401
 402         event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
 403         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
 404         if (nlh == NULL)
 405                 goto nlmsg_failure;
 406
 407         nfmsg = nlmsg_data(nlh);
 408         nfmsg->nfgen_family = AF_UNSPEC;
 409         nfmsg->version = NFNETLINK_V0;
 410         nfmsg->res_id = 0;
 411
 412         if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l4proto->l3proto)) ||
 413             nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
 414                 goto nla_put_failure;
 415
 416         if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
 417                 struct nlattr *nest_parms;
 418                 int ret;
 419
 420                 nest_parms = nla_nest_start(skb,
 421                                             CTA_TIMEOUT_DATA | NLA_F_NESTED);
 422                 if (!nest_parms)
 423                         goto nla_put_failure;
 424
 425                 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
 426                 if (ret < 0)
 427                         goto nla_put_failure;
 428
 429                 nla_nest_end(skb, nest_parms);
 430         }
 431
 432         nlmsg_end(skb, nlh);
 433         return skb->len;
 434
 435 nlmsg_failure:
 436 nla_put_failure:
 437         nlmsg_cancel(skb, nlh);
 438         return -1;
 439 }
 440
 441 static int cttimeout_default_get(struct net *net, struct sock *ctnl,
 442                                  struct sk_buff *skb,
 443                                  const struct nlmsghdr *nlh,
 444                                  const struct nlattr * const cda[],
 445                                  struct netlink_ext_ack *extack)
 446 {
 447         const struct nf_conntrack_l4proto *l4proto;
 448         unsigned int *timeouts = NULL;
 449         struct sk_buff *skb2;
 450         int ret, err;
 451         __u16 l3num;
 452         __u8 l4num;
 453
 454         if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
 455                 return -EINVAL;
 456
 457         l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
 458         l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
 459         l4proto = nf_ct_l4proto_find_get(l3num, l4num);
 460
 461         err = -EOPNOTSUPP;
 462         if (l4proto->l4proto != l4num)
 463                 goto err;
 464
 465         switch (l4proto->l4proto) {
 466         case IPPROTO_ICMP:
 467                 timeouts = &net->ct.nf_ct_proto.icmp.timeout;
 468                 break;
 469         case IPPROTO_TCP:
 470                 timeouts = net->ct.nf_ct_proto.tcp.timeouts;
 471                 break;
 472         case IPPROTO_UDP: /* fallthrough */
 473         case IPPROTO_UDPLITE:
 474                 timeouts = net->ct.nf_ct_proto.udp.timeouts;
 475                 break;
 476         case IPPROTO_DCCP:
 477 #ifdef CONFIG_NF_CT_PROTO_DCCP
 478                 timeouts = net->ct.nf_ct_proto.dccp.dccp_timeout;
 479 #endif
 480                 break;
 481         case IPPROTO_ICMPV6:
 482                 timeouts = &net->ct.nf_ct_proto.icmpv6.timeout;
 483                 break;
 484         case IPPROTO_SCTP:
 485 #ifdef CONFIG_NF_CT_PROTO_SCTP
 486                 timeouts = net->ct.nf_ct_proto.sctp.timeouts;
 487 #endif
 488                 break;
 489         case IPPROTO_GRE:
 490 #ifdef CONFIG_NF_CT_PROTO_GRE
 491                 if (l4proto->net_id) {
 492                         struct netns_proto_gre *net_gre;
 493
 494                         net_gre = net_generic(net, *l4proto->net_id);
 495                         timeouts = net_gre->gre_timeouts;
 496                 }
 497 #endif
 498                 break;
 499         case 255:
 500                 timeouts = &net->ct.nf_ct_proto.generic.timeout;
 501                 break;
 502         default:
 503                 WARN_ONCE(1, "Missing timeouts for proto %d", l4proto->l4proto);
 504                 break;
 505         }
 506
 507         if (!timeouts)
 508                 goto err;
 509
 510         skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 511         if (skb2 == NULL) {
 512                 err = -ENOMEM;
 513                 goto err;
 514         }
 515
 516         ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
 517                                           nlh->nlmsg_seq,
 518                                           NFNL_MSG_TYPE(nlh->nlmsg_type),
 519                                           IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
 520                                           l4proto, timeouts);
 521         if (ret <= 0) {
 522                 kfree_skb(skb2);
 523                 err = -ENOMEM;
 524                 goto err;
 525         }
 526         ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
 527         if (ret > 0)
 528                 ret = 0;
 529
 530         /* this avoids a loop in nfnetlink. */
 531         return ret == -EAGAIN ? -ENOBUFS : ret;
 532 err:
 533         nf_ct_l4proto_put(l4proto);
 534         return err;
 535 }
 536
 537 static struct nf_ct_timeout *ctnl_timeout_find_get(struct net *net,
 538                                                    const char *name)
 539 {
 540         struct ctnl_timeout *timeout, *matching = NULL;
 541
 542         list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
 543                 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
 544                         continue;
 545
 546                 if (!try_module_get(THIS_MODULE))
 547                         goto err;
 548
 549                 if (!refcount_inc_not_zero(&timeout->refcnt)) {
 550                         module_put(THIS_MODULE);
 551                         goto err;
 552                 }
 553                 matching = timeout;
 554                 break;
 555         }
 556 err:
 557         return matching ? &matching->timeout : NULL;
 558 }
 559
 560 static void ctnl_timeout_put(struct nf_ct_timeout *t)
 561 {
 562         struct ctnl_timeout *timeout =
 563                 container_of(t, struct ctnl_timeout, timeout);
 564
 565         if (refcount_dec_and_test(&timeout->refcnt))
 566                 kfree_rcu(timeout, rcu_head);
 567
 568         module_put(THIS_MODULE);
 569 }
 570
 571 static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
 572         [IPCTNL_MSG_TIMEOUT_NEW]        = { .call = cttimeout_new_timeout,
 573                                             .attr_count = CTA_TIMEOUT_MAX,
 574                                             .policy = cttimeout_nla_policy },
 575         [IPCTNL_MSG_TIMEOUT_GET]        = { .call = cttimeout_get_timeout,
 576                                             .attr_count = CTA_TIMEOUT_MAX,
 577                                             .policy = cttimeout_nla_policy },
 578         [IPCTNL_MSG_TIMEOUT_DELETE]     = { .call = cttimeout_del_timeout,
 579                                             .attr_count = CTA_TIMEOUT_MAX,
 580                                             .policy = cttimeout_nla_policy },
 581         [IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
 582                                             .attr_count = CTA_TIMEOUT_MAX,
 583                                             .policy = cttimeout_nla_policy },
 584         [IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
 585                                             .attr_count = CTA_TIMEOUT_MAX,
 586                                             .policy = cttimeout_nla_policy },
 587 };
 588
 589 static const struct nfnetlink_subsystem cttimeout_subsys = {
 590         .name                           = "conntrack_timeout",
 591         .subsys_id                      = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
 592         .cb_count                       = IPCTNL_MSG_TIMEOUT_MAX,
 593         .cb                             = cttimeout_cb,
 594 };
 595
 596 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
 597
 598 static int __net_init cttimeout_net_init(struct net *net)
 599 {
 600         INIT_LIST_HEAD(&net->nfct_timeout_list);
 601
 602         return 0;
 603 }
 604
 605 static void __net_exit cttimeout_net_exit(struct net *net)
 606 {
 607         struct ctnl_timeout *cur, *tmp;
 608
 609         nf_ct_unconfirmed_destroy(net);
 610         nf_ct_untimeout(net, NULL);
 611
 612         list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
 613                 list_del_rcu(&cur->head);
 614                 nf_ct_l4proto_put(cur->timeout.l4proto);
 615
 616                 if (refcount_dec_and_test(&cur->refcnt))
 617                         kfree_rcu(cur, rcu_head);
 618         }
 619 }
 620
 621 static struct pernet_operations cttimeout_ops = {
 622         .init   = cttimeout_net_init,
 623         .exit   = cttimeout_net_exit,
 624 };
 625
 626 static int __init cttimeout_init(void)
 627 {
 628         int ret;
 629
 630         ret = register_pernet_subsys(&cttimeout_ops);
 631         if (ret < 0)
 632                 return ret;
 633
 634         ret = nfnetlink_subsys_register(&cttimeout_subsys);
 635         if (ret < 0) {
 636                 pr_err("cttimeout_init: cannot register cttimeout with "
 637                         "nfnetlink.\n");
 638                 goto err_out;
 639         }
 640         RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
 641         RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
 642         return 0;
 643
 644 err_out:
 645         unregister_pernet_subsys(&cttimeout_ops);
 646         return ret;
 647 }
 648
 649 static void __exit cttimeout_exit(void)
 650 {
 651         nfnetlink_subsys_unregister(&cttimeout_subsys);
 652
 653         unregister_pernet_subsys(&cttimeout_ops);
 654         RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
 655         RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
 656         synchronize_rcu();
 657 }
 658
 659 module_init(cttimeout_init);
 660 module_exit(cttimeout_exit);