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_l3proto.h>
  30 #include <net/netfilter/nf_conntrack_l4proto.h>
  31 #include <net/netfilter/nf_conntrack_tuple.h>
  32 #include <net/netfilter/nf_conntrack_timeout.h>
  33
  34 #include <linux/netfilter/nfnetlink.h>
  35 #include <linux/netfilter/nfnetlink_cttimeout.h>
  36
  37 MODULE_LICENSE("GPL");
  38 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
  39 MODULE_DESCRIPTION("cttimeout: Extended Netfilter Connection Tracking timeout tuning");
  40
  41 static const struct nla_policy cttimeout_nla_policy[CTA_TIMEOUT_MAX+1] = {
  42         [CTA_TIMEOUT_NAME]      = { .type = NLA_NUL_STRING,
  43                                     .len  = CTNL_TIMEOUT_NAME_MAX - 1},
  44         [CTA_TIMEOUT_L3PROTO]   = { .type = NLA_U16 },
  45         [CTA_TIMEOUT_L4PROTO]   = { .type = NLA_U8 },
  46         [CTA_TIMEOUT_DATA]      = { .type = NLA_NESTED },
  47 };
  48
  49 static int
  50 ctnl_timeout_parse_policy(void *timeouts, struct nf_conntrack_l4proto *l4proto,
  51                           struct net *net, const struct nlattr *attr)
  52 {
  53         int ret = 0;
  54
  55         if (likely(l4proto->ctnl_timeout.nlattr_to_obj)) {
  56                 struct nlattr *tb[l4proto->ctnl_timeout.nlattr_max+1];
  57
  58                 ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max,
  59                                        attr, l4proto->ctnl_timeout.nla_policy);
  60                 if (ret < 0)
  61                         return ret;
  62
  63                 ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeouts);
  64         }
  65         return ret;
  66 }
  67
  68 static int cttimeout_new_timeout(struct net *net, struct sock *ctnl,
  69                                  struct sk_buff *skb,
  70                                  const struct nlmsghdr *nlh,
  71                                  const struct nlattr * const cda[])
  72 {
  73         __u16 l3num;
  74         __u8 l4num;
  75         struct nf_conntrack_l4proto *l4proto;
  76         struct ctnl_timeout *timeout, *matching = NULL;
  77         char *name;
  78         int ret;
  79
  80         if (!cda[CTA_TIMEOUT_NAME] ||
  81             !cda[CTA_TIMEOUT_L3PROTO] ||
  82             !cda[CTA_TIMEOUT_L4PROTO] ||
  83             !cda[CTA_TIMEOUT_DATA])
  84                 return -EINVAL;
  85
  86         name = nla_data(cda[CTA_TIMEOUT_NAME]);
  87         l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
  88         l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
  89
  90         list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
  91                 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
  92                         continue;
  93
  94                 if (nlh->nlmsg_flags & NLM_F_EXCL)
  95                         return -EEXIST;
  96
  97                 matching = timeout;
  98                 break;
  99         }
 100
 101         l4proto = nf_ct_l4proto_find_get(l3num, l4num);
 102
 103         /* This protocol is not supportted, skip. */
 104         if (l4proto->l4proto != l4num) {
 105                 ret = -EOPNOTSUPP;
 106                 goto err_proto_put;
 107         }
 108
 109         if (matching) {
 110                 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
 111                         /* You cannot replace one timeout policy by another of
 112                          * different kind, sorry.
 113                          */
 114                         if (matching->l3num != l3num ||
 115                             matching->l4proto->l4proto != l4num) {
 116                                 ret = -EINVAL;
 117                                 goto err_proto_put;
 118                         }
 119
 120                         ret = ctnl_timeout_parse_policy(&matching->data,
 121                                                         l4proto, net,
 122                                                         cda[CTA_TIMEOUT_DATA]);
 123                         return ret;
 124                 }
 125                 ret = -EBUSY;
 126                 goto err_proto_put;
 127         }
 128
 129         timeout = kzalloc(sizeof(struct ctnl_timeout) +
 130                           l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
 131         if (timeout == NULL) {
 132                 ret = -ENOMEM;
 133                 goto err_proto_put;
 134         }
 135
 136         ret = ctnl_timeout_parse_policy(&timeout->data, l4proto, net,
 137                                         cda[CTA_TIMEOUT_DATA]);
 138         if (ret < 0)
 139                 goto err;
 140
 141         strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
 142         timeout->l3num = l3num;
 143         timeout->l4proto = l4proto;
 144         atomic_set(&timeout->refcnt, 1);
 145         list_add_tail_rcu(&timeout->head, &net->nfct_timeout_list);
 146
 147         return 0;
 148 err:
 149         kfree(timeout);
 150 err_proto_put:
 151         nf_ct_l4proto_put(l4proto);
 152         return ret;
 153 }
 154
 155 static int
 156 ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
 157                        int event, struct ctnl_timeout *timeout)
 158 {
 159         struct nlmsghdr *nlh;
 160         struct nfgenmsg *nfmsg;
 161         unsigned int flags = portid ? NLM_F_MULTI : 0;
 162         struct nf_conntrack_l4proto *l4proto = timeout->l4proto;
 163
 164         event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
 165         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
 166         if (nlh == NULL)
 167                 goto nlmsg_failure;
 168
 169         nfmsg = nlmsg_data(nlh);
 170         nfmsg->nfgen_family = AF_UNSPEC;
 171         nfmsg->version = NFNETLINK_V0;
 172         nfmsg->res_id = 0;
 173
 174         if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
 175             nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(timeout->l3num)) ||
 176             nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, timeout->l4proto->l4proto) ||
 177             nla_put_be32(skb, CTA_TIMEOUT_USE,
 178                          htonl(atomic_read(&timeout->refcnt))))
 179                 goto nla_put_failure;
 180
 181         if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
 182                 struct nlattr *nest_parms;
 183                 int ret;
 184
 185                 nest_parms = nla_nest_start(skb,
 186                                             CTA_TIMEOUT_DATA | NLA_F_NESTED);
 187                 if (!nest_parms)
 188                         goto nla_put_failure;
 189
 190                 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->data);
 191                 if (ret < 0)
 192                         goto nla_put_failure;
 193
 194                 nla_nest_end(skb, nest_parms);
 195         }
 196
 197         nlmsg_end(skb, nlh);
 198         return skb->len;
 199
 200 nlmsg_failure:
 201 nla_put_failure:
 202         nlmsg_cancel(skb, nlh);
 203         return -1;
 204 }
 205
 206 static int
 207 ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
 208 {
 209         struct net *net = sock_net(skb->sk);
 210         struct ctnl_timeout *cur, *last;
 211
 212         if (cb->args[2])
 213                 return 0;
 214
 215         last = (struct ctnl_timeout *)cb->args[1];
 216         if (cb->args[1])
 217                 cb->args[1] = 0;
 218
 219         rcu_read_lock();
 220         list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
 221                 if (last) {
 222                         if (cur != last)
 223                                 continue;
 224
 225                         last = NULL;
 226                 }
 227                 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
 228                                            cb->nlh->nlmsg_seq,
 229                                            NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
 230                                            IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
 231                         cb->args[1] = (unsigned long)cur;
 232                         break;
 233                 }
 234         }
 235         if (!cb->args[1])
 236                 cb->args[2] = 1;
 237         rcu_read_unlock();
 238         return skb->len;
 239 }
 240
 241 static int cttimeout_get_timeout(struct net *net, struct sock *ctnl,
 242                                  struct sk_buff *skb,
 243                                  const struct nlmsghdr *nlh,
 244                                  const struct nlattr * const cda[])
 245 {
 246         int ret = -ENOENT;
 247         char *name;
 248         struct ctnl_timeout *cur;
 249
 250         if (nlh->nlmsg_flags & NLM_F_DUMP) {
 251                 struct netlink_dump_control c = {
 252                         .dump = ctnl_timeout_dump,
 253                 };
 254                 return netlink_dump_start(ctnl, skb, nlh, &c);
 255         }
 256
 257         if (!cda[CTA_TIMEOUT_NAME])
 258                 return -EINVAL;
 259         name = nla_data(cda[CTA_TIMEOUT_NAME]);
 260
 261         list_for_each_entry(cur, &net->nfct_timeout_list, head) {
 262                 struct sk_buff *skb2;
 263
 264                 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
 265                         continue;
 266
 267                 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 268                 if (skb2 == NULL) {
 269                         ret = -ENOMEM;
 270                         break;
 271                 }
 272
 273                 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
 274                                              nlh->nlmsg_seq,
 275                                              NFNL_MSG_TYPE(nlh->nlmsg_type),
 276                                              IPCTNL_MSG_TIMEOUT_NEW, cur);
 277                 if (ret <= 0) {
 278                         kfree_skb(skb2);
 279                         break;
 280                 }
 281                 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
 282                                         MSG_DONTWAIT);
 283                 if (ret > 0)
 284                         ret = 0;
 285
 286                 /* this avoids a loop in nfnetlink. */
 287                 return ret == -EAGAIN ? -ENOBUFS : ret;
 288         }
 289         return ret;
 290 }
 291
 292 static void untimeout(struct nf_conntrack_tuple_hash *i,
 293                       struct ctnl_timeout *timeout)
 294 {
 295         struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(i);
 296         struct nf_conn_timeout *timeout_ext = nf_ct_timeout_find(ct);
 297
 298         if (timeout_ext && (!timeout || timeout_ext->timeout == timeout))
 299                 RCU_INIT_POINTER(timeout_ext->timeout, NULL);
 300 }
 301
 302 static void ctnl_untimeout(struct net *net, struct ctnl_timeout *timeout)
 303 {
 304         struct nf_conntrack_tuple_hash *h;
 305         const struct hlist_nulls_node *nn;
 306         unsigned int last_hsize;
 307         spinlock_t *lock;
 308         int i;
 309
 310         local_bh_disable();
 311 restart:
 312         last_hsize = nf_conntrack_htable_size;
 313         for (i = 0; i < last_hsize; i++) {
 314                 lock = &nf_conntrack_locks[i % CONNTRACK_LOCKS];
 315                 nf_conntrack_lock(lock);
 316                 if (last_hsize != nf_conntrack_htable_size) {
 317                         spin_unlock(lock);
 318                         goto restart;
 319                 }
 320
 321                 hlist_nulls_for_each_entry(h, nn, &nf_conntrack_hash[i], hnnode)
 322                         untimeout(h, timeout);
 323                 spin_unlock(lock);
 324         }
 325         local_bh_enable();
 326 }
 327
 328 /* try to delete object, fail if it is still in use. */
 329 static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
 330 {
 331         int ret = 0;
 332
 333         /* We want to avoid races with ctnl_timeout_put. So only when the
 334          * current refcnt is 1, we decrease it to 0.
 335          */
 336         if (atomic_cmpxchg(&timeout->refcnt, 1, 0) == 1) {
 337                 /* We are protected by nfnl mutex. */
 338                 list_del_rcu(&timeout->head);
 339                 nf_ct_l4proto_put(timeout->l4proto);
 340                 ctnl_untimeout(net, timeout);
 341                 kfree_rcu(timeout, rcu_head);
 342         } else {
 343                 ret = -EBUSY;
 344         }
 345         return ret;
 346 }
 347
 348 static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
 349                                  struct sk_buff *skb,
 350                                  const struct nlmsghdr *nlh,
 351                                  const struct nlattr * const cda[])
 352 {
 353         struct ctnl_timeout *cur, *tmp;
 354         int ret = -ENOENT;
 355         char *name;
 356
 357         if (!cda[CTA_TIMEOUT_NAME]) {
 358                 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list,
 359                                          head)
 360                         ctnl_timeout_try_del(net, cur);
 361
 362                 return 0;
 363         }
 364         name = nla_data(cda[CTA_TIMEOUT_NAME]);
 365
 366         list_for_each_entry(cur, &net->nfct_timeout_list, head) {
 367                 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
 368                         continue;
 369
 370                 ret = ctnl_timeout_try_del(net, cur);
 371                 if (ret < 0)
 372                         return ret;
 373
 374                 break;
 375         }
 376         return ret;
 377 }
 378
 379 static int cttimeout_default_set(struct net *net, struct sock *ctnl,
 380                                  struct sk_buff *skb,
 381                                  const struct nlmsghdr *nlh,
 382                                  const struct nlattr * const cda[])
 383 {
 384         __u16 l3num;
 385         __u8 l4num;
 386         struct nf_conntrack_l4proto *l4proto;
 387         unsigned int *timeouts;
 388         int ret;
 389
 390         if (!cda[CTA_TIMEOUT_L3PROTO] ||
 391             !cda[CTA_TIMEOUT_L4PROTO] ||
 392             !cda[CTA_TIMEOUT_DATA])
 393                 return -EINVAL;
 394
 395         l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
 396         l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
 397         l4proto = nf_ct_l4proto_find_get(l3num, l4num);
 398
 399         /* This protocol is not supported, skip. */
 400         if (l4proto->l4proto != l4num) {
 401                 ret = -EOPNOTSUPP;
 402                 goto err;
 403         }
 404
 405         timeouts = l4proto->get_timeouts(net);
 406
 407         ret = ctnl_timeout_parse_policy(timeouts, l4proto, net,
 408                                         cda[CTA_TIMEOUT_DATA]);
 409         if (ret < 0)
 410                 goto err;
 411
 412         nf_ct_l4proto_put(l4proto);
 413         return 0;
 414 err:
 415         nf_ct_l4proto_put(l4proto);
 416         return ret;
 417 }
 418
 419 static int
 420 cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
 421                             u32 seq, u32 type, int event,
 422                             struct nf_conntrack_l4proto *l4proto)
 423 {
 424         struct nlmsghdr *nlh;
 425         struct nfgenmsg *nfmsg;
 426         unsigned int flags = portid ? NLM_F_MULTI : 0;
 427
 428         event |= NFNL_SUBSYS_CTNETLINK_TIMEOUT << 8;
 429         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
 430         if (nlh == NULL)
 431                 goto nlmsg_failure;
 432
 433         nfmsg = nlmsg_data(nlh);
 434         nfmsg->nfgen_family = AF_UNSPEC;
 435         nfmsg->version = NFNETLINK_V0;
 436         nfmsg->res_id = 0;
 437
 438         if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l4proto->l3proto)) ||
 439             nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
 440                 goto nla_put_failure;
 441
 442         if (likely(l4proto->ctnl_timeout.obj_to_nlattr)) {
 443                 struct nlattr *nest_parms;
 444                 unsigned int *timeouts = l4proto->get_timeouts(net);
 445                 int ret;
 446
 447                 nest_parms = nla_nest_start(skb,
 448                                             CTA_TIMEOUT_DATA | NLA_F_NESTED);
 449                 if (!nest_parms)
 450                         goto nla_put_failure;
 451
 452                 ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
 453                 if (ret < 0)
 454                         goto nla_put_failure;
 455
 456                 nla_nest_end(skb, nest_parms);
 457         }
 458
 459         nlmsg_end(skb, nlh);
 460         return skb->len;
 461
 462 nlmsg_failure:
 463 nla_put_failure:
 464         nlmsg_cancel(skb, nlh);
 465         return -1;
 466 }
 467
 468 static int cttimeout_default_get(struct net *net, struct sock *ctnl,
 469                                  struct sk_buff *skb,
 470                                  const struct nlmsghdr *nlh,
 471                                  const struct nlattr * const cda[])
 472 {
 473         __u16 l3num;
 474         __u8 l4num;
 475         struct nf_conntrack_l4proto *l4proto;
 476         struct sk_buff *skb2;
 477         int ret, err;
 478
 479         if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
 480                 return -EINVAL;
 481
 482         l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
 483         l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
 484         l4proto = nf_ct_l4proto_find_get(l3num, l4num);
 485
 486         /* This protocol is not supported, skip. */
 487         if (l4proto->l4proto != l4num) {
 488                 err = -EOPNOTSUPP;
 489                 goto err;
 490         }
 491
 492         skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 493         if (skb2 == NULL) {
 494                 err = -ENOMEM;
 495                 goto err;
 496         }
 497
 498         ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
 499                                           nlh->nlmsg_seq,
 500                                           NFNL_MSG_TYPE(nlh->nlmsg_type),
 501                                           IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
 502                                           l4proto);
 503         if (ret <= 0) {
 504                 kfree_skb(skb2);
 505                 err = -ENOMEM;
 506                 goto err;
 507         }
 508         ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
 509         if (ret > 0)
 510                 ret = 0;
 511
 512         /* this avoids a loop in nfnetlink. */
 513         return ret == -EAGAIN ? -ENOBUFS : ret;
 514 err:
 515         nf_ct_l4proto_put(l4proto);
 516         return err;
 517 }
 518
 519 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
 520 static struct ctnl_timeout *
 521 ctnl_timeout_find_get(struct net *net, const char *name)
 522 {
 523         struct ctnl_timeout *timeout, *matching = NULL;
 524
 525         rcu_read_lock();
 526         list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
 527                 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
 528                         continue;
 529
 530                 if (!try_module_get(THIS_MODULE))
 531                         goto err;
 532
 533                 if (!atomic_inc_not_zero(&timeout->refcnt)) {
 534                         module_put(THIS_MODULE);
 535                         goto err;
 536                 }
 537                 matching = timeout;
 538                 break;
 539         }
 540 err:
 541         rcu_read_unlock();
 542         return matching;
 543 }
 544
 545 static void ctnl_timeout_put(struct ctnl_timeout *timeout)
 546 {
 547         if (atomic_dec_and_test(&timeout->refcnt))
 548                 kfree_rcu(timeout, rcu_head);
 549
 550         module_put(THIS_MODULE);
 551 }
 552 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
 553
 554 static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
 555         [IPCTNL_MSG_TIMEOUT_NEW]        = { .call = cttimeout_new_timeout,
 556                                             .attr_count = CTA_TIMEOUT_MAX,
 557                                             .policy = cttimeout_nla_policy },
 558         [IPCTNL_MSG_TIMEOUT_GET]        = { .call = cttimeout_get_timeout,
 559                                             .attr_count = CTA_TIMEOUT_MAX,
 560                                             .policy = cttimeout_nla_policy },
 561         [IPCTNL_MSG_TIMEOUT_DELETE]     = { .call = cttimeout_del_timeout,
 562                                             .attr_count = CTA_TIMEOUT_MAX,
 563                                             .policy = cttimeout_nla_policy },
 564         [IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
 565                                             .attr_count = CTA_TIMEOUT_MAX,
 566                                             .policy = cttimeout_nla_policy },
 567         [IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
 568                                             .attr_count = CTA_TIMEOUT_MAX,
 569                                             .policy = cttimeout_nla_policy },
 570 };
 571
 572 static const struct nfnetlink_subsystem cttimeout_subsys = {
 573         .name                           = "conntrack_timeout",
 574         .subsys_id                      = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
 575         .cb_count                       = IPCTNL_MSG_TIMEOUT_MAX,
 576         .cb                             = cttimeout_cb,
 577 };
 578
 579 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
 580
 581 static int __net_init cttimeout_net_init(struct net *net)
 582 {
 583         INIT_LIST_HEAD(&net->nfct_timeout_list);
 584
 585         return 0;
 586 }
 587
 588 static void __net_exit cttimeout_net_exit(struct net *net)
 589 {
 590         struct ctnl_timeout *cur, *tmp;
 591
 592         ctnl_untimeout(net, NULL);
 593
 594         list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
 595                 list_del_rcu(&cur->head);
 596                 nf_ct_l4proto_put(cur->l4proto);
 597
 598                 if (atomic_dec_and_test(&cur->refcnt))
 599                         kfree_rcu(cur, rcu_head);
 600         }
 601 }
 602
 603 static struct pernet_operations cttimeout_ops = {
 604         .init   = cttimeout_net_init,
 605         .exit   = cttimeout_net_exit,
 606 };
 607
 608 static int __init cttimeout_init(void)
 609 {
 610         int ret;
 611
 612         ret = register_pernet_subsys(&cttimeout_ops);
 613         if (ret < 0)
 614                 return ret;
 615
 616         ret = nfnetlink_subsys_register(&cttimeout_subsys);
 617         if (ret < 0) {
 618                 pr_err("cttimeout_init: cannot register cttimeout with "
 619                         "nfnetlink.\n");
 620                 goto err_out;
 621         }
 622 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
 623         RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
 624         RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
 625 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
 626         return 0;
 627
 628 err_out:
 629         unregister_pernet_subsys(&cttimeout_ops);
 630         return ret;
 631 }
 632
 633 static void __exit cttimeout_exit(void)
 634 {
 635         pr_info("cttimeout: unregistering from nfnetlink.\n");
 636
 637         nfnetlink_subsys_unregister(&cttimeout_subsys);
 638
 639         unregister_pernet_subsys(&cttimeout_ops);
 640 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
 641         RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
 642         RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
 643 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
 644         rcu_barrier();
 645 }
 646
 647 module_init(cttimeout_init);
 648 module_exit(cttimeout_exit);