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