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         tb = kcalloc(l4proto->ctnl_timeout.nlattr_max + 1, sizeof(*tb),
  57                      GFP_KERNEL);
  58
  59         if (!tb)
  60                 return -ENOMEM;
  61
  62         ret = nla_parse_nested(tb, l4proto->ctnl_timeout.nlattr_max, attr,
  63                                l4proto->ctnl_timeout.nla_policy, NULL);
  64         if (ret < 0)
  65                 goto err;
  66
  67         ret = l4proto->ctnl_timeout.nlattr_to_obj(tb, net, timeout);
  68
  69 err:
  70         kfree(tb);
  71         return ret;
  72 }
  73
  74 static int cttimeout_new_timeout(struct net *net, struct sock *ctnl,
  75                                  struct sk_buff *skb,
  76                                  const struct nlmsghdr *nlh,
  77                                  const struct nlattr * const cda[],
  78                                  struct netlink_ext_ack *extack)
  79 {
  80         __u16 l3num;
  81         __u8 l4num;
  82         const struct nf_conntrack_l4proto *l4proto;
  83         struct ctnl_timeout *timeout, *matching = NULL;
  84         char *name;
  85         int ret;
  86
  87         if (!cda[CTA_TIMEOUT_NAME] ||
  88             !cda[CTA_TIMEOUT_L3PROTO] ||
  89             !cda[CTA_TIMEOUT_L4PROTO] ||
  90             !cda[CTA_TIMEOUT_DATA])
  91                 return -EINVAL;
  92
  93         name = nla_data(cda[CTA_TIMEOUT_NAME]);
  94         l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
  95         l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
  96
  97         list_for_each_entry(timeout, &net->nfct_timeout_list, head) {
  98                 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
  99                         continue;
 100
 101                 if (nlh->nlmsg_flags & NLM_F_EXCL)
 102                         return -EEXIST;
 103
 104                 matching = timeout;
 105                 break;
 106         }
 107
 108         if (matching) {
 109                 if (nlh->nlmsg_flags & NLM_F_REPLACE) {
 110                         /* You cannot replace one timeout policy by another of
 111                          * different kind, sorry.
 112                          */
 113                         if (matching->timeout.l3num != l3num ||
 114                             matching->timeout.l4proto->l4proto != l4num)
 115                                 return -EINVAL;
 116
 117                         return ctnl_timeout_parse_policy(&matching->timeout.data,
 118                                                          matching->timeout.l4proto,
 119                                                          net, cda[CTA_TIMEOUT_DATA]);
 120                 }
 121
 122                 return -EBUSY;
 123         }
 124
 125         l4proto = nf_ct_l4proto_find_get(l4num);
 126
 127         /* This protocol is not supportted, skip. */
 128         if (l4proto->l4proto != l4num) {
 129                 ret = -EOPNOTSUPP;
 130                 goto err_proto_put;
 131         }
 132
 133         timeout = kzalloc(sizeof(struct ctnl_timeout) +
 134                           l4proto->ctnl_timeout.obj_size, GFP_KERNEL);
 135         if (timeout == NULL) {
 136                 ret = -ENOMEM;
 137                 goto err_proto_put;
 138         }
 139
 140         ret = ctnl_timeout_parse_policy(&timeout->timeout.data, l4proto, net,
 141                                         cda[CTA_TIMEOUT_DATA]);
 142         if (ret < 0)
 143                 goto err;
 144
 145         strcpy(timeout->name, nla_data(cda[CTA_TIMEOUT_NAME]));
 146         timeout->timeout.l3num = l3num;
 147         timeout->timeout.l4proto = l4proto;
 148         refcount_set(&timeout->refcnt, 1);
 149         list_add_tail_rcu(&timeout->head, &net->nfct_timeout_list);
 150
 151         return 0;
 152 err:
 153         kfree(timeout);
 154 err_proto_put:
 155         nf_ct_l4proto_put(l4proto);
 156         return ret;
 157 }
 158
 159 static int
 160 ctnl_timeout_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
 161                        int event, struct ctnl_timeout *timeout)
 162 {
 163         struct nlmsghdr *nlh;
 164         struct nfgenmsg *nfmsg;
 165         unsigned int flags = portid ? NLM_F_MULTI : 0;
 166         const struct nf_conntrack_l4proto *l4proto = timeout->timeout.l4proto;
 167         struct nlattr *nest_parms;
 168         int ret;
 169
 170         event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
 171         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
 172         if (nlh == NULL)
 173                 goto nlmsg_failure;
 174
 175         nfmsg = nlmsg_data(nlh);
 176         nfmsg->nfgen_family = AF_UNSPEC;
 177         nfmsg->version = NFNETLINK_V0;
 178         nfmsg->res_id = 0;
 179
 180         if (nla_put_string(skb, CTA_TIMEOUT_NAME, timeout->name) ||
 181             nla_put_be16(skb, CTA_TIMEOUT_L3PROTO,
 182                          htons(timeout->timeout.l3num)) ||
 183             nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto) ||
 184             nla_put_be32(skb, CTA_TIMEOUT_USE,
 185                          htonl(refcount_read(&timeout->refcnt))))
 186                 goto nla_put_failure;
 187
 188         nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA | NLA_F_NESTED);
 189         if (!nest_parms)
 190                 goto nla_put_failure;
 191
 192         ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, &timeout->timeout.data);
 193         if (ret < 0)
 194                 goto nla_put_failure;
 195
 196         nla_nest_end(skb, nest_parms);
 197
 198         nlmsg_end(skb, nlh);
 199         return skb->len;
 200
 201 nlmsg_failure:
 202 nla_put_failure:
 203         nlmsg_cancel(skb, nlh);
 204         return -1;
 205 }
 206
 207 static int
 208 ctnl_timeout_dump(struct sk_buff *skb, struct netlink_callback *cb)
 209 {
 210         struct net *net = sock_net(skb->sk);
 211         struct ctnl_timeout *cur, *last;
 212
 213         if (cb->args[2])
 214                 return 0;
 215
 216         last = (struct ctnl_timeout *)cb->args[1];
 217         if (cb->args[1])
 218                 cb->args[1] = 0;
 219
 220         rcu_read_lock();
 221         list_for_each_entry_rcu(cur, &net->nfct_timeout_list, head) {
 222                 if (last) {
 223                         if (cur != last)
 224                                 continue;
 225
 226                         last = NULL;
 227                 }
 228                 if (ctnl_timeout_fill_info(skb, NETLINK_CB(cb->skb).portid,
 229                                            cb->nlh->nlmsg_seq,
 230                                            NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
 231                                            IPCTNL_MSG_TIMEOUT_NEW, cur) < 0) {
 232                         cb->args[1] = (unsigned long)cur;
 233                         break;
 234                 }
 235         }
 236         if (!cb->args[1])
 237                 cb->args[2] = 1;
 238         rcu_read_unlock();
 239         return skb->len;
 240 }
 241
 242 static int cttimeout_get_timeout(struct net *net, struct sock *ctnl,
 243                                  struct sk_buff *skb,
 244                                  const struct nlmsghdr *nlh,
 245                                  const struct nlattr * const cda[],
 246                                  struct netlink_ext_ack *extack)
 247 {
 248         int ret = -ENOENT;
 249         char *name;
 250         struct ctnl_timeout *cur;
 251
 252         if (nlh->nlmsg_flags & NLM_F_DUMP) {
 253                 struct netlink_dump_control c = {
 254                         .dump = ctnl_timeout_dump,
 255                 };
 256                 return netlink_dump_start(ctnl, skb, nlh, &c);
 257         }
 258
 259         if (!cda[CTA_TIMEOUT_NAME])
 260                 return -EINVAL;
 261         name = nla_data(cda[CTA_TIMEOUT_NAME]);
 262
 263         list_for_each_entry(cur, &net->nfct_timeout_list, head) {
 264                 struct sk_buff *skb2;
 265
 266                 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
 267                         continue;
 268
 269                 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 270                 if (skb2 == NULL) {
 271                         ret = -ENOMEM;
 272                         break;
 273                 }
 274
 275                 ret = ctnl_timeout_fill_info(skb2, NETLINK_CB(skb).portid,
 276                                              nlh->nlmsg_seq,
 277                                              NFNL_MSG_TYPE(nlh->nlmsg_type),
 278                                              IPCTNL_MSG_TIMEOUT_NEW, cur);
 279                 if (ret <= 0) {
 280                         kfree_skb(skb2);
 281                         break;
 282                 }
 283                 ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid,
 284                                         MSG_DONTWAIT);
 285                 if (ret > 0)
 286                         ret = 0;
 287
 288                 /* this avoids a loop in nfnetlink. */
 289                 return ret == -EAGAIN ? -ENOBUFS : ret;
 290         }
 291         return ret;
 292 }
 293
 294 /* try to delete object, fail if it is still in use. */
 295 static int ctnl_timeout_try_del(struct net *net, struct ctnl_timeout *timeout)
 296 {
 297         int ret = 0;
 298
 299         /* We want to avoid races with ctnl_timeout_put. So only when the
 300          * current refcnt is 1, we decrease it to 0.
 301          */
 302         if (refcount_dec_if_one(&timeout->refcnt)) {
 303                 /* We are protected by nfnl mutex. */
 304                 list_del_rcu(&timeout->head);
 305                 nf_ct_l4proto_put(timeout->timeout.l4proto);
 306                 nf_ct_untimeout(net, &timeout->timeout);
 307                 kfree_rcu(timeout, rcu_head);
 308         } else {
 309                 ret = -EBUSY;
 310         }
 311         return ret;
 312 }
 313
 314 static int cttimeout_del_timeout(struct net *net, struct sock *ctnl,
 315                                  struct sk_buff *skb,
 316                                  const struct nlmsghdr *nlh,
 317                                  const struct nlattr * const cda[],
 318                                  struct netlink_ext_ack *extack)
 319 {
 320         struct ctnl_timeout *cur, *tmp;
 321         int ret = -ENOENT;
 322         char *name;
 323
 324         if (!cda[CTA_TIMEOUT_NAME]) {
 325                 list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list,
 326                                          head)
 327                         ctnl_timeout_try_del(net, cur);
 328
 329                 return 0;
 330         }
 331         name = nla_data(cda[CTA_TIMEOUT_NAME]);
 332
 333         list_for_each_entry(cur, &net->nfct_timeout_list, head) {
 334                 if (strncmp(cur->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
 335                         continue;
 336
 337                 ret = ctnl_timeout_try_del(net, cur);
 338                 if (ret < 0)
 339                         return ret;
 340
 341                 break;
 342         }
 343         return ret;
 344 }
 345
 346 static int cttimeout_default_set(struct net *net, struct sock *ctnl,
 347                                  struct sk_buff *skb,
 348                                  const struct nlmsghdr *nlh,
 349                                  const struct nlattr * const cda[],
 350                                  struct netlink_ext_ack *extack)
 351 {
 352         const struct nf_conntrack_l4proto *l4proto;
 353         __u8 l4num;
 354         int ret;
 355
 356         if (!cda[CTA_TIMEOUT_L3PROTO] ||
 357             !cda[CTA_TIMEOUT_L4PROTO] ||
 358             !cda[CTA_TIMEOUT_DATA])
 359                 return -EINVAL;
 360
 361         l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
 362         l4proto = nf_ct_l4proto_find_get(l4num);
 363
 364         /* This protocol is not supported, skip. */
 365         if (l4proto->l4proto != l4num) {
 366                 ret = -EOPNOTSUPP;
 367                 goto err;
 368         }
 369
 370         ret = ctnl_timeout_parse_policy(NULL, l4proto, net,
 371                                         cda[CTA_TIMEOUT_DATA]);
 372         if (ret < 0)
 373                 goto err;
 374
 375         nf_ct_l4proto_put(l4proto);
 376         return 0;
 377 err:
 378         nf_ct_l4proto_put(l4proto);
 379         return ret;
 380 }
 381
 382 static int
 383 cttimeout_default_fill_info(struct net *net, struct sk_buff *skb, u32 portid,
 384                             u32 seq, u32 type, int event, u16 l3num,
 385                             const struct nf_conntrack_l4proto *l4proto,
 386                             const unsigned int *timeouts)
 387 {
 388         struct nlmsghdr *nlh;
 389         struct nfgenmsg *nfmsg;
 390         unsigned int flags = portid ? NLM_F_MULTI : 0;
 391         struct nlattr *nest_parms;
 392         int ret;
 393
 394         event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_TIMEOUT, event);
 395         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nfmsg), flags);
 396         if (nlh == NULL)
 397                 goto nlmsg_failure;
 398
 399         nfmsg = nlmsg_data(nlh);
 400         nfmsg->nfgen_family = AF_UNSPEC;
 401         nfmsg->version = NFNETLINK_V0;
 402         nfmsg->res_id = 0;
 403
 404         if (nla_put_be16(skb, CTA_TIMEOUT_L3PROTO, htons(l3num)) ||
 405             nla_put_u8(skb, CTA_TIMEOUT_L4PROTO, l4proto->l4proto))
 406                 goto nla_put_failure;
 407
 408         nest_parms = nla_nest_start(skb, CTA_TIMEOUT_DATA | NLA_F_NESTED);
 409         if (!nest_parms)
 410                 goto nla_put_failure;
 411
 412         ret = l4proto->ctnl_timeout.obj_to_nlattr(skb, timeouts);
 413         if (ret < 0)
 414                 goto nla_put_failure;
 415
 416         nla_nest_end(skb, nest_parms);
 417
 418         nlmsg_end(skb, nlh);
 419         return skb->len;
 420
 421 nlmsg_failure:
 422 nla_put_failure:
 423         nlmsg_cancel(skb, nlh);
 424         return -1;
 425 }
 426
 427 static int cttimeout_default_get(struct net *net, struct sock *ctnl,
 428                                  struct sk_buff *skb,
 429                                  const struct nlmsghdr *nlh,
 430                                  const struct nlattr * const cda[],
 431                                  struct netlink_ext_ack *extack)
 432 {
 433         const struct nf_conntrack_l4proto *l4proto;
 434         unsigned int *timeouts = NULL;
 435         struct sk_buff *skb2;
 436         int ret, err;
 437         __u16 l3num;
 438         __u8 l4num;
 439
 440         if (!cda[CTA_TIMEOUT_L3PROTO] || !cda[CTA_TIMEOUT_L4PROTO])
 441                 return -EINVAL;
 442
 443         l3num = ntohs(nla_get_be16(cda[CTA_TIMEOUT_L3PROTO]));
 444         l4num = nla_get_u8(cda[CTA_TIMEOUT_L4PROTO]);
 445         l4proto = nf_ct_l4proto_find_get(l4num);
 446
 447         err = -EOPNOTSUPP;
 448         if (l4proto->l4proto != l4num)
 449                 goto err;
 450
 451         switch (l4proto->l4proto) {
 452         case IPPROTO_ICMP:
 453                 timeouts = &nf_icmp_pernet(net)->timeout;
 454                 break;
 455         case IPPROTO_TCP:
 456                 timeouts = nf_tcp_pernet(net)->timeouts;
 457                 break;
 458         case IPPROTO_UDP: /* fallthrough */
 459         case IPPROTO_UDPLITE:
 460                 timeouts = nf_udp_pernet(net)->timeouts;
 461                 break;
 462         case IPPROTO_DCCP:
 463 #ifdef CONFIG_NF_CT_PROTO_DCCP
 464                 timeouts = nf_dccp_pernet(net)->dccp_timeout;
 465 #endif
 466                 break;
 467         case IPPROTO_ICMPV6:
 468                 timeouts = &nf_icmpv6_pernet(net)->timeout;
 469                 break;
 470         case IPPROTO_SCTP:
 471 #ifdef CONFIG_NF_CT_PROTO_SCTP
 472                 timeouts = nf_sctp_pernet(net)->timeouts;
 473 #endif
 474                 break;
 475         case IPPROTO_GRE:
 476 #ifdef CONFIG_NF_CT_PROTO_GRE
 477                 if (l4proto->net_id) {
 478                         struct netns_proto_gre *net_gre;
 479
 480                         net_gre = net_generic(net, *l4proto->net_id);
 481                         timeouts = net_gre->gre_timeouts;
 482                 }
 483 #endif
 484                 break;
 485         case 255:
 486                 timeouts = &nf_generic_pernet(net)->timeout;
 487                 break;
 488         default:
 489                 WARN_ONCE(1, "Missing timeouts for proto %d", l4proto->l4proto);
 490                 break;
 491         }
 492
 493         if (!timeouts)
 494                 goto err;
 495
 496         skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 497         if (skb2 == NULL) {
 498                 err = -ENOMEM;
 499                 goto err;
 500         }
 501
 502         ret = cttimeout_default_fill_info(net, skb2, NETLINK_CB(skb).portid,
 503                                           nlh->nlmsg_seq,
 504                                           NFNL_MSG_TYPE(nlh->nlmsg_type),
 505                                           IPCTNL_MSG_TIMEOUT_DEFAULT_SET,
 506                                           l3num, l4proto, timeouts);
 507         if (ret <= 0) {
 508                 kfree_skb(skb2);
 509                 err = -ENOMEM;
 510                 goto err;
 511         }
 512         ret = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
 513         if (ret > 0)
 514                 ret = 0;
 515
 516         /* this avoids a loop in nfnetlink. */
 517         return ret == -EAGAIN ? -ENOBUFS : ret;
 518 err:
 519         nf_ct_l4proto_put(l4proto);
 520         return err;
 521 }
 522
 523 static struct nf_ct_timeout *ctnl_timeout_find_get(struct net *net,
 524                                                    const char *name)
 525 {
 526         struct ctnl_timeout *timeout, *matching = NULL;
 527
 528         list_for_each_entry_rcu(timeout, &net->nfct_timeout_list, head) {
 529                 if (strncmp(timeout->name, name, CTNL_TIMEOUT_NAME_MAX) != 0)
 530                         continue;
 531
 532                 if (!try_module_get(THIS_MODULE))
 533                         goto err;
 534
 535                 if (!refcount_inc_not_zero(&timeout->refcnt)) {
 536                         module_put(THIS_MODULE);
 537                         goto err;
 538                 }
 539                 matching = timeout;
 540                 break;
 541         }
 542 err:
 543         return matching ? &matching->timeout : NULL;
 544 }
 545
 546 static void ctnl_timeout_put(struct nf_ct_timeout *t)
 547 {
 548         struct ctnl_timeout *timeout =
 549                 container_of(t, struct ctnl_timeout, timeout);
 550
 551         if (refcount_dec_and_test(&timeout->refcnt))
 552                 kfree_rcu(timeout, rcu_head);
 553
 554         module_put(THIS_MODULE);
 555 }
 556
 557 static const struct nfnl_callback cttimeout_cb[IPCTNL_MSG_TIMEOUT_MAX] = {
 558         [IPCTNL_MSG_TIMEOUT_NEW]        = { .call = cttimeout_new_timeout,
 559                                             .attr_count = CTA_TIMEOUT_MAX,
 560                                             .policy = cttimeout_nla_policy },
 561         [IPCTNL_MSG_TIMEOUT_GET]        = { .call = cttimeout_get_timeout,
 562                                             .attr_count = CTA_TIMEOUT_MAX,
 563                                             .policy = cttimeout_nla_policy },
 564         [IPCTNL_MSG_TIMEOUT_DELETE]     = { .call = cttimeout_del_timeout,
 565                                             .attr_count = CTA_TIMEOUT_MAX,
 566                                             .policy = cttimeout_nla_policy },
 567         [IPCTNL_MSG_TIMEOUT_DEFAULT_SET]= { .call = cttimeout_default_set,
 568                                             .attr_count = CTA_TIMEOUT_MAX,
 569                                             .policy = cttimeout_nla_policy },
 570         [IPCTNL_MSG_TIMEOUT_DEFAULT_GET]= { .call = cttimeout_default_get,
 571                                             .attr_count = CTA_TIMEOUT_MAX,
 572                                             .policy = cttimeout_nla_policy },
 573 };
 574
 575 static const struct nfnetlink_subsystem cttimeout_subsys = {
 576         .name                           = "conntrack_timeout",
 577         .subsys_id                      = NFNL_SUBSYS_CTNETLINK_TIMEOUT,
 578         .cb_count                       = IPCTNL_MSG_TIMEOUT_MAX,
 579         .cb                             = cttimeout_cb,
 580 };
 581
 582 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_TIMEOUT);
 583
 584 static int __net_init cttimeout_net_init(struct net *net)
 585 {
 586         INIT_LIST_HEAD(&net->nfct_timeout_list);
 587
 588         return 0;
 589 }
 590
 591 static void __net_exit cttimeout_net_exit(struct net *net)
 592 {
 593         struct ctnl_timeout *cur, *tmp;
 594
 595         nf_ct_unconfirmed_destroy(net);
 596         nf_ct_untimeout(net, NULL);
 597
 598         list_for_each_entry_safe(cur, tmp, &net->nfct_timeout_list, head) {
 599                 list_del_rcu(&cur->head);
 600                 nf_ct_l4proto_put(cur->timeout.l4proto);
 601
 602                 if (refcount_dec_and_test(&cur->refcnt))
 603                         kfree_rcu(cur, rcu_head);
 604         }
 605 }
 606
 607 static struct pernet_operations cttimeout_ops = {
 608         .init   = cttimeout_net_init,
 609         .exit   = cttimeout_net_exit,
 610 };
 611
 612 static int __init cttimeout_init(void)
 613 {
 614         int ret;
 615
 616         ret = register_pernet_subsys(&cttimeout_ops);
 617         if (ret < 0)
 618                 return ret;
 619
 620         ret = nfnetlink_subsys_register(&cttimeout_subsys);
 621         if (ret < 0) {
 622                 pr_err("cttimeout_init: cannot register cttimeout with "
 623                         "nfnetlink.\n");
 624                 goto err_out;
 625         }
 626         RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, ctnl_timeout_find_get);
 627         RCU_INIT_POINTER(nf_ct_timeout_put_hook, ctnl_timeout_put);
 628         return 0;
 629
 630 err_out:
 631         unregister_pernet_subsys(&cttimeout_ops);
 632         return ret;
 633 }
 634
 635 static void __exit cttimeout_exit(void)
 636 {
 637         nfnetlink_subsys_unregister(&cttimeout_subsys);
 638
 639         unregister_pernet_subsys(&cttimeout_ops);
 640         RCU_INIT_POINTER(nf_ct_timeout_find_get_hook, NULL);
 641         RCU_INIT_POINTER(nf_ct_timeout_put_hook, NULL);
 642         synchronize_rcu();
 643 }
 644
 645 module_init(cttimeout_init);
 646 module_exit(cttimeout_exit);