1 /* Netfilter messages via netlink socket. Allows for user space 2 * protocol helpers and general trouble making from userspace. 3 * 4 * (C) 2001 by Jay Schulist <jschlst@samba.org>, 5 * (C) 2002-2005 by Harald Welte <laforge@gnumonks.org> 6 * (C) 2005-2017 by Pablo Neira Ayuso <pablo@netfilter.org> 7 * 8 * Initial netfilter messages via netlink development funded and 9 * generally made possible by Network Robots, Inc. (www.networkrobots.com) 10 * 11 * Further development of this code funded by Astaro AG (http://www.astaro.com) 12 * 13 * This software may be used and distributed according to the terms 14 * of the GNU General Public License, incorporated herein by reference. 15 */ 16 17 #include <linux/module.h> 18 #include <linux/types.h> 19 #include <linux/socket.h> 20 #include <linux/kernel.h> 21 #include <linux/string.h> 22 #include <linux/sockios.h> 23 #include <linux/net.h> 24 #include <linux/skbuff.h> 25 #include <linux/uaccess.h> 26 #include <net/sock.h> 27 #include <linux/init.h> 28 #include <linux/sched/signal.h> 29 30 #include <net/netlink.h> 31 #include <linux/netfilter/nfnetlink.h> 32 33 MODULE_LICENSE("GPL"); 34 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); 35 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER); 36 37 #define nfnl_dereference_protected(id) \ 38 rcu_dereference_protected(table[(id)].subsys, \ 39 lockdep_nfnl_is_held((id))) 40 41 #define NFNL_MAX_ATTR_COUNT 32 42 43 static struct { 44 struct mutex mutex; 45 const struct nfnetlink_subsystem __rcu *subsys; 46 } table[NFNL_SUBSYS_COUNT]; 47 48 static const int nfnl_group2type[NFNLGRP_MAX+1] = { 49 [NFNLGRP_CONNTRACK_NEW] = NFNL_SUBSYS_CTNETLINK, 50 [NFNLGRP_CONNTRACK_UPDATE] = NFNL_SUBSYS_CTNETLINK, 51 [NFNLGRP_CONNTRACK_DESTROY] = NFNL_SUBSYS_CTNETLINK, 52 [NFNLGRP_CONNTRACK_EXP_NEW] = NFNL_SUBSYS_CTNETLINK_EXP, 53 [NFNLGRP_CONNTRACK_EXP_UPDATE] = NFNL_SUBSYS_CTNETLINK_EXP, 54 [NFNLGRP_CONNTRACK_EXP_DESTROY] = NFNL_SUBSYS_CTNETLINK_EXP, 55 [NFNLGRP_NFTABLES] = NFNL_SUBSYS_NFTABLES, 56 [NFNLGRP_ACCT_QUOTA] = NFNL_SUBSYS_ACCT, 57 [NFNLGRP_NFTRACE] = NFNL_SUBSYS_NFTABLES, 58 }; 59 nfnl_lock(__u8 subsys_id)60 void nfnl_lock(__u8 subsys_id) 61 { 62 mutex_lock(&table[subsys_id].mutex); 63 } 64 EXPORT_SYMBOL_GPL(nfnl_lock); 65 nfnl_unlock(__u8 subsys_id)66 void nfnl_unlock(__u8 subsys_id) 67 { 68 mutex_unlock(&table[subsys_id].mutex); 69 } 70 EXPORT_SYMBOL_GPL(nfnl_unlock); 71 72 #ifdef CONFIG_PROVE_LOCKING lockdep_nfnl_is_held(u8 subsys_id)73 bool lockdep_nfnl_is_held(u8 subsys_id) 74 { 75 return lockdep_is_held(&table[subsys_id].mutex); 76 } 77 EXPORT_SYMBOL_GPL(lockdep_nfnl_is_held); 78 #endif 79 nfnetlink_subsys_register(const struct nfnetlink_subsystem * n)80 int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n) 81 { 82 u8 cb_id; 83 84 /* Sanity-check attr_count size to avoid stack buffer overflow. */ 85 for (cb_id = 0; cb_id < n->cb_count; cb_id++) 86 if (WARN_ON(n->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT)) 87 return -EINVAL; 88 89 nfnl_lock(n->subsys_id); 90 if (table[n->subsys_id].subsys) { 91 nfnl_unlock(n->subsys_id); 92 return -EBUSY; 93 } 94 rcu_assign_pointer(table[n->subsys_id].subsys, n); 95 nfnl_unlock(n->subsys_id); 96 97 return 0; 98 } 99 EXPORT_SYMBOL_GPL(nfnetlink_subsys_register); 100 nfnetlink_subsys_unregister(const struct nfnetlink_subsystem * n)101 int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n) 102 { 103 nfnl_lock(n->subsys_id); 104 table[n->subsys_id].subsys = NULL; 105 nfnl_unlock(n->subsys_id); 106 synchronize_rcu(); 107 return 0; 108 } 109 EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister); 110 nfnetlink_get_subsys(u16 type)111 static inline const struct nfnetlink_subsystem *nfnetlink_get_subsys(u16 type) 112 { 113 u8 subsys_id = NFNL_SUBSYS_ID(type); 114 115 if (subsys_id >= NFNL_SUBSYS_COUNT) 116 return NULL; 117 118 return rcu_dereference(table[subsys_id].subsys); 119 } 120 121 static inline const struct nfnl_callback * nfnetlink_find_client(u16 type,const struct nfnetlink_subsystem * ss)122 nfnetlink_find_client(u16 type, const struct nfnetlink_subsystem *ss) 123 { 124 u8 cb_id = NFNL_MSG_TYPE(type); 125 126 if (cb_id >= ss->cb_count) 127 return NULL; 128 129 return &ss->cb[cb_id]; 130 } 131 nfnetlink_has_listeners(struct net * net,unsigned int group)132 int nfnetlink_has_listeners(struct net *net, unsigned int group) 133 { 134 return netlink_has_listeners(net->nfnl, group); 135 } 136 EXPORT_SYMBOL_GPL(nfnetlink_has_listeners); 137 nfnetlink_send(struct sk_buff * skb,struct net * net,u32 portid,unsigned int group,int echo,gfp_t flags)138 int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid, 139 unsigned int group, int echo, gfp_t flags) 140 { 141 return nlmsg_notify(net->nfnl, skb, portid, group, echo, flags); 142 } 143 EXPORT_SYMBOL_GPL(nfnetlink_send); 144 nfnetlink_set_err(struct net * net,u32 portid,u32 group,int error)145 int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error) 146 { 147 return netlink_set_err(net->nfnl, portid, group, error); 148 } 149 EXPORT_SYMBOL_GPL(nfnetlink_set_err); 150 nfnetlink_unicast(struct sk_buff * skb,struct net * net,u32 portid)151 int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid) 152 { 153 int err; 154 155 err = nlmsg_unicast(net->nfnl, skb, portid); 156 if (err == -EAGAIN) 157 err = -ENOBUFS; 158 159 return err; 160 } 161 EXPORT_SYMBOL_GPL(nfnetlink_unicast); 162 163 /* Process one complete nfnetlink message. */ nfnetlink_rcv_msg(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)164 static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, 165 struct netlink_ext_ack *extack) 166 { 167 struct net *net = sock_net(skb->sk); 168 const struct nfnl_callback *nc; 169 const struct nfnetlink_subsystem *ss; 170 int type, err; 171 172 /* All the messages must at least contain nfgenmsg */ 173 if (nlmsg_len(nlh) < sizeof(struct nfgenmsg)) 174 return 0; 175 176 type = nlh->nlmsg_type; 177 replay: 178 rcu_read_lock(); 179 ss = nfnetlink_get_subsys(type); 180 if (!ss) { 181 #ifdef CONFIG_MODULES 182 rcu_read_unlock(); 183 request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type)); 184 rcu_read_lock(); 185 ss = nfnetlink_get_subsys(type); 186 if (!ss) 187 #endif 188 { 189 rcu_read_unlock(); 190 return -EINVAL; 191 } 192 } 193 194 nc = nfnetlink_find_client(type, ss); 195 if (!nc) { 196 rcu_read_unlock(); 197 return -EINVAL; 198 } 199 200 { 201 int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); 202 u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); 203 struct nlattr *cda[NFNL_MAX_ATTR_COUNT + 1]; 204 struct nlattr *attr = (void *)nlh + min_len; 205 int attrlen = nlh->nlmsg_len - min_len; 206 __u8 subsys_id = NFNL_SUBSYS_ID(type); 207 208 /* Sanity-check NFNL_MAX_ATTR_COUNT */ 209 if (ss->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT) { 210 rcu_read_unlock(); 211 return -ENOMEM; 212 } 213 214 err = nla_parse_deprecated(cda, ss->cb[cb_id].attr_count, 215 attr, attrlen, 216 ss->cb[cb_id].policy, extack); 217 if (err < 0) { 218 rcu_read_unlock(); 219 return err; 220 } 221 222 if (nc->call_rcu) { 223 err = nc->call_rcu(net, net->nfnl, skb, nlh, 224 (const struct nlattr **)cda, 225 extack); 226 rcu_read_unlock(); 227 } else { 228 rcu_read_unlock(); 229 nfnl_lock(subsys_id); 230 if (nfnl_dereference_protected(subsys_id) != ss || 231 nfnetlink_find_client(type, ss) != nc) 232 err = -EAGAIN; 233 else if (nc->call) 234 err = nc->call(net, net->nfnl, skb, nlh, 235 (const struct nlattr **)cda, 236 extack); 237 else 238 err = -EINVAL; 239 nfnl_unlock(subsys_id); 240 } 241 if (err == -EAGAIN) 242 goto replay; 243 return err; 244 } 245 } 246 247 struct nfnl_err { 248 struct list_head head; 249 struct nlmsghdr *nlh; 250 int err; 251 struct netlink_ext_ack extack; 252 }; 253 nfnl_err_add(struct list_head * list,struct nlmsghdr * nlh,int err,const struct netlink_ext_ack * extack)254 static int nfnl_err_add(struct list_head *list, struct nlmsghdr *nlh, int err, 255 const struct netlink_ext_ack *extack) 256 { 257 struct nfnl_err *nfnl_err; 258 259 nfnl_err = kmalloc(sizeof(struct nfnl_err), GFP_KERNEL); 260 if (nfnl_err == NULL) 261 return -ENOMEM; 262 263 nfnl_err->nlh = nlh; 264 nfnl_err->err = err; 265 nfnl_err->extack = *extack; 266 list_add_tail(&nfnl_err->head, list); 267 268 return 0; 269 } 270 nfnl_err_del(struct nfnl_err * nfnl_err)271 static void nfnl_err_del(struct nfnl_err *nfnl_err) 272 { 273 list_del(&nfnl_err->head); 274 kfree(nfnl_err); 275 } 276 nfnl_err_reset(struct list_head * err_list)277 static void nfnl_err_reset(struct list_head *err_list) 278 { 279 struct nfnl_err *nfnl_err, *next; 280 281 list_for_each_entry_safe(nfnl_err, next, err_list, head) 282 nfnl_err_del(nfnl_err); 283 } 284 nfnl_err_deliver(struct list_head * err_list,struct sk_buff * skb)285 static void nfnl_err_deliver(struct list_head *err_list, struct sk_buff *skb) 286 { 287 struct nfnl_err *nfnl_err, *next; 288 289 list_for_each_entry_safe(nfnl_err, next, err_list, head) { 290 netlink_ack(skb, nfnl_err->nlh, nfnl_err->err, 291 &nfnl_err->extack); 292 nfnl_err_del(nfnl_err); 293 } 294 } 295 296 enum { 297 NFNL_BATCH_FAILURE = (1 << 0), 298 NFNL_BATCH_DONE = (1 << 1), 299 NFNL_BATCH_REPLAY = (1 << 2), 300 }; 301 nfnetlink_rcv_batch(struct sk_buff * skb,struct nlmsghdr * nlh,u16 subsys_id,u32 genid)302 static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh, 303 u16 subsys_id, u32 genid) 304 { 305 struct sk_buff *oskb = skb; 306 struct net *net = sock_net(skb->sk); 307 const struct nfnetlink_subsystem *ss; 308 const struct nfnl_callback *nc; 309 struct netlink_ext_ack extack; 310 LIST_HEAD(err_list); 311 u32 status; 312 int err; 313 314 if (subsys_id >= NFNL_SUBSYS_COUNT) 315 return netlink_ack(skb, nlh, -EINVAL, NULL); 316 replay: 317 status = 0; 318 replay_abort: 319 skb = netlink_skb_clone(oskb, GFP_KERNEL); 320 if (!skb) 321 return netlink_ack(oskb, nlh, -ENOMEM, NULL); 322 323 nfnl_lock(subsys_id); 324 ss = nfnl_dereference_protected(subsys_id); 325 if (!ss) { 326 #ifdef CONFIG_MODULES 327 nfnl_unlock(subsys_id); 328 request_module("nfnetlink-subsys-%d", subsys_id); 329 nfnl_lock(subsys_id); 330 ss = nfnl_dereference_protected(subsys_id); 331 if (!ss) 332 #endif 333 { 334 nfnl_unlock(subsys_id); 335 netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL); 336 return kfree_skb(skb); 337 } 338 } 339 340 if (!ss->valid_genid || !ss->commit || !ss->abort) { 341 nfnl_unlock(subsys_id); 342 netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL); 343 return kfree_skb(skb); 344 } 345 346 if (!try_module_get(ss->owner)) { 347 nfnl_unlock(subsys_id); 348 netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL); 349 return kfree_skb(skb); 350 } 351 352 if (!ss->valid_genid(net, genid)) { 353 module_put(ss->owner); 354 nfnl_unlock(subsys_id); 355 netlink_ack(oskb, nlh, -ERESTART, NULL); 356 return kfree_skb(skb); 357 } 358 359 nfnl_unlock(subsys_id); 360 361 while (skb->len >= nlmsg_total_size(0)) { 362 int msglen, type; 363 364 if (fatal_signal_pending(current)) { 365 nfnl_err_reset(&err_list); 366 err = -EINTR; 367 status = NFNL_BATCH_FAILURE; 368 goto done; 369 } 370 371 memset(&extack, 0, sizeof(extack)); 372 nlh = nlmsg_hdr(skb); 373 err = 0; 374 375 if (nlh->nlmsg_len < NLMSG_HDRLEN || 376 skb->len < nlh->nlmsg_len || 377 nlmsg_len(nlh) < sizeof(struct nfgenmsg)) { 378 nfnl_err_reset(&err_list); 379 status |= NFNL_BATCH_FAILURE; 380 goto done; 381 } 382 383 /* Only requests are handled by the kernel */ 384 if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) { 385 err = -EINVAL; 386 goto ack; 387 } 388 389 type = nlh->nlmsg_type; 390 if (type == NFNL_MSG_BATCH_BEGIN) { 391 /* Malformed: Batch begin twice */ 392 nfnl_err_reset(&err_list); 393 status |= NFNL_BATCH_FAILURE; 394 goto done; 395 } else if (type == NFNL_MSG_BATCH_END) { 396 status |= NFNL_BATCH_DONE; 397 goto done; 398 } else if (type < NLMSG_MIN_TYPE) { 399 err = -EINVAL; 400 goto ack; 401 } 402 403 /* We only accept a batch with messages for the same 404 * subsystem. 405 */ 406 if (NFNL_SUBSYS_ID(type) != subsys_id) { 407 err = -EINVAL; 408 goto ack; 409 } 410 411 nc = nfnetlink_find_client(type, ss); 412 if (!nc) { 413 err = -EINVAL; 414 goto ack; 415 } 416 417 { 418 int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); 419 u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); 420 struct nlattr *cda[NFNL_MAX_ATTR_COUNT + 1]; 421 struct nlattr *attr = (void *)nlh + min_len; 422 int attrlen = nlh->nlmsg_len - min_len; 423 424 /* Sanity-check NFTA_MAX_ATTR */ 425 if (ss->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT) { 426 err = -ENOMEM; 427 goto ack; 428 } 429 430 err = nla_parse_deprecated(cda, 431 ss->cb[cb_id].attr_count, 432 attr, attrlen, 433 ss->cb[cb_id].policy, NULL); 434 if (err < 0) 435 goto ack; 436 437 if (nc->call_batch) { 438 err = nc->call_batch(net, net->nfnl, skb, nlh, 439 (const struct nlattr **)cda, 440 &extack); 441 } 442 443 /* The lock was released to autoload some module, we 444 * have to abort and start from scratch using the 445 * original skb. 446 */ 447 if (err == -EAGAIN) { 448 status |= NFNL_BATCH_REPLAY; 449 goto done; 450 } 451 } 452 ack: 453 if (nlh->nlmsg_flags & NLM_F_ACK || err) { 454 /* Errors are delivered once the full batch has been 455 * processed, this avoids that the same error is 456 * reported several times when replaying the batch. 457 */ 458 if (err == -ENOMEM || 459 nfnl_err_add(&err_list, nlh, err, &extack) < 0) { 460 /* We failed to enqueue an error, reset the 461 * list of errors and send OOM to userspace 462 * pointing to the batch header. 463 */ 464 nfnl_err_reset(&err_list); 465 netlink_ack(oskb, nlmsg_hdr(oskb), -ENOMEM, 466 NULL); 467 status |= NFNL_BATCH_FAILURE; 468 goto done; 469 } 470 /* We don't stop processing the batch on errors, thus, 471 * userspace gets all the errors that the batch 472 * triggers. 473 */ 474 if (err) 475 status |= NFNL_BATCH_FAILURE; 476 } 477 478 msglen = NLMSG_ALIGN(nlh->nlmsg_len); 479 if (msglen > skb->len) 480 msglen = skb->len; 481 skb_pull(skb, msglen); 482 } 483 done: 484 if (status & NFNL_BATCH_REPLAY) { 485 ss->abort(net, oskb, NFNL_ABORT_AUTOLOAD); 486 nfnl_err_reset(&err_list); 487 kfree_skb(skb); 488 module_put(ss->owner); 489 goto replay; 490 } else if (status == NFNL_BATCH_DONE) { 491 err = ss->commit(net, oskb); 492 if (err == -EAGAIN) { 493 status |= NFNL_BATCH_REPLAY; 494 goto done; 495 } else if (err) { 496 ss->abort(net, oskb, NFNL_ABORT_NONE); 497 netlink_ack(oskb, nlmsg_hdr(oskb), err, NULL); 498 } 499 } else { 500 enum nfnl_abort_action abort_action; 501 502 if (status & NFNL_BATCH_FAILURE) 503 abort_action = NFNL_ABORT_NONE; 504 else 505 abort_action = NFNL_ABORT_VALIDATE; 506 507 err = ss->abort(net, oskb, abort_action); 508 if (err == -EAGAIN) { 509 nfnl_err_reset(&err_list); 510 kfree_skb(skb); 511 module_put(ss->owner); 512 status |= NFNL_BATCH_FAILURE; 513 goto replay_abort; 514 } 515 } 516 if (ss->cleanup) 517 ss->cleanup(net); 518 519 nfnl_err_deliver(&err_list, oskb); 520 kfree_skb(skb); 521 module_put(ss->owner); 522 } 523 524 static const struct nla_policy nfnl_batch_policy[NFNL_BATCH_MAX + 1] = { 525 [NFNL_BATCH_GENID] = { .type = NLA_U32 }, 526 }; 527 nfnetlink_rcv_skb_batch(struct sk_buff * skb,struct nlmsghdr * nlh)528 static void nfnetlink_rcv_skb_batch(struct sk_buff *skb, struct nlmsghdr *nlh) 529 { 530 int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); 531 struct nlattr *attr = (void *)nlh + min_len; 532 struct nlattr *cda[NFNL_BATCH_MAX + 1]; 533 int attrlen = nlh->nlmsg_len - min_len; 534 struct nfgenmsg *nfgenmsg; 535 int msglen, err; 536 u32 gen_id = 0; 537 u16 res_id; 538 539 msglen = NLMSG_ALIGN(nlh->nlmsg_len); 540 if (msglen > skb->len) 541 msglen = skb->len; 542 543 if (skb->len < NLMSG_HDRLEN + sizeof(struct nfgenmsg)) 544 return; 545 546 err = nla_parse_deprecated(cda, NFNL_BATCH_MAX, attr, attrlen, 547 nfnl_batch_policy, NULL); 548 if (err < 0) { 549 netlink_ack(skb, nlh, err, NULL); 550 return; 551 } 552 if (cda[NFNL_BATCH_GENID]) 553 gen_id = ntohl(nla_get_be32(cda[NFNL_BATCH_GENID])); 554 555 nfgenmsg = nlmsg_data(nlh); 556 skb_pull(skb, msglen); 557 /* Work around old nft using host byte order */ 558 if (nfgenmsg->res_id == NFNL_SUBSYS_NFTABLES) 559 res_id = NFNL_SUBSYS_NFTABLES; 560 else 561 res_id = ntohs(nfgenmsg->res_id); 562 563 nfnetlink_rcv_batch(skb, nlh, res_id, gen_id); 564 } 565 nfnetlink_rcv(struct sk_buff * skb)566 static void nfnetlink_rcv(struct sk_buff *skb) 567 { 568 struct nlmsghdr *nlh = nlmsg_hdr(skb); 569 570 if (skb->len < NLMSG_HDRLEN || 571 nlh->nlmsg_len < NLMSG_HDRLEN || 572 skb->len < nlh->nlmsg_len) 573 return; 574 575 if (!netlink_net_capable(skb, CAP_NET_ADMIN)) { 576 netlink_ack(skb, nlh, -EPERM, NULL); 577 return; 578 } 579 580 if (nlh->nlmsg_type == NFNL_MSG_BATCH_BEGIN) 581 nfnetlink_rcv_skb_batch(skb, nlh); 582 else 583 netlink_rcv_skb(skb, nfnetlink_rcv_msg); 584 } 585 586 #ifdef CONFIG_MODULES nfnetlink_bind(struct net * net,int group)587 static int nfnetlink_bind(struct net *net, int group) 588 { 589 const struct nfnetlink_subsystem *ss; 590 int type; 591 592 if (group <= NFNLGRP_NONE || group > NFNLGRP_MAX) 593 return 0; 594 595 type = nfnl_group2type[group]; 596 597 rcu_read_lock(); 598 ss = nfnetlink_get_subsys(type << 8); 599 rcu_read_unlock(); 600 if (!ss) 601 request_module_nowait("nfnetlink-subsys-%d", type); 602 return 0; 603 } 604 #endif 605 nfnetlink_net_init(struct net * net)606 static int __net_init nfnetlink_net_init(struct net *net) 607 { 608 struct sock *nfnl; 609 struct netlink_kernel_cfg cfg = { 610 .groups = NFNLGRP_MAX, 611 .input = nfnetlink_rcv, 612 #ifdef CONFIG_MODULES 613 .bind = nfnetlink_bind, 614 #endif 615 }; 616 617 nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, &cfg); 618 if (!nfnl) 619 return -ENOMEM; 620 net->nfnl_stash = nfnl; 621 rcu_assign_pointer(net->nfnl, nfnl); 622 return 0; 623 } 624 nfnetlink_net_exit_batch(struct list_head * net_exit_list)625 static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list) 626 { 627 struct net *net; 628 629 list_for_each_entry(net, net_exit_list, exit_list) 630 RCU_INIT_POINTER(net->nfnl, NULL); 631 synchronize_net(); 632 list_for_each_entry(net, net_exit_list, exit_list) 633 netlink_kernel_release(net->nfnl_stash); 634 } 635 636 static struct pernet_operations nfnetlink_net_ops = { 637 .init = nfnetlink_net_init, 638 .exit_batch = nfnetlink_net_exit_batch, 639 }; 640 nfnetlink_init(void)641 static int __init nfnetlink_init(void) 642 { 643 int i; 644 645 for (i = NFNLGRP_NONE + 1; i <= NFNLGRP_MAX; i++) 646 BUG_ON(nfnl_group2type[i] == NFNL_SUBSYS_NONE); 647 648 for (i=0; i<NFNL_SUBSYS_COUNT; i++) 649 mutex_init(&table[i].mutex); 650 651 return register_pernet_subsys(&nfnetlink_net_ops); 652 } 653 nfnetlink_exit(void)654 static void __exit nfnetlink_exit(void) 655 { 656 unregister_pernet_subsys(&nfnetlink_net_ops); 657 } 658 module_init(nfnetlink_init); 659 module_exit(nfnetlink_exit); 660