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 <net/netns/generic.h> 32 #include <linux/netfilter/nfnetlink.h> 33 34 MODULE_LICENSE("GPL"); 35 MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); 36 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER); 37 MODULE_DESCRIPTION("Netfilter messages via netlink socket"); 38 39 #define nfnl_dereference_protected(id) \ 40 rcu_dereference_protected(table[(id)].subsys, \ 41 lockdep_nfnl_is_held((id))) 42 43 #define NFNL_MAX_ATTR_COUNT 32 44 45 static unsigned int nfnetlink_pernet_id __read_mostly; 46 47 struct nfnl_net { 48 struct sock *nfnl; 49 }; 50 51 static struct { 52 struct mutex mutex; 53 const struct nfnetlink_subsystem __rcu *subsys; 54 } table[NFNL_SUBSYS_COUNT]; 55 56 static struct lock_class_key nfnl_lockdep_keys[NFNL_SUBSYS_COUNT]; 57 58 static const char *const nfnl_lockdep_names[NFNL_SUBSYS_COUNT] = { 59 [NFNL_SUBSYS_NONE] = "nfnl_subsys_none", 60 [NFNL_SUBSYS_CTNETLINK] = "nfnl_subsys_ctnetlink", 61 [NFNL_SUBSYS_CTNETLINK_EXP] = "nfnl_subsys_ctnetlink_exp", 62 [NFNL_SUBSYS_QUEUE] = "nfnl_subsys_queue", 63 [NFNL_SUBSYS_ULOG] = "nfnl_subsys_ulog", 64 [NFNL_SUBSYS_OSF] = "nfnl_subsys_osf", 65 [NFNL_SUBSYS_IPSET] = "nfnl_subsys_ipset", 66 [NFNL_SUBSYS_ACCT] = "nfnl_subsys_acct", 67 [NFNL_SUBSYS_CTNETLINK_TIMEOUT] = "nfnl_subsys_cttimeout", 68 [NFNL_SUBSYS_CTHELPER] = "nfnl_subsys_cthelper", 69 [NFNL_SUBSYS_NFTABLES] = "nfnl_subsys_nftables", 70 [NFNL_SUBSYS_NFT_COMPAT] = "nfnl_subsys_nftcompat", 71 }; 72 73 static const int nfnl_group2type[NFNLGRP_MAX+1] = { 74 [NFNLGRP_CONNTRACK_NEW] = NFNL_SUBSYS_CTNETLINK, 75 [NFNLGRP_CONNTRACK_UPDATE] = NFNL_SUBSYS_CTNETLINK, 76 [NFNLGRP_CONNTRACK_DESTROY] = NFNL_SUBSYS_CTNETLINK, 77 [NFNLGRP_CONNTRACK_EXP_NEW] = NFNL_SUBSYS_CTNETLINK_EXP, 78 [NFNLGRP_CONNTRACK_EXP_UPDATE] = NFNL_SUBSYS_CTNETLINK_EXP, 79 [NFNLGRP_CONNTRACK_EXP_DESTROY] = NFNL_SUBSYS_CTNETLINK_EXP, 80 [NFNLGRP_NFTABLES] = NFNL_SUBSYS_NFTABLES, 81 [NFNLGRP_ACCT_QUOTA] = NFNL_SUBSYS_ACCT, 82 [NFNLGRP_NFTRACE] = NFNL_SUBSYS_NFTABLES, 83 }; 84 85 static struct nfnl_net *nfnl_pernet(struct net *net) 86 { 87 return net_generic(net, nfnetlink_pernet_id); 88 } 89 90 void nfnl_lock(__u8 subsys_id) 91 { 92 mutex_lock(&table[subsys_id].mutex); 93 } 94 EXPORT_SYMBOL_GPL(nfnl_lock); 95 96 void nfnl_unlock(__u8 subsys_id) 97 { 98 mutex_unlock(&table[subsys_id].mutex); 99 } 100 EXPORT_SYMBOL_GPL(nfnl_unlock); 101 102 #ifdef CONFIG_PROVE_LOCKING 103 bool lockdep_nfnl_is_held(u8 subsys_id) 104 { 105 return lockdep_is_held(&table[subsys_id].mutex); 106 } 107 EXPORT_SYMBOL_GPL(lockdep_nfnl_is_held); 108 #endif 109 110 int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n) 111 { 112 u8 cb_id; 113 114 /* Sanity-check attr_count size to avoid stack buffer overflow. */ 115 for (cb_id = 0; cb_id < n->cb_count; cb_id++) 116 if (WARN_ON(n->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT)) 117 return -EINVAL; 118 119 nfnl_lock(n->subsys_id); 120 if (table[n->subsys_id].subsys) { 121 nfnl_unlock(n->subsys_id); 122 return -EBUSY; 123 } 124 rcu_assign_pointer(table[n->subsys_id].subsys, n); 125 nfnl_unlock(n->subsys_id); 126 127 return 0; 128 } 129 EXPORT_SYMBOL_GPL(nfnetlink_subsys_register); 130 131 int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n) 132 { 133 nfnl_lock(n->subsys_id); 134 table[n->subsys_id].subsys = NULL; 135 nfnl_unlock(n->subsys_id); 136 synchronize_rcu(); 137 return 0; 138 } 139 EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister); 140 141 static inline const struct nfnetlink_subsystem *nfnetlink_get_subsys(u16 type) 142 { 143 u8 subsys_id = NFNL_SUBSYS_ID(type); 144 145 if (subsys_id >= NFNL_SUBSYS_COUNT) 146 return NULL; 147 148 return rcu_dereference(table[subsys_id].subsys); 149 } 150 151 static inline const struct nfnl_callback * 152 nfnetlink_find_client(u16 type, const struct nfnetlink_subsystem *ss) 153 { 154 u8 cb_id = NFNL_MSG_TYPE(type); 155 156 if (cb_id >= ss->cb_count) 157 return NULL; 158 159 return &ss->cb[cb_id]; 160 } 161 162 int nfnetlink_has_listeners(struct net *net, unsigned int group) 163 { 164 struct nfnl_net *nfnlnet = nfnl_pernet(net); 165 166 return netlink_has_listeners(nfnlnet->nfnl, group); 167 } 168 EXPORT_SYMBOL_GPL(nfnetlink_has_listeners); 169 170 int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid, 171 unsigned int group, int echo, gfp_t flags) 172 { 173 struct nfnl_net *nfnlnet = nfnl_pernet(net); 174 175 return nlmsg_notify(nfnlnet->nfnl, skb, portid, group, echo, flags); 176 } 177 EXPORT_SYMBOL_GPL(nfnetlink_send); 178 179 int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error) 180 { 181 struct nfnl_net *nfnlnet = nfnl_pernet(net); 182 183 return netlink_set_err(nfnlnet->nfnl, portid, group, error); 184 } 185 EXPORT_SYMBOL_GPL(nfnetlink_set_err); 186 187 int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid) 188 { 189 struct nfnl_net *nfnlnet = nfnl_pernet(net); 190 int err; 191 192 err = nlmsg_unicast(nfnlnet->nfnl, skb, portid); 193 if (err == -EAGAIN) 194 err = -ENOBUFS; 195 196 return err; 197 } 198 EXPORT_SYMBOL_GPL(nfnetlink_unicast); 199 200 void nfnetlink_broadcast(struct net *net, struct sk_buff *skb, __u32 portid, 201 __u32 group, gfp_t allocation) 202 { 203 struct nfnl_net *nfnlnet = nfnl_pernet(net); 204 205 netlink_broadcast(nfnlnet->nfnl, skb, portid, group, allocation); 206 } 207 EXPORT_SYMBOL_GPL(nfnetlink_broadcast); 208 209 /* Process one complete nfnetlink message. */ 210 static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, 211 struct netlink_ext_ack *extack) 212 { 213 struct net *net = sock_net(skb->sk); 214 const struct nfnl_callback *nc; 215 const struct nfnetlink_subsystem *ss; 216 int type, err; 217 218 /* All the messages must at least contain nfgenmsg */ 219 if (nlmsg_len(nlh) < sizeof(struct nfgenmsg)) 220 return 0; 221 222 type = nlh->nlmsg_type; 223 replay: 224 rcu_read_lock(); 225 226 ss = nfnetlink_get_subsys(type); 227 if (!ss) { 228 #ifdef CONFIG_MODULES 229 rcu_read_unlock(); 230 request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type)); 231 rcu_read_lock(); 232 ss = nfnetlink_get_subsys(type); 233 if (!ss) 234 #endif 235 { 236 rcu_read_unlock(); 237 return -EINVAL; 238 } 239 } 240 241 nc = nfnetlink_find_client(type, ss); 242 if (!nc) { 243 rcu_read_unlock(); 244 return -EINVAL; 245 } 246 247 { 248 int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); 249 struct nfnl_net *nfnlnet = nfnl_pernet(net); 250 u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); 251 struct nlattr *cda[NFNL_MAX_ATTR_COUNT + 1]; 252 struct nlattr *attr = (void *)nlh + min_len; 253 int attrlen = nlh->nlmsg_len - min_len; 254 __u8 subsys_id = NFNL_SUBSYS_ID(type); 255 256 /* Sanity-check NFNL_MAX_ATTR_COUNT */ 257 if (ss->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT) { 258 rcu_read_unlock(); 259 return -ENOMEM; 260 } 261 262 err = nla_parse_deprecated(cda, ss->cb[cb_id].attr_count, 263 attr, attrlen, 264 ss->cb[cb_id].policy, extack); 265 if (err < 0) { 266 rcu_read_unlock(); 267 return err; 268 } 269 270 if (nc->call_rcu) { 271 err = nc->call_rcu(net, nfnlnet->nfnl, skb, nlh, 272 (const struct nlattr **)cda, 273 extack); 274 rcu_read_unlock(); 275 } else { 276 rcu_read_unlock(); 277 nfnl_lock(subsys_id); 278 if (nfnl_dereference_protected(subsys_id) != ss || 279 nfnetlink_find_client(type, ss) != nc) 280 err = -EAGAIN; 281 else if (nc->call) 282 err = nc->call(net, nfnlnet->nfnl, skb, nlh, 283 (const struct nlattr **)cda, 284 extack); 285 else 286 err = -EINVAL; 287 nfnl_unlock(subsys_id); 288 } 289 if (err == -EAGAIN) 290 goto replay; 291 return err; 292 } 293 } 294 295 struct nfnl_err { 296 struct list_head head; 297 struct nlmsghdr *nlh; 298 int err; 299 struct netlink_ext_ack extack; 300 }; 301 302 static int nfnl_err_add(struct list_head *list, struct nlmsghdr *nlh, int err, 303 const struct netlink_ext_ack *extack) 304 { 305 struct nfnl_err *nfnl_err; 306 307 nfnl_err = kmalloc(sizeof(struct nfnl_err), GFP_KERNEL); 308 if (nfnl_err == NULL) 309 return -ENOMEM; 310 311 nfnl_err->nlh = nlh; 312 nfnl_err->err = err; 313 nfnl_err->extack = *extack; 314 list_add_tail(&nfnl_err->head, list); 315 316 return 0; 317 } 318 319 static void nfnl_err_del(struct nfnl_err *nfnl_err) 320 { 321 list_del(&nfnl_err->head); 322 kfree(nfnl_err); 323 } 324 325 static void nfnl_err_reset(struct list_head *err_list) 326 { 327 struct nfnl_err *nfnl_err, *next; 328 329 list_for_each_entry_safe(nfnl_err, next, err_list, head) 330 nfnl_err_del(nfnl_err); 331 } 332 333 static void nfnl_err_deliver(struct list_head *err_list, struct sk_buff *skb) 334 { 335 struct nfnl_err *nfnl_err, *next; 336 337 list_for_each_entry_safe(nfnl_err, next, err_list, head) { 338 netlink_ack(skb, nfnl_err->nlh, nfnl_err->err, 339 &nfnl_err->extack); 340 nfnl_err_del(nfnl_err); 341 } 342 } 343 344 enum { 345 NFNL_BATCH_FAILURE = (1 << 0), 346 NFNL_BATCH_DONE = (1 << 1), 347 NFNL_BATCH_REPLAY = (1 << 2), 348 }; 349 350 static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh, 351 u16 subsys_id, u32 genid) 352 { 353 struct sk_buff *oskb = skb; 354 struct net *net = sock_net(skb->sk); 355 const struct nfnetlink_subsystem *ss; 356 const struct nfnl_callback *nc; 357 struct netlink_ext_ack extack; 358 LIST_HEAD(err_list); 359 u32 status; 360 int err; 361 362 if (subsys_id >= NFNL_SUBSYS_COUNT) 363 return netlink_ack(skb, nlh, -EINVAL, NULL); 364 replay: 365 status = 0; 366 replay_abort: 367 skb = netlink_skb_clone(oskb, GFP_KERNEL); 368 if (!skb) 369 return netlink_ack(oskb, nlh, -ENOMEM, NULL); 370 371 nfnl_lock(subsys_id); 372 ss = nfnl_dereference_protected(subsys_id); 373 if (!ss) { 374 #ifdef CONFIG_MODULES 375 nfnl_unlock(subsys_id); 376 request_module("nfnetlink-subsys-%d", subsys_id); 377 nfnl_lock(subsys_id); 378 ss = nfnl_dereference_protected(subsys_id); 379 if (!ss) 380 #endif 381 { 382 nfnl_unlock(subsys_id); 383 netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL); 384 return kfree_skb(skb); 385 } 386 } 387 388 if (!ss->valid_genid || !ss->commit || !ss->abort) { 389 nfnl_unlock(subsys_id); 390 netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL); 391 return kfree_skb(skb); 392 } 393 394 if (!try_module_get(ss->owner)) { 395 nfnl_unlock(subsys_id); 396 netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL); 397 return kfree_skb(skb); 398 } 399 400 if (!ss->valid_genid(net, genid)) { 401 module_put(ss->owner); 402 nfnl_unlock(subsys_id); 403 netlink_ack(oskb, nlh, -ERESTART, NULL); 404 return kfree_skb(skb); 405 } 406 407 nfnl_unlock(subsys_id); 408 409 while (skb->len >= nlmsg_total_size(0)) { 410 int msglen, type; 411 412 if (fatal_signal_pending(current)) { 413 nfnl_err_reset(&err_list); 414 err = -EINTR; 415 status = NFNL_BATCH_FAILURE; 416 goto done; 417 } 418 419 memset(&extack, 0, sizeof(extack)); 420 nlh = nlmsg_hdr(skb); 421 err = 0; 422 423 if (nlh->nlmsg_len < NLMSG_HDRLEN || 424 skb->len < nlh->nlmsg_len || 425 nlmsg_len(nlh) < sizeof(struct nfgenmsg)) { 426 nfnl_err_reset(&err_list); 427 status |= NFNL_BATCH_FAILURE; 428 goto done; 429 } 430 431 /* Only requests are handled by the kernel */ 432 if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) { 433 err = -EINVAL; 434 goto ack; 435 } 436 437 type = nlh->nlmsg_type; 438 if (type == NFNL_MSG_BATCH_BEGIN) { 439 /* Malformed: Batch begin twice */ 440 nfnl_err_reset(&err_list); 441 status |= NFNL_BATCH_FAILURE; 442 goto done; 443 } else if (type == NFNL_MSG_BATCH_END) { 444 status |= NFNL_BATCH_DONE; 445 goto done; 446 } else if (type < NLMSG_MIN_TYPE) { 447 err = -EINVAL; 448 goto ack; 449 } 450 451 /* We only accept a batch with messages for the same 452 * subsystem. 453 */ 454 if (NFNL_SUBSYS_ID(type) != subsys_id) { 455 err = -EINVAL; 456 goto ack; 457 } 458 459 nc = nfnetlink_find_client(type, ss); 460 if (!nc) { 461 err = -EINVAL; 462 goto ack; 463 } 464 465 { 466 int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); 467 u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); 468 struct nlattr *cda[NFNL_MAX_ATTR_COUNT + 1]; 469 struct nlattr *attr = (void *)nlh + min_len; 470 int attrlen = nlh->nlmsg_len - min_len; 471 472 /* Sanity-check NFTA_MAX_ATTR */ 473 if (ss->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT) { 474 err = -ENOMEM; 475 goto ack; 476 } 477 478 err = nla_parse_deprecated(cda, 479 ss->cb[cb_id].attr_count, 480 attr, attrlen, 481 ss->cb[cb_id].policy, NULL); 482 if (err < 0) 483 goto ack; 484 485 if (nc->call_batch) { 486 struct nfnl_net *nfnlnet = nfnl_pernet(net); 487 488 err = nc->call_batch(net, nfnlnet->nfnl, skb, nlh, 489 (const struct nlattr **)cda, 490 &extack); 491 } 492 493 /* The lock was released to autoload some module, we 494 * have to abort and start from scratch using the 495 * original skb. 496 */ 497 if (err == -EAGAIN) { 498 status |= NFNL_BATCH_REPLAY; 499 goto done; 500 } 501 } 502 ack: 503 if (nlh->nlmsg_flags & NLM_F_ACK || err) { 504 /* Errors are delivered once the full batch has been 505 * processed, this avoids that the same error is 506 * reported several times when replaying the batch. 507 */ 508 if (nfnl_err_add(&err_list, nlh, err, &extack) < 0) { 509 /* We failed to enqueue an error, reset the 510 * list of errors and send OOM to userspace 511 * pointing to the batch header. 512 */ 513 nfnl_err_reset(&err_list); 514 netlink_ack(oskb, nlmsg_hdr(oskb), -ENOMEM, 515 NULL); 516 status |= NFNL_BATCH_FAILURE; 517 goto done; 518 } 519 /* We don't stop processing the batch on errors, thus, 520 * userspace gets all the errors that the batch 521 * triggers. 522 */ 523 if (err) 524 status |= NFNL_BATCH_FAILURE; 525 } 526 527 msglen = NLMSG_ALIGN(nlh->nlmsg_len); 528 if (msglen > skb->len) 529 msglen = skb->len; 530 skb_pull(skb, msglen); 531 } 532 done: 533 if (status & NFNL_BATCH_REPLAY) { 534 ss->abort(net, oskb, NFNL_ABORT_AUTOLOAD); 535 nfnl_err_reset(&err_list); 536 kfree_skb(skb); 537 module_put(ss->owner); 538 goto replay; 539 } else if (status == NFNL_BATCH_DONE) { 540 err = ss->commit(net, oskb); 541 if (err == -EAGAIN) { 542 status |= NFNL_BATCH_REPLAY; 543 goto done; 544 } else if (err) { 545 ss->abort(net, oskb, NFNL_ABORT_NONE); 546 netlink_ack(oskb, nlmsg_hdr(oskb), err, NULL); 547 } 548 } else { 549 enum nfnl_abort_action abort_action; 550 551 if (status & NFNL_BATCH_FAILURE) 552 abort_action = NFNL_ABORT_NONE; 553 else 554 abort_action = NFNL_ABORT_VALIDATE; 555 556 err = ss->abort(net, oskb, abort_action); 557 if (err == -EAGAIN) { 558 nfnl_err_reset(&err_list); 559 kfree_skb(skb); 560 module_put(ss->owner); 561 status |= NFNL_BATCH_FAILURE; 562 goto replay_abort; 563 } 564 } 565 if (ss->cleanup) 566 ss->cleanup(net); 567 568 nfnl_err_deliver(&err_list, oskb); 569 kfree_skb(skb); 570 module_put(ss->owner); 571 } 572 573 static const struct nla_policy nfnl_batch_policy[NFNL_BATCH_MAX + 1] = { 574 [NFNL_BATCH_GENID] = { .type = NLA_U32 }, 575 }; 576 577 static void nfnetlink_rcv_skb_batch(struct sk_buff *skb, struct nlmsghdr *nlh) 578 { 579 int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); 580 struct nlattr *attr = (void *)nlh + min_len; 581 struct nlattr *cda[NFNL_BATCH_MAX + 1]; 582 int attrlen = nlh->nlmsg_len - min_len; 583 struct nfgenmsg *nfgenmsg; 584 int msglen, err; 585 u32 gen_id = 0; 586 u16 res_id; 587 588 msglen = NLMSG_ALIGN(nlh->nlmsg_len); 589 if (msglen > skb->len) 590 msglen = skb->len; 591 592 if (skb->len < NLMSG_HDRLEN + sizeof(struct nfgenmsg)) 593 return; 594 595 err = nla_parse_deprecated(cda, NFNL_BATCH_MAX, attr, attrlen, 596 nfnl_batch_policy, NULL); 597 if (err < 0) { 598 netlink_ack(skb, nlh, err, NULL); 599 return; 600 } 601 if (cda[NFNL_BATCH_GENID]) 602 gen_id = ntohl(nla_get_be32(cda[NFNL_BATCH_GENID])); 603 604 nfgenmsg = nlmsg_data(nlh); 605 skb_pull(skb, msglen); 606 /* Work around old nft using host byte order */ 607 if (nfgenmsg->res_id == NFNL_SUBSYS_NFTABLES) 608 res_id = NFNL_SUBSYS_NFTABLES; 609 else 610 res_id = ntohs(nfgenmsg->res_id); 611 612 nfnetlink_rcv_batch(skb, nlh, res_id, gen_id); 613 } 614 615 static void nfnetlink_rcv(struct sk_buff *skb) 616 { 617 struct nlmsghdr *nlh = nlmsg_hdr(skb); 618 619 if (skb->len < NLMSG_HDRLEN || 620 nlh->nlmsg_len < NLMSG_HDRLEN || 621 skb->len < nlh->nlmsg_len) 622 return; 623 624 if (!netlink_net_capable(skb, CAP_NET_ADMIN)) { 625 netlink_ack(skb, nlh, -EPERM, NULL); 626 return; 627 } 628 629 if (nlh->nlmsg_type == NFNL_MSG_BATCH_BEGIN) 630 nfnetlink_rcv_skb_batch(skb, nlh); 631 else 632 netlink_rcv_skb(skb, nfnetlink_rcv_msg); 633 } 634 635 #ifdef CONFIG_MODULES 636 static int nfnetlink_bind(struct net *net, int group) 637 { 638 const struct nfnetlink_subsystem *ss; 639 int type; 640 641 if (group <= NFNLGRP_NONE || group > NFNLGRP_MAX) 642 return 0; 643 644 type = nfnl_group2type[group]; 645 646 rcu_read_lock(); 647 ss = nfnetlink_get_subsys(type << 8); 648 rcu_read_unlock(); 649 if (!ss) 650 request_module_nowait("nfnetlink-subsys-%d", type); 651 return 0; 652 } 653 #endif 654 655 static int __net_init nfnetlink_net_init(struct net *net) 656 { 657 struct nfnl_net *nfnlnet = nfnl_pernet(net); 658 struct netlink_kernel_cfg cfg = { 659 .groups = NFNLGRP_MAX, 660 .input = nfnetlink_rcv, 661 #ifdef CONFIG_MODULES 662 .bind = nfnetlink_bind, 663 #endif 664 }; 665 666 nfnlnet->nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, &cfg); 667 if (!nfnlnet->nfnl) 668 return -ENOMEM; 669 return 0; 670 } 671 672 static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list) 673 { 674 struct nfnl_net *nfnlnet; 675 struct net *net; 676 677 list_for_each_entry(net, net_exit_list, exit_list) { 678 nfnlnet = nfnl_pernet(net); 679 680 netlink_kernel_release(nfnlnet->nfnl); 681 } 682 } 683 684 static struct pernet_operations nfnetlink_net_ops = { 685 .init = nfnetlink_net_init, 686 .exit_batch = nfnetlink_net_exit_batch, 687 .id = &nfnetlink_pernet_id, 688 .size = sizeof(struct nfnl_net), 689 }; 690 691 static int __init nfnetlink_init(void) 692 { 693 int i; 694 695 for (i = NFNLGRP_NONE + 1; i <= NFNLGRP_MAX; i++) 696 BUG_ON(nfnl_group2type[i] == NFNL_SUBSYS_NONE); 697 698 for (i=0; i<NFNL_SUBSYS_COUNT; i++) 699 __mutex_init(&table[i].mutex, nfnl_lockdep_names[i], &nfnl_lockdep_keys[i]); 700 701 return register_pernet_subsys(&nfnetlink_net_ops); 702 } 703 704 static void __exit nfnetlink_exit(void) 705 { 706 unregister_pernet_subsys(&nfnetlink_net_ops); 707 } 708 module_init(nfnetlink_init); 709 module_exit(nfnetlink_exit); 710