1 /* 2 * NETLINK Kernel-user communication protocol. 3 * 4 * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> 5 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 * 12 * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith 13 * added netlink_proto_exit 14 * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> 15 * use nlk_sk, as sk->protinfo is on a diet 8) 16 * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> 17 * - inc module use count of module that owns 18 * the kernel socket in case userspace opens 19 * socket of same protocol 20 * - remove all module support, since netlink is 21 * mandatory if CONFIG_NET=y these days 22 */ 23 24 #include <linux/module.h> 25 26 #include <linux/capability.h> 27 #include <linux/kernel.h> 28 #include <linux/init.h> 29 #include <linux/signal.h> 30 #include <linux/sched.h> 31 #include <linux/errno.h> 32 #include <linux/string.h> 33 #include <linux/stat.h> 34 #include <linux/socket.h> 35 #include <linux/un.h> 36 #include <linux/fcntl.h> 37 #include <linux/termios.h> 38 #include <linux/sockios.h> 39 #include <linux/net.h> 40 #include <linux/fs.h> 41 #include <linux/slab.h> 42 #include <asm/uaccess.h> 43 #include <linux/skbuff.h> 44 #include <linux/netdevice.h> 45 #include <linux/rtnetlink.h> 46 #include <linux/proc_fs.h> 47 #include <linux/seq_file.h> 48 #include <linux/notifier.h> 49 #include <linux/security.h> 50 #include <linux/jhash.h> 51 #include <linux/jiffies.h> 52 #include <linux/random.h> 53 #include <linux/bitops.h> 54 #include <linux/mm.h> 55 #include <linux/types.h> 56 #include <linux/audit.h> 57 #include <linux/mutex.h> 58 59 #include <net/net_namespace.h> 60 #include <net/sock.h> 61 #include <net/scm.h> 62 #include <net/netlink.h> 63 64 #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) 65 #define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long)) 66 67 struct netlink_sock { 68 /* struct sock has to be the first member of netlink_sock */ 69 struct sock sk; 70 u32 pid; 71 u32 dst_pid; 72 u32 dst_group; 73 u32 flags; 74 u32 subscriptions; 75 u32 ngroups; 76 unsigned long *groups; 77 unsigned long state; 78 wait_queue_head_t wait; 79 struct netlink_callback *cb; 80 struct mutex *cb_mutex; 81 struct mutex cb_def_mutex; 82 void (*netlink_rcv)(struct sk_buff *skb); 83 void (*netlink_bind)(int group); 84 struct module *module; 85 }; 86 87 struct listeners { 88 struct rcu_head rcu; 89 unsigned long masks[0]; 90 }; 91 92 #define NETLINK_KERNEL_SOCKET 0x1 93 #define NETLINK_RECV_PKTINFO 0x2 94 #define NETLINK_BROADCAST_SEND_ERROR 0x4 95 #define NETLINK_RECV_NO_ENOBUFS 0x8 96 97 static inline struct netlink_sock *nlk_sk(struct sock *sk) 98 { 99 return container_of(sk, struct netlink_sock, sk); 100 } 101 102 static inline int netlink_is_kernel(struct sock *sk) 103 { 104 return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET; 105 } 106 107 struct nl_pid_hash { 108 struct hlist_head *table; 109 unsigned long rehash_time; 110 111 unsigned int mask; 112 unsigned int shift; 113 114 unsigned int entries; 115 unsigned int max_shift; 116 117 u32 rnd; 118 }; 119 120 struct netlink_table { 121 struct nl_pid_hash hash; 122 struct hlist_head mc_list; 123 struct listeners __rcu *listeners; 124 unsigned int nl_nonroot; 125 unsigned int groups; 126 struct mutex *cb_mutex; 127 struct module *module; 128 void (*bind)(int group); 129 int registered; 130 }; 131 132 static struct netlink_table *nl_table; 133 134 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); 135 136 static int netlink_dump(struct sock *sk); 137 138 static DEFINE_RWLOCK(nl_table_lock); 139 static atomic_t nl_table_users = ATOMIC_INIT(0); 140 141 static ATOMIC_NOTIFIER_HEAD(netlink_chain); 142 143 static inline u32 netlink_group_mask(u32 group) 144 { 145 return group ? 1 << (group - 1) : 0; 146 } 147 148 static inline struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) 149 { 150 return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask]; 151 } 152 153 static void netlink_destroy_callback(struct netlink_callback *cb) 154 { 155 kfree_skb(cb->skb); 156 kfree(cb); 157 } 158 159 static void netlink_consume_callback(struct netlink_callback *cb) 160 { 161 consume_skb(cb->skb); 162 kfree(cb); 163 } 164 165 static void netlink_sock_destruct(struct sock *sk) 166 { 167 struct netlink_sock *nlk = nlk_sk(sk); 168 169 if (nlk->cb) { 170 if (nlk->cb->done) 171 nlk->cb->done(nlk->cb); 172 netlink_destroy_callback(nlk->cb); 173 } 174 175 skb_queue_purge(&sk->sk_receive_queue); 176 177 if (!sock_flag(sk, SOCK_DEAD)) { 178 printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); 179 return; 180 } 181 182 WARN_ON(atomic_read(&sk->sk_rmem_alloc)); 183 WARN_ON(atomic_read(&sk->sk_wmem_alloc)); 184 WARN_ON(nlk_sk(sk)->groups); 185 } 186 187 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on 188 * SMP. Look, when several writers sleep and reader wakes them up, all but one 189 * immediately hit write lock and grab all the cpus. Exclusive sleep solves 190 * this, _but_ remember, it adds useless work on UP machines. 191 */ 192 193 void netlink_table_grab(void) 194 __acquires(nl_table_lock) 195 { 196 might_sleep(); 197 198 write_lock_irq(&nl_table_lock); 199 200 if (atomic_read(&nl_table_users)) { 201 DECLARE_WAITQUEUE(wait, current); 202 203 add_wait_queue_exclusive(&nl_table_wait, &wait); 204 for (;;) { 205 set_current_state(TASK_UNINTERRUPTIBLE); 206 if (atomic_read(&nl_table_users) == 0) 207 break; 208 write_unlock_irq(&nl_table_lock); 209 schedule(); 210 write_lock_irq(&nl_table_lock); 211 } 212 213 __set_current_state(TASK_RUNNING); 214 remove_wait_queue(&nl_table_wait, &wait); 215 } 216 } 217 218 void netlink_table_ungrab(void) 219 __releases(nl_table_lock) 220 { 221 write_unlock_irq(&nl_table_lock); 222 wake_up(&nl_table_wait); 223 } 224 225 static inline void 226 netlink_lock_table(void) 227 { 228 /* read_lock() synchronizes us to netlink_table_grab */ 229 230 read_lock(&nl_table_lock); 231 atomic_inc(&nl_table_users); 232 read_unlock(&nl_table_lock); 233 } 234 235 static inline void 236 netlink_unlock_table(void) 237 { 238 if (atomic_dec_and_test(&nl_table_users)) 239 wake_up(&nl_table_wait); 240 } 241 242 static struct sock *netlink_lookup(struct net *net, int protocol, u32 pid) 243 { 244 struct nl_pid_hash *hash = &nl_table[protocol].hash; 245 struct hlist_head *head; 246 struct sock *sk; 247 struct hlist_node *node; 248 249 read_lock(&nl_table_lock); 250 head = nl_pid_hashfn(hash, pid); 251 sk_for_each(sk, node, head) { 252 if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) { 253 sock_hold(sk); 254 goto found; 255 } 256 } 257 sk = NULL; 258 found: 259 read_unlock(&nl_table_lock); 260 return sk; 261 } 262 263 static struct hlist_head *nl_pid_hash_zalloc(size_t size) 264 { 265 if (size <= PAGE_SIZE) 266 return kzalloc(size, GFP_ATOMIC); 267 else 268 return (struct hlist_head *) 269 __get_free_pages(GFP_ATOMIC | __GFP_ZERO, 270 get_order(size)); 271 } 272 273 static void nl_pid_hash_free(struct hlist_head *table, size_t size) 274 { 275 if (size <= PAGE_SIZE) 276 kfree(table); 277 else 278 free_pages((unsigned long)table, get_order(size)); 279 } 280 281 static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) 282 { 283 unsigned int omask, mask, shift; 284 size_t osize, size; 285 struct hlist_head *otable, *table; 286 int i; 287 288 omask = mask = hash->mask; 289 osize = size = (mask + 1) * sizeof(*table); 290 shift = hash->shift; 291 292 if (grow) { 293 if (++shift > hash->max_shift) 294 return 0; 295 mask = mask * 2 + 1; 296 size *= 2; 297 } 298 299 table = nl_pid_hash_zalloc(size); 300 if (!table) 301 return 0; 302 303 otable = hash->table; 304 hash->table = table; 305 hash->mask = mask; 306 hash->shift = shift; 307 get_random_bytes(&hash->rnd, sizeof(hash->rnd)); 308 309 for (i = 0; i <= omask; i++) { 310 struct sock *sk; 311 struct hlist_node *node, *tmp; 312 313 sk_for_each_safe(sk, node, tmp, &otable[i]) 314 __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); 315 } 316 317 nl_pid_hash_free(otable, osize); 318 hash->rehash_time = jiffies + 10 * 60 * HZ; 319 return 1; 320 } 321 322 static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) 323 { 324 int avg = hash->entries >> hash->shift; 325 326 if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) 327 return 1; 328 329 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { 330 nl_pid_hash_rehash(hash, 0); 331 return 1; 332 } 333 334 return 0; 335 } 336 337 static const struct proto_ops netlink_ops; 338 339 static void 340 netlink_update_listeners(struct sock *sk) 341 { 342 struct netlink_table *tbl = &nl_table[sk->sk_protocol]; 343 struct hlist_node *node; 344 unsigned long mask; 345 unsigned int i; 346 347 for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { 348 mask = 0; 349 sk_for_each_bound(sk, node, &tbl->mc_list) { 350 if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) 351 mask |= nlk_sk(sk)->groups[i]; 352 } 353 tbl->listeners->masks[i] = mask; 354 } 355 /* this function is only called with the netlink table "grabbed", which 356 * makes sure updates are visible before bind or setsockopt return. */ 357 } 358 359 static int netlink_insert(struct sock *sk, struct net *net, u32 pid) 360 { 361 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; 362 struct hlist_head *head; 363 int err = -EADDRINUSE; 364 struct sock *osk; 365 struct hlist_node *node; 366 int len; 367 368 netlink_table_grab(); 369 head = nl_pid_hashfn(hash, pid); 370 len = 0; 371 sk_for_each(osk, node, head) { 372 if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid)) 373 break; 374 len++; 375 } 376 if (node) 377 goto err; 378 379 err = -EBUSY; 380 if (nlk_sk(sk)->pid) 381 goto err; 382 383 err = -ENOMEM; 384 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) 385 goto err; 386 387 if (len && nl_pid_hash_dilute(hash, len)) 388 head = nl_pid_hashfn(hash, pid); 389 hash->entries++; 390 nlk_sk(sk)->pid = pid; 391 sk_add_node(sk, head); 392 err = 0; 393 394 err: 395 netlink_table_ungrab(); 396 return err; 397 } 398 399 static void netlink_remove(struct sock *sk) 400 { 401 netlink_table_grab(); 402 if (sk_del_node_init(sk)) 403 nl_table[sk->sk_protocol].hash.entries--; 404 if (nlk_sk(sk)->subscriptions) 405 __sk_del_bind_node(sk); 406 netlink_table_ungrab(); 407 } 408 409 static struct proto netlink_proto = { 410 .name = "NETLINK", 411 .owner = THIS_MODULE, 412 .obj_size = sizeof(struct netlink_sock), 413 }; 414 415 static int __netlink_create(struct net *net, struct socket *sock, 416 struct mutex *cb_mutex, int protocol) 417 { 418 struct sock *sk; 419 struct netlink_sock *nlk; 420 421 sock->ops = &netlink_ops; 422 423 sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto); 424 if (!sk) 425 return -ENOMEM; 426 427 sock_init_data(sock, sk); 428 429 nlk = nlk_sk(sk); 430 if (cb_mutex) { 431 nlk->cb_mutex = cb_mutex; 432 } else { 433 nlk->cb_mutex = &nlk->cb_def_mutex; 434 mutex_init(nlk->cb_mutex); 435 } 436 init_waitqueue_head(&nlk->wait); 437 438 sk->sk_destruct = netlink_sock_destruct; 439 sk->sk_protocol = protocol; 440 return 0; 441 } 442 443 static int netlink_create(struct net *net, struct socket *sock, int protocol, 444 int kern) 445 { 446 struct module *module = NULL; 447 struct mutex *cb_mutex; 448 struct netlink_sock *nlk; 449 void (*bind)(int group); 450 int err = 0; 451 452 sock->state = SS_UNCONNECTED; 453 454 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) 455 return -ESOCKTNOSUPPORT; 456 457 if (protocol < 0 || protocol >= MAX_LINKS) 458 return -EPROTONOSUPPORT; 459 460 netlink_lock_table(); 461 #ifdef CONFIG_MODULES 462 if (!nl_table[protocol].registered) { 463 netlink_unlock_table(); 464 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); 465 netlink_lock_table(); 466 } 467 #endif 468 if (nl_table[protocol].registered && 469 try_module_get(nl_table[protocol].module)) 470 module = nl_table[protocol].module; 471 else 472 err = -EPROTONOSUPPORT; 473 cb_mutex = nl_table[protocol].cb_mutex; 474 bind = nl_table[protocol].bind; 475 netlink_unlock_table(); 476 477 if (err < 0) 478 goto out; 479 480 err = __netlink_create(net, sock, cb_mutex, protocol); 481 if (err < 0) 482 goto out_module; 483 484 local_bh_disable(); 485 sock_prot_inuse_add(net, &netlink_proto, 1); 486 local_bh_enable(); 487 488 nlk = nlk_sk(sock->sk); 489 nlk->module = module; 490 nlk->netlink_bind = bind; 491 out: 492 return err; 493 494 out_module: 495 module_put(module); 496 goto out; 497 } 498 499 static int netlink_release(struct socket *sock) 500 { 501 struct sock *sk = sock->sk; 502 struct netlink_sock *nlk; 503 504 if (!sk) 505 return 0; 506 507 netlink_remove(sk); 508 sock_orphan(sk); 509 nlk = nlk_sk(sk); 510 511 /* 512 * OK. Socket is unlinked, any packets that arrive now 513 * will be purged. 514 */ 515 516 sock->sk = NULL; 517 wake_up_interruptible_all(&nlk->wait); 518 519 skb_queue_purge(&sk->sk_write_queue); 520 521 if (nlk->pid) { 522 struct netlink_notify n = { 523 .net = sock_net(sk), 524 .protocol = sk->sk_protocol, 525 .pid = nlk->pid, 526 }; 527 atomic_notifier_call_chain(&netlink_chain, 528 NETLINK_URELEASE, &n); 529 } 530 531 module_put(nlk->module); 532 533 netlink_table_grab(); 534 if (netlink_is_kernel(sk)) { 535 BUG_ON(nl_table[sk->sk_protocol].registered == 0); 536 if (--nl_table[sk->sk_protocol].registered == 0) { 537 kfree(nl_table[sk->sk_protocol].listeners); 538 nl_table[sk->sk_protocol].module = NULL; 539 nl_table[sk->sk_protocol].registered = 0; 540 } 541 } else if (nlk->subscriptions) { 542 netlink_update_listeners(sk); 543 } 544 netlink_table_ungrab(); 545 546 kfree(nlk->groups); 547 nlk->groups = NULL; 548 549 local_bh_disable(); 550 sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); 551 local_bh_enable(); 552 sock_put(sk); 553 return 0; 554 } 555 556 static int netlink_autobind(struct socket *sock) 557 { 558 struct sock *sk = sock->sk; 559 struct net *net = sock_net(sk); 560 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; 561 struct hlist_head *head; 562 struct sock *osk; 563 struct hlist_node *node; 564 s32 pid = task_tgid_vnr(current); 565 int err; 566 static s32 rover = -4097; 567 568 retry: 569 cond_resched(); 570 netlink_table_grab(); 571 head = nl_pid_hashfn(hash, pid); 572 sk_for_each(osk, node, head) { 573 if (!net_eq(sock_net(osk), net)) 574 continue; 575 if (nlk_sk(osk)->pid == pid) { 576 /* Bind collision, search negative pid values. */ 577 pid = rover--; 578 if (rover > -4097) 579 rover = -4097; 580 netlink_table_ungrab(); 581 goto retry; 582 } 583 } 584 netlink_table_ungrab(); 585 586 err = netlink_insert(sk, net, pid); 587 if (err == -EADDRINUSE) 588 goto retry; 589 590 /* If 2 threads race to autobind, that is fine. */ 591 if (err == -EBUSY) 592 err = 0; 593 594 return err; 595 } 596 597 static inline int netlink_capable(const struct socket *sock, unsigned int flag) 598 { 599 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || 600 capable(CAP_NET_ADMIN); 601 } 602 603 static void 604 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) 605 { 606 struct netlink_sock *nlk = nlk_sk(sk); 607 608 if (nlk->subscriptions && !subscriptions) 609 __sk_del_bind_node(sk); 610 else if (!nlk->subscriptions && subscriptions) 611 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); 612 nlk->subscriptions = subscriptions; 613 } 614 615 static int netlink_realloc_groups(struct sock *sk) 616 { 617 struct netlink_sock *nlk = nlk_sk(sk); 618 unsigned int groups; 619 unsigned long *new_groups; 620 int err = 0; 621 622 netlink_table_grab(); 623 624 groups = nl_table[sk->sk_protocol].groups; 625 if (!nl_table[sk->sk_protocol].registered) { 626 err = -ENOENT; 627 goto out_unlock; 628 } 629 630 if (nlk->ngroups >= groups) 631 goto out_unlock; 632 633 new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); 634 if (new_groups == NULL) { 635 err = -ENOMEM; 636 goto out_unlock; 637 } 638 memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, 639 NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); 640 641 nlk->groups = new_groups; 642 nlk->ngroups = groups; 643 out_unlock: 644 netlink_table_ungrab(); 645 return err; 646 } 647 648 static int netlink_bind(struct socket *sock, struct sockaddr *addr, 649 int addr_len) 650 { 651 struct sock *sk = sock->sk; 652 struct net *net = sock_net(sk); 653 struct netlink_sock *nlk = nlk_sk(sk); 654 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; 655 int err; 656 657 if (nladdr->nl_family != AF_NETLINK) 658 return -EINVAL; 659 660 /* Only superuser is allowed to listen multicasts */ 661 if (nladdr->nl_groups) { 662 if (!netlink_capable(sock, NL_NONROOT_RECV)) 663 return -EPERM; 664 err = netlink_realloc_groups(sk); 665 if (err) 666 return err; 667 } 668 669 if (nlk->pid) { 670 if (nladdr->nl_pid != nlk->pid) 671 return -EINVAL; 672 } else { 673 err = nladdr->nl_pid ? 674 netlink_insert(sk, net, nladdr->nl_pid) : 675 netlink_autobind(sock); 676 if (err) 677 return err; 678 } 679 680 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) 681 return 0; 682 683 netlink_table_grab(); 684 netlink_update_subscriptions(sk, nlk->subscriptions + 685 hweight32(nladdr->nl_groups) - 686 hweight32(nlk->groups[0])); 687 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; 688 netlink_update_listeners(sk); 689 netlink_table_ungrab(); 690 691 if (nlk->netlink_bind && nlk->groups[0]) { 692 int i; 693 694 for (i=0; i<nlk->ngroups; i++) { 695 if (test_bit(i, nlk->groups)) 696 nlk->netlink_bind(i); 697 } 698 } 699 700 return 0; 701 } 702 703 static int netlink_connect(struct socket *sock, struct sockaddr *addr, 704 int alen, int flags) 705 { 706 int err = 0; 707 struct sock *sk = sock->sk; 708 struct netlink_sock *nlk = nlk_sk(sk); 709 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; 710 711 if (alen < sizeof(addr->sa_family)) 712 return -EINVAL; 713 714 if (addr->sa_family == AF_UNSPEC) { 715 sk->sk_state = NETLINK_UNCONNECTED; 716 nlk->dst_pid = 0; 717 nlk->dst_group = 0; 718 return 0; 719 } 720 if (addr->sa_family != AF_NETLINK) 721 return -EINVAL; 722 723 /* Only superuser is allowed to send multicasts */ 724 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) 725 return -EPERM; 726 727 if (!nlk->pid) 728 err = netlink_autobind(sock); 729 730 if (err == 0) { 731 sk->sk_state = NETLINK_CONNECTED; 732 nlk->dst_pid = nladdr->nl_pid; 733 nlk->dst_group = ffs(nladdr->nl_groups); 734 } 735 736 return err; 737 } 738 739 static int netlink_getname(struct socket *sock, struct sockaddr *addr, 740 int *addr_len, int peer) 741 { 742 struct sock *sk = sock->sk; 743 struct netlink_sock *nlk = nlk_sk(sk); 744 DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); 745 746 nladdr->nl_family = AF_NETLINK; 747 nladdr->nl_pad = 0; 748 *addr_len = sizeof(*nladdr); 749 750 if (peer) { 751 nladdr->nl_pid = nlk->dst_pid; 752 nladdr->nl_groups = netlink_group_mask(nlk->dst_group); 753 } else { 754 nladdr->nl_pid = nlk->pid; 755 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; 756 } 757 return 0; 758 } 759 760 static void netlink_overrun(struct sock *sk) 761 { 762 struct netlink_sock *nlk = nlk_sk(sk); 763 764 if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) { 765 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { 766 sk->sk_err = ENOBUFS; 767 sk->sk_error_report(sk); 768 } 769 } 770 atomic_inc(&sk->sk_drops); 771 } 772 773 static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) 774 { 775 struct sock *sock; 776 struct netlink_sock *nlk; 777 778 sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid); 779 if (!sock) 780 return ERR_PTR(-ECONNREFUSED); 781 782 /* Don't bother queuing skb if kernel socket has no input function */ 783 nlk = nlk_sk(sock); 784 if (sock->sk_state == NETLINK_CONNECTED && 785 nlk->dst_pid != nlk_sk(ssk)->pid) { 786 sock_put(sock); 787 return ERR_PTR(-ECONNREFUSED); 788 } 789 return sock; 790 } 791 792 struct sock *netlink_getsockbyfilp(struct file *filp) 793 { 794 struct inode *inode = filp->f_path.dentry->d_inode; 795 struct sock *sock; 796 797 if (!S_ISSOCK(inode->i_mode)) 798 return ERR_PTR(-ENOTSOCK); 799 800 sock = SOCKET_I(inode)->sk; 801 if (sock->sk_family != AF_NETLINK) 802 return ERR_PTR(-EINVAL); 803 804 sock_hold(sock); 805 return sock; 806 } 807 808 /* 809 * Attach a skb to a netlink socket. 810 * The caller must hold a reference to the destination socket. On error, the 811 * reference is dropped. The skb is not send to the destination, just all 812 * all error checks are performed and memory in the queue is reserved. 813 * Return values: 814 * < 0: error. skb freed, reference to sock dropped. 815 * 0: continue 816 * 1: repeat lookup - reference dropped while waiting for socket memory. 817 */ 818 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, 819 long *timeo, struct sock *ssk) 820 { 821 struct netlink_sock *nlk; 822 823 nlk = nlk_sk(sk); 824 825 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || 826 test_bit(0, &nlk->state)) { 827 DECLARE_WAITQUEUE(wait, current); 828 if (!*timeo) { 829 if (!ssk || netlink_is_kernel(ssk)) 830 netlink_overrun(sk); 831 sock_put(sk); 832 kfree_skb(skb); 833 return -EAGAIN; 834 } 835 836 __set_current_state(TASK_INTERRUPTIBLE); 837 add_wait_queue(&nlk->wait, &wait); 838 839 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || 840 test_bit(0, &nlk->state)) && 841 !sock_flag(sk, SOCK_DEAD)) 842 *timeo = schedule_timeout(*timeo); 843 844 __set_current_state(TASK_RUNNING); 845 remove_wait_queue(&nlk->wait, &wait); 846 sock_put(sk); 847 848 if (signal_pending(current)) { 849 kfree_skb(skb); 850 return sock_intr_errno(*timeo); 851 } 852 return 1; 853 } 854 skb_set_owner_r(skb, sk); 855 return 0; 856 } 857 858 static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) 859 { 860 int len = skb->len; 861 862 skb_queue_tail(&sk->sk_receive_queue, skb); 863 sk->sk_data_ready(sk, len); 864 return len; 865 } 866 867 int netlink_sendskb(struct sock *sk, struct sk_buff *skb) 868 { 869 int len = __netlink_sendskb(sk, skb); 870 871 sock_put(sk); 872 return len; 873 } 874 875 void netlink_detachskb(struct sock *sk, struct sk_buff *skb) 876 { 877 kfree_skb(skb); 878 sock_put(sk); 879 } 880 881 static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) 882 { 883 int delta; 884 885 skb_orphan(skb); 886 887 delta = skb->end - skb->tail; 888 if (delta * 2 < skb->truesize) 889 return skb; 890 891 if (skb_shared(skb)) { 892 struct sk_buff *nskb = skb_clone(skb, allocation); 893 if (!nskb) 894 return skb; 895 consume_skb(skb); 896 skb = nskb; 897 } 898 899 if (!pskb_expand_head(skb, 0, -delta, allocation)) 900 skb->truesize -= delta; 901 902 return skb; 903 } 904 905 static void netlink_rcv_wake(struct sock *sk) 906 { 907 struct netlink_sock *nlk = nlk_sk(sk); 908 909 if (skb_queue_empty(&sk->sk_receive_queue)) 910 clear_bit(0, &nlk->state); 911 if (!test_bit(0, &nlk->state)) 912 wake_up_interruptible(&nlk->wait); 913 } 914 915 static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb) 916 { 917 int ret; 918 struct netlink_sock *nlk = nlk_sk(sk); 919 920 ret = -ECONNREFUSED; 921 if (nlk->netlink_rcv != NULL) { 922 ret = skb->len; 923 skb_set_owner_r(skb, sk); 924 nlk->netlink_rcv(skb); 925 consume_skb(skb); 926 } else { 927 kfree_skb(skb); 928 } 929 sock_put(sk); 930 return ret; 931 } 932 933 int netlink_unicast(struct sock *ssk, struct sk_buff *skb, 934 u32 pid, int nonblock) 935 { 936 struct sock *sk; 937 int err; 938 long timeo; 939 940 skb = netlink_trim(skb, gfp_any()); 941 942 timeo = sock_sndtimeo(ssk, nonblock); 943 retry: 944 sk = netlink_getsockbypid(ssk, pid); 945 if (IS_ERR(sk)) { 946 kfree_skb(skb); 947 return PTR_ERR(sk); 948 } 949 if (netlink_is_kernel(sk)) 950 return netlink_unicast_kernel(sk, skb); 951 952 if (sk_filter(sk, skb)) { 953 err = skb->len; 954 kfree_skb(skb); 955 sock_put(sk); 956 return err; 957 } 958 959 err = netlink_attachskb(sk, skb, &timeo, ssk); 960 if (err == 1) 961 goto retry; 962 if (err) 963 return err; 964 965 return netlink_sendskb(sk, skb); 966 } 967 EXPORT_SYMBOL(netlink_unicast); 968 969 int netlink_has_listeners(struct sock *sk, unsigned int group) 970 { 971 int res = 0; 972 struct listeners *listeners; 973 974 BUG_ON(!netlink_is_kernel(sk)); 975 976 rcu_read_lock(); 977 listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); 978 979 if (group - 1 < nl_table[sk->sk_protocol].groups) 980 res = test_bit(group - 1, listeners->masks); 981 982 rcu_read_unlock(); 983 984 return res; 985 } 986 EXPORT_SYMBOL_GPL(netlink_has_listeners); 987 988 static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) 989 { 990 struct netlink_sock *nlk = nlk_sk(sk); 991 992 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && 993 !test_bit(0, &nlk->state)) { 994 skb_set_owner_r(skb, sk); 995 __netlink_sendskb(sk, skb); 996 return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); 997 } 998 return -1; 999 } 1000 1001 struct netlink_broadcast_data { 1002 struct sock *exclude_sk; 1003 struct net *net; 1004 u32 pid; 1005 u32 group; 1006 int failure; 1007 int delivery_failure; 1008 int congested; 1009 int delivered; 1010 gfp_t allocation; 1011 struct sk_buff *skb, *skb2; 1012 int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); 1013 void *tx_data; 1014 }; 1015 1016 static int do_one_broadcast(struct sock *sk, 1017 struct netlink_broadcast_data *p) 1018 { 1019 struct netlink_sock *nlk = nlk_sk(sk); 1020 int val; 1021 1022 if (p->exclude_sk == sk) 1023 goto out; 1024 1025 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || 1026 !test_bit(p->group - 1, nlk->groups)) 1027 goto out; 1028 1029 if (!net_eq(sock_net(sk), p->net)) 1030 goto out; 1031 1032 if (p->failure) { 1033 netlink_overrun(sk); 1034 goto out; 1035 } 1036 1037 sock_hold(sk); 1038 if (p->skb2 == NULL) { 1039 if (skb_shared(p->skb)) { 1040 p->skb2 = skb_clone(p->skb, p->allocation); 1041 } else { 1042 p->skb2 = skb_get(p->skb); 1043 /* 1044 * skb ownership may have been set when 1045 * delivered to a previous socket. 1046 */ 1047 skb_orphan(p->skb2); 1048 } 1049 } 1050 if (p->skb2 == NULL) { 1051 netlink_overrun(sk); 1052 /* Clone failed. Notify ALL listeners. */ 1053 p->failure = 1; 1054 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) 1055 p->delivery_failure = 1; 1056 } else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { 1057 kfree_skb(p->skb2); 1058 p->skb2 = NULL; 1059 } else if (sk_filter(sk, p->skb2)) { 1060 kfree_skb(p->skb2); 1061 p->skb2 = NULL; 1062 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { 1063 netlink_overrun(sk); 1064 if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) 1065 p->delivery_failure = 1; 1066 } else { 1067 p->congested |= val; 1068 p->delivered = 1; 1069 p->skb2 = NULL; 1070 } 1071 sock_put(sk); 1072 1073 out: 1074 return 0; 1075 } 1076 1077 int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 pid, 1078 u32 group, gfp_t allocation, 1079 int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), 1080 void *filter_data) 1081 { 1082 struct net *net = sock_net(ssk); 1083 struct netlink_broadcast_data info; 1084 struct hlist_node *node; 1085 struct sock *sk; 1086 1087 skb = netlink_trim(skb, allocation); 1088 1089 info.exclude_sk = ssk; 1090 info.net = net; 1091 info.pid = pid; 1092 info.group = group; 1093 info.failure = 0; 1094 info.delivery_failure = 0; 1095 info.congested = 0; 1096 info.delivered = 0; 1097 info.allocation = allocation; 1098 info.skb = skb; 1099 info.skb2 = NULL; 1100 info.tx_filter = filter; 1101 info.tx_data = filter_data; 1102 1103 /* While we sleep in clone, do not allow to change socket list */ 1104 1105 netlink_lock_table(); 1106 1107 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) 1108 do_one_broadcast(sk, &info); 1109 1110 consume_skb(skb); 1111 1112 netlink_unlock_table(); 1113 1114 if (info.delivery_failure) { 1115 kfree_skb(info.skb2); 1116 return -ENOBUFS; 1117 } 1118 consume_skb(info.skb2); 1119 1120 if (info.delivered) { 1121 if (info.congested && (allocation & __GFP_WAIT)) 1122 yield(); 1123 return 0; 1124 } 1125 return -ESRCH; 1126 } 1127 EXPORT_SYMBOL(netlink_broadcast_filtered); 1128 1129 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, 1130 u32 group, gfp_t allocation) 1131 { 1132 return netlink_broadcast_filtered(ssk, skb, pid, group, allocation, 1133 NULL, NULL); 1134 } 1135 EXPORT_SYMBOL(netlink_broadcast); 1136 1137 struct netlink_set_err_data { 1138 struct sock *exclude_sk; 1139 u32 pid; 1140 u32 group; 1141 int code; 1142 }; 1143 1144 static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) 1145 { 1146 struct netlink_sock *nlk = nlk_sk(sk); 1147 int ret = 0; 1148 1149 if (sk == p->exclude_sk) 1150 goto out; 1151 1152 if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) 1153 goto out; 1154 1155 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || 1156 !test_bit(p->group - 1, nlk->groups)) 1157 goto out; 1158 1159 if (p->code == ENOBUFS && nlk->flags & NETLINK_RECV_NO_ENOBUFS) { 1160 ret = 1; 1161 goto out; 1162 } 1163 1164 sk->sk_err = p->code; 1165 sk->sk_error_report(sk); 1166 out: 1167 return ret; 1168 } 1169 1170 /** 1171 * netlink_set_err - report error to broadcast listeners 1172 * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() 1173 * @pid: the PID of a process that we want to skip (if any) 1174 * @groups: the broadcast group that will notice the error 1175 * @code: error code, must be negative (as usual in kernelspace) 1176 * 1177 * This function returns the number of broadcast listeners that have set the 1178 * NETLINK_RECV_NO_ENOBUFS socket option. 1179 */ 1180 int netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) 1181 { 1182 struct netlink_set_err_data info; 1183 struct hlist_node *node; 1184 struct sock *sk; 1185 int ret = 0; 1186 1187 info.exclude_sk = ssk; 1188 info.pid = pid; 1189 info.group = group; 1190 /* sk->sk_err wants a positive error value */ 1191 info.code = -code; 1192 1193 read_lock(&nl_table_lock); 1194 1195 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) 1196 ret += do_one_set_err(sk, &info); 1197 1198 read_unlock(&nl_table_lock); 1199 return ret; 1200 } 1201 EXPORT_SYMBOL(netlink_set_err); 1202 1203 /* must be called with netlink table grabbed */ 1204 static void netlink_update_socket_mc(struct netlink_sock *nlk, 1205 unsigned int group, 1206 int is_new) 1207 { 1208 int old, new = !!is_new, subscriptions; 1209 1210 old = test_bit(group - 1, nlk->groups); 1211 subscriptions = nlk->subscriptions - old + new; 1212 if (new) 1213 __set_bit(group - 1, nlk->groups); 1214 else 1215 __clear_bit(group - 1, nlk->groups); 1216 netlink_update_subscriptions(&nlk->sk, subscriptions); 1217 netlink_update_listeners(&nlk->sk); 1218 } 1219 1220 static int netlink_setsockopt(struct socket *sock, int level, int optname, 1221 char __user *optval, unsigned int optlen) 1222 { 1223 struct sock *sk = sock->sk; 1224 struct netlink_sock *nlk = nlk_sk(sk); 1225 unsigned int val = 0; 1226 int err; 1227 1228 if (level != SOL_NETLINK) 1229 return -ENOPROTOOPT; 1230 1231 if (optlen >= sizeof(int) && 1232 get_user(val, (unsigned int __user *)optval)) 1233 return -EFAULT; 1234 1235 switch (optname) { 1236 case NETLINK_PKTINFO: 1237 if (val) 1238 nlk->flags |= NETLINK_RECV_PKTINFO; 1239 else 1240 nlk->flags &= ~NETLINK_RECV_PKTINFO; 1241 err = 0; 1242 break; 1243 case NETLINK_ADD_MEMBERSHIP: 1244 case NETLINK_DROP_MEMBERSHIP: { 1245 if (!netlink_capable(sock, NL_NONROOT_RECV)) 1246 return -EPERM; 1247 err = netlink_realloc_groups(sk); 1248 if (err) 1249 return err; 1250 if (!val || val - 1 >= nlk->ngroups) 1251 return -EINVAL; 1252 netlink_table_grab(); 1253 netlink_update_socket_mc(nlk, val, 1254 optname == NETLINK_ADD_MEMBERSHIP); 1255 netlink_table_ungrab(); 1256 1257 if (nlk->netlink_bind) 1258 nlk->netlink_bind(val); 1259 1260 err = 0; 1261 break; 1262 } 1263 case NETLINK_BROADCAST_ERROR: 1264 if (val) 1265 nlk->flags |= NETLINK_BROADCAST_SEND_ERROR; 1266 else 1267 nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR; 1268 err = 0; 1269 break; 1270 case NETLINK_NO_ENOBUFS: 1271 if (val) { 1272 nlk->flags |= NETLINK_RECV_NO_ENOBUFS; 1273 clear_bit(0, &nlk->state); 1274 wake_up_interruptible(&nlk->wait); 1275 } else { 1276 nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS; 1277 } 1278 err = 0; 1279 break; 1280 default: 1281 err = -ENOPROTOOPT; 1282 } 1283 return err; 1284 } 1285 1286 static int netlink_getsockopt(struct socket *sock, int level, int optname, 1287 char __user *optval, int __user *optlen) 1288 { 1289 struct sock *sk = sock->sk; 1290 struct netlink_sock *nlk = nlk_sk(sk); 1291 int len, val, err; 1292 1293 if (level != SOL_NETLINK) 1294 return -ENOPROTOOPT; 1295 1296 if (get_user(len, optlen)) 1297 return -EFAULT; 1298 if (len < 0) 1299 return -EINVAL; 1300 1301 switch (optname) { 1302 case NETLINK_PKTINFO: 1303 if (len < sizeof(int)) 1304 return -EINVAL; 1305 len = sizeof(int); 1306 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; 1307 if (put_user(len, optlen) || 1308 put_user(val, optval)) 1309 return -EFAULT; 1310 err = 0; 1311 break; 1312 case NETLINK_BROADCAST_ERROR: 1313 if (len < sizeof(int)) 1314 return -EINVAL; 1315 len = sizeof(int); 1316 val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0; 1317 if (put_user(len, optlen) || 1318 put_user(val, optval)) 1319 return -EFAULT; 1320 err = 0; 1321 break; 1322 case NETLINK_NO_ENOBUFS: 1323 if (len < sizeof(int)) 1324 return -EINVAL; 1325 len = sizeof(int); 1326 val = nlk->flags & NETLINK_RECV_NO_ENOBUFS ? 1 : 0; 1327 if (put_user(len, optlen) || 1328 put_user(val, optval)) 1329 return -EFAULT; 1330 err = 0; 1331 break; 1332 default: 1333 err = -ENOPROTOOPT; 1334 } 1335 return err; 1336 } 1337 1338 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) 1339 { 1340 struct nl_pktinfo info; 1341 1342 info.group = NETLINK_CB(skb).dst_group; 1343 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); 1344 } 1345 1346 static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, 1347 struct msghdr *msg, size_t len) 1348 { 1349 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1350 struct sock *sk = sock->sk; 1351 struct netlink_sock *nlk = nlk_sk(sk); 1352 struct sockaddr_nl *addr = msg->msg_name; 1353 u32 dst_pid; 1354 u32 dst_group; 1355 struct sk_buff *skb; 1356 int err; 1357 struct scm_cookie scm; 1358 1359 if (msg->msg_flags&MSG_OOB) 1360 return -EOPNOTSUPP; 1361 1362 if (NULL == siocb->scm) 1363 siocb->scm = &scm; 1364 1365 err = scm_send(sock, msg, siocb->scm); 1366 if (err < 0) 1367 return err; 1368 1369 if (msg->msg_namelen) { 1370 err = -EINVAL; 1371 if (addr->nl_family != AF_NETLINK) 1372 goto out; 1373 dst_pid = addr->nl_pid; 1374 dst_group = ffs(addr->nl_groups); 1375 err = -EPERM; 1376 if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) 1377 goto out; 1378 } else { 1379 dst_pid = nlk->dst_pid; 1380 dst_group = nlk->dst_group; 1381 } 1382 1383 if (!nlk->pid) { 1384 err = netlink_autobind(sock); 1385 if (err) 1386 goto out; 1387 } 1388 1389 err = -EMSGSIZE; 1390 if (len > sk->sk_sndbuf - 32) 1391 goto out; 1392 err = -ENOBUFS; 1393 skb = alloc_skb(len, GFP_KERNEL); 1394 if (skb == NULL) 1395 goto out; 1396 1397 NETLINK_CB(skb).pid = nlk->pid; 1398 NETLINK_CB(skb).dst_group = dst_group; 1399 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1400 1401 err = -EFAULT; 1402 if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) { 1403 kfree_skb(skb); 1404 goto out; 1405 } 1406 1407 err = security_netlink_send(sk, skb); 1408 if (err) { 1409 kfree_skb(skb); 1410 goto out; 1411 } 1412 1413 if (dst_group) { 1414 atomic_inc(&skb->users); 1415 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); 1416 } 1417 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); 1418 1419 out: 1420 scm_destroy(siocb->scm); 1421 return err; 1422 } 1423 1424 static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, 1425 struct msghdr *msg, size_t len, 1426 int flags) 1427 { 1428 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1429 struct scm_cookie scm; 1430 struct sock *sk = sock->sk; 1431 struct netlink_sock *nlk = nlk_sk(sk); 1432 int noblock = flags&MSG_DONTWAIT; 1433 size_t copied; 1434 struct sk_buff *skb, *data_skb; 1435 int err, ret; 1436 1437 if (flags&MSG_OOB) 1438 return -EOPNOTSUPP; 1439 1440 copied = 0; 1441 1442 skb = skb_recv_datagram(sk, flags, noblock, &err); 1443 if (skb == NULL) 1444 goto out; 1445 1446 data_skb = skb; 1447 1448 #ifdef CONFIG_COMPAT_NETLINK_MESSAGES 1449 if (unlikely(skb_shinfo(skb)->frag_list)) { 1450 /* 1451 * If this skb has a frag_list, then here that means that we 1452 * will have to use the frag_list skb's data for compat tasks 1453 * and the regular skb's data for normal (non-compat) tasks. 1454 * 1455 * If we need to send the compat skb, assign it to the 1456 * 'data_skb' variable so that it will be used below for data 1457 * copying. We keep 'skb' for everything else, including 1458 * freeing both later. 1459 */ 1460 if (flags & MSG_CMSG_COMPAT) 1461 data_skb = skb_shinfo(skb)->frag_list; 1462 } 1463 #endif 1464 1465 msg->msg_namelen = 0; 1466 1467 copied = data_skb->len; 1468 if (len < copied) { 1469 msg->msg_flags |= MSG_TRUNC; 1470 copied = len; 1471 } 1472 1473 skb_reset_transport_header(data_skb); 1474 err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied); 1475 1476 if (msg->msg_name) { 1477 struct sockaddr_nl *addr = (struct sockaddr_nl *)msg->msg_name; 1478 addr->nl_family = AF_NETLINK; 1479 addr->nl_pad = 0; 1480 addr->nl_pid = NETLINK_CB(skb).pid; 1481 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); 1482 msg->msg_namelen = sizeof(*addr); 1483 } 1484 1485 if (nlk->flags & NETLINK_RECV_PKTINFO) 1486 netlink_cmsg_recv_pktinfo(msg, skb); 1487 1488 if (NULL == siocb->scm) { 1489 memset(&scm, 0, sizeof(scm)); 1490 siocb->scm = &scm; 1491 } 1492 siocb->scm->creds = *NETLINK_CREDS(skb); 1493 if (flags & MSG_TRUNC) 1494 copied = data_skb->len; 1495 1496 skb_free_datagram(sk, skb); 1497 1498 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { 1499 ret = netlink_dump(sk); 1500 if (ret) { 1501 sk->sk_err = ret; 1502 sk->sk_error_report(sk); 1503 } 1504 } 1505 1506 scm_recv(sock, msg, siocb->scm, flags); 1507 out: 1508 netlink_rcv_wake(sk); 1509 return err ? : copied; 1510 } 1511 1512 static void netlink_data_ready(struct sock *sk, int len) 1513 { 1514 BUG(); 1515 } 1516 1517 /* 1518 * We export these functions to other modules. They provide a 1519 * complete set of kernel non-blocking support for message 1520 * queueing. 1521 */ 1522 1523 struct sock * 1524 netlink_kernel_create(struct net *net, int unit, 1525 struct module *module, 1526 struct netlink_kernel_cfg *cfg) 1527 { 1528 struct socket *sock; 1529 struct sock *sk; 1530 struct netlink_sock *nlk; 1531 struct listeners *listeners = NULL; 1532 struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; 1533 unsigned int groups; 1534 1535 BUG_ON(!nl_table); 1536 1537 if (unit < 0 || unit >= MAX_LINKS) 1538 return NULL; 1539 1540 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) 1541 return NULL; 1542 1543 /* 1544 * We have to just have a reference on the net from sk, but don't 1545 * get_net it. Besides, we cannot get and then put the net here. 1546 * So we create one inside init_net and the move it to net. 1547 */ 1548 1549 if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0) 1550 goto out_sock_release_nosk; 1551 1552 sk = sock->sk; 1553 sk_change_net(sk, net); 1554 1555 if (!cfg || cfg->groups < 32) 1556 groups = 32; 1557 else 1558 groups = cfg->groups; 1559 1560 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); 1561 if (!listeners) 1562 goto out_sock_release; 1563 1564 sk->sk_data_ready = netlink_data_ready; 1565 if (cfg && cfg->input) 1566 nlk_sk(sk)->netlink_rcv = cfg->input; 1567 1568 if (netlink_insert(sk, net, 0)) 1569 goto out_sock_release; 1570 1571 nlk = nlk_sk(sk); 1572 nlk->flags |= NETLINK_KERNEL_SOCKET; 1573 1574 netlink_table_grab(); 1575 if (!nl_table[unit].registered) { 1576 nl_table[unit].groups = groups; 1577 rcu_assign_pointer(nl_table[unit].listeners, listeners); 1578 nl_table[unit].cb_mutex = cb_mutex; 1579 nl_table[unit].module = module; 1580 nl_table[unit].bind = cfg ? cfg->bind : NULL; 1581 nl_table[unit].registered = 1; 1582 } else { 1583 kfree(listeners); 1584 nl_table[unit].registered++; 1585 } 1586 netlink_table_ungrab(); 1587 return sk; 1588 1589 out_sock_release: 1590 kfree(listeners); 1591 netlink_kernel_release(sk); 1592 return NULL; 1593 1594 out_sock_release_nosk: 1595 sock_release(sock); 1596 return NULL; 1597 } 1598 EXPORT_SYMBOL(netlink_kernel_create); 1599 1600 1601 void 1602 netlink_kernel_release(struct sock *sk) 1603 { 1604 sk_release_kernel(sk); 1605 } 1606 EXPORT_SYMBOL(netlink_kernel_release); 1607 1608 int __netlink_change_ngroups(struct sock *sk, unsigned int groups) 1609 { 1610 struct listeners *new, *old; 1611 struct netlink_table *tbl = &nl_table[sk->sk_protocol]; 1612 1613 if (groups < 32) 1614 groups = 32; 1615 1616 if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { 1617 new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); 1618 if (!new) 1619 return -ENOMEM; 1620 old = rcu_dereference_protected(tbl->listeners, 1); 1621 memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); 1622 rcu_assign_pointer(tbl->listeners, new); 1623 1624 kfree_rcu(old, rcu); 1625 } 1626 tbl->groups = groups; 1627 1628 return 0; 1629 } 1630 1631 /** 1632 * netlink_change_ngroups - change number of multicast groups 1633 * 1634 * This changes the number of multicast groups that are available 1635 * on a certain netlink family. Note that it is not possible to 1636 * change the number of groups to below 32. Also note that it does 1637 * not implicitly call netlink_clear_multicast_users() when the 1638 * number of groups is reduced. 1639 * 1640 * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). 1641 * @groups: The new number of groups. 1642 */ 1643 int netlink_change_ngroups(struct sock *sk, unsigned int groups) 1644 { 1645 int err; 1646 1647 netlink_table_grab(); 1648 err = __netlink_change_ngroups(sk, groups); 1649 netlink_table_ungrab(); 1650 1651 return err; 1652 } 1653 1654 void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) 1655 { 1656 struct sock *sk; 1657 struct hlist_node *node; 1658 struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; 1659 1660 sk_for_each_bound(sk, node, &tbl->mc_list) 1661 netlink_update_socket_mc(nlk_sk(sk), group, 0); 1662 } 1663 1664 /** 1665 * netlink_clear_multicast_users - kick off multicast listeners 1666 * 1667 * This function removes all listeners from the given group. 1668 * @ksk: The kernel netlink socket, as returned by 1669 * netlink_kernel_create(). 1670 * @group: The multicast group to clear. 1671 */ 1672 void netlink_clear_multicast_users(struct sock *ksk, unsigned int group) 1673 { 1674 netlink_table_grab(); 1675 __netlink_clear_multicast_users(ksk, group); 1676 netlink_table_ungrab(); 1677 } 1678 1679 void netlink_set_nonroot(int protocol, unsigned int flags) 1680 { 1681 if ((unsigned int)protocol < MAX_LINKS) 1682 nl_table[protocol].nl_nonroot = flags; 1683 } 1684 EXPORT_SYMBOL(netlink_set_nonroot); 1685 1686 struct nlmsghdr * 1687 __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags) 1688 { 1689 struct nlmsghdr *nlh; 1690 int size = NLMSG_LENGTH(len); 1691 1692 nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size)); 1693 nlh->nlmsg_type = type; 1694 nlh->nlmsg_len = size; 1695 nlh->nlmsg_flags = flags; 1696 nlh->nlmsg_pid = pid; 1697 nlh->nlmsg_seq = seq; 1698 if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) 1699 memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size); 1700 return nlh; 1701 } 1702 EXPORT_SYMBOL(__nlmsg_put); 1703 1704 /* 1705 * It looks a bit ugly. 1706 * It would be better to create kernel thread. 1707 */ 1708 1709 static int netlink_dump(struct sock *sk) 1710 { 1711 struct netlink_sock *nlk = nlk_sk(sk); 1712 struct netlink_callback *cb; 1713 struct sk_buff *skb = NULL; 1714 struct nlmsghdr *nlh; 1715 int len, err = -ENOBUFS; 1716 int alloc_size; 1717 1718 mutex_lock(nlk->cb_mutex); 1719 1720 cb = nlk->cb; 1721 if (cb == NULL) { 1722 err = -EINVAL; 1723 goto errout_skb; 1724 } 1725 1726 alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); 1727 1728 skb = sock_rmalloc(sk, alloc_size, 0, GFP_KERNEL); 1729 if (!skb) 1730 goto errout_skb; 1731 1732 len = cb->dump(skb, cb); 1733 1734 if (len > 0) { 1735 mutex_unlock(nlk->cb_mutex); 1736 1737 if (sk_filter(sk, skb)) 1738 kfree_skb(skb); 1739 else 1740 __netlink_sendskb(sk, skb); 1741 return 0; 1742 } 1743 1744 nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); 1745 if (!nlh) 1746 goto errout_skb; 1747 1748 nl_dump_check_consistent(cb, nlh); 1749 1750 memcpy(nlmsg_data(nlh), &len, sizeof(len)); 1751 1752 if (sk_filter(sk, skb)) 1753 kfree_skb(skb); 1754 else 1755 __netlink_sendskb(sk, skb); 1756 1757 if (cb->done) 1758 cb->done(cb); 1759 nlk->cb = NULL; 1760 mutex_unlock(nlk->cb_mutex); 1761 1762 netlink_consume_callback(cb); 1763 return 0; 1764 1765 errout_skb: 1766 mutex_unlock(nlk->cb_mutex); 1767 kfree_skb(skb); 1768 return err; 1769 } 1770 1771 int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, 1772 const struct nlmsghdr *nlh, 1773 struct netlink_dump_control *control) 1774 { 1775 struct netlink_callback *cb; 1776 struct sock *sk; 1777 struct netlink_sock *nlk; 1778 int ret; 1779 1780 cb = kzalloc(sizeof(*cb), GFP_KERNEL); 1781 if (cb == NULL) 1782 return -ENOBUFS; 1783 1784 cb->dump = control->dump; 1785 cb->done = control->done; 1786 cb->nlh = nlh; 1787 cb->data = control->data; 1788 cb->min_dump_alloc = control->min_dump_alloc; 1789 atomic_inc(&skb->users); 1790 cb->skb = skb; 1791 1792 sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).pid); 1793 if (sk == NULL) { 1794 netlink_destroy_callback(cb); 1795 return -ECONNREFUSED; 1796 } 1797 nlk = nlk_sk(sk); 1798 /* A dump is in progress... */ 1799 mutex_lock(nlk->cb_mutex); 1800 if (nlk->cb) { 1801 mutex_unlock(nlk->cb_mutex); 1802 netlink_destroy_callback(cb); 1803 sock_put(sk); 1804 return -EBUSY; 1805 } 1806 nlk->cb = cb; 1807 mutex_unlock(nlk->cb_mutex); 1808 1809 ret = netlink_dump(sk); 1810 1811 sock_put(sk); 1812 1813 if (ret) 1814 return ret; 1815 1816 /* We successfully started a dump, by returning -EINTR we 1817 * signal not to send ACK even if it was requested. 1818 */ 1819 return -EINTR; 1820 } 1821 EXPORT_SYMBOL(netlink_dump_start); 1822 1823 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) 1824 { 1825 struct sk_buff *skb; 1826 struct nlmsghdr *rep; 1827 struct nlmsgerr *errmsg; 1828 size_t payload = sizeof(*errmsg); 1829 1830 /* error messages get the original request appened */ 1831 if (err) 1832 payload += nlmsg_len(nlh); 1833 1834 skb = nlmsg_new(payload, GFP_KERNEL); 1835 if (!skb) { 1836 struct sock *sk; 1837 1838 sk = netlink_lookup(sock_net(in_skb->sk), 1839 in_skb->sk->sk_protocol, 1840 NETLINK_CB(in_skb).pid); 1841 if (sk) { 1842 sk->sk_err = ENOBUFS; 1843 sk->sk_error_report(sk); 1844 sock_put(sk); 1845 } 1846 return; 1847 } 1848 1849 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, 1850 NLMSG_ERROR, payload, 0); 1851 errmsg = nlmsg_data(rep); 1852 errmsg->error = err; 1853 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); 1854 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); 1855 } 1856 EXPORT_SYMBOL(netlink_ack); 1857 1858 int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, 1859 struct nlmsghdr *)) 1860 { 1861 struct nlmsghdr *nlh; 1862 int err; 1863 1864 while (skb->len >= nlmsg_total_size(0)) { 1865 int msglen; 1866 1867 nlh = nlmsg_hdr(skb); 1868 err = 0; 1869 1870 if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) 1871 return 0; 1872 1873 /* Only requests are handled by the kernel */ 1874 if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) 1875 goto ack; 1876 1877 /* Skip control messages */ 1878 if (nlh->nlmsg_type < NLMSG_MIN_TYPE) 1879 goto ack; 1880 1881 err = cb(skb, nlh); 1882 if (err == -EINTR) 1883 goto skip; 1884 1885 ack: 1886 if (nlh->nlmsg_flags & NLM_F_ACK || err) 1887 netlink_ack(skb, nlh, err); 1888 1889 skip: 1890 msglen = NLMSG_ALIGN(nlh->nlmsg_len); 1891 if (msglen > skb->len) 1892 msglen = skb->len; 1893 skb_pull(skb, msglen); 1894 } 1895 1896 return 0; 1897 } 1898 EXPORT_SYMBOL(netlink_rcv_skb); 1899 1900 /** 1901 * nlmsg_notify - send a notification netlink message 1902 * @sk: netlink socket to use 1903 * @skb: notification message 1904 * @pid: destination netlink pid for reports or 0 1905 * @group: destination multicast group or 0 1906 * @report: 1 to report back, 0 to disable 1907 * @flags: allocation flags 1908 */ 1909 int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, 1910 unsigned int group, int report, gfp_t flags) 1911 { 1912 int err = 0; 1913 1914 if (group) { 1915 int exclude_pid = 0; 1916 1917 if (report) { 1918 atomic_inc(&skb->users); 1919 exclude_pid = pid; 1920 } 1921 1922 /* errors reported via destination sk->sk_err, but propagate 1923 * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ 1924 err = nlmsg_multicast(sk, skb, exclude_pid, group, flags); 1925 } 1926 1927 if (report) { 1928 int err2; 1929 1930 err2 = nlmsg_unicast(sk, skb, pid); 1931 if (!err || err == -ESRCH) 1932 err = err2; 1933 } 1934 1935 return err; 1936 } 1937 EXPORT_SYMBOL(nlmsg_notify); 1938 1939 #ifdef CONFIG_PROC_FS 1940 struct nl_seq_iter { 1941 struct seq_net_private p; 1942 int link; 1943 int hash_idx; 1944 }; 1945 1946 static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) 1947 { 1948 struct nl_seq_iter *iter = seq->private; 1949 int i, j; 1950 struct sock *s; 1951 struct hlist_node *node; 1952 loff_t off = 0; 1953 1954 for (i = 0; i < MAX_LINKS; i++) { 1955 struct nl_pid_hash *hash = &nl_table[i].hash; 1956 1957 for (j = 0; j <= hash->mask; j++) { 1958 sk_for_each(s, node, &hash->table[j]) { 1959 if (sock_net(s) != seq_file_net(seq)) 1960 continue; 1961 if (off == pos) { 1962 iter->link = i; 1963 iter->hash_idx = j; 1964 return s; 1965 } 1966 ++off; 1967 } 1968 } 1969 } 1970 return NULL; 1971 } 1972 1973 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) 1974 __acquires(nl_table_lock) 1975 { 1976 read_lock(&nl_table_lock); 1977 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; 1978 } 1979 1980 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1981 { 1982 struct sock *s; 1983 struct nl_seq_iter *iter; 1984 int i, j; 1985 1986 ++*pos; 1987 1988 if (v == SEQ_START_TOKEN) 1989 return netlink_seq_socket_idx(seq, 0); 1990 1991 iter = seq->private; 1992 s = v; 1993 do { 1994 s = sk_next(s); 1995 } while (s && sock_net(s) != seq_file_net(seq)); 1996 if (s) 1997 return s; 1998 1999 i = iter->link; 2000 j = iter->hash_idx + 1; 2001 2002 do { 2003 struct nl_pid_hash *hash = &nl_table[i].hash; 2004 2005 for (; j <= hash->mask; j++) { 2006 s = sk_head(&hash->table[j]); 2007 while (s && sock_net(s) != seq_file_net(seq)) 2008 s = sk_next(s); 2009 if (s) { 2010 iter->link = i; 2011 iter->hash_idx = j; 2012 return s; 2013 } 2014 } 2015 2016 j = 0; 2017 } while (++i < MAX_LINKS); 2018 2019 return NULL; 2020 } 2021 2022 static void netlink_seq_stop(struct seq_file *seq, void *v) 2023 __releases(nl_table_lock) 2024 { 2025 read_unlock(&nl_table_lock); 2026 } 2027 2028 2029 static int netlink_seq_show(struct seq_file *seq, void *v) 2030 { 2031 if (v == SEQ_START_TOKEN) { 2032 seq_puts(seq, 2033 "sk Eth Pid Groups " 2034 "Rmem Wmem Dump Locks Drops Inode\n"); 2035 } else { 2036 struct sock *s = v; 2037 struct netlink_sock *nlk = nlk_sk(s); 2038 2039 seq_printf(seq, "%pK %-3d %-6d %08x %-8d %-8d %pK %-8d %-8d %-8lu\n", 2040 s, 2041 s->sk_protocol, 2042 nlk->pid, 2043 nlk->groups ? (u32)nlk->groups[0] : 0, 2044 sk_rmem_alloc_get(s), 2045 sk_wmem_alloc_get(s), 2046 nlk->cb, 2047 atomic_read(&s->sk_refcnt), 2048 atomic_read(&s->sk_drops), 2049 sock_i_ino(s) 2050 ); 2051 2052 } 2053 return 0; 2054 } 2055 2056 static const struct seq_operations netlink_seq_ops = { 2057 .start = netlink_seq_start, 2058 .next = netlink_seq_next, 2059 .stop = netlink_seq_stop, 2060 .show = netlink_seq_show, 2061 }; 2062 2063 2064 static int netlink_seq_open(struct inode *inode, struct file *file) 2065 { 2066 return seq_open_net(inode, file, &netlink_seq_ops, 2067 sizeof(struct nl_seq_iter)); 2068 } 2069 2070 static const struct file_operations netlink_seq_fops = { 2071 .owner = THIS_MODULE, 2072 .open = netlink_seq_open, 2073 .read = seq_read, 2074 .llseek = seq_lseek, 2075 .release = seq_release_net, 2076 }; 2077 2078 #endif 2079 2080 int netlink_register_notifier(struct notifier_block *nb) 2081 { 2082 return atomic_notifier_chain_register(&netlink_chain, nb); 2083 } 2084 EXPORT_SYMBOL(netlink_register_notifier); 2085 2086 int netlink_unregister_notifier(struct notifier_block *nb) 2087 { 2088 return atomic_notifier_chain_unregister(&netlink_chain, nb); 2089 } 2090 EXPORT_SYMBOL(netlink_unregister_notifier); 2091 2092 static const struct proto_ops netlink_ops = { 2093 .family = PF_NETLINK, 2094 .owner = THIS_MODULE, 2095 .release = netlink_release, 2096 .bind = netlink_bind, 2097 .connect = netlink_connect, 2098 .socketpair = sock_no_socketpair, 2099 .accept = sock_no_accept, 2100 .getname = netlink_getname, 2101 .poll = datagram_poll, 2102 .ioctl = sock_no_ioctl, 2103 .listen = sock_no_listen, 2104 .shutdown = sock_no_shutdown, 2105 .setsockopt = netlink_setsockopt, 2106 .getsockopt = netlink_getsockopt, 2107 .sendmsg = netlink_sendmsg, 2108 .recvmsg = netlink_recvmsg, 2109 .mmap = sock_no_mmap, 2110 .sendpage = sock_no_sendpage, 2111 }; 2112 2113 static const struct net_proto_family netlink_family_ops = { 2114 .family = PF_NETLINK, 2115 .create = netlink_create, 2116 .owner = THIS_MODULE, /* for consistency 8) */ 2117 }; 2118 2119 static int __net_init netlink_net_init(struct net *net) 2120 { 2121 #ifdef CONFIG_PROC_FS 2122 if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops)) 2123 return -ENOMEM; 2124 #endif 2125 return 0; 2126 } 2127 2128 static void __net_exit netlink_net_exit(struct net *net) 2129 { 2130 #ifdef CONFIG_PROC_FS 2131 proc_net_remove(net, "netlink"); 2132 #endif 2133 } 2134 2135 static void __init netlink_add_usersock_entry(void) 2136 { 2137 struct listeners *listeners; 2138 int groups = 32; 2139 2140 listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); 2141 if (!listeners) 2142 panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); 2143 2144 netlink_table_grab(); 2145 2146 nl_table[NETLINK_USERSOCK].groups = groups; 2147 rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); 2148 nl_table[NETLINK_USERSOCK].module = THIS_MODULE; 2149 nl_table[NETLINK_USERSOCK].registered = 1; 2150 2151 netlink_table_ungrab(); 2152 } 2153 2154 static struct pernet_operations __net_initdata netlink_net_ops = { 2155 .init = netlink_net_init, 2156 .exit = netlink_net_exit, 2157 }; 2158 2159 static int __init netlink_proto_init(void) 2160 { 2161 struct sk_buff *dummy_skb; 2162 int i; 2163 unsigned long limit; 2164 unsigned int order; 2165 int err = proto_register(&netlink_proto, 0); 2166 2167 if (err != 0) 2168 goto out; 2169 2170 BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)); 2171 2172 nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); 2173 if (!nl_table) 2174 goto panic; 2175 2176 if (totalram_pages >= (128 * 1024)) 2177 limit = totalram_pages >> (21 - PAGE_SHIFT); 2178 else 2179 limit = totalram_pages >> (23 - PAGE_SHIFT); 2180 2181 order = get_bitmask_order(limit) - 1 + PAGE_SHIFT; 2182 limit = (1UL << order) / sizeof(struct hlist_head); 2183 order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1; 2184 2185 for (i = 0; i < MAX_LINKS; i++) { 2186 struct nl_pid_hash *hash = &nl_table[i].hash; 2187 2188 hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table)); 2189 if (!hash->table) { 2190 while (i-- > 0) 2191 nl_pid_hash_free(nl_table[i].hash.table, 2192 1 * sizeof(*hash->table)); 2193 kfree(nl_table); 2194 goto panic; 2195 } 2196 hash->max_shift = order; 2197 hash->shift = 0; 2198 hash->mask = 0; 2199 hash->rehash_time = jiffies; 2200 } 2201 2202 netlink_add_usersock_entry(); 2203 2204 sock_register(&netlink_family_ops); 2205 register_pernet_subsys(&netlink_net_ops); 2206 /* The netlink device handler may be needed early. */ 2207 rtnetlink_init(); 2208 out: 2209 return err; 2210 panic: 2211 panic("netlink_init: Cannot allocate nl_table\n"); 2212 } 2213 2214 core_initcall(netlink_proto_init); 2215