1 /* 2 * NETLINK Kernel-user communication protocol. 3 * 4 * Authors: Alan Cox <alan@redhat.com> 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/config.h> 25 #include <linux/module.h> 26 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/smp_lock.h> 49 #include <linux/notifier.h> 50 #include <linux/security.h> 51 #include <linux/jhash.h> 52 #include <linux/jiffies.h> 53 #include <linux/random.h> 54 #include <linux/bitops.h> 55 #include <linux/mm.h> 56 #include <linux/types.h> 57 #include <linux/audit.h> 58 59 #include <net/sock.h> 60 #include <net/scm.h> 61 62 #define Nprintk(a...) 63 #define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8) 64 65 struct netlink_sock { 66 /* struct sock has to be the first member of netlink_sock */ 67 struct sock sk; 68 u32 pid; 69 u32 dst_pid; 70 u32 dst_group; 71 u32 flags; 72 u32 subscriptions; 73 u32 ngroups; 74 unsigned long *groups; 75 unsigned long state; 76 wait_queue_head_t wait; 77 struct netlink_callback *cb; 78 spinlock_t cb_lock; 79 void (*data_ready)(struct sock *sk, int bytes); 80 struct module *module; 81 }; 82 83 #define NETLINK_KERNEL_SOCKET 0x1 84 #define NETLINK_RECV_PKTINFO 0x2 85 86 static inline struct netlink_sock *nlk_sk(struct sock *sk) 87 { 88 return (struct netlink_sock *)sk; 89 } 90 91 struct nl_pid_hash { 92 struct hlist_head *table; 93 unsigned long rehash_time; 94 95 unsigned int mask; 96 unsigned int shift; 97 98 unsigned int entries; 99 unsigned int max_shift; 100 101 u32 rnd; 102 }; 103 104 struct netlink_table { 105 struct nl_pid_hash hash; 106 struct hlist_head mc_list; 107 unsigned int nl_nonroot; 108 unsigned int groups; 109 struct module *module; 110 int registered; 111 }; 112 113 static struct netlink_table *nl_table; 114 115 static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); 116 117 static int netlink_dump(struct sock *sk); 118 static void netlink_destroy_callback(struct netlink_callback *cb); 119 120 static DEFINE_RWLOCK(nl_table_lock); 121 static atomic_t nl_table_users = ATOMIC_INIT(0); 122 123 static struct notifier_block *netlink_chain; 124 125 static u32 netlink_group_mask(u32 group) 126 { 127 return group ? 1 << (group - 1) : 0; 128 } 129 130 static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid) 131 { 132 return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask]; 133 } 134 135 static void netlink_sock_destruct(struct sock *sk) 136 { 137 skb_queue_purge(&sk->sk_receive_queue); 138 139 if (!sock_flag(sk, SOCK_DEAD)) { 140 printk("Freeing alive netlink socket %p\n", sk); 141 return; 142 } 143 BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc)); 144 BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc)); 145 BUG_TRAP(!nlk_sk(sk)->cb); 146 BUG_TRAP(!nlk_sk(sk)->groups); 147 } 148 149 /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on SMP. 150 * Look, when several writers sleep and reader wakes them up, all but one 151 * immediately hit write lock and grab all the cpus. Exclusive sleep solves 152 * this, _but_ remember, it adds useless work on UP machines. 153 */ 154 155 static void netlink_table_grab(void) 156 { 157 write_lock_bh(&nl_table_lock); 158 159 if (atomic_read(&nl_table_users)) { 160 DECLARE_WAITQUEUE(wait, current); 161 162 add_wait_queue_exclusive(&nl_table_wait, &wait); 163 for(;;) { 164 set_current_state(TASK_UNINTERRUPTIBLE); 165 if (atomic_read(&nl_table_users) == 0) 166 break; 167 write_unlock_bh(&nl_table_lock); 168 schedule(); 169 write_lock_bh(&nl_table_lock); 170 } 171 172 __set_current_state(TASK_RUNNING); 173 remove_wait_queue(&nl_table_wait, &wait); 174 } 175 } 176 177 static __inline__ void netlink_table_ungrab(void) 178 { 179 write_unlock_bh(&nl_table_lock); 180 wake_up(&nl_table_wait); 181 } 182 183 static __inline__ void 184 netlink_lock_table(void) 185 { 186 /* read_lock() synchronizes us to netlink_table_grab */ 187 188 read_lock(&nl_table_lock); 189 atomic_inc(&nl_table_users); 190 read_unlock(&nl_table_lock); 191 } 192 193 static __inline__ void 194 netlink_unlock_table(void) 195 { 196 if (atomic_dec_and_test(&nl_table_users)) 197 wake_up(&nl_table_wait); 198 } 199 200 static __inline__ struct sock *netlink_lookup(int protocol, u32 pid) 201 { 202 struct nl_pid_hash *hash = &nl_table[protocol].hash; 203 struct hlist_head *head; 204 struct sock *sk; 205 struct hlist_node *node; 206 207 read_lock(&nl_table_lock); 208 head = nl_pid_hashfn(hash, pid); 209 sk_for_each(sk, node, head) { 210 if (nlk_sk(sk)->pid == pid) { 211 sock_hold(sk); 212 goto found; 213 } 214 } 215 sk = NULL; 216 found: 217 read_unlock(&nl_table_lock); 218 return sk; 219 } 220 221 static inline struct hlist_head *nl_pid_hash_alloc(size_t size) 222 { 223 if (size <= PAGE_SIZE) 224 return kmalloc(size, GFP_ATOMIC); 225 else 226 return (struct hlist_head *) 227 __get_free_pages(GFP_ATOMIC, get_order(size)); 228 } 229 230 static inline void nl_pid_hash_free(struct hlist_head *table, size_t size) 231 { 232 if (size <= PAGE_SIZE) 233 kfree(table); 234 else 235 free_pages((unsigned long)table, get_order(size)); 236 } 237 238 static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow) 239 { 240 unsigned int omask, mask, shift; 241 size_t osize, size; 242 struct hlist_head *otable, *table; 243 int i; 244 245 omask = mask = hash->mask; 246 osize = size = (mask + 1) * sizeof(*table); 247 shift = hash->shift; 248 249 if (grow) { 250 if (++shift > hash->max_shift) 251 return 0; 252 mask = mask * 2 + 1; 253 size *= 2; 254 } 255 256 table = nl_pid_hash_alloc(size); 257 if (!table) 258 return 0; 259 260 memset(table, 0, size); 261 otable = hash->table; 262 hash->table = table; 263 hash->mask = mask; 264 hash->shift = shift; 265 get_random_bytes(&hash->rnd, sizeof(hash->rnd)); 266 267 for (i = 0; i <= omask; i++) { 268 struct sock *sk; 269 struct hlist_node *node, *tmp; 270 271 sk_for_each_safe(sk, node, tmp, &otable[i]) 272 __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid)); 273 } 274 275 nl_pid_hash_free(otable, osize); 276 hash->rehash_time = jiffies + 10 * 60 * HZ; 277 return 1; 278 } 279 280 static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len) 281 { 282 int avg = hash->entries >> hash->shift; 283 284 if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1)) 285 return 1; 286 287 if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) { 288 nl_pid_hash_rehash(hash, 0); 289 return 1; 290 } 291 292 return 0; 293 } 294 295 static struct proto_ops netlink_ops; 296 297 static int netlink_insert(struct sock *sk, u32 pid) 298 { 299 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; 300 struct hlist_head *head; 301 int err = -EADDRINUSE; 302 struct sock *osk; 303 struct hlist_node *node; 304 int len; 305 306 netlink_table_grab(); 307 head = nl_pid_hashfn(hash, pid); 308 len = 0; 309 sk_for_each(osk, node, head) { 310 if (nlk_sk(osk)->pid == pid) 311 break; 312 len++; 313 } 314 if (node) 315 goto err; 316 317 err = -EBUSY; 318 if (nlk_sk(sk)->pid) 319 goto err; 320 321 err = -ENOMEM; 322 if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX)) 323 goto err; 324 325 if (len && nl_pid_hash_dilute(hash, len)) 326 head = nl_pid_hashfn(hash, pid); 327 hash->entries++; 328 nlk_sk(sk)->pid = pid; 329 sk_add_node(sk, head); 330 err = 0; 331 332 err: 333 netlink_table_ungrab(); 334 return err; 335 } 336 337 static void netlink_remove(struct sock *sk) 338 { 339 netlink_table_grab(); 340 if (sk_del_node_init(sk)) 341 nl_table[sk->sk_protocol].hash.entries--; 342 if (nlk_sk(sk)->subscriptions) 343 __sk_del_bind_node(sk); 344 netlink_table_ungrab(); 345 } 346 347 static struct proto netlink_proto = { 348 .name = "NETLINK", 349 .owner = THIS_MODULE, 350 .obj_size = sizeof(struct netlink_sock), 351 }; 352 353 static int __netlink_create(struct socket *sock, int protocol) 354 { 355 struct sock *sk; 356 struct netlink_sock *nlk; 357 358 sock->ops = &netlink_ops; 359 360 sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1); 361 if (!sk) 362 return -ENOMEM; 363 364 sock_init_data(sock, sk); 365 366 nlk = nlk_sk(sk); 367 spin_lock_init(&nlk->cb_lock); 368 init_waitqueue_head(&nlk->wait); 369 370 sk->sk_destruct = netlink_sock_destruct; 371 sk->sk_protocol = protocol; 372 return 0; 373 } 374 375 static int netlink_create(struct socket *sock, int protocol) 376 { 377 struct module *module = NULL; 378 struct netlink_sock *nlk; 379 unsigned int groups; 380 int err = 0; 381 382 sock->state = SS_UNCONNECTED; 383 384 if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) 385 return -ESOCKTNOSUPPORT; 386 387 if (protocol<0 || protocol >= MAX_LINKS) 388 return -EPROTONOSUPPORT; 389 390 netlink_lock_table(); 391 #ifdef CONFIG_KMOD 392 if (!nl_table[protocol].registered) { 393 netlink_unlock_table(); 394 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); 395 netlink_lock_table(); 396 } 397 #endif 398 if (nl_table[protocol].registered && 399 try_module_get(nl_table[protocol].module)) 400 module = nl_table[protocol].module; 401 else 402 err = -EPROTONOSUPPORT; 403 groups = nl_table[protocol].groups; 404 netlink_unlock_table(); 405 406 if (err || (err = __netlink_create(sock, protocol) < 0)) 407 goto out_module; 408 409 nlk = nlk_sk(sock->sk); 410 411 nlk->groups = kmalloc(NLGRPSZ(groups), GFP_KERNEL); 412 if (nlk->groups == NULL) { 413 err = -ENOMEM; 414 goto out_module; 415 } 416 memset(nlk->groups, 0, NLGRPSZ(groups)); 417 nlk->ngroups = groups; 418 419 nlk->module = module; 420 out: 421 return err; 422 423 out_module: 424 module_put(module); 425 goto out; 426 } 427 428 static int netlink_release(struct socket *sock) 429 { 430 struct sock *sk = sock->sk; 431 struct netlink_sock *nlk; 432 433 if (!sk) 434 return 0; 435 436 netlink_remove(sk); 437 nlk = nlk_sk(sk); 438 439 spin_lock(&nlk->cb_lock); 440 if (nlk->cb) { 441 nlk->cb->done(nlk->cb); 442 netlink_destroy_callback(nlk->cb); 443 nlk->cb = NULL; 444 } 445 spin_unlock(&nlk->cb_lock); 446 447 /* OK. Socket is unlinked, and, therefore, 448 no new packets will arrive */ 449 450 sock_orphan(sk); 451 sock->sk = NULL; 452 wake_up_interruptible_all(&nlk->wait); 453 454 skb_queue_purge(&sk->sk_write_queue); 455 456 if (nlk->pid && !nlk->subscriptions) { 457 struct netlink_notify n = { 458 .protocol = sk->sk_protocol, 459 .pid = nlk->pid, 460 }; 461 notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n); 462 } 463 464 if (nlk->module) 465 module_put(nlk->module); 466 467 if (nlk->flags & NETLINK_KERNEL_SOCKET) { 468 netlink_table_grab(); 469 nl_table[sk->sk_protocol].module = NULL; 470 nl_table[sk->sk_protocol].registered = 0; 471 netlink_table_ungrab(); 472 } 473 474 kfree(nlk->groups); 475 nlk->groups = NULL; 476 477 sock_put(sk); 478 return 0; 479 } 480 481 static int netlink_autobind(struct socket *sock) 482 { 483 struct sock *sk = sock->sk; 484 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; 485 struct hlist_head *head; 486 struct sock *osk; 487 struct hlist_node *node; 488 s32 pid = current->pid; 489 int err; 490 static s32 rover = -4097; 491 492 retry: 493 cond_resched(); 494 netlink_table_grab(); 495 head = nl_pid_hashfn(hash, pid); 496 sk_for_each(osk, node, head) { 497 if (nlk_sk(osk)->pid == pid) { 498 /* Bind collision, search negative pid values. */ 499 pid = rover--; 500 if (rover > -4097) 501 rover = -4097; 502 netlink_table_ungrab(); 503 goto retry; 504 } 505 } 506 netlink_table_ungrab(); 507 508 err = netlink_insert(sk, pid); 509 if (err == -EADDRINUSE) 510 goto retry; 511 512 /* If 2 threads race to autobind, that is fine. */ 513 if (err == -EBUSY) 514 err = 0; 515 516 return err; 517 } 518 519 static inline int netlink_capable(struct socket *sock, unsigned int flag) 520 { 521 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || 522 capable(CAP_NET_ADMIN); 523 } 524 525 static void 526 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) 527 { 528 struct netlink_sock *nlk = nlk_sk(sk); 529 530 if (nlk->subscriptions && !subscriptions) 531 __sk_del_bind_node(sk); 532 else if (!nlk->subscriptions && subscriptions) 533 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); 534 nlk->subscriptions = subscriptions; 535 } 536 537 static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 538 { 539 struct sock *sk = sock->sk; 540 struct netlink_sock *nlk = nlk_sk(sk); 541 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; 542 int err; 543 544 if (nladdr->nl_family != AF_NETLINK) 545 return -EINVAL; 546 547 /* Only superuser is allowed to listen multicasts */ 548 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_RECV)) 549 return -EPERM; 550 551 if (nlk->pid) { 552 if (nladdr->nl_pid != nlk->pid) 553 return -EINVAL; 554 } else { 555 err = nladdr->nl_pid ? 556 netlink_insert(sk, nladdr->nl_pid) : 557 netlink_autobind(sock); 558 if (err) 559 return err; 560 } 561 562 if (!nladdr->nl_groups && !(u32)nlk->groups[0]) 563 return 0; 564 565 netlink_table_grab(); 566 netlink_update_subscriptions(sk, nlk->subscriptions + 567 hweight32(nladdr->nl_groups) - 568 hweight32(nlk->groups[0])); 569 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; 570 netlink_table_ungrab(); 571 572 return 0; 573 } 574 575 static int netlink_connect(struct socket *sock, struct sockaddr *addr, 576 int alen, int flags) 577 { 578 int err = 0; 579 struct sock *sk = sock->sk; 580 struct netlink_sock *nlk = nlk_sk(sk); 581 struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr; 582 583 if (addr->sa_family == AF_UNSPEC) { 584 sk->sk_state = NETLINK_UNCONNECTED; 585 nlk->dst_pid = 0; 586 nlk->dst_group = 0; 587 return 0; 588 } 589 if (addr->sa_family != AF_NETLINK) 590 return -EINVAL; 591 592 /* Only superuser is allowed to send multicasts */ 593 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) 594 return -EPERM; 595 596 if (!nlk->pid) 597 err = netlink_autobind(sock); 598 599 if (err == 0) { 600 sk->sk_state = NETLINK_CONNECTED; 601 nlk->dst_pid = nladdr->nl_pid; 602 nlk->dst_group = ffs(nladdr->nl_groups); 603 } 604 605 return err; 606 } 607 608 static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer) 609 { 610 struct sock *sk = sock->sk; 611 struct netlink_sock *nlk = nlk_sk(sk); 612 struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr; 613 614 nladdr->nl_family = AF_NETLINK; 615 nladdr->nl_pad = 0; 616 *addr_len = sizeof(*nladdr); 617 618 if (peer) { 619 nladdr->nl_pid = nlk->dst_pid; 620 nladdr->nl_groups = netlink_group_mask(nlk->dst_group); 621 } else { 622 nladdr->nl_pid = nlk->pid; 623 nladdr->nl_groups = nlk->groups[0]; 624 } 625 return 0; 626 } 627 628 static void netlink_overrun(struct sock *sk) 629 { 630 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { 631 sk->sk_err = ENOBUFS; 632 sk->sk_error_report(sk); 633 } 634 } 635 636 static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) 637 { 638 int protocol = ssk->sk_protocol; 639 struct sock *sock; 640 struct netlink_sock *nlk; 641 642 sock = netlink_lookup(protocol, pid); 643 if (!sock) 644 return ERR_PTR(-ECONNREFUSED); 645 646 /* Don't bother queuing skb if kernel socket has no input function */ 647 nlk = nlk_sk(sock); 648 if ((nlk->pid == 0 && !nlk->data_ready) || 649 (sock->sk_state == NETLINK_CONNECTED && 650 nlk->dst_pid != nlk_sk(ssk)->pid)) { 651 sock_put(sock); 652 return ERR_PTR(-ECONNREFUSED); 653 } 654 return sock; 655 } 656 657 struct sock *netlink_getsockbyfilp(struct file *filp) 658 { 659 struct inode *inode = filp->f_dentry->d_inode; 660 struct sock *sock; 661 662 if (!S_ISSOCK(inode->i_mode)) 663 return ERR_PTR(-ENOTSOCK); 664 665 sock = SOCKET_I(inode)->sk; 666 if (sock->sk_family != AF_NETLINK) 667 return ERR_PTR(-EINVAL); 668 669 sock_hold(sock); 670 return sock; 671 } 672 673 /* 674 * Attach a skb to a netlink socket. 675 * The caller must hold a reference to the destination socket. On error, the 676 * reference is dropped. The skb is not send to the destination, just all 677 * all error checks are performed and memory in the queue is reserved. 678 * Return values: 679 * < 0: error. skb freed, reference to sock dropped. 680 * 0: continue 681 * 1: repeat lookup - reference dropped while waiting for socket memory. 682 */ 683 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock, long timeo) 684 { 685 struct netlink_sock *nlk; 686 687 nlk = nlk_sk(sk); 688 689 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || 690 test_bit(0, &nlk->state)) { 691 DECLARE_WAITQUEUE(wait, current); 692 if (!timeo) { 693 if (!nlk->pid) 694 netlink_overrun(sk); 695 sock_put(sk); 696 kfree_skb(skb); 697 return -EAGAIN; 698 } 699 700 __set_current_state(TASK_INTERRUPTIBLE); 701 add_wait_queue(&nlk->wait, &wait); 702 703 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || 704 test_bit(0, &nlk->state)) && 705 !sock_flag(sk, SOCK_DEAD)) 706 timeo = schedule_timeout(timeo); 707 708 __set_current_state(TASK_RUNNING); 709 remove_wait_queue(&nlk->wait, &wait); 710 sock_put(sk); 711 712 if (signal_pending(current)) { 713 kfree_skb(skb); 714 return sock_intr_errno(timeo); 715 } 716 return 1; 717 } 718 skb_set_owner_r(skb, sk); 719 return 0; 720 } 721 722 int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol) 723 { 724 struct netlink_sock *nlk; 725 int len = skb->len; 726 727 nlk = nlk_sk(sk); 728 729 skb_queue_tail(&sk->sk_receive_queue, skb); 730 sk->sk_data_ready(sk, len); 731 sock_put(sk); 732 return len; 733 } 734 735 void netlink_detachskb(struct sock *sk, struct sk_buff *skb) 736 { 737 kfree_skb(skb); 738 sock_put(sk); 739 } 740 741 static inline struct sk_buff *netlink_trim(struct sk_buff *skb, 742 unsigned int __nocast allocation) 743 { 744 int delta; 745 746 skb_orphan(skb); 747 748 delta = skb->end - skb->tail; 749 if (delta * 2 < skb->truesize) 750 return skb; 751 752 if (skb_shared(skb)) { 753 struct sk_buff *nskb = skb_clone(skb, allocation); 754 if (!nskb) 755 return skb; 756 kfree_skb(skb); 757 skb = nskb; 758 } 759 760 if (!pskb_expand_head(skb, 0, -delta, allocation)) 761 skb->truesize -= delta; 762 763 return skb; 764 } 765 766 int netlink_unicast(struct sock *ssk, struct sk_buff *skb, u32 pid, int nonblock) 767 { 768 struct sock *sk; 769 int err; 770 long timeo; 771 772 skb = netlink_trim(skb, gfp_any()); 773 774 timeo = sock_sndtimeo(ssk, nonblock); 775 retry: 776 sk = netlink_getsockbypid(ssk, pid); 777 if (IS_ERR(sk)) { 778 kfree_skb(skb); 779 return PTR_ERR(sk); 780 } 781 err = netlink_attachskb(sk, skb, nonblock, timeo); 782 if (err == 1) 783 goto retry; 784 if (err) 785 return err; 786 787 return netlink_sendskb(sk, skb, ssk->sk_protocol); 788 } 789 790 static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) 791 { 792 struct netlink_sock *nlk = nlk_sk(sk); 793 794 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && 795 !test_bit(0, &nlk->state)) { 796 skb_set_owner_r(skb, sk); 797 skb_queue_tail(&sk->sk_receive_queue, skb); 798 sk->sk_data_ready(sk, skb->len); 799 return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; 800 } 801 return -1; 802 } 803 804 struct netlink_broadcast_data { 805 struct sock *exclude_sk; 806 u32 pid; 807 u32 group; 808 int failure; 809 int congested; 810 int delivered; 811 unsigned int allocation; 812 struct sk_buff *skb, *skb2; 813 }; 814 815 static inline int do_one_broadcast(struct sock *sk, 816 struct netlink_broadcast_data *p) 817 { 818 struct netlink_sock *nlk = nlk_sk(sk); 819 int val; 820 821 if (p->exclude_sk == sk) 822 goto out; 823 824 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || 825 !test_bit(p->group - 1, nlk->groups)) 826 goto out; 827 828 if (p->failure) { 829 netlink_overrun(sk); 830 goto out; 831 } 832 833 sock_hold(sk); 834 if (p->skb2 == NULL) { 835 if (skb_shared(p->skb)) { 836 p->skb2 = skb_clone(p->skb, p->allocation); 837 } else { 838 p->skb2 = skb_get(p->skb); 839 /* 840 * skb ownership may have been set when 841 * delivered to a previous socket. 842 */ 843 skb_orphan(p->skb2); 844 } 845 } 846 if (p->skb2 == NULL) { 847 netlink_overrun(sk); 848 /* Clone failed. Notify ALL listeners. */ 849 p->failure = 1; 850 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { 851 netlink_overrun(sk); 852 } else { 853 p->congested |= val; 854 p->delivered = 1; 855 p->skb2 = NULL; 856 } 857 sock_put(sk); 858 859 out: 860 return 0; 861 } 862 863 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, 864 u32 group, unsigned int __nocast allocation) 865 { 866 struct netlink_broadcast_data info; 867 struct hlist_node *node; 868 struct sock *sk; 869 870 skb = netlink_trim(skb, allocation); 871 872 info.exclude_sk = ssk; 873 info.pid = pid; 874 info.group = group; 875 info.failure = 0; 876 info.congested = 0; 877 info.delivered = 0; 878 info.allocation = allocation; 879 info.skb = skb; 880 info.skb2 = NULL; 881 882 /* While we sleep in clone, do not allow to change socket list */ 883 884 netlink_lock_table(); 885 886 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) 887 do_one_broadcast(sk, &info); 888 889 kfree_skb(skb); 890 891 netlink_unlock_table(); 892 893 if (info.skb2) 894 kfree_skb(info.skb2); 895 896 if (info.delivered) { 897 if (info.congested && (allocation & __GFP_WAIT)) 898 yield(); 899 return 0; 900 } 901 if (info.failure) 902 return -ENOBUFS; 903 return -ESRCH; 904 } 905 906 struct netlink_set_err_data { 907 struct sock *exclude_sk; 908 u32 pid; 909 u32 group; 910 int code; 911 }; 912 913 static inline int do_one_set_err(struct sock *sk, 914 struct netlink_set_err_data *p) 915 { 916 struct netlink_sock *nlk = nlk_sk(sk); 917 918 if (sk == p->exclude_sk) 919 goto out; 920 921 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || 922 !test_bit(p->group - 1, nlk->groups)) 923 goto out; 924 925 sk->sk_err = p->code; 926 sk->sk_error_report(sk); 927 out: 928 return 0; 929 } 930 931 void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) 932 { 933 struct netlink_set_err_data info; 934 struct hlist_node *node; 935 struct sock *sk; 936 937 info.exclude_sk = ssk; 938 info.pid = pid; 939 info.group = group; 940 info.code = code; 941 942 read_lock(&nl_table_lock); 943 944 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) 945 do_one_set_err(sk, &info); 946 947 read_unlock(&nl_table_lock); 948 } 949 950 static int netlink_setsockopt(struct socket *sock, int level, int optname, 951 char __user *optval, int optlen) 952 { 953 struct sock *sk = sock->sk; 954 struct netlink_sock *nlk = nlk_sk(sk); 955 int val = 0, err; 956 957 if (level != SOL_NETLINK) 958 return -ENOPROTOOPT; 959 960 if (optlen >= sizeof(int) && 961 get_user(val, (int __user *)optval)) 962 return -EFAULT; 963 964 switch (optname) { 965 case NETLINK_PKTINFO: 966 if (val) 967 nlk->flags |= NETLINK_RECV_PKTINFO; 968 else 969 nlk->flags &= ~NETLINK_RECV_PKTINFO; 970 err = 0; 971 break; 972 case NETLINK_ADD_MEMBERSHIP: 973 case NETLINK_DROP_MEMBERSHIP: { 974 unsigned int subscriptions; 975 int old, new = optname == NETLINK_ADD_MEMBERSHIP ? 1 : 0; 976 977 if (!netlink_capable(sock, NL_NONROOT_RECV)) 978 return -EPERM; 979 if (!val || val - 1 >= nlk->ngroups) 980 return -EINVAL; 981 netlink_table_grab(); 982 old = test_bit(val - 1, nlk->groups); 983 subscriptions = nlk->subscriptions - old + new; 984 if (new) 985 __set_bit(val - 1, nlk->groups); 986 else 987 __clear_bit(val - 1, nlk->groups); 988 netlink_update_subscriptions(sk, subscriptions); 989 netlink_table_ungrab(); 990 err = 0; 991 break; 992 } 993 default: 994 err = -ENOPROTOOPT; 995 } 996 return err; 997 } 998 999 static int netlink_getsockopt(struct socket *sock, int level, int optname, 1000 char __user *optval, int __user *optlen) 1001 { 1002 struct sock *sk = sock->sk; 1003 struct netlink_sock *nlk = nlk_sk(sk); 1004 int len, val, err; 1005 1006 if (level != SOL_NETLINK) 1007 return -ENOPROTOOPT; 1008 1009 if (get_user(len, optlen)) 1010 return -EFAULT; 1011 if (len < 0) 1012 return -EINVAL; 1013 1014 switch (optname) { 1015 case NETLINK_PKTINFO: 1016 if (len < sizeof(int)) 1017 return -EINVAL; 1018 len = sizeof(int); 1019 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; 1020 put_user(len, optlen); 1021 put_user(val, optval); 1022 err = 0; 1023 break; 1024 default: 1025 err = -ENOPROTOOPT; 1026 } 1027 return err; 1028 } 1029 1030 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) 1031 { 1032 struct nl_pktinfo info; 1033 1034 info.group = NETLINK_CB(skb).dst_group; 1035 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); 1036 } 1037 1038 static inline void netlink_rcv_wake(struct sock *sk) 1039 { 1040 struct netlink_sock *nlk = nlk_sk(sk); 1041 1042 if (skb_queue_empty(&sk->sk_receive_queue)) 1043 clear_bit(0, &nlk->state); 1044 if (!test_bit(0, &nlk->state)) 1045 wake_up_interruptible(&nlk->wait); 1046 } 1047 1048 static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, 1049 struct msghdr *msg, size_t len) 1050 { 1051 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1052 struct sock *sk = sock->sk; 1053 struct netlink_sock *nlk = nlk_sk(sk); 1054 struct sockaddr_nl *addr=msg->msg_name; 1055 u32 dst_pid; 1056 u32 dst_group; 1057 struct sk_buff *skb; 1058 int err; 1059 struct scm_cookie scm; 1060 1061 if (msg->msg_flags&MSG_OOB) 1062 return -EOPNOTSUPP; 1063 1064 if (NULL == siocb->scm) 1065 siocb->scm = &scm; 1066 err = scm_send(sock, msg, siocb->scm); 1067 if (err < 0) 1068 return err; 1069 1070 if (msg->msg_namelen) { 1071 if (addr->nl_family != AF_NETLINK) 1072 return -EINVAL; 1073 dst_pid = addr->nl_pid; 1074 dst_group = ffs(addr->nl_groups); 1075 if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) 1076 return -EPERM; 1077 } else { 1078 dst_pid = nlk->dst_pid; 1079 dst_group = nlk->dst_group; 1080 } 1081 1082 if (!nlk->pid) { 1083 err = netlink_autobind(sock); 1084 if (err) 1085 goto out; 1086 } 1087 1088 err = -EMSGSIZE; 1089 if (len > sk->sk_sndbuf - 32) 1090 goto out; 1091 err = -ENOBUFS; 1092 skb = alloc_skb(len, GFP_KERNEL); 1093 if (skb==NULL) 1094 goto out; 1095 1096 NETLINK_CB(skb).pid = nlk->pid; 1097 NETLINK_CB(skb).dst_pid = dst_pid; 1098 NETLINK_CB(skb).dst_group = dst_group; 1099 NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context); 1100 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1101 1102 /* What can I do? Netlink is asynchronous, so that 1103 we will have to save current capabilities to 1104 check them, when this message will be delivered 1105 to corresponding kernel module. --ANK (980802) 1106 */ 1107 1108 err = -EFAULT; 1109 if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) { 1110 kfree_skb(skb); 1111 goto out; 1112 } 1113 1114 err = security_netlink_send(sk, skb); 1115 if (err) { 1116 kfree_skb(skb); 1117 goto out; 1118 } 1119 1120 if (dst_group) { 1121 atomic_inc(&skb->users); 1122 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); 1123 } 1124 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); 1125 1126 out: 1127 return err; 1128 } 1129 1130 static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, 1131 struct msghdr *msg, size_t len, 1132 int flags) 1133 { 1134 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1135 struct scm_cookie scm; 1136 struct sock *sk = sock->sk; 1137 struct netlink_sock *nlk = nlk_sk(sk); 1138 int noblock = flags&MSG_DONTWAIT; 1139 size_t copied; 1140 struct sk_buff *skb; 1141 int err; 1142 1143 if (flags&MSG_OOB) 1144 return -EOPNOTSUPP; 1145 1146 copied = 0; 1147 1148 skb = skb_recv_datagram(sk,flags,noblock,&err); 1149 if (skb==NULL) 1150 goto out; 1151 1152 msg->msg_namelen = 0; 1153 1154 copied = skb->len; 1155 if (len < copied) { 1156 msg->msg_flags |= MSG_TRUNC; 1157 copied = len; 1158 } 1159 1160 skb->h.raw = skb->data; 1161 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 1162 1163 if (msg->msg_name) { 1164 struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name; 1165 addr->nl_family = AF_NETLINK; 1166 addr->nl_pad = 0; 1167 addr->nl_pid = NETLINK_CB(skb).pid; 1168 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); 1169 msg->msg_namelen = sizeof(*addr); 1170 } 1171 1172 if (NULL == siocb->scm) { 1173 memset(&scm, 0, sizeof(scm)); 1174 siocb->scm = &scm; 1175 } 1176 siocb->scm->creds = *NETLINK_CREDS(skb); 1177 skb_free_datagram(sk, skb); 1178 1179 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) 1180 netlink_dump(sk); 1181 1182 scm_recv(sock, msg, siocb->scm, flags); 1183 if (nlk->flags & NETLINK_RECV_PKTINFO) 1184 netlink_cmsg_recv_pktinfo(msg, skb); 1185 1186 out: 1187 netlink_rcv_wake(sk); 1188 return err ? : copied; 1189 } 1190 1191 static void netlink_data_ready(struct sock *sk, int len) 1192 { 1193 struct netlink_sock *nlk = nlk_sk(sk); 1194 1195 if (nlk->data_ready) 1196 nlk->data_ready(sk, len); 1197 netlink_rcv_wake(sk); 1198 } 1199 1200 /* 1201 * We export these functions to other modules. They provide a 1202 * complete set of kernel non-blocking support for message 1203 * queueing. 1204 */ 1205 1206 struct sock * 1207 netlink_kernel_create(int unit, unsigned int groups, 1208 void (*input)(struct sock *sk, int len), 1209 struct module *module) 1210 { 1211 struct socket *sock; 1212 struct sock *sk; 1213 struct netlink_sock *nlk; 1214 1215 if (!nl_table) 1216 return NULL; 1217 1218 if (unit<0 || unit>=MAX_LINKS) 1219 return NULL; 1220 1221 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) 1222 return NULL; 1223 1224 if (__netlink_create(sock, unit) < 0) 1225 goto out_sock_release; 1226 1227 sk = sock->sk; 1228 sk->sk_data_ready = netlink_data_ready; 1229 if (input) 1230 nlk_sk(sk)->data_ready = input; 1231 1232 if (netlink_insert(sk, 0)) 1233 goto out_sock_release; 1234 1235 nlk = nlk_sk(sk); 1236 nlk->flags |= NETLINK_KERNEL_SOCKET; 1237 1238 netlink_table_grab(); 1239 nl_table[unit].groups = groups < 32 ? 32 : groups; 1240 nl_table[unit].module = module; 1241 nl_table[unit].registered = 1; 1242 netlink_table_ungrab(); 1243 1244 return sk; 1245 1246 out_sock_release: 1247 sock_release(sock); 1248 return NULL; 1249 } 1250 1251 void netlink_set_nonroot(int protocol, unsigned int flags) 1252 { 1253 if ((unsigned int)protocol < MAX_LINKS) 1254 nl_table[protocol].nl_nonroot = flags; 1255 } 1256 1257 static void netlink_destroy_callback(struct netlink_callback *cb) 1258 { 1259 if (cb->skb) 1260 kfree_skb(cb->skb); 1261 kfree(cb); 1262 } 1263 1264 /* 1265 * It looks a bit ugly. 1266 * It would be better to create kernel thread. 1267 */ 1268 1269 static int netlink_dump(struct sock *sk) 1270 { 1271 struct netlink_sock *nlk = nlk_sk(sk); 1272 struct netlink_callback *cb; 1273 struct sk_buff *skb; 1274 struct nlmsghdr *nlh; 1275 int len; 1276 1277 skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); 1278 if (!skb) 1279 return -ENOBUFS; 1280 1281 spin_lock(&nlk->cb_lock); 1282 1283 cb = nlk->cb; 1284 if (cb == NULL) { 1285 spin_unlock(&nlk->cb_lock); 1286 kfree_skb(skb); 1287 return -EINVAL; 1288 } 1289 1290 len = cb->dump(skb, cb); 1291 1292 if (len > 0) { 1293 spin_unlock(&nlk->cb_lock); 1294 skb_queue_tail(&sk->sk_receive_queue, skb); 1295 sk->sk_data_ready(sk, len); 1296 return 0; 1297 } 1298 1299 nlh = NLMSG_NEW_ANSWER(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); 1300 memcpy(NLMSG_DATA(nlh), &len, sizeof(len)); 1301 skb_queue_tail(&sk->sk_receive_queue, skb); 1302 sk->sk_data_ready(sk, skb->len); 1303 1304 cb->done(cb); 1305 nlk->cb = NULL; 1306 spin_unlock(&nlk->cb_lock); 1307 1308 netlink_destroy_callback(cb); 1309 return 0; 1310 1311 nlmsg_failure: 1312 return -ENOBUFS; 1313 } 1314 1315 int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, 1316 struct nlmsghdr *nlh, 1317 int (*dump)(struct sk_buff *skb, struct netlink_callback*), 1318 int (*done)(struct netlink_callback*)) 1319 { 1320 struct netlink_callback *cb; 1321 struct sock *sk; 1322 struct netlink_sock *nlk; 1323 1324 cb = kmalloc(sizeof(*cb), GFP_KERNEL); 1325 if (cb == NULL) 1326 return -ENOBUFS; 1327 1328 memset(cb, 0, sizeof(*cb)); 1329 cb->dump = dump; 1330 cb->done = done; 1331 cb->nlh = nlh; 1332 atomic_inc(&skb->users); 1333 cb->skb = skb; 1334 1335 sk = netlink_lookup(ssk->sk_protocol, NETLINK_CB(skb).pid); 1336 if (sk == NULL) { 1337 netlink_destroy_callback(cb); 1338 return -ECONNREFUSED; 1339 } 1340 nlk = nlk_sk(sk); 1341 /* A dump is in progress... */ 1342 spin_lock(&nlk->cb_lock); 1343 if (nlk->cb) { 1344 spin_unlock(&nlk->cb_lock); 1345 netlink_destroy_callback(cb); 1346 sock_put(sk); 1347 return -EBUSY; 1348 } 1349 nlk->cb = cb; 1350 spin_unlock(&nlk->cb_lock); 1351 1352 netlink_dump(sk); 1353 sock_put(sk); 1354 return 0; 1355 } 1356 1357 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) 1358 { 1359 struct sk_buff *skb; 1360 struct nlmsghdr *rep; 1361 struct nlmsgerr *errmsg; 1362 int size; 1363 1364 if (err == 0) 1365 size = NLMSG_SPACE(sizeof(struct nlmsgerr)); 1366 else 1367 size = NLMSG_SPACE(4 + NLMSG_ALIGN(nlh->nlmsg_len)); 1368 1369 skb = alloc_skb(size, GFP_KERNEL); 1370 if (!skb) { 1371 struct sock *sk; 1372 1373 sk = netlink_lookup(in_skb->sk->sk_protocol, 1374 NETLINK_CB(in_skb).pid); 1375 if (sk) { 1376 sk->sk_err = ENOBUFS; 1377 sk->sk_error_report(sk); 1378 sock_put(sk); 1379 } 1380 return; 1381 } 1382 1383 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, 1384 NLMSG_ERROR, sizeof(struct nlmsgerr), 0); 1385 errmsg = NLMSG_DATA(rep); 1386 errmsg->error = err; 1387 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(struct nlmsghdr)); 1388 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); 1389 } 1390 1391 1392 #ifdef CONFIG_PROC_FS 1393 struct nl_seq_iter { 1394 int link; 1395 int hash_idx; 1396 }; 1397 1398 static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) 1399 { 1400 struct nl_seq_iter *iter = seq->private; 1401 int i, j; 1402 struct sock *s; 1403 struct hlist_node *node; 1404 loff_t off = 0; 1405 1406 for (i=0; i<MAX_LINKS; i++) { 1407 struct nl_pid_hash *hash = &nl_table[i].hash; 1408 1409 for (j = 0; j <= hash->mask; j++) { 1410 sk_for_each(s, node, &hash->table[j]) { 1411 if (off == pos) { 1412 iter->link = i; 1413 iter->hash_idx = j; 1414 return s; 1415 } 1416 ++off; 1417 } 1418 } 1419 } 1420 return NULL; 1421 } 1422 1423 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) 1424 { 1425 read_lock(&nl_table_lock); 1426 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; 1427 } 1428 1429 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1430 { 1431 struct sock *s; 1432 struct nl_seq_iter *iter; 1433 int i, j; 1434 1435 ++*pos; 1436 1437 if (v == SEQ_START_TOKEN) 1438 return netlink_seq_socket_idx(seq, 0); 1439 1440 s = sk_next(v); 1441 if (s) 1442 return s; 1443 1444 iter = seq->private; 1445 i = iter->link; 1446 j = iter->hash_idx + 1; 1447 1448 do { 1449 struct nl_pid_hash *hash = &nl_table[i].hash; 1450 1451 for (; j <= hash->mask; j++) { 1452 s = sk_head(&hash->table[j]); 1453 if (s) { 1454 iter->link = i; 1455 iter->hash_idx = j; 1456 return s; 1457 } 1458 } 1459 1460 j = 0; 1461 } while (++i < MAX_LINKS); 1462 1463 return NULL; 1464 } 1465 1466 static void netlink_seq_stop(struct seq_file *seq, void *v) 1467 { 1468 read_unlock(&nl_table_lock); 1469 } 1470 1471 1472 static int netlink_seq_show(struct seq_file *seq, void *v) 1473 { 1474 if (v == SEQ_START_TOKEN) 1475 seq_puts(seq, 1476 "sk Eth Pid Groups " 1477 "Rmem Wmem Dump Locks\n"); 1478 else { 1479 struct sock *s = v; 1480 struct netlink_sock *nlk = nlk_sk(s); 1481 1482 seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n", 1483 s, 1484 s->sk_protocol, 1485 nlk->pid, 1486 nlk->flags & NETLINK_KERNEL_SOCKET ? 1487 0 : (unsigned int)nlk->groups[0], 1488 atomic_read(&s->sk_rmem_alloc), 1489 atomic_read(&s->sk_wmem_alloc), 1490 nlk->cb, 1491 atomic_read(&s->sk_refcnt) 1492 ); 1493 1494 } 1495 return 0; 1496 } 1497 1498 static struct seq_operations netlink_seq_ops = { 1499 .start = netlink_seq_start, 1500 .next = netlink_seq_next, 1501 .stop = netlink_seq_stop, 1502 .show = netlink_seq_show, 1503 }; 1504 1505 1506 static int netlink_seq_open(struct inode *inode, struct file *file) 1507 { 1508 struct seq_file *seq; 1509 struct nl_seq_iter *iter; 1510 int err; 1511 1512 iter = kmalloc(sizeof(*iter), GFP_KERNEL); 1513 if (!iter) 1514 return -ENOMEM; 1515 1516 err = seq_open(file, &netlink_seq_ops); 1517 if (err) { 1518 kfree(iter); 1519 return err; 1520 } 1521 1522 memset(iter, 0, sizeof(*iter)); 1523 seq = file->private_data; 1524 seq->private = iter; 1525 return 0; 1526 } 1527 1528 static struct file_operations netlink_seq_fops = { 1529 .owner = THIS_MODULE, 1530 .open = netlink_seq_open, 1531 .read = seq_read, 1532 .llseek = seq_lseek, 1533 .release = seq_release_private, 1534 }; 1535 1536 #endif 1537 1538 int netlink_register_notifier(struct notifier_block *nb) 1539 { 1540 return notifier_chain_register(&netlink_chain, nb); 1541 } 1542 1543 int netlink_unregister_notifier(struct notifier_block *nb) 1544 { 1545 return notifier_chain_unregister(&netlink_chain, nb); 1546 } 1547 1548 static struct proto_ops netlink_ops = { 1549 .family = PF_NETLINK, 1550 .owner = THIS_MODULE, 1551 .release = netlink_release, 1552 .bind = netlink_bind, 1553 .connect = netlink_connect, 1554 .socketpair = sock_no_socketpair, 1555 .accept = sock_no_accept, 1556 .getname = netlink_getname, 1557 .poll = datagram_poll, 1558 .ioctl = sock_no_ioctl, 1559 .listen = sock_no_listen, 1560 .shutdown = sock_no_shutdown, 1561 .setsockopt = netlink_setsockopt, 1562 .getsockopt = netlink_getsockopt, 1563 .sendmsg = netlink_sendmsg, 1564 .recvmsg = netlink_recvmsg, 1565 .mmap = sock_no_mmap, 1566 .sendpage = sock_no_sendpage, 1567 }; 1568 1569 static struct net_proto_family netlink_family_ops = { 1570 .family = PF_NETLINK, 1571 .create = netlink_create, 1572 .owner = THIS_MODULE, /* for consistency 8) */ 1573 }; 1574 1575 extern void netlink_skb_parms_too_large(void); 1576 1577 static int __init netlink_proto_init(void) 1578 { 1579 struct sk_buff *dummy_skb; 1580 int i; 1581 unsigned long max; 1582 unsigned int order; 1583 int err = proto_register(&netlink_proto, 0); 1584 1585 if (err != 0) 1586 goto out; 1587 1588 if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)) 1589 netlink_skb_parms_too_large(); 1590 1591 nl_table = kmalloc(sizeof(*nl_table) * MAX_LINKS, GFP_KERNEL); 1592 if (!nl_table) { 1593 enomem: 1594 printk(KERN_CRIT "netlink_init: Cannot allocate nl_table\n"); 1595 return -ENOMEM; 1596 } 1597 1598 memset(nl_table, 0, sizeof(*nl_table) * MAX_LINKS); 1599 1600 if (num_physpages >= (128 * 1024)) 1601 max = num_physpages >> (21 - PAGE_SHIFT); 1602 else 1603 max = num_physpages >> (23 - PAGE_SHIFT); 1604 1605 order = get_bitmask_order(max) - 1 + PAGE_SHIFT; 1606 max = (1UL << order) / sizeof(struct hlist_head); 1607 order = get_bitmask_order(max > UINT_MAX ? UINT_MAX : max) - 1; 1608 1609 for (i = 0; i < MAX_LINKS; i++) { 1610 struct nl_pid_hash *hash = &nl_table[i].hash; 1611 1612 hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table)); 1613 if (!hash->table) { 1614 while (i-- > 0) 1615 nl_pid_hash_free(nl_table[i].hash.table, 1616 1 * sizeof(*hash->table)); 1617 kfree(nl_table); 1618 goto enomem; 1619 } 1620 memset(hash->table, 0, 1 * sizeof(*hash->table)); 1621 hash->max_shift = order; 1622 hash->shift = 0; 1623 hash->mask = 0; 1624 hash->rehash_time = jiffies; 1625 } 1626 1627 sock_register(&netlink_family_ops); 1628 #ifdef CONFIG_PROC_FS 1629 proc_net_fops_create("netlink", 0, &netlink_seq_fops); 1630 #endif 1631 /* The netlink device handler may be needed early. */ 1632 rtnetlink_init(); 1633 out: 1634 return err; 1635 } 1636 1637 core_initcall(netlink_proto_init); 1638 1639 EXPORT_SYMBOL(netlink_ack); 1640 EXPORT_SYMBOL(netlink_broadcast); 1641 EXPORT_SYMBOL(netlink_dump_start); 1642 EXPORT_SYMBOL(netlink_kernel_create); 1643 EXPORT_SYMBOL(netlink_register_notifier); 1644 EXPORT_SYMBOL(netlink_set_err); 1645 EXPORT_SYMBOL(netlink_set_nonroot); 1646 EXPORT_SYMBOL(netlink_unicast); 1647 EXPORT_SYMBOL(netlink_unregister_notifier); 1648 1649