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 groups = nl_table[protocol].groups; 402 netlink_unlock_table(); 403 404 if ((err = __netlink_create(sock, protocol) < 0)) 405 goto out_module; 406 407 nlk = nlk_sk(sock->sk); 408 nlk->module = module; 409 out: 410 return err; 411 412 out_module: 413 module_put(module); 414 goto out; 415 } 416 417 static int netlink_release(struct socket *sock) 418 { 419 struct sock *sk = sock->sk; 420 struct netlink_sock *nlk; 421 422 if (!sk) 423 return 0; 424 425 netlink_remove(sk); 426 nlk = nlk_sk(sk); 427 428 spin_lock(&nlk->cb_lock); 429 if (nlk->cb) { 430 nlk->cb->done(nlk->cb); 431 netlink_destroy_callback(nlk->cb); 432 nlk->cb = NULL; 433 } 434 spin_unlock(&nlk->cb_lock); 435 436 /* OK. Socket is unlinked, and, therefore, 437 no new packets will arrive */ 438 439 sock_orphan(sk); 440 sock->sk = NULL; 441 wake_up_interruptible_all(&nlk->wait); 442 443 skb_queue_purge(&sk->sk_write_queue); 444 445 if (nlk->pid && !nlk->subscriptions) { 446 struct netlink_notify n = { 447 .protocol = sk->sk_protocol, 448 .pid = nlk->pid, 449 }; 450 notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n); 451 } 452 453 if (nlk->module) 454 module_put(nlk->module); 455 456 if (nlk->flags & NETLINK_KERNEL_SOCKET) { 457 netlink_table_grab(); 458 nl_table[sk->sk_protocol].module = NULL; 459 nl_table[sk->sk_protocol].registered = 0; 460 netlink_table_ungrab(); 461 } 462 463 kfree(nlk->groups); 464 nlk->groups = NULL; 465 466 sock_put(sk); 467 return 0; 468 } 469 470 static int netlink_autobind(struct socket *sock) 471 { 472 struct sock *sk = sock->sk; 473 struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash; 474 struct hlist_head *head; 475 struct sock *osk; 476 struct hlist_node *node; 477 s32 pid = current->pid; 478 int err; 479 static s32 rover = -4097; 480 481 retry: 482 cond_resched(); 483 netlink_table_grab(); 484 head = nl_pid_hashfn(hash, pid); 485 sk_for_each(osk, node, head) { 486 if (nlk_sk(osk)->pid == pid) { 487 /* Bind collision, search negative pid values. */ 488 pid = rover--; 489 if (rover > -4097) 490 rover = -4097; 491 netlink_table_ungrab(); 492 goto retry; 493 } 494 } 495 netlink_table_ungrab(); 496 497 err = netlink_insert(sk, pid); 498 if (err == -EADDRINUSE) 499 goto retry; 500 501 /* If 2 threads race to autobind, that is fine. */ 502 if (err == -EBUSY) 503 err = 0; 504 505 return err; 506 } 507 508 static inline int netlink_capable(struct socket *sock, unsigned int flag) 509 { 510 return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) || 511 capable(CAP_NET_ADMIN); 512 } 513 514 static void 515 netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) 516 { 517 struct netlink_sock *nlk = nlk_sk(sk); 518 519 if (nlk->subscriptions && !subscriptions) 520 __sk_del_bind_node(sk); 521 else if (!nlk->subscriptions && subscriptions) 522 sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); 523 nlk->subscriptions = subscriptions; 524 } 525 526 static int netlink_alloc_groups(struct sock *sk) 527 { 528 struct netlink_sock *nlk = nlk_sk(sk); 529 unsigned int groups; 530 int err = 0; 531 532 netlink_lock_table(); 533 groups = nl_table[sk->sk_protocol].groups; 534 if (!nl_table[sk->sk_protocol].registered) 535 err = -ENOENT; 536 netlink_unlock_table(); 537 538 if (err) 539 return err; 540 541 nlk->groups = kmalloc(NLGRPSZ(groups), GFP_KERNEL); 542 if (nlk->groups == NULL) 543 return -ENOMEM; 544 memset(nlk->groups, 0, NLGRPSZ(groups)); 545 nlk->ngroups = groups; 546 return 0; 547 } 548 549 static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len) 550 { 551 struct sock *sk = sock->sk; 552 struct netlink_sock *nlk = nlk_sk(sk); 553 struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; 554 int err; 555 556 if (nladdr->nl_family != AF_NETLINK) 557 return -EINVAL; 558 559 /* Only superuser is allowed to listen multicasts */ 560 if (nladdr->nl_groups) { 561 if (!netlink_capable(sock, NL_NONROOT_RECV)) 562 return -EPERM; 563 if (nlk->groups == NULL) { 564 err = netlink_alloc_groups(sk); 565 if (err) 566 return err; 567 } 568 } 569 570 if (nlk->pid) { 571 if (nladdr->nl_pid != nlk->pid) 572 return -EINVAL; 573 } else { 574 err = nladdr->nl_pid ? 575 netlink_insert(sk, nladdr->nl_pid) : 576 netlink_autobind(sock); 577 if (err) 578 return err; 579 } 580 581 if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) 582 return 0; 583 584 netlink_table_grab(); 585 netlink_update_subscriptions(sk, nlk->subscriptions + 586 hweight32(nladdr->nl_groups) - 587 hweight32(nlk->groups[0])); 588 nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups; 589 netlink_table_ungrab(); 590 591 return 0; 592 } 593 594 static int netlink_connect(struct socket *sock, struct sockaddr *addr, 595 int alen, int flags) 596 { 597 int err = 0; 598 struct sock *sk = sock->sk; 599 struct netlink_sock *nlk = nlk_sk(sk); 600 struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr; 601 602 if (addr->sa_family == AF_UNSPEC) { 603 sk->sk_state = NETLINK_UNCONNECTED; 604 nlk->dst_pid = 0; 605 nlk->dst_group = 0; 606 return 0; 607 } 608 if (addr->sa_family != AF_NETLINK) 609 return -EINVAL; 610 611 /* Only superuser is allowed to send multicasts */ 612 if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND)) 613 return -EPERM; 614 615 if (!nlk->pid) 616 err = netlink_autobind(sock); 617 618 if (err == 0) { 619 sk->sk_state = NETLINK_CONNECTED; 620 nlk->dst_pid = nladdr->nl_pid; 621 nlk->dst_group = ffs(nladdr->nl_groups); 622 } 623 624 return err; 625 } 626 627 static int netlink_getname(struct socket *sock, struct sockaddr *addr, int *addr_len, int peer) 628 { 629 struct sock *sk = sock->sk; 630 struct netlink_sock *nlk = nlk_sk(sk); 631 struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr; 632 633 nladdr->nl_family = AF_NETLINK; 634 nladdr->nl_pad = 0; 635 *addr_len = sizeof(*nladdr); 636 637 if (peer) { 638 nladdr->nl_pid = nlk->dst_pid; 639 nladdr->nl_groups = netlink_group_mask(nlk->dst_group); 640 } else { 641 nladdr->nl_pid = nlk->pid; 642 nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; 643 } 644 return 0; 645 } 646 647 static void netlink_overrun(struct sock *sk) 648 { 649 if (!test_and_set_bit(0, &nlk_sk(sk)->state)) { 650 sk->sk_err = ENOBUFS; 651 sk->sk_error_report(sk); 652 } 653 } 654 655 static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid) 656 { 657 int protocol = ssk->sk_protocol; 658 struct sock *sock; 659 struct netlink_sock *nlk; 660 661 sock = netlink_lookup(protocol, pid); 662 if (!sock) 663 return ERR_PTR(-ECONNREFUSED); 664 665 /* Don't bother queuing skb if kernel socket has no input function */ 666 nlk = nlk_sk(sock); 667 if ((nlk->pid == 0 && !nlk->data_ready) || 668 (sock->sk_state == NETLINK_CONNECTED && 669 nlk->dst_pid != nlk_sk(ssk)->pid)) { 670 sock_put(sock); 671 return ERR_PTR(-ECONNREFUSED); 672 } 673 return sock; 674 } 675 676 struct sock *netlink_getsockbyfilp(struct file *filp) 677 { 678 struct inode *inode = filp->f_dentry->d_inode; 679 struct sock *sock; 680 681 if (!S_ISSOCK(inode->i_mode)) 682 return ERR_PTR(-ENOTSOCK); 683 684 sock = SOCKET_I(inode)->sk; 685 if (sock->sk_family != AF_NETLINK) 686 return ERR_PTR(-EINVAL); 687 688 sock_hold(sock); 689 return sock; 690 } 691 692 /* 693 * Attach a skb to a netlink socket. 694 * The caller must hold a reference to the destination socket. On error, the 695 * reference is dropped. The skb is not send to the destination, just all 696 * all error checks are performed and memory in the queue is reserved. 697 * Return values: 698 * < 0: error. skb freed, reference to sock dropped. 699 * 0: continue 700 * 1: repeat lookup - reference dropped while waiting for socket memory. 701 */ 702 int netlink_attachskb(struct sock *sk, struct sk_buff *skb, int nonblock, long timeo) 703 { 704 struct netlink_sock *nlk; 705 706 nlk = nlk_sk(sk); 707 708 if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || 709 test_bit(0, &nlk->state)) { 710 DECLARE_WAITQUEUE(wait, current); 711 if (!timeo) { 712 if (!nlk->pid) 713 netlink_overrun(sk); 714 sock_put(sk); 715 kfree_skb(skb); 716 return -EAGAIN; 717 } 718 719 __set_current_state(TASK_INTERRUPTIBLE); 720 add_wait_queue(&nlk->wait, &wait); 721 722 if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || 723 test_bit(0, &nlk->state)) && 724 !sock_flag(sk, SOCK_DEAD)) 725 timeo = schedule_timeout(timeo); 726 727 __set_current_state(TASK_RUNNING); 728 remove_wait_queue(&nlk->wait, &wait); 729 sock_put(sk); 730 731 if (signal_pending(current)) { 732 kfree_skb(skb); 733 return sock_intr_errno(timeo); 734 } 735 return 1; 736 } 737 skb_set_owner_r(skb, sk); 738 return 0; 739 } 740 741 int netlink_sendskb(struct sock *sk, struct sk_buff *skb, int protocol) 742 { 743 struct netlink_sock *nlk; 744 int len = skb->len; 745 746 nlk = nlk_sk(sk); 747 748 skb_queue_tail(&sk->sk_receive_queue, skb); 749 sk->sk_data_ready(sk, len); 750 sock_put(sk); 751 return len; 752 } 753 754 void netlink_detachskb(struct sock *sk, struct sk_buff *skb) 755 { 756 kfree_skb(skb); 757 sock_put(sk); 758 } 759 760 static inline struct sk_buff *netlink_trim(struct sk_buff *skb, 761 unsigned int __nocast allocation) 762 { 763 int delta; 764 765 skb_orphan(skb); 766 767 delta = skb->end - skb->tail; 768 if (delta * 2 < skb->truesize) 769 return skb; 770 771 if (skb_shared(skb)) { 772 struct sk_buff *nskb = skb_clone(skb, allocation); 773 if (!nskb) 774 return skb; 775 kfree_skb(skb); 776 skb = nskb; 777 } 778 779 if (!pskb_expand_head(skb, 0, -delta, allocation)) 780 skb->truesize -= delta; 781 782 return skb; 783 } 784 785 int netlink_unicast(struct sock *ssk, struct sk_buff *skb, u32 pid, int nonblock) 786 { 787 struct sock *sk; 788 int err; 789 long timeo; 790 791 skb = netlink_trim(skb, gfp_any()); 792 793 timeo = sock_sndtimeo(ssk, nonblock); 794 retry: 795 sk = netlink_getsockbypid(ssk, pid); 796 if (IS_ERR(sk)) { 797 kfree_skb(skb); 798 return PTR_ERR(sk); 799 } 800 err = netlink_attachskb(sk, skb, nonblock, timeo); 801 if (err == 1) 802 goto retry; 803 if (err) 804 return err; 805 806 return netlink_sendskb(sk, skb, ssk->sk_protocol); 807 } 808 809 static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) 810 { 811 struct netlink_sock *nlk = nlk_sk(sk); 812 813 if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && 814 !test_bit(0, &nlk->state)) { 815 skb_set_owner_r(skb, sk); 816 skb_queue_tail(&sk->sk_receive_queue, skb); 817 sk->sk_data_ready(sk, skb->len); 818 return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf; 819 } 820 return -1; 821 } 822 823 struct netlink_broadcast_data { 824 struct sock *exclude_sk; 825 u32 pid; 826 u32 group; 827 int failure; 828 int congested; 829 int delivered; 830 unsigned int allocation; 831 struct sk_buff *skb, *skb2; 832 }; 833 834 static inline int do_one_broadcast(struct sock *sk, 835 struct netlink_broadcast_data *p) 836 { 837 struct netlink_sock *nlk = nlk_sk(sk); 838 int val; 839 840 if (p->exclude_sk == sk) 841 goto out; 842 843 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || 844 !test_bit(p->group - 1, nlk->groups)) 845 goto out; 846 847 if (p->failure) { 848 netlink_overrun(sk); 849 goto out; 850 } 851 852 sock_hold(sk); 853 if (p->skb2 == NULL) { 854 if (skb_shared(p->skb)) { 855 p->skb2 = skb_clone(p->skb, p->allocation); 856 } else { 857 p->skb2 = skb_get(p->skb); 858 /* 859 * skb ownership may have been set when 860 * delivered to a previous socket. 861 */ 862 skb_orphan(p->skb2); 863 } 864 } 865 if (p->skb2 == NULL) { 866 netlink_overrun(sk); 867 /* Clone failed. Notify ALL listeners. */ 868 p->failure = 1; 869 } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { 870 netlink_overrun(sk); 871 } else { 872 p->congested |= val; 873 p->delivered = 1; 874 p->skb2 = NULL; 875 } 876 sock_put(sk); 877 878 out: 879 return 0; 880 } 881 882 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, 883 u32 group, unsigned int __nocast allocation) 884 { 885 struct netlink_broadcast_data info; 886 struct hlist_node *node; 887 struct sock *sk; 888 889 skb = netlink_trim(skb, allocation); 890 891 info.exclude_sk = ssk; 892 info.pid = pid; 893 info.group = group; 894 info.failure = 0; 895 info.congested = 0; 896 info.delivered = 0; 897 info.allocation = allocation; 898 info.skb = skb; 899 info.skb2 = NULL; 900 901 /* While we sleep in clone, do not allow to change socket list */ 902 903 netlink_lock_table(); 904 905 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) 906 do_one_broadcast(sk, &info); 907 908 kfree_skb(skb); 909 910 netlink_unlock_table(); 911 912 if (info.skb2) 913 kfree_skb(info.skb2); 914 915 if (info.delivered) { 916 if (info.congested && (allocation & __GFP_WAIT)) 917 yield(); 918 return 0; 919 } 920 if (info.failure) 921 return -ENOBUFS; 922 return -ESRCH; 923 } 924 925 struct netlink_set_err_data { 926 struct sock *exclude_sk; 927 u32 pid; 928 u32 group; 929 int code; 930 }; 931 932 static inline int do_one_set_err(struct sock *sk, 933 struct netlink_set_err_data *p) 934 { 935 struct netlink_sock *nlk = nlk_sk(sk); 936 937 if (sk == p->exclude_sk) 938 goto out; 939 940 if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups || 941 !test_bit(p->group - 1, nlk->groups)) 942 goto out; 943 944 sk->sk_err = p->code; 945 sk->sk_error_report(sk); 946 out: 947 return 0; 948 } 949 950 void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code) 951 { 952 struct netlink_set_err_data info; 953 struct hlist_node *node; 954 struct sock *sk; 955 956 info.exclude_sk = ssk; 957 info.pid = pid; 958 info.group = group; 959 info.code = code; 960 961 read_lock(&nl_table_lock); 962 963 sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list) 964 do_one_set_err(sk, &info); 965 966 read_unlock(&nl_table_lock); 967 } 968 969 static int netlink_setsockopt(struct socket *sock, int level, int optname, 970 char __user *optval, int optlen) 971 { 972 struct sock *sk = sock->sk; 973 struct netlink_sock *nlk = nlk_sk(sk); 974 int val = 0, err; 975 976 if (level != SOL_NETLINK) 977 return -ENOPROTOOPT; 978 979 if (optlen >= sizeof(int) && 980 get_user(val, (int __user *)optval)) 981 return -EFAULT; 982 983 switch (optname) { 984 case NETLINK_PKTINFO: 985 if (val) 986 nlk->flags |= NETLINK_RECV_PKTINFO; 987 else 988 nlk->flags &= ~NETLINK_RECV_PKTINFO; 989 err = 0; 990 break; 991 case NETLINK_ADD_MEMBERSHIP: 992 case NETLINK_DROP_MEMBERSHIP: { 993 unsigned int subscriptions; 994 int old, new = optname == NETLINK_ADD_MEMBERSHIP ? 1 : 0; 995 996 if (!netlink_capable(sock, NL_NONROOT_RECV)) 997 return -EPERM; 998 if (nlk->groups == NULL) { 999 err = netlink_alloc_groups(sk); 1000 if (err) 1001 return err; 1002 } 1003 if (!val || val - 1 >= nlk->ngroups) 1004 return -EINVAL; 1005 netlink_table_grab(); 1006 old = test_bit(val - 1, nlk->groups); 1007 subscriptions = nlk->subscriptions - old + new; 1008 if (new) 1009 __set_bit(val - 1, nlk->groups); 1010 else 1011 __clear_bit(val - 1, nlk->groups); 1012 netlink_update_subscriptions(sk, subscriptions); 1013 netlink_table_ungrab(); 1014 err = 0; 1015 break; 1016 } 1017 default: 1018 err = -ENOPROTOOPT; 1019 } 1020 return err; 1021 } 1022 1023 static int netlink_getsockopt(struct socket *sock, int level, int optname, 1024 char __user *optval, int __user *optlen) 1025 { 1026 struct sock *sk = sock->sk; 1027 struct netlink_sock *nlk = nlk_sk(sk); 1028 int len, val, err; 1029 1030 if (level != SOL_NETLINK) 1031 return -ENOPROTOOPT; 1032 1033 if (get_user(len, optlen)) 1034 return -EFAULT; 1035 if (len < 0) 1036 return -EINVAL; 1037 1038 switch (optname) { 1039 case NETLINK_PKTINFO: 1040 if (len < sizeof(int)) 1041 return -EINVAL; 1042 len = sizeof(int); 1043 val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0; 1044 put_user(len, optlen); 1045 put_user(val, optval); 1046 err = 0; 1047 break; 1048 default: 1049 err = -ENOPROTOOPT; 1050 } 1051 return err; 1052 } 1053 1054 static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) 1055 { 1056 struct nl_pktinfo info; 1057 1058 info.group = NETLINK_CB(skb).dst_group; 1059 put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); 1060 } 1061 1062 static inline void netlink_rcv_wake(struct sock *sk) 1063 { 1064 struct netlink_sock *nlk = nlk_sk(sk); 1065 1066 if (skb_queue_empty(&sk->sk_receive_queue)) 1067 clear_bit(0, &nlk->state); 1068 if (!test_bit(0, &nlk->state)) 1069 wake_up_interruptible(&nlk->wait); 1070 } 1071 1072 static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock, 1073 struct msghdr *msg, size_t len) 1074 { 1075 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1076 struct sock *sk = sock->sk; 1077 struct netlink_sock *nlk = nlk_sk(sk); 1078 struct sockaddr_nl *addr=msg->msg_name; 1079 u32 dst_pid; 1080 u32 dst_group; 1081 struct sk_buff *skb; 1082 int err; 1083 struct scm_cookie scm; 1084 1085 if (msg->msg_flags&MSG_OOB) 1086 return -EOPNOTSUPP; 1087 1088 if (NULL == siocb->scm) 1089 siocb->scm = &scm; 1090 err = scm_send(sock, msg, siocb->scm); 1091 if (err < 0) 1092 return err; 1093 1094 if (msg->msg_namelen) { 1095 if (addr->nl_family != AF_NETLINK) 1096 return -EINVAL; 1097 dst_pid = addr->nl_pid; 1098 dst_group = ffs(addr->nl_groups); 1099 if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND)) 1100 return -EPERM; 1101 } else { 1102 dst_pid = nlk->dst_pid; 1103 dst_group = nlk->dst_group; 1104 } 1105 1106 if (!nlk->pid) { 1107 err = netlink_autobind(sock); 1108 if (err) 1109 goto out; 1110 } 1111 1112 err = -EMSGSIZE; 1113 if (len > sk->sk_sndbuf - 32) 1114 goto out; 1115 err = -ENOBUFS; 1116 skb = alloc_skb(len, GFP_KERNEL); 1117 if (skb==NULL) 1118 goto out; 1119 1120 NETLINK_CB(skb).pid = nlk->pid; 1121 NETLINK_CB(skb).dst_pid = dst_pid; 1122 NETLINK_CB(skb).dst_group = dst_group; 1123 NETLINK_CB(skb).loginuid = audit_get_loginuid(current->audit_context); 1124 memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred)); 1125 1126 /* What can I do? Netlink is asynchronous, so that 1127 we will have to save current capabilities to 1128 check them, when this message will be delivered 1129 to corresponding kernel module. --ANK (980802) 1130 */ 1131 1132 err = -EFAULT; 1133 if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) { 1134 kfree_skb(skb); 1135 goto out; 1136 } 1137 1138 err = security_netlink_send(sk, skb); 1139 if (err) { 1140 kfree_skb(skb); 1141 goto out; 1142 } 1143 1144 if (dst_group) { 1145 atomic_inc(&skb->users); 1146 netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL); 1147 } 1148 err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT); 1149 1150 out: 1151 return err; 1152 } 1153 1154 static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock, 1155 struct msghdr *msg, size_t len, 1156 int flags) 1157 { 1158 struct sock_iocb *siocb = kiocb_to_siocb(kiocb); 1159 struct scm_cookie scm; 1160 struct sock *sk = sock->sk; 1161 struct netlink_sock *nlk = nlk_sk(sk); 1162 int noblock = flags&MSG_DONTWAIT; 1163 size_t copied; 1164 struct sk_buff *skb; 1165 int err; 1166 1167 if (flags&MSG_OOB) 1168 return -EOPNOTSUPP; 1169 1170 copied = 0; 1171 1172 skb = skb_recv_datagram(sk,flags,noblock,&err); 1173 if (skb==NULL) 1174 goto out; 1175 1176 msg->msg_namelen = 0; 1177 1178 copied = skb->len; 1179 if (len < copied) { 1180 msg->msg_flags |= MSG_TRUNC; 1181 copied = len; 1182 } 1183 1184 skb->h.raw = skb->data; 1185 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); 1186 1187 if (msg->msg_name) { 1188 struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name; 1189 addr->nl_family = AF_NETLINK; 1190 addr->nl_pad = 0; 1191 addr->nl_pid = NETLINK_CB(skb).pid; 1192 addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); 1193 msg->msg_namelen = sizeof(*addr); 1194 } 1195 1196 if (NULL == siocb->scm) { 1197 memset(&scm, 0, sizeof(scm)); 1198 siocb->scm = &scm; 1199 } 1200 siocb->scm->creds = *NETLINK_CREDS(skb); 1201 skb_free_datagram(sk, skb); 1202 1203 if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) 1204 netlink_dump(sk); 1205 1206 scm_recv(sock, msg, siocb->scm, flags); 1207 if (nlk->flags & NETLINK_RECV_PKTINFO) 1208 netlink_cmsg_recv_pktinfo(msg, skb); 1209 1210 out: 1211 netlink_rcv_wake(sk); 1212 return err ? : copied; 1213 } 1214 1215 static void netlink_data_ready(struct sock *sk, int len) 1216 { 1217 struct netlink_sock *nlk = nlk_sk(sk); 1218 1219 if (nlk->data_ready) 1220 nlk->data_ready(sk, len); 1221 netlink_rcv_wake(sk); 1222 } 1223 1224 /* 1225 * We export these functions to other modules. They provide a 1226 * complete set of kernel non-blocking support for message 1227 * queueing. 1228 */ 1229 1230 struct sock * 1231 netlink_kernel_create(int unit, unsigned int groups, 1232 void (*input)(struct sock *sk, int len), 1233 struct module *module) 1234 { 1235 struct socket *sock; 1236 struct sock *sk; 1237 struct netlink_sock *nlk; 1238 1239 if (!nl_table) 1240 return NULL; 1241 1242 if (unit<0 || unit>=MAX_LINKS) 1243 return NULL; 1244 1245 if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) 1246 return NULL; 1247 1248 if (__netlink_create(sock, unit) < 0) 1249 goto out_sock_release; 1250 1251 sk = sock->sk; 1252 sk->sk_data_ready = netlink_data_ready; 1253 if (input) 1254 nlk_sk(sk)->data_ready = input; 1255 1256 if (netlink_insert(sk, 0)) 1257 goto out_sock_release; 1258 1259 nlk = nlk_sk(sk); 1260 nlk->flags |= NETLINK_KERNEL_SOCKET; 1261 1262 netlink_table_grab(); 1263 nl_table[unit].groups = groups < 32 ? 32 : groups; 1264 nl_table[unit].module = module; 1265 nl_table[unit].registered = 1; 1266 netlink_table_ungrab(); 1267 1268 return sk; 1269 1270 out_sock_release: 1271 sock_release(sock); 1272 return NULL; 1273 } 1274 1275 void netlink_set_nonroot(int protocol, unsigned int flags) 1276 { 1277 if ((unsigned int)protocol < MAX_LINKS) 1278 nl_table[protocol].nl_nonroot = flags; 1279 } 1280 1281 static void netlink_destroy_callback(struct netlink_callback *cb) 1282 { 1283 if (cb->skb) 1284 kfree_skb(cb->skb); 1285 kfree(cb); 1286 } 1287 1288 /* 1289 * It looks a bit ugly. 1290 * It would be better to create kernel thread. 1291 */ 1292 1293 static int netlink_dump(struct sock *sk) 1294 { 1295 struct netlink_sock *nlk = nlk_sk(sk); 1296 struct netlink_callback *cb; 1297 struct sk_buff *skb; 1298 struct nlmsghdr *nlh; 1299 int len; 1300 1301 skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL); 1302 if (!skb) 1303 return -ENOBUFS; 1304 1305 spin_lock(&nlk->cb_lock); 1306 1307 cb = nlk->cb; 1308 if (cb == NULL) { 1309 spin_unlock(&nlk->cb_lock); 1310 kfree_skb(skb); 1311 return -EINVAL; 1312 } 1313 1314 len = cb->dump(skb, cb); 1315 1316 if (len > 0) { 1317 spin_unlock(&nlk->cb_lock); 1318 skb_queue_tail(&sk->sk_receive_queue, skb); 1319 sk->sk_data_ready(sk, len); 1320 return 0; 1321 } 1322 1323 nlh = NLMSG_NEW_ANSWER(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI); 1324 memcpy(NLMSG_DATA(nlh), &len, sizeof(len)); 1325 skb_queue_tail(&sk->sk_receive_queue, skb); 1326 sk->sk_data_ready(sk, skb->len); 1327 1328 cb->done(cb); 1329 nlk->cb = NULL; 1330 spin_unlock(&nlk->cb_lock); 1331 1332 netlink_destroy_callback(cb); 1333 return 0; 1334 1335 nlmsg_failure: 1336 return -ENOBUFS; 1337 } 1338 1339 int netlink_dump_start(struct sock *ssk, struct sk_buff *skb, 1340 struct nlmsghdr *nlh, 1341 int (*dump)(struct sk_buff *skb, struct netlink_callback*), 1342 int (*done)(struct netlink_callback*)) 1343 { 1344 struct netlink_callback *cb; 1345 struct sock *sk; 1346 struct netlink_sock *nlk; 1347 1348 cb = kmalloc(sizeof(*cb), GFP_KERNEL); 1349 if (cb == NULL) 1350 return -ENOBUFS; 1351 1352 memset(cb, 0, sizeof(*cb)); 1353 cb->dump = dump; 1354 cb->done = done; 1355 cb->nlh = nlh; 1356 atomic_inc(&skb->users); 1357 cb->skb = skb; 1358 1359 sk = netlink_lookup(ssk->sk_protocol, NETLINK_CB(skb).pid); 1360 if (sk == NULL) { 1361 netlink_destroy_callback(cb); 1362 return -ECONNREFUSED; 1363 } 1364 nlk = nlk_sk(sk); 1365 /* A dump is in progress... */ 1366 spin_lock(&nlk->cb_lock); 1367 if (nlk->cb) { 1368 spin_unlock(&nlk->cb_lock); 1369 netlink_destroy_callback(cb); 1370 sock_put(sk); 1371 return -EBUSY; 1372 } 1373 nlk->cb = cb; 1374 spin_unlock(&nlk->cb_lock); 1375 1376 netlink_dump(sk); 1377 sock_put(sk); 1378 return 0; 1379 } 1380 1381 void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) 1382 { 1383 struct sk_buff *skb; 1384 struct nlmsghdr *rep; 1385 struct nlmsgerr *errmsg; 1386 int size; 1387 1388 if (err == 0) 1389 size = NLMSG_SPACE(sizeof(struct nlmsgerr)); 1390 else 1391 size = NLMSG_SPACE(4 + NLMSG_ALIGN(nlh->nlmsg_len)); 1392 1393 skb = alloc_skb(size, GFP_KERNEL); 1394 if (!skb) { 1395 struct sock *sk; 1396 1397 sk = netlink_lookup(in_skb->sk->sk_protocol, 1398 NETLINK_CB(in_skb).pid); 1399 if (sk) { 1400 sk->sk_err = ENOBUFS; 1401 sk->sk_error_report(sk); 1402 sock_put(sk); 1403 } 1404 return; 1405 } 1406 1407 rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq, 1408 NLMSG_ERROR, sizeof(struct nlmsgerr), 0); 1409 errmsg = NLMSG_DATA(rep); 1410 errmsg->error = err; 1411 memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(struct nlmsghdr)); 1412 netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT); 1413 } 1414 1415 1416 #ifdef CONFIG_PROC_FS 1417 struct nl_seq_iter { 1418 int link; 1419 int hash_idx; 1420 }; 1421 1422 static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos) 1423 { 1424 struct nl_seq_iter *iter = seq->private; 1425 int i, j; 1426 struct sock *s; 1427 struct hlist_node *node; 1428 loff_t off = 0; 1429 1430 for (i=0; i<MAX_LINKS; i++) { 1431 struct nl_pid_hash *hash = &nl_table[i].hash; 1432 1433 for (j = 0; j <= hash->mask; j++) { 1434 sk_for_each(s, node, &hash->table[j]) { 1435 if (off == pos) { 1436 iter->link = i; 1437 iter->hash_idx = j; 1438 return s; 1439 } 1440 ++off; 1441 } 1442 } 1443 } 1444 return NULL; 1445 } 1446 1447 static void *netlink_seq_start(struct seq_file *seq, loff_t *pos) 1448 { 1449 read_lock(&nl_table_lock); 1450 return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN; 1451 } 1452 1453 static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) 1454 { 1455 struct sock *s; 1456 struct nl_seq_iter *iter; 1457 int i, j; 1458 1459 ++*pos; 1460 1461 if (v == SEQ_START_TOKEN) 1462 return netlink_seq_socket_idx(seq, 0); 1463 1464 s = sk_next(v); 1465 if (s) 1466 return s; 1467 1468 iter = seq->private; 1469 i = iter->link; 1470 j = iter->hash_idx + 1; 1471 1472 do { 1473 struct nl_pid_hash *hash = &nl_table[i].hash; 1474 1475 for (; j <= hash->mask; j++) { 1476 s = sk_head(&hash->table[j]); 1477 if (s) { 1478 iter->link = i; 1479 iter->hash_idx = j; 1480 return s; 1481 } 1482 } 1483 1484 j = 0; 1485 } while (++i < MAX_LINKS); 1486 1487 return NULL; 1488 } 1489 1490 static void netlink_seq_stop(struct seq_file *seq, void *v) 1491 { 1492 read_unlock(&nl_table_lock); 1493 } 1494 1495 1496 static int netlink_seq_show(struct seq_file *seq, void *v) 1497 { 1498 if (v == SEQ_START_TOKEN) 1499 seq_puts(seq, 1500 "sk Eth Pid Groups " 1501 "Rmem Wmem Dump Locks\n"); 1502 else { 1503 struct sock *s = v; 1504 struct netlink_sock *nlk = nlk_sk(s); 1505 1506 seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n", 1507 s, 1508 s->sk_protocol, 1509 nlk->pid, 1510 nlk->groups ? (u32)nlk->groups[0] : 0, 1511 atomic_read(&s->sk_rmem_alloc), 1512 atomic_read(&s->sk_wmem_alloc), 1513 nlk->cb, 1514 atomic_read(&s->sk_refcnt) 1515 ); 1516 1517 } 1518 return 0; 1519 } 1520 1521 static struct seq_operations netlink_seq_ops = { 1522 .start = netlink_seq_start, 1523 .next = netlink_seq_next, 1524 .stop = netlink_seq_stop, 1525 .show = netlink_seq_show, 1526 }; 1527 1528 1529 static int netlink_seq_open(struct inode *inode, struct file *file) 1530 { 1531 struct seq_file *seq; 1532 struct nl_seq_iter *iter; 1533 int err; 1534 1535 iter = kmalloc(sizeof(*iter), GFP_KERNEL); 1536 if (!iter) 1537 return -ENOMEM; 1538 1539 err = seq_open(file, &netlink_seq_ops); 1540 if (err) { 1541 kfree(iter); 1542 return err; 1543 } 1544 1545 memset(iter, 0, sizeof(*iter)); 1546 seq = file->private_data; 1547 seq->private = iter; 1548 return 0; 1549 } 1550 1551 static struct file_operations netlink_seq_fops = { 1552 .owner = THIS_MODULE, 1553 .open = netlink_seq_open, 1554 .read = seq_read, 1555 .llseek = seq_lseek, 1556 .release = seq_release_private, 1557 }; 1558 1559 #endif 1560 1561 int netlink_register_notifier(struct notifier_block *nb) 1562 { 1563 return notifier_chain_register(&netlink_chain, nb); 1564 } 1565 1566 int netlink_unregister_notifier(struct notifier_block *nb) 1567 { 1568 return notifier_chain_unregister(&netlink_chain, nb); 1569 } 1570 1571 static struct proto_ops netlink_ops = { 1572 .family = PF_NETLINK, 1573 .owner = THIS_MODULE, 1574 .release = netlink_release, 1575 .bind = netlink_bind, 1576 .connect = netlink_connect, 1577 .socketpair = sock_no_socketpair, 1578 .accept = sock_no_accept, 1579 .getname = netlink_getname, 1580 .poll = datagram_poll, 1581 .ioctl = sock_no_ioctl, 1582 .listen = sock_no_listen, 1583 .shutdown = sock_no_shutdown, 1584 .setsockopt = netlink_setsockopt, 1585 .getsockopt = netlink_getsockopt, 1586 .sendmsg = netlink_sendmsg, 1587 .recvmsg = netlink_recvmsg, 1588 .mmap = sock_no_mmap, 1589 .sendpage = sock_no_sendpage, 1590 }; 1591 1592 static struct net_proto_family netlink_family_ops = { 1593 .family = PF_NETLINK, 1594 .create = netlink_create, 1595 .owner = THIS_MODULE, /* for consistency 8) */ 1596 }; 1597 1598 extern void netlink_skb_parms_too_large(void); 1599 1600 static int __init netlink_proto_init(void) 1601 { 1602 struct sk_buff *dummy_skb; 1603 int i; 1604 unsigned long max; 1605 unsigned int order; 1606 int err = proto_register(&netlink_proto, 0); 1607 1608 if (err != 0) 1609 goto out; 1610 1611 if (sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb)) 1612 netlink_skb_parms_too_large(); 1613 1614 nl_table = kmalloc(sizeof(*nl_table) * MAX_LINKS, GFP_KERNEL); 1615 if (!nl_table) { 1616 enomem: 1617 printk(KERN_CRIT "netlink_init: Cannot allocate nl_table\n"); 1618 return -ENOMEM; 1619 } 1620 1621 memset(nl_table, 0, sizeof(*nl_table) * MAX_LINKS); 1622 1623 if (num_physpages >= (128 * 1024)) 1624 max = num_physpages >> (21 - PAGE_SHIFT); 1625 else 1626 max = num_physpages >> (23 - PAGE_SHIFT); 1627 1628 order = get_bitmask_order(max) - 1 + PAGE_SHIFT; 1629 max = (1UL << order) / sizeof(struct hlist_head); 1630 order = get_bitmask_order(max > UINT_MAX ? UINT_MAX : max) - 1; 1631 1632 for (i = 0; i < MAX_LINKS; i++) { 1633 struct nl_pid_hash *hash = &nl_table[i].hash; 1634 1635 hash->table = nl_pid_hash_alloc(1 * sizeof(*hash->table)); 1636 if (!hash->table) { 1637 while (i-- > 0) 1638 nl_pid_hash_free(nl_table[i].hash.table, 1639 1 * sizeof(*hash->table)); 1640 kfree(nl_table); 1641 goto enomem; 1642 } 1643 memset(hash->table, 0, 1 * sizeof(*hash->table)); 1644 hash->max_shift = order; 1645 hash->shift = 0; 1646 hash->mask = 0; 1647 hash->rehash_time = jiffies; 1648 } 1649 1650 sock_register(&netlink_family_ops); 1651 #ifdef CONFIG_PROC_FS 1652 proc_net_fops_create("netlink", 0, &netlink_seq_fops); 1653 #endif 1654 /* The netlink device handler may be needed early. */ 1655 rtnetlink_init(); 1656 out: 1657 return err; 1658 } 1659 1660 core_initcall(netlink_proto_init); 1661 1662 EXPORT_SYMBOL(netlink_ack); 1663 EXPORT_SYMBOL(netlink_broadcast); 1664 EXPORT_SYMBOL(netlink_dump_start); 1665 EXPORT_SYMBOL(netlink_kernel_create); 1666 EXPORT_SYMBOL(netlink_register_notifier); 1667 EXPORT_SYMBOL(netlink_set_err); 1668 EXPORT_SYMBOL(netlink_set_nonroot); 1669 EXPORT_SYMBOL(netlink_unicast); 1670 EXPORT_SYMBOL(netlink_unregister_notifier); 1671 1672