Harald Welte | 7af4cc3 | 2005-08-09 19:44:15 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * This is a module which is used for queueing packets and communicating with |
| 3 | * userspace via nfetlink. |
| 4 | * |
| 5 | * (C) 2005 by Harald Welte <laforge@netfilter.org> |
| 6 | * |
| 7 | * Based on the old ipv4-only ip_queue.c: |
| 8 | * (C) 2000-2002 James Morris <jmorris@intercode.com.au> |
| 9 | * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org> |
| 10 | * |
| 11 | * This program is free software; you can redistribute it and/or modify |
| 12 | * it under the terms of the GNU General Public License version 2 as |
| 13 | * published by the Free Software Foundation. |
| 14 | * |
| 15 | */ |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/skbuff.h> |
| 18 | #include <linux/init.h> |
| 19 | #include <linux/spinlock.h> |
| 20 | #include <linux/notifier.h> |
| 21 | #include <linux/netdevice.h> |
| 22 | #include <linux/netfilter.h> |
| 23 | #include <linux/netfilter_ipv4.h> |
| 24 | #include <linux/netfilter_ipv6.h> |
| 25 | #include <linux/netfilter/nfnetlink.h> |
| 26 | #include <linux/netfilter/nfnetlink_queue.h> |
| 27 | #include <linux/list.h> |
| 28 | #include <net/sock.h> |
| 29 | |
| 30 | #include <asm/atomic.h> |
| 31 | |
| 32 | #define NFQNL_QMAX_DEFAULT 1024 |
| 33 | |
| 34 | #if 0 |
| 35 | #define QDEBUG(x, args ...) printk(KERN_DEBUG "%s(%d):%s(): " x, \ |
| 36 | __FILE__, __LINE__, __FUNCTION__, \ |
| 37 | ## args) |
| 38 | #else |
| 39 | #define QDEBUG(x, ...) |
| 40 | #endif |
| 41 | |
| 42 | struct nfqnl_queue_entry { |
| 43 | struct list_head list; |
| 44 | struct nf_info *info; |
| 45 | struct sk_buff *skb; |
| 46 | unsigned int id; |
| 47 | }; |
| 48 | |
| 49 | struct nfqnl_instance { |
| 50 | struct hlist_node hlist; /* global list of queues */ |
| 51 | |
| 52 | int peer_pid; |
| 53 | unsigned int queue_maxlen; |
| 54 | unsigned int copy_range; |
| 55 | unsigned int queue_total; |
| 56 | unsigned int queue_dropped; |
| 57 | unsigned int queue_user_dropped; |
| 58 | |
| 59 | atomic_t id_sequence; /* 'sequence' of pkt ids */ |
| 60 | |
| 61 | u_int16_t queue_num; /* number of this queue */ |
| 62 | u_int8_t copy_mode; |
| 63 | |
| 64 | spinlock_t lock; |
| 65 | |
| 66 | struct list_head queue_list; /* packets in queue */ |
| 67 | }; |
| 68 | |
| 69 | typedef int (*nfqnl_cmpfn)(struct nfqnl_queue_entry *, unsigned long); |
| 70 | |
| 71 | static DEFINE_RWLOCK(instances_lock); |
| 72 | |
| 73 | u_int64_t htonll(u_int64_t in) |
| 74 | { |
| 75 | u_int64_t out; |
| 76 | int i; |
| 77 | |
| 78 | for (i = 0; i < sizeof(u_int64_t); i++) |
| 79 | ((u_int8_t *)&out)[sizeof(u_int64_t)-1] = ((u_int8_t *)&in)[i]; |
| 80 | |
| 81 | return out; |
| 82 | } |
| 83 | |
| 84 | #define INSTANCE_BUCKETS 16 |
| 85 | static struct hlist_head instance_table[INSTANCE_BUCKETS]; |
| 86 | |
| 87 | static inline u_int8_t instance_hashfn(u_int16_t queue_num) |
| 88 | { |
| 89 | return ((queue_num >> 8) | queue_num) % INSTANCE_BUCKETS; |
| 90 | } |
| 91 | |
| 92 | static struct nfqnl_instance * |
| 93 | __instance_lookup(u_int16_t queue_num) |
| 94 | { |
| 95 | struct hlist_head *head; |
| 96 | struct hlist_node *pos; |
| 97 | struct nfqnl_instance *inst; |
| 98 | |
| 99 | head = &instance_table[instance_hashfn(queue_num)]; |
| 100 | hlist_for_each_entry(inst, pos, head, hlist) { |
| 101 | if (inst->queue_num == queue_num) |
| 102 | return inst; |
| 103 | } |
| 104 | return NULL; |
| 105 | } |
| 106 | |
| 107 | static struct nfqnl_instance * |
| 108 | instance_lookup(u_int16_t queue_num) |
| 109 | { |
| 110 | struct nfqnl_instance *inst; |
| 111 | |
| 112 | read_lock_bh(&instances_lock); |
| 113 | inst = __instance_lookup(queue_num); |
| 114 | read_unlock_bh(&instances_lock); |
| 115 | |
| 116 | return inst; |
| 117 | } |
| 118 | |
| 119 | static struct nfqnl_instance * |
| 120 | instance_create(u_int16_t queue_num, int pid) |
| 121 | { |
| 122 | struct nfqnl_instance *inst; |
| 123 | |
| 124 | QDEBUG("entering for queue_num=%u, pid=%d\n", queue_num, pid); |
| 125 | |
| 126 | write_lock_bh(&instances_lock); |
| 127 | if (__instance_lookup(queue_num)) { |
| 128 | inst = NULL; |
| 129 | QDEBUG("aborting, instance already exists\n"); |
| 130 | goto out_unlock; |
| 131 | } |
| 132 | |
| 133 | inst = kmalloc(sizeof(*inst), GFP_ATOMIC); |
| 134 | if (!inst) |
| 135 | goto out_unlock; |
| 136 | |
| 137 | memset(inst, 0, sizeof(*inst)); |
| 138 | inst->queue_num = queue_num; |
| 139 | inst->peer_pid = pid; |
| 140 | inst->queue_maxlen = NFQNL_QMAX_DEFAULT; |
| 141 | inst->copy_range = 0xfffff; |
| 142 | inst->copy_mode = NFQNL_COPY_NONE; |
| 143 | atomic_set(&inst->id_sequence, 0); |
| 144 | inst->lock = SPIN_LOCK_UNLOCKED; |
| 145 | INIT_LIST_HEAD(&inst->queue_list); |
| 146 | |
| 147 | if (!try_module_get(THIS_MODULE)) |
| 148 | goto out_free; |
| 149 | |
| 150 | hlist_add_head(&inst->hlist, |
| 151 | &instance_table[instance_hashfn(queue_num)]); |
| 152 | |
| 153 | write_unlock_bh(&instances_lock); |
| 154 | |
| 155 | QDEBUG("successfully created new instance\n"); |
| 156 | |
| 157 | return inst; |
| 158 | |
| 159 | out_free: |
| 160 | kfree(inst); |
| 161 | out_unlock: |
| 162 | write_unlock_bh(&instances_lock); |
| 163 | return NULL; |
| 164 | } |
| 165 | |
| 166 | static void nfqnl_flush(struct nfqnl_instance *queue, int verdict); |
| 167 | |
| 168 | static void |
| 169 | _instance_destroy2(struct nfqnl_instance *inst, int lock) |
| 170 | { |
| 171 | /* first pull it out of the global list */ |
| 172 | if (lock) |
| 173 | write_lock_bh(&instances_lock); |
| 174 | |
| 175 | QDEBUG("removing instance %p (queuenum=%u) from hash\n", |
| 176 | inst, inst->queue_num); |
| 177 | hlist_del(&inst->hlist); |
| 178 | |
| 179 | if (lock) |
| 180 | write_unlock_bh(&instances_lock); |
| 181 | |
| 182 | /* then flush all pending skbs from the queue */ |
| 183 | nfqnl_flush(inst, NF_DROP); |
| 184 | |
| 185 | /* and finally free the data structure */ |
| 186 | kfree(inst); |
| 187 | |
| 188 | module_put(THIS_MODULE); |
| 189 | } |
| 190 | |
| 191 | static inline void |
| 192 | __instance_destroy(struct nfqnl_instance *inst) |
| 193 | { |
| 194 | _instance_destroy2(inst, 0); |
| 195 | } |
| 196 | |
| 197 | static inline void |
| 198 | instance_destroy(struct nfqnl_instance *inst) |
| 199 | { |
| 200 | _instance_destroy2(inst, 1); |
| 201 | } |
| 202 | |
| 203 | |
| 204 | |
| 205 | static void |
| 206 | issue_verdict(struct nfqnl_queue_entry *entry, int verdict) |
| 207 | { |
| 208 | QDEBUG("entering for entry %p, verdict %u\n", entry, verdict); |
| 209 | |
| 210 | /* TCP input path (and probably other bits) assume to be called |
| 211 | * from softirq context, not from syscall, like issue_verdict is |
| 212 | * called. TCP input path deadlocks with locks taken from timer |
| 213 | * softirq, e.g. We therefore emulate this by local_bh_disable() */ |
| 214 | |
| 215 | local_bh_disable(); |
| 216 | nf_reinject(entry->skb, entry->info, verdict); |
| 217 | local_bh_enable(); |
| 218 | |
| 219 | kfree(entry); |
| 220 | } |
| 221 | |
| 222 | static inline void |
| 223 | __enqueue_entry(struct nfqnl_instance *queue, |
| 224 | struct nfqnl_queue_entry *entry) |
| 225 | { |
| 226 | list_add(&entry->list, &queue->queue_list); |
| 227 | queue->queue_total++; |
| 228 | } |
| 229 | |
| 230 | /* |
| 231 | * Find and return a queued entry matched by cmpfn, or return the last |
| 232 | * entry if cmpfn is NULL. |
| 233 | */ |
| 234 | static inline struct nfqnl_queue_entry * |
| 235 | __find_entry(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn, |
| 236 | unsigned long data) |
| 237 | { |
| 238 | struct list_head *p; |
| 239 | |
| 240 | list_for_each_prev(p, &queue->queue_list) { |
| 241 | struct nfqnl_queue_entry *entry = (struct nfqnl_queue_entry *)p; |
| 242 | |
| 243 | if (!cmpfn || cmpfn(entry, data)) |
| 244 | return entry; |
| 245 | } |
| 246 | return NULL; |
| 247 | } |
| 248 | |
| 249 | static inline void |
| 250 | __dequeue_entry(struct nfqnl_instance *q, struct nfqnl_queue_entry *entry) |
| 251 | { |
| 252 | list_del(&entry->list); |
| 253 | q->queue_total--; |
| 254 | } |
| 255 | |
| 256 | static inline struct nfqnl_queue_entry * |
| 257 | __find_dequeue_entry(struct nfqnl_instance *queue, |
| 258 | nfqnl_cmpfn cmpfn, unsigned long data) |
| 259 | { |
| 260 | struct nfqnl_queue_entry *entry; |
| 261 | |
| 262 | entry = __find_entry(queue, cmpfn, data); |
| 263 | if (entry == NULL) |
| 264 | return NULL; |
| 265 | |
| 266 | __dequeue_entry(queue, entry); |
| 267 | return entry; |
| 268 | } |
| 269 | |
| 270 | |
| 271 | static inline void |
| 272 | __nfqnl_flush(struct nfqnl_instance *queue, int verdict) |
| 273 | { |
| 274 | struct nfqnl_queue_entry *entry; |
| 275 | |
| 276 | while ((entry = __find_dequeue_entry(queue, NULL, 0))) |
| 277 | issue_verdict(entry, verdict); |
| 278 | } |
| 279 | |
| 280 | static inline int |
| 281 | __nfqnl_set_mode(struct nfqnl_instance *queue, |
| 282 | unsigned char mode, unsigned int range) |
| 283 | { |
| 284 | int status = 0; |
| 285 | |
| 286 | switch (mode) { |
| 287 | case NFQNL_COPY_NONE: |
| 288 | case NFQNL_COPY_META: |
| 289 | queue->copy_mode = mode; |
| 290 | queue->copy_range = 0; |
| 291 | break; |
| 292 | |
| 293 | case NFQNL_COPY_PACKET: |
| 294 | queue->copy_mode = mode; |
| 295 | /* we're using struct nfattr which has 16bit nfa_len */ |
| 296 | if (range > 0xffff) |
| 297 | queue->copy_range = 0xffff; |
| 298 | else |
| 299 | queue->copy_range = range; |
| 300 | break; |
| 301 | |
| 302 | default: |
| 303 | status = -EINVAL; |
| 304 | |
| 305 | } |
| 306 | return status; |
| 307 | } |
| 308 | |
| 309 | static struct nfqnl_queue_entry * |
| 310 | find_dequeue_entry(struct nfqnl_instance *queue, |
| 311 | nfqnl_cmpfn cmpfn, unsigned long data) |
| 312 | { |
| 313 | struct nfqnl_queue_entry *entry; |
| 314 | |
| 315 | spin_lock_bh(&queue->lock); |
| 316 | entry = __find_dequeue_entry(queue, cmpfn, data); |
| 317 | spin_unlock_bh(&queue->lock); |
| 318 | |
| 319 | return entry; |
| 320 | } |
| 321 | |
| 322 | static void |
| 323 | nfqnl_flush(struct nfqnl_instance *queue, int verdict) |
| 324 | { |
| 325 | spin_lock_bh(&queue->lock); |
| 326 | __nfqnl_flush(queue, verdict); |
| 327 | spin_unlock_bh(&queue->lock); |
| 328 | } |
| 329 | |
| 330 | static struct sk_buff * |
| 331 | nfqnl_build_packet_message(struct nfqnl_instance *queue, |
| 332 | struct nfqnl_queue_entry *entry, int *errp) |
| 333 | { |
| 334 | unsigned char *old_tail; |
| 335 | size_t size; |
| 336 | size_t data_len = 0; |
| 337 | struct sk_buff *skb; |
| 338 | struct nfqnl_msg_packet_hdr pmsg; |
| 339 | struct nlmsghdr *nlh; |
| 340 | struct nfgenmsg *nfmsg; |
| 341 | unsigned int tmp_uint; |
| 342 | |
| 343 | QDEBUG("entered\n"); |
| 344 | |
| 345 | /* all macros expand to constant values at compile time */ |
| 346 | size = NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hdr)) |
| 347 | + NLMSG_SPACE(sizeof(u_int32_t)) /* ifindex */ |
| 348 | + NLMSG_SPACE(sizeof(u_int32_t)) /* ifindex */ |
| 349 | + NLMSG_SPACE(sizeof(u_int32_t)) /* mark */ |
| 350 | + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_hw)) |
| 351 | + NLMSG_SPACE(sizeof(struct nfqnl_msg_packet_timestamp)); |
| 352 | |
| 353 | spin_lock_bh(&queue->lock); |
| 354 | |
| 355 | switch (queue->copy_mode) { |
| 356 | case NFQNL_COPY_META: |
| 357 | case NFQNL_COPY_NONE: |
| 358 | data_len = 0; |
| 359 | break; |
| 360 | |
| 361 | case NFQNL_COPY_PACKET: |
| 362 | if (queue->copy_range == 0 |
| 363 | || queue->copy_range > entry->skb->len) |
| 364 | data_len = entry->skb->len; |
| 365 | else |
| 366 | data_len = queue->copy_range; |
| 367 | |
| 368 | size += NLMSG_SPACE(data_len); |
| 369 | break; |
| 370 | |
| 371 | default: |
| 372 | *errp = -EINVAL; |
| 373 | spin_unlock_bh(&queue->lock); |
| 374 | return NULL; |
| 375 | } |
| 376 | |
| 377 | spin_unlock_bh(&queue->lock); |
| 378 | |
| 379 | skb = alloc_skb(size, GFP_ATOMIC); |
| 380 | if (!skb) |
| 381 | goto nlmsg_failure; |
| 382 | |
| 383 | old_tail= skb->tail; |
| 384 | nlh = NLMSG_PUT(skb, 0, 0, |
| 385 | NFNL_SUBSYS_QUEUE << 8 | NFQNL_MSG_PACKET, |
| 386 | sizeof(struct nfgenmsg)); |
| 387 | nfmsg = NLMSG_DATA(nlh); |
| 388 | nfmsg->nfgen_family = entry->info->pf; |
| 389 | nfmsg->version = NFNETLINK_V0; |
| 390 | nfmsg->res_id = htons(queue->queue_num); |
| 391 | |
| 392 | pmsg.packet_id = htonl(entry->id); |
| 393 | pmsg.hw_protocol = htons(entry->skb->protocol); |
| 394 | pmsg.hook = entry->info->hook; |
| 395 | |
| 396 | NFA_PUT(skb, NFQA_PACKET_HDR, sizeof(pmsg), &pmsg); |
| 397 | |
| 398 | if (entry->info->indev) { |
| 399 | tmp_uint = htonl(entry->info->indev->ifindex); |
| 400 | NFA_PUT(skb, NFQA_IFINDEX_INDEV, sizeof(tmp_uint), &tmp_uint); |
| 401 | } |
| 402 | |
| 403 | if (entry->info->outdev) { |
| 404 | tmp_uint = htonl(entry->info->outdev->ifindex); |
| 405 | NFA_PUT(skb, NFQA_IFINDEX_OUTDEV, sizeof(tmp_uint), &tmp_uint); |
| 406 | } |
| 407 | |
| 408 | if (entry->skb->nfmark) { |
| 409 | tmp_uint = htonl(entry->skb->nfmark); |
| 410 | NFA_PUT(skb, NFQA_MARK, sizeof(u_int32_t), &tmp_uint); |
| 411 | } |
| 412 | |
| 413 | if (entry->info->indev && entry->skb->dev |
| 414 | && entry->skb->dev->hard_header_parse) { |
| 415 | struct nfqnl_msg_packet_hw phw; |
| 416 | |
| 417 | phw.hw_addrlen = |
| 418 | entry->skb->dev->hard_header_parse(entry->skb, |
| 419 | phw.hw_addr); |
| 420 | phw.hw_addrlen = htons(phw.hw_addrlen); |
| 421 | NFA_PUT(skb, NFQA_HWADDR, sizeof(phw), &phw); |
| 422 | } |
| 423 | |
| 424 | if (entry->skb->stamp.tv_sec) { |
| 425 | struct nfqnl_msg_packet_timestamp ts; |
| 426 | |
| 427 | ts.sec = htonll(entry->skb->stamp.tv_sec); |
| 428 | ts.usec = htonll(entry->skb->stamp.tv_usec); |
| 429 | |
| 430 | NFA_PUT(skb, NFQA_TIMESTAMP, sizeof(ts), &ts); |
| 431 | } |
| 432 | |
| 433 | if (data_len) { |
| 434 | struct nfattr *nfa; |
| 435 | int size = NFA_LENGTH(data_len); |
| 436 | |
| 437 | if (skb_tailroom(skb) < (int)NFA_SPACE(data_len)) { |
| 438 | printk(KERN_WARNING "nf_queue: no tailroom!\n"); |
| 439 | goto nlmsg_failure; |
| 440 | } |
| 441 | |
| 442 | nfa = (struct nfattr *)skb_put(skb, NFA_ALIGN(size)); |
| 443 | nfa->nfa_type = NFQA_PAYLOAD; |
| 444 | nfa->nfa_len = size; |
| 445 | |
| 446 | if (skb_copy_bits(entry->skb, 0, NFA_DATA(nfa), data_len)) |
| 447 | BUG(); |
| 448 | } |
| 449 | |
| 450 | nlh->nlmsg_len = skb->tail - old_tail; |
| 451 | return skb; |
| 452 | |
| 453 | nlmsg_failure: |
| 454 | nfattr_failure: |
| 455 | if (skb) |
| 456 | kfree_skb(skb); |
| 457 | *errp = -EINVAL; |
| 458 | if (net_ratelimit()) |
| 459 | printk(KERN_ERR "nf_queue: error creating packet message\n"); |
| 460 | return NULL; |
| 461 | } |
| 462 | |
| 463 | static int |
| 464 | nfqnl_enqueue_packet(struct sk_buff *skb, struct nf_info *info, |
| 465 | unsigned int queuenum, void *data) |
| 466 | { |
| 467 | int status = -EINVAL; |
| 468 | struct sk_buff *nskb; |
| 469 | struct nfqnl_instance *queue; |
| 470 | struct nfqnl_queue_entry *entry; |
| 471 | |
| 472 | QDEBUG("entered\n"); |
| 473 | |
| 474 | queue = instance_lookup(queuenum); |
| 475 | if (!queue) { |
| 476 | QDEBUG("no queue instance matching\n"); |
| 477 | return -EINVAL; |
| 478 | } |
| 479 | |
| 480 | if (queue->copy_mode == NFQNL_COPY_NONE) { |
| 481 | QDEBUG("mode COPY_NONE, aborting\n"); |
| 482 | return -EAGAIN; |
| 483 | } |
| 484 | |
| 485 | entry = kmalloc(sizeof(*entry), GFP_ATOMIC); |
| 486 | if (entry == NULL) { |
| 487 | if (net_ratelimit()) |
| 488 | printk(KERN_ERR |
| 489 | "nf_queue: OOM in nfqnl_enqueue_packet()\n"); |
| 490 | return -ENOMEM; |
| 491 | } |
| 492 | |
| 493 | entry->info = info; |
| 494 | entry->skb = skb; |
| 495 | entry->id = atomic_inc_return(&queue->id_sequence); |
| 496 | |
| 497 | nskb = nfqnl_build_packet_message(queue, entry, &status); |
| 498 | if (nskb == NULL) |
| 499 | goto err_out_free; |
| 500 | |
| 501 | spin_lock_bh(&queue->lock); |
| 502 | |
| 503 | if (!queue->peer_pid) |
| 504 | goto err_out_free_nskb; |
| 505 | |
| 506 | if (queue->queue_total >= queue->queue_maxlen) { |
| 507 | queue->queue_dropped++; |
| 508 | status = -ENOSPC; |
| 509 | if (net_ratelimit()) |
| 510 | printk(KERN_WARNING "ip_queue: full at %d entries, " |
| 511 | "dropping packets(s). Dropped: %d\n", |
| 512 | queue->queue_total, queue->queue_dropped); |
| 513 | goto err_out_free_nskb; |
| 514 | } |
| 515 | |
| 516 | /* nfnetlink_unicast will either free the nskb or add it to a socket */ |
| 517 | status = nfnetlink_unicast(nskb, queue->peer_pid, MSG_DONTWAIT); |
| 518 | if (status < 0) { |
| 519 | queue->queue_user_dropped++; |
| 520 | goto err_out_unlock; |
| 521 | } |
| 522 | |
| 523 | __enqueue_entry(queue, entry); |
| 524 | |
| 525 | spin_unlock_bh(&queue->lock); |
| 526 | return status; |
| 527 | |
| 528 | err_out_free_nskb: |
| 529 | kfree_skb(nskb); |
| 530 | |
| 531 | err_out_unlock: |
| 532 | spin_unlock_bh(&queue->lock); |
| 533 | |
| 534 | err_out_free: |
| 535 | kfree(entry); |
| 536 | return status; |
| 537 | } |
| 538 | |
| 539 | static int |
| 540 | nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e) |
| 541 | { |
| 542 | int diff; |
| 543 | |
| 544 | diff = data_len - e->skb->len; |
| 545 | if (diff < 0) |
| 546 | skb_trim(e->skb, data_len); |
| 547 | else if (diff > 0) { |
| 548 | if (data_len > 0xFFFF) |
| 549 | return -EINVAL; |
| 550 | if (diff > skb_tailroom(e->skb)) { |
| 551 | struct sk_buff *newskb; |
| 552 | |
| 553 | newskb = skb_copy_expand(e->skb, |
| 554 | skb_headroom(e->skb), |
| 555 | diff, |
| 556 | GFP_ATOMIC); |
| 557 | if (newskb == NULL) { |
| 558 | printk(KERN_WARNING "ip_queue: OOM " |
| 559 | "in mangle, dropping packet\n"); |
| 560 | return -ENOMEM; |
| 561 | } |
| 562 | if (e->skb->sk) |
| 563 | skb_set_owner_w(newskb, e->skb->sk); |
| 564 | kfree_skb(e->skb); |
| 565 | e->skb = newskb; |
| 566 | } |
| 567 | skb_put(e->skb, diff); |
| 568 | } |
| 569 | if (!skb_make_writable(&e->skb, data_len)) |
| 570 | return -ENOMEM; |
| 571 | memcpy(e->skb->data, data, data_len); |
| 572 | |
| 573 | return 0; |
| 574 | } |
| 575 | |
| 576 | static inline int |
| 577 | id_cmp(struct nfqnl_queue_entry *e, unsigned long id) |
| 578 | { |
| 579 | return (id == e->id); |
| 580 | } |
| 581 | |
| 582 | static int |
| 583 | nfqnl_set_mode(struct nfqnl_instance *queue, |
| 584 | unsigned char mode, unsigned int range) |
| 585 | { |
| 586 | int status; |
| 587 | |
| 588 | spin_lock_bh(&queue->lock); |
| 589 | status = __nfqnl_set_mode(queue, mode, range); |
| 590 | spin_unlock_bh(&queue->lock); |
| 591 | |
| 592 | return status; |
| 593 | } |
| 594 | |
| 595 | static int |
| 596 | dev_cmp(struct nfqnl_queue_entry *entry, unsigned long ifindex) |
| 597 | { |
| 598 | if (entry->info->indev) |
| 599 | if (entry->info->indev->ifindex == ifindex) |
| 600 | return 1; |
| 601 | |
| 602 | if (entry->info->outdev) |
| 603 | if (entry->info->outdev->ifindex == ifindex) |
| 604 | return 1; |
| 605 | |
| 606 | return 0; |
| 607 | } |
| 608 | |
| 609 | /* drop all packets with either indev or outdev == ifindex from all queue |
| 610 | * instances */ |
| 611 | static void |
| 612 | nfqnl_dev_drop(int ifindex) |
| 613 | { |
| 614 | int i; |
| 615 | |
| 616 | QDEBUG("entering for ifindex %u\n", ifindex); |
| 617 | |
| 618 | /* this only looks like we have to hold the readlock for a way too long |
| 619 | * time, issue_verdict(), nf_reinject(), ... - but we always only |
| 620 | * issue NF_DROP, which is processed directly in nf_reinject() */ |
| 621 | read_lock_bh(&instances_lock); |
| 622 | |
| 623 | for (i = 0; i < INSTANCE_BUCKETS; i++) { |
| 624 | struct hlist_node *tmp; |
| 625 | struct nfqnl_instance *inst; |
| 626 | struct hlist_head *head = &instance_table[i]; |
| 627 | |
| 628 | hlist_for_each_entry(inst, tmp, head, hlist) { |
| 629 | struct nfqnl_queue_entry *entry; |
| 630 | while ((entry = find_dequeue_entry(inst, dev_cmp, |
| 631 | ifindex)) != NULL) |
| 632 | issue_verdict(entry, NF_DROP); |
| 633 | } |
| 634 | } |
| 635 | |
| 636 | read_unlock_bh(&instances_lock); |
| 637 | } |
| 638 | |
| 639 | #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0) |
| 640 | |
| 641 | static int |
| 642 | nfqnl_rcv_dev_event(struct notifier_block *this, |
| 643 | unsigned long event, void *ptr) |
| 644 | { |
| 645 | struct net_device *dev = ptr; |
| 646 | |
| 647 | /* Drop any packets associated with the downed device */ |
| 648 | if (event == NETDEV_DOWN) |
| 649 | nfqnl_dev_drop(dev->ifindex); |
| 650 | return NOTIFY_DONE; |
| 651 | } |
| 652 | |
| 653 | static struct notifier_block nfqnl_dev_notifier = { |
| 654 | .notifier_call = nfqnl_rcv_dev_event, |
| 655 | }; |
| 656 | |
| 657 | static int |
| 658 | nfqnl_rcv_nl_event(struct notifier_block *this, |
| 659 | unsigned long event, void *ptr) |
| 660 | { |
| 661 | struct netlink_notify *n = ptr; |
| 662 | |
| 663 | if (event == NETLINK_URELEASE && |
| 664 | n->protocol == NETLINK_NETFILTER && n->pid) { |
| 665 | int i; |
| 666 | |
| 667 | /* destroy all instances for this pid */ |
| 668 | write_lock_bh(&instances_lock); |
| 669 | for (i = 0; i < INSTANCE_BUCKETS; i++) { |
| 670 | struct hlist_node *tmp, *t2; |
| 671 | struct nfqnl_instance *inst; |
| 672 | struct hlist_head *head = &instance_table[i]; |
| 673 | |
| 674 | hlist_for_each_entry_safe(inst, tmp, t2, head, hlist) { |
| 675 | if (n->pid == inst->peer_pid) |
| 676 | __instance_destroy(inst); |
| 677 | } |
| 678 | } |
| 679 | write_unlock_bh(&instances_lock); |
| 680 | } |
| 681 | return NOTIFY_DONE; |
| 682 | } |
| 683 | |
| 684 | static struct notifier_block nfqnl_rtnl_notifier = { |
| 685 | .notifier_call = nfqnl_rcv_nl_event, |
| 686 | }; |
| 687 | |
| 688 | static int |
| 689 | nfqnl_recv_verdict(struct sock *ctnl, struct sk_buff *skb, |
| 690 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) |
| 691 | { |
| 692 | struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); |
| 693 | u_int16_t queue_num = ntohs(nfmsg->res_id); |
| 694 | |
| 695 | struct nfqnl_msg_verdict_hdr *vhdr; |
| 696 | struct nfqnl_instance *queue; |
| 697 | unsigned int verdict; |
| 698 | struct nfqnl_queue_entry *entry; |
| 699 | |
| 700 | queue = instance_lookup(queue_num); |
| 701 | if (!queue) |
| 702 | return -ENODEV; |
| 703 | |
| 704 | if (queue->peer_pid != NETLINK_CB(skb).pid) |
| 705 | return -EPERM; |
| 706 | |
| 707 | if (!nfqa[NFQA_VERDICT_HDR-1]) |
| 708 | return -EINVAL; |
| 709 | |
| 710 | vhdr = NFA_DATA(nfqa[NFQA_VERDICT_HDR-1]); |
| 711 | verdict = ntohl(vhdr->verdict); |
| 712 | |
| 713 | if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT) |
| 714 | return -EINVAL; |
| 715 | |
| 716 | entry = find_dequeue_entry(queue, id_cmp, ntohl(vhdr->id)); |
| 717 | if (entry == NULL) |
| 718 | return -ENOENT; |
| 719 | |
| 720 | if (nfqa[NFQA_PAYLOAD-1]) { |
| 721 | if (nfqnl_mangle(NFA_DATA(nfqa[NFQA_PAYLOAD-1]), |
| 722 | NFA_PAYLOAD(nfqa[NFQA_PAYLOAD-1]), entry) < 0) |
| 723 | verdict = NF_DROP; |
| 724 | } |
| 725 | |
| 726 | if (nfqa[NFQA_MARK-1]) |
| 727 | skb->nfmark = ntohl(*(u_int32_t *)NFA_DATA(nfqa[NFQA_MARK-1])); |
| 728 | |
| 729 | issue_verdict(entry, verdict); |
| 730 | return 0; |
| 731 | } |
| 732 | |
| 733 | static int |
| 734 | nfqnl_recv_unsupp(struct sock *ctnl, struct sk_buff *skb, |
| 735 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) |
| 736 | { |
| 737 | return -ENOTSUPP; |
| 738 | } |
| 739 | |
| 740 | static int |
| 741 | nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb, |
| 742 | struct nlmsghdr *nlh, struct nfattr *nfqa[], int *errp) |
| 743 | { |
| 744 | struct nfgenmsg *nfmsg = NLMSG_DATA(nlh); |
| 745 | u_int16_t queue_num = ntohs(nfmsg->res_id); |
| 746 | struct nfqnl_instance *queue; |
| 747 | |
| 748 | QDEBUG("entering for msg %u\n", NFNL_MSG_TYPE(nlh->nlmsg_type)); |
| 749 | |
| 750 | queue = instance_lookup(queue_num); |
| 751 | if (nfqa[NFQA_CFG_CMD-1]) { |
| 752 | struct nfqnl_msg_config_cmd *cmd; |
| 753 | cmd = NFA_DATA(nfqa[NFQA_CFG_CMD-1]); |
| 754 | QDEBUG("found CFG_CMD\n"); |
| 755 | |
| 756 | switch (cmd->command) { |
| 757 | case NFQNL_CFG_CMD_BIND: |
| 758 | if (queue) |
| 759 | return -EBUSY; |
| 760 | |
| 761 | queue = instance_create(queue_num, NETLINK_CB(skb).pid); |
| 762 | if (!queue) |
| 763 | return -EINVAL; |
| 764 | break; |
| 765 | case NFQNL_CFG_CMD_UNBIND: |
| 766 | if (!queue) |
| 767 | return -ENODEV; |
| 768 | |
| 769 | if (queue->peer_pid != NETLINK_CB(skb).pid) |
| 770 | return -EPERM; |
| 771 | |
| 772 | instance_destroy(queue); |
| 773 | break; |
| 774 | case NFQNL_CFG_CMD_PF_BIND: |
| 775 | QDEBUG("registering queue handler for pf=%u\n", |
| 776 | ntohs(cmd->pf)); |
| 777 | return nf_register_queue_handler(ntohs(cmd->pf), |
| 778 | nfqnl_enqueue_packet, |
| 779 | NULL); |
| 780 | |
| 781 | break; |
| 782 | case NFQNL_CFG_CMD_PF_UNBIND: |
| 783 | QDEBUG("unregistering queue handler for pf=%u\n", |
| 784 | ntohs(cmd->pf)); |
| 785 | /* This is a bug and a feature. We can unregister |
| 786 | * other handlers(!) */ |
| 787 | return nf_unregister_queue_handler(ntohs(cmd->pf)); |
| 788 | break; |
| 789 | default: |
| 790 | return -EINVAL; |
| 791 | } |
| 792 | } else { |
| 793 | if (!queue) { |
| 794 | QDEBUG("no config command, and no instance ENOENT\n"); |
| 795 | return -ENOENT; |
| 796 | } |
| 797 | |
| 798 | if (queue->peer_pid != NETLINK_CB(skb).pid) { |
| 799 | QDEBUG("no config command, and wrong pid\n"); |
| 800 | return -EPERM; |
| 801 | } |
| 802 | } |
| 803 | |
| 804 | if (nfqa[NFQA_CFG_PARAMS-1]) { |
| 805 | struct nfqnl_msg_config_params *params; |
| 806 | params = NFA_DATA(nfqa[NFQA_CFG_PARAMS-1]); |
| 807 | |
| 808 | nfqnl_set_mode(queue, params->copy_mode, |
| 809 | ntohl(params->copy_range)); |
| 810 | } |
| 811 | |
| 812 | return 0; |
| 813 | } |
| 814 | |
| 815 | static struct nfnl_callback nfqnl_cb[NFQNL_MSG_MAX] = { |
| 816 | [NFQNL_MSG_PACKET] = { .call = nfqnl_recv_unsupp, |
| 817 | .cap_required = CAP_NET_ADMIN }, |
| 818 | [NFQNL_MSG_VERDICT] = { .call = nfqnl_recv_verdict, |
| 819 | .cap_required = CAP_NET_ADMIN }, |
| 820 | [NFQNL_MSG_CONFIG] = { .call = nfqnl_recv_config, |
| 821 | .cap_required = CAP_NET_ADMIN }, |
| 822 | }; |
| 823 | |
| 824 | static struct nfnetlink_subsystem nfqnl_subsys = { |
| 825 | .name = "nf_queue", |
| 826 | .subsys_id = NFNL_SUBSYS_QUEUE, |
| 827 | .cb_count = NFQNL_MSG_MAX, |
| 828 | .attr_count = NFQA_MAX, |
| 829 | .cb = nfqnl_cb, |
| 830 | }; |
| 831 | |
| 832 | static int |
| 833 | init_or_cleanup(int init) |
| 834 | { |
| 835 | int status = -ENOMEM; |
| 836 | |
| 837 | if (!init) |
| 838 | goto cleanup; |
| 839 | |
| 840 | netlink_register_notifier(&nfqnl_rtnl_notifier); |
| 841 | status = nfnetlink_subsys_register(&nfqnl_subsys); |
| 842 | if (status < 0) { |
| 843 | printk(KERN_ERR "nf_queue: failed to create netlink socket\n"); |
| 844 | goto cleanup_netlink_notifier; |
| 845 | } |
| 846 | |
| 847 | register_netdevice_notifier(&nfqnl_dev_notifier); |
| 848 | return status; |
| 849 | |
| 850 | cleanup: |
| 851 | nf_unregister_queue_handlers(nfqnl_enqueue_packet); |
| 852 | unregister_netdevice_notifier(&nfqnl_dev_notifier); |
| 853 | nfnetlink_subsys_unregister(&nfqnl_subsys); |
| 854 | |
| 855 | cleanup_netlink_notifier: |
| 856 | netlink_unregister_notifier(&nfqnl_rtnl_notifier); |
| 857 | return status; |
| 858 | } |
| 859 | |
| 860 | static int __init init(void) |
| 861 | { |
| 862 | |
| 863 | return init_or_cleanup(1); |
| 864 | } |
| 865 | |
| 866 | static void __exit fini(void) |
| 867 | { |
| 868 | init_or_cleanup(0); |
| 869 | } |
| 870 | |
| 871 | MODULE_DESCRIPTION("netfilter packet queue handler"); |
| 872 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); |
| 873 | MODULE_LICENSE("GPL"); |
| 874 | MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_QUEUE); |
| 875 | |
| 876 | module_init(init); |
| 877 | module_exit(fini); |