Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 1 | #include <linux/kernel.h> |
| 2 | #include <linux/init.h> |
| 3 | #include <linux/module.h> |
| 4 | #include <linux/proc_fs.h> |
| 5 | #include <linux/skbuff.h> |
| 6 | #include <linux/netfilter.h> |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 7 | #include <linux/seq_file.h> |
Patrick McHardy | 7a11b98 | 2006-02-27 13:03:24 -0800 | [diff] [blame] | 8 | #include <linux/rcupdate.h> |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 9 | #include <net/protocol.h> |
| 10 | |
| 11 | #include "nf_internals.h" |
| 12 | |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 13 | /* |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 14 | * A queue handler may be registered for each protocol. Each is protected by |
| 15 | * long term mutex. The handler must provide an an outfn() to accept packets |
| 16 | * for queueing and must reinject all packets it receives, no matter what. |
| 17 | */ |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 18 | static struct nf_queue_handler *queue_handler[NPROTO]; |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 19 | |
| 20 | static DEFINE_RWLOCK(queue_handler_lock); |
| 21 | |
Harald Welte | d72367b | 2005-08-09 20:23:36 -0700 | [diff] [blame] | 22 | /* return EBUSY when somebody else is registered, return EEXIST if the |
| 23 | * same handler is registered, return 0 in case of success. */ |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 24 | int nf_register_queue_handler(int pf, struct nf_queue_handler *qh) |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 25 | { |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 26 | int ret; |
| 27 | |
| 28 | if (pf >= NPROTO) |
| 29 | return -EINVAL; |
| 30 | |
| 31 | write_lock_bh(&queue_handler_lock); |
Harald Welte | d72367b | 2005-08-09 20:23:36 -0700 | [diff] [blame] | 32 | if (queue_handler[pf] == qh) |
| 33 | ret = -EEXIST; |
| 34 | else if (queue_handler[pf]) |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 35 | ret = -EBUSY; |
| 36 | else { |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 37 | queue_handler[pf] = qh; |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 38 | ret = 0; |
| 39 | } |
| 40 | write_unlock_bh(&queue_handler_lock); |
| 41 | |
| 42 | return ret; |
| 43 | } |
| 44 | EXPORT_SYMBOL(nf_register_queue_handler); |
| 45 | |
| 46 | /* The caller must flush their queue before this */ |
| 47 | int nf_unregister_queue_handler(int pf) |
| 48 | { |
| 49 | if (pf >= NPROTO) |
| 50 | return -EINVAL; |
| 51 | |
| 52 | write_lock_bh(&queue_handler_lock); |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 53 | queue_handler[pf] = NULL; |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 54 | write_unlock_bh(&queue_handler_lock); |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 55 | |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 56 | return 0; |
| 57 | } |
| 58 | EXPORT_SYMBOL(nf_unregister_queue_handler); |
| 59 | |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 60 | void nf_unregister_queue_handlers(struct nf_queue_handler *qh) |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 61 | { |
| 62 | int pf; |
| 63 | |
| 64 | write_lock_bh(&queue_handler_lock); |
| 65 | for (pf = 0; pf < NPROTO; pf++) { |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 66 | if (queue_handler[pf] == qh) |
| 67 | queue_handler[pf] = NULL; |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 68 | } |
| 69 | write_unlock_bh(&queue_handler_lock); |
| 70 | } |
| 71 | EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers); |
| 72 | |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 73 | /* |
| 74 | * Any packet that leaves via this function must come back |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 75 | * through nf_reinject(). |
| 76 | */ |
Patrick McHardy | 394f545 | 2006-08-05 00:58:52 -0700 | [diff] [blame] | 77 | static int __nf_queue(struct sk_buff *skb, |
| 78 | struct list_head *elem, |
| 79 | int pf, unsigned int hook, |
| 80 | struct net_device *indev, |
| 81 | struct net_device *outdev, |
| 82 | int (*okfn)(struct sk_buff *), |
| 83 | unsigned int queuenum) |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 84 | { |
| 85 | int status; |
| 86 | struct nf_info *info; |
| 87 | #ifdef CONFIG_BRIDGE_NETFILTER |
| 88 | struct net_device *physindev = NULL; |
| 89 | struct net_device *physoutdev = NULL; |
| 90 | #endif |
Patrick McHardy | bce8032 | 2006-04-06 14:18:09 -0700 | [diff] [blame] | 91 | struct nf_afinfo *afinfo; |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 92 | |
| 93 | /* QUEUE == DROP if noone is waiting, to be safe. */ |
| 94 | read_lock(&queue_handler_lock); |
Patrick McHardy | e121e9e | 2006-02-27 13:03:39 -0800 | [diff] [blame] | 95 | if (!queue_handler[pf]) { |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 96 | read_unlock(&queue_handler_lock); |
Patrick McHardy | 394f545 | 2006-08-05 00:58:52 -0700 | [diff] [blame] | 97 | kfree_skb(skb); |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 98 | return 1; |
| 99 | } |
| 100 | |
Patrick McHardy | bce8032 | 2006-04-06 14:18:09 -0700 | [diff] [blame] | 101 | afinfo = nf_get_afinfo(pf); |
| 102 | if (!afinfo) { |
| 103 | read_unlock(&queue_handler_lock); |
Patrick McHardy | 394f545 | 2006-08-05 00:58:52 -0700 | [diff] [blame] | 104 | kfree_skb(skb); |
Patrick McHardy | bce8032 | 2006-04-06 14:18:09 -0700 | [diff] [blame] | 105 | return 1; |
| 106 | } |
| 107 | |
| 108 | info = kmalloc(sizeof(*info) + afinfo->route_key_size, GFP_ATOMIC); |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 109 | if (!info) { |
| 110 | if (net_ratelimit()) |
| 111 | printk(KERN_ERR "OOM queueing packet %p\n", |
Patrick McHardy | 394f545 | 2006-08-05 00:58:52 -0700 | [diff] [blame] | 112 | skb); |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 113 | read_unlock(&queue_handler_lock); |
Patrick McHardy | 394f545 | 2006-08-05 00:58:52 -0700 | [diff] [blame] | 114 | kfree_skb(skb); |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 115 | return 1; |
| 116 | } |
| 117 | |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 118 | *info = (struct nf_info) { |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 119 | (struct nf_hook_ops *)elem, pf, hook, indev, outdev, okfn }; |
| 120 | |
| 121 | /* If it's going away, ignore hook. */ |
| 122 | if (!try_module_get(info->elem->owner)) { |
| 123 | read_unlock(&queue_handler_lock); |
| 124 | kfree(info); |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | /* Bump dev refs so they don't vanish while packet is out */ |
| 129 | if (indev) dev_hold(indev); |
| 130 | if (outdev) dev_hold(outdev); |
| 131 | |
| 132 | #ifdef CONFIG_BRIDGE_NETFILTER |
Patrick McHardy | 394f545 | 2006-08-05 00:58:52 -0700 | [diff] [blame] | 133 | if (skb->nf_bridge) { |
| 134 | physindev = skb->nf_bridge->physindev; |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 135 | if (physindev) dev_hold(physindev); |
Patrick McHardy | 394f545 | 2006-08-05 00:58:52 -0700 | [diff] [blame] | 136 | physoutdev = skb->nf_bridge->physoutdev; |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 137 | if (physoutdev) dev_hold(physoutdev); |
| 138 | } |
| 139 | #endif |
Patrick McHardy | 394f545 | 2006-08-05 00:58:52 -0700 | [diff] [blame] | 140 | afinfo->saveroute(skb, info); |
| 141 | status = queue_handler[pf]->outfn(skb, info, queuenum, |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 142 | queue_handler[pf]->data); |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 143 | |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 144 | read_unlock(&queue_handler_lock); |
| 145 | |
| 146 | if (status < 0) { |
| 147 | /* James M doesn't say fuck enough. */ |
| 148 | if (indev) dev_put(indev); |
| 149 | if (outdev) dev_put(outdev); |
| 150 | #ifdef CONFIG_BRIDGE_NETFILTER |
| 151 | if (physindev) dev_put(physindev); |
| 152 | if (physoutdev) dev_put(physoutdev); |
| 153 | #endif |
| 154 | module_put(info->elem->owner); |
| 155 | kfree(info); |
Patrick McHardy | 394f545 | 2006-08-05 00:58:52 -0700 | [diff] [blame] | 156 | kfree_skb(skb); |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 157 | |
| 158 | return 1; |
| 159 | } |
| 160 | |
| 161 | return 1; |
| 162 | } |
| 163 | |
Patrick McHardy | 394f545 | 2006-08-05 00:58:52 -0700 | [diff] [blame] | 164 | int nf_queue(struct sk_buff *skb, |
| 165 | struct list_head *elem, |
| 166 | int pf, unsigned int hook, |
| 167 | struct net_device *indev, |
| 168 | struct net_device *outdev, |
| 169 | int (*okfn)(struct sk_buff *), |
| 170 | unsigned int queuenum) |
| 171 | { |
| 172 | struct sk_buff *segs; |
| 173 | |
| 174 | if (!skb_is_gso(skb)) |
| 175 | return __nf_queue(skb, elem, pf, hook, indev, outdev, okfn, |
| 176 | queuenum); |
| 177 | |
| 178 | switch (pf) { |
| 179 | case AF_INET: |
| 180 | skb->protocol = htons(ETH_P_IP); |
| 181 | break; |
| 182 | case AF_INET6: |
| 183 | skb->protocol = htons(ETH_P_IPV6); |
| 184 | break; |
| 185 | } |
| 186 | |
| 187 | segs = skb_gso_segment(skb, 0); |
| 188 | kfree_skb(skb); |
| 189 | if (unlikely(IS_ERR(segs))) |
| 190 | return 1; |
| 191 | |
| 192 | do { |
| 193 | struct sk_buff *nskb = segs->next; |
| 194 | |
| 195 | segs->next = NULL; |
| 196 | if (!__nf_queue(segs, elem, pf, hook, indev, outdev, okfn, |
| 197 | queuenum)) |
| 198 | kfree_skb(segs); |
| 199 | segs = nskb; |
| 200 | } while (segs); |
| 201 | return 1; |
| 202 | } |
| 203 | |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 204 | void nf_reinject(struct sk_buff *skb, struct nf_info *info, |
| 205 | unsigned int verdict) |
| 206 | { |
| 207 | struct list_head *elem = &info->elem->list; |
| 208 | struct list_head *i; |
Patrick McHardy | bce8032 | 2006-04-06 14:18:09 -0700 | [diff] [blame] | 209 | struct nf_afinfo *afinfo; |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 210 | |
| 211 | rcu_read_lock(); |
| 212 | |
| 213 | /* Release those devices we held, or Alexey will kill me. */ |
| 214 | if (info->indev) dev_put(info->indev); |
| 215 | if (info->outdev) dev_put(info->outdev); |
| 216 | #ifdef CONFIG_BRIDGE_NETFILTER |
| 217 | if (skb->nf_bridge) { |
| 218 | if (skb->nf_bridge->physindev) |
| 219 | dev_put(skb->nf_bridge->physindev); |
| 220 | if (skb->nf_bridge->physoutdev) |
| 221 | dev_put(skb->nf_bridge->physoutdev); |
| 222 | } |
| 223 | #endif |
| 224 | |
| 225 | /* Drop reference to owner of hook which queued us. */ |
| 226 | module_put(info->elem->owner); |
| 227 | |
| 228 | list_for_each_rcu(i, &nf_hooks[info->pf][info->hook]) { |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 229 | if (i == elem) |
| 230 | break; |
| 231 | } |
| 232 | |
Patrick McHardy | 45fe4dc | 2006-02-27 13:03:55 -0800 | [diff] [blame] | 233 | if (i == &nf_hooks[info->pf][info->hook]) { |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 234 | /* The module which sent it to userspace is gone. */ |
| 235 | NFDEBUG("%s: module disappeared, dropping packet.\n", |
| 236 | __FUNCTION__); |
| 237 | verdict = NF_DROP; |
| 238 | } |
| 239 | |
| 240 | /* Continue traversal iff userspace said ok... */ |
| 241 | if (verdict == NF_REPEAT) { |
| 242 | elem = elem->prev; |
| 243 | verdict = NF_ACCEPT; |
| 244 | } |
| 245 | |
| 246 | if (verdict == NF_ACCEPT) { |
Patrick McHardy | bce8032 | 2006-04-06 14:18:09 -0700 | [diff] [blame] | 247 | afinfo = nf_get_afinfo(info->pf); |
| 248 | if (!afinfo || afinfo->reroute(&skb, info) < 0) |
Patrick McHardy | 7a11b98 | 2006-02-27 13:03:24 -0800 | [diff] [blame] | 249 | verdict = NF_DROP; |
| 250 | } |
| 251 | |
| 252 | if (verdict == NF_ACCEPT) { |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 253 | next_hook: |
| 254 | verdict = nf_iterate(&nf_hooks[info->pf][info->hook], |
YOSHIFUJI Hideaki | 601e68e | 2007-02-12 11:15:49 -0800 | [diff] [blame] | 255 | &skb, info->hook, |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 256 | info->indev, info->outdev, &elem, |
| 257 | info->okfn, INT_MIN); |
| 258 | } |
| 259 | |
| 260 | switch (verdict & NF_VERDICT_MASK) { |
| 261 | case NF_ACCEPT: |
Patrick McHardy | 3bc3871 | 2006-07-24 22:52:47 -0700 | [diff] [blame] | 262 | case NF_STOP: |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 263 | info->okfn(skb); |
Patrick McHardy | 3bc3871 | 2006-07-24 22:52:47 -0700 | [diff] [blame] | 264 | case NF_STOLEN: |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 265 | break; |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 266 | case NF_QUEUE: |
Patrick McHardy | 394f545 | 2006-08-05 00:58:52 -0700 | [diff] [blame] | 267 | if (!__nf_queue(skb, elem, info->pf, info->hook, |
| 268 | info->indev, info->outdev, info->okfn, |
| 269 | verdict >> NF_VERDICT_BITS)) |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 270 | goto next_hook; |
| 271 | break; |
Patrick McHardy | 3bc3871 | 2006-07-24 22:52:47 -0700 | [diff] [blame] | 272 | default: |
| 273 | kfree_skb(skb); |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 274 | } |
| 275 | rcu_read_unlock(); |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 276 | kfree(info); |
| 277 | return; |
| 278 | } |
| 279 | EXPORT_SYMBOL(nf_reinject); |
| 280 | |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 281 | #ifdef CONFIG_PROC_FS |
| 282 | static void *seq_start(struct seq_file *seq, loff_t *pos) |
| 283 | { |
| 284 | if (*pos >= NPROTO) |
| 285 | return NULL; |
| 286 | |
| 287 | return pos; |
| 288 | } |
| 289 | |
| 290 | static void *seq_next(struct seq_file *s, void *v, loff_t *pos) |
| 291 | { |
| 292 | (*pos)++; |
| 293 | |
| 294 | if (*pos >= NPROTO) |
| 295 | return NULL; |
| 296 | |
| 297 | return pos; |
| 298 | } |
| 299 | |
| 300 | static void seq_stop(struct seq_file *s, void *v) |
| 301 | { |
| 302 | |
| 303 | } |
| 304 | |
| 305 | static int seq_show(struct seq_file *s, void *v) |
| 306 | { |
| 307 | int ret; |
| 308 | loff_t *pos = v; |
| 309 | struct nf_queue_handler *qh; |
| 310 | |
| 311 | read_lock_bh(&queue_handler_lock); |
| 312 | qh = queue_handler[*pos]; |
| 313 | if (!qh) |
| 314 | ret = seq_printf(s, "%2lld NONE\n", *pos); |
| 315 | else |
| 316 | ret = seq_printf(s, "%2lld %s\n", *pos, qh->name); |
| 317 | read_unlock_bh(&queue_handler_lock); |
| 318 | |
| 319 | return ret; |
| 320 | } |
| 321 | |
| 322 | static struct seq_operations nfqueue_seq_ops = { |
| 323 | .start = seq_start, |
| 324 | .next = seq_next, |
| 325 | .stop = seq_stop, |
| 326 | .show = seq_show, |
| 327 | }; |
| 328 | |
| 329 | static int nfqueue_open(struct inode *inode, struct file *file) |
| 330 | { |
| 331 | return seq_open(file, &nfqueue_seq_ops); |
| 332 | } |
| 333 | |
Arjan van de Ven | da7071d | 2007-02-12 00:55:36 -0800 | [diff] [blame] | 334 | static const struct file_operations nfqueue_file_ops = { |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 335 | .owner = THIS_MODULE, |
| 336 | .open = nfqueue_open, |
| 337 | .read = seq_read, |
| 338 | .llseek = seq_lseek, |
| 339 | .release = seq_release, |
| 340 | }; |
| 341 | #endif /* PROC_FS */ |
| 342 | |
| 343 | |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 344 | int __init netfilter_queue_init(void) |
| 345 | { |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 346 | #ifdef CONFIG_PROC_FS |
| 347 | struct proc_dir_entry *pde; |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 348 | |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 349 | pde = create_proc_entry("nf_queue", S_IRUGO, proc_net_netfilter); |
Patrick McHardy | e02f7d1 | 2006-02-27 13:02:52 -0800 | [diff] [blame] | 350 | if (!pde) |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 351 | return -1; |
Harald Welte | bbd86b9f | 2005-08-09 20:23:11 -0700 | [diff] [blame] | 352 | pde->proc_fops = &nfqueue_file_ops; |
| 353 | #endif |
Harald Welte | f6ebe77 | 2005-08-09 20:21:49 -0700 | [diff] [blame] | 354 | return 0; |
| 355 | } |
| 356 | |