From f6ebe77f955d77a988ce726f0818ec0103b11323 Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Tue, 9 Aug 2005 20:21:49 -0700 Subject: [NETFILTER]: split net/core/netfilter.c into net/netfilter/*.c This patch doesn't introduce any code changes, but merely splits the core netfilter code into four separate files. It also moves it from it's old location in net/core/ to the recently-created net/netfilter/ directory. Signed-off-by: Harald Welte Signed-off-by: David S. Miller --- net/netfilter/nf_queue.c | 273 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 273 insertions(+) create mode 100644 net/netfilter/nf_queue.c (limited to 'net/netfilter/nf_queue.c') diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c new file mode 100644 index 00000000000..5586f843ed4 --- /dev/null +++ b/net/netfilter/nf_queue.c @@ -0,0 +1,273 @@ +#include +#include +#include +#include +#include +#include +#include +#include + +#include "nf_internals.h" + +/* + * A queue handler may be registered for each protocol. Each is protected by + * long term mutex. The handler must provide an an outfn() to accept packets + * for queueing and must reinject all packets it receives, no matter what. + */ +static struct nf_queue_handler_t { + nf_queue_outfn_t outfn; + void *data; +} queue_handler[NPROTO]; + +static struct nf_queue_rerouter *queue_rerouter; + +static DEFINE_RWLOCK(queue_handler_lock); + + +int nf_register_queue_handler(int pf, nf_queue_outfn_t outfn, void *data) +{ + int ret; + + if (pf >= NPROTO) + return -EINVAL; + + write_lock_bh(&queue_handler_lock); + if (queue_handler[pf].outfn) + ret = -EBUSY; + else { + queue_handler[pf].outfn = outfn; + queue_handler[pf].data = data; + ret = 0; + } + write_unlock_bh(&queue_handler_lock); + + return ret; +} +EXPORT_SYMBOL(nf_register_queue_handler); + +/* The caller must flush their queue before this */ +int nf_unregister_queue_handler(int pf) +{ + if (pf >= NPROTO) + return -EINVAL; + + write_lock_bh(&queue_handler_lock); + queue_handler[pf].outfn = NULL; + queue_handler[pf].data = NULL; + write_unlock_bh(&queue_handler_lock); + + return 0; +} +EXPORT_SYMBOL(nf_unregister_queue_handler); + +int nf_register_queue_rerouter(int pf, struct nf_queue_rerouter *rer) +{ + if (pf >= NPROTO) + return -EINVAL; + + write_lock_bh(&queue_handler_lock); + memcpy(&queue_rerouter[pf], rer, sizeof(queue_rerouter[pf])); + write_unlock_bh(&queue_handler_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(nf_register_queue_rerouter); + +int nf_unregister_queue_rerouter(int pf) +{ + if (pf >= NPROTO) + return -EINVAL; + + write_lock_bh(&queue_handler_lock); + memset(&queue_rerouter[pf], 0, sizeof(queue_rerouter[pf])); + write_unlock_bh(&queue_handler_lock); + return 0; +} +EXPORT_SYMBOL_GPL(nf_unregister_queue_rerouter); + +void nf_unregister_queue_handlers(nf_queue_outfn_t outfn) +{ + int pf; + + write_lock_bh(&queue_handler_lock); + for (pf = 0; pf < NPROTO; pf++) { + if (queue_handler[pf].outfn == outfn) { + queue_handler[pf].outfn = NULL; + queue_handler[pf].data = NULL; + } + } + write_unlock_bh(&queue_handler_lock); +} +EXPORT_SYMBOL_GPL(nf_unregister_queue_handlers); + +/* + * Any packet that leaves via this function must come back + * through nf_reinject(). + */ +int nf_queue(struct sk_buff **skb, + struct list_head *elem, + int pf, unsigned int hook, + struct net_device *indev, + struct net_device *outdev, + int (*okfn)(struct sk_buff *), + unsigned int queuenum) +{ + int status; + struct nf_info *info; +#ifdef CONFIG_BRIDGE_NETFILTER + struct net_device *physindev = NULL; + struct net_device *physoutdev = NULL; +#endif + + /* QUEUE == DROP if noone is waiting, to be safe. */ + read_lock(&queue_handler_lock); + if (!queue_handler[pf].outfn) { + read_unlock(&queue_handler_lock); + kfree_skb(*skb); + return 1; + } + + info = kmalloc(sizeof(*info)+queue_rerouter[pf].rer_size, GFP_ATOMIC); + if (!info) { + if (net_ratelimit()) + printk(KERN_ERR "OOM queueing packet %p\n", + *skb); + read_unlock(&queue_handler_lock); + kfree_skb(*skb); + return 1; + } + + *info = (struct nf_info) { + (struct nf_hook_ops *)elem, pf, hook, indev, outdev, okfn }; + + /* If it's going away, ignore hook. */ + if (!try_module_get(info->elem->owner)) { + read_unlock(&queue_handler_lock); + kfree(info); + return 0; + } + + /* Bump dev refs so they don't vanish while packet is out */ + if (indev) dev_hold(indev); + if (outdev) dev_hold(outdev); + +#ifdef CONFIG_BRIDGE_NETFILTER + if ((*skb)->nf_bridge) { + physindev = (*skb)->nf_bridge->physindev; + if (physindev) dev_hold(physindev); + physoutdev = (*skb)->nf_bridge->physoutdev; + if (physoutdev) dev_hold(physoutdev); + } +#endif + if (queue_rerouter[pf].save) + queue_rerouter[pf].save(*skb, info); + + status = queue_handler[pf].outfn(*skb, info, queuenum, + queue_handler[pf].data); + + if (status >= 0 && queue_rerouter[pf].reroute) + status = queue_rerouter[pf].reroute(skb, info); + + read_unlock(&queue_handler_lock); + + if (status < 0) { + /* James M doesn't say fuck enough. */ + if (indev) dev_put(indev); + if (outdev) dev_put(outdev); +#ifdef CONFIG_BRIDGE_NETFILTER + if (physindev) dev_put(physindev); + if (physoutdev) dev_put(physoutdev); +#endif + module_put(info->elem->owner); + kfree(info); + kfree_skb(*skb); + + return 1; + } + + return 1; +} + +void nf_reinject(struct sk_buff *skb, struct nf_info *info, + unsigned int verdict) +{ + struct list_head *elem = &info->elem->list; + struct list_head *i; + + rcu_read_lock(); + + /* Release those devices we held, or Alexey will kill me. */ + if (info->indev) dev_put(info->indev); + if (info->outdev) dev_put(info->outdev); +#ifdef CONFIG_BRIDGE_NETFILTER + if (skb->nf_bridge) { + if (skb->nf_bridge->physindev) + dev_put(skb->nf_bridge->physindev); + if (skb->nf_bridge->physoutdev) + dev_put(skb->nf_bridge->physoutdev); + } +#endif + + /* Drop reference to owner of hook which queued us. */ + module_put(info->elem->owner); + + list_for_each_rcu(i, &nf_hooks[info->pf][info->hook]) { + if (i == elem) + break; + } + + if (elem == &nf_hooks[info->pf][info->hook]) { + /* The module which sent it to userspace is gone. */ + NFDEBUG("%s: module disappeared, dropping packet.\n", + __FUNCTION__); + verdict = NF_DROP; + } + + /* Continue traversal iff userspace said ok... */ + if (verdict == NF_REPEAT) { + elem = elem->prev; + verdict = NF_ACCEPT; + } + + if (verdict == NF_ACCEPT) { + next_hook: + verdict = nf_iterate(&nf_hooks[info->pf][info->hook], + &skb, info->hook, + info->indev, info->outdev, &elem, + info->okfn, INT_MIN); + } + + switch (verdict & NF_VERDICT_MASK) { + case NF_ACCEPT: + info->okfn(skb); + break; + + case NF_QUEUE: + if (!nf_queue(&skb, elem, info->pf, info->hook, + info->indev, info->outdev, info->okfn, + verdict >> NF_VERDICT_BITS)) + goto next_hook; + break; + } + rcu_read_unlock(); + + if (verdict == NF_DROP) + kfree_skb(skb); + + kfree(info); + return; +} +EXPORT_SYMBOL(nf_reinject); + +int __init netfilter_queue_init(void) +{ + queue_rerouter = kmalloc(NPROTO * sizeof(struct nf_queue_rerouter), + GFP_KERNEL); + if (!queue_rerouter) + return -ENOMEM; + + memset(queue_rerouter, 0, NPROTO * sizeof(struct nf_queue_rerouter)); + + return 0; +} + -- cgit v1.2.3