/*
* This is a module which is used for queueing packets and communicating with
* userspace via nfnetlink.
*
* (C) 2005 by Harald Welte <laforge@netfilter.org>
* (C) 2007 by Patrick McHardy <kaber@trash.net>
*
* Based on the old ipv4-only ip_queue.c:
* (C) 2000-2002 James Morris <jmorris@intercode.com.au>
* (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/notifier.h>
#include <linux/netdevice.h>
#include <linux/netfilter.h>
#include <linux/proc_fs.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_queue.h>
#include <linux/list.h>
#include <net/sock.h>
#include <net/netfilter/nf_queue.h>
#include <linux/atomic.h>
#ifdef CONFIG_BRIDGE_NETFILTER
#include "../bridge/br_private.h"
#endif
#define NFQNL_QMAX_DEFAULT 1024
struct nfqnl_instance {
struct hlist_node hlist; /* global list of queues */
struct rcu_head rcu;
int peer_pid;
unsigned int queue_maxlen;
unsigned int copy_range;
unsigned int queue_dropped;
unsigned int queue_user_dropped;
u_int16_t queue_num; /* number of this queue */
u_int8_t copy_mode;
/*
* Following fields are dirtied for each queued packet,
* keep them in same cache line if possible.
*/
spinlock_t lock;
unsigned int queue_total;
unsigned int id_sequence; /* 'sequence' of pkt ids */
struct list_head queue_list; /* packets in queue */
};
typedef int (*nfqnl_cmpfn)(struct nf_queue_entry *, unsigned long);
static DEFINE_SPINLOCK(instances_lock);
#define INSTANCE_BUCKETS 16
static struct hlist_head instance_table[INSTANCE_BUCKETS] __read_mostly;
static inline u_int8_t instance_hashfn(u_int16_t queue_num)
{
return ((queue_num >> 8) | queue_num) % INSTANCE_BUCKETS;
}
static struct nfqnl_instance *
instance_lookup(u_int16_t queue_num)
{
struct hlist_head *head;
struct hlist_node *pos;
struct nfqnl_instance *inst;
head = &instance_table[instance_hashfn(queue_num)];
hlist_for_each_entry_rcu(inst, pos, head, hlist) {
if (inst->queue_num == queue_num)
return inst;
}
return NULL;
}
static struct nfqnl_instance *
instance_create(u_int16_t queue_num, int pid)
{
struct nfqnl_instance *inst;
unsigned int h;
int err;
spin_lock(&instances_lock);
if (instance_lookup(queue_num)) {
err = -EEXIST;
goto out_unlock;
}
inst = kzalloc(sizeof(*inst), GFP_ATOMIC);
if (!inst) {
err = -ENOMEM;
goto out_unlock;
}
inst->queue_num = queue_num;
inst->peer_pid = pid;
inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
inst->copy_range = 0xfffff;
inst->copy_mode = NFQNL_COPY_NONE;
spin_lock_init(&inst->lock);
INIT_LIST_HEAD(&inst->queue_list);
if (!try_module_get(THIS_MODULE)) {
err = -EAGAIN;
goto out_free;
}
h = instance_hashfn(queue_num);
hlist_add_head_rcu(&inst->hlist, &instance_table[h]);
spin_unlock(&instances_lock);
return inst;
out_free:
kfree(inst);
out_unlock:
spin_unlock(&instances_lock);
return ERR_PTR(err);
}
static void nfqnl_flush(struct nfqnl_instance *queue, nfqnl_cmpfn cmpfn,
unsigned long data);
static void
instance_destroy_rcu(struct rcu_head *head)
{
struct nfqnl_instance *inst = container_of(head, struct nfqnl_instance,
rcu);
nfqnl_flush(inst, NULL, 0);
kfree(inst);
module_put(THIS_MODULE);
}
static void
__instance_destroy(struct nfqnl_instance *inst)
{
hlist_del_rcu(&inst->hlist);
call_rcu(&inst->rcu, instance_destroy_rcu);
}
static void
instance_destroy(struct nfqnl_instance *inst)
{
spin_lock(&instances_lock);
__instance_destroy(inst);
spin_unlock(&instances_lock);
}
static inline void
__enqueue_entry(struct nfqnl_instance *queue, struct nf_queue_entry *entry)
{
list_add_tail(<