blob: ed00fef58996a8d702b6020720daf679caa1af15 [file] [log] [blame]
/* iptables module for using new netfilter netlink queue
*
* (C) 2005 by Harald Welte <laforge@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/ip.h>
#include <linux/ipv6.h>
#include <linux/jhash.h>
#include <linux/netfilter.h>
#include <linux/netfilter_arp.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_NFQUEUE.h>
MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>");
MODULE_DESCRIPTION("Xtables: packet forwarding to netlink");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_NFQUEUE");
MODULE_ALIAS("ip6t_NFQUEUE");
MODULE_ALIAS("arpt_NFQUEUE");
static u32 jhash_initval __read_mostly;
static bool rnd_inited __read_mostly;
static unsigned int
nfqueue_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_NFQ_info *tinfo = par->targinfo;
return NF_QUEUE_NR(tinfo->queuenum);
}
static u32 hash_v4(const struct sk_buff *skb)
{
const struct iphdr *iph = ip_hdr(skb);
/* packets in either direction go into same queue */
if ((__force u32)iph->saddr < (__force u32)iph->daddr)
return jhash_3words((__force u32)iph->saddr,
(__force u32)iph->daddr, iph->protocol, jhash_initval);
return jhash_3words((__force u32)iph->daddr,
(__force u32)iph->saddr, iph->protocol, jhash_initval);
}
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
static u32 hash_v6(const struct sk_buff *skb)
{
const struct ipv6hdr *ip6h = ipv6_hdr(skb);
u32 a, b, c;
if ((__force u32)ip6h->saddr.s6_addr32[3] <
(__force u32)ip6h->daddr.s6_addr32[3]) {
a = (__force u32) ip6h->saddr.s6_addr32[3];
b = (__force u32) ip6h->daddr.s6_addr32[3];
} else {
b = (__force u32) ip6h->saddr.s6_addr32[3];
a = (__force u32) ip6h->daddr.s6_addr32[3];
}
if ((__force u32)ip6h->saddr.s6_addr32[1] <
(__force u32)ip6h->daddr.s6_addr32[1])
c = (__force u32) ip6h->saddr.s6_addr32[1];
else
c = (__force u32) ip6h->daddr.s6_addr32[1];
return jhash_3words(a, b, c, jhash_initval);
}
#endif
static u32
nfqueue_hash(const struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_NFQ_info_v1 *info = par->targinfo;
u32 queue = info->queuenum;
if (par->family == NFPROTO_IPV4)
queue += ((u64) hash_v4(skb) * info->queues_total) >> 32;
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
else if (par->family == NFPROTO_IPV6)
queue += ((u64) hash_v6(skb) * info->queues_total) >> 32;
#endif
return queue;
}
static unsigned int
nfqueue_tg_v1(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_NFQ_info_v1 *info = par->targinfo;
u32 queue = info->queuenum;
if (info->queues_total > 1)
queue = nfqueue_hash(skb, par);
return NF_QUEUE_NR(queue);
}
static unsigned int
nfqueue_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_NFQ_info_v2 *info = par->targinfo;
unsigned int ret = nfqueue_tg_v1(skb, par);
if (info->bypass)
ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
return ret;
}
static int nfqueue_tg_check(const struct xt_tgchk_param *par)
{
const struct xt_NFQ_info_v3 *info = par->targinfo;
u32 maxid;
if (unlikely(!rnd_inited)) {
get_random_bytes(&jhash_initval, sizeof(jhash_initval));
rnd_inited = true;
}
if (info->queues_total == 0) {
pr_err("NFQUEUE: number of total queues is 0\n");
return -EINVAL;
}
maxid = info->queues_total - 1 + info->queuenum;
if (maxid > 0xffff) {
pr_err("NFQUEUE: number of queues (%u) out of range (got %u)\n",
info->queues_total, maxid);
return -ERANGE;
}
if (par->target->revision == 2 && info->flags > 1)
return -EINVAL;
if (par->target->revision == 3 && info->flags & ~NFQ_FLAG_MASK)
return -EINVAL;
return 0;
}
static unsigned int
nfqueue_tg_v3(struct sk_buff *skb, const struct xt_action_param *par)
{
const struct xt_NFQ_info_v3 *info = par->targinfo;
u32 queue = info->queuenum;
int ret;
if (info->queues_total > 1) {
if (info->flags & NFQ_FLAG_CPU_FANOUT) {
int cpu = smp_processor_id();
queue = info->queuenum + cpu % info->queues_total;
} else
queue = nfqueue_hash(skb, par);
}
ret = NF_QUEUE_NR(queue);
if (info->flags & NFQ_FLAG_BYPASS)
ret |= NF_VERDICT_FLAG_QUEUE_BYPASS;
return ret;
}
static struct xt_target nfqueue_tg_reg[] __read_mostly = {
{
.name = "NFQUEUE",
.family = NFPROTO_UNSPEC,
.target = nfqueue_tg,
.targetsize = sizeof(struct xt_NFQ_info),
.me = THIS_MODULE,
},
{
.name = "NFQUEUE",
.revision = 1,
.family = NFPROTO_UNSPEC,
.checkentry = nfqueue_tg_check,
.target = nfqueue_tg_v1,
.targetsize = sizeof(struct xt_NFQ_info_v1),
.me = THIS_MODULE,
},
{
.name = "NFQUEUE",
.revision = 2,
.family = NFPROTO_UNSPEC,
.checkentry = nfqueue_tg_check,
.target = nfqueue_tg_v2,
.targetsize = sizeof(struct xt_NFQ_info_v2),
.me = THIS_MODULE,
},
{
.name = "NFQUEUE",
.revision = 3,
.family = NFPROTO_UNSPEC,
.checkentry = nfqueue_tg_check,
.target = nfqueue_tg_v3,
.targetsize = sizeof(struct xt_NFQ_info_v3),
.me = THIS_MODULE,
},
};
static int __init nfqueue_tg_init(void)
{
return xt_register_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
}
static void __exit nfqueue_tg_exit(void)
{
xt_unregister_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg));
}
module_init(nfqueue_tg_init);
module_exit(nfqueue_tg_exit);