linux/net/sched/em_ipset.c
Florian Westphal 6d4fa852a0 net: sched: add ipset ematch
Can be used to match packets against netfilter ip sets created via ipset(8).
skb->sk_iif is used as 'incoming interface', skb->dev is 'outgoing interface'.

Since ipset is usually called from netfilter, the ematch
initializes a fake xt_action_param, pulls the ip header into the
linear area and also sets skb->data to the IP header (otherwise
matching Layer 4 set types doesn't work).

Tested-by: Mr Dash Four <mr.dash.four@googlemail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12 07:54:46 -07:00

136 lines
3.1 KiB
C

/*
* net/sched/em_ipset.c ipset ematch
*
* Copyright (c) 2012 Florian Westphal <fw@strlen.de>
*
* 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/gfp.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/netfilter/xt_set.h>
#include <linux/ipv6.h>
#include <net/ip.h>
#include <net/pkt_cls.h>
static int em_ipset_change(struct tcf_proto *tp, void *data, int data_len,
struct tcf_ematch *em)
{
struct xt_set_info *set = data;
ip_set_id_t index;
if (data_len != sizeof(*set))
return -EINVAL;
index = ip_set_nfnl_get_byindex(set->index);
if (index == IPSET_INVALID_ID)
return -ENOENT;
em->datalen = sizeof(*set);
em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
if (em->data)
return 0;
ip_set_nfnl_put(index);
return -ENOMEM;
}
static void em_ipset_destroy(struct tcf_proto *p, struct tcf_ematch *em)
{
const struct xt_set_info *set = (const void *) em->data;
if (set) {
ip_set_nfnl_put(set->index);
kfree((void *) em->data);
}
}
static int em_ipset_match(struct sk_buff *skb, struct tcf_ematch *em,
struct tcf_pkt_info *info)
{
struct ip_set_adt_opt opt;
struct xt_action_param acpar;
const struct xt_set_info *set = (const void *) em->data;
struct net_device *dev, *indev = NULL;
int ret, network_offset;
switch (skb->protocol) {
case htons(ETH_P_IP):
acpar.family = NFPROTO_IPV4;
if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
return 0;
acpar.thoff = ip_hdrlen(skb);
break;
case htons(ETH_P_IPV6):
acpar.family = NFPROTO_IPV6;
if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
return 0;
/* doesn't call ipv6_find_hdr() because ipset doesn't use thoff, yet */
acpar.thoff = sizeof(struct ipv6hdr);
break;
default:
return 0;
}
acpar.hooknum = 0;
opt.family = acpar.family;
opt.dim = set->dim;
opt.flags = set->flags;
opt.cmdflags = 0;
opt.timeout = ~0u;
network_offset = skb_network_offset(skb);
skb_pull(skb, network_offset);
dev = skb->dev;
rcu_read_lock();
if (dev && skb->skb_iif)
indev = dev_get_by_index_rcu(dev_net(dev), skb->skb_iif);
acpar.in = indev ? indev : dev;
acpar.out = dev;
ret = ip_set_test(set->index, skb, &acpar, &opt);
rcu_read_unlock();
skb_push(skb, network_offset);
return ret;
}
static struct tcf_ematch_ops em_ipset_ops = {
.kind = TCF_EM_IPSET,
.change = em_ipset_change,
.destroy = em_ipset_destroy,
.match = em_ipset_match,
.owner = THIS_MODULE,
.link = LIST_HEAD_INIT(em_ipset_ops.link)
};
static int __init init_em_ipset(void)
{
return tcf_em_register(&em_ipset_ops);
}
static void __exit exit_em_ipset(void)
{
tcf_em_unregister(&em_ipset_ops);
}
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Florian Westphal <fw@strlen.de>");
MODULE_DESCRIPTION("TC extended match for IP sets");
module_init(init_em_ipset);
module_exit(exit_em_ipset);
MODULE_ALIAS_TCF_EMATCH(TCF_EM_IPSET);