diff options
Diffstat (limited to 'net/ipv4/netfilter/nf_table_route_ipv4.c')
-rw-r--r-- | net/ipv4/netfilter/nf_table_route_ipv4.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/nf_table_route_ipv4.c b/net/ipv4/netfilter/nf_table_route_ipv4.c new file mode 100644 index 000000000000..4f257a1ed661 --- /dev/null +++ b/net/ipv4/netfilter/nf_table_route_ipv4.c @@ -0,0 +1,97 @@ +/* + * Copyright (c) 2008 Patrick McHardy <kaber@trash.net> + * + * 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/init.h> +#include <linux/list.h> +#include <linux/skbuff.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter/nfnetlink.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables.h> +#include <net/route.h> +#include <net/ip.h> + +static unsigned int nf_route_table_hook(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + unsigned int ret; + u32 mark; + __be32 saddr, daddr; + u_int8_t tos; + const struct iphdr *iph; + + /* root is playing with raw sockets. */ + if (skb->len < sizeof(struct iphdr) || + ip_hdrlen(skb) < sizeof(struct iphdr)) + return NF_ACCEPT; + + mark = skb->mark; + iph = ip_hdr(skb); + saddr = iph->saddr; + daddr = iph->daddr; + tos = iph->tos; + + ret = nft_do_chain(ops, skb, in, out, okfn); + if (ret != NF_DROP && ret != NF_QUEUE) { + iph = ip_hdr(skb); + + if (iph->saddr != saddr || + iph->daddr != daddr || + skb->mark != mark || + iph->tos != tos) + if (ip_route_me_harder(skb, RTN_UNSPEC)) + ret = NF_DROP; + } + return ret; +} + +static struct nft_base_chain nf_chain_route_output __read_mostly = { + .chain = { + .name = "OUTPUT", + .rules = LIST_HEAD_INIT(nf_chain_route_output.chain.rules), + .flags = NFT_BASE_CHAIN | NFT_CHAIN_BUILTIN, + }, + .ops = { + .hook = nf_route_table_hook, + .owner = THIS_MODULE, + .pf = NFPROTO_IPV4, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_MANGLE, + .priv = &nf_chain_route_output.chain, + }, +}; + +static struct nft_table nf_table_route_ipv4 __read_mostly = { + .name = "route", + .chains = LIST_HEAD_INIT(nf_table_route_ipv4.chains), +}; + +static int __init nf_table_route_init(void) +{ + list_add_tail(&nf_chain_route_output.chain.list, + &nf_table_route_ipv4.chains); + return nft_register_table(&nf_table_route_ipv4, NFPROTO_IPV4); +} + +static void __exit nf_table_route_exit(void) +{ + nft_unregister_table(&nf_table_route_ipv4, NFPROTO_IPV4); +} + +module_init(nf_table_route_init); +module_exit(nf_table_route_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); +MODULE_ALIAS_NFT_TABLE(AF_INET, "route"); |