| /* |
| * Copyright (c) 2008 Patrick McHardy <kaber@trash.net> |
| * Copyright (c) 2012 Pablo Neira Ayuso <pablo@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/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/netfilter/nf_tables_ipv4.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 nf_hook_state *state) |
| { |
| unsigned int ret; |
| struct nft_pktinfo pkt; |
| 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; |
| |
| nft_set_pktinfo_ipv4(&pkt, ops, skb, state); |
| |
| mark = skb->mark; |
| iph = ip_hdr(skb); |
| saddr = iph->saddr; |
| daddr = iph->daddr; |
| tos = iph->tos; |
| |
| ret = nft_do_chain(&pkt, ops); |
| 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 const struct nf_chain_type nft_chain_route_ipv4 = { |
| .name = "route", |
| .type = NFT_CHAIN_T_ROUTE, |
| .family = NFPROTO_IPV4, |
| .owner = THIS_MODULE, |
| .hook_mask = (1 << NF_INET_LOCAL_OUT), |
| .hooks = { |
| [NF_INET_LOCAL_OUT] = nf_route_table_hook, |
| }, |
| }; |
| |
| static int __init nft_chain_route_init(void) |
| { |
| return nft_register_chain_type(&nft_chain_route_ipv4); |
| } |
| |
| static void __exit nft_chain_route_exit(void) |
| { |
| nft_unregister_chain_type(&nft_chain_route_ipv4); |
| } |
| |
| module_init(nft_chain_route_init); |
| module_exit(nft_chain_route_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); |
| MODULE_ALIAS_NFT_CHAIN(AF_INET, "route"); |