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- /*
- * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
- * Copyright (c) 2013 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.
- *
- * Development of this code funded by Astaro AG (http://www.astaro.com/)
- */
- #include <linux/init.h>
- #include <linux/module.h>
- #include <linux/netfilter_bridge.h>
- #include <net/netfilter/nf_tables.h>
- #include <net/netfilter/nf_tables_bridge.h>
- #include <linux/ip.h>
- #include <linux/ipv6.h>
- #include <net/netfilter/nf_tables_ipv4.h>
- #include <net/netfilter/nf_tables_ipv6.h>
- int nft_bridge_iphdr_validate(struct sk_buff *skb)
- {
- struct iphdr *iph;
- u32 len;
- if (!pskb_may_pull(skb, sizeof(struct iphdr)))
- return 0;
- iph = ip_hdr(skb);
- if (iph->ihl < 5 || iph->version != 4)
- return 0;
- len = ntohs(iph->tot_len);
- if (skb->len < len)
- return 0;
- else if (len < (iph->ihl*4))
- return 0;
- if (!pskb_may_pull(skb, iph->ihl*4))
- return 0;
- return 1;
- }
- EXPORT_SYMBOL_GPL(nft_bridge_iphdr_validate);
- int nft_bridge_ip6hdr_validate(struct sk_buff *skb)
- {
- struct ipv6hdr *hdr;
- u32 pkt_len;
- if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
- return 0;
- hdr = ipv6_hdr(skb);
- if (hdr->version != 6)
- return 0;
- pkt_len = ntohs(hdr->payload_len);
- if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
- return 0;
- return 1;
- }
- EXPORT_SYMBOL_GPL(nft_bridge_ip6hdr_validate);
- static inline void nft_bridge_set_pktinfo_ipv4(struct nft_pktinfo *pkt,
- struct sk_buff *skb,
- const struct nf_hook_state *state)
- {
- if (nft_bridge_iphdr_validate(skb))
- nft_set_pktinfo_ipv4(pkt, skb, state);
- else
- nft_set_pktinfo(pkt, skb, state);
- }
- static inline void nft_bridge_set_pktinfo_ipv6(struct nft_pktinfo *pkt,
- struct sk_buff *skb,
- const struct nf_hook_state *state)
- {
- #if IS_ENABLED(CONFIG_IPV6)
- if (nft_bridge_ip6hdr_validate(skb) &&
- nft_set_pktinfo_ipv6(pkt, skb, state) == 0)
- return;
- #endif
- nft_set_pktinfo(pkt, skb, state);
- }
- static unsigned int
- nft_do_chain_bridge(void *priv,
- struct sk_buff *skb,
- const struct nf_hook_state *state)
- {
- struct nft_pktinfo pkt;
- switch (eth_hdr(skb)->h_proto) {
- case htons(ETH_P_IP):
- nft_bridge_set_pktinfo_ipv4(&pkt, skb, state);
- break;
- case htons(ETH_P_IPV6):
- nft_bridge_set_pktinfo_ipv6(&pkt, skb, state);
- break;
- default:
- nft_set_pktinfo(&pkt, skb, state);
- break;
- }
- return nft_do_chain(&pkt, priv);
- }
- static struct nft_af_info nft_af_bridge __read_mostly = {
- .family = NFPROTO_BRIDGE,
- .nhooks = NF_BR_NUMHOOKS,
- .owner = THIS_MODULE,
- .nops = 1,
- .hooks = {
- [NF_BR_PRE_ROUTING] = nft_do_chain_bridge,
- [NF_BR_LOCAL_IN] = nft_do_chain_bridge,
- [NF_BR_FORWARD] = nft_do_chain_bridge,
- [NF_BR_LOCAL_OUT] = nft_do_chain_bridge,
- [NF_BR_POST_ROUTING] = nft_do_chain_bridge,
- },
- };
- static int nf_tables_bridge_init_net(struct net *net)
- {
- net->nft.bridge = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL);
- if (net->nft.bridge == NULL)
- return -ENOMEM;
- memcpy(net->nft.bridge, &nft_af_bridge, sizeof(nft_af_bridge));
- if (nft_register_afinfo(net, net->nft.bridge) < 0)
- goto err;
- return 0;
- err:
- kfree(net->nft.bridge);
- return -ENOMEM;
- }
- static void nf_tables_bridge_exit_net(struct net *net)
- {
- nft_unregister_afinfo(net->nft.bridge);
- kfree(net->nft.bridge);
- }
- static struct pernet_operations nf_tables_bridge_net_ops = {
- .init = nf_tables_bridge_init_net,
- .exit = nf_tables_bridge_exit_net,
- };
- static const struct nf_chain_type filter_bridge = {
- .name = "filter",
- .type = NFT_CHAIN_T_DEFAULT,
- .family = NFPROTO_BRIDGE,
- .owner = THIS_MODULE,
- .hook_mask = (1 << NF_BR_PRE_ROUTING) |
- (1 << NF_BR_LOCAL_IN) |
- (1 << NF_BR_FORWARD) |
- (1 << NF_BR_LOCAL_OUT) |
- (1 << NF_BR_POST_ROUTING),
- };
- static int __init nf_tables_bridge_init(void)
- {
- int ret;
- nft_register_chain_type(&filter_bridge);
- ret = register_pernet_subsys(&nf_tables_bridge_net_ops);
- if (ret < 0)
- nft_unregister_chain_type(&filter_bridge);
- return ret;
- }
- static void __exit nf_tables_bridge_exit(void)
- {
- unregister_pernet_subsys(&nf_tables_bridge_net_ops);
- nft_unregister_chain_type(&filter_bridge);
- }
- module_init(nf_tables_bridge_init);
- module_exit(nf_tables_bridge_exit);
- MODULE_LICENSE("GPL");
- MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
- MODULE_ALIAS_NFT_FAMILY(AF_BRIDGE);
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