diff options
Diffstat (limited to 'net/bridge/netfilter/nf_tables_bridge.c')
| -rw-r--r-- | net/bridge/netfilter/nf_tables_bridge.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/net/bridge/netfilter/nf_tables_bridge.c b/net/bridge/netfilter/nf_tables_bridge.c new file mode 100644 index 000000000..a343e6244 --- /dev/null +++ b/net/bridge/netfilter/nf_tables_bridge.c @@ -0,0 +1,190 @@ +/* + * 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, + const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + if (nft_bridge_iphdr_validate(skb)) + nft_set_pktinfo_ipv4(pkt, ops, skb, state); + else + nft_set_pktinfo(pkt, ops, skb, state); +} + +static inline void nft_bridge_set_pktinfo_ipv6(struct nft_pktinfo *pkt, + const struct nf_hook_ops *ops, + 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, ops, skb, state) == 0) + return; +#endif + nft_set_pktinfo(pkt, ops, skb, state); +} + +static unsigned int +nft_do_chain_bridge(const struct nf_hook_ops *ops, + 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, ops, skb, state); + break; + case htons(ETH_P_IPV6): + nft_bridge_set_pktinfo_ipv6(&pkt, ops, skb, state); + break; + default: + nft_set_pktinfo(&pkt, ops, skb, state); + break; + } + + return nft_do_chain(&pkt, ops); +} + +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); |