diff options
Diffstat (limited to 'net/netfilter/nft_chain_filter.c')
| -rw-r--r-- | net/netfilter/nft_chain_filter.c | 456 |
1 files changed, 456 insertions, 0 deletions
diff --git a/net/netfilter/nft_chain_filter.c b/net/netfilter/nft_chain_filter.c new file mode 100644 index 000000000..274b6f7e6 --- /dev/null +++ b/net/netfilter/nft_chain_filter.c @@ -0,0 +1,456 @@ +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/netdevice.h> +#include <net/net_namespace.h> +#include <net/netfilter/nf_tables.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_ipv6.h> +#include <linux/netfilter_bridge.h> +#include <linux/netfilter_arp.h> +#include <net/netfilter/nf_tables_ipv4.h> +#include <net/netfilter/nf_tables_ipv6.h> + +#ifdef CONFIG_NF_TABLES_IPV4 +static unsigned int nft_do_chain_ipv4(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct nft_pktinfo pkt; + + nft_set_pktinfo(&pkt, skb, state); + nft_set_pktinfo_ipv4(&pkt); + + return nft_do_chain(&pkt, priv); +} + +static const struct nft_chain_type nft_chain_filter_ipv4 = { + .name = "filter", + .type = NFT_CHAIN_T_DEFAULT, + .family = NFPROTO_IPV4, + .hook_mask = (1 << NF_INET_LOCAL_IN) | + (1 << NF_INET_LOCAL_OUT) | + (1 << NF_INET_FORWARD) | + (1 << NF_INET_PRE_ROUTING) | + (1 << NF_INET_POST_ROUTING), + .hooks = { + [NF_INET_LOCAL_IN] = nft_do_chain_ipv4, + [NF_INET_LOCAL_OUT] = nft_do_chain_ipv4, + [NF_INET_FORWARD] = nft_do_chain_ipv4, + [NF_INET_PRE_ROUTING] = nft_do_chain_ipv4, + [NF_INET_POST_ROUTING] = nft_do_chain_ipv4, + }, +}; + +static void nft_chain_filter_ipv4_init(void) +{ + nft_register_chain_type(&nft_chain_filter_ipv4); +} +static void nft_chain_filter_ipv4_fini(void) +{ + nft_unregister_chain_type(&nft_chain_filter_ipv4); +} + +#else +static inline void nft_chain_filter_ipv4_init(void) {} +static inline void nft_chain_filter_ipv4_fini(void) {} +#endif /* CONFIG_NF_TABLES_IPV4 */ + +#ifdef CONFIG_NF_TABLES_ARP +static unsigned int nft_do_chain_arp(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct nft_pktinfo pkt; + + nft_set_pktinfo(&pkt, skb, state); + nft_set_pktinfo_unspec(&pkt); + + return nft_do_chain(&pkt, priv); +} + +static const struct nft_chain_type nft_chain_filter_arp = { + .name = "filter", + .type = NFT_CHAIN_T_DEFAULT, + .family = NFPROTO_ARP, + .owner = THIS_MODULE, + .hook_mask = (1 << NF_ARP_IN) | + (1 << NF_ARP_OUT), + .hooks = { + [NF_ARP_IN] = nft_do_chain_arp, + [NF_ARP_OUT] = nft_do_chain_arp, + }, +}; + +static void nft_chain_filter_arp_init(void) +{ + nft_register_chain_type(&nft_chain_filter_arp); +} + +static void nft_chain_filter_arp_fini(void) +{ + nft_unregister_chain_type(&nft_chain_filter_arp); +} +#else +static inline void nft_chain_filter_arp_init(void) {} +static inline void nft_chain_filter_arp_fini(void) {} +#endif /* CONFIG_NF_TABLES_ARP */ + +#ifdef CONFIG_NF_TABLES_IPV6 +static unsigned int nft_do_chain_ipv6(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct nft_pktinfo pkt; + + nft_set_pktinfo(&pkt, skb, state); + nft_set_pktinfo_ipv6(&pkt); + + return nft_do_chain(&pkt, priv); +} + +static const struct nft_chain_type nft_chain_filter_ipv6 = { + .name = "filter", + .type = NFT_CHAIN_T_DEFAULT, + .family = NFPROTO_IPV6, + .hook_mask = (1 << NF_INET_LOCAL_IN) | + (1 << NF_INET_LOCAL_OUT) | + (1 << NF_INET_FORWARD) | + (1 << NF_INET_PRE_ROUTING) | + (1 << NF_INET_POST_ROUTING), + .hooks = { + [NF_INET_LOCAL_IN] = nft_do_chain_ipv6, + [NF_INET_LOCAL_OUT] = nft_do_chain_ipv6, + [NF_INET_FORWARD] = nft_do_chain_ipv6, + [NF_INET_PRE_ROUTING] = nft_do_chain_ipv6, + [NF_INET_POST_ROUTING] = nft_do_chain_ipv6, + }, +}; + +static void nft_chain_filter_ipv6_init(void) +{ + nft_register_chain_type(&nft_chain_filter_ipv6); +} + +static void nft_chain_filter_ipv6_fini(void) +{ + nft_unregister_chain_type(&nft_chain_filter_ipv6); +} +#else +static inline void nft_chain_filter_ipv6_init(void) {} +static inline void nft_chain_filter_ipv6_fini(void) {} +#endif /* CONFIG_NF_TABLES_IPV6 */ + +#ifdef CONFIG_NF_TABLES_INET +static unsigned int nft_do_chain_inet(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct nft_pktinfo pkt; + + nft_set_pktinfo(&pkt, skb, state); + + switch (state->pf) { + case NFPROTO_IPV4: + nft_set_pktinfo_ipv4(&pkt); + break; + case NFPROTO_IPV6: + nft_set_pktinfo_ipv6(&pkt); + break; + default: + break; + } + + return nft_do_chain(&pkt, priv); +} + +static unsigned int nft_do_chain_inet_ingress(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct nf_hook_state ingress_state = *state; + struct nft_pktinfo pkt; + + switch (skb->protocol) { + case htons(ETH_P_IP): + /* Original hook is NFPROTO_NETDEV and NF_NETDEV_INGRESS. */ + ingress_state.pf = NFPROTO_IPV4; + ingress_state.hook = NF_INET_INGRESS; + nft_set_pktinfo(&pkt, skb, &ingress_state); + + if (nft_set_pktinfo_ipv4_ingress(&pkt) < 0) + return NF_DROP; + break; + case htons(ETH_P_IPV6): + ingress_state.pf = NFPROTO_IPV6; + ingress_state.hook = NF_INET_INGRESS; + nft_set_pktinfo(&pkt, skb, &ingress_state); + + if (nft_set_pktinfo_ipv6_ingress(&pkt) < 0) + return NF_DROP; + break; + default: + return NF_ACCEPT; + } + + return nft_do_chain(&pkt, priv); +} + +static const struct nft_chain_type nft_chain_filter_inet = { + .name = "filter", + .type = NFT_CHAIN_T_DEFAULT, + .family = NFPROTO_INET, + .hook_mask = (1 << NF_INET_INGRESS) | + (1 << NF_INET_LOCAL_IN) | + (1 << NF_INET_LOCAL_OUT) | + (1 << NF_INET_FORWARD) | + (1 << NF_INET_PRE_ROUTING) | + (1 << NF_INET_POST_ROUTING), + .hooks = { + [NF_INET_INGRESS] = nft_do_chain_inet_ingress, + [NF_INET_LOCAL_IN] = nft_do_chain_inet, + [NF_INET_LOCAL_OUT] = nft_do_chain_inet, + [NF_INET_FORWARD] = nft_do_chain_inet, + [NF_INET_PRE_ROUTING] = nft_do_chain_inet, + [NF_INET_POST_ROUTING] = nft_do_chain_inet, + }, +}; + +static void nft_chain_filter_inet_init(void) +{ + nft_register_chain_type(&nft_chain_filter_inet); +} + +static void nft_chain_filter_inet_fini(void) +{ + nft_unregister_chain_type(&nft_chain_filter_inet); +} +#else +static inline void nft_chain_filter_inet_init(void) {} +static inline void nft_chain_filter_inet_fini(void) {} +#endif /* CONFIG_NF_TABLES_IPV6 */ + +#if IS_ENABLED(CONFIG_NF_TABLES_BRIDGE) +static unsigned int +nft_do_chain_bridge(void *priv, + struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct nft_pktinfo pkt; + + nft_set_pktinfo(&pkt, skb, state); + + switch (eth_hdr(skb)->h_proto) { + case htons(ETH_P_IP): + nft_set_pktinfo_ipv4_validate(&pkt); + break; + case htons(ETH_P_IPV6): + nft_set_pktinfo_ipv6_validate(&pkt); + break; + default: + nft_set_pktinfo_unspec(&pkt); + break; + } + + return nft_do_chain(&pkt, priv); +} + +static const struct nft_chain_type nft_chain_filter_bridge = { + .name = "filter", + .type = NFT_CHAIN_T_DEFAULT, + .family = NFPROTO_BRIDGE, + .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), + .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 void nft_chain_filter_bridge_init(void) +{ + nft_register_chain_type(&nft_chain_filter_bridge); +} + +static void nft_chain_filter_bridge_fini(void) +{ + nft_unregister_chain_type(&nft_chain_filter_bridge); +} +#else +static inline void nft_chain_filter_bridge_init(void) {} +static inline void nft_chain_filter_bridge_fini(void) {} +#endif /* CONFIG_NF_TABLES_BRIDGE */ + +#ifdef CONFIG_NF_TABLES_NETDEV +static unsigned int nft_do_chain_netdev(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct nft_pktinfo pkt; + + nft_set_pktinfo(&pkt, skb, state); + + switch (skb->protocol) { + case htons(ETH_P_IP): + nft_set_pktinfo_ipv4_validate(&pkt); + break; + case htons(ETH_P_IPV6): + nft_set_pktinfo_ipv6_validate(&pkt); + break; + default: + nft_set_pktinfo_unspec(&pkt); + break; + } + + return nft_do_chain(&pkt, priv); +} + +static const struct nft_chain_type nft_chain_filter_netdev = { + .name = "filter", + .type = NFT_CHAIN_T_DEFAULT, + .family = NFPROTO_NETDEV, + .hook_mask = (1 << NF_NETDEV_INGRESS) | + (1 << NF_NETDEV_EGRESS), + .hooks = { + [NF_NETDEV_INGRESS] = nft_do_chain_netdev, + [NF_NETDEV_EGRESS] = nft_do_chain_netdev, + }, +}; + +static void nft_netdev_event(unsigned long event, struct net_device *dev, + struct nft_ctx *ctx) +{ + struct nft_base_chain *basechain = nft_base_chain(ctx->chain); + struct nft_hook *hook, *found = NULL; + int n = 0; + + if (event != NETDEV_UNREGISTER) + return; + + list_for_each_entry(hook, &basechain->hook_list, list) { + if (hook->ops.dev == dev) + found = hook; + + n++; + } + if (!found) + return; + + if (n > 1) { + nf_unregister_net_hook(ctx->net, &found->ops); + list_del_rcu(&found->list); + kfree_rcu(found, rcu); + return; + } + + /* UNREGISTER events are also happening on netns exit. + * + * Although nf_tables core releases all tables/chains, only this event + * handler provides guarantee that hook->ops.dev is still accessible, + * so we cannot skip exiting net namespaces. + */ + __nft_release_basechain(ctx); +} + +static int nf_tables_netdev_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct nft_base_chain *basechain; + struct nftables_pernet *nft_net; + struct nft_chain *chain, *nr; + struct nft_table *table; + struct nft_ctx ctx = { + .net = dev_net(dev), + }; + + if (event != NETDEV_UNREGISTER && + event != NETDEV_CHANGENAME) + return NOTIFY_DONE; + + nft_net = nft_pernet(ctx.net); + mutex_lock(&nft_net->commit_mutex); + list_for_each_entry(table, &nft_net->tables, list) { + if (table->family != NFPROTO_NETDEV && + table->family != NFPROTO_INET) + continue; + + ctx.family = table->family; + ctx.table = table; + list_for_each_entry_safe(chain, nr, &table->chains, list) { + if (!nft_is_base_chain(chain)) + continue; + + basechain = nft_base_chain(chain); + if (table->family == NFPROTO_INET && + basechain->ops.hooknum != NF_INET_INGRESS) + continue; + + ctx.chain = chain; + nft_netdev_event(event, dev, &ctx); + } + } + mutex_unlock(&nft_net->commit_mutex); + + return NOTIFY_DONE; +} + +static struct notifier_block nf_tables_netdev_notifier = { + .notifier_call = nf_tables_netdev_event, +}; + +static int nft_chain_filter_netdev_init(void) +{ + int err; + + nft_register_chain_type(&nft_chain_filter_netdev); + + err = register_netdevice_notifier(&nf_tables_netdev_notifier); + if (err) + goto err_register_netdevice_notifier; + + return 0; + +err_register_netdevice_notifier: + nft_unregister_chain_type(&nft_chain_filter_netdev); + + return err; +} + +static void nft_chain_filter_netdev_fini(void) +{ + nft_unregister_chain_type(&nft_chain_filter_netdev); + unregister_netdevice_notifier(&nf_tables_netdev_notifier); +} +#else +static inline int nft_chain_filter_netdev_init(void) { return 0; } +static inline void nft_chain_filter_netdev_fini(void) {} +#endif /* CONFIG_NF_TABLES_NETDEV */ + +int __init nft_chain_filter_init(void) +{ + int err; + + err = nft_chain_filter_netdev_init(); + if (err < 0) + return err; + + nft_chain_filter_ipv4_init(); + nft_chain_filter_ipv6_init(); + nft_chain_filter_arp_init(); + nft_chain_filter_inet_init(); + nft_chain_filter_bridge_init(); + + return 0; +} + +void nft_chain_filter_fini(void) +{ + nft_chain_filter_bridge_fini(); + nft_chain_filter_inet_fini(); + nft_chain_filter_arp_fini(); + nft_chain_filter_ipv6_fini(); + nft_chain_filter_ipv4_fini(); + nft_chain_filter_netdev_fini(); +} |