From 2a95183a5e0375df756efb2ca37602d71e8455f9 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 7 Dec 2017 16:28:26 +0100 Subject: [PATCH 08/11] netfilter: don't allocate space for arp/bridge hooks unless needed no need to define hook points if the family isn't supported. Because we need these hooks for either nftables, arp/ebtables or the 'call-iptables' hack we have in the bridge layer add two new dependencies, NETFILTER_FAMILY_{ARP,BRIDGE}, and have the users select them. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter.h | 4 ++++ include/net/netns/netfilter.h | 4 ++++ net/Kconfig | 1 + net/bridge/netfilter/Kconfig | 2 ++ net/ipv4/netfilter/Kconfig | 2 ++ net/netfilter/Kconfig | 6 ++++++ net/netfilter/core.c | 8 ++++++++ net/netfilter/nf_queue.c | 2 ++ 8 files changed, 29 insertions(+) --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -214,10 +214,14 @@ static inline int nf_hook(u_int8_t pf, u hook_head = rcu_dereference(net->nf.hooks_ipv6[hook]); break; case NFPROTO_ARP: +#ifdef CONFIG_NETFILTER_FAMILY_ARP hook_head = rcu_dereference(net->nf.hooks_arp[hook]); +#endif break; case NFPROTO_BRIDGE: +#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE hook_head = rcu_dereference(net->nf.hooks_bridge[hook]); +#endif break; #if IS_ENABLED(CONFIG_DECNET) case NFPROTO_DECNET: --- a/include/net/netns/netfilter.h +++ b/include/net/netns/netfilter.h @@ -19,8 +19,12 @@ struct netns_nf { #endif struct nf_hook_entries __rcu *hooks_ipv4[NF_INET_NUMHOOKS]; struct nf_hook_entries __rcu *hooks_ipv6[NF_INET_NUMHOOKS]; +#ifdef CONFIG_NETFILTER_FAMILY_ARP struct nf_hook_entries __rcu *hooks_arp[NF_ARP_NUMHOOKS]; +#endif +#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE struct nf_hook_entries __rcu *hooks_bridge[NF_INET_NUMHOOKS]; +#endif #if IS_ENABLED(CONFIG_DECNET) struct nf_hook_entries __rcu *hooks_decnet[NF_DN_NUMHOOKS]; #endif --- a/net/Kconfig +++ b/net/Kconfig @@ -182,6 +182,7 @@ config BRIDGE_NETFILTER depends on BRIDGE depends on NETFILTER && INET depends on NETFILTER_ADVANCED + select NETFILTER_FAMILY_BRIDGE default m ---help--- Enabling this option will let arptables resp. iptables see bridged --- a/net/bridge/netfilter/Kconfig +++ b/net/bridge/netfilter/Kconfig @@ -4,6 +4,7 @@ # menuconfig NF_TABLES_BRIDGE depends on BRIDGE && NETFILTER && NF_TABLES + select NETFILTER_FAMILY_BRIDGE tristate "Ethernet Bridge nf_tables support" if NF_TABLES_BRIDGE @@ -29,6 +30,7 @@ endif # NF_TABLES_BRIDGE menuconfig BRIDGE_NF_EBTABLES tristate "Ethernet Bridge tables (ebtables) support" depends on BRIDGE && NETFILTER && NETFILTER_XTABLES + select NETFILTER_FAMILY_BRIDGE help ebtables is a general, extensible frame/packet identification framework. Say 'Y' or 'M' here if you want to do Ethernet --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -72,6 +72,7 @@ endif # NF_TABLES_IPV4 config NF_TABLES_ARP tristate "ARP nf_tables support" + select NETFILTER_FAMILY_ARP help This option enables the ARP support for nf_tables. @@ -392,6 +393,7 @@ endif # IP_NF_IPTABLES config IP_NF_ARPTABLES tristate "ARP tables support" select NETFILTER_XTABLES + select NETFILTER_FAMILY_ARP depends on NETFILTER_ADVANCED help arptables is a general, extensible packet identification framework. --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -12,6 +12,12 @@ config NETFILTER_INGRESS config NETFILTER_NETLINK tristate +config NETFILTER_FAMILY_BRIDGE + bool + +config NETFILTER_FAMILY_ARP + bool + config NETFILTER_NETLINK_ACCT tristate "Netfilter NFACCT over NFNETLINK interface" depends on NETFILTER_ADVANCED --- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -267,14 +267,18 @@ static struct nf_hook_entries __rcu **nf switch (reg->pf) { case NFPROTO_NETDEV: break; +#ifdef CONFIG_NETFILTER_FAMILY_ARP case NFPROTO_ARP: if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_arp) <= reg->hooknum)) return NULL; return net->nf.hooks_arp + reg->hooknum; +#endif +#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE case NFPROTO_BRIDGE: if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_bridge) <= reg->hooknum)) return NULL; return net->nf.hooks_bridge + reg->hooknum; +#endif case NFPROTO_IPV4: if (WARN_ON_ONCE(ARRAY_SIZE(net->nf.hooks_ipv4) <= reg->hooknum)) return NULL; @@ -573,8 +577,12 @@ static int __net_init netfilter_net_init { __netfilter_net_init(net->nf.hooks_ipv4, ARRAY_SIZE(net->nf.hooks_ipv4)); __netfilter_net_init(net->nf.hooks_ipv6, ARRAY_SIZE(net->nf.hooks_ipv6)); +#ifdef CONFIG_NETFILTER_FAMILY_ARP __netfilter_net_init(net->nf.hooks_arp, ARRAY_SIZE(net->nf.hooks_arp)); +#endif +#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE __netfilter_net_init(net->nf.hooks_bridge, ARRAY_SIZE(net->nf.hooks_bridge)); +#endif #if IS_ENABLED(CONFIG_DECNET) __netfilter_net_init(net->nf.hooks_decnet, ARRAY_SIZE(net->nf.hooks_decnet)); #endif --- a/net/netfilter/nf_queue.c +++ b/net/netfilter/nf_queue.c @@ -209,8 +209,10 @@ repeat: static struct nf_hook_entries *nf_hook_entries_head(const struct net *net, u8 pf, u8 hooknum) { switch (pf) { +#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE case NFPROTO_BRIDGE: return rcu_dereference(net->nf.hooks_bridge[hooknum]); +#endif case NFPROTO_IPV4: return rcu_dereference(net->nf.hooks_ipv4[hooknum]); case NFPROTO_IPV6: