From 834184b1f3a4635efbdfdae5fb437f109f6605fa Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 15 Nov 2016 21:36:45 +0100 Subject: netfilter: defrag: only register defrag functionality if needed nf_defrag modules for ipv4 and ipv6 export an empty stub function. Any module that needs the defragmentation hooks registered simply 'calls' this empty function to create a phony module dependency -- modprobe will then load the defrag module too. This extends netfilter ipv4/ipv6 defragmentation modules to delay the hook registration until the functionality is requested within a network namespace instead of module load time for all namespaces. Hooks are only un-registered on module unload or when a namespace that used such defrag functionality exits. We have to use struct net for this as the register hooks can be called before netns initialization here from the ipv4/ipv6 conntrack module init path. There is no unregister functionality support, defrag will always be active once it was requested inside a net namespace. The reason is that defrag has impact on nft and iptables rulesets (without defrag we might see framents). Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/ipv4/nf_defrag_ipv4.h | 3 ++- include/net/netfilter/ipv6/nf_defrag_ipv6.h | 3 ++- include/net/netns/netfilter.h | 6 ++++++ 3 files changed, 10 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/net/netfilter/ipv4/nf_defrag_ipv4.h b/include/net/netfilter/ipv4/nf_defrag_ipv4.h index f01ef208dff6..db405f70e538 100644 --- a/include/net/netfilter/ipv4/nf_defrag_ipv4.h +++ b/include/net/netfilter/ipv4/nf_defrag_ipv4.h @@ -1,6 +1,7 @@ #ifndef _NF_DEFRAG_IPV4_H #define _NF_DEFRAG_IPV4_H -void nf_defrag_ipv4_enable(void); +struct net; +int nf_defrag_ipv4_enable(struct net *); #endif /* _NF_DEFRAG_IPV4_H */ diff --git a/include/net/netfilter/ipv6/nf_defrag_ipv6.h b/include/net/netfilter/ipv6/nf_defrag_ipv6.h index ddf162f7966f..7664efe37974 100644 --- a/include/net/netfilter/ipv6/nf_defrag_ipv6.h +++ b/include/net/netfilter/ipv6/nf_defrag_ipv6.h @@ -1,7 +1,8 @@ #ifndef _NF_DEFRAG_IPV6_H #define _NF_DEFRAG_IPV6_H -void nf_defrag_ipv6_enable(void); +struct net; +int nf_defrag_ipv6_enable(struct net *); int nf_ct_frag6_init(void); void nf_ct_frag6_cleanup(void); diff --git a/include/net/netns/netfilter.h b/include/net/netns/netfilter.h index 58487b1cc99a..cea396b53a60 100644 --- a/include/net/netns/netfilter.h +++ b/include/net/netns/netfilter.h @@ -17,5 +17,11 @@ struct netns_nf { struct ctl_table_header *nf_log_dir_header; #endif struct nf_hook_entry __rcu *hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; +#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) + bool defrag_ipv4; +#endif +#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) + bool defrag_ipv6; +#endif }; #endif -- cgit v1.2.3