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 --- net/netfilter/xt_TPROXY.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'net/netfilter/xt_TPROXY.c') diff --git a/net/netfilter/xt_TPROXY.c b/net/netfilter/xt_TPROXY.c index dbd72cc40e42..80cb7babeb64 100644 --- a/net/netfilter/xt_TPROXY.c +++ b/net/netfilter/xt_TPROXY.c @@ -531,6 +531,11 @@ tproxy_tg6_v1(struct sk_buff *skb, const struct xt_action_param *par) static int tproxy_tg6_check(const struct xt_tgchk_param *par) { const struct ip6t_ip6 *i = par->entryinfo; + int err; + + err = nf_defrag_ipv6_enable(par->net); + if (err) + return err; if ((i->proto == IPPROTO_TCP || i->proto == IPPROTO_UDP) && !(i->invflags & IP6T_INV_PROTO)) @@ -545,6 +550,11 @@ static int tproxy_tg6_check(const struct xt_tgchk_param *par) static int tproxy_tg4_check(const struct xt_tgchk_param *par) { const struct ipt_ip *i = par->entryinfo; + int err; + + err = nf_defrag_ipv4_enable(par->net); + if (err) + return err; if ((i->proto == IPPROTO_TCP || i->proto == IPPROTO_UDP) && !(i->invflags & IPT_INV_PROTO)) @@ -596,11 +606,6 @@ static struct xt_target tproxy_tg_reg[] __read_mostly = { static int __init tproxy_tg_init(void) { - nf_defrag_ipv4_enable(); -#ifdef XT_TPROXY_HAVE_IPV6 - nf_defrag_ipv6_enable(); -#endif - return xt_register_targets(tproxy_tg_reg, ARRAY_SIZE(tproxy_tg_reg)); } -- cgit v1.2.3