diff options
| author | Florian Westphal <fw@strlen.de> | 2021-04-21 09:45:40 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2021-04-26 03:20:07 +0200 |
| commit | de8c12110a130337c8e7e7b8250de0580e644dee (patch) | |
| tree | 6cfc80f96c19a60753a15a99e906996e2f0b499c /net/ipv6 | |
| parent | e0bb96db96f8ca94349344a2ea7bebc6f8cefdae (diff) | |
netfilter: disable defrag once its no longer needed
When I changed defrag hooks to no longer get registered by default I
intentionally made it so that registration can only be un-done by unloading
the nf_defrag_ipv4/6 module.
In hindsight this was too conservative; there is no reason to keep defrag
on while there is no feature dependency anymore.
Moreover, this won't work if user isn't allowed to remove nf_defrag module.
This adds the disable() functions for both ipv4 and ipv6 and calls them
from conntrack, TPROXY and the xtables socket module.
ipvs isn't converted here, it will behave as before this patch and
will need module removal.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/netfilter/nf_defrag_ipv6_hooks.c | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c index 402dc4ca9504..e8a59d8bf2ad 100644 --- a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c +++ b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c @@ -137,14 +137,16 @@ int nf_defrag_ipv6_enable(struct net *net) struct nft_ct_frag6_pernet *nf_frag = net_generic(net, nf_frag_pernet_id); int err = 0; - might_sleep(); - - if (nf_frag->users) - return 0; - mutex_lock(&defrag6_mutex); - if (nf_frag->users) + if (nf_frag->users == UINT_MAX) { + err = -EOVERFLOW; + goto out_unlock; + } + + if (nf_frag->users) { + nf_frag->users++; goto out_unlock; + } err = nf_register_net_hooks(net, ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops)); @@ -157,6 +159,21 @@ int nf_defrag_ipv6_enable(struct net *net) } EXPORT_SYMBOL_GPL(nf_defrag_ipv6_enable); +void nf_defrag_ipv6_disable(struct net *net) +{ + struct nft_ct_frag6_pernet *nf_frag = net_generic(net, nf_frag_pernet_id); + + mutex_lock(&defrag6_mutex); + if (nf_frag->users) { + nf_frag->users--; + if (nf_frag->users == 0) + nf_unregister_net_hooks(net, ipv6_defrag_ops, + ARRAY_SIZE(ipv6_defrag_ops)); + } + mutex_unlock(&defrag6_mutex); +} +EXPORT_SYMBOL_GPL(nf_defrag_ipv6_disable); + module_init(nf_defrag_init); module_exit(nf_defrag_fini); |