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/ipv4 | |
| 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/ipv4')
| -rw-r--r-- | net/ipv4/netfilter/nf_defrag_ipv4.c | 30 |
1 files changed, 24 insertions, 6 deletions
diff --git a/net/ipv4/netfilter/nf_defrag_ipv4.c b/net/ipv4/netfilter/nf_defrag_ipv4.c index ffdcc2b9360f..613432a36f0a 100644 --- a/net/ipv4/netfilter/nf_defrag_ipv4.c +++ b/net/ipv4/netfilter/nf_defrag_ipv4.c @@ -141,14 +141,16 @@ int nf_defrag_ipv4_enable(struct net *net) struct defrag4_pernet *nf_defrag = net_generic(net, defrag4_pernet_id); int err = 0; - might_sleep(); - - if (nf_defrag->users) - return 0; - mutex_lock(&defrag4_mutex); - if (nf_defrag->users) + if (nf_defrag->users == UINT_MAX) { + err = -EOVERFLOW; goto out_unlock; + } + + if (nf_defrag->users) { + nf_defrag->users++; + goto out_unlock; + } err = nf_register_net_hooks(net, ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops)); @@ -161,6 +163,22 @@ int nf_defrag_ipv4_enable(struct net *net) } EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable); +void nf_defrag_ipv4_disable(struct net *net) +{ + struct defrag4_pernet *nf_defrag = net_generic(net, defrag4_pernet_id); + + mutex_lock(&defrag4_mutex); + if (nf_defrag->users) { + nf_defrag->users--; + if (nf_defrag->users == 0) + nf_unregister_net_hooks(net, ipv4_defrag_ops, + ARRAY_SIZE(ipv4_defrag_ops)); + } + + mutex_unlock(&defrag4_mutex); +} +EXPORT_SYMBOL_GPL(nf_defrag_ipv4_disable); + module_init(nf_defrag_init); module_exit(nf_defrag_fini); |