From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Florian Westphal <fw@strlen.de>
Cc: netfilter-devel@vger.kernel.org
Subject: Re: [PATCH nf-next,RFC 08/10] netfilter: move NF_QUEUE handling away from core
Date: Thu, 13 Oct 2016 17:04:23 +0200 [thread overview]
Message-ID: <20161013150423.GB1301@salvia> (raw)
In-Reply-To: <20161013123821.GC14002@breakpoint.cc>
On Thu, Oct 13, 2016 at 02:38:21PM +0200, Florian Westphal wrote:
> Pablo Neira Ayuso <pablo@netfilter.org> wrote:
[...]
> > diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
> > index de4fa03f46f3..7040842c34f4 100644
> > --- a/net/ipv4/netfilter/ip_tables.c
> > +++ b/net/ipv4/netfilter/ip_tables.c
> > @@ -29,6 +29,7 @@
> > #include <linux/netfilter/x_tables.h>
> > #include <linux/netfilter_ipv4/ip_tables.h>
> > #include <net/netfilter/nf_log.h>
> > +#include <net/netfilter/nf_queue.h>
> > #include "../../netfilter/xt_repldata.h"
> >
> > MODULE_LICENSE("GPL");
> > @@ -329,6 +330,9 @@ ipt_do_table(struct sk_buff *skb,
> > /* Pop from stack? */
> > if (v != XT_RETURN) {
> > verdict = (unsigned int)(-v) - 1;
> > + if (verdict == NF_QUEUE)
> > + verdict = nf_queue(skb, state,
> > + 0, false);
>
> Any reason why this is needed?
> AFAICS xt_NFQUEUE will never return NF_QUEUE after this patch.
-j QUEUE uses the standard target to return NF_QUEUE. This is very
primitive way to queue packets to userspace queue 0 via nf_queue, but
still may break. I can place this under unlikely() as these days
people should be using NFQUEUE instead.
> > diff --git a/net/netfilter/core.c b/net/netfilter/core.c
> > index 2b3b2f8e39c4..9ae2febd86e3 100644
> > --- a/net/netfilter/core.c
> > +++ b/net/netfilter/core.c
> > @@ -309,6 +309,7 @@ unsigned int nf_iterate(struct sk_buff *skb,
> > unsigned int verdict;
> >
> > while (*entryp) {
> > + RCU_INIT_POINTER(state->hook_entries, *entryp);
> > repeat:
> > verdict = (*entryp)->ops.hook((*entryp)->ops.priv, skb, state);
> > if (verdict != NF_ACCEPT) {
> > @@ -331,9 +332,8 @@ int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state)
> > int ret;
> >
> > entry = rcu_dereference(state->hook_entries);
> > -next_hook:
> > verdict = nf_iterate(skb, state, &entry);
> > - switch (verdict & NF_VERDICT_MASK) {
> > + switch (verdict) {
>
> This looks buggy, verdict might encode errno for NF_DROP case.
>
> What you could do is:
>
> switch (verdict) {
> case NF_ACCEPT:
> /* something */
> break;
> case NF_STOLEN:
> break;
> case NF_DROP: /* fallthrough */
> default: /* drop with error? */
> kfree_skb(skb);
> errno = ...
> }
Right, will fix this, thanks.
next prev parent reply other threads:[~2016-10-13 15:05 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-13 12:02 [PATCH nf-next,RFC 00/10] Netfilter core updates Pablo Neira Ayuso
2016-10-13 12:02 ` [PATCH nf-next,RFC 01/10] netfilter: get rid of useless debugging from core Pablo Neira Ayuso
2016-10-13 12:02 ` [PATCH nf-next,RFC 02/10] netfilter: remove comments that predate rcu days Pablo Neira Ayuso
2016-10-13 12:02 ` [PATCH nf-next,RFC 03/10] netfilter: bridge: kill NF_HOOK_THRESH() and state->tresh Pablo Neira Ayuso
2016-10-13 12:25 ` Florian Westphal
2016-10-13 15:01 ` Pablo Neira Ayuso
2016-10-13 15:10 ` Florian Westphal
2016-10-13 15:21 ` Pablo Neira Ayuso
2016-10-13 15:25 ` Florian Westphal
2016-10-13 12:02 ` [PATCH nf-next,RFC 04/10] netfilter: deprecate NF_STOP Pablo Neira Ayuso
2016-10-13 12:02 ` [PATCH nf-next,RFC 05/10] netfilter: x_tables: move hook state into xt_action_param structure Pablo Neira Ayuso
2016-10-13 12:02 ` [PATCH nf-next,RFC 06/10] netfilter: nf_tables: use hook state from " Pablo Neira Ayuso
2016-10-13 12:02 ` [PATCH nf-next,RFC 07/10] netfilter: use switch() to handle verdict cases from nf_hook_slow() Pablo Neira Ayuso
2016-10-13 12:02 ` [PATCH nf-next,RFC 08/10] netfilter: move NF_QUEUE handling away from core Pablo Neira Ayuso
2016-10-13 12:38 ` Florian Westphal
2016-10-13 15:04 ` Pablo Neira Ayuso [this message]
2016-10-13 15:09 ` Florian Westphal
2016-10-14 8:06 ` Liping Zhang
2016-10-14 9:53 ` Pablo Neira Ayuso
2016-10-14 10:28 ` Pablo Neira Ayuso
2016-10-14 15:38 ` Florian Westphal
2016-10-14 16:47 ` Pablo Neira Ayuso
2016-10-14 17:22 ` Pablo Neira Ayuso
2016-10-13 12:02 ` [PATCH nf-next,RFC 09/10] netfilter: merge nf_iterate() into nf_hook_slow() Pablo Neira Ayuso
2016-10-13 12:02 ` [PATCH nf-next,RFC 10/10] netfilter: inline nf_hook_slow() and rename it to nf_hook_iterate() Pablo Neira Ayuso
-- strict thread matches above, loose matches on Subject: below --
2016-10-13 12:11 [PATCH nf-next,RFC 00/10] Netfilter core updates Pablo Neira Ayuso
2016-10-13 12:12 ` [PATCH nf-next,RFC 08/10] netfilter: move NF_QUEUE handling away from core Pablo Neira Ayuso
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