From mboxrd@z Thu Jan  1 00:00:00 1970
From: Florian Westphal <fw@strlen.de>
Subject: Re: Possible bug in __nfnl_handle_msg
Date: Fri, 27 Jun 2014 00:14:29 +0200
Message-ID: <20140626221429.GA23488@breakpoint.cc>
References: <20140626205023.GA32347@joerntop.localnet>
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Cc: netfilter-devel@vger.kernel.org
To: Joern Heissler <nfdevel@joern.heissler.de>
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Joern Heissler <nfdevel@joern.heissler.de> wrote:
> Hi,
> 
> I'm trying to use libnetfilter_log and I think I might have found a bug :)

Looks like nfnl_handle_packet doesn't handle control messages (like NLMSG_DONE).

I don't understand libnfnetlink here, specifically why
nfnl_handle_packet exists in first place, seems like it was superseded
by nfnl_process(), so I *thought* a quick fix is

--- a/src/libnetfilter_log.c
+++ b/src/libnetfilter_log.c
@@ -322,7 +322,7 @@ int nflog_callback_register(struct nflog_g_handle *gh, nflog_callback *cb,
 
 int nflog_handle_packet(struct nflog_handle *h, char *buf, int len)
 {
-       return nfnl_handle_packet(h->nfnlh, buf, len);
+       return nfnl_process(h->nfnlh, (unsigned char *) buf, len);
 }

But that breaks probably every user of the library since
nfnl_process() expects cb to return NFNL_CB_CONTINUE (== 1)
and not 0 (which makes _process top iterating).

But 0 is what the examples use :-(

'someone' has to touch libnfnetlink it seems...