netdev - Re: [PATCH 7/7] netfilter: nf_ct_helper: better logging for dropped packets

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Date:	Tue, 19 Feb 2013 02:11:09 +0100
From:	Pablo Neira Ayuso <pablo@...filter.org>
To:	Joe Perches <joe@...ches.com>
Cc:	netdev@...r.kernel.org, davem@...emloft.net,
	netfilter-devel@...r.kernel.org
Subject: Re: [PATCH 7/7] netfilter: nf_ct_helper: better logging for dropped
 packets

On Mon, Feb 18, 2013 at 04:22:02PM -0800, Joe Perches wrote:
> On Tue, 2013-02-19 at 01:10 +0100, pablo@...filter.org wrote:
> > This patch modifies the existing code to provide more specific
> > error message in the scope of each helper to help users to debug
> > the reason why the packet has been dropped, ie:
> []
> > diff --git a/include/net/netfilter/nf_conntrack_helper.h b/include/net/netfilter/nf_conntrack_helper.h
> []
> > @@ -100,6 +100,9 @@ struct nf_ct_helper_expectfn {
> >  	void (*expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
> >  };
> >  
> > +extern void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *,
> > +			     const char *fmt, ...);
> 
> this should be declared
> 
> __printf(3, 4)
> void nf_ct_helper_log(etc...)

Fixed, thanks.

> to get the compiler to verify format and arguments.
> 
> > @@ -210,8 +212,11 @@ static int help(struct sk_buff *skb, unsigned int protoff,
> >  						 addr_beg_p - ib_ptr,
> >  						 addr_end_p - addr_beg_p,
> >  						 exp);
> > -			else if (nf_ct_expect_related(exp) != 0)
> > +			else if (nf_ct_expect_related(exp) != 0) {
> > +				nf_ct_helper_log(skb, ct, "cannot add "
> > +							  "expectation");
> 
> do please try to avoid splitting formats
> 
> 				nf_ct_helper_log(skb, ct,
> 						 "cannot add expectation");

Done whenever possible, sometimes I see myself forced to split them to
fit 80-chars per column.

View attachment "0007-netfilter-nf_ct_helper-better-logging-for-dropped-pa.patch" of type "text/x-diff" (25269 bytes)