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From: Alexander Aring <alex.aring@gmail.com>
To: Varka Bhadram <varkabhadram@gmail.com>
Cc: linux-wpan@vger.kernel.org, Varka Bhadram <varkab@cdac.in>,
	martin.townsend@xsilon.com
Subject: Re: [PATCH wpan-next] ieee802154: cleanup for lowpan_rcv
Date: Wed, 1 Oct 2014 09:03:18 +0200	[thread overview]
Message-ID: <20141001070316.GC23043@omega> (raw)
In-Reply-To: <542BA180.2030803@gmail.com>

On Wed, Oct 01, 2014 at 12:08:56PM +0530, Varka Bhadram wrote:
> Alex,
> 
> On 10/01/2014 12:03 PM, Alexander Aring wrote:
> 
> >>checking the perticular return value specifically, this patch
> >>remove these by directly including function within 'if' statement
> >>
> >>Signed-off-by: Varka Bhadram <varkab@cdac.in>
> >>---
> >>  net/ieee802154/6lowpan_rtnl.c |   21 ++++++---------------
> >>  1 file changed, 6 insertions(+), 15 deletions(-)
> >>
> >>diff --git a/net/ieee802154/6lowpan_rtnl.c b/net/ieee802154/6lowpan_rtnl.c
> >>index 4413629..657940e 100644
> >>--- a/net/ieee802154/6lowpan_rtnl.c
> >>+++ b/net/ieee802154/6lowpan_rtnl.c
> >>@@ -506,7 +506,6 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
> >>  		      struct packet_type *pt, struct net_device *orig_dev)
> >>  {
> >>  	struct ieee802154_hdr hdr;
> >>-	int ret;
> >>  	skb = skb_share_check(skb, GFP_ATOMIC);
> >>  	if (!skb)
> >>@@ -529,31 +528,23 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
> >>  		/* Pull off the 1-byte of 6lowpan header. */
> >>  		skb_pull(skb, 1);
> >>-		ret = lowpan_give_skb_to_devices(skb, NULL);
> >>-		if (ret == NET_RX_DROP)
> >>+		if (lowpan_give_skb_to_devices(skb, NULL))
> >>  			goto drop;
> >>  	} else {
> >>  		switch (skb->data[0] & 0xe0) {
> >>  		case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
> >>-			ret = process_data(skb, &hdr);
> >>-			if (ret == NET_RX_DROP)
> >>+			if (process_data(skb, &hdr))
> >>  				goto drop;
> >>  			break;
> >>  		case LOWPAN_DISPATCH_FRAG1:	/* first fragment header */
> >>-			ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAG1);
> >>-			if (ret == 1) {
> >>-				ret = process_data(skb, &hdr);
> >>-				if (ret == NET_RX_DROP)
> >>+			if (lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAG1))
> >>+				if (process_data(skb, &hdr))
> >>  					goto drop;
> >>-			}
> >>  			break;
> >>  		case LOWPAN_DISPATCH_FRAGN:	/* next fragments headers */
> >>-			ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAGN);
> >>-			if (ret == 1) {
> >>-				ret = process_data(skb, &hdr);
> >>-				if (ret == NET_RX_DROP)
> >>+			if (lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAGN))
> >>+				if (process_data(skb, &hdr))
> >>  					goto drop;
> >>-			}
> >>  			break;
> >>  		default:
> >>  			break;
> >Mainly I would ack this, I detect no change. But this handling is
> >currently complete broken and Martin already work on this. [0]
> >
> >I will not apply it. First fix the broken error handling, then you can
> >send cleanups for everything in 6LoWPAN receive handling.
> >
> Where is error handling is broken...?

everywhere at this position, see what Martin does and the review notes.

There is a mixed return values of NET_RX_FOO and -EFOO and I am pretty
sure, we double freeing sk_buff's when error occurs. Martin will make
this behaviour easier and easy to understand. At the moment it's a mess.

- Alex

[0] http://marc.info/?l=linux-bluetooth&m=141079021702990&w=2

      reply	other threads:[~2014-10-01  7:03 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-01  6:01 [PATCH wpan-next] ieee802154: cleanup for lowpan_rcv Varka Bhadram
2014-10-01  6:33 ` Alexander Aring
2014-10-01  6:38   ` Varka Bhadram
2014-10-01  7:03     ` Alexander Aring [this message]

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