[PATCH] IPv6: only set err in rawv6_bind() when necessary

[PATCH] IPv6: only set err in rawv6_bind() when necessary

[Brian Haley]

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The variable 'err' is set in rawv6_bind() before the address check fails 
instead of after, moved inside if() statement.

Signed-off-by: Brian Haley <brian.haley@hp.com>

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diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 8a30cd8..072b28b 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -240,10 +240,10 @@ static int rawv6_bind(struct sock *sk, s
 		 */
 		v4addr = LOOPBACK4_IPV6;
 		if (!(addr_type & IPV6_ADDR_MULTICAST))	{
-			err = -EADDRNOTAVAIL;
 			if (!ipv6_chk_addr(&addr->sin6_addr, dev, 0)) {
 				if (dev)
 					dev_put(dev);
+				err = -EADDRNOTAVAIL;
 				goto out;
 			}
 		}

Re: [PATCH] IPv6: only set err in rawv6_bind() when necessary

[David Miller]

From: Brian Haley <brian.haley@hp.com>
Date: Tue, 01 Aug 2006 13:06:03 -0400

> The variable 'err' is set in rawv6_bind() before the address check fails 
> instead of after, moved inside if() statement.
> 
> Signed-off-by: Brian Haley <brian.haley@hp.com>

This is a common C idiom in the kernel:

	err = -EWHATEVER;
	if (error_condition)
		goto out;

	err = 0;
out:
	unlock_stuff();
	return err;

Every other path going from this location in rawv6_bind()
will clear err to zero, so your patch also doesn't fix any
bug.

Re: [PATCH] IPv6: only set err in rawv6_bind() when necessary

[Brian Haley]

> Every other path going from this location in rawv6_bind()
> will clear err to zero, so your patch also doesn't fix any
> bug.

I knew it didn't fix a bug, I just hadn't noticed the C idiom you 
pointed-out until I knew to look for it.  rawv6_bind() even does this, duh.

-Brian