netdev - Re: [patch] sctp: fix test for end of loop

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Message-Id: <20100908.132420.179918700.davem@davemloft.net>
Date:	Wed, 08 Sep 2010 13:24:20 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	error27@...il.com
Cc:	vladislav.yasevich@...com, sri@...ibm.com, yjwei@...fujitsu.com,
	cascardo@...oscopio.com, linux-sctp@...r.kernel.org,
	netdev@...r.kernel.org, kernel-janitors@...r.kernel.org
Subject: Re: [patch] sctp: fix test for end of loop

From: Dan Carpenter <error27@...il.com>
Date: Mon, 6 Sep 2010 14:26:39 +0200

> "new_addr" is the list cursor here and it's always non-NULL.
> 
> We're trying to test if we exited because the loop ended or we hit the
> break statement.  Really testing !found is enough so long as 
> "new_asoc->peer.transport_addr_list" is not empty and I believe it never
> is empty at this point.  So this is never really a bug with the current
> code.
> 
> Signed-off-by: Dan Carpenter <error27@...il.com>

If you don't mind, I still think the code is confusing after your
patch even if the result is correct.

What do you think about the following kind of approach instead?

Thanks!

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 8b28443..3d5bbae7 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -1241,7 +1241,7 @@ static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
 				       sctp_cmd_seq_t *commands)
 {
 	struct sctp_transport *new_addr, *addr;
-	int found;
+	int ret = 1;
 
 	/* Implementor's Guide - Sectin 5.2.2
 	 * ...
@@ -1254,31 +1254,28 @@ static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
 	/* Search through all current addresses and make sure
 	 * we aren't adding any new ones.
 	 */
-	new_addr = NULL;
-	found = 0;
-
 	list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
 			transports) {
-		found = 0;
 		list_for_each_entry(addr, &asoc->peer.transport_addr_list,
 				transports) {
 			if (sctp_cmp_addr_exact(&new_addr->ipaddr,
-						&addr->ipaddr)) {
-				found = 1;
-				break;
-			}
+						&addr->ipaddr))
+				goto next;
 		}
-		if (!found)
-			break;
-	}
 
-	/* If a new address was added, ABORT the sender. */
-	if (!found && new_addr) {
+		/* 'new_addr' could not be found in the transport address
+		 * list of 'asoc', abort.
+		 */
 		sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
+		ret = 0;
+		break;
+
+	next:
+		;
 	}
 
 	/* Return success if all addresses were found. */
-	return found;
+	return ret;
 }
 
 /* Populate the verification/tie tags based on overlapping INIT
--
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