commit 5e6d679df39e5e20b55ef24754a4e6310c9bcad2
author Jacob Erlbeck <jerlbeck@sysmocom.de> Mon Oct 14 22:06:48 2013 +0200
committer Holger Hans Peter Freyther <holger@moiji-mobile.com> Tue Oct 15 10:20:34 2013 +0200
tree 762c75f088dd6b287f4cc2765657d085b43ed45e
parent 96550e03214697be2d1b303a690ef10ea3bb12b7

gb: Fix gprs_ns_rx_reset to not create NS-VC duplicates

Under special circumstances (see below) receiving a NS-RESET leads to
duplicated NS-VC entries.

This happens when the source port of a NS-VC changes to a new one
that has already been used by another NS-VC.

This patch changes gprs_ns_rx_reset() to check for this case and to
use the existing NS-VC object. The NS-VC object that was associated
with the source address before is detached from this source but kept
in the NS-VC list so that it can be reattached when a correspondent
NS-RESET is received later on. Meanwhile it will have a cleared link
layer address which will not match a real link info.

A new counter NS_CTR_REPLACED is incremented each time when the NS-VC
object is replacing another one. A new signal S_NS_REPLACED is added
which gets dispatched in this case, too.

Another new counter NS_CTR_NSEI_CHG is incremented each time when the
NSEI of a NS-VC object (with fixed NSVCI) changes.

Ticket: OW#874
Sponsored-by: On-Waves ehf

tests/gb/gprs_ns_test.ok

diff --git a/tests/gb/gprs_ns_test.ok b/tests/gb/gprs_ns_test.ok
index 01b1bc9..7be84ef 100644
--- a/tests/gb/gprs_ns_test.ok
+++ b/tests/gb/gprs_ns_test.ok
@@ -91,12 +91,14 @@
 Current NS-VCIs:
     VCI 0x3344, NSEI 0x1122, peer 0x01020304:3333
     VCI 0x1122, NSEI 0x3344, peer 0x01020304:4444
+         NS-VC changed NSEI        : 1
 
 --- Peer port 3333, RESET, VCI is changed back ---
 
 PROCESSING RESET from 0x01020304:3333
 02 00 81 01 01 82 11 22 04 82 11 22 
 
+==> got signal NS_REPLACED: 0x1122/1.2.3.4:4444 -> 0x3344/1.2.3.4:3333
 ==> got signal NS_RESET, NS-VC 0x1122/1.2.3.4:3333
 RESPONSE, msg length 9
 03 01 82 11 22 04 82 11 22 
@@ -107,8 +109,10 @@
 result (RESET) = 9
 
 Current NS-VCIs:
+    VCI 0x3344, NSEI 0x1122, peer 0x00000000:0
     VCI 0x1122, NSEI 0x1122, peer 0x01020304:3333
-    VCI 0x1122, NSEI 0x3344, peer 0x01020304:4444
+         NS-VC replaced other count: 1
+         NS-VC changed NSEI        : 2
 
 --- Peer port 4444, RESET, NSEI is changed back ---
 
@@ -125,8 +129,10 @@
 result (RESET) = 9
 
 Current NS-VCIs:
-    VCI 0x1122, NSEI 0x1122, peer 0x01020304:3333
+    VCI 0x3344, NSEI 0x1122, peer 0x00000000:0
     VCI 0x1122, NSEI 0x1122, peer 0x01020304:4444
+         NS-VC replaced other count: 1
+         NS-VC changed NSEI        : 2
 
 ===== NS protocol test END