gprs_ns2: fix check of MTU changes for frame relay
The frame relay needs 2 byte for data packets.
Related: OS#5192
Change-Id: I02d4e81896a473aeb79ea2f2983e12324244048f
diff --git a/src/gb/gprs_ns2_fr.c b/src/gb/gprs_ns2_fr.c
index 3113b00..35e0dd9 100644
--- a/src/gb/gprs_ns2_fr.c
+++ b/src/gb/gprs_ns2_fr.c
@@ -601,14 +601,18 @@
struct priv_bind *bpriv = bind->priv;
struct gprs_ns2_nse *nse;
+ /* 2 byte DLCI header */
+ if (mtu <= 2)
+ return;
+ mtu -= 2;
+
if (mtu == bind->mtu)
return;
LOGBIND(bind, LOGL_INFO, "MTU changed from %d to %d.\n",
- bind->mtu, mtu);
+ bind->mtu + 2, mtu + 2);
- /* 2 byte DLCI header */
- bind->mtu = mtu - 2;
+ bind->mtu = mtu;
if (!bpriv->if_running)
return;