GSM timers: User reasonable defaults; don't save if equal default

A number of the GSM timers (including T3109) had no reasonable
default values if not specified in the VTY / config file.  Together
with unconditional writing to the config file, this created
config files with a persistent setting for important timers as '0'.

To make things worse, many of our example cofig files suffered from the
same problem.

Let's avoid this from happening by
* having reasonable defaults if nothing specified in the config file
* conditionally savingg timers only if they differ from default
* reject any timer values that state zero during start-up (see previous
  commit)

Change-Id: Iaac0bfca423852b61d8b9eb1438157ef00d0d8c8
Closes: OS#2380

2 files changed, 25 insertions, 13 deletions

diff --git a/openbsc/src/libbsc/bsc_vty.c b/openbsc/src/libbsc/bsc_vty.c
index 6472e9d80..b8352ce1e 100644
--- a/openbsc/src/libbsc/bsc_vty.c
+++ b/openbsc/src/libbsc/bsc_vty.c
@@ -787,6 +787,11 @@ static int config_write_bts(struct vty *v)
 	return CMD_SUCCESS;
 }
 
+/* small helper macro for conditional dumping of timer */
+#define VTY_OUT_TIMER(number)	\
+	if (gsmnet->T##number != GSM_T##number##_DEFAULT)	\
+		vty_out(vty, " timer t"#number" %u%s", gsmnet->T##number, VTY_NEWLINE)
+
 static int config_write_net(struct vty *vty)
 {
 	struct gsm_network *gsmnet = gsmnet_from_vty(vty);
@@ -820,18 +825,18 @@ static int config_write_net(struct vty *vty)
 		gsmnet->handover.pwr_hysteresis, VTY_NEWLINE);
 	vty_out(vty, " handover maximum distance %u%s",
 		gsmnet->handover.max_distance, VTY_NEWLINE);
-	vty_out(vty, " timer t3101 %u%s", gsmnet->T3101, VTY_NEWLINE);
-	vty_out(vty, " timer t3103 %u%s", gsmnet->T3103, VTY_NEWLINE);
-	vty_out(vty, " timer t3105 %u%s", gsmnet->T3105, VTY_NEWLINE);
-	vty_out(vty, " timer t3107 %u%s", gsmnet->T3107, VTY_NEWLINE);
-	vty_out(vty, " timer t3109 %u%s", gsmnet->T3109, VTY_NEWLINE);
-	vty_out(vty, " timer t3111 %u%s", gsmnet->T3111, VTY_NEWLINE);
-	vty_out(vty, " timer t3113 %u%s", gsmnet->T3113, VTY_NEWLINE);
-	vty_out(vty, " timer t3115 %u%s", gsmnet->T3115, VTY_NEWLINE);
-	vty_out(vty, " timer t3117 %u%s", gsmnet->T3117, VTY_NEWLINE);
-	vty_out(vty, " timer t3119 %u%s", gsmnet->T3119, VTY_NEWLINE);
-	vty_out(vty, " timer t3122 %u%s", gsmnet->T3122, VTY_NEWLINE);
-	vty_out(vty, " timer t3141 %u%s", gsmnet->T3141, VTY_NEWLINE);
+	VTY_OUT_TIMER(3101);
+	VTY_OUT_TIMER(3103);
+	VTY_OUT_TIMER(3105);
+	VTY_OUT_TIMER(3107);
+	VTY_OUT_TIMER(3109);
+	VTY_OUT_TIMER(3111);
+	VTY_OUT_TIMER(3113);
+	VTY_OUT_TIMER(3115);
+	VTY_OUT_TIMER(3117);
+	VTY_OUT_TIMER(3119);
+	VTY_OUT_TIMER(3122);
+	VTY_OUT_TIMER(3141);
 	vty_out(vty, " dyn_ts_allow_tch_f %d%s",
 		gsmnet->dyn_ts_allow_tch_f ? 1 : 0, VTY_NEWLINE);
 	vty_out(vty, " subscriber-keep-in-ram %d%s",
diff --git a/openbsc/src/libbsc/net_init.c b/openbsc/src/libbsc/net_init.c
index 4dfc258a5..9d5431964 100644
--- a/openbsc/src/libbsc/net_init.c
+++ b/openbsc/src/libbsc/net_init.c
@@ -44,10 +44,17 @@ struct gsm_network *bsc_network_init(void *ctx,
 	net->num_bts = 0;
 	net->reject_cause = GSM48_REJECT_ROAMING_NOT_ALLOWED;
 	net->T3101 = GSM_T3101_DEFAULT;
+	net->T3103 = GSM_T3103_DEFAULT;
 	net->T3105 = GSM_T3105_DEFAULT;
+	net->T3107 = GSM_T3107_DEFAULT;
+	net->T3109 = GSM_T3109_DEFAULT;
+	net->T3111 = GSM_T3111_DEFAULT;
 	net->T3113 = GSM_T3113_DEFAULT;
+	net->T3115 = GSM_T3115_DEFAULT;
+	net->T3117 = GSM_T3117_DEFAULT;
+	net->T3119 = GSM_T3119_DEFAULT;
 	net->T3122 = GSM_T3122_DEFAULT;
-	/* FIXME: initialize all other timers! */
+	net->T3141 = GSM_T3141_DEFAULT;
 
 	/* default set of handover parameters */
 	net->handover.win_rxlev_avg = 10;