Detect limp home state

3 files changed, 48 insertions, 13 deletions

diff --git a/vw-nm-tools.h b/vw-nm-tools.h
index 44d5a1b..7d3c326 100644
--- a/vw-nm-tools.h
+++ b/vw-nm-tools.h
@@ -137,19 +137,38 @@ static void nm_reset(struct NM_Main *nm)
 {
 	unsigned id;
 
+	if (nm->nodes[nm->my_id].next == nm->my_id) {
+		nm->lonely_resets++;
+	}
+
 	for (id = 0; id < nm->max_nodes; id++) {
 		nm->nodes[id].next = 0xff;
 		nm->nodes[id].state = NM_MAIN_OFF;
 	}
 
 	nm->nodes[nm->my_id].next = nm->my_id;
-	nm->nodes[nm->my_id].state = NM_MAIN_LOGIN;
+	if (nm->lonely_resets >= 5) {
+		printf("Limp home detected :(\n");
+
+		nm->nodes[nm->my_id].state = NM_MAIN_LIMPHOME;
+		nm_set_timer_limphome(nm);
+	} else {
+		nm->nodes[nm->my_id].state = NM_MAIN_LOGIN;
+		nm_set_timer_now(nm);
+	}
+}
+
 
-	nm_set_timer_now(nm);
+static void nm_initreset(struct NM_Main *nm)
+{
+	nm_reset(nm);
+
+	nm->lonely_resets = 0;
 }
 
 
 
+
 static struct NM_Main* nm_alloc(unsigned node_bits, NM_ID my_id, canid_t can_base)
 {
 	struct NM_Main *nm;
@@ -173,7 +192,7 @@ static struct NM_Main* nm_alloc(unsigned node_bits, NM_ID my_id, canid_t can_bas
 	nm->my_id = my_id;
 	nm->can_base = can_base;
 
-	nm_reset(nm);
+	nm_initreset(nm);
 
 	return nm;
 }
diff --git a/vw-nm.c b/vw-nm.c
index a181fce..16631ad 100644
--- a/vw-nm.c
+++ b/vw-nm.c
@@ -79,10 +79,10 @@ static void nm_handle_can_frame(struct NM_Main *nm, struct can_frame *frame)
 	}
 
 	/* If we're currently stuck in Limp Home mode, and we can see
-	 * someone else's messages, reset and re-login.
+	 * someone else's messages: reset counters, reset NM, re-login.
 	 */
 	if (nm->nodes[nm->my_id].state == NM_MAIN_LIMPHOME) {
-		nm_reset(nm);
+		nm_initreset(nm);
 		return;
 	}
 
@@ -179,27 +179,36 @@ static void nm_buildframe(struct NM_Main *nm, struct can_frame *frame)
 
 static void nm_timeout_callback(struct NM_Main *nm, struct can_frame *frame)
 {
-	nm_buildframe(nm, frame);
-
 	switch(nm->timer_reason) {
 		case NM_TIMER_NOW:
 			/* We're due to log in */
+			nm_buildframe(nm, frame);
+
+			if ((nm->nodes[nm->my_id].state & NM_MAIN_MASK)
+				!= NM_MAIN_LOGIN) {
+
+				printf("BUG: TIMER_NOW expired in non-ON state %u\n",
+					nm->nodes[nm->my_id].state & NM_MAIN_MASK);
+			}
 
 			/* We're going to be ready, let's
 			 * change state (RCD 310 behavior)
 			 */
 			nm->nodes[nm->my_id].state = NM_MAIN_ON;
+
 			nm_set_timer_normal(nm);
 			break;
 		case NM_TIMER_NORMAL:
 			/* We're due to send our own ring message */
-			switch(nm->nodes[nm->my_id].state & NM_MAIN_MASK) {
-				case NM_MAIN_ON:
-					break;
-				default:
-					printf("BUG: TIMER_NORMAL expired in non-ON state\n");
-					break;
+			nm_buildframe(nm, frame);
+
+			if ((nm->nodes[nm->my_id].state & NM_MAIN_MASK)
+				!= NM_MAIN_ON) {
+
+				printf("BUG: TIMER_NORMAL expired in non-ON state %u\n",
+					nm->nodes[nm->my_id].state & NM_MAIN_MASK);
 			}
+
 			nm_set_timer_awol(nm);
 			break;
 		case NM_TIMER_AWOL:
@@ -208,8 +217,12 @@ static void nm_timeout_callback(struct NM_Main *nm, struct can_frame *frame)
 			 * Reset everything and start over.
 			 */
 			nm_reset(nm);
+			nm_buildframe(nm, frame);
 			break;
 		case NM_TIMER_LIMPHOME:
+			printf("Limp home timer expired again :(\n");
+
+			nm_buildframe(nm, frame);
 			nm_set_timer_limphome(nm);
 			break;
 	}
diff --git a/vw-nm.h b/vw-nm.h
index 23d0def..b9fd981 100644
--- a/vw-nm.h
+++ b/vw-nm.h
@@ -44,6 +44,9 @@ struct NM_Main {
 
 	struct timeval tv;
 	enum timer_reason timer_reason;
+
+	/* How many times have we been alone when we reset? */
+	int lonely_resets;
 };