[PATCH] batctl: event: don't print timestamp prefix for skipped events

The timestamp is printed before the event is parsed. Each parse function
can still decide to skip the event without printing anything In these cases
a bare "1234.567890: " fragment without newline remains on the line and the
next event is appended to it, corrupting the output stream.

Format the timestamp into a prefix string instead and let the parse
functions print it together with their first line.

Fixes: 5d7850e3582e ("batctl: Add command to monitor for netlink events")
Signed-off-by: Sven Eckelmann <[email protected]>
---
 event.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/event.c b/event.c
index e061c2c..4a1085d 100644
--- a/event.c
+++ b/event.c
@@ -114,7 +114,7 @@ static const int tp_meter_mandatory[] = {
 	BATADV_ATTR_TPMETER_RESULT,
 };
 
-static void event_parse_tp_meter(struct nlattr **attrs)
+static void event_parse_tp_meter(struct nlattr **attrs, const char *prefix)
 {
 	const char *result_str;
 	uint32_t cookie;
@@ -155,10 +155,10 @@ static void event_parse_tp_meter(struct nlattr **attrs)
 		break;
 	}
 
-	printf("tp_meter 0x%08x: %s\n", cookie, result_str);
+	printf("%stp_meter 0x%08x: %s\n", prefix, cookie, result_str);
 }
 
-static void event_parse_set_mesh(struct nlattr **attrs)
+static void event_parse_set_mesh(struct nlattr **attrs, const char *prefix)
 {
 	static const int mesh_mandatory[] = {
 		BATADV_ATTR_MESH_IFINDEX,
@@ -183,7 +183,7 @@ static void event_parse_set_mesh(struct nlattr **attrs)
 			return;
 	}
 
-	printf("%s: set mesh:\n", meshif_name);
+	printf("%s%s: set mesh:\n", prefix, meshif_name);
 
 	if (attrs[BATADV_ATTR_AGGREGATED_OGMS_ENABLED])
 		printf("* aggregated_ogms %s\n",
@@ -287,7 +287,7 @@ static void event_parse_set_mesh(struct nlattr **attrs)
 		       nla_get_u32(attrs[BATADV_ATTR_ORIG_INTERVAL]));
 }
 
-static void event_parse_set_hardif(struct nlattr **attrs)
+static void event_parse_set_hardif(struct nlattr **attrs, const char *prefix)
 {
 	static const int hardif_mandatory[] = {
 		BATADV_ATTR_MESH_IFINDEX,
@@ -325,7 +325,7 @@ static void event_parse_set_hardif(struct nlattr **attrs)
 			return;
 	}
 
-	printf("%s (%s): set hardif:\n", meshif_name, hardif_name);
+	printf("%s%s (%s): set hardif:\n", prefix, meshif_name, hardif_name);
 
 	if (attrs[BATADV_ATTR_HOP_PENALTY])
 		printf("* hop_penalty %u\n",
@@ -344,7 +344,7 @@ static void event_parse_set_hardif(struct nlattr **attrs)
 	}
 }
 
-static void event_parse_set_vlan(struct nlattr **attrs)
+static void event_parse_set_vlan(struct nlattr **attrs, const char *prefix)
 {
 	static const int vlan_mandatory[] = {
 		BATADV_ATTR_MESH_IFINDEX,
@@ -372,7 +372,7 @@ static void event_parse_set_vlan(struct nlattr **attrs)
 
 	vid = nla_get_u16(attrs[BATADV_ATTR_VLANID]);
 
-	printf("%s (vid %u): set vlan:\n", meshif_name, vid);
+	printf("%s%s (vid %u): set vlan:\n", prefix, meshif_name, vid);
 
 	if (attrs[BATADV_ATTR_AP_ISOLATION_ENABLED])
 		printf("* ap_isolation %s\n",
@@ -403,6 +403,7 @@ static int event_parse(struct nl_msg *msg, void *arg)
 	struct event_args *event_args = arg;
 	unsigned long long timestamp;
 	struct genlmsghdr *ghdr;
+	char prefix[32] = "";
 
 	if (!genlmsg_valid_hdr(nlh, 0))
 		return NL_OK;
@@ -417,24 +418,25 @@ static int event_parse(struct nl_msg *msg, void *arg)
 
 	if (event_args->mode != EVENT_TIME_NO) {
 		timestamp = get_timestamp(event_args);
-		printf("%llu.%06llu: ", timestamp / 1000000, timestamp % 1000000);
+		snprintf(prefix, sizeof(prefix), "%llu.%06llu: ",
+			 timestamp / 1000000, timestamp % 1000000);
 	}
 
 	switch (ghdr->cmd) {
 	case BATADV_CMD_TP_METER:
-		event_parse_tp_meter(attrs);
+		event_parse_tp_meter(attrs, prefix);
 		break;
 	case BATADV_CMD_SET_MESH:
-		event_parse_set_mesh(attrs);
+		event_parse_set_mesh(attrs, prefix);
 		break;
 	case BATADV_CMD_SET_HARDIF:
-		event_parse_set_hardif(attrs);
+		event_parse_set_hardif(attrs, prefix);
 		break;
 	case BATADV_CMD_SET_VLAN:
-		event_parse_set_vlan(attrs);
+		event_parse_set_vlan(attrs, prefix);
 		break;
 	default:
-		printf("Received unknown event %u\n", ghdr->cmd);
+		printf("%sReceived unknown event %u\n", prefix, ghdr->cmd);
 		break;
 	}
 

---
base-commit: e93995999e80513db80eba200ea682b5b15556af
change-id: 20260704-bugfixes-event-cac8fef8b398

Best regards,
--  
Sven Eckelmann <[email protected]>