Improve tshark error handling and packet counting

- Add -q flag to suppress tshark summary output
- Handle exit code 1 (field availability issues) as non-fatal
- Better filter out tshark status messages from packet counting
- Improve packet line detection to exclude status messages

Co-authored-by: Cursor <cursoragent@cursor.com>

test_monitor_tshark.sh

@@ -133,8 +133,11 @@ echo "Capturing packets for $DURATION seconds..."
 
 # Run capture with timeout
 # Note: timeout returns 124 when it times out (expected), so we need to handle that
+# Also, wlan.ra/wlan.ta may not be available for all frame types, which can cause tshark to exit with code 1
+# We'll capture both stdout and stderr, but continue even if tshark exits with an error
 set +e  # Temporarily disable exit on error
-CAPTURE_OUTPUT=$(timeout "$DURATION" tshark -i "$INTERFACE" -n -T fields \
+# Use -q to suppress packet count output, and continue even if some fields are missing
+CAPTURE_OUTPUT=$(timeout "$DURATION" tshark -q -i "$INTERFACE" -n -T fields \
     -e frame.number \
     -e frame.time \
     -e wlan.ra \
@@ -148,8 +151,9 @@ CAPTURE_EXIT_CODE=$?
 set -e  # Re-enable exit on error
 
 # Exit code 124 means timeout occurred (expected), 0 means command completed normally
+# Exit code 1 might mean some fields weren't available for some frames, but we still got data
 # Other exit codes indicate actual errors
-if [ "$CAPTURE_EXIT_CODE" -ne 0 ] && [ "$CAPTURE_EXIT_CODE" -ne 124 ]; then
+if [ "$CAPTURE_EXIT_CODE" -ne 0 ] && [ "$CAPTURE_EXIT_CODE" -ne 124 ] && [ "$CAPTURE_EXIT_CODE" -ne 1 ]; then
     echo "Warning: tshark exited with code $CAPTURE_EXIT_CODE"
 fi
 
@@ -168,8 +172,9 @@ if [ -n "$WARNINGS" ]; then
 fi
 
 # Count total packets captured (lines starting with a number followed by tab)
-# Filter out lines like "100 packets captured" which don't have tabs
-PACKET_LINES=$(echo "$CAPTURE_OUTPUT" | grep -E '^[0-9]+\t' || true)
+# Filter out tshark status messages like "100 packets captured" or "Capturing on..."
+# Only count lines that look like actual packet data: number, tab, then more fields
+PACKET_LINES=$(echo "$CAPTURE_OUTPUT" | grep -E '^[0-9]+\t' | grep -v -E '(packets captured|Capturing on|Running as)' || true)
 FINAL_COUNT=$(echo "$PACKET_LINES" | wc -l || echo "0")
 
 # Count packets with PLCP headers (radiotap present)