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Fix timeout handling and display RA/TA in test_monitor_tshark.sh 

- Fix script exit on timeout: handle exit code 124 from timeout command
- Add RA (Receiver Address) and TA (Transmitter Address) display in initial test capture
- Update main capture to show RA/TA instead of SA/DA for better monitor mode visibility
- Use wlan.addr1 and wlan.addr2 fields for universal compatibility across frame types

Co-authored-by: Cursor <cursoragent@cursor.com>
This commit is contained in:
Robert McMahon 2026-02-13 14:00:08 -08:00
parent 8d607a5f66
commit 1e9191f6c7
1 changed files with 29 additions and 12 deletions
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41
test_monitor_tshark.sh
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@ -84,7 +84,13 @@ echo "(This may take up to 2 seconds if no packets are present)"
# Use timeout with -c to limit packets and avoid hanging
# Capture both stdout and stderr
TEST_OUTPUT=$(timeout 2 tshark -i "$INTERFACE" -c 100 -T fields -e frame.number -e radiotap.present 2>&1 || true)
# Fields: frame.number, wlan.addr1 (RA/Receiver Address), wlan.addr2 (TA/Transmitter Address), radiotap.present
TEST_OUTPUT=$(timeout 2 tshark -i "$INTERFACE" -c 100 -T fields \
-e frame.number \
-e wlan.addr1 \
-e wlan.addr2 \
-e radiotap.present \
2>&1 || true)
TEST_EXIT_CODE=${PIPESTATUS[0]}
# Show any warnings/errors from tshark (but not packet data)
@ -94,15 +100,17 @@ echo "$TEST_OUTPUT" | grep -E "(Running as|tshark:|Warning|Error|Capturing)" ||
PACKET_LINES=$(echo "$TEST_OUTPUT" | grep -E '^[0-9]+' || true)
PACKET_COUNT=$(echo "$PACKET_LINES" | wc -l || echo "0")
# Count lines with both frame.number and radiotap.present (non-empty second field)
PLCP_COUNT=$(echo "$PACKET_LINES" | awk -F'\t' 'NF >= 2 && $1 != "" && $2 != "" && $2 != "0" && $2 != "-" {count++} END {print count+0}' || echo "0")
# Count lines with radiotap.present (4th field) set to 1
PLCP_COUNT=$(echo "$PACKET_LINES" | awk -F'\t' 'NF >= 4 && $1 != "" && $4 != "" && $4 != "0" && $4 != "-" {count++} END {print count+0}' || echo "0")
# Show sample output with better formatting
if [ "$PACKET_COUNT" -gt 0 ]; then
echo "Sample packets:"
echo "$PACKET_LINES" | head -5 | awk -F'\t' '{
radiotap = ($2 == "1" || $2 == "1.0") ? "yes" : "no"
printf " Frame %s: PLCP header (radiotap) = %s\n", $1, radiotap
ra = ($2 != "" && $2 != "-") ? $2 : "N/A"
ta = ($3 != "" && $3 != "-") ? $3 : "N/A"
radiotap = ($4 == "1" || $4 == "1.0") ? "yes" : "no"
printf " Frame %s: RA=%s, TA=%s, PLCP=%s\n", $1, ra, ta, radiotap
}'
fi
@ -123,17 +131,26 @@ echo ""
echo "Capturing packets for $DURATION seconds..."
# Run capture with timeout
# Note: timeout returns 124 when it times out (expected), so we need to handle that
set +e # Temporarily disable exit on error
CAPTURE_OUTPUT=$(timeout "$DURATION" tshark -i "$INTERFACE" -n -T fields \
-e frame.number \
-e frame.time \
-e wlan.sa \
-e wlan.da \
-e wlan.addr1 \
-e wlan.addr2 \
-e wlan.fc.type \
-e wlan.fc.subtype \
-e wlan.fc.type_subtype \
-e radiotap.present \
2>&1)
CAPTURE_EXIT_CODE=$?
set -e # Re-enable exit on error
# Exit code 124 means timeout occurred (expected), 0 means command completed normally
# Other exit codes indicate actual errors
if [ "$CAPTURE_EXIT_CODE" -ne 0 ] && [ "$CAPTURE_EXIT_CODE" -ne 124 ]; then
echo "Warning: tshark exited with code $CAPTURE_EXIT_CODE"
fi
# Force output flush
sync
@ -155,7 +172,7 @@ PACKET_LINES=$(echo "$CAPTURE_OUTPUT" | grep -E '^[0-9]+\t' || true)
FINAL_COUNT=$(echo "$PACKET_LINES" | wc -l || echo "0")
# Count packets with PLCP headers (radiotap present)
# radiotap.present field is the 8th field (after frame.number, frame.time, wlan.sa, wlan.da, wlan.fc.type, wlan.fc.subtype, wlan.fc.type_subtype)
# radiotap.present field is the 8th field (after frame.number, frame.time, wlan.ra, wlan.ta, wlan.fc.type, wlan.fc.subtype, wlan.fc.type_subtype)
PLCP_COUNT=$(echo "$PACKET_LINES" | awk -F'\t' 'NF >= 8 && $1 != "" && $8 != "" && $8 != "0" && $8 != "-" {count++} END {print count+0}' || echo "0")
# Display stats immediately - always show these
@ -172,13 +189,13 @@ echo ""
if [ -n "$PACKET_LINES" ] && [ "$FINAL_COUNT" -gt 0 ]; then
echo "Sample packets (first 10):"
echo "$PACKET_LINES" | head -10 | awk -F'\t' '{
sa = ($3 != "" && $3 != "-") ? $3 : "N/A"
da = ($4 != "" && $4 != "-") ? $4 : "N/A"
ra = ($3 != "" && $3 != "-") ? $3 : "N/A"
ta = ($4 != "" && $4 != "-") ? $4 : "N/A"
type = ($5 != "" && $5 != "-") ? $5 : "N/A"
subtype = ($6 != "" && $6 != "-") ? $6 : "N/A"
radiotap = ($8 == "1" || $8 == "1.0") ? "yes" : (($8 != "" && $8 != "-") ? "no" : "N/A")
printf " Frame %s: SA=%s, DA=%s, type=%s/%s, PLCP=%s\n",
$1, sa, da, type, subtype, radiotap
printf " Frame %s: RA=%s, TA=%s, type=%s/%s, PLCP=%s\n",
$1, ra, ta, type, subtype, radiotap
}'
echo ""
else