Expire USB approval deduplication across daemon and watcher restarts

Author: acrogenesis

bin/omarchy-usb-authorization-event

@@ -6,7 +6,43 @@
 set -euo pipefail
 
 case "${USBGUARD_IPC_SIGNAL:-}" in
-IPC.Connected)
+IPC.Connected) ;;
+Device.PolicyApplied)
+  # PresenceChanged precedes policy evaluation, even for trusted devices.
+  [[ ${USBGUARD_DEVICE_TARGET_NEW:-} == "block" ]] || exit 0
+  ;;
+Device.PresenceChanged)
+  [[ ${USBGUARD_DEVICE_EVENT:-} == "Remove" ]] || exit 0
+  ;;
+*) exit 0 ;;
+esac
+
+requests="$HOME/.local/state/omarchy/usb-authorization/requests"
+mkdir -p "$requests"
+chmod 700 "${requests%/*}" "$requests"
+exec 9>"$requests/.lock"
+
+request_generation() {
+  local daemon_id
+
+  # USBGuard reuses device IDs after restarting. Include both the daemon
+  # invocation and watcher lifetime so old prompts cannot suppress new ones.
+  daemon_id=$(systemctl show usbguard.service --property=InvocationID --value) || return 1
+  [[ $daemon_id =~ ^[0-9a-f]{32}$ ]] || return 1
+  printf '%s:%s' "${OMARCHY_USB_AUTHORIZATION_WATCH_ID:-standalone}" "$daemon_id"
+}
+
+if [[ $USBGUARD_IPC_SIGNAL == "IPC.Connected" ]]; then
+  flock 9
+  generation=$(request_generation) || exit 1
+  for pending in "$requests"/request-*.json; do
+    [[ -f $pending ]] || continue
+    if ! jq -e --arg generation "$generation" '.generation == $generation' "$pending" >/dev/null 2>&1; then
+      rm -f "$pending"
+    fi
+  done
+  flock -u 9
+
   # USBGuard scans present devices before accepting IPC connections. Repeat
   # this on every reconnect: temporary approvals disappear on daemon restart.
   blocked=$(usbguard list-devices --blocked) || exit 1
@@ -20,21 +56,14 @@ IPC.Connected)
     fi
   done <<<"$blocked"
   exit 0
-  ;;
-Device.PolicyApplied)
-  # PresenceChanged precedes policy evaluation, even for trusted devices.
-  # PolicyApplied also covers block-to-block and allow-to-block transitions.
-  [[ ${USBGUARD_DEVICE_TARGET_NEW:-} == "block" ]] || exit 0
-  ;;
-*) exit 0 ;;
-esac
+fi
 
 [[ ${USBGUARD_DEVICE_ID:-} =~ ^[0-9]+$ ]] || exit 0
 [[ -n ${USBGUARD_DEVICE_RULE:-} ]] || exit 0
 
-requests="$HOME/.local/state/omarchy/usb-authorization/requests"
-mkdir -p "$requests"
-chmod 700 "${requests%/*}" "$requests"
+# A removed device's final target may be allow even though a blocked request
+# remains. Its identity attributes are unchanged; normalize the target.
+USBGUARD_DEVICE_RULE="block ${USBGUARD_DEVICE_RULE#* }"
 
 # The token is safe to carry through the presentation launcher's command
 # string. The device-controlled rule itself stays in a mode-0600 JSON file and
@@ -43,12 +72,24 @@ token="request-$(printf '%s\0%s' "$USBGUARD_DEVICE_ID" "$USBGUARD_DEVICE_RULE" |
 request="$requests/$token.json"
 # watch executes handlers concurrently. A reconnect scan and a policy event
 # can refer to the same device; publish only one pending request.
-exec 9>"$requests/.lock"
+if [[ $USBGUARD_IPC_SIGNAL == "Device.PresenceChanged" ]]; then
+  flock 9
+  blocked=$(usbguard list-devices --blocked) || exit 1
+  # A delayed removal event must not erase a request for a reappeared device.
+  if ! grep -Fqx -- "$USBGUARD_DEVICE_ID: $USBGUARD_DEVICE_RULE" <<<"$blocked"; then
+    rm -f "$request"
+  fi
+  exit 0
+fi
+
 # Keep retrying without needing another USB event. Handlers belong to the
 # watcher service and are stopped with the graphical session.
 while true; do
   flock 9
-  [[ ! -e $request ]] || exit 0
+  generation=$(request_generation) || exit 1
+  if [[ -f $request ]] && jq -e --arg generation "$generation" '.generation == $generation' "$request" >/dev/null 2>&1; then
+    exit 0
+  fi
 
   # Discard events overtaken by another policy decision or device replacement.
   blocked=$(usbguard list-devices --blocked) || exit 1
@@ -75,7 +116,8 @@ while true; do
   jq -n \
     --arg id "$USBGUARD_DEVICE_ID" \
     --arg rule "$USBGUARD_DEVICE_RULE" \
-    '{id: $id, rule: $rule}' >"$temporary"
+    --arg generation "$generation" \
+    '{id: $id, rule: $rule, generation: $generation}' >"$temporary"
   chmod 600 "$temporary"
   mv -f "$temporary" "$request"
 

bin/omarchy-usb-authorization-watch

@@ -5,6 +5,11 @@
 
 set -euo pipefail
 
+# Starting a new graphical-session watcher must offer fresh prompts even if
+# their old notification actions were dismissed and aged out of history.
+OMARCHY_USB_AUTHORIZATION_WATCH_ID=$(cat /proc/sys/kernel/random/uuid)
+export OMARCHY_USB_AUTHORIZATION_WATCH_ID
+
 event_handler="$OMARCHY_PATH/bin/omarchy-usb-authorization-event"
 
 # The handler scans blocked devices on IPC.Connected, including reconnects

test/shell.d/usb-authorization-test.sh

@@ -51,7 +51,9 @@ STUB
 cat >"$stub_bin/systemctl" <<'STUB'
 #!/bin/bash
 printf 'systemctl <%s>\n' "$*" >>"$CALLS"
-if [[ $* == "is-enabled --quiet usbguard.service" ]]; then
+if [[ $* == "show usbguard.service --property=InvocationID --value" ]]; then
+  printf '%s\n' "${TEST_DAEMON_INVOCATION:-11111111111111111111111111111111}"
+elif [[ $* == "is-enabled --quiet usbguard.service" ]]; then
   exit 1
 fi
 STUB
@@ -97,6 +99,9 @@ list-rules)
   printf 'usbguard' >>"$CALLS"
   printf ' <%s>' "$@" >>"$CALLS"
   printf '\n' >>"$CALLS"
+  if [[ $1 == "watch" && -n ${TEST_WATCH_ID_FILE:-} ]]; then
+    printf '%s\n' "$OMARCHY_USB_AUTHORIZATION_WATCH_ID" >"$TEST_WATCH_ID_FILE"
+  fi
   if [[ $1 == "allow-device" && ${!#} == block* ]]; then
     [[ ${APPROVAL_EXIT_FAIL:-0} == 0 ]] || exit 1
     if [[ ${APPROVAL_SILENT_FAIL:-0} == 0 ]]; then
@@ -506,6 +511,63 @@ wait "$scan_pid"
   fail "overlapping scan and policy events must not duplicate pending prompts"
 pass "USB reconnect scans and policy events deduplicate pending requests"
 
+# Dismissing/canceling a notification leaves its request, even after the shell
+# discards the archived action. Reusing the ID after daemon restart must prompt.
+notification_count=$(grep -c '^notification' "$calls")
+export TEST_DAEMON_INVOCATION=22222222222222222222222222222222
+USBGUARD_IPC_SIGNAL=IPC.Connected "$ROOT/bin/omarchy-usb-authorization-event" &
+scan_pid=$!
+USBGUARD_IPC_SIGNAL=Device.PolicyApplied \
+  USBGUARD_DEVICE_ID=17 \
+  USBGUARD_DEVICE_TARGET_NEW=block \
+  USBGUARD_DEVICE_RULE="$malicious_rule" \
+  "$ROOT/bin/omarchy-usb-authorization-event"
+wait "$scan_pid"
+[[ $(grep -c '^notification' "$calls") == $((notification_count + 1)) ]] ||
+  fail "reused IDs must get exactly one new notification after daemon restart"
+[[ -f $request ]] || fail "the recovered notification must have a reviewable request"
+
+# Starting another watcher/session also expires old notification deduplication.
+notification_count=$(grep -c '^notification' "$calls")
+export OMARCHY_USB_AUTHORIZATION_WATCH_ID=new-session
+USBGUARD_IPC_SIGNAL=IPC.Connected "$ROOT/bin/omarchy-usb-authorization-event"
+[[ $(grep -c '^notification' "$calls") == $((notification_count + 1)) ]] ||
+  fail "a new watcher must recover an orphaned approval action"
+USBGUARD_IPC_SIGNAL=IPC.Connected "$ROOT/bin/omarchy-usb-authorization-event"
+[[ $(grep -c '^notification' "$calls") == $((notification_count + 1)) ]] ||
+  fail "same-generation scans must still deduplicate"
+
+# A removal that arrives late must not erase a new connection's request.
+USBGUARD_IPC_SIGNAL=Device.PresenceChanged USBGUARD_DEVICE_EVENT=Remove \
+  USBGUARD_DEVICE_ID=17 USBGUARD_DEVICE_RULE="$malicious_rule" \
+  "$ROOT/bin/omarchy-usb-authorization-event"
+[[ -f $request ]] || fail "delayed removal must preserve a currently blocked device's request"
+BLOCKED_DEVICE_PRESENT=0 \
+  USBGUARD_IPC_SIGNAL=Device.PresenceChanged USBGUARD_DEVICE_EVENT=Remove \
+  USBGUARD_DEVICE_ID=17 USBGUARD_DEVICE_RULE="${malicious_rule/#block/allow}" \
+  "$ROOT/bin/omarchy-usb-authorization-event"
+[[ ! -e $request ]] || fail "device removal must clean up its pending request"
+USBGUARD_IPC_SIGNAL=IPC.Connected "$ROOT/bin/omarchy-usb-authorization-event"
+[[ $(grep -c '^notification' "$calls") == $((notification_count + 2)) ]] ||
+  fail "a reappeared device must receive a fresh notification"
+
+# Upgrade from requests written before generations existed, and remove stale
+# requests for devices no longer in the inventory.
+jq 'del(.generation)' "$request" >"$scratch/legacy-request"
+mv "$scratch/legacy-request" "$request"
+legacy_orphan="${request%/*}/request-$(printf '%064d' 0).json"
+printf '{"id":"99","rule":"block id 0000:0000"}\n' >"$legacy_orphan"
+USBGUARD_IPC_SIGNAL=IPC.Connected "$ROOT/bin/omarchy-usb-authorization-event"
+[[ $(grep -c '^notification' "$calls") == $((notification_count + 3)) ]] ||
+  fail "legacy request markers must not suppress notification recovery"
+[[ ! -e $legacy_orphan ]] || fail "reconnect must clean up old-generation orphan requests"
+
+TEST_WATCH_ID_FILE="$scratch/watch-one" "$ROOT/bin/omarchy-usb-authorization-watch"
+TEST_WATCH_ID_FILE="$scratch/watch-two" "$ROOT/bin/omarchy-usb-authorization-watch"
+[[ -s $scratch/watch-one && $(<"$scratch/watch-one") != "$(<"$scratch/watch-two")" ]] ||
+  fail "each watcher must export a fresh lifetime identifier"
+pass "USB prompts recover across daemon and session generations and device removal"
+
 GUM_CHOICE='Allow once' "$ROOT/bin/omarchy-usb-authorization-review" "$token" >"$scratch/review-once-output"
 grep -Fqx "usbguard <allow-device> <$malicious_rule>" "$calls" || fail "review can allow the exact device once"
 [[ ! -e $request ]] || fail "a completed review consumes its request"