Introduce polling timeout logic

This should fix FS#30361 along the way.

src/8021x

@@ -130,7 +130,7 @@ list_networks() {
 }
 
 wpa_supplicant_scan_info() {
-    local INTERFACE="$1" fields="$2" spawned_wpa=0 essids scan_wait
+    local INTERFACE="$1" fields="$2" spawned_wpa=0 essids
     # temp file used, as keeping ESSID's with spaces in their name in arrays
     # is hard, obscure and kinda nasty. This is simpler and clearer.
 
@@ -146,10 +146,7 @@ wpa_supplicant_scan_info() {
     # Wait at least 3 seconds for scan results
     sleep 3
     # Sometimes, that is not enough (FS#29946)
-    for (( scan_wait = 3; scan_wait < 10; scan_wait++ )); do
-        wpa_cli -p "$WPA_CTRL_PATH" -i "$INTERFACE" status | grep -q "wpa_state=SCANNING" || break
-        sleep 1
-    done
+    timeout_wait 7 '! wpa_cli -p "$WPA_CTRL_PATH" -i "$INTERFACE" status | grep -q "wpa_state=SCANNING"'
     wpa_cli -p "$WPA_CTRL_PATH" -i "$INTERFACE" scan_results |
         grep -v "^Selected" |
         grep -v "^bssid" |

src/connections/ethernet

@@ -14,8 +14,6 @@ report_iproute()
 }
 
 ethernet_up() {
-    local dad_timeout="${DAD_TIMEOUT:-3}"
-
     load_profile "$1"
     SYSCTL_INTERFACE="${INTERFACE/.//}"
 
@@ -34,10 +32,9 @@ ethernet_up() {
     bring_interface up "$INTERFACE"
 
 
-    if ! checkyesno "${SKIPNOCARRIER:-no}" && ip link show dev "$INTERFACE" | fgrep -q "NO-CARRIER"; then
+    if ! checkyesno "${SKIPNOCARRIER:-no}"; then
         # Some cards are plain slow to come up. Don't fail immediately.
-        sleep ${CARRIER_TIMEOUT:-2}
-        if ip link show dev "$INTERFACE" | fgrep -q "NO-CARRIER"; then
+        if ! timeout_wait "${CARRIER_TIMEOUT:-5}" '! ip link show dev "$INTERFACE" | fgrep -q "NO-CARRIER"'; then
             report_iproute "No connection"
         fi
     fi
@@ -186,12 +183,9 @@ ethernet_up() {
     if [[ -n "$IP6" ]]; then
         # Wait for DAD to finish (FS#28887)
         report_debug ethernet_up ip -6 addr show dev "$INTERFACE" tentative
-        while [[ -n "$(ip -6 addr show dev "$INTERFACE" tentative)" ]]; do
-            if (( dad_timeout-- <= 0 )); then
-                report_iproute "Duplicate Address Detection is taking too long"
-            fi
-            sleep 1
-        done
+        if ! timeout_wait "${DAD_TIMEOUT:-3}" '[[ -z "$(ip -6 addr show dev "$INTERFACE" tentative)" ]]'; then
+            report_iproute "Duplicate Address Detection is taking too long"
+        fi
 
         # Add static IPv6 routes
         if [[ -n "$ROUTES6" ]]; then

src/globals

@@ -95,6 +95,20 @@ function checkyesno() {
 }
 
 
+## Waits until a statement succeeds or a timeout occurs
+# $1: timeout in seconds
+# $2...: condition command
+function timeout_wait() {
+    local timeout="$1"
+    shift
+    while ! eval "$*"; do
+        (( timeout-- > 0 )) || return 1
+        sleep 1
+    done
+    return 0
+}
+
+
 ### Load all +x files in $HOOKS_DIR
 function load_hooks() {
     local hook

src/network

@@ -372,17 +372,14 @@ interface_is_up() {
 # $2: the interface name
 bring_interface()
 {
-    local INTERFACE="$2" timeout="${UP_TIMEOUT:-5}"
+    local INTERFACE="$2"
     case "$1" in
         up)
             if ! ( eval $IFACE_UP ); then
                 return 1
             fi
             ip link set dev "$INTERFACE" up &>/dev/null
-            while ! interface_is_up "$INTERFACE"; do
-                (( timeout-- > 0 )) || return 1
-                sleep 1
-            done
+            timeout_wait "${UP_TIMEOUT:-5}" 'interface_is_up "$INTERFACE"' || return 1
         ;;
         flush|down)
             if ! ( eval $IFACE_DOWN ); then