From 3fc21533d00d791b9f38b0af170c626c17caefc1 Mon Sep 17 00:00:00 2001
From: Adrien Banlin <a.banlin@alphalink.fr>
Date: Mon, 19 Jun 2023 11:46:09 +0200
Subject: [PATCH] hotplug: load default/networking for hotplug itfs

* ifup@.service is be able to show debug and verbose logs if set in
  the default file. (-d -v)

* ifupdown2-hotplug load default before processing (excluding
  EXCLUDE_INTERFACES and adding -v -d --syslog on an init.d
  system.
---
 debian/ifup@.service     | 18 +++++++++++++-----
 debian/ifupdown2-hotplug | 38 ++++++++++++++++++++++++++++++++------
 2 files changed, 45 insertions(+), 11 deletions(-)

diff --git a/debian/ifup@.service b/debian/ifup@.service
index 6f8e3c7b..8f065193 100644
--- a/debian/ifup@.service
+++ b/debian/ifup@.service
@@ -11,19 +11,27 @@ IgnoreOnIsolate=yes
 [Service]
 # avoid stopping on shutdown via stopping system-ifup.slice
 Slice=system.slice
+Environment=HOTPLUG_ARGS=
 Environment=LOCKFILE=/run/network/.lock
+EnvironmentFile=-/etc/default/networking
 ExecStart=/bin/sh -ec "( \
+    /bin/test \"$VERBOSE\" = \"yes\" && EXTRA_ARGS=-v; \
+    /bin/test \"$DEBUG\" = \"yes\" && EXTRA_ARGS=\"$EXTRA_ARGS -d\"; \
     flock 9; \
     if $(/sbin/ifquery -L 9 -l --allow=hotplug 2>/dev/null | grep -w -q \"^%I$\"); then \
-        exec /sbin/ifup %I -L 9 --systemd; \
-    else \
-        echo 'Interface %I not hotplug'; \
-        exit 1; \
+        exec /sbin/ifup $EXTRA_ARGS $HOTPLUG_ARGS %I -L 9 --systemd; \
     fi; \
+    exit 1; \
 ) 9>$LOCKFILE"
 ExecStop=/bin/sh -ec "( \
+    /bin/test \"$VERBOSE\" = \"yes\" && EXTRA_ARGS=-v; \
+    /bin/test \"$DEBUG\" = \"yes\" && EXTRA_ARGS=\"$EXTRA_ARGS -d\"; \
     flock 9; \
-    exec /sbin/ifdown %I -L 9 --systemd; \
+    exec /sbin/ifdown $EXTRA_ARGS %I -L 9 --systemd; \
 ) 9>$LOCKFILE"
 RemainAfterExit=true
 TimeoutStartSec=2min
+
+# remove log duplications
+StandardOutput=null
+StandardError=null
diff --git a/debian/ifupdown2-hotplug b/debian/ifupdown2-hotplug
index 3496b256..2b6b869b 100755
--- a/debian/ifupdown2-hotplug
+++ b/debian/ifupdown2-hotplug
@@ -49,10 +49,22 @@ wait_for_interface() {
     done
 }
 
+process_exclusions() {
+    set -- $EXCLUDE_INTERFACES
+    exclusions=""
+    for d; do
+	exclusions="-X $d $exclusions"
+    done
+    echo $exclusions
+}
+
 net_ifup() {
+    . /etc/default/networking 2>/dev/null || true
+
+    exclusions=$(process_exclusions)
 
-    # exit if the interface is not configured as allow-hotplug (querying does not require a lock)
-    if ! $(/sbin/ifquery --allow=hotplug -l 2>/dev/null | grep -w -q "^$INTERFACE$"); then
+    # exit if the interface is not configured as allow-hotplug or excluded (querying does not require a lock)
+    if ! $(/sbin/ifquery --allow=hotplug -l $exclusions 2>/dev/null | grep -w -q "^$INTERFACE$"); then
 	exit 0
     fi
 
@@ -60,11 +72,16 @@ net_ifup() {
 	exec systemctl --no-block start $(systemd-escape --template ifup@.service $INTERFACE)
     fi
 
+    EXTRA_ARGS=
+    [ "$VERBOSE" = yes ] && EXTRA_ARGS=-v
+    [ "$DEBUG"   = yes ] && EXTRA_ARGS="$EXTRA_ARGS -d"
+    [ "$SYSLOG"  = yes ] && EXTRA_ARGS="$EXTRA_ARGS --syslog"
+
     # Take the lock and wait for lo before exec ifup.
     (
 	flock 9
 	wait_for_interface lo
-	exec ifup $INTERFACE -L 9
+	exec ifup $EXTRA_ARGS $HOTPLUG_ARGS -L 9 $INTERFACE
     ) 9>$LOCKFILE
 }
 
@@ -76,15 +93,24 @@ net_ifdown() {
 	exit 0
     fi
 
-    # exit if the interface is not configured as allow-hotplug (querying does not require a lock)
-    if ! $(/sbin/ifquery --allow=hotplug -l 2>/dev/null | grep -w -q "^$INTERFACE$"); then
+    . /etc/default/networking 2>/dev/null || true
+
+    exclusions=$(process_exclusions)
+
+    # exit if the interface is not configured as allow-hotplug or excluded (querying does not require a lock)
+    if ! $(/sbin/ifquery --allow=hotplug -l $exclusions 2>/dev/null | grep -w -q "^$INTERFACE$"); then
 	exit 0
     fi
 
+    EXTRA_ARGS=
+    [ "$VERBOSE" = yes ] && EXTRA_ARGS=-v
+    [ "$DEBUG"   = yes ] && EXTRA_ARGS="$EXTRA_ARGS -d"
+    [ "$SYSLOG"  = yes ] && EXTRA_ARGS="$EXTRA_ARGS --syslog"
+
     # Take the lock and exec ifdown.
     (
 	flock 9
-	exec ifdown $INTERFACE -L 9
+	exec ifdown $EXTRA_ARGS $INTERFACE -L 9
     ) 9>$LOCKFILE
 }