Hostname stability

board/common/rootfs/usr/libexec/infix/hostname

@@ -0,0 +1,74 @@
+#!/bin/sh
+# Deterministically set system hostname from /etc/hostname.d/
+#
+# Highest numbered file wins (lexicographic sort, 90-dhcp > 50-configured > 10-default)
+#
+# Priority scheme:
+#   10-default       - Bootstrap/factory default (%h-%m format)
+#   50-configured    - From confd /system/hostname
+#   90-dhcp-<iface>  - From DHCP clietn on interface (highest priority)
+
+HOSTNAME_D="/etc/hostname.d"
+
+# Ensure directory exists
+mkdir -p "$HOSTNAME_D"
+
+# Find the highest priority file (reverse sort, take first)
+hostname_file=$(ls -1 "$HOSTNAME_D" 2>/dev/null | sort -r | head -1)
+
+if [ -z "$hostname_file" ]; then
+    logger -it confd "No hostname sources found in $HOSTNAME_D"
+    exit 1
+fi
+
+# Read hostname from the file (first line only, strip whitespace)
+new_hostname=$(cat "$HOSTNAME_D/$hostname_file" | head -1 | tr -d '\n\r\t ')
+if [ -z "$new_hostname" ]; then
+    logger -it confd "Empty hostname in $hostname_file"
+    exit 1
+fi
+
+if [ ${#new_hostname} -gt 64 ]; then
+    logger -it confd "Hostname too long (${#new_hostname} > 64) in $hostname_file"
+    exit 1
+fi
+
+# Check if hostname has actually changed
+current_hostname=$(hostname)
+if [ "$new_hostname" = "$current_hostname" ]; then
+    # No change needed, exit silently
+    exit 0
+fi
+
+# Set the hostname
+logger -it confd "Setting hostname to '$new_hostname' from $hostname_file"
+hostname "$new_hostname"
+
+# Update /etc/hostname (for persistence across reboots)
+echo "$new_hostname" > /etc/hostname
+
+# Update /etc/hosts (127.0.1.1 entry for proper name resolution)
+if grep -q "^127\.0\.1\.1" /etc/hosts; then
+    sed -i -E "s/^(127\.0\.1\.1\s+).*/\1$new_hostname/" /etc/hosts
+else
+    # Add entry if it doesn't exist
+    echo "127.0.1.1	$new_hostname" >> /etc/hosts
+fi
+
+# Notify services of hostname change, skip while in bootstrap
+initctl -nbq touch sysklogd
+if ! runlevel >/dev/null 2>&1; then
+    exit 0
+fi
+
+initctl -bq status lldpd && lldpcli configure system hostname "$new_hostname" 2>/dev/null
+initctl -bq status mdns  && avahi-set-host-name "$new_hostname" 2>/dev/null
+initctl -bq touch netbrowse 2>/dev/null
+
+# If called from dhcp script we need to reload to activate new name in syslogd
+# Otherwise we're called from confd, which does the reload when all is done.
+if [ -n "$1" ]; then
+    initctl -b reload
+fi
+
+exit 0

board/common/rootfs/usr/libexec/infix/init.d/05-hostname

@@ -0,0 +1,18 @@
+#!/bin/sh
+# Initialize default hostname for hostname.d pattern
+# This runs very early in boot to set up the default hostname entry
+
+HOSTNAME_D="/etc/hostname.d"
+
+# Ensure directory exists
+mkdir -p "$HOSTNAME_D"
+
+# If no default exists yet, create it from /etc/hostname (from squashfs)
+if [ ! -f "$HOSTNAME_D/10-default" ] && [ -f /etc/hostname ]; then
+    cp /etc/hostname "$HOSTNAME_D/10-default"
+fi
+
+# Apply hostname using the deterministic helper
+if [ -x /usr/libexec/infix/hostname ]; then
+    /usr/libexec/infix/hostname
+fi

board/common/rootfs/usr/share/udhcpc/default.script

@@ -50,24 +50,52 @@ wait_for_ipv6_default_route()
     err "Timed out waiting for IPv6 default route!"
 }
 
+# Check if a DHCP option was requested in the parameter request list
+# Returns: 0 if requested, 1 if not requested or config unavailable
+was_option_requested()
+{
+    local opt_num="$1"
+    local config="/etc/finit.d/available/dhcp-client-${interface}.conf"
+
+    if [ ! -f "$config" ]; then
+	dbg "config file not found: $config"
+	return 1
+    fi
+
+    # Extract udhcpc command line and check for -O <option_num>
+    if grep -q -- "-O ${opt_num}\b" "$config"; then
+	return 0
+    fi
+
+    return 1
+}
+
 # RFC3442: If the DHCP server returns both a Classless
 # Static Routes option and a Router option, the DHCP
 # client MUST ignore the Router option.
 set_dhcp_routes()
 {
     echo "! Generated by udhcpc" > "$NEXT"
     if [ -n "$staticroutes" ]; then
-	# format: dest1/mask gw1 ... destn/mask gwn
-	set -- $staticroutes
-	while [ -n "$1" -a -n "$2" ]; do
-	    dbg "adding route $1 via $2 metric $metric tag 100"
-	    echo "ip route $1 $2 $metric tag 100" >> "$NEXT"
-	    shift 2
-	done
+	if was_option_requested 121; then
+	    # format: dest1/mask gw1 ... destn/mask gwn
+	    set -- $staticroutes
+	    while [ -n "$1" -a -n "$2" ]; do
+		dbg "adding route $1 via $2 metric $metric tag 100"
+		echo "ip route $1 $2 $metric tag 100" >> "$NEXT"
+		shift 2
+	    done
+	else
+	    log "ignoring unrequested staticroutes (option 121)"
+	fi
     elif [ -n "$router" ] ; then
-	for i in $router ; do
-	    echo "ip route 0.0.0.0/0 $i $metric tag 100" >> "$NEXT"
-	done
+	if was_option_requested 3; then
+	    for i in $router ; do
+		echo "ip route 0.0.0.0/0 $i $metric tag 100" >> "$NEXT"
+	    done
+	else
+	    log "ignoring unrequested router (option 3)"
+	fi
     fi
 
     # Reduce changes needed by comparing with previous route(s)
@@ -109,6 +137,11 @@ case "$ACTION" in
 	# drop info from this interface
 	rm -f "$RESOLV_CONF"
 	rm -f "$NTPFILE"
+	if [ -f "/etc/hostname.d/90-dhcp-${interface}" ]; then
+	    log "removing /etc/hostname.d/90-dhcp-${interface}"
+	     rm -f "/etc/hostname.d/90-dhcp-${interface}"
+	     /usr/libexec/infix/hostname dhcp
+	fi
 	if [ -x /usr/sbin/avahi-autoipd ]; then
 	    /usr/sbin/avahi-autoipd -c $interface && /usr/sbin/avahi-autoipd -k $interface
 	fi
@@ -134,41 +167,65 @@ case "$ACTION" in
 
 	set_dhcp_routes
 
-	# set hostname if given
+	# set hostname if given and requested
 	if [ -n "$hostname" ]; then
-	    log "setting new hostname: $hostname"
-	    hostname "$hostname"
-	    sed -i -E "s/^(127\.0\.1\.1\s+).*/\1$hostname/" /etc/hosts
+	    if was_option_requested 12; then
+		log "received DHCP hostname: $hostname"
+		mkdir -p /etc/hostname.d
+		echo "$hostname" > "/etc/hostname.d/90-dhcp-${interface}"
+		/usr/libexec/infix/hostname dhcp
+	    else
+		log "ignoring unrequested hostname (option 12): $hostname"
+	    fi
 	fi
 
 	# drop info from this interface
 	truncate -s 0 "$RESOLV_CONF"
 
 	# prefer rfc3397 domain search list (option 119) if available
+	search_list=""
 	if [ -n "$search" ]; then
-	    search_list=$search
+	    if was_option_requested 119; then
+		search_list=$search
+	    else
+		log "ignoring unrequested search (option 119): $search"
+	    fi
 	elif [ -n "$domain" ]; then
-	    search_list=$domain
+	    if was_option_requested 15; then
+		search_list=$domain
+	    else
+		log "ignoring unrequested domain (option 15): $domain"
+	    fi
 	fi
 
 	if [ -n "$search_list" ]; then
 	    dbg "adding search $search_list"
 	    echo "search $search_list # $interface" >> $RESOLV_CONF
 	fi
 
-	for i in $dns ; do
-	    dbg "adding dns $i"
-	    echo "nameserver $i # $interface" >> $RESOLV_CONF
-	    resolvconf -u
-	done
+	if [ -n "$dns" ]; then
+	    if was_option_requested 6; then
+		for i in $dns ; do
+		    dbg "adding dns $i"
+		    echo "nameserver $i # $interface" >> $RESOLV_CONF
+		    resolvconf -u
+		done
+	    else
+		log "ignoring unrequested dns (option 6): $dns"
+	    fi
+	fi
 
 	if [ -n "$ntpsrv" ]; then
-	    truncate -s 0 "$NTPFILE"
-	    for srv in $ntpsrv; do
-		dbg "got NTP server $srv"
-		echo "server $srv iburst" >> "$NTPFILE"
-	    done
-	    chronyc reload sources >/dev/null
+	    if was_option_requested 42; then
+		truncate -s 0 "$NTPFILE"
+		for srv in $ntpsrv; do
+		    dbg "got NTP server $srv"
+		    echo "server $srv iburst" >> "$NTPFILE"
+		done
+		chronyc reload sources >/dev/null
+	    else
+		log "ignoring unrequested ntpsrv (option 42): $ntpsrv"
+	    fi
 	fi
 esac
 

doc/ChangeLog.md

@@ -48,11 +48,13 @@ All notable changes to the project are documented in this file.
 ### Fixes
 
 - Fix #855: User admin sometimes fails to be added to `wheel` group
+- Fix #1112: setting hostname via DHCP client sometimes gets overridden by the
+  configured system hostname
 - Fix #1247: Prevent invalid configuration of OSPF backbone area (0.0.0.0) as
   stub or NSSA. The backbone must always be a normal area per RFC 2328. Any
   existing invalid configurations are automatically corrected during upgrade
-- Fix serious regression in boot time, introduced in v25.10, delays the
-  boot step "Mounting filesystems ..." with up to 30 seconds!
+- Fix #1255: serious regression in boot time, introduced in v25.10, delays the
+  boot step "Mounting filesystems ...", from 30 seconds up to five minutes!
 - Fix broken intra-document links in container and tunnel documentation
 
 [lastest-boot]: https://github.com/kernelkit/infix/releases/latest-boot