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infix/board/common/rootfs/usr/share/udhcpc/default.script
T
Joachim WibergandMattias Walström 2fa5dcfea0 board/common: major refactor of udhcpc script
- New log() function replaces stdout logging
 - New set_dhcp_routes() and clr_dhcp_routes() functions
   - Set all option 121 routes with same metric
   - Set all option 3 routers with increasing metric (this is what the
     reference udhcpc scripts do, and RFC says the routers should be
     listed in order of preference ...)
   - Clearing routes must, like IP addresses, be done both by interface
     and protocol.  This refactor makes sure to delete any DHCP routes
     set on the given interface (in case options change)
 - Use resolvconf per-interface search+nameserver
 - Cache IP lease so we can ask for it back later
 - On deconfig|leasefail|nak, make sure to clean up anything that might
   be lingering from this interface.  E.g., we can get leasefail when a
   server denies our request to prolong a lease.
 - On renew|bound, refresh routes, and set search+dns + NTP servers

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
2023-12-14 16:40:41 +01:00

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#!/bin/sh
# This script expect a system with resolvconf (openresolv) and iproute2
[ -z "$1" ] && echo "Error: should be called from udhcpc" && exit 1
ACTION="$1"
IP_CACHE="/var/lib/misc/${interface}.cache"
RESOLV_CONF="/run/resolvconf/interfaces/${interface}.conf"
NTPFILE="/run/chrony/dhcp-sources.d/${interface}.sources"
[ -n "$broadcast" ] && BROADCAST="broadcast $broadcast"
[ -n "$subnet" ] && NETMASK="$subnet"
[ -n "$metric" ] || metric=100
# Handle stateful DHCPv6 like DHCPv4
[ -n "$ipv6" ] && ip="$ipv6/128"
if [ -z "${IF_WAIT_DELAY}" ]; then
IF_WAIT_DELAY=10
fi
log()
{
logger -I $$ -t udhcpc -p user.notice "$*"
}
wwait_for_ipv6_default_route()
{
log "waiting for IPv6 default route to be installed."
while [ $IF_WAIT_DELAY -gt 0 ]; do
if ip -6 route list proto dhcp dev $interface | grep -q default; then
return
fi
sleep 1
printf "."
: $((IF_WAIT_DELAY -= 1))
done
log "Timed out witing for IPv6 default route!"
}
# RFC3442: If the DHCP server returns both a Classless
# Static Routes option and a Router option, the DHCP
# client MUST ignore the Router option.
set_dhcp_routes()
{
if [ -n "$staticroutes" ]; then
# format: dest1/mask gw1 ... destn/mask gwn
set -- $staticroutes
while [ -n "$1" -a -n "$2" ]; do
log "adding route $1 via $2 dev $interface proto dhcp"
ip route add "$1" via "$2" dev $interface metric $metric proto dhcp
shift 2
done
elif [ -n "$router" ] ; then
for i in $router ; do
ip route add default via $i dev $interface metric $((metric++)) proto dhcp
done
fi
}
clr_dhcp_routes()
{
log "deleting DHCP routes from $interface"
ip route show proto dhcp dev $interface | while read rt via nh dev dev; do
log "removing $rt nh $nh on $dev"
ip route del $rt via $nh dev $dev proto dhcp
done
}
clr_dhcp_addresses()
{
addrs=$(ip -j addr show dev $interface \
| jq -c '.[0].addr_info[] | select(.family == "inet") | select(.protocol == "dhcp")')
for addr in $addrs; do
ip="$(echo "$addr" | jq -r '."local"')"
prefix="$(echo "$addr" | jq -r '."prefixlen"')"
log "removing $ip/$prefix from $interface"
ip addr del "$ip/$prefix" dev "$interface"
done
}
log "action $ACTION"
case "$ACTION" in
deconfig)
clr_dhcp_addresses
clr_dhcp_routes
/bin/ip link set dev $interface up
# drop info from this interface
rm -f "$RESOLV_CONF"
rm -f "$NTPFILE"
if [ -x /usr/sbin/avahi-autoipd ]; then
/usr/sbin/avahi-autoipd -c $interface && /usr/sbin/avahi-autoipd -k $interface
fi
;;
leasefail|nak)
if [ -x /usr/sbin/avahi-autoipd ]; then
/usr/sbin/avahi-autoipd -c $interface || /usr/sbin/avahi-autoipd -wD $interface --no-chroot
fi
;;
renew|bound)
if [ -x /usr/sbin/avahi-autoipd ]; then
/usr/sbin/avahi-autoipd -c $interface && /usr/sbin/avahi-autoipd -k $interface
fi
if /bin/ip addr add dev $interface $ip/$NETMASK $BROADCAST proto 5; then
echo "$ip" > "$IP_CACHE"
fi
if [ -n "$ipv6" ] ; then
wait_for_ipv6_default_route
fi
clr_dhcp_routes
set_dhcp_routes
# drop info from this interface
truncate -s 0 "$RESOLV_CONF"
# prefer rfc3397 domain search list (option 119) if available
if [ -n "$search" ]; then
search_list=$search
elif [ -n "$domain" ]; then
search_list=$domain
fi
if [ -n "$search_list" ]; then
log "adding search $search_list"
echo "search $search_list # $interface" >> $RESOLV_CONF
fi
for i in $dns ; do
log "adding dns $i"
echo "nameserver $i # $interface" >> $RESOLV_CONF
resolvconf -u
done
if [ -n "$ntpsrv" ]; then
truncate -s 0 "$NTPFILE"
for srv in $ntpsrv; do
log "got NTP server $srv"
echo "server $srv iburst" >> "$NTPFILE"
done
chronyc reload sources >/dev/null
fi
esac
HOOK_DIR="$0.d"
for hook in "${HOOK_DIR}/"*; do
[ -f "${hook}" -a -x "${hook}" ] || continue
"${hook}" "$ACTION"
done
exit 0