Current File : //snap/core/17200/lib/resolvconf/net-interface-handler
#!/bin/sh
# copy dns settings from a dhcp in the initramfs into resolvconf.
# This is invoked from udev via 70-resolvconf-initramfs-copy.rules
#
DEBUG=0
OPENISCSI_MARKER=/run/initramfs/open-iscsi.interface
PROG="rconf-initrd" # PROG, per resolvconf(8) IFACE.PROG
CR="
"
error() {
echo "$0${INTERFACE:+[$INTERFACE]}:" "$@" 1>&2
}
debug() {
[ "${DEBUG:-0}" != "0" ] || return 0
error "$@" 1>&2;
}
enabled_on_kernel_cmdline() {
# this can be enabled on the kernel command line if
# it has either cloud-config-url= (maas will have this)
# or it explicitly has 'rc-initrd-dns' (mostly testing)
local cmdline=""
if [ ! -e /proc/cmdline ]; then
debug "/proc/cmdline does not exist."
return 1
fi
read cmdline < /proc/cmdline
case " $cmdline " in
*cloud-config-url=*|*\ rc-initrd-dns\ *) :;;
*\ root=http*) :;; # LP: #1735225
*) debug "not enabled in kernel cmdline."; return 1;;
esac
# if the command line matched, we may be in a container
# where a shared cmdline with the host.
if command -v systemd-detect-virt >/dev/null 2>&1; then
local out=""
out=$(systemd-detect-virt --container)
case "$out" in
none) :;;
*) debug "inside a container, ignoring cmdline."; return 1;;
esac
fi
return 0
}
should_be_enabled() {
if [ -f "${OPENISCSI_MARKER}" ]; then
debug "open-iscsi in control per ${OPENISCSI_MARKER}"
return 1
fi
if ! enabled_on_kernel_cmdline; then
return 1
fi
return 0
}
assert_environment() {
if [ -z "$INTERFACE" ]; then
error "'INTERFACE' not set in environment."
return 1
fi
return 0
}
netinfo_to_resolv_conf() {
# netinfo_to_resolv_conf(output, files)
# write resolv_conf from /run/net-<device> style files.
# borrowed with slight modification from initramfs-tools/scripts/functions
local output="$1" search="" ns="" f="" n=""
shift
for f in "$@"; do
[ -f "$f" ] || continue
unset IPV4DNS0 IPV4DNS1 IPV6DNS0 IPV6DNS1
unset DOMAINSEARCH IPV6DOMAINSEARCH
. "$f" || { error "failed '. \"$f\"'" 1>&2; return 1; }
for n in "${IPV4DNS0}" "${IPV4DNS1}" \
"${IPV6DNS0}" "${IPV6DNS1}"; do
[ -n "$n" -a "$n" != "0.0.0.0" ] || continue
# skip if 'n' already in list.
case " ${ns} " in
*\ $n\ *) continue;;
esac
ns="${ns} ${n}"
done
for n in "${DOMAINSEARCH}" "${IPV6DOMAINSEARCH}"; do
[ -n "$n" ] || continue
# skip if already in search.
case " ${search}" in
*\ $n\ *) continue;;
esac
search="$search $n"
done
search=${search# }
ns=${ns# }
done
local rconf=""
for n in ${ns}; do
rconf="${rconf}nameserver $n${CR}"
done
if [ -n "${search}" ]; then
rconf="${rconf}search ${search}${CR}"
fi
if [ -z "$rconf" ]; then
debug "no search or nameservers found in $*"
fi
if [ "$output" = "-" ]; then
echo -n "$rconf"
else
echo -n "$rconf" > "$output"
fi
}
start() {
# if open-iscsi is involved we assume it is in charge of this work.
assert_environment || return
should_be_enabled || return 0
local iface="$INTERFACE" i="" rconf=""
set --
for i in "/run/net-$iface.conf" "/run/net6-$iface.conf"; do
[ -f "$i" ] || continue
set -- "$@" "$i"
done
if [ $# -eq 0 ]; then
debug "no /run/net*-$iface.conf files found."
return 0
fi
rconf=$(netinfo_to_resolv_conf - "$@")
if [ -z "$rconf" ]; then
debug "no resolv.conf related settings in $*"
return 0
fi
# create the dir in case resolvconf did not start yet
mkdir -p /run/resolvconf/interface
debug echo "\"$rconf\"" "|" "resolvconf -a $iface.$PROG"
echo "$rconf" | resolvconf -a "$iface.$PROG"
}
stop() {
assert_environment || return
should_be_enabled || return 0
local iface="$INTERFACE"
debug resolvconf -d "$iface.$PROG"
resolvconf -d "$iface.$PROG"
}
case "$1" in
start) start ;;
stop) stop ;;
_test) :;;
*) echo "ERROR: must be called with 'start' or 'stop'" >&2; exit 1 ;;
esac
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