freebsd-dev/libexec/rc/rc.d/netwait

#!/bin/sh

# $FreeBSD$
#
# PROVIDE: netwait
# REQUIRE: devd ipfw pf routing
# KEYWORD: nojail
#
# The netwait script helps handle two situations:
#  - Systems with USB or other late-attaching network hardware which
#    is initialized by devd events.  The script waits for all the
#    interfaces named in the netwait_if list to appear.
#  - Systems with statically-configured IP addresses in rc.conf(5).
#    The IP addresses in the netwait_ip list are pinged.  The script
#    waits for any single IP in the list to respond to the ping.  If your
#    system uses DHCP, you should probably use synchronous_dhclient="YES"
#    in your /etc/rc.conf instead of netwait_ip.
# Either or both of the wait lists can be used (at least one must be
# non-empty if netwait is enabled).

. /etc/rc.subr

name="netwait"
desc="Wait for network devices or the network being up"
rcvar="netwait_enable"

start_cmd="${name}_start"
stop_cmd=":"

netwait_start()
{
	local ip rc count output link wait_if got_if any_error

	if [ -z "${netwait_if}" ] && [ -z "${netwait_ip}" ]; then
		err 1 "No interface or IP addresses listed, nothing to wait for"
	fi

	if [ ${netwait_timeout} -lt 1 ]; then
		err 1 "netwait_timeout must be >= 1"
	fi

	if [ -n "${netwait_if}" ]; then
		any_error=0
		for wait_if in ${netwait_if}; do
			echo -n "Waiting for ${wait_if}"
			link=""
			got_if=0
			count=1
			# Handle SIGINT (Ctrl-C); force abort of while() loop
			trap break SIGINT
			while [ ${count} -le ${netwait_if_timeout} ]; do
				if output=`/sbin/ifconfig ${wait_if} 2>/dev/null`; then
					if [ ${got_if} -eq 0 ]; then
						echo -n ", interface present"
						got_if=1
					fi
					link=`expr "${output}" : '.*[[:blank:]]status: \(no carrier\)'`
					if [ -z "${link}" ]; then
						echo ', got link.'
						break
					fi
				fi
				sleep 1
				count=$((count+1))
			done
			# Restore default SIGINT handler
			trap - SIGINT
			if [ ${got_if} -eq 0 ]; then
				echo ", wait failed: interface never appeared."
				any_error=1
			elif [ -n "${link}" ]; then
				echo ", wait failed: interface still has no link."
				any_error=1
			fi
		done
		if [ ${any_error} -eq 1 ]; then
		    warn "Continuing with startup, but be aware you may not have "
		    warn "a fully functional networking layer at this point."
		fi
	fi
	
	if [ -n "${netwait_ip}" ]; then
		# Handle SIGINT (Ctrl-C); force abort of for() loop
		trap break SIGINT

		for ip in ${netwait_ip}; do
			echo -n "Waiting for ${ip} to respond to ICMP ping"

			count=1
			while [ ${count} -le ${netwait_timeout} ]; do
				/sbin/ping -t 1 -c 1 -o ${ip} >/dev/null 2>&1
				rc=$?

				if [ $rc -eq 0 ]; then
					# Restore default SIGINT handler
					trap - SIGINT

					echo ', got response.'
					return
				fi
				count=$((count+1))
			done
			echo ', failed: No response from host.'
		done

		# Restore default SIGINT handler
		trap - SIGINT

		warn "Exhausted IP list.  Continuing with startup, but be aware you may"
		warn "not have a fully functional networking layer at this point."
	fi

}

load_rc_config $name
run_rc_command "$1"