source: rtems-libbsd/dhcpcd/dhcpcd-run-hooks.in @ d61f731

#!/bin/sh
# dhcpcd client configuration script 

# Handy variables and functions for our hooks to use
case "$reason" in
        ROUTERADVERT)
                ifsuffix=":ra";;
        INFORM6|BOUND6|RENEW6|REBIND6|REBOOT6|EXPIRE6|RELEASE6|STOP6)
                ifsuffix=":dhcp6";;
        *)
                ifsuffix=;;
esac
ifname="$interface$ifsuffix"

from=from
signature_base="# Generated by dhcpcd"
signature="$signature_base $from $ifname"
signature_base_end="# End of dhcpcd"
signature_end="$signature_base_end $from $ifname"
state_dir=@RUNDIR@/dhcpcd
_detected_init=false

: ${if_up:=false}
: ${if_down:=false}

# Ensure that all arguments are unique
uniqify()
{
        local result= i=
        for i do
                case " $result " in
                        *" $i "*);;
                        *) result="$result $i";;
                esac
        done
        echo "${result# *}"
}

# List interface config files in a directory.
# If dhcpcd is running as a single instance then it will have a list of
# interfaces in the preferred order.
# Otherwise we just use what we have.
list_interfaces()
{
        local i= x= ifaces=
        for i in $interface_order; do
                [ -e "$1/$i" ] && ifaces="$ifaces${ifaces:+ }$i"
        done
        for x in "$1"/*; do
                [ -e "$x" ] || continue
                for i in $interface_order; do
                        if [ $i = "${x##*/}" ]; then
                                unset x
                                break
                        fi
                done
                [ -n "$x" ] && ifaces="$ifaces${ifaces:+ }${x##*/}"
        done
        echo "$ifaces"
}

# Trim function
trim()
{
        local var="$*"

        var=${var#"${var%%[![:space:]]*}"}
        var=${var%"${var##*[![:space:]]}"}
        if [ -z "$var" ]; then
                # So it seems our shell doesn't support wctype(3) patterns
                # Fall back to sed
                var=$(echo "$*" | sed -e 's/^[[:space:]]*//;s/[[:space:]]*$//')
        fi
        printf %s "$var"
}

# We normally use sed to extract values using a key from a list of files
# but sed may not always be available at the time.
key_get_value()
{
        local key="$1" value= x= line=

        shift
        if type sed >/dev/null 2>&1; then
                sed -n "s/^$key//p" $@
        else
                for x do
                        while read line; do
                                case "$line" in
                                "$key"*) echo "${line##$key}";;
                                esac
                        done < "$x"
                done
        fi
}

# We normally use sed to remove markers from a configuration file
# but sed may not always be available at the time.
remove_markers()
{
        local m1="$1" m2="$2" x= line= in_marker=0

        shift; shift
        if type sed >/dev/null 2>&1; then
                sed "/^$m1/,/^$m2/d" $@
        else
                for x do
                        while read line; do
                                case "$line" in
                                "$m1"*) in_marker=1;;
                                "$m2"*) in_marker=0;;
                                *) [ $in_marker = 0 ] && echo "$line";;
                                esac
                        done < "$x"
                done
        fi
}

# Compare two files.
# If different, replace first with second otherwise remove second.
change_file()
{
        if [ -e "$1" ]; then
                if type cmp >/dev/null 2>&1; then
                        cmp -s "$1" "$2"
                elif type diff >/dev/null 2>&1; then
                        diff -q "$1" "$2" >/dev/null
                else
                        # Hopefully we're only working on small text files ...
                        [ "$(cat "$1")" = "$(cat "$2")" ]
                fi
                if [ $? -eq 0 ]; then
                        rm -f "$2"
                        return 1
                fi
        fi
        cat "$2" > "$1"
        rm -f "$2"
        return 0
}

# Save a config file
save_conf()
{
        if [ -f "$1" ]; then
                rm -f "$1-pre.$interface"
                cat "$1" > "$1-pre.$interface"
        fi
}

# Restore a config file
restore_conf()
{
        [ -f "$1-pre.$interface" ] || return 1
        cat "$1-pre.$interface" > "$1"
        rm -f "$1-pre.$interface"
}

# Write a syslog entry
syslog()
{
        local lvl="$1"

        [ -n "$lvl" ] && shift
        if [ -n "$*" ]; then
                if type logger >/dev/null 2>&1; then
                        logger -t dhcpcd -p daemon."$lvl" -is "$interface: $*"
                fi
        fi
}

# Check for a valid domain name as per RFC1123 with the exception of
# allowing - and _ as they seem to be widely used.
valid_domainname()
{
        local name="$1" label

        [ -z "$name" -o ${#name} -gt 255 ] && return 1
        
        while [ -n "$name" ]; do
                label="${name%%.*}"
                [ -z "$label" -o ${#label} -gt 63 ] && return 1
                case "$label" in
                -*|_*|*-|*_)            return 1;;
                *[![:alnum:]-_]*)       return 1;;
                esac
                [ "$name" = "${name#*.}" ] && break
                name="${name#*.}"
        done
        return 0        
}

valid_domainname_list()
{
        local name

        for name do
                valid_domainname "$name" || return $?
        done
        return 0
}

# Check for a valid path
valid_path()
{
        case "$@" in
        *[![:alnum:]#%+-_:\.,@~\\/\[\]=\ ]*) return 1;;
        esac
        return 0
}

# With the advent of alternative init systems, it's possible to have
# more than one installed. So we need to try and guess what one we're
# using unless overriden by configure.
detect_init()
{
        _service_exists="@SERVICEEXISTS@"
        _service_cmd="@SERVICECMD@"
        _service_status="@SERVICESTATUS@"

        [ -n "$_service_cmd" ] && return 0

        if ${_detected_init}; then
                [ -n "$_service_cmd" ]
                return $?
        fi

        # Detect the running init system.
        # As systemd and OpenRC can be installed on top of legacy init
        # systems we try to detect them first.
        _service_status=
        if [ -x /bin/systemctl -a -S /run/systemd/private ]; then
                _service_exists="/bin/systemctl --quiet is-enabled \$1.service"
                _service_status="/bin/systemctl --quiet is-active \$1.service"
                _service_cmd="/bin/systemctl \$2 \$1.service"
        elif [ -x /usr/bin/systemctl -a -S /run/systemd/private ]; then
                _service_exists="/usr/bin/systemctl --quiet is-enabled \$1.service"
                _service_status="/usr/bin/systemctl --quiet is-active \$1.service"
                _service_cmd="/usr/bin/systemctl \$2 \$1.service"
        elif [ -x /sbin/rc-service -a \
            -s /libexec/rc/init.d/softlevel -o -s /run/openrc/softlevel ]
        then
                _service_exists="/sbin/rc-service -e \$1"
                _service_cmd="/sbin/rc-service \$1 -- -D \$2"
        elif [ -x /usr/sbin/invoke-rc.d ]; then
                _service_exists="/usr/sbin/invoke-rc.d --query --quiet \$1 start >/dev/null 2>&1 || [ \$? = 104 ]"
                _service_cmd="/usr/sbin/invoke-rc.d \$1 \$2"
        elif [ -x /sbin/service ]; then
                _service_exists="/sbin/service \$1 >/dev/null 2>&1"
                _service_cmd="/sbin/service \$1 \$2"
        elif [ -e /etc/slackware-version -a -d /etc/rc.d ]; then
                _service_exists="[ -x /etc/rc.d/rc.\$1 ]"
                _service_cmd="/etc/rc.d/rc.\$1 \$2"
                _service_status="/etc/rc.d/rc.\$1 status 1>/dev/null 2>&1"
        else
                for x in /etc/init.d/rc.d /etc/rc.d /etc/init.d; do
                        if [ -d $x ]; then
                                _service_exists="[ -x $x/\$1 ]"
                                _service_cmd="$x/\$1 \$2"
                                break
                        fi
                done
                if [ -e /etc/arch-release ]; then
                        _service_status="[ -e /var/run/daemons/\$1 ]"
                fi
        fi

        _detected_init=true
        if [ -z "$_service_cmd" ]; then
                syslog err "could not detect a useable init system"
                return 1
        fi
        return 0
}

# Check a system service exists 
service_exists()
{

        if [ -z "$_service_exists" ]; then
                detect_init || return 1
        fi
        eval $_service_exists
}

# Send a command to a system service
service_cmd()
{

        if [ -z "$_service_cmd" ]; then
                detect_init || return 1
        fi
        eval $_service_cmd
}

# Send a command to a system service if it is running
service_status()
{

        if [ -z "$_service_cmd" ]; then
                detect_init || return 1
        fi
        if [ -n "$_service_status" ]; then
                eval $_service_status
        else
                service_command $1 status >/dev/null 2>&1
        fi
}

# Handy macros for our hooks
service_command()
{

        service_exists $1 && service_cmd $1 $2
}
service_condcommand()
{

        service_exists $1 && service_status $1 && service_cmd $1 $2
}

# We source each script into this one so that scripts run earlier can
# remove variables from the environment so later scripts don't see them.
# Thus, the user can create their dhcpcd.enter/exit-hook script to configure
# /etc/resolv.conf how they want and stop the system scripts ever updating it.
for hook in \
        @SYSCONFDIR@/dhcpcd.enter-hook \
        @HOOKDIR@/* \
        @SYSCONFDIR@/dhcpcd.exit-hook
do
        for skip in $skip_hooks; do
                case "$hook" in
                        */*~)                           continue 2;;
                        */"$skip")                      continue 2;;
                        */[0-9][0-9]"-$skip")           continue 2;;
                        */[0-9][0-9]"-$skip.sh")        continue 2;;
                esac
        done
        if [ -f "$hook" ]; then
                . "$hook"
        fi
done