[strongSwan] StrongSwan 5.1.3 on OpenWRT depends on modprobe?

[Guangyao Zhan]

I installed StrongSwan 5.1.3 on OpenWRT 12.09 stable release, but it
depends on modprobe which isn't available on OpenWRT (only insmod is
available). How should I fix this?

# opkg install strongswan-full
# ipsec start
no files found matching '/etc/strongswan.d/charon/*.conf', ignored
no files found matching '/etc/strongswan.d/*.conf', ignored
Starting strongSwan 5.1.3 IPsec [starter]...
/bin/sh: modprobe: not found
/bin/sh: modprobe: not found
/bin/sh: modprobe: not found
/bin/sh: modprobe: not found
/bin/sh: modprobe: not found