[root@vpn openswan-2.4.9]# make nattpatch | (cd /usr/src/kernels/2.6.18-8.1.15.el5-i686 && patch -p1 && make bzImage)
patching file include/net/xfrmudp.h
patching file net/ipv4/Kconfig
Hunk #1 succeeded at 351 with fuzz 1.
can't find file to patch at input line 33
Perhaps you used the wrong -p or --strip option?
The text leading up to this was:
--------------------------
|--- plain26/net/ipv4/udp.c.orig        2006-01-02 22:21:10.000000000 -0500
|+++ plain26/net/ipv4/udp.c     2006-01-12 20:18:57.000000000 -0500
--------------------------
File to patch: