pptp uses very few linux-specific features, and should be easily portable to most Unix systems. Two things to watch: 1) The code in pty.[ch] to find a free pty/tty pair. This was conceptually borrowed from the xterm sources, which need to do more or less the same thing. *But* the xterm sources had a heck of a lot more system-specific #defines to cover all the eccentric unix variants out there. If you are porting this code to a non-unix system, I would recommend downloading the xterm sources to find out how pty.[ch] should look for your system. Xterm is in the standard X distribution, or you can download SRRMs from ftp.redhat.com. Configure the xterm sources for your machine, and then preprocess main.c with these configuration options. E.g. I did: [cananian@cananian xterm-sb_right-ansi-3d]# make main.o rm -f main.o gcc -c -O2 -fno-strength-reduce -m486 -I/usr/X11R6/include -Dlinux -D__i386__ -D_POSIX_SOURCE -D_BSD_SOURCE -D_SVID_SOURCE -DX_LOCALE -DFUNCPROTO=15 -DNARROWPROTO -DUTMP -DUSE_TTY_GROUP -DOSMAJORVERSION=2 -DOSMINORVERSION=0 main.c So the appropriate preprocessing command would be: [cananian@cananian xterm-sb_right-ansi-3d]# gcc -E -O2 -fno-strength-reduce -m486 -I/usr/X11R6/include -Dlinux -D__i386__ -D_POSIX_SOURCE -D_BSD_SOURCE -D_SVID_SOURCE -DX_LOCALE -DFUNCPROTO=15 -DNARROWPROTO -DUTMP -DUSE_TTY_GROUP -DOSMAJORVERSION=2 -DOSMINORVERSION=0 main.c > main.CPP Grok through the sources to figure out how the ptys are allocated on your machine. I suspect many people will want to look carefully at the function pty_search(), but there are architectures that have other, built-in, functions for doing the same thing. Add the code to pty.[ch] with the proper #ifdefs, mail a patch back to me at <cananian@alumni.princeton.edu> and you're good to go! 2) The pptp_gre_copy function opens an IP protocol socket with: s = socket(AF_INET, SOCK_RAW, PPTP_PROTO); where PPTP_PROTO is #define'd in the code to be 47. I *think* that this should work across Unix variants, but if your system has a different method for opening a non-TCP, raw-IP-protocol-47 socket, then you'll have to make some changes here, and perhaps in decaps_gre and encaps_gre as well. OK. Those are the only two potential non-portabilities I can think of. I should really be using automake/autoconf, of course, as well. --Scott 15Dec1997 -------------------------------------------------------------------- C. Scott Ananian <cananian@alumni.princeton.edu>