lib/common/addipopt.c

/*
 * Copyright (C) 1993-2001 by Darren Reed.
 *
 * See the IPFILTER.LICENCE file for details on licencing.
 *
 * $Id: addipopt.c,v 1.7 2002/01/28 06:50:45 darrenr Exp $
 */

#include "ipf.h"


int addipopt(op, io, len, class)
char *op;
struct ipopt_names *io;
int len;
char *class;
{
    int olen = len;
    struct in_addr ipadr;
    u_short val;
    u_char lvl;
    char *s;

    if ((len + io->on_siz) > 48) {
        fprintf(stderr, "options too long\n");
        return 0;
    }
    len += io->on_siz;
    *op++ = io->on_value;
    if (io->on_siz > 1) {
        s = op;
        *op++ = io->on_siz;
        *op++ = IPOPT_MINOFF;

        if (class) {
            switch (io->on_value)
            {
            case IPOPT_SECURITY :
                lvl = seclevel(class);
                *(op - 1) = lvl;
                break;
            case IPOPT_LSRR :
            case IPOPT_SSRR :
                ipadr.s_addr = inet_addr(class);
                s[IPOPT_OLEN] = IPOPT_MINOFF - 1 + 4;
                bcopy((char *)&ipadr, op, sizeof(ipadr));
                break;
            case IPOPT_SATID :
                val = atoi(class);
                bcopy((char *)&val, op, 2);
                break;
            }
        }

        op += io->on_siz - 3;
        if (len & 3) {
            *op++ = IPOPT_NOP;
            len++;
        }
    }
    if (opts & OPT_DEBUG)
        fprintf(stderr, "bo: %s %d %#x: %d\n",
            io->on_name, io->on_value, io->on_bit, len);
    return len - olen;
}