extensions/libxt_CONNMARK.c

/* Shared library add-on to iptables to add CONNMARK target support.
 *
 * (C) 2002,2004 MARA Systems AB <http://www.marasystems.com>
 * by Henrik Nordstrom <hno@marasystems.com>
 *
 * Version 1.1
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>

#include <xtables.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_CONNMARK.h>

#if 0
struct markinfo {
	struct xt_entry_target t;
	struct ipt_connmark_target_info mark;
};
#endif

/* Function which prints out usage message. */
static void CONNMARK_help(void)
{
	printf(
"CONNMARK target v%s options:\n"
"  --set-mark value[/mask]       Set conntrack mark value\n"
"  --save-mark [--mask mask]     Save the packet nfmark in the connection\n"
"  --restore-mark [--mask mask]  Restore saved nfmark value\n"
"\n",
IPTABLES_VERSION);
}

static const struct option CONNMARK_opts[] = {
	{ "set-mark", 1, NULL, '1' },
	{ "save-mark", 0, NULL, '2' },
	{ "restore-mark", 0, NULL, '3' },
	{ "mask", 1, NULL, '4' },
	{ }
};

/* Function which parses command options; returns true if it
   ate an option */
static int
CONNMARK_parse(int c, char **argv, int invert, unsigned int *flags,
               const void *entry, struct xt_entry_target **target)
{
	struct xt_connmark_target_info *markinfo
		= (struct xt_connmark_target_info *)(*target)->data;

	markinfo->mask = 0xffffffffUL;

	switch (c) {
		char *end;
	case '1':
		markinfo->mode = XT_CONNMARK_SET;

		markinfo->mark = strtoul(optarg, &end, 0);
		if (*end == '/' && end[1] != '\0')
		    markinfo->mask = strtoul(end+1, &end, 0);

		if (*end != '\0' || end == optarg)
			exit_error(PARAMETER_PROBLEM, "Bad MARK value `%s'", optarg);
		if (*flags)
			exit_error(PARAMETER_PROBLEM,
			           "CONNMARK target: Can't specify --set-mark twice");
		*flags = 1;
		break;
	case '2':
		markinfo->mode = XT_CONNMARK_SAVE;
		if (*flags)
			exit_error(PARAMETER_PROBLEM,
			           "CONNMARK target: Can't specify --save-mark twice");
		*flags = 1;
		break;
	case '3':
		markinfo->mode = XT_CONNMARK_RESTORE;
		if (*flags)
			exit_error(PARAMETER_PROBLEM,
			           "CONNMARK target: Can't specify --restore-mark twice");
		*flags = 1;
		break;
	case '4':
		if (!*flags)
			exit_error(PARAMETER_PROBLEM,
			           "CONNMARK target: Can't specify --mask without a operation");
		markinfo->mask = strtoul(optarg, &end, 0);

		if (*end != '\0' || end == optarg)
			exit_error(PARAMETER_PROBLEM, "Bad MASK value `%s'", optarg);
		break;
	default:
		return 0;
	}

	return 1;
}

static void CONNMARK_check(unsigned int flags)
{
	if (!flags)
		exit_error(PARAMETER_PROBLEM,
		           "CONNMARK target: No operation specified");
}

static void
print_mark(unsigned long mark)
{
	printf("0x%lx", mark);
}

static void
print_mask(const char *text, unsigned long mask)
{
	if (mask != 0xffffffffUL)
		printf("%s0x%lx", text, mask);
}


/* Prints out the target info. */
static void CONNMARK_print(const void *ip,
                           const struct xt_entry_target *target, int numeric)
{
	const struct xt_connmark_target_info *markinfo =
		(const struct xt_connmark_target_info *)target->data;
	switch (markinfo->mode) {
	case XT_CONNMARK_SET:
	    printf("CONNMARK set ");
	    print_mark(markinfo->mark);
	    print_mask("/", markinfo->mask);
	    printf(" ");
	    break;
	case XT_CONNMARK_SAVE:
	    printf("CONNMARK save ");
	    print_mask("mask ", markinfo->mask);
	    printf(" ");
	    break;
	case XT_CONNMARK_RESTORE:
	    printf("CONNMARK restore ");
	    print_mask("mask ", markinfo->mask);
	    break;
	default:
	    printf("ERROR: UNKNOWN CONNMARK MODE ");
	    break;
	}
}

/* Saves the target into in parsable form to stdout. */
static void CONNMARK_save(const void *ip, const struct xt_entry_target *target)
{
	const struct xt_connmark_target_info *markinfo =
		(const struct xt_connmark_target_info *)target->data;

	switch (markinfo->mode) {
	case XT_CONNMARK_SET:
	    printf("--set-mark ");
	    print_mark(markinfo->mark);
	    print_mask("/", markinfo->mask);
	    printf(" ");
	    break;
	case XT_CONNMARK_SAVE:
	    printf("--save-mark ");
	    print_mask("--mask ", markinfo->mask);
	    break;
	case XT_CONNMARK_RESTORE:
	    printf("--restore-mark ");
	    print_mask("--mask ", markinfo->mask);
	    break;
	default:
	    printf("ERROR: UNKNOWN CONNMARK MODE ");
	    break;
	}
}

static struct xtables_target connmark_target = {
	.family		= AF_INET,
	.name		= "CONNMARK",
	.version	= IPTABLES_VERSION,
	.size		= XT_ALIGN(sizeof(struct xt_connmark_target_info)),
	.userspacesize	= XT_ALIGN(sizeof(struct xt_connmark_target_info)),
	.help		= CONNMARK_help,
	.parse		= CONNMARK_parse,
	.final_check	= CONNMARK_check,
	.print		= CONNMARK_print,
	.save		= CONNMARK_save,
	.extra_opts	= CONNMARK_opts,
};

static struct xtables_target connmark_target6 = {
	.family		= AF_INET6,
	.name		= "CONNMARK",
	.version	= IPTABLES_VERSION,
	.size		= XT_ALIGN(sizeof(struct xt_connmark_target_info)),
	.userspacesize	= XT_ALIGN(sizeof(struct xt_connmark_target_info)),
	.help		= CONNMARK_help,
	.parse		= CONNMARK_parse,
	.final_check	= CONNMARK_check,
	.print		= CONNMARK_print,
	.save		= CONNMARK_save,
	.extra_opts	= CONNMARK_opts,
};

void _init(void)
{
	xtables_register_target(&connmark_target);
	xtables_register_target(&connmark_target6);
}