/* Shared library add-on to iptables to add devgroup matching support.

 *

 * Copyright (c) 2011 Patrick McHardy <kaber@trash.net>

 */

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <errno.h>

#include <xtables.h>

#include <linux/netfilter/xt_devgroup.h>

static void devgroup_help(void)

{

	printf(

"devgroup match options:\n"

"[!] --src-group value[/mask]	Match device group of incoming device\n"

"[!] --dst-group value[/mask]	Match device group of outgoing device\n"

		);

}

enum {

	O_SRC_GROUP = 0,

	O_DST_GROUP,

};

static const struct xt_option_entry devgroup_opts[] = {

	{.name = "src-group", .id = O_SRC_GROUP, .type = XTTYPE_STRING,

	 .flags = XTOPT_INVERT},

	{.name = "dst-group", .id = O_DST_GROUP, .type = XTTYPE_STRING,

	 .flags = XTOPT_INVERT},

	XTOPT_TABLEEND,

};

static const char f_devgroups[] = "/etc/iproute2/group";

/* array of devgroups from f_devgroups[] */

static struct xtables_lmap *devgroups;

static void devgroup_parse(struct xt_option_call *cb)

{

	struct xt_devgroup_info *info = cb->data;

	unsigned int group, mask;

	xtables_option_parse(cb);

	xtables_parse_val_mask(cb, &group, &mask, devgroups);

	switch (cb->entry->id) {

	case O_SRC_GROUP:

		info->src_group = group;

		info->src_mask  = mask;

		info->flags |= XT_DEVGROUP_MATCH_SRC;

		if (cb->invert)

			info->flags |= XT_DEVGROUP_INVERT_SRC;

		break;

	case O_DST_GROUP:

		info->dst_group = group;

		info->dst_mask  = mask;

		info->flags |= XT_DEVGROUP_MATCH_DST;

		if (cb->invert)

			info->flags |= XT_DEVGROUP_INVERT_DST;

		break;

	}

}

static void devgroup_show(const char *pfx, const struct xt_devgroup_info *info,

			  int numeric)

{

	if (info->flags & XT_DEVGROUP_MATCH_SRC) {

		if (info->flags & XT_DEVGROUP_INVERT_SRC)

			printf(" !");

		printf(" %ssrc-group", pfx);

		xtables_print_val_mask(info->src_group, info->src_mask,

				       numeric ? NULL : devgroups);

	}

	if (info->flags & XT_DEVGROUP_MATCH_DST) {

		if (info->flags & XT_DEVGROUP_INVERT_DST)

			printf(" !");

		printf(" %sdst-group", pfx);

		xtables_print_val_mask(info->dst_group, info->dst_mask,

				       numeric ? NULL : devgroups);

	}

}

static void devgroup_print(const void *ip, const struct xt_entry_match *match,

                        int numeric)

{

	const struct xt_devgroup_info *info = (const void *)match->data;

	devgroup_show("", info, numeric);

}

static void devgroup_save(const void *ip, const struct xt_entry_match *match)

{

	const struct xt_devgroup_info *info = (const void *)match->data;

	devgroup_show("--", info, 0);

}

static void devgroup_check(struct xt_fcheck_call *cb)

{

	if (cb->xflags == 0)

		xtables_error(PARAMETER_PROBLEM,

			      "devgroup match: You must specify either "

			      "'--src-group' or '--dst-group'");

}

static void

print_devgroup_xlate(unsigned int id, uint32_t op,  unsigned int mask,

		     struct xt_xlate *xl, int numeric)

{

	const char *name = NULL;

	if (mask != 0xffffffff)

		xt_xlate_add(xl, "and 0x%x %s 0x%x", mask,

			   op == XT_OP_EQ ? "==" : "!=", id);

	else {

		if (numeric == 0)

			name = xtables_lmap_id2name(devgroups, id);

		xt_xlate_add(xl, "%s", op == XT_OP_EQ ? "" : "!= ");

		if (name)

			xt_xlate_add(xl, "%s", name);

		else

			xt_xlate_add(xl, "0x%x", id);

	}

}

static void devgroup_show_xlate(const struct xt_devgroup_info *info,

				struct xt_xlate *xl, int numeric)

{

	enum xt_op op = XT_OP_EQ;

	char *space = "";

	if (info->flags & XT_DEVGROUP_MATCH_SRC) {

		if (info->flags & XT_DEVGROUP_INVERT_SRC)

			op = XT_OP_NEQ;

		xt_xlate_add(xl, "iifgroup ");

		print_devgroup_xlate(info->src_group, op,

				     info->src_mask, xl, numeric);

		space = " ";

	}

	if (info->flags & XT_DEVGROUP_MATCH_DST) {

		if (info->flags & XT_DEVGROUP_INVERT_DST)

			op = XT_OP_NEQ;

		xt_xlate_add(xl, "%soifgroup ", space);

		print_devgroup_xlate(info->dst_group, op,

				     info->dst_mask, xl, numeric);

	}

}

static int devgroup_xlate(struct xt_xlate *xl,

			  const struct xt_xlate_mt_params *params)

{

	const struct xt_devgroup_info *info = (const void *)params->match->data;

	devgroup_show_xlate(info, xl, 0);

	return 1;

}

static struct xtables_match devgroup_mt_reg = {

	.name		= "devgroup",

	.version	= XTABLES_VERSION,

	.family		= NFPROTO_UNSPEC,

	.size		= XT_ALIGN(sizeof(struct xt_devgroup_info)),

	.userspacesize	= XT_ALIGN(sizeof(struct xt_devgroup_info)),

	.help		= devgroup_help,

	.print		= devgroup_print,

	.save		= devgroup_save,

	.x6_parse	= devgroup_parse,

	.x6_fcheck	= devgroup_check,

	.x6_options	= devgroup_opts,

	.xlate		= devgroup_xlate,

};

void _init(void)

{

	devgroups = xtables_lmap_init(f_devgroups);

	if (devgroups == NULL && errno != ENOENT)

		fprintf(stderr, "Warning: %s: %s\n", f_devgroups,

			strerror(errno));

	xtables_register_match(&devgroup_mt_reg);

}