/* Code to save the xtables state, in human readable-form. */

/* (C) 1999 by Paul 'Rusty' Russell <rusty@rustcorp.com.au> and

 * (C) 2000-2002 by Harald Welte <laforge@gnumonks.org>

 * (C) 2012 by Pablo Neira Ayuso <pablo@netfilter.org>

 *

 * This code is distributed under the terms of GNU GPL v2

 *

 */

#include "config.h"

#include <getopt.h>

#include <errno.h>

#include <libgen.h>

#include <stdio.h>

#include <fcntl.h>

#include <stdlib.h>

#include <string.h>

#include <time.h>

#include <netdb.h>

#include <unistd.h>

#include "libiptc/libiptc.h"

#include "iptables.h"

#include "xtables-multi.h"

#include "nft.h"

#include "nft-cache.h"

#include <libnftnl/chain.h>

#ifndef NO_SHARED_LIBS

#include <dlfcn.h>

#endif

#define prog_name xtables_globals.program_name

#define prog_vers xtables_globals.program_version

static const char *ipt_save_optstring = "bcdt:M:f:V";

static const struct option ipt_save_options[] = {

	{.name = "counters", .has_arg = false, .val = 'c'},

	{.name = "version",  .has_arg = false, .val = 'V'},

	{.name = "dump",     .has_arg = false, .val = 'd'},

	{.name = "table",    .has_arg = true,  .val = 't'},

	{.name = "modprobe", .has_arg = true,  .val = 'M'},

	{.name = "file",     .has_arg = true,  .val = 'f'},

	{NULL},

};

static const char *arp_save_optstring = "cM:V";

static const struct option arp_save_options[] = {

	{.name = "counters", .has_arg = false, .val = 'c'},

	{.name = "version",  .has_arg = false, .val = 'V'},

	{.name = "modprobe", .has_arg = true,  .val = 'M'},

	{NULL},

};

static const char *ebt_save_optstring = "ct:M:V";

static const struct option ebt_save_options[] = {

	{.name = "counters", .has_arg = false, .val = 'c'},

	{.name = "version",  .has_arg = false, .val = 'V'},

	{.name = "table",    .has_arg = true,  .val = 't'},

	{.name = "modprobe", .has_arg = true,  .val = 'M'},

	{NULL},

};

struct do_output_data {

	unsigned int format;

	bool commit;

};

static int

__do_output(struct nft_handle *h, const char *tablename, void *data)

{

	struct nftnl_chain_list *chain_list;

	struct do_output_data *d = data;

	time_t now;

	if (!nft_table_builtin_find(h, tablename))

		return 0;

	if (!nft_is_table_compatible(h, tablename, NULL)) {

		printf("# Table `%s' is incompatible, use 'nft' tool.\n",

		       tablename);

		return 0;

	}

	chain_list = nft_chain_list_get(h, tablename, NULL);

	if (!chain_list)

		return 0;

	now = time(NULL);

	printf("# Generated by %s v%s on %s", prog_name,

	       prog_vers, ctime(&now));

	printf("*%s\n", tablename);

	/* Dump out chain names first,

	 * thereby preventing dependency conflicts */

	nft_chain_save(h, chain_list);

	nft_rule_save(h, tablename, d->format);

	if (d->commit)

		printf("COMMIT\n");

	now = time(NULL);

	printf("# Completed on %s", ctime(&now));

	return 0;

}

static int

do_output(struct nft_handle *h, const char *tablename, struct do_output_data *d)

{

	int ret;

	if (!tablename) {

		ret = nft_for_each_table(h, __do_output, d);

		nft_check_xt_legacy(h->family, true);

		return !!ret;

	}

	if (!nft_table_find(h, tablename) &&

	    !nft_table_builtin_find(h, tablename)) {

		fprintf(stderr, "Table `%s' does not exist\n", tablename);

		return 1;

	}

	ret = __do_output(h, tablename, d);

	nft_check_xt_legacy(h->family, true);

	return ret;

}

/* Format:

 * :Chain name POLICY packets bytes

 * rule

 */

static int

xtables_save_main(int family, int argc, char *argv[],

		  const char *optstring, const struct option *longopts)

{

	const struct builtin_table *tables;

	const char *tablename = NULL;

	struct do_output_data d = {

		.format = FMT_NOCOUNTS,

	};

	struct nft_handle h;

	bool dump = false;

	FILE *file = NULL;

	int ret, c;

	xtables_globals.program_name = basename(*argv);;

	c = xtables_init_all(&xtables_globals, family);

	if (c < 0) {

		fprintf(stderr, "%s/%s Failed to initialize xtables\n",

				xtables_globals.program_name,

				xtables_globals.program_version);

		exit(1);

	}

	while ((c = getopt_long(argc, argv, optstring, longopts, NULL)) != -1) {

		switch (c) {

		case 'b':

			fprintf(stderr, "-b/--binary option is not implemented\n");

			break;

		case 'c':

			d.format &= ~FMT_NOCOUNTS;

			break;

		case 't':

			/* Select specific table. */

			tablename = optarg;

			break;

		case 'M':

			xtables_modprobe_program = optarg;

			break;

		case 'f':

			file = fopen(optarg, "w");

			if (file == NULL) {

				fprintf(stderr, "Failed to open file, error: %s\n",

					strerror(errno));

				exit(1);

			}

			ret = dup2(fileno(file), STDOUT_FILENO);

			if (ret == -1) {

				fprintf(stderr, "Failed to redirect stdout, error: %s\n",

					strerror(errno));

				exit(1);

			}

			fclose(file);

			break;

		case 'd':

			dump = true;

			break;

		case 'V':

			printf("%s v%s (nf_tables)\n", prog_name, prog_vers);

			exit(0);

		default:

			fprintf(stderr,

				"Look at manual page `%s.8' for more information.\n",

				prog_name);

			exit(1);

		}

	}

	if (optind < argc) {

		fprintf(stderr, "Unknown arguments found on commandline\n");

		exit(1);

	}

	switch (family) {

	case NFPROTO_IPV4:

	case NFPROTO_IPV6: /* fallthough, same table */

#if defined(ALL_INCLUSIVE) || defined(NO_SHARED_LIBS)

		init_extensions();

		init_extensions4();

#endif

		tables = xtables_ipv4;

		d.commit = true;

		break;

	case NFPROTO_ARP:

		tables = xtables_arp;

		break;

	case NFPROTO_BRIDGE: {

		const char *ctr = getenv("EBTABLES_SAVE_COUNTER");

		if (!(d.format & FMT_NOCOUNTS)) {

			d.format |= FMT_EBT_SAVE;

		} else if (ctr && !strcmp(ctr, "yes")) {

			d.format &= ~FMT_NOCOUNTS;

			d.format |= FMT_C_COUNTS | FMT_EBT_SAVE;

		}

		tables = xtables_bridge;

		break;

	}

	default:

		fprintf(stderr, "Unknown family %d\n", family);

		return 1;

	}

	if (nft_init(&h, family, tables) < 0) {

		fprintf(stderr, "%s/%s Failed to initialize nft: %s\n",

				xtables_globals.program_name,

				xtables_globals.program_version,

				strerror(errno));

		exit(EXIT_FAILURE);

	}

	ret = do_output(&h, tablename, &d);

	nft_fini(&h);

	if (dump)

		exit(0);

	return ret;

}

int xtables_ip4_save_main(int argc, char *argv[])

{

	return xtables_save_main(NFPROTO_IPV4, argc, argv,

				 ipt_save_optstring, ipt_save_options);

}

int xtables_ip6_save_main(int argc, char *argv[])

{

	return xtables_save_main(NFPROTO_IPV6, argc, argv,

				 ipt_save_optstring, ipt_save_options);

}

int xtables_eb_save_main(int argc, char *argv[])

{

	return xtables_save_main(NFPROTO_BRIDGE, argc, argv,

				 ebt_save_optstring, ebt_save_options);

}

int xtables_arp_save_main(int argc, char *argv[])

{

	return xtables_save_main(NFPROTO_ARP, argc, argv,

				 arp_save_optstring, arp_save_options);

}