/* Code to save the ip6tables state, in human readable-form. */
/* Author:  Andras Kis-Szabo <kisza@sch.bme.hu>
 * Original code: iptables-save
 * Authors: Paul 'Rusty' Russel <rusty@linuxcare.com.au> and
 *          Harald Welte <laforge@gnumonks.org>
 * This code is distributed under the terms of GNU GPL v2
 */
#include <getopt.h>
#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <unistd.h>
#include "libiptc/libip6tc.h"
#include "ip6tables.h"
#include "ip6tables-multi.h"

#define prog_name ip6tables_globals.program_name
#define prog_vers ip6tables_globals.program_version

static int show_counters;

static const struct option options[] = {
	{.name = "counters", .has_arg = false, .val = 'c'},
	{.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'},
	{.name = "version",  .has_arg = false, .val = 'V'},
	{NULL},
};


/* Debugging prototype. */
static int for_each_table(int (*func)(const char *tablename))
{
	int ret = 1;
	FILE *procfile = NULL;
	char tablename[XT_TABLE_MAXNAMELEN+1];
	static const char filename[] = "/proc/net/ip6_tables_names";

	procfile = fopen(filename, "re");
	if (!procfile) {
		if (errno == ENOENT)
			return ret;
		fprintf(stderr, "Failed to list table names in %s: %s\n",
		        filename, strerror(errno));
		exit(1);
	}

	while (fgets(tablename, sizeof(tablename), procfile)) {
		if (tablename[strlen(tablename) - 1] != '\n')
			xtables_error(OTHER_PROBLEM,
				   "Badly formed tablename `%s'\n",
				   tablename);
		tablename[strlen(tablename) - 1] = '\0';
		ret &= func(tablename);
	}

	fclose(procfile);
	return ret;
}


static int do_output(const char *tablename)
{
	struct xtc_handle *h;
	const char *chain = NULL;

	if (!tablename)
		return for_each_table(&do_output);

	h = ip6tc_init(tablename);
	if (h == NULL) {
		xtables_load_ko(xtables_modprobe_program, false);
		h = ip6tc_init(tablename);
	}
	if (!h)
		xtables_error(OTHER_PROBLEM, "Cannot initialize: %s\n",
			   ip6tc_strerror(errno));

	time_t now = time(NULL);

	printf("# Generated by ip6tables-save v%s on %s",
	       IPTABLES_VERSION, ctime(&now));
	printf("*%s\n", tablename);

	/* Dump out chain names first,
	 * thereby preventing dependency conflicts */
	for (chain = ip6tc_first_chain(h);
	     chain;
	     chain = ip6tc_next_chain(h)) {

		printf(":%s ", chain);
		if (ip6tc_builtin(chain, h)) {
			struct xt_counters count;
			printf("%s ",
			       ip6tc_get_policy(chain, &count, h));
			printf("[%llu:%llu]\n", (unsigned long long)count.pcnt, (unsigned long long)count.bcnt);
		} else {
			printf("- [0:0]\n");
		}
	}

	for (chain = ip6tc_first_chain(h);
	     chain;
	     chain = ip6tc_next_chain(h)) {
		const struct ip6t_entry *e;

		/* Dump out rules */
		e = ip6tc_first_rule(chain, h);
		while(e) {
			print_rule6(e, h, chain, show_counters);
			e = ip6tc_next_rule(e, h);
		}
	}

	now = time(NULL);
	printf("COMMIT\n");
	printf("# Completed on %s", ctime(&now));
	ip6tc_free(h);

	return 1;
}

/* Format:
 * :Chain name POLICY packets bytes
 * rule
 */
int ip6tables_save_main(int argc, char *argv[])
{
	const char *tablename = NULL;
	FILE *file = NULL;
	int ret, c;

	ip6tables_globals.program_name = "ip6tables-save";
	c = xtables_init_all(&ip6tables_globals, NFPROTO_IPV6);
	if (c < 0) {
		fprintf(stderr, "%s/%s Failed to initialize xtables\n",
				ip6tables_globals.program_name,
				ip6tables_globals.program_version);
		exit(1);
	}
#if defined(ALL_INCLUSIVE) || defined(NO_SHARED_LIBS)
	init_extensions();
	init_extensions6();
#endif

	while ((c = getopt_long(argc, argv, "bcdt:M:f:V", options, NULL)) != -1) {
		switch (c) {
		case 'b':
			fprintf(stderr, "-b/--binary option is not implemented\n");
			break;
		case 'c':
			show_counters = 1;
			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':
			do_output(tablename);
			exit(0);
		case 'V':
			printf("%s v%s (legacy)\n", prog_name, prog_vers);
			exit(0);
		default:
			fprintf(stderr,
				"Look at manual page `ip6tables-save.8' for more information.\n");
			exit(1);
		}
	}

	if (optind < argc) {
		fprintf(stderr, "Unknown arguments found on commandline\n");
		exit(1);
	}

	return !do_output(tablename);
}