iptables-save.c

/* Code to save the iptables 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>
 *
 * This code is distributed under the terms of GNU GPL v2
 *
 */
#include <getopt.h>
#include <sys/errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <netdb.h>
#include "libiptc/libiptc.h"
#include "iptables.h"
#include "iptables-multi.h"

#ifndef NO_SHARED_LIBS
#include <dlfcn.h>
#endif

static int show_counters = 0;

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'},
	{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];

	procfile = fopen("/proc/net/ip_tables_names", "re");
	if (!procfile)
		return ret;

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

	time_t now = time(NULL);

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

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

		printf(":%s ", chain);
		if (iptc_builtin(chain, h)) {
			struct xt_counters count;
			printf("%s ",
			       iptc_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 = iptc_first_chain(h);
	     chain;
	     chain = iptc_next_chain(h)) {
		const struct ipt_entry *e;

		/* Dump out rules */
		e = iptc_first_rule(chain, h);
		while(e) {
			print_rule4(e, h, chain, show_counters);
			e = iptc_next_rule(e, h);
		}
	}

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

	return 1;
}

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

	iptables_globals.program_name = "iptables-save";
	c = xtables_init_all(&iptables_globals, NFPROTO_IPV4);
	if (c < 0) {
		fprintf(stderr, "%s/%s Failed to initialize xtables\n",
				iptables_globals.program_name,
				iptables_globals.program_version);
		exit(1);
	}
#if defined(ALL_INCLUSIVE) || defined(NO_SHARED_LIBS)
	init_extensions();
	init_extensions4();
#endif

	while ((c = getopt_long(argc, argv, "bcdt:", options, NULL)) != -1) {
		switch (c) {
		case 'c':
			show_counters = 1;
			break;

		case 't':
			/* Select specific table. */
			tablename = optarg;
			break;
		case 'M':
			xtables_modprobe_program = optarg;
			break;
		case 'd':
			do_output(tablename);
			exit(0);
		}
	}

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

	return !do_output(tablename);
}