/*	$NetBSD: backupsa.c,v 1.11 2018/05/19 19:47:47 maxv Exp $	*/

/*	$KAME: backupsa.c,v 1.16 2001/12/31 20:13:40 thorpej Exp $	*/

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>

#include <netinet/in.h>
#include PATH_IPSEC_H

#if TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif

#include "var.h"
#include "misc.h"
#include "vmbuf.h"
#include "str2val.h"
#include "plog.h"
#include "debug.h"

#include "localconf.h"
#include "sockmisc.h"
#include "safefile.h"
#include "backupsa.h"
#include "libpfkey.h"

/*
 * (time string)%(sa parameter)
 * (time string) := ex. Nov 24 18:22:48 1986
 * (sa parameter) :=
 *    src dst satype spi mode reqid wsize \
 *    e_type e_keylen a_type a_keylen flags \
 *    l_alloc l_bytes l_addtime l_usetime seq keymat
 */
static char *format = "%b %d %T %Y";	/* time format */
static char *strmon[12] = {
        "Jan", "Feb", "Mar", "Apr", "May", "Jun",
        "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};

static char *str2tmx __P((char *, struct tm *));
static int str2num __P((char *, int));

/*
 * output the sa parameter.
 */
int
backupsa_to_file(sa_args)
	struct pfkey_send_sa_args *sa_args;
{
	char buf[1024];
	struct tm *tm;
	time_t t;
	char *p, *k;
	int len, l, i;
	FILE *fp;

	p = buf;
	len = sizeof(buf);

	t = time(NULL);
	tm = localtime(&t);
	l = strftime(p, len, format, tm);
	p += l;
	len -= l;
	if (len < 0)
		goto err;

	l = snprintf(p, len, "%%");
	if (l < 0 || l >= len)
		goto err;
	p += l;
	len -= l;
	if (len < 0)
		goto err;

        i = getnameinfo(sa_args->src, sysdep_sa_len(sa_args->src), p, len, NULL, 0, NIFLAGS);
	if (i != 0)
		goto err;
	l = strlen(p);
	p += l;
	len -= l;
	if (len < 0)
		goto err;

	l = snprintf(p, len, " ");
	if (l < 0 || l >= len)
		goto err;
	p += l;
	len -= l;
	if (len < 0)
		goto err;

        i = getnameinfo(sa_args->dst, sysdep_sa_len(sa_args->dst), p, len, NULL, 0, NIFLAGS);
	if (i != 0)
		goto err;
	l = strlen(p);
	p += l;
	len -= l;
	if (len < 0)
		goto err;

	l = snprintf(p, len,
		" %u %lu %u %u %u "
		"%u %u %u %u %u "
		"%u %llu %llu %llu %u",
		sa_args->satype, (unsigned long)ntohl(sa_args->spi), 
		sa_args->mode, sa_args->reqid, sa_args->wsize, sa_args->e_type, 
		sa_args->e_keylen, sa_args->a_type, sa_args->a_keylen, 
		sa_args->flags, sa_args->l_alloc, 
		(unsigned long long)sa_args->l_bytes, 
		(unsigned long long)sa_args->l_addtime, 
		(unsigned long long)sa_args->l_usetime, sa_args->seq);

	if (l < 0 || l >= len)
		goto err;
	p += l;
	len -= l;
	if (len < 0)
		goto err;

	k = val2str(sa_args->keymat, sa_args->e_keylen + sa_args->a_keylen);
	l = snprintf(p, len, " %s", k);
	racoon_free(k);
	if (l < 0 || l >= len)
		goto err;
	p += l;
	len -= l;
	if (len < 0)
		goto err;

	/* open the file and write the SA parameter */
	if (safefile(lcconf->pathinfo[LC_PATHTYPE_BACKUPSA], 1) != 0 ||
	    (fp = fopen(lcconf->pathinfo[LC_PATHTYPE_BACKUPSA], "a")) == NULL) {
		plog(LLV_ERROR, LOCATION, NULL,
			"failed to open the backup file %s.\n",
			lcconf->pathinfo[LC_PATHTYPE_BACKUPSA]);
		return -1;
	}
	fprintf(fp, "%s\n", buf);
	fclose(fp);

	return 0;

err:
	plog(LLV_ERROR, LOCATION, NULL,
		"SA cannot be saved to a file.\n");
	return -1;
}

int
backupsa_from_file()
{
	FILE *fp;
	char buf[512];
	struct tm tm;
	time_t created, current;
	char *p, *q;
	size_t keymatlen;
	int line;
	struct pfkey_send_sa_args sa_args;

	memset(&sa_args, 0, sizeof(sa_args));

	if (safefile(lcconf->pathinfo[LC_PATHTYPE_BACKUPSA], 1) == 0)
		fp = fopen(lcconf->pathinfo[LC_PATHTYPE_BACKUPSA], "r");
	else
		fp = NULL;
	if (fp == NULL) {
		plog(LLV_ERROR, LOCATION, NULL,
			"failed to open the backup file %s.\n",
			lcconf->pathinfo[LC_PATHTYPE_BACKUPSA]);
		return -1;
	}

	current = time(NULL);

	for(line = 1; fgets(buf, sizeof(buf), fp) != NULL; line++) {
		/* comment line */
		if (buf[0] == '#')
			continue;

		memset(&tm, 0, sizeof(tm));
		p = str2tmx(buf, &tm);
		if (*p != '%') {
			plog(LLV_ERROR, LOCATION, NULL,
				"illegal format line#%d in %s: %s\n",
				line, lcconf->pathinfo[LC_PATHTYPE_BACKUPSA], 
				buf);
			goto next;
		}
		created = mktime(&tm);
		p++;

		for (q = p; *q != '\0' && !isspace((int)*q); q++)
			;
		*q = '\0';
		if ((sa_args.src = str2saddr(p, NULL)) == NULL)
			goto next;
		p = q + 1;

		for (q = p; *q != '\0' && !isspace((int)*q); q++)
			;
		*q = '\0';
		if ((sa_args.dst = str2saddr(p, NULL)) == NULL)
			goto next;
		p = q + 1;

#define GETNEXTNUM(value, function) 				\
do { 								\
	char *y; 						\
	for (q = p; *q != '\0' && !isspace((int)*q); q++) 	\
		; 						\
	*q = '\0'; 						\
	(value) = function(p, &y, 10); 				\
	if ((value) == 0 && *y != '\0') 			\
		goto next; 					\
	p = q + 1; 						\
} while (/*CONSTCOND*/0);

		GETNEXTNUM(sa_args.satype, strtoul);
		GETNEXTNUM(sa_args.spi, strtoul);
		sa_args.spi = ntohl(sa_args.spi);
		GETNEXTNUM(sa_args.mode, strtoul);
		GETNEXTNUM(sa_args.reqid, strtoul);
		GETNEXTNUM(sa_args.wsize, strtoul);
		GETNEXTNUM(sa_args.e_type, strtoul);
		GETNEXTNUM(sa_args.e_keylen, strtoul);
		GETNEXTNUM(sa_args.a_type, strtoul);
		GETNEXTNUM(sa_args.a_keylen, strtoul);
		GETNEXTNUM(sa_args.flags, strtoul);
		GETNEXTNUM(sa_args.l_alloc, strtoul);
		GETNEXTNUM(sa_args.l_bytes, strtouq);
		GETNEXTNUM(sa_args.l_addtime, strtouq);
		GETNEXTNUM(sa_args.l_usetime, strtouq);
		GETNEXTNUM(sa_args.seq, strtoul);

#undef GETNEXTNUM

		sa_args.keymat = str2val(p, 16, &keymatlen);
		if (sa_args.keymat == NULL) {
			plog(LLV_ERROR, LOCATION, NULL,
				"illegal format(keymat) line#%d in %s: %s\n",
				line, lcconf->pathinfo[LC_PATHTYPE_BACKUPSA], 
				buf);
			goto next;
		}

		if (created + sa_args.l_addtime < current) {
			plog(LLV_DEBUG, LOCATION, NULL,
				"ignore this line#%d in %s due to expiration\n",
				line, lcconf->pathinfo[LC_PATHTYPE_BACKUPSA]);
			goto next;
		}
		sa_args.l_addtime -= current - created;

		if (pfkey_send_add2(&sa_args) < 0) {
			plog(LLV_ERROR, LOCATION, NULL,
				"restore SA failed line#%d in %s: %s\n",
				line, lcconf->pathinfo[LC_PATHTYPE_BACKUPSA], 
				ipsec_strerror());
		}

next:
	 	if (sa_args.src != NULL) {
			racoon_free(sa_args.src);
			sa_args.src = NULL;
		}
		if (sa_args.dst != NULL) {
			racoon_free(sa_args.dst);
			sa_args.dst = NULL;
		}
		if (sa_args.keymat != NULL) {
			racoon_free(sa_args.keymat);
			sa_args.keymat = NULL;
		}
	}

	fclose(fp);

	/*
	 * There is a possibility that an abnormal system down will happen
	 * again before new negotiation will be started.  so racoon clears
	 * the backup file here.  it's ok that old SAs are remained in the
	 * file.  any old SA will not be installed because racoon checks the
	 * lifetime and compare with current time.
	 */

	return 0;
}

int
backupsa_clean()
{
	FILE *fp;

	/* simply return if the file is not defined. */
	if (!lcconf->pathinfo[LC_PATHTYPE_BACKUPSA])
		return 0;

	fp = fopen(lcconf->pathinfo[LC_PATHTYPE_BACKUPSA], "w+");
	if (fp == NULL) {
		plog(LLV_ERROR, LOCATION, NULL,
			"failed to clean the backup file %s.\n",
			lcconf->pathinfo[LC_PATHTYPE_BACKUPSA]);
		return -1;
	}
	fclose(fp);
	return 0;
}

/*
 * convert fixed string into the tm structure.
 * The fixed string is like 'Nov 24 18:22:48 1986'.
 * static char *format = "%b %d %T %Y";
 */
static char *
str2tmx(char *p, struct tm *tm)
{
	int i, len;

	/* Month */
        for (i = 0; i < sizeof(strmon)/sizeof(strmon[0]); i++) {
		if (strncasecmp(p, strmon[i], strlen(strmon[i])) == 0) {
			tm->tm_mon = i;
			break;
		}
	}
	if (i == sizeof(strmon)/sizeof(strmon[0]))
		return 0;
	p += strlen(strmon[i]);
	if (*p++ != ' ')
		return 0;

	/* Day */
	len = 2;
	tm->tm_mday = str2num(p, len);
	if (tm->tm_mday == -1 || tm->tm_mday > 31)
		return 0;
	p += len;
	if (*p++ != ' ')
		return 0;

	/* Hour */
	len = 2;
	tm->tm_hour = str2num(p, len);
	if (tm->tm_hour == -1 || tm->tm_hour > 24)
		return 0;
	p += len;
	if (*p++ != ':')
		return 0;

	/* Min */
	len = 2;
	tm->tm_min = str2num(p, len);
	if (tm->tm_min == -1 || tm->tm_min > 60)
		return 0;
	p += len;
	if (*p++ != ':')
		return 0;

	/* Sec */
	len = 2;
	tm->tm_sec = str2num(p, len);
	if (tm->tm_sec == -1 || tm->tm_sec > 60)
		return 0;
	p += len;
	if (*p++ != ' ')
		return 0;

	/* Year */
	len = 4;
	tm->tm_year = str2num(p, len);
	if (tm->tm_year == -1 || tm->tm_year < 1900)
		return 0;
	tm->tm_year -= 1900;
	p += len;

	return p;
}

static int
str2num(p, len)
	char *p;
	int len;
{
	int res, i;

	res = 0;
        for (i = len; i > 0; i--) {
		if (!isdigit((int)*p))
			return -1;
		res *= 10;
		res += *p - '0';
		p++;
	}

	return res;
}

#ifdef TEST
#include <stdio.h>
int
main()
{
	struct tm tm;
	time_t t;
	char *buf = "Nov 24 18:22:48 1986 ";
	const char *p;

	memset(&tm, 0, sizeof(tm));
	p = str2tmx(buf, &tm);
	printf("[%x]\n", *p);
	t = mktime(&tm);
	if (t == -1)
		printf("mktime failed.");
	if ((p = ctime(&t)) == NULL)
		p = "?";
	printf("[%s]\n", p);

	exit(0);
}
#endif