/* $OpenBSD: util.c,v 1.37 2004/04/15 18:39:26 deraadt Exp $	 */
/* $EOM: util.c,v 1.23 2000/11/23 12:22:08 niklas Exp $	 */

/*
 * Copyright (c) 1998, 1999, 2001 Niklas Hallqvist.  All rights reserved.
 * Copyright (c) 2000, 2001 Håkan Olsson.  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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/*
 * This code was written under funding by Ericsson Radio Systems.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <limits.h>
#include <netdb.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>

#include "sysdep.h"

#include "log.h"
#include "message.h"
#include "monitor.h"
#include "sysdep.h"
#include "transport.h"
#include "util.h"

/*
 * Set if -N is given, allowing name lookups to be done, possibly stalling
 * the daemon for quite a while.
 */
int	allow_name_lookups = 0;

/*
 * This is set to true in case of regression-test mode, when it will
 * cause predictable random numbers be generated.
 */
int	regrand = 0;

/*
 * If in regression-test mode, this is the seed used.
 */
u_long	seed;

/*
 * XXX These might be turned into inlines or macros, maybe even
 * machine-dependent ones, for performance reasons.
 */
u_int16_t
decode_16(u_int8_t *cp)
{
	return cp[0] << 8 | cp[1];
}

u_int32_t
decode_32(u_int8_t *cp)
{
	return cp[0] << 24 | cp[1] << 16 | cp[2] << 8 | cp[3];
}

u_int64_t
decode_64(u_int8_t *cp)
{
	return (u_int64_t) cp[0] << 56 | (u_int64_t) cp[1] << 48 |
	    (u_int64_t) cp[2] << 40 | (u_int64_t) cp[3] << 32 |
	    cp[4] << 24 | cp[5] << 16 | cp[6] << 8 | cp[7];
}

#if 0
/*
 * XXX I severly doubt that we will need this.  IPv6 does not have the legacy
 * of representation in host byte order, AFAIK.
 */

void
decode_128(u_int8_t *cp, u_int8_t *cpp)
{
#if BYTE_ORDER == LITTLE_ENDIAN
	int	i;

	for (i = 0; i < 16; i++)
		cpp[i] = cp[15 - i];
#elif BYTE_ORDER == BIG_ENDIAN
	bcopy(cp, cpp, 16);
#else
#error "Byte order unknown!"
#endif
}
#endif

void
encode_16(u_int8_t *cp, u_int16_t x)
{
	*cp++ = x >> 8;
	*cp = x & 0xff;
}

void
encode_32(u_int8_t *cp, u_int32_t x)
{
	*cp++ = x >> 24;
	*cp++ = (x >> 16) & 0xff;
	*cp++ = (x >> 8) & 0xff;
	*cp = x & 0xff;
}

void
encode_64(u_int8_t *cp, u_int64_t x)
{
	*cp++ = x >> 56;
	*cp++ = (x >> 48) & 0xff;
	*cp++ = (x >> 40) & 0xff;
	*cp++ = (x >> 32) & 0xff;
	*cp++ = (x >> 24) & 0xff;
	*cp++ = (x >> 16) & 0xff;
	*cp++ = (x >> 8) & 0xff;
	*cp = x & 0xff;
}

#if 0
/*
 * XXX I severly doubt that we will need this.  IPv6 does not have the legacy
 * of representation in host byte order, AFAIK.
 */

void
encode_128(u_int8_t *cp, u_int8_t *cpp)
{
	decode_128(cpp, cp);
}
#endif

/* Check a buffer for all zeroes.  */
int
zero_test(const u_int8_t *p, size_t sz)
{
	while (sz-- > 0)
		if (*p++ != 0)
			return 0;
	return 1;
}

/* Check a buffer for all ones.  */
int
ones_test(const u_int8_t *p, size_t sz)
{
	while (sz-- > 0)
		if (*p++ != 0xff)
			return 0;
	return 1;
}

/*
 * Generate a random data, len bytes long.
 */
u_int8_t *
getrandom(u_int8_t *buf, size_t len)
{
	u_int32_t	tmp = 0;
	size_t		i;

	for (i = 0; i < len; i++) {
		if (i % sizeof tmp == 0)
			tmp = sysdep_random();

		buf[i] = tmp & 0xff;
		tmp >>= 8;
	}

	return buf;
}

static __inline int
hex2nibble(char c)
{
	if (c >= '0' && c <= '9')
		return c - '0';
	if (c >= 'a' && c <= 'f')
		return c - 'a' + 10;
	if (c >= 'A' && c <= 'F')
		return c - 'A' + 10;
	return -1;
}

/*
 * Convert hexadecimal string in S to raw binary buffer at BUF sized SZ
 * bytes.  Return 0 if everything is OK, -1 otherwise.
 */
int
hex2raw(char *s, u_int8_t *buf, size_t sz)
{
	u_int8_t *bp;
	char	*p;
	int	tmp;

	if (strlen(s) > sz * 2)
		return -1;
	for (p = s + strlen(s) - 1, bp = &buf[sz - 1]; bp >= buf; bp--) {
		*bp = 0;
		if (p >= s) {
			tmp = hex2nibble(*p--);
			if (tmp == -1)
				return -1;
			*bp = tmp;
		}
		if (p >= s) {
			tmp = hex2nibble(*p--);
			if (tmp == -1)
				return -1;
			*bp |= tmp << 4;
		}
	}
	return 0;
}

int
text2sockaddr(char *address, char *port, struct sockaddr ** sa)
{
#ifdef HAVE_GETNAMEINFO
	struct addrinfo *ai, hints;

	memset(&hints, 0, sizeof hints);
	if (!allow_name_lookups)
		hints.ai_flags = AI_NUMERICHOST;
	hints.ai_family = PF_UNSPEC;
	hints.ai_socktype = SOCK_DGRAM;
	hints.ai_protocol = IPPROTO_UDP;

	if (getaddrinfo(address, port, &hints, &ai))
		return -1;

	*sa = malloc(sysdep_sa_len(ai->ai_addr));
	if (!sa)
		return -1;

	memcpy(*sa, ai->ai_addr, sysdep_sa_len(ai->ai_addr));
	freeaddrinfo(ai);
	return 0;
#else
	int	af = strchr(address, ':') != NULL ? AF_INET6 : AF_INET;
	size_t	sz = af == AF_INET ? sizeof(struct sockaddr_in) :
	    sizeof(struct sockaddr_in6);
	long	lport;
	struct servent *sp;
	char	*ep;

	*sa = calloc(1, sz);
	if (!*sa)
		return -1;

#ifndef USE_OLD_SOCKADDR
	(*sa)->sa_len = sz;
#endif
	(*sa)->sa_family = af;
	if (inet_pton(af, address, sockaddr_addrdata(*sa)) != 1) {
		free(*sa);
		return -1;
	}
	if (!port)
		return 0;
	sp = getservbyname(port, "udp");
	if (!sp) {
		lport = strtol(port, &ep, 10);
		if (ep == port || lport < 0 || lport > (long) USHRT_MAX) {
			free(*sa);
			return -1;
		}
		lport = htons(lport);
	} else
		lport = sp->s_port;
	if ((*sa)->sa_family == AF_INET)
		((struct sockaddr_in *) *sa)->sin_port = lport;
	else
		((struct sockaddr_in6 *) *sa)->sin6_port = lport;
	return 0;
#endif
}

/*
 * Convert a sockaddr to text. With zflag non-zero fill out with zeroes,
 * i.e 10.0.0.10 --> "010.000.000.010"
 */
int
sockaddr2text(struct sockaddr *sa, char **address, int zflag)
{
	char	buf[NI_MAXHOST], *token, *bstart, *ep;
	int	addrlen, i, j;
	long	val;

#ifdef HAVE_GETNAMEINFO
	if (getnameinfo(sa, sysdep_sa_len(sa), buf, sizeof buf, 0, 0,
			allow_name_lookups ? 0 : NI_NUMERICHOST))
		return -1;
#else
	switch (sa->sa_family) {
	case AF_INET:
	case AF_INET6:
		if (inet_ntop(sa->sa_family, sa->sa_data, buf, NI_MAXHOST - 1) == NULL) {
			log_error("sockaddr2text: inet_ntop (%d, %p, %p, %d) failed",
			    sa->sa_family, sa->sa_data, buf, NI_MAXHOST - 1);
			return -1;
		}
		buf[NI_MAXHOST - 1] = '\0';
		break;

	default:
		log_print("sockaddr2text: unsupported protocol family %d\n",
			  sa->sa_family);
		return -1;
	}
#endif

	if (zflag == 0) {
		*address = strdup(buf);
		if (!*address)
			return -1;
	} else
		switch (sa->sa_family) {
		case AF_INET:
			addrlen = sizeof "000.000.000.000";
			*address = malloc(addrlen);
			if (!*address)
				return -1;
			buf[addrlen] = '\0';
			bstart = buf;
			**address = '\0';
			while ((token = strsep(&bstart, ".")) != NULL) {
				if (strlen(*address) > 12) {
					free(*address);
					return -1;
				}
				val = strtol(token, &ep, 10);
				if (ep == token || val < (long) 0 ||
				    val > (long) UCHAR_MAX) {
					free(*address);
					return -1;
				}
				snprintf(*address + strlen(*address),
				    addrlen - strlen(*address), "%03ld", val);
				if (bstart)
					strlcat(*address, ".", addrlen);
			}
			break;

		case AF_INET6:
			/*
			 * XXX In the algorithm below there are some magic numbers we
			 * probably could give explaining names.
			 */
			addrlen = sizeof "0000:0000:0000:0000:0000:0000:0000:0000";
			*address = malloc(addrlen);
			if (!*address)
				return -1;

			for (i = 0, j = 0; i < 8; i++) {
				snprintf((*address) + j, addrlen - j, "%02x%02x",
				    ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr[2*i],
				    ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr[2*i + 1]);
				j += 4;
				(*address)[j] = (j < (addrlen - 1)) ? ':' : '\0';
				j++;
			}
			break;

		default:
			*address = strdup("<error>");
			if (!*address)
				return -1;
		}

	return 0;
}

/*
 * sockaddr_addrlen and sockaddr_addrdata return the relevant sockaddr info
 * depending on address family.  Useful to keep other code shorter(/clearer?).
 */
int
sockaddr_addrlen(struct sockaddr *sa)
{
	switch (sa->sa_family) {
	case AF_INET6:
		return sizeof((struct sockaddr_in6 *) sa)->sin6_addr.s6_addr;
	case AF_INET:
		return sizeof((struct sockaddr_in *) sa)->sin_addr.s_addr;
	default:
		log_print("sockaddr_addrlen: unsupported protocol family %d",
		    sa->sa_family);
		return 0;
	}
}

u_int8_t *
sockaddr_addrdata(struct sockaddr *sa)
{
	switch (sa->sa_family) {
	case AF_INET6:
		return (u_int8_t *) & ((struct sockaddr_in6 *) sa)->sin6_addr.s6_addr;
	case AF_INET:
		return (u_int8_t *) & ((struct sockaddr_in *) sa)->sin_addr.s_addr;
	default:
		log_print("sockaddr_addrdata: unsupported protocol family %d",
		    sa->sa_family);
		return 0;
	}
}

in_port_t
sockaddr_port(struct sockaddr *sa)
{
	switch (sa->sa_family) {
	case AF_INET6:
		return ((struct sockaddr_in6 *) sa)->sin6_port;
	case AF_INET:
		return ((struct sockaddr_in *) sa)->sin_port;
	default:
		log_print("sockaddr_port: unsupported protocol family %d",
		    sa->sa_family);
		return 0;
	}
}

/*
 * Convert network address to text. The network address does not need
 * to be properly aligned.
 */
void
util_ntoa(char **buf, int af, u_int8_t *addr)
{
	struct sockaddr_storage from;
	struct sockaddr *sfrom = (struct sockaddr *) & from;
	socklen_t	fromlen = sizeof from;

	memset(&from, 0, fromlen);
	sfrom->sa_family = af;
#ifndef USE_OLD_SOCKADDR
	switch (af) {
	case AF_INET:
		sfrom->sa_len = sizeof(struct sockaddr_in);
		break;
	case AF_INET6:
		sfrom->sa_len = sizeof(struct sockaddr_in6);
		break;
	}
#endif
	memcpy(sockaddr_addrdata(sfrom), addr, sockaddr_addrlen(sfrom));

	if (sockaddr2text(sfrom, buf, 0)) {
		log_print("util_ntoa: "
		    "could not make printable address out of sockaddr %p", sfrom);
		*buf = 0;
	}
}

/*
 * Perform sanity check on files containing secret information.
 * Returns -1 on failure, 0 otherwise.
 * Also, if FILE_SIZE is a not a null pointer, store file size here.
 */
int
check_file_secrecy(char *name, size_t *file_size)
{
	struct stat st;

	if (monitor_stat(name, &st) == -1) {
		log_error("check_file_secrecy: stat (\"%s\") failed", name);
		return -1;
	}
	if (st.st_uid != 0 && st.st_uid != getuid()) {
		log_print("check_file_secrecy: "
		    "not loading %s - file owner is not process user", name);
		errno = EPERM;
		return -1;
	}
	if ((st.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
		log_print("conf_file_secrecy: not loading %s - too open permissions",
		    name);
		errno = EPERM;
		return -1;
	}
	if (file_size)
		*file_size = (size_t) st.st_size;

	return 0;
}