libvirt/src/util/viruuid.c
Martin Kletzander daedff47ae Use K&R style for curly braces in src/util/
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-03-20 17:16:18 +01:00

339 lines
7.8 KiB
C

/*
* viruuid.c: helper APIs for dealing with UUIDs
*
* Copyright (C) 2007-2014 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*
* Authors:
* Mark McLoughlin <markmc@redhat.com>
*/
#include <config.h>
#include "viruuid.h"
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>
#include "c-ctype.h"
#include "internal.h"
#include "virutil.h"
#include "virerror.h"
#include "virlog.h"
#include "viralloc.h"
#include "virfile.h"
#include "virrandom.h"
VIR_LOG_INIT("util.uuid");
#ifndef ENODATA
# define ENODATA EIO
#endif
static unsigned char host_uuid[VIR_UUID_BUFLEN];
static int
virUUIDGenerateRandomBytes(unsigned char *buf,
int buflen)
{
int fd;
if ((fd = open("/dev/urandom", O_RDONLY)) < 0)
return errno;
while (buflen > 0) {
int n;
if ((n = read(fd, buf, buflen)) <= 0) {
if (errno == EINTR)
continue;
VIR_FORCE_CLOSE(fd);
return n < 0 ? errno : ENODATA;
}
buf += n;
buflen -= n;
}
VIR_FORCE_CLOSE(fd);
return 0;
}
static int
virUUIDGeneratePseudoRandomBytes(unsigned char *buf,
int buflen)
{
while (buflen > 0) {
*buf++ = virRandomBits(8);
buflen--;
}
return 0;
}
/**
* virUUIDGenerate:
* @uuid: array of VIR_UUID_BUFLEN bytes to store the new UUID
*
* Generates a randomized unique identifier.
*
* Returns 0 in case of success and -1 in case of failure
*/
int
virUUIDGenerate(unsigned char *uuid)
{
int err;
if (uuid == NULL)
return -1;
if ((err = virUUIDGenerateRandomBytes(uuid, VIR_UUID_BUFLEN))) {
char ebuf[1024];
VIR_WARN("Falling back to pseudorandom UUID,"
" failed to generate random bytes: %s",
virStrerror(err, ebuf, sizeof(ebuf)));
err = virUUIDGeneratePseudoRandomBytes(uuid, VIR_UUID_BUFLEN);
}
/*
* Make UUID RFC 4122 compliant. Following form will be used:
*
* xxxxxxxx-xxxx-Axxx-Bxxx-xxxxxxxxxxxx
*
* where
* A is version defined in 4.1.3 of RFC
* Msb0 Msb1 Msb2 Msb3 Version Description
* 0 1 0 0 4 The randomly or pseudo-
* randomly generated version
* specified in this document.
*
* B is variant defined in 4.1.1 of RFC
* Msb0 Msb1 Msb2 Description
* 1 0 x The variant specified in this document.
*/
uuid[6] = (uuid[6] & 0x0F) | (4 << 4);
uuid[8] = (uuid[8] & 0x3F) | (2 << 6);
return err;
}
/**
* virUUIDParse:
* @uuidstr: zero terminated string representation of the UUID
* @uuid: array of VIR_UUID_BUFLEN bytes to store the raw UUID
*
* Parses the external string representation, allowing spaces and '-'
* character in the sequence, and storing the result as a raw UUID
*
* Returns 0 in case of success and -1 in case of error.
*/
int
virUUIDParse(const char *uuidstr, unsigned char *uuid)
{
const char *cur;
size_t i;
/*
* do a liberal scan allowing '-' and ' ' anywhere between character
* pairs, and surrounding whitespace, as long as there are exactly
* 32 hexadecimal digits the end.
*/
cur = uuidstr;
while (c_isspace(*cur))
cur++;
for (i = 0; i < VIR_UUID_BUFLEN;) {
uuid[i] = 0;
if (*cur == 0)
goto error;
if ((*cur == '-') || (*cur == ' ')) {
cur++;
continue;
}
if (!c_isxdigit(*cur))
goto error;
uuid[i] = virHexToBin(*cur);
uuid[i] *= 16;
cur++;
if (*cur == 0)
goto error;
if (!c_isxdigit(*cur))
goto error;
uuid[i] += virHexToBin(*cur);
i++;
cur++;
}
while (*cur) {
if (!c_isspace(*cur))
goto error;
cur++;
}
return 0;
error:
return -1;
}
/**
* virUUIDFormat:
* @uuid: array of VIR_UUID_RAW_LEN bytes to store the raw UUID
* @uuidstr: array of VIR_UUID_STRING_BUFLEN bytes to store the
* string representation of the UUID in. The resulting string
* will be NULL terminated.
*
* Converts the raw UUID into printable format, with embedded '-'
*
* Returns a pointer to the resulting character string.
*/
const char *
virUUIDFormat(const unsigned char *uuid, char *uuidstr)
{
snprintf(uuidstr, VIR_UUID_STRING_BUFLEN,
"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
uuid[0], uuid[1], uuid[2], uuid[3],
uuid[4], uuid[5], uuid[6], uuid[7],
uuid[8], uuid[9], uuid[10], uuid[11],
uuid[12], uuid[13], uuid[14], uuid[15]);
uuidstr[VIR_UUID_STRING_BUFLEN-1] = '\0';
return uuidstr;
}
/**
* virUUIDIsValid
*
* @uuid: The UUID to test
*
* Do some basic tests to check whether the given UUID is
* valid as a host UUID.
* Basic tests:
* - Not all of the digits may be equal
*/
int
virUUIDIsValid(unsigned char *uuid)
{
size_t i;
unsigned int ctr = 1;
unsigned char c;
if (!uuid)
return 0;
c = uuid[0];
for (i = 1; i < VIR_UUID_BUFLEN; i++)
if (uuid[i] == c)
ctr++;
return ctr != VIR_UUID_BUFLEN;
}
static int
getDMISystemUUID(char *uuid, int len)
{
size_t i = 0;
const char *paths[] = {
"/sys/devices/virtual/dmi/id/product_uuid",
"/sys/class/dmi/id/product_uuid",
NULL
};
while (paths[i]) {
int fd = open(paths[i], O_RDONLY);
if (fd >= 0) {
if (saferead(fd, uuid, len - 1) == len - 1) {
uuid[len - 1] = '\0';
VIR_FORCE_CLOSE(fd);
return 0;
}
VIR_FORCE_CLOSE(fd);
}
i++;
}
return -1;
}
/**
* setHostUUID
*
* @host_uuid: UUID that the host is supposed to have
*
* Set the UUID of the host if it hasn't been set, yet
* Returns 0 in case of success, an error code in case of error.
*/
int
virSetHostUUIDStr(const char *uuid)
{
int rc;
char dmiuuid[VIR_UUID_STRING_BUFLEN];
if (virUUIDIsValid(host_uuid))
return EEXIST;
if (!uuid) {
memset(dmiuuid, 0, sizeof(dmiuuid));
if (!getDMISystemUUID(dmiuuid, sizeof(dmiuuid))) {
if (!virUUIDParse(dmiuuid, host_uuid))
return 0;
}
if (!virUUIDIsValid(host_uuid))
return virUUIDGenerate(host_uuid);
} else {
rc = virUUIDParse(uuid, host_uuid);
if (rc)
return rc;
if (!virUUIDIsValid(host_uuid))
return EINVAL;
}
return 0;
}
/**
* getHostUUID:
*
* @host_uuid: memory to store the host_uuid into
*
* Get the UUID of the host. Returns 0 in case of success,
* an error code otherwise.
* Returns 0 in case of success, an error code in case of error.
*/
int virGetHostUUID(unsigned char *uuid)
{
int ret = 0;
if (!virUUIDIsValid(host_uuid))
ret = virSetHostUUIDStr(NULL);
memcpy(uuid, host_uuid, sizeof(host_uuid));
return ret;
}