Introduce new API for generating random numbers

The old virRandom() API was not generating good random numbers.
Replace it with a new API virRandomBits which instead of being
told the upper limit, gets told the number of bits of randomness
required.

* src/util/virrandom.c, src/util/virrandom.h: Add virRandomBits,
  and move virRandomInitialize
* src/util/util.h, src/util/util.c: Delete virRandom and
  virRandomInitialize
* src/libvirt.c, src/security/security_selinux.c,
  src/test/test_driver.c, src/util/iohelper.c: Update for
  changes from virRandom to virRandomBits
* src/storage/storage_backend_iscsi.c: Remove bogus call
  to virRandomInitialize & convert to virRandomBits
This commit is contained in:
Daniel P. Berrange 2012-01-25 15:17:46 +00:00
parent 8a09ee4103
commit e95ef67b35
13 changed files with 135 additions and 53 deletions

View File

@ -99,6 +99,7 @@ UTIL_SOURCES = \
util/virnetdevtap.h util/virnetdevtap.c \
util/virnetdevveth.h util/virnetdevveth.c \
util/virnetdevvportprofile.h util/virnetdevvportprofile.c \
util/virrandom.h util/virrandom.c \
util/virsocketaddr.h util/virsocketaddr.c \
util/virtime.h util/virtime.c

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@ -36,7 +36,6 @@
#include "driver.h"
#include "uuid.h"
#include "util.h"
#include "memory.h"
#include "configmake.h"
#include "intprops.h"
@ -44,6 +43,7 @@
#include "rpc/virnettlscontext.h"
#include "command.h"
#include "virnodesuspend.h"
#include "virrandom.h"
#ifndef WITH_DRIVER_MODULES
# ifdef WITH_TEST

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@ -1126,8 +1126,6 @@ virParseMacAddr;
virParseNumber;
virParseVersionString;
virPipeReadUntilEOF;
virRandom;
virRandomInitialize;
virSetBlocking;
virSetCloseExec;
virSetInherit;
@ -1369,6 +1367,11 @@ virPidFileDelete;
virPidFileDeletePath;
# virrandom.h
virRandomBits;
virRandomInitialize;
# virsocketaddr.h
virSocketAddrBroadcast;
virSocketAddrBroadcastByPrefix;

View File

@ -32,6 +32,7 @@
#include "hostusb.h"
#include "storage_file.h"
#include "virfile.h"
#include "virrandom.h"
#define VIR_FROM_THIS VIR_FROM_SECURITY
@ -216,8 +217,8 @@ SELinuxGenSecurityLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED,
}
} else {
do {
c1 = virRandom(1024);
c2 = virRandom(1024);
c1 = virRandomBits(10);
c2 = virRandomBits(10);
if ( c1 == c2 ) {
if (virAsprintf(&mcs, "s0:c%d", c1) < 0) {

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@ -42,6 +42,7 @@
#include "logging.h"
#include "virfile.h"
#include "command.h"
#include "virrandom.h"
#define VIR_FROM_THIS VIR_FROM_STORAGE
@ -283,15 +284,8 @@ virStorageBackendCreateIfaceIQN(const char *initiatoriqn,
initiatoriqn, NULL
};
if (virRandomInitialize(time(NULL) ^ getpid()) == -1) {
virStorageReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Failed to initialize random generator "
"when creating iscsi interface"));
goto out;
}
snprintf(temp_ifacename, sizeof(temp_ifacename), "libvirt-iface-%08x",
virRandom(1024 * 1024 * 1024));
snprintf(temp_ifacename, sizeof(temp_ifacename), "libvirt-iface-%08llx",
(unsigned long long)virRandomBits(30));
VIR_DEBUG("Attempting to create interface '%s' with IQN '%s'",
&temp_ifacename[0], initiatoriqn);

View File

@ -51,6 +51,7 @@
#include "logging.h"
#include "virfile.h"
#include "virtypedparam.h"
#include "virrandom.h"
#define VIR_FROM_THIS VIR_FROM_TEST
@ -5316,7 +5317,7 @@ testNodeDeviceCreateXML(virConnectPtr conn,
if (caps->type != VIR_NODE_DEV_CAP_SCSI_HOST)
continue;
caps->data.scsi_host.host = virRandom(1024);
caps->data.scsi_host.host = virRandomBits(10);
caps = caps->next;
}

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@ -39,6 +39,7 @@
#include "memory.h"
#include "virterror_internal.h"
#include "configmake.h"
#include "virrandom.h"
#define VIR_FROM_THIS VIR_FROM_STORAGE

View File

@ -77,6 +77,7 @@
#include "command.h"
#include "nonblocking.h"
#include "passfd.h"
#include "virrandom.h"
#ifndef NSIG
# define NSIG 32
@ -1853,9 +1854,9 @@ void virGenerateMacAddr(const unsigned char *prefix,
addr[0] = prefix[0];
addr[1] = prefix[1];
addr[2] = prefix[2];
addr[3] = virRandom(256);
addr[4] = virRandom(256);
addr[5] = virRandom(256);
addr[3] = virRandomBits(8);
addr[4] = virRandomBits(8);
addr[5] = virRandomBits(8);
}
@ -2097,36 +2098,6 @@ int virKillProcess(pid_t pid, int sig)
}
static char randomState[128];
static struct random_data randomData;
static virMutex randomLock;
int virRandomInitialize(unsigned int seed)
{
if (virMutexInit(&randomLock) < 0)
return -1;
if (initstate_r(seed,
randomState,
sizeof(randomState),
&randomData) < 0)
return -1;
return 0;
}
int virRandom(int max)
{
int32_t ret;
virMutexLock(&randomLock);
random_r(&randomData, &ret);
virMutexUnlock(&randomLock);
return (int) ((double)max * ((double)ret / (double)RAND_MAX));
}
#ifdef HAVE_GETPWUID_R
enum {
VIR_USER_ENT_DIRECTORY,

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@ -242,9 +242,6 @@ int virGetUserID(const char *name,
int virGetGroupID(const char *name,
gid_t *gid) ATTRIBUTE_RETURN_CHECK;
int virRandomInitialize(unsigned int seed) ATTRIBUTE_RETURN_CHECK;
int virRandom(int max);
char *virFileFindMountPoint(const char *type);
void virFileWaitForDevices(void);

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@ -40,6 +40,7 @@
#include "logging.h"
#include "memory.h"
#include "virfile.h"
#include "virrandom.h"
#ifndef ENODATA
# define ENODATA EIO
@ -80,7 +81,7 @@ virUUIDGeneratePseudoRandomBytes(unsigned char *buf,
int buflen)
{
while (buflen > 0) {
*buf++ = virRandom(256);
*buf++ = virRandomBits(8);
buflen--;
}

81
src/util/virrandom.c Normal file
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@ -0,0 +1,81 @@
/*
* Copyright (C) 2012 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Authors:
* Daniel P. Berrange <berrange@redhat.com>
*/
#include <config.h>
#include <stdlib.h>
#include "virrandom.h"
#include "threads.h"
#include "count-one-bits.h"
static char randomState[128];
static struct random_data randomData;
static virMutex randomLock;
int virRandomInitialize(uint32_t seed)
{
if (virMutexInit(&randomLock) < 0)
return -1;
if (initstate_r(seed,
randomState,
sizeof(randomState),
&randomData) < 0)
return -1;
return 0;
}
/*
* virRandomBits:
* @nbits: Number of bits of randommess required
*
* Generate an evenly distributed random number between [0,2^nbits), where
* @nbits must be in the range (0,64].
*
* Return: a random number with @nbits entropy
*/
uint64_t virRandomBits(int nbits)
{
int bits_per_iter = count_one_bits(RAND_MAX);
uint64_t ret = 0;
int32_t bits;
/* This algorithm requires that RAND_MAX == 2^n-1 for some n;
gnulib's random_r meets this property. */
verify(((RAND_MAX + 1U) & RAND_MAX) == 0);
virMutexLock(&randomLock);
while (nbits > bits_per_iter) {
random_r(&randomData, &bits);
ret = (ret << bits_per_iter) | (bits & RAND_MAX);
nbits -= bits_per_iter;
}
random_r(&randomData, &bits);
ret = (ret << nbits) | (bits & ((1 << nbits) - 1));
virMutexUnlock(&randomLock);
return ret;
}

30
src/util/virrandom.h Normal file
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@ -0,0 +1,30 @@
/*
* Copyright (C) 2012 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Authors:
* Daniel P. Berrange <berrange@redhat.com>
*/
#ifndef __VIR_RANDOM_H__
# define __VIR_RANDOM_H__
# include "internal.h"
int virRandomInitialize(uint32_t seed) ATTRIBUTE_RETURN_CHECK;
uint64_t virRandomBits(int nbits);
#endif /* __VIR_RANDOM_H__ */

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@ -1,7 +1,7 @@
/*
* testutils.c: basic test utils
*
* Copyright (C) 2005-2011 Red Hat, Inc.
* Copyright (C) 2005-2012 Red Hat, Inc.
*
* See COPYING.LIB for the License of this software
*
@ -34,6 +34,7 @@
#include "buf.h"
#include "logging.h"
#include "command.h"
#include "virrandom.h"
#if TEST_OOM_TRACE
# include <execinfo.h>