/**
* 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)
{
uint64_t ret = 0;
int32_t bits;
if (virRandomInitialize() < 0) {
/* You're already hosed, so this particular non-random value
* isn't any worse. */
VIR_WARN("random number generation is broken");
return 0;
}
virMutexLock(&randomLock);
while (nbits > RANDOM_BITS_PER_ITER) {
random_r(&randomData, &bits);
ret = (ret << RANDOM_BITS_PER_ITER) | (bits & RANDOM_BITS_MASK);
nbits -= RANDOM_BITS_PER_ITER;
}
random_r(&randomData, &bits);
ret = (ret << nbits) | (bits & ((1 << nbits) - 1));
virMutexUnlock(&randomLock);
return ret;
}
static int
virStorageBackendCreateIfaceIQN(const char *initiatoriqn,
char **ifacename)
{
int ret = -1, exitstatus = -1;
char temp_ifacename[32];
const char *const cmdargv1[] = {
ISCSIADM, "--mode", "iface", "--interface",
temp_ifacename, "--op", "new", NULL
};
const char *const cmdargv2[] = {
ISCSIADM, "--mode", "iface", "--interface", temp_ifacename,
"--op", "update", "--name", "iface.initiatorname", "--value",
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));
VIR_DEBUG("Attempting to create interface '%s' with IQN '%s'",
&temp_ifacename[0], initiatoriqn);
/* Note that we ignore the exitstatus. Older versions of iscsiadm
* tools returned an exit status of > 0, even if they succeeded.
* We will just rely on whether the interface got created
* properly. */
if (virRun(cmdargv1, &exitstatus) < 0) {
virStorageReportError(VIR_ERR_INTERNAL_ERROR,
_("Failed to run command '%s' to create new iscsi interface"),
cmdargv1[0]);
goto out;
}
/* Note that we ignore the exitstatus. Older versions of iscsiadm tools
* returned an exit status of > 0, even if they succeeded. We will just
* rely on whether iface file got updated properly. */
if (virRun(cmdargv2, &exitstatus) < 0) {
virStorageReportError(VIR_ERR_INTERNAL_ERROR,
_("Failed to run command '%s' to update iscsi interface with IQN '%s'"),
cmdargv2[0], initiatoriqn);
goto out;
}
/* Check again to make sure the interface was created. */
if (virStorageBackendIQNFound(initiatoriqn, ifacename) != IQN_FOUND) {
VIR_DEBUG("Failed to find interface '%s' with IQN '%s' "
"after attempting to create it",
&temp_ifacename[0], initiatoriqn);
goto out;
} else {
VIR_DEBUG("Interface '%s' with IQN '%s' was created successfully",
*ifacename, initiatoriqn);
}
ret = 0;
out:
if (ret != 0)
VIR_FREE(*ifacename);
return ret;
}