Exemplo n.º 1
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)
{
    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;
}
Exemplo n.º 2
0
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;
}