[libvirt] [PATCH v2] Add host UUID (to libvirt capabilities)

This patch adds the host UUID (to the capabilities of libvirt). The user may provide it in libvirtd.conf overriding whatever sysfs may return. If none or no valid UUID is provided in libvirtd.conf, reading the UUID from sysfs is attempted. If that function doesn't provide a valid (not all digits may be equal), generate a temporary one. virSetHostUUIDStr() should be called first with the UUID read from libvirtd.conf, but may only be called once. Subsequently the functions virGetHostUUID[Str]() can be called to get the UUID of the host. Changes from V1 to V2: - addressing comments from Daniel Berrange: - rewrite/ code to get the UUID from 2 possible sysfs files - got rid of dmidecide dependency - call the newly added virGetHostUUID() function in udevGetDMIData() to get the UUID of the host ( even if it's just a temporary UUID ) Besides that, this patch - adds uuid to the capabilties XML schema - displays the UUID in in 'virsh capabilities' - adds 3 public functions to uuid.h for setting and getting the UUID of the host This patch contains recycled code from Scott Feldman (getDMISystemUUID()). Signed-off-by: Stefan Berger <stefanb(a)us.ibm.com&gt; --- daemon/libvirtd.c | 5 + src/conf/capabilities.c | 4 + src/util/uuid.c | 126 ++++++++++++++++++++++++++++++++++++++++++++++++ src/util/uuid.h | 4 + 4 files changed, 139 insertions(+) Index: libvirt-acl/daemon/libvirtd.c =================================================================== --- libvirt-acl.orig/daemon/libvirtd.c +++ libvirt-acl/daemon/libvirtd.c @@ -57,6 +57,7 @@ #include "dispatch.h" #include "util.h" +#include "uuid.h" #include "remote_driver.h" #include "conf.h" #include "event.h" @@ -2718,6 +2719,7 @@ remoteReadConfigFile (struct qemud_serve char *unix_sock_rw_perms = NULL; char *unix_sock_group = NULL; char *buf = NULL; + char *host_uuid = NULL; #if HAVE_POLKIT /* Change the default back to no auth for non-root */ @@ -2840,6 +2842,10 @@ remoteReadConfigFile (struct qemud_serve GET_CONF_INT (conf, filename, max_requests); GET_CONF_INT (conf, filename, max_client_requests); + GET_CONF_STR (conf, filename, host_uuid); + virSetHostUUIDStr(host_uuid); + VIR_FREE(host_uuid); + virConfFree (conf); return 0; Index: libvirt-acl/src/util/uuid.h =================================================================== --- libvirt-acl.orig/src/util/uuid.h +++ libvirt-acl/src/util/uuid.h @@ -22,6 +22,10 @@ #ifndef __VIR_UUID_H__ # define __VIR_UUID_H__ +int virSetHostUUIDStr(const char *host_uuid); +int virGetHostUUID(unsigned char *host_uuid); +int virGetHostUUIDStr(char *host_uuid); + int virUUIDGenerate(unsigned char *uuid); int virUUIDParse(const char *uuidstr, Index: libvirt-acl/src/util/uuid.c =================================================================== --- libvirt-acl.orig/src/util/uuid.c +++ libvirt-acl/src/util/uuid.c @@ -38,11 +38,14 @@ #include "util.h" #include "virterror_internal.h" #include "logging.h" +#include "memory.h" #ifndef ENODATA # define ENODATA EIO #endif +static unsigned char host_uuid[VIR_UUID_BUFLEN]; + static int virUUIDGenerateRandomBytes(unsigned char *buf, int buflen) @@ -208,3 +211,134 @@ void virUUIDFormat(const unsigned char * uuid[12], uuid[13], uuid[14], uuid[15]); uuidstr[VIR_UUID_STRING_BUFLEN-1] = '\0'; } + + + +/** + * isValidHostUUID + * + * @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 + */ +static int +isValidHostUUID(unsigned char *uuid) +{ + unsigned int i, 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) +{ + unsigned int 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) == len) { + close(fd); + return 0; + } + 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) +{ + char dmiuuid[VIR_UUID_STRING_BUFLEN]; + + if (isValidHostUUID(host_uuid)) + return EEXIST; + + if (!uuid) { + if (!getDMISystemUUID(dmiuuid, sizeof(dmiuuid))) { + if (!virUUIDParse(dmiuuid, host_uuid)) { + return 0; + } + } + } else { + if (!virUUIDParse(uuid, host_uuid)) + return 0; + } + + if (!isValidHostUUID(host_uuid)) + return virUUIDGenerate(host_uuid); + 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 (!isValidHostUUID(host_uuid)) + ret = virSetHostUUIDStr(NULL); + + memcpy(uuid, host_uuid, sizeof(host_uuid)); + + return ret; +} + + +/** + * 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 virGetHostUUIDStr(char *uuid) +{ + int ret = 0; + + if (!isValidHostUUID(host_uuid)) + ret = virSetHostUUIDStr(NULL); + + virUUIDFormat(host_uuid, uuid); + + return ret; +} Index: libvirt-acl/src/conf/capabilities.c =================================================================== --- libvirt-acl.orig/src/conf/capabilities.c +++ libvirt-acl/src/conf/capabilities.c @@ -27,6 +27,7 @@ #include "buf.h" #include "memory.h" #include "util.h" +#include "uuid.h" #include "cpu_conf.h" /** @@ -662,9 +663,12 @@ virCapabilitiesFormatXML(virCapsPtr caps { virBuffer xml = VIR_BUFFER_INITIALIZER; int i, j, k; + char host_uuid[VIR_UUID_STRING_BUFLEN]; + virGetHostUUIDStr(host_uuid); virBufferAddLit(&xml, "<capabilities>\n\n"); virBufferAddLit(&xml, " <host>\n"); + virBufferVSprintf(&xml," <uuid>%s</uuid>\n", host_uuid); virBufferAddLit(&xml, " <cpu>\n"); virBufferVSprintf(&xml, " <arch>%s</arch>\n", caps->host.arch); Index: libvirt-acl/docs/schemas/capability.rng =================================================================== --- libvirt-acl.orig/docs/schemas/capability.rng +++ libvirt-acl/docs/schemas/capability.rng @@ -18,6 +18,9 @@ <define name='hostcaps'> <element name='host'> + <element name='uuid'> + <ref name='UUID'/> + </element> <element name='cpu'> <element name='arch'> <ref name='archnames'/> @@ -349,4 +352,15 @@ <param name='pattern'>[a-zA-Z0-9\-_]+</param> </data> </define> + + <define name="UUID"> + <choice> + <data type="string"> + <param name="pattern">[a-fA-F0-9]{32}</param> + </data> + <data type="string"> + <param name="pattern">[a-fA-F0-9]{8}\-([a-fA-F0-9]{4}\-){3}[a-fA-F0-9]{12}</param> + </data> + </choice> + </define> </grammar> Index: libvirt-acl/src/libvirt_private.syms =================================================================== --- libvirt-acl.orig/src/libvirt_private.syms +++ libvirt-acl/src/libvirt_private.syms @@ -708,6 +708,9 @@ usbDeviceFileIterate; virUUIDFormat; virUUIDGenerate; virUUIDParse; +virSetHostUUIDStr; +virGetHostUUID; +virGetHostUUIDStr; # virterror_internal.h Index: libvirt-acl/daemon/libvirtd.conf =================================================================== --- libvirt-acl.orig/daemon/libvirtd.conf +++ libvirt-acl/daemon/libvirtd.conf @@ -312,3 +312,12 @@ # e.g.: # log_outputs="3:syslog:libvirtd" # to log all warnings and errors to syslog under the libvirtd ident + +# UUID of the host: +# Provide the UUID of the host here in case the command +# 'dmidecode -s system-uuid' does not provide a valid uuid. In case +# 'dmidecode' does not provide a valid UUID and none is provided here, a +# temporary UUID will be generated. +# Keep the format of the example UUID below. + +#host_uuid = '8510b1a1-1afa-4da6-8111-785fae202c1d' Index: libvirt-acl/src/node_device/node_device_udev.c =================================================================== --- libvirt-acl.orig/src/node_device/node_device_udev.c +++ libvirt-acl/src/node_device/node_device_udev.c @@ -1473,12 +1473,8 @@ udevGetDMIData(union _virNodeDevCapData goto out; } - if (udevGetStringSysfsAttr(device, - "product_uuid", - &tmp) == PROPERTY_ERROR) { + if (virGetHostUUID(data->system.hardware.uuid)) goto out; - } - virUUIDParse(tmp, data->system.hardware.uuid); if (udevGetStringSysfsAttr(device, "bios_vendor",