Re: [libvirt] [PATCH] daemon: add option to read host uuid from /etc/machine-id

Daemon config parameter switch between reading host uuid either from smbios or machine-id: host_uuid_source = "smbios|machine-id" Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy(a)virtuozzo.com&gt; --- daemon/libvirtd-config.c | 2 ++ daemon/libvirtd-config.h | 1 + daemon/libvirtd.c | 38 +++++++++++++++++++++++++++++++++++--- daemon/libvirtd.conf | 14 ++++++++++---- src/libvirt_private.syms | 1 + src/util/viruuid.c | 31 ++++++++++++++++++++++--------- src/util/viruuid.h | 3 +++ 7 files changed, 74 insertions(+), 16 deletions(-) diff --git a/daemon/libvirtd-config.c b/daemon/libvirtd-config.c index 7a448f9..45280e9 100644 --- a/daemon/libvirtd-config.c +++ b/daemon/libvirtd-config.c @@ -374,6 +374,7 @@ daemonConfigFree(struct daemonConfig *data) VIR_FREE(data->crl_file); VIR_FREE(data->host_uuid); + VIR_FREE(data->host_uuid_source); VIR_FREE(data->log_filters); VIR_FREE(data->log_outputs); @@ -463,6 +464,7 @@ daemonConfigLoadOptions(struct daemonConfig *data, GET_CONF_UINT(conf, filename, audit_logging); GET_CONF_STR(conf, filename, host_uuid); + GET_CONF_STR(conf, filename, host_uuid_source); GET_CONF_UINT(conf, filename, log_level); GET_CONF_STR(conf, filename, log_filters); diff --git a/daemon/libvirtd-config.h b/daemon/libvirtd-config.h index 3e1971d..672e9ad 100644 --- a/daemon/libvirtd-config.h +++ b/daemon/libvirtd-config.h @@ -28,6 +28,7 @@ struct daemonConfig { char *host_uuid; + char *host_uuid_source; int listen_tls; int listen_tcp; diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c index 7ec02ad..ca1ec7a 100644 --- a/daemon/libvirtd.c +++ b/daemon/libvirtd.c @@ -1076,6 +1076,39 @@ static int migrateProfile(void) return ret; } +static int +daemonSetupHostUUID(const struct daemonConfig *config) +{ + static const char *machine_id = "/etc/machine-id"; + char buf[VIR_UUID_STRING_BUFLEN]; + const char *uuid; + + if (config->host_uuid) { + uuid = config->host_uuid; + } else if (!config->host_uuid_source || + STREQ(config->host_uuid_source, "smbios")) { + /* set host uuid in lazy manner*/

+ return 0; + } else if (STREQ(config->host_uuid_source, "machine-id")) { + if (virUUIDRead(machine_id, buf, sizeof(buf)) < 0) { + VIR_ERROR(_("Can't read %s"), machine_id); + return -1; + } + + uuid = buf; + } else { + VIR_ERROR(_("invalid UUID source: %s"), config->host_uuid_source); + return -1; + } + + if (virSetHostUUIDStr(uuid)) { + VIR_ERROR(_("invalid host UUID: %s"), uuid); + return -1; + } + + return 0; +} + /* Print command-line usage. */ static void daemonUsage(const char *argv0, bool privileged) @@ -1295,9 +1328,8 @@ int main(int argc, char **argv) { exit(EXIT_FAILURE); } - if (config->host_uuid && - virSetHostUUIDStr(config->host_uuid) < 0) { - VIR_ERROR(_("invalid host UUID: %s"), config->host_uuid); + if (daemonSetupHostUUID(config) < 0) { + VIR_ERROR(_("Can't setup host uuid")); exit(EXIT_FAILURE); } diff --git a/daemon/libvirtd.conf b/daemon/libvirtd.conf index d2c439c..eaae680 100644 --- a/daemon/libvirtd.conf +++ b/daemon/libvirtd.conf @@ -410,10 +410,15 @@ ################################################################### # 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. +# host uuid is read from one of host uuid sources specified +# in host_uuid_source. Possible values are 'smbios' and 'machine-id'. +# First option will set host uuid from 'dmidecode -s system-uuid', +# while second will read it from /etc/machine-id. uuid source +# defaults to smbios. Other option is to specify host uuid +# right here in host_uuid option, in this case host_uuid_source +# will not be taken into account. In case uuid value in +# smbios is invalid temporary host uuid will be generated. +#

# Keep the format of the example UUID below. UUID must not have all digits # be the same. @@ -421,6 +426,7 @@ # it with the output of the 'uuidgen' command and then # uncomment this entry #host_uuid = "00000000-0000-0000-0000-000000000000" +#host_uuid_source = "smbios" ################################################################### # Keepalive protocol: diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 2b55369..e5823b2 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -2512,6 +2512,7 @@ virUUIDFormat; virUUIDGenerate; virUUIDIsValid; virUUIDParse; +virUUIDRead; # util/virxml.h diff --git a/src/util/viruuid.c b/src/util/viruuid.c index 16e57db..721eac0 100644 --- a/src/util/viruuid.c +++ b/src/util/viruuid.c @@ -231,21 +231,34 @@ getDMISystemUUID(char *uuid, int len) }; 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); - } + if (virUUIDRead(paths[i], uuid, len) == 0) + return 0; i++; } return -1; } +int +virUUIDRead(const char *file, char *uuid, int len) +{ + int fd; + ssize_t sz; + + fd = open(file, O_RDONLY); + if (fd < 0) + return -1; + + if ((sz = saferead(fd, uuid, len - 1)) < 0) + goto cleanup; + + uuid[sz] = '\0'; + + cleanup: + VIR_FORCE_CLOSE(fd); + return sz < 0 ? -1 : 0; +} +