vswitchd/xenserver.c

   1 /* Copyright (c) 2009, 2010, 2013 Nicira, Inc.
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #include <config.h>
  17 #include "xenserver.h"
  18 #include <ctype.h>
  19 #include <errno.h>
  20 #include <pthread.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include "openvswitch/dynamic-string.h"
  25 #include "process.h"
  26 #include "util.h"
  27 #include "openvswitch/vlog.h"
  28
  29 VLOG_DEFINE_THIS_MODULE(xenserver);
  30
  31 /* If running on a XenServer, the XenServer host UUID as a 36-character string,
  32  * otherwise null. */
  33 static char *host_uuid;
  34
  35 static void
  36 read_host_uuid(void)
  37 {
  38     static const char filename[] = "/etc/xensource-inventory";
  39     char line[128];
  40     FILE *file;
  41
  42     file = fopen(filename, "r");
  43     if (!file) {
  44         if (errno == ENOENT) {
  45             VLOG_DBG("not running on a XenServer");
  46         } else {
  47             VLOG_INFO("%s: open: %s", filename, ovs_strerror(errno));
  48         }
  49         return;
  50     }
  51
  52     while (fgets(line, sizeof line, file)) {
  53         static const char leader[] = "INSTALLATION_UUID='";
  54         const int leader_len = strlen(leader);
  55         const int uuid_len = 36;
  56         static const char trailer[] = "'\n";
  57         const int trailer_len = strlen(trailer);
  58
  59         if (strlen(line) == leader_len + uuid_len + trailer_len
  60             && !memcmp(line, leader, leader_len)
  61             && !memcmp(line + leader_len + uuid_len, trailer, trailer_len)) {
  62             host_uuid = xmemdup0(line + leader_len, uuid_len);
  63             VLOG_INFO("running on XenServer, host-uuid %s", host_uuid);
  64             fclose(file);
  65             return;
  66         }
  67     }
  68     fclose(file);
  69     VLOG_ERR("%s: INSTALLATION_UUID not found", filename);
  70 }
  71
  72 const char *
  73 xenserver_get_host_uuid(void)
  74 {
  75     static pthread_once_t once = PTHREAD_ONCE_INIT;
  76     pthread_once(&once, read_host_uuid);
  77     return host_uuid;
  78 }
  79