tools/hv: Parse /etc/os-release

There is a new convention, used by systemd and supported by most
distributions, to put basic OS release information in /etc/os-release.
Added some additional error checking on strdup()

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 55 insertions, 4 deletions

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index 3922abc0daef..5959affd8820 100644
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -454,6 +454,7 @@ void kvp_get_os_info(void)
 
         uname(&uts_buf);
         os_build = uts_buf.release;
+        os_name = uts_buf.sysname;
         processor_arch = uts_buf.machine;
 
         /*
@@ -465,20 +466,70 @@ void kvp_get_os_info(void)
         if (p)
                 *p = '\0';
 
+        /*
+         * Parse the /etc/os-release file if present:
+         * http://www.freedesktop.org/software/systemd/man/os-release.html
+         */
+        file = fopen("/etc/os-release", "r");
+        if (file != NULL) {
+                while (fgets(buf, sizeof(buf), file)) {
+                        char *value, *q;
+
+                        /* Ignore comments */
+                        if (buf[0] == '#')
+                                continue;
+
+                        /* Split into name=value */
+                        p = strchr(buf, '=');
+                        if (!p)
+                                continue;
+                        *p++ = 0;
+
+                        /* Remove quotes and newline; un-escape */
+                        value = p;
+                        q = p;
+                        while (*p) {
+                                if (*p == '\\') {
+                                        ++p;
+                                        if (!*p)
+                                                break;
+                                        *q++ = *p++;
+                                } else if (*p == '\'' || *p == '"' ||
+                                           *p == '\n') {
+                                        ++p;
+                                } else {
+                                        *q++ = *p++;
+                                }
+                        }
+                        *q = 0;
+
+                        if (!strcmp(buf, "NAME")) {
+                                p = strdup(value);
+                                if (!p)
+                                        break;
+                                os_name = p;
+                        } else if (!strcmp(buf, "VERSION_ID")) {
+                                p = strdup(value);
+                                if (!p)
+                                        break;
+                                os_major = p;
+                        }
+                }
+                fclose(file);
+                return;
+        }
+
+        /* Fallback for older RH/SUSE releases */
         file = fopen("/etc/SuSE-release", "r");
         if (file != NULL)
                 goto kvp_osinfo_found;
         file  = fopen("/etc/redhat-release", "r");
         if (file != NULL)
                 goto kvp_osinfo_found;
-        /*
-         * Add code for other supported platforms.
-         */
 
         /*
          * We don't have information about the os.
          */
-        os_name = uts_buf.sysname;
         return;
 
 kvp_osinfo_found: