libvirt plugin: Fix the HostnameFormat option.

The attached patch fixes HostnameFormat in libvirt driver.

The intended use for this was:

   HostnameFormat "name"

generating hostnames like "<guestname>" (the default case), and:

   HostnameFormat "hostname name"

generating hostnames like "<hostname>:<guestname>".

Somewhere along the way, however, that code got broken so it always adds a ":"
before the name, and doesn't concatenate any more, so you'd get weird hostnames
appearing like ":guest" which was supposed to be "hostname:guest".

The patch just reverts back to my original code.

Rich.

diff --git a/src/libvirt.c b/src/libvirt.c
index 0a99822..a9fccb9 100644 (file)
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -643,7 +643,9 @@ ignore_device_match (ignorelist_t *il, const char *domname, const char *devpath)
 static void
 init_value_list (value_list_t *vl, time_t t, virDomainPtr dom)
 {
-    int i;
+    int i, n;
+    const char *name;
+    char uuid[VIR_UUID_STRING_BUFLEN];
     char  *host_ptr;
     size_t host_len;
 
@@ -659,51 +661,32 @@ init_value_list (value_list_t *vl, time_t t, virDomainPtr dom)
 
     /* Construct the hostname field according to HostnameFormat. */
     for (i = 0; i < HF_MAX_FIELDS; ++i) {
-       int status = 0;
+        if (hostname_format[i] == hf_none)
+            continue;
+
+        n = DATA_MAX_NAME_LEN - strlen (vl->host) - 2;
+
+        if (i > 0 && n >= 1) {
+            strcat (vl->host, ":");
+            n--;
+        }
 
         switch (hostname_format[i]) {
-           case hf_none:
-               /* do nothing */
-               break;
-
-           case hf_hostname:
-               status = snprintf (host_ptr, host_len, ":%s", hostname_g);
-               break;
-
-           case hf_name:
-           {
-               const char *name = virDomainGetName (dom);
-               if (name != NULL)
-                   status = snprintf (host_ptr, host_len, ":%s", name);
-               break;
-           }
-           case hf_uuid:
-           {
-               char uuid[VIR_UUID_STRING_BUFLEN];
-               if (virDomainGetUUIDString (dom, uuid) == 0) {
-                   uuid[sizeof (uuid) - 1] = '\0';
-                   status = snprintf (host_ptr, host_len, ":%s", uuid);
-               }
-               break;
-           }
-       } /* switch (hostname_format[i]) */
-
-       /* If status >= host_len
-        * => the buffer is full, there's no null-byte at the end and
-        *    continuing with this loop doesn't make any sense. */
-       if (status >= host_len) {
-           host_len = 0;
-           host_ptr = NULL;
-       }
-       /* else: Test if anything was added to the buffer */
-       else if (status > 0) {
-           host_len -= status;
-           host_ptr += status;
-       }
-
-       if (host_len <= 0)
-           break;
-    } /* for (i) */
+        case hf_none: break;
+        case hf_hostname:
+            strncat (vl->host, hostname_g, n);
+            break;
+        case hf_name:
+            name = virDomainGetName (dom);
+            if (name)
+                strncat (vl->host, name, n);
+            break;
+        case hf_uuid:
+            if (virDomainGetUUIDString (dom, uuid) == 0)
+                strncat (vl->host, uuid, n);
+            break;
+        }
+    }
 
     vl->host[sizeof (vl->host) - 1] = '\0';
 } /* void init_value_list */