Implement getVersion API for openvz driver

ChangeLog

@@ -1,3 +1,9 @@
+Fri Oct 24 12:32:23 BST Daniel P. Berrange <berrange@redhat.com>
+
+	* src/openvz_conf.c, src/openvz_conf.h: Extract version
+	info from vzctl tool
+	* src/openvz_driver.c: Implement the getVersion API call.
+
 Fri Oct 24 12:30:23 BST Daniel P. Berrange <berrange@redhat.com>
 
 	Fix mingw build

src/openvz_conf.c

@@ -41,6 +41,7 @@
 #include <errno.h>
 #include <string.h>
 #include <sys/utsname.h>
+#include <sys/wait.h>
 
 #include "openvz_conf.h"
 #include "uuid.h"
@@ -64,6 +65,73 @@ strtoI(const char *str)
     return val;
 }
 
+
+static int
+openvzExtractVersionInfo(const char *cmd, int *retversion)
+{
+    const char *const vzarg[] = { cmd, "--help", NULL };
+    const char *const vzenv[] = { "LC_ALL=C", NULL };
+    pid_t child;
+    int newstdout = -1;
+    int ret = -1, status;
+    unsigned int major, minor, micro;
+    unsigned int version;
+
+    if (retversion)
+        *retversion = 0;
+
+    if (virExec(NULL, vzarg, vzenv, NULL,
+                &child, -1, &newstdout, NULL, VIR_EXEC_NONE) < 0)
+        return -1;
+
+    char *help = NULL;
+    int len = virFileReadLimFD(newstdout, 512, &help);
+    if (len < 0)
+        goto cleanup2;
+
+    if (sscanf(help, "vzctl version %u.%u.%u",
+               &major, &minor, &micro) != 3) {
+        goto cleanup2;
+    }
+
+    version = (major * 1000 * 1000) + (minor * 1000) + micro;
+
+    if (retversion)
+        *retversion = version;
+
+    ret = 0;
+
+cleanup2:
+    VIR_FREE(help);
+    if (close(newstdout) < 0)
+        ret = -1;
+
+rewait:
+    if (waitpid(child, &status, 0) != child) {
+        if (errno == EINTR)
+            goto rewait;
+        ret = -1;
+    }
+
+    return ret;
+}
+
+int openvzExtractVersion(virConnectPtr conn,
+                         struct openvz_driver *driver)
+{
+    if (driver->version > 0)
+        return 0;
+
+    if (openvzExtractVersionInfo(VZCTL, &driver->version) < 0) {
+        openvzError(conn, VIR_ERR_INTERNAL_ERROR,
+                    "%s", _("Cound not extract vzctl version"));
+        return -1;
+    }
+
+    return 0;
+}
+
+
 virCapsPtr openvzCapsInit(void)
 {
     struct utsname utsname;

src/openvz_conf.h

@@ -47,15 +47,18 @@ enum { OPENVZ_WARN, OPENVZ_ERR };
 
 
 /* OpenVZ commands - Replace with wrapper scripts later? */
-#define VZLIST  "vzlist"
+#define VZLIST  "/usr/sbin/vzlist"
-#define VZCTL   "vzctl"
+#define VZCTL   "/usr/sbin/vzctl"
 
 struct openvz_driver {
     virCapsPtr caps;
     virDomainObjList domains;
+    int version;
 };
 
 int openvz_readline(int fd, char *ptr, int maxlen);
+int openvzExtractVersion(virConnectPtr conn,
+                         struct openvz_driver *driver);
 int openvzReadConfigParam(int vpsid ,const char * param, char *value, int maxlen);
 virCapsPtr openvzCapsInit(void);
 int openvzLoadDomains(struct openvz_driver *driver);

src/openvz_driver.c

@@ -172,6 +172,12 @@ static virDomainPtr openvzDomainLookupByID(virConnectPtr conn,
     return dom;
 }
 
+static int openvzGetVersion(virConnectPtr conn, unsigned long *version) {
+    struct  openvz_driver *driver = (struct openvz_driver *)conn->privateData;
+    *version = driver->version;
+    return 0;
+}
+
 static char *openvzGetOSType(virDomainPtr dom)
 {
     struct  openvz_driver *driver = (struct openvz_driver *)dom->conn->privateData;
@@ -777,6 +783,9 @@ static virDrvOpenStatus openvzOpen(virConnectPtr conn,
     if (openvzLoadDomains(driver) < 0)
         goto cleanup;
 
+    if (openvzExtractVersion(conn, driver) < 0)
+        goto cleanup;
+
     conn->privateData = driver;
 
     return VIR_DRV_OPEN_SUCCESS;
@@ -961,7 +970,7 @@ static virDriver openvzDriver = {
     openvzClose, /* close */
     NULL, /* supports_feature */
     openvzGetType, /* type */
-    NULL, /* version */
+    openvzGetVersion, /* version */
     NULL, /* hostname */
     NULL, /* uri */
     openvzGetMaxVCPUs, /* getMaxVcpus */