[Qemu-devel] [PATCH] Add guest-get-hostname to retrieve the guests current hostname

["Guido Günther" <agx@sigxcpu.org>]

This allows to retrieve the guest's hostname via gethostname(2).

This can be useful to identify a VM e.g. one without network.

Signed-off-by: Guido Günther <agx@sigxcpu.org>
---
We have an API in libvirt for that (virDomainGetHostname).
Cheers
 -- Guido

 qapi-schema-guest.json |   12 ++++++++++++
 qga/commands-posix.c   |   12 ++++++++++++
 qga/commands-win32.c   |    6 ++++++
 3 files changed, 30 insertions(+)

diff --git a/qapi-schema-guest.json b/qapi-schema-guest.json
index d955cf1..8c7a4a5 100644
--- a/qapi-schema-guest.json
+++ b/qapi-schema-guest.json
@@ -515,3 +515,15 @@
 ##
 { 'command': 'guest-network-get-interfaces',
   'returns': ['GuestNetworkInterface'] }
+
+##
+# @guest-get-hostname:
+#
+# Get the guest's hostname
+#
+# Returns: The guest's hostname
+#
+# Since: 1.2
+##
+{ 'command': 'guest-get-hostname',
+  'returns': 'str' }
diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index ce90421..9223f18 100644
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -15,6 +15,7 @@
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/wait.h>
+#include <unistd.h>
 #include "qga/guest-agent-core.h"
 #include "qga-qmp-commands.h"
 #include "qerror.h"
@@ -993,6 +994,17 @@ void qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **err)
 }
 #endif
 
+char *qmp_guest_get_hostname(Error **err)
+{
+    char hostname[HOST_NAME_MAX];
+
+    if (gethostname(hostname, HOST_NAME_MAX)) {
+        error_set(err, QERR_QGA_COMMAND_FAILED, strerror(errno));
+        return NULL;
+    }
+    return g_strdup(hostname);
+}
+
 /* register init/cleanup routines for stateful command groups */
 void ga_command_state_init(GAState *s, GACommandState *cs)
 {
diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index 54bc546..55e8162 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -280,6 +280,12 @@ GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **err)
     return NULL;
 }
 
+char *qmp_guest_get_hostname(Error **err)
+{
+    error_set(err, QERR_UNSUPPORTED);
+    return NULL;
+}
+
 /* register init/cleanup routines for stateful command groups */
 void ga_command_state_init(GAState *s, GACommandState *cs)
 {
-- 
1.7.10.4