qga: Add 'guest-get-users' command

A command that will list all currently logged in users, and the time
since when they are logged in.

Examples:

virsh # qemu-agent-command F25 '{ "execute": "guest-get-users" }'
{"return":[{"login-time":1490622289.903835,"user":"root"}]}

virsh # qemu-agent-command Win2k12r2 '{ "execute": "guest-get-users" }'
{"return":[{"login-time":1490351044.670552,"domain":"LADIDA",
"user":"Administrator"}]}

Signed-off-by: Vinzenz Feenstra <vfeenstr@redhat.com>
* make g_hash_table_contains compat func inline to avoid
  unused warnings
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

configure

@@ -743,7 +743,7 @@ if test "$mingw32" = "yes" ; then
   sysconfdir="\${prefix}"
   local_statedir=
   confsuffix=""
-  libs_qga="-lws2_32 -lwinmm -lpowrprof -liphlpapi -lnetapi32 $libs_qga"
+  libs_qga="-lws2_32 -lwinmm -lpowrprof -lwtsapi32 -liphlpapi -lnetapi32 $libs_qga"
 fi
 
 werror=""

include/glib-compat.h

@@ -217,6 +217,12 @@ static inline void g_hash_table_add(GHashTable *hash_table, gpointer key)
 {
     g_hash_table_replace(hash_table, key, key);
 }
+
+static inline gboolean g_hash_table_contains(GHashTable *hash_table,
+                                             gpointer key)
+{
+    return g_hash_table_lookup_extended(hash_table, key, NULL, NULL);
+}
 #endif
 
 #ifndef g_assert_true

qga/commands-posix.c

@@ -15,6 +15,7 @@
 #include <sys/ioctl.h>
 #include <sys/wait.h>
 #include <dirent.h>
+#include <utmpx.h>
 #include "qga/guest-agent-core.h"
 #include "qga-qmp-commands.h"
 #include "qapi/qmp/qerror.h"
@@ -2517,3 +2518,62 @@ void ga_command_state_init(GAState *s, GACommandState *cs)
     ga_command_state_add(cs, NULL, guest_fsfreeze_cleanup);
 #endif
 }
+
+#define QGA_MICRO_SECOND_TO_SECOND 1000000
+
+static double ga_get_login_time(struct utmpx *user_info)
+{
+    double seconds = (double)user_info->ut_tv.tv_sec;
+    double useconds = (double)user_info->ut_tv.tv_usec;
+    useconds /= QGA_MICRO_SECOND_TO_SECOND;
+    return seconds + useconds;
+}
+
+GuestUserList *qmp_guest_get_users(Error **err)
+{
+    GHashTable *cache = NULL;
+    GuestUserList *head = NULL, *cur_item = NULL;
+    struct utmpx *user_info = NULL;
+    gpointer value = NULL;
+    GuestUser *user = NULL;
+    GuestUserList *item = NULL;
+    double login_time = 0;
+
+    cache = g_hash_table_new(g_str_hash, g_str_equal);
+    setutxent();
+
+    for (;;) {
+        user_info = getutxent();
+        if (user_info == NULL) {
+            break;
+        } else if (user_info->ut_type != USER_PROCESS) {
+            continue;
+        } else if (g_hash_table_contains(cache, user_info->ut_user)) {
+            value = g_hash_table_lookup(cache, user_info->ut_user);
+            user = (GuestUser *)value;
+            login_time = ga_get_login_time(user_info);
+            /* We're ensuring the earliest login time to be sent */
+            if (login_time < user->login_time) {
+                user->login_time = login_time;
+            }
+            continue;
+        }
+
+        item = g_new0(GuestUserList, 1);
+        item->value = g_new0(GuestUser, 1);
+        item->value->user = g_strdup(user_info->ut_user);
+        item->value->login_time = ga_get_login_time(user_info);
+
+        g_hash_table_insert(cache, item->value->user, item->value);
+
+        if (!cur_item) {
+            head = cur_item = item;
+        } else {
+            cur_item->next = item;
+            cur_item = item;
+        }
+    }
+    endutxent();
+    g_hash_table_destroy(cache);
+    return head;
+}

qga/commands-win32.c

@@ -11,6 +11,9 @@
  * See the COPYING file in the top-level directory.
  */
 
+#ifndef _WIN32_WINNT
+#   define _WIN32_WINNT 0x0600
+#endif
 #include "qemu/osdep.h"
 #include <wtypes.h>
 #include <powrprof.h>
@@ -25,6 +28,7 @@
 #include <initguid.h>
 #endif
 #include <lm.h>
+#include <wtsapi32.h>
 
 #include "qga/guest-agent-core.h"
 #include "qga/vss-win32.h"
@@ -1536,3 +1540,102 @@ void ga_command_state_init(GAState *s, GACommandState *cs)
         ga_command_state_add(cs, NULL, guest_fsfreeze_cleanup);
     }
 }
+
+/* MINGW is missing two fields: IncomingFrames & OutgoingFrames */
+typedef struct _GA_WTSINFOA {
+    WTS_CONNECTSTATE_CLASS State;
+    DWORD SessionId;
+    DWORD IncomingBytes;
+    DWORD OutgoingBytes;
+    DWORD IncomingFrames;
+    DWORD OutgoingFrames;
+    DWORD IncomingCompressedBytes;
+    DWORD OutgoingCompressedBy;
+    CHAR WinStationName[WINSTATIONNAME_LENGTH];
+    CHAR Domain[DOMAIN_LENGTH];
+    CHAR UserName[USERNAME_LENGTH + 1];
+    LARGE_INTEGER ConnectTime;
+    LARGE_INTEGER DisconnectTime;
+    LARGE_INTEGER LastInputTime;
+    LARGE_INTEGER LogonTime;
+    LARGE_INTEGER CurrentTime;
+
+} GA_WTSINFOA;
+
+GuestUserList *qmp_guest_get_users(Error **err)
+{
+#if (_WIN32_WINNT >= 0x0600)
+#define QGA_NANOSECONDS 10000000
+
+    GHashTable *cache = NULL;
+    GuestUserList *head = NULL, *cur_item = NULL;
+
+    DWORD buffer_size = 0, count = 0, i = 0;
+    GA_WTSINFOA *info = NULL;
+    WTS_SESSION_INFOA *entries = NULL;
+    GuestUserList *item = NULL;
+    GuestUser *user = NULL;
+    gpointer value = NULL;
+    INT64 login = 0;
+    double login_time = 0;
+
+    cache = g_hash_table_new(g_str_hash, g_str_equal);
+
+    if (WTSEnumerateSessionsA(NULL, 0, 1, &entries, &count)) {
+        for (i = 0; i < count; ++i) {
+            buffer_size = 0;
+            info = NULL;
+            if (WTSQuerySessionInformationA(
+                NULL,
+                entries[i].SessionId,
+                WTSSessionInfo,
+                (LPSTR *)&info,
+                &buffer_size
+            )) {
+
+                if (strlen(info->UserName) == 0) {
+                    WTSFreeMemory(info);
+                    continue;
+                }
+
+                login = info->LogonTime.QuadPart;
+                login -= W32_FT_OFFSET;
+                login_time = ((double)login) / QGA_NANOSECONDS;
+
+                if (g_hash_table_contains(cache, info->UserName)) {
+                    value = g_hash_table_lookup(cache, info->UserName);
+                    user = (GuestUser *)value;
+                    if (user->login_time > login_time) {
+                        user->login_time = login_time;
+                    }
+                } else {
+                    item = g_new0(GuestUserList, 1);
+                    item->value = g_new0(GuestUser, 1);
+
+                    item->value->user = g_strdup(info->UserName);
+                    item->value->domain = g_strdup(info->Domain);
+                    item->value->has_domain = true;
+
+                    item->value->login_time = login_time;
+
+                    g_hash_table_add(cache, item->value->user);
+
+                    if (!cur_item) {
+                        head = cur_item = item;
+                    } else {
+                        cur_item->next = item;
+                        cur_item = item;
+                    }
+                }
+            }
+            WTSFreeMemory(info);
+        }
+        WTSFreeMemory(entries);
+    }
+    g_hash_table_destroy(cache);
+    return head;
+#else
+    error_setg(err, QERR_UNSUPPORTED);
+    return NULL;
+#endif
+}

qga/qapi-schema.json

@@ -1076,3 +1076,28 @@
 ##
 { 'command': 'guest-get-host-name',
   'returns': 'GuestHostName' }
+
+
+##
+# @GuestUser:
+# @user:       Username
+# @domain:     Logon domain (windows only)
+# @login-time: Time of login of this user on the computer. If multiple
+#              instances of the user are logged in, the earliest login time is
+#              reported. The value is in fractional seconds since epoch time.
+#
+# Since: 2.10
+##
+{ 'struct': 'GuestUser',
+  'data': { 'user': 'str', 'login-time': 'number', '*domain': 'str' } }
+
+##
+# @guest-get-users:
+# Retrieves a list of currently active users on the VM.
+#
+# Returns: A unique list of users.
+#
+# Since: 2.10
+##
+{ 'command': 'guest-get-users',
+  'returns': ['GuestUser'] }