Re: [Qemu-devel] [PATCH v4 1/1] qga: Add 'guest-get-users' command

[Michael Roth]

Quoting Vinzenz 'evilissimo' Feenstra (2017-04-13 05:41:17)
> From: Vinzenz Feenstra <address@hidden>
> 
> 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 <address@hidden>
> ---
>  configure             |  2 +-
>  include/glib-compat.h |  5 +++
>  qga/commands-posix.c  | 52 ++++++++++++++++++++++++++++++
>  qga/commands-win32.c  | 89 
> +++++++++++++++++++++++++++++++++++++++++++++++++++
>  qga/qapi-schema.json  | 24 ++++++++++++++
>  5 files changed, 171 insertions(+), 1 deletion(-)
> 
> diff --git a/configure b/configure
> index be4d326..55e6654 100755
> --- a/configure
> +++ b/configure
> @@ -742,7 +742,7 @@ 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=""
> diff --git a/include/glib-compat.h b/include/glib-compat.h
> index 863c8cf..f8ee9dc 100644
> --- a/include/glib-compat.h
> +++ b/include/glib-compat.h
> @@ -217,6 +217,11 @@ static inline void g_hash_table_add(GHashTable 
> *hash_table, gpointer key)
>  {
>      g_hash_table_replace(hash_table, key, key);
>  }
> +
> +static 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
> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index 915df9e..4a59988 100644
> --- a/qga/commands-posix.c
> +++ b/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 +2518,54 @@ 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 = g_hash_table_new(g_str_hash, g_str_equal);
> +    GuestUserList *head = NULL, *cur_item = NULL;
> +    setutxent();
> +    for (;;) {
> +        struct utmpx *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)) {
> +            gpointer value = g_hash_table_lookup(cache, user_info->ut_user);
> +            GuestUser *user = (GuestUser *)value;
> +            double 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;
> +        }
> +
> +        GuestUserList *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;
> +}
> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> index 19d72b2..8b84a90 100644
> --- a/qga/commands-win32.c
> +++ b/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 +1540,88 @@ 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)
> +#ifndef QGA_NANOSECONDS
> +#   define QGA_NANOSECONDS 10000000
> +#endif

In my previous comment I was referring to all instances of this
#ifndef -> #define pattern. I think they are extraneous in this
case as well.

> +#ifndef QGA_EPOCH_TIME_DIFF
> +#   define QGA_EPOCH_TIME_DIFF 116444736000000000LL

We actually have a W32_FT_OFFSET currently used in
guest_get_time which you can probably use here as well.

> +#endif
> +
> +    GHashTable *cache = g_hash_table_new(g_str_hash, g_str_equal);
> +    GuestUserList *head = NULL, *cur_item = NULL;
> +
> +    DWORD count = 0;
> +    WTS_SESSION_INFOA *entries = NULL;
> +    if (WTSEnumerateSessionsA(NULL, 0, 1, &entries, &count)) {
> +        for (DWORD i = 0; i < count; ++i) {

The convention in QEMU seems to be to place all declarations at the
start of the block. There's a note about this in CODING_STYLE under
"5. Declarations".

> +            DWORD buffer_size = 0;
> +            GA_WTSINFOA *session_info = NULL;
> +            if (WTSQuerySessionInformationA(
> +                NULL,
> +                entries[i].SessionId,
> +                WTSSessionInfo,
> +                (LPSTR *)&session_info,
> +                &buffer_size
> +            )) {
> +                if (strlen(session_info->UserName) == 0 ||
> +                    g_hash_table_contains(cache, session_info->UserName)) {
> +                    WTSFreeMemory(session_info);
> +                    continue;

If it's already in the hash table, don't we want to update that entry with the
earliest login time here, like we did with the posix version?

> +                }
> +
> +                GuestUserList *item = g_new0(GuestUserList, 1);
> +                item->value = g_new0(GuestUser, 1);
> +
> +                item->value->user = g_strdup(session_info->UserName);
> +                item->value->domain = g_strdup(session_info->Domain);
> +                item->value->has_domain = true;
> +
> +                INT64 login = session_info->LogonTime.QuadPart;
> +                login -= QGA_EPOCH_TIME_DIFF;
> +                item->value->login_time = ((double)login) / QGA_NANOSECONDS;
> +
> +                g_hash_table_add(cache, item->value->user);
> +
> +                if (!cur_item) {
> +                    head = cur_item = item;
> +                } else {
> +                    cur_item->next = item;
> +                    cur_item = item;
> +                }
> +            }
> +            WTSFreeMemory(session_info);
> +        }
> +        WTSFreeMemory(entries);
> +    }
> +    g_hash_table_destroy(cache);
> +    return head;
> +#else
> +    error_setg(err, QERR_UNSUPPORTED);
> +    return NULL;
> +#endif
> +}
> diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
> index a02dbf2..27d10be 100644
> --- a/qga/qapi-schema.json
> +++ b/qga/qapi-schema.json
> @@ -1042,3 +1042,27 @@
>    'data':    { 'path': 'str', '*arg': ['str'], '*env': ['str'],
>                 '*input-data': 'str', '*capture-output': 'bool' },
>    'returns': 'GuestExec' }
> +
> +##
> +# @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'] }
> -- 
> 2.9.3
>