Re: [PATCH v2 1/2] qga-win: add logging to Windows event log

[Marc-André Lureau]

Hi

On Tue, Nov 29, 2022 at 9:37 PM Andrey Drobyshev
<andrey.drobyshev@virtuozzo.com> wrote:
>
> This commit allows QGA to write to Windows event log using Win32 API's
> ReportEvent() [1], much like syslog() under *nix guests.
>
> In order to generate log message definitions we use a very basic message
> text file [2], so that every QGA's message gets ID 1.  The tools
> "windmc" and "windres" respectively are used to generate ".rc" file and
> COFF object file, and then the COFF file is linked into qemu-ga.exe.
>
> [1] 
> https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-reporteventa
> [2] 
> https://learn.microsoft.com/en-us/windows/win32/eventlog/message-text-files
>
> Originally-by: Yuri Pudgorodskiy <yur@virtuozzo.com>
> Signed-off-by: Andrey Drobyshev <andrey.drobyshev@virtuozzo.com>

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

> ---
>  configure                 |  3 +++
>  qga/installer/qemu-ga.wxs |  5 +++++
>  qga/main.c                | 16 +++++++++++++---
>  qga/meson.build           | 19 ++++++++++++++++++-
>  qga/messages-win32.mc     |  9 +++++++++
>  5 files changed, 48 insertions(+), 4 deletions(-)
>  create mode 100644 qga/messages-win32.mc
>
> diff --git a/configure b/configure
> index 26c7bc5154..789a4f6cc9 100755
> --- a/configure
> +++ b/configure
> @@ -372,6 +372,7 @@ smbd="$SMBD"
>  strip="${STRIP-${cross_prefix}strip}"
>  widl="${WIDL-${cross_prefix}widl}"
>  windres="${WINDRES-${cross_prefix}windres}"
> +windmc="${WINDMC-${cross_prefix}windmc}"
>  pkg_config_exe="${PKG_CONFIG-${cross_prefix}pkg-config}"
>  query_pkg_config() {
>      "${pkg_config_exe}" ${QEMU_PKG_CONFIG_FLAGS} "$@"
> @@ -2561,6 +2562,7 @@ if test "$skip_meson" = no; then
>    echo "strip = [$(meson_quote $strip)]" >> $cross
>    echo "widl = [$(meson_quote $widl)]" >> $cross
>    echo "windres = [$(meson_quote $windres)]" >> $cross
> +  echo "windmc = [$(meson_quote $windmc)]" >> $cross
>    if test "$cross_compile" = "yes"; then
>      cross_arg="--cross-file config-meson.cross"
>      echo "[host_machine]" >> $cross
> @@ -2667,6 +2669,7 @@ preserve_env SMBD
>  preserve_env STRIP
>  preserve_env WIDL
>  preserve_env WINDRES
> +preserve_env WINDMC
>
>  printf "exec" >>config.status
>  for i in "$0" "$@"; do
> diff --git a/qga/installer/qemu-ga.wxs b/qga/installer/qemu-ga.wxs
> index 73ce2c4965..d9567836f3 100644
> --- a/qga/installer/qemu-ga.wxs
> +++ b/qga/installer/qemu-ga.wxs
> @@ -110,6 +110,11 @@
>                <RegistryValue Type="string" Name="ProductID" 
> Value="fb0a0d66-c7fb-4e2e-a16b-c4a3bfe8d13b" />
>                <RegistryValue Type="string" Name="Version" 
> Value="$(var.QEMU_GA_VERSION)" />
>              </RegistryKey>
> +            <RegistryKey Root="HKLM"
> +                         
> Key="System\CurrentControlSet\Services\EventLog\Application\qemu-ga">
> +              <RegistryValue Type="integer" Name="TypesSupported" Value="7" 
> />
> +              <RegistryValue Type="string" Name="EventMessageFile" 
> Value="[qemu_ga_directory]qemu-ga.exe" />
> +            </RegistryKey>
>            </Component>
>          </Directory>
>        </Directory>
> diff --git a/qga/main.c b/qga/main.c
> index b3580508fa..e9f4f44cbb 100644
> --- a/qga/main.c
> +++ b/qga/main.c
> @@ -83,6 +83,7 @@ struct GAState {
>  #ifdef _WIN32
>      GAService service;
>      HANDLE wakeup_event;
> +    HANDLE event_log;
>  #endif
>      bool delimit_response;
>      bool frozen;
> @@ -324,13 +325,14 @@ static void ga_log(const gchar *domain, GLogLevelFlags 
> level,
>      }
>
>      level &= G_LOG_LEVEL_MASK;
> -#ifndef _WIN32
>      if (g_strcmp0(domain, "syslog") == 0) {
> +#ifndef _WIN32
>          syslog(LOG_INFO, "%s: %s", level_str, msg);
> -    } else if (level & s->log_level) {
>  #else
> -    if (level & s->log_level) {
> +        ReportEvent(s->event_log, EVENTLOG_INFORMATION_TYPE,
> +                    0, 1, NULL, 1, 0, &msg, NULL);
>  #endif
> +    } else if (level & s->log_level) {
>          g_autoptr(GDateTime) now = g_date_time_new_now_utc();
>          g_autofree char *nowstr = g_date_time_format(now, "%s.%f");
>          fprintf(s->log_file, "%s: %s: %s\n", nowstr, level_str, msg);
> @@ -1286,6 +1288,13 @@ static GAState *initialize_agent(GAConfig *config, int 
> socket_activation)
>      g_debug("Guest agent version %s started", QEMU_FULL_VERSION);
>
>  #ifdef _WIN32
> +    s->event_log = RegisterEventSource(NULL, "qemu-ga");
> +    if (!s->event_log) {
> +        g_autofree gchar *errmsg = g_win32_error_message(GetLastError());
> +        g_critical("unable to register event source: %s", errmsg);
> +        return NULL;
> +    }
> +
>      /* On win32 the state directory is application specific (be it the 
> default
>       * or a user override). We got past the command line parsing; let's 
> create
>       * the directory (with any intermediate directories). If we run into an
> @@ -1377,6 +1386,7 @@ static void cleanup_agent(GAState *s)
>  {
>  #ifdef _WIN32
>      CloseHandle(s->wakeup_event);
> +    CloseHandle(s->event_log);
>  #endif
>      if (s->command_state) {
>          ga_command_state_cleanup_all(s->command_state);
> diff --git a/qga/meson.build b/qga/meson.build
> index 3cfb9166e5..1ff159edc1 100644
> --- a/qga/meson.build
> +++ b/qga/meson.build
> @@ -98,7 +98,24 @@ if targetos == 'windows'
>    endif
>  endif
>
> -qga = executable('qemu-ga', qga_ss.sources(),
> +qga_objs = []
> +if targetos == 'windows'
> +  windmc = find_program('windmc', required: true)
> +  windres = find_program('windres', required: true)
> +
> +  msgrc = custom_target('messages-win32.rc',
> +                        input: 'messages-win32.mc',
> +                        output: ['messages-win32.rc', 'MSG00409.bin', 
> 'messages-win32.h'],
> +                        command: [windmc, '-h', '@OUTDIR@', '-r', 
> '@OUTDIR@', '@INPUT@'])
> +  msgobj = custom_target('messages-win32.o',
> +                         input: msgrc[0],
> +                         output: 'messages-win32.o',
> +                         command: [windres, '-I', '@OUTDIR@', '-o', 
> '@OUTPUT@', '@INPUT@'])
> +
> +  qga_objs = [msgobj]
> +endif
> +
> +qga = executable('qemu-ga', qga_ss.sources() + qga_objs,
>                   link_args: qga_libs,
>                   dependencies: [qemuutil, libudev],
>                   install: true)
> diff --git a/qga/messages-win32.mc b/qga/messages-win32.mc
> new file mode 100644
> index 0000000000..e21019cebe
> --- /dev/null
> +++ b/qga/messages-win32.mc
> @@ -0,0 +1,9 @@
> +LanguageNames=(
> +    English=0x409:MSG00409
> +)
> +
> +MessageId=1
> +SymbolicName=QEMU_GA_EVENTLOG_GENERAL
> +Language=English
> +%1
> +.
> --
> 2.38.1
>


-- 
Marc-André Lureau