[virt-tools-list] [PATCH v2 1/3] remote-viewer: learn '-' as URI for standard input connection file

Marc-André Lureau marcandre.lureau at redhat.com
Tue Nov 14 16:39:54 UTC 2017


Hi

----- Original Message -----
> Hi,
> 
> On Tue, Nov 14, 2017 at 04:56:01PM +0100, marcandre.lureau at redhat.com wrote:
> > From: Marc-André Lureau <marcandre.lureau at redhat.com>
> > 
> > Some users want the ability to set connection details without writing
> > to a file or passing command line arguments.
> > 
> > Learn to read the connection file from standard input for such use
> > case.
> > 
> > This allows a parent process to set the connection details without
> > intermediary file.
> > 
> > Signed-off-by: Marc-André Lureau <marcandre.lureau at redhat.com>
> > Reviewed-by: Victor Toso <victortoso at redhat.com>
> > ---
> >  man/remote-viewer.pod  |  3 +++
> >  src/remote-viewer.c    | 46 ++++++++++++++++++++++++++++++++++++++++------
> >  src/virt-viewer-file.c | 31 +++++++++++++++++++++++++------
> >  src/virt-viewer-file.h |  2 ++
> >  4 files changed, 70 insertions(+), 12 deletions(-)
> > 
> > diff --git a/man/remote-viewer.pod b/man/remote-viewer.pod
> > index 60ea3a6..8428c80 100644
> > --- a/man/remote-viewer.pod
> > +++ b/man/remote-viewer.pod
> > @@ -18,6 +18,9 @@ entry and a list of previously successfully accessed URI.
> >  The URI can also point to a connection settings file, see the CONNECTION
> >  FILE
> >  section for a description of the format.
> >  
> > +If URI is '-', then remote-viewer will read the standard input as a
> > +connection settings file and attempt to connect using it.
> > +
> >  =head1 OPTIONS
> >  
> >  The following options are accepted when running C<remote-viewer>:
> > diff --git a/src/remote-viewer.c b/src/remote-viewer.c
> > index fb5376c..e082178 100644
> > --- a/src/remote-viewer.c
> > +++ b/src/remote-viewer.c
> > @@ -1084,6 +1084,22 @@ remote_viewer_session_connected(VirtViewerSession
> > *session,
> >      g_free(uri);
> >  }
> >  
> > +static gchar *
> > +read_all_stdin(gsize *len, GError **err)
> > +{
> > +    GIOChannel *ioc = g_io_channel_unix_new(fileno(stdin));
> > +    gchar *content = NULL;
> > +    GIOStatus status;
> > +
> > +    status = g_io_channel_read_to_end(ioc, &content, len, err);
> > +    g_assert(status != G_IO_STATUS_AGAIN && status != G_IO_STATUS_EOF);
> 
> "G_IO_STATUS_NORMAL on success. This function never returns G_IO_STATUS_EOF"

Yes, I also want to assert we don't get AGAIN (or should we loop?) I don't think it's necessary, stdin should be blocking and this would be a weird case, wouldn't it?

> 
> > +
> > +    g_io_channel_unref(ioc);
> > +    g_assert((content && !*err) || (!content && *err));
> 
> This seems that you are sanity checking g_io_channel_read_to_end() ?

I want to make sure that either we get an error or we get content, not both. It's not clear for the API (for ex with AGAIN).

> 
> If you want to assert here, I guess just use g_assert_no_error()
> instead ?

That was basically the approach before, let the function return NULL, and fail later when reading from NULL buffer with keyfile.

Now if we want to produce a error message instead, we should propagate GError.

Other solution is to pring the GError immediately if any, and return NULL in that case. Anything works for me.

> 
> > +
> > +    return content;
> > +}
> > +
> >  static gboolean
> >  remote_viewer_initial_connect(RemoteViewer *self, const gchar *type,
> >                                VirtViewerFile *vvfile, GError **error)
> > @@ -1174,16 +1190,34 @@ retry_dialog:
> >  
> >          g_debug("Opening display to %s", guri);
> >  
> > -        file = g_file_new_for_commandline_arg(guri);
> > -        if (g_file_query_exists(file, NULL)) {
> > -            gchar *path = g_file_get_path(file);
> > -            vvfile = virt_viewer_file_new(path, &error);
> > -            g_free(path);
> > +        if (!g_strcmp0(guri, "-")) {
> > +            gsize len = 0;
> > +            gchar *buf = read_all_stdin(&len, &error);
> > +
> >              if (error) {
> > -                g_prefix_error(&error, _("Invalid file %s: "), guri);
> > +                g_prefix_error(&error, _("Failed to read stdin: "));
> >                  g_warning("%s", error->message);
> >                  goto cleanup;
> >              }
> > +
> > +            vvfile = virt_viewer_file_new_from_buffer(buf, len, &error);
> > +            g_free(buf);
> > +        } else {
> > +            file = g_file_new_for_commandline_arg(guri);
> > +            if (g_file_query_exists(file, NULL)) {
> > +                gchar *path = g_file_get_path(file);
> > +                vvfile = virt_viewer_file_new(path, &error);
> > +                g_free(path);
> > +            }
> > +        }
> > +
> > +        if (error) {
> > +            g_prefix_error(&error, _("Invalid file %s: "), guri);
> > +            g_warning("%s", error->message);
> > +            goto cleanup;
> > +        }
> > +
> > +        if (vvfile) {
> >              g_object_get(G_OBJECT(vvfile), "type", &type, NULL);
> >          } else if (virt_viewer_util_extract_host(guri, &type, NULL, NULL,
> >          NULL, NULL) < 0 || type == NULL) {
> >              g_set_error_literal(&error,
> > diff --git a/src/virt-viewer-file.c b/src/virt-viewer-file.c
> > index 9ff2a05..1b0c310 100644
> > --- a/src/virt-viewer-file.c
> > +++ b/src/virt-viewer-file.c
> > @@ -139,16 +139,15 @@ enum  {
> >  };
> >  
> >  VirtViewerFile*
> > -virt_viewer_file_new(const gchar* location, GError** error)
> > +virt_viewer_file_new_from_buffer(const gchar* data, gsize len,
> > +                                 GError** error)
> >  {
> >      GError* inner_error = NULL;
> > -
> > -    g_return_val_if_fail (location != NULL, NULL);
> > -
> >      VirtViewerFile* self =
> >      VIRT_VIEWER_FILE(g_object_new(VIRT_VIEWER_TYPE_FILE, NULL));
> >      GKeyFile* keyfile = self->priv->keyfile;
> >  
> > -    g_key_file_load_from_file(keyfile, location,
> > +    g_return_val_if_fail(data != NULL, NULL);
> > +    g_key_file_load_from_data(keyfile, data, len,
> >                                G_KEY_FILE_KEEP_COMMENTS |
> >                                G_KEY_FILE_KEEP_TRANSLATIONS,
> >                                &inner_error);
> >      if (inner_error != NULL) {
> > @@ -166,7 +165,27 @@ virt_viewer_file_new(const gchar* location, GError**
> > error)
> >          return NULL;
> >      }
> >  
> > -    if (virt_viewer_file_get_delete_this_file(self) &&
> > +    return self;
> > +}
> > +
> > +VirtViewerFile*
> > +virt_viewer_file_new(const gchar* location, GError** error)
> > +{
> > +    VirtViewerFile *self;
> > +    gchar *buf;
> > +    gsize len;
> > +
> > +    g_return_val_if_fail (location != NULL, NULL);
> > +
> > +    if (!g_file_get_contents(location, &buf, &len, error)) {
> > +        return NULL;
> > +    }
> > +
> > +    self = virt_viewer_file_new_from_buffer(buf, len, error);
> > +    g_free(buf);
> > +
> > +
> > +    if (self && virt_viewer_file_get_delete_this_file(self) &&
> >          !g_getenv("VIRT_VIEWER_KEEP_FILE")) {
> >          if (g_unlink(location) != 0)
> >              g_warning("failed to remove %s", location);
> > diff --git a/src/virt-viewer-file.h b/src/virt-viewer-file.h
> > index 6b783f9..15c61d0 100644
> > --- a/src/virt-viewer-file.h
> > +++ b/src/virt-viewer-file.h
> > @@ -50,6 +50,8 @@ struct _VirtViewerFileClass
> >  GType virt_viewer_file_get_type(void);
> >  
> >  VirtViewerFile* virt_viewer_file_new(const gchar* path, GError** error);
> > +VirtViewerFile* virt_viewer_file_new_from_buffer(const gchar* buf, gsize
> > len,
> > +                                                 GError** error);
> >  gboolean virt_viewer_file_is_set(VirtViewerFile* self, const gchar* key);
> >  
> >  gchar* virt_viewer_file_get_ca(VirtViewerFile* self);
> > --
> > 2.15.0.125.g8f49766d64
> > 
> 




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