I personally find it more convenient to have pasted data written to
the X11 PRIMARY selection, so that I can paste it with a fast middle-
button click, than to write to CLIPBOARD which typically needs a key
sequence or menu action.
This commit adds a command-line option to let me express that
preference: now I can say "/clipboard:use-selection:PRIMARY" on the
command line, which not only enables clipboard transfer but also says
which X selection I want it to talk to. The previous options
"+clipboard" and "-clipboard" are also still supported.
A selection owner is supposed to respond to a request for the
selection target TIMESTAMP by providing the X server time at which the
selection was written. There was a /* TODO */ comment in xf_cliprdr
where the code to do that should have been.
The absence of this can cause a problem when pasting into some X
clients. xtightvncviewer, in particular, will give up the attempt to
read from the clipboard at all if it doesn't get a satisfactory
response to the initial TIMESTAMP request - and the non-answer zero
value "CurrentTime" counts as unsatisfactory. It won't be happy with
anything short of a real X server time value.
(Checking the VNC source code, that's because it reads both PRIMARY
and CLIPBOARD and picks the one with the later timestamp. So it does
depend on the timestamps existing.)
When you're writing to the selection in response to a normal X event
like a mouse click or keyboard action, you get the selection timestamp
by copying the time field out of that X event. Here, we're doing it on
our own initiative, so we have to _request_ the X server time. There
isn't a GetServerTime request in the X protocol, so I work around it
by setting a property on our own window, and waiting for a
PropertyNotify event to come back telling me it's been done - which
will have a timestamp we can use.
According to the channel docs, this field is only used in format data
request. Therefore, there's no need to hold it in the response. cliprdr
server code was copy-pasted from client code, therefore this must be
some leftover.
Clipboard formats containing plain text are specified to be terminated
by a \0 character in MS's documentation on standard clipboard formats:
https://docs.microsoft.com/en-us/windows/desktop/dataxchg/standard-clipboard-formats
xf_cliprdr_server_format_data_response receives pasted data from the
server to transfer to the client, in a sufficiently raw form that the
\0 terminator is still present, so it has to remove it. It does so by
checking only at the very end of the data. But I've observed that when
pasting out of at least one Windows program (namely Outlook 1903 on
Windows 10), the intended paste data arrives in this function followed
by \0 and then a spurious \n. In that situation the null-terminator
removal will fail to notice the \0, and will leave both bogus
characters on the end of the paste.
Fixed by using memchr to find the _first_ \0 in the paste data, which
should not lose any actually intentional data because it's in
accordance with the spec above.
The file clipboard delegate needs a base URI to operate on for
systems that are not WIN32. Added that to the context and abort
conversion, if that is not set. (currently not fully implemented)
The data provided by local applications can be actually encoded in
UTF-16 (e.g., Firefox does this to HTML). UTF-16 allows embedded null
bytes so we should not use strlen() to fix up the data. The HTML format
synthesizer can handle trailing null bytes just fine and can detect
whether it deals with UTF-8 or UTF-16.
Most of the functions is this file are internal-use callbacks so they do
not need to be exported from the compilation unit. Mark functions static
as appropriate.
Now that we've got everything in place to handle files it's time to tell
the server that we can actually do this.
MS-RDPECLIP 3.2.5.1.3 Sending a Client Clipboard Capabilities PDU asks
us politely to not advertise file clipping support if the server did not
do that itself. Thus we need to parse the capabilities sent by the
server and take a note whether it supports file clipping.
There is also no point in advertising file clipping support if
wClipboard failed to initalize any local file subsystem, in which case
we cannot handle files for real. Take a note of this as well when we
register the file formats.
If everthing is really in place and the stars shine upon us then we are
allowed to set CB_STREAM_FILECLIP_ENABLED in the capabilities. There is
no command line switch to disable file clipping (and there is little
reason to), so we always support it if we can.
We also set an additional flag CB_FILECLIP_NO_FILE_PATHS flag in the
capabilities because it seems to be necessary for the server to send the
"FileGroupDescriptorW" format to us. Otherwise the server will only send
the old CF_HDROP format which can't be handled well without enabled disk
drive redirection and a properly negotiated server-side temporary
directory.
xf_cliprdr_server_file_contents_request() handles the
CLIPRDR_FILECONTENTS_REQUEST which is sent by the server to retrieve the
size or data of a single file. The server can only request one of these
things at a time, do confirm this.
The actual handling of the requests is done by wClipboardDelegate. In
order to handle its resposes we register a bunch of our own callbacks
which simply pass the responses to the server.
In case of an error we should always send a CB_RESPONSE_FAIL to the
server. If we do not then the file transfer progress dialog may end up
hanging in the remote session forever until the user logs out or kills
explorer.exe. We do wnat this.
To handle a new format we should first be able to transform the format
name from the local clipboard owner into its remote representation. In
our case this will be trasforming the "text/uri-list" target into the
"FileGroupDescriptorW" named format.
Add CB_FORMAT_TEXTURILIST to identify the local format by its ID during
the data conversion step. This numeric ID has nothing to do with the ID
which will be sent to server. It's a bit weird, but that's how XFreeRDP
works.
After that add a new client format with this ID and appropriate local
and remote format names (in atom and formatName fields respectively).
Do this only if wClipboard actually supports "text/uri-list" format.
(It could fail to initialize the local file subsystem, in which case
it will fail all file-related requests and there would be no point in
advertising the file format support in the first place.)
Finally, handle the actual format data request for a new named format
in xf_cliprdr_process_requested_data(). Remember to convert the
FILEDESCRIPTOR array we receive from wClipboard into the
CLIPRDR_FILELIST expected by the server. Also take care to not leak
memory during this conversion.
Note that this handles only the CLIPRDR_FORMAT_DATA_REQUEST. The server
is still not able to retrieve the file content as this is done via a
separate request-reply sequence.
Unify error handling in xf_clipboard_new() by using a common cleanup
code path. This fixes a leak of clipboard->system and format names when
an error occurs during initialization.
Also reformat the code to fit into 100 column limit without this line
break insanity and with improved readability.
I do not particularly like to use a variable with such a descriptive
name 'n' far away in the error handling part, but its short name is
kinda important for readability so let's keep it as is.
FreeRDP uses clipboard->data to cache the result of the Windows->X11
clipboard format conversion, and xf_cliprdr_process_selection_request()
immediately provides this result to local applications if they request
the same clipboard format again. This saves us a possibly costly
conversion in case where the user pastes data repeatedly.
However, this caching mechanism did not support raw clipboard transfers
where the unmodified data is passed between two FreeRDP clients. We use
the same XClipboard protocol for this, so the clipboard->data is in play.
We clear the cached value when we receive new data from the server, so
initially raw transfers are fine. But if some local application (e.g.,
a clipboard manager) asks for some data format before the data is pasted
into the second FreeRDP session then clipboard->data will contain the
*converted* data. And this converted cached data will be provided to
the second FreeRDP session as a part of the raw data transfer. Instead
we should have provided the original data.
In order to achieve this we are now caching the original data in the
same way as the converted one, and the original data is now correctly
provided when the second FreeRDP session asks for a raw data transfer.
[channels/tsmf/client/gstreamer/tsmf_X11.c:317] -> [channels/tsmf/client/gstreamer/tsmf_X11.c:322]: (warning) Either the condition '!decoder' is redundant or there is possible null pointer dereference: decoder.
[channels/tsmf/client/gstreamer/tsmf_X11.c:470] -> [channels/tsmf/client/gstreamer/tsmf_X11.c:475]: (warning) Either the condition '!decoder' is redundant or there is possible null pointer dereference: decoder.
[channels/tsmf/client/gstreamer/tsmf_X11.c:472] -> [channels/tsmf/client/gstreamer/tsmf_X11.c:475]: (warning) Either the condition '!decoder' is redundant or there is possible null pointer dereference: decoder.
[channels/tsmf/client/tsmf_media.c:179] -> [channels/tsmf/client/tsmf_media.c:181]: (warning) Either the condition '!stream' is redundant or there is possible null pointer dereference: stream.
[client/Windows/wf_cliprdr.c:2219] -> [client/Windows/wf_cliprdr.c:2222]: (warning) Either the condition '!formatDataResponse' is redundant or there is possible null pointer dereference: formatDataResponse
[client/Windows/wf_cliprdr.c:2445] -> [client/Windows/wf_cliprdr.c:2448]: (warning) Either the condition '!fileContentsResponse' is redundant or there is possible null pointer dereference: fileContentsResponse.
[client/X11/xf_cliprdr.c:911] -> [client/X11/xf_cliprdr.c:913]: (warning) Either the condition '!clipboard' is redundant or there is possible null pointer dereference: clipboard.
[client/X11/xf_graphics.c:504] -> [client/X11/xf_graphics.c:506]: (warning) Either the condition '!xfc' is redundant or there is possible null pointer dereference: xfc.
[libfreerdp/core/transport.c:861] -> [libfreerdp/core/transport.c:863]: (warning) Either the condition '!transport' is redundant or there is possible null pointer dereference: transport.
[server/shadow/shadow_server.c:777] -> [server/shadow/shadow_server.c:791]: (warning) Either the condition '!server' is redundant or there is possible null pointer dereference: server.
[server/shadow/shadow_server.c:778] -> [server/shadow/shadow_server.c:791]: (warning) Either the condition '!server' is redundant or there is possible null pointer dereference: server.
[server/shadow/shadow_server.c:779] -> [server/shadow/shadow_server.c:791]: (warning) Either the condition '!server' is redundant or there is possible null pointer dereference: server.
[server/shadow/shadow_server.c:781] -> [server/shadow/shadow_server.c:791]: (warning) Either the condition '!server' is redundant or there is possible null pointer dereference: server.
[server/shadow/shadow_server.c:782] -> [server/shadow/shadow_server.c:791]: (warning) Either the condition '!server' is redundant or there is possible null pointer dereference: server.
[server/shadow/shadow_server.c:783] -> [server/shadow/shadow_server.c:791]: (warning) Either the condition '!server' is redundant or there is possible null pointer dereference: server.
[server/shadow/shadow_server.c:784] -> [server/shadow/shadow_server.c:791]: (warning) Either the condition '!server' is redundant or there is possible null pointer dereference: server.
[server/shadow/shadow_server.c:785] -> [server/shadow/shadow_server.c:791]: (warning) Either the condition '!server' is redundant or there is possible null pointer dereference: server.
[server/shadow/shadow_server.c:787] -> [server/shadow/shadow_server.c:791]: (warning) Either the condition '!server' is redundant or there is possible null pointer dereference: server.
[server/shadow/shadow_server.c:789] -> [server/shadow/shadow_server.c:791]: (warning) Either the condition '!server' is redundant or there is possible null pointer dereference: server.
- fixed invalid, missing or additional arguments
- removed all type casts from arguments
- added missing (void*) typecasts for %p arguments
- use inttypes defines where appropriate
