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Core Wayland window system code and protocol
f6b78b76b2
This function constructs a socket path in sun_path using snprintf, which returns the amount of space that would have been used if the buffer was large enough. It then checks if this is larger then the actual buffer size and, if so, returns ENAMETOOLONG. This is correct. However, after calling snprintf and before checking that the length isn't too long, it tries to compute a pointer to the part of the path that matches the input name. It does this by adding the computed path length to the pointer to the start of the path buffer, which will take it to one-past the null terminator, and then walking backwards. If the path fits in the buffer, this will take it at most one-past-the-end of the allocation, which is allowed, but if the path is longer then the buffer then the pointer addition is undefined behavior. Fix this by moving the display name computation past the check that the path length is not too long. This is detected by the test socket_path_overflow_server_create under ubsan. Signed-off-by: Fergus Dall <sidereal@google.com> |
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| CONTRIBUTING.md | ||
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| README | ||
| releasing.txt | ||
| wayland-scanner.m4 | ||
| wayland-scanner.mk | ||
What is Wayland?
Wayland is a project to define a protocol for a compositor to talk to
its clients as well as a library implementation of the protocol. The
compositor can be a standalone display server running on Linux kernel
modesetting and evdev input devices, an X application, or a wayland
client itself. The clients can be traditional applications, X servers
(rootless or fullscreen) or other display servers.
The wayland protocol is essentially only about input handling and
buffer management. The compositor receives input events and forwards
them to the relevant client. The clients creates buffers and renders
into them and notifies the compositor when it needs to redraw. The
protocol also handles drag and drop, selections, window management and
other interactions that must go through the compositor. However, the
protocol does not handle rendering, which is one of the features that
makes wayland so simple. All clients are expected to handle rendering
themselves, typically through cairo or OpenGL.
The weston compositor is a reference implementation of a wayland
compositor and the weston repository also includes a few example
clients.
Building the wayland libraries is fairly simple, aside from libffi,
they don't have many dependencies:
$ git clone https://gitlab.freedesktop.org/wayland/wayland
$ cd wayland
$ meson build/ --prefix=PREFIX
$ ninja -C build/ install
where PREFIX is where you want to install the libraries. See
https://wayland.freedesktop.org for more complete build instructions
for wayland, weston, xwayland and various toolkits.