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		1b6521e695
		
	
	
	
	
		
			
			In order to support system compositor instances, it is necessary to allow clients' wl_display_connect() to find the compositor's listening socket somewhere outside of XDG_RUNTIME_DIR. For a full account, see the discussion beginning here: https://lists.freedesktop.org/archives/wayland-devel/2017-November/035664.html This change adjusts the client-side connection logic so that, if WAYLAND_DISPLAY is formatted as an absolute pathname, the socket connection attempt is made to just $WAYLAND_DISPLAY rather than usual user-private location $XDG_RUNTIME_DIR/$WAYLAND_DISPLAY. This change is based on Davide Bettio's submission of the same concept at: https://lists.freedesktop.org/archives/wayland-devel/2015-August/023838.html. v4 changes: * Improved internal comments and some boundary-condition error checks in test case. * Refer to compositor as "Wayland server" rather than "Wayland display" in wl_display_connect() doxygen comments. * Remove redundant descriptions of parameter-interpretation mechanics from wl_display_connect() manpage. Reworked things to make it clear that 'name' and $WAYLAND_DISLAY are each capable of encoding absolute server socket paths. * Remove callout to reference implementation behavior in protocol documented. In its place there is now a simple statement that implementations can optionally support absolute socket paths. v3 changes: * Added test case. * Clarified documentation to note that 'name' parameter to wl_display_connect() can also be an absolute path. v2 changes: * Added backward incompatibility note to wl_display_connect() manpage. * Rephased wl_display_connect() manpage changes to precisely match actual changed behavior. * Added mention of new absolute path behavior in wl_display_connect() doxygen comments. * Mentioned new absolute path interpretation of WAYLAND_DISPLAY in protocol documentation. Signed-off-by: Matt Hoosier <matt.hoosier@gmail.com> Acked-by: Jonas Ådahl <jadahl@gmail.com> Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
		
			
				
	
	
		
			284 lines
		
	
	
	
		
			7.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			284 lines
		
	
	
	
		
			7.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Permission is hereby granted, free of charge, to any person obtaining
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|  * a copy of this software and associated documentation files (the
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|  * "Software"), to deal in the Software without restriction, including
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|  * without limitation the rights to use, copy, modify, merge, publish,
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|  * distribute, sublicense, and/or sell copies of the Software, and to
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|  * permit persons to whom the Software is furnished to do so, subject to
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|  * the following conditions:
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|  *
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|  * The above copyright notice and this permission notice (including the
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|  * next paragraph) shall be included in all copies or substantial
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|  * portions of the Software.
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|  *
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|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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|  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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|  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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|  * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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|  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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|  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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|  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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|  * SOFTWARE.
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|  */
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| 
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| #include <stdlib.h>
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| #include <assert.h>
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| #include <errno.h>
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| #include <string.h>
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| #include <stdio.h>
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| #include <sys/socket.h>
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| #include <sys/types.h>
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| #include <sys/wait.h>
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| #include <sys/un.h>
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| #include <unistd.h>
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| 
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| #include "wayland-client.h"
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| #include "wayland-os.h"
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| #include "wayland-server.h"
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| #include "test-runner.h"
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| 
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| /* Paths longer than what the .sun_path array can contain must be rejected.
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|  * This is a hard limitation of assigning a name to AF_UNIX/AF_LOCAL sockets.
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|  * See `man 7 unix`.
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|  */
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| 
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| static const struct sockaddr_un example_sockaddr_un;
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| 
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| #define TOO_LONG (1 + sizeof example_sockaddr_un.sun_path)
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| 
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| /* Ensure the connection doesn't fail due to lack of XDG_RUNTIME_DIR. */
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| static const char *
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| require_xdg_runtime_dir(void)
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| {
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| 	char *val = getenv("XDG_RUNTIME_DIR");
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| 	assert(val && "set $XDG_RUNTIME_DIR to run this test");
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| 
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| 	return val;
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| }
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| 
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| TEST(socket_path_overflow_client_connect)
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| {
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| 	char path[TOO_LONG];
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| 	struct wl_display *d;
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| 
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| 	require_xdg_runtime_dir();
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| 
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| 	memset(path, 'a', sizeof path);
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| 	path[sizeof path - 1] = '\0';
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| 
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| 	d = wl_display_connect(path);
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| 	assert(d == NULL);
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| 	assert(errno == ENAMETOOLONG);
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| }
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| 
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| TEST(socket_path_overflow_server_create)
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| {
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| 	char path[TOO_LONG];
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| 	struct wl_display *d;
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| 	int ret;
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| 
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| 	require_xdg_runtime_dir();
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| 
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| 	memset(path, 'a', sizeof path);
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| 	path[sizeof path - 1] = '\0';
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| 
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| 	d = wl_display_create();
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| 	assert(d != NULL);
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| 
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| 	ret = wl_display_add_socket(d, path);
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| 	assert(ret < 0);
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| 	assert(errno == ENAMETOOLONG);
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| 
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| 	wl_display_destroy(d);
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| }
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| 
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| TEST(add_existing_socket)
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| {
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| 	char path[sizeof example_sockaddr_un.sun_path];
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| 	const char *name = "wayland-test-0";
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| 	const char *xdg_runtime_dir;
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| 	struct wl_display *d;
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| 	int ret;
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| 	size_t len;
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| 
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| 	xdg_runtime_dir = require_xdg_runtime_dir();
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| 
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| 	d = wl_display_create();
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| 	assert(d != NULL);
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| 
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| 	/* this one should be OK */
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| 	ret = wl_display_add_socket(d, name);
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| 	assert(ret == 0);
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| 
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| 	/* this one should fail */
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| 	ret = wl_display_add_socket(d, name);
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| 	assert(ret < 0);
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| 
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| 	/* the original socket should still exist.
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| 	 * this was a bug introduced in e2c0d47b0c77f18cd90e9c6eabb358c4d89681c8 */
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| 	len = snprintf(path, sizeof example_sockaddr_un.sun_path, "%s/%s",
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| 		       xdg_runtime_dir, name);
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| 	assert(len < sizeof example_sockaddr_un.sun_path
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| 	       && "Bug in test. Path too long");
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| 
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| 	assert(access(path, F_OK) != -1);
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| 
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| 	/* the original socket should still exist */
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| 	ret = wl_display_add_socket(d, name);
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| 	assert(ret < 0);
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| 
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| 	wl_display_destroy(d);
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| }
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| 
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| TEST(add_socket_auto)
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| {
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| 	/* the number of auto sockets is currently 32,
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| 	 * set in wayland-server.c.
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| 	 */
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| 	const int MAX_SOCKETS = 32;
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| 
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| 	char path[sizeof example_sockaddr_un.sun_path];
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| 	const char *name;
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| 	const char *xdg_runtime_dir;
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| 	struct wl_display *d;
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| 	int i;
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| 	size_t len;
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| 
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| 	xdg_runtime_dir = require_xdg_runtime_dir();
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| 
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| 	d = wl_display_create();
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| 	assert(d != NULL);
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| 
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| 	for (i = 0; i <= MAX_SOCKETS; ++i) {
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| 		name = wl_display_add_socket_auto(d);
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| 		assert(name != NULL);
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| 
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| 		len = snprintf(path, sizeof example_sockaddr_un.sun_path,
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| 			       "%s/%s", xdg_runtime_dir, name);
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| 		assert(len < sizeof example_sockaddr_un.sun_path
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| 		       && "Bug in test. Path too long");
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| 
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| 		/* was the socket created correctly? */
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| 		assert(access(path, F_OK) != -1);
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| 
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| 		/* is the name sequential? */
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| 		len = snprintf(path, sizeof example_sockaddr_un.sun_path,
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| 			       "wayland-%d", i);
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| 		assert(strcmp(name, path) == 0);
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| 	}
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| 
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| 	/* next addition should return NULL */
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| 	name = wl_display_add_socket_auto(d);
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| 	assert(name == NULL);
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| 
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| 	/* check if the socket was not deleted the last time */
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| 	name = wl_display_add_socket_auto(d);
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| 	assert(name == NULL);
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| 
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| 	wl_display_destroy(d);
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| }
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| 
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| struct client_create_listener {
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| 	struct wl_listener listener;
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| 	struct wl_display *display;
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| };
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| 
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| struct client_destroy_listener {
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| 	struct wl_listener listener;
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| 	struct wl_display *display;
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| };
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| 
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| static void
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| client_destroy_notify(struct wl_listener *l, void *data)
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| {
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| 	struct client_destroy_listener *listener =
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| 		wl_container_of(l, listener, listener);
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| 	wl_display_terminate(listener->display);
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| 	free(listener);
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| }
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| 
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| static void
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| client_create_notify(struct wl_listener *l, void *data)
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| {
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| 	struct wl_client *client = data;
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| 	struct client_create_listener *listener =
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| 		wl_container_of(l, listener, listener);
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| 	struct client_destroy_listener *destroy_listener = (struct client_destroy_listener *)malloc(sizeof *destroy_listener);
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| 	assert(destroy_listener != NULL);
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| 	destroy_listener->display = listener->display;
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| 	destroy_listener->listener.notify = client_destroy_notify;
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| 	wl_client_add_destroy_listener(client, &destroy_listener->listener);
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| }
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| 
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| TEST(absolute_socket_path)
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| {
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| 	struct wl_display *display;
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| 	struct client_create_listener client_create_listener;
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| 	struct sockaddr_un addr;
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| 	int fd;
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| 	socklen_t size;
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| 	const char *xdg_runtime_dir;
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| 	size_t len;
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| 	int ret;
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| 	pid_t pid;
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| 
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| 	/* It's a little weird that this test about absolute socket paths
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| 	 * uses XDG_RUNTIME_DIR, but that's the only location guaranteed
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| 	 * by test-runner to be both writable and unique. This isn't
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| 	 * really a problem; we'll just take care that the leaf-level
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| 	 * filename used for the socket isn't anything that would
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| 	 * accidentally be generated by a default usage of wl_display_connect(). */
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| 	xdg_runtime_dir = require_xdg_runtime_dir();
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| 	memset(&addr, 0, sizeof addr);
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| 	len = snprintf(addr.sun_path, sizeof addr.sun_path,
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| 		       "%s/%s", xdg_runtime_dir, "wayland-absolute-0");
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| 	assert(len < sizeof addr.sun_path
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| 	       && "Bug in test. Path too long");
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| 
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| 	/* The path must not exist prior to binding. */
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| 	assert(access(addr.sun_path, F_OK) == -1);
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| 
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| 	size = offsetof (struct sockaddr_un, sun_path) + strlen(addr.sun_path);
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| 	addr.sun_family = AF_LOCAL;
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| 	fd = wl_os_socket_cloexec(PF_LOCAL, SOCK_STREAM, 0);
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| 	assert(fd >= 0 );
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| 	ret = bind(fd, (struct sockaddr *) &addr, size);
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| 	assert(ret >= 0);
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| 	ret = listen(fd, 128);
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| 	assert(ret >= 0);
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| 
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| 	/* Start server display. Be careful (by avoiding wl_display_add_socket_auto()
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| 	 * to offer only the absolutely qualified socket made above. */
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| 	display = wl_display_create();
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| 	assert(display != NULL);
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| 	client_create_listener.listener.notify = client_create_notify;
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| 	client_create_listener.display = display;
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| 	wl_display_add_client_created_listener(display, &client_create_listener.listener);
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| 	ret = wl_display_add_socket_fd(display, fd);
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| 	assert(ret == 0);
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| 
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| 	/* Execute client that connects to the absolutely qualified server socket path. */
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| 	pid = fork();
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| 	assert(pid != -1);
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| 
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| 	if (pid == 0) {
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| 		ret = setenv("WAYLAND_DISPLAY", addr.sun_path, 1);
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| 		assert(ret == 0);
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| 		struct wl_display *client_display = wl_display_connect(NULL);
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| 		assert(client_display != NULL);
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| 		ret = wl_display_roundtrip(client_display);
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| 		assert(ret != -1);
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| 		wl_display_disconnect(client_display);
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| 		exit(0);
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| 		assert(false);
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| 	}
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| 
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| 	wl_display_run(display);
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| 	ret = waitpid(pid, NULL, 0);
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| 	assert(ret == pid);
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| 
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| 	wl_display_destroy(display);
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| 
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| 	ret = unlink(addr.sun_path);
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| 	assert(ret == 0);
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| }
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