377 lines
		
	
	
	
		
			12 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
		
		
			
		
	
	
			377 lines
		
	
	
	
		
			12 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
|   | /*
 | ||
|  | 
 | ||
|  | Copyright (c) 2017-2019, Feral Interactive | ||
|  | All rights reserved. | ||
|  | 
 | ||
|  | Redistribution and use in source and binary forms, with or without | ||
|  | modification, are permitted provided that the following conditions are met: | ||
|  | 
 | ||
|  |  * Redistributions of source code must retain the above copyright notice, | ||
|  |    this list of conditions and the following disclaimer. | ||
|  |  * Redistributions in binary form must reproduce the above copyright | ||
|  |    notice, this list of conditions and the following disclaimer in the | ||
|  |    documentation and/or other materials provided with the distribution. | ||
|  |  * Neither the name of Feral Interactive nor the names of its contributors | ||
|  |    may be used to endorse or promote products derived from this software | ||
|  |    without specific prior written permission. | ||
|  | 
 | ||
|  | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | ||
|  | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
|  | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
|  | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | ||
|  | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | ||
|  | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | ||
|  | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | ||
|  | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | ||
|  | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | ||
|  | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | ||
|  | POSSIBILITY OF SUCH DAMAGE. | ||
|  | 
 | ||
|  |  */ | ||
|  | #ifndef CLIENT_GAMEMODE_H
 | ||
|  | #define CLIENT_GAMEMODE_H
 | ||
|  | /*
 | ||
|  |  * GameMode supports the following client functions | ||
|  |  * Requests are refcounted in the daemon | ||
|  |  * | ||
|  |  * int gamemode_request_start() - Request gamemode starts | ||
|  |  *   0 if the request was sent successfully | ||
|  |  *   -1 if the request failed | ||
|  |  * | ||
|  |  * int gamemode_request_end() - Request gamemode ends | ||
|  |  *   0 if the request was sent successfully | ||
|  |  *   -1 if the request failed | ||
|  |  * | ||
|  |  * GAMEMODE_AUTO can be defined to make the above two functions apply during static init and | ||
|  |  * destruction, as appropriate. In this configuration, errors will be printed to stderr | ||
|  |  * | ||
|  |  * int gamemode_query_status() - Query the current status of gamemode | ||
|  |  *   0 if gamemode is inactive | ||
|  |  *   1 if gamemode is active | ||
|  |  *   2 if gamemode is active and this client is registered | ||
|  |  *   -1 if the query failed | ||
|  |  * | ||
|  |  * int gamemode_request_start_for(pid_t pid) - Request gamemode starts for another process | ||
|  |  *   0 if the request was sent successfully | ||
|  |  *   -1 if the request failed | ||
|  |  *   -2 if the request was rejected | ||
|  |  * | ||
|  |  * int gamemode_request_end_for(pid_t pid) - Request gamemode ends for another process | ||
|  |  *   0 if the request was sent successfully | ||
|  |  *   -1 if the request failed | ||
|  |  *   -2 if the request was rejected | ||
|  |  * | ||
|  |  * int gamemode_query_status_for(pid_t pid) - Query status of gamemode for another process | ||
|  |  *   0 if gamemode is inactive | ||
|  |  *   1 if gamemode is active | ||
|  |  *   2 if gamemode is active and this client is registered | ||
|  |  *   -1 if the query failed | ||
|  |  * | ||
|  |  * const char* gamemode_error_string() - Get an error string | ||
|  |  *   returns a string describing any of the above errors | ||
|  |  * | ||
|  |  * Note: All the above requests can be blocking - dbus requests can and will block while the daemon | ||
|  |  * handles the request. It is not recommended to make these calls in performance critical code | ||
|  |  */ | ||
|  | 
 | ||
|  | #include <stdbool.h>
 | ||
|  | #include <stdio.h>
 | ||
|  | 
 | ||
|  | #include <dlfcn.h>
 | ||
|  | #include <string.h>
 | ||
|  | 
 | ||
|  | #include <assert.h>
 | ||
|  | 
 | ||
|  | #include <sys/types.h>
 | ||
|  | 
 | ||
|  | static char internal_gamemode_client_error_string[512] = { 0 }; | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * Load libgamemode dynamically to dislodge us from most dependencies. | ||
|  |  * This allows clients to link and/or use this regardless of runtime. | ||
|  |  * See SDL2 for an example of the reasoning behind this in terms of | ||
|  |  * dynamic versioning as well. | ||
|  |  */ | ||
|  | static volatile int internal_libgamemode_loaded = 1; | ||
|  | 
 | ||
|  | /* Typedefs for the functions to load */ | ||
|  | typedef int (*api_call_return_int)(void); | ||
|  | typedef const char *(*api_call_return_cstring)(void); | ||
|  | typedef int (*api_call_pid_return_int)(pid_t); | ||
|  | 
 | ||
|  | /* Storage for functors */ | ||
|  | static api_call_return_int REAL_internal_gamemode_request_start = NULL; | ||
|  | static api_call_return_int REAL_internal_gamemode_request_end = NULL; | ||
|  | static api_call_return_int REAL_internal_gamemode_query_status = NULL; | ||
|  | static api_call_return_cstring REAL_internal_gamemode_error_string = NULL; | ||
|  | static api_call_pid_return_int REAL_internal_gamemode_request_start_for = NULL; | ||
|  | static api_call_pid_return_int REAL_internal_gamemode_request_end_for = NULL; | ||
|  | static api_call_pid_return_int REAL_internal_gamemode_query_status_for = NULL; | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * Internal helper to perform the symbol binding safely. | ||
|  |  * | ||
|  |  * Returns 0 on success and -1 on failure | ||
|  |  */ | ||
|  | __attribute__((always_inline)) static inline int internal_bind_libgamemode_symbol( | ||
|  |     void *handle, const char *name, void **out_func, size_t func_size, bool required) | ||
|  | { | ||
|  | 	void *symbol_lookup = NULL; | ||
|  | 	char *dl_error = NULL; | ||
|  | 
 | ||
|  | 	/* Safely look up the symbol */ | ||
|  | 	symbol_lookup = dlsym(handle, name); | ||
|  | 	dl_error = dlerror(); | ||
|  | 	if (required && (dl_error || !symbol_lookup)) { | ||
|  | 		snprintf(internal_gamemode_client_error_string, | ||
|  | 		         sizeof(internal_gamemode_client_error_string), | ||
|  | 		         "dlsym failed - %s", | ||
|  | 		         dl_error); | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	/* Have the symbol correctly, copy it to make it usable */ | ||
|  | 	memcpy(out_func, &symbol_lookup, func_size); | ||
|  | 	return 0; | ||
|  | } | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * Loads libgamemode and needed functions | ||
|  |  * | ||
|  |  * Returns 0 on success and -1 on failure | ||
|  |  */ | ||
|  | __attribute__((always_inline)) static inline int internal_load_libgamemode(void) | ||
|  | { | ||
|  | 	/* We start at 1, 0 is a success and -1 is a fail */ | ||
|  | 	if (internal_libgamemode_loaded != 1) { | ||
|  | 		return internal_libgamemode_loaded; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	/* Anonymous struct type to define our bindings */ | ||
|  | 	struct binding { | ||
|  | 		const char *name; | ||
|  | 		void **functor; | ||
|  | 		size_t func_size; | ||
|  | 		bool required; | ||
|  | 	} bindings[] = { | ||
|  | 		{ "real_gamemode_request_start", | ||
|  | 		  (void **)&REAL_internal_gamemode_request_start, | ||
|  | 		  sizeof(REAL_internal_gamemode_request_start), | ||
|  | 		  true }, | ||
|  | 		{ "real_gamemode_request_end", | ||
|  | 		  (void **)&REAL_internal_gamemode_request_end, | ||
|  | 		  sizeof(REAL_internal_gamemode_request_end), | ||
|  | 		  true }, | ||
|  | 		{ "real_gamemode_query_status", | ||
|  | 		  (void **)&REAL_internal_gamemode_query_status, | ||
|  | 		  sizeof(REAL_internal_gamemode_query_status), | ||
|  | 		  false }, | ||
|  | 		{ "real_gamemode_error_string", | ||
|  | 		  (void **)&REAL_internal_gamemode_error_string, | ||
|  | 		  sizeof(REAL_internal_gamemode_error_string), | ||
|  | 		  true }, | ||
|  | 		{ "real_gamemode_request_start_for", | ||
|  | 		  (void **)&REAL_internal_gamemode_request_start_for, | ||
|  | 		  sizeof(REAL_internal_gamemode_request_start_for), | ||
|  | 		  false }, | ||
|  | 		{ "real_gamemode_request_end_for", | ||
|  | 		  (void **)&REAL_internal_gamemode_request_end_for, | ||
|  | 		  sizeof(REAL_internal_gamemode_request_end_for), | ||
|  | 		  false }, | ||
|  | 		{ "real_gamemode_query_status_for", | ||
|  | 		  (void **)&REAL_internal_gamemode_query_status_for, | ||
|  | 		  sizeof(REAL_internal_gamemode_query_status_for), | ||
|  | 		  false }, | ||
|  | 	}; | ||
|  | 
 | ||
|  | 	void *libgamemode = NULL; | ||
|  | 
 | ||
|  | 	/* Try and load libgamemode */ | ||
|  | 	libgamemode = dlopen("libgamemode.so.0", RTLD_NOW); | ||
|  | 	if (!libgamemode) { | ||
|  | 		/* Attempt to load unversioned library for compatibility with older
 | ||
|  | 		 * versions (as of writing, there are no ABI changes between the two - | ||
|  | 		 * this may need to change if ever ABI-breaking changes are made) */ | ||
|  | 		libgamemode = dlopen("libgamemode.so", RTLD_NOW); | ||
|  | 		if (!libgamemode) { | ||
|  | 			snprintf(internal_gamemode_client_error_string, | ||
|  | 			         sizeof(internal_gamemode_client_error_string), | ||
|  | 			         "dlopen failed - %s", | ||
|  | 			         dlerror()); | ||
|  | 			internal_libgamemode_loaded = -1; | ||
|  | 			return -1; | ||
|  | 		} | ||
|  | 	} | ||
|  | 
 | ||
|  | 	/* Attempt to bind all symbols */ | ||
|  | 	for (size_t i = 0; i < sizeof(bindings) / sizeof(bindings[0]); i++) { | ||
|  | 		struct binding *binder = &bindings[i]; | ||
|  | 
 | ||
|  | 		if (internal_bind_libgamemode_symbol(libgamemode, | ||
|  | 		                                     binder->name, | ||
|  | 		                                     binder->functor, | ||
|  | 		                                     binder->func_size, | ||
|  | 		                                     binder->required)) { | ||
|  | 			internal_libgamemode_loaded = -1; | ||
|  | 			return -1; | ||
|  | 		}; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	/* Success */ | ||
|  | 	internal_libgamemode_loaded = 0; | ||
|  | 	return 0; | ||
|  | } | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * Redirect to the real libgamemode | ||
|  |  */ | ||
|  | __attribute__((always_inline)) static inline const char *gamemode_error_string(void) | ||
|  | { | ||
|  | 	/* If we fail to load the system gamemode, or we have an error string already, return our error
 | ||
|  | 	 * string instead of diverting to the system version */ | ||
|  | 	if (internal_load_libgamemode() < 0 || internal_gamemode_client_error_string[0] != '\0') { | ||
|  | 		return internal_gamemode_client_error_string; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	/* Assert for static analyser that the function is not NULL */ | ||
|  | 	assert(REAL_internal_gamemode_error_string != NULL); | ||
|  | 
 | ||
|  | 	return REAL_internal_gamemode_error_string(); | ||
|  | } | ||
|  | 
 | ||
|  | /**
 | ||
|  |  * Redirect to the real libgamemode | ||
|  |  * Allow automatically requesting game mode | ||
|  |  * Also prints errors as they happen. | ||
|  |  */ | ||
|  | #ifdef GAMEMODE_AUTO
 | ||
|  | __attribute__((constructor)) | ||
|  | #else
 | ||
|  | __attribute__((always_inline)) static inline | ||
|  | #endif
 | ||
|  | int gamemode_request_start(void) | ||
|  | { | ||
|  | 	/* Need to load gamemode */ | ||
|  | 	if (internal_load_libgamemode() < 0) { | ||
|  | #ifdef GAMEMODE_AUTO
 | ||
|  | 		fprintf(stderr, "gamemodeauto: %s\n", gamemode_error_string()); | ||
|  | #endif
 | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	/* Assert for static analyser that the function is not NULL */ | ||
|  | 	assert(REAL_internal_gamemode_request_start != NULL); | ||
|  | 
 | ||
|  | 	if (REAL_internal_gamemode_request_start() < 0) { | ||
|  | #ifdef GAMEMODE_AUTO
 | ||
|  | 		fprintf(stderr, "gamemodeauto: %s\n", gamemode_error_string()); | ||
|  | #endif
 | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	return 0; | ||
|  | } | ||
|  | 
 | ||
|  | /* Redirect to the real libgamemode */ | ||
|  | #ifdef GAMEMODE_AUTO
 | ||
|  | __attribute__((destructor)) | ||
|  | #else
 | ||
|  | __attribute__((always_inline)) static inline | ||
|  | #endif
 | ||
|  | int gamemode_request_end(void) | ||
|  | { | ||
|  | 	/* Need to load gamemode */ | ||
|  | 	if (internal_load_libgamemode() < 0) { | ||
|  | #ifdef GAMEMODE_AUTO
 | ||
|  | 		fprintf(stderr, "gamemodeauto: %s\n", gamemode_error_string()); | ||
|  | #endif
 | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	/* Assert for static analyser that the function is not NULL */ | ||
|  | 	assert(REAL_internal_gamemode_request_end != NULL); | ||
|  | 
 | ||
|  | 	if (REAL_internal_gamemode_request_end() < 0) { | ||
|  | #ifdef GAMEMODE_AUTO
 | ||
|  | 		fprintf(stderr, "gamemodeauto: %s\n", gamemode_error_string()); | ||
|  | #endif
 | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	return 0; | ||
|  | } | ||
|  | 
 | ||
|  | /* Redirect to the real libgamemode */ | ||
|  | __attribute__((always_inline)) static inline int gamemode_query_status(void) | ||
|  | { | ||
|  | 	/* Need to load gamemode */ | ||
|  | 	if (internal_load_libgamemode() < 0) { | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	if (REAL_internal_gamemode_query_status == NULL) { | ||
|  | 		snprintf(internal_gamemode_client_error_string, | ||
|  | 		         sizeof(internal_gamemode_client_error_string), | ||
|  | 		         "gamemode_query_status missing (older host?)"); | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	return REAL_internal_gamemode_query_status(); | ||
|  | } | ||
|  | 
 | ||
|  | /* Redirect to the real libgamemode */ | ||
|  | __attribute__((always_inline)) static inline int gamemode_request_start_for(pid_t pid) | ||
|  | { | ||
|  | 	/* Need to load gamemode */ | ||
|  | 	if (internal_load_libgamemode() < 0) { | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	if (REAL_internal_gamemode_request_start_for == NULL) { | ||
|  | 		snprintf(internal_gamemode_client_error_string, | ||
|  | 		         sizeof(internal_gamemode_client_error_string), | ||
|  | 		         "gamemode_request_start_for missing (older host?)"); | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	return REAL_internal_gamemode_request_start_for(pid); | ||
|  | } | ||
|  | 
 | ||
|  | /* Redirect to the real libgamemode */ | ||
|  | __attribute__((always_inline)) static inline int gamemode_request_end_for(pid_t pid) | ||
|  | { | ||
|  | 	/* Need to load gamemode */ | ||
|  | 	if (internal_load_libgamemode() < 0) { | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	if (REAL_internal_gamemode_request_end_for == NULL) { | ||
|  | 		snprintf(internal_gamemode_client_error_string, | ||
|  | 		         sizeof(internal_gamemode_client_error_string), | ||
|  | 		         "gamemode_request_end_for missing (older host?)"); | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	return REAL_internal_gamemode_request_end_for(pid); | ||
|  | } | ||
|  | 
 | ||
|  | /* Redirect to the real libgamemode */ | ||
|  | __attribute__((always_inline)) static inline int gamemode_query_status_for(pid_t pid) | ||
|  | { | ||
|  | 	/* Need to load gamemode */ | ||
|  | 	if (internal_load_libgamemode() < 0) { | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	if (REAL_internal_gamemode_query_status_for == NULL) { | ||
|  | 		snprintf(internal_gamemode_client_error_string, | ||
|  | 		         sizeof(internal_gamemode_client_error_string), | ||
|  | 		         "gamemode_query_status_for missing (older host?)"); | ||
|  | 		return -1; | ||
|  | 	} | ||
|  | 
 | ||
|  | 	return REAL_internal_gamemode_query_status_for(pid); | ||
|  | } | ||
|  | 
 | ||
|  | #endif // CLIENT_GAMEMODE_H
 |