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Diffstat (limited to 'libraries/gamemode/include')
| -rw-r--r-- | libraries/gamemode/include/gamemode_client.h | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/libraries/gamemode/include/gamemode_client.h b/libraries/gamemode/include/gamemode_client.h new file mode 100644 index 00000000..b6f7afd4 --- /dev/null +++ b/libraries/gamemode/include/gamemode_client.h @@ -0,0 +1,365 @@ +/* + +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 <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; + } + + 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; + } + + 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; + } + + 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 |