Black Mesa: add launcher

Black Mesa/bms.c

@@ -0,0 +1,133 @@
+// gcc -m32 -Wall -Wextra -O3 bms.c -o bms_linux_new -ldl -s -Wl,-rpath,'$ORIGIN/bin'
+// setting the RPATH to '$ORIGIN/bin' makes it possible to start the game without "bms.sh"
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <libgen.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifndef __cplusplus
+typedef char bool;
+#define false 0
+#define true  1
+#endif
+
+int main(int argc, char **argv)
+{
+  char self[PATH_MAX] = {0};
+  char *argv_copy[argc];
+  void *handle;
+  char *error;
+  bool (*pSteamAPI_IsSteamRunning) (void);
+  int (*pLauncherMain) (int, char**);
+
+
+  /* change the current working directory to the exe's path */
+
+  ssize_t ssize = readlink("/proc/self/exe", self, PATH_MAX);
+
+  if (ssize < 1) {
+    fprintf(stderr, "error: readlink() failed; unable to resolve /proc/self/exe\n");
+    return 1;
+  }
+
+  char *copy = strdup(self);
+  char *dir = dirname(copy);
+
+  if (chdir(dir) != 0) {
+    fprintf(stderr, "error: chdir() failed; unable to move into the directory `%s'\n", dir);
+    free(copy);
+    return 1;
+  }
+  free(copy);
+
+
+  /* rename bin/libstdc++.so.6 to only use the system C++ library */
+
+  const char *lib = "bin/libstdc++.so.6";
+  const char *dest = "bin/libstdc++.so.6.old";
+
+  if (access(lib, F_OK) == 0) {
+    printf("renaming `%s' to `%s'\n", lib, dest);
+    if (rename(lib, dest) == -1) {
+      int errsv = errno;
+      fprintf(stderr, "error: moving `%s' failed: %s\n", strerror(errsv), dest);
+      //return 1;
+    }
+  }
+
+
+  /* check for running Steam instance; starting the game without Steam
+   * running will result in a segmentation fault */
+
+  handle = dlopen("./bin/libsteam_api.so", RTLD_LAZY);
+
+  if (!handle) {
+    fprintf(stderr, "error: %s\n", dlerror());
+    return 1;
+  }
+
+  dlerror();
+  *(void **) (&pSteamAPI_IsSteamRunning) = dlsym(handle, "SteamAPI_IsSteamRunning");
+  error = dlerror();
+
+  if (error) {
+    fprintf(stderr, "error: %s\n", error);
+    dlclose(handle);
+    return 1;
+  }
+
+  if (pSteamAPI_IsSteamRunning() == false) {
+    fprintf(stderr, "error: SteamAPI_IsSteamRunning() failed; unable to locate a running instance of Steam\n");
+    dlclose(handle);
+    return 1;
+  }
+
+  dlclose(handle);
+
+
+  /* dlopen() the launcher */
+
+  handle = dlopen("./bin/launcher.so", RTLD_LAZY);
+
+  if (!handle) {
+    fprintf(stderr, "error: %s\n", dlerror());
+    return 1;
+  }
+
+  dlerror();
+  *(void **) (&pLauncherMain) = dlsym(handle, "LauncherMain");
+  error = dlerror();
+
+  if (error) {
+    fprintf(stderr, "error: %s\n", error);
+    dlclose(handle);
+    return 1;
+  }
+
+
+  /* launch game with argv[0] set to the resolved exe path;
+   * otherwise the game's resources won't be loaded correctly
+   * when starting the game from another path */
+
+  argv_copy[0] = strdup(self);
+
+  for (int i = 1; i < argc; i++) {
+    argv_copy[i] = strdup(argv[i]);
+  }
+  argv_copy[argc] = '\0';
+
+  int rv = pLauncherMain(argc, argv_copy);
+  dlclose(handle);
+
+  for (int i = 0; i < argc; i++) {
+    free(argv_copy[i]);
+  }
+
+  return rv;
+}
+