FIXME removal: cleaned up GUI plugin loading and dlopen() abstraction.

icculus · Dec 9, 2006 · dbfaa21 · dbfaa21
1 parent 09dfd3b
commit dbfaa21
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Showing 4 changed files with 93 additions and 48 deletions.
diff --git a/fileio.c b/fileio.c
@@ -1,3 +1,6 @@
+#include <sys/stat.h>  // !!! FIXME: unix dependency for stat().
+#include <limits.h>  // !!! FIXME: unix dependency for realpath().
+
 #include "fileio.h"
 #include "platform.h"
 

diff --git a/gui.c b/gui.c
@@ -8,7 +8,6 @@
 
 typedef struct S_PLUGINLIST
 {
-    char *filename;
     void *lib;
     const MojoGui *gui;
     MojoGuiPluginPriority priority;
@@ -83,16 +82,12 @@ static void deleteGuiPlugin(PluginList *plugin)
             plugin->gui->deinit();
         if (plugin->lib)
             MojoPlatform_dlclose(plugin->lib);
-        if (plugin->filename)
-            MojoPlatform_unlink(plugin->filename);
-        free(plugin->filename);
         free(plugin);
     } // if
 } // deleteGuiPlugin
 
 
-static boolean tryGuiPlugin(PluginList *plugins, const char *fname,
-                            MojoGuiEntryPoint entry)
+static boolean tryGuiPlugin(PluginList *plugins, MojoGuiEntryPoint entry)
 {
     boolean retval = false;
     const MojoGui *gui = entry(MOJOGUI_INTERFACE_REVISION, &GEntryPoints);
@@ -102,7 +97,6 @@ static boolean tryGuiPlugin(PluginList *plugins, const char *fname,
         plug->lib = NULL;
         plug->gui = gui;
         plug->priority = calcGuiPriority(gui);
-        plug->filename = ((fname != NULL) ? xstrdup(fname) : NULL);
         plug->next = plugins->next;
         plugins->next = plug;
         retval = true;
@@ -116,52 +110,37 @@ static void loadStaticGuiPlugins(PluginList *plugins)
 {
     int i;
     for (i = 0; staticGui[i] != NULL; i++)
-        tryGuiPlugin(plugins, NULL, staticGui[i]);
+        tryGuiPlugin(plugins, staticGui[i]);
 } // loadStaticGuiPlugins
 
 
 static boolean loadDynamicGuiPlugin(PluginList *plugins, MojoArchive *ar)
 {
-    char fname[128] = { 0 };
+    boolean rc = false;
     void *lib = NULL;
-    boolean rc;
     MojoInput *io = ar->openCurrentEntry(ar);
-    if (io == NULL)
-        return false;
-
-    STUBBED("Don't copy if it's a physical file already?");
-
-    STUBBED("Filename creation has to change");
+    if (io != NULL)
     {
-        struct timeval tv;
-        gettimeofday(&tv, NULL);
-        snprintf(fname, sizeof (fname), "/tmp/mojosetup-gui-%ld.so", tv.tv_sec);
-    }
-
-    rc = mojoInputToPhysicalFile(io, fname);
-    io->close(io);
+        const uint32 imglen = (uint32) io->length(io);
+        uint8 *img = (uint8 *) xmalloc(imglen);
+        const uint32 br = io->read(io, img, imglen);
+        io->close(io);
+        if (br == imglen)
+            lib = MojoPlatform_dlopen(img, imglen);
+        free(img);
+    } // if
 
-    if (rc)
+    if (lib != NULL)
     {
-        rc = false;
-        lib = MojoPlatform_dlopen(fname);
-        if (lib != NULL)
+        void *addr = MojoPlatform_dlsym(lib, MOJOGUI_ENTRY_POINT_STR);
+        MojoGuiEntryPoint entry = (MojoGuiEntryPoint) addr;
+        if (entry != NULL)
         {
-            void *addr = MojoPlatform_dlsym(lib, MOJOGUI_ENTRY_POINT_STR);
-            MojoGuiEntryPoint entry = (MojoGuiEntryPoint) addr;
-            if (entry != NULL)
-                rc = tryGuiPlugin(plugins, fname, entry);
+            if ((rc = tryGuiPlugin(plugins, entry)) == false)
+                MojoPlatform_dlclose(lib);
         } // if
     } // if
 
-    if (!rc)
-    {
-        if (lib != NULL)
-            MojoPlatform_dlclose(lib);
-        if (fname[0])
-            MojoPlatform_unlink(fname);
-    } // if
-
     return rc;
 } // loadDynamicGuiPlugin
 

diff --git a/platform.h b/platform.h
@@ -26,8 +26,13 @@ void MojoPlatform_die(void);
 //  on failure.
 boolean MojoPlatform_unlink(const char *fname);
 
-// Wrappers for Unix dlopen/dlsym/dlclose ...
-void *MojoPlatform_dlopen(const char *fname);
+// Wrappers for Unix dlopen/dlsym/dlclose, sort of. Instead of a filename,
+//  these take a memory buffer for the library. If you can't load this
+//  directly in RAM, the platform should write it to a temporary file first,
+//  and deal with cleanup in MojoPlatform_dlclose(). The memory buffer must be
+//  dereferenced in MojoPlatform_dlopen(), as the caller may free() it upon
+//  return. Everything else works like the usual Unix calls.
+void *MojoPlatform_dlopen(const uint8 *img, size_t len);
 void *MojoPlatform_dlsym(void *lib, const char *sym);
 void MojoPlatform_dlclose(void *lib);
 
@@ -48,7 +53,7 @@ boolean MojoPlatform_osVersion(char *buf, size_t len);
 #elif PLATFORM_UNIX
 #define PLATFORM_NAME "unix"
 #else
-#error Unknown processor architecture.
+#error Unknown platform.
 #endif
 
 // Basic architecture detection.

diff --git a/platform/unix.c b/platform/unix.c
@@ -4,12 +4,12 @@
 #undef false
 #endif
 
-#include <time.h>
 #include <sys/time.h>
-#include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/param.h>
+#include <time.h>
+#include <unistd.h>
 #include <dlfcn.h>
 
 #include "../platform.h"
@@ -206,12 +206,70 @@ boolean MojoPlatform_unlink(const char *fname)
 #define USE_LEGACY_MACOSX_DLOPEN 1
 #endif
 
-void *MojoPlatform_dlopen(const char *fname)
+static boolean testTmpDir(const char *dname, char *buf,
+                          size_t len, const char *tmpl)
 {
-    #if USE_LEGACY_MACOSX_DLOPEN
-    #error !!! FIXME Write me.
+    boolean retval = false;
+    if ( (dname != NULL) && (access(dname, R_OK | W_OK | X_OK) == 0) )
+    {
+        struct stat statbuf;
+        if ( (stat(dname, &statbuf) == 0) && (S_ISDIR(statbuf.st_mode)) )
+        {
+            const size_t rc = snprintf(buf, len, "%s/%s", dname, tmpl);
+            if (rc < len)
+                retval = true;
+        } // if
+    } // if
+
+    return retval;
+} // testTmpDir
+
+
+static inline boolean chooseTempFile(char *fname, size_t len, const char *tmpl)
+{
+    #ifndef P_tmpdir  // glibc defines this, maybe others.
+    #define P_tmpdir NULL
     #endif
-    return dlopen(fname, RTLD_NOW | RTLD_GLOBAL);
+
+    if (!testTmpDir(getenv("TMPDIR"), fname, len, tmpl))
+    {
+        if (!testTmpDir(P_tmpdir, fname, len, tmpl))
+        {
+            if (!testTmpDir("/tmp", fname, len, tmpl))
+                return false;
+        } // if
+    } // if
+
+    return true;
+} // chooseTempFile
+
+
+void *MojoPlatform_dlopen(const uint8 *img, size_t len)
+{
+    // Write the image to a temporary file, dlopen() it, and delete it
+    //  immediately. The inode will be kept around by the Unix kernel until
+    //  we either dlclose() it or the process terminates, but we don't have
+    //  to worry about polluting the /tmp directory or cleaning this up later.
+
+    void *retval = NULL;
+    char fname[PATH_MAX];
+    if (chooseTempFile(fname, sizeof (fname), "mojosetup-gui-plugin-XXXXXX"))
+    {
+        const int fd = mkstemp(fname);
+        if (fd != -1)
+        {
+            const size_t bw = write(fd, img, len);
+            const int rc = close(fd);
+            #if USE_LEGACY_MACOSX_DLOPEN
+            #error !!! FIXME Write me.
+            #endif
+            if ((bw == len) && (rc != -1))
+                retval = dlopen(fname, RTLD_NOW | RTLD_GLOBAL);
+            unlink(fname);
+        } // if
+    } // if
+
+    return retval;
 } // MojoPlatform_dlopen