fuchsia/dlopen_fuchsia.cc

/*
 *
 * Copyright (c) 2018 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include "dlopen_fuchsia.h"

#include <fcntl.h>
#include <lib/fdio/directory.h>
#include <lib/fdio/io.h>
#include <stdio.h>
#include <string.h>
#include <threads.h>
#include <zircon/dlfcn.h>
#include <zircon/syscalls.h>

#include "loader_service.h"

static char g_error[128] = {};

const char *dlerror_fuchsia(void) { return g_error; }

void *dlopen_fuchsia(const char *name, int mode, bool driver) {
    // First try to just dlopen() from our own namespace. This will succeed for
    // any layers that are packaged with the application, but will fail for
    // client drivers loaded from the system.
    void *result;
    if (!driver) {
        result = dlopen(name, mode);
        if (result != NULL) return result;
    }

    // If we couldn't find the library in our own namespace, connect to the
    // loader service to request this library.

    auto &loader_svc = get_vulkan_loader_service();
    if (!loader_svc.client_end()) {
        snprintf(g_error, sizeof(g_error), "libvulkan.so:dlopen_fuchsia: no connection to loader svc\n");
        return NULL;
    }

    auto get_result = loader_svc.Get(fidl::StringView::FromExternal(name));
    if (!get_result.ok()) {
        snprintf(g_error, sizeof(g_error), "libvulkan.so:dlopen_fuchsia: Get() failed: %d\n", get_result.status());
        return NULL;
    }

    if (!get_result->lib) {
        snprintf(g_error, sizeof(g_error), "libvulkan.so:dlopen_fuchsia: Get() returned invalid vmo\n");
        return NULL;
    }

    result = dlopen_vmo(get_result->lib.get(), mode);
    if (!result) {
        snprintf(g_error, sizeof(g_error), "%s", dlerror());
    }
    return result;
}