1/*
2 *
3 * Copyright (c) 2018 Google Inc.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 *     http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19#include "dlopen_fuchsia.h"
20
21#include <fcntl.h>
22#include <fuchsia/vulkan/loader/c/fidl.h>
23#include <lib/fdio/io.h>
24#include <lib/fdio/directory.h>
25#include <stdio.h>
26#include <string.h>
27#include <threads.h>
28#include <zircon/dlfcn.h>
29#include <zircon/syscalls.h>
30
31static char g_error[128] = {};
32
33const char *dlerror_fuchsia(void) { return g_error; }
34
35static zx_handle_t vulkan_loader_svc = ZX_HANDLE_INVALID;
36void connect_to_vulkan_loader_svc(void) {
37    zx_handle_t svc1, svc2;
38    if (zx_channel_create(0, &svc1, &svc2) != ZX_OK) return;
39
40    if (fdio_service_connect("/svc/" fuchsia_vulkan_loader_Loader_Name, svc1) != ZX_OK) {
41        zx_handle_close(svc2);
42        return;
43    }
44
45    vulkan_loader_svc = svc2;
46}
47
48static once_flag svc_connect_once_flag = ONCE_FLAG_INIT;
49
50void *dlopen_fuchsia(const char *name, int mode, bool driver) {
51    // First try to just dlopen() from our own namespace. This will succeed for
52    // any layers that are packaged with the application, but will fail for
53    // client drivers loaded from the system.
54    void *result;
55    if (!driver) {
56        result = dlopen(name, mode);
57        if (result != NULL) return result;
58    }
59
60    // If we couldn't find the library in our own namespace, connect to the
61    // loader service to request this library.
62    call_once(&svc_connect_once_flag, connect_to_vulkan_loader_svc);
63
64    if (vulkan_loader_svc == ZX_HANDLE_INVALID) {
65        snprintf(g_error, sizeof(g_error), "libvulkan.so:dlopen_fuchsia: no connection to loader svc\n");
66        return NULL;
67    }
68
69    zx_handle_t vmo = ZX_HANDLE_INVALID;
70    zx_status_t st = fuchsia_vulkan_loader_LoaderGet(vulkan_loader_svc, name, strlen(name), &vmo);
71    if (st != ZX_OK) {
72        snprintf(g_error, sizeof(g_error), "libvulkan.so:dlopen_fuchsia: Get() failed: %d\n", st);
73        return NULL;
74    }
75
76    if (vmo == ZX_HANDLE_INVALID) {
77        snprintf(g_error, sizeof(g_error), "libvulkan.so:dlopen_fuchsia: Get() returned invalid vmo\n");
78        return NULL;
79    }
80
81    result = dlopen_vmo(vmo, mode);
82    zx_handle_close(vmo);
83    if (!result) {
84        snprintf(g_error, sizeof(g_error), "%s", dlerror());
85    }
86    return result;
87}
88