summaryrefslogtreecommitdiff
path: root/shared/nm-utils/nm-vpn-plugin-utils.c
blob: 99ae5d013bf56b17e0fca095c51b00e47bff2e27 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
// SPDX-License-Identifier: LGPL-2.1+
/*
 * Copyright (C) 2016, 2018 Red Hat, Inc.
 */

#include "nm-default.h"

#include "nm-vpn-plugin-utils.h"

#include <dlfcn.h>

/*****************************************************************************/

NMVpnEditor *
nm_vpn_plugin_utils_load_editor(const char *                  module_name,
                                const char *                  factory_name,
                                NMVpnPluginUtilsEditorFactory editor_factory,
                                NMVpnEditorPlugin *           editor_plugin,
                                NMConnection *                connection,
                                gpointer                      user_data,
                                GError **                     error)

{
    static struct {
        gpointer factory;
        void *   dl_module;
        char *   module_name;
        char *   factory_name;
    } cached = {0};
    NMVpnEditor * editor;
    gs_free char *module_path = NULL;
    gs_free char *dirname     = NULL;
    Dl_info       plugin_info;

    g_return_val_if_fail(module_name, NULL);
    g_return_val_if_fail(factory_name && factory_name[0], NULL);
    g_return_val_if_fail(editor_factory, NULL);
    g_return_val_if_fail(NM_IS_VPN_EDITOR_PLUGIN(editor_plugin), NULL);
    g_return_val_if_fail(NM_IS_CONNECTION(connection), NULL);
    g_return_val_if_fail(!error || !*error, NULL);

    if (!g_path_is_absolute(module_name)) {
        /*
		 * Load an editor from the same directory this plugin is in.
		 * Ideally, we'd get our .so name from the NMVpnEditorPlugin if it
		 * would just have a property with it...
		 */
        if (!dladdr(nm_vpn_plugin_utils_load_editor, &plugin_info)) {
            /* Really a "can not happen" scenario. */
            g_set_error(error,
                        NM_VPN_PLUGIN_ERROR,
                        NM_VPN_PLUGIN_ERROR_FAILED,
                        _("unable to get editor plugin name: %s"),
                        dlerror());
        }

        dirname     = g_path_get_dirname(plugin_info.dli_fname);
        module_path = g_build_filename(dirname, module_name, NULL);
    } else {
        module_path = g_strdup(module_name);
    }

    /* we really expect this function to be called with unchanging @module_name
	 * and @factory_name. And we only want to load the module once, hence it would
	 * be more complicated to accept changing @module_name/@factory_name arguments.
	 *
	 * The reason for only loading once is that due to glib types, we cannot create a
	 * certain type-name more then once, so loading the same module or another version
	 * of the same module will fail horribly as both try to create a GType with the same
	 * name.
	 *
	 * Only support loading once, any future calls will reuse the handle. To simplify
	 * that, we enforce that the @factory_name and @module_name is the same. */
    if (cached.factory) {
        g_return_val_if_fail(cached.dl_module, NULL);
        g_return_val_if_fail(cached.factory_name && nm_streq0(cached.factory_name, factory_name),
                             NULL);
        g_return_val_if_fail(cached.module_name && nm_streq0(cached.module_name, module_name),
                             NULL);
    } else {
        gpointer factory;
        void *   dl_module;

        dl_module = dlopen(module_path, RTLD_LAZY | RTLD_LOCAL);
        if (!dl_module) {
            if (!g_file_test(module_path, G_FILE_TEST_EXISTS)) {
                g_set_error(error,
                            G_FILE_ERROR,
                            G_FILE_ERROR_NOENT,
                            _("missing plugin file \"%s\""),
                            module_path);
                return NULL;
            }
            g_set_error(error,
                        NM_VPN_PLUGIN_ERROR,
                        NM_VPN_PLUGIN_ERROR_FAILED,
                        _("cannot load editor plugin: %s"),
                        dlerror());
            return NULL;
        }

        factory = dlsym(dl_module, factory_name);
        if (!factory) {
            g_set_error(error,
                        NM_VPN_PLUGIN_ERROR,
                        NM_VPN_PLUGIN_ERROR_FAILED,
                        _("cannot load factory %s from plugin: %s"),
                        factory_name,
                        dlerror());
            dlclose(dl_module);
            return NULL;
        }

        /* we cannot ever unload the module because it creates glib types, which
		 * cannot be unregistered.
		 *
		 * Thus we just leak the dl_module handle indefinitely. */
        cached.factory      = factory;
        cached.dl_module    = dl_module;
        cached.module_name  = g_strdup(module_name);
        cached.factory_name = g_strdup(factory_name);
    }

    editor = editor_factory(cached.factory, editor_plugin, connection, user_data, error);
    if (!editor) {
        if (error && !*error) {
            g_set_error_literal(error,
                                NM_VPN_PLUGIN_ERROR,
                                NM_VPN_PLUGIN_ERROR_FAILED,
                                _("unknown error creating editor instance"));
            g_return_val_if_reached(NULL);
        }
        return NULL;
    }

    g_return_val_if_fail(NM_IS_VPN_EDITOR(editor), NULL);
    return editor;
}