1/*
2 * QEMU Module Infrastructure
3 *
4 * Copyright IBM, Corp. 2009
5 *
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.com>
8 *
9 * This work is licensed under the terms of the GNU GPL, version 2. See
10 * the COPYING file in the top-level directory.
11 *
12 * Contributions after 2012-01-13 are licensed under the terms of the
13 * GNU GPL, version 2 or (at your option) any later version.
14 */
15
16#include "qemu/osdep.h"
17#ifdef CONFIG_MODULES
18#include <gmodule.h>
19#endif
20#include "qemu/queue.h"
21#include "qemu/module.h"
22
23typedef struct ModuleEntry
24{
25 void (*init)(void);
26 QTAILQ_ENTRY(ModuleEntry) node;
27 module_init_type type;
28} ModuleEntry;
29
30typedef QTAILQ_HEAD(, ModuleEntry) ModuleTypeList;
31
32static ModuleTypeList init_type_list[MODULE_INIT_MAX];
33
34static ModuleTypeList dso_init_list;
35
36static void init_lists(void)
37{
38 static int inited;
39 int i;
40
41 if (inited) {
42 return;
43 }
44
45 for (i = 0; i < MODULE_INIT_MAX; i++) {
46 QTAILQ_INIT(&init_type_list[i]);
47 }
48
49 QTAILQ_INIT(&dso_init_list);
50
51 inited = 1;
52}
53
54
55static ModuleTypeList *find_type(module_init_type type)
56{
57 init_lists();
58
59 return &init_type_list[type];
60}
61
62void register_module_init(void (*fn)(void), module_init_type type)
63{
64 ModuleEntry *e;
65 ModuleTypeList *l;
66
67 e = g_malloc0(sizeof(*e));
68 e->init = fn;
69 e->type = type;
70
71 l = find_type(type);
72
73 QTAILQ_INSERT_TAIL(l, e, node);
74}
75
76void register_dso_module_init(void (*fn)(void), module_init_type type)
77{
78 ModuleEntry *e;
79
80 init_lists();
81
82 e = g_malloc0(sizeof(*e));
83 e->init = fn;
84 e->type = type;
85
86 QTAILQ_INSERT_TAIL(&dso_init_list, e, node);
87}
88
89void module_call_init(module_init_type type)
90{
91 ModuleTypeList *l;
92 ModuleEntry *e;
93
94 l = find_type(type);
95
96 QTAILQ_FOREACH(e, l, node) {
97 e->init();
98 }
99}
100
101#ifdef CONFIG_MODULES
102static int module_load_file(const char *fname)
103{
104 GModule *g_module;
105 void (*sym)(void);
106 const char *dsosuf = HOST_DSOSUF;
107 int len = strlen(fname);
108 int suf_len = strlen(dsosuf);
109 ModuleEntry *e, *next;
110 int ret;
111
112 if (len <= suf_len || strcmp(&fname[len - suf_len], dsosuf)) {
113 /* wrong suffix */
114 ret = -EINVAL;
115 goto out;
116 }
117 if (access(fname, F_OK)) {
118 ret = -ENOENT;
119 goto out;
120 }
121
122 assert(QTAILQ_EMPTY(&dso_init_list));
123
124 g_module = g_module_open(fname, G_MODULE_BIND_LAZY | G_MODULE_BIND_LOCAL);
125 if (!g_module) {
126 fprintf(stderr, "Failed to open module: %s\n",
127 g_module_error());
128 ret = -EINVAL;
129 goto out;
130 }
131 if (!g_module_symbol(g_module, DSO_STAMP_FUN_STR, (gpointer *)&sym)) {
132 fprintf(stderr, "Failed to initialize module: %s\n",
133 fname);
134 /* Print some info if this is a QEMU module (but from different build),
135 * this will make debugging user problems easier. */
136 if (g_module_symbol(g_module, "qemu_module_dummy", (gpointer *)&sym)) {
137 fprintf(stderr,
138 "Note: only modules from the same build can be loaded.\n");
139 }
140 g_module_close(g_module);
141 ret = -EINVAL;
142 } else {
143 QTAILQ_FOREACH(e, &dso_init_list, node) {
144 e->init();
145 register_module_init(e->init, e->type);
146 }
147 ret = 0;
148 }
149
150 QTAILQ_FOREACH_SAFE(e, &dso_init_list, node, next) {
151 QTAILQ_REMOVE(&dso_init_list, e, node);
152 g_free(e);
153 }
154out:
155 return ret;
156}
157#endif
158
159bool module_load_one(const char *prefix, const char *lib_name)
160{
161 bool success = false;
162
163#ifdef CONFIG_MODULES
164 char *fname = NULL;
165 char *exec_dir;
166 const char *search_dir;
167 char *dirs[4];
168 char *module_name;
169 int i = 0, n_dirs = 0;
170 int ret;
171 static GHashTable *loaded_modules;
172
173 if (!g_module_supported()) {
174 fprintf(stderr, "Module is not supported by system.\n");
175 return false;
176 }
177
178 if (!loaded_modules) {
179 loaded_modules = g_hash_table_new(g_str_hash, g_str_equal);
180 }
181
182 module_name = g_strdup_printf("%s%s", prefix, lib_name);
183
184 if (!g_hash_table_add(loaded_modules, module_name)) {
185 g_free(module_name);
186 return true;
187 }
188
189 exec_dir = qemu_get_exec_dir();
190 search_dir = getenv("QEMU_MODULE_DIR");
191 if (search_dir != NULL) {
192 dirs[n_dirs++] = g_strdup_printf("%s", search_dir);
193 }
194 dirs[n_dirs++] = g_strdup_printf("%s", CONFIG_QEMU_MODDIR);
195 dirs[n_dirs++] = g_strdup_printf("%s/..", exec_dir ? : "");
196 dirs[n_dirs++] = g_strdup_printf("%s", exec_dir ? : "");
197 assert(n_dirs <= ARRAY_SIZE(dirs));
198
199 g_free(exec_dir);
200 exec_dir = NULL;
201
202 for (i = 0; i < n_dirs; i++) {
203 fname = g_strdup_printf("%s/%s%s",
204 dirs[i], module_name, HOST_DSOSUF);
205 ret = module_load_file(fname);
206 g_free(fname);
207 fname = NULL;
208 /* Try loading until loaded a module file */
209 if (!ret) {
210 success = true;
211 break;
212 }
213 }
214
215 if (!success) {
216 g_hash_table_remove(loaded_modules, module_name);
217 }
218
219 for (i = 0; i < n_dirs; i++) {
220 g_free(dirs[i]);
221 }
222
223#endif
224 return success;
225}
226