1/* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements.  See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License.  You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <ctype.h>
18#include <stdio.h>
19
20#include "apu_config.h"
21#include "apu.h"
22
23#include "apr_pools.h"
24#include "apr_tables.h"
25#include "apr_dso.h"
26#include "apr_strings.h"
27#include "apr_hash.h"
28#include "apr_file_io.h"
29#include "apr_env.h"
30#include "apr_atomic.h"
31
32#include "apu_internal.h"
33#include "apu_version.h"
34
35#if APU_DSO_BUILD
36
37#if APR_HAS_THREADS
38static apr_thread_mutex_t* mutex = NULL;
39#endif
40static apr_hash_t *dsos = NULL;
41static apr_uint32_t initialised = 0, in_init = 1;
42
43#if APR_HAS_THREADS
44apr_status_t apu_dso_mutex_lock()
45{
46    return apr_thread_mutex_lock(mutex);
47}
48apr_status_t apu_dso_mutex_unlock()
49{
50    return apr_thread_mutex_unlock(mutex);
51}
52#else
53apr_status_t apu_dso_mutex_lock() {
54    return APR_SUCCESS;
55}
56apr_status_t apu_dso_mutex_unlock() {
57    return APR_SUCCESS;
58}
59#endif
60
61static apr_status_t apu_dso_term(void *ptr)
62{
63    /* set statics to NULL so init can work again */
64    dsos = NULL;
65#if APR_HAS_THREADS
66    mutex = NULL;
67#endif
68
69    /* Everything else we need is handled by cleanups registered
70     * when we created mutexes and loaded DSOs
71     */
72    return APR_SUCCESS;
73}
74
75apr_status_t apu_dso_init(apr_pool_t *pool)
76{
77    apr_status_t ret = APR_SUCCESS;
78    apr_pool_t *global;
79    apr_pool_t *parent;
80
81    if (apr_atomic_inc32(&initialised)) {
82        apr_atomic_set32(&initialised, 1); /* prevent wrap-around */
83
84        while (apr_atomic_read32(&in_init)) /* wait until we get fully inited */
85            ;
86
87        return APR_SUCCESS;
88    }
89
90    /* Top level pool scope, need process-scope lifetime */
91    for (parent = global = pool; parent; parent = apr_pool_parent_get(global))
92        global = parent;
93
94    dsos = apr_hash_make(global);
95
96#if APR_HAS_THREADS
97    ret = apr_thread_mutex_create(&mutex, APR_THREAD_MUTEX_DEFAULT, global);
98    /* This already registers a pool cleanup */
99#endif
100
101    apr_pool_cleanup_register(global, NULL, apu_dso_term,
102                              apr_pool_cleanup_null);
103
104    apr_atomic_dec32(&in_init);
105
106    return ret;
107}
108
109apr_status_t apu_dso_load(apr_dso_handle_t **dlhandleptr,
110                          apr_dso_handle_sym_t *dsoptr,
111                          const char *module,
112                          const char *modsym,
113                          apr_pool_t *pool)
114{
115    apr_dso_handle_t *dlhandle = NULL;
116    char *pathlist;
117    char path[APR_PATH_MAX + 1];
118    apr_array_header_t *paths;
119    apr_pool_t *global;
120    apr_status_t rv = APR_EDSOOPEN;
121    char *eos = NULL;
122    int i;
123
124    *dsoptr = apr_hash_get(dsos, module, APR_HASH_KEY_STRING);
125    if (*dsoptr) {
126        return APR_EINIT;
127    }
128
129    /* The driver DSO must have exactly the same lifetime as the
130     * drivers hash table; ignore the passed-in pool */
131    global = apr_hash_pool_get(dsos);
132
133    /* Retrieve our path search list or prepare for a single search */
134    if ((apr_env_get(&pathlist, APR_DSOPATH, pool) != APR_SUCCESS)
135          || (apr_filepath_list_split(&paths, pathlist, pool) != APR_SUCCESS))
136        paths = apr_array_make(pool, 1, sizeof(char*));
137
138#if defined(APU_DSO_LIBDIR)
139    /* Always search our prefix path, but on some platforms such as
140     * win32 this may be left undefined
141     */
142    (*((char **)apr_array_push(paths))) = APU_DSO_LIBDIR;
143#endif
144
145    for (i = 0; i < paths->nelts; ++i)
146    {
147#if defined(WIN32)
148        /* Use win32 dso search semantics and attempt to
149         * load the relative lib on the first pass.
150         */
151        if (!eos) {
152            eos = path;
153            --i;
154        }
155        else
156#endif
157        {
158            eos = apr_cpystrn(path, ((char**)paths->elts)[i], sizeof(path));
159            if ((eos > path) && (eos - path < sizeof(path) - 1))
160                *(eos++) = '/';
161        }
162        apr_cpystrn(eos, module, sizeof(path) - (eos - path));
163
164        rv = apr_dso_load(&dlhandle, path, global);
165        if (dlhandleptr) {
166            *dlhandleptr = dlhandle;
167        }
168        if (rv == APR_SUCCESS) { /* APR_EDSOOPEN */
169            break;
170        }
171#if defined(APU_DSO_LIBDIR)
172        else if (i < paths->nelts - 1) {
173#else
174        else {   /* No APU_DSO_LIBDIR to skip */
175#endif
176             /* try with apr-util-APU_MAJOR_VERSION appended */
177            eos = apr_cpystrn(eos,
178                              "apr-util-" APU_STRINGIFY(APU_MAJOR_VERSION) "/",
179                              sizeof(path) - (eos - path));
180
181            apr_cpystrn(eos, module, sizeof(path) - (eos - path));
182
183            rv = apr_dso_load(&dlhandle, path, global);
184            if (dlhandleptr) {
185                *dlhandleptr = dlhandle;
186            }
187            if (rv == APR_SUCCESS) { /* APR_EDSOOPEN */
188                break;
189            }
190        }
191    }
192
193    if (rv != APR_SUCCESS) /* APR_ESYMNOTFOUND */
194        return rv;
195
196    rv = apr_dso_sym(dsoptr, dlhandle, modsym);
197    if (rv != APR_SUCCESS) { /* APR_ESYMNOTFOUND */
198        apr_dso_unload(dlhandle);
199    }
200    else {
201        module = apr_pstrdup(global, module);
202        apr_hash_set(dsos, module, APR_HASH_KEY_STRING, *dsoptr);
203    }
204    return rv;
205}
206
207#endif /* APU_DSO_BUILD */
208
209