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 "httpd.h"
18#include "http_config.h"
19#include "http_core.h"
20#include "http_log.h"
21#include "http_request.h"
22#include "apr_strings.h"
23#include "unixd.h"
24#include "mpm_common.h"
25#include "mod_suexec.h"
26
27module AP_MODULE_DECLARE_DATA suexec_module;
28
29/*
30 * Create a configuration specific to this module for a server or directory
31 * location, and fill it with the default settings.
32 */
33static void *mkconfig(apr_pool_t *p)
34{
35    suexec_config_t *cfg = apr_palloc(p, sizeof(suexec_config_t));
36
37    cfg->active = 0;
38    return cfg;
39}
40
41/*
42 * Respond to a callback to create configuration record for a server or
43 * vhost environment.
44 */
45static void *create_mconfig_for_server(apr_pool_t *p, server_rec *s)
46{
47    return mkconfig(p);
48}
49
50/*
51 * Respond to a callback to create a config record for a specific directory.
52 */
53static void *create_mconfig_for_directory(apr_pool_t *p, char *dir)
54{
55    return mkconfig(p);
56}
57
58static const char *set_suexec_ugid(cmd_parms *cmd, void *mconfig,
59                                   const char *uid, const char *gid)
60{
61    suexec_config_t *cfg = (suexec_config_t *) mconfig;
62    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_LOC_FILE);
63
64    if (err != NULL) {
65        return err;
66    }
67
68    if (!ap_unixd_config.suexec_enabled) {
69        return apr_pstrcat(cmd->pool, "SuexecUserGroup configured, but "
70                           "suEXEC is disabled: ",
71                           ap_unixd_config.suexec_disabled_reason, NULL);
72    }
73
74    cfg->ugid.uid = ap_uname2id(uid);
75    cfg->ugid.gid = ap_gname2id(gid);
76    cfg->ugid.userdir = 0;
77    cfg->active = 1;
78
79    return NULL;
80}
81
82static ap_unix_identity_t *get_suexec_id_doer(const request_rec *r)
83{
84    suexec_config_t *cfg =
85    (suexec_config_t *) ap_get_module_config(r->per_dir_config, &suexec_module);
86
87    return cfg->active ? &cfg->ugid : NULL;
88}
89
90#define SUEXEC_POST_CONFIG_USERDATA "suexec_post_config_userdata"
91static int suexec_post_config(apr_pool_t *p, apr_pool_t *plog,
92                              apr_pool_t *ptemp, server_rec *s)
93{
94    void *reported;
95
96    apr_pool_userdata_get(&reported, SUEXEC_POST_CONFIG_USERDATA,
97                          s->process->pool);
98
99    if ((reported == NULL) && ap_unixd_config.suexec_enabled) {
100        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, s, APLOGNO(01232)
101                     "suEXEC mechanism enabled (wrapper: %s)", SUEXEC_BIN);
102
103        apr_pool_userdata_set((void *)1, SUEXEC_POST_CONFIG_USERDATA,
104                              apr_pool_cleanup_null, s->process->pool);
105    }
106
107    return OK;
108}
109#undef SUEXEC_POST_CONFIG_USERDATA
110
111/*
112 * Define the directives specific to this module.  This structure is referenced
113 * later by the 'module' structure.
114 */
115static const command_rec suexec_cmds[] =
116{
117    /* XXX - Another important reason not to allow this in .htaccess is that
118     * the ap_[ug]name2id() is not thread-safe */
119    AP_INIT_TAKE2("SuexecUserGroup", set_suexec_ugid, NULL, RSRC_CONF,
120      "User and group for spawned processes"),
121    { NULL }
122};
123
124static void suexec_hooks(apr_pool_t *p)
125{
126    ap_hook_get_suexec_identity(get_suexec_id_doer,NULL,NULL,APR_HOOK_MIDDLE);
127    ap_hook_post_config(suexec_post_config,NULL,NULL,APR_HOOK_MIDDLE);
128}
129
130AP_DECLARE_MODULE(suexec) =
131{
132    STANDARD20_MODULE_STUFF,
133    create_mconfig_for_directory,   /* create per-dir config */
134    NULL,                       /* merge per-dir config */
135    create_mconfig_for_server,  /* server config */
136    NULL,                       /* merge server config */
137    suexec_cmds,                /* command table */
138    suexec_hooks                /* register hooks */
139};
140