/* Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include "httpd.h"

#include "http_config.h"

#include "http_core.h"

#include "http_log.h"

#include "http_request.h"

#include "apr_strings.h"

#include "unixd.h"

#include "mpm_common.h"

#include "mod_suexec.h"

module AP_MODULE_DECLARE_DATA suexec_module;

/*

 * Create a configuration specific to this module for a server or directory

 * location, and fill it with the default settings.

 */

static void *mkconfig(apr_pool_t *p)

{

    suexec_config_t *cfg = apr_palloc(p, sizeof(suexec_config_t));

    cfg->active = 0;

    return cfg;

}

/*

 * Respond to a callback to create configuration record for a server or

 * vhost environment.

 */

static void *create_mconfig_for_server(apr_pool_t *p, server_rec *s)

{

    return mkconfig(p);

}

/*

 * Respond to a callback to create a config record for a specific directory.

 */

static void *create_mconfig_for_directory(apr_pool_t *p, char *dir)

{

    return mkconfig(p);

}

static const char *set_suexec_ugid(cmd_parms *cmd, void *mconfig,

                                   const char *uid, const char *gid)

{

    suexec_config_t *cfg = (suexec_config_t *) mconfig;

    const char *err = ap_check_cmd_context(cmd, NOT_IN_DIR_CONTEXT);

    if (err != NULL) {

        return err;

    }

    if (!ap_unixd_config.suexec_enabled) {

        return apr_pstrcat(cmd->pool, "SuexecUserGroup configured, but "

                           "suEXEC is disabled: ",

                           ap_unixd_config.suexec_disabled_reason, NULL);

    }

    cfg->ugid.uid = ap_uname2id(uid);

    cfg->ugid.gid = ap_gname2id(gid);

    cfg->ugid.userdir = 0;

    cfg->active = 1;

    return NULL;

}

static ap_unix_identity_t *get_suexec_id_doer(const request_rec *r)

{

    suexec_config_t *cfg =

    (suexec_config_t *) ap_get_module_config(r->per_dir_config, &suexec_module);

    return cfg->active ? &cfg->ugid : NULL;

}

#define SUEXEC_POST_CONFIG_USERDATA "suexec_post_config_userdata"

static int suexec_post_config(apr_pool_t *p, apr_pool_t *plog,

                              apr_pool_t *ptemp, server_rec *s)

{

    void *reported;

    apr_pool_userdata_get(&reported, SUEXEC_POST_CONFIG_USERDATA,

                          s->process->pool);

    if ((reported == NULL) && ap_unixd_config.suexec_enabled) {

        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, s, APLOGNO(01232)

                     "suEXEC mechanism enabled (wrapper: %s)", SUEXEC_BIN);

        apr_pool_userdata_set((void *)1, SUEXEC_POST_CONFIG_USERDATA,

                              apr_pool_cleanup_null, s->process->pool);

    }

    return OK;

}

#undef SUEXEC_POST_CONFIG_USERDATA

/*

 * Define the directives specific to this module.  This structure is referenced

 * later by the 'module' structure.

 */

static const command_rec suexec_cmds[] =

{

    /* XXX - Another important reason not to allow this in .htaccess is that

     * the ap_[ug]name2id() is not thread-safe */

    AP_INIT_TAKE2("SuexecUserGroup", set_suexec_ugid, NULL, RSRC_CONF,

      "User and group for spawned processes"),

    { NULL }

};

static void suexec_hooks(apr_pool_t *p)

{

    ap_hook_get_suexec_identity(get_suexec_id_doer,NULL,NULL,APR_HOOK_MIDDLE);

    ap_hook_post_config(suexec_post_config,NULL,NULL,APR_HOOK_MIDDLE);

}

AP_DECLARE_MODULE(suexec) =

{

    STANDARD20_MODULE_STUFF,

    create_mconfig_for_directory,   /* create per-dir config */

    NULL,                       /* merge per-dir config */

    create_mconfig_for_server,  /* server config */

    NULL,                       /* merge server config */

    suexec_cmds,                /* command table */

    suexec_hooks                /* register hooks */

};