/* 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_log.h"

#include "http_config.h"

#include "ap_provider.h"

#include "http_request.h"

#include "http_protocol.h"

#include "http_core.h"

#include "apr_dbd.h"

#include "mod_dbd.h"

#include "apr_strings.h"

#include "mod_authz_dbd.h"

#include "mod_auth.h"

module AP_MODULE_DECLARE_DATA authz_dbd_module;

/* Export a hook for modules that manage clientside sessions

 * (e.g. mod_auth_cookie)

 * to deal with those when we successfully login/logout at the server

 *

 * XXX: WHY would this be specific to dbd_authz?  Why wouldn't we track

 * this across all authz user providers in a lower level mod, such as

 * mod_auth_basic/digest?

 */

APR_IMPLEMENT_OPTIONAL_HOOK_RUN_ALL(authz_dbd, AUTHZ_DBD, int, client_login,

                            (request_rec *r, int code, const char *action),

                            (r, code, action), OK, DECLINED)

typedef struct {

    const char *query;

    const char *redir_query;

    int redirect;

} authz_dbd_cfg ;

static ap_dbd_t *(*dbd_handle)(request_rec*) = NULL;

static void (*dbd_prepare)(server_rec*, const char*, const char*) = NULL;

static const char *const noerror = "???";

static void *authz_dbd_cr_cfg(apr_pool_t *pool, char *dummy)

{

    authz_dbd_cfg *ret = apr_pcalloc(pool, sizeof(authz_dbd_cfg));

    ret->redirect = -1;

    return ret;

}

static void *authz_dbd_merge_cfg(apr_pool_t *pool, void *BASE, void *ADD)

{

    authz_dbd_cfg *base = BASE;

    authz_dbd_cfg *add = ADD;

    authz_dbd_cfg *ret = apr_palloc(pool, sizeof(authz_dbd_cfg));

    ret->query = (add->query == NULL) ? base->query : add->query;

    ret->redir_query = (add->redir_query == NULL)

                            ? base->redir_query : add->redir_query;

    ret->redirect = (add->redirect == -1) ? base->redirect : add->redirect;

    return ret;

}

static const char *authz_dbd_prepare(cmd_parms *cmd, void *cfg,

                                     const char *query)

{

    static unsigned int label_num = 0;

    char *label;

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

    if (err)

        return err;

    if (dbd_prepare == NULL) {

        dbd_prepare = APR_RETRIEVE_OPTIONAL_FN(ap_dbd_prepare);

        if (dbd_prepare == NULL) {

            return "You must load mod_dbd to enable AuthzDBD functions";

        }

        dbd_handle = APR_RETRIEVE_OPTIONAL_FN(ap_dbd_acquire);

    }

    label = apr_psprintf(cmd->pool, "authz_dbd_%d", ++label_num);

    dbd_prepare(cmd->server, query, label);

    /* save the label here for our own use */

    return ap_set_string_slot(cmd, cfg, label);

}

static const command_rec authz_dbd_cmds[] = {

    AP_INIT_FLAG("AuthzDBDLoginToReferer", ap_set_flag_slot,

                 (void*)APR_OFFSETOF(authz_dbd_cfg, redirect), ACCESS_CONF,

                 "Whether to redirect to referer on successful login"),

    AP_INIT_TAKE1("AuthzDBDQuery", authz_dbd_prepare,

                  (void*)APR_OFFSETOF(authz_dbd_cfg, query), ACCESS_CONF,

                  "SQL query for DBD Authz or login"),

    AP_INIT_TAKE1("AuthzDBDRedirectQuery", authz_dbd_prepare,

                  (void*)APR_OFFSETOF(authz_dbd_cfg, redir_query), ACCESS_CONF,

                  "SQL query to get per-user redirect URL after login"),

    {NULL}

};

static int authz_dbd_login(request_rec *r, authz_dbd_cfg *cfg,

                           const char *action)

{

    int rv;

    const char *newuri = NULL;

    int nrows;

    const char *message;

    ap_dbd_t *dbd;

    apr_dbd_prepared_t *query;

    apr_dbd_results_t *res = NULL;

    apr_dbd_row_t *row = NULL;

    if (cfg->query == NULL) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01642)

                      "No query configured for %s!", action);

        return HTTP_INTERNAL_SERVER_ERROR;

    }

    dbd = dbd_handle(r);

    if (dbd == NULL) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02902)

                      "No db handle available for %s! "

                      "Check your database access",

                      action);

        return HTTP_INTERNAL_SERVER_ERROR;

    }

    query = apr_hash_get(dbd->prepared, cfg->query, APR_HASH_KEY_STRING);

    if (query == NULL) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01643)

                      "Error retrieving Query for %s!", action);

        return HTTP_INTERNAL_SERVER_ERROR;

    }

    rv = apr_dbd_pvquery(dbd->driver, r->pool, dbd->handle, &nrows,

                         query, r->user, NULL);

    if (rv == 0) {

        if (nrows != 1) {

            ap_log_rerror(APLOG_MARK, APLOG_WARNING, 0, r, APLOGNO(01644)

                          "authz_dbd: %s of user %s updated %d rows",

                          action, r->user, nrows);

        }

    }

    else {

        message = apr_dbd_error(dbd->driver, dbd->handle, rv);

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01645)

                      "authz_dbd: query for %s failed; user %s [%s]",

                      action, r->user, message?message:noerror);

        return HTTP_INTERNAL_SERVER_ERROR;

    }

    if (cfg->redirect == 1) {

        newuri = apr_table_get(r->headers_in, "Referer");

    }

    if (!newuri && cfg->redir_query) {

        query = apr_hash_get(dbd->prepared, cfg->redir_query,

                             APR_HASH_KEY_STRING);

        if (query == NULL) {

            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01646)

                          "authz_dbd: no redirect query!");

            /* OK, this is non-critical; we can just not-redirect */

        }

        else if ((rv = apr_dbd_pvselect(dbd->driver, r->pool, dbd->handle,

                                        &res, query, 0, r->user, NULL)) == 0) {

            for (rv = apr_dbd_get_row(dbd->driver, r->pool, res, &row, -1);

                 rv != -1;

                 rv = apr_dbd_get_row(dbd->driver, r->pool, res, &row, -1)) {

                if (rv != 0) {

                    message = apr_dbd_error(dbd->driver, dbd->handle, rv);

                    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01647)

                          "authz_dbd in get_row; action=%s user=%s [%s]",

                          action, r->user, message?message:noerror);

                }

                else if (newuri == NULL) {

                    newuri =

                        apr_pstrdup(r->pool,

                                    apr_dbd_get_entry(dbd->driver, row, 0));

                }

                /* we can't break out here or row won't get cleaned up */

            }

        }

        else {

            message = apr_dbd_error(dbd->driver, dbd->handle, rv);

            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01648)

                          "authz_dbd/redirect for %s of %s [%s]",

                          action, r->user, message?message:noerror);

        }

    }

    if (newuri != NULL) {

        r->status = HTTP_MOVED_TEMPORARILY;

        apr_table_set(r->err_headers_out, "Location", newuri);

    }

    authz_dbd_run_client_login(r, OK, action);

    return OK;

}

static int authz_dbd_group_query(request_rec *r, authz_dbd_cfg *cfg,

                                 apr_array_header_t *groups)

{

    /* SELECT group FROM authz WHERE user = %s */

    int rv;

    const char *message;

    ap_dbd_t *dbd;

    apr_dbd_prepared_t *query;

    apr_dbd_results_t *res = NULL;

    apr_dbd_row_t *row = NULL;

    if (cfg->query == NULL) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01649)

                      "No query configured for dbd-group!");

        return HTTP_INTERNAL_SERVER_ERROR;

    }

    dbd = dbd_handle(r);

    if (dbd == NULL) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02903)

                      "No db handle available for dbd-query! "

                      "Check your database access");

        return HTTP_INTERNAL_SERVER_ERROR;

    }

    query = apr_hash_get(dbd->prepared, cfg->query, APR_HASH_KEY_STRING);

    if (query == NULL) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01650)

                      "Error retrieving query for dbd-group!");

        return HTTP_INTERNAL_SERVER_ERROR;

    }

    rv = apr_dbd_pvselect(dbd->driver, r->pool, dbd->handle, &res,

                          query, 0, r->user, NULL);

    if (rv == 0) {

        for (rv = apr_dbd_get_row(dbd->driver, r->pool, res, &row, -1);

             rv != -1;

             rv = apr_dbd_get_row(dbd->driver, r->pool, res, &row, -1)) {

            if (rv == 0) {

                APR_ARRAY_PUSH(groups, const char *) =

                    apr_pstrdup(r->pool,

                                apr_dbd_get_entry(dbd->driver, row, 0));

            }

            else {

                message = apr_dbd_error(dbd->driver, dbd->handle, rv);

                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01651)

                        "authz_dbd in get_row; group query for user=%s [%s]",

                        r->user, message?message:noerror);

                return HTTP_INTERNAL_SERVER_ERROR;

            }

        }

    }

    else {

        message = apr_dbd_error(dbd->driver, dbd->handle, rv);

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01652)

                      "authz_dbd, in groups query for %s [%s]",

                      r->user, message?message:noerror);

        return HTTP_INTERNAL_SERVER_ERROR;

    }

    return OK;

}

static authz_status dbdgroup_check_authorization(request_rec *r,

                                                 const char *require_args,

                                                 const void *parsed_require_args)

{

    int rv;

    const char *w;

    apr_array_header_t *groups;

    const char *err = NULL;

    const ap_expr_info_t *expr = parsed_require_args;

    const char *require;

    const char *t;

    authz_dbd_cfg *cfg = ap_get_module_config(r->per_dir_config,

                                              &authz_dbd_module);

    if (!r->user) {

        return AUTHZ_DENIED_NO_USER;

    }

    groups = apr_array_make(r->pool, 4, sizeof(const char*));

    rv = authz_dbd_group_query(r, cfg, groups);

    if (rv != OK) {

        return AUTHZ_GENERAL_ERROR;

    }

    require = ap_expr_str_exec(r, expr, &err;;

    if (err) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02590)

                      "authz_dbd authorize: require dbd-group: Can't "

                      "evaluate require expression: %s", err);

        return AUTHZ_DENIED;

    }

    t = require;

    while (t[0]) {

        w = ap_getword_white(r->pool, &t);

        if (ap_array_str_contains(groups, w)) {

            return AUTHZ_GRANTED;

        }

    }

    return AUTHZ_DENIED;

}

static authz_status dbdlogin_check_authorization(request_rec *r,

                                                 const char *require_args,

                                                 const void *parsed_require_args)

{

    authz_dbd_cfg *cfg = ap_get_module_config(r->per_dir_config,

                                              &authz_dbd_module);

    if (!r->user) {

        return AUTHZ_DENIED_NO_USER;

    }

    return (authz_dbd_login(r, cfg, "login") == OK ? AUTHZ_GRANTED : AUTHZ_DENIED);

}

static authz_status dbdlogout_check_authorization(request_rec *r,

                                                  const char *require_args,

                                                  const void *parsed_require_args)

{

    authz_dbd_cfg *cfg = ap_get_module_config(r->per_dir_config,

                                              &authz_dbd_module);

    if (!r->user) {

        return AUTHZ_DENIED_NO_USER;

    }

    return (authz_dbd_login(r, cfg, "logout") == OK ? AUTHZ_GRANTED : AUTHZ_DENIED);

}

static const char *dbd_parse_config(cmd_parms *cmd, const char *require_line,

                                    const void **parsed_require_line)

{

    const char *expr_err = NULL;

    ap_expr_info_t *expr;

    expr = ap_expr_parse_cmd(cmd, require_line, AP_EXPR_FLAG_STRING_RESULT,

                             &expr_err, NULL);

    if (expr_err) {

        return apr_pstrcat(cmd->temp_pool,

                           "Cannot parse expression in require line: ",

                           expr_err, NULL);

    }

    *parsed_require_line = expr;

    return NULL;

}

static const authz_provider authz_dbdgroup_provider =

{

    &dbdgroup_check_authorization,

    &dbd_parse_config,

};

static const authz_provider authz_dbdlogin_provider =

{

    &dbdlogin_check_authorization,

    NULL,

};

static const authz_provider authz_dbdlogout_provider =

{

    &dbdlogout_check_authorization,

    NULL,

};

static void authz_dbd_hooks(apr_pool_t *p)

{

    ap_register_auth_provider(p, AUTHZ_PROVIDER_GROUP, "dbd-group",

                              AUTHZ_PROVIDER_VERSION,

                              &authz_dbdgroup_provider,

                              AP_AUTH_INTERNAL_PER_CONF);

    ap_register_auth_provider(p, AUTHZ_PROVIDER_GROUP, "dbd-login",

                              AUTHZ_PROVIDER_VERSION,

                              &authz_dbdlogin_provider,

                              AP_AUTH_INTERNAL_PER_CONF);

    ap_register_auth_provider(p, AUTHZ_PROVIDER_GROUP, "dbd-logout",

                              AUTHZ_PROVIDER_VERSION,

                              &authz_dbdlogout_provider,

                              AP_AUTH_INTERNAL_PER_CONF);

}

AP_DECLARE_MODULE(authz_dbd) =

{

    STANDARD20_MODULE_STUFF,

    authz_dbd_cr_cfg,

    authz_dbd_merge_cfg,

    NULL,

    NULL,

    authz_dbd_cmds,

    authz_dbd_hooks

};