/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include "namespace.h"
#define _NS_PRIVATE
#include <nsswitch.h>
#include <stdlib.h>
#include <string.h>
#include "un-namespace.h"
#include "nscachedcli.h"
#include "nscache.h"

#define NSS_CACHE_KEY_INITIAL_SIZE      (256)
#define NSS_CACHE_KEY_SIZE_LIMIT        (NSS_CACHE_KEY_INITIAL_SIZE << 4)

#define NSS_CACHE_BUFFER_INITIAL_SIZE   (1024)
#define NSS_CACHE_BUFFER_SIZE_LIMIT     (NSS_CACHE_BUFFER_INITIAL_SIZE << 8)

#define CACHED_SOCKET_PATH              "/var/run/nscd"

int
__nss_cache_handler(void *retval, void *mdata, va_list ap)
{
        return (NS_UNAVAIL);
}

int
__nss_common_cache_read(void *retval, void *mdata, va_list ap)
{
        struct cached_connection_params params;
        cached_connection connection;

        char *buffer;
        size_t buffer_size, size;

        nss_cache_info const *cache_info;
        nss_cache_data *cache_data;
        va_list ap_new;
        int res;

        cache_data = (nss_cache_data *)mdata;
        cache_info = cache_data->info;

        memset(&params, 0, sizeof(struct cached_connection_params));
        params.socket_path = CACHED_SOCKET_PATH;

        cache_data->key = (char *)malloc(NSS_CACHE_KEY_INITIAL_SIZE);
        memset(cache_data->key, 0, NSS_CACHE_KEY_INITIAL_SIZE);
        cache_data->key_size = NSS_CACHE_KEY_INITIAL_SIZE;
        va_copy(ap_new, ap);

        do {
                size = cache_data->key_size;
                res = cache_info->id_func(cache_data->key, &size, ap_new,
                    cache_info->mdata);
                va_end(ap_new);
                if (res == NS_RETURN) {
                        if (cache_data->key_size > NSS_CACHE_KEY_SIZE_LIMIT)
                                break;

                        cache_data->key_size <<= 1;
                        cache_data->key = realloc(cache_data->key,
                            cache_data->key_size);
                        memset(cache_data->key, 0, cache_data->key_size);
                        va_copy(ap_new, ap);
                }
        } while (res == NS_RETURN);

        if (res != NS_SUCCESS) {
                free(cache_data->key);
                cache_data->key = NULL;
                cache_data->key_size = 0;
                return (res);
        } else
                cache_data->key_size = size;

        buffer_size = NSS_CACHE_BUFFER_INITIAL_SIZE;
        buffer = (char *)malloc(NSS_CACHE_BUFFER_INITIAL_SIZE);
        memset(buffer, 0, NSS_CACHE_BUFFER_INITIAL_SIZE);

        do {
                connection = __open_cached_connection(&params);
                if (connection == NULL) {
                        res = -1;
                        break;
                }
                res = __cached_read(connection, cache_info->entry_name,
                    cache_data->key, cache_data->key_size, buffer,
                    &buffer_size);
                __close_cached_connection(connection);
                if (res == -2 && buffer_size < NSS_CACHE_BUFFER_SIZE_LIMIT) {
                        buffer = (char *)realloc(buffer, buffer_size);
                        memset(buffer, 0, buffer_size);
                }
        } while (res == -2);

        if (res == 0) {
                if (buffer_size == 0) {
                        free(buffer);
                        free(cache_data->key);
                        cache_data->key = NULL;
                        cache_data->key_size = 0;
                        return (NS_RETURN);
                }

                va_copy(ap_new, ap);
                res = cache_info->unmarshal_func(buffer, buffer_size, retval,
                    ap_new, cache_info->mdata);
                va_end(ap_new);

                if (res != NS_SUCCESS) {
                        free(buffer);
                        free(cache_data->key);
                        cache_data->key = NULL;
                        cache_data->key_size = 0;
                        return (res);
                } else
                        res = 0;
        }

        if (res == 0) {
                free(cache_data->key);
                cache_data->key = NULL;
                cache_data->key_size = 0;
        }

        free(buffer);
        return (res == 0 ? NS_SUCCESS : NS_NOTFOUND);
}

int
__nss_common_cache_write(void *retval, void *mdata, va_list ap)
{
        struct cached_connection_params params;
        cached_connection connection;

        char *buffer;
        size_t buffer_size;

        nss_cache_info const *cache_info;
        nss_cache_data *cache_data;
        va_list ap_new;
        int res;

        cache_data = (nss_cache_data *)mdata;
        cache_info = cache_data->info;

        if (cache_data->key == NULL)
                return (NS_UNAVAIL);

        memset(&params, 0, sizeof(struct cached_connection_params));
        params.socket_path = CACHED_SOCKET_PATH;

        connection = __open_cached_connection(&params);
        if (connection == NULL) {
                free(cache_data->key);
                return (NS_UNAVAIL);
        }

        buffer_size = NSS_CACHE_BUFFER_INITIAL_SIZE;
        buffer = (char *)malloc(NSS_CACHE_BUFFER_INITIAL_SIZE);
        memset(buffer, 0, NSS_CACHE_BUFFER_INITIAL_SIZE);

        do {
                size_t size;

                size = buffer_size;
                va_copy(ap_new, ap);
                res = cache_info->marshal_func(buffer, &size, retval, ap_new,
                    cache_info->mdata);
                va_end(ap_new);

                if (res == NS_RETURN) {
                        if (buffer_size > NSS_CACHE_BUFFER_SIZE_LIMIT)
                                break;

                        buffer_size <<= 1;
                        buffer = (char *)realloc(buffer, buffer_size);
                        memset(buffer, 0, buffer_size);
                }
        } while (res == NS_RETURN);

        if (res != NS_SUCCESS) {
                __close_cached_connection(connection);
                free(cache_data->key);
                free(buffer);
                return (res);
        }

        res = __cached_write(connection, cache_info->entry_name,
            cache_data->key, cache_data->key_size, buffer, buffer_size);
        __close_cached_connection(connection);

        free(cache_data->key);
        free(buffer);

        return (res == 0 ? NS_SUCCESS : NS_UNAVAIL);
}

int
__nss_common_cache_write_negative(void *mdata)
{
        struct cached_connection_params params;
        cached_connection connection;
        int res;

        nss_cache_info const *cache_info;
        nss_cache_data *cache_data;

        cache_data = (nss_cache_data *)mdata;
        cache_info = cache_data->info;

        if (cache_data->key == NULL)
                return (NS_UNAVAIL);

        memset(&params, 0, sizeof(struct cached_connection_params));
        params.socket_path = CACHED_SOCKET_PATH;

        connection = __open_cached_connection(&params);
        if (connection == NULL) {
                free(cache_data->key);
                return (NS_UNAVAIL);
        }

        res = __cached_write(connection, cache_info->entry_name,
            cache_data->key, cache_data->key_size, NULL, 0);
        __close_cached_connection(connection);

        free(cache_data->key);
        return (res == 0 ? NS_SUCCESS : NS_UNAVAIL);
}

int
__nss_mp_cache_read(void *retval, void *mdata, va_list ap)
{
        struct cached_connection_params params;
        cached_mp_read_session rs;

        char *buffer;
        size_t buffer_size;

        nss_cache_info const *cache_info;
        nss_cache_data *cache_data;
        va_list ap_new;
        int res;

        cache_data = (nss_cache_data *)mdata;
        cache_info = cache_data->info;

        if (cache_info->get_mp_ws_func() != INVALID_CACHED_MP_WRITE_SESSION)
                return (NS_UNAVAIL);

        rs = cache_info->get_mp_rs_func();
        if (rs == INVALID_CACHED_MP_READ_SESSION) {
                memset(&params, 0, sizeof(struct cached_connection_params));
                params.socket_path = CACHED_SOCKET_PATH;

                rs = __open_cached_mp_read_session(&params,
                    cache_info->entry_name);
                if (rs == INVALID_CACHED_MP_READ_SESSION)
                        return (NS_UNAVAIL);

                cache_info->set_mp_rs_func(rs);
        }

        buffer_size = NSS_CACHE_BUFFER_INITIAL_SIZE;
        buffer = (char *)malloc(NSS_CACHE_BUFFER_INITIAL_SIZE);
        memset(buffer, 0, NSS_CACHE_BUFFER_INITIAL_SIZE);

        do {
                res = __cached_mp_read(rs, buffer, &buffer_size);
                if (res == -2 && buffer_size < NSS_CACHE_BUFFER_SIZE_LIMIT) {
                        buffer = (char *)realloc(buffer, buffer_size);
                        memset(buffer, 0, buffer_size);
                }
        } while (res == -2);

        if (res == 0) {
                va_copy(ap_new, ap);
                res = cache_info->unmarshal_func(buffer, buffer_size, retval,
                    ap_new, cache_info->mdata);
                va_end(ap_new);

                if (res != NS_SUCCESS) {
                        free(buffer);
                        return (res);
                } else
                        res = 0;
        } else {
                free(buffer);
                __close_cached_mp_read_session(rs);
                rs = INVALID_CACHED_MP_READ_SESSION;
                cache_info->set_mp_rs_func(rs);
                return (res == -1 ? NS_RETURN : NS_UNAVAIL);
        }

        free(buffer);
        return (res == 0 ? NS_SUCCESS : NS_NOTFOUND);
}

int
__nss_mp_cache_write(void *retval, void *mdata, va_list ap)
{
        struct cached_connection_params params;
        cached_mp_write_session ws;

        char *buffer;
        size_t buffer_size;

        nss_cache_info const *cache_info;
        nss_cache_data *cache_data;
        va_list ap_new;
        int res;

        cache_data = (nss_cache_data *)mdata;
        cache_info = cache_data->info;

        ws = cache_info->get_mp_ws_func();
        if (ws == INVALID_CACHED_MP_WRITE_SESSION) {
                memset(&params, 0, sizeof(struct cached_connection_params));
                params.socket_path = CACHED_SOCKET_PATH;

                ws = __open_cached_mp_write_session(&params,
                    cache_info->entry_name);
                if (ws == INVALID_CACHED_MP_WRITE_SESSION)
                        return (NS_UNAVAIL);

                cache_info->set_mp_ws_func(ws);
        }

        buffer_size = NSS_CACHE_BUFFER_INITIAL_SIZE;
        buffer = (char *)malloc(NSS_CACHE_BUFFER_INITIAL_SIZE);
        memset(buffer, 0, NSS_CACHE_BUFFER_INITIAL_SIZE);

        do {
                size_t size;

                size = buffer_size;
                va_copy(ap_new, ap);
                res = cache_info->marshal_func(buffer, &size, retval, ap_new,
                    cache_info->mdata);
                va_end(ap_new);

                if (res == NS_RETURN) {
                        if (buffer_size > NSS_CACHE_BUFFER_SIZE_LIMIT)
                                break;

                        buffer_size <<= 1;
                        buffer = (char *)realloc(buffer, buffer_size);
                        memset(buffer, 0, buffer_size);
                }
        } while (res == NS_RETURN);

        if (res != NS_SUCCESS) {
                free(buffer);
                return (res);
        }

        res = __cached_mp_write(ws, buffer, buffer_size);

        free(buffer);
        return (res == 0 ? NS_SUCCESS : NS_UNAVAIL);
}

int
__nss_mp_cache_write_submit(void *retval, void *mdata, va_list ap)
{
        cached_mp_write_session ws;

        nss_cache_info const *cache_info;
        nss_cache_data *cache_data;

        cache_data = (nss_cache_data *)mdata;
        cache_info = cache_data->info;

        ws = cache_info->get_mp_ws_func();
        if (ws != INVALID_CACHED_MP_WRITE_SESSION) {
                __close_cached_mp_write_session(ws);
                ws = INVALID_CACHED_MP_WRITE_SESSION;
                cache_info->set_mp_ws_func(ws);
        }
        return (NS_UNAVAIL);
}

int
__nss_mp_cache_end(void *retval, void *mdata, va_list ap)
{
        cached_mp_write_session ws;
        cached_mp_read_session rs;

        nss_cache_info const *cache_info;
        nss_cache_data *cache_data;

        cache_data = (nss_cache_data *)mdata;
        cache_info = cache_data->info;

        ws = cache_info->get_mp_ws_func();
        if (ws != INVALID_CACHED_MP_WRITE_SESSION) {
                __abandon_cached_mp_write_session(ws);
                ws = INVALID_CACHED_MP_WRITE_SESSION;
                cache_info->set_mp_ws_func(ws);
        }

        rs = cache_info->get_mp_rs_func();
        if (rs != INVALID_CACHED_MP_READ_SESSION) {
                __close_cached_mp_read_session(rs);
                rs = INVALID_CACHED_MP_READ_SESSION;
                cache_info->set_mp_rs_func(rs);
        }

        return (NS_UNAVAIL);
}