/*-
 * 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.
 *
 * $FreeBSD: src/usr.sbin/nscd/nscdcli.c,v 1.5 2008/10/23 00:28:21 delphij Exp $
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/event.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "debug.h"
#include "nscdcli.h"
#include "protocol.h"

#define DEFAULT_NSCD_IO_TIMEOUT 4

static int safe_write(struct nscd_connection_ *, const void *, size_t);
static int safe_read(struct nscd_connection_ *, void *, size_t);
static int send_credentials(struct nscd_connection_ *, int);

static int
safe_write(struct nscd_connection_ *connection, const void *data,
        size_t data_size)
{
        struct kevent eventlist;
        int     nevents;
        size_t result;
        ssize_t s_result;
        struct timespec timeout;

        if (data_size == 0)
                return (0);

        timeout.tv_sec = DEFAULT_NSCD_IO_TIMEOUT;
        timeout.tv_nsec = 0;
        result = 0;
        do {
                nevents = kevent(connection->write_queue, NULL, 0, &eventlist,
                        1, &timeout);
                if ((nevents == 1) && (eventlist.filter == EVFILT_WRITE)) {
                        s_result = write(connection->sockfd, data + result,
                                eventlist.data < data_size - result ?
                                eventlist.data : data_size - result);
                        if (s_result == -1)
                                return (-1);
                        else
                                result += s_result;

                        if (eventlist.flags & EV_EOF)
                                return (result < data_size ? -1 : 0);
                } else
                        return (-1);
        } while (result < data_size);

        return (0);
}

static int
safe_read(struct nscd_connection_ *connection, void *data, size_t data_size)
{
        struct kevent eventlist;
        size_t result;
        ssize_t s_result;
        struct timespec timeout;
        int nevents;

        if (data_size == 0)
                return (0);

        timeout.tv_sec = DEFAULT_NSCD_IO_TIMEOUT;
        timeout.tv_nsec = 0;
        result = 0;
        do {
                nevents = kevent(connection->read_queue, NULL, 0, &eventlist, 1,
                        &timeout);
                if ((nevents == 1) && (eventlist.filter == EVFILT_READ)) {
                        s_result = read(connection->sockfd, data + result,
                        eventlist.data <= data_size - result ? eventlist.data :
                                data_size - result);
                        if (s_result == -1)
                                return (-1);
                        else
                                result += s_result;

                        if (eventlist.flags & EV_EOF)
                                return (result < data_size ? -1 : 0);
                } else
                        return (-1);
        } while (result < data_size);

        return (0);
}

static int
send_credentials(struct nscd_connection_ *connection, int type)
{
        struct kevent eventlist;
        int nevents;
        ssize_t result;
        int res;

        struct msghdr   cred_hdr;
        struct iovec    iov;

        struct {
                struct cmsghdr  hdr;
                struct cmsgcred creds;
        } cmsg;

        TRACE_IN(send_credentials);
        memset(&cmsg, 0, sizeof(cmsg));
        cmsg.hdr.cmsg_len = sizeof(cmsg);
        cmsg.hdr.cmsg_level = SOL_SOCKET;
        cmsg.hdr.cmsg_type = SCM_CREDS;

        memset(&cred_hdr, 0, sizeof(struct msghdr));
        cred_hdr.msg_iov = &iov;
        cred_hdr.msg_iovlen = 1;
        cred_hdr.msg_control = &cmsg;
        cred_hdr.msg_controllen = sizeof(cmsg);

        iov.iov_base = &type;
        iov.iov_len = sizeof(int);

        EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
                NOTE_LOWAT, sizeof(int), NULL);
        res = kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);

        nevents = kevent(connection->write_queue, NULL, 0, &eventlist, 1, NULL);
        if ((nevents == 1) && (eventlist.filter == EVFILT_WRITE)) {
                result = (sendmsg(connection->sockfd, &cred_hdr, 0) == -1) ? -1
                        : 0;
                EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD,
                        0, 0, NULL);
                kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL);
                TRACE_OUT(send_credentials);
                return (result);
        } else {
                TRACE_OUT(send_credentials);
                return (-1);
        }
}

struct nscd_connection_ *
open_nscd_connection__(struct nscd_connection_params const *params)
{
        struct nscd_connection_ *retval;
        struct kevent eventlist;
        struct sockaddr_un      client_address;
        int client_address_len, client_socket;
        int res;

        TRACE_IN(open_nscd_connection);
        assert(params != NULL);

        client_socket = socket(PF_LOCAL, SOCK_STREAM, 0);
        client_address.sun_family = PF_LOCAL;
        strlcpy(client_address.sun_path, params->socket_path,
                sizeof(client_address.sun_path));
        client_address_len = sizeof(client_address.sun_family) +
                strlen(client_address.sun_path) + 1;

        res = connect(client_socket, (struct sockaddr *)&client_address,
                client_address_len);
        if (res == -1) {
                close(client_socket);
                TRACE_OUT(open_nscd_connection);
                return (NULL);
        }
        fcntl(client_socket, F_SETFL, O_NONBLOCK);

        retval = calloc(1, sizeof(struct nscd_connection_));
        assert(retval != NULL);

        retval->sockfd = client_socket;

        retval->write_queue = kqueue();
        assert(retval->write_queue != -1);

        EV_SET(&eventlist, retval->sockfd, EVFILT_WRITE, EV_ADD,
                0, 0, NULL);
        res = kevent(retval->write_queue, &eventlist, 1, NULL, 0, NULL);

        retval->read_queue = kqueue();
        assert(retval->read_queue != -1);

        EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD,
                0, 0, NULL);
        res = kevent(retval->read_queue, &eventlist, 1, NULL, 0, NULL);

        TRACE_OUT(open_nscd_connection);
        return (retval);
}

void
close_nscd_connection__(struct nscd_connection_ *connection)
{

        TRACE_IN(close_nscd_connection);
        assert(connection != NULL);

        close(connection->sockfd);
        close(connection->read_queue);
        close(connection->write_queue);
        free(connection);
        TRACE_OUT(close_nscd_connection);
}

int
nscd_transform__(struct nscd_connection_ *connection,
        const char *entry_name, int transformation_type)
{
        size_t name_size;
        int error_code;
        int result;

        TRACE_IN(nscd_transform);

        error_code = -1;
        result = 0;
        result = send_credentials(connection, CET_TRANSFORM_REQUEST);
        if (result != 0)
                goto fin;

        if (entry_name != NULL)
                name_size = strlen(entry_name);
        else
                name_size = 0;

        result = safe_write(connection, &name_size, sizeof(size_t));
        if (result != 0)
                goto fin;

        result = safe_write(connection, &transformation_type, sizeof(int));
        if (result != 0)
                goto fin;

        if (entry_name != NULL) {
                result = safe_write(connection, entry_name, name_size);
                if (result != 0)
                        goto fin;
        }

        result = safe_read(connection, &error_code, sizeof(int));
        if (result != 0)
                error_code = -1;

fin:
        TRACE_OUT(nscd_transform);
        return (error_code);
}