/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <sys/cdefs.h>
/* Many bug fixes are from Jim Guyton <guyton@rand-unix> */

/*
 * TFTP User Program -- Protocol Machines
 */
#include <sys/socket.h>
#include <sys/stat.h>

#include <netinet/in.h>

#include <arpa/tftp.h>

#include <assert.h>
#include <err.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>

#include "tftp.h"
#include "tftp-file.h"
#include "tftp-utils.h"
#include "tftp-io.h"
#include "tftp-transfer.h"
#include "tftp-options.h"

/*
 * Send the requested file.
 */
int
xmitfile(int peer, char *port, int fd, char *name, char *mode)
{
        struct tftphdr *rp;
        int n, i, ret = 0;
        uint16_t block;
        struct sockaddr_storage serv;   /* valid server port number */
        char recvbuffer[MAXPKTSIZE];
        struct tftp_stats tftp_stats;

        stats_init(&tftp_stats);

        memset(&serv, 0, sizeof(serv));
        rp = (struct tftphdr *)recvbuffer;

        if (port == NULL) {
                struct servent *se;
                se = getservbyname("tftp", "udp");
                assert(se != NULL);
                ((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
        } else
                ((struct sockaddr_in *)&peer_sock)->sin_port =
                    htons(atoi(port));

        for (i = 0; i < 12; i++) {
                struct sockaddr_storage from;

                /* Tell the other side what we want to do */
                if (debug & DEBUG_SIMPLE)
                        printf("Sending %s\n", name);

                n = send_wrq(peer, name, mode);
                if (n > 0) {
                        printf("Cannot send WRQ packet\n");
                        return -1;
                }

                /*
                 * The first packet we receive has the new destination port
                 * we have to send the next packets to.
                 */
                n = receive_packet(peer, recvbuffer,
                    MAXPKTSIZE, &from, timeoutpacket);

                /* We got some data! */
                if (n >= 0) {
                        ((struct sockaddr_in *)&peer_sock)->sin_port =
                            ((struct sockaddr_in *)&from)->sin_port;
                        break;
                }

                /* This should be retried */
                if (n == RP_TIMEOUT) {
                        printf("Try %d, didn't receive answer from remote.\n",
                            i + 1);
                        continue;
                }

                /* Everything else is fatal */
                break;
        }
        if (i == 12) {
                printf("Transfer timed out.\n");
                return -1;
        }
        if (rp->th_opcode == ERROR) {
                printf("Got ERROR, aborted\n");
                return -1;
        }

        /*
         * If the first packet is an OACK instead of an ACK packet,
         * handle it different.
         */
        if (rp->th_opcode == OACK) {
                if (!options_rfc_enabled) {
                        printf("Got OACK while options are not enabled!\n");
                        send_error(peer, EBADOP);
                        return -1;
                }

                parse_options(peer, rp->th_stuff, n + 2);
        }

        if (read_init(fd, NULL, mode) < 0) {
                warn("read_init()");
                return -1;
        }

        block = 1;
        if (tftp_send(peer, &block, &tftp_stats) != 0)
                ret = -1;

        read_close();
        if (tftp_stats.amount > 0)
                printstats("Sent", verbose, &tftp_stats);
        return ret;
}

/*
 * Receive a file.
 */
int
recvfile(int peer, char *port, int fd, char *name, char *mode)
{
        struct tftphdr *rp;
        uint16_t block;
        char recvbuffer[MAXPKTSIZE];
        int n, i, ret = 0;
        struct tftp_stats tftp_stats;

        stats_init(&tftp_stats);

        rp = (struct tftphdr *)recvbuffer;

        if (port == NULL) {
                struct servent *se;
                se = getservbyname("tftp", "udp");
                assert(se != NULL);
                ((struct sockaddr_in *)&peer_sock)->sin_port = se->s_port;
        } else
                ((struct sockaddr_in *)&peer_sock)->sin_port =
                    htons(atoi(port));

        for (i = 0; i < 12; i++) {
                struct sockaddr_storage from;

                /* Tell the other side what we want to do */
                if (debug & DEBUG_SIMPLE)
                        printf("Requesting %s\n", name);

                n = send_rrq(peer, name, mode);
                if (n > 0) {
                        printf("Cannot send RRQ packet\n");
                        return -1;
                }

                /*
                 * The first packet we receive has the new destination port
                 * we have to send the next packets to.
                 */
                n = receive_packet(peer, recvbuffer,
                    MAXPKTSIZE, &from, timeoutpacket);

                /* We got something useful! */
                if (n >= 0) {
                        ((struct sockaddr_in *)&peer_sock)->sin_port =
                            ((struct sockaddr_in *)&from)->sin_port;
                        break;
                }

                /* We should retry if this happens */
                if (n == RP_TIMEOUT) {
                        printf("Try %d, didn't receive answer from remote.\n",
                            i + 1);
                        continue;
                }

                /* Otherwise it is a fatal error */
                break;
        }
        if (i == 12) {
                printf("Transfer timed out.\n");
                return -1;
        }
        if (rp->th_opcode == ERROR) {
                tftp_log(LOG_ERR, "Error code %d: %s", rp->th_code, rp->th_msg);
                return -1;
        }

        if (write_init(fd, NULL, mode) < 0) {
                warn("write_init");
                return -1;
        }

        /*
         * If the first packet is an OACK packet instead of an DATA packet,
         * handle it different.
         */
        if (rp->th_opcode == OACK) {
                if (!options_rfc_enabled) {
                        printf("Got OACK while options are not enabled!\n");
                        send_error(peer, EBADOP);
                        return -1;
                }

                parse_options(peer, rp->th_stuff, n + 2);

                n = send_ack(peer, 0);
                if (n > 0) {
                        printf("Cannot send ACK on OACK.\n");
                        return -1;
                }
                block = 0;
                if (tftp_receive(peer, &block, &tftp_stats, NULL, 0) != 0)
                        ret = -1;
        } else {
                block = 1;
                if (tftp_receive(peer, &block, &tftp_stats, rp, n) != 0)
                        ret = -1;
        }

        if (tftp_stats.amount > 0)
                printstats("Received", verbose, &tftp_stats);
        return ret;
}