/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (C) 2008 Edwin Groothuis. 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 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 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 <sys/cdefs.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/tftp.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include "tftp-file.h"
#include "tftp-io.h"
#include "tftp-utils.h"
#include "tftp-options.h"
#include "tftp-transfer.h"
struct block_data {
off_t offset;
uint16_t block;
int size;
};
/*
* Send a file via the TFTP data session.
*/
int
tftp_send(int peer, uint16_t *block, struct tftp_stats *ts)
{
struct tftphdr *rp;
int size, n_data, n_ack, sendtry, acktry;
u_int i, j;
uint16_t oldblock, windowblock;
char sendbuffer[MAXPKTSIZE];
char recvbuffer[MAXPKTSIZE];
struct block_data window[WINDOWSIZE_MAX];
rp = (struct tftphdr *)recvbuffer;
*block = 1;
ts->amount = 0;
windowblock = 0;
acktry = 0;
do {
read_block:
if (debug & DEBUG_SIMPLE)
tftp_log(LOG_DEBUG, "Sending block %d (window block %d)",
*block, windowblock);
window[windowblock].offset = tell_file();
window[windowblock].block = *block;
size = read_file(sendbuffer, segsize);
if (size < 0) {
tftp_log(LOG_ERR, "read_file returned %d", size);
send_error(peer, errno + 100);
return -1;
}
window[windowblock].size = size;
windowblock++;
for (sendtry = 0; ; sendtry++) {
n_data = send_data(peer, *block, sendbuffer, size);
if (n_data == 0)
break;
if (sendtry == maxtimeouts) {
tftp_log(LOG_ERR,
"Cannot send DATA packet #%d, "
"giving up", *block);
return -1;
}
tftp_log(LOG_ERR,
"Cannot send DATA packet #%d, trying again",
*block);
}
/* Only check for ACK for last block in window. */
if (windowblock == windowsize || size != segsize) {
n_ack = receive_packet(peer, recvbuffer,
MAXPKTSIZE, NULL, timeoutpacket);
if (n_ack < 0) {
if (n_ack == RP_TIMEOUT) {
if (acktry == maxtimeouts) {
tftp_log(LOG_ERR,
"Timeout #%d send ACK %d "
"giving up", acktry, *block);
return -1;
}
tftp_log(LOG_WARNING,
"Timeout #%d on ACK %d",
acktry, *block);
acktry++;
ts->retries++;
if (seek_file(window[0].offset) != 0) {
tftp_log(LOG_ERR,
"seek_file failed: %s",
strerror(errno));
send_error(peer, errno + 100);
return -1;
}
*block = window[0].block;
windowblock = 0;
goto read_block;
}
/* Either read failure or ERROR packet */
if (debug & DEBUG_SIMPLE)
tftp_log(LOG_ERR, "Aborting: %s",
rp_strerror(n_ack));
return -1;
}
if (rp->th_opcode == ACK) {
/*
* Look for the ACKed block in our open
* window.
*/
for (i = 0; i < windowblock; i++) {
if (rp->th_block == window[i].block)
break;
}
if (i == windowblock) {
/* Did not recognize ACK. */
if (debug & DEBUG_SIMPLE)
tftp_log(LOG_DEBUG,
"ACK %d out of window",
rp->th_block);
/* Re-synchronize with the other side */
(void) synchnet(peer);
/* Resend the current window. */
ts->retries++;
if (seek_file(window[0].offset) != 0) {
tftp_log(LOG_ERR,
"seek_file failed: %s",
strerror(errno));
send_error(peer, errno + 100);
return -1;
}
*block = window[0].block;
windowblock = 0;
goto read_block;
}
/* ACKed at least some data. */
acktry = 0;
for (j = 0; j <= i; j++) {
if (debug & DEBUG_SIMPLE)
tftp_log(LOG_DEBUG,
"ACKed block %d",
window[j].block);
ts->blocks++;
ts->amount += window[j].size;
}
/*
* Partial ACK. Rewind state to first
* un-ACKed block.
*/
if (i + 1 != windowblock) {
if (debug & DEBUG_SIMPLE)
tftp_log(LOG_DEBUG,
"Partial ACK");
if (seek_file(window[i + 1].offset) !=
0) {
tftp_log(LOG_ERR,
"seek_file failed: %s",
strerror(errno));
send_error(peer, errno + 100);
return -1;
}
*block = window[i + 1].block;
windowblock = 0;
ts->retries++;
goto read_block;
}
windowblock = 0;
}
}
oldblock = *block;
(*block)++;
if (oldblock > *block) {
if (options[OPT_ROLLOVER].o_request == NULL) {
/*
* "rollover" option not specified in
* tftp client. Default to rolling block
* counter to 0.
*/
*block = 0;
} else {
*block = atoi(options[OPT_ROLLOVER].o_request);
}
ts->rollovers++;
}
gettimeofday(&(ts->tstop), NULL);
} while (size == segsize);
return 0;
}
/*
* Receive a file via the TFTP data session.
*
* - It could be that the first block has already arrived while
* trying to figure out if we were receiving options or not. In
* that case it is passed to this function.
*/
int
tftp_receive(int peer, uint16_t *block, struct tftp_stats *ts,
struct tftphdr *firstblock, size_t fb_size)
{
struct tftphdr *rp;
uint16_t oldblock, windowstart;
int n_data, n_ack, writesize, i, retry, windowblock;
char recvbuffer[MAXPKTSIZE];
ts->amount = 0;
windowblock = 0;
if (firstblock != NULL) {
writesize = write_file(firstblock->th_data, fb_size);
ts->amount += writesize;
ts->blocks++;
windowblock++;
if (windowsize == 1 || fb_size != segsize) {
for (i = 0; ; i++) {
n_ack = send_ack(peer, *block);
if (n_ack > 0) {
if (i == maxtimeouts) {
tftp_log(LOG_ERR,
"Cannot send ACK packet #%d, "
"giving up", *block);
return -1;
}
tftp_log(LOG_ERR,
"Cannot send ACK packet #%d, trying again",
*block);
continue;
}
break;
}
}
if (fb_size != segsize) {
write_close();
gettimeofday(&(ts->tstop), NULL);
return 0;
}
}
rp = (struct tftphdr *)recvbuffer;
do {
oldblock = *block;
(*block)++;
if (oldblock > *block) {
if (options[OPT_ROLLOVER].o_request == NULL) {
/*
* "rollover" option not specified in
* tftp client. Default to rolling block
* counter to 0.
*/
*block = 0;
} else {
*block = atoi(options[OPT_ROLLOVER].o_request);
}
ts->rollovers++;
}
for (retry = 0; ; retry++) {
if (debug & DEBUG_SIMPLE)
tftp_log(LOG_DEBUG,
"Receiving DATA block %d (window block %d)",
*block, windowblock);
n_data = receive_packet(peer, recvbuffer,
MAXPKTSIZE, NULL, timeoutpacket);
if (n_data < 0) {
if (retry == maxtimeouts) {
tftp_log(LOG_ERR,
"Timeout #%d on DATA block %d, "
"giving up", retry, *block);
return -1;
}
if (n_data == RP_TIMEOUT) {
tftp_log(LOG_WARNING,
"Timeout #%d on DATA block %d",
retry, *block);
send_ack(peer, oldblock);
windowblock = 0;
continue;
}
/* Either read failure or ERROR packet */
if (debug & DEBUG_SIMPLE)
tftp_log(LOG_DEBUG, "Aborting: %s",
rp_strerror(n_data));
return -1;
}
if (rp->th_opcode == DATA) {
ts->blocks++;
if (rp->th_block == *block)
break;
/*
* Ignore duplicate blocks within the
* window.
*
* This does not handle duplicate
* blocks during a rollover as
* gracefully, but that should still
* recover eventually.
*/
if (*block > windowsize)
windowstart = *block - windowsize;
else
windowstart = 0;
if (rp->th_block > windowstart &&
rp->th_block < *block) {
if (debug & DEBUG_SIMPLE)
tftp_log(LOG_DEBUG,
"Ignoring duplicate DATA block %d",
rp->th_block);
windowblock++;
retry = 0;
continue;
}
tftp_log(LOG_WARNING,
"Expected DATA block %d, got block %d",
*block, rp->th_block);
/* Re-synchronize with the other side */
(void) synchnet(peer);
tftp_log(LOG_INFO, "Trying to sync");
*block = oldblock;
ts->retries++;
goto send_ack; /* rexmit */
} else {
tftp_log(LOG_WARNING,
"Expected DATA block, got %s block",
packettype(rp->th_opcode));
}
}
if (n_data > 0) {
writesize = write_file(rp->th_data, n_data);
ts->amount += writesize;
if (writesize <= 0) {
tftp_log(LOG_ERR,
"write_file returned %d", writesize);
if (writesize < 0)
send_error(peer, errno + 100);
else
send_error(peer, ENOSPACE);
return -1;
}
}
if (n_data != segsize)
write_close();
windowblock++;
/* Only send ACKs for the last block in the window. */
if (windowblock < windowsize && n_data == segsize)
continue;
send_ack:
for (i = 0; ; i++) {
n_ack = send_ack(peer, *block);
if (n_ack > 0) {
if (i == maxtimeouts) {
tftp_log(LOG_ERR,
"Cannot send ACK packet #%d, "
"giving up", *block);
return -1;
}
tftp_log(LOG_ERR,
"Cannot send ACK packet #%d, trying again",
*block);
continue;
}
if (debug & DEBUG_SIMPLE)
tftp_log(LOG_DEBUG, "Sent ACK for %d", *block);
windowblock = 0;
break;
}
gettimeofday(&(ts->tstop), NULL);
} while (n_data == segsize);
/* Don't do late packet management for the client implementation */
if (acting_as_client)
return 0;
for (i = 0; ; i++) {
n_data = receive_packet(peer, (char *)rp, pktsize,
NULL, -timeoutpacket);
if (n_data <= 0)
break;
if (n_data > 0 &&
rp->th_opcode == DATA && /* and got a data block */
*block == rp->th_block) /* then my last ack was lost */
send_ack(peer, *block); /* resend final ack */
}
return 0;
}
