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/* $OpenBSD: getline.c,v 1.15 2003/06/28 01:04:57 deraadt Exp $ */
/*
* Copyright (c) 1985, 1988 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.
*
* @(#)ftpcmd.y 5.24 (Berkeley) 2/25/91
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/telnet.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sysexits.h>
#include <syslog.h>
#include <unistd.h>
#include "util.h"
int refill_buffer(struct csiob *iobp);
/*
* Refill the io buffer if we KNOW that data is available
*
* Returns 1 if any new data was obtained, 0 otherwise.
*/
int
refill_buffer(struct csiob *iobp)
{
int rqlen, rlen;
if (!(iobp->data_available))
return(0);
if (iobp->got_eof)
return(0);
/*
* The buffer has been entirely consumed if next_byte == io_buffer_len.
* Otherwise, there is some still-to-be-used data in io_buffer.
* Shuffle it to the start of the buffer.
* Note that next_byte will never exceed io_buffer_len.
* Also, note that we MUST use bcopy because the two regions could
* overlap (memcpy isn't defined to work properly with overlapping
* regions).
*/
if (iobp->next_byte < iobp->io_buffer_len) {
int dst_ix = 0;
int src_ix = iobp->next_byte;
int amount = iobp->io_buffer_len - iobp->next_byte;
bcopy(&iobp->io_buffer[src_ix], &iobp->io_buffer[dst_ix],
amount);
iobp->io_buffer_len = amount;
} else if (iobp->next_byte == iobp->io_buffer_len)
iobp->io_buffer_len = 0;
else {
syslog(LOG_ERR, "next_byte(%d) > io_buffer_len(%d)",
iobp->next_byte, iobp->io_buffer_len);
exit(EX_OSERR);
}
iobp->next_byte = 0;
/* don't do tiny reads, grow first if we need to */
rqlen = iobp->io_buffer_size - iobp->io_buffer_len;
if (rqlen <= 128) {
char *tmp;
iobp->io_buffer_size += 128;
tmp = realloc(iobp->io_buffer, iobp->io_buffer_size);
if (tmp == NULL) {
syslog(LOG_INFO, "Insufficient memory");
exit(EX_UNAVAILABLE);
}
iobp->io_buffer = tmp;
rqlen = iobp->io_buffer_size - iobp->io_buffer_len;
}
/*
* Always leave an unused byte at the end of the buffer
* because the debug output uses that byte from time to time
* to ensure that something that is being printed is \0 terminated.
*/
rqlen -= 1;
doread:
rlen = read(iobp->fd, &iobp->io_buffer[iobp->io_buffer_len], rqlen);
iobp->data_available = 0;
switch (rlen) {
case -1:
if (errno == EAGAIN || errno == EINTR)
goto doread;
if (errno != ECONNRESET) {
syslog(LOG_INFO, "read() failed on socket from %s (%m)",
iobp->who);
exit(EX_DATAERR);
}
/* fall through to EOF case */
case 0:
iobp->got_eof = 1;
return(0);
break;
default:
iobp->io_buffer_len += rlen;
break;
}
return(1);
}
/*
* telnet_getline - a hacked up version of fgets to ignore TELNET escape codes.
*
* This code is derived from the getline routine found in the UC Berkeley
* ftpd code.
*
*/
int
telnet_getline(struct csiob *iobp, struct csiob *telnet_passthrough)
{
unsigned char ch;
int ix;
char tbuf[100];
iobp->line_buffer[0] = '\0';
/*
* If the buffer is empty then refill it right away.
*/
if (iobp->next_byte == iobp->io_buffer_len)
if (!refill_buffer(iobp))
return(0);
/*
* Is there a telnet command in the buffer?
*/
ch = iobp->io_buffer[iobp->next_byte];
if (ch == IAC) {
/*
* Yes - buffer must have at least three bytes in it
*/
if (iobp->io_buffer_len - iobp->next_byte < 3) {
if (!refill_buffer(iobp))
return(0);
if (iobp->io_buffer_len - iobp->next_byte < 3)
return(0);
}
iobp->next_byte++;
ch = iobp->io_buffer[iobp->next_byte++];
switch (ch) {
case WILL:
case WONT:
case DO:
case DONT:
tbuf[0] = IAC;
tbuf[1] = ch;
tbuf[2] = iobp->io_buffer[iobp->next_byte++];
(void)send(telnet_passthrough->fd, tbuf, 3,
telnet_passthrough->send_oob_flags);
break;
case IAC:
break;
default:
break;
}
return(1);
} else {
int clen;
/*
* Is there a newline in the buffer?
*/
for (ix = iobp->next_byte; ix < iobp->io_buffer_len;
ix += 1) {
if (iobp->io_buffer[ix] == '\n')
break;
if (iobp->io_buffer[ix] == '\0') {
syslog(LOG_INFO,
"got NUL byte from %s - bye!",
iobp->who);
exit(EX_DATAERR);
}
}
if (ix == iobp->io_buffer_len) {
if (!refill_buffer(iobp))
return(0);
/*
* Empty line returned
* will try again soon!
*/
return(1);
}
/*
* Expand the line buffer if it isn't big enough. We
* use a fudge factor of 5 rather than trying to
* figure out exactly how to account for the '\0 \r\n' and
* such. The correct fudge factor is 0, 1 or 2 but
* anything higher also works. We also grow it by a
* bunch to avoid having to do this often. Yes this is
* nasty.
*/
if (ix - iobp->next_byte > iobp->line_buffer_size - 5) {
char *tmp;
iobp->line_buffer_size = 256 + ix - iobp->next_byte;
tmp = realloc(iobp->line_buffer,
iobp->line_buffer_size);
if (tmp == NULL) {
syslog(LOG_INFO, "Insufficient memory");
exit(EX_UNAVAILABLE);
}
iobp->line_buffer = tmp;
}
/* +1 is for the newline */
clen = (ix+1) - iobp->next_byte;
memcpy(iobp->line_buffer, &iobp->io_buffer[iobp->next_byte],
clen);
iobp->next_byte += clen;
iobp->line_buffer[clen] = '\0';
return(1);
}
}
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