telnetd/telnet/network.c

183 lines
4.6 KiB
C

/*
* Copyright (c) 1988, 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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.
*/
#if 0
#ifndef lint
static const char sccsid[] = "@(#)network.c 8.2 (Berkeley) 12/15/93";
#endif
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <errno.h>
#include <stdlib.h>
#include <arpa/telnet.h>
#include <unistd.h>
#include "ring.h"
#include "defines.h"
#include "externs.h"
#include "fdset.h"
Ring netoring, netiring;
unsigned char netobuf[2*BUFSIZ], netibuf[BUFSIZ];
/*
* Initialize internal network data structures.
*/
void
init_network(void)
{
if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
exit(1);
}
if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
exit(1);
}
NetTrace = stdout;
}
/*
* Check to see if any out-of-band data exists on a socket (for
* Telnet "synch" processing).
*/
int
stilloob(void)
{
static struct timeval timeout = { 0, 0 };
fd_set excepts;
int value;
do {
FD_ZERO(&excepts);
FD_SET(net, &excepts);
value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
} while ((value == -1) && (errno == EINTR));
if (value < 0) {
perror("select");
(void) quit();
/* NOTREACHED */
}
if (FD_ISSET(net, &excepts)) {
return 1;
} else {
return 0;
}
}
/*
* setneturg()
*
* Sets "neturg" to the current location.
*/
void
setneturg(void)
{
ring_mark(&netoring);
}
/*
* netflush
* Send as much data as possible to the network,
* handling requests for urgent data.
*
* The return value indicates whether we did any
* useful work.
*/
int
netflush(void)
{
int n, n1;
#ifdef ENCRYPTION
if (encrypt_output)
ring_encrypt(&netoring, encrypt_output);
#endif /* ENCRYPTION */
if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
if (!ring_at_mark(&netoring)) {
n = send(net, (char *)netoring.consume, n, 0); /* normal write */
} else {
/*
* In 4.2 (and 4.3) systems, there is some question about
* what byte in a sendOOB operation is the "OOB" data.
* To make ourselves compatible, we only send ONE byte
* out of band, the one WE THINK should be OOB (though
* we really have more the TCP philosophy of urgent data
* rather than the Unix philosophy of OOB data).
*/
n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
}
}
if (n < 0) {
if (errno != ENOBUFS && errno != EWOULDBLOCK) {
setcommandmode();
perror(hostname);
(void)NetClose(net);
ring_clear_mark(&netoring);
longjmp(peerdied, -1);
/*NOTREACHED*/
}
n = 0;
}
if (netdata && n) {
Dump('>', netoring.consume, n);
}
if (n) {
ring_consumed(&netoring, n);
/*
* If we sent all, and more to send, then recurse to pick
* up the other half.
*/
if ((n1 == n) && ring_full_consecutive(&netoring)) {
(void) netflush();
}
return 1;
} else {
return 0;
}
}