Annotation of src/usr.bin/telnet/network.c, Revision 1.1
1.1 ! deraadt 1: /*
! 2: * Copyright (c) 1988, 1993
! 3: * The Regents of the University of California. All rights reserved.
! 4: *
! 5: * Redistribution and use in source and binary forms, with or without
! 6: * modification, are permitted provided that the following conditions
! 7: * are met:
! 8: * 1. Redistributions of source code must retain the above copyright
! 9: * notice, this list of conditions and the following disclaimer.
! 10: * 2. Redistributions in binary form must reproduce the above copyright
! 11: * notice, this list of conditions and the following disclaimer in the
! 12: * documentation and/or other materials provided with the distribution.
! 13: * 3. All advertising materials mentioning features or use of this software
! 14: * must display the following acknowledgement:
! 15: * This product includes software developed by the University of
! 16: * California, Berkeley and its contributors.
! 17: * 4. Neither the name of the University nor the names of its contributors
! 18: * may be used to endorse or promote products derived from this software
! 19: * without specific prior written permission.
! 20: *
! 21: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 22: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 23: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 24: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 25: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 26: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 27: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 28: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 29: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 30: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 31: * SUCH DAMAGE.
! 32: */
! 33:
! 34: #ifndef lint
! 35: /* from: static char sccsid[] = "@(#)network.c 8.1 (Berkeley) 6/6/93"; */
! 36: static char *rcsid = "$Id: network.c,v 1.3 1994/02/25 03:00:31 cgd Exp $";
! 37: #endif /* not lint */
! 38:
! 39: #include <sys/types.h>
! 40: #include <sys/socket.h>
! 41: #include <sys/time.h>
! 42:
! 43: #include <errno.h>
! 44:
! 45: #include <arpa/telnet.h>
! 46:
! 47: #include "ring.h"
! 48:
! 49: #include "defines.h"
! 50: #include "externs.h"
! 51: #include "fdset.h"
! 52:
! 53: Ring netoring, netiring;
! 54: unsigned char netobuf[2*BUFSIZ], netibuf[BUFSIZ];
! 55:
! 56: /*
! 57: * Initialize internal network data structures.
! 58: */
! 59:
! 60: void
! 61: init_network()
! 62: {
! 63: if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
! 64: exit(1);
! 65: }
! 66: if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
! 67: exit(1);
! 68: }
! 69: NetTrace = stdout;
! 70: }
! 71:
! 72:
! 73: /*
! 74: * Check to see if any out-of-band data exists on a socket (for
! 75: * Telnet "synch" processing).
! 76: */
! 77:
! 78: int
! 79: stilloob()
! 80: {
! 81: static struct timeval timeout = { 0 };
! 82: fd_set excepts;
! 83: int value;
! 84:
! 85: do {
! 86: FD_ZERO(&excepts);
! 87: FD_SET(net, &excepts);
! 88: value = select(net+1, (fd_set *)0, (fd_set *)0, &excepts, &timeout);
! 89: } while ((value == -1) && (errno == EINTR));
! 90:
! 91: if (value < 0) {
! 92: perror("select");
! 93: (void) quit();
! 94: /* NOTREACHED */
! 95: }
! 96: if (FD_ISSET(net, &excepts)) {
! 97: return 1;
! 98: } else {
! 99: return 0;
! 100: }
! 101: }
! 102:
! 103:
! 104: /*
! 105: * setneturg()
! 106: *
! 107: * Sets "neturg" to the current location.
! 108: */
! 109:
! 110: void
! 111: setneturg()
! 112: {
! 113: ring_mark(&netoring);
! 114: }
! 115:
! 116:
! 117: /*
! 118: * netflush
! 119: * Send as much data as possible to the network,
! 120: * handling requests for urgent data.
! 121: *
! 122: * The return value indicates whether we did any
! 123: * useful work.
! 124: */
! 125:
! 126:
! 127: int
! 128: netflush()
! 129: {
! 130: register int n, n1;
! 131:
! 132: if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
! 133: if (!ring_at_mark(&netoring)) {
! 134: n = send(net, (char *)netoring.consume, n, 0); /* normal write */
! 135: } else {
! 136: /*
! 137: * In 4.2 (and 4.3) systems, there is some question about
! 138: * what byte in a sendOOB operation is the "OOB" data.
! 139: * To make ourselves compatible, we only send ONE byte
! 140: * out of band, the one WE THINK should be OOB (though
! 141: * we really have more the TCP philosophy of urgent data
! 142: * rather than the Unix philosophy of OOB data).
! 143: */
! 144: n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
! 145: }
! 146: }
! 147: if (n < 0) {
! 148: if (errno != ENOBUFS && errno != EWOULDBLOCK) {
! 149: setcommandmode();
! 150: perror(hostname);
! 151: (void)NetClose(net);
! 152: ring_clear_mark(&netoring);
! 153: longjmp(peerdied, -1);
! 154: /*NOTREACHED*/
! 155: }
! 156: n = 0;
! 157: }
! 158: if (netdata && n) {
! 159: Dump('>', netoring.consume, n);
! 160: }
! 161: if (n) {
! 162: ring_consumed(&netoring, n);
! 163: /*
! 164: * If we sent all, and more to send, then recurse to pick
! 165: * up the other half.
! 166: */
! 167: if ((n1 == n) && ring_full_consecutive(&netoring)) {
! 168: (void) netflush();
! 169: }
! 170: return 1;
! 171: } else {
! 172: return 0;
! 173: }
! 174: }