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Annotation of src/usr.bin/telnet/network.c, Revision 1.11

1.11    ! guenther    1: /*     $OpenBSD: network.c,v 1.10 2014/07/19 23:50:38 guenther Exp $   */
1.2       niklas      2: /*     $NetBSD: network.c,v 1.5 1996/02/28 21:04:06 thorpej Exp $      */
                      3:
1.1       deraadt     4: /*
                      5:  * Copyright (c) 1988, 1993
                      6:  *     The Regents of the University of California.  All rights reserved.
                      7:  *
                      8:  * Redistribution and use in source and binary forms, with or without
                      9:  * modification, are permitted provided that the following conditions
                     10:  * are met:
                     11:  * 1. Redistributions of source code must retain the above copyright
                     12:  *    notice, this list of conditions and the following disclaimer.
                     13:  * 2. Redistributions in binary form must reproduce the above copyright
                     14:  *    notice, this list of conditions and the following disclaimer in the
                     15:  *    documentation and/or other materials provided with the distribution.
1.8       millert    16:  * 3. Neither the name of the University nor the names of its contributors
1.1       deraadt    17:  *    may be used to endorse or promote products derived from this software
                     18:  *    without specific prior written permission.
                     19:  *
                     20:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     21:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     22:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     23:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     24:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     25:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     26:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     27:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     28:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     29:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     30:  * SUCH DAMAGE.
                     31:  */
                     32:
1.5       art        33: #include "telnet_locl.h"
1.11    ! guenther   34: #include <poll.h>
1.1       deraadt    35:
                     36: Ring           netoring, netiring;
                     37: unsigned char  netobuf[2*BUFSIZ], netibuf[BUFSIZ];
                     38:
                     39: /*
                     40:  * Initialize internal network data structures.
                     41:  */
                     42:
                     43:     void
                     44: init_network()
                     45: {
                     46:     if (ring_init(&netoring, netobuf, sizeof netobuf) != 1) {
                     47:        exit(1);
                     48:     }
                     49:     if (ring_init(&netiring, netibuf, sizeof netibuf) != 1) {
                     50:        exit(1);
                     51:     }
                     52:     NetTrace = stdout;
                     53: }
                     54:
                     55:
                     56: /*
                     57:  * Check to see if any out-of-band data exists on a socket (for
                     58:  * Telnet "synch" processing).
                     59:  */
                     60:
                     61:     int
                     62: stilloob()
                     63: {
1.9       millert    64:     struct pollfd pfd[1];
1.1       deraadt    65:     int value;
                     66:
                     67:     do {
1.9       millert    68:        pfd[0].fd = net;
                     69:        pfd[0].events = POLLRDBAND;
                     70:        value = poll(pfd, 1, 0);
1.1       deraadt    71:     } while ((value == -1) && (errno == EINTR));
                     72:
                     73:     if (value < 0) {
1.9       millert    74:        perror("poll");
1.11    ! guenther   75:        quit();
1.1       deraadt    76:     }
1.9       millert    77:     if (pfd[0].revents & POLLRDBAND)
1.1       deraadt    78:        return 1;
1.9       millert    79:     else
1.1       deraadt    80:        return 0;
                     81: }
                     82:
                     83:
                     84: /*
                     85:  *  setneturg()
                     86:  *
                     87:  *     Sets "neturg" to the current location.
                     88:  */
                     89:
                     90:     void
                     91: setneturg()
                     92: {
                     93:     ring_mark(&netoring);
                     94: }
                     95:
                     96:
                     97: /*
                     98:  *  netflush
                     99:  *             Send as much data as possible to the network,
                    100:  *     handling requests for urgent data.
                    101:  *
                    102:  *             The return value indicates whether we did any
                    103:  *     useful work.
                    104:  */
                    105:
                    106:
                    107:     int
                    108: netflush()
                    109: {
1.7       mpech     110:     int n, n1;
1.1       deraadt   111:
                    112:     if ((n1 = n = ring_full_consecutive(&netoring)) > 0) {
                    113:        if (!ring_at_mark(&netoring)) {
                    114:            n = send(net, (char *)netoring.consume, n, 0); /* normal write */
                    115:        } else {
                    116:            /*
                    117:             * In 4.2 (and 4.3) systems, there is some question about
                    118:             * what byte in a sendOOB operation is the "OOB" data.
                    119:             * To make ourselves compatible, we only send ONE byte
                    120:             * out of band, the one WE THINK should be OOB (though
                    121:             * we really have more the TCP philosophy of urgent data
                    122:             * rather than the Unix philosophy of OOB data).
                    123:             */
                    124:            n = send(net, (char *)netoring.consume, 1, MSG_OOB);/* URGENT data */
                    125:        }
                    126:     }
                    127:     if (n < 0) {
                    128:        if (errno != ENOBUFS && errno != EWOULDBLOCK) {
                    129:            setcommandmode();
                    130:            perror(hostname);
                    131:            (void)NetClose(net);
                    132:            ring_clear_mark(&netoring);
                    133:            longjmp(peerdied, -1);
                    134:            /*NOTREACHED*/
                    135:        }
                    136:        n = 0;
                    137:     }
                    138:     if (netdata && n) {
                    139:        Dump('>', netoring.consume, n);
                    140:     }
                    141:     if (n) {
                    142:        ring_consumed(&netoring, n);
                    143:        /*
                    144:         * If we sent all, and more to send, then recurse to pick
                    145:         * up the other half.
                    146:         */
                    147:        if ((n1 == n) && ring_full_consecutive(&netoring)) {
                    148:            (void) netflush();
                    149:        }
                    150:        return 1;
                    151:     } else {
                    152:        return 0;
                    153:     }
                    154: }