Annotation of 43BSDTahoe/ucb/telnet/Source/sys_bsd.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * Copyright (c) 1988 Regents of the University of California.
        !             3:  * All rights reserved.
        !             4:  *
        !             5:  * Redistribution and use in source and binary forms are permitted
        !             6:  * provided that this notice is preserved and that due credit is given
        !             7:  * to the University of California at Berkeley. The name of the University
        !             8:  * may not be used to endorse or promote products derived from this
        !             9:  * software without specific prior written permission. This software
        !            10:  * is provided ``as is'' without express or implied warranty.
        !            11:  */
        !            12: 
        !            13: #ifndef lint
        !            14: static char sccsid[] = "@(#)sys_bsd.c  1.11 (Berkeley) 3/27/88";
        !            15: #endif /* not lint */
        !            16: 
        !            17: /*
        !            18:  * The following routines try to encapsulate what is system dependent
        !            19:  * (at least between 4.x and dos) which is used in telnet.c.
        !            20:  */
        !            21: 
        !            22: #if    defined(unix)
        !            23: 
        !            24: #include <sys/ioctl.h>
        !            25: #include <sys/types.h>
        !            26: #include <sys/time.h>
        !            27: #include <sys/socket.h>
        !            28: #include <signal.h>
        !            29: #include <errno.h>
        !            30: 
        !            31: #include "ring.h"
        !            32: 
        !            33: #include "fdset.h"
        !            34: 
        !            35: #include "defines.h"
        !            36: #include "externs.h"
        !            37: #include "types.h"
        !            38: 
        !            39: int
        !            40:        tout,                   /* Output file descriptor */
        !            41:        tin,                    /* Input file descriptor */
        !            42:        net,
        !            43:        HaveInput;              /* There is input available to scan */
        !            44: 
        !            45: static struct  tchars otc = { 0 }, ntc = { 0 };
        !            46: static struct  ltchars oltc = { 0 }, nltc = { 0 };
        !            47: static struct  sgttyb ottyb = { 0 }, nttyb = { 0 };
        !            48: 
        !            49: static fd_set ibits, obits, xbits;
        !            50: 
        !            51: 
        !            52: init_sys()
        !            53: {
        !            54:     tout = fileno(stdout);
        !            55:     tin = fileno(stdin);
        !            56:     FD_ZERO(&ibits);
        !            57:     FD_ZERO(&obits);
        !            58:     FD_ZERO(&xbits);
        !            59: 
        !            60:     errno = 0;
        !            61: }
        !            62: 
        !            63: 
        !            64: TerminalWrite(buf, n)
        !            65: char   *buf;
        !            66: int    n;
        !            67: {
        !            68:     return write(tout, buf, n);
        !            69: }
        !            70: 
        !            71: TerminalRead(buf, n)
        !            72: char   *buf;
        !            73: int    n;
        !            74: {
        !            75:     return read(tin, buf, n);
        !            76: }
        !            77: 
        !            78: /*
        !            79:  *
        !            80:  */
        !            81: 
        !            82: int
        !            83: TerminalAutoFlush()
        !            84: {
        !            85: #if    defined(LNOFLSH)
        !            86:     int flush;
        !            87: 
        !            88:     ioctl(0, TIOCLGET, (char *)&flush);
        !            89:     return !(flush&LNOFLSH);   /* if LNOFLSH, no autoflush */
        !            90: #else  /* LNOFLSH */
        !            91:     return 1;
        !            92: #endif /* LNOFLSH */
        !            93: }
        !            94: 
        !            95: /*
        !            96:  * TerminalSpecialChars()
        !            97:  *
        !            98:  * Look at an input character to see if it is a special character
        !            99:  * and decide what to do.
        !           100:  *
        !           101:  * Output:
        !           102:  *
        !           103:  *     0       Don't add this character.
        !           104:  *     1       Do add this character
        !           105:  */
        !           106: 
        !           107: int
        !           108: TerminalSpecialChars(c)
        !           109: int    c;
        !           110: {
        !           111:     void xmitAO(), xmitEL(), xmitEC(), intp(), sendbrk();
        !           112: 
        !           113:     if (c == ntc.t_intrc) {
        !           114:        intp();
        !           115:        return 0;
        !           116:     } else if (c == ntc.t_quitc) {
        !           117:        sendbrk();
        !           118:        return 0;
        !           119:     } else if (c == nltc.t_flushc) {
        !           120:        xmitAO();               /* Transmit Abort Output */
        !           121:        return 0;
        !           122:     } else if (!MODE_LOCAL_CHARS(globalmode)) {
        !           123:        if (c == nttyb.sg_kill) {
        !           124:            xmitEL();
        !           125:            return 0;
        !           126:        } else if (c == nttyb.sg_erase) {
        !           127:            xmitEC();           /* Transmit Erase Character */
        !           128:            return 0;
        !           129:        }
        !           130:     }
        !           131:     return 1;
        !           132: }
        !           133: 
        !           134: 
        !           135: /*
        !           136:  * Flush output to the terminal
        !           137:  */
        !           138:  
        !           139: void
        !           140: TerminalFlushOutput()
        !           141: {
        !           142:     (void) ioctl(fileno(stdout), TIOCFLUSH, (char *) 0);
        !           143: }
        !           144: 
        !           145: void
        !           146: TerminalSaveState()
        !           147: {
        !           148:     ioctl(0, TIOCGETP, (char *)&ottyb);
        !           149:     ioctl(0, TIOCGETC, (char *)&otc);
        !           150:     ioctl(0, TIOCGLTC, (char *)&oltc);
        !           151: 
        !           152:     ntc = otc;
        !           153:     nltc = oltc;
        !           154:     nttyb = ottyb;
        !           155: 
        !           156:     termEofChar = ntc.t_eofc;
        !           157:     termEraseChar = nttyb.sg_erase;
        !           158:     termFlushChar = nltc.t_flushc;
        !           159:     termIntChar = ntc.t_intrc;
        !           160:     termKillChar = nttyb.sg_kill;
        !           161:     termQuitChar = ntc.t_quitc;
        !           162: }
        !           163: 
        !           164: void
        !           165: TerminalRestoreState()
        !           166: {
        !           167: }
        !           168: 
        !           169: /*
        !           170:  * TerminalNewMode - set up terminal to a specific mode.
        !           171:  */
        !           172: 
        !           173: 
        !           174: void
        !           175: TerminalNewMode(f)
        !           176: register int f;
        !           177: {
        !           178:     static int prevmode = 0;
        !           179:     struct tchars *tc;
        !           180:     struct tchars tc3;
        !           181:     struct ltchars *ltc;
        !           182:     struct sgttyb sb;
        !           183:     int onoff;
        !           184:     int old;
        !           185:     struct     tchars notc2;
        !           186:     struct     ltchars noltc2;
        !           187:     static struct      tchars notc =   { -1, -1, -1, -1, -1, -1 };
        !           188:     static struct      ltchars noltc = { -1, -1, -1, -1, -1, -1 };
        !           189: 
        !           190:     globalmode = f;
        !           191:     if (prevmode == f)
        !           192:        return;
        !           193:     old = prevmode;
        !           194:     prevmode = f;
        !           195:     sb = nttyb;
        !           196: 
        !           197:     switch (f) {
        !           198: 
        !           199:     case 0:
        !           200:        onoff = 0;
        !           201:        tc = &otc;
        !           202:        ltc = &oltc;
        !           203:        break;
        !           204: 
        !           205:     case 1:            /* remote character processing, remote echo */
        !           206:     case 2:            /* remote character processing, local echo */
        !           207:     case 6:            /* 3270 mode - like 1, but with xon/xoff local */
        !           208:                    /* (might be nice to have "6" in telnet also...) */
        !           209:            sb.sg_flags |= CBREAK;
        !           210:            if ((f == 1) || (f == 6)) {
        !           211:                sb.sg_flags &= ~(ECHO|CRMOD);
        !           212:            } else {
        !           213:                sb.sg_flags |= ECHO|CRMOD;
        !           214:            }
        !           215:            sb.sg_erase = sb.sg_kill = -1;
        !           216:            if (f == 6) {
        !           217:                tc = &tc3;
        !           218:                tc3 = notc;
        !           219:                    /* get XON, XOFF characters */
        !           220:                tc3.t_startc = otc.t_startc;
        !           221:                tc3.t_stopc = otc.t_stopc;
        !           222:            } else {
        !           223:                /*
        !           224:                 * If user hasn't specified one way or the other,
        !           225:                 * then default to not trapping signals.
        !           226:                 */
        !           227:                if (!donelclchars) {
        !           228:                    localchars = 0;
        !           229:                }
        !           230:                if (localchars) {
        !           231:                    notc2 = notc;
        !           232:                    notc2.t_intrc = ntc.t_intrc;
        !           233:                    notc2.t_quitc = ntc.t_quitc;
        !           234:                    tc = &notc2;
        !           235:                } else {
        !           236:                    tc = &notc;
        !           237:                }
        !           238:            }
        !           239:            ltc = &noltc;
        !           240:            onoff = 1;
        !           241:            break;
        !           242:     case 3:            /* local character processing, remote echo */
        !           243:     case 4:            /* local character processing, local echo */
        !           244:     case 5:            /* local character processing, no echo */
        !           245:            sb.sg_flags &= ~CBREAK;
        !           246:            sb.sg_flags |= CRMOD;
        !           247:            if (f == 4)
        !           248:                sb.sg_flags |= ECHO;
        !           249:            else
        !           250:                sb.sg_flags &= ~ECHO;
        !           251:            notc2 = ntc;
        !           252:            tc = &notc2;
        !           253:            noltc2 = oltc;
        !           254:            ltc = &noltc2;
        !           255:            /*
        !           256:             * If user hasn't specified one way or the other,
        !           257:             * then default to trapping signals.
        !           258:             */
        !           259:            if (!donelclchars) {
        !           260:                localchars = 1;
        !           261:            }
        !           262:            if (localchars) {
        !           263:                notc2.t_brkc = nltc.t_flushc;
        !           264:                noltc2.t_flushc = -1;
        !           265:            } else {
        !           266:                notc2.t_intrc = notc2.t_quitc = -1;
        !           267:            }
        !           268:            noltc2.t_suspc = escape;
        !           269:            noltc2.t_dsuspc = -1;
        !           270:            onoff = 1;
        !           271:            break;
        !           272: 
        !           273:     default:
        !           274:            return;
        !           275:     }
        !           276:     ioctl(tin, TIOCSLTC, (char *)ltc);
        !           277:     ioctl(tin, TIOCSETC, (char *)tc);
        !           278:     ioctl(tin, TIOCSETP, (char *)&sb);
        !           279: #if    (!defined(TN3270)) || ((!defined(NOT43)) || defined(PUTCHAR))
        !           280:     ioctl(tin, FIONBIO, (char *)&onoff);
        !           281:     ioctl(tout, FIONBIO, (char *)&onoff);
        !           282: #endif /* (!defined(TN3270)) || ((!defined(NOT43)) || defined(PUTCHAR)) */
        !           283: #if    defined(TN3270)
        !           284:     if (noasynch == 0) {
        !           285:        ioctl(tin, FIOASYNC, (char *)&onoff);
        !           286:     }
        !           287: #endif /* defined(TN3270) */
        !           288: 
        !           289:     if (MODE_LINE(f)) {
        !           290:        void doescape();
        !           291: 
        !           292:        signal(SIGTSTP, doescape);
        !           293:     } else if (MODE_LINE(old)) {
        !           294:        signal(SIGTSTP, SIG_DFL);
        !           295:        sigsetmask(sigblock(0) & ~(1<<(SIGTSTP-1)));
        !           296:     }
        !           297: }
        !           298: 
        !           299: 
        !           300: int
        !           301: NetClose(net)
        !           302: int    net;
        !           303: {
        !           304:     return close(net);
        !           305: }
        !           306: 
        !           307: 
        !           308: void
        !           309: NetNonblockingIO(fd, onoff)
        !           310: int
        !           311:        fd,
        !           312:        onoff;
        !           313: {
        !           314:     ioctl(fd, FIONBIO, (char *)&onoff);
        !           315: }
        !           316: 
        !           317: void
        !           318: NetSigIO(fd, onoff)
        !           319: int
        !           320:        fd,
        !           321:        onoff;
        !           322: {
        !           323:     ioctl(fd, FIOASYNC, (char *)&onoff);       /* hear about input */
        !           324: }
        !           325: 
        !           326: void
        !           327: NetSetPgrp(fd)
        !           328: int fd;
        !           329: {
        !           330:     int myPid;
        !           331: 
        !           332:     myPid = getpid();
        !           333: #if    defined(NOT43)
        !           334:     myPid = -myPid;
        !           335: #endif /* defined(NOT43) */
        !           336:     ioctl(fd, SIOCSPGRP, (char *)&myPid);      /* set my pid */
        !           337: }
        !           338: 
        !           339: /*
        !           340:  * Various signal handling routines.
        !           341:  */
        !           342: 
        !           343: static void
        !           344: deadpeer()
        !           345: {
        !           346:        setcommandmode();
        !           347:        longjmp(peerdied, -1);
        !           348: }
        !           349: 
        !           350: static void
        !           351: intr()
        !           352: {
        !           353:     if (localchars) {
        !           354:        intp();
        !           355:        return;
        !           356:     }
        !           357:     setcommandmode();
        !           358:     longjmp(toplevel, -1);
        !           359: }
        !           360: 
        !           361: static void
        !           362: intr2()
        !           363: {
        !           364:     if (localchars) {
        !           365:        sendbrk();
        !           366:        return;
        !           367:     }
        !           368: }
        !           369: 
        !           370: static void
        !           371: doescape()
        !           372: {
        !           373:     command(0);
        !           374: }
        !           375: 
        !           376: void
        !           377: sys_telnet_init()
        !           378: {
        !           379: #if    defined(TN3270)
        !           380:     int myPid;
        !           381: #endif /* defined(TN3270) */
        !           382: 
        !           383:     signal(SIGINT, intr);
        !           384:     signal(SIGQUIT, intr2);
        !           385:     signal(SIGPIPE, deadpeer);
        !           386: 
        !           387:     setconnmode();
        !           388: 
        !           389:     NetNonblockingIO(net, 1);
        !           390: 
        !           391: #if    defined(TN3270)
        !           392:     if (noasynch == 0) {                       /* DBX can't handle! */
        !           393:        NetSigIO(net, 1);
        !           394:        NetSetPgrp(net);
        !           395:     }
        !           396: #endif /* defined(TN3270) */
        !           397: 
        !           398: #if    defined(SO_OOBINLINE)
        !           399:     SetSockOpt(net, SOL_SOCKET, SO_OOBINLINE, 1);
        !           400: #endif /* defined(SO_OOBINLINE) */
        !           401: }
        !           402: 
        !           403: /*
        !           404:  * Process rings -
        !           405:  *
        !           406:  *     This routine tries to fill up/empty our various rings.
        !           407:  *
        !           408:  *     The parameter specifies whether this is a poll operation,
        !           409:  *     or a block-until-something-happens operation.
        !           410:  *
        !           411:  *     The return value is 1 if something happened, 0 if not.
        !           412:  */
        !           413: 
        !           414: int
        !           415: process_rings(netin, netout, netex, ttyin, ttyout, poll)
        !           416: int poll;              /* If 0, then block until something to do */
        !           417: {
        !           418:     register int c;
        !           419:                /* One wants to be a bit careful about setting returnValue
        !           420:                 * to one, since a one implies we did some useful work,
        !           421:                 * and therefore probably won't be called to block next
        !           422:                 * time (TN3270 mode only).
        !           423:                 */
        !           424:     int returnValue = 0;
        !           425:     static struct timeval TimeValue = { 0 };
        !           426: 
        !           427:     if (netout) {
        !           428:        FD_SET(net, &obits);
        !           429:     } 
        !           430:     if (ttyout) {
        !           431:        FD_SET(tout, &obits);
        !           432:     }
        !           433: #if    defined(TN3270)
        !           434:     if (ttyin) {
        !           435:        FD_SET(tin, &ibits);
        !           436:     }
        !           437: #else  /* defined(TN3270) */
        !           438:     if (ttyin) {
        !           439:        FD_SET(tin, &ibits);
        !           440:     }
        !           441: #endif /* defined(TN3270) */
        !           442: #if    defined(TN3270)
        !           443:     if (netin) {
        !           444:        FD_SET(net, &ibits);
        !           445:     }
        !           446: #   else /* !defined(TN3270) */
        !           447:     if (netin) {
        !           448:        FD_SET(net, &ibits);
        !           449:     }
        !           450: #   endif /* !defined(TN3270) */
        !           451:     if (netex) {
        !           452:        FD_SET(net, &xbits);
        !           453:     }
        !           454:     if ((c = select(16, &ibits, &obits, &xbits,
        !           455:                        (poll == 0)? (struct timeval *)0 : &TimeValue)) < 0) {
        !           456:        if (c == -1) {
        !           457:                    /*
        !           458:                     * we can get EINTR if we are in line mode,
        !           459:                     * and the user does an escape (TSTP), or
        !           460:                     * some other signal generator.
        !           461:                     */
        !           462:            if (errno == EINTR) {
        !           463:                return 0;
        !           464:            }
        !           465: #          if defined(TN3270)
        !           466:                    /*
        !           467:                     * we can get EBADF if we were in transparent
        !           468:                     * mode, and the transcom process died.
        !           469:                    */
        !           470:            if (errno == EBADF) {
        !           471:                        /*
        !           472:                         * zero the bits (even though kernel does it)
        !           473:                         * to make sure we are selecting on the right
        !           474:                         * ones.
        !           475:                        */
        !           476:                FD_ZERO(&ibits);
        !           477:                FD_ZERO(&obits);
        !           478:                FD_ZERO(&xbits);
        !           479:                return 0;
        !           480:            }
        !           481: #          endif /* defined(TN3270) */
        !           482:                    /* I don't like this, does it ever happen? */
        !           483:            printf("sleep(5) from telnet, after select\r\n");
        !           484:            sleep(5);
        !           485:        }
        !           486:        return 0;
        !           487:     }
        !           488: 
        !           489:     /*
        !           490:      * Any urgent data?
        !           491:      */
        !           492:     if (FD_ISSET(net, &xbits)) {
        !           493:        FD_CLR(net, &xbits);
        !           494:        SYNCHing = 1;
        !           495:        ttyflush(1);    /* flush already enqueued data */
        !           496:     }
        !           497: 
        !           498:     /*
        !           499:      * Something to read from the network...
        !           500:      */
        !           501:     if (FD_ISSET(net, &ibits)) {
        !           502:        int canread;
        !           503: 
        !           504:        FD_CLR(net, &ibits);
        !           505:        canread = ring_empty_consecutive(&netiring);
        !           506: #if    !defined(SO_OOBINLINE)
        !           507:            /*
        !           508:             * In 4.2 (and some early 4.3) systems, the
        !           509:             * OOB indication and data handling in the kernel
        !           510:             * is such that if two separate TCP Urgent requests
        !           511:             * come in, one byte of TCP data will be overlaid.
        !           512:             * This is fatal for Telnet, but we try to live
        !           513:             * with it.
        !           514:             *
        !           515:             * In addition, in 4.2 (and...), a special protocol
        !           516:             * is needed to pick up the TCP Urgent data in
        !           517:             * the correct sequence.
        !           518:             *
        !           519:             * What we do is:  if we think we are in urgent
        !           520:             * mode, we look to see if we are "at the mark".
        !           521:             * If we are, we do an OOB receive.  If we run
        !           522:             * this twice, we will do the OOB receive twice,
        !           523:             * but the second will fail, since the second
        !           524:             * time we were "at the mark", but there wasn't
        !           525:             * any data there (the kernel doesn't reset
        !           526:             * "at the mark" until we do a normal read).
        !           527:             * Once we've read the OOB data, we go ahead
        !           528:             * and do normal reads.
        !           529:             *
        !           530:             * There is also another problem, which is that
        !           531:             * since the OOB byte we read doesn't put us
        !           532:             * out of OOB state, and since that byte is most
        !           533:             * likely the TELNET DM (data mark), we would
        !           534:             * stay in the TELNET SYNCH (SYNCHing) state.
        !           535:             * So, clocks to the rescue.  If we've "just"
        !           536:             * received a DM, then we test for the
        !           537:             * presence of OOB data when the receive OOB
        !           538:             * fails (and AFTER we did the normal mode read
        !           539:             * to clear "at the mark").
        !           540:             */
        !           541:        if (SYNCHing) {
        !           542:            int atmark;
        !           543: 
        !           544:            ioctl(net, SIOCATMARK, (char *)&atmark);
        !           545:            if (atmark) {
        !           546:                c = recv(net, netiring.supply, canread, MSG_OOB);
        !           547:                if ((c == -1) && (errno == EINVAL)) {
        !           548:                    c = recv(net, netiring.supply, canread, 0);
        !           549:                    if (clocks.didnetreceive < clocks.gotDM) {
        !           550:                        SYNCHing = stilloob(net);
        !           551:                    }
        !           552:                }
        !           553:            } else {
        !           554:                c = recv(net, netiring.supply, canread, 0);
        !           555:            }
        !           556:        } else {
        !           557:            c = recv(net, netiring.supply, canread, 0);
        !           558:        }
        !           559:        settimer(didnetreceive);
        !           560: #else  /* !defined(SO_OOBINLINE) */
        !           561:        c = recv(net, netiring.supply, canread, 0);
        !           562: #endif /* !defined(SO_OOBINLINE) */
        !           563:        if (c < 0 && errno == EWOULDBLOCK) {
        !           564:            c = 0;
        !           565:        } else if (c <= 0) {
        !           566:            return -1;
        !           567:        }
        !           568:        if (netdata) {
        !           569:            Dump('<', netiring.supply, c);
        !           570:        }
        !           571:        if (c)
        !           572:            ring_supplied(&netiring, c);
        !           573:        returnValue = 1;
        !           574:     }
        !           575: 
        !           576:     /*
        !           577:      * Something to read from the tty...
        !           578:      */
        !           579:     if (FD_ISSET(tin, &ibits)) {
        !           580:        FD_CLR(tin, &ibits);
        !           581:        c = TerminalRead(ttyiring.supply, ring_empty_consecutive(&ttyiring));
        !           582:        if (c < 0 && errno == EWOULDBLOCK) {
        !           583:            c = 0;
        !           584:        } else {
        !           585:            /* EOF detection for line mode!!!! */
        !           586:            if ((c == 0) && MODE_LOCAL_CHARS(globalmode) && isatty(tin)) {
        !           587:                        /* must be an EOF... */
        !           588:                *ttyiring.supply = termEofChar;
        !           589:                c = 1;
        !           590:            }
        !           591:            if (c <= 0) {
        !           592:                return -1;
        !           593:            }
        !           594:            ring_supplied(&ttyiring, c);
        !           595:        }
        !           596:        returnValue = 1;                /* did something useful */
        !           597:     }
        !           598: 
        !           599:     if (FD_ISSET(net, &obits)) {
        !           600:        FD_CLR(net, &obits);
        !           601:        returnValue |= netflush();
        !           602:     }
        !           603:     if (FD_ISSET(tout, &obits)) {
        !           604:        FD_CLR(tout, &obits);
        !           605:        returnValue |= ttyflush(SYNCHing|flushout);
        !           606:     }
        !           607: 
        !           608:     return returnValue;
        !           609: }
        !           610: #endif /* defined(unix) */

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