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Annotation of 43BSDReno/usr.bin/tn3270/api/api_exch.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 the above copyright notice and this paragraph are
        !             7:  * duplicated in all such forms and that any documentation,
        !             8:  * advertising materials, and other materials related to such
        !             9:  * distribution and use acknowledge that the software was developed
        !            10:  * by the University of California, Berkeley.  The name of the
        !            11:  * University may not be used to endorse or promote products derived
        !            12:  * from this software without specific prior written permission.
        !            13:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
        !            14:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
        !            15:  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
        !            16:  */
        !            17: 
        !            18: #ifndef lint
        !            19: static char sccsid[] = "@(#)api_exch.c 4.1 (Berkeley) 12/4/88";
        !            20: #endif /* not lint */
        !            21: 
        !            22: #include <stdio.h>
        !            23: 
        !            24: #include "../general/general.h"
        !            25: 
        !            26: #include "api_exch.h"
        !            27: 
        !            28: static int sock;               /* Socket number */
        !            29: 
        !            30: static char whoarewe[40] = "";
        !            31: #define        WHO_ARE_WE()    fprintf(stderr, "(API %s) ", whoarewe);
        !            32: 
        !            33: static enum {CONTENTION, SEND, RECEIVE } conversation;
        !            34: 
        !            35: static struct exch_exch exch_state;
        !            36: 
        !            37: static unsigned int
        !            38:     my_sequence,
        !            39:     your_sequence;
        !            40: 
        !            41: static char ibuffer[4000], *ibuf_next, *ibuf_last;
        !            42: #define        IBUFADDED(i)            ibuf_last += (i)
        !            43: #define        IBUFAVAILABLE()         (ibuf_last-ibuf_next)
        !            44: #define        IBUFFER()               ibuffer
        !            45: #define        IBUFFREE()              (ibuffer+sizeof ibuffer-ibuf_last-1)
        !            46: #define        IBUFGETBYTES(w,l)       { memcpy(w, ibuf_next, l); ibuf_next += l; }
        !            47: #define        IBUFRESET()             (ibuf_next = ibuf_last = ibuffer)
        !            48: 
        !            49: char obuffer[4000], *obuf_next;
        !            50: #define        OBUFADDBYTES(w,l)       { memcpy(obuf_next, w, l); obuf_next += l; }
        !            51: #define        OBUFAVAILABLE()         (obuf_next - obuffer)
        !            52: #define        OBUFFER()               obuffer
        !            53: #define        OBUFRESET()             obuf_next = obuffer
        !            54: #define        OBUFROOM()              (obuffer+sizeof obuffer-obuf_next)
        !            55: 
        !            56: 
        !            57: static int
        !            58: outflush()
        !            59: {
        !            60:     int length = OBUFAVAILABLE();
        !            61: 
        !            62:     if (length != 0) {
        !            63:        if (write(sock, OBUFFER(), length) != length) {
        !            64:            WHO_ARE_WE();
        !            65:            perror("write");
        !            66:            return -1;
        !            67:        }
        !            68:        OBUFRESET();
        !            69:     }
        !            70:     return 0;                          /* All OK */
        !            71: }
        !            72: 
        !            73: 
        !            74: static int
        !            75: iget(location, length)
        !            76: char   *location;
        !            77: int    length;
        !            78: {
        !            79:     int count;
        !            80: 
        !            81:     if (OBUFAVAILABLE()) {
        !            82:        if (outflush() == -1) {
        !            83:            return -1;
        !            84:        }
        !            85:     }
        !            86:     if ((count = IBUFAVAILABLE()) != 0) {
        !            87:        if (count > length) {
        !            88:            count = length;
        !            89:        }
        !            90:        IBUFGETBYTES(location, count);
        !            91:        length -= count;
        !            92:        location += count;
        !            93:     }
        !            94:     while (length) {
        !            95:        if (ibuf_next == ibuf_last) {
        !            96:            IBUFRESET();
        !            97:        }
        !            98:        if ((count = read(sock, IBUFFER(), IBUFFREE())) < 0) {
        !            99:            WHO_ARE_WE();
        !           100:            perror("read");
        !           101:            return -1;
        !           102:        }
        !           103:        if (count == 0) {
        !           104:            /* Reading past end-of-file */
        !           105:            WHO_ARE_WE();
        !           106:            fprintf(stderr, "End of file read\r\n");
        !           107:            return -1;
        !           108:        }
        !           109:        IBUFADDED(count);
        !           110:        if (count > length) {
        !           111:            count = length;
        !           112:        }
        !           113:        IBUFGETBYTES(location, count);
        !           114:        length -= count;
        !           115:        location += count;
        !           116:     }
        !           117:     return 0;
        !           118: }
        !           119: 
        !           120: static char *
        !           121: exch_to_ascii(exch)
        !           122: int exch;                      /* opcode to decode */
        !           123: {
        !           124:     switch (exch) {
        !           125:     case EXCH_EXCH_COMMAND:
        !           126:        return "Command";
        !           127:     case EXCH_EXCH_TYPE:
        !           128:        return "Type";
        !           129:     case EXCH_EXCH_TURNAROUND:
        !           130:        return "Turnaround";
        !           131:     case EXCH_EXCH_RTS:
        !           132:        return "Request to Send";
        !           133:     default:
        !           134:        {
        !           135:            static char unknown[40];
        !           136: 
        !           137:            sprintf(unknown, "(Unknown exchange 0x%02x)", exch&0xff);
        !           138:            return unknown;
        !           139:        }
        !           140:     }
        !           141: }
        !           142: 
        !           143: /*
        !           144:  * Send the exch structure, updating the sequnce number field.
        !           145:  */
        !           146: 
        !           147: static int
        !           148: send_state()
        !           149: {
        !           150:     if (OBUFROOM() < sizeof exch_state) {
        !           151:        if (outflush() == -1) {
        !           152:            return -1;
        !           153:        }
        !           154:     }
        !           155:     my_sequence = (my_sequence+1)&0xff;
        !           156:     exch_state.my_sequence = my_sequence;
        !           157:     exch_state.your_sequence = your_sequence;
        !           158:     OBUFADDBYTES((char *)&exch_state, sizeof exch_state);
        !           159:     return 0;
        !           160: }
        !           161: 
        !           162: /*
        !           163:  * Receive the exch structure from the other side, checking
        !           164:  * sequence numbering.
        !           165:  */
        !           166: 
        !           167: static int
        !           168: receive_state()
        !           169: {
        !           170:     if (iget((char *)&exch_state, sizeof exch_state) == -1) {
        !           171:        return -1;
        !           172:     }
        !           173:     if (conversation != CONTENTION) {
        !           174:        if (exch_state.your_sequence != my_sequence) {
        !           175:            WHO_ARE_WE();
        !           176:            fprintf(stderr, "Send sequence number mismatch.\n");
        !           177:            return -1;
        !           178:        }
        !           179:        if (exch_state.my_sequence != ((++your_sequence)&0xff)) {
        !           180:            WHO_ARE_WE();
        !           181:            fprintf(stderr, "Receive sequence number mismatch.\n");
        !           182:            return -1;
        !           183:        }
        !           184:     }
        !           185:     your_sequence = exch_state.my_sequence;
        !           186:     return 0;
        !           187: }
        !           188: 
        !           189: static int
        !           190: enter_receive()
        !           191: {
        !           192:     switch (conversation) {
        !           193:     case CONTENTION:
        !           194:        exch_state.opcode = EXCH_EXCH_TURNAROUND;
        !           195:        if (send_state() == -1) {
        !           196:            return -1;
        !           197:        }
        !           198:        if (receive_state() == -1) {
        !           199:            return -1;
        !           200:        }
        !           201:        if (exch_state.opcode != EXCH_EXCH_RTS) {
        !           202:            WHO_ARE_WE();
        !           203:            fprintf(stderr, "In CONTENTION state:  ");
        !           204:            if (exch_state.opcode == EXCH_EXCH_TURNAROUND) {
        !           205:                fprintf(stderr,
        !           206:                    "Both sides tried to enter RECEIVE state.\n");
        !           207:            } else {
        !           208:                fprintf(stderr,
        !           209:                    "Protocol error trying to enter RECEIVE state.\n");
        !           210:            }
        !           211:            return -1;
        !           212:        }
        !           213:        break;
        !           214:     case SEND:
        !           215:        exch_state.opcode = EXCH_EXCH_TURNAROUND;
        !           216:        if (send_state() == -1) {
        !           217:            return -1;
        !           218:        }
        !           219:        break;
        !           220:     }
        !           221:     conversation = RECEIVE;
        !           222:     return 0;
        !           223: }
        !           224: 
        !           225: static int
        !           226: enter_send()
        !           227: {
        !           228:     switch (conversation) {
        !           229:     case CONTENTION:
        !           230:        exch_state.opcode = EXCH_EXCH_RTS;
        !           231:        if (send_state() == -1) {
        !           232:            return -1;
        !           233:        }
        !           234:         /* fall through */
        !           235:     case RECEIVE:
        !           236:        if (receive_state() == -1) {
        !           237:            return -1;
        !           238:        }
        !           239:        if (exch_state.opcode != EXCH_EXCH_TURNAROUND) {
        !           240:            WHO_ARE_WE();
        !           241:            fprintf(stderr, "Conversation error - both sides in SEND state.\n");
        !           242:            return -1;
        !           243:        }
        !           244:     }
        !           245:     conversation = SEND;
        !           246:     return 0;
        !           247: }
        !           248: 
        !           249: int
        !           250: api_exch_nextcommand()
        !           251: {
        !           252:     if (conversation != RECEIVE) {
        !           253:        if (enter_receive() == -1) {
        !           254:            return -1;
        !           255:        }
        !           256:     }
        !           257:     if (receive_state() == -1) {
        !           258:        return -1;
        !           259:     }
        !           260:     if (exch_state.opcode != EXCH_EXCH_COMMAND) {
        !           261:        WHO_ARE_WE();
        !           262:        fprintf(stderr, "Expected a %s exchange, received a %s exchange.\n",
        !           263:            exch_to_ascii(EXCH_EXCH_COMMAND), exch_to_ascii(exch_state.opcode));
        !           264:        return -1;
        !           265:     }
        !           266:     return exch_state.command_or_type;
        !           267: }
        !           268: 
        !           269: 
        !           270: int
        !           271: api_exch_incommand(command)
        !           272: int command;
        !           273: {
        !           274:     int i;
        !           275: 
        !           276:     if ((i = api_exch_nextcommand()) == -1) {
        !           277:        return -1;
        !           278:     }
        !           279:     if (i != command) {
        !           280:        WHO_ARE_WE();
        !           281:        fprintf(stderr, "Expected API command 0x%x, got API command 0x%x.\n",
        !           282:                                command, i);
        !           283:        return -1;
        !           284:     }
        !           285:     return 0;
        !           286: }
        !           287: 
        !           288: 
        !           289: int
        !           290: api_exch_outcommand(command)
        !           291: int command;
        !           292: {
        !           293:     if (conversation != SEND) {
        !           294:        if (enter_send() == -1) {
        !           295:            return -1;
        !           296:        }
        !           297:     }
        !           298:     exch_state.command_or_type = command;
        !           299:     exch_state.opcode = EXCH_EXCH_COMMAND;
        !           300:     if (send_state() == -1) {
        !           301:        return -1;
        !           302:     } else {
        !           303:        return 0;
        !           304:     }
        !           305: }
        !           306: 
        !           307: 
        !           308: int
        !           309: api_exch_outtype(type, length, location)
        !           310: int
        !           311:     type,
        !           312:     length;
        !           313: char
        !           314:     *location;
        !           315: {
        !           316:     int netleng = length;
        !           317: 
        !           318:     if (conversation != SEND) {
        !           319:        if (enter_send() == -1) {
        !           320:            return -1;
        !           321:        }
        !           322:     }
        !           323:     exch_state.opcode = EXCH_EXCH_TYPE;
        !           324:     exch_state.command_or_type = type;
        !           325:     exch_state.length = netleng;
        !           326:     if (send_state() == -1) {
        !           327:        return -1;
        !           328:     }
        !           329:     if (length) {
        !           330:        if (OBUFROOM() > length) {
        !           331:            OBUFADDBYTES(location, length);
        !           332:        } else {
        !           333:            if (outflush() == -1) {
        !           334:                return -1;
        !           335:            }
        !           336:            if (write(sock, location, length) != length) {
        !           337:                WHO_ARE_WE();
        !           338:                perror("write");
        !           339:                return -1;
        !           340:            }
        !           341:        }
        !           342:     }
        !           343:     return 0;
        !           344: }
        !           345: 
        !           346: 
        !           347: int
        !           348: api_exch_intype(type, length, location)
        !           349: int
        !           350:     type,
        !           351:     length;
        !           352: char
        !           353:     *location;
        !           354: {
        !           355:     int netleng = length;
        !           356: 
        !           357:     if (conversation != RECEIVE) {
        !           358:        if (enter_receive() == -1) {
        !           359:            return -1;
        !           360:        }
        !           361:     }
        !           362:     if (receive_state() == -1) {
        !           363:        return -1;
        !           364:     }
        !           365:     if (exch_state.opcode != EXCH_EXCH_TYPE) {
        !           366:        WHO_ARE_WE();
        !           367:        fprintf(stderr,
        !           368:            "Expected to receive a %s exchange, received a %s exchange.\n",
        !           369:            exch_to_ascii(EXCH_EXCH_TYPE), exch_to_ascii(exch_state.opcode));
        !           370:        return -1;
        !           371:     }
        !           372:     if (exch_state.command_or_type != type) {
        !           373:        WHO_ARE_WE();
        !           374:        fprintf(stderr, "Expected type 0x%x, got type 0x%x.\n",
        !           375:            type, exch_state.command_or_type);
        !           376:        return -1;
        !           377:     }
        !           378:     if (exch_state.length != netleng) {
        !           379:        fprintf(stderr, "Type 0x%x - expected length %d, received length %u.\n",
        !           380:                type, length, exch_state.length);
        !           381:        return -1;
        !           382:     }
        !           383:     if (iget(location, length) == -1) {
        !           384:        return -1;
        !           385:     }
        !           386:     return 0;
        !           387: }
        !           388: 
        !           389: int
        !           390: api_exch_flush()
        !           391: {
        !           392:     return outflush();
        !           393: }
        !           394: 
        !           395: int
        !           396: api_exch_init(sock_number, ourname)
        !           397: int sock_number;
        !           398: char *ourname;
        !           399: {
        !           400:     extern char *strcpy();
        !           401: 
        !           402:     sock = sock_number;
        !           403:     (void) strcpy(whoarewe, ourname);          /* For error messages */
        !           404: 
        !           405:     my_sequence = your_sequence = 0;
        !           406: 
        !           407:     conversation = CONTENTION;         /* We don't know which direction */
        !           408: 
        !           409:     IBUFRESET();
        !           410:     OBUFRESET();
        !           411: 
        !           412:     return 0;
        !           413: }

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