Annotation of 43BSD/contrib/xns/xnslib/readwrite.c, revision 1.1

1.1     ! root        1: /*
        !             2:  * This file implements functions used by both client and servers in the
        !             3:  * XNS courier library
        !             4:  */
        !             5: 
        !             6: /*
        !             7:  $Log: readwrite.c,v $
        !             8:  * Revision 2.0  85/11/21  07:22:15  jqj
        !             9:  * 4.3BSD standard release
        !            10:  * 
        !            11:  * Revision 1.8  85/10/21  13:01:17  jqj
        !            12:  * Gould version.
        !            13:  * 
        !            14:  * Revision 1.7  85/10/17  07:22:53  jqj
        !            15:  * Fix to previous edit.
        !            16:  * 
        !            17:  * Revision 1.6  85/10/17  07:07:02  jqj
        !            18:  * ReadMessage had a typo which Gould compiler caught:  bug in case of
        !            19:  * message with Courier header split across several SPP packets.
        !            20:  * 
        !            21:  * Revision 1.5  85/09/27  16:01:23  jqj
        !            22:  * added error checking to read in ReadMessage to bomb on closed connections.
        !            23:  * 
        !            24:  * Revision 1.4  85/03/11  16:37:24  jqj
        !            25:  * Public alpha-test version, released 11 March 1985
        !            26:  * 
        !            27:  * Revision 1.3  85/02/22  09:27:40  bill
        !            28:  * Almost working version.  Am about to change 
        !            29:  * ReadMessage to match what really shows up from the Xerox stuff.
        !            30:  * 
        !            31:  * Revision 1.2  85/01/27  07:37:39  jqj
        !            32:  * finished but undebugged version
        !            33:  * 
        !            34:  */
        !            35: 
        !            36: #ifndef lint
        !            37: static char rcsid[] = "$Header: readwrite.c,v 2.0 85/11/21 07:22:15 jqj Exp $";
        !            38: #endif
        !            39: 
        !            40: #include <stdio.h>
        !            41: #include <sys/types.h>         /* for ns.h and socket.h */
        !            42: #include <sys/socket.h>
        !            43: #include <sys/time.h>
        !            44: #include <sys/uio.h>           /* for scatter/gather io */
        !            45: #include <netns/ns.h>          /* for XNS addresses and courierconnection.h */
        !            46: #include <netns/idp.h>
        !            47: #include <netns/sp.h>          /* for spphdr */
        !            48: #include <errno.h>             /* for EPROTOTYPE */
        !            49: #include "courier.h"
        !            50: #include "realcourierconnection.h"
        !            51: 
        !            52: #define MAKEVEC(idx, addr, len) our_iovec[idx].iov_base = (caddr_t)addr;\
        !            53:                                our_iovec[idx].iov_len = len;
        !            54: 
        !            55: 
        !            56: CourierWrite(f, hdrlen, hdrbuf, nwords, arguments)
        !            57: /* write a 2-block message possibly consisting of several packets */
        !            58:        register CourierConnection *f;
        !            59:        int hdrlen;                     /* length of hdrbuf, in words */
        !            60:        Unspecified *hdrbuf;
        !            61:        register Cardinal nwords;       /* length of arguments, in words */
        !            62:        register Unspecified *arguments;
        !            63: {
        !            64:        struct iovec our_iovec[3];
        !            65: 
        !            66:        if (f->state == closed) {
        !            67:                f->abortseen = FALSE;
        !            68:                if ((f->fd = openSPPConnection(&(f->host))) >= 0) {
        !            69:                        f->state = wantversion;
        !            70:                }
        !            71:                else {
        !            72:                        fprintf(stderr,"(Courier) Can't reopen SPP connection\n");
        !            73:                        exit(1);
        !            74:                        /* NOTREACHED */
        !            75:                }
        !            76:        }
        !            77:        MAKEVEC(0, &(f->sphdrOpts), sizeof(f->sphdrOpts));
        !            78:        MAKEVEC(1, hdrbuf, (hdrlen*sizeof(Unspecified)) );
        !            79:        if (nwords <= MAXWORDS-hdrlen) {
        !            80:                /* SetSPPoptions(f->fd, SPPSST_RPC, 1, 0);
        !            81:                         datastream=0, EOM=TRUE, Attn=FALSE */
        !            82:                f->sphdrOpts.sp_dt = SPPSST_RPC;
        !            83:                f->sphdrOpts.sp_cc |= SP_EM;
        !            84:                MAKEVEC(2, arguments, nwords*sizeof(Unspecified));
        !            85:                if (writev(f->fd, our_iovec, 3) < 0) {
        !            86:                        perror("(Courier) writev");
        !            87:                        exit(1);
        !            88:                }
        !            89:        
        !            90:        }
        !            91:        else {
        !            92:                MAKEVEC(2, arguments, (MAXWORDS-hdrlen)*sizeof(Unspecified));
        !            93:                /* SetSPPoptions(f->fd, SPPSST_RPC, 0, 0);
        !            94:                        /* datastream=0, EOM=FALSE, Attn=FALSE */
        !            95:                f->sphdrOpts.sp_dt = SPPSST_RPC;
        !            96:                f->sphdrOpts.sp_cc &=  ~SP_EM;
        !            97:                nwords -= MAXWORDS-hdrlen;  arguments += MAXWORDS-hdrlen;
        !            98:                if (writev(f->fd, our_iovec, 3) < 0) {
        !            99:                        perror("(Courier) writev");
        !           100:                        exit(1);
        !           101:                }
        !           102:                MAKEVEC(1, (char *)arguments, MAXWORDS*sizeof(Unspecified));
        !           103:                while (nwords > MAXWORDS) {
        !           104:                        writev(f->fd, our_iovec, 2);
        !           105:                        nwords -= MAXWORDS;  arguments += MAXWORDS;
        !           106:                        our_iovec[1].iov_base = (char *)arguments;
        !           107:                }
        !           108:                f->sphdrOpts.sp_cc |=  SP_EM;
        !           109:                /* SetSPPoptions(f->fd, SPPSST_RPC, 1, 0);
        !           110:                        /* datastream=0, EOM=TRUE, Attn=FALSE */
        !           111:                our_iovec[1].iov_len = nwords*sizeof(Unspecified);
        !           112:                writev(f->fd, our_iovec, 2);
        !           113:        }
        !           114: 
        !           115: }
        !           116: 
        !           117: 
        !           118: 
        !           119: Unspecified *
        !           120: ReadMessage(f, firstbuf, firstlength)
        !           121:        register CourierConnection *f;  /* socket descriptor */
        !           122:        Unspecified *firstbuf;
        !           123:        Cardinal firstlength;
        !           124: /* Read a complete Courier message from SPP socket f->fd, skipping packets
        !           125:  * with the wrong datastream type.
        !           126:  * If firstbuf is specified with a non-zero length (in Unspecifieds), then it 
        !           127:  * is filled before the malloced packet.
        !           128:  * Return a pointer to beginning of a malloced packet (caller is responsible
        !           129:  * for freeing it), and a length in *retlength
        !           130:  * Returns NULL if connection closes prematurely.
        !           131:  */
        !           132: {
        !           133:        char *buf;                      /* ptr to message buffer */
        !           134:        Cardinal length,                /* current message length, bytes */
        !           135:                bufsize,                /* current buffer size, bytes */
        !           136:                nextincrement;          /* amt of space to try for next */
        !           137:        register int count;             /* data bytes read by current readv() */
        !           138:        struct iovec our_iovec[3];
        !           139:        struct {
        !           140:                struct sphdr hdr;
        !           141:                Cardinal version[2];
        !           142:        } hdrbuf;
        !           143:        Cardinal versionl,              /* version numbers received */
        !           144:                versionh;
        !           145:        int verbyteswanted;
        !           146:        extern char *malloc(), *realloc();
        !           147:        extern free();
        !           148:        int cc;
        !           149: 
        !           150:        /* spp & idp header */
        !           151:        MAKEVEC(0, &hdrbuf.hdr, sizeof(struct sphdr));
        !           152:        /* conn id, etc... */
        !           153:        if (firstbuf == NULL)
        !           154:                firstlength = 0;
        !           155:        else
        !           156:                firstlength *= sizeof(Unspecified);     /* length in bytes */
        !           157:        MAKEVEC(1, firstbuf, firstlength);
        !           158:        /* data */
        !           159:        buf = malloc(SPPMAXDATA);
        !           160:        MAKEVEC(2, buf, SPPMAXDATA);
        !           161: 
        !           162:        bufsize = SPPMAXDATA;
        !           163:        /*
        !           164:         * flush Courier version number if necessary
        !           165:         */
        !           166:        if (f->state != wantversion) {
        !           167:                /* we don't have to look for a version number this time! */
        !           168:                count = readv(f->fd, our_iovec, 3) - sizeof(struct sphdr);
        !           169:                if (count < 0 || hdrbuf.hdr.sp_dt == SPPSST_END) {
        !           170:                        if (count >= 0) (void) sppclosereply(f->fd);
        !           171:                        f->state = closed;
        !           172:                        free(buf);
        !           173:                        return(NULL);
        !           174:                }
        !           175:        } else {
        !           176:                /* stick version range in with header */
        !           177:                verbyteswanted = 2*sizeof(Cardinal);
        !           178:                our_iovec[0].iov_len += verbyteswanted;
        !           179:                while (verbyteswanted > 0) {
        !           180:                        count = readv(f->fd, our_iovec, 3) 
        !           181:                                        - sizeof(struct sphdr);
        !           182:                        if (count < 0 || hdrbuf.hdr.sp_dt == SPPSST_END) {
        !           183:                                if (count >= 0) (void) sppclosereply(f->fd);
        !           184:                                f->state = closed;
        !           185:                                free(buf);
        !           186:                                return(NULL);
        !           187:                        }
        !           188:                        /* we don't bother to check for matching */
        !           189:                        /* Courier version */
        !           190:                        if (count >= verbyteswanted) {
        !           191:                                count -= verbyteswanted;
        !           192:                                our_iovec[0].iov_len -= verbyteswanted;
        !           193:                                verbyteswanted = 0;
        !           194:                        }
        !           195:                        else {
        !           196:                                verbyteswanted -= count;
        !           197:                                our_iovec[0].iov_len -= count;
        !           198:                                count = 0;
        !           199:                        }
        !           200:                }
        !           201:                f->state = inprogress;
        !           202:                while (count == 0) {
        !           203:                        /* read either RPC reply or BDT garbage */
        !           204:                        count = readv(f->fd, our_iovec, 3)
        !           205:                                        - sizeof(struct sphdr);
        !           206:                        if (count < 0 || hdrbuf.hdr.sp_dt == SPPSST_END) {
        !           207:                                if (count >= 0) (void) sppclosereply(f->fd);
        !           208:                                f->state = closed;
        !           209:                                free(buf);
        !           210:                                return(NULL);
        !           211:                        }
        !           212:                }
        !           213:                /* {version-packet, null-0-packet, bdt-packet, reply-packet}, 
        !           214:                 * is handled, but I don't think it's legal */
        !           215:        }
        !           216:        /*
        !           217:         * we've flushed any version number that might be present,
        !           218:         * and have read the first packet -- which may be garbage.
        !           219:         * Throw away any further garbage (e.g. BDT data) too.  
        !           220:         */
        !           221:        while (hdrbuf.hdr.sp_dt != SPPSST_RPC) {
        !           222:                count = readv(f->fd, our_iovec, 3) - sizeof(struct sphdr);
        !           223:                if (count < 0 || hdrbuf.hdr.sp_dt == SPPSST_END) {
        !           224:                        if (count >= 0) (void) sppclosereply(f->fd);
        !           225:                        f->state = closed;
        !           226:                        free(buf);
        !           227:                        return(NULL);
        !           228:                }
        !           229:        }
        !           230:        /*
        !           231:         * Now we have a real RPC data packet, which we hope is the reply
        !           232:         */
        !           233:        length = count;
        !           234:        nextincrement = SPPMAXDATA;
        !           235:        while ( ! (hdrbuf.hdr.sp_cc & SP_EM)) {
        !           236:                /* Not to end of message yet, so read another packet */
        !           237:                if (length+nextincrement-firstlength > bufsize) {
        !           238:                        /* not enough space for next packet.  Make room. */
        !           239:                        bufsize = length+nextincrement-firstlength;
        !           240:                        buf = realloc(buf, (unsigned) bufsize);
        !           241:                        /* do order(log(messagelength)) reallocs */
        !           242:                        nextincrement += nextincrement;
        !           243:                }
        !           244:                if (length >= firstlength) {
        !           245:                        MAKEVEC(1,NULL,0);
        !           246:                        MAKEVEC(2,buf+length-firstlength,bufsize+firstlength-length);
        !           247:                }
        !           248:                else {
        !           249:                        firstbuf += length/sizeof(Unspecified);
        !           250:                        firstlength -= length;
        !           251:                        MAKEVEC(1, firstbuf, firstlength);
        !           252:                }
        !           253:                count = readv(f->fd, our_iovec, 3) - sizeof(struct sphdr);
        !           254:                if (count < 0 || hdrbuf.hdr.sp_dt == SPPSST_END) {
        !           255:                        if (count >= 0) (void) sppclosereply(f->fd);
        !           256:                        f->state = closed;
        !           257:                        free(buf);
        !           258:                        return(NULL);
        !           259:                }
        !           260:                if (hdrbuf.hdr.sp_dt != SPPSST_RPC) {
        !           261:                        fprintf(stderr,"(Courier) Stream type changed from %d to %d during message\n",
        !           262:                                SPPSST_RPC, hdrbuf.hdr.sp_dt);
        !           263:                        exit(1);
        !           264:                        /* NOTREACHED */
        !           265:                }
        !           266:                length += count;
        !           267:        }
        !           268:        return((Unspecified*) buf);
        !           269: }
        !           270: 
        !           271: 
        !           272: 
        !           273: CheckEND(f)
        !           274: /* look ahead on courier connection, checking for an END packet.
        !           275:  * If seen, set state to closed.
        !           276:  */
        !           277:        CourierConnection *f;
        !           278: {
        !           279:        struct {
        !           280:                struct sphdr hdr;
        !           281:                char data[SPPMAXDATA];
        !           282:        } packbuf;
        !           283:        int count;
        !           284:        int fdmask;
        !           285:        static struct timeval timeout = {0,0};
        !           286: 
        !           287:        fdmask = 1<<(f->fd);
        !           288:        while (select(f->fd+1,&fdmask,(int*)NULL,(int*)NULL,&timeout) > 0
        !           289:            && (count = recv(f->fd,(char*)&packbuf, sizeof(packbuf),
        !           290:                                MSG_PEEK)) > 0) {
        !           291:                if (packbuf.hdr.sp_dt == SPPSST_END) {
        !           292:                        read(f->fd, (char*)&packbuf, sizeof(packbuf));
        !           293:                        (void) sppclosereply(f->fd);
        !           294:                        f->state = closed;
        !           295:                        return(TRUE);
        !           296:                }
        !           297:                else if (count == sizeof(struct sphdr))
        !           298:                        read(f->fd, (char*)&packbuf, sizeof(packbuf));
        !           299:                else return(FALSE);
        !           300:        }
        !           301:        return(FALSE);
        !           302: }
        !           303: 
        !           304: 
        !           305: CourierClose(conn)
        !           306:        CourierConnection * conn;
        !           307: {
        !           308:        (void) sppclose(conn->fd);
        !           309:        free((char*) conn);
        !           310: }
        !           311: 
        !           312: 
        !           313: openSPPConnection(dst)
        !           314:        struct sockaddr_ns *dst;
        !           315: {
        !           316:        int s;
        !           317:        extern int errno;
        !           318: 
        !           319:        if ((s = socket(dst->sns_family, SOCK_SEQPACKET, 0)) < 0) {
        !           320:                perror("(Courier) socket");
        !           321:                exit(1);
        !           322:                /*NOTREACHED*/
        !           323:        }
        !           324:        if (connect(s, (struct sockaddr*)dst, sizeof(struct sockaddr_ns)) < 0) {
        !           325:                perror("(Courier) connect");
        !           326:                exit(1);
        !           327:                /*NOTREACHED*/
        !           328:        }
        !           329:        return(s);
        !           330: }

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