Annotation of 43BSDTahoe/new/xns/xnslib/readwrite.c, revision 1.1.1.1

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 2.5  87/04/12  14:01:18  jqj
                      9:  * typo in previous
                     10:  * 
                     11:  * Revision 2.3  87/04/12  13:52:27  jqj
                     12:  * don't print silly message if remote system is down -- let higher level
                     13:  * software say so.
                     14:  * 
                     15:  * Revision 2.2  86/11/07  15:58:05  jqj
                     16:  * Fixes for very long messages from [email protected].
                     17:  * 
                     18:  * Revision 2.1  86/09/07  07:31:59  jqj
                     19:  * OpenSPPconnection should return -1 on failure.
                     20:  * 
                     21:  * Revision 2.0  85/11/21  07:22:15  jqj
                     22:  * 4.3BSD standard release
                     23:  * 
                     24:  * Revision 1.8  85/10/21  13:01:17  jqj
                     25:  * Gould version.
                     26:  * 
                     27:  * Revision 1.7  85/10/17  07:22:53  jqj
                     28:  * Fix to previous edit.
                     29:  * 
                     30:  * Revision 1.6  85/10/17  07:07:02  jqj
                     31:  * ReadMessage had a typo which Gould compiler caught:  bug in case of
                     32:  * message with Courier header split across several SPP packets.
                     33:  * 
                     34:  * Revision 1.5  85/09/27  16:01:23  jqj
                     35:  * added error checking to read in ReadMessage to bomb on closed connections.
                     36:  * 
                     37:  * Revision 1.4  85/03/11  16:37:24  jqj
                     38:  * Public alpha-test version, released 11 March 1985
                     39:  * 
                     40:  * Revision 1.3  85/02/22  09:27:40  bill
                     41:  * Almost working version.  Am about to change 
                     42:  * ReadMessage to match what really shows up from the Xerox stuff.
                     43:  * 
                     44:  * Revision 1.2  85/01/27  07:37:39  jqj
                     45:  * finished but undebugged version
                     46:  * 
                     47:  */
                     48: 
                     49: #ifndef lint
                     50: static char rcsid[] = "$Header: readwrite.c,v 2.5 87/04/12 14:01:18 jqj Exp $";
                     51: #endif
                     52: 
                     53: #include <stdio.h>
                     54: #include <sys/types.h>         /* for ns.h and socket.h */
                     55: #include <sys/socket.h>
                     56: #include <sys/time.h>
                     57: #include <sys/uio.h>           /* for scatter/gather io */
                     58: #include <netns/ns.h>          /* for XNS addresses and courierconnection.h */
                     59: #include <netns/idp.h>
                     60: #include <netns/sp.h>          /* for spphdr */
                     61: #include <errno.h>             /* for EPROTOTYPE */
                     62: #include "courier.h"
                     63: #include "realcourierconnection.h"
                     64: 
                     65: #define MAKEVEC(idx, addr, len) our_iovec[idx].iov_base = (caddr_t)addr;\
                     66:                                our_iovec[idx].iov_len = len;
                     67: 
                     68: 
                     69: CourierWrite(f, hdrlen, hdrbuf, nwords, arguments)
                     70: /* write a 2-block message possibly consisting of several packets */
                     71:        register CourierConnection *f;
                     72:        int hdrlen;                     /* length of hdrbuf, in words */
                     73:        Unspecified *hdrbuf;
                     74:        register Cardinal nwords;       /* length of arguments, in words */
                     75:        register Unspecified *arguments;
                     76: {
                     77:        struct iovec our_iovec[3];
                     78: 
                     79:        if (f->state == closed) {
                     80:                f->abortseen = FALSE;
                     81:                if ((f->fd = openSPPConnection(&(f->host))) >= 0) {
                     82:                        f->state = wantversion;
                     83:                }
                     84:                else {
                     85:                        fprintf(stderr,"(Courier) Can't reopen SPP connection\n");
                     86:                        exit(1);
                     87:                        /* NOTREACHED */
                     88:                }
                     89:        }
                     90:        MAKEVEC(0, &(f->sphdrOpts), sizeof(f->sphdrOpts));
                     91:        MAKEVEC(1, hdrbuf, (hdrlen*sizeof(Unspecified)) );
                     92:        if (nwords <= MAXWORDS-hdrlen) {
                     93:                /* SetSPPoptions(f->fd, SPPSST_RPC, 1, 0);
                     94:                         datastream=0, EOM=TRUE, Attn=FALSE */
                     95:                f->sphdrOpts.sp_dt = SPPSST_RPC;
                     96:                f->sphdrOpts.sp_cc |= SP_EM;
                     97:                MAKEVEC(2, arguments, nwords*sizeof(Unspecified));
                     98:                if (writev(f->fd, our_iovec, 3) < 0) {
                     99:                        perror("(Courier) writev");
                    100:                        exit(1);
                    101:                }
                    102:        
                    103:        }
                    104:        else {
                    105:                MAKEVEC(2, arguments, (MAXWORDS-hdrlen)*sizeof(Unspecified));
                    106:                /* SetSPPoptions(f->fd, SPPSST_RPC, 0, 0);
                    107:                        /* datastream=0, EOM=FALSE, Attn=FALSE */
                    108:                f->sphdrOpts.sp_dt = SPPSST_RPC;
                    109:                f->sphdrOpts.sp_cc &=  ~SP_EM;
                    110:                nwords -= MAXWORDS-hdrlen;  arguments += MAXWORDS-hdrlen;
                    111:                if (writev(f->fd, our_iovec, 3) < 0) {
                    112:                        perror("(Courier) writev");
                    113:                        exit(1);
                    114:                }
                    115:                MAKEVEC(1, (char *)arguments, MAXWORDS*sizeof(Unspecified));
                    116:                while (nwords > MAXWORDS) {
                    117:                        writev(f->fd, our_iovec, 2);
                    118:                        nwords -= MAXWORDS;  arguments += MAXWORDS;
                    119:                        our_iovec[1].iov_base = (char *)arguments;
                    120:                }
                    121:                f->sphdrOpts.sp_cc |=  SP_EM;
                    122:                /* SetSPPoptions(f->fd, SPPSST_RPC, 1, 0);
                    123:                        /* datastream=0, EOM=TRUE, Attn=FALSE */
                    124:                our_iovec[1].iov_len = nwords*sizeof(Unspecified);
                    125:                writev(f->fd, our_iovec, 2);
                    126:        }
                    127: 
                    128: }
                    129: 
                    130: 
                    131: 
                    132: Unspecified *
                    133: ReadMessage(f, firstbuf, firstlength)
                    134:        register CourierConnection *f;  /* socket descriptor */
                    135:        Unspecified *firstbuf;
                    136:        Cardinal firstlength;
                    137: /* Read a complete Courier message from SPP socket f->fd, skipping packets
                    138:  * with the wrong datastream type.
                    139:  * If firstbuf is specified with a non-zero length (in Unspecifieds), then it 
                    140:  * is filled before the malloced packet.
                    141:  * Return a pointer to beginning of a malloced packet (caller is responsible
                    142:  * for freeing it), and a length in *retlength
                    143:  * Returns NULL if connection closes prematurely.
                    144:  */
                    145: {
                    146:        char *buf;                      /* ptr to message buffer */
                    147:        LongCardinal length,            /* current message length, bytes */
                    148:                bufsize,                /* current buffer size, bytes */
                    149:                nextincrement;          /* amt of space to try for next */
                    150:        register int count;             /* data bytes read by current readv() */
                    151:        struct iovec our_iovec[3];
                    152:        struct {
                    153:                struct sphdr hdr;
                    154:                Cardinal version[2];
                    155:        } hdrbuf;
                    156:        Cardinal versionl,              /* version numbers received */
                    157:                versionh;
                    158:        int verbyteswanted;
                    159:        extern char *malloc(), *realloc();
                    160:        extern free();
                    161:        int cc;
                    162: 
                    163:        /* spp & idp header */
                    164:        MAKEVEC(0, &hdrbuf.hdr, sizeof(struct sphdr));
                    165:        /* conn id, etc... */
                    166:        if (firstbuf == NULL)
                    167:                firstlength = 0;
                    168:        else
                    169:                firstlength *= sizeof(Unspecified);     /* length in bytes */
                    170:        MAKEVEC(1, firstbuf, firstlength);
                    171:        /* data */
                    172:        buf = malloc(SPPMAXDATA);
                    173:        MAKEVEC(2, buf, SPPMAXDATA);
                    174: 
                    175:        bufsize = SPPMAXDATA;
                    176:        /*
                    177:         * flush Courier version number if necessary
                    178:         */
                    179:        if (f->state != wantversion) {
                    180:                /* we don't have to look for a version number this time! */
                    181:                count = readv(f->fd, our_iovec, 3) - 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:        } else {
                    189:                /* stick version range in with header */
                    190:                verbyteswanted = 2*sizeof(Cardinal);
                    191:                our_iovec[0].iov_len += verbyteswanted;
                    192:                while (verbyteswanted > 0) {
                    193:                        count = readv(f->fd, our_iovec, 3) 
                    194:                                        - sizeof(struct sphdr);
                    195:                        if (count < 0 || hdrbuf.hdr.sp_dt == SPPSST_END) {
                    196:                                if (count >= 0) (void) sppclosereply(f->fd);
                    197:                                f->state = closed;
                    198:                                free(buf);
                    199:                                return(NULL);
                    200:                        }
                    201:                        /* we don't bother to check for matching */
                    202:                        /* Courier version */
                    203:                        if (count >= verbyteswanted) {
                    204:                                count -= verbyteswanted;
                    205:                                our_iovec[0].iov_len -= verbyteswanted;
                    206:                                verbyteswanted = 0;
                    207:                        }
                    208:                        else {
                    209:                                verbyteswanted -= count;
                    210:                                our_iovec[0].iov_len -= count;
                    211:                                count = 0;
                    212:                        }
                    213:                }
                    214:                f->state = inprogress;
                    215:                while (count == 0) {
                    216:                        /* read either RPC reply or BDT garbage */
                    217:                        count = readv(f->fd, our_iovec, 3)
                    218:                                        - sizeof(struct sphdr);
                    219:                        if (count < 0 || hdrbuf.hdr.sp_dt == SPPSST_END) {
                    220:                                if (count >= 0) (void) sppclosereply(f->fd);
                    221:                                f->state = closed;
                    222:                                free(buf);
                    223:                                return(NULL);
                    224:                        }
                    225:                }
                    226:                /* {version-packet, null-0-packet, bdt-packet, reply-packet}, 
                    227:                 * is handled, but I don't think it's legal */
                    228:        }
                    229:        /*
                    230:         * we've flushed any version number that might be present,
                    231:         * and have read the first packet -- which may be garbage.
                    232:         * Throw away any further garbage (e.g. BDT data) too.  
                    233:         */
                    234:        while (hdrbuf.hdr.sp_dt != SPPSST_RPC) {
                    235:                count = readv(f->fd, our_iovec, 3) - sizeof(struct sphdr);
                    236:                if (count < 0 || hdrbuf.hdr.sp_dt == SPPSST_END) {
                    237:                        if (count >= 0) (void) sppclosereply(f->fd);
                    238:                        f->state = closed;
                    239:                        free(buf);
                    240:                        return(NULL);
                    241:                }
                    242:        }
                    243:        /*
                    244:         * Now we have a real RPC data packet, which we hope is the reply
                    245:         */
                    246:        length = count;
                    247:        nextincrement = SPPMAXDATA;
                    248:        while ( ! (hdrbuf.hdr.sp_cc & SP_EM)) {
                    249:                /* Not to end of message yet, so read another packet */
                    250:                if (length+SPPMAXDATA-firstlength > bufsize) {
                    251:                        /* not enough space for next packet.  Make room. */
                    252:                        bufsize += nextincrement;
                    253:                        buf = realloc(buf, (unsigned) bufsize);
                    254:                        /* do order(log(messagelength)) reallocs */
                    255:                        nextincrement += nextincrement;
                    256:                }
                    257:                if (length >= firstlength) {
                    258:                        MAKEVEC(1,NULL,0);
                    259:                        MAKEVEC(2,buf+length-firstlength,bufsize+firstlength-length);
                    260:                }
                    261:                else {
                    262:                        firstbuf += length/sizeof(Unspecified);
                    263:                        firstlength -= length;
                    264:                        MAKEVEC(1, firstbuf, firstlength);
                    265:                }
                    266:                count = readv(f->fd, our_iovec, 3) - sizeof(struct sphdr);
                    267:                if (count < 0 || hdrbuf.hdr.sp_dt == SPPSST_END) {
                    268:                        if (count >= 0) (void) sppclosereply(f->fd);
                    269:                        f->state = closed;
                    270:                        free(buf);
                    271:                        return(NULL);
                    272:                }
                    273:                if (hdrbuf.hdr.sp_dt != SPPSST_RPC) {
                    274:                        fprintf(stderr,"(Courier) Stream type changed from %d to %d during message\n",
                    275:                                SPPSST_RPC, hdrbuf.hdr.sp_dt);
                    276:                        exit(1);
                    277:                        /* NOTREACHED */
                    278:                }
                    279:                length += count;
                    280:        }
                    281:        return((Unspecified*) buf);
                    282: }
                    283: 
                    284: 
                    285: 
                    286: CheckEND(f)
                    287: /* look ahead on courier connection, checking for an END packet.
                    288:  * If seen, set state to closed.
                    289:  */
                    290:        CourierConnection *f;
                    291: {
                    292:        struct {
                    293:                struct sphdr hdr;
                    294:                char data[SPPMAXDATA];
                    295:        } packbuf;
                    296:        int count;
                    297:        int fdmask;
                    298:        static struct timeval timeout = {0,0};
                    299: 
                    300:        fdmask = 1<<(f->fd);
                    301:        while (select(f->fd+1,&fdmask,(int*)NULL,(int*)NULL,&timeout) > 0
                    302:            && (count = recv(f->fd,(char*)&packbuf, sizeof(packbuf),
                    303:                                MSG_PEEK)) > 0) {
                    304:                if (packbuf.hdr.sp_dt == SPPSST_END) {
                    305:                        read(f->fd, (char*)&packbuf, sizeof(packbuf));
                    306:                        (void) sppclosereply(f->fd);
                    307:                        f->state = closed;
                    308:                        return(TRUE);
                    309:                }
                    310:                else if (count == sizeof(struct sphdr))
                    311:                        read(f->fd, (char*)&packbuf, sizeof(packbuf));
                    312:                else return(FALSE);
                    313:        }
                    314:        return(FALSE);
                    315: }
                    316: 
                    317: 
                    318: CourierClose(conn)
                    319:        CourierConnection * conn;
                    320: {
                    321:        (void) sppclose(conn->fd);
                    322:        free((char*) conn);
                    323: }
                    324: 
                    325: 
                    326: /* returns either a socket or -1 on error */
                    327: int
                    328: openSPPConnection(dst)
                    329:        struct sockaddr_ns *dst;
                    330: {
                    331:        int s;
                    332:        extern int errno;
                    333: 
                    334:        if ((s = socket(dst->sns_family, SOCK_SEQPACKET, 0)) < 0) {
                    335:                perror("(Courier) socket");
                    336:                return(-1);
                    337:                /*NOTREACHED*/
                    338:        }
                    339:        if (connect(s, (struct sockaddr*)dst, sizeof(struct sockaddr_ns)) < 0) {
                    340:                if ((errno != ETIMEDOUT) && (errno != ECONNREFUSED))
                    341:                        perror("(Courier) connect");
                    342:                return(-1);
                    343:                /*NOTREACHED*/
                    344:        }
                    345:        return(s);
                    346: }

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