BSD 4_3_Net_1 release

[unix-history] / lib / libc / net / res_mkquery.c

/*
* Copyright (c) 1985 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)res_mkquery.c       6.9 (Berkeley) 12/8/88";
#endif /* LIBC_SCCS and not lint */

#include <stdio.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>

/*
* Form all types of queries.
* Returns the size of the result or -1.
*/
res_mkquery(op, dname, class, type, data, datalen, newrr, buf, buflen)
       int op;                 /* opcode of query */
       char *dname;            /* domain name */
       int class, type;        /* class and type of query */
       char *data;             /* resource record data */
       int datalen;            /* length of data */
       struct rrec *newrr;     /* new rr for modify or append */
       char *buf;              /* buffer to put query */
       int buflen;             /* size of buffer */
{
       register HEADER *hp;
       register char *cp;
       register int n;
       char dnbuf[MAXDNAME];
       char *dnptrs[10], **dpp, **lastdnptr;
       extern char *index();

#ifdef DEBUG
       if (_res.options & RES_DEBUG)
               printf("res_mkquery(%d, %s, %d, %d)\n", op, dname, class, type);
#endif DEBUG
       /*
        * Initialize header fields.
        */
       bzero(buf, sizeof(HEADER));
       hp = (HEADER *) buf;
       hp->id = htons(++_res.id);
       hp->opcode = op;
       hp->pr = (_res.options & RES_PRIMARY) != 0;
       hp->rd = (_res.options & RES_RECURSE) != 0;
       hp->rcode = NOERROR;
       cp = buf + sizeof(HEADER);
       buflen -= sizeof(HEADER);
       dpp = dnptrs;
       *dpp++ = buf;
       *dpp++ = NULL;
       lastdnptr = dnptrs + sizeof(dnptrs)/sizeof(dnptrs[0]);
       /*
        * perform opcode specific processing
        */
       switch (op) {
       case QUERY:
               buflen -= QFIXEDSZ;
               if ((n = dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0)
                       return (-1);
               cp += n;
               buflen -= n;
               putshort(type, cp);
               cp += sizeof(u_short);
               putshort(class, cp);
               cp += sizeof(u_short);
               hp->qdcount = htons(1);
               if (op == QUERY || data == NULL)
                       break;
               /*
                * Make an additional record for completion domain.
                */
               buflen -= RRFIXEDSZ;
               if ((n = dn_comp(data, cp, buflen, dnptrs, lastdnptr)) < 0)
                       return (-1);
               cp += n;
               buflen -= n;
               putshort(T_NULL, cp);
               cp += sizeof(u_short);
               putshort(class, cp);
               cp += sizeof(u_short);
               putlong(0, cp);
               cp += sizeof(u_long);
               putshort(0, cp);
               cp += sizeof(u_short);
               hp->arcount = htons(1);
               break;

       case IQUERY:
               /*
                * Initialize answer section
                */
               if (buflen < 1 + RRFIXEDSZ + datalen)
                       return (-1);
               *cp++ = '\0';   /* no domain name */
               putshort(type, cp);
               cp += sizeof(u_short);
               putshort(class, cp);
               cp += sizeof(u_short);
               putlong(0, cp);
               cp += sizeof(u_long);
               putshort(datalen, cp);
               cp += sizeof(u_short);
               if (datalen) {
                       bcopy(data, cp, datalen);
                       cp += datalen;
               }
               hp->ancount = htons(1);
               break;

#ifdef ALLOW_UPDATES
       /*
        * For UPDATEM/UPDATEMA, do UPDATED/UPDATEDA followed by UPDATEA
        * (Record to be modified is followed by its replacement in msg.)
        */
       case UPDATEM:
       case UPDATEMA:

       case UPDATED:
               /*
                * The res code for UPDATED and UPDATEDA is the same; user
                * calls them differently: specifies data for UPDATED; server
                * ignores data if specified for UPDATEDA.
                */
       case UPDATEDA:
               buflen -= RRFIXEDSZ + datalen;
               if ((n = dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0)
                       return (-1);
               cp += n;
               putshort(type, cp);
               cp += sizeof(u_short);
               putshort(class, cp);
               cp += sizeof(u_short);
               putlong(0, cp);
               cp += sizeof(u_long);
               putshort(datalen, cp);
               cp += sizeof(u_short);
               if (datalen) {
                       bcopy(data, cp, datalen);
                       cp += datalen;
               }
               if ( (op == UPDATED) || (op == UPDATEDA) ) {
                       hp->ancount = htons(0);
                       break;
               }
               /* Else UPDATEM/UPDATEMA, so drop into code for UPDATEA */

       case UPDATEA:   /* Add new resource record */
               buflen -= RRFIXEDSZ + datalen;
               if ((n = dn_comp(dname, cp, buflen, dnptrs, lastdnptr)) < 0)
                       return (-1);
               cp += n;
               putshort(newrr->r_type, cp);
               cp += sizeof(u_short);
               putshort(newrr->r_class, cp);
               cp += sizeof(u_short);
               putlong(0, cp);
               cp += sizeof(u_long);
               putshort(newrr->r_size, cp);
               cp += sizeof(u_short);
               if (newrr->r_size) {
                       bcopy(newrr->r_data, cp, newrr->r_size);
                       cp += newrr->r_size;
               }
               hp->ancount = htons(0);
               break;

#endif ALLOW_UPDATES
       }
       return (cp - buf);
}