BSD 4_3_Net_1 release

[unix-history] / named / ns_sort.c

/*
* Copyright (c) 1986 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.
*/

#ifndef lint
static char sccsid[] = "@(#)ns_sort.c   4.5 (Berkeley) 1/14/89";
#endif /* not lint */

#include <stdio.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <netinet/in.h>
#include <syslog.h>
#include <arpa/nameser.h>
#include "ns.h"
#include "db.h"

extern  char *p_type(), *p_class();

extern  int     debug;
extern  FILE    *ddt;

struct netinfo* 
local(from)
       struct sockaddr_in *from;
{
       extern struct netinfo *nettab, netloop;
       struct netinfo *ntp;

       if (from->sin_addr.s_addr == netloop.my_addr.s_addr)
               return( &netloop);
       for (ntp = nettab; ntp != NULL; ntp = ntp->next) {
               if (ntp->net == (from->sin_addr.s_addr & ntp->mask))
                       return(ntp);
       }
       return(NULL);
}


sort_response(cp, ancount, lp, eom)
       register char *cp;
       register int ancount;
       struct netinfo *lp;
       u_char *eom;
{
       register struct netinfo *ntp;
       extern struct netinfo *nettab;

#ifdef DEBUG
       if (debug > 2)
           fprintf(ddt,"sort_response(%d)\n", ancount);
#endif DEBUG
       if (ancount > 1) {
               if (sort_rr(cp, ancount, lp, eom))
                       return;
               for (ntp = nettab; ntp != NULL; ntp = ntp->next) {
                       if ((ntp->net == lp->net) && (ntp->mask == lp->mask))
                               continue;
                       if (sort_rr(cp, ancount, ntp, eom))
                               break;
               }
       }
}

int
sort_rr(cp, count, ntp, eom)
       register u_char *cp;
       int count;
       register struct netinfo *ntp;
       u_char *eom;
{
       int type, class, dlen, n, c;
       struct in_addr inaddr;
       u_char *rr1;

#ifdef DEBUG
       if (debug > 2) {
           inaddr.s_addr = ntp->net;
           fprintf(ddt,"sort_rr( x%x, %d, %s)\n",cp, count,
               inet_ntoa(inaddr));
       }
#endif DEBUG
       rr1 = NULL;
       for (c = count; c > 0; --c) {
           n = dn_skipname(cp, eom);
           if (n < 0)
               return (1);             /* bogus, stop processing */
           cp += n;
           if (cp + QFIXEDSZ > eom)
               return (1);
           GETSHORT(type, cp);
           GETSHORT(class, cp);
           cp += sizeof(u_long);
           GETSHORT(dlen, cp);
           if (dlen > eom - cp)
               return (1);             /* bogus, stop processing */
           switch (type) {
           case T_A:
               switch (class) {
               case C_IN:
                       bcopy(cp, (char *)&inaddr, sizeof(inaddr));
                       if (rr1 == NULL)
                               rr1 = cp;
                       if ((ntp->mask & inaddr.s_addr) == ntp->net) {
#ifdef DEBUG
                           if (debug > 1) {
                               fprintf(ddt,"net %s best choice\n",
                                       inet_ntoa(inaddr));
                           }
#endif DEBUG
                           if (rr1 != cp) {
                               bcopy(rr1, cp, sizeof(inaddr));
                               bcopy((char *)&inaddr, rr1, sizeof(inaddr));
                           }
                           return(1);
                       }
                       break;
               }
               break;
           }
           cp += dlen;
       }
       return(0);
}