date and time created 83/12/05 16:13:05 by ralph

[unix-history] / usr / src / lib / libc / net / gethostnamadr.c

/*      gethostnamadr.c 4.1     83/12/05        */

#include <stdio.h>
#include <netdb.h>
#include <sys/file.h>
#include <ndbm.h>

#define MAXALIASES      35

static char HOSTDB[] = "/etc/hosts";
static DBM *db = (DBM *)NULL;
static datum curkey;
static struct hostent host;
static char *host_aliases[MAXALIASES];

static struct hostent *
fetchhost(key)
       datum key;
{
       register char *cp, **ap;
       register int naliases;

       curkey = key;
       if (curkey.dptr == 0)
               return ((struct hostent *)NULL);
       key = dbmfetch(db, curkey);
       if (key.dptr == 0)
               return ((struct hostent *)NULL);
       cp = key.dptr;
       host.h_name = cp;
       while (*cp++)
               ;
       naliases = *(int *)cp; cp += sizeof (int);
       for (ap = host_aliases; naliases > 0; naliases--) {
               *ap++ = cp;
               while (*cp++)
                       ;
       }
       *ap = (char *)NULL;
       host.h_aliases = host_aliases;
       host.h_addrtype = *(int *)cp; cp += sizeof (int);
       host.h_length = *(int *)cp; cp += sizeof (int);
       host.h_addr = cp;
       return (&host);
}

struct hostent *
gethostbyname(nam)
       char *nam;
{
       datum key;
       register struct hostent *hp;

       if ((db = ndbmopen(HOSTDB, O_RDONLY)) == (DBM *)0)
               return ((struct hostent *)NULL);
       key.dptr = nam;
       key.dsize = strlen(nam);
       hp = fetchhost(key);
       ndbmclose(db);
       return (hp);
}

struct hostent *
gethostbyaddr(addr, length)
       char *addr;
       int length;
{
       datum key;
       register struct hostent *hp;

       if ((db = ndbmopen(HOSTDB, O_RDONLY)) == (DBM *)0)
               return ((struct hostent *)NULL);
       key.dptr = addr;
       key.dsize = length;
       hp = fetchhost(key);
       ndbmclose(db);
       return (hp);
}