/*-
* Copyright (c) 1985, 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* -
* Portions Copyright (c) 1993 by Digital Equipment Corporation.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies, and that
* the name of Digital Equipment Corporation not be used in advertising or
* publicity pertaining to distribution of the document or software without
* specific, written prior permission.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
* -
* --Copyright--
*/
/* Portions Copyright (c) 1993 Carlos Leandro and Rui Salgueiro
* Dep. Matematica Universidade de Coimbra, Portugal, Europe
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93";
static char rcsid[] = "$Id$";
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <stdio.h>
#include <netdb.h>
#include <resolv.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <syslog.h>
#include "res_config.h"
extern int h_errno;
#define BYADDR 0
#define BYNAME 1
#define MAXALIASES 35
#if PACKETSZ > 1024
#define MAXPACKET PACKETSZ
#else
#define MAXPACKET 1024
#endif
typedef union {
HEADER hdr;
u_char buf[MAXPACKET];
} querybuf;
typedef union {
long al;
char ac;
} align;
static struct netent *
getnetanswer(answer, anslen, net_i)
querybuf *answer;
int anslen;
int net_i;
{
register HEADER *hp;
register u_char *cp;
register int n;
u_char *eom;
int type, class, buflen, ancount, qdcount, haveanswer, i, nchar;
char aux1[MAXHOSTNAMELEN], aux2[MAXHOSTNAMELEN], ans[MAXHOSTNAMELEN];
char *in, *st, *pauxt, *bp, **ap;
char *paux1 = &aux1[0], *paux2 = &aux2[0], flag = 0;
static struct netent net_entry;
static char *net_aliases[MAXALIASES], netbuf[PACKETSZ];
/*
* find first satisfactory answer
*
* answer --> +------------+ ( MESSAGE )
* | Header |
* +------------+
* | Question | the question for the name server
* +------------+
* | Answer | RRs answering the question
* +------------+
* | Authority | RRs pointing toward an authority
* | Additional | RRs holding additional information
* +------------+
*/
eom = answer->buf + anslen;
hp = &answer->hdr;
ancount = ntohs(hp->ancount); /* #/records in the answer section */
qdcount = ntohs(hp->qdcount); /* #/entries in the question section */
bp = netbuf;
buflen = sizeof(netbuf);
cp = answer->buf + HFIXEDSZ;
if (!qdcount) {
if (hp->aa)
h_errno = HOST_NOT_FOUND;
else
h_errno = TRY_AGAIN;
return (NULL);
}
while (qdcount-- > 0)
cp += __dn_skipname(cp, eom) + QFIXEDSZ;
ap = net_aliases;
*ap = NULL;
net_entry.n_aliases = net_aliases;
haveanswer = 0;
while (--ancount >= 0 && cp < eom) {
n = dn_expand(answer->buf, eom, cp, bp, buflen);
if ((n < 0) || !res_dnok(bp))
break;
cp += n;
ans[0] = '\0';
(void)strncpy(&ans[0], bp, sizeof(ans) - 1);
ans[sizeof(ans) - 1] = '\0';
GETSHORT(type, cp);
GETSHORT(class, cp);
cp += INT32SZ; /* TTL */
GETSHORT(n, cp);
if (class == C_IN && type == T_PTR) {
n = dn_expand(answer->buf, eom, cp, bp, buflen);
if ((n < 0) || !res_hnok(bp)) {
cp += n;
return (NULL);
}
cp += n;
*ap++ = bp;
bp += strlen(bp) + 1;
net_entry.n_addrtype =
(class == C_IN) ? AF_INET : AF_UNSPEC;
haveanswer++;
}
}
if (haveanswer) {
*ap = NULL;
switch (net_i) {
case BYADDR:
net_entry.n_name = *net_entry.n_aliases;
net_entry.n_net = 0L;
break;
case BYNAME:
in = *net_entry.n_aliases;
net_entry.n_name = &ans[0];
aux2[0] = '\0';
for (i = 0; i < 4; i++) {
for (st = in, nchar = 0;
*st != '.';
st++, nchar++)
;
if (nchar != 1 || *in != '0' || flag) {
flag = 1;
(void)strncpy(paux1,
(i==0) ? in : in-1,
(i==0) ?nchar : nchar+1);
paux1[(i==0) ? nchar : nchar+1] = '\0';
pauxt = paux2;
paux2 = strcat(paux1, paux2);
paux1 = pauxt;
}
in = ++st;
}
net_entry.n_net = inet_network(paux2);
break;
}
net_entry.n_aliases++;
return (&net_entry);
}
h_errno = TRY_AGAIN;
return (NULL);
}
struct netent *
_getnetbydnsaddr(net, net_type)
register unsigned long net;
register int net_type;
{
unsigned int netbr[4];
int nn, anslen;
querybuf buf;
char qbuf[MAXDNAME];
unsigned long net2;
struct netent *net_entry;
if (net_type != AF_INET)
return (NULL);
for (nn = 4, net2 = net; net2; net2 >>= 8)
netbr[--nn] = net2 & 0xff;
switch (nn) {
case 3: /* Class A */
sprintf(qbuf, "0.0.0.%u.in-addr.arpa", netbr[3]);
break;
case 2: /* Class B */
sprintf(qbuf, "0.0.%u.%u.in-addr.arpa", netbr[3], netbr[2]);
break;
case 1: /* Class C */
sprintf(qbuf, "0.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
netbr[1]);
break;
case 0: /* Class D - E */
sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", netbr[3], netbr[2],
netbr[1], netbr[0]);
break;
}
anslen = res_query(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
if (anslen < 0) {
#ifdef DEBUG
if (_res.options & RES_DEBUG)
printf("res_query failed\n");
#endif
return (NULL);
}
net_entry = getnetanswer(&buf, anslen, BYADDR);
if (net_entry) {
unsigned u_net = net; /* maybe net should be unsigned ? */
/* Strip trailing zeros */
while ((u_net & 0xff) == 0 && u_net != 0)
u_net >>= 8;
net_entry->n_net = u_net;
return (net_entry);
}
return (NULL);
}
struct netent *
_getnetbydnsname(net)
register const char *net;
{
int anslen;
querybuf buf;
char qbuf[MAXDNAME];
if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
h_errno = NETDB_INTERNAL;
return (NULL);
}
strncpy(qbuf, net, sizeof(qbuf) - 1);
qbuf[sizeof(qbuf) - 1] = '\0';
anslen = res_search(qbuf, C_IN, T_PTR, (u_char *)&buf, sizeof(buf));
if (anslen < 0) {
#ifdef DEBUG
if (_res.options & RES_DEBUG)
printf("res_query failed\n");
#endif
return (NULL);
}
return getnetanswer(&buf, anslen, BYNAME);
}
void
_setnetdnsent(stayopen)
int stayopen;
{
if (stayopen)
_res.options |= RES_STAYOPEN | RES_USEVC;
}
void
_endnetdnsent()
{
_res.options &= ~(RES_STAYOPEN | RES_USEVC);
res_close();
}
