475 lines
12 KiB
C
475 lines
12 KiB
C
/*-
|
|
* 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--
|
|
*/
|
|
|
|
#if defined(LIBC_SCCS) && !defined(lint)
|
|
static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93";
|
|
static char rcsid[] = "$Id: gethostbydns.c,v 1.1 1994/09/25 02:12:05 pst Exp $";
|
|
#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 <netdb.h>
|
|
#include <resolv.h>
|
|
#include <stdio.h>
|
|
#include <ctype.h>
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
#include <syslog.h>
|
|
|
|
#define BYADDR 0
|
|
#define BYNAME 1
|
|
|
|
#define MAXALIASES 35
|
|
#define MAXADDRS 35
|
|
|
|
#define MULTI_PTRS_ARE_ALIASES 1 /* XXX - experimental */
|
|
|
|
static const char AskedForGot[] =
|
|
"gethostby*.gethostanswer: asked for \"%s\", got \"%s\"";
|
|
|
|
static char *h_addr_ptrs[MAXADDRS + 1];
|
|
|
|
static struct hostent host;
|
|
static char *host_aliases[MAXALIASES];
|
|
static char hostbuf[8*1024];
|
|
static struct in_addr host_addr;
|
|
static FILE *hostf = NULL;
|
|
static char hostaddr[MAXADDRS];
|
|
static char *host_addrs[2];
|
|
static int stayopen = 0;
|
|
|
|
#if PACKETSZ > 1024
|
|
#define MAXPACKET PACKETSZ
|
|
#else
|
|
#define MAXPACKET 1024
|
|
#endif
|
|
|
|
typedef union {
|
|
HEADER hdr;
|
|
u_char buf[MAXPACKET];
|
|
} querybuf;
|
|
|
|
typedef union {
|
|
int32_t al;
|
|
char ac;
|
|
} align;
|
|
|
|
extern int h_errno;
|
|
|
|
#ifdef RESOLVSORT
|
|
static void
|
|
addrsort(ap, num)
|
|
char **ap;
|
|
int num;
|
|
{
|
|
int i, j;
|
|
char **p;
|
|
short aval[MAXADDRS];
|
|
int needsort = 0;
|
|
|
|
p = ap;
|
|
for (i = 0; i < num; i++, p++) {
|
|
for (j = 0 ; j < _res.nsort; j++)
|
|
if (_res.sort_list[j].addr.s_addr ==
|
|
(((struct in_addr *)(*p))->s_addr & _res.sort_list[j].mask))
|
|
break;
|
|
aval[i] = j;
|
|
if (needsort == 0 && i > 0 && j < aval[i-1])
|
|
needsort = i;
|
|
}
|
|
if (!needsort)
|
|
return;
|
|
|
|
while (needsort < num) {
|
|
for (j = needsort - 1; j >= 0; j--) {
|
|
if (aval[j] > aval[j+1]) {
|
|
char *hp;
|
|
|
|
i = aval[j];
|
|
aval[j] = aval[j+1];
|
|
aval[j+1] = i;
|
|
|
|
hp = ap[j];
|
|
ap[j] = ap[j+1];
|
|
ap[j+1] = hp;
|
|
|
|
} else
|
|
break;
|
|
}
|
|
needsort++;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static struct hostent *
|
|
gethostanswer(answer, anslen, qname, qclass, qtype)
|
|
const querybuf *answer;
|
|
int anslen;
|
|
const char *qname;
|
|
int qclass, qtype;
|
|
{
|
|
register const HEADER *hp;
|
|
register const u_char *cp;
|
|
register int n;
|
|
const u_char *eom;
|
|
char *bp, **ap, **hap;
|
|
int type, class, buflen, ancount, qdcount;
|
|
int haveanswer, had_error;
|
|
int toobig = 0;
|
|
char tbuf[MAXDNAME+1];
|
|
|
|
host.h_name = NULL;
|
|
eom = answer->buf + anslen;
|
|
/*
|
|
* find first satisfactory answer
|
|
*/
|
|
hp = &answer->hdr;
|
|
ancount = ntohs(hp->ancount);
|
|
qdcount = ntohs(hp->qdcount);
|
|
bp = hostbuf;
|
|
buflen = sizeof hostbuf;
|
|
cp = answer->buf + HFIXEDSZ;
|
|
if (qdcount != 1) {
|
|
h_errno = NO_RECOVERY;
|
|
return (NULL);
|
|
}
|
|
if ((n = dn_expand(answer->buf, eom, cp, bp, buflen)) < 0) {
|
|
h_errno = NO_RECOVERY;
|
|
return (NULL);
|
|
}
|
|
cp += n + QFIXEDSZ;
|
|
if (qtype == T_A) {
|
|
/* res_send() has already verified that the query name is the
|
|
* same as the one we sent; this just gets the expanded name
|
|
* (i.e., with the succeeding search-domain tacked on).
|
|
*/
|
|
n = strlen(bp) + 1; /* for the \0 */
|
|
host.h_name = bp;
|
|
bp += n;
|
|
buflen -= n;
|
|
/* The qname can be abbreviated, but h_name is now absolute. */
|
|
qname = host.h_name;
|
|
}
|
|
ap = host_aliases;
|
|
*ap = NULL;
|
|
host.h_aliases = host_aliases;
|
|
hap = h_addr_ptrs;
|
|
*hap = NULL;
|
|
host.h_addr_list = h_addr_ptrs;
|
|
haveanswer = 0;
|
|
had_error = 0;
|
|
while (ancount-- > 0 && cp < eom && !had_error) {
|
|
n = dn_expand(answer->buf, eom, cp, bp, buflen);
|
|
if (n < 0) {
|
|
had_error++;
|
|
continue;
|
|
}
|
|
cp += n; /* name */
|
|
type = _getshort(cp);
|
|
cp += INT16SZ; /* type */
|
|
class = _getshort(cp);
|
|
cp += INT16SZ + INT32SZ; /* class, TTL */
|
|
n = _getshort(cp);
|
|
cp += INT16SZ; /* len */
|
|
if (class != qclass) {
|
|
/* XXX - debug? syslog? */
|
|
cp += n;
|
|
continue; /* XXX - had_error++ ? */
|
|
}
|
|
if (qtype == T_A && type == T_CNAME) {
|
|
if (ap >= &host_aliases[MAXALIASES-1])
|
|
continue;
|
|
n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
|
|
if (n < 0) {
|
|
had_error++;
|
|
continue;
|
|
}
|
|
cp += n;
|
|
if (host.h_name && strcasecmp(host.h_name, bp) != 0) {
|
|
syslog(LOG_NOTICE|LOG_AUTH,
|
|
"gethostby*.getanswer: asked for \"%s\", got CNAME for \"%s\"",
|
|
host.h_name, bp);
|
|
continue; /* XXX - had_error++ ? */
|
|
}
|
|
/* Store alias. */
|
|
*ap++ = bp;
|
|
n = strlen(bp) + 1; /* for the \0 */
|
|
bp += n;
|
|
buflen -= n;
|
|
/* Get canonical name. */
|
|
n = strlen(tbuf) + 1; /* for the \0 */
|
|
if (n > buflen) {
|
|
had_error++;
|
|
continue;
|
|
}
|
|
strcpy(bp, tbuf);
|
|
host.h_name = bp;
|
|
bp += n;
|
|
buflen -= n;
|
|
continue;
|
|
}
|
|
if (type != qtype) {
|
|
syslog(LOG_NOTICE|LOG_AUTH,
|
|
"gethostby*.getanswer: asked for type %d(%s), got %d(%s)",
|
|
qtype, qname, type, bp);
|
|
cp += n;
|
|
continue; /* XXX - had_error++ ? */
|
|
}
|
|
switch (type) {
|
|
case T_PTR:
|
|
if (strcasecmp(qname, bp) != 0) {
|
|
syslog(LOG_NOTICE|LOG_AUTH,
|
|
AskedForGot, qname, bp);
|
|
cp += n;
|
|
continue; /* XXX - had_error++ ? */
|
|
}
|
|
n = dn_expand(answer->buf, eom, cp, bp, buflen);
|
|
if (n < 0) {
|
|
had_error++;
|
|
break;
|
|
}
|
|
#if MULTI_PTRS_ARE_ALIASES
|
|
cp += n;
|
|
if (!haveanswer)
|
|
host.h_name = bp;
|
|
else if (ap < &host_aliases[MAXALIASES-1])
|
|
*ap++ = bp;
|
|
else
|
|
n = -1;
|
|
if (n != -1) {
|
|
n = strlen(bp) + 1; /* for the \0 */
|
|
bp += n;
|
|
buflen -= n;
|
|
}
|
|
break;
|
|
#else
|
|
host.h_name = bp;
|
|
return (&host);
|
|
#endif
|
|
case T_A:
|
|
if (strcasecmp(host.h_name, bp) != 0) {
|
|
syslog(LOG_NOTICE|LOG_AUTH,
|
|
AskedForGot, host.h_name, bp);
|
|
cp += n;
|
|
continue; /* XXX - had_error++ ? */
|
|
}
|
|
if (haveanswer) {
|
|
if (n != host.h_length) {
|
|
cp += n;
|
|
continue;
|
|
}
|
|
} else {
|
|
register int nn;
|
|
|
|
host.h_length = n;
|
|
host.h_addrtype = (class == C_IN)
|
|
? AF_INET
|
|
: AF_UNSPEC;
|
|
host.h_name = bp;
|
|
nn = strlen(bp) + 1; /* for the \0 */
|
|
bp += nn;
|
|
buflen -= nn;
|
|
}
|
|
|
|
bp += sizeof(align) - ((u_long)bp % sizeof(align));
|
|
|
|
if (bp + n >= &hostbuf[sizeof hostbuf]) {
|
|
if (_res.options & RES_DEBUG)
|
|
printf("size (%d) too big\n", n);
|
|
had_error++;
|
|
continue;
|
|
}
|
|
if (hap >= &h_addr_ptrs[MAXADDRS-1]) {
|
|
if (_res.options & RES_DEBUG && !toobig++)
|
|
printf("Too many addresses (%d)\n",
|
|
MAXADDRS);
|
|
cp += n;
|
|
continue;
|
|
}
|
|
bcopy(cp, *hap++ = bp, n);
|
|
bp += n;
|
|
cp += n;
|
|
break;
|
|
default:
|
|
abort();
|
|
} /*switch*/
|
|
if (!had_error)
|
|
haveanswer++;
|
|
} /*while*/
|
|
if (haveanswer) {
|
|
*ap = NULL;
|
|
*hap = NULL;
|
|
# if defined(RESOLVSORT)
|
|
/*
|
|
* Note: we sort even if host can take only one address
|
|
* in its return structures - should give it the "best"
|
|
* address in that case, not some random one
|
|
*/
|
|
if (_res.nsort && haveanswer > 1 &&
|
|
qclass == C_IN && qtype == T_A)
|
|
addrsort(h_addr_ptrs, haveanswer);
|
|
# endif /*RESOLVSORT*/
|
|
if (!host.h_name) {
|
|
n = strlen(qname) + 1; /* for the \0 */
|
|
strcpy(bp, qname);
|
|
host.h_name = bp;
|
|
}
|
|
return (&host);
|
|
} else {
|
|
h_errno = TRY_AGAIN;
|
|
return (NULL);
|
|
}
|
|
}
|
|
|
|
struct hostent *
|
|
_gethostbydnsname(name)
|
|
const char *name;
|
|
{
|
|
querybuf buf;
|
|
register const char *cp;
|
|
int n;
|
|
|
|
/*
|
|
* disallow names consisting only of digits/dots, unless
|
|
* they end in a dot.
|
|
*/
|
|
if (isdigit(name[0]))
|
|
for (cp = name;; ++cp) {
|
|
if (!*cp) {
|
|
if (*--cp == '.')
|
|
break;
|
|
/*
|
|
* All-numeric, no dot at the end.
|
|
* Fake up a hostent as if we'd actually
|
|
* done a lookup.
|
|
*/
|
|
if (!inet_aton(name, &host_addr)) {
|
|
h_errno = HOST_NOT_FOUND;
|
|
return (NULL);
|
|
}
|
|
host.h_name = (char *)name;
|
|
host.h_aliases = host_aliases;
|
|
host_aliases[0] = NULL;
|
|
host.h_addrtype = AF_INET;
|
|
host.h_length = INT32SZ;
|
|
h_addr_ptrs[0] = (char *)&host_addr;
|
|
h_addr_ptrs[1] = NULL;
|
|
host.h_addr_list = h_addr_ptrs;
|
|
return (&host);
|
|
}
|
|
if (!isdigit(*cp) && *cp != '.')
|
|
break;
|
|
}
|
|
|
|
if ((n = res_search(name, C_IN, T_A, buf.buf, sizeof(buf))) < 0) {
|
|
if (_res.options & RES_DEBUG)
|
|
printf("res_search failed\n");
|
|
return (NULL);
|
|
}
|
|
return (gethostanswer(&buf, n, name, C_IN, T_A));
|
|
}
|
|
|
|
struct hostent *
|
|
_gethostbydnsaddr(addr, len, type)
|
|
const char *addr;
|
|
int len, type;
|
|
{
|
|
int n;
|
|
querybuf buf;
|
|
register struct hostent *hp;
|
|
char qbuf[MAXDNAME+1];
|
|
|
|
if (type != AF_INET)
|
|
return (NULL);
|
|
(void)sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa",
|
|
((unsigned)addr[3] & 0xff),
|
|
((unsigned)addr[2] & 0xff),
|
|
((unsigned)addr[1] & 0xff),
|
|
((unsigned)addr[0] & 0xff));
|
|
n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf.buf, sizeof buf.buf);
|
|
if (n < 0) {
|
|
if (_res.options & RES_DEBUG)
|
|
printf("res_query failed\n");
|
|
return (NULL);
|
|
}
|
|
if (!(hp = gethostanswer(&buf, n, qbuf, C_IN, T_PTR)))
|
|
return (NULL);
|
|
hp->h_addrtype = type;
|
|
hp->h_length = len;
|
|
h_addr_ptrs[0] = (char *)&host_addr;
|
|
h_addr_ptrs[1] = NULL;
|
|
host_addr = *(struct in_addr *)addr;
|
|
#if BSD < 43 && !defined(h_addr) /* new-style hostent structure */
|
|
hp->h_addr = h_addr_ptrs[0];
|
|
#endif
|
|
return (hp);
|
|
}
|
|
|
|
void
|
|
_sethostdnsent(stayopen)
|
|
int stayopen;
|
|
{
|
|
if (stayopen)
|
|
_res.options |= RES_STAYOPEN | RES_USEVC;
|
|
}
|
|
|
|
void
|
|
_endhostdnsent()
|
|
{
|
|
_res.options &= ~(RES_STAYOPEN | RES_USEVC);
|
|
_res_close();
|
|
}
|