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freebsd-dev/usr.sbin/nslookup/getinfo.c

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nslookup(8) from BIND 4.9.3BETA9pl1
1994-09-22 21:36:02 +00:00
/*
* ++Copyright++ 1985, 1989
* -
* Copyright (c) 1985, 1989
* 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--
*/
#ifndef lint
static char sccsid[] = "@(#)getinfo.c 5.26 (Berkeley) 3/21/91";
static char rcsid[] = "$Id: getinfo.c,v 4.9.1.6 1994/06/01 21:10:16 vixie Exp $";
#endif /* not lint */
/*
******************************************************************************
*
* getinfo.c --
*
* Routines to create requests to name servers
* and interpret the answers.
*
* Adapted from 4.3BSD BIND gethostnamadr.c
*
******************************************************************************
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>
#include <resolv.h>
#include <stdio.h>
#include <ctype.h>
#include "res.h"
#include "../../conf/portability.h"
extern char *_res_resultcodes[];
extern char *res_skip();
#define MAXALIASES 35
#define MAXADDRS 35
#define MAXDOMAINS 35
#define MAXSERVERS 10
static char *addr_list[MAXADDRS + 1];
static char *host_aliases[MAXALIASES];
static int host_aliases_len[MAXALIASES];
static u_char hostbuf[BUFSIZ+1];
typedef struct {
char *name;
char *domain[MAXDOMAINS];
int numDomains;
char *address[MAXADDRS];
int numAddresses;
} ServerTable;
ServerTable server[MAXSERVERS];
typedef union {
HEADER qb1;
u_char qb2[PACKETSZ*2];
} querybuf;
typedef union {
int32_t al;
char ac;
} align;
#define GetShort(cp) _getshort(cp); cp += INT16SZ;
/*
******************************************************************************
*
* GetAnswer --
*
* Interprets an answer packet and retrieves the following
* information:
*
* Results:
* SUCCESS the info was retrieved.
* NO_INFO the packet did not contain an answer.
* NONAUTH non-authoritative information was found.
* ERROR the answer was malformed.
* Other errors returned in the packet header.
*
******************************************************************************
*/
static int
GetAnswer(nsAddrPtr, queryType, msg, msglen, iquery, hostPtr, isServer)
struct in_addr *nsAddrPtr;
char *msg;
int queryType;
int msglen;
Boolean iquery;
register HostInfo *hostPtr;
Boolean isServer;
{
register HEADER *headerPtr;
register u_char *cp;
querybuf answer;
char **aliasPtr;
u_char *eom, *bp;
char **addrPtr;
char *namePtr;
char *dnamePtr;
int type, class;
int qdcount, ancount, arcount, nscount, buflen;
int origClass;
int numAliases = 0;
int numAddresses = 0;
int n, i, j;
int len;
int dlen;
int status;
int numServers;
Boolean haveAnswer;
Boolean printedAnswers = FALSE;
/*
* If the hostPtr was used before, free up the calloc'd areas.
*/
FreeHostInfoPtr(hostPtr);
status = SendRequest(nsAddrPtr, msg, msglen, (char *) &answer,
sizeof(answer), &n);
if (status != SUCCESS) {
if (_res.options & RES_DEBUG2)
printf("SendRequest failed\n");
return (status);
}
eom = (u_char *) &answer + n;
headerPtr = (HEADER *) &answer;
if (headerPtr->rcode != NOERROR) {
return (headerPtr->rcode);
}
qdcount = ntohs(headerPtr->qdcount);
ancount = ntohs(headerPtr->ancount);
arcount = ntohs(headerPtr->arcount);
nscount = ntohs(headerPtr->nscount);
/*
* If there are no answer, n.s. or additional records
* then return with an error.
*/
if (ancount == 0 && nscount == 0 && arcount == 0) {
return (NO_INFO);
}
bp = hostbuf;
buflen = sizeof(hostbuf);
cp = (u_char *) &answer + HFIXEDSZ;
/* Skip over question section. */
while (qdcount-- > 0) {
cp += dn_skipname(cp, eom) + QFIXEDSZ;
}
aliasPtr = host_aliases;
addrPtr = addr_list;
haveAnswer = FALSE;
/*
* Scan through the answer resource records.
* Answers for address query types are saved.
* Other query type answers are just printed.
*/
if (ancount != 0) {
if (!isServer && !headerPtr->aa) {
printf("Non-authoritative answer:\n");
}
if (queryType != T_A && !(iquery && queryType == T_PTR)) {
while (--ancount >= 0 && cp < eom) {
if ((cp = (u_char *)Print_rr(cp,
(char *)&answer, eom, stdout)) == NULL) {
return(ERROR);
}
}
printedAnswers = TRUE;
} else {
while (--ancount >= 0 && cp < eom) {
n = dn_expand(answer.qb2, eom, cp, (char *)bp, buflen);
if (n < 0) {
return(ERROR);
}
cp += n;
type = GetShort(cp);
class = GetShort(cp);
cp += INT32SZ; /* skip TTL */
dlen = GetShort(cp);
if (type == T_CNAME) {
/*
* Found an alias.
*/
cp += dlen;
if (aliasPtr >= &host_aliases[MAXALIASES-1]) {
continue;
}
*aliasPtr++ = (char *)bp;
n = strlen((char *)bp) + 1;
host_aliases_len[numAliases] = n;
numAliases++;
bp += n;
buflen -= n;
continue;
} else if (type == T_PTR) {
/*
* Found a "pointer" to the real name.
*/
n = dn_expand(answer.qb2, eom, cp, (char *)bp, buflen);
if (n < 0) {
cp += n;
continue;
}
cp += n;
len = strlen((char *)bp) + 1;
hostPtr->name = Calloc(1, len);
bcopy(bp, hostPtr->name, len);
haveAnswer = TRUE;
break;
} else if (type != T_A) {
cp += dlen;
continue;
}
if (haveAnswer) {
/*
* If we've already got 1 address, we aren't interested
* in addresses with a different length or class.
*/
if (dlen != hostPtr->addrLen) {
cp += dlen;
continue;
}
if (class != origClass) {
cp += dlen;
continue;
}
} else {
/*
* First address: record its length and class so we
* only save additonal ones with the same attributes.
*/
hostPtr->addrLen = dlen;
origClass = class;
hostPtr->addrType = (class == C_IN) ? AF_INET : AF_UNSPEC;
len = strlen((char *)bp) + 1;
hostPtr->name = Calloc(1, len);
bcopy(bp, hostPtr->name, len);
}
bp += (((u_int32_t)bp) % sizeof(align));
if (bp + dlen >= &hostbuf[sizeof(hostbuf)]) {
if (_res.options & RES_DEBUG) {
printf("Size (%d) too big\n", dlen);
}
break;
}
bcopy(cp, *addrPtr++ = (char *)bp, dlen);
bp +=dlen;
cp += dlen;
numAddresses++;
haveAnswer = TRUE;
}
}
}
if ((queryType == T_A || queryType == T_PTR) && haveAnswer) {
/*
* Go through the alias and address lists and return them
* in the hostPtr variable.
*/
if (numAliases > 0) {
hostPtr->aliases =
(char **) Calloc(1 + numAliases, sizeof(char *));
for (i = 0; i < numAliases; i++) {
hostPtr->aliases[i] = Calloc(1, host_aliases_len[i]);
bcopy(host_aliases[i],
hostPtr->aliases[i],
host_aliases_len[i]);
}
hostPtr->aliases[i] = NULL;
}
if (numAddresses > 0) {
hostPtr->addrList =
(char **)Calloc(1+numAddresses, sizeof(char *));
for (i = 0; i < numAddresses; i++) {
hostPtr->addrList[i] = Calloc(1, hostPtr->addrLen);
bcopy(addr_list[i], hostPtr->addrList[i], hostPtr->addrLen);
}
hostPtr->addrList[i] = NULL;
}
#ifdef verbose
if (headerPtr->aa || nscount == 0) {
hostPtr->servers = NULL;
return (SUCCESS);
}
#else
hostPtr->servers = NULL;
return (SUCCESS);
#endif
}
/*
* At this point, for the T_A query type, only empty answers remain.
* For other query types, additional information might be found
* in the additional resource records part.
*/
if (!headerPtr->aa && (queryType != T_A) && (nscount > 0 || arcount > 0)) {
if (printedAnswers) {
putchar('\n');
}
printf("Authoritative answers can be found from:\n");
}
cp = (u_char *)res_skip((char *) &answer, 2, eom);
numServers = 0;
if (queryType != T_A) {
/*
* If we don't need to save the record, just print it.
*/
while (--nscount >= 0 && cp < eom) {
if ((cp = (u_char *)Print_rr(cp,
(char *) &answer, eom, stdout)) == NULL) {
return(ERROR);
}
}
} else {
while (--nscount >= 0 && cp < eom) {
/*
* Go through the NS records and retrieve the names of hosts
* that serve the requested domain.
*/
n = dn_expand(answer.qb2, eom, cp, (char *)bp, buflen);
if (n < 0) {
return(ERROR);
}
cp += n;
len = strlen((char *)bp) + 1;
dnamePtr = Calloc(1, len); /* domain name */
bcopy(bp, dnamePtr, len);
type = GetShort(cp);
class = GetShort(cp);
cp += INT32SZ; /* skip TTL */
dlen = GetShort(cp);
if (type != T_NS) {
cp += dlen;
} else {
Boolean found;
n = dn_expand(answer.qb2, eom, cp, (char *)bp, buflen);
if (n < 0) {
return(ERROR);
}
cp += n;
len = strlen((char *)bp) + 1;
namePtr = Calloc(1, len); /* server host name */
bcopy(bp, namePtr, len);
/*
* Store the information keyed by the server host name.
*/
found = FALSE;
for (j = 0; j < numServers; j++) {
if (strcmp(namePtr, server[j].name) == 0) {
found = TRUE;
free(namePtr);
break;
}
}
if (found) {
server[j].numDomains++;
if (server[j].numDomains <= MAXDOMAINS) {
server[j].domain[server[j].numDomains-1] = dnamePtr;
}
} else {
if (numServers >= MAXSERVERS) {
break;
}
server[numServers].name = namePtr;
server[numServers].domain[0] = dnamePtr;
server[numServers].numDomains = 1;
server[numServers].numAddresses = 0;
numServers++;
}
}
}
}
/*
* Additional resource records contain addresses of servers.
*/
cp = (u_char *)res_skip((char *) &answer, 3, eom);
if (queryType != T_A) {
/*
* If we don't need to save the record, just print it.
*/
while (--arcount >= 0 && cp < eom) {
if ((cp = (u_char *)Print_rr(cp,
(char *) &answer, eom, stdout)) == NULL) {
return(ERROR);
}
}
} else {
while (--arcount >= 0 && cp < eom) {
n = dn_expand(answer.qb2, eom, cp, (char *)bp, buflen);
if (n < 0) {
break;
}
cp += n;
type = GetShort(cp);
class = GetShort(cp);
cp += INT32SZ; /* skip TTL */
dlen = GetShort(cp);
if (type != T_A) {
cp += dlen;
continue;
} else {
for (j = 0; j < numServers; j++) {
if (strcmp((char *)bp, server[j].name) == 0) {
server[j].numAddresses++;
if (server[j].numAddresses <= MAXADDRS) {
server[j].address[server[j].numAddresses-1] =
Calloc(1,dlen);
bcopy(cp,
server[j].address[server[j].numAddresses-1],dlen);
break;
}
}
}
cp += dlen;
}
}
}
/*
* If we are returning name server info, transfer it to the hostPtr.
*/
if (numServers > 0) {
hostPtr->servers = (ServerInfo **)
Calloc(numServers+1, sizeof(ServerInfo *));
for (i = 0; i < numServers; i++) {
hostPtr->servers[i] = (ServerInfo *) Calloc(1, sizeof(ServerInfo));
hostPtr->servers[i]->name = server[i].name;
hostPtr->servers[i]->domains = (char **)
Calloc(server[i].numDomains+1,sizeof(char *));
for (j = 0; j < server[i].numDomains; j++) {
hostPtr->servers[i]->domains[j] = server[i].domain[j];
}
hostPtr->servers[i]->domains[j] = NULL;
hostPtr->servers[i]->addrList = (char **)
Calloc(server[i].numAddresses+1,sizeof(char *));
for (j = 0; j < server[i].numAddresses; j++) {
hostPtr->servers[i]->addrList[j] = server[i].address[j];
}
hostPtr->servers[i]->addrList[j] = NULL;
}
hostPtr->servers[i] = NULL;
}
switch (queryType) {
case T_A:
return NONAUTH;
case T_PTR:
if (iquery)
return NO_INFO;
/* fall through */
default:
return SUCCESS;
}
}
/*
*******************************************************************************
*
* GetHostInfo --
*
* Retrieves host name, address and alias information
* for a domain.
*
* Algorithm from res_search().
*
* Results:
* ERROR - res_mkquery failed.
* + return values from GetAnswer()
*
*******************************************************************************
*/
int
GetHostInfoByName(nsAddrPtr, queryClass, queryType, name, hostPtr, isServer)
struct in_addr *nsAddrPtr;
int queryClass;
int queryType;
char *name;
HostInfo *hostPtr;
Boolean isServer;
{
int n;
register int result;
register char *cp, **domain;
Boolean got_nodata = FALSE;
struct in_addr ina;
/* Catch explicit addresses */
if ((queryType == T_A) && IsAddr(name, &ina)) {
hostPtr->name = Calloc(strlen(name)+3, 1);
(void)sprintf(hostPtr->name,"[%s]",name);
hostPtr->aliases = NULL;
hostPtr->servers = NULL;
hostPtr->addrType = AF_INET;
hostPtr->addrLen = INADDRSZ;
hostPtr->addrList = (char **)Calloc(2, sizeof(char *));
hostPtr->addrList[0] = Calloc(INT32SZ, sizeof(char));
bcopy((char *)&ina, hostPtr->addrList[0], INADDRSZ);
hostPtr->addrList[1] = NULL;
return(SUCCESS);
}
result = NXDOMAIN;
for (cp = name, n = 0; *cp; cp++)
if (*cp == '.')
n++;
if (n == 0 && (cp = hostalias(name))) {
printf("Aliased to \"%s\"\n\n", cp);
return (GetHostDomain(nsAddrPtr, queryClass, queryType,
cp, (char *)NULL, hostPtr, isServer));
}
/*
* We do at least one level of search if
* - there is no dot and RES_DEFNAME is set, or
* - there is at least one dot, there is no trailing dot,
* and RES_DNSRCH is set.
*/
if ((n == 0 && _res.options & RES_DEFNAMES) ||
(n != 0 && *--cp != '.' && _res.options & RES_DNSRCH))
for (domain = _res.dnsrch; *domain; domain++) {
result = GetHostDomain(nsAddrPtr, queryClass, queryType,
name, *domain, hostPtr, isServer);
/*
* If no server present, give up.
* If name isn't found in this domain,
* keep trying higher domains in the search list
* (if that's enabled).
* On a NO_INFO error, keep trying, otherwise
* a wildcard entry of another type could keep us
* from finding this entry higher in the domain.
* If we get some other error (negative answer or
* server failure), then stop searching up,
* but try the input name below in case it's fully-qualified.
*/
if (result == SUCCESS || result == NO_RESPONSE)
return result;
if (result == NO_INFO)
got_nodata++;
if ((result != NXDOMAIN && result != NO_INFO) ||
(_res.options & RES_DNSRCH) == 0)
break;
}
/*
* If the search/default failed, try the name as fully-qualified,
* but only if it contained at least one dot (even trailing).
* This is purely a heuristic; we assume that any reasonable query
* about a top-level domain (for servers, SOA, etc) will not use
* res_search.
*/
if (n && (result = GetHostDomain(nsAddrPtr, queryClass, queryType,
name, (char *)NULL, hostPtr, isServer)) == SUCCESS)
return result;
if (got_nodata)
result = NO_INFO;
return (result);
}
/*
* Perform a query on the concatenation of name and domain,
* removing a trailing dot from name if domain is NULL.
*/
GetHostDomain(nsAddrPtr, queryClass, queryType, name, domain, hostPtr, isServer)
struct in_addr *nsAddrPtr;
int queryClass;
int queryType;
char *name, *domain;
HostInfo *hostPtr;
Boolean isServer;
{
querybuf buf;
char nbuf[2*MAXDNAME+2];
char *longname = nbuf;
int n;
if (domain == NULL) {
/*
* Check for trailing '.';
* copy without '.' if present.
*/
n = strlen(name) - 1;
if (name[n] == '.' && n < sizeof(nbuf) - 1) {
bcopy(name, nbuf, n);
nbuf[n] = '\0';
} else
longname = name;
} else {
(void)sprintf(nbuf, "%.*s.%.*s",
MAXDNAME, name, MAXDNAME, domain);
longname = nbuf;
}
n = res_mkquery(QUERY, longname, queryClass, queryType,
NULL, 0, 0, buf.qb2, sizeof(buf));
if (n < 0) {
if (_res.options & RES_DEBUG) {
printf("Res_mkquery failed\n");
}
return (ERROR);
}
n = GetAnswer(nsAddrPtr, queryType, (char *)&buf, n, 0, hostPtr, isServer);
/*
* GetAnswer didn't find a name, so set it to the specified one.
*/
if (n == NONAUTH) {
if (hostPtr->name == NULL) {
int len = strlen(longname) + 1;
hostPtr->name = Calloc(len, sizeof(char));
bcopy(longname, hostPtr->name, len);
}
}
return(n);
}
/*
*******************************************************************************
*
* GetHostInfoByAddr --
*
* Performs a PTR lookup in in-addr.arpa to find the host name
* that corresponds to the given address.
*
* Results:
* ERROR - res_mkquery failed.
* + return values from GetAnswer()
*
*******************************************************************************
*/
int
GetHostInfoByAddr(nsAddrPtr, address, hostPtr)
struct in_addr *nsAddrPtr;
struct in_addr *address;
HostInfo *hostPtr;
{
int n;
querybuf buf;
char qbuf[MAXDNAME];
char *p = (char *) &address->s_addr;
(void)sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa",
((unsigned)p[3] & 0xff),
((unsigned)p[2] & 0xff),
((unsigned)p[1] & 0xff),
((unsigned)p[0] & 0xff));
n = res_mkquery(QUERY, qbuf, C_IN, T_PTR, NULL, 0, NULL,
buf.qb2, sizeof buf);
if (n < 0) {
if (_res.options & RES_DEBUG) {
printf("res_mkquery() failed\n");
}
return (ERROR);
}
n = GetAnswer(nsAddrPtr, T_PTR, (char *) &buf, n, 1, hostPtr, 1);
if (n == SUCCESS) {
hostPtr->addrType = AF_INET;
hostPtr->addrLen = 4;
hostPtr->addrList = (char **)Calloc(2, sizeof(char *));
hostPtr->addrList[0] = Calloc(INT32SZ, sizeof(char));
bcopy((char *)p, hostPtr->addrList[0], INADDRSZ);
hostPtr->addrList[1] = NULL;
}
return n;
}
/*
*******************************************************************************
*
* FreeHostInfoPtr --
*
* Deallocates all the calloc'd areas for a HostInfo variable.
*
*******************************************************************************
*/
void
FreeHostInfoPtr(hostPtr)
register HostInfo *hostPtr;
{
int i, j;
if (hostPtr->name != NULL) {
free(hostPtr->name);
hostPtr->name = NULL;
}
if (hostPtr->aliases != NULL) {
i = 0;
while (hostPtr->aliases[i] != NULL) {
free(hostPtr->aliases[i]);
i++;
}
free((char *)hostPtr->aliases);
hostPtr->aliases = NULL;
}
if (hostPtr->addrList != NULL) {
i = 0;
while (hostPtr->addrList[i] != NULL) {
free(hostPtr->addrList[i]);
i++;
}
free((char *)hostPtr->addrList);
hostPtr->addrList = NULL;
}
if (hostPtr->servers != NULL) {
i = 0;
while (hostPtr->servers[i] != NULL) {
if (hostPtr->servers[i]->name != NULL) {
free(hostPtr->servers[i]->name);
}
if (hostPtr->servers[i]->domains != NULL) {
j = 0;
while (hostPtr->servers[i]->domains[j] != NULL) {
free(hostPtr->servers[i]->domains[j]);
j++;
}
free((char *)hostPtr->servers[i]->domains);
}
if (hostPtr->servers[i]->addrList != NULL) {
j = 0;
while (hostPtr->servers[i]->addrList[j] != NULL) {
free(hostPtr->servers[i]->addrList[j]);
j++;
}
free((char *)hostPtr->servers[i]->addrList);
}
free((char *)hostPtr->servers[i]);
i++;
}
free((char *)hostPtr->servers);
hostPtr->servers = NULL;
}
}
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