mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-25 11:37:56 +00:00
15b23bddd9
suffix attempts before failing. No need to try again by hand, particularly when it fills your log with failures because localhost.example.com..example.com fails to resolve. Also improve the log message that helped find this error. There is still (maybe) an uninitialised pointer problem here, but in a month of testing I haven't triggered it.
525 lines
12 KiB
C
525 lines
12 KiB
C
/*
|
|
* Copyright (c) 1995, 1996
|
|
* Bill Paul <wpaul@ctr.columbia.edu>. 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 Bill Paul.
|
|
* 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 Bill Paul 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 Bill Paul 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.
|
|
*/
|
|
|
|
#ifndef lint
|
|
static const char rcsid[] =
|
|
"$FreeBSD$";
|
|
#endif /* not lint */
|
|
|
|
/*
|
|
* Do standard and reverse DNS lookups using the resolver library.
|
|
* Take care of all the dirty work here so the main program only has to
|
|
* pass us a pointer to an array of characters.
|
|
*
|
|
* We have to use direct resolver calls here otherwise the YP server
|
|
* could end up looping by calling itself over and over again until
|
|
* it disappeared up its own belly button.
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/time.h>
|
|
#include <sys/fcntl.h>
|
|
#include <sys/queue.h>
|
|
#include <netinet/in.h>
|
|
#include <arpa/inet.h>
|
|
#include <arpa/nameser.h>
|
|
|
|
#include <ctype.h>
|
|
#include <errno.h>
|
|
#include <netdb.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <resolv.h>
|
|
#include <unistd.h>
|
|
|
|
#include <rpcsvc/yp.h>
|
|
#include "yp_extern.h"
|
|
|
|
static char *
|
|
parse(struct hostent *hp)
|
|
{
|
|
static char result[MAXHOSTNAMELEN * 2];
|
|
int len,i;
|
|
struct in_addr addr;
|
|
|
|
if (hp == NULL)
|
|
return(NULL);
|
|
|
|
len = 16 + strlen(hp->h_name);
|
|
for (i = 0; hp->h_aliases[i]; i++)
|
|
len += strlen(hp->h_aliases[i]) + 1;
|
|
len++;
|
|
|
|
if (len > sizeof(result))
|
|
return(NULL);
|
|
|
|
bzero(result, sizeof(result));
|
|
|
|
bcopy(hp->h_addr, &addr, sizeof(struct in_addr));
|
|
snprintf(result, sizeof(result), "%s %s", inet_ntoa(addr), hp->h_name);
|
|
|
|
for (i = 0; hp->h_aliases[i]; i++) {
|
|
strcat(result, " ");
|
|
strcat(result, hp->h_aliases[i]);
|
|
}
|
|
|
|
return ((char *)&result);
|
|
}
|
|
|
|
#define MAXPACKET 1024
|
|
#define DEF_TTL 50
|
|
|
|
#define BY_DNS_ID 1
|
|
#define BY_RPC_XID 2
|
|
|
|
extern struct hostent *__dns_getanswer(char *, int, char *, int);
|
|
|
|
static TAILQ_HEAD(dns_qhead, circleq_dnsentry) qhead;
|
|
|
|
struct circleq_dnsentry {
|
|
SVCXPRT *xprt;
|
|
unsigned long xid;
|
|
struct sockaddr_in client_addr;
|
|
unsigned long ypvers;
|
|
unsigned long id;
|
|
unsigned long ttl;
|
|
unsigned long type;
|
|
unsigned short prot_type;
|
|
char **domain;
|
|
char *name;
|
|
struct in_addr addr;
|
|
TAILQ_ENTRY(circleq_dnsentry) links;
|
|
};
|
|
|
|
static int pending = 0;
|
|
|
|
int
|
|
yp_init_resolver(void)
|
|
{
|
|
TAILQ_INIT(&qhead);
|
|
if (!(_res.options & RES_INIT) && res_init() == -1) {
|
|
yp_error("res_init failed");
|
|
return(1);
|
|
}
|
|
if ((resfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
|
|
yp_error("couldn't create socket");
|
|
return(1);
|
|
}
|
|
if (fcntl(resfd, F_SETFL, O_NONBLOCK) == -1) {
|
|
yp_error("couldn't make resolver socket non-blocking");
|
|
return(1);
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
static struct
|
|
circleq_dnsentry *yp_malloc_dnsent(void)
|
|
{
|
|
register struct circleq_dnsentry *q;
|
|
|
|
q = (struct circleq_dnsentry *)malloc(sizeof(struct circleq_dnsentry));
|
|
|
|
if (q == NULL) {
|
|
yp_error("failed to malloc() circleq dns entry");
|
|
return(NULL);
|
|
}
|
|
|
|
return(q);
|
|
}
|
|
|
|
/*
|
|
* Transmit a query.
|
|
*/
|
|
static unsigned long
|
|
yp_send_dns_query(char *name, int type)
|
|
{
|
|
char buf[MAXPACKET];
|
|
int n;
|
|
HEADER *hptr;
|
|
int ns;
|
|
int rval;
|
|
unsigned long id;
|
|
|
|
bzero(buf, sizeof(buf));
|
|
|
|
n = res_mkquery(QUERY,name,C_IN,type,NULL,0,NULL,buf,sizeof(buf));
|
|
|
|
if (n <= 0) {
|
|
yp_error("res_mkquery failed for %s type %d", name, type);
|
|
return(0);
|
|
}
|
|
|
|
hptr = (HEADER *)&buf;
|
|
id = ntohs(hptr->id);
|
|
|
|
for (ns = 0; ns < _res.nscount; ns++) {
|
|
rval = sendto(resfd, buf, n, 0,
|
|
(struct sockaddr *)&_res.nsaddr_list[ns],
|
|
sizeof(struct sockaddr));
|
|
if (rval == -1) {
|
|
yp_error("sendto failed");
|
|
return(0);
|
|
}
|
|
}
|
|
|
|
return(id);
|
|
}
|
|
|
|
static struct circleq_dnsentry *
|
|
yp_find_dnsqent(unsigned long id, int type)
|
|
{
|
|
register struct circleq_dnsentry *q;
|
|
|
|
TAILQ_FOREACH(q, &qhead, links) {
|
|
switch (type) {
|
|
case BY_RPC_XID:
|
|
if (id == q->xid)
|
|
return(q);
|
|
break;
|
|
case BY_DNS_ID:
|
|
default:
|
|
if (id == q->id)
|
|
return(q);
|
|
break;
|
|
}
|
|
}
|
|
return (NULL);
|
|
}
|
|
|
|
static void
|
|
yp_send_dns_reply(struct circleq_dnsentry *q, char *buf)
|
|
{
|
|
ypresponse result_v1;
|
|
ypresp_val result_v2;
|
|
unsigned long xid;
|
|
struct sockaddr_in client_addr;
|
|
xdrproc_t xdrfunc;
|
|
char *result;
|
|
|
|
/*
|
|
* Set up correct reply struct and
|
|
* XDR filter depending on ypvers.
|
|
*/
|
|
switch (q->ypvers) {
|
|
case YPVERS:
|
|
bzero((char *)&result_v2, sizeof(result_v2));
|
|
|
|
if (buf == NULL)
|
|
result_v2.stat = YP_NOKEY;
|
|
else {
|
|
result_v2.val.valdat_len = strlen(buf);
|
|
result_v2.val.valdat_val = buf;
|
|
result_v2.stat = YP_TRUE;
|
|
}
|
|
result = (char *)&result_v2;
|
|
xdrfunc = (xdrproc_t)xdr_ypresp_val;
|
|
break;
|
|
case YPOLDVERS:
|
|
/*
|
|
* The odds are we will _never_ execute this
|
|
* particular code, but we include it anyway
|
|
* for the sake of completeness.
|
|
*/
|
|
bzero((char *)&result_v1, sizeof(result_v1));
|
|
result_v1.yp_resptype = YPRESP_VAL;
|
|
|
|
#define YPVAL ypresponse_u.yp_resp_valtype
|
|
if (buf == NULL)
|
|
result_v1.YPVAL.stat = YP_NOKEY;
|
|
else {
|
|
result_v1.YPVAL.val.valdat_len = strlen(buf);
|
|
result_v1.YPVAL.val.valdat_val = buf;
|
|
result_v1.YPVAL.stat = YP_TRUE;
|
|
}
|
|
result = (char *)&result_v1;
|
|
xdrfunc = (xdrproc_t)xdr_ypresponse;
|
|
break;
|
|
default:
|
|
yp_error("bad YP program version (%lu)!", q->ypvers);
|
|
return;
|
|
break;
|
|
}
|
|
|
|
if (debug)
|
|
yp_error("sending dns reply to %s (%lu)",
|
|
inet_ntoa(q->client_addr.sin_addr), q->id);
|
|
/*
|
|
* XXX This is disgusting. There's basically one transport
|
|
* handle for UDP, but we're holding off on replying to a
|
|
* client until we're ready, by which time we may have received
|
|
* several other queries from other clients with different
|
|
* transaction IDs. So to make the delayed response thing work,
|
|
* we have to save the transaction ID and client address of
|
|
* each request, then jam them into the transport handle when
|
|
* we're ready to send a reply. Then after we've send the reply,
|
|
* we put the old transaction ID and remote address back the
|
|
* way we found 'em. This is _INCREDIBLY_ non-portable; it's
|
|
* not even supported by the RPC library.
|
|
*/
|
|
/*
|
|
* XXX Don't frob the transaction ID for TCP handles.
|
|
*/
|
|
if (q->prot_type == SOCK_DGRAM)
|
|
xid = svcudp_set_xid(q->xprt, q->xid);
|
|
client_addr = q->xprt->xp_raddr;
|
|
q->xprt->xp_raddr = q->client_addr;
|
|
|
|
if (!svc_sendreply(q->xprt, xdrfunc, result))
|
|
yp_error("svc_sendreply failed");
|
|
|
|
/*
|
|
* Now that we sent the reply,
|
|
* put the handle back the way it was.
|
|
*/
|
|
if (q->prot_type == SOCK_DGRAM)
|
|
svcudp_set_xid(q->xprt, xid);
|
|
q->xprt->xp_raddr = client_addr;
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Decrement TTL on all queue entries, possibly nuking
|
|
* any that have been around too long without being serviced.
|
|
*/
|
|
void
|
|
yp_prune_dnsq(void)
|
|
{
|
|
register struct circleq_dnsentry *q, *n;
|
|
|
|
q = TAILQ_FIRST(&qhead);
|
|
while (q != NULL) {
|
|
q->ttl--;
|
|
n = TAILQ_NEXT(q, links);
|
|
if (!q->ttl) {
|
|
TAILQ_REMOVE(&qhead, q, links);
|
|
free(q->name);
|
|
free(q);
|
|
pending--;
|
|
}
|
|
q = n;
|
|
}
|
|
|
|
if (pending < 0)
|
|
pending = 0;
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Data is pending on the DNS socket; check for valid replies
|
|
* to our queries and dispatch them to waiting clients.
|
|
*/
|
|
void
|
|
yp_run_dnsq(void)
|
|
{
|
|
register struct circleq_dnsentry *q;
|
|
char buf[sizeof(HEADER) + MAXPACKET];
|
|
char retrybuf[MAXHOSTNAMELEN];
|
|
struct sockaddr_in sin;
|
|
int rval;
|
|
int len;
|
|
HEADER *hptr;
|
|
struct hostent *hent;
|
|
|
|
if (debug)
|
|
yp_error("running dns queue");
|
|
|
|
bzero(buf, sizeof(buf));
|
|
|
|
len = sizeof(struct sockaddr_in);
|
|
rval = recvfrom(resfd, buf, sizeof(buf), 0,
|
|
(struct sockaddr *)&sin, &len);
|
|
|
|
if (rval == -1) {
|
|
yp_error("recvfrom failed: %s", strerror(errno));
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* We may have data left in the socket that represents
|
|
* replies to earlier queries that we don't care about
|
|
* anymore. If there are no lookups pending or the packet
|
|
* ID doesn't match any of the queue IDs, just drop it
|
|
* on the floor.
|
|
*/
|
|
hptr = (HEADER *)&buf;
|
|
if (!pending ||
|
|
(q = yp_find_dnsqent(ntohs(hptr->id), BY_DNS_ID)) == NULL) {
|
|
/* ignore */
|
|
return;
|
|
}
|
|
|
|
if (debug)
|
|
yp_error("got dns reply from %s", inet_ntoa(sin.sin_addr));
|
|
|
|
hent = __dns_getanswer(buf, rval, q->name, q->type);
|
|
|
|
if (hent != NULL) {
|
|
if (q->type == T_PTR) {
|
|
hent->h_addr = (char *)&q->addr.s_addr;
|
|
hent->h_length = sizeof(struct in_addr);
|
|
}
|
|
}
|
|
|
|
/* Got an answer ready for a client -- send it off. */
|
|
yp_send_dns_reply(q, parse(hent));
|
|
pending--;
|
|
TAILQ_REMOVE(&qhead, q, links);
|
|
free(q->name);
|
|
free(q);
|
|
|
|
/* Decrement TTLs on other entries while we're here. */
|
|
yp_prune_dnsq();
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Queue and transmit an asynchronous DNS hostname lookup.
|
|
*/
|
|
ypstat
|
|
yp_async_lookup_name(struct svc_req *rqstp, char *name)
|
|
{
|
|
register struct circleq_dnsentry *q;
|
|
int type, len;
|
|
|
|
/* Check for SOCK_DGRAM or SOCK_STREAM -- we need to know later */
|
|
type = -1; len = sizeof(type);
|
|
if (getsockopt(rqstp->rq_xprt->xp_fd, SOL_SOCKET,
|
|
SO_TYPE, &type, &len) == -1) {
|
|
yp_error("getsockopt failed: %s", strerror(errno));
|
|
return(YP_YPERR);
|
|
}
|
|
|
|
/* Avoid transmitting dupe requests. */
|
|
if (type == SOCK_DGRAM &&
|
|
yp_find_dnsqent(svcudp_get_xid(rqstp->rq_xprt),BY_RPC_XID) != NULL)
|
|
return(YP_TRUE);
|
|
|
|
if ((q = yp_malloc_dnsent()) == NULL)
|
|
return(YP_YPERR);
|
|
|
|
q->type = T_A;
|
|
q->ttl = DEF_TTL;
|
|
q->xprt = rqstp->rq_xprt;
|
|
q->ypvers = rqstp->rq_vers;
|
|
q->prot_type = type;
|
|
if (q->prot_type == SOCK_DGRAM)
|
|
q->xid = svcudp_get_xid(q->xprt);
|
|
q->client_addr = q->xprt->xp_raddr;
|
|
q->domain = _res.dnsrch;
|
|
q->id = yp_send_dns_query(name, q->type);
|
|
|
|
if (q->id == 0) {
|
|
yp_error("DNS query failed");
|
|
free(q);
|
|
return(YP_YPERR);
|
|
}
|
|
|
|
q->name = strdup(name);
|
|
TAILQ_INSERT_HEAD(&qhead, q, links);
|
|
pending++;
|
|
|
|
if (debug)
|
|
yp_error("queueing async DNS name lookup (%d)", q->id);
|
|
|
|
yp_prune_dnsq();
|
|
return(YP_TRUE);
|
|
}
|
|
|
|
/*
|
|
* Queue and transmit an asynchronous DNS IP address lookup.
|
|
*/
|
|
ypstat
|
|
yp_async_lookup_addr(struct svc_req *rqstp, char *addr)
|
|
{
|
|
register struct circleq_dnsentry *q;
|
|
char buf[MAXHOSTNAMELEN];
|
|
int a, b, c, d;
|
|
int type, len;
|
|
|
|
/* Check for SOCK_DGRAM or SOCK_STREAM -- we need to know later */
|
|
type = -1; len = sizeof(type);
|
|
if (getsockopt(rqstp->rq_xprt->xp_fd, SOL_SOCKET,
|
|
SO_TYPE, &type, &len) == -1) {
|
|
yp_error("getsockopt failed: %s", strerror(errno));
|
|
return(YP_YPERR);
|
|
}
|
|
|
|
/* Avoid transmitting dupe requests. */
|
|
if (type == SOCK_DGRAM &&
|
|
yp_find_dnsqent(svcudp_get_xid(rqstp->rq_xprt),BY_RPC_XID) != NULL)
|
|
return(YP_TRUE);
|
|
|
|
if ((q = yp_malloc_dnsent()) == NULL)
|
|
return(YP_YPERR);
|
|
|
|
if (sscanf(addr, "%d.%d.%d.%d", &a, &b, &c, &d) != 4)
|
|
return(YP_NOKEY);
|
|
|
|
snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa", d, c, b, a);
|
|
|
|
if (debug)
|
|
yp_error("DNS address is: %s", buf);
|
|
|
|
q->type = T_PTR;
|
|
q->ttl = DEF_TTL;
|
|
q->xprt = rqstp->rq_xprt;
|
|
q->ypvers = rqstp->rq_vers;
|
|
q->domain = NULL;
|
|
q->prot_type = type;
|
|
if (q->prot_type == SOCK_DGRAM)
|
|
q->xid = svcudp_get_xid(q->xprt);
|
|
q->client_addr = q->xprt->xp_raddr;
|
|
q->id = yp_send_dns_query(buf, q->type);
|
|
|
|
if (q->id == 0) {
|
|
yp_error("DNS query failed");
|
|
free(q);
|
|
return(YP_YPERR);
|
|
}
|
|
|
|
inet_aton(addr, &q->addr);
|
|
q->name = strdup(buf);
|
|
TAILQ_INSERT_HEAD(&qhead, q, links);
|
|
pending++;
|
|
|
|
if (debug)
|
|
yp_error("queueing async DNS address lookup (%d)", q->id);
|
|
|
|
yp_prune_dnsq();
|
|
return(YP_TRUE);
|
|
}
|