freebsd-dev/libexec/ypxfr/ypxfr_main.c
Bill Paul 23677e98fe Putting records with zero-length keys into a Berkeley DB hash database
is asking for trouble (sequential database enumerations can get caught
in an infinite loop). The yp_mkdb(8) utility avoids putting such records
into a database, but ypxfr does not. Today I got bit by a NULL entry in
one of the amd maps on my network, which is served by a SunOS master.
The map was transfered successfully to my FreeBSD slave, but attempting
to dump it with ypcat(1) caused ypserv(8) to transmit the same record
over and over again, making the map appear to be infinitely large. I
finally noticed the problem while testing a new version of amd under
development at the Columbia CS department, which began gobbling up insane
amounts of memory while trying to swallow the map.

To deal with this problem, I'm modifying ypxfr to watch for records
with zero-length keys and turn them into something less destructive
before writing them to the database.
1997-09-30 18:08:11 +00:00

584 lines
16 KiB
C

/*
* Copyright (c) 1995
* 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 author nor the names of any co-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.
*
* $Id: ypxfr_main.c,v 1.9 1997/03/28 15:48:21 imp Exp $
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <syslog.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <rpc/rpc.h>
#include <rpc/clnt.h>
#include <rpcsvc/yp.h>
struct dom_binding {};
#include <rpcsvc/ypclnt.h>
#include <rpcsvc/ypxfrd.h>
#include "ypxfr_extern.h"
#ifndef lint
static const char rcsid[] = "$Id: ypxfr_main.c,v 1.9 1997/03/28 15:48:21 imp Exp $";
#endif
char *progname = "ypxfr";
char *yp_dir = _PATH_YP;
int _rpcpmstart = 0;
int ypxfr_use_yplib = 0; /* Assume the worst. */
int ypxfr_clear = 1;
int ypxfr_prognum = 0;
struct sockaddr_in ypxfr_callback_addr;
struct yppushresp_xfr ypxfr_resp;
DB *dbp;
static void ypxfr_exit(retval, temp)
ypxfrstat retval;
char *temp;
{
CLIENT *clnt;
int sock = RPC_ANYSOCK;
struct timeval timeout;
/* Clean up no matter what happened previously. */
if (temp != NULL) {
if (dbp != NULL)
(void)(dbp->close)(dbp);
if (unlink(temp) == -1) {
yp_error("failed to unlink %s",strerror(errno));
}
}
if (_rpcpmstart) {
timeout.tv_sec = 20;
timeout.tv_usec = 0;
if ((clnt = clntudp_create(&ypxfr_callback_addr, ypxfr_prognum,
1, timeout, &sock)) == NULL) {
yp_error("%s", clnt_spcreateerror("failed to \
establish callback handle"));
exit(1);
}
ypxfr_resp.status = retval;
if (yppushproc_xfrresp_1(&ypxfr_resp, clnt) == NULL) {
yp_error("%s", clnt_sperror(clnt, "callback failed"));
clnt_destroy(clnt);
exit(1);
}
clnt_destroy(clnt);
} else {
yp_error("Exiting: %s", ypxfrerr_string(retval));
}
exit(0);
}
static void usage()
{
if (_rpcpmstart) {
ypxfr_exit(YPXFR_BADARGS,NULL);
} else {
fprintf(stderr,"usage: %s [-f] [-c] [-d target domain] \
[-h source host] [-s source domain]\n", progname);
fprintf(stderr,"\t [-p path] [-C taskid program-number \
ipaddr port] mapname\n");
exit(1);
}
}
int ypxfr_foreach(status, key, keylen, val, vallen, data)
int status;
char *key;
int keylen;
char *val;
int vallen;
char *data;
{
DBT dbkey, dbval;
if (status != YP_TRUE)
return (status);
/*
* XXX Do not attempt to write zero-length keys or
* data into a Berkeley DB hash database. It causes a
* strange failure mode where sequential searches get
* caught in an infinite loop.
*/
if (keylen) {
dbkey.data = key;
dbkey.size = keylen;
} else {
dbkey.data = "";
dbkey.size = 1;
}
if (vallen) {
dbval.data = val;
dbval.size = vallen;
} else {
dbval.data = "";
dbval.size = 1;
}
if (yp_put_record(dbp, &dbkey, &dbval, 0) != YP_TRUE)
return(yp_errno);
return (0);
}
main(argc,argv)
int argc;
char *argv[];
{
int ch;
int ypxfr_force = 0;
char *ypxfr_dest_domain = NULL;
char *ypxfr_source_host = NULL;
char *ypxfr_source_domain = NULL;
char *ypxfr_local_domain = NULL;
char *ypxfr_master = NULL;
unsigned long ypxfr_order = -1, ypxfr_skew_check = -1;
char *ypxfr_mapname = NULL;
int ypxfr_args = 0;
char ypxfr_temp_map[MAXPATHLEN + 2];
char tempmap[MAXPATHLEN + 2];
char buf[MAXPATHLEN + 2];
DBT key, data;
int remoteport;
int interdom = 0;
int secure = 0;
debug = 1;
if (!isatty(fileno(stderr))) {
openlog(progname, LOG_PID, LOG_DAEMON);
_rpcpmstart = 1;
}
if (argc < 2)
usage();
while ((ch = getopt(argc, argv, "fcd:h:s:p:C:")) != -1) {
int my_optind;
switch(ch) {
case 'f':
ypxfr_force++;
ypxfr_args++;
break;
case 'c':
ypxfr_clear = 0;
ypxfr_args++;
break;
case 'd':
ypxfr_dest_domain = optarg;
ypxfr_args += 2;
break;
case 'h':
ypxfr_source_host = optarg;
ypxfr_args += 2;
break;
case 's':
ypxfr_source_domain = optarg;
ypxfr_args += 2;
break;
case 'p':
yp_dir = optarg;
ypxfr_args += 2;
break;
case 'C':
/*
* Whoever decided that the -C flag should take
* four arguments is a twit.
*/
my_optind = optind - 1;
if (argv[my_optind] == NULL || !strlen(argv[my_optind])) {
yp_error("transaction ID not specified");
usage();
}
ypxfr_resp.transid = atol(argv[my_optind]);
my_optind++;
if (argv[my_optind] == NULL || !strlen(argv[my_optind])) {
yp_error("RPC program number not specified");
usage();
}
ypxfr_prognum = atol(argv[my_optind]);
my_optind++;
if (argv[my_optind] == NULL || !strlen(argv[my_optind])) {
yp_error("address not specified");
usage();
}
if (!inet_aton(argv[my_optind], &ypxfr_callback_addr.sin_addr)) {
yp_error("failed to convert '%s' to IP addr",
argv[my_optind]);
exit(1);
}
my_optind++;
if (argv[my_optind] == NULL || !strlen(argv[my_optind])) {
yp_error("port not specified");
usage();
}
ypxfr_callback_addr.sin_port = htons((u_short)atoi(argv[my_optind]));
ypxfr_args += 5;
break;
default:
usage();
break;
}
}
ypxfr_mapname = argv[ypxfr_args + 1];
if (ypxfr_mapname == NULL) {
yp_error("no map name specified");
usage();
}
/* Always the case. */
ypxfr_callback_addr.sin_family = AF_INET;
/* Determine if local NIS client facilities are turned on. */
if (!yp_get_default_domain(&ypxfr_local_domain) &&
_yp_check(&ypxfr_local_domain))
ypxfr_use_yplib = 1;
/*
* If no destination domain is specified, assume that the
* local default domain is to be used and try to obtain it.
* Fails if NIS client facilities are turned off.
*/
if (ypxfr_dest_domain == NULL) {
if (ypxfr_use_yplib) {
yp_get_default_domain(&ypxfr_dest_domain);
} else {
yp_error("no destination domain specified and \
the local domain name isn't set");
ypxfr_exit(YPXFR_BADARGS,NULL);
}
}
/*
* If a source domain is not specified, assume it to
* be the same as the destination domain.
*/
if (ypxfr_source_domain == NULL) {
ypxfr_source_domain = ypxfr_dest_domain;
}
/*
* If the source host is not specified, assume it to be the
* master for the specified map. If local NIS client facilities
* are turned on, we can figure this out using yp_master().
* If not, we have to see if a local copy of the map exists
* and extract its YP_MASTER_NAME record. If _that_ fails,
* we are stuck and must ask the user for more information.
*/
if (ypxfr_source_host == NULL) {
if (!ypxfr_use_yplib) {
/*
* Double whammy: NIS isn't turned on and the user
* didn't specify a source host.
*/
char *dptr;
key.data = "YP_MASTER_NAME";
key.size = sizeof("YP_MASTER_NAME") - 1;
if (yp_get_record(ypxfr_dest_domain, ypxfr_mapname,
&key, &data, 1) != YP_TRUE) {
yp_error("no source host specified");
ypxfr_exit(YPXFR_BADARGS,NULL);
}
dptr = data.data;
dptr[data.size] = '\0';
ypxfr_master = ypxfr_source_host = strdup(dptr);
}
} else {
if (ypxfr_use_yplib)
ypxfr_use_yplib = 0;
}
if (ypxfr_master == NULL) {
if ((ypxfr_master = ypxfr_get_master(ypxfr_source_domain,
ypxfr_mapname,
ypxfr_source_host,
ypxfr_use_yplib)) == NULL) {
yp_error("failed to find master of %s in domain %s: %s",
ypxfr_mapname, ypxfr_source_domain,
ypxfrerr_string(yp_errno));
ypxfr_exit(YPXFR_MADDR,NULL);
}
}
/*
* If we got here and ypxfr_source_host is still undefined,
* it means we had to resort to using yp_master() to find the
* master server for the map. The source host and master should
* be identical.
*/
if (ypxfr_source_host == NULL)
ypxfr_source_host = ypxfr_master;
/*
* Don't talk to ypservs on unprivileged ports.
*/
remoteport = getrpcport(ypxfr_source_host, YPPROG, YPVERS, IPPROTO_UDP);
if (remoteport >= IPPORT_RESERVED) {
yp_error("ypserv on %s not running on reserved port",
ypxfr_source_host);
ypxfr_exit(YPXFR_REFUSED, NULL);
}
if ((ypxfr_order = ypxfr_get_order(ypxfr_source_domain,
ypxfr_mapname,
ypxfr_master, 0)) == 0) {
yp_error("failed to get order number of %s: %s",
ypxfr_mapname, yp_errno == YPXFR_SUCC ?
"map has order 0" : ypxfrerr_string(yp_errno));
ypxfr_exit(YPXFR_YPERR,NULL);
}
if (ypxfr_match(ypxfr_master, ypxfr_source_domain, ypxfr_mapname,
"YP_INTERDOMAIN", sizeof("YP_INTERDOMAIN") - 1))
interdom++;
if (ypxfr_match(ypxfr_master, ypxfr_source_domain, ypxfr_mapname,
"YP_SECURE", sizeof("YP_SECURE") - 1))
secure++;
key.data = "YP_LAST_MODIFIED";
key.size = sizeof("YP_LAST_MODIFIED") - 1;
/* The order number is immaterial when the 'force' flag is set. */
if (!ypxfr_force) {
int ignore = 0;
if (yp_get_record(ypxfr_dest_domain,ypxfr_mapname,&key,&data,1) != YP_TRUE) {
switch(yp_errno) {
case YP_NOKEY:
ypxfr_exit(YPXFR_FORCE,NULL);
break;
case YP_NOMAP:
/*
* If the map doesn't exist, we're
* creating it. Ignore the error.
*/
ignore++;
break;
case YP_BADDB:
default:
ypxfr_exit(YPXFR_DBM,NULL);
break;
}
}
if (!ignore && ypxfr_order <= atoi(data.data))
ypxfr_exit(YPXFR_AGE, NULL);
}
/* Construct a temporary map file name */
snprintf(tempmap, sizeof(tempmap), "%s.%d",ypxfr_mapname, getpid());
snprintf(ypxfr_temp_map, sizeof(ypxfr_temp_map), "%s/%s/%s", yp_dir,
ypxfr_dest_domain, tempmap);
if ((remoteport = getrpcport(ypxfr_source_host, YPXFRD_FREEBSD_PROG,
YPXFRD_FREEBSD_VERS, IPPROTO_TCP))) {
/* Don't talk to rpc.ypxfrds on unprovileged ports. */
if (remoteport >= IPPORT_RESERVED) {
yp_error("rpc.ypxfrd on %s not using privileged port",
ypxfr_source_host);
ypxfr_exit(YPXFR_REFUSED, NULL);
}
/* Try to send using ypxfrd. If it fails, use old method. */
if (!ypxfrd_get_map(ypxfr_source_host, ypxfr_mapname,
ypxfr_source_domain, ypxfr_temp_map))
goto leave;
}
/* Open the temporary map read/write. */
if ((dbp = yp_open_db_rw(ypxfr_dest_domain, tempmap, 0)) == NULL) {
yp_error("failed to open temporary map file");
ypxfr_exit(YPXFR_DBM,NULL);
}
/*
* Fill in the keys we already know, such as the order number,
* master name, input file name (we actually make up a bogus
* name for that) and output file name.
*/
snprintf(buf, sizeof(buf), "%d", ypxfr_order);
data.data = buf;
data.size = strlen(buf);
if (yp_put_record(dbp, &key, &data, 0) != YP_TRUE) {
yp_error("failed to write order number to database");
ypxfr_exit(YPXFR_DBM,&ypxfr_temp_map);
}
key.data = "YP_MASTER_NAME";
key.size = sizeof("YP_MASTER_NAME") - 1;
data.data = ypxfr_master;
data.size = strlen(ypxfr_master);
if (yp_put_record(dbp, &key, &data, 0) != YP_TRUE) {
yp_error("failed to write master name to database");
ypxfr_exit(YPXFR_DBM,&ypxfr_temp_map);
}
key.data = "YP_DOMAIN_NAME";
key.size = sizeof("YP_DOMAIN_NAME") - 1;
data.data = ypxfr_dest_domain;
data.size = strlen(ypxfr_dest_domain);
if (yp_put_record(dbp, &key, &data, 0) != YP_TRUE) {
yp_error("failed to write domain name to database");
ypxfr_exit(YPXFR_DBM,&ypxfr_temp_map);
}
snprintf (buf, sizeof(buf), "%s:%s", ypxfr_source_host, ypxfr_mapname);
key.data = "YP_INPUT_NAME";
key.size = sizeof("YP_INPUT_NAME") - 1;
data.data = &buf;
data.size = strlen(buf);
if (yp_put_record(dbp, &key, &data, 0) != YP_TRUE) {
yp_error("failed to write input name to database");
ypxfr_exit(YPXFR_DBM,&ypxfr_temp_map);
}
snprintf(buf, sizeof(buf), "%s/%s/%s", yp_dir, ypxfr_dest_domain,
ypxfr_mapname);
key.data = "YP_OUTPUT_NAME";
key.size = sizeof("YP_OUTPUT_NAME") - 1;
data.data = &buf;
data.size = strlen(buf);
if (yp_put_record(dbp, &key, &data, 0) != YP_TRUE) {
yp_error("failed to write output name to database");
ypxfr_exit(YPXFR_DBM,&ypxfr_temp_map);
}
if (interdom) {
key.data = "YP_INTERDOMAIN";
key.size = sizeof("YP_INTERDOMAIN") - 1;
data.data = "";
data.size = 0;
if (yp_put_record(dbp, &key, &data, 0) != YP_TRUE) {
yp_error("failed to add interdomain flag to database");
ypxfr_exit(YPXFR_DBM,&ypxfr_temp_map);
}
}
if (secure) {
key.data = "YP_SECURE";
key.size = sizeof("YP_SECURE") - 1;
data.data = "";
data.size = 0;
if (yp_put_record(dbp, &key, &data, 0) != YP_TRUE) {
yp_error("failed to add secure flag to database");
ypxfr_exit(YPXFR_DBM,&ypxfr_temp_map);
}
}
/* Now suck over the contents of the map from the master. */
if (ypxfr_get_map(ypxfr_mapname,ypxfr_source_domain,
ypxfr_source_host, ypxfr_foreach)){
yp_error("failed to retrieve map from source host");
ypxfr_exit(YPXFR_YPERR,&ypxfr_temp_map);
}
(void)(dbp->close)(dbp);
dbp = NULL; /* <- yes, it seems this is necessary. */
leave:
snprintf(buf, sizeof(buf), "%s/%s/%s", yp_dir, ypxfr_dest_domain,
ypxfr_mapname);
/* Peek at the order number again and check for skew. */
if ((ypxfr_skew_check = ypxfr_get_order(ypxfr_source_domain,
ypxfr_mapname,
ypxfr_master, 0)) == 0) {
yp_error("failed to get order number of %s: %s",
ypxfr_mapname, yp_errno == YPXFR_SUCC ?
"map has order 0" : ypxfrerr_string(yp_errno));
ypxfr_exit(YPXFR_YPERR,&ypxfr_temp_map);
}
if (ypxfr_order != ypxfr_skew_check)
ypxfr_exit(YPXFR_SKEW,&ypxfr_temp_map);
/*
* Send a YPPROC_CLEAR to the local ypserv.
*/
if (ypxfr_clear) {
char in = 0;
char *out = NULL;
int stat;
if ((stat = callrpc("localhost",YPPROG,YPVERS,YPPROC_CLEAR,
xdr_void, (void *)&in,
xdr_void, (void *)out)) != RPC_SUCCESS) {
yp_error("failed to send 'clear' to local ypserv: %s",
clnt_sperrno((enum clnt_stat) stat));
ypxfr_exit(YPXFR_CLEAR, &ypxfr_temp_map);
}
}
/*
* Put the new map in place immediately. I'm not sure if the
* kernel does an unlink() and rename() atomically in the event
* that we move a new copy of a map over the top of an existing
* one, but there's less chance of a race condition happening
* than if we were to do the unlink() ourselves.
*/
if (rename(ypxfr_temp_map, buf) == -1) {
yp_error("rename(%s,%s) failed: %s", ypxfr_temp_map, buf,
strerror(errno));
ypxfr_exit(YPXFR_FILE,NULL);
}
ypxfr_exit(YPXFR_SUCC,NULL);
return(1);
}