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/* $OpenBSD: yp_bind.c,v 1.28 2016/05/30 02:53:29 guenther Exp $ */
/*
* Copyright (c) 1992, 1993, 1996 Theo de Raadt <deraadt@theos.com>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <paths.h>
#include <rpc/rpc.h>
#include <rpc/xdr.h>
#include <rpcsvc/yp.h>
#include <rpcsvc/ypclnt.h>
#include "ypinternal.h"
struct dom_binding *_ypbindlist;
char _yp_domain[HOST_NAME_MAX+1];
int _yplib_timeout = 10;
int
_yp_dobind(const char *dom, struct dom_binding **ypdb)
{
static pid_t pid = -1;
char path[PATH_MAX];
struct dom_binding *ysd, *ysd2;
struct ypbind_resp ypbr;
struct timeval tv;
struct sockaddr_in clnt_sin;
struct ypbind_binding *bn;
int clnt_sock, fd;
pid_t gpid;
CLIENT *client;
int new = 0, r;
u_short port;
/*
* test if YP is running or not
*/
if ((fd = open(YPBINDLOCK, O_RDONLY)) == -1)
return YPERR_YPBIND;
if (!(flock(fd, LOCK_EX | LOCK_NB) == -1 && errno == EWOULDBLOCK)) {
(void)close(fd);
return YPERR_YPBIND;
}
(void)close(fd);
gpid = getpid();
if (!(pid == -1 || pid == gpid)) {
ysd = _ypbindlist;
while (ysd) {
if (ysd->dom_client)
clnt_destroy(ysd->dom_client);
ysd2 = ysd->dom_pnext;
free(ysd);
ysd = ysd2;
}
_ypbindlist = NULL;
}
pid = gpid;
if (ypdb != NULL)
*ypdb = NULL;
if (dom == NULL || strlen(dom) == 0)
return YPERR_BADARGS;
for (ysd = _ypbindlist; ysd; ysd = ysd->dom_pnext)
if (strcmp(dom, ysd->dom_domain) == 0)
break;
if (ysd == NULL) {
if ((ysd = calloc(1, sizeof *ysd)) == NULL)
return YPERR_RESRC;
ysd->dom_socket = -1;
ysd->dom_vers = 0;
new = 1;
}
again:
if (ysd->dom_vers == 0) {
r = snprintf(path, sizeof(path), "%s/%s.%d",
BINDINGDIR, dom, 2);
if (r < 0 || r >= sizeof(path)) {
if (new)
free(ysd);
return YPERR_BADARGS;
}
if ((fd = open(path, O_RDONLY)) == -1) {
/*
* no binding file, YP is dead, or not yet fully
* alive.
*/
goto trynet;
}
if (flock(fd, LOCK_EX | LOCK_NB) == -1 &&
errno == EWOULDBLOCK) {
struct iovec iov[2];
u_short ypb_port;
/*
* we fetch the ypbind port number, but do
* nothing with it.
*/
iov[0].iov_base = (caddr_t) &ypb_port;
iov[0].iov_len = sizeof ypb_port;
iov[1].iov_base = (caddr_t) &ypbr;
iov[1].iov_len = sizeof ypbr;
r = readv(fd, iov, 2);
if (r != iov[0].iov_len + iov[1].iov_len) {
(void)close(fd);
ysd->dom_vers = -1;
goto again;
}
(void)close(fd);
goto gotdata;
} else {
/* no lock on binding file, YP is dead. */
(void)close(fd);
if (new)
free(ysd);
return YPERR_YPBIND;
}
}
trynet:
if (ysd->dom_vers == -1 || ysd->dom_vers == 0) {
(void)memset(&clnt_sin, 0, sizeof clnt_sin);
clnt_sin.sin_len = sizeof(struct sockaddr_in);
clnt_sin.sin_family = AF_INET;
clnt_sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
clnt_sock = RPC_ANYSOCK;
client = clnttcp_create(&clnt_sin, YPBINDPROG, YPBINDVERS,
&clnt_sock, 0, 0);
if (client == NULL) {
clnt_pcreateerror("clnttcp_create");
if (new)
free(ysd);
switch (rpc_createerr.cf_error.re_errno) {
case ECONNREFUSED:
return YPERR_YPBIND;
case ENOMEM:
return YPERR_RESRC;
default:
return YPERR_YPERR;
}
}
if (ntohs(clnt_sin.sin_port) >= IPPORT_RESERVED ||
ntohs(clnt_sin.sin_port) == 20) {
/*
* YP was not running, but someone has registered
* ypbind with portmap -- this simply means YP is
* not running.
*/
clnt_destroy(client);
if (new)
free(ysd);
return YPERR_YPBIND;
}
tv.tv_sec = _yplib_timeout;
tv.tv_usec = 0;
r = clnt_call(client, YPBINDPROC_DOMAIN, xdr_domainname,
&dom, xdr_ypbind_resp, &ypbr, tv);
if (r != RPC_SUCCESS) {
clnt_destroy(client);
ysd->dom_vers = -1;
goto again;
}
clnt_destroy(client);
gotdata:
bn = &ypbr.ypbind_resp_u.ypbind_bindinfo;
memcpy(&port, &bn->ypbind_binding_port, sizeof port);
if (ntohs(port) >= IPPORT_RESERVED ||
ntohs(port) == 20) {
/*
* This is bullshit -- the ypbind wants me to
* communicate to an insecure ypserv. We are
* within rights to syslog this as an attack,
* but for now we'll simply ignore it; real YP
* is obviously not running.
*/
if (new)
free(ysd);
return YPERR_YPBIND;
}
(void)memset(&ysd->dom_server_addr, 0,
sizeof ysd->dom_server_addr);
ysd->dom_server_addr.sin_len = sizeof(struct sockaddr_in);
ysd->dom_server_addr.sin_family = AF_INET;
memcpy(&ysd->dom_server_addr.sin_port,
&bn->ypbind_binding_port,
sizeof(ysd->dom_server_addr.sin_port));
memcpy(&ysd->dom_server_addr.sin_addr.s_addr,
&bn->ypbind_binding_addr,
sizeof(ysd->dom_server_addr.sin_addr.s_addr));
ysd->dom_server_port = ysd->dom_server_addr.sin_port;
ysd->dom_vers = YPVERS;
strlcpy(ysd->dom_domain, dom, sizeof ysd->dom_domain);
}
tv.tv_sec = _yplib_timeout / 2;
tv.tv_usec = 0;
if (ysd->dom_client)
clnt_destroy(ysd->dom_client);
ysd->dom_socket = RPC_ANYSOCK;
ysd->dom_client = clntudp_create(&ysd->dom_server_addr,
YPPROG, YPVERS, tv, &ysd->dom_socket);
if (ysd->dom_client == NULL) {
clnt_pcreateerror("clntudp_create");
ysd->dom_vers = -1;
goto again;
}
if (fcntl(ysd->dom_socket, F_SETFD, FD_CLOEXEC) == -1)
perror("fcntl: F_SETFD");
if (new) {
ysd->dom_pnext = _ypbindlist;
_ypbindlist = ysd;
}
if (ypdb != NULL)
*ypdb = ysd;
return 0;
}
void
_yp_unbind(struct dom_binding *ypb)
{
clnt_destroy(ypb->dom_client);
ypb->dom_client = NULL;
ypb->dom_socket = -1;
}
int
yp_bind(const char *dom)
{
return _yp_dobind(dom, NULL);
}
DEF_WEAK(yp_bind);
void
yp_unbind(const char *dom)
{
struct dom_binding *ypb, *ypbp;
ypbp = NULL;
for (ypb = _ypbindlist; ypb; ypb = ypb->dom_pnext) {
if (strcmp(dom, ypb->dom_domain) == 0) {
clnt_destroy(ypb->dom_client);
if (ypbp)
ypbp->dom_pnext = ypb->dom_pnext;
else
_ypbindlist = ypb->dom_pnext;
free(ypb);
return;
}
ypbp = ypb;
}
}
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