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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* warmstart.c
* Allows for gathering of registrations from a earlier dumped file.
*
* Copyright 1990,2002-2003 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright 2013 Nexenta Systems, Inc. All rights reserved.
*/
#include <stdio.h>
#include <errno.h>
#include <rpc/rpc.h>
#include <rpc/rpcb_prot.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef PORTMAP
#include <netinet/in.h>
#include <rpc/pmap_prot.h>
#endif
#include "rpcbind.h"
#include <syslog.h>
#include <unistd.h>
#include <rpcsvc/daemon_utils.h>
#include <assert.h>
/* These files keep the pmap_list and rpcb_list in XDR format */
static const char rpcbfile[] = DAEMON_DIR "/rpcbind.file";
#ifdef PORTMAP
static const char pmapfile[] = DAEMON_DIR "/portmap.file";
#endif
static FILE *
open_tmp_file(const char *filename)
{
int fd;
FILE *fp;
/*
* Remove any existing files, and create a new one.
* Ensure that rpcbind is not forced to overwrite
* a file pointed to by a symbolic link created
* by an attacker.
* Use open O_CREAT|O_EXCL so file is not created
* between unlink() and open() operation.
*/
if (unlink(filename) == -1) {
if (errno != ENOENT)
return (NULL);
}
fd = open(filename, O_CREAT|O_EXCL|O_WRONLY, 0600);
if (fd == -1)
return (NULL);
fp = fdopen(fd, "w");
if (fp == NULL) {
close(fd);
return (NULL);
}
return (fp);
}
static bool_t
write_struct(const char *filename, xdrproc_t structproc, void *list)
{
FILE *fp;
XDR xdrs;
fp = open_tmp_file(filename);
if (fp == NULL) {
int i;
for (i = 0; i < 10; i++)
close(i);
fp = open_tmp_file(filename);
if (fp == NULL) {
syslog(LOG_ERR,
"cannot open file = %s for writing", filename);
syslog(LOG_ERR, "cannot save any registration");
return (FALSE);
}
}
xdrstdio_create(&xdrs, fp, XDR_ENCODE);
if (structproc(&xdrs, list) == FALSE) {
XDR_DESTROY(&xdrs);
syslog(LOG_ERR, "rpcbind: xdr_%s: failed", filename);
fclose(fp);
return (FALSE);
}
XDR_DESTROY(&xdrs);
fclose(fp);
return (TRUE);
}
static bool_t
read_struct(const char *filename, xdrproc_t structproc, void *list)
{
int fd;
FILE *fp = NULL;
XDR xdrs;
struct stat sbuf_fstat, sbuf_lstat;
fd = open(filename, O_RDONLY, 0600);
if (fd == -1) {
fprintf(stderr,
"rpcbind: cannot open file = %s for reading\n", filename);
goto error;
}
fp = fdopen(fd, "r");
if (fp == NULL) {
close(fd);
fprintf(stderr,
"rpcbind: cannot open file = %s for reading\n", filename);
goto error;
}
if (fstat(fd, &sbuf_fstat) != 0) {
fprintf(stderr,
"rpcbind: cannot stat file = %s for reading\n", filename);
goto error;
}
if (sbuf_fstat.st_uid != DAEMON_UID ||
(!S_ISREG(sbuf_fstat.st_mode)) ||
(sbuf_fstat.st_mode & S_IRWXG) ||
(sbuf_fstat.st_mode & S_IRWXO) ||
(sbuf_fstat.st_nlink != 1)) {
fprintf(stderr, "rpcbind: invalid permissions on file = %s for "
"reading\n", filename);
goto error;
}
/*
* Make sure that the pathname for fstat and lstat is the same and
* that it's not a link. An attacker can create symbolic or
* hard links and use them to gain unauthorised access to the
* system when rpcbind aborts or terminates on SIGINT or SIGTERM.
*/
if (lstat(filename, &sbuf_lstat) != 0) {
fprintf(stderr,
"rpcbind: cannot lstat file = %s for reading\n", filename);
goto error;
}
if (sbuf_lstat.st_uid != DAEMON_UID ||
(!S_ISREG(sbuf_lstat.st_mode)) ||
(sbuf_lstat.st_mode & S_IRWXG) ||
(sbuf_lstat.st_mode & S_IRWXO) ||
(sbuf_lstat.st_nlink != 1) ||
(sbuf_fstat.st_dev != sbuf_lstat.st_dev) ||
(sbuf_fstat.st_ino != sbuf_lstat.st_ino)) {
fprintf(stderr, "rpcbind: invalid lstat permissions on file = "
"%s for reading\n", filename);
goto error;
}
xdrstdio_create(&xdrs, fp, XDR_DECODE);
if (structproc(&xdrs, list) == FALSE) {
XDR_DESTROY(&xdrs);
fprintf(stderr, "rpcbind: xdr_%s: failed\n", filename);
goto error;
}
XDR_DESTROY(&xdrs);
fclose(fp);
return (TRUE);
error:
fprintf(stderr, "rpcbind: will start from scratch\n");
if (fp != NULL)
fclose(fp);
return (FALSE);
}
void
write_warmstart(void)
{
assert(RW_WRITE_HELD(&list_rbl_lock));
(void) write_struct(rpcbfile, xdr_rpcblist_ptr, &list_rbl);
#ifdef PORTMAP
assert(RW_WRITE_HELD(&list_pml_lock));
(void) write_struct(pmapfile, xdr_pmaplist_ptr, &list_pml);
#endif
}
void
read_warmstart(void)
{
rpcblist_ptr tmp_rpcbl = NULL;
#ifdef PORTMAP
pmaplist_ptr tmp_pmapl = NULL;
#endif
if (read_struct(rpcbfile, xdr_rpcblist_ptr, &tmp_rpcbl) == FALSE)
return;
#ifdef PORTMAP
if (read_struct(pmapfile, xdr_pmaplist_ptr, &tmp_pmapl) == FALSE) {
xdr_free((xdrproc_t)xdr_rpcblist_ptr, (char *)&tmp_rpcbl);
return;
}
#endif
xdr_free((xdrproc_t)xdr_rpcblist_ptr, (char *)&list_rbl);
list_rbl = tmp_rpcbl;
#ifdef PORTMAP
xdr_free((xdrproc_t)xdr_pmaplist_ptr, (char *)&list_pml);
list_pml = (pmaplist *)tmp_pmapl;
#endif
}
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