freebsd-dev/usr.sbin/mount_portalfs/activate.c
David Malone 2bc21ed985 Hopefully improve control message passing over Unix domain sockets.
1) Allow the sending of more than one control message at a time
over a unix domain socket. This should cover the PR 29499.

2) This requires that unp_{ex,in}ternalize and unp_scan understand
mbufs with more than one control message at a time.

3) Internalize and externalize used to work on the mbuf in-place.
This made life quite complicated and the code for sizeof(int) <
sizeof(file *) could end up doing the wrong thing. The patch always
create a new mbuf/cluster now. This resulted in the change of the
prototype for the domain externalise function.

4) You can now send SCM_TIMESTAMP messages.

5) Always use CMSG_DATA(cm) to determine the start where the data
in unp_{ex,in}ternalize. It was using ((struct cmsghdr *)cm + 1)
in some places, which gives the wrong alignment on the alpha.
(NetBSD made this fix some time ago).

This results in an ABI change for discriptor passing and creds
passing on the alpha. (Probably on the IA64 and Spare ports too).

6) Fix userland programs to use CMSG_* macros too.

7) Be more careful about freeing mbufs containing (file *)s.
This is made possible by the prototype change of externalise.

PR:		29499
MFC after:	6 weeks
2001-10-04 13:11:48 +00:00

215 lines
5.0 KiB
C

/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
* All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* 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.
*
* @(#)activate.c 8.3 (Berkeley) 4/28/95
*/
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <sys/uio.h>
#include "portald.h"
/*
* Scan the providers list and call the
* appropriate function.
*/
static int activate_argv(pcr, key, v, so, fdp)
struct portal_cred *pcr;
char *key;
char **v;
int so;
int *fdp;
{
provider *pr;
for (pr = providers; pr->pr_match; pr++)
if (strcmp(v[0], pr->pr_match) == 0)
return ((*pr->pr_func)(pcr, key, v, so, fdp));
return (ENOENT);
}
static int get_request(so, pcr, key, klen)
int so;
struct portal_cred *pcr;
char *key;
int klen;
{
struct iovec iov[2];
struct msghdr msg;
int n;
iov[0].iov_base = (caddr_t) pcr;
iov[0].iov_len = sizeof(*pcr);
iov[1].iov_base = key;
iov[1].iov_len = klen;
memset(&msg, 0, sizeof(msg));
msg.msg_iov = iov;
msg.msg_iovlen = 2;
n = recvmsg(so, &msg, 0);
if (n < 0)
return (errno);
if (n <= sizeof(*pcr))
return (EINVAL);
n -= sizeof(*pcr);
key[n] = '\0';
return (0);
}
static void send_reply(so, fd, error)
int so;
int fd;
int error;
{
int n;
struct iovec iov;
struct msghdr msg;
union {
struct cmsghdr cmsg;
char control[CMSG_SPACE(sizeof(int))];
} ctl;
/*
* Line up error code. Don't worry about byte ordering
* because we must be sending to the local machine.
*/
iov.iov_base = (caddr_t) &error;
iov.iov_len = sizeof(error);
/*
* Build a msghdr
*/
memset(&msg, 0, sizeof(msg));
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
/*
* If there is a file descriptor to send then
* construct a suitable rights control message.
*/
if (fd >= 0) {
ctl.cmsg.cmsg_len = CMSG_LEN(sizeof(int));
ctl.cmsg.cmsg_level = SOL_SOCKET;
ctl.cmsg.cmsg_type = SCM_RIGHTS;
*((int *)CMSG_DATA(&ctl.cmsg)) = fd;
msg.msg_control = (caddr_t) &ctl;
msg.msg_controllen = ctl.cmsg.cmsg_len;
}
/*
* Send to kernel...
*/
if ((n = sendmsg(so, &msg, 0)) < 0)
syslog(LOG_ERR, "send: %s", strerror(errno));
#ifdef DEBUG
fprintf(stderr, "sent %d bytes\n", n);
#endif
sleep(1); /*XXX*/
#ifdef notdef
if (shutdown(so, 2) < 0)
syslog(LOG_ERR, "shutdown: %s", strerror(errno));
#endif
/*
* Throw away the open file descriptor
*/
(void) close(fd);
}
void activate(q, so)
qelem *q;
int so;
{
struct portal_cred pcred;
char key[MAXPATHLEN+1];
int error;
char **v;
int fd = -1;
/*
* Read the key from the socket
*/
error = get_request(so, &pcred, key, sizeof(key));
if (error) {
syslog(LOG_ERR, "activate: recvmsg: %s", strerror(error));
goto drop;
}
#ifdef DEBUG
fprintf(stderr, "lookup key %s\n", key);
#endif
/*
* Find a match in the configuration file
*/
v = conf_match(q, key);
/*
* If a match existed, then find an appropriate portal
* otherwise simply return ENOENT.
*/
if (v) {
error = activate_argv(&pcred, key, v, so, &fd);
if (error)
fd = -1;
else if (fd < 0)
error = -1;
} else {
error = ENOENT;
}
if (error >= 0)
send_reply(so, fd, error);
drop:;
close(so);
}