config root man

/*
 * 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.
 * 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
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/usr.sbin/mount_portalfs/activate.c 166157 2007-01-20 21:35:11Z rodrigc $");

#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(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(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 <= (int)sizeof(*pcr))
		return (EINVAL);

	n -= sizeof(*pcr);
	key[n] = '\0';

	return (0);
}

static void send_reply(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, SHUT_RDWR) < 0)
		syslog(LOG_ERR, "shutdown: %s", strerror(errno));
#endif
	/*
	 * Throw away the open file descriptor
	 */
	(void) close(fd);
}

void activate(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);
}