freebsd/lib/libdevctl/devctl.c

/*-
 * Copyright (c) 2014 John Baldwin <jhb@FreeBSD.org>
 *
 * 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 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 AUTHOR 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.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/types.h>
#include <sys/bus.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include "devctl.h"

static int
devctl_request(u_long cmd, struct devreq *req)
{
	static int devctl2_fd = -1;

	if (devctl2_fd == -1) {
		devctl2_fd = open("/dev/devctl2", O_RDONLY);
		if (devctl2_fd == -1)
			return (-1);
	}
	return (ioctl(devctl2_fd, cmd, req));
}

static int
devctl_simple_request(u_long cmd, const char *name, int flags)
{
	struct devreq req;

	memset(&req, 0, sizeof(req));
	if (strlcpy(req.dr_name, name, sizeof(req.dr_name)) >=
	    sizeof(req.dr_name)) {
		errno = EINVAL;
		return (-1);
	}
	req.dr_flags = flags;
	return (devctl_request(cmd, &req));
}

int
devctl_attach(const char *device)
{

	return (devctl_simple_request(DEV_ATTACH, device, 0));
}

int
devctl_detach(const char *device, bool force)
{

	return (devctl_simple_request(DEV_DETACH, device, force ?
	    DEVF_FORCE_DETACH : 0));
}

int
devctl_enable(const char *device)
{

	return (devctl_simple_request(DEV_ENABLE, device, 0));
}

int
devctl_disable(const char *device, bool force_detach)
{

	return (devctl_simple_request(DEV_DISABLE, device, force_detach ?
	    DEVF_FORCE_DETACH : 0));
}

int
devctl_suspend(const char *device)
{

	return (devctl_simple_request(DEV_SUSPEND, device, 0));
}

int
devctl_resume(const char *device)
{

	return (devctl_simple_request(DEV_RESUME, device, 0));
}

int
devctl_set_driver(const char *device, const char *driver, bool force)
{
	struct devreq req;

	memset(&req, 0, sizeof(req));
	if (strlcpy(req.dr_name, device, sizeof(req.dr_name)) >=
	    sizeof(req.dr_name)) {
		errno = EINVAL;
		return (-1);
	}
	req.dr_data = __DECONST(char *, driver);
	if (force)
		req.dr_flags |= DEVF_SET_DRIVER_DETACH;
	return (devctl_request(DEV_SET_DRIVER, &req));
}

int
devctl_clear_driver(const char *device, bool force)
{

	return (devctl_simple_request(DEV_CLEAR_DRIVER, device, force ?
	    DEVF_CLEAR_DRIVER_DETACH : 0));
}

int
devctl_rescan(const char *device)
{

	return (devctl_simple_request(DEV_RESCAN, device, 0));
}

int
devctl_delete(const char *device, bool force)
{

	return (devctl_simple_request(DEV_DELETE, device, force ?
	    DEVF_FORCE_DELETE : 0));
}

int
devctl_freeze(void)
{

	return (devctl_simple_request(DEV_FREEZE, "", 0));
}

int
devctl_thaw(void)
{

	return (devctl_simple_request(DEV_THAW, "", 0));
}

int
devctl_reset(const char *device, bool detach)
{

	return (devctl_simple_request(DEV_RESET, device, detach ?
	    DEVF_RESET_DETACH : 0));
}

#define BUFLEN 1024

int
devctl_getpath(const char *device, const char *locator, char **buffer)
{
	struct devreq req;
	int serrno;

	memset(&req, 0, sizeof(req));
	if (strlcpy(req.dr_name, device, sizeof(req.dr_name)) >=
	    sizeof(req.dr_name)) {
		errno = EINVAL;
		*buffer = NULL;
		return (-1);
	}

	/*
	 * Maybe do the request twice. Once to get the length, and then again to
	 * get the string if BUFLEN bytes is insufficient.
	 */
	req.dr_flags = 0;
	req.dr_buffer.length = BUFLEN;
again:
	req.dr_buffer.buffer = malloc(req.dr_buffer.length);
	strlcpy(req.dr_buffer.buffer, locator, req.dr_buffer.length);
	if (devctl_request(DEV_GET_PATH, &req) == 0) {
		*buffer = req.dr_buffer.buffer;
		return (0);
	}
	if (errno == ENAMETOOLONG && req.dr_buffer.length != BUFLEN) {
		free(req.dr_buffer.buffer);
		goto again;
	}
	serrno = errno;
	free(req.dr_buffer.buffer);
	errno = serrno;
	*buffer = NULL;
	return (-1);
}