efi/loader/devicename.c

	devicename.c revision 199767f8919635c4928607450d9e0abb932109ce
/*-
 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
 * Copyright (c) 2006 Marcel Moolenaar
 * 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 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 <stand.h>
#include <string.h>
#include <sys/disklabel.h>
#include <sys/param.h>
#include <bootstrap.h>
#ifdef EFI_ZFS_BOOT
#include <libzfs.h>
#endif

#include <efi.h>
#include <efilib.h>

#include "loader_efi.h"

static int efi_parsedev(struct devdesc **, const char *, const char **);

/*
 * Point (dev) at an allocated device specifier for the device matching the
 * path in (devspec). If it contains an explicit device specification,
 * use that.  If not, use the default device.
 */
int
efi_getdev(void **vdev, const char *devspec, const char **path)
{
    struct devdesc **dev = (struct devdesc **)vdev;
    int rv;

    /*
     * If it looks like this is just a path and no device, then
     * use the current device instead.
     */
    if (devspec == NULL || *devspec == '/' || !strchr(devspec, ':')) {
        rv = efi_parsedev(dev, getenv("currdev"), NULL);
        if (rv == 0 && path != NULL)
            *path = devspec;
        return (rv);
    }

    /* Parse the device name off the beginning of the devspec. */
    return (efi_parsedev(dev, devspec, path));
}

/*
 * Point (dev) at an allocated device specifier matching the string version
 * at the beginning of (devspec).  Return a pointer to the remaining
 * text in (path).
 *
 * In all cases, the beginning of (devspec) is compared to the names
 * of known devices in the device switch, and then any following text
 * is parsed according to the rules applied to the device type.
 *
 * For disk-type devices, the syntax is:
 *
 * fs<unit>:
 */
static int
efi_parsedev(struct devdesc **dev, const char *devspec, const char **path)
{
    struct devdesc *idev;
    struct devsw *dv;
    char *cp;
    const char *np;
    int i;

    /* minimum length check */
    if (strlen(devspec) < 2)
        return (EINVAL);

    /* look for a device that matches */
    for (i = 0; devsw[i] != NULL; i++) {
        dv = devsw[i];
        if (!strncmp(devspec, dv->dv_name, strlen(dv->dv_name)))
            break;
    }
    if (devsw[i] == NULL)
        return (ENOENT);

    np = devspec + strlen(dv->dv_name);

#ifdef EFI_ZFS_BOOT
    if (dv->dv_type == DEVT_ZFS) {
        int err;

        idev = malloc(sizeof(struct zfs_devdesc));
        if (idev == NULL)
            return (ENOMEM);

        err = zfs_parsedev((struct zfs_devdesc*)idev, np, path);
        if (err != 0) {
            free(idev);
            return (err);
        }
        *dev = idev;
        cp = strchr(np + 1, ':');
    } else
#endif
    {
        idev = malloc(sizeof(struct devdesc));
        if (idev == NULL)
            return (ENOMEM);

        idev->d_dev = dv;
        idev->d_type = dv->dv_type;
        idev->d_unit = -1;
        if (*np != '\0' && *np != ':') {
            idev->d_unit = strtol(np, &cp, 0);
            if (cp == np) {
                idev->d_unit = -1;
                free(idev);
                return (EUNIT);
            }
        }
    }

    if (*cp != '\0' && *cp != ':') {
        free(idev);
        return (EINVAL);
    }

    if (path != NULL)
        *path = (*cp == 0) ? cp : cp + 1;
    if (dev != NULL)
        *dev = idev;
    else
        free(idev);
    return (0);
}

char *
efi_fmtdev(void *vdev)
{
    struct devdesc *dev = (struct devdesc *)vdev;
    static char buf[SPECNAMELEN + 1];

    switch(dev->d_type) {
#ifdef EFI_ZFS_BOOT
    case DEVT_ZFS:
        return (zfs_fmtdev(dev));
#endif
    case DEVT_NONE:
        strcpy(buf, "(no device)");
        break;

    default:
        sprintf(buf, "%s%d:", dev->d_dev->dv_name, dev->d_unit);
        break;
    }

    return (buf);
}

/*
 * Set currdev to suit the value being supplied in (value)
 */
int
efi_setcurrdev(struct env_var *ev, int flags, const void *value)
{
    struct devdesc *ncurr;
    int rv;

    rv = efi_parsedev(&ncurr, value, NULL);
    if (rv != 0)
        return (rv);

    free(ncurr);
    env_setenv(ev->ev_name, flags | EV_NOHOOK, value, NULL, NULL);
    return (0);
}