libgrubmgmt/common/libgrub_cmd.c

	libgrub_cmd.c revision fda6624021ffe01adf1af44f72ae4fb3ba65c1e8
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte/*
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * CDDL HEADER START
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte *
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * The contents of this file are subject to the terms of the
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * Common Development and Distribution License (the "License").
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * You may not use this file except in compliance with the License.
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte *
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * or http://www.opensolaris.org/os/licensing.
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * See the License for the specific language governing permissions
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * and limitations under the License.
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte *
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * When distributing Covered Code, include this CDDL HEADER in each
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * If applicable, add the following below this CDDL HEADER, with the
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * fields enclosed by brackets "[]" replaced with your own identifying
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * information: Portions Copyright [yyyy] [name of copyright owner]
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte *
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * CDDL HEADER END
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte */
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte/*
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * Use is subject to license terms.
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte */
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte/*
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * This file contains all the functions that implement the following
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * GRUB commands:
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte *  kernel, kernel$, module, module$, findroot, bootfs
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * Return 0 on success, errno on failure.
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte */
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <stdio.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <stdlib.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <assert.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <alloca.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <errno.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <strings.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <unistd.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <fcntl.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <sys/types.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <sys/fs/ufs_mount.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <sys/dktp/fdisk.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#if defined(__i386)
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include <sys/x86_archext.h>
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#endif /* __i386 */
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#include "libgrub_impl.h"
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#define RESET_MODULE(barg)  ((barg)->gb_module[0] = 0)
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#if defined(__i386)
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Fortestatic const char cpuid_dev[] = "/dev/cpu/self/cpuid";
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte/*
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * Return 1 if the system supports 64-bit mode, 0 if it doesn't,
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * or -1 on failure.
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte */
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Fortestatic int
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Fortecpuid_64bit_capable(void)
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte{
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte    int fd, ret = -1;
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte    struct {
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte        uint32_t cp_eax, cp_ebx, cp_ecx, cp_edx;
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte    } cpuid_regs;
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte    if ((fd = open(cpuid_dev, O_RDONLY)) == -1)
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte        return (ret);
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte    if (pread(fd, &cpuid_regs, sizeof (cpuid_regs), 0x80000001) ==
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte        sizeof (cpuid_regs))
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte        ret = ((CPUID_AMD_EDX_LM & cpuid_regs.cp_edx) != 0);
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte    (void) close(fd);
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte    return (ret);
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte}
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#endif /* __i386 */
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte/*
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte * Expand $ISAIDR
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte */
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#if !defined(__i386)
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte/* ARGSUSED */
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Forte#endif /* __i386 */
fcf3ce441efd61da9bb2884968af01cb7c1452ccJohn Fortestatic size_t
barg_isadir_var(char *var, int sz)
{
#if defined(__i386)
    if (cpuid_64bit_capable() == 1)
        return (strlcpy(var, "amd64", sz));
#endif /* __i386 */

    var[0] = 0;
    return (0);
}

/*
 * Expand $ZFS-BOOTFS
 */
static size_t
barg_bootfs_var(const grub_barg_t *barg, char *var, int sz)
{
    int n;

    assert(barg);
    if (strcmp(barg->gb_root.gr_fstyp, MNTTYPE_ZFS) == 0) {
        n = snprintf(var, sz, "zfs-bootfs=%s,bootpath=\"%s\"",
            barg->gb_root.gr_fs[GRBM_ZFS_BOOTFS].gfs_dev,
            barg->gb_root.gr_physpath);
    } else  {
        var[0] = 0;
        n = 0;
    }
    return (n);
}

/*
 * Expand all the variables without appending them more than once.
 */
static int
expand_var(char *arg, size_t argsz, const char *var, size_t varsz,
    char *val, size_t valsz)
{
    char    *sp = arg;
    size_t  sz = argsz, len;
    char    *buf, *dst, *src;
    int ret = 0;

    buf = alloca(argsz);
    dst = buf;

    while ((src = strstr(sp, var)) != NULL) {

        len = src - sp;

        if (len + valsz > sz) {
            ret = E2BIG;
            break;
        }

        (void) bcopy(sp, dst, len);
        (void) bcopy(val, dst + len, valsz);
        dst += len + valsz;
        sz -= len + valsz;
        sp = src + varsz;
    }

    if (strlcpy(dst, sp, sz) >= sz)
        ret = E2BIG;

    if (ret == 0)
        bcopy(buf, arg, argsz);
    return (ret);
}

static int
match_bootfs(zfs_handle_t *zfh, void *data)
{
    int     ret;
    const char  *zfn;
    grub_barg_t *barg = (grub_barg_t *)data;

    ret = (zfs_get_type(zfh) == ZFS_TYPE_FILESYSTEM &&
        (zfn = zfs_get_name(zfh)) != NULL &&
        strcmp(barg->gb_root.gr_fs[GRBM_ZFS_BOOTFS].gfs_dev, zfn) == 0);

    if (ret != 0)
        barg->gb_walkret = 0;
    else
        (void) zfs_iter_filesystems(zfh, match_bootfs, barg);

    zfs_close(zfh);
    return (barg->gb_walkret == 0);
}

static void
reset_root(grub_barg_t *barg)
{
    (void) memset(&barg->gb_root, 0, sizeof (barg->gb_root));
    barg->gb_bootsign[0] = 0;
    barg->gb_kernel[0] = 0;
    RESET_MODULE(barg);
}

/* ARGSUSED */
int
skip_line(const grub_line_t *lp, grub_barg_t *barg)
{
    return (0);
}

/* ARGSUSED */
int
error_line(const grub_line_t *lp, grub_barg_t *barg)
{
    if (lp->gl_cmdtp == GRBM_ROOT_CMD)
        return (EG_ROOTNOTSUPP);
    return (EG_INVALIDLINE);
}

int
kernel(const grub_line_t *lp, grub_barg_t *barg)
{
    RESET_MODULE(barg);
    if (strlcpy(barg->gb_kernel, lp->gl_arg, sizeof (barg->gb_kernel)) >=
        sizeof (barg->gb_kernel))
        return (E2BIG);

    return (0);
}

int
module(const grub_line_t *lp, grub_barg_t *barg)
{
    if (strlcpy(barg->gb_module, lp->gl_arg, sizeof (barg->gb_module)) >=
        sizeof (barg->gb_module))
        return (E2BIG);

    return (0);
}

int
dollar_kernel(const grub_line_t *lp, grub_barg_t *barg)
{
    int ret;
    size_t  bfslen, isalen;
    char    isadir[32];
    char    bootfs[BOOTARGS_MAX];

    RESET_MODULE(barg);
    if (strlcpy(barg->gb_kernel, lp->gl_arg, sizeof (barg->gb_kernel)) >=
        sizeof (barg->gb_kernel))
        return (E2BIG);

    bfslen = barg_bootfs_var(barg, bootfs, sizeof (bootfs));
    isalen = barg_isadir_var(isadir, sizeof (isadir));

    if (bfslen >= sizeof (bootfs) || isalen >= sizeof (isadir))
        return (EINVAL);

    if ((ret = expand_var(barg->gb_kernel, sizeof (barg->gb_kernel),
        ZFS_BOOT_VAR, strlen(ZFS_BOOT_VAR), bootfs, bfslen)) != 0)
        return (ret);

    ret = expand_var(barg->gb_kernel, sizeof (barg->gb_kernel),
        ISADIR_VAR, strlen(ISADIR_VAR), isadir, isalen);

    return (ret);
}

int
dollar_module(const grub_line_t *lp, grub_barg_t *barg)
{
    int ret;
    size_t  isalen;
    char    isadir[32];

    if (strlcpy(barg->gb_module, lp->gl_arg, sizeof (barg->gb_module)) >=
        sizeof (barg->gb_module))
        return (E2BIG);

    if ((isalen = barg_isadir_var(isadir, sizeof (isadir))) >= sizeof
        (isadir))
        return (EINVAL);

    ret = expand_var(barg->gb_module, sizeof (barg->gb_module),
        ISADIR_VAR, strlen(ISADIR_VAR), isadir, isalen);

    return (ret);
}


int
findroot(const grub_line_t *lp, grub_barg_t *barg)
{
    size_t sz, bsz;
    const char *sign;

    reset_root(barg);

    sign = lp->gl_arg;
    barg->gb_prtnum = (uint_t)PRTNUM_INVALID;
    barg->gb_slcnum = (uint_t)SLCNUM_WHOLE_DISK;

    if (sign[0] == '(') {
        const char *pos;

        ++sign;
        if ((pos = strchr(sign, ',')) == NULL || (sz = pos - sign) == 0)
            return (EG_FINDROOTFMT);

        ++pos;
        if (!IS_PRTNUM_VALID(barg->gb_prtnum = pos[0] - '0'))
            return (EG_FINDROOTFMT);

        ++pos;
        if (pos[0] != ',' ||
            !IS_SLCNUM_VALID(barg->gb_slcnum = pos[1]) ||
            pos[2] != ')')
            return (EG_FINDROOTFMT);
    } else {
        sz = strlen(sign);
    }

    bsz = strlen(BOOTSIGN_DIR "/");
    if (bsz + sz + 1 > sizeof (barg->gb_bootsign))
        return (E2BIG);

    bcopy(BOOTSIGN_DIR "/", barg->gb_bootsign, bsz);
    bcopy(sign, barg->gb_bootsign + bsz, sz);
    barg->gb_bootsign [bsz + sz] = 0;

    return (grub_find_bootsign(barg));
}

int
bootfs(const grub_line_t *lp, grub_barg_t *barg)
{
    zfs_handle_t    *zfh;
    grub_menu_t *mp = barg->gb_entry->ge_menu;
    char        *gfs_devp;
    size_t      gfs_dev_len;

    /* Check if root is zfs */
    if (strcmp(barg->gb_root.gr_fstyp, MNTTYPE_ZFS) != 0)
        return (EG_NOTZFS);

    gfs_devp = barg->gb_root.gr_fs[GRBM_ZFS_BOOTFS].gfs_dev;
    gfs_dev_len = sizeof (barg->gb_root.gr_fs[GRBM_ZFS_BOOTFS].gfs_dev);

    /*
     * If the bootfs value is the same as the bootfs for the pool,
     * do nothing.
     */
    if (strcmp(lp->gl_arg, gfs_devp) == 0)
        return (0);

    if (strlcpy(gfs_devp, lp->gl_arg, gfs_dev_len) >= gfs_dev_len)
        return (E2BIG);

    /* check if specified bootfs belongs to the root pool */
    if ((zfh = zfs_open(mp->gm_fs.gf_lzfh,
        barg->gb_root.gr_fs[GRBM_ZFS_TOPFS].gfs_dev,
        ZFS_TYPE_FILESYSTEM)) == NULL)
        return (EG_OPENZFS);

    barg->gb_walkret = EG_UNKBOOTFS;
    (void) zfs_iter_filesystems(zfh, match_bootfs, barg);
    zfs_close(zfh);

    if (barg->gb_walkret == 0)
        (void) grub_fsd_get_mountp(barg->gb_root.gr_fs +
            GRBM_ZFS_BOOTFS, MNTTYPE_ZFS);

    return (barg->gb_walkret);
}