text: /*-
   * Copyright (c) 2002 Poul-Henning Kamp
   * Copyright (c) 2002 Networks Associates Technology, Inc.
   * All rights reserved.
   *
   * This software was developed for the FreeBSD Project by Poul-Henning Kamp
   * and NAI Labs, the Security Research Division of Network Associates, Inc.
   * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
   * DARPA CHATS research program.
   *
   * 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/param.h>
  #include <sys/errno.h>
  #include <sys/endian.h>
  #include <sys/systm.h>
  #include <sys/sysctl.h>
  #include <sys/kernel.h>
  #include <sys/fcntl.h>
  #include <sys/malloc.h>
  #include <sys/bio.h>
  #include <sys/lock.h>
  #include <sys/mutex.h>
  #include <sys/md5.h>
  #include <sys/proc.h>
  
  #include <sys/diskmbr.h>
  #include <sys/sbuf.h>
  #include <geom/geom.h>
  #include <geom/geom_slice.h>
  
  FEATURE(geom_mbr, "GEOM DOS/MBR partitioning support");
  
  #define MBR_CLASS_NAME "MBR"
  #define MBREXT_CLASS_NAME "MBREXT"
  
  static struct dos_partition historical_bogus_partition_table[NDOSPART] = {
          { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
          { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
          { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
          { 0x80, 0, 1, 0, DOSPTYP_386BSD, 255, 255, 255, 0, 50000, },
  };
  
  static struct dos_partition historical_bogus_partition_table_fixed[NDOSPART] = {
          { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
          { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
          { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
          { 0x80, 0, 1, 0, DOSPTYP_386BSD, 254, 255, 255, 0, 50000, },
  };
  
  static void
  g_mbr_print(int i, struct dos_partition *dp)
  {
  
  	printf("[%d] f:%02x typ:%d", i, dp->dp_flag, dp->dp_typ);
  	printf(" s(CHS):%d/%d/%d", DPCYL(dp->dp_scyl, dp->dp_ssect),
  	    dp->dp_shd, DPSECT(dp->dp_ssect));
  	printf(" e(CHS):%d/%d/%d", DPCYL(dp->dp_ecyl, dp->dp_esect),
  	    dp->dp_ehd, DPSECT(dp->dp_esect));
  	printf(" s:%d l:%d\n", dp->dp_start, dp->dp_size);
  }
  
  struct g_mbr_softc {
  	int		type [NDOSPART];
  	u_int		sectorsize;
  	u_char		sec0[512];
  	u_char		slicesum[16];
  };
  
  /*
   * XXX: Add gctl_req arg and give good error msgs.
   * XXX: Check that length argument does not bring boot code inside any slice.
   */
  static int
  g_mbr_modify(struct g_geom *gp, struct g_mbr_softc *ms, u_char *sec0, int len __unused)
  {
  	int i, error;
  	off_t l[NDOSPART];
  	struct dos_partition ndp[NDOSPART], *dp;
  	MD5_CTX md5sum;
  
  	g_topology_assert();
  
  	if (sec0[0x1fe] != 0x55 && sec0[0x1ff] != 0xaa)
  		return (EBUSY);
  
  	dp = ndp;
  	for (i = 0; i < NDOSPART; i++) {
  		dos_partition_dec(
  		    sec0 + DOSPARTOFF + i * sizeof(struct dos_partition),
  		    dp + i);
  	}
  	if ((!bcmp(dp, historical_bogus_partition_table,
  	    sizeof historical_bogus_partition_table)) ||
  	    (!bcmp(dp, historical_bogus_partition_table_fixed,
  	    sizeof historical_bogus_partition_table_fixed))) {
  		/*
  		 * We will not allow people to write these from "the inside",
  		 * Since properly selfdestructing takes too much code.  If 
  		 * people really want to do this, they cannot have any
  		 * providers of this geom open, and in that case they can just
  		 * as easily overwrite the MBR in the parent device.
  		 */
  		return(EBUSY);
  	}
  	for (i = 0; i < NDOSPART; i++) {
  		/* 
  		 * A Protective MBR (PMBR) has a single partition of
  		 * type 0xEE spanning the whole disk. Such a MBR
  		 * protects a GPT on the disk from MBR tools that
  		 * don't know anything about GPT. We're interpreting
  		 * it a bit more loosely: any partition of type 0xEE
  		 * is to be skipped as it doesn't contain any data
  		 * that we should care about. We still allow other
  		 * partitions to be present in the MBR. A PMBR will
  		 * be handled correctly anyway.
  		 */
  		if (dp[i].dp_typ == DOSPTYP_PMBR)
  			l[i] = 0;
  		else if (dp[i].dp_flag != 0 && dp[i].dp_flag != 0x80)
  			l[i] = 0;
  		else if (dp[i].dp_typ == 0)
  			l[i] = 0;
  		else
  			l[i] = (off_t)dp[i].dp_size * ms->sectorsize;
  		error = g_slice_config(gp, i, G_SLICE_CONFIG_CHECK,
  		    (off_t)dp[i].dp_start * ms->sectorsize, l[i],
  		    ms->sectorsize, "%ss%d", gp->name, 1 + i);
  		if (error)
  			return (error);
  	}
  	for (i = 0; i < NDOSPART; i++) {
  		ms->type[i] = dp[i].dp_typ;
  		g_slice_config(gp, i, G_SLICE_CONFIG_SET,
  		    (off_t)dp[i].dp_start * ms->sectorsize, l[i],
  		    ms->sectorsize, "%ss%d", gp->name, 1 + i);
  	}
  	bcopy(sec0, ms->sec0, 512);
  
  	/*
  	 * Calculate MD5 from the first sector and use it for avoiding
  	 * recursive slices creation.
  	 */
  	MD5Init(&md5sum);
  	MD5Update(&md5sum, ms->sec0, sizeof(ms->sec0));
  	MD5Final(ms->slicesum, &md5sum);
  
  	return (0);
  }
  
  static int
  g_mbr_ioctl(struct g_provider *pp, u_long cmd, void *data, int fflag, struct thread *td)
  {
  	struct g_geom *gp;
  	struct g_mbr_softc *ms;
  	struct g_slicer *gsp;
  	struct g_consumer *cp;
  	int error, opened;
  
  	gp = pp->geom;
  	gsp = gp->softc;
  	ms = gsp->softc;
  
  	opened = 0;
  	error = 0;
  	switch(cmd) {
  	case DIOCSMBR: {
  		if (!(fflag & FWRITE))
  			return (EPERM);
  		g_topology_lock();
  		cp = LIST_FIRST(&gp->consumer);
  		if (cp->acw == 0) {
  			error = g_access(cp, 0, 1, 0);
  			if (error == 0)
  				opened = 1;
  		}
  		if (!error)
  			error = g_mbr_modify(gp, ms, data, 512);
  		if (!error)
  			error = g_write_data(cp, 0, data, 512);
  		if (opened)
  			g_access(cp, 0, -1 , 0);
  		g_topology_unlock();
  		return(error);
  	}
  	default:
  		return (ENOIOCTL);
  	}
  }
  
  static int
  g_mbr_start(struct bio *bp)
  {
  	struct g_provider *pp;
  	struct g_geom *gp;
  	struct g_mbr_softc *mp;
  	struct g_slicer *gsp;
  	int idx;
  
  	pp = bp->bio_to;
  	idx = pp->index;
  	gp = pp->geom;
  	gsp = gp->softc;
  	mp = gsp->softc;
  	if (bp->bio_cmd == BIO_GETATTR) {
  		if (g_handleattr_int(bp, "MBR::type", mp->type[idx]))
  			return (1);
  		if (g_handleattr_off_t(bp, "MBR::offset",
  		    gsp->slices[idx].offset))
  			return (1);
  		if (g_handleattr(bp, "MBR::slicesum", mp->slicesum,
  		    sizeof(mp->slicesum)))
  			return (1);
  	}
  
  	return (0);
  }
  
  static void
  g_mbr_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp)
  {
  	struct g_mbr_softc *mp;
  	struct g_slicer *gsp;
  
  	gsp = gp->softc;
  	mp = gsp->softc;
  	g_slice_dumpconf(sb, indent, gp, cp, pp);
  	if (pp != NULL) {
  		if (indent == NULL)
  			sbuf_printf(sb, " ty %d", mp->type[pp->index]);
  		else
  			sbuf_printf(sb, "%s<type>%d</type>\n", indent,
  			    mp->type[pp->index]);
  	}
  }
  
  static struct g_geom *
  g_mbr_taste(struct g_class *mp, struct g_provider *pp, int insist)
  {
  	struct g_geom *gp;
  	struct g_consumer *cp;
  	int error;
  	struct g_mbr_softc *ms;
  	u_int fwsectors, sectorsize;
  	u_char *buf;
  	u_char hash[16];
  	MD5_CTX md5sum;
  
  	g_trace(G_T_TOPOLOGY, "mbr_taste(%s,%s)", mp->name, pp->name);
  	g_topology_assert();
  	if (!strcmp(pp->geom->class->name, MBR_CLASS_NAME))
  		return (NULL);
  	gp = g_slice_new(mp, NDOSPART, pp, &cp, &ms, sizeof *ms, g_mbr_start);
  	if (gp == NULL)
  		return (NULL);
  	g_topology_unlock();
  	do {
  		error = g_getattr("GEOM::fwsectors", cp, &fwsectors);
  		if (error)
  			fwsectors = 17;
  		sectorsize = cp->provider->sectorsize;
  		if (sectorsize < 512)
  			break;
  		ms->sectorsize = sectorsize;
  		buf = g_read_data(cp, 0, sectorsize, NULL);
  		if (buf == NULL)
  			break;
  
  		/*
  		 * Calculate MD5 from the first sector and use it for avoiding
  		 * recursive slices creation.
  		 */
  		bcopy(buf, ms->sec0, 512);
  		MD5Init(&md5sum);
  		MD5Update(&md5sum, ms->sec0, sizeof(ms->sec0));
  		MD5Final(ms->slicesum, &md5sum);
  
  		error = g_getattr("MBR::slicesum", cp, &hash);
  		if (!error && !bcmp(ms->slicesum, hash, sizeof(hash))) {
  			g_free(buf);
  			break;
  		}
  
  		g_topology_lock();
  		g_mbr_modify(gp, ms, buf, 512);
  		g_topology_unlock();
  		g_free(buf);
  		break;
  	} while (0);
  	g_topology_lock();
  	g_access(cp, -1, 0, 0);
  	if (LIST_EMPTY(&gp->provider)) {
  		g_slice_spoiled(cp);
  		return (NULL);
  	}
  	return (gp);
  }
  
  static void
  g_mbr_config(struct gctl_req *req, struct g_class *mp, const char *verb)
  {
  	struct g_geom *gp;
  	struct g_consumer *cp;
  	struct g_mbr_softc *ms;
  	struct g_slicer *gsp;
  	int opened = 0, error = 0;
  	void *data;
  	int len;
  
  	g_topology_assert();
  	gp = gctl_get_geom(req, mp, "geom");
  	if (gp == NULL)
  		return;
  	if (strcmp(verb, "write MBR")) {
  		gctl_error(req, "Unknown verb");
  		return;
  	}
  	gsp = gp->softc;
  	ms = gsp->softc;
  	data = gctl_get_param(req, "data", &len);
  	if (data == NULL)
  		return;
  	if (len < 512 || (len % 512)) {
  		gctl_error(req, "Wrong request length");
  		return;
  	}
  	cp = LIST_FIRST(&gp->consumer);
  	if (cp->acw == 0) {
  		error = g_access(cp, 0, 1, 0);
  		if (error == 0)
  			opened = 1;
  	}
  	if (!error)
  		error = g_mbr_modify(gp, ms, data, len);
  	if (error)
  		gctl_error(req, "conflict with open slices");
  	if (!error)
  		error = g_write_data(cp, 0, data, len);
  	if (error)
  		gctl_error(req, "sector zero write failed");
  	if (opened)
  		g_access(cp, 0, -1 , 0);
  	return;
  }
  
  static struct g_class g_mbr_class	= {
  	.name = MBR_CLASS_NAME,
  	.version = G_VERSION,
  	.taste = g_mbr_taste,
  	.dumpconf = g_mbr_dumpconf,
  	.ctlreq = g_mbr_config,
  	.ioctl = g_mbr_ioctl,
  };
  
  DECLARE_GEOM_CLASS(g_mbr_class, g_mbr);
  
  #define NDOSEXTPART		32
  struct g_mbrext_softc {
  	int		type [NDOSEXTPART];
  };
  
  static int
  g_mbrext_start(struct bio *bp)
  {
  	struct g_provider *pp;
  	struct g_geom *gp;
  	struct g_mbrext_softc *mp;
  	struct g_slicer *gsp;
  	int idx;
  
  	pp = bp->bio_to;
  	idx = pp->index;
  	gp = pp->geom;
  	gsp = gp->softc;
  	mp = gsp->softc;
  	if (bp->bio_cmd == BIO_GETATTR) {
  		if (g_handleattr_int(bp, "MBR::type", mp->type[idx]))
  			return (1);
  	}
  	return (0);
  }
  
  static void
  g_mbrext_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp)
  {
  	struct g_mbrext_softc *mp;
  	struct g_slicer *gsp;
  
  	g_slice_dumpconf(sb, indent, gp, cp, pp);
  	gsp = gp->softc;
  	mp = gsp->softc;
  	if (pp != NULL) {
  		if (indent == NULL)
  			sbuf_printf(sb, " ty %d", mp->type[pp->index]);
  		else
  			sbuf_printf(sb, "%s<type>%d</type>\n", indent,
  			    mp->type[pp->index]);
  	}
  }
  
  static struct g_geom *
  g_mbrext_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
  {
  	struct g_geom *gp;
  	struct g_consumer *cp;
  	int error, i, slice;
  	struct g_mbrext_softc *ms;
  	off_t off;
  	u_char *buf;
  	struct dos_partition dp[4];
  	u_int fwsectors, sectorsize;
  
  	g_trace(G_T_TOPOLOGY, "g_mbrext_taste(%s,%s)", mp->name, pp->name);
  	g_topology_assert();
  	if (strcmp(pp->geom->class->name, MBR_CLASS_NAME))
  		return (NULL);
  	gp = g_slice_new(mp, NDOSEXTPART, pp, &cp, &ms, sizeof *ms,
  	    g_mbrext_start);
  	if (gp == NULL)
  		return (NULL);
  	g_topology_unlock();
  	off = 0;
  	slice = 0;
  	do {
  		error = g_getattr("MBR::type", cp, &i);
  		if (error || (i != DOSPTYP_EXT && i != DOSPTYP_EXTLBA))
  			break;
  		error = g_getattr("GEOM::fwsectors", cp, &fwsectors);
  		if (error)
  			fwsectors = 17;
  		sectorsize = cp->provider->sectorsize;
  		if (sectorsize != 512)
  			break;
  		for (;;) {
  			buf = g_read_data(cp, off, sectorsize, NULL);
  			if (buf == NULL)
  				break;
  			if (buf[0x1fe] != 0x55 && buf[0x1ff] != 0xaa) {
  				g_free(buf);
  				break;
  			}
  			for (i = 0; i < NDOSPART; i++) 
  				dos_partition_dec(
  				    buf + DOSPARTOFF + 
  				    i * sizeof(struct dos_partition), dp + i);
  			g_free(buf);
  			if (0 && bootverbose) {
  				printf("MBREXT Slice %d on %s:\n",
  				    slice + 5, gp->name);
  				g_mbr_print(0, dp);
  				g_mbr_print(1, dp + 1);
  			}
  			if ((dp[0].dp_flag & 0x7f) == 0 &&
  			     dp[0].dp_size != 0 && dp[0].dp_typ != 0) {
  				g_topology_lock();
  				g_slice_config(gp, slice, G_SLICE_CONFIG_SET,
  				    (((off_t)dp[0].dp_start) << 9ULL) + off,
  				    ((off_t)dp[0].dp_size) << 9ULL,
  				    sectorsize,
  				    "%*.*s%d",
  				    (int)strlen(gp->name) - 1,
  				    (int)strlen(gp->name) - 1,
  				    gp->name,
  				    slice + 5);
  				g_topology_unlock();
  				ms->type[slice] = dp[0].dp_typ;
  				slice++;
  			}
  			if (dp[1].dp_flag != 0)
  				break;
  			if (dp[1].dp_typ != DOSPTYP_EXT &&
  			    dp[1].dp_typ != DOSPTYP_EXTLBA)
  				break;
  			if (dp[1].dp_size == 0)
  				break;
  			off = ((off_t)dp[1].dp_start) << 9ULL;
  		}
  		break;
  	} while (0);
  	g_topology_lock();
  	g_access(cp, -1, 0, 0);
  	if (LIST_EMPTY(&gp->provider)) {
  		g_slice_spoiled(cp);
  		return (NULL);
  	}
  	return (gp);
  }
  
  
  static struct g_class g_mbrext_class	= {
  	.name = MBREXT_CLASS_NAME,
  	.version = G_VERSION,
  	.taste = g_mbrext_taste,
  	.dumpconf = g_mbrext_dumpconf,
  };
  
  DECLARE_GEOM_CLASS(g_mbrext_class, g_mbrext);
  