sys/geom/part/g_part_gpt.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2002, 2005-2007, 2011 Marcel Moolenaar
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <sys/param.h>
  33 #include <sys/bio.h>
  34 #include <sys/diskmbr.h>
  35 #include <sys/gsb_crc32.h>
  36 #include <sys/endian.h>
  37 #include <sys/gpt.h>
  38 #include <sys/kernel.h>
  39 #include <sys/kobj.h>
  40 #include <sys/limits.h>
  41 #include <sys/lock.h>
  42 #include <sys/malloc.h>
  43 #include <sys/mutex.h>
  44 #include <sys/queue.h>
  45 #include <sys/sbuf.h>
  46 #include <sys/systm.h>
  47 #include <sys/sysctl.h>
  48 #include <sys/uuid.h>
  49 #include <geom/geom.h>
  50 #include <geom/geom_int.h>
  51 #include <geom/part/g_part.h>
  52
  53 #include "g_part_if.h"
  54
  55 FEATURE(geom_part_gpt, "GEOM partitioning class for GPT partitions support");
  56
  57 SYSCTL_DECL(_kern_geom_part);
  58 static SYSCTL_NODE(_kern_geom_part, OID_AUTO, gpt,
  59     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
  60     "GEOM_PART_GPT GUID Partition Table");
  61
  62 static u_int allow_nesting = 0;
  63 SYSCTL_UINT(_kern_geom_part_gpt, OID_AUTO, allow_nesting,
  64     CTLFLAG_RWTUN, &allow_nesting, 0, "Allow GPT to be nested inside other schemes");
  65
  66 CTASSERT(offsetof(struct gpt_hdr, padding) == 92);
  67 CTASSERT(sizeof(struct gpt_ent) == 128);
  68
  69 extern u_int geom_part_check_integrity;
  70
  71 #define EQUUID(a,b)     (memcmp(a, b, sizeof(struct uuid)) == 0)
  72
  73 #define MBRSIZE         512
  74
  75 enum gpt_elt {
  76         GPT_ELT_PRIHDR,
  77         GPT_ELT_PRITBL,
  78         GPT_ELT_SECHDR,
  79         GPT_ELT_SECTBL,
  80         GPT_ELT_COUNT
  81 };
  82
  83 enum gpt_state {
  84         GPT_STATE_UNKNOWN,      /* Not determined. */
  85         GPT_STATE_MISSING,      /* No signature found. */
  86         GPT_STATE_CORRUPT,      /* Checksum mismatch. */
  87         GPT_STATE_INVALID,      /* Nonconformant/invalid. */
  88         GPT_STATE_OK            /* Perfectly fine. */
  89 };
  90
  91 struct g_part_gpt_table {
  92         struct g_part_table     base;
  93         u_char                  mbr[MBRSIZE];
  94         struct gpt_hdr          *hdr;
  95         quad_t                  lba[GPT_ELT_COUNT];
  96         enum gpt_state          state[GPT_ELT_COUNT];
  97         int                     bootcamp;
  98 };
  99
 100 struct g_part_gpt_entry {
 101         struct g_part_entry     base;
 102         struct gpt_ent          ent;
 103 };
 104
 105 static void g_gpt_printf_utf16(struct sbuf *, uint16_t *, size_t);
 106 static void g_gpt_utf8_to_utf16(const uint8_t *, uint16_t *, size_t);
 107 static void g_gpt_set_defaults(struct g_part_table *, struct g_provider *);
 108
 109 static int g_part_gpt_add(struct g_part_table *, struct g_part_entry *,
 110     struct g_part_parms *);
 111 static int g_part_gpt_bootcode(struct g_part_table *, struct g_part_parms *);
 112 static int g_part_gpt_create(struct g_part_table *, struct g_part_parms *);
 113 static int g_part_gpt_destroy(struct g_part_table *, struct g_part_parms *);
 114 static void g_part_gpt_dumpconf(struct g_part_table *, struct g_part_entry *,
 115     struct sbuf *, const char *);
 116 static int g_part_gpt_dumpto(struct g_part_table *, struct g_part_entry *);
 117 static int g_part_gpt_modify(struct g_part_table *, struct g_part_entry *,
 118     struct g_part_parms *);
 119 static const char *g_part_gpt_name(struct g_part_table *, struct g_part_entry *,
 120     char *, size_t);
 121 static int g_part_gpt_probe(struct g_part_table *, struct g_consumer *);
 122 static int g_part_gpt_read(struct g_part_table *, struct g_consumer *);
 123 static int g_part_gpt_setunset(struct g_part_table *table,
 124     struct g_part_entry *baseentry, const char *attrib, unsigned int set);
 125 static const char *g_part_gpt_type(struct g_part_table *, struct g_part_entry *,
 126     char *, size_t);
 127 static int g_part_gpt_write(struct g_part_table *, struct g_consumer *);
 128 static int g_part_gpt_resize(struct g_part_table *, struct g_part_entry *,
 129     struct g_part_parms *);
 130 static int g_part_gpt_recover(struct g_part_table *);
 131
 132 static kobj_method_t g_part_gpt_methods[] = {
 133         KOBJMETHOD(g_part_add,          g_part_gpt_add),
 134         KOBJMETHOD(g_part_bootcode,     g_part_gpt_bootcode),
 135         KOBJMETHOD(g_part_create,       g_part_gpt_create),
 136         KOBJMETHOD(g_part_destroy,      g_part_gpt_destroy),
 137         KOBJMETHOD(g_part_dumpconf,     g_part_gpt_dumpconf),
 138         KOBJMETHOD(g_part_dumpto,       g_part_gpt_dumpto),
 139         KOBJMETHOD(g_part_modify,       g_part_gpt_modify),
 140         KOBJMETHOD(g_part_resize,       g_part_gpt_resize),
 141         KOBJMETHOD(g_part_name,         g_part_gpt_name),
 142         KOBJMETHOD(g_part_probe,        g_part_gpt_probe),
 143         KOBJMETHOD(g_part_read,         g_part_gpt_read),
 144         KOBJMETHOD(g_part_recover,      g_part_gpt_recover),
 145         KOBJMETHOD(g_part_setunset,     g_part_gpt_setunset),
 146         KOBJMETHOD(g_part_type,         g_part_gpt_type),
 147         KOBJMETHOD(g_part_write,        g_part_gpt_write),
 148         { 0, 0 }
 149 };
 150
 151 static struct g_part_scheme g_part_gpt_scheme = {
 152         "GPT",
 153         g_part_gpt_methods,
 154         sizeof(struct g_part_gpt_table),
 155         .gps_entrysz = sizeof(struct g_part_gpt_entry),
 156         .gps_minent = 128,
 157         .gps_maxent = 4096,
 158         .gps_bootcodesz = MBRSIZE,
 159 };
 160 G_PART_SCHEME_DECLARE(g_part_gpt);
 161 MODULE_VERSION(geom_part_gpt, 0);
 162
 163 static struct uuid gpt_uuid_apple_apfs = GPT_ENT_TYPE_APPLE_APFS;
 164 static struct uuid gpt_uuid_apple_boot = GPT_ENT_TYPE_APPLE_BOOT;
 165 static struct uuid gpt_uuid_apple_core_storage =
 166     GPT_ENT_TYPE_APPLE_CORE_STORAGE;
 167 static struct uuid gpt_uuid_apple_hfs = GPT_ENT_TYPE_APPLE_HFS;
 168 static struct uuid gpt_uuid_apple_label = GPT_ENT_TYPE_APPLE_LABEL;
 169 static struct uuid gpt_uuid_apple_raid = GPT_ENT_TYPE_APPLE_RAID;
 170 static struct uuid gpt_uuid_apple_raid_offline = GPT_ENT_TYPE_APPLE_RAID_OFFLINE;
 171 static struct uuid gpt_uuid_apple_tv_recovery = GPT_ENT_TYPE_APPLE_TV_RECOVERY;
 172 static struct uuid gpt_uuid_apple_ufs = GPT_ENT_TYPE_APPLE_UFS;
 173 static struct uuid gpt_uuid_apple_zfs = GPT_ENT_TYPE_APPLE_ZFS;
 174 static struct uuid gpt_uuid_bios_boot = GPT_ENT_TYPE_BIOS_BOOT;
 175 static struct uuid gpt_uuid_chromeos_firmware = GPT_ENT_TYPE_CHROMEOS_FIRMWARE;
 176 static struct uuid gpt_uuid_chromeos_kernel = GPT_ENT_TYPE_CHROMEOS_KERNEL;
 177 static struct uuid gpt_uuid_chromeos_reserved = GPT_ENT_TYPE_CHROMEOS_RESERVED;
 178 static struct uuid gpt_uuid_chromeos_root = GPT_ENT_TYPE_CHROMEOS_ROOT;
 179 static struct uuid gpt_uuid_dfbsd_ccd = GPT_ENT_TYPE_DRAGONFLY_CCD;
 180 static struct uuid gpt_uuid_dfbsd_hammer = GPT_ENT_TYPE_DRAGONFLY_HAMMER;
 181 static struct uuid gpt_uuid_dfbsd_hammer2 = GPT_ENT_TYPE_DRAGONFLY_HAMMER2;
 182 static struct uuid gpt_uuid_dfbsd_label32 = GPT_ENT_TYPE_DRAGONFLY_LABEL32;
 183 static struct uuid gpt_uuid_dfbsd_label64 = GPT_ENT_TYPE_DRAGONFLY_LABEL64;
 184 static struct uuid gpt_uuid_dfbsd_legacy = GPT_ENT_TYPE_DRAGONFLY_LEGACY;
 185 static struct uuid gpt_uuid_dfbsd_swap = GPT_ENT_TYPE_DRAGONFLY_SWAP;
 186 static struct uuid gpt_uuid_dfbsd_ufs1 = GPT_ENT_TYPE_DRAGONFLY_UFS1;
 187 static struct uuid gpt_uuid_dfbsd_vinum = GPT_ENT_TYPE_DRAGONFLY_VINUM;
 188 static struct uuid gpt_uuid_efi = GPT_ENT_TYPE_EFI;
 189 static struct uuid gpt_uuid_freebsd = GPT_ENT_TYPE_FREEBSD;
 190 static struct uuid gpt_uuid_freebsd_boot = GPT_ENT_TYPE_FREEBSD_BOOT;
 191 static struct uuid gpt_uuid_freebsd_nandfs = GPT_ENT_TYPE_FREEBSD_NANDFS;
 192 static struct uuid gpt_uuid_freebsd_swap = GPT_ENT_TYPE_FREEBSD_SWAP;
 193 static struct uuid gpt_uuid_freebsd_ufs = GPT_ENT_TYPE_FREEBSD_UFS;
 194 static struct uuid gpt_uuid_freebsd_vinum = GPT_ENT_TYPE_FREEBSD_VINUM;
 195 static struct uuid gpt_uuid_freebsd_zfs = GPT_ENT_TYPE_FREEBSD_ZFS;
 196 static struct uuid gpt_uuid_linux_data = GPT_ENT_TYPE_LINUX_DATA;
 197 static struct uuid gpt_uuid_linux_lvm = GPT_ENT_TYPE_LINUX_LVM;
 198 static struct uuid gpt_uuid_linux_raid = GPT_ENT_TYPE_LINUX_RAID;
 199 static struct uuid gpt_uuid_linux_swap = GPT_ENT_TYPE_LINUX_SWAP;
 200 static struct uuid gpt_uuid_mbr = GPT_ENT_TYPE_MBR;
 201 static struct uuid gpt_uuid_ms_basic_data = GPT_ENT_TYPE_MS_BASIC_DATA;
 202 static struct uuid gpt_uuid_ms_ldm_data = GPT_ENT_TYPE_MS_LDM_DATA;
 203 static struct uuid gpt_uuid_ms_ldm_metadata = GPT_ENT_TYPE_MS_LDM_METADATA;
 204 static struct uuid gpt_uuid_ms_recovery = GPT_ENT_TYPE_MS_RECOVERY;
 205 static struct uuid gpt_uuid_ms_reserved = GPT_ENT_TYPE_MS_RESERVED;
 206 static struct uuid gpt_uuid_ms_spaces = GPT_ENT_TYPE_MS_SPACES;
 207 static struct uuid gpt_uuid_netbsd_ccd = GPT_ENT_TYPE_NETBSD_CCD;
 208 static struct uuid gpt_uuid_netbsd_cgd = GPT_ENT_TYPE_NETBSD_CGD;
 209 static struct uuid gpt_uuid_netbsd_ffs = GPT_ENT_TYPE_NETBSD_FFS;
 210 static struct uuid gpt_uuid_netbsd_lfs = GPT_ENT_TYPE_NETBSD_LFS;
 211 static struct uuid gpt_uuid_netbsd_raid = GPT_ENT_TYPE_NETBSD_RAID;
 212 static struct uuid gpt_uuid_netbsd_swap = GPT_ENT_TYPE_NETBSD_SWAP;
 213 static struct uuid gpt_uuid_openbsd_data = GPT_ENT_TYPE_OPENBSD_DATA;
 214 static struct uuid gpt_uuid_prep_boot = GPT_ENT_TYPE_PREP_BOOT;
 215 static struct uuid gpt_uuid_solaris_boot = GPT_ENT_TYPE_SOLARIS_BOOT;
 216 static struct uuid gpt_uuid_solaris_root = GPT_ENT_TYPE_SOLARIS_ROOT;
 217 static struct uuid gpt_uuid_solaris_swap = GPT_ENT_TYPE_SOLARIS_SWAP;
 218 static struct uuid gpt_uuid_solaris_backup = GPT_ENT_TYPE_SOLARIS_BACKUP;
 219 static struct uuid gpt_uuid_solaris_var = GPT_ENT_TYPE_SOLARIS_VAR;
 220 static struct uuid gpt_uuid_solaris_home = GPT_ENT_TYPE_SOLARIS_HOME;
 221 static struct uuid gpt_uuid_solaris_altsec = GPT_ENT_TYPE_SOLARIS_ALTSEC;
 222 static struct uuid gpt_uuid_solaris_reserved = GPT_ENT_TYPE_SOLARIS_RESERVED;
 223 static struct uuid gpt_uuid_unused = GPT_ENT_TYPE_UNUSED;
 224 static struct uuid gpt_uuid_vmfs = GPT_ENT_TYPE_VMFS;
 225 static struct uuid gpt_uuid_vmkdiag = GPT_ENT_TYPE_VMKDIAG;
 226 static struct uuid gpt_uuid_vmreserved = GPT_ENT_TYPE_VMRESERVED;
 227 static struct uuid gpt_uuid_vmvsanhdr = GPT_ENT_TYPE_VMVSANHDR;
 228
 229 static struct g_part_uuid_alias {
 230         struct uuid *uuid;
 231         int alias;
 232         int mbrtype;
 233 } gpt_uuid_alias_match[] = {
 234         { &gpt_uuid_apple_apfs,         G_PART_ALIAS_APPLE_APFS,         0 },
 235         { &gpt_uuid_apple_boot,         G_PART_ALIAS_APPLE_BOOT,         0xab },
 236         { &gpt_uuid_apple_core_storage, G_PART_ALIAS_APPLE_CORE_STORAGE, 0 },
 237         { &gpt_uuid_apple_hfs,          G_PART_ALIAS_APPLE_HFS,          0xaf },
 238         { &gpt_uuid_apple_label,        G_PART_ALIAS_APPLE_LABEL,        0 },
 239         { &gpt_uuid_apple_raid,         G_PART_ALIAS_APPLE_RAID,         0 },
 240         { &gpt_uuid_apple_raid_offline, G_PART_ALIAS_APPLE_RAID_OFFLINE, 0 },
 241         { &gpt_uuid_apple_tv_recovery,  G_PART_ALIAS_APPLE_TV_RECOVERY,  0 },
 242         { &gpt_uuid_apple_ufs,          G_PART_ALIAS_APPLE_UFS,          0 },
 243         { &gpt_uuid_apple_zfs,          G_PART_ALIAS_APPLE_ZFS,          0 },
 244         { &gpt_uuid_bios_boot,          G_PART_ALIAS_BIOS_BOOT,          0 },
 245         { &gpt_uuid_chromeos_firmware,  G_PART_ALIAS_CHROMEOS_FIRMWARE,  0 },
 246         { &gpt_uuid_chromeos_kernel,    G_PART_ALIAS_CHROMEOS_KERNEL,    0 },
 247         { &gpt_uuid_chromeos_reserved,  G_PART_ALIAS_CHROMEOS_RESERVED,  0 },
 248         { &gpt_uuid_chromeos_root,      G_PART_ALIAS_CHROMEOS_ROOT,      0 },
 249         { &gpt_uuid_dfbsd_ccd,          G_PART_ALIAS_DFBSD_CCD,          0 },
 250         { &gpt_uuid_dfbsd_hammer,       G_PART_ALIAS_DFBSD_HAMMER,       0 },
 251         { &gpt_uuid_dfbsd_hammer2,      G_PART_ALIAS_DFBSD_HAMMER2,      0 },
 252         { &gpt_uuid_dfbsd_label32,      G_PART_ALIAS_DFBSD,              0xa5 },
 253         { &gpt_uuid_dfbsd_label64,      G_PART_ALIAS_DFBSD64,            0xa5 },
 254         { &gpt_uuid_dfbsd_legacy,       G_PART_ALIAS_DFBSD_LEGACY,       0 },
 255         { &gpt_uuid_dfbsd_swap,         G_PART_ALIAS_DFBSD_SWAP,         0 },
 256         { &gpt_uuid_dfbsd_ufs1,         G_PART_ALIAS_DFBSD_UFS,          0 },
 257         { &gpt_uuid_dfbsd_vinum,        G_PART_ALIAS_DFBSD_VINUM,        0 },
 258         { &gpt_uuid_efi,                G_PART_ALIAS_EFI,                0xee },
 259         { &gpt_uuid_freebsd,            G_PART_ALIAS_FREEBSD,            0xa5 },
 260         { &gpt_uuid_freebsd_boot,       G_PART_ALIAS_FREEBSD_BOOT,       0 },
 261         { &gpt_uuid_freebsd_nandfs,     G_PART_ALIAS_FREEBSD_NANDFS,     0 },
 262         { &gpt_uuid_freebsd_swap,       G_PART_ALIAS_FREEBSD_SWAP,       0 },
 263         { &gpt_uuid_freebsd_ufs,        G_PART_ALIAS_FREEBSD_UFS,        0 },
 264         { &gpt_uuid_freebsd_vinum,      G_PART_ALIAS_FREEBSD_VINUM,      0 },
 265         { &gpt_uuid_freebsd_zfs,        G_PART_ALIAS_FREEBSD_ZFS,        0 },
 266         { &gpt_uuid_linux_data,         G_PART_ALIAS_LINUX_DATA,         0x0b },
 267         { &gpt_uuid_linux_lvm,          G_PART_ALIAS_LINUX_LVM,          0 },
 268         { &gpt_uuid_linux_raid,         G_PART_ALIAS_LINUX_RAID,         0 },
 269         { &gpt_uuid_linux_swap,         G_PART_ALIAS_LINUX_SWAP,         0 },
 270         { &gpt_uuid_mbr,                G_PART_ALIAS_MBR,                0 },
 271         { &gpt_uuid_ms_basic_data,      G_PART_ALIAS_MS_BASIC_DATA,      0x0b },
 272         { &gpt_uuid_ms_ldm_data,        G_PART_ALIAS_MS_LDM_DATA,        0 },
 273         { &gpt_uuid_ms_ldm_metadata,    G_PART_ALIAS_MS_LDM_METADATA,    0 },
 274         { &gpt_uuid_ms_recovery,        G_PART_ALIAS_MS_RECOVERY,        0 },
 275         { &gpt_uuid_ms_reserved,        G_PART_ALIAS_MS_RESERVED,        0 },
 276         { &gpt_uuid_ms_spaces,          G_PART_ALIAS_MS_SPACES,          0 },
 277         { &gpt_uuid_netbsd_ccd,         G_PART_ALIAS_NETBSD_CCD,         0 },
 278         { &gpt_uuid_netbsd_cgd,         G_PART_ALIAS_NETBSD_CGD,         0 },
 279         { &gpt_uuid_netbsd_ffs,         G_PART_ALIAS_NETBSD_FFS,         0 },
 280         { &gpt_uuid_netbsd_lfs,         G_PART_ALIAS_NETBSD_LFS,         0 },
 281         { &gpt_uuid_netbsd_raid,        G_PART_ALIAS_NETBSD_RAID,        0 },
 282         { &gpt_uuid_netbsd_swap,        G_PART_ALIAS_NETBSD_SWAP,        0 },
 283         { &gpt_uuid_openbsd_data,       G_PART_ALIAS_OPENBSD_DATA,       0 },
 284         { &gpt_uuid_prep_boot,          G_PART_ALIAS_PREP_BOOT,          0x41 },
 285         { &gpt_uuid_solaris_boot,       G_PART_ALIAS_SOLARIS_BOOT,       0 },
 286         { &gpt_uuid_solaris_root,       G_PART_ALIAS_SOLARIS_ROOT,       0 },
 287         { &gpt_uuid_solaris_swap,       G_PART_ALIAS_SOLARIS_SWAP,       0 },
 288         { &gpt_uuid_solaris_backup,     G_PART_ALIAS_SOLARIS_BACKUP,     0 },
 289         { &gpt_uuid_solaris_var,        G_PART_ALIAS_SOLARIS_VAR,        0 },
 290         { &gpt_uuid_solaris_home,       G_PART_ALIAS_SOLARIS_HOME,       0 },
 291         { &gpt_uuid_solaris_altsec,     G_PART_ALIAS_SOLARIS_ALTSEC,     0 },
 292         { &gpt_uuid_solaris_reserved,   G_PART_ALIAS_SOLARIS_RESERVED,   0 },
 293         { &gpt_uuid_vmfs,               G_PART_ALIAS_VMFS,               0 },
 294         { &gpt_uuid_vmkdiag,            G_PART_ALIAS_VMKDIAG,            0 },
 295         { &gpt_uuid_vmreserved,         G_PART_ALIAS_VMRESERVED,         0 },
 296         { &gpt_uuid_vmvsanhdr,          G_PART_ALIAS_VMVSANHDR,          0 },
 297         { NULL, 0, 0 }
 298 };
 299
 300 static int
 301 gpt_write_mbr_entry(u_char *mbr, int idx, int typ, quad_t start,
 302     quad_t end)
 303 {
 304
 305         if (typ == 0 || start > UINT32_MAX || end > UINT32_MAX)
 306                 return (EINVAL);
 307
 308         mbr += DOSPARTOFF + idx * DOSPARTSIZE;
 309         mbr[0] = 0;
 310         if (start == 1) {
 311                 /*
 312                  * Treat the PMBR partition specially to maximize
 313                  * interoperability with BIOSes.
 314                  */
 315                 mbr[1] = mbr[3] = 0;
 316                 mbr[2] = 2;
 317         } else
 318                 mbr[1] = mbr[2] = mbr[3] = 0xff;
 319         mbr[4] = typ;
 320         mbr[5] = mbr[6] = mbr[7] = 0xff;
 321         le32enc(mbr + 8, (uint32_t)start);
 322         le32enc(mbr + 12, (uint32_t)(end - start + 1));
 323         return (0);
 324 }
 325
 326 static int
 327 gpt_map_type(struct uuid *t)
 328 {
 329         struct g_part_uuid_alias *uap;
 330
 331         for (uap = &gpt_uuid_alias_match[0]; uap->uuid; uap++) {
 332                 if (EQUUID(t, uap->uuid))
 333                         return (uap->mbrtype);
 334         }
 335         return (0);
 336 }
 337
 338 static void
 339 gpt_create_pmbr(struct g_part_gpt_table *table, struct g_provider *pp)
 340 {
 341
 342         bzero(table->mbr + DOSPARTOFF, DOSPARTSIZE * NDOSPART);
 343         gpt_write_mbr_entry(table->mbr, 0, 0xee, 1,
 344             MIN(pp->mediasize / pp->sectorsize - 1, UINT32_MAX));
 345         le16enc(table->mbr + DOSMAGICOFFSET, DOSMAGIC);
 346 }
 347
 348 /*
 349  * Under Boot Camp the PMBR partition (type 0xEE) doesn't cover the
 350  * whole disk anymore. Rather, it covers the GPT table and the EFI
 351  * system partition only. This way the HFS+ partition and any FAT
 352  * partitions can be added to the MBR without creating an overlap.
 353  */
 354 static int
 355 gpt_is_bootcamp(struct g_part_gpt_table *table, const char *provname)
 356 {
 357         uint8_t *p;
 358
 359         p = table->mbr + DOSPARTOFF;
 360         if (p[4] != 0xee || le32dec(p + 8) != 1)
 361                 return (0);
 362
 363         p += DOSPARTSIZE;
 364         if (p[4] != 0xaf)
 365                 return (0);
 366
 367         printf("GEOM: %s: enabling Boot Camp\n", provname);
 368         return (1);
 369 }
 370
 371 static void
 372 gpt_update_bootcamp(struct g_part_table *basetable, struct g_provider *pp)
 373 {
 374         struct g_part_entry *baseentry;
 375         struct g_part_gpt_entry *entry;
 376         struct g_part_gpt_table *table;
 377         int bootable, error, index, slices, typ;
 378
 379         table = (struct g_part_gpt_table *)basetable;
 380
 381         bootable = -1;
 382         for (index = 0; index < NDOSPART; index++) {
 383                 if (table->mbr[DOSPARTOFF + DOSPARTSIZE * index])
 384                         bootable = index;
 385         }
 386
 387         bzero(table->mbr + DOSPARTOFF, DOSPARTSIZE * NDOSPART);
 388         slices = 0;
 389         LIST_FOREACH(baseentry, &basetable->gpt_entry, gpe_entry) {
 390                 if (baseentry->gpe_deleted)
 391                         continue;
 392                 index = baseentry->gpe_index - 1;
 393                 if (index >= NDOSPART)
 394                         continue;
 395
 396                 entry = (struct g_part_gpt_entry *)baseentry;
 397
 398                 switch (index) {
 399                 case 0: /* This must be the EFI system partition. */
 400                         if (!EQUUID(&entry->ent.ent_type, &gpt_uuid_efi))
 401                                 goto disable;
 402                         error = gpt_write_mbr_entry(table->mbr, index, 0xee,
 403                             1ull, entry->ent.ent_lba_end);
 404                         break;
 405                 case 1: /* This must be the HFS+ partition. */
 406                         if (!EQUUID(&entry->ent.ent_type, &gpt_uuid_apple_hfs))
 407                                 goto disable;
 408                         error = gpt_write_mbr_entry(table->mbr, index, 0xaf,
 409                             entry->ent.ent_lba_start, entry->ent.ent_lba_end);
 410                         break;
 411                 default:
 412                         typ = gpt_map_type(&entry->ent.ent_type);
 413                         error = gpt_write_mbr_entry(table->mbr, index, typ,
 414                             entry->ent.ent_lba_start, entry->ent.ent_lba_end);
 415                         break;
 416                 }
 417                 if (error)
 418                         continue;
 419
 420                 if (index == bootable)
 421                         table->mbr[DOSPARTOFF + DOSPARTSIZE * index] = 0x80;
 422                 slices |= 1 << index;
 423         }
 424         if ((slices & 3) == 3)
 425                 return;
 426
 427  disable:
 428         table->bootcamp = 0;
 429         gpt_create_pmbr(table, pp);
 430 }
 431
 432 static struct gpt_hdr *
 433 gpt_read_hdr(struct g_part_gpt_table *table, struct g_consumer *cp,
 434     enum gpt_elt elt)
 435 {
 436         struct gpt_hdr *buf, *hdr;
 437         struct g_provider *pp;
 438         quad_t lba, last;
 439         int error;
 440         uint32_t crc, sz;
 441
 442         pp = cp->provider;
 443         last = (pp->mediasize / pp->sectorsize) - 1;
 444         table->state[elt] = GPT_STATE_MISSING;
 445         /*
 446          * If the primary header is valid look for secondary
 447          * header in AlternateLBA, otherwise in the last medium's LBA.
 448          */
 449         if (elt == GPT_ELT_SECHDR) {
 450                 if (table->state[GPT_ELT_PRIHDR] != GPT_STATE_OK)
 451                         table->lba[elt] = last;
 452         } else
 453                 table->lba[elt] = 1;
 454         buf = g_read_data(cp, table->lba[elt] * pp->sectorsize, pp->sectorsize,
 455             &error);
 456         if (buf == NULL)
 457                 return (NULL);
 458         hdr = NULL;
 459         if (memcmp(buf->hdr_sig, GPT_HDR_SIG, sizeof(buf->hdr_sig)) != 0)
 460                 goto fail;
 461
 462         table->state[elt] = GPT_STATE_CORRUPT;
 463         sz = le32toh(buf->hdr_size);
 464         if (sz < 92 || sz > pp->sectorsize)
 465                 goto fail;
 466
 467         hdr = g_malloc(sz, M_WAITOK | M_ZERO);
 468         bcopy(buf, hdr, sz);
 469         hdr->hdr_size = sz;
 470
 471         crc = le32toh(buf->hdr_crc_self);
 472         buf->hdr_crc_self = 0;
 473         if (crc32(buf, sz) != crc)
 474                 goto fail;
 475         hdr->hdr_crc_self = crc;
 476
 477         table->state[elt] = GPT_STATE_INVALID;
 478         hdr->hdr_revision = le32toh(buf->hdr_revision);
 479         if (hdr->hdr_revision < GPT_HDR_REVISION)
 480                 goto fail;
 481         hdr->hdr_lba_self = le64toh(buf->hdr_lba_self);
 482         if (hdr->hdr_lba_self != table->lba[elt])
 483                 goto fail;
 484         hdr->hdr_lba_alt = le64toh(buf->hdr_lba_alt);
 485         if (hdr->hdr_lba_alt == hdr->hdr_lba_self)
 486                 goto fail;
 487         if (hdr->hdr_lba_alt > last && geom_part_check_integrity)
 488                 goto fail;
 489
 490         /* Check the managed area. */
 491         hdr->hdr_lba_start = le64toh(buf->hdr_lba_start);
 492         if (hdr->hdr_lba_start < 2 || hdr->hdr_lba_start >= last)
 493                 goto fail;
 494         hdr->hdr_lba_end = le64toh(buf->hdr_lba_end);
 495         if (hdr->hdr_lba_end < hdr->hdr_lba_start || hdr->hdr_lba_end >= last)
 496                 goto fail;
 497
 498         /* Check the table location and size of the table. */
 499         hdr->hdr_entries = le32toh(buf->hdr_entries);
 500         hdr->hdr_entsz = le32toh(buf->hdr_entsz);
 501         if (hdr->hdr_entries == 0 || hdr->hdr_entsz < 128 ||
 502             (hdr->hdr_entsz & 7) != 0)
 503                 goto fail;
 504         hdr->hdr_lba_table = le64toh(buf->hdr_lba_table);
 505         if (hdr->hdr_lba_table < 2 || hdr->hdr_lba_table >= last)
 506                 goto fail;
 507         if (hdr->hdr_lba_table >= hdr->hdr_lba_start &&
 508             hdr->hdr_lba_table <= hdr->hdr_lba_end)
 509                 goto fail;
 510         lba = hdr->hdr_lba_table +
 511             howmany(hdr->hdr_entries * hdr->hdr_entsz, pp->sectorsize) - 1;
 512         if (lba >= last)
 513                 goto fail;
 514         if (lba >= hdr->hdr_lba_start && lba <= hdr->hdr_lba_end)
 515                 goto fail;
 516
 517         table->state[elt] = GPT_STATE_OK;
 518         le_uuid_dec(&buf->hdr_uuid, &hdr->hdr_uuid);
 519         hdr->hdr_crc_table = le32toh(buf->hdr_crc_table);
 520
 521         /* save LBA for secondary header */
 522         if (elt == GPT_ELT_PRIHDR)
 523                 table->lba[GPT_ELT_SECHDR] = hdr->hdr_lba_alt;
 524
 525         g_free(buf);
 526         return (hdr);
 527
 528  fail:
 529         if (hdr != NULL)
 530                 g_free(hdr);
 531         g_free(buf);
 532         return (NULL);
 533 }
 534
 535 static struct gpt_ent *
 536 gpt_read_tbl(struct g_part_gpt_table *table, struct g_consumer *cp,
 537     enum gpt_elt elt, struct gpt_hdr *hdr)
 538 {
 539         struct g_provider *pp;
 540         struct gpt_ent *ent, *tbl;
 541         char *buf, *p;
 542         unsigned int idx, sectors, tblsz, size;
 543         int error;
 544
 545         if (hdr == NULL)
 546                 return (NULL);
 547
 548         pp = cp->provider;
 549         table->lba[elt] = hdr->hdr_lba_table;
 550
 551         table->state[elt] = GPT_STATE_MISSING;
 552         tblsz = hdr->hdr_entries * hdr->hdr_entsz;
 553         sectors = howmany(tblsz, pp->sectorsize);
 554         buf = g_malloc(sectors * pp->sectorsize, M_WAITOK | M_ZERO);
 555         for (idx = 0; idx < sectors; idx += maxphys / pp->sectorsize) {
 556                 size = (sectors - idx > maxphys / pp->sectorsize) ?  maxphys:
 557                     (sectors - idx) * pp->sectorsize;
 558                 p = g_read_data(cp, (table->lba[elt] + idx) * pp->sectorsize,
 559                     size, &error);
 560                 if (p == NULL) {
 561                         g_free(buf);
 562                         return (NULL);
 563                 }
 564                 bcopy(p, buf + idx * pp->sectorsize, size);
 565                 g_free(p);
 566         }
 567         table->state[elt] = GPT_STATE_CORRUPT;
 568         if (crc32(buf, tblsz) != hdr->hdr_crc_table) {
 569                 g_free(buf);
 570                 return (NULL);
 571         }
 572
 573         table->state[elt] = GPT_STATE_OK;
 574         tbl = g_malloc(hdr->hdr_entries * sizeof(struct gpt_ent),
 575             M_WAITOK | M_ZERO);
 576
 577         for (idx = 0, ent = tbl, p = buf;
 578              idx < hdr->hdr_entries;
 579              idx++, ent++, p += hdr->hdr_entsz) {
 580                 le_uuid_dec(p, &ent->ent_type);
 581                 le_uuid_dec(p + 16, &ent->ent_uuid);
 582                 ent->ent_lba_start = le64dec(p + 32);
 583                 ent->ent_lba_end = le64dec(p + 40);
 584                 ent->ent_attr = le64dec(p + 48);
 585                 /* Keep UTF-16 in little-endian. */
 586                 bcopy(p + 56, ent->ent_name, sizeof(ent->ent_name));
 587         }
 588
 589         g_free(buf);
 590         return (tbl);
 591 }
 592
 593 static int
 594 gpt_matched_hdrs(struct gpt_hdr *pri, struct gpt_hdr *sec)
 595 {
 596
 597         if (pri == NULL || sec == NULL)
 598                 return (0);
 599
 600         if (!EQUUID(&pri->hdr_uuid, &sec->hdr_uuid))
 601                 return (0);
 602         return ((pri->hdr_revision == sec->hdr_revision &&
 603             pri->hdr_size == sec->hdr_size &&
 604             pri->hdr_lba_start == sec->hdr_lba_start &&
 605             pri->hdr_lba_end == sec->hdr_lba_end &&
 606             pri->hdr_entries == sec->hdr_entries &&
 607             pri->hdr_entsz == sec->hdr_entsz &&
 608             pri->hdr_crc_table == sec->hdr_crc_table) ? 1 : 0);
 609 }
 610
 611 static int
 612 gpt_parse_type(const char *type, struct uuid *uuid)
 613 {
 614         struct uuid tmp;
 615         const char *alias;
 616         int error;
 617         struct g_part_uuid_alias *uap;
 618
 619         if (type[0] == '!') {
 620                 error = parse_uuid(type + 1, &tmp);
 621                 if (error)
 622                         return (error);
 623                 if (EQUUID(&tmp, &gpt_uuid_unused))
 624                         return (EINVAL);
 625                 *uuid = tmp;
 626                 return (0);
 627         }
 628         for (uap = &gpt_uuid_alias_match[0]; uap->uuid; uap++) {
 629                 alias = g_part_alias_name(uap->alias);
 630                 if (!strcasecmp(type, alias)) {
 631                         *uuid = *uap->uuid;
 632                         return (0);
 633                 }
 634         }
 635         return (EINVAL);
 636 }
 637
 638 static int
 639 g_part_gpt_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
 640     struct g_part_parms *gpp)
 641 {
 642         struct g_part_gpt_entry *entry;
 643         int error;
 644
 645         entry = (struct g_part_gpt_entry *)baseentry;
 646         error = gpt_parse_type(gpp->gpp_type, &entry->ent.ent_type);
 647         if (error)
 648                 return (error);
 649         kern_uuidgen(&entry->ent.ent_uuid, 1);
 650         entry->ent.ent_lba_start = baseentry->gpe_start;
 651         entry->ent.ent_lba_end = baseentry->gpe_end;
 652         if (baseentry->gpe_deleted) {
 653                 entry->ent.ent_attr = 0;
 654                 bzero(entry->ent.ent_name, sizeof(entry->ent.ent_name));
 655         }
 656         if (gpp->gpp_parms & G_PART_PARM_LABEL)
 657                 g_gpt_utf8_to_utf16(gpp->gpp_label, entry->ent.ent_name,
 658                     sizeof(entry->ent.ent_name) /
 659                     sizeof(entry->ent.ent_name[0]));
 660         return (0);
 661 }
 662
 663 static int
 664 g_part_gpt_bootcode(struct g_part_table *basetable, struct g_part_parms *gpp)
 665 {
 666         struct g_part_gpt_table *table;
 667         size_t codesz;
 668
 669         codesz = DOSPARTOFF;
 670         table = (struct g_part_gpt_table *)basetable;
 671         bzero(table->mbr, codesz);
 672         codesz = MIN(codesz, gpp->gpp_codesize);
 673         if (codesz > 0)
 674                 bcopy(gpp->gpp_codeptr, table->mbr, codesz);
 675         return (0);
 676 }
 677
 678 static int
 679 g_part_gpt_create(struct g_part_table *basetable, struct g_part_parms *gpp)
 680 {
 681         struct g_provider *pp;
 682         struct g_part_gpt_table *table;
 683         size_t tblsz;
 684
 685         /* Our depth should be 0 unless nesting was explicitly enabled. */
 686         if (!allow_nesting && basetable->gpt_depth != 0)
 687                 return (ENXIO);
 688
 689         table = (struct g_part_gpt_table *)basetable;
 690         pp = gpp->gpp_provider;
 691         tblsz = howmany(basetable->gpt_entries * sizeof(struct gpt_ent),
 692             pp->sectorsize);
 693         if (pp->sectorsize < MBRSIZE ||
 694             pp->mediasize < (3 + 2 * tblsz + basetable->gpt_entries) *
 695             pp->sectorsize)
 696                 return (ENOSPC);
 697
 698         gpt_create_pmbr(table, pp);
 699
 700         /* Allocate space for the header */
 701         table->hdr = g_malloc(sizeof(struct gpt_hdr), M_WAITOK | M_ZERO);
 702
 703         bcopy(GPT_HDR_SIG, table->hdr->hdr_sig, sizeof(table->hdr->hdr_sig));
 704         table->hdr->hdr_revision = GPT_HDR_REVISION;
 705         table->hdr->hdr_size = offsetof(struct gpt_hdr, padding);
 706         kern_uuidgen(&table->hdr->hdr_uuid, 1);
 707         table->hdr->hdr_entries = basetable->gpt_entries;
 708         table->hdr->hdr_entsz = sizeof(struct gpt_ent);
 709
 710         g_gpt_set_defaults(basetable, pp);
 711         return (0);
 712 }
 713
 714 static int
 715 g_part_gpt_destroy(struct g_part_table *basetable, struct g_part_parms *gpp)
 716 {
 717         struct g_part_gpt_table *table;
 718         struct g_provider *pp;
 719
 720         table = (struct g_part_gpt_table *)basetable;
 721         pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider;
 722         g_free(table->hdr);
 723         table->hdr = NULL;
 724
 725         /*
 726          * Wipe the first 2 sectors and last one to clear the partitioning.
 727          * Wipe sectors only if they have valid metadata.
 728          */
 729         if (table->state[GPT_ELT_PRIHDR] == GPT_STATE_OK)
 730                 basetable->gpt_smhead |= 3;
 731         if (table->state[GPT_ELT_SECHDR] == GPT_STATE_OK &&
 732             table->lba[GPT_ELT_SECHDR] == pp->mediasize / pp->sectorsize - 1)
 733                 basetable->gpt_smtail |= 1;
 734         return (0);
 735 }
 736
 737 static void
 738 g_part_gpt_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry,
 739     struct sbuf *sb, const char *indent)
 740 {
 741         struct g_part_gpt_entry *entry;
 742
 743         entry = (struct g_part_gpt_entry *)baseentry;
 744         if (indent == NULL) {
 745                 /* conftxt: libdisk compatibility */
 746                 sbuf_cat(sb, " xs GPT xt ");
 747                 sbuf_printf_uuid(sb, &entry->ent.ent_type);
 748         } else if (entry != NULL) {
 749                 /* confxml: partition entry information */
 750                 sbuf_printf(sb, "%s<label>", indent);
 751                 g_gpt_printf_utf16(sb, entry->ent.ent_name,
 752                     sizeof(entry->ent.ent_name) >> 1);
 753                 sbuf_cat(sb, "</label>\n");
 754                 if (entry->ent.ent_attr & GPT_ENT_ATTR_BOOTME)
 755                         sbuf_printf(sb, "%s<attrib>bootme</attrib>\n", indent);
 756                 if (entry->ent.ent_attr & GPT_ENT_ATTR_BOOTONCE) {
 757                         sbuf_printf(sb, "%s<attrib>bootonce</attrib>\n",
 758                             indent);
 759                 }
 760                 if (entry->ent.ent_attr & GPT_ENT_ATTR_BOOTFAILED) {
 761                         sbuf_printf(sb, "%s<attrib>bootfailed</attrib>\n",
 762                             indent);
 763                 }
 764                 sbuf_printf(sb, "%s<rawtype>", indent);
 765                 sbuf_printf_uuid(sb, &entry->ent.ent_type);
 766                 sbuf_cat(sb, "</rawtype>\n");
 767                 sbuf_printf(sb, "%s<rawuuid>", indent);
 768                 sbuf_printf_uuid(sb, &entry->ent.ent_uuid);
 769                 sbuf_cat(sb, "</rawuuid>\n");
 770                 sbuf_printf(sb, "%s<efimedia>", indent);
 771                 sbuf_printf(sb, "HD(%d,GPT,", entry->base.gpe_index);
 772                 sbuf_printf_uuid(sb, &entry->ent.ent_uuid);
 773                 sbuf_printf(sb, ",%#jx,%#jx)", (intmax_t)entry->base.gpe_start,
 774                     (intmax_t)(entry->base.gpe_end - entry->base.gpe_start + 1));
 775                 sbuf_cat(sb, "</efimedia>\n");
 776         } else {
 777                 /* confxml: scheme information */
 778         }
 779 }
 780
 781 static int
 782 g_part_gpt_dumpto(struct g_part_table *table, struct g_part_entry *baseentry)
 783 {
 784         struct g_part_gpt_entry *entry;
 785
 786         entry = (struct g_part_gpt_entry *)baseentry;
 787         return ((EQUUID(&entry->ent.ent_type, &gpt_uuid_freebsd_swap) ||
 788             EQUUID(&entry->ent.ent_type, &gpt_uuid_linux_swap) ||
 789             EQUUID(&entry->ent.ent_type, &gpt_uuid_dfbsd_swap)) ? 1 : 0);
 790 }
 791
 792 static int
 793 g_part_gpt_modify(struct g_part_table *basetable,
 794     struct g_part_entry *baseentry, struct g_part_parms *gpp)
 795 {
 796         struct g_part_gpt_entry *entry;
 797         int error;
 798
 799         entry = (struct g_part_gpt_entry *)baseentry;
 800         if (gpp->gpp_parms & G_PART_PARM_TYPE) {
 801                 error = gpt_parse_type(gpp->gpp_type, &entry->ent.ent_type);
 802                 if (error)
 803                         return (error);
 804         }
 805         if (gpp->gpp_parms & G_PART_PARM_LABEL)
 806                 g_gpt_utf8_to_utf16(gpp->gpp_label, entry->ent.ent_name,
 807                     sizeof(entry->ent.ent_name) /
 808                     sizeof(entry->ent.ent_name[0]));
 809         return (0);
 810 }
 811
 812 static int
 813 g_part_gpt_resize(struct g_part_table *basetable,
 814     struct g_part_entry *baseentry, struct g_part_parms *gpp)
 815 {
 816         struct g_part_gpt_entry *entry;
 817
 818         if (baseentry == NULL)
 819                 return (g_part_gpt_recover(basetable));
 820
 821         entry = (struct g_part_gpt_entry *)baseentry;
 822         baseentry->gpe_end = baseentry->gpe_start + gpp->gpp_size - 1;
 823         entry->ent.ent_lba_end = baseentry->gpe_end;
 824
 825         return (0);
 826 }
 827
 828 static const char *
 829 g_part_gpt_name(struct g_part_table *table, struct g_part_entry *baseentry,
 830     char *buf, size_t bufsz)
 831 {
 832         struct g_part_gpt_entry *entry;
 833         char c;
 834
 835         entry = (struct g_part_gpt_entry *)baseentry;
 836         c = (EQUUID(&entry->ent.ent_type, &gpt_uuid_freebsd)) ? 's' : 'p';
 837         snprintf(buf, bufsz, "%c%d", c, baseentry->gpe_index);
 838         return (buf);
 839 }
 840
 841 static int
 842 g_part_gpt_probe(struct g_part_table *table, struct g_consumer *cp)
 843 {
 844         struct g_provider *pp;
 845         u_char *buf;
 846         int error, index, pri, res;
 847
 848         /* Our depth should be 0 unless nesting was explicitly enabled. */
 849         if (!allow_nesting && table->gpt_depth != 0)
 850                 return (ENXIO);
 851
 852         pp = cp->provider;
 853
 854         /*
 855          * Sanity-check the provider. Since the first sector on the provider
 856          * must be a PMBR and a PMBR is 512 bytes large, the sector size
 857          * must be at least 512 bytes.  Also, since the theoretical minimum
 858          * number of sectors needed by GPT is 6, any medium that has less
 859          * than 6 sectors is never going to be able to hold a GPT. The
 860          * number 6 comes from:
 861          *      1 sector for the PMBR
 862          *      2 sectors for the GPT headers (each 1 sector)
 863          *      2 sectors for the GPT tables (each 1 sector)
 864          *      1 sector for an actual partition
 865          * It's better to catch this pathological case early than behaving
 866          * pathologically later on...
 867          */
 868         if (pp->sectorsize < MBRSIZE || pp->mediasize < 6 * pp->sectorsize)
 869                 return (ENOSPC);
 870
 871         /*
 872          * Check that there's a MBR or a PMBR. If it's a PMBR, we return
 873          * as the highest priority on a match, otherwise we assume some
 874          * GPT-unaware tool has destroyed the GPT by recreating a MBR and
 875          * we really want the MBR scheme to take precedence.
 876          */
 877         buf = g_read_data(cp, 0L, pp->sectorsize, &error);
 878         if (buf == NULL)
 879                 return (error);
 880         res = le16dec(buf + DOSMAGICOFFSET);
 881         pri = G_PART_PROBE_PRI_LOW;
 882         if (res == DOSMAGIC) {
 883                 for (index = 0; index < NDOSPART; index++) {
 884                         if (buf[DOSPARTOFF + DOSPARTSIZE * index + 4] == 0xee)
 885                                 pri = G_PART_PROBE_PRI_HIGH;
 886                 }
 887                 g_free(buf);
 888
 889                 /* Check that there's a primary header. */
 890                 buf = g_read_data(cp, pp->sectorsize, pp->sectorsize, &error);
 891                 if (buf == NULL)
 892                         return (error);
 893                 res = memcmp(buf, GPT_HDR_SIG, 8);
 894                 g_free(buf);
 895                 if (res == 0)
 896                         return (pri);
 897         } else
 898                 g_free(buf);
 899
 900         /* No primary? Check that there's a secondary. */
 901         buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
 902             &error);
 903         if (buf == NULL)
 904                 return (error);
 905         res = memcmp(buf, GPT_HDR_SIG, 8);
 906         g_free(buf);
 907         return ((res == 0) ? pri : ENXIO);
 908 }
 909
 910 static int
 911 g_part_gpt_read(struct g_part_table *basetable, struct g_consumer *cp)
 912 {
 913         struct gpt_hdr *prihdr, *sechdr;
 914         struct gpt_ent *tbl, *pritbl, *sectbl;
 915         struct g_provider *pp;
 916         struct g_part_gpt_table *table;
 917         struct g_part_gpt_entry *entry;
 918         u_char *buf;
 919         uint64_t last;
 920         int error, index;
 921
 922         table = (struct g_part_gpt_table *)basetable;
 923         pp = cp->provider;
 924         last = (pp->mediasize / pp->sectorsize) - 1;
 925
 926         /* Read the PMBR */
 927         buf = g_read_data(cp, 0, pp->sectorsize, &error);
 928         if (buf == NULL)
 929                 return (error);
 930         bcopy(buf, table->mbr, MBRSIZE);
 931         g_free(buf);
 932
 933         /* Read the primary header and table. */
 934         prihdr = gpt_read_hdr(table, cp, GPT_ELT_PRIHDR);
 935         if (table->state[GPT_ELT_PRIHDR] == GPT_STATE_OK) {
 936                 pritbl = gpt_read_tbl(table, cp, GPT_ELT_PRITBL, prihdr);
 937         } else {
 938                 table->state[GPT_ELT_PRITBL] = GPT_STATE_MISSING;
 939                 pritbl = NULL;
 940         }
 941
 942         /* Read the secondary header and table. */
 943         sechdr = gpt_read_hdr(table, cp, GPT_ELT_SECHDR);
 944         if (table->state[GPT_ELT_SECHDR] == GPT_STATE_OK) {
 945                 sectbl = gpt_read_tbl(table, cp, GPT_ELT_SECTBL, sechdr);
 946         } else {
 947                 table->state[GPT_ELT_SECTBL] = GPT_STATE_MISSING;
 948                 sectbl = NULL;
 949         }
 950
 951         /* Fail if we haven't got any good tables at all. */
 952         if (table->state[GPT_ELT_PRITBL] != GPT_STATE_OK &&
 953             table->state[GPT_ELT_SECTBL] != GPT_STATE_OK) {
 954                 printf("GEOM: %s: corrupt or invalid GPT detected.\n",
 955                     pp->name);
 956                 printf("GEOM: %s: GPT rejected -- may not be recoverable.\n",
 957                     pp->name);
 958                 if (prihdr != NULL)
 959                         g_free(prihdr);
 960                 if (pritbl != NULL)
 961                         g_free(pritbl);
 962                 if (sechdr != NULL)
 963                         g_free(sechdr);
 964                 if (sectbl != NULL)
 965                         g_free(sectbl);
 966                 return (EINVAL);
 967         }
 968
 969         /*
 970          * If both headers are good but they disagree with each other,
 971          * then invalidate one. We prefer to keep the primary header,
 972          * unless the primary table is corrupt.
 973          */
 974         if (table->state[GPT_ELT_PRIHDR] == GPT_STATE_OK &&
 975             table->state[GPT_ELT_SECHDR] == GPT_STATE_OK &&
 976             !gpt_matched_hdrs(prihdr, sechdr)) {
 977                 if (table->state[GPT_ELT_PRITBL] == GPT_STATE_OK) {
 978                         table->state[GPT_ELT_SECHDR] = GPT_STATE_INVALID;
 979                         table->state[GPT_ELT_SECTBL] = GPT_STATE_MISSING;
 980                         g_free(sechdr);
 981                         sechdr = NULL;
 982                 } else {
 983                         table->state[GPT_ELT_PRIHDR] = GPT_STATE_INVALID;
 984                         table->state[GPT_ELT_PRITBL] = GPT_STATE_MISSING;
 985                         g_free(prihdr);
 986                         prihdr = NULL;
 987                 }
 988         }
 989
 990         if (table->state[GPT_ELT_PRITBL] != GPT_STATE_OK) {
 991                 printf("GEOM: %s: the primary GPT table is corrupt or "
 992                     "invalid.\n", pp->name);
 993                 printf("GEOM: %s: using the secondary instead -- recovery "
 994                     "strongly advised.\n", pp->name);
 995                 table->hdr = sechdr;
 996                 basetable->gpt_corrupt = 1;
 997                 if (prihdr != NULL)
 998                         g_free(prihdr);
 999                 tbl = sectbl;
1000                 if (pritbl != NULL)
1001                         g_free(pritbl);
1002         } else {
1003                 if (table->state[GPT_ELT_SECTBL] != GPT_STATE_OK) {
1004                         printf("GEOM: %s: the secondary GPT table is corrupt "
1005                             "or invalid.\n", pp->name);
1006                         printf("GEOM: %s: using the primary only -- recovery "
1007                             "suggested.\n", pp->name);
1008                         basetable->gpt_corrupt = 1;
1009                 } else if (table->lba[GPT_ELT_SECHDR] != last) {
1010                         printf( "GEOM: %s: the secondary GPT header is not in "
1011                             "the last LBA.\n", pp->name);
1012                         basetable->gpt_corrupt = 1;
1013                 }
1014                 table->hdr = prihdr;
1015                 if (sechdr != NULL)
1016                         g_free(sechdr);
1017                 tbl = pritbl;
1018                 if (sectbl != NULL)
1019                         g_free(sectbl);
1020         }
1021
1022         basetable->gpt_first = table->hdr->hdr_lba_start;
1023         basetable->gpt_last = table->hdr->hdr_lba_end;
1024         basetable->gpt_entries = table->hdr->hdr_entries;
1025
1026         for (index = basetable->gpt_entries - 1; index >= 0; index--) {
1027                 if (EQUUID(&tbl[index].ent_type, &gpt_uuid_unused))
1028                         continue;
1029                 entry = (struct g_part_gpt_entry *)g_part_new_entry(
1030                     basetable, index + 1, tbl[index].ent_lba_start,
1031                     tbl[index].ent_lba_end);
1032                 entry->ent = tbl[index];
1033         }
1034
1035         g_free(tbl);
1036
1037         /*
1038          * Under Mac OS X, the MBR mirrors the first 4 GPT partitions
1039          * if (and only if) any FAT32 or FAT16 partitions have been
1040          * created. This happens irrespective of whether Boot Camp is
1041          * used/enabled, though it's generally understood to be done
1042          * to support legacy Windows under Boot Camp. We refer to this
1043          * mirroring simply as Boot Camp. We try to detect Boot Camp
1044          * so that we can update the MBR if and when GPT changes have
1045          * been made. Note that we do not enable Boot Camp if not
1046          * previously enabled because we can't assume that we're on a
1047          * Mac alongside Mac OS X.
1048          */
1049         table->bootcamp = gpt_is_bootcamp(table, pp->name);
1050
1051         return (0);
1052 }
1053
1054 static int
1055 g_part_gpt_recover(struct g_part_table *basetable)
1056 {
1057         struct g_part_gpt_table *table;
1058         struct g_provider *pp;
1059
1060         table = (struct g_part_gpt_table *)basetable;
1061         pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider;
1062         gpt_create_pmbr(table, pp);
1063         g_gpt_set_defaults(basetable, pp);
1064         basetable->gpt_corrupt = 0;
1065         return (0);
1066 }
1067
1068 static int
1069 g_part_gpt_setunset(struct g_part_table *basetable,
1070     struct g_part_entry *baseentry, const char *attrib, unsigned int set)
1071 {
1072         struct g_part_gpt_entry *entry;
1073         struct g_part_gpt_table *table;
1074         struct g_provider *pp;
1075         uint8_t *p;
1076         uint64_t attr;
1077         int i;
1078
1079         table = (struct g_part_gpt_table *)basetable;
1080         entry = (struct g_part_gpt_entry *)baseentry;
1081
1082         if (strcasecmp(attrib, "active") == 0) {
1083                 if (table->bootcamp) {
1084                         /* The active flag must be set on a valid entry. */
1085                         if (entry == NULL)
1086                                 return (ENXIO);
1087                         if (baseentry->gpe_index > NDOSPART)
1088                                 return (EINVAL);
1089                         for (i = 0; i < NDOSPART; i++) {
1090                                 p = &table->mbr[DOSPARTOFF + i * DOSPARTSIZE];
1091                                 p[0] = (i == baseentry->gpe_index - 1)
1092                                     ? ((set) ? 0x80 : 0) : 0;
1093                         }
1094                 } else {
1095                         /* The PMBR is marked as active without an entry. */
1096                         if (entry != NULL)
1097                                 return (ENXIO);
1098                         for (i = 0; i < NDOSPART; i++) {
1099                                 p = &table->mbr[DOSPARTOFF + i * DOSPARTSIZE];
1100                                 p[0] = (p[4] == 0xee) ? ((set) ? 0x80 : 0) : 0;
1101                         }
1102                 }
1103                 return (0);
1104         } else if (strcasecmp(attrib, "lenovofix") == 0) {
1105                 /*
1106                  * Write the 0xee GPT entry to slot #1 (2nd slot) in the pMBR.
1107                  * This workaround allows Lenovo X220, T420, T520, etc to boot
1108                  * from GPT Partitions in BIOS mode.
1109                  */
1110
1111                 if (entry != NULL)
1112                         return (ENXIO);
1113
1114                 pp = LIST_FIRST(&basetable->gpt_gp->consumer)->provider;
1115                 bzero(table->mbr + DOSPARTOFF, DOSPARTSIZE * NDOSPART);
1116                 gpt_write_mbr_entry(table->mbr, ((set) ? 1 : 0), 0xee, 1,
1117                     MIN(pp->mediasize / pp->sectorsize - 1, UINT32_MAX));
1118                 return (0);
1119         }
1120
1121         if (entry == NULL)
1122                 return (ENODEV);
1123
1124         attr = 0;
1125         if (strcasecmp(attrib, "bootme") == 0) {
1126                 attr |= GPT_ENT_ATTR_BOOTME;
1127         } else if (strcasecmp(attrib, "bootonce") == 0) {
1128                 attr |= GPT_ENT_ATTR_BOOTONCE;
1129                 if (set)
1130                         attr |= GPT_ENT_ATTR_BOOTME;
1131         } else if (strcasecmp(attrib, "bootfailed") == 0) {
1132                 /*
1133                  * It should only be possible to unset BOOTFAILED, but it might
1134                  * be useful for test purposes to also be able to set it.
1135                  */
1136                 attr |= GPT_ENT_ATTR_BOOTFAILED;
1137         }
1138         if (attr == 0)
1139                 return (EINVAL);
1140
1141         if (set)
1142                 attr = entry->ent.ent_attr | attr;
1143         else
1144                 attr = entry->ent.ent_attr & ~attr;
1145         if (attr != entry->ent.ent_attr) {
1146                 entry->ent.ent_attr = attr;
1147                 if (!baseentry->gpe_created)
1148                         baseentry->gpe_modified = 1;
1149         }
1150         return (0);
1151 }
1152
1153 static const char *
1154 g_part_gpt_type(struct g_part_table *basetable, struct g_part_entry *baseentry,
1155     char *buf, size_t bufsz)
1156 {
1157         struct g_part_gpt_entry *entry;
1158         struct uuid *type;
1159         struct g_part_uuid_alias *uap;
1160
1161         entry = (struct g_part_gpt_entry *)baseentry;
1162         type = &entry->ent.ent_type;
1163         for (uap = &gpt_uuid_alias_match[0]; uap->uuid; uap++)
1164                 if (EQUUID(type, uap->uuid))
1165                         return (g_part_alias_name(uap->alias));
1166         buf[0] = '!';
1167         snprintf_uuid(buf + 1, bufsz - 1, type);
1168
1169         return (buf);
1170 }
1171
1172 static int
1173 g_part_gpt_write(struct g_part_table *basetable, struct g_consumer *cp)
1174 {
1175         unsigned char *buf, *bp;
1176         struct g_provider *pp;
1177         struct g_part_entry *baseentry;
1178         struct g_part_gpt_entry *entry;
1179         struct g_part_gpt_table *table;
1180         size_t tblsz;
1181         uint32_t crc;
1182         int error, index;
1183
1184         pp = cp->provider;
1185         table = (struct g_part_gpt_table *)basetable;
1186         tblsz = howmany(table->hdr->hdr_entries * table->hdr->hdr_entsz,
1187             pp->sectorsize);
1188
1189         /* Reconstruct the MBR from the GPT if under Boot Camp. */
1190         if (table->bootcamp)
1191                 gpt_update_bootcamp(basetable, pp);
1192
1193         /* Write the PMBR */
1194         buf = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
1195         bcopy(table->mbr, buf, MBRSIZE);
1196         error = g_write_data(cp, 0, buf, pp->sectorsize);
1197         g_free(buf);
1198         if (error)
1199                 return (error);
1200
1201         /* Allocate space for the header and entries. */
1202         buf = g_malloc((tblsz + 1) * pp->sectorsize, M_WAITOK | M_ZERO);
1203
1204         memcpy(buf, table->hdr->hdr_sig, sizeof(table->hdr->hdr_sig));
1205         le32enc(buf + 8, table->hdr->hdr_revision);
1206         le32enc(buf + 12, table->hdr->hdr_size);
1207         le64enc(buf + 40, table->hdr->hdr_lba_start);
1208         le64enc(buf + 48, table->hdr->hdr_lba_end);
1209         le_uuid_enc(buf + 56, &table->hdr->hdr_uuid);
1210         le32enc(buf + 80, table->hdr->hdr_entries);
1211         le32enc(buf + 84, table->hdr->hdr_entsz);
1212
1213         LIST_FOREACH(baseentry, &basetable->gpt_entry, gpe_entry) {
1214                 if (baseentry->gpe_deleted)
1215                         continue;
1216                 entry = (struct g_part_gpt_entry *)baseentry;
1217                 index = baseentry->gpe_index - 1;
1218                 bp = buf + pp->sectorsize + table->hdr->hdr_entsz * index;
1219                 le_uuid_enc(bp, &entry->ent.ent_type);
1220                 le_uuid_enc(bp + 16, &entry->ent.ent_uuid);
1221                 le64enc(bp + 32, entry->ent.ent_lba_start);
1222                 le64enc(bp + 40, entry->ent.ent_lba_end);
1223                 le64enc(bp + 48, entry->ent.ent_attr);
1224                 memcpy(bp + 56, entry->ent.ent_name,
1225                     sizeof(entry->ent.ent_name));
1226         }
1227
1228         crc = crc32(buf + pp->sectorsize,
1229             table->hdr->hdr_entries * table->hdr->hdr_entsz);
1230         le32enc(buf + 88, crc);
1231
1232         /* Write primary meta-data. */
1233         le32enc(buf + 16, 0);   /* hdr_crc_self. */
1234         le64enc(buf + 24, table->lba[GPT_ELT_PRIHDR]);  /* hdr_lba_self. */
1235         le64enc(buf + 32, table->lba[GPT_ELT_SECHDR]);  /* hdr_lba_alt. */
1236         le64enc(buf + 72, table->lba[GPT_ELT_PRITBL]);  /* hdr_lba_table. */
1237         crc = crc32(buf, table->hdr->hdr_size);
1238         le32enc(buf + 16, crc);
1239
1240         for (index = 0; index < tblsz; index += maxphys / pp->sectorsize) {
1241                 error = g_write_data(cp,
1242                     (table->lba[GPT_ELT_PRITBL] + index) * pp->sectorsize,
1243                     buf + (index + 1) * pp->sectorsize,
1244                     (tblsz - index > maxphys / pp->sectorsize) ? maxphys :
1245                     (tblsz - index) * pp->sectorsize);
1246                 if (error)
1247                         goto out;
1248         }
1249         error = g_write_data(cp, table->lba[GPT_ELT_PRIHDR] * pp->sectorsize,
1250             buf, pp->sectorsize);
1251         if (error)
1252                 goto out;
1253
1254         /* Write secondary meta-data. */
1255         le32enc(buf + 16, 0);   /* hdr_crc_self. */
1256         le64enc(buf + 24, table->lba[GPT_ELT_SECHDR]);  /* hdr_lba_self. */
1257         le64enc(buf + 32, table->lba[GPT_ELT_PRIHDR]);  /* hdr_lba_alt. */
1258         le64enc(buf + 72, table->lba[GPT_ELT_SECTBL]);  /* hdr_lba_table. */
1259         crc = crc32(buf, table->hdr->hdr_size);
1260         le32enc(buf + 16, crc);
1261
1262         for (index = 0; index < tblsz; index += maxphys / pp->sectorsize) {
1263                 error = g_write_data(cp,
1264                     (table->lba[GPT_ELT_SECTBL] + index) * pp->sectorsize,
1265                     buf + (index + 1) * pp->sectorsize,
1266                     (tblsz - index > maxphys / pp->sectorsize) ? maxphys :
1267                     (tblsz - index) * pp->sectorsize);
1268                 if (error)
1269                         goto out;
1270         }
1271         error = g_write_data(cp, table->lba[GPT_ELT_SECHDR] * pp->sectorsize,
1272             buf, pp->sectorsize);
1273
1274  out:
1275         g_free(buf);
1276         return (error);
1277 }
1278
1279 static void
1280 g_gpt_set_defaults(struct g_part_table *basetable, struct g_provider *pp)
1281 {
1282         struct g_part_entry *baseentry;
1283         struct g_part_gpt_entry *entry;
1284         struct g_part_gpt_table *table;
1285         quad_t start, end, min, max;
1286         quad_t lba, last;
1287         size_t spb, tblsz;
1288
1289         table = (struct g_part_gpt_table *)basetable;
1290         last = pp->mediasize / pp->sectorsize - 1;
1291         tblsz = howmany(basetable->gpt_entries * sizeof(struct gpt_ent),
1292             pp->sectorsize);
1293
1294         table->lba[GPT_ELT_PRIHDR] = 1;
1295         table->lba[GPT_ELT_PRITBL] = 2;
1296         table->lba[GPT_ELT_SECHDR] = last;
1297         table->lba[GPT_ELT_SECTBL] = last - tblsz;
1298         table->state[GPT_ELT_PRIHDR] = GPT_STATE_OK;
1299         table->state[GPT_ELT_PRITBL] = GPT_STATE_OK;
1300         table->state[GPT_ELT_SECHDR] = GPT_STATE_OK;
1301         table->state[GPT_ELT_SECTBL] = GPT_STATE_OK;
1302
1303         max = start = 2 + tblsz;
1304         min = end = last - tblsz - 1;
1305         LIST_FOREACH(baseentry, &basetable->gpt_entry, gpe_entry) {
1306                 if (baseentry->gpe_deleted)
1307                         continue;
1308                 entry = (struct g_part_gpt_entry *)baseentry;
1309                 if (entry->ent.ent_lba_start < min)
1310                         min = entry->ent.ent_lba_start;
1311                 if (entry->ent.ent_lba_end > max)
1312                         max = entry->ent.ent_lba_end;
1313         }
1314         spb = 4096 / pp->sectorsize;
1315         if (spb > 1) {
1316                 lba = start + ((start % spb) ? spb - start % spb : 0);
1317                 if (lba <= min)
1318                         start = lba;
1319                 lba = end - (end + 1) % spb;
1320                 if (max <= lba)
1321                         end = lba;
1322         }
1323         table->hdr->hdr_lba_start = start;
1324         table->hdr->hdr_lba_end = end;
1325
1326         basetable->gpt_first = start;
1327         basetable->gpt_last = end;
1328 }
1329
1330 static void
1331 g_gpt_printf_utf16(struct sbuf *sb, uint16_t *str, size_t len)
1332 {
1333         u_int bo;
1334         uint32_t ch;
1335         uint16_t c;
1336
1337         bo = LITTLE_ENDIAN;     /* GPT is little-endian */
1338         while (len > 0 && *str != 0) {
1339                 ch = (bo == BIG_ENDIAN) ? be16toh(*str) : le16toh(*str);
1340                 str++, len--;
1341                 if ((ch & 0xf800) == 0xd800) {
1342                         if (len > 0) {
1343                                 c = (bo == BIG_ENDIAN) ? be16toh(*str)
1344                                     : le16toh(*str);
1345                                 str++, len--;
1346                         } else
1347                                 c = 0xfffd;
1348                         if ((ch & 0x400) == 0 && (c & 0xfc00) == 0xdc00) {
1349                                 ch = ((ch & 0x3ff) << 10) + (c & 0x3ff);
1350                                 ch += 0x10000;
1351                         } else
1352                                 ch = 0xfffd;
1353                 } else if (ch == 0xfffe) { /* BOM (U+FEFF) swapped. */
1354                         bo = (bo == BIG_ENDIAN) ? LITTLE_ENDIAN : BIG_ENDIAN;
1355                         continue;
1356                 } else if (ch == 0xfeff) /* BOM (U+FEFF) unswapped. */
1357                         continue;
1358
1359                 /* Write the Unicode character in UTF-8 */
1360                 if (ch < 0x80)
1361                         g_conf_printf_escaped(sb, "%c", ch);
1362                 else if (ch < 0x800)
1363                         g_conf_printf_escaped(sb, "%c%c", 0xc0 | (ch >> 6),
1364                             0x80 | (ch & 0x3f));
1365                 else if (ch < 0x10000)
1366                         g_conf_printf_escaped(sb, "%c%c%c", 0xe0 | (ch >> 12),
1367                             0x80 | ((ch >> 6) & 0x3f), 0x80 | (ch & 0x3f));
1368                 else if (ch < 0x200000)
1369                         g_conf_printf_escaped(sb, "%c%c%c%c", 0xf0 |
1370                             (ch >> 18), 0x80 | ((ch >> 12) & 0x3f),
1371                             0x80 | ((ch >> 6) & 0x3f), 0x80 | (ch & 0x3f));
1372         }
1373 }
1374
1375 static void
1376 g_gpt_utf8_to_utf16(const uint8_t *s8, uint16_t *s16, size_t s16len)
1377 {
1378         size_t s16idx, s8idx;
1379         uint32_t utfchar;
1380         unsigned int c, utfbytes;
1381
1382         s8idx = s16idx = 0;
1383         utfchar = 0;
1384         utfbytes = 0;
1385         bzero(s16, s16len << 1);
1386         while (s8[s8idx] != 0 && s16idx < s16len) {
1387                 c = s8[s8idx++];
1388                 if ((c & 0xc0) != 0x80) {
1389                         /* Initial characters. */
1390                         if (utfbytes != 0) {
1391                                 /* Incomplete encoding of previous char. */
1392                                 s16[s16idx++] = htole16(0xfffd);
1393                         }
1394                         if ((c & 0xf8) == 0xf0) {
1395                                 utfchar = c & 0x07;
1396                                 utfbytes = 3;
1397                         } else if ((c & 0xf0) == 0xe0) {
1398                                 utfchar = c & 0x0f;
1399                                 utfbytes = 2;
1400                         } else if ((c & 0xe0) == 0xc0) {
1401                                 utfchar = c & 0x1f;
1402                                 utfbytes = 1;
1403                         } else {
1404                                 utfchar = c & 0x7f;
1405                                 utfbytes = 0;
1406                         }
1407                 } else {
1408                         /* Followup characters. */
1409                         if (utfbytes > 0) {
1410                                 utfchar = (utfchar << 6) + (c & 0x3f);
1411                                 utfbytes--;
1412                         } else if (utfbytes == 0)
1413                                 utfbytes = ~0;
1414                 }
1415                 /*
1416                  * Write the complete Unicode character as UTF-16 when we
1417                  * have all the UTF-8 charactars collected.
1418                  */
1419                 if (utfbytes == 0) {
1420                         /*
1421                          * If we need to write 2 UTF-16 characters, but
1422                          * we only have room for 1, then we truncate the
1423                          * string by writing a 0 instead.
1424                          */
1425                         if (utfchar >= 0x10000 && s16idx < s16len - 1) {
1426                                 s16[s16idx++] =
1427                                     htole16(0xd800 | ((utfchar >> 10) - 0x40));
1428                                 s16[s16idx++] =
1429                                     htole16(0xdc00 | (utfchar & 0x3ff));
1430                         } else
1431                                 s16[s16idx++] = (utfchar >= 0x10000) ? 0 :
1432                                     htole16(utfchar);
1433                 }
1434         }
1435         /*
1436          * If our input string was truncated, append an invalid encoding
1437          * character to the output string.
1438          */
1439         if (utfbytes != 0 && s16idx < s16len)
1440                 s16[s16idx++] = htole16(0xfffd);
1441 }