1 /*- 2 * Copyright (c) 2010 Pawel Jakub Dawidek <pjd@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/param.h> 28 #include <sys/gpt.h> 29 30 #ifndef LITTLE_ENDIAN 31 #error gpt.c works only for little endian architectures 32 #endif 33 34 #include "stand.h" 35 #include "zlib.h" 36 #include "drv.h" 37 #include "gpt.h" 38 39 static struct gpt_hdr hdr_primary, hdr_backup, *gpthdr; 40 static uint64_t hdr_primary_lba, hdr_backup_lba; 41 static struct gpt_ent table_primary[MAXTBLENTS], table_backup[MAXTBLENTS]; 42 static struct gpt_ent *gpttable; 43 static int curent, bootonce; 44 45 /* 46 * Buffer below 64kB passed on gptread(), which can hold at least 47 * one sector of data (512 bytes). 48 */ 49 static char *secbuf; 50 51 static void 52 gptupdate(const char *which, struct dsk *dskp, struct gpt_hdr *hdr, 53 struct gpt_ent *table) 54 { 55 int entries_per_sec, firstent; 56 daddr_t slba; 57 58 /* 59 * We need to update the following for both primary and backup GPT: 60 * 1. Sector on disk that contains current partition. 61 * 2. Partition table checksum. 62 * 3. Header checksum. 63 * 4. Header on disk. 64 */ 65 66 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz; 67 slba = curent / entries_per_sec; 68 firstent = slba * entries_per_sec; 69 bcopy(&table[firstent], secbuf, DEV_BSIZE); 70 slba += hdr->hdr_lba_table; 71 if (drvwrite(dskp, secbuf, slba, 1)) { 72 printf("%s: unable to update %s GPT partition table\n", 73 BOOTPROG, which); 74 return; 75 } 76 hdr->hdr_crc_table = crc32(0, Z_NULL, 0); 77 hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, (const Bytef *)table, 78 hdr->hdr_entries * hdr->hdr_entsz); 79 hdr->hdr_crc_self = crc32(0, Z_NULL, 0); 80 hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, (const Bytef *)hdr, 81 hdr->hdr_size); 82 bzero(secbuf, DEV_BSIZE); 83 bcopy(hdr, secbuf, hdr->hdr_size); 84 if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1)) { 85 printf("%s: unable to update %s GPT header\n", BOOTPROG, which); 86 return; 87 } 88 } 89 90 int 91 gptfind(const uuid_t *uuid, struct dsk *dskp, int part) 92 { 93 struct gpt_ent *ent; 94 int firsttry; 95 96 if (part >= 0) { 97 if (part == 0 || part > gpthdr->hdr_entries) { 98 printf("%s: invalid partition index\n", BOOTPROG); 99 return (-1); 100 } 101 ent = &gpttable[part - 1]; 102 if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0) { 103 printf("%s: specified partition is not UFS\n", 104 BOOTPROG); 105 return (-1); 106 } 107 curent = part - 1; 108 goto found; 109 } 110 111 firsttry = (curent == -1); 112 curent++; 113 if (curent >= gpthdr->hdr_entries) { 114 curent = gpthdr->hdr_entries; 115 return (-1); 116 } 117 if (bootonce) { 118 /* 119 * First look for partition with both GPT_ENT_ATTR_BOOTME and 120 * GPT_ENT_ATTR_BOOTONCE flags. 121 */ 122 for (; curent < gpthdr->hdr_entries; curent++) { 123 ent = &gpttable[curent]; 124 if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0) 125 continue; 126 if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTME)) 127 continue; 128 if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTONCE)) 129 continue; 130 /* Ok, found one. */ 131 goto found; 132 } 133 bootonce = 0; 134 curent = 0; 135 } 136 for (; curent < gpthdr->hdr_entries; curent++) { 137 ent = &gpttable[curent]; 138 if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0) 139 continue; 140 if (!(ent->ent_attr & GPT_ENT_ATTR_BOOTME)) 141 continue; 142 if (ent->ent_attr & GPT_ENT_ATTR_BOOTONCE) 143 continue; 144 /* Ok, found one. */ 145 goto found; 146 } 147 if (firsttry) { 148 /* 149 * No partition with BOOTME flag was found, try to boot from 150 * first UFS partition. 151 */ 152 for (curent = 0; curent < gpthdr->hdr_entries; curent++) { 153 ent = &gpttable[curent]; 154 if (bcmp(&ent->ent_type, uuid, sizeof(uuid_t)) != 0) 155 continue; 156 /* Ok, found one. */ 157 goto found; 158 } 159 } 160 return (-1); 161 found: 162 dskp->part = curent + 1; 163 ent = &gpttable[curent]; 164 dskp->start = ent->ent_lba_start; 165 if (ent->ent_attr & GPT_ENT_ATTR_BOOTONCE) { 166 /* 167 * Clear BOOTME, but leave BOOTONCE set before trying to 168 * boot from this partition. 169 */ 170 if (hdr_primary_lba > 0) { 171 table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTME; 172 gptupdate("primary", dskp, &hdr_primary, table_primary); 173 } 174 if (hdr_backup_lba > 0) { 175 table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTME; 176 gptupdate("backup", dskp, &hdr_backup, table_backup); 177 } 178 } 179 return (0); 180 } 181 182 static int 183 gptread_hdr(const char *which, struct dsk *dskp, struct gpt_hdr *hdr, 184 uint64_t hdrlba) 185 { 186 uint32_t crc; 187 188 if (drvread(dskp, secbuf, hdrlba, 1)) { 189 printf("%s: unable to read %s GPT header\n", BOOTPROG, which); 190 return (-1); 191 } 192 bcopy(secbuf, hdr, sizeof(*hdr)); 193 if (bcmp(hdr->hdr_sig, GPT_HDR_SIG, sizeof(hdr->hdr_sig)) != 0 || 194 hdr->hdr_lba_self != hdrlba || hdr->hdr_revision < 0x00010000 || 195 hdr->hdr_entsz < sizeof(struct gpt_ent) || 196 hdr->hdr_entries > MAXTBLENTS || DEV_BSIZE % hdr->hdr_entsz != 0) { 197 printf("%s: invalid %s GPT header\n", BOOTPROG, which); 198 return (-1); 199 } 200 crc = hdr->hdr_crc_self; 201 hdr->hdr_crc_self = crc32(0, Z_NULL, 0); 202 if (crc32(hdr->hdr_crc_self, (const Bytef *)hdr, hdr->hdr_size) != 203 crc) { 204 printf("%s: %s GPT header checksum mismatch\n", BOOTPROG, 205 which); 206 return (-1); 207 } 208 hdr->hdr_crc_self = crc; 209 return (0); 210 } 211 212 void 213 gptbootfailed(struct dsk *dskp) 214 { 215 216 if (!(gpttable[curent].ent_attr & GPT_ENT_ATTR_BOOTONCE)) 217 return; 218 219 if (hdr_primary_lba > 0) { 220 table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE; 221 table_primary[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED; 222 gptupdate("primary", dskp, &hdr_primary, table_primary); 223 } 224 if (hdr_backup_lba > 0) { 225 table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE; 226 table_backup[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED; 227 gptupdate("backup", dskp, &hdr_backup, table_backup); 228 } 229 } 230 231 static void 232 gptbootconv(const char *which, struct dsk *dskp, struct gpt_hdr *hdr, 233 struct gpt_ent *table) 234 { 235 struct gpt_ent *ent; 236 daddr_t slba; 237 int table_updated, sector_updated; 238 int entries_per_sec, nent, part; 239 240 table_updated = 0; 241 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz; 242 for (nent = 0, slba = hdr->hdr_lba_table; 243 slba < hdr->hdr_lba_table + hdr->hdr_entries / entries_per_sec; 244 slba++, nent += entries_per_sec) { 245 sector_updated = 0; 246 for (part = 0; part < entries_per_sec; part++) { 247 ent = &table[nent + part]; 248 if ((ent->ent_attr & (GPT_ENT_ATTR_BOOTME | 249 GPT_ENT_ATTR_BOOTONCE | 250 GPT_ENT_ATTR_BOOTFAILED)) != 251 GPT_ENT_ATTR_BOOTONCE) { 252 continue; 253 } 254 ent->ent_attr &= ~GPT_ENT_ATTR_BOOTONCE; 255 ent->ent_attr |= GPT_ENT_ATTR_BOOTFAILED; 256 table_updated = 1; 257 sector_updated = 1; 258 } 259 if (!sector_updated) 260 continue; 261 bcopy(&table[nent], secbuf, DEV_BSIZE); 262 if (drvwrite(dskp, secbuf, slba, 1)) { 263 printf("%s: unable to update %s GPT partition table\n", 264 BOOTPROG, which); 265 } 266 } 267 if (!table_updated) 268 return; 269 hdr->hdr_crc_table = crc32(0, Z_NULL, 0); 270 hdr->hdr_crc_table = crc32(hdr->hdr_crc_table, (const Bytef *)table, 271 hdr->hdr_entries * hdr->hdr_entsz); 272 hdr->hdr_crc_self = crc32(0, Z_NULL, 0); 273 hdr->hdr_crc_self = crc32(hdr->hdr_crc_self, (const Bytef *)hdr, 274 hdr->hdr_size); 275 bzero(secbuf, DEV_BSIZE); 276 bcopy(hdr, secbuf, hdr->hdr_size); 277 if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1)) 278 printf("%s: unable to update %s GPT header\n", BOOTPROG, which); 279 } 280 281 static int 282 gptread_table(const char *which, struct dsk *dskp, struct gpt_hdr *hdr, 283 struct gpt_ent *table) 284 { 285 struct gpt_ent *ent; 286 int entries_per_sec; 287 int part, nent; 288 daddr_t slba; 289 290 if (hdr->hdr_entries == 0) 291 return (0); 292 293 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz; 294 slba = hdr->hdr_lba_table; 295 nent = 0; 296 for (;;) { 297 if (drvread(dskp, secbuf, slba, 1)) { 298 printf("%s: unable to read %s GPT partition table\n", 299 BOOTPROG, which); 300 return (-1); 301 } 302 ent = (struct gpt_ent *)secbuf; 303 for (part = 0; part < entries_per_sec; part++, ent++) { 304 bcopy(ent, &table[nent], sizeof(table[nent])); 305 if (++nent >= hdr->hdr_entries) 306 break; 307 } 308 if (nent >= hdr->hdr_entries) 309 break; 310 slba++; 311 } 312 if (crc32(0, (const Bytef *)table, nent * hdr->hdr_entsz) != 313 hdr->hdr_crc_table) { 314 printf("%s: %s GPT table checksum mismatch\n", BOOTPROG, which); 315 return (-1); 316 } 317 return (0); 318 } 319 320 int 321 gptread(struct dsk *dskp, char *buf) 322 { 323 uint64_t altlba; 324 325 /* 326 * Read and verify both GPT headers: primary and backup. 327 */ 328 329 secbuf = buf; 330 hdr_primary_lba = hdr_backup_lba = 0; 331 curent = -1; 332 bootonce = 1; 333 dskp->start = 0; 334 335 if (gptread_hdr("primary", dskp, &hdr_primary, 1) == 0 && 336 gptread_table("primary", dskp, &hdr_primary, table_primary) == 0) { 337 hdr_primary_lba = hdr_primary.hdr_lba_self; 338 gpthdr = &hdr_primary; 339 gpttable = table_primary; 340 } 341 342 if (hdr_primary_lba > 0) { 343 /* 344 * If primary header is valid, we can get backup 345 * header location from there. 346 */ 347 altlba = hdr_primary.hdr_lba_alt; 348 } else { 349 altlba = drvsize(dskp); 350 if (altlba > 0) 351 altlba--; 352 } 353 if (altlba == 0) 354 printf("%s: unable to locate backup GPT header\n", BOOTPROG); 355 else if (gptread_hdr("backup", dskp, &hdr_backup, altlba) == 0 && 356 gptread_table("backup", dskp, &hdr_backup, table_backup) == 0) { 357 hdr_backup_lba = hdr_backup.hdr_lba_self; 358 if (hdr_primary_lba == 0) { 359 gpthdr = &hdr_backup; 360 gpttable = table_backup; 361 printf("%s: using backup GPT\n", BOOTPROG); 362 } 363 } 364 365 /* 366 * Convert all BOOTONCE without BOOTME flags into BOOTFAILED. 367 * BOOTONCE without BOOTME means that we tried to boot from it, 368 * but failed after leaving gptboot and machine was rebooted. 369 * We don't want to leave partitions marked as BOOTONCE only, 370 * because when we boot successfully start-up scripts should 371 * find at most one partition with only BOOTONCE flag and this 372 * will mean that we booted from that partition. 373 */ 374 if (hdr_primary_lba != 0) 375 gptbootconv("primary", dskp, &hdr_primary, table_primary); 376 if (hdr_backup_lba != 0) 377 gptbootconv("backup", dskp, &hdr_backup, table_backup); 378 379 if (hdr_primary_lba == 0 && hdr_backup_lba == 0) 380 return (-1); 381 return (0); 382 } 383