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/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/gpt.h> 32 33 #ifndef LITTLE_ENDIAN 34 #error gpt.c works only for little endian architectures 35 #endif 36 37 #include "stand.h" 38 #include "crc32.h" 39 #include "drv.h" 40 #include "gpt.h" 41 42 static struct gpt_hdr hdr_primary, hdr_backup, *gpthdr; 43 static uint64_t hdr_primary_lba, hdr_backup_lba; 44 static struct gpt_ent table_primary[MAXTBLENTS], table_backup[MAXTBLENTS]; 45 static struct gpt_ent *gpttable; 46 static int curent, bootonce; 47 48 /* 49 * Buffer below 64kB passed on gptread(), which can hold at least 50 * one sector of data (512 bytes). 51 */ 52 static char *secbuf; 53 54 static void 55 gptupdate(const char *which, struct dsk *dskp, struct gpt_hdr *hdr, 56 struct gpt_ent *table) 57 { 58 int entries_per_sec, firstent; 59 daddr_t slba; 60 61 /* 62 * We need to update the following for both primary and backup GPT: 63 * 1. Sector on disk that contains current partition. 64 * 2. Partition table checksum. 65 * 3. Header checksum. 66 * 4. Header on disk. 67 */ 68 69 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz; 70 slba = curent / entries_per_sec; 71 firstent = slba * entries_per_sec; 72 bcopy(&table[firstent], secbuf, DEV_BSIZE); 73 slba += hdr->hdr_lba_table; 74 if (drvwrite(dskp, secbuf, slba, 1)) { 75 printf("%s: unable to update %s GPT partition table\n", 76 BOOTPROG, which); 77 return; 78 } 79 hdr->hdr_crc_table = crc32(table, hdr->hdr_entries * hdr->hdr_entsz); 80 hdr->hdr_crc_self = 0; 81 hdr->hdr_crc_self = crc32(hdr, 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 = 0; 202 if (crc32(hdr, hdr->hdr_size) != crc) { 203 printf("%s: %s GPT header checksum mismatch\n", BOOTPROG, 204 which); 205 return (-1); 206 } 207 hdr->hdr_crc_self = crc; 208 return (0); 209 } 210 211 void 212 gptbootfailed(struct dsk *dskp) 213 { 214 215 if (!(gpttable[curent].ent_attr & GPT_ENT_ATTR_BOOTONCE)) 216 return; 217 218 if (hdr_primary_lba > 0) { 219 table_primary[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE; 220 table_primary[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED; 221 gptupdate("primary", dskp, &hdr_primary, table_primary); 222 } 223 if (hdr_backup_lba > 0) { 224 table_backup[curent].ent_attr &= ~GPT_ENT_ATTR_BOOTONCE; 225 table_backup[curent].ent_attr |= GPT_ENT_ATTR_BOOTFAILED; 226 gptupdate("backup", dskp, &hdr_backup, table_backup); 227 } 228 } 229 230 static void 231 gptbootconv(const char *which, struct dsk *dskp, struct gpt_hdr *hdr, 232 struct gpt_ent *table) 233 { 234 struct gpt_ent *ent; 235 daddr_t slba; 236 int table_updated, sector_updated; 237 int entries_per_sec, nent, part; 238 239 table_updated = 0; 240 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz; 241 for (nent = 0, slba = hdr->hdr_lba_table; 242 slba < hdr->hdr_lba_table + hdr->hdr_entries / entries_per_sec; 243 slba++, nent += entries_per_sec) { 244 sector_updated = 0; 245 for (part = 0; part < entries_per_sec; part++) { 246 ent = &table[nent + part]; 247 if ((ent->ent_attr & (GPT_ENT_ATTR_BOOTME | 248 GPT_ENT_ATTR_BOOTONCE | 249 GPT_ENT_ATTR_BOOTFAILED)) != 250 GPT_ENT_ATTR_BOOTONCE) { 251 continue; 252 } 253 ent->ent_attr &= ~GPT_ENT_ATTR_BOOTONCE; 254 ent->ent_attr |= GPT_ENT_ATTR_BOOTFAILED; 255 table_updated = 1; 256 sector_updated = 1; 257 } 258 if (!sector_updated) 259 continue; 260 bcopy(&table[nent], secbuf, DEV_BSIZE); 261 if (drvwrite(dskp, secbuf, slba, 1)) { 262 printf("%s: unable to update %s GPT partition table\n", 263 BOOTPROG, which); 264 } 265 } 266 if (!table_updated) 267 return; 268 hdr->hdr_crc_table = crc32(table, hdr->hdr_entries * hdr->hdr_entsz); 269 hdr->hdr_crc_self = 0; 270 hdr->hdr_crc_self = crc32(hdr, hdr->hdr_size); 271 bzero(secbuf, DEV_BSIZE); 272 bcopy(hdr, secbuf, hdr->hdr_size); 273 if (drvwrite(dskp, secbuf, hdr->hdr_lba_self, 1)) 274 printf("%s: unable to update %s GPT header\n", BOOTPROG, which); 275 } 276 277 static int 278 gptread_table(const char *which, const uuid_t *uuid, struct dsk *dskp, 279 struct gpt_hdr *hdr, struct gpt_ent *table) 280 { 281 struct gpt_ent *ent; 282 int entries_per_sec; 283 int part, nent; 284 daddr_t slba; 285 286 if (hdr->hdr_entries == 0) 287 return (0); 288 289 entries_per_sec = DEV_BSIZE / hdr->hdr_entsz; 290 slba = hdr->hdr_lba_table; 291 nent = 0; 292 for (;;) { 293 if (drvread(dskp, secbuf, slba, 1)) { 294 printf("%s: unable to read %s GPT partition table\n", 295 BOOTPROG, which); 296 return (-1); 297 } 298 ent = (struct gpt_ent *)secbuf; 299 for (part = 0; part < entries_per_sec; part++, ent++) { 300 bcopy(ent, &table[nent], sizeof(table[nent])); 301 if (++nent >= hdr->hdr_entries) 302 break; 303 } 304 if (nent >= hdr->hdr_entries) 305 break; 306 slba++; 307 } 308 if (crc32(table, nent * hdr->hdr_entsz) != hdr->hdr_crc_table) { 309 printf("%s: %s GPT table checksum mismatch\n", BOOTPROG, which); 310 return (-1); 311 } 312 return (0); 313 } 314 315 int 316 gptread(const uuid_t *uuid, struct dsk *dskp, char *buf) 317 { 318 uint64_t altlba; 319 320 /* 321 * Read and verify both GPT headers: primary and backup. 322 */ 323 324 secbuf = buf; 325 hdr_primary_lba = hdr_backup_lba = 0; 326 curent = -1; 327 bootonce = 1; 328 dskp->start = 0; 329 330 if (gptread_hdr("primary", dskp, &hdr_primary, 1) == 0 && 331 gptread_table("primary", uuid, dskp, &hdr_primary, 332 table_primary) == 0) { 333 hdr_primary_lba = hdr_primary.hdr_lba_self; 334 gpthdr = &hdr_primary; 335 gpttable = table_primary; 336 } 337 338 if (hdr_primary_lba > 0) { 339 /* 340 * If primary header is valid, we can get backup 341 * header location from there. 342 */ 343 altlba = hdr_primary.hdr_lba_alt; 344 } else { 345 altlba = drvsize(dskp); 346 if (altlba > 0) 347 altlba--; 348 } 349 if (altlba == 0) 350 printf("%s: unable to locate backup GPT header\n", BOOTPROG); 351 else if (gptread_hdr("backup", dskp, &hdr_backup, altlba) == 0 && 352 gptread_table("backup", uuid, dskp, &hdr_backup, 353 table_backup) == 0) { 354 hdr_backup_lba = hdr_backup.hdr_lba_self; 355 if (hdr_primary_lba == 0) { 356 gpthdr = &hdr_backup; 357 gpttable = table_backup; 358 printf("%s: using backup GPT\n", BOOTPROG); 359 } 360 } 361 362 /* 363 * Convert all BOOTONCE without BOOTME flags into BOOTFAILED. 364 * BOOTONCE without BOOTME means that we tried to boot from it, 365 * but failed after leaving gptboot and machine was rebooted. 366 * We don't want to leave partitions marked as BOOTONCE only, 367 * because when we boot successfully start-up scripts should 368 * find at most one partition with only BOOTONCE flag and this 369 * will mean that we booted from that partition. 370 */ 371 if (hdr_primary_lba != 0) 372 gptbootconv("primary", dskp, &hdr_primary, table_primary); 373 if (hdr_backup_lba != 0) 374 gptbootconv("backup", dskp, &hdr_backup, table_backup); 375 376 if (hdr_primary_lba == 0 && hdr_backup_lba == 0) 377 return (-1); 378 return (0); 379 } 380