From 6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 18:29:51 +0200 Subject: Adding upstream version 2.06. Signed-off-by: Daniel Baumann --- grub-core/partmap/msdos.c | 435 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 435 insertions(+) create mode 100644 grub-core/partmap/msdos.c (limited to 'grub-core/partmap/msdos.c') diff --git a/grub-core/partmap/msdos.c b/grub-core/partmap/msdos.c new file mode 100644 index 0000000..58c3626 --- /dev/null +++ b/grub-core/partmap/msdos.c @@ -0,0 +1,435 @@ +/* pc.c - Read PC style partition tables. */ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2002,2004,2005,2006,2007,2008,2009 Free Software Foundation, Inc. + * + * GRUB is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * GRUB is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GRUB. If not, see . + */ + +#include +#include +#include +#include +#include +#include +#include + +GRUB_MOD_LICENSE ("GPLv3+"); + +static struct grub_partition_map grub_msdos_partition_map; + + +#ifdef GRUB_UTIL +#include + +struct embed_signature +{ + const char *name; + const char *signature; + int signature_len; + enum { TYPE_SOFTWARE, TYPE_RAID } type; +}; + +const char message_warn[][200] = { + /* TRANSLATORS: MBR gap and boot track is the same thing and is the space + between MBR and first partitition. If your language translates well only + "boot track", you can just use it everywhere. Next two messages are about + RAID controllers/software bugs which GRUB has to live with. Please spread + the message that these are bugs in other software and not merely + suboptimal behaviour. */ + [TYPE_RAID] = N_("Sector %llu is already in use by raid controller `%s';" + " avoiding it. " + "Please ask the manufacturer not to store data in MBR gap"), + [TYPE_SOFTWARE] = N_("Sector %llu is already in use by the program `%s';" + " avoiding it. " + "This software may cause boot or other problems in " + "future. Please ask its authors not to store data " + "in the boot track") +}; + + +/* Signatures of other software that may be using sectors in the embedding + area. */ +struct embed_signature embed_signatures[] = + { + { + .name = "ZISD", + .signature = "ZISD", + .signature_len = 4, + .type = TYPE_SOFTWARE + }, + { + .name = "FlexNet", + .signature = "\xd4\x41\xa0\xf5\x03\x00\x03\x00", + .signature_len = 8, + .type = TYPE_SOFTWARE + }, + { + .name = "FlexNet", + .signature = "\xd8\x41\xa0\xf5\x02\x00\x02\x00", + .signature_len = 8, + .type = TYPE_SOFTWARE + }, + { + /* from Ryan Perkins */ + .name = "HP Backup and Recovery Manager (?)", + .signature = "\x70\x8a\x5d\x46\x35\xc5\x1b\x93" + "\xae\x3d\x86\xfd\xb1\x55\x3e\xe0", + .signature_len = 16, + .type = TYPE_SOFTWARE + }, + { + .name = "HighPoint RAID controller", + .signature = "ycgl", + .signature_len = 4, + .type = TYPE_RAID + }, + { + /* https://bugs.launchpad.net/bugs/987022 */ + .name = "Acer registration utility (?)", + .signature = "GREGRegDone.Tag\x00", + .signature_len = 16, + .type = TYPE_SOFTWARE + } + }; +#endif + +grub_err_t +grub_partition_msdos_iterate (grub_disk_t disk, + grub_partition_iterate_hook_t hook, + void *hook_data) +{ + struct grub_partition p; + struct grub_msdos_partition_mbr mbr; + int labeln = 0; + grub_disk_addr_t lastaddr; + grub_disk_addr_t ext_offset; + grub_disk_addr_t delta = 0; + + if (disk->partition && disk->partition->partmap == &grub_msdos_partition_map) + { + if (disk->partition->msdostype == GRUB_PC_PARTITION_TYPE_LINUX_MINIX) + delta = disk->partition->start; + else + return grub_error (GRUB_ERR_BAD_PART_TABLE, "no embedding supported"); + } + + p.offset = 0; + ext_offset = 0; + p.number = -1; + p.partmap = &grub_msdos_partition_map; + + /* Any value different than `p.offset' will satisfy the check during + first loop. */ + lastaddr = !p.offset; + + while (1) + { + int i; + struct grub_msdos_partition_entry *e; + + /* Read the MBR. */ + if (grub_disk_read (disk, p.offset, 0, sizeof (mbr), &mbr)) + goto finish; + + /* If this is a GPT partition, this MBR is just a dummy. */ + if (p.offset == 0) + for (i = 0; i < 4; i++) + if (mbr.entries[i].type == GRUB_PC_PARTITION_TYPE_GPT_DISK) + return grub_error (GRUB_ERR_BAD_PART_TABLE, "dummy mbr"); + + /* This is our loop-detection algorithm. It works the following way: + It saves last position which was a power of two. Then it compares the + saved value with a current one. This way it's guaranteed that the loop + will be broken by at most third walk. + */ + if (labeln && lastaddr == p.offset) + return grub_error (GRUB_ERR_BAD_PART_TABLE, "loop detected"); + + labeln++; + if ((labeln & (labeln - 1)) == 0) + lastaddr = p.offset; + + /* Check if it is valid. */ + if (mbr.signature != grub_cpu_to_le16_compile_time (GRUB_PC_PARTITION_SIGNATURE)) + return grub_error (GRUB_ERR_BAD_PART_TABLE, "no signature"); + + for (i = 0; i < 4; i++) + if (mbr.entries[i].flag & 0x7f) + return grub_error (GRUB_ERR_BAD_PART_TABLE, "bad boot flag"); + + /* Analyze DOS partitions. */ + for (p.index = 0; p.index < 4; p.index++) + { + e = mbr.entries + p.index; + + p.start = p.offset + + ((grub_disk_addr_t)grub_le_to_cpu32 (e->start) + << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)) - delta; + p.len = (grub_uint64_t)grub_le_to_cpu32 (e->length) + << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS); + p.msdostype = e->type; + + grub_dprintf ("partition", + "partition %d: flag 0x%x, type 0x%x, start 0x%llx, len 0x%llx\n", + p.index, e->flag, e->type, + (unsigned long long) p.start, + (unsigned long long) p.len); + + /* If this partition is a normal one, call the hook. */ + if (! grub_msdos_partition_is_empty (e->type) + && ! grub_msdos_partition_is_extended (e->type)) + { + p.number++; + + if (hook (disk, &p, hook_data)) + return grub_errno; + } + else if (p.number < 3) + /* If this partition is a logical one, shouldn't increase the + partition number. */ + p.number++; + } + + /* Find an extended partition. */ + for (i = 0; i < 4; i++) + { + e = mbr.entries + i; + + if (grub_msdos_partition_is_extended (e->type)) + { + p.offset = ext_offset + + ((grub_disk_addr_t)grub_le_to_cpu32 (e->start) + << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)); + if (! ext_offset) + ext_offset = p.offset; + + break; + } + } + + /* If no extended partition, the end. */ + if (i == 4) + break; + } + + finish: + return grub_errno; +} + +#ifdef GRUB_UTIL + +#pragma GCC diagnostic ignored "-Wformat-nonliteral" + +static grub_err_t +pc_partition_map_embed (struct grub_disk *disk, unsigned int *nsectors, + unsigned int max_nsectors, + grub_embed_type_t embed_type, + grub_disk_addr_t **sectors, + int warn_short) +{ + grub_disk_addr_t end = ~0ULL; + struct grub_msdos_partition_mbr mbr; + int labeln = 0; + /* Any value different than `p.offset' will satisfy the check during + first loop. */ + grub_disk_addr_t lastaddr = 1; + grub_disk_addr_t ext_offset = 0; + grub_disk_addr_t offset = 0; + + if (embed_type != GRUB_EMBED_PCBIOS) + return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET, + "PC-style partitions currently support " + "only PC-BIOS embedding"); + + if (disk->partition) + return grub_error (GRUB_ERR_OUT_OF_RANGE, + "Embedding on MSDOS subpartition isn't supported"); + + while (1) + { + int i; + struct grub_msdos_partition_entry *e; + grub_err_t err; + + /* Read the MBR. */ + err = grub_disk_read (disk, offset, 0, sizeof (mbr), &mbr); + if (err) + return err; + + /* This is our loop-detection algorithm. It works the following way: + It saves last position which was a power of two. Then it compares the + saved value with a current one. This way it's guaranteed that the loop + will be broken by at most third walk. + */ + if (labeln && lastaddr == offset) + return grub_error (GRUB_ERR_BAD_PART_TABLE, "loop detected"); + + labeln++; + if ((labeln & (labeln - 1)) == 0) + lastaddr = offset; + + /* Check if it is valid. */ + if (mbr.signature != grub_cpu_to_le16_compile_time (GRUB_PC_PARTITION_SIGNATURE)) + return grub_error (GRUB_ERR_BAD_PART_TABLE, "no signature"); + + for (i = 0; i < 4; i++) + if (mbr.entries[i].flag & 0x7f) + return grub_error (GRUB_ERR_BAD_PART_TABLE, "bad boot flag"); + + /* Analyze DOS partitions. */ + for (i = 0; i < 4; i++) + { + e = mbr.entries + i; + + if (!grub_msdos_partition_is_empty (e->type) + && end > offset + + ((grub_disk_addr_t)grub_le_to_cpu32 (e->start) + << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS))) + end = offset + ((grub_disk_addr_t)grub_le_to_cpu32 (e->start) + << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)); + + /* If this is a GPT partition, this MBR is just a dummy. */ + if (e->type == GRUB_PC_PARTITION_TYPE_GPT_DISK && i == 0) + return grub_error (GRUB_ERR_BAD_PART_TABLE, "dummy mbr"); + } + + /* Find an extended partition. */ + for (i = 0; i < 4; i++) + { + e = mbr.entries + i; + + if (grub_msdos_partition_is_extended (e->type)) + { + offset = ext_offset + + ((grub_disk_addr_t)grub_le_to_cpu32 (e->start) + << (disk->log_sector_size - GRUB_DISK_SECTOR_BITS)); + if (! ext_offset) + ext_offset = offset; + + break; + } + } + + /* If no extended partition, the end. */ + if (i == 4) + break; + } + + if (end >= *nsectors + 1) + { + unsigned i, j; + char *embed_signature_check; + unsigned int orig_nsectors, avail_nsectors; + + orig_nsectors = *nsectors; + *nsectors = end - 1; + avail_nsectors = *nsectors; + if (*nsectors > max_nsectors) + *nsectors = max_nsectors; + *sectors = grub_calloc (*nsectors, sizeof (**sectors)); + if (!*sectors) + return grub_errno; + for (i = 0; i < *nsectors; i++) + (*sectors)[i] = 1 + i; + + /* Check for software that is already using parts of the embedding + * area. + */ + embed_signature_check = grub_malloc (GRUB_DISK_SECTOR_SIZE); + for (i = 0; i < *nsectors; i++) + { + if (grub_disk_read (disk, (*sectors)[i], 0, GRUB_DISK_SECTOR_SIZE, + embed_signature_check)) + continue; + + for (j = 0; j < ARRAY_SIZE (embed_signatures); j++) + if (! grub_memcmp (embed_signatures[j].signature, + embed_signature_check, + embed_signatures[j].signature_len)) + break; + if (j == ARRAY_SIZE (embed_signatures)) + continue; + grub_util_warn (_(message_warn[embed_signatures[j].type]), + (*sectors)[i], embed_signatures[j].name); + avail_nsectors--; + if (avail_nsectors < *nsectors) + *nsectors = avail_nsectors; + + /* Avoid this sector. */ + for (j = i; j < *nsectors; j++) + (*sectors)[j]++; + + /* Have we run out of space? */ + if (avail_nsectors < orig_nsectors) + break; + + /* Make sure to check the next sector. */ + i--; + } + grub_free (embed_signature_check); + + if (*nsectors < orig_nsectors) + return grub_error (GRUB_ERR_OUT_OF_RANGE, + N_("other software is using the embedding area, and " + "there is not enough room for core.img. Such " + "software is often trying to store data in a way " + "that avoids detection. We recommend you " + "investigate")); + + return GRUB_ERR_NONE; + } + + if (end < GRUB_MIN_RECOMMENDED_MBR_GAP && warn_short) + grub_util_warn ("You have a short MBR gap and use advanced config. Please increase post-MBR gap."); + + if (end <= 1) + return grub_error (GRUB_ERR_FILE_NOT_FOUND, + N_("this msdos-style partition label has no " + "post-MBR gap; embedding won't be possible")); + + if (*nsectors > 62) + return grub_error (GRUB_ERR_OUT_OF_RANGE, + N_("your core.img is unusually large. " + "It won't fit in the embedding area")); + + return grub_error (GRUB_ERR_OUT_OF_RANGE, + N_("your embedding area is unusually small. " + "core.img won't fit in it.")); +} + +#pragma GCC diagnostic error "-Wformat-nonliteral" + +#endif + + +/* Partition map type. */ +static struct grub_partition_map grub_msdos_partition_map = + { + .name = "msdos", + .iterate = grub_partition_msdos_iterate, +#ifdef GRUB_UTIL + .embed = pc_partition_map_embed +#endif + }; + +GRUB_MOD_INIT(part_msdos) +{ + grub_partition_map_register (&grub_msdos_partition_map); +} + +GRUB_MOD_FINI(part_msdos) +{ + grub_partition_map_unregister (&grub_msdos_partition_map); +} -- cgit v1.2.3