package partition_table::gpt; # $Id: gpt.pm 240647 2008-03-25 17:19:28Z pixel $ use diagnostics; use strict; use vars qw(@ISA); @ISA = qw(partition_table::raw); use common; use partition_table::raw; use partition_table::dos; use partition_table; use fs::type; use c; my %gpt_types = ( 0x00 => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 0x82 => "\x6d\xfd\x57\x06\xab\xa4\xc4\x43\x84\xe5\x09\x33\xc8\x4b\x4f\x4f", 0x83 => "\xA2\xA0\xD0\xEB\xE5\xB9\x33\x44\x87\xC0\x68\xB6\xB7\x26\x99\xC7", 0x8e => "\x79\xd3\xd6\xe6\x07\xf5\xc2\x44\xa2\x3c\x23\x8f\x2a\x3d\xf9\x28", 0xfd => "\x0f\x88\x9d\xa1\xfc\x05\x3b\x4d\xa0\x06\x74\x3f\x0f\x84\x91\x1e", 0xef => "\x28\x73\x2A\xC1\x1F\xF8\xd2\x11\xBA\x4B\x00\xA0\xC9\x3E\xC9\x3B", # legacy_partition_table => "\x41\xEE\x4D\x02\xE7\x33\xd3\x11\x9D\x69\x00\x08\xC7\x81\xF3\x9F" # PARTITION_MSFT_RESERVED_GUID "\x16\xE3\xC9\xE3\x5C\x0B\xB8\x4D\x81\x7D\xF9\x2D\xF0\x02\x15\xAE" #PARTITION_RESERVED_GUID "\x39\x33\xa6\x8d\x07\x00\xc0\x60\xc4\x36\x08\x3a\xc8\x23\x09\x08" ); my $current_revision = 0x00010200; my ($main_format, $main_fields) = list2kv( a8 => 'magic', V => 'revision', V => 'headerSize', V => 'headerCRC32', a4 => 'blank1', Q => 'myLBA', Q => 'alternateLBA', Q => 'firstUsableLBA', Q => 'lastUsableLBA', a16 => 'guid', Q => 'partitionEntriesLBA', V => 'nbPartitions', V => 'partitionEntrySize', V => 'partitionEntriesCRC32', ); my ($partitionEntry_format, $partitionEntry_fields) = list2kv( a16 => 'gpt_type', a16 => 'guid', Q => 'start', Q => 'ending', a8 => 'efi_attributes', a72 => 'name', ); my ($guid_format, $guid_fields) = list2kv( N => 'time_low', n => 'time_mid', n => 'time_hi_and_version', n => 'clock_seq', a6 => 'node', ); $_ = join('', @$_) foreach $main_format, $partitionEntry_format, $guid_format; my $magic = "EFI PART"; sub generate_guid() { my $tmp; open(my $F, devices::make("random")) or die "Could not open /dev/random for GUID generation"; read $F, $tmp, psizeof($guid_format); my %guid; @guid{@$guid_fields} = unpack $guid_format, $tmp; $guid{clock_seq} = ($guid{clock_seq} & 0x3fff) | 0x8000; $guid{time_hi_and_version} = ($guid{time_hi_and_version} & 0x0fff) | 0x4000; pack($guid_format, @guid{@$guid_fields}); } sub crc32 { my ($buffer) = @_; my $crc = 0xFFFFFFFF; foreach (unpack "C*", $buffer) { my $subcrc = ($crc ^ $_) & 0xFF; for (my $j = 8; $j > 0; $j--) { my $b = $subcrc & 1; $subcrc = ($subcrc >> 1) & 0x7FFFFFFF; $subcrc = $subcrc ^ 0xEDB88320 if $b; } $crc = ($crc >> 8) ^ $subcrc; } $crc ^ 0xFFFFFFFF; } sub compute_headerCRC32 { my ($info) = @_; local $info->{headerCRC32} = 0; crc32(pack($main_format, @$info{@$main_fields})); } sub read_header { my ($sector, $F) = @_; my $tmp; c::lseek_sector(fileno($F), $sector, 0) or die "reading of partition in sector $sector failed"; sysread $F, $tmp, psizeof($main_format) or die "error while reading partition table in sector $sector"; my %info; @info{@$main_fields} = unpack $main_format, $tmp; $info{magic} eq $magic or die "bad magic number"; $info{myLBA} == $sector or die "myLBA is not the same"; $info{headerSize} == psizeof($main_format) or die "bad partition table header size"; $info{partitionEntrySize} == psizeof($partitionEntry_format) or die "bad partitionEntrySize"; $info{revision} <= $current_revision or log::l("oops, this is a new GPT revision ($info{revision} > $current_revision)"); $info{headerCRC32} == compute_headerCRC32(\%info) or die "bad partition table checksum"; \%info; } sub read_partitionEntries { my ($info, $F) = @_; my $tmp; c::lseek_sector(fileno($F), $info->{partitionEntriesLBA}, 0) or die "can not seek to sector partitionEntriesLBA"; sysread $F, $tmp, psizeof($partitionEntry_format) * $info->{nbPartitions} or die "error while reading partition table in sector $info->{partitionEntriesLBA}"; $info->{partitionEntriesCRC32} == crc32($tmp) or die "bad partition entries checksum"; c::lseek_sector(fileno($F), $info->{partitionEntriesLBA}, 0) or die "can not seek to sector partitionEntriesLBA"; my %gpt_types_rev = reverse %gpt_types; my @pt = map { sysread $F, $tmp, psizeof($partitionEntry_format) or die "error while reading partition table in sector $info->{partitionEntriesLBA}"; my %h; @h{@$partitionEntry_fields} = unpack $partitionEntry_format, $tmp; $h{size} = $h{ending} - $h{start} + 1; my $pt_type = $gpt_types_rev{$h{gpt_type}}; fs::type::set_pt_type(\%h, defined $pt_type ? $pt_type : 0x100); \%h; } (1 .. $info->{nbPartitions}); \@pt; } sub read_one { my ($hd, $sector) = @_; my $l = partition_table::dos::read($hd, $sector); my @l = grep { $_->{size} && $_->{pt_type} && !partition_table::isExtended($_) } @$l; @l == 1 or die "bad PMBR"; $l[0]{pt_type} == 0xee or die "bad PMBR"; my $myLBA = $l[0]{start}; my $F = partition_table::raw::openit($hd) or die "failed to open device"; my $info1 = eval { read_header($myLBA, $F) }; my $info2 = eval { read_header($info1->{alternateLBA} || $l[0]{start} + $l[0]{size} - 1, $F) }; #- what about using $hd->{totalsectors} ??? my $info = $info1 || { %$info2, myLBA => $info2->{alternateLBA}, alternateLBA => $info2->{myLBA}, partitionEntriesLBA => $info2->{alternateLBA} + 1 } or die; my $pt = $info1 && $info2 ? eval { $info1 && read_partitionEntries($info1, $F) } || read_partitionEntries($info2, $F) : read_partitionEntries($info, $F); $hd->raw_removed($pt); $pt, $info; } # write the partition table (and extended ones) # for each entry, it uses fields: start, size, pt_type, active sub write { my ($hd, $sector, $pt, $info) = @_; foreach (@$pt) { $_->{ending} = $_->{start} + $_->{size} - 1; $_->{guid} ||= generate_guid(); $_->{gpt_type} = $gpt_types{$_->{pt_type}} || $_->{gpt_type} || $gpt_types{0x83}; } my $partitionEntries = join('', map { pack($partitionEntry_format, @$_{@$partitionEntry_fields}); } (@$pt, ({}) x ($info->{nbPartitions} - @$pt))); $info->{partitionEntriesCRC32} = crc32($partitionEntries); $info->{headerCRC32} = compute_headerCRC32($info); my $info2 = { %$info, myLBA => $info->{alternateLBA}, alternateLBA => $info->{myLBA}, partitionEntriesLBA => $info->{alternateLBA} - psizeof($partitionEntry_format) * $info->{nbPartitions} / 512, }; $info2->{headerCRC32} = compute_headerCRC32($info2); { # write the PMBR my $pmbr = partition_table::dos::empty_raw(); $pmbr->{raw}[0] = { pt_type => 0xee, local_start => $info->{myLBA}, size => $info->{alternateLBA} - $info->{myLBA} + 1 }; partition_table::dos::write($hd, $sector, $pmbr->{raw}); } my $F = partition_table::raw::openit($hd, 2) or die "error opening device $hd->{device} for writing"; c::lseek_sector(fileno($F), $info->{myLBA}, 0) or return 0; #- pad with 0's syswrite $F, pack($main_format, @$info{@$main_fields}) . "\0" x 512, 512 or return 0; c::lseek_sector(fileno($F), $info->{alternateLBA}, 0) or return 0; #- pad with 0's syswrite $F, pack($main_format, @$info2{@$main_fields}) . "\0" x 512, 512 or return 0; c::lseek_sector(fileno($F), $info->{partitionEntriesLBA}, 0) or return 0; syswrite $F, $partitionEntries or return 0; c::lseek_sector(fileno($F), $info2->{partitionEntriesLBA}, 0) or return 0; syswrite $F, $partitionEntries or return 0; common::sync(); 1; } sub raw_removed { my ($_hd, $raw) = @_; @$raw = grep { $_->{size} && $_->{pt_type} } @$raw; } sub can_add { &can_raw_add } sub can_raw_add { my ($hd) = @_; @{$hd->{primary}{raw}} < $hd->{primary}{info}{nbPartitions}; } sub raw_add { my ($hd, $raw, $part) = @_; $hd->can_raw_add or die "raw_add: partition table already full"; push @$raw, $part; } sub use_pt_type { 1 } sub adjustStart {} sub adjustEnd {} sub first_usable_sector { my ($hd) = @_; $hd->{primary}{info}{firstUsableLBA}; } sub last_usable_sector { my ($hd) = @_; $hd->{primary}{info}{lastUsableLBA} + 1; } sub info { my ($hd) = @_; my $nb_sect = 32; #- build a default suitable partition table, #- checksum will be built when writing on disk. { magic => $magic, revision => $current_revision, headerSize => psizeof($main_format), myLBA => 1, alternateLBA => $hd->{totalsectors} - 1, firstUsableLBA => $nb_sect + 2, lastUsableLBA => $hd->{totalsectors} - $nb_sect - 2, guid => generate_guid(), partitionEntriesLBA => 2, nbPartitions => $nb_sect * 512 / psizeof($partitionEntry_format), partitionEntrySize => psizeof($partitionEntry_format), }; } sub initialize { my ($class, $hd) = @_; $hd->{primary} = { raw => [], info => info($hd) }; bless $hd, $class; } 1;