[ipxe-devel] [PATCH 1/2] [util] Better processing of ROM images in Option::ROM
Petr Borsodi
petr.borsodi at gmail.com
Wed Jan 16 16:37:57 UTC 2019
The Option::ROM module now compare Code Type in PCIR header to 0x00 (PC-AT)
in order to presence check of other header types (PnP, UNDI, iPXE, ...).
Validity of these headers are checked not only by offset, but range
and signature checks also. Image checksum and initial size of ROM.pm
also depends on Code Type.
---
src/util/Option/ROM.pm | 137 +++++++++++++++++++++++++++++++----------
src/util/disrom.pl | 12 ++--
2 files changed, 110 insertions(+), 39 deletions(-)
diff --git a/src/util/Option/ROM.pm b/src/util/Option/ROM.pm
index 48d92dda..7bbd6986 100644
--- a/src/util/Option/ROM.pm
+++ b/src/util/Option/ROM.pm
@@ -116,7 +116,9 @@ sub EXISTS {
return ( exists $self->{fields}->{$key} &&
( ( $self->{fields}->{$key}->{offset} +
- $self->{fields}->{$key}->{length} ) <= $self->{length} ) );
+ $self->{fields}->{$key}->{length} ) <= $self->{length} ) &&
+ ( ! defined $self->{fields}->{$key}->{check} ||
+ &{$self->{fields}->{$key}->{check}} ( $self, $key ) ) );
}
sub FIRSTKEY {
@@ -172,10 +174,11 @@ use constant ROM_SIGNATURE => 0xaa55;
use constant PCI_SIGNATURE => 'PCIR';
use constant PCI_LAST_IMAGE => 0x80;
use constant PNP_SIGNATURE => '$PnP';
+use constant UNDI_SIGNATURE => 'UNDI';
use constant IPXE_SIGNATURE => 'iPXE';
our @EXPORT_OK = qw ( ROM_SIGNATURE PCI_SIGNATURE PCI_LAST_IMAGE
- PNP_SIGNATURE IPXE_SIGNATURE );
+ PNP_SIGNATURE UNDI_SIGNATURE IPXE_SIGNATURE );
our %EXPORT_TAGS = ( all => [ @EXPORT_OK ] );
use constant JMP_SHORT => 0xeb;
@@ -210,10 +213,20 @@ sub unpack_init {
} elsif ( $jump == 0 ) {
return 0;
} else {
- croak "Unrecognised jump instruction in init vector\n";
+ carp "Unrecognised jump instruction in init vector\n";
+ return 0;
}
}
+sub check_pcat_rom {
+ my $self = shift;
+ my $key = shift;
+
+ my $pci = $self->{rom}->pci_header ();
+
+ return ! defined $pci || $pci->{code_type} == 0x00;
+}
+
=pod
=item C<< new () >>
@@ -227,21 +240,29 @@ sub new {
my $hash = {};
tie %$hash, "Option::ROM::Fields", {
+ rom => $hash, # ROM object itself
data => undef,
offset => 0x00,
length => 0x20,
+ file_offset => 0x0,
fields => {
signature => { offset => 0x00, length => 0x02, pack => "S" },
length => { offset => 0x02, length => 0x01, pack => "C" },
# "init" is part of a jump instruction
init => { offset => 0x03, length => 0x03,
- pack => \&pack_init, unpack => \&unpack_init },
- checksum => { offset => 0x06, length => 0x01, pack => "C" },
- ipxe_header => { offset => 0x10, length => 0x02, pack => "S" },
- bofm_header => { offset => 0x14, length => 0x02, pack => "S" },
- undi_header => { offset => 0x16, length => 0x02, pack => "S" },
+ pack => \&pack_init, unpack => \&unpack_init,
+ check => \&check_pcat_rom },
+ checksum => { offset => 0x06, length => 0x01, pack => "C",
+ check => \&check_pcat_rom },
+ ipxe_header => { offset => 0x10, length => 0x02, pack => "S",
+ check => \&check_pcat_rom },
+ bofm_header => { offset => 0x14, length => 0x02, pack => "S",
+ check => \&check_pcat_rom },
+ undi_header => { offset => 0x16, length => 0x02, pack => "S",
+ check => \&check_pcat_rom },
pci_header => { offset => 0x18, length => 0x02, pack => "S" },
- pnp_header => { offset => 0x1a, length => 0x02, pack => "S" },
+ pnp_header => { offset => 0x1a, length => 0x02, pack => "S",
+ check => \&check_pcat_rom },
},
};
bless $hash, $class;
@@ -250,9 +271,9 @@ sub new {
=pod
-=item C<< set ( $data ) >>
+=item C<< set ( $data [, $file_offset ] ) >>
-Set option ROM contents.
+Set option ROM contents, optionally sets original file offset.
=cut
@@ -260,9 +281,11 @@ sub set {
my $hash = shift;
my $self = tied(%$hash);
my $data = shift;
+ my $file_offset = shift // 0x0;
# Store data
$self->{data} = \$data;
+ $self->{file_offset} = $file_offset;
# Split out any data belonging to the next image
delete $self->{next_image};
@@ -273,7 +296,7 @@ sub set {
my $remainder = substr ( $data, $length );
$data = substr ( $data, 0, $length );
$self->{next_image} = new Option::ROM;
- $self->{next_image}->set ( $remainder );
+ $self->{next_image}->set ( $remainder, $self->{file_offset} + $length );
}
}
@@ -311,6 +334,7 @@ sub load {
open my $fh, "<$filename"
or croak "Cannot open $filename for reading: $!";
+ binmode $fh;
read $fh, my $data, -s $fh;
$hash->set ( $data );
close $fh;
@@ -335,6 +359,7 @@ sub save {
open my $fh, ">$filename"
or croak "Cannot open $filename for writing: $!";
my $data = $hash->get();
+ binmode $fh;
print $fh $data;
close $fh;
}
@@ -369,9 +394,9 @@ sub pci_header {
my $self = tied(%$hash);
my $offset = $hash->{pci_header};
- return undef unless $offset != 0;
+ return undef unless $offset;
- return Option::ROM::PCI->new ( $self->{data}, $offset );
+ return Option::ROM::PCI->new ( $self, $offset );
}
=pod
@@ -388,9 +413,9 @@ sub pnp_header {
my $self = tied(%$hash);
my $offset = $hash->{pnp_header};
- return undef unless $offset != 0;
+ return undef unless $offset;
- return Option::ROM::PnP->new ( $self->{data}, $offset );
+ return Option::ROM::PnP->new ( $self, $offset );
}
=pod
@@ -407,9 +432,9 @@ sub undi_header {
my $self = tied(%$hash);
my $offset = $hash->{undi_header};
- return undef unless $offset != 0;
+ return undef unless $offset;
- return Option::ROM::UNDI->new ( $self->{data}, $offset );
+ return Option::ROM::UNDI->new ( $self, $offset );
}
=pod
@@ -426,9 +451,9 @@ sub ipxe_header {
my $self = tied(%$hash);
my $offset = $hash->{ipxe_header};
- return undef unless $offset != 0;
+ return undef unless $offset;
- return Option::ROM::iPXE->new ( $self->{data}, $offset );
+ return Option::ROM::iPXE->new ( $self, $offset );
}
=pod
@@ -475,9 +500,25 @@ sub fix_checksum {
my $hash = shift;
my $self = tied(%$hash);
+ return unless ( exists $hash->{checksum} );
$hash->{checksum} = ( ( $hash->{checksum} - $hash->checksum() ) & 0xff );
}
+=pod
+
+=item C<< file_offset () >>
+
+Get file offset of image.
+
+=cut
+
+sub file_offset {
+ my $hash = shift;
+ my $self = tied(%$hash);
+
+ return $self->{file_offset};
+}
+
##############################################################################
#
# Option::ROM::PCI
@@ -493,12 +534,13 @@ use bytes;
sub new {
my $class = shift;
- my $data = shift;
+ my $rom = shift;
my $offset = shift;
my $hash = {};
tie %$hash, "Option::ROM::Fields", {
- data => $data,
+ rom => $rom,
+ data => $rom->{data},
offset => $offset,
length => 0x0c,
fields => {
@@ -522,11 +564,17 @@ sub new {
};
bless $hash, $class;
- # Retrieve true length of structure
my $self = tied ( %$hash );
+ my $length = $rom->{rom}->length ();
+
+ return undef unless ( $offset + $self->{length} <= $length &&
+ $hash->{signature} eq Option::ROM::PCI_SIGNATURE &&
+ $offset + $hash->{struct_length} <= $length );
+
+ # Retrieve true length of structure
$self->{length} = $hash->{struct_length};
- return $hash;
+ return $hash;
}
sub device_list {
@@ -564,12 +612,13 @@ use bytes;
sub new {
my $class = shift;
- my $data = shift;
+ my $rom = shift;
my $offset = shift;
my $hash = {};
tie %$hash, "Option::ROM::Fields", {
- data => $data,
+ rom => $rom,
+ data => $rom->{data},
offset => $offset,
length => 0x06,
fields => {
@@ -586,11 +635,17 @@ sub new {
};
bless $hash, $class;
- # Retrieve true length of structure
my $self = tied ( %$hash );
+ my $length = $rom->{rom}->length ();
+
+ return undef unless ( $offset + $self->{length} <= $length &&
+ $hash->{signature} eq Option::ROM::PNP_SIGNATURE &&
+ $offset + $hash->{struct_length} * 16 <= $length );
+
+ # Retrieve true length of structure
$self->{length} = ( $hash->{struct_length} * 16 );
- return $hash;
+ return $hash;
}
sub checksum {
@@ -644,12 +699,13 @@ use bytes;
sub new {
my $class = shift;
- my $data = shift;
+ my $rom = shift;
my $offset = shift;
my $hash = {};
tie %$hash, "Option::ROM::Fields", {
- data => $data,
+ rom => $rom,
+ data => $rom->{data},
offset => $offset,
length => 0x16,
fields => {
@@ -669,8 +725,14 @@ sub new {
};
bless $hash, $class;
- # Retrieve true length of structure
my $self = tied ( %$hash );
+ my $length = $rom->{rom}->length ();
+
+ return undef unless ( $offset + $self->{length} <= $length &&
+ $hash->{signature} eq Option::ROM::UNDI_SIGNATURE &&
+ $offset + $hash->{struct_length} <= $length );
+
+ # Retrieve true length of structure
$self->{length} = $hash->{struct_length};
return $hash;
@@ -705,12 +767,13 @@ use bytes;
sub new {
my $class = shift;
- my $data = shift;
+ my $rom = shift;
my $offset = shift;
my $hash = {};
tie %$hash, "Option::ROM::Fields", {
- data => $data,
+ rom => $rom,
+ data => $rom->{data},
offset => $offset,
length => 0x06,
fields => {
@@ -723,8 +786,14 @@ sub new {
};
bless $hash, $class;
- # Retrieve true length of structure
my $self = tied ( %$hash );
+ my $length = $rom->{rom}->length ();
+
+ return undef unless ( $offset + $self->{length} <= $length &&
+ $hash->{signature} eq Option::ROM::IPXE_SIGNATURE &&
+ $offset + $hash->{struct_length} <= $length );
+
+ # Retrieve true length of structure
$self->{length} = $hash->{struct_length};
return $hash;
diff --git a/src/util/disrom.pl b/src/util/disrom.pl
index 920a86b2..71eee590 100755
--- a/src/util/disrom.pl
+++ b/src/util/disrom.pl
@@ -28,8 +28,9 @@ my $romfile = shift || "-";
my $rom = new Option::ROM;
$rom->load ( $romfile );
-do {
+my $index = 0;
+do {
die "Not an option ROM image\n"
unless $rom->{signature} == ROM_SIGNATURE;
@@ -38,15 +39,16 @@ do {
die "ROM image truncated (is $filelength, should be $romlength)\n"
if $filelength < $romlength;
+ printf "Index: %d, offset: 0x%08x\n\n", $index++, $rom->file_offset;
printf "ROM header:\n\n";
printf " %-16s 0x%02x (%d)\n", "Length:",
$rom->{length}, ( $rom->{length} * 512 );
printf " %-16s 0x%02x (%s0x%02x)\n", "Checksum:", $rom->{checksum},
- ( ( $rom->checksum == 0 ) ? "" : "INCORRECT: " ), $rom->checksum;
- printf " %-16s 0x%04x\n", "Init:", $rom->{init};
- printf " %-16s 0x%04x\n", "UNDI header:", $rom->{undi_header};
+ ( ( $rom->checksum () == 0 ) ? "" : "INCORRECT: " ), $rom->checksum () if ( exists $rom->{checksum} );
+ printf " %-16s 0x%04x\n", "Init:", $rom->{init} if ( defined $rom->{init} );
+ printf " %-16s 0x%04x\n", "UNDI header:", $rom->{undi_header} if ( exists $rom->{undi_header} );
printf " %-16s 0x%04x\n", "PCI header:", $rom->{pci_header};
- printf " %-16s 0x%04x\n", "PnP header:", $rom->{pnp_header};
+ printf " %-16s 0x%04x\n", "PnP header:", $rom->{pnp_header} if ( exists $rom->{pnp_header} );
printf "\n";
my $pci = $rom->pci_header();
--
2.20.1.windows.1
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