1
1
mirror of https://github.com/systemd/systemd-stable.git synced 2024-12-24 21:34:08 +03:00

sd-boot: Move xbootldr code into its own file

This commit is contained in:
Jan Janssen 2021-09-27 10:02:50 +02:00 committed by Lennart Poettering
parent 6e7bb7d3ee
commit bcbc3e81d3
4 changed files with 226 additions and 192 deletions

View File

@ -17,6 +17,7 @@
#include "secure-boot.h"
#include "shim.h"
#include "util.h"
#include "xbootldr.h"
#ifndef EFI_OS_INDICATIONS_BOOT_TO_FW_UI
#define EFI_OS_INDICATIONS_BOOT_TO_FW_UI 0x0000000000000001ULL
@ -2098,208 +2099,19 @@ static VOID config_entry_add_linux(
}
}
#define XBOOTLDR_GUID \
&(const EFI_GUID) { 0xbc13c2ff, 0x59e6, 0x4262, { 0xa3, 0x52, 0xb2, 0x75, 0xfd, 0x6f, 0x71, 0x72 } }
static EFI_DEVICE_PATH *path_parent(EFI_DEVICE_PATH *path, EFI_DEVICE_PATH *node) {
EFI_DEVICE_PATH *parent;
UINTN len;
assert(path);
assert(node);
len = (UINT8*) NextDevicePathNode(node) - (UINT8*) path;
parent = (EFI_DEVICE_PATH*) AllocatePool(len + sizeof(EFI_DEVICE_PATH));
CopyMem(parent, path, len);
CopyMem((UINT8*) parent + len, EndDevicePath, sizeof(EFI_DEVICE_PATH));
return parent;
}
static VOID config_load_xbootldr(
Config *config,
EFI_HANDLE *device) {
EFI_DEVICE_PATH *partition_path, *disk_path, *copy;
UINT32 found_partition_number = UINT32_MAX;
UINT64 found_partition_start = UINT64_MAX;
UINT64 found_partition_size = UINT64_MAX;
UINT8 found_partition_signature[16] = {};
EFI_HANDLE new_device;
EFI_FILE *root_dir;
EFI_STATUS r;
EFI_STATUS err;
assert(config);
assert(device);
partition_path = DevicePathFromHandle(device);
if (!partition_path)
return;
for (EFI_DEVICE_PATH *node = partition_path; !IsDevicePathEnd(node); node = NextDevicePathNode(node)) {
EFI_HANDLE disk_handle;
EFI_BLOCK_IO *block_io;
EFI_DEVICE_PATH *p;
/* First, Let's look for the SCSI/SATA/USB/… device path node, i.e. one above the media
* devices */
if (DevicePathType(node) != MESSAGING_DEVICE_PATH)
continue;
/* Determine the device path one level up */
disk_path = path_parent(partition_path, node);
p = disk_path;
r = uefi_call_wrapper(BS->LocateDevicePath, 3, &BlockIoProtocol, &p, &disk_handle);
if (EFI_ERROR(r))
continue;
r = uefi_call_wrapper(BS->HandleProtocol, 3, disk_handle, &BlockIoProtocol, (VOID **)&block_io);
if (EFI_ERROR(r))
continue;
/* Filter out some block devices early. (We only care about block devices that aren't
* partitions themselves we look for GPT partition tables to parse after all , and only
* those which contain a medium and have at least 2 blocks.) */
if (block_io->Media->LogicalPartition ||
!block_io->Media->MediaPresent ||
block_io->Media->LastBlock <= 1)
continue;
/* Try both copies of the GPT header, in case one is corrupted */
for (UINTN nr = 0; nr < 2; nr++) {
_cleanup_freepool_ EFI_PARTITION_ENTRY* entries = NULL;
union {
EFI_PARTITION_TABLE_HEADER gpt_header;
uint8_t space[((sizeof(EFI_PARTITION_TABLE_HEADER) + 511) / 512) * 512];
} gpt_header_buffer;
EFI_PARTITION_TABLE_HEADER *h = &gpt_header_buffer.gpt_header;
UINT64 where;
UINTN sz;
UINT32 crc32, crc32_saved;
if (nr == 0)
/* Read the first copy at LBA 1 */
where = 1;
else
/* Read the second copy at the very last LBA of this block device */
where = block_io->Media->LastBlock;
/* Read the GPT header */
r = uefi_call_wrapper(block_io->ReadBlocks, 5,
block_io,
block_io->Media->MediaId,
where,
sizeof(gpt_header_buffer), &gpt_header_buffer);
if (EFI_ERROR(r))
continue;
/* Some superficial validation of the GPT header */
if(CompareMem(&h->Header.Signature, "EFI PART", sizeof(h->Header.Signature) != 0))
continue;
if (h->Header.HeaderSize < 92 ||
h->Header.HeaderSize > 512)
continue;
if (h->Header.Revision != 0x00010000U)
continue;
/* Calculate CRC check */
crc32_saved = h->Header.CRC32;
h->Header.CRC32 = 0;
r = BS->CalculateCrc32(&gpt_header_buffer, h->Header.HeaderSize, &crc32);
h->Header.CRC32 = crc32_saved;
if (EFI_ERROR(r) || crc32 != crc32_saved)
continue;
if (h->MyLBA != where)
continue;
if (h->SizeOfPartitionEntry < sizeof(EFI_PARTITION_ENTRY))
continue;
if (h->NumberOfPartitionEntries <= 0 ||
h->NumberOfPartitionEntries > 1024)
continue;
if (h->SizeOfPartitionEntry > UINTN_MAX / h->NumberOfPartitionEntries) /* overflow check */
continue;
/* Now load the GPT entry table */
sz = ALIGN_TO((UINTN) h->SizeOfPartitionEntry * (UINTN) h->NumberOfPartitionEntries, 512);
entries = AllocatePool(sz);
r = uefi_call_wrapper(block_io->ReadBlocks, 5,
block_io,
block_io->Media->MediaId,
h->PartitionEntryLBA,
sz, entries);
if (EFI_ERROR(r))
continue;
/* Calculate CRC of entries array, too */
r = BS->CalculateCrc32(&entries, sz, &crc32);
if (EFI_ERROR(r) || crc32 != h->PartitionEntryArrayCRC32)
continue;
for (UINTN i = 0; i < h->NumberOfPartitionEntries; i++) {
EFI_PARTITION_ENTRY *entry;
entry = (EFI_PARTITION_ENTRY*) ((UINT8*) entries + h->SizeOfPartitionEntry * i);
if (CompareMem(&entry->PartitionTypeGUID, XBOOTLDR_GUID, 16) == 0) {
UINT64 end;
/* Let's use memcpy(), in case the structs are not aligned (they really should be though) */
CopyMem(&found_partition_start, &entry->StartingLBA, sizeof(found_partition_start));
CopyMem(&end, &entry->EndingLBA, sizeof(end));
if (end < found_partition_start) /* Bogus? */
continue;
found_partition_size = end - found_partition_start + 1;
CopyMem(found_partition_signature, &entry->UniquePartitionGUID, sizeof(found_partition_signature));
found_partition_number = i + 1;
goto found;
}
}
break; /* This GPT was fully valid, but we didn't find what we are looking for. This
* means there's no reason to check the second copy of the GPT header */
}
}
return; /* Not found */
found:
copy = DuplicateDevicePath(partition_path);
/* Patch in the data we found */
for (EFI_DEVICE_PATH *node = copy; !IsDevicePathEnd(node); node = NextDevicePathNode(node)) {
HARDDRIVE_DEVICE_PATH *hd;
if (DevicePathType(node) != MEDIA_DEVICE_PATH)
continue;
if (DevicePathSubType(node) != MEDIA_HARDDRIVE_DP)
continue;
hd = (HARDDRIVE_DEVICE_PATH*) node;
hd->PartitionNumber = found_partition_number;
hd->PartitionStart = found_partition_start;
hd->PartitionSize = found_partition_size;
CopyMem(hd->Signature, found_partition_signature, sizeof(hd->Signature));
hd->MBRType = MBR_TYPE_EFI_PARTITION_TABLE_HEADER;
hd->SignatureType = SIGNATURE_TYPE_GUID;
}
r = uefi_call_wrapper(BS->LocateDevicePath, 3, &BlockIoProtocol, &copy, &new_device);
if (EFI_ERROR(r))
return;
root_dir = LibOpenRoot(new_device);
if (!root_dir)
err = xbootldr_open(device, &new_device, &root_dir);
if (EFI_ERROR(err))
return;
config_entry_add_linux(config, new_device, root_dir);

View File

@ -15,6 +15,7 @@ efi_headers = files('''
shim.h
splash.h
util.h
xbootldr.h
'''.split())
common_sources = '''
@ -34,6 +35,7 @@ systemd_boot_sources = '''
drivers.c
random-seed.c
shim.c
xbootldr.c
'''.split()
stub_sources = '''

212
src/boot/efi/xbootldr.c Normal file
View File

@ -0,0 +1,212 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <efi.h>
#include <efigpt.h>
#include <efilib.h>
#include "util.h"
#include "xbootldr.h"
static EFI_DEVICE_PATH *path_parent(EFI_DEVICE_PATH *path, EFI_DEVICE_PATH *node) {
EFI_DEVICE_PATH *parent;
UINTN len;
assert(path);
assert(node);
len = (UINT8*) NextDevicePathNode(node) - (UINT8*) path;
parent = (EFI_DEVICE_PATH*) AllocatePool(len + sizeof(EFI_DEVICE_PATH));
CopyMem(parent, path, len);
CopyMem((UINT8*) parent + len, EndDevicePath, sizeof(EFI_DEVICE_PATH));
return parent;
}
EFI_STATUS xbootldr_open(EFI_HANDLE *device, EFI_HANDLE *ret_device, EFI_FILE **ret_root_dir) {
EFI_DEVICE_PATH *partition_path, *disk_path, *copy;
UINT32 found_partition_number = UINT32_MAX;
UINT64 found_partition_start = UINT64_MAX;
UINT64 found_partition_size = UINT64_MAX;
UINT8 found_partition_signature[16] = {};
EFI_HANDLE new_device;
EFI_FILE *root_dir;
EFI_STATUS r;
assert(device);
assert(ret_device);
assert(ret_root_dir);
partition_path = DevicePathFromHandle(device);
if (!partition_path)
return EFI_NOT_FOUND;
for (EFI_DEVICE_PATH *node = partition_path; !IsDevicePathEnd(node); node = NextDevicePathNode(node)) {
EFI_HANDLE disk_handle;
EFI_BLOCK_IO *block_io;
EFI_DEVICE_PATH *p;
/* First, Let's look for the SCSI/SATA/USB/… device path node, i.e. one above the media
* devices */
if (DevicePathType(node) != MESSAGING_DEVICE_PATH)
continue;
/* Determine the device path one level up */
disk_path = path_parent(partition_path, node);
p = disk_path;
r = uefi_call_wrapper(BS->LocateDevicePath, 3, &BlockIoProtocol, &p, &disk_handle);
if (EFI_ERROR(r))
continue;
r = uefi_call_wrapper(BS->HandleProtocol, 3, disk_handle, &BlockIoProtocol, (VOID **)&block_io);
if (EFI_ERROR(r))
continue;
/* Filter out some block devices early. (We only care about block devices that aren't
* partitions themselves we look for GPT partition tables to parse after all , and only
* those which contain a medium and have at least 2 blocks.) */
if (block_io->Media->LogicalPartition ||
!block_io->Media->MediaPresent ||
block_io->Media->LastBlock <= 1)
continue;
/* Try both copies of the GPT header, in case one is corrupted */
for (UINTN nr = 0; nr < 2; nr++) {
_cleanup_freepool_ EFI_PARTITION_ENTRY* entries = NULL;
union {
EFI_PARTITION_TABLE_HEADER gpt_header;
uint8_t space[((sizeof(EFI_PARTITION_TABLE_HEADER) + 511) / 512) * 512];
} gpt_header_buffer;
EFI_PARTITION_TABLE_HEADER *h = &gpt_header_buffer.gpt_header;
UINT64 where;
UINTN sz;
UINT32 crc32, crc32_saved;
if (nr == 0)
/* Read the first copy at LBA 1 */
where = 1;
else
/* Read the second copy at the very last LBA of this block device */
where = block_io->Media->LastBlock;
/* Read the GPT header */
r = uefi_call_wrapper(block_io->ReadBlocks, 5,
block_io,
block_io->Media->MediaId,
where,
sizeof(gpt_header_buffer), &gpt_header_buffer);
if (EFI_ERROR(r))
continue;
/* Some superficial validation of the GPT header */
if(CompareMem(&h->Header.Signature, "EFI PART", sizeof(h->Header.Signature) != 0))
continue;
if (h->Header.HeaderSize < 92 ||
h->Header.HeaderSize > 512)
continue;
if (h->Header.Revision != 0x00010000U)
continue;
/* Calculate CRC check */
crc32_saved = h->Header.CRC32;
h->Header.CRC32 = 0;
r = BS->CalculateCrc32(&gpt_header_buffer, h->Header.HeaderSize, &crc32);
h->Header.CRC32 = crc32_saved;
if (EFI_ERROR(r) || crc32 != crc32_saved)
continue;
if (h->MyLBA != where)
continue;
if (h->SizeOfPartitionEntry < sizeof(EFI_PARTITION_ENTRY))
continue;
if (h->NumberOfPartitionEntries <= 0 ||
h->NumberOfPartitionEntries > 1024)
continue;
if (h->SizeOfPartitionEntry > UINTN_MAX / h->NumberOfPartitionEntries) /* overflow check */
continue;
/* Now load the GPT entry table */
sz = ALIGN_TO((UINTN) h->SizeOfPartitionEntry * (UINTN) h->NumberOfPartitionEntries, 512);
entries = AllocatePool(sz);
r = uefi_call_wrapper(block_io->ReadBlocks, 5,
block_io,
block_io->Media->MediaId,
h->PartitionEntryLBA,
sz, entries);
if (EFI_ERROR(r))
continue;
/* Calculate CRC of entries array, too */
r = BS->CalculateCrc32(&entries, sz, &crc32);
if (EFI_ERROR(r) || crc32 != h->PartitionEntryArrayCRC32)
continue;
for (UINTN i = 0; i < h->NumberOfPartitionEntries; i++) {
EFI_PARTITION_ENTRY *entry;
entry = (EFI_PARTITION_ENTRY*) ((UINT8*) entries + h->SizeOfPartitionEntry * i);
if (CompareMem(&entry->PartitionTypeGUID, XBOOTLDR_GUID, 16) == 0) {
UINT64 end;
/* Let's use memcpy(), in case the structs are not aligned (they really should be though) */
CopyMem(&found_partition_start, &entry->StartingLBA, sizeof(found_partition_start));
CopyMem(&end, &entry->EndingLBA, sizeof(end));
if (end < found_partition_start) /* Bogus? */
continue;
found_partition_size = end - found_partition_start + 1;
CopyMem(found_partition_signature, &entry->UniquePartitionGUID, sizeof(found_partition_signature));
found_partition_number = i + 1;
goto found;
}
}
break; /* This GPT was fully valid, but we didn't find what we are looking for. This
* means there's no reason to check the second copy of the GPT header */
}
}
return EFI_NOT_FOUND;
found:
copy = DuplicateDevicePath(partition_path);
/* Patch in the data we found */
for (EFI_DEVICE_PATH *node = copy; !IsDevicePathEnd(node); node = NextDevicePathNode(node)) {
HARDDRIVE_DEVICE_PATH *hd;
if (DevicePathType(node) != MEDIA_DEVICE_PATH)
continue;
if (DevicePathSubType(node) != MEDIA_HARDDRIVE_DP)
continue;
hd = (HARDDRIVE_DEVICE_PATH*) node;
hd->PartitionNumber = found_partition_number;
hd->PartitionStart = found_partition_start;
hd->PartitionSize = found_partition_size;
CopyMem(hd->Signature, found_partition_signature, sizeof(hd->Signature));
hd->MBRType = MBR_TYPE_EFI_PARTITION_TABLE_HEADER;
hd->SignatureType = SIGNATURE_TYPE_GUID;
}
r = uefi_call_wrapper(BS->LocateDevicePath, 3, &BlockIoProtocol, &copy, &new_device);
if (EFI_ERROR(r))
return r;
root_dir = LibOpenRoot(new_device);
if (!root_dir)
return EFI_DEVICE_ERROR;
*ret_device = new_device;
*ret_root_dir = root_dir;
return EFI_SUCCESS;
}

8
src/boot/efi/xbootldr.h Normal file
View File

@ -0,0 +1,8 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <efi.h>
#define XBOOTLDR_GUID \
&(const EFI_GUID) { 0xbc13c2ff, 0x59e6, 0x4262, { 0xa3, 0x52, 0xb2, 0x75, 0xfd, 0x6f, 0x71, 0x72 } }
EFI_STATUS xbootldr_open(EFI_HANDLE *device, EFI_HANDLE *ret_device, EFI_FILE **ret_root_dir);