u-boot/lib/efi_loader/efi_disk.c
Alexander Graf 0812d1a094 efi_loader: disk: Sanitize exposed devices
When a target device is 0 bytes long, there's no point in exposing it to
the user. Let's just skip them.

Also, when an offset is passed into the efi disk creation, we should
remove this offset from the total number of sectors we can handle.

This patch fixes both things.

Signed-off-by: Alexander Graf <agraf@suse.de>
2016-08-08 13:33:00 -04:00

349 lines
9.2 KiB
C

/*
* EFI application disk support
*
* Copyright (c) 2016 Alexander Graf
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <blk.h>
#include <dm.h>
#include <efi_loader.h>
#include <inttypes.h>
#include <part.h>
#include <malloc.h>
static const efi_guid_t efi_block_io_guid = BLOCK_IO_GUID;
struct efi_disk_obj {
/* Generic EFI object parent class data */
struct efi_object parent;
/* EFI Interface callback struct for block I/O */
struct efi_block_io ops;
/* U-Boot ifname for block device */
const char *ifname;
/* U-Boot dev_index for block device */
int dev_index;
/* EFI Interface Media descriptor struct, referenced by ops */
struct efi_block_io_media media;
/* EFI device path to this block device */
struct efi_device_path_file_path *dp;
/* Offset into disk for simple partitions */
lbaint_t offset;
/* Internal block device */
const struct blk_desc *desc;
};
static efi_status_t efi_disk_open_block(void *handle, efi_guid_t *protocol,
void **protocol_interface, void *agent_handle,
void *controller_handle, uint32_t attributes)
{
struct efi_disk_obj *diskobj = handle;
*protocol_interface = &diskobj->ops;
return EFI_SUCCESS;
}
static efi_status_t efi_disk_open_dp(void *handle, efi_guid_t *protocol,
void **protocol_interface, void *agent_handle,
void *controller_handle, uint32_t attributes)
{
struct efi_disk_obj *diskobj = handle;
*protocol_interface = diskobj->dp;
return EFI_SUCCESS;
}
static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
char extended_verification)
{
EFI_ENTRY("%p, %x", this, extended_verification);
return EFI_EXIT(EFI_DEVICE_ERROR);
}
enum efi_disk_direction {
EFI_DISK_READ,
EFI_DISK_WRITE,
};
static efi_status_t EFIAPI efi_disk_rw_blocks(struct efi_block_io *this,
u32 media_id, u64 lba, unsigned long buffer_size,
void *buffer, enum efi_disk_direction direction)
{
struct efi_disk_obj *diskobj;
struct blk_desc *desc;
int blksz;
int blocks;
unsigned long n;
diskobj = container_of(this, struct efi_disk_obj, ops);
desc = (struct blk_desc *) diskobj->desc;
blksz = desc->blksz;
blocks = buffer_size / blksz;
lba += diskobj->offset;
debug("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
__LINE__, blocks, lba, blksz, direction);
/* We only support full block access */
if (buffer_size & (blksz - 1))
return EFI_EXIT(EFI_DEVICE_ERROR);
if (direction == EFI_DISK_READ)
n = blk_dread(desc, lba, blocks, buffer);
else
n = blk_dwrite(desc, lba, blocks, buffer);
/* We don't do interrupts, so check for timers cooperatively */
efi_timer_check();
debug("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
if (n != blocks)
return EFI_EXIT(EFI_DEVICE_ERROR);
return EFI_EXIT(EFI_SUCCESS);
}
static efi_status_t efi_disk_read_blocks(struct efi_block_io *this,
u32 media_id, u64 lba, unsigned long buffer_size,
void *buffer)
{
void *real_buffer = buffer;
efi_status_t r;
#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
r = efi_disk_read_blocks(this, media_id, lba,
EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
if (r != EFI_SUCCESS)
return r;
return efi_disk_read_blocks(this, media_id, lba +
EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
}
real_buffer = efi_bounce_buffer;
#endif
EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
buffer_size, buffer);
r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
EFI_DISK_READ);
/* Copy from bounce buffer to real buffer if necessary */
if ((r == EFI_SUCCESS) && (real_buffer != buffer))
memcpy(buffer, real_buffer, buffer_size);
return EFI_EXIT(r);
}
static efi_status_t efi_disk_write_blocks(struct efi_block_io *this,
u32 media_id, u64 lba, unsigned long buffer_size,
void *buffer)
{
void *real_buffer = buffer;
efi_status_t r;
#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
r = efi_disk_write_blocks(this, media_id, lba,
EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
if (r != EFI_SUCCESS)
return r;
return efi_disk_write_blocks(this, media_id, lba +
EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
}
real_buffer = efi_bounce_buffer;
#endif
EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
buffer_size, buffer);
/* Populate bounce buffer if necessary */
if (real_buffer != buffer)
memcpy(real_buffer, buffer, buffer_size);
r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
EFI_DISK_WRITE);
return EFI_EXIT(r);
}
static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
{
/* We always write synchronously */
EFI_ENTRY("%p", this);
return EFI_EXIT(EFI_SUCCESS);
}
static const struct efi_block_io block_io_disk_template = {
.reset = &efi_disk_reset,
.read_blocks = &efi_disk_read_blocks,
.write_blocks = &efi_disk_write_blocks,
.flush_blocks = &efi_disk_flush_blocks,
};
static void efi_disk_add_dev(const char *name,
const char *if_typename,
const struct blk_desc *desc,
int dev_index,
lbaint_t offset)
{
struct efi_disk_obj *diskobj;
struct efi_device_path_file_path *dp;
int objlen = sizeof(*diskobj) + (sizeof(*dp) * 2);
/* Don't add empty devices */
if (!desc->lba)
return;
diskobj = calloc(1, objlen);
/* Fill in object data */
diskobj->parent.protocols[0].guid = &efi_block_io_guid;
diskobj->parent.protocols[0].open = efi_disk_open_block;
diskobj->parent.protocols[1].guid = &efi_guid_device_path;
diskobj->parent.protocols[1].open = efi_disk_open_dp;
diskobj->parent.handle = diskobj;
diskobj->ops = block_io_disk_template;
diskobj->ifname = if_typename;
diskobj->dev_index = dev_index;
diskobj->offset = offset;
diskobj->desc = desc;
/* Fill in EFI IO Media info (for read/write callbacks) */
diskobj->media.removable_media = desc->removable;
diskobj->media.media_present = 1;
diskobj->media.block_size = desc->blksz;
diskobj->media.io_align = desc->blksz;
diskobj->media.last_block = desc->lba - offset;
diskobj->ops.media = &diskobj->media;
/* Fill in device path */
dp = (void*)&diskobj[1];
diskobj->dp = dp;
dp[0].dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
dp[0].dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
dp[0].dp.length = sizeof(*dp);
ascii2unicode(dp[0].str, name);
dp[1].dp.type = DEVICE_PATH_TYPE_END;
dp[1].dp.sub_type = DEVICE_PATH_SUB_TYPE_END;
dp[1].dp.length = sizeof(*dp);
/* Hook up to the device list */
list_add_tail(&diskobj->parent.link, &efi_obj_list);
}
static int efi_disk_create_eltorito(struct blk_desc *desc,
const char *if_typename,
int diskid,
const char *pdevname)
{
int disks = 0;
#ifdef CONFIG_ISO_PARTITION
char devname[32] = { 0 }; /* dp->str is u16[32] long */
disk_partition_t info;
int part = 1;
if (desc->part_type != PART_TYPE_ISO)
return 0;
while (!part_get_info(desc, part, &info)) {
snprintf(devname, sizeof(devname), "%s:%d", pdevname,
part);
efi_disk_add_dev(devname, if_typename, desc, diskid,
info.start);
part++;
disks++;
}
#endif
return disks;
}
/*
* U-Boot doesn't have a list of all online disk devices. So when running our
* EFI payload, we scan through all of the potentially available ones and
* store them in our object pool.
*
* TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
* Consider converting the code to look up devices as needed. The EFI device
* could be a child of the UCLASS_BLK block device, perhaps.
*
* This gets called from do_bootefi_exec().
*/
int efi_disk_register(void)
{
int disks = 0;
#ifdef CONFIG_BLK
struct udevice *dev;
for (uclass_first_device(UCLASS_BLK, &dev);
dev;
uclass_next_device(&dev)) {
struct blk_desc *desc = dev_get_uclass_platdata(dev);
const char *if_typename = dev->driver->name;
printf("Scanning disk %s...\n", dev->name);
efi_disk_add_dev(dev->name, if_typename, desc, desc->devnum, 0);
disks++;
/*
* El Torito images show up as block devices in an EFI world,
* so let's create them here
*/
disks += efi_disk_create_eltorito(desc, if_typename,
desc->devnum, dev->name);
}
#else
int i, if_type;
/* Search for all available disk devices */
for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
const struct blk_driver *cur_drvr;
const char *if_typename;
cur_drvr = blk_driver_lookup_type(if_type);
if (!cur_drvr)
continue;
if_typename = cur_drvr->if_typename;
printf("Scanning disks on %s...\n", if_typename);
for (i = 0; i < 4; i++) {
struct blk_desc *desc;
char devname[32] = { 0 }; /* dp->str is u16[32] long */
desc = blk_get_devnum_by_type(if_type, i);
if (!desc)
continue;
if (desc->type == DEV_TYPE_UNKNOWN)
continue;
snprintf(devname, sizeof(devname), "%s%d",
if_typename, i);
efi_disk_add_dev(devname, if_typename, desc, i, 0);
disks++;
/*
* El Torito images show up as block devices
* in an EFI world, so let's create them here
*/
disks += efi_disk_create_eltorito(desc, if_typename,
i, devname);
}
}
#endif
printf("Found %d disks\n", disks);
return 0;
}