coreboot-kgpe-d16/payloads/libpayload/libcbfs/cbfs.c

237 lines
5.8 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause */
#include <libpayload-config.h>
#include <arch/virtual.h>
#include <assert.h>
#include <cbfs.h>
#include <cbfs_glue.h>
#include <commonlib/bsd/cbfs_private.h>
#include <commonlib/bsd/fmap_serialized.h>
#include <libpayload.h>
#include <lz4.h>
#include <lzma.h>
#include <string.h>
#include <sysinfo.h>
static const struct cbfs_boot_device *cbfs_get_boot_device(bool force_ro)
{
static struct cbfs_boot_device ro;
static struct cbfs_boot_device rw;
if (!force_ro) {
if (!rw.dev.size) {
rw.dev.offset = lib_sysinfo.cbfs_offset;
rw.dev.size = lib_sysinfo.cbfs_size;
rw.mcache = phys_to_virt(lib_sysinfo.cbfs_rw_mcache_offset);
rw.mcache_size = lib_sysinfo.cbfs_rw_mcache_size;
}
return &rw;
}
if (ro.dev.size)
return &ro;
if (fmap_locate_area("COREBOOT", &ro.dev.offset, &ro.dev.size))
return NULL;
ro.mcache = phys_to_virt(lib_sysinfo.cbfs_ro_mcache_offset);
ro.mcache_size = lib_sysinfo.cbfs_ro_mcache_size;
return &ro;
}
ssize_t _cbfs_boot_lookup(const char *name, bool force_ro, union cbfs_mdata *mdata)
{
const struct cbfs_boot_device *cbd = cbfs_get_boot_device(force_ro);
if (!cbd)
return CB_ERR;
size_t data_offset;
enum cb_err err = CB_CBFS_CACHE_FULL;
if (cbd->mcache_size)
err = cbfs_mcache_lookup(cbd->mcache, cbd->mcache_size, name, mdata,
&data_offset);
if (err == CB_CBFS_CACHE_FULL)
err = cbfs_lookup(&cbd->dev, name, mdata, &data_offset, NULL);
/* Fallback to RO if possible. */
if (CONFIG(LP_ENABLE_CBFS_FALLBACK) && !force_ro && err == CB_CBFS_NOT_FOUND) {
LOG("Fall back to RO region for '%s'\n", name);
return _cbfs_boot_lookup(name, true, mdata);
}
if (err) {
if (err == CB_CBFS_NOT_FOUND)
LOG("'%s' not found.\n", name);
else
ERROR("Error %d when looking up '%s'\n", err, name);
return err;
}
return cbd->dev.offset + data_offset;
}
void cbfs_unmap(void *mapping)
{
free(mapping);
}
static bool cbfs_file_hash_mismatch(const void *buffer, size_t size,
const union cbfs_mdata *mdata, bool skip_verification)
{
if (!CONFIG(LP_CBFS_VERIFICATION) || skip_verification)
return false;
const struct vb2_hash *hash = cbfs_file_hash(mdata);
if (!hash) {
ERROR("'%s' does not have a file hash!\n", mdata->h.filename);
return true;
}
if (vb2_hash_verify(cbfs_hwcrypto_allowed(), buffer, size, hash) != VB2_SUCCESS) {
ERROR("'%s' file hash mismatch!\n", mdata->h.filename);
return true;
}
return false;
}
static size_t cbfs_load_and_decompress(size_t offset, size_t in_size, void *buffer,
size_t buffer_size, uint32_t compression,
const union cbfs_mdata *mdata, bool skip_verification)
{
void *load = buffer;
size_t out_size = 0;
DEBUG("Decompressing %zu bytes from '%s' to %p with algo %d\n", in_size,
mdata->h.filename, buffer, compression);
if (compression != CBFS_COMPRESS_NONE) {
load = malloc(in_size);
if (!load) {
ERROR("'%s' buffer allocation failed\n", mdata->h.filename);
return 0;
}
}
if (boot_device_read(load, offset, in_size) != in_size) {
ERROR("'%s' failed to read contents of file\n", mdata->h.filename);
goto out;
}
if (cbfs_file_hash_mismatch(load, in_size, mdata, skip_verification))
goto out;
switch (compression) {
case CBFS_COMPRESS_NONE:
out_size = in_size;
break;
case CBFS_COMPRESS_LZ4:
if (!CONFIG(LP_LZ4))
goto out;
out_size = ulz4fn(load, in_size, buffer, buffer_size);
break;
case CBFS_COMPRESS_LZMA:
if (!CONFIG(LP_LZMA))
goto out;
out_size = ulzman(load, in_size, buffer, buffer_size);
break;
default:
ERROR("'%s' decompression algo %d not supported\n", mdata->h.filename,
compression);
}
out:
if (load != buffer)
free(load);
return out_size;
}
static void *do_load(union cbfs_mdata *mdata, ssize_t offset, void *buf, size_t *size_inout,
bool skip_verification)
{
bool malloced = false;
size_t buf_size = 0;
size_t out_size;
uint32_t compression = CBFS_COMPRESS_NONE;
const struct cbfs_file_attr_compression *cattr =
cbfs_find_attr(mdata, CBFS_FILE_ATTR_TAG_COMPRESSION, sizeof(*cattr));
if (cattr) {
compression = be32toh(cattr->compression);
out_size = be32toh(cattr->decompressed_size);
} else {
out_size = be32toh(mdata->h.len);
}
if (size_inout) {
buf_size = *size_inout;
*size_inout = out_size;
}
if (buf) {
if (!size_inout || buf_size < out_size) {
ERROR("'%s' buffer too small\n", mdata->h.filename);
return NULL;
}
} else {
buf = malloc(out_size);
if (!buf) {
ERROR("'%s' allocation failure\n", mdata->h.filename);
return NULL;
}
malloced = true;
}
if (cbfs_load_and_decompress(offset, be32toh(mdata->h.len), buf, out_size, compression,
mdata, skip_verification)
!= out_size) {
if (malloced)
free(buf);
return NULL;
}
return buf;
}
void *_cbfs_load(const char *name, void *buf, size_t *size_inout, bool force_ro)
{
ssize_t offset;
union cbfs_mdata mdata;
DEBUG("%s(name='%s', buf=%p, force_ro=%s)\n", __func__, name, buf,
force_ro ? "true" : "false");
offset = _cbfs_boot_lookup(name, force_ro, &mdata);
if (offset < 0)
return NULL;
return do_load(&mdata, offset, buf, size_inout, false);
}
void *_cbfs_unverified_area_load(const char *area, const char *name, void *buf,
size_t *size_inout)
{
struct cbfs_dev dev;
union cbfs_mdata mdata;
size_t data_offset;
DEBUG("%s(area='%s', name='%s', buf=%p)\n", __func__, area, name, buf);
if (fmap_locate_area(area, &dev.offset, &dev.size) != CB_SUCCESS)
return NULL;
if (cbfs_lookup(&dev, name, &mdata, &data_offset, NULL)) {
ERROR("'%s' not found in '%s'\n", name, area);
return NULL;
}
return do_load(&mdata, dev.offset + data_offset, buf, size_inout, true);
}
/* This should be overridden by payloads that want to enforce more explicit
policy on using HW crypto. */
__weak bool cbfs_hwcrypto_allowed(void)
{
return true;
}