u-boot/lib/efi_loader/efi_file.c

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/*
* EFI utils
*
* Copyright (c) 2017 Rob Clark
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <charset.h>
#include <efi_loader.h>
#include <malloc.h>
#include <fs.h>
struct file_system {
struct efi_simple_file_system_protocol base;
struct efi_device_path *dp;
struct blk_desc *desc;
int part;
};
#define to_fs(x) container_of(x, struct file_system, base)
struct file_handle {
struct efi_file_handle base;
struct file_system *fs;
loff_t offset; /* current file position/cursor */
int isdir;
/* for reading a directory: */
struct fs_dir_stream *dirs;
struct fs_dirent *dent;
char path[0];
};
#define to_fh(x) container_of(x, struct file_handle, base)
static const struct efi_file_handle efi_file_handle_protocol;
static char *basename(struct file_handle *fh)
{
char *s = strrchr(fh->path, '/');
if (s)
return s + 1;
return fh->path;
}
static int set_blk_dev(struct file_handle *fh)
{
return fs_set_blk_dev_with_part(fh->fs->desc, fh->fs->part);
}
static int is_dir(struct file_handle *fh)
{
struct fs_dir_stream *dirs;
set_blk_dev(fh);
dirs = fs_opendir(fh->path);
if (!dirs)
return 0;
fs_closedir(dirs);
return 1;
}
/*
* Normalize a path which may include either back or fwd slashes,
* double slashes, . or .. entries in the path, etc.
*/
static int sanitize_path(char *path)
{
char *p;
/* backslash to slash: */
p = path;
while ((p = strchr(p, '\\')))
*p++ = '/';
/* handle double-slashes: */
p = path;
while ((p = strstr(p, "//"))) {
char *src = p + 1;
memmove(p, src, strlen(src) + 1);
}
/* handle extra /.'s */
p = path;
while ((p = strstr(p, "/."))) {
/*
* You'd be tempted to do this *after* handling ".."s
* below to avoid having to check if "/." is start of
* a "/..", but that won't have the correct results..
* for example, "/foo/./../bar" would get resolved to
* "/foo/bar" if you did these two passes in the other
* order
*/
if (p[2] == '.') {
p += 2;
continue;
}
char *src = p + 2;
memmove(p, src, strlen(src) + 1);
}
/* handle extra /..'s: */
p = path;
while ((p = strstr(p, "/.."))) {
char *src = p + 3;
p--;
/* find beginning of previous path entry: */
while (true) {
if (p < path)
return -1;
if (*p == '/')
break;
p--;
}
memmove(p, src, strlen(src) + 1);
}
return 0;
}
/* NOTE: despite what you would expect, 'file_name' is actually a path.
* With windoze style backlashes, ofc.
*/
static struct efi_file_handle *file_open(struct file_system *fs,
struct file_handle *parent, s16 *file_name, u64 mode)
{
struct file_handle *fh;
char f0[MAX_UTF8_PER_UTF16] = {0};
int plen = 0;
int flen = 0;
if (file_name) {
utf16_to_utf8((u8 *)f0, (u16 *)file_name, 1);
flen = utf16_strlen((u16 *)file_name);
}
/* we could have a parent, but also an absolute path: */
if (f0[0] == '\\') {
plen = 0;
} else if (parent) {
plen = strlen(parent->path) + 1;
}
/* +2 is for null and '/' */
fh = calloc(1, sizeof(*fh) + plen + (flen * MAX_UTF8_PER_UTF16) + 2);
fh->base = efi_file_handle_protocol;
fh->fs = fs;
if (parent) {
char *p = fh->path;
if (plen > 0) {
strcpy(p, parent->path);
p += plen - 1;
*p++ = '/';
}
utf16_to_utf8((u8 *)p, (u16 *)file_name, flen);
if (sanitize_path(fh->path))
goto error;
/* check if file exists: */
if (set_blk_dev(fh))
goto error;
if (!((mode & EFI_FILE_MODE_CREATE) || fs_exists(fh->path)))
goto error;
/* figure out if file is a directory: */
fh->isdir = is_dir(fh);
} else {
fh->isdir = 1;
strcpy(fh->path, "");
}
return &fh->base;
error:
free(fh);
return NULL;
}
static efi_status_t EFIAPI efi_file_open(struct efi_file_handle *file,
struct efi_file_handle **new_handle,
s16 *file_name, u64 open_mode, u64 attributes)
{
struct file_handle *fh = to_fh(file);
EFI_ENTRY("%p, %p, \"%ls\", %llx, %llu", file, new_handle, file_name,
open_mode, attributes);
*new_handle = file_open(fh->fs, fh, file_name, open_mode);
if (!*new_handle)
return EFI_EXIT(EFI_NOT_FOUND);
return EFI_EXIT(EFI_SUCCESS);
}
static efi_status_t file_close(struct file_handle *fh)
{
fs_closedir(fh->dirs);
free(fh);
return EFI_SUCCESS;
}
static efi_status_t EFIAPI efi_file_close(struct efi_file_handle *file)
{
struct file_handle *fh = to_fh(file);
EFI_ENTRY("%p", file);
return EFI_EXIT(file_close(fh));
}
static efi_status_t EFIAPI efi_file_delete(struct efi_file_handle *file)
{
struct file_handle *fh = to_fh(file);
EFI_ENTRY("%p", file);
file_close(fh);
return EFI_EXIT(EFI_WARN_DELETE_FAILURE);
}
static efi_status_t file_read(struct file_handle *fh, u64 *buffer_size,
void *buffer)
{
loff_t actread;
if (fs_read(fh->path, (ulong)buffer, fh->offset,
*buffer_size, &actread))
return EFI_DEVICE_ERROR;
*buffer_size = actread;
fh->offset += actread;
return EFI_SUCCESS;
}
static efi_status_t dir_read(struct file_handle *fh, u64 *buffer_size,
void *buffer)
{
struct efi_file_info *info = buffer;
struct fs_dirent *dent;
unsigned int required_size;
if (!fh->dirs) {
assert(fh->offset == 0);
fh->dirs = fs_opendir(fh->path);
if (!fh->dirs)
return EFI_DEVICE_ERROR;
}
/*
* So this is a bit awkward. Since fs layer is stateful and we
* can't rewind an entry, in the EFI_BUFFER_TOO_SMALL case below
* we might have to return without consuming the dent.. so we
* have to stash it for next call.
*/
if (fh->dent) {
dent = fh->dent;
fh->dent = NULL;
} else {
dent = fs_readdir(fh->dirs);
}
if (!dent) {
/* no more files in directory: */
/* workaround shim.efi bug/quirk.. as find_boot_csv()
* loops through directory contents, it initially calls
* read w/ zero length buffer to find out how much mem
* to allocate for the EFI_FILE_INFO, then allocates,
* and then calls a 2nd time. If we return size of
* zero the first time, it happily passes that to
* AllocateZeroPool(), and when that returns NULL it
* thinks it is EFI_OUT_OF_RESOURCES. So on first
* call return a non-zero size:
*/
if (*buffer_size == 0)
*buffer_size = sizeof(*info);
else
*buffer_size = 0;
return EFI_SUCCESS;
}
/* check buffer size: */
required_size = sizeof(*info) + 2 * (strlen(dent->name) + 1);
if (*buffer_size < required_size) {
*buffer_size = required_size;
fh->dent = dent;
return EFI_BUFFER_TOO_SMALL;
}
*buffer_size = required_size;
memset(info, 0, required_size);
info->size = required_size;
info->file_size = dent->size;
info->physical_size = dent->size;
if (dent->type == FS_DT_DIR)
info->attribute |= EFI_FILE_DIRECTORY;
ascii2unicode((u16 *)info->file_name, dent->name);
fh->offset++;
return EFI_SUCCESS;
}
static efi_status_t EFIAPI efi_file_read(struct efi_file_handle *file,
u64 *buffer_size, void *buffer)
{
struct file_handle *fh = to_fh(file);
efi_status_t ret = EFI_SUCCESS;
EFI_ENTRY("%p, %p, %p", file, buffer_size, buffer);
if (set_blk_dev(fh)) {
ret = EFI_DEVICE_ERROR;
goto error;
}
if (fh->isdir)
ret = dir_read(fh, buffer_size, buffer);
else
ret = file_read(fh, buffer_size, buffer);
error:
return EFI_EXIT(ret);
}
static efi_status_t EFIAPI efi_file_write(struct efi_file_handle *file,
u64 *buffer_size, void *buffer)
{
struct file_handle *fh = to_fh(file);
efi_status_t ret = EFI_SUCCESS;
loff_t actwrite;
EFI_ENTRY("%p, %p, %p", file, buffer_size, buffer);
if (set_blk_dev(fh)) {
ret = EFI_DEVICE_ERROR;
goto error;
}
if (fs_write(fh->path, (ulong)buffer, fh->offset, *buffer_size,
&actwrite)) {
ret = EFI_DEVICE_ERROR;
goto error;
}
*buffer_size = actwrite;
fh->offset += actwrite;
error:
return EFI_EXIT(ret);
}
static efi_status_t EFIAPI efi_file_getpos(struct efi_file_handle *file,
u64 *pos)
{
struct file_handle *fh = to_fh(file);
EFI_ENTRY("%p, %p", file, pos);
*pos = fh->offset;
return EFI_EXIT(EFI_SUCCESS);
}
static efi_status_t EFIAPI efi_file_setpos(struct efi_file_handle *file,
u64 pos)
{
struct file_handle *fh = to_fh(file);
efi_status_t ret = EFI_SUCCESS;
EFI_ENTRY("%p, %llu", file, pos);
if (fh->isdir) {
if (pos != 0) {
ret = EFI_UNSUPPORTED;
goto error;
}
fs_closedir(fh->dirs);
fh->dirs = NULL;
}
if (pos == ~0ULL) {
loff_t file_size;
if (set_blk_dev(fh)) {
ret = EFI_DEVICE_ERROR;
goto error;
}
if (fs_size(fh->path, &file_size)) {
ret = EFI_DEVICE_ERROR;
goto error;
}
pos = file_size;
}
fh->offset = pos;
error:
return EFI_EXIT(ret);
}
static efi_status_t EFIAPI efi_file_getinfo(struct efi_file_handle *file,
efi_guid_t *info_type, u64 *buffer_size, void *buffer)
{
struct file_handle *fh = to_fh(file);
efi_status_t ret = EFI_SUCCESS;
EFI_ENTRY("%p, %p, %p, %p", file, info_type, buffer_size, buffer);
if (!guidcmp(info_type, &efi_file_info_guid)) {
struct efi_file_info *info = buffer;
char *filename = basename(fh);
unsigned int required_size;
loff_t file_size;
/* check buffer size: */
required_size = sizeof(*info) + 2 * (strlen(filename) + 1);
if (*buffer_size < required_size) {
*buffer_size = required_size;
ret = EFI_BUFFER_TOO_SMALL;
goto error;
}
if (set_blk_dev(fh)) {
ret = EFI_DEVICE_ERROR;
goto error;
}
if (fs_size(fh->path, &file_size)) {
ret = EFI_DEVICE_ERROR;
goto error;
}
memset(info, 0, required_size);
info->size = required_size;
info->file_size = file_size;
info->physical_size = file_size;
if (fh->isdir)
info->attribute |= EFI_FILE_DIRECTORY;
ascii2unicode((u16 *)info->file_name, filename);
} else {
ret = EFI_UNSUPPORTED;
}
error:
return EFI_EXIT(ret);
}
static efi_status_t EFIAPI efi_file_setinfo(struct efi_file_handle *file,
efi_guid_t *info_type, u64 buffer_size, void *buffer)
{
EFI_ENTRY("%p, %p, %llu, %p", file, info_type, buffer_size, buffer);
return EFI_EXIT(EFI_UNSUPPORTED);
}
static efi_status_t EFIAPI efi_file_flush(struct efi_file_handle *file)
{
EFI_ENTRY("%p", file);
return EFI_EXIT(EFI_SUCCESS);
}
static const struct efi_file_handle efi_file_handle_protocol = {
.rev = EFI_FILE_PROTOCOL_REVISION,
.open = efi_file_open,
.close = efi_file_close,
.delete = efi_file_delete,
.read = efi_file_read,
.write = efi_file_write,
.getpos = efi_file_getpos,
.setpos = efi_file_setpos,
.getinfo = efi_file_getinfo,
.setinfo = efi_file_setinfo,
.flush = efi_file_flush,
};
struct efi_file_handle *efi_file_from_path(struct efi_device_path *fp)
{
struct efi_simple_file_system_protocol *v;
struct efi_file_handle *f;
efi_status_t ret;
v = efi_fs_from_path(fp);
if (!v)
return NULL;
EFI_CALL(ret = v->open_volume(v, &f));
if (ret != EFI_SUCCESS)
return NULL;
/* skip over device-path nodes before the file path: */
while (fp && !EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH))
fp = efi_dp_next(fp);
while (fp) {
struct efi_device_path_file_path *fdp =
container_of(fp, struct efi_device_path_file_path, dp);
struct efi_file_handle *f2;
if (!EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH)) {
printf("bad file path!\n");
f->close(f);
return NULL;
}
EFI_CALL(ret = f->open(f, &f2, (s16 *)fdp->str,
EFI_FILE_MODE_READ, 0));
if (ret != EFI_SUCCESS)
return NULL;
fp = efi_dp_next(fp);
EFI_CALL(f->close(f));
f = f2;
}
return f;
}
static efi_status_t EFIAPI
efi_open_volume(struct efi_simple_file_system_protocol *this,
struct efi_file_handle **root)
{
struct file_system *fs = to_fs(this);
EFI_ENTRY("%p, %p", this, root);
*root = file_open(fs, NULL, NULL, 0);
return EFI_EXIT(EFI_SUCCESS);
}
struct efi_simple_file_system_protocol *
efi_simple_file_system(struct blk_desc *desc, int part,
struct efi_device_path *dp)
{
struct file_system *fs;
fs = calloc(1, sizeof(*fs));
fs->base.rev = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION;
fs->base.open_volume = efi_open_volume;
fs->desc = desc;
fs->part = part;
fs->dp = dp;
return &fs->base;
}