grub/grub-core/loader/linux.c
Vladimir Serbinenko ca0a4f689a verifiers: File type for fine-grained signature-verification controlling
Let's provide file type info to the I/O layer. This way verifiers
framework and its users will be able to differentiate files and verify
only required ones.

This is preparatory patch.

Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Ross Philipson <ross.philipson@oracle.com>
2018-11-09 13:25:31 +01:00

302 lines
6.6 KiB
C

#include <grub/types.h>
#include <grub/err.h>
#include <grub/linux.h>
#include <grub/misc.h>
#include <grub/file.h>
#include <grub/mm.h>
struct newc_head
{
char magic[6];
char ino[8];
char mode[8];
char uid[8];
char gid[8];
char nlink[8];
char mtime[8];
char filesize[8];
char devmajor[8];
char devminor[8];
char rdevmajor[8];
char rdevminor[8];
char namesize[8];
char check[8];
} GRUB_PACKED;
struct grub_linux_initrd_component
{
grub_file_t file;
char *newc_name;
grub_off_t size;
};
struct dir
{
char *name;
struct dir *next;
struct dir *child;
};
static char
hex (grub_uint8_t val)
{
if (val < 10)
return '0' + val;
return 'a' + val - 10;
}
static void
set_field (char *var, grub_uint32_t val)
{
int i;
char *ptr = var;
for (i = 28; i >= 0; i -= 4)
*ptr++ = hex((val >> i) & 0xf);
}
static grub_uint8_t *
make_header (grub_uint8_t *ptr,
const char *name, grub_size_t len,
grub_uint32_t mode,
grub_off_t fsize)
{
struct newc_head *head = (struct newc_head *) ptr;
grub_uint8_t *optr;
grub_size_t oh = 0;
grub_memcpy (head->magic, "070701", 6);
set_field (head->ino, 0);
set_field (head->mode, mode);
set_field (head->uid, 0);
set_field (head->gid, 0);
set_field (head->nlink, 1);
set_field (head->mtime, 0);
set_field (head->filesize, fsize);
set_field (head->devmajor, 0);
set_field (head->devminor, 0);
set_field (head->rdevmajor, 0);
set_field (head->rdevminor, 0);
set_field (head->namesize, len);
set_field (head->check, 0);
optr = ptr;
ptr += sizeof (struct newc_head);
grub_memcpy (ptr, name, len);
ptr += len;
oh = ALIGN_UP_OVERHEAD (ptr - optr, 4);
grub_memset (ptr, 0, oh);
ptr += oh;
return ptr;
}
static void
free_dir (struct dir *root)
{
if (!root)
return;
free_dir (root->next);
free_dir (root->child);
grub_free (root->name);
grub_free (root);
}
static grub_size_t
insert_dir (const char *name, struct dir **root,
grub_uint8_t *ptr)
{
struct dir *cur, **head = root;
const char *cb, *ce = name;
grub_size_t size = 0;
while (1)
{
for (cb = ce; *cb == '/'; cb++);
for (ce = cb; *ce && *ce != '/'; ce++);
if (!*ce)
break;
for (cur = *root; cur; cur = cur->next)
if (grub_memcmp (cur->name, cb, ce - cb)
&& cur->name[ce - cb] == 0)
break;
if (!cur)
{
struct dir *n;
n = grub_zalloc (sizeof (*n));
if (!n)
return 0;
n->next = *head;
n->name = grub_strndup (cb, ce - cb);
if (ptr)
{
grub_dprintf ("linux", "Creating directory %s, %s\n", name, ce);
ptr = make_header (ptr, name, ce - name,
040777, 0);
}
size += ALIGN_UP ((ce - (char *) name)
+ sizeof (struct newc_head), 4);
*head = n;
cur = n;
}
root = &cur->next;
}
return size;
}
grub_err_t
grub_initrd_init (int argc, char *argv[],
struct grub_linux_initrd_context *initrd_ctx)
{
int i;
int newc = 0;
struct dir *root = 0;
initrd_ctx->nfiles = 0;
initrd_ctx->components = 0;
initrd_ctx->components = grub_zalloc (argc
* sizeof (initrd_ctx->components[0]));
if (!initrd_ctx->components)
return grub_errno;
initrd_ctx->size = 0;
for (i = 0; i < argc; i++)
{
const char *fname = argv[i];
initrd_ctx->size = ALIGN_UP (initrd_ctx->size, 4);
if (grub_memcmp (argv[i], "newc:", 5) == 0)
{
const char *ptr, *eptr;
ptr = argv[i] + 5;
while (*ptr == '/')
ptr++;
eptr = grub_strchr (ptr, ':');
if (eptr)
{
initrd_ctx->components[i].newc_name = grub_strndup (ptr, eptr - ptr);
if (!initrd_ctx->components[i].newc_name)
{
grub_initrd_close (initrd_ctx);
return grub_errno;
}
initrd_ctx->size
+= ALIGN_UP (sizeof (struct newc_head)
+ grub_strlen (initrd_ctx->components[i].newc_name),
4);
initrd_ctx->size += insert_dir (initrd_ctx->components[i].newc_name,
&root, 0);
newc = 1;
fname = eptr + 1;
}
}
else if (newc)
{
initrd_ctx->size += ALIGN_UP (sizeof (struct newc_head)
+ sizeof ("TRAILER!!!") - 1, 4);
free_dir (root);
root = 0;
newc = 0;
}
initrd_ctx->components[i].file = grub_file_open (fname,
GRUB_FILE_TYPE_LINUX_INITRD
| GRUB_FILE_TYPE_NO_DECOMPRESS);
if (!initrd_ctx->components[i].file)
{
grub_initrd_close (initrd_ctx);
return grub_errno;
}
initrd_ctx->nfiles++;
initrd_ctx->components[i].size
= grub_file_size (initrd_ctx->components[i].file);
initrd_ctx->size += initrd_ctx->components[i].size;
}
if (newc)
{
initrd_ctx->size = ALIGN_UP (initrd_ctx->size, 4);
initrd_ctx->size += ALIGN_UP (sizeof (struct newc_head)
+ sizeof ("TRAILER!!!") - 1, 4);
free_dir (root);
root = 0;
}
return GRUB_ERR_NONE;
}
grub_size_t
grub_get_initrd_size (struct grub_linux_initrd_context *initrd_ctx)
{
return initrd_ctx->size;
}
void
grub_initrd_close (struct grub_linux_initrd_context *initrd_ctx)
{
int i;
if (!initrd_ctx->components)
return;
for (i = 0; i < initrd_ctx->nfiles; i++)
{
grub_free (initrd_ctx->components[i].newc_name);
grub_file_close (initrd_ctx->components[i].file);
}
grub_free (initrd_ctx->components);
initrd_ctx->components = 0;
}
grub_err_t
grub_initrd_load (struct grub_linux_initrd_context *initrd_ctx,
char *argv[], void *target)
{
grub_uint8_t *ptr = target;
int i;
int newc = 0;
struct dir *root = 0;
grub_ssize_t cursize = 0;
for (i = 0; i < initrd_ctx->nfiles; i++)
{
grub_memset (ptr, 0, ALIGN_UP_OVERHEAD (cursize, 4));
ptr += ALIGN_UP_OVERHEAD (cursize, 4);
if (initrd_ctx->components[i].newc_name)
{
ptr += insert_dir (initrd_ctx->components[i].newc_name,
&root, ptr);
ptr = make_header (ptr, initrd_ctx->components[i].newc_name,
grub_strlen (initrd_ctx->components[i].newc_name),
0100777,
initrd_ctx->components[i].size);
newc = 1;
}
else if (newc)
{
ptr = make_header (ptr, "TRAILER!!!", sizeof ("TRAILER!!!") - 1,
0, 0);
free_dir (root);
root = 0;
newc = 0;
}
cursize = initrd_ctx->components[i].size;
if (grub_file_read (initrd_ctx->components[i].file, ptr, cursize)
!= cursize)
{
if (!grub_errno)
grub_error (GRUB_ERR_FILE_READ_ERROR, N_("premature end of file %s"),
argv[i]);
grub_initrd_close (initrd_ctx);
return grub_errno;
}
ptr += cursize;
}
if (newc)
{
grub_memset (ptr, 0, ALIGN_UP_OVERHEAD (cursize, 4));
ptr += ALIGN_UP_OVERHEAD (cursize, 4);
ptr = make_header (ptr, "TRAILER!!!", sizeof ("TRAILER!!!") - 1, 0, 0);
}
free_dir (root);
root = 0;
return GRUB_ERR_NONE;
}