image.h File Reference

Executable images. More...

#include <ipxe/tables.h>
#include <ipxe/list.h>
#include <ipxe/refcnt.h>

Go to the source code of this file.

Data Structures
struct	image
	An executable image. More...
struct	image_type
	An executable image type. More...
struct	image_tag
	An image tag. More...

Macros
#define	IMAGE_REGISTERED   0x0001
	Image is registered.
#define	IMAGE_TRUSTED   0x0002
	Image is trusted.
#define	IMAGE_AUTO_UNREGISTER   0x0004
	Image will be automatically unregistered after execution.
#define	IMAGE_HIDDEN   0x0008
	Image will be hidden from enumeration.
#define	IMAGE_STATIC   0x0010
	Image is statically allocated.
#define	IMAGE_STATIC_NAME   0x0020
	Image name is statically allocated.
#define	PROBE_MULTIBOOT   01
	Multiboot image probe priority.
#define	PROBE_NORMAL   02
	Normal image probe priority.
#define	PROBE_PXE   03
	PXE image probe priority.
#define	IMAGE_TYPES   __table ( struct image_type, "image_types" )
	Executable image type table.
#define	__image_type(probe_order)
	An executable image type.
#define	IMAGE_TAGS   __table ( struct image_tag, "image_tags" )
	Image tag table.
#define	__image_tag   __table_entry ( IMAGE_TAGS, 01 )
	An image tag.
#define	for_each_image(image)
	Iterate over all registered images.
#define	for_each_image_safe(image, tmp)
	Iterate over all registered images, safe against deletion.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
	FILE_SECBOOT (PERMITTED)
static struct image *	first_image (void)
	Retrieve first image.
void	free_image (struct refcnt *refcnt)
	Free executable image.
struct image *	alloc_image (struct uri *uri)
	Allocate executable image.
int	image_set_uri (struct image *image, struct uri *uri)
	Set image URI.
int	image_set_name (struct image *image, const char *name)
	Set image name.
char *	image_strip_suffix (struct image *image)
	Strip dot suffix from image name, if present.
int	image_set_cmdline (struct image *image, const char *cmdline)
	Set image command line.
int	image_set_len (struct image *image, size_t len)
	Set image length.
int	image_set_data (struct image *image, const void *data, size_t len)
	Set image data.
int	register_image (struct image *image)
	Register executable image.
void	unregister_image (struct image *image)
	Unregister executable image.
struct image *	find_image (const char *name)
	Find image by name.
struct image *	find_image_tag (struct image_tag *tag)
	Find image by tag.
int	image_exec (struct image *image)
	Execute image.
int	image_replace (struct image *replacement)
	Set replacement image.
int	image_select (struct image *image)
	Select image for execution.
int	image_set_trust (int require_trusted, int permanent)
	Change image trust requirement.
struct image *	image_memory (const char *name, const void *data, size_t len)
	Create registered image from block of memory.
const char *	image_argument (struct image *image, const char *key)
	Find argument within image command line.
int	image_pixbuf (struct image *image, struct pixel_buffer **pixbuf)
	Create pixel buffer from image.
int	image_asn1 (struct image *image, size_t offset, struct asn1_cursor **cursor)
	Extract ASN.1 object from image.
int	image_extract (struct image *image, const char *name, struct image **extracted)
	Extract archive image.
int	image_extract_exec (struct image *image)
	Extract and execute image.
static struct image *	image_get (struct image *image)
	Increment reference count on an image.
static void	image_put (struct image *image)
	Decrement reference count on an image.
static void	image_clear_cmdline (struct image *image)
	Clear image command line.
static void	image_trust (struct image *image)
	Set image as trusted.
static void	image_untrust (struct image *image)
	Set image as untrusted.
static void	image_hide (struct image *image)
	Mark image as hidden.
static struct image *	image_tag (struct image *image, struct image_tag *tag)
	Tag image.

Variables
struct list_head	images
	List of registered images.
struct image_tag	current_image
struct image_tag	selected_image
const char	empty_image_data []
	Empty image terminating NUL.

Detailed Description

Executable images.

Definition in file image.h.

Macro Definition Documentation

IMAGE_REGISTERED

#define IMAGE_REGISTERED   0x0001

Image is registered.

Definition at line 84 of file image.h.

Referenced by cms_decrypt(), image_exec(), image_replace(), register_image(), and unregister_image().

IMAGE_TRUSTED

#define IMAGE_TRUSTED   0x0002

Image is trusted.

Definition at line 87 of file image.h.

Referenced by cms_verify_fail_okx(), cms_verify_okx(), image_exec(), image_extract(), image_trust(), image_untrust(), and imgstat().

IMAGE_AUTO_UNREGISTER

#define IMAGE_AUTO_UNREGISTER   0x0004

Image will be automatically unregistered after execution.

Definition at line 90 of file image.h.

Referenced by image_exec(), image_extract_exec(), imgsingle_exec(), imgstat(), and uriboot().

IMAGE_HIDDEN

#define IMAGE_HIDDEN   0x0008

Image will be hidden from enumeration.

Definition at line 93 of file image.h.

Referenced by efi_file_install(), efi_file_read_dir(), efi_file_read_initrd(), efi_image_exec(), image_hide(), imgstat(), initrd_load(), and multiboot_add_modules().

IMAGE_STATIC

#define IMAGE_STATIC   0x0010

Image is statically allocated.

Definition at line 96 of file image.h.

Referenced by free_image(), image_set_len(), lkrn_exec(), and register_image().

IMAGE_STATIC_NAME

#define IMAGE_STATIC_NAME   0x0020

Image name is statically allocated.

Definition at line 99 of file image.h.

Referenced by free_image(), image_set_name(), lkrn_exec(), and register_image().

PROBE_MULTIBOOT

#define PROBE_MULTIBOOT   01

Multiboot image probe priority.

Multiboot images are also valid executables in another format (e.g. ELF), so we must perform the multiboot probe first.

Definition at line 158 of file image.h.

Referenced by __image_type().

PROBE_NORMAL

#define PROBE_NORMAL   02

Normal image probe priority.

Definition at line 163 of file image.h.

Referenced by __image_type().

PROBE_PXE

#define PROBE_PXE   03

PXE image probe priority.

PXE images have no signature checks, so will claim all image files. They must therefore be tried last in the probe order list.

Definition at line 171 of file image.h.

Referenced by __image_type().

IMAGE_TYPES

#define IMAGE_TYPES   __table ( struct image_type, "image_types" )

Executable image type table.

Definition at line 174 of file image.h.

Referenced by image_probe().

__image_type

#define __image_type

(

probe_order

)

Value:

__table_entry ( IMAGE_TYPES, probe_order )

An executable image type.

Definition at line 177 of file image.h.

Referenced by __image_type(), __image_type(), and __image_type().

IMAGE_TAGS

#define IMAGE_TAGS   __table ( struct image_tag, "image_tags" )

Image tag table.

Definition at line 188 of file image.h.

Referenced by free_image(), and imgstat().

__image_tag

struct image_tag current_image __image_tag   __table_entry ( IMAGE_TAGS, 01 )

An image tag.

Currently-executing image.

Definition at line 191 of file image.h.

Referenced by FILE_SECBOOT().

for_each_image

#define for_each_image

(

image

)

Value:

list_for_each_entry ( (image), &images, list )

Iterate over all registered images.

Definition at line 199 of file image.h.

#define for_each_image( image ) \
        list_for_each_entry ( (image), &images, list )

Referenced by efi_file_find(), efi_file_get_info(), efi_file_install(), efi_file_read_dir(), efi_file_read_initrd(), find_image(), find_image_tag(), initrd_dump(), initrd_load_all(), initrd_squash_high(), initrd_swap_any(), and multiboot_add_modules().

for_each_image_safe

#define for_each_image_safe	(		image,
			tmp )

Value:

list_for_each_entry_safe ( (image), (tmp), &images, list )

Iterate over all registered images, safe against deletion.

Definition at line 203 of file image.h.

#define for_each_image_safe( image, tmp ) \
        list_for_each_entry_safe ( (image), (tmp), &images, list )

Referenced by imgmulti_exec().

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

FILE_SECBOOT()

FILE_SECBOOT

(

PERMITTED

)

first_image()

struct image * first_image ( void )

inlinestatic

Retrieve first image.

Return values

image

Image, or NULL

Definition at line 211 of file image.h.

                                                  {
        return list_first_entry ( &images, struct image, list );
}

References images, image::list, and list_first_entry.

Referenced by ipxe().

free_image()

void free_image ( struct refcnt * refcnt )

extern

Free executable image.

Parameters

refcnt

Reference counter

Image consumers must call image_put() rather than calling free_image() directly. This function is exposed for use only by static images.

Definition at line 89 of file image.c.

                                          {
        struct image *image = container_of ( refcnt, struct image, refcnt );
        struct image_tag *tag;
 
        /* Sanity check: free_image() should not be called directly on
         * dynamically allocated images.
         */
        assert ( refcnt->count < 0 );
        DBGC ( image, "IMAGE %s freed\n", image->name );
 
        /* Clear any tag weak references */
        for_each_table_entry ( tag, IMAGE_TAGS ) {
                if ( tag->image == image )
                        tag->image = NULL;
        }
 
        /* Free dynamic allocations used by both static and dynamic images */
        free ( image->cmdline );
        uri_put ( image->uri );
        image_put ( image->replacement );
 
        /* Free image name, if dynamically allocated */
        if ( ! ( image->flags & IMAGE_STATIC_NAME ) )
                free ( image->name );
 
        /* Free image data and image itself, if dynamically allocated */
        if ( ! ( image->flags & IMAGE_STATIC ) ) {
                image_set_len ( image, 0 );
                free ( image );
        }
}

References assert, image::cmdline, container_of, refcnt::count, DBGC, image::flags, for_each_table_entry, free, image_put(), image_set_len(), IMAGE_STATIC, IMAGE_STATIC_NAME, IMAGE_TAGS, image::name, NULL, image::replacement, tag, image::uri, and uri_put().

Referenced by alloc_image(), cmdline_image_free(), efi_cmdline_free(), and lkrn_exec().

alloc_image()

struct image * alloc_image ( struct uri * uri )

extern

Allocate executable image.

Parameters

uri	URI, or NULL

Return values

image

Executable image

Definition at line 127 of file image.c.

                                               {
        struct image *image;
        int rc;
 
        /* Allocate image */
        image = zalloc ( sizeof ( *image ) );
        if ( ! image )
                goto err_alloc;
 
        /* Initialise image */
        ref_init ( &image->refcnt, free_image );
        if ( uri && ( ( rc = image_set_uri ( image, uri ) ) != 0 ) )
                goto err_set_uri;
        image->data = empty_image_data;
 
        return image;
 
 err_set_uri:
        image_put ( image );
 err_alloc:
        return NULL;
}

References image::data, empty_image_data, free_image(), image_put(), image_set_uri(), NULL, rc, ref_init, image::refcnt, and zalloc().

Referenced by cpio_okx(), image_extract(), image_memory(), and imgdownload().

image_set_uri()

int image_set_uri ( struct image * image, struct uri * uri )

extern

Set image URI.

Parameters

image	Image
uri	New image URI

Return values

rc	Return status code

Definition at line 157 of file image.c.

                                                           {
        const char *name;
        int rc;
 
        /* Set name, if image does not already have one */
        if ( ! ( image->name && image->name[0] ) ) {
                name = ( uri->path ? uri->path : uri->opaque );
                if ( name ) {
                        name = basename ( ( char * ) name );
                        if ( ( rc = image_set_name ( image, name ) ) != 0 )
                                return rc;
                }
        }
 
        /* Update image URI */
        uri_put ( image->uri );
        image->uri = uri_get ( uri );
 
        return 0;
}

References basename(), image_set_name(), image::name, name, uri::opaque, uri::path, rc, image::uri, uri_get(), and uri_put().

Referenced by alloc_image(), and downloader_vredirect().

image_set_name()

int image_set_name ( struct image * image, const char * name )

extern

Set image name.

Parameters

image	Image
name	New image name

Return values

rc	Return status code

Definition at line 185 of file image.c.

                                                             {
        char *name_copy;
 
        /* Duplicate name */
        name_copy = strdup ( name );
        if ( ! name_copy )
                return -ENOMEM;
 
        /* Free existing name, if not statically allocated */
        if ( ! ( image->flags & IMAGE_STATIC_NAME ) )
                free ( image->name );
 
        /* Replace existing name */
        image->name = name_copy;
        image->flags &= ~IMAGE_STATIC_NAME;
 
        return 0;
}

References ENOMEM, image::flags, free, IMAGE_STATIC_NAME, image::name, name, and strdup().

Referenced by cms_decrypt(), cpio_okx(), image_extract(), image_memory(), image_set_uri(), imgsingle_exec(), and register_image().

image_strip_suffix()

char * image_strip_suffix ( struct image * image )

extern

Strip dot suffix from image name, if present.

Parameters

image

Image

Return values

sep	Position of old dot separator, or NULL

Definition at line 210 of file image.c.

                                                  {
        char *dot;
 
        /* Locate and strip suffix, if present */
        if ( image->name &&
             ( ( dot = strrchr ( image->name, '.' ) ) != NULL ) ) {
                *dot = '\0';
                return dot;
        }
 
        return NULL;
}

References image::name, NULL, and strrchr().

Referenced by cms_decrypt(), and image_extract().

image_set_cmdline()

int image_set_cmdline ( struct image * image, const char * cmdline )

extern

Set image command line.

Parameters

image	Image
cmdline	New image command line, or NULL

Return values

rc	Return status code

Definition at line 230 of file image.c.

                                                                   {
 
        free ( image->cmdline );
        image->cmdline = NULL;
        if ( cmdline ) {
                image->cmdline = strdup ( cmdline );
                if ( ! image->cmdline )
                        return -ENOMEM;
        }
        return 0;
}

References cmdline, image::cmdline, ENOMEM, free, NULL, and strdup().

Referenced by cpio_okx(), image_clear_cmdline(), image_extract_exec(), and imgsingle_exec().

image_set_len()

int image_set_len ( struct image * image, size_t len )

extern

Set image length.

Parameters

image	Image
len	Length of image data

Return values

rc	Return status code

Definition at line 249 of file image.c.

                                                      {
        size_t alloc_len;
        void *data;
        void *new;
        char *nul;
 
        /* Refuse to reallocate static images */
        if ( image->flags & IMAGE_STATIC )
                return -ENOTTY;
 
        /* Calculate allocation length (including a terminating NUL) */
        alloc_len = ( len ? ( len + 1 ) : 0 );
        if ( alloc_len < len )
                return -ERANGE;
 
        /* (Re)allocate image data */
        data = image->rwdata;
        if ( data == empty_image_data )
                data = NULL;
        new = urealloc ( data, alloc_len );
        if ( ! new )
                return -ENOMEM;
        image->data = ( len ? new : empty_image_data );
        image->len = len;
 
        /* Add terminating NUL (if not the empty image) */
        if ( len ) {
                nul = ( image->rwdata + len );
                *nul = '\0';
        }
 
        return 0;
}

References data, image::data, empty_image_data, ENOMEM, ENOTTY, ERANGE, image::flags, IMAGE_STATIC, image::len, len, NULL, image::rwdata, and urealloc().

Referenced by cpio_okx(), free_image(), gzip_extract(), image_set_data(), mime_decode_base64(), mime_decode_identity(), mime_extract_part(), xferbuf_image_realloc(), and zlib_deflate().

image_set_data()

int image_set_data ( struct image * image, const void * data, size_t len )

extern

Set image data.

Parameters

image	Image
data	Image data
len	Length of image data

Return values

rc	Return status code

Definition at line 291 of file image.c.

                                                                         {
        int rc;
 
        /* Set image length */
        if ( ( rc = image_set_len ( image, len ) ) != 0 )
                return rc;
 
        /* Copy in new image data */
        memcpy ( image->rwdata, data, len );
 
        return 0;
}

References data, image_set_len(), len, memcpy(), rc, and image::rwdata.

Referenced by image_memory(), and zimg_extract().

register_image()

int register_image ( struct image * image )

extern

Register executable image.

Parameters

image

Executable image

Return values

rc	Return status code

Definition at line 336 of file image.c.

                                           {
        static unsigned int imgindex = 0;
        char name[8]; /* "imgXXXX" */
        int rc;
 
        /* Sanity checks */
        if ( image->flags & IMAGE_STATIC ) {
                assert ( ( image->name == NULL ) ||
                         ( image->flags & IMAGE_STATIC_NAME ) );
                assert ( image->cmdline == NULL );
        }
 
        /* Create image name if it doesn't already have one */
        if ( ! image->name ) {
                snprintf ( name, sizeof ( name ), "img%d", imgindex++ );
                if ( ( rc = image_set_name ( image, name ) ) != 0 )
                        return rc;
        }
 
        /* Check for terminating NUL (required for text-based images) */
        if ( ! image->data ) {
                DBGC ( image, "IMAGE %s has no data\n", image->name );
                return -EINVAL;
        }
        if ( image->text[image->len] != '\0' ) {
                DBGC ( image, "IMAGE %s missing terminating NUL\n",
                       image->name );
                return -EINVAL;
        }
 
        /* Add to image list */
        image_get ( image );
        image->flags |= IMAGE_REGISTERED;
        list_add_tail ( &image->list, &images );
        DBGC ( image, "IMAGE %s at [%lx,%lx) registered\n",
               image->name, virt_to_phys ( image->data ),
               ( virt_to_phys ( image->data ) + image->len ) );
 
        /* Try to detect image type, if applicable.  Ignore failures,
         * since we expect to handle some unrecognised images
         * (e.g. kernel initrds, multiboot modules, random files
         * provided via our EFI virtual filesystem, etc).
         */
        if ( ! image->type )
                image_probe ( image );
 
        return 0;
}

References assert, image::cmdline, image::data, DBGC, EINVAL, image::flags, image_get(), image_probe(), IMAGE_REGISTERED, image_set_name(), IMAGE_STATIC, IMAGE_STATIC_NAME, images, image::len, image::list, list_add_tail, image::name, name, NULL, rc, snprintf(), image::text, and image::type.

Referenced by asn1_okx(), cmdline_init(), cms_decrypt(), efi_cmdline_init(), efi_image_exec(), embedded_init(), image_exec(), image_extract(), image_memory(), imgdownload(), pixbuf_okx(), and test_init().

unregister_image()

void unregister_image ( struct image * image )

extern

Unregister executable image.

Parameters

image

Executable image

Definition at line 390 of file image.c.

                                              {
 
        /* Do nothing unless image is registered */
        if ( ! ( image->flags & IMAGE_REGISTERED ) )
                return;
 
        DBGC ( image, "IMAGE %s unregistered\n", image->name );
        list_del ( &image->list );
        image->flags &= ~IMAGE_REGISTERED;
        image_put ( image );
}

References DBGC, image::flags, image_put(), IMAGE_REGISTERED, image::list, list_del, and image::name.

Referenced by archive_okx(), asn1_okx(), bzimage_exec(), cert_exec(), cms_decrypt(), com32_exec_loop(), comboot_exec_loop(), console_exec(), efi_autoexec_load(), efi_image_exec(), fdt_test_exec(), image_exec(), image_extract(), image_extract_exec(), imgdecrypt_exec(), imgextract_exec(), imgfree_exec(), imgset_exec(), imgverify_exec(), and pixbuf_okx().

find_image()

struct image * find_image ( const char * name )

extern

Find image by name.

Parameters

name	Image name

Return values

image

Executable image, or NULL

Definition at line 408 of file image.c.

                                               {
        struct image *image;
 
        for_each_image ( image ) {
                if ( strcmp ( image->name, name ) == 0 )
                        return image;
        }
 
        return NULL;
}

References for_each_image, image::name, name, NULL, and strcmp().

Referenced by imgacquire(), and imgmulti_exec().

find_image_tag()

struct image * find_image_tag ( struct image_tag * tag )

extern

Find image by tag.

Parameters

tag

Image tag

Return values

image

Executable image, or NULL

Definition at line 425 of file image.c.

                                                        {
        struct image *image;
 
        for_each_image ( image ) {
                if ( tag->image == image )
                        return image;
        }
 
        return NULL;
}

References for_each_image, NULL, and tag.

Referenced by efi_file_open(), efi_image_exec(), fdt_create(), imgsingle_exec(), and shim_exec().

image_exec()

int image_exec ( struct image * image )

extern

Execute image.

Parameters

image

Executable image

Return values

rc	Return status code

The image must already be registered. Note that executing an image may cause it to unregister itself. The caller must therefore assume that the image pointer becomes invalid.

Definition at line 446 of file image.c.

                                       {
        struct image *saved_current_image;
        struct image *replacement = NULL;
        struct uri *old_cwuri;
        int rc;
 
        /* Sanity check */
        assert ( image->flags & IMAGE_REGISTERED );
 
        /* Switch current working directory to be that of the image
         * itself, if applicable
         */
        old_cwuri = uri_get ( cwuri );
        if ( image->uri )
                churi ( image->uri );
 
        /* Set as currently running image */
        saved_current_image = image_tag ( image, &current_image );
 
        /* Take out a temporary reference to the image, so that it
         * does not get freed when temporarily unregistered.
         */
        image_get ( image );
 
        /* Check that this image can be executed */
        if ( ! ( image->type && image->type->exec ) ) {
                rc = -ENOEXEC;
                goto err;
        }
 
        /* Check that image is trusted (if applicable) */
        if ( require_trusted_images && ! ( image->flags & IMAGE_TRUSTED ) ) {
                DBGC ( image, "IMAGE %s is not trusted\n", image->name );
                rc = -EACCES_UNTRUSTED;
                goto err;
        }
 
        /* Record boot attempt */
        syslog ( LOG_NOTICE, "Executing \"%s\"\n", image->name );
 
        /* Temporarily unregister the image during its execution */
        unregister_image ( image );
 
        /* Try executing the image */
        if ( ( rc = image->type->exec ( image ) ) != 0 ) {
                DBGC ( image, "IMAGE %s could not execute: %s\n",
                       image->name, strerror ( rc ) );
                /* Do not return yet; we still have clean-up to do */
        }
 
        /* Record result of boot attempt */
        if ( rc == 0 ) {
                syslog ( LOG_NOTICE, "Execution of \"%s\" completed\n",
                         image->name );
        } else {
                syslog ( LOG_ERR, "Execution of \"%s\" failed: %s\n",
                         image->name, strerror ( rc ) );
        }
 
        /* Re-register image (unless due to be replaced) */
        if ( ! image->replacement )
                register_image ( image );
 
        /* Pick up replacement image before we drop the original
         * image's temporary reference.  The replacement image must
         * already be registered, so we don't need to hold a temporary
         * reference (which would complicate the tail-recursion).
         */
        replacement = image->replacement;
        if ( replacement )
                assert ( replacement->flags & IMAGE_REGISTERED );
 
        /* Clear any recorded replacement image */
        image_put ( image->replacement );
        image->replacement = NULL;
 
 err:
        /* Unregister image if applicable */
        if ( image->flags & IMAGE_AUTO_UNREGISTER )
                unregister_image ( image );
 
        /* Debug message for tail-recursion.  Placed here because the
         * image_put() may end up freeing the image.
         */
        if ( replacement ) {
                DBGC ( image, "IMAGE %s replacing self with IMAGE %s\n",
                       image->name, replacement->name );
        }
 
        /* Drop temporary reference to the original image */
        image_put ( image );
 
        /* Restore previous currently-running image */
        image_tag ( saved_current_image, &current_image );
 
        /* Reset current working directory */
        churi ( old_cwuri );
        uri_put ( old_cwuri );
 
        /* Tail-recurse into replacement image, if one exists */
        if ( replacement )
                return image_exec ( replacement );
 
        return rc;
}

References assert, churi(), current_image, cwuri, DBGC, EACCES_UNTRUSTED, ENOEXEC, image_type::exec, image::flags, IMAGE_AUTO_UNREGISTER, image_exec(), image_get(), image_put(), IMAGE_REGISTERED, image_tag(), IMAGE_TRUSTED, LOG_ERR, LOG_NOTICE, image::name, NULL, rc, register_image(), image::replacement, replacement, require_trusted_images, strerror(), syslog, image::type, unregister_image(), image::uri, uri_get(), and uri_put().

Referenced by image_exec(), imgexec(), ipxe(), and uriboot().

image_replace()

int image_replace ( struct image * replacement )

extern

Set replacement image.

Parameters

replacement

Replacement image

Return values

rc	Return status code

The replacement image must already be registered, and must remain registered until the currently-executing image returns.

Definition at line 561 of file image.c.

                                                {
        struct image *image = current_image.image;
        int rc;
 
        /* Sanity check */
        assert ( replacement->flags & IMAGE_REGISTERED );
 
        /* Fail unless there is a currently-executing image */
        if ( ! image ) {
                rc = -ENOTTY;
                DBGC ( replacement, "IMAGE %s cannot replace non-existent "
                       "image: %s\n", replacement->name, strerror ( rc ) );
                return rc;
        }
 
        /* Check that the replacement image can be executed */
        if ( ! ( replacement->type && replacement->type->exec ) )
                return -ENOEXEC;
 
        /* Clear any existing replacement */
        image_put ( image->replacement );
 
        /* Set replacement */
        image->replacement = image_get ( replacement );
        DBGC ( image, "IMAGE %s will replace self with IMAGE %s\n",
               image->name, replacement->name );
 
        return 0;
}

References assert, current_image, DBGC, ENOEXEC, ENOTTY, image_get(), image_put(), IMAGE_REGISTERED, image::name, rc, image::replacement, replacement, and strerror().

Referenced by comboot_fetch_kernel(), image_extract_exec(), and imgexec().

image_select()

int image_select ( struct image * image )

extern

Select image for execution.

Parameters

image

Executable image

Return values

rc	Return status code

Definition at line 597 of file image.c.

                                         {
 
        /* Check that this image can be executed */
        if ( ! ( image->type && image->type->exec ) )
                return -ENOEXEC;
 
        /* Mark image as selected */
        image_tag ( image, &selected_image );
 
        return 0;
}

References ENOEXEC, image_type::exec, image_tag(), selected_image, and image::type.

Referenced by embedded_init(), and imgselect().

image_set_trust()

int image_set_trust ( int require_trusted, int permanent )

extern

Change image trust requirement.

Parameters

require_trusted	Require trusted images
permanent	Make trust requirement permanent

Return values

rc	Return status code

Definition at line 616 of file image.c.

                                                           {
 
        /* Update trust requirement, if permitted to do so */
        if ( ! require_trusted_images_permanent ) {
                require_trusted_images = require_trusted;
                require_trusted_images_permanent = permanent;
        }
 
        /* Fail if we attempted to change the trust requirement but
         * were not permitted to do so.
         */
        if ( require_trusted_images != require_trusted )
                return -EACCES_PERMANENT;
 
        return 0;
}

References EACCES_PERMANENT, require_trusted_images, and require_trusted_images_permanent.

Referenced by imgtrust_exec().

image_memory()

struct image * image_memory ( const char * name, const void * data, size_t len )

extern

Create registered image from block of memory.

Parameters

name	Name
data	Image data
len	Length

Return values

image

Image, or NULL on error

Definition at line 641 of file image.c.

                                           {
        struct image *image;
        int rc;
 
        /* Allocate image */
        image = alloc_image ( NULL );
        if ( ! image ) {
                rc = -ENOMEM;
                goto err_alloc_image;
        }
 
        /* Set name */
        if ( ( rc = image_set_name ( image, name ) ) != 0 )
                goto err_set_name;
 
        /* Set data */
        if ( ( rc = image_set_data ( image, data, len ) ) != 0 )
                goto err_set_data;
 
        /* Register image */
        if ( ( rc = register_image ( image ) ) != 0 )
                goto err_register;
 
        /* Drop local reference to image */
        image_put ( image );
 
        return image;
 
 err_register:
 err_set_data:
 err_set_name:
        image_put ( image );
 err_alloc_image:
        return NULL;
}

References alloc_image(), data, ENOMEM, image_put(), image_set_data(), image_set_name(), len, name, NULL, rc, and register_image().

Referenced by archive_okx(), fdt_test_exec(), imgmem(), and initrd_init().

image_argument()

const char * image_argument ( struct image * image, const char * key )

extern

Find argument within image command line.

Parameters

image	Image
key	Argument search key (including trailing delimiter)

Return values

value

Argument value, or NULL if not found

Definition at line 685 of file image.c.

                                                                     {
        const char *cmdline = image->cmdline;
        const char *search;
        const char *match;
        const char *next;
 
        /* Find argument */
        for ( search = cmdline ; search ; search = next ) {
 
                /* Find next occurrence, if any */
                match = strstr ( search, key );
                if ( ! match )
                        break;
                next = ( match + strlen ( key ) );
 
                /* Check preceding delimiter, if any */
                if ( ( match == cmdline ) || isspace ( match[-1] ) )
                        return next;
        }
 
        return NULL;
}

References cmdline, image::cmdline, isspace(), key, next, NULL, strlen(), and strstr().

Referenced by bzimage_parse_cmdline(), and cpio_parse_cmdline().

image_pixbuf()

int image_pixbuf ( struct image * image, struct pixel_buffer ** pixbuf )

extern

Create pixel buffer from image.

Parameters

image	Image
pixbuf	Pixel buffer to fill in

Return values

rc	Return status code

Definition at line 100 of file pixbuf.c.

                                                                       {
        int rc;
 
        /* Check that this image can be used to create a pixel buffer */
        if ( ! ( image->type && image->type->pixbuf ) )
                return -ENOTSUP;
 
        /* Try creating pixel buffer */
        if ( ( rc = image->type->pixbuf ( image, pixbuf ) ) != 0 ) {
                DBGC ( image, "IMAGE %s could not create pixel buffer: %s\n",
                       image->name, strerror ( rc ) );
                return rc;
        }
 
        return 0;
}

References DBGC, ENOTSUP, image::name, image_type::pixbuf, rc, strerror(), and image::type.

Referenced by console_exec(), pixbuf_okx(), and REQUIRING_SYMBOL().

image_asn1()

int image_asn1 ( struct image * image, size_t offset, struct asn1_cursor ** cursor )

extern

Extract ASN.1 object from image.

Parameters

image	Image
offset	Offset within image
cursor	ASN.1 cursor to fill in

Return values

next	Offset to next image, or negative error

The caller is responsible for eventually calling free() on the allocated ASN.1 cursor.

Definition at line 1098 of file asn1.c.

                                               {
        int next;
        int rc;
 
        /* Sanity check */
        assert ( offset <= image->len );
 
        /* Check that this image can be used to extract an ASN.1 object */
        if ( ! ( image->type && image->type->asn1 ) )
                return -ENOTSUP;
 
        /* Try creating ASN.1 cursor */
        next = image->type->asn1 ( image, offset, cursor );
        if ( next < 0 ) {
                rc = next;
                DBGC ( image, "IMAGE %s could not extract ASN.1 object: %s\n",
                       image->name, strerror ( rc ) );
                return rc;
        }
 
        return next;
}

References image_type::asn1, assert, DBGC, ENOTSUP, len, image::name, next, offset, rc, strerror(), and image::type.

Referenced by asn1_okx(), cms_message(), image_x509(), and REQUIRING_SYMBOL().

image_extract()

int image_extract ( struct image * image, const char * name, struct image ** extracted )

extern

Extract archive image.

Parameters

image	Image
name	Extracted image name
extracted	Extracted image to fill in

Return values

rc	Return status code

Definition at line 45 of file archive.c.

                                               {
        int rc;
 
        /* Check that this image can be used to extract an archive image */
        if ( ! ( image->type && image->type->extract ) ) {
                rc = -ENOTSUP;
                goto err_unsupported;
        }
 
        /* Allocate new image */
        *extracted = alloc_image ( image->uri );
        if ( ! *extracted ) {
                rc = -ENOMEM;
                goto err_alloc;
        }
 
        /* Set image name */
        if ( ( rc = image_set_name ( *extracted,
                                     ( name ? name : image->name ) ) ) != 0 ) {
                goto err_set_name;
        }
 
        /* Strip any archive or compression suffix from implicit name */
        if ( ! name )
                image_strip_suffix ( *extracted );
 
        /* Try extracting archive image */
        if ( ( rc = image->type->extract ( image, *extracted ) ) != 0 ) {
                DBGC ( image, "IMAGE %s could not extract image: %s\n",
                       image->name, strerror ( rc ) );
                goto err_extract;
        }
 
        /* Register image */
        if ( ( rc = register_image ( *extracted ) ) != 0 )
                goto err_register;
 
        /* Propagate trust flag */
        if ( image->flags & IMAGE_TRUSTED )
                image_trust ( *extracted );
 
        /* Drop local reference to image */
        image_put ( *extracted );
 
        return 0;
 
        unregister_image ( *extracted );
 err_register:
 err_extract:
 err_set_name:
        image_put ( *extracted );
 err_alloc:
 err_unsupported:
        return rc;
}

References alloc_image(), DBGC, ENOMEM, ENOTSUP, image_type::extract, image::flags, image_put(), image_set_name(), image_strip_suffix(), image_trust(), IMAGE_TRUSTED, image::name, name, rc, register_image(), strerror(), image::type, unregister_image(), and image::uri.

Referenced by archive_okx(), image_extract_exec(), imgextract(), and REQUIRING_SYMBOL().

image_extract_exec()

int image_extract_exec ( struct image * image )

extern

Extract and execute image.

Parameters

image

Image

Return values

rc	Return status code

Definition at line 108 of file archive.c.

                                               {
        struct image *extracted;
        int rc;
 
        /* Extract image */
        if ( ( rc = image_extract ( image, NULL, &extracted ) ) != 0 )
                goto err_extract;
 
        /* Set image command line */
        if ( ( rc = image_set_cmdline ( extracted, image->cmdline ) ) != 0 )
                goto err_set_cmdline;
 
        /* Set auto-unregister flag */
        extracted->flags |= IMAGE_AUTO_UNREGISTER;
 
        /* Replace current image */
        if ( ( rc = image_replace ( extracted ) ) != 0 )
                goto err_replace;
 
        /* Return to allow replacement image to be executed */
        return 0;
 
 err_replace:
 err_set_cmdline:
        unregister_image ( extracted );
 err_extract:
        return rc;
}

References image::cmdline, image::flags, IMAGE_AUTO_UNREGISTER, image_extract(), image_replace(), image_set_cmdline(), NULL, rc, and unregister_image().

Referenced by __image_type().

image_get()

struct image * image_get ( struct image * image )

inlinestatic

Increment reference count on an image.

Parameters

image

Image

Return values

image

Image

Definition at line 248 of file image.h.

                                                               {
        ref_get ( &image->refcnt );
        return image;
}

References ref_get, and image::refcnt.

Referenced by bzimage_exec(), cms_decrypt(), create_downloader(), efi_file_open_image(), image_exec(), image_replace(), and register_image().

image_put()

void image_put ( struct image * image )

inlinestatic

Decrement reference count on an image.

Parameters

image

Image

Definition at line 258 of file image.h.

                                                     {
        ref_put ( &image->refcnt );
}

References ref_put, and image::refcnt.

Referenced by alloc_image(), cmdline_init(), cms_decrypt(), cpio_okx(), downloader_free(), efi_cmdline_init(), efi_file_free(), free_image(), image_exec(), image_extract(), image_memory(), image_replace(), imgdownload(), and unregister_image().

image_clear_cmdline()

void image_clear_cmdline ( struct image * image )

inlinestatic

Clear image command line.

Parameters

image

Image

Definition at line 267 of file image.h.

                                                               {
        image_set_cmdline ( image, NULL );
}

References image_set_cmdline(), and NULL.

image_trust()

void image_trust ( struct image * image )

inlinestatic

Set image as trusted.

Parameters

image

Image

Definition at line 276 of file image.h.

                                                       {
        image->flags |= IMAGE_TRUSTED;
}

References image::flags, and IMAGE_TRUSTED.

Referenced by cms_verify(), embedded_init(), and image_extract().

image_untrust()

void image_untrust ( struct image * image )

inlinestatic

Set image as untrusted.

Parameters

image

Image

Definition at line 285 of file image.h.

                                                         {
        image->flags &= ~IMAGE_TRUSTED;
}

References image::flags, and IMAGE_TRUSTED.

Referenced by cms_decrypt(), and cms_verify().

image_hide()

void image_hide ( struct image * image )

inlinestatic

Mark image as hidden.

Parameters

image

Image

Definition at line 294 of file image.h.

                                                      {
        image->flags |= IMAGE_HIDDEN;
}

References image::flags, and IMAGE_HIDDEN.

Referenced by imgfdt(), and shim().

image_tag()

struct image * image_tag ( struct image * image, struct image_tag * tag )

inlinestatic

Tag image.

Parameters

image	Image
tag	Image tag

Return values

prev	Previous tagged image (if any)

Definition at line 305 of file image.h.

                                                                 {
        struct image *prev = tag->image;
 
        tag->image = image;
        return prev;
}

References tag.

Referenced by fdt_test_exec(), image_exec(), image_select(), imgfdt(), and shim().

Variable Documentation

images

struct list_head images

extern

List of registered images.

Definition at line 59 of file image.c.

Referenced by first_image(), initrd_dump(), initrd_load(), initrd_region(), initrd_squash_high(), initrd_startup(), initrd_swap(), lkrn_exec(), and register_image().

current_image

struct image_tag current_image

extern

Referenced by goto_exec(), image_exec(), and image_replace().

selected_image

struct image_tag selected_image

extern

Referenced by efi_file_open(), image_select(), imgsingle_exec(), and shim_exec().

empty_image_data

const char empty_image_data[]

extern

Empty image terminating NUL.

Definition at line 78 of file image.c.

{ '\0' };

Referenced by alloc_image(), and image_set_len().