zlib.c File Reference

zlib compressed images More...

#include <stdlib.h>
#include <errno.h>
#include <assert.h>
#include <ipxe/deflate.h>
#include <ipxe/uaccess.h>
#include <ipxe/image.h>
#include <ipxe/zlib.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
int	zlib_deflate (enum deflate_format format, struct deflate_chunk *in, struct image *extracted)
	Extract compressed data to image. More...
static int	zlib_extract (struct image *image, struct image *extracted)
	Extract zlib image. More...
static int	zlib_probe (struct image *image)
	Probe zlib image. More...
struct image_type zlib_image_type	__image_type (PROBE_NORMAL)
	zlib image type More...

Detailed Description

zlib compressed images

Definition in file zlib.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

zlib_deflate()

int zlib_deflate	(	enum deflate_format	format,
		struct deflate_chunk *	in,
		struct image *	extracted
	)

Extract compressed data to image.

Parameters

format	Compression format code
in	Compressed input chunk
extracted	Extracted image

Return values

rc	Return status code

Definition at line 48 of file zlib.c.

                                             {
        struct deflate *deflate;
        struct deflate_chunk out;
        int rc;

        /* Allocate and initialise decompressor */
        deflate = zalloc ( sizeof ( *deflate ) );
        if ( ! deflate ) {
                rc = -ENOMEM;
                goto err_alloc;
        }

        /* Decompress data, (re)allocating if necessary */
        while ( 1 ) {

                /* (Re)initialise decompressor */
                deflate_init ( deflate, format );

                /* (Re)initialise input chunk */
                in->offset = 0;

                /* Initialise output chunk */
                deflate_chunk_init ( &out, extracted->data, 0, extracted->len );

                /* Decompress data */
                if ( ( rc = deflate_inflate ( deflate, in, &out ) ) != 0 ) {
                        DBGC ( extracted, "ZLIB %p could not decompress: %s\n",
                               extracted, strerror ( rc ) );
                        goto err_inflate;
                }

                /* Check that decompression is valid */
                if ( ! deflate_finished ( deflate ) ) {
                        DBGC ( extracted, "ZLIB %p decompression incomplete\n",
                               extracted );
                        rc = -EINVAL;
                        goto err_unfinished;
                }

                /* Finish if output image size was correct */
                if ( out.offset == extracted->len )
                        break;

                /* Otherwise, resize output image and retry */
                if ( ( rc = image_set_len ( extracted, out.offset ) ) != 0 ) {
                        DBGC ( extracted, "ZLIB %p could not resize: %s\n",
                               extracted, strerror ( rc ) );
                        goto err_set_size;
                }
        }

        /* Success */
        rc = 0;

 err_set_size:
 err_unfinished:
 err_inflate:
        free ( deflate );
 err_alloc:
        return rc;
}

References image::data, DBGC, deflate_finished(), deflate_inflate(), deflate_init(), EINVAL, ENOMEM, format, free, image_set_len(), in, image::len, out, rc, strerror(), and zalloc().

Referenced by gzip_extract(), and zlib_extract().

zlib_extract()

static int zlib_extract ( struct image *  image, struct image *  extracted  )

static

Extract zlib image.

Parameters

image	Image
extracted	Extracted image

Return values

rc	Return status code

Definition at line 118 of file zlib.c.

                                                                         {
        struct deflate_chunk in;
        int rc;

        /* Initialise input chunk */
        deflate_chunk_init ( &in, image->data, 0, image->len );

        /* Decompress image */
        if ( ( rc = zlib_deflate ( DEFLATE_ZLIB, &in, extracted ) ) != 0 )
                return rc;

        return 0;
}

References image::data, DEFLATE_ZLIB, in, image::len, rc, and zlib_deflate().

zlib_probe()

static int zlib_probe ( struct image *  image )

static

Probe zlib image.

Parameters

image

zlib image

Return values

rc	Return status code

Definition at line 138 of file zlib.c.

                                              {
        union zlib_magic magic;

        /* Sanity check */
        if ( image->len < sizeof ( magic ) ) {
                DBGC ( image, "ZLIB %p image too short\n", image );
                return -ENOEXEC;
        }

        /* Check magic header */
        copy_from_user ( &magic, image->data, 0, sizeof ( magic ) );
        if ( ! zlib_magic_is_valid ( &magic ) ) {
                DBGC ( image, "ZLIB %p invalid magic data\n", image );
                return -ENOEXEC;
        }

        return 0;
}

References copy_from_user(), image::data, DBGC, ENOEXEC, image::len, magic, and zlib_magic_is_valid().

__image_type()

struct image_type zlib_image_type __image_type

(

PROBE_NORMAL

)

zlib image type