zlib.h File Reference

zlib compressed images More...

#include <stdint.h>
#include <byteswap.h>
#include <ipxe/image.h>
#include <ipxe/deflate.h>

Go to the source code of this file.

Data Structures
union	zlib_magic
	zlib magic header More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static int	zlib_magic_is_valid (union zlib_magic *magic)
	Check that zlib magic header is valid. More...
int	zlib_deflate (enum deflate_format format, struct deflate_chunk *in, struct image *extracted)
	Extract compressed data to image. More...
struct image_type zlib_image_type	__image_type (PROBE_NORMAL)

Detailed Description

zlib compressed images

Definition in file zlib.h.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

zlib_magic_is_valid()

static int zlib_magic_is_valid ( union zlib_magic *  magic )

inlinestatic

Check that zlib magic header is valid.

Parameters

magic

Magic header

Return values

is_valid

Magic header is valid

Definition at line 31 of file zlib.h.

                                                                  {

        /* Check magic value as per RFC 6713 */
        return ( ( ( magic->cmf & 0x8f ) == 0x08 ) &&
                 ( ( be16_to_cpu ( magic->check ) % 31 ) == 0 ) );
}

References be16_to_cpu, and magic.

Referenced by zlib_probe().

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().

__image_type()

struct image_type zlib_image_type __image_type

(

PROBE_NORMAL

)