onlineupdate/inc/bspatch.h

   1 /*-
   2  * Copyright 2003,2004 Colin Percival
   3  * All rights reserved
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted providing that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  18  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  23  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  24  * POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * Changelog:
  27  * 2005-04-26 - Define the header as a C structure, add a CRC32 checksum to
  28  *              the header, and make all the types 32-bit.
  29  *                --Benjamin Smedberg <benjamin@smedbergs.us>
  30  */
  31
  32 #ifndef bspatch_h__
  33 #define bspatch_h__
  34
  35 #include <stdint.h>
  36 #include <stdio.h>
  37
  38 typedef struct MBSPatchHeader_
  39 {
  40     /* "MBDIFF10" */
  41     char tag[8];
  42
  43     /* Length of the file to be patched */
  44     uint32_t slen;
  45
  46     /* CRC32 of the file to be patched */
  47     uint32_t scrc32;
  48
  49     /* Length of the result file */
  50     uint32_t dlen;
  51
  52     /* Length of the control block in bytes */
  53     uint32_t cblen;
  54
  55     /* Length of the diff block in bytes */
  56     uint32_t difflen;
  57
  58     /* Length of the extra block in bytes */
  59     uint32_t extralen;
  60
  61     /* Control block (MBSPatchTriple[]) */
  62     /* Diff block (binary data) */
  63     /* Extra block (binary data) */
  64 } MBSPatchHeader;
  65
  66 /**
  67  * Read the header of a patch file into the MBSPatchHeader structure.
  68  *
  69  * @param fd Must have been opened for reading, and be at the beginning
  70  *           of the file.
  71  */
  72 int MBS_ReadHeader(FILE* file, MBSPatchHeader* header);
  73
  74 /**
  75  * Apply a patch. This method does not validate the checksum of the original
  76  * file: client code should validate the checksum before calling this method.
  77  *
  78  * @param patchfd Must have been processed by MBS_ReadHeader
  79  * @param fbuffer The original file read into a memory buffer of length
  80  *                header->slen.
  81  * @param filefd  Must have been opened for writing. Should be truncated
  82  *                to header->dlen if it is an existing file. The offset
  83  *                should be at the beginning of the file.
  84  */
  85 int MBS_ApplyPatch(const MBSPatchHeader* header, FILE* patchFile, unsigned char* fbuffer,
  86                    FILE* file);
  87
  88 typedef struct MBSPatchTriple_
  89 {
  90     uint32_t x; /* add x bytes from oldfile to x bytes from the diff block */
  91     uint32_t y; /* copy y bytes from the extra block */
  92     int32_t z; /* seek forwards in oldfile by z bytes */
  93 } MBSPatchTriple;
  94
  95 #endif // bspatch_h__