X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=deanimate.c;h=bba74d49bf233f8b86c6c850ec7f6b873952fc59;hp=b0ba14e9dbb044bb46865b3fb2891fc9f6e696e3;hb=a2f8296e90e9bc3c4e4fa50c9b42e3f12bce24ca;hpb=29aff70c9341505c82124964f20e2213dd04de81 diff --git a/deanimate.c b/deanimate.c index b0ba14e9..bba74d49 100644 --- a/deanimate.c +++ b/deanimate.c @@ -1,23 +1,20 @@ -const char deanimate_rcs[] = "$Id: deanimate.c,v 1.2 2001/07/13 13:46:20 oes Exp $"; /********************************************************************* * * File : $Source: /cvsroot/ijbswa/current/deanimate.c,v $ * - * Purpose : Declares functions to deanimate GIF images on the fly. - * - * Functions declared include: gif_deanimate, buf_free, - * buf_copy, buf_getbyte, gif_skip_data_block, and - * gif_extract_image + * Purpose : Declares functions to manipulate binary images on the + * fly. High-level functions include: + * - Deanimation of GIF images * - * Copyright : Written by and Copyright (C) 2001 Andreas S. Oesterhelt - * for the SourceForge IJBSWA team. http://ijbswa.sourceforge.net + * Copyright : Written by and Copyright (C) 2001 - 2004, 2006 by the + * Privoxy team. https://www.privoxy.org/ * * Based on the GIF file format specification (see * http://tronche.com/computer-graphics/gif/gif89a.html) * and ideas from the Image::DeAnim Perl module by * Ken MacFarlane, * - * This program is free software; you can redistribute it + * This program is free software; you can redistribute it * and/or modify it under the terms of the GNU General * Public License as published by the Free Software * Foundation; either version 2 of the License, or (at @@ -35,14 +32,8 @@ const char deanimate_rcs[] = "$Id: deanimate.c,v 1.2 2001/07/13 13:46:20 oes Exp * or write to the Free Software Foundation, Inc., 59 * Temple Place - Suite 330, Boston, MA 02111-1307, USA. * - * Revisions : - * $Log: deanimate.c,v $ - * Revision 1.2 2001/07/13 13:46:20 oes - * Introduced GIF deanimation feature - * - * **********************************************************************/ - + #include "config.h" @@ -50,13 +41,12 @@ const char deanimate_rcs[] = "$Id: deanimate.c,v 1.2 2001/07/13 13:46:20 oes Exp #include #include "project.h" +#include "errlog.h" #include "deanimate.h" #include "miscutil.h" -const char deanimate_h_rcs[] = DEANIMATE_H_VERSION; - /********************************************************************* - * + * * Function : buf_free * * Description : Safely frees a struct binbuffer @@ -82,7 +72,49 @@ void buf_free(struct binbuffer *buf) /********************************************************************* - * + * + * Function : buf_extend + * + * Description : Ensure that a given binbuffer can hold a given amount + * of bytes, by reallocating its buffer if necessary. + * Allocate new mem in chunks of 1024 bytes, so we don't + * have to realloc() too often. + * + * Parameters : + * 1 : buf = Pointer to the binbuffer + * 2 : length = Desired minimum size + * + * + * Returns : 0 on success, 1 on failure. + * + *********************************************************************/ +static int buf_extend(struct binbuffer *buf, size_t length) +{ + char *newbuf; + + if (buf->offset + length > buf->size) + { + buf->size = ((buf->size + length + (size_t)1023) & ~(size_t)1023); + newbuf = (char *)realloc(buf->buffer, buf->size); + + if (newbuf == NULL) + { + freez(buf->buffer); + return 1; + } + else + { + buf->buffer = newbuf; + return 0; + } + } + return 0; + +} + + +/********************************************************************* + * * Function : buf_copy * * Description : Safely copies a given amount of bytes from one @@ -94,36 +126,26 @@ void buf_free(struct binbuffer *buf) * 2 : dst = Pointer to the destination binbuffer * 3 : length = Number of bytes to be copied * - * Returns : 0 on success, 1 on failiure. + * Returns : 0 on success, 1 on failure. * *********************************************************************/ -int buf_copy(struct binbuffer *src, struct binbuffer *dst, int length) +static int buf_copy(struct binbuffer *src, struct binbuffer *dst, size_t length) { - char *p; /* * Sanity check: Can't copy more data than we have */ - if (src->offset + length > src->size) + if (src->offset + length > src->size) { return 1; } /* - * If dst can't hold the new data, get mem first. (In chunks - * of 1000 bytes, so we don't have to realloc() too often) + * Ensure that dst can hold the new data */ - if (dst->offset + length > dst->size) + if (buf_extend(dst, length)) { - dst->size = dst->size + length + 1000 - (dst->size + length) % 1000; - p = dst->buffer; - dst->buffer = (char *)realloc(dst->buffer, dst->size); - - if (dst->buffer == NULL) - { - free(p); - return 1; - } + return 1; } /* @@ -140,20 +162,20 @@ int buf_copy(struct binbuffer *src, struct binbuffer *dst, int length) /********************************************************************* - * + * * Function : buf_getbyte * * Description : Safely gets a byte from a given binbuffer at a * given offset * * Parameters : - * 1 : buf = Pointer to the source binbuffer + * 1 : src = Pointer to the source binbuffer * 2 : offset = Offset to the desired byte * - * Returns : The byte on success, or 0 on failiure + * Returns : The byte on success, or 0 on failure * *********************************************************************/ -unsigned char buf_getbyte(struct binbuffer *src, int offset) +static unsigned char buf_getbyte(const struct binbuffer *src, size_t offset) { if (src->offset + offset < src->size) { @@ -168,32 +190,33 @@ unsigned char buf_getbyte(struct binbuffer *src, int offset) /********************************************************************* - * + * * Function : gif_skip_data_block * * Description : Safely advances the offset of a given struct binbuffer * that contains a GIF image and whose offset is - * positioned at the start of a data block behind + * positioned at the start of a data block, behind * that block. * * Parameters : * 1 : buf = Pointer to the binbuffer * - * Returns : 0 on success, or 1 on failiure + * Returns : 0 on success, or 1 on failure * *********************************************************************/ -int gif_skip_data_block(struct binbuffer *buf) +static int gif_skip_data_block(struct binbuffer *buf) { unsigned char c; - /* + /* * Data blocks are sequences of chunks, which are headed * by a one-byte length field, with the last chunk having * zero length. */ - while(c = buf_getbyte(buf, 0)) + while((c = buf_getbyte(buf, 0)) != '\0') { - if ((buf->offset += c + 1) >= buf->size - 1) + buf->offset += (size_t)c + 1; + if (buf->offset >= buf->size - 1) { return 1; } @@ -206,25 +229,25 @@ int gif_skip_data_block(struct binbuffer *buf) /********************************************************************* - * + * * Function : gif_extract_image * * Description : Safely extracts an image data block from a given * struct binbuffer that contains a GIF image and whose - * offset is positioned at the start of a data block + * offset is positioned at the start of a data block * into a given destination binbuffer. * * Parameters : * 1 : src = Pointer to the source binbuffer * 2 : dst = Pointer to the destination binbuffer * - * Returns : 0 on success, or 1 on failiure + * Returns : 0 on success, or 1 on failure * *********************************************************************/ -int gif_extract_image(struct binbuffer *src, struct binbuffer *dst) +static int gif_extract_image(struct binbuffer *src, struct binbuffer *dst) { unsigned char c; - + /* * Remember the colormap flag and copy the image head */ @@ -239,26 +262,33 @@ int gif_extract_image(struct binbuffer *src, struct binbuffer *dst) */ if (c & 0x80) { - if (buf_copy(src, dst, 3 * (1 << ((c & 0x07) + 1)))) + int map_length = 3 * (1 << ((c & 0x07) + 1)); + if (map_length <= 0) { + log_error(LOG_LEVEL_DEANIMATE, + "colormap length = %d (%c)?", map_length, c); return 1; - } + } + if (buf_copy(src, dst, (size_t)map_length)) + { + return 1; + } } if (buf_copy(src, dst, 1)) return 1; /* * Copy the image chunk by chunk. */ - while(c = buf_getbyte(src, 0)) + while((c = buf_getbyte(src, 0)) != '\0') { - if (buf_copy(src, dst, c + 1)) return 1; + if (buf_copy(src, dst, 1 + (size_t) c)) return 1; } if (buf_copy(src, dst, 1)) return 1; /* * Trim and rewind the dst buffer */ - dst->buffer = (char *)realloc(dst->buffer, dst->offset); + if (NULL == (dst->buffer = (char *)realloc(dst->buffer, dst->offset))) return 1; dst->size = dst->offset; dst->offset = 0; @@ -267,24 +297,26 @@ int gif_extract_image(struct binbuffer *src, struct binbuffer *dst) } /********************************************************************* - * + * * Function : gif_deanimate * * Description : Deanimate a given GIF image, i.e. given a GIF with * an (optional) image block and an arbitrary number * of image extension blocks, produce an output GIF with * only one image block that contains the last image - * (extenstion) block of the original. - * Also strip Comments, Application extenstions, etc. + * (extension) block of the original. + * Also strip Comments, Application extensions, etc. * * Parameters : * 1 : src = Pointer to the source binbuffer * 2 : dst = Pointer to the destination binbuffer + * 3 : get_first_image = Flag: If set, get the first image + * If unset (default), get the last * - * Returns : 0 on success, or 1 on failiure + * Returns : 0 on success, or 1 on failure * *********************************************************************/ -int gif_deanimate(struct binbuffer *src, struct binbuffer *dst) +int gif_deanimate(struct binbuffer *src, struct binbuffer *dst, int get_first_image) { unsigned char c; struct binbuffer *image; @@ -297,11 +329,10 @@ int gif_deanimate(struct binbuffer *src, struct binbuffer *dst) c = buf_getbyte(src, 10); /* - * Check & copy GIF header + * Check & copy GIF header */ - if (strncmp(src->buffer, "GIF89a", 6)) + if (strncmp(src->buffer, "GIF89a", 6) && strncmp(src->buffer, "GIF87a", 6)) { - fprintf(stderr, "This is not a GIF98a!\n"); return 1; } else @@ -315,9 +346,16 @@ int gif_deanimate(struct binbuffer *src, struct binbuffer *dst) /* * Look for global colormap and copy if found. */ - if(c & 0x80) + if (c & 0x80) { - if (buf_copy(src, dst, 3 * (1 << ((c & 0x07) + 1)))) + int map_length = 3 * (1 << ((c & 0x07) + 1)); + if (map_length <= 0) + { + log_error(LOG_LEVEL_DEANIMATE, + "colormap length = %d (%c)?", map_length, c); + return 1; + } + if (buf_copy(src, dst, (size_t)map_length)) { return 1; } @@ -326,10 +364,7 @@ int gif_deanimate(struct binbuffer *src, struct binbuffer *dst) /* * Reserve a buffer for the current image block */ - if (NULL == (image = (struct binbuffer *)zalloc(sizeof(*image)))) - { - return 1; - } + image = zalloc_or_die(sizeof(*image)); /* * Parse the GIF block by block and copy the relevant @@ -343,22 +378,15 @@ int gif_deanimate(struct binbuffer *src, struct binbuffer *dst) * End-of-GIF Marker: Append current image and return */ case 0x3b: - if (buf_copy(image, dst, image->size) || buf_copy(src, dst, 1)) - { - goto failed; - } - buf_free(image); - return(0); + goto write; - /* - * Image block: Extract to current image buffer + /* + * Image block: Extract to current image buffer. */ case 0x2c: image->offset = 0; - if (gif_extract_image(src, image)) - { - goto failed; - } + if (gif_extract_image(src, image)) goto failed; + if (get_first_image) goto write; continue; /* @@ -375,6 +403,7 @@ int gif_deanimate(struct binbuffer *src, struct binbuffer *dst) image->offset = 0; if (buf_copy(src, image, 8) || buf_getbyte(src, 0) != 0x2c) goto failed; if (gif_extract_image(src, image)) goto failed; + if (get_first_image) goto write; continue; /* @@ -411,13 +440,13 @@ int gif_deanimate(struct binbuffer *src, struct binbuffer *dst) */ default: goto failed; - + } } /* -END- while src */ /* * Either we got here by goto, or because the GIF is - * bogus and EOF was reached before an end-of-gif marker + * bogus and EOF was reached before an end-of-gif marker * was found. */ @@ -425,6 +454,17 @@ failed: buf_free(image); return 1; + /* + * Append the current image to dst and return + */ + +write: + if (buf_copy(image, dst, image->size)) goto failed; + if (buf_extend(dst, 1)) goto failed; + *(dst->buffer + dst->offset++) = 0x3b; + buf_free(image); + return 0; + }