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libpng/contrib/libtests/pngunknown.c
Glenn Randers-Pehrson 702053d110 [libpng16] Bump version to 1.6.0beta28
2012-08-17 21:54:45 -05:00

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/* pngunknown.c - test the read side unknown chunk handling
*
* Last changed in libpng 1.6.0 [(PENDING RELEASE)]
* Copyright (c) 2012 Glenn Randers-Pehrson
* Written by John Cunningham Bowler
*
* This code is released under the libpng license.
* For conditions of distribution and use, see the disclaimer
* and license in png.h
*
* NOTES:
* This is a C program that is intended to be linked against libpng. It
* allows the libpng unknown handling code to be tested by interpreting
* arguments to save or discard combinations of chunks. The program is
* currently just a minimal validation for the built-in libpng facilities.
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <png.h>
#ifdef PNG_READ_SUPPORTED
#if PNG_LIBPNG_VER < 10500
/* This deliberately lacks the PNG_CONST. */
typedef png_byte *png_const_bytep;
/* This is copied from 1.5.1 png.h: */
#define PNG_INTERLACE_ADAM7_PASSES 7
#define PNG_PASS_START_ROW(pass) (((1U&~(pass))<<(3-((pass)>>1)))&7)
#define PNG_PASS_START_COL(pass) (((1U& (pass))<<(3-(((pass)+1)>>1)))&7)
#define PNG_PASS_ROW_SHIFT(pass) ((pass)>2?(8-(pass))>>1:3)
#define PNG_PASS_COL_SHIFT(pass) ((pass)>1?(7-(pass))>>1:3)
#define PNG_PASS_ROWS(height, pass) (((height)+(((1<<PNG_PASS_ROW_SHIFT(pass))\
-1)-PNG_PASS_START_ROW(pass)))>>PNG_PASS_ROW_SHIFT(pass))
#define PNG_PASS_COLS(width, pass) (((width)+(((1<<PNG_PASS_COL_SHIFT(pass))\
-1)-PNG_PASS_START_COL(pass)))>>PNG_PASS_COL_SHIFT(pass))
#define PNG_ROW_FROM_PASS_ROW(yIn, pass) \
(((yIn)<<PNG_PASS_ROW_SHIFT(pass))+PNG_PASS_START_ROW(pass))
#define PNG_COL_FROM_PASS_COL(xIn, pass) \
(((xIn)<<PNG_PASS_COL_SHIFT(pass))+PNG_PASS_START_COL(pass))
#define PNG_PASS_MASK(pass,off) ( \
((0x110145AFU>>(((7-(off))-(pass))<<2)) & 0xFU) | \
((0x01145AF0U>>(((7-(off))-(pass))<<2)) & 0xF0U))
#define PNG_ROW_IN_INTERLACE_PASS(y, pass) \
((PNG_PASS_MASK(pass,0) >> ((y)&7)) & 1)
#define PNG_COL_IN_INTERLACE_PASS(x, pass) \
((PNG_PASS_MASK(pass,1) >> ((x)&7)) & 1)
/* These are needed too for the default build: */
#define PNG_WRITE_16BIT_SUPPORTED
#define PNG_READ_16BIT_SUPPORTED
/* This comes from pnglibconf.h afer 1.5: */
#define PNG_FP_1 100000
#define PNG_GAMMA_THRESHOLD_FIXED\
((png_fixed_point)(PNG_GAMMA_THRESHOLD * PNG_FP_1))
#endif
#if PNG_LIBPNG_VER < 10600
/* 1.6.0 constifies many APIs. The following exists to allow pngvalid to be
* compiled against earlier versions.
*/
# define png_const_structp png_structp
#endif
/* Copied from pngpriv.h */
#define PNG_32b(b,s) ((png_uint_32)(b) << (s))
#define PNG_CHUNK(b1,b2,b3,b4) \
(PNG_32b(b1,24) | PNG_32b(b2,16) | PNG_32b(b3,8) | PNG_32b(b4,0))
#define png_IHDR PNG_CHUNK( 73, 72, 68, 82)
#define png_IDAT PNG_CHUNK( 73, 68, 65, 84)
#define png_IEND PNG_CHUNK( 73, 69, 78, 68)
#define png_PLTE PNG_CHUNK( 80, 76, 84, 69)
#define png_bKGD PNG_CHUNK( 98, 75, 71, 68)
#define png_cHRM PNG_CHUNK( 99, 72, 82, 77)
#define png_gAMA PNG_CHUNK(103, 65, 77, 65)
#define png_hIST PNG_CHUNK(104, 73, 83, 84)
#define png_iCCP PNG_CHUNK(105, 67, 67, 80)
#define png_iTXt PNG_CHUNK(105, 84, 88, 116)
#define png_oFFs PNG_CHUNK(111, 70, 70, 115)
#define png_pCAL PNG_CHUNK(112, 67, 65, 76)
#define png_sCAL PNG_CHUNK(115, 67, 65, 76)
#define png_pHYs PNG_CHUNK(112, 72, 89, 115)
#define png_sBIT PNG_CHUNK(115, 66, 73, 84)
#define png_sPLT PNG_CHUNK(115, 80, 76, 84)
#define png_sRGB PNG_CHUNK(115, 82, 71, 66)
#define png_sTER PNG_CHUNK(115, 84, 69, 82)
#define png_tEXt PNG_CHUNK(116, 69, 88, 116)
#define png_tIME PNG_CHUNK(116, 73, 77, 69)
#define png_tRNS PNG_CHUNK(116, 82, 78, 83)
#define png_zTXt PNG_CHUNK(122, 84, 88, 116)
#define png_vpAg PNG_CHUNK('v', 'p', 'A', 'g')
/* Test on flag values as defined in the spec (section 5.4): */
#define PNG_CHUNK_ANCILLARY(c ) (1 & ((c) >> 29))
#define PNG_CHUNK_CRITICAL(c) (!PNG_CHUNK_ANCILLARY(c))
#define PNG_CHUNK_PRIVATE(c) (1 & ((c) >> 21))
#define PNG_CHUNK_RESERVED(c) (1 & ((c) >> 13))
#define PNG_CHUNK_SAFE_TO_COPY(c) (1 & ((c) >> 5))
/* Chunk information */
#define PNG_INFO_tEXt 0x10000000U
#define PNG_INFO_iTXt 0x20000000U
#define PNG_INFO_zTXt 0x40000000U
#define PNG_INFO_sTER 0x01000000U
#define PNG_INFO_vpAg 0x02000000U
#define ABSENT 0
#define START 1
#define END 2
static struct
{
char name[5];
png_uint_32 flag;
png_uint_32 tag;
int unknown; /* Chunk not known to libpng */
int all; /* Chunk set by the '-1' option */
int position; /* position in pngtest.png */
int keep; /* unknown handling setting */
} chunk_info[] = {
/* Critical chunks */
{ "IDAT", PNG_INFO_IDAT, png_IDAT, 0, 0, START, 0 }, /* must be [0] */
{ "PLTE", PNG_INFO_PLTE, png_PLTE, 0, 0, ABSENT, 0 },
/* Non-critical chunks that libpng handles */
{ "bKGD", PNG_INFO_bKGD, png_bKGD, 0, 1, START, 0 },
{ "cHRM", PNG_INFO_cHRM, png_cHRM, 0, 1, START, 0 },
{ "gAMA", PNG_INFO_gAMA, png_gAMA, 0, 1, START, 0 },
{ "hIST", PNG_INFO_hIST, png_hIST, 0, 1, ABSENT, 0 },
{ "iCCP", PNG_INFO_iCCP, png_iCCP, 0, 1, ABSENT, 0 },
{ "iTXt", PNG_INFO_iTXt, png_iTXt, 0, 1, ABSENT, 0 },
{ "oFFs", PNG_INFO_oFFs, png_oFFs, 0, 1, START, 0 },
{ "pCAL", PNG_INFO_pCAL, png_pCAL, 0, 1, START, 0 },
{ "pHYs", PNG_INFO_pHYs, png_pHYs, 0, 1, START, 0 },
{ "sBIT", PNG_INFO_sBIT, png_sBIT, 0, 1, START, 0 },
{ "sCAL", PNG_INFO_sCAL, png_sCAL, 0, 1, START, 0 },
{ "sPLT", PNG_INFO_sPLT, png_sPLT, 0, 1, ABSENT, 0 },
{ "sRGB", PNG_INFO_sRGB, png_sRGB, 0, 1, START, 0 },
{ "tEXt", PNG_INFO_tEXt, png_tEXt, 0, 1, START, 0 },
{ "tIME", PNG_INFO_tIME, png_tIME, 0, 1, START, 0 },
{ "tRNS", PNG_INFO_tRNS, png_tRNS, 0, 0, ABSENT, 0 },
{ "zTXt", PNG_INFO_zTXt, png_zTXt, 0, 1, END, 0 },
/* No libpng handling */
{ "sTER", PNG_INFO_sTER, png_sTER, 1, 1, START, 0 },
{ "vpAg", PNG_INFO_vpAg, png_vpAg, 1, 0, START, 0 },
};
#define NINFO ((int)((sizeof chunk_info)/(sizeof chunk_info[0])))
static int
find(const char *name)
{
int i = NINFO;
while (--i >= 0)
{
if (memcmp(chunk_info[i].name, name, 4) == 0)
break;
}
return i;
}
static int
findb(const png_byte *name)
{
int i = NINFO;
while (--i >= 0)
{
if (memcmp(chunk_info[i].name, name, 4) == 0)
break;
}
return i;
}
static int
find_by_flag(png_uint_32 flag)
{
int i = NINFO;
while (--i >= 0) if (chunk_info[i].flag == flag) return i;
fprintf(stderr, "pngunknown: internal error\n");
exit(4);
}
static int
ancillary(const char *name)
{
return PNG_CHUNK_ANCILLARY(PNG_CHUNK(name[0], name[1], name[2], name[3]));
}
static int
ancillaryb(const png_byte *name)
{
return PNG_CHUNK_ANCILLARY(PNG_CHUNK(name[0], name[1], name[2], name[3]));
}
static int error_count = 0;
static int warning_count = 0;
static void
error(png_structp png_ptr, const char *message)
{
fprintf(stderr, "libpng error: %s\n", message);
exit(1);
(void)png_ptr;
}
static void
warning(png_structp png_ptr, const char *message)
{
++warning_count;
fprintf(stderr, "libpng warning: %s\n", message);
(void)png_ptr;
}
static png_uint_32
get_valid(const char *file, png_const_structp png_ptr, png_const_infop info_ptr)
{
png_uint_32 flags = png_get_valid(png_ptr, info_ptr, (png_uint_32)~0);
/* Map the text chunks back into the flags */
{
png_textp text;
png_uint_32 ntext = png_get_text(png_ptr, info_ptr, &text, NULL);
while (ntext-- > 0) switch (text[ntext].compression)
{
case -1:
flags |= PNG_INFO_tEXt;
break;
case 0:
flags |= PNG_INFO_zTXt;
break;
case 1:
case 2:
flags |= PNG_INFO_iTXt;
break;
default:
fprintf(stderr, "%s: unknown text compression %d\n", file,
text[ntext].compression);
exit(1);
}
}
return flags;
}
static png_uint_32
get_unknown(const char *file, int def, png_const_structp png_ptr,
png_const_infop info_ptr)
{
/* Create corresponding 'unknown' flags */
png_uint_32 flags = 0;
{
png_unknown_chunkp unknown;
int num_unknown = png_get_unknown_chunks(png_ptr, info_ptr, &unknown);
while (--num_unknown >= 0)
{
int chunk = findb(unknown[num_unknown].name);
/* Chunks not known to pngunknown must be validated here; since they
* must also be unknown to libpng the 'def' behavior should have been
* used.
*/
if (chunk < 0) switch (def)
{
default: /* impossible */
case PNG_HANDLE_CHUNK_AS_DEFAULT:
case PNG_HANDLE_CHUNK_NEVER:
fprintf(stderr, "%s: %s: %s: unknown chunk saved\n",
file, def ? "discard" : "default", unknown[num_unknown].name);
++error_count;
break;
case PNG_HANDLE_CHUNK_IF_SAFE:
if (!ancillaryb(unknown[num_unknown].name))
{
fprintf(stderr,
"%s: if-safe: %s: unknown critical chunk saved\n",
file, unknown[num_unknown].name);
++error_count;
break;
}
/* FALL THROUGH (safe) */
case PNG_HANDLE_CHUNK_ALWAYS:
break;
}
else
flags |= chunk_info[chunk].flag;
}
}
return flags;
}
static int
check(FILE *fp, int argc, const char **argv, png_uint_32p flags/*out*/)
{
png_structp png_ptr;
png_infop info_ptr, end_ptr;
int i, def = PNG_HANDLE_CHUNK_AS_DEFAULT, npasses, ipass;
png_uint_32 height;
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, error, warning);
if (png_ptr == NULL)
{
fprintf(stderr, "%s: could not allocate png struct\n", argv[argc]);
exit(1);
}
info_ptr = png_create_info_struct(png_ptr);
end_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL || end_ptr == NULL)
{
fprintf(stderr, "%s: could not allocate png info\n", argv[argc]);
exit(1);
}
png_init_io(png_ptr, fp);
/* Handle each argument in turn; multiple settings are possible for the same
* chunk and multiple calls will occur (the last one should override all
* preceding ones).
*/
for (i=1; i<argc; ++i)
{
const char *equals = strchr(argv[i], '=');
if (equals != NULL)
{
int chunk, option;
if (strcmp(equals+1, "default") == 0)
option = PNG_HANDLE_CHUNK_AS_DEFAULT;
else if (strcmp(equals+1, "discard") == 0)
option = PNG_HANDLE_CHUNK_NEVER;
else if (strcmp(equals+1, "if-safe") == 0)
option = PNG_HANDLE_CHUNK_IF_SAFE;
else if (strcmp(equals+1, "save") == 0)
option = PNG_HANDLE_CHUNK_ALWAYS;
else
{
fprintf(stderr, "%s: unrecognized chunk option\n", argv[i]);
exit(2);
}
switch (equals - argv[i])
{
case 4: /* chunk name */
chunk = find(argv[i]);
if (chunk >= 0)
{
/* These #if tests have the effect of skipping the arguments
* if SAVE support is unavailable - we can't do a useful test
* in this case, so we just check the arguments! This could
* be improved in the future by using the read callback.
*/
# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
png_byte name[5];
memcpy(name, chunk_info[chunk].name, 5);
png_set_keep_unknown_chunks(png_ptr, option, name, 1);
chunk_info[chunk].keep = option;
# else
(void)option;
# endif
continue;
}
break;
case 7: /* default */
if (memcmp(argv[i], "default", 7) == 0)
{
# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
png_set_keep_unknown_chunks(png_ptr, option, NULL, 0);
def = option;
# endif
continue;
}
break;
case 3: /* all */
if (memcmp(argv[i], "all", 3) == 0)
{
# ifdef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
png_set_keep_unknown_chunks(png_ptr, option, NULL, -1);
def = option;
for (chunk = 0; chunk < NINFO; ++chunk)
if (chunk_info[chunk].all)
chunk_info[chunk].keep = option;
# endif
continue;
}
break;
default: /* some misplaced = */
break;
}
}
fprintf(stderr, "%s: unrecognized chunk argument\n", argv[i]);
exit(2);
}
png_read_info(png_ptr, info_ptr);
switch (png_get_interlace_type(png_ptr, info_ptr))
{
case PNG_INTERLACE_NONE:
npasses = 1;
break;
case PNG_INTERLACE_ADAM7:
npasses = PNG_INTERLACE_ADAM7_PASSES;
break;
default:
fprintf(stderr, "%s: invalid interlace type\n", argv[argc]);
exit(1);
}
/* Skip the image data, if IDAT is not being handled then don't do this
* because it will cause a CRC error.
*/
if (chunk_info[0/*IDAT*/].keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
{
png_start_read_image(png_ptr);
height = png_get_image_height(png_ptr, info_ptr);
if (npasses > 1)
{
png_uint_32 width = png_get_image_width(png_ptr, info_ptr);
for (ipass=0; ipass<npasses; ++ipass)
{
png_uint_32 wPass = PNG_PASS_COLS(width, ipass);
if (wPass > 0)
{
png_uint_32 y;
for (y=0; y<height; ++y) if (PNG_ROW_IN_INTERLACE_PASS(y, ipass))
png_read_row(png_ptr, NULL, NULL);
}
}
} /* interlaced */
else /* not interlaced */
{
png_uint_32 y;
for (y=0; y<height; ++y)
png_read_row(png_ptr, NULL, NULL);
}
}
png_read_end(png_ptr, end_ptr);
flags[0] = get_valid(argv[argc], png_ptr, info_ptr);
flags[1] = get_unknown(argv[argc], def, png_ptr, info_ptr);
/* Only png_read_png sets PNG_INFO_IDAT! */
flags[chunk_info[0/*IDAT*/].keep != PNG_HANDLE_CHUNK_AS_DEFAULT] |=
PNG_INFO_IDAT;
flags[2] = get_valid(argv[argc], png_ptr, end_ptr);
flags[3] = get_unknown(argv[argc], def, png_ptr, end_ptr);
png_destroy_read_struct(&png_ptr, &info_ptr, &end_ptr);
return def;
}
static void
check_error(const char *file, png_uint_32 flags, const char *message)
{
while (flags)
{
png_uint_32 flag = flags & -flags;
int i = find_by_flag(flag);
fprintf(stderr, "%s: chunk %s: %s\n", file, chunk_info[i].name, message);
++error_count;
flags &= ~flag;
}
}
static void
check_handling(const char *file, int def, png_uint_32 chunks, png_uint_32 known,
png_uint_32 unknown, const char *position)
{
while (chunks)
{
png_uint_32 flag = chunks & -chunks;
int i = find_by_flag(flag);
int keep = chunk_info[i].keep;
const char *type;
const char *errorx = NULL;
if (chunk_info[i].unknown)
{
if (keep == PNG_HANDLE_CHUNK_AS_DEFAULT)
{
type = "UNKNOWN (default)";
keep = def;
}
else
type = "UNKNOWN (specified)";
if (flag & known)
errorx = "chunk processed";
else switch (keep)
{
case PNG_HANDLE_CHUNK_AS_DEFAULT:
if (flag & unknown)
errorx = "DEFAULT: unknown chunk saved";
break;
case PNG_HANDLE_CHUNK_NEVER:
if (flag & unknown)
errorx = "DISCARD: unknown chunk saved";
break;
case PNG_HANDLE_CHUNK_IF_SAFE:
if (ancillary(chunk_info[i].name))
{
if (!(flag & unknown))
errorx = "IF-SAFE: unknown ancillary chunk lost";
}
else if (flag & unknown)
errorx = "IF-SAFE: unknown critical chunk saved";
break;
case PNG_HANDLE_CHUNK_ALWAYS:
if (!(flag & unknown))
errorx = "SAVE: unknown chunk lost";
break;
default:
errorx = "internal error: bad keep";
break;
}
} /* unknown chunk */
else /* known chunk */
{
type = "KNOWN";
if (flag & known)
{
/* chunk was processed, it won't have been saved because that is
* caught below when checking for inconsistent processing.
*/
if (keep != PNG_HANDLE_CHUNK_AS_DEFAULT)
errorx = "!DEFAULT: known chunk processed";
}
else /* not processed */ switch (keep)
{
case PNG_HANDLE_CHUNK_AS_DEFAULT:
errorx = "DEFAULT: known chunk not processed";
break;
case PNG_HANDLE_CHUNK_NEVER:
if (flag & unknown)
errorx = "DISCARD: known chunk saved";
break;
case PNG_HANDLE_CHUNK_IF_SAFE:
if (ancillary(chunk_info[i].name))
{
if (!(flag & unknown))
errorx = "IF-SAFE: known ancillary chunk lost";
}
else if (flag & unknown)
errorx = "IF-SAFE: known critical chunk saved";
break;
case PNG_HANDLE_CHUNK_ALWAYS:
if (!(flag & unknown))
errorx = "SAVE: known chunk lost";
break;
default:
errorx = "internal error: bad keep (2)";
break;
}
}
if (errorx != NULL)
{
++error_count;
fprintf(stderr, "%s: %s %s %s: %s\n",
file, type, chunk_info[i].name, position, errorx);
}
chunks &= ~flag;
}
}
int
main(int argc, const char **argv)
{
FILE *fp;
png_uint_32 flags[2/*default/+options*/][4/*valid,unknown{before,after}*/];
int def, strict = 0;
const char *program = argv[0];
const char *count_argv[3];
if (argc > 1 && strcmp(argv[1], "--strict") == 0)
{
strict = 1;
--argc;
++argv;
}
if (--argc < 1)
{
fprintf(stderr, "pngunknown: usage:\n"
" %s {(CHNK|default|all)=(default|discard|if-safe|save)} testfile.png\n",
program);
exit(2);
}
# ifndef PNG_SAVE_UNKNOWN_CHUNKS_SUPPORTED
fprintf(stderr,
"pngunknown: warning: no 'save' support so arguments ignored\n");
# endif
fp = fopen(argv[argc], "rb");
if (fp == NULL)
{
perror(argv[argc]);
exit(2);
}
/* First find all the chunks, known and unknown, in the test file: */
count_argv[0] = program;
count_argv[1] = "default=save";
count_argv[2] = argv[argc];
(void)check(fp, 2, count_argv, flags[0]);
/* Now find what the various supplied options cause to change: */
rewind(fp);
def = check(fp, argc, argv, flags[1]);
fclose(fp);
/* Chunks should either be known or unknown, never both and this should apply
* whether the chunk is before or after the IDAT (actually, the app can
* probably change this by swapping the handling after the image, but this
* test does not do that.)
*/
check_error(argc[argv],
(flags[0][0]|flags[0][2]) & (flags[0][1]|flags[0][3]),
"chunk handled inconsistently in count tests");
check_error(argc[argv],
(flags[1][0]|flags[1][2]) & (flags[1][1]|flags[1][3]),
"chunk handled inconsistently in option tests");
/* Now find out what happened to each chunk before and after the IDAT and
* determine if the behavior was correct. First some basic sanity checks,
* any known chunk should be known in the original count, any unknown chunk
* should be either known or unknown in the original.
*/
{
png_uint_32 test;
test = flags[1][0] & ~flags[0][0];
check_error(argv[argc], test, "new known chunk before IDAT");
test = flags[1][1] & ~(flags[0][0] | flags[0][1]);
check_error(argv[argc], test, "new unknown chunk before IDAT");
test = flags[1][2] & ~flags[0][2];
check_error(argv[argc], test, "new known chunk after IDAT");
test = flags[1][3] & ~(flags[0][2] | flags[0][3]);
check_error(argv[argc], test, "new unknown chunk after IDAT");
}
/* Now each chunk in the original list should have been handled according to
* the options set for that chunk, regardless of whether libpng knows about
* it or not.
*/
check_handling(argv[argc], def, flags[0][0] | flags[0][1], flags[1][0],
flags[1][1], "before IDAT");
check_handling(argv[argc], def, flags[0][2] | flags[0][3], flags[1][2],
flags[1][3], "after IDAT");
return error_count + (strict ? warning_count : 0);
}
#else
int
main(void)
{
fprintf(stderr,
" test ignored because libpng was not built with unknown chunk support\n");
return 0;
}
#endif
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