diff options
Diffstat (limited to 'lib/libpgm1.c')
| -rw-r--r-- | lib/libpgm1.c | 126 |
1 files changed, 78 insertions, 48 deletions
diff --git a/lib/libpgm1.c b/lib/libpgm1.c index 9ef5d2c1..0656e1e0 100644 --- a/lib/libpgm1.c +++ b/lib/libpgm1.c @@ -14,7 +14,7 @@ offset stuff. */ #define _FILE_OFFSET_BITS 64 -#define _LARGE_FILES +#define _LARGE_FILES #include <string.h> #include <stdio.h> @@ -47,7 +47,7 @@ pgm_allocrow(unsigned int const cols) { -void +void pgm_init(int * const argcP, char ** const argv) { @@ -65,22 +65,21 @@ pgm_nextimage(FILE * const file, void -pgm_readpgminitrest(FILE * const fileP, - int * const colsP, - int * const rowsP, +pgm_readpgminitrest(FILE * const ifP, + int * const colsP, + int * const rowsP, gray * const maxvalP) { gray maxval; - + /* Read size. */ - *colsP = (int)pm_getuint(fileP); - *rowsP = (int)pm_getuint(fileP); + pbm_readpbminitrest(ifP, colsP, rowsP); /* Read maxval. */ - maxval = pm_getuint(fileP); + maxval = pm_getuint(ifP); if (maxval > PGM_OVERALLMAXVAL) pm_error("maxval of input image (%u) is too large. " - "The maximum allowed by PGM is %u.", + "The maximum allowed by the format is %u.", maxval, PGM_OVERALLMAXVAL); if (maxval == 0) pm_error("maxval of input image is zero."); @@ -90,9 +89,9 @@ pgm_readpgminitrest(FILE * const fileP, -static void -validateComputableSize(unsigned int const cols, - unsigned int const rows) { +void +pgm_validateComputableSize(unsigned int const cols, + unsigned int const rows) { /*---------------------------------------------------------------------------- Validate that the dimensions of the image are such that it can be processed in typical ways on this machine without worrying about @@ -116,8 +115,34 @@ validateComputableSize(unsigned int const cols, void +pgm_validateComputableMaxval(gray const maxval) { +/*---------------------------------------------------------------------------- + This is similar to validateComputableSize, but for the maxval. +-----------------------------------------------------------------------------*/ + /* Code sometimes allocates an array indexed by sample values and + represents the size of that array as an INT. (UNSIGNED INT would be + more proper, but there's no need to be that permissive). + + Code also sometimes iterates through sample values and quits when the + value is greater than the maxval. + + Code often divides by the maxval, but we don't have to check for maxval + == 0 as a computability problem because that is not a valid maxval. + + Note that in the PNM Plain formats, there is no upper limit for a + maxval, though the 'gray' type does constrain what has been passed to + us. + */ + + if (maxval > INT_MAX-1) + pm_error("Maxval (%u) is too large to be processed", maxval); +} + + + +void pgm_readpgminit(FILE * const fileP, - int * const colsP, + int * const colsP, int * const rowsP, gray * const maxvalP, int * const formatP) { @@ -130,7 +155,7 @@ pgm_readpgminit(FILE * const fileP, case PBM_TYPE: *formatP = realFormat; pbm_readpbminitrest(fileP, colsP, rowsP); - + /* Mathematically, it makes the most sense for the maxval of a PBM file seen as a PGM to be 1. But we tried this for a while and found that it causes unexpected results and frequent need for a @@ -139,14 +164,14 @@ pgm_readpgminit(FILE * const fileP, there's no in-between value to use when maxval is 1. It's really hard even to discover that your lack of Pnmdepth is your problem. So we pick 255, which is the most common PGM maxval, and the highest - resolution you can get without increasing the size of the PGM + resolution you can get without increasing the size of the PGM image. So this means some programs that are capable of exploiting the bi-level nature of a PBM file must be PNM programs instead of PGM programs. */ - + *maxvalP = PGM_MAXMAXVAL; break; @@ -154,7 +179,7 @@ pgm_readpgminit(FILE * const fileP, *formatP = realFormat; pgm_readpgminitrest(fileP, colsP, rowsP, maxvalP); break; - + case PPM_TYPE: pm_error("Input file is a PPM, which this program cannot process. " "You may want to convert it to PGM with 'ppmtopgm'"); @@ -171,18 +196,20 @@ pgm_readpgminit(FILE * const fileP, pm_error("bad magic number 0x%x - not a PPM, PGM, PBM, or PAM file", realFormat); } - validateComputableSize(*colsP, *rowsP); + pgm_validateComputableSize(*colsP, *rowsP); + + pgm_validateComputableMaxval(*maxvalP); } static void -validateRpgmRow(gray * const grayrow, +validateRpgmRow(gray * const grayrow, unsigned int const cols, gray const maxval, const char ** const errorP) { /*---------------------------------------------------------------------------- - Check for sample values above maxval in input. + Check for sample values above maxval in input. Note: a program that wants to deal with invalid sample values itself can simply make sure it uses a sufficiently high maxval on the read function @@ -205,23 +232,23 @@ validateRpgmRow(gray * const grayrow, } *errorP = NULL; } -} +} static void readRpgmRow(FILE * const fileP, - gray * const grayrow, + gray * const grayrow, int const cols, gray const maxval, int const format) { unsigned int const bytesPerSample = maxval < 256 ? 1 : 2; int const bytesPerRow = cols * bytesPerSample; - + unsigned char * rowBuffer; const char * error; - + MALLOCARRAY(rowBuffer, bytesPerRow); if (rowBuffer == NULL) pm_asprintf(&error, "Unable to allocate memory for row buffer " @@ -243,19 +270,19 @@ readRpgmRow(FILE * const fileP, } else { unsigned int bufferCursor; unsigned int col; - + bufferCursor = 0; /* Start at beginning of rowBuffer[] */ - + for (col = 0; col < cols; ++col) { gray g; - + g = rowBuffer[bufferCursor++] << 8; g |= rowBuffer[bufferCursor++]; - + grayrow[col] = g; } } - validateRpgmRow(grayrow, cols, maxval, &error); + validateRpgmRow(grayrow, cols, maxval, &error); } free(rowBuffer); } @@ -264,13 +291,13 @@ readRpgmRow(FILE * const fileP, pm_strfree(error); pm_longjmp(); } -} +} static void readPbmRow(FILE * const fileP, - gray * const grayrow, + gray * const grayrow, int const cols, gray const maxval, int const format) { @@ -278,7 +305,7 @@ readPbmRow(FILE * const fileP, jmp_buf jmpbuf; jmp_buf * origJmpbufP; bit * bitrow; - + bitrow = pbm_allocrow_packed(cols); if (setjmp(jmpbuf) != 0) { pbm_freerow(bitrow); @@ -306,7 +333,7 @@ readPbmRow(FILE * const fileP, void pgm_readpgmrow(FILE * const fileP, - gray * const grayrow, + gray * const grayrow, int const cols, gray const maxval, int const format) { @@ -322,16 +349,16 @@ pgm_readpgmrow(FILE * const fileP, } } break; - + case RPGM_FORMAT: readRpgmRow(fileP, grayrow, cols, maxval, format); break; - + case PBM_FORMAT: case RPBM_FORMAT: readPbmRow(fileP, grayrow, cols, maxval, format); break; - + default: pm_error("can't happen"); } @@ -342,7 +369,7 @@ pgm_readpgmrow(FILE * const fileP, gray ** pgm_readpgm(FILE * const fileP, int * const colsP, - int * const rowsP, + int * const rowsP, gray * const maxvalP) { gray ** grays; @@ -353,7 +380,7 @@ pgm_readpgm(FILE * const fileP, jmp_buf * origJmpbufP; pgm_readpgminit(fileP, &cols, &rows, &maxval, &format); - + grays = pgm_allocarray(cols, rows); if (setjmp(jmpbuf) != 0) { @@ -362,7 +389,7 @@ pgm_readpgm(FILE * const fileP, pm_longjmp(); } else { unsigned int row; - + pm_setjmpbufsave(&jmpbuf, &origJmpbufP); for (row = 0; row < rows; ++row) @@ -379,11 +406,11 @@ pgm_readpgm(FILE * const fileP, void -pgm_check(FILE * const file, - enum pm_check_type const checkType, - int const format, - int const cols, - int const rows, +pgm_check(FILE * const file, + enum pm_check_type const checkType, + int const format, + int const cols, + int const rows, gray const maxval, enum pm_check_code * const retvalP) { @@ -391,7 +418,7 @@ pgm_check(FILE * const file, pm_error("Invalid number of rows passed to pgm_check(): %d", rows); if (cols < 0) pm_error("Invalid number of columns passed to pgm_check(): %d", cols); - + if (checkType != PM_CHECK_BASIC) { if (retvalP) *retvalP = PM_CHECK_UNKNOWN_TYPE; @@ -400,10 +427,13 @@ pgm_check(FILE * const file, } else if (format != RPGM_FORMAT) { if (retvalP) *retvalP = PM_CHECK_UNCHECKABLE; - } else { + } else { pm_filepos const bytesPerRow = cols * (maxval > 255 ? 2 : 1); pm_filepos const needRasterSize = rows * bytesPerRow; - + pm_check(file, checkType, needRasterSize, retvalP); } } + + + |