diff options
Diffstat (limited to 'lib/libpgm1.c')
| -rw-r--r-- | lib/libpgm1.c | 104 |
1 files changed, 74 insertions, 30 deletions
diff --git a/lib/libpgm1.c b/lib/libpgm1.c index 4d93e4be..9ef5d2c1 100644 --- a/lib/libpgm1.c +++ b/lib/libpgm1.c @@ -20,6 +20,9 @@ #include <stdio.h> #include <errno.h> +#include "netpbm/mallocvar.h" +#include "netpbm/nstring.h" + #include "pgm.h" #include "libpgm.h" #include "pbm.h" @@ -27,8 +30,6 @@ #include "pam.h" #include "libpam.h" #include "fileio.h" -#include "mallocvar.h" -#include "nstring.h" gray * @@ -100,10 +101,13 @@ validateComputableSize(unsigned int const cols, you expect. That failed expectation can be disastrous if you use it to allocate memory. + It is very normal to allocate space for a pixel row, so we make sure + the size of a pixel row, in bytes, can be represented by an 'int'. + A common operation is adding 1 or 2 to the highest row or column number in the image, so we make sure that's possible. -----------------------------------------------------------------------------*/ - if (cols > INT_MAX - 2) + if (cols > INT_MAX / (sizeof(gray)) || cols > INT_MAX - 2) pm_error("image width (%u) too large to be processed", cols); if (rows > INT_MAX - 2) pm_error("image height (%u) too large to be processed", rows); @@ -164,7 +168,8 @@ pgm_readpgminit(FILE * const fileP, break; default: - pm_error("bad magic number - not a Netpbm file"); + pm_error("bad magic number 0x%x - not a PPM, PGM, PBM, or PAM file", + realFormat); } validateComputableSize(*colsP, *rowsP); } @@ -172,11 +177,44 @@ pgm_readpgminit(FILE * const fileP, static void +validateRpgmRow(gray * const grayrow, + unsigned int const cols, + gray const maxval, + const char ** const errorP) { +/*---------------------------------------------------------------------------- + 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 + call, so this validation never fails. +-----------------------------------------------------------------------------*/ + if (maxval == 255 || maxval == 65535) { + /* There's no way a sample can be invalid, so we don't need to look at + the samples individually. + */ + *errorP = NULL; + } else { + unsigned int col; + for (col = 0; col < cols; ++col) { + if (grayrow[col] > maxval) { + pm_asprintf(errorP, + "gray value %u is greater than maxval (%u)", + grayrow[col], maxval); + return; + } + } + *errorP = NULL; + } +} + + + +static void readRpgmRow(FILE * const fileP, - gray * const grayrow, - int const cols, - gray const maxval, - int const format) { + 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; @@ -186,19 +224,18 @@ readRpgmRow(FILE * const fileP, MALLOCARRAY(rowBuffer, bytesPerRow); if (rowBuffer == NULL) - asprintfN(&error, "Unable to allocate memory for row buffer " - "for %u columns", cols); + pm_asprintf(&error, "Unable to allocate memory for row buffer " + "for %u columns", cols); else { - ssize_t rc; + size_t rc; rc = fread(rowBuffer, 1, bytesPerRow, fileP); if (rc == 0) - asprintfN(&error, "Error reading row. fread() errno=%d (%s)", - errno, strerror(errno)); + pm_asprintf(&error, "Error reading row. fread() errno=%d (%s)", + errno, strerror(errno)); else if (rc != bytesPerRow) - asprintfN(&error, "Error reading row. Short read of %u bytes " - "instead of %u", rc, bytesPerRow); + pm_asprintf(&error, "Error reading row. Short read of %u bytes " + "instead of %u", (unsigned)rc, bytesPerRow); else { - error = NULL; if (maxval < 256) { unsigned int col; for (col = 0; col < cols; ++col) @@ -218,12 +255,13 @@ readRpgmRow(FILE * const fileP, grayrow[col] = g; } } + validateRpgmRow(grayrow, cols, maxval, &error); } free(rowBuffer); } if (error) { pm_errormsg("%s", error); - strfree(error); + pm_strfree(error); pm_longjmp(); } } @@ -241,7 +279,7 @@ readPbmRow(FILE * const fileP, jmp_buf * origJmpbufP; bit * bitrow; - bitrow = pbm_allocrow(cols); + bitrow = pbm_allocrow_packed(cols); if (setjmp(jmpbuf) != 0) { pbm_freerow(bitrow); pm_setjmpbuf(origJmpbufP); @@ -251,10 +289,14 @@ readPbmRow(FILE * const fileP, pm_setjmpbufsave(&jmpbuf, &origJmpbufP); - pbm_readpbmrow(fileP, bitrow, cols, format); - for (col = 0; col < cols; ++col) - grayrow[col] = (bitrow[col] == PBM_WHITE ) ? maxval : 0; + pbm_readpbmrow_packed(fileP, bitrow, cols, format); + for (col = 0; col < cols; ++col) { + grayrow[col] = + ((bitrow[col/8] >> (7 - col%8)) & 0x1) == PBM_WHITE ? + maxval : 0 + ; + } pm_setjmpbuf(origJmpbufP); } pbm_freerow(bitrow); @@ -338,28 +380,30 @@ pgm_readpgm(FILE * const fileP, void pgm_check(FILE * const file, - enum pm_check_type const check_type, + enum pm_check_type const checkType, int const format, int const cols, int const rows, gray const maxval, - enum pm_check_code * const retval_p) { + enum pm_check_code * const retvalP) { if (rows < 0) 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 (check_type != PM_CHECK_BASIC) { - if (retval_p) *retval_p = PM_CHECK_UNKNOWN_TYPE; + if (checkType != PM_CHECK_BASIC) { + if (retvalP) + *retvalP = PM_CHECK_UNKNOWN_TYPE; } else if (PGM_FORMAT_TYPE(format) == PBM_TYPE) { - pbm_check(file, check_type, format, cols, rows, retval_p); + pbm_check(file, checkType, format, cols, rows, retvalP); } else if (format != RPGM_FORMAT) { - if (retval_p) *retval_p = PM_CHECK_UNCHECKABLE; + if (retvalP) + *retvalP = PM_CHECK_UNCHECKABLE; } else { - pm_filepos const bytes_per_row = cols * (maxval > 255 ? 2 : 1); - pm_filepos const need_raster_size = rows * bytes_per_row; + pm_filepos const bytesPerRow = cols * (maxval > 255 ? 2 : 1); + pm_filepos const needRasterSize = rows * bytesPerRow; - pm_check(file, check_type, need_raster_size, retval_p); + pm_check(file, checkType, needRasterSize, retvalP); } } |