/*****************************************************************************\ * hexdump.c \*****************************************************************************/ #include "hexdump.h" /* hexdump.c * * Copyright (C) 2002 * David S. Peterson. All rights reserved. * * Author: David S. Peterson * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions, and the entire permission notice, including * the following disclaimer of warranties. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions, and the entire permission notice, * including the following disclaimer in the documentation and/or other * materials provided with the distribution. * 3. The name(s) of the author(s) may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * ALTERNATIVELY, this product may be distributed under the terms of the GNU * General Public License, in which case the provisions of the GPL are * required INSTEAD OF the above restrictions. (This clause is necessary due * to a potential bad interaction between the GPL and the restrictions * contained in a BSD-style copyright.) * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ static void addrprint(FILE * outfile, uint64_t address, int width); static void hexprint(FILE * outfile, unsigned char byte); static void charprint(FILE * outfile, unsigned char byte, unsigned char nonprintable, is_printable_fn_t is_printable_fn); /*-------------------------------------------------------------------------- * hexdump * * Write a hex dump of 'mem' to 'outfile'. * * parameters: * mem: a pointer to the memory to display * bytes: the number of bytes of data to display * addrprint_start: The address to associate with the first byte of * data. For instance, a value of 0 indicates that the * first byte displayed should be labeled as byte 0. * outfile: The place where the hex dump should be written. * For instance, stdout or stderr may be passed here. * format: A structure specifying how the hex dump should be * formatted. *--------------------------------------------------------------------------*/ void hexdump(const void *mem, int bytes, uint64_t addrprint_start, FILE * outfile, const hexdump_format_t * format) { int bytes_left, index, i; const unsigned char *p; is_printable_fn_t is_printable_fn; /* Quietly return if the caller asks us to do something unreasonable. */ if ((format->bytes_per_line <= 0) || (bytes < 0)) return; is_printable_fn = format->is_printable_fn; if (is_printable_fn == NULL) is_printable_fn = default_is_printable_fn; p = (const unsigned char *)mem; index = 0; /* Each iteration handles one full line of output. When loop * terminates, the number of remaining bytes to display (if any) * will not be enough to fill an entire line. */ for (bytes_left = bytes; bytes_left >= format->bytes_per_line; bytes_left -= format->bytes_per_line) { /* print start address for current line */ fprintf(outfile, format->indent); addrprint(outfile, addrprint_start + index, format->addrprint_width); fprintf(outfile, format->sep1); /* display the bytes in hex */ for (i = 0;;) { hexprint(outfile, p[index++]); if (++i >= format->bytes_per_line) break; fprintf(outfile, format->sep2); } index -= format->bytes_per_line; fprintf(outfile, format->sep3); /* display the bytes as characters */ for (i = 0; i < format->bytes_per_line; i++) charprint(outfile, p[index++], format->nonprintable, is_printable_fn); fprintf(outfile, "\n"); } if (bytes_left == 0) return; /* print start address for last line */ fprintf(outfile, format->indent); addrprint(outfile, addrprint_start + index, format->addrprint_width); fprintf(outfile, format->sep1); /* display bytes for last line in hex */ for (i = 0; i < bytes_left; i++) { hexprint(outfile, p[index++]); fprintf(outfile, format->sep2); } index -= bytes_left; /* pad the rest of the hex byte area with spaces */ for (;;) { fprintf(outfile, " "); if (++i >= format->bytes_per_line) break; fprintf(outfile, format->sep2); } fprintf(outfile, format->sep3); /* display bytes for last line as characters */ for (i = 0; i < bytes_left; i++) charprint(outfile, p[index++], format->nonprintable, is_printable_fn); /* pad the rest of the character area with spaces */ for (; i < format->bytes_per_line; i++) fprintf(outfile, " "); fprintf(outfile, "\n"); } /*-------------------------------------------------------------------------- * default_is_printable_fn * * Determine whether the input character is printable. The proper behavior * for this type of function may be system-dependent. This function takes a * conservative approach. If it is not adequate for your purposes, you can * write your own. * * parameters: * c: the input character * * return value: * Return 1 if the input character is printable. Otherwise return 0. *--------------------------------------------------------------------------*/ int default_is_printable_fn(unsigned char c) { return (c >= 0x20) && (c <= 0x7e); } /*-------------------------------------------------------------------------- * addrprint * * Display an address as a hexadecimal number. * * parameters: * outfile: the place where the output should be written * address: the address to display * width: The number of bytes wide the address should be displayed as. * Must be a value from 1 to 8. *--------------------------------------------------------------------------*/ static void addrprint(FILE * outfile, uint64_t address, int width) { char s[17]; int i; /* force the user's input to be valid */ if (width < 1) width = 1; else if (width > 8) width = 8; /* convert address to string */ sprintf(s, "%016llx", (unsigned long long)address); /* write it out, with colons separating consecutive 16-bit * chunks of the address */ for (i = 16 - (2 * width);;) { fprintf(outfile, "%c", s[i]); if (++i >= 16) break; if ((i % 4) == 0) fprintf(outfile, ":"); } } /*-------------------------------------------------------------------------- * hexprint * * Display a byte as a two digit hex value. * * parameters: * outfile: the place where the output should be written * byte: the byte to display *--------------------------------------------------------------------------*/ static void hexprint(FILE * outfile, unsigned char byte) { static const char tbl[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; fprintf(outfile, "%c%c", tbl[byte >> 4], tbl[byte & 0x0f]); } /*-------------------------------------------------------------------------- * charprint * * Display a byte as its character representation. * * parameters: * outfile: the place where the output should be written * byte: the byte to display * nonprintable: a substitute character to display if the byte * represents a nonprintable character * is_printable_fn: a function that returns a boolean value indicating * whether a given character is printable *--------------------------------------------------------------------------*/ static void charprint(FILE * outfile, unsigned char byte, unsigned char nonprintable, is_printable_fn_t is_printable_fn) { fprintf(outfile, "%c", is_printable_fn(byte) ? byte : nonprintable); }