util.c

//
//  util.h
//  dloadtool
//
//  Created by Joshua Hill on 1/31/13.
//
//

#ifndef __dloadtool__util__
#define __dloadtool__util__


#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>

#include "util.h"

void hexdump (unsigned char *data, unsigned int amount) {
    unsigned int    dp, p;  /* data pointer */
    const char      trans[] =
    "................................ !\"#$%&'()*+,-./0123456789"
    ":;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklm"
    "nopqrstuvwxyz{|}~...................................."
    "....................................................."
    "........................................";
    
    
    for (dp = 1; dp <= amount; dp++) {
        fprintf (stderr, "%02x ", data[dp-1]);
        if ((dp % 8) == 0)
            fprintf (stderr, " ");
        if ((dp % 16) == 0) {
            fprintf (stderr, "| ");
            p = dp;
            for (dp -= 16; dp < p; dp++)
                fprintf (stderr, "%c", trans[data[dp]]);
            fflush (stderr);
            fprintf (stderr, "\n");
        }
        fflush (stderr);
    }
    // tail
    if ((amount % 16) != 0) {
        p = dp = 16 - (amount % 16);
        for (dp = p; dp > 0; dp--) {
            fprintf (stderr, "   ");
            if (((dp % 8) == 0) && (p != 8))
                fprintf (stderr, " ");
            fflush (stderr);
        }
        fprintf (stderr, " | ");
        for (dp = (amount - (16 - p)); dp < amount; dp++)
            fprintf (stderr, "%c", trans[data[dp]]);
        fflush (stderr);
    }
    fprintf (stderr, "\n");
    
    return;
}

uint16_t flip_endian16(uint16_t value) {
    uint16_t result = 0;
    result |= (value & 0xFF) << 8;
    result |= (value & 0xFF00) >> 8;
    return result;
}

uint32_t flip_endian32(uint32_t value) {
    uint32_t result = 0;
    result |= (value & 0xFF) << 24;
    result |= (value & 0xFF00) << 8;
    result |= (value & 0xFF0000) >> 8;
    result |= (value & 0xFF000000) >> 24;
    return result;
}

uint64_t flip_endian64(uint64_t value) {
  uint64_t result = 0;
  result |= (value & 0xFF) << 56;
  result |= (value & 0xFF00) << 40;
  result |= (value & 0xFF0000) << 24;
  result |= (value & 0xFF000000) << 8;
  result |= (value & 0xFF00000000) >> 8;
  result |= (value & 0xFF0000000000) >> 24;
  result |= (value & 0xFF000000000000) >> 40;
  result |= (value & 0xFF00000000000000) >> 56;
  return result;
}

/* QCDM protocol frames are pseudo Async HDLC frames which end with a 3-byte
 * trailer.  This trailer consists of the 16-bit CRC of the frame plus an ending
 * "async control character" whose value is 0x7E.  The frame *and* the CRC are
 * escaped before adding the trailing control character so that the control
 * character (0x7E) and the escape marker (0x7D) are never seen in the frame.
 */

/* Table of CRCs for each possible byte, with a generator polynomial of 0x8408 */
static const u_int16_t crc_table[256] = {
    0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
    0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
    0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
    0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
    0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
    0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
    0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
    0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
    0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
    0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
    0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
    0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
    0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
    0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
    0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
    0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
    0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
    0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
    0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
    0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
    0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
    0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
    0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
    0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
    0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
    0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
    0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
    0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
    0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
    0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
    0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
    0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};

/* Calculate the CRC for a buffer using a seed of 0xffff */
u_int16_t dm_crc16 (const char *buffer, size_t len) {
    u_int16_t crc = 0xffff;
    
    while (len--)
        crc = crc_table[(crc ^ *buffer++) & 0xff] ^ (crc >> 8);
    return ~crc;
}


#endif /* defined(__dloadtool__util__) */