/**
 * Copyright (c) 2012, PICHOT Fabien Paul Leonard <pichot.fabienATgmail.com>
 * Copyright (c) 2012, Tristan Le Guern <tleguern@bouledef.eu>
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 **/

#if defined Windows
#include <windows.h>
#endif
#include <ctype.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>

#include "tuntap.h"

void
tuntap_log_set_cb(t_tuntap_log cb)
{
  if(cb == NULL)
  {
    tuntap_log = tuntap_log_default;
  }
  tuntap_log = cb;
}

void
tuntap_log_default(int level, const char *errmsg)
{
  char *name;

  switch(level)
  {
    case TUNTAP_LOG_DEBUG:
      name = "Debug";
      break;
    case TUNTAP_LOG_INFO:
      name = "Info";
      break;
    case TUNTAP_LOG_NOTICE:
      name = "Notice";
      break;
    case TUNTAP_LOG_WARN:
      name = "Warning";
      break;
    case TUNTAP_LOG_ERR:
      name = "Error";
      break;
    case TUNTAP_LOG_NONE:
    default:
      name = NULL;
      break;
  }
  if(name == NULL)
  {
    (void)fprintf(stderr, "%s\n", errmsg);
  }
  else
  {
    (void)fprintf(stderr, "%s: %s\n", name, errmsg);
  }
}

void
tuntap_log_hexdump(void *data, size_t size)
{
  unsigned char *p = (unsigned char *)data;
  unsigned int c;
  size_t n;
  char bytestr[4]          = {0};
  char addrstr[10]         = {0};
  char hexstr[16 * 3 + 5]  = {0};
  char charstr[16 * 1 + 5] = {0};
  char buf[1024];

  for(n = 1; n <= size; n++)
  {
    if(n % 16 == 1)
    {
      /* store address for this line */
      snprintf(addrstr, sizeof(addrstr), "%.4lx",
               ((uintptr_t)p - (uintptr_t)data));
    }

    c = *p;
    if(isalnum(c) == 0)
    {
      c = '.';
    }

    /* store hex str (for left side) */
    snprintf(bytestr, sizeof(bytestr), "%02X ", *p);
    strncat(hexstr, bytestr, sizeof(hexstr) - strlen(hexstr) - 1);

    /* store char str (for right side) */
    snprintf(bytestr, sizeof(bytestr), "%c", c);
    strncat(charstr, bytestr, sizeof(charstr) - strlen(charstr) - 1);

    if(n % 16 == 0)
    {
      /* line completed */
      (void)memset(buf, 0, sizeof buf);
      (void)snprintf(buf, sizeof buf, "[%4.4s]   %-50.50s  %s", addrstr, hexstr,
                     charstr);
      tuntap_log(TUNTAP_LOG_NONE, buf);
      hexstr[0]  = 0;
      charstr[0] = 0;
    }
    else if(n % 8 == 0)
    {
      /* half line: add whitespaces */
      strncat(hexstr, "  ", sizeof(hexstr) - strlen(hexstr) - 1);
      strncat(charstr, " ", sizeof(charstr) - strlen(charstr) - 1);
    }
    p++; /* next byte */
  }

  /* print the rest of the buffer if not empty */
  if(strlen(hexstr) > 0)
  {
    (void)memset(buf, 0, sizeof buf);
    (void)snprintf(buf, sizeof buf, "[%4.4s]   %-50.50s  %s", addrstr, hexstr,
                   charstr);
    tuntap_log(TUNTAP_LOG_NONE, buf);
  }
}

void
tuntap_log_chksum(void *addr, int count)
{
  int sum;
  short *sptr;
  char buf[32];

  sum  = 0;
  sptr = (short *)addr;
  while(count > 1)
  {
    sum   = sum + *sptr;
    count = count - 2;
    sptr++;
  }

  addr = (char *)sptr;
  if(count > 0)
    sum = sum + *((char *)addr);
  sum = ~sum;

  (void)memset(buf, 0, sizeof buf);
  (void)snprintf(buf, sizeof buf, "Checksum of this block: %0#4x", sum);
  tuntap_log(TUNTAP_LOG_NONE, buf);
}