/*
  Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013,
  2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 Free Software
  Foundation, Inc.

  This file is part of GNU Inetutils.

  GNU Inetutils is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or (at
  your option) any later version.

  GNU Inetutils is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see `http://www.gnu.org/licenses/'. */

#include <config.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <xalloc.h>
#include <unused-parameter.h>

#include "ping_common.h"

extern unsigned char *data_buffer;
extern size_t data_length;

static void _ping_freebuf (PING * p);
extern unsigned int options;

size_t
ping_cvt_number (const char *optarg, size_t maxval, int allow_zero)
{
  char *p;
  unsigned long int n;

  n = strtoul (optarg, &p, 0);
  if (*p)
    error (EXIT_FAILURE, 0, "invalid value (`%s' near `%s')", optarg, p);

  if (n == 0 && !allow_zero)
    error (EXIT_FAILURE, 0, "option value too small: %s", optarg);

  if (maxval && n > maxval)
    error (EXIT_FAILURE, 0, "option value too big: %s", optarg);

  return n;
}

void
init_data_buffer (unsigned char * pat, size_t len)
{
  size_t i = 0;
  unsigned char *p;

  if (data_length == 0)
    return;

  data_buffer = xmalloc (data_length);

  if (pat)
    {
      for (p = data_buffer; p < data_buffer + data_length; p++)
	{
	  *p = pat[i];
	  if (++i >= len)
	    i = 0;
	}
    }
  else
    {
      for (i = 0; i < data_length; i++)
	data_buffer[i] = i;
    }
}

void
decode_pattern (const char *text, int *pattern_len,
		unsigned char *pattern_data)
{
  int i, c, off;

  for (i = 0; *text && i < *pattern_len; i++)
    {
      if (sscanf (text, "%2x%n", &c, &off) != 1)
        error (EXIT_FAILURE, 0, "error in pattern near %s", text);

      text += off;
      pattern_data[i] = c;
    }
  *pattern_len = i;
}


/*
 * tvsub --
 *	Subtract 2 timeval structs:  out = out - in.  Out is assumed to
 * be >= in.
 */
void
tvsub (struct timeval *out, struct timeval *in)
{
  if ((out->tv_usec -= in->tv_usec) < 0)
    {
      --out->tv_sec;
      out->tv_usec += 1000000;
    }
  out->tv_sec -= in->tv_sec;
}

double
nabs (double a)
{
  return (a < 0) ? -a : a;
}

double
nsqrt (double a, double prec)
{
  double x0, x1;

  if (a < 0)
    return 0;
  if (a < prec)
    return 0;
  x1 = a / 2;
  do
    {
      x0 = x1;
      x1 = (x0 + a / x0) / 2;
    }
  while (nabs (x1 - x0) > prec);

  return x1;
}

int
is_normed_time (n_time t)
{
  /* A set MSB indicates non-normalised time standard.  */
  return (t & (1UL << 31)) ? 0 : 1;
}

const char *
ping_cvt_time (char *buf, size_t buflen, n_time t)
{
  n_time t_red;

  t_red = t & ((1UL << 31) - 1);

  if (is_normed_time (t))
    snprintf (buf, buflen, "%u", t_red);
  else
    snprintf (buf, buflen, "<%u>", t_red);

  return buf;
}

int
_ping_setbuf (PING * p, bool use_ipv6)
{
  if (!p->ping_buffer)
    {
      p->ping_buffer = malloc (_PING_BUFLEN (p, use_ipv6));
      if (!p->ping_buffer)
	return -1;
    }
  if (!p->ping_cktab)
    {
      p->ping_cktab = malloc (p->ping_cktab_size);
      if (!p->ping_cktab)
	return -1;
      memset (p->ping_cktab, 0, p->ping_cktab_size);
    }
  return 0;
}

int
ping_set_data (PING * p, void *data, size_t off, size_t len, bool use_ipv6)
{
  icmphdr_t *icmp;

  if (_ping_setbuf (p, use_ipv6))
    return -1;
  if (p->ping_datalen < off + len)
    return -1;

  icmp = (icmphdr_t *) p->ping_buffer;
  memcpy (icmp->icmp_data + off, data, len);

  return 0;
}

void
ping_set_count (PING * ping, size_t count)
{
  ping->ping_count = count;
}

void
ping_set_sockopt (PING * ping, int opt, void *val, int valsize)
{
  setsockopt (ping->ping_fd, SOL_SOCKET, opt, (char *) &val, valsize);
}

void
ping_set_interval (PING * ping, size_t interval)
{
  ping->ping_interval = interval;
}

void
_ping_freebuf (PING * p)
{
  if (p->ping_buffer)
    {
      free (p->ping_buffer);
      p->ping_buffer = NULL;
    }
  if (p->ping_cktab)
    {
      free (p->ping_cktab);
      p->ping_cktab = NULL;
    }
}

void
ping_unset_data (PING * p)
{
  _ping_freebuf (p);
}

int
ping_timeout_p (struct timeval *start_time, int timeout)
{
  struct timeval now;
  gettimeofday (&now, NULL);
  if (timeout != -1)
    {
      tvsub (&now, start_time);
      if (now.tv_sec >= timeout)
        return 1;
    }
  return 0;
}

char *
ipaddr2str (struct sockaddr *from, socklen_t fromlen)
{
  int err;
  size_t len;
  char *buf, ipstr[INET6_ADDRSTRLEN], hoststr[256];

  err = getnameinfo (from, fromlen, ipstr, sizeof (ipstr),
		     NULL, 0, NI_NUMERICHOST);
  if (err)
    {
      const char *errmsg;

      if (err == EAI_SYSTEM)
	errmsg = strerror (errno);
      else
	errmsg = gai_strerror (err);

      fprintf (stderr, "ping: getnameinfo: %s\n", errmsg);
      return xstrdup ("unknown");
    }

  if (options & OPT_NUMERIC)
    return xstrdup (ipstr);

  err = getnameinfo (from, fromlen, hoststr, sizeof (hoststr),
		     NULL, 0,
#ifdef NI_IDN
		     NI_IDN | NI_NAMEREQD
#else
		     NI_NAMEREQD
#endif
		     );
  if (err)
    return xstrdup (ipstr);

  len = strlen (ipstr) + strlen (hoststr) + 4;	/* Pair of parentheses, a space
						   and a NUL. */
  buf = xmalloc (len);
  snprintf (buf, len, "%s (%s)", hoststr, ipstr);

  return buf;
}

char *
sinaddr2str (struct in_addr ina)
{
  struct hostent *hp;

  if (options & OPT_NUMERIC)
    return xstrdup (inet_ntoa (ina));

  hp = gethostbyaddr ((char *) &ina, sizeof (ina), AF_INET);
  if (hp == NULL)
    return xstrdup (inet_ntoa (ina));
  else
    {
      char *buf, *ipstr;
      int len;

      ipstr = inet_ntoa (ina);
      len = strlen (ipstr) + 1;

      if (hp->h_name)
	len += strlen (hp->h_name) + 4;	/* parentheses, space, and NUL */

      buf = xmalloc (len);
      if (hp->h_name)
	snprintf (buf, len, "%s (%s)", hp->h_name, ipstr);
      else
	snprintf (buf, len, "%s", ipstr);
      return buf;
    }
}
