/*
  Copyright (C) 2005-2023 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 <attribute.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;
    }
}
