ping_echo.c

linux下常用的网络工具的代码

/* Copyright (C) 2001, 2002, 2004 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 2, 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 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 GNU Inetutils; see the file COPYING.  If not, write
   to the Free Software Foundation, Inc., 51 Franklin Street,
   Fifth Floor, Boston, MA 02110-1301 USA. */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/file.h>
#include <sys/time.h>
#include <signal.h>

#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
/*#include <netinet/ip_icmp.h>  -- deliberately not including this */
#ifdef HAVE_NETINET_IP_VAR_H
# include <netinet/ip_var.h>
#endif

#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>

#include <icmp.h>
#include <ping.h>
#include "ping_common.h"
#include "ping_impl.h"

#define	NROUTES		9		/* number of record route slots */
#ifndef MAX_IPOPTLEN
# define MAX_IPOPTLEN 40
#endif

#include <xalloc.h>

static int handler (int code, void *closure,
		   struct sockaddr_in *dest, struct sockaddr_in *from,
		   struct ip *ip, icmphdr_t *icmp, int datalen);
int print_echo (int dup, struct ping_stat *stat,
	      struct sockaddr_in *dest, struct sockaddr_in *from,
	      struct ip *ip, icmphdr_t *icmp, int datalen);
static int echo_finish (void);

void print_icmp_header (struct sockaddr_in *from,
			      struct ip *ip, icmphdr_t *icmp, int len);
static void print_ip_opt (struct ip *ip, int hlen);

int
ping_echo (int argc, char **argv)
{
#ifdef IP_OPTIONS
  char rspace[3 + 4 * NROUTES + 1];	/* record route space */
#endif
  struct ping_stat ping_stat;

  if (options & OPT_FLOOD && options & OPT_INTERVAL)
    {
      fprintf (stderr,
	      "ping: -f and -i incompatible options.\n");
      return 2;
    }

  memset (&ping_stat, 0, sizeof (ping_stat));
  ping_stat.tmin = 999999999.0;

  ping_set_type (ping, ICMP_ECHO);
  ping_set_packetsize (ping, data_length);
  ping_set_event_handler (ping, handler, &ping_stat);

  if (ping_set_dest (ping, *argv))
    {
      fprintf (stderr, "ping: unknown host\n");
      exit (1);
    }

  if (options & OPT_RROUTE)
    {
#ifdef IP_OPTIONS
      memset (rspace, 0, sizeof (rspace));
      rspace[IPOPT_OPTVAL] = IPOPT_RR;
      rspace[IPOPT_OLEN] = sizeof (rspace)-1;
      rspace[IPOPT_OFFSET] = IPOPT_MINOFF;
      if (setsockopt (ping->ping_fd, IPPROTO_IP,
		     IP_OPTIONS, rspace, sizeof (rspace)) < 0)
	{
	  perror ("ping: record route");
	  exit (2);
	}
#else
      fprintf (stderr,
	      "ping: record route not available in this implementation.\n");
      exit (2);
#endif /* IP_OPTIONS */
    }

  printf ("PING %s (%s): %d data bytes\n",
	 ping->ping_hostname,
	 inet_ntoa (ping->ping_dest.sin_addr),
	 data_length);

  return ping_run (ping, echo_finish);
}

int
handler (int code, void *closure,
	struct sockaddr_in *dest, struct sockaddr_in *from,
	struct ip *ip, icmphdr_t *icmp, int datalen)
{
  switch (code)
    {
    case PEV_RESPONSE:
    case PEV_DUPLICATE:
      print_echo (code == PEV_DUPLICATE,
		   (struct ping_stat*)closure, dest, from, ip, icmp, datalen);
      break;
    case PEV_NOECHO:;
      print_icmp_header (from, ip, icmp, datalen);
    }
  return 0;
}

int
print_echo (int dupflag, struct ping_stat *ping_stat,
	   struct sockaddr_in *dest, struct sockaddr_in *from,
	   struct ip *ip, icmphdr_t *icmp, int datalen)
{
  int hlen;
  struct timeval tv;
  int timing = 0;
  double triptime = 0.0;

  gettimeofday (&tv, NULL);

  /* Length of IP header */
  hlen = ip->ip_hl << 2;

  /* Length of ICMP header+payload */
  datalen -= hlen;

  /* Do timing */
  if (PING_TIMING (datalen-8))
    {
      struct timeval tv1, *tp;

      timing++;
      tp = (struct timeval *) icmp->icmp_data;

      /* Avoid unaligned data: */
      memcpy (&tv1, tp, sizeof (tv1));
      tvsub (&tv, &tv1);

      triptime = ((double)tv.tv_sec) * 1000.0 +
	          ((double)tv.tv_usec) / 1000.0;
      ping_stat->tsum += triptime;
      ping_stat->tsumsq += triptime*triptime;
      if (triptime < ping_stat->tmin)
	ping_stat->tmin = triptime;
      if (triptime > ping_stat->tmax)
	ping_stat->tmax = triptime;
    }

  if (options & OPT_QUIET)
    return 0;
  if (options & OPT_FLOOD)
    {
      putchar ('\b');
      return 0;
    }

  printf ("%d bytes from %s: icmp_seq=%u", datalen,
	 inet_ntoa (*(struct in_addr *)&from->sin_addr.s_addr),
	 icmp->icmp_seq);
  printf (" ttl=%d", ip->ip_ttl);
  if (timing)
    printf (" time=%.3f ms", triptime);
  if (dupflag)
    printf (" (DUP!)");

  print_ip_opt (ip, hlen);
  printf ("\n");

  return 0;
}

char *
ipaddr2str (struct in_addr ina)
{
  struct hostent *hp;

  if (options & OPT_NUMERIC
      || !(hp = gethostbyaddr ((char *)&ina, 4, AF_INET)))
    return xstrdup (inet_ntoa (ina));
  else
    {
      char *ipstr = inet_ntoa (ina);
      int len = strlen (hp->h_name) + 1;
      char *buf;
      
      if (ipstr)
	len += strlen (ipstr) + 3; /* a pair of parentheses and a space */

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

#define NITEMS(a) sizeof(a)/sizeof((a)[0])

struct icmp_diag {
  int type;
  char *text;
  void (*fun) (icmphdr_t *, void *data);
  void *data;
};

struct icmp_code_descr {
  int code;
  char *diag;
} icmp_code_descr[] = {
  { ICMP_NET_UNREACH,    "Destination Net Unreachable" },
  { ICMP_HOST_UNREACH,   "Destination Host Unreachable" },
  { ICMP_PROT_UNREACH,   "Destination Protocol Unreachable" },
  { ICMP_PORT_UNREACH,   "Destination Port Unreachable" },
  { ICMP_FRAG_NEEDED,    "Fragmentation needed and DF set" },
  { ICMP_SR_FAILED,      "Source Route Failed" },
  { ICMP_NET_UNKNOWN,    "Network Unknown" },
  { ICMP_HOST_UNKNOWN,   "Host Unknown" },
  { ICMP_HOST_ISOLATED,  "Host Isolated" },
  { ICMP_NET_UNR_TOS,    "Destination Network Unreachable At This TOS" },
  { ICMP_HOST_UNR_TOS,   "Destination Host Unreachable At This TOS" },
#ifdef ICMP_PKT_FILTERED
  { ICMP_PKT_FILTERED,   "Packet Filtered" },
#endif
#ifdef ICMP_PREC_VIOLATION
  { ICMP_PREC_VIOLATION, "Precedence Violation" },
#endif
#ifdef ICMP_PREC_CUTOFF
  { ICMP_PREC_CUTOFF,    "Precedence Cutoff" },
#endif

  { ICMP_REDIR_NET,      "Redirect Network" },
  { ICMP_REDIR_HOST,     "Redirect Host" },
  { ICMP_REDIR_NETTOS,   "Redirect Type of Service and Network" },
  { ICMP_REDIR_HOSTTOS,  "Redirect Type of Service and Host" },

  { ICMP_EXC_TTL,        "Time to live exceeded" },
  { ICMP_EXC_FRAGTIME,   "Frag reassembly time exceeded" },
};

static void
print_icmp_code (int code, char *prefix)
{
  struct icmp_code_descr *p;

  for (p = icmp_code_descr; p < icmp_code_descr + NITEMS(icmp_code_descr); p++)
    if (p->code == code)
      {
	printf ("%s\n", p->diag);
	return;
      }
  
  printf ("%s, Unknown Code: %d\n", prefix, code);
}

static void
print_ip_header (struct ip *ip)
{
  int hlen;
  u_char *cp;

  hlen = ip->ip_hl << 2;
  cp = (u_char *)ip + 20;		/* point to options */

  printf ("Vr HL TOS  Len   ID Flg  off TTL Pro  cks      Src      Dst Data\n");
  printf (" %1x  %1x  %02x %04x %04x",
	 ip->ip_v, ip->ip_hl, ip->ip_tos, ip->ip_len, ip->ip_id);
  printf ("   %1x %04x", ((ip->ip_off) & 0xe000) >> 13,
	 (ip->ip_off) & 0x1fff);
  printf ("  %02x  %02x %04x", ip->ip_ttl, ip->ip_p, ip->ip_sum);
  printf (" %s ", inet_ntoa (*((struct in_addr *) &ip->ip_src)));
  printf (" %s ", inet_ntoa (*((struct in_addr *) &ip->ip_dst)));
  while (hlen-- > 20) 
    printf ("%02x", *cp++);

  printf ("\n");
}

void
print_ip_data (icmphdr_t *icmp, void *data)
{
  int hlen;
  u_char *cp;
  struct ip *ip = &icmp->icmp_ip;
  
  print_ip_header (ip);

  hlen = ip->ip_hl << 2;
  cp = (u_char *)ip + hlen;

  if (ip->ip_p == 6)
    printf ("TCP: from port %u, to port %u (decimal)\n",
	   (*cp * 256 + *(cp + 1)), (*(cp + 2) * 256 + *(cp + 3)));
  else if (ip->ip_p == 17)
    printf ("UDP: from port %u, to port %u (decimal)\n",
	   (*cp * 256 + *(cp + 1)), (*(cp + 2) * 256 + *(cp + 3)));

}

static void
print_icmp (icmphdr_t *icmp, void *data)
{
  print_icmp_code (icmp->icmp_code, data);
  print_ip_data (icmp, NULL);
}

static void
print_parameterprob (icmphdr_t *icmp, void *data)
{
  printf ("Parameter problem: IP address = %s\n",
	  inet_ntoa (icmp->icmp_gwaddr));
  print_ip_data (icmp, data);
}

struct icmp_diag icmp_diag[] = {
  { ICMP_ECHOREPLY, "Echo Reply", NULL },
  { ICMP_DEST_UNREACH, NULL, print_icmp, "Dest Unreachable" },
  { ICMP_SOURCE_QUENCH, "Source Quench", print_ip_data },
  { ICMP_REDIRECT, NULL, print_icmp, "Redirect" },
  { ICMP_ECHO, "Echo Request", NULL },
  { ICMP_TIME_EXCEEDED, NULL, print_icmp, "Time exceeded" },
  { ICMP_PARAMETERPROB, NULL, print_parameterprob },
  { ICMP_TIMESTAMP, "Timestamp", NULL },
  { ICMP_TIMESTAMPREPLY, "Timestamp Reply", NULL },
  { ICMP_INFO_REQUEST, "Information Request", NULL },
#ifdef ICMP_MASKREQ
  { ICMP_MASKREPLY, "Address Mask Reply", NULL },
#endif
};

void
print_icmp_header (struct sockaddr_in *from,
		   struct ip *ip, icmphdr_t *icmp, int len)
{
  int hlen;
  struct ip *orig_ip;
  char *s;
  struct icmp_diag *p;
  
  /* Length of the IP header */
  hlen = ip->ip_hl << 2;
  /* Original IP header */
  orig_ip = &icmp->icmp_ip;

  if (!(options & OPT_VERBOSE
	|| orig_ip->ip_dst.s_addr == ping->ping_dest.sin_addr.s_addr))
    return;

  printf ("%d bytes from %s: ", len-hlen, s = ipaddr2str (from->sin_addr));
  free (s);

  for (p = icmp_diag; p < icmp_diag + NITEMS(icmp_diag); p++)
    {
      if (p->type == icmp->icmp_type)
	{
	  if (p->text)
	    printf ("%s\n", p->text);
	  if (p->fun)
	    p->fun (icmp, p->data);
	  return;
	}
    }
  printf ("Bad ICMP type: %d\n", icmp->icmp_type);
}

void
print_ip_opt (struct ip *ip, int hlen)
{
  u_char *cp;
  int i, j, l;
  static int old_rrlen;
  static char old_rr[MAX_IPOPTLEN];

  cp = (u_char *)(ip + 1);

  for (; hlen > (int)sizeof (struct ip); --hlen, ++cp)
    switch (*cp)
      {
      case IPOPT_EOL:
	hlen = 0;
	break;
	
      case IPOPT_LSRR:
	printf ("\nLSRR: ");
	hlen -= 2;
	j = *++cp;
	++cp;
	if (j > IPOPT_MINOFF)
	  for (;;)
	    {
	      l = *++cp;
	      l = (l<<8) + *++cp;
	      l = (l<<8) + *++cp;
	      l = (l<<8) + *++cp;
	      if (l == 0)
		{
		  printf ("\t0.0.0.0");
		}
	      else
		{
		  struct in_addr ina;
		  char *s;
		  
		  ina.s_addr = ntohl (l);
		  printf ("\t%s", s = ipaddr2str (ina));
		  free (s);
		}
	      hlen -= 4;
	      j -= 4;
	      if (j <= IPOPT_MINOFF)
		break;
	      putchar ('\n');
	    }
	break;
	
      case IPOPT_RR:
	j = *++cp;	      
	i = *++cp;		
	hlen -= 2;
	if (i > j)
	  i = j;
	i -= IPOPT_MINOFF;
	if (i <= 0)
	  continue;
	if (i == old_rrlen
	    && cp == (u_char *)(ip + 1) + 2
	    && !memcmp ((char *)cp, old_rr, i)
	    && !(options & OPT_FLOOD))
	  {
	    printf ("\t (same route)");
	    i = ((i + 3) / 4) * 4;
	    hlen -= i;
	    cp += i;
	    break;
	  }
	if (i < MAX_IPOPTLEN)
	  {
	    old_rrlen = i;
	    memmove (old_rr, cp, i);
	  }
	else
	  old_rrlen = 0;

	printf ("\nRR: ");
	j = 0;
	for (;;)
	  {
	    l = *++cp;
	    l = (l<<8) + *++cp;
	    l = (l<<8) + *++cp;
	    l = (l<<8) + *++cp;
	    if (l == 0)
	      {
		printf ("\t0.0.0.0");
	      }
	    else
	      {
		struct in_addr ina;
		char *s;
		  
		ina.s_addr = ntohl (l);
		printf ("\t%s", s = ipaddr2str (ina));
		free (s);
	      }
	    hlen -= 4;
	    i -= 4;
	    j += 4;
	    if (i <= 0)
	      break;
	    if (j >= MAX_IPOPTLEN)
	      {
		printf ("\t (truncated route)");
		break;
	      }
	    putchar ('\n');
	  }
	break;
	
      case IPOPT_NOP:
	printf ("\nNOP");
	break;
	
      default:
	printf ("\nunknown option %x", *cp);
	break;
      }
}

int
echo_finish ()
{
  ping_finish ();
  if (ping->ping_num_recv && PING_TIMING (data_length))
    {
      struct ping_stat *ping_stat = (struct ping_stat*)ping->ping_closure;
      double total = ping->ping_num_recv + ping->ping_num_rept;
      double avg = ping_stat->tsum/total;
      double vari = ping_stat->tsumsq / total - avg * avg;

      printf ("round-trip min/avg/max/stddev = %.3f/%.3f/%.3f/%.3f ms\n",
	      ping_stat->tmin,
	      avg,
	      ping_stat->tmax,
	      nsqrt (vari, 0.0005));
    }
  exit (ping->ping_num_recv == 0);
}