inet.c

ucsb大学开发的aodv路由协议代码。

/*
 * Copyright (C) 2001, University of California, Santa Barbara
 * 
 * This program 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
 * of the License, or (at your option) any later version.
 * 
 * This program 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 * 
 * Other copyrights might apply to parts of this software and are so
 * noted when applicable.
 */

/*
 * Parts of this program has been derived from PIM sparse-mode pimd.
 * The pimd program is covered by the license in the accompanying file
 * named "LICENSE.pimd".
 *  
 * The pimd program is COPYRIGHT 1998 by University of Southern California.
 *
 */
#include <arpa/inet.h>
#include <net/if.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <unistd.h>

#include "aodvSocket.h"
#include "const.h"
#include "debug.h"

#define MAXHOSTNAMELEN 100

#define C(x)    ((x) & 0xff)

char *inet_fmt_h(u_int32_t addr, char *s);
char *inet_fmt_n(u_int32_t addr, char *s);

u_int32_t my_ip = -1;

u_int32_t getip() {
  struct ifreq if_info;
  struct sockaddr addr;
  struct sockaddr_in *addr_in;
  static char str[128];
  if((my_ip == -1) && (aodv_socket >= 0)){
    //initialize my_ip
    strncpy((char *)&if_info.ifr_name
	    ,(const char *)&interface
	    ,sizeof(if_info.ifr_name));
    if(ioctl(aodv_socket,SIOCGIFADDR,&if_info) == 0){
      addr=if_info.ifr_addr;
      addr_in=(struct sockaddr_in *)&addr;
      if(inet_ntop(AF_INET
		   ,&addr_in->sin_addr.s_addr
		   ,str,sizeof(str)) 
	 != NULL){
	my_ip=inet_addr(str);
      }
    }
    trace(TRACE_INIT,"getip:initializing my_ip to %s",inet_fmt_n(my_ip,s1));
  }
  return my_ip;
}


/*
 * Verify that a given netmask is plausible;
 * make sure that it is a series of 1's followed by
 * a series of 0's with no discontiguous 1's.
 */
int inet_valid_mask(u_int32_t mask) {
  if (~(((mask & -mask) - 1) | mask) != 0) {
    /* Mask is not contiguous */
    return (FALSE);
  }

  return (TRUE);
}



/*
 * Convert an IP address in u_int32_t (host) format into a printable string.
 */
char *inet_fmt_h(u_int32_t addr, char *s) {
  register u_char *a;
    
  a = (u_char *)&addr;
  sprintf(s, "%u.%u.%u.%u",a[3], a[2], a[1], a[0] );
  return (s);
}
/*
 * Convert an IP address in u_int32_t (network) format into a printable string.
 */
char *inet_fmt_n(u_int32_t addr, char *s) {
  register u_char *a;
    
  a = (u_char *)&addr;
  sprintf(s, "%u.%u.%u.%u", a[0], a[1], a[2], a[3]);
  return (s);
}


/*
 * Convert an IP subnet number in u_int32_t (network) format into a printable
 * string including the netmask as a number of bits.
 */
#ifdef NOSUCHDEF	/* replaced by netname() */
char *inet_fmts(u_int32_t addr,u_int32_t mask,char *s){
  register u_char *a, *m;
  int bits;

  if ((addr == 0) && (mask == 0)) {
    sprintf(s, "default");
    return (s);
  }
  a = (u_char *)&addr;
  m = (u_char *)&mask;
  bits = 33 - ffs(ntohl(mask));

  if      (m[3] != 0) sprintf(s, "%u.%u.%u.%u/%d", a[0], a[1], a[2], a[3],
			      bits);
  else if (m[2] != 0) sprintf(s, "%u.%u.%u/%d",    a[0], a[1], a[2], bits);
  else if (m[1] != 0) sprintf(s, "%u.%u/%d",       a[0], a[1], bits);
  else                sprintf(s, "%u/%d",          a[0], bits);
    
  return (s);
}

#endif /* NOSUCHDEF */

/*
 * Convert the printable string representation of an IP address into the
 * u_int32_t (network) format.  Return 0xffffffff on error.  (To detect the
 * legal address with that value, you must explicitly compare the string
 * with "255.255.255.255".)
 * The return value is in network order.
 */
u_int32_t inet_parse(char *s,int n){
  u_int32_t a = 0;
  u_int a0 = 0, a1 = 0, a2 = 0, a3 = 0;
  int i;
  char c;

  i = sscanf(s, "%u.%u.%u.%u%c", &a0, &a1, &a2, &a3, &c);
  if (i < n || i > 4 || a0 > 255 || a1 > 255 || a2 > 255 || a3 > 255)
    return (0xffffffff);

  ((u_char *)&a)[0] = a0;
  ((u_char *)&a)[1] = a1;
  ((u_char *)&a)[2] = a2;
  ((u_char *)&a)[3] = a3;

  return (a);
}


/*
 * inet_cksum extracted from:
 *			P I N G . C
 *
 * Author -
 *	Mike Muuss
 *	U. S. Army Ballistic Research Laboratory
 *	December, 1983
 * Modified at Uc Berkeley
 *
 * (ping.c) Status -
 *	Public Domain.  Distribution Unlimited.
 *
 *			I N _ C K S U M
 *
 * Checksum routine for Internet Protocol family headers (C Version)
 *
 */
int
inet_cksum(u_int16_t *addr,u_int len){
  register int nleft = (int)len;
  register u_int16_t *w = addr;
  u_int16_t answer = 0;
  register int sum = 0;

  /*
   *  Our algorithm is simple, using a 32 bit accumulator (sum),
   *  we add sequential 16 bit words to it, and at the end, fold
   *  back all the carry bits from the top 16 bits into the lower
   *  16 bits.
   */
  while (nleft > 1)  {
    sum += *w++;
    nleft -= 2;
  }

  /* mop up an odd byte, if necessary */
  if (nleft == 1) {
    *(u_char *) (&answer) = *(u_char *)w ;
    sum += answer;
  }

  /*
   * add back carry outs from top 16 bits to low 16 bits
   */
  sum = (sum >> 16) + (sum & 0xffff);	/* add hi 16 to low 16 */
  sum += (sum >> 16);			/* add carry */
  answer = ~sum;				/* truncate to 16 bits */
  return (answer);
}

/*
 * Called by following netname() to create a mask specified network address.
 */
void trimdomain(char *cp){
  static char domain[MAXHOSTNAMELEN + 1];
  static int first = 1;
  char *s;
    
  if (first) {
    first = 0;
    if (gethostname(domain, MAXHOSTNAMELEN) == 0 &&
	(s = (char *)strchr(domain, '.')))
      (void) strcpy(domain, s + 1);
    else
      domain[0] = 0;
  }

  if (domain[0]) {
    while ((cp = (char *)strchr(cp, '.'))) {
      if (!strcasecmp(cp + 1, domain)) {
	*cp = 0;        /* hit it */
	break;
      } else {
	cp++;
      }
    }
  }
}