ifnet.c

wifi 无线网络路由协议OLSR linux下C代码

/*
 * The olsr.org Optimized Link-State Routing daemon(olsrd)
 * Copyright (c) 2004, Andreas T鴑nesen([e-mail])
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met:
 *
 * * Redistributions of source code must retain the above copyright 
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright 
 *   notice, this list of conditions and the following disclaimer in 
 *   the documentation and/or other materials provided with the 
 *   distribution.
 * * Neither the name of olsr.org, olsrd nor the names of its 
 *   contributors may be used to endorse or promote products derived 
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Visit http://www.olsr.org for more information.
 *
 * If you find this software useful feel free to make a donation
 * to the project. For more information see the website or contact
 * the copyright holders.
 *
 * $Id: ifnet.c,v 1.51 2007/08/23 21:20:02 bernd67 Exp $
 */


#if defined __FreeBSD__ || defined __MacOSX__ || defined __NetBSD__ || defined __OpenBSD__
#define ifr_netmask ifr_addr
#endif

#include "interfaces.h"
#include "ifnet.h"
#include "defs.h"
#include "olsr.h"
#include "net_os.h"
#include "net_olsr.h"
#include "socket_parser.h"
#include "parser.h"
#include "scheduler.h"
#include "generate_msg.h"
#include "mantissa.h"
#include "lq_packet.h"
#include "log.h"
#include "link_set.h"
#include <signal.h>
#include <sys/types.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>

int bufspace = 127*1024;	/* max. input buffer size to request */


int
set_flag(char *ifname, short flag __attribute__((unused)))
{
  struct ifreq ifr;

  strncpy(ifr.ifr_name, ifname, IFNAMSIZ);

  /* Get flags */
  if (ioctl(olsr_cnf->ioctl_s, SIOCGIFFLAGS, &ifr) < 0) 
    {
      fprintf(stderr,"ioctl (get interface flags)");
      return -1;
    }

  strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
  
  //printf("Setting flags for if \"%s\"\n", ifr.ifr_name);

  if(!(ifr.ifr_flags & (IFF_UP | IFF_RUNNING)))
    {
      /* Add UP */
      ifr.ifr_flags |= (IFF_UP | IFF_RUNNING);
      /* Set flags + UP */
      if(ioctl(olsr_cnf->ioctl_s, SIOCSIFFLAGS, &ifr) < 0)
	{
	  fprintf(stderr, "ERROR(%s): %s\n", ifr.ifr_name, strerror(errno));
	  return -1;
	}
    }
  return 1;

}




void
check_interface_updates(void *foo __attribute__((unused)))
{
  struct olsr_if *tmp_if;

#ifdef DEBUG
  OLSR_PRINTF(3, "Checking for updates in the interface set\n");
#endif

  for(tmp_if = olsr_cnf->interfaces; tmp_if != NULL; tmp_if = tmp_if->next)
    {
      if(tmp_if->host_emul)
	continue;
      
      if(olsr_cnf->host_emul) /* XXX: TEMPORARY! */
	continue;

      if(!tmp_if->cnf->autodetect_chg) 
        {
#ifdef DEBUG
          /* Don't check this interface */
          OLSR_PRINTF(3, "Not checking interface %s\n", tmp_if->name)
#endif
          continue;
        }

      if(tmp_if->configured)
        {
          chk_if_changed(tmp_if);
        }
      else
        {
          chk_if_up(tmp_if, 3);
        }
    }

  return;
}

/**
 * Checks if an initialized interface is changed
 * that is if it has been set down or the address
 * has been changed.
 *
 *@param iface the olsr_if struct describing the interface
 */
int
chk_if_changed(struct olsr_if *iface)
{
  struct interface *ifp, *tmp_ifp;
  struct ifreq ifr;
  struct sockaddr_in6 tmp_saddr6;
  int if_changes;
  if_changes = 0;

#ifdef DEBUG
  OLSR_PRINTF(3, "Checking if %s is set down or changed\n", iface->name);
#endif

  if(iface->host_emul)
    return -1;

  ifp = iface->interf;

  if(ifp == NULL)
    {
      /* Should not happen */
      iface->configured = 0;
      return 0;
    }

  memset(&ifr, 0, sizeof(struct ifreq));
  strncpy(ifr.ifr_name, iface->name, IFNAMSIZ);


  /* Get flags (and check if interface exists) */
  if (ioctl(olsr_cnf->ioctl_s, SIOCGIFFLAGS, &ifr) < 0) 
    {
      OLSR_PRINTF(3, "No such interface: %s\n", iface->name);
      goto remove_interface;
    }

  ifp->int_flags = ifr.ifr_flags;

  /*
   * First check if the interface is set DOWN
   */

  if ((ifp->int_flags & IFF_UP) == 0)
    {
      OLSR_PRINTF(1, "\tInterface %s not up - removing it...\n", iface->name);
      goto remove_interface;
    }

  /*
   * We do all the interface type checks over.
   * This is because the interface might be a PCMCIA card. Therefore
   * It might not be the same physical interface as we configured earlier.
   */

  /* Check broadcast */
  if ((olsr_cnf->ip_version == AF_INET) && 
      !iface->cnf->ipv4_broadcast.v4 && /* Skip if fixed bcast */ 
      (!(ifp->int_flags & IFF_BROADCAST))) 
    {
      OLSR_PRINTF(3, "\tNo broadcast - removing\n");
      goto remove_interface;
    }

  if (ifp->int_flags & IFF_LOOPBACK)
    {
      OLSR_PRINTF(3, "\tThis is a loopback interface - removing it...\n");
      goto remove_interface;
    }

  ifp->is_hcif = OLSR_FALSE;

  /* trying to detect if interface is wireless. */
  ifp->is_wireless = check_wireless_interface(ifr.ifr_name);

  /* Set interface metric */
  if(iface->cnf->weight.fixed)
    ifp->int_metric = iface->cnf->weight.value;
  else
    ifp->int_metric = calculate_if_metric(ifr.ifr_name);

  /* Get MTU */
  if (ioctl(olsr_cnf->ioctl_s, SIOCGIFMTU, &ifr) < 0)
    ifp->int_mtu = 0;
  else
    {
      ifr.ifr_mtu -= (olsr_cnf->ip_version == AF_INET6) ? UDP_IPV6_HDRSIZE : UDP_IPV4_HDRSIZE;

      if(ifp->int_mtu != ifr.ifr_mtu)
	{
	  ifp->int_mtu = ifr.ifr_mtu;
	  /* Create new outputbuffer */
	  net_remove_buffer(ifp); /* Remove old */
	  net_add_buffer(ifp);
	}
    }


  /* Get interface index */
  ifp->if_index = if_nametoindex(ifr.ifr_name);

  /*
   * Now check if the IP has changed
   */
  
  /* IP version 6 */
  if(olsr_cnf->ip_version == AF_INET6)
    {
      /* Get interface address */
      
      if(get_ipv6_address(ifr.ifr_name, &tmp_saddr6, iface->cnf->ipv6_addrtype) <= 0)
	{
	  if(iface->cnf->ipv6_addrtype == IPV6_ADDR_SITELOCAL)
	    OLSR_PRINTF(3, "\tCould not find site-local IPv6 address for %s\n", ifr.ifr_name);
	  else
	    OLSR_PRINTF(3, "\tCould not find global IPv6 address for %s\n", ifr.ifr_name);
	  
	  
	  goto remove_interface;
	}
      
#ifdef DEBUG
      OLSR_PRINTF(3, "\tAddress: %s\n", ip6_to_string(&tmp_saddr6.sin6_addr));
#endif

      if(memcmp(&tmp_saddr6.sin6_addr, &ifp->int6_addr.sin6_addr, olsr_cnf->ipsize) != 0)
	{
	  OLSR_PRINTF(1, "New IP address for %s:\n", ifr.ifr_name);
	  OLSR_PRINTF(1, "\tOld: %s\n", ip6_to_string(&ifp->int6_addr.sin6_addr));
	  OLSR_PRINTF(1, "\tNew: %s\n", ip6_to_string(&tmp_saddr6.sin6_addr));

	  /* Check main addr */
	  if(memcmp(&olsr_cnf->main_addr, &tmp_saddr6.sin6_addr, olsr_cnf->ipsize) == 0)
	    {
	      /* Update main addr */
	      memcpy(&olsr_cnf->main_addr, &tmp_saddr6.sin6_addr, olsr_cnf->ipsize);
	    }

	  /* Update address */
	  memcpy(&ifp->int6_addr.sin6_addr, &tmp_saddr6.sin6_addr, olsr_cnf->ipsize);
	  memcpy(&ifp->ip_addr, &tmp_saddr6.sin6_addr, olsr_cnf->ipsize);

	  run_ifchg_cbs(ifp, IFCHG_IF_UPDATE);

	  return 1;	  	  
	}
      return 0;

    }
  else
  /* IP version 4 */
    {
      /* Check interface address (IPv4)*/
      if(ioctl(olsr_cnf->ioctl_s, SIOCGIFADDR, &ifr) < 0) 
	{
	  OLSR_PRINTF(1, "\tCould not get address of interface - removing it\n");
	  goto remove_interface;
	}

#ifdef DEBUG
      OLSR_PRINTF(3, "\tAddress:%s\n", sockaddr_to_string(&ifr.ifr_addr));
#endif

      if(memcmp(&((struct sockaddr_in *)&ifp->int_addr)->sin_addr.s_addr,
		&((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr, 
		olsr_cnf->ipsize) != 0)
	{
	  /* New address */
	  OLSR_PRINTF(1, "IPv4 address changed for %s\n", ifr.ifr_name);
	  OLSR_PRINTF(1, "\tOld:%s\n", sockaddr_to_string(&ifp->int_addr));
	  OLSR_PRINTF(1, "\tNew:%s\n", sockaddr_to_string(&ifr.ifr_addr));

	  ifp->int_addr = ifr.ifr_addr;

	  if(memcmp(&olsr_cnf->main_addr, 
		    &ifp->ip_addr,
		    olsr_cnf->ipsize) == 0)
	    {
	      OLSR_PRINTF(1, "New main address: %s\n", sockaddr_to_string(&ifr.ifr_addr));
	      olsr_syslog(OLSR_LOG_INFO, "New main address: %s\n", sockaddr_to_string(&ifr.ifr_addr));
	      memcpy(&olsr_cnf->main_addr, 
		     &((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr, 
		     olsr_cnf->ipsize);
	    }

	  memcpy(&ifp->ip_addr, 
		 &((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr, 
		 olsr_cnf->ipsize);

	  if_changes = 1;
	}

      /* Check netmask */
      if (ioctl(olsr_cnf->ioctl_s, SIOCGIFNETMASK, &ifr) < 0) 
	{
	  olsr_syslog(OLSR_LOG_ERR, "%s: ioctl (get broadaddr)", ifr.ifr_name);
	  goto remove_interface;
	}

#ifdef DEBUG
      OLSR_PRINTF(3, "\tNetmask:%s\n", sockaddr_to_string(&ifr.ifr_netmask));
#endif

      if(memcmp(&((struct sockaddr_in *)&ifp->int_netmask)->sin_addr.s_addr,
		&((struct sockaddr_in *)&ifr.ifr_netmask)->sin_addr.s_addr, 
		olsr_cnf->ipsize) != 0)
	{
	  /* New address */