rip_interface.c

大名鼎鼎的路由器源码。程序分ZEBRA、OSPFRIP等3个包。程序框架采用一个路由协议一个进程的方式

/* Interface related function for RIP.
 * Copyright (C) 1997, 98 Kunihiro Ishiguro <[e-mail]>
 *
 * This file is part of GNU Zebra.
 *
 * GNU Zebra 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 Zebra 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 GNU Zebra; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.  
 */

#include <zebra.h>

#include "command.h"
#include "if.h"
#include "sockunion.h"
#include "prefix.h"
#include "memory.h"
#include "network.h"
#include "table.h"
#include "log.h"
#include "stream.h"
#include "thread.h"
#include "zclient.h"
#include "filter.h"
#include "sockopt.h"

#include "zebra/connected.h"

#include "ripd/ripd.h"
#include "ripd/rip_debug.h"

void rip_enable_apply (struct interface *);
void rip_passive_interface_apply (struct interface *);
int rip_if_down(struct interface *ifp);

struct message ri_version_msg[] = 
{
  {RI_RIP_VERSION_1,       "1"},
  {RI_RIP_VERSION_2,       "2"},
  {RI_RIP_VERSION_1_AND_2, "1 2"},
  {0,                      NULL}
};

/* RIP enabled network vector. */
vector rip_enable_interface;

/* RIP enabled interface table. */
struct route_table *rip_enable_network;

/* Vector to store passive-interface name. */
vector Vrip_passive_interface;

/* Join to the RIP version 2 multicast group. */
int
ipv4_multicast_join (int sock, 
		     struct in_addr group, 
		     struct in_addr ifa,
		     unsigned int ifindex)
{
  int ret;

  ret = setsockopt_multicast_ipv4 (sock, 
				   IP_ADD_MEMBERSHIP, 
				   ifa, 
				   group.s_addr, 
				   ifindex); 

  if (ret < 0) 
    zlog (NULL, LOG_INFO, "can't setsockopt IP_ADD_MEMBERSHIP %s",
	  strerror (errno));

  return ret;
}

/* Leave from the RIP version 2 multicast group. */
int
ipv4_multicast_leave (int sock, 
		      struct in_addr group, 
		      struct in_addr ifa,
		      unsigned int ifindex)
{
  int ret;

  ret = setsockopt_multicast_ipv4 (sock, 
				   IP_DROP_MEMBERSHIP, 
				   ifa, 
				   group.s_addr, 
				   ifindex);

  if (ret < 0) 
    zlog (NULL, LOG_INFO, "can't setsockopt IP_DROP_MEMBERSHIP");

  return ret;
}

/* Allocate new RIP's interface configuration. */
struct rip_interface *
rip_interface_new ()
{
  struct rip_interface *ri;

  ri = XMALLOC (MTYPE_RIP_INTERFACE, sizeof (struct rip_interface));
  memset (ri, 0, sizeof (struct rip_interface));

  /* Default authentication type is simple password for Cisco
     compatibility. */
  /* ri->auth_type = RIP_NO_AUTH; */
  ri->auth_type = RIP_AUTH_SIMPLE_PASSWORD;

  /* Set default split-horizon behavior.  If the interface is Frame
     Relay or SMDS is enabled, the default value for split-horizon is
     off.  But currently Zebra does detect Frame Relay or SMDS
     interface.  So all interface is set to split horizon.  */
  ri->split_horizon_default = 1;
  ri->split_horizon = ri->split_horizon_default;

  return ri;
}

void
rip_interface_multicast_set (int sock, struct interface *ifp)
{
  int ret;
  listnode node;
  struct servent *sp;
  struct sockaddr_in from;

  for (node = listhead (ifp->connected); node; nextnode (node))
    {
      struct prefix_ipv4 *p;
      struct connected *connected;
      struct in_addr addr;

      connected = getdata (node);
      p = (struct prefix_ipv4 *) connected->address;

      if (p->family == AF_INET)
	{
	  addr = p->prefix;

	  if (setsockopt_multicast_ipv4 (sock, IP_MULTICAST_IF,
					 addr, 0, ifp->ifindex) < 0) 
	    {
	      zlog_warn ("Can't setsockopt IP_MULTICAST_IF to fd %d", sock);
	      return;
	    }

	  /* Bind myself. */
	  memset (&from, 0, sizeof (struct sockaddr_in));

	  /* Set RIP port. */
	  sp = getservbyname ("router", "udp");
	  if (sp) 
	    from.sin_port = sp->s_port;
	  else 
	    from.sin_port = htons (RIP_PORT_DEFAULT);

	  /* Address shoud be any address. */
	  from.sin_family = AF_INET;
	  from.sin_addr = addr;
#ifdef HAVE_SIN_LEN
	  from.sin_len = sizeof (struct sockaddr_in);
#endif /* HAVE_SIN_LEN */

	  ret = bind (sock, (struct sockaddr *) & from, 
		      sizeof (struct sockaddr_in));
	  if (ret < 0)
	    {
	      zlog_warn ("Can't bind socket: %s", strerror (errno));
	      return;
	    }

	  return;

	}
    }
}

/* Send RIP request packet to specified interface. */
void
rip_request_interface_send (struct interface *ifp, u_char version)
{
  struct sockaddr_in to;

  /* RIPv2 support multicast. */
  if (version == RIPv2 && if_is_multicast (ifp))
    {
      
      if (IS_RIP_DEBUG_EVENT)
	zlog_info ("multicast request on %s", ifp->name);

      rip_request_send (NULL, ifp, version);
      return;
    }

  /* RIPv1 and non multicast interface. */
  if (if_is_pointopoint (ifp) || if_is_broadcast (ifp))
    {
      listnode cnode;

      if (IS_RIP_DEBUG_EVENT)
	zlog_info ("broadcast request to %s", ifp->name);

      for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
	{
	  struct prefix_ipv4 *p;
	  struct connected *connected;

	  connected = getdata (cnode);
	  p = (struct prefix_ipv4 *) connected->destination;

	  if (p->family == AF_INET)
	    {
	      memset (&to, 0, sizeof (struct sockaddr_in));
	      to.sin_port = htons (RIP_PORT_DEFAULT);
	      to.sin_addr = p->prefix;

#if 0
	      if (IS_RIP_DEBUG_EVENT)
		zlog_info ("SEND request to %s", inet_ntoa (to.sin_addr));
#endif /* 0 */
	      
	      rip_request_send (&to, ifp, version);
	    }
	}
    }
}

/* This will be executed when interface goes up. */
void
rip_request_interface (struct interface *ifp)
{
  struct rip_interface *ri;

  /* In default ripd doesn't send RIP_REQUEST to the loopback interface. */
  if (if_is_loopback (ifp))
    return;

  /* If interface is down, don't send RIP packet. */
  if (! if_is_up (ifp))
    return;

  /* Fetch RIP interface information. */
  ri = ifp->info;


  /* If there is no version configuration in the interface,
     use rip's version setting. */
  if (ri->ri_send == RI_RIP_UNSPEC)
    {
      if (rip->version == RIPv1)
	rip_request_interface_send (ifp, RIPv1);
      else
	rip_request_interface_send (ifp, RIPv2);
    }
  /* If interface has RIP version configuration use it. */
  else
    {
      if (ri->ri_send & RIPv1)
	rip_request_interface_send (ifp, RIPv1);
      if (ri->ri_send & RIPv2)
	rip_request_interface_send (ifp, RIPv2);
    }
}

/* Send RIP request to the neighbor. */
void
rip_request_neighbor (struct in_addr addr)
{
  struct sockaddr_in to;

  memset (&to, 0, sizeof (struct sockaddr_in));
  to.sin_port = htons (RIP_PORT_DEFAULT);
  to.sin_addr = addr;

  rip_request_send (&to, NULL, rip->version);
}

/* Request routes at all interfaces. */
void
rip_request_neighbor_all ()
{
  struct route_node *rp;

  if (! rip)
    return;

  if (IS_RIP_DEBUG_EVENT)
    zlog_info ("request to the all neighbor");

  /* Send request to all neighbor. */
  for (rp = route_top (rip->neighbor); rp; rp = route_next (rp))
    if (rp->info)
      rip_request_neighbor (rp->p.u.prefix4);
}

/* Multicast packet receive socket. */
int
rip_multicast_join (struct interface *ifp, int sock)
{
  listnode cnode;

  if (if_is_up (ifp) && if_is_multicast (ifp))
    {
      if (IS_RIP_DEBUG_EVENT)
	zlog_info ("multicast join at %s", ifp->name);

      for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
	{
	  struct prefix_ipv4 *p;
	  struct connected *connected;
	  struct in_addr group;
	      
	  connected = getdata (cnode);
	  p = (struct prefix_ipv4 *) connected->address;
      
	  if (p->family != AF_INET)
	    continue;
      
	  group.s_addr = htonl (INADDR_RIP_GROUP);
	  if (ipv4_multicast_join (sock, group, p->prefix, ifp->ifindex) < 0)
	    return -1;
	  else
	    return 0;
	}
    }
  return 0;
}

/* Leave from multicast group. */
void
rip_multicast_leave (struct interface *ifp, int sock)
{
  listnode cnode;

  if (if_is_up (ifp) && if_is_multicast (ifp))
    {
      if (IS_RIP_DEBUG_EVENT)
	zlog_info ("multicast leave from %s", ifp->name);

      for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
	{
	  struct prefix_ipv4 *p;
	  struct connected *connected;
	  struct in_addr group;
	      
	  connected = getdata (cnode);
	  p = (struct prefix_ipv4 *) connected->address;
      
	  if (p->family != AF_INET)
	    continue;
      
	  group.s_addr = htonl (INADDR_RIP_GROUP);
          if (ipv4_multicast_leave (sock, group, p->prefix, ifp->ifindex) == 0)
	    return;
        }
    }
}

/* Is there and address on interface that I could use ? */
int
rip_if_ipv4_address_check (struct interface *ifp)
{
  struct listnode *nn;
  struct connected *connected;
  int count = 0;

  for (nn = listhead (ifp->connected); nn; nextnode (nn))
    if ((connected = getdata (nn)) != NULL)
      {
	struct prefix *p;

	p = connected->address;

	if (p->family == AF_INET)
          {
	    count++;
	  }
      }
						
  return count;
}
						
						
						

/* Does this address belongs to me ? */
int
if_check_address (struct in_addr addr)
{
  listnode node;

  for (node = listhead (iflist); node; nextnode (node))
    {
      listnode cnode;
      struct interface *ifp;

      ifp = getdata (node);

      for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
	{
	  struct connected *connected;
	  struct prefix_ipv4 *p;

	  connected = getdata (cnode);
	  p = (struct prefix_ipv4 *) connected->address;

	  if (p->family != AF_INET)
	    continue;

	  if (IPV4_ADDR_CMP (&p->prefix, &addr) == 0)
	    return 1;
	}
    }
  return 0;
}

/* is this address from a valid neighbor? (RFC2453 - Sec. 3.9.2) */
int
if_valid_neighbor (struct in_addr addr)
{
  listnode node;
  struct connected *connected = NULL;
  struct prefix_ipv4 *p;

  for (node = listhead (iflist); node; nextnode (node))
    {
      listnode cnode;
      struct interface *ifp;

      ifp = getdata (node);

      for (cnode = listhead (ifp->connected); cnode; nextnode (cnode))
	{
	  struct prefix *pxn = NULL; /* Prefix of the neighbor */
	  struct prefix *pxc = NULL; /* Prefix of the connected network */

	  connected = getdata (cnode);

	  if (if_is_pointopoint (ifp))
	    {
	      p = (struct prefix_ipv4 *) connected->address;

	      if (p && p->family == AF_INET)
		{
		  if (IPV4_ADDR_SAME (&p->prefix, &addr))
		    return 1;

		  p = (struct prefix_ipv4 *) connected->destination;
		  if (p && IPV4_ADDR_SAME (&p->prefix, &addr))
		    return 1;
		}
	    }
	  else
	    {
	      p = (struct prefix_ipv4 *) connected->address;

	      if (p->family != AF_INET)
		continue;

	      pxn = prefix_new();
	      pxn->family = AF_INET;
	      pxn->prefixlen = 32;
	      pxn->u.prefix4 = addr;
	      
	      pxc = prefix_new();
	      prefix_copy(pxc, (struct prefix *) p);
	      apply_mask(pxc);
	  
	      if (prefix_match (pxc, pxn)) 
		{
		  prefix_free (pxn);
		  prefix_free (pxc);
		  return 1;
		}
	      prefix_free(pxc);
	      prefix_free(pxn);
	    }
	}
    }
  return 0;
}

/* Inteface link down message processing. */
int
rip_interface_down (int command, struct zclient *zclient, zebra_size_t length)
{
  struct interface *ifp;
  struct stream *s;

  s = zclient->ibuf;  

  /* zebra_interface_state_read() updates interface structure in
     iflist. */
  ifp = zebra_interface_state_read(s);

  if (ifp == NULL)
    return 0;

  rip_if_down(ifp);
 
  if (IS_RIP_DEBUG_ZEBRA)
    zlog_info ("interface %s index %d flags %ld metric %d mtu %d is down",
	       ifp->name, ifp->ifindex, ifp->flags, ifp->metric, ifp->mtu);

  return 0;
}

/* Inteface link up message processing */
int
rip_interface_up (int command, struct zclient *zclient, zebra_size_t length)
{
  struct interface *ifp;

  /* zebra_interface_state_read () updates interface structure in
     iflist. */
  ifp = zebra_interface_state_read (zclient->ibuf);

  if (ifp == NULL)
    return 0;

  if (IS_RIP_DEBUG_ZEBRA)
    zlog_info ("interface %s index %d flags %ld metric %d mtu %d is up",
	       ifp->name, ifp->ifindex, ifp->flags, ifp->metric, ifp->mtu);

  /* Check if this interface is RIP enabled or not.*/
  rip_enable_apply (ifp);
 
  /* Check for a passive interface */
  rip_passive_interface_apply (ifp);

  /* Apply distribute list to the all interface. */
  rip_distribute_update_interface (ifp);

  return 0;
}

/* Inteface addition message from zebra. */
int
rip_interface_add (int command, struct zclient *zclient, zebra_size_t length)
{
  struct interface *ifp;

  ifp = zebra_interface_add_read (zclient->ibuf);

  if (IS_RIP_DEBUG_ZEBRA)
    zlog_info ("interface add %s index %d flags %ld metric %d mtu %d",
	       ifp->name, ifp->ifindex, ifp->flags, ifp->metric, ifp->mtu);

  /* Check if this interface is RIP enabled or not.*/
  rip_enable_apply (ifp);

  /* Apply distribute list to the all interface. */
  rip_distribute_update_interface (ifp);

  /* rip_request_neighbor_all (); */

  return 0;
}

int
rip_interface_delete (int command, struct zclient *zclient,
		      zebra_size_t length)
{
  struct interface *ifp;
  struct stream *s;


  s = zclient->ibuf;  
  /* zebra_interface_state_read() updates interface structure in iflist */
  ifp = zebra_interface_state_read(s);

  if (ifp == NULL)
    return 0;

  if (if_is_up (ifp)) {
    rip_if_down(ifp);
  } 
  
  zlog_info("interface delete %s index %d flags %ld metric %d mtu %d",
	    ifp->name, ifp->ifindex, ifp->flags, ifp->metric, ifp->mtu);  
  
  /* To support pseudo interface do not free interface structure.  */
  /* if_delete(ifp); */

  return 0;
}

void
rip_interface_clean ()
{
  listnode node;
  struct interface *ifp;
  struct rip_interface *ri;

  for (node = listhead (iflist); node; nextnode (node))
    {
      ifp = getdata (node);
      ri = ifp->info;

      ri->enable_network = 0;
      ri->enable_interface = 0;
      ri->running = 0;

      if (ri->t_wakeup)
	{
	  thread_cancel (ri->t_wakeup);
	  ri->t_wakeup = NULL;
	}
    }
}

void
rip_interface_reset ()
{
  listnode node;
  struct interface *ifp;
  struct rip_interface *ri;

  for (node = listhead (iflist); node; nextnode (node))
    {
      ifp = getdata (node);
      ri = ifp->info;

      ri->enable_network = 0;
      ri->enable_interface = 0;
      ri->running = 0;

      ri->ri_send = RI_RIP_UNSPEC;
      ri->ri_receive = RI_RIP_UNSPEC;

      /* ri->auth_type = RIP_NO_AUTH; */
      ri->auth_type = RIP_AUTH_SIMPLE_PASSWORD;

      if (ri->auth_str)
	{
	  free (ri->auth_str);
	  ri->auth_str = NULL;
	}
      if (ri->key_chain)
	{
	  free (ri->key_chain);
	  ri->key_chain = NULL;
	}

      ri->split_horizon = 0;
      ri->split_horizon_default = 0;

      ri->list[RIP_FILTER_IN] = NULL;
      ri->list[RIP_FILTER_OUT] = NULL;

      ri->prefix[RIP_FILTER_IN] = NULL;
      ri->prefix[RIP_FILTER_OUT] = NULL;
      
      if (ri->t_wakeup)
	{
	  thread_cancel (ri->t_wakeup);