path: root/proto/rip/rip.c

/*
 *	Rest in pieces - RIP protocol
 *
 *	Copyright (c) 1998, 1999 Pavel Machek <pavel@ucw.cz>
 *
 *	Can be freely distributed and used under the terms of the GNU GPL.
 *
 	FIXME: IpV6 support: packet size
 	FIXME: IpV6 support: use right address for broadcasts
	FIXME: IpV6 support: receive "route using" blocks

	FIXME (nonurgent): fold rip_connection into rip_interface?

	We are not going to honour requests for sending part of
	routing table. That would need to turn split horizon off,
	etc.  

	Triggered updates. When triggered update was sent, don't send
	new one for something between 1 and 5 seconds (and send one
	after that), says RFC. We do something else: once in 5 second
	we look for any changed routes and broadcast them.

	FIXME: (nonurgent) allow bigger frequencies than 1 regular update in 6 seconds (?)
	FIXME: propagation of metric=infinity into main routing table may or may not be good idea.

 */

#define LOCAL_DEBUG

#include "nest/bird.h"
#include "nest/iface.h"
#include "nest/protocol.h"
#include "nest/route.h"
#include "lib/socket.h"
#include "lib/resource.h"
#include "lib/lists.h"
#include "lib/timer.h"
#include "lib/string.h"

#include "rip.h"

#define P ((struct rip_proto *) p)
#define P_CF ((struct rip_proto_config *)p->cf)
#define E ((struct rip_entry *) e)

#define TRACE(level, msg, args...) do { if (p->debug & level) { log(L_TRACE "%s: " msg, p->name , ## args); } } while(0)

static struct rip_interface *new_iface(struct proto *p, struct iface *new, unsigned long flags, struct iface_patt *patt);

#define P_NAME p->name

/*
 * Output processing
 */

static void
rip_tx_err( sock *s, int err )
{
  struct rip_connection *c = s->data;
  struct proto *p = c->proto;
  log( L_ERR "Unexpected error at rip transmit: %m" );
}

static void
rip_tx_prepare(struct proto *p, ip_addr daddr, struct rip_block *b, struct rip_entry *e, struct rip_interface *rif )
{
  DBG( "." );
  b->family  = htons( 2 ); /* AF_INET */
  b->tag     = htons( e->tag );
  b->network = e->n.prefix;
#ifndef IPV6
  b->netmask = ipa_mkmask( e->n.pxlen );
  ipa_hton( b->netmask );

  if (neigh_connected_to(p, &e->nexthop, rif->iface))
    b->nexthop = e->nexthop;
  else
    b->nexthop = IPA_NONE;
  ipa_hton( b->nexthop );
#else
  b->pxlen = e->n.pxlen;
#endif
  b->metric  = htonl( e->metric );
  if (neigh_connected_to(p, &e->whotoldme, rif->iface)) {
    DBG( "(split horizon)" );
    b->metric = htonl( P_CF->infinity );
  }
  ipa_hton( b->network );
}

static void
rip_tx( sock *s )
{
  struct rip_interface *rif = s->data;
  struct rip_connection *c = rif->busy;
  struct proto *p = c->proto;
  struct rip_packet *packet = (void *) s->tbuf;
  int i, packetlen;

  DBG( "Sending to %I\n", s->daddr );
  do {

    if (c->done)
      goto done;

    DBG( "Preparing packet to send: " );

    packet->heading.command = RIPCMD_RESPONSE;
    packet->heading.version = RIP_V2;
    packet->heading.unused  = 0;

    i = !!P_CF->authtype;
    FIB_ITERATE_START(&P->rtable, &c->iter, z) {
      struct rip_entry *e = (struct rip_entry *) z;

      if (!rif->triggered || (!(e->updated < now-5))) {

	rip_tx_prepare( p, s->daddr, packet->block + i, e, rif );
	if (i++ == ((P_CF->authtype == AT_MD5) ? PACKET_MD5_MAX : PACKET_MAX)) {
	  FIB_ITERATE_PUT(&c->iter, z);
	  goto break_loop;
	}
      }
    } FIB_ITERATE_END(z);
    c->done = 1;

  break_loop:

    packetlen = rip_outgoing_authentication(p, (void *) &packet->block[0], packet, i);

    DBG( ", sending %d blocks, ", i );
    if (i == !!P_CF->authtype) {
      DBG( "not sending NULL update\n" );
      c->done = 1;
      goto done;
    }
    if (ipa_nonzero(c->daddr))
      i = sk_send_to( s, packetlen, c->daddr, c->dport );
    else
      i = sk_send( s, packetlen );

    DBG( "it wants more\n" );
  
  } while (i>0);
  
  if (i<0) rip_tx_err( s, i );
  DBG( "blocked\n" );
  return;

done:
  DBG( "Looks like I'm" );
  c->rif->busy = NULL;
  rem_node(NODE c);
  mb_free(c);
  DBG( " done\n" );
  return;
}

static void
rip_sendto( struct proto *p, ip_addr daddr, int dport, struct rip_interface *rif )
{
  struct iface *iface = rif->iface;
  struct rip_connection *c;
  static int num = 0;

  if (rif->busy) {
    log (L_WARN "Interface %s is much too slow, dropping request", iface->name);
    return;
  }
  c = mb_alloc( p->pool, sizeof( struct rip_connection ));
  rif->busy = c;
  
  c->addr = daddr;
  c->proto = p;
  c->num = num++;
  c->rif = rif;

  c->dport = dport;
  c->daddr = daddr;
  if (c->rif->sock->data != rif)
    bug("not enough send magic");
#if 0
  if (sk_open(c->send)<0) {
    log( L_ERR "Could not open socket for data send to %I:%d on %s", daddr, dport, rif->iface->name );
    return;
  }
#endif

  c->done = 0;
  fit_init( &c->iter, &P->rtable );
  add_head( &P->connections, NODE c );
  TRACE(D_PACKETS, "Sending my routing table to %I:%d on %s\n", daddr, dport, rif->iface->name );

  rip_tx(c->rif->sock);
}

static struct rip_interface*
find_interface(struct proto *p, struct iface *what)
{
  struct rip_interface *i;

  WALK_LIST (i, P->interfaces)
    if (i->iface == what)
      return i;
  return NULL;
}

/*
 * Input processing
 */

/* Let main routing table know about our new entry */
static void
advertise_entry( struct proto *p, struct rip_block *b, ip_addr whotoldme )
{
  rta *a, A;
  rte *r;
  net *n;
  neighbor *neighbor;
  struct rip_interface *rif;
  int pxlen;

  bzero(&A, sizeof(A));
  A.proto = p;
  A.source = RTS_RIP;
  A.scope = SCOPE_UNIVERSE;
  A.cast = RTC_UNICAST;
  A.dest = RTD_ROUTER;
  A.flags = 0;
#ifndef IPV6
  A.gw = ipa_nonzero(b->nexthop) ? b->nexthop : whotoldme;
  pxlen = ipa_mklen(b->netmask);
#else
  A.gw = whotoldme; /* FIXME: next hop is in other packet for v6 */
  pxlen = b->pxlen;
#endif
  A.from = whotoldme;

  /* No need to look if destination looks valid - ie not net 0 or 127 -- core will do for us. */

  neighbor = neigh_find( p, &A.gw, 0 );
  if (!neighbor) {
    log( L_REMOTE "%I asked me to route %I/%d using not-neighbor %I.", A.from, b->network, pxlen, A.gw );
    return;
  }

  A.iface = neighbor->iface;
  if (!(rif = neighbor->data)) {
    rif = neighbor->data = find_interface(p, A.iface);
  }
  if (!rif) {
    bug("Route packet using unknown interface? No.");
    return;
  }
    
  /* set to: interface of nexthop */
  a = rta_lookup(&A);
  if (pxlen==-1)  {
    log( L_REMOTE "%I gave me invalid pxlen/netmask for %I.", A.from, b->network );
    return;
  }
  n = net_get( p->table, b->network, pxlen );
  r = rte_get_temp(a);
  r->u.rip.metric = ntohl(b->metric) + rif->patt->metric;
  if (r->u.rip.metric > P_CF->infinity) r->u.rip.metric = P_CF->infinity;
  r->u.rip.tag = ntohl(b->tag);
  r->net = n;
  r->pflags = 0; /* Here go my flags */
  rte_update( p->table, n, p, r );
  DBG( "done\n" );
}

static void
process_block( struct proto *p, struct rip_block *block, ip_addr whotoldme )
{
  int metric = ntohl( block->metric );
  ip_addr network = block->network;

  CHK_MAGIC;
  TRACE(D_ROUTES, "block: %I tells me: %I/??? available, metric %d... ", whotoldme, network, metric );
  if ((!metric) || (metric > P_CF->infinity)) {
    log( L_WARN "Got metric %d from %I", metric, whotoldme );
    return;
  }

  advertise_entry( p, block, whotoldme );
}

#define BAD( x ) { log( L_REMOTE "%s: " x, P_NAME ); return 1; }

static int
rip_process_packet( struct proto *p, struct rip_packet *packet, int num, ip_addr whotoldme, int port )
{
  int i;
  int native_class = 0, authenticated = 0;

  switch( packet->heading.version ) {
  case RIP_V1: DBG( "Rip1: " ); break;
  case RIP_V2: DBG( "Rip2: " ); break;
  default: BAD( "Unknown version" );
  }

  switch( packet->heading.command ) {
  case RIPCMD_REQUEST: DBG( "Asked to send my routing table\n" ); 
	  if (P_CF->honour == HO_NEVER) {
	    log( L_REMOTE "They asked me to send routing table, but I was told not to do it" );
	    return 0;
	  }
	  if ((P_CF->honour == HO_NEIGHBOUR) && (!neigh_find( p, &whotoldme, 0 ))) {
	    log( L_REMOTE "They asked me to send routing table, but he is not my neighbour" );
	    return 0;
	  }
    	  rip_sendto( p, whotoldme, port, HEAD(P->interfaces) ); /* no broadcast */
          break;
  case RIPCMD_RESPONSE: DBG( "*** Rtable from %I\n", whotoldme ); 
          if (port != P_CF->port) {
	    log( L_REMOTE "%I send me routing info from port %d", whotoldme, port );
#if 0
	    return 0;
#else
	    log( L_REMOTE "...ignoring" );
#endif
	  }

	  if (!neigh_find( p, &whotoldme, 0 )) {
	    log( L_REMOTE "%I send me routing info but he is not my neighbour", whotoldme );
#if 0
	    return 0;
#else
	    log( L_REMOTE "...ignoring" );
#endif
	  }

          for (i=0; i<num; i++) {
	    struct rip_block *block = &packet->block[i];
	    if (block->family == 0xffff) {
	      if (i)
		continue;	/* md5 tail has this family */
	      if (rip_incoming_authentication(p, (void *) block, packet, num, whotoldme))
		BAD( "Authentication failed" );
	      authenticated = 1;
	      continue;
	    }
	    if ((!authenticated) && (P_CF->authtype != AT_NONE))
	      BAD( "Packet is not authenticated and it should be" );
	    ipa_ntoh( block->network );
#ifndef IPV6
	    ipa_ntoh( block->netmask );
	    ipa_ntoh( block->nexthop );
	    if (packet->heading.version == RIP_V1)	/* FIXME (nonurgent): switch to disable this? */
	      block->netmask = ipa_class_mask(block->network);
#endif
	    process_block( p, block, whotoldme );
	  }
          break;
  case RIPCMD_TRACEON:
  case RIPCMD_TRACEOFF: BAD( "I was asked for traceon/traceoff" );
  case 5: BAD( "Some Sun extension around here" );
  default: BAD( "Unknown command" );
  }

  return 0;
}

static int
rip_rx(sock *s, int size)
{
  struct rip_interface *i = s->data;
  struct proto *p = i->proto;
  int num;

  CHK_MAGIC;
  DBG( "RIP: message came: %d bytes\n", size );
  size -= sizeof( struct rip_packet_heading );
  if (size < 0) BAD( "Too small packet" );
  if (size % sizeof( struct rip_block )) BAD( "Odd sized packet" );
  num = size / sizeof( struct rip_block );
  if (num>25) BAD( "Too many blocks" );

  rip_process_packet( p, (struct rip_packet *) s->rbuf, num, s->faddr, s->fport );
  return 1;
}

/*
 * Interface to rest of bird
 */

static void
rip_dump_entry( struct rip_entry *e )
{
  debug( "%I told me %d/%d ago: to %I/%d go via %I, metric %d ", 
  e->whotoldme, e->updated-now, e->changed-now, e->n.prefix, e->n.pxlen, e->nexthop, e->metric );
  if (e->flags & RIP_F_EXTERNAL) debug( "[external]" );
  debug( "\n" );
}

static void
rip_timer(timer *t)
{
  struct proto *p = t->data;
  struct rip_entry *e, *et;

  CHK_MAGIC;
  DBG( "RIP: tick tock\n" );
  
  WALK_LIST_DELSAFE( e, et, P->garbage ) {
    rte *rte;
    rte = SKIP_BACK( struct rte, u.rip.garbage, e );
    DBG( "Garbage: " ); rte_dump( rte );

    if (now - rte->u.rip.lastmodX > P_CF->timeout_time) {
      TRACE(D_EVENTS, "RIP: entry is too old: %I", rte->net->n.prefix );
      e->metric = P_CF->infinity;
    }

    if (now - rte->u.rip.lastmodX > P_CF->garbage_time) {
      TRACE(D_EVENTS, "RIP: entry is much too old: %I", rte->net->n.prefix );
      rte_discard(p->table, rte);
    }
  }

  DBG( "RIP: Broadcasting routing tables\n" );
  {
    struct rip_interface *rif;
    P->tx_count ++;

    WALK_LIST( rif, P->interfaces ) {
      struct iface *iface = rif->iface;

      if (!iface) continue;
      if (rif->patt->mode & IM_QUIET) continue;
      if (!(iface->flags & IF_UP)) continue;

      rif->triggered = (P->tx_count % 6);
      rip_sendto( p, IPA_NONE, 0, rif );
    }
  }

  DBG( "RIP: tick tock done\n" );
}

static int
rip_start(struct proto *p)
{
  struct rip_interface *rif;
  DBG( "RIP: starting instance...\n" );

  P->magic = RIP_MAGIC;
  fib_init( &P->rtable, p->pool, sizeof( struct rip_entry ), 0, NULL );
  init_list( &P->connections );
  init_list( &P->garbage );
  init_list( &P->interfaces );
  P->timer = tm_new( p->pool );
  P->timer->data = p;
  P->timer->randomize = 5;
  P->timer->recurrent = (P_CF->period / 6)+1; 
  P->timer->hook = rip_timer;
  tm_start( P->timer, 5 );
  rif = new_iface(p, NULL, 0, NULL);	/* Initialize dummy interface */
  add_head( &P->interfaces, NODE rif );
  CHK_MAGIC;

  rip_init_instance(p);

  DBG( "RIP: ...done\n");
  return PS_UP;
}

static struct proto *
rip_init(struct proto_config *cfg)
{
  struct proto *p = proto_new(cfg, sizeof(struct rip_proto));

  return p;
}

static void
rip_dump(struct proto *p)
{
  int i;
  node *w, *e;
  struct rip_interface *rif;
  i = 0;

  CHK_MAGIC;
  WALK_LIST( w, P->connections ) {
    struct rip_connection *n = (void *) w;
    debug( "RIP: connection #%d: %I\n", n->num, n->addr );
  }
  i = 0;
  FIB_WALK( &P->rtable, e ) {
    debug( "RIP: entry #%d: ", i++ );
    rip_dump_entry( E );
  } FIB_WALK_END;
  i = 0;
  WALK_LIST( rif, P->interfaces ) {
    debug( "RIP: interface #%d: %s, %I, busy = %x\n", i++, rif->iface?rif->iface->name:"(dummy)", rif->sock->daddr, rif->busy );
  }
}

static void
rip_get_route_info(rte *rte, byte *buf)
{
  buf += bsprintf(buf, " (%d/%d)", rte->pref, rte->u.rip.metric );
  bsprintf(buf, " t%04x", rte->u.rip.tag );
}

static int
rip_want_this_if(struct rip_interface *iface)
{
  return 1;
}

static void
kill_iface(struct proto *p, struct rip_interface *i)
{
  DBG( "RIP: Interface %s disappeared\n", i->iface->name);
  rfree(i->sock);
  mb_free(i);
}

/*
 * new maybe null if we are creating initial send socket 
 */
static struct rip_interface *
new_iface(struct proto *p, struct iface *new, unsigned long flags, struct iface_patt *patt )
{
  struct rip_interface *rif;

  rif = mb_allocz(p->pool, sizeof( struct rip_interface ));
  rif->iface = new;
  rif->proto = p;
  rif->busy = NULL;
  rif->patt = (struct rip_patt *) patt;

  if (rif->patt)
    rif->multicast = (!(rif->patt->mode & IM_BROADCAST)) && (flags & IF_MULTICAST);
  /* lookup multicasts over unnumbered links - no: rip is not defined over unnumbered links */

  if (rif->multicast)
    DBG( "Doing multicasts!\n" );

  rif->sock = sk_new( p->pool );
  rif->sock->type = rif->multicast?SK_UDP_MC:SK_UDP;
  rif->sock->sport = P_CF->port;
  rif->sock->rx_hook = rip_rx;
  rif->sock->data = rif;
  rif->sock->rbsize = 10240;
  rif->sock->iface = new;		/* Automagically works for dummy interface */
  rif->sock->tbuf = mb_alloc( p->pool, sizeof( struct rip_packet ));
  rif->sock->tx_hook = rip_tx;
  rif->sock->err_hook = rip_tx_err;
  rif->sock->daddr = IPA_NONE;
  rif->sock->dport = P_CF->port;
  if (new)
    rif->sock->ttl = 1;
  else
    rif->sock->ttl = 30;
  rif->sock->tos = IP_PREC_INTERNET_CONTROL;

  if (new) {
    if (new->addr->flags & IA_UNNUMBERED)
      log( L_WARN "%s: rip is not defined over unnumbered links", P_NAME );
    if (rif->multicast) {
      rif->sock->daddr = ipa_from_u32(0xe0000009);
      rif->sock->saddr = ipa_from_u32(0xe0000009);
    } else
      rif->sock->daddr = new->addr->brd;
  }

  if (!ipa_nonzero(rif->sock->daddr)) {
    log( L_WARN "%s: interface %s is too strange for me", P_NAME, rif->iface ? rif->iface->name : "(dummy)" );
  } else
    if (!(rif->patt->mode & IM_NOLISTEN))
      if (sk_open(rif->sock)<0) {
	log( L_ERR "%s: could not listen on %s", P_NAME, rif->iface ? rif->iface->name : "(dummy)" );
	/* Don't try to transmit into this one? Well, why not? This should not happen, anyway :-) */
      }

  TRACE(D_EVENTS, "%s: listening on %s, port %d, mode %s (%I)", P_NAME, rif->iface ? rif->iface->name : "(dummy)", P_CF->port, rif->multicast ? "multicast" : "broadcast", rif->sock->daddr );
  
  return rif;
}

static void
rip_real_if_add(struct object_lock *lock)
{
  struct iface *iface = lock->iface;
  struct proto *p = lock->data;
  struct rip_interface *rif;
  struct iface_patt *k = iface_patt_match(&P_CF->iface_list, iface);

  if (!k)
    bug("This can not happen! It existed few seconds ago!" );
  DBG("adding interface %s\n", iface->name );
  rif = new_iface(p, iface, iface->flags, k);
  add_head( &P->interfaces, NODE rif );
  rif->lock = lock;
}

static void
rip_if_notify(struct proto *p, unsigned c, struct iface *iface)
{
  DBG( "RIP: if notify\n" );
  if (iface->flags & IF_IGNORE)
    return;
  if (c & IF_CHANGE_DOWN) {
    struct rip_interface *i;
    i = find_interface(p, iface);
    if (i) {
      rem_node(NODE i);
      kill_iface(p, i);
      rfree(i->lock);
    }
  }
  if (c & IF_CHANGE_UP) {
    struct rip_interface *rif;
    struct iface_patt *k = iface_patt_match(&P_CF->iface_list, iface);
    struct object_lock *lock;

    if (!k) return; /* We are not interested in this interface */
    
    lock = olock_new( p->pool );
    lock->addr = ipa_from_u32(0xe0000009);
    lock->port = P_CF->port;
    lock->iface = iface;
    lock->hook = rip_real_if_add;
    lock->data = p;
    lock->type = OBJLOCK_UDP;
    olock_acquire(lock);
  }
}

static struct ea_list *
rip_gen_attrs(struct proto *p, struct linpool *pool, int metric, u16 tag)
{
  struct ea_list *l = lp_alloc(pool, sizeof(struct ea_list) + 2*sizeof(eattr));

  l->next = NULL;
  l->flags = EALF_SORTED;
  l->count = 2;
  l->attrs[0].id = EA_RIP_TAG;
  l->attrs[0].flags = 0;
  l->attrs[0].type = EAF_TYPE_INT | EAF_TEMP;
  l->attrs[0].u.data = tag;
  l->attrs[1].id = EA_RIP_METRIC;
  l->attrs[1].flags = 0;
  l->attrs[1].type = EAF_TYPE_INT | EAF_TEMP;
  l->attrs[1].u.data = metric;
  return l;
}

static int
rip_import_control(struct proto *p, struct rte **rt, struct ea_list **attrs, struct linpool *pool)
{
  if ((*rt)->attrs->proto == p)	/* My own must not be touched */
    return 1;

  if ((*rt)->attrs->source != RTS_RIP) {
    struct ea_list *new = rip_gen_attrs(p, pool, 1, 0);
    new->next = *attrs;
    *attrs = new;
  }
  return 0;
}

static struct ea_list *
rip_make_tmp_attrs(struct rte *rt, struct linpool *pool)
{
  struct proto *p = rt->attrs->proto;
  return rip_gen_attrs(p, pool, rt->u.rip.metric, rt->u.rip.tag);
}

static void 
rip_store_tmp_attrs(struct rte *rt, struct ea_list *attrs)
{
  struct proto *p = rt->attrs->proto;

  rt->u.rip.tag = ea_find(attrs, EA_RIP_TAG)->u.data;
  rt->u.rip.metric = ea_find(attrs, EA_RIP_METRIC)->u.data;
}

static void
rip_rt_notify(struct proto *p, struct network *net, struct rte *new, struct rte *old, struct ea_list *attrs)
{
  CHK_MAGIC;

  if (old) {
    struct rip_entry *e = fib_find( &P->rtable, &net->n.prefix, net->n.pxlen );
    if (!e)
      log( L_BUG "Deleting nonexistent entry?!" );
    fib_delete( &P->rtable, e );
  }

  if (new) {
    struct rip_entry *e;
    if (fib_find( &P->rtable, &net->n.prefix, net->n.pxlen ))
      log( L_BUG "Inserting entry which is already there?" );
    e = fib_get( &P->rtable, &net->n.prefix, net->n.pxlen );

    e->nexthop = new->attrs->gw;
    e->metric = 0;
    e->whotoldme = IPA_NONE;

    e->tag = ea_find(attrs, EA_RIP_TAG)->u.data;
    e->metric = ea_find(attrs, EA_RIP_METRIC)->u.data;
    if (e->metric > P_CF->infinity)
      e->metric = P_CF->infinity;

    if (new->attrs->proto == p)
      e->whotoldme = new->attrs->from;

    if (!e->metric)	/* This is metric for external routes. Notice
			   that I do honour it even if it comes from other protocol than this
			   rip. That's okay: this way user can set his own value for external
			   routes in rip. */
      e->metric = 5;
    e->updated = e->changed = now;
    e->flags = 0;
  }
}

static int
rip_rte_better(struct rte *new, struct rte *old)
{
  struct proto *p = new->attrs->proto;

  if (ipa_equal(old->attrs->from, new->attrs->from))
    return 1;

  if (old->u.rip.metric < new->u.rip.metric)
    return 0;

  if (old->u.rip.metric > new->u.rip.metric)
    return 1;

  if ((old->u.rip.metric < 16) && (new->u.rip.metric == P_CF->infinity)) {
    new->u.rip.lastmodX = now - P_CF->timeout_time;	/* Check this: if new metric is 16, act as it was timed out */
  }

  if (old->attrs->proto == new->attrs->proto)		/* This does not make much sense for different protocols */
    if ((old->u.rip.metric == new->u.rip.metric) &&
	((now - old->u.rip.lastmodX) > (P_CF->timeout_time / 2)))
      return 1;

  return 0;
}

static void
rip_rte_insert(net *net, rte *rte)
{
  struct proto *p = rte->attrs->proto;
  rte->u.rip.lastmodX = now;
  add_head( &P->garbage, &rte->u.rip.garbage );
}

static void
rip_rte_remove(net *net, rte *rte)
{
  struct proto *p = rte->attrs->proto;
  rem_node( &rte->u.rip.garbage );
}

void
rip_init_instance(struct proto *p)
{
  p->preference = DEF_PREF_RIP;
  p->if_notify = rip_if_notify;
  p->rt_notify = rip_rt_notify;
  p->import_control = rip_import_control;
  p->make_tmp_attrs = rip_make_tmp_attrs;
  p->store_tmp_attrs = rip_store_tmp_attrs;
  p->rte_better = rip_rte_better;
  p->rte_insert = rip_rte_insert;
  p->rte_remove = rip_rte_remove;
}

void
rip_init_config(struct rip_proto_config *c)
{
  init_list(&c->iface_list);
  c->infinity	= 16;
  c->port	= 520;
  c->period	= 30;
  c->garbage_time = 120+180;
  c->timeout_time = 120;
  c->passwords	= NULL;
  c->authtype	= AT_NONE;
}

static void
rip_preconfig(struct protocol *x, struct config *c)
{
  DBG( "RIP: preconfig\n" );
}

struct protocol proto_rip = {
  name: "RIP",
  template: "rip%d",
  preconfig: rip_preconfig,
  get_route_info: rip_get_route_info,

  init: rip_init,
  dump: rip_dump,
  start: rip_start,
};