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bird/proto/rip/rip.c

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/*
* 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.
*/
#define LOCAL_DEBUG
#include <string.h>
#include <stdlib.h>
#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 "rip.h"
#define P ((struct rip_proto *) p)
#define P_CF ((struct rip_proto_config *)p->cf)
#define E ((struct rip_entry *) e)
static void
rip_reply(struct proto *p)
{
#if 0
P->listen->tbuf = "ACK!";
sk_send_to( P->listen, 5, P->listen->faddr, P->listen->fport );
#endif
}
#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( 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;
do {
if (c->done) {
DBG( "Looks like I'm" );
c->rif->busy = NULL;
rem_node(NODE c);
mb_free(c);
DBG( " done\n" );
return;
}
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;
DBG( "." );
packet->block[i].family = htons( 2 ); /* AF_INET */
packet->block[i].tag = htons( 0 ); /* FIXME: What should I set it to? */
packet->block[i].network = e->n.prefix;
packet->block[i].netmask = ipa_mkmask( e->n.pxlen );
packet->block[i].nexthop = IPA_NONE; /* FIXME: How should I set it? My own IP address? */
packet->block[i].metric = htonl( 1+ (e->metric?:1) ); /* FIXME: is this right? I already ++ metric at input side */
if (ipa_equal(e->whotoldme, s->daddr)) {
DBG( "(split horizont)" );
/* FIXME: should we do it in all cases? */
packet->block[i].metric = P_CF->infinity;
}
ipa_hton( packet->block[i].network );
ipa_hton( packet->block[i].netmask );
ipa_hton( packet->block[i].nexthop );
if (i++ == 25) {
FIB_ITERATE_PUT(&c->iter, z);
goto break_loop;
}
} FIB_ITERATE_END(z);
c->done = 1;
break_loop:
if (P_CF->authtype)
rip_outgoing_authentication(p, &packet->block[0], packet, i);
DBG( ", sending %d blocks, ", i );
if (ipa_nonzero(c->daddr))
i = sk_send_to( s, sizeof( struct rip_packet_heading ) + i*sizeof( struct rip_block ), c->daddr, c->dport );
else
i = sk_send( s, sizeof( struct rip_packet_heading ) + i*sizeof( struct rip_block ) );
DBG( "it wants more\n" );
} while (i>0);
if (i<0) rip_tx_err( s, i );
DBG( "blocked\n" );
}
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 = mb_alloc( p->pool, sizeof( struct rip_connection ));
static int num = 0;
if (rif->busy) {
log (L_WARN "Interface %s is much too slow, dropping request", iface->name);
return;
}
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 );
debug( "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;
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;
A.gw = ipa_nonzero(b->nexthop) ? b->nexthop : whotoldme;
A.from = whotoldme;
/* FIXME: Check if destination looks valid - ie not net 0 or 127 */
neighbor = neigh_find( p, &A.gw, 0 );
if (!neighbor) {
log( L_ERR "%I asked me to route %I/%I using not-neighbor %I.", A.from, b->network, b->netmask, 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 (ipa_mklen(b->netmask)==-1) {
log( L_ERR "%I asked me to route %I/%I, but that is not valid netmask.", A.from, b->network, b->netmask );
return;
}
n = net_get( p->table, b->network, ipa_mklen( b->netmask ));
r = rte_get_temp(a);
r->u.rip.metric = ntohl(b->metric) + rif->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( n, p, r );
DBG( "done\n" );
}
static void
process_block( struct proto *p, struct rip_block *block, ip_addr whotoldme )
{
struct rip_entry *e;
int metric = ntohl( block->metric );
ip_addr network = block->network;
CHK_MAGIC;
if ((!metric) || (metric > P_CF->infinity)) {
log( L_WARN "Got metric %d from %I", metric, whotoldme );
return;
}
debug( "block: %I tells me: %I/%I available, metric %d... ", whotoldme, network, block->netmask, metric );
advertise_entry( p, block, whotoldme );
}
#define BAD( x ) { log( L_WARN "RIP/%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;
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" );
/* FIXME: should have configurable: ignore always, honour to neighbours, honour always. FIXME: use one global socket for these. FIXME: synchronization - if two ask me at same time */
rip_sendto( p, whotoldme, port, NULL ); /* no broadcast */
break;
case RIPCMD_RESPONSE: DBG( "*** Rtable from %I\n", whotoldme );
if (port != P_CF->port) {
log( L_ERR "%I send me routing info from port %d", whotoldme, port );
#if 0
return 0;
#else
log( L_ERR "...ignoring" );
#endif
}
if (!neigh_find( p, &whotoldme, 0 )) {
log( L_ERR "%I send me routing info but he is not my neighbour", whotoldme );
return 0;
}
/* FIXME: Should check if it is not my own packet */
for (i=0; i<num; i++) {
struct rip_block *block = &packet->block[i];
if (block->family == 0xffff)
if (!i) {
if (rip_incoming_authentication(p, block, packet, num))
BAD( "Authentication failed" );
} else BAD( "Authentication is not the first!" );
ipa_ntoh( block->network );
ipa_ntoh( block->netmask );
ipa_ntoh( block->nexthop );
if (packet->heading.version == RIP_V1) {
block->netmask = block->network; /* MJ: why are macros like this?! */
ipa_class_mask( block->netmask );
}
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" );
}
rip_reply(p);
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->lastmod > P_CF->garbage_time) {
debug( "RIP: entry is too old: " ); rte_dump( rte );
rte_discard(rte);
}
}
DBG( "RIP: Broadcasting routing tables\n" );
{
struct rip_interface *rif;
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;
if (iface->flags & (IF_IGNORE | IF_LOOPBACK)) continue;
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;
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 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
*/
struct rip_interface *
new_iface(struct proto *p, struct iface *new, unsigned long flags, struct iface_patt *patt )
{
struct rip_interface *rif;
int want_multicast = 0;
rif = mb_alloc(p->pool, sizeof( struct rip_interface ));
rif->iface = new;
rif->proto = p;
rif->busy = NULL;
rif->patt = (struct rip_patt *) patt;
if (rif->patt)
want_multicast = (!(rif->patt->mode & IM_BROADCAST)) && (flags & IF_MULTICAST);
/* lookup multicasts over unnumbered links - no: rip is not defined over unnumbered links */
rif->sock = sk_new( p->pool );
rif->sock->type = want_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;
rif->sock->ttl = 1; /* FIXME: care must be taken not to send requested responses from this socket */
if (want_multicast)
rif->sock->daddr = ipa_from_u32(0xe0000009);
if (flags & IF_BROADCAST)
rif->sock->daddr = new->addr->brd;
if (flags & IF_UNNUMBERED) /* Hmm, rip is not defined over unnumbered links */
rif->sock->daddr = new->addr->opposite;
if (!ipa_nonzero(rif->sock->daddr)) {
log( L_WARN "RIP/%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_WARN "RIP/%s: could not listen on %s", P_NAME, rif->iface ? rif->iface->name : "(dummy)" );
return rif;
}
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);
}
}
if (c & IF_CHANGE_UP) {
struct rip_interface *rif;
struct iface_patt *k = iface_patt_match(&P_CF->iface_list, iface);
if (!k) return; /* We are not interested in this interface */
DBG("adding interface %s\n", iface->name );
rif = new_iface(p, iface, iface->flags, k);
add_head( &P->interfaces, NODE rif );
}
}
static void
rip_rt_notify(struct proto *p, struct network *net, struct rte *new, struct rte *old)
{
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->tag = new->u.rip.tag;
e->metric = new->u.rip.metric;
e->whotoldme = new->attrs->from;
e->updated = e->changed = now;
e->flags = 0;
}
}
static int
rip_rte_better(struct rte *new, struct rte *old)
{
if (old->u.rip.metric < new->u.rip.metric)
return 0;
if (old->u.rip.metric > new->u.rip.metric)
return 1;
#define old_metric_is_much_older_than_new_metric 0
if ((old->u.rip.metric == new->u.rip.metric) && (old_metric_is_much_older_than_new_metric))
return 1;
return 0;
}
static void
rip_rte_insert(net *net, rte *rte)
{
struct proto *p = rte->attrs->proto;
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->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->password = "PASSWORD";
c->authtype = AT_NONE;
}
static void
rip_preconfig(struct protocol *x, struct config *c)
{
DBG( "RIP: preconfig\n" );
}
static void
rip_postconfig(struct proto_config *c)
{
}
struct protocol proto_rip = {
name: "RIP",
preconfig: rip_preconfig,
postconfig: rip_postconfig,
init: rip_init,
dump: rip_dump,
start: rip_start,
};
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