bird/proto/rip/rip.c

534 lines
12 KiB
C

/*
* Rest in pieces - RIP protocol
*
* Copyright (c) 1998 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"
int infinity = 16;
/* FIXME: should be 520 */
#define RIP_PORT 1520
/* FIXME: should be 30 */
#define RIP_TIME 5
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
}
/*
* Entries
*/
static struct rip_entry *
new_entry( struct proto *p )
{
struct rip_entry *e;
e = mb_alloc(p->pool, sizeof( struct rip_entry ));
bzero( e, sizeof( struct rip_entry ));
return e;
}
static struct rip_entry *
find_entry( struct proto *p, ip_addr network, int pxlen )
{
struct node *e;
CHK_MAGIC;
WALK_LIST( e, P->rtable ) {
if (ipa_equal( network, E->network ) &&
(pxlen == E->pxlen)) {
return E;
}
}
return NULL;
}
/* Delete one of entries */
static void
kill_entry_ourrt( struct proto *p, struct rip_entry *e )
{
struct rip_connection *c;
net *n;
rem_node( NODE e );
WALK_LIST( c, P->connections ) {
if (c->sendptr == e) {
debug( "Deleting from under someone's sendptr...\n" );
c->sendptr = (void *) (NODE c->sendptr)->next;
}
}
mb_free( e );
}
#if 0
/* Currently unreferenced, and likely may stay that way */
/* Delete one of entries */
static void
kill_entry_mainrt( struct proto *p, struct rip_entry *e )
{
struct rip_connection *c;
net *n;
n = net_find(&master_table, 0, e->network, e->pxlen );
if (!n) log( L_ERR "Could not find entry to delete in main routing table.\n" );
else rte_update( n, p, NULL );
}
static void
kill_entry( struct proto *p, struct rip_entry *e )
{
kill_entry_mainrt( p, e );
kill_entry_ourrt( p, e );
}
#endif
/*
* 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\n" );
}
static void
rip_tx( sock *s )
{
struct rip_connection *c = s->data;
struct proto *p = c->proto;
struct rip_packet *packet = (void *) s->tbuf;
int i, done = 0;
givemore:
debug( "Preparing packet to send: " );
if (!(NODE c->sendptr)->next) {
debug( "Looks like I'm done\n" );
return;
}
packet->heading.command = RIPCMD_RESPONSE;
packet->heading.version = RIP_V2;
packet->heading.unused = 0;
for (i = 0; i < 25; i++) {
if (!(NODE c->sendptr)->next)
break;
debug( "." );
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 = c->sendptr->network;
packet->block[i].netmask = ipa_mkmask( c->sendptr->pxlen );
packet->block[i].nexthop = IPA_NONE; /* FIXME: How should I set it? */
packet->block[i].metric = htonl( c->sendptr->metric );
if (ipa_equal(c->sendptr->whotoldme, s->daddr)) {
debug( "(split horizont)" );
/* FIXME: should we do it in all cases? */
packet->block[i].metric = infinity;
}
ipa_hton( packet->block[i].network );
ipa_hton( packet->block[i].netmask );
ipa_hton( packet->block[i].nexthop );
c->sendptr = (void *) (NODE c->sendptr)->next;
}
debug( ", sending %d blocks, ", i );
i = sk_send( s, sizeof( struct rip_packet_heading ) + i*sizeof( struct rip_block ) );
if (i<0) rip_tx_err( s, i );
if (i>0) {
debug( "it wants more\n" );
goto givemore;
}
debug( "blocked\n" );
}
static void
rip_sendto( struct proto *p, ip_addr daddr, int dport )
{
struct rip_connection *c = mb_alloc( p->pool, sizeof( struct rip_connection ));
static int num = 0;
c->addr = daddr;
c->proto = p;
c->num = num++;
c->send = sk_new( p->pool );
c->send->type = SK_UDP;
c->send->sport = RIP_PORT;
c->send->dport = dport;
c->send->daddr = daddr;
c->send->rx_hook = NULL;
c->send->tx_hook = rip_tx;
c->send->err_hook = rip_tx_err;
c->send->data = c;
c->send->tbuf = mb_alloc( p->pool, sizeof( struct rip_packet ));
if (sk_open(c->send)<0) {
log( L_ERR "Could not open socket for data send to %I:%d\n", daddr, dport );
return;
}
c->sendptr = HEAD( P->rtable );
add_head( &P->connections, NODE c );
debug( "Sending my routing table to %I:%d\n", daddr, dport );
rip_tx( c->send );
}
/*
* Input processing
*/
static int
process_authentication( struct proto *p, struct rip_block *block )
{
/* FIXME: Should do md5 authentication */
return 0;
}
/* 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;
debug( "rip: Advertising entry..." );
bzero(&A, sizeof(A));
A.proto = p;
A.source = RTS_RIP;
A.scope = SCOPE_UNIVERSE;
A.cast = RTC_UNICAST;
A.dest = RTD_ROUTER;
A.tos = 0;
A.flags = 0;
A.gw = ipa_nonzero(b->nexthop) ? b->nexthop : whotoldme;
A.from = whotoldme;
A.iface = /* FIXME: need to set somehow */ NULL;
/* set to: interface of nexthop */
a = rta_lookup(&A);
n = net_get( &master_table, 0, b->network, ipa_mklen( b->netmask )); /* FIXME: should verify that it really is netmask */
r = rte_get_temp(a);
r->u.rip.metric = ntohl(b->metric);
r->u.rip.tag = ntohl(b->tag);
r->pflags = 0; /* Here go my flags */
rte_update( n, p, r );
debug( "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 > infinity)) {
log( L_WARN "Got metric %d from %I\n", metric, whotoldme );
return;
}
/* FIXME: Check if destination looks valid - ie not net 0 or 127 */
/* FIXME: Should add configurable ammount */
if (metric < infinity)
metric++;
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 "\n", 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: debug( "Rip1: " ); break;
case RIP_V2: debug( "Rip2: " ); break;
default: BAD( "Unknown version" );
}
switch( packet->heading.command ) {
case RIPCMD_REQUEST: debug( "Asked to send my routing table\n" );
rip_sendto( p, whotoldme, port );
break;
case RIPCMD_RESPONSE: debug( "Part of routing table came\n" );
if (port != RIP_PORT) {
log( L_AUTH "%I send me routing info from port %d\n", whotoldme, port );
return 0;
}
if (!neigh_find( p, &whotoldme, 0 )) {
log( L_AUTH "%I send me routing info but he is not my neighbour\n", 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 (process_authentication(p, block))
BAD( "Authentication failed\n" );
} 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\n" );
case 5: BAD( "Some Sun extension around here\n" );
default: BAD( "Unknown command" );
}
rip_reply(p);
return 0;
}
static int
rip_rx(sock *s, int size)
{
struct proto *p = s->data;
int num;
CHK_MAGIC;
debug( "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->network, e->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;
debug( "RIP: tick tock\n" );
#if 0
/* This needs to be completely redone. We need garbage collecting based on main routing table, not on our copy */
WALK_LIST_DELSAFE( e, et, P->rtable ) {
if (!(E->flags & RIP_F_EXTERNAL))
if ((now - E->updated) > (180+120)) {
debug( "RIP: entry is too old: " );
rip_dump_entry( E );
kill_entry( p, E );
}
}
#endif
#if 0
debug( "RIP: Broadcasting routing tables\n" );
rip_sendto( p, _MI( 0x0a000001 ), RIP_PORT );
#endif
/* FIXME: Should broadcast routing tables to all known interfaces every 30 seconds */
debug( "RIP: tick tock done\n" );
}
static void
rip_start(struct proto *p)
{
debug( "RIP: initializing instance...\n" );
P->listen = sk_new( p->pool );
P->listen->type = SK_UDP;
P->listen->sport = RIP_PORT;
P->listen->rx_hook = rip_rx;
P->listen->data = p;
P->listen->rbsize = 10240;
P->magic = RIP_MAGIC;
if (sk_open(P->listen)<0)
die( "RIP/%s: could not listen\n", p->name );
init_list( &P->rtable );
init_list( &P->connections );
P->timer = tm_new( p->pool );
P->timer->data = p;
P->timer->randomize = 5;
P->timer->recurrent = RIP_TIME;
P->timer->hook = rip_timer;
tm_start( P->timer, 5 );
CHK_MAGIC;
debug( "RIP: ...done\n");
}
static void
rip_init(struct protocol *p)
{
debug( "RIP: initializing RIP...\n" );
}
static void
rip_dump(struct proto *p)
{
int i;
node *w, *e;
i = 0;
WALK_LIST( w, P->connections ) {
struct rip_connection *n = (void *) w;
debug( "RIP: connection #%d: %I\n", n->num, n->addr );
}
i = 0;
WALK_LIST( e, P->rtable ) {
debug( "RIP: entry #%d: ", i++ );
rip_dump_entry( E );
}
}
static void
rip_if_notify(struct proto *p, unsigned c, struct iface *old, struct iface *new)
{
}
static void
rip_rt_notify(struct proto *p, struct network *net, struct rte *new, struct rte *old)
{
debug( "rip: new entry came: " );
CHK_MAGIC;
if (old) {
struct rip_entry *e = find_entry( p, net->n.prefix, net->n.pxlen );
debug( "deleting old\n" );
if (!e)
log( L_ERR "Deleting nonexistent entry?!\n" );
kill_entry_ourrt( p, e );
}
if (new) {
struct rip_entry *e = new_entry( p );
debug( "inserting new\n" );
e->network = net->n.prefix;
e->pxlen = 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;
add_head( &P->rtable, NODE e );
}
}
static int /* FIXME: should not they pass me struct proto * ? */
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 int
rip_rta_same(rta *a, rta *b)
{
debug( "RIP: they ask me if rta_same\n" );
/* As we have no specific data in rta, they are always the same */
return 1;
}
static void
rip_preconfig(struct protocol *x)
{
struct proto *p = proto_new(&proto_rip, sizeof(struct rip_data));
debug( "RIP: preconfig\n" );
p->preference = DEF_PREF_DIRECT;
p->start = rip_start;
p->if_notify = rip_if_notify;
p->rt_notify = rip_rt_notify;
p->rte_better = rip_rte_better;
p->rta_same = rip_rta_same;
p->dump = rip_dump;
}
static void
rip_postconfig(struct protocol *p)
{
}
struct protocol proto_rip = {
{ NULL, NULL },
"RIP",
0,
rip_init,
rip_preconfig,
rip_postconfig
};