bird/proto/pipe/pipe.c
Ondrej Zajicek dca75fd7c2 Removes phantom protocol from the pipe design.
It seems that by adding one pipe-specific exception to route
announcement code and by adding one argument to rt_notify() callback i
could completely eliminate the need for the phantom protocol instance
and therefore make the code more straightforward. It will also fix some
minor bugs (like ignoring debug flag changes from the command line).
2010-02-13 12:26:26 +01:00

190 lines
4.4 KiB
C

/*
* BIRD -- Table-to-Table Routing Protocol a.k.a Pipe
*
* (c) 1999--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
/**
* DOC: Pipe
*
* The Pipe protocol is very simple. It just connects to two routing tables
* using proto_add_announce_hook() and whenever it receives a rt_notify()
* about a change in one of the tables, it converts it to a rte_update()
* in the other one.
*
* To avoid pipe loops, Pipe keeps a `being updated' flag in each routing
* table.
*/
#undef LOCAL_DEBUG
#include "nest/bird.h"
#include "nest/iface.h"
#include "nest/protocol.h"
#include "nest/route.h"
#include "conf/conf.h"
#include "filter/filter.h"
#include "lib/string.h"
#include "pipe.h"
static void
pipe_rt_notify(struct proto *P, rtable *src_table, net *n, rte *new, rte *old, ea_list *attrs)
{
struct pipe_proto *p = (struct pipe_proto *) P;
rtable *dest = (src_table == P->table) ? p->peer : P->table; /* The other side of the pipe */
struct proto *src;
net *nn;
rte *e;
rta a;
if (!new && !old)
return;
if (dest->pipe_busy)
{
log(L_ERR "Pipe loop detected when sending %I/%d to table %s",
n->n.prefix, n->n.pxlen, dest->name);
return;
}
nn = net_get(dest, n->n.prefix, n->n.pxlen);
if (new)
{
memcpy(&a, new->attrs, sizeof(rta));
if (p->mode == PIPE_OPAQUE)
{
a.proto = &p->p;
a.source = RTS_PIPE;
}
a.aflags = 0;
a.eattrs = attrs;
e = rte_get_temp(&a);
e->net = nn;
e->pflags = 0;
if (p->mode == PIPE_TRANSPARENT)
{
/* Copy protocol specific embedded attributes. */
memcpy(&(e->u), &(new->u), sizeof(e->u));
e->pref = new->pref;
e->pflags = new->pflags;
}
src = new->attrs->proto;
}
else
{
e = NULL;
src = old->attrs->proto;
}
src_table->pipe_busy = 1;
rte_update(dest, nn, &p->p, (p->mode == PIPE_OPAQUE) ? &p->p : src, e);
src_table->pipe_busy = 0;
}
static int
pipe_import_control(struct proto *P, rte **ee, ea_list **ea UNUSED, struct linpool *p UNUSED)
{
struct proto *pp = (*ee)->sender;
if (pp == P)
return -1; /* Avoid local loops automatically */
return 0;
}
static int
pipe_reload_routes(struct proto *P)
{
/*
* Because the pipe protocol feeds routes from both routing tables
* together, both directions are reloaded during refeed and 'reload
* out' command works like 'reload' command. For symmetry, we also
* request refeed when 'reload in' command is used.
*/
proto_request_feeding(P);
return 1;
}
static int
pipe_start(struct proto *P)
{
struct pipe_proto *p = (struct pipe_proto *) P;
struct announce_hook *a;
/* Clean up the secondary stats */
bzero(&p->peer_stats, sizeof(struct proto_stats));
/* Lock the peer table, unlock is handled in proto_fell_down() */
rt_lock_table(p->peer);
/* Connect the protocol also to the peer routing table. */
a = proto_add_announce_hook(P, p->peer);
return PS_UP;
}
static struct proto *
pipe_init(struct proto_config *C)
{
struct pipe_config *c = (struct pipe_config *) C;
struct proto *P = proto_new(C, sizeof(struct pipe_proto));
struct pipe_proto *p = (struct pipe_proto *) P;
p->peer = c->peer->table;
p->mode = c->mode;
P->accept_ra_types = (p->mode == PIPE_OPAQUE) ? RA_OPTIMAL : RA_ANY;
P->rt_notify = pipe_rt_notify;
P->import_control = pipe_import_control;
P->reload_routes = pipe_reload_routes;
return P;
}
static void
pipe_postconfig(struct proto_config *C)
{
struct pipe_config *c = (struct pipe_config *) C;
if (!c->peer)
cf_error("Name of peer routing table not specified");
if (c->peer == C->table)
cf_error("Primary table and peer table must be different");
}
static void
pipe_get_status(struct proto *P, byte *buf)
{
struct pipe_proto *p = (struct pipe_proto *) P;
bsprintf(buf, "%c> %s", (p->mode == PIPE_OPAQUE) ? '-' : '=', p->peer->name);
}
static int
pipe_reconfigure(struct proto *P, struct proto_config *new)
{
struct pipe_proto *p = (struct pipe_proto *) P;
struct pipe_config *o = (struct pipe_config *) P->cf;
struct pipe_config *n = (struct pipe_config *) new;
if ((o->peer->table != n->peer->table) || (o->mode != n->mode))
return 0;
return 1;
}
struct protocol proto_pipe = {
name: "Pipe",
template: "pipe%d",
postconfig: pipe_postconfig,
init: pipe_init,
start: pipe_start,
reconfigure: pipe_reconfigure,
get_status: pipe_get_status,
};