bird/proto/pipe/pipe.c
Ondrej Zajicek a7f23f581f Implements protocol templates.
Based on the patch from Alexander V. Chernikov.
Extended to support almost all protocols.
Uses 'protocol bgp NAME from TEMPLATE { ... }' syntax.
2011-11-07 00:31:23 +01:00

207 lines
4.8 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;
a.hostentry = NULL;
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 pipe_cleanup() */
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 void
pipe_cleanup(struct proto *P)
{
struct pipe_proto *p = (struct pipe_proto *) P;
rt_unlock_table(p->peer);
}
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 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;
}
static void
pipe_copy_config(struct proto_config *dest, struct proto_config *src)
{
/* Just a shallow copy, not many items here */
proto_copy_rest(dest, src, sizeof(struct pipe_config));
}
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);
}
struct protocol proto_pipe = {
name: "Pipe",
template: "pipe%d",
postconfig: pipe_postconfig,
init: pipe_init,
start: pipe_start,
cleanup: pipe_cleanup,
reconfigure: pipe_reconfigure,
copy_config: pipe_copy_config,
get_status: pipe_get_status,
};