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/*
* 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_send(struct pipe_proto *p, rtable *src_table, rtable *dest, net *n, rte *new, rte *old, ea_list *attrs)
{
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 void
pipe_rt_notify_pri(struct proto *P, net *net, rte *new, rte *old, ea_list *attrs)
{
struct pipe_proto *p = (struct pipe_proto *) P;
DBG("PIPE %c> %I/%d\n", (new ? '+' : '-'), net->n.prefix, net->n.pxlen);
pipe_send(p, p->p.table, p->peer, net, new, old, attrs);
}
static void
pipe_rt_notify_sec(struct proto *P, net *net, rte *new, rte *old, ea_list *attrs)
{
struct pipe_proto *p = ((struct pipe_proto *) P)->phantom;
DBG("PIPE %c< %I/%d\n", (new ? '+' : '-'), net->n.prefix, net->n.pxlen);
pipe_send(p, p->peer, p->p.table, net, new, old, attrs);
}
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 || pp == &((struct pipe_proto *) P)->phantom->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 pipe_proto *ph;
struct announce_hook *a;
/*
* Create a phantom protocol which will represent the remote
* end of the pipe (we need to do this in order to get different
* filters and announce functions and it unfortunately involves
* a couple of magic trickery).
*/
ph = mb_alloc(P->pool, sizeof(struct pipe_proto));
memcpy(ph, p, sizeof(struct pipe_proto));
p->phantom = ph;
ph->phantom = p;
ph->p.accept_ra_types = (p->mode == PIPE_OPAQUE) ? RA_OPTIMAL : RA_ANY;
ph->p.rt_notify = pipe_rt_notify_sec;
ph->p.proto_state = PS_UP;
ph->p.core_state = ph->p.core_goal = FS_HAPPY;
/*
* Routes should be filtered in the do_rte_announce() (export
* filter for protocols). Reverse direction is handled by putting
* specified import filter to out_filter field of the phantom
* protocol.
*
* in_filter fields are not important, there is an exception in
* rte_update() to ignore it for pipes. We cannot just set
* P->in_filter to FILTER_ACCEPT, because that would break other
* things (reconfiguration, show-protocols command).
*/
ph->p.in_filter = FILTER_ACCEPT;
ph->p.out_filter = P->in_filter;
/*
* Connect the phantom protocol to the peer routing table, but
* keep it in the list of connections of the primary protocol,
* so that it gets disconnected at the right time and we also
* get all routes from both sides during the feeding phase.
*/
a = proto_add_announce_hook(P, p->peer);
a->proto = &ph->p;
rt_lock_table(p->peer);
return PS_UP;
}
static int
pipe_shutdown(struct proto *P)
{
struct pipe_proto *p = (struct pipe_proto *) P;
rt_unlock_table(p->peer);
return PS_DOWN;
}
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_pri;
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;
/* Update also the filter in the phantom protocol */
p->phantom->p.out_filter = new->in_filter;
return 1;
}
struct protocol proto_pipe = {
name: "Pipe",
template: "pipe%d",
postconfig: pipe_postconfig,
init: pipe_init,
start: pipe_start,
shutdown: pipe_shutdown,
reconfigure: pipe_reconfigure,
get_status: pipe_get_status,
};
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