Forgot to do a `cvs add', grr.

proto/pipe/Makefile

+source=pipe.c
+root-rel=../../
+dir-name=proto/pipe
+
+include ../../Rules
+

proto/pipe/config.Y

+/*
+ *	BIRD -- Table-to-Table Protocol Configuration
+ *
+ *	(c) 1999 Martin Mares <mj@ucw.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+CF_HDR
+
+#include "proto/pipe/pipe.h"
+
+CF_DECLS
+
+CF_KEYWORDS(PIPE, PEER, TABLE)
+
+CF_GRAMMAR
+
+CF_ADDTO(proto, pipe_proto '}')
+
+pipe_proto_start: proto_start PIPE {
+     this_proto = proto_config_new(&proto_pipe, sizeof(struct pipe_config));
+     this_proto->preference = DEF_PREF_PIPE;
+  }
+ ;
+
+pipe_proto:
+   pipe_proto_start proto_name '{'
+ | pipe_proto proto_item ';'
+ | pipe_proto PEER TABLE SYM ';' {
+     if ($4->class != SYM_TABLE)
+       cf_error("Routing table name expected");
+     ((struct pipe_config *) this_proto)->peer = $4->def;
+   }
+ ;
+
+CF_CODE
+
+CF_END

proto/pipe/pipe.c

+/*
+ *	BIRD -- Table-to-Table Routing Protocol a.k.a Pipe
+ *
+ *	(c) 1999 Martin Mares <mj@ucw.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#define 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 "pipe.h"
+
+static void
+pipe_send(struct pipe_proto *p, rtable *dest, net *n, rte *new, rte *old)
+{
+  net *nn;
+  rte *e;
+  rta a;
+
+  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));
+      a.proto = &p->p;
+      a.source = RTS_PIPE;
+      a.aflags = 0;
+      e = rte_get_temp(&a);
+      e->net = nn;
+    }
+  else
+    e = NULL;
+  dest->pipe_busy = 1;
+  rte_update(dest, nn, &p->p, e);
+  dest->pipe_busy = 0;
+}
+
+static void
+pipe_rt_notify_pri(struct proto *P, net *net, rte *new, rte *old, ea_list *tmpa)
+{
+  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->peer, net, new, old);
+}
+
+static void
+pipe_rt_notify_sec(struct proto *P, net *net, rte *new, rte *old, ea_list *tmpa)
+{
+  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->p.table, net, new, old);
+}
+
+static int
+pipe_import_control(struct proto *P, rte **ee, ea_list **ea, struct linpool *p)
+{
+  struct proto *pp = (*ee)->attrs->proto;
+
+  if (pp == P || pp == &((struct pipe_proto *) P)->phantom->p)
+    return -1;	/* Avoid local loops automatically */
+  return 0;
+}
+
+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.rt_notify = pipe_rt_notify_sec;
+  ph->p.proto_state = PS_UP;
+  ph->p.core_state = ph->p.core_goal = FS_HAPPY;
+  ph->p.in_filter = ph->p.out_filter = FILTER_ACCEPT;	/* We do all filtering on the local end */
+
+  /*
+   *  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;
+
+  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->rt_notify = pipe_rt_notify_pri;
+  P->import_control = pipe_import_control;
+  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");
+}
+
+struct protocol proto_pipe = {
+  name:		"Pipe",
+  postconfig:	pipe_postconfig,
+  init:		pipe_init,
+  start:	pipe_start,
+};

proto/pipe/pipe.h

+/*
+ *	BIRD -- Table-to-Table Routing Protocol a.k.a Pipe
+ *
+ *	(c) 1999 Martin Mares <mj@ucw.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_PIPE_H_
+#define _BIRD_PIPE_H_
+
+struct pipe_config {
+  struct proto_config c;
+  struct rtable_config *peer;		/* Table we're connected to */
+};
+
+struct pipe_proto {
+  struct proto p;
+  struct rtable *peer;
+  struct pipe_proto *phantom;
+};
+
+#endif