VPLS signaling support.

This patch introduces full support for pseudowire signaling in ldpd(8),
including Control Word and Status TLV negotiation.

As of now it's not possible to configure a VPWS, but the signaling is
the same. In the future, when VPWS support is available in the kernel,
ldpd(8) can be extended to support VPWS with only a few modifications.

Limitations:
* No support for FEC 129, only FEC 128 (more widely deployed);
* No support for group withdraws (not widely deployed);
* No support for MAC withdraws (not widely deployed).

Related RFCs:
* RFC 3916: Requirements for Pseudo-Wire Emulation Edge-to-Edge (PWE3)
* RFC 3985: Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture
* RFC 4385: Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for
  Use over an MPLS PSN
* RFC 4446: IANA Allocations for Pseudowire Edge to Edge Emulation (PWE3)
* RFC 4447: Pseudowire Setup and Maintenance Using the Label Distribution
  Protocol (LDP)
* RFC 4448: Encapsulation Methods for Transport of Ethernet over MPLS
  Networks
* RFC 4905: Encapsulation Methods for Transport of Layer 2 Frames over
  MPLS Networks
* RFC 4906: Transport of Layer 2 Frames Over MPLS

ok claudio@

1 files changed, 2 insertions, 2 deletions

diff --git a/usr.sbin/ldpd/hello.c b/usr.sbin/ldpd/hello.c
index 891042b0fde..1ef5b19fde3 100644
--- a/usr.sbin/ldpd/hello.c
+++ b/usr.sbin/ldpd/hello.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hello.c,v 1.27 2015/07/21 04:43:28 renato Exp $ */
+/*	$OpenBSD: hello.c,v 1.28 2015/07/21 04:52:29 renato Exp $ */
 
 /*
  * Copyright (c) 2009 Michele Marchetto <michele@openbsd.org>
@@ -66,7 +66,7 @@ send_hello(enum hello_type type, struct iface *iface, struct tnbr *tnbr)
 		dst.sin_addr.s_addr = tnbr->addr.s_addr;
 		holdtime = tnbr->hello_holdtime;
 		flags = TARGETED_HELLO;
-		if (tnbr->flags & F_TNBR_CONFIGURED)
+		if ((tnbr->flags & F_TNBR_CONFIGURED) || tnbr->pw_count)
 			flags |= REQUEST_TARG_HELLO;
 		fd = tnbr->discovery_fd;
 		break;