pathd: New SR-TE policy management daemon

This new daemon manages Segment-Routing Traffic-Engineering
(SR-TE) Policies and installs them into zebra. It provides
the usual yang support and vtysh commands to define or change
SR-TE Policies.

In a nutshell SR-TE Policies provide the possibility to steer
traffic through a (possibly dynamic) list of Segment Routing
segments to the endpoint of the policy. This list of segments
is part of a Candidate Path which again belongs to the SR-TE
Policy. SR-TE Policies are uniquely identified by their color
and endpoint. The color can be used to e.g. match BGP
communities on incoming traffic.

There can be multiple Candidate Paths for a single
policy, the active Candidate Path is chosen according to
certain conditions of which the most important is its
preference. Candidate Paths can be explicit (fixed list of
segments) or dynamic (list of segment comes from e.g. PCEP, see
below).

Configuration example:

segment-routing
 traffic-eng
  segment-list SL
   index 10 mpls label 1111
   index 20 mpls label 2222
  !
  policy color 4 endpoint 10.10.10.4
   name POL4
   binding-sid 104
   candidate-path preference 100 name exp explicit segment-list SL
   candidate-path preference 200 name dyn dynamic
  !
 !
!

There is an important connection between dynamic Candidate
Paths and the overall topic of Path Computation. Later on for
pathd a dynamic module will be introduced that is capable
of communicating via the PCEP protocol with a PCE (Path
Computation Element) which again is capable of calculating
paths according to its local TED (Traffic Engineering Database).
This dynamic module will be able to inject the mentioned
dynamic Candidate Paths into pathd based on calculated paths
from a PCE.

https://tools.ietf.org/html/draft-ietf-spring-segment-routing-policy-06

Co-authored-by: Sebastien Merle <sebastien@netdef.org>
Co-authored-by: Renato Westphal <renato@opensourcerouting.org>
Co-authored-by: GalaxyGorilla <sascha@netdef.org>
Co-authored-by: Emanuele Di Pascale <emanuele@voltanet.io>
Signed-off-by: Sebastien Merle <sebastien@netdef.org>

1 files changed, 23 insertions, 2 deletions

diff --git a/redhat/frr.spec.in b/redhat/frr.spec.in
index 4ebc504b8a..02c272f47c 100644
--- a/redhat/frr.spec.in
+++ b/redhat/frr.spec.in
@@ -27,6 +27,7 @@
 %{!?with_vrrpd:         %global  with_vrrpd         1 }
 %{!?with_rtadv:         %global  with_rtadv         1 }
 %{!?with_watchfrr:      %global  with_watchfrr      1 }
+%{!?with_pathd:         %global  with_pathd         1 }
 
 # user and group
 %{!?frr_user:           %global  frr_user           frr }
@@ -87,7 +88,7 @@
 %{!?frr_gid:            %global  frr_gid            92 }
 %{!?vty_gid:            %global  vty_gid            85 }
 
-%define daemon_list zebra ripd ospfd bgpd isisd ripngd ospf6d pbrd staticd bfdd fabricd
+%define daemon_list zebra ripd ospfd bgpd isisd ripngd ospf6d pbrd staticd bfdd fabricd pathd
 
 %if %{with_ldpd}
     %define daemon_ldpd ldpd
@@ -143,7 +144,13 @@
     %define daemon_bfdd ""
 %endif
 
-%define all_daemons %{daemon_list} %{daemon_ldpd} %{daemon_pimd} %{daemon_nhrpd} %{daemon_eigrpd} %{daemon_babeld} %{daemon_watchfrr} %{daemon_pbrd} %{daemon_bfdd} %{daemon_vrrpd}
+%if %{with_pathd}
+    %define daemon_pathd pathd
+%else
+    %define daemon_pathd ""
+%endif
+
+%define all_daemons %{daemon_list} %{daemon_ldpd} %{daemon_pimd} %{daemon_nhrpd} %{daemon_eigrpd} %{daemon_babeld} %{daemon_watchfrr} %{daemon_pbrd} %{daemon_bfdd} %{daemon_vrrpd} %{daemon_pathd}
 
 #release sub-revision (the two digits after the CONFDATE)
 %{!?release_rev:        %global  release_rev        01 }
@@ -398,6 +405,11 @@ routing state through standard SNMP MIBs.
 %else
     --disable-bfdd \
 %endif
+%if %{with_pathd}
+    --enable-pathd \
+%else
+    --disable-pathd \
+%endif
     --enable-snmp
     # end
 
@@ -526,6 +538,9 @@ zebra_spec_add_service fabricd	2618/tcp "Fabricd vty"
 %if %{with_vrrpd}
     zebra_spec_add_service vrrpd    2619/tcp "VRRPd vty"
 %endif
+%if %{with_pathd}
+    zebra_spec_add_service pathd    2620/tcp "Pathd vty"
+%endif
 
 %if "%{initsystem}" == "systemd"
     for daemon in %all_daemons ; do
@@ -681,6 +696,9 @@ fi
 %if %{with_bfdd}
     %{_sbindir}/bfdd
 %endif
+%if %{with_pathd}
+    %{_sbindir}/pathd
+%endif
 %{_libdir}/libfrr.so*
 %{_libdir}/libfrrcares*
 %{_libdir}/libfrrospf*
@@ -798,6 +816,9 @@ sed -i 's/ -M rpki//' %{_sysconfdir}/frr/daemons
 -    migrate route-maps to use northbound interface
 - plus countless bug fixes and other improvements
 
+* Mon Jun 15 2020 Sascha Kattelmann <sascha@netdef.org>
+- Add Pathd support
+
 * Wed May 06 2020 David Lamparter <equinox@opensourcerouting.org> - 7.3.1
 - upstream 7.3.1