lib, zebra: Add SR-TE policy infrastructure to zebra

For the sake of Segment Routing (SR) and Traffic Engineering (TE)
Policies there's a need for additional infrastructure within zebra.
The infrastructure in this PR is supposed to manage such policies
in terms of installing binding SIDs and LSPs. Also it is capable of
managing MPLS labels using the label manager, keeping track of
nexthops (for resolving labels) and notifying interested parties about
changes of a policy/LSP state. Further it enables a route map mechanism
for BGP and SR-TE colors such that learned BGP routes can be mapped
onto SR-TE Policies.

This PR does not introduce any usable features by now, it is just
infrastructure for other upcoming PRs which will introduce 'pathd',
a new SR-TE daemon.

Co-authored-by: Renato Westphal <renato@opensourcerouting.org>
Co-authored-by: GalaxyGorilla <sascha@netdef.org>
Signed-off-by: Sebastien Merle <sebastien@netdef.org>

1 files changed, 40 insertions, 3 deletions

diff --git a/lib/zclient.h b/lib/zclient.h
index da06239d01..bcd8954dde 100644
--- a/lib/zclient.h
+++ b/lib/zclient.h
@@ -37,6 +37,7 @@
 #include "pw.h"
 
 #include "mlag.h"
+#include "srte.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -89,6 +90,8 @@ enum zserv_client_capabilities {
 /* Macro to check if there GR enabled. */
 #define ZEBRA_CLIENT_GR_ENABLED(X) (X == ZEBRA_CLIENT_GR_CAPABILITIES)
 
+#define ZEBRA_SR_POLICY_NAME_MAX_LENGTH 100
+
 extern struct sockaddr_storage zclient_addr;
 extern socklen_t zclient_addr_len;
 
@@ -143,6 +146,9 @@ typedef enum {
 	ZEBRA_MPLS_LABELS_ADD,
 	ZEBRA_MPLS_LABELS_DELETE,
 	ZEBRA_MPLS_LABELS_REPLACE,
+	ZEBRA_SR_POLICY_SET,
+	ZEBRA_SR_POLICY_DELETE,
+	ZEBRA_SR_POLICY_NOTIFY_STATUS,
 	ZEBRA_IPMR_ROUTE_STATS,
 	ZEBRA_LABEL_MANAGER_CONNECT,
 	ZEBRA_LABEL_MANAGER_CONNECT_ASYNC,
@@ -351,6 +357,7 @@ struct zclient {
 	int (*opaque_msg_handler)(ZAPI_CALLBACK_ARGS);
 	int (*opaque_register_handler)(ZAPI_CALLBACK_ARGS);
 	int (*opaque_unregister_handler)(ZAPI_CALLBACK_ARGS);
+	int (*sr_policy_notify_status)(ZAPI_CALLBACK_ARGS);
 };
 
 /* Zebra API message flag. */
@@ -368,7 +375,8 @@ struct zclient {
  * the table being used is not in the VRF.  You must pass the
  * default vrf, else this will be ignored.
  */
-#define ZAPI_MESSAGE_TABLEID  0x80
+#define ZAPI_MESSAGE_TABLEID 0x0080
+#define ZAPI_MESSAGE_SRTE 0x0100
 
 #define ZSERV_VERSION 6
 /* Zserv protocol message header */
@@ -403,6 +411,9 @@ struct zapi_nexthop {
 	/* Backup nexthops, for IP-FRR, TI-LFA, etc */
 	uint8_t backup_num;
 	uint8_t backup_idx[NEXTHOP_MAX_BACKUPS];
+
+	/* SR-TE color. */
+	uint32_t srte_color;
 };
 
 /*
@@ -465,7 +476,7 @@ struct zapi_route {
 #define ZEBRA_FLAG_RR_USE_DISTANCE    0x40
 
 	/* The older XXX_MESSAGE flags live here */
-	uint8_t message;
+	uint32_t message;
 
 	/*
 	 * This is an enum but we are going to treat it as a uint8_t
@@ -494,6 +505,9 @@ struct zapi_route {
 	vrf_id_t vrf_id;
 
 	uint32_t tableid;
+
+	/* SR-TE color (used for nexthop updates only). */
+	uint32_t srte_color;
 };
 
 struct zapi_labels {
@@ -516,6 +530,21 @@ struct zapi_labels {
 	struct zapi_nexthop backup_nexthops[MULTIPATH_NUM];
 };
 
+struct zapi_srte_tunnel {
+	enum lsp_types_t type;
+	mpls_label_t local_label;
+	uint8_t label_num;
+	mpls_label_t labels[MPLS_MAX_LABELS];
+};
+
+struct zapi_sr_policy {
+	uint32_t color;
+	struct ipaddr endpoint;
+	char name[SRTE_POLICY_NAME_MAX_LENGTH];
+	struct zapi_srte_tunnel segment_list;
+	int status;
+};
+
 struct zapi_pw {
 	char ifname[IF_NAMESIZE];
 	ifindex_t ifindex;
@@ -775,6 +804,14 @@ extern int tm_get_table_chunk(struct zclient *zclient, uint32_t chunk_size,
 extern int tm_release_table_chunk(struct zclient *zclient, uint32_t start,
 				  uint32_t end);
 
+extern int zebra_send_sr_policy(struct zclient *zclient, int cmd,
+				struct zapi_sr_policy *zp);
+extern int zapi_sr_policy_encode(struct stream *s, int cmd,
+				 struct zapi_sr_policy *zp);
+extern int zapi_sr_policy_decode(struct stream *s, struct zapi_sr_policy *zp);
+extern int zapi_sr_policy_notify_status_decode(struct stream *s,
+					       struct zapi_sr_policy *zp);
+
 extern int zebra_send_mpls_labels(struct zclient *zclient, int cmd,
 				  struct zapi_labels *zl);
 extern int zapi_labels_encode(struct stream *s, int cmd,
@@ -791,7 +828,7 @@ extern int zclient_send_rnh(struct zclient *zclient, int command,
 			    const struct prefix *p, bool exact_match,
 			    vrf_id_t vrf_id);
 int zapi_nexthop_encode(struct stream *s, const struct zapi_nexthop *api_nh,
-			uint32_t api_flags);
+			uint32_t api_flags, uint32_t api_message);
 extern int zapi_route_encode(uint8_t, struct stream *, struct zapi_route *);
 extern int zapi_route_decode(struct stream *, struct zapi_route *);
 bool zapi_route_notify_decode(struct stream *s, struct prefix *p,