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, 39 insertions, 4 deletions

diff --git a/zebra/zebra_mpls.c b/zebra/zebra_mpls.c
index 1ac7bc7a2a..a30cea6a1e 100644
--- a/zebra/zebra_mpls.c
+++ b/zebra/zebra_mpls.c
@@ -47,6 +47,7 @@
 #include "zebra/zebra_memory.h"
 #include "zebra/zebra_vrf.h"
 #include "zebra/zebra_mpls.h"
+#include "zebra/zebra_srte.h"
 #include "zebra/zebra_errors.h"
 
 DEFINE_MTYPE_STATIC(ZEBRA, LSP, "MPLS LSP object")
@@ -1505,6 +1506,7 @@ static json_object *nhlfe_json(zebra_nhlfe_t *nhlfe)
 	char buf[BUFSIZ];
 	json_object *json_nhlfe = NULL;
 	json_object *json_backups = NULL;
+	json_object *json_label_stack;
 	struct nexthop *nexthop = nhlfe->nexthop;
 	int i;
 
@@ -1512,6 +1514,14 @@ static json_object *nhlfe_json(zebra_nhlfe_t *nhlfe)
 	json_object_string_add(json_nhlfe, "type", nhlfe_type2str(nhlfe->type));
 	json_object_int_add(json_nhlfe, "outLabel",
 			    nexthop->nh_label->label[0]);
+
+	json_label_stack = json_object_new_array();
+	json_object_object_add(json_nhlfe, "outLabelStack", json_label_stack);
+	for (i = 0; i < nexthop->nh_label->num_labels; i++)
+		json_object_array_add(
+			json_label_stack,
+			json_object_new_int(nexthop->nh_label->label[i]));
+
 	json_object_int_add(json_nhlfe, "distance", nhlfe->distance);
 
 	if (CHECK_FLAG(nhlfe->flags, NHLFE_FLAG_INSTALLED))
@@ -1916,14 +1926,13 @@ static int mpls_processq_init(void)
 }
 
 
-/* Public functions */
-
 /*
  * Process LSP update results from zebra dataplane.
  */
 void zebra_mpls_lsp_dplane_result(struct zebra_dplane_ctx *ctx)
 {
 	struct zebra_vrf *zvrf;
+	mpls_label_t label;
 	zebra_ile_t tmp_ile;
 	struct hash *lsp_table;
 	zebra_lsp_t *lsp;
@@ -1931,6 +1940,7 @@ void zebra_mpls_lsp_dplane_result(struct zebra_dplane_ctx *ctx)
 	struct nexthop *nexthop;
 	enum dplane_op_e op;
 	enum zebra_dplane_result status;
+	enum zebra_sr_policy_update_label_mode update_mode;
 
 	op = dplane_ctx_get_op(ctx);
 	status = dplane_ctx_get_status(ctx);
@@ -1941,6 +1951,8 @@ void zebra_mpls_lsp_dplane_result(struct zebra_dplane_ctx *ctx)
 			   dplane_ctx_get_in_label(ctx),
 			   dplane_res2str(status));
 
+	label = dplane_ctx_get_in_label(ctx);
+
 	switch (op) {
 	case DPLANE_OP_LSP_INSTALL:
 	case DPLANE_OP_LSP_UPDATE:
@@ -1951,7 +1963,7 @@ void zebra_mpls_lsp_dplane_result(struct zebra_dplane_ctx *ctx)
 
 		lsp_table = zvrf->lsp_table;
 
-		tmp_ile.in_label = dplane_ctx_get_in_label(ctx);
+		tmp_ile.in_label = label;
 		lsp = hash_lookup(lsp_table, &tmp_ile);
 		if (lsp == NULL) {
 			if (IS_ZEBRA_DEBUG_DPLANE)
@@ -1985,13 +1997,21 @@ void zebra_mpls_lsp_dplane_result(struct zebra_dplane_ctx *ctx)
 			}
 		}
 
+		update_mode = (op == DPLANE_OP_LSP_INSTALL)
+				      ? ZEBRA_SR_POLICY_LABEL_CREATED
+				      : ZEBRA_SR_POLICY_LABEL_UPDATED;
+		zebra_sr_policy_label_update(label, update_mode);
 		break;
 
 	case DPLANE_OP_LSP_DELETE:
-		if (status != ZEBRA_DPLANE_REQUEST_SUCCESS)
+		if (status != ZEBRA_DPLANE_REQUEST_SUCCESS) {
 			flog_warn(EC_ZEBRA_LSP_DELETE_FAILURE,
 				  "LSP Deletion Failure: in-label %u",
 				  dplane_ctx_get_in_label(ctx));
+			break;
+		}
+		zebra_sr_policy_label_update(label,
+					     ZEBRA_SR_POLICY_LABEL_REMOVED);
 		break;
 
 	default:
@@ -3419,6 +3439,21 @@ static int lsp_backup_znh_install(zebra_lsp_t *lsp, enum lsp_types_t type,
 	return 0;
 }
 
+zebra_lsp_t *mpls_lsp_find(struct zebra_vrf *zvrf, mpls_label_t in_label)
+{
+	struct hash *lsp_table;
+	zebra_ile_t tmp_ile;
+
+	/* Lookup table. */
+	lsp_table = zvrf->lsp_table;
+	if (!lsp_table)
+		return NULL;
+
+	/* If entry is not present, exit. */
+	tmp_ile.in_label = in_label;
+	return hash_lookup(lsp_table, &tmp_ile);
+}
+
 /*
  * Uninstall a particular NHLFE in the forwarding table. If this is
  * the only NHLFE, the entire LSP forwarding entry has to be deleted.