bgpd, zebra: auto assign labels from label pool to regular prefixes in BGP labeled...

[mirror_frr.git] / zebra / zebra_mpls.c

diff --git a/zebra/zebra_mpls.c b/zebra/zebra_mpls.c
index 5fe01161586c76fbd44b4a697aed718c26009d76..c0764cd4b8c6090226be791dac19a3d0af8ff7dc 100644 (file)
--- a/zebra/zebra_mpls.c
+++ b/zebra/zebra_mpls.c
@@ -1813,17 +1813,22 @@ int zebra_mpls_lsp_uninstall(struct zebra_vrf *zvrf, struct route_node *rn,
  * NOTE: If there is a manually configured label binding, that is used.
  * Otherwise, if a label index is specified, it means we have to allocate the
  * label from a locally configured label block (SRGB), if one exists and index
- * is acceptable.
+ * is acceptable. If no label index then just register the specified label.
+ * NOTE2: Either label or label_index is expected to be set to MPLS_INVALID_*
+ * by the calling function. Register requests with both will be rejected.
  */
 int zebra_mpls_fec_register(struct zebra_vrf *zvrf, struct prefix *p,
-                           uint32_t label_index, struct zserv *client)
+                           uint32_t label, uint32_t label_index,
+                           struct zserv *client)
 {
        struct route_table *table;
        zebra_fec_t *fec;
        char buf[BUFSIZ];
-       int new_client;
-       int label_change = 0;
+       bool new_client;
+       bool label_change = false;
        uint32_t old_label;
+       bool have_label_index = (label_index != MPLS_INVALID_LABEL_INDEX);
+       bool is_configured_fec = false; /* indicate statically configured FEC */
 
        table = zvrf->fec_table[family2afi(PREFIX_FAMILY(p))];
        if (!table)
@@ -1832,12 +1837,20 @@ int zebra_mpls_fec_register(struct zebra_vrf *zvrf, struct prefix *p,
        if (IS_ZEBRA_DEBUG_MPLS)
                prefix2str(p, buf, BUFSIZ);
 
+       if (label != MPLS_INVALID_LABEL && have_label_index) {
+               flog_err(
+                       EC_ZEBRA_FEC_LABEL_INDEX_LABEL_CONFLICT,
+                       "Rejecting FEC register for %s with both label %u and Label Index %u specified, client %s",
+                       buf, label, label_index,
+                       zebra_route_string(client->proto));
+               return -1;
+       }
+
        /* Locate FEC */
        fec = fec_find(table, p);
        if (!fec) {
-               fec = fec_add(table, p, MPLS_INVALID_LABEL, 0, label_index);
+               fec = fec_add(table, p, label, 0, label_index);
                if (!fec) {
-                       prefix2str(p, buf, BUFSIZ);
                        flog_err(
                                EC_ZEBRA_FEC_ADD_FAILED,
                                "Failed to add FEC %s upon register, client %s",
@@ -1846,16 +1859,19 @@ int zebra_mpls_fec_register(struct zebra_vrf *zvrf, struct prefix *p,
                }
 
                old_label = MPLS_INVALID_LABEL;
-               new_client = 1;
+               new_client = true;
        } else {
+               /* Check if the FEC has been statically defined in the config */
+               is_configured_fec = fec->flags & FEC_FLAG_CONFIGURED;
                /* Client may register same FEC with different label index. */
                new_client =
                        (listnode_lookup(fec->client_list, client) == NULL);
-               if (!new_client && fec->label_index == label_index)
+               if (!new_client && fec->label_index == label_index
+                   && fec->label == label)
                        /* Duplicate register */
                        return 0;
 
-               /* Save current label, update label index */
+               /* Save current label, update the FEC */
                old_label = fec->label;
                fec->label_index = label_index;
        }
@@ -1864,21 +1880,29 @@ int zebra_mpls_fec_register(struct zebra_vrf *zvrf, struct prefix *p,
                listnode_add(fec->client_list, client);
 
        if (IS_ZEBRA_DEBUG_MPLS)
-               zlog_debug("FEC %s Label Index %u %s by client %s", buf,
-                          label_index, new_client ? "registered" : "updated",
-                          zebra_route_string(client->proto));
-
-       /* If not a configured FEC, derive the local label (from label index)
-        * or reset it.
+               zlog_debug("FEC %s label%s %u %s by client %s%s", buf,
+                          have_label_index ? " index" : "",
+                          have_label_index ? label_index : label,
+                          new_client ? "registered" : "updated",
+                          zebra_route_string(client->proto),
+                          is_configured_fec
+                                  ? ", but using statically configured label"
+                                  : "");
+
+       /* If not a statically configured FEC, derive the local label
+        * from label index or use the provided label
         */
-       if (!(fec->flags & FEC_FLAG_CONFIGURED)) {
-               fec_derive_label_from_index(zvrf, fec);
+       if (!is_configured_fec) {
+               if (have_label_index)
+                       fec_derive_label_from_index(zvrf, fec);
+               else
+                       fec->label = label;
 
                /* If no label change, exit. */
                if (fec->label == old_label)
                        return 0;
 
-               label_change = 1;
+               label_change = true;
        }
 
        /* If new client or label change, update client and install or uninstall
@@ -2106,8 +2130,8 @@ int zebra_mpls_static_fec_del(struct zebra_vrf *zvrf, struct prefix *p)
 
        if (IS_ZEBRA_DEBUG_MPLS) {
                prefix2str(p, buf, BUFSIZ);
-               zlog_debug("Delete fec %s label index %u", buf,
-                          fec->label_index);
+               zlog_debug("Delete fec %s label %u label index %u", buf,
+                          fec->label, fec->label_index);
        }
 
        old_label = fec->label;