isisd: add isis flex-algo lsp advertisement

Deal with the packing and unpacking of following Flex-Algo
(Sub-)-Sub-TLVs:

- Router Capability (already defined TLV 242)
	- List of the Flex-Algo Definitions (Sub-TLV 26)
		- Exclude admin group (Sub-Sub-TLV 1)
                - Include-any admin group (Sub-Sub-TLV 2)
                - Include-all admin group (Sub-Sub-TLV 3)
                - Flags (for prefix-metric) (Sub-Sub-TLV 4)
- Extended IS Reachability (already defined TLV 22)
	- Application-Specific Link Attributes (Sub-TLV 16)
	  (to enable the Flex-Algo flag on a link)
		- Admin-group (Sub-Sub-TLV 3)
		- Extended Admin-group (Sub-Sub-TLV 14)

Not that:

- Admin-group deals with affinities.
- List of SR Algorithm (Sub-TLV 19) within Router Capability (TLV 242)
  are already set in a previous commit.

Signed-off-by: Hiroki Shirokura <hiroki.shirokura@linecorp.com>
Signed-off-by: Eric Kinzie <ekinzie@labn.net>
Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>

isisd/isis_lsp.c

@@ -59,6 +59,7 @@
 #include "isisd/fabricd.h"
 #include "isisd/isis_tx_queue.h"
 #include "isisd/isis_nb.h"
+#include "isisd/isis_flex_algo.h"
 
 DEFINE_MTYPE_STATIC(ISISD, ISIS_LSP, "ISIS LSP");
 
@@ -1067,6 +1068,8 @@ static void lsp_build(struct isis_lsp *lsp, struct isis_area *area)
 	/* Add Router Capability TLV. */
 	if (area->isis->router_id != 0) {
 		struct isis_router_cap cap = {};
+		struct listnode *node;
+		struct flex_algo *fa;
 
 		/* init SR algo list content to the default value */
 		for (int i = 0; i < SR_ALGORITHM_COUNT; i++)
@@ -1089,6 +1092,12 @@ static void lsp_build(struct isis_lsp *lsp, struct isis_area *area)
 			/* Then Algorithm */
 			cap.algo[0] = SR_ALGORITHM_SPF;
 			cap.algo[1] = SR_ALGORITHM_UNSET;
+			for (ALL_LIST_ELEMENTS_RO(area->flex_algos->flex_algos,
+						  node, fa)) {
+				lsp_debug("ISIS (%s):   SR Algorithm %u",
+					  area->area_tag, fa->algorithm);
+				cap.algo[fa->algorithm] = fa->algorithm;
+			}
 			/* SRLB */
 			cap.srlb.flags = 0;
 			range_size = srdb->config.srlb_upper_bound
@@ -1100,8 +1109,16 @@ static void lsp_build(struct isis_lsp *lsp, struct isis_area *area)
 		}
 
 		isis_tlvs_set_router_capability(lsp->tlvs, &cap);
-		lsp_debug("ISIS (%s): Adding Router Capabilities information",
-			  area->area_tag);
+
+		for (ALL_LIST_ELEMENTS_RO(area->flex_algos->flex_algos, node,
+					  fa)) {
+			if (!fa->advertise_definition)
+				continue;
+			lsp_debug("ISIS (%s):   Flex-Algo Definition %u",
+				  area->area_tag, fa->algorithm);
+			isis_tlvs_set_router_capability_fad(area, lsp->tlvs,
+							    fa);
+		}
 	}
 
 	/* IPv4 address and TE router ID TLVs.
@@ -1246,6 +1263,9 @@ static void lsp_build(struct isis_lsp *lsp, struct isis_area *area)
 			}
 		}
 
+		/* ASLA for Flex-Algo */
+		isis_tlvs_add_asla_admin_group(circuit);
+
 		switch (circuit->circ_type) {
 		case CIRCUIT_T_BROADCAST:
 			if (level & circuit->is_type) {