add support for TLV 22 SubTLV 31 Adjacency SID generation, SID values…

… randomized between 256-4096
rtbrick · Aug 28, 2024 · a18f59e · a18f59e
1 parent 6b6e125
commit a18f59e
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Showing 6 changed files with 44 additions and 14 deletions.
diff --git a/code/bngblaster/src/bbl_config.c b/code/bngblaster/src/bbl_config.c
@@ -1541,7 +1541,8 @@ json_parse_isis_config(json_t *isis, isis_config_s *isis_config)
         "hostname", "router-id", "system-id",
         "area", "sr-base", "sr-range",
         "sr-node-sid", "teardown-time", "external",
-        "external-auto-refresh", "lsp-buffer-size", "sr-algo"
+        "external-auto-refresh", "lsp-buffer-size", "sr-algo",
+        "adjacency-sid"
     };
     if(!schema_validate(isis, "isis", schema, 
     sizeof(schema)/sizeof(schema[0]))) {
@@ -1798,6 +1799,13 @@ json_parse_isis_config(json_t *isis, isis_config_s *isis_config)
         isis_config->sr_algo_count = 0;
     }
 
+    JSON_OBJ_GET_BOOL(isis, value, "isis", "adjacency-sid");
+    if(value) {
+        isis_config->adjacency_sid  = json_boolean_value(value);
+    } else {
+        isis_config->adjacency_sid  = false;
+    }
+
     value = json_object_get(isis, "teardown-time");
     JSON_OBJ_GET_NUMBER(isis, value, "isis", "teardown-time", 0, 65535);
     if(value) {

diff --git a/code/bngblaster/src/isis/isis_def.h b/code/bngblaster/src/isis/isis_def.h
@@ -253,6 +253,7 @@ typedef struct isis_config_ {
     uint32_t            sr_node_sid;
     uint8_t            *sr_algo;
     uint8_t             sr_algo_count;
+    bool                adjacency_sid;
 
     /* External */
     bool external_purge;

diff --git a/code/bngblaster/src/isis/isis_lsp.c b/code/bngblaster/src/isis/isis_lsp.c
@@ -639,12 +639,12 @@ isis_lsp_self_dis(isis_adjacency_s *adjacency)
     if(!lsp) return;
     pdu = &lsp->pdu;
 
-    isis_pdu_add_tlv_ext_reachability(pdu, config->system_id, 0, 0);
+    isis_pdu_add_tlv_ext_reachability(pdu, config->system_id, 0, 0, config->adjacency_sid);
 
     peer = adjacency->peer;
     while(peer) {
         if(peer->state == ISIS_PEER_STATE_UP && ISIS_PDU_REMAINING(pdu) >= 13) {
-            isis_pdu_add_tlv_ext_reachability(pdu, peer->system_id, 0, 0);
+            isis_pdu_add_tlv_ext_reachability(pdu, peer->system_id, 0, 0, config->adjacency_sid);
         }
         peer = peer->next;
     }
@@ -739,20 +739,20 @@ isis_lsp_self_update(isis_instance_s *instance, uint8_t level)
         if(adjacency->p2p) {
             isis_pdu_add_tlv_ext_reachability(pdu, 
                 adjacency->peer->system_id, 0,
-                adjacency->metric);
+                adjacency->metric, config->adjacency_sid);
         } else {
             if(adjacency->dis) {
                 isis_pdu_add_tlv_ext_reachability(pdu, 
                     adjacency->dis->system_id, 
                     adjacency->dis->pseudo_node_id,
-                    adjacency->metric);
+                    adjacency->metric, config->adjacency_sid);
 
                 isis_lsp_self_dis_purge(adjacency);
             } else {
                 isis_pdu_add_tlv_ext_reachability(pdu, 
                     config->system_id,
                     adjacency->pseudo_node_id,
-                    adjacency->metric);
+                    adjacency->metric, config->adjacency_sid);
 
                 isis_lsp_self_dis(adjacency);
             }
@@ -775,7 +775,7 @@ isis_lsp_self_update(isis_instance_s *instance, uint8_t level)
 
         isis_pdu_add_tlv_ext_reachability(pdu, 
             external_connection->system_id, 0,
-            external_connection->level[level-1].metric);
+            external_connection->level[level-1].metric, config->adjacency_sid);
         external_connection = external_connection->next;
     }
 

diff --git a/code/bngblaster/src/isis/isis_pdu.c b/code/bngblaster/src/isis/isis_pdu.c
@@ -567,18 +567,36 @@ isis_pdu_add_tlv_auth(isis_pdu_s *pdu, isis_auth_type auth, char *key)
 void
 isis_pdu_add_tlv_ext_reachability(isis_pdu_s *pdu, uint8_t *system_id, 
                                   uint8_t pseudo_node, 
-                                  uint32_t metric)
+                                  uint32_t metric, bool adjacency_sid)
 {
     isis_tlv_s *tlv = (isis_tlv_s *)ISIS_PDU_CURSOR(pdu);
     uint8_t *tlv_cur = tlv->value;
     tlv->type = ISIS_TLV_EXT_REACHABILITY;
-    tlv->len = 11;
+    if(adjacency_sid && pseudo_node == 0) {
+        tlv->len = 18;
+    } else {
+	tlv->len = 11;
+    }
     memcpy(tlv_cur, system_id, ISIS_SYSTEM_ID_LEN);
     tlv_cur += ISIS_SYSTEM_ID_LEN; 
     *(uint32_t*)tlv_cur = htobe32(metric);
     *tlv_cur = pseudo_node;
     tlv_cur += sizeof(metric);
-    *tlv_cur = 0; 
+    /* implementation only for SubTLV 31 (non-DIS case), TODO for SubTLV 32 */
+    if(adjacency_sid && pseudo_node == 0) {
+	 *tlv_cur = 7;
+	 tlv_cur += sizeof(uint8_t);
+	 *tlv_cur++ = 31;
+	 *tlv_cur++ = 5;
+	 /* set V and L flag always */
+	 *tlv_cur++ = 0x30;
+	 *tlv_cur++ = 0;
+	 /* generate random adjacency SID but avoid reserved ranges 0-255 */
+	 *tlv_cur++ = 0;
+	 *(uint16_t*)tlv_cur = htobe16(rand() % 4096 + 256);
+    } else {
+	 *tlv_cur = 0;
+    }
     ISIS_PDU_BUMP_WRITE_BUFFER(pdu, sizeof(isis_tlv_s)+tlv->len);
 }
 
@@ -597,20 +615,20 @@ isis_pdu_add_tlv_router_cap(isis_pdu_s *pdu, ipv4addr_t router_id,
         tlv->len = 16;
     }
     *(ipv4addr_t*)tlv_cur = router_id;
-    tlv_cur+=sizeof(ipv4addr_t);
+    tlv_cur += sizeof(ipv4addr_t);
     *tlv_cur++ = 0;
     *tlv_cur++ = 2;
     *tlv_cur++ = 9;
     *(uint32_t*)tlv_cur = htobe32(sr_range);
     *tlv_cur = 0;
     if(ipv4) *tlv_cur |= 128;
     if(ipv6) *tlv_cur |= 64;
-    tlv_cur+=sizeof(uint32_t);
+    tlv_cur += sizeof(uint32_t);
     *tlv_cur++ = 1;
     *(uint32_t*)tlv_cur = htobe32(sr_base);
     *tlv_cur = 3;
     if(sr_algo_count > 0) {
-	tlv_cur+=sizeof(uint32_t);
+	tlv_cur += sizeof(uint32_t);
         *tlv_cur++ = 19;
         *tlv_cur++ = sr_algo_count;
         for(int i = 0; i < sr_algo_count; i++) {

diff --git a/code/bngblaster/src/isis/isis_pdu.h b/code/bngblaster/src/isis/isis_pdu.h
@@ -107,7 +107,7 @@ void
 isis_pdu_add_tlv_auth(isis_pdu_s *pdu, isis_auth_type auth, char *key);
 
 void
-isis_pdu_add_tlv_ext_reachability(isis_pdu_s *pdu, uint8_t *system_id, uint8_t pseudo_node, uint32_t metric);
+isis_pdu_add_tlv_ext_reachability(isis_pdu_s *pdu, uint8_t *system_id, uint8_t pseudo_node, uint32_t metric, bool adjacency_sid);
 
 void
 isis_pdu_add_tlv_router_cap(isis_pdu_s *pdu, ipv4addr_t router_id, 

diff --git a/docsrc/sources/configuration/isis.rst b/docsrc/sources/configuration/isis.rst
@@ -90,6 +90,9 @@
 | **sr-node-sid**                  | | ISIS SR node SID.                                               |
 |                                  | | Default: 0 Range: 0 - 1048575                                   |
 +----------------------------------+-------------------------------------------------------------------+
+| **adjacency-sid**                | | Enable/disable Adjacency SID generation.                        |
+|                                  | | Default: false                                                  |
++----------------------------------+-------------------------------------------------------------------+
 | **teardown-time**                | | ISIS teardown time in seconds.                                  |
 |                                  | | Default: 5 Range: 0 - 65535                                     |
 +----------------------------------+-------------------------------------------------------------------+