isisd: Add func to build Sub-TLV from SRv6 End SID

Add a function to build an SRv6 End SID TLV (RFC 9352 section sonic-net#7.2) to advertise a specific SRv6 End SID passed as an argument. Signed-off-by: Carmine Scarpitta <[email protected]>
marcosfsch · Sep 11, 2023 · 1804d70 · 1804d70
1 parent 2aaa75a
commit 1804d70
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Showing 2 changed files with 37 additions and 0 deletions.
diff --git a/isisd/isis_tlvs.c b/isisd/isis_tlvs.c
@@ -7732,6 +7732,40 @@ void isis_tlvs_set_purge_originator(struct isis_tlvs *tlvs,
 	}
 }
 
+/* Add an SRv6 End SID to the SRv6 End SID Sub-TLV */
+void isis_subtlvs_add_srv6_end_sid(struct isis_subtlvs *subtlvs,
+				   struct isis_srv6_sid *sid)
+{
+	struct isis_srv6_end_sid_subtlv *sid_subtlv;
+
+	if (!sid)
+		return;
+
+	/* The SRv6 End SID Sub-TLV advertises SRv6 SIDs with Endpoint behaviors
+	 * that do not require a particular neighbor in order to be correctly
+	 * applied (e.g. End, End.DT6, ...). Before proceeding, let's make sure
+	 * we are encoding one of the supported behaviors. */
+	if (sid->behavior != SRV6_ENDPOINT_BEHAVIOR_END &&
+	    sid->behavior != SRV6_ENDPOINT_BEHAVIOR_END_NEXT_CSID &&
+	    sid->behavior != SRV6_ENDPOINT_BEHAVIOR_END_DT6 &&
+	    sid->behavior != SRV6_ENDPOINT_BEHAVIOR_END_DT6_USID &&
+	    sid->behavior != SRV6_ENDPOINT_BEHAVIOR_END_DT4 &&
+	    sid->behavior != SRV6_ENDPOINT_BEHAVIOR_END_DT4_USID &&
+	    sid->behavior != SRV6_ENDPOINT_BEHAVIOR_END_DT46 &&
+	    sid->behavior != SRV6_ENDPOINT_BEHAVIOR_END_DT46_USID)
+		return;
+
+	/* Allocate memory for the Sub-TLV */
+	sid_subtlv = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(*sid_subtlv));
+
+	/* Fill in the SRv6 End SID Sub-TLV according to the SRv6 SID
+	 * configuration */
+	isis_srv6_end_sid2subtlv(sid, sid_subtlv);
+
+	/* Append the SRv6 End SID Sub-TLV to the Sub-TLVs list */
+	append_item(&subtlvs->srv6_end_sids, (struct isis_item *)sid_subtlv);
+}
+
 /* Add an SRv6 Locator to the SRv6 Locator TLV */
 void isis_tlvs_add_srv6_locator(struct isis_tlvs *tlvs, uint16_t mtid,
 				struct isis_srv6_locator *loc)

diff --git a/isisd/isis_tlvs.h b/isisd/isis_tlvs.h
@@ -22,6 +22,7 @@ DECLARE_MTYPE(ISIS_SUBTLV);
 
 struct lspdb_head;
 struct sr_prefix_cfg;
+struct isis_srv6_sid;
 struct isis_srv6_locator;
 
 struct isis_area_address {
@@ -834,6 +835,8 @@ void isis_tlvs_set_purge_originator(struct isis_tlvs *tlvs,
 				    const uint8_t *generator,
 				    const uint8_t *sender);
 
+void isis_subtlvs_add_srv6_end_sid(struct isis_subtlvs *subtlvs,
+				   struct isis_srv6_sid *sid);
 void isis_tlvs_add_srv6_locator(struct isis_tlvs *tlvs, uint16_t mtid,
 				struct isis_srv6_locator *loc);
 #endif