From: Carmine Scarpitta <carmine.scarpitta@uniroma2.it>
Date: Wed, 22 Feb 2023 10:20:50 +0000 (+0100)
Subject: isisd: Install SRv6 End SID automatically
X-Git-Tag: base_9.1~88^2~98
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=58d85ce9657e991c9372605268bc15c09d69fcc6;p=mirror%2Ffrr.git

isisd: Install SRv6 End SID automatically

When zebra assigns a chunk to IS-IS, zebra sends a
ZEBRA_SRV6_MANAGER_GET_LOCATOR_CHUNK notification to IS-IS.
IS-IS invokes the `isis_zebra_process_srv6_locator_chunk()` callback to
process the received notification.

Actually, `isis_zebra_process_srv6_locator_chunk()` iterates over all
areas of the current IS-IS instance and looks for an area for which the
received chunk was requested.
If a match is found, the new chunk is added to the area's chunk list and
`lsp_regenerate_schedule()` is called to regenerate the LSPs to
advertise the new SRv6 locator.

This commit extends the `isis_zebra_process_srv6_locator_chunk()`
function to automatically allocate an SRv6 End SID from the received
chunk and install it in the data plane.

The SRv6 End SID is the instantiation of a Prefix-SID (RFC 8986 section

Signed-off-by: Carmine Scarpitta <carmine.scarpitta@uniroma2.it>
---

diff --git a/isisd/isis_zebra.c b/isisd/isis_zebra.c
index aecf7f6e69..de31a2d19a 100644
--- a/isisd/isis_zebra.c
+++ b/isisd/isis_zebra.c
@@ -1024,6 +1024,8 @@ static int isis_zebra_process_srv6_locator_chunk(ZAPI_CALLBACK_ARGS)
 	struct isis_area *area;
 	struct srv6_locator_chunk *c;
 	struct srv6_locator_chunk *chunk = srv6_locator_chunk_alloc();
+	struct isis_srv6_sid *sid;
+	enum srv6_endpoint_behavior_codepoint behavior;
 	bool allocated = false;
 
 	/* Decode the received zebra message */
@@ -1060,7 +1062,25 @@ static int isis_zebra_process_srv6_locator_chunk(ZAPI_CALLBACK_ARGS)
 		/* Add the SRv6 Locator chunk to the per-area chunks list */
 		listnode_add(area->srv6db.srv6_locator_chunks, chunk);
 
-		/* Regenerate LSPs to advertise the new locator */
+		/* Decide which behavior to use,depending on the locator type
+		 * (i.e. uSID vs classic locator) */
+		behavior = (CHECK_FLAG(chunk->flags, SRV6_LOCATOR_USID))
+				   ? SRV6_ENDPOINT_BEHAVIOR_END_NEXT_CSID
+				   : SRV6_ENDPOINT_BEHAVIOR_END;
+
+		/* Allocate new SRv6 End SID */
+		sid = isis_srv6_sid_alloc(area, chunk, behavior, 0);
+		if (!sid)
+			return -1;
+
+		/* Install the new SRv6 End SID in the forwarding plane through
+		 * Zebra */
+		isis_zebra_srv6_sid_install(area, sid);
+
+		/* Store the SID */
+		listnode_add(area->srv6db.srv6_sids, sid);
+
+		/* Regenerate LSPs to advertise the new locator and the SID */
 		lsp_regenerate_schedule(area, area->is_type, 0);
 
 		allocated = true;