isisd: When the metric-type is configured as "wide", the IS-IS genera…

…tes incorrect metric values for IPv4 directly connected routes.

The IPv4 directly connected route prefix exists in both the root LSP and the root's neighbor LSP:

1. When generating vertices for directly connected route prefixes with a metric of 0 based on the root LSP, the isis_spf_preload_tent_ip_reach_cb function only generates vertices of type VTYPE_IPREACH_INTERNAL without distinguishing between area->oldmetric and area->newmetric.
2. When generating vertices for the directly connected route prefix based on the neighbor LSP, the isis_spf_process_lsp function will generate vertices of type VTYPE_IPREACH_INTERNAL and VTYPE_IPREACH_TE based on area->oldmetric and area->newmetric, where the vertex metric is the sum of the metric from the root IS to the neighbor IS and from the neighbor IS to the root IS, respectively.

If area->newmetric=1, the same directly connected route prefix will have both VTYPE_IPREACH_INTERNAL vertices with a metric of 0 and VTYPE_IPREACH_TE vertices with a non-zero metric. During route generation, the isis_spf_loop function will prioritize selecting VTYPE_IPREACH_TE vertices, leading to incorrect metrics for the directly connected routes.

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>

fix frrbot styling issues found.

1）fix frrbot styling issues found.
2）Roll back the modifications to TE.

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>

Maintain code factorization and avoid duplicating code.

Maintain code factorization and avoid duplicating code.

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>

isisd: fix frrbot styling issues found

fix frrbot styling issues found

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>

isisd: fix frrbot styling issues found

fix frrbot styling issues found

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>

isisd: Resolve compilation issues.

Resolve compilation issues.

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>

isisd: Resolve compilation issues.

Resolve compilation issues.

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>

isisd: fix frrbot styling issues found

fix frrbot styling issues found

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>

isisd: fix frrbot styling issues found

fix frrbot styling issues found

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>

isisd: Resolve compilation issues.

Resolve compilation issues.

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>

isisd/isis_spf.c

@@ -1260,7 +1260,7 @@ static int isis_spf_preload_tent_ip_reach_cb(const struct prefix *prefix,
 	struct isis_vertex *parent = args->parent;
 	struct prefix_pair ip_info;
 	enum vertextype vtype;
-	bool has_valid_psid = false;
+	bool has_valid_psid = false, transition = false;
 
 	if (external)
 		return LSP_ITER_CONTINUE;
@@ -1270,10 +1270,17 @@ static int isis_spf_preload_tent_ip_reach_cb(const struct prefix *prefix,
 	prefix_copy(&ip_info.dest, prefix);
 	apply_mask(&ip_info.dest);
 
-	if (prefix->family == AF_INET)
+	if (prefix->family == AF_INET) {
 		vtype = VTYPE_IPREACH_INTERNAL;
-	else
+
+		if (spftree->area->newmetric)
+			vtype = VTYPE_IPREACH_TE;
+
+		if (spftree->area->oldmetric && spftree->area->newmetric)
+			transition = true;
+	} else {
 		vtype = VTYPE_IP6REACH_INTERNAL;
+	}
 
 	/* Parse list of Prefix-SID subTLVs if SR is enabled */
 	if (spftree->area->srdb.enabled && subtlvs) {
@@ -1288,6 +1295,11 @@ static int isis_spf_preload_tent_ip_reach_cb(const struct prefix *prefix,
 			has_valid_psid = true;
 			isis_spf_add_local(spftree, vtype, &ip_info, NULL, 0,
 					   psid, parent);
+			if (transition)
+				isis_spf_add_local(spftree,
+						   VTYPE_IPREACH_INTERNAL,
+						   &ip_info, NULL, 0, psid,
+						   parent);
 
 			/*
 			 * Stop the Prefix-SID iteration since we only support
@@ -1296,9 +1308,13 @@ static int isis_spf_preload_tent_ip_reach_cb(const struct prefix *prefix,
 			break;
 		}
 	}
-	if (!has_valid_psid)
+	if (!has_valid_psid) {
 		isis_spf_add_local(spftree, vtype, &ip_info, NULL, 0, NULL,
 				   parent);
+		if (transition)
+			isis_spf_add_local(spftree, VTYPE_IPREACH_INTERNAL,
+					   &ip_info, NULL, 0, NULL, parent);
+	}
 
 	return LSP_ITER_CONTINUE;
 }