isisd: make use of advanced concepts like arrays and loops

Have an array of spftrees instead of a separate spftree and an
spftree6 for which all the code gets duplicated.

Signed-off-by: Christian Franke <chris@opensourcerouting.org>

3 files changed, 57 insertions, 71 deletions

diff --git a/isisd/isis_spf.c b/isisd/isis_spf.c
index 13be8bac53..6c83f29257 100644
--- a/isisd/isis_spf.c
+++ b/isisd/isis_spf.c
@@ -508,67 +508,44 @@ static void isis_spftree_adj_del(struct isis_spftree *spftree,
 
 void spftree_area_init(struct isis_area *area)
 {
-	if (area->is_type & IS_LEVEL_1) {
-		if (area->spftree[0] == NULL)
-			area->spftree[0] = isis_spftree_new(area);
-		if (area->spftree6[0] == NULL)
-			area->spftree6[0] = isis_spftree_new(area);
-	}
+	for (int tree = SPFTREE_IPV4; tree < SPFTREE_COUNT; tree++) {
+		for (int level = ISIS_LEVEL1; level <= ISIS_LEVEL2; level++) {
+			if (!(area->is_type & level))
+				continue;
+			if (area->spftree[tree][level - 1])
+				continue;
 
-	if (area->is_type & IS_LEVEL_2) {
-		if (area->spftree[1] == NULL)
-			area->spftree[1] = isis_spftree_new(area);
-		if (area->spftree6[1] == NULL)
-			area->spftree6[1] = isis_spftree_new(area);
+			area->spftree[tree][level - 1] = isis_spftree_new(area);
+		}
 	}
-
-	return;
 }
 
 void spftree_area_del(struct isis_area *area)
 {
-	if (area->is_type & IS_LEVEL_1) {
-		if (area->spftree[0] != NULL) {
-			isis_spftree_del(area->spftree[0]);
-			area->spftree[0] = NULL;
-		}
-		if (area->spftree6[0]) {
-			isis_spftree_del(area->spftree6[0]);
-			area->spftree6[0] = NULL;
-		}
-	}
+	for (int tree = SPFTREE_IPV4; tree < SPFTREE_COUNT; tree++) {
+		for (int level = ISIS_LEVEL1; level <= ISIS_LEVEL2; level++) {
+			if (!(area->is_type & level))
+				continue;
+			if (!area->spftree[tree][level - 1])
+				continue;
 
-	if (area->is_type & IS_LEVEL_2) {
-		if (area->spftree[1] != NULL) {
-			isis_spftree_del(area->spftree[1]);
-			area->spftree[1] = NULL;
-		}
-		if (area->spftree6[1] != NULL) {
-			isis_spftree_del(area->spftree6[1]);
-			area->spftree6[1] = NULL;
+			isis_spftree_del(area->spftree[tree][level - 1]);
 		}
 	}
-
-	return;
 }
 
 void spftree_area_adj_del(struct isis_area *area, struct isis_adjacency *adj)
 {
-	if (area->is_type & IS_LEVEL_1) {
-		if (area->spftree[0] != NULL)
-			isis_spftree_adj_del(area->spftree[0], adj);
-		if (area->spftree6[0] != NULL)
-			isis_spftree_adj_del(area->spftree6[0], adj);
-	}
-
-	if (area->is_type & IS_LEVEL_2) {
-		if (area->spftree[1] != NULL)
-			isis_spftree_adj_del(area->spftree[1], adj);
-		if (area->spftree6[1] != NULL)
-			isis_spftree_adj_del(area->spftree6[1], adj);
+	for (int tree = SPFTREE_IPV4; tree < SPFTREE_COUNT; tree++) {
+		for (int level = ISIS_LEVEL1; level <= ISIS_LEVEL2; level++) {
+			if (!(area->is_type & level))
+				continue;
+			if (!area->spftree[tree][level - 1])
+				continue;
+			isis_spftree_adj_del(area->spftree[tree][level - 1],
+					     adj);
+		}
 	}
-
-	return;
 }
 
 /*
@@ -1274,9 +1251,9 @@ static int isis_run_spf(struct isis_area *area, int level, int family,
 	start_time = (start_time * 1000000) + nowtv->tv_usec;
 
 	if (family == AF_INET)
-		spftree = area->spftree[level - 1];
+		spftree = area->spftree[SPFTREE_IPV4][level - 1];
 	else if (family == AF_INET6)
-		spftree = area->spftree6[level - 1];
+		spftree = area->spftree[SPFTREE_IPV6][level - 1];
 	assert(spftree);
 	assert(sysid);
 
@@ -1417,7 +1394,7 @@ static struct isis_spf_run *isis_run_spf_arg(struct isis_area *area, int level)
 
 int isis_spf_schedule(struct isis_area *area, int level)
 {
-	struct isis_spftree *spftree = area->spftree[level - 1];
+	struct isis_spftree *spftree = area->spftree[SPFTREE_IPV4][level - 1];
 	time_t now = monotime(NULL);
 	int diff = now - spftree->last_run_monotime;
 
@@ -1569,23 +1546,23 @@ DEFUN (show_isis_topology,
 			if ((level & levels) == 0)
 				continue;
 
-			if (area->ip_circuits > 0 && area->spftree[level - 1]
-			    && isis_vertex_queue_count(&area->spftree[level - 1]->paths) > 0) {
+			if (area->ip_circuits > 0 && area->spftree[SPFTREE_IPV4][level - 1]
+			    && isis_vertex_queue_count(&area->spftree[SPFTREE_IPV4][level - 1]->paths) > 0) {
 				vty_out(vty,
 					"IS-IS paths to level-%d routers that speak IP\n",
 					level);
 				isis_print_paths(
-					vty, &area->spftree[level - 1]->paths,
+					vty, &area->spftree[SPFTREE_IPV4][level - 1]->paths,
 					isis->sysid);
 				vty_out(vty, "\n");
 			}
-			if (area->ipv6_circuits > 0 && area->spftree6[level - 1]
-			    && isis_vertex_queue_count(&area->spftree6[level - 1]->paths) > 0) {
+			if (area->ipv6_circuits > 0 && area->spftree[SPFTREE_IPV6][level - 1]
+			    && isis_vertex_queue_count(&area->spftree[SPFTREE_IPV6][level - 1]->paths) > 0) {
 				vty_out(vty,
 					"IS-IS paths to level-%d routers that speak IPv6\n",
 					level);
 				isis_print_paths(
-					vty, &area->spftree6[level - 1]->paths,
+					vty, &area->spftree[SPFTREE_IPV6][level - 1]->paths,
 					isis->sysid);
 				vty_out(vty, "\n");
 			}
diff --git a/isisd/isisd.c b/isisd/isisd.c
index 0094b30c28..ec71c224dd 100644
--- a/isisd/isisd.c
+++ b/isisd/isisd.c
@@ -1319,10 +1319,12 @@ DEFUN (show_isis_summary,
 			vty_out(vty, "\n");
 
 			vty_out(vty, "    IPv4 route computation:\n");
-			isis_spf_print(area->spftree[level - 1], vty);
+			isis_spf_print(area->spftree[SPFTREE_IPV4][level - 1],
+				       vty);
 
 			vty_out(vty, "    IPv6 route computation:\n");
-			isis_spf_print(area->spftree6[level - 1], vty);
+			isis_spf_print(area->spftree[SPFTREE_IPV6][level - 1],
+				       vty);
 		}
 	}
 	vty_out(vty, "\n");
@@ -1664,15 +1666,17 @@ void isis_area_invalidate_routes(struct isis_area *area, int levels)
 	for (int level = ISIS_LEVEL1; level <= ISIS_LEVEL2; level++) {
 		if (!(level & levels))
 			continue;
-		isis_spf_invalidate_routes(area->spftree[level - 1]);
-		isis_spf_invalidate_routes(area->spftree6[level - 1]);
+		for (int tree = SPFTREE_IPV4; tree < SPFTREE_COUNT; tree++) {
+			isis_spf_invalidate_routes(
+					area->spftree[tree][level - 1]);
+		}
 	}
 }
 
 void isis_area_verify_routes(struct isis_area *area)
 {
-	isis_spf_verify_routes(area, area->spftree);
-	isis_spf_verify_routes(area, area->spftree6);
+	for (int tree = SPFTREE_IPV4; tree < SPFTREE_COUNT; tree++)
+		isis_spf_verify_routes(area, area->spftree[tree]);
 }
 
 static void area_resign_level(struct isis_area *area, int level)
@@ -1684,14 +1688,14 @@ static void area_resign_level(struct isis_area *area, int level)
 		lsp_db_destroy(area->lspdb[level - 1]);
 		area->lspdb[level - 1] = NULL;
 	}
-	if (area->spftree[level - 1]) {
-		isis_spftree_del(area->spftree[level - 1]);
-		area->spftree[level - 1] = NULL;
-	}
-	if (area->spftree6[level - 1]) {
-		isis_spftree_del(area->spftree6[level - 1]);
-		area->spftree6[level - 1] = NULL;
+
+	for (int tree = SPFTREE_IPV4; tree < SPFTREE_COUNT; tree++) {
+		if (area->spftree[tree][level - 1]) {
+			isis_spftree_del(area->spftree[tree][level - 1]);
+			area->spftree[tree][level - 1] = NULL;
+		}
 	}
+
 	THREAD_TIMER_OFF(area->spf_timer[level - 1]);
 
 	sched_debug(
diff --git a/isisd/isisd.h b/isisd/isisd.h
index c1bf6bc976..fef18ed6fc 100644
--- a/isisd/isisd.h
+++ b/isisd/isisd.h
@@ -63,11 +63,16 @@ struct isis {
 extern struct isis *isis;
 DECLARE_QOBJ_TYPE(isis_area)
 
+enum spf_tree_id {
+	SPFTREE_IPV4 = 0,
+	SPFTREE_IPV6,
+	SPFTREE_COUNT
+};
+
 struct isis_area {
 	struct isis *isis;			       /* back pointer */
 	dict_t *lspdb[ISIS_LEVELS];		       /* link-state dbs */
-	struct isis_spftree *spftree[ISIS_LEVELS];     /* The v4 SPTs */
-	struct isis_spftree *spftree6[ISIS_LEVELS];    /* The v6 SPTs */
+	struct isis_spftree *spftree[SPFTREE_COUNT][ISIS_LEVELS];
 #define DEFAULT_LSP_MTU 1497
 	unsigned int lsp_mtu;      /* Size of LSPs to generate */
 	struct list *circuit_list; /* IS-IS circuits */