[PATCH dpdk 2/2] rib: add mode to include top-level route in traversal

[Robin Jarry]

rte_rib_get_nxt() and rte_rib6_get_nxt() skip the exact match
top-level route when iterating subroutes. This is the expected behavior
in most cases but some users need the full subtree including the root.

Add a RTE_RIB_GET_NXT_ALL_TOP (and RTE_RIB6_GET_NXT_ALL_TOP) mode
that uses >= instead of > when comparing depths so that the top-level
route is returned as well.

Signed-off-by: Robin Jarry <rjarry at redhat.com>
---
 app/test/test_rib.c  | 16 ++++++++++++++++
 app/test/test_rib6.c | 16 ++++++++++++++++
 lib/rib/rte_rib.c    | 12 ++++++++++--
 lib/rib/rte_rib.h    |  4 ++++
 lib/rib/rte_rib6.c   | 12 ++++++++++--
 lib/rib/rte_rib6.h   |  4 ++++
 6 files changed, 60 insertions(+), 4 deletions(-)

diff --git a/app/test/test_rib.c b/app/test/test_rib.c
index a4a683140df3..f56490e67ec0 100644
--- a/app/test/test_rib.c
+++ b/app/test/test_rib.c
@@ -300,6 +300,7 @@ test_tree_traversal(void)
 	uint32_t ip1 = RTE_IPV4(10, 10, 10, 0);
 	uint32_t ip2 = RTE_IPV4(10, 10, 130, 80);
 	uint8_t depth = 30;
+	unsigned int num;
 
 	config.max_nodes = MAX_RULES;
 	config.ext_sz = 0;
@@ -313,11 +314,26 @@ test_tree_traversal(void)
 	node = rte_rib_insert(rib, ip2, depth);
 	RTE_TEST_ASSERT(node != NULL, "Failed to insert rule\n");
 
+	node = rte_rib_insert(rib, 0, 0);
+	RTE_TEST_ASSERT(node != NULL, "Failed to insert default rule\n");
+
 	node = NULL;
 	node = rte_rib_get_nxt(rib, RTE_IPV4(10, 10, 130, 0), 24, node,
 			RTE_RIB_GET_NXT_ALL);
 	RTE_TEST_ASSERT(node != NULL, "Failed to get rib_node\n");
 
+	num = 0;
+	node = NULL;
+	while ((node = rte_rib_get_nxt(rib, 0, 0, node, RTE_RIB_GET_NXT_ALL)) != NULL)
+		num++;
+	RTE_TEST_ASSERT(num == 2, "Invalid number of routes\n");
+
+	num = 0;
+	node = NULL;
+	while ((node = rte_rib_get_nxt(rib, 0, 0, node, RTE_RIB_GET_NXT_ALL_TOP)) != NULL)
+		num++;
+	RTE_TEST_ASSERT(num == 3, "Default route not returned by rte_rib_get_nxt\n");
+
 	rte_rib_free(rib);
 
 	return TEST_SUCCESS;
diff --git a/app/test/test_rib6.c b/app/test/test_rib6.c
index 0295a9640cfa..542c955eee8c 100644
--- a/app/test/test_rib6.c
+++ b/app/test/test_rib6.c
@@ -300,7 +300,9 @@ test_tree_traversal(void)
 	struct rte_ipv6_addr ip = RTE_IPV6(0x0a00, 0x0282, 0, 0, 0, 0, 0, 0);
 	struct rte_ipv6_addr ip1 = RTE_IPV6(0x0a00, 0x0200, 0, 0, 0, 0, 0, 0);
 	struct rte_ipv6_addr ip2 = RTE_IPV6(0x0a00, 0x0282, 0, 0, 0, 0, 0, 0x0050);
+	struct rte_ipv6_addr unspec = RTE_IPV6(0, 0, 0, 0, 0, 0, 0, 0);
 	uint8_t depth = 126;
+	unsigned int num;
 
 	config.max_nodes = MAX_RULES;
 	config.ext_sz = 0;
@@ -312,11 +314,25 @@ test_tree_traversal(void)
 	RTE_TEST_ASSERT(node != NULL, "Failed to insert rule\n");
 	node = rte_rib6_insert(rib, &ip2, depth);
 	RTE_TEST_ASSERT(node != NULL, "Failed to insert rule\n");
+	node = rte_rib6_insert(rib, &unspec, 0);
+	RTE_TEST_ASSERT(node != NULL, "Failed to insert default route\n");
 
 	node = NULL;
 	node = rte_rib6_get_nxt(rib, &ip, 32, node, RTE_RIB6_GET_NXT_ALL);
 	RTE_TEST_ASSERT(node != NULL, "Failed to get rib_node\n");
 
+	num = 0;
+	node = NULL;
+	while ((node = rte_rib6_get_nxt(rib, 0, 0, node, RTE_RIB6_GET_NXT_ALL)) != NULL)
+		num++;
+	RTE_TEST_ASSERT(num == 2, "Invalid number of routes\n");
+
+	num = 0;
+	node = NULL;
+	while ((node = rte_rib6_get_nxt(rib, 0, 0, node, RTE_RIB6_GET_NXT_ALL_TOP)) != NULL)
+		num++;
+	RTE_TEST_ASSERT(num == 3, "Default route not returned by rte_rib6_get_nxt\n");
+
 	rte_rib6_free(rib);
 
 	return TEST_SUCCESS;
diff --git a/lib/rib/rte_rib.c b/lib/rib/rte_rib.c
index 89061829a23c..a3c287e215ec 100644
--- a/lib/rib/rte_rib.c
+++ b/lib/rib/rte_rib.c
@@ -167,6 +167,14 @@ rte_rib_lookup_exact(struct rte_rib *rib, uint32_t ip, uint8_t depth)
 	return __rib_lookup_exact(rib, ip, depth);
 }
 
+static bool
+depth_match(struct rte_rib_node *node, uint8_t depth, int flag)
+{
+	if (flag == RTE_RIB_GET_NXT_ALL_TOP)
+		return node->depth >= depth;
+	return node->depth > depth;
+}
+
 /*
  *  Traverses on subtree and retrieves more specific routes
  *  for a given in args ip/depth prefix
@@ -195,7 +203,7 @@ rte_rib_get_nxt(struct rte_rib *rib, uint32_t ip,
 			tmp = tmp->parent;
 			if (is_valid_node(tmp) &&
 					(is_covered(tmp->ip, ip, depth) &&
-					(tmp->depth > depth)))
+					(depth_match(tmp, depth, mode))))
 				return tmp;
 		}
 		tmp = (tmp->parent) ? tmp->parent->right : NULL;
@@ -203,7 +211,7 @@ rte_rib_get_nxt(struct rte_rib *rib, uint32_t ip,
 	while (tmp) {
 		if (is_valid_node(tmp) &&
 				(is_covered(tmp->ip, ip, depth) &&
-				(tmp->depth > depth))) {
+				(depth_match(tmp, depth, mode)))) {
 			prev = tmp;
 			if (mode == RTE_RIB_GET_NXT_COVER)
 				return prev;
diff --git a/lib/rib/rte_rib.h b/lib/rib/rte_rib.h
index 0fabfb2a41a6..5e72fa9273e2 100644
--- a/lib/rib/rte_rib.h
+++ b/lib/rib/rte_rib.h
@@ -31,6 +31,8 @@ enum rte_rib_nxt_mode {
 	RTE_RIB_GET_NXT_ALL,
 	/** get first matched subroutes in a RIB tree, excluding any exact match top-level route */
 	RTE_RIB_GET_NXT_COVER,
+	/** get all subroutes in a RIB tree, including the exact match top-level route, if any */
+	RTE_RIB_GET_NXT_ALL_TOP,
 };
 
 struct rte_rib;
@@ -125,6 +127,8 @@ rte_rib_lookup_exact(struct rte_rib *rib, uint32_t ip, uint8_t depth);
  *   get all prefixes from subtrie
  *  -RTE_RIB_GET_NXT_COVER
  *   get only first more specific prefix even if it have more specifics
+ *  -RTE_RIB_GET_NXT_ALL_TOP
+ *   get the top-level exact matching prefix, if any
  * @return
  *  pointer to the next more specific prefix
  *  NULL if there is no prefixes left
diff --git a/lib/rib/rte_rib6.c b/lib/rib/rte_rib6.c
index c23881f6247e..5114fb522e3e 100644
--- a/lib/rib/rte_rib6.c
+++ b/lib/rib/rte_rib6.c
@@ -186,6 +186,14 @@ rte_rib6_lookup_exact(struct rte_rib6 *rib,
 	return NULL;
 }
 
+static bool
+depth_match(struct rte_rib6_node *node, uint8_t depth, enum rte_rib6_nxt_mode mode)
+{
+	if (mode == RTE_RIB6_GET_NXT_ALL_TOP)
+		return node->depth >= depth;
+	return node->depth > depth;
+}
+
 /*
  *  Traverses on subtree and retrieves more specific routes
  *  for a given in args ip/depth prefix
@@ -219,7 +227,7 @@ rte_rib6_get_nxt(struct rte_rib6 *rib,
 			tmp = tmp->parent;
 			if (is_valid_node(tmp) &&
 					(rte_ipv6_addr_eq_prefix(&tmp->ip, &tmp_ip, depth) &&
-					(tmp->depth > depth)))
+					(depth_match(tmp, depth, mode))))
 				return tmp;
 		}
 		tmp = (tmp->parent != NULL) ? tmp->parent->right : NULL;
@@ -227,7 +235,7 @@ rte_rib6_get_nxt(struct rte_rib6 *rib,
 	while (tmp) {
 		if (is_valid_node(tmp) &&
 				(rte_ipv6_addr_eq_prefix(&tmp->ip, &tmp_ip, depth) &&
-				(tmp->depth > depth))) {
+				(depth_match(tmp, depth, mode)))) {
 			prev = tmp;
 			if (mode == RTE_RIB6_GET_NXT_COVER)
 				return prev;
diff --git a/lib/rib/rte_rib6.h b/lib/rib/rte_rib6.h
index ed2761492bc8..1d8b56b89b13 100644
--- a/lib/rib/rte_rib6.h
+++ b/lib/rib/rte_rib6.h
@@ -32,6 +32,8 @@ enum rte_rib6_nxt_mode {
 	RTE_RIB6_GET_NXT_ALL,
 	/** get first matched subroutes in a RIB tree, excluding any exact match top-level route */
 	RTE_RIB6_GET_NXT_COVER,
+	/** get all subroutes in a RIB tree, including the exact match top-level route, if any */
+	RTE_RIB6_GET_NXT_ALL_TOP,
 };
 
 struct rte_rib6;
@@ -184,6 +186,8 @@ rte_rib6_lookup_exact(struct rte_rib6 *rib,
  *   get all prefixes from subtrie
  *  -RTE_RIB6_GET_NXT_COVER
  *   get only first more specific prefix even if it have more specifics
+ *  -RTE_RIB6_GET_NXT_ALL_TOP
+ *   get the top-level exact matching prefix, if any
  * @return
  *  pointer to the next more specific prefix
  *  NULL if there is no prefixes left
-- 
2.54.0