[PATCH v3 03/14] node: add IP4 FIB route add

[Ankur Dwivedi <adwivedi@marvell.com>]

Adds a public function to add IP4 route to FIB. The applications should
call this function to add IP4 routes to FIB.

Signed-off-by: Ankur Dwivedi <adwivedi@marvell.com>
---
 lib/node/ip4_lookup_fib.c   | 37 +++++++++++++++++++++++++++++++++++++
 lib/node/rte_node_ip4_api.h | 19 +++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/lib/node/ip4_lookup_fib.c b/lib/node/ip4_lookup_fib.c
index 977d97b713..f300266c00 100644
--- a/lib/node/ip4_lookup_fib.c
+++ b/lib/node/ip4_lookup_fib.c
@@ -2,6 +2,8 @@
  * Copyright(C) 2025 Marvell.
  */
 
+#include <arpa/inet.h>
+
 #include <eal_export.h>
 #include <rte_errno.h>
 #include <rte_ether.h>
@@ -58,6 +60,41 @@ rte_node_ip4_fib_create(int socket, struct rte_fib_conf *conf)
 	return 0;
 }
 
+RTE_EXPORT_EXPERIMENTAL_SYMBOL(rte_node_ip4_fib_route_add, 25.07)
+int
+rte_node_ip4_fib_route_add(uint32_t ip, uint8_t depth, uint16_t next_hop,
+			   enum rte_node_ip4_lookup_next next_node)
+{
+	char abuf[INET6_ADDRSTRLEN];
+	unsigned int nb_sockets;
+	struct in_addr in;
+	uint8_t socket;
+	uint32_t val;
+	int ret;
+
+	nb_sockets = rte_socket_count();
+	in.s_addr = htonl(ip);
+	inet_ntop(AF_INET, &in, abuf, sizeof(abuf));
+	/* Embedded next node id into 24 bit next hop */
+	val = ((next_node << 16) | next_hop) & ((1ull << 24) - 1);
+	node_dbg("ip4_lookup_fib", "FIB: Adding route %s / %d nh (0x%x)", abuf, depth, val);
+
+	for (socket = 0; socket < nb_sockets; socket++) {
+		if (!ip4_lookup_fib_nm.fib[socket])
+			continue;
+
+		ret = rte_fib_add(ip4_lookup_fib_nm.fib[socket], ip, depth, val);
+		if (ret < 0) {
+			node_err("ip4_lookup_fib",
+				 "Unable to add entry %s / %d nh (%x) to FIB on sock %d, rc=%d",
+				 abuf, depth, val, socket, ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
 static int
 setup_fib(int socket)
 {
diff --git a/lib/node/rte_node_ip4_api.h b/lib/node/rte_node_ip4_api.h
index 1dac7a4936..4d75c5f874 100644
--- a/lib/node/rte_node_ip4_api.h
+++ b/lib/node/rte_node_ip4_api.h
@@ -132,6 +132,25 @@ int rte_node_ip4_reassembly_configure(struct rte_node_ip4_reassembly_cfg *cfg, u
 __rte_experimental
 int rte_node_ip4_fib_create(int socket, struct rte_fib_conf *conf);
 
+/**
+ * Add ipv4 route to FIB.
+ *
+ * @param ip
+ *   IP address of route to be added.
+ * @param depth
+ *   Depth of the rule to be added.
+ * @param next_hop
+ *   Next hop id of the rule result to be added.
+ * @param next_node
+ *   Next node to redirect traffic to.
+ *
+ * @return
+ *   0 on success, negative otherwise.
+ */
+__rte_experimental
+int rte_node_ip4_fib_route_add(uint32_t ip, uint8_t depth, uint16_t next_hop,
+			       enum rte_node_ip4_lookup_next next_node);
+
 #ifdef __cplusplus
 }
 #endif
-- 
2.25.1