[dpdk-dev] [PATCH v3 19/29] node: add generic ipv4 lookup node

[<jerinj@marvell.com>]

From: Pavan Nikhilesh <pbhagavatula@marvell.com>

Add IPv4 lookup process function for ip4_lookup node.
This node performs LPM lookup using simple RTE_LPM API on every packet
received and forwards it to a next node that is identified by lookup
result.

Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
---
 doc/api/doxy-api-index.md          |   1 +
 lib/librte_node/Makefile           |   4 +-
 lib/librte_node/ip4_lookup.c       | 128 +++++++++++++++++++++++++++++
 lib/librte_node/meson.build        |   5 +-
 lib/librte_node/rte_node_ip4_api.h |  43 ++++++++++
 5 files changed, 178 insertions(+), 3 deletions(-)
 create mode 100644 lib/librte_node/ip4_lookup.c
 create mode 100644 lib/librte_node/rte_node_ip4_api.h

diff --git a/doc/api/doxy-api-index.md b/doc/api/doxy-api-index.md
index 1784674df..3908fddde 100644
--- a/doc/api/doxy-api-index.md
+++ b/doc/api/doxy-api-index.md
@@ -163,6 +163,7 @@ The public API headers are grouped by topics:
     [graph_worker]     (@ref rte_graph_worker.h)
   * graph_nodes:
     [eth_node]         (@ref rte_node_eth_api.h),
+    [ip4_node]         (@ref rte_node_ip4_api.h)
 
 - **basic**:
   [approx fraction]    (@ref rte_approx.h),
diff --git a/lib/librte_node/Makefile b/lib/librte_node/Makefile
index ea5fa77f7..ad3f2e349 100644
--- a/lib/librte_node/Makefile
+++ b/lib/librte_node/Makefile
@@ -11,7 +11,7 @@ CFLAGS += -O3 -DALLOW_EXPERIMENTAL_API
 CFLAGS += $(WERROR_FLAGS)
 # Strict-aliasing rules are violated by uint8_t[] to context size casts.
 CFLAGS += -fno-strict-aliasing
-LDLIBS += -lrte_eal -lrte_graph -lrte_mbuf -lrte_ethdev -lrte_mempool
+LDLIBS += -lrte_eal -lrte_graph -lrte_mbuf -lrte_lpm -lrte_ethdev -lrte_mempool
 
 EXPORT_MAP := rte_node_version.map
 
@@ -21,8 +21,10 @@ SRCS-$(CONFIG_RTE_LIBRTE_NODE) += log.c
 SRCS-$(CONFIG_RTE_LIBRTE_NODE) += ethdev_rx.c
 SRCS-$(CONFIG_RTE_LIBRTE_NODE) += ethdev_tx.c
 SRCS-$(CONFIG_RTE_LIBRTE_NODE) += ethdev_ctrl.c
+SRCS-$(CONFIG_RTE_LIBRTE_NODE) += ip4_lookup.c
 
 # install header files
+SYMLINK-$(CONFIG_RTE_LIBRTE_NODE)-include += rte_node_ip4_api.h
 SYMLINK-$(CONFIG_RTE_LIBRTE_NODE)-include += rte_node_eth_api.h
 
 include $(RTE_SDK)/mk/rte.lib.mk
diff --git a/lib/librte_node/ip4_lookup.c b/lib/librte_node/ip4_lookup.c
new file mode 100644
index 000000000..a91d42423
--- /dev/null
+++ b/lib/librte_node/ip4_lookup.c
@@ -0,0 +1,128 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(C) 2020 Marvell International Ltd.
+ */
+
+#include <arpa/inet.h>
+#include <sys/socket.h>
+
+#include <rte_debug.h>
+#include <rte_ethdev.h>
+#include <rte_ether.h>
+#include <rte_graph.h>
+#include <rte_graph_worker.h>
+#include <rte_ip.h>
+#include <rte_lpm.h>
+#include <rte_mbuf.h>
+#include <rte_tcp.h>
+#include <rte_udp.h>
+
+#include "rte_node_ip4_api.h"
+
+#include "node_private.h"
+
+#define IPV4_L3FWD_LPM_MAX_RULES 1024
+#define IPV4_L3FWD_LPM_NUMBER_TBL8S (1 << 8)
+
+/* IP4 Lookup global data struct */
+struct ip4_lookup_node_main {
+	struct rte_lpm *lpm_tbl[RTE_MAX_NUMA_NODES];
+};
+
+static uint16_t
+ip4_lookup_node_process(struct rte_graph *graph, struct rte_node *node,
+			void **objs, uint16_t nb_objs)
+{
+	struct rte_ipv4_hdr *ipv4_hdr;
+	void **to_next, **from;
+	uint16_t last_spec = 0;
+	struct rte_mbuf *mbuf;
+	rte_edge_t next_index;
+	struct rte_lpm *lpm;
+	uint16_t held = 0;
+	uint32_t drop_nh;
+	int i, rc;
+
+	/* Speculative next */
+	next_index = RTE_NODE_IP4_LOOKUP_NEXT_REWRITE;
+	/* Drop node */
+	drop_nh = ((uint32_t)RTE_NODE_IP4_LOOKUP_NEXT_PKT_DROP) << 16;
+
+	/* Get socket specific LPM from ctx */
+	lpm = *((struct rte_lpm **)node->ctx);
+	from = objs;
+
+	/* Get stream for the speculated next node */
+	to_next = rte_node_next_stream_get(graph, node, next_index, nb_objs);
+	for (i = 0; i < nb_objs; i++) {
+		uint32_t next_hop;
+		uint16_t next;
+
+		mbuf = (struct rte_mbuf *)objs[i];
+
+		/* Extract DIP of mbuf0 */
+		ipv4_hdr = rte_pktmbuf_mtod_offset(mbuf, struct rte_ipv4_hdr *,
+				sizeof(struct rte_ether_hdr));
+		/* Extract cksum, ttl as ipv4 hdr is in cache */
+		rte_node_mbuf_priv1(mbuf)->cksum = ipv4_hdr->hdr_checksum;
+		rte_node_mbuf_priv1(mbuf)->ttl = ipv4_hdr->time_to_live;
+
+		rc = rte_lpm_lookup(lpm, rte_be_to_cpu_32(ipv4_hdr->dst_addr),
+				    &next_hop);
+		next_hop = (rc == 0) ? next_hop : drop_nh;
+
+		rte_node_mbuf_priv1(mbuf)->nh = (uint16_t)next_hop;
+		next_hop = next_hop >> 16;
+		next = (uint16_t)next_hop;
+
+		if (unlikely(next_index != next)) {
+			/* Copy things successfully speculated till now */
+			rte_memcpy(to_next, from, last_spec * sizeof(from[0]));
+			from += last_spec;
+			to_next += last_spec;
+			held += last_spec;
+			last_spec = 0;
+
+			rte_node_enqueue_x1(graph, node, next, from[0]);
+			from += 1;
+		} else {
+			last_spec += 1;
+		}
+	}
+
+	/* !!! Home run !!! */
+	if (likely(last_spec == nb_objs)) {
+		rte_node_next_stream_move(graph, node, next_index);
+		return nb_objs;
+	}
+	held += last_spec;
+	rte_memcpy(to_next, from, last_spec * sizeof(from[0]));
+	rte_node_next_stream_put(graph, node, next_index, held);
+
+	return nb_objs;
+}
+
+static int
+ip4_lookup_node_init(const struct rte_graph *graph, struct rte_node *node)
+{
+	RTE_SET_USED(graph);
+	RTE_SET_USED(node);
+
+	node_dbg("ip4_lookup", "Initialized ip4_lookup node");
+
+	return 0;
+}
+
+static struct rte_node_register ip4_lookup_node = {
+	.process = ip4_lookup_node_process,
+	.name = "ip4_lookup",
+
+	.init = ip4_lookup_node_init,
+
+	.nb_edges = RTE_NODE_IP4_LOOKUP_NEXT_MAX,
+	.next_nodes = {
+		[RTE_NODE_IP4_LOOKUP_NEXT_REWRITE] = "ip4_rewrite",
+		[RTE_NODE_IP4_LOOKUP_NEXT_PKT_DROP] = "pkt_drop",
+	},
+};
+
+RTE_NODE_REGISTER(ip4_lookup_node);
diff --git a/lib/librte_node/meson.build b/lib/librte_node/meson.build
index af2eb2d91..702d21a24 100644
--- a/lib/librte_node/meson.build
+++ b/lib/librte_node/meson.build
@@ -1,8 +1,9 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright(C) 2020 Marvell International Ltd.
 
-sources = files('null.c', 'log.c', 'ethdev_rx.c', 'ethdev_tx.c', 'ethdev_ctrl.c')
-headers = files('rte_node_eth_api.h')
+sources = files('null.c', 'log.c', 'ethdev_rx.c', 'ethdev_tx.c', 'ip4_lookup.c',
+		'ethdev_ctrl.c')
+headers = files('rte_node_ip4_api.h', 'rte_node_eth_api.h')
 allow_experimental_apis = true
 # Strict-aliasing rules are violated by uint8_t[] to context size casts.
 cflags += '-fno-strict-aliasing'
diff --git a/lib/librte_node/rte_node_ip4_api.h b/lib/librte_node/rte_node_ip4_api.h
new file mode 100644
index 000000000..37c12bf82
--- /dev/null
+++ b/lib/librte_node/rte_node_ip4_api.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(C) 2020 Marvell International Ltd.
+ */
+
+#ifndef __INCLUDE_RTE_NODE_IP4_API_H__
+#define __INCLUDE_RTE_NODE_IP4_API_H__
+
+/**
+ * @file rte_node_ip4_api.h
+ *
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * This API allows to do control path functions of ip4_* nodes
+ * like ip4_lookup, ip4_rewrite.
+ *
+ */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <rte_common.h>
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * IP4 lookup next nodes.
+ */
+enum rte_node_ip4_lookup_next {
+	RTE_NODE_IP4_LOOKUP_NEXT_REWRITE,
+	/**< Rewrite node. */
+	RTE_NODE_IP4_LOOKUP_NEXT_PKT_DROP,
+	/**< Packet drop node. */
+	RTE_NODE_IP4_LOOKUP_NEXT_MAX,
+	/**< Number of next nodes of lookup node. */
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __INCLUDE_RTE_NODE_IP4_API_H__ */
-- 
2.25.1