uhd-dpdk: Add DPDK-based sockets-like library

This library makes available a userspace network stack with a
socket-like interface for applications (except the sockets pass around
pointers to buffers and use the buffers directly--It's sockets + a
put/get for buffer management). Supported services are ARP and UDP.
Destinations can be unicast or broadcast. Multicast is not currently
supported.

The implementation has two driver layers. The upper layer runs within
the caller's context. The caller will make requests through lockless
ring buffers (including socket creation and packet transmission), and
the lower layer will implement the requests and provide a response.

Currently, the lower layer runs in a separate I/O thread, and the caller
will block until it receives a response.

The I/O thread's main body is in src/uhd_dpdk_driver.c. You'll find that
all I/O thread functions are prefixed by an underscore, and user thread
functions do not.

src/uhd_dpdk.c is used to initialize uhd-dpdk and bring up the network
interfaces.

src/uhd_dpdk_fops.c and src/uhd_dpdk_udp.c are for network services.

The test is a benchmark of a flow control loop using a certain made-up
protocol with credits and sequence number tracking.

1 files changed, 303 insertions, 0 deletions

diff --git a/host/lib/transport/uhd-dpdk/test/test.c b/host/lib/transport/uhd-dpdk/test/test.c
new file mode 100644
index 000000000..c324561de
--- /dev/null
+++ b/host/lib/transport/uhd-dpdk/test/test.c
@@ -0,0 +1,303 @@
+//
+// Copyright 2018 Ettus Research, a National Instruments Company
+//
+// SPDX-License-Identifier: GPL-3.0-or-later
+//
+/**
+ * Benchmark program to check performance of 2 simultaneous links
+ */
+
+
+#include <uhd-dpdk.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include <errno.h>
+#include <arpa/inet.h>
+
+#define NUM_MBUFS 4095
+#define MBUF_CACHE_SIZE 315
+#define BURST_SIZE 64
+
+#define NUM_PORTS 2
+#define TX_CREDITS 28
+#define RX_CREDITS 64
+#define BENCH_SPP 700
+#define BENCH_IFG 220
+
+
+static uint32_t last_seqno[NUM_PORTS];
+static uint32_t dropped_packets[NUM_PORTS];
+static uint32_t lasts[NUM_PORTS][16], drops[NUM_PORTS][16];
+static uint32_t last_ackno[NUM_PORTS];
+static uint32_t tx_seqno[NUM_PORTS];
+static uint64_t tx_xfer[NUM_PORTS];
+
+static void process_udp(int id, uint32_t *udp_data)
+{
+	if (udp_data[0] != last_seqno[id] + 1) {
+		lasts[id][dropped_packets[id] & 0xf] = last_seqno[id];
+		drops[id][dropped_packets[id] & 0xf] = udp_data[0];
+		dropped_packets[id]++;
+	}
+
+	last_seqno[id] = udp_data[0];
+	last_ackno[id] = udp_data[1];
+}
+
+static void send_ctrl(struct uhd_dpdk_socket *sock, uint32_t run)
+{
+	struct rte_mbuf *mbuf = NULL;
+	uhd_dpdk_request_tx_bufs(sock, &mbuf, 1);
+	if (unlikely(mbuf == NULL))
+		return;
+	uint32_t *tx_data = uhd_dpdk_buf_to_data(sock, mbuf);
+	tx_data[0] = (BENCH_SPP << 16) | (TX_CREDITS << 4) | run; // spp, tx_credits, run
+	tx_data[1] = (RX_CREDITS << 16) | (BENCH_IFG); // credits, ifg
+	mbuf->pkt_len = 8;
+	mbuf->data_len = 8;
+	uhd_dpdk_send(sock, &mbuf, 1);
+}
+
+static void send_udp(struct uhd_dpdk_socket *sock, int id, bool fc_only)
+{
+	struct rte_mbuf *mbuf = NULL;
+	uhd_dpdk_request_tx_bufs(sock, &mbuf, 1);
+	if (unlikely(mbuf == NULL))
+		return;
+	uint32_t *tx_data = uhd_dpdk_buf_to_data(sock, mbuf);
+	tx_data[0] = fc_only ? tx_seqno[id] - 1 : tx_seqno[id];
+	tx_data[1] = last_seqno[id];
+	if (!fc_only) {
+		memset(&tx_data[2], last_seqno[id], 8*BENCH_SPP);
+		tx_xfer[id] += 8*BENCH_SPP;
+	}
+	mbuf->pkt_len = 8 + (fc_only ? 0 : 8*BENCH_SPP);
+	mbuf->data_len = 8 + (fc_only ? 0 : 8*BENCH_SPP);
+
+	uhd_dpdk_send(sock, &mbuf, 1);
+
+	if (!fc_only) {
+		tx_seqno[id]++;
+	}
+}
+
+static void bench(struct uhd_dpdk_socket **tx, struct uhd_dpdk_socket **rx, struct uhd_dpdk_socket **ctrl, uint32_t nb_ports)
+{
+	uint64_t total_xfer[NUM_PORTS];
+	uint32_t id;
+	for (id = 0; id < nb_ports; id++) {
+		tx_seqno[id] = 1;
+		tx_xfer[id] = 0;
+		last_ackno[id] = 0;
+		last_seqno[id] = 0;
+		dropped_packets[id] = 0;
+		total_xfer[id] = 0;
+	}
+	sleep(1);
+	struct timeval bench_start, bench_end;
+	gettimeofday(&bench_start, NULL);
+	for (id = 0; id < nb_ports; id++) {
+		send_ctrl(ctrl[id], 0);
+		for (int pktno = 0; (pktno < TX_CREDITS*3/4); pktno++) {
+			send_udp(tx[id], id, false);
+		}
+	}
+	for (id = 0; id < nb_ports; id++) {
+		send_ctrl(ctrl[id], 1);
+	}
+	/*
+	 * The test...
+	 */
+	uint64_t total_received = 0;
+	uint32_t consec_no_rx = 0;
+	while (total_received < 1000000 ) { //&& consec_no_rx < 10000) {
+		for (id = 0; id < nb_ports; id++) {
+
+			/* Get burst of RX packets, from first port of pair. */
+			struct rte_mbuf *bufs[BURST_SIZE];
+			const int64_t nb_rx = uhd_dpdk_recv(rx[id], bufs, BURST_SIZE);
+
+			if (unlikely(nb_rx <= 0)) {
+				consec_no_rx++;
+				if (consec_no_rx >= 100000) {
+					uint32_t skt_drops = 0;
+					uhd_dpdk_get_drop_count(rx[id], &skt_drops);
+					printf("TX seq %d, TX ack %d, RX seq %d, %d, drops!\n", tx_seqno[id], last_ackno[id], last_seqno[id], skt_drops);
+					consec_no_rx = 0;
+					break;
+				}
+				continue;
+			} else {
+				consec_no_rx = 0;
+			}
+
+			for (int buf = 0; buf < nb_rx; buf++) {
+				total_xfer[id] += bufs[buf]->pkt_len;
+				uint64_t ol_flags = bufs[buf]->ol_flags;
+				uint32_t *data = (uint32_t *) uhd_dpdk_buf_to_data(rx[id], bufs[buf]);
+				if (ol_flags == PKT_RX_IP_CKSUM_BAD) { /* FIXME: Deprecated/changed in later release */
+					printf("Buf %d: Bad IP cksum\n", buf);
+				} else {
+					process_udp(id, data);
+				}
+			}
+
+			/* Free buffers. */
+			for (int buf = 0; buf < nb_rx; buf++)
+				uhd_dpdk_free_buf(bufs[buf]);
+			total_received += nb_rx;
+		}
+
+		for (id = 0; id < nb_ports; id++) {
+			/* TX portion */
+			uint32_t window_end = last_ackno[id] + TX_CREDITS;
+			//uint32_t window_end = last_seqno[port] + TX_CREDITS;
+			if (window_end <= tx_seqno[id]) {
+				if (consec_no_rx == 9999) {
+					send_udp(tx[id], id, true);
+				}
+				//send_udp(tx[id], id, true);
+				;
+			} else {
+				for (int pktno = 0; (pktno < BURST_SIZE) && (tx_seqno[id] < window_end); pktno++) {
+					send_udp(tx[id], id, false);
+				}
+			}
+		}
+	}
+	for (id = 0; id < nb_ports; id++) {
+		send_ctrl(ctrl[id], 0);
+	}
+	gettimeofday(&bench_end, NULL);
+	printf("Benchmark complete\n\n");
+
+	for (id = 0; id < nb_ports; id++) {
+		printf("\n");
+		printf("Bytes received = %ld\n", total_xfer[id]);
+		printf("Bytes sent = %ld\n", tx_xfer[id]);
+		printf("Time taken = %ld us\n", (bench_end.tv_sec - bench_start.tv_sec)*1000000 + (bench_end.tv_usec - bench_start.tv_usec));
+		double elapsed_time = (bench_end.tv_sec - bench_start.tv_sec)*1000000 + (bench_end.tv_usec - bench_start.tv_usec);
+		elapsed_time *= 1.0e-6;
+		double elapsed_bytes = total_xfer[id];
+		printf("RX Performance = %e Gbps\n", elapsed_bytes*8.0/1.0e9/elapsed_time);
+		elapsed_bytes = tx_xfer[id];
+		printf("TX Performance = %e Gbps\n", elapsed_bytes*8.0/1.0e9/elapsed_time);
+		uint32_t skt_drops = 0;
+		uhd_dpdk_get_drop_count(rx[id], &skt_drops);
+		printf("Dropped %d packets\n", dropped_packets[id]);
+		printf("Socket reports dropped %d packets\n", skt_drops);
+		for (unsigned int i = 0; i < 16; i++) {
+			if (i >= dropped_packets[id])
+				break;
+			printf("Last(%u), Recv(%u)\n", lasts[id][i], drops[id][i]);
+		}
+		//printf("%d missed/dropped packets\n", errors);
+		printf("\n");
+	}
+
+}
+
+int main(int argc, char **argv)
+{
+	int port_thread_mapping[2] = {1, 1};
+	int status = uhd_dpdk_init(argc, argv, 2, &port_thread_mapping[0], NUM_MBUFS, MBUF_CACHE_SIZE);
+	if (status) {
+		printf("%d: Something wrong?\n", status);
+		return status;
+	}
+
+	uint32_t eth_ip = htonl(0xc0a80008);
+	uint32_t eth_mask = htonl(0xffffff00);
+	status = uhd_dpdk_set_ipv4_addr(0, eth_ip, eth_mask);
+	if (status) {
+		printf("Error while setting IP0: %d\n", status);
+		return status;
+	}
+	status = uhd_dpdk_set_ipv4_addr(1, eth_ip, eth_mask);
+	if (status) {
+		printf("Error while setting IP1: %d\n", status);
+		return status;
+	}
+
+	struct uhd_dpdk_socket *eth_rx[2];
+	struct uhd_dpdk_socket *eth_tx[2];
+	struct uhd_dpdk_socket *eth_ctrl[2];
+	struct uhd_dpdk_sockarg_udp sockarg = {
+		.is_tx = false,
+		.local_port = htons(0xBEE7),
+		.remote_port = htons(0xBEE7),
+		.dst_addr = htonl(0xc0a80004)
+	};
+	eth_rx[0] = uhd_dpdk_sock_open(0, UHD_DPDK_SOCK_UDP, &sockarg);
+	if (!eth_rx[0]) {
+		printf("!eth0_rx\n");
+		return -ENODEV;
+	}
+	eth_rx[1] = uhd_dpdk_sock_open(1, UHD_DPDK_SOCK_UDP, &sockarg);
+	if (!eth_rx[1]) {
+		printf("!eth1_rx\n");
+		return -ENODEV;
+	}
+
+	sockarg.is_tx = true;
+	eth_tx[0] = uhd_dpdk_sock_open(0, UHD_DPDK_SOCK_UDP, &sockarg);
+	if (!eth_tx[0]) {
+		printf("!eth0_tx\n");
+		return -ENODEV;
+	}
+	eth_tx[1] = uhd_dpdk_sock_open(1, UHD_DPDK_SOCK_UDP, &sockarg);
+	if (!eth_tx[1]) {
+		printf("!eth1_tx\n");
+		return -ENODEV;
+	}
+
+	sockarg.local_port = htons(0xB4D);
+	sockarg.remote_port = htons(0xB4D);
+	eth_ctrl[0] = uhd_dpdk_sock_open(0, UHD_DPDK_SOCK_UDP, &sockarg);
+	if (!eth_ctrl[0]) {
+		printf("!eth0_ctrl\n");
+		return -ENODEV;
+	}
+	eth_ctrl[1] = uhd_dpdk_sock_open(1, UHD_DPDK_SOCK_UDP, &sockarg);
+	if (!eth_ctrl[1]) {
+		printf("!eth1_ctrl\n");
+		return -ENODEV;
+	}
+
+	bench(eth_tx, eth_rx, eth_ctrl, 2);
+
+	status = uhd_dpdk_sock_close(eth_rx[0]);
+	if (status) {
+		printf("Bad close RX0 %d\n", status);
+		return status;
+	}
+	status = uhd_dpdk_sock_close(eth_rx[1]);
+	if (status) {
+		printf("Bad close RX1 %d\n", status);
+		return status;
+	}
+	status = uhd_dpdk_sock_close(eth_tx[0]);
+	if (status) {
+		printf("Bad close TX0 %d\n", status);
+		return status;
+	}
+	status = uhd_dpdk_sock_close(eth_tx[1]);
+	if (status) {
+		printf("Bad close TX1 %d\n", status);
+		return status;
+	}
+	status = uhd_dpdk_sock_close(eth_ctrl[0]);
+	if (status) {
+		printf("Bad close Ctrl0 %d\n", status);
+		return status;
+	}
+	status = uhd_dpdk_sock_close(eth_ctrl[1]);
+	if (status) {
+		printf("Bad close Ctrl1 %d\n", status);
+		return status;
+	}
+	return status;
+}