/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdint.h>
#include <stdarg.h>
#include <inttypes.h>
#include <sys/queue.h>
#include <errno.h>
#include <signal.h>

#include <rte_common.h>
#include <rte_memory.h>
#include <rte_eal.h>
#include <rte_launch.h>
#include <rte_per_lcore.h>
#include <rte_lcore.h>
#include <rte_branch_prediction.h>
#include <rte_ring.h>
#include <rte_log.h>
#include <rte_debug.h>
#include <rte_mempool.h>
#include <rte_memcpy.h>
#include <rte_mbuf.h>
#include <rte_ether.h>
#include <rte_interrupts.h>
#include <rte_ethdev.h>
#include <rte_byteorder.h>
#include <rte_malloc.h>
#include <rte_string_fns.h>
#include <rte_bus.h>

#include "common.h"
#include "args.h"
#include "init.h"

/*
 * When doing reads from the NIC or the client queues,
 * use this batch size
 */
#define PACKET_READ_SIZE 32

/*
 * Local buffers to put packets in, used to send packets in bursts to the
 * clients
 */
struct client_rx_buf {
	struct rte_mbuf *buffer[PACKET_READ_SIZE];
	uint16_t count;
};

/* One buffer per client rx queue - dynamically allocate array */
static struct client_rx_buf *cl_rx_buf;

static const char *
get_printable_mac_addr(uint16_t port)
{
	static const struct rte_ether_addr null_mac; /* static defaults to 0 */
	static char err_address[32];
	static char addresses[RTE_MAX_ETHPORTS][32];
	int ret;

	if (unlikely(port >= RTE_MAX_ETHPORTS)) {
		if (err_address[0] == '\0')
			rte_ether_format_addr(err_address,
					sizeof(err_address), &null_mac);
		return err_address;
	}
	if (unlikely(addresses[port][0]=='\0')){
		struct rte_ether_addr mac;
		ret = rte_eth_macaddr_get(port, &mac);
		if (ret != 0) {
			printf("Failed to get MAC address (port %u): %s\n",
			       port, rte_strerror(-ret));
			return err_address;
		}
		rte_ether_format_addr(addresses[port],
				sizeof(addresses[port]), &mac);
	}
	return addresses[port];
}

/*
 * This function displays the recorded statistics for each port
 * and for each client. It uses ANSI terminal codes to clear
 * screen when called. It is called from a single worker
 * thread in the server process, when the process is run with more
 * than one lcore enabled.
 */
static void
do_stats_display(void)
{
	unsigned i, j;
	const char clr[] = { 27, '[', '2', 'J', '\0' };
	const char topLeft[] = { 27, '[', '1', ';', '1', 'H','\0' };
	uint64_t port_tx[RTE_MAX_ETHPORTS], port_tx_drop[RTE_MAX_ETHPORTS];
	uint64_t client_tx[MAX_CLIENTS], client_tx_drop[MAX_CLIENTS];

	/* to get TX stats, we need to do some summing calculations */
	memset(port_tx, 0, sizeof(port_tx));
	memset(port_tx_drop, 0, sizeof(port_tx_drop));
	memset(client_tx, 0, sizeof(client_tx));
	memset(client_tx_drop, 0, sizeof(client_tx_drop));

	for (i = 0; i < num_clients; i++){
		const volatile struct tx_stats *tx = &ports->tx_stats[i];
		for (j = 0; j < ports->num_ports; j++){
			/* assign to local variables here, save re-reading volatile vars */
			const uint64_t tx_val = tx->tx[ports->id[j]];
			const uint64_t drop_val = tx->tx_drop[ports->id[j]];
			port_tx[j] += tx_val;
			port_tx_drop[j] += drop_val;
			client_tx[i] += tx_val;
			client_tx_drop[i] += drop_val;
		}
	}

	/* Clear screen and move to top left */
	printf("%s%s", clr, topLeft);

	printf("PORTS\n");
	printf("-----\n");
	for (i = 0; i < ports->num_ports; i++)
		printf("Port %u: '%s'\t", (unsigned)ports->id[i],
				get_printable_mac_addr(ports->id[i]));
	printf("\n\n");
	for (i = 0; i < ports->num_ports; i++){
		printf("Port %u - rx: %9"PRIu64"\t"
				"tx: %9"PRIu64"\n",
				(unsigned)ports->id[i], ports->rx_stats.rx[i],
				port_tx[i]);
	}

	printf("\nCLIENTS\n");
	printf("-------\n");
	for (i = 0; i < num_clients; i++){
		const unsigned long long rx = clients[i].stats.rx;
		const unsigned long long rx_drop = clients[i].stats.rx_drop;
		printf("Client %2u - rx: %9llu, rx_drop: %9llu\n"
				"            tx: %9"PRIu64", tx_drop: %9"PRIu64"\n",
				i, rx, rx_drop, client_tx[i], client_tx_drop[i]);
	}

	printf("\n");
}

/*
 * The function called from each worker lcore used by the process.
 * The test_and_set function is used to randomly pick a single lcore on which
 * the code to display the statistics will run. Otherwise, the code just
 * repeatedly sleeps.
 */
static int
sleep_lcore(__rte_unused void *dummy)
{
	/* Used to pick a display thread - static, so zero-initialised */
	static uint32_t display_stats;

	uint32_t status = 0;
	/* Only one core should display stats */
	if (__atomic_compare_exchange_n(&display_stats, &status, 1, 0,
			__ATOMIC_RELAXED, __ATOMIC_RELAXED)) {
		const unsigned sleeptime = 1;
		printf("Core %u displaying statistics\n", rte_lcore_id());

		/* Longer initial pause so above printf is seen */
		sleep(sleeptime * 3);

		/* Loop forever: sleep always returns 0 or <= param */
		while (sleep(sleeptime) <= sleeptime)
			do_stats_display();
	}
	return 0;
}

/*
 * Function to set all the client statistic values to zero.
 * Called at program startup.
 */
static void
clear_stats(void)
{
	unsigned i;

	for (i = 0; i < num_clients; i++)
		clients[i].stats.rx = clients[i].stats.rx_drop = 0;
}

/*
 * send a burst of traffic to a client, assuming there are packets
 * available to be sent to this client
 */
static void
flush_rx_queue(uint16_t client)
{
	uint16_t j;
	struct client *cl;

	if (cl_rx_buf[client].count == 0)
		return;

	cl = &clients[client];
	if (rte_ring_enqueue_bulk(cl->rx_q, (void **)cl_rx_buf[client].buffer,
			cl_rx_buf[client].count, NULL) == 0){
		for (j = 0; j < cl_rx_buf[client].count; j++)
			rte_pktmbuf_free(cl_rx_buf[client].buffer[j]);
		cl->stats.rx_drop += cl_rx_buf[client].count;
	}
	else
		cl->stats.rx += cl_rx_buf[client].count;

	cl_rx_buf[client].count = 0;
}

/*
 * marks a packet down to be sent to a particular client process
 */
static inline void
enqueue_rx_packet(uint8_t client, struct rte_mbuf *buf)
{
	cl_rx_buf[client].buffer[cl_rx_buf[client].count++] = buf;
}

/*
 * This function takes a group of packets and routes them
 * individually to the client process. Very simply round-robins the packets
 * without checking any of the packet contents.
 */
static void
process_packets(uint32_t port_num __rte_unused,
		struct rte_mbuf *pkts[], uint16_t rx_count)
{
	uint16_t i;
	static uint8_t client;

	for (i = 0; i < rx_count; i++) {
		enqueue_rx_packet(client, pkts[i]);

		if (++client == num_clients)
			client = 0;
	}

	for (i = 0; i < num_clients; i++)
		flush_rx_queue(i);
}

/*
 * Function called by the main lcore of the DPDK process.
 */
static void
do_packet_forwarding(void)
{
	unsigned port_num = 0; /* indexes the port[] array */

	for (;;) {
		struct rte_mbuf *buf[PACKET_READ_SIZE];
		uint16_t rx_count;

		/* read a port */
		rx_count = rte_eth_rx_burst(ports->id[port_num], 0, \
				buf, PACKET_READ_SIZE);
		ports->rx_stats.rx[port_num] += rx_count;

		/* Now process the NIC packets read */
		if (likely(rx_count > 0))
			process_packets(port_num, buf, rx_count);

		/* move to next port */
		if (++port_num == ports->num_ports)
			port_num = 0;
	}
}

static void
signal_handler(int signal)
{
	uint16_t port_id;

	if (signal == SIGINT) {
		RTE_ETH_FOREACH_DEV(port_id) {
			rte_eth_dev_stop(port_id);
			rte_eth_dev_close(port_id);
		}
		rte_bus_close();
	}
	exit(0);
}

int
main(int argc, char *argv[])
{
	signal(SIGINT, signal_handler);
	/* initialise the system */
	if (init(argc, argv) < 0 )
		return -1;
	RTE_LOG(INFO, APP, "Finished Process Init.\n");

	cl_rx_buf = calloc(num_clients, sizeof(cl_rx_buf[0]));

	/* clear statistics */
	clear_stats();

	/* put all other cores to sleep except main */
	rte_eal_mp_remote_launch(sleep_lcore, NULL, SKIP_MAIN);

	do_packet_forwarding();

	/* clean up the EAL */
	rte_eal_cleanup();

	return 0;
}
