xdpsock_2_ifaces.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2017 - 2018 Intel Corporation. */

#include <asm/barrier.h>
#include <errno.h>
#include <getopt.h>
#include <libgen.h>
#include <linux/bpf.h>
#include <linux/compiler.h>
#include <linux/if_link.h>
#include <linux/if_xdp.h>
#include <linux/if_ether.h>
#include <linux/ip.h>
#include <linux/limits.h>
#include <linux/udp.h>
#include <arpa/inet.h>
#include <locale.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <poll.h>
#include <pthread.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/capability.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/un.h>
#include <time.h>
#include <unistd.h>

#include <bpf/libbpf.h>
#include <bpf/xsk.h>
#include <bpf/bpf.h>
#include "xdpsock.h"

#ifndef SOL_XDP
#define SOL_XDP 283
#endif

#ifndef AF_XDP
#define AF_XDP 44
#endif

#ifndef PF_XDP
#define PF_XDP AF_XDP
#endif

#define NUM_FRAMES (4 * 1024)
#define MIN_PKT_SIZE 64

#define DEBUG_HEXDUMP 0

typedef __u64 u64;
typedef __u32 u32;
typedef __u16 u16;
typedef __u8  u8;

static unsigned long prev_time;

enum benchmark_type {
    BENCH_RXDROP = 0,
    BENCH_TXONLY = 1,
    BENCH_L2FWD = 2,
};

static enum benchmark_type opt_bench = BENCH_RXDROP;
static u32 opt_xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
static int opt_num_ports = 0;
static unsigned long opt_duration;
static unsigned long start_time;
static bool benchmark_done;
static u32 opt_batch_size = 64;
static int opt_pkt_count;
static u16 opt_pkt_size = MIN_PKT_SIZE;
static u32 opt_pkt_fill_pattern = 0x12345678;
static bool opt_extra_stats;
static bool opt_quiet;
static bool opt_app_stats;
static const char *opt_irq_str = "";
static u32 irq_no;
static int irqs_at_init = -1;
static int opt_poll;
static int opt_interval = 1;
static u32 opt_xdp_bind_flags = XDP_USE_NEED_WAKEUP;
static u32 opt_umem_flags;
static int opt_unaligned_chunks;
static int opt_mmap_flags;
static int opt_xsk_frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
static int opt_timeout = 1000;
static bool opt_need_wakeup = true;
static u32 opt_num_xsks = 1;
static bool opt_busy_poll;
static bool opt_reduced_cap;

struct xsk_ring_stats {
    unsigned long rx_npkts;
    unsigned long tx_npkts;
    unsigned long rx_dropped_npkts;
    unsigned long rx_invalid_npkts;
    unsigned long tx_invalid_npkts;
    unsigned long rx_full_npkts;
    unsigned long rx_fill_empty_npkts;
    unsigned long tx_empty_npkts;
    unsigned long prev_rx_npkts;
    unsigned long prev_tx_npkts;
    unsigned long prev_rx_dropped_npkts;
    unsigned long prev_rx_invalid_npkts;
    unsigned long prev_tx_invalid_npkts;
    unsigned long prev_rx_full_npkts;
    unsigned long prev_rx_fill_empty_npkts;
    unsigned long prev_tx_empty_npkts;
};

struct xsk_driver_stats {
    unsigned long intrs;
    unsigned long prev_intrs;
};

struct xsk_app_stats {
    unsigned long rx_empty_polls;
    unsigned long fill_fail_polls;
    unsigned long copy_tx_sendtos;
    unsigned long tx_wakeup_sendtos;
    unsigned long opt_polls;
    unsigned long prev_rx_empty_polls;
    unsigned long prev_fill_fail_polls;
    unsigned long prev_copy_tx_sendtos;
    unsigned long prev_tx_wakeup_sendtos;
    unsigned long prev_opt_polls;
};

struct xsk_umem_info {
    struct xsk_umem *umem;
    void *buffer;
};

/*
 * A port is an (interface, queue) pair, each ports needs its own fill and
 * completion rings
 */
struct xsk_port_info {
    char *ifname;
    int ifindex;
    int queue;
    struct xsk_umem_info *umem;
    struct xsk_ring_prod fq;
    struct xsk_ring_cons cq;
};

struct xsk_socket_info {
    struct xsk_ring_cons rx;
    struct xsk_ring_prod tx;
    struct xsk_port_info *port;
    struct xsk_socket *xsk;
    struct xsk_ring_stats ring_stats;
    struct xsk_app_stats app_stats;
    struct xsk_driver_stats drv_stats;
    u32 outstanding_tx;
};

static int num_socks;
struct xsk_port_info ports[MAX_PORTS];
struct xsk_socket_info *xsks[MAX_SOCKS];
struct xsk_umem_info umem;
int sock;

static unsigned long get_nsecs(void)
{
    struct timespec ts;

    clock_gettime(CLOCK_MONOTONIC, &ts);
    return ts.tv_sec * 1000000000UL + ts.tv_nsec;
}

static void print_benchmark(bool running)
{
    const char *bench_str = "INVALID";

    if (opt_bench == BENCH_RXDROP)
        bench_str = "rxdrop";
    else if (opt_bench == BENCH_TXONLY)
        bench_str = "txonly";
    else if (opt_bench == BENCH_L2FWD)
        bench_str = "l2fwd";

    printf("%s ", bench_str);
    if (opt_xdp_flags & XDP_FLAGS_SKB_MODE)
        printf("xdp-skb ");
    else if (opt_xdp_flags & XDP_FLAGS_DRV_MODE)
        printf("xdp-drv ");
    else
        printf("    ");

    if (opt_poll)
        printf("poll() ");

    if (running) {
        printf("running...");
        fflush(stdout);
    }
}

static int xsk_get_xdp_stats(int fd, struct xsk_socket_info *xsk)
{
    struct xdp_statistics stats;
    socklen_t optlen;
    int err;

    optlen = sizeof(stats);
    err = getsockopt(fd, SOL_XDP, XDP_STATISTICS, &stats, &optlen);
    if (err)
        return err;

    if (optlen == sizeof(struct xdp_statistics)) {
        xsk->ring_stats.rx_dropped_npkts = stats.rx_dropped;
        xsk->ring_stats.rx_invalid_npkts = stats.rx_invalid_descs;
        xsk->ring_stats.tx_invalid_npkts = stats.tx_invalid_descs;
        xsk->ring_stats.rx_full_npkts = stats.rx_ring_full;
        xsk->ring_stats.rx_fill_empty_npkts = stats.rx_fill_ring_empty_descs;
        xsk->ring_stats.tx_empty_npkts = stats.tx_ring_empty_descs;
        return 0;
    }

    return -EINVAL;
}

static void dump_app_stats(struct xsk_socket_info *xsk, long dt)
{
    char *fmt = "%-18s %'-14.0f %'-14lu\n";
    double rx_empty_polls_ps, fill_fail_polls_ps, copy_tx_sendtos_ps,
            tx_wakeup_sendtos_ps, opt_polls_ps;

    rx_empty_polls_ps = (xsk->app_stats.rx_empty_polls -
                xsk->app_stats.prev_rx_empty_polls) * 1000000000. / dt;
    fill_fail_polls_ps = (xsk->app_stats.fill_fail_polls -
                xsk->app_stats.prev_fill_fail_polls) * 1000000000. / dt;
    copy_tx_sendtos_ps = (xsk->app_stats.copy_tx_sendtos -
                xsk->app_stats.prev_copy_tx_sendtos) * 1000000000. / dt;
    tx_wakeup_sendtos_ps = (xsk->app_stats.tx_wakeup_sendtos -
                xsk->app_stats.prev_tx_wakeup_sendtos)
                                    * 1000000000. / dt;
    opt_polls_ps = (xsk->app_stats.opt_polls -
                xsk->app_stats.prev_opt_polls) * 1000000000. / dt;

    printf("%-18s %-14s %-14s\n", "", "calls/s", "count");
    printf(fmt, "rx empty polls", rx_empty_polls_ps, xsk->app_stats.rx_empty_polls);
    printf(fmt, "fill fail polls", fill_fail_polls_ps,
                        xsk->app_stats.fill_fail_polls);
    printf(fmt, "copy tx sendtos", copy_tx_sendtos_ps,
                        xsk->app_stats.copy_tx_sendtos);
    printf(fmt, "tx wakeup sendtos", tx_wakeup_sendtos_ps,
                        xsk->app_stats.tx_wakeup_sendtos);
    printf(fmt, "opt polls", opt_polls_ps, xsk->app_stats.opt_polls);

    xsk->app_stats.prev_rx_empty_polls = xsk->app_stats.rx_empty_polls;
    xsk->app_stats.prev_fill_fail_polls = xsk->app_stats.fill_fail_polls;
    xsk->app_stats.prev_copy_tx_sendtos = xsk->app_stats.copy_tx_sendtos;
    xsk->app_stats.prev_tx_wakeup_sendtos = xsk->app_stats.tx_wakeup_sendtos;
    xsk->app_stats.prev_opt_polls = xsk->app_stats.opt_polls;
}

static bool get_interrupt_number(void)
{
    FILE *f_int_proc;
    char line[4096];
    bool found = false;

    f_int_proc = fopen("/proc/interrupts", "r");
    if (f_int_proc == NULL) {
        printf("Failed to open /proc/interrupts.\n");
        return found;
    }

    while (!feof(f_int_proc) && !found) {
        /* Make sure to read a full line at a time */
        if (fgets(line, sizeof(line), f_int_proc) == NULL ||
                line[strlen(line) - 1] != '\n') {
            printf("Error reading from interrupts file\n");
            break;
        }

        /* Extract interrupt number from line */
        if (strstr(line, opt_irq_str) != NULL) {
            irq_no = atoi(line);
            found = true;
            break;
        }
    }

    fclose(f_int_proc);

    return found;
}

static int get_irqs(void)
{
    char count_path[PATH_MAX];
    int total_intrs = -1;
    FILE *f_count_proc;
    char line[4096];

    snprintf(count_path, sizeof(count_path),
        "/sys/kernel/irq/%i/per_cpu_count", irq_no);
    f_count_proc = fopen(count_path, "r");
    if (f_count_proc == NULL) {
        printf("Failed to open %s\n", count_path);
        return total_intrs;
    }

    if (fgets(line, sizeof(line), f_count_proc) == NULL ||
            line[strlen(line) - 1] != '\n') {
        printf("Error reading from %s\n", count_path);
    } else {
        static const char com[2] = ",";
        char *token;

        total_intrs = 0;
        token = strtok(line, com);
        while (token != NULL) {
            /* sum up interrupts across all cores */
            total_intrs += atoi(token);
            token = strtok(NULL, com);
        }
    }

    fclose(f_count_proc);

    return total_intrs;
}

static void dump_driver_stats(long dt)
{
    int i;

    for (i = 0; i < num_socks && xsks[i]; i++) {
        char *fmt = "%-18s %'-14.0f %'-14lu\n";
        double intrs_ps;
        int n_ints = get_irqs();

        if (n_ints < 0) {
            printf("error getting intr info for intr %i\n", irq_no);
            return;
        }
        xsks[i]->drv_stats.intrs = n_ints - irqs_at_init;

        intrs_ps = (xsks[i]->drv_stats.intrs - xsks[i]->drv_stats.prev_intrs) *
             1000000000. / dt;

        printf("\n%-18s %-14s %-14s\n", "", "intrs/s", "count");
        printf(fmt, "irqs", intrs_ps, xsks[i]->drv_stats.intrs);

        xsks[i]->drv_stats.prev_intrs = xsks[i]->drv_stats.intrs;
    }
}

static void dump_stats(void)
{
    unsigned long now = get_nsecs();
    long dt = now - prev_time;
    int i;

    prev_time = now;

    for (i = 0; i < num_socks && xsks[i]; i++) {
        char *fmt = "%-18s %'-14.0f %'-14lu\n";
        double rx_pps, tx_pps, dropped_pps, rx_invalid_pps, full_pps, fill_empty_pps,
            tx_invalid_pps, tx_empty_pps;

        rx_pps = (xsks[i]->ring_stats.rx_npkts - xsks[i]->ring_stats.prev_rx_npkts) *
             1000000000. / dt;
        tx_pps = (xsks[i]->ring_stats.tx_npkts - xsks[i]->ring_stats.prev_tx_npkts) *
             1000000000. / dt;

        printf("\n sock%d@%s:%d ", i, ports[i % opt_num_ports].ifname, ports[i % opt_num_ports].queue);
        print_benchmark(false);
        printf("\n");

        printf("%-18s %-14s %-14s %-14.2f\n", "", "pps", "pkts",
               dt / 1000000000.);
        printf(fmt, "rx", rx_pps, xsks[i]->ring_stats.rx_npkts);
        printf(fmt, "tx", tx_pps, xsks[i]->ring_stats.tx_npkts);

        xsks[i]->ring_stats.prev_rx_npkts = xsks[i]->ring_stats.rx_npkts;
        xsks[i]->ring_stats.prev_tx_npkts = xsks[i]->ring_stats.tx_npkts;

        if (opt_extra_stats) {
            if (!xsk_get_xdp_stats(xsk_socket__fd(xsks[i]->xsk), xsks[i])) {
                dropped_pps = (xsks[i]->ring_stats.rx_dropped_npkts -
                        xsks[i]->ring_stats.prev_rx_dropped_npkts) *
                            1000000000. / dt;
                rx_invalid_pps = (xsks[i]->ring_stats.rx_invalid_npkts -
                        xsks[i]->ring_stats.prev_rx_invalid_npkts) *
                            1000000000. / dt;
                tx_invalid_pps = (xsks[i]->ring_stats.tx_invalid_npkts -
                        xsks[i]->ring_stats.prev_tx_invalid_npkts) *
                            1000000000. / dt;
                full_pps = (xsks[i]->ring_stats.rx_full_npkts -
                        xsks[i]->ring_stats.prev_rx_full_npkts) *
                            1000000000. / dt;
                fill_empty_pps = (xsks[i]->ring_stats.rx_fill_empty_npkts -
                        xsks[i]->ring_stats.prev_rx_fill_empty_npkts) *
                            1000000000. / dt;
                tx_empty_pps = (xsks[i]->ring_stats.tx_empty_npkts -
                        xsks[i]->ring_stats.prev_tx_empty_npkts) *
                            1000000000. / dt;

                printf(fmt, "rx dropped", dropped_pps,
                       xsks[i]->ring_stats.rx_dropped_npkts);
                printf(fmt, "rx invalid", rx_invalid_pps,
                       xsks[i]->ring_stats.rx_invalid_npkts);
                printf(fmt, "tx invalid", tx_invalid_pps,
                       xsks[i]->ring_stats.tx_invalid_npkts);
                printf(fmt, "rx queue full", full_pps,
                       xsks[i]->ring_stats.rx_full_npkts);
                printf(fmt, "fill ring empty", fill_empty_pps,
                       xsks[i]->ring_stats.rx_fill_empty_npkts);
                printf(fmt, "tx ring empty", tx_empty_pps,
                       xsks[i]->ring_stats.tx_empty_npkts);

                xsks[i]->ring_stats.prev_rx_dropped_npkts =
                    xsks[i]->ring_stats.rx_dropped_npkts;
                xsks[i]->ring_stats.prev_rx_invalid_npkts =
                    xsks[i]->ring_stats.rx_invalid_npkts;
                xsks[i]->ring_stats.prev_tx_invalid_npkts =
                    xsks[i]->ring_stats.tx_invalid_npkts;
                xsks[i]->ring_stats.prev_rx_full_npkts =
                    xsks[i]->ring_stats.rx_full_npkts;
                xsks[i]->ring_stats.prev_rx_fill_empty_npkts =
                    xsks[i]->ring_stats.rx_fill_empty_npkts;
                xsks[i]->ring_stats.prev_tx_empty_npkts =
                    xsks[i]->ring_stats.tx_empty_npkts;
            } else {
                printf("%-15s\n", "Error retrieving extra stats");
            }
        }

        if (opt_app_stats)
            dump_app_stats(xsks[i], dt);
    }

    if (irq_no)
        dump_driver_stats(dt);

    printf("\n");
}

static bool is_benchmark_done(void)
{
    if (opt_duration > 0) {
        unsigned long dt = (get_nsecs() - start_time);

        if (dt >= opt_duration)
            benchmark_done = true;
    }
    return benchmark_done;
}

static void *poller(void *arg)
{
    (void)arg;
    while (!is_benchmark_done()) {
        sleep(opt_interval);
        dump_stats();
    }

    return NULL;
}

static void int_exit(int sig)
{
    benchmark_done = true;
}

static void __exit_with_error(int error, const char *file, const char *func,
                  int line)
{
    fprintf(stderr, "%s:%s:%i: errno: %d/\"%s\"\n", file, func,
        line, error, strerror(error));
    exit(EXIT_FAILURE);
}

#define exit_with_error(error) __exit_with_error(error, __FILE__, __func__, __LINE__)

static void xdpsock_cleanup(void)
{
    int i, cmd = CLOSE_CONN;

    dump_stats();
    for (i = 0; i < num_socks; i++)
        xsk_socket__delete(xsks[i]->xsk);
    (void)xsk_umem__delete(umem.umem);

    if (opt_reduced_cap) {
        if (write(sock, &cmd, sizeof(int)) < 0)
            exit_with_error(errno);
    }
}

static void swap_mac_addresses(void *data)
{
    struct ether_header *eth = (struct ether_header *)data;
    struct ether_addr *src_addr = (struct ether_addr *)&eth->ether_shost;
    struct ether_addr *dst_addr = (struct ether_addr *)&eth->ether_dhost;
    struct ether_addr tmp;

    tmp = *src_addr;
    *src_addr = *dst_addr;
    *dst_addr = tmp;
}

static void hex_dump(void *pkt, size_t length, u64 addr)
{
    const unsigned char *address = (unsigned char *)pkt;
    const unsigned char *line = address;
    size_t line_size = 32;
    unsigned char c;
    char buf[32];
    int i = 0;

    if (!DEBUG_HEXDUMP)
        return;

    sprintf(buf, "addr=%llu", addr);
    printf("length = %zu\n", length);
    printf("%s | ", buf);
    while (length-- > 0) {
        printf("%02X ", *address++);
        if (!(++i % line_size) || (length == 0 && i % line_size)) {
            if (length == 0) {
                while (i++ % line_size)
                    printf("__ ");
            }
            printf(" | ");  /* right close */
            while (line < address) {
                c = *line++;
                printf("%c", (c < 33 || c == 255) ? 0x2E : c);
            }
            printf("\n");
            if (length > 0)
                printf("%s | ", buf);
        }
    }
    printf("\n");
}

static void *memset32_htonl(void *dest, u32 val, u32 size)
{
    u32 *ptr = (u32 *)dest;
    int i;

    val = htonl(val);

    for (i = 0; i < (size & (~0x3)); i += 4)
        ptr[i >> 2] = val;

    for (; i < size; i++)
        ((char *)dest)[i] = ((char *)&val)[i & 3];

    return dest;
}

/*
 * This function code has been taken from
 * Linux kernel lib/checksum.c
 */
static inline unsigned short from32to16(unsigned int x)
{
    /* add up 16-bit and 16-bit for 16+c bit */
    x = (x & 0xffff) + (x >> 16);
    /* add up carry.. */
    x = (x & 0xffff) + (x >> 16);
    return x;
}

/*
 * This function code has been taken from
 * Linux kernel lib/checksum.c
 */
static unsigned int do_csum(const unsigned char *buff, int len)
{
    unsigned int result = 0;
    int odd;

    if (len <= 0)
        goto out;
    odd = 1 & (unsigned long)buff;
    if (odd) {
#ifdef __LITTLE_ENDIAN
        result += (*buff << 8);
#else
        result = *buff;
#endif
        len--;
        buff++;
    }
    if (len >= 2) {
        if (2 & (unsigned long)buff) {
            result += *(unsigned short *)buff;
            len -= 2;
            buff += 2;
        }
        if (len >= 4) {
            const unsigned char *end = buff +
                           ((unsigned int)len & ~3);
            unsigned int carry = 0;

            do {
                unsigned int w = *(unsigned int *)buff;

                buff += 4;
                result += carry;
                result += w;
                carry = (w > result);
            } while (buff < end);
            result += carry;
            result = (result & 0xffff) + (result >> 16);
        }
        if (len & 2) {
            result += *(unsigned short *)buff;
            buff += 2;
        }
    }
    if (len & 1)
#ifdef __LITTLE_ENDIAN
        result += *buff;
#else
        result += (*buff << 8);
#endif
    result = from32to16(result);
    if (odd)
        result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
out:
    return result;
}

__sum16 ip_fast_csum(const void *iph, unsigned int ihl);

/*
 *  This is a version of ip_compute_csum() optimized for IP headers,
 *  which always checksum on 4 octet boundaries.
 *  This function code has been taken from
 *  Linux kernel lib/checksum.c
 */
__sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
    return (__force __sum16)~do_csum(iph, ihl * 4);
}

/*
 * Fold a partial checksum
 * This function code has been taken from
 * Linux kernel include/asm-generic/checksum.h
 */
static inline __sum16 csum_fold(__wsum csum)
{
    u32 sum = (__force u32)csum;

    sum = (sum & 0xffff) + (sum >> 16);
    sum = (sum & 0xffff) + (sum >> 16);
    return (__force __sum16)~sum;
}

/*
 * This function code has been taken from
 * Linux kernel lib/checksum.c
 */
static inline u32 from64to32(u64 x)
{
    /* add up 32-bit and 32-bit for 32+c bit */
    x = (x & 0xffffffff) + (x >> 32);
    /* add up carry.. */
    x = (x & 0xffffffff) + (x >> 32);
    return (u32)x;
}

__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
              __u32 len, __u8 proto, __wsum sum);

/*
 * This function code has been taken from
 * Linux kernel lib/checksum.c
 */
__wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
              __u32 len, __u8 proto, __wsum sum)
{
    unsigned long long s = (__force u32)sum;

    s += (__force u32)saddr;
    s += (__force u32)daddr;
#ifdef __BIG_ENDIAN__
    s += proto + len;
#else
    s += (proto + len) << 8;
#endif
    return (__force __wsum)from64to32(s);
}

/*
 * This function has been taken from
 * Linux kernel include/asm-generic/checksum.h
 */
static inline __sum16
csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
          __u8 proto, __wsum sum)
{
    return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
}

static inline u16 udp_csum(u32 saddr, u32 daddr, u32 len,
               u8 proto, u16 *udp_pkt)
{
    u32 csum = 0;
    u32 cnt = 0;

    /* udp hdr and data */
    for (; cnt < len; cnt += 2)
        csum += udp_pkt[cnt >> 1];

    return csum_tcpudp_magic(saddr, daddr, len, proto, csum);
}

#define ETH_FCS_SIZE 4

#define PKT_HDR_SIZE (sizeof(struct ethhdr) + sizeof(struct iphdr) + \
              sizeof(struct udphdr))

#define PKT_SIZE        (opt_pkt_size - ETH_FCS_SIZE)
#define IP_PKT_SIZE     (PKT_SIZE - sizeof(struct ethhdr))
#define UDP_PKT_SIZE        (IP_PKT_SIZE - sizeof(struct iphdr))
#define UDP_PKT_DATA_SIZE   (UDP_PKT_SIZE - sizeof(struct udphdr))

static u8 pkt_data[XSK_UMEM__DEFAULT_FRAME_SIZE];

static void gen_eth_hdr_data(void)
{
    struct udphdr *udp_hdr = (struct udphdr *)(pkt_data +
                           sizeof(struct ethhdr) +
                           sizeof(struct iphdr));
    struct iphdr *ip_hdr = (struct iphdr *)(pkt_data +
                        sizeof(struct ethhdr));
    struct ethhdr *eth_hdr = (struct ethhdr *)pkt_data;

    /* ethernet header */
    memcpy(eth_hdr->h_dest, "\x3c\xfd\xfe\x9e\x7f\x71", ETH_ALEN);
    memcpy(eth_hdr->h_source, "\xec\xb1\xd7\x98\x3a\xc0", ETH_ALEN);
    eth_hdr->h_proto = htons(ETH_P_IP);

    /* IP header */
    ip_hdr->version = IPVERSION;
    ip_hdr->ihl = 0x5; /* 20 byte header */
    ip_hdr->tos = 0x0;
    ip_hdr->tot_len = htons(IP_PKT_SIZE);
    ip_hdr->id = 0;
    ip_hdr->frag_off = 0;
    ip_hdr->ttl = IPDEFTTL;
    ip_hdr->protocol = IPPROTO_UDP;
    ip_hdr->saddr = htonl(0x0a0a0a10);
    ip_hdr->daddr = htonl(0x0a0a0a20);

    /* IP header checksum */
    ip_hdr->check = 0;
    ip_hdr->check = ip_fast_csum((const void *)ip_hdr, ip_hdr->ihl);

    /* UDP header */
    udp_hdr->source = htons(0x1000);
    udp_hdr->dest = htons(0x1000);
    udp_hdr->len = htons(UDP_PKT_SIZE);

    /* UDP data */
    memset32_htonl(pkt_data + PKT_HDR_SIZE, opt_pkt_fill_pattern,
               UDP_PKT_DATA_SIZE);

    /* UDP header checksum */
    udp_hdr->check = 0;
    udp_hdr->check = udp_csum(ip_hdr->saddr, ip_hdr->daddr, UDP_PKT_SIZE,
                  IPPROTO_UDP, (u16 *)udp_hdr);
}

static void gen_eth_frame(struct xsk_umem_info *umem, u64 addr)
{
    memcpy(xsk_umem__get_data(umem->buffer, addr), pkt_data,
           PKT_SIZE);
}

static void xsk_configure_umem(struct xsk_umem_info *umem,
                               void *buffer, u64 size)
{
    struct xsk_umem_config cfg = {
        /* We recommend that you set the fill ring size >= HW RX ring size +
         * AF_XDP RX ring size. Make sure you fill up the fill ring
         * with buffers at regular intervals, and you will with this setting
         * avoid allocation failures in the driver. These are usually quite
         * expensive since drivers have not been written to assume that
         * allocation failures are common. For regular sockets, kernel
         * allocated memory is used that only runs out in OOM situations
         * that should be rare.
         */
        .fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS * 2,
        .comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS,
        .frame_size = opt_xsk_frame_size,
        .frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM,
        .flags = opt_umem_flags
    };
    int ret;

    /* Use the queues of the first port (always present) for umem init */
    ret = xsk_umem__create(&umem->umem, buffer, size, &ports[0].fq,
                           &ports[0].cq, &cfg);
    if (ret)
        exit_with_error(-ret);

    umem->buffer = buffer;
}

static void xsk_populate_fill_ring(struct xsk_port_info *port, int start)
{
    int ret, i;
    u32 idx;

    ret = xsk_ring_prod__reserve(&port->fq,
                     XSK_RING_PROD__DEFAULT_NUM_DESCS * 2, &idx);
    if (ret != XSK_RING_PROD__DEFAULT_NUM_DESCS * 2)
        exit_with_error(-ret);
    for (i = 0; i < XSK_RING_PROD__DEFAULT_NUM_DESCS * 2; i++)
        *xsk_ring_prod__fill_addr(&port->fq, idx++) =
            (start + i) * opt_xsk_frame_size;
    xsk_ring_prod__submit(&port->fq, XSK_RING_PROD__DEFAULT_NUM_DESCS * 2);
}

static struct xsk_socket_info *xsk_configure_socket(struct xsk_port_info *port,
                                                    bool rx, bool tx)
{
    struct xsk_socket_config cfg;
    struct xsk_socket_info *xsk;
    struct xsk_ring_cons *rxr;
    struct xsk_ring_prod *txr;
    int ret;

    xsk = calloc(1, sizeof(*xsk));
    if (!xsk)
        exit_with_error(errno);

    xsk->port = port;
    cfg.rx_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
    cfg.tx_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
    if (opt_num_xsks > 1 || opt_reduced_cap)
        cfg.libbpf_flags = XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD;
    else
        cfg.libbpf_flags = 0;
    cfg.xdp_flags = opt_xdp_flags;
    cfg.bind_flags = opt_xdp_bind_flags;

    rxr = rx ? &xsk->rx : NULL;
    txr = tx ? &xsk->tx : NULL;
    ret = xsk_socket__create_shared(&xsk->xsk, port->ifname, port->queue,
                                    port->umem->umem, rxr, txr, &port->fq,
                                    &port->cq, &cfg);
    if (ret)
        exit_with_error(-ret);

    xsk->app_stats.rx_empty_polls = 0;
    xsk->app_stats.fill_fail_polls = 0;
    xsk->app_stats.copy_tx_sendtos = 0;
    xsk->app_stats.tx_wakeup_sendtos = 0;
    xsk->app_stats.opt_polls = 0;
    xsk->app_stats.prev_rx_empty_polls = 0;
    xsk->app_stats.prev_fill_fail_polls = 0;
    xsk->app_stats.prev_copy_tx_sendtos = 0;
    xsk->app_stats.prev_tx_wakeup_sendtos = 0;
    xsk->app_stats.prev_opt_polls = 0;

    return xsk;
}

static struct option long_options[] = {
    {"rxdrop", no_argument, 0, 'r'},
    {"txonly", no_argument, 0, 't'},
    {"l2fwd", no_argument, 0, 'l'},
    {"iface", required_argument, 0, 'i'},
    {"queue", required_argument, 0, 'q'},
    {"poll", no_argument, 0, 'p'},
    {"xdp-skb", no_argument, 0, 'S'},
    {"xdp-native", no_argument, 0, 'N'},
    {"interval", required_argument, 0, 'n'},
    {"zero-copy", no_argument, 0, 'z'},
    {"copy", no_argument, 0, 'c'},
    {"frame-size", required_argument, 0, 'f'},
    {"no-need-wakeup", no_argument, 0, 'm'},
    {"unaligned", no_argument, 0, 'u'},
    {"shared-umem", no_argument, 0, 'M'},
    {"force", no_argument, 0, 'F'},
    {"duration", required_argument, 0, 'd'},
    {"batch-size", required_argument, 0, 'b'},
    {"tx-pkt-count", required_argument, 0, 'C'},
    {"tx-pkt-size", required_argument, 0, 's'},
    {"tx-pkt-pattern", required_argument, 0, 'P'},
    {"extra-stats", no_argument, 0, 'x'},
    {"quiet", no_argument, 0, 'Q'},
    {"app-stats", no_argument, 0, 'a'},
    {"irq-string", no_argument, 0, 'I'},
    {"busy-poll", no_argument, 0, 'B'},
    {"reduce-cap", no_argument, 0, 'R'},
    {0, 0, 0, 0}
};

static void usage(const char *prog)
{
    const char *str =
        "  Usage: %s [OPTIONS]\n"
        "  Options:\n"
        "  -r, --rxdrop     Discard all incoming packets (default)\n"
        "  -t, --txonly     Only send packets\n"
        "  -l, --l2fwd      MAC swap L2 forwarding\n"
        "  -i, --iface=if[:q]   Run on interface if and queue q\n"
        "           (up to %d interfaces can be specified for the l2fwd benchmark)\n"
        "           (default queue 0)\n"
        "  -p, --poll       Use poll syscall\n"
        "  -S, --xdp-skb=n  Use XDP skb-mod\n"
        "  -N, --xdp-native=n   Enforce XDP native mode\n"
        "  -n, --interval=n Specify statistics update interval (default 1 sec).\n"
        "  -z, --zero-copy      Force zero-copy mode.\n"
        "  -c, --copy           Force copy mode.\n"
        "  -m, --no-need-wakeup Turn off use of driver need wakeup flag.\n"
        "  -f, --frame-size=n   Set the frame size (must be a power of two in aligned mode, default is %d).\n"
        "  -u, --unaligned  Enable unaligned chunk placement\n"
        "  -M, --shared-umem    Enable XDP_SHARED_UMEM (cannot be used with -R)\n"
        "  -F, --force      Force loading the XDP prog\n"
        "  -d, --duration=n Duration in secs to run command.\n"
        "           Default: forever.\n"
        "  -b, --batch-size=n   Batch size for sending or receiving\n"
        "           packets. Default: %d\n"
        "  -C, --tx-pkt-count=n Number of packets to send.\n"
        "           Default: Continuous packets.\n"
        "  -s, --tx-pkt-size=n  Transmit packet size.\n"
        "           (Default: %d bytes)\n"
        "           Min size: %d, Max size %d.\n"
        "  -P, --tx-pkt-pattern=nPacket fill pattern. Default: 0x%x\n"
        "  -x, --extra-stats    Display extra statistics.\n"
        "  -Q, --quiet          Do not display any stats.\n"
        "  -a, --app-stats  Display application (syscall) statistics.\n"
        "  -I, --irq-string Display driver interrupt statistics for interface associated with irq-string.\n"
        "  -B, --busy-poll      Busy poll.\n"
        "  -R, --reduce-cap Use reduced capabilities (cannot be used with -M)\n"
        "\n";
    fprintf(stderr, str, prog, MAX_PORTS, XSK_UMEM__DEFAULT_FRAME_SIZE,
        opt_batch_size, MIN_PKT_SIZE, MIN_PKT_SIZE,
        XSK_UMEM__DEFAULT_FRAME_SIZE, opt_pkt_fill_pattern);

    exit(EXIT_FAILURE);
}

static void parse_command_line(int argc, char **argv)
{
    int option_index, c;

    opterr = 0;

    for (;;) {
        c = getopt_long(argc, argv, "Frtli:pSNn:czf:muMd:b:C:s:P:xQaI:BR",
                long_options, &option_index);
        if (c == -1)
            break;

        switch (c) {
        case 'r':
            opt_bench = BENCH_RXDROP;
            break;
        case 't':
            opt_bench = BENCH_TXONLY;
            break;
        case 'l':
            opt_bench = BENCH_L2FWD;
            break;
        case 'i':
            if (opt_num_ports >= MAX_PORTS) {
                fprintf(stderr, "ERROR: at most %d interfaces are supported\n",
                    MAX_PORTS);
                usage(basename(argv[0]));
            }
            for (int i = 0; optarg[i] != 0; i++) {
                if (optarg[i] == ':') {
                    optarg[i] = 0;
                    ports[opt_num_ports].queue = atoi(optarg + i + 1);
                    break;
                }
            }
            ports[opt_num_ports].ifname = optarg;
            opt_num_ports++;
            break;
        case 'p':
            opt_poll = 1;
            break;
        case 'S':
            opt_xdp_flags |= XDP_FLAGS_SKB_MODE;
            opt_xdp_bind_flags |= XDP_COPY;
            break;
        case 'N':
            /* default, set below */
            break;
        case 'n':
            opt_interval = atoi(optarg);
            break;
        case 'z':
            opt_xdp_bind_flags |= XDP_ZEROCOPY;
            break;
        case 'c':
            opt_xdp_bind_flags |= XDP_COPY;
            break;
        case 'u':
            opt_umem_flags |= XDP_UMEM_UNALIGNED_CHUNK_FLAG;
            opt_unaligned_chunks = 1;
            opt_mmap_flags = MAP_HUGETLB;
            break;
        case 'F':
            opt_xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
            break;
        case 'f':
            opt_xsk_frame_size = atoi(optarg);
            break;
        case 'm':
            opt_need_wakeup = false;
            opt_xdp_bind_flags &= ~XDP_USE_NEED_WAKEUP;
            break;
        case 'M':
            opt_num_xsks = MAX_SOCKS;
            break;
        case 'd':
            opt_duration = atoi(optarg);
            opt_duration *= 1000000000;
            break;
        case 'b':
            opt_batch_size = atoi(optarg);
            break;
        case 'C':
            opt_pkt_count = atoi(optarg);
            break;
        case 's':
            opt_pkt_size = atoi(optarg);
            if (opt_pkt_size > (XSK_UMEM__DEFAULT_FRAME_SIZE) ||
                opt_pkt_size < MIN_PKT_SIZE) {
                fprintf(stderr,
                    "ERROR: Invalid frame size %d\n",
                    opt_pkt_size);
                usage(basename(argv[0]));
            }
            break;
        case 'P':
            opt_pkt_fill_pattern = strtol(optarg, NULL, 16);
            break;
        case 'x':
            opt_extra_stats = 1;
            break;
        case 'Q':
            opt_quiet = 1;
            break;
        case 'a':
            opt_app_stats = 1;
            break;
        case 'I':
            opt_irq_str = optarg;
            if (get_interrupt_number())
                irqs_at_init = get_irqs();
            if (irqs_at_init < 0) {
                fprintf(stderr, "ERROR: Failed to get irqs for %s\n", opt_irq_str);
                usage(basename(argv[0]));
            }
            break;
        case 'B':
            opt_busy_poll = 1;
            break;
        case 'R':
            opt_reduced_cap = true;
            break;
        default:
            usage(basename(argv[0]));
        }
    }

    if (!(opt_xdp_flags & XDP_FLAGS_SKB_MODE))
        opt_xdp_flags |= XDP_FLAGS_DRV_MODE;

    if (opt_num_ports > 1 && opt_bench != BENCH_L2FWD) {
        fprintf(stderr, "ERROR: multiple interfaces are only supported for the "
                "l2fwd benchmark\n");
        usage(basename(argv[0]));
    }

    for (int i = 0; i < opt_num_ports; i++) {
        ports[i].ifindex = if_nametoindex(ports[i].ifname);
        if (!ports[i].ifindex) {
            fprintf(stderr, "ERROR: interface \"%s\" does not exist\n",
                ports[i].ifname);
            usage(basename(argv[0]));
        }
    }

    if (opt_num_xsks == MAX_SOCKS) {
        opt_num_xsks /= opt_num_ports;
    }

    if ((opt_xsk_frame_size & (opt_xsk_frame_size - 1)) &&
        !opt_unaligned_chunks) {
        fprintf(stderr, "--frame-size=%d is not a power of two\n",
            opt_xsk_frame_size);
        usage(basename(argv[0]));
    }

    if (opt_reduced_cap && opt_num_xsks > 1) {
        fprintf(stderr, "ERROR: -M and -R cannot be used together\n");
        usage(basename(argv[0]));
    }
}

static void kick_tx(struct xsk_socket_info *xsk)
{
    int ret;

    ret = sendto(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, 0);
    if (ret >= 0 || errno == ENOBUFS || errno == EAGAIN ||
        errno == EBUSY || errno == ENETDOWN)
        return;
    exit_with_error(errno);
}

static inline void complete_tx_l2fwd(struct xsk_socket_info *complete_xsk,
                                     struct xsk_socket_info *fill_xsk)
{
    struct xsk_port_info *complete_port = complete_xsk->port;
    struct xsk_port_info *fill_port = fill_xsk->port;
    u32 idx_cq = 0, idx_fq = 0;
    unsigned int rcvd;
    size_t ndescs;

    if (!complete_xsk->outstanding_tx)
        return;

    /* In copy mode, Tx is driven by a syscall so we need to use e.g. sendto() to
     * really send the packets. In zero-copy mode we do not have to do this, since Tx
     * is driven by the NAPI loop. So as an optimization, we do not have to call
     * sendto() all the time in zero-copy mode for l2fwd.
     */
    if (opt_xdp_bind_flags & XDP_COPY) {
        complete_xsk->app_stats.copy_tx_sendtos++;
        kick_tx(complete_xsk);
    }

    ndescs = (complete_xsk->outstanding_tx > opt_batch_size) ? opt_batch_size :
        complete_xsk->outstanding_tx;

    /* re-add completed Tx buffers */
    rcvd = xsk_ring_cons__peek(&complete_port->cq, ndescs, &idx_cq);
    if (rcvd > 0) {
        unsigned int i;
        int ret;

        ret = xsk_ring_prod__reserve(&fill_port->fq, rcvd, &idx_fq);
        while (ret != rcvd) {
            if (ret < 0)
                exit_with_error(-ret);
            if (opt_busy_poll || xsk_ring_prod__needs_wakeup(&fill_port->fq)) {
                fill_xsk->app_stats.fill_fail_polls++;
                recvfrom(xsk_socket__fd(fill_xsk->xsk), NULL, 0, MSG_DONTWAIT,
                         NULL, NULL);
            }
            ret = xsk_ring_prod__reserve(&fill_port->fq, rcvd, &idx_fq);
        }

        for (i = 0; i < rcvd; i++)
            *xsk_ring_prod__fill_addr(&fill_port->fq, idx_fq++) =
                *xsk_ring_cons__comp_addr(&complete_port->cq, idx_cq++);

        xsk_ring_prod__submit(&fill_port->fq, rcvd);
        xsk_ring_cons__release(&complete_port->cq, rcvd);
        complete_xsk->outstanding_tx -= rcvd;
    }
}

static inline void complete_tx_only(struct xsk_socket_info *xsk,
                    int batch_size)
{
    unsigned int rcvd;
    u32 idx;

    if (!xsk->outstanding_tx)
        return;

    if (!opt_need_wakeup || xsk_ring_prod__needs_wakeup(&xsk->tx)) {
        xsk->app_stats.tx_wakeup_sendtos++;
        kick_tx(xsk);
    }

    rcvd = xsk_ring_cons__peek(&xsk->port->cq, batch_size, &idx);
    if (rcvd > 0) {
        xsk_ring_cons__release(&xsk->port->cq, rcvd);
        xsk->outstanding_tx -= rcvd;
    }
}

static void rx_drop(struct xsk_socket_info *xsk)
{
    unsigned int rcvd, i;
    u32 idx_rx = 0, idx_fq = 0;
    int ret;

    rcvd = xsk_ring_cons__peek(&xsk->rx, opt_batch_size, &idx_rx);
    if (!rcvd) {
        if (opt_busy_poll || xsk_ring_prod__needs_wakeup(&xsk->port->fq)) {
            xsk->app_stats.rx_empty_polls++;
            recvfrom(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, NULL);
        }
        return;
    }

    ret = xsk_ring_prod__reserve(&xsk->port->fq, rcvd, &idx_fq);
    while (ret != rcvd) {
        if (ret < 0)
            exit_with_error(-ret);
        if (opt_busy_poll || xsk_ring_prod__needs_wakeup(&xsk->port->fq)) {
            xsk->app_stats.fill_fail_polls++;
            recvfrom(xsk_socket__fd(xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL, NULL);
        }
        ret = xsk_ring_prod__reserve(&xsk->port->fq, rcvd, &idx_fq);
    }

    for (i = 0; i < rcvd; i++) {
        u64 addr = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx)->addr;
        u32 len = xsk_ring_cons__rx_desc(&xsk->rx, idx_rx++)->len;
        u64 orig = xsk_umem__extract_addr(addr);

        addr = xsk_umem__add_offset_to_addr(addr);
        char *pkt = xsk_umem__get_data(xsk->port->umem->buffer, addr);

        swap_mac_addresses(pkt);

        hex_dump(pkt, len, addr);
        *xsk_ring_prod__fill_addr(&xsk->port->fq, idx_fq++) = orig;
    }

    xsk_ring_prod__submit(&xsk->port->fq, rcvd);
    xsk_ring_cons__release(&xsk->rx, rcvd);
    xsk->ring_stats.rx_npkts += rcvd;
}

static void rx_drop_all(void)
{
    struct pollfd fds[MAX_SOCKS] = {};
    int i, ret;

    for (i = 0; i < num_socks; i++) {
        fds[i].fd = xsk_socket__fd(xsks[i]->xsk);
        fds[i].events = POLLIN;
    }

    for (;;) {
        if (opt_poll) {
            for (i = 0; i < num_socks; i++)
                xsks[i]->app_stats.opt_polls++;
            ret = poll(fds, num_socks, opt_timeout);
            if (ret <= 0)
                continue;
        }

        for (i = 0; i < num_socks; i++)
            rx_drop(xsks[i]);

        if (benchmark_done)
            break;
    }
}

static void tx_only(struct xsk_socket_info *xsk, u32 *frame_nb, int batch_size)
{
    u32 idx;
    unsigned int i;

    while (xsk_ring_prod__reserve(&xsk->tx, batch_size, &idx) <
                      batch_size) {
        complete_tx_only(xsk, batch_size);
        if (benchmark_done)
            return;
    }

    for (i = 0; i < batch_size; i++) {
        struct xdp_desc *tx_desc = xsk_ring_prod__tx_desc(&xsk->tx,
                                  idx + i);
        tx_desc->addr = (*frame_nb + i) * opt_xsk_frame_size;
        tx_desc->len = PKT_SIZE;
    }

    xsk_ring_prod__submit(&xsk->tx, batch_size);
    xsk->ring_stats.tx_npkts += batch_size;
    xsk->outstanding_tx += batch_size;
    *frame_nb += batch_size;
    *frame_nb %= NUM_FRAMES;
    complete_tx_only(xsk, batch_size);
}

static inline int get_batch_size(int pkt_cnt)
{
    if (!opt_pkt_count)
        return opt_batch_size;

    if (pkt_cnt + opt_batch_size <= opt_pkt_count)
        return opt_batch_size;

    return opt_pkt_count - pkt_cnt;
}

static void complete_tx_only_all(void)
{
    bool pending;
    int i;

    do {
        pending = false;
        for (i = 0; i < num_socks; i++) {
            if (xsks[i]->outstanding_tx) {
                complete_tx_only(xsks[i], opt_batch_size);
                pending = !!xsks[i]->outstanding_tx;
            }
        }
    } while (pending);
}

static void tx_only_all(void)
{
    struct pollfd fds[MAX_SOCKS] = {};
    u32 frame_nb[MAX_SOCKS] = {};
    int pkt_cnt = 0;
    int i, ret;

    for (i = 0; i < num_socks; i++) {
        fds[0].fd = xsk_socket__fd(xsks[i]->xsk);
        fds[0].events = POLLOUT;
    }

    while ((opt_pkt_count && pkt_cnt < opt_pkt_count) || !opt_pkt_count) {
        int batch_size = get_batch_size(pkt_cnt);

        if (opt_poll) {
            for (i = 0; i < num_socks; i++)
                xsks[i]->app_stats.opt_polls++;
            ret = poll(fds, num_socks, opt_timeout);
            if (ret <= 0)
                continue;

            if (!(fds[0].revents & POLLOUT))
                continue;
        }

        for (i = 0; i < num_socks; i++)
            tx_only(xsks[i], &frame_nb[i], batch_size);

        pkt_cnt += batch_size;

        if (benchmark_done)
            break;
    }

    if (opt_pkt_count)
        complete_tx_only_all();
}

static void l2fwd(struct xsk_socket_info *rx_xsk,
                  struct xsk_socket_info *tx_xsk)
{
    unsigned int rcvd, i;
    u32 idx_rx = 0, idx_tx = 0;
    int ret;

    complete_tx_l2fwd(tx_xsk, rx_xsk);

    rcvd = xsk_ring_cons__peek(&rx_xsk->rx, opt_batch_size, &idx_rx);
    if (!rcvd) {
        if (opt_busy_poll || xsk_ring_prod__needs_wakeup(&rx_xsk->port->fq)) {
            rx_xsk->app_stats.rx_empty_polls++;
            recvfrom(xsk_socket__fd(rx_xsk->xsk), NULL, 0, MSG_DONTWAIT, NULL,
                     NULL);
        }
        return;
    }
    rx_xsk->ring_stats.rx_npkts += rcvd;

    ret = xsk_ring_prod__reserve(&tx_xsk->tx, rcvd, &idx_tx);
    while (ret != rcvd) {
        if (ret < 0)
            exit_with_error(-ret);
        complete_tx_l2fwd(tx_xsk, rx_xsk);
        if (opt_busy_poll || xsk_ring_prod__needs_wakeup(&tx_xsk->tx)) {
            tx_xsk->app_stats.tx_wakeup_sendtos++;
            kick_tx(tx_xsk);
        }
        ret = xsk_ring_prod__reserve(&tx_xsk->tx, rcvd, &idx_tx);
    }

    for (i = 0; i < rcvd; i++) {
        u64 addr = xsk_ring_cons__rx_desc(&rx_xsk->rx, idx_rx)->addr;
        u32 len = xsk_ring_cons__rx_desc(&rx_xsk->rx, idx_rx++)->len;
        u64 orig = addr;

        addr = xsk_umem__add_offset_to_addr(addr);
        char *pkt = xsk_umem__get_data(rx_xsk->port->umem->buffer, addr);

        swap_mac_addresses(pkt);

        hex_dump(pkt, len, addr);
        xsk_ring_prod__tx_desc(&tx_xsk->tx, idx_tx)->addr = orig;
        xsk_ring_prod__tx_desc(&tx_xsk->tx, idx_tx++)->len = len;
    }

    xsk_ring_prod__submit(&tx_xsk->tx, rcvd);
    xsk_ring_cons__release(&rx_xsk->rx, rcvd);

    tx_xsk->ring_stats.tx_npkts += rcvd;
    tx_xsk->outstanding_tx += rcvd;
}

static void l2fwd_all(void)
{
    struct pollfd fds[MAX_SOCKS] = {};
    int i, ret;

    for (;;) {
        if (opt_poll) {
            for (i = 0; i < num_socks; i++) {
                fds[i].fd = xsk_socket__fd(xsks[i]->xsk);
                fds[i].events = POLLIN;
                xsks[i]->app_stats.opt_polls++;
            }
            ret = poll(fds, num_socks, opt_timeout);
            if (ret <= 0)
                continue;
        }

        for (i = 0; i < num_socks; i++)
            l2fwd(xsks[i], xsks[(i + 1) % num_socks]);

        if (benchmark_done)
            break;
    }
}

static void load_xdp_program(char **argv, struct bpf_object **obj)
{
    struct bpf_prog_load_attr prog_load_attr = {
        .prog_type      = BPF_PROG_TYPE_XDP,
    };
    char xdp_filename[256];
    int prog_fd;

    snprintf(xdp_filename, sizeof(xdp_filename), "%s_kern.o", argv[0]);
    prog_load_attr.file = xdp_filename;

    if (bpf_prog_load_xattr(&prog_load_attr, obj, &prog_fd))
        exit(EXIT_FAILURE);
    if (prog_fd < 0) {
        fprintf(stderr, "ERROR: no program found: %s\n",
            strerror(prog_fd));
        exit(EXIT_FAILURE);
    }

    for (int i = 0; i < opt_num_ports; i++) {
        if (bpf_set_link_xdp_fd(ports[i].ifindex, prog_fd, opt_xdp_flags) < 0) {
            fprintf(stderr, "ERROR: link set xdp fd failed on %s\n",
                ports[i].ifname);
            exit(EXIT_FAILURE);
        }
    }
}

static void enter_xsks_into_map(struct bpf_object *obj)
{
    struct bpf_map *map;
    int i, xsks_map;

    map = bpf_object__find_map_by_name(obj, "xsks_map");
    xsks_map = bpf_map__fd(map);
    if (xsks_map < 0) {
        fprintf(stderr, "ERROR: no xsks map found: %s\n",
            strerror(xsks_map));
            exit(EXIT_FAILURE);
    }

    for (i = 0; i < num_socks; i++) {
        int fd = xsk_socket__fd(xsks[i]->xsk);
        int key, ret;

        key = i;
        ret = bpf_map_update_elem(xsks_map, &key, &fd, 0);
        if (ret) {
            fprintf(stderr, "ERROR: bpf_map_update_elem %d\n", i);
            exit(EXIT_FAILURE);
        }
    }
}

static void apply_setsockopt(struct xsk_socket_info *xsk)
{
    int sock_opt;

    if (!opt_busy_poll)
        return;

    sock_opt = 1;
    if (setsockopt(xsk_socket__fd(xsk->xsk), SOL_SOCKET, SO_PREFER_BUSY_POLL,
               (void *)&sock_opt, sizeof(sock_opt)) < 0)
        exit_with_error(errno);

    sock_opt = 20;
    if (setsockopt(xsk_socket__fd(xsk->xsk), SOL_SOCKET, SO_BUSY_POLL,
               (void *)&sock_opt, sizeof(sock_opt)) < 0)
        exit_with_error(errno);

    sock_opt = opt_batch_size;
    if (setsockopt(xsk_socket__fd(xsk->xsk), SOL_SOCKET, SO_BUSY_POLL_BUDGET,
               (void *)&sock_opt, sizeof(sock_opt)) < 0)
        exit_with_error(errno);
}

static int recv_xsks_map_fd_from_ctrl_node(int sock, int *_fd)
{
    char cms[CMSG_SPACE(sizeof(int))];
    struct cmsghdr *cmsg;
    struct msghdr msg;
    struct iovec iov;
    int value;
    int len;

    iov.iov_base = &value;
    iov.iov_len = sizeof(int);

    msg.msg_name = 0;
    msg.msg_namelen = 0;
    msg.msg_iov = &iov;
    msg.msg_iovlen = 1;
    msg.msg_flags = 0;
    msg.msg_control = (caddr_t)cms;
    msg.msg_controllen = sizeof(cms);

    len = recvmsg(sock, &msg, 0);

    if (len < 0) {
        fprintf(stderr, "Recvmsg failed length incorrect.\n");
        return -EINVAL;
    }

    if (len == 0) {
        fprintf(stderr, "Recvmsg failed no data\n");
        return -EINVAL;
    }

    cmsg = CMSG_FIRSTHDR(&msg);
    *_fd = *(int *)CMSG_DATA(cmsg);

    return 0;
}

static int
recv_xsks_map_fd(int *xsks_map_fd)
{
    struct sockaddr_un server;
    int err;

    sock = socket(AF_UNIX, SOCK_STREAM, 0);
    if (sock < 0) {
        fprintf(stderr, "Error opening socket stream: %s", strerror(errno));
        return errno;
    }

    server.sun_family = AF_UNIX;
    strcpy(server.sun_path, SOCKET_NAME);

    if (connect(sock, (struct sockaddr *)&server, sizeof(struct sockaddr_un)) < 0) {
        close(sock);
        fprintf(stderr, "Error connecting stream socket: %s", strerror(errno));
        return errno;
    }

    err = recv_xsks_map_fd_from_ctrl_node(sock, xsks_map_fd);
    if (err) {
        fprintf(stderr, "Error %d receiving fd\n", err);
        return err;
    }
    return 0;
}

int main(int argc, char **argv)
{
    struct __user_cap_header_struct hdr = { _LINUX_CAPABILITY_VERSION_3, 0 };
    struct __user_cap_data_struct data[2] = { { 0 } };
    bool rx = false, tx = false;
    struct bpf_object *obj;
    int xsks_map_fd = 0;
    pthread_t pt;
    int i, ret;
    void *bufs;

    parse_command_line(argc, argv);

    if (opt_reduced_cap) {
        if (capget(&hdr, data)  < 0)
            fprintf(stderr, "Error getting capabilities\n");

        data->effective &= CAP_TO_MASK(CAP_NET_RAW);
        data->permitted &= CAP_TO_MASK(CAP_NET_RAW);

        if (capset(&hdr, data) < 0)
            fprintf(stderr, "Setting capabilities failed\n");

        if (capget(&hdr, data)  < 0) {
            fprintf(stderr, "Error getting capabilities\n");
        } else {
            fprintf(stderr, "Capabilities EFF %x Caps INH %x Caps Per %x\n",
                data[0].effective, data[0].inheritable, data[0].permitted);
            fprintf(stderr, "Capabilities EFF %x Caps INH %x Caps Per %x\n",
                data[1].effective, data[1].inheritable, data[1].permitted);
        }
    } else {
        if (opt_num_xsks > 1)
            load_xdp_program(argv, &obj);
    }

    /* Reserve memory for the umem. Use hugepages if unaligned chunk mode */
    bufs = mmap(NULL, NUM_FRAMES * opt_xsk_frame_size * opt_num_ports,
            PROT_READ | PROT_WRITE,
            MAP_PRIVATE | MAP_ANONYMOUS | opt_mmap_flags, -1, 0);
    if (bufs == MAP_FAILED) {
        printf("ERROR: mmap failed\n");
        exit(EXIT_FAILURE);
    }

    /* Create sockets... */
    xsk_configure_umem(&umem, bufs,
                       NUM_FRAMES * opt_xsk_frame_size * opt_num_ports);
    for (i = 0; i < opt_num_ports; i++)
        ports[i].umem = &umem;

    if (opt_bench == BENCH_RXDROP || opt_bench == BENCH_L2FWD)
        rx = true;
    if (opt_bench == BENCH_L2FWD || opt_bench == BENCH_TXONLY)
        tx = true;

    for (i = 0; i < opt_num_xsks * opt_num_ports; i++) {
        xsks[num_socks++] = xsk_configure_socket(&ports[i % opt_num_ports], rx,
                                                 tx);
        apply_setsockopt(xsks[i]);
    }

    if (opt_bench == BENCH_RXDROP || opt_bench == BENCH_L2FWD) {
        for (i = 0; i < opt_num_ports; i++)
            xsk_populate_fill_ring(&ports[i], i * NUM_FRAMES);

    } else {
        gen_eth_hdr_data();

        for (i = 0; i < NUM_FRAMES; i++)
            gen_eth_frame(&umem, i * opt_xsk_frame_size);
    }

    if (opt_num_xsks > 1 && opt_bench != BENCH_TXONLY)
        enter_xsks_into_map(obj);

    if (opt_reduced_cap) {
        ret = recv_xsks_map_fd(&xsks_map_fd);
        if (ret) {
            fprintf(stderr, "Error %d receiving xsks_map_fd\n", ret);
            exit_with_error(ret);
        }
        if (xsks[0]->xsk) {
            ret = xsk_socket__update_xskmap(xsks[0]->xsk, xsks_map_fd);
            if (ret) {
                fprintf(stderr, "Update of BPF map failed(%d)\n", ret);
                exit_with_error(ret);
            }
        }
    }

    signal(SIGINT, int_exit);
    signal(SIGTERM, int_exit);
    signal(SIGABRT, int_exit);

    setlocale(LC_ALL, "");

    if (!opt_quiet) {
        ret = pthread_create(&pt, NULL, poller, NULL);
        if (ret)
            exit_with_error(ret);
    }

    prev_time = get_nsecs();
    start_time = prev_time;

    if (opt_bench == BENCH_RXDROP)
        rx_drop_all();
    else if (opt_bench == BENCH_TXONLY)
        tx_only_all();
    else
        l2fwd_all();

    benchmark_done = true;

    if (!opt_quiet)
        pthread_join(pt, NULL);

    xdpsock_cleanup();

    munmap(bufs, NUM_FRAMES * opt_xsk_frame_size);

    return 0;
}