examples/ptpclient/ptpclient.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2015 Intel Corporation
 */

/*
 * This application is a simple Layer 2 PTP v2 client. It shows delta values
 * which are used to synchronize the PHC clock. if the "-T 1" parameter is
 * passed to the application the Linux kernel clock is also synchronized.
 */

#include <stdint.h>
#include <stdlib.h>
#include <inttypes.h>
#include <rte_eal.h>
#include <rte_ethdev.h>
#include <rte_cycles.h>
#include <rte_lcore.h>
#include <rte_mbuf.h>
#include <rte_ip.h>
#include <limits.h>
#include <sys/time.h>
#include <getopt.h>
#include <signal.h>

static volatile bool force_quit;

#define RX_RING_SIZE 1024
#define TX_RING_SIZE 1024

#define NUM_MBUFS            8191
#define MBUF_CACHE_SIZE       250

/* Values for the PTP messageType field. */
#define SYNC                  0x0
#define DELAY_REQ             0x1
#define PDELAY_REQ            0x2
#define PDELAY_RESP           0x3
#define FOLLOW_UP             0x8
#define DELAY_RESP            0x9
#define PDELAY_RESP_FOLLOW_UP 0xA
#define ANNOUNCE              0xB
#define SIGNALING             0xC
#define MANAGEMENT            0xD

#define NSEC_PER_SEC        1000000000L
#define KERNEL_TIME_ADJUST_LIMIT  20000
#define PTP_PROTOCOL             0x88F7

#define KP 0.7
#define KI 0.3
#define FREQ_EST_MARGIN 0.001

enum servo_state {
    SERVO_UNLOCKED,
    SERVO_JUMP,
    SERVO_LOCKED,
};

struct pi_servo {
    double offset[2];
    double local[2];
    double drift;
    double last_freq;
    int count;

    double max_frequency;
    double step_threshold;
    double first_step_threshold;
    int first_update;
};

enum controller_mode {
    MODE_NONE,
    MODE_PI,
    MAX_ALL
} mode = MODE_NONE;

struct rte_mempool *mbuf_pool;
uint32_t ptp_enabled_port_mask;
uint8_t ptp_enabled_port_nb;
static uint8_t ptp_enabled_ports[RTE_MAX_ETHPORTS];

static const struct rte_ether_addr ether_multicast = {
    .addr_bytes = {0x01, 0x1b, 0x19, 0x0, 0x0, 0x0}
};

/* Structs used for PTP handling. */
struct tstamp {
    uint16_t   sec_msb;
    uint32_t   sec_lsb;
    uint32_t   ns;
}  __rte_packed;

struct clock_id {
    uint8_t id[8];
};

struct port_id {
    struct clock_id        clock_id;
    uint16_t               port_number;
}  __rte_packed;

struct ptp_header {
    uint8_t              msg_type;
    uint8_t              ver;
    uint16_t             message_length;
    uint8_t              domain_number;
    uint8_t              reserved1;
    uint8_t              flag_field[2];
    int64_t              correction;
    uint32_t             reserved2;
    struct port_id       source_port_id;
    uint16_t             seq_id;
    uint8_t              control;
    int8_t               log_message_interval;
} __rte_packed;

struct sync_msg {
    struct ptp_header   hdr;
    struct tstamp       origin_tstamp;
} __rte_packed;

struct follow_up_msg {
    struct ptp_header   hdr;
    struct tstamp       precise_origin_tstamp;
    uint8_t             suffix[];
} __rte_packed;

struct delay_req_msg {
    struct ptp_header   hdr;
    struct tstamp       origin_tstamp;
} __rte_packed;

struct delay_resp_msg {
    struct ptp_header    hdr;
    struct tstamp        rx_tstamp;
    struct port_id       req_port_id;
    uint8_t              suffix[];
} __rte_packed;

struct ptp_message {
    union {
        struct ptp_header          header;
        struct sync_msg            sync;
        struct delay_req_msg       delay_req;
        struct follow_up_msg       follow_up;
        struct delay_resp_msg      delay_resp;
    } __rte_packed;
};

struct ptpv2_time_receiver_ordinary {
    struct rte_mbuf *m;
    struct timespec tstamp1;
    struct timespec tstamp2;
    struct timespec tstamp3;
    struct timespec tstamp4;
    struct clock_id client_clock_id;
    struct clock_id transmitter_clock_id;
    struct timeval new_adj;
    int64_t delta;
    uint16_t portid;
    uint16_t seqID_SYNC;
    uint16_t seqID_FOLLOWUP;
    uint8_t ptpset;
    uint8_t kernel_time_set;
    uint16_t current_ptp_port;
    int64_t master_offset;
    int64_t path_delay;
    struct pi_servo *servo;
};

static struct ptpv2_time_receiver_ordinary ptp_data;

static inline uint64_t timespec64_to_ns(const struct timespec *ts)
{
    return ((uint64_t) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
}

static struct timeval
ns_to_timeval(int64_t nsec)
{
    struct timespec t_spec = {0, 0};
    struct timeval t_eval = {0, 0};
    int32_t rem;

    if (nsec == 0)
        return t_eval;
    rem = nsec % NSEC_PER_SEC;
    t_spec.tv_sec = nsec / NSEC_PER_SEC;

    if (rem < 0) {
        t_spec.tv_sec--;
        rem += NSEC_PER_SEC;
    }

    t_spec.tv_nsec = rem;
    t_eval.tv_sec = t_spec.tv_sec;
    t_eval.tv_usec = t_spec.tv_nsec / 1000;

    return t_eval;
}

/*
 * Initializes a given port using global settings and with the RX buffers
 * coming from the mbuf_pool passed as a parameter.
 */
static inline int
port_init(uint16_t port, struct rte_mempool *mbuf_pool)
{
    struct rte_eth_dev_info dev_info;
    struct rte_eth_conf port_conf;
    const uint16_t rx_rings = 1;
    const uint16_t tx_rings = 1;
    int retval;
    uint16_t q;
    uint16_t nb_rxd = RX_RING_SIZE;
    uint16_t nb_txd = TX_RING_SIZE;

    if (!rte_eth_dev_is_valid_port(port))
        return -1;

    memset(&port_conf, 0, sizeof(struct rte_eth_conf));

    retval = rte_eth_dev_info_get(port, &dev_info);
    if (retval != 0) {
        printf("Error during getting device (port %u) info: %s\n",
                port, strerror(-retval));

        return retval;
    }

    if (dev_info.rx_offload_capa & RTE_ETH_RX_OFFLOAD_TIMESTAMP)
        port_conf.rxmode.offloads |= RTE_ETH_RX_OFFLOAD_TIMESTAMP;

    if (dev_info.tx_offload_capa & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE)
        port_conf.txmode.offloads |=
            RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE;
    /* Force full Tx path in the driver, required for IEEE1588 */
    port_conf.txmode.offloads |= RTE_ETH_TX_OFFLOAD_MULTI_SEGS;

    /* Configure the Ethernet device. */
    retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
    if (retval != 0)
        return retval;

    retval = rte_eth_dev_adjust_nb_rx_tx_desc(port, &nb_rxd, &nb_txd);
    if (retval != 0)
        return retval;

    /* Allocate and set up 1 RX queue per Ethernet port. */
    for (q = 0; q < rx_rings; q++) {
        struct rte_eth_rxconf *rxconf;

        rxconf = &dev_info.default_rxconf;
        rxconf->offloads = port_conf.rxmode.offloads;

        retval = rte_eth_rx_queue_setup(port, q, nb_rxd,
                rte_eth_dev_socket_id(port), rxconf, mbuf_pool);

        if (retval < 0)
            return retval;
    }

    /* Allocate and set up 1 TX queue per Ethernet port. */
    for (q = 0; q < tx_rings; q++) {
        struct rte_eth_txconf *txconf;

        txconf = &dev_info.default_txconf;
        txconf->offloads = port_conf.txmode.offloads;

        retval = rte_eth_tx_queue_setup(port, q, nb_txd,
                rte_eth_dev_socket_id(port), txconf);
        if (retval < 0)
            return retval;
    }

    /* Start the Ethernet port. */
    retval = rte_eth_dev_start(port);
    if (retval < 0)
        return retval;

    /* Enable timesync timestamping for the Ethernet device */
    retval = rte_eth_timesync_enable(port);
    if (retval < 0) {
        printf("Timesync enable failed: %d\n", retval);
        return retval;
    }

    /* Enable RX in promiscuous mode for the Ethernet device. */
    retval = rte_eth_promiscuous_enable(port);
    if (retval != 0) {
        printf("Promiscuous mode enable failed: %s\n",
            rte_strerror(-retval));
        return retval;
    }

    /*
     * If the clock servo controller is enabled, the PMD must support
     * adjustment of the clock frequency.
     */
    if (mode != MODE_NONE) {
        retval = rte_eth_timesync_adjust_freq(port, 0);
        if (retval == -ENOTSUP) {
            printf("The servo controller cannot work on devices that"
                    " do not support frequency adjustment.\n");
            return retval;
        }
    }

    return 0;
}

static void
print_clock_info(struct ptpv2_time_receiver_ordinary *ptp_data)
{
    int64_t nsec;
    struct timespec net_time, sys_time;

    printf("time transmitter clock id: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
        ptp_data->transmitter_clock_id.id[0],
        ptp_data->transmitter_clock_id.id[1],
        ptp_data->transmitter_clock_id.id[2],
        ptp_data->transmitter_clock_id.id[3],
        ptp_data->transmitter_clock_id.id[4],
        ptp_data->transmitter_clock_id.id[5],
        ptp_data->transmitter_clock_id.id[6],
        ptp_data->transmitter_clock_id.id[7]);

    printf("\nT2 - time receiver clock.  %lds %ldns",
            (ptp_data->tstamp2.tv_sec),
            (ptp_data->tstamp2.tv_nsec));

    printf("\nT1 - time transmitter clock.  %lds %ldns ",
            ptp_data->tstamp1.tv_sec,
            (ptp_data->tstamp1.tv_nsec));

    printf("\nT3 - time receiver clock.  %lds %ldns",
            ptp_data->tstamp3.tv_sec,
            (ptp_data->tstamp3.tv_nsec));

    printf("\nT4 - time transmitter clock.  %lds %ldns\n",
            ptp_data->tstamp4.tv_sec,
            (ptp_data->tstamp4.tv_nsec));

    if (mode == MODE_NONE) {
        printf("\nDelta between transmitter and receiver clocks:%"PRId64"ns\n",
            ptp_data->delta);

        clock_gettime(CLOCK_REALTIME, &sys_time);
        rte_eth_timesync_read_time(ptp_data->current_ptp_port,
                       &net_time);

        time_t ts = net_time.tv_sec;

        printf("\n\nComparison between Linux kernel Time and PTP:");

        printf("\nCurrent PTP Time: %.24s %.9ld ns",
            ctime(&ts), net_time.tv_nsec);

        nsec = (int64_t)timespec64_to_ns(&net_time) -
            (int64_t)timespec64_to_ns(&sys_time);
        ptp_data->new_adj = ns_to_timeval(nsec);

        gettimeofday(&ptp_data->new_adj, NULL);

        time_t tp = ptp_data->new_adj.tv_sec;

        printf("\nCurrent SYS Time: %.24s %.6ld ns",
            ctime(&tp), ptp_data->new_adj.tv_usec);

        printf("\nDelta between PTP and Linux Kernel time:%"PRId64"ns\n",
            nsec);
    }

    if (mode == MODE_PI) {
        printf("path delay: %"PRId64"ns\n", ptp_data->path_delay);
        printf("time transmitter offset: %"PRId64"ns\n", ptp_data->master_offset);
    }

    printf("[Ctrl+C to quit]\n");

    /* Clear screen and put cursor in column 1, row 1 */
    printf("\033[2J\033[1;1H");
}

static int64_t
delta_eval(struct ptpv2_time_receiver_ordinary *ptp_data)
{
    int64_t delta;
    uint64_t t1 = 0;
    uint64_t t2 = 0;
    uint64_t t3 = 0;
    uint64_t t4 = 0;

    t1 = timespec64_to_ns(&ptp_data->tstamp1);
    t2 = timespec64_to_ns(&ptp_data->tstamp2);
    t3 = timespec64_to_ns(&ptp_data->tstamp3);
    t4 = timespec64_to_ns(&ptp_data->tstamp4);

    delta = -((int64_t)((t2 - t1) - (t4 - t3))) / 2;

    return delta;
}

/*
 * Parse the PTP SYNC message.
 */
static void
parse_sync(struct ptpv2_time_receiver_ordinary *ptp_data, uint16_t rx_tstamp_idx)
{
    struct ptp_header *ptp_hdr;

    ptp_hdr = rte_pktmbuf_mtod_offset(ptp_data->m, struct ptp_header *,
                      sizeof(struct rte_ether_hdr));
    ptp_data->seqID_SYNC = rte_be_to_cpu_16(ptp_hdr->seq_id);

    if (ptp_data->ptpset == 0) {
        rte_memcpy(&ptp_data->transmitter_clock_id,
                &ptp_hdr->source_port_id.clock_id,
                sizeof(struct clock_id));
        ptp_data->ptpset = 1;
    }

    if (memcmp(&ptp_hdr->source_port_id.clock_id,
            &ptp_hdr->source_port_id.clock_id,
            sizeof(struct clock_id)) == 0) {

        if (ptp_data->ptpset == 1)
            rte_eth_timesync_read_rx_timestamp(ptp_data->portid,
                    &ptp_data->tstamp2, rx_tstamp_idx);
    }

}

/*
 * Parse the PTP FOLLOWUP message and send DELAY_REQ to the main clock.
 */
static void
parse_fup(struct ptpv2_time_receiver_ordinary *ptp_data)
{
    struct rte_ether_hdr *eth_hdr;
    struct rte_ether_addr eth_addr;
    struct ptp_header *ptp_hdr;
    struct clock_id *client_clkid;
    struct ptp_message *ptp_msg;
    struct delay_req_msg *req_msg;
    struct rte_mbuf *created_pkt;
    struct tstamp *origin_tstamp;
    struct rte_ether_addr eth_multicast = ether_multicast;
    size_t pkt_size;
    int wait_us;
    struct rte_mbuf *m = ptp_data->m;
    int ret;

    eth_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
    ptp_hdr = rte_pktmbuf_mtod_offset(m, struct ptp_header *,
                      sizeof(struct rte_ether_hdr));
    if (memcmp(&ptp_data->transmitter_clock_id,
            &ptp_hdr->source_port_id.clock_id,
            sizeof(struct clock_id)) != 0)
        return;

    ptp_data->seqID_FOLLOWUP = rte_be_to_cpu_16(ptp_hdr->seq_id);
    ptp_msg = rte_pktmbuf_mtod_offset(m, struct ptp_message *,
                      sizeof(struct rte_ether_hdr));

    origin_tstamp = &ptp_msg->follow_up.precise_origin_tstamp;
    ptp_data->tstamp1.tv_nsec = ntohl(origin_tstamp->ns);
    ptp_data->tstamp1.tv_sec =
        ((uint64_t)ntohl(origin_tstamp->sec_lsb)) |
        (((uint64_t)ntohs(origin_tstamp->sec_msb)) << 32);

    if (ptp_data->seqID_FOLLOWUP == ptp_data->seqID_SYNC) {
        ret = rte_eth_macaddr_get(ptp_data->portid, &eth_addr);
        if (ret != 0) {
            printf("\nCore %u: port %u failed to get MAC address: %s\n",
                rte_lcore_id(), ptp_data->portid,
                rte_strerror(-ret));
            return;
        }

        created_pkt = rte_pktmbuf_alloc(mbuf_pool);
        pkt_size = sizeof(struct rte_ether_hdr) +
            sizeof(struct delay_req_msg);

        if (rte_pktmbuf_append(created_pkt, pkt_size) == NULL) {
            rte_pktmbuf_free(created_pkt);
            return;
        }
        created_pkt->data_len = pkt_size;
        created_pkt->pkt_len = pkt_size;
        eth_hdr = rte_pktmbuf_mtod(created_pkt, struct rte_ether_hdr *);
        rte_ether_addr_copy(&eth_addr, &eth_hdr->src_addr);

        /* Set multicast address 01-1B-19-00-00-00. */
        rte_ether_addr_copy(&eth_multicast, &eth_hdr->dst_addr);

        eth_hdr->ether_type = htons(PTP_PROTOCOL);
        req_msg = rte_pktmbuf_mtod_offset(created_pkt,
            struct delay_req_msg *, sizeof(struct
            rte_ether_hdr));

        req_msg->hdr.seq_id = htons(ptp_data->seqID_SYNC);
        req_msg->hdr.msg_type = DELAY_REQ;
        req_msg->hdr.ver = 2;
        req_msg->hdr.control = 1;
        req_msg->hdr.log_message_interval = 127;
        req_msg->hdr.message_length =
            htons(sizeof(struct delay_req_msg));
        req_msg->hdr.domain_number = ptp_hdr->domain_number;

        /* Set up clock id. */
        client_clkid =
            &req_msg->hdr.source_port_id.clock_id;

        client_clkid->id[0] = eth_hdr->src_addr.addr_bytes[0];
        client_clkid->id[1] = eth_hdr->src_addr.addr_bytes[1];
        client_clkid->id[2] = eth_hdr->src_addr.addr_bytes[2];
        client_clkid->id[3] = 0xFF;
        client_clkid->id[4] = 0xFE;
        client_clkid->id[5] = eth_hdr->src_addr.addr_bytes[3];
        client_clkid->id[6] = eth_hdr->src_addr.addr_bytes[4];
        client_clkid->id[7] = eth_hdr->src_addr.addr_bytes[5];

        rte_memcpy(&ptp_data->client_clock_id,
               client_clkid,
               sizeof(struct clock_id));

        /* Enable flag for hardware timestamping. */
        created_pkt->ol_flags |= RTE_MBUF_F_TX_IEEE1588_TMST;

        /*Read value from NIC to prevent latching with old value. */
        rte_eth_timesync_read_tx_timestamp(ptp_data->portid,
                &ptp_data->tstamp3);

        /* Transmit the packet. */
        rte_eth_tx_burst(ptp_data->portid, 0, &created_pkt, 1);

        wait_us = 0;
        ptp_data->tstamp3.tv_nsec = 0;
        ptp_data->tstamp3.tv_sec = 0;

        /* Wait at least 1 us to read TX timestamp. */
        while ((rte_eth_timesync_read_tx_timestamp(ptp_data->portid,
                &ptp_data->tstamp3) < 0) && (wait_us < 1000)) {
            rte_delay_us(1);
            wait_us++;
        }
    }
}

/*
 * Update the kernel time with the difference between it and the current NIC
 * time.
 */
static inline void
update_kernel_time(void)
{
    int64_t nsec;
    struct timespec net_time, sys_time;

    clock_gettime(CLOCK_REALTIME, &sys_time);
    rte_eth_timesync_read_time(ptp_data.current_ptp_port, &net_time);

    nsec = (int64_t)timespec64_to_ns(&net_time) -
           (int64_t)timespec64_to_ns(&sys_time);

    ptp_data.new_adj = ns_to_timeval(nsec);

    /*
     * If difference between kernel time and system time in NIC is too big
     * (more than +/- 20 microseconds), use clock_settime to set directly
     * the kernel time, as adjtime is better for small adjustments (takes
     * longer to adjust the time).
     */

    if (nsec > KERNEL_TIME_ADJUST_LIMIT || nsec < -KERNEL_TIME_ADJUST_LIMIT)
        clock_settime(CLOCK_REALTIME, &net_time);
    else
        adjtime(&ptp_data.new_adj, 0);


}

static void
clock_path_delay(struct ptpv2_time_receiver_ordinary *ptp_data)
{
    uint64_t t1_ns, t2_ns, t3_ns, t4_ns;
    int64_t pd, diff;

    t1_ns = timespec64_to_ns(&ptp_data->tstamp1);
    t2_ns = timespec64_to_ns(&ptp_data->tstamp2);
    t3_ns = timespec64_to_ns(&ptp_data->tstamp3);
    t4_ns = timespec64_to_ns(&ptp_data->tstamp4);

    pd = (t2_ns - t3_ns) + (t4_ns - t1_ns);
    diff = t3_ns - t2_ns;
    if (diff <= INT32_MAX && diff >= INT32_MIN)
        ptp_data->path_delay = pd / 2;
    else
        ptp_data->path_delay = 0;
}

static double
pi_sample(struct pi_servo *s, int64_t offset, double local_ts,
      enum servo_state *state)
{
    double ki_term, ppb = s->last_freq;
    double freq_est_interval, localdiff;

    switch (s->count) {
    case 0:
        s->offset[0] = offset;
        s->local[0] = local_ts;
        *state = SERVO_UNLOCKED;
        s->count = 1;
        break;
    case 1:
        s->offset[1] = offset;
        s->local[1] = local_ts;

        /* Make sure the first sample is older than the second. */
        if (s->local[0] >= s->local[1]) {
            *state = SERVO_UNLOCKED;
            s->count = 0;
            break;
        }

        /* Wait long enough before estimating the frequency offset. */
        localdiff = (s->local[1] - s->local[0]) / 1e9;
        localdiff += localdiff * FREQ_EST_MARGIN;
        freq_est_interval = 0.016 / KI;
        if (freq_est_interval > 1000.0)
            freq_est_interval = 1000.0;

        if (localdiff < freq_est_interval) {
            *state = SERVO_UNLOCKED;
            break;
        }

        /* Adjust drift by the measured frequency offset. */
        s->drift += (1e9 - s->drift) * (s->offset[1] - s->offset[0]) /
                        (s->local[1] - s->local[0]);

        if (s->drift < -s->max_frequency)
            s->drift = -s->max_frequency;
        else if (s->drift > s->max_frequency)
            s->drift = s->max_frequency;

        if ((s->first_update &&
             s->first_step_threshold &&
             s->first_step_threshold < llabs(offset)) ||
            (s->step_threshold &&
             s->step_threshold < llabs(offset)))
            *state = SERVO_JUMP;
        else
            *state = SERVO_LOCKED;

        ppb = s->drift;
        s->count = 2;
        break;
    case 2:
        /*
         * reset the clock servo when offset is greater than the max
         * offset value. Note that the clock jump will be performed in
         * step 1, so it is not necessary to have clock jump
         * immediately. This allows re-calculating drift as in initial
         * clock startup.
         */
        if (s->step_threshold &&
            s->step_threshold < llabs(offset)) {
            *state = SERVO_UNLOCKED;
            s->count = 0;
            break;
        }

        ki_term = KI * offset;
        ppb = KP * offset + s->drift + ki_term;
        if (ppb < -s->max_frequency)
            ppb = -s->max_frequency;
        else if (ppb > s->max_frequency)
            ppb = s->max_frequency;
        else
            s->drift += ki_term;

        *state = SERVO_LOCKED;
        break;
    }

    s->last_freq = ppb;
    return ppb;
}

static void
ptp_adjust_servo(struct ptpv2_time_receiver_ordinary *ptp_data)
{
    uint64_t t1_ns, t2_ns;
    double adj_freq;
    enum servo_state state = SERVO_UNLOCKED;

    t1_ns = timespec64_to_ns(&ptp_data->tstamp1);
    t2_ns = timespec64_to_ns(&ptp_data->tstamp2);
    ptp_data->master_offset = t2_ns - t1_ns - ptp_data->path_delay;
    if (!ptp_data->path_delay)
        return;

    adj_freq = pi_sample(ptp_data->servo, ptp_data->master_offset, t2_ns,
             &state);

    switch (state) {
    case SERVO_UNLOCKED:
        break;
    case SERVO_JUMP:
        ptp_data->servo->first_update = 0;
        rte_eth_timesync_adjust_freq(ptp_data->portid,
                        -(long)(adj_freq * 65.536));
        rte_eth_timesync_adjust_time(ptp_data->portid,
                         -ptp_data->master_offset);
        break;
    case SERVO_LOCKED:
        ptp_data->servo->first_update = 0;
        rte_eth_timesync_adjust_freq(ptp_data->portid,
                         -(long)(adj_freq * 65.536));
        break;
    }
}

/*
 * Parse the DELAY_RESP message.
 */
static void
parse_drsp(struct ptpv2_time_receiver_ordinary *ptp_data)
{
    struct rte_mbuf *m = ptp_data->m;
    struct ptp_message *ptp_msg;
    struct tstamp *rx_tstamp;
    uint16_t seq_id;

    ptp_msg = rte_pktmbuf_mtod_offset(m, struct ptp_message *,
                      sizeof(struct rte_ether_hdr));
    seq_id = rte_be_to_cpu_16(ptp_msg->delay_resp.hdr.seq_id);
    if (memcmp(&ptp_data->client_clock_id,
           &ptp_msg->delay_resp.req_port_id.clock_id,
           sizeof(struct clock_id)) == 0) {
        if (seq_id == ptp_data->seqID_FOLLOWUP) {
            rx_tstamp = &ptp_msg->delay_resp.rx_tstamp;
            ptp_data->tstamp4.tv_nsec = ntohl(rx_tstamp->ns);
            ptp_data->tstamp4.tv_sec =
                ((uint64_t)ntohl(rx_tstamp->sec_lsb)) |
                (((uint64_t)ntohs(rx_tstamp->sec_msb)) << 32);

            if (mode == MODE_PI) {
                clock_path_delay(ptp_data);
                ptp_adjust_servo(ptp_data);
            } else {
                /* Evaluate the delta for adjustment. */
                ptp_data->delta = delta_eval(ptp_data);

                rte_eth_timesync_adjust_time(ptp_data->portid,
                                ptp_data->delta);
            }

            ptp_data->current_ptp_port = ptp_data->portid;

            /* Update kernel time if enabled in app parameters. */
            if (ptp_data->kernel_time_set == 1)
                update_kernel_time();



        }
    }
}

/* This function processes PTP packets, implementing time receiver PTP IEEE1588 L2
 * functionality.
 */

/* Parse ptp frames. 8< */
static void
parse_ptp_frames(uint16_t portid, struct rte_mbuf *m) {
    struct ptp_header *ptp_hdr;
    struct rte_ether_hdr *eth_hdr;
    uint16_t eth_type;

    eth_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
    eth_type = rte_be_to_cpu_16(eth_hdr->ether_type);

    if (eth_type == PTP_PROTOCOL) {
        ptp_data.m = m;
        ptp_data.portid = portid;
        ptp_hdr = rte_pktmbuf_mtod_offset(m, struct ptp_header *,
                          sizeof(struct rte_ether_hdr));

        switch (ptp_hdr->msg_type) {
        case SYNC:
            parse_sync(&ptp_data, m->timesync);
            break;
        case FOLLOW_UP:
            parse_fup(&ptp_data);
            break;
        case DELAY_RESP:
            parse_drsp(&ptp_data);
            print_clock_info(&ptp_data);
            break;
        default:
            break;
        }
    }
}
/* >8 End of function processes PTP packets. */

/*
 * The lcore main. This is the main thread that does the work, reading from an
 * input port and writing to an output port.
 */
static void
lcore_main(void)
{
    uint16_t portid;
    unsigned nb_rx;
    struct rte_mbuf *m;

    printf("\nCore %u Waiting for SYNC packets. [Ctrl+C to quit]\n",
            rte_lcore_id());

    /* Run until the application is quit or killed. */

    while (!force_quit) {
        /* Read packet from RX queues. 8< */
        for (portid = 0; portid < ptp_enabled_port_nb; portid++) {

            portid = ptp_enabled_ports[portid];
            nb_rx = rte_eth_rx_burst(portid, 0, &m, 1);

            if (likely(nb_rx == 0))
                continue;

            /* Packet is parsed to determine which type. 8< */
            if (m->ol_flags & RTE_MBUF_F_RX_IEEE1588_PTP)
                parse_ptp_frames(portid, m);
            /* >8 End of packet is parsed to determine which type. */

            rte_pktmbuf_free(m);
        }
        /* >8 End of read packets from RX queues. */
    }
}

static void
print_usage(const char *prgname)
{
    printf("%s [EAL options] -- -p PORTMASK -T VALUE\n"
        " -T VALUE: 0 - Disable, 1 - Enable Linux Clock"
        " Synchronization (0 default)\n"
        " -p PORTMASK: hexadecimal bitmask of ports to configure\n"
        " -c CONTROLLER: 0 - Not used, 1 - PI. The servo which is"
        " used to synchronize the local clock. (0 default)\n",
        prgname);
}

static int
ptp_parse_portmask(const char *portmask)
{
    char *end = NULL;
    unsigned long pm;

    /* Parse the hexadecimal string. */
    pm = strtoul(portmask, &end, 16);

    if ((portmask[0] == '\0') || (end == NULL) || (*end != '\0'))
        return 0;

    return pm;
}

static int
parse_ptp_kernel(const char *param)
{
    char *end = NULL;
    unsigned long pm;

    /* Parse the hexadecimal string. */
    pm = strtoul(param, &end, 16);

    if ((param[0] == '\0') || (end == NULL) || (*end != '\0'))
        return -1;
    if (pm == 0)
        return 0;

    return 1;
}

static int
parse_ptp_servo_mode(const char *param)
{
    char *end = NULL;
    unsigned long pm;

    /* Parse the hexadecimal string. */
    pm = strtoul(param, &end, 10);

    if ((param[0] == '\0') || (end == NULL) || (*end != '\0'))
        return -1;

    return pm;
}

static void
servo_init(struct pi_servo *servo)
{
    memset(servo, 0x00, sizeof(*servo));

    servo->drift = 100000000;
    servo->last_freq = 100000000;
    servo->count = 0;

    servo->max_frequency = 100000000;
    servo->step_threshold = 0.1 * NSEC_PER_SEC;
    servo->first_step_threshold = 0.00002 * NSEC_PER_SEC;
    servo->first_update = 1;
}

/* Parse the commandline arguments. */
static int
ptp_parse_args(int argc, char **argv)
{
    int opt, ret;
    char **argvopt;
    int option_index;
    char *prgname = argv[0];
    static struct option lgopts[] = { {NULL, 0, 0, 0} };

    argvopt = argv;

    while ((opt = getopt_long(argc, argvopt, "p:T:c:",
                  lgopts, &option_index)) != EOF) {

        switch (opt) {

        /* Portmask. */
        case 'p':
            ptp_enabled_port_mask = ptp_parse_portmask(optarg);
            if (ptp_enabled_port_mask == 0) {
                printf("invalid portmask\n");
                print_usage(prgname);
                return -1;
            }
            break;
        /* Time synchronization. */
        case 'T':
            ret = parse_ptp_kernel(optarg);
            if (ret < 0) {
                print_usage(prgname);
                return -1;
            }

            ptp_data.kernel_time_set = ret;
            break;
        case 'c':
            ret = parse_ptp_servo_mode(optarg);
            if (ret == 0) {
                mode = MODE_NONE;
            } else if (ret == 1) {
                mode = MODE_PI;
            } else {
                print_usage(prgname);
                return -1;
            }
            break;

        default:
            print_usage(prgname);
            return -1;
        }
    }

    argv[optind-1] = prgname;

    optind = 1; /* Reset getopt lib. */

    return 0;
}

static void
signal_handler(int signum)
{
    if (signum == SIGINT || signum == SIGTERM)
        force_quit = true;
}

/*
 * The main function, which does initialization and calls the per-lcore
 * functions.
 */
int
main(int argc, char *argv[])
{
    unsigned nb_ports;

    uint16_t portid;

    /* Initialize the Environment Abstraction Layer (EAL). 8< */
    int ret = rte_eal_init(argc, argv);

    if (ret < 0)
        rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
    /* >8 End of initialization of EAL. */

    memset(&ptp_data, 0, sizeof(struct ptpv2_time_receiver_ordinary));

    /* Parse specific arguments. 8< */
    argc -= ret;
    argv += ret;

    force_quit = false;
    signal(SIGINT, signal_handler);
    signal(SIGTERM, signal_handler);

    ret = ptp_parse_args(argc, argv);
    if (ret < 0)
        rte_exit(EXIT_FAILURE, "Error with PTP initialization\n");
    /* >8 End of parsing specific arguments. */

    if (mode == MODE_PI) {
        ptp_data.servo = malloc(sizeof(*(ptp_data.servo)));
        if (!ptp_data.servo)
            rte_exit(EXIT_FAILURE, "no memory for servo\n");

        servo_init(ptp_data.servo);
    }

    /* Check that there is an even number of ports to send/receive on. */
    nb_ports = rte_eth_dev_count_avail();

    /* Creates a new mempool in memory to hold the mbufs. 8< */
    mbuf_pool = rte_pktmbuf_pool_create("MBUF_POOL", NUM_MBUFS * nb_ports,
        MBUF_CACHE_SIZE, 0, RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());
    /* >8 End of a new mempool in memory to hold the mbufs. */

    if (mbuf_pool == NULL)
        rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");

    /* Initialize all ports. 8< */
    RTE_ETH_FOREACH_DEV(portid) {
        if ((ptp_enabled_port_mask & (1 << portid)) != 0) {
            if (port_init(portid, mbuf_pool) == 0) {
                ptp_enabled_ports[ptp_enabled_port_nb] = portid;
                ptp_enabled_port_nb++;
            } else {
                rte_exit(EXIT_FAILURE,
                     "Cannot init port %"PRIu8 "\n",
                     portid);
            }
        } else
            printf("Skipping disabled port %u\n", portid);
    }
    /* >8 End of initialization of all ports. */

    if (ptp_enabled_port_nb == 0) {
        rte_exit(EXIT_FAILURE,
            "All available ports are disabled."
            " Please set portmask.\n");
    }

    if (rte_lcore_count() > 1)
        printf("\nWARNING: Too many lcores enabled. Only 1 used.\n");

    /* Call lcore_main on the main core only. */
    lcore_main();

    RTE_ETH_FOREACH_DEV(portid) {
        if ((ptp_enabled_port_mask & (1 << portid)) == 0)
            continue;

        /* Disable timesync timestamping for the Ethernet device */
        rte_eth_timesync_disable(portid);

        ret = rte_eth_dev_stop(portid);
        if (ret != 0)
            printf("rte_eth_dev_stop: err=%d, port=%d\n", ret, portid);

        rte_eth_dev_close(portid);
    }

    if (mode == MODE_PI)
        free(ptp_data.servo);

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

    return 0;
}