ntp.c File Reference

#include "ntp.h"
#include <string.h>
#include <time.h>
#include "pico/stdlib.h"
#include "pico/cyw43_arch.h"
#include "lwip/dns.h"
#include "lwip/pbuf.h"
#include "lwip/udp.h"

Go to the source code of this file.

Functions
static void	ntp_result (NTP_T *state, int status, time_t *result)
static void	ntp_request (NTP_T *state)
static int64_t	ntp_failed_handler (alarm_id_t id, void *user_data)
static void	ntp_dns_found (const char *hostname, const ip_addr_t *ipaddr, void *arg)
static void	ntp_recv (void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
static NTP_T *	ntp_init (void)
void	ntp_deinit (void)
	NTP deinit.
void	ntp_update_time (void)
	NTP update time.

Variables
volatile struct tm *	utc = NULL
	UTC time struct.
volatile struct tm *	current_utc = NULL
	UTC time struct.

Function Documentation

ntp_deinit()

void ntp_deinit

(

void

)

NTP deinit.

Function de-initializes the NTP.

Definition at line 114 of file ntp.c.

{
    if (utc)
    {
        free((void*)utc);
        utc = NULL;
    }
}

References utc.

Referenced by main().

ntp_dns_found()

static void ntp_dns_found ( const char *  hostname, const ip_addr_t *  ipaddr, void *  arg  )

static

Definition at line 56 of file ntp.c.

{
    NTP_T *state = (NTP_T*)arg;
    if (ipaddr)
    {
        state->ntp_server_address = *ipaddr;
        printf("NTP address %s\n", ipaddr_ntoa(ipaddr));
        ntp_request(state);
    }
    else
    {
        printf("NTP DNS request failed\n");
        ntp_result(state, -1, NULL);
    }
}

References ntp_request(), ntp_result(), and NTP_T_::ntp_server_address.

Referenced by ntp_update_time().

ntp_failed_handler()

static int64_t ntp_failed_handler ( alarm_id_t  id, void *  user_data  )

static

Definition at line 48 of file ntp.c.

{
    NTP_T* state = (NTP_T*)user_data;
    printf("NTP request failed\n");
    ntp_result(state, -1, NULL);
    return 0;
}

References ntp_result().

Referenced by ntp_update_time().

ntp_init()

static NTP_T * ntp_init ( void  )

static

Definition at line 95 of file ntp.c.

{
    NTP_T *state = (NTP_T*)calloc(1, sizeof(NTP_T));
    if (!state)
    {
        printf("Failed to allocate state\n");
        return NULL;
    }
    state->ntp_pcb = udp_new_ip_type(IPADDR_TYPE_ANY);
    if (!state->ntp_pcb)
    {
        printf("Failed to create PCB\n");
        free(state);
        return NULL;
    }
    udp_recv(state->ntp_pcb, ntp_recv, state);
    return state;
}

References NTP_T_::ntp_pcb, and ntp_recv().

Referenced by ntp_update_time().

ntp_recv()

static void ntp_recv ( void *  arg, struct udp_pcb *  pcb, struct pbuf *  p, const ip_addr_t *  addr, u16_t  port  )

static

Definition at line 72 of file ntp.c.

{
    NTP_T *state = (NTP_T*)arg;
    uint8_t mode = pbuf_get_at(p, 0) & 0x7;
    uint8_t stratum = pbuf_get_at(p, 1);
 
    if (ip_addr_cmp(addr, &state->ntp_server_address) && port == NTP_PORT && p->tot_len == NTP_MSG_LEN &&mode == 0x4 && stratum != 0)
    {
        uint8_t seconds_buf[4] = {0};
        pbuf_copy_partial(p, seconds_buf, sizeof(seconds_buf), 40);
        uint32_t seconds_since_1900 = seconds_buf[0] << 24 | seconds_buf[1] << 16 | seconds_buf[2] << 8 | seconds_buf[3];
        uint32_t seconds_since_1970 = seconds_since_1900 - NTP_DELTA;
        time_t epoch = seconds_since_1970;
        ntp_result(state, 0, &epoch);
    }
    else
    {
        printf("Invalid NTP response\n");
        ntp_result(state, -1, NULL);
    }
    pbuf_free(p);
}

References NTP_DELTA, NTP_MSG_LEN, NTP_PORT, ntp_result(), and NTP_T_::ntp_server_address.

Referenced by ntp_init().

ntp_request()

static void ntp_request ( NTP_T *  state )

static

Definition at line 36 of file ntp.c.

{
    cyw43_arch_lwip_begin();
    struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, NTP_MSG_LEN, PBUF_RAM);
    uint8_t *req = (uint8_t *) p->payload;
    memset(req, 0, NTP_MSG_LEN);
    req[0] = 0x1b;
    udp_sendto(state->ntp_pcb, p, &state->ntp_server_address, NTP_PORT);
    pbuf_free(p);
    cyw43_arch_lwip_end();
}

References NTP_MSG_LEN, NTP_T_::ntp_pcb, NTP_PORT, and NTP_T_::ntp_server_address.

Referenced by ntp_dns_found(), and ntp_update_time().

ntp_result()

static void ntp_result ( NTP_T *  state, int  status, time_t *  result  )

static

Definition at line 16 of file ntp.c.

{
    if (status == 0 && result)
    {
        // *result += TIMEZONE_OFFSET;
        if (!utc)
            utc = gmtime(result);
        current_utc = gmtime(result);
        printf("Got NTP response: %02d/%02d/%04d %02d:%02d:%02d\n", current_utc->tm_mday, current_utc->tm_mon + 1, current_utc->tm_year + 1900, current_utc->tm_hour, current_utc->tm_min, current_utc->tm_sec);
    }
 
    if (state->ntp_resend_alarm > 0)
    {
        cancel_alarm(state->ntp_resend_alarm);
        state->ntp_resend_alarm = 0;
    }
    state->ntp_test_time = make_timeout_time_ms(NTP_TEST_TIME);
    state->dns_request_sent = false;
}

References current_utc, NTP_T_::dns_request_sent, NTP_T_::ntp_resend_alarm, NTP_TEST_TIME, NTP_T_::ntp_test_time, and utc.

Referenced by ntp_dns_found(), ntp_failed_handler(), ntp_recv(), and ntp_update_time().

ntp_update_time()

void ntp_update_time

(

void

)

NTP update time.

Function updates the NTP time.

Definition at line 123 of file ntp.c.

{
    NTP_T *state = ntp_init();
    if (!state)
        return;
    if (absolute_time_diff_us(get_absolute_time(), state->ntp_test_time) < 0 && !state->dns_request_sent)
    {
        state->ntp_resend_alarm = add_alarm_in_ms(NTP_RESEND_TIME, ntp_failed_handler, state, true);
        cyw43_arch_lwip_begin();
        int err = dns_gethostbyname(NTP_SERVER, &state->ntp_server_address, ntp_dns_found, state);
        cyw43_arch_lwip_end();
 
        state->dns_request_sent = true;
        if (err == ERR_OK)
            ntp_request(state);
        else if (err != ERR_INPROGRESS)
        {
            printf("DNS request failed\n");
            ntp_result(state, -1, NULL);
        }
    }
    free(state);
}

References NTP_T_::dns_request_sent, ntp_dns_found(), ntp_failed_handler(), ntp_init(), ntp_request(), NTP_T_::ntp_resend_alarm, NTP_RESEND_TIME, ntp_result(), NTP_SERVER, NTP_T_::ntp_server_address, and NTP_T_::ntp_test_time.

Referenced by init().

Variable Documentation

current_utc

volatile struct tm* current_utc = NULL

UTC time struct.

Struct for the last checked UTC time.

Definition at line 14 of file ntp.c.

Referenced by ntp_result().

utc

volatile struct tm* utc = NULL

UTC time struct.

Struct for the UTC time of program start.

Definition at line 13 of file ntp.c.

Referenced by ntp_deinit(), ntp_result(), and ssi_handler().