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diff --git a/thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/sntp/sntp.c b/thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/sntp/sntp.c
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index 0000000..71b2abe
--- /dev/null
+++ b/thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/sntp/sntp.c
@@ -0,0 +1,727 @@
+/**
+ * @file
+ * SNTP client module
+ */
+
+/*
+ * Copyright (c) 2007-2009 Frédéric Bernon, Simon Goldschmidt
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Frédéric Bernon, Simon Goldschmidt
+ */
+
+
+/**
+ * @defgroup sntp SNTP
+ * @ingroup apps
+ *
+ * This is simple "SNTP" client for the lwIP raw API.
+ * It is a minimal implementation of SNTPv4 as specified in RFC 4330.
+ *
+ * For a list of some public NTP servers, see this link :
+ * http://support.ntp.org/bin/view/Servers/NTPPoolServers
+ *
+ * @todo:
+ * - set/change servers at runtime
+ * - complete SNTP_CHECK_RESPONSE checks 3 and 4
+ */
+
+#include "lwip/apps/sntp.h"
+
+#include "lwip/opt.h"
+#include "lwip/timeouts.h"
+#include "lwip/udp.h"
+#include "lwip/dns.h"
+#include "lwip/ip_addr.h"
+#include "lwip/pbuf.h"
+#include "lwip/dhcp.h"
+
+#include <string.h>
+#include <time.h>
+
+#if LWIP_UDP
+
+/* Handle support for more than one server via SNTP_MAX_SERVERS */
+#if SNTP_MAX_SERVERS > 1
+#define SNTP_SUPPORT_MULTIPLE_SERVERS 1
+#else /* NTP_MAX_SERVERS > 1 */
+#define SNTP_SUPPORT_MULTIPLE_SERVERS 0
+#endif /* NTP_MAX_SERVERS > 1 */
+
+#if (SNTP_UPDATE_DELAY < 15000) && !defined(SNTP_SUPPRESS_DELAY_CHECK)
+#error "SNTPv4 RFC 4330 enforces a minimum update time of 15 seconds (define SNTP_SUPPRESS_DELAY_CHECK to disable this error)!"
+#endif
+
+/* Configure behaviour depending on microsecond or second precision */
+#ifdef SNTP_SET_SYSTEM_TIME_US
+#define SNTP_CALC_TIME_US 1
+#define SNTP_RECEIVE_TIME_SIZE 2
+#else
+#define SNTP_SET_SYSTEM_TIME_US(sec, us)
+#define SNTP_CALC_TIME_US 0
+#define SNTP_RECEIVE_TIME_SIZE 1
+#endif
+
+
+/* the various debug levels for this file */
+#define SNTP_DEBUG_TRACE (SNTP_DEBUG | LWIP_DBG_TRACE)
+#define SNTP_DEBUG_STATE (SNTP_DEBUG | LWIP_DBG_STATE)
+#define SNTP_DEBUG_WARN (SNTP_DEBUG | LWIP_DBG_LEVEL_WARNING)
+#define SNTP_DEBUG_WARN_STATE (SNTP_DEBUG | LWIP_DBG_LEVEL_WARNING | LWIP_DBG_STATE)
+#define SNTP_DEBUG_SERIOUS (SNTP_DEBUG | LWIP_DBG_LEVEL_SERIOUS)
+
+#define SNTP_ERR_KOD 1
+
+/* SNTP protocol defines */
+#define SNTP_MSG_LEN 48
+
+#define SNTP_OFFSET_LI_VN_MODE 0
+#define SNTP_LI_MASK 0xC0
+#define SNTP_LI_NO_WARNING 0x00
+#define SNTP_LI_LAST_MINUTE_61_SEC 0x01
+#define SNTP_LI_LAST_MINUTE_59_SEC 0x02
+#define SNTP_LI_ALARM_CONDITION 0x03 /* (clock not synchronized) */
+
+#define SNTP_VERSION_MASK 0x38
+#define SNTP_VERSION (4/* NTP Version 4*/<<3)
+
+#define SNTP_MODE_MASK 0x07
+#define SNTP_MODE_CLIENT 0x03
+#define SNTP_MODE_SERVER 0x04
+#define SNTP_MODE_BROADCAST 0x05
+
+#define SNTP_OFFSET_STRATUM 1
+#define SNTP_STRATUM_KOD 0x00
+
+#define SNTP_OFFSET_ORIGINATE_TIME 24
+#define SNTP_OFFSET_RECEIVE_TIME 32
+#define SNTP_OFFSET_TRANSMIT_TIME 40
+
+/* number of seconds between 1900 and 1970 (MSB=1)*/
+#define DIFF_SEC_1900_1970 (2208988800UL)
+/* number of seconds between 1970 and Feb 7, 2036 (6:28:16 UTC) (MSB=0) */
+#define DIFF_SEC_1970_2036 (2085978496UL)
+
+/**
+ * SNTP packet format (without optional fields)
+ * Timestamps are coded as 64 bits:
+ * - 32 bits seconds since Jan 01, 1970, 00:00
+ * - 32 bits seconds fraction (0-padded)
+ * For future use, if the MSB in the seconds part is set, seconds are based
+ * on Feb 07, 2036, 06:28:16.
+ */
+#ifdef PACK_STRUCT_USE_INCLUDES
+# include "arch/bpstruct.h"
+#endif
+PACK_STRUCT_BEGIN
+struct sntp_msg {
+ PACK_STRUCT_FLD_8(u8_t li_vn_mode);
+ PACK_STRUCT_FLD_8(u8_t stratum);
+ PACK_STRUCT_FLD_8(u8_t poll);
+ PACK_STRUCT_FLD_8(u8_t precision);
+ PACK_STRUCT_FIELD(u32_t root_delay);
+ PACK_STRUCT_FIELD(u32_t root_dispersion);
+ PACK_STRUCT_FIELD(u32_t reference_identifier);
+ PACK_STRUCT_FIELD(u32_t reference_timestamp[2]);
+ PACK_STRUCT_FIELD(u32_t originate_timestamp[2]);
+ PACK_STRUCT_FIELD(u32_t receive_timestamp[2]);
+ PACK_STRUCT_FIELD(u32_t transmit_timestamp[2]);
+} PACK_STRUCT_STRUCT;
+PACK_STRUCT_END
+#ifdef PACK_STRUCT_USE_INCLUDES
+# include "arch/epstruct.h"
+#endif
+
+/* function prototypes */
+static void sntp_request(void *arg);
+
+/** The operating mode */
+static u8_t sntp_opmode;
+
+/** The UDP pcb used by the SNTP client */
+static struct udp_pcb* sntp_pcb;
+/** Names/Addresses of servers */
+struct sntp_server {
+#if SNTP_SERVER_DNS
+ char* name;
+#endif /* SNTP_SERVER_DNS */
+ ip_addr_t addr;
+};
+static struct sntp_server sntp_servers[SNTP_MAX_SERVERS];
+
+#if SNTP_GET_SERVERS_FROM_DHCP
+static u8_t sntp_set_servers_from_dhcp;
+#endif /* SNTP_GET_SERVERS_FROM_DHCP */
+#if SNTP_SUPPORT_MULTIPLE_SERVERS
+/** The currently used server (initialized to 0) */
+static u8_t sntp_current_server;
+#else /* SNTP_SUPPORT_MULTIPLE_SERVERS */
+#define sntp_current_server 0
+#endif /* SNTP_SUPPORT_MULTIPLE_SERVERS */
+
+#if SNTP_RETRY_TIMEOUT_EXP
+#define SNTP_RESET_RETRY_TIMEOUT() sntp_retry_timeout = SNTP_RETRY_TIMEOUT
+/** Retry time, initialized with SNTP_RETRY_TIMEOUT and doubled with each retry. */
+static u32_t sntp_retry_timeout;
+#else /* SNTP_RETRY_TIMEOUT_EXP */
+#define SNTP_RESET_RETRY_TIMEOUT()
+#define sntp_retry_timeout SNTP_RETRY_TIMEOUT
+#endif /* SNTP_RETRY_TIMEOUT_EXP */
+
+#if SNTP_CHECK_RESPONSE >= 1
+/** Saves the last server address to compare with response */
+static ip_addr_t sntp_last_server_address;
+#endif /* SNTP_CHECK_RESPONSE >= 1 */
+
+#if SNTP_CHECK_RESPONSE >= 2
+/** Saves the last timestamp sent (which is sent back by the server)
+ * to compare against in response */
+static u32_t sntp_last_timestamp_sent[2];
+#endif /* SNTP_CHECK_RESPONSE >= 2 */
+
+/**
+ * SNTP processing of received timestamp
+ */
+static void
+sntp_process(u32_t *receive_timestamp)
+{
+ /* convert SNTP time (1900-based) to unix GMT time (1970-based)
+ * if MSB is 0, SNTP time is 2036-based!
+ */
+ u32_t rx_secs = lwip_ntohl(receive_timestamp[0]);
+ int is_1900_based = ((rx_secs & 0x80000000) != 0);
+ u32_t t = is_1900_based ? (rx_secs - DIFF_SEC_1900_1970) : (rx_secs + DIFF_SEC_1970_2036);
+ time_t tim = t;
+
+#if SNTP_CALC_TIME_US
+ u32_t us = lwip_ntohl(receive_timestamp[1]) / 4295;
+ SNTP_SET_SYSTEM_TIME_US(t, us);
+ /* display local time from GMT time */
+ LWIP_DEBUGF(SNTP_DEBUG_TRACE, ("sntp_process: %s, %"U32_F" us", ctime(&tim), us));
+
+#else /* SNTP_CALC_TIME_US */
+
+ /* change system time and/or the update the RTC clock */
+ SNTP_SET_SYSTEM_TIME(t);
+ /* display local time from GMT time */
+ LWIP_DEBUGF(SNTP_DEBUG_TRACE, ("sntp_process: %s", ctime(&tim)));
+#endif /* SNTP_CALC_TIME_US */
+ LWIP_UNUSED_ARG(tim);
+}
+
+/**
+ * Initialize request struct to be sent to server.
+ */
+static void
+sntp_initialize_request(struct sntp_msg *req)
+{
+ memset(req, 0, SNTP_MSG_LEN);
+ req->li_vn_mode = SNTP_LI_NO_WARNING | SNTP_VERSION | SNTP_MODE_CLIENT;
+
+#if SNTP_CHECK_RESPONSE >= 2
+ {
+ u32_t sntp_time_sec, sntp_time_us;
+ /* fill in transmit timestamp and save it in 'sntp_last_timestamp_sent' */
+ SNTP_GET_SYSTEM_TIME(sntp_time_sec, sntp_time_us);
+ sntp_last_timestamp_sent[0] = lwip_htonl(sntp_time_sec + DIFF_SEC_1900_1970);
+ req->transmit_timestamp[0] = sntp_last_timestamp_sent[0];
+ /* we send/save us instead of fraction to be faster... */
+ sntp_last_timestamp_sent[1] = lwip_htonl(sntp_time_us);
+ req->transmit_timestamp[1] = sntp_last_timestamp_sent[1];
+ }
+#endif /* SNTP_CHECK_RESPONSE >= 2 */
+}
+
+/**
+ * Retry: send a new request (and increase retry timeout).
+ *
+ * @param arg is unused (only necessary to conform to sys_timeout)
+ */
+static void
+sntp_retry(void* arg)
+{
+ LWIP_UNUSED_ARG(arg);
+
+ LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_retry: Next request will be sent in %"U32_F" ms\n",
+ sntp_retry_timeout));
+
+ /* set up a timer to send a retry and increase the retry delay */
+ sys_timeout(sntp_retry_timeout, sntp_request, NULL);
+
+#if SNTP_RETRY_TIMEOUT_EXP
+ {
+ u32_t new_retry_timeout;
+ /* increase the timeout for next retry */
+ new_retry_timeout = sntp_retry_timeout << 1;
+ /* limit to maximum timeout and prevent overflow */
+ if ((new_retry_timeout <= SNTP_RETRY_TIMEOUT_MAX) &&
+ (new_retry_timeout > sntp_retry_timeout)) {
+ sntp_retry_timeout = new_retry_timeout;
+ }
+ }
+#endif /* SNTP_RETRY_TIMEOUT_EXP */
+}
+
+#if SNTP_SUPPORT_MULTIPLE_SERVERS
+/**
+ * If Kiss-of-Death is received (or another packet parsing error),
+ * try the next server or retry the current server and increase the retry
+ * timeout if only one server is available.
+ * (implicitly, SNTP_MAX_SERVERS > 1)
+ *
+ * @param arg is unused (only necessary to conform to sys_timeout)
+ */
+static void
+sntp_try_next_server(void* arg)
+{
+ u8_t old_server, i;
+ LWIP_UNUSED_ARG(arg);
+
+ old_server = sntp_current_server;
+ for (i = 0; i < SNTP_MAX_SERVERS - 1; i++) {
+ sntp_current_server++;
+ if (sntp_current_server >= SNTP_MAX_SERVERS) {
+ sntp_current_server = 0;
+ }
+ if (!ip_addr_isany(&sntp_servers[sntp_current_server].addr)
+#if SNTP_SERVER_DNS
+ || (sntp_servers[sntp_current_server].name != NULL)
+#endif
+ ) {
+ LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_try_next_server: Sending request to server %"U16_F"\n",
+ (u16_t)sntp_current_server));
+ /* new server: reset retry timeout */
+ SNTP_RESET_RETRY_TIMEOUT();
+ /* instantly send a request to the next server */
+ sntp_request(NULL);
+ return;
+ }
+ }
+ /* no other valid server found */
+ sntp_current_server = old_server;
+ sntp_retry(NULL);
+}
+#else /* SNTP_SUPPORT_MULTIPLE_SERVERS */
+/* Always retry on error if only one server is supported */
+#define sntp_try_next_server sntp_retry
+#endif /* SNTP_SUPPORT_MULTIPLE_SERVERS */
+
+/** UDP recv callback for the sntp pcb */
+static void
+sntp_recv(void *arg, struct udp_pcb* pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
+{
+ u8_t mode;
+ u8_t stratum;
+ u32_t receive_timestamp[SNTP_RECEIVE_TIME_SIZE];
+ err_t err;
+
+ LWIP_UNUSED_ARG(arg);
+ LWIP_UNUSED_ARG(pcb);
+
+ /* packet received: stop retry timeout */
+ sys_untimeout(sntp_try_next_server, NULL);
+ sys_untimeout(sntp_request, NULL);
+
+ err = ERR_ARG;
+#if SNTP_CHECK_RESPONSE >= 1
+ /* check server address and port */
+ if (((sntp_opmode != SNTP_OPMODE_POLL) || ip_addr_cmp(addr, &sntp_last_server_address)) &&
+ (port == SNTP_PORT))
+#else /* SNTP_CHECK_RESPONSE >= 1 */
+ LWIP_UNUSED_ARG(addr);
+ LWIP_UNUSED_ARG(port);
+#endif /* SNTP_CHECK_RESPONSE >= 1 */
+ {
+ /* process the response */
+ if (p->tot_len == SNTP_MSG_LEN) {
+ pbuf_copy_partial(p, &mode, 1, SNTP_OFFSET_LI_VN_MODE);
+ mode &= SNTP_MODE_MASK;
+ /* if this is a SNTP response... */
+ if (((sntp_opmode == SNTP_OPMODE_POLL) && (mode == SNTP_MODE_SERVER)) ||
+ ((sntp_opmode == SNTP_OPMODE_LISTENONLY) && (mode == SNTP_MODE_BROADCAST))) {
+ pbuf_copy_partial(p, &stratum, 1, SNTP_OFFSET_STRATUM);
+ if (stratum == SNTP_STRATUM_KOD) {
+ /* Kiss-of-death packet. Use another server or increase UPDATE_DELAY. */
+ err = SNTP_ERR_KOD;
+ LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_recv: Received Kiss-of-Death\n"));
+ } else {
+#if SNTP_CHECK_RESPONSE >= 2
+ /* check originate_timetamp against sntp_last_timestamp_sent */
+ u32_t originate_timestamp[2];
+ pbuf_copy_partial(p, &originate_timestamp, 8, SNTP_OFFSET_ORIGINATE_TIME);
+ if ((originate_timestamp[0] != sntp_last_timestamp_sent[0]) ||
+ (originate_timestamp[1] != sntp_last_timestamp_sent[1]))
+ {
+ LWIP_DEBUGF(SNTP_DEBUG_WARN, ("sntp_recv: Invalid originate timestamp in response\n"));
+ } else
+#endif /* SNTP_CHECK_RESPONSE >= 2 */
+ /* @todo: add code for SNTP_CHECK_RESPONSE >= 3 and >= 4 here */
+ {
+ /* correct answer */
+ err = ERR_OK;
+ pbuf_copy_partial(p, &receive_timestamp, SNTP_RECEIVE_TIME_SIZE * 4, SNTP_OFFSET_TRANSMIT_TIME);
+ }
+ }
+ } else {
+ LWIP_DEBUGF(SNTP_DEBUG_WARN, ("sntp_recv: Invalid mode in response: %"U16_F"\n", (u16_t)mode));
+ /* wait for correct response */
+ err = ERR_TIMEOUT;
+ }
+ } else {
+ LWIP_DEBUGF(SNTP_DEBUG_WARN, ("sntp_recv: Invalid packet length: %"U16_F"\n", p->tot_len));
+ }
+ }
+#if SNTP_CHECK_RESPONSE >= 1
+ else {
+ /* packet from wrong remote address or port, wait for correct response */
+ err = ERR_TIMEOUT;
+ }
+#endif /* SNTP_CHECK_RESPONSE >= 1 */
+ pbuf_free(p);
+ if (err == ERR_OK) {
+ sntp_process(receive_timestamp);
+
+ /* Set up timeout for next request (only if poll response was received)*/
+ if (sntp_opmode == SNTP_OPMODE_POLL) {
+ /* Correct response, reset retry timeout */
+ SNTP_RESET_RETRY_TIMEOUT();
+
+ sys_timeout((u32_t)SNTP_UPDATE_DELAY, sntp_request, NULL);
+ LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_recv: Scheduled next time request: %"U32_F" ms\n",
+ (u32_t)SNTP_UPDATE_DELAY));
+ }
+ } else if (err != ERR_TIMEOUT) {
+ /* Errors are only processed in case of an explicit poll response */
+ if (sntp_opmode == SNTP_OPMODE_POLL) {
+ if (err == SNTP_ERR_KOD) {
+ /* Kiss-of-death packet. Use another server or increase UPDATE_DELAY. */
+ sntp_try_next_server(NULL);
+ } else {
+ /* another error, try the same server again */
+ sntp_retry(NULL);
+ }
+ }
+ }
+}
+
+/** Actually send an sntp request to a server.
+ *
+ * @param server_addr resolved IP address of the SNTP server
+ */
+static void
+sntp_send_request(const ip_addr_t *server_addr)
+{
+ struct pbuf* p;
+ p = pbuf_alloc(PBUF_TRANSPORT, SNTP_MSG_LEN, PBUF_RAM);
+ if (p != NULL) {
+ struct sntp_msg *sntpmsg = (struct sntp_msg *)p->payload;
+ LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_send_request: Sending request to server\n"));
+ /* initialize request message */
+ sntp_initialize_request(sntpmsg);
+ /* send request */
+ udp_sendto(sntp_pcb, p, server_addr, SNTP_PORT);
+ /* free the pbuf after sending it */
+ pbuf_free(p);
+ /* set up receive timeout: try next server or retry on timeout */
+ sys_timeout((u32_t)SNTP_RECV_TIMEOUT, sntp_try_next_server, NULL);
+#if SNTP_CHECK_RESPONSE >= 1
+ /* save server address to verify it in sntp_recv */
+ ip_addr_set(&sntp_last_server_address, server_addr);
+#endif /* SNTP_CHECK_RESPONSE >= 1 */
+ } else {
+ LWIP_DEBUGF(SNTP_DEBUG_SERIOUS, ("sntp_send_request: Out of memory, trying again in %"U32_F" ms\n",
+ (u32_t)SNTP_RETRY_TIMEOUT));
+ /* out of memory: set up a timer to send a retry */
+ sys_timeout((u32_t)SNTP_RETRY_TIMEOUT, sntp_request, NULL);
+ }
+}
+
+#if SNTP_SERVER_DNS
+/**
+ * DNS found callback when using DNS names as server address.
+ */
+static void
+sntp_dns_found(const char* hostname, const ip_addr_t *ipaddr, void *arg)
+{
+ LWIP_UNUSED_ARG(hostname);
+ LWIP_UNUSED_ARG(arg);
+
+ if (ipaddr != NULL) {
+ /* Address resolved, send request */
+ LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_dns_found: Server address resolved, sending request\n"));
+ sntp_send_request(ipaddr);
+ } else {
+ /* DNS resolving failed -> try another server */
+ LWIP_DEBUGF(SNTP_DEBUG_WARN_STATE, ("sntp_dns_found: Failed to resolve server address resolved, trying next server\n"));
+ sntp_try_next_server(NULL);
+ }
+}
+#endif /* SNTP_SERVER_DNS */
+
+/**
+ * Send out an sntp request.
+ *
+ * @param arg is unused (only necessary to conform to sys_timeout)
+ */
+static void
+sntp_request(void *arg)
+{
+ ip_addr_t sntp_server_address;
+ err_t err;
+
+ LWIP_UNUSED_ARG(arg);
+
+ /* initialize SNTP server address */
+#if SNTP_SERVER_DNS
+ if (sntp_servers[sntp_current_server].name) {
+ /* always resolve the name and rely on dns-internal caching & timeout */
+ ip_addr_set_zero(&sntp_servers[sntp_current_server].addr);
+ err = dns_gethostbyname(sntp_servers[sntp_current_server].name, &sntp_server_address,
+ sntp_dns_found, NULL);
+ if (err == ERR_INPROGRESS) {
+ /* DNS request sent, wait for sntp_dns_found being called */
+ LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_request: Waiting for server address to be resolved.\n"));
+ return;
+ } else if (err == ERR_OK) {
+ sntp_servers[sntp_current_server].addr = sntp_server_address;
+ }
+ } else
+#endif /* SNTP_SERVER_DNS */
+ {
+ sntp_server_address = sntp_servers[sntp_current_server].addr;
+ err = (ip_addr_isany_val(sntp_server_address)) ? ERR_ARG : ERR_OK;
+ }
+
+ if (err == ERR_OK) {
+ LWIP_DEBUGF(SNTP_DEBUG_TRACE, ("sntp_request: current server address is %s\n",
+ ipaddr_ntoa(&sntp_server_address)));
+ sntp_send_request(&sntp_server_address);
+ } else {
+ /* address conversion failed, try another server */
+ LWIP_DEBUGF(SNTP_DEBUG_WARN_STATE, ("sntp_request: Invalid server address, trying next server.\n"));
+ sys_timeout((u32_t)SNTP_RETRY_TIMEOUT, sntp_try_next_server, NULL);
+ }
+}
+
+/**
+ * @ingroup sntp
+ * Initialize this module.
+ * Send out request instantly or after SNTP_STARTUP_DELAY(_FUNC).
+ */
+void
+sntp_init(void)
+{
+#ifdef SNTP_SERVER_ADDRESS
+#if SNTP_SERVER_DNS
+ sntp_setservername(0, SNTP_SERVER_ADDRESS);
+#else
+#error SNTP_SERVER_ADDRESS string not supported SNTP_SERVER_DNS==0
+#endif
+#endif /* SNTP_SERVER_ADDRESS */
+
+ if (sntp_pcb == NULL) {
+ sntp_pcb = udp_new_ip_type(IPADDR_TYPE_ANY);
+ LWIP_ASSERT("Failed to allocate udp pcb for sntp client", sntp_pcb != NULL);
+ if (sntp_pcb != NULL) {
+ udp_recv(sntp_pcb, sntp_recv, NULL);
+
+ if (sntp_opmode == SNTP_OPMODE_POLL) {
+ SNTP_RESET_RETRY_TIMEOUT();
+#if SNTP_STARTUP_DELAY
+ sys_timeout((u32_t)SNTP_STARTUP_DELAY_FUNC, sntp_request, NULL);
+#else
+ sntp_request(NULL);
+#endif
+ } else if (sntp_opmode == SNTP_OPMODE_LISTENONLY) {
+ ip_set_option(sntp_pcb, SOF_BROADCAST);
+ udp_bind(sntp_pcb, IP_ANY_TYPE, SNTP_PORT);
+ }
+ }
+ }
+}
+
+/**
+ * @ingroup sntp
+ * Stop this module.
+ */
+void
+sntp_stop(void)
+{
+ if (sntp_pcb != NULL) {
+ sys_untimeout(sntp_request, NULL);
+ sys_untimeout(sntp_try_next_server, NULL);
+ udp_remove(sntp_pcb);
+ sntp_pcb = NULL;
+ }
+}
+
+/**
+ * @ingroup sntp
+ * Get enabled state.
+ */
+u8_t sntp_enabled(void)
+{
+ return (sntp_pcb != NULL)? 1 : 0;
+}
+
+/**
+ * @ingroup sntp
+ * Sets the operating mode.
+ * @param operating_mode one of the available operating modes
+ */
+void
+sntp_setoperatingmode(u8_t operating_mode)
+{
+ LWIP_ASSERT("Invalid operating mode", operating_mode <= SNTP_OPMODE_LISTENONLY);
+ LWIP_ASSERT("Operating mode must not be set while SNTP client is running", sntp_pcb == NULL);
+ sntp_opmode = operating_mode;
+}
+
+/**
+ * @ingroup sntp
+ * Gets the operating mode.
+ */
+u8_t
+sntp_getoperatingmode(void)
+{
+ return sntp_opmode;
+}
+
+#if SNTP_GET_SERVERS_FROM_DHCP
+/**
+ * Config SNTP server handling by IP address, name, or DHCP; clear table
+ * @param set_servers_from_dhcp enable or disable getting server addresses from dhcp
+ */
+void
+sntp_servermode_dhcp(int set_servers_from_dhcp)
+{
+ u8_t new_mode = set_servers_from_dhcp ? 1 : 0;
+ if (sntp_set_servers_from_dhcp != new_mode) {
+ sntp_set_servers_from_dhcp = new_mode;
+ }
+}
+#endif /* SNTP_GET_SERVERS_FROM_DHCP */
+
+/**
+ * @ingroup sntp
+ * Initialize one of the NTP servers by IP address
+ *
+ * @param idx the index of the NTP server to set must be < SNTP_MAX_SERVERS
+ * @param server IP address of the NTP server to set
+ */
+void
+sntp_setserver(u8_t idx, const ip_addr_t *server)
+{
+ if (idx < SNTP_MAX_SERVERS) {
+ if (server != NULL) {
+ sntp_servers[idx].addr = (*server);
+ } else {
+ ip_addr_set_zero(&sntp_servers[idx].addr);
+ }
+#if SNTP_SERVER_DNS
+ sntp_servers[idx].name = NULL;
+#endif
+ }
+}
+
+#if LWIP_DHCP && SNTP_GET_SERVERS_FROM_DHCP
+/**
+ * Initialize one of the NTP servers by IP address, required by DHCP
+ *
+ * @param numdns the index of the NTP server to set must be < SNTP_MAX_SERVERS
+ * @param dnsserver IP address of the NTP server to set
+ */
+void
+dhcp_set_ntp_servers(u8_t num, const ip4_addr_t *server)
+{
+ LWIP_DEBUGF(SNTP_DEBUG_TRACE, ("sntp: %s %u.%u.%u.%u as NTP server #%u via DHCP\n",
+ (sntp_set_servers_from_dhcp ? "Got" : "Rejected"),
+ ip4_addr1(server), ip4_addr2(server), ip4_addr3(server), ip4_addr4(server), num));
+ if (sntp_set_servers_from_dhcp && num) {
+ u8_t i;
+ for (i = 0; (i < num) && (i < SNTP_MAX_SERVERS); i++) {
+ ip_addr_t addr;
+ ip_addr_copy_from_ip4(addr, server[i]);
+ sntp_setserver(i, &addr);
+ }
+ for (i = num; i < SNTP_MAX_SERVERS; i++) {
+ sntp_setserver(i, NULL);
+ }
+ }
+}
+#endif /* LWIP_DHCP && SNTP_GET_SERVERS_FROM_DHCP */
+
+/**
+ * @ingroup sntp
+ * Obtain one of the currently configured by IP address (or DHCP) NTP servers
+ *
+ * @param idx the index of the NTP server
+ * @return IP address of the indexed NTP server or "ip_addr_any" if the NTP
+ * server has not been configured by address (or at all).
+ */
+const ip_addr_t*
+sntp_getserver(u8_t idx)
+{
+ if (idx < SNTP_MAX_SERVERS) {
+ return &sntp_servers[idx].addr;
+ }
+ return IP_ADDR_ANY;
+}
+
+#if SNTP_SERVER_DNS
+/**
+ * Initialize one of the NTP servers by name
+ *
+ * @param numdns the index of the NTP server to set must be < SNTP_MAX_SERVERS
+ * @param dnsserver DNS name of the NTP server to set, to be resolved at contact time
+ */
+void
+sntp_setservername(u8_t idx, char *server)
+{
+ if (idx < SNTP_MAX_SERVERS) {
+ sntp_servers[idx].name = server;
+ }
+}
+
+/**
+ * Obtain one of the currently configured by name NTP servers.
+ *
+ * @param numdns the index of the NTP server
+ * @return IP address of the indexed NTP server or NULL if the NTP
+ * server has not been configured by name (or at all)
+ */
+char *
+sntp_getservername(u8_t idx)
+{
+ if (idx < SNTP_MAX_SERVERS) {
+ return sntp_servers[idx].name;
+ }
+ return NULL;
+}
+#endif /* SNTP_SERVER_DNS */
+
+#endif /* LWIP_UDP */