From 8dfd5e82cbe03fcbf9d32f742856a6eda15b64fb Mon Sep 17 00:00:00 2001 From: sg Date: Wed, 7 Oct 2015 22:16:48 +0200 Subject: [PATCH] first 'app': added SNTP client from contrib (unmodified from 196cbae376dfd484b4833503dd43057b4c3462fa, 28.08.2015) --- src/apps/sntp/sntp.c | 801 +++++++++++++++++++++++++++++++++++ src/include/lwip/apps/sntp.h | 58 +++ 2 files changed, 859 insertions(+) create mode 100644 src/apps/sntp/sntp.c create mode 100644 src/include/lwip/apps/sntp.h diff --git a/src/apps/sntp/sntp.c b/src/apps/sntp/sntp.c new file mode 100644 index 00000000..987d50d4 --- /dev/null +++ b/src/apps/sntp/sntp.c @@ -0,0 +1,801 @@ +/** + * @file + * SNTP client module + * + * 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 + * - support broadcast/multicast mode? + */ + +/* + * 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: Simon Goldschmidt (lwIP raw API part) + */ + +#include "lwip/apps/sntp.h" + +#include "lwip/opt.h" +#include "lwip/timers.h" +#include "lwip/udp.h" +#include "lwip/dns.h" +#include "lwip/ip_addr.h" +#include "lwip/pbuf.h" +#include "lwip/dhcp.h" + +#include +#include + +#if LWIP_UDP + +/** + * SNTP_DEBUG: Enable debugging for SNTP. + */ +#ifndef SNTP_DEBUG +#define SNTP_DEBUG LWIP_DBG_OFF +#endif + +/** SNTP server port */ +#ifndef SNTP_PORT +#define SNTP_PORT 123 +#endif + +/** Set this to 1 to allow config of SNTP server(s) by DNS name */ +#ifndef SNTP_SERVER_DNS +#define SNTP_SERVER_DNS 0 +#endif + +/** Handle support for more than one server via NTP_MAX_SERVERS, + * but catch legacy style of setting SNTP_SUPPORT_MULTIPLE_SERVERS, probably outside of this file + */ +#ifndef SNTP_SUPPORT_MULTIPLE_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 */ +#else /* SNTP_SUPPORT_MULTIPLE_SERVERS */ +/* The developer has defined SNTP_SUPPORT_MULTIPLE_SERVERS, probably from old code */ +#if SNTP_MAX_SERVERS <= 1 +#error "SNTP_MAX_SERVERS needs to be defined to the max amount of servers if SNTP_SUPPORT_MULTIPLE_SERVERS is defined" +#endif /* SNTP_MAX_SERVERS <= 1 */ +#endif /* SNTP_SUPPORT_MULTIPLE_SERVERS */ + + +/** Sanity check: + * Define this to + * - 0 to turn off sanity checks (default; smaller code) + * - >= 1 to check address and port of the response packet to ensure the + * response comes from the server we sent the request to. + * - >= 2 to check returned Originate Timestamp against Transmit Timestamp + * sent to the server (to ensure response to older request). + * - >= 3 @todo: discard reply if any of the LI, Stratum, or Transmit Timestamp + * fields is 0 or the Mode field is not 4 (unicast) or 5 (broadcast). + * - >= 4 @todo: to check that the Root Delay and Root Dispersion fields are each + * greater than or equal to 0 and less than infinity, where infinity is + * currently a cozy number like one second. This check avoids using a + * server whose synchronization source has expired for a very long time. + */ +#ifndef SNTP_CHECK_RESPONSE +#define SNTP_CHECK_RESPONSE 0 +#endif + +/** According to the RFC, this shall be a random delay + * between 1 and 5 minutes (in milliseconds) to prevent load peaks. + * This can be defined to a random generation function, + * which must return the delay in milliseconds as u32_t. + * Turned off by default. + */ +#ifndef SNTP_STARTUP_DELAY +#define SNTP_STARTUP_DELAY 0 +#endif + +/** If you want the startup delay to be a function, define this + * to a function (including the brackets) and define SNTP_STARTUP_DELAY to 1. + */ +#ifndef SNTP_STARTUP_DELAY_FUNC +#define SNTP_STARTUP_DELAY_FUNC SNTP_STARTUP_DELAY +#endif + +/** SNTP receive timeout - in milliseconds + * Also used as retry timeout - this shouldn't be too low. + * Default is 3 seconds. + */ +#ifndef SNTP_RECV_TIMEOUT +#define SNTP_RECV_TIMEOUT 3000 +#endif + +/** SNTP update delay - in milliseconds + * Default is 1 hour. + */ +#ifndef SNTP_UPDATE_DELAY +#define SNTP_UPDATE_DELAY 3600000 +#endif +#if (SNTP_UPDATE_DELAY < 15000) && !SNTP_SUPPRESS_DELAY_CHECK +#error "SNTPv4 RFC 4330 enforces a minimum update time of 15 seconds!" +#endif + +/** SNTP macro to change system time and/or the update the RTC clock */ +#ifndef SNTP_SET_SYSTEM_TIME +#define SNTP_SET_SYSTEM_TIME(sec) ((void)sec) +#endif + +/** SNTP macro to change system time including microseconds */ +#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 + +/** SNTP macro to get system time, used with SNTP_CHECK_RESPONSE >= 2 + * to send in request and compare in response. + */ +#ifndef SNTP_GET_SYSTEM_TIME +#define SNTP_GET_SYSTEM_TIME(sec, us) do { (sec) = 0; (us) = 0; } while(0) +#endif + +/** Default retry timeout (in milliseconds) if the response + * received is invalid. + * This is doubled with each retry until SNTP_RETRY_TIMEOUT_MAX is reached. + */ +#ifndef SNTP_RETRY_TIMEOUT +#define SNTP_RETRY_TIMEOUT SNTP_RECV_TIMEOUT +#endif + +/** Maximum retry timeout (in milliseconds). */ +#ifndef SNTP_RETRY_TIMEOUT_MAX +#define SNTP_RETRY_TIMEOUT_MAX (SNTP_RETRY_TIMEOUT * 10) +#endif + +/** Increase retry timeout with every retry sent + * Default is on to conform to RFC. + */ +#ifndef SNTP_RETRY_TIMEOUT_EXP +#define SNTP_RETRY_TIMEOUT_EXP 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 = 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 = 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] = 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] = 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(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, 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); + } +} + +/** + * 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(); + 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_ADDR_ANY, SNTP_PORT); + } + } + } +} + +/** + * Stop this module. + */ +void +sntp_stop(void) +{ + if (sntp_pcb != NULL) { + sys_untimeout(sntp_request, NULL); + udp_remove(sntp_pcb); + sntp_pcb = NULL; + } +} + +/** + * 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; +} + +#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 */ + +/** + * Initialize one of the NTP servers by IP address + * + * @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 +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 */ + +/** + * Obtain one of the currently configured by IP address (or DHCP) NTP servers + * + * @param numdns 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). + */ +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 */ diff --git a/src/include/lwip/apps/sntp.h b/src/include/lwip/apps/sntp.h new file mode 100644 index 00000000..40b1df0a --- /dev/null +++ b/src/include/lwip/apps/sntp.h @@ -0,0 +1,58 @@ +#ifndef LWIP_SNTP_H +#define LWIP_SNTP_H + +#include "lwip/opt.h" +#include "lwip/ip_addr.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/** The maximum number of SNTP servers that can be set */ +#ifndef SNTP_MAX_SERVERS +#define SNTP_MAX_SERVERS LWIP_DHCP_MAX_NTP_SERVERS +#endif + +/** Set this to 1 to implement the callback function called by dhcp when + * NTP servers are received. */ +#ifndef SNTP_GET_SERVERS_FROM_DHCP +#define SNTP_GET_SERVERS_FROM_DHCP LWIP_DHCP_GET_NTP_SRV +#endif + +/* Set this to 1 to support DNS names (or IP address strings) to set sntp servers */ +#ifndef SNTP_SERVER_DNS +#define SNTP_SERVER_DNS 0 +#endif + +/** One server address/name can be defined as default if SNTP_SERVER_DNS == 1: + * #define SNTP_SERVER_ADDRESS "pool.ntp.org" + */ + +/* SNTP operating modes: default is to poll using unicast. + The mode has to be set before calling sntp_init(). */ +#define SNTP_OPMODE_POLL 0 +#define SNTP_OPMODE_LISTENONLY 1 +void sntp_setoperatingmode(u8_t operating_mode); + +void sntp_init(void); +void sntp_stop(void); + +void sntp_setserver(u8_t idx, const ip_addr_t *addr); +ip_addr_t sntp_getserver(u8_t idx); + +#if SNTP_SERVER_DNS +void sntp_setservername(u8_t idx, char *server); +char *sntp_getservername(u8_t idx); +#endif /* SNTP_SERVER_DNS */ + +#if SNTP_GET_SERVERS_FROM_DHCP +void sntp_servermode_dhcp(int set_servers_from_dhcp); +#else /* SNTP_GET_SERVERS_FROM_DHCP */ +#define sntp_servermode_dhcp(x) +#endif /* SNTP_GET_SERVERS_FROM_DHCP */ + +#ifdef __cplusplus +} +#endif + +#endif /* LWIP_SNTP_H */