Simple Network Time Protocol Library¶
Overview¶
The SNTP library implements IETF RFC4330 (Simple Network Time Protocol v4).
SNTP provides a way to synchronize clocks in computer networks.
API Reference¶
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group
sntp Simple Network Time Protocol API.
Functions
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int
sntp_init(struct sntp_ctx *ctx, struct sockaddr *addr, socklen_t addr_len)¶ Initialize SNTP context.
- Parameters
ctx – Address of sntp context.
addr – IP address of NTP/SNTP server.
addr_len – IP address length of NTP/SNTP server.
- Returns
0 if ok, <0 if error.
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int
sntp_query(struct sntp_ctx *ctx, uint32_t timeout, struct sntp_time *time)¶ Perform SNTP query.
- Parameters
ctx – Address of sntp context.
timeout – Timeout of waiting for sntp response (in milliseconds).
time – Timestamp including integer and fractional seconds since 1 Jan 1970 (output).
- Returns
0 if ok, <0 if error (-ETIMEDOUT if timeout).
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void
sntp_close(struct sntp_ctx *ctx)¶ Release SNTP context.
- Parameters
ctx – Address of sntp context.
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int
sntp_simple(const char *server, uint32_t timeout, struct sntp_time *time)¶ Convenience function to query SNTP in one-shot fashion.
Convenience wrapper which calls getaddrinfo(), sntp_init(), sntp_query(), and sntp_close().
- Parameters
server – Address of server in format addr[:port]
timeout – Query timeout
time – Timestamp including integer and fractional seconds since 1 Jan 1970 (output).
- Returns
0 if ok, <0 if error (-ETIMEDOUT if timeout).
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struct
sntp_ctx¶ - #include <sntp.h>
SNTP context
Public Members
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uint32_t
expected_orig_ts¶ Timestamp when the request was sent from client to server. This is used to check if the originated timestamp in the server reply matches the one in client request.
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uint32_t
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struct
sntp_time¶ - #include <sntp.h>
Time as returned by SNTP API, fractional seconds since 1 Jan 1970
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int