ntp: add support for processing of transmitted packets
Add new functions for processing of packets after they are actually sent by the kernel or HW in order to get a more accurate transmit timestamp. Rename old functions for processing of received packets and their parameters to make the naming more consistent.
This commit is contained in:
Miroslav Lichvar
parent
a8c6bea2d5
commit
8f6a1b5318
7 changed files with 150 additions and 42 deletions
105
ntp_core.c
105
ntp_core.c
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@ -227,6 +227,9 @@ static ARR_Instance broadcasts;
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/* Maximum allowed time for server to process client packet */
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#define MAX_SERVER_INTERVAL 4.0
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/* Maximum acceptable delay in transmission for timestamp correction */
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#define MAX_TX_DELAY 1.0
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/* Minimum and maximum allowed poll interval */
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#define MIN_POLL 0
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#define MAX_POLL 24
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@ -944,7 +947,7 @@ transmit_packet(NTP_Mode my_mode, /* The mode this machine wants to be */
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UTI_TimespecToNtp64(&local_transmit, &message.transmit_ts, &ts_fuzz);
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}
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ret = NIO_SendPacket(&message, where_to, from, length);
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ret = NIO_SendPacket(&message, where_to, from, length, local_tx != NULL);
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if (local_tx) {
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*local_tx = local_transmit;
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@ -1189,7 +1192,8 @@ check_packet_auth(NTP_Packet *pkt, int length,
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/* ================================================== */
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static int
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receive_packet(NTP_Packet *message, struct timespec *now, double now_err, NCR_Instance inst, NTP_Local_Address *local_addr, int length)
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receive_packet(NTP_Packet *message, struct timespec *rx_ts, double rx_ts_err,
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NCR_Instance inst, NTP_Local_Address *local_addr, int length)
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{
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int pkt_leap;
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uint32_t pkt_refid, pkt_key_id;
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@ -1315,7 +1319,7 @@ receive_packet(NTP_Packet *message, struct timespec *now, double now_err, NCR_In
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symmetric associations using authentication */
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if (test5) {
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inst->remote_orig = message->transmit_ts;
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inst->local_rx = *now;
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inst->local_rx = *rx_ts;
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}
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/* This protects against replay of the last packet we sent */
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@ -1331,7 +1335,7 @@ receive_packet(NTP_Packet *message, struct timespec *now, double now_err, NCR_In
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UTI_AverageDiffTimespecs(&remote_receive, &remote_transmit,
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&remote_average, &remote_interval);
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UTI_AverageDiffTimespecs(&inst->local_tx, now,
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UTI_AverageDiffTimespecs(&inst->local_tx, rx_ts,
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&local_average, &local_interval);
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/* In our case, we work out 'delay' as the worst case delay,
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@ -1362,7 +1366,7 @@ receive_packet(NTP_Packet *message, struct timespec *now, double now_err, NCR_In
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skew = (source_freq_hi - source_freq_lo) / 2.0;
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/* and then calculate peer dispersion */
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dispersion = precision + now_err + skew * fabs(local_interval);
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dispersion = precision + rx_ts_err + skew * fabs(local_interval);
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/* Additional tests required to pass before accumulating the sample */
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@ -1392,7 +1396,7 @@ receive_packet(NTP_Packet *message, struct timespec *now, double now_err, NCR_In
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pkt_refid != UTI_IPToRefid(&local_addr->ip_addr);
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} else {
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offset = delay = dispersion = 0.0;
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sample_time = *now;
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sample_time = *rx_ts;
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testA = testB = testC = testD = 0;
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}
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@ -1534,8 +1538,8 @@ receive_packet(NTP_Packet *message, struct timespec *now, double now_err, NCR_In
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| Bcast Client 6 | DSCRD | DSCRD | DSCRD | DSCRD | PROC |
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+------------------+-------+-------+-------+-------+-------+
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Association mode 0 is implemented in NCR_ProcessUnknown(), other modes
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in NCR_ProcessKnown().
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Association mode 0 is implemented in NCR_ProcessRxUnknown(), other modes
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in NCR_ProcessRxKnown().
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Broadcast, manycast and ephemeral symmetric passive associations are not
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supported yet.
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@ -1546,10 +1550,10 @@ receive_packet(NTP_Packet *message, struct timespec *now, double now_err, NCR_In
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and it relates to a source we have an ongoing protocol exchange with */
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int
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NCR_ProcessKnown
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NCR_ProcessRxKnown
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(NTP_Packet *message, /* the received message */
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struct timespec *now, /* timestamp at time of receipt */
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double now_err,
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struct timespec *rx_ts, /* timestamp at time of receipt */
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double rx_ts_err,
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NCR_Instance inst, /* the instance record for this peer/server */
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NTP_Local_Address *local_addr, /* the receiving address */
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int length /* the length of the received packet */
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@ -1660,9 +1664,9 @@ NCR_ProcessKnown
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return 0;
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}
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return receive_packet(message, now, now_err, inst, local_addr, length);
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return receive_packet(message, rx_ts, rx_ts_err, inst, local_addr, length);
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} else if (proc_as_unknown) {
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NCR_ProcessUnknown(message, now, now_err, &inst->remote_addr,
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NCR_ProcessRxUnknown(message, rx_ts, rx_ts_err, &inst->remote_addr,
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local_addr, length);
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/* It's not a reply to our request, don't return success */
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return 0;
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@ -1678,10 +1682,10 @@ NCR_ProcessKnown
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and it relates to a source we don't know (not our server or peer) */
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void
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NCR_ProcessUnknown
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NCR_ProcessRxUnknown
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(NTP_Packet *message, /* the received message */
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struct timespec *now, /* timestamp at time of receipt */
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double now_err, /* assumed error in the timestamp */
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struct timespec *rx_ts, /* timestamp at time of receipt */
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double rx_ts_err, /* assumed error in the timestamp */
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NTP_Remote_Address *remote_addr,
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NTP_Local_Address *local_addr,
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int length /* the length of the received packet */
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@ -1726,7 +1730,7 @@ NCR_ProcessUnknown
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return;
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}
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log_index = CLG_LogNTPAccess(&remote_addr->ip_addr, now);
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log_index = CLG_LogNTPAccess(&remote_addr->ip_addr, rx_ts);
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/* Don't reply to all requests if the rate is excessive */
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if (log_index >= 0 && CLG_LimitNTPResponseRate(log_index)) {
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@ -1760,12 +1764,77 @@ NCR_ProcessUnknown
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- don't save our transmit timestamp as we aren't maintaining state about
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this client */
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transmit_packet(my_mode, message->poll, NTP_LVM_TO_VERSION(message->lvm),
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auth_mode, key_id, &message->transmit_ts, now, NULL, NULL,
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auth_mode, key_id, &message->transmit_ts, rx_ts, NULL, NULL,
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remote_addr, local_addr);
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}
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/* ================================================== */
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static void
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update_tx_timestamp(struct timespec *tx_ts, struct timespec *new_tx_ts,
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NTP_int64 *local_ntp_tx, NTP_Packet *message)
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{
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double delay;
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if (UTI_IsZeroTimespec(tx_ts)) {
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DEBUG_LOG(LOGF_NtpCore, "Unexpected TX update");
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return;
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}
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/* Check if this is the last packet that was sent */
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if (message->transmit_ts.hi != local_ntp_tx->hi ||
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message->transmit_ts.lo != local_ntp_tx->lo) {
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DEBUG_LOG(LOGF_NtpCore, "TX timestamp mismatch");
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return;
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}
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delay = UTI_DiffTimespecsToDouble(new_tx_ts, tx_ts);
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if (delay < 0.0 || delay > MAX_TX_DELAY) {
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DEBUG_LOG(LOGF_NtpCore, "Unacceptable TX delay %.9f", delay);
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return;
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}
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*tx_ts = *new_tx_ts;
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DEBUG_LOG(LOGF_NtpCore, "Updated TX timestamp delay=%.9f", delay);
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}
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/* ================================================== */
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void
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NCR_ProcessTxKnown(NTP_Packet *message, struct timespec *tx_ts, double tx_ts_err,
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NCR_Instance inst, NTP_Local_Address *local_addr, int length)
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{
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NTP_Mode pkt_mode;
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if (!check_packet_format(message, length))
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return;
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pkt_mode = NTP_LVM_TO_MODE(message->lvm);
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/* Server and passive mode packets are responses to unknown sources */
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if (pkt_mode != MODE_CLIENT && pkt_mode != MODE_ACTIVE) {
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NCR_ProcessTxUnknown(message, tx_ts, tx_ts_err, &inst->remote_addr,
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local_addr, length);
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return;
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}
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update_tx_timestamp(&inst->local_tx, tx_ts, &inst->local_ntp_tx, message);
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}
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/* ================================================== */
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void
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NCR_ProcessTxUnknown(NTP_Packet *message, struct timespec *tx_ts, double tx_ts_err,
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NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
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{
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/* Nothing to do yet */
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DEBUG_LOG(LOGF_NtpCore, "Process TX unknown");
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}
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/* ================================================== */
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void
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NCR_SlewTimes(NCR_Instance inst, struct timespec *when, double dfreq, double doffset)
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{
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18
ntp_core.h
18
ntp_core.h
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@ -63,11 +63,25 @@ extern void NCR_ChangeRemoteAddress(NCR_Instance inst, NTP_Remote_Address *remot
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/* This routine is called when a new packet arrives off the network,
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and it relates to a source we have an ongoing protocol exchange with */
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extern int NCR_ProcessKnown(NTP_Packet *message, struct timespec *now, double now_err, NCR_Instance data, NTP_Local_Address *local_addr, int length);
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extern int NCR_ProcessRxKnown(NTP_Packet *message, struct timespec *rx_ts, double rx_ts_err,
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NCR_Instance inst, NTP_Local_Address *local_addr, int length);
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/* This routine is called when a new packet arrives off the network,
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and we do not recognize its source */
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extern void NCR_ProcessUnknown(NTP_Packet *message, struct timespec *now, double now_err, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length);
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extern void NCR_ProcessRxUnknown(NTP_Packet *message, struct timespec *rx_ts, double rx_ts_err,
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NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
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int length);
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/* This routine is called when a packet is sent to a source we have
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an ongoing protocol exchange with */
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extern void NCR_ProcessTxKnown(NTP_Packet *message, struct timespec *tx_ts, double tx_ts_err,
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NCR_Instance inst, NTP_Local_Address *local_addr, int length);
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/* This routine is called when a packet is sent to a destination we
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do not recognize */
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extern void NCR_ProcessTxUnknown(NTP_Packet *message, struct timespec *tx_ts, double tx_ts_err,
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NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
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int length);
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/* Slew receive and transmit times in instance records */
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extern void NCR_SlewTimes(NCR_Instance inst, struct timespec *when, double dfreq, double doffset);
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26
ntp_io.c
26
ntp_io.c
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@ -548,17 +548,16 @@ NIO_IsServerSocket(int sock_fd)
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/* ================================================== */
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static void
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process_receive(struct msghdr *hdr, int length, int sock_fd)
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process_message(struct msghdr *hdr, int length, int sock_fd)
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{
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NTP_Remote_Address remote_addr;
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NTP_Local_Address local_addr;
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struct cmsghdr *cmsg;
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struct timespec sch_ts, rx_ts;
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double sch_err, rx_err;
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struct timespec local_ts, sched_ts;
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double local_ts_err;
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SCH_GetLastEventTime(&sch_ts, &sch_err, NULL);
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rx_ts = sch_ts;
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rx_err = sch_err;
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SCH_GetLastEventTime(&local_ts, &local_ts_err, NULL);
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sched_ts = local_ts;
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if (hdr->msg_namelen > sizeof (union sockaddr_in46)) {
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DEBUG_LOG(LOGF_NtpIO, "Truncated source address");
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@ -605,7 +604,7 @@ process_receive(struct msghdr *hdr, int length, int sock_fd)
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memcpy(&tv, CMSG_DATA(cmsg), sizeof(tv));
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UTI_TimevalToTimespec(&tv, &ts);
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LCL_CookTime(&ts, &rx_ts, &rx_err);
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LCL_CookTime(&ts, &local_ts, &local_ts_err);
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}
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#endif
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@ -614,22 +613,21 @@ process_receive(struct msghdr *hdr, int length, int sock_fd)
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struct timespec ts;
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memcpy(&ts, CMSG_DATA(cmsg), sizeof (ts));
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LCL_CookTime(&ts, &rx_ts, &rx_err);
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LCL_CookTime(&ts, &local_ts, &local_ts_err);
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}
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#endif
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}
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DEBUG_LOG(LOGF_NtpIO, "Received %d bytes from %s:%d to %s fd %d delay %.9f",
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DEBUG_LOG(LOGF_NtpIO, "Received %d bytes from %s:%d to %s fd=%d delay=%.9f",
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length, UTI_IPToString(&remote_addr.ip_addr), remote_addr.port,
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UTI_IPToString(&local_addr.ip_addr), local_addr.sock_fd,
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UTI_DiffTimespecsToDouble(&sch_ts, &rx_ts));
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UTI_DiffTimespecsToDouble(&sched_ts, &local_ts));
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/* Just ignore the packet if it's not of a recognized length */
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if (length < NTP_NORMAL_PACKET_LENGTH || length > sizeof (NTP_Receive_Buffer))
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return;
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NSR_ProcessReceive((NTP_Packet *)hdr->msg_iov[0].iov_base, &rx_ts, rx_err,
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NSR_ProcessRx((NTP_Packet *)hdr->msg_iov[0].iov_base, &local_ts, local_ts_err,
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&remote_addr, &local_addr, length);
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}
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@ -668,7 +666,7 @@ read_from_socket(int sock_fd, int event, void *anything)
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for (i = 0; i < n; i++) {
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hdr = ARR_GetElement(recv_headers, i);
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process_receive(&hdr->msg_hdr, hdr->msg_len, sock_fd);
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process_message(&hdr->msg_hdr, hdr->msg_len, sock_fd);
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}
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/* Restore the buffers to their original state */
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@ -680,7 +678,7 @@ read_from_socket(int sock_fd, int event, void *anything)
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int
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NIO_SendPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr,
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NTP_Local_Address *local_addr, int length)
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NTP_Local_Address *local_addr, int length, int process_tx)
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{
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union sockaddr_in46 remote;
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struct msghdr msg;
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3
ntp_io.h
3
ntp_io.h
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@ -54,6 +54,7 @@ extern void NIO_CloseServerSocket(int sock_fd);
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extern int NIO_IsServerSocket(int sock_fd);
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/* Function to transmit a packet */
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extern int NIO_SendPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length);
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extern int NIO_SendPacket(NTP_Packet *packet, NTP_Remote_Address *remote_addr,
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NTP_Local_Address *local_addr, int length, int process_tx);
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#endif /* GOT_NTP_IO_H */
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@ -193,7 +193,7 @@ process_response(SignInstance *inst)
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/* Send the signed NTP packet */
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NIO_SendPacket(&inst->response.signed_packet, &inst->remote_addr, &inst->local_addr,
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ntohl(inst->response.length) + sizeof (inst->response.length) -
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offsetof(SigndResponse, signed_packet));
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offsetof(SigndResponse, signed_packet), 0);
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/* Update exponential moving average of the authentication delay */
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delay = CLAMP(MIN_AUTH_DELAY, delay, MAX_AUTH_DELAY);
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@ -776,7 +776,8 @@ NSR_GetLocalRefid(IPAddr *address)
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/* This routine is called by ntp_io when a new packet arrives off the network,
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possibly with an authentication tail */
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void
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NSR_ProcessReceive(NTP_Packet *message, struct timespec *now, double now_err, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
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NSR_ProcessRx(NTP_Packet *message, struct timespec *rx_ts, double rx_ts_err,
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NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
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{
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SourceRecord *record;
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struct SourcePool *pool;
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@ -788,7 +789,7 @@ NSR_ProcessReceive(NTP_Packet *message, struct timespec *now, double now_err, NT
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if (found == 2) { /* Must match IP address AND port number */
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record = get_record(slot);
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if (!NCR_ProcessKnown(message, now, now_err, record->data, local_addr, length))
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if (!NCR_ProcessRxKnown(message, rx_ts, rx_ts_err, record->data, local_addr, length))
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return;
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if (record->tentative) {
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@ -809,7 +810,26 @@ NSR_ProcessReceive(NTP_Packet *message, struct timespec *now, double now_err, NT
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}
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}
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} else {
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NCR_ProcessUnknown(message, now, now_err, remote_addr, local_addr, length);
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NCR_ProcessRxUnknown(message, rx_ts, rx_ts_err, remote_addr, local_addr, length);
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}
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}
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/* ================================================== */
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void
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NSR_ProcessTx(NTP_Packet *message, struct timespec *tx_ts, double tx_ts_err,
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NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length)
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{
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SourceRecord *record;
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int slot, found;
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find_slot(remote_addr, &slot, &found);
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if (found == 2) { /* Must match IP address AND port number */
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record = get_record(slot);
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NCR_ProcessTxKnown(message, tx_ts, tx_ts_err, record->data, local_addr, length);
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} else {
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NCR_ProcessTxUnknown(message, tx_ts, tx_ts_err, remote_addr, local_addr, length);
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}
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}
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@ -87,7 +87,13 @@ extern void NSR_RefreshAddresses(void);
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extern uint32_t NSR_GetLocalRefid(IPAddr *address);
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/* This routine is called by ntp_io when a new packet arrives off the network */
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extern void NSR_ProcessReceive(NTP_Packet *message, struct timespec *now, double now_err, NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length);
|
||||
extern void NSR_ProcessRx(NTP_Packet *message, struct timespec *rx_ts, double tx_ts_err,
|
||||
NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length);
|
||||
|
||||
/* This routine is called by ntp_io when a packet was sent to the network and
|
||||
an accurate transmit timestamp was captured */
|
||||
extern void NSR_ProcessTx(NTP_Packet *message, struct timespec *tx_ts, double tx_ts_err,
|
||||
NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr, int length);
|
||||
|
||||
/* Initialisation function */
|
||||
extern void NSR_Initialise(void);
|
||||
|
|
|
|||
Loading…
Reference in a new issue