--- /dev/null
+// Copyright (C) 2015 Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#include <cmath>
+#include <util/ntp_utils.h>
+
+namespace isc {
+namespace util {
+
+namespace {
+
+// \brief seconds between 1900 and 1970 epochs
+const uint32_t EPOCH_ADJUST = 2208988800UL;
+
+// \brief Allowed delta (300s / 5mn)
+const double DELTA = 300.;
+
+// \brief Allowed fuzz factor (1s)
+const double FUZZ = 1.;
+
+// \brief Allowed clock drift (.01s)
+const double DRIFT = .01;
+}
+
+Ntp::Ntp() : ntp_sec_(0), ntp_fraction_(0)
+{
+}
+
+Ntp::Ntp(uint64_t sec, uint16_t fraction)
+ : ntp_sec_(sec), ntp_fraction_(fraction)
+{
+}
+
+Ntp::Ntp(struct timeval tv)
+{
+ ntp_sec_ = static_cast<uint32_t>(tv.tv_sec) + EPOCH_ADJUST;
+ uint32_t fcvt = (tv.tv_usec * 65536U) / 1000000UL;
+ ntp_fraction_ = static_cast<uint16_t>(fcvt & 0xffff);
+}
+
+Ntp::Ntp(double secs, time_t base)
+{
+ double intpart;
+ double fracpart = std::modf(secs, &intpart);
+ ntp_sec_ = static_cast<uint64_t>(intpart) + base + EPOCH_ADJUST;
+ ntp_fraction_ = static_cast<uint16_t>(floor(fracpart * 65536.));
+}
+
+bool Ntp::from_binary(std::vector<uint8_t> binary)
+{
+ if (binary.size() != 8) {
+ return (false);
+ }
+ ntp_sec_ = static_cast<uint64_t>(binary[0]) << 40;
+ ntp_sec_ |= static_cast<uint64_t>(binary[1]) << 32;
+ ntp_sec_ |= binary[2] << 24;
+ ntp_sec_ |= binary[3] << 16;
+ ntp_sec_ |= binary[4] << 8;
+ ntp_sec_ |= binary[5];
+ ntp_fraction_ = binary[6] << 8;
+ ntp_fraction_ |= binary[7];
+ return (true);
+}
+
+std::vector<uint8_t> Ntp::to_binary() const
+{
+ std::vector<uint8_t> ret(8);
+ ret[0] = static_cast<uint8_t>((ntp_sec_ >> 40) & 0xff);
+ ret[1] = static_cast<uint8_t>((ntp_sec_ >> 32) & 0xff);
+ ret[2] = static_cast<uint8_t>((ntp_sec_ >> 24) & 0xff);
+ ret[3] = static_cast<uint8_t>((ntp_sec_ >> 16) & 0xff);
+ ret[4] = static_cast<uint8_t>((ntp_sec_ >> 8) & 0xff);
+ ret[5] = static_cast<uint8_t>(ntp_sec_ & 0xff);
+ ret[6] = static_cast<uint8_t>((ntp_fraction_ >> 8) & 0xff);
+ ret[7] = static_cast<uint8_t>(ntp_fraction_ & 0xff);
+ return (ret);
+}
+
+double Ntp::secs(time_t base) const
+{
+ double ret = static_cast<double>(ntp_sec_ - base - EPOCH_ADJUST);
+ ret += static_cast<double>(ntp_fraction_ * (1./65536.));
+ return (ret);
+}
+
+bool Ntp::verify_new(const Ntp& rd_new, const Ntp& ts_new, time_t base)
+{
+ double drd_new = rd_new.secs(base);
+ double dts_new = ts_new.secs(base);
+ if (drd_new >= dts_new) {
+ if ((drd_new - dts_new) < DELTA) {
+ return (true);
+ } else {
+ return (false);
+ }
+ } else {
+ if ((dts_new - drd_new) < DELTA) {
+ return (true);
+ } else {
+ return (false);
+ }
+ }
+}
+
+bool Ntp::verify(const Ntp& rd_new, const Ntp& ts_new,
+ const Ntp& rd_last, const Ntp& ts_last,
+ time_t base, bool* to_update)
+{
+ double drd_new = rd_new.secs(base);
+ double drd_last = rd_last.secs(base);
+ if (drd_new < drd_last) {
+ return (false);
+ }
+ double dts_new = ts_new.secs(base);
+ double dts_last = ts_last.secs(base);
+ double expected = dts_last - FUZZ;
+ expected += (drd_new - drd_last) * (1. - DRIFT);
+ if (expected >= dts_new + FUZZ) {
+ return (false);
+ } else {
+ if (dts_new > dts_last) {
+ *to_update = true;
+ }
+ return (true);
+ }
+}
+
+}
+}
--- /dev/null
+// Copyright (C) 2015 Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#ifndef KEA_NTP_UTILS_H
+#define KEA_NTP_UTILS_H
+
+#include <string>
+#include <vector>
+
+#include <stdint.h>
+#include <sys/time.h>
+
+namespace isc {
+namespace util {
+
+///
+/// \brief NTP (RFC 5905) time
+///
+/// External representation: uint64_t seconds, uint16_t fractional
+/// Network representation: 48+16 bit unsigned fixed point
+struct Ntp {
+ // \brief seconds sinec 1900
+ uint64_t ntp_sec_;
+
+ // \brief 1/65536th of seconds
+ uint16_t ntp_fraction_;
+
+ // \brief Default constructor
+ Ntp();
+
+ // \brief Standard constructor
+ Ntp(uint64_t sec, uint16_t fraction);
+
+ // \brief Conversion from timeval
+ Ntp(struct timeval tv);
+
+ // \brief Conversion from based double
+ Ntp(double secs, time_t base);
+
+ // \brief Conversion from network
+ bool from_binary(std::vector<uint8_t> binary);
+
+ // \brief Conversion to network
+ std::vector<uint8_t> to_binary() const;
+
+ // \brief Conversion to based double
+ double secs(time_t base) const;
+
+ // \brief Verify a timestamp without cache
+ static bool verify_new(const Ntp& rd_new, const Ntp& ts_new, time_t base);
+
+ // \brief Verify a timestamp with cache
+ static bool verify(const Ntp& rd_new, const Ntp& ts_new,
+ const Ntp& rd_last, const Ntp& ts_last,
+ time_t base, bool* to_update);
+};
+
+} // end of isc::util namespace
+} // end of isc namespace
+
+#endif // KEA_NTP_UTILS_H
projects / thirdparty / kea.git / commitdiff
