From: jow Date: Thu, 27 Oct 2011 00:53:01 +0000 (+0000) Subject: [backfire] busybox: backport ntpd applet from trunk busybox, keep it disabled for now X-Git-Url: http://207.154.207.93/?a=commitdiff_plain;h=bb0ebee8414b0d391ef59cd4f7dc0a756ca12b00;p=10.03%2Fopenwrt.git [backfire] busybox: backport ntpd applet from trunk busybox, keep it disabled for now git-svn-id: svn://svn.openwrt.org/openwrt/branches/backfire@28614 3c298f89-4303-0410-b956-a3cf2f4a3e73 --- diff --git a/package/busybox/Makefile b/package/busybox/Makefile index 2833542ca..ef3b37176 100644 --- a/package/busybox/Makefile +++ b/package/busybox/Makefile @@ -1,5 +1,5 @@ # -# Copyright (C) 2006-2009 OpenWrt.org +# Copyright (C) 2006-2011 OpenWrt.org # # This is free software, licensed under the GNU General Public License v2. # See /LICENSE for more information. @@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk PKG_NAME:=busybox PKG_VERSION:=1.15.3 -PKG_RELEASE:=2 +PKG_RELEASE:=3 PKG_FLAGS:=essential PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2 diff --git a/package/busybox/config/networking/Config.in b/package/busybox/config/networking/Config.in index 77a7b07c3..ea72f2de5 100644 --- a/package/busybox/config/networking/Config.in +++ b/package/busybox/config/networking/Config.in @@ -667,6 +667,20 @@ config BUSYBOX_CONFIG_NSLOOKUP help nslookup is a tool to query Internet name servers. +config BUSYBOX_CONFIG_NTPD + bool "ntpd" + default n + help + The NTP client/server daemon. + +config BUSYBOX_CONFIG_FEATURE_NTPD_SERVER + bool "Make ntpd usable as a NTP server" + default n + depends on BUSYBOX_CONFIG_NTPD + help + Make ntpd usable as a NTP server. If you disable this option + ntpd will be usable only as a NTP client. + config BUSYBOX_CONFIG_PING bool "ping" default y diff --git a/package/busybox/patches/920-backport-ntpd.patch b/package/busybox/patches/920-backport-ntpd.patch new file mode 100644 index 000000000..e9a40ee12 --- /dev/null +++ b/package/busybox/patches/920-backport-ntpd.patch @@ -0,0 +1,2333 @@ +--- a/include/applets.h ++++ b/include/applets.h +@@ -285,6 +285,7 @@ IF_NICE(APPLET(nice, _BB_DIR_BIN, _BB_SU + IF_NMETER(APPLET(nmeter, _BB_DIR_USR_BIN, _BB_SUID_DROP)) + IF_NOHUP(APPLET(nohup, _BB_DIR_USR_BIN, _BB_SUID_DROP)) + IF_NSLOOKUP(APPLET(nslookup, _BB_DIR_USR_BIN, _BB_SUID_DROP)) ++IF_NTPD(APPLET(ntpd, _BB_DIR_USR_SBIN, _BB_SUID_DROP)) + IF_OD(APPLET(od, _BB_DIR_USR_BIN, _BB_SUID_DROP)) + IF_OPENVT(APPLET(openvt, _BB_DIR_USR_BIN, _BB_SUID_DROP)) + //IF_PARSE(APPLET(parse, _BB_DIR_USR_BIN, _BB_SUID_DROP)) +--- a/include/usage.h ++++ b/include/usage.h +@@ -3183,6 +3183,22 @@ + "Name: debian\n" \ + "Address: 127.0.0.1\n" + ++#define ntpd_trivial_usage \ ++ "[-dnqNw"IF_FEATURE_NTPD_SERVER("l")"] [-S PROG] [-p PEER]..." ++#define ntpd_full_usage "\n\n" \ ++ "NTP client/server\n" \ ++ "\nOptions:" \ ++ "\n -d Verbose" \ ++ "\n -n Do not daemonize" \ ++ "\n -q Quit after clock is set" \ ++ "\n -N Run at high priority" \ ++ "\n -w Do not set time (only query peers), implies -n" \ ++ IF_FEATURE_NTPD_SERVER( \ ++ "\n -l Run as server on port 123" \ ++ ) \ ++ "\n -S PROG Run PROG after stepping time, stratum change, and every 11 mins" \ ++ "\n -p PEER Obtain time from PEER (may be repeated)" ++ + #define od_trivial_usage \ + "[-aBbcDdeFfHhIiLlOovXx] " IF_DESKTOP("[-t TYPE] ") "[FILE]" + #define od_full_usage "\n\n" \ +--- a/networking/Config.in ++++ b/networking/Config.in +@@ -667,6 +667,20 @@ config NSLOOKUP + help + nslookup is a tool to query Internet name servers. + ++config NTPD ++ bool "ntpd" ++ default y ++ help ++ The NTP client/server daemon. ++ ++config FEATURE_NTPD_SERVER ++ bool "Make ntpd usable as a NTP server" ++ default y ++ depends on NTPD ++ help ++ Make ntpd usable as a NTP server. If you disable this option ++ ntpd will be usable only as a NTP client. ++ + config PING + bool "ping" + default n +--- /dev/null ++++ b/networking/ntpd.c +@@ -0,0 +1,2262 @@ ++/* ++ * NTP client/server, based on OpenNTPD 3.9p1 ++ * ++ * Author: Adam Tkac ++ * ++ * Licensed under GPLv2, see file LICENSE in this source tree. ++ * ++ * Parts of OpenNTPD clock syncronization code is replaced by ++ * code which is based on ntp-4.2.6, whuch carries the following ++ * copyright notice: ++ * ++ *********************************************************************** ++ * * ++ * Copyright (c) University of Delaware 1992-2009 * ++ * * ++ * Permission to use, copy, modify, and distribute this software and * ++ * its documentation for any purpose with or without fee is hereby * ++ * granted, provided that the above copyright notice appears in all * ++ * copies and that both the copyright notice and this permission * ++ * notice appear in supporting documentation, and that the name * ++ * University of Delaware not be used in advertising or publicity * ++ * pertaining to distribution of the software without specific, * ++ * written prior permission. The University of Delaware makes no * ++ * representations about the suitability this software for any * ++ * purpose. It is provided "as is" without express or implied * ++ * warranty. * ++ * * ++ *********************************************************************** ++ */ ++#include "libbb.h" ++#include ++#include /* For IPTOS_LOWDELAY definition */ ++#include ++#ifndef IPTOS_LOWDELAY ++# define IPTOS_LOWDELAY 0x10 ++#endif ++#ifndef IP_PKTINFO ++# error "Sorry, your kernel has to support IP_PKTINFO" ++#endif ++ ++ ++/* Verbosity control (max level of -dddd options accepted). ++ * max 5 is very talkative (and bloated). 2 is non-bloated, ++ * production level setting. ++ */ ++#define MAX_VERBOSE 2 ++ ++ ++/* High-level description of the algorithm: ++ * ++ * We start running with very small poll_exp, BURSTPOLL, ++ * in order to quickly accumulate INITIAL_SAMPLES datapoints ++ * for each peer. Then, time is stepped if the offset is larger ++ * than STEP_THRESHOLD, otherwise it isn't; anyway, we enlarge ++ * poll_exp to MINPOLL and enter frequency measurement step: ++ * we collect new datapoints but ignore them for WATCH_THRESHOLD ++ * seconds. After WATCH_THRESHOLD seconds we look at accumulated ++ * offset and estimate frequency drift. ++ * ++ * (frequency measurement step seems to not be strictly needed, ++ * it is conditionally disabled with USING_INITIAL_FREQ_ESTIMATION ++ * define set to 0) ++ * ++ * After this, we enter "steady state": we collect a datapoint, ++ * we select the best peer, if this datapoint is not a new one ++ * (IOW: if this datapoint isn't for selected peer), sleep ++ * and collect another one; otherwise, use its offset to update ++ * frequency drift, if offset is somewhat large, reduce poll_exp, ++ * otherwise increase poll_exp. ++ * ++ * If offset is larger than STEP_THRESHOLD, which shouldn't normally ++ * happen, we assume that something "bad" happened (computer ++ * was hibernated, someone set totally wrong date, etc), ++ * then the time is stepped, all datapoints are discarded, ++ * and we go back to steady state. ++ */ ++ ++#define RETRY_INTERVAL 5 /* on error, retry in N secs */ ++#define RESPONSE_INTERVAL 15 /* wait for reply up to N secs */ ++#define INITIAL_SAMPLES 4 /* how many samples do we want for init */ ++ ++/* Clock discipline parameters and constants */ ++ ++/* Step threshold (sec). std ntpd uses 0.128. ++ * Using exact power of 2 (1/8) results in smaller code */ ++#define STEP_THRESHOLD 0.125 ++#define WATCH_THRESHOLD 128 /* stepout threshold (sec). std ntpd uses 900 (11 mins (!)) */ ++/* NB: set WATCH_THRESHOLD to ~60 when debugging to save time) */ ++//UNUSED: #define PANIC_THRESHOLD 1000 /* panic threshold (sec) */ ++ ++#define FREQ_TOLERANCE 0.000015 /* frequency tolerance (15 PPM) */ ++#define BURSTPOLL 0 /* initial poll */ ++#define MINPOLL 5 /* minimum poll interval. std ntpd uses 6 (6: 64 sec) */ ++#define BIGPOLL 10 /* drop to lower poll at any trouble (10: 17 min) */ ++#define MAXPOLL 12 /* maximum poll interval (12: 1.1h, 17: 36.4h). std ntpd uses 17 */ ++/* Actively lower poll when we see such big offsets. ++ * With STEP_THRESHOLD = 0.125, it means we try to sync more aggressively ++ * if offset increases over 0.03 sec */ ++#define POLLDOWN_OFFSET (STEP_THRESHOLD / 4) ++#define MINDISP 0.01 /* minimum dispersion (sec) */ ++#define MAXDISP 16 /* maximum dispersion (sec) */ ++#define MAXSTRAT 16 /* maximum stratum (infinity metric) */ ++#define MAXDIST 1 /* distance threshold (sec) */ ++#define MIN_SELECTED 1 /* minimum intersection survivors */ ++#define MIN_CLUSTERED 3 /* minimum cluster survivors */ ++ ++#define MAXDRIFT 0.000500 /* frequency drift we can correct (500 PPM) */ ++ ++/* Poll-adjust threshold. ++ * When we see that offset is small enough compared to discipline jitter, ++ * we grow a counter: += MINPOLL. When it goes over POLLADJ_LIMIT, ++ * we poll_exp++. If offset isn't small, counter -= poll_exp*2, ++ * and when it goes below -POLLADJ_LIMIT, we poll_exp-- ++ * (bumped from 30 to 36 since otherwise I often see poll_exp going *2* steps down) ++ */ ++#define POLLADJ_LIMIT 36 ++/* If offset < POLLADJ_GATE * discipline_jitter, then we can increase ++ * poll interval (we think we can't improve timekeeping ++ * by staying at smaller poll). ++ */ ++#define POLLADJ_GATE 4 ++/* Compromise Allan intercept (sec). doc uses 1500, std ntpd uses 512 */ ++#define ALLAN 512 ++/* PLL loop gain */ ++#define PLL 65536 ++/* FLL loop gain [why it depends on MAXPOLL??] */ ++#define FLL (MAXPOLL + 1) ++/* Parameter averaging constant */ ++#define AVG 4 ++ ++ ++enum { ++ NTP_VERSION = 4, ++ NTP_MAXSTRATUM = 15, ++ ++ NTP_DIGESTSIZE = 16, ++ NTP_MSGSIZE_NOAUTH = 48, ++ NTP_MSGSIZE = (NTP_MSGSIZE_NOAUTH + 4 + NTP_DIGESTSIZE), ++ ++ /* Status Masks */ ++ MODE_MASK = (7 << 0), ++ VERSION_MASK = (7 << 3), ++ VERSION_SHIFT = 3, ++ LI_MASK = (3 << 6), ++ ++ /* Leap Second Codes (high order two bits of m_status) */ ++ LI_NOWARNING = (0 << 6), /* no warning */ ++ LI_PLUSSEC = (1 << 6), /* add a second (61 seconds) */ ++ LI_MINUSSEC = (2 << 6), /* minus a second (59 seconds) */ ++ LI_ALARM = (3 << 6), /* alarm condition */ ++ ++ /* Mode values */ ++ MODE_RES0 = 0, /* reserved */ ++ MODE_SYM_ACT = 1, /* symmetric active */ ++ MODE_SYM_PAS = 2, /* symmetric passive */ ++ MODE_CLIENT = 3, /* client */ ++ MODE_SERVER = 4, /* server */ ++ MODE_BROADCAST = 5, /* broadcast */ ++ MODE_RES1 = 6, /* reserved for NTP control message */ ++ MODE_RES2 = 7, /* reserved for private use */ ++}; ++ ++//TODO: better base selection ++#define OFFSET_1900_1970 2208988800UL /* 1970 - 1900 in seconds */ ++ ++#define NUM_DATAPOINTS 8 ++ ++typedef struct { ++ uint32_t int_partl; ++ uint32_t fractionl; ++} l_fixedpt_t; ++ ++typedef struct { ++ uint16_t int_parts; ++ uint16_t fractions; ++} s_fixedpt_t; ++ ++typedef struct { ++ uint8_t m_status; /* status of local clock and leap info */ ++ uint8_t m_stratum; ++ uint8_t m_ppoll; /* poll value */ ++ int8_t m_precision_exp; ++ s_fixedpt_t m_rootdelay; ++ s_fixedpt_t m_rootdisp; ++ uint32_t m_refid; ++ l_fixedpt_t m_reftime; ++ l_fixedpt_t m_orgtime; ++ l_fixedpt_t m_rectime; ++ l_fixedpt_t m_xmttime; ++ uint32_t m_keyid; ++ uint8_t m_digest[NTP_DIGESTSIZE]; ++} msg_t; ++ ++typedef struct { ++ double d_recv_time; ++ double d_offset; ++ double d_dispersion; ++} datapoint_t; ++ ++typedef struct { ++ len_and_sockaddr *p_lsa; ++ char *p_dotted; ++ /* when to send new query (if p_fd == -1) ++ * or when receive times out (if p_fd >= 0): */ ++ int p_fd; ++ int datapoint_idx; ++ uint32_t lastpkt_refid; ++ uint8_t lastpkt_status; ++ uint8_t lastpkt_stratum; ++ uint8_t reachable_bits; ++ double next_action_time; ++ double p_xmttime; ++ double lastpkt_recv_time; ++ double lastpkt_delay; ++ double lastpkt_rootdelay; ++ double lastpkt_rootdisp; ++ /* produced by filter algorithm: */ ++ double filter_offset; ++ double filter_dispersion; ++ double filter_jitter; ++ datapoint_t filter_datapoint[NUM_DATAPOINTS]; ++ /* last sent packet: */ ++ msg_t p_xmt_msg; ++} peer_t; ++ ++ ++#define USING_KERNEL_PLL_LOOP 1 ++#define USING_INITIAL_FREQ_ESTIMATION 0 ++ ++enum { ++ OPT_n = (1 << 0), ++ OPT_q = (1 << 1), ++ OPT_N = (1 << 2), ++ OPT_x = (1 << 3), ++ /* Insert new options above this line. */ ++ /* Non-compat options: */ ++ OPT_w = (1 << 4), ++ OPT_p = (1 << 5), ++ OPT_S = (1 << 6), ++ OPT_l = (1 << 7) * ENABLE_FEATURE_NTPD_SERVER, ++}; ++ ++struct globals { ++ double cur_time; ++ /* total round trip delay to currently selected reference clock */ ++ double rootdelay; ++ /* reference timestamp: time when the system clock was last set or corrected */ ++ double reftime; ++ /* total dispersion to currently selected reference clock */ ++ double rootdisp; ++ ++ double last_script_run; ++ char *script_name; ++ llist_t *ntp_peers; ++#if ENABLE_FEATURE_NTPD_SERVER ++ int listen_fd; ++#endif ++ unsigned verbose; ++ unsigned peer_cnt; ++ /* refid: 32-bit code identifying the particular server or reference clock ++ * in stratum 0 packets this is a four-character ASCII string, ++ * called the kiss code, used for debugging and monitoring ++ * in stratum 1 packets this is a four-character ASCII string ++ * assigned to the reference clock by IANA. Example: "GPS " ++ * in stratum 2+ packets, it's IPv4 address or 4 first bytes of MD5 hash of IPv6 ++ */ ++ uint32_t refid; ++ uint8_t ntp_status; ++ /* precision is defined as the larger of the resolution and time to ++ * read the clock, in log2 units. For instance, the precision of a ++ * mains-frequency clock incrementing at 60 Hz is 16 ms, even when the ++ * system clock hardware representation is to the nanosecond. ++ * ++ * Delays, jitters of various kinds are clamper down to precision. ++ * ++ * If precision_sec is too large, discipline_jitter gets clamped to it ++ * and if offset is much smaller than discipline_jitter, poll interval ++ * grows even though we really can benefit from staying at smaller one, ++ * collecting non-lagged datapoits and correcting the offset. ++ * (Lagged datapoits exist when poll_exp is large but we still have ++ * systematic offset error - the time distance between datapoints ++ * is significat and older datapoints have smaller offsets. ++ * This makes our offset estimation a bit smaller than reality) ++ * Due to this effect, setting G_precision_sec close to ++ * STEP_THRESHOLD isn't such a good idea - offsets may grow ++ * too big and we will step. I observed it with -6. ++ * ++ * OTOH, setting precision too small would result in futile attempts ++ * to syncronize to the unachievable precision. ++ * ++ * -6 is 1/64 sec, -7 is 1/128 sec and so on. ++ */ ++#define G_precision_exp -8 ++#define G_precision_sec (1.0 / (1 << (- G_precision_exp))) ++ uint8_t stratum; ++ /* Bool. After set to 1, never goes back to 0: */ ++ smallint initial_poll_complete; ++ ++#define STATE_NSET 0 /* initial state, "nothing is set" */ ++//#define STATE_FSET 1 /* frequency set from file */ ++#define STATE_SPIK 2 /* spike detected */ ++//#define STATE_FREQ 3 /* initial frequency */ ++#define STATE_SYNC 4 /* clock synchronized (normal operation) */ ++ uint8_t discipline_state; // doc calls it c.state ++ uint8_t poll_exp; // s.poll ++ int polladj_count; // c.count ++ long kernel_freq_drift; ++ peer_t *last_update_peer; ++ double last_update_offset; // c.last ++ double last_update_recv_time; // s.t ++ double discipline_jitter; // c.jitter ++ //double cluster_offset; // s.offset ++ //double cluster_jitter; // s.jitter ++#if !USING_KERNEL_PLL_LOOP ++ double discipline_freq_drift; // c.freq ++ /* Maybe conditionally calculate wander? it's used only for logging */ ++ double discipline_wander; // c.wander ++#endif ++}; ++#define G (*ptr_to_globals) ++ ++static const int const_IPTOS_LOWDELAY = IPTOS_LOWDELAY; ++ ++ ++#define VERB1 if (MAX_VERBOSE && G.verbose) ++#define VERB2 if (MAX_VERBOSE >= 2 && G.verbose >= 2) ++#define VERB3 if (MAX_VERBOSE >= 3 && G.verbose >= 3) ++#define VERB4 if (MAX_VERBOSE >= 4 && G.verbose >= 4) ++#define VERB5 if (MAX_VERBOSE >= 5 && G.verbose >= 5) ++ ++ ++static double LOG2D(int a) ++{ ++ if (a < 0) ++ return 1.0 / (1UL << -a); ++ return 1UL << a; ++} ++static ALWAYS_INLINE double SQUARE(double x) ++{ ++ return x * x; ++} ++static ALWAYS_INLINE double MAXD(double a, double b) ++{ ++ if (a > b) ++ return a; ++ return b; ++} ++static ALWAYS_INLINE double MIND(double a, double b) ++{ ++ if (a < b) ++ return a; ++ return b; ++} ++static NOINLINE double my_SQRT(double X) ++{ ++ union { ++ float f; ++ int32_t i; ++ } v; ++ double invsqrt; ++ double Xhalf = X * 0.5; ++ ++ /* Fast and good approximation to 1/sqrt(X), black magic */ ++ v.f = X; ++ /*v.i = 0x5f3759df - (v.i >> 1);*/ ++ v.i = 0x5f375a86 - (v.i >> 1); /* - this constant is slightly better */ ++ invsqrt = v.f; /* better than 0.2% accuracy */ ++ ++ /* Refining it using Newton's method: x1 = x0 - f(x0)/f'(x0) ++ * f(x) = 1/(x*x) - X (f==0 when x = 1/sqrt(X)) ++ * f'(x) = -2/(x*x*x) ++ * f(x)/f'(x) = (X - 1/(x*x)) / (2/(x*x*x)) = X*x*x*x/2 - x/2 ++ * x1 = x0 - (X*x0*x0*x0/2 - x0/2) = 1.5*x0 - X*x0*x0*x0/2 = x0*(1.5 - (X/2)*x0*x0) ++ */ ++ invsqrt = invsqrt * (1.5 - Xhalf * invsqrt * invsqrt); /* ~0.05% accuracy */ ++ /* invsqrt = invsqrt * (1.5 - Xhalf * invsqrt * invsqrt); 2nd iter: ~0.0001% accuracy */ ++ /* With 4 iterations, more than half results will be exact, ++ * at 6th iterations result stabilizes with about 72% results exact. ++ * We are well satisfied with 0.05% accuracy. ++ */ ++ ++ return X * invsqrt; /* X * 1/sqrt(X) ~= sqrt(X) */ ++} ++static ALWAYS_INLINE double SQRT(double X) ++{ ++ /* If this arch doesn't use IEEE 754 floats, fall back to using libm */ ++ if (sizeof(float) != 4) ++ return sqrt(X); ++ ++ /* This avoids needing libm, saves about 0.5k on x86-32 */ ++ return my_SQRT(X); ++} ++ ++static double ++gettime1900d(void) ++{ ++ struct timeval tv; ++ gettimeofday(&tv, NULL); /* never fails */ ++ G.cur_time = tv.tv_sec + (1.0e-6 * tv.tv_usec) + OFFSET_1900_1970; ++ return G.cur_time; ++} ++ ++static void ++d_to_tv(double d, struct timeval *tv) ++{ ++ tv->tv_sec = (long)d; ++ tv->tv_usec = (d - tv->tv_sec) * 1000000; ++} ++ ++static double ++lfp_to_d(l_fixedpt_t lfp) ++{ ++ double ret; ++ lfp.int_partl = ntohl(lfp.int_partl); ++ lfp.fractionl = ntohl(lfp.fractionl); ++ ret = (double)lfp.int_partl + ((double)lfp.fractionl / UINT_MAX); ++ return ret; ++} ++static double ++sfp_to_d(s_fixedpt_t sfp) ++{ ++ double ret; ++ sfp.int_parts = ntohs(sfp.int_parts); ++ sfp.fractions = ntohs(sfp.fractions); ++ ret = (double)sfp.int_parts + ((double)sfp.fractions / USHRT_MAX); ++ return ret; ++} ++#if ENABLE_FEATURE_NTPD_SERVER ++static l_fixedpt_t ++d_to_lfp(double d) ++{ ++ l_fixedpt_t lfp; ++ lfp.int_partl = (uint32_t)d; ++ lfp.fractionl = (uint32_t)((d - lfp.int_partl) * UINT_MAX); ++ lfp.int_partl = htonl(lfp.int_partl); ++ lfp.fractionl = htonl(lfp.fractionl); ++ return lfp; ++} ++static s_fixedpt_t ++d_to_sfp(double d) ++{ ++ s_fixedpt_t sfp; ++ sfp.int_parts = (uint16_t)d; ++ sfp.fractions = (uint16_t)((d - sfp.int_parts) * USHRT_MAX); ++ sfp.int_parts = htons(sfp.int_parts); ++ sfp.fractions = htons(sfp.fractions); ++ return sfp; ++} ++#endif ++ ++static double ++dispersion(const datapoint_t *dp) ++{ ++ return dp->d_dispersion + FREQ_TOLERANCE * (G.cur_time - dp->d_recv_time); ++} ++ ++static double ++root_distance(peer_t *p) ++{ ++ /* The root synchronization distance is the maximum error due to ++ * all causes of the local clock relative to the primary server. ++ * It is defined as half the total delay plus total dispersion ++ * plus peer jitter. ++ */ ++ return MAXD(MINDISP, p->lastpkt_rootdelay + p->lastpkt_delay) / 2 ++ + p->lastpkt_rootdisp ++ + p->filter_dispersion ++ + FREQ_TOLERANCE * (G.cur_time - p->lastpkt_recv_time) ++ + p->filter_jitter; ++} ++ ++static void ++set_next(peer_t *p, unsigned t) ++{ ++ p->next_action_time = G.cur_time + t; ++} ++ ++/* ++ * Peer clock filter and its helpers ++ */ ++static void ++filter_datapoints(peer_t *p) ++{ ++ int i, idx; ++ int got_newest; ++ double minoff, maxoff, wavg, sum, w; ++ double x = x; /* for compiler */ ++ double oldest_off = oldest_off; ++ double oldest_age = oldest_age; ++ double newest_off = newest_off; ++ double newest_age = newest_age; ++ ++ minoff = maxoff = p->filter_datapoint[0].d_offset; ++ for (i = 1; i < NUM_DATAPOINTS; i++) { ++ if (minoff > p->filter_datapoint[i].d_offset) ++ minoff = p->filter_datapoint[i].d_offset; ++ if (maxoff < p->filter_datapoint[i].d_offset) ++ maxoff = p->filter_datapoint[i].d_offset; ++ } ++ ++ idx = p->datapoint_idx; /* most recent datapoint */ ++ /* Average offset: ++ * Drop two outliers and take weighted average of the rest: ++ * most_recent/2 + older1/4 + older2/8 ... + older5/32 + older6/32 ++ * we use older6/32, not older6/64 since sum of weights should be 1: ++ * 1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/32 = 1 ++ */ ++ wavg = 0; ++ w = 0.5; ++ /* n-1 ++ * --- dispersion(i) ++ * filter_dispersion = \ ------------- ++ * / (i+1) ++ * --- 2 ++ * i=0 ++ */ ++ got_newest = 0; ++ sum = 0; ++ for (i = 0; i < NUM_DATAPOINTS; i++) { ++ VERB4 { ++ bb_error_msg("datapoint[%d]: off:%f disp:%f(%f) age:%f%s", ++ i, ++ p->filter_datapoint[idx].d_offset, ++ p->filter_datapoint[idx].d_dispersion, dispersion(&p->filter_datapoint[idx]), ++ G.cur_time - p->filter_datapoint[idx].d_recv_time, ++ (minoff == p->filter_datapoint[idx].d_offset || maxoff == p->filter_datapoint[idx].d_offset) ++ ? " (outlier by offset)" : "" ++ ); ++ } ++ ++ sum += dispersion(&p->filter_datapoint[idx]) / (2 << i); ++ ++ if (minoff == p->filter_datapoint[idx].d_offset) { ++ minoff -= 1; /* so that we don't match it ever again */ ++ } else ++ if (maxoff == p->filter_datapoint[idx].d_offset) { ++ maxoff += 1; ++ } else { ++ oldest_off = p->filter_datapoint[idx].d_offset; ++ oldest_age = G.cur_time - p->filter_datapoint[idx].d_recv_time; ++ if (!got_newest) { ++ got_newest = 1; ++ newest_off = oldest_off; ++ newest_age = oldest_age; ++ } ++ x = oldest_off * w; ++ wavg += x; ++ w /= 2; ++ } ++ ++ idx = (idx - 1) & (NUM_DATAPOINTS - 1); ++ } ++ p->filter_dispersion = sum; ++ wavg += x; /* add another older6/64 to form older6/32 */ ++ /* Fix systematic underestimation with large poll intervals. ++ * Imagine that we still have a bit of uncorrected drift, ++ * and poll interval is big (say, 100 sec). Offsets form a progression: ++ * 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 - 0.7 is most recent. ++ * The algorithm above drops 0.0 and 0.7 as outliers, ++ * and then we have this estimation, ~25% off from 0.7: ++ * 0.1/32 + 0.2/32 + 0.3/16 + 0.4/8 + 0.5/4 + 0.6/2 = 0.503125 ++ */ ++ x = oldest_age - newest_age; ++ if (x != 0) { ++ x = newest_age / x; /* in above example, 100 / (600 - 100) */ ++ if (x < 1) { /* paranoia check */ ++ x = (newest_off - oldest_off) * x; /* 0.5 * 100/500 = 0.1 */ ++ wavg += x; ++ } ++ } ++ p->filter_offset = wavg; ++ ++ /* +----- -----+ ^ 1/2 ++ * | n-1 | ++ * | --- | ++ * | 1 \ 2 | ++ * filter_jitter = | --- * / (avg-offset_j) | ++ * | n --- | ++ * | j=0 | ++ * +----- -----+ ++ * where n is the number of valid datapoints in the filter (n > 1); ++ * if filter_jitter < precision then filter_jitter = precision ++ */ ++ sum = 0; ++ for (i = 0; i < NUM_DATAPOINTS; i++) { ++ sum += SQUARE(wavg - p->filter_datapoint[i].d_offset); ++ } ++ sum = SQRT(sum / NUM_DATAPOINTS); ++ p->filter_jitter = sum > G_precision_sec ? sum : G_precision_sec; ++ ++ VERB3 bb_error_msg("filter offset:%f(corr:%e) disp:%f jitter:%f", ++ p->filter_offset, x, ++ p->filter_dispersion, ++ p->filter_jitter); ++} ++ ++static void ++reset_peer_stats(peer_t *p, double offset) ++{ ++ int i; ++ bool small_ofs = fabs(offset) < 16 * STEP_THRESHOLD; ++ ++ for (i = 0; i < NUM_DATAPOINTS; i++) { ++ if (small_ofs) { ++ p->filter_datapoint[i].d_recv_time += offset; ++ if (p->filter_datapoint[i].d_offset != 0) { ++ p->filter_datapoint[i].d_offset += offset; ++ } ++ } else { ++ p->filter_datapoint[i].d_recv_time = G.cur_time; ++ p->filter_datapoint[i].d_offset = 0; ++ p->filter_datapoint[i].d_dispersion = MAXDISP; ++ } ++ } ++ if (small_ofs) { ++ p->lastpkt_recv_time += offset; ++ } else { ++ p->reachable_bits = 0; ++ p->lastpkt_recv_time = G.cur_time; ++ } ++ filter_datapoints(p); /* recalc p->filter_xxx */ ++ VERB5 bb_error_msg("%s->lastpkt_recv_time=%f", p->p_dotted, p->lastpkt_recv_time); ++} ++ ++static void ++add_peers(char *s) ++{ ++ peer_t *p; ++ ++ p = xzalloc(sizeof(*p)); ++ p->p_lsa = xhost2sockaddr(s, 123); ++ p->p_dotted = xmalloc_sockaddr2dotted_noport(&p->p_lsa->u.sa); ++ p->p_fd = -1; ++ p->p_xmt_msg.m_status = MODE_CLIENT | (NTP_VERSION << 3); ++ p->next_action_time = G.cur_time; /* = set_next(p, 0); */ ++ reset_peer_stats(p, 16 * STEP_THRESHOLD); ++ ++ llist_add_to(&G.ntp_peers, p); ++ G.peer_cnt++; ++} ++ ++static int ++do_sendto(int fd, ++ const struct sockaddr *from, const struct sockaddr *to, socklen_t addrlen, ++ msg_t *msg, ssize_t len) ++{ ++ ssize_t ret; ++ ++ errno = 0; ++ if (!from) { ++ ret = sendto(fd, msg, len, MSG_DONTWAIT, to, addrlen); ++ } else { ++ ret = send_to_from(fd, msg, len, MSG_DONTWAIT, to, from, addrlen); ++ } ++ if (ret != len) { ++ bb_perror_msg("send failed"); ++ return -1; ++ } ++ return 0; ++} ++ ++static void ++send_query_to_peer(peer_t *p) ++{ ++ /* Why do we need to bind()? ++ * See what happens when we don't bind: ++ * ++ * socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 3 ++ * setsockopt(3, SOL_IP, IP_TOS, [16], 4) = 0 ++ * gettimeofday({1259071266, 327885}, NULL) = 0 ++ * sendto(3, "xxx", 48, MSG_DONTWAIT, {sa_family=AF_INET, sin_port=htons(123), sin_addr=inet_addr("10.34.32.125")}, 16) = 48 ++ * ^^^ we sent it from some source port picked by kernel. ++ * time(NULL) = 1259071266 ++ * write(2, "ntpd: entering poll 15 secs\n", 28) = 28 ++ * poll([{fd=3, events=POLLIN}], 1, 15000) = 1 ([{fd=3, revents=POLLIN}]) ++ * recv(3, "yyy", 68, MSG_DONTWAIT) = 48 ++ * ^^^ this recv will receive packets to any local port! ++ * ++ * Uncomment this and use strace to see it in action: ++ */ ++#define PROBE_LOCAL_ADDR /* { len_and_sockaddr lsa; lsa.len = LSA_SIZEOF_SA; getsockname(p->query.fd, &lsa.u.sa, &lsa.len); } */ ++ ++ if (p->p_fd == -1) { ++ int fd, family; ++ len_and_sockaddr *local_lsa; ++ ++ family = p->p_lsa->u.sa.sa_family; ++ p->p_fd = fd = xsocket_type(&local_lsa, family, SOCK_DGRAM); ++ /* local_lsa has "null" address and port 0 now. ++ * bind() ensures we have a *particular port* selected by kernel ++ * and remembered in p->p_fd, thus later recv(p->p_fd) ++ * receives only packets sent to this port. ++ */ ++ PROBE_LOCAL_ADDR ++ xbind(fd, &local_lsa->u.sa, local_lsa->len); ++ PROBE_LOCAL_ADDR ++#if ENABLE_FEATURE_IPV6 ++ if (family == AF_INET) ++#endif ++ setsockopt(fd, IPPROTO_IP, IP_TOS, &const_IPTOS_LOWDELAY, sizeof(const_IPTOS_LOWDELAY)); ++ free(local_lsa); ++ } ++ ++ /* ++ * Send out a random 64-bit number as our transmit time. The NTP ++ * server will copy said number into the originate field on the ++ * response that it sends us. This is totally legal per the SNTP spec. ++ * ++ * The impact of this is two fold: we no longer send out the current ++ * system time for the world to see (which may aid an attacker), and ++ * it gives us a (not very secure) way of knowing that we're not ++ * getting spoofed by an attacker that can't capture our traffic ++ * but can spoof packets from the NTP server we're communicating with. ++ * ++ * Save the real transmit timestamp locally. ++ */ ++ p->p_xmt_msg.m_xmttime.int_partl = random(); ++ p->p_xmt_msg.m_xmttime.fractionl = random(); ++ p->p_xmttime = gettime1900d(); ++ ++ if (do_sendto(p->p_fd, /*from:*/ NULL, /*to:*/ &p->p_lsa->u.sa, /*addrlen:*/ p->p_lsa->len, ++ &p->p_xmt_msg, NTP_MSGSIZE_NOAUTH) == -1 ++ ) { ++ close(p->p_fd); ++ p->p_fd = -1; ++ set_next(p, RETRY_INTERVAL); ++ return; ++ } ++ ++ p->reachable_bits <<= 1; ++ VERB1 bb_error_msg("sent query to %s", p->p_dotted); ++ set_next(p, RESPONSE_INTERVAL); ++} ++ ++ ++/* Note that there is no provision to prevent several run_scripts ++ * to be done in quick succession. In fact, it happens rather often ++ * if initial syncronization results in a step. ++ * You will see "step" and then "stratum" script runs, sometimes ++ * as close as only 0.002 seconds apart. ++ * Script should be ready to deal with this. ++ */ ++static void run_script(const char *action, double offset) ++{ ++ char *argv[3]; ++ char *env1, *env2, *env3, *env4; ++ ++ if (!G.script_name) ++ return; ++ ++ argv[0] = (char*) G.script_name; ++ argv[1] = (char*) action; ++ argv[2] = NULL; ++ ++ VERB1 bb_error_msg("executing '%s %s'", G.script_name, action); ++ ++ env1 = xasprintf("%s=%u", "stratum", G.stratum); ++ putenv(env1); ++ env2 = xasprintf("%s=%ld", "freq_drift_ppm", G.kernel_freq_drift); ++ putenv(env2); ++ env3 = xasprintf("%s=%u", "poll_interval", 1 << G.poll_exp); ++ putenv(env3); ++ env4 = xasprintf("%s=%f", "offset", offset); ++ putenv(env4); ++ /* Other items of potential interest: selected peer, ++ * rootdelay, reftime, rootdisp, refid, ntp_status, ++ * last_update_offset, last_update_recv_time, discipline_jitter, ++ * how many peers have reachable_bits = 0? ++ */ ++ ++ /* Don't want to wait: it may run hwclock --systohc, and that ++ * may take some time (seconds): */ ++ /*spawn_and_wait(argv);*/ ++ spawn(argv); ++ ++ unsetenv("stratum"); ++ unsetenv("freq_drift_ppm"); ++ unsetenv("poll_interval"); ++ unsetenv("offset"); ++ free(env1); ++ free(env2); ++ free(env3); ++ free(env4); ++ ++ G.last_script_run = G.cur_time; ++} ++ ++static NOINLINE void ++step_time(double offset) ++{ ++ llist_t *item; ++ double dtime; ++ struct timeval tv; ++ char buf[80]; ++ time_t tval; ++ ++ gettimeofday(&tv, NULL); /* never fails */ ++ dtime = offset + tv.tv_sec; ++ dtime += 1.0e-6 * tv.tv_usec; ++ d_to_tv(dtime, &tv); ++ ++ if (settimeofday(&tv, NULL) == -1) ++ bb_perror_msg_and_die("settimeofday"); ++ ++ tval = tv.tv_sec; ++ strftime(buf, sizeof(buf), "%a %b %e %H:%M:%S %Z %Y", localtime(&tval)); ++ ++ bb_error_msg("setting clock to %s (offset %fs)", buf, offset); ++ ++ /* Correct various fields which contain time-relative values: */ ++ ++ /* p->lastpkt_recv_time, p->next_action_time and such: */ ++ for (item = G.ntp_peers; item != NULL; item = item->link) { ++ peer_t *pp = (peer_t *) item->data; ++ reset_peer_stats(pp, offset); ++ //bb_error_msg("offset:%f pp->next_action_time:%f -> %f", ++ // offset, pp->next_action_time, pp->next_action_time + offset); ++ pp->next_action_time += offset; ++ } ++ /* Globals: */ ++ G.cur_time += offset; ++ G.last_update_recv_time += offset; ++ G.last_script_run += offset; ++} ++ ++ ++/* ++ * Selection and clustering, and their helpers ++ */ ++typedef struct { ++ peer_t *p; ++ int type; ++ double edge; ++ double opt_rd; /* optimization */ ++} point_t; ++static int ++compare_point_edge(const void *aa, const void *bb) ++{ ++ const point_t *a = aa; ++ const point_t *b = bb; ++ if (a->edge < b->edge) { ++ return -1; ++ } ++ return (a->edge > b->edge); ++} ++typedef struct { ++ peer_t *p; ++ double metric; ++} survivor_t; ++static int ++compare_survivor_metric(const void *aa, const void *bb) ++{ ++ const survivor_t *a = aa; ++ const survivor_t *b = bb; ++ if (a->metric < b->metric) { ++ return -1; ++ } ++ return (a->metric > b->metric); ++} ++static int ++fit(peer_t *p, double rd) ++{ ++ if ((p->reachable_bits & (p->reachable_bits-1)) == 0) { ++ /* One or zero bits in reachable_bits */ ++ VERB3 bb_error_msg("peer %s unfit for selection: unreachable", p->p_dotted); ++ return 0; ++ } ++#if 0 /* we filter out such packets earlier */ ++ if ((p->lastpkt_status & LI_ALARM) == LI_ALARM ++ || p->lastpkt_stratum >= MAXSTRAT ++ ) { ++ VERB3 bb_error_msg("peer %s unfit for selection: bad status/stratum", p->p_dotted); ++ return 0; ++ } ++#endif ++ /* rd is root_distance(p) */ ++ if (rd > MAXDIST + FREQ_TOLERANCE * (1 << G.poll_exp)) { ++ VERB3 bb_error_msg("peer %s unfit for selection: root distance too high", p->p_dotted); ++ return 0; ++ } ++//TODO ++// /* Do we have a loop? */ ++// if (p->refid == p->dstaddr || p->refid == s.refid) ++// return 0; ++ return 1; ++} ++static peer_t* ++select_and_cluster(void) ++{ ++ peer_t *p; ++ llist_t *item; ++ int i, j; ++ int size = 3 * G.peer_cnt; ++ /* for selection algorithm */ ++ point_t point[size]; ++ unsigned num_points, num_candidates; ++ double low, high; ++ unsigned num_falsetickers; ++ /* for cluster algorithm */ ++ survivor_t survivor[size]; ++ unsigned num_survivors; ++ ++ /* Selection */ ++ ++ num_points = 0; ++ item = G.ntp_peers; ++ if (G.initial_poll_complete) while (item != NULL) { ++ double rd, offset; ++ ++ p = (peer_t *) item->data; ++ rd = root_distance(p); ++ offset = p->filter_offset; ++ if (!fit(p, rd)) { ++ item = item->link; ++ continue; ++ } ++ ++ VERB4 bb_error_msg("interval: [%f %f %f] %s", ++ offset - rd, ++ offset, ++ offset + rd, ++ p->p_dotted ++ ); ++ point[num_points].p = p; ++ point[num_points].type = -1; ++ point[num_points].edge = offset - rd; ++ point[num_points].opt_rd = rd; ++ num_points++; ++ point[num_points].p = p; ++ point[num_points].type = 0; ++ point[num_points].edge = offset; ++ point[num_points].opt_rd = rd; ++ num_points++; ++ point[num_points].p = p; ++ point[num_points].type = 1; ++ point[num_points].edge = offset + rd; ++ point[num_points].opt_rd = rd; ++ num_points++; ++ item = item->link; ++ } ++ num_candidates = num_points / 3; ++ if (num_candidates == 0) { ++ VERB3 bb_error_msg("no valid datapoints, no peer selected"); ++ return NULL; ++ } ++//TODO: sorting does not seem to be done in reference code ++ qsort(point, num_points, sizeof(point[0]), compare_point_edge); ++ ++ /* Start with the assumption that there are no falsetickers. ++ * Attempt to find a nonempty intersection interval containing ++ * the midpoints of all truechimers. ++ * If a nonempty interval cannot be found, increase the number ++ * of assumed falsetickers by one and try again. ++ * If a nonempty interval is found and the number of falsetickers ++ * is less than the number of truechimers, a majority has been found ++ * and the midpoint of each truechimer represents ++ * the candidates available to the cluster algorithm. ++ */ ++ num_falsetickers = 0; ++ while (1) { ++ int c; ++ unsigned num_midpoints = 0; ++ ++ low = 1 << 9; ++ high = - (1 << 9); ++ c = 0; ++ for (i = 0; i < num_points; i++) { ++ /* We want to do: ++ * if (point[i].type == -1) c++; ++ * if (point[i].type == 1) c--; ++ * and it's simpler to do it this way: ++ */ ++ c -= point[i].type; ++ if (c >= num_candidates - num_falsetickers) { ++ /* If it was c++ and it got big enough... */ ++ low = point[i].edge; ++ break; ++ } ++ if (point[i].type == 0) ++ num_midpoints++; ++ } ++ c = 0; ++ for (i = num_points-1; i >= 0; i--) { ++ c += point[i].type; ++ if (c >= num_candidates - num_falsetickers) { ++ high = point[i].edge; ++ break; ++ } ++ if (point[i].type == 0) ++ num_midpoints++; ++ } ++ /* If the number of midpoints is greater than the number ++ * of allowed falsetickers, the intersection contains at ++ * least one truechimer with no midpoint - bad. ++ * Also, interval should be nonempty. ++ */ ++ if (num_midpoints <= num_falsetickers && low < high) ++ break; ++ num_falsetickers++; ++ if (num_falsetickers * 2 >= num_candidates) { ++ VERB3 bb_error_msg("too many falsetickers:%d (candidates:%d), no peer selected", ++ num_falsetickers, num_candidates); ++ return NULL; ++ } ++ } ++ VERB3 bb_error_msg("selected interval: [%f, %f]; candidates:%d falsetickers:%d", ++ low, high, num_candidates, num_falsetickers); ++ ++ /* Clustering */ ++ ++ /* Construct a list of survivors (p, metric) ++ * from the chime list, where metric is dominated ++ * first by stratum and then by root distance. ++ * All other things being equal, this is the order of preference. ++ */ ++ num_survivors = 0; ++ for (i = 0; i < num_points; i++) { ++ if (point[i].edge < low || point[i].edge > high) ++ continue; ++ p = point[i].p; ++ survivor[num_survivors].p = p; ++ /* x.opt_rd == root_distance(p); */ ++ survivor[num_survivors].metric = MAXDIST * p->lastpkt_stratum + point[i].opt_rd; ++ VERB4 bb_error_msg("survivor[%d] metric:%f peer:%s", ++ num_survivors, survivor[num_survivors].metric, p->p_dotted); ++ num_survivors++; ++ } ++ /* There must be at least MIN_SELECTED survivors to satisfy the ++ * correctness assertions. Ordinarily, the Byzantine criteria ++ * require four survivors, but for the demonstration here, one ++ * is acceptable. ++ */ ++ if (num_survivors < MIN_SELECTED) { ++ VERB3 bb_error_msg("num_survivors %d < %d, no peer selected", ++ num_survivors, MIN_SELECTED); ++ return NULL; ++ } ++ ++//looks like this is ONLY used by the fact that later we pick survivor[0]. ++//we can avoid sorting then, just find the minimum once! ++ qsort(survivor, num_survivors, sizeof(survivor[0]), compare_survivor_metric); ++ ++ /* For each association p in turn, calculate the selection ++ * jitter p->sjitter as the square root of the sum of squares ++ * (p->offset - q->offset) over all q associations. The idea is ++ * to repeatedly discard the survivor with maximum selection ++ * jitter until a termination condition is met. ++ */ ++ while (1) { ++ unsigned max_idx = max_idx; ++ double max_selection_jitter = max_selection_jitter; ++ double min_jitter = min_jitter; ++ ++ if (num_survivors <= MIN_CLUSTERED) { ++ VERB3 bb_error_msg("num_survivors %d <= %d, not discarding more", ++ num_survivors, MIN_CLUSTERED); ++ break; ++ } ++ ++ /* To make sure a few survivors are left ++ * for the clustering algorithm to chew on, ++ * we stop if the number of survivors ++ * is less than or equal to MIN_CLUSTERED (3). ++ */ ++ for (i = 0; i < num_survivors; i++) { ++ double selection_jitter_sq; ++ ++ p = survivor[i].p; ++ if (i == 0 || p->filter_jitter < min_jitter) ++ min_jitter = p->filter_jitter; ++ ++ selection_jitter_sq = 0; ++ for (j = 0; j < num_survivors; j++) { ++ peer_t *q = survivor[j].p; ++ selection_jitter_sq += SQUARE(p->filter_offset - q->filter_offset); ++ } ++ if (i == 0 || selection_jitter_sq > max_selection_jitter) { ++ max_selection_jitter = selection_jitter_sq; ++ max_idx = i; ++ } ++ VERB5 bb_error_msg("survivor %d selection_jitter^2:%f", ++ i, selection_jitter_sq); ++ } ++ max_selection_jitter = SQRT(max_selection_jitter / num_survivors); ++ VERB4 bb_error_msg("max_selection_jitter (at %d):%f min_jitter:%f", ++ max_idx, max_selection_jitter, min_jitter); ++ ++ /* If the maximum selection jitter is less than the ++ * minimum peer jitter, then tossing out more survivors ++ * will not lower the minimum peer jitter, so we might ++ * as well stop. ++ */ ++ if (max_selection_jitter < min_jitter) { ++ VERB3 bb_error_msg("max_selection_jitter:%f < min_jitter:%f, num_survivors:%d, not discarding more", ++ max_selection_jitter, min_jitter, num_survivors); ++ break; ++ } ++ ++ /* Delete survivor[max_idx] from the list ++ * and go around again. ++ */ ++ VERB5 bb_error_msg("dropping survivor %d", max_idx); ++ num_survivors--; ++ while (max_idx < num_survivors) { ++ survivor[max_idx] = survivor[max_idx + 1]; ++ max_idx++; ++ } ++ } ++ ++ if (0) { ++ /* Combine the offsets of the clustering algorithm survivors ++ * using a weighted average with weight determined by the root ++ * distance. Compute the selection jitter as the weighted RMS ++ * difference between the first survivor and the remaining ++ * survivors. In some cases the inherent clock jitter can be ++ * reduced by not using this algorithm, especially when frequent ++ * clockhopping is involved. bbox: thus we don't do it. ++ */ ++ double x, y, z, w; ++ y = z = w = 0; ++ for (i = 0; i < num_survivors; i++) { ++ p = survivor[i].p; ++ x = root_distance(p); ++ y += 1 / x; ++ z += p->filter_offset / x; ++ w += SQUARE(p->filter_offset - survivor[0].p->filter_offset) / x; ++ } ++ //G.cluster_offset = z / y; ++ //G.cluster_jitter = SQRT(w / y); ++ } ++ ++ /* Pick the best clock. If the old system peer is on the list ++ * and at the same stratum as the first survivor on the list, ++ * then don't do a clock hop. Otherwise, select the first ++ * survivor on the list as the new system peer. ++ */ ++ p = survivor[0].p; ++ if (G.last_update_peer ++ && G.last_update_peer->lastpkt_stratum <= p->lastpkt_stratum ++ ) { ++ /* Starting from 1 is ok here */ ++ for (i = 1; i < num_survivors; i++) { ++ if (G.last_update_peer == survivor[i].p) { ++ VERB4 bb_error_msg("keeping old synced peer"); ++ p = G.last_update_peer; ++ goto keep_old; ++ } ++ } ++ } ++ G.last_update_peer = p; ++ keep_old: ++ VERB3 bb_error_msg("selected peer %s filter_offset:%f age:%f", ++ p->p_dotted, ++ p->filter_offset, ++ G.cur_time - p->lastpkt_recv_time ++ ); ++ return p; ++} ++ ++ ++/* ++ * Local clock discipline and its helpers ++ */ ++static void ++set_new_values(int disc_state, double offset, double recv_time) ++{ ++ /* Enter new state and set state variables. Note we use the time ++ * of the last clock filter sample, which must be earlier than ++ * the current time. ++ */ ++ VERB3 bb_error_msg("disc_state=%d last update offset=%f recv_time=%f", ++ disc_state, offset, recv_time); ++ G.discipline_state = disc_state; ++ G.last_update_offset = offset; ++ G.last_update_recv_time = recv_time; ++} ++/* Return: -1: decrease poll interval, 0: leave as is, 1: increase */ ++static NOINLINE int ++update_local_clock(peer_t *p) ++{ ++ int rc; ++ struct timex tmx; ++ /* Note: can use G.cluster_offset instead: */ ++ double offset = p->filter_offset; ++ double recv_time = p->lastpkt_recv_time; ++ double abs_offset; ++#if !USING_KERNEL_PLL_LOOP ++ double freq_drift; ++#endif ++ double since_last_update; ++ double etemp, dtemp; ++ ++ abs_offset = fabs(offset); ++ ++#if 0 ++ /* If needed, -S script can do it by looking at $offset ++ * env var and killing parent */ ++ /* If the offset is too large, give up and go home */ ++ if (abs_offset > PANIC_THRESHOLD) { ++ bb_error_msg_and_die("offset %f far too big, exiting", offset); ++ } ++#endif ++ ++ /* If this is an old update, for instance as the result ++ * of a system peer change, avoid it. We never use ++ * an old sample or the same sample twice. ++ */ ++ if (recv_time <= G.last_update_recv_time) { ++ VERB3 bb_error_msg("same or older datapoint: %f >= %f, not using it", ++ G.last_update_recv_time, recv_time); ++ return 0; /* "leave poll interval as is" */ ++ } ++ ++ /* Clock state machine transition function. This is where the ++ * action is and defines how the system reacts to large time ++ * and frequency errors. ++ */ ++ since_last_update = recv_time - G.reftime; ++#if !USING_KERNEL_PLL_LOOP ++ freq_drift = 0; ++#endif ++#if USING_INITIAL_FREQ_ESTIMATION ++ if (G.discipline_state == STATE_FREQ) { ++ /* Ignore updates until the stepout threshold */ ++ if (since_last_update < WATCH_THRESHOLD) { ++ VERB3 bb_error_msg("measuring drift, datapoint ignored, %f sec remains", ++ WATCH_THRESHOLD - since_last_update); ++ return 0; /* "leave poll interval as is" */ ++ } ++# if !USING_KERNEL_PLL_LOOP ++ freq_drift = (offset - G.last_update_offset) / since_last_update; ++# endif ++ } ++#endif ++ ++ /* There are two main regimes: when the ++ * offset exceeds the step threshold and when it does not. ++ */ ++ if (abs_offset > STEP_THRESHOLD) { ++ switch (G.discipline_state) { ++ case STATE_SYNC: ++ /* The first outlyer: ignore it, switch to SPIK state */ ++ VERB3 bb_error_msg("offset:%f - spike detected", offset); ++ G.discipline_state = STATE_SPIK; ++ return -1; /* "decrease poll interval" */ ++ ++ case STATE_SPIK: ++ /* Ignore succeeding outlyers until either an inlyer ++ * is found or the stepout threshold is exceeded. ++ */ ++ if (since_last_update < WATCH_THRESHOLD) { ++ VERB3 bb_error_msg("spike detected, datapoint ignored, %f sec remains", ++ WATCH_THRESHOLD - since_last_update); ++ return -1; /* "decrease poll interval" */ ++ } ++ /* fall through: we need to step */ ++ } /* switch */ ++ ++ /* Step the time and clamp down the poll interval. ++ * ++ * In NSET state an initial frequency correction is ++ * not available, usually because the frequency file has ++ * not yet been written. Since the time is outside the ++ * capture range, the clock is stepped. The frequency ++ * will be set directly following the stepout interval. ++ * ++ * In FSET state the initial frequency has been set ++ * from the frequency file. Since the time is outside ++ * the capture range, the clock is stepped immediately, ++ * rather than after the stepout interval. Guys get ++ * nervous if it takes 17 minutes to set the clock for ++ * the first time. ++ * ++ * In SPIK state the stepout threshold has expired and ++ * the phase is still above the step threshold. Note ++ * that a single spike greater than the step threshold ++ * is always suppressed, even at the longer poll ++ * intervals. ++ */ ++ VERB3 bb_error_msg("stepping time by %f; poll_exp=MINPOLL", offset); ++ step_time(offset); ++ if (option_mask32 & OPT_q) { ++ /* We were only asked to set time once. Done. */ ++ exit(0); ++ } ++ ++ G.polladj_count = 0; ++ G.poll_exp = MINPOLL; ++ G.stratum = MAXSTRAT; ++ ++ run_script("step", offset); ++ ++#if USING_INITIAL_FREQ_ESTIMATION ++ if (G.discipline_state == STATE_NSET) { ++ set_new_values(STATE_FREQ, /*offset:*/ 0, recv_time); ++ return 1; /* "ok to increase poll interval" */ ++ } ++#endif ++ set_new_values(STATE_SYNC, /*offset:*/ 0, recv_time); ++ ++ } else { /* abs_offset <= STEP_THRESHOLD */ ++ ++ if (G.poll_exp < MINPOLL && G.initial_poll_complete) { ++ VERB3 bb_error_msg("small offset:%f, disabling burst mode", offset); ++ G.polladj_count = 0; ++ G.poll_exp = MINPOLL; ++ } ++ ++ /* Compute the clock jitter as the RMS of exponentially ++ * weighted offset differences. Used by the poll adjust code. ++ */ ++ etemp = SQUARE(G.discipline_jitter); ++ dtemp = SQUARE(MAXD(fabs(offset - G.last_update_offset), G_precision_sec)); ++ G.discipline_jitter = SQRT(etemp + (dtemp - etemp) / AVG); ++ VERB3 bb_error_msg("discipline jitter=%f", G.discipline_jitter); ++ ++ switch (G.discipline_state) { ++ case STATE_NSET: ++ if (option_mask32 & OPT_q) { ++ /* We were only asked to set time once. ++ * The clock is precise enough, no need to step. ++ */ ++ exit(0); ++ } ++#if USING_INITIAL_FREQ_ESTIMATION ++ /* This is the first update received and the frequency ++ * has not been initialized. The first thing to do ++ * is directly measure the oscillator frequency. ++ */ ++ set_new_values(STATE_FREQ, offset, recv_time); ++#else ++ set_new_values(STATE_SYNC, offset, recv_time); ++#endif ++ VERB3 bb_error_msg("transitioning to FREQ, datapoint ignored"); ++ return 0; /* "leave poll interval as is" */ ++ ++#if 0 /* this is dead code for now */ ++ case STATE_FSET: ++ /* This is the first update and the frequency ++ * has been initialized. Adjust the phase, but ++ * don't adjust the frequency until the next update. ++ */ ++ set_new_values(STATE_SYNC, offset, recv_time); ++ /* freq_drift remains 0 */ ++ break; ++#endif ++ ++#if USING_INITIAL_FREQ_ESTIMATION ++ case STATE_FREQ: ++ /* since_last_update >= WATCH_THRESHOLD, we waited enough. ++ * Correct the phase and frequency and switch to SYNC state. ++ * freq_drift was already estimated (see code above) ++ */ ++ set_new_values(STATE_SYNC, offset, recv_time); ++ break; ++#endif ++ ++ default: ++#if !USING_KERNEL_PLL_LOOP ++ /* Compute freq_drift due to PLL and FLL contributions. ++ * ++ * The FLL and PLL frequency gain constants ++ * depend on the poll interval and Allan ++ * intercept. The FLL is not used below one-half ++ * the Allan intercept. Above that the loop gain ++ * increases in steps to 1 / AVG. ++ */ ++ if ((1 << G.poll_exp) > ALLAN / 2) { ++ etemp = FLL - G.poll_exp; ++ if (etemp < AVG) ++ etemp = AVG; ++ freq_drift += (offset - G.last_update_offset) / (MAXD(since_last_update, ALLAN) * etemp); ++ } ++ /* For the PLL the integration interval ++ * (numerator) is the minimum of the update ++ * interval and poll interval. This allows ++ * oversampling, but not undersampling. ++ */ ++ etemp = MIND(since_last_update, (1 << G.poll_exp)); ++ dtemp = (4 * PLL) << G.poll_exp; ++ freq_drift += offset * etemp / SQUARE(dtemp); ++#endif ++ set_new_values(STATE_SYNC, offset, recv_time); ++ break; ++ } ++ if (G.stratum != p->lastpkt_stratum + 1) { ++ G.stratum = p->lastpkt_stratum + 1; ++ run_script("stratum", offset); ++ } ++ } ++ ++ G.reftime = G.cur_time; ++ G.ntp_status = p->lastpkt_status; ++ G.refid = p->lastpkt_refid; ++ G.rootdelay = p->lastpkt_rootdelay + p->lastpkt_delay; ++ dtemp = p->filter_jitter; // SQRT(SQUARE(p->filter_jitter) + SQUARE(G.cluster_jitter)); ++ dtemp += MAXD(p->filter_dispersion + FREQ_TOLERANCE * (G.cur_time - p->lastpkt_recv_time) + abs_offset, MINDISP); ++ G.rootdisp = p->lastpkt_rootdisp + dtemp; ++ VERB3 bb_error_msg("updating leap/refid/reftime/rootdisp from peer %s", p->p_dotted); ++ ++ /* We are in STATE_SYNC now, but did not do adjtimex yet. ++ * (Any other state does not reach this, they all return earlier) ++ * By this time, freq_drift and G.last_update_offset are set ++ * to values suitable for adjtimex. ++ */ ++#if !USING_KERNEL_PLL_LOOP ++ /* Calculate the new frequency drift and frequency stability (wander). ++ * Compute the clock wander as the RMS of exponentially weighted ++ * frequency differences. This is not used directly, but can, ++ * along with the jitter, be a highly useful monitoring and ++ * debugging tool. ++ */ ++ dtemp = G.discipline_freq_drift + freq_drift; ++ G.discipline_freq_drift = MAXD(MIND(MAXDRIFT, dtemp), -MAXDRIFT); ++ etemp = SQUARE(G.discipline_wander); ++ dtemp = SQUARE(dtemp); ++ G.discipline_wander = SQRT(etemp + (dtemp - etemp) / AVG); ++ ++ VERB3 bb_error_msg("discipline freq_drift=%.9f(int:%ld corr:%e) wander=%f", ++ G.discipline_freq_drift, ++ (long)(G.discipline_freq_drift * 65536e6), ++ freq_drift, ++ G.discipline_wander); ++#endif ++ VERB3 { ++ memset(&tmx, 0, sizeof(tmx)); ++ if (adjtimex(&tmx) < 0) ++ bb_perror_msg_and_die("adjtimex"); ++ VERB3 bb_error_msg("p adjtimex freq:%ld offset:%ld constant:%ld status:0x%x", ++ tmx.freq, tmx.offset, tmx.constant, tmx.status); ++ } ++ ++ memset(&tmx, 0, sizeof(tmx)); ++#if 0 ++//doesn't work, offset remains 0 (!) in kernel: ++//ntpd: set adjtimex freq:1786097 tmx.offset:77487 ++//ntpd: prev adjtimex freq:1786097 tmx.offset:0 ++//ntpd: cur adjtimex freq:1786097 tmx.offset:0 ++ tmx.modes = ADJ_FREQUENCY | ADJ_OFFSET; ++ /* 65536 is one ppm */ ++ tmx.freq = G.discipline_freq_drift * 65536e6; ++ tmx.offset = G.last_update_offset * 1000000; /* usec */ ++#endif ++ tmx.modes = ADJ_OFFSET | ADJ_STATUS | ADJ_TIMECONST;// | ADJ_MAXERROR | ADJ_ESTERROR; ++ tmx.offset = (G.last_update_offset * 1000000); /* usec */ ++ /* + (G.last_update_offset < 0 ? -0.5 : 0.5) - too small to bother */ ++ tmx.status = STA_PLL; ++ if (G.ntp_status & LI_PLUSSEC) ++ tmx.status |= STA_INS; ++ if (G.ntp_status & LI_MINUSSEC) ++ tmx.status |= STA_DEL; ++ tmx.constant = G.poll_exp - 4; ++ //tmx.esterror = (u_int32)(clock_jitter * 1e6); ++ //tmx.maxerror = (u_int32)((sys_rootdelay / 2 + sys_rootdisp) * 1e6); ++ rc = adjtimex(&tmx); ++ if (rc < 0) ++ bb_perror_msg_and_die("adjtimex"); ++ /* NB: here kernel returns constant == G.poll_exp, not == G.poll_exp - 4. ++ * Not sure why. Perhaps it is normal. ++ */ ++ VERB3 bb_error_msg("adjtimex:%d freq:%ld offset:%ld constant:%ld status:0x%x", ++ rc, tmx.freq, tmx.offset, tmx.constant, tmx.status); ++#if 0 ++ VERB3 { ++ /* always gives the same output as above msg */ ++ memset(&tmx, 0, sizeof(tmx)); ++ if (adjtimex(&tmx) < 0) ++ bb_perror_msg_and_die("adjtimex"); ++ VERB3 bb_error_msg("c adjtimex freq:%ld offset:%ld constant:%ld status:0x%x", ++ tmx.freq, tmx.offset, tmx.constant, tmx.status); ++ } ++#endif ++ G.kernel_freq_drift = tmx.freq / 65536; ++ VERB2 bb_error_msg("update peer:%s, offset:%f, clock drift:%ld ppm", ++ p->p_dotted, G.last_update_offset, G.kernel_freq_drift); ++ ++ return 1; /* "ok to increase poll interval" */ ++} ++ ++ ++/* ++ * We've got a new reply packet from a peer, process it ++ * (helpers first) ++ */ ++static unsigned ++retry_interval(void) ++{ ++ /* Local problem, want to retry soon */ ++ unsigned interval, r; ++ interval = RETRY_INTERVAL; ++ r = random(); ++ interval += r % (unsigned)(RETRY_INTERVAL / 4); ++ VERB3 bb_error_msg("chose retry interval:%u", interval); ++ return interval; ++} ++static unsigned ++poll_interval(int exponent) ++{ ++ unsigned interval, r; ++ exponent = G.poll_exp + exponent; ++ if (exponent < 0) ++ exponent = 0; ++ interval = 1 << exponent; ++ r = random(); ++ interval += ((r & (interval-1)) >> 4) + ((r >> 8) & 1); /* + 1/16 of interval, max */ ++ VERB3 bb_error_msg("chose poll interval:%u (poll_exp:%d exp:%d)", interval, G.poll_exp, exponent); ++ return interval; ++} ++static NOINLINE void ++recv_and_process_peer_pkt(peer_t *p) ++{ ++ int rc; ++ ssize_t size; ++ msg_t msg; ++ double T1, T2, T3, T4; ++ unsigned interval; ++ datapoint_t *datapoint; ++ peer_t *q; ++ ++ /* We can recvfrom here and check from.IP, but some multihomed ++ * ntp servers reply from their *other IP*. ++ * TODO: maybe we should check at least what we can: from.port == 123? ++ */ ++ size = recv(p->p_fd, &msg, sizeof(msg), MSG_DONTWAIT); ++ if (size == -1) { ++ bb_perror_msg("recv(%s) error", p->p_dotted); ++ if (errno == EHOSTUNREACH || errno == EHOSTDOWN ++ || errno == ENETUNREACH || errno == ENETDOWN ++ || errno == ECONNREFUSED || errno == EADDRNOTAVAIL ++ || errno == EAGAIN ++ ) { ++//TODO: always do this? ++ interval = retry_interval(); ++ goto set_next_and_close_sock; ++ } ++ xfunc_die(); ++ } ++ ++ if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE) { ++ bb_error_msg("malformed packet received from %s", p->p_dotted); ++ goto bail; ++ } ++ ++ if (msg.m_orgtime.int_partl != p->p_xmt_msg.m_xmttime.int_partl ++ || msg.m_orgtime.fractionl != p->p_xmt_msg.m_xmttime.fractionl ++ ) { ++ goto bail; ++ } ++ ++ if ((msg.m_status & LI_ALARM) == LI_ALARM ++ || msg.m_stratum == 0 ++ || msg.m_stratum > NTP_MAXSTRATUM ++ ) { ++// TODO: stratum 0 responses may have commands in 32-bit m_refid field: ++// "DENY", "RSTR" - peer does not like us at all ++// "RATE" - peer is overloaded, reduce polling freq ++ interval = poll_interval(0); ++ bb_error_msg("reply from %s: not synced, next query in %us", p->p_dotted, interval); ++ goto set_next_and_close_sock; ++ } ++ ++// /* Verify valid root distance */ ++// if (msg.m_rootdelay / 2 + msg.m_rootdisp >= MAXDISP || p->lastpkt_reftime > msg.m_xmt) ++// return; /* invalid header values */ ++ ++ p->lastpkt_status = msg.m_status; ++ p->lastpkt_stratum = msg.m_stratum; ++ p->lastpkt_rootdelay = sfp_to_d(msg.m_rootdelay); ++ p->lastpkt_rootdisp = sfp_to_d(msg.m_rootdisp); ++ p->lastpkt_refid = msg.m_refid; ++ ++ /* ++ * From RFC 2030 (with a correction to the delay math): ++ * ++ * Timestamp Name ID When Generated ++ * ------------------------------------------------------------ ++ * Originate Timestamp T1 time request sent by client ++ * Receive Timestamp T2 time request received by server ++ * Transmit Timestamp T3 time reply sent by server ++ * Destination Timestamp T4 time reply received by client ++ * ++ * The roundtrip delay and local clock offset are defined as ++ * ++ * delay = (T4 - T1) - (T3 - T2); offset = ((T2 - T1) + (T3 - T4)) / 2 ++ */ ++ T1 = p->p_xmttime; ++ T2 = lfp_to_d(msg.m_rectime); ++ T3 = lfp_to_d(msg.m_xmttime); ++ T4 = G.cur_time; ++ ++ p->lastpkt_recv_time = T4; ++ ++ VERB5 bb_error_msg("%s->lastpkt_recv_time=%f", p->p_dotted, p->lastpkt_recv_time); ++ p->datapoint_idx = p->reachable_bits ? (p->datapoint_idx + 1) % NUM_DATAPOINTS : 0; ++ datapoint = &p->filter_datapoint[p->datapoint_idx]; ++ datapoint->d_recv_time = T4; ++ datapoint->d_offset = ((T2 - T1) + (T3 - T4)) / 2; ++ /* The delay calculation is a special case. In cases where the ++ * server and client clocks are running at different rates and ++ * with very fast networks, the delay can appear negative. In ++ * order to avoid violating the Principle of Least Astonishment, ++ * the delay is clamped not less than the system precision. ++ */ ++ p->lastpkt_delay = (T4 - T1) - (T3 - T2); ++ if (p->lastpkt_delay < G_precision_sec) ++ p->lastpkt_delay = G_precision_sec; ++ datapoint->d_dispersion = LOG2D(msg.m_precision_exp) + G_precision_sec; ++ if (!p->reachable_bits) { ++ /* 1st datapoint ever - replicate offset in every element */ ++ int i; ++ for (i = 1; i < NUM_DATAPOINTS; i++) { ++ p->filter_datapoint[i].d_offset = datapoint->d_offset; ++ } ++ } ++ ++ p->reachable_bits |= 1; ++ if ((MAX_VERBOSE && G.verbose) || (option_mask32 & OPT_w)) { ++ bb_error_msg("reply from %s: reach 0x%02x offset %f delay %f status 0x%02x strat %d refid 0x%08x rootdelay %f", ++ p->p_dotted, ++ p->reachable_bits, ++ datapoint->d_offset, ++ p->lastpkt_delay, ++ p->lastpkt_status, ++ p->lastpkt_stratum, ++ p->lastpkt_refid, ++ p->lastpkt_rootdelay ++ /* not shown: m_ppoll, m_precision_exp, m_rootdisp, ++ * m_reftime, m_orgtime, m_rectime, m_xmttime ++ */ ++ ); ++ } ++ ++ /* Muck with statictics and update the clock */ ++ filter_datapoints(p); ++ q = select_and_cluster(); ++ rc = -1; ++ if (q) { ++ rc = 0; ++ if (!(option_mask32 & OPT_w)) { ++ rc = update_local_clock(q); ++ /* If drift is dangerously large, immediately ++ * drop poll interval one step down. ++ */ ++ if (fabs(q->filter_offset) >= POLLDOWN_OFFSET) { ++ VERB3 bb_error_msg("offset:%f > POLLDOWN_OFFSET", q->filter_offset); ++ goto poll_down; ++ } ++ } ++ } ++ /* else: no peer selected, rc = -1: we want to poll more often */ ++ ++ if (rc != 0) { ++ /* Adjust the poll interval by comparing the current offset ++ * with the clock jitter. If the offset is less than ++ * the clock jitter times a constant, then the averaging interval ++ * is increased, otherwise it is decreased. A bit of hysteresis ++ * helps calm the dance. Works best using burst mode. ++ */ ++ VERB4 if (rc > 0) { ++ bb_error_msg("offset:%f POLLADJ_GATE*discipline_jitter:%f poll:%s", ++ q->filter_offset, POLLADJ_GATE * G.discipline_jitter, ++ fabs(q->filter_offset) < POLLADJ_GATE * G.discipline_jitter ++ ? "grows" : "falls" ++ ); ++ } ++ if (rc > 0 && fabs(q->filter_offset) < POLLADJ_GATE * G.discipline_jitter) { ++ /* was += G.poll_exp but it is a bit ++ * too optimistic for my taste at high poll_exp's */ ++ G.polladj_count += MINPOLL; ++ if (G.polladj_count > POLLADJ_LIMIT) { ++ G.polladj_count = 0; ++ if (G.poll_exp < MAXPOLL) { ++ G.poll_exp++; ++ VERB3 bb_error_msg("polladj: discipline_jitter:%f ++poll_exp=%d", ++ G.discipline_jitter, G.poll_exp); ++ } ++ } else { ++ VERB3 bb_error_msg("polladj: incr:%d", G.polladj_count); ++ } ++ } else { ++ G.polladj_count -= G.poll_exp * 2; ++ if (G.polladj_count < -POLLADJ_LIMIT || G.poll_exp >= BIGPOLL) { ++ poll_down: ++ G.polladj_count = 0; ++ if (G.poll_exp > MINPOLL) { ++ llist_t *item; ++ ++ G.poll_exp--; ++ /* Correct p->next_action_time in each peer ++ * which waits for sending, so that they send earlier. ++ * Old pp->next_action_time are on the order ++ * of t + (1 << old_poll_exp) + small_random, ++ * we simply need to subtract ~half of that. ++ */ ++ for (item = G.ntp_peers; item != NULL; item = item->link) { ++ peer_t *pp = (peer_t *) item->data; ++ if (pp->p_fd < 0) ++ pp->next_action_time -= (1 << G.poll_exp); ++ } ++ VERB3 bb_error_msg("polladj: discipline_jitter:%f --poll_exp=%d", ++ G.discipline_jitter, G.poll_exp); ++ } ++ } else { ++ VERB3 bb_error_msg("polladj: decr:%d", G.polladj_count); ++ } ++ } ++ } ++ ++ /* Decide when to send new query for this peer */ ++ interval = poll_interval(0); ++ ++ set_next_and_close_sock: ++ set_next(p, interval); ++ /* We do not expect any more packets from this peer for now. ++ * Closing the socket informs kernel about it. ++ * We open a new socket when we send a new query. ++ */ ++ close(p->p_fd); ++ p->p_fd = -1; ++ bail: ++ return; ++} ++ ++#if ENABLE_FEATURE_NTPD_SERVER ++static NOINLINE void ++recv_and_process_client_pkt(void /*int fd*/) ++{ ++ ssize_t size; ++ uint8_t version; ++ len_and_sockaddr *to; ++ struct sockaddr *from; ++ msg_t msg; ++ uint8_t query_status; ++ l_fixedpt_t query_xmttime; ++ ++ to = get_sock_lsa(G.listen_fd); ++ from = xzalloc(to->len); ++ ++ size = recv_from_to(G.listen_fd, &msg, sizeof(msg), MSG_DONTWAIT, from, &to->u.sa, to->len); ++ if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE) { ++ char *addr; ++ if (size < 0) { ++ if (errno == EAGAIN) ++ goto bail; ++ bb_perror_msg_and_die("recv"); ++ } ++ addr = xmalloc_sockaddr2dotted_noport(from); ++ bb_error_msg("malformed packet received from %s: size %u", addr, (int)size); ++ free(addr); ++ goto bail; ++ } ++ ++ query_status = msg.m_status; ++ query_xmttime = msg.m_xmttime; ++ ++ /* Build a reply packet */ ++ memset(&msg, 0, sizeof(msg)); ++ msg.m_status = G.stratum < MAXSTRAT ? G.ntp_status : LI_ALARM; ++ msg.m_status |= (query_status & VERSION_MASK); ++ msg.m_status |= ((query_status & MODE_MASK) == MODE_CLIENT) ? ++ MODE_SERVER : MODE_SYM_PAS; ++ msg.m_stratum = G.stratum; ++ msg.m_ppoll = G.poll_exp; ++ msg.m_precision_exp = G_precision_exp; ++ /* this time was obtained between poll() and recv() */ ++ msg.m_rectime = d_to_lfp(G.cur_time); ++ msg.m_xmttime = d_to_lfp(gettime1900d()); /* this instant */ ++ if (G.peer_cnt == 0) { ++ /* we have no peers: "stratum 1 server" mode. reftime = our own time */ ++ G.reftime = G.cur_time; ++ } ++ msg.m_reftime = d_to_lfp(G.reftime); ++ msg.m_orgtime = query_xmttime; ++ msg.m_rootdelay = d_to_sfp(G.rootdelay); ++//simple code does not do this, fix simple code! ++ msg.m_rootdisp = d_to_sfp(G.rootdisp); ++ version = (query_status & VERSION_MASK); /* ... >> VERSION_SHIFT - done below instead */ ++ msg.m_refid = G.refid; // (version > (3 << VERSION_SHIFT)) ? G.refid : G.refid3; ++ ++ /* We reply from the local address packet was sent to, ++ * this makes to/from look swapped here: */ ++ do_sendto(G.listen_fd, ++ /*from:*/ &to->u.sa, /*to:*/ from, /*addrlen:*/ to->len, ++ &msg, size); ++ ++ bail: ++ free(to); ++ free(from); ++} ++#endif ++ ++/* Upstream ntpd's options: ++ * ++ * -4 Force DNS resolution of host names to the IPv4 namespace. ++ * -6 Force DNS resolution of host names to the IPv6 namespace. ++ * -a Require cryptographic authentication for broadcast client, ++ * multicast client and symmetric passive associations. ++ * This is the default. ++ * -A Do not require cryptographic authentication for broadcast client, ++ * multicast client and symmetric passive associations. ++ * This is almost never a good idea. ++ * -b Enable the client to synchronize to broadcast servers. ++ * -c conffile ++ * Specify the name and path of the configuration file, ++ * default /etc/ntp.conf ++ * -d Specify debugging mode. This option may occur more than once, ++ * with each occurrence indicating greater detail of display. ++ * -D level ++ * Specify debugging level directly. ++ * -f driftfile ++ * Specify the name and path of the frequency file. ++ * This is the same operation as the "driftfile FILE" ++ * configuration command. ++ * -g Normally, ntpd exits with a message to the system log ++ * if the offset exceeds the panic threshold, which is 1000 s ++ * by default. This option allows the time to be set to any value ++ * without restriction; however, this can happen only once. ++ * If the threshold is exceeded after that, ntpd will exit ++ * with a message to the system log. This option can be used ++ * with the -q and -x options. See the tinker command for other options. ++ * -i jaildir ++ * Chroot the server to the directory jaildir. This option also implies ++ * that the server attempts to drop root privileges at startup ++ * (otherwise, chroot gives very little additional security). ++ * You may need to also specify a -u option. ++ * -k keyfile ++ * Specify the name and path of the symmetric key file, ++ * default /etc/ntp/keys. This is the same operation ++ * as the "keys FILE" configuration command. ++ * -l logfile ++ * Specify the name and path of the log file. The default ++ * is the system log file. This is the same operation as ++ * the "logfile FILE" configuration command. ++ * -L Do not listen to virtual IPs. The default is to listen. ++ * -n Don't fork. ++ * -N To the extent permitted by the operating system, ++ * run the ntpd at the highest priority. ++ * -p pidfile ++ * Specify the name and path of the file used to record the ntpd ++ * process ID. This is the same operation as the "pidfile FILE" ++ * configuration command. ++ * -P priority ++ * To the extent permitted by the operating system, ++ * run the ntpd at the specified priority. ++ * -q Exit the ntpd just after the first time the clock is set. ++ * This behavior mimics that of the ntpdate program, which is ++ * to be retired. The -g and -x options can be used with this option. ++ * Note: The kernel time discipline is disabled with this option. ++ * -r broadcastdelay ++ * Specify the default propagation delay from the broadcast/multicast ++ * server to this client. This is necessary only if the delay ++ * cannot be computed automatically by the protocol. ++ * -s statsdir ++ * Specify the directory path for files created by the statistics ++ * facility. This is the same operation as the "statsdir DIR" ++ * configuration command. ++ * -t key ++ * Add a key number to the trusted key list. This option can occur ++ * more than once. ++ * -u user[:group] ++ * Specify a user, and optionally a group, to switch to. ++ * -v variable ++ * -V variable ++ * Add a system variable listed by default. ++ * -x Normally, the time is slewed if the offset is less than the step ++ * threshold, which is 128 ms by default, and stepped if above ++ * the threshold. This option sets the threshold to 600 s, which is ++ * well within the accuracy window to set the clock manually. ++ * Note: since the slew rate of typical Unix kernels is limited ++ * to 0.5 ms/s, each second of adjustment requires an amortization ++ * interval of 2000 s. Thus, an adjustment as much as 600 s ++ * will take almost 14 days to complete. This option can be used ++ * with the -g and -q options. See the tinker command for other options. ++ * Note: The kernel time discipline is disabled with this option. ++ */ ++ ++/* By doing init in a separate function we decrease stack usage ++ * in main loop. ++ */ ++static NOINLINE void ntp_init(char **argv) ++{ ++ unsigned opts; ++ llist_t *peers; ++ ++ srandom(getpid()); ++ ++ if (getuid()) ++ bb_error_msg_and_die("you must be root"); ++ ++ /* Set some globals */ ++ G.stratum = MAXSTRAT; ++ if (BURSTPOLL != 0) ++ G.poll_exp = BURSTPOLL; /* speeds up initial sync */ ++ G.last_script_run = G.reftime = G.last_update_recv_time = gettime1900d(); /* sets G.cur_time too */ ++ ++ /* Parse options */ ++ peers = NULL; ++ opt_complementary = "dd:p::wn"; /* d: counter; p: list; -w implies -n */ ++ opts = getopt32(argv, ++ "nqNx" /* compat */ ++ "wp:S:"IF_FEATURE_NTPD_SERVER("l") /* NOT compat */ ++ "d" /* compat */ ++ "46aAbgL", /* compat, ignored */ ++ &peers, &G.script_name, &G.verbose); ++ if (!(opts & (OPT_p|OPT_l))) ++ bb_show_usage(); ++// if (opts & OPT_x) /* disable stepping, only slew is allowed */ ++// G.time_was_stepped = 1; ++ if (peers) { ++ while (peers) ++ add_peers(llist_pop(&peers)); ++ } else { ++ /* -l but no peers: "stratum 1 server" mode */ ++ G.stratum = 1; ++ } ++ if (!(opts & OPT_n)) { ++ bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO, argv); ++ logmode = LOGMODE_NONE; ++ } ++#if ENABLE_FEATURE_NTPD_SERVER ++ G.listen_fd = -1; ++ if (opts & OPT_l) { ++ G.listen_fd = create_and_bind_dgram_or_die(NULL, 123); ++ socket_want_pktinfo(G.listen_fd); ++ setsockopt(G.listen_fd, IPPROTO_IP, IP_TOS, &const_IPTOS_LOWDELAY, sizeof(const_IPTOS_LOWDELAY)); ++ } ++#endif ++ /* I hesitate to set -20 prio. -15 should be high enough for timekeeping */ ++ if (opts & OPT_N) ++ setpriority(PRIO_PROCESS, 0, -15); ++ ++ /* If network is up, syncronization occurs in ~10 seconds. ++ * We give "ntpd -q" a full minute to finish, then we exit. ++ * ++ * I tested ntpd 4.2.6p1 and apparently it never exits ++ * (will try forever), but it does not feel right. ++ * The goal of -q is to act like ntpdate: set time ++ * after a reasonably small period of polling, or fail. ++ */ ++ if (opts & OPT_q) ++ alarm(60); ++ ++ bb_signals(0 ++ | (1 << SIGTERM) ++ | (1 << SIGINT) ++ | (1 << SIGALRM) ++ , record_signo ++ ); ++ bb_signals(0 ++ | (1 << SIGPIPE) ++ | (1 << SIGCHLD) ++ , SIG_IGN ++ ); ++} ++ ++int ntpd_main(int argc UNUSED_PARAM, char **argv) MAIN_EXTERNALLY_VISIBLE; ++int ntpd_main(int argc UNUSED_PARAM, char **argv) ++{ ++#undef G ++ struct globals G; ++ struct pollfd *pfd; ++ peer_t **idx2peer; ++ unsigned cnt; ++ ++ memset(&G, 0, sizeof(G)); ++ SET_PTR_TO_GLOBALS(&G); ++ ++ ntp_init(argv); ++ ++ /* If ENABLE_FEATURE_NTPD_SERVER, + 1 for listen_fd: */ ++ cnt = G.peer_cnt + ENABLE_FEATURE_NTPD_SERVER; ++ idx2peer = xzalloc(sizeof(idx2peer[0]) * cnt); ++ pfd = xzalloc(sizeof(pfd[0]) * cnt); ++ ++ /* Countdown: we never sync before we sent INITIAL_SAMPLES+1 ++ * packets to each peer. ++ * NB: if some peer is not responding, we may end up sending ++ * fewer packets to it and more to other peers. ++ * NB2: sync usually happens using INITIAL_SAMPLES packets, ++ * since last reply does not come back instantaneously. ++ */ ++ cnt = G.peer_cnt * (INITIAL_SAMPLES + 1); ++ ++ while (!bb_got_signal) { ++ llist_t *item; ++ unsigned i, j; ++ int nfds, timeout; ++ double nextaction; ++ ++ /* Nothing between here and poll() blocks for any significant time */ ++ ++ nextaction = G.cur_time + 3600; ++ ++ i = 0; ++#if ENABLE_FEATURE_NTPD_SERVER ++ if (G.listen_fd != -1) { ++ pfd[0].fd = G.listen_fd; ++ pfd[0].events = POLLIN; ++ i++; ++ } ++#endif ++ /* Pass over peer list, send requests, time out on receives */ ++ for (item = G.ntp_peers; item != NULL; item = item->link) { ++ peer_t *p = (peer_t *) item->data; ++ ++ if (p->next_action_time <= G.cur_time) { ++ if (p->p_fd == -1) { ++ /* Time to send new req */ ++ if (--cnt == 0) { ++ G.initial_poll_complete = 1; ++ } ++ send_query_to_peer(p); ++ } else { ++ /* Timed out waiting for reply */ ++ close(p->p_fd); ++ p->p_fd = -1; ++ timeout = poll_interval(-2); /* -2: try a bit sooner */ ++ bb_error_msg("timed out waiting for %s, reach 0x%02x, next query in %us", ++ p->p_dotted, p->reachable_bits, timeout); ++ set_next(p, timeout); ++ } ++ } ++ ++ if (p->next_action_time < nextaction) ++ nextaction = p->next_action_time; ++ ++ if (p->p_fd >= 0) { ++ /* Wait for reply from this peer */ ++ pfd[i].fd = p->p_fd; ++ pfd[i].events = POLLIN; ++ idx2peer[i] = p; ++ i++; ++ } ++ } ++ ++ timeout = nextaction - G.cur_time; ++ if (timeout < 0) ++ timeout = 0; ++ timeout++; /* (nextaction - G.cur_time) rounds down, compensating */ ++ ++ /* Here we may block */ ++ VERB2 bb_error_msg("poll %us, sockets:%u, poll interval:%us", timeout, i, 1 << G.poll_exp); ++ nfds = poll(pfd, i, timeout * 1000); ++ gettime1900d(); /* sets G.cur_time */ ++ if (nfds <= 0) { ++ if (G.script_name && G.cur_time - G.last_script_run > 11*60) { ++ /* Useful for updating battery-backed RTC and such */ ++ run_script("periodic", G.last_update_offset); ++ gettime1900d(); /* sets G.cur_time */ ++ } ++ continue; ++ } ++ ++ /* Process any received packets */ ++ j = 0; ++#if ENABLE_FEATURE_NTPD_SERVER ++ if (G.listen_fd != -1) { ++ if (pfd[0].revents /* & (POLLIN|POLLERR)*/) { ++ nfds--; ++ recv_and_process_client_pkt(/*G.listen_fd*/); ++ gettime1900d(); /* sets G.cur_time */ ++ } ++ j = 1; ++ } ++#endif ++ for (; nfds != 0 && j < i; j++) { ++ if (pfd[j].revents /* & (POLLIN|POLLERR)*/) { ++ nfds--; ++ recv_and_process_peer_pkt(idx2peer[j]); ++ gettime1900d(); /* sets G.cur_time */ ++ } ++ } ++ } /* while (!bb_got_signal) */ ++ ++ kill_myself_with_sig(bb_got_signal); ++} ++ ++ ++ ++ ++ ++ ++/*** openntpd-4.6 uses only adjtime, not adjtimex ***/ ++ ++/*** ntp-4.2.6/ntpd/ntp_loopfilter.c - adjtimex usage ***/ ++ ++#if 0 ++static double ++direct_freq(double fp_offset) ++{ ++#ifdef KERNEL_PLL ++ /* ++ * If the kernel is enabled, we need the residual offset to ++ * calculate the frequency correction. ++ */ ++ if (pll_control && kern_enable) { ++ memset(&ntv, 0, sizeof(ntv)); ++ ntp_adjtime(&ntv); ++#ifdef STA_NANO ++ clock_offset = ntv.offset / 1e9; ++#else /* STA_NANO */ ++ clock_offset = ntv.offset / 1e6; ++#endif /* STA_NANO */ ++ drift_comp = FREQTOD(ntv.freq); ++ } ++#endif /* KERNEL_PLL */ ++ set_freq((fp_offset - clock_offset) / (current_time - clock_epoch) + drift_comp); ++ wander_resid = 0; ++ return drift_comp; ++} ++ ++static void ++set_freq(double freq) /* frequency update */ ++{ ++ char tbuf[80]; ++ ++ drift_comp = freq; ++ ++#ifdef KERNEL_PLL ++ /* ++ * If the kernel is enabled, update the kernel frequency. ++ */ ++ if (pll_control && kern_enable) { ++ memset(&ntv, 0, sizeof(ntv)); ++ ntv.modes = MOD_FREQUENCY; ++ ntv.freq = DTOFREQ(drift_comp); ++ ntp_adjtime(&ntv); ++ snprintf(tbuf, sizeof(tbuf), "kernel %.3f PPM", drift_comp * 1e6); ++ report_event(EVNT_FSET, NULL, tbuf); ++ } else { ++ snprintf(tbuf, sizeof(tbuf), "ntpd %.3f PPM", drift_comp * 1e6); ++ report_event(EVNT_FSET, NULL, tbuf); ++ } ++#else /* KERNEL_PLL */ ++ snprintf(tbuf, sizeof(tbuf), "ntpd %.3f PPM", drift_comp * 1e6); ++ report_event(EVNT_FSET, NULL, tbuf); ++#endif /* KERNEL_PLL */ ++} ++ ++... ++... ++... ++ ++#ifdef KERNEL_PLL ++ /* ++ * This code segment works when clock adjustments are made using ++ * precision time kernel support and the ntp_adjtime() system ++ * call. This support is available in Solaris 2.6 and later, ++ * Digital Unix 4.0 and later, FreeBSD, Linux and specially ++ * modified kernels for HP-UX 9 and Ultrix 4. In the case of the ++ * DECstation 5000/240 and Alpha AXP, additional kernel ++ * modifications provide a true microsecond clock and nanosecond ++ * clock, respectively. ++ * ++ * Important note: The kernel discipline is used only if the ++ * step threshold is less than 0.5 s, as anything higher can ++ * lead to overflow problems. This might occur if some misguided ++ * lad set the step threshold to something ridiculous. ++ */ ++ if (pll_control && kern_enable) { ++ ++#define MOD_BITS (MOD_OFFSET | MOD_MAXERROR | MOD_ESTERROR | MOD_STATUS | MOD_TIMECONST) ++ ++ /* ++ * We initialize the structure for the ntp_adjtime() ++ * system call. We have to convert everything to ++ * microseconds or nanoseconds first. Do not update the ++ * system variables if the ext_enable flag is set. In ++ * this case, the external clock driver will update the ++ * variables, which will be read later by the local ++ * clock driver. Afterwards, remember the time and ++ * frequency offsets for jitter and stability values and ++ * to update the frequency file. ++ */ ++ memset(&ntv, 0, sizeof(ntv)); ++ if (ext_enable) { ++ ntv.modes = MOD_STATUS; ++ } else { ++#ifdef STA_NANO ++ ntv.modes = MOD_BITS | MOD_NANO; ++#else /* STA_NANO */ ++ ntv.modes = MOD_BITS; ++#endif /* STA_NANO */ ++ if (clock_offset < 0) ++ dtemp = -.5; ++ else ++ dtemp = .5; ++#ifdef STA_NANO ++ ntv.offset = (int32)(clock_offset * 1e9 + dtemp); ++ ntv.constant = sys_poll; ++#else /* STA_NANO */ ++ ntv.offset = (int32)(clock_offset * 1e6 + dtemp); ++ ntv.constant = sys_poll - 4; ++#endif /* STA_NANO */ ++ ntv.esterror = (u_int32)(clock_jitter * 1e6); ++ ntv.maxerror = (u_int32)((sys_rootdelay / 2 + sys_rootdisp) * 1e6); ++ ntv.status = STA_PLL; ++ ++ /* ++ * Enable/disable the PPS if requested. ++ */ ++ if (pps_enable) { ++ if (!(pll_status & STA_PPSTIME)) ++ report_event(EVNT_KERN, ++ NULL, "PPS enabled"); ++ ntv.status |= STA_PPSTIME | STA_PPSFREQ; ++ } else { ++ if (pll_status & STA_PPSTIME) ++ report_event(EVNT_KERN, ++ NULL, "PPS disabled"); ++ ntv.status &= ~(STA_PPSTIME | ++ STA_PPSFREQ); ++ } ++ if (sys_leap == LEAP_ADDSECOND) ++ ntv.status |= STA_INS; ++ else if (sys_leap == LEAP_DELSECOND) ++ ntv.status |= STA_DEL; ++ } ++ ++ /* ++ * Pass the stuff to the kernel. If it squeals, turn off ++ * the pps. In any case, fetch the kernel offset, ++ * frequency and jitter. ++ */ ++ if (ntp_adjtime(&ntv) == TIME_ERROR) { ++ if (!(ntv.status & STA_PPSSIGNAL)) ++ report_event(EVNT_KERN, NULL, ++ "PPS no signal"); ++ } ++ pll_status = ntv.status; ++#ifdef STA_NANO ++ clock_offset = ntv.offset / 1e9; ++#else /* STA_NANO */ ++ clock_offset = ntv.offset / 1e6; ++#endif /* STA_NANO */ ++ clock_frequency = FREQTOD(ntv.freq); ++ ++ /* ++ * If the kernel PPS is lit, monitor its performance. ++ */ ++ if (ntv.status & STA_PPSTIME) { ++#ifdef STA_NANO ++ clock_jitter = ntv.jitter / 1e9; ++#else /* STA_NANO */ ++ clock_jitter = ntv.jitter / 1e6; ++#endif /* STA_NANO */ ++ } ++ ++#if defined(STA_NANO) && NTP_API == 4 ++ /* ++ * If the TAI changes, update the kernel TAI. ++ */ ++ if (loop_tai != sys_tai) { ++ loop_tai = sys_tai; ++ ntv.modes = MOD_TAI; ++ ntv.constant = sys_tai; ++ ntp_adjtime(&ntv); ++ } ++#endif /* STA_NANO */ ++ } ++#endif /* KERNEL_PLL */ ++#endif +--- a/networking/Kbuild ++++ b/networking/Kbuild +@@ -28,6 +28,7 @@ lib-$(CONFIG_NC) += nc.o + lib-$(CONFIG_NETMSG) += netmsg.o + lib-$(CONFIG_NETSTAT) += netstat.o + lib-$(CONFIG_NSLOOKUP) += nslookup.o ++lib-$(CONFIG_NTPD) += ntpd.o + lib-$(CONFIG_PING) += ping.o + lib-$(CONFIG_PING6) += ping.o + lib-$(CONFIG_PSCAN) += pscan.o