mirror of
https://github.com/sheumann/hush.git
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ntpd: new applet by Adam Tkac. +5k.
Signed-off-by: Adam Tkac <vonsch@gmail.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Adam Tkac
Denys Vlasenko
parent
d095fd4d95
commit
b1585064fd
@ -285,6 +285,7 @@ IF_NICE(APPLET(nice, _BB_DIR_BIN, _BB_SUID_DROP))
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IF_NMETER(APPLET(nmeter, _BB_DIR_USR_BIN, _BB_SUID_DROP))
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IF_NOHUP(APPLET(nohup, _BB_DIR_USR_BIN, _BB_SUID_DROP))
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IF_NSLOOKUP(APPLET(nslookup, _BB_DIR_USR_BIN, _BB_SUID_DROP))
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IF_NTPD(APPLET(ntpd, _BB_DIR_USR_SBIN, _BB_SUID_DROP))
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IF_OD(APPLET(od, _BB_DIR_USR_BIN, _BB_SUID_DROP))
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IF_OPENVT(APPLET(openvt, _BB_DIR_USR_BIN, _BB_SUID_DROP))
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//IF_PARSE(APPLET(parse, _BB_DIR_USR_BIN, _BB_SUID_DROP))
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@ -3210,6 +3210,17 @@
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"Name: debian\n" \
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"Address: 127.0.0.1\n"
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#define ntpd_trivial_usage \
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"[-dngl] [-p PEER]..."
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#define ntpd_full_usage "\n\n" \
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"NTP client/server\n" \
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"\nOptions:" \
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"\n -d Verbose" \
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"\n -n Do not daemonize" \
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"\n -g Set system time even if offset is > 1000 sec" \
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"\n -l Run as server on port 123" \
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"\n -p PEER Obtain time from PEER (may be repeated)" \
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#define od_trivial_usage \
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"[-aBbcDdeFfHhIiLlOovXx] " IF_DESKTOP("[-t TYPE] ") "[FILE]"
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#define od_full_usage "\n\n" \
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@ -661,6 +661,20 @@ config NSLOOKUP
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help
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nslookup is a tool to query Internet name servers.
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config NTPD
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bool "ntpd"
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default n
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help
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The NTP client/server daemon.
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config FEATURE_NTPD_SERVER
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bool "Make ntpd usable as a NTP server"
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default y
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depends on NTPD
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help
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Make ntpd usable as a NTP server. If you disable this option
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ntpd will be usable only as a NTP client.
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config PING
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bool "ping"
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default n
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@ -27,6 +27,7 @@ lib-$(CONFIG_NAMEIF) += nameif.o
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lib-$(CONFIG_NC) += nc.o
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lib-$(CONFIG_NETSTAT) += netstat.o
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lib-$(CONFIG_NSLOOKUP) += nslookup.o
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lib-$(CONFIG_NTPD) += ntpd.o
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lib-$(CONFIG_PING) += ping.o
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lib-$(CONFIG_PING6) += ping.o
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lib-$(CONFIG_PSCAN) += pscan.o
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999
networking/ntpd.c
Normal file
999
networking/ntpd.c
Normal file
@ -0,0 +1,999 @@
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/*
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* NTP client/server, based on OpenNTPD 3.9p1
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*
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* Author: Adam Tkac <vonsch@gmail.com>
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*
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* Licensed under GPLv2, see file LICENSE in this tarball for details.
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*/
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#include "libbb.h"
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#include <netinet/ip.h> /* For IPTOS_LOWDELAY definition */
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#ifndef IP_PKTINFO
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# error "Sorry, your kernel has to support IP_PKTINFO"
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#endif
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#define INTERVAL_QUERY_NORMAL 30 /* sync to peers every n secs */
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#define INTERVAL_QUERY_PATHETIC 60
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#define INTERVAL_QUERY_AGRESSIVE 5
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#define TRUSTLEVEL_BADPEER 6
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#define TRUSTLEVEL_PATHETIC 2
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#define TRUSTLEVEL_AGRESSIVE 8
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#define TRUSTLEVEL_MAX 10
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#define QSCALE_OFF_MIN 0.05
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#define QSCALE_OFF_MAX 0.50
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#define QUERYTIME_MAX 15 /* single query might take n secs max */
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#define OFFSET_ARRAY_SIZE 8
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#define SETTIME_MIN_OFFSET 180 /* min offset for settime at start */
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#define SETTIME_TIMEOUT 15 /* max seconds to wait with -s */
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/* Style borrowed from NTP ref/tcpdump and updated for SNTPv4 (RFC2030). */
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/*
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* RFC Section 3
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*
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* 0 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Integer Part |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Fraction Part |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*
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* 0 1 2 3
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* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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* | Integer Part | Fraction Part |
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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typedef struct {
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uint32_t int_partl;
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uint32_t fractionl;
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} l_fixedpt_t;
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typedef struct {
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uint16_t int_parts;
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uint16_t fractions;
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} s_fixedpt_t;
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#define NTP_DIGESTSIZE 16
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#define NTP_MSGSIZE_NOAUTH 48
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#define NTP_MSGSIZE (NTP_MSGSIZE_NOAUTH + 4 + NTP_DIGESTSIZE)
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typedef struct {
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uint8_t status; /* status of local clock and leap info */
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uint8_t stratum; /* Stratum level */
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uint8_t ppoll; /* poll value */
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int8_t precision;
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s_fixedpt_t rootdelay;
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s_fixedpt_t dispersion;
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uint32_t refid;
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l_fixedpt_t reftime;
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l_fixedpt_t orgtime;
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l_fixedpt_t rectime;
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l_fixedpt_t xmttime;
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uint32_t keyid;
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uint8_t digest[NTP_DIGESTSIZE];
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} ntp_msg_t;
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typedef struct {
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int fd;
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ntp_msg_t msg;
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double xmttime;
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} ntp_query_t;
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enum {
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NTP_VERSION = 4,
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NTP_MAXSTRATUM = 15,
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/* Leap Second Codes (high order two bits) */
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LI_NOWARNING = (0 << 6), /* no warning */
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LI_PLUSSEC = (1 << 6), /* add a second (61 seconds) */
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LI_MINUSSEC = (2 << 6), /* minus a second (59 seconds) */
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LI_ALARM = (3 << 6), /* alarm condition */
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/* Status Masks */
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MODE_MASK = (7 << 0),
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VERSION_MASK = (7 << 3),
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LI_MASK = (3 << 6),
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/* Mode values */
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MODE_RES0 = 0, /* reserved */
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MODE_SYM_ACT = 1, /* symmetric active */
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MODE_SYM_PAS = 2, /* symmetric passive */
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MODE_CLIENT = 3, /* client */
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MODE_SERVER = 4, /* server */
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MODE_BROADCAST = 5, /* broadcast */
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MODE_RES1 = 6, /* reserved for NTP control message */
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MODE_RES2 = 7 /* reserved for private use */
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};
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#define JAN_1970 2208988800UL /* 1970 - 1900 in seconds */
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enum client_state {
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STATE_NONE,
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STATE_QUERY_SENT,
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STATE_REPLY_RECEIVED
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};
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typedef struct {
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double rootdelay;
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double rootdispersion;
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double reftime;
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uint32_t refid;
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uint32_t refid4;
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uint8_t synced;
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uint8_t leap;
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int8_t precision;
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uint8_t poll;
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uint8_t stratum;
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} ntp_status_t;
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typedef struct {
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ntp_status_t status;
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double offset;
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double delay;
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double error;
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time_t rcvd;
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uint8_t good;
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} ntp_offset_t;
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typedef struct {
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len_and_sockaddr *lsa;
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ntp_query_t query;
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ntp_offset_t reply[OFFSET_ARRAY_SIZE];
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ntp_offset_t update;
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enum client_state state;
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time_t next;
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time_t deadline;
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uint8_t shift;
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uint8_t trustlevel;
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} ntp_peer_t;
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struct globals {
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unsigned verbose;
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#if ENABLE_FEATURE_NTPD_SERVER
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int listen_fd;
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#endif
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llist_t *ntp_peers;
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ntp_status_t status;
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uint32_t scale;
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uint8_t settime;
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uint8_t firstadj;
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smallint peer_cnt;
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};
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#define G (*ptr_to_globals)
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static const int const_IPTOS_LOWDELAY = IPTOS_LOWDELAY;
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static void
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set_next(ntp_peer_t *p, time_t t)
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{
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p->next = time(NULL) + t;
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p->deadline = 0;
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}
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static void
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add_peers(const char *s)
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{
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ntp_peer_t *p;
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p = xzalloc(sizeof(*p));
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//TODO: big ntpd uses all IPs, not just 1st, do we need to mimic that?
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p->lsa = xhost2sockaddr(s, 123);
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p->query.fd = -1;
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p->query.msg.status = MODE_CLIENT | (NTP_VERSION << 3);
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if (STATE_NONE != 0)
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p->state = STATE_NONE;
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p->trustlevel = TRUSTLEVEL_PATHETIC;
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p->query.fd = -1;
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set_next(p, 0);
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llist_add_to(&G.ntp_peers, p);
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G.peer_cnt++;
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}
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static double
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gettime(void)
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{
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struct timeval tv;
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gettimeofday(&tv, NULL); /* never fails */
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return (tv.tv_sec + JAN_1970 + 1.0e-6 * tv.tv_usec);
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}
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static void
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d_to_tv(double d, struct timeval *tv)
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{
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tv->tv_sec = (long)d;
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tv->tv_usec = (d - tv->tv_sec) * 1000000;
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}
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static double
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lfp_to_d(l_fixedpt_t lfp)
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{
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double ret;
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lfp.int_partl = ntohl(lfp.int_partl);
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lfp.fractionl = ntohl(lfp.fractionl);
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ret = (double)(lfp.int_partl) + ((double)lfp.fractionl / UINT_MAX);
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return ret;
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}
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#if ENABLE_FEATURE_NTPD_SERVER
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static l_fixedpt_t
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d_to_lfp(double d)
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{
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l_fixedpt_t lfp;
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lfp.int_partl = htonl((uint32_t)d);
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lfp.fractionl = htonl((uint32_t)((d - (u_int32_t)d) * UINT_MAX));
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return lfp;
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}
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#endif
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static double
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sfp_to_d(s_fixedpt_t sfp)
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{
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double ret;
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sfp.int_parts = ntohs(sfp.int_parts);
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sfp.fractions = ntohs(sfp.fractions);
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ret = (double)(sfp.int_parts) + ((double)sfp.fractions / USHRT_MAX);
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return ret;
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}
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#if ENABLE_FEATURE_NTPD_SERVER
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static s_fixedpt_t
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d_to_sfp(double d)
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{
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s_fixedpt_t sfp;
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sfp.int_parts = htons((uint16_t)d);
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sfp.fractions = htons((uint16_t)((d - (u_int16_t)d) * USHRT_MAX));
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return sfp;
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}
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#endif
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static void
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set_deadline(ntp_peer_t *p, time_t t)
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{
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p->deadline = time(NULL) + t;
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p->next = 0;
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}
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static time_t
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error_interval(void)
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{
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time_t interval, r;
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interval = INTERVAL_QUERY_PATHETIC * QSCALE_OFF_MAX / QSCALE_OFF_MIN;
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r = random() % (interval / 10);
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return (interval + r);
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}
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static int
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sendmsg_wrap(int fd,
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const struct sockaddr *from, const struct sockaddr *to, socklen_t addrlen,
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ntp_msg_t *msg, ssize_t len)
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{
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ssize_t ret;
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errno = 0;
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if (!from) {
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ret = sendto(fd, msg, len, 0, to, addrlen);
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} else {
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ret = send_to_from(fd, msg, len, 0, to, from, addrlen);
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}
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if (ret != len) {
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bb_perror_msg("send failed");
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return -1;
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}
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return 0;
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}
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static int
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client_query(ntp_peer_t *p)
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{
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if (p->query.fd == -1) {
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p->query.fd = xsocket(p->lsa->u.sa.sa_family, SOCK_DGRAM, 0);
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#if ENABLE_FEATURE_IPV6
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if (p->lsa->u.sa.sa_family == AF_INET)
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#endif
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setsockopt(p->query.fd, IPPROTO_IP, IP_TOS, &const_IPTOS_LOWDELAY, sizeof(const_IPTOS_LOWDELAY));
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}
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/*
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* Send out a random 64-bit number as our transmit time. The NTP
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* server will copy said number into the originate field on the
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* response that it sends us. This is totally legal per the SNTP spec.
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*
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* The impact of this is two fold: we no longer send out the current
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* system time for the world to see (which may aid an attacker), and
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* it gives us a (not very secure) way of knowing that we're not
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* getting spoofed by an attacker that can't capture our traffic
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* but can spoof packets from the NTP server we're communicating with.
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*
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* Save the real transmit timestamp locally.
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*/
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p->query.msg.xmttime.int_partl = random();
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p->query.msg.xmttime.fractionl = random();
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p->query.xmttime = gettime();
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if (sendmsg_wrap(p->query.fd, /*from:*/ NULL, /*to:*/ &p->lsa->u.sa, /*addrlen:*/ p->lsa->len,
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&p->query.msg, NTP_MSGSIZE_NOAUTH) == -1) {
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set_next(p, INTERVAL_QUERY_PATHETIC);
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return -1;
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}
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p->state = STATE_QUERY_SENT;
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set_deadline(p, QUERYTIME_MAX);
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return 0;
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}
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static int
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offset_compare(const void *aa, const void *bb)
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{
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const ntp_peer_t * const *a;
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const ntp_peer_t * const *b;
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a = aa;
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b = bb;
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if ((*a)->update.offset < (*b)->update.offset)
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return -1;
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return ((*a)->update.offset > (*b)->update.offset);
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}
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static uint32_t
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updated_scale(double offset)
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{
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if (offset < 0)
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offset = -offset;
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if (offset > QSCALE_OFF_MAX)
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return 1;
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if (offset < QSCALE_OFF_MIN)
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return QSCALE_OFF_MAX / QSCALE_OFF_MIN;
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return QSCALE_OFF_MAX / offset;
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}
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static void
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adjtime_wrap(void)
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{
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ntp_peer_t *p;
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unsigned offset_cnt;
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int i = 0;
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ntp_peer_t **peers;
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double offset_median;
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llist_t *item;
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len_and_sockaddr *lsa;
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struct timeval tv, olddelta;
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offset_cnt = 0;
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for (item = G.ntp_peers; item != NULL; item = item->link) {
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p = (ntp_peer_t *) item->data;
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if (p->trustlevel < TRUSTLEVEL_BADPEER)
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continue;
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if (!p->update.good)
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return;
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offset_cnt++;
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}
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peers = xzalloc(sizeof(ntp_peer_t *) * offset_cnt);
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for (item = G.ntp_peers; item != NULL; item = item->link) {
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p = (ntp_peer_t *) item->data;
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if (p->trustlevel < TRUSTLEVEL_BADPEER)
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continue;
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peers[i++] = p;
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}
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qsort(peers, offset_cnt, sizeof(ntp_peer_t *), offset_compare);
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if (offset_cnt != 0) {
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if ((offset_cnt & 1) == 0) {
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//TODO: try offset_cnt /= 2...
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offset_median =
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(peers[offset_cnt / 2 - 1]->update.offset +
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peers[offset_cnt / 2]->update.offset) / 2;
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G.status.rootdelay =
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(peers[offset_cnt / 2 - 1]->update.delay +
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peers[offset_cnt / 2]->update.delay) / 2;
|
||||
G.status.stratum = MAX(
|
||||
peers[offset_cnt / 2 - 1]->update.status.stratum,
|
||||
peers[offset_cnt / 2]->update.status.stratum);
|
||||
} else {
|
||||
offset_median = peers[offset_cnt / 2]->update.offset;
|
||||
G.status.rootdelay = peers[offset_cnt / 2]->update.delay;
|
||||
G.status.stratum = peers[offset_cnt / 2]->update.status.stratum;
|
||||
}
|
||||
G.status.leap = peers[offset_cnt / 2]->update.status.leap;
|
||||
|
||||
bb_info_msg("adjusting local clock by %fs", offset_median);
|
||||
|
||||
d_to_tv(offset_median, &tv);
|
||||
if (adjtime(&tv, &olddelta) == -1)
|
||||
bb_error_msg("adjtime failed");
|
||||
else if (!G.firstadj
|
||||
&& olddelta.tv_sec == 0
|
||||
&& olddelta.tv_usec == 0
|
||||
&& !G.status.synced
|
||||
) {
|
||||
bb_info_msg("clock synced");
|
||||
G.status.synced = 1;
|
||||
} else if (G.status.synced) {
|
||||
bb_info_msg("clock unsynced");
|
||||
G.status.synced = 0;
|
||||
}
|
||||
|
||||
G.firstadj = 0;
|
||||
G.status.reftime = gettime();
|
||||
G.status.stratum++; /* one more than selected peer */
|
||||
G.scale = updated_scale(offset_median);
|
||||
|
||||
G.status.refid4 = peers[offset_cnt / 2]->update.status.refid4;
|
||||
|
||||
lsa = peers[offset_cnt / 2]->lsa;
|
||||
G.status.refid =
|
||||
#if ENABLE_FEATURE_IPV6
|
||||
lsa->u.sa.sa_family != AF_INET ?
|
||||
G.status.refid4 :
|
||||
#endif
|
||||
lsa->u.sin.sin_addr.s_addr;
|
||||
}
|
||||
|
||||
free(peers);
|
||||
|
||||
for (item = G.ntp_peers; item != NULL; item = item->link) {
|
||||
p = (ntp_peer_t *) item->data;
|
||||
p->update.good = 0;
|
||||
}
|
||||
}
|
||||
|
||||
static void
|
||||
settime(double offset)
|
||||
{
|
||||
ntp_peer_t *p;
|
||||
llist_t *item;
|
||||
struct timeval tv, curtime;
|
||||
char buf[80];
|
||||
time_t tval;
|
||||
|
||||
#if 0
|
||||
if (!G.settime)
|
||||
return;
|
||||
#endif
|
||||
|
||||
/* if the offset is small, don't call settimeofday */
|
||||
if (offset < SETTIME_MIN_OFFSET && offset > -SETTIME_MIN_OFFSET)
|
||||
return;
|
||||
|
||||
gettimeofday(&curtime, NULL); /* never fails */
|
||||
|
||||
d_to_tv(offset, &tv);
|
||||
curtime.tv_usec += tv.tv_usec + 1000000;
|
||||
curtime.tv_sec += tv.tv_sec - 1 + (curtime.tv_usec / 1000000);
|
||||
curtime.tv_usec %= 1000000;
|
||||
|
||||
if (settimeofday(&curtime, NULL) == -1) {
|
||||
bb_error_msg("settimeofday");
|
||||
return;
|
||||
}
|
||||
|
||||
G.settime = 0;
|
||||
|
||||
tval = curtime.tv_sec;
|
||||
strftime(buf, sizeof(buf), "%a %b %e %H:%M:%S %Z %Y", localtime(&tval));
|
||||
|
||||
/* Do we want to print message below to system log when daemonized? */
|
||||
bb_info_msg("set local clock to %s (offset %fs)", buf, offset);
|
||||
|
||||
for (item = G.ntp_peers; item != NULL; item = item->link) {
|
||||
p = (ntp_peer_t *) item->data;
|
||||
if (p->next)
|
||||
p->next -= offset;
|
||||
if (p->deadline)
|
||||
p->deadline -= offset;
|
||||
}
|
||||
}
|
||||
|
||||
static void
|
||||
client_update(ntp_peer_t *p)
|
||||
{
|
||||
int i, best = 0, good = 0;
|
||||
|
||||
/*
|
||||
* clock filter
|
||||
* find the offset which arrived with the lowest delay
|
||||
* use that as the peer update
|
||||
* invalidate it and all older ones
|
||||
*/
|
||||
|
||||
for (i = 0; good == 0 && i < OFFSET_ARRAY_SIZE; i++) {
|
||||
if (p->reply[i].good) {
|
||||
good++;
|
||||
best = i;
|
||||
}
|
||||
}
|
||||
|
||||
for (; i < OFFSET_ARRAY_SIZE; i++) {
|
||||
if (p->reply[i].good) {
|
||||
good++;
|
||||
if (p->reply[i].delay < p->reply[best].delay)
|
||||
best = i;
|
||||
}
|
||||
}
|
||||
|
||||
if (good < 8)
|
||||
return;
|
||||
|
||||
memcpy(&p->update, &p->reply[best], sizeof(p->update));
|
||||
adjtime_wrap();
|
||||
|
||||
for (i = 0; i < OFFSET_ARRAY_SIZE; i++)
|
||||
if (p->reply[i].rcvd <= p->reply[best].rcvd)
|
||||
p->reply[i].good = 0;
|
||||
}
|
||||
|
||||
static time_t
|
||||
scale_interval(time_t requested)
|
||||
{
|
||||
time_t interval, r;
|
||||
|
||||
interval = requested * G.scale;
|
||||
r = random() % MAX(5, interval / 10);
|
||||
return (interval + r);
|
||||
}
|
||||
|
||||
static void
|
||||
client_dispatch(ntp_peer_t *p)
|
||||
{
|
||||
char *addr;
|
||||
ssize_t size;
|
||||
ntp_msg_t msg;
|
||||
double T1, T2, T3, T4;
|
||||
time_t interval;
|
||||
ntp_offset_t *offset;
|
||||
|
||||
addr = xmalloc_sockaddr2dotted_noport(&p->lsa->u.sa);
|
||||
|
||||
size = recvfrom(p->query.fd, &msg, sizeof(msg), 0, NULL, NULL);
|
||||
if (size == -1) {
|
||||
bb_perror_msg("recvfrom(%s) error", addr);
|
||||
if (errno == EHOSTUNREACH || errno == EHOSTDOWN
|
||||
|| errno == ENETUNREACH || errno == ENETDOWN
|
||||
|| errno == ECONNREFUSED || errno == EADDRNOTAVAIL
|
||||
) {
|
||||
//TODO: always do this?
|
||||
set_next(p, error_interval());
|
||||
goto bail;
|
||||
}
|
||||
xfunc_die();
|
||||
}
|
||||
|
||||
T4 = gettime();
|
||||
|
||||
if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE) {
|
||||
bb_error_msg("malformed packet received from %s", addr);
|
||||
goto bail;
|
||||
}
|
||||
|
||||
if (msg.orgtime.int_partl != p->query.msg.xmttime.int_partl
|
||||
|| msg.orgtime.fractionl != p->query.msg.xmttime.fractionl
|
||||
) {
|
||||
goto bail;
|
||||
}
|
||||
|
||||
if ((msg.status & LI_ALARM) == LI_ALARM
|
||||
|| msg.stratum == 0
|
||||
|| msg.stratum > NTP_MAXSTRATUM
|
||||
) {
|
||||
interval = error_interval();
|
||||
bb_info_msg("reply from %s: not synced, next query %ds", addr, (int) interval);
|
||||
goto bail;
|
||||
}
|
||||
|
||||
/*
|
||||
* 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 d and local clock offset t are defined as
|
||||
*
|
||||
* d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2.
|
||||
*/
|
||||
|
||||
T1 = p->query.xmttime;
|
||||
T2 = lfp_to_d(msg.rectime);
|
||||
T3 = lfp_to_d(msg.xmttime);
|
||||
|
||||
offset = &p->reply[p->shift];
|
||||
|
||||
offset->offset = ((T2 - T1) + (T3 - T4)) / 2;
|
||||
offset->delay = (T4 - T1) - (T3 - T2);
|
||||
if (offset->delay < 0) {
|
||||
interval = error_interval();
|
||||
set_next(p, interval);
|
||||
bb_info_msg("reply from %s: negative delay %f", addr, p->reply[p->shift].delay);
|
||||
goto bail;
|
||||
}
|
||||
offset->error = (T2 - T1) - (T3 - T4);
|
||||
offset->rcvd = time(NULL);
|
||||
offset->good = 1;
|
||||
|
||||
offset->status.leap = (msg.status & LI_MASK);
|
||||
offset->status.precision = msg.precision;
|
||||
offset->status.rootdelay = sfp_to_d(msg.rootdelay);
|
||||
offset->status.rootdispersion = sfp_to_d(msg.dispersion);
|
||||
offset->status.refid = ntohl(msg.refid);
|
||||
offset->status.refid4 = msg.xmttime.fractionl;
|
||||
offset->status.reftime = lfp_to_d(msg.reftime);
|
||||
offset->status.poll = msg.ppoll;
|
||||
offset->status.stratum = msg.stratum;
|
||||
|
||||
if (p->trustlevel < TRUSTLEVEL_PATHETIC)
|
||||
interval = scale_interval(INTERVAL_QUERY_PATHETIC);
|
||||
else if (p->trustlevel < TRUSTLEVEL_AGRESSIVE)
|
||||
interval = scale_interval(INTERVAL_QUERY_AGRESSIVE);
|
||||
else
|
||||
interval = scale_interval(INTERVAL_QUERY_NORMAL);
|
||||
|
||||
set_next(p, interval);
|
||||
p->state = STATE_REPLY_RECEIVED;
|
||||
|
||||
/* every received reply which we do not discard increases trust */
|
||||
if (p->trustlevel < TRUSTLEVEL_MAX) {
|
||||
if (p->trustlevel < TRUSTLEVEL_BADPEER
|
||||
&& p->trustlevel + 1 >= TRUSTLEVEL_BADPEER
|
||||
) {
|
||||
bb_info_msg("peer %s now valid", addr);
|
||||
}
|
||||
p->trustlevel++;
|
||||
}
|
||||
|
||||
bb_info_msg("reply from %s: offset %f delay %f, next query %ds", addr,
|
||||
offset->offset, offset->delay, (int) interval);
|
||||
|
||||
client_update(p);
|
||||
if (!G.settime)
|
||||
settime(offset->offset);
|
||||
|
||||
if (++p->shift >= OFFSET_ARRAY_SIZE)
|
||||
p->shift = 0;
|
||||
|
||||
bail:
|
||||
free(addr);
|
||||
}
|
||||
|
||||
#if ENABLE_FEATURE_NTPD_SERVER
|
||||
static void
|
||||
server_dispatch(int fd)
|
||||
{
|
||||
ssize_t size;
|
||||
uint8_t version;
|
||||
double rectime;
|
||||
len_and_sockaddr *to;
|
||||
struct sockaddr *from;
|
||||
ntp_msg_t query, reply;
|
||||
|
||||
to = get_sock_lsa(G.listen_fd);
|
||||
from = xzalloc(to->len);
|
||||
|
||||
size = recv_from_to(fd, &query, sizeof(query), 0, from, &to->u.sa, to->len);
|
||||
if (size == -1)
|
||||
bb_error_msg_and_die("recv_from_to");
|
||||
if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE) {
|
||||
char *addr = xmalloc_sockaddr2dotted_noport(from);
|
||||
bb_error_msg("malformed packet received from %s", addr);
|
||||
free(addr);
|
||||
goto bail;
|
||||
}
|
||||
|
||||
rectime = gettime();
|
||||
version = (query.status & VERSION_MASK) >> 3;
|
||||
|
||||
memset(&reply, 0, sizeof(reply));
|
||||
reply.status = G.status.synced ? G.status.leap : LI_ALARM;
|
||||
reply.status |= (query.status & VERSION_MASK);
|
||||
reply.status |= ((query.status & MODE_MASK) == MODE_CLIENT) ?
|
||||
MODE_SERVER : MODE_SYM_PAS;
|
||||
reply.stratum = G.status.stratum;
|
||||
reply.ppoll = query.ppoll;
|
||||
reply.precision = G.status.precision;
|
||||
reply.rectime = d_to_lfp(rectime);
|
||||
reply.reftime = d_to_lfp(G.status.reftime);
|
||||
reply.xmttime = d_to_lfp(gettime());
|
||||
reply.orgtime = query.xmttime;
|
||||
reply.rootdelay = d_to_sfp(G.status.rootdelay);
|
||||
reply.refid = (version > 3) ? G.status.refid4 : G.status.refid;
|
||||
|
||||
/* We reply from the address packet was sent to,
|
||||
* this makes to/from look swapped here: */
|
||||
sendmsg_wrap(fd, /*from:*/ &to->u.sa, /*to:*/ from, /*addrlen:*/ to->len,
|
||||
&reply, 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.
|
||||
*/
|
||||
|
||||
enum {
|
||||
OPT_n = (1 << 0),
|
||||
OPT_g = (1 << 1),
|
||||
OPT_p = (1 << 2),
|
||||
OPT_l = (1 << 3),
|
||||
};
|
||||
|
||||
/* 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;
|
||||
|
||||
tzset();
|
||||
|
||||
if (getuid())
|
||||
bb_error_msg_and_die("need root privileges");
|
||||
|
||||
peers = NULL;
|
||||
opt_complementary = "dd:p::"; /* d: counter, p: list */
|
||||
opts = getopt32(argv,
|
||||
"ng" /* compat */
|
||||
"p:"IF_FEATURE_NTPD_SERVER("l") /* NOT compat */
|
||||
"d" /* compat */
|
||||
"46aAbLNx", /* compat, ignored */
|
||||
&peers, &G.verbose);
|
||||
#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
|
||||
if (opts & OPT_g)
|
||||
G.settime = 1;
|
||||
while (peers)
|
||||
add_peers(llist_pop(&peers));
|
||||
if (!(opts & OPT_n)) {
|
||||
logmode = LOGMODE_NONE;
|
||||
bb_daemonize(DAEMON_DEVNULL_STDIO);
|
||||
}
|
||||
|
||||
/* Set some globals */
|
||||
{
|
||||
int prec = 0;
|
||||
int b;
|
||||
#if 0
|
||||
struct timespec tp;
|
||||
/* We can use sys_clock_getres but assuming 10ms tick should be fine */
|
||||
clock_getres(CLOCK_REALTIME, &tp);
|
||||
tp.tv_sec = 0;
|
||||
tp.tv_nsec = 10000000;
|
||||
b = 1000000000 / tp.tv_nsec; /* convert to Hz */
|
||||
#else
|
||||
b = 100; /* b = 1000000000/10000000 = 100 */
|
||||
#endif
|
||||
while (b > 1)
|
||||
prec--, b >>= 1;
|
||||
G.status.precision = prec;
|
||||
}
|
||||
G.scale = 1;
|
||||
G.firstadj = 1;
|
||||
|
||||
bb_signals((1 << SIGTERM) | (1 << SIGINT), record_signo);
|
||||
bb_signals((1 << SIGPIPE) | (1 << SIGHUP), SIG_IGN);
|
||||
}
|
||||
|
||||
int ntpd_main(int argc UNUSED_PARAM, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
||||
int ntpd_main(int argc UNUSED_PARAM, char **argv)
|
||||
{
|
||||
struct globals g;
|
||||
unsigned new_cnt;
|
||||
struct pollfd *pfd;
|
||||
ntp_peer_t **idx2peer;
|
||||
|
||||
memset(&g, 0, sizeof(g));
|
||||
SET_PTR_TO_GLOBALS(&g);
|
||||
|
||||
ntp_init(argv);
|
||||
|
||||
new_cnt = g.peer_cnt;
|
||||
idx2peer = xzalloc(sizeof(void *) * new_cnt);
|
||||
#if ENABLE_FEATURE_NTPD_SERVER
|
||||
if (g.listen_fd != -1)
|
||||
new_cnt++;
|
||||
#endif
|
||||
pfd = xzalloc(sizeof(pfd[0]) * new_cnt);
|
||||
|
||||
while (!bb_got_signal) {
|
||||
llist_t *item;
|
||||
unsigned i, j, idx_peers;
|
||||
unsigned sent_cnt, trial_cnt;
|
||||
int nfds, timeout;
|
||||
time_t nextaction;
|
||||
|
||||
nextaction = time(NULL) + 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
|
||||
idx_peers = i;
|
||||
sent_cnt = trial_cnt = 0;
|
||||
for (item = g.ntp_peers; item != NULL; item = item->link) {
|
||||
ntp_peer_t *p = (ntp_peer_t *) item->data;
|
||||
|
||||
if (p->next > 0 && p->next <= time(NULL)) {
|
||||
trial_cnt++;
|
||||
if (client_query(p) == 0)
|
||||
sent_cnt++;
|
||||
}
|
||||
if (p->next > 0 && p->next < nextaction)
|
||||
nextaction = p->next;
|
||||
if (p->deadline > 0 && p->deadline < nextaction)
|
||||
nextaction = p->deadline;
|
||||
|
||||
if (p->deadline > 0 && p->deadline <= time(NULL)) {
|
||||
char *addr = xmalloc_sockaddr2dotted_noport(&p->lsa->u.sa);
|
||||
|
||||
timeout = error_interval();
|
||||
bb_info_msg("no reply from %s received in time, "
|
||||
"next query %ds", addr, timeout);
|
||||
if (p->trustlevel >= TRUSTLEVEL_BADPEER) {
|
||||
p->trustlevel /= 2;
|
||||
if (p->trustlevel < TRUSTLEVEL_BADPEER)
|
||||
bb_info_msg("peer %s now invalid", addr);
|
||||
}
|
||||
free(addr);
|
||||
|
||||
set_next(p, timeout);
|
||||
}
|
||||
|
||||
if (p->state == STATE_QUERY_SENT) {
|
||||
pfd[i].fd = p->query.fd;
|
||||
pfd[i].events = POLLIN;
|
||||
idx2peer[i - idx_peers] = p;
|
||||
i++;
|
||||
}
|
||||
}
|
||||
|
||||
if (g.settime
|
||||
&& ((trial_cnt > 0 && sent_cnt == 0) || g.peer_cnt == 0)
|
||||
) {
|
||||
settime(0); /* no good peers, don't wait */
|
||||
}
|
||||
|
||||
timeout = nextaction - time(NULL);
|
||||
if (timeout < 0)
|
||||
timeout = 0;
|
||||
|
||||
if (g.verbose)
|
||||
bb_error_msg("entering poll %u secs", timeout);
|
||||
nfds = poll(pfd, i, timeout * 1000);
|
||||
|
||||
j = 0;
|
||||
#if ENABLE_FEATURE_NTPD_SERVER
|
||||
for (; nfds > 0 && j < idx_peers; j++) {
|
||||
if (pfd[j].revents & (POLLIN|POLLERR)) {
|
||||
nfds--;
|
||||
server_dispatch(pfd[j].fd);
|
||||
}
|
||||
}
|
||||
#endif
|
||||
for (; nfds > 0 && j < i; j++) {
|
||||
if (pfd[j].revents & (POLLIN|POLLERR)) {
|
||||
nfds--;
|
||||
client_dispatch(idx2peer[j - idx_peers]);
|
||||
}
|
||||
}
|
||||
} /* while (!bb_got_signal) */
|
||||
|
||||
kill_myself_with_sig(bb_got_signal);
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user