ntpd: ntpd.c -> ntpd_simple.c

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 0 insertions, 1007 deletions

diff --git a/networking/ntpd.c b/networking/ntpd.c
deleted file mode 100644
index 5e48306c7..000000000
--- a/networking/ntpd.c
+++ /dev/null
@@ -1,1007 +0,0 @@
-/*
- * NTP client/server, based on OpenNTPD 3.9p1
- *
- * Author: Adam Tkac <vonsch@gmail.com>
- *
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
- */
-#include "libbb.h"
-#include <netinet/ip.h> /* For IPTOS_LOWDELAY definition */
-#ifndef IPTOS_LOWDELAY
-# define IPTOS_LOWDELAY 0x10
-#endif
-#ifndef IP_PKTINFO
-# error "Sorry, your kernel has to support IP_PKTINFO"
-#endif
-
-
-/* Sync to peers every N secs */
-#define INTERVAL_QUERY_NORMAL    30
-#define INTERVAL_QUERY_PATHETIC  60
-#define INTERVAL_QUERY_AGRESSIVE  5
-
-/* Bad if *less than* TRUSTLEVEL_BADPEER */
-#define TRUSTLEVEL_BADPEER        6
-#define TRUSTLEVEL_PATHETIC       2
-#define TRUSTLEVEL_AGRESSIVE      8
-#define TRUSTLEVEL_MAX           10
-
-#define QSCALE_OFF_MIN         0.05
-#define QSCALE_OFF_MAX         0.50
-
-/* Single query might take N secs max */
-#define QUERYTIME_MAX            15
-/* Min offset for settime at start. "man ntpd" says it's 128 ms */
-#define STEPTIME_MIN_OFFSET   0.128
-
-typedef struct {
-        uint32_t int_partl;
-        uint32_t fractionl;
-} l_fixedpt_t;
-
-typedef struct {
-        uint16_t int_parts;
-        uint16_t fractions;
-} s_fixedpt_t;
-
-enum {
-        NTP_DIGESTSIZE     = 16,
-        NTP_MSGSIZE_NOAUTH = 48,
-        NTP_MSGSIZE        = (NTP_MSGSIZE_NOAUTH + 4 + NTP_DIGESTSIZE),
-};
-
-typedef struct {
-        uint8_t     m_status;     /* status of local clock and leap info */
-        uint8_t     m_stratum;    /* stratum level */
-        uint8_t     m_ppoll;      /* poll value */
-        int8_t      m_precision_exp;
-        s_fixedpt_t m_rootdelay;
-        s_fixedpt_t m_dispersion;
-        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;
-
-enum {
-        NTP_VERSION     = 4,
-        NTP_MAXSTRATUM  = 15,
-
-        /* 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 */
-};
-
-#define OFFSET_1900_1970 2208988800UL  /* 1970 - 1900 in seconds */
-
-typedef struct {
-        double   d_offset;
-        double   d_delay;
-        //UNUSED: double d_error;
-        time_t   d_rcv_time;
-        uint32_t d_refid4;
-        uint8_t  d_leap;
-        uint8_t  d_stratum;
-        uint8_t  d_good;
-} datapoint_t;
-
-#define NUM_DATAPOINTS  8
-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): */
-        time_t           next_action_time;
-        int              p_fd;
-        uint8_t          p_datapoint_idx;
-        uint8_t          p_trustlevel;
-        double           p_xmttime;
-        datapoint_t      update;
-        datapoint_t      p_datapoint[NUM_DATAPOINTS];
-        msg_t            p_xmt_msg;
-} peer_t;
-
-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_p = (1 << 4),
-        OPT_l = (1 << 5) * ENABLE_FEATURE_NTPD_SERVER,
-};
-
-
-struct globals {
-        /* 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;
-        llist_t  *ntp_peers;
-#if ENABLE_FEATURE_NTPD_SERVER
-        int      listen_fd;
-#endif
-        unsigned verbose;
-        unsigned peer_cnt;
-        unsigned scale;
-        uint32_t refid;
-        uint32_t refid4;
-        uint8_t  synced;
-        uint8_t  leap;
-#define G_precision_exp -6
-//      int8_t   precision_exp;
-        uint8_t  stratum;
-        uint8_t  time_was_stepped;
-        uint8_t  first_adj_done;
-};
-#define G (*ptr_to_globals)
-
-static const int const_IPTOS_LOWDELAY = IPTOS_LOWDELAY;
-
-
-static void
-set_next(peer_t *p, unsigned t)
-{
-        p->next_action_time = time(NULL) + t;
-}
-
-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->p_trustlevel = TRUSTLEVEL_PATHETIC;
-        p->next_action_time = time(NULL); /* = set_next(p, 0); */
-
-        llist_add_to(&G.ntp_peers, p);
-        G.peer_cnt++;
-}
-
-static double
-gettime1900d(void)
-{
-        struct timeval tv;
-        gettimeofday(&tv, NULL); /* never fails */
-        return (tv.tv_sec + 1.0e-6 * tv.tv_usec + OFFSET_1900_1970);
-}
-
-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;
-}
-
-#if 0 //UNUSED
-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;
-}
-#endif
-
-#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 unsigned
-error_interval(void)
-{
-        unsigned interval, r;
-        interval = INTERVAL_QUERY_PATHETIC * QSCALE_OFF_MAX / QSCALE_OFF_MIN;
-        r = (unsigned)random() % (unsigned)(interval / 10);
-        return (interval + r);
-}
-
-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 int
-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, INTERVAL_QUERY_PATHETIC);
-                return -1;
-        }
-
-        if (G.verbose)
-                bb_error_msg("sent query to %s", p->p_dotted);
-        set_next(p, QUERYTIME_MAX);
-
-        return 0;
-}
-
-
-/* Time is stepped only once, when the first packet from a peer is received.
- */
-static void
-step_time_once(double offset)
-{
-        double dtime;
-        llist_t *item;
-        struct timeval tv;
-        char buf[80];
-        time_t tval;
-
-        if (G.time_was_stepped)
-                goto bail;
-        G.time_was_stepped = 1;
-
-        /* if the offset is small, don't step, slew (later) */
-        if (offset < STEPTIME_MIN_OFFSET && offset > -STEPTIME_MIN_OFFSET)
-                goto bail;
-
-        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);
-
-        for (item = G.ntp_peers; item != NULL; item = item->link) {
-                peer_t *p = (peer_t *) item->data;
-                p->next_action_time -= (time_t)offset;
-        }
-
- bail:
-        if (option_mask32 & OPT_q)
-                exit(0);
-}
-
-
-/* Time is periodically slewed when we collect enough
- * good data points.
- */
-static int
-compare_offsets(const void *aa, const void *bb)
-{
-        const peer_t *const *a = aa;
-        const peer_t *const *b = bb;
-        if ((*a)->update.d_offset < (*b)->update.d_offset)
-                return -1;
-        return ((*a)->update.d_offset > (*b)->update.d_offset);
-}
-static unsigned
-updated_scale(double offset)
-{
-        if (offset < 0)
-                offset = -offset;
-        if (offset > QSCALE_OFF_MAX)
-                return 1;
-        if (offset < QSCALE_OFF_MIN)
-                return QSCALE_OFF_MAX / QSCALE_OFF_MIN;
-        return QSCALE_OFF_MAX / offset;
-}
-static void
-slew_time(void)
-{
-        llist_t *item;
-        double offset_median;
-        struct timeval tv;
-
-        {
-                peer_t **peers = xzalloc(sizeof(peers[0]) * G.peer_cnt);
-                unsigned goodpeer_cnt = 0;
-                unsigned middle;
-
-                for (item = G.ntp_peers; item != NULL; item = item->link) {
-                        peer_t *p = (peer_t *) item->data;
-                        if (p->p_trustlevel < TRUSTLEVEL_BADPEER)
-                                continue;
-                        if (!p->update.d_good) {
-                                free(peers);
-                                return;
-                        }
-                        peers[goodpeer_cnt++] = p;
-                }
-
-                if (goodpeer_cnt == 0) {
-                        free(peers);
-                        goto clear_good;
-                }
-
-                qsort(peers, goodpeer_cnt, sizeof(peers[0]), compare_offsets);
-
-                middle = goodpeer_cnt / 2;
-                if (middle != 0 && (goodpeer_cnt & 1) == 0) {
-                        offset_median = (peers[middle-1]->update.d_offset + peers[middle]->update.d_offset) / 2;
-                        G.rootdelay = (peers[middle-1]->update.d_delay + peers[middle]->update.d_delay) / 2;
-                        G.stratum = 1 + MAX(peers[middle-1]->update.d_stratum, peers[middle]->update.d_stratum);
-                } else {
-                        offset_median = peers[middle]->update.d_offset;
-                        G.rootdelay = peers[middle]->update.d_delay;
-                        G.stratum = 1 + peers[middle]->update.d_stratum;
-                }
-                G.leap = peers[middle]->update.d_leap;
-                G.refid4 = peers[middle]->update.d_refid4;
-                G.refid =
-#if ENABLE_FEATURE_IPV6
-                        peers[middle]->p_lsa->u.sa.sa_family != AF_INET ?
-                                G.refid4 :
-#endif
-                                peers[middle]->p_lsa->u.sin.sin_addr.s_addr;
-                free(peers);
-        }
-//TODO: if (offset_median > BIG) step_time(offset_median)?
-
-        G.scale = updated_scale(offset_median);
-
-        bb_error_msg("adjusting clock by %fs, our stratum is %u, time scale %u",
-                        offset_median, G.stratum, G.scale);
-
-        errno = 0;
-        d_to_tv(offset_median, &tv);
-        if (adjtime(&tv, &tv) == -1)
-                bb_perror_msg_and_die("adjtime failed");
-        if (G.verbose >= 2)
-                bb_error_msg("old adjust: %d.%06u", (int)tv.tv_sec, (unsigned)tv.tv_usec);
-
-        if (G.first_adj_done) {
-                uint8_t synced = (tv.tv_sec == 0 && tv.tv_usec == 0);
-                if (synced != G.synced) {
-                        G.synced = synced;
-                        bb_error_msg("clock is %ssynced", synced ? "" : "un");
-                }
-        }
-        G.first_adj_done = 1;
-
-        G.reftime = gettime1900d();
-
- clear_good:
-        for (item = G.ntp_peers; item != NULL; item = item->link) {
-                peer_t *p = (peer_t *) item->data;
-                p->update.d_good = 0;
-        }
-}
-
-static void
-update_peer_data(peer_t *p)
-{
-        /* Clock filter.
-         * Find the datapoint with the lowest delay.
-         * Use that as the peer update.
-         * Invalidate it and all older ones.
-         */
-        int i;
-        int best = -1;
-        int good = 0;
-
-        for (i = 0; i < NUM_DATAPOINTS; i++) {
-                if (p->p_datapoint[i].d_good) {
-                        good++;
-                        if (best < 0 || p->p_datapoint[i].d_delay < p->p_datapoint[best].d_delay)
-                                best = i;
-                }
-        }
-
-        if (good < 8) //FIXME: was it meant to be NUM_DATAPOINTS, not 8?
-                return;
-
-        p->update = p->p_datapoint[best]; /* struct copy */
-        slew_time();
-
-        for (i = 0; i < NUM_DATAPOINTS; i++)
-                if (p->p_datapoint[i].d_rcv_time <= p->p_datapoint[best].d_rcv_time)
-                        p->p_datapoint[i].d_good = 0;
-}
-
-static unsigned
-scale_interval(unsigned requested)
-{
-        unsigned interval, r;
-        interval = requested * G.scale;
-        r = (unsigned)random() % (unsigned)(MAX(5, interval / 10));
-        return (interval + r);
-}
-static void
-recv_and_process_peer_pkt(peer_t *p)
-{
-        ssize_t     size;
-        msg_t       msg;
-        double      T1, T2, T3, T4;
-        unsigned    interval;
-        datapoint_t *datapoint;
-
-        /* 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?
-                        set_next(p, error_interval());
-                        goto 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 = error_interval();
-                bb_error_msg("reply from %s: not synced, next query in %us", p->p_dotted, interval);
-                goto close_sock;
-        }
-
-        /*
-         * 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 = gettime1900d();
-
-        datapoint = &p->p_datapoint[p->p_datapoint_idx];
-
-        datapoint->d_offset = ((T2 - T1) + (T3 - T4)) / 2;
-        datapoint->d_delay = (T4 - T1) - (T3 - T2);
-        if (datapoint->d_delay < 0) {
-                bb_error_msg("reply from %s: negative delay %f", p->p_dotted, datapoint->d_delay);
-                interval = error_interval();
-                set_next(p, interval);
-                goto close_sock;
-        }
-        //UNUSED: datapoint->d_error = (T2 - T1) - (T3 - T4);
-        datapoint->d_rcv_time = (time_t)(T4 - OFFSET_1900_1970); /* = time(NULL); */
-        datapoint->d_good = 1;
-
-        datapoint->d_leap = (msg.m_status & LI_MASK);
-        //UNUSED: datapoint->o_precision = msg.m_precision_exp;
-        //UNUSED: datapoint->o_rootdelay = sfp_to_d(msg.m_rootdelay);
-        //UNUSED: datapoint->o_rootdispersion = sfp_to_d(msg.m_dispersion);
-        //UNUSED: datapoint->d_refid = ntohl(msg.m_refid);
-        datapoint->d_refid4 = msg.m_xmttime.fractionl;
-        //UNUSED: datapoint->o_reftime = lfp_to_d(msg.m_reftime);
-        //UNUSED: datapoint->o_poll = msg.m_ppoll;
-        datapoint->d_stratum = msg.m_stratum;
-
-        if (p->p_trustlevel < TRUSTLEVEL_PATHETIC)
-                interval = scale_interval(INTERVAL_QUERY_PATHETIC);
-        else if (p->p_trustlevel < TRUSTLEVEL_AGRESSIVE)
-                interval = scale_interval(INTERVAL_QUERY_AGRESSIVE);
-        else
-                interval = scale_interval(INTERVAL_QUERY_NORMAL);
-
-        set_next(p, interval);
-
-        /* Every received reply which we do not discard increases trust */
-        if (p->p_trustlevel < TRUSTLEVEL_MAX) {
-                p->p_trustlevel++;
-                if (p->p_trustlevel == TRUSTLEVEL_BADPEER)
-                        bb_error_msg("peer %s now valid", p->p_dotted);
-        }
-
-        if (G.verbose)
-                bb_error_msg("reply from %s: offset %f delay %f, next query in %us", p->p_dotted,
-                        datapoint->d_offset, datapoint->d_delay, interval);
-
-        update_peer_data(p);
-//TODO: do it after all peers had a chance to return at least one reply?
-        step_time_once(datapoint->d_offset);
-
-        p->p_datapoint_idx++;
-        if (p->p_datapoint_idx >= NUM_DATAPOINTS)
-                p->p_datapoint_idx = 0;
-
- close_sock:
-        /* 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 void
-recv_and_process_client_pkt(void /*int fd*/)
-{
-        ssize_t          size;
-        uint8_t          version;
-        double           rectime;
-        len_and_sockaddr *to;
-        struct sockaddr  *from;
-        msg_t            msg;
-        uint8_t          query_status;
-        uint8_t          query_ppoll;
-        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_ppoll = msg.m_ppoll;
-        query_xmttime = msg.m_xmttime;
-
-        /* Build a reply packet */
-        memset(&msg, 0, sizeof(msg));
-        msg.m_status = G.synced ? G.leap : 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 = query_ppoll;
-        msg.m_precision_exp = G_precision_exp;
-        rectime = gettime1900d();
-        msg.m_xmttime = msg.m_rectime = d_to_lfp(rectime);
-        msg.m_reftime = d_to_lfp(G.reftime);
-        //msg.m_xmttime = d_to_lfp(gettime1900d()); // = msg.m_rectime
-        msg.m_orgtime = query_xmttime;
-        msg.m_rootdelay = d_to_sfp(G.rootdelay);
-        version = (query_status & VERSION_MASK); /* ... >> VERSION_SHIFT - done below instead */
-        msg.m_refid = (version > (3 << VERSION_SHIFT)) ? G.refid4 : G.refid;
-
-        /* 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(bb_msg_you_must_be_root);
-
-        peers = NULL;
-        opt_complementary = "dd:p::"; /* d: counter, p: list */
-        opts = getopt32(argv,
-                        "nqNx" /* compat */
-                        "p:"IF_FEATURE_NTPD_SERVER("l") /* NOT compat */
-                        "d" /* compat */
-                        "46aAbgL", /* compat, ignored */
-                        &peers, &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;
-        while (peers)
-                add_peers(llist_pop(&peers));
-        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);
-
-        /* Set some globals */
-#if 0
-        /* With constant b = 100, G.precision_exp is also constant -6.
-         * Uncomment this and you'll see */
-        {
-                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.precision_exp = prec;
-                bb_error_msg("G.precision_exp:%d", prec); /* -6 */
-        }
-#endif
-        G.scale = 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;
-        struct pollfd *pfd;
-        peer_t **idx2peer;
-
-        memset(&g, 0, sizeof(g));
-        SET_PTR_TO_GLOBALS(&g);
-
-        ntp_init(argv);
-
-        {
-                /* if ENABLE_FEATURE_NTPD_SERVER, + 1 for listen_fd: */
-                unsigned cnt = g.peer_cnt + ENABLE_FEATURE_NTPD_SERVER;
-                idx2peer = xzalloc(sizeof(idx2peer[0]) * cnt);
-                pfd = xzalloc(sizeof(pfd[0]) * cnt);
-        }
-
-        while (!bb_got_signal) {
-                llist_t *item;
-                unsigned i, j;
-                unsigned sent_cnt, trial_cnt;
-                int nfds, timeout;
-                time_t cur_time, nextaction;
-
-                /* Nothing between here and poll() blocks for any significant time */
-
-                cur_time = time(NULL);
-                nextaction = 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 */
-                sent_cnt = trial_cnt = 0;
-                for (item = g.ntp_peers; item != NULL; item = item->link) {
-                        peer_t *p = (peer_t *) item->data;
-
-                        /* Overflow-safe "if (p->next_action_time <= cur_time) ..." */
-                        if ((int)(cur_time - p->next_action_time) >= 0) {
-                                if (p->p_fd == -1) {
-                                        /* Time to send new req */
-                                        trial_cnt++;
-                                        if (send_query_to_peer(p) == 0)
-                                                sent_cnt++;
-                                } else {
-                                        /* Timed out waiting for reply */
-                                        close(p->p_fd);
-                                        p->p_fd = -1;
-                                        timeout = error_interval();
-                                        bb_error_msg("timed out waiting for %s, "
-                                                        "next query in %us", p->p_dotted, timeout);
-                                        if (p->p_trustlevel >= TRUSTLEVEL_BADPEER) {
-                                                p->p_trustlevel /= 2;
-                                                if (p->p_trustlevel < TRUSTLEVEL_BADPEER)
-                                                        bb_error_msg("peer %s now invalid", p->p_dotted);
-                                        }
-                                        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++;
-                        }
-                }
-
-                if ((trial_cnt > 0 && sent_cnt == 0) || g.peer_cnt == 0)
-                        step_time_once(0); /* no good peers, don't wait */
-
-                timeout = nextaction - cur_time;
-                if (timeout < 1)
-                        timeout = 1;
-
-                /* Here we may block */
-                if (g.verbose >= 2)
-                        bb_error_msg("poll %us, sockets:%u", timeout, i);
-                nfds = poll(pfd, i, timeout * 1000);
-                if (nfds <= 0)
-                        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*/);
-                        }
-                        j = 1;
-                }
-#endif
-                for (; nfds != 0 && j < i; j++) {
-                        if (pfd[j].revents /* & (POLLIN|POLLERR)*/) {
-                                nfds--;
-                                recv_and_process_peer_pkt(idx2peer[j]);
-                        }
-                }
-        } /* while (!bb_got_signal) */
-
-        kill_myself_with_sig(bb_got_signal);
-}