diff options
| -rw-r--r-- | networking/ntpd_simple.c | 1005 |
1 files changed, 0 insertions, 1005 deletions
diff --git a/networking/ntpd_simple.c b/networking/ntpd_simple.c deleted file mode 100644 index 2cfbd55..0000000 --- a/networking/ntpd_simple.c +++ /dev/null @@ -1,1005 +0,0 @@ -/* - * NTP client/server, based on OpenNTPD 3.9p1 - * - * Author: Adam Tkac <vonsch@gmail.com> - * - * Licensed under GPLv2, see file LICENSE in this source tree. - */ -#include "libbb.h" -#include <netinet/ip.h> /* For IPTOS_LOWDELAY definition */ -#include <sys/resource.h> /* setpriority */ -#ifndef IPTOS_LOWDELAY -# define IPTOS_LOWDELAY 0x10 -#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)rand() % (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 = rand(); - p->p_xmt_msg.m_xmttime.fractionl = rand(); - 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_YYYYMMDDHHMMSS(buf, sizeof(buf), &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)rand() % (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; - - srand(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); -} |