08b90a9d1
Denys Vlasenko
2015-01-05
Subject
deleting unused ntpd_simple.c
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networking/ntpd_simple.c+0 -1005
| @@ -1,1005 +0,0 @@ | |
| - | /* |
| - | * NTP client/server, based on OpenNTPD 3.9p1 |
| - | * |
| - | * Author: Adam Tkac <[email protected]> |
| - | * |
| - | * 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); |
| - | } |