X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Ftimesync%2Ftimesyncd-manager.c;h=3ae01eb8fc934643bc7592c3f70599b1d1393b3e;hp=60f39c638d3bdd715cf6ca0cb7a720a392b19803;hb=69f0081748fb4be1b7b772815e5c4202cdb88d3d;hpb=07610e108e2d3f046da683a3a69c4d5cccd2cf8e diff --git a/src/timesync/timesyncd-manager.c b/src/timesync/timesyncd-manager.c index 60f39c638..3ae01eb8f 100644 --- a/src/timesync/timesyncd-manager.c +++ b/src/timesync/timesyncd-manager.c @@ -54,8 +54,7 @@ #include "mkdir.h" #include "timesyncd-conf.h" #include "timesyncd-manager.h" - -#define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1) +#include "time-util.h" #ifndef ADJ_SETOFFSET #define ADJ_SETOFFSET 0x0100 /* add 'time' to current time */ @@ -89,6 +88,12 @@ #define NTP_FIELD_MODE(f) ((f) & 7) #define NTP_FIELD(l, v, m) (((l) << 6) | ((v) << 3) | (m)) +/* Maximum acceptable root distance in seconds. */ +#define NTP_MAX_ROOT_DISTANCE 5.0 + +/* Maximum number of missed replies before selecting another source. */ +#define NTP_MAX_MISSED_REPLIES 2 + /* * "NTP timestamps are represented as a 64-bit unsigned fixed-point number, * in seconds relative to 0h on 1 January 1900." @@ -128,6 +133,10 @@ struct ntp_msg { static int manager_arm_timer(Manager *m, usec_t next); static int manager_clock_watch_setup(Manager *m); +static double ntp_ts_short_to_d(const struct ntp_ts_short *ts) { + return be16toh(ts->sec) + (be16toh(ts->frac) / 65536.0); +} + static double ntp_ts_to_d(const struct ntp_ts *ts) { return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX); } @@ -136,10 +145,6 @@ static double ts_to_d(const struct timespec *ts) { return ts->tv_sec + (1.0e-9 * ts->tv_nsec); } -static double tv_to_d(const struct timeval *tv) { - return tv->tv_sec + (1.0e-6 * tv->tv_usec); -} - static double square(double d) { return d * d; } @@ -216,15 +221,18 @@ static int manager_send_request(Manager *m) { return r; } - r = sd_event_add_time( - m->event, - &m->event_timeout, - clock_boottime_or_monotonic(), - now(clock_boottime_or_monotonic()) + TIMEOUT_USEC, 0, - manager_timeout, m); - if (r < 0) { - log_error("Failed to arm timeout timer: %s", strerror(-r)); - return r; + m->missed_replies++; + if (m->missed_replies > NTP_MAX_MISSED_REPLIES) { + r = sd_event_add_time( + m->event, + &m->event_timeout, + clock_boottime_or_monotonic(), + now(clock_boottime_or_monotonic()) + TIMEOUT_USEC, 0, + manager_timeout, m); + if (r < 0) { + log_error("Failed to arm timeout timer: %s", strerror(-r)); + return r; + } } return 0; @@ -500,11 +508,11 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re .msg_namelen = sizeof(server_addr), }; struct cmsghdr *cmsg; - struct timespec now_ts; - struct timeval *recv_time; + struct timespec *recv_time; ssize_t len; double origin, receive, trans, dest; double delay, offset; + double root_distance; bool spike; int leap_sec; int r; @@ -544,8 +552,8 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re continue; switch (cmsg->cmsg_type) { - case SCM_TIMESTAMP: - recv_time = (struct timeval *) CMSG_DATA(cmsg); + case SCM_TIMESTAMPNS: + recv_time = (struct timespec *) CMSG_DATA(cmsg); break; } } @@ -559,6 +567,8 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re return 0; } + m->missed_replies = 0; + /* check our "time cookie" (we just stored nanoseconds in the fraction field) */ if (be32toh(ntpmsg.origin_time.sec) != m->trans_time.tv_sec + OFFSET_1900_1970 || be32toh(ntpmsg.origin_time.frac) != m->trans_time.tv_nsec) { @@ -590,6 +600,12 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re return manager_connect(m); } + root_distance = ntp_ts_short_to_d(&ntpmsg.root_delay) / 2 + ntp_ts_short_to_d(&ntpmsg.root_dispersion); + if (root_distance > NTP_MAX_ROOT_DISTANCE) { + log_debug("Server has too large root distance. Disconnecting."); + return manager_connect(m); + } + /* valid packet */ m->pending = false; m->retry_interval = 0; @@ -613,11 +629,10 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re * The round-trip delay, d, and system clock offset, t, are defined as: * d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2" */ - assert_se(clock_gettime(clock_boottime_or_monotonic(), &now_ts) >= 0); - origin = tv_to_d(recv_time) - (ts_to_d(&now_ts) - ts_to_d(&m->trans_time_mon)) + OFFSET_1900_1970; + origin = ts_to_d(&m->trans_time) + OFFSET_1900_1970; receive = ntp_ts_to_d(&ntpmsg.recv_time); trans = ntp_ts_to_d(&ntpmsg.trans_time); - dest = tv_to_d(recv_time) + OFFSET_1900_1970; + dest = ts_to_d(recv_time) + OFFSET_1900_1970; offset = ((receive - origin) + (trans - dest)) / 2; delay = (dest - origin) - (trans - receive); @@ -632,6 +647,7 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re " mode : %u\n" " stratum : %u\n" " precision : %.6f sec (%d)\n" + " root distance: %.6f sec\n" " reference : %.4s\n" " origin : %.3f\n" " receive : %.3f\n" @@ -647,6 +663,7 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re NTP_FIELD_MODE(ntpmsg.field), ntpmsg.stratum, exp2(ntpmsg.precision), ntpmsg.precision, + root_distance, ntpmsg.stratum == 1 ? ntpmsg.refid : "n/a", origin - OFFSET_1900_1970, receive - OFFSET_1900_1970, @@ -699,11 +716,11 @@ static int manager_listen_setup(Manager *m) { if (r < 0) return -errno; - r = setsockopt(m->server_socket, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on)); + r = setsockopt(m->server_socket, SOL_SOCKET, SO_TIMESTAMPNS, &on, sizeof(on)); if (r < 0) return -errno; - setsockopt(m->server_socket, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)); + (void) setsockopt(m->server_socket, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)); return sd_event_add_io(m->event, &m->event_receive, m->server_socket, EPOLLIN, manager_receive_response, m); } @@ -716,7 +733,9 @@ static int manager_begin(Manager *m) { assert_return(m->current_server_name, -EHOSTUNREACH); assert_return(m->current_server_address, -EHOSTUNREACH); - m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; + m->missed_replies = NTP_MAX_MISSED_REPLIES; + if (m->poll_interval_usec == 0) + m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; server_address_pretty(m->current_server_address, &pretty); log_info("Using NTP server %s (%s).", strna(pretty), m->current_server_name->string); @@ -756,8 +775,11 @@ void manager_set_server_address(Manager *m, ServerAddress *a) { if (m->current_server_address == a) return; - m->current_server_name = a ? a->name : NULL; m->current_server_address = a; + /* If a is NULL, we are just clearing the address, without + * changing the name. Keep the existing name in that case. */ + if (a) + m->current_server_name = a->name; manager_disconnect(m); @@ -862,6 +884,7 @@ int manager_connect(Manager *m) { manager_set_server_name(m, m->current_server_name->names_next); else { ServerName *f; + bool restart = true; /* Our current server name list is exhausted, * let's find the next one to iterate. First @@ -878,6 +901,8 @@ int manager_connect(Manager *m) { f = m->link_servers; if (!f) f = m->system_servers; + else + restart = false; } if (!f) @@ -889,6 +914,25 @@ int manager_connect(Manager *m) { return 0; } + if (restart && !m->exhausted_servers && m->poll_interval_usec) { + log_debug("Waiting after exhausting servers."); + r = sd_event_add_time(m->event, &m->event_retry, clock_boottime_or_monotonic(), now(clock_boottime_or_monotonic()) + m->poll_interval_usec, 0, manager_retry_connect, m); + if (r < 0) { + log_error("Failed to create retry timer: %s", strerror(-r)); + return r; + } + + m->exhausted_servers = true; + + /* Increase the polling interval */ + if (m->poll_interval_usec < NTP_POLL_INTERVAL_MAX_SEC * USEC_PER_SEC) + m->poll_interval_usec *= 2; + + return 0; + } + + m->exhausted_servers = false; + manager_set_server_name(m, f); } @@ -1029,7 +1073,7 @@ static int manager_network_event_handler(sd_event_source *s, int fd, uint32_t re online = network_is_online(); /* check if the client is currently connected */ - connected = m->server_socket >= 0 || m->resolve_query; + connected = m->server_socket >= 0 || m->resolve_query || m->exhausted_servers; if (connected && !online) { log_info("No network connectivity, watching for changes.");