From 678522cff0977ab4a9b3ed78fbbb8f602620eba4 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 6 May 2014 01:17:35 +0200 Subject: timesyncd: properly handle multiple configured NTP servers and multiplei IP addresses per server name --- src/timesync/timesyncd.c | 302 ++++++++++++++++++++++++++++++++++++----------- 1 file changed, 232 insertions(+), 70 deletions(-) diff --git a/src/timesync/timesyncd.c b/src/timesync/timesyncd.c index a66d1e46c0..6c886972f8 100644 --- a/src/timesync/timesyncd.c +++ b/src/timesync/timesyncd.c @@ -38,6 +38,7 @@ #include "sparse-endian.h" #include "log.h" #include "socket-util.h" +#include "list.h" #include "sd-event.h" #include "sd-resolve.h" #include "sd-daemon.h" @@ -107,16 +108,32 @@ struct ntp_msg { } _packed_; typedef struct Manager Manager; +typedef struct ServerAddress ServerAddress; +typedef struct ServerName ServerName; + +struct ServerAddress { + union sockaddr_union sockaddr; + socklen_t socklen; + LIST_FIELDS(ServerAddress, addresses); +}; + +struct ServerName { + char *string; + LIST_HEAD(ServerAddress, addresses); + LIST_FIELDS(ServerName, names); +}; + struct Manager { sd_event *event; sd_resolve *resolve; + LIST_HEAD(ServerName, servers); + /* peer */ sd_resolve_query *resolve_query; sd_event_source *event_receive; - char *server; - union sockaddr_union server_addr; - socklen_t server_addr_length; + ServerName *current_server_name; + ServerAddress *current_server_address; int server_socket; uint64_t packet_count; @@ -157,6 +174,8 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free); static int manager_arm_timer(Manager *m, usec_t next); static int manager_clock_watch_setup(Manager *m); +static int manager_connect(Manager *m); +static void manager_disconnect(Manager *m); static double ntp_ts_to_d(const struct ntp_ts *ts) { return be32toh(ts->sec) + ((double)be32toh(ts->frac) / UINT_MAX); @@ -175,6 +194,7 @@ static double square(double d) { } static int manager_send_request(Manager *m) { + _cleanup_free_ char *pretty = NULL; struct ntp_msg ntpmsg = { /* * "The client initializes the NTP message header, sends the request @@ -186,6 +206,11 @@ static int manager_send_request(Manager *m) { .field = NTP_FIELD(0, 4, NTP_MODE_CLIENT), }; ssize_t len; + int r; + + assert(m); + assert(m->current_server_name); + assert(m->current_server_address); /* * Set transmit timestamp, remember it; the server will send that back @@ -200,12 +225,18 @@ static int manager_send_request(Manager *m) { ntpmsg.trans_time.sec = htobe32(m->trans_time.tv_sec + OFFSET_1900_1970); ntpmsg.trans_time.frac = htobe32(m->trans_time.tv_nsec); - len = sendto(m->server_socket, &ntpmsg, sizeof(ntpmsg), MSG_DONTWAIT, &m->server_addr.sa, m->server_addr_length); + r = sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty); + if (r < 0) { + log_error("Failed to format sockaddr: %s", strerror(-r)); + return r; + } + + len = sendto(m->server_socket, &ntpmsg, sizeof(ntpmsg), MSG_DONTWAIT, &m->current_server_address->sockaddr.sa, m->current_server_address->socklen); if (len == sizeof(ntpmsg)) { m->pending = true; - log_debug("Sent NTP request to: %s", m->server); + log_debug("Sent NTP request to %s (%s)", pretty, m->current_server_name->string); } else - log_debug("Sending NTP request to %s failed: %m", m->server); + log_debug("Sending NTP request to %s (%s) failed: %m", pretty, m->current_server_name->string); /* re-arm timer with incresing timeout, in case the packets never arrive back */ if (m->retry_interval > 0) { @@ -214,7 +245,13 @@ static int manager_send_request(Manager *m) { } else m->retry_interval = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; - return manager_arm_timer(m, m->retry_interval); + r = manager_arm_timer(m, m->retry_interval); + if (r < 0) { + log_error("Failed to rearm timer: %s", strerror(-r)); + return r; + } + + return 0; } static int manager_timer(sd_event_source *source, usec_t usec, void *userdata) { @@ -471,6 +508,7 @@ static bool sockaddr_equal(union sockaddr_union *a, union sockaddr_union *b) { } static int manager_receive_response(sd_event_source *source, int fd, uint32_t revents, void *userdata) { + _cleanup_free_ char *pretty = NULL; Manager *m = userdata; struct ntp_msg ntpmsg; @@ -501,9 +539,12 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re int leap_sec; int r; + assert(source); + assert(m); + if (revents & (EPOLLHUP|EPOLLERR)) { - log_debug("Server connection returned error."); - return -ENOTCONN; + log_warning("Server connection returned error."); + return manager_connect(m); } len = recvmsg(fd, &msghdr, MSG_DONTWAIT); @@ -511,18 +552,20 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re if (errno == EAGAIN) return 0; - log_debug("Error receiving message. Disconnecting."); - return -errno; + log_warning("Error receiving message. Disconnecting."); + return manager_connect(m); } if (iov.iov_len < sizeof(struct ntp_msg)) { - log_debug("Invalid response from server. Disconnecting."); - return -EINVAL; + log_warning("Invalid response from server. Disconnecting."); + return manager_connect(m); } - if (!sockaddr_equal(&server_addr, &m->server_addr)) { - log_debug("Response from unknown server. Disconnecting."); - return -EINVAL; + if (!m->current_server_name || + !m->current_server_address || + !sockaddr_equal(&server_addr, &m->current_server_address->sockaddr)) { + log_debug("Response from unknown server."); + return 0; } recv_time = NULL; @@ -537,7 +580,7 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re } } if (!recv_time) { - log_debug("Invalid packet timestamp. Disconnecting."); + log_error("Invalid packet timestamp."); return -EINVAL; } @@ -555,17 +598,17 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re if (NTP_FIELD_LEAP(ntpmsg.field) == NTP_LEAP_NOTINSYNC) { log_debug("Server is not synchronized. Disconnecting."); - return -EINVAL; + return manager_connect(m); } if (NTP_FIELD_VERSION(ntpmsg.field) != 4) { log_debug("Response NTPv%d. Disconnecting.", NTP_FIELD_VERSION(ntpmsg.field)); - return -EINVAL; + return manager_connect(m); } if (NTP_FIELD_MODE(ntpmsg.field) != NTP_MODE_SERVER) { log_debug("Unsupported mode %d. Disconnecting.", NTP_FIELD_MODE(ntpmsg.field)); - return -EINVAL; + return manager_connect(m); } /* valid packet */ @@ -641,11 +684,23 @@ static int manager_receive_response(sd_event_source *source, int fd, uint32_t re log_error("Failed to call clock_adjtime(): %m"); } - log_info("%s: interval/delta/delay/jitter/drift %llus/%+.3fs/%.3fs/%.3fs/%+ippm%s", - m->server, m->poll_interval_usec / USEC_PER_SEC, offset, delay, m->samples_jitter, m->drift_ppm, + r = sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty); + if (r < 0) { + log_error("Failed to format socket address: %s", strerror(-r)); + return r; + } + + log_info("%s (%s): interval/delta/delay/jitter/drift %llus/%+.3fs/%.3fs/%.3fs/%+ippm%s", + pretty, m->current_server_name->string, m->poll_interval_usec / USEC_PER_SEC, offset, delay, m->samples_jitter, m->drift_ppm, spike ? " (ignored)" : ""); - return manager_arm_timer(m, m->poll_interval_usec); + r = manager_arm_timer(m, m->poll_interval_usec); + if (r < 0) { + log_error("Failed to rearm timer: %s", strerror(-r)); + return r; + } + + return 0; } static int manager_listen_setup(Manager *m) { @@ -658,14 +713,15 @@ static int manager_listen_setup(Manager *m) { assert(m->server_socket < 0); assert(!m->event_receive); + assert(m->current_server_address); - addr.sa.sa_family = m->server_addr.sa.sa_family; + addr.sa.sa_family = m->current_server_address->sockaddr.sa.sa_family; m->server_socket = socket(addr.sa.sa_family, SOCK_DGRAM | SOCK_CLOEXEC, 0); if (m->server_socket < 0) return -errno; - r = bind(m->server_socket, &addr.sa, m->server_addr_length); + r = bind(m->server_socket, &addr.sa, m->current_server_address->socklen); if (r < 0) return -errno; @@ -678,42 +734,24 @@ static int manager_listen_setup(Manager *m) { return sd_event_add_io(m->event, &m->event_receive, m->server_socket, EPOLLIN, manager_receive_response, m); } -static int manager_resolve_handler(sd_resolve_query *q, int ret, const struct addrinfo *ai, void *userdata) { +static int manager_begin(Manager *m) { _cleanup_free_ char *pretty = NULL; - Manager *m = userdata; int r; - assert(q); assert(m); + assert_return(m->current_server_name, -EHOSTUNREACH); + assert_return(m->current_server_address, -EHOSTUNREACH); - m->resolve_query = sd_resolve_query_unref(m->resolve_query); - - if (ret != 0) { - log_error("Failed to resolve %s: %s", m->server, gai_strerror(ret)); - return -EHOSTUNREACH; - } - - assert(ai); - assert(ai->ai_addr); - assert(ai->ai_addrlen >= offsetof(struct sockaddr, sa_data)); - assert(ai->ai_addrlen <= sizeof(union sockaddr_union)); - - if (!IN_SET(ai->ai_addr->sa_family, AF_INET, AF_INET6)) { - log_warning("Failed to find IP address for %s", m->server); - return -EHOSTUNREACH; - } - - memcpy(&m->server_addr, ai->ai_addr, ai->ai_addrlen); - m->server_addr_length = ai->ai_addrlen; + m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; - r = sockaddr_pretty(&m->server_addr.sa, m->server_addr_length, true, &pretty); + r = sockaddr_pretty(&m->current_server_address->sockaddr.sa, m->current_server_address->socklen, true, &pretty); if (r < 0) { - log_warning("Failed to decode address of %s: %s", m->server, strerror(-r)); + log_warning("Failed to decode address of %s: %s", m->current_server_name->string, strerror(-r)); return r; } - log_debug("Connecting to NTP server %s.", pretty); - sd_notifyf(false, "STATUS=Using Time Server %s", pretty); + log_debug("Connecting to NTP server %s (%s).", pretty, m->current_server_name->string); + sd_notifyf(false, "STATUS=Using Time Server %s (%s)", pretty, m->current_server_name->string); r = manager_listen_setup(m); if (r < 0) { @@ -722,34 +760,159 @@ static int manager_resolve_handler(sd_resolve_query *q, int ret, const struct ad } r = manager_clock_watch_setup(m); - if (r < 0) { - log_warning("Failed to setup clock watch: %s", strerror(-r)); + if (r < 0) return r; - } return manager_send_request(m); } -static int manager_connect(Manager *m, const char *server) { +static void server_name_flush_addresses(ServerName *n) { + ServerAddress *a; + + assert(n); + + while ((a = n->addresses)) { + LIST_REMOVE(addresses, n->addresses, a); + free(a); + } +} + +static void manager_flush_names(Manager *m) { + ServerName *n; + + assert(m); + + while ((n = m->servers)) { + LIST_REMOVE(names, m->servers, n); + free(n->string); + server_name_flush_addresses(n); + free(n); + } +} + +static int manager_resolve_handler(sd_resolve_query *q, int ret, const struct addrinfo *ai, void *userdata) { + Manager *m = userdata; + ServerAddress *a, *last = NULL; + + assert(q); + assert(m); + assert(m->current_server_name); + + m->resolve_query = sd_resolve_query_unref(m->resolve_query); + + if (ret != 0) { + log_error("Failed to resolve %s: %s", m->current_server_name->string, gai_strerror(ret)); + + /* Try next host */ + return manager_connect(m); + } + + server_name_flush_addresses(m->current_server_name); + + for (; ai; ai = ai->ai_next) { + _cleanup_free_ char *pretty = NULL; + + assert(ai->ai_addr); + assert(ai->ai_addrlen >= offsetof(struct sockaddr, sa_data)); + assert(ai->ai_addrlen <= sizeof(union sockaddr_union)); + + if (!IN_SET(ai->ai_addr->sa_family, AF_INET, AF_INET6)) { + log_warning("Unsuitable address protocol for %s", m->current_server_name->string); + continue; + } + + a = new0(ServerAddress, 1); + if (!a) + return log_oom(); + + memcpy(&a->sockaddr, ai->ai_addr, ai->ai_addrlen); + a->socklen = ai->ai_addrlen; + + LIST_INSERT_AFTER(addresses, m->current_server_name->addresses, last, a); + last = a; + + sockaddr_pretty(&a->sockaddr.sa, a->socklen, true, &pretty); + log_debug("Found address %s for %s.", pretty, m->current_server_name->string); + } + + if (!m->current_server_name->addresses) { + log_error("Failed to find suitable address for host %s.", m->current_server_name->string); + + /* Try next host */ + return manager_connect(m); + } + + m->current_server_address = m->current_server_name->addresses; + + return manager_begin(m); +} + +static int manager_connect(Manager *m) { struct addrinfo hints = { .ai_flags = AI_NUMERICSERV|AI_ADDRCONFIG, .ai_socktype = SOCK_DGRAM, }; + int r; assert(m); - assert(server); - if (m->server) - return -EBUSY; + manager_disconnect(m); + + /* If we already are operating on some address, switch to the + * next one. */ + if (m->current_server_address && m->current_server_address->addresses_next) + m->current_server_address = m->current_server_address->addresses_next; + else { + /* Hmm, we are through all addresses, let's look for the next host instead */ + m->current_server_address = NULL; + + if (m->current_server_name && m->current_server_name->names_next) + m->current_server_name = m->current_server_name->names_next; + else { + if (!m->servers) { + m->current_server_name = NULL; + log_debug("No server found."); + return 0; + } + + m->current_server_name = m->servers; + } + + r = sd_resolve_getaddrinfo(m->resolve, &m->resolve_query, m->current_server_name->string, "123", &hints, manager_resolve_handler, m); + if (r < 0) { + log_error("Failed to create resolver: %s", strerror(-r)); + return r; + } + + return 1; + } + + r = manager_begin(m); + if (r < 0) + return r; + + return 1; +} + +static int manager_add_server(Manager *m, const char *server) { + ServerName *n; + + assert(m); + assert(server); - m->server = strdup(server); - if (!m->server) + n = new0(ServerName, 1); + if (!n) return -ENOMEM; - m->poll_interval_usec = NTP_POLL_INTERVAL_MIN_SEC * USEC_PER_SEC; + n->string = strdup(server); + if (!n->string) { + free(n); + return -ENOMEM; + } - return sd_resolve_getaddrinfo(m->resolve, &m->resolve_query, m->server, "123", &hints, manager_resolve_handler, m); + LIST_PREPEND(names, m->servers, n); + return 0; } static void manager_disconnect(Manager *m) { @@ -762,12 +925,6 @@ static void manager_disconnect(Manager *m) { m->event_receive = sd_event_source_unref(m->event_receive); m->server_socket = safe_close(m->server_socket); - zero(m->server_addr); - m->server_addr_length = 0; - - free(m->server); - m->server = NULL; - m->event_clock_watch = sd_event_source_unref(m->event_clock_watch); m->clock_watch_fd = safe_close(m->clock_watch_fd); } @@ -812,6 +969,7 @@ static void manager_free(Manager *m) { return; manager_disconnect(m); + manager_flush_names(m); sd_event_source_unref(m->sigint); sd_event_source_unref(m->sigterm); @@ -840,12 +998,16 @@ int main(int argc, char *argv[]) { sd_notify(false, "READY=1"); - r = manager_connect(m, "time1.google.com"); + r = manager_add_server(m, "time1.google.com"); if (r < 0) { - log_error("Failed to initiate connection: %s", strerror(-r)); + log_error("Failed to add server: %s", strerror(-r)); goto out; } + r = manager_connect(m); + if (r < 0) + goto out; + r = sd_event_loop(m->event); if (r < 0) { log_error("Failed to run event loop: %s", strerror(-r)); -- cgit v1.2.3-54-g00ecf