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authorLennart Poettering <lennart@poettering.net>2014-05-06 01:17:35 +0200
committerLennart Poettering <lennart@poettering.net>2014-05-06 01:17:35 +0200
commit678522cff0977ab4a9b3ed78fbbb8f602620eba4 (patch)
tree80f9afd9784465aac808df4ab946e9673ec24d50
parent856a5a7d769826019d86bc52ae1bc2ed7b13ad44 (diff)
timesyncd: properly handle multiple configured NTP servers and multiplei IP addresses per server name
-rw-r--r--src/timesync/timesyncd.c302
1 files 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));