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/*
*
* Connection Manager
*
* Copyright (C) 2007-2012 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <glib.h>
#include "connman.h"
struct ntp_short {
uint16_t seconds;
uint16_t fraction;
} __attribute__ ((packed));
struct ntp_time {
uint32_t seconds;
uint32_t fraction;
} __attribute__ ((packed));
struct ntp_msg {
uint8_t flags; /* Mode, version and leap indicator */
uint8_t stratum; /* Stratum details */
int8_t poll; /* Maximum interval in log2 seconds */
int8_t precision; /* Clock precision in log2 seconds */
struct ntp_short rootdelay; /* Root delay */
struct ntp_short rootdisp; /* Root dispersion */
uint32_t refid; /* Reference ID */
struct ntp_time reftime; /* Reference timestamp */
struct ntp_time orgtime; /* Origin timestamp */
struct ntp_time rectime; /* Receive timestamp */
struct ntp_time xmttime; /* Transmit timestamp */
} __attribute__ ((packed));
#define OFFSET_1900_1970 2208988800UL /* 1970 - 1900 in seconds */
#define STEPTIME_MIN_OFFSET 0.128
#define LOGTOD(a) ((a) < 0 ? 1. / (1L << -(a)) : 1L << (int)(a))
#define NTP_FLAG_LI_SHIFT 6
#define NTP_FLAG_LI_MASK 0x3
#define NTP_FLAG_LI_NOWARNING 0x0
#define NTP_FLAG_LI_ADDSECOND 0x1
#define NTP_FLAG_LI_DELSECOND 0x2
#define NTP_FLAG_LI_NOTINSYNC 0x3
#define NTP_FLAG_VN_SHIFT 3
#define NTP_FLAG_VN_MASK 0x7
#define NTP_FLAG_MD_SHIFT 0
#define NTP_FLAG_MD_MASK 0x7
#define NTP_FLAG_MD_UNSPEC 0
#define NTP_FLAG_MD_ACTIVE 1
#define NTP_FLAG_MD_PASSIVE 2
#define NTP_FLAG_MD_CLIENT 3
#define NTP_FLAG_MD_SERVER 4
#define NTP_FLAG_MD_BROADCAST 5
#define NTP_FLAG_MD_CONTROL 6
#define NTP_FLAG_MD_PRIVATE 7
#define NTP_FLAGS_ENCODE(li, vn, md) ((uint8_t)( \
(((li) & NTP_FLAG_LI_MASK) << NTP_FLAG_LI_SHIFT) | \
(((vn) & NTP_FLAG_VN_MASK) << NTP_FLAG_VN_SHIFT) | \
(((md) & NTP_FLAG_MD_MASK) << NTP_FLAG_MD_SHIFT)))
#define NTP_FLAGS_LI_DECODE(flags) ((uint8_t)(((flags) >> NTP_FLAG_LI_SHIFT) & NTP_FLAG_LI_MASK))
#define NTP_FLAGS_VN_DECODE(flags) ((uint8_t)(((flags) >> NTP_FLAG_VN_SHIFT) & NTP_FLAG_VN_MASK))
#define NTP_FLAGS_MD_DECODE(flags) ((uint8_t)(((flags) >> NTP_FLAG_MD_SHIFT) & NTP_FLAG_MD_MASK))
static guint channel_watch = 0;
static struct timeval transmit_timeval;
static int transmit_fd = 0;
static char *timeserver = NULL;
static gint poll_id = 0;
static gint timeout_id = 0;
static void send_packet(int fd, const char *server)
{
struct ntp_msg msg;
struct sockaddr_in addr;
ssize_t len;
memset(&msg, 0, sizeof(msg));
msg.flags = NTP_FLAGS_ENCODE(NTP_FLAG_LI_NOTINSYNC, 4, NTP_FLAG_MD_CLIENT);
msg.poll = 4; // min
msg.poll = 10; // max
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(123);
addr.sin_addr.s_addr = inet_addr(server);
gettimeofday(&transmit_timeval, NULL);
msg.xmttime.seconds = htonl(transmit_timeval.tv_sec + OFFSET_1900_1970);
msg.xmttime.fraction = htonl(transmit_timeval.tv_usec * 1000);
len = sendto(fd, &msg, sizeof(msg), MSG_DONTWAIT,
&addr, sizeof(addr));
if (len < 0) {
connman_error("Time request for server %s failed (%d/%s)",
server, errno, strerror(errno));
if (errno == ENETUNREACH)
__connman_timeserver_sync_next();
return;
}
if (len != sizeof(msg)) {
connman_error("Broken time request for server %s", server);
return;
}
}
static gboolean next_server(gpointer user_data)
{
if (timeserver != NULL) {
g_free(timeserver);
timeserver = NULL;
}
__connman_timeserver_sync_next();
return FALSE;
}
static gboolean next_poll(gpointer user_data)
{
if (timeserver == NULL || transmit_fd == 0)
return FALSE;
send_packet(transmit_fd, timeserver);
return FALSE;
}
static void decode_msg(void *base, size_t len, struct timeval *tv)
{
struct ntp_msg *msg = base;
double org, rec, xmt, dst;
double delay, offset;
static guint transmit_delay;
if (len < sizeof(*msg)) {
connman_error("Invalid response from time server");
return;
}
if (tv == NULL) {
connman_error("Invalid packet timestamp from time server");
return;
}
DBG("flags : 0x%02x", msg->flags);
DBG("stratum : %u", msg->stratum);
DBG("poll : %f seconds (%d)",
LOGTOD(msg->poll), msg->poll);
DBG("precision : %f seconds (%d)",
LOGTOD(msg->precision), msg->precision);
DBG("root delay : %u seconds (fraction %u)",
msg->rootdelay.seconds, msg->rootdelay.fraction);
DBG("root disp. : %u seconds (fraction %u)",
msg->rootdisp.seconds, msg->rootdisp.fraction);
DBG("reference : 0x%04x", msg->refid);
transmit_delay = LOGTOD(msg->poll);
if (msg->flags != 0x24)
return;
org = transmit_timeval.tv_sec +
(1.0e-6 * transmit_timeval.tv_usec) + OFFSET_1900_1970;
rec = ntohl(msg->rectime.seconds) +
((double) ntohl(msg->rectime.fraction) / UINT_MAX);
xmt = ntohl(msg->xmttime.seconds) +
((double) ntohl(msg->xmttime.fraction) / UINT_MAX);
dst = tv->tv_sec + (1.0e-6 * tv->tv_usec) + OFFSET_1900_1970;
DBG("org=%f rec=%f xmt=%f dst=%f", org, rec, xmt, dst);
offset = ((rec - org) + (xmt - dst)) / 2;
delay = (dst - org) - (xmt - rec);
DBG("offset=%f delay=%f", offset, delay);
/* Remove the timeout, as timeserver has responded */
if (timeout_id > 0)
g_source_remove(timeout_id);
/*
* Now poll the server every transmit_delay seconds
* for time correction.
*/
if (poll_id > 0)
g_source_remove(poll_id);
DBG("Timeserver %s, next sync in %d seconds", timeserver, transmit_delay);
poll_id = g_timeout_add_seconds(transmit_delay, next_poll, NULL);
connman_info("ntp: time slew %+.6f s", offset);
if (offset < STEPTIME_MIN_OFFSET && offset > -STEPTIME_MIN_OFFSET) {
struct timeval adj;
adj.tv_sec = (long) offset;
adj.tv_usec = (offset - adj.tv_sec) * 1000000;
DBG("adjusting time");
if (adjtime(&adj, &adj) < 0) {
connman_error("Failed to adjust time");
return;
}
DBG("%lu seconds, %lu msecs", adj.tv_sec, adj.tv_usec);
} else {
struct timeval cur;
double dtime;
gettimeofday(&cur, NULL);
dtime = offset + cur.tv_sec + 1.0e-6 * cur.tv_usec;
cur.tv_sec = (long) dtime;
cur.tv_usec = (dtime - cur.tv_sec) * 1000000;
DBG("setting time");
if (settimeofday(&cur, NULL) < 0) {
connman_error("Failed to set time");
return;
}
DBG("%lu seconds, %lu msecs", cur.tv_sec, cur.tv_usec);
}
}
static gboolean received_data(GIOChannel *channel, GIOCondition condition,
gpointer user_data)
{
unsigned char buf[128];
struct msghdr msg;
struct iovec iov;
struct cmsghdr *cmsg;
struct timeval *tv;
char aux[128];
ssize_t len;
int fd;
if (condition & (G_IO_HUP | G_IO_ERR | G_IO_NVAL)) {
connman_error("Problem with timer server channel");
channel_watch = 0;
return FALSE;
}
fd = g_io_channel_unix_get_fd(channel);
iov.iov_base = buf;
iov.iov_len = sizeof(buf);
memset(&msg, 0, sizeof(msg));
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = aux;
msg.msg_controllen = sizeof(aux);
len = recvmsg(fd, &msg, MSG_DONTWAIT);
if (len < 0)
return TRUE;
tv = NULL;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level != SOL_SOCKET)
continue;
switch (cmsg->cmsg_type) {
case SCM_TIMESTAMP:
tv = (struct timeval *) CMSG_DATA(cmsg);
break;
}
}
decode_msg(iov.iov_base, iov.iov_len, tv);
return TRUE;
}
static void start_ntp(char *server)
{
GIOChannel *channel;
struct sockaddr_in addr;
int tos = IPTOS_LOWDELAY, timestamp = 1;
if (server == NULL)
return;
DBG("server %s", server);
if (channel_watch > 0)
goto send;
transmit_fd = socket(PF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
if (transmit_fd < 0) {
connman_error("Failed to open time server socket");
return;
}
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
if (bind(transmit_fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
connman_error("Failed to bind time server socket");
close(transmit_fd);
return;
}
if (setsockopt(transmit_fd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0) {
connman_error("Failed to set type of service option");
close(transmit_fd);
return;
}
if (setsockopt(transmit_fd, SOL_SOCKET, SO_TIMESTAMP, ×tamp,
sizeof(timestamp)) < 0) {
connman_error("Failed to enable timestamp support");
close(transmit_fd);
return;
}
channel = g_io_channel_unix_new(transmit_fd);
if (channel == NULL) {
close(transmit_fd);
return;
}
g_io_channel_set_encoding(channel, NULL, NULL);
g_io_channel_set_buffered(channel, FALSE);
g_io_channel_set_close_on_unref(channel, TRUE);
channel_watch = g_io_add_watch_full(channel, G_PRIORITY_DEFAULT,
G_IO_IN | G_IO_HUP | G_IO_ERR | G_IO_NVAL,
received_data, NULL, NULL);
g_io_channel_unref(channel);
send:
send_packet(transmit_fd, server);
}
int __connman_ntp_start(char *server)
{
DBG("%s", server);
if (server == NULL)
return -EINVAL;
if (timeserver != NULL)
g_free(timeserver);
timeserver = g_strdup(server);
start_ntp(timeserver);
/*
* Add a fallback timeout , preferably short, 5 sec here,
* to fallback on the next server.
*/
timeout_id = g_timeout_add_seconds(5, next_server, NULL);
return 0;
}
void __connman_ntp_stop()
{
DBG("");
if (poll_id > 0)
g_source_remove(poll_id);
if (timeout_id > 0)
g_source_remove(timeout_id);
if (channel_watch > 0) {
g_source_remove(channel_watch);
channel_watch = 0;
transmit_fd = 0;
}
if (timeserver != NULL) {
g_free(timeserver);
timeserver = NULL;
}
}
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