faraphel/chrony
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

ntp: add support for new Linux timestamping options

Browse source 
New timestamping options may be available in kernel 4.13. They can be
used to get the index of the interface which timestamped incoming packet
together with its length at layer 2, enable simultaneous SW and HW TX
timestamping, and enable a new RX filter for NTP packets.
This commit is contained in:
Miroslav Lichvar 2017-06-06 17:07:45 +02:00
parent b799cfd1c4
commit 934d4047f1
2 changed files with 74 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
configure vendored
View file

@ -660,6 +660,17 @@ if [ $feat_timestamping = "1" ] && [ $try_timestamping = "1" ] &&
then
add_def HAVE_LINUX_TIMESTAMPING
EXTRA_OBJECTS="$EXTRA_OBJECTS hwclock.o ntp_io_linux.o"
if test_code 'other timestamping options' \
'sys/types.h sys/socket.h linux/net_tstamp.h' '' '' '
struct scm_ts_pktinfo pktinfo;
pktinfo.if_index = pktinfo.pkt_length = 0;
return pktinfo.if_index + pktinfo.pkt_length + HWTSTAMP_FILTER_NTP_ALL +
SOF_TIMESTAMPING_OPT_PKTINFO + SOF_TIMESTAMPING_OPT_TX_SWHW;'; then
add_def HAVE_LINUX_TIMESTAMPING_RXFILTER_NTP 1
add_def HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO 1
add_def HAVE_LINUX_TIMESTAMPING_OPT_TX_SWHW 1
fi
fi
timepps_h=""

68
ntp_io_linux.c
View file

@ -152,6 +152,11 @@ add_interface(CNF_HwTsInterface *conf_iface)
ts_config.flags = 0;
ts_config.tx_type = HWTSTAMP_TX_ON;
#ifdef HAVE_LINUX_TIMESTAMPING_RXFILTER_NTP
if (ts_info.rx_filters & (1 << HWTSTAMP_FILTER_NTP_ALL))
ts_config.rx_filter = HWTSTAMP_FILTER_NTP_ALL;
else
#endif
ts_config.rx_filter = HWTSTAMP_FILTER_ALL;
req.ifr_data = (char *)&ts_config;
@ -252,6 +257,29 @@ update_interface_speed(struct Interface *iface)
/* ================================================== */
#if defined(HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO) || defined(HAVE_LINUX_TIMESTAMPING_OPT_TX_SWHW)
static int
check_timestamping_option(int option)
{
int sock_fd;
sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
if (sock_fd < 0)
return 0;
if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMPING, &option, sizeof (option)) < 0) {
DEBUG_LOG("Could not enable timestamping option %x", option);
close(sock_fd);
return 0;
}
close(sock_fd);
return 1;
}
#endif
/* ================================================== */
void
NIO_Linux_Initialise(void)
{
@ -286,6 +314,14 @@ NIO_Linux_Initialise(void)
if (hwts) {
ts_flags |= SOF_TIMESTAMPING_RAW_HARDWARE | SOF_TIMESTAMPING_RX_HARDWARE;
ts_tx_flags |= SOF_TIMESTAMPING_TX_HARDWARE;
#ifdef HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO
if (check_timestamping_option(SOF_TIMESTAMPING_OPT_PKTINFO))
ts_flags |= SOF_TIMESTAMPING_OPT_PKTINFO;
#endif
#ifdef HAVE_LINUX_TIMESTAMPING_OPT_TX_SWHW
if (check_timestamping_option(SOF_TIMESTAMPING_OPT_TX_SWHW))
ts_flags |= SOF_TIMESTAMPING_OPT_TX_SWHW;
#endif
}
/* Enable IP_PKTINFO in messages looped back to the error queue */
@ -370,11 +406,11 @@ get_interface(int if_index)
static void
process_hw_timestamp(struct Interface *iface, struct timespec *hw_ts,
NTP_Local_Timestamp *local_ts, int rx_ntp_length, int family)
NTP_Local_Timestamp *local_ts, int rx_ntp_length, int family,
int l2_length)
{
struct timespec sample_phc_ts, sample_sys_ts, sample_local_ts, ts;
double rx_correction, ts_delay, phc_err, local_err;
int l2_length;
if (HCL_NeedsNewSample(iface->clock, &local_ts->ts)) {
if (!SYS_Linux_GetPHCSample(iface->phc_fd, iface->phc_nocrossts, iface->precision,
@ -391,10 +427,11 @@ process_hw_timestamp(struct Interface *iface, struct timespec *hw_ts,
/* We need to transpose RX timestamps as hardware timestamps are normally
preamble timestamps and RX timestamps in NTP are supposed to be trailer
timestamps. Without raw sockets we don't know the length of the packet
at layer 2, so we make an assumption that UDP data start at the same
position as in the last transmitted packet which had a HW TX timestamp. */
timestamps. If we don't know the length of the packet at layer 2, we
make an assumption that UDP data start at the same position as in the
last transmitted packet which had a HW TX timestamp. */
if (rx_ntp_length && iface->link_speed) {
if (!l2_length)
l2_length = (family == IPADDR_INET4 ? iface->l2_udp4_ntp_start :
iface->l2_udp6_ntp_start) + rx_ntp_length + 4;
rx_correction = l2_length / (1.0e6 / 8 * iface->link_speed);
@ -493,22 +530,37 @@ NIO_Linux_ProcessMessage(NTP_Remote_Address *remote_addr, NTP_Local_Address *loc
{
struct Interface *iface;
struct cmsghdr *cmsg;
int is_tx, l2_length;
int is_tx, ts_if_index, l2_length;
is_tx = hdr->msg_flags & MSG_ERRQUEUE;
iface = NULL;
ts_if_index = local_addr->if_index;
l2_length = 0;
for (cmsg = CMSG_FIRSTHDR(hdr); cmsg; cmsg = CMSG_NXTHDR(hdr, cmsg)) {
#ifdef HAVE_LINUX_TIMESTAMPING_OPT_PKTINFO
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPING_PKTINFO) {
struct scm_ts_pktinfo ts_pktinfo;
memcpy(&ts_pktinfo, CMSG_DATA(cmsg), sizeof (ts_pktinfo));
ts_if_index = ts_pktinfo.if_index;
l2_length = ts_pktinfo.pkt_length;
DEBUG_LOG("Received HW timestamp info if=%d length=%d", ts_if_index, l2_length);
}
#endif
if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_TIMESTAMPING) {
struct scm_timestamping ts3;
memcpy(&ts3, CMSG_DATA(cmsg), sizeof (ts3));
if (!UTI_IsZeroTimespec(&ts3.ts[2])) {
iface = get_interface(local_addr->if_index);
iface = get_interface(ts_if_index);
if (iface) {
process_hw_timestamp(iface, &ts3.ts[2], local_ts, !is_tx ? length : 0,
remote_addr->ip_addr.family);
remote_addr->ip_addr.family, l2_length);
} else {
DEBUG_LOG("HW clock not found for interface %d", local_addr->if_index);
}