diff options
| author | Jim Panetta <panetta@slac.stanford.edu> | 2013-11-01 09:59:41 -0400 |
|---|---|---|
| committer | Gedare Bloom <gedare@rtems.org> | 2014-01-09 09:56:03 -0500 |
| commit | 2b03a62441d63d056dbbd6de17429ae05e4dfd04 (patch) | |
| tree | 69884909942a4ef6332c901d72f68a6492d0e50e | |
| parent | PR 1548: ERC32 console stops working when UART error flags are set (diff) | |
| download | rtems-2b03a62441d63d056dbbd6de17429ae05e4dfd04.tar.bz2 | |
NTP: Sync time correctly when receiving broadcast updates
1) The value of rtems_bsdnet_ntpserver_count is equal to 0 when no
server is set, so the check for (rtems_bsdnet_ntpserver_count < 0)
in rtems_bsdnet_get_ntp() is wrong. The check should be "<= 0".
2) Binding the listening socket port to 0 does not work. Packets
appear on the interface, but the recvfrom in tryServer() never
returns. Changing this to the well known NTP socket 123 allows
the packets to be seen.
3) In tryServer(), an explicit check for NTP version 3 packets is made.
If the NTP server is version 4, this check fails even though the
packets seem to be the right shape.
| -rw-r--r-- | cpukit/libnetworking/lib/rtems_bsdnet_ntp.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/cpukit/libnetworking/lib/rtems_bsdnet_ntp.c b/cpukit/libnetworking/lib/rtems_bsdnet_ntp.c index 4f991ff5b8..35092ea631 100644 --- a/cpukit/libnetworking/lib/rtems_bsdnet_ntp.c +++ b/cpukit/libnetworking/lib/rtems_bsdnet_ntp.c @@ -140,7 +140,8 @@ tryServer (int i, int s, rtems_bsdnet_ntp_callback_t callback, void *usr_data) } if ( i >= sizeof packet && - ((packet.li_vn_mode & (0x7 << 3)) == (3 << 3)) && + (((packet.li_vn_mode & (0x7 << 3)) == (3 << 3)) || + ((packet.li_vn_mode & (0x7 << 3)) == (4 << 3))) && ((packet.transmit_timestamp.integer != 0) || (packet.transmit_timestamp.fraction != 0)) && 0 == callback( &packet, 0 , usr_data) ) return 0; @@ -174,7 +175,7 @@ int ret; } memset (&myAddr, 0, sizeof myAddr); myAddr.sin_family = AF_INET; - myAddr.sin_port = htons (0); + myAddr.sin_port = htons (123); myAddr.sin_addr.s_addr = htonl (INADDR_ANY); if (bind (s, (struct sockaddr *)&myAddr, sizeof myAddr) < 0) { fprintf (stderr, "rtems_bsdnet_get_ntp() Can't bind socket: %s\n", strerror (errno)); @@ -190,7 +191,7 @@ int ret; * and hope that there's an NTP broadcast * server out there somewhere. */ - if (rtems_bsdnet_ntpserver_count < 0) { + if (rtems_bsdnet_ntpserver_count <= 0) { ret = tryServer (-1, sock, callback, usr_data); } else { |