Re: ntpd on 6.0_BETA2

[Mark Davies <mark%ecs.vuw.ac.nz@localhost>]

On Fri, 17 Aug 2012, you wrote:
> Debugging output from ntpd suggests that all the broadcast lines
> from the config file (which hasn't changed) are being processed
> but tcpdump shows no local broadcasts being sent out.

A little more poking gives

For the local broadcast:


  1980      1 ntpd     CALL  write(1,0xbb713000,0x40)
  1980      1 ntpd     GIO   fd 1 wrote 64 bytes
       "sendpkt(23, dst=130.195.5.255, src=130.195.5.12, ttl=0, 
len=48)\n"
  1980      1 ntpd     RET   write 64/0x40
  1980      1 ntpd     CALL  
sendto(0x17,0xbfbfe1b4,0x30,0,0x80ec08c,0x10)
  1980      1 ntpd     MISC  msghdr: [name=0x80ec08c, namelen=16, 
iov=0xdafa2c7c, iovlen=1, control=0x0, co
ntrollen=133, flags=0]
  1980      1 ntpd     MISC  mbsoname: [130.195.5.255]
  1980      1 ntpd     RET   sendto -1 errno 13 Permission denied
  1980      1 ntpd     CALL  __clock_gettime50(0,0xbfbfe144)
  1980      1 ntpd     RET   __clock_gettime50 0
  1980      1 ntpd     CALL  write(1,0xbb713000,0x3b)
  1980      1 ntpd     GIO   fd 1 wrote 59 bytes
       "transmit: at 202 130.195.5.12->130.195.5.255 mode 5 len 48\n"
  1980      1 ntpd     RET   write 59/0x3b



For a directed broadcast:

  1980      1 ntpd     CALL  write(1,0xbb713000,0x40)
  1980      1 ntpd     GIO   fd 1 wrote 64 bytes
       "sendpkt(23, dst=130.195.8.255, src=130.195.5.12, ttl=0, 
len=48)\n"
  1980      1 ntpd     RET   write 64/0x40
  1980      1 ntpd     CALL  
sendto(0x17,0xbfbfe1b4,0x30,0,0x80eb7ec,0x10)
  1980      1 ntpd     MISC  msghdr: [name=0x80eb7ec, namelen=16, 
iov=0xdafa2c7c, iovlen=1, control=0x0, controllen=133, flags=0]
  1980      1 ntpd     MISC  mbsoname: [130.195.8.255]
  1980      1 ntpd     GIO   fd 23 wrote 48 bytes
       "\^]\^B\^F\M-o\0\0\^E\M-Q\0\0\M-y*\M^C\M-K\^P\^F\M-S\M-
XN\M^Nl\M-[\M-M\M-A\0\0\0\0\0\0\0\0\0\0\0\0\
        \0\0\0\0\M-S\M-XN\M^\g\M-B\M-K\M^A"
  1980      1 ntpd     RET   sendto 48/0x30
  1980      1 ntpd     CALL  __clock_gettime50(0,0xbfbfe144)
  1980      1 ntpd     RET   __clock_gettime50 0
  1980      1 ntpd     CALL  write(1,0xbb713000,0x3b)
  1980      1 ntpd     GIO   fd 1 wrote 59 bytes
       "transmit: at 207 130.195.5.12->130.195.8.255 mode 5 len 48\n"
  1980      1 ntpd     RET   write 59/0x3b


Note the "Permission denied" on the sendto for the local broadcast.


cheers
mark