Setting SO_SNDBUF and SO_RCVBUF

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Hello,

man tcp on RHEL4 (2.6.9-68) says the following:

The maximum sizes for socket buffers declared via the SO_SNDBUF and
SO_RCVBUF  mechanisms are limited by the global net.core.rmem_max and
net.core.wmem_max sysctls.  Note that TCP actually allocates twice the
size of the buffer requested in the setsockopt(2)  call,  and so a
succeeding getsockopt(2) call will not return the same size of buffer as
requested in the setsockopt(2) call.  TCP uses this for administrative
purposes  and  internal  kernel structures,  and  the sysctl variables
reflect the larger sizes compared to the actual TCP       windows.
-->
On individual connections, the socket buffer size must be set prior to
the listen() or connect() calls in order to have it take effect. See
socket(7) for more information.
<--

Is the last bit above true - i.e. does the setsockopt have to be done
before the connect()/listen() calls? (I seem to be able to do it at
anytime but am not sure if TCP actually uses the new value as per the
above comment)

Thanks,
Mayuresh.

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