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tcp_window_size.c
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tcp_window_size.c
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/*---------------------------------------------------------------
* Copyright (c) 1999,2000,2001,2002,2003
* The Board of Trustees of the University of Illinois
* All Rights Reserved.
*---------------------------------------------------------------
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software (Iperf) and associated
* documentation files (the "Software"), to deal in the Software
* without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute,
* sublicense, and/or sell copies of the Software, and to permit
* persons to whom the Software is furnished to do
* so, subject to the following conditions:
*
*
* Redistributions of source code must retain the above
* copyright notice, this list of conditions and
* the following disclaimers.
*
*
* Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimers in the documentation and/or other materials
* provided with the distribution.
*
*
* Neither the names of the University of Illinois, NCSA,
* nor the names of its contributors may be used to endorse
* or promote products derived from this Software without
* specific prior written permission.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE CONTIBUTORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
* ________________________________________________________________
* National Laboratory for Applied Network Research
* National Center for Supercomputing Applications
* University of Illinois at Urbana-Champaign
* http://www.ncsa.uiuc.edu
* ________________________________________________________________
*
* tcp_window_size.c
* by Mark Gates <mgates@nlanr.net>
* -------------------------------------------------------------------
* set/getsockopt
* ------------------------------------------------------------------- */
#include "headers.h"
#include "util.h"
#ifdef __cplusplus
extern "C" {
#endif
/* -------------------------------------------------------------------
* If inTCPWin > 0, set the TCP window size (via the socket buffer
* sizes) for inSock. Otherwise leave it as the system default.
*
* This must be called prior to calling listen() or connect() on
* the socket, for TCP window sizes > 64 KB to be effective.
*
* This now works on UNICOS also, by setting TCP_WINSHIFT.
* This now works on AIX, by enabling RFC1323.
* returns -1 on error, 0 on no error.
* ------------------------------------------------------------------- */
int setsock_tcp_windowsize( int inSock, int inTCPWin, int inSend ) {
#ifdef SO_SNDBUF
int rc;
int newTCPWin;
assert( inSock >= 0 );
if ( inTCPWin > 0 ) {
#ifdef TCP_WINSHIFT
/* UNICOS requires setting the winshift explicitly */
if ( inTCPWin > 65535 ) {
int winShift = 0;
int scaledWin = inTCPWin >> 16;
while ( scaledWin > 0 ) {
scaledWin >>= 1;
winShift++;
}
/* set TCP window shift */
rc = setsockopt( inSock, IPPROTO_TCP, TCP_WINSHIFT,
(char*) &winShift, sizeof( winShift ));
if ( rc < 0 ) {
return rc;
}
/* Note: you cannot verify TCP window shift, since it returns
* a structure and not the same integer we use to set it. (ugh) */
}
#endif /* TCP_WINSHIFT */
#ifdef TCP_RFC1323
/* On AIX, RFC 1323 extensions can be set system-wide,
* using the 'no' network options command. But we can also set them
* per-socket, so let's try just in case. */
if ( inTCPWin > 65535 ) {
/* enable RFC 1323 */
int on = 1;
rc = setsockopt( inSock, IPPROTO_TCP, TCP_RFC1323,
(char*) &on, sizeof( on ));
if ( rc < 0 ) {
return rc;
}
}
#endif /* TCP_RFC1323 */
if ( !inSend ) {
/* receive buffer -- set
* note: results are verified after connect() or listen(),
* since some OS's don't show the corrected value until then. */
newTCPWin = inTCPWin;
rc = setsockopt( inSock, SOL_SOCKET, SO_RCVBUF,
(char*) &newTCPWin, sizeof( newTCPWin ));
} else {
/* send buffer -- set
* note: results are verified after connect() or listen(),
* since some OS's don't show the corrected value until then. */
newTCPWin = inTCPWin;
rc = setsockopt( inSock, SOL_SOCKET, SO_SNDBUF,
(char*) &newTCPWin, sizeof( newTCPWin ));
}
if ( rc < 0 ) {
return rc;
}
}
#endif /* SO_SNDBUF */
return 0;
} /* end setsock_tcp_windowsize */
/* -------------------------------------------------------------------
* returns the TCP window size (on the sending buffer, SO_SNDBUF),
* or -1 on error.
* ------------------------------------------------------------------- */
int getsock_tcp_windowsize( int inSock, int inSend ) {
int theTCPWin = 0;
#ifdef SO_SNDBUF
int rc;
Socklen_t len;
/* send buffer -- query for buffer size */
len = sizeof( theTCPWin );
if ( inSend ) {
rc = getsockopt( inSock, SOL_SOCKET, SO_SNDBUF,
(char*) &theTCPWin, &len );
} else {
rc = getsockopt( inSock, SOL_SOCKET, SO_RCVBUF,
(char*) &theTCPWin, &len );
}
if ( rc < 0 ) {
return rc;
}
#endif
return theTCPWin;
} /* end getsock_tcp_windowsize */
#ifdef __cplusplus
} /* end extern "C" */
#endif