'\" te
.\"  Copyright (c) 2007, Sun Microsystems, Inc.  All Rights Reserved
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
.\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
.TH SIP_BRANCHID 3SIP "Jan 25, 2007"
.SH NAME
sip_branchid \- generate a RFC 3261 complaint branch ID
.SH SYNOPSIS
.LP
.nf
\fBcc\fR [ \fIflag\fR ... ] \fIfile\fR ... \fB-lsip\fR [ \fIlibrary\fR ... ]
#include <sip.h>

\fBchar *\fR\fIsip_branchid\fR(\fBsip_msg_t\fR \fIsip_msg\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBsip_branchid()\fR function can be used to generate a value for the
branch parameter for a \fBVIA\fR header. The returned string is prefixed with
\fBz9hG4bK\fR to conform to RFC 3261. If \fIsip_msg\fR is null or \fIsip_msg\fR
does not have a \fBVIA\fR header, a random value is generated. Otherwise, the
value is generated using the \fBMD5\fR hash of the \fBVIA\fR, \fBFROM\fR,
\fBCALL-ID\fR, \fBCSEQ\fR headers and the \fBURI\fR from the request line. The
caller is responsible for freeing the returned string.
.SH RETURN VALUES
.sp
.LP
The \fBsip_branchid()\fR function returns a string on success and \fBNULL\fR on
failure.
.sp
.LP
The value of \fBerrno\fR is not changed by these calls in the event of an
error.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Committed
_
MT-Level	MT-Safe
.TE

.SH SEE ALSO
.sp
.LP
\fBlibsip\fR(3LIB)