'\" te
.\"  Copyright (c) 2007, Sun Microsystems, Inc.  All Rights Reserved
.TH sip_create_OKack 3SIP "25 Jan 2007" "SunOS 5.11" "Session Initiation Protocol Library Functions"
.SH NAME
sip_create_OKack \- create an ACK request for a final response
.SH SYNOPSIS
.LP
.nf
\fBcc\fR [ \fIflag\fR ... ] \fIfile\fR ... \fB-lsip\fR [ \fIlibrary\fR ... ]
#include <sip.h>

\fBint\fR \fIsip_create_OKack\fR(\fBsip_msg_t\fR \fIresponse\fR, 
     \fBsip_msg_t\fR \fIack_msg\fR, \fBchar *\fR\fItransport\fR, 
     \fBchar *\fR\fIsent_by\fR, \fBint\fR \fIsent_by_port\fR, 
     \fBchar *\fR\fIvia_params\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBsip_create_OKack()\fR function constructs an \fBACK\fR request in \fIack_msg\fR for the final \fB2\fR\fIXX\fR \fBSIP\fR response. The request line is created using the \fBURI\fR in the \fBCONTACT\fR header from the \fIresponse\fR. The SIP-Version in the request line is "2.0". The \fBVIA\fR header for the \fBACK\fR request is created using \fItransport\fR, \fIsent_by\fR, \fIsent_by_port\fR (if non-zero), and \fIvia_params\fR (if non-null). The following headers are copied to \fIack_msg\fR from \fIresponse\fR:
.br
.in +2
\fBFROM\fR
.in -2
.br
.in +2
\fBTO\fR
.in -2
.br
.in +2
\fBCALL-ID\fR
.in -2
.br
.in +2
\fBMAX_FORWARDS\fR
.in -2
.sp
.LP
The \fBCSEQ\fR header is created using the method as \fBACK\fR and the sequence number from the \fBCSEQ\fR header in \fIresponse\fR.
.SH RETURN VALUES
.sp
.LP
The \fBsip_create_OKack()\fR function returns \fB0\fR on success and the appropriate error value in case of failure.
.sp
.LP
The value of \fBerrno\fR is not changed by these calls in the event of an error.
.SH ERRORS
.sp
.LP
On failure, the \fBsip_create_OKack()\fR function could return one of the following errors:
.sp
.ne 2
.mk
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 11n
.rt  
If mandatory input is not provided or if the input is invalid.
.sp
The \fBsip_create_OKack()\fR function can return this error if it does not find a \fBCONTACT\fR header or if it is unable to obtain the \fBURI\fR from the \fBCONTACT\fR header for the request line.
.RE

.sp
.ne 2
.mk
.na
\fB\fBENOTSUP\fR\fR
.ad
.RS 11n
.rt  
If the input \fBSIP\fR message cannot be modified.
.RE

.sp
.ne 2
.mk
.na
\fB\fBENOMEM\fR\fR
.ad
.RS 11n
.rt  
If memory allocation fails when creating the request/response line or when creating headers in the \fBACK\fR request.
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Interface StabilityCommitted
_
MT-LevelMT-Safe
.TE

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