HP-UX C SIP Stack Programmer's Guide (Novembery 2007)

170 HP-UX C SIP Stack Programmer’s Guide

Handling Messages with Syntax Errors

You can use this function in the RvSipTransportBadSyntaxStartLineMsgEv()

callback to check and fix the defected start-line.

RvSipMsgGetHeaderExt(), RvSipMsgGetHeaderByTypeExt(),

RvSipMsgGetHeaderByNameExt()

These three function extend the functionality of functions that already exists in

the SIP Stack API. RvSipMsgGetHeaderExt() extends the

RvSipMsgGetHeader() function; RvSipMsgGetHeaderByTypeExt() extends the

RvSipMsgGetHeaderByType function; and RvSipMsgGetHeaderByNameExt()

extends the RvSipMsgGetHeaderByName.

These functions enable the application to specify whether it wishes to get only

legal headers or both legal and illegal headers. (An illegal header is a header

with a bad-syntax string.)

Note Using the regular function retrieves only legal headers.

RvSipMsgStartLineFix()

Fixes a start-line with bad-syntax information. When a message is received with

a bad syntax start line, the start line string is kept as a separate “bad-syntax”

string in the message. Use this function in the

RvSipTransportBadSyntaxStartLineMsgEv() callback to fix a defected start-

line.

When fixing a start line, you need to supply a string with a correct start line. The

Stack will parse this string into the message. If parsing succeeds, the function

will place all fields inside the message start-line parameters and will remove the

bad syntax string. If parsing fails, the start line bad-syntax string remains

untouched.

RvSipHeaderIsBadSyntax()

This function identifies if a given header is or is not a bad-syntax header.

DDITIONAL BAD SYNTAX

UNCTIONS

A SIP header has the following grammar: header-name: header-value. When a

header contains a syntax error, the header-value is kept as a separate bad-syntax

string. The following functions are supplied for each of the SIP Stack headers.

“XXX” in the function name represents the header name.