About

sipparser is a high performce parser for Session Initiated
Protocol messages.  It provides a library for use in building 
SIP user agents or any program in go that needs to be able to
parse SIP messages.

Installation

(the following steps assume that you have mercurial and go
installed already)
1. hg clone https://[email protected]/sdr/sip_parser
2. cd sip_parser
3. make clean && make && make install

Usage

The library has an easy to use interface.  

1. call sipparser.ParseMsg(msg string)
2. you'll get back a *SipMsg struct with the following:
    -- State is the last parsing state
    -- Error is an os.Error
    -- Msg is the raw msg
    -- CallingParty is a *CallingParty struct (see below)
    -- Body is the body of the message
    -- StartLine is the parsed StartLine (see below)
    -- Headers is a slice of *Headers (see below) and will
       only contain headers that do not get parsed 
    -- Accept is a *Accept struct (see below)
    -- AlertInfo is just the string of the Alert-Info hdr
    -- Allow is a slice of strings of the methods that are 
       allowed
    -- AllowEvents is a slice of strings of the supported
       event types
    -- ContentDisposition is a *ContentDisposition struct 
    -- ContentLength is the value of the Content-Length hdr
    -- ContentLengthInt is the int value of the ContentLength
    -- ContentType is the header value for the Content-Type hdr
    -- From is a *From struct (see below)
    -- MaxForwards is the hdr value for the Max-Forwards hdr
    -- MaxForwardsInt is the int value of the MaxForwards field
    -- Organization is the value for the Organization hdr
    -- To is a *From struct (see below)
    -- Contact is a *From struct (see below) 
       ** NOTE ** Contact is not parsed automatically.  You 
       have to call *SipMsg.ParseContact() to get this value.
    -- ContactVal is the raw value of the contact hdr
    -- CallId is the call-id for the message
    -- Cseq is a *Cseq struct (see below)
    -- Rack is a *Rack struct (see below)
    -- Reason is a *Reason struct
    -- Rseq is the value of the RSeq hdr
    -- RseqInt is the int value of the Rseq
    -- RecordRoute is a slice of *URI's structs (see below)
    -- Route is a slice of *URI's structs (see below) 
    -- Via is a slice of *Via structs (see below)
    -- Require is a slice of the required extensions (string
       values) from the Require hdr
    -- Supported is a slice of the supported extensions (string
       values) from the Supported hdr
    -- Privacy is the value of the Privacy hdr
    -- ProxyRequire is a slice of strings from the 
       Proxy-Require hdr
    -- RemotePartyIdVal is the value from the Remote-Party-Id hdr
    -- RemotePartyId is the RemotePartyId struct 
       ** NOTE ** In order to actually get this value you have to
       call *SipMsg.ParseRemotePartyId()
    -- PAssertedIdVal is the value from the P-Asserted-Identity hdr
    -- PAssertedId is the *PAssertedId struct
       ** NOTE ** In order to actually get this value you have to 
       call *SipMsg.ParsePAssertedId()
    -- Unsupported is a slice of the unsupported extensions from
       the Unsupported hdr
    -- UserAgent is the value of the User-Agent hdr
    -- Server is the value of the Server hdr
    -- Subject is the value of the Subject hdr
    -- Warning is a *Warning struct (see below)

Import Types 

The following types are also part of the parsed SIP message. 

Accept is a struct with the following fields:
-- Val is the raw value
-- Params is a slice of AcceptParam

CallingPartyInfo is a struct of calling party information.  
This is populated into the *SipMsg.CallingParty field when 
the method GetCallingParty on the *SipMsg.  See below for 
details of that method.
CallingPartyInfo has the following fields:
-- Name the name
-- Number the number
-- Anonymous a bool to see if this should be anonymous or not


ContentDisposition is a struct with the following fields:
-- Val is the raw value
-- DispType is the display type
-- Params is a slice of *Param (see below)

Cseq is a struct with the following fields:
-- Val is the raw value
-- Method is the SIP method
-- Digit is the digit (although in a string format)

From is an important type that is used as a representation of
the parsed hdr values for the From, To, and Contact headers.
The From struct has the following fields:
-- Error is an os.Error
-- Val is the raw value
-- Name is the name value from the hdr
-- Tag is the value of the tag=$someval parameter
-- URI is the *URI 
-- Params is a slice of *Param (see below)

Param is a struct with the following fields:
-- Param is the parameter 
-- Val is the value of the parameter (if any ...)

PAssertedId is a struct with the following fields:
-- Error is an os.Error
-- Val is the raw value
-- Name is the name from the header
-- URI is the *URI
-- Params is a slice of *Param

Rack is a struct with the following fields:
-- Val is the raw value
-- RseqVal is the value of the rseq
-- CseqVal is the value of the cseq
-- CseqMethod is the value of the cseq method

Reason is a struct with the following fields:
-- Val is the raw value
-- Proto is the protocol
-- Cause is the cause code
-- Text is the text

RemotePartyId is a struct with the following fields:
-- Error is an os.Error
-- Val is the raw value of the hdr
-- Name is the name from the header
-- URI is the *URI
-- Party is the party parameter
-- Screen is the screen parameter 
-- Privacy is the privacy parameeter
-- Params is a slice of *Param

StartLine is a struct with the following fields:
-- Error is an os.Error
-- Val is the raw value
-- Type is the type of startline (i.e. request or response)
-- Method is the method (if request)
-- URI is the *URI (if request) 
-- Resp is the response code (i.e. 183)
-- RespText is the response text (i.e. "Session Progress")
-- Proto is the protocol (should be "SIP")
-- Version is the version (should be "2.0")

URI is an important struct that is used in many places 
through a *SipMsg from the From header to the StartLine.
It has the following fields:
-- Error is an os.Error
-- Scheme is the scheme (i.e. "sip", "sips", "tel")
-- Raw is the raw value of the uri 
-- UserInfo is everything before the "@" char if anything 
-- User is the user (i.e. "bob")
-- UserPassword is the password (if any) 
-- HostInfo is everything between the "@" char and any parameters
-- Host is the host
-- Port is the port
-- UriParams is a slice of *Param
-- Secure is a bool indicating if communication is secure 

Via is an important part of the *SipMsg.  It is a fundamental
basis on which to build route-sets and do call matching.  It
has the following structs:
-- State is the parser state
-- Error is an os.Error
-- Via is the raw value
-- Proto is the protocol (i.e. "SIP")
-- Version is the version (i.e. "2.0")
-- Transport is the transport method (i.e. "UDP")
-- SentBy is a host:port combination 
-- Branch is the branch parameter
-- Params is a slice of *Param

Import Methods on the *SipMsg

GetCallingParty

GetCallingParty is a method that can be called with one of 
the following:
-- rpid (abbr for remote-party-id)
-- paid (abbr for party-associated-identity)
If either of the above parameters are passed to the method
then it will use one of the matching hdrs to obtain the info.
If anything else is passed then it will pull the CallingPartyInfo
from the from header.

GetRURIParamBool

GetRURIParamBool returns true or false to see if a parameter
is present in the request URI

GetRURIParamVal 

GetRURIParamVal returns the actual value of the parameter if
the parameter is present in the request URI