grammar

Sofia SIP is an open-source SIP User-Agent library, compliant with the IETF RFC3261 specification.

/* SIP grammar from RFC3261
 * 
 *    alphanum  =  ALPHA / DIGIT
 * 
 *    reserved    =  ";" / "/" / "?" / ":" / "@" / "&" / "=" / "+"
 *                   / "$" / ","
 *    unreserved  =  alphanum / mark
 *    mark        =  "-" / "_" / "." / "!" / "~" / "*" / "'"
 *                   / "(" / ")"
 *    escaped     =  "%" HEXDIG HEXDIG
 * 
 *    LWS  =  [*WSP CRLF] 1*WSP ; linear whitespace
 *    SWS  =  [LWS] ; sep whitespace
 * 
 *    HCOLON  =  *( SP / HTAB ) ":" SWS
 * 
 *    TEXT-UTF8-TRIM  =  1*TEXT-UTF8char *(*LWS TEXT-UTF8char)
 *    TEXT-UTF8char   =  %x21-7E / UTF8-NONASCII
 *    UTF8-NONASCII   =  %xC0-DF 1UTF8-CONT
 *                    /  %xE0-EF 2UTF8-CONT
 *                    /  %xF0-F7 3UTF8-CONT
 *                    /  %xF8-Fb 4UTF8-CONT
 *                    /  %xFC-FD 5UTF8-CONT
 *    UTF8-CONT       =  %x80-BF
 * 
 *    LHEX  =  DIGIT / %x61-66 ;lowercase a-f
 * 
 *    token       =  1*(alphanum / "-" / "." / "!" / "%" / "*"
 *                   / "_" / "+" / "`" / "'" / "~" )
 *    separators  =  "(" / ")" / "<" / ">" / "@" /
 *                   "," / ";" / ":" / "\" / DQUOTE /
 *                   "/" / "[" / "]" / "?" / "=" /
 *                   "{" / "}" / SP / HTAB
 *    word        =  1*(alphanum / "-" / "." / "!" / "%" / "*" /
 *                   "_" / "+" / "`" / "'" / "~" /
 *                   "(" / ")" / "<" / ">" /
 *                   ":" / "\" / DQUOTE /
 *                   "/" / "[" / "]" / "?" /
 *                   "{" / "}" )
 * 
 *    STAR    =  SWS "*" SWS ; asterisk
 *    SLASH   =  SWS "/" SWS ; slash
 *    EQUAL   =  SWS "=" SWS ; equal
 *    LPAREN  =  SWS "(" SWS ; left parenthesis
 *    RPAREN  =  SWS ")" SWS ; right parenthesis
 *    RAQUOT  =  ">" SWS ; right angle quote
 *    LAQUOT  =  SWS "<"; left angle quote
 *    COMMA   =  SWS "," SWS ; comma
 *    SEMI    =  SWS ";" SWS ; semicolon
 *    COLON   =  SWS ":" SWS ; colon
 *    LDQUOT  =  SWS DQUOTE; open double quotation mark
 *    RDQUOT  =  DQUOTE SWS ; close double quotation mark
 * 
 *    comment  =  LPAREN *(ctext / quoted-pair / comment) RPAREN
 *    ctext    =  %x21-27 / %x2A-5B / %x5D-7E / UTF8-NONASCII
 *                / LWS
 * 
 *    quoted-string  =  SWS DQUOTE *(qdtext / quoted-pair ) DQUOTE
 *    qdtext         =  LWS / %x21 / %x23-5B / %x5D-7E
 *                      / UTF8-NONASCII
 * 
 *    quoted-pair  =  "\" (%x00-09 / %x0B-0C
 *                    / %x0E-7F)
 * 
 *    SIP-URI          =  "sip:" [ userinfo ] hostport
 *                        uri-parameters [ headers ]
 *    SIPS-URI         =  "sips:" [ userinfo ] hostport
 *                        uri-parameters [ headers ]
 *    userinfo         =  ( user / telephone-subscriber ) [ ":" password ] "@"
 *    user             =  1*( unreserved / escaped / user-unreserved )
 *    user-unreserved  =  "&" / "=" / "+" / "$" / "," / ";" / "?" / "/"
 *    password         =  *( unreserved / escaped /
 *                        "&" / "=" / "+" / "$" / "," )
 *    hostport         =  host [ ":" port ]
 *    host             =  hostname / IPv4address / IPv6reference
 *    hostname         =  *( domainlabel "." ) toplabel [ "." ]
 *    domainlabel      =  alphanum
 *                        / alphanum *( alphanum / "-" ) alphanum
 *    toplabel         =  ALPHA / ALPHA *( alphanum / "-" ) alphanum
 *    IPv4address    =  1*3DIGIT "." 1*3DIGIT "." 1*3DIGIT "." 1*3DIGIT
 *    IPv6reference  =  "[" IPv6address "]"
 *    IPv6address    =  hexpart [ ":" IPv4address ]
 *    hexpart        =  hexseq / hexseq "::" [ hexseq ] / "::" [ hexseq ]
 *    hexseq         =  hex4 *( ":" hex4)
 *    hex4           =  1*4HEXDIG
 *    port           =  1*DIGIT
 * 
 *    uri-parameters    =  *( ";" uri-parameter)
 *    uri-parameter     =  transport-param / user-param / method-param
 *                         / ttl-param / maddr-param / lr-param / other-param
 *    transport-param   =  "transport="
 *                         ( "udp" / "tcp" / "sctp" / "tls"
 *                         / other-transport)
 *    other-transport   =  token
 *    user-param        =  "user=" ( "phone" / "ip" / other-user)
 *    other-user        =  token
 *    method-param      =  "method=" Method
 *    ttl-param         =  "ttl=" ttl
 *    maddr-param       =  "maddr=" host
 *    lr-param          =  "lr"
 *    other-param       =  pname [ "=" pvalue ]
 *    pname             =  1*paramchar
 *    pvalue            =  1*paramchar
 *    paramchar         =  param-unreserved / unreserved / escaped
 *    param-unreserved  =  "[" / "]" / "/" / ":" / "&" / "+" / "$"
 * 
 *    headers         =  "?" header *( "&" header )
 *    header          =  hname "=" hvalue
 *    hname           =  1*( hnv-unreserved / unreserved / escaped )
 *    hvalue          =  *( hnv-unreserved / unreserved / escaped )
 *    hnv-unreserved  =  "[" / "]" / "/" / "?" / ":" / "+" / "$"
 * 
 *    SIP-message    =  Request / Response
 *    Request        =  Request-Line
 *                      *( message-header )
 *                      CRLF
 *                      [ message-body ]
 *    Request-Line   =  Method SP Request-URI SP SIP-Version CRLF
 *    Request-URI    =  SIP-URI / SIPS-URI / absoluteURI
 *    absoluteURI    =  scheme ":" ( hier-part / opaque-part )
 *    hier-part      =  ( net-path / abs-path ) [ "?" query ]
 *    net-path       =  "//" authority [ abs-path ]
 *    abs-path       =  "/" path-segments
 *    opaque-part    =  uric-no-slash *uric
 *    uric           =  reserved / unreserved / escaped
 *    uric-no-slash  =  unreserved / escaped / ";" / "?" / ":" / "@"
 *                      / "&" / "=" / "+" / "$" / ","
 *    path-segments  =  segment *( "/" segment )
 *    segment        =  *pchar *( ";" param )
 *    param          =  *pchar
 *    pchar          =  unreserved / escaped /
 *                      ":" / "@" / "&" / "=" / "+" / "$" / ","
 *    scheme         =  ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
 *    authority      =  srvr / reg-name
 *    srvr           =  [ [ userinfo "@" ] hostport ]
 *    reg-name       =  1*( unreserved / escaped / "$" / ","
 *                      / ";" / ":" / "@" / "&" / "=" / "+" )
 *    query          =  *uric
 *    SIP-Version    =  "SIP" "/" 1*DIGIT "." 1*DIGIT
 * 
 *    message-header  =  (Accept
 *                    /  Accept-Encoding
 *                    /  Accept-Language
 *                    /  Alert-Info
 *                    /  Allow
 *                    /  Authentication-Info
 *                    /  Authorization
 *                    /  Call-ID
 *                    /  Call-Info
 *                    /  Contact
 *                    /  Content-Disposition
 *                    /  Content-Encoding
 *                    /  Content-Language
 *                    /  Content-Length
 *                    /  Content-Type
 *                    /  CSeq
 *                    /  Date
 *                    /  Error-Info
 *                    /  Expires
 *                    /  From
 *                    /  In-Reply-To
 *                    /  Max-Forwards
 *                    /  MIME-Version
 *                    /  Min-Expires
 *                    /  Organization
 *                    /  Priority
 *                    /  Proxy-Authenticate
 *                    /  Proxy-Authorization
 *                    /  Proxy-Require
 *                    /  Record-Route
 *                    /  Reply-To
 *                    /  Require
 *                    /  Retry-After
 *                    /  Route
 *                    /  Server
 *                    /  Subject
 *                    /  Supported
 *                    /  Timestamp
 *                    /  To
 *                    /  Unsupported
 *                    /  User-Agent
 *                    /  Via
 *                    /  Warning
 *                    /  WWW-Authenticate
 *                    /  extension-header) CRLF
 * 
 *    INVITEm           =  %x49.4E.56.49.54.45 ; INVITE in caps
 *    ACKm              =  %x41.43.4B ; ACK in caps
 *    OPTIONSm          =  %x4F.50.54.49.4F.4E.53 ; OPTIONS in caps
 *    BYEm              =  %x42.59.45 ; BYE in caps
 *    CANCELm           =  %x43.41.4E.43.45.4C ; CANCEL in caps
 *    REGISTERm         =  %x52.45.47.49.53.54.45.52 ; REGISTER in caps
 *    Method            =  INVITEm / ACKm / OPTIONSm / BYEm
 *                         / CANCELm / REGISTERm
 *                         / extension-method
 *    extension-method  =  token
 *    Response          =  Status-Line
 *                         *( message-header )
 *                         CRLF
 *                         [ message-body ]
 * 
 *    Status-Line     =  SIP-Version SP Status-Code SP Reason-Phrase CRLF
 *    Status-Code     =  Informational
 *                   /   Redirection
 *                   /   Success
 *                   /   Client-Error
 *                   /   Server-Error
 *                   /   Global-Failure
 *                   /   extension-code
 *    extension-code  =  3DIGIT
 *    Reason-Phrase   =  *(reserved / unreserved / escaped
 *                       / UTF8-NONASCII / UTF8-CONT / SP / HTAB)
 * 
 *    Informational  =  "100"  ;  Trying
 *                  /   "180"  ;  Ringing
 *                  /   "181"  ;  Call Is Being Forwarded
 *                  /   "182"  ;  Queued
 *                  /   "183"  ;  Session Progress
 * 
 *    Success  =  "200"  ;  OK
 * 
 *    Redirection  =  "300"  ;  Multiple Choices
 *                /   "301"  ;  Moved Permanently
 *                /   "302"  ;  Moved Temporarily
 *                /   "305"  ;  Use Proxy
 *                /   "380"  ;  Alternative Service
 * 
 *    Client-Error  =  "400"  ;  Bad Request
 *                 /   "401"  ;  Unauthorized
 *                 /   "402"  ;  Payment Required
 *                 /   "403"  ;  Forbidden
 *                 /   "404"  ;  Not Found
 *                 /   "405"  ;  Method Not Allowed
 *                 /   "406"  ;  Not Acceptable
 *                 /   "407"  ;  Proxy Authentication Required
 *                 /   "408"  ;  Request Timeout
 *                 /   "410"  ;  Gone
 *                 /   "413"  ;  Request Entity Too Large
 *                 /   "414"  ;  Request-URI Too Large
 *                 /   "415"  ;  Unsupported Media Type
 *                 /   "416"  ;  Unsupported URI Scheme
 *                 /   "420"  ;  Bad Extension
 *                 /   "421"  ;  Extension Required
 *                 /   "423"  ;  Interval Too Brief
 *                 /   "480"  ;  Temporarily not available
 *                 /   "481"  ;  Call Leg/Transaction Does Not Exist
 *                 /   "482"  ;  Loop Detected
 *                 /   "483"  ;  Too Many Hops
 *                 /   "484"  ;  Address Incomplete
 *                 /   "485"  ;  Ambiguous
 *                 /   "486"  ;  Busy Here
 *                 /   "487"  ;  Request Terminated
 *                 /   "488"  ;  Not Acceptable Here
 *                 /   "491"  ;  Request Pending
 *                 /   "493"  ;  Undecipherable
 * 
 *    Server-Error  =  "500"  ;  Internal Server Error
 *                 /   "501"  ;  Not Implemented
 *                 /   "502"  ;  Bad Gateway
 *                 /   "503"  ;  Service Unavailable
 *                 /   "504"  ;  Server Time-out
 *                 /   "505"  ;  SIP Version not supported
 *                 /   "513"  ;  Message Too Large
 * 
 *    Global-Failure  =  "600"  ;  Busy Everywhere
 *                   /   "603"  ;  Decline
 *                   /   "604"  ;  Does not exist anywhere
 *                   /   "606"  ;  Not Acceptable
 *