Allow to set the default values for streamid, ttl

sctp.py

@@ -230,7 +230,6 @@ def __init__(self, values=None):
 		self.stream = 0
 		self.ssn = 0
 		self.flags = 0
-		self.ppid = 0
 		self.context = 0
 		self.timetolive = 0
 		self.tsn = 0
@@ -1006,6 +1005,10 @@ class sctpsocket(object):
 		   associations, in seconds. A value of 0 means that no automatic close
 		   will be done. This property does not work for TCP-style sockets.
 
+	ttl: Default timetolive value to use with sctp_send. Default set to 0.
+
+	streamid: Default SCTP stream identifier value to use with sctp_send. Default set to 0.
+
 	IMPORTANT NOTE: the maximum message size is limited both by the implementation 
 	and by the transmission buffer (SO_SNDBUF). SCTP applications must configure 
 	the transmission and receiving bufers accordingly to the biggest messages it
@@ -1030,6 +1033,8 @@ def __init__(self, family, style, sk):
 		self._style = style
 		self._sk = sk
 		self._family = family
+		self._ttl = 0
+		self._streamid = 0
 
 		self.unexpected_event_raises_exception = False
 		self.initparams = initparams(self)
@@ -1107,7 +1112,7 @@ def getladdrs(self, assoc_id = 0): # -> tuple of sockaddrs as strings
 
 		return _sctp.getladdrs(self._sk.fileno(), assoc_id)
 
-	def sctp_send(self, msg, to=("",0), ppid=0, flags=0, stream=0, timetolive=0, context=0,
+	def sctp_send(self, msg, to=("",0), ppid=0, flags=0, stream=None, timetolive=None, context=0,
 	                    record_file_prefix="RECORD_sctp_traffic", datalogging = False):
 		"""
 		Sends a SCTP message. While send()/sendto() can also be used, this method also
@@ -1121,7 +1126,7 @@ def sctp_send(self, msg, to=("",0), ppid=0, flags=0, stream=0, timetolive=0, con
 		    WARNING: identifying destination by Association ID not implemented yet!
 
 		ppid: adaptation layer value, a 32-bit metadata that is sent along the message.
-		      Defaults to 0.
+		      Default to 0.
 
 		flags: a bitmap of MSG_* flags. For example, MSG_UNORDERED indicates that 
 		       message can be delivered out-of-order, and MSG_EOF + empty message 
@@ -1130,12 +1135,13 @@ def sctp_send(self, msg, to=("",0), ppid=0, flags=0, stream=0, timetolive=0, con
 		       It does NOT include flags like MSG_DONTROUTE or other low-level flags
 		       that are supported by sendto().
 
-		stream: stream number where the message will sent by. Defaults to 0.
+		stream: stream number where the message will sent by.
+				If not set use default value.
 
 		timetolive: time to live of the message in milisseconds. Zero means infinite
 		            TTL. If TTL expires, the message is discarded. Discarding policy
 			    changes whether implementation implements the PR-SCTP extension or not.
-			    Defaults to 0 (infinite).
+			    If not set use default value.
 
 		context: an opaque 32-bit integer that will be returned in some notification events,
 		         if the event is directly related to this message transmission. So the
@@ -1150,6 +1156,13 @@ def sctp_send(self, msg, to=("",0), ppid=0, flags=0, stream=0, timetolive=0, con
 		both by the implementation and by the transmission buffer (SO_SNDBUF).
 		The application must configure this buffer accordingly.
 		"""
+
+		if timetolive is None:
+			timetolive = self._ttl
+
+		if stream is None:
+			stream = self._streamid
+
 		if datalogging == True or self.datalogging == True:
 			now = datetime.datetime.now()
 			recordfilename = record_file_prefix + "-" + now.strftime("%Y%m%d%H%M%S") + "-c2s."
@@ -1625,6 +1638,36 @@ def set_rtoinfo(self, o):
 		"""
 		_sctp.set_rtoinfo(self._sk.fileno(), o.__dict__)
 
+	def get_ttl(self):
+		"""
+		Read default time to live value, 0 mean infinite
+		"""
+		return self._ttl
+
+	def set_ttl(self, newVal):
+		"""
+		Write default time to live
+		"""
+		if not isinstance(newVal, int) or newVal < 0 or newVal > 255:
+			raise ValueError('TTL shall be >= 0 and <= 255')
+
+		self._ttl = newVal
+
+	def get_streamid(self):
+		"""
+		Read default stream identifier
+ 		"""
+		return self._streamid
+
+	def set_streamid(self, newVal):
+		"""
+		Write default stream identifier
+		"""
+		if not isinstance(newVal, int) or newVal < 0 or newVal > 65535:
+			raise ValueError('streamid shall be a valid unsigned 16bits integer')
+
+		self._streamid = newVal
+
 	# delegation
 
 	def sock(self):
@@ -1649,6 +1692,8 @@ def __getattr__(self, name):
 	mappedv4 = property(get_mappedv4, set_mappedv4)
 	maxseg = property(get_maxseg, set_maxseg)
 	autoclose = property(get_autoclose, set_autoclose)
+	ttl = property(get_ttl, set_ttl)
+	streamid = property(get_streamid, set_streamid)
 
 class sctpsocket_tcp(sctpsocket):
 	"""