From 2814763bb86cc136fa7882446cd14e9e6b2e5339 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Mon, 27 Aug 2012 11:37:29 +0900 Subject: [PATCH] packet lib: add udp data transmit and checksum support - UDP supports sending data. - UDP calculates the checksum if not given. Signed-off-by: FUJITA Tomonori --- ryu/lib/packet/udp.py | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/ryu/lib/packet/udp.py b/ryu/lib/packet/udp.py index 05973c70..6fc84fc1 100644 --- a/ryu/lib/packet/udp.py +++ b/ryu/lib/packet/udp.py @@ -14,7 +14,10 @@ # limitations under the License. import struct +import socket from . import packet_base +from . import packet_utils +import ipv4 class udp(packet_base.PacketBase): @@ -40,5 +43,14 @@ class udp(packet_base.PacketBase): def serialize(self, payload, prev): if self.length == 0: self.length = struct.calcsize(udp._PACK_STR) + len(payload) - return struct.pack(udp._PACK_STR, self.src_port, self.dst_port, - self.length, self.csum) + h = struct.pack(udp._PACK_STR, self.src_port, self.dst_port, + self.length, self.csum) + if self.csum == 0: + ph = struct.pack('!IIBBH', prev.src, prev.dst, 0, 17, self.length) + f = ph + h + payload + if len(f) % 2: + f += '\0' + self.csum = socket.htons(packet_utils.checksum(f)) + h = struct.pack(udp._PACK_STR, self.src_port, self.dst_port, + self.length, self.csum) + return h