| Author | Message | Time |
|---|---|---|
| FooSoft | I'm working on a project that requires me to work with decompressed S > C packets. This means that if a packet is sent from the server decompressed it should be left alone, but if it is sent compressed in compressed format then then it should be decompressed. I have all of the decompression/compression stuff working fine, but I'm not sure how to tell if a packet in a "lump" recv'd from the D2GS is in compressed format or not. For compressed packets we have Size: 1-2 bytes (bytes[0] < 0xf0 ? 1 : 2) PacketId: 1 byte Data: ? bytes For decompressed packets it's simply PacketId: 1 byte Data ? bytes So when I receive a packet, is there any way to determine if the first byte is a: 1) First byte of a compressed packet's size 2) PacketId byte of a decompressed packet I really appreciate any help with this matter :) | October 18, 2006, 5:02 AM |
| l2k-Shadow | [quote author=FooSoft link=topic=15890.msg159962#msg159962 date=1161147740] I'm working on a project that requires me to work with decompressed S > C packets. This means that if a packet is sent from the server decompressed it should be left alone, but if it is sent compressed in compressed format then then it should be decompressed. I have all of the decompression/compression stuff working fine, but I'm not sure how to tell if a packet in a "lump" recv'd from the D2GS is in compressed format or not. For compressed packets we have Size: 1-2 bytes (bytes[0] < 0xf0 ? 1 : 2) PacketId: 1 byte Data: ? bytes For decompressed packets it's simply PacketId: 1 byte Data ? bytes So when I receive a packet, is there any way to determine if the first byte is a: 1) First byte of a compressed packet's size 2) PacketId byte of a decompressed packet I really appreciate any help with this matter :) [/quote] length of the packet... in any case the logic to that is obvious. since TCP data can be split among several packets, the packet must include a length for you to be able to receive all the data and then decompress. | October 18, 2006, 5:07 AM |
| FooSoft | Thanks for the reply, but I'm not sure I follow. Are you saying that a server "message" will always be enclosed in at least one whole packet regardless of whether or not it is compressed or decompressed? I found this not to be the case. The whole problem is that I don't know how to distinguish between compressed and decompressed messages if multiple messages arrive in one packet. There just appears to be a total lack of context of how to interpret this data. (messages being logical data D2GS sends out and packets are the TCP segmentation of it) | October 18, 2006, 5:24 AM |
| l2k-Shadow | they will always be compressed + D2GS messages have fixed lenghts. | October 18, 2006, 5:31 AM |
| FooSoft | Ah! All D2GS S > C messages are compressed? Awesome! I was under the impression that some were and some were not. That makes things a lot easier, thanks! | October 18, 2006, 5:38 AM |
| FooSoft | One more thing actually... Anyone know offhand if the packet length list on this page still applicable to 1.11b? https://davnit.net/bnet/vL/index.php?topic=11756.75 | October 18, 2006, 4:00 PM |
| NetNX | Most of that information is still accurate as far as packet structure although the packetids may be diffrent. | November 1, 2006, 4:38 PM |