Sunpy/sampy
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Packet handling order of operations notes

Browse Source
This commit is contained in:
Emily
2020-04-04 23:12:24 +02:00
parent 37e732e19f
commit 0cd474601a
2 changed files with 25 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
notes/packet_writeup.md
View File

@@ -11,6 +11,25 @@
## Shared
* Can be internal packet
* If packet is smaller then 3 bytes; forward to plugin handlers (*)before handling them (len(data) <= 2)
## Order of operations
1. Check if banned (if true, cancel rest and handle) [^1]
2. If first byte in data is (0x19, 0x1d, 0x1f, 0x24 or 0x18) custom code flow required [^2]
3. HandleSocketReceiveFromConnectedPlayer (cancel rest if handled)
4. Check if cheat (modified) packet (unexpected at this time, there are some packets we can expect) [^3]
[^1]: this could be changed in custom implementation (dont allow inital connection instead)
[^2]: if (0x18 and length == 2) or (0x19 and length <= 2):
handle packet and return
elif (0x1d or 0x1f or 0x24) and length <= 2:
handle packet, but continue
[^3]: if ((0x18 or 0x1a) and length <= 3) or ((0x19 or 0x1d) and length <= 2) or
((0x08 or 0x07 or 0x27) and length >= 5) or (0x37 and length < 400):
We expect this packet, everything is ok?
else:
This is a cheat (modified / injected) packet that should not arrive at this time
Send a packet to client that you received a modified packet (0x26)
# Internal packet
|condition|name|bit length|type|notes|