[tor-bugs] #5280 [Obfsproxy]: obfsproxy transport functions do not understand TCP

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#5280: obfsproxy transport functions do not understand TCP
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 Reporter:  asn        |          Owner:  asn
     Type:  defect     |         Status:  new
 Priority:  normal     |      Milestone:     
Component:  Obfsproxy  |        Version:     
 Keywords:             |         Parent:     
   Points:             |   Actualpoints:     
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Comment(by nickm):

 By "packet" here, do you literally mean a TCP packet, or what?  4096 bytes
 is a pretty high MTU for stuff over the real internet.

 What do you mean by "if the current chunk is the last one"?  I guess that
 you don't mean "the last one because the connection has just closed".
 What does it mean for a piece of data to be the "last" within a TCP stream
 if it isn't at the end?

 As I understand it, you are saying that data is coming in like
   <AAAAAAA><AAAAAA><AAAAAAA>
 and you want to stick a header and a footer around every <AAAAAAA>.

 Is each of these <AAAAAA>s literally a TCP packet, or what?  There is no
 reliable way to discover TCP packet boundaries from the Sockets protocol.
 You can *typically* infer that when you have read everything the kernel
 has to tell you, you have read some integer number of TCP packets, but you
 have no way to know whether you read one packet or more than one.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/5280#comment:3>
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