[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [lwip-users] Pulling data from a server using HTTP with lwIP

From: Simon Goldschmidt
Subject: Re: [lwip-users] Pulling data from a server using HTTP with lwIP
Date: Thu, 13 Nov 2014 17:13:05 +0100

Robert Wood wrote:
> Sorry, I'm obviously still not explaining this clearly.

I don't really think that this is our problem...

To get a grip on this, could you please explain your pcaps:

- which IP is lwIP, which IP is the remote host in question (there are plenty 
of hosts in your pcap file, not only 2!)
- which packet numbers are you talking about?
- which packet number exactly is the one you wouldn't expect, or in other 
words, where would the missing ACK be inserted?

I can again try to explain why *I* think that packet #54 in 
"no_ack_but_get.pcap" is correct: I think you are expecting an ACK packet here 
(note that an [ACK] packet is only a description of wireshark: in TCP, this is 
a packet with the ACK flag set but no user data contained).

Instead of this packet (ACK but no data) you get the "GET" request, which in 
TCP is ACK+DATA. This is perfectly valid to me.

Maybe you should tell us what the real problem is. I think your real problem is 
the missing HTTP answer. So why not start and send a correct HTTP request? Like 
Mikale Eiman wrote, "GET /index.html HTTP/1.0\r\n\r\n" (double newline at the 
end) should be enough when the send length is correct (you seem to be sending 
invalid data after the HTTP header!).

Hope that helps,

reply via email to

[Prev in Thread] Current Thread [Next in Thread]