Wireshark-users: [Wireshark-users] Two http headers in packet?
From: Alan Snyder <alan8373@xxxxxxxxx>
Date: Fri, 5 Jun 2009 10:24:41 -0400
I'm looking at a packet that wireshark interprets as having 2 http
headers. This packet between a piece of software and a http proxy
(squid)... i'm trying to debug a connection problem. In wireshark,
when i look at this first packet which is the http connect, there are
2 http headers! the first header lists

proxy-connect-hostname ...
proxy-connect-port ...

...and the 2nd seems to be the normal http fields...

CONNECT ...
Host ...
Upgrade...
Connection...

What i'm trying to figure out is where the first header is coming
from... looking at the packet i dont see any additional bytes which
store this data. It seems to be extracted from real header. It's
confusing because it's listed as a completely separate header, after
the TCP data. Here's the raw packet...

0000  00 16 c7 ca a2 3f 00 14  4f 00 f2 72 08 00 45 00   .....?.. O..r..E.
0010  00 87 bc 1f 40 00 40 06  48 ee 0a 01 08 f5 0a 05   ....@.@. H.......
0020  18 69 ae 9b 76 2a 61 df  ec 85 37 ac b1 56 50 18   .i..v*a. ..7..VP.
0030  60 f4 35 dd 00 00 43 4f  4e 4e 45 43 54 20 31 30   `.5...CO NNECT 10
0040  2e 31 2e 38 2e 33 36 3a  34 32 36 20 48 54 54 50   .1.8.36: 426 HTTP
0050  2f 31 2e 31 0d 0a 48 6f  73 74 3a 20 31 30 2e 31   /1.1..Ho st: 10.1
0060  2e 38 2e 33 36 3a 34 32  36 20 0d 0a 55 70 67 72   .8.36:42 6 ..Upgr
0070  61 64 65 3a 20 54 4c 53  2f 31 2e 30 0d 0a 43 6f   ade: TLS /1.0..Co
0080  6e 6e 65 63 74 69 6f 6e  3a 20 55 70 67 72 61 64   nnection : Upgrad
0090  65 0d 0a 0d 0a                                     e....

Now, I have another packets that is practically identical to this one
(except for checksums, timestamps, etc), and that one in wireshark
only shows 1 http header...

0000  00 16 c7 ca a2 3f 00 14  4f 00 f2 72 08 00 45 00   .....?.. O..r..E.
0010  00 87 bc 37 40 00 40 06  48 d6 0a 01 08 f5 0a 05   ...7@.@. H.......
0020  18 69 af 74 76 2a 66 4a  c1 4f 3e ce aa d2 50 18   .i.tv*fJ .O>...P.
0030  60 f4 35 dd 00 00 43 4f  4e 4e 45 43 54 20 31 30   `.5...CO NNECT 10
0040  2e 31 2e 38 2e 33 36 3a  34 32 36 20 48 54 54 50   .1.8.36: 426 HTTP
0050  2f 31 2e 31 0d 0a 48 6f  73 74 3a 20 31 30 2e 31   /1.1..Ho st: 10.1
0060  2e 38 2e 33 36 3a 34 32  36 20 0d 0a 55 70 67 72   .8.36:42 6 ..Upgr
0070  61 64 65 3a 20 54 4c 53  2f 31 2e 30 0d 0a 43 6f   ade: TLS /1.0..Co
0080  6e 6e 65 63 74 69 6f 6e  3a 20 55 70 67 72 61 64   nnection : Upgrad
0090  65 0d 0a 0d 0a                                     e....

... it's the same http connect to the same proxy from the same host,
so with respect to IP and TCP they're basically the same. I've been
googling around for some insight but it's hard to google "http" since
any urls listed in a web page are a match... uggh!

Any help is greatly appreciated!
Thanks!