simple browser to web-proxy connection?

[bornf]

My issue is to connect two computers by serial-cable. A webbrowser on system-a should communicate to a squid-proxy on system-b.

try with ser2net

I successfully created a connection with the original ser2net with following settings:

ser2net config on system-a and system-b:
2000:raw:5:/dev/ttyS0:9600 NONE 1STOPBIT 8DATABITS RTSCTS

The connection between the listening squid on port 3128 and ser2net on port 2000 on system-b is done with a script and socat:

while true; do
    socat -d -d -v TCP:localhost:2000 TCP:localhost:3128
done

On system-a in a firefox-browser with the setting network.max-connections = 1, it mostly does work, but not very well... Obviously, the reason is the lack of multiple connections.

try with ser2nets

I successfully compiled ser2nets on both systems and used the same config as above. Additionally, I activated logging:

TRACEFILE:tw1:/tmp/tw-\p-\Y-\M-\D-\H:\i:\s.\U
TRACEFILE:tr1:/tmp/tr-\p-\Y-\M-\D-\H:\i:\s.\U
2000:raw:600:/dev/ttyS0:9600 NONE 1STOPBIT 8DATABITS RTSCTS tw=tw1 tr=tr1

I checked with nc an socat:

nc 127.0.0.1 2000 | cat
socat -d -d -v TCP:localhost:2000 -

...and nothing was sent to port 2000 on system-b:
But the log-file has received browser-request-data from system-a:

[D] tcps: 0 (0, 6) 6 (0, 0)
GET http://start.ubuntu.com/14.10/Google/?sourceid=hp HTTP/1.1
Host: start.ubuntu.com
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:36.0) Gecko/20100101 Firefox/36.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: de,en-US;q=0.7,en;q=0.3
Accept-Encoding: gzip, deflate
Connection: keep-alive

tcp 6 shutdown: tcp read close
[D] tcps: 0 (0, 0)
[D] tcps: 0 (0, 6) 6 (0, 0)
CONNECT tiles.services.mozilla.com:443 HTTP/1.1
User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:36.0) Gecko/20100101 Firefox/36.0
Proxy-Connection: keep-alive
Connection: keep-alive
Host: tiles.services.mozilla.com:443

My mistake is the wrong handling with the multiple connections, I think. How do I correct connect ser2nets with squid on system-b?

[longshine]

Hi~

Sorry for ser2nets not working. As far as I know, the reverse channel (network to serial) is not enabled for multiple connections for some reason.

For instance, assume that we have a ser2nets running on /dev/ttyS0 on system-a, with duplex on, and currently 3 parallel HTTP requests from the web browser. Two things will happen:

• There is NO garantee that each request will be transferred to the serial orderly. They might be split into small fragments and mixed up while running through the cable.
• Any data from the serial port will be deliverred to all of the 3 connections, which means each connection will receive more responses than what it wants. This may not be blamed on ser2net. You cannot tell among different responses from a single channel without additional info.

What I suggest is to create a protocol to wrap/unwrap HTTP requests/responses, like TCP/IP over Internet wire. The original ser2net will be OK.