[squid-users] SQUID TPROXY option does not work when URL is on the same machine as SQUID

Hello,

We are using squid to transparently proxy the traffic to a captive
portal that is residing on the same machine as the squid server. The
solution was working based on a NAT REDIRECT . We are moving the
solution to TPROXY based now as part of migration to IPv6. The TPROXY
works fine in intercepting traffic and also successfully able to allow
/ deny traffic to IPv6 sites. We are facing a strange issue when we
try to access a URL in the same machine that hosts the squid server.
The acces hangs and squid is not able to connect to the URL. We are
having AOL webserver to host the webpage.

All the configurations as recommended by the squid sites are done.
-> Firewall rules with TPROXY and DIVERT chian has been setup as below

ip6tables -t mangle -N DIVERT
ip6tables -t mangle -A DIVERT -j MARK --set-mark 1
ip6tables -t mangle -A DIVERT -j ACCEPT
ip6tables -t mangle -A PREROUTING -p tcp -m socket -j DIVERT
ip6tables -t mangle -A PREROUTING -m tos --tos 0x20 -j ACCEPT
ip6tables -t mangle -A PREROUTING  -i eth0.20 -p tcp --dport 80 -j
TPROXY --tproxy-mark 0x1/0x1 --on-port 8085
ip6tables -t mangle -A PREROUTING -j ACCEPT

-> Policy routing to route proxied traffic to the local box is also
done as recommended
16383:  from all fwmark 0x1 lookup 100
16390:  from all lookup local
32766:  from all lookup main

ip -6 route show table 100
local default dev lo  metric 1024
local default dev eth0.20  metric 1024

Squid configuration used is standard and have provided below a
snapshot of cache.log. Running squid in full debug level with max
logging. I have provided the final set of logs for this transaction.
The URL accessed in the test is
http://[2001:4b8:1::549]/sample_page.adp.

Appreciate any assistance / pointers to solve this. Please do let me
know if any additional information is required.

2012/03/05 04:29:26.320 kid1| HTTP Server REQUEST:
---------
GET /sample_page.adp HTTP/1.1
User-Agent: w3m/0.5.2
Accept: text/html, text/*;q=0.5, image/*, application/*, audio/*, multipart/*
Accept-Encoding: gzip, compress, bzip, bzip2, deflate
Accept-Language: en;q=1.0
Host: [2001:4b8:1::549]
Via: 1.0 nmd.tst26.aus.wayport.net (squid/3.2.0.15-20120228-r11519)
X-Forwarded-For: 2001:4b8:1:5:250:56ff:feb2:2cfc
Cache-Control: max-age=259200
Connection: keep-alive

----------
2012/03/05 04:29:26.320 kid1| Write.cc(21) Write:
local=[2001:4b8:1:5:250:56ff:feb2:2cfc]:43673
remote=[2001:4b8:1::549]:80 FD 13 flags=25: sz 417: asynCall
0x871f6e8*1
2012/03/05 04:29:26.320 kid1| ModPoll.cc(149) SetSelect: FD 13,
type=2, handler=1, client_data=0x84df560, timeout=0
2012/03/05 04:29:26.320 kid1| HttpStateData status out: [ job7]
2012/03/05 04:29:26.321 kid1| leaving AsyncJob::start()
2012/03/05 04:29:26.321 kid1| event.cc(252) checkEvents: checkEvents
2012/03/05 04:29:26.321 kid1| The AsyncCall MaintainSwapSpace
constructed, this=0x871ff48 [call204]
2012/03/05 04:29:26.321 kid1| event.cc(261) will call
MaintainSwapSpace() [call204]
2012/03/05 04:29:26.321 kid1| entering MaintainSwapSpace()
2012/03/05 04:29:26.321 kid1| AsyncCall.cc(34) make: make call
MaintainSwapSpace [call204]
2012/03/05 04:29:26.321 kid1| event.cc(344) schedule: schedule: Adding
'MaintainSwapSpace', in 1.00 seconds
2012/03/05 04:29:26.321 kid1| leaving MaintainSwapSpace()
2012/03/05 04:29:27.149 kid1| event.cc(252) checkEvents: checkEvents
2012/03/05 04:29:27.149 kid1| The AsyncCall memPoolCleanIdlePools
constructed, this=0x871ff48 [call205]
2012/03/05 04:29:27.149 kid1| event.cc(261) will call
memPoolCleanIdlePools() [call205]
2012/03/05 04:29:27.149 kid1| entering memPoolCleanIdlePools()
2012/03/05 04:29:27.149 kid1| AsyncCall.cc(34) make: make call
memPoolCleanIdlePools [call205]
2012/03/05 04:29:27.150 kid1| event.cc(344) schedule: schedule: Adding
'memPoolCleanIdlePools', in 15.00 seconds
2012/03/05 04:29:27.150 kid1| leaving memPoolCleanIdlePools()
2012/03/05 04:29:27.165 kid1| event.cc(252) checkEvents: checkEvents
2012/03/05 04:29:27.165 kid1| The AsyncCall fqdncache_purgelru
constructed, this=0x871ff48 [call206]
2012/03/05 04:29:27.165 kid1| event.cc(261) will call
fqdncache_purgelru() [call206]
2012/03/05 04:29:27.165 kid1| entering fqdncache_purgelru()
2012/03/05 04:29:27.165 kid1| AsyncCall.cc(34) make: make call
fqdncache_purgelru [call206]
2012/03/05 04:29:27.165 kid1| event.cc(344) schedule: schedule: Adding
'fqdncache_purgelru', in 10.00 seconds
2012/03/05 04:29:27.166 kid1| leaving fqdncache_purgelru()
Received on Mon Mar 05 2012 - 18:09:10 MST