On 2014-07-03 12:01, Nyamul Hassan wrote:
Hi,
We are trying to run Squid 3.4.6 with TProxy. Earlier we used to run
Squid 2.7.Stable9 in "transparent" mode with a DNAT rule on the router
box to redirect traffic. This being our first jibe at Squid3, we have
successfully configured "intercept" mode with the router doing a
policy-based routing (instead of DNAT). All works quite well!
However, when we try to do a TProxy configuration, Squid does not seem
to be seeing the traffic at all. Since Squid3 is working in
"intercept" we assume that is not the problem. IPTables is configured
as follows:
*mangle
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
:DIVERT - [0:0]
-A PREROUTING -p tcp -m socket -j DIVERT
-A PREROUTING -p tcp --dport 80 -j LOG --log-prefix "TProxy: "
-A PREROUTING -p tcp --dport 80 -j TPROXY --tproxy-mark 0x1/0x1
--on-port 3129
-A DIVERT -j MARK --set-mark 1
-A DIVERT -j ACCEPT
COMMIT
The Log option shows similar lines as follows (our IP omitted below):
Jul 3 05:15:24 proxy01 kernel: TProxy: IN=eth0 OUT=
MAC=00:22:4d:a7:9a:8c:00:15:17:c8:a0:39:08:00 SRC=<test>
DST=195.93.85.193 LEN=52 TOS=0x00 PREC=0x00 TTL=1 ID=25176 DF
PROTO=TCP SPT=3264 DPT=80 WINDOW=65535 RES=0x00 SYN URGP=0
We also tried both with and without the "IP" commands:
ip rule add fwmark 1 lookup 100
ip route add local default dev eth0 table 100
We have searched through Google, mailing lists, Squid Docs, but seems
like we are still missing through something. One thing though, a lot
of the TProxy examples accompany WCCP or Bridge. Are either of them
mandatory in TProxy setup? If not, could someone help us where we are
doing things wrong?
WCCP and Bridge are optional.
Since your policy routing is working and the syslog shows iptables
working it seems like the traffic should at least be arriving at Squid.
I suggest these steps for troubleshooting:
1) Double-check the "Troubleshooting" section entries on the TPROXY wiki
page to see if you have missed anything simple (like #3 below).
2) run Squid with debug level 11,2 to see what IP:port are being used on
traffic arriving and leaving Squid. This can help confirm the TCP
connections in syslog are correct, and tells you what to look for in #3
below.
3) check the routing rules on traffic once it leaves Squid (using the
serve connection details found in #2). The router often needs additional
policy routing rules for TPROXY to ensure it does not create a loop.
Amos
