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pmaubo3_109863's avatar
pmaubo3_109863
Icon for Nimbostratus rankNimbostratus
Feb 08, 2012

X-Forward-For irule

There is an irule in place which was there before I started working at my position.

 

 

See below

 

 

when HTTP_REQUEST {

 

if {[HTTP::header exists X-Forwarded-For]}{

 

HTTP::header replace X-Forwarded-For "[HTTP::header X-Forwarded-For], [getfield [IP::client_addr] % 1]"

 

} else {

 

HTTP::header insert X-Forwarded-For [getfield [IP::client_addr] % 1

 

}

 

}

 

 

However, I do see this message in viewing the log

 

 

invoked from within "HTTP::header replace X-Forwarded-For "[HTTP::header X-Forwarded-For], [getfield [IP::client_addr] % 1]""

 

local/tmm err tmm[5538]: 01220001:3: TCL error: x-forwarded-for_single - Operation not supported (line 1)

 

 

What is the getfield entry do? And is that causing the issue. Does the messages in the logs means the irule is failing all the time.

 

 

The reason I ask is we have one app group who has an intermittent issue with windows times out when they envoke a trade symbol in their application and I've gone through all the configs without having an luck. Could it be possible that this might be causing the issue.

 

 

I do know the below irule would work, just wanted some input from those who are more experienced.

 

 

when HTTP_REQUEST {

 

if {[HTTP::header exists X-Forwarded-For]}{

 

HTTP::header replace X-Forwarded-For "[HTTP::header X-Forwarded-For], [IP::client_addr]"

 

} else {

 

HTTP::header insert X-Forwarded-For [IP::client_addr]

 

}

 

}
application delivery
dev
devops
iRules

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  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Feb 09, 2012
    What is the getfield entry do? And is that causing the issue. Does the messages in the logs means the irule is failing all the time.i guess you are using route domain. getfield is used to remove route domain part from IP::client_addr. 

    [root@ve1023:Active] config  b rule initrule list
rule initrule {
   when RULE_INIT {
        log local0. "\[getfield 1.1.1.1 % 1\]: [getfield 1.1.1.1 % 1]"
        log local0. "\[getfield 1.1.1.1%123 % 1\]: [getfield 1.1.1.1%123 % 1]"
        log local0. "\[getfield 1.1.1.1%123 % 2\]: [getfield 1.1.1.1%123 % 2]"
}
}

[root@ve1023:Active] config  cat /var/log/ltm
Feb  8 22:54:57 local/tmm info tmm[4369]: Rule initrule : [getfield 1.1.1.1 % 1]: 1.1.1.1
Feb  8 22:54:57 local/tmm info tmm[4369]: Rule initrule : [getfield 1.1.1.1%123 % 1]: 1.1.1.1
Feb  8 22:54:57 local/tmm info tmm[4369]: Rule initrule : [getfield 1.1.1.1%123 % 2]: 123
  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Feb 09, 2012
    i do not think the irule fails all the time. it looks okay to me. can you add more log command or capture packet while problem is happening? 

    [root@ve1023:Active] config  b virtual bar list
virtual bar {
   snat automap
   pool foo
   destination 172.28.19.79:80
   ip protocol 6
   rules myrule
   profiles {
      http {}
      tcp {}
   }
}
[root@ve1023:Active] config  b pool foo list
pool foo {
   members 200.200.200.101:80 {}
}
[root@ve1023:Active] config  b rule myrule list
rule myrule {
   when HTTP_REQUEST {
   log local0. "\[getfield \[IP::client_addr\] % 1\]: [getfield [IP::client_addr] % 1]"
   if {[HTTP::header exists X-Forwarded-For]}{
      log local0. "\[HTTP::header X-Forwarded-For\]: [HTTP::header X-Forwarded-For]"
      HTTP::header replace X-Forwarded-For "[HTTP::header X-Forwarded-For], [getfield [IP::client_addr] % 1]"
   } else {
      HTTP::header insert X-Forwarded-For [getfield [IP::client_addr] % 1]
   }
}
}

X-Forwarded-For header exists in request.

[root@ve1023:Active] config  ssldump -Aed -nni 0.0 port 80
New TCP connection 1: 172.28.19.253(43292) <-> 172.28.19.79(80)
1328770680.1202 (0.0030)  C>S
---------------------------------------------------------------
HEAD / HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8r zlib/1.2.3 libidn/0.6.5
Host: 172.28.19.79
Accept: */*
X-Forwarded-For: 1.1.1.1

---------------------------------------------------------------

New TCP connection 2: 200.200.200.10(43292) <-> 200.200.200.101(80)
1328770680.1222 (0.0011)  C>S
---------------------------------------------------------------
HEAD / HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8r zlib/1.2.3 libidn/0.6.5
Host: 172.28.19.79
Accept: */*
X-Forwarded-For: 1.1.1.1, 172.28.19.253

---------------------------------------------------------------

[root@ve1023:Active] config  cat /var/log/ltm
Feb  8 22:57:41 local/tmm notice tmm[4369]: 013e0001:5: Tcpdump starting bcast on :::0 from 127.1.1.1:44072
Feb  8 22:58:00 local/tmm info tmm[4369]: Rule myrule : [getfield [IP::client_addr] % 1]: 172.28.19.253
Feb  8 22:58:00 local/tmm info tmm[4369]: Rule myrule : [HTTP::header X-Forwarded-For]: 1.1.1.1
Feb  8 22:58:03 local/tmm notice tmm[4369]: 013e0002:5: Tcpdump stopping on 127.1.1.2:3936 from 127.1.1.1:44072

X-Forwarded-For does not exist.

[root@ve1023:Active] config  ssldump -Aed -nni 0.0 port 80
New TCP connection 1: 172.28.19.253(43294) <-> 172.28.19.79(80)
1328770729.9791 (0.0019)  C>S
---------------------------------------------------------------
HEAD / HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8r zlib/1.2.3 libidn/0.6.5
Host: 172.28.19.79
Accept: */*

---------------------------------------------------------------

New TCP connection 2: 200.200.200.10(43294) <-> 200.200.200.101(80)
1328770729.9802 (0.0010)  C>S
---------------------------------------------------------------
HEAD / HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8r zlib/1.2.3 libidn/0.6.5
Host: 172.28.19.79
Accept: */*
X-Forwarded-For: 172.28.19.253

---------------------------------------------------------------

[root@ve1023:Active] config  cat /var/log/ltm
Feb  8 22:58:44 local/tmm notice tmm[4369]: 013e0001:5: Tcpdump starting bcast on :::0 from 127.1.1.1:34286
Feb  8 22:58:49 local/tmm info tmm[4369]: Rule myrule : [getfield [IP::client_addr] % 1]: 172.28.19.253
Feb  8 22:58:52 local/tmm notice tmm[4369]: 013e0002:5: Tcpdump stopping on 127.1.1.2:3937 from 127.1.1.1:34286