For more information regarding the security incident at F5, the actions we are taking to address it, and our ongoing efforts to protect our customers, click here.

Forum Discussion

swabbies_112156's avatar
swabbies_112156
Icon for Nimbostratus rankNimbostratus
Jan 09, 2013

help with syntax for trim command

Hello.

 

I am trying to sort out the correct syntax for using the trim function to get rid of any whitespace at the end of value.

 

 

exsting code: set cmd [ URI::query [string tolower [HTTP::uri]] command ]

 

example uri that works correctly = /interface.asp?command=testfunction&uid=testuser1

 

this then sets "cmd" to "testfunction"

 

 

example uri tdoesn't work because of whitespace = /interface.asp?command=testfunction &uid=testuser1

 

this sets "cmd" to "testfunction%20" and causes issues.

 

 

Would this be the correct syntax? and would this cover requests that have 2 whitespaces in it or only 1?

 

 

set cmd [string trim [URI::query [string tolower [HTTP::uri]] " "] command ]

 

 

Thanks for your help.

 

Ben

 

application delivery
dev
devops
iRules

4 Replies

  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Jan 09, 2013
    Hi Ben,

     

     

    The user-agent should be URI encoding the space into a %20 before sending the HTTP request. String trim works fine when you want to trim any set of individual characters but not a specific sequence. If you want to remove the %20's from a parameter value, you can try this:

     

     

    set cmd [string map {%20 ""} [URI::query [string tolower [HTTP::uri]] " "] command]]

     

     

    Just make sure to test the config load after you make the iRule change using 'b verify load' or 'tmsh load sys config verify'. There have been some parser bugs when loading the config with these types of commands. If you see any issues reply back here and I'll try giving you an alternate format to do the same thing.

     

     

    Aaron
  • swabbies_112156's avatar
    swabbies_112156
    Icon for Nimbostratus rankNimbostratus
    Jan 09, 2013
    Aaron,

     

    Thanks for your help.

     

     

    did you mean to put :

     

    set cmd [string map {%20 ""} [ URI::query [string tolower [HTTP::uri]] command ]]

     

     

    instead of:

     

    set cmd [string map {%20 ""} [URI::query [string tolower [HTTP::uri]] " "] command]]
  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Jan 09, 2013
    i think so. 

    [root@ve10:Active] config  b rule myrule list
rule myrule {
   when RULE_INIT {
  set uri "/interface.asp?command=testfunction%20&uid=testuser1"
  log local0. "\[string map {%20 \"\"} \[URI::query [string tolower $uri] command\]\]=.[string map {%20 ""} [URI::query [string tolower $uri] command]]."
}
}

[root@ve10:Active] config  tail /var/log/ltm
Jan 10 00:28:47 local/tmm info tmm[4884]: Rule myrule : [string map {%20 ""} [URI::query /interface.asp?command=testfunction%20&uid=testuser1 command]]=.testfunction.