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LeanderV_365921's avatar
LeanderV_365921
Mar 07, 2019

FTP Proxy : pwd problem

Hello,

 

Im currently using following code snippet for FTP proxy.

 

https://devcentral.f5.com/codeshare/ftp-proxy-lite

 

    when CLIENT_ACCEPTED {
    TCP::respond "220 Welcome to the F5 FTP Proxy\r\n"
    log local0. "client accepted"
    TCP::collect
}

when CLIENT_DATA {
    set ftplogin [TCP::payload]
    if { $ftplogin starts_with "USER" } {
        set cuser [TCP::payload]
        scan $cuser {%[^@]@%s} garbage remote_ftp_site_addr
        scan $garbage %s%s cmd uid
        TCP::payload replace 0 [string length $cuser ] "USER $uid\r\n"
        node $remote_ftp_site_addr [TCP::local_port]
    }
    TCP::release
}
`

But it looks like the passwd doesnt get passed when connecting to the ftp server.
I get this behavior with WINSCP and Filezilla

Answer : 530 Please login with USER and PASS.

Server Log:

> 
`Thu Mar  7 10:13:12 2019 [pid 17174] FTP command: Client "::ffff:130.0.0.150", "USER ictst"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", "331 Please specify the password."
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP command: Client "::ffff:130.0.0.150", "SYST"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", "530 Please login with USER and PASS."
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP command: Client "::ffff:130.0.0.150", "FEAT"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", "211-Features:"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", " EPRT??"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", " EPSV??"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", " MDTM??"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", " PASV??"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", " REST STREAM??"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", " SIZE??"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", " TVFS??"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", "211 End"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP command: Client "::ffff:130.0.0.150", "PWD"
Thu Mar  7 10:13:12 2019 [pid 17174] [ictst] FTP response: Client "::ffff:130.0.0.150", "530 Please login with USER an

The Virtual server has a FTP-Profile on it.

 

Anybody have an idea why this could be the case ?

 

Leander

 

application delivery
BIG-IP
ftp
ftp profile
iRules
LTM
security
  • PeteWhite's avatar
    PeteWhite
    Icon for Employee rankEmployee
    Mar 07, 2019

    Because your user does not have an FTP server included maybe?

     

    FTP command: Client "::ffff:130.0.0.150", "USER ictst"

    But the code requires the user to be of the type username@ip address:

     

    scan $cuser {%[^@]@%s} garbage remote_ftp_site_addr
scan $garbage %s%s cmd uid
TCP::payload replace 0 [string length $cuser ] "USER $uid\r\n"
node $remote_ftp_site_addr [TCP::local_port]
  • LeanderV_365921's avatar
    LeanderV_365921
    Mar 08, 2019

    Hi,

    Sorry i wansn't clear enough. The logs u see there are from the backend FTP-Server. 

    `FTP command: Client "::ffff:130.0.0.150", "USER ictst"`

    So the ftp-connection gets setup with right server based on the username. The irule does what it needs to do. Only we can't complete the connection because it always fails when trying to give the password.

    Leander