Forum Discussion

adamm's avatar
adamm
Icon for Altostratus rankAltostratus
May 23, 2019

Radius Persistence iRule error (bad field specifier)

Having some difficulties implementing a hash persistence irule for Radius auth.   when CLIENT_ACCEPTED { binary scan [UDP::payload] ccSH32cc code ident len auth attr_code1 attr_len1 set in...
application delivery
iRules
LTM
Niels_van_Sluis's avatar
Niels_van_Sluis
Icon for MVP rankMVP

It could be that the ${hsize} variable is being set to a negative integer. This could happen at the first binary scan the attr_len1 variable is being set to 0 or 1.

 

So if attr_len1 is set to 1, then hsize becomes '-2', because (1 -2) * 2 = -2.

 

Could you add an extra log line to your code to see what value is set to the attr_len1 variable?

 

when CLIENT_ACCEPTED {
 binary scan [UDP::payload] ccSH32cc code ident len auth attr_code1 attr_len1
 log local0. "DEBUG: attr_len1 = $attr_len1"
 set index 22
...

 

 

 

 

adamm's avatar
adamm
Icon for Altostratus rankAltostratus
May 28, 2019

That shows the cause of the "-" bad field specifier error:

info tmm[29577]: Rule /Common/Radius_CallingStationId <CLIENT_ACCEPTED>: DEBUG: attr_len1 = 0
err tmm[29577]: 01220001:3: TCL error: /Common/Radius_CallingStationId <CLIENT_ACCEPTED> - bad field specifier "-"     while executing "binary scan [UDP::payload] @${index}H${hsize}cc attr_value next_attr_code2 next_attr_len2"

But there's nothing yet for the other error:

info tmm3[29577]: Rule /Common/Radius_CallingStationId <CLIENT_ACCEPTED>: DEBUG: attr_len1 = 67
err tmm3[29577]: 01220001:3: TCL error: /Common/Radius_CallingStationId <CLIENT_ACCEPTED> - can't read "next_attr_len2": no such variable     while executing "set attr_len1 $next_attr_len2"

Looking for other logging options to figure it out.

  • Lee_Sutcliffe's avatar
    Lee_Sutcliffe
    Icon for Nacreous rankNacreous
    May 29, 2019

    Have you tried putting the binary scan in a catch, it may explain why the $next_attr_len2 variable is not set

    if {[catch {binary scan [UDP::payload] @${index}H${hsize}cc attr_value next_attr_code2 next_attr_len2} catchErr ]} {
    log local0. "binary scan failed! ERROR: $catchErr"
}