[linux-security] Re: Problem with TCP_wrappers

[wietse porcupine org (Wietse Venema)]

Wietse Venema:
> What is the problem with a non-empty RELAYCLIENT variable?

Jan Kasprzak:
> 	Qmail appends its contents to the envelope destination address,
> so it has to be empty. I hope vmailer will be better :-)
> Again, how can I "setenv" an empty variable in tcp-wrappers?

That would involve two small code changes: one to change the syntax
of the `setenv' option; one change to use an empty string as default.

Untested patch follows; it probably works, but given the structure
of the code it is pretty straightforward to fix if need be.

	Wietse

*** ./options.c-	Thu Aug  6 16:17:52 1998
--- ./options.c	Thu Aug  6 16:19:48 1998
***************
*** 116,122 ****
      "spawn", spawn_option, NEED_ARG | EXPAND_ARG,
      "twist", twist_option, NEED_ARG | EXPAND_ARG | USE_LAST,
      "rfc931", rfc931_option, OPT_ARG,
!     "setenv", setenv_option, NEED_ARG | EXPAND_ARG,
      "nice", nice_option, OPT_ARG,
      "severity", severity_option, NEED_ARG,
      "allow", allow_option, USE_LAST,
--- 116,122 ----
      "spawn", spawn_option, NEED_ARG | EXPAND_ARG,
      "twist", twist_option, NEED_ARG | EXPAND_ARG | USE_LAST,
      "rfc931", rfc931_option, OPT_ARG,
!     "setenv", setenv_option, OPT_ARG | EXPAND_ARG,
      "nice", nice_option, OPT_ARG,
      "severity", severity_option, NEED_ARG,
      "allow", allow_option, USE_LAST,
***************
*** 429,434 ****
--- 429,436 ----
  {
      char   *var_value;
  
+     if (value == 0)
+ 	value = "";
      if (*(var_value = value + strcspn(value, whitespace)))
  	*var_value++ = 0;
      if (setenv(chop_string(value), chop_string(var_value), 1))