mod_alias/146: attemtps to redirect to URIs with no net_loc component fail at startup

["Taso N. Devetzis" <de...@snet.net>]

>Number:         146
>Category:       mod_alias
>Synopsis:       attemtps to redirect to URIs with no net_loc component fail at startup
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    gnats-admin (GNATS administrator)
>State:          open
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Sun Feb  2 03:50:01 1997
>Originator:     devetzis@snet.net
>Organization:
apache
>Release:        1.1.3
>Environment:
SunOS 5.5.1 Generic 103640-03 September 1996 (sun4m sparc)
gcc version 2.7.2.1
>Description:
this fails:

Redirect /foo/bar mailto:mumble@foo.com

reason: add_redirect() (mod_alias.c) calls is_url() (util.c) which fails.
is_url() looks for colon, alpha chars and "//" (net_loc stuff).

i can't see anything in the standards to preclude the above behaviour.
bnf for location header field is (from rfc 1945):

Location       = "Location" ":" absoluteURI

valid absolute identifiers need not contain network location/login components
(rfc 1808).

in fact, the above works with other servers (ibm/ncsa).
>How-To-Repeat:
the redfirect directive above will fail at runtime.
>Fix:
i understand that this has the potential to become a rathole.  i don't know
what, if any, impact on performance futzing with is_url() might have.
for my purposes, the following patch (for 1.1.3) mixes the right level of
idealism and pragmatism (i suppose "telnet:" might be ok as well):

*** util.c.orig Wed Jun 26 06:46:37 1996
--- util.c      Sun Feb  2 05:57:35 1997
***************
*** 792,797 ****
--- 792,800 ----

      if((u[x+1] == '/') && (u[x+2] == '/'))
          return 1;
+     else if (!(strncasecmp (&u[0], "mailto:", 7) &&
+              strncasecmp (&u[0], "news:", 5)))
+         return 1;
      else return 0;
  }

%0
>Audit-Trail:
>Unformatted: