CODEWITHSUNDEEP
.htaccessmod-rewriteapache2
user2176640
user2176640

Reputation: 3

htaccess in subbdomain skip redirection rule

I'm trying to let the visitors of my subdomain only direclty in, when using a specific subdomain link format. I know that this would block SEs too, but I don't want the subdomain to be indexed anyway.

The allowed link should look like this:

subdomain.maindomain.com/aaa/bbb/ccc

and should be rewritten to this:

subdomain.maindomain.com/index.php?a=aaa&b=bbb&c=ccc

everthing what's not of this form and coming from an empty or external referrer shall go to the main domain and without the variables:

maindomain.com/

I tried with all kind of configuration, my last .htaccess file in the subdomain folder looks like this:

RewriteEngine on
RewriteRule ^/?(\w{3})/(\w{3})/(\w{3})$ index.php?a=$1&b=$2&c=$3 [S=1,L]

RewriteCond %{HTTP_REFERER} !^http://(www\.)?maindomain\.com [NC]
RewriteRule ^(.*)$ http://domain\.com/ [L]

But it's still not doing what I want, it redirects also request for subdomain of the allowed form to the main domain and it also adds the vars as request to the main domain, going to this page

maindomain.com/?a=aaa&b=bbb&c=cee

Can you help me with the condition defined above.

And a second question, about the performance: I could obviously do this verification / redirect with PHP, what would be more efficient in your opinion?

Thank you!

Upvotes: 0

Views: 273

Answers (2)

Olaf Dietsche
Olaf Dietsche

Reputation: 74128

You're pretty close. You need only a few additional parts

  • The flag S=1 doesn't harm, but is not necessary either.
  • Move the referer condition to the first rule and invert it. You might want to allow for any subdomain as well.
  • Add an additional negative condition to exclude index.php from being redirected to the main domain.
  • You don't use the original request in the substitution in your second rule, so you don't need to capture it.
  • Append a question mark ? to prevent the arguments being forwarded to the main domain.
  • Add an R flag, if you want the client to be redirected and not only the request rewritten.

All parts together 

RewriteEngine on

RewriteCond %{HTTP_REFERER} ^http://(.+\.)?maindomain\.com [NC]
RewriteRule ^(\w{3})/(\w{3})/(\w{3})$ index.php?a=$1&b=$2&c=$3 [L]

RewriteCond %{REQUEST_URI} !$index\.php$
RewriteRule ^ http://domain\.com/? [R,L]

Regarding performance, if you rewrite or redirect with just .htaccess, the job is done before it even hits some PHP script. So, I think it is better to do this with .htaccess.

Upvotes: 0

kjetilh
kjetilh

Reputation: 4976

If I understood your logic correctly please try this:

RewriteEngine on
RewriteBase /

# Don't do any more rewrites if on index.php
# Note that you can add the HTTP_HOST condition here if you only want it to be active for the subdomain
RewriteRule ^index\.php$ - [L]

# If on subdomain then check that the referer is from main domain and attempt to match a regex
# If we find a match then ignore the next rule that rewrites subdomain to domain.com
# Basically this is like an awkward if-else statement..
# ================    

RewriteCond %{HTTP_HOST} ^subdomain\.domain\.com$
RewriteCond %{HTTP_REFERER} ^http://(www\.)?domain\.com [NC]
# Rewrites /aaa/bbb/ccc to /index.php?a=aaa&b=bbb&c=ccc
RewriteRule ^(\w{3})/(\w{3})/(\w{3})$ index.php?a=$1&b=$2&c=$3 [S=1,L]

# Redirect all requests from subdomain to domain.com by default
# ================   

RewriteCond %{HTTP_HOST} ^subdomain\.domain\.com$
# Add the trailing question mark to delete all query parameters
RewriteRule .* http://domain.com/? [L]

Upvotes: 1

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