Squid allows to include the outer redirector in its configuration. This programme fulfils the function of clients queries filtering.
Every time someone downloads a file through your proxy-server, the query data are sent to the redirector. The redirector analyses the data, if certain conditions are fulfilled it changes sends the answer.
For example, someone's browser sends the query: http://www.mp3.ru/pesna.mp3 10.1.1.10/- - GET
and the redirector, according to the administrator's plan, changes it into: http://10.1.1.1/antimp3.mp3 10.1.1.10/- - GET
The query consists of:
http://www.mp3.ru/pesna.mp3
asked URL
10.1.1.10/-
client ip address/(name of the client host or "-")
-
client login or "-"
GET
URL query method
As a result the user gets an mp3 from the local web-server instead of file he ask for in the Internet.
The more cruel administrator can change all the pictures from the porno sites into the photo of his grinning face :).
We can just change all the advertisements into the transparent GIF 1x1, and instead of porno sites and mp3 sites we'll show the page: "Access denied!".
Wanted
Wanted a large catalog of porn to appending to porno.urls
Wanted
Wanted news feeds "new porn sites" to appending to porno.urls