Se avete configurato il votro Raspberry come router o bridge di rete wifi-ethernet (vedi articolo Raspberry come bridge wifi to ethernet e file server samba), allora possiamo aggiungere facilmente un proxy http trasparente ai servizi che il vostro Raspberry già eroga.
1) installare squid e configurare:
sudo apt-get install squid3 squid3-common
editiamo
sudo nano /etc/squid/squid.conf
e inseriamo un configurazione tipo
http_port 3128 intercept
acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
acl localnet src fc00::/7 # RFC 4193 local private network range
acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines
acl SSL_ports port 443
acl Safe_ports port 80 # http
acl Safe_ports port 21 # ftp
acl Safe_ports port 443 # https
acl Safe_ports port 70 # gopher
acl Safe_ports port 210 # wais
acl Safe_ports port 280 # http-mgmt
acl Safe_ports port 488 # gss-http
acl Safe_ports port 591 # filemaker
acl Safe_ports port 777 # multiling http
acl Safe_ports port 1025-65535 # unregistered ports
acl CONNECT method CONNECT
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow manager localhost
http_access deny manager
#
# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
#
http_access allow localnet
http_access allow localhost
http_access deny all
coredump_dir /var/cache/squid
cache_dir ufs /var/cache/squid 10000 16 256
logfile_rotate 3
refresh_pattern (/cgi-bin/|\?) 0 0% 0
refresh_pattern ^ftp: 1440 20% 10080
refresh_pattern ^gopher: 1440 0% 1440
refresh_pattern -i \.(gif|png|jpg|jpeg|ico)$ 10080 90% 43200 override-expire ignore-no-store ignore-private
refresh_pattern -i \.(ts|avi|wav|mp3|mp4|mpeg|swf|flv|x-flv)$ 43200 90% 432000 override-expire ignore-no-store ignore-private
refresh_pattern -i \.index.(html|htm)$ 0 40% 10080
refresh_pattern -i \.(html|htm|css|js)$ 1440 40% 40320
refresh_pattern . 0 40% 40320
# ANONYMOUS PROXY
forwarded_for off
request_header_access Allow allow all
request_header_access Authorization allow all
request_header_access WWW-Authenticate allow all
request_header_access Proxy-Authorization allow all
request_header_access Proxy-Authenticate allow all
request_header_access Cache-Control allow all
request_header_access Content-Encoding allow all
request_header_access Content-Length allow all
request_header_access Content-Type allow all
request_header_access Date allow all
request_header_access Expires allow all
request_header_access Host allow all
request_header_access If-Modified-Since allow all
request_header_access Last-Modified allow all
request_header_access Location allow all
request_header_access Pragma allow all
request_header_access Accept allow all
request_header_access Accept-Charset allow all
request_header_access Accept-Encoding allow all
request_header_access Accept-Language allow all
request_header_access Content-Language allow all
request_header_access Mime-Version allow all
request_header_access Retry-After allow all
request_header_access Title allow all
request_header_access Connection allow all
request_header_access Proxy-Connection allow all
request_header_access User-Agent allow all
request_header_access Cookie allow all
request_header_access All deny all
se la directory cache non esiste la si può creare:
sudo mkdir /var/cache/squid
sudo chown -R proxy:proxy /var/cache/squid
per essere sicuri che la struttura della cache sia inizializzata eseguiamo:
sudo squid -z
sudo service squid restart
2) configuriamo il kernel al fine di redirigere il traffico http verso il proxy
editiamo
sudo nano /etc/rc.local
e inseriamo
iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-ports 3128
in questo modo verrà eseguito ad ogni avvio. Riavviamo il Raspberry.
Tutti i dispositivi a cui il Raspberry eroga una connessione internet useranno in modo automatico e trasparente la cache del proxy.