Príručka systémového administrátora, 1.9.4

7. Proxy server [UPDATE]

Posledná zmena: 9/1/2007

7.1 Čo je proxy server

Proxy server je špeciálny typ servera - prostredníka v komunikácii, ktorý sa umiestňuje medzi klienta a servery, s ktorými komunikuje. Proxy server sa tvári voči klientovi ako server a voči serveru ako klient. Výhodou je, že proxy server pozná požiadavku klienta a vie mu doručiť odpoveď, aj keď klient samotný nemôže alebo nevie (kvôli obmedzeniam alebo parametrom siete) priamo komunikovať so vzdialeným serverom.

Činnosť proxy servera možno opísať v niekoľkých bodoch:

  1. klient sa spojí s proxy serverom namiesto toho, aby kontaktoval vzdialený server
  2. proxy server prevezme požiadavku klienta, ktorá obsahuje adresu vzdialeného servera, s ktorým chce klient komunikovať
  3. proxy server sa stane klientom, spojí sa so vzdialeným serverom a odovzdá mu požiadavku od svojho klienta
  4. vzdialený server odpovie
  5. proxy server prevezme odpoveď od vzdialeného servera a doručí ju svojmu klientovi

Je výhodné, ak je proces nastavenia klienta pre prácu s proxy serverom pokiaľ možno jednoduchý (v praxi sa nastavuje typ proxy servera, jeho adresa a port, na ktorom pracuje). Existuje dokonca riešenie, pri ktorom sa na strane klienta nenastavuje vôbec nič a všetky požiadavky idú automaticky cez proxy server. Takéto riešenie sa volá "transparentný proxy server".

Situácia bez použitia proxy servera:

  +-------------+   požiadavka                           +--------+
  | klient      |--------------------------------------> | server |
  | (lok. sieť) |<-------------------------------------- |        |
  +-------------+                             odpoveď    +--------+
  

Situácia s použitím proxy servera:

  +-------------+ požiadavka  +--------+ požiadavka      +--------+
  | klient      |-----------> | proxy  |---------------> | server |
  | (lok. sieť) |<----------- | server |<--------------- |        |
  +-------------+   odpoveď   +--------+      odpoveď    +--------+
  

Keďže proxy server pozná klienta, od ktorého prišla požiadavka, môže riadiť prístup k informáciám. Navyše, za určitých okolností (pre isté služby) môže získanú odpoveď nejako spracovať, napríklad si ju zapamätať (cache). Ak dostane tú istú požiadavku od ďalšieho klienta, môže mu poskytnúť odpoveď oveľa rýchlejšie. Toto sa využíva najmä pri cachovaní obsahu WWW stránok.

Rozlišujeme dva druhy proxy serverov:

  1. Aplikačné proxy servery: sú navrhnuté iba pre vybrané sieťové služby, ako napr. http, https, ftp. Výhodou je, že nastavovanie klienta nie je zložité, stačí uviesť adresu proxy servera a jeho port.
  2. SOCKS proxy servery: fungujú pre ľubovoľné služby (TCP?) za predpokladu, že aplikácia podporuje tento typ proxy servera (musí byť špeciálne upravená).

Existujú najmä tieto tri dôvody, prečo nasadiť proxy server v praxi:

7.1.1 Oddelenie sietí - bezpečnosť

Lokálne siete používajú často privátne adresy (napr. 10.0.0.0/255.255.255.0), takže počítače nemôžu komunikovať priamo s Internetom. Používa sa buď preklad adries na firewalli (Network Address Translation - NAT), alebo riešenie pomocou proxy servera. Klient používa proxy server na svojej vlastnej privátnej sieti (má privátnu IP adresu) a ten komunikuje (najčastejšie pomocou iného sieťového pripojenia) s Internetom.

Výhodou použitia proxy servera z hľadiska bezpečnosti teda je:

  1. možno ho použiť na prístup k (určitým službám) Internetu aj v prípade, že klienti používajú privátne adresy (netreba použiť NAT)
  2. možno ho použiť iba na prístup k tým službám, ktoré podporuje proxy server
  3. klient sa pripája na proxy server a nie priamo na server - takže nekomunikuje priamo s vonkajšou sieťou, čím sa dosahuje vyššia bezpečnosť, lebo nemožno zneužiť prebiehajúce spojenie na útok smerujúci zo servera na klienta.

Prirodzene, riešenie má aj svoje nevýhody:

  1. možno ho použiť iba na prístup k tým službám, ktoré podporuje proxy server (toto je výhoda aj nevýhoda zároveň, podľa toho, z akého uhla sa na vec pozeráte)
  2. ak používate aplikačný proxy server, spracovanie aplikačnej vrstvy modelu OSI (bežné sieťové protokoly založené na TCP), do komunikácie vnáša isté spomalenie (proxy musí analyzovať najvrchnejšiu vrstvu modelu OSI)

Treba poznamenať, že pre niektoré siete je použitie prístupu pomocou proxy servera jedinou možnosťou prístupu na Internet. Neskôr sa dozviete, ako sa to dá využiť na riadenie prístupu.

Odporúčania:

Ak použijete proxy server, vzdialený server nekomunikuje priamo s klientom, takže nemôže proti nemu podniknúť útok, môže však zneužiť spojenie so samotným proxy serverom. Tento treba preto čo najlepšie zabezpečiť (pomocou firewallu):

7.1.2 Cache pre obsah (WWW) - rýchlosť odozvy

Ako som spomenul, niektoré typy aplikačných proxy serverov (napr. HTTP proxy) môžu disponovať cache pamäťou, v ktorej určitý čas uchovávajú odpovede serverov a obsah tejto pamäte je k dispozícii pre ďalšie požiadavky. Ak proxy server nájde požadovanú odpoveď v cache, vie odpovedať klientovi rýchlejšie, ako keby musel odpoveď opäť získať. To je výhodné najmä v prípade, že pripojenie na Internet nie je veľmi rýchle, kým rýchlosť na lokálnej sieti dosahuje dnes bežne 100Mb/s.

Mohlo by sa zdať, že hlavnou výhodou je teda menší čas odozvy na požiadavku klienta, čo je aj pravda - ale iba v prípade, že sa odpoveď nachádza v cache. Jej veľkosť je totiž vždy obmedzená (okrem fyzickej pamäti sa používa aj disk). Aby sa do cache mohli ukladať údaje, musí sa z nej niečo odstrániť. Na to existuje niekoľko algoritmov, napr. odstránia sa najmenej používané údaje. Najrýchlejšiu odozvu na požiadavku dosiahnete pomocou proxy servera vtedy, ak budete napríklad v prípade HTTP proxy pristupovať na najčastejšie používané stránky.

Výhoda použitia proxy servera teda je:

  1. zmenšenie času odozvy ("vyššia rýchlosť") pre najčastejšie požiadavky (nachádzajú sa v cache)

Nevýhody:

  1. obmedzená veľkosť cache: podľa Murphyho zákonov sa môže stať, že práve vaša požiadavka sa v cache nenachádza, resp. bola odstránená tesne pred tým, ako ste ju potrebovali ;)
  2. limit na minimálnu a maximálnu veľkosť cachovanného objektu: môže sa stať, že to, čo potrebujete, sa kvôli veľkosti nebude vôbec uchovávať

Pre lepšiu predstavu, ako približne funguje cachujúci proxy server pre WWW stránky, ponúkam tento model. Požiadavkou je URL, ktorú klient požaduje od proxy servera:

Nachádza sa stránka v cache pamäti?

Proxy servery s cache sa používajú takmer výhradne na uchovávanie obsahu WWW stránok a preto sa odteraz budeme venovať iba nim.

7.1.3 Riadenie prístupu

Ak zabezpečíte, že všetky klientské počítače vo vašej sieti budú používať proxy server (pod Windows 9x sa to dá dosiahnuť iba pomocou zásahov do Registrov), stane sa jediným "úzkym hrdlom" komunikácie medzi klientom a serverom. Vznikne tak miesto v sieti, kde môžete pomocou pravidiel regulovať prístup k Internetu.

Výhody použitia proxy servera:

  1. možnosť nasadenia a vynucovania bezpečnostnej politiky z hľadiska prístupu k Internetu - napr. k určitým WWW stránkam
  2. jednoduché nastavenie bez nutnosti nastavovať politiky na všetkých klientoch

Nevýhody:

  1. výkon proxy servera má vplyv na rýchlosť prevádzky (čas odozvy na požiadavku)
  2. vzniká rizikové miesto na sieti ("single point of failure") - v prípade výpadku proxy servera sa nemožno dostať na Internet (toto možno riešiť pomocou viacerých proxy serverov v clustri, ale iba v prípade, že si môžete dovoliť mať viacero serverov)

7.2 Proxy server "Squid"

Predchádzajúce tri možnosti využitia proxy servera si predstavíme na populárnom a kvalitnom open-source proxy serveri pre cachovanie WWW stránok. Jeho meno je Squid (http://www.squid-cache.org).

Squid umožňuje klientom pracovať s protokolmi HTTP, HTTPS, FTP a podporuje aj niekoľko ďalších, menej používaných aplikačných protokolov.

Pred inštaláciou Squida si uvedomte, že prevažná časť činnosti proxy servera spočíva v uchovávaní objektov v pamäti a na disku. Čím viac budete mať pamäte (odporúčam najmenej 128 MB), tým rýchlejší bude Váš proxy server. Ak sa údaje budú uchovávať na disku, rýchlosť diskov rapídne ovplyvní výkon proxy servera. Používajte preto čo najrýchlejšie disky (SCSI alebo rýchle IDE, najlepšie je použiť RAID).

7.2.1 Spúšťanie a zastavovanie Squida

Squid sa spúšťa automaticky pri štarte systému v niektorom runleveli, pretože nemá význam to robiť ručne. Čo však význam určite má, je jeho ovládanie z príkazového riadku v prípade údržby, upgrade, zmeny konfigurácie a podobne.

Ak používate "init" skripty, všetky operácie sú celkom jednoduché.

Ak "init" skripty nepoužívate, operácie sú len trošku odlišné (cesta závisí od inštalácie Squida):

Poznámka: "init" skripty sú iba rozhraním k ovládaniu Squida pomocou príkazového riadku. Môžete sa o tom presvedčiť preštudovaním "init" skriptu "/etc/init.d/squid".

7.2.2 Inicializácia adresárovej štruktúry cache

Po nainštalovaní Squida treba vytvoriť adresárovú štruktúru, v ktorej Squid uchováva obsah svojej cache (cachované súbory). Niektoré distribúcie vytvoria túto štruktúru automaticky pri inštalácii alebo prvom spustení (napr. Mandrake 9.0), ak to však nie je Váš prípad alebo ste Squid kompilovali zo zdrojových textov, musíte to spraviť ručne. Našťastie ide iba o jediný príkaz:

/usr/sbin/squid -z

Výsledkom je vytvorenie adresárovej štruktúry v adresári, ktorý ste uviedli v konfiguračnom súbore "/etc/squid.conf" (v niektorých distribúciách "/etc/squid/squid.conf"), štandardne je to "/var/spool/squid".

7.2.3 Konfiguračný súbor "/etc/squid.conf" ("/etc/squid/squid.conf")

Konfiguračný súbor obsahuje direktívy pre Squid. Každý riadok má tvar:

direktíva hodnota1 [hodnota2 hodnota3 ... hodnotaN]

Mnoho direktív má nastavené implicitné hodnoty, takže ich nemusíte ani odkomentovať (o tomto vás vždy informuje pokec v príslušnej časti konfiguračného súboru "squid.conf").

Súbor je veľmi dobre komentovaný a vrelo odporúčam prečítať si ho celý (pozor, je dosť veľký). Väčšina vecí je už nastavená a dokonca správne, ale parametre týkajúce sa zabezpečenia a nastavenia vlastností cache si musíte nastaviť sami. Ak to neurobíte, implicitné nastavenie proxy servera zabraňuje pripojenie používateľom z akejkoľvek adresy okrem "127.0.0.1".

7.2.3.1 Nastavenia siete (sekcia NETWORK OPTIONS)

Nasledujúce nastavenia umožňujú určiť porty, na ktorých počúva Squid. Čím menej portov je otvorených, tým je nižšie riziko ich zneužitia. Niekoľko týchto portov väčšinou nepotrebujete, takže ich môžete zakázať.

7.2.3.2 Nastavenia cache (sekcia OPTIONS WHICH AFFECT THE CACHE SIZE)

Pomocou týchto nastavení môžete ovplyvniť veľkosť diskovej cache, objekty, ktoré sa nemajú uchovávať v cache a algoritmus odstraňovania objektov z cache v prípade, že treba uložiť nové objekty.

7.2.3.3 Cesty k logom a cache (sekcia LOGFILE PATHNAMES AND CACHE DIRECTORIES)

Táto sekcia obsahuje nastavenia pre cesty k logom Squida a k adresáru so samotnou cache. Štandardné miesto pre uloženie cache je v adresári "/var/spool/squid", kde si pri prvom spustení vytvorí adresárovú štruktúru na uchovávanie cachovaných objektov. Je veľmi vhodné, ak je tento adresár (alebo "/var") na samostatnej partícii, ako sme o tom hovorili v kapitole "Rozdelenie disku".

7.2.3.4 Vyladenie cache (sekcia: OPTIONS FOR TUNING THE CACHE)

7.2.3.5 Riadenie prístupu pomocou ACL (access control lists)

Na kontrolu prístupu slúžia v nastavení Squida zoznamy na kontrolu prístupu (ACL - Access Control Lists). V ďalšom budem používať anglickú skratku ACL, ktorá je jednoduchá a najmä - je to skratka.

Každý ACL sa skladá najmenej zo štyroch častí:

acl meno typ hodnota ...
acl meno typ "súbor" ...
  1. direktíva acl
  2. meno ACL (budete sa naň odvolávať pri samotnom riadení prístupu)
  3. typ ACL (určuje, čo budete kontrolovať, napr. zdrojovú adresu, cieľovú adresu atď.)
  4. hodnota, prípadne viacero hodnôt. Hodnota je uvedená ako reťazec, prípadne môžete uviesť meno súboru v úvodzovkách - súbor musí byť obyčajný textový súbor, v ktorom každý riadok obsahuje jednu hodnotu.

Nasleduje zoznam najpoužívanejších typov ACL s uvedením ich syntaxe a krátkym popisom. Vynechal som len tie ACL, s ktorými som sa v praxi zatiaľ nestretol, všetky sú komentované v konfiguračnom súbore "/etc/squid.conf". Pripomínam, že cieľová adresa znamená adresa (HTTP) servera, zdrojová adresa je adresa klientského počítača, ktorý žiada od proxy servera sprístupnenie WWW stránky na danej cieľovej adrese.

Príklady:

acl localnet src 10.0.0.0/255.255.255.0
acl localnet src 10.0.0.0/255.255.255.0 192.168.0.0/255.255.255.0
definuje ACL s názvom "localnet" pre zdrojové adresy 10.0.0.0/255.255.255.0 (v druhom príklade navyše aj 192.168.0.0/255.255.255.0) - toto ACL použijeme pre definíciu adries z lokálnej siete
acl forbiddenpages dstdomain www.foo.com
acl forbiddenpages dstdomain www.foo.com www.foobar.com
definuje ACL s názvom "forbiddenpages" pre cieľovú adresu "www.foo.com" - toto ACL použijeme pre definíciu "zakázanej" stránky (v druhom príklade definujeme v tomto ACL aj druhú adresu "www.foobar.com"
acl day1 time M 8:00-16:00
definuje ACL s názvom "day1" pre čas 8:00 - 16:00 v pondelok - toto ACL použijeme na zakázanie istých stránok počas pracovných hodín v pondelok. Analogicky definujeme aj iné dni.
acl day2 time T 8:00-16:00
acl day3 time W 8:00-16:00
acl day4 time H 8:00-16:00
acl day5 time F 8:00-16:00
ako predchádzajúce ACL, pre ostatné dni

Ukážka (odporúčanie) minimálnej konfigurácie od autorov Squida, viacmenej na ukážku ďalších ACL:

  #Recommended minimum configuration:
  acl all src 0.0.0.0/0.0.0.0
  acl manager proto cache_object
  acl localhost src 127.0.0.1/255.255.255.255
  acl SSL_ports port 443 563
  acl Safe_ports port 80		# http
  acl Safe_ports port 21		# ftp
  acl Safe_ports port 443 563	# https, snews
  acl Safe_ports port 70		# gopher
  acl Safe_ports port 210		# wais
  acl Safe_ports port 1025-65535	# unregistered ports
  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 CONNECT method CONNECT

Poznámka: ACL "Safe_ports" má rovnakú hodnotu, ako by boli všetky hodnoty uvedené v jednom ACL na jednom riadku.

Na samotné riadenie prístupu slúžia direktívy "http_acces" v tvare:

http_access allow|deny [!]aclname ...

Na poradí direktív "http_access" záleží! Ak požiadavka na sprístupnenie nejakej stránky vyhovie niektorej z direktív, je povolená alebo zamietnutá. Preto je dôležité uvedomiť si dve zásady:

Odporúčaná minimálna konfigurácia od autorov Squida:

  #Recommended minimum configuration:
  #
  # Only allow cachemgr access from localhost
  http_access allow manager localhost
  http_access deny manager
  # Deny requests to unknown ports
  http_access deny !Safe_ports
  # Deny CONNECT to other than SSL ports
  http_access deny CONNECT !SSL_ports
  #
  # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
  #
  # And finally deny all other access to this proxy
  http_access allow localhost
  http_access deny all

Všimnite si, že štandardné rozhodnutie "http_access deny all" spolu s "http_access allow localhost" umožní použitie proxy servera iba pre procesy, ktoré na ňom bežia. To nie je práve želaná konfigurácia, ale presne vystihuje základné bezpečnostné pravidlo "čo nie je povolené, je zakázané."

Upravená minimálna konfigurácia:

  #Recommended minimum configuration:
  #
  # Only allow cachemgr access from localhost
  http_access allow manager localhost
  http_access deny manager
  # Deny requests to unknown ports
  http_access deny !Safe_ports
  # Deny CONNECT to other than SSL ports
  http_access deny CONNECT !SSL_ports
  #
  # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS

  http_access allow localnet
  
  # And finally deny all other access to this proxy
  http_access allow localhost
  http_access deny all

Upravená minimálna konfigurácia s našimi ACL z príkladov:

  #Recommended minimum configuration:
  #
  # Only allow cachemgr access from localhost
  http_access allow manager localhost
  http_access deny manager
  # Deny requests to unknown ports
  http_access deny !Safe_ports
  # Deny CONNECT to other than SSL ports
  http_access deny CONNECT !SSL_ports
  #
  # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS

  
  http_access deny forbiddenpages
  http_access allow localnet
  
  # And finally deny all other access to this proxy
  http_access allow localhost
  http_access deny all

Všimnite si, že direktívu "http_access deny forbiddenpages" sme vložili PRED direktívu povoľujúcu všetky pripojenia z vnútornej siete ("http_access allow localnet")! Na poradí spracovania záleží a takto sme dosiahli presne to, čo sme chceli: používatelia vo vnútornej sieti (definovanej pomocou ACL "localnet") môžu používať proxy server na prístup k ľubovoľným stránkam okrem tých, ktoré sme zablokovali.

Upravená minimálna konfigurácia s pridanými ACL pre riadenie prístupu k stránkam na základe času:

  #Recommended minimum configuration:
  #
  # Only allow cachemgr access from localhost
  http_access allow manager localhost
  http_access deny manager
  # Deny requests to unknown ports
  http_access deny !Safe_ports
  # Deny CONNECT to other than SSL ports
  http_access deny CONNECT !SSL_ports
  #
  # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS

  
  http_access deny day1 forbiddenpages
  http_access deny day2 forbiddenpages
  http_access deny day3 forbiddenpages
  http_access deny day4 forbiddenpages
  http_access deny day5 forbiddenpages
  http_access allow localnet
  
  # And finally deny all other access to this proxy
  http_access allow localhost
  http_access deny all

Predchádzajúca konfigurácia znemožní prístup na stránky uvedené v ACL "forbiddenpages" v prípade, že používateľ žiada ich sprístupnenie počas pracovného týždňa (pondelok-piatok) v čase 8:00-16:00.

Poznámka: ak Vás zaráža, prečo som použil 5 direktív namiesto jednej "http_access deny day1 day2 day3 day4 day5 forbiddenpages": je to preto, že medzi hodnotami "http_access" sa vykonáva operácia "AND". V preklade to znamená, že by musel byť súčasne pondelok, utorok, streda, štvrtok, piatok, čas 8:00-16:00 a stránka z ACL "forbiddenpages".

7.2.3.6 Ďalšie nastavenia [UPDATE]

Tieto direktívy nastavujú rozličné administratívne parametre.

7.2.4 Ukážka reálneho súboru "squid.conf"

Pozor!!!
V nijakom prípade nepoužite tento konfiguračný súbor bez predchádzajúcej úpravy!!! Obsahuje adresy a údaje platné pre www.vazka.sk!

TODO: pridať komentáre aj do tohto výpisu

#	WELCOME TO SQUID 2
#	------------------
#
#	This is the default Squid configuration file. You may wish
#	to look at http://cache.is.co.za/squid/ for documentation,
#	or the Squid home page (http://squid.nlanr.net/) for the FAQ.
#
#	The default Squid config file shows what the defaults for
#	various options happen to be.  If you don't need to change the
#	default, you shouldn't uncomment the line.  Doing so may cause
#	run-time problems.  In some cases "none" refers to no default
#	setting at all, whilst in other cases it refers to a valid
#	option - the comments for that keyword indicate if this is the
#	case.
#
# NETWORK OPTIONS
# -----------------------------------------------------------------------------

#  TAG: http_port
#	The port number where Squid will listen for HTTP client
#	requests.  Default is 3128, for httpd-accel mode use port 80.
#	May be overridden with -a on the command line.
#
#	You may specify multiple ports here, but they MUST all be on
#	a single line.
#
http_port 3128

#  TAG: icp_port
#	The port number where Squid sends and receives ICP requests to
#	and from neighbor caches.  Default is 3130.  To disable use
#	"0".  May be overridden with -u on the command line.
#
#icp_port 3130
icp_port 0

#  TAG: htcp_port
#	The port number where Squid sends and receives ICP requests to
#	and from neighbor caches.  Default is 4827.  To disable use
#	"0".
#
#	To enable this option, you must use --enable-htcp with the
#	configure script.
#htcp_port 0

#  TAG: mcast_groups
#	This tag specifies a list of multicast groups which your server
#	should join to receive multicasted ICP requests.
#
#	NOTE!  Be very careful what you put here!  Be sure you
#	understand the difference between an ICP _query_ and an ICP
#	_reply_.  This option is to be set only if you want to RECEIVE
#	multicast queries.  Do NOT set this option to SEND multicast
#	ICP (use cache_peer for that).  ICP replies are always sent via
#	unicast, so this option does not affect whether or not you will
#	receive replies from multicast group members.
#
#	You must be very careful to NOT use a multicast address which
#	is already in use by another group of caches.  NLANR has been
#	assigned a block of multicast address space for use in Web
#	Caching.  Plese write to us at nlanr-cache@nlanr.net to receive
#	an address for your own use.
#
#	If you are unsure about multicast, please read the Multicast
#	chapter in the Squid FAQ (http://squid.nlanr.net/Squid/FAQ/).
#
#	Usage: mcast_groups 239.128.16.128 224.0.1.20
#
#	By default, Squid doesn't listen on any multicast groups.
#
#mcast_groups 239.128.16.128

#  TAG: tcp_incoming_address
#  TAG: tcp_outgoing_address
#  TAG: udp_incoming_address
#  TAG: udp_outgoing_address
#	Usage: tcp_incoming_address 10.20.30.40
#	       udp_outgoing_address fully.qualified.domain.name
#
#	tcp_incoming_address	is used for the HTTP socket which accepts
#				connections from clients and other caches.
#	tcp_outgoing_address	is used for connections made to remote
#				servers and other caches.
#	udp_incoming_address	is used for the ICP socket receiving packets
#				from other caches.
#	udp_outgoing_address	is used for ICP packets sent out to other
#				caches.
#
#	The default behaviour is to not bind to any specific address.
#
#	NOTE, udp_incoming_address and udp_outgoing_address can not
#	have the same value (unless it is 0.0.0.0) since they both use
#	port 3130.
#
#tcp_incoming_address 0.0.0.0
#tcp_outgoing_address 0.0.0.0
#udp_incoming_address 0.0.0.0
#udp_outgoing_address 0.0.0.0


# OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
# -----------------------------------------------------------------------------

#  TAG: cache_peer
#	To specify other caches in a hierarchy, use the format:
#
#		hostname type http_port icp_port
#
#	For example,
#
#	#                                        proxy  icp
#	#          hostname             type     port   port  options
#	#          -------------------- -------- ----- -----  -----------
#	cache_peer parent.foo.net       parent    3128  3130  [proxy-only]
#	cache_peer sib1.foo.net         sibling   3128  3130  [proxy-only]
#	cache_peer sib2.foo.net         sibling   3128  3130  [proxy-only]
#
#	      type:  either 'parent', 'sibling', or 'multicast'.
#
#	proxy_port:  The port number where the cache listens for proxy
#		     requests.
#
#	  icp_port:  Used for querying neighbor caches about
#		     objects.  To have a non-ICP neighbor
#		     specify '7' for the ICP port and make sure the
#		     neighbor machine has the UDP echo port
#		     enabled in its /etc/inetd.conf file.
#
#	    options: proxy-only
#		     weight=n
#		     ttl=n
#		     no-query
#		     default
#		     round-robin
#		     multicast-responder
#		     closest-only
#		     no-digest
#		     no-netdb-exchange
#		     no-delay
#		     login=user:password
#
#		     use 'proxy-only' to specify that objects fetched
#		     from this cache should not be saved locally.
#
#		     use 'weight=n' to specify a weighted parent.
#		     The weight must be an integer.  The default weight
#		     is 1, larger weights are favored more.
#
#		     use 'ttl=n' to specify a IP multicast TTL to use
#		     when sending an ICP request to this address.
#		     Only useful when sending to a multicast group.
#		     Because we don't accept ICP replies from random
#		     hosts, you must configure other group members as
#		     peers with the 'multicast-responder' option below.
#
#		     use 'no-query' to NOT send ICP queries to this
#		     neighbor.
#
#		     use 'default' if this is a parent cache which can
#		     be used as a "last-resort." You should probably
#		     only use 'default' in situations where you cannot
#		     use ICP with your parent cache(s).
#
#		     use 'round-robin' to define a set of parents which
#		     should be used in a round-robin fashion in the
#		     absence of any ICP queries.
#
#		     'multicast-responder' indicates that the named peer
#		     is a member of a multicast group.  ICP queries will
#		     not be sent directly to the peer, but ICP replies
#		     will be accepted from it.
#
#		     'closest-only' indicates that, for ICP_OP_MISS
#		     replies, we'll only forward CLOSEST_PARENT_MISSes
#		     and never FIRST_PARENT_MISSes.
#
#		     use 'no-digest' to NOT request cache digests from
#		     this neighbor.
#
#		     'no-netdb-exchange' disables requesting ICMP
#		     RTT database (NetDB) from the neighbor.
#
#		     use 'no-delay' to prevent access to this neighbor
#		     from influencing the delay pools.
#
#		     use 'login=user:password' if this is a personal/workgroup
#		     proxy and your parent requires proxy authentication.
#
#	NOTE: non-ICP neighbors must be specified as 'parent'.
#
#cache_peer hostname type 3128 3130

#  TAG: cache_peer_domain
#	Use to limit the domains for which a neighbor cache will be
#	queried.  Usage:
#
#	cache_peer_domain cache-host domain [domain ...]
#	cache_peer_domain cache-host !domain
#
#	For example, specifying
#
#		cache_peer_domain parent.foo.net	.edu
#
#	has the effect such that UDP query packets are sent to
#	'bigserver' only when the requested object exists on a
#	server in the .edu domain.  Prefixing the domainname
#	with '!' means that the cache will be queried for objects
#	NOT in that domain.
#
#	NOTE:	* Any number of domains may be given for a cache-host,
#		  either on the same or separate lines.
#		* When multiple domains are given for a particular
#		  cache-host, the first matched domain is applied.
#		* Cache hosts with no domain restrictions are queried
#		  for all requests.
#		* There are no defaults.
#		* There is also a 'cache_peer_access' tag in the ACL
#		  section.

#  TAG: neighbor_type_domain
#	usage: neighbor_type_domain parent|sibling domain domain ...
#
#	Modifying the neighbor type for specific domains is now
#	possible.  You can treat some domains differently than the the
#	default neighbor type specified on the 'cache_peer' line.
#	Normally it should only be necessary to list domains which
#	should be treated differently because the default neighbor type
#	applies for hostnames which do not match domains listed here.
#
#EXAMPLE:
#	cache_peer  parent cache.foo.org 3128 3130
#	neighbor_type_domain cache.foo.org sibling .com .net
#	neighbor_type_domain cache.foo.org sibling .au .de

#  TAG: icp_query_timeout	(msec)
#	Normally Squid will automatically determine an optimal ICP
#	query timeout value based on the round-trip-time of recent ICP
#	queries.  If you want to override the value determined by
#	Squid, set this 'icp_query_timeout' to a non-zero value.  This
#	value is specified in MILLISECONDS, so, to use a 2-second
#	timeout (the old default), you would write:
#
#		icp_query_timeout 2000
#
#icp_query_timeout 0

#  TAG: mcast_icp_query_timeout	(msec)
#	For Multicast peers, Squid regularly sends out ICP "probes" to
#	count how many other peers are listening on the given multicast
#	address.  This value specifies how long Squid should wait to
#	count all the replies.  The default is 2000 msec, or 2
#	seconds.
#
#mcast_icp_query_timeout 2000

#  TAG: dead_peer_timeout	(seconds)
#	This controls how long Squid waits to declare a peer cache
#	as "dead."  If there are no ICP replies received in this
#	amount of time, Squid will declare the peer dead and not
#	expect to receive any further ICP replies.  However, it
#	continues to send ICP queries, and will mark the peer as
#	alive upon receipt of the first subsequent ICP reply.
#
#	This timeout also affects when Squid expects to receive ICP
#	replies from peers.  If more than 'dead_peer' seconds have
#	passed since the last ICP reply was received, Squid will not
#	expect to receive an ICP reply on the next query.  Thus, if
#	your time between requests is greater than this timeout, you
#	will see a lot of requests sent DIRECT to origin servers
#	instead of to your parents.
#
#dead_peer_timeout 10 seconds

#  TAG: hierarchy_stoplist
#	A list of words which, if found in a URL, cause the object to
#	be handled directly by this cache.  In other words, use this
#	to not query neighbor caches for certain objects.  You may
#	list this option multiple times.
#
#	The default is to directly fetch URLs containing 'cgi-bin' or '?'.
#
hierarchy_stoplist cgi-bin ?

#  TAG: no_cache
#	A list of ACL elements which, if matched, cause the reply to
#	immediately removed from the cache.  In other words, use this
#	to force certain objects to never be cached.
#
#	You must use the word 'DENY' to indicate the ACL names which should
#	NOT be cached.
#
#	There is no default.  We recommend you uncomment the following
#	two lines.
#
acl QUERY urlpath_regex cgi-bin \?
no_cache deny QUERY


# OPTIONS WHICH AFFECT THE CACHE SIZE
# -----------------------------------------------------------------------------

#  TAG: cache_mem	(bytes)
#	NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS
#	SIZE.  IT PLACES A LIMIT ON ONE ASPECT OF SQUID'S MEMORY
#	USAGE.  SQUID USES MEMORY FOR OTHER THINGS AS WELL.
#	YOUR PROCESS WILL PROBABLY BECOME TWICE OR THREE TIMES
#	BIGGER THAN THE VALUE YOU PUT HERE 
#
#	'cache_mem' specifies the ideal amount of memory to be used
#	for:
#		* In-Transit objects
#		* Hot Objects
#		* Negative-Cached objects
#
#	Data for these objects are stored in 4 KB blocks.  This
#	parameter specifies the ideal upper limit on the total size of
#	4 KB blocks allocated.  In-Transit objects take the highest
#	priority.
#
#	In-transit objects have priority over the others.  When
#	additional space is needed for incoming data, negative-cached
#	and hot objects will be released.  In other words, the
#	negative-cached and hot objects will fill up any unused space
#	not needed for in-transit objects.
#
#	If circumstances require, this limit will be exceeded.
#	Specifically, if your incoming request rate requires more than
#	'cache_mem' of memory to hold in-transit objects, Squid will
#	exceed this limit to satisfy the new requests.  When the load
#	decreases, blocks will be freed until the high-water mark is
#	reached.  Thereafter, blocks will be used to store hot
#	objects.
#
#	The values of cache_mem_low and cache_mem_high (below) can be
#	used to tune the use of the memory pool.  When the high mark is
#	reached, in-transit and hot objects will be released to clear
#	space.  When an object transfer is completed, it will remain in
#	memory only if the current memory usage is below the low water
#	mark.
#
#	The default is 8 Megabytes.
#
cache_mem  12 MB

#  TAG: cache_swap_low	(percent, 0-100)
#  TAG: cache_swap_high	(percent, 0-100)
#	The low- and high-water marks for cache LRU replacement.  LRU
#	replacement begins when the high-water mark is reached and ends
#	when enough objects have been removed and the low-water mark is
#	reached. Defaults are 90% and 95%. If you have a large cache, 5%
#	could be hundreds of MB. If this is the case you may wish to
#	set these numbers closer together.
#
cache_swap_low  90
cache_swap_high 95

#  TAG: maximum_object_size	(bytes)
#	Objects larger than this size will NOT be saved on disk.  The
#	value is specified in kilobytes, and the default is 4MB.  If
#	you wish to get a high BYTES hit ratio, you should probably
#	increase this (one 32 MB object hit counts for 3200 10KB
#	hits).  If you wish to increase speed more than your want to
#	save bandwidth you should leave this low.
#
maximum_object_size 8192 KB

#  TAG: ipcache_size	(number of entries)
#  TAG: ipcache_low	(percent)
#  TAG: ipcache_high	(percent)
#	The size, low-, and high-water marks for the IP cache.
#
ipcache_size 1024
ipcache_low  90
ipcache_high 95

#  TAG: fqdncache_size	(number of entries)
#	Maximum number of FQDN cache entries.
fqdncache_size 1024


# LOGFILE PATHNAMES AND CACHE DIRECTORIES
# -----------------------------------------------------------------------------

#  TAG: cache_dir
#	Usage:
#	
#	cache_dir Directory-Name Mbytes Level-1 Level2
#
#	You can specify multiple cache_dir lines to spread the
#	cache among different disk partitions.
#
#	'Directory' is a top-level directory where cache swap
#	files will be stored.  If you want to use an entire disk
#	for caching, then this can be the mount-point directory.
#	The directory must exist and be writable by the Squid
#	process.  Squid will NOT create this directory for you.
#
#	If no 'cache_dir' lines are specified, the following
#	default will be used: /var/spool/squid.
#
#	'Mbytes' is the amount of disk space (MB) to use under this
#	directory.  The default is 100 MB.  Change this to suit your
#	configuration.
#
#	'Level-1' is the number of first-level subdirectories which
#	will be created under the 'Directory'.  The default is 16.
#
#	'Level-2' is the number of second-level subdirectories which
#	will be created under each first-level directory.  The default
#	is 256.
#
cache_dir ufs /var/spool/squid 640 16 256

#  TAG: cache_access_log
#	Logs the client request activity.  Contains an entry for
#	every HTTP and ICP request received.
#
cache_access_log /var/log/squid/access.log

#  TAG: cache_log
#	Cache logging file. This is where general information about
#	your cache's behaviour goes. You can increase the amount of data
#	logged to this file with the "debug_options" tag below.
#
cache_log /var/log/squid/cache.log

#  TAG: cache_store_log
#	Logs the activities of the storage manager.  Shows which
#	objects are ejected from the cache, and which objects are
#	saved and for how long.  To disable, enter "none". There are
#	not really utilities to analyse this data, so you can safely
#	disable it.
#
#cache_store_log /var/log/squid/store.log
cache_store_log none

#  TAG: cache_swap_log
#	Location for the cache "swap.log."  This log file holds the
#	metadata of objects saved on disk.  It is used to rebuild the
#	cache during startup.  Normally this file resides in the first
#	'cache_dir' directory, but you may specify an alternate
#	pathname here.  Note you must give a full filename, not just
#	a directory. Since this is the index for the whole object
#	list you CANNOT periodically rotate it!
#
#	If you have more than one 'cache_dir', these swap logs will
#	have names such as:
#
#		cache_swap_log.00
#		cache_swap_log.01
#		cache_swap_log.02
#
#	The numbered extension (which is added automatically)
#	corresponds to the order of the 'cache_dir' lines in this
#	configuration file.  If you change the order of the 'cache_dir'
#	lines in this file, then these log files will NOT correspond to
#	the correct 'cache_dir' entry (unless you manually rename
#	them).  We recommend that you do NOT use this option.  It is
#	better to keep these log files in each 'cache_dir' directory.
#
#cache_swap_log

#  TAG: emulate_httpd_log	on|off
#	The Cache can emulate the log file format which many 'httpd'
#	programs use.  To disable/enable this emulation, set
#	emulate_httpd_log to 'off' or 'on'.  The default
#	is to use the native log format since it includes useful
#	information that Squid-specific log analysers use.
#
emulate_httpd_log off

#  TAG: mime_table
#	Pathname to Squid's MIME table. You shouldn't need to change
#	this, but the default file contains examples and formatting
#	information if you do.
#
mime_table /usr/lib/squid/mime.conf

#  TAG: log_mime_hdrs	on|off
#	The Cache can record both the request and the response MIME
#	headers for each HTTP transaction.  The headers are encoded
#	safely and will appear as two bracketed fields at the end of
#	the access log (for either the native or httpd-emulated log
#	formats).  To enable this logging set log_mime_hdrs to 'on'.
#
#log_mime_hdrs off

#  TAG: useragent_log
#	If configured with the "--enable-useragent_log" configure
#	option, Squid will write the User-Agent field from HTTP
#	requests to the filename specified here.  By default
#	useragent_log is disabled.
#
#useragent_log none

#  TAG: pid_filename
#	A filename to write the process-id to.  To disable, enter "none".
#
pid_filename /var/run/squid.pid

#  TAG: debug_options
#	Logging options are set as section,level where each source file
#	is assigned a unique section.  Lower levels result in less
#	output,  Full debugging (level 9) can result in a very large
#	log file, so be careful.  The magic word "ALL" sets debugging
#	levels for all sections.  We recommend normally running with
#	"ALL,1".
#
debug_options ALL,1

#  TAG: log_fqdn	on|off
#	Turn this on if you wish to log fully qualified domain names
#	in the access.log. To do this Squid does a DNS lookup of all
#	IP's connecting to it. This can (in some situations) increase
#	latency, which makes your cache seem slower for interactive
#	browsing. 
#
#log_fqdn off

#  TAG: client_netmask
#	A netmask for client addresses in logfiles and cachemgr output.
#	Change this to protect the privacy of your cache clients.
#	A netmask of 255.255.255.0 will log all IP's in that range with
#	the last digit set to '0'.
#
client_netmask 255.255.255.255


# OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
# -----------------------------------------------------------------------------

#  TAG: ftp_user
#	If you want the anonymous login password to be more informative
#	(and enable the use of picky ftp servers), set this to something
#	resonable for your domain, like wwwuser@somewhere.net
#
#	The reason why this is domainless by default is that the
#	request can be made on the behalf of a user in any domain,
#	depending on how the cache is used.
#	Some ftp server also validate that the email address is valid
#	(for example perl.com).
#
ftp_user Squid@

#  TAG: ftp_list_width
#	Sets the width of ftp listings. This should be set to fit in
#	the width of a standard browser. Setting this too small
#	can cut off long filenames when browsing ftp sites.
#
ftp_list_width 50

#  TAG: cache_dns_program
#	Specify the location of the executable for dnslookup process.
#
#NOT IN 2.3#cache_dns_program /usr/lib/squid/dnsserver

#  TAG: dns_children
#	The number of processes spawn to service DNS name lookups.
#	For heavily loaded caches on large servers, you should
#	probably increase this value to at least 10.  The maximum
#	is 32.  The default is 5.
#
#NOT IN 2.3#dns_children 5

#  TAG: dns_defnames	on|off
#	Normally the 'dnsserver' disables the RES_DEFNAMES resolver
#	option (see res_init(3)).  This prevents caches in a hierarchy
#	from interpreting single-component hostnames locally.  To allow
#	dnsserver to handle single-component names, enable this
#	option.
#
#dns_defnames off

#  TAG: dns_nameservers
#	Use this if you want to specify a list of DNS name servers
#	(IP addresses) to use instead of those given in your
#	/etc/resolv.conf file.
#
#	Example: dns_nameservers 10.0.0.1 192.172.0.4
#
#dns_nameservers none

#  TAG: unlinkd_program
#	Specify the location of the executable for file deletion process.
#	This isn't needed if you are using async-io since it's handled by
#	a thread.
#
unlinkd_program /usr/lib/squid/unlinkd

#  TAG: pinger_program
#	Specify the location of the executable for the pinger process.
#	This is only useful if you configured Squid (during compliation)
#	with the '--enable-icmp' option.
#
###pinger_program /usr/lib/squid/pinger

#  TAG: redirect_program
#	Specify the location of the executable for the URL redirector.
#	Since they can perform almost any function there isn't one included.
#	See the Release-Notes for information on how to write one.
#	By default, a redirector is not used.
#
#redirect_program none

#  TAG: redirect_children
#	The number of redirector processes to spawn. If you start
#	too few Squid will have to wait for them to process a backlog of
#	URLs, slowing it down. If you start too many they will use RAM
#	and other system resources.
#
#redirect_children 5

#  TAG: redirect_rewrites_host_header
#	By default Squid rewrites any Host: header in redirected requests.
#	If you are running a accelerator then this may not be a wanted effect
#	of a redirector.
#redirect_rewrites_host_header on

#  TAG: authenticate_program
#	Specify the command for the external authenticator.  Such a
#	program reads a line containing "username password" and replies
#	"OK" or "ERR" in an endless loop.  If you use an authenticator,
#	make sure you have 1 acl of type proxy_auth.  By default, the
#	authenticator_program is not used.
#
#	If you want to use the traditional proxy authentication,
#	jump over to the ../auth_modules/NCSA directory and
#	type:
#		% make
#		% make install
#
#	Then, set this line to something like
#
authenticate_program /usr/lib/squid/ncsa_auth /etc/squid_pwd
#
#authenticate_program none

#  TAG: authenticate_children
#	The number of authenticator processes to spawn (default 5). If you
#	start too few Squid will have to wait for them to process a backlog
#	of usercode/password verifications, slowing it down. When password
#	verifications are done via a (slow) network you are likely to need
#	lots of authenticator processes.
#
#authenticate_children 5

#  TAG: authenticate_ttl
#	The time a checked username/password combination remains cached
#	(default 3600). If a wrong password is given for a cached user,
#	the user gets removed from the username/password cache forcing
#	a revalidation.
#
#authenticate_ttl 3600


# OPTIONS FOR TUNING THE CACHE
# -----------------------------------------------------------------------------

#  TAG: wais_relay_host
#  TAG: wais_relay_port
#	Relay WAIS request to host (1st arg) at port (2 arg).
#
#wais_relay_host localhost
#wais_relay_port 8000

#  TAG: request_size	(KB)
#	Maximum allowed request size in kilobytes.  If people are using
#	POST to upload files, then set this to the largest acceptable
#	filesize plus a few extra kbytes.
#
#request_size 4096 KB

#  TAG: refresh_pattern
#	usage: refresh_pattern [-i] regex min percent max [options]
#
#	By default, regular expressions are CASE-SENSITIVE.  To make
#	them case-insensitive, use the -i option.
#
#	min and max are specified in MINUTES.
#	percent is an integer number.
#
#	options: override-expire
#		 override-lastmod
#		 reload-into-ims
#		 ignore-reload
#
#		override-expire enforces min age even if the server
#		sent a Expires: header. Doing this VIOLATES the HTTP
#		standard.  Enabling this feature could make you liable
#		for problems which it causes.
#
#		override-lastmod enforces min age even on objects
#		that was modified recently.
#
#		reload-into-ims changes client no-cache or ``reload''
#		to If-Modified-Since requests. Doing this VIOLATES the
#		HTTP standard. Enabling this feature could make you
#		liable for problems which it causes.
#
#		ignore-reload ignores a client no-cache or ``reload''
#		header. Doing this VIOLATES the HTTP standard. Enabling
#		this feature could make you liable for problems which
#		it causes.
#		
#	Please see the file doc/Release-Notes-1.1.txt for a full
#	description of Squid's refresh algorithm.  Basically a
#	cached object is: (the order is changed from 1.1.X)
#
#		FRESH if expires < now, else STALE
#		STALE if age > max
#		FRESH if lm-factor < percent, else STALE
#		FRESH if age < min
#		else STALE
#
#	The refresh_pattern lines are checked in the order listed here.
#	The first entry which matches is used.  If none of the entries
#	match, then the default will be used.
#
#Default:
#refresh_pattern		^ftp:		1440	20%	10080
#refresh_pattern		^gopher:	1440	0%	1440
#refresh_pattern 	.		0	20%	4320

#  TAG: reference_age
#	As a part of normal operation, Squid performs Least Recently
#	Used removal of cached objects.  The LRU age for removal is
#	computed dynamically, based on the amount of disk space in
#	use.  The dynamic value can be seen in the Cache Manager 'info'
#	output.
#
#	The 'reference_age' parameter defines the maximum LRU age.  For
#	example, setting reference_age to '1 week' will cause objects
#	to be removed if they have not been accessed for a week or
#	more.  The default value is one month.
#
#	Specify a number here, followed by units of time.  For example:
#		1 week
#		3.5 days
#		4 months
#		2.2 hours
#
reference_age 2 weeks

#  TAG: quick_abort_min	(KB)
#  TAG: quick_abort_max	(KB)
#  TAG: quick_abort_pct	(percent)
#	The cache can be configured to continue downloading aborted
#	requests.  This may be undesirable on slow (e.g. SLIP) links
#	and/or very busy caches.  Impatient users may tie up file
#	descriptors and bandwidth by repeatedly requesting and
#	immediately aborting downloads.
#
#	When the user aborts a request, Squid will check the
#	quick_abort values to the amount of data transfered until
#	then.
#
#	If the transfer has less than 'quick_abort_min' KB remaining,
#	it will finish the retrieval.  Setting 'quick_abort_min' to -1
#	will disable the quick_abort feature.
#
#	If the transfer has more than 'quick_abort_max' KB remaining,
#	it will abort the retrieval.
#
#	If more than 'quick_abort_pct' of the transfer has completed,
#	it will finish the retrieval.
#
#quick_abort_min 16 KB
#quick_abort_max 16 KB
quick_abort_pct 75

#  TAG: negative_ttl	time-units
#	Time-to-Live (TTL) for failed requests.  Certain types of
#	failures (such as "connection refused" and "404 Not Found") are
#	negatively-cached for a configurable amount of time.  The
#	default is 5 minutes.  Note that this is different from
#	negative caching of DNS lookups.
#
negative_ttl 5 minutes

#  TAG: positive_dns_ttl	time-units
#	Time-to-Live (TTL) for positive caching of successful DNS lookups.
#	Default is 6 hours (360 minutes).  If you want to minimize the
#	use of Squid's ipcache, set this to 1, not 0.
#
positive_dns_ttl 6 hours

#  TAG: negative_dns_ttl	time-units
#	Time-to-Live (TTL) for negative caching of failed DNS lookups.
#
negative_dns_ttl 5 minutes

#  TAG: range_offset_limit	(bytes)
#	Sets a upper limit on how far into the the file a Range request
#	may be to cause Squid to prefetch the whole file. If beyond this
#	limit then Squid forwards the Range request as it is and the result
#	is NOT cached.
#
#	This is to stop a far ahead range request (lets say start at 17MB)
#	from making Squid fetch the whole object up to that point before
#	sending anything to the client.
#
#	A value of -1 causes Squid to always fetch the object from the
#	beginning so that it may cache the result. (2.0 style)
#
#	A value of 0 causes Squid to never fetch more than the client
#	client requested. (default)
#
#range_offset_limit 0 KB


# TIMEOUTS
# -----------------------------------------------------------------------------

#  TAG: connect_timeout	time-units
#	Some systems (notably Linux) can not be relied upon to properly
#	time out connect(2) requests.  Therefore the Squid process
#	enforces its own timeout on server connections.  This parameter
#	specifies how long to wait for the connect to complete.  The
#	default is two minutes (120 seconds).
#
connect_timeout 120 seconds

#  TAG: siteselect_timeout	time-units
#	For URN to multiple URL's URL selection
#
#siteselect_timeout 4 seconds

#  TAG: read_timeout	time-units
#	The read_timeout is applied on server-side connections.  After
#	each successful read(), the timeout will be extended by this
#	amount.  If no data is read again after this amount of time,
#	the request is aborted and logged with ERR_READ_TIMEOUT.  The
#	default is 15 minutes.
#
#read_timeout 15 minutes

#  TAG: request_timeout
#	How long to wait for an HTTP request after connection
#	establishment.  For persistent connections, wait this long
#	after the previous request completes.
#
request_timeout 30 seconds

#  TAG: client_lifetime	time-units
#	The maximum amount of time that a client (browser) is allowed to
#	remain connected to the cache process.  This protects the Cache
#	from having alot of sockets (and hence file descriptors) tied up
#	in a CLOSE_WAIT state from remote clients that go away without
#	properly shutting down (either because of a network failure or
#	because of a poor client implementation).  The default is one
#	day, 1440 minutes.
#
#	NOTE:  The default value is intended to be much larger than any
#	client would ever need to be connected to your cache.  You
#	should probably change client_lifetime only as a last resort.
#	If you seem to have many client connections tying up
#	filedescriptors, we recommend first tuning the read_timeout,
#	request_timeout, pconn_timeout and quick_abort values.
#
client_lifetime 1 day

#  TAG: half_closed_clients
#	Some clients may shutdown the sending side of their TCP
#	connections, while leaving their receiving sides open.	Sometimes,
#	Squid can not tell the difference between a half-closed and a
#	fully-closed TCP connection.  By default, half-closed client
#	connections are kept open until a read(2) or write(2) on the
#	socket returns an error.  Change this option to 'off' and Squid
#	will immediately close client connections when read(2) returns
#	"no more data to read."
#
half_closed_clients on

#  TAG: pconn_timeout
#	Timeout for idle persistent connections to servers and other
#	proxies.
pconn_timeout 120 seconds

#  TAG: ident_timeout
#	Maximum time to wait for IDENT requests.  If this is too high,
#	and you enabled 'ident_lookup', then you might be susceptible
#	to denial-of-service by having many ident requests going at
#	once.
#
#	This option may be disabled by using --disable-ident with
#	the configure script.
ident_timeout 10 seconds

#  TAG: shutdown_lifetime	time-units
#	When SIGTERM or SIGHUP is received, the cache is put into
#	"shutdown pending" mode until all active sockets are closed.
#	This value is the lifetime to set for all open descriptors
#	during shutdown mode.  Any active clients after this many
#	seconds will receive a 'timeout' message.
#
shutdown_lifetime 30 seconds


# ACCESS CONTROLS
# -----------------------------------------------------------------------------

#  TAG: acl
#	Defining an Access List
#
#	acl aclname acltype string1 ...
#	acl aclname acltype "file" ...
#
#	when using "file", the file should contain one item per line
#
#	acltype is one of src dst srcdomain dstdomain url_pattern
#		urlpath_pattern time port proto method browser user
#
#	By default, regular expressions are CASE-SENSITIVE.  To make
#	them case-insensitive, use the -i option.
#
#	acl aclname src      ip-address/netmask ... (clients IP address)
#	acl aclname src      addr1-addr2/netmask ... (range of addresses)
#	acl aclname dst      ip-address/netmask ... (URL host's IP address)
#	acl aclname myip     ip-address/netmask ... (local socket IP address)
#
#	acl aclname srcdomain   foo.com ...     # reverse lookup, client IP
#	acl aclname dstdomain   foo.com ...     # Destination server from URL
#	acl aclname srcdom_regex [-i] xxx ...   # regex matching client name
#	acl aclname dstdom_regex [-i] xxx ...   # regex matching server
#	  # For dstdomain and dstdom_regex  a reverse lookup is tried if a IP
#	  # based URL is used. The name "none" is used if the reverse lookup
#	  # fails.
#
#	acl aclname time     [day-abbrevs]  [h1:m1-h2:m2]
#	    day-abbrevs:
#		S - Sunday
#		M - Monday
#		T - Tuesday
#		W - Wednesday
#		H - Thursday
#		F - Friday
#		A - Saturday
#	    h1:m1 must be less than h2:m2
#	acl aclname url_regex [-i] ^http:// ...	# regex matching on whole URL
#	acl aclname urlpath_regex [-i] \.gif$ ...	# regex matching on URL path
#	acl aclname port     80 70 21 ...
#	acl aclname port     0-1024 ...		# ranges allowed
#	acl aclname proto    HTTP FTP ...
#	acl aclname method   GET POST ...
#	acl aclname browser  [-i] regexp
#	  # pattern match on User-Agent header
#	acl aclname ident    username ...
#	  # string match on ident output.
#	  # use REQUIRED to accept any non-null ident.
#	acl aclname src_as   number ... 
#	acl aclname dst_as   number ...
#	  # Except for access control, AS numbers can be used for
#	  # routing of requests to specific caches. Here's an 
#	  # example for routing all requests for AS#1241 and only 
#	  # those to mycache.mydomain.net:
#	  # acl asexample dst_as 1241
#	  # cache_peer_access mycache.mydomain.net allow asexample
#	  # cache_peer_access mycache_mydomain.net deny all
#
#	acl aclname proxy_auth username ...
#	  # list of valid usernames
#	  # use REQUIRED to accept any valid username.
#	  #
#	  # NOTE: when a Proxy-Authentication header is sent but it is not
#	  # needed during ACL checking the username is NOT logged
#	  # in access.log.
#	  #
#	  # NOTE: proxy_auth requires a EXTERNAL authentication program
#	  # to check username/password combinations (see
#	  # authenticate_program).
#	  #
#	  # WARNING: proxy_auth can't be used in a transparent proxy. It
#	  # collides with any authentication done by origin servers. It may
#	  # seem like it works at first, but it doesn't.
#
#	acl aclname snmp_community string ...
#	  # A community string to limit access to your SNMP Agent
#	  # Example:
#	  # 
#	  #	acl snmppublic snmp_community public
#
#
#Examples:
#acl myexample dst_as 1241
# VIX
acl password proxy_auth REQUIRED
#
#Defaults:
acl all src 0.0.0.0/0.0.0.0
acl manager proto cache_object
acl localhost src 127.0.0.1/255.255.255.255
acl localnet src 10.0.0.0/255.255.255.0
#acl localnet src 192.168.1.0/255.255.255.0
acl SSL_ports port 443 563
acl Safe_ports port 80 21 443 563 70 210 1025-65535
acl purge method PURGE
acl CONNECT method CONNECT

# added by VIX
# DENY destinations:
acl CHATS dstdomain www.pokec.sk pokec.azet.sk www.onlinehry.sk www.doodie.com www.pokemon.sk www.atlantis.sk www.oddych.sk 
acl CHATS_REGEXP url_regex -i chat\.

acl MILIONAR dst 212.71.156.26/255.255.255.255

# DENY work days:
acl day1 time M 8:00-14:30
acl day2 time T 8:00-14:30
acl day3 time W 8:00-13:45
acl day4 time H 8:00-15:20
acl day5 time F 8:00-14:30

# DENY workstations:
acl labs src 10.0.0.10-10.0.0.49/255.255.255.255
acl admin ident admin vix karol stilgar pccd
# end VIX

#  TAG: http_access
#	Allowing or Denying access based on defined access lists
#
#	Access to the HTTP port:
#	http_access allow|deny [!]aclname ...
#
#	Access to the ICP port:
#	icp_access  allow|deny [!]aclname ...
#
#	NOTE on default values:
#
#	If there are no "access" lines present, the default is to allow
#	the request.
#
#	If none of the "access" lines cause a match, the default is the
#	opposite of the last line in the list.  If the last line was
#	deny, then the default is allow.  Conversely, if the last line
#	is allow, the default will be deny.  For these reasons, it is a
#	good idea to have an "deny all" or "allow all" entry at the end
#	of your access lists to avoid potential confusion.
#
#Default configuration:
# VIX
###http_access allow password

http_access allow manager localhost
http_access deny manager
http_access allow purge localhost
http_access deny purge
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports

# added by VIX
# XXX: doesn't work with 1 day rule!!!
http_access deny CHATS labs day1
http_access deny CHATS labs day2
http_access deny CHATS labs day3
http_access deny CHATS labs day4
http_access deny CHATS labs day5
# end of VIX
# added by VIX
# XXX: doesn't work with 1 day rule!!!
http_access deny CHATS_REGEXP labs day1
http_access deny CHATS_REGEXP labs day2
http_access deny CHATS_REGEXP labs day3
http_access deny CHATS_REGEXP labs day4
http_access deny CHATS_REGEXP labs day5
# end of VIX
# added by VIX
# XXX: doesn't work with 1 day rule!!!
http_access deny MILIONAR labs day1
http_access deny MILIONAR labs day2
http_access deny MILIONAR labs day3
http_access deny MILIONAR labs day4
http_access deny MILIONAR labs day5
# end of VIX

#
# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
#
http_access allow localnet
http_access allow localhost
http_access deny all

#  TAG: icp_access
#	Reply to all ICP queries we receive
#
icp_access allow all

#  TAG: miss_access
#	Use to force your neighbors to use you as a sibling instead of
#	a parent.  For example:
#
#		acl localclients src 172.16.0.0/16
#		miss_access allow localclients
#		miss_access deny  !localclients
#
#	This means that only your local clients are allowed to fetch
#	MISSES and all other clients can only fetch HITS.
#
#	By default, allow all clients who passed the http_access rules
#	to fetch MISSES from us.
miss_access allow all

#  TAG: cache_peer_access
#	Similar to 'cache_peer_domain' but provides more flexibility by
#	using ACL elements.
#
#	cache_peer_access cache-host allow|deny [!]aclname ...
#
#	The syntax is identical to 'http_access' and the other lists of
#	ACL elements.  See the comments for 'http_access' below, or
#	the Squid FAQ (http://squid.nlanr.net/Squid/FAQ/FAQ-10.html).

#  TAG: proxy_auth_realm
#	Specifies the realm name which is to be reported to the client for
#	proxy authentication (part of the text the user will see when
#	prompted their username and password).
#
#proxy_auth_realm Squid proxy-caching web server

#  TAG: ident_lookup_access
#	A list of ACL elements which, if matched, cause an ident
#	(RFC 931) lookup to be performed for this request.  For
#	example, you might choose to always perform ident lookups
#	for your main multi-user Unix boxes, but not for your Macs
#	and PCs.  By default, ident lookups are not performed for
#	any requests.
#
#	To enable ident lookups for specific client addresses, you
#	can follow this example:
# 
#	acl ident_aware_hosts src 198.168.1.0/255.255.255.0
#	ident_lookup_access allow ident_aware_hosts
#	ident_lookup_access deny all
#
#	This option may be disabled by using --disable-ident with
#	the configure script.
#ident_lookup_access deny all


# ADMINISTRATIVE PARAMETERS
# -----------------------------------------------------------------------------

#  TAG: cache_mgr
#	Email-address of local cache manager who will receive
#	mail if the cache dies.  The default is "webmaster."
#
cache_mgr admin

#  TAG: cache_effective_user
#  TAG: cache_effective_group
#
#	If the cache is run as root, it will change its effective/real
#	UID/GID to the UID/GID specified below.  The default is to
#	change to UID to nobody and GID to nogroup.
#
#	If Squid is not started as root, the default is to keep the
#	current UID/GID.  Note that if Squid is not started as root then
#	you cannot set http_port to a value lower than 1024.
#
cache_effective_user proxy
cache_effective_group proxy

#  TAG: visible_hostname
#	If you want to present a special hostname in error messages, etc,
#	then define this.  Otherwise, the return value of gethostname()
#	will be used. If you have multiple caches in a cluster and
#	get errors about IP-forwarding you must set them to have individual
#	names with this setting.
#
#visible_hostname www-cache.foo.org

#  TAG: unique_hostname
#	If you want to have multiple machines with the same
#	'visible_hostname' then you must give each machine a different
#	'unique_hostname' so that forwarding loops can be detected.
#
#unique_hostname www-cache1.foo.org


# OPTIONS FOR THE CACHE REGISTRATION SERVICE
# -----------------------------------------------------------------------------
#
#	This section contains parameters for the (optional) cache
#	announcement service.  This service is provided to help
#	cache administrators locate one another in order to join or
#	create cache hierarchies.
#
#	An 'announcement' message is sent (via UDP) to the registration
#	service by Squid.  By default, the annoucement message is NOT
#	SENT unless you enable it with 'announce_period' below.
#
#	The announcement message includes your hostname, plus the
#	following information from this configuration file:
#
#		http_port
#		icp_port
#		cache_mgr
#
#	All current information is processed regularly and made
#	available on the Web at http://ircache.nlanr.net/Cache/Tracker/.

#  TAG: announce_period
#	This is how frequently to send cache announcements.  The
#	default is `0' which disables sending the announcement
#	messages.
#
#	To enable announcing your cache, just uncomment the line
#	below.
#
#announce_period 1 day

#  TAG: announce_host
#  TAG: announce_file
#  TAG: announce_port
#	announce_host and announce_port set the hostname and port
#	number where the registration message will be sent.
#
#	Hostname will default to 'tracker.ircache.net' and port will
#	default default to 3131.  If the 'filename' argument is given,
#	the contents of that file will be included in the announce
#	message.
#
#announce_host tracker.ircache.net
#announce_port 3131


# HTTPD-ACCELERATOR OPTIONS
# -----------------------------------------------------------------------------

#  TAG: httpd_accel_host
#  TAG: httpd_accel_port
#	If you want to run Squid as an httpd accelerator, define the
#	host name and port number where the real HTTP server is.
#
#	If you want virtual host support then specify the hostname
#	as "virtual".
#
#	NOTE: enabling httpd_accel_host disables proxy-caching and
#	ICP.  If you want these features enabled also, then set
#	the 'httpd_accel_with_proxy' option.
#
#httpd_accel_host hostname
#httpd_accel_port port

#  TAG: httpd_accel_with_proxy	on|off
#	If you want to use Squid as both a local httpd accelerator
#	and as a proxy, change this to 'on'.
#
#httpd_accel_with_proxy off

#  TAG: httpd_accel_uses_host_header	on|off
#	HTTP/1.1 requests include a Host: header which is basically the
#	hostname from the URL.  Squid can be an accelerator for
#	different HTTP servers by looking at this header.  However,
#	Squid does NOT check the value of the Host header, so it opens
#	a big security hole.  We recommend that this option remain
#	disabled unless you are sure of what you are doing.
#
#	However, you will need to enable this option if you run Squid
#	as a transparent proxy.  Otherwise, virtual servers which
#	require the Host: header will not be properly cached.
#httpd_accel_uses_host_header off


# MISCELLANEOUS
# -----------------------------------------------------------------------------

#  TAG: dns_testnames
#	The DNS tests exit as soon as the first site is successfully looked up
#
#	If you want to disable DNS tests, do not comment out or delete this
#	list.  Instead use the -D command line option
#
dns_testnames www.infovek.sk www.sanet.sk www.debian.org

#  TAG: logfile_rotate
#	Specifies the number of logfile rotations to make when you
#	type 'squid -k rotate'.  The default is 10, which will rotate
#	with extensions 0 through 9.  Setting logfile_rotate to 0 will
#	disable the rotation, but the logfiles are still closed and
#	re-opened.  This will enable you to rename the logfiles
#	yourself just before sending the rotate signal.
#
#	Note, the 'squid -k rotate' command normally sends a USR1
#	signal to the running squid process.  In certain situations
#	(e.g. on Linux with Async I/O), USR1 is used for other
#	purposes, so -k rotate uses another signal.  It is best to get
#	in the habit of using 'squid -k rotate' instead of 'kill -USR1
#	<pid>'.
#
logfile_rotate 0

#  TAG: append_domain
#	Appends local domain name to hostnames without any dots in
#	them.  append_domain must begin with a period.
#
append_domain .vazka.sk

#  TAG: tcp_recv_bufsize	(bytes)
#	Size of receive buffer to set for TCP sockets.  Probably just
#	as easy to change your kernel's default.  Set to zero to use
#	the default buffer size.
#
#tcp_recv_bufsize 0 bytes

#  TAG: err_html_text
#	HTML text to include in error messages.  Make this a "mailto"
#	URL to your admin address, or maybe just a link to your
#	organizations Web page.
#
#	To include this in your error messages, you must rewrite
#	the error template files (found in the "errors" directory).
#	Wherever you want the 'err_html_text' line to appear,
#	insert a %L tag in the error template file.
#err_html_text

#  TAG: deny_info
#	Usage:   deny_info err_page_name acl
#	Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
#
#	This can be used to return a ERR_ page for requests which
#	do not pass the 'http_access' rules.  A single ACL will cause
#	the http_access check to fail.  If a 'deny_info' line exists
#	for that ACL then Squid returns a corresponding error page.
#
#	You may use ERR_ pages that come with Squid or create your own pages
#	and put them into the configured errors/ directory.

#  TAG: memory_pools	on|off
#	If set, Squid will keep pools of allocated (but unused) memory
#	available for future use.  If memory is a premium on your
#	system and you believe your malloc library outperforms Squid 
#	routines, disable this.
#
#memory_pools on

#  TAG: memory_pools_limit	(bytes)
#	Used only with memory_pools on:
#	memory_pools_limit 50 MB
#
#	If set to a non-zero value, Squid will keep at most the specified
#	limit of allocated (but unused) memory in memory pools. All free()
#	requests that exceed this limit will be handled by your malloc
#	library. Squid does not pre-allocate any memory, just safe-keeps
#	objects that otherwise would be free()d. Thus, it is safe to set
#	memory_pools_limit to a reasonably high value even if your
#	configuration will use less memory.
#
#	If not set (default) or set to zero, Squid will keep all memory it
#	can. That is, there will be no limit on the total amount of memory
#	used for safe-keeping.
#
#	To disable memory allocation optimization, do not set
#	memory_pools_limit to 0. Set memory_pools to "off" instead.
#
#	An overhead for maintaining memory pools is not taken into account
#	when the limit is checked. This overhead is close to four bytes per
#	object kept. However, pools may actually _save_ memory because of
#	reduced memory thrashing in your malloc library.

#  TAG: forwarded_for	on|off
#	If set, Squid will include your system's IP address or name
#	in the HTTP requests it forwards.  By default it looks like
#	this:
#
#		X-Forwarded-For: 192.1.2.3
#
#	If you disable this, it will appear as
#
#		X-Forwarded-For: unknown
#
#forwarded_for on

#  TAG: log_icp_queries	on|off
#	If set, ICP queries are logged to access.log. You may wish
#	do disable this if your ICP load is VERY high to speed things
#	up or to simplify log analysis.
#
#log_icp_queries on

#  TAG: icp_hit_stale	on|off
#	If you want to return ICP_HIT for stale cache objects, set this
#	option to 'on'.  If you have sibling relationships with caches
#	in other administrative domains, this should be 'off'.  If you only
#	have sibling relationships with caches under your control, then
#	it is probably okay to set this to 'on'.
#
#icp_hit_stale off

#  TAG: minimum_direct_hops
#	If using the ICMP pinging stuff, do direct fetches for sites
#	which are no more than this many hops away.
#
#minimum_direct_hops 4

#  TAG: cachemgr_passwd
#	Specify passwords for cachemgr operations.
#
#	Usage: cachemgr_passwd password action action ...
#
#	Some valid actions are (see cache manager menu for a full list):
#		5min
#		60min
#		asndb
#		authenticator
#		cbdata
#		client_list
#		comm_incoming
#		config *
#		counters
#		delay
#		digest_stats
#		dns
#		events
#		filedescriptors
#		fqdncache
#		histograms
#		http_headers
#		info
#		io
#		ipcache
#		mem
#		menu
#		netdb
#		non_peers
#		objects
#		pconn
#		peer_select
#		redirector
#		refresh
#		server_list
#		shutdown *
#		store_digest
#		storedir
#		utilization
#		via_headers
#		vm_objects
#
#	* Indicates actions which will not be performed without a
#	  valid password, others can be performed if not listed here.
#
#	To disable an action, set the password to "disable".
#	To allow performing an action without a password, set the
#	password to "none".
#
#	Use the keyword "all" to set the same password for all actions.
#
#cachemgr_passwd secret shutdown
#cachemgr_passwd lesssssssecret info stats/objects
#cachemgr_passwd disable all

#  TAG: store_avg_object_size	(kbytes)
#	Average object size, used to estimate number of objects your
#	cache can hold.  See doc/Release-Notes-1.1.txt.  The default is
#	13 KB.
#
#store_avg_object_size 13 KB

#  TAG: store_objects_per_bucket
#	Target number of objects per bucket in the store hash table.
#	Lowering this value increases the total number of buckets and
#	also the storage maintenance rate.  The default is 20.
#
#store_objects_per_bucket 50

#  TAG: client_db	on|off
#	If you want to disable collecting per-client statistics, then
#	turn off client_db here.
#
#client_db on

#  TAG: netdb_low
#  TAG: netdb_high
#	The low and high water marks for the ICMP measurement
#	database.  These are counts, not percents.  The defaults are
#	900 and 1000.  When the high water mark is reached, database
#	entries will be deleted until the low mark is reached.
#
#netdb_low 900
#netdb_high 1000

#  TAG: netdb_ping_period
#	The minimum period for measuring a site.  There will be at
#	least this much delay between successive pings to the same
#	network.  The default is five minutes.
#
#netdb_ping_period 5 minutes

#  TAG: query_icmp	on|off
#	If you want to ask your peers to include ICMP data in their ICP
#	replies, enable this option.
#
#	If your peer has configured Squid (during compilation) with
#	'--enable-icmp' then that peer will send ICMP pings to origin server
#	sites of the URLs it receives.  If you enable this option then the
#	ICP replies from that peer will include the ICMP data (if available).
#	Then, when choosing a parent cache, Squid will choose the parent with
#	the minimal RTT to the origin server.  When this happens, the
#	hierarchy field of the access.log will be
#	"CLOSEST_PARENT_MISS".  This option is off by default.
#
#query_icmp off

#  TAG: test_reachability	on|off
#	When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
#	instead of ICP_MISS if the target host is NOT in the ICMP
#	database, or has a zero RTT.
#
#test_reachability off

#  TAG: buffered_logs	on|off
#	Some log files (cache.log, useragent.log) are written with
#	stdio functions, and as such they can be buffered or
#	unbuffered.  By default they will be unbuffered. Buffering them
#	can speed up the writing slightly (though you are unlikely to
#	need to worry).
#buffered_logs off

#  TAG: reload_into_ims	on|off
#	When you enable this option, client no-cache or ``reload''
#	requests will be changed to If-Modified-Since requests.
#	Doing this VIOLATES the HTTP standard.  Enabling this
#	feature could make you liable for problems which it
#	causes.
#	
#	see also refresh_pattern for a more selective approach.
#
#	This option may be disabled by using --disable-http-violations
#	with the configure script.
#reload_into_ims off

#  TAG: always_direct
#	Usage: always_direct allow|deny [!]aclname ...
#
#	Here you can use ACL elements to specify requests which should
#	ALWAYS be forwarded directly to origin servers.  For example,
#	to always directly forward requests for local servers use
#	something like:
#
#		acl local-servers dstdomain my.domain.net
#		always_direct allow local-servers
#
#	To always forward FTP requests directly, use
#
#		acl FTP proto FTP
#		always_direct allow FTP
#
#	NOTE: There is a similar, but opposite option named
#	'never_direct'.  You need to be aware that "always_direct deny
#	foo" is NOT the same thing as "never_direct allow foo".  You
#	may need to use a deny rule to exclude a more-specific case of
#	some other rule.  Example:
#
#		acl local-external dstdomain external.foo.net
#		acl local-servers dstdomain  foo.net
#		always_direct deny local-external
#		always_direct allow local-servers
#
#	This option replaces some v1.1 options such as local_domain
#	and local_ip.

#  TAG: never_direct
#	Usage: never_direct allow|deny [!]aclname ...
#
#	never_direct is the opposite of always_direct.  Please read
#	the description for always_direct if you have not already.
#
#	With 'never_direct' you can use ACL elements to specify
#	requests which should NEVER be forwarded directly to origin
#	servers.  For example, to force the use of a proxy for all
#	requests, except those in your local domain use something like:
#
#		acl local-servers dstdomain foo.net
#		acl all src 0.0.0.0/0.0.0.0
#		never_direct deny local-servers
#		never_direct allow all
#	
#	or if squid is inside a firewall and there is local intranet
#	servers inside the firewall then use something like:
#
#		acl local-intranet dstdomain foo.net
#		acl local-external dstdomain external.foo.net
#		always_direct deny local-external
#		always_direct allow local-intranet
#		never_direct allow all
#	
#	This option replaces some v1.1 options such as inside_firewall
#	and firewall_ip.

#  TAG: anonymize_headers
#        Usage: anonymize_headers allow|deny header_name ...
#
#	This option replaces the old 'http_anonymizer' option with
#	something that is much more configurable.  You may now
#	specify exactly which headers are to be allowed, or which
#	are to be removed from outgoing requests.
#
#	There are two methods of using this option.  You may either
#	allow specific headers (thus denying all others), or you
#	may deny specific headers (thus allowing all others).
#
#	For example, to achieve the same behaviour as the old
#	'http_anonymizer standard' option, you should use:
#
#		anonymize_headers deny From Referer Server
#		anonymize_headers deny User-Agent WWW-Authenticate Link
#		
#	Or, to reproduce the old 'http_anonymizer paranoid' feature
#	you should use:
#
#		anonymize_headers allow Allow Authorization Cache-Control
#		anonymize_headers allow Content-Encoding Content-Length
#		anonymize_headers allow Content-Type Date Expires Host
#		anonymize_headers allow If-Modified-Since Last-Modified
#		anonymize_headers allow Location Pragma Accept Charset
#		anonymize_headers allow Accept-Encoding Accept-Language
#		anonymize_headers allow Content-Language Mime-Version
#		anonymize_headers allow Retry-After Title Connection
#		anonymize_headers allow Proxy-Connection
#
#	NOTE: You can not mix "allow" and "deny".  All 'anonymize_headers'
#	lines must have the same second argument.
#
#	By default, all headers are allowed (no anonymizing is
#	performed).
#
#anonymize_headers

#  TAG: fake_user_agent
#	If you filter the User-Agent header with 'anonymize_headers' it
#	may cause some Web servers to refuse your request.  Use this to
#	fake one up.  For example:
#
#	fake_user_agent Nutscrape/1.0 (CP/M; 8-bit)
#	(credit to Paul Southworth pauls@etext.org for this one!)
#
#fake_user_agent none

#  TAG: icon_directory
#	Where the icons are stored. These are normally kept in
#	/usr/lib/squid/icons

#  TAG: error_directory
#	If you wish to create your own versions of the default
#	(English) error files, either to customise them to suit your
#	language or company copy the template english files to another
#	directory and point this tag at them.

# VIX: slovenske chybove hlasky
error_directory /usr/lib/squid/errors/Slovak

#  TAG: minimum_retry_timeout	(seconds)
#	This specifies the minimum connect timeout, for when the
#	connect timeout is reduced to compensate for the availability
#	of multiple IP addresses.
#
#	When a connection to a host is initiated, and that host has
#	several IP addresses, the default connection timeout is reduced
#	by dividing it by the number of addresses.  So, a site with 15
#	addresses would then have a timeout of 8 seconds for each
#	address attempted.  To avoid having the timeout reduced to the
#	point where even a working host would not have a chance to
#	respond, this setting is provided.  The default, and the
#	minimum value, is five seconds, and the maximum value is sixty
#	seconds, or half of connect_timeout, whichever is greater and
#	less than connect_timeout.
#
#minimum_retry_timeout 5 seconds

#  TAG: maximum_single_addr_tries
#	This sets the maximum number of connection attempts for a
#	host that only has one address (for multiple-address hosts,
#	each address is tried once).
#
#	The default value is three tries, the (not recommended)
#	maximum is 255 tries.  A warning message will be generated
#	if it is set to a value greater than ten.
#
#maximum_single_addr_tries 3

#  TAG: snmp_port
#	Squid can now serve statistics and status information via SNMP.
#	By default it listens to port 3401 on the machine. If you don't
#	wish to use SNMP, set this to '-1'.
#
#	NOTE: SNMP support requires use the --enable-snmp configure
#	command line option.
#snmp_port -1

#  TAG: forward_snmpd_port
#	This configures whether we should be forwarding SNMP requests
#	to another snmpd. The reason for putting this piece of
#	functionality into Squid was to enable access to the system's
#	installed snmpd with minimal changes.  This option is turned
#	off by default, check with your /etc/services for your system's
#	snmp port (usually 161).  We do not use getservbyname() to
#	allow you to set Squid into port 161 and your system's snmpd to
#	another port by changing /etc/services.
#
#	WARNING: Because of Squid acting as a proxy snmpd for system
#	you have to do security checks on THIS snmpd for all objects.
#	Check your snmp_config_file.
#forward_snmpd_port 0

#  TAG: snmp_access
#	Allowing or denying access to the SNMP port.
#
#	All access to the agent is denied by default.
#	usage:
#
#	snmp_access allow|deny [!]aclname ...
#
#Example:
#snmp_access allow public localhost
#snmp_access deny all

#  TAG: snmp_incoming_address
#  TAG: snmp_outgoing_address
#	Just like 'udp_incoming_address' above, but for the SNMP port.
#
#	snmp_incoming_address	is used for the SNMP socket receiving
#				messages from SNMP agents.
#	snmp_outgoing_address	is used for SNMP packets returned to SNMP
#				agents.
#
#	The default behaviour is to not bind to any specific address.
#
#	NOTE, snmp_incoming_address and snmp_outgoing_address can not have
#	the same value since they both use port 3130.
#
#snmp_incoming_address 0.0.0.0
#snmp_outgoing_address 0.0.0.0

#  TAG: as_whois_server
#	WHOIS server to query for AS numbers.  NOTE: AS numbers are
#	queried only when Squid starts up, not for every request.


# DELAY POOL PARAMETERS (all require DELAY_POOLS compilation option)
# -----------------------------------------------------------------------------

#  TAG: delay_pools
#	This represents the number of delay pools to be used.  For example,
#	if you have one class 2 delay pool and one class 3 delays pool, you
#	have a total of 2 delay pools.
#
#	To enable this option, you must use --enable-delay-pools with the
#	configure script.
#delay_pools 0

#  TAG: delay_class
#	This defines the class of each delay pool.  There must be exactly one
#	delay_class line for each delay pool.  For example, to define two
#	delay pools, one of class 2 and one of class 3, the settings above
#	and here would be:
#
#delay_pools 2      # 2 delay pools
#delay_class 1 2    # pool 1 is a class 2 pool
#delay_class 2 3    # pool 2 is a class 3 pool
#
#	The delay pool classes are:
#
#		class 1		Everything is limited by a single aggregate
#				bucket.
#
#		class 2 	Everything is limited by a single aggregate
#				bucket as well as an "individual" bucket chosen
#				from bits 25 through 32 of the IP address.
#
#		class 3		Everything is limited by a single aggregate
#				bucket as well as a "network" bucket chosen
#				from bits 17 through 24 of the IP address and a
#				"individual" bucket chosen from bits 17 through
#				32 of the IP address.
#
#	NOTE: If an IP address is a.b.c.d
#		-> bits 25 through 32 are "d"
#		-> bits 17 through 24 are "c"
#		-> bits 17 through 32 are "c * 256 + d"

#  TAG: delay_access
#	This is used to determine which delay pool a request falls into.
#	The first matched delay pool is always used, ie, if a request falls
#	into delay pool number one, no more delay are checked, otherwise the
#	rest are checked in order of their delay pool number until they have
#	all been checked.  For example, if you want some_big_clients in delay
#	pool 1 and lotsa_little_clients in delay pool 2:
#
#delay_access 1 allow some_big_clients
#delay_access 1 deny all
#delay_access 2 allow lotsa_little_clients
#delay_access 2 deny all

#  TAG: delay_parameters
#	This defines the parameters for a delay pool.  Each delay pool has
#	a number of "buckets" associated with it, as explained in the
#	description of delay_class.  For a class 1 delay pool, the syntax is:
#
#delay_parameters pool aggregate
#
#	For a class 2 delay pool:
#
#delay_parameters pool aggregate individual
#
#	For a class 3 delay pool:
#
#delay_parameters pool aggregate network individual
#
#	The variables here are:
#
#		pool		a pool number - ie, a number between 1 and the
#				number specified in delay_pools as used in
#				delay_class lines.
#
#		aggregate	the "delay parameters" for the aggregate bucket
#				(class 1, 2, 3).
#
#		individual	the "delay parameters" for the individual
#				buckets (class 2, 3).
#
#		network		the "delay parameters" for the network buckets
#				(class 3).
#
#	A pair of delay parameters is written restore/maximum, where restore is
#	the number of bytes (not bits - modem and network speeds are usually
#	quoted in bits) per second placed into the bucket, and maximum is the
#	maximum number of bytes which can be in the bucket at any time.
#
#	For example, if delay pool number 1 is a class 2 delay pool as in the
#	above example, and is being used to strictly limit each host to 64kbps
#	(plus overheads), with no overall limit, the line is:
#
#delay_parameters 1 -1/-1 8000/8000
#
#	Note that the figure -1 is used to represent "unlimited".
#
#	And, if delay pool number 2 is a class 3 delay pool as in the above
#	example, and you want to limit it to a total of 256kbps (strict limit)
#	with each 8-bit network permitted 64kbps (strict limit) and each
#	individual host permitted 4800bps with a bucket maximum size of 64kb
#	to permit a decent web page to be downloaded at a decent speed
#	(if the network is not being limited due to overuse) but slow down
#	large downloads more significantly:
#
#delay_parameters 2 32000/32000 8000/8000 600/64000
#
#	There must be one delay_parameters line for each delay pool.

#  TAG: delay_initial_bucket_level	(percent, 0-100)
#	The initial bucket percentage is used to determine how much is put
#	in each bucket when squid starts, is reconfigured, or first notices
#	a host accessing it (in class 2 and class 3, individual hosts and
#	networks only have buckets associated with them once they have been
#	"seen" by squid).
#
#delay_initial_bucket_level 50

#  TAG: incoming_icp_average
#  TAG: incoming_http_average
#  TAG: min_icp_poll_cnt
#  TAG: min_http_poll_cnt
#	Heavy voodoo here.  I can't even believe you are reading this.
#	Are you crazy?  Don't even think about adjusting these unless
#	you understand the algorithms in comm_select.c first!
#
#incoming_icp_average 6
#incoming_http_average 4
#min_icp_poll_cnt 8
#min_http_poll_cnt 8

#  TAG: max_open_disk_fds
#  TAG: offline_mode
#	Enable this option and Squid will never try to validate cached
#	objects.

#  TAG: uri_whitespace
#	What to do with requests that have whitespace characters in the
#	URI.  Options:
#
#	deny:   The request is denied.  The user receives an "Invalid
#		Request" message.
#	allow:  The request is allowed and the URI is not changed.  The
#		whitespace characters remain in the URI.  Note the
#		whitespace is passed to redirector processes if they
#		are in use.
#	encode:	The request is allowed and the whitespace characters are
#		encoded according to RFC1738.  This could be considered
#		a violation of the HTTP/1.1
#		RFC because proxies are not allowed to rewrite URI's.
#	chop:	The request is allowed and the URI is chopped at the
#		first whitespace.  This might also be considered a
#		violation.
#uri_whitespace deny

#  TAG: broken_posts
#	A list of ACL elements which, if matched, causes Squid to send
#	a extra CRLF pair after the body of a PUT/POST request.
#
#	Some HTTP servers has broken implementations of PUT/POST,
#	and rely on a extra CRLF pair sent by some WWW clients.
#
#	Quote from RFC 2068 section 4.1 on this matter:
#
#	  Note: certain buggy HTTP/1.0 client implementations generate an
#	  extra CRLF's after a POST request. To restate what is explicitly
#	  forbidden by the BNF, an HTTP/1.1 client must not preface or follow
#	  a request with an extra CRLF.
#
#acl buggy_server url_regex ^http://....
#broken_posts allow buggy_server

#  TAG: mcast_miss_addr
#	If you enable this option, every "cache miss" URL will
#	be sent out on the specified multicast address.
#
#	Do not enable this option unless you are are absolutely
#	certain you understand what you are doing.

#  TAG: mcast_miss_port
#	This is the port number to be used in conjuction with
#	'mcast_miss_addr'.

#  TAG: mcast_miss_encode_key
#	The URLs that are sent in the multicast miss stream are
#	encrypted.  This is the encryption key.

#  TAG: prefer_direct
#	By default, if the ICP, HTCP, Cache Digest, etc. techniques
#	do not yield a parent cache, Squid gives higher preference
#	to forwarding the request direct to origin servers, rather
#	than selecting a parent cache anyway.
#
#	If you want Squid to give higher precedence to a parent
#	cache, instead of going direct, then turn this option off.
#prefer_direct on

#  TAG: strip_query_terms
#	By default, Squid strips query terms from requested URLs before
#	logging.  This protects your user's privacy.
#strip_query_terms on

#  TAG: coredump_dir
#	By default Squid leaves core files in the first cache_dir
#	directory.  If you set 'coredump_dir' to a directory
#	that exists, Squid will chdir() to that directory at startup
#	and coredump files will be left there.

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© Ivan "VIX" Noris, 2002-2007
mail: vix (zavinac) deja-vix bodka sk