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<H1>Squid 3.4.4 release notes</H1>

<H2>Squid Developers</H2>
<HR>
This document contains the release notes for version 3.4 of Squid.
Squid is a WWW Cache application developed by the National Laboratory
for Applied Network Research and members of the Web Caching community.
<HR>

<H2><A NAME="toc1">1.</A> <A HREF="#s1">Notice</A></H2>

<UL>
<LI><A NAME="toc1.1">1.1</A> <A HREF="#ss1.1">Known issues</A>
<LI><A NAME="toc1.2">1.2</A> <A HREF="#ss1.2">Changes since earlier releases of Squid-3.4</A>
</UL>

<H2><A NAME="toc2">2.</A> <A HREF="#s2">Major new features since Squid-3.3</A></H2>

<UL>
<LI><A NAME="toc2.1">2.1</A> <A HREF="#ss2.1">Helper protocol extensions</A>
<LI><A NAME="toc2.2">2.2</A> <A HREF="#ss2.2">SSL Server Certificate Validator</A>
<LI><A NAME="toc2.3">2.3</A> <A HREF="#ss2.3">Store-ID</A>
<LI><A NAME="toc2.4">2.4</A> <A HREF="#ss2.4">TPROXY Support for OpenBSD 5.1+ and FreeBSD 9+</A>
<LI><A NAME="toc2.5">2.5</A> <A HREF="#ss2.5">Transaction Annotations</A>
<LI><A NAME="toc2.6">2.6</A> <A HREF="#ss2.6">Multicast DNS</A>
</UL>

<H2><A NAME="toc3">3.</A> <A HREF="#s3">Changes to squid.conf since Squid-3.3</A></H2>

<UL>
<LI><A NAME="toc3.1">3.1</A> <A HREF="#ss3.1">New tags</A>
<LI><A NAME="toc3.2">3.2</A> <A HREF="#ss3.2">Changes to existing tags</A>
<LI><A NAME="toc3.3">3.3</A> <A HREF="#ss3.3">Removed tags</A>
</UL>

<H2><A NAME="toc4">4.</A> <A HREF="#s4">Changes to ./configure options since Squid-3.3</A></H2>

<UL>
<LI><A NAME="toc4.1">4.1</A> <A HREF="#ss4.1">New options</A>
<LI><A NAME="toc4.2">4.2</A> <A HREF="#ss4.2">Changes to existing options</A>
<LI><A NAME="toc4.3">4.3</A> <A HREF="#ss4.3">Removed options</A>
</UL>

<H2><A NAME="toc5">5.</A> <A HREF="#s5">Regressions since Squid-2.7</A></H2>

<UL>
<LI><A NAME="toc5.1">5.1</A> <A HREF="#ss5.1">Missing squid.conf options available in Squid-2.7</A>
</UL>

<HR>
<H2><A NAME="s1">1.</A> <A HREF="#toc1">Notice</A></H2>

The Squid Team are pleased to announce the release of Squid-3.4.4 for testing.
This new release is available for download from 
<A HREF="http://www.squid-cache.org/Versions/v3/3.4/">http://www.squid-cache.org/Versions/v3/3.4/</A> or the
<A HREF="http://www.squid-cache.org/Mirrors/http-mirrors.html">mirrors</A>.
While this release is not deemed ready for production use, we believe it is ready for wider testing by the community.
We welcome feedback and bug reports. If you find a bug, please see 
<A HREF="http://wiki.squid-cache.org/SquidFaq/BugReporting">http://wiki.squid-cache.org/SquidFaq/BugReporting</A>
for how to submit a report with a stack trace.

<H2><A NAME="ss1.1">1.1</A> <A HREF="#toc1.1">Known issues</A>
</H2>

Although this release is deemed good enough for use in many setups, please note the existence of 
<A HREF="http://bugs.squid-cache.org/buglist.cgi?query_format=advanced&amp;product=Squid&amp;bug_status=UNCONFIRMED&amp;bug_status=NEW&amp;bug_status=ASSIGNED&amp;bug_status=REOPENED&amp;version=3.4">open bugs against Squid-3.4</A>.

<H2><A NAME="ss1.2">1.2</A> <A HREF="#toc1.2">Changes since earlier releases of Squid-3.4</A>
</H2>

The 3.4 change history can be 
<A HREF="http://www.squid-cache.org/Versions/v3/3.4/changesets/">viewed here</A>.

<H2><A NAME="s2">2.</A> <A HREF="#toc2">Major new features since Squid-3.3</A></H2>

Squid 3.4 represents a new feature release above 3.3.

The most important of these new features are:
<UL>
<LI>Helper protocol extensions</LI>
<LI>SSL Server Certificate Validator</LI>
<LI>Store-ID</LI>
<LI>TPROXY Support for OpenBSD 5.1+ and FreeBSD 9+</LI>
<LI>Transaction Annotations</LI>
<LI>Multicast DNS</LI>
</UL>

Most user-facing changes are reflected in squid.conf (see below).

<H2><A NAME="ss2.1">2.1</A> <A HREF="#toc2.1">Helper protocol extensions</A>
</H2>

Details at 
<A HREF="http://wiki.squid-cache.org/Features/AddonHelpers">http://wiki.squid-cache.org/Features/AddonHelpers</A>.

The Squid helper protocol used to communicate with authenticators,
URL-rewriters, Redirectors, and External ACL helpers has been updated
and extended.

BH status code is now accepted from all helpers to report
internal error events separate from ERR rejection code.
Permitting Squid to perform recovery operations specific to
helper failure instead of a blanket client rejection.

Arbitrary key-value pairs can be returned from any helper.
Allowing future helpers to be forward- and backward- compatible
with this and future versions of Squid.

<H2><A NAME="ss2.2">2.2</A> <A HREF="#toc2.2">SSL Server Certificate Validator</A>
</H2>

Details at 
<A HREF="http://wiki.squid-cache.org/Features/SslServerCertValidator">http://wiki.squid-cache.org/Features/SslServerCertValidator</A>.

The helper consulted after the internal OpenSSL validation, regardless of the
validation results. The helper will receive:

<UL>
<LI>the origin server certificate (chain),</LI>
<LI>the intended domain name, and</LI>
<LI>a list of OpenSSL validation errors (if any).</LI>
</UL>

If the helper decides to honor an OpenSSL error or report another validation 
error(s), the helper will return:

<UL>
<LI>A list of certificates.</LI>
<LI>A list of items consists the the validation error name (see %err_name
error page macro and %err_details code for logformat), error reason
(%ssl_lib_error macro), and the offending certificate.</LI>
</UL>

The returned information mimics what the internal OpenSSL-based validation code
collects now. Returned errors, if any, are fed to sslproxy_cert_error,
triggering the existing SSL error processing code.

The helper invocation controlled by the sslcrtvalidator_program and
sslcrtvalidator_children configurations options which are similar to the
ssl_crtd related options.

<H2><A NAME="ss2.3">2.3</A> <A HREF="#toc2.3">Store-ID</A>
</H2>

Details at 
<A HREF="http://wiki.squid-cache.org/Features/StoreID">http://wiki.squid-cache.org/Features/StoreID</A>.

This feature is a redesigned equivalent to the Squid-2.7 feature known as StoreURL-rewrite.

Notice that this is not a direct portage of the Squid-2.7 feature so behaviour
differences do exist. Although the new feature works in similar enough ways that the old
helper scripts used for Squid-2.7 are expected to work in this and later versions of Squid.

Squid traditionally uses the requested URL as an index key ID to locate objects in cache.
It is not the only key possible and the Store-ID feature exposes an API for external
helpers to provide Squid with an alternative key name for any URL.

When any client request is received which requires a cache lookup the URL is passed to
a helper specified with the store_id_program directive to check for an alternative
Store ID. This allows the helper to identify URLs which refer to duplicate resources and
de-duplicate the cache content. store_id_access is provided to allow ACL-based
tuning of which traffic gets sent to the helper and reduce overheads.

One subtle and noteworthy difference between Squid-2 and Squid-3 which is highlighted by
this feature is that refresh_pattern applies its regex argument against the Store
ID key and not the transaction URL. So using the Store-ID feature to alter the value
affects which refresh_pattern directive will be matched.

Store-ID helpers bundled with Squid can be built with the --enable-storeid-rewrite-helpers
option which is added in this version. Currently there is a file helper
provided.

<H2><A NAME="ss2.4">2.4</A> <A HREF="#toc2.4">TPROXY Support for OpenBSD 5.1+ and FreeBSD 9+</A>
</H2>

Details at 
<A HREF="http://wiki.squid-cache.org/ConfigExamples/Intercept/OpenBsdPf">http://wiki.squid-cache.org/ConfigExamples/Intercept/OpenBsdPf</A>.

The Packet Filter (PF) firewall in OpenBSD 4.4 and later offers traffic interception
using several very simple methods. One of which is the divert-to rule type
which acts as a simple routing diversion instead of performing NAT packet alterations.

The IP Firewall (IPFW) on FreeBSD 9+ contains a port of the Linux Netfilter TPROXY feature.

This version of Squid adds support for these features through the ./configure
options --enable-pf-transparent and --enable-ipfw-transparent when Squid is built on
systems with the required support. No special extras are required to enable
http_port ... tproxy configuration to work.

NOTE: To resolve NAT lookup issues on recent PF firewall versions the code behind
./configure --enable-pf-transparent has been altered and is expected to
break on the version of PF firewall shipped with BSD systems such as NetBSD and FreeBSD
which do not yet support the getsockname() API.
These systems require --with-nat-devpf to enable /dev/pf support when using PF firewall.

<H2><A NAME="ss2.5">2.5</A> <A HREF="#toc2.5">Transaction Annotations</A>
</H2>

Previously the only annotation methods available were ICAP/eCAP HTTP header insertions
or external ACL tag= result code. Each of which had only limited possibilities
for use and little or no correlation.

It is now possible to add annotations to a client transaction from several sources:
<UL>
<LI> Directly from squid.conf using the note directive with
ACL-based selection of which annotation is linked to any
particular transaction.
</LI>
<LI> By configured helper processes returning a key=value pair.
The key name becomes the annotation name.</LI>
</UL>

Annotations on the transaction can be passed to ICAP services or eCAP modules using the
adaptation_meta directive to send them as headers.
They can also be logged using the %note log format code in custom logs. With
the new helper response syntax changes this means all helper response key=value details
such as URL-rewrite or store-id changes, external ACL tag etc. are now able to be logged.

Annotations which are already assigned to a transaction can be checked using an ACL test
of the new note ACL type. This can match a particular note by name and value,
of for any notes with a given name.

NOTE: not all helper interfaces are yet enabled to convert key=value into annotations
and the external ACL interface does not yet send annotations to the helper.

<H2><A NAME="ss2.6">2.6</A> <A HREF="#toc2.6">Multicast DNS</A>
</H2>

The internal DNS component of Squid now supports multicast DNS (mDNS) resolution in
accordance with RFC 6762.

The dns_multicast_local directive must be set to on to enable this
feature.

The multicast DNS group IP addresses for IPv4 and IPv6 resolving are added to the set
of available DNS resolvers and used automatically for domain names ending in .local
and reverse-DNS lookups before attempting a secondary resolution on the configured
resolvers. Domains without .local are resolved using only the configured resolvers.

Statistics for multicast DNS resolution can be found on the idns cache manager
report.

NOTE that the external DNS helper interface is now deprecated and has been
removed from future Squid versions. Any installations still using it for local hostname
resolution need to upgrade to mDNS resolution with this Squid version.

<H2><A NAME="s3">3.</A> <A HREF="#toc3">Changes to squid.conf since Squid-3.3</A></H2>

There have been changes to Squid's configuration file since Squid-3.3.

Squid supports reading configuration option parameters from external
files using the syntax parameters("/path/filename"). For example:
<PRE>
 acl whitelist dstdomain parameters("/etc/squid/whitelist.txt")
</PRE>

There have also been changes to individual directives in the config file.
This section gives a thorough account of those changes in three categories:

<UL>
<LI>
<A HREF="#newtags">New tags</A></LI>
<LI>
<A HREF="#modifiedtags">Changes to existing tags</A></LI>
<LI>
<A HREF="#removedtags">Removed tags</A></LI>
</UL>

<DL>
<DT>configuration_includes_quoted_values<DD>
Whether Squid supports directive parameters with spaces, quotes, and other
special characters. Surround such parameters with "double quotes" and
also set this directive on/off around the relevant squid.conf line(s)
making use of such quoting.

<DT>dns_multicast_local<DD>
Use multicast DNS for .local domains and reverse-DNS resolution.

<DT>note<DD>
Use ACLs to annotate a transaction with customized annotations
which can be logged in access.log

<DT>spoof_client_ip<DD>
Access control to determine whether to disable the TPROXY spoofing on upstream traffic.

<DT>sslcrtvalidator_children<DD>
Specifies the settings for how many SSL server certificate
validator helpers are run and when they are started.

<DT>sslcrtvalidator_program<DD>
Specifies the location of a SSL server certificate validator helper.

<DT>store_id_access<DD>
Whether the URL for a given request is passed to the Store-ID helper process.
Used to improve StoreID performance by quickly eliminating helper delays using ACL tests.
Ported equivalent to storeurl_access from 2.7

<DT>store_id_bypass<DD>
Whether the StoreID helper may be bypassed when overloaded.

<DT>store_id_children<DD>
Controls the number of StoreID helper processes.
Options startup=N, idle=N, concurrency=N
<UL>
<LI>startup=N allow finer tuning of how many helpers are started initially.</LI>
<LI>idle=N allow fine tuning of how many helper to retain as buffer against sudden traffic loads.</LI>
<LI>concurrency=N was previously called url_rewrite_concurrency as a distinct directive.</LI>
</UL>

<DT>store_id_rewrite_program<DD>
A helper program to provide cache storage internal key ID value for a request.
Ported equivalent to storeurl_rewrite_program from 2.7

</DL>

<H2><A NAME="modifiedtags"></A> <A NAME="ss3.2">3.2</A> <A HREF="#toc3.2">Changes to existing tags</A>
</H2>

<DL>
<DT>access_log<DD>
Configuration syntax extended to support name=value options.
New Syntax: access_log module:place [option ...] [acl ...]
New option logformat= to specify the logging format name.
New option buffer-size= to specify how large the log buffer
for this log is to be when buffered_logs is enabled.
New option on-error= to specify what handling is to be done
if the logging module encounters a non-recoverable error writing logs.
With the value die (the default) Squid halts operation.
With the value drop Squid drops log lines and continue running.

<DT>acl<DD>
New test type server_cert_fingerprint to match against 
server SSL certificate fingerprint.
New test type note to match against transaction annotations
by name and value, or just by name.
New test type any-of to match if any one of a set of named ACLs.
New test type all-of to match against all of a set of named ACLs.

<DT>auth_param<DD>
New result code BH to signal helper internal errors
available in all authentication schemes.
New key message= for error message details in all authentication schemes.
New result code OK and key ha1= in Digest authentication.
New result codes OK, ERR replace result codes AF,
and NA in NTLM and Negotiate authentication.
New key token= for NTLM and Negotiate authentication OK responses.
Details at 
<A HREF="http://wiki.squid-cache.org/Features/AddonHelpers">http://wiki.squid-cache.org/Features/AddonHelpers</A>.

<DT>external_acl_type<DD>
Deprecated protocol=3.0 option. No longer necessary.
New result code BH to signal helper internal errors
Details at 
<A HREF="http://wiki.squid-cache.org/Features/AddonHelpers">http://wiki.squid-cache.org/Features/AddonHelpers</A>.

<DT>http_port<DD>
Support IPv6 for intercept mode. Requires ip6tables support on Linux,
PF support on OpenBSD and IPFW support on FreeBSD. Squid will no longer complain
about misconfiguration if IPv6 support is missing, we now rely on the firewall
tools reporting misconfiguration when the NAT rules are created.
Support tproxy mode traffic on BSD systems with BINDANY support
(OpenBSD 5+, FreeBSD 9+ so far).
Changed build options behind intercept traffic mode handling on BSD.
see --enable-pf-transparent for more details.

<DT>logformat<DD>
New format code %note to log a transaction annotation linked to the
transaction by ICAP, eCAP, a helper, or the note squid.conf directive.
New format code %&gt;qos to log client connection TOS/DSCP value set by Squid.
New format code %&lt;qos to log server connection TOS/DSCP value set by Squid.
New format code %&gt;nfmark to log client connection netfilter mark set by Squid.
New format code %&lt;nfmark to log server connection netfilter mark set by Squid.

<DT>pipeline_prefetch<DD>
Updated to take a numeric count of prefetched pipeline requests instead of ON/OFF.

<DT>refresh_pattern<DD>
NOTE: the regular expression pattern operates on the cache Store-ID value.
Which by default is identical to the requested URL, but may differ for some
objects if the Store-ID feature is in use.

<DT>unlinkd_program<DD>
New helper response format utilizing result codes OK and BH,
to signal helper lookup results. Also, key-value response values to return
multiple values to Squid.
Details at 
<A HREF="http://wiki.squid-cache.org/Features/AddonHelpers">http://wiki.squid-cache.org/Features/AddonHelpers</A>.

<DT>url_rewrite_program<DD>
New helper response format utilizing result codes OK, ERR,
and BH to signal helper lookup results. Also, key-value response
values to return multiple values to Squid.
Details at 
<A HREF="http://wiki.squid-cache.org/Features/AddonHelpers">http://wiki.squid-cache.org/Features/AddonHelpers</A>.

</DL>

<H2><A NAME="removedtags"></A> <A NAME="ss3.3">3.3</A> <A HREF="#toc3.3">Removed tags</A>
</H2>

<DL>
<DT>storeurl_access<DD>
Replaced by store_id_access.

<DT>storeurl_rewrite_children<DD>
Replaced by store_id_children.

<DT>storeurl_rewrite_concurrency<DD>
Replaced by store_id_children with concurrency=N option.

<DT>storeurl_rewrite_program<DD>
Replaced by store_id_program.

</DL>

<H2><A NAME="s4">4.</A> <A HREF="#toc4">Changes to ./configure options since Squid-3.3</A></H2>

There have been some changes to Squid's build configuration since Squid-3.3.
This section gives an account of those changes in three categories:

<UL>
<LI>
<A HREF="#newoptions">New options</A></LI>
<LI>
<A HREF="#modifiedoptions">Changes to existing options</A></LI>
<LI>
<A HREF="#removedoptions">Removed options</A></LI>
</UL>

<H2><A NAME="newoptions"></A> <A NAME="ss4.1">4.1</A> <A HREF="#toc4.1">New options</A>
</H2>

<DL>
<DT>--enable-storeid-rewrite-helpers<DD>
New option to control which Store-ID helpers are built. As with other
helper options use --disable-* to prevent any helpers building and
omit to get all helper auto-detected.
Currenly only a helper using file for backend is provided.

<DT>--disable-arch-native<DD>
New option to disable use of -march=native compiler flag.
The new flag auto-enables CPU-specific optimizations in GCC and is
required by Clang++ v3.2 for correct 64-bit environment detection.
It does not always work well however, so this build option is provided
to remove it when necessary.

<DT>--with-nat-devpf<DD>
New option to alter the behaviour of http_port ... intercept option
in squid.conf.
When this option is used Squid performs the /dev/pf lookups required to
support PF rdr-to rules. Otherwise Squid will perform perform the
getsockname() API calls to support PF divert-to rules.
NOTE: systems such as NetBSD and FreeBSD which do not yet support
the getsockname() API in recent PF versions require this option.

</DL>

<H2><A NAME="modifiedoptions"></A> <A NAME="ss4.2">4.2</A> <A HREF="#toc4.2">Changes to existing options</A>
</H2>

<DL>
<DT>--enable-pf-transparent<DD>
NAT table support updated to use the getsockname() API provided by the
latest PF versions divert-to. This allows http_port
in squid.conf to support both intercept and tproxy traffic
and to silence NAT lookup failure messages on recent BSD.
NOTE: systems such as NetBSD and FreeBSD which do not yet support
the getsockname() API in recent PF versions require --with-nat-devpf
to re-enable /dev/pf support when using PF firewall.

<DT>--disable-translation<DD>
Default changed to prevent translating error page templates during build.
Use --enable-translation to explicitly build and install the templates.
The latest pre-translated templates can be downloaded from 
<A HREF="http://www.squid-cache.org/Versions/langpack/">http://www.squid-cache.org/Versions/langpack/</A>

</DL>

<H2><A NAME="removedoptions"></A> <A NAME="ss4.3">4.3</A> <A HREF="#toc4.3">Removed options</A>
</H2>

<DL>
There are no removed ./configure options in Squid-3.4.

</DL>

<H2><A NAME="s5">5.</A> <A HREF="#toc5">Regressions since Squid-2.7</A></H2>

Some squid.conf options which were available in Squid-2.7 are not yet available in Squid-3.4

If you need something to do then porting one of these from Squid-2 to Squid-3 is most welcome.

<H2><A NAME="ss5.1">5.1</A> <A HREF="#toc5.1">Missing squid.conf options available in Squid-2.7</A>
</H2>

<DL>
<DT>broken_vary_encoding<DD>
Not yet ported from 2.6

<DT>cache_dir<DD>
COSS storage type is lacking stability fixes from 2.6
COSS overwrite-percent= option not yet ported from 2.6
COSS max-stripe-waste= option not yet ported from 2.6
COSS membufs= option not yet ported from 2.6
COSS maxfullbufs= option not yet ported from 2.6

<DT>cache_peer<DD>
idle= not yet ported from 2.7
monitorinterval= not yet ported from 2.6
monitorsize= not yet ported from 2.6
monitortimeout= not yet ported from 2.6
monitorurl= not yet ported from 2.6

<DT>cache_vary<DD>
Not yet ported from 2.6

<DT>collapsed_forwarding<DD>
Not yet ported from 2.6

<DT>error_map<DD>
Not yet ported from 2.6

<DT>external_refresh_check<DD>
Not yet ported from 2.7

<DT>location_rewrite_access<DD>
Not yet ported from 2.6

<DT>location_rewrite_children<DD>
Not yet ported from 2.6

<DT>location_rewrite_concurrency<DD>
Not yet ported from 2.6

<DT>location_rewrite_program<DD>
Not yet ported from 2.6

<DT>refresh_pattern<DD>
stale-while-revalidate= not yet ported from 2.7
ignore-stale-while-revalidate= not yet ported from 2.7
negative-ttl= not yet ported from 2.7

<DT>refresh_stale_hit<DD>
Not yet ported from 2.7

<DT>update_headers<DD>
Not yet ported from 2.7

</DL>

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