doc/release-notes/release-3.1.html

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   8 <H1>Squid 3.1.PRE1 release notes</H1>
   9
  10 <H2>Squid Developers</H2>$Id: release-3.1.html,v 1.5 2008/01/17 10:09:05 hno Exp $
  11 <HR>
  12 <EM>This document contains the release notes for version 3.1 of Squid.
  13 Squid is a WWW Cache application developed by the National Laboratory
  14 for Applied Network Research and members of the Web Caching community.</EM>
  15 <HR>
  16 <H2><A NAME="s1">1. Notice</A></H2>
  17
  18 <P>The Squid Team are pleased to announce the release of Squid-3.1.PRE1 for pre-release testing.</P>
  19 <P>This new release is available for download from
  20 <A HREF="http://www.squid-cache.org/Versions/v3/3.1/">http://www.squid-cache.org/Versions/v3/3.1/</A> or the
  21 <A HREF="http://www.squid-cache.org/Mirrors/http-mirrors.html">mirrors</A>.</P>
  22 <P>A large number of the show-stopper bugs have been fixed along with general improvements to the ICAP support.
  23 While this release is not deemed ready for production use, we believe it is ready for wider testing by the community.</P>
  24 <P>We welcome feedback and bug reports. If you find a bug, please see
  25 <A HREF="http://wiki.squid-cache.org/SquidFaq/TroubleShooting#head-7067fc0034ce967e67911becaabb8c95a34d576d">http://wiki.squid-cache.org/SquidFaq/TroubleShooting#head-7067fc0034ce967e67911becaabb8c95a34d576d</A> for how to submit a report with a stack trace.</P>
  26
  27 <H2><A NAME="s2">2. Known issues</A></H2>
  28
  29 <P>Although this release is deemed good enough for testing in many setups, please note the existence of
  30 <A HREF="http://www.squid-cache.org/bugs/buglist.cgi?query_format=advanced&amp;short_desc_type=allwordssubstr&amp;short_desc=&amp;target_milestone=3.1&amp;long_desc_type=allwordssubstr&amp;long_desc=&amp;bug_file_loc_type=allwordssubstr&amp;bug_file_loc=&amp;status_whiteboard_type=allwordssubstr&amp;status_whiteboard=&amp;bug_status=NEW&amp;bug_status=ASSIGNED&amp;bug_status=REOPENED&amp;emailtype1=substring&amp;email1=&amp;emailtype2=substring&amp;email2=&amp;bugidtype=include&amp;bug_id=&amp;votes=&amp;chfieldfrom=&amp;chfieldto=Now&amp;chfieldvalue=&amp;cmdtype=doit&amp;order=bugs.bug_severity&amp;field0-0-0=noop&amp;type0-0-0=noop&amp;value0-0-0=">open bugs against Squid-3.1</A>.</P>
  31
  32 <H2><A NAME="s3">3. Changes since earlier PRE releases of Squid-3.1</A></H2>
  33
  34 <P>The 3.1 change history can be
  35 <A HREF="http://www.squid-cache.org/Versions/v3/3.1/changesets/">viewed here</A>.</P>
  36
  37 <H2><A NAME="s4">4. Changes since Squid-3.0</A></H2>
  38
  39 <H2><A NAME="ss4.1">4.1 Major new features</A>
  40 </H2>
  41
  42 <P>Squid 3.1 represents a new feature release above 3.0.</P>
  43 <P>The most important of these new features are:</P>
  44 <P>
  45 <UL>
  46 <LI>IPv6 Support</LI>
  47 </UL>
  48 </P>
  49 <P>Most user-facing changes are reflected in squid.conf (see below).</P>
  50
  51 <H3>Internet Protocol version 6 (IPv6)</H3>
  52
  53 <P>Squid 3.1 supports IPv6. To enable IPv6 support, use the ./configure --enable-ipv6 option</P>
  54
  55 <H3>New Features for IPv6</H3>
  56
  57 <P>Squid handles localhost values seperately. For the purpose of ACLs and also external
  58 connections ::1 is considered a seperate IP from 127.0.0.1. This means all ACL which
  59 define behaviour for localhost may need ::1/128 included.</P>
  60
  61 <P>--with-localhost-ipv6 option is provided for Pure-IPv6 setups who do not want to be
  62 bothered by the localhost vagaries. It will enable logics to map all localhost traffic
  63 through ::1 unless an IPv4-only link is required.</P>
  64
  65 <P>Additional ./configure --with-ipv4-mapped option is provided for OS that require a socket setting
  66 to accept IPv4 addresses on IPv6 sockets, squid performs v4-mapping on these addresses
  67 It is intended primarily to be used for Windows Vista builds.</P>
  68
  69 <P>Pinger has been upgraded to perform both ICMP and ICMPv6 as required.
  70 As a result of this and due to a change in the binary protocol format between them,
  71 new builds of squid are no longer backwards-compatible with old pinger binaries.
  72 You will need to perform "make install-pinger" again after installing squid.</P>
  73
  74 <P>Peer and Client SNMP tables have been altered to handle IPv6 addresses.
  75 As a side effect of this the long-missing fix to show seperate named peers on one IP
  76 has been integrated. Making the SNMP peer table now produce correct output.
  77 The table structure change is identical for both IPv4-only and Dual modes but with
  78 IPv4-only simply not including any IP6 entries. This means any third-party SNMP
  79 software which hard coded the MIB paths needs to be upgraded for this Squid release.</P>
  80
  81
  82 <H3>Limitations of IPv6 Support</H3>
  83
  84 <P>Specify a specific tcp_outgoing_address and the clients who match its ACL are limited
  85 to the IPv4 or IPv6 network that address belongs to. They are not permitted over the
  86 IPv4-IPv6 boundary. Some ACL voodoo can however be applied to explicitly route the
  87 IPv6/IPv4 bound traffic out an appropriate interface.
  88 <PRE>
  89     acl toIP6 dst ipv6
  90     tcp_outgoing_address 2001::1 toIP6
  91     tcp_outgoing_address 10.0.0.1 !toIP6
  92 </PRE>
  93 </P>
  94
  95 <P>WCCP is not available (neither version 1 or 2). It remains built into squid for use with IPv4 traffic but IPv6 cannot use it.</P>
  96
  97 <P>Transparent/Interception is done via NAT at the OS level and is not available in IPv6.
  98 Squid will ensure that any port set with transparent or tproxy options be an IPv4-only
  99 listening address. Wildcard can still be used but will not open as an IPv6.
 100 To ensure that squid can accept IPv6 traffic on its default port, an alternative should
 101 be chosen to handle transparent traffic.
 102 <PRE>
 103    http_port 3128
 104    http_port 8080 transparent
 105 </PRE>
 106 </P>
 107
 108 <P>The bundled NTLM Auth helper is IPv4-native between itself and the NTLM server.
 109 A new one will be needed for IPv6 traffic between the helper and server.</P>
 110
 111 <P>The bundled RADIUS Auth helper is IPv4-native, both in traffic between and data storage
 112 with the RADIUS server. A new helper will be needed for IPv6 RADIUS protocol.</P>
 113
 114
 115 <H2><A NAME="ss4.2">4.2 Changes to squid.conf</A>
 116 </H2>
 117
 118 <P>There have been changes to Squid's configuration file since Squid-3.0.</P>
 119 <P>This section gives a thorough account of those changes in three categories:</P>
 120 <P>
 121 <UL>
 122 <LI>
 123 <A HREF="#newtags">New tags</A></LI>
 124 <LI>
 125 <A HREF="#modifiedtags">Changes to existing tags</A></LI>
 126 <LI>
 127 <A HREF="#removedtags">Removed tags</A></LI>
 128 </UL>
 129 </P>
 130
 131
 132
 133
 134 <H3><A NAME="newtags"></A> New tags</H3>
 135
 136 <P>
 137 <DL>
 138 <DT><B>pinger_enable</B><DD><P>New option to enable/disable the ICMP pinger helper with a reconfigure instead of a full rebuild.
 139 <PRE>
 140         Control whether the pinger is active at run-time.
 141         Enables turning ICMP pinger on and off with a simple squid -k reconfigure.
 142         default is on when --enable-icmp is compiled in.
 143
 144 </PRE>
 145 </P>
 146
 147 <DT><B>dns_v4_fallback</B><DD><P>New option to prevent squid from always looking up IPv4 regardless of whether IPv6 addresses are found.
 148 Squid will follow a policy of prefering IPv6 links, keeping the IPv4 only as a safety net behind IPv6.
 149 <PRE>
 150         Standard practice with DNS is to lookup either A or AAAA records
 151         and use the results if it succeeds. Only looking up the other if
 152         the first attempt fails or otherwise produces no results.
 153
 154         That policy however will cause squid to produce error pages for some
 155         servers that advertise AAAA but are unreachable over IPv6.
 156
 157         If this is ON  squid will always lookup both AAAA and A, using both.
 158         If this is OFF squid will lookup AAAA and only try A if none found.
 159
 160         WARNING: There are some possibly unwanted side-effects with this on:
 161                 *) Doubles the load placed by squid on the DNS network.
 162                 *) May negatively impact connection delay times.
 163
 164 </PRE>
 165 </P>
 166
 167 <DT><B>include</B><DD><P>New option to import entire secondary configuration files into squid.conf.
 168 <PRE>
 169         Squid will follow the files immediately and insert all their content
 170         as if it was at that position in squid.conf. As per squid.conf some
 171         options are order-specific within the config as a whole.
 172
 173         A few layers of include are allowed, but too many are confusing and
 174         squid will enforce an include depth of 16 files.
 175
 176         Syntax:
 177                 include /path/to/file1 /path/to/file2
 178
 179 </PRE>
 180 </P>
 181
 182 </DL>
 183 </P>
 184
 185 <H3><A NAME="modifiedtags"></A> Changes to existing tags</H3>
 186
 187 <P>
 188 <DL>
 189 <DT><B>acl dst ipvs</B><DD><P>New preset content - ipv6 - available as a preset type in the src and dst ACL matching all of the public IPv6 network space.
 190 <PRE>
 191         acl aclname dst ipv6
 192
 193 </PRE>
 194 </P>
 195
 196 <DT><B>http(s)_port name= option</B><DD><P>New port option to assign internal names to listening ports
 197 <PRE>
 198            name=        Specifies a internal name for the port. Defaults to
 199                         the port specification (port or addr:port)
 200
 201 </PRE>
 202 </P>
 203
 204 <DT><B>acl myportname</B><DD><P>New acl type myportname, matching the name of the http(s)_port where the request was accepted
 205 <PRE>
 206         acl aclname myportname 3128 ...         # http(s)_port name
 207
 208 </PRE>
 209 </P>
 210
 211
 212 <DT><B>external_acl_type</B><DD><P>New options 'ipv4' and 'ipv6' are added to set the IPv4/v6 protocol between squid and its helpers.
 213 Please be aware of some limits to these options. These options only affet the transport protocol used
 214 to send data to and from the helpers. Squid in IPv6-mode may still send %SRC addresses in IPv4 or IPv6
 215 format, so all helpers will need to be checked and converted to cope with such information cleanly.
 216 <PRE>
 217           ipv4 / ipv6   IP-mode used to communicate to this helper.
 218                         For compatability with older configurations and helpers
 219                         'ipv4' is the default unless --with-localhost-ipv6 is used.
 220                         --with-localhost-ipv6 changes the default to 'ipv6'.
 221                         SPECIAL NOTE: explicit use of these options override --with-localhost-ipv6
 222
 223 </PRE>
 224 </P>
 225
 226 <DT><B>tcp_outgoing_address</B><DD><P>This option causes some problems when bridging IPv4 and IPv6. A workaround has been provided.
 227 <PRE>
 228         Squid is built with a capability of bridging the IPv4 and IPv6 internets.
 229         tcp_outgoing_address as previously used breaks this bridging by forcing
 230         all outbound traffic through a certain IPv4 which may be on the wrong
 231         side of the IPv4/IPv6 boundary.
 232
 233         To operate with tcp_outgoing_address and keep the bridging benefits
 234         an additional ACL needs to be used which ensures the IPv6-bound traffic
 235         is never forced or permitted out the IPv4 interface.
 236
 237         acl to_ipv6 dst ipv6
 238         tcp_outgoing_address 2002::c001 good_service_net to_ipv6
 239         tcp_outgoing_address 10.0.0.2 good_service_net !to_ipv6
 240
 241         tcp_outgoing_address 2002::beef normal_service_net to_ipv6
 242         tcp_outgoing_address 10.0.0.1 normal_service_net !to_ipv6
 243
 244         tcp_outgoing_address 2002::1 to_ipv6
 245         tcp_outgoing_address 10.0.0.3 !to_ipv6
 246
 247 </PRE>
 248 </P>
 249
 250 <DT><B>balance_on_multiple_ip</B><DD><P>The previous default behavour (rotate per-request) of this setting causes failover clashes with IPv6 built-in mechanisms.
 251 It has thus been turned off by default. Making the 'best choice' IP continue in use for any hostname until it encounters a connection failure and failover drops to the next known IP.
 252 <PRE>
 253        Modern IP resolvers in squid sort lookup results by preferred access.
 254        By default squid will use these IP in order and only rotates to
 255        the next listed when the most preffered fails.
 256
 257        Some load balancing servers based on round robin DNS have been
 258        found not to preserve user session state across requests
 259        to different IP addresses.
 260
 261        Enabling this directive Squid rotates IP's per request.
 262
 263 </PRE>
 264 </P>
 265
 266 </DL>
 267 </P>
 268
 269
 270 <H3><A NAME="removedtags"></A> Removed tags</H3>
 271
 272 <P>
 273 <DL>
 274
 275 </DL>
 276 </P>
 277
 278
 279 <H2><A NAME="ss4.3">4.3 Changes to ./configure Options</A>
 280 </H2>
 281
 282 <P>There have been some changes to Squid's build configuration since Squid-3.0.</P>
 283 <P>This section gives an account of those changes in three categories:</P>
 284 <P>
 285 <UL>
 286 <LI>
 287 <A HREF="#newoptions">New options</A></LI>
 288 <LI>
 289 <A HREF="#modifiedoptions">Changes to existing options</A></LI>
 290 <LI>
 291 <A HREF="#notportedoptions">Not yet available options</A></LI>
 292 <LI>
 293 <A HREF="#removedoptions">Removed options</A></LI>
 294 </UL>
 295 </P>
 296
 297
 298
 299 <H3><A NAME="newoptions"></A> New options</H3>
 300
 301 <P>
 302 <DL>
 303 <DT><B>--enable-ipv6</B><DD><P>Buildwith IPv6 support. The default is to build without.</P>
 304
 305 <DT><B>--with-localhost-ipv6</B><DD><P>Build support for squid to map all 127.0.0.1 traffic onto ::1.
 306 The default is to build with 127.0.0.1 and ::1 being considered seperate IP.
 307 see the IPv6 details above for a better description. </P>
 308
 309 <DT><B>--with-ipv6-split-stack</B><DD><P>Enable special additions for IPv6 support in Windows XP.
 310 see the IPv6 details above for a better description.</P>
 311
 312 <DT><B>--with-ipv4-mapped</B><DD><P>Enable special additions for IPv6 support in Windows Vista.
 313 see the IPv6 details above for a better description.</P>
 314
 315 <DT><B>--with-dns-cname</B><DD><P>Enable CNAME recursion within the Internal DNS resolver stub squid uses.
 316 This has no effect on the external DNS helper.
 317 Please note this extension is still experimental and may encounter problems.
 318 To see if it is actually needed you can run squid without it for a period and
 319 check the CNAME-Only Requests statistics squid maintains.
 320 If it produces ongoing serious problems the external helper may be needed
 321 but please report the bugs anyway.</P>
 322
 323 </DL>
 324 </P>
 325 <H3><A NAME="modifiedoptions"></A> Changes to existing options</H3>
 326
 327 <P>
 328 <DL>
 329 <DT><B>--disable-internl-dns</B><DD><P>Better support for Linux using the external DNS helper.
 330 The helper will compile and work with dns_nameservers on more variants of Linux than previously.</P>
 331
 332 </DL>
 333 </P>
 334 <H3><A NAME="notportedoptions"></A> Not yet available options</H3>
 335
 336 <P>These configure options have not yet been ported to Squid-3. If you need something to do then
 337 porting one of these from Squid-2 to Squid-3 is most welcome.</P>
 338 <P>
 339 <DL>
 340 <DT><B>--enable-devpoll</B><DD><P>Support for Solaris /dev/poll</P>
 341
 342 <DT><B>--enable-select-simple</B><DD><P>Basic POSIX select() loop without any binary fd_set optimizations.</P>
 343
 344 <DT><B>--enable-follow-x-forwarded-for</B><DD><P>Support following the X-Forwarded-For HTTP header for determining the
 345 client IP address</P>
 346 </DL>
 347 </P>
 348
 349 <H3><A NAME="removedoptions"></A> Removed options</H3>
 350
 351 <P>The following configure options have been removed.</P>
 352 <P>
 353 <DL>
 354
 355 </DL>
 356 </P>
 357
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