From: Amos Jeffries <squid3@treenet.co.nz>
Date: Sun, 1 Nov 2009 07:48:25 +0000 (+1300)
Subject: Bug 1239: Much needed ACL type random
X-Git-Tag: SQUID_3_2_0_1~632
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cb1b906f6c151e444e1ed0c62928bebd01342c3b;p=thirdparty%2Fsquid.git

Bug 1239: Much needed ACL type random
---

diff --git a/doc/release-notes/release-3.2.sgml b/doc/release-notes/release-3.2.sgml
index 36c6affe96..23762d63d4 100644
--- a/doc/release-notes/release-3.2.sgml
+++ b/doc/release-notes/release-3.2.sgml
@@ -314,6 +314,9 @@ This section gives a thorough account of those changes in three categories:
 <sect1>Changes to existing tags<label id="modifiedtags">
 <p>
 <descrip>
+	<tag>acl random</tag>
+	<p>New type <em>random</em>. Pseudo-randomly match requests based on a configured probability.
+
 	<tag>deny_info</tag>
 	<p>Support URL format tags. For dynamically generated URL in denial redirect.
 
diff --git a/src/AclRegs.cc b/src/AclRegs.cc
index 82ca1b99f2..7dc4ea4207 100644
--- a/src/AclRegs.cc
+++ b/src/AclRegs.cc
@@ -38,6 +38,7 @@
 #include "acl/PeerName.h"
 #include "acl/ProtocolData.h"
 #include "acl/Protocol.h"
+#include "acl/Random.h"
 #include "acl/Referer.h"
 #include "acl/RegexData.h"
 #include "acl/ReplyHeaderStrategy.h"
@@ -104,6 +105,8 @@ ACL::Prototype ACLPeerName::RegistryProtoype(&ACLPeerName::RegistryEntry_, "peer
 ACLStrategised<const char *> ACLPeerName::RegistryEntry_(new ACLStringData, ACLPeerNameStrategy::Instance(), "peername");
 ACL::Prototype ACLProtocol::RegistryProtoype(&ACLProtocol::RegistryEntry_, "proto");
 ACLStrategised<protocol_t> ACLProtocol::RegistryEntry_(new ACLProtocolData, ACLProtocolStrategy::Instance(), "proto");
+ACL::Prototype ACLRandom::RegistryProtoype(&ACLRandom::RegistryEntry_, "random");
+ACLRandom ACLRandom::RegistryEntry_("random");
 ACL::Prototype ACLReferer::RegistryProtoype(&ACLReferer::RegistryEntry_, "referer_regex");
 ACLStrategised<char const *> ACLReferer::RegistryEntry_(new ACLRegexData, ACLRequestHeaderStrategy<HDR_REFERER>::Instance(), "referer_regex");
 ACL::Prototype ACLReplyMIMEType::RegistryProtoype(&ACLReplyMIMEType::RegistryEntry_, "rep_mime_type");
diff --git a/src/acl/Makefile.am b/src/acl/Makefile.am
index 500378457e..8b861e3d34 100644
--- a/src/acl/Makefile.am
+++ b/src/acl/Makefile.am
@@ -79,6 +79,8 @@ libacls_la_SOURCES = \
 	ProtocolData.cc \
 	ProtocolData.h \
 	Protocol.h \
+	Random.cc \
+	Random.h \
 	Referer.cc \
 	Referer.h \
 	ReplyHeaderStrategy.h \
diff --git a/src/acl/Random.cc b/src/acl/Random.cc
new file mode 100644
index 0000000000..9d7744606e
--- /dev/null
+++ b/src/acl/Random.cc
@@ -0,0 +1,132 @@
+/*
+ * DEBUG: section 28    Access Control
+ * AUTHOR: Amos Jeffries
+ *
+ * SQUID Web Proxy Cache          http://www.squid-cache.org/
+ * ----------------------------------------------------------
+ *
+ *  Squid is the result of efforts by numerous individuals from
+ *  the Internet community; see the CONTRIBUTORS file for full
+ *  details.   Many organizations have provided support for Squid's
+ *  development; see the SPONSORS file for full details.  Squid is
+ *  Copyrighted (C) 2001 by the Regents of the University of
+ *  California; see the COPYRIGHT file for full details.  Squid
+ *  incorporates software developed and/or copyrighted by other
+ *  sources; see the CREDITS file for full details.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
+ *
+ *
+ * Copyright (c) 2003, Robert Collins <robertc@squid-cache.org>
+ */
+
+#include "squid.h"
+
+#include "acl/FilledChecklist.h"
+#include "acl/Random.h"
+#include "wordlist.h"
+
+ACL *
+ACLRandom::clone() const
+{
+    return new ACLRandom(*this);
+}
+
+ACLRandom::ACLRandom (char const *theClass) : data (NULL), class_ (theClass)
+{
+    memset(pattern, 0 , sizeof(pattern));
+}
+
+ACLRandom::ACLRandom (ACLRandom const & old) : data (old.data), class_ (old.class_)
+{
+    /* we don't have copy constructors for the data yet */
+    assert (!old.data);
+    memcpy(pattern, old.pattern, sizeof(pattern));
+}
+
+ACLRandom::~ACLRandom()
+{ }
+
+char const *
+ACLRandom::typeString() const
+{
+    return class_;
+}
+
+bool
+ACLRandom::empty () const
+{
+    return data == 0.0;
+}
+
+/*******************/
+/* aclParseRandomList */
+/*******************/
+void
+ACLRandom::parse()
+{
+    char *t = NULL;
+    char bufa[256], bufb[256];
+
+    t = strtokFile();
+    debugs(28, 5, "aclParseRandomData: " << t);
+
+    // seed random generator ...
+    srand(time(NULL));
+
+    if (sscanf(t, "%[0-9]:%[0-9]", bufa, bufb) == 2) {
+        int a = xatoi(bufa);
+        int b = xatoi(bufb);
+        if (a == 0 || b == 0) {
+            debugs(28, 0, "aclParseRandomData: Bad Pattern: '" << t << "'");
+            self_destruct();
+        } else
+            data = a / (double)(a+b);
+    } else if (sscanf(t, "%[0-9]/%[0-9]", bufa, bufb) == 2) {
+        int a = xatoi(bufa);
+        int b = xatoi(bufb);
+        if (a == 0 || b == 0) {
+            debugs(28, 0, "aclParseRandomData: Bad Pattern: '" << t << "'");
+            self_destruct();
+        } else
+            data = (double) a / (double) b;
+    } else if (sscanf(t, "0.%[0-9]", bufa) == 1) {
+        data = atof(t);
+    } else {
+        debugs(28, 0, "aclParseRandomData: Bad Pattern: '" << t << "'");
+        self_destruct();
+    }
+
+    // save the exact input pattern. so we can display it later.
+    memcpy(pattern, t, min(sizeof(pattern)-1,strlen(t)));
+}
+
+int
+ACLRandom::match(ACLChecklist *cl)
+{
+    // make up the random value
+    double random = ((double)rand() / (double)RAND_MAX);
+
+    debugs(28, 3, "ACL Random: " << name << " " << pattern << " test: " << data << " > " << random << " = " << ((data > random)?"MATCH":"NO MATCH") );
+    return (data > random)?1:0;
+}
+
+wordlist *
+ACLRandom::dump() const
+{
+    wordlist *w = NULL;
+    wordlistAdd(&w, pattern);
+    return w;
+}
diff --git a/src/acl/Random.h b/src/acl/Random.h
new file mode 100644
index 0000000000..7ebf3e9d4b
--- /dev/null
+++ b/src/acl/Random.h
@@ -0,0 +1,67 @@
+/*
+ * SQUID Web Proxy Cache          http://www.squid-cache.org/
+ * ----------------------------------------------------------
+ *
+ *  Squid is the result of efforts by numerous individuals from
+ *  the Internet community; see the CONTRIBUTORS file for full
+ *  details.   Many organizations have provided support for Squid's
+ *  development; see the SPONSORS file for full details.  Squid is
+ *  Copyrighted (C) 2001 by the Regents of the University of
+ *  California; see the COPYRIGHT file for full details.  Squid
+ *  incorporates software developed and/or copyrighted by other
+ *  sources; see the CREDITS file for full details.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
+ *
+ *
+ * Copyright (c) 2003, Robert Collins <robertc@squid-cache.org>
+ */
+
+#ifndef SQUID_ACL_RANDOM_H
+#define SQUID_ACL_RANDOM_H
+
+#include "acl/Acl.h"
+#include "acl/Checklist.h"
+
+/// \ingroup ACLAPI
+class ACLRandom : public ACL
+{
+
+public:
+    MEMPROXY_CLASS(ACLRandom);
+
+    ACLRandom(char const *);
+    ACLRandom(ACLRandom const &);
+    ~ACLRandom();
+    ACLRandom&operator=(ACLRandom const &);
+
+    virtual ACL *clone()const;
+    virtual char const *typeString() const;
+    virtual void parse();
+    virtual int match(ACLChecklist *checklist);
+    virtual wordlist *dump() const;
+    virtual bool empty () const;
+
+protected:
+    static Prototype RegistryProtoype;
+    static ACLRandom RegistryEntry_;
+    double data;        // value to be exceeded before this ACL will match
+    char pattern[256];  // pattern from config file. Used to generate 'data'
+    char const *class_;
+};
+
+MEMPROXY_CLASS_INLINE(ACLRandom);
+
+#endif /* SQUID_ACL_RANDOM_H */
diff --git a/src/cf.data.pre b/src/cf.data.pre
index 4efce5b758..b24b122174 100644
--- a/src/cf.data.pre
+++ b/src/cf.data.pre
@@ -636,6 +636,11 @@ DOC_START
 	  # clients may appear to come from multiple addresses if they are
 	  # going through proxy farms, so a limit of 1 may cause user problems.
 
+	acl aclname random probability
+	  # Pseudo-randomly match requests. Based on the probability given.
+	  # Probability may be written as a decimal (0.333), fraction (1/3)
+	  # or ratio of matches:non-matches (3:5).
+
 	acl aclname req_mime_type [-i] mime-type ...
 	  # regex match against the mime type of the request generated
 	  # by the client. Can be used to detect file upload or some