/*
- * $Id$
- *
- *
- * 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) 1996-2018 The Squid Software Foundation and contributors
*
+ * Squid software is distributed under GPLv2+ license and includes
+ * contributions from numerous individuals and organizations.
+ * Please see the COPYING and CONTRIBUTORS files for details.
*/
#ifndef SQUID_ACLCHECKLIST_H
#define SQUID_ACLCHECKLIST_H
-#include "acl/Acl.h"
+#include "acl/InnerNode.h"
+#include <stack>
+#include <vector>
/// ACL checklist callback
typedef void ACLCB(allow_t, void *);
/** \ingroup ACLAPI
Base class for maintaining Squid and transaction state for access checks.
- Provides basic ACL checking methods. Its only child, ACLFilledChecklist,
- keeps the actual state data. The split is necessary to avoid exposing
+ Provides basic ACL checking methods. Its only child, ACLFilledChecklist,
+ keeps the actual state data. The split is necessary to avoid exposing
all ACL-related code to virtually Squid data types. */
class ACLChecklist
{
public:
virtual void checkForAsync(ACLChecklist *) const = 0;
virtual ~AsyncState() {}
-
- protected:
- void changeState (ACLChecklist *, AsyncState *) const;
};
class NullState : public AsyncState
static NullState _instance;
};
-
public:
ACLChecklist();
virtual ~ACLChecklist();
*
* If there are no ACLs to check at all, the result becomes ACCESS_ALLOWED.
*/
- allow_t const & fastCheck(const ACLList * list);
+ allow_t const & fastCheck(const Acl::Tree *list);
+
+ /// If slow lookups are allowed, switches into "async in progress" state.
+ /// Otherwise, returns false; the caller is expected to handle the failure.
+ bool goAsync(AsyncState *);
+
+ /// Matches (or resumes matching of) a child node while maintaning
+ /// resumption breadcrumbs if a [grand]child node goes async.
+ bool matchChild(const Acl::InnerNode *parent, Acl::Nodes::const_iterator pos, const ACL *child);
- // whether the last checked ACL of the current rule needs
- // an async operation to determine whether there was a match
- bool asyncNeeded() const;
- bool asyncInProgress() const;
- void asyncInProgress(bool const);
+ /// Whether we should continue to match tree nodes or stop/pause.
+ bool keepMatching() const { return !finished() && !asyncInProgress(); }
/// whether markFinished() was called
- bool finished() const;
+ bool finished() const { return finished_; }
+ /// async call has been started and has not finished (or failed) yet
+ bool asyncInProgress() const { return asyncStage_ != asyncNone; }
/// called when no more ACLs should be checked; sets the final answer and
/// prints a debugging message explaining the reason for that answer
void markFinished(const allow_t &newAnswer, const char *reason);
const allow_t ¤tAnswer() const { return allow_; }
- void changeState(AsyncState *);
- AsyncState *asyncState() const;
+ /// whether the action is banned or not
+ bool bannedAction(const allow_t &action) const;
+ /// add action to the list of banned actions
+ void banAction(const allow_t &action);
// XXX: ACLs that need request or reply have to use ACLFilledChecklist and
// should do their own checks so that we do not have to povide these two
// for ACL::checklistMatches to use
virtual bool hasRequest() const = 0;
virtual bool hasReply() const = 0;
+ virtual bool hasAle() const = 0;
+ virtual void syncAle() const = 0;
+
+ /// change the current ACL list
+ /// \return a pointer to the old list value (may be nullptr)
+ const Acl::Tree *changeAcl(const Acl::Tree *t) {
+ const Acl::Tree *old = accessList;
+ if (t != accessList) {
+ cbdataReferenceDone(accessList);
+ accessList = cbdataReference(t);
+ }
+ return old;
+ }
-protected:
- virtual void checkCallback(allow_t answer);
private:
- void checkAccessList();
- void checkForAsync();
+ /// Calls non-blocking check callback with the answer and destroys self.
+ void checkCallback(allow_t answer);
+
+ void matchAndFinish();
+ void changeState(AsyncState *);
+ AsyncState *asyncState() const;
+
+ const Acl::Tree *accessList;
public:
- const acl_access *accessList;
ACLCB *callback;
void *callback_data;
- /**
- * Performs non-blocking check starting with the current rule.
- * Used by nonBlockingCheck() to initiate the checks and by
- * async operation callbacks to resume checks after the async
- * operation updates the current Squid state. See nonBlockingCheck()
- * for details on final result determination.
- */
- void matchNonBlocking();
+ /// Resumes non-blocking check started by nonBlockingCheck() and
+ /// suspended until some async operation updated Squid state.
+ void resumeNonBlockingCheck(AsyncState *state);
private: /* internal methods */
+ /// Position of a child node within an ACL tree.
+ class Breadcrumb
+ {
+ public:
+ Breadcrumb(): parent(NULL) {}
+ Breadcrumb(const Acl::InnerNode *aParent, Acl::Nodes::const_iterator aPos): parent(aParent), position(aPos) {}
+ bool operator ==(const Breadcrumb &b) const { return parent == b.parent && (!parent || position == b.position); }
+ bool operator !=(const Breadcrumb &b) const { return !this->operator ==(b); }
+ void clear() { parent = NULL; }
+ const Acl::InnerNode *parent; ///< intermediate node in the ACL tree
+ Acl::Nodes::const_iterator position; ///< child position inside parent
+ };
+
/// possible outcomes when trying to match a single ACL node in a list
typedef enum { nmrMatch, nmrMismatch, nmrFinished, nmrNeedsAsync }
- NodeMatchingResult;
+ NodeMatchingResult;
/// prepare for checking ACLs; called once per check
void preCheck(const char *what);
- bool matchAclList(const ACLList * list, bool const fast);
- bool matchNodes(const ACLList * head, bool const fast);
- NodeMatchingResult matchNode(const ACLList &node, bool const fast);
- void calcImplicitAnswer(const allow_t &lastSeenAction);
+ bool prepNonBlocking();
+ void completeNonBlocking();
+ void calcImplicitAnswer();
- bool async_;
+ bool asyncCaller_; ///< whether the caller supports async/slow ACLs
+ bool occupied_; ///< whether a check (fast or non-blocking) is in progress
bool finished_;
allow_t allow_;
- AsyncState *state_;
- bool checking_;
- bool checking() const;
- void checking (bool const);
+ enum AsyncStage { asyncNone, asyncStarting, asyncRunning, asyncFailed };
+ AsyncStage asyncStage_;
+ AsyncState *state_;
+ Breadcrumb matchLoc_; ///< location of the node running matches() now
+ Breadcrumb asyncLoc_; ///< currentNode_ that called goAsync()
+ unsigned asyncLoopDepth_; ///< how many times the current async state has resumed
bool callerGone();
+
+ /// suspended (due to an async lookup) matches() in the ACL tree
+ std::stack<Breadcrumb> matchPath;
+ /// the list of actions which must ignored during acl checks
+ std::vector<allow_t> bannedActions_;
};
#endif /* SQUID_ACLCHECKLIST_H */
+