src/acl/Tree.h

   1 /*
   2  * Copyright (C) 1996-2021 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #ifndef SQUID_ACL_TREE_H
  10 #define SQUID_ACL_TREE_H
  11
  12 #include "acl/BoolOps.h"
  13 #include "sbuf/List.h"
  14
  15 namespace Acl
  16 {
  17
  18 /// An ORed set of rules at the top of the ACL expression tree, providing two
  19 /// unique properties: cbdata protection and optional rule actions.
  20 class Tree: public OrNode
  21 {
  22     // XXX: We should use refcounting instead, but it requires making ACLs
  23     // refcounted as well. Otherwise, async lookups will reach deleted ACLs.
  24     CBDATA_CLASS(Tree);
  25
  26 public:
  27     /// dumps <name, action, rule, new line> tuples
  28     /// the supplied converter maps action.kind to a string
  29     template <class ActionToStringConverter>
  30     SBufList treeDump(const char *name, ActionToStringConverter converter) const;
  31
  32     /// Returns the corresponding action after a successful tree match.
  33     Answer winningAction() const;
  34
  35     /// what action to use if no nodes matched
  36     Answer lastAction() const;
  37
  38     /// appends and takes control over the rule with a given action
  39     void add(ACL *rule, const Answer &action);
  40     void add(ACL *rule); ///< same as InnerNode::add()
  41
  42 protected:
  43     /// Acl::OrNode API
  44     virtual bool bannedAction(ACLChecklist *, Nodes::const_iterator) const override;
  45     Answer actionAt(const Nodes::size_type pos) const;
  46
  47     /// if not empty, contains actions corresponding to InnerNode::nodes
  48     typedef std::vector<Answer> Actions;
  49     Actions actions;
  50 };
  51
  52 inline const char *
  53 AllowOrDeny(const Answer &action)
  54 {
  55     return action.allowed() ? "allow" : "deny";
  56 }
  57
  58 template <class ActionToStringConverter>
  59 inline SBufList
  60 Tree::treeDump(const char *prefix, ActionToStringConverter converter) const
  61 {
  62     SBufList text;
  63     Actions::const_iterator action = actions.begin();
  64     typedef Nodes::const_iterator NCI;
  65     for (NCI node = nodes.begin(); node != nodes.end(); ++node) {
  66
  67         text.push_back(SBuf(prefix));
  68
  69         if (action != actions.end()) {
  70             static const SBuf DefaultActString("???");
  71             const char *act = converter(*action);
  72             text.push_back(act ? SBuf(act) : DefaultActString);
  73             ++action;
  74         }
  75
  76         text.splice(text.end(), (*node)->dump());
  77         text.push_back(SBuf("\n"));
  78     }
  79     return text;
  80 }
  81
  82 } // namespace Acl
  83
  84 #endif /* SQUID_ACL_TREE_H */
  85