securityd/src/notifications.h

   1 /*
   2  * Copyright (c) 2000-2004,2006-2008 Apple Inc. All Rights Reserved.
   3  *
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   6  * This file contains Original Code and/or Modifications of Original Code
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   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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  23
  24
  25 //
  26 // notifications - handling of securityd-gated notification messages
  27 //
  28 #ifndef _H_NOTIFICATIONS
  29 #define _H_NOTIFICATIONS
  30
  31 #include <security_utilities/mach++.h>
  32 #include <security_utilities/machserver.h>
  33 #include <security_utilities/globalizer.h>
  34 #include <securityd_client/ssclient.h>
  35 #include "SharedMemoryCommon.h"
  36 #include <map>
  37 #include <queue>
  38
  39 #include "SharedMemoryServer.h"
  40
  41 using MachPlusPlus::Port;
  42 using MachPlusPlus::MachServer;
  43 using SecurityServer::NotificationDomain;
  44 using SecurityServer::NotificationEvent;
  45 using SecurityServer::NotificationMask;
  46
  47 class SharedMemoryListener;
  48
  49 //
  50 // A registered receiver of notifications.
  51 // This is an abstract class; you must subclass to define notifyMe().
  52 //
  53 // All Listeners in existence are collected in an internal map of ports to
  54 // Listener*s, which makes them eligible to have events delivered to them via
  55 // their notifyMe() method. There are (only) two viable lifetime management
  56 // strategies for your Listener subclass:
  57 // (1) Eternal: don't ever destroy your Listener. All is well. By convention,
  58 // such Listeners use the null port.
  59 // (2) Port-based: To get rid of your Listeners, call Listener::remove(port),
  60 // which will delete(!) all Listeners constructed with that port.
  61 // Except for the remove() functionality, Listener does not interpret the port.
  62 //
  63 // If you need another Listener lifetime management strategy, you will probably
  64 // have to change things around here.
  65 //
  66 class Listener: public RefCount {
  67 public:
  68         Listener(NotificationDomain domain, NotificationMask events,
  69                 mach_port_t port = MACH_PORT_NULL);
  70         virtual ~Listener();
  71
  72         // inject an event into the notification system
  73     static void notify(NotificationDomain domain,
  74                 NotificationEvent event, const CssmData &data);
  75     static void notify(NotificationDomain domain,
  76                 NotificationEvent event, uint32 sequence, const CssmData &data, audit_token_t auditToken);
  77     static bool remove(Port port);
  78
  79     const NotificationDomain domain;
  80     const NotificationMask events;
  81
  82         bool wants(NotificationEvent event)
  83         { return (1 << event) & events; }
  84
  85 protected:
  86         class Notification : public RefCount {
  87         public:
  88                 Notification(NotificationDomain domain, NotificationEvent event,
  89                         uint32 seq, const CssmData &data);
  90                 virtual ~Notification();
  91
  92                 const NotificationDomain domain;
  93                 const NotificationEvent event;
  94                 const uint32 sequence;
  95                 const CssmAutoData data;
  96
  97         std::string description() const;
  98                 size_t size() const
  99                 { return data.length(); }       //@@@ add "slop" here for heuristic?
 100         };
 101
 102         virtual void notifyMe(Notification *message) = 0;
 103
 104     static bool testPredicate(const std::function<bool(const Listener& listener)> test);
 105
 106 public:
 107         class JitterBuffer {
 108         public:
 109                 JitterBuffer() : mNotifyLast(0) { }
 110
 111                 bool inSequence(Notification *message);
 112                 RefPointer<Notification> popNotification();
 113
 114         private:
 115                 uint32 mNotifyLast;             // last notification seq processed
 116                 typedef std::map<uint32, RefPointer<Notification> > JBuffer;
 117                 JBuffer mBuffer;                // early messages buffer
 118         };
 119
 120 private:
 121         static void sendNotification(Notification *message);
 122
 123 private:
 124     typedef multimap<mach_port_t, RefPointer<Listener> > ListenerMap;
 125     static ListenerMap& listeners;
 126     static Mutex setLock;
 127 };
 128
 129
 130
 131 class SharedMemoryListener : public Listener, public SharedMemoryServer, public Security::MachPlusPlus::MachServer::Timer
 132 {
 133 protected:
 134         virtual void action ();
 135         virtual void notifyMe(Notification *message);
 136
 137     static bool findUID(uid_t uid);
 138     static int get_process_euid(pid_t pid, uid_t& out_euid);
 139
 140     bool needsPrivacyFilter(Notification *notification);
 141     bool isTrustEvent(Notification *notification);
 142     uint32 getRecordType(const CssmData& val) const;
 143
 144         bool mActive;
 145
 146     Mutex mMutex;
 147
 148 public:
 149         SharedMemoryListener (const char* serverName, u_int32_t serverSize, uid_t uid = 0, gid_t gid = 0);
 150         virtual ~SharedMemoryListener ();
 151
 152     static void createDefaultSharedMemoryListener(uid_t uid, gid_t gid);
 153 };
 154
 155 #endif