src/connection.cpp

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All Rights Reserved.
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   8  * Version 2.0 (the 'License'). You may not use this file except in
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  10  * http://www.opensource.apple.com/apsl/ and read it before using this
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  23
  24
  25 //
  26 // connection - manage connections to clients.
  27 //
  28 // Note that Connection objects correspond to client process threads, and are
  29 // thus inherently single-threaded. It is physically impossible for multiple
  30 // requests to come in for the same Connection, unless the client side is
  31 // illegally messing with the IPC protocol (for which we check below).
  32 // It is still necessary to take the object lock for a Connection because there
  33 // are times when we want to manipulate a busy Connection from another securityd
  34 // thread (say, in response to a DPN).
  35 //
  36 #include "connection.h"
  37 #include "key.h"
  38 #include "server.h"
  39 #include "session.h"
  40 #include <security_cdsa_client/keyclient.h>
  41 #include <security_cdsa_client/genkey.h>
  42 #include <security_cdsa_client/wrapkey.h>
  43 #include <security_cdsa_client/signclient.h>
  44 #include <security_cdsa_client/macclient.h>
  45 #include <security_cdsa_client/cryptoclient.h>
  46
  47
  48 //
  49 // Construct a Connection object.
  50 //
  51 Connection::Connection(Process &proc, Port rPort)
  52  : mClientPort(rPort), state(idle), agentWait(NULL),
  53    aclUpdateTrigger(NULL)
  54 {
  55         parent(proc);
  56
  57         // bump the send-rights count on the reply port so we keep the right after replying
  58         mClientPort.modRefs(MACH_PORT_RIGHT_SEND, +1);
  59
  60         secdebug("SS", "New connection %p for process %d clientport=%d",
  61                 this, process().pid(), int(rPort));
  62 }
  63
  64
  65 //
  66 // When a Connection's destructor executes, the connection must already have been
  67 // terminated. All we have to do here is clean up a bit.
  68 //
  69 Connection::~Connection()
  70 {
  71         secdebug("SS", "Connection %p destroyed", this);
  72         assert(!agentWait);
  73 }
  74
  75
  76 //
  77 // Terminate a Connection normally.
  78 // This is assumed to be properly sequenced, so no thread races are possible.
  79 //
  80 void Connection::terminate()
  81 {
  82         // cleanly discard port rights
  83         assert(state == idle);
  84         mClientPort.modRefs(MACH_PORT_RIGHT_SEND, -1);  // discard surplus send right
  85         assert(mClientPort.getRefs(MACH_PORT_RIGHT_SEND) == 1); // one left for final reply
  86         secdebug("SS", "Connection %p terminated", this);
  87 }
  88
  89
  90 //
  91 // Abort a Connection.
  92 // This may be called from thread A while thread B is working a request for the Connection,
  93 // so we must be careful.
  94 //
  95 void Connection::abort(bool keepReplyPort)
  96 {
  97         StLock<Mutex> _(*this);
  98     if (!keepReplyPort)
  99         mClientPort.destroy();          // dead as a doornail already
 100         switch (state) {
 101         case idle:
 102                 secdebug("SS", "Connection %p aborted", this);
 103                 break;
 104         case busy:
 105                 state = dying;                          // shoot me soon, please
 106                 if (agentWait)
 107                         agentWait->destroy();
 108                 secdebug("SS", "Connection %p abort deferred (busy)", this);
 109                 break;
 110         default:
 111                 assert(false);                          // impossible (we hope)
 112                 break;
 113         }
 114 }
 115
 116
 117 //
 118 // Service request framing.
 119 // These are here so "hanging" connection service threads don't fall
 120 // into the Big Bad Void as Connections and processes drop out from
 121 // under them.
 122 //
 123 void Connection::beginWork()
 124 {
 125         switch (state) {
 126         case idle:
 127                 state = busy;
 128                 break;
 129         case busy:
 130                 secdebug("SS", "Attempt to re-enter connection %p(port %d)", this, mClientPort.port());
 131                 CssmError::throwMe(CSSM_ERRCODE_INTERNAL_ERROR);        //@@@ some state-error code instead?
 132         default:
 133                 assert(false);
 134         }
 135 }
 136
 137 void Connection::checkWork()
 138 {
 139         StLock<Mutex> _(*this);
 140         switch (state) {
 141         case busy:
 142                 return;
 143         case dying:
 144                 agentWait = NULL;       // obviously we're not waiting on this
 145                 throw this;
 146         default:
 147                 assert(false);
 148         }
 149 }
 150
 151 void Connection::endWork()
 152 {
 153         switch (state) {
 154         case busy:
 155                 // process the n-step aclUpdateTrigger
 156                 if (aclUpdateTrigger) {
 157             if (--aclUpdateTriggerCount == 0) {
 158                 aclUpdateTrigger = NULL;
 159                 secdebug("kcacl", "acl update trigger expires");
 160             } else
 161                 secdebug("kcacl", "acl update trigger armed for %d calls",
 162                     aclUpdateTriggerCount);
 163         }
 164                 // end involvement
 165                 state = idle;
 166                 return;
 167         case dying:
 168                 secdebug("SS", "Connection %p abort resuming", this);
 169                 return;
 170         default:
 171                 assert(false);
 172                 return; // placebo
 173         }
 174 }