src/connection.cpp

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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), mGuestRef(kSecNoGuest), state(idle), agentWait(NULL)
  53 {
  54         parent(proc);
  55
  56         // bump the send-rights count on the reply port so we keep the right after replying
  57         mClientPort.modRefs(MACH_PORT_RIGHT_SEND, +1);
  58
  59         secdebug("SS", "New connection %p for process %d clientport=%d",
  60                 this, process().pid(), int(rPort));
  61 }
  62
  63
  64 //
  65 // When a Connection's destructor executes, the connection must already have been
  66 // terminated. All we have to do here is clean up a bit.
  67 //
  68 Connection::~Connection()
  69 {
  70         secdebug("SS", "Connection %p destroyed", this);
  71         assert(!agentWait);
  72 }
  73
  74
  75 //
  76 // Set the (last known) guest handle for this connection.
  77 //
  78 void Connection::guestRef(SecGuestRef newGuest, SecCSFlags flags)
  79 {
  80         secdebug("SS", "Connection %p switches to guest 0x%x", this, newGuest);
  81         mGuestRef = newGuest;
  82 }
  83
  84
  85 //
  86 // Terminate a Connection normally.
  87 // This is assumed to be properly sequenced, so no thread races are possible.
  88 //
  89 void Connection::terminate()
  90 {
  91         // cleanly discard port rights
  92         assert(state == idle);
  93         mClientPort.modRefs(MACH_PORT_RIGHT_SEND, -1);  // discard surplus send right
  94         assert(mClientPort.getRefs(MACH_PORT_RIGHT_SEND) == 1); // one left for final reply
  95         secdebug("SS", "Connection %p terminated", this);
  96 }
  97
  98
  99 //
 100 // Abort a Connection.
 101 // This may be called from thread A while thread B is working a request for the Connection,
 102 // so we must be careful.
 103 //
 104 void Connection::abort(bool keepReplyPort)
 105 {
 106         StLock<Mutex> _(*this);
 107     if (!keepReplyPort)
 108         mClientPort.destroy();          // dead as a doornail already
 109         switch (state) {
 110         case idle:
 111                 secdebug("SS", "Connection %p aborted", this);
 112                 break;
 113         case busy:
 114                 state = dying;                          // shoot me soon, please
 115                 if (agentWait)
 116                         agentWait->destroy();
 117                 secdebug("SS", "Connection %p abort deferred (busy)", this);
 118                 break;
 119         default:
 120                 assert(false);                          // impossible (we hope)
 121                 break;
 122         }
 123 }
 124
 125
 126 //
 127 // Service request framing.
 128 // These are here so "hanging" connection service threads don't fall
 129 // into the Big Bad Void as Connections and processes drop out from
 130 // under them.
 131 //
 132 void Connection::beginWork()
 133 {
 134         switch (state) {
 135         case idle:
 136                 state = busy;
 137                 mOverrideReturn = CSSM_OK;      // clear override
 138                 break;
 139         case busy:
 140                 secdebug("SS", "Attempt to re-enter connection %p(port %d)", this, mClientPort.port());
 141                 CssmError::throwMe(CSSM_ERRCODE_INTERNAL_ERROR);        //@@@ some state-error code instead?
 142         default:
 143                 assert(false);
 144         }
 145 }
 146
 147 void Connection::checkWork()
 148 {
 149         StLock<Mutex> _(*this);
 150         switch (state) {
 151         case busy:
 152                 return;
 153         case dying:
 154                 agentWait = NULL;       // obviously we're not waiting on this
 155                 throw this;
 156         default:
 157                 assert(false);
 158         }
 159 }
 160
 161 void Connection::endWork(CSSM_RETURN &rcode)
 162 {
 163         switch (state) {
 164         case busy:
 165                 if (mOverrideReturn && rcode == CSSM_OK)
 166                         rcode = mOverrideReturn;
 167                 state = idle;
 168                 return;
 169         case dying:
 170                 secdebug("SS", "Connection %p abort resuming", this);
 171                 return;
 172         default:
 173                 assert(false);
 174                 return; // placebo
 175         }
 176 }