securityd/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     secinfo("SS", "New client connection %p: %d %d", this, rPort.port(), proc.uid());
  60 }
  61
  62
  63 //
  64 // When a Connection's destructor executes, the connection must already have been
  65 // terminated. All we have to do here is clean up a bit.
  66 //
  67 Connection::~Connection()
  68 {
  69     secinfo("SS", "releasing client connection %p", this);
  70         assert(!agentWait);
  71 }
  72
  73
  74 //
  75 // Set the (last known) guest handle for this connection.
  76 //
  77 void Connection::guestRef(SecGuestRef newGuest, SecCSFlags flags)
  78 {
  79         secinfo("SS", "Connection %p switches to guest 0x%x", this, newGuest);
  80         mGuestRef = newGuest;
  81 }
  82
  83
  84 //
  85 // Terminate a Connection normally.
  86 // This is assumed to be properly sequenced, so no thread races are possible.
  87 //
  88 void Connection::terminate()
  89 {
  90         // cleanly discard port rights
  91         assert(state == idle);
  92         mClientPort.modRefs(MACH_PORT_RIGHT_SEND, -1);  // discard surplus send right
  93         assert(mClientPort.getRefs(MACH_PORT_RIGHT_SEND) == 1); // one left for final reply
  94         secinfo("SS", "Connection %p terminated", this);
  95 }
  96
  97
  98 //
  99 // Abort a Connection.
 100 // This may be called from thread A while thread B is working a request for the Connection,
 101 // so we must be careful.
 102 //
 103 void Connection::abort(bool keepReplyPort)
 104 {
 105         StLock<Mutex> _(*this);
 106     if (!keepReplyPort)
 107         mClientPort.destroy();          // dead as a doornail already
 108         switch (state) {
 109         case idle:
 110                 secinfo("SS", "Connection %p aborted", this);
 111                 break;
 112         case busy:
 113                 state = dying;                          // shoot me soon, please
 114                 secinfo("SS", "Connection %p abort deferred (busy)", this);
 115                 break;
 116         default:
 117                 assert(false);                          // impossible (we hope)
 118                 break;
 119         }
 120 }
 121
 122
 123 //
 124 // Service request framing.
 125 // These are here so "hanging" connection service threads don't fall
 126 // into the Big Bad Void as Connections and processes drop out from
 127 // under them.
 128 //
 129 void Connection::beginWork(audit_token_t &auditToken)
 130 {
 131     // assume the audit token will be valid for the Connection's lifetime
 132     // (but no longer)
 133     mAuditToken = &auditToken;
 134         switch (state) {
 135         case idle:
 136                 state = busy;
 137                 mOverrideReturn = CSSM_OK;      // clear override
 138                 break;
 139         case busy:
 140                 secinfo("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     mAuditToken = NULL;
 164
 165         switch (state) {
 166         case busy:
 167                 if (mOverrideReturn && rcode == CSSM_OK)
 168                         rcode = mOverrideReturn;
 169                 state = idle;
 170                 return;
 171         case dying:
 172                 secinfo("SS", "Connection %p abort resuming", this);
 173                 return;
 174         default:
 175                 assert(false);
 176                 return; // placebo
 177         }
 178 }