[apple/security.git] / securityd / src / server.cpp

/*
 * Copyright (c) 2000-2010,2013 Apple Inc. All Rights Reserved.
 * 
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */


//
// server - securityd main server object
//
#include <securityd_client/ucsp.h>      // MIG ucsp service
#include "self.h"                                       // MIG self service
#include <security_utilities/logging.h>
#include <security_cdsa_client/mdsclient.h>
#include "server.h"
#include "session.h"
#include "acls.h"
#include "notifications.h"
#include "child.h"
#include <mach/mach_error.h>
#include <security_utilities/ccaudit.h>
#include <security_utilities/casts.h>
#include "pcscmonitor.h"

#include "agentquery.h"


using namespace MachPlusPlus;

//
// Construct the server object
//
Server::Server(CodeSignatures &signatures, const char *bootstrapName)
  : MachServer(bootstrapName),
    mBootstrapName(bootstrapName),
    mCSPModule(gGuidAppleCSP, mCssm), mCSP(mCSPModule),
        mCodeSignatures(signatures),
        mVerbosity(0),
        mWaitForClients(true), mShuttingDown(false)
{
        // make me eternal (in the object mesh)
        ref();

    // engage the subsidiary port handler for sleep notifications
        add(sleepWatcher);
}


//
// Clean up the server object
//
Server::~Server()
{
    //@@@ more later
}


//
// Locate a connection by reply port and make it the current connection
// of this thread. The connection will be marked busy, and can be accessed
// by calling Server::connection() [no argument] until it is released by
// calling Connection::endWork().
//
Connection &Server::connection(mach_port_t port, audit_token_t &auditToken)
{
        Server &server = active();
        StLock<Mutex> _(server);
        Connection *conn = server.mConnections.get(port, CSSM_ERRCODE_INVALID_CONTEXT_HANDLE);
        conn->process().checkSession(auditToken);
        active().mCurrentConnection() = conn;
        conn->beginWork(auditToken);
        return *conn;
}

Connection &Server::connection(bool tolerant)
{
        Connection *conn = active().mCurrentConnection();
        assert(conn);   // have to have one
        if (!tolerant)
                conn->checkWork();
        return *conn;
}

void Server::requestComplete(CSSM_RETURN &rcode)
{
        // note: there may not be an active connection if connection setup failed
        if (RefPointer<Connection> &conn = active().mCurrentConnection()) {
                conn->endWork(rcode);
                conn = NULL;
        }
        IFDUMPING("state", NodeCore::dumpAll());
}


//
// Shorthand for "current" process and session.
// This is the process and session for the current connection.
//
Process &Server::process()
{
        return connection().process();
}

Session &Server::session()
{
        return connection().process().session();
}

RefPointer<Key> Server::key(KeyHandle key)
{
        return U32HandleObject::findRef<Key>(key, CSSMERR_CSP_INVALID_KEY_REFERENCE);
}

RefPointer<Database> Server::database(DbHandle db)
{
        return find<Database>(db, CSSMERR_DL_INVALID_DB_HANDLE);
}

RefPointer<KeychainDatabase> Server::keychain(DbHandle db)
{
        return find<KeychainDatabase>(db, CSSMERR_DL_INVALID_DB_HANDLE);
}

RefPointer<Database> Server::optionalDatabase(DbHandle db, bool persistent)
{
        if (persistent && db != noDb)
                return database(db);
        else
                return &process().localStore();
}


//
// Locate an ACL bearer (database or key) by handle
// The handle might be used across IPC, so we clamp it accordingly
//
AclSource &Server::aclBearer(AclKind kind, U32HandleObject::Handle handle)
{
        AclSource &bearer = U32HandleObject::find<AclSource>(handle, CSSMERR_CSSM_INVALID_ADDIN_HANDLE);
        if (kind != bearer.acl().aclKind())
                CssmError::throwMe(CSSMERR_CSSM_INVALID_HANDLE_USAGE);
        return bearer;
}


//
// Run the server. This will not return until the server is forced to exit.
//
void Server::run()
{
        MachServer::run(0x10000,
        MACH_RCV_TRAILER_TYPE(MACH_MSG_TRAILER_FORMAT_0) |
        MACH_RCV_TRAILER_ELEMENTS(MACH_RCV_TRAILER_AUDIT));
}


//
// Handle thread overflow. MachServer will call this if it has hit its thread
// limit and yet still needs another thread.
//
void Server::threadLimitReached(UInt32 limit)
{
        Syslog::notice("securityd has reached its thread limit (%d) - service deadlock is possible",
                (uint32_t) limit);
}


//
// The primary server run-loop function.
// Invokes the MIG-generated main dispatch function (ucsp_server), as well
// as the self-send dispatch (self_server).
// For debug builds, look up request names in a MIG-generated table
// for better debug-log messages.
//
boolean_t ucsp_server(mach_msg_header_t *, mach_msg_header_t *);
boolean_t self_server(mach_msg_header_t *, mach_msg_header_t *);


boolean_t Server::handle(mach_msg_header_t *in, mach_msg_header_t *out)
{
        return ucsp_server(in, out) || self_server(in, out);
}


//
// Set up a new Connection. This establishes the environment (process et al) as needed
// and registers a properly initialized Connection object to run with.
// Type indicates how "deep" we need to initialize (new session, process, or connection).
// Everything at and below that level is constructed. This is straight-forward except
// in the case of session re-initialization (see below).
//
void Server::setupConnection(ConnectLevel type, Port replyPort, Port taskPort,
    const audit_token_t &auditToken, const ClientSetupInfo *info)
{
        Security::CommonCriteria::AuditToken audit(auditToken);
        
        // first, make or find the process based on task port
        StLock<Mutex> _(*this);
        RefPointer<Process> &proc = mProcesses[taskPort];
        if (proc && proc->session().sessionId() != audit.sessionId())
                proc->changeSession(audit.sessionId());
        if (proc && type == connectNewProcess) {
                // the client has amnesia - reset it
                assert(info);
                proc->reset(taskPort, info, audit);
                proc->changeSession(audit.sessionId());
        }
        if (!proc) {
                if (type == connectNewThread)   // client error (or attack)
                        CssmError::throwMe(CSSM_ERRCODE_INTERNAL_ERROR);
                assert(info);
                proc = new Process(taskPort, info, audit);
                notifyIfDead(taskPort);
                mPids[proc->pid()] = proc;
        }

        // now, establish a connection and register it in the server
        Connection *connection = new Connection(*proc, replyPort);
        if (mConnections.contains(replyPort))   // malicious re-entry attempt?
                CssmError::throwMe(CSSM_ERRCODE_INTERNAL_ERROR);        //@@@ error code? (client error)
        mConnections[replyPort] = connection;
        notifyIfDead(replyPort);
}


//
// Synchronously end a Connection.
// This is due to a request from the client, so no thread races are possible.
// In practice, this is optional since the DPN for the client thread reply port
// will destroy the connection anyway when the thread dies.
//
void Server::endConnection(Port replyPort)
{
        StLock<Mutex> _(*this);
        PortMap<Connection>::iterator it = mConnections.find(replyPort);
        assert(it != mConnections.end());
        it->second->terminate();
        mConnections.erase(it);
}


//
// Handling dead-port notifications.
// This receives DPNs for all kinds of ports we're interested in.
//
void Server::notifyDeadName(Port port)
{
        // We need the lock to get a proper iterator on mConnections or mProcesses,
        // but must release it before we call abort or kill, as these might take 
        // unbounded time, including calls out to token daemons etc.
        
        StLock<Mutex> serverLock(*this);
        secnotice("SSports", "port %d is dead", port.port());
    
    // is it a connection?
    PortMap<Connection>::iterator conIt = mConnections.find(port);
    if (conIt != mConnections.end()) {
        secnotice("SS", "%p dead connection %d", this, port.port());
        RefPointer<Connection> con = conIt->second;
                mConnections.erase(conIt);
        serverLock.unlock();
                con->abort();        
        return;
    }
    
    // is it a process?
    PortMap<Process>::iterator procIt = mProcesses.find(port);
    if (procIt != mProcesses.end()) {
        secnotice("SS", "%p dead process %d", this, port.port());
        RefPointer<Process> proc = procIt->second;
                mPids.erase(proc->pid());
                mProcesses.erase(procIt);
        serverLock.unlock();
                // The kill may take some time; make sure there is a spare thread around
                // to prevent deadlocks
                StLock<MachServer, &Server::busy, &Server::idle> _(*this);
                proc->kill();
        return;
    }
    
        // well, what IS IT?!
        secnotice("server", "spurious dead port notification for port %d", port.port());
}


//
// Handling no-senders notifications.
// This is currently only used for (subsidiary) service ports
//
void Server::notifyNoSenders(Port port, mach_port_mscount_t)
{
    secnotice("SS", "%p dead session %d", this, port.port());
}


//
// Handling signals.
// These are sent as Mach messages from ourselves to escape the limitations of
// the signal handler environment.
//
kern_return_t self_server_handleSignal(mach_port_t sport,
        mach_port_t taskPort, int sig)
{
    try {
        secnotice("SS", "signal handled %d", sig);
        if (taskPort != mach_task_self()) {
            Syslog::error("handleSignal: received from someone other than myself");
                        return KERN_SUCCESS;
                }
                switch (sig) {
                case SIGCHLD:
                        ServerChild::checkChildren();
                        break;
                case SIGINT:
            secnotice("SS", "shutdown due to SIGINT");
                        Syslog::notice("securityd terminated due to SIGINT");
                        _exit(0);
                case SIGTERM:
                        Server::active().beginShutdown();
                        break;
                case SIGPIPE:
                        fprintf(stderr, "securityd ignoring SIGPIPE received");
                        break;

#if defined(DEBUGDUMP)
                case SIGUSR1:
                        NodeCore::dumpAll();
                        break;
#endif //DEBUGDUMP

                case SIGUSR2:
                        {
                                extern PCSCMonitor *gPCSC;
                                gPCSC->startSoftTokens();
                                break;
                        }

                default:
                        assert(false);
        }
    } catch(...) {
                secnotice("SS", "exception handling a signal (ignored)");
        }
    mach_port_deallocate(mach_task_self(), taskPort);
    return KERN_SUCCESS;
}


kern_return_t self_server_handleSession(mach_port_t sport,
        mach_port_t taskPort, uint32_t event, uint64_t ident)
{
    try {
        if (taskPort != mach_task_self()) {
            Syslog::error("handleSession: received from someone other than myself");
                        return KERN_SUCCESS;
                }
                if (event == AUE_SESSION_END)
            Session::destroy(int_cast<uint64_t, Session::SessionId>(ident));
    } catch(...) {
                secnotice("SS", "exception handling a signal (ignored)");
        }
    mach_port_deallocate(mach_task_self(), taskPort);
    return KERN_SUCCESS;
}


//
// Notifier for system sleep events
//
void Server::SleepWatcher::systemWillSleep()
{
    secnotice("SS", "%p will sleep", this);
    Session::processSystemSleep();
        for (set<PowerWatcher *>::const_iterator it = mPowerClients.begin(); it != mPowerClients.end(); it++)
                (*it)->systemWillSleep();
}

void Server::SleepWatcher::systemIsWaking()
{
    secnotice("SS", "%p is waking", this);
        for (set<PowerWatcher *>::const_iterator it = mPowerClients.begin(); it != mPowerClients.end(); it++)
                (*it)->systemIsWaking();
}

void Server::SleepWatcher::systemWillPowerOn()
{
    secnotice("SS", "%p will power on", this);
        Server::active().longTermActivity();
        for (set<PowerWatcher *>::const_iterator it = mPowerClients.begin(); it != mPowerClients.end(); it++)
                (*it)->systemWillPowerOn();
}

void Server::SleepWatcher::add(PowerWatcher *client)
{
        assert(mPowerClients.find(client) == mPowerClients.end());
        mPowerClients.insert(client);
}

void Server::SleepWatcher::remove(PowerWatcher *client)
{
        assert(mPowerClients.find(client) != mPowerClients.end());
        mPowerClients.erase(client);
}


//
// Expose the process/pid map to the outside
//
Process *Server::findPid(pid_t pid) const
{
        PidMap::const_iterator it = mPids.find(pid);
        return (it == mPids.end()) ? NULL : it->second;
}


//
// Set delayed shutdown mode
//
void Server::waitForClients(bool waiting)
{
        mWaitForClients = waiting;
}


//
// Begin shutdown processing.
// We relinquish our primary state authority. From now on, we'll be
// kept alive (only) by our current clients.
//
static FILE *reportFile;

void Server::beginShutdown()
{
        StLock<Mutex> _(*this);
        if (!mWaitForClients) {
        secnotice("SS", "%p shutting down now", this);
                _exit(0);
        } else {
                if (!mShuttingDown) {
                        mShuttingDown = true;
            Session::invalidateAuthHosts();
            secnotice("SS", "%p beginning shutdown", this);
                        if (verbosity() >= 2) {
                                reportFile = fopen("/var/log/securityd-shutdown.log", "w");
                                shutdownSnitch();
                        }
                }
        }
}


//
// During shutdown, we report residual clients to dtrace, and allow a state dump
// for debugging.
// We don't bother locking for the shuttingDown() check; it's a latching boolean
// and we'll be good enough without a lock.
//
void Server::eventDone()
{
        if (this->shuttingDown()) {
                StLock<Mutex> lazy(*this, false);       // lazy lock acquisition
                if (verbosity() >= 2) {
                        lazy.lock();
            secnotice("SS", "shutting down with %ld processes and %ld transactions", mProcesses.size(), VProc::Transaction::debugCount());
                        shutdownSnitch();
                }
                IFDUMPING("shutdown", NodeCore::dumpAll());
        }
}


void Server::shutdownSnitch()
{
        time_t now;
        time(&now);
        fprintf(reportFile, "%.24s %d residual clients:\n",     ctime(&now), int(mPids.size()));
        for (PidMap::const_iterator it = mPids.begin(); it != mPids.end(); ++it) {
                string path = it->second->getPath();
                fprintf(reportFile, " %s (%d)\n", path.c_str(), it->first);
        }
        fprintf(reportFile, "\n");
        fflush(reportFile);
}

bool Server::inDarkWake()
{
    return IOPMIsADarkWake(IOPMConnectionGetSystemCapabilities());
}

//
// Initialize the CSSM/MDS subsystem.
// This was once done lazily on demand. These days, we are setting up the
// system MDS here, and CSSM is pretty much always needed, so this is called
// early during program startup. Do note that the server may not (yet) be running.
//
void Server::loadCssm(bool mdsIsInstalled)
{
        if (!mCssm->isActive()) {
                StLock<Mutex> _(*this);
                VProc::Transaction xact;
                if (!mCssm->isActive()) {
            if (!mdsIsInstalled) {  // non-system securityd instance should not reinitialize MDS
                secnotice("SS", "Installing MDS");
                IFDEBUG(if (geteuid() == 0))
                                MDSClient::mds().install();
            }
                        secnotice("SS", "CSSM initializing");
                        mCssm->init();
                        mCSP->attach();
                        secnotice("SS", "CSSM ready with CSP %s", mCSP->guid().toString().c_str());
                }
        }
}


//
// LongtermActivity/lock combo
//
LongtermStLock::LongtermStLock(Mutex &lck)
        : StLock<Mutex>(lck, false)     // don't take the lock yet
{
        if (lck.tryLock()) {    // uncontested
                this->mActive = true;
        } else {                                // contested - need backup thread
                Server::active().longTermActivity();
                this->lock();
        }
}