securityd-26232.tar.gz

[apple/securityd.git] / src / pcscmonitor.cpp

/*
 * Copyright (c) 2004 Apple Computer, 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@
 */


//
// pcscmonitor - use PCSC to monitor smartcard reader/card state for securityd
//
// PCSCMonitor is the "glue" between PCSC and the securityd objects representing
// smartcard-related things. Its job is to manage the daemon and translate real-world
// events (such as card and device insertions) into the securityd object web.
//
// PCSCMonitor uses multiple inheritance to the hilt. It is (among others)
//      (*) A notification listener, to listen to pcscd state notifications
//  (*) A MachServer::Timer, to handle timed actions
//  (*) A NotificationPort::Receiver, to get IOKit notifications of device insertions
//  (*) A Child, to watch and manage the pcscd process
//
#include "pcscmonitor.h"
#include <security_utilities/logging.h>
#include <IOKit/usb/IOUSBLib.h>


//
// Fixed configuration parameters
//
static const char PCSCD_EXEC_PATH[] = "/usr/sbin/pcscd";        // override with $PCSCDAEMON
static const char PCSCD_WORKING_DIR[] = "/var/run/pcscd";       // pcscd's working directory
static const Time::Interval PCSCD_IDLE_SHUTDOWN(120);           // kill daemon if no devices present


//
// Construct a PCSCMonitor.
// We strongly assume there's only one of us around here.
//
// Note that this constructor may well run before the server loop has started.
// Don't call anything here that requires an active server loop (like Server::active()).
// In fact, you should push all the hard work into a timer, so as not to hold up the
// general startup process.
//
PCSCMonitor::PCSCMonitor(Server &server, const char* pathToCache, ServiceLevel level)
        : Listener(kNotificationDomainPCSC, SecurityServer::kNotificationAllEvents),
          MachServer::Timer(true), // "heavy" timer task
          server(server),
          cache (NULL),
          cachePath (pathToCache),
          mServiceLevel(level),
          mTimerAction(&PCSCMonitor::initialSetup),
          mGoingToSleep(false)
{
        // do all the smartcard-related work once the event loop has started
        server.setTimer(this, Time::now());             // ASAP
}


//
// Poll PCSC for smartcard status.
// We are enumerating all readers on each call.
//
void PCSCMonitor::pollReaders()
{
        // open PCSC session if it's not already open
        mSession.open();

        // enumerate readers
        vector<string> names;  // will hold reader name C strings throughout
        mSession.listReaders(names);
        size_t count = names.size();
        secdebug("pcsc", "%ld reader(s) in system", count);
        
        // build the PCSC status inquiry array
        vector<PCSC::ReaderState> states(count); // reader status array (PCSC style)
        for (unsigned int n = 0; n < count; n++) {
                PCSC::ReaderState &state = states[n];
                ReaderMap::iterator it = mReaders.find(names[n]);
                if (it == mReaders.end()) { // new reader
                        state.clearPod();
                        state.name(names[n].c_str());
                        // lastKnown(PCSC_STATE_UNKNOWN)
                        // userData<Reader>() = NULL
                } else {
                        state = it->second->pcscState();
                        state.name(names[n].c_str());  // OUR pointer
                        state.lastKnown(state.state());
                        state.userData<Reader>() = it->second;
                }
        }
        
        // now ask PCSC for status changes
        mSession.statusChange(states);
#if DEBUGDUMP
        if (Debug::dumping("pcsc"))
                for (unsigned int n = 0; n < count; n++)
                        states[n].dump();
#endif

        // make a set of previously known reader objects (to catch those who disappeared)
        ReaderSet current;
        copy_second(mReaders.begin(), mReaders.end(), inserter(current, current.end()));
                
        // match state array against them
        for (unsigned int n = 0; n < count; n++) {
                PCSC::ReaderState &state = states[n];
                if (Reader *reader = state.userData<Reader>()) {
                        // if PCSC flags a change, notify the Reader
                        if (state.changed())
                                reader->update(state);
                        // accounted for this reader
                        current.erase(reader);
                } else {
                        RefPointer<Reader> newReader = new Reader(getTokenCache (), state);
                        mReaders.insert(make_pair(state.name(), newReader));
                        Syslog::notice("Token reader %s inserted into system", state.name());
                        newReader->update(state);               // initial state setup
                }
        }
        
        // now deal with vanished readers
        for (ReaderSet::iterator it = current.begin(); it != current.end(); it++) {
                secdebug("pcsc", "removing reader %s", (*it)->name().c_str());
                Syslog::notice("Token reader %s removed from system", (*it)->name().c_str());
                (*it)->kill();                                          // prepare to die
                mReaders.erase((*it)->name());          // remove from reader map
        }
}


TokenCache& PCSCMonitor::getTokenCache ()
{
        if (cache == NULL) {
                cache = new TokenCache(cachePath.c_str ());
        }
        
        return *cache;
}



void PCSCMonitor::launchPcscd()
{
        // launch pcscd
        secdebug("pcsc", "launching pcscd to handle smartcard device(s)");
        assert(Child::state() != alive);
        Child::reset();
        Child::fork();

        // if pcscd doesn't report a reader found soon, we'll kill it off
        scheduleTimer(true);
}


//
// Code to launch pcscd (run in child as a result of Child::fork())
//
void PCSCMonitor::childAction()
{
        // move aside any old play area
        const char *aside = tempnam("/tmp", "pcscd");
        if (::rename(PCSCD_WORKING_DIR, aside))
                switch (errno) {
                case ENOENT:            // no /tmp/pcsc (fine)
                        break;
                default:
                        secdebug("pcsc", "failed too move %s - errno=%d", PCSCD_WORKING_DIR, errno);
                        _exit(101);
                }
        else
                secdebug("pcsc", "old /tmp/pcsc moved to %s", aside);

        // lessen the pain for debugging
#if !defined(NDEBUG)
        freopen("/tmp/pcsc.debuglog", "a", stdout);     // shut up pcsc dumps to stdout
#endif //NDEBUG
        
        // execute the daemon
        const char *pcscdPath = PCSCD_EXEC_PATH;
        if (const char *env = getenv("PCSCDAEMON"))
                pcscdPath = env;
        secdebug("pcsc", "exec(%s,-f)", pcscdPath);
        execl(pcscdPath, pcscdPath, "-f", NULL);
}


//
// Event notifier.
// These events are sent by pcscd for our (sole) benefit.
//
void PCSCMonitor::notifyMe(SecurityServer::NotificationDomain domain,
                SecurityServer::NotificationEvent event, const CssmData &data)
{
        Server::active().longTermActivity();
        StLock<Mutex> _(*this);
        assert(mServiceLevel == externalDaemon || Child::state() == alive);
        pollReaders();
        scheduleTimer(mReaders.empty() && !mGoingToSleep);
}


//
// Power event notifications
//
void PCSCMonitor::systemWillSleep()
{
        StLock<Mutex> _(*this);
        secdebug("pcsc", "setting sleep marker (%ld readers as of now)", mReaders.size());
        mGoingToSleep = true;
        server.clearTimer(this);
}

void PCSCMonitor::systemIsWaking()
{
        StLock<Mutex> _(*this);
        secdebug("pcsc", "clearing sleep marker (%ld readers as of now)", mReaders.size());
        mGoingToSleep = false;
        scheduleTimer(mReaders.empty());
}


//
// Timer action.
//
void PCSCMonitor::action()
{
        StLock<Mutex> _(*this);
        (this->*mTimerAction)();
        mTimerAction = &PCSCMonitor::noDeviceTimeout;
}


//
// Update the timeout timer as requested (and indicated by context)
//
void PCSCMonitor::scheduleTimer(bool enable)
{
        if (Child::state() == alive)    // we ran pcscd; let's manage it
                if (enable) {
                        secdebug("pcsc", "setting idle timer for %g seconds", PCSCD_IDLE_SHUTDOWN.seconds());
                        server.setTimer(this, PCSCD_IDLE_SHUTDOWN);
                } else if (Timer::scheduled()) {
                        secdebug("pcsc", "clearing idle timer");
                        server.clearTimer(this);
                }
}


//
// Perform the initial PCSC subsystem initialization.
// This runs (shortly) after securityd is fully functional and the
// server loop has started.
//
void PCSCMonitor::initialSetup()
{
        switch (mServiceLevel) {
        case forcedOff:
                secdebug("pcsc", "smartcard operation is FORCED OFF");
                break;
        
        case forcedOn:
                secdebug("pcsc", "pcscd launch is forced on");
                launchPcscd();
                break;

        case externalDaemon:
                secdebug("pcsc", "using external pcscd (if any); no launch operations");
                break;
        
        default:
                secdebug("pcsc", "setting up automatic PCSC management in %s mode",
                        mServiceLevel == conservative ? "conservative" : "aggressive");

                // receive Mach-based IOKit notifications through mIOKitNotifier
                server.add(mIOKitNotifier);
                
                // receive power event notifications (through our IOPowerWatcher personality)
                server.add(this);
        
                // ask for IOKit notifications for all new USB devices and process present ones
                IOKit::DeviceMatch usbSelector(kIOUSBInterfaceClassName);
                IOKit::DeviceMatch pcCardSelector("IOPCCard16Device");
                mIOKitNotifier.add(usbSelector, *this); // this will scan existing USB devices
                mIOKitNotifier.add(pcCardSelector, *this);      // ditto for PC Card devices
                if (mServiceLevel == aggressive) {
                        // catch custom non-composite USB devices - they don't have IOServices attached
                        IOKit::DeviceMatch customUsbSelector(::IOServiceMatching("IOUSBDevice"));
                        mIOKitNotifier.add(customUsbSelector, *this);   // ditto for custom USB devices
                }
                break;
        }
        
        // we are NOT scanning for PCSC devices here. Pcscd will send us a notification when it's up
}


//
// This function is called (as a timer function) when there haven't been any (recognized)
// smartcard devicees in the system for a while.
//
void PCSCMonitor::noDeviceTimeout()
{
        secdebug("pcsc", "killing pcscd (no smartcard devices present for %g seconds)",
                PCSCD_IDLE_SHUTDOWN.seconds());
        assert(mReaders.empty());
        Child::kill(SIGTERM);
}


//
// IOKit device event notification.
// Here we listen for newly inserted devices and check whether to launch pcscd.
//
void PCSCMonitor::ioChange(IOKit::DeviceIterator &iterator)
{
        assert(mServiceLevel != externalDaemon && mServiceLevel != forcedOff);
        if (Child::state() == alive) {
                secdebug("pcsc", "pcscd is alive; ignoring device insertion(s)");
                return;
        }
        secdebug("pcsc", "processing device insertion notices");
        while (IOKit::Device dev = iterator()) {
                bool launch = false;
                switch (deviceSupport(dev)) {
                case definite:
                        launch = true;
                        break;
                case possible:
                        launch = (mServiceLevel == aggressive);
                        break;
                case impossible:
                        break;
                }
                if (launch) {
                        launchPcscd();
                        return;
                }
        }
        secdebug("pcsc", "no relevant devices found");
}


//
// Check an IOKit device that's just come online to see if it's
// a smartcard device of some sort.
//
PCSCMonitor::DeviceSupport PCSCMonitor::deviceSupport(const IOKit::Device &dev)
{
        try {
                secdebug("scsel", "%s", dev.path().c_str());
                if (CFRef<CFNumberRef> cfInterface = dev.property<CFNumberRef>("bInterfaceClass"))
                        switch (IFDEBUG(uint32 clas =) cfNumber(cfInterface)) {
                        case kUSBChipSmartCardInterfaceClass:           // CCID smartcard reader - go
                                secdebug("scsel", "  CCID smartcard reader recognized");
                                return definite;
                        case kUSBVendorSpecificInterfaceClass:
                                secdebug("scsel", "  Vendor-specific interface - possible match");
                                return possible;
                        default:
                                secdebug("scsel", "  interface class %ld is not a smartcard device", clas);
                                return impossible;
                        }
                if (CFRef<CFNumberRef> cfDevice = dev.property<CFNumberRef>("bDeviceClass"))
                        if (cfNumber(cfDevice) == kUSBVendorSpecificClass) {
                                secdebug("scsel", "  Vendor-specific device - possible match");
                                return possible;
                        }
                return impossible;
        } catch (...) {
                secdebug("scsel", "  exception while examining device - ignoring it");
                return impossible;
        }
}


//
// This gets called (by the Unix/Child system) when pcscd has died for any reason
//
void PCSCMonitor::dying()
{
        Server::active().longTermActivity();
        StLock<Mutex> _(*this);
        assert(Child::state() == dead);
        if (!mReaders.empty()) {
                // uh-oh. We had readers connected when pcscd suddenly left
                secdebug("pcsc", "%ld readers were present when pcscd died", mReaders.size());
                for (ReaderMap::const_iterator it = mReaders.begin(); it != mReaders.end(); it++) {
                        Reader *reader = it->second;
                        secdebug("pcsc", "removing reader %s", reader->name().c_str());
                        reader->kill();                                         // prepare to die
                }
                mReaders.erase(mReaders.begin(), mReaders.end());
                secdebug("pcsc", "orphaned readers cleared");
        }
        //@@@ this is where we would attempt a restart, if we wanted to...
}