Big-Data-HPC-Platform/common/remote/sockfile.cpp

/*##############################################################################

    Copyright (C) 2011 HPCC Systems.

    All rights reserved. This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as
    published by the Free Software Foundation, either version 3 of the
    License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
############################################################################## */

// todo look at IRemoteFileServer stop


#include "platform.h"
#include "limits.h"

#include "jlib.hpp"
#include "jio.hpp"

#include "jmutex.hpp"
#include "jfile.hpp"
#include "jmisc.hpp"
#include "jthread.hpp"

#include "sockfile.hpp"
#include "portlist.h"
#include "jsocket.hpp"
#include "jencrypt.hpp"
#include "jset.hpp"

#include "remoteerr.hpp"

#define SOCKET_CACHE_MAX 500

#define MAX_THREADS             100
#define TARGET_MIN_THREADS      20
#define TARGET_ACTIVE_THREADS   80

#ifdef _DEBUG
//#define SIMULATE_PACKETLOSS 1
#endif

#define TREECOPYTIMEOUT   (60*60*1000)     // 1Hr (I guess could take longer for big file but at least will stagger)
#define TREECOPYPOLLTIME  (60*1000*5)      // for tracing that delayed
#define TREECOPYPRUNETIME (24*60*60*1000)  // 1 day

#if SIMULATE_PACKETLOSS

#define TESTING_FAILURE_RATE_LOST_SEND  10 // per 1000
#define TESTING_FAILURE_RATE_LOST_RECV  10 // per 1000
#define DUMMY_TIMEOUT_MAX (1000*10)

static bool errorSimulationOn = true;
static ISocket *timeoutreadsock = NULL; // used to trigger 


struct dummyReadWrite
{
    class X
    {
        dummyReadWrite *parent;
    public:
        X(dummyReadWrite *_parent)
        {
            parent = _parent;
        }
        ~X()
        {
            delete parent;
        }
    };

    class TimeoutSocketException: public CInterface, public IJSOCK_Exception
    {
    public:
        IMPLEMENT_IINTERFACE;

        TimeoutSocketException()
        {
        }

        virtual ~TimeoutSocketException()
        {
        }

        int errorCode() const { return JSOCKERR_timeout_expired; }
        StringBuffer &  errorMessage(StringBuffer &str) const
        {
            return str.append("timeout expired");
        }
        MessageAudience errorAudience() const 
        { 
            return MSGAUD_user; 
        }
    };


    ISocket *sock;

    dummyReadWrite(ISocket *_sock)
    {
        sock = _sock;
    }

    void readtms(void* buf, size32_t min_size, size32_t max_size, size32_t &size_read, time_t timeout)
    {
        X x(this);
        unsigned t = msTick();
        unsigned r = getRandom();
        bool timeoutread = (timeoutreadsock==sock);
        timeoutreadsock=NULL;
        if (!timeoutread)
            sock->readtms(buf, min_size, max_size, size_read, timeout);
        if (timeoutread||(errorSimulationOn&&(TESTING_FAILURE_RATE_LOST_RECV>0)&&(r%1000<TESTING_FAILURE_RATE_LOST_RECV))) {
            PrintStackReport();
            if (timeoutread)
                PROGLOG("** Simulate timeout");
            else
                PROGLOG("** Simulate Packet loss (size %d,%d)",min_size,max_size);
            if (timeout>DUMMY_TIMEOUT_MAX)
                timeout = DUMMY_TIMEOUT_MAX;
            t = msTick()-t;
            if (t<timeout)
                Sleep(timeout-t);
            IJSOCK_Exception *e = new TimeoutSocketException;
            throw e;
        }
    }
    size32_t write(void const* buf, size32_t size)
    {
        X x(this);
        timeoutreadsock=NULL;
        unsigned r = getRandom();
        if (errorSimulationOn&&(TESTING_FAILURE_RATE_LOST_SEND>0)&&(r%1000<TESTING_FAILURE_RATE_LOST_SEND)) {
            PrintStackReport();
            PROGLOG("** Simulate Packet loss (size %d)",size);
            timeoutreadsock=sock;
            return size; 
        }
        return sock->write(buf,size);
    }
};



#define SOCKWRITE(sock) (new dummyReadWrite(sock))->write
#define SOCKREADTMS(sock) (new dummyReadWrite(sock))->readtms
#else
#define SOCKWRITE(sock) sock->write
#define SOCKREADTMS(sock) sock->readtms
#endif

// backward compatible modes
typedef enum { compatIFSHnone, compatIFSHread, compatIFSHwrite, compatIFSHexec, compatIFSHall} compatIFSHmode;

static const char *VERSTRING= "DS V1.7e - 7 "       // dont forget FILESRV_VERSION in header
#ifdef _WIN32
"Windows ";
#else
"Linux ";
#endif

typedef unsigned char RemoteFileCommandType;
typedef int RemoteFileIOHandle;

static unsigned maxConnectTime = 0;
static unsigned maxReceiveTime = 0;

void clientSetRemoteFileTimeouts(unsigned maxconnecttime,unsigned maxreadtime)
{
    maxConnectTime = maxconnecttime;
    maxReceiveTime = maxreadtime;
}


struct sRFTM        
{
    CTimeMon *timemon;
    sRFTM() {  timemon = maxReceiveTime?new CTimeMon(maxReceiveTime):NULL; }
    ~sRFTM() { delete timemon; }
};


const char *remoteServerVersionString() { return VERSTRING; }

static bool AuthenticationEnabled = true;

bool enableDafsAuthentication(bool on)
{
    bool ret = AuthenticationEnabled;
    AuthenticationEnabled = on;
    return ret;
}


#define CLIENT_TIMEOUT      (1000*60*60*12)     // long timeout in case zombies
#define SERVER_TIMEOUT      (1000*60*5)         // timeout when waiting for dafilesrv to reply after command
                                                // (increased when waiting for large block)
#define DAFS_CONNECT_FAIL_RETRY_TIME (1000*60*15)
#ifdef SIMULATE_PACKETLOSS
#define NORMAL_RETRIES      (1)
#define LENGTHY_RETRIES     (1)
#else
#define NORMAL_RETRIES      (3)
#define LENGTHY_RETRIES     (12)
#endif

#ifdef _DEBUG
static byte traceFlags=0x30;
#else
static byte traceFlags=0x20;
#endif

#define TF_TRACE (traceFlags&1)
#define TF_TRACE_PRE_IO (traceFlags&2)
#define TF_TRACE_FULL (traceFlags&4)
#define TF_TRACE_CLIENT_CONN (traceFlags&8)
#define TF_TRACE_TREE_COPY (traceFlags&0x10)
#define TF_TRACE_CLIENT_STATS (traceFlags&0x20)



enum {
    RFCopenIO,                                      // 0
    RFCcloseIO,             
    RFCread,
    RFCwrite,
    RFCsize,
    RFCexists,
    RFCremove,
    RFCrename,
    RFCgetver,
    RFCisfile,
    RFCisdirectory,                                 // 10
    RFCisreadonly,
    RFCsetreadonly,
    RFCgettime,
    RFCsettime,
    RFCcreatedir,
    RFCgetdir,
    RFCstop,
    RFCexec,
    RFCkill,
    RFCredeploy,                                    // 20
    RFCgetcrc,
    RFCmove,
// 1.5 features below
    RFCsetsize,
    RFCextractblobelements,
    RFCcopy,
    RFCappend,
    RFCmonitordir,
    RFCsettrace,
    RFCgetinfo,
    RFCfirewall,    // not used currently          // 30
    RFCunlock,  
    RFCunlockreply,
    RFCinvalid,
    RFCcopysection,
// 1.7e
    RFCtreecopy,
// 1.7e - 1
    RFCtreecopytmp,
    RFCmax,
    };


typedef enum { ACScontinue, ACSdone, ACSerror} AsyncCommandStatus;



typedef byte OnceKey[16];

static void genOnce(OnceKey &key)
{
    static __int64 inc=0;
    *(unsigned *)&key[0] = getRandom();
    *(__int64 *)&key[4] = ++inc;
    *(unsigned *)&key[12] = getRandom();
}

static void mergeOnce(OnceKey &key,size32_t sz,const void *data)
{
    assertex(sz<=sizeof(OnceKey));
    const byte *p = (const byte *)data;
    while (sz)
        key[--sz] ^= *(p++);
}

//---------------------------------------------------------------------------

class CThrottler
{
    Semaphore &sem;
    bool got;
public:
    CThrottler(Semaphore &_sem) : sem(_sem), got(false)
    {
        take();
    }
    ~CThrottler()
    {
        release();
    }
    bool take()
    {
        assertex(!got);
        got = false;
        loop {
            if (sem.wait(5000)) {
                got = true;
                break;
            }
            unsigned cpu = getLatestCPUUsage();
            PROGLOG("Throttler stalled (%d%% cpu)",cpu);
            if (getLatestCPUUsage()<75) 
                break;
        }
        return got;
    }
    bool release()
    {
        if (got)
        {
            got = false;
            sem.signal();
            return true;
        }
        return false;
    }
};

// temporarily release a throttler slot
class CThrottleReleaseBlock
{
    CThrottler &throttler;
    bool had;
public:
    CThrottleReleaseBlock(CThrottler &_throttler) : throttler(_throttler)
    {
        had = throttler.release();
    }
    ~CThrottleReleaseBlock()
    {
        if (had)
            throttler.take();
    }
};

//---------------------------------------------------------------------------

class CDafsException: public CInterface, public IDAFS_Exception
{
    StringAttr msg;
    int     errcode;
public:
    IMPLEMENT_IINTERFACE;

    CDafsException(int code,const char *_msg) 
        : errcode(code), msg(_msg)
    {
    };

    int errorCode() const 
    { 
        return errcode; 
    }

    StringBuffer &  errorMessage(StringBuffer &str) const
    { 
        return str.append(msg);
    }
    MessageAudience errorAudience() const 
    { 
        return MSGAUD_user; 
    }
};

static IDAFS_Exception *createDafsException(int code,const char *msg)
{
    return new CDafsException(code,msg);
}

void setDafsEndpointPort(SocketEndpoint &ep)
{
    // odd kludge (don't do this at home)
    byte ipb[4];
    if (ep.getNetAddress(sizeof(ipb),&ipb)==sizeof(ipb)) {
        if ((ipb[0]==255)&&(ipb[1]==255)) {
            ep.port = (((unsigned)ipb[2])<<8)+ipb[3];
            ep.ipset(queryLocalIP());
        }
    }
    if (ep.port==0)
        ep.port = DAFILESRV_PORT;
}


inline MemoryBuffer & initSendBuffer(MemoryBuffer & buff)
{
    buff.setEndian(__BIG_ENDIAN);       // transfer as big endian...
    buff.append((unsigned)0);           // reserve space for length prefix
    return buff;
}

inline void sendBuffer(ISocket * socket, MemoryBuffer & src)
{
    unsigned length = src.length() - sizeof(unsigned);
    byte * buffer = (byte *)src.toByteArray();
    if (TF_TRACE_FULL)
        PROGLOG("sendBuffer size %d, data = %d %d %d %d",length, (int)buffer[4],(int)buffer[5],(int)buffer[6],(int)buffer[7]);
    _WINCPYREV(buffer, &length, sizeof(unsigned));
    SOCKWRITE(socket)(buffer, src.length());
}

inline size32_t receiveBufferSize(ISocket * socket, unsigned numtries=NORMAL_RETRIES,CTimeMon *timemon=NULL)
{
    unsigned timeout = SERVER_TIMEOUT;
    if (numtries==0) {
        numtries = 1;
        timeout = 10*1000;  // 10s
    }
    while (numtries--) {
        try {
            if (timemon) {
                unsigned remaining;
                if (timemon->timedout(&remaining)||(remaining<10))
                    remaining = 10;
                if (remaining<timeout)
                    timeout = remaining;
            }
            size32_t szread;
            size32_t gotLength;
            SOCKREADTMS(socket)(&gotLength, sizeof(gotLength), sizeof(gotLength), szread, timeout);
            _WINREV(gotLength);
            if (TF_TRACE_FULL)
                PROGLOG("receiveBufferSized %d",gotLength);
            return gotLength;
        }
        catch (IJSOCK_Exception *e) {
            if ((numtries==0)||(e->errorCode()!=JSOCKERR_timeout_expired)||(timemon&&timemon->timedout())) {
                throw;
            }
            StringBuffer err;
            char peername[256];
            socket->peer_name(peername,sizeof(peername)-1);
            WARNLOG("Remote connection %s: %s",peername,e->errorMessage(err).str()); // why no peername
            e->Release();
            Sleep(500+getRandom()%1000); // ~1s
        }
    }
    return 0;
}

static void flush(ISocket *socket)
{
    MemoryBuffer sendbuf;
    initSendBuffer(sendbuf);
    sendbuf.append((RemoteFileCommandType)RFCgetver);
    sendbuf.append((unsigned)RFCgetver);
    MemoryBuffer reply;
    size32_t totread=0;
    try {
        sendBuffer(socket, sendbuf);
        char buf[1024];
        loop {
            Sleep(1000);    // breathe
            size32_t szread;
            SOCKREADTMS(socket)(buf, 1, sizeof(buf), szread, 1000*60);
            totread += szread;
        }
    }
    catch (IJSOCK_Exception *e) {
        if (totread)
            PROGLOG("%d bytes discarded",totread);
        if (e->errorCode()!=JSOCKERR_timeout_expired)
            EXCLOG(e,"flush");
        e->Release();
    }
}

inline void receiveBuffer(ISocket * socket, MemoryBuffer & tgt, unsigned numtries=1, size32_t maxsz=0x7fffffff)
    // maxsz is a guess at a resonable upper max to catch where protocol error
{
    sRFTM tm;
    size32_t gotLength = receiveBufferSize(socket, numtries,tm.timemon);
    if (gotLength) {
        size32_t origlen = tgt.length();
        try {
            if (gotLength>maxsz) {
                StringBuffer msg;
                msg.appendf("receiveBuffer maximum block size exceeded %d/%d",gotLength,maxsz);
                PrintStackReport();
                throw createDafsException(DAFSERR_protocol_failure,msg.str());
            }
            unsigned timeout = SERVER_TIMEOUT*(numtries?numtries:1);
            if (tm.timemon) {
                unsigned remaining;
                if (tm.timemon->timedout(&remaining)||(remaining<10))
                    remaining = 10;
                if (remaining<timeout)
                    timeout = remaining;
            }
            size32_t szread;
            SOCKREADTMS(socket)((gotLength<4000)?tgt.reserve(gotLength):tgt.reserveTruncate(gotLength), gotLength, gotLength, szread, timeout);
        }
        catch (IJSOCK_Exception *e) {
            if (e->errorCode()!=JSOCKERR_timeout_expired) {
                EXCLOG(e,"receiveBuffer(1)");
                PrintStackReport();
                if (!tm.timemon||!tm.timemon->timedout())
                    flush(socket);
            }
            else {
                EXCLOG(e,"receiveBuffer");
                PrintStackReport();
            }
            tgt.setLength(origlen);
            throw;
        }
        catch (IException *e) {
            EXCLOG(e,"receiveBuffer(2)");
            PrintStackReport();
            if (!tm.timemon||!tm.timemon->timedout())
                flush(socket);
            tgt.setLength(origlen);
            throw;
        }

    }
    tgt.setEndian(__BIG_ENDIAN);
}


struct CConnectionRec
{
    SocketEndpoint ep;
    unsigned tick;
    IArrayOf<ISocket> socks;            // relies on isShared
};

//---------------------------------------------------------------------------
// Local mount redirect

struct CLocalMountRec: public CInterface
{
    IpAddress ip;
    StringAttr dir;             // dir path on remote ip
    StringAttr local;           // local dir path
};

static CIArrayOf<CLocalMountRec> localMounts;
static CriticalSection           localMountCrit;

void setDafsLocalMountRedirect(const IpAddress &ip,const char *dir,const char *mountdir)
{
    CriticalBlock block(localMountCrit);
    ForEachItemInRev(i,localMounts) {
        CLocalMountRec &mount = localMounts.item(i);
        if (dir==NULL) { // remove all matching mount
            if (!mountdir)
                return;
            if (strcmp(mount.local,mountdir)==0) 
                localMounts.remove(i);
        }
        else if (mount.ip.ipequals(ip)&&(strcmp(mount.dir,dir)==0)) {
            if (mountdir) {
                mount.local.set(mountdir);
                return;
            }
            else
                localMounts.remove(i);
        }
    }
    if (dir&&mountdir) {
        CLocalMountRec &mount = *new CLocalMountRec;
        mount.ip.ipset(ip);
        mount.dir.set(dir);
        mount.local.set(mountdir);
        localMounts.append(mount);
    }
}

IFile *createFileLocalMount(const IpAddress &ip, const char * filename)
{
    CriticalBlock block(localMountCrit);
    ForEachItemInRev(i,localMounts) {
        CLocalMountRec &mount = localMounts.item(i);
        if (mount.ip.ipequals(ip)) {
            size32_t bl = mount.dir.length();
            if (isPathSepChar(mount.dir[bl-1]))
                bl--;
            if ((memcmp((void *)filename,(void *)mount.dir.get(),bl)==0)&&(isPathSepChar(filename[bl])||!filename[bl])) { // match
                StringBuffer locpath(mount.local);
                if (filename[bl])
                    addPathSepChar(locpath).append(filename+bl+1);
                locpath.replace((PATHSEPCHAR=='\\')?'/':'\\',PATHSEPCHAR);
                return createIFile(locpath.str());
            }
        }
    }
    return NULL;
}


//---------------------------------------------------------------------------


static class CConnectionTable: public SuperHashTableOf<CConnectionRec,SocketEndpoint>
{

    void onAdd(void *) {}

    void onRemove(void *e)
    {
        CConnectionRec *r=(CConnectionRec *)e;      
        delete r;
    }

    unsigned getHashFromElement(const void *e) const
    {
        const CConnectionRec &elem=*(const CConnectionRec *)e;      
        return elem.ep.hash(0);
    }

    unsigned getHashFromFindParam(const void *fp) const
    {
        return ((const SocketEndpoint *)fp)->hash(0);
    }

    const void * getFindParam(const void *p) const
    {
        const CConnectionRec &elem=*(const CConnectionRec *)p;      
        return (void *)&elem.ep;
    }

    bool matchesFindParam(const void * et, const void *fp, unsigned) const
    {
        return ((CConnectionRec *)et)->ep.equals(*(SocketEndpoint *)fp);
    }

    IMPLEMENT_SUPERHASHTABLEOF_REF_FIND(CConnectionRec,SocketEndpoint);

    unsigned numsockets;

public:
    static CriticalSection crit;

    CConnectionTable() 
    {
        numsockets = 0;
    }
    ~CConnectionTable() { 
        releaseAll(); 
    }

    ISocket *lookup(const SocketEndpoint &ep)
    {
        // always called from crit block
        CConnectionRec *r = SuperHashTableOf<CConnectionRec,SocketEndpoint>::find(&ep);
        if (r) {
            ForEachItemIn(i,r->socks) {
                ISocket *s = &r->socks.item(i);
                if (!QUERYINTERFACE(s, CInterface)->IsShared()) {
                    r->tick = msTick();
                    s->Link();
                    return s;
                }
            }
        }
        return NULL;
    }

    void addLink(SocketEndpoint &ep,ISocket *sock)
    {
        // always called from crit block
        while (numsockets>=SOCKET_CACHE_MAX) {
            // find oldest 
            CConnectionRec *c = NULL;
            unsigned oldest = 0;
            CConnectionRec *old = NULL;
            unsigned oldi;
            unsigned now = msTick();
            loop {
                c = (CConnectionRec *)SuperHashTableOf<CConnectionRec,SocketEndpoint>::next(c);
                if (!c)
                    break;
                ForEachItemIn(i,c->socks) {
                    ISocket *s = &c->socks.item(i);
                    if (!QUERYINTERFACE(s, CInterface)->IsShared()) { // candidate to remove
                        unsigned t = now-c->tick;
                        if (t>oldest) {
                            oldest = t;
                            old = c;
                            oldi = i;
                        }
                    }
                }
            }
            if (!old)
                return;
            old->socks.remove(oldi);
            numsockets--;
        }
        CConnectionRec *r = SuperHashTableOf<CConnectionRec,SocketEndpoint>::find(&ep);
        if (!r) {
            r = new CConnectionRec;
            r->ep = ep;
            SuperHashTableOf<CConnectionRec,SocketEndpoint>::add(*r);
        }
        sock->Link();
        r->socks.append(*sock);
        numsockets++;
        r->tick = msTick();
    }

    void remove(SocketEndpoint &ep,ISocket *sock)
    {
        // always called from crit block
        CConnectionRec *r = SuperHashTableOf<CConnectionRec,SocketEndpoint>::find(&ep);
        if (r) 
            if (r->socks.zap(*sock)&&numsockets)
                numsockets--;

    }
    

} *ConnectionTable = NULL;


CriticalSection CConnectionTable::crit;

void clientSetDaliServixSocketCaching(bool on)
{
    CriticalBlock block(CConnectionTable::crit);
    if (on) {
        if (!ConnectionTable)
            ConnectionTable = new CConnectionTable;
    }
    else {
        delete ConnectionTable;
        ConnectionTable = NULL;
    }
}

//---------------------------------------------------------------------------

// TreeCopy

#define TREECOPY_CACHE_SIZE 50

struct CTreeCopyItem: public CInterface
{
    StringAttr net;
    StringAttr mask;
    offset_t sz;                // original size
    CDateTime dt;               // original date
    RemoteFilenameArray loc;    // locations for file - 0 is original
    Owned<IBitSet> busy;    
    unsigned lastused;

    CTreeCopyItem(RemoteFilename &orig, const char *_net, const char *_mask, offset_t _sz, CDateTime &_dt)
        : net(_net), mask(_mask)
    {
        loc.append(orig);
        dt.set(_dt);
        sz = _sz;
        busy.setown(createBitSet());
        lastused = msTick();
    }
    bool equals(const RemoteFilename &orig, const char *_net, const char *_mask, offset_t _sz, CDateTime &_dt) 
    {
        if (!orig.equals(loc.item(0)))
            return false;
        if (strcmp(_net,net)!=0)
            return false;
        if (strcmp(_mask,mask)!=0)
            return false;
        if (sz!=_sz)
            return false;
        return (dt.equals(_dt,false));
    }
};

static CIArrayOf<CTreeCopyItem>  treeCopyArray;
static CriticalSection           treeCopyCrit;
static unsigned                  treeCopyWaiting=0;
static Semaphore                 treeCopySem;   

#define DEBUGSAMEIP false

static void treeCopyFile(RemoteFilename &srcfn, RemoteFilename &dstfn, const char *net, const char *mask, IpAddress &ip, bool usetmp, CThrottler *throttler)
{
    unsigned start = msTick();
    Owned<IFile> dstfile = createIFile(dstfn);
    // the following is really to check the dest node is up and working (otherwise not much point in continuing!)
    if (dstfile->exists())
        PROGLOG("TREECOPY overwriting '%s'",dstfile->queryFilename());
    Owned<IFile> srcfile = createIFile(srcfn);
    unsigned lastmin = 0;
    if (!srcfn.queryIP().ipequals(dstfn.queryIP())) {
        CriticalBlock block(treeCopyCrit);
        loop {
            CDateTime dt;
            offset_t sz;
            try {
                sz = srcfile->size();
                if (sz==(offset_t)-1) {
                    if (TF_TRACE_TREE_COPY)
                        PROGLOG("TREECOPY source not found '%s'",srcfile->queryFilename());
                    break;
                }
                srcfile->getTime(NULL,&dt,NULL);
            }
            catch (IException *e) {
                EXCLOG(e,"treeCopyFile(1)");
                e->Release();
                break;
            }
            Linked<CTreeCopyItem> tc;
            unsigned now = msTick();
            ForEachItemInRev(i1,treeCopyArray) {
                CTreeCopyItem &item = treeCopyArray.item(i1);
                // prune old entries (not strictly needed buf I think better)
                if (now-item.lastused>TREECOPYPRUNETIME) 
                    treeCopyArray.remove(i1);
                else if (!tc.get()&&item.equals(srcfn,net,mask,sz,dt)) {
                    tc.set(&item);
                    item.lastused = now;
                }
            }
            if (!tc.get()) {
                if (treeCopyArray.ordinality()>=TREECOPY_CACHE_SIZE)
                    treeCopyArray.remove(0);
                tc.setown(new CTreeCopyItem(srcfn,net,mask,sz,dt));
                treeCopyArray.append(*tc.getLink());
            }
            ForEachItemInRev(cand,tc->loc) { // rev to choose copied locations first (maybe optional?)
                if (!tc->busy->testSet(cand)) {
                    // check file accessible and matches
                    if (!cand&&dstfn.equals(tc->loc.item(cand)))  // hmm trying to overwrite existing, better humor
                        continue;
                    bool ok = true;
                    Owned<IFile> rmtfile = createIFile(tc->loc.item(cand));
                    if (cand) { // only need to check if remote
                        try {
                            if (rmtfile->size()!=sz)
                                ok = false;
                            else {
                                CDateTime fdt;
                                rmtfile->getTime(NULL,&fdt,NULL);
                                ok = fdt.equals(dt);
                            }
                        }
                        catch (IException *e) {
                            EXCLOG(e,"treeCopyFile(2)");
                            e->Release();
                            ok = false;
                        }
                    }
                    if (ok) { // if not ok leave 'busy'
                        // finally lets try and copy!
                        try {
                            if (TF_TRACE_TREE_COPY)
                                PROGLOG("TREECOPY(started) %s to %s",rmtfile->queryFilename(),dstfile->queryFilename());
                            {
                                CriticalUnblock unblock(treeCopyCrit); // note we have tc linked
                                rmtfile->copyTo(dstfile,0x100000,NULL,usetmp);
                            }
                            if (TF_TRACE_TREE_COPY)
                                PROGLOG("TREECOPY(done) %s to %s",rmtfile->queryFilename(),dstfile->queryFilename());
                            tc->busy->set(cand,false); 
                            if (treeCopyWaiting)
                                treeCopySem.signal((treeCopyWaiting>1)?2:1); 
                            // add to known locations
                            tc->busy->set(tc->loc.ordinality(),false); // prob already is clear
                            tc->loc.append(dstfn);
                            ip.ipset(tc->loc.item(cand).queryIP());
                            return;
                        }
                        catch (IException *e) {
                            if (cand==0) {
                                tc->busy->set(0,false); // don't leave busy 
                                if (treeCopyWaiting)
                                    treeCopySem.signal();
                                throw;      // what more can we do!
                            }
                            EXCLOG(e,"treeCopyFile(3)");
                            e->Release();
                        }
                    }
                }
            }
            // all locations busy
            if (msTick()-start>TREECOPYTIMEOUT) {
                WARNLOG("Treecopy %s wait timed out", srcfile->queryFilename());
                break;
            }
            treeCopyWaiting++; // note this isn't precise - just indication
            {
                CriticalUnblock unblock(treeCopyCrit);
                if (throttler)
                {
                    CThrottleReleaseBlock block(*throttler);
                    treeCopySem.wait(TREECOPYPOLLTIME);
                }
                else
                    treeCopySem.wait(TREECOPYPOLLTIME);
            }
            treeCopyWaiting--;
            if ((msTick()-start)/10*1000!=lastmin) {
                lastmin = (msTick()-start)/10*1000;
                PROGLOG("treeCopyFile delayed: %s to %s",srcfile->queryFilename(),dstfile->queryFilename());
            }
        }
    }
    else if (TF_TRACE_TREE_COPY)
        PROGLOG("TREECOPY source on same node as destination");
    if (TF_TRACE_TREE_COPY)
        PROGLOG("TREECOPY(started,fallback) %s to %s",srcfile->queryFilename(),dstfile->queryFilename());
    try {
        GetHostIp(ip);
        srcfile->copyTo(dstfile,0x100000,NULL,usetmp);
    }
    catch (IException *e) {
        EXCLOG(e,"TREECOPY(done,fallback)");
        throw;
    }
    if (TF_TRACE_TREE_COPY)
        PROGLOG("TREECOPY(done,fallback) %s to %s",srcfile->queryFilename(),dstfile->queryFilename());
}



//---------------------------------------------------------------------------

class CRemoteBase: public CInterface
{

    Owned<ISocket>          socket;
    static  SocketEndpoint  lastfailep;
    static unsigned         lastfailtime;

    void connectSocket(SocketEndpoint &ep)
    {
        sRFTM tm;
        // called in CConnectionTable::crit
        unsigned retries = 3;
        if (ep.equals(lastfailep)) {
            if (msTick()-lastfailtime<DAFS_CONNECT_FAIL_RETRY_TIME) {
                StringBuffer msg("Failed to connect to dafilesrv/daliservix on ");
                ep.getUrlStr(msg);
                throw createDafsException(DAFSERR_connection_failed,msg.str());
            }
            lastfailep.set(NULL);
            retries = 1;    // on probation
        }
        while(retries--) {
            CriticalUnblock unblock(CConnectionTable::crit); // allow others to connect
            StringBuffer eps;
            if (TF_TRACE_CLIENT_CONN) {
                ep.getUrlStr(eps);
                PROGLOG("Connecting to %s",eps.str());
                //PrintStackReport();
            }
            bool ok = true;
            try {
                if (tm.timemon) {
                    unsigned remaining;
                    tm.timemon->timedout(&remaining);
                    socket.setown(ISocket::connect_timeout(ep,remaining));
                }
                else
                    socket.setown(ISocket::connect(ep));
            } 
            catch (IJSOCK_Exception *e) {
                ok = false;
                if (!retries||(tm.timemon&&tm.timemon->timedout())) {
                    if (e->errorCode()==JSOCKERR_connection_failed) {
                        lastfailep.set(ep);
                        lastfailtime = msTick();
                        e->Release();
                        StringBuffer msg("Failed to connect to dafilesrv/daliservix on ");
                        ep.getUrlStr(msg);
                        throw createDafsException(DAFSERR_connection_failed,msg.str());
                    }
                    throw;
                }
                StringBuffer err;
                WARNLOG("Remote file connect %s",e->errorMessage(err).str());
                e->Release();
            }
            if (ok) {
                if (TF_TRACE_CLIENT_CONN) {
                    PROGLOG("Connected to %s",eps.str());
                }
                if (AuthenticationEnabled) {
                    try {
                        sendAuthentication(ep); // this will log error
                        break;
                    }
                    catch (IJSOCK_Exception *e) {
                        StringBuffer err;
                        WARNLOG("Remote file authenticate %s for %s ",e->errorMessage(err).str(),ep.getUrlStr(eps.clear()).str());
                        e->Release();
                        if (!retries) 
                            break;
                    }
                }
                else
                    break;
            }
            unsigned sleeptime = getRandom()%3000+1000;     
            if (tm.timemon) {
                unsigned remaining;
                tm.timemon->timedout(&remaining);
                if (remaining/2<sleeptime)
                    sleeptime = remaining/2;
            }
            Sleep(sleeptime);       // prevent multiple retries beating
            PROGLOG("Retrying connect");
        }  
        if (ConnectionTable)
            ConnectionTable->addLink(ep,socket);
    }

    void killSocket(SocketEndpoint &tep)
    {
        CriticalBlock block2(CConnectionTable::crit); // this is nested with crit
        if (socket) {
            try {
                Owned<ISocket> s = socket.getClear();
                if (ConnectionTable)
                    ConnectionTable->remove(tep,s);
            }
            catch (IJSOCK_Exception *e) {
                e->Release();   // ignore errors closing
            }
            Sleep(getRandom()%1000*5+500);      // prevent multiple beating
        }
    }

protected: friend class CRemoteFileIO;


    StringAttr          filename;
    CriticalSection     crit;
    SocketEndpoint      ep;
    

    void sendRemoteCommand(MemoryBuffer & src, MemoryBuffer & reply, bool retry=true, bool lengthy=false)
    {
        CriticalBlock block(crit);  // serialize commands on same file
        SocketEndpoint tep(ep);
        setDafsEndpointPort(tep);
        unsigned nretries = retry?3:0;
        Owned<IJSOCK_Exception> firstexc;   // when retrying return first error if fails
        loop {
            try {
                if (socket) {
                    sendBuffer(socket, src);
                    receiveBuffer(socket, reply, lengthy?LENGTHY_RETRIES:NORMAL_RETRIES);
                    break;
                }
            }
            catch (IJSOCK_Exception *e) {
                if (!nretries--) {
                    if (firstexc) {
                        e->Release();
                        e = firstexc.getClear();
                    }
                    killSocket(tep);
                    throw e;
                }
                StringBuffer str;
                e->errorMessage(str);
                WARNLOG("Remote File: %s, retrying (%d)",str.str(),nretries);
                if (firstexc)
                    e->Release();
                else
                    firstexc.setown(e);
                killSocket(tep);
            }
            CriticalBlock block2(CConnectionTable::crit); // this is nested with crit
            if (ConnectionTable) {

                socket.setown(ConnectionTable->lookup(tep));
                if (socket) {
                    // validate existing socket by sending an 'exists' command with short time out
                    // (use exists for backward compatibility)
                    bool ok = false;
                    try {
                        MemoryBuffer sendbuf;
                        initSendBuffer(sendbuf);
                        MemoryBuffer replybuf;
                        sendbuf.append((RemoteFileCommandType)RFCexists).append(filename);
                        sendBuffer(socket, sendbuf);
                        receiveBuffer(socket, replybuf, 0, 1024);
                        ok = true;
                    }
                    catch (IException *e) {
                        e->Release();
                    }
                    if (!ok) 
                        killSocket(tep);
                }
            }
            if (!socket) {
                connectSocket(tep);
            }

        }

        unsigned errCode;
        reply.read(errCode);
        if (errCode) {

            StringBuffer msg;
            if (filename.get())
                msg.append(filename);
            ep.getUrlStr(msg.append('[')).append("] ");
            size32_t pos = reply.getPos();
            if (pos<reply.length()) {
                size32_t len = reply.length()-pos;
                const byte *rest = reply.readDirect(len);
                if (errCode==RFSERR_InvalidCommand) {
                    const char *s = (const char *)rest;
                    const char *e = (const char *)rest+len;
                    while (*s&&(s!=e))
                        s++;
                    msg.append(s-(const char *)rest,(const char *)rest);
                }
                else if (len&&(rest[len-1]==0))
                    msg.append((const char *)rest);
                else {
                    msg.appendf("extra data[%d]",len); 
                    for (unsigned i=0;(i<16)&&(i<len);i++)
                        msg.appendf(" %2x",(int)rest[i]);
                }
            }
            else if(errCode == 8209)
                msg.append("Failed to open directory.");
            else 
                msg.append("ERROR #").append(errCode);
#ifdef _DEBUG
            ERRLOG("%s",msg.str());
            PrintStackReport();
#endif
            throw createDafsException(errCode,msg.str());
        }
    }   

    void sendRemoteCommand(MemoryBuffer & src, bool retry)
    {
        MemoryBuffer reply;
        sendRemoteCommand(src, reply, retry);
    }

    void throwUnauthenticated(const IpAddress &ip,const char *user,unsigned err=0)
    {
        if (err==0)
            err = RFSERR_AuthenticateFailed;
        StringBuffer msg;
        msg.appendf("Authentication for %s on ",user);
        ip.getIpText(msg);
        msg.append(" failed");
        throw createDafsException(err, msg.str());
    }

    void sendAuthentication(const IpAddress &serverip)
    {
        // send my sig
        // first send my sig which if stream unencrypted will get returned as a bad command
        OnceKey oncekey;
        genOnce(oncekey);
        MemoryBuffer sendbuf;
        initSendBuffer(sendbuf);
        MemoryBuffer replybuf;
        MemoryBuffer encbuf; // because aesEncrypt clears input
        sendbuf.append((RemoteFileCommandType)RFCunlock).append(sizeof(oncekey),&oncekey);
        try {
            sendBuffer(socket, sendbuf);
            receiveBuffer(socket, replybuf, NORMAL_RETRIES, 1024);
        }
        catch (IException *e)
        {
            EXCLOG(e,"Remote file - sendAuthentication(1)");
            throw;
        }
        unsigned errCode;
        replybuf.read(errCode);
        if (errCode!=0)  // no authentication required
            return;
        SocketEndpoint ep;
        ep.setLocalHost(0);
        byte ipdata[16];
        size32_t ipds = ep.getNetAddress(sizeof(ipdata),&ipdata);
        mergeOnce(oncekey,ipds,&ipdata);
        StringBuffer username;
        StringBuffer password;
        IPasswordProvider * pp = queryPasswordProvider();
        if (pp)
            pp->getPassword(serverip, username, password);
        if (!username.length())
            username.append("sds_system");      // default account (note if exists should have restricted access!)
        if (!password.length())
            password.append("sds_man");
        if (replybuf.remaining()<=sizeof(size32_t))
            throwUnauthenticated(serverip,username.str());
        size32_t bs;
        replybuf.read(bs);
        if (replybuf.remaining()<bs)
            throwUnauthenticated(serverip,username.str());
        MemoryBuffer skeybuf;
        aesDecrypt(&oncekey,sizeof(oncekey),replybuf.readDirect(bs),bs,skeybuf);
        if (skeybuf.remaining()<sizeof(OnceKey))
            throwUnauthenticated(serverip,username.str());
        OnceKey sokey;
        skeybuf.read(sizeof(OnceKey),&sokey); 
        // now we have the key to use to send user/password
        MemoryBuffer tosend;
        tosend.append((byte)2).append(username).append(password);
        initSendBuffer(sendbuf.clear());
        sendbuf.append((RemoteFileCommandType)RFCunlockreply);
        aesEncrypt(&sokey, sizeof(oncekey), tosend.toByteArray(), tosend.length(), encbuf); 
        sendbuf.append(encbuf.length());
        sendbuf.append(encbuf);
        try {
            sendBuffer(socket, sendbuf);
            receiveBuffer(socket, replybuf.clear(), NORMAL_RETRIES, 1024);
        }
        catch (IException *e)
        {
            EXCLOG(e,"Remote file - sendAuthentication(2)");
            throw;
        }
        replybuf.read(errCode);
        if (errCode==0)  // suceeded!
            return;
        throwUnauthenticated(serverip,username.str(),errCode);
    }

public:
    SocketEndpoint  &queryEp() { return ep; };


    CRemoteBase(const SocketEndpoint &_ep, const char * _filename)
        : filename(_filename)
    {
        ep = _ep;
    }


    void connect()
    {
        CriticalBlock block(crit);
        CriticalBlock block2(CConnectionTable::crit); // this shouldn't ever block
        if (AuthenticationEnabled) {
            SocketEndpoint tep(ep);
            setDafsEndpointPort(tep);
            connectSocket(tep);
        }
    }

    void disconnect()
    {
        CriticalBlock block(crit);
        CriticalBlock block2(CConnectionTable::crit); // this shouldn't ever block
        ISocket *s = socket.getClear();
        if (ConnectionTable) {
            SocketEndpoint tep(ep);
            setDafsEndpointPort(tep);
            ConnectionTable->remove(tep,s);
        }
        ::Release(s);
    }

    const char *queryLocalName()
    {
        return filename;
    }

};

SocketEndpoint  CRemoteBase::lastfailep;
unsigned CRemoteBase::lastfailtime;


//---------------------------------------------------------------------------

class CRemoteDirectoryIterator : public CInterface, implements IDirectoryDifferenceIterator
{
    Owned<IFile>    cur;
    bool            curvalid;
    bool            curisdir;
    StringAttr      curname;
    CDateTime       curdt;
    __int64         cursize;
    StringAttr      dir;
    SocketEndpoint  ep;
    byte            *flags;
    unsigned        numflags;
    unsigned        curidx;
    unsigned        mask;

    MemoryBuffer buf;
public:
    static CriticalSection      crit;

    CRemoteDirectoryIterator(SocketEndpoint &_ep,const char *_dir)
        : dir(_dir)
    {
        // an extended difference iterator starts with 2 (for bwd compatibility)
        ep = _ep;
        curisdir = false;
        curvalid = false;
        cursize = 0;
        curidx = (unsigned)-1;
        mask = 0;
        numflags = 0;
        flags = NULL;
    }

    bool appendBuf(MemoryBuffer &_buf)
    {
        buf.setSwapEndian(_buf.needSwapEndian());
        byte hdr;
        _buf.read(hdr);
        if (hdr==2) {
            _buf.read(numflags);
            flags = (byte *)malloc(numflags);
            _buf.read(numflags,flags);
        }
        else {
            buf.append(hdr);
            flags = NULL;
            numflags = 0;
        }
        size32_t rest = _buf.length()-_buf.getPos();
        const byte *rb = (const byte *)_buf.readDirect(rest);
        bool ret = true;
        if (rest&&(rb[rest-1]!=0)) {
            rest--;
            ret = false;  // continuation
        }
        buf.append(rest,rb);
        return ret;
    }

    ~CRemoteDirectoryIterator()
    {
        free(flags);
    }

    IMPLEMENT_IINTERFACE

    bool first()
    {
        curidx = (unsigned)-1;
        buf.reset();
        return next();
    }
    bool next()
    {
        loop {
            curidx++;
            cur.clear();
            curdt.clear();
            curname.clear();
            cursize = 0;
            curisdir = false;
            if (buf.getPos()>=buf.length())
                return false;
            byte b;
            buf.read(b);
            curvalid = b!=0;
            if (!curvalid) 
                return false;
            buf.read(curisdir);
            buf.read(cursize);
            curdt.deserialize(buf);
            buf.read(curname);
            // kludge for bug in old linux jlibs
            if (strchr(curname,'\\')&&(getPathSepChar(dir)=='/')) {
                StringBuffer temp(curname);
                temp.replace('\\','/');
                curname.set(temp.str());
            }
            if ((mask==0)||(getFlags()&mask))
                break;
        }
        return true;
    }

    bool isValid() 
    { 
        return curvalid; 
    }
    IFile & query() 
    { 
        if (!cur) {
            StringBuffer full(dir);
            addPathSepChar(full).append(curname);
            if (ep.isNull())
                cur.setown(createIFile(full.str()));
            else {
                RemoteFilename rfn;
                rfn.setPath(ep,full.str());
                cur.setown(createIFile(rfn));
            }
        }
        return *cur; 
    }
    StringBuffer &getName(StringBuffer &buf)
    {
        return buf.append(curname);
    }
    bool isDir() 
    { 
        return curisdir; 
    }

    __int64 getFileSize()
    {
        if (curisdir)
            return -1;
        return cursize;
    }


    bool getModifiedTime(CDateTime &ret)
    {
        ret = curdt;
        return true;
    }

    void setMask(unsigned _mask)
    {
        mask = _mask;
    }
    
    virtual unsigned getFlags()
    {
        if (flags&&(curidx<numflags))
            return flags[curidx];
        return 0;
    }

    static bool serialize(MemoryBuffer &mb,IDirectoryIterator *iter, size32_t bufsize, bool first)
    {
        bool ret = true;
        byte b=1;
        StringBuffer tmp;
        if (first ? iter->first() : iter->next()) {
            loop {
                mb.append(b);
                bool isdir = iter->isDir();
                __int64 sz = isdir?0:iter->getFileSize();
                CDateTime dt;
                iter->getModifiedTime(dt);
                iter->getName(tmp.clear());
                mb.append(isdir).append(sz);
                dt.serialize(mb);
                mb.append(tmp.str());
                if (bufsize&&(mb.length()>=bufsize-1)) {
                    ret = false;
                    break;
                }
                if (!iter->next())
                    break;
            }
        }               
        b = 0;
        mb.append(b);   
        return ret;
    }

    static void serializeDiff(MemoryBuffer &mb,IDirectoryDifferenceIterator *iter)
    {
        // bit slow
        MemoryBuffer flags;
        ForEach(*iter) 
            flags.append((byte)iter->getFlags());
        if (flags.length()) {
            byte b = 2;
            mb.append(b).append((unsigned)flags.length()).append(flags);
        }
        serialize(mb,iter,0,true);
    }

    void serialize(MemoryBuffer &mb,bool isdiff)
    {
        byte b;
        if (isdiff&&numflags&&flags) {
            b = 2;
            mb.append(b).append(numflags).append(numflags,flags);
        }
        serialize(mb,this,0,true);
    }

};

class CCritTable;
class CEndpointCS : public CriticalSection, public CInterface
{
    CCritTable &table;
    const SocketEndpoint ep;
public:
    CEndpointCS(CCritTable &_table, const SocketEndpoint &_ep) : table(_table), ep(_ep) { }
    const void *queryFindParam() const { return &ep; }

    virtual void beforeDispose();
};

class CCritTable : private SimpleHashTableOf<CEndpointCS, const SocketEndpoint>
{
    typedef SimpleHashTableOf<CEndpointCS, const SocketEndpoint> PARENT;
    CriticalSection crit;
public:
    CEndpointCS *getCrit(const SocketEndpoint &ep)
    {
        CriticalBlock b(crit);
        Linked<CEndpointCS> clientCrit = find(ep);
        if (!clientCrit || !clientCrit->isAlive()) // if !isAlive(), then it is in the process of being destroyed/removed.
        {
            clientCrit.setown(new CEndpointCS(*this, ep));
            replace(*clientCrit); // NB table doesn't own
        }
        return clientCrit.getClear();
    }
    void removeExact(CEndpointCS *clientCrit)
    {
        CriticalBlock b(crit);
        PARENT::removeExact(clientCrit); // NB may not exist, could have been replaced if detected !isAlive() in getCrit()
    }
} *dirCSTable;

MODULE_INIT(INIT_PRIORITY_STANDARD)
{
    dirCSTable = new CCritTable;
    return true;
}
MODULE_EXIT()
{
    delete dirCSTable;
}

void CEndpointCS::beforeDispose()
{
    table.removeExact(this);
}


class CRemoteFile : public CRemoteBase, implements IFile
{
    StringAttr remotefilename;
    unsigned flags;
public:
    IMPLEMENT_IINTERFACE
    CRemoteFile(const SocketEndpoint &_ep, const char * _filename)
        : CRemoteBase(_ep, _filename)
    {
        flags = ((unsigned)IFSHread)|((S_IRUSR|S_IWUSR)<<16);
    }

    bool exists()
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCexists).append(filename);
        sendRemoteCommand(sendBuffer, replyBuffer);
        
        bool ok;
        replyBuffer.read(ok);
        return ok;
    }

    bool getTime(CDateTime * createTime, CDateTime * modifiedTime, CDateTime * accessedTime)
    {
        CDateTime dummyTime;
        if (!createTime)
            createTime = &dummyTime;
        if (!modifiedTime)
            modifiedTime = &dummyTime;
        if (!accessedTime)
            accessedTime = &dummyTime;
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCgettime).append(filename);
        sendRemoteCommand(sendBuffer, replyBuffer);
        
        bool ok;
        replyBuffer.read(ok);
        if (ok) {
            createTime->deserialize(replyBuffer);
            modifiedTime->deserialize(replyBuffer);
            accessedTime->deserialize(replyBuffer);
        }
        return ok;
    }

    bool setTime(const CDateTime * createTime, const CDateTime * modifiedTime, const CDateTime * accessedTime)
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCsettime).append(filename);
        if (createTime) {
            sendBuffer.append((bool)true);
            createTime->serialize(sendBuffer);
        }
        else
            sendBuffer.append((bool)false);
        if (modifiedTime) {
            sendBuffer.append((bool)true);
            modifiedTime->serialize(sendBuffer);
        }
        else
            sendBuffer.append((bool)false);
        if (accessedTime) {
            sendBuffer.append((bool)true);
            accessedTime->serialize(sendBuffer);
        }
        else
            sendBuffer.append((bool)false);
        sendRemoteCommand(sendBuffer, replyBuffer);
        
        bool ok;
        replyBuffer.read(ok);
        return ok;
    }

    fileBool isDirectory()
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCisdirectory).append(filename);
        sendRemoteCommand(sendBuffer, replyBuffer);
        
        unsigned ret;
        replyBuffer.read(ret);
        return (fileBool)ret;
    }


    fileBool isFile()
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCisfile).append(filename);
        sendRemoteCommand(sendBuffer, replyBuffer);
        
        unsigned ret;
        replyBuffer.read(ret);
        return (fileBool)ret;
    }

    fileBool isReadOnly()
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCisreadonly).append(filename);
        sendRemoteCommand(sendBuffer, replyBuffer);
        
        unsigned ret;
        replyBuffer.read(ret);
        return (fileBool)ret;
    }

    IFileIO * open(IFOmode mode);
    IFileIO * openShared(IFOmode mode,IFSHmode shmode);
    IFileAsyncIO * openAsync(IFOmode mode) { return NULL; } // not supported

    const char * queryFilename()
    {
        if (remotefilename.isEmpty()) {
            RemoteFilename rfn;
            rfn.setPath(ep,filename);
            StringBuffer path;
            rfn.getRemotePath(path);
            remotefilename.set(path);
        }
        return remotefilename.get();
    }

    void resetLocalFilename(const char *name)
    {
        remotefilename.clear();
        filename.set(name);
    }

    bool remove()
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCremove).append(filename);
        sendRemoteCommand(sendBuffer, replyBuffer);

        bool ok;
        replyBuffer.read(ok);
        return ok;
    }

    void rename(const char *newname)
    {
    // currently ignores directory on newname (in future versions newname will be required to be tail only and not full path)
        StringBuffer path;
        splitDirTail(filename,path);
        StringBuffer newdir;
        path.append(splitDirTail(newname,newdir));
        if (newdir.length()&&(strcmp(newdir.str(),path.str())!=0)) 
            WARNLOG("CRemoteFile::rename passed full path '%s' that may not to match original directory '%s'",newname,path.str());
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCrename).append(filename).append(path);
        sendRemoteCommand(sendBuffer, replyBuffer);
        filename.set(path);
        remotefilename.clear();
    }

    void move(const char *newname)
    {
        // like rename except between directories
        // first create replote path
        if (!newname||!*newname)
            return;
        RemoteFilename destrfn;
        if (isPathSepChar(newname[0])&&isPathSepChar(newname[1])) {
            destrfn.setRemotePath(newname);
            if (!destrfn.queryEndpoint().ipequals(ep)) {
                StringBuffer msg;
                msg.appendf("IFile::move %s to %s, destination node must match source node", queryFilename(), newname);
                throw createDafsException(RFSERR_MoveFailed,msg.str());
            }
        }
        else
            destrfn.setPath(ep,newname);
        StringBuffer dest;
        newname = destrfn.getLocalPath(dest).str();
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        StringBuffer path;
        splitDirTail(filename,path);
        StringBuffer newdir;
        const char *newtail = splitDirTail(newname,newdir);
        if (strcmp(newdir.str(),path.str())==0) {
            path.append(newtail);
            newname = path;
            sendBuffer.append((RemoteFileCommandType)RFCrename);    // use rename if we can (supported on older dafilesrv)
        }
        else 
            sendBuffer.append((RemoteFileCommandType)RFCmove);
        sendBuffer.append(filename).append(newname);
        sendRemoteCommand(sendBuffer, replyBuffer);
        filename.set(newname);
        remotefilename.clear();
    }

    void setReadOnly(bool set)
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCsetreadonly).append(filename).append(set);
        sendRemoteCommand(sendBuffer, replyBuffer);
    }


    offset_t size()
    {
#if 1 // faster method (consistant with IFile)
        // do this by using dir call (could be improved with new function but this not *too* bad)
        if (isSpecialPath(filename))
            return 0;   // queries deemed to always exist (though don't know size).
                        // if needed to get size I guess could use IFileIO method and cache (bit of pain though)
        StringBuffer dir;
        const char *tail = splitDirTail(filename,dir);
        if (!dir.length())
            return false;
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        bool includedirs = true;
        bool sub=false;
        {
            //Could be removed with new dafilesrv change [ (stream != 0) ], since this is not streaming.
            Owned<CEndpointCS> crit = dirCSTable->getCrit(ep); // NB dirCSTable doesn't own, last reference will remove from table
            CriticalBlock block(*crit);
            sendBuffer.append((RemoteFileCommandType)RFCgetdir).append(dir).append(tail).append(includedirs).append(sub);
            sendRemoteCommand(sendBuffer, replyBuffer);
        }
        // now should be 0 or 1 files returned
        Owned<CRemoteDirectoryIterator> iter = new CRemoteDirectoryIterator(ep, dir.str());
        iter->appendBuf(replyBuffer);
        if (!iter->first())
            return (offset_t)-1;
        return (offset_t) iter->getFileSize();
#else
        IFileIO * io = open(IFOread);
        offset_t length = (offset_t)-1;
        if (io)
        {   
            length = io->size();
            io->Release();
        }
        return length;
#endif
    }

    bool createDirectory()
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCcreatedir).append(filename);
        sendRemoteCommand(sendBuffer, replyBuffer);

        bool ok;
        replyBuffer.read(ok);
        return ok;
    }

    virtual IDirectoryIterator *directoryFiles(const char *mask,bool sub,bool includedirs)
    {
        if (mask&&!*mask)
            return createDirectoryIterator("",""); // NULL iterator

        CRemoteDirectoryIterator *ret = new CRemoteDirectoryIterator(ep, filename);
        byte stream=1;

        Owned<CEndpointCS> crit = dirCSTable->getCrit(ep); // NB dirCSTable doesn't own, last reference will remove from table
        CriticalBlock block(*crit);
        loop {
            MemoryBuffer sendBuffer;
            initSendBuffer(sendBuffer);
            MemoryBuffer replyBuffer;
            sendBuffer.append((RemoteFileCommandType)RFCgetdir).append(filename).append(mask?mask:"").append(includedirs).append(sub).append(stream);
            sendRemoteCommand(sendBuffer, replyBuffer);
            if (ret->appendBuf(replyBuffer))
                break;
            stream = 2;
        }
        return ret;
    }

    IDirectoryDifferenceIterator *monitorDirectory(
                                  IDirectoryIterator *prev=NULL,    // in (NULL means use current as baseline)
                                  const char *mask=NULL,
                                  bool sub=false,
                                  bool includedirs=false,
                                  unsigned checkinterval=60*1000,
                                  unsigned timeout=(unsigned)-1,
                                  Semaphore *abortsem=NULL) // returns NULL if timed out
    {
        // abortsem not yet supported
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCmonitordir).append(filename).append(mask?mask:"").append(includedirs).append(sub);
        sendBuffer.append(checkinterval).append(timeout);
        __int64 cancelid=0; // not yet used
        sendBuffer.append(cancelid);
        byte isprev=(prev!=NULL)?1:0;
        sendBuffer.append(isprev);
        if (prev) 
            CRemoteDirectoryIterator::serialize(sendBuffer,prev,0,true);
        sendRemoteCommand(sendBuffer, replyBuffer);
        byte status;
        replyBuffer.read(status);
        if (status==1) {
            CRemoteDirectoryIterator *iter = new CRemoteDirectoryIterator(ep, filename);
            iter->appendBuf(replyBuffer);
            return iter;
        }
        return NULL;
    }

    bool getInfo(bool &isdir,offset_t &size,CDateTime &modtime)
    {
        // do this by using dir call (could be improved with new function but this not *too* bad)
        StringBuffer dir;
        const char *tail = splitDirTail(filename,dir);
        if (!dir.length())
            return false;
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        bool includedirs = true;
        bool sub=false;
        {
            //Could be removed with new dafilesrv change [ (stream != 0) ], since this is not streaming.
            Owned<CEndpointCS> crit = dirCSTable->getCrit(ep); // NB dirCSTable doesn't own, last reference will remove from table
            CriticalBlock block(*crit);
            sendBuffer.append((RemoteFileCommandType)RFCgetdir).append(dir).append(tail).append(includedirs).append(sub);
            sendRemoteCommand(sendBuffer, replyBuffer);
        }
        // now should be 0 or 1 files returned
        Owned<CRemoteDirectoryIterator> iter = new CRemoteDirectoryIterator(ep, dir.str());
        iter->appendBuf(replyBuffer);
        if (!iter->first())
            return false;
        isdir = iter->isDir();
        size = (offset_t) iter->getFileSize();
        iter->getModifiedTime(modtime);
        return true;
    }



    bool setCompression(bool set)
    {
        assertex(!"Need to implement compress()");
        return false;
    }

    offset_t compressedSize()
    {
        assertex(!"Need to implement actualSize()");
        return (offset_t)-1;
    }

    void serialize(MemoryBuffer &tgt)
    {
        throwUnexpected();
    }

    void deserialize(MemoryBuffer &src)
    {
        throwUnexpected();
    }

    unsigned getCRC()
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCgetcrc).append(filename);
        sendRemoteCommand(sendBuffer, replyBuffer, true, true);
        
        unsigned crc;
        replyBuffer.read(crc);
        return crc;
    }

    void setCreateFlags(unsigned cflags)
    {
        flags |= (cflags<<16);
    }

    void setShareMode(IFSHmode shmode)
    {
        flags &= ~(IFSHfull|IFSHread);
        flags |= (unsigned)(shmode&(IFSHfull|IFSHread));
    }

    void remoteExtractBlobElements(const char * prefix, ExtractedBlobArray & extracted)
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        sendBuffer.append((RemoteFileCommandType)RFCextractblobelements).append(prefix).append(filename);
        MemoryBuffer replyBuffer;
        sendRemoteCommand(sendBuffer, replyBuffer, true, true); // handles error code
        unsigned n;
        replyBuffer.read(n);
        for (unsigned i=0;i<n;i++) {
            ExtractedBlobInfo *item = new ExtractedBlobInfo;
            item->deserialize(replyBuffer);
            extracted.append(*item);
        }
    }

    bool copySectionAsync(const char *uuid,const RemoteFilename &dest, offset_t toOfs, offset_t fromOfs, offset_t size, ICopyFileProgress *progress, unsigned timeout)
    {
        // now if we get here is it can be assumed the source file is local to where we send the command
        StringBuffer tos;
        dest.getRemotePath(tos);
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCcopysection).append(uuid).append(queryLocalName()).append(tos).append(toOfs).append(fromOfs).append(size).append(timeout);
        sendRemoteCommand(sendBuffer, replyBuffer);
        unsigned status;
        replyBuffer.read(status);
        if (progress) {
            offset_t sizeDone;
            offset_t totalSize;
            replyBuffer.read(sizeDone).read(totalSize);
            progress->onProgress(sizeDone,totalSize);
        }
        return (AsyncCommandStatus)status!=ACScontinue; // should only otherwise be done as errors raised by exception
    }

    void copySection(const RemoteFilename &dest, offset_t toOfs, offset_t fromOfs, offset_t size, ICopyFileProgress *progress)
    {
        StringBuffer uuid;
        genUUID(uuid,true);
        unsigned timeout = 60*1000; // check every minute
        while(!copySectionAsync(uuid.str(),dest,toOfs,fromOfs,size,progress,timeout));
    }

    void copyTo(IFile *dest, size32_t buffersize, ICopyFileProgress *progress, bool usetmp);

    virtual IMemoryMappedFile *openMemoryMapped(offset_t ofs, memsize_t len, bool write)
    {
        return NULL;
    }

    void treeCopyTo(IFile *dest,IpSubNet &subnet,IpAddress &resfrom,bool usetmp)
    {
        resfrom.ipset(NULL);
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)(usetmp?RFCtreecopytmp:RFCtreecopy));
        RemoteFilename rfn;
        rfn.setPath(ep,filename);
        rfn.serialize(sendBuffer);
        const char *d = dest->queryFilename();
        if (!isAbsolutePath(d)) 
            throw MakeStringException(-1,"treeCopyFile destination '%s' is not an absolute path", d);
        rfn.setRemotePath(d);
        rfn.serialize(sendBuffer);
        StringBuffer tmp;
        subnet.getNetText(tmp);
        sendBuffer.append(tmp);
        subnet.getMaskText(tmp.clear());
        sendBuffer.append(tmp);
        unsigned status=1;
        try {
            sendRemoteCommand(sendBuffer, replyBuffer);
            replyBuffer.read(status);
        }
        catch (IDAFS_Exception *e) {
            if (e->errorCode()!=RFSERR_InvalidCommand) 
                throw;
            e->Release();
            status = (unsigned)-1;
        }
        if (status==-1) {
            resfrom.ipset(ep);
            StringBuffer tmp;
            WARNLOG("dafilesrv on %s does not support treeCopyTo - falling back to copyTo",resfrom.getIpText(tmp).str());
            copyTo(dest,0x100000,NULL,usetmp);
            status = 0;
        }
        else if (status==0)
            resfrom.ipdeserialize(replyBuffer);
    }



};

void clientCacheFileConnect(SocketEndpoint &_ep,unsigned timeout)
{
    if (!timeout) {
        SocketEndpoint ep(_ep);
        setDafsEndpointPort(ep);
        Owned<CRemoteFile> cfile = new CRemoteFile(ep, "null");
        cfile->connect();
        return; // frees file and adds its socket to cache
    }
    // timeout needed so start a thread (that may become orphaned)
    class cThread: public Thread
    {
        SocketEndpoint ep;
    public:
        cThread(SocketEndpoint &_ep)
            : Thread("cacheFileConnect")
        {
            ep = _ep;
        }
        int run()
        {
            try {
                clientCacheFileConnect(ep,0);
            }
            catch (IException *e) {
                CriticalBlock block(sect);
                except.setown(e);
            }
            return 0;
        }
        Owned<IException> except;
        CriticalSection sect;
        
    } *thread;
    thread = new cThread(_ep);
    thread->start();
    IException *e =NULL;
    if (!thread->join(timeout)) {
        StringBuffer msg("Timed out connecting to ");
        _ep.getUrlStr(msg);
        e =  createDafsException(RFSERR_AuthenticateFailed,msg.str());
    }
    {
        CriticalBlock block(thread->sect);
        if (!e&&thread->except) 
            e = thread->except.getClear();
    }
    thread->Release();
    if (e)
        throw e;
}

void clientAddSocketToCache(SocketEndpoint &ep,ISocket *socket)
{
    CriticalBlock block(CConnectionTable::crit); 
    if (ConnectionTable)
        ConnectionTable->addLink(ep,socket);
}


IFile * createRemoteFile(SocketEndpoint &ep, const char * filename)
{
    IFile *ret = createFileLocalMount(ep,filename);
    if (ret)
        return ret;
    return new CRemoteFile(ep, filename);
}


void clientDisconnectRemoteFile(IFile *file)
{
    CRemoteFile *cfile = QUERYINTERFACE(file,CRemoteFile);
    if (cfile)
        cfile->disconnect();
}

bool clientResetFilename(IFile *file, const char *newname) // returns false if not remote
{
    CRemoteFile *cfile = QUERYINTERFACE(file,CRemoteFile);
    if (!cfile) 
        return false;
    cfile->resetLocalFilename(newname);
    return true;
}



extern bool clientAsyncCopyFileSection(const char *uuid,
                        IFile *from,                        // expected to be remote
                        RemoteFilename &to,
                        offset_t toOfs,                     // -1 created file and copies to start
                        offset_t fromOfs,
                        offset_t size,
                        ICopyFileProgress *progress,
                        unsigned timeout)       // returns true when done
{
    CRemoteFile *cfile = QUERYINTERFACE(from,CRemoteFile);
    if (!cfile) {
        // local - do sync
        from->copySection(to,toOfs,fromOfs,size,progress);
        return true;
    }
    return cfile->copySectionAsync(uuid,to,toOfs,fromOfs, size, progress, timeout);

}




//---------------------------------------------------------------------------

class CRemoteFileIO : public CInterface, implements IFileIO
{
protected:
    Linked<CRemoteFile> parent;
    RemoteFileIOHandle  handle;
    IFOmode mode;
    compatIFSHmode compatmode;
    bool disconnectonexit;
public:
    IMPLEMENT_IINTERFACE
    CRemoteFileIO(CRemoteFile *_parent)
        : parent(_parent)
    {
        handle = 0;
        disconnectonexit = false;
    }


    ~CRemoteFileIO()
    {
        if (handle) {
            try {
                MemoryBuffer sendBuffer;
                initSendBuffer(sendBuffer);
                sendBuffer.append((RemoteFileCommandType)RFCcloseIO).append(handle);
                parent->sendRemoteCommand(sendBuffer,false);
            }
            catch (IDAFS_Exception *e) {
                if ((e->errorCode()!=RFSERR_InvalidFileIOHandle)&&(e->errorCode()!=RFSERR_NullFileIOHandle)) { // ignore already disconnected
                    StringBuffer s;
                    e->errorMessage(s);
                    WARNLOG("CRemoteFileIO close file: %s",s.str());
                }
                e->Release();
                
            }
            catch (IException *e) {
                StringBuffer s;
                e->errorMessage(s);
                WARNLOG("CRemoteFileIO close file: %s",s.str());
                e->Release();
            }
        }
        if (disconnectonexit)
            parent->disconnect();
        handle = 0;
    }

    bool open(IFOmode _mode,compatIFSHmode _compatmode) 
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        const char *localname = parent->queryLocalName();
        localname = skipSpecialPath(localname);
        sendBuffer.append((RemoteFileCommandType)RFCopenIO).append(localname).append((byte)_mode).append((byte)_compatmode);
        parent->sendRemoteCommand(sendBuffer, replyBuffer);

        replyBuffer.read(handle);
        if (!handle)
            return false;
        switch (_mode) {
        case IFOcreate:
            mode = IFOwrite;
            break;
        case IFOcreaterw:
            mode = IFOreadwrite;
            break;
        default:
            mode = _mode;
        }
        compatmode = _compatmode;
        return true;
    }

    bool reopen() 
    {
        StringBuffer s;
        PROGLOG("Attempting reopen of %s on %s",parent->queryLocalName(),parent->queryEp().getUrlStr(s).str());
        if (open(mode,compatmode)) {
            return true;
        }
        return false;

    }


    offset_t size()
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCsize).append(handle);
        parent->sendRemoteCommand(sendBuffer, replyBuffer, false);                      
        // Retry using reopen TBD

        offset_t ret;
        replyBuffer.read(ret);
        return ret;
    }


    size32_t read(offset_t pos, size32_t len, void * data)
    {
        size32_t got;
        MemoryBuffer replyBuffer;
        const void *b = doRead(pos,len,replyBuffer,got,data);
        if (b!=data)
            memcpy(data,b,got);
        return got;
    }

    const void *doRead(offset_t pos, size32_t len, MemoryBuffer &replyBuffer, size32_t &got, void *dstbuf)
    {
        unsigned tries=0;
        loop {
            try {
                MemoryBuffer sendBuffer;
                initSendBuffer(sendBuffer);
                replyBuffer.clear();
                sendBuffer.append((RemoteFileCommandType)RFCread).append(handle).append(pos).append(len);
                parent->sendRemoteCommand(sendBuffer, replyBuffer,false);
                // kludge dafilesrv versions <= 1.5e don't return error correctly 
                if (replyBuffer.length()>len+sizeof(size32_t)+sizeof(unsigned)) {
                    size32_t save = replyBuffer.getPos();
                    replyBuffer.reset(len+sizeof(size32_t)+sizeof(unsigned));
                    unsigned errCode;
                    replyBuffer.read(errCode);
                    if (errCode) {
                        StringBuffer msg;
                        parent->ep.getUrlStr(msg.append('[')).append("] ");
                        if (replyBuffer.getPos()<replyBuffer.length()) {
                            StringAttr s;
                            replyBuffer.read(s);
                            msg.append(s);
                        }
                        else
                            msg.append("ERROR #").append(errCode);
                        throw createDafsException(errCode, msg.str());
                    }
                    else
                        replyBuffer.reset(save);
                }
                replyBuffer.read(got);
                if ((got>replyBuffer.remaining())||(got>len)) {
                    PROGLOG("Read beyond buffer %d,%d,%d",got,replyBuffer.remaining(),len);
                    throw createDafsException(RFSERR_ReadFailed, "Read beyond buffer");
                }
                return replyBuffer.readDirect(got);
            }
            catch (IJSOCK_Exception *e) {
                EXCLOG(e,"CRemoteFileIO::read");
                if (++tries>3)
                    throw;
                WARNLOG("Retrying read of %s (%d)",parent->queryLocalName(),tries);
                Owned<IException> exc = e;
                if (!reopen())
                    throw exc.getClear();
            }
        }
        got = 0;
        return NULL;
    }



    size32_t write(offset_t pos, size32_t len, const void * data)
    {
        unsigned tries=0;
        size32_t ret = 0;
        loop {
            try {
                MemoryBuffer replyBuffer;
                MemoryBuffer sendBuffer;
                initSendBuffer(sendBuffer);
                sendBuffer.append((RemoteFileCommandType)RFCwrite).append(handle).append(pos).append(len).append(len, data);
                parent->sendRemoteCommand(sendBuffer, replyBuffer, false, true);
                replyBuffer.read(ret);
                break;
            }
            catch (IJSOCK_Exception *e) {
                EXCLOG(e,"CRemoteFileIO::write");
                if (++tries>3)
                    throw;
                WARNLOG("Retrying write(%"I64F"d,%d) of %s (%d)",pos,len,parent->queryLocalName(),tries);
                Owned<IException> exc = e;
                if (!reopen())
                    throw exc.getClear();

            }
        }
        if ((ret==(size32_t)-1) || (ret < len))
            throw createDafsException(DISK_FULL_EXCEPTION_CODE,"write failed, disk full?");
        return ret;
    }

    offset_t appendFile(IFile *file,offset_t pos,offset_t len)
    {
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        const char * fname = file->queryFilename();
        sendBuffer.append((RemoteFileCommandType)RFCappend).append(handle).append(fname).append(pos).append(len);
        parent->sendRemoteCommand(sendBuffer, replyBuffer, false, true); // retry not safe
        
        offset_t ret;
        replyBuffer.read(ret);

        if ((ret==(offset_t)-1) || (ret < len))
            throw createDafsException(DISK_FULL_EXCEPTION_CODE,"append failed, disk full?");    // though could be file missing TBD
        return ret;
    }


    void setSize(offset_t size) 
    { 
        MemoryBuffer sendBuffer;
        initSendBuffer(sendBuffer);
        MemoryBuffer replyBuffer;
        sendBuffer.append((RemoteFileCommandType)RFCsetsize).append(handle).append(size);
        parent->sendRemoteCommand(sendBuffer, replyBuffer, false, true);
        // retry using reopen TBD


    }

    void setDisconnectOnExit(bool set) { disconnectonexit = set; }
};

void clientDisconnectRemoteIoOnExit(IFileIO *fileio,bool set)
{
    CRemoteFileIO *cfileio = QUERYINTERFACE(fileio,CRemoteFileIO);
    if (cfileio)
        cfileio->setDisconnectOnExit(set);
}



IFileIO * CRemoteFile::openShared(IFOmode mode,IFSHmode shmode)
{
    assertex(((unsigned)shmode&0xffffffc7)==0);
    compatIFSHmode compatmode;
    unsigned fileflags = (flags>>16) &  (S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IWGRP|S_IXGRP|S_IROTH|S_IWOTH|S_IXOTH);
    if (fileflags&S_IXUSR)                      // this is bit hit and miss but backward compatible
        compatmode = compatIFSHexec;
    else if (fileflags&(S_IWGRP|S_IWOTH))
        compatmode = compatIFSHall;
    else if (shmode&IFSHfull)
        compatmode = compatIFSHwrite;
    else if (((shmode&(IFSHread|IFSHfull))==0) && ((fileflags&(S_IRGRP|S_IROTH))==0))
        compatmode = compatIFSHnone;
    else
        compatmode = compatIFSHread;
    Owned<CRemoteFileIO> res = new CRemoteFileIO(this);
    if (res->open(mode,compatmode))
        return res.getClear();
    return NULL;
}

IFileIO * CRemoteFile::open(IFOmode mode)
{
    return openShared(mode,(IFSHmode)(flags&(IFSHread|IFSHfull)));
}

//---------------------------------------------------------------------------

void CRemoteFile::copyTo(IFile *dest, size32_t buffersize, ICopyFileProgress *progress, bool usetmp)
{
    CRemoteFile *dstfile = QUERYINTERFACE(dest,CRemoteFile);
    if (dstfile&&!dstfile->queryEp().isLocal()) {
        StringBuffer tmpname;
        Owned<IFile> destf;
        RemoteFilename dest;
        if (usetmp) {
            makeTempCopyName(tmpname,dstfile->queryLocalName());
            dest.setPath(dstfile->queryEp(),tmpname.str());
        }
        else
            dest.setPath(dstfile->queryEp(),dstfile->queryLocalName());
        destf.setown(createIFile(dest));
        try {
            // following may fail if new dafilesrv not deployed on src
            copySection(dest,(offset_t)-1,0,(offset_t)-1,progress);
            if (usetmp) {
                StringAttr tail(pathTail(dstfile->queryLocalName()));
                dstfile->remove();
                destf->rename(tail);
            }
            return;
        }
        catch (IException *e)
        {
            StringBuffer s;
            s.appendf("Remote File Copy (%d): ",e->errorCode());
            e->errorMessage(s);
            s.append(", retrying local");
            WARNLOG("%s",s.str());
            e->Release();
        }
        // delete dest
        try {
            destf->remove();
        }
        catch (IException *e)
        {
            EXCLOG(e,"Remote File Copy, Deleting temporary file");
            e->Release();
        }
    }
    // assumption if we get here that source remote, dest local (or equiv)
    class cIntercept: implements ICopyFileIntercept
    {
        MemoryAttr ma;
        MemoryBuffer mb;
        virtual offset_t copy(IFileIO *from, IFileIO *to, offset_t ofs, size32_t sz)
        {
            if (ma.length()<sz)
                ma.allocate(sz);    // may be not used
            void *buf = ma.bufferBase();
            size32_t got;
            CRemoteFileIO *srcio = QUERYINTERFACE(from,CRemoteFileIO);
            const void *dst;
            if (srcio) 
                dst = srcio->doRead(ofs,sz,mb.clear(),got,buf);
            else {
                // shouldn't ever get here if source remote
                got = from->read(ofs, sz, buf);
                dst = buf;
            }
            if (got != 0)
                to->write(ofs, got, dst);
            return got;
        }
    } intercept;
    doCopyFile(dest,this,buffersize,progress,&intercept,usetmp);
}


unsigned getRemoteVersion(ISocket * socket, StringBuffer &ver)
{
    static CriticalSection sect;
    CriticalBlock block(sect);
    if (!socket)
        return 0;
    unsigned ret;
    MemoryBuffer sendbuf;
    initSendBuffer(sendbuf);
    sendbuf.append((RemoteFileCommandType)RFCgetver);
    sendbuf.append((unsigned)RFCgetver);
    MemoryBuffer reply;
    try {
        sendBuffer(socket, sendbuf);
        receiveBuffer(socket, reply, 1 ,4096);
        unsigned errCode;
        reply.read(errCode);
        if (errCode==RFSERR_InvalidCommand) {
            ver.append("DS V1.0");
            return 10;
        }
        else if (errCode==0)
            ret = 11;
        else if (errCode<0x10000)
            return 0;
        else
            ret = errCode-0x10000;
    }
    catch (IException *e) {
        EXCLOG(e);
        ::Release(e);
        return 0;
    }
    StringAttr vers;
    reply.read(vers);
    ver.append(vers);
    return ret;
}


extern unsigned stopRemoteServer(ISocket * socket)
{
    static CriticalSection sect;
    CriticalBlock block(sect);
    if (!socket)
        return 0;
    MemoryBuffer sendbuf;
    initSendBuffer(sendbuf);
    sendbuf.append((RemoteFileCommandType)RFCstop);
    sendbuf.append((unsigned)RFCstop);
    MemoryBuffer replybuf;
    unsigned errCode = RFSERR_InvalidCommand;
    try {
        sendBuffer(socket, sendbuf);
        receiveBuffer(socket, replybuf, NORMAL_RETRIES, 1024);
        replybuf.read(errCode);
    }
    catch (IJSOCK_Exception *e) { 
        if ((e->errorCode()!=JSOCKERR_broken_pipe)&&(e->errorCode()!=JSOCKERR_graceful_close)) 
            EXCLOG(e);
        else
            errCode = 0;
    }
    catch (IException *e) {
        EXCLOG(e);
        ::Release(e);
    }
    return errCode;
}

int remoteExec(ISocket * socket, const char *cmdline, const char *workdir,bool sync,
                size32_t insize, void *inbuf, MemoryBuffer *outbuf)
{
    if (!socket)
        return -1;
    bool hasoutput = (outbuf!=NULL);
    if (!inbuf)
        insize = 0;
    MemoryBuffer sendbuf;
    initSendBuffer(sendbuf);
    sendbuf.append((RemoteFileCommandType)RFCexec).append(cmdline).append(workdir).append(sync).
               append(hasoutput).append(insize);
    if (insize)
        sendbuf.append(insize, inbuf);
    MemoryBuffer replybuf;
    try {
        sendBuffer(socket, sendbuf);
        receiveBuffer(socket, replybuf, LENGTHY_RETRIES); // we don't know how long program will take really - assume <1hr
        int retcode;
        unsigned phandle;
        size32_t outsz;
        replybuf.read(retcode).read(phandle).read(outsz);
        if (outsz&&outbuf)
            replybuf.read(outsz,outbuf->reserve(outsz));
        return retcode;
    }
    catch (IException *e) {
        EXCLOG(e);
        ::Release(e);
    }

    return -1;
}

int setDafsTrace(ISocket * socket,byte flags)
{
    if (!socket) {
        byte ret = traceFlags;
        traceFlags = flags;
        return ret;
    }
    MemoryBuffer sendbuf;
    initSendBuffer(sendbuf);
    sendbuf.append((RemoteFileCommandType)RFCsettrace).append(flags);
    MemoryBuffer replybuf;
    try {
        sendBuffer(socket, sendbuf);
        receiveBuffer(socket, replybuf, NORMAL_RETRIES, 1024);
        int retcode;
        replybuf.read(retcode);
        return retcode;
    }
    catch (IException *e) {
        EXCLOG(e);
        ::Release(e);
    }
    return -1;
}


int getDafsInfo(ISocket * socket,StringBuffer &retstr)
{
    if (!socket) {
        retstr.append(VERSTRING);
        return 0;
    }
    MemoryBuffer sendbuf;
    initSendBuffer(sendbuf);
    sendbuf.append((RemoteFileCommandType)RFCgetinfo);
    MemoryBuffer replybuf;
    try {
        sendBuffer(socket, sendbuf);
        receiveBuffer(socket, replybuf, 1);
        int retcode;
        replybuf.read(retcode);
        if (retcode==0) {
            StringAttr s;
            replybuf.read(s);
            retstr.append(s);
        }
        return retcode;
    }
    catch (IException *e) {
        EXCLOG(e);
        ::Release(e);
    }
    return -1;
}



void remoteExtractBlobElements(const SocketEndpoint &ep,const char * prefix, const char * filename, ExtractedBlobArray & extracted)
{
    Owned<CRemoteFile> file = new CRemoteFile (ep,filename);
    file->remoteExtractBlobElements(prefix, extracted);
}

//====================================================================================================


class CAsyncCommandManager
{

    class CAsyncJob: public CInterface
    {
        class cThread: public Thread
        {
            CAsyncJob *parent;
        public:
            cThread(CAsyncJob *_parent)
                : Thread("CAsyncJob")
            {
                parent = _parent;
            }
            int run()
            {
                int ret;
                try {
                    ret = parent->run();
                    parent->setDone();
                }
                catch (IException *e)
                {
                    parent->setException(e);
                }
                parent->threadsem.signal();
                return ret;
            }
        } *thread;
        StringAttr uuid;
    public:
        Semaphore &threadsem;
        CAsyncJob(const char *_uuid,Semaphore &_threadsem)
            : uuid(_uuid),threadsem(_threadsem)
        {
            thread = new cThread(this);
            hash = hashc((const byte *)uuid.get(),uuid.length(),~0U);
        }
        ~CAsyncJob()
        {
            thread->join();
            thread->Release();
        }
        static void destroy(CAsyncJob *j)
        {
            j->Release();
        }
        void start()
        {
            threadsem.wait();
            thread->start();
        }
        void join()
        {
            thread->join();
        }
        static unsigned getHash(const char *key)
        {
            return hashc((const byte *)key,strlen(key),~0U);
        }
        static CAsyncJob* create(const char *key) { assertex(!"CAsyncJob::create not implemented"); return NULL; }
        unsigned hash;
        bool eq(const char *key)
        {
            return stricmp(key,uuid.get())==0;
        }
        virtual int run()=0;
        virtual void setException(IException *e)=0;
        virtual void setDone()=0;
    };

    class CAsyncCopySection: public CAsyncJob
    {
        Owned<IFile> src;
        RemoteFilename dst;
        offset_t toOfs;
        offset_t fromOfs;
        offset_t size;
        CFPmode mode; // not yet supported
        CriticalSection sect;
        offset_t done;
        offset_t total;
        Semaphore finished;
        AsyncCommandStatus status;
        Owned<IException> exc;
    public:
        CAsyncCopySection(const char *_uuid, const char *fromFile, const char *toFile, offset_t _toOfs, offset_t _fromOfs, offset_t _size, Semaphore &threadsem)
            : CAsyncJob(_uuid,threadsem)
        {
            status = ACScontinue;
            src.setown(createIFile(fromFile));
            dst.setRemotePath(toFile);
            toOfs = _toOfs;
            fromOfs = _fromOfs;
            size = _size;
            mode = CFPcontinue;
            done = 0;
            total = (offset_t)-1;
        }
        AsyncCommandStatus poll(offset_t &_done, offset_t &_total,unsigned timeout)
        {
            if (timeout&&finished.wait(timeout)) 
                finished.signal();      // may need to call again
            CriticalBlock block(sect);
            if (exc) 
                throw exc.getClear();
            _done = done;
            _total = total;
            return status;
        }
        int run()
        {
            class cProgress: implements ICopyFileProgress
            {
                CriticalSection &sect;
                CFPmode &mode;
                offset_t &done;
                offset_t &total;
            public:
                cProgress(CriticalSection &_sect,offset_t &_done,offset_t &_total,CFPmode &_mode)
                    : sect(_sect), done(_done), total(_total), mode(_mode)
                {
                }
                CFPmode onProgress(offset_t sizeDone, offset_t totalSize)
                {
                    CriticalBlock block(sect);
                    done = sizeDone;
                    total = totalSize;
                    return mode;
                }
            } progress(sect,total,done,mode);
            src->copySection(dst,toOfs, fromOfs, size, &progress);  // exceptions will be handled by base class
            return 0;
        }
        void setException(IException *e)
        {
            EXCLOG(e,"CAsyncCommandManager::CAsyncJob"); 
            CriticalBlock block(sect);
            if (exc.get())
                e->Release();
            else
                exc.setown(e);
            status = ACSerror;
        }
        void setDone()
        {
            CriticalBlock block(sect);
            finished.signal();
            status = ACSdone;
        }
    };

    CMinHashTable<CAsyncJob> jobtable;
    CriticalSection sect;
    Semaphore threadsem;

public:

    CAsyncCommandManager()
    {
        threadsem.signal(10); // max number of async jobs
    }
    void join()
    {
        CriticalBlock block(sect);
        unsigned i;
        CAsyncJob *j=jobtable.first(i);
        while (j) {
            j->join();
            j=jobtable.next(i);
        }
    }

    AsyncCommandStatus copySection(const char *uuid, const char *fromFile, const char *toFile, offset_t toOfs, offset_t fromOfs, offset_t size, offset_t &done, offset_t &total, unsigned timeout)
    {
        // return 0 if continuing, 1 if done
        CAsyncCopySection * job;
        Linked<CAsyncJob> cjob;
        {
            CriticalBlock block(sect);
            cjob.set(jobtable.find(uuid,false));
            if (cjob) {
                job = QUERYINTERFACE(cjob.get(),CAsyncCopySection);
                if (!job) {
                    throw MakeStringException(-1,"Async job ID mismatch");  
                }
            }
            else {
                job = new CAsyncCopySection(uuid, fromFile, toFile, toOfs, fromOfs, size, threadsem);
                cjob.setown(job);
                jobtable.add(cjob.getLink());
                cjob->start();
            }
        }
        AsyncCommandStatus ret;
        Owned<IException> rete;
        try {
            ret = job->poll(done,total,timeout);
        }
        catch (IException * e) {
            rete.setown(e);
        }
        if ((ret!=ACScontinue)||rete.get()) {
            job->join();
            CriticalBlock block(sect);
            jobtable.remove(job);
            if (rete.get())
                throw rete.getClear();
        }
        return ret;
    }
};


//====================================================================================================



#define throwErr3(e,v,s) { StringBuffer msg; \
                           msg.appendf("ERROR: %s(%d) '%s'",#e,v,s?s:""); \
                           reply.append(e); reply.append(msg.str()); } 

#define throwErr(e)     { reply.append(e).append(#e); }
#define throwErr2(e,v)      { StringBuffer tmp; tmp.append(#e).append(':').append(v); reply.append(e).append(tmp.str()); }



#define MAPCOMMAND(c,p) case c: { ret =  this->p(msg, reply) ; break; }
#define MAPCOMMANDCLIENT(c,p,client) case c: { ret = this->p(msg, reply, client); break; }
#define MAPCOMMANDCLIENTTHROTTLER(c,p,client,throttler) case c: { ret = this->p(msg, reply, client, throttler); break; }

static unsigned ClientCount = 0;
static unsigned MaxClientCount = 0;
static CriticalSection ClientCountSect;


class CRemoteFileServer : public CInterface, implements IRemoteFileServer, implements IThreadFactory
{
    int                 lasthandle;
    CriticalSection     sect;
    Owned<ISocket>      acceptsock;
    Owned<ISocketSelectHandler> selecthandler;
    Owned<IThreadPool>  threads;    // for commands
    bool stopping;
    unsigned clientcounttick;
    unsigned closedclients;
    CAsyncCommandManager asyncCommandManager;
    Semaphore throttlesem;
    atomic_t globallasttick;

    int getNextHandle()
    {
        // called in sect critical block
        loop {
            if (lasthandle==INT_MAX)
                lasthandle = 1;
            else
                lasthandle++;
            unsigned idx1;
            unsigned idx2;
            if (!findHandle(lasthandle,idx1,idx2))
                return lasthandle;
        }
    }

    bool findHandle(int handle,unsigned &clientidx,unsigned &handleidx)
    {
        // called in sect critical block
        clientidx = (unsigned)-1;
        handleidx = (unsigned)-1;
        ForEachItemIn(i,clients) {
            CRemoteClientHandler &client = clients.item(i);
            ForEachItemIn(j,client.handles) {
                if (client.handles.item(j)==handle) {
                    handleidx = j;
                    clientidx = i;
                    return true;
                }
            }
        }
        return false;
    }

    struct CRemoteClientHandler: public CInterface, implements ISocketSelectNotify
    {
        CRemoteFileServer *parent;
        Owned<ISocket> socket;
        Owned<IAuthenticatedUser> user;
        MemoryBuffer buf;
        bool selecthandled;
        size32_t left;
        IArrayOf<IFileIO>   openfiles;      // kept in sync with handles
        Owned<IDirectoryIterator> opendir;
        StringAttrArray     opennames;      // for debug
        IntArray            handles;
        unsigned            lasttick;
        atomic_t            &globallasttick;
        unsigned            previdx;        // for debug


        IMPLEMENT_IINTERFACE;
        
        CRemoteClientHandler(CRemoteFileServer *_parent,ISocket *_socket,IAuthenticatedUser *_user,atomic_t &_globallasttick)
            : socket(_socket), user(_user), globallasttick(_globallasttick)
        {
            previdx = (unsigned)-1;
            CriticalBlock block(ClientCountSect);
            if (++ClientCount>MaxClientCount) 
                MaxClientCount = ClientCount;
            if (TF_TRACE_CLIENT_CONN) {
                StringBuffer s;
                s.appendf("Connecting(%x) [%d,%d] to ",(unsigned)(long)this,ClientCount,MaxClientCount);
                peerName(s);
                PROGLOG("%s",s.str());
            }
            parent = _parent;
            left = 0;
            buf.setEndian(__BIG_ENDIAN); 
            selecthandled = false;
            touch();
        }
        ~CRemoteClientHandler()
        {   
            {
                CriticalBlock block(ClientCountSect);
                ClientCount--;
                if (TF_TRACE_CLIENT_CONN) {
                    PROGLOG("Disconnecting(%x) [%d,%d] ",(unsigned)(long)this,ClientCount,MaxClientCount);
                }
            }
            ISocket *sock = socket.getClear();
            try {
                sock->Release();
            }
            catch (IException *e) {
                EXCLOG(e,"~CRemoteClientHandler");
                e->Release();
            }
        }
        bool notifySelected(ISocket *sock,unsigned selected)
        {
            if (TF_TRACE_FULL)
                PROGLOG("notifySelected(%x)",(unsigned)(long)this);
            if (sock!=socket) 
                WARNLOG("notifySelected - invalid socket passed");
            size32_t avail = (size32_t)socket->avail_read();
            if (avail)
                touch();
            if (left==0) {
                try {
                    left = avail?receiveBufferSize(socket):0;
                }
                catch (IException *e) {
                    EXCLOG(e,"notifySelected(1)");
                    e->Release();
                    left = 0;
                }
                if (left) {
                    avail = (size32_t)socket->avail_read();
                    try {
                        buf.ensureCapacity(left);
                    }
                    catch (IException *e) {
                        EXCLOG(e,"notifySelected(2)");
                        e->Release();
                        left = 0;
                        // if too big then corrupted packet so read avail to try and consume
                        char fbuf[1024];
                        while (avail) {
                            size32_t rd = avail>sizeof(fbuf)?sizeof(fbuf):avail;
                            try {
                                socket->read(fbuf, rd); // don't need timeout here
                                avail -= rd;
                            }
                            catch (IException *e) {
                                EXCLOG(e,"notifySelected(2) flush");
                                e->Release();
                                break;
                            }
                        }
                        avail = 0;
                        left = 0;
                    }
                }
            }
            size32_t toread = left>avail?avail:left;
            if (toread) {
                try {
                    socket->read(buf.reserve(toread), toread);  // don't need timeout here
                }
                catch (IException *e) {
                    EXCLOG(e,"notifySelected(3)");
                    e->Release();
                    toread = left;
                    buf.clear();
                }
            }
            if (TF_TRACE_FULL)
                PROGLOG("notifySelected %d,%d",toread,left);
            if ((left!=0)&&(avail==0)) {
                WARNLOG("notifySelected: Closing mid packet, %d remaining", left);
                toread = left;
                buf.clear();
            }
            left -= toread;
            if (left==0)  {
                // DEBUG
                parent->notify(this);
            }
            return false;
        }

        void logPrevHandle()
        {
            if (previdx<opennames.ordinality()) 
                PROGLOG("Previous handle(%d): %s",handles.item(previdx),opennames.item(previdx).text.get());
        }


        void processCommand()
        {
            CThrottler throttler(parent->throttleSem());
            MemoryBuffer reply;
            parent->dispatchCommand(buf, initSendBuffer(reply), this, &throttler);
            buf.clear();
            sendBuffer(socket, reply);
        }

        bool immediateCommand() // returns false if socket closed or failure
        {
            try {
                buf.clear();
                touch();
                size32_t avail = (size32_t)socket->avail_read();
                if (avail==0)
                    return false;
                receiveBuffer(socket,buf, 5);   // shouldn't timeout as data is available
                touch();
                if (buf.length()==0)
                    return false;
                processCommand();
            }
            catch (IException *e) {
                EXCLOG(e,"CRemoteClientHandler::immediateCommand");
                e->Release();
                buf.clear();
                return false;
            }
            return true;
        }

        void process()
        {
            if (selecthandled) 
                processCommand(); // buffer already filled
            else {
                while (parent->threadRunningCount()<=TARGET_ACTIVE_THREADS) { // if too many threads add to select handler
                    int w = socket->wait_read(1000);
                    if (w==0)
                        break;
                    if ((w<0)||!immediateCommand()) {
                        if (w<0) 
                            WARNLOG("CRemoteClientHandler::main wait_read error");
                        parent->onCloseSocket(this,1);
                        return;
                    }
                }
                selecthandled = true;
                parent->addClient(this);    // add to select handler
            }
        }

        bool timedOut()
        {
            return (msTick()-lasttick)>CLIENT_TIMEOUT;
        }

        void touch()
        {
            lasttick = msTick();
            atomic_set(&globallasttick,lasttick);
        }

        bool peerName(StringBuffer &buf)
        {
            if (socket) {
                char name[256];
                name[0] = 0;
                int port = socket->peer_name(name,sizeof(name)-1);
                if (port>=0) {
                    buf.append(name);
                    if (port)
                        buf.append(':').append(port);
                    return true;
                }
            }
            return false;
        }

        bool getInfo(StringBuffer &str) 
        {
            str.append("client(");
            bool ok = peerName(str);
            unsigned ms = msTick();
            str.appendf("): last touch %d ms ago (%d, %d)",ms-lasttick,lasttick,ms);
            ForEachItemIn(i,handles) {
                str.appendf("\n  %d: ",handles.item(i));
                str.append(opennames.item(i).text);
            }
            return ok;
        }
    
    };

    class cCommandProcessor: public CInterface, implements IPooledThread
    {
        Owned<CRemoteClientHandler> client;

    public:
        IMPLEMENT_IINTERFACE;

        struct cCommandProcessorParams
        {
            CRemoteClientHandler *client; 
        };

        void init(void *_params)
        {
            cCommandProcessorParams &params = *(cCommandProcessorParams *)_params;
            client.setown(params.client);
        }

        void main()
        {
            // idea is that initially we process commands inline then pass over to select handler
            try {
                client->process();
            }
            catch (IException *e) {
                // suppress some errors
                EXCLOG(e,"cCommandProcessor::main");
                e->Release();
            }
            try {
                client.clear();
            }
            catch (IException *e) {
                // suppress some more errors clearing client
                EXCLOG(e,"cCommandProcessor::main(2)");
            }
        }
        bool stop()
        {
            return true;
        }
        bool canReuse()
        {
            return false; // want to free owned osocke
        }
    };

    IArrayOf<CRemoteClientHandler> clients;

    class cImpersonateBlock
    {
        CRemoteClientHandler &client;
    public:
        cImpersonateBlock(CRemoteClientHandler &_client)
            : client(_client)
        {
            if (client.user.get()) {
                if (TF_TRACE)
                    PROGLOG("Impersonate user: %s",client.user->username());
                client.user->impersonate();
            }
        }
        ~cImpersonateBlock()
        {
            if (client.user.get()) {
                if (TF_TRACE)
                    PROGLOG("Stop impersonating user: %s",client.user->username());
                client.user->revert();
            }
        }
    };

#define IMPERSONATE_USER(client) cImpersonateBlock ublock(client)

public:

    IMPLEMENT_IINTERFACE

    CRemoteFileServer()
    {
        throttlesem.signal(10);
        lasthandle = 0;
        selecthandler.setown(createSocketSelectHandler(NULL));
        threads.setown(createThreadPool("CRemoteFileServerPool",this,NULL,MAX_THREADS,60*1000,
#ifdef __64BIT__
            0,
#else
            0x10000,
#endif

        INFINITE,TARGET_MIN_THREADS));
        stopping = false;
        clientcounttick = msTick();
        closedclients = 0;
        atomic_set(&globallasttick,msTick());
    }

    ~CRemoteFileServer()
    {
#ifdef _DEBUG
        PROGLOG("Exiting CRemoteFileServer");
#endif
        asyncCommandManager.join();
        clients.kill();
#ifdef _DEBUG
        PROGLOG("Exited CRemoteFileServer");
#endif
    }


    //MORE: The file handles should timeout after a while, and accessing an old (invalid handle)
    // should throw a different exception
    bool checkFileIOHandle(MemoryBuffer &reply, int handle, IFileIO *&fileio, bool del=false)
    {
        CriticalBlock block(sect);
        fileio = NULL;
        if (handle<=0) {
            throwErr(RFSERR_NullFileIOHandle);
            return false;
        }
        unsigned clientidx;
        unsigned handleidx;
        if (findHandle(handle,clientidx,handleidx)) {
            CRemoteClientHandler &client = clients.item(clientidx);
            if (del) {
                client.handles.remove(handleidx);
                client.openfiles.remove(handleidx);
                client.opennames.remove(handleidx);
                client.previdx = (unsigned)-1;
            }
            else {
               fileio = &client.openfiles.item(handleidx);
               client.previdx = handleidx;
            }
            return true;
        }
        throwErr(RFSERR_InvalidFileIOHandle);
        return false;
    }

    void onCloseSocket(CRemoteClientHandler *client, int which) 
    {
        if (!client)
            return;
        CriticalBlock block(sect);
#ifdef _DEBUG
        StringBuffer s;
        client->peerName(s);
        PROGLOG("onCloseSocket(%d) %s",which,s.str());
#endif
        if (client->socket) {
            try {
                selecthandler->remove(client->socket);
            }
            catch (IException *e) {
                EXCLOG(e,"CRemoteFileServer::onCloseSocket.1");
                e->Release();
            }
        }
        try {
            clients.zap(*client);
        }
        catch (IException *e) {
            EXCLOG(e,"CRemoteFileServer::onCloseSocket.2");
            e->Release();
        }
    }


    bool cmdOpenFileIO(MemoryBuffer & msg, MemoryBuffer & reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        Owned<StringAttrItem> name = new StringAttrItem;
        byte mode;
        byte share;
        msg.read(name->text).read(mode).read(share);  
        try {
            Owned<IFile> file = createIFile(name->text);
            switch ((compatIFSHmode)share) {
            case compatIFSHnone:
                file->setCreateFlags(S_IRUSR|S_IWUSR); 
                file->setShareMode(IFSHnone); 
                break;
            case compatIFSHread:
                file->setShareMode(IFSHread); 
                break; 
            case compatIFSHwrite:
                file->setShareMode(IFSHfull); 
                break;
            case compatIFSHexec:
                file->setCreateFlags(S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH); 
                break;
            case compatIFSHall:
                file->setCreateFlags(S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH); // bit excessive
                file->setShareMode(IFSHfull); 
                break;
            }
            if (TF_TRACE_PRE_IO)
                PROGLOG("before open file '%s',  (%d,%d)",name->text.get(),(int)mode,(int)share);
            IFileIO *fileio = file->open((IFOmode)mode);
            int handle;
            if (fileio) {
                CriticalBlock block(sect);
                handle = getNextHandle();
                client.previdx = client.opennames.ordinality();
                client.handles.append(handle);
                client.openfiles.append(*fileio);
                client.opennames.append(*name.getLink());
            }
            else 
                handle = 0;
            reply.append(RFEnoerror);
            reply.append(handle);
            if (TF_TRACE)
                PROGLOG("open file '%s',  (%d,%d) handle = %d",name->text.get(),(int)mode,(int)share,handle);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_OpenFailed,e->errorCode(),s.str());
            e->Release();
        }
        return false;
    }


    bool cmdCloseFileIO(MemoryBuffer & msg, MemoryBuffer & reply)
    {
        int handle;
        msg.read(handle);
        IFileIO *fileio;
        if (!checkFileIOHandle(reply, handle, fileio, true))
            return false;
        if (TF_TRACE)
            PROGLOG("close file,  handle = %d",handle);
        reply.append(RFEnoerror);
        return true;
    }



    bool cmdRead(MemoryBuffer & msg, MemoryBuffer & reply)
    {
        int handle;
        __int64 pos;
        size32_t len;
        msg.read(handle).read(pos).read(len);
        IFileIO *fileio;
        if (!checkFileIOHandle(reply, handle, fileio))
            return false;

        //arrange it so we read directly into the reply buffer...
        unsigned posOfErr = reply.length();
        reply.append((unsigned)RFEnoerror);
        size32_t numRead;
        unsigned posOfLength = reply.length();
        if (TF_TRACE_PRE_IO)
            PROGLOG("before read file,  handle = %d, toread = %d",handle,len);
        void * data;
        {
            reply.reserve(sizeof(numRead));
            data = reply.reserve(len);
        }
        try {
            numRead = fileio->read(pos,len,data);
        }
        catch (IException *e)
        {
            reply.setWritePos(posOfErr);
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_ReadFailed,e->errorCode(),s.str());
            e->Release();
            return false;
        }
        if (TF_TRACE)
            PROGLOG("read file,  handle = %d, pos = %"I64F"d, toread = %d, read = %d",handle,pos,len,numRead);
        {
            reply.setLength(posOfLength + sizeof(numRead) + numRead);
            reply.writeEndianDirect(posOfLength,sizeof(numRead),&numRead);
        }
        return true;
    }


    bool cmdSize(MemoryBuffer & msg, MemoryBuffer & reply)
    {
        int handle;
        msg.read(handle);
        IFileIO *fileio;
        if (!checkFileIOHandle(reply, handle, fileio))
            return false;
        __int64 size = fileio->size();
        reply.append((unsigned)RFEnoerror).append(size);
        if (TF_TRACE)
            PROGLOG("size file,  handle = %d, size = %"I64F"d",handle,size);
        return true;
    }

    bool cmdSetSize(MemoryBuffer & msg, MemoryBuffer & reply)
    {
        int handle;
        offset_t size;
        msg.read(handle).read(size);
        IFileIO *fileio;
        if (TF_TRACE)
            PROGLOG("set size file,  handle = %d, size = %"I64F"d",handle,size);
        if (!checkFileIOHandle(reply, handle, fileio))
            return false;
        fileio->setSize(size);
        reply.append((unsigned)RFEnoerror);
        return true;
    }


    bool cmdWrite(MemoryBuffer & msg, MemoryBuffer & reply)
    {
        int handle;
        __int64 pos;
        size32_t len;
        msg.read(handle).read(pos).read(len);
        IFileIO *fileio;
        if (!checkFileIOHandle(reply, handle, fileio))
            return false;

        const byte *data = (const byte *)msg.readDirect(len);
        try {
            if (TF_TRACE_PRE_IO)
                PROGLOG("before write file,  handle = %d, towrite = %d",handle,len);
            size32_t numWritten = fileio->write(pos,len,data);
            if (TF_TRACE)
                PROGLOG("write file,  handle = %d, towrite = %d, written = %d",handle,len,numWritten);
            reply.append((unsigned)RFEnoerror).append(numWritten);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_WriteFailed,e->errorCode(),s.str());
            e->Release();
        }

        return false;
    }

    bool cmdExists(MemoryBuffer & msg, MemoryBuffer & reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        msg.read(name);
        if (TF_TRACE)
            PROGLOG("exists,  '%s'",name.get());
        Owned<IFile> file=createIFile(name);
        try {
            bool e = file->exists();
            reply.append((unsigned)RFEnoerror).append(e);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_ExistsFailed,e->errorCode(),s.str());
            e->Release();
        }

        return false;
    }


    bool cmdRemove(MemoryBuffer & msg, MemoryBuffer & reply,CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        msg.read(name);
        if (TF_TRACE)
            PROGLOG("remove,  '%s'",name.get());
        Owned<IFile> file=createIFile(name);
        try {
            bool e = file->remove();
            reply.append((unsigned)RFEnoerror).append(e);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_RemoveFailed,e->errorCode(),s.str());
            e->Release();
        }

        return false;
    }

    bool cmdGetVer(MemoryBuffer & msg, MemoryBuffer & reply)
    {
        if (TF_TRACE)
            PROGLOG("getVer");
        if (msg.getPos()+sizeof(unsigned)>msg.length())
            reply.append((unsigned)RFEnoerror);
        else
            reply.append((unsigned)FILESRV_VERSION+0x10000);
        reply.append(VERSTRING);
        return true;
    }

    bool cmdRename(MemoryBuffer & msg, MemoryBuffer & reply,CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr fromname;
        msg.read(fromname);
        StringAttr toname;
        msg.read(toname);
        if (TF_TRACE)
            PROGLOG("rename,  '%s' to '%s'",fromname.get(),toname.get());
        Owned<IFile> file=createIFile(fromname);
        try {
            file->rename(toname);
            reply.append((unsigned)RFEnoerror);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_RenameFailed,e->errorCode(),s.str());
            e->Release();
        }

        return false;
        
    }

    bool cmdMove(MemoryBuffer & msg, MemoryBuffer & reply,CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr fromname;
        msg.read(fromname);
        StringAttr toname;
        msg.read(toname);
        if (TF_TRACE)
            PROGLOG("move,  '%s' to '%s'",fromname.get(),toname.get());
        Owned<IFile> file=createIFile(fromname);
        try {
            file->move(toname);
            reply.append((unsigned)RFEnoerror);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_MoveFailed,e->errorCode(),s.str());
            e->Release();
        }

        return false;
        
    }

    bool cmdCopy(MemoryBuffer & msg, MemoryBuffer & reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr fromname;
        msg.read(fromname);
        StringAttr toname;
        msg.read(toname);
        if (TF_TRACE)
            PROGLOG("copy,  '%s' to '%s'",fromname.get(),toname.get());
        try {
            copyFile(toname, fromname);
            reply.append((unsigned)RFEnoerror);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_CopyFailed,e->errorCode(),s.str());
            e->Release();
        }

        return false;
        
    }

    bool cmdAppend(MemoryBuffer & msg, MemoryBuffer & reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        int handle;
        __int64 pos;
        __int64 len;
        StringAttr srcname;
        msg.read(handle).read(srcname).read(pos).read(len);
        IFileIO *fileio;
        if (!checkFileIOHandle(reply, handle, fileio))
            return false;

        try {
            Owned<IFile> file = createIFile(srcname.get());
            __int64 written = fileio->appendFile(file,pos,len);
            if (TF_TRACE)
                PROGLOG("append file,  handle = %d, file=%s, pos = %"I64F"d len = %"I64F"d written = %"I64F"d",handle,srcname.get(),pos,len,written);
            reply.append((unsigned)RFEnoerror).append(written);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_AppendFailed,e->errorCode(),s.str());
            e->Release();
        }

        return false;
        
    }

    bool cmdIsFile(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        msg.read(name);
        if (TF_TRACE)
            PROGLOG("isFile,  '%s'",name.get());
        Owned<IFile> file=createIFile(name);
        try {
            unsigned ret = (unsigned)file->isFile();
            reply.append((unsigned)RFEnoerror).append(ret);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_IsFileFailed,e->errorCode(),s.str());
            e->Release();
        }
        return false;
    }

    bool cmdIsDir(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        msg.read(name);
        if (TF_TRACE)
            PROGLOG("isDir,  '%s'",name.get());
        Owned<IFile> file=createIFile(name);
        try {
            unsigned ret = (unsigned)file->isDirectory();
            reply.append((unsigned)RFEnoerror).append(ret);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_IsDirectoryFailed,e->errorCode(),s.str());
            e->Release();
        }
        return false;
    }

    bool cmdIsReadOnly(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        msg.read(name);
        if (TF_TRACE)
            PROGLOG("isReadOnly,  '%s'",name.get());
        Owned<IFile> file=createIFile(name);
        try {
            unsigned ret = (unsigned)file->isReadOnly();
            reply.append((unsigned)RFEnoerror).append(ret);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_IsReadOnlyFailed,e->errorCode(),s.str());
            e->Release();
        }
        return false;
    }

    bool cmdSetReadOnly(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        bool set;
        msg.read(name).read(set);

        if (TF_TRACE)
            PROGLOG("setReadOnly,  '%s' %d",name.get(),(int)set);
        Owned<IFile> file=createIFile(name);
        try {
            file->setReadOnly(set);
            reply.append((unsigned)RFEnoerror);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_SetReadOnlyFailed,e->errorCode(),s.str());
            e->Release();
        }
        return false;
    }

    bool cmdGetTime(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        msg.read(name);
        if (TF_TRACE)
            PROGLOG("getTime,  '%s'",name.get());
        Owned<IFile> file=createIFile(name);
        CDateTime createTime;
        CDateTime modifiedTime;
        CDateTime accessedTime;
        try {
            bool ret = file->getTime(&createTime,&modifiedTime,&accessedTime);
            reply.append((unsigned)RFEnoerror).append(ret);
            if (ret) {
                createTime.serialize(reply);
                modifiedTime.serialize(reply);
                accessedTime.serialize(reply);
            }
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_GetTimeFailed,e->errorCode(),s.str());
            e->Release();
        }
        return false;
    }

    bool cmdSetTime(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        bool creategot;
        CDateTime createTime;
        bool modifiedgot;
        CDateTime modifiedTime;
        bool accessedgot;
        CDateTime accessedTime;
        msg.read(name);
        msg.read(creategot);
        if (creategot) 
            createTime.deserialize(msg);
        msg.read(modifiedgot);
        if (modifiedgot) 
            modifiedTime.deserialize(msg);
        msg.read(accessedgot);
        if (accessedgot) 
            accessedTime.deserialize(msg);

        if (TF_TRACE)
            PROGLOG("setTime,  '%s'",name.get());
        Owned<IFile> file=createIFile(name);

        try {
            bool ret = file->setTime(creategot?&createTime:NULL,modifiedgot?&modifiedTime:NULL,accessedgot?&accessedTime:NULL);
            reply.append((unsigned)RFEnoerror).append(ret);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_SetTimeFailed,e->errorCode(),s.str());
            e->Release();
        }
        return false;
    }

    bool cmdCreateDir(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        msg.read(name);
        if (TF_TRACE)
            PROGLOG("CreateDir,  '%s'",name.get());
        Owned<IFile> dir=createIFile(name);

        try {
            bool ret = dir->createDirectory();
            reply.append((unsigned)RFEnoerror).append(ret);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_CreateDirFailed,e->errorCode(),s.str());
            e->Release();
        }
        return false;
    }

    bool cmdGetDir(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        StringAttr mask;
        bool includedir;
        bool sub;
        byte stream = 0;
        msg.read(name).read(mask).read(includedir).read(sub);
        if (msg.remaining()>=sizeof(byte)) {
            msg.read(stream);
            if (stream==1)
                client.opendir.clear();
        }

        if (TF_TRACE)
            PROGLOG("GetDir,  '%s', '%s'",name.get(),mask.get());
        try {
            Owned<IFile> dir=createIFile(name);

            Owned<IDirectoryIterator> iter;
            if (stream>1) 
                iter.set(client.opendir);
            else {
                iter.setown(dir->directoryFiles(mask.length()?mask.get():NULL,sub,includedir));
                if (stream != 0)
                    client.opendir.set(iter);
            }
            if (!iter) {
                reply.append((unsigned)RFSERR_GetDirFailed);
                return false;
            }
            reply.append((unsigned)RFEnoerror);
            if (CRemoteDirectoryIterator::serialize(reply,iter,stream?0x100000:0,stream<2)) {
                if (stream != 0)
                    client.opendir.clear();
            }
            else {
                bool cont=true;
                reply.append(cont);
            }
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_GetDirFailed,e->errorCode(),s.str());
            e->Release();
        }
        return false;
    }

    bool cmdMonitorDir(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        StringAttr mask;
        bool includedir;
        bool sub;
        unsigned checkinterval;
        unsigned timeout;
        __int64 cancelid; // not yet used
        msg.read(name).read(mask).read(includedir).read(sub).read(checkinterval).read(timeout).read(cancelid);
        byte isprev;
        msg.read(isprev);
        Owned<IDirectoryIterator> prev;
        if (isprev==1) {
            SocketEndpoint ep;
            CRemoteDirectoryIterator *di = new CRemoteDirectoryIterator(ep,name);
            di->appendBuf(msg);
            prev.setown(di);
        }
        if (TF_TRACE)
            PROGLOG("MonitorDir,  '%s' '%s'",name.get(),mask.get());
        try {
            Owned<IFile> dir=createIFile(name);
            Owned<IDirectoryDifferenceIterator> iter=dir->monitorDirectory(prev,mask.length()?mask.get():NULL,sub,includedir,checkinterval,timeout);
            reply.append((unsigned)RFEnoerror);
            byte state = (iter.get()==NULL)?0:1;
            reply.append(state);
            if (state==1)
                CRemoteDirectoryIterator::serializeDiff(reply,iter);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_GetDirFailed,e->errorCode(),s.str());
            e->Release();
        }
        return false;
    }

    bool cmdCopySection(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr uuid;
        StringAttr fromFile;
        StringAttr toFile;
        offset_t toOfs;
        offset_t fromOfs;
        offset_t size;
        offset_t sizeDone=0;
        offset_t totalSize=(offset_t)-1;
        unsigned timeout;
        msg.read(uuid).read(fromFile).read(toFile).read(toOfs).read(fromOfs).read(size).read(timeout);
        try {
            AsyncCommandStatus status = asyncCommandManager.copySection(uuid,fromFile,toFile,toOfs,fromOfs,size,sizeDone,totalSize,timeout);
            reply.append((unsigned)RFEnoerror).append((unsigned)status).append(sizeDone).append(totalSize);
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_CopySectionFailed,e->errorCode(),s.str());
            e->Release();
        }
        return true;
    }

    bool cmdTreeCopy(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client, CThrottler *throttler, bool usetmp=false)
    {
        IMPERSONATE_USER(client);
        RemoteFilename src;
        src.deserialize(msg);
        RemoteFilename dst;
        dst.deserialize(msg);
        StringAttr net;
        StringAttr mask;
        msg.read(net).read(mask);
        try {
            IpAddress ip;
            treeCopyFile(src,dst,net,mask,ip,usetmp,throttler);
            unsigned status = 0;
            reply.append((unsigned)RFEnoerror).append((unsigned)status);
            ip.ipserialize(reply);
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_TreeCopyFailed,e->errorCode(),s.str());
            e->Release();
        }
        return true;
    }

    bool cmdTreeCopyTmp(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client, CThrottler *throttler)
    {
        return cmdTreeCopy(msg, reply, client, throttler, true);
    }


    bool cmdGetCRC(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        StringAttr name;
        msg.read(name);
        if (TF_TRACE)
            PROGLOG("getCRC,  '%s'",name.get());
        Owned<IFile> file=createIFile(name);
        try {
            unsigned ret = file->getCRC();
            reply.append((unsigned)RFEnoerror).append(ret);
            return true;
        }
        catch (IException *e)
        {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_GetCrcFailed,e->errorCode(),s.str());
            e->Release();
        }
        return false;
    }

    bool cmdStop(MemoryBuffer &msg, MemoryBuffer &reply)
    {
        PROGLOG("Abort request received");
        stopping = true;
        if (acceptsock) 
            acceptsock->cancel_accept();
        reply.append((unsigned)RFEnoerror);
        return false;
    }

    bool cmdExec(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        StringAttr cmdline;
        StringAttr workdir;
        bool sync;
        bool hasoutput;
        size32_t insize;
        MemoryAttr inbuf;
        msg.read(cmdline).read(workdir).read(sync).read(hasoutput).read(insize);
        if (insize) 
            msg.read(insize, inbuf.allocate(insize));
        Owned<IPipeProcess> pipe = createPipeProcess();
        int retcode=-1;
        HANDLE phandle=(HANDLE)0;
        MemoryBuffer outbuf;
        if (pipe->run("EXEC",cmdline,workdir,insize!=0,hasoutput)) {
            if (insize) {
                pipe->write(insize, inbuf.get());
                pipe->closeInput();
            }
            if (hasoutput) {
                byte buf[4096];
                loop {
                    size32_t read = pipe->read(sizeof(buf),buf);
                    if (!read)
                        break;
                    outbuf.append(read,buf);
                }
            }
            if (sync)
                retcode = pipe->wait();
            else {
                phandle = pipe->getProcessHandle(); 
                retcode = 0;
            }
        }
        size32_t outsz = outbuf.length();
        reply.append(retcode).append((unsigned)phandle).append(outsz);
        if (outsz)
            reply.append(outbuf);
        return true;
    }

    bool cmdSetTrace(MemoryBuffer &msg, MemoryBuffer &reply)
    {
        byte flags;
        msg.read(flags);
        int retcode=-1;
        if (flags!=255) {   // escape
            retcode = traceFlags;
            traceFlags = flags;
        }
        reply.append(retcode);
        return true;
    }

    bool cmdGetInfo(MemoryBuffer &msg, MemoryBuffer &reply)
    {
        StringBuffer retstr;
        int retcode = getInfo(retstr);
        reply.append(retcode).append(retstr.str());
        return true;
    }

    bool cmdFirewall(MemoryBuffer &msg, MemoryBuffer &reply)
    {
        // TBD
        StringBuffer retstr;
        int retcode = getInfo(retstr);
        reply.append(retcode).append(retstr.str());
        return true;
    }

    bool cmdExtractBlobElements(MemoryBuffer &msg, MemoryBuffer &reply, CRemoteClientHandler &client)
    {
        IMPERSONATE_USER(client);
        try {
            StringAttr prefix;
            StringAttr filename;
            msg.read(prefix).read(filename);
            RemoteFilename rfn;
            rfn.setLocalPath(filename);
            ExtractedBlobArray extracted;
            extractBlobElements(prefix, rfn, extracted);
            unsigned n = extracted.ordinality();
            reply.append((unsigned)RFEnoerror).append(n);
            for (unsigned i=0;i<n;i++)
                extracted.item(i).serialize(reply);
        }
        catch (IException *e) {
            StringBuffer s;
            e->errorMessage(s);
            throwErr3(RFSERR_ExtractBlobElementsFailed,e->errorCode(),s.str());
            e->Release();
        }
        return true;
    }

    bool cmdRedeploy(MemoryBuffer &msg, MemoryBuffer &reply)
    {
        return false; // TBD
    }

    bool cmdKill(MemoryBuffer & msg, MemoryBuffer & reply)
    {
        // TBD
        throwErr2(RFSERR_InvalidCommand,(unsigned)RFCkill);
        return false;
    }

    bool cmdUnknown(MemoryBuffer & msg, MemoryBuffer & reply,RemoteFileCommandType cmd)
    {
        throwErr2(RFSERR_InvalidCommand,(unsigned)cmd);
        return false;
    }

    bool cmdUnlock(MemoryBuffer & msg, MemoryBuffer & reply,CRemoteClientHandler &client)
    {
        // this is an attempt to authenticate when we haven't got authentication turned on
        StringBuffer s;
        client.peerName(s);
        if (TF_TRACE_CLIENT_STATS)
            PROGLOG("Connect from %s",s.str());
        throwErr2(RFSERR_InvalidCommand,(unsigned)RFCunlock);
        return false;
    }

    bool dispatchCommand(MemoryBuffer & msg, MemoryBuffer & reply, CRemoteClientHandler *client, CThrottler *throttler)
    {
        RemoteFileCommandType cmd;
        msg.read(cmd);
        bool ret = true;
        switch(cmd) {
            MAPCOMMAND(RFCcloseIO, cmdCloseFileIO);
            MAPCOMMANDCLIENT(RFCopenIO, cmdOpenFileIO, *client);
            MAPCOMMAND(RFCread, cmdRead);
            MAPCOMMAND(RFCsize, cmdSize);
            MAPCOMMAND(RFCwrite, cmdWrite);
            MAPCOMMANDCLIENT(RFCexists, cmdExists, *client);
            MAPCOMMANDCLIENT(RFCremove, cmdRemove, *client);
            MAPCOMMANDCLIENT(RFCrename, cmdRename, *client);
            MAPCOMMAND(RFCgetver, cmdGetVer);
            MAPCOMMANDCLIENT(RFCisfile, cmdIsFile, *client);
            MAPCOMMANDCLIENT(RFCisdirectory, cmdIsDir, *client);
            MAPCOMMANDCLIENT(RFCisreadonly, cmdIsReadOnly, *client);
            MAPCOMMANDCLIENT(RFCsetreadonly, cmdSetReadOnly, *client);
            MAPCOMMANDCLIENT(RFCgettime, cmdGetTime, *client);
            MAPCOMMANDCLIENT(RFCsettime, cmdSetTime, *client);
            MAPCOMMANDCLIENT(RFCcreatedir, cmdCreateDir, *client);
            MAPCOMMANDCLIENT(RFCgetdir, cmdGetDir, *client);
            MAPCOMMANDCLIENT(RFCmonitordir, cmdMonitorDir, *client);
            MAPCOMMAND(RFCstop, cmdStop);
            MAPCOMMANDCLIENT(RFCexec, cmdExec, *client);
            MAPCOMMANDCLIENT(RFCextractblobelements, cmdExtractBlobElements, *client);
            MAPCOMMAND(RFCkill, cmdKill);
            MAPCOMMAND(RFCredeploy, cmdRedeploy); // only Windows
            MAPCOMMANDCLIENT(RFCgetcrc, cmdGetCRC, *client);
            MAPCOMMANDCLIENT(RFCmove, cmdMove, *client);
            MAPCOMMANDCLIENT(RFCcopy, cmdCopy, *client);
            MAPCOMMANDCLIENT(RFCappend, cmdAppend, *client);
            MAPCOMMAND(RFCsetsize, cmdSetSize);
            MAPCOMMAND(RFCsettrace, cmdSetTrace);
            MAPCOMMAND(RFCgetinfo, cmdGetInfo);
            MAPCOMMAND(RFCfirewall, cmdFirewall);
            MAPCOMMANDCLIENT(RFCunlock, cmdUnlock, *client);
            MAPCOMMANDCLIENT(RFCcopysection, cmdCopySection, *client);
            MAPCOMMANDCLIENTTHROTTLER(RFCtreecopy, cmdTreeCopy, *client, throttler);
            MAPCOMMANDCLIENTTHROTTLER(RFCtreecopytmp, cmdTreeCopyTmp, *client, throttler);

        default:
            ret = cmdUnknown(msg,reply,cmd);
        }
        if (!ret) { // append error string
            if (reply.length()>=sizeof(unsigned)*2) {
                reply.reset();
                unsigned z;
                unsigned e;
                reply.read(z).read(e);
                StringBuffer err("ERR(");
                err.append(e).append(") ");
                if (client&&(client->peerName(err)))
                    err.append(" : ");
                if (e&&(reply.getPos()<reply.length())) {
                    StringAttr es;
                    reply.read(es);
                    err.append(" : ").append(es);
                }
                reply.reset();
                if (cmd!=RFCunlock)
                    PROGLOG("%s",err.str());    // supress authentication logging
                if (client)
                    client->logPrevHandle();
            }
        }
        return ret;
    }


    virtual IPooledThread *createNew()
    {
        return new cCommandProcessor();
    }


    void run(SocketEndpoint &listenep)
    {
        if (listenep.isNull())
            acceptsock.setown(ISocket::create(listenep.port));

        else {
            StringBuffer ips;
            listenep.getIpText(ips);
            acceptsock.setown(ISocket::create_ip(listenep.port,ips.str()));
        }
        selecthandler->start();
        loop {
            Owned<ISocket> sock;
            bool sockavail;
            try {
                sockavail = acceptsock->wait_read(1000*60*1)!=0;
#if 0
                if (!sockavail) {
                    JSocketStatistics stats;
                    getSocketStatistics(stats);
                    StringBuffer s;
                    getSocketStatisticsString(stats,s);
                    PROGLOG( "Socket statistics : \n%s\n",s.str());
                }
#endif
            }
            catch (IException *e) {
                EXCLOG(e,"CRemoteFileServer(1)");
                e->Release();
                // not sure what to do so just accept
                sockavail = true;
            }
            if (stopping)
                break;
            if (sockavail) {
                try {
                    sock.setown(acceptsock->accept(true));
                    if (!sock||stopping)
                        break;
                }
                catch (IException *e) {
                    EXCLOG(e,"CRemoteFileServer");
                    e->Release();
                    break;
                }
                runClient(sock.getClear());
            }
            else
                checkTimeout();
        }
        if (TF_TRACE_CLIENT_STATS)
            PROGLOG("CRemoteFileServer:run exiting");
        selecthandler->stop(true);
    }

    void processUnauthenticatedCommand(RemoteFileCommandType typ,ISocket *socket, MemoryBuffer &msg)
    {
        // these are unauthenticated commands
        switch (typ) {
        case RFCgetver: break;
        default:
            typ = RFCinvalid;
            msg.writeDirect(msg.getPos()-sizeof(RemoteFileCommandType),sizeof(RemoteFileCommandType),&typ);
        }
        MemoryBuffer reply;
        dispatchCommand(msg, initSendBuffer(reply), NULL, NULL);
        sendBuffer(socket, reply);
    }

    bool checkAuthentication(ISocket *socket, IAuthenticatedUser *&ret)
    {
        ret = NULL;
        if (!AuthenticationEnabled)
            return true;
        MemoryBuffer reqbuf;
        MemoryBuffer reply;
        MemoryBuffer encbuf; // because aesEncrypt clears input
        initSendBuffer(reply);
        receiveBuffer(socket, reqbuf, 1);
        RemoteFileCommandType typ=0;
        if (reqbuf.remaining()<sizeof(RemoteFileCommandType))
            return false;
        reqbuf.read(typ);
        if (typ!=RFCunlock) {
            processUnauthenticatedCommand(typ,socket,reqbuf);
            return false;
        }
        if (reqbuf.remaining()<sizeof(OnceKey))
            return false;
        OnceKey oncekey;
        reqbuf.read(sizeof(oncekey),&oncekey);
        IpAddress ip;
        socket->getPeerAddress(ip);
        byte ipdata[16];
        size32_t ipds = ip.getNetAddress(sizeof(ipdata),&ipdata);
        mergeOnce(oncekey,sizeof(ipdata),&ipdata); // this is clients key
        OnceKey mykey;
        genOnce(mykey);
        reply.append((unsigned)0); // errcode
        aesEncrypt(&oncekey,sizeof(oncekey),&mykey,sizeof(oncekey),encbuf);
        reply.append(encbuf.length()).append(encbuf);
        sendBuffer(socket, reply); // send my oncekey
        reqbuf.clear();
        receiveBuffer(socket, reqbuf, 1);
        if (reqbuf.remaining()>sizeof(RemoteFileCommandType)+sizeof(size32_t)) {
            reqbuf.read(typ);
            if (typ==RFCunlockreply) {
                size32_t bs;
                reqbuf.read(bs);
                if (bs<=reqbuf.remaining()) {
                    MemoryBuffer userbuf;
                    aesDecrypt(&mykey,sizeof(mykey),reqbuf.readDirect(bs),bs,userbuf);
                    byte n;
                    userbuf.read(n);
                    if (n>=2) {
                        StringAttr user;
                        StringAttr password;
                        userbuf.read(user).read(password);
                        Owned<IAuthenticatedUser> iau = createAuthenticatedUser();
                        if (iau->login(user,password)) {
                            initSendBuffer(reply.clear());
                            reply.append((unsigned)0);
                            sendBuffer(socket, reply); // send OK
                            ret = iau;
                            return true;
                        }
                    }
                }
            }
        }
        reply.clear();
        throwErr(RFSERR_AuthenticateFailed);
        sendBuffer(socket, reply); // send OK
        return false;       
    }

    void runClient(ISocket *sock)
    {
        cCommandProcessor::cCommandProcessorParams params;
        IAuthenticatedUser *user=NULL;
        bool authenticated = false;
        try {
            if (checkAuthentication(sock,user)) 
                authenticated = true;
        }
        catch (IException *e) {
            e->Release();
        }
        if (!authenticated) {
            try {
                sock->Release();
            }
            catch (IException *e) {
                e->Release();
            }
            return;
        }
        params.client = new CRemoteClientHandler(this,sock,user,globallasttick);
        {
            CriticalBlock block(sect);
            params.client->Link();
            clients.append(*params.client);
        }
        threads->start(&params);
    }

    void stop()
    {
        // stop accept loop
        if (TF_TRACE_CLIENT_STATS)
            PROGLOG("CRemoteFileServer::stop");
        if (acceptsock) 
            acceptsock->cancel_accept();
        threads->stopAll();
        threads->joinAll(true,60*1000);
    }

    bool notify(CRemoteClientHandler *_client)
    {
        Linked<CRemoteClientHandler> client;
        client.set(_client);
        if (TF_TRACE_FULL)
            PROGLOG("notify %d",client->buf.length());
        if (client->buf.length()) {
            cCommandProcessor::cCommandProcessorParams params;
            params.client = client.getClear();
            threads->start(&params);
        }
        else 
            onCloseSocket(client,3);    // removes owned handles
        
        return false;
    }

    void addClient(CRemoteClientHandler *client)
    {
        if (client&&client->socket)
            selecthandler->add(client->socket,SELECTMODE_READ,client);
    }

    void checkTimeout()
    {
        if (msTick()-clientcounttick>1000*60*60) {
            CriticalBlock block(ClientCountSect);
            if (TF_TRACE_CLIENT_STATS && (ClientCount || MaxClientCount))
                PROGLOG("Client count = %d, max = %d", ClientCount, MaxClientCount);
            clientcounttick = msTick();
            MaxClientCount = ClientCount;
            if (closedclients) {
                if (TF_TRACE_CLIENT_STATS)
                    PROGLOG("Closed client count = %d",closedclients);
                closedclients = 0;
            }
        }
        CriticalBlock block(sect);
        ForEachItemInRev(i,clients) {
            CRemoteClientHandler &client = clients.item(i);
            if (client.timedOut()) {
                StringBuffer s;
                bool ok = client.getInfo(s);    // will spot duff sockets
                if (ok&&(client.handles.ordinality()!=0))  {
                    if (TF_TRACE_CLIENT_CONN) 
                        WARNLOG("Inactive %s",s.str());
                }
                else {
#ifndef _DEBUG
                    if (TF_TRACE_CLIENT_CONN) 
#endif
                        PROGLOG("Timing out %s",s.str());
                    closedclients++;
                    onCloseSocket(&client,4);   // removes owned handles
                }
            }
        }
    }

    int getInfo(StringBuffer &str)
    {
        {
            CriticalBlock block(ClientCountSect);
            str.append(VERSTRING).append('\n');
            str.appendf("Client count = %d\n",ClientCount);
            str.appendf("Max client count = %d",MaxClientCount);
        }
        CriticalBlock block(sect);
        ForEachItemIn(i,clients) {
            str.append('\n').append(i).append(": ");
            clients.item(i).getInfo(str);
        }
        return 0;
    }

    unsigned threadRunningCount()
    {
        if (!threads)
            return 0;
        return threads->runningCount();
    }

    Semaphore &throttleSem()
    {
        return throttlesem;
    }

    unsigned idleTime()
    {
        unsigned t = (unsigned)atomic_read(&globallasttick);
        return msTick()-t;
    }

};



IRemoteFileServer * createRemoteFileServer()
{
#if SIMULATE_PACKETLOSS
    errorSimulationOn = false;
#endif
    return new CRemoteFileServer();
}