lib/9p.js - emulators/v86 - Rivoreo Source Code Repositories

 // -------------------------------------------------
 // --------------------- 9P ------------------------
 // -------------------------------------------------
 // Implementation of the 9p filesystem device following the
 // 9P2000.L protocol ( https://code.google.com/p/diod/wiki/protocol )

 "use strict";

 // TODO
 // flush
 // lock?
 // correct hard links

 var EPERM = 1;       /* Operation not permitted */
 var ENOENT = 2;      /* No such file or directory */
 var EINVAL = 22;     /* Invalid argument */
 var ENOTSUPP = 524;  /* Operation is not supported */
 var ENOTEMPTY = 39;  /* Directory not empty */
 var EPROTO    = 71   /* Protocol error */

 var P9_SETATTR_MODE = 0x00000001;
 var P9_SETATTR_UID = 0x00000002;
 var P9_SETATTR_GID = 0x00000004;
 var P9_SETATTR_SIZE = 0x00000008;
 var P9_SETATTR_ATIME = 0x00000010;
 var P9_SETATTR_MTIME = 0x00000020;
 var P9_SETATTR_CTIME = 0x00000040;
 var P9_SETATTR_ATIME_SET = 0x00000080;
 var P9_SETATTR_MTIME_SET = 0x00000100;

 var P9_STAT_MODE_DIR = 0x80000000;
 var P9_STAT_MODE_APPEND = 0x40000000;
 var P9_STAT_MODE_EXCL = 0x20000000;
 var P9_STAT_MODE_MOUNT = 0x10000000;
 var P9_STAT_MODE_AUTH = 0x08000000;
 var P9_STAT_MODE_TMP = 0x04000000;
 var P9_STAT_MODE_SYMLINK = 0x02000000;
 var P9_STAT_MODE_LINK = 0x01000000;
 var P9_STAT_MODE_DEVICE = 0x00800000;
 var P9_STAT_MODE_NAMED_PIPE = 0x00200000;
 var P9_STAT_MODE_SOCKET = 0x00100000;
 var P9_STAT_MODE_SETUID = 0x00080000;
 var P9_STAT_MODE_SETGID = 0x00040000;
 var P9_STAT_MODE_SETVTX = 0x00010000;

 var FID_NONE = -1;
 var FID_INODE = 1;
 var FID_XATTR = 2;

 /**
  * @constructor
  *
  * @param {FS} filesystem
  */
 function Virtio9p(filesystem, bus) {
     /** @const @type {FS} */
     this.fs = filesystem;

     /** @const @type {BusConnector} */
     this.bus = bus;

     this.SendReply = function(x) {};
     this.deviceid = 0x9; // 9p filesystem
     this.hostfeature = 0x1; // mountpoint
     //this.configspace = [0x0, 0x4, 0x68, 0x6F, 0x73, 0x74]; // length of string and "host" string
     //this.configspace = [0x0, 0x9, 0x2F, 0x64, 0x65, 0x76, 0x2F, 0x72, 0x6F, 0x6F, 0x74 ]; // length of string and "/dev/root" string

     this.configspace = new Uint8Array([0x6, 0x0, 0x68, 0x6F, 0x73, 0x74, 0x39, 0x70]); // length of string and "host9p" string
     this.VERSION = "9P2000.L";
     this.BLOCKSIZE = 8192; // Let's define one page.
     this.msize = 8192; // maximum message size
     this.replybuffer = new Uint8Array(this.msize*2); // Twice the msize to stay on the safe site
     this.replybuffersize = 0;

     this.fids = [];
 }

 Virtio9p.prototype.get_state = function()
 {
     var state = [];

     state[0] = this.deviceid;
     state[1] = this.hostfeature;
     state[2] = this.configspace;
     state[3] = this.VERSION;
     state[4] = this.BLOCKSIZE;
     state[5] = this.msize;
     state[6] = this.replybuffer;
     state[7] = this.replybuffersize;
     state[8] = this.fids.map(function(f) { return [f.inodeid, f.type, f.uid] });

     return state;
 };

 Virtio9p.prototype.set_state = function(state)
 {
     this.deviceid = state[0];
     this.hostfeature = state[1];
     this.configspace = state[2];
     this.VERSION = state[3];
     this.BLOCKSIZE = state[4];
     this.msize = state[5];
     this.replybuffer = state[6];
     this.replybuffersize = state[7];
     this.fids = state[8].map(function(f) { return { inodeid: f[0], type: f[1], uid: f[2] } });
 };

 Virtio9p.prototype.Createfid = function(inode, type, uid) {
     return {inodeid: inode, type: type, uid: uid};
 }

 Virtio9p.prototype.Reset = function() {
     this.fids = [];
 }

 Virtio9p.prototype.BuildReply = function(id, tag, payloadsize) {
     Marshall(["w", "b", "h"], [payloadsize+7, id+1, tag], this.replybuffer, 0);
     if ((payloadsize+7) >= this.replybuffer.length) {
         DebugMessage("Error in 9p: payloadsize exceeds maximum length");
     }
     //for(var i=0; i<payload.length; i++)
     //    this.replybuffer[7+i] = payload[i];
     this.replybuffersize = payloadsize+7;
     return;
 }

 Virtio9p.prototype.SendError = function (tag, errormsg, errorcode) {
     //var size = Marshall(["s", "w"], [errormsg, errorcode], this.replybuffer, 7);
     var size = Marshall(["w"], [errorcode], this.replybuffer, 7);
     this.BuildReply(6, tag, size);
 }

 Virtio9p.prototype.ReceiveRequest = function (index, GetByte) {
     var header = Unmarshall2(["w", "b", "h"], GetByte);
     //var size = header[0];
     var id = header[1];
     var tag = header[2];
     //DebugMessage("size:" + size + " id:" + id + " tag:" + tag);

     switch(id)
     {
         case 8: // statfs
             var size = this.fs.GetTotalSize(); // size used by all files
             var space = this.fs.GetSpace();
             var req = [];
             req[0] = 0x01021997;
             req[1] = this.BLOCKSIZE; // optimal transfer block size
             req[2] = Math.floor(space/req[1]); // free blocks, let's say 1GB
             req[3] = req[2] - Math.floor(size/req[1]); // free blocks in fs
             req[4] = req[2] - Math.floor(size/req[1]); // free blocks avail to non-superuser
             req[5] = this.fs.inodes.length; // total number of inodes
             req[6] = 1024*1024;
             req[7] = 0; // file system id?
             req[8] = 256; // maximum length of filenames

             size = Marshall(["w", "w", "d", "d", "d", "d", "d", "d", "w"], req, this.replybuffer, 7);
             this.BuildReply(id, tag, size);
             this.SendReply(index);
             break;

         case 112: // topen
         case 12: // tlopen
             var req = Unmarshall2(["w", "w"], GetByte);
             var fid = req[0];
             var mode = req[1];
             DebugMessage("[open] fid=" + fid + ", mode=" + mode);
             var inode = this.fs.GetInode(this.fids[fid].inodeid);
             req[0] = inode.qid;
             req[1] = this.msize - 24;
             Marshall(["Q", "w"], req, this.replybuffer, 7);
             this.BuildReply(id, tag, 13+4);
             DebugMessage("file open " + inode.name);
             //if (inode.status == STATUS_LOADING) return;
             var ret = this.fs.OpenInode(this.fids[fid].inodeid, mode);
             this.fs.AddEvent(this.fids[fid].inodeid,
                 function() {
                     DebugMessage("file opened " + inode.name + " tag:"+tag);
                     req[0] = inode.qid;
                     req[1] = this.msize - 24;
                     Marshall(["Q", "w"], req, this.replybuffer, 7);
                     this.BuildReply(id, tag, 13+4);
                     this.SendReply(index);
                 }.bind(this)
             );
             break;

         case 70: // link (just copying)
             var req = Unmarshall2(["w", "w", "s"], GetByte);
             var dfid = req[0];
             var fid = req[1];
             var name = req[2];
             DebugMessage("[link] dfid=" + dfid + ", name=" + name);
             var inode = this.fs.CreateInode();
             var inodetarget = this.fs.GetInode(this.fids[fid].inodeid);
             var targetdata = this.fs.inodedata[this.fids[fid].inodeid];
             //inode = inodetarget;
             inode.mode = inodetarget.mode;
             inode.size = inodetarget.size;
             inode.symlink = inodetarget.symlink;
             var data = this.fs.inodedata[this.fs.inodes.length] = new Uint8Array(inode.size);
             //inode.waswritten = true;
             for(var i=0; i<inode.size; i++) {
                 data[i] = targetdata[i];
             }
             inode.name = name;
             inode.parentid = this.fids[dfid].inodeid;
             this.fs.PushInode(inode);

             //inode.uid = inodetarget.uid;
             //inode.gid = inodetarget.gid;
             //inode.mode = inodetarget.mode | S_IFLNK;
             this.BuildReply(id, tag, 0);
             this.SendReply(index);
             break;

         case 16: // symlink
             var req = Unmarshall2(["w", "s", "s", "w"], GetByte);
             var fid = req[0];
             var name = req[1];
             var symgt = req[2];
             var gid = req[3];
             DebugMessage("[symlink] fid=" + fid + ", name=" + name + ", symgt=" + symgt + ", gid=" + gid);
             var idx = this.fs.CreateSymlink(name, this.fids[fid].inodeid, symgt);
             var inode = this.fs.GetInode(idx);
             inode.uid = this.fids[fid].uid;
             inode.gid = gid;
             Marshall(["Q"], [inode.qid], this.replybuffer, 7);
             this.BuildReply(id, tag, 13);
             this.SendReply(index);
             break;

         case 18: // mknod
             var req = Unmarshall2(["w", "s", "w", "w", "w", "w"], GetByte);
             var fid = req[0];
             var name = req[1];
             var mode = req[2];
             var major = req[3];
             var minor = req[4];
             var gid = req[5];
             DebugMessage("[mknod] fid=" + fid + ", name=" + name + ", major=" + major + ", minor=" + minor+ "");
             var idx = this.fs.CreateNode(name, this.fids[fid].inodeid, major, minor);
             var inode = this.fs.GetInode(idx);
             inode.mode = mode;
             inode.uid = this.fids[fid].uid;
             inode.gid = gid;
             Marshall(["Q"], [inode.qid], this.replybuffer, 7);
             this.BuildReply(id, tag, 13);
             this.SendReply(index);
             break;


         case 22: // TREADLINK
             var req = Unmarshall2(["w"], GetByte);
             var fid = req[0];
             DebugMessage("[readlink] fid=" + fid);
             var inode = this.fs.GetInode(this.fids[fid].inodeid);
             var size = Marshall(["s"], [inode.symlink], this.replybuffer, 7);
             this.BuildReply(id, tag, size);
             this.SendReply(index);
             break;


         case 72: // tmkdir
             var req = Unmarshall2(["w", "s", "w", "w"], GetByte);
             var fid = req[0];
             var name = req[1];
             var mode = req[2];
             var gid = req[3];
             DebugMessage("[mkdir] fid=" + fid + ", name=" + name + ", mode=" + mode + ", gid=" + gid);
             var idx = this.fs.CreateDirectory(name, this.fids[fid].inodeid);
             var inode = this.fs.GetInode(idx);
             inode.mode = mode | S_IFDIR;
             inode.uid = this.fids[fid].uid;
             inode.gid = gid;
             Marshall(["Q"], [inode.qid], this.replybuffer, 7);
             this.BuildReply(id, tag, 13);
             this.SendReply(index);
             break;

         case 14: // tlcreate
             var req = Unmarshall2(["w", "s", "w", "w", "w"], GetByte);
             var fid = req[0];
             var name = req[1];
             var flags = req[2];
             var mode = req[3];
             var gid = req[4];
             DebugMessage("[create] fid=" + fid + ", name=" + name + ", flags=" + flags + ", mode=" + mode + ", gid=" + gid);
             var idx = this.fs.CreateFile(name, this.fids[fid].inodeid);
             this.fids[fid].inodeid = idx;
             this.fids[fid].type = FID_INODE;
             var inode = this.fs.GetInode(idx);
             inode.uid = this.fids[fid].uid;
             inode.gid = gid;
             inode.mode = mode;
             Marshall(["Q", "w"], [inode.qid, this.msize - 24], this.replybuffer, 7);
             this.BuildReply(id, tag, 13+4);
             this.SendReply(index);
             break;

         case 52: // lock always suceed
             DebugMessage("lock file\n");
             Marshall(["w"], [0], this.replybuffer, 7);
             this.BuildReply(id, tag, 1);
             this.SendReply(index);
             break;

         /*
         case 54: // getlock
             break;
         */

         case 24: // getattr
             var req = Unmarshall2(["w", "d"], GetByte);
             var fid = req[0];
             var inode = this.fs.GetInode(this.fids[fid].inodeid);
             DebugMessage("[getattr]: fid=" + fid + " name=" + inode.name + " request mask=" + req[1]);
             req[0] |= 0x1000; // P9_STATS_GEN

             req[0] = req[1]; // request mask
             req[1] = inode.qid;

             req[2] = inode.mode;
             req[3] = inode.uid; // user id
             req[4] = inode.gid; // group id

             req[5] = 0x1; // number of hard links
             req[6] = (inode.major<<8) | (inode.minor); // device id low
             req[7] = inode.size; // size low
             req[8] = this.BLOCKSIZE;
             req[9] = Math.floor(inode.size/512+1);; // blk size low
             req[10] = inode.atime; // atime
             req[11] = 0x0;
             req[12] = inode.mtime; // mtime
             req[13] = 0x0;
             req[14] = inode.ctime; // ctime
             req[15] = 0x0;
             req[16] = 0x0; // btime
             req[17] = 0x0;
             req[18] = 0x0; // st_gen
             req[19] = 0x0; // data_version
             Marshall([
             "d", "Q",
             "w",
             "w", "w",
             "d", "d",
             "d", "d", "d",
             "d", "d", // atime
             "d", "d", // mtime
             "d", "d", // ctime
             "d", "d", // btime
             "d", "d",
             ], req, this.replybuffer, 7);
             this.BuildReply(id, tag, 8 + 13 + 4 + 4+ 4 + 8*15);
             this.SendReply(index);
             break;

         case 26: // setattr
             var req = Unmarshall2(["w", "w",
                 "w", // mode
                 "w", "w", // uid, gid
                 "d", // size
                 "d", "d", // atime
                 "d", "d"] // mtime
             , GetByte);
             var fid = req[0];
             var inode = this.fs.GetInode(this.fids[fid].inodeid);
             DebugMessage("[setattr]: fid=" + fid + " request mask=" + req[1] + " name=" +inode.name);
             if (req[1] & P9_SETATTR_MODE) {
                 inode.mode = req[2];
             }
             if (req[1] & P9_SETATTR_UID) {
                 inode.uid = req[3];
             }
             if (req[1] & P9_SETATTR_GID) {
                 inode.gid = req[4];
             }
             if (req[1] & P9_SETATTR_ATIME_SET) {
                 inode.atime = req[6];
             }
             if (req[1] & P9_SETATTR_MTIME_SET) {
                 inode.atime = req[8];
             }
             if (req[1] & P9_SETATTR_ATIME) {
                 inode.atime = Math.floor((new Date()).getTime()/1000);
             }
             if (req[1] & P9_SETATTR_MTIME) {
                 inode.mtime = Math.floor((new Date()).getTime()/1000);
             }
             if (req[1] & P9_SETATTR_CTIME) {
                 inode.ctime = Math.floor((new Date()).getTime()/1000);
             }
             if (req[1] & P9_SETATTR_SIZE) {
                 this.fs.ChangeSize(this.fids[fid].inodeid, req[5]);
             }
             this.BuildReply(id, tag, 0);
             this.SendReply(index);
             break;

         case 50: // fsync
             var req = Unmarshall2(["w", "d"], GetByte);
             var fid = req[0];
             this.BuildReply(id, tag, 0);
             this.SendReply(index);
             break;

         case 40: // TREADDIR
         case 116: // read
             var req = Unmarshall2(["w", "d", "w"], GetByte);
             var fid = req[0];
             var offset = req[1];
             var count = req[2];
             var inode = this.fs.GetInode(this.fids[fid].inodeid);
             if (id == 40) DebugMessage("[treaddir]: fid=" + fid + " offset=" + offset + " count=" + count);
             if (id == 116) DebugMessage("[read]: fid=" + fid + " (" + inode.name + ") offset=" + offset + " count=" + count + " fidtype=" + this.fids[fid].type);
             if (this.fids[fid].type == FID_XATTR) {
                 if (inode.caps.length < offset+count) count = inode.caps.length - offset;
                 for(var i=0; i<count; i++)
                     this.replybuffer[7+4+i] = inode.caps[offset+i];
                 Marshall(["w"], [count], this.replybuffer, 7);
                 this.BuildReply(id, tag, 4 + count);
                 this.SendReply(index);
             } else {
                 var file = this.fs.inodes[this.fids[fid].inodeid];
                 this.bus.send("9p-read-start");

                 this.fs.OpenInode(this.fids[fid].inodeid, undefined);
                 this.fs.AddEvent(this.fids[fid].inodeid,
                     function() {
                         this.bus.send("9p-read-end", [file.name, count]);

                         if (inode.size < offset+count) count = inode.size - offset;
                         var data = this.fs.inodedata[this.fids[fid].inodeid];
                         if(data) {
                             for(var i=0; i<count; i++)
                                 this.replybuffer[7+4+i] = data[offset+i];
                         }
                         Marshall(["w"], [count], this.replybuffer, 7);
                         this.BuildReply(id, tag, 4 + count);
                         this.SendReply(index);
                     }.bind(this)
                 );
             }
             break;

         case 118: // write
             var req = Unmarshall2(["w", "d", "w"], GetByte);
             var fid = req[0];
             var offset = req[1];
             var count = req[2];
             DebugMessage("[write]: fid=" + fid + " (" + this.fs.inodes[this.fids[fid].inodeid].name + ") offset=" + offset + " count=" + count);
             this.fs.Write(this.fids[fid].inodeid, offset, count, GetByte);

             var file = this.fs.inodes[this.fids[fid].inodeid];
             this.bus.send("9p-write-end", [file.name, count]);

             Marshall(["w"], [count], this.replybuffer, 7);
             this.BuildReply(id, tag, 4);
             this.SendReply(index);
             break;

         case 74: // RENAMEAT
             var req = Unmarshall2(["w", "s", "w", "s"], GetByte);
             var olddirfid = req[0];
             var oldname = req[1];
             var newdirfid = req[2];
             var newname = req[3];
             DebugMessage("[renameat]: oldname=" + oldname + " newname=" + newname);
             var ret = this.fs.Rename(this.fids[olddirfid].inodeid, oldname, this.fids[newdirfid].inodeid, newname);
             if (ret == false) {
                 this.SendError(tag, "No such file or directory", ENOENT);
                 this.SendReply(index);
                 break;
             }
             this.BuildReply(id, tag, 0);
             this.SendReply(index);
             break;

         case 76: // TUNLINKAT
             var req = Unmarshall2(["w", "s", "w"], GetByte);
             var dirfd = req[0];
             var name = req[1];
             var flags = req[2];
             DebugMessage("[unlink]: dirfd=" + dirfd + " name=" + name + " flags=" + flags);
             var fid = this.fs.Search(this.fids[dirfd].inodeid, name);
             if (fid == -1) {
                    this.SendError(tag, "No such file or directory", ENOENT);
                    this.SendReply(index);
                    break;
             }
             var ret = this.fs.Unlink(fid);
             if (!ret) {
                 this.SendError(tag, "Directory not empty", ENOTEMPTY);
                 this.SendReply(index);
                 break;
             }
             this.BuildReply(fid, tag, 0);
             this.SendReply(index);
             break;

         case 100: // version
             var version = Unmarshall2(["w", "s"], GetByte);
             DebugMessage("[version]: msize=" + version[0] + " version=" + version[1]);
             this.msize = version[0];
             var size = Marshall(["w", "s"], [this.msize, this.VERSION], this.replybuffer, 7);
             this.BuildReply(id, tag, size);
             this.SendReply(index);
             break;

         case 104: // attach
             // return root directorie's QID
             var req = Unmarshall2(["w", "w", "s", "s", "w"], GetByte);
             var fid = req[0];
             var uid = req[4];
             DebugMessage("[attach]: fid=" + fid + " afid=" + hex8(req[1]) + " uname=" + req[2] + " aname=" + req[3]);
             this.fids[fid] = this.Createfid(0, FID_INODE, uid);
             var inode = this.fs.GetInode(this.fids[fid].inodeid);
             Marshall(["Q"], [inode.qid], this.replybuffer, 7);
             this.BuildReply(id, tag, 13);
             this.SendReply(index);
             break;

         case 108: // tflush
             var req = Unmarshall2(["h"], GetByte);
             var oldtag = req[0];
             DebugMessage("[flush] " + tag);
             //Marshall(["Q"], [inode.qid], this.replybuffer, 7);
             this.BuildReply(id, tag, 0);
             this.SendReply(index);
             break;


         case 110: // walk
             var req = Unmarshall2(["w", "w", "h"], GetByte);
             var fid = req[0];
             var nwfid = req[1];
             var nwname = req[2];
             DebugMessage("[walk]: fid=" + req[0] + " nwfid=" + req[1] + " nwname=" + nwname);
             if (nwname == 0) {
                 this.fids[nwfid] = this.Createfid(this.fids[fid].inodeid, FID_INODE, this.fids[fid].uid);
                 //this.fids[nwfid].inodeid = this.fids[fid].inodeid;
                 Marshall(["h"], [0], this.replybuffer, 7);
                 this.BuildReply(id, tag, 2);
                 this.SendReply(index);
                 break;
             }
             var wnames = [];
             for(var i=0; i<nwname; i++) {
                 wnames.push("s");
             }
             var walk = Unmarshall2(wnames, GetByte);
             var idx = this.fids[fid].inodeid;
             var offset = 7+2;
             var nwidx = 0;
             //console.log(idx, this.fs.inodes[idx]);
             DebugMessage("walk in dir " + this.fs.inodes[idx].name  + " to: " + walk.toString());
             for(var i=0; i<nwname; i++) {
                 idx = this.fs.Search(idx, walk[i]);

                 if (idx == -1) {
                    DebugMessage("Could not find: " + walk[i]);
                    break;
                 }
                 offset += Marshall(["Q"], [this.fs.inodes[idx].qid], this.replybuffer, offset);
                 nwidx++;
                 //DebugMessage(this.fids[nwfid].inodeid);
                 //this.fids[nwfid].inodeid = idx;
                 //this.fids[nwfid].type = FID_INODE;
                 this.fids[nwfid] = this.Createfid(idx, FID_INODE, this.fids[fid].uid);
             }
             Marshall(["h"], [nwidx], this.replybuffer, 7);
             this.BuildReply(id, tag, offset-7);
             this.SendReply(index);
             break;

         case 120: // clunk
             var req = Unmarshall2(["w"], GetByte);
             DebugMessage("[clunk]: fid=" + req[0]);
             if (this.fids[req[0]] && this.fids[req[0]].inodeid >=  0) {
                 this.fs.CloseInode(this.fids[req[0]].inodeid);
                 this.fids[req[0]].inodeid = -1;
                 this.fids[req[0]].type = FID_NONE;
             }
             this.BuildReply(id, tag, 0);
             this.SendReply(index);
             break;

         case 32:
             this.SendError(tag, "Operation i not supported",  ENOTSUPP);
             this.SendReply(index);
             break;

         case 30: // xattrwalk
             var req = Unmarshall2(["w", "w", "s"], GetByte);
             var fid = req[0];
             var newfid = req[1];
             var name = req[2];
             DebugMessage("[xattrwalk]: fid=" + req[0] + " newfid=" + req[1] + " name=" + req[2]);
             this.fids[newfid] = this.Createfid(this.fids[fid].inodeid, FID_NONE, this.fids[fid].uid);
             //this.fids[newfid].inodeid = this.fids[fid].inodeid;
             //this.fids[newfid].type = FID_NONE;
             var length = 0;
             if (name == "security.capability") {
                 length = this.fs.PrepareCAPs(this.fids[fid].inodeid);
                 this.fids[newfid].type = FID_XATTR;
             }
             Marshall(["d"], [length], this.replybuffer, 7);
             this.BuildReply(id, tag, 8);
             this.SendReply(index);
             break;

         default:
             DebugMessage("Error in Virtio9p: Unknown id " + id + " received");
             abort();
             //this.SendError(tag, "Operation i not supported",  ENOTSUPP);
             //this.SendReply(index);
             break;
     }

     //consistency checks if there are problems with the filesystem
     //this.fs.Check();
 }
	// -------------------------------------------------
	// --------------------- 9P ------------------------
	// -------------------------------------------------
	// Implementation of the 9p filesystem device following the
	// 9P2000.L protocol ( https://code.google.com/p/diod/wiki/protocol )

	"use strict";

	// TODO
	// flush
	// lock?
	// correct hard links

	var EPERM = 1; /* Operation not permitted */
	var ENOENT = 2; /* No such file or directory */
	var EINVAL = 22; /* Invalid argument */
	var ENOTSUPP = 524; /* Operation is not supported */
	var ENOTEMPTY = 39; /* Directory not empty */
	var EPROTO = 71 /* Protocol error */

	var P9_SETATTR_MODE = 0x00000001;
	var P9_SETATTR_UID = 0x00000002;
	var P9_SETATTR_GID = 0x00000004;
	var P9_SETATTR_SIZE = 0x00000008;
	var P9_SETATTR_ATIME = 0x00000010;
	var P9_SETATTR_MTIME = 0x00000020;
	var P9_SETATTR_CTIME = 0x00000040;
	var P9_SETATTR_ATIME_SET = 0x00000080;
	var P9_SETATTR_MTIME_SET = 0x00000100;

	var P9_STAT_MODE_DIR = 0x80000000;
	var P9_STAT_MODE_APPEND = 0x40000000;
	var P9_STAT_MODE_EXCL = 0x20000000;
	var P9_STAT_MODE_MOUNT = 0x10000000;
	var P9_STAT_MODE_AUTH = 0x08000000;
	var P9_STAT_MODE_TMP = 0x04000000;
	var P9_STAT_MODE_SYMLINK = 0x02000000;
	var P9_STAT_MODE_LINK = 0x01000000;
	var P9_STAT_MODE_DEVICE = 0x00800000;
	var P9_STAT_MODE_NAMED_PIPE = 0x00200000;
	var P9_STAT_MODE_SOCKET = 0x00100000;
	var P9_STAT_MODE_SETUID = 0x00080000;
	var P9_STAT_MODE_SETGID = 0x00040000;
	var P9_STAT_MODE_SETVTX = 0x00010000;

	var FID_NONE = -1;
	var FID_INODE = 1;
	var FID_XATTR = 2;

	/**
	* @constructor
	*
	* @param {FS} filesystem
	*/
	function Virtio9p(filesystem, bus) {
	/** @const @type {FS} */
	this.fs = filesystem;

	/** @const @type {BusConnector} */
	this.bus = bus;

	this.SendReply = function(x) {};
	this.deviceid = 0x9; // 9p filesystem
	this.hostfeature = 0x1; // mountpoint
	//this.configspace = [0x0, 0x4, 0x68, 0x6F, 0x73, 0x74]; // length of string and "host" string
	//this.configspace = [0x0, 0x9, 0x2F, 0x64, 0x65, 0x76, 0x2F, 0x72, 0x6F, 0x6F, 0x74 ]; // length of string and "/dev/root" string

	this.configspace = new Uint8Array([0x6, 0x0, 0x68, 0x6F, 0x73, 0x74, 0x39, 0x70]); // length of string and "host9p" string
	this.VERSION = "9P2000.L";
	this.BLOCKSIZE = 8192; // Let's define one page.
	this.msize = 8192; // maximum message size
	this.replybuffer = new Uint8Array(this.msize*2); // Twice the msize to stay on the safe site
	this.replybuffersize = 0;

	this.fids = [];
	}

	Virtio9p.prototype.get_state = function()
	{
	var state = [];

	state[0] = this.deviceid;
	state[1] = this.hostfeature;
	state[2] = this.configspace;
	state[3] = this.VERSION;
	state[4] = this.BLOCKSIZE;
	state[5] = this.msize;
	state[6] = this.replybuffer;
	state[7] = this.replybuffersize;
	state[8] = this.fids.map(function(f) { return [f.inodeid, f.type, f.uid] });

	return state;
	};

	Virtio9p.prototype.set_state = function(state)
	{
	this.deviceid = state[0];
	this.hostfeature = state[1];
	this.configspace = state[2];
	this.VERSION = state[3];
	this.BLOCKSIZE = state[4];
	this.msize = state[5];
	this.replybuffer = state[6];
	this.replybuffersize = state[7];
	this.fids = state[8].map(function(f) { return { inodeid: f[0], type: f[1], uid: f[2] } });
	};

	Virtio9p.prototype.Createfid = function(inode, type, uid) {
	return {inodeid: inode, type: type, uid: uid};
	}

	Virtio9p.prototype.Reset = function() {
	this.fids = [];
	}

	Virtio9p.prototype.BuildReply = function(id, tag, payloadsize) {
	Marshall(["w", "b", "h"], [payloadsize+7, id+1, tag], this.replybuffer, 0);
	if ((payloadsize+7) >= this.replybuffer.length) {
	DebugMessage("Error in 9p: payloadsize exceeds maximum length");
	}
	//for(var i=0; i<payload.length; i++)
	// this.replybuffer[7+i] = payload[i];
	this.replybuffersize = payloadsize+7;
	return;
	}

	Virtio9p.prototype.SendError = function (tag, errormsg, errorcode) {
	//var size = Marshall(["s", "w"], [errormsg, errorcode], this.replybuffer, 7);
	var size = Marshall(["w"], [errorcode], this.replybuffer, 7);
	this.BuildReply(6, tag, size);
	}

	Virtio9p.prototype.ReceiveRequest = function (index, GetByte) {
	var header = Unmarshall2(["w", "b", "h"], GetByte);
	//var size = header[0];
	var id = header[1];
	var tag = header[2];
	//DebugMessage("size:" + size + " id:" + id + " tag:" + tag);

	switch(id)
	{
	case 8: // statfs
	var size = this.fs.GetTotalSize(); // size used by all files
	var space = this.fs.GetSpace();
	var req = [];
	req[0] = 0x01021997;
	req[1] = this.BLOCKSIZE; // optimal transfer block size
	req[2] = Math.floor(space/req[1]); // free blocks, let's say 1GB
	req[3] = req[2] - Math.floor(size/req[1]); // free blocks in fs
	req[4] = req[2] - Math.floor(size/req[1]); // free blocks avail to non-superuser
	req[5] = this.fs.inodes.length; // total number of inodes
	req[6] = 1024*1024;
	req[7] = 0; // file system id?
	req[8] = 256; // maximum length of filenames

	size = Marshall(["w", "w", "d", "d", "d", "d", "d", "d", "w"], req, this.replybuffer, 7);
	this.BuildReply(id, tag, size);
	this.SendReply(index);
	break;

	case 112: // topen
	case 12: // tlopen
	var req = Unmarshall2(["w", "w"], GetByte);
	var fid = req[0];
	var mode = req[1];
	DebugMessage("[open] fid=" + fid + ", mode=" + mode);
	var inode = this.fs.GetInode(this.fids[fid].inodeid);
	req[0] = inode.qid;
	req[1] = this.msize - 24;
	Marshall(["Q", "w"], req, this.replybuffer, 7);
	this.BuildReply(id, tag, 13+4);
	DebugMessage("file open " + inode.name);
	//if (inode.status == STATUS_LOADING) return;
	var ret = this.fs.OpenInode(this.fids[fid].inodeid, mode);
	this.fs.AddEvent(this.fids[fid].inodeid,
	function() {
	DebugMessage("file opened " + inode.name + " tag:"+tag);
	req[0] = inode.qid;
	req[1] = this.msize - 24;
	Marshall(["Q", "w"], req, this.replybuffer, 7);
	this.BuildReply(id, tag, 13+4);
	this.SendReply(index);
	}.bind(this)
	);
	break;

	case 70: // link (just copying)
	var req = Unmarshall2(["w", "w", "s"], GetByte);
	var dfid = req[0];
	var fid = req[1];
	var name = req[2];
	DebugMessage("[link] dfid=" + dfid + ", name=" + name);
	var inode = this.fs.CreateInode();
	var inodetarget = this.fs.GetInode(this.fids[fid].inodeid);
	var targetdata = this.fs.inodedata[this.fids[fid].inodeid];
	//inode = inodetarget;
	inode.mode = inodetarget.mode;
	inode.size = inodetarget.size;
	inode.symlink = inodetarget.symlink;
	var data = this.fs.inodedata[this.fs.inodes.length] = new Uint8Array(inode.size);
	//inode.waswritten = true;
	for(var i=0; i<inode.size; i++) {
	data[i] = targetdata[i];
	}
	inode.name = name;
	inode.parentid = this.fids[dfid].inodeid;
	this.fs.PushInode(inode);

	//inode.uid = inodetarget.uid;
	//inode.gid = inodetarget.gid;
	//inode.mode = inodetarget.mode \| S_IFLNK;
	this.BuildReply(id, tag, 0);
	this.SendReply(index);
	break;

	case 16: // symlink
	var req = Unmarshall2(["w", "s", "s", "w"], GetByte);
	var fid = req[0];
	var name = req[1];
	var symgt = req[2];
	var gid = req[3];
	DebugMessage("[symlink] fid=" + fid + ", name=" + name + ", symgt=" + symgt + ", gid=" + gid);
	var idx = this.fs.CreateSymlink(name, this.fids[fid].inodeid, symgt);
	var inode = this.fs.GetInode(idx);
	inode.uid = this.fids[fid].uid;
	inode.gid = gid;
	Marshall(["Q"], [inode.qid], this.replybuffer, 7);
	this.BuildReply(id, tag, 13);
	this.SendReply(index);
	break;

	case 18: // mknod
	var req = Unmarshall2(["w", "s", "w", "w", "w", "w"], GetByte);
	var fid = req[0];
	var name = req[1];
	var mode = req[2];
	var major = req[3];
	var minor = req[4];
	var gid = req[5];
	DebugMessage("[mknod] fid=" + fid + ", name=" + name + ", major=" + major + ", minor=" + minor+ "");
	var idx = this.fs.CreateNode(name, this.fids[fid].inodeid, major, minor);
	var inode = this.fs.GetInode(idx);
	inode.mode = mode;
	inode.uid = this.fids[fid].uid;
	inode.gid = gid;
	Marshall(["Q"], [inode.qid], this.replybuffer, 7);
	this.BuildReply(id, tag, 13);
	this.SendReply(index);
	break;


	case 22: // TREADLINK
	var req = Unmarshall2(["w"], GetByte);
	var fid = req[0];
	DebugMessage("[readlink] fid=" + fid);
	var inode = this.fs.GetInode(this.fids[fid].inodeid);
	var size = Marshall(["s"], [inode.symlink], this.replybuffer, 7);
	this.BuildReply(id, tag, size);
	this.SendReply(index);
	break;


	case 72: // tmkdir
	var req = Unmarshall2(["w", "s", "w", "w"], GetByte);
	var fid = req[0];
	var name = req[1];
	var mode = req[2];
	var gid = req[3];
	DebugMessage("[mkdir] fid=" + fid + ", name=" + name + ", mode=" + mode + ", gid=" + gid);
	var idx = this.fs.CreateDirectory(name, this.fids[fid].inodeid);
	var inode = this.fs.GetInode(idx);
	inode.mode = mode \| S_IFDIR;
	inode.uid = this.fids[fid].uid;
	inode.gid = gid;
	Marshall(["Q"], [inode.qid], this.replybuffer, 7);
	this.BuildReply(id, tag, 13);
	this.SendReply(index);
	break;

	case 14: // tlcreate
	var req = Unmarshall2(["w", "s", "w", "w", "w"], GetByte);
	var fid = req[0];
	var name = req[1];
	var flags = req[2];
	var mode = req[3];
	var gid = req[4];
	DebugMessage("[create] fid=" + fid + ", name=" + name + ", flags=" + flags + ", mode=" + mode + ", gid=" + gid);
	var idx = this.fs.CreateFile(name, this.fids[fid].inodeid);
	this.fids[fid].inodeid = idx;
	this.fids[fid].type = FID_INODE;
	var inode = this.fs.GetInode(idx);
	inode.uid = this.fids[fid].uid;
	inode.gid = gid;
	inode.mode = mode;
	Marshall(["Q", "w"], [inode.qid, this.msize - 24], this.replybuffer, 7);
	this.BuildReply(id, tag, 13+4);
	this.SendReply(index);
	break;

	case 52: // lock always suceed
	DebugMessage("lock file\n");
	Marshall(["w"], [0], this.replybuffer, 7);
	this.BuildReply(id, tag, 1);
	this.SendReply(index);
	break;

	/*
	case 54: // getlock
	break;
	*/

	case 24: // getattr
	var req = Unmarshall2(["w", "d"], GetByte);
	var fid = req[0];
	var inode = this.fs.GetInode(this.fids[fid].inodeid);
	DebugMessage("[getattr]: fid=" + fid + " name=" + inode.name + " request mask=" + req[1]);
	req[0] \|= 0x1000; // P9_STATS_GEN

	req[0] = req[1]; // request mask
	req[1] = inode.qid;

	req[2] = inode.mode;
	req[3] = inode.uid; // user id
	req[4] = inode.gid; // group id

	req[5] = 0x1; // number of hard links
	req[6] = (inode.major<<8) \| (inode.minor); // device id low
	req[7] = inode.size; // size low
	req[8] = this.BLOCKSIZE;
	req[9] = Math.floor(inode.size/512+1);; // blk size low
	req[10] = inode.atime; // atime
	req[11] = 0x0;
	req[12] = inode.mtime; // mtime
	req[13] = 0x0;
	req[14] = inode.ctime; // ctime
	req[15] = 0x0;
	req[16] = 0x0; // btime
	req[17] = 0x0;
	req[18] = 0x0; // st_gen
	req[19] = 0x0; // data_version
	Marshall([
	"d", "Q",
	"w",
	"w", "w",
	"d", "d",
	"d", "d", "d",
	"d", "d", // atime
	"d", "d", // mtime
	"d", "d", // ctime
	"d", "d", // btime
	"d", "d",
	], req, this.replybuffer, 7);
	this.BuildReply(id, tag, 8 + 13 + 4 + 4+ 4 + 8*15);
	this.SendReply(index);
	break;

	case 26: // setattr
	var req = Unmarshall2(["w", "w",
	"w", // mode
	"w", "w", // uid, gid
	"d", // size
	"d", "d", // atime
	"d", "d"] // mtime
	, GetByte);
	var fid = req[0];
	var inode = this.fs.GetInode(this.fids[fid].inodeid);
	DebugMessage("[setattr]: fid=" + fid + " request mask=" + req[1] + " name=" +inode.name);
	if (req[1] & P9_SETATTR_MODE) {
	inode.mode = req[2];
	}
	if (req[1] & P9_SETATTR_UID) {
	inode.uid = req[3];
	}
	if (req[1] & P9_SETATTR_GID) {
	inode.gid = req[4];
	}
	if (req[1] & P9_SETATTR_ATIME_SET) {
	inode.atime = req[6];
	}
	if (req[1] & P9_SETATTR_MTIME_SET) {
	inode.atime = req[8];
	}
	if (req[1] & P9_SETATTR_ATIME) {
	inode.atime = Math.floor((new Date()).getTime()/1000);
	}
	if (req[1] & P9_SETATTR_MTIME) {
	inode.mtime = Math.floor((new Date()).getTime()/1000);
	}
	if (req[1] & P9_SETATTR_CTIME) {
	inode.ctime = Math.floor((new Date()).getTime()/1000);
	}
	if (req[1] & P9_SETATTR_SIZE) {
	this.fs.ChangeSize(this.fids[fid].inodeid, req[5]);
	}
	this.BuildReply(id, tag, 0);
	this.SendReply(index);
	break;

	case 50: // fsync
	var req = Unmarshall2(["w", "d"], GetByte);
	var fid = req[0];
	this.BuildReply(id, tag, 0);
	this.SendReply(index);
	break;

	case 40: // TREADDIR
	case 116: // read
	var req = Unmarshall2(["w", "d", "w"], GetByte);
	var fid = req[0];
	var offset = req[1];
	var count = req[2];
	var inode = this.fs.GetInode(this.fids[fid].inodeid);
	if (id == 40) DebugMessage("[treaddir]: fid=" + fid + " offset=" + offset + " count=" + count);
	if (id == 116) DebugMessage("[read]: fid=" + fid + " (" + inode.name + ") offset=" + offset + " count=" + count + " fidtype=" + this.fids[fid].type);
	if (this.fids[fid].type == FID_XATTR) {
	if (inode.caps.length < offset+count) count = inode.caps.length - offset;
	for(var i=0; i<count; i++)
	this.replybuffer[7+4+i] = inode.caps[offset+i];
	Marshall(["w"], [count], this.replybuffer, 7);
	this.BuildReply(id, tag, 4 + count);
	this.SendReply(index);
	} else {
	var file = this.fs.inodes[this.fids[fid].inodeid];
	this.bus.send("9p-read-start");

	this.fs.OpenInode(this.fids[fid].inodeid, undefined);
	this.fs.AddEvent(this.fids[fid].inodeid,
	function() {
	this.bus.send("9p-read-end", [file.name, count]);

	if (inode.size < offset+count) count = inode.size - offset;
	var data = this.fs.inodedata[this.fids[fid].inodeid];
	if(data) {
	for(var i=0; i<count; i++)
	this.replybuffer[7+4+i] = data[offset+i];
	}
	Marshall(["w"], [count], this.replybuffer, 7);
	this.BuildReply(id, tag, 4 + count);
	this.SendReply(index);
	}.bind(this)
	);
	}
	break;

	case 118: // write
	var req = Unmarshall2(["w", "d", "w"], GetByte);
	var fid = req[0];
	var offset = req[1];
	var count = req[2];
	DebugMessage("[write]: fid=" + fid + " (" + this.fs.inodes[this.fids[fid].inodeid].name + ") offset=" + offset + " count=" + count);
	this.fs.Write(this.fids[fid].inodeid, offset, count, GetByte);

	var file = this.fs.inodes[this.fids[fid].inodeid];
	this.bus.send("9p-write-end", [file.name, count]);

	Marshall(["w"], [count], this.replybuffer, 7);
	this.BuildReply(id, tag, 4);
	this.SendReply(index);
	break;

	case 74: // RENAMEAT
	var req = Unmarshall2(["w", "s", "w", "s"], GetByte);
	var olddirfid = req[0];
	var oldname = req[1];
	var newdirfid = req[2];
	var newname = req[3];
	DebugMessage("[renameat]: oldname=" + oldname + " newname=" + newname);
	var ret = this.fs.Rename(this.fids[olddirfid].inodeid, oldname, this.fids[newdirfid].inodeid, newname);
	if (ret == false) {
	this.SendError(tag, "No such file or directory", ENOENT);
	this.SendReply(index);
	break;
	}
	this.BuildReply(id, tag, 0);
	this.SendReply(index);
	break;

	case 76: // TUNLINKAT
	var req = Unmarshall2(["w", "s", "w"], GetByte);
	var dirfd = req[0];
	var name = req[1];
	var flags = req[2];
	DebugMessage("[unlink]: dirfd=" + dirfd + " name=" + name + " flags=" + flags);
	var fid = this.fs.Search(this.fids[dirfd].inodeid, name);
	if (fid == -1) {
	this.SendError(tag, "No such file or directory", ENOENT);
	this.SendReply(index);
	break;
	}
	var ret = this.fs.Unlink(fid);
	if (!ret) {
	this.SendError(tag, "Directory not empty", ENOTEMPTY);
	this.SendReply(index);
	break;
	}
	this.BuildReply(fid, tag, 0);
	this.SendReply(index);
	break;

	case 100: // version
	var version = Unmarshall2(["w", "s"], GetByte);
	DebugMessage("[version]: msize=" + version[0] + " version=" + version[1]);
	this.msize = version[0];
	var size = Marshall(["w", "s"], [this.msize, this.VERSION], this.replybuffer, 7);
	this.BuildReply(id, tag, size);
	this.SendReply(index);
	break;

	case 104: // attach
	// return root directorie's QID
	var req = Unmarshall2(["w", "w", "s", "s", "w"], GetByte);
	var fid = req[0];
	var uid = req[4];
	DebugMessage("[attach]: fid=" + fid + " afid=" + hex8(req[1]) + " uname=" + req[2] + " aname=" + req[3]);
	this.fids[fid] = this.Createfid(0, FID_INODE, uid);
	var inode = this.fs.GetInode(this.fids[fid].inodeid);
	Marshall(["Q"], [inode.qid], this.replybuffer, 7);
	this.BuildReply(id, tag, 13);
	this.SendReply(index);
	break;

	case 108: // tflush
	var req = Unmarshall2(["h"], GetByte);
	var oldtag = req[0];
	DebugMessage("[flush] " + tag);
	//Marshall(["Q"], [inode.qid], this.replybuffer, 7);
	this.BuildReply(id, tag, 0);
	this.SendReply(index);
	break;


	case 110: // walk
	var req = Unmarshall2(["w", "w", "h"], GetByte);
	var fid = req[0];
	var nwfid = req[1];
	var nwname = req[2];
	DebugMessage("[walk]: fid=" + req[0] + " nwfid=" + req[1] + " nwname=" + nwname);
	if (nwname == 0) {
	this.fids[nwfid] = this.Createfid(this.fids[fid].inodeid, FID_INODE, this.fids[fid].uid);
	//this.fids[nwfid].inodeid = this.fids[fid].inodeid;
	Marshall(["h"], [0], this.replybuffer, 7);
	this.BuildReply(id, tag, 2);
	this.SendReply(index);
	break;
	}
	var wnames = [];
	for(var i=0; i<nwname; i++) {
	wnames.push("s");
	}
	var walk = Unmarshall2(wnames, GetByte);
	var idx = this.fids[fid].inodeid;
	var offset = 7+2;
	var nwidx = 0;
	//console.log(idx, this.fs.inodes[idx]);
	DebugMessage("walk in dir " + this.fs.inodes[idx].name + " to: " + walk.toString());
	for(var i=0; i<nwname; i++) {
	idx = this.fs.Search(idx, walk[i]);

	if (idx == -1) {
	DebugMessage("Could not find: " + walk[i]);
	break;
	}
	offset += Marshall(["Q"], [this.fs.inodes[idx].qid], this.replybuffer, offset);
	nwidx++;
	//DebugMessage(this.fids[nwfid].inodeid);
	//this.fids[nwfid].inodeid = idx;
	//this.fids[nwfid].type = FID_INODE;
	this.fids[nwfid] = this.Createfid(idx, FID_INODE, this.fids[fid].uid);
	}
	Marshall(["h"], [nwidx], this.replybuffer, 7);
	this.BuildReply(id, tag, offset-7);
	this.SendReply(index);
	break;

	case 120: // clunk
	var req = Unmarshall2(["w"], GetByte);
	DebugMessage("[clunk]: fid=" + req[0]);
	if (this.fids[req[0]] && this.fids[req[0]].inodeid >= 0) {
	this.fs.CloseInode(this.fids[req[0]].inodeid);
	this.fids[req[0]].inodeid = -1;
	this.fids[req[0]].type = FID_NONE;
	}
	this.BuildReply(id, tag, 0);
	this.SendReply(index);
	break;

	case 32:
	this.SendError(tag, "Operation i not supported", ENOTSUPP);
	this.SendReply(index);
	break;

	case 30: // xattrwalk
	var req = Unmarshall2(["w", "w", "s"], GetByte);
	var fid = req[0];
	var newfid = req[1];
	var name = req[2];
	DebugMessage("[xattrwalk]: fid=" + req[0] + " newfid=" + req[1] + " name=" + req[2]);
	this.fids[newfid] = this.Createfid(this.fids[fid].inodeid, FID_NONE, this.fids[fid].uid);
	//this.fids[newfid].inodeid = this.fids[fid].inodeid;
	//this.fids[newfid].type = FID_NONE;
	var length = 0;
	if (name == "security.capability") {
	length = this.fs.PrepareCAPs(this.fids[fid].inodeid);
	this.fids[newfid].type = FID_XATTR;
	}
	Marshall(["d"], [length], this.replybuffer, 7);
	this.BuildReply(id, tag, 8);
	this.SendReply(index);
	break;

	default:
	DebugMessage("Error in Virtio9p: Unknown id " + id + " received");
	abort();
	//this.SendError(tag, "Operation i not supported", ENOTSUPP);
	//this.SendReply(index);
	break;
	}

	//consistency checks if there are problems with the filesystem
	//this.fs.Check();
	}