src/utilities/NBDServer.js - openbmc/webui-vue - Gitiles

 /* handshake flags */
 const NBD_FLAG_FIXED_NEWSTYLE = 0x1;
 const NBD_FLAG_NO_ZEROES = 0x2;

 /* transmission flags */
 const NBD_FLAG_HAS_FLAGS = 0x1;
 const NBD_FLAG_READ_ONLY = 0x2;

 /* option negotiation */
 const NBD_OPT_EXPORT_NAME = 0x1;
 const NBD_REP_FLAG_ERROR = 0x1 << 31;
 const NBD_REP_ERR_UNSUP = NBD_REP_FLAG_ERROR | 1;

 /* command definitions */
 const NBD_CMD_READ = 0;
 const NBD_CMD_WRITE = 1;
 const NBD_CMD_DISC = 2;
 const NBD_CMD_TRIM = 4;

 /* errno */
 const EPERM = 1;
 const EIO = 5;
 const EINVAL = 22;
 const ENOSPC = 28;

 /* internal object state */
 const NBD_STATE_UNKNOWN = 1;
 const NBD_STATE_OPEN = 2;
 const NBD_STATE_WAIT_CFLAGS = 3;
 const NBD_STATE_WAIT_OPTION = 4;
 const NBD_STATE_TRANSMISSION = 5;

 export default class NBDServer {
   constructor(endpoint, file, id, token) {
     this.socketStarted = () => {};
     this.socketClosed = () => {};
     this.errorReadingFile = () => {};
     this.file = file;
     this.id = id;
     this.endpoint = endpoint;
     this.ws = null;
     this.state = NBD_STATE_UNKNOWN;
     this.msgbuf = null;
     this.start = function() {
       this.ws = new WebSocket(this.endpoint, [token]);
       this.state = NBD_STATE_OPEN;
       this.ws.binaryType = 'arraybuffer';
       this.ws.onmessage = this._on_ws_message.bind(this);
       this.ws.onopen = this._on_ws_open.bind(this);
       this.ws.onclose = this._on_ws_close.bind(this);
       this.ws.onerror = this._on_ws_error.bind(this);
       this.socketStarted();
     };
     this.stop = function() {
       if (this.ws.readyState == 1) {
         this.ws.close();
         this.state = NBD_STATE_UNKNOWN;
       }
     };
     this._on_ws_error = function(ev) {
       console.log(`${endpoint} error: ${ev.error}`);
       console.log(JSON.stringify(ev));
     };
     this._on_ws_close = function(ev) {
       console.log(
         `${endpoint} closed with code: ${ev.code} + reason: ${ev.reason}`
       );
       console.log(JSON.stringify(ev));
       this.socketClosed(ev.code);
     };
     /* websocket event handlers */
     this._on_ws_open = function() {
       console.log(endpoint + ' opened');
       this.client = {
         flags: 0
       };
       this._negotiate();
     };
     this._on_ws_message = function(ev) {
       var data = ev.data;
       if (this.msgbuf == null) {
         this.msgbuf = data;
       } else {
         const tmp = new Uint8Array(this.msgbuf.byteLength + data.byteLength);
         tmp.set(new Uint8Array(this.msgbuf), 0);
         tmp.set(new Uint8Array(data), this.msgbuf.byteLength);
         this.msgbuf = tmp.buffer;
       }
       for (;;) {
         var handler = this.recv_handlers[this.state];
         if (!handler) {
           console.log('no handler for state ' + this.state);
           this.stop();
           break;
         }
         var consumed = handler(this.msgbuf);
         if (consumed < 0) {
           console.log(
             'handler[state=' + this.state + '] returned error ' + consumed
           );
           this.stop();
           break;
         }
         if (consumed == 0) {
           break;
         }
         if (consumed > 0) {
           if (consumed == this.msgbuf.byteLength) {
             this.msgbuf = null;
             break;
           }
           this.msgbuf = this.msgbuf.slice(consumed);
         }
       }
     };
     this._negotiate = function() {
       var buf = new ArrayBuffer(18);
       var data = new DataView(buf, 0, 18);
       /* NBD magic: NBDMAGIC */
       data.setUint32(0, 0x4e42444d);
       data.setUint32(4, 0x41474943);
       /* newstyle negotiation: IHAVEOPT */
       data.setUint32(8, 0x49484156);
       data.setUint32(12, 0x454f5054);
       /* flags: fixed newstyle negotiation, no padding */
       data.setUint16(16, NBD_FLAG_FIXED_NEWSTYLE | NBD_FLAG_NO_ZEROES);
       this.state = NBD_STATE_WAIT_CFLAGS;
       this.ws.send(buf);
     };
     /* handlers */
     this._handle_cflags = function(buf) {
       if (buf.byteLength < 4) {
         return 0;
       }
       var data = new DataView(buf, 0, 4);
       this.client.flags = data.getUint32(0);
       this.state = NBD_STATE_WAIT_OPTION;
       return 4;
     };
     this._handle_option = function(buf) {
       if (buf.byteLength < 16) return 0;
       var data = new DataView(buf, 0, 16);
       if (data.getUint32(0) != 0x49484156 || data.getUint32(4) != 0x454f5054) {
         console.log('invalid option magic');
         return -1;
       }
       var opt = data.getUint32(8);
       var len = data.getUint32(12);
       if (buf.byteLength < 16 + len) {
         return 0;
       }
       switch (opt) {
         case NBD_OPT_EXPORT_NAME:
           var n = 10;
           if (!(this.client.flags & NBD_FLAG_NO_ZEROES)) n += 124;
           var resp = new ArrayBuffer(n);
           var view = new DataView(resp, 0, 10);
           /* export size. */
           var size = this.file.size;
           // eslint-disable-next-line prettier/prettier
           view.setUint32(0, Math.floor(size / (2 ** 32)));
           view.setUint32(4, size & 0xffffffff);
           /* transmission flags: read-only */
           view.setUint16(8, NBD_FLAG_HAS_FLAGS | NBD_FLAG_READ_ONLY);
           this.ws.send(resp);
           this.state = NBD_STATE_TRANSMISSION;
           break;
         default:
           console.log('handle_option: Unsupported option: ' + opt);
           /* reject other options */
           var resp1 = new ArrayBuffer(20);
           var view1 = new DataView(resp1, 0, 20);
           view1.setUint32(0, 0x0003e889);
           view1.setUint32(4, 0x045565a9);
           view1.setUint32(8, opt);
           view1.setUint32(12, NBD_REP_ERR_UNSUP);
           view1.setUint32(16, 0);
           this.ws.send(resp1);
       }
       return 16 + len;
     };
     this._create_cmd_response = function(req, rc, data = null) {
       var len = 16;
       if (data) len += data.byteLength;
       var resp = new ArrayBuffer(len);
       var view = new DataView(resp, 0, 16);
       view.setUint32(0, 0x67446698);
       view.setUint32(4, rc);
       view.setUint32(8, req.handle_msB);
       view.setUint32(12, req.handle_lsB);
       if (data) new Uint8Array(resp, 16).set(new Uint8Array(data));
       return resp;
     };
     this._handle_cmd = function(buf) {
       if (buf.byteLength < 28) {
         return 0;
       }
       var view = new DataView(buf, 0, 28);
       if (view.getUint32(0) != 0x25609513) {
         console.log('invalid request magic');
         return -1;
       }
       var req = {
         flags: view.getUint16(4),
         type: view.getUint16(6),
         handle_msB: view.getUint32(8),
         handle_lsB: view.getUint32(12),
         offset_msB: view.getUint32(16),
         offset_lsB: view.getUint32(20),
         length: view.getUint32(24)
       };
       /* we don't support writes, so nothing needs the data at present */
       /* req.data = buf.slice(28); */
       var err = 0;
       var consumed = 28;
       /* the command handlers return 0 on success, and send their
        * own response. Otherwise, a non-zero error code will be
        * used as a simple error response
        */
       switch (req.type) {
         case NBD_CMD_READ:
           err = this._handle_cmd_read(req);
           break;
         case NBD_CMD_DISC:
           err = this._handle_cmd_disconnect(req);
           break;
         case NBD_CMD_WRITE:
           /* we also need length bytes of data to consume a write
            * request */
           if (buf.byteLength < 28 + req.length) {
             return 0;
           }
           consumed += req.length;
           err = EPERM;
           break;
         case NBD_CMD_TRIM:
           err = EPERM;
           break;
         default:
           console.log('invalid command 0x' + req.type.toString(16));
           err = EINVAL;
       }
       if (err) {
         console.log('error handle_cmd: ' + err);
         var resp = this._create_cmd_response(req, err);
         this.ws.send(resp);
         if (err == ENOSPC) {
           this.errorReadingFile();
           this.stop();
         }
       }
       return consumed;
     };
     this._handle_cmd_read = function(req) {
       var offset;
       // eslint-disable-next-line prettier/prettier
       offset = (req.offset_msB * 2 ** 32) + req.offset_lsB;
       if (offset > Number.MAX_SAFE_INTEGER) return ENOSPC;
       if (offset + req.length > Number.MAX_SAFE_INTEGER) return ENOSPC;
       if (offset + req.length > file.size) return ENOSPC;
       var blob = this.file.slice(offset, offset + req.length);
       var reader = new FileReader();

       reader.onload = function(ev) {
         var reader = ev.target;
         if (reader.readyState != FileReader.DONE) return;
         var resp = this._create_cmd_response(req, 0, reader.result);
         this.ws.send(resp);
       }.bind(this);

       reader.onerror = function(ev) {
         var reader = ev.target;
         console.log('error reading file: ' + reader.error);
         var resp = this._create_cmd_response(req, EIO);
         this.ws.send(resp);
       }.bind(this);
       reader.readAsArrayBuffer(blob);
       return 0;
     };
     this._handle_cmd_disconnect = function() {
       this.stop();
       return 0;
     };
     this.recv_handlers = Object.freeze({
       [NBD_STATE_WAIT_CFLAGS]: this._handle_cflags.bind(this),
       [NBD_STATE_WAIT_OPTION]: this._handle_option.bind(this),
       [NBD_STATE_TRANSMISSION]: this._handle_cmd.bind(this)
     });
   }
 }
	/* handshake flags */
	const NBD_FLAG_FIXED_NEWSTYLE = 0x1;
	const NBD_FLAG_NO_ZEROES = 0x2;

	/* transmission flags */
	const NBD_FLAG_HAS_FLAGS = 0x1;
	const NBD_FLAG_READ_ONLY = 0x2;

	/* option negotiation */
	const NBD_OPT_EXPORT_NAME = 0x1;
	const NBD_REP_FLAG_ERROR = 0x1 << 31;
	const NBD_REP_ERR_UNSUP = NBD_REP_FLAG_ERROR \| 1;

	/* command definitions */
	const NBD_CMD_READ = 0;
	const NBD_CMD_WRITE = 1;
	const NBD_CMD_DISC = 2;
	const NBD_CMD_TRIM = 4;

	/* errno */
	const EPERM = 1;
	const EIO = 5;
	const EINVAL = 22;
	const ENOSPC = 28;

	/* internal object state */
	const NBD_STATE_UNKNOWN = 1;
	const NBD_STATE_OPEN = 2;
	const NBD_STATE_WAIT_CFLAGS = 3;
	const NBD_STATE_WAIT_OPTION = 4;
	const NBD_STATE_TRANSMISSION = 5;

	export default class NBDServer {
	constructor(endpoint, file, id, token) {
	this.socketStarted = () => {};
	this.socketClosed = () => {};
	this.errorReadingFile = () => {};
	this.file = file;
	this.id = id;
	this.endpoint = endpoint;
	this.ws = null;
	this.state = NBD_STATE_UNKNOWN;
	this.msgbuf = null;
	this.start = function() {
	this.ws = new WebSocket(this.endpoint, [token]);
	this.state = NBD_STATE_OPEN;
	this.ws.binaryType = 'arraybuffer';
	this.ws.onmessage = this._on_ws_message.bind(this);
	this.ws.onopen = this._on_ws_open.bind(this);
	this.ws.onclose = this._on_ws_close.bind(this);
	this.ws.onerror = this._on_ws_error.bind(this);
	this.socketStarted();
	};
	this.stop = function() {
	if (this.ws.readyState == 1) {
	this.ws.close();
	this.state = NBD_STATE_UNKNOWN;
	}
	};
	this._on_ws_error = function(ev) {
	console.log(`${endpoint} error: ${ev.error}`);
	console.log(JSON.stringify(ev));
	};
	this._on_ws_close = function(ev) {
	console.log(
	`${endpoint} closed with code: ${ev.code} + reason: ${ev.reason}`
	);
	console.log(JSON.stringify(ev));
	this.socketClosed(ev.code);
	};
	/* websocket event handlers */
	this._on_ws_open = function() {
	console.log(endpoint + ' opened');
	this.client = {
	flags: 0
	};
	this._negotiate();
	};
	this._on_ws_message = function(ev) {
	var data = ev.data;
	if (this.msgbuf == null) {
	this.msgbuf = data;
	} else {
	const tmp = new Uint8Array(this.msgbuf.byteLength + data.byteLength);
	tmp.set(new Uint8Array(this.msgbuf), 0);
	tmp.set(new Uint8Array(data), this.msgbuf.byteLength);
	this.msgbuf = tmp.buffer;
	}
	for (;;) {
	var handler = this.recv_handlers[this.state];
	if (!handler) {
	console.log('no handler for state ' + this.state);
	this.stop();
	break;
	}
	var consumed = handler(this.msgbuf);
	if (consumed < 0) {
	console.log(
	'handler[state=' + this.state + '] returned error ' + consumed
	);
	this.stop();
	break;
	}
	if (consumed == 0) {
	break;
	}
	if (consumed > 0) {
	if (consumed == this.msgbuf.byteLength) {
	this.msgbuf = null;
	break;
	}
	this.msgbuf = this.msgbuf.slice(consumed);
	}
	}
	};
	this._negotiate = function() {
	var buf = new ArrayBuffer(18);
	var data = new DataView(buf, 0, 18);
	/* NBD magic: NBDMAGIC */
	data.setUint32(0, 0x4e42444d);
	data.setUint32(4, 0x41474943);
	/* newstyle negotiation: IHAVEOPT */
	data.setUint32(8, 0x49484156);
	data.setUint32(12, 0x454f5054);
	/* flags: fixed newstyle negotiation, no padding */
	data.setUint16(16, NBD_FLAG_FIXED_NEWSTYLE \| NBD_FLAG_NO_ZEROES);
	this.state = NBD_STATE_WAIT_CFLAGS;
	this.ws.send(buf);
	};
	/* handlers */
	this._handle_cflags = function(buf) {
	if (buf.byteLength < 4) {
	return 0;
	}
	var data = new DataView(buf, 0, 4);
	this.client.flags = data.getUint32(0);
	this.state = NBD_STATE_WAIT_OPTION;
	return 4;
	};
	this._handle_option = function(buf) {
	if (buf.byteLength < 16) return 0;
	var data = new DataView(buf, 0, 16);
	if (data.getUint32(0) != 0x49484156 \|\| data.getUint32(4) != 0x454f5054) {
	console.log('invalid option magic');
	return -1;
	}
	var opt = data.getUint32(8);
	var len = data.getUint32(12);
	if (buf.byteLength < 16 + len) {
	return 0;
	}
	switch (opt) {
	case NBD_OPT_EXPORT_NAME:
	var n = 10;
	if (!(this.client.flags & NBD_FLAG_NO_ZEROES)) n += 124;
	var resp = new ArrayBuffer(n);
	var view = new DataView(resp, 0, 10);
	/* export size. */
	var size = this.file.size;
	// eslint-disable-next-line prettier/prettier
	view.setUint32(0, Math.floor(size / (2 ** 32)));
	view.setUint32(4, size & 0xffffffff);
	/* transmission flags: read-only */
	view.setUint16(8, NBD_FLAG_HAS_FLAGS \| NBD_FLAG_READ_ONLY);
	this.ws.send(resp);
	this.state = NBD_STATE_TRANSMISSION;
	break;
	default:
	console.log('handle_option: Unsupported option: ' + opt);
	/* reject other options */
	var resp1 = new ArrayBuffer(20);
	var view1 = new DataView(resp1, 0, 20);
	view1.setUint32(0, 0x0003e889);
	view1.setUint32(4, 0x045565a9);
	view1.setUint32(8, opt);
	view1.setUint32(12, NBD_REP_ERR_UNSUP);
	view1.setUint32(16, 0);
	this.ws.send(resp1);
	}
	return 16 + len;
	};
	this._create_cmd_response = function(req, rc, data = null) {
	var len = 16;
	if (data) len += data.byteLength;
	var resp = new ArrayBuffer(len);
	var view = new DataView(resp, 0, 16);
	view.setUint32(0, 0x67446698);
	view.setUint32(4, rc);
	view.setUint32(8, req.handle_msB);
	view.setUint32(12, req.handle_lsB);
	if (data) new Uint8Array(resp, 16).set(new Uint8Array(data));
	return resp;
	};
	this._handle_cmd = function(buf) {
	if (buf.byteLength < 28) {
	return 0;
	}
	var view = new DataView(buf, 0, 28);
	if (view.getUint32(0) != 0x25609513) {
	console.log('invalid request magic');
	return -1;
	}
	var req = {
	flags: view.getUint16(4),
	type: view.getUint16(6),
	handle_msB: view.getUint32(8),
	handle_lsB: view.getUint32(12),
	offset_msB: view.getUint32(16),
	offset_lsB: view.getUint32(20),
	length: view.getUint32(24)
	};
	/* we don't support writes, so nothing needs the data at present */
	/* req.data = buf.slice(28); */
	var err = 0;
	var consumed = 28;
	/* the command handlers return 0 on success, and send their
	* own response. Otherwise, a non-zero error code will be
	* used as a simple error response
	*/
	switch (req.type) {
	case NBD_CMD_READ:
	err = this._handle_cmd_read(req);
	break;
	case NBD_CMD_DISC:
	err = this._handle_cmd_disconnect(req);
	break;
	case NBD_CMD_WRITE:
	/* we also need length bytes of data to consume a write
	* request */
	if (buf.byteLength < 28 + req.length) {
	return 0;
	}
	consumed += req.length;
	err = EPERM;
	break;
	case NBD_CMD_TRIM:
	err = EPERM;
	break;
	default:
	console.log('invalid command 0x' + req.type.toString(16));
	err = EINVAL;
	}
	if (err) {
	console.log('error handle_cmd: ' + err);
	var resp = this._create_cmd_response(req, err);
	this.ws.send(resp);
	if (err == ENOSPC) {
	this.errorReadingFile();
	this.stop();
	}
	}
	return consumed;
	};
	this._handle_cmd_read = function(req) {
	var offset;
	// eslint-disable-next-line prettier/prettier
	offset = (req.offset_msB * 2 ** 32) + req.offset_lsB;
	if (offset > Number.MAX_SAFE_INTEGER) return ENOSPC;
	if (offset + req.length > Number.MAX_SAFE_INTEGER) return ENOSPC;
	if (offset + req.length > file.size) return ENOSPC;
	var blob = this.file.slice(offset, offset + req.length);
	var reader = new FileReader();

	reader.onload = function(ev) {
	var reader = ev.target;
	if (reader.readyState != FileReader.DONE) return;
	var resp = this._create_cmd_response(req, 0, reader.result);
	this.ws.send(resp);
	}.bind(this);

	reader.onerror = function(ev) {
	var reader = ev.target;
	console.log('error reading file: ' + reader.error);
	var resp = this._create_cmd_response(req, EIO);
	this.ws.send(resp);
	}.bind(this);
	reader.readAsArrayBuffer(blob);
	return 0;
	};
	this._handle_cmd_disconnect = function() {
	this.stop();
	return 0;
	};
	this.recv_handlers = Object.freeze({
	[NBD_STATE_WAIT_CFLAGS]: this._handle_cflags.bind(this),
	[NBD_STATE_WAIT_OPTION]: this._handle_option.bind(this),
	[NBD_STATE_TRANSMISSION]: this._handle_cmd.bind(this)
	});
	}
	}