Files: 98b84bb83ad7584f27dafa1f666441f421e0fb44 / interface.js
13596 bytesRaw
1 | /** |
2 | * This is the Ethereum interface that is exposed to the WASM instance which |
3 | * enables to interact with the Ethereum Environment |
4 | */ |
5 | const constants = require('./constants.js') |
6 | const Address = require('./address.js') |
7 | const U256 = require('./u256.js') |
8 | |
9 | // The interface exposed to the WebAessembly Core |
10 | module.exports = class Interface { |
11 | constructor (environment) { |
12 | this.environment = environment |
13 | } |
14 | |
15 | get exportTable () { |
16 | let exportMethods = [ |
17 | // include all the public methods according to the Ethereum Environment Interface (EEI) |
18 | // FIXME: this currently doesn't match EEI r0 |
19 | 'useGas', |
20 | 'gas', |
21 | 'address', |
22 | 'balance', |
23 | 'origin', |
24 | 'caller', |
25 | 'callValue', |
26 | 'callDataSize', |
27 | 'callDataCopy', |
28 | 'codeSize', |
29 | 'codeCopy', |
30 | 'extCodeSize', |
31 | 'extCodeCopy', |
32 | 'gasPrice', |
33 | 'blockHash', |
34 | 'coinbase', |
35 | 'timestamp', |
36 | 'number', |
37 | 'difficulty', |
38 | 'gasLimit', |
39 | 'log', |
40 | 'create', |
41 | 'call', |
42 | 'callDelegate', |
43 | 'sstore', |
44 | 'sload', |
45 | 'return', |
46 | 'suicide' |
47 | ] |
48 | let ret = {} |
49 | exportMethods.forEach((method) => { |
50 | ret[method] = this[method].bind(this) |
51 | }) |
52 | return ret |
53 | } |
54 | |
55 | setModule (mod) { |
56 | this.module = mod |
57 | } |
58 | |
59 | /** |
60 | * Subtracts an amount to the gas counter |
61 | * @param {integer} amount the amount to subtract to the gas counter |
62 | */ |
63 | useGas (amount) { |
64 | if (amount > 0) { |
65 | if (this.environment.gasLimit < amount) { |
66 | throw new Error('Ran out of gas') |
67 | } |
68 | this.environment.gasLimit -= amount |
69 | } |
70 | } |
71 | |
72 | /** |
73 | * Returns the current amount of gas |
74 | * @return {integer} |
75 | */ |
76 | gas () { |
77 | return this.environment.gasLimit |
78 | } |
79 | |
80 | /** |
81 | * Gets address of currently executing account and loads it into memory at |
82 | * the given offset. |
83 | * @param {integer} offset |
84 | */ |
85 | address (offset) { |
86 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.address.toBuffer()) |
87 | } |
88 | |
89 | /** |
90 | * Gets balance of the given account and loads it into memory at the given |
91 | * offset. |
92 | * @param {integer} addressOffset the memory offset to laod the address |
93 | * @param {integer} resultOffset |
94 | */ |
95 | balance (addressOffset, offset) { |
96 | const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
97 | // call the parent contract and ask for the balance of one of its child contracts |
98 | const balance = this.environment.parent.environment.getBalance(address) |
99 | this.setMemory(offset, constants.BALANCE_SIZE_BYTES, balance.toBuffer(constants.BALANCE_SIZE_BYTES)) |
100 | } |
101 | |
102 | /** |
103 | * Gets the execution's origination address and loads it into memory at the |
104 | * given offset. This is the sender of original transaction; it is never an |
105 | * account with non-empty associated code. |
106 | * @param {integer} offset |
107 | */ |
108 | origin (offset) { |
109 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.origin.toBuffer()) |
110 | } |
111 | |
112 | /** |
113 | * Gets caller address and loads it into memory at the given offset. This is |
114 | * the address of the account that is directly responsible for this execution. |
115 | * @param {integer} offset |
116 | */ |
117 | caller (offset) { |
118 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.caller.toBuffer()) |
119 | } |
120 | |
121 | /** |
122 | * Gets the deposited value by the instruction/transaction responsible for |
123 | * this execution and loads it into memory at the given location. |
124 | * @param {integer} offset |
125 | */ |
126 | callValue (offset) { |
127 | this.setMemory(offset, constants.BALANCE_SIZE_BYTES, this.environment.callValue.toBuffer(constants.BALANCE_SIZE_BYTES)) |
128 | } |
129 | |
130 | /** |
131 | * Get size of input data in current environment. This pertains to the input |
132 | * data passed with the message call instruction or transaction. |
133 | * @return {integer} |
134 | */ |
135 | callDataSize () { |
136 | return this.environment.callData.length |
137 | } |
138 | |
139 | /** |
140 | * Copys the input data in current environment to memory. This pertains to |
141 | * the input data passed with the message call instruction or transaction. |
142 | * @param {integer} offset the offset in memory to load into |
143 | * @param {integer} dataOffset the offset in the input data |
144 | * @param {integer} length the length of data to copy |
145 | */ |
146 | callDataCopy (offset, dataOffset, length) { |
147 | const callData = Buffer.from(this.environment.callData.slice(dataOffset, dataOffset + length)).reverse() |
148 | this.setMemory(offset, length, callData) |
149 | } |
150 | |
151 | /** |
152 | * Gets the size of code running in current environment. |
153 | * @return {interger} |
154 | */ |
155 | codeSize () { |
156 | return this.environment.code.length |
157 | } |
158 | |
159 | /** |
160 | * Copys the code running in current environment to memory. |
161 | * @param {integer} offset the memory offset |
162 | * @param {integer} codeOffset the code offset |
163 | * @param {integer} length the length of code to copy |
164 | */ |
165 | codeCopy (offset, codeOffset, length) { |
166 | const code = new Uint8Array(this.environment.code, codeOffset, length) |
167 | this.setMemory(offset, length, code) |
168 | } |
169 | |
170 | /** |
171 | * Get size of an account’s code. |
172 | * @param {integer} addressOffset the offset in memory to load the address from |
173 | * @return {integer} |
174 | */ |
175 | extCodeSize (addressOffset) { |
176 | const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
177 | const code = this.environment.getCode(address) |
178 | return code.length |
179 | } |
180 | |
181 | /** |
182 | * Copys the code of an account to memory. |
183 | * @param {integer} addressOffset the memory offset of the address |
184 | * @param {integer} offset the memory offset |
185 | * @param {integer} codeOffset the code offset |
186 | * @param {integer} length the length of code to copy |
187 | */ |
188 | extCodeCopy (addressOffset, offset, codeOffset, length) { |
189 | const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
190 | let code = this.environment.getCode(address) |
191 | code = new Uint8Array(code, codeOffset, length) |
192 | this.setMemory(offset, length, code) |
193 | } |
194 | |
195 | /** |
196 | * Gets price of gas in current environment. |
197 | * @return {integer} |
198 | */ |
199 | gasPrice () { |
200 | return this.environment.gasPrice |
201 | } |
202 | |
203 | /** |
204 | * Gets the hash of one of the 256 most recent complete blocks. |
205 | * @param {integer} number which block to load |
206 | * @param {integer} offset the offset to load the hash into |
207 | */ |
208 | blockHash (number, offset) { |
209 | const diff = this.environment.number - number |
210 | let hash |
211 | |
212 | if (diff > 256 || diff <= 0) { |
213 | hash = new Uint8Array(32) |
214 | } else { |
215 | hash = this.environment.getBlockHash(number).reverse() |
216 | } |
217 | this.setMemory(offset, 32, hash) |
218 | } |
219 | |
220 | /** |
221 | * Gets the block’s beneficiary address and loads into memory. |
222 | * @param offset |
223 | */ |
224 | coinbase (offset) { |
225 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.coinbase.toBuffer()) |
226 | } |
227 | |
228 | /** |
229 | * Get the block’s timestamp. |
230 | * @return {integer} |
231 | */ |
232 | timestamp () { |
233 | return this.environment.timestamp |
234 | } |
235 | |
236 | /** |
237 | * Get the block’s number. |
238 | * @return {integer} |
239 | */ |
240 | number () { |
241 | return this.environment.number |
242 | } |
243 | |
244 | /** |
245 | * Get the block’s difficulty. |
246 | * @return {integer} |
247 | */ |
248 | difficulty () { |
249 | return this.environment.difficulty |
250 | } |
251 | |
252 | /** |
253 | * Get the block’s gas limit. |
254 | * @return {integer} |
255 | */ |
256 | gasLimit () { |
257 | return this.environment.gasLimit |
258 | } |
259 | |
260 | /** |
261 | * Creates a new log in the current environment |
262 | * @param {integer} dataOffset the offset in memory to load the memory |
263 | * @param {integer} length the data length |
264 | * TODO: replace with variadic |
265 | */ |
266 | log (dataOffset, length, topic1, topic2, topic3, topic4, topic5) { |
267 | const data = this.getMemory(dataOffset, length) |
268 | this.environment.logs.push({ |
269 | data: data, |
270 | topics: [topic1, topic2, topic3, topic4, topic5] |
271 | }) |
272 | } |
273 | |
274 | /** |
275 | * Creates a new contract with a given value. |
276 | * @param {integer} valueOffset the offset in memory to the value from |
277 | * @param {integer} dataOffset the offset to load the code for the new contract from |
278 | * @param {integer} length the data length |
279 | */ |
280 | create (valueOffset, dataOffset, length) { |
281 | const value = new U256(this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES)) |
282 | const data = this.getMemory(dataOffset, length) |
283 | const result = this.environment.create(value, data) |
284 | return result |
285 | } |
286 | |
287 | /** |
288 | * Sends a message with arbiatary data to a given address path |
289 | * @param {integer} addressOffset the offset to load the address path from |
290 | * @param {integer} valueOffset the offset to load the value from |
291 | * @param {integer} dataOffset the offset to load data from |
292 | * @param {integer} dataLength the length of data |
293 | * @param {integer} resultOffset the offset to store the result data at |
294 | * @param {integer} resultLength |
295 | * @param {integer} gas |
296 | * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not |
297 | * TODO: add proper gas counting |
298 | */ |
299 | call (addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength, gas) { |
300 | if (gas === undefined) { |
301 | gas = this.gasLeft() |
302 | } |
303 | // Load the params from mem |
304 | const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
305 | const value = new U256(this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES)) |
306 | const data = this.getMemory(dataOffset, dataLength) |
307 | // Run the call |
308 | const [result, errorCode] = this.environment.call(gas, address, value, data) |
309 | this.setMemory(resultOffset, resultLength, result) |
310 | return errorCode |
311 | } |
312 | |
313 | /** |
314 | * Message-call into this account with an alternative account’s code, but |
315 | * persisting the current values for sender and value. |
316 | * @param {integer} gas |
317 | * @param {integer} addressOffset the offset to load the address path from |
318 | * @param {integer} valueOffset the offset to load the value from |
319 | * @param {integer} dataOffset the offset to load data from |
320 | * @param {integer} dataLength the length of data |
321 | * @param {integer} resultOffset the offset to store the result data at |
322 | * @param {integer} resultLength |
323 | * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not |
324 | */ |
325 | callDelegate (gas, addressOffset, dataOffset, dataLength, resultOffset, resultLength) { |
326 | const data = this.getMemory(dataOffset, dataLength) |
327 | const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
328 | const [result, errorCode] = this.environment.callDelegate(gas, address, data) |
329 | this.setMemory(resultOffset, resultLength, result) |
330 | return errorCode |
331 | } |
332 | |
333 | /** |
334 | * store a value at a given path in long term storage which are both loaded |
335 | * from Memory |
336 | * @param {interger} pathOffest the memory offset to load the the path from |
337 | * @param {interger} valueOffset the memory offset to load the value from |
338 | */ |
339 | sstore (pathOffset, valueOffset) { |
340 | const path = new Buffer(this.getMemory(pathOffset, 32)).toString('hex') |
341 | // copy the value |
342 | const value = this.getMemory(valueOffset, 32).slice(0) |
343 | const oldValue = this.environment.state.get(path) |
344 | const valIsZero = value.every((i) => i === 0) |
345 | |
346 | // write |
347 | if (!valIsZero && !oldValue) { |
348 | this.environment.gasLimit -= 15000 |
349 | } |
350 | |
351 | // delete |
352 | if (valIsZero && oldValue) { |
353 | this.environment.gasRefund += 15000 |
354 | this.environment.state.delete(path) |
355 | } else { |
356 | this.environment.state.set(path, value) |
357 | } |
358 | } |
359 | |
360 | /** |
361 | * reterives a value at a given path in long term storage |
362 | * @param {interger} pathOffest the memory offset to load the the path from |
363 | * @param {interger} resultOffset the memory offset to load the value from |
364 | */ |
365 | sload (pathOffset, resultOffset) { |
366 | const path = new Buffer(this.getMemory(pathOffset, 32)).toString('hex') |
367 | const result = this.environment.state.get(path) |
368 | this.setMemory(resultOffset, 32, result) |
369 | } |
370 | |
371 | /** |
372 | * Halt execution returning output data. |
373 | * @param {integer} offset the offset of the output data. |
374 | * @param {integer} length the length of the output data. |
375 | */ |
376 | return (offset, length) { |
377 | this.environment.returnValue = this.getMemory(offset, length) |
378 | } |
379 | |
380 | /** |
381 | * Halt execution and register account for later deletion giving the remaining |
382 | * balance to an address path |
383 | * @param {integer} offset the offset to load the address from |
384 | */ |
385 | suicide (addressOffset) { |
386 | this.environment.suicideAddress = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
387 | } |
388 | |
389 | getMemory (offset, length) { |
390 | return new Uint8Array(this.module.exports.memory, offset, length) |
391 | } |
392 | |
393 | setMemory (offset, length, value) { |
394 | const memory = new Uint8Array(this.module.exports.memory, offset, length) |
395 | memory.set(value) |
396 | } |
397 | } |
398 | |
399 | // |
400 | // Polyfill required unless this is sorted: https://bugs.chromium.org/p/chromium/issues/detail?id=633895 |
401 | // |
402 | // Polyfill from: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Function/bind |
403 | // |
404 | Function.prototype.bind = function (oThis) { // eslint-disable-line |
405 | if (typeof this !== 'function') { |
406 | // closest thing possible to the ECMAScript 5 |
407 | // internal IsCallable function |
408 | throw new TypeError('Function.prototype.bind - what is trying to be bound is not callable') |
409 | } |
410 | |
411 | var aArgs = Array.prototype.slice.call(arguments, 1) |
412 | var fToBind = this |
413 | var fNOP = function () {} |
414 | var fBound = function () { |
415 | return fToBind.apply(this instanceof fNOP ? this : oThis, |
416 | aArgs.concat(Array.prototype.slice.call(arguments))) |
417 | } |
418 | |
419 | if (this.prototype) { |
420 | // Function.prototype doesn't have a prototype property |
421 | fNOP.prototype = this.prototype |
422 | } |
423 | |
424 | fBound.prototype = new fNOP() // eslint-disable-line new-cap |
425 | |
426 | return fBound |
427 | } |
428 |
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