Merge pull request #3625 from Agoric/3442-activity-hash

expose hash of kernel state changes as "activityhash"

packages/SwingSet/src/controller.js

@@ -12,6 +12,7 @@ import { assert, details as X } from '@agoric/assert';
 import { importBundle } from '@agoric/import-bundle';
 import { xsnap, recordXSnap } from '@agoric/xsnap';
 
+import { createSHA256 } from './hasher.js';
 import engineGC from './engine-gc.js';
 import { WeakRef, FinalizationRegistry } from './weakref.js';
 import { startSubprocessWorker } from './spawnSubprocessWorker.js';
@@ -271,6 +272,7 @@ export async function makeSwingsetController(
     WeakRef,
     FinalizationRegistry,
     gcAndFinalize: makeGcAndFinalize(engineGC),
+    createSHA256,
   };
 
   const kernelOptions = { verbose, warehousePolicy, overrideVatManagerOptions };
@@ -327,6 +329,10 @@ export async function makeSwingsetController(
       return defensiveCopy(kernel.getStatus());
     },
 
+    getActivityhash() {
+      return kernel.getActivityhash();
+    },
+
     pinVatRoot(vatName) {
       const vatID = kernel.vatNameToID(vatName);
       const kref = kernel.getRootObject(vatID);

packages/SwingSet/src/hasher.js

@@ -0,0 +1,32 @@
+import { assert } from '@agoric/assert';
+
+import { createHash } from 'crypto';
+
+/**
+ * @typedef { (initial: string?) => {
+ *             add: (more: string) => void,
+ *             finish: () => string,
+ *            }
+ *          } CreateSHA256
+ */
+
+/** @type { CreateSHA256 } */
+function createSHA256(initial = undefined) {
+  const hash = createHash('sha256');
+  let done = false;
+  function add(more) {
+    assert(!done);
+    hash.update(more);
+  }
+  function finish() {
+    assert(!done);
+    done = true;
+    return hash.digest('hex');
+  }
+  if (initial) {
+    add(initial);
+  }
+  return harden({ add, finish });
+}
+harden(createSHA256);
+export { createSHA256 };

packages/SwingSet/src/kernel/initializeKernel.js

@@ -2,11 +2,11 @@
 
 import { makeMarshal, Far } from '@agoric/marshal';
 import { assert, details as X } from '@agoric/assert';
+import { createSHA256 } from '../hasher.js';
 import { assertKnownOptions } from '../assertOptions.js';
 import { insistVatID } from './id.js';
 import { makeVatSlot } from '../parseVatSlots.js';
 import { insistStorageAPI } from '../storageAPI.js';
-import { wrapStorage } from './state/storageWrapper.js';
 import makeKernelKeeper from './state/kernelKeeper.js';
 import { exportRootObject, doQueueToKref } from './kernel.js';
 
@@ -16,12 +16,10 @@ function makeVatRootObjectSlot() {
 
 export function initializeKernel(config, hostStorage, verbose = false) {
   const logStartup = verbose ? console.debug : () => 0;
+  insistStorageAPI(hostStorage.kvStore);
 
-  const { kvStore, streamStore } = hostStorage;
-  insistStorageAPI(kvStore);
-  const { enhancedCrankBuffer, commitCrank } = wrapStorage(kvStore);
-
-  const kernelKeeper = makeKernelKeeper(enhancedCrankBuffer, streamStore);
+  const kernelSlog = null;
+  const kernelKeeper = makeKernelKeeper(hostStorage, kernelSlog, createSHA256);
 
   const wasInitialized = kernelKeeper.getInitialized();
   assert(!wasInitialized);
@@ -86,7 +84,7 @@ export function initializeKernel(config, hostStorage, verbose = false) {
         const kref = exportRootObject(kernelKeeper, vatID);
         // Pin, to prevent it being GC'd when only the kvStore points to it
         kernelKeeper.pinObject(kref);
-        kvStore.set('vatAdminRootKref', kref);
+        kernelKeeper.kvStore.set('vatAdminRootKref', kref);
         gotVatAdminRootKref = true;
       }
     }
@@ -135,7 +133,7 @@ export function initializeKernel(config, hostStorage, verbose = false) {
   }
   kernelKeeper.setInitialized();
   kernelKeeper.saveStats();
-  commitCrank(); // commit initialized kernel state as crank #0
+  kernelKeeper.commitCrank(); // commit initialized kernel state as crank #0
   return bootstrapResultKpid;
 
   // ----------------------------------------------------------------------

packages/SwingSet/src/kernel/kernel.js

@@ -7,12 +7,10 @@ import { foreverPolicy } from '../runPolicies.js';
 import { makeVatManagerFactory } from './vatManager/factory.js';
 import { makeVatWarehouse } from './vatManager/vat-warehouse.js';
 import makeDeviceManager from './deviceManager.js';
-import { wrapStorage } from './state/storageWrapper.js';
 import makeKernelKeeper from './state/kernelKeeper.js';
 import { kdebug, kdebugEnable, legibilizeMessageArgs } from './kdebug.js';
 import { insistKernelType, parseKernelSlot } from './parseKernelSlots.js';
 import { parseVatSlot } from '../parseVatSlots.js';
-import { insistStorageAPI } from '../storageAPI.js';
 import { insistCapData } from '../capdata.js';
 import { insistMessage, insistVatDeliveryResult } from '../message.js';
 import { insistDeviceID, insistVatID } from './id.js';
@@ -128,6 +126,7 @@ export default function buildKernel(
     WeakRef,
     FinalizationRegistry,
     gcAndFinalize,
+    createSHA256,
   } = kernelEndowments;
   deviceEndowments = { ...deviceEndowments }; // copy so we can modify
   const {
@@ -138,25 +137,13 @@ export default function buildKernel(
   } = kernelOptions;
   const logStartup = verbose ? console.debug : () => 0;
 
-  const {
-    kvStore,
-    streamStore,
-    snapStore,
-  } = /** @type { HostStore } */ (hostStorage);
-  insistStorageAPI(kvStore);
-  const { enhancedCrankBuffer, abortCrank, commitCrank } = wrapStorage(kvStore);
-  const vatAdminRootKref = kvStore.get('vatAdminRootKref');
+  const vatAdminRootKref = hostStorage.kvStore.get('vatAdminRootKref');
 
   const kernelSlog = writeSlogObject
     ? makeSlogger(slogCallbacks, writeSlogObject)
     : makeDummySlogger(slogCallbacks, makeConsole);
 
-  const kernelKeeper = makeKernelKeeper(
-    enhancedCrankBuffer,
-    streamStore,
-    kernelSlog,
-    snapStore,
-  );
+  const kernelKeeper = makeKernelKeeper(hostStorage, kernelSlog, createSHA256);
 
   let started = false;
 
@@ -261,7 +248,6 @@ export default function buildKernel(
 
   const kernelSyscallHandler = makeKernelSyscallHandler({
     kernelKeeper,
-    kvStore: enhancedCrankBuffer,
     ephemeral,
     // eslint-disable-next-line no-use-before-define
     notify,
@@ -792,7 +778,7 @@ export default function buildKernel(
         const { vatID, shouldReject, info } = terminationTrigger;
         if (terminationTrigger.shouldAbortCrank) {
           // errors unwind any changes the vat made
-          abortCrank();
+          kernelKeeper.abortCrank();
           didAbort = true;
           // but metering deductions and underflow notifications must survive
           const { meterDeductions } = postAbortActions;
@@ -813,7 +799,7 @@ export default function buildKernel(
       }
       kernelKeeper.processRefcounts();
       kernelKeeper.saveStats();
-      commitCrank();
+      kernelKeeper.commitCrank();
       kernelKeeper.incrementCrankNumber();
     } finally {
       processQueueRunning = undefined;
@@ -1221,6 +1207,10 @@ export default function buildKernel(
       });
     },
 
+    getActivityhash() {
+      return kernelKeeper.getActivityhash();
+    },
+
     dump() {
       // note: dump().log is not deterministic, since log() does not go
       // through the syscall interface (and we replay transcripts one vat at

packages/SwingSet/src/kernel/kernelSyscall.js

@@ -28,13 +28,14 @@ export function doSend(kernelKeeper, target, msg) {
 export function makeKernelSyscallHandler(tools) {
   const {
     kernelKeeper,
-    kvStore,
     ephemeral,
     notify,
     doResolve,
     setTerminationTrigger,
   } = tools;
 
+  const { kvStore } = kernelKeeper;
+
   function send(target, msg) {
     return doSend(kernelKeeper, target, msg);
   }

packages/SwingSet/src/kernel/state/kernelKeeper.js

@@ -1,10 +1,14 @@
 // @ts-check
 import { Nat } from '@agoric/nat';
 import { assert, details as X } from '@agoric/assert';
+import { wrapStorage } from './storageWrapper.js';
 import { initializeVatState, makeVatKeeper } from './vatKeeper.js';
 import { initializeDeviceState, makeDeviceKeeper } from './deviceKeeper.js';
 import { parseReachableAndVatSlot } from './reachable.js';
-import { insistEnhancedStorageAPI } from '../../storageAPI.js';
+import {
+  insistStorageAPI,
+  insistEnhancedStorageAPI,
+} from '../../storageAPI.js';
 import {
   insistKernelType,
   makeKernelSlot,
@@ -27,6 +31,10 @@ const enableKernelGC = true;
 // "prefix." and "prefix/", which avoids including anything using an
 // extension of the prefix (e.g. [vat1.foo, vat1.bar, vat15.baz]).
 //
+// The 'local.' namespace is excluded from the kernel activity hash, and is
+// allowed to vary between instances in a consensus machine. Everything else
+// is required to be deterministic.
+//
 // The schema is:
 //
 // vat.names = JSON([names..])
@@ -55,13 +63,14 @@ const enableKernelGC = true;
 // v$NN.vs.$key = string
 // v$NN.meter = m$NN
 // exclude from consensus
-// v$NN.lastSnapshot = JSON({ snapshotID, startPos })
+// local.v$NN.lastSnapshot = JSON({ snapshotID, startPos })
 
 // m$NN.remaining = $NN // remaining capacity (in computrons) or 'unlimited'
 // m$NN.threshold = $NN // notify when .remaining first drops below this
 
 // exclude from consensus
-// snapshot.$id = [vatID, ...]
+// local.snapshot.$id = [vatID, ...]
+// local.kernelStats // JSON(various kernel stats)
 
 // d$NN.o.nextID = $NN
 // d$NN.c.$kernelSlot = $deviceSlot = o-$NN/d+$NN/d-$NN
@@ -125,18 +134,41 @@ const FIRST_CRANK_NUMBER = 0n;
 const FIRST_METER_ID = 1n;
 
 /**
- * @param {KVStorePlus} kvStore
- * @param {StreamStore} streamStore
+ * @param {HostStore} hostStorage
  * @param {KernelSlog} kernelSlog
- * @param {SnapStore=} snapStore
+ * @param {import('../../hasher.js').CreateSHA256} createSHA256
  */
 export default function makeKernelKeeper(
-  kvStore,
-  streamStore,
+  hostStorage,
   kernelSlog,
-  snapStore = undefined,
+  createSHA256,
 ) {
+  // the kernelKeeper wraps the host's raw key-value store in a crank buffer
+  const rawKVStore = hostStorage.kvStore;
+  insistStorageAPI(rawKVStore);
+
+  /**
+   * @param { string } key
+   * @returns { boolean }
+   */
+  function isConsensusKey(key) {
+    if (key.startsWith('local.')) {
+      return false;
+    }
+    return true;
+  }
+
+  const { abortCrank, commitCrank, enhancedCrankBuffer: kvStore } = wrapStorage(
+    rawKVStore,
+    createSHA256,
+    isConsensusKey,
+  );
   insistEnhancedStorageAPI(kvStore);
+  const { streamStore, snapStore } = hostStorage;
+
+  function getActivityhash() {
+    return rawKVStore.get('activityhash');
+  }
 
   /**
    * @param {string} key
@@ -199,11 +231,14 @@ export default function makeKernelKeeper(
   }
 
   function saveStats() {
-    kvStore.set('kernelStats', JSON.stringify(kernelStats));
+    kvStore.set('local.kernelStats', JSON.stringify(kernelStats));
   }
 
   function loadStats() {
-    kernelStats = { ...kernelStats, ...JSON.parse(getRequired('kernelStats')) };
+    kernelStats = {
+      ...kernelStats,
+      ...JSON.parse(getRequired('local.kernelStats')),
+    };
   }
 
   function getStats() {
@@ -1329,6 +1364,11 @@ export default function makeKernelKeeper(
     allocateDeviceIDForNameIfNeeded,
     allocateDeviceKeeperIfNeeded,
 
+    kvStore,
+    abortCrank,
+    commitCrank,
+    getActivityhash,
+
     dump,
   });
 }