Fix(parachain): Add Fallback for Validation Data Retrieval and Adjust Relay Slot (#959)

* fix(parachain): Add fallback for validation data retrieval and adjust relay slot

Introduces a fallback mechanism to retrieve validation data from the grandparent block if it fails on the parent, which can occur after a wasm override.

Additionally, the relay slot calculation is incremented by an extra `+1` for safety.

* fmt

* update test snapshots

* update test results

Author: xlc

packages/core/src/blockchain/inherent/parachain/validation-data.ts

@@ -4,6 +4,7 @@ import { type BN, hexToU8a, u8aConcat, u8aToHex } from '@polkadot/util'
 import type { HexString } from '@polkadot/util/types'
 import { blake2AsHex, blake2AsU8a } from '@polkadot/util-crypto'
 import _ from 'lodash'
+import { defaultLogger } from '../../../logger.js'
 import { compactHex, getCurrentSlot, getParaId } from '../../../utils/index.js'
 import {
   dmqMqcHead,
@@ -19,6 +20,8 @@ import type { Block } from '../../block.js'
 import type { BuildBlockParams, DownwardMessage, HorizontalMessage } from '../../txpool.js'
 import type { InherentProvider } from '../index.js'
 
+const logger = defaultLogger.child({ name: 'parachain-validation-data' })
+
 const MOCK_VALIDATION_DATA = {
   validationData: {
     relayParentNumber: 1000,
@@ -59,7 +62,7 @@ export type ValidationData = {
   }
 }
 
-const getValidationData = async (parent: Block) => {
+const getValidationData = async (parent: Block, fallback = true): Promise<ValidationData> => {
   const meta = await parent.meta
   if (parent.number === 0) {
     const { trieRootHash, nodes } = await createProof(MOCK_VALIDATION_DATA.relayChainState.trieNodes, [])
@@ -72,17 +75,42 @@ const getValidationData = async (parent: Block) => {
       },
     }
   }
-  const extrinsics = await parent.extrinsics
-  const validationDataExtrinsic = extrinsics.find((extrinsic) => {
-    const firstArg = meta.registry.createType<GenericExtrinsic>('GenericExtrinsic', extrinsic)?.args?.[0]
-    return firstArg && 'validationData' in firstArg
-  })
-  if (!validationDataExtrinsic) {
-    throw new Error('Missing validation data from block')
+  try {
+    const extrinsics = await parent.extrinsics
+    const validationDataExtrinsic = extrinsics.find((extrinsic) => {
+      const firstArg = meta.registry.createType<GenericExtrinsic>('GenericExtrinsic', extrinsic)?.args?.[0]
+      return firstArg && 'validationData' in firstArg
+    })
+    if (!validationDataExtrinsic) {
+      throw new Error('Missing validation data from block')
+    }
+    return meta.registry
+      .createType<GenericExtrinsic>('GenericExtrinsic', validationDataExtrinsic)
+      .args[0].toJSON() as any as ValidationData
+  } catch (e) {
+    logger.warn('Failed to get validation data from block %d %s', parent.number, e)
+
+    if (fallback) {
+      // this could fail due to wasm override that breaks the validation data format
+      // so we will try parent's parent
+      const grandParent = await parent.parentBlock
+      if (grandParent) {
+        const data = await getValidationData(grandParent, false)
+        return {
+          ...data,
+          validationData: {
+            ...data.validationData,
+            relayParentNumber: data.validationData.relayParentNumber + 2,
+          },
+        }
+      } else {
+        throw e
+      }
+    } else {
+      // fallback failed, throw error
+      throw e
+    }
   }
-  return meta.registry
-    .createType<GenericExtrinsic>('GenericExtrinsic', validationDataExtrinsic)
-    .args[0].toJSON() as any as ValidationData
 }
 
 export class SetValidationData implements InherentProvider {
@@ -129,7 +157,8 @@ export class SetValidationData implements InherentProvider {
         const relayCurrentSlot = decoded[key]
           ? meta.registry.createType<Slot>('Slot', hexToU8a(decoded[key])).toNumber()
           : (await getCurrentSlot(parent)) * relaySlotIncrease
-        const newSlot = meta.registry.createType<Slot>('Slot', relayCurrentSlot + relaySlotIncrease)
+        const newSlot = meta.registry.createType<Slot>('Slot', relayCurrentSlot + relaySlotIncrease + 1) // +1 to be safe
+        logger.debug({ relayCurrentSlot, newSlot: newSlot.toNumber() }, 'Updating relay current slot')
         newEntries.push([key, u8aToHex(newSlot.toU8a())])
       } else {
         newEntries.push([key, decoded[key]])

packages/e2e/src/__snapshots__/author.test.ts.snap

@@ -35,11 +35,11 @@ describe('block', async () => {
 
     const head = chain.head
     const newBlock = await chain.newBlock()
-    expect(newBlock.hash).toMatchInlineSnapshot(`"0xfca2b29b2ef3e018b87ce56dfa6200d973201222cbb67dde3aca6db905b440cc"`)
+    expect(newBlock.hash).toMatchInlineSnapshot(`"0xb20b7e701f6a6e9e700a8f81849d59241f7ae51e08260491292f34bc9d06b2ba"`)
 
     await chain.setHead(head)
     await api.tx.system.remark('test').signAndSend(alice)
     const newBlock2 = await chain.newBlock()
-    expect(newBlock2.hash).toMatchInlineSnapshot(`"0xbf570d4c473241efbc4ffe08145e074e3f22b1f40dc2fac8108912bec8ac845e"`)
+    expect(newBlock2.hash).toMatchInlineSnapshot(`"0x9f8ec5d13ff39c5ab53fd8dc3bf2ce3f65bf5ddf86865eb8e9fea904c0bff45d"`)
   })
 })

packages/e2e/src/__snapshots__/chain.test.ts.snap

@@ -104,7 +104,7 @@ describe('dev rpc', async () => {
     expect((await api.rpc.chain.getBlockHash()).toHex()).toBe(hash)
     await dev.setHead(blockNumber - 3)
     expect((await api.rpc.chain.getBlockHash()).toHex()).toMatchInlineSnapshot(
-      `"0xc67fac55f8f2e1ba8f3b7d277d3097fd796216998bd6b1bfd8fd9aed87da579d"`,
+      `"0xa9af3bba23e0ffca832dbaa7fc28d04764d50ccbe52370717dcc5c9126060628"`,
     )
     await dev.setHead(-3)
     expect((await api.rpc.chain.getBlockHash()).toHex()).toMatchInlineSnapshot(

packages/e2e/src/__snapshots__/chopsticks-provider.test.ts.snap

@@ -74,7 +74,7 @@ describe('storage', () => {
 
     tick = next()
     expect(await dev.newBlock()).toMatchInlineSnapshot(
-      `"0x3ee18ba950984f5ed8c6c6d407784c551aea7471ba1000f74998ebd5a3fbc9bf"`,
+      `"0xd93ac4e1814b874c059e647b9726f38c7f42ec673e171572d8e38992f6072b77"`,
     )
     await tick
 
@@ -84,7 +84,7 @@ describe('storage', () => {
     unsub()
 
     expect(await dev.newBlock()).toMatchInlineSnapshot(
-      `"0x1950829c5687d921d786c184dae9eb20ae55d2020b07adafcb1cfb1a5be4212f"`,
+      `"0xf9c6e17a227e188f64338f72626f44a84a55c3b959d9305db309bbed05f76de1"`,
     )
 
     await delay(100)

packages/e2e/src/block.test.ts

@@ -35,7 +35,7 @@ test.describe('index', () => {
       })
       return block.result.hash
     })
-    expect(savedHash).toBe('0x7403a6c53702bfbace9737a5b3cc84fd02d5f8b30259e718455738ae841d992b')
+    expect(savedHash).toBe('0x64809750cb08df1076b3470ce42a0d1e1d45984d59bcfc876ce2d3424fd5416d')
   })
 
   test('dry run extrinsic', async ({ page }) => {
@@ -63,14 +63,14 @@ test.describe('index', () => {
     expect(hightestBlock).toEqual(
       expect.objectContaining({
         number: 4_000_002,
-        hash: '0x9db1dc9525d7574ad6aed6b4302c9fb5069c5cd35288d97ebc78a58782f57b0d',
+        hash: '0xe8657fc0154874e9412aea2c3567743d257384795d99719b900d628763ffb760',
       }),
     )
     const blockByNumber = await page.evaluate(() => globalThis.chain.db?.queryBlockByNumber(4_000_001))
     expect(blockByNumber).toEqual(
       expect.objectContaining({
         number: 4_000_001,
-        hash: '0x7403a6c53702bfbace9737a5b3cc84fd02d5f8b30259e718455738ae841d992b',
+        hash: '0x64809750cb08df1076b3470ce42a0d1e1d45984d59bcfc876ce2d3424fd5416d',
       }),
     )
     const blocksCount = await page.evaluate(() => globalThis.chain.db?.blocksCount())
@@ -87,7 +87,7 @@ test.describe('index', () => {
       expect(hightestBlock).toEqual(
         expect.objectContaining({
           number: 4_000_001,
-          hash: '0x7403a6c53702bfbace9737a5b3cc84fd02d5f8b30259e718455738ae841d992b',
+          hash: '0x64809750cb08df1076b3470ce42a0d1e1d45984d59bcfc876ce2d3424fd5416d',
         }),
       )
     }