From 3a7dffbe09e77570b22d7a8ed4ca3f67a6b14bcc Mon Sep 17 00:00:00 2001
From: nymkappa <1612910616@pm.me>
Date: Tue, 6 Dec 2022 10:51:01 +0100
Subject: [PATCH] Fix crash when channel short id is not valid

---
 .../clightning/clightning-convert.ts          | 26 +++++++++++++------
 .../tasks/lightning/network-sync.service.ts   |  3 +++
 .../sync-tasks/funding-tx-fetcher.ts          |  7 ++++-
 3 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/backend/src/api/lightning/clightning/clightning-convert.ts b/backend/src/api/lightning/clightning/clightning-convert.ts
index 92ae1f0a7..817a36e1f 100644
--- a/backend/src/api/lightning/clightning/clightning-convert.ts
+++ b/backend/src/api/lightning/clightning/clightning-convert.ts
@@ -54,11 +54,12 @@ export async function convertAndmergeBidirectionalChannels(clChannels: any[]): P
       clChannelsDict[clChannel.short_channel_id] = clChannel;
       clChannelsDictCount[clChannel.short_channel_id] = 1;
     } else {
-      consolidatedChannelList.push(
-        await buildFullChannel(clChannel, clChannelsDict[clChannel.short_channel_id])
-      );
-      delete clChannelsDict[clChannel.short_channel_id];
-      clChannelsDictCount[clChannel.short_channel_id]++;
+      const fullChannel = await buildFullChannel(clChannel, clChannelsDict[clChannel.short_channel_id]);
+      if (fullChannel !== null) {
+        consolidatedChannelList.push(fullChannel);
+        delete clChannelsDict[clChannel.short_channel_id];
+        clChannelsDictCount[clChannel.short_channel_id]++;
+      }
     }
 
     const elapsedSeconds = Math.round((new Date().getTime() / 1000) - loggerTimer);
@@ -73,7 +74,10 @@ export async function convertAndmergeBidirectionalChannels(clChannels: any[]): P
   channelProcessed = 0;
   const keys = Object.keys(clChannelsDict);
   for (const short_channel_id of keys) {
-    consolidatedChannelList.push(await buildIncompleteChannel(clChannelsDict[short_channel_id]));
+    const incompleteChannel = await buildIncompleteChannel(clChannelsDict[short_channel_id]);
+    if (incompleteChannel !== null) {
+      consolidatedChannelList.push(incompleteChannel);
+    }
 
     const elapsedSeconds = Math.round((new Date().getTime() / 1000) - loggerTimer);
     if (elapsedSeconds > 10) {
@@ -91,10 +95,13 @@ export async function convertAndmergeBidirectionalChannels(clChannels: any[]): P
  * Convert two clightning "getchannels" entries into a full a lnd "describegraph.edges" format
  * In this case, clightning knows the channel policy for both nodes
  */
-async function buildFullChannel(clChannelA: any, clChannelB: any): Promise<ILightningApi.Channel> {
+async function buildFullChannel(clChannelA: any, clChannelB: any): Promise<ILightningApi.Channel | null> {
   const lastUpdate = Math.max(clChannelA.last_update ?? 0, clChannelB.last_update ?? 0);
 
   const tx = await FundingTxFetcher.$fetchChannelOpenTx(clChannelA.short_channel_id);
+  if (!tx) {
+    return null;
+  }
   const parts = clChannelA.short_channel_id.split('x');
   const outputIdx = parts[2];
 
@@ -114,8 +121,11 @@ async function buildFullChannel(clChannelA: any, clChannelB: any): Promise<ILigh
  * Convert one clightning "getchannels" entry into a full a lnd "describegraph.edges" format
  * In this case, clightning knows the channel policy of only one node
  */
-async function buildIncompleteChannel(clChannel: any): Promise<ILightningApi.Channel> {
+async function buildIncompleteChannel(clChannel: any): Promise<ILightningApi.Channel | null> {
   const tx = await FundingTxFetcher.$fetchChannelOpenTx(clChannel.short_channel_id);
+  if (!tx) {
+    return null;
+  }
   const parts = clChannel.short_channel_id.split('x');
   const outputIdx = parts[2];
 
diff --git a/backend/src/tasks/lightning/network-sync.service.ts b/backend/src/tasks/lightning/network-sync.service.ts
index c5e5a102d..3f66df9d2 100644
--- a/backend/src/tasks/lightning/network-sync.service.ts
+++ b/backend/src/tasks/lightning/network-sync.service.ts
@@ -208,6 +208,9 @@ class NetworkSyncService {
       const channels = await channelsApi.$getChannelsWithoutCreatedDate();
       for (const channel of channels) {
         const transaction = await fundingTxFetcher.$fetchChannelOpenTx(channel.short_id);
+        if (!transaction) {
+          continue;
+        }
         await DB.query(`
           UPDATE channels SET created = FROM_UNIXTIME(?) WHERE channels.id = ?`,
           [transaction.timestamp, channel.id]
diff --git a/backend/src/tasks/lightning/sync-tasks/funding-tx-fetcher.ts b/backend/src/tasks/lightning/sync-tasks/funding-tx-fetcher.ts
index 76865dc40..2de5b7628 100644
--- a/backend/src/tasks/lightning/sync-tasks/funding-tx-fetcher.ts
+++ b/backend/src/tasks/lightning/sync-tasks/funding-tx-fetcher.ts
@@ -70,7 +70,7 @@ class FundingTxFetcher {
     this.running = false;
   }
   
-  public async $fetchChannelOpenTx(channelId: string): Promise<{timestamp: number, txid: string, value: number}> {
+  public async $fetchChannelOpenTx(channelId: string): Promise<{timestamp: number, txid: string, value: number} | null> {
     channelId = Common.channelIntegerIdToShortId(channelId);
 
     if (this.fundingTxCache[channelId]) {
@@ -101,6 +101,11 @@ class FundingTxFetcher {
     const rawTx = await bitcoinClient.getRawTransaction(txid);
     const tx = await bitcoinClient.decodeRawTransaction(rawTx);
 
+    if (!tx || !tx.vout || tx.vout.length < parseInt(outputIdx, 10) + 1 || tx.vout[outputIdx].value === undefined) {
+      logger.err(`Cannot find blockchain funding tx for channel id ${channelId}. Possible reasons are: bitcoin backend timeout or the channel shortId is not valid`);
+      return null;
+    }
+
     this.fundingTxCache[channelId] = {
       timestamp: block.time,
       txid: txid,