Simplify sequencing of handle_query_channel_range

Modify NetGraphMsgHandler::handle_query_channel_range to always use
first_blocknum=0 in replies. This is spec compliant after changes to
make sequence completion explicity using sync_complete.

diff --git a/lightning/src/routing/network_graph.rs b/lightning/src/routing/network_graph.rs
index e11a53b769183cf7bec0bb81c1510cb6565505f7..04e4eb14770aaaf7aed188fbee571fa7e32946b7 100644 (file)
--- a/lightning/src/routing/network_graph.rs
+++ b/lightning/src/routing/network_graph.rs
@@ -374,28 +374,18 @@ impl<C: Deref + Sync + Send, L: Deref + Sync + Send> RoutingMessageHandler for N
                let mut pending_events = self.pending_events.lock().unwrap();
                let batch_count = batches.len();
                for (batch_index, batch) in batches.into_iter().enumerate() {
-                       // Per spec, the initial first_blocknum needs to be <= the query's first_blocknum.
-                       // Use the query's values since we don't use pre-processed reply ranges.
-                       let first_blocknum = if batch_index == 0 {
-                               msg.first_blocknum
-                       }
-                       // Subsequent replies must be >= the last sent first_blocknum. Use the first block
-                       // in the new batch. Batches beyond the first one cannot be empty.
-                       else {
-                               block_from_scid(batch.first().unwrap())
-                       };
-
-                       // Per spec, the last end_blocknum needs to be >= the query's end_blocknum. Last
-                       // reply calculates difference between the query's end_blocknum and the start of the reply.
-                       // Overflow safe since end_blocknum=msg.first_block_num+msg.number_of_blocks and first_blocknum
-                       // will be either msg.first_blocknum or a higher block height.
+                       // Per spec, the initial first_blocknum needs to be <= the query's first_blocknum and subsequent
+                       // must be >= the prior reply. We'll simplify this by using zero since its still spec compliant and
+                       // sequence completion is now explicitly.
+                       let first_blocknum = 0;
+
+                       // Per spec, the final end_blocknum needs to be >= the query's end_blocknum, so we'll use the
+                       // query's value. Prior batches must use the number of blocks that fit into the message. We'll
+                       // base this off the last SCID in the batch since we've somewhat abusing first_blocknum.
                        let number_of_blocks = if batch_index == batch_count-1 {
-                               msg.end_blocknum() - first_blocknum
-                       }
-                       // Prior replies should use the number of blocks that fit into the reply. Overflow
-                       // safe since first_blocknum is always <= last SCID's block.
-                       else {
-                               block_from_scid(batch.last().unwrap()) - first_blocknum + 1
+                               msg.end_blocknum()
+                       } else {
+                               block_from_scid(batch.last().unwrap()) + 1
                        };
 
                        // Only true for the last message in a sequence
@@ -2209,7 +2199,6 @@ mod tests {
 
                // used for testing resumption on same block
                scids.push(scid_from_parts(108001, 1, 0).unwrap());
-               scids.push(scid_from_parts(108001, 2, 0).unwrap());
 
                for scid in scids {
                        let unsigned_announcement = UnsignedChannelAnnouncement {
@@ -2307,8 +2296,8 @@ mod tests {
                        vec![
                                ReplyChannelRange {
                                        chain_hash: chain_hash.clone(),
-                                       first_blocknum: 0xffffff,
-                                       number_of_blocks: 1,
+                                       first_blocknum: 0,
+                                       number_of_blocks: 0x01000000,
                                        sync_complete: true,
                                        short_channel_ids: vec![]
                                },
@@ -2321,15 +2310,15 @@ mod tests {
                        &node_id_2,
                        QueryChannelRange {
                                chain_hash: chain_hash.clone(),
-                               first_blocknum: 0x00800000,
+                               first_blocknum: 1000,
                                number_of_blocks: 1000,
                        },
                        true,
                        vec![
                                ReplyChannelRange {
                                        chain_hash: chain_hash.clone(),
-                                       first_blocknum: 0x00800000,
-                                       number_of_blocks: 1000,
+                                       first_blocknum: 0,
+                                       number_of_blocks: 2000,
                                        sync_complete: true,
                                        short_channel_ids: vec![],
                                }
@@ -2349,8 +2338,8 @@ mod tests {
                        vec![
                                ReplyChannelRange {
                                        chain_hash: chain_hash.clone(),
-                                       first_blocknum: 0xfe0000,
-                                       number_of_blocks: 0xffffffff - 0xfe0000,
+                                       first_blocknum: 0,
+                                       number_of_blocks: 0xffffffff,
                                        sync_complete: true,
                                        short_channel_ids: vec![
                                                0xfffffe_ffffff_ffff, // max
@@ -2372,8 +2361,8 @@ mod tests {
                        vec![
                                ReplyChannelRange {
                                        chain_hash: chain_hash.clone(),
-                                       first_blocknum: 100000,
-                                       number_of_blocks: 8000,
+                                       first_blocknum: 0,
+                                       number_of_blocks: 108000,
                                        sync_complete: true,
                                        short_channel_ids: (100000..=107999)
                                                .map(|block| scid_from_parts(block, 0, 0).unwrap())
@@ -2395,8 +2384,8 @@ mod tests {
                        vec![
                                ReplyChannelRange {
                                        chain_hash: chain_hash.clone(),
-                                       first_blocknum: 100000,
-                                       number_of_blocks: 8000,
+                                       first_blocknum: 0,
+                                       number_of_blocks: 108000,
                                        sync_complete: false,
                                        short_channel_ids: (100000..=107999)
                                                .map(|block| scid_from_parts(block, 0, 0).unwrap())
@@ -2404,8 +2393,8 @@ mod tests {
                                },
                                ReplyChannelRange {
                                        chain_hash: chain_hash.clone(),
-                                       first_blocknum: 108000,
-                                       number_of_blocks: 1,
+                                       first_blocknum: 0,
+                                       number_of_blocks: 108001,
                                        sync_complete: true,
                                        short_channel_ids: vec![
                                                scid_from_parts(108000, 0, 0).unwrap(),
@@ -2427,8 +2416,8 @@ mod tests {
                        vec![
                                ReplyChannelRange {
                                        chain_hash: chain_hash.clone(),
-                                       first_blocknum: 100002,
-                                       number_of_blocks: 8000,
+                                       first_blocknum: 0,
+                                       number_of_blocks: 108002,
                                        sync_complete: false,
                                        short_channel_ids: (100002..=108001)
                                                .map(|block| scid_from_parts(block, 0, 0).unwrap())
@@ -2436,12 +2425,11 @@ mod tests {
                                },
                                ReplyChannelRange {
                                        chain_hash: chain_hash.clone(),
-                                       first_blocknum: 108001,
-                                       number_of_blocks: 1,
+                                       first_blocknum: 0,
+                                       number_of_blocks: 108002,
                                        sync_complete: true,
                                        short_channel_ids: vec![
                                                scid_from_parts(108001, 1, 0).unwrap(),
-                                               scid_from_parts(108001, 2, 0).unwrap(),
                                        ],
                                }
                        ]