From 9e10f582993fc1f48f01c6b57e737c34b84ce4c5 Mon Sep 17 00:00:00 2001 From: protolambda Date: Fri, 18 Jun 2021 02:48:58 +0200 Subject: [PATCH] update networking spec --- specs/sharding/p2p-interface.md | 85 ++++++++++++++++++++------------- 1 file changed, 53 insertions(+), 32 deletions(-) diff --git a/specs/sharding/p2p-interface.md b/specs/sharding/p2p-interface.md index d00321f36..94dd75128 100644 --- a/specs/sharding/p2p-interface.md +++ b/specs/sharding/p2p-interface.md @@ -14,7 +14,7 @@ - [Gossip domain](#gossip-domain) - [Topics and messages](#topics-and-messages) - [Shard blob subnets](#shard-blob-subnets) - - [`shard_blob_{subnet_id}`](#shard_blob_subnet_id) + - [`shard_block_{subnet_id}`](#shard_block_subnet_id) - [Global topics](#global-topics) - [`shard_header`](#shard_header) - [`shard_proposer_slashing`](#shard_proposer_slashing) @@ -34,7 +34,7 @@ The adjustments and additions for Shards are outlined in this document. | Name | Value | Description | | ---- | ----- | ----------- | -| `SHARD_BLOB_SUBNET_COUNT` | `64` | The number of `shard_blob_{subnet_id}` subnets used in the gossipsub protocol. | +| `SHARD_BLOCK_SUBNET_COUNT` | `64` | The number of `shard_block_{subnet_id}` subnets used in the gossipsub protocol. | ## Gossip domain @@ -44,22 +44,22 @@ Following the same scheme as the [Phase0 gossip topics](../phase0/p2p-interface. | Name | Message Type | |----------------------------------|---------------------------| -| `shard_blob_{subnet_id}` | `SignedShardBlob` | -| `shard_header` | `SignedShardBlobHeader` | +| `shard_block_{subnet_id}` | `SignedShardBlock` | +| `shard_block_header` | `SignedShardBlockHeader` | | `shard_proposer_slashing` | `ShardProposerSlashing` | The [DAS network specification](./das-p2p.md) defines additional topics. -#### Shard blob subnets +#### Shard block subnets -Shard blob subnets are used to propagate shard blobs to subsections of the network. +Shard block subnets are used by builders to make their blobs available after selection by shard proposers. -##### `shard_blob_{subnet_id}` +##### `shard_block_{subnet_id}` -Shard block data, in the form of a `SignedShardBlob` is published to the `shard_blob_{subnet_id}` subnets. +Shard block data, in the form of a `SignedShardBlock` is published to the `shard_block_{subnet_id}` subnets. ```python -def compute_subnet_for_shard_blob(state: BeaconState, slot: Slot, shard: Shard) -> uint64: +def compute_subnet_for_shard_block(state: BeaconState, slot: Slot, shard: Shard) -> uint64: """ Compute the correct subnet for a shard blob publication. Note, this mimics compute_subnet_for_attestation(). @@ -69,11 +69,19 @@ def compute_subnet_for_shard_blob(state: BeaconState, slot: Slot, shard: Shard) slots_since_epoch_start = Slot(slot % SLOTS_PER_EPOCH) committees_since_epoch_start = committees_per_slot * slots_since_epoch_start - return uint64((committees_since_epoch_start + committee_index) % SHARD_BLOB_SUBNET_COUNT) + return uint64((committees_since_epoch_start + committee_index) % SHARD_BLOCK_SUBNET_COUNT) ``` -The following validations MUST pass before forwarding the `signed_blob` (with inner `message` as `blob`) on the horizontal subnet or creating samples for it. -- _[IGNORE]_ The `blob` is not from a future slot (with a `MAXIMUM_GOSSIP_CLOCK_DISPARITY` allowance) -- +The following validations MUST pass before forwarding the `signed_block` on the horizontal subnet or creating samples for it. + +We define some aliases to the nested contents of `signed_block`: +```python +block: ShardBlock = signed_block.message +signed_blob: SignedShardBlob = block.signed_blob +blob: ShardBlob = signed_blob.message +``` + +- _[IGNORE]_ The `block` is not from a future slot (with a `MAXIMUM_GOSSIP_CLOCK_DISPARITY` allowance) -- i.e. validate that `blob.slot <= current_slot` (a client MAY queue future blobs for processing at the appropriate slot). - _[IGNORE]_ The `blob` is new enough to be still be processed -- @@ -81,36 +89,49 @@ The following validations MUST pass before forwarding the `signed_blob` (with in - _[REJECT]_ The shard should have a committee at slot -- i.e. validate that `compute_committee_index_from_shard(state, blob.slot, blob.shard)` doesn't raise an error - _[REJECT]_ The shard blob is for the correct subnet -- - i.e. `compute_subnet_for_shard_blob(state, blob.slot, blob.shard) == subnet_id` -- _[IGNORE]_ The blob is the first blob with valid signature received for the `(blob.proposer_index, blob.slot, blob.shard)` combination. -- _[REJECT]_ As already limited by the SSZ list-limit, it is important the blob is well-formatted and not too large. + i.e. `compute_subnet_for_shard_block(state, blob.slot, blob.shard) == subnet_id` +- _[IGNORE]_ The block is the first block with valid signature received for the `(block.proposer_index, blob.slot, blob.shard)` combination. +- _[REJECT]_ The blob is not too large, the data MUST NOT be larger than the SSZ list-limit, and a client MAY be more strict. - _[REJECT]_ The `blob.body.data` MUST NOT contain any point `p >= MODULUS`. Although it is a `uint256`, not the full 256 bit range is valid. -- _[REJECT]_ The proposer signature, `signed_blob.signature`, is valid with respect to the `proposer_index` pubkey. -- _[REJECT]_ The blob is proposed by the expected `proposer_index` for the blob's slot +- _[REJECT]_ The block proposer signature, `signed_block.signature`, is valid with respect to the `proposer_index` pubkey. +- _[REJECT]_ The blob builder exists and has sufficient balance to back the fee payment. +- _[REJECT]_ The blob builder signature, `signed_blob.signature`, is valid with respect to the `builder_index` pubkey. +- _[REJECT]_ The block is proposed by the expected `proposer_index` for the block's slot in the context of the current shuffling (defined by `blob.body.beacon_block_root`/`slot`). If the `proposer_index` cannot immediately be verified against the expected shuffling, - the block MAY be queued for later processing while proposers for the blob's branch are calculated -- + the block MAY be queued for later processing while proposers for the block's branch are calculated -- in such a case _do not_ `REJECT`, instead `IGNORE` this message. #### Global topics -There are two additional global topics for Sharding, one is used to propagate shard blob headers (`shard_header`) to -all nodes on the network. Another one is used to propagate validator message (`shard_proposer_slashing`). +There are two additional global topics for Sharding. -##### `shard_header` +One is used to propagate shard block headers (`shard_block_header`) to all nodes on the network. +Another one is used to propagate shard proposer slashings (`shard_proposer_slashing`). -Shard header data, in the form of a `SignedShardBlobHeader` is published to the global `shard_header` subnet. +##### `shard_block_header` -The following validations MUST pass before forwarding the `signed_shard_blob_header` (with inner `message` as `header`) on the network. -- _[IGNORE]_ The `header` is not from a future slot (with a `MAXIMUM_GOSSIP_CLOCK_DISPARITY` allowance) -- - i.e. validate that `header.slot <= current_slot` +Shard header data, in the form of a `SignedShardBlockHeader` is published to the global `shard_block_header` subnet. +Shard block headers select shard blob bids by builders, and should be timely to ensure builders can publish the full shard block timely. + +The following validations MUST pass before forwarding the `signed_block_header` (with inner `message` as `header`) on the network. + +We define some aliases to the nested contents of `signed_block_header`: +```python +block_header: ShardBlockHeader = signed_block_header.message +signed_blob_header: SignedShardBlobHeader = header.signed_blob_header +blob_header: ShardBlobHeader = signed_blob_header.message +``` + +- _[IGNORE]_ The header is not from a future slot (with a `MAXIMUM_GOSSIP_CLOCK_DISPARITY` allowance) -- + i.e. validate that `blob_header.slot <= current_slot` (a client MAY queue future headers for processing at the appropriate slot). -- _[IGNORE]_ The `header` is new enough to be still be processed -- - i.e. validate that `compute_epoch_at_slot(header.slot) >= get_previous_epoch(state)` -- _[IGNORE]_ The header is the first header with valid signature received for the `(header.proposer_index, header.slot, header.shard)` combination. -- _[REJECT]_ The shard should have a committee at slot -- - i.e. validate that `compute_committee_index_from_shard(state, header.slot, header.shard)` doesn't raise an error -- _[REJECT]_ The proposer signature, `signed_shard_blob_header.signature`, is valid with respect to the `proposer_index` pubkey. +- _[IGNORE]_ The header is new enough to be still be processed -- + i.e. validate that `compute_epoch_at_slot(blob_header.slot) >= get_previous_epoch(state)` +- _[IGNORE]_ The header is the first header with valid signature received for the `(block_header.proposer_index, blob_header.slot, blob_header.shard)` combination. +- _[REJECT]_ The `shard` MUST have a committee at the `slot` -- + i.e. validate that `compute_committee_index_from_shard(state, blob_header.slot, blob_header.shard)` doesn't raise an error +- _[REJECT]_ The proposer signature, `signed_shard_block_header.signature`, is valid with respect to the `block_header.proposer_index` pubkey. - _[REJECT]_ The header is proposed by the expected `proposer_index` for the block's slot in the context of the current shuffling (defined by `header.body_summary.beacon_block_root`/`slot`). If the `proposer_index` cannot immediately be verified against the expected shuffling, @@ -124,6 +145,6 @@ Shard proposer slashings, in the form of `ShardProposerSlashing`, are published The following validations MUST pass before forwarding the `shard_proposer_slashing` on to the network. - _[IGNORE]_ The shard proposer slashing is the first valid shard proposer slashing received - for the proposer with index `proposer_slashing.signed_header_1.message.proposer_index`. + for the proposer with index `proposer_slashing.signed_reference_1.message.proposer_index`. The `slot` and `shard` are ignored, there are no per-shard slashings. - _[REJECT]_ All of the conditions within `process_shard_proposer_slashing` pass validation.