* eth/state, les/state: properly init statedb accesslist when tracing, fixes #22475

* eth: review comments

* eth/tracers: fix compilation err

* eth/tracers: apply @karalabe's suggested fix

* les: add trailing slash to metric namespace

* les: omit '.' in metric namespace

This PR implements the first one of the "lespay" UDP queries which
is already useful in itself: the capacity query. The server pool is making
use of this query by doing a cheap UDP query to determine whether it is
worth starting the more expensive TCP connection process.

* les: move serverPool to les/vflux/client

* les: add metrics

* les: moved ValueTracker inside ServerPool

* les: protect against node registration before server pool is started

* les/vflux/client: fixed tests

* les: make peer registration safe

This adds support for EIP-2718 typed transactions as well as EIP-2930
access list transactions (tx type 1). These EIPs are scheduled for the
Berlin fork.

There very few changes to existing APIs in core/types, and several new APIs
to deal with access list transactions. In particular, there are two new
constructor functions for transactions: types.NewTx and types.SignNewTx.
Since the canonical encoding of typed transactions is not RLP-compatible,
Transaction now has new methods for encoding and decoding: MarshalBinary
and UnmarshalBinary.

The existing EIP-155 signer does not support the new transaction types.
All code dealing with transaction signatures should be updated to use the
newer EIP-2930 signer. To make this easier for future updates, we have
added new constructor functions for types.Signer: types.LatestSigner and
types.LatestSignerForChainID. 

This change also adds support for the YoloV3 testnet.

Co-authored-by: Martin Holst Swende <martin@swende.se>
Co-authored-by: Felix Lange <fjl@twurst.com>
Co-authored-by: Ryan Schneider <ryanleeschneider@gmail.com>

Transaction unindexing will be enabled by default as of 1.10, which causes tx status retrieval will be broken without this PR. 

This PR introduces a retry mechanism in TxStatus retrieval.

This PR adds a more CLI flag, so that the les-server can serve light clients even the local node is not synced yet.

This functionality is needed in some testing environments(e.g. hive). After launching the les server, no more blocks will be imported so the node is always marked as "non-synced".

This PR prevents users from submitting transactions without EIP-155 enabled. This behaviour can be overridden by specifying the flag --rpc.allow-unprotected-txs=true. 

* les: refactored server handler

* tests/fuzzers/les: add fuzzer for les server handler

* tests, les: update les fuzzer

tests: update les fuzzer

tests/fuzzer/les: release resources

tests/fuzzer/les: pre-initialize all resources

* les: refactored server handler and fuzzer

Co-authored-by: rjl493456442 <garyrong0905@gmail.com>

* les/lespay/server: fix balance expiration and add test

* les: move client balances to a new db

* les: rename lespayDb to lesDb

This moves the eth config definition into a separate package, eth/ethconfig. 
Packages eth and les can now import this common package instead of
importing eth from les, reducing dependencies.

Co-authored-by: Felix Lange <fjl@twurst.com>

The PR makes use of the stacktrie, which is is more lenient on resource consumption, than the regular trie, in cases where we only need it for DeriveSha

* les/utils: Limiter

* les/utils: dropped prior weight vs variable cost logic, using fixed weights

* les/utils: always create node selector in addressGroup

* les/utils: renamed request weight to request cost

* les/utils: simplified and improved the DoS penalty mechanism

* les/utils: minor fixes

* les/utils: made selection weight calculation nicer

* les/utils: fixed linter warning

* les/utils: more precise and reliable probabilistic test

* les/utils: fixed linter warning

This PR enables running the new discv5 protocol in both LES client
and server mode. In client mode it mixes discv5 and dnsdisc iterators
(if both are enabled) and filters incoming ENRs for "les" tag and fork ID.
The old p2p/discv5 package and all references to it are removed.

Co-authored-by: Felix Lange <fjl@twurst.com>

This moves the tracing RPC API implementation to package eth/tracers.
By doing so, package eth no longer depends on tracing and the duktape JS engine.

The change also enables tracing using the light client. All tracing methods work with the
light client, but it's a lot slower compared to using a full node.

This fixes #22131 and adds a test reproducing the issue.

This PR introduces a new config field SyncFromCheckpoint for light client.

In some special scenarios, it's required to start synchronization from some
arbitrary checkpoint or even from the scratch. So this PR offers this
flexibility to users so that the synchronization start point can be configured.

There are two relevant configs: SyncFromCheckpoint and Checkpoint.

- If the SyncFromCheckpoint is true, the light client will try to sync from the
  specified checkpoint.

- If the Checkpoint is not configured, then the light client will sync from the
  scratch(from the latest header if the database is not empty)

Additional notes: these two configs are not visible in the CLI flags but only
accessable in the config file.

Example Usage:

[Eth]
SyncFromCheckpoint = true

[Eth.Checkpoint]
SectionIndex = 100
SectionHead = "0xabc"
CHTRoot = "0xabc"
BloomRoot = "0xabc"

PS. Historical checkpoint can be retrieved from the synced full node or light
client via les_getCheckpoint API.

This PR has two changes in the les protocol:

- the auxRoot is not supported. See ethereum/devp2p#171 for more information
- the empty response will be returned in GetHelperTrieProofsMsg request if the merkle
   proving is failed. note, for backward compatibility, the empty merkle proof as well as
   the request auxiliary data will still be returned in  les2/3 protocol no matter the proving
   is successful or not. the proving failure can happen e.g. request the proving for a
   non-included entry in helper trie (unstable header).

During the snap and eth refactor, the net_version rpc call was falsely deprecated.
This restores the net_version RPC handler as most eth2 nodes and other software
depend on it.

* les: allow tx unindexing in les/4 light server mode

* les: minor fixes

* les: more small fixes

* les: add meaningful constants for recentTxIndex handshake field

This commit splits the eth package, separating the handling of eth and snap protocols. It also includes the capability to run snap sync (https://github.com/ethereum/devp2p/blob/master/caps/snap.md

) , but does not enable it by default. 

Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Martin Holst Swende <martin@swende.se>

This PR implements unclean shutdown marker. Every time geth boots, it adds a timestamp to a list of timestamps in the database. This list is capped at 10. At a clean shutdown, the timestamp is removed again. 
Thus, when geth exits unclean, the marker remains, and at boot up we show the most recent unclean shutdowns to the user, which makes it easier to diagnose root-causes to certain problems. 

Co-authored-by: Nagy Salem <me@muhnagy.com>

The previous fix #21960 converted the float to an intermediate signed int, before attempting the uint conversion. Although this works, this doesn't guarantee that other architectures will work the same.

* les: introduce forkID

* les: address comment

* les, light: remove untrusted header retrieval in ODR

* les: polish

* light: check the hash equality in odr

This commit enables users to specify which signer they want to use while creating their transactOpts.
Previously all contract interactions used the homestead signer. Now a user can specify whether they
want to sign with homestead or EIP155 and specify the chainID which adds another layer of security.

Closes #16484

* les: revert arm float bug workaround to check go 1.15

* add traces to reproduce outside travis

* simpler workaround

Changes:

    Simplify nested complexity
    If an if blocks ends with a return statement then remove the else nesting.

Most of the changes has also been reported in golint https://goreportcard.com/report/github.com/ethereum/go-ethereum#golint

Also fixes a bug in les/flowcontrol that caused the overflow.

* all: core: split vm.Config into BlockConfig and TxConfig

* core: core/vm: reset EVM between tx in block instead of creating new

* core/vm: added docs

This adds a few tiny fixes for les and the p2p simulation framework:

LES Parts

- Keep the LES-SERVER connection even it's non-synced

  We had this idea to reject the connections in LES protocol if the les-server itself is
  not synced. However, in LES protocol we will also receive the connection from another
  les-server. In this case even the local node is not synced yet, we should keep the tcp
  connection for other protocols(e.g. eth protocol).

- Don't count "invalid message" for non-existing GetBlockHeadersMsg request

  In the eth syncing mechanism (full sync, fast sync, light sync), it will try to fetch
  some non-existent blocks or headers(to ensure we indeed download all the missing chain).
  In this case, it's possible that the les-server will receive the request for
  non-existent headers. So don't count it as the "invalid message" for scheduling
  dropping.

- Copy the announce object in the closure

  Before the les-server pushes the latest headers to all connected clients, it will create
  a closure and queue it in the underlying request scheduler. In some scenarios it's
  problematic. E.g, in private networks, the block can be mined very fast. So before the
  first closure is executed, we may already update the latest_announce object. So actually
  the "announce" object we want to send is replaced.

  The downsize is the client will receive two announces with the same td and then drop the
  server.

P2P Simulation Framework

- Don't double register the protocol services in p2p-simulation "Start".

  The protocols upon the devp2p are registered in the "New node stage". So don't reigster
  them again when starting a node in the p2p simulation framework

- Add one more new config field "ExternalSigner", in order to use clef service in the
  framework.