Prevents a situation where we (not running snap) connects with a peer running snap, and get stalled waiting for snap registration to succeed (which will never happen), which cause a waitgroup wait to halt shutdown

* eth: check snap satelliteness, delegate drop to eth

* eth: better handle eth/snap satellite relation, merge reg/unreg paths

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>

* eth, p2p: reserve half peer slots for snap peers during snap sync

* eth: less logging

* eth: rework the eth/snap peer reservation logic

* eth: rework the eth/snap peer reservation logic (again)

USB enumeration still occured. Make sure it will only occur if --usb is set.
This also deprecates the 'NoUSB' config file option in favor of a new option 'USB'.

The database panicked for invalid IPs. This is usually no problem
because all code paths leading to node DB access verify the IP, but it's
dangerous because improper validation can turn this panic into a DoS
vulnerability. The quick fix here is to just turn database accesses
using invalid IP into a noop. This isn't great, but I'm planning to
remove the node DB for discv5 long-term, so it should be fine to have
this quick fix for half a year.

Fixes #21849

This PR fixes a deadlock reported here: #21925

The cause is that many operations may be pending, but if the close happens, only one of them gets awoken and exits, the others remain waiting for a signal that never comes.

This fixes a deadlock that could occur when a response packet arrived
after a call had already received enough responses and was about to
signal completion to the dispatch loop.

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

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

* p2p: avoid busy-loop on temporary errors

* p2p: address review concerns

- Remove the ws:// prefix from the status endpoint since
  the ws:// is already included in the stack.WSEndpoint().
- Don't register the services again in the node start.
  Registration is already done in the initialization stage.
- Expose admin namespace via websocket.
  This namespace is necessary for connecting the peers via websocket.
- Offer logging relevant options for exec adapter.
  It's really painful to mix all log output in the single console. So
  this PR offers two additional options for exec adapter in this case
  testers can config the log output(e.g. file output) and log level
  for each p2p node.

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.

This change implements the Discovery v5.1 wire protocol and
also adds an interactive test suite for this protocol.

* peer: return localAddr instead of name to prevent spam

We currently use the name (which can be freely set by the peer) in several log messages.
This enables malicious actors to write spam into your geth log.
This commit returns the localAddr instead of the freely settable name.

* p2p: reduce usage of peer.Name in warn messages

* eth, p2p: use truncated names

* Update peer.go

Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: Felix Lange <fjl@twurst.com>

For some reason, using the shared hash causes a cryptographic incompatibility
when using Go 1.15. I noticed this during the development of Discovery v5.1
when I added test vector verification.

The go library commit that broke this is golang/go@97240d5, but the
way we used HKDF is slightly dodgy anyway and it's not a regression.

This change moves the RLPx protocol implementation into a separate package,
p2p/rlpx. The new package can be used to establish RLPx connections for
protocol testing purposes.

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

This PR adds an extra guarantee to NodeStateMachine: it ensures that all
immediate effects of a certain change are processed before any subsequent
effects of any of the immediate effects on the same node. In the original
version, if a cascaded change caused a subscription callback to be called
multiple times for the same node then these calls might have happened in a
wrong chronological order.

For example:

- a subscription to flag0 changes flag1 and flag2
- a subscription to flag1 changes flag3
- a subscription to flag1, flag2 and flag3 was called in the following order:

   [flag1] -> [flag1, flag3]
   [] -> [flag1]
   [flag1, flag3] -> [flag1, flag2, flag3]

This happened because the tree of changes was traversed in a "depth-first
order". Now it is traversed in a "breadth-first order"; each node has a
FIFO queue for pending callbacks and each triggered subscription callback
is added to the end of the list. The already existing guarantees are
retained; no SetState or SetField returns until the callback queue of the
node is empty again. Just like before, it is the responsibility of the
state machine design to ensure that infinite state loops are not possible.
Multiple changes affecting the same node can still happen simultaneously;
in this case the changes can be interleaved in the FIFO of the node but the
correct order is still guaranteed.

A new unit test is also added to verify callback order in the above scenario.

This change improves discovery behavior in small networks. Very small
networks would often fail to bootstrap because all member nodes were
dropping table content due to findnode failure. The check is now changed
to avoid dropping nodes on findnode failure when their bucket is almost
empty. It also relaxes the liveness check requirement for FINDNODE/v4
response nodes, returning unverified nodes as results when there aren't
any verified nodes yet.

The "findnode failed" log now reports whether the node was dropped
instead of the number of results. The value of the "results" was
always zero by definition.

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

This adds a lock around requests because some routers can't handle
concurrent requests. Requests are also rate-limited.
 
The Map function request a new mapping exactly when the map timeout
occurs instead of 5 minutes earlier. This should prevent duplicate mappings.

This PR significantly changes the APIs for instantiating Ethereum nodes in
a Go program. The new APIs are not backwards-compatible, but we feel that
this is made up for by the much simpler way of registering services on
node.Node. You can find more information and rationale in the design
document: https://gist.github.com/renaynay/5bec2de19fde66f4d04c535fd24f0775.

There is also a new feature in Node's Go API: it is now possible to
register arbitrary handlers on the user-facing HTTP server. In geth, this
facility is used to enable GraphQL.

There is a single minor change relevant for geth users in this PR: The
GraphQL API is no longer available separately from the JSON-RPC HTTP
server. If you want GraphQL, you need to enable it using the
./geth --http --graphql flag combination.

The --graphql.port and --graphql.addr flags are no longer available.

This fixes a corner case in discv5. The issue cannot happen in discv4
because it performs IP checks on all incoming node information.

This moves all v4 protocol definitions to a new package, p2p/discover/v4wire.
The new package will be used for low-level protocol tests.

This PR reimplements the light client server pool. It is also a first step
to move certain logic into a new lespay package. This package will contain
the implementation of the lespay token sale functions, the token buying and
selling logic and other components related to peer selection/prioritization
and service quality evaluation. Over the long term this package will be
reusable for incentivizing future protocols.

Since the LES peer logic is now based on enode.Iterator, it can now use
DNS-based fallback discovery to find servers.

This document describes the function of the new components:
https://gist.github.com/zsfelfoldi/3c7ace895234b7b345ab4f71dab102d4

* p2p: add low port check in dialer

We already have a check like this for UDP ports, add a similar one in
the dialer. This prevents dials to port zero and it's also an extra
layer of protection against spamming HTTP servers.

* p2p/discover: use errLowPort in v4 code

* p2p: change port check

* p2p: add comment

* p2p/simulations/adapters: ensure assigned port is in all node records

It is possible to specify enode URLs using domain name since
commit b90cdbaa, but the code comment still said that only
IP addresses are allowed.

Co-authored-by: admin@komgo.io <KomgoRocks2018!>

This adds two new methods to UDPv5, AllNodes and LocalNode.

AllNodes returns all the nodes stored in the local table; this is
useful for the purposes of metrics collection and also debugging any
potential issues with other discovery v5 implementations.

LocalNode returns the local node object. The reason for exposing this
is so that users can modify and set/delete new key-value entries in
the local record.

This PR adds service value measurement statistics to the light client. It
also adds a private API that makes these statistics accessible. A follow-up
PR will add the new server pool which uses these statistics to select
servers with good performance.

This document describes the function of the new components:
https://gist.github.com/zsfelfoldi/3c7ace895234b7b345ab4f71dab102d4



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

* accounts/scwallet: remove unnecessary uses of fmt.Sprintf

* cmd/puppeth: remove unnecessary uses of fmt.Sprintf

* p2p/discv5: remove unnecessary use of fmt.Sprintf

* whisper/mailserver: remove unnecessary uses of fmt.Sprintf

* core: goimports -w tx_pool_test.go

* eth/downloader: goimports -w downloader_test.go

* build: upgrade to golangci-lint 1.24.0

This adds an implementation of the current discovery v5 spec.

There is full integration with cmd/devp2p and enode.Iterator in this
version. In theory we could enable the new protocol as a replacement of
discovery v4 at any time. In practice, there will likely be a few more
changes to the spec and implementation before this can happen.