94a8b296e4
Here we clean up internal uses of type discover.node, converting most code to use enode.Node instead. The discover.node type used to be the canonical representation of network hosts before ENR was introduced. Most code worked with *node to avoid conversions when interacting with Table methods. Since *node also contains internal state of Table and is a mutable type, using *node outside of Table code is prone to data races. It's also cleaner not having to wrap/unwrap *enode.Node all the time. discover.node has been renamed to tableNode to clarify its purpose. While here, we also change most uses of net.UDPAddr into netip.AddrPort. While this is technically a separate refactoring from the *node -> *enode.Node change, it is more convenient because *enode.Node handles IP addresses as netip.Addr. The switch to package netip in discovery would've happened very soon anyway. The change to netip.AddrPort stops at certain interface points. For example, since package p2p/netutil has not been converted to use netip.Addr yet, we still have to convert to net.IP/net.UDPAddr in a few places.
116 lines
3.5 KiB
Go
116 lines
3.5 KiB
Go
// Copyright 2023 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package discover
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import (
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"net"
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"net/netip"
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"sync"
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"time"
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"github.com/ethereum/go-ethereum/log"
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"github.com/ethereum/go-ethereum/p2p/discover/v5wire"
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"github.com/ethereum/go-ethereum/p2p/enode"
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)
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// This is a limit for the number of concurrent talk requests.
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const maxActiveTalkRequests = 1024
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// This is the timeout for acquiring a handler execution slot for a talk request.
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// The timeout should be short enough to fit within the request timeout.
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const talkHandlerLaunchTimeout = 400 * time.Millisecond
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// TalkRequestHandler callback processes a talk request and returns a response.
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//
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// Note that talk handlers are expected to come up with a response very quickly, within at
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// most 200ms or so. If the handler takes longer than that, the remote end may time out
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// and wont receive the response.
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type TalkRequestHandler func(enode.ID, *net.UDPAddr, []byte) []byte
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type talkSystem struct {
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transport *UDPv5
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mutex sync.Mutex
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handlers map[string]TalkRequestHandler
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slots chan struct{}
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lastLog time.Time
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dropCount int
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}
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func newTalkSystem(transport *UDPv5) *talkSystem {
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t := &talkSystem{
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transport: transport,
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handlers: make(map[string]TalkRequestHandler),
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slots: make(chan struct{}, maxActiveTalkRequests),
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}
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for i := 0; i < cap(t.slots); i++ {
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t.slots <- struct{}{}
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}
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return t
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}
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// register adds a protocol handler.
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func (t *talkSystem) register(protocol string, handler TalkRequestHandler) {
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t.mutex.Lock()
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t.handlers[protocol] = handler
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t.mutex.Unlock()
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}
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// handleRequest handles a talk request.
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func (t *talkSystem) handleRequest(id enode.ID, addr netip.AddrPort, req *v5wire.TalkRequest) {
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t.mutex.Lock()
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handler, ok := t.handlers[req.Protocol]
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t.mutex.Unlock()
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if !ok {
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resp := &v5wire.TalkResponse{ReqID: req.ReqID}
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t.transport.sendResponse(id, addr, resp)
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return
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}
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// Wait for a slot to become available, then run the handler.
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timeout := time.NewTimer(talkHandlerLaunchTimeout)
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defer timeout.Stop()
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select {
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case <-t.slots:
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go func() {
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defer func() { t.slots <- struct{}{} }()
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udpAddr := &net.UDPAddr{IP: addr.Addr().AsSlice(), Port: int(addr.Port())}
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respMessage := handler(id, udpAddr, req.Message)
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resp := &v5wire.TalkResponse{ReqID: req.ReqID, Message: respMessage}
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t.transport.sendFromAnotherThread(id, addr, resp)
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}()
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case <-timeout.C:
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// Couldn't get it in time, drop the request.
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if time.Since(t.lastLog) > 5*time.Second {
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log.Warn("Dropping TALKREQ due to overload", "ndrop", t.dropCount)
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t.lastLog = time.Now()
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t.dropCount++
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}
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case <-t.transport.closeCtx.Done():
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// Transport closed, drop the request.
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}
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}
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// wait blocks until all active requests have finished, and prevents new request
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// handlers from being launched.
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func (t *talkSystem) wait() {
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for i := 0; i < cap(t.slots); i++ {
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<-t.slots
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}
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}
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