p2p: remove unnecessary panic handling in PEX reactor

The message handling in this reactor is all under control of the reactor
itself, and does not call out to callbacks or other externally-supplied code.
It doesn't need to check for panics.

- Remove an irrelevant channel ID check.
- Remove an unnecessary panic recovery wrapper.

internal/p2p/pex/reactor.go

@@ -3,7 +3,6 @@ package pex
 import (
 	"context"
 	"fmt"
-	"runtime/debug"
 	"sync"
 	"time"
 
@@ -192,7 +191,7 @@ func (r *Reactor) processPexCh(ctx context.Context) {
 			}
 
 			// A request from another peer, or a response to one of our requests.
-			dur, err := r.handleMessage(ctx, r.pexCh.ID, envelope)
+			dur, err := r.handlePexMessage(ctx, envelope)
 			if err != nil {
 				r.logger.Error("failed to process message",
 					"ch_id", r.pexCh.ID, "envelope", envelope, "err", err)
@@ -287,28 +286,6 @@ func (r *Reactor) handlePexMessage(ctx context.Context, envelope *p2p.Envelope)
 	}
 }
 
-// handleMessage handles an Envelope sent from a peer on the specified Channel.
-// This method will convert a panic in message handling as an error.
-func (r *Reactor) handleMessage(ctx context.Context, chID p2p.ChannelID, envelope *p2p.Envelope) (_ time.Duration, err error) {
-	defer func() {
-		if e := recover(); e != nil {
-			err = fmt.Errorf("panic in processing message: %v", e)
-			r.logger.Error(
-				"recovering from processing message panic",
-				"err", err,
-				"stack", string(debug.Stack()),
-			)
-		}
-	}()
-
-	r.logger.Debug("received PEX message", "peer", envelope.From)
-
-	if chID == p2p.ChannelID(PexChannel) {
-		return r.handlePexMessage(ctx, envelope)
-	}
-	return 0, fmt.Errorf("unknown channel ID (%d) for envelope (%v)", chID, envelope)
-}
-
 // processPeerUpdate processes a PeerUpdate. For added peers, PeerStatusUp, we
 // send a request for addresses.
 func (r *Reactor) processPeerUpdate(peerUpdate p2p.PeerUpdate) {