From 7a1bca95382aa9f1c2fad350d9bf8f75d0edd5de Mon Sep 17 00:00:00 2001
From: IrineSistiana <49315432+IrineSistiana@users.noreply.github.com>
Date: Tue, 9 Feb 2021 00:04:19 +0800
Subject: [PATCH] remove server max_concurrent_queries_pre_client

---
 .../pkg/server_handler/server_handler.go      | 27 +------------------
 dispatcher/plugin/server/server.go            | 14 +++++-----
 2 files changed, 7 insertions(+), 34 deletions(-)

diff --git a/dispatcher/pkg/server_handler/server_handler.go b/dispatcher/pkg/server_handler/server_handler.go
index e0de06372..37b3ba493 100644
--- a/dispatcher/pkg/server_handler/server_handler.go
+++ b/dispatcher/pkg/server_handler/server_handler.go
@@ -53,15 +53,8 @@ type DefaultServerHandlerConfig struct {
 	// If ConcurrentLimit <= 0, means no limit.
 	// When calling DefaultServerHandler.ServeDNS(), if a query exceeds the limit, it will wait on a FIFO queue until
 	// - its ctx is done -> The query will be dropped silently.
-	// - it can be proceed -> Normal procedure.
+	// - it can be proceeded -> Normal procedure.
 	ConcurrentLimit int
-
-	// ConcurrentLimitPreClient controls the max concurrent queries for the pre client.
-	// If ConcurrentLimitPreClient <= 0, means no limit.
-	// It uses qCtx.From() as the identification of clients.
-	// When calling DefaultServerHandler.ServeDNS(), if a client query exceeds the limit,
-	// an REFUSED response will be returned to client.
-	ConcurrentLimitPreClient int
 }
 
 // NewDefaultServerHandler
@@ -73,9 +66,6 @@ func NewDefaultServerHandler(config *DefaultServerHandlerConfig) *DefaultServerH
 		h.limiter = concurrent_limiter.NewConcurrentLimiter(config.ConcurrentLimit)
 	}
 
-	if config.ConcurrentLimitPreClient > 0 {
-		h.clientLimiter = concurrent_limiter.NewClientQueryLimiter(config.ConcurrentLimitPreClient)
-	}
 	return h
 }
 
@@ -89,21 +79,6 @@ func (h *DefaultServerHandler) ServeDNS(ctx context.Context, qCtx *handler.Conte
 		}
 	}
 
-	if h.clientLimiter != nil {
-		addr := qCtx.From()
-		if addr != nil {
-			key := addr.String()
-			if h.clientLimiter.Acquire(key) != true {
-				r := new(dns.Msg)
-				r.SetReply(qCtx.Q())
-				r.Rcode = dns.RcodeRefused
-				write(r)
-				return
-			}
-			defer h.clientLimiter.Done(key)
-		}
-	}
-
 	if h.limiter != nil {
 		select {
 		case <-h.limiter.Wait():
diff --git a/dispatcher/plugin/server/server.go b/dispatcher/plugin/server/server.go
index 816dbd051..d204a47ab 100644
--- a/dispatcher/plugin/server/server.go
+++ b/dispatcher/plugin/server/server.go
@@ -51,10 +51,9 @@ type ServerGroup struct {
 }
 
 type Args struct {
-	Server                        []*Server     `yaml:"server"`
-	Entry                         []interface{} `yaml:"entry"`
-	MaxConcurrentQueries          int           `yaml:"max_concurrent_queries"`
-	MaxConcurrentQueriesPreClient int           `yaml:"max_concurrent_queries_pre_client"`
+	Server               []*Server     `yaml:"server"`
+	Entry                []interface{} `yaml:"entry"`
+	MaxConcurrentQueries int           `yaml:"max_concurrent_queries"`
 }
 
 // Server is not safe for concurrent use.
@@ -106,10 +105,9 @@ func newServerPlugin(bp *handler.BP, args *Args) (*ServerGroup, error) {
 	}
 
 	sh := server_handler.NewDefaultServerHandler(&server_handler.DefaultServerHandlerConfig{
-		Logger:                   bp.L(),
-		Entry:                    ecs,
-		ConcurrentLimit:          args.MaxConcurrentQueries,
-		ConcurrentLimitPreClient: args.MaxConcurrentQueriesPreClient,
+		Logger:          bp.L(),
+		Entry:           ecs,
+		ConcurrentLimit: args.MaxConcurrentQueries,
 	})
 
 	sg := NewServerGroup(bp, sh, args.Server)