increase udpme receive buf when needed

IrineSistiana · IrineSistiana · commit 1ec9102f240a · 2022-03-15T19:53:36.000+08:00
diff --git a/upstream.go b/upstream.go
@@ -43,6 +43,9 @@ func (u *upstream) exchangeOPTM(m *dns.Msg) (*dns.Msg, error) {
 	}
 	defer c.Close()
 	c.SetDeadline(time.Now().Add(time.Second * 3))
+	if opt := m.IsEdns0(); opt != nil {
+		c.UDPSize = opt.UDPSize()
+	}
 	if err := c.WriteMsg(m); err != nil {
 		return nil, err
 	}

Original file line number	Diff line number	Diff line change
`@@ -43,6 +43,9 @@ func (u upstream) exchangeOPTM(m dns.Msg) (*dns.Msg, error) {`
`43`	`43`	`}`
`44`	`44`	`defer c.Close()`
`45`	`45`	`c.SetDeadline(time.Now().Add(time.Second * 3))`
	`46`	`+ if opt := m.IsEdns0(); opt != nil {`
	`47`	`+ c.UDPSize = opt.UDPSize()`
	`48`	`+ }`
`46`	`49`	`if err := c.WriteMsg(m); err != nil {`
`47`	`50`	`return nil, err`
`48`	`51`	`}`