github.com/aigarnetwork/aigar@v0.0.0-20191115204914-d59a6eb70f8e/p2p/netutil/error_test.go (about)

     1  //  Copyright 2018 The go-ethereum Authors
     2  //  Copyright 2019 The go-aigar Authors
     3  //  This file is part of the go-aigar library.
     4  //
     5  //  The go-aigar library is free software: you can redistribute it and/or modify
     6  //  it under the terms of the GNU Lesser General Public License as published by
     7  //  the Free Software Foundation, either version 3 of the License, or
     8  //  (at your option) any later version.
     9  //
    10  //  The go-aigar library is distributed in the hope that it will be useful,
    11  //  but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    13  //  GNU Lesser General Public License for more details.
    14  //
    15  //  You should have received a copy of the GNU Lesser General Public License
    16  //  along with the go-aigar library. If not, see <http://www.gnu.org/licenses/>.
    17  
    18  package netutil
    19  
    20  import (
    21  	"net"
    22  	"testing"
    23  	"time"
    24  )
    25  
    26  // This test checks that isPacketTooBig correctly identifies
    27  // errors that result from receiving a UDP packet larger
    28  // than the supplied receive buffer.
    29  func TestIsPacketTooBig(t *testing.T) {
    30  	listener, err := net.ListenPacket("udp", "127.0.0.1:0")
    31  	if err != nil {
    32  		t.Fatal(err)
    33  	}
    34  	defer listener.Close()
    35  	sender, err := net.Dial("udp", listener.LocalAddr().String())
    36  	if err != nil {
    37  		t.Fatal(err)
    38  	}
    39  	defer sender.Close()
    40  
    41  	sendN := 1800
    42  	recvN := 300
    43  	for i := 0; i < 20; i++ {
    44  		go func() {
    45  			buf := make([]byte, sendN)
    46  			for i := range buf {
    47  				buf[i] = byte(i)
    48  			}
    49  			sender.Write(buf)
    50  		}()
    51  
    52  		buf := make([]byte, recvN)
    53  		listener.SetDeadline(time.Now().Add(1 * time.Second))
    54  		n, _, err := listener.ReadFrom(buf)
    55  		if err != nil {
    56  			if nerr, ok := err.(net.Error); ok && nerr.Timeout() {
    57  				continue
    58  			}
    59  			if !isPacketTooBig(err) {
    60  				t.Fatalf("unexpected read error: %v", err)
    61  			}
    62  			continue
    63  		}
    64  		if n != recvN {
    65  			t.Fatalf("short read: %d, want %d", n, recvN)
    66  		}
    67  		for i := range buf {
    68  			if buf[i] != byte(i) {
    69  				t.Fatalf("error in pattern")
    70  				break
    71  			}
    72  		}
    73  	}
    74  }