/
server_test.go
270 lines (233 loc) · 6.19 KB
/
server_test.go
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package main
import (
"errors"
"fmt"
"github.com/cewillis001/tftp"
"net"
"strconv"
"testing"
"time"
)
//a six hundred char "Lorem ipsum" string
var longFile string = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu. In enim justo, rhoncus ut, imperdiet a, venenatis vitae, justo. Nullam dictum felis eu pede mollis pretium. Integer tincidunt. Cras dapibus. Vivamus elementum semper nisi. Aenean vulputate eleifend tellus. Aenean leo ligula, porttitor eu,"
//int controlling how many go routines to spawn for concurrency test
//set low initially so a verbose test of the server is still manageable to read
var lots int = 500
func checkError(err error) {
if err != nil {
fmt.Println("Error: ", err)
}
}
func min(a int, b int) int {
if a <= b {
return a
}
return b
}
func sendFullWrite(filename string, content string) {
//sends inital WRQ
//waits for ack block 0,0 or times out
//loop
// sends data
// waits for ack, or handles error, or resends
// if data sent and acknowledged was last data, end
ServerAddr, err := net.ResolveUDPAddr("udp", "127.0.0.1:10001")
checkError(err)
LocalAddr, err := net.ResolveUDPAddr("udp", "127.0.0.1:0")
checkError(err)
Conn, err := net.DialUDP("udp", LocalAddr, ServerAddr)
checkError(err)
defer Conn.Close()
/* initialize variables for tracking acknowledgements and location in content*/
index := 0
f := []byte(content)
max := min(512, len(f))
data := f[index:max]
block := []byte{0, 0}
/*send inital WRQ*/
/*send inital WRQ*/
tftp.SendWRQ(filename, Conn)
packet := make(chan []byte)
defer close(packet)
go getPacket(Conn, packet)
select {
case <-time.After(15 * time.Second):
fmt.Println("WRQ from ", LocalAddr, " never acknowledged")
return
case r := <-packet:
switch r[1] {
case 4:
//ACK packet recieved
ackBlock, err := tftp.GetAckBlock(r)
if err != nil {
errCode := []byte{0, 0}
errMsg := "badly formed ACK packet"
tftp.SendERROR(errCode, errMsg, Conn)
return
}
if ackBlock[1] == block[1] {
break
}
case 5:
//ERROR packet recieved
_, errMsg, err := tftp.GetError(r)
if err != nil {
return
}
fmt.Println(string(errMsg), " recieved by ", LocalAddr)
return
}
}
SendLoop:
for {
//send Data
block[1]++
tftp.SendDATA(block, data, Conn)
//wait for ack
LoopAck:
for {
select {
case <-time.After(time.Second * 3):
tftp.SendDATA(block, data, Conn)
case <-time.After(time.Second * 15):
fmt.Println("DATA packet ", string(block), " from ", LocalAddr, " never acknowledged")
return
case r := <-packet:
switch r[1] {
case 4:
//ACK packet recieved
ackBlock, err := tftp.GetAckBlock(r)
if err != nil {
errCode := []byte{0, 0}
errMsg := "badly formed ACK packet"
tftp.SendERROR(errCode, errMsg, Conn)
return
}
if ackBlock[1] == block[1] {
break LoopAck
}
case 5:
//ERROR packet recieved
_, errMsg, err := tftp.GetError(r)
if err != nil {
return
}
fmt.Println(string(errMsg), " recieved by ", LocalAddr)
return
}
}
}
if max == len(content) {
break SendLoop
}
//update data
index += 512
max = min(index+512, len(f))
data = f[index:max]
}
}
func getPacket(Conn *net.UDPConn, out chan<- []byte) {
for {
buf := make([]byte, 1024)
n, _, err := Conn.ReadFromUDP(buf)
if err == nil {
out <- buf[0:n]
} else {
return
}
}
}
func sendFullRead(filename string) (string, error) {
//sends RRQ
//loop:
// listens for DATA with block ahead of prev ACK packet
// send ACK packet for current DATA
// if len(current DATA) < 512, send final ACK and close
ServerAddr, err := net.ResolveUDPAddr("udp", "127.0.0.1:10001")
checkError(err)
LocalAddr, err := net.ResolveUDPAddr("udp", "127.0.0.1:0")
checkError(err)
Conn, err := net.DialUDP("udp", LocalAddr, ServerAddr)
checkError(err)
defer Conn.Close()
temp := []byte{}
tftp.SendRRQ(filename, Conn)
prev_block := []byte{0, 0}
packet := make(chan []byte)
defer close(packet)
go getPacket(Conn, packet)
Read:
for {
select {
case r := <-packet:
switch r[1] {
case 3:
//DATA packet recieved
block, data, err := tftp.GetData(r)
if err != nil {
return "", err
}
if block[1] == prev_block[1]+1 {
tftp.SendACK(block, Conn)
prev_block[1] = block[1]
temp = append(temp, data...)
if len(data) < 512 {
break Read
}
} else if block[1] != 0 {
tftp.SendACK(prev_block, Conn)
} // else the RRQ itself failed somehow
case 5:
//ERROR packet recieved
_, errMsg, err := tftp.GetError(r)
if err != nil {
return "", err
}
fmt.Println(string(errMsg), " recieved by ", LocalAddr)
return "", errors.New(string(errMsg))
}
case <-time.After(1 * time.Second):
tftp.SendACK(prev_block, Conn)
case <-time.After(15 * time.Second):
fmt.Println("A read request by ", LocalAddr, " timed out")
return "", errors.New("rrq timed out")
}
}
return string(temp), nil
}
/* BEGIN TESTS */
func TestOneWRQ(*testing.T) {
sendFullWrite("TestOneWRQ", "TestOneWRQ "+longFile)
} // */
func TestManyWRQ(*testing.T) {
for i := 0; i < lots; i++ {
go sendFullWrite("TestManyWRQ"+strconv.Itoa(i), "Hello, World "+strconv.Itoa(i)+"! "+longFile)
}
} // */
func TestOneRRQ(t *testing.T) {
temp := "Test a read! " + longFile
sendFullWrite("TestOneRRQ", temp)
read, err := sendFullRead("TestOneRRQ")
if err != nil {
return
}
if len(temp) != len(read) {
t.FailNow()
} else {
for i := 0; i < len(temp); i++ {
if temp[i] != read[i] {
t.FailNow()
}
}
}
} // */
func TestManyRRQ(*testing.T) {
sendFullWrite("TestManyRRQ", "Testing many reads! "+longFile)
for i := 0; i < lots; i++ {
go sendFullRead("TestManyRRQ")
}
} // */
func TestOneOverWrite(*testing.T) {
sendFullWrite("TestOneOverWrite", "TestOneOverWrite "+longFile)
sendFullWrite("TestOneOverWrite", "TestOneOverWrite, overwritten "+longFile)
} // */