| // Copyright 2009 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| |
| // TODO(cw): ListenPacket test, Read() test, ipv6 test & |
| // Dial()/Listen() level tests |
| |
| package net |
| |
| import ( |
| "bytes" |
| "flag" |
| "os" |
| "testing" |
| ) |
| |
| const ICMP_ECHO_REQUEST = 8 |
| const ICMP_ECHO_REPLY = 0 |
| |
| // returns a suitable 'ping request' packet, with id & seq and a |
| // payload length of pktlen |
| func makePingRequest(id, seq, pktlen int, filler []byte) []byte { |
| p := make([]byte, pktlen) |
| copy(p[8:], bytes.Repeat(filler, (pktlen-8)/len(filler)+1)) |
| |
| p[0] = ICMP_ECHO_REQUEST // type |
| p[1] = 0 // code |
| p[2] = 0 // cksum |
| p[3] = 0 // cksum |
| p[4] = uint8(id >> 8) // id |
| p[5] = uint8(id & 0xff) // id |
| p[6] = uint8(seq >> 8) // sequence |
| p[7] = uint8(seq & 0xff) // sequence |
| |
| // calculate icmp checksum |
| cklen := len(p) |
| s := uint32(0) |
| for i := 0; i < (cklen - 1); i += 2 { |
| s += uint32(p[i+1])<<8 | uint32(p[i]) |
| } |
| if cklen&1 == 1 { |
| s += uint32(p[cklen-1]) |
| } |
| s = (s >> 16) + (s & 0xffff) |
| s = s + (s >> 16) |
| |
| // place checksum back in header; using ^= avoids the |
| // assumption the checksum bytes are zero |
| p[2] ^= uint8(^s & 0xff) |
| p[3] ^= uint8(^s >> 8) |
| |
| return p |
| } |
| |
| func parsePingReply(p []byte) (id, seq int) { |
| id = int(p[4])<<8 | int(p[5]) |
| seq = int(p[6])<<8 | int(p[7]) |
| return |
| } |
| |
| var srchost = flag.String("srchost", "", "Source of the ICMP ECHO request") |
| var dsthost = flag.String("dsthost", "localhost", "Destination for the ICMP ECHO request") |
| |
| // test (raw) IP socket using ICMP |
| func TestICMP(t *testing.T) { |
| if os.Getuid() != 0 { |
| t.Logf("test disabled; must be root") |
| return |
| } |
| |
| var laddr *IPAddr |
| if *srchost != "" { |
| laddr, err := ResolveIPAddr(*srchost) |
| if err != nil { |
| t.Fatalf(`net.ResolveIPAddr("%v") = %v, %v`, *srchost, laddr, err) |
| } |
| } |
| |
| raddr, err := ResolveIPAddr(*dsthost) |
| if err != nil { |
| t.Fatalf(`net.ResolveIPAddr("%v") = %v, %v`, *dsthost, raddr, err) |
| } |
| |
| c, err := ListenIP("ip4:icmp", laddr) |
| if err != nil { |
| t.Fatalf(`net.ListenIP("ip4:icmp", %v) = %v, %v`, *srchost, c, err) |
| } |
| |
| sendid := os.Getpid() & 0xffff |
| const sendseq = 61455 |
| const pingpktlen = 128 |
| sendpkt := makePingRequest(sendid, sendseq, pingpktlen, []byte("Go Go Gadget Ping!!!")) |
| |
| n, err := c.WriteToIP(sendpkt, raddr) |
| if err != nil || n != pingpktlen { |
| t.Fatalf(`net.WriteToIP(..., %v) = %v, %v`, raddr, n, err) |
| } |
| |
| c.SetTimeout(100e6) |
| resp := make([]byte, 1024) |
| for { |
| n, from, err := c.ReadFrom(resp) |
| if err != nil { |
| t.Fatalf(`ReadFrom(...) = %v, %v, %v`, n, from, err) |
| } |
| if resp[0] != ICMP_ECHO_REPLY { |
| continue |
| } |
| rcvid, rcvseq := parsePingReply(resp) |
| if rcvid != sendid || rcvseq != sendseq { |
| t.Fatalf(`Ping reply saw id,seq=0x%x,0x%x (expected 0x%x, 0x%x)`, rcvid, rcvseq, sendid, sendseq) |
| } |
| return |
| } |
| t.Fatalf("saw no ping return") |
| } |