From: Jeff Halter Date: Thu, 30 Jun 2022 00:08:10 +0000 (-0700) Subject: Refactor and backfill tests for tracker listing X-Git-Url: https://git.r.bdr.sh/rbdr/mobius/commitdiff_plain/8ff2b66d1583b38298dfa415588df89631023695?ds=inline;hp=-c Refactor and backfill tests for tracker listing --- 8ff2b66d1583b38298dfa415588df89631023695 diff --git a/hotline/file_header_test.go b/hotline/file_header_test.go index 0194a60..99fe4e4 100644 --- a/hotline/file_header_test.go +++ b/hotline/file_header_test.go @@ -85,7 +85,7 @@ func TestFileHeader_Payload(t *testing.T) { FilePath: tt.fields.FilePath, } if got := fh.Payload(); !reflect.DeepEqual(got, tt.want) { - t.Errorf("Payload() = %v, want %v", got, tt.want) + t.Errorf("Read() = %v, want %v", got, tt.want) } }) } diff --git a/hotline/tracker.go b/hotline/tracker.go index 63fb279..4d4c8a6 100644 --- a/hotline/tracker.go +++ b/hotline/tracker.go @@ -1,9 +1,8 @@ package hotline import ( - "bytes" + "bufio" "encoding/binary" - "errors" "fmt" "github.com/jhalter/mobius/concat" "net" @@ -11,6 +10,7 @@ import ( "time" ) +// TrackerRegistration represents the payload a Hotline server sends to a Tracker to register type TrackerRegistration struct { Port [2]byte // Server listening port number UserCount int // Number of users connected to this particular server @@ -19,7 +19,8 @@ type TrackerRegistration struct { Description string // Description of the server } -func (tr *TrackerRegistration) Payload() []byte { +// TODO: reimplement as io.Reader +func (tr *TrackerRegistration) Read() []byte { userCount := make([]byte, 2) binary.BigEndian.PutUint16(userCount, uint16(tr.UserCount)) @@ -42,7 +43,9 @@ func register(tracker string, tr *TrackerRegistration) error { return err } - if _, err := conn.Write(tr.Payload()); err != nil { + b := tr.Read() + + if _, err := conn.Write(b); err != nil { return err } @@ -103,64 +106,61 @@ func GetListing(addr string) ([]ServerRecord, error) { return nil, err } - totalRead := 0 - - buf := make([]byte, 4096) - var readLen int - if readLen, err = conn.Read(buf); err != nil { - return nil, err - } - totalRead += readLen // 1514 - var th TrackerHeader - if err := binary.Read(bytes.NewReader(buf[:6]), binary.BigEndian, &th); err != nil { + if err := binary.Read(conn, binary.BigEndian, &th); err != nil { return nil, err } var info ServerInfoHeader - if err := binary.Read(bytes.NewReader(buf[6:14]), binary.BigEndian, &info); err != nil { + if err := binary.Read(conn, binary.BigEndian, &info); err != nil { return nil, err } - payloadSize := int(binary.BigEndian.Uint16(info.MsgDataSize[:])) - - buf = buf[:readLen] - if totalRead < payloadSize { - for { - tmpBuf := make([]byte, 4096) - if readLen, err = conn.Read(tmpBuf); err != nil { - return nil, err - } - buf = append(buf, tmpBuf[:readLen]...) - totalRead += readLen - if totalRead >= payloadSize { - break - } - } - } totalSrv := int(binary.BigEndian.Uint16(info.SrvCount[:])) - srvBuf := buf[14:totalRead] + scanner := bufio.NewScanner(conn) + scanner.Split(serverScanner) var servers []ServerRecord - for { + scanner.Scan() var srv ServerRecord - n, _ := srv.Read(srvBuf) - servers = append(servers, srv) - - srvBuf = srvBuf[n:] + _, _ = srv.Read(scanner.Bytes()) + servers = append(servers, srv) if len(servers) == totalSrv { - return servers, nil + break } + } - if len(srvBuf) == 0 { - return servers, errors.New("tracker sent too few bytes for server count") - } + return servers, nil +} + +// serverScanner implements bufio.SplitFunc for parsing the tracker list into ServerRecords tokens +// Example payload: +// 00000000 18 05 30 63 15 7c 00 02 00 00 10 54 68 65 20 4d |..0c.|.....The M| +// 00000010 6f 62 69 75 73 20 53 74 72 69 70 40 48 6f 6d 65 |obius Strip@Home| +// 00000020 20 6f 66 20 74 68 65 20 4d 6f 62 69 75 73 20 48 | of the Mobius H| +// 00000030 6f 74 6c 69 6e 65 20 73 65 72 76 65 72 20 61 6e |otline server an| +// 00000040 64 20 63 6c 69 65 6e 74 20 7c 20 54 52 54 50 48 |d client | TRTPH| +// 00000050 4f 54 4c 2e 63 6f 6d 3a 35 35 30 30 2d 4f 3a b2 |OTL.com:5500-O:.| +// 00000060 15 7c 00 00 00 00 08 53 65 6e 65 63 74 75 73 20 |.|.....Senectus | +func serverScanner(data []byte, _ bool) (advance int, token []byte, err error) { + if len(data) < 10 { + return 0, nil, nil } + + // A server entry has two variable length fields: the name and description. + // To get the token length, we first need the name length from the 10th byte: + nameLen := int(data[10]) + + // Next we need the description length from the 11+nameLen byte: + descLen := int(data[11+nameLen]) + + return 12 + nameLen + descLen, data[0 : 12+nameLen+descLen], nil } +// Read implements io.Reader for ServerRecord func (s *ServerRecord) Read(b []byte) (n int, err error) { copy(s.IPAddr[:], b[0:4]) copy(s.Port[:], b[4:6]) @@ -174,11 +174,6 @@ func (s *ServerRecord) Read(b []byte) (n int, err error) { return 12 + nameLen + int(s.DescriptionSize), nil } -func (s *ServerRecord) PortInt() int { - data := binary.BigEndian.Uint16(s.Port[:]) - return int(data) -} - func (s *ServerRecord) Addr() string { return fmt.Sprintf("%s:%s", net.IP(s.IPAddr[:]), diff --git a/hotline/tracker_test.go b/hotline/tracker_test.go index 72d84ba..3e0be5d 100644 --- a/hotline/tracker_test.go +++ b/hotline/tracker_test.go @@ -1,6 +1,8 @@ package hotline import ( + "fmt" + "github.com/stretchr/testify/assert" "reflect" "testing" ) @@ -49,9 +51,103 @@ func TestTrackerRegistration_Payload(t *testing.T) { Name: tt.fields.Name, Description: tt.fields.Description, } - if got := tr.Payload(); !reflect.DeepEqual(got, tt.want) { - t.Errorf("Payload() = %v, want %v", got, tt.want) + if got := tr.Read(); !reflect.DeepEqual(got, tt.want) { + t.Errorf("Read() = %v, want %v", got, tt.want) } }) } } + +func Test_serverScanner(t *testing.T) { + type args struct { + data []byte + atEOF bool + } + tests := []struct { + name string + args args + wantAdvance int + wantToken []byte + wantErr assert.ErrorAssertionFunc + }{ + { + name: "when a full server entry is provided", + args: args{ + data: []byte{ + 0x18, 0x05, 0x30, 0x63, // IP Addr + 0x15, 0x7c, // Port + 0x00, 0x02, // UserCount + 0x00, 0x00, // ?? + 0x03, // Name Len + 0x54, 0x68, 0x65, // Name + 0x03, // Desc Len + 0x54, 0x54, 0x54, // Description + }, + atEOF: false, + }, + wantAdvance: 18, + wantToken: []byte{ + 0x18, 0x05, 0x30, 0x63, // IP Addr + 0x15, 0x7c, // Port + 0x00, 0x02, // UserCount + 0x00, 0x00, // ?? + 0x03, // Name Len + 0x54, 0x68, 0x65, // Name + 0x03, // Desc Len + 0x54, 0x54, 0x54, // Description + }, + wantErr: assert.NoError, + }, + { + name: "when extra bytes are provided", + args: args{ + data: []byte{ + 0x18, 0x05, 0x30, 0x63, // IP Addr + 0x15, 0x7c, // Port + 0x00, 0x02, // UserCount + 0x00, 0x00, // ?? + 0x03, // Name Len + 0x54, 0x68, 0x65, // Name + 0x03, // Desc Len + 0x54, 0x54, 0x54, // Description + 0x54, 0x54, 0x54, 0x54, 0x54, 0x54, 0x54, 0x54, 0x54, + }, + atEOF: false, + }, + wantAdvance: 18, + wantToken: []byte{ + 0x18, 0x05, 0x30, 0x63, // IP Addr + 0x15, 0x7c, // Port + 0x00, 0x02, // UserCount + 0x00, 0x00, // ?? + 0x03, // Name Len + 0x54, 0x68, 0x65, // Name + 0x03, // Desc Len + 0x54, 0x54, 0x54, // Description + }, + wantErr: assert.NoError, + }, + { + name: "when insufficient bytes are provided", + args: args{ + data: []byte{ + 0, 0, + }, + atEOF: false, + }, + wantAdvance: 0, + wantToken: []byte(nil), + wantErr: assert.NoError, + }, + } + for _, tt := range tests { + t.Run(tt.name, func(t *testing.T) { + gotAdvance, gotToken, err := serverScanner(tt.args.data, tt.args.atEOF) + if !tt.wantErr(t, err, fmt.Sprintf("serverScanner(%v, %v)", tt.args.data, tt.args.atEOF)) { + return + } + assert.Equalf(t, tt.wantAdvance, gotAdvance, "serverScanner(%v, %v)", tt.args.data, tt.args.atEOF) + assert.Equalf(t, tt.wantToken, gotToken, "serverScanner(%v, %v)", tt.args.data, tt.args.atEOF) + }) + } +}