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Added more docs

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This commit is contained in:
Dmitri Dolguikh 2017-11-03 15:37:07 -07:00 committed by Dave Anderson
parent 13846a9809
commit fb66f2fcb8
3 changed files with 35 additions and 28 deletions
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31
dhcp6/options.go
View File

@ -72,6 +72,7 @@ func MakeOption(id uint16, value []byte) *Option {
// Options contains all options of a DHCPv6 packet // Options contains all options of a DHCPv6 packet
type Options map[uint16][]*Option type Options map[uint16][]*Option
// MakeOptions unmarshals individual Options and returns them in a new Options data structure
func MakeOptions(bs []byte) (Options, error) { func MakeOptions(bs []byte) (Options, error) {
ret := make(Options) ret := make(Options)
for len(bs) > 0 { for len(bs) > 0 {
@ -88,8 +89,8 @@ func MakeOptions(bs []byte) (Options, error) {
// UnmarshalOption de-serializes an Option // UnmarshalOption de-serializes an Option
func UnmarshalOption(bs []byte) (*Option, error) { func UnmarshalOption(bs []byte) (*Option, error) {
optionLength := uint16(binary.BigEndian.Uint16(bs[2:4])) optionLength := uint16(binary.BigEndian.Uint16(bs[2:4]))
optionId := uint16(binary.BigEndian.Uint16(bs[0:2])) optionID := uint16(binary.BigEndian.Uint16(bs[0:2]))
switch optionId { switch optionID {
// parse client_id // parse client_id
// parse server_id // parse server_id
//parse ipaddr //parse ipaddr
@ -99,36 +100,36 @@ func UnmarshalOption(bs []byte) (*Option, error) {
} }
default: default:
if len(bs[4:]) < int(optionLength) { if len(bs[4:]) < int(optionLength) {
fmt.Printf("option %d claims to have %d bytes of payload, but only has %d bytes", optionId, optionLength, len(bs[4:])) fmt.Printf("option %d claims to have %d bytes of payload, but only has %d bytes", optionID, optionLength, len(bs[4:]))
return nil, fmt.Errorf("option %d claims to have %d bytes of payload, but only has %d bytes", optionId, optionLength, len(bs[4:])) return nil, fmt.Errorf("option %d claims to have %d bytes of payload, but only has %d bytes", optionID, optionLength, len(bs[4:]))
} }
} }
return &Option{ ID: optionId, Length: optionLength, Value: bs[4 : 4+optionLength]}, nil return &Option{ ID: optionID, Length: optionLength, Value: bs[4 : 4+optionLength]}, nil
} }
// HumanReadable presents DHCPv6 options in a human-readable form // HumanReadable presents DHCPv6 options in a human-readable form
func (o Options) HumanReadable() []string { func (o Options) HumanReadable() []string {
to_ret := make([]string, 0, len(o)) ret := make([]string, 0, len(o))
for _, multipleOptions := range(o) { for _, multipleOptions := range(o) {
for _, option := range(multipleOptions) { for _, option := range(multipleOptions) {
switch option.ID { switch option.ID {
case 3: case 3:
to_ret = append(to_ret, o.humanReadableIaNa(*option)...) ret = append(ret, o.humanReadableIaNa(*option)...)
default: default:
to_ret = append(to_ret, fmt.Sprintf("Option: %d | %d | %d | %s\n", option.ID, option.Length, option.Value, option.Value)) ret = append(ret, fmt.Sprintf("Option: %d | %d | %d | %s\n", option.ID, option.Length, option.Value, option.Value))
} }
} }
} }
return to_ret return ret
} }
func (o Options) humanReadableIaNa(opt Option) []string { func (o Options) humanReadableIaNa(opt Option) []string {
to_ret := make([]string, 0) ret := make([]string, 0)
to_ret = append(to_ret, fmt.Sprintf("Option: OptIaNa | len %d | iaid %x | t1 %d | t2 %d\n", ret = append(ret, fmt.Sprintf("Option: OptIaNa | len %d | iaid %x | t1 %d | t2 %d\n",
opt.Length, opt.Value[0:4], binary.BigEndian.Uint32(opt.Value[4:8]), binary.BigEndian.Uint32(opt.Value[8:12]))) opt.Length, opt.Value[0:4], binary.BigEndian.Uint32(opt.Value[4:8]), binary.BigEndian.Uint32(opt.Value[8:12])))
if opt.Length <= 12 { if opt.Length <= 12 {
return to_ret // no options return ret // no options
} }
iaOptions := opt.Value[12:] iaOptions := opt.Value[12:]
@ -141,17 +142,17 @@ func (o Options) humanReadableIaNa(opt Option) []string {
case OptIaAddr: case OptIaAddr:
ip := make(net.IP, 16) ip := make(net.IP, 16)
copy(ip, iaOptions[4:20]) copy(ip, iaOptions[4:20])
to_ret = append(to_ret, fmt.Sprintf("\tOption: IA_ADDR | len %d | ip %s | preferred %d | valid %d | %v \n", ret = append(ret, fmt.Sprintf("\tOption: IA_ADDR | len %d | ip %s | preferred %d | valid %d | %v \n",
l, ip, binary.BigEndian.Uint32(iaOptions[20:24]), binary.BigEndian.Uint32(iaOptions[24:28]), iaOptions[28:4+l])) l, ip, binary.BigEndian.Uint32(iaOptions[20:24]), binary.BigEndian.Uint32(iaOptions[24:28]), iaOptions[28:4+l]))
default: default:
to_ret = append(to_ret, fmt.Sprintf("\tOption: id %d | len %d | %s\n", ret = append(ret, fmt.Sprintf("\tOption: id %d | len %d | %s\n",
id, l, iaOptions[4:4+l])) id, l, iaOptions[4:4+l]))
} }
iaOptions = iaOptions[4+l:] iaOptions = iaOptions[4+l:]
} }
return to_ret return ret
} }
// AddOption adds an option to Options // AddOption adds an option to Options

18
dhcp6/packet.go
View File

@ -5,8 +5,10 @@ import (
"bytes" "bytes"
) )
// MessageType contains ID identifying DHCP message type. See RFC 3315
type MessageType uint8 type MessageType uint8
// Constants for each of the dhcp message types defined in RFC 3315
const ( const (
MsgSolicit MessageType = iota + 1 MsgSolicit MessageType = iota + 1
MsgAdvertise MsgAdvertise
@ -23,12 +25,14 @@ const (
MsgRelayRepl MsgRelayRepl
) )
// Packet represents a DHCPv6 packet
type Packet struct { type Packet struct {
Type MessageType Type MessageType
TransactionID [3]byte TransactionID [3]byte
Options Options Options Options
} }
// MakePacket creates a Packet out of its serialized representation
func MakePacket(bs []byte, packetLength int) (*Packet, error) { func MakePacket(bs []byte, packetLength int) (*Packet, error) {
options, err := MakeOptions(bs[4:packetLength]) options, err := MakeOptions(bs[4:packetLength])
if err != nil { if err != nil {
@ -39,6 +43,7 @@ func MakePacket(bs []byte, packetLength int) (*Packet, error) {
return ret, nil return ret, nil
} }
// Marshal serializes the Packet
func (p *Packet) Marshal() ([]byte, error) { func (p *Packet) Marshal() ([]byte, error) {
marshalledOptions, err := p.Options.Marshal() marshalledOptions, err := p.Options.Marshal()
if err != nil { if err != nil {
@ -53,14 +58,15 @@ func (p *Packet) Marshal() ([]byte, error) {
return ret, nil return ret, nil
} }
// ShouldDiscard returns true if the Packet fails validation
func (p *Packet) ShouldDiscard(serverDuid []byte) error { func (p *Packet) ShouldDiscard(serverDuid []byte) error {
switch p.Type { switch p.Type {
case MsgSolicit: case MsgSolicit:
return ShouldDiscardSolicit(p) return shouldDiscardSolicit(p)
case MsgRequest: case MsgRequest:
return ShouldDiscardRequest(p, serverDuid) return shouldDiscardRequest(p, serverDuid)
case MsgInformationRequest: case MsgInformationRequest:
return ShouldDiscardInformationRequest(p, serverDuid) return shouldDiscardInformationRequest(p, serverDuid)
case MsgRelease: case MsgRelease:
return nil // FIX ME! return nil // FIX ME!
default: default:
@ -68,7 +74,7 @@ func (p *Packet) ShouldDiscard(serverDuid []byte) error {
} }
} }
func ShouldDiscardSolicit(p *Packet) error { func shouldDiscardSolicit(p *Packet) error {
options := p.Options options := p.Options
if !options.HasBootFileURLOption() { if !options.HasBootFileURLOption() {
return fmt.Errorf("'Solicit' packet doesn't have file url option") return fmt.Errorf("'Solicit' packet doesn't have file url option")
@ -82,7 +88,7 @@ func ShouldDiscardSolicit(p *Packet) error {
return nil return nil
} }
func ShouldDiscardRequest(p *Packet, serverDuid []byte) error { func shouldDiscardRequest(p *Packet, serverDuid []byte) error {
options := p.Options options := p.Options
if !options.HasBootFileURLOption() { if !options.HasBootFileURLOption() {
return fmt.Errorf("'Request' packet doesn't have file url option") return fmt.Errorf("'Request' packet doesn't have file url option")
@ -99,7 +105,7 @@ func ShouldDiscardRequest(p *Packet, serverDuid []byte) error {
return nil return nil
} }
func ShouldDiscardInformationRequest(p *Packet, serverDuid []byte) error { func shouldDiscardInformationRequest(p *Packet, serverDuid []byte) error {
options := p.Options options := p.Options
if !options.HasBootFileURLOption() { if !options.HasBootFileURLOption() {
return fmt.Errorf("'Information-request' packet doesn't have boot file url option") return fmt.Errorf("'Information-request' packet doesn't have boot file url option")

14
dhcp6/packet_test.go
View File

@ -11,7 +11,7 @@ func TestShouldDiscardSolicitWithoutBootfileUrlOption(t *testing.T) {
options.AddOption(&Option{ID: OptClientID, Length: uint16(len(clientID)), Value: clientID}) options.AddOption(&Option{ID: OptClientID, Length: uint16(len(clientID)), Value: clientID})
solicit := &Packet{Type: MsgSolicit, TransactionID: [3]byte{'1', '2', '3'}, Options: options} solicit := &Packet{Type: MsgSolicit, TransactionID: [3]byte{'1', '2', '3'}, Options: options}
if err := ShouldDiscardSolicit(solicit); err == nil { if err := shouldDiscardSolicit(solicit); err == nil {
t.Fatalf("Should discard solicit packet without bootfile url option, but didn't") t.Fatalf("Should discard solicit packet without bootfile url option, but didn't")
} }
} }
@ -21,7 +21,7 @@ func TestShouldDiscardSolicitWithoutClientIdOption(t *testing.T) {
options.AddOption(MakeOptionRequestOptions([]uint16{OptBootfileURL})) options.AddOption(MakeOptionRequestOptions([]uint16{OptBootfileURL}))
solicit := &Packet{Type: MsgSolicit, TransactionID: [3]byte{'1', '2', '3'}, Options: options} solicit := &Packet{Type: MsgSolicit, TransactionID: [3]byte{'1', '2', '3'}, Options: options}
if err := ShouldDiscardSolicit(solicit); err == nil { if err := shouldDiscardSolicit(solicit); err == nil {
t.Fatalf("Should discard solicit packet without client id option, but didn't") t.Fatalf("Should discard solicit packet without client id option, but didn't")
} }
} }
@ -35,7 +35,7 @@ func TestShouldDiscardSolicitWithServerIdOption(t *testing.T) {
options.AddOption(&Option{ID: OptServerID, Length: uint16(len(serverID)), Value: serverID}) options.AddOption(&Option{ID: OptServerID, Length: uint16(len(serverID)), Value: serverID})
solicit := &Packet{Type: MsgSolicit, TransactionID: [3]byte{'1', '2', '3'}, Options: options} solicit := &Packet{Type: MsgSolicit, TransactionID: [3]byte{'1', '2', '3'}, Options: options}
if err := ShouldDiscardSolicit(solicit); err == nil { if err := shouldDiscardSolicit(solicit); err == nil {
t.Fatalf("Should discard solicit packet with server id option, but didn't") t.Fatalf("Should discard solicit packet with server id option, but didn't")
} }
} }
@ -48,7 +48,7 @@ func TestShouldDiscardRequestWithoutBootfileUrlOption(t *testing.T) {
options.AddOption(&Option{ID: OptServerID, Length: uint16(len(serverID)), Value: serverID}) options.AddOption(&Option{ID: OptServerID, Length: uint16(len(serverID)), Value: serverID})
request := &Packet{Type: MsgRequest, TransactionID: [3]byte{'1', '2', '3'}, Options: options} request := &Packet{Type: MsgRequest, TransactionID: [3]byte{'1', '2', '3'}, Options: options}
if err := ShouldDiscardRequest(request, serverID); err == nil { if err := shouldDiscardRequest(request, serverID); err == nil {
t.Fatalf("Should discard request packet without bootfile url option, but didn't") t.Fatalf("Should discard request packet without bootfile url option, but didn't")
} }
} }
@ -60,7 +60,7 @@ func TestShouldDiscardRequestWithoutClientIdOption(t *testing.T) {
options.AddOption(&Option{ID: OptServerID, Length: uint16(len(serverID)), Value: serverID}) options.AddOption(&Option{ID: OptServerID, Length: uint16(len(serverID)), Value: serverID})
request := &Packet{Type: MsgRequest, TransactionID: [3]byte{'1', '2', '3'}, Options: options} request := &Packet{Type: MsgRequest, TransactionID: [3]byte{'1', '2', '3'}, Options: options}
if err := ShouldDiscardRequest(request, serverID); err == nil { if err := shouldDiscardRequest(request, serverID); err == nil {
t.Fatalf("Should discard request packet without client id option, but didn't") t.Fatalf("Should discard request packet without client id option, but didn't")
} }
} }
@ -72,7 +72,7 @@ func TestShouldDiscardRequestWithoutServerIdOption(t *testing.T) {
options.AddOption(&Option{ID: OptClientID, Length: uint16(len(clientID)), Value: clientID}) options.AddOption(&Option{ID: OptClientID, Length: uint16(len(clientID)), Value: clientID})
request := &Packet{Type: MsgRequest, TransactionID: [3]byte{'1', '2', '3'}, Options: options} request := &Packet{Type: MsgRequest, TransactionID: [3]byte{'1', '2', '3'}, Options: options}
if err := ShouldDiscardRequest(request, []byte("serverid")); err == nil { if err := shouldDiscardRequest(request, []byte("serverid")); err == nil {
t.Fatalf("Should discard request packet with server id option, but didn't") t.Fatalf("Should discard request packet with server id option, but didn't")
} }
} }
@ -86,7 +86,7 @@ func TestShouldDiscardRequestWithWrongServerId(t *testing.T) {
options.AddOption(&Option{ID: OptServerID, Length: uint16(len(serverID)), Value: serverID}) options.AddOption(&Option{ID: OptServerID, Length: uint16(len(serverID)), Value: serverID})
request := &Packet{Type: MsgRequest, TransactionID: [3]byte{'1', '2', '3'}, Options: options} request := &Packet{Type: MsgRequest, TransactionID: [3]byte{'1', '2', '3'}, Options: options}
if err := ShouldDiscardRequest(request, []byte("wrongid")); err == nil { if err := shouldDiscardRequest(request, []byte("wrongid")); err == nil {
t.Fatalf("Should discard request packet with wrong server id option, but didn't") t.Fatalf("Should discard request packet with wrong server id option, but didn't")
} }
} }