diff options
| -rw-r--r-- | dhcpv4/bsdp/boot_image_test.go | 20 | ||||
| -rw-r--r-- | dhcpv4/bsdp/bsdp.go | 88 | ||||
| -rw-r--r-- | dhcpv4/bsdp/option_vendor_specific_information.go | 138 | ||||
| -rw-r--r-- | dhcpv4/bsdp/types.go | 26 |
4 files changed, 176 insertions, 96 deletions
diff --git a/dhcpv4/bsdp/boot_image_test.go b/dhcpv4/bsdp/boot_image_test.go index ebf02c3..86a2e9f 100644 --- a/dhcpv4/bsdp/boot_image_test.go +++ b/dhcpv4/bsdp/boot_image_test.go @@ -8,9 +8,6 @@ import ( "github.com/stretchr/testify/require" ) -/* - * BootImageID - */ func TestBootImageIDToBytes(t *testing.T) { b := BootImageID{ IsInstall: true, @@ -54,6 +51,11 @@ func TestBootImageIDFromBytesFail(t *testing.T) { require.Error(t, err) } +func TestBootImageIDString(t *testing.T) { + b := BootImageID{IsInstall: false, ImageType: BootImageTypeMacOSX, Index: 1001} + require.Equal(t, "[1001] uninstallable macOS image", b.String()) +} + /* * BootImage */ @@ -128,3 +130,15 @@ func TestBootImageFromBytesShortBootImage(t *testing.T) { require.Nil(t, b) require.Error(t, err) } + +func TestBootImageString(t *testing.T) { + b := BootImage{ + ID: BootImageID{ + IsInstall: false, + ImageType: BootImageTypeMacOSX, + Index: 0x1010, + }, + Name: "bsdp-21", + } + require.Equal(t, "bsdp-21 [4112] uninstallable macOS image", b.String()) +} diff --git a/dhcpv4/bsdp/bsdp.go b/dhcpv4/bsdp/bsdp.go index 1c2b100..f04e255 100644 --- a/dhcpv4/bsdp/bsdp.go +++ b/dhcpv4/bsdp/bsdp.go @@ -9,7 +9,6 @@ package bsdp import ( "errors" "fmt" - "log" "net" "syscall" @@ -33,71 +32,15 @@ func makeVendorClassIdentifier() (string, error) { return fmt.Sprintf("AAPLBSDPC/i386/%s", hwModel), nil } -// ParseBootImagesFromOption parses data from the BSDPOptionBootImageList -// option and returns a list of BootImages. -func ParseBootImagesFromOption(data []byte) ([]BootImage, error) { - // Should at least have the # bytes of boot images. - if len(data) < 4 { - return nil, fmt.Errorf("invalid length boot image list") - } - - var ( - readByteCount = 0 - start = data - bootImages []BootImage - ) - for { - bootImage, err := BootImageFromBytes(start) - if err != nil { - return nil, err - } - bootImages = append(bootImages, *bootImage) - // Read BootImageID + name length + name - readByteCount += 4 + 1 + len(bootImage.Name) - if readByteCount+1 >= len(data) { - break - } - start = start[readByteCount:] - } - - return bootImages, nil -} - -// ParseVendorOptionsFromOptions extracts the sub-options list of the vendor- -// specific options from the larger DHCP options list. -// TODO: Implement options.GetOneOption for dhcpv4. -func ParseVendorOptionsFromOptions(options []dhcpv4.Option) []dhcpv4.Option { - var ( - vendorOpts []dhcpv4.Option - err error - ) - for _, opt := range options { - if opt.Code() == dhcpv4.OptionVendorSpecificInformation { - vendorOpts, err = dhcpv4.OptionsFromBytesWithoutMagicCookie(opt.(*dhcpv4.OptionGeneric).Data) - if err != nil { - log.Println("Warning: could not parse vendor options in DHCP options") - return []dhcpv4.Option{} - } - break - } - } - return vendorOpts -} - // ParseBootImageListFromAck parses the list of boot images presented in the // ACK[LIST] packet and returns them as a list of BootImages. func ParseBootImageListFromAck(ack dhcpv4.DHCPv4) ([]BootImage, error) { var bootImages []BootImage - for _, opt := range ParseVendorOptionsFromOptions(ack.Options()) { - if opt.Code() == OptionBootImageList { - images, err := ParseBootImagesFromOption(opt.(*dhcpv4.OptionGeneric).Data) - if err != nil { - return nil, err - } - bootImages = append(bootImages, images...) - } + o := ack.GetOption(dhcpv4.OptionVendorSpecificInformation) + vendorOpt := o.(*OptVendorSpecificInformation) + for _, o := range vendorOpt.GetOptions(OptionBootImageList) { + bootImages = append(bootImages, o.(*OptBootImageList).BootImages...) } - return bootImages, nil } @@ -123,21 +66,13 @@ func NewInformListForInterface(iface string, replyPort uint16) (*dhcpv4.DHCPv4, &OptMessageType{MessageTypeList}, &OptVersion{Version1_1}, } - if needsReplyPort(replyPort) { vendorOpts = append(vendorOpts, &OptReplyPort{replyPort}) } - var vendorOptsBytes []byte - for _, opt := range vendorOpts { - vendorOptsBytes = append(vendorOptsBytes, opt.ToBytes()...) - } - d.AddOption(&dhcpv4.OptionGeneric{ - OptionCode: dhcpv4.OptionVendorSpecificInformation, - Data: vendorOptsBytes, - }) + d.AddOption(&OptVendorSpecificInformation{vendorOpts}) d.AddOption(&dhcpv4.OptParameterRequestList{ - RequestedOpts: []dhcpv4.OptionCode{ + []dhcpv4.OptionCode{ dhcpv4.OptionVendorSpecificInformation, dhcpv4.OptionClassIdentifier, }, @@ -194,7 +129,7 @@ func InformSelectForAck(ack dhcpv4.DHCPv4, replyPort uint16, selectedImage BootI if serverIP.To4() == nil { return nil, fmt.Errorf("could not parse server identifier from ACK") } - vendorOpts = append(vendorOpts, &dhcpv4.OptServerIdentifier{ServerID: serverIP}) + vendorOpts = append(vendorOpts, &dhcpv4.OptServerIdentifier{serverIP}) // Validate replyPort if requested. if needsReplyPort(replyPort) { @@ -216,14 +151,7 @@ func InformSelectForAck(ack dhcpv4.DHCPv4, replyPort uint16, selectedImage BootI }, }) d.AddOption(&dhcpv4.OptMessageType{dhcpv4.MessageTypeInform}) - var vendorOptsBytes []byte - for _, opt := range vendorOpts { - vendorOptsBytes = append(vendorOptsBytes, opt.ToBytes()...) - } - d.AddOption(&dhcpv4.OptionGeneric{ - OptionCode: dhcpv4.OptionVendorSpecificInformation, - Data: vendorOptsBytes, - }) + d.AddOption(&OptVendorSpecificInformation{vendorOpts}) d.AddOption(&dhcpv4.OptionGeneric{OptionCode: dhcpv4.OptionEnd}) return d, nil } diff --git a/dhcpv4/bsdp/option_vendor_specific_information.go b/dhcpv4/bsdp/option_vendor_specific_information.go new file mode 100644 index 0000000..b6e27ac --- /dev/null +++ b/dhcpv4/bsdp/option_vendor_specific_information.go @@ -0,0 +1,138 @@ +// +build darwin + +package bsdp + +import ( + "errors" + "fmt" + + "github.com/insomniacslk/dhcp/dhcpv4" +) + +// OptVendorSpecificInformation encapsulates the BSDP-specific options used for +// the protocol. +type OptVendorSpecificInformation struct { + Options []dhcpv4.Option +} + +// parseOption is similar to dhcpv4.ParseOption, except that it switches based +// on the BSDP specific options. +func parseOption(data []byte) (dhcpv4.Option, error) { + if len(data) == 0 { + return nil, dhcpv4.ErrZeroLengthByteStream + } + var ( + opt dhcpv4.Option + err error + ) + switch dhcpv4.OptionCode(data[0]) { + case OptionMessageType: + opt, err = ParseOptMessageType(data) + case OptionVersion: + opt, err = ParseOptVersion(data) + case OptionReplyPort: + opt, err = ParseOptReplyPort(data) + case OptionSelectedBootImageID: + opt, err = ParseOptSelectedBootImageID(data) + default: + opt, err = dhcpv4.ParseOptionGeneric(data) + } + if err != nil { + return nil, err + } + return opt, nil +} + +// ParseOptVendorSpecificInformation constructs an OptVendorSpecificInformation struct from a sequence of +// bytes and returns it, or an error. +func ParseOptVendorSpecificInformation(data []byte) (*OptVendorSpecificInformation, error) { + // Should at least have code + length + if len(data) < 2 { + return nil, dhcpv4.ErrShortByteStream + } + code := dhcpv4.OptionCode(data[0]) + if code != dhcpv4.OptionVendorSpecificInformation { + return nil, fmt.Errorf("expected option %v, got %v instead", dhcpv4.OptionVendorSpecificInformation, code) + } + length := int(data[1]) + if len(data) < length+2 { + return nil, fmt.Errorf("expected length 2, got %d instead", length) + } + + options := make([]dhcpv4.Option, 0, 10) + idx := 0 + for { + if idx == len(data) { + break + } + // This should never happen. + if idx > len(data) { + return nil, errors.New("read past the end of options") + } + opt, err := parseOption(data[idx:]) + if err != nil { + return nil, err + } + options = append(options, opt) + + // Account for code + length bytes + idx += 2 + opt.Length() + } + + return &OptVendorSpecificInformation{options}, nil +} + +// Code returns the option code. +func (o *OptVendorSpecificInformation) Code() dhcpv4.OptionCode { + return dhcpv4.OptionVendorSpecificInformation +} + +// ToBytes returns a serialized stream of bytes for this option. +func (o *OptVendorSpecificInformation) ToBytes() []byte { + bs := []byte{byte(o.Code()), byte(o.Length())} + + // Append data section + for _, opt := range o.Options { + bs = append(bs, opt.ToBytes()...) + } + return bs +} + +// String returns a human-readable string for this option. +func (o *OptVendorSpecificInformation) String() string { + s := "Vendor Specific Information ->\n" + for _, opt := range o.Options { + s += " " + opt.String() + "\n" + } + return s +} + +// Length returns the length of the data portion of this option. Take into +// account code + data length bytes for each sub option. +func (o *OptVendorSpecificInformation) Length() int { + var length int + for _, opt := range o.Options { + length += 2 + opt.Length() + } + return length +} + +// GetOptions returns all suboptions that match the given OptionCode code. +func (o *OptVendorSpecificInformation) GetOptions(code dhcpv4.OptionCode) []dhcpv4.Option { + var opts []dhcpv4.Option + for _, opt := range o.Options { + if o.Code() == code { + opts = append(opts, opt) + } + } + return opts +} + +// GetOption returns the first suboption that matches the OptionCode code. +func (o *OptVendorSpecificInformation) GetOption(code dhcpv4.OptionCode) dhcpv4.Option { + opts := o.GetOptions(code) + if len(opts) == 0 { + return nil + } + return opts[0] +} diff --git a/dhcpv4/bsdp/types.go b/dhcpv4/bsdp/types.go index d04d6ef..691c903 100644 --- a/dhcpv4/bsdp/types.go +++ b/dhcpv4/bsdp/types.go @@ -25,18 +25,18 @@ const ( // OptionCodeToString maps BSDP OptionCodes to human-readable strings // describing what they are. var OptionCodeToString = map[dhcpv4.OptionCode]string{ - OptionMessageType: " Message Type", - OptionVersion: " Version", - OptionServerIdentifier: " Server Identifier", - OptionServerPriority: " Server Priority", - OptionReplyPort: " Reply Port", + OptionMessageType: "Message Type", + OptionVersion: "Version", + OptionServerIdentifier: "Server Identifier", + OptionServerPriority: "Server Priority", + OptionReplyPort: "Reply Port", OptionBootImageListPath: "", // Not used - OptionDefaultBootImageID: " Default Boot Image ID", - OptionSelectedBootImageID: " Selected Boot Image ID", - OptionBootImageList: " Boot Image List", - OptionNetboot1_0Firmware: " Netboot 1.0 Firmware", - OptionBootImageAttributesFilterList: " Boot Image Attributes Filter List", - OptionShadowMountPath: " Shadow Mount Path", - OptionShadowFilePath: " Shadow File Path", - OptionMachineName: " Machine Name", + OptionDefaultBootImageID: "Default Boot Image ID", + OptionSelectedBootImageID: "Selected Boot Image ID", + OptionBootImageList: "Boot Image List", + OptionNetboot1_0Firmware: "Netboot 1.0 Firmware", + OptionBootImageAttributesFilterList: "Boot Image Attributes Filter List", + OptionShadowMountPath: "Shadow Mount Path", + OptionShadowFilePath: "Shadow File Path", + OptionMachineName: "Machine Name", } |