diff options
Diffstat (limited to 'dhcpv4/dhcpv4.go')
| -rw-r--r-- | dhcpv4/dhcpv4.go | 67 |
1 files changed, 18 insertions, 49 deletions
diff --git a/dhcpv4/dhcpv4.go b/dhcpv4/dhcpv4.go index f4e3596..429d404 100644 --- a/dhcpv4/dhcpv4.go +++ b/dhcpv4/dhcpv4.go @@ -124,8 +124,6 @@ func New() (*DHCPv4, error) { GatewayIPAddr: net.IPv4zero, Options: make([]Option, 0, 10), } - // the End option has to be added explicitly - d.AddOption(&OptionGeneric{OptionCode: OptionEnd}) return &d, nil } @@ -152,8 +150,8 @@ func NewDiscovery(hwaddr net.HardwareAddr) (*DHCPv4, error) { d.HWType = iana.HWTypeEthernet d.ClientHWAddr = hwaddr d.SetBroadcast() - d.AddOption(&OptMessageType{MessageType: MessageTypeDiscover}) - d.AddOption(&OptParameterRequestList{ + d.UpdateOption(&OptMessageType{MessageType: MessageTypeDiscover}) + d.UpdateOption(&OptParameterRequestList{ RequestedOpts: []OptionCode{ OptionSubnetMask, OptionRouter, @@ -205,7 +203,7 @@ func NewInform(hwaddr net.HardwareAddr, localIP net.IP) (*DHCPv4, error) { d.HWType = iana.HWTypeEthernet d.ClientHWAddr = hwaddr d.ClientIPAddr = localIP - d.AddOption(&OptMessageType{MessageType: MessageTypeInform}) + d.UpdateOption(&OptMessageType{MessageType: MessageTypeInform}) return d, nil } @@ -235,9 +233,9 @@ func NewRequestFromOffer(offer *DHCPv4, modifiers ...Modifier) (*DHCPv4, error) return nil, errors.New("Missing Server IP Address in DHCP Offer") } d.ServerIPAddr = serverIP - d.AddOption(&OptMessageType{MessageType: MessageTypeRequest}) - d.AddOption(&OptRequestedIPAddress{RequestedAddr: offer.YourIPAddr}) - d.AddOption(&OptServerIdentifier{ServerID: serverIP}) + d.UpdateOption(&OptMessageType{MessageType: MessageTypeRequest}) + d.UpdateOption(&OptRequestedIPAddress{RequestedAddr: offer.YourIPAddr}) + d.UpdateOption(&OptServerIdentifier{ServerID: serverIP}) for _, mod := range modifiers { d = mod(d) } @@ -359,48 +357,17 @@ func (d *DHCPv4) SetUnicast() { d.Flags &= ^uint16(0x8000) } -// GetOption will attempt to get all options that match a DHCPv4 option -// from its OptionCode. If the option was not found it will return an -// empty list. +// GetOneOption returns the option that matches the given option code. // -// According to RFC 3396, options that are specified more than once are -// concatenated, and hence this should always just return one option. -func (d *DHCPv4) GetOption(code OptionCode) []Option { - return d.Options.Get(code) -} - -// GetOneOption will attempt to get an option that match a Option code. -// If there are multiple options with the same OptionCode it will only return -// the first one found. If no matching option is found nil will be returned. +// If no matching option is found, nil is returned. func (d *DHCPv4) GetOneOption(code OptionCode) Option { return d.Options.GetOne(code) } -// AddOption appends an option to the existing ones. If the last option is an -// OptionEnd, it will be inserted before that. It does not deal with End -// options that appead before the end, like in malformed packets. -func (d *DHCPv4) AddOption(option Option) { - if len(d.Options) == 0 || d.Options[len(d.Options)-1].Code() != OptionEnd { - d.Options = append(d.Options, option) - } else { - end := d.Options[len(d.Options)-1] - d.Options[len(d.Options)-1] = option - d.Options = append(d.Options, end) - } -} - -// UpdateOption updates the existing options with the passed option, adding it -// at the end if not present already +// UpdateOption replaces an existing option with the same option code with the +// given one, adding it if not already present. func (d *DHCPv4) UpdateOption(option Option) { - for idx, opt := range d.Options { - if opt.Code() == option.Code() { - d.Options[idx] = option - // don't look further - return - } - } - // if not found, add it - d.AddOption(option) + d.Options.Update(option) } // MessageType returns the message type, trying to extract it from the @@ -474,11 +441,13 @@ func (d *DHCPv4) Summary() string { // IsOptionRequested returns true if that option is within the requested // options of the DHCPv4 message. func (d *DHCPv4) IsOptionRequested(requested OptionCode) bool { - for _, optprl := range d.GetOption(OptionParameterRequestList) { - for _, o := range optprl.(*OptParameterRequestList).RequestedOpts { - if o == requested { - return true - } + optprl := d.GetOneOption(OptionParameterRequestList) + if optprl == nil { + return false + } + for _, o := range optprl.(*OptParameterRequestList).RequestedOpts { + if o == requested { + return true } } return false |