From 79b8450e99efee338596f15fc1f8f88c3e42edc0 Mon Sep 17 00:00:00 2001 From: Sean Karlage Date: Fri, 16 Mar 2018 08:42:29 -0700 Subject: Add more specific dhcpv4 options (#17) Added several DHCPv4 options --- dhcpv4/option_server_identifier.go | 56 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 dhcpv4/option_server_identifier.go (limited to 'dhcpv4/option_server_identifier.go') diff --git a/dhcpv4/option_server_identifier.go b/dhcpv4/option_server_identifier.go new file mode 100644 index 0000000..26c21a7 --- /dev/null +++ b/dhcpv4/option_server_identifier.go @@ -0,0 +1,56 @@ +package dhcpv4 + +import ( + "fmt" + "net" +) + +// This option implements the server identifier option +// https://tools.ietf.org/html/rfc2132 + +// OptServerIdentifier represents an option encapsulating the server identifier. +type OptServerIdentifier struct { + ServerID net.IP +} + +// ParseOptServerIdentifier returns a new OptServerIdentifier from a byte +// stream, or error if any. +func ParseOptServerIdentifier(data []byte) (*OptServerIdentifier, error) { + if len(data) < 2 { + return nil, ErrShortByteStream + } + code := OptionCode(data[0]) + if code != OptionServerIdentifier { + return nil, fmt.Errorf("expected code %v, got %v", OptionServerIdentifier, code) + } + length := int(data[1]) + if length != 4 { + return nil, fmt.Errorf("unexepcted length: expected 4, got %v", length) + } + if len(data) < 6 { + return nil, ErrShortByteStream + } + return &OptServerIdentifier{ServerID: net.IP(data[2 : 2+length])}, nil +} + +// Code returns the option code. +func (o *OptServerIdentifier) Code() OptionCode { + return OptionServerIdentifier +} + +// ToBytes returns a serialized stream of bytes for this option. +func (o *OptServerIdentifier) ToBytes() []byte { + ret := []byte{byte(o.Code()), byte(o.Length())} + return append(ret, o.ServerID.To4()...) +} + +// String returns a human-readable string. +func (o *OptServerIdentifier) String() string { + return fmt.Sprintf("Server Identifier -> %v", o.ServerID.String()) +} + +// Length returns the length of the data portion (excluding option code an byte +// length). +func (o *OptServerIdentifier) Length() int { + return len(o.ServerID.To4()) +} -- cgit v1.2.3