Remove dhcp client

This was upstreamed from Fuchsia, but it is pretty buggy and doesn't
rely on any private APIs. Thus it can be checked into the Fuchsia source
tree without forking netstack, where we can more easily iterate on (and
eventually remove) it.

PiperOrigin-RevId: 247506582
Change-Id: Ifb1b60c6c4941c374a59c5570a6a9cacf2468981

1 files changed, 0 insertions, 280 deletions

diff --git a/pkg/dhcp/dhcp.go b/pkg/dhcp/dhcp.go
deleted file mode 100644
index f96ffd891..000000000
--- a/pkg/dhcp/dhcp.go
+++ /dev/null
@@ -1,280 +0,0 @@
-// Copyright 2018 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Package dhcp implements a DHCP client and server as described in RFC 2131.
-package dhcp
-
-import (
-	"bytes"
-	"encoding/binary"
-	"fmt"
-	"time"
-
-	"gvisor.googlesource.com/gvisor/pkg/tcpip"
-)
-
-// Config is standard DHCP configuration.
-type Config struct {
-	Error         error
-	ServerAddress tcpip.Address     // address of the server
-	SubnetMask    tcpip.AddressMask // client address subnet mask
-	Gateway       tcpip.Address     // client default gateway
-	DNS           []tcpip.Address   // client DNS server addresses
-	LeaseLength   time.Duration     // length of the address lease
-}
-
-func (cfg *Config) decode(opts []option) error {
-	*cfg = Config{}
-	for _, opt := range opts {
-		b := opt.body
-		if !opt.code.lenValid(len(b)) {
-			return fmt.Errorf("%s: bad length: %d", opt.code, len(b))
-		}
-		switch opt.code {
-		case optLeaseTime:
-			t := binary.BigEndian.Uint32(b)
-			cfg.LeaseLength = time.Duration(t) * time.Second
-		case optSubnetMask:
-			cfg.SubnetMask = tcpip.AddressMask(b)
-		case optDHCPServer:
-			cfg.ServerAddress = tcpip.Address(b)
-		case optDefaultGateway:
-			cfg.Gateway = tcpip.Address(b)
-		case optDomainNameServer:
-			for ; len(b) > 0; b = b[4:] {
-				if len(b) < 4 {
-					return fmt.Errorf("DNS bad length: %d", len(b))
-				}
-				cfg.DNS = append(cfg.DNS, tcpip.Address(b[:4]))
-			}
-		}
-	}
-	return nil
-}
-
-func (cfg Config) encode() (opts []option) {
-	if cfg.ServerAddress != "" {
-		opts = append(opts, option{optDHCPServer, []byte(cfg.ServerAddress)})
-	}
-	if cfg.SubnetMask != "" {
-		opts = append(opts, option{optSubnetMask, []byte(cfg.SubnetMask)})
-	}
-	if cfg.Gateway != "" {
-		opts = append(opts, option{optDefaultGateway, []byte(cfg.Gateway)})
-	}
-	if len(cfg.DNS) > 0 {
-		dns := make([]byte, 0, 4*len(cfg.DNS))
-		for _, addr := range cfg.DNS {
-			dns = append(dns, addr...)
-		}
-		opts = append(opts, option{optDomainNameServer, dns})
-	}
-	if l := cfg.LeaseLength / time.Second; l != 0 {
-		v := make([]byte, 4)
-		v[0] = byte(l >> 24)
-		v[1] = byte(l >> 16)
-		v[2] = byte(l >> 8)
-		v[3] = byte(l >> 0)
-		opts = append(opts, option{optLeaseTime, v})
-	}
-	return opts
-}
-
-const (
-	// ServerPort is the well-known UDP port number for a DHCP server.
-	ServerPort = 67
-	// ClientPort is the well-known UDP port number for a DHCP client.
-	ClientPort = 68
-)
-
-var magicCookie = []byte{99, 130, 83, 99} // RFC 1497
-
-type xid uint32
-
-type header []byte
-
-func (h header) init() {
-	h[1] = 0x01       // htype
-	h[2] = 0x06       // hlen
-	h[3] = 0x00       // hops
-	h[8], h[9] = 0, 0 // secs
-	copy(h[236:240], magicCookie)
-}
-
-func (h header) isValid() bool {
-	if len(h) < 241 {
-		return false
-	}
-	if o := h.op(); o != opRequest && o != opReply {
-		return false
-	}
-	if h[1] != 0x01 || h[2] != 0x06 {
-		return false
-	}
-	return bytes.Equal(h[236:240], magicCookie)
-}
-
-func (h header) op() op           { return op(h[0]) }
-func (h header) setOp(o op)       { h[0] = byte(o) }
-func (h header) xidbytes() []byte { return h[4:8] }
-func (h header) xid() xid         { return xid(h[4])<<24 | xid(h[5])<<16 | xid(h[6])<<8 | xid(h[7]) }
-func (h header) setBroadcast()    { h[10], h[11] = 0x80, 0x00 } // flags top bit
-func (h header) ciaddr() []byte   { return h[12:16] }
-func (h header) yiaddr() []byte   { return h[16:20] }
-func (h header) siaddr() []byte   { return h[20:24] }
-func (h header) giaddr() []byte   { return h[24:28] }
-func (h header) chaddr() []byte   { return h[28:44] }
-func (h header) sname() []byte    { return h[44:108] }
-func (h header) file() []byte     { return h[108:236] }
-
-func (h header) options() (opts options, err error) {
-	i := headerBaseSize
-	for i < len(h) {
-		if h[i] == 0 {
-			i++
-			continue
-		}
-		if h[i] == 255 {
-			break
-		}
-		if len(h) <= i+1 {
-			return nil, fmt.Errorf("option missing length")
-		}
-		optlen := int(h[i+1])
-		if len(h) < i+2+optlen {
-			return nil, fmt.Errorf("option %v too long i=%d, optlen=%d", optionCode(h[i]), i, optlen)
-		}
-		opts = append(opts, option{
-			code: optionCode(h[i]),
-			body: h[i+2 : i+2+optlen],
-		})
-		i += 2 + optlen
-	}
-	return opts, nil
-}
-
-func (h header) setOptions(opts []option) {
-	i := headerBaseSize
-	for _, opt := range opts {
-		h[i] = byte(opt.code)
-		h[i+1] = byte(len(opt.body))
-		copy(h[i+2:i+2+len(opt.body)], opt.body)
-		i += 2 + len(opt.body)
-	}
-	h[i] = 255 // End option
-	i++
-	for ; i < len(h); i++ {
-		h[i] = 0
-	}
-}
-
-// headerBaseSize is the size of a DHCP packet, including the magic cookie.
-//
-// Note that a DHCP packet is required to have an 'end' option that takes
-// up an extra byte, so the minimum DHCP packet size is headerBaseSize + 1.
-const headerBaseSize = 240
-
-type option struct {
-	code optionCode
-	body []byte
-}
-
-type optionCode byte
-
-const (
-	optSubnetMask       optionCode = 1
-	optDefaultGateway   optionCode = 3
-	optDomainNameServer optionCode = 6
-	optDomainName       optionCode = 15
-	optReqIPAddr        optionCode = 50
-	optLeaseTime        optionCode = 51
-	optDHCPMsgType      optionCode = 53 // dhcpMsgType
-	optDHCPServer       optionCode = 54
-	optParamReq         optionCode = 55
-	optMessage          optionCode = 56
-	optClientID         optionCode = 61
-)
-
-func (code optionCode) lenValid(l int) bool {
-	switch code {
-	case optSubnetMask, optDefaultGateway,
-		optReqIPAddr, optLeaseTime, optDHCPServer:
-		return l == 4
-	case optDHCPMsgType:
-		return l == 1
-	case optDomainNameServer:
-		return l%4 == 0
-	case optMessage, optDomainName, optClientID:
-		return l >= 1
-	case optParamReq:
-		return true // no fixed length
-	default:
-		return true // unknown option, assume ok
-	}
-}
-
-type options []option
-
-func (opts options) dhcpMsgType() (dhcpMsgType, error) {
-	for _, opt := range opts {
-		if opt.code == optDHCPMsgType {
-			if len(opt.body) != 1 {
-				return 0, fmt.Errorf("%s: bad length: %d", opt.code, len(opt.body))
-			}
-			v := opt.body[0]
-			if v <= 0 || v >= 8 {
-				return 0, fmt.Errorf("DHCP bad length: %d", len(opt.body))
-			}
-			return dhcpMsgType(v), nil
-		}
-	}
-	return 0, nil
-}
-
-func (opts options) message() string {
-	for _, opt := range opts {
-		if opt.code == optMessage {
-			return string(opt.body)
-		}
-	}
-	return ""
-}
-
-func (opts options) len() int {
-	l := 0
-	for _, opt := range opts {
-		l += 1 + 1 + len(opt.body) // code + len + body
-	}
-	return l + 1 // extra byte for 'pad' option
-}
-
-type op byte
-
-const (
-	opRequest op = 0x01
-	opReply   op = 0x02
-)
-
-// dhcpMsgType is the DHCP Message Type from RFC 1533, section 9.4.
-type dhcpMsgType byte
-
-const (
-	dhcpDISCOVER dhcpMsgType = 1
-	dhcpOFFER    dhcpMsgType = 2
-	dhcpREQUEST  dhcpMsgType = 3
-	dhcpDECLINE  dhcpMsgType = 4
-	dhcpACK      dhcpMsgType = 5
-	dhcpNAK      dhcpMsgType = 6
-	dhcpRELEASE  dhcpMsgType = 7
-)