"Comment": "v2-53-g2688e91",
"Rev": "2688e91251d9d8e404e86dd8f096e23b2f086958"
},
+ {
+ "ImportPath": "github.com/d2g/dhcp4",
+ "Rev": "f0e4d29ff0231dce36e250b2ed9ff08412584bca"
+ },
+ {
+ "ImportPath": "github.com/d2g/dhcp4client",
+ "Rev": "bed07e1bc5b85f69c6f0fd73393aa35ec68ed892"
+ },
{
"ImportPath": "github.com/onsi/ginkgo",
"Comment": "v1.2.0-29-g7f8ab55",
--- /dev/null
+Copyright (c) 2013 Skagerrak Software Limited. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+ * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+ * Neither the name of Skagerrak Software Limited nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\ No newline at end of file
--- /dev/null
+# DHCP4 - A DHCP library written in Go.
+
+Warning: This library is still being developed. Function calls will change.
+
+I've removed Server Functionality, for me this project supports the underlying DHCP format not the implementation.
--- /dev/null
+package dhcp4
+
+// OpCodes
+const (
+ BootRequest OpCode = 1 // From Client
+ BootReply OpCode = 2 // From Server
+)
+
+// DHCP Message Type 53
+const (
+ Discover MessageType = 1 // Broadcast Packet From Client - Can I have an IP?
+ Offer MessageType = 2 // Broadcast From Server - Here's an IP
+ Request MessageType = 3 // Broadcast From Client - I'll take that IP (Also start for renewals)
+ Decline MessageType = 4 // Broadcast From Client - Sorry I can't use that IP
+ ACK MessageType = 5 // From Server, Yes you can have that IP
+ NAK MessageType = 6 // From Server, No you cannot have that IP
+ Release MessageType = 7 // From Client, I don't need that IP anymore
+ Inform MessageType = 8 // From Client, I have this IP and there's nothing you can do about it
+)
+
+// DHCP Options
+const (
+ End OptionCode = 255
+ Pad OptionCode = 0
+ OptionSubnetMask OptionCode = 1
+ OptionTimeOffset OptionCode = 2
+ OptionRouter OptionCode = 3
+ OptionTimeServer OptionCode = 4
+ OptionNameServer OptionCode = 5
+ OptionDomainNameServer OptionCode = 6
+ OptionLogServer OptionCode = 7
+ OptionCookieServer OptionCode = 8
+ OptionLPRServer OptionCode = 9
+ OptionImpressServer OptionCode = 10
+ OptionResourceLocationServer OptionCode = 11
+ OptionHostName OptionCode = 12
+ OptionBootFileSize OptionCode = 13
+ OptionMeritDumpFile OptionCode = 14
+ OptionDomainName OptionCode = 15
+ OptionSwapServer OptionCode = 16
+ OptionRootPath OptionCode = 17
+ OptionExtensionsPath OptionCode = 18
+
+ // IP Layer Parameters per Host
+ OptionIPForwardingEnableDisable OptionCode = 19
+ OptionNonLocalSourceRoutingEnableDisable OptionCode = 20
+ OptionPolicyFilter OptionCode = 21
+ OptionMaximumDatagramReassemblySize OptionCode = 22
+ OptionDefaultIPTimeToLive OptionCode = 23
+ OptionPathMTUAgingTimeout OptionCode = 24
+ OptionPathMTUPlateauTable OptionCode = 25
+
+ // IP Layer Parameters per Interface
+ OptionInterfaceMTU OptionCode = 26
+ OptionAllSubnetsAreLocal OptionCode = 27
+ OptionBroadcastAddress OptionCode = 28
+ OptionPerformMaskDiscovery OptionCode = 29
+ OptionMaskSupplier OptionCode = 30
+ OptionPerformRouterDiscovery OptionCode = 31
+ OptionRouterSolicitationAddress OptionCode = 32
+ OptionStaticRoute OptionCode = 33
+
+ // Link Layer Parameters per Interface
+ OptionTrailerEncapsulation OptionCode = 34
+ OptionARPCacheTimeout OptionCode = 35
+ OptionEthernetEncapsulation OptionCode = 36
+
+ // TCP Parameters
+ OptionTCPDefaultTTL OptionCode = 37
+ OptionTCPKeepaliveInterval OptionCode = 38
+ OptionTCPKeepaliveGarbage OptionCode = 39
+
+ // Application and Service Parameters
+ OptionNetworkInformationServiceDomain OptionCode = 40
+ OptionNetworkInformationServers OptionCode = 41
+ OptionNetworkTimeProtocolServers OptionCode = 42
+ OptionVendorSpecificInformation OptionCode = 43
+ OptionNetBIOSOverTCPIPNameServer OptionCode = 44
+ OptionNetBIOSOverTCPIPDatagramDistributionServer OptionCode = 45
+ OptionNetBIOSOverTCPIPNodeType OptionCode = 46
+ OptionNetBIOSOverTCPIPScope OptionCode = 47
+ OptionXWindowSystemFontServer OptionCode = 48
+ OptionXWindowSystemDisplayManager OptionCode = 49
+ OptionNetworkInformationServicePlusDomain OptionCode = 64
+ OptionNetworkInformationServicePlusServers OptionCode = 65
+ OptionMobileIPHomeAgent OptionCode = 68
+ OptionSimpleMailTransportProtocol OptionCode = 69
+ OptionPostOfficeProtocolServer OptionCode = 70
+ OptionNetworkNewsTransportProtocol OptionCode = 71
+ OptionDefaultWorldWideWebServer OptionCode = 72
+ OptionDefaultFingerServer OptionCode = 73
+ OptionDefaultInternetRelayChatServer OptionCode = 74
+ OptionStreetTalkServer OptionCode = 75
+ OptionStreetTalkDirectoryAssistance OptionCode = 76
+
+ // DHCP Extensions
+ OptionRequestedIPAddress OptionCode = 50
+ OptionIPAddressLeaseTime OptionCode = 51
+ OptionOverload OptionCode = 52
+ OptionDHCPMessageType OptionCode = 53
+ OptionServerIdentifier OptionCode = 54
+ OptionParameterRequestList OptionCode = 55
+ OptionMessage OptionCode = 56
+ OptionMaximumDHCPMessageSize OptionCode = 57
+ OptionRenewalTimeValue OptionCode = 58
+ OptionRebindingTimeValue OptionCode = 59
+ OptionVendorClassIdentifier OptionCode = 60
+ OptionClientIdentifier OptionCode = 61
+
+ OptionTFTPServerName OptionCode = 66
+ OptionBootFileName OptionCode = 67
+
+ OptionUserClass OptionCode = 77
+
+ OptionClientArchitecture OptionCode = 93
+
+ OptionTZPOSIXString OptionCode = 100
+ OptionTZDatabaseString OptionCode = 101
+
+ OptionClasslessRouteFormat OptionCode = 121
+)
--- /dev/null
+package dhcp4
+
+import (
+ "encoding/binary"
+ "net"
+ "time"
+)
+
+// IPRange returns how many ips in the ip range from start to stop (inclusive)
+func IPRange(start, stop net.IP) int {
+ //return int(Uint([]byte(stop))-Uint([]byte(start))) + 1
+ return int(binary.BigEndian.Uint32(stop.To4())) - int(binary.BigEndian.Uint32(start.To4())) + 1
+}
+
+// IPAdd returns a copy of start + add.
+// IPAdd(net.IP{192,168,1,1},30) returns net.IP{192.168.1.31}
+func IPAdd(start net.IP, add int) net.IP { // IPv4 only
+ start = start.To4()
+ //v := Uvarint([]byte(start))
+ result := make(net.IP, 4)
+ binary.BigEndian.PutUint32(result, binary.BigEndian.Uint32(start)+uint32(add))
+ //PutUint([]byte(result), v+uint64(add))
+ return result
+}
+
+// IPLess returns where IP a is less than IP b.
+func IPLess(a, b net.IP) bool {
+ b = b.To4()
+ for i, ai := range a.To4() {
+ if ai != b[i] {
+ return ai < b[i]
+ }
+ }
+ return false
+}
+
+// IPInRange returns true if ip is between (inclusive) start and stop.
+func IPInRange(start, stop, ip net.IP) bool {
+ return !(IPLess(ip, start) || IPLess(stop, ip))
+}
+
+// OptionsLeaseTime - converts a time.Duration to a 4 byte slice, compatible
+// with OptionIPAddressLeaseTime.
+func OptionsLeaseTime(d time.Duration) []byte {
+ leaseBytes := make([]byte, 4)
+ binary.BigEndian.PutUint32(leaseBytes, uint32(d/time.Second))
+ //PutUvarint(leaseBytes, uint64(d/time.Second))
+ return leaseBytes
+}
+
+// JoinIPs returns a byte slice of IP addresses, one immediately after the other
+// This may be useful for creating multiple IP options such as OptionRouter.
+func JoinIPs(ips []net.IP) (b []byte) {
+ for _, v := range ips {
+ b = append(b, v.To4()...)
+ }
+ return
+}
--- /dev/null
+package dhcp4
+
+type OptionCode byte
+
+type Option struct {
+ Code OptionCode
+ Value []byte
+}
+
+// Map of DHCP options
+type Options map[OptionCode][]byte
+
+// SelectOrderOrAll has same functionality as SelectOrder, except if the order
+// param is nil, whereby all options are added (in arbitary order).
+func (o Options) SelectOrderOrAll(order []byte) []Option {
+ if order == nil {
+ opts := make([]Option, 0, len(o))
+ for i, v := range o {
+ opts = append(opts, Option{Code: i, Value: v})
+ }
+ return opts
+ }
+ return o.SelectOrder(order)
+}
+
+// SelectOrder returns a slice of options ordered and selected by a byte array
+// usually defined by OptionParameterRequestList. This result is expected to be
+// used in ReplyPacket()'s []Option parameter.
+func (o Options) SelectOrder(order []byte) []Option {
+ opts := make([]Option, 0, len(order))
+ for _, v := range order {
+ if data, ok := o[OptionCode(v)]; ok {
+ opts = append(opts, Option{Code: OptionCode(v), Value: data})
+ }
+ }
+ return opts
+}
+
+type OpCode byte
+type MessageType byte // Option 53
--- /dev/null
+package dhcp4
+
+import (
+ "net"
+ "time"
+)
+
+// A DHCP packet
+type Packet []byte
+
+func (p Packet) OpCode() OpCode { return OpCode(p[0]) }
+func (p Packet) HType() byte { return p[1] }
+func (p Packet) HLen() byte { return p[2] }
+func (p Packet) Hops() byte { return p[3] }
+func (p Packet) XId() []byte { return p[4:8] }
+func (p Packet) Secs() []byte { return p[8:10] } // Never Used?
+func (p Packet) Flags() []byte { return p[10:12] }
+func (p Packet) CIAddr() net.IP { return net.IP(p[12:16]) }
+func (p Packet) YIAddr() net.IP { return net.IP(p[16:20]) }
+func (p Packet) SIAddr() net.IP { return net.IP(p[20:24]) }
+func (p Packet) GIAddr() net.IP { return net.IP(p[24:28]) }
+func (p Packet) CHAddr() net.HardwareAddr {
+ hLen := p.HLen()
+ if hLen > 16 { // Prevent chaddr exceeding p boundary
+ hLen = 16
+ }
+ return net.HardwareAddr(p[28 : 28+hLen]) // max endPos 44
+}
+
+// 192 bytes of zeros BOOTP legacy
+func (p Packet) Cookie() []byte { return p[236:240] }
+func (p Packet) Options() []byte {
+ if len(p) > 240 {
+ return p[240:]
+ }
+ return nil
+}
+
+func (p Packet) Broadcast() bool { return p.Flags()[0] > 127 }
+
+func (p Packet) SetBroadcast(broadcast bool) {
+ if p.Broadcast() != broadcast {
+ p.Flags()[0] ^= 128
+ }
+}
+
+func (p Packet) SetOpCode(c OpCode) { p[0] = byte(c) }
+func (p Packet) SetCHAddr(a net.HardwareAddr) {
+ copy(p[28:44], a)
+ p[2] = byte(len(a))
+}
+func (p Packet) SetHType(hType byte) { p[1] = hType }
+func (p Packet) SetCookie(cookie []byte) { copy(p.Cookie(), cookie) }
+func (p Packet) SetHops(hops byte) { p[3] = hops }
+func (p Packet) SetXId(xId []byte) { copy(p.XId(), xId) }
+func (p Packet) SetSecs(secs []byte) { copy(p.Secs(), secs) }
+func (p Packet) SetFlags(flags []byte) { copy(p.Flags(), flags) }
+func (p Packet) SetCIAddr(ip net.IP) { copy(p.CIAddr(), ip.To4()) }
+func (p Packet) SetYIAddr(ip net.IP) { copy(p.YIAddr(), ip.To4()) }
+func (p Packet) SetSIAddr(ip net.IP) { copy(p.SIAddr(), ip.To4()) }
+func (p Packet) SetGIAddr(ip net.IP) { copy(p.GIAddr(), ip.To4()) }
+
+// Parses the packet's options into an Options map
+func (p Packet) ParseOptions() Options {
+ opts := p.Options()
+ options := make(Options, 10)
+ for len(opts) >= 2 && OptionCode(opts[0]) != End {
+ if OptionCode(opts[0]) == Pad {
+ opts = opts[1:]
+ continue
+ }
+ size := int(opts[1])
+ if len(opts) < 2+size {
+ break
+ }
+ options[OptionCode(opts[0])] = opts[2 : 2+size]
+ opts = opts[2+size:]
+ }
+ return options
+}
+
+func NewPacket(opCode OpCode) Packet {
+ p := make(Packet, 241)
+ p.SetOpCode(opCode)
+ p.SetHType(1) // Ethernet
+ p.SetCookie([]byte{99, 130, 83, 99})
+ p[240] = byte(End)
+ return p
+}
+
+// Appends a DHCP option to the end of a packet
+func (p *Packet) AddOption(o OptionCode, value []byte) {
+ *p = append((*p)[:len(*p)-1], []byte{byte(o), byte(len(value))}...) // Strip off End, Add OptionCode and Length
+ *p = append(*p, value...) // Add Option Value
+ *p = append(*p, byte(End)) // Add on new End
+}
+
+// Removes all options from packet.
+func (p *Packet) StripOptions() {
+ *p = append((*p)[:240], byte(End))
+}
+
+// Creates a request packet that a Client would send to a server.
+func RequestPacket(mt MessageType, chAddr net.HardwareAddr, cIAddr net.IP, xId []byte, broadcast bool, options []Option) Packet {
+ p := NewPacket(BootRequest)
+ p.SetCHAddr(chAddr)
+ p.SetXId(xId)
+ if cIAddr != nil {
+ p.SetCIAddr(cIAddr)
+ }
+ p.SetBroadcast(broadcast)
+ p.AddOption(OptionDHCPMessageType, []byte{byte(mt)})
+ for _, o := range options {
+ p.AddOption(o.Code, o.Value)
+ }
+ p.PadToMinSize()
+ return p
+}
+
+// ReplyPacket creates a reply packet that a Server would send to a client.
+// It uses the req Packet param to copy across common/necessary fields to
+// associate the reply the request.
+func ReplyPacket(req Packet, mt MessageType, serverId, yIAddr net.IP, leaseDuration time.Duration, options []Option) Packet {
+ p := NewPacket(BootReply)
+ p.SetXId(req.XId())
+ p.SetFlags(req.Flags())
+ p.SetYIAddr(yIAddr)
+ p.SetGIAddr(req.GIAddr())
+ p.SetCHAddr(req.CHAddr())
+ p.SetSecs(req.Secs())
+ p.AddOption(OptionDHCPMessageType, []byte{byte(mt)})
+ p.AddOption(OptionServerIdentifier, []byte(serverId))
+ p.AddOption(OptionIPAddressLeaseTime, OptionsLeaseTime(leaseDuration))
+ for _, o := range options {
+ p.AddOption(o.Code, o.Value)
+ }
+ p.PadToMinSize()
+ return p
+}
+
+// PadToMinSize pads a packet so that when sent over UDP, the entire packet,
+// is 300 bytes (BOOTP min), to be compatible with really old devices.
+var padder [272]byte
+
+func (p *Packet) PadToMinSize() {
+ if n := len(*p); n < 272 {
+ *p = append(*p, padder[:272-n]...)
+ }
+}
--- /dev/null
+Mozilla Public License, version 2.0
+
+1. Definitions
+
+1.1. “Contributor”
+
+ means each individual or legal entity that creates, contributes to the
+ creation of, or owns Covered Software.
+
+1.2. “Contributor Version”
+
+ means the combination of the Contributions of others (if any) used by a
+ Contributor and that particular Contributor’s Contribution.
+
+1.3. “Contribution”
+
+ means Covered Software of a particular Contributor.
+
+1.4. “Covered Software”
+
+ means Source Code Form to which the initial Contributor has attached the
+ notice in Exhibit A, the Executable Form of such Source Code Form, and
+ Modifications of such Source Code Form, in each case including portions
+ thereof.
+
+1.5. “Incompatible With Secondary Licenses”
+ means
+
+ a. that the initial Contributor has attached the notice described in
+ Exhibit B to the Covered Software; or
+
+ b. that the Covered Software was made available under the terms of version
+ 1.1 or earlier of the License, but not also under the terms of a
+ Secondary License.
+
+1.6. “Executable Form”
+
+ means any form of the work other than Source Code Form.
+
+1.7. “Larger Work”
+
+ means a work that combines Covered Software with other material, in a separate
+ file or files, that is not Covered Software.
+
+1.8. “License”
+
+ means this document.
+
+1.9. “Licensable”
+
+ means having the right to grant, to the maximum extent possible, whether at the
+ time of the initial grant or subsequently, any and all of the rights conveyed by
+ this License.
+
+1.10. “Modifications”
+
+ means any of the following:
+
+ a. any file in Source Code Form that results from an addition to, deletion
+ from, or modification of the contents of Covered Software; or
+
+ b. any new file in Source Code Form that contains any Covered Software.
+
+1.11. “Patent Claims” of a Contributor
+
+ means any patent claim(s), including without limitation, method, process,
+ and apparatus claims, in any patent Licensable by such Contributor that
+ would be infringed, but for the grant of the License, by the making,
+ using, selling, offering for sale, having made, import, or transfer of
+ either its Contributions or its Contributor Version.
+
+1.12. “Secondary License”
+
+ means either the GNU General Public License, Version 2.0, the GNU Lesser
+ General Public License, Version 2.1, the GNU Affero General Public
+ License, Version 3.0, or any later versions of those licenses.
+
+1.13. “Source Code Form”
+
+ means the form of the work preferred for making modifications.
+
+1.14. “You” (or “Your”)
+
+ means an individual or a legal entity exercising rights under this
+ License. For legal entities, “You” includes any entity that controls, is
+ controlled by, or is under common control with You. For purposes of this
+ definition, “control” means (a) the power, direct or indirect, to cause
+ the direction or management of such entity, whether by contract or
+ otherwise, or (b) ownership of more than fifty percent (50%) of the
+ outstanding shares or beneficial ownership of such entity.
+
+
+2. License Grants and Conditions
+
+2.1. Grants
+
+ Each Contributor hereby grants You a world-wide, royalty-free,
+ non-exclusive license:
+
+ a. under intellectual property rights (other than patent or trademark)
+ Licensable by such Contributor to use, reproduce, make available,
+ modify, display, perform, distribute, and otherwise exploit its
+ Contributions, either on an unmodified basis, with Modifications, or as
+ part of a Larger Work; and
+
+ b. under Patent Claims of such Contributor to make, use, sell, offer for
+ sale, have made, import, and otherwise transfer either its Contributions
+ or its Contributor Version.
+
+2.2. Effective Date
+
+ The licenses granted in Section 2.1 with respect to any Contribution become
+ effective for each Contribution on the date the Contributor first distributes
+ such Contribution.
+
+2.3. Limitations on Grant Scope
+
+ The licenses granted in this Section 2 are the only rights granted under this
+ License. No additional rights or licenses will be implied from the distribution
+ or licensing of Covered Software under this License. Notwithstanding Section
+ 2.1(b) above, no patent license is granted by a Contributor:
+
+ a. for any code that a Contributor has removed from Covered Software; or
+
+ b. for infringements caused by: (i) Your and any other third party’s
+ modifications of Covered Software, or (ii) the combination of its
+ Contributions with other software (except as part of its Contributor
+ Version); or
+
+ c. under Patent Claims infringed by Covered Software in the absence of its
+ Contributions.
+
+ This License does not grant any rights in the trademarks, service marks, or
+ logos of any Contributor (except as may be necessary to comply with the
+ notice requirements in Section 3.4).
+
+2.4. Subsequent Licenses
+
+ No Contributor makes additional grants as a result of Your choice to
+ distribute the Covered Software under a subsequent version of this License
+ (see Section 10.2) or under the terms of a Secondary License (if permitted
+ under the terms of Section 3.3).
+
+2.5. Representation
+
+ Each Contributor represents that the Contributor believes its Contributions
+ are its original creation(s) or it has sufficient rights to grant the
+ rights to its Contributions conveyed by this License.
+
+2.6. Fair Use
+
+ This License is not intended to limit any rights You have under applicable
+ copyright doctrines of fair use, fair dealing, or other equivalents.
+
+2.7. Conditions
+
+ Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted in
+ Section 2.1.
+
+
+3. Responsibilities
+
+3.1. Distribution of Source Form
+
+ All distribution of Covered Software in Source Code Form, including any
+ Modifications that You create or to which You contribute, must be under the
+ terms of this License. You must inform recipients that the Source Code Form
+ of the Covered Software is governed by the terms of this License, and how
+ they can obtain a copy of this License. You may not attempt to alter or
+ restrict the recipients’ rights in the Source Code Form.
+
+3.2. Distribution of Executable Form
+
+ If You distribute Covered Software in Executable Form then:
+
+ a. such Covered Software must also be made available in Source Code Form,
+ as described in Section 3.1, and You must inform recipients of the
+ Executable Form how they can obtain a copy of such Source Code Form by
+ reasonable means in a timely manner, at a charge no more than the cost
+ of distribution to the recipient; and
+
+ b. You may distribute such Executable Form under the terms of this License,
+ or sublicense it under different terms, provided that the license for
+ the Executable Form does not attempt to limit or alter the recipients’
+ rights in the Source Code Form under this License.
+
+3.3. Distribution of a Larger Work
+
+ You may create and distribute a Larger Work under terms of Your choice,
+ provided that You also comply with the requirements of this License for the
+ Covered Software. If the Larger Work is a combination of Covered Software
+ with a work governed by one or more Secondary Licenses, and the Covered
+ Software is not Incompatible With Secondary Licenses, this License permits
+ You to additionally distribute such Covered Software under the terms of
+ such Secondary License(s), so that the recipient of the Larger Work may, at
+ their option, further distribute the Covered Software under the terms of
+ either this License or such Secondary License(s).
+
+3.4. Notices
+
+ You may not remove or alter the substance of any license notices (including
+ copyright notices, patent notices, disclaimers of warranty, or limitations
+ of liability) contained within the Source Code Form of the Covered
+ Software, except that You may alter any license notices to the extent
+ required to remedy known factual inaccuracies.
+
+3.5. Application of Additional Terms
+
+ You may choose to offer, and to charge a fee for, warranty, support,
+ indemnity or liability obligations to one or more recipients of Covered
+ Software. However, You may do so only on Your own behalf, and not on behalf
+ of any Contributor. You must make it absolutely clear that any such
+ warranty, support, indemnity, or liability obligation is offered by You
+ alone, and You hereby agree to indemnify every Contributor for any
+ liability incurred by such Contributor as a result of warranty, support,
+ indemnity or liability terms You offer. You may include additional
+ disclaimers of warranty and limitations of liability specific to any
+ jurisdiction.
+
+4. Inability to Comply Due to Statute or Regulation
+
+ If it is impossible for You to comply with any of the terms of this License
+ with respect to some or all of the Covered Software due to statute, judicial
+ order, or regulation then You must: (a) comply with the terms of this License
+ to the maximum extent possible; and (b) describe the limitations and the code
+ they affect. Such description must be placed in a text file included with all
+ distributions of the Covered Software under this License. Except to the
+ extent prohibited by statute or regulation, such description must be
+ sufficiently detailed for a recipient of ordinary skill to be able to
+ understand it.
+
+5. Termination
+
+5.1. The rights granted under this License will terminate automatically if You
+ fail to comply with any of its terms. However, if You become compliant,
+ then the rights granted under this License from a particular Contributor
+ are reinstated (a) provisionally, unless and until such Contributor
+ explicitly and finally terminates Your grants, and (b) on an ongoing basis,
+ if such Contributor fails to notify You of the non-compliance by some
+ reasonable means prior to 60 days after You have come back into compliance.
+ Moreover, Your grants from a particular Contributor are reinstated on an
+ ongoing basis if such Contributor notifies You of the non-compliance by
+ some reasonable means, this is the first time You have received notice of
+ non-compliance with this License from such Contributor, and You become
+ compliant prior to 30 days after Your receipt of the notice.
+
+5.2. If You initiate litigation against any entity by asserting a patent
+ infringement claim (excluding declaratory judgment actions, counter-claims,
+ and cross-claims) alleging that a Contributor Version directly or
+ indirectly infringes any patent, then the rights granted to You by any and
+ all Contributors for the Covered Software under Section 2.1 of this License
+ shall terminate.
+
+5.3. In the event of termination under Sections 5.1 or 5.2 above, all end user
+ license agreements (excluding distributors and resellers) which have been
+ validly granted by You or Your distributors under this License prior to
+ termination shall survive termination.
+
+6. Disclaimer of Warranty
+
+ Covered Software is provided under this License on an “as is” basis, without
+ warranty of any kind, either expressed, implied, or statutory, including,
+ without limitation, warranties that the Covered Software is free of defects,
+ merchantable, fit for a particular purpose or non-infringing. The entire
+ risk as to the quality and performance of the Covered Software is with You.
+ Should any Covered Software prove defective in any respect, You (not any
+ Contributor) assume the cost of any necessary servicing, repair, or
+ correction. This disclaimer of warranty constitutes an essential part of this
+ License. No use of any Covered Software is authorized under this License
+ except under this disclaimer.
+
+7. Limitation of Liability
+
+ Under no circumstances and under no legal theory, whether tort (including
+ negligence), contract, or otherwise, shall any Contributor, or anyone who
+ distributes Covered Software as permitted above, be liable to You for any
+ direct, indirect, special, incidental, or consequential damages of any
+ character including, without limitation, damages for lost profits, loss of
+ goodwill, work stoppage, computer failure or malfunction, or any and all
+ other commercial damages or losses, even if such party shall have been
+ informed of the possibility of such damages. This limitation of liability
+ shall not apply to liability for death or personal injury resulting from such
+ party’s negligence to the extent applicable law prohibits such limitation.
+ Some jurisdictions do not allow the exclusion or limitation of incidental or
+ consequential damages, so this exclusion and limitation may not apply to You.
+
+8. Litigation
+
+ Any litigation relating to this License may be brought only in the courts of
+ a jurisdiction where the defendant maintains its principal place of business
+ and such litigation shall be governed by laws of that jurisdiction, without
+ reference to its conflict-of-law provisions. Nothing in this Section shall
+ prevent a party’s ability to bring cross-claims or counter-claims.
+
+9. Miscellaneous
+
+ This License represents the complete agreement concerning the subject matter
+ hereof. If any provision of this License is held to be unenforceable, such
+ provision shall be reformed only to the extent necessary to make it
+ enforceable. Any law or regulation which provides that the language of a
+ contract shall be construed against the drafter shall not be used to construe
+ this License against a Contributor.
+
+
+10. Versions of the License
+
+10.1. New Versions
+
+ Mozilla Foundation is the license steward. Except as provided in Section
+ 10.3, no one other than the license steward has the right to modify or
+ publish new versions of this License. Each version will be given a
+ distinguishing version number.
+
+10.2. Effect of New Versions
+
+ You may distribute the Covered Software under the terms of the version of
+ the License under which You originally received the Covered Software, or
+ under the terms of any subsequent version published by the license
+ steward.
+
+10.3. Modified Versions
+
+ If you create software not governed by this License, and you want to
+ create a new license for such software, you may create and use a modified
+ version of this License if you rename the license and remove any
+ references to the name of the license steward (except to note that such
+ modified license differs from this License).
+
+10.4. Distributing Source Code Form that is Incompatible With Secondary Licenses
+ If You choose to distribute Source Code Form that is Incompatible With
+ Secondary Licenses under the terms of this version of the License, the
+ notice described in Exhibit B of this License must be attached.
+
+Exhibit A - Source Code Form License Notice
+
+ This Source Code Form is subject to the
+ terms of the Mozilla Public License, v.
+ 2.0. If a copy of the MPL was not
+ distributed with this file, You can
+ obtain one at
+ http://mozilla.org/MPL/2.0/.
+
+If it is not possible or desirable to put the notice in a particular file, then
+You may include the notice in a location (such as a LICENSE file in a relevant
+directory) where a recipient would be likely to look for such a notice.
+
+You may add additional accurate notices of copyright ownership.
+
+Exhibit B - “Incompatible With Secondary Licenses” Notice
+
+ This Source Code Form is “Incompatible
+ With Secondary Licenses”, as defined by
+ the Mozilla Public License, v. 2.0.
+
--- /dev/null
+dhcp4client [](http://godoc.org/github.com/d2g/dhcp4client) [](https://coveralls.io/r/d2g/dhcp4client?branch=HEAD) [](https://codeship.com/projects/70187)
+===========
+
+DHCP Client
+
+
+###### Thanks to:
+@eyakubovich For AF_PACKET support.
--- /dev/null
+package dhcp4client
+
+import (
+ "bytes"
+ "crypto/rand"
+ "net"
+ "time"
+
+ "github.com/d2g/dhcp4"
+)
+
+const (
+ MaxDHCPLen = 576
+)
+
+type Client struct {
+ hardwareAddr net.HardwareAddr //The HardwareAddr to send in the request.
+ ignoreServers []net.IP //List of Servers to Ignore requests from.
+ timeout time.Duration //Time before we timeout.
+ broadcast bool //Set the Bcast flag in BOOTP Flags
+ connection connection //The Connection Method to use
+}
+
+/*
+ * Abstracts the type of underlying socket used
+ */
+type connection interface {
+ Close() error
+ Write(packet []byte) error
+ ReadFrom() ([]byte, net.IP, error)
+ SetReadTimeout(t time.Duration) error
+}
+
+func New(options ...func(*Client) error) (*Client, error) {
+ c := Client{
+ timeout: time.Second * 10,
+ broadcast: true,
+ }
+
+ err := c.SetOption(options...)
+ if err != nil {
+ return nil, err
+ }
+
+ //if connection hasn't been set as an option create the default.
+ if c.connection == nil {
+ conn, err := NewInetSock()
+ if err != nil {
+ return nil, err
+ }
+ c.connection = conn
+ }
+
+ return &c, nil
+}
+
+func (c *Client) SetOption(options ...func(*Client) error) error {
+ for _, opt := range options {
+ if err := opt(c); err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+func Timeout(t time.Duration) func(*Client) error {
+ return func(c *Client) error {
+ c.timeout = t
+ return nil
+ }
+}
+
+func IgnoreServers(s []net.IP) func(*Client) error {
+ return func(c *Client) error {
+ c.ignoreServers = s
+ return nil
+ }
+}
+
+func HardwareAddr(h net.HardwareAddr) func(*Client) error {
+ return func(c *Client) error {
+ c.hardwareAddr = h
+ return nil
+ }
+}
+
+func Broadcast(b bool) func(*Client) error {
+ return func(c *Client) error {
+ c.broadcast = b
+ return nil
+ }
+}
+
+func Connection(conn connection) func(*Client) error {
+ return func(c *Client) error {
+ c.connection = conn
+ return nil
+ }
+}
+
+/*
+ * Close Connections
+ */
+func (c *Client) Close() error {
+ if c.connection != nil {
+ return c.connection.Close()
+ }
+ return nil
+}
+
+/*
+ * Send the Discovery Packet to the Broadcast Channel
+ */
+func (c *Client) SendDiscoverPacket() (dhcp4.Packet, error) {
+ discoveryPacket := c.DiscoverPacket()
+ discoveryPacket.PadToMinSize()
+
+ return discoveryPacket, c.SendPacket(discoveryPacket)
+}
+
+/*
+ * Retreive Offer...
+ * Wait for the offer for a specific Discovery Packet.
+ */
+func (c *Client) GetOffer(discoverPacket *dhcp4.Packet) (dhcp4.Packet, error) {
+ for {
+ c.connection.SetReadTimeout(c.timeout)
+ readBuffer, source, err := c.connection.ReadFrom()
+ if err != nil {
+ return dhcp4.Packet{}, err
+ }
+
+ offerPacket := dhcp4.Packet(readBuffer)
+ offerPacketOptions := offerPacket.ParseOptions()
+
+ // Ignore Servers in my Ignore list
+ for _, ignoreServer := range c.ignoreServers {
+ if source.Equal(ignoreServer) {
+ continue
+ }
+
+ if offerPacket.SIAddr().Equal(ignoreServer) {
+ continue
+ }
+ }
+
+ if len(offerPacketOptions[dhcp4.OptionDHCPMessageType]) < 1 || dhcp4.MessageType(offerPacketOptions[dhcp4.OptionDHCPMessageType][0]) != dhcp4.Offer || !bytes.Equal(discoverPacket.XId(), offerPacket.XId()) {
+ continue
+ }
+
+ return offerPacket, nil
+ }
+
+}
+
+/*
+ * Send Request Based On the offer Received.
+ */
+func (c *Client) SendRequest(offerPacket *dhcp4.Packet) (dhcp4.Packet, error) {
+ requestPacket := c.RequestPacket(offerPacket)
+ requestPacket.PadToMinSize()
+
+ return requestPacket, c.SendPacket(requestPacket)
+}
+
+/*
+ * Retreive Acknowledgement
+ * Wait for the offer for a specific Request Packet.
+ */
+func (c *Client) GetAcknowledgement(requestPacket *dhcp4.Packet) (dhcp4.Packet, error) {
+ for {
+ c.connection.SetReadTimeout(c.timeout)
+ readBuffer, source, err := c.connection.ReadFrom()
+ if err != nil {
+ return dhcp4.Packet{}, err
+ }
+
+ acknowledgementPacket := dhcp4.Packet(readBuffer)
+ acknowledgementPacketOptions := acknowledgementPacket.ParseOptions()
+
+ // Ignore Servers in my Ignore list
+ for _, ignoreServer := range c.ignoreServers {
+ if source.Equal(ignoreServer) {
+ continue
+ }
+
+ if acknowledgementPacket.SIAddr().Equal(ignoreServer) {
+ continue
+ }
+ }
+
+ if !bytes.Equal(requestPacket.XId(), acknowledgementPacket.XId()) || len(acknowledgementPacketOptions[dhcp4.OptionDHCPMessageType]) < 1 || (dhcp4.MessageType(acknowledgementPacketOptions[dhcp4.OptionDHCPMessageType][0]) != dhcp4.ACK && dhcp4.MessageType(acknowledgementPacketOptions[dhcp4.OptionDHCPMessageType][0]) != dhcp4.NAK) {
+ continue
+ }
+
+ return acknowledgementPacket, nil
+ }
+}
+
+/*
+ * Send a DHCP Packet.
+ */
+func (c *Client) SendPacket(packet dhcp4.Packet) error {
+ return c.connection.Write(packet)
+}
+
+/*
+ * Create Discover Packet
+ */
+func (c *Client) DiscoverPacket() dhcp4.Packet {
+ messageid := make([]byte, 4)
+ if _, err := rand.Read(messageid); err != nil {
+ panic(err)
+ }
+
+ packet := dhcp4.NewPacket(dhcp4.BootRequest)
+ packet.SetCHAddr(c.hardwareAddr)
+ packet.SetXId(messageid)
+ packet.SetBroadcast(c.broadcast)
+
+ packet.AddOption(dhcp4.OptionDHCPMessageType, []byte{byte(dhcp4.Discover)})
+ //packet.PadToMinSize()
+ return packet
+}
+
+/*
+ * Create Request Packet
+ */
+func (c *Client) RequestPacket(offerPacket *dhcp4.Packet) dhcp4.Packet {
+ offerOptions := offerPacket.ParseOptions()
+
+ packet := dhcp4.NewPacket(dhcp4.BootRequest)
+ packet.SetCHAddr(c.hardwareAddr)
+
+ packet.SetXId(offerPacket.XId())
+ packet.SetCIAddr(offerPacket.CIAddr())
+ packet.SetSIAddr(offerPacket.SIAddr())
+
+ packet.SetBroadcast(c.broadcast)
+ packet.AddOption(dhcp4.OptionDHCPMessageType, []byte{byte(dhcp4.Request)})
+ packet.AddOption(dhcp4.OptionRequestedIPAddress, (offerPacket.YIAddr()).To4())
+ packet.AddOption(dhcp4.OptionServerIdentifier, offerOptions[dhcp4.OptionServerIdentifier])
+
+ //packet.PadToMinSize()
+ return packet
+}
+
+/*
+ * Create Request Packet For a Renew
+ */
+func (c *Client) RenewalRequestPacket(acknowledgement *dhcp4.Packet) dhcp4.Packet {
+ messageid := make([]byte, 4)
+ if _, err := rand.Read(messageid); err != nil {
+ panic(err)
+ }
+
+ acknowledgementOptions := acknowledgement.ParseOptions()
+
+ packet := dhcp4.NewPacket(dhcp4.BootRequest)
+ packet.SetCHAddr(acknowledgement.CHAddr())
+
+ packet.SetXId(messageid)
+ packet.SetCIAddr(acknowledgement.YIAddr())
+ packet.SetSIAddr(acknowledgement.SIAddr())
+
+ packet.SetBroadcast(c.broadcast)
+ packet.AddOption(dhcp4.OptionDHCPMessageType, []byte{byte(dhcp4.Request)})
+ packet.AddOption(dhcp4.OptionRequestedIPAddress, (acknowledgement.YIAddr()).To4())
+ packet.AddOption(dhcp4.OptionServerIdentifier, acknowledgementOptions[dhcp4.OptionServerIdentifier])
+
+ //packet.PadToMinSize()
+ return packet
+}
+
+/*
+ * Create Release Packet For a Release
+ */
+func (c *Client) ReleasePacket(acknowledgement *dhcp4.Packet) dhcp4.Packet {
+ messageid := make([]byte, 4)
+ if _, err := rand.Read(messageid); err != nil {
+ panic(err)
+ }
+
+ acknowledgementOptions := acknowledgement.ParseOptions()
+
+ packet := dhcp4.NewPacket(dhcp4.BootRequest)
+ packet.SetCHAddr(acknowledgement.CHAddr())
+
+ packet.SetXId(messageid)
+ packet.SetCIAddr(acknowledgement.YIAddr())
+
+ packet.AddOption(dhcp4.OptionDHCPMessageType, []byte{byte(dhcp4.Release)})
+ packet.AddOption(dhcp4.OptionServerIdentifier, acknowledgementOptions[dhcp4.OptionServerIdentifier])
+
+ //packet.PadToMinSize()
+ return packet
+}
+
+/*
+ * Lets do a Full DHCP Request.
+ */
+func (c *Client) Request() (bool, dhcp4.Packet, error) {
+ discoveryPacket, err := c.SendDiscoverPacket()
+ if err != nil {
+ return false, discoveryPacket, err
+ }
+
+ offerPacket, err := c.GetOffer(&discoveryPacket)
+ if err != nil {
+ return false, offerPacket, err
+ }
+
+ requestPacket, err := c.SendRequest(&offerPacket)
+ if err != nil {
+ return false, requestPacket, err
+ }
+
+ acknowledgement, err := c.GetAcknowledgement(&requestPacket)
+ if err != nil {
+ return false, acknowledgement, err
+ }
+
+ acknowledgementOptions := acknowledgement.ParseOptions()
+ if dhcp4.MessageType(acknowledgementOptions[dhcp4.OptionDHCPMessageType][0]) != dhcp4.ACK {
+ return false, acknowledgement, nil
+ }
+
+ return true, acknowledgement, nil
+}
+
+/*
+ * Renew a lease backed on the Acknowledgement Packet.
+ * Returns Sucessfull, The AcknoledgementPacket, Any Errors
+ */
+func (c *Client) Renew(acknowledgement dhcp4.Packet) (bool, dhcp4.Packet, error) {
+ renewRequest := c.RenewalRequestPacket(&acknowledgement)
+ renewRequest.PadToMinSize()
+
+ err := c.SendPacket(renewRequest)
+ if err != nil {
+ return false, renewRequest, err
+ }
+
+ newAcknowledgement, err := c.GetAcknowledgement(&renewRequest)
+ if err != nil {
+ return false, newAcknowledgement, err
+ }
+
+ newAcknowledgementOptions := newAcknowledgement.ParseOptions()
+ if dhcp4.MessageType(newAcknowledgementOptions[dhcp4.OptionDHCPMessageType][0]) != dhcp4.ACK {
+ return false, newAcknowledgement, nil
+ }
+
+ return true, newAcknowledgement, nil
+}
+
+/*
+ * Release a lease backed on the Acknowledgement Packet.
+ * Returns Any Errors
+ */
+func (c *Client) Release(acknowledgement dhcp4.Packet) error {
+ release := c.ReleasePacket(&acknowledgement)
+ release.PadToMinSize()
+
+ return c.SendPacket(release)
+}
--- /dev/null
+package dhcp4client
+
+import (
+ "net"
+ "time"
+)
+
+type inetSock struct {
+ *net.UDPConn
+
+ laddr net.UDPAddr
+ raddr net.UDPAddr
+}
+
+func NewInetSock(options ...func(*inetSock) error) (*inetSock, error) {
+ c := &inetSock{
+ laddr: net.UDPAddr{IP: net.IPv4(0, 0, 0, 0), Port: 68},
+ raddr: net.UDPAddr{IP: net.IPv4bcast, Port: 67},
+ }
+
+ err := c.setOption(options...)
+ if err != nil {
+ return nil, err
+ }
+
+ conn, err := net.ListenUDP("udp4", &c.laddr)
+ if err != nil {
+ return nil, err
+ }
+
+ c.UDPConn = conn
+ return c, err
+}
+
+func (c *inetSock) setOption(options ...func(*inetSock) error) error {
+ for _, opt := range options {
+ if err := opt(c); err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+func SetLocalAddr(l net.UDPAddr) func(*inetSock) error {
+ return func(c *inetSock) error {
+ c.laddr = l
+ return nil
+ }
+}
+
+func SetRemoteAddr(r net.UDPAddr) func(*inetSock) error {
+ return func(c *inetSock) error {
+ c.raddr = r
+ return nil
+ }
+}
+
+func (c *inetSock) Write(packet []byte) error {
+ _, err := c.WriteToUDP(packet, &c.raddr)
+ return err
+}
+
+func (c *inetSock) ReadFrom() ([]byte, net.IP, error) {
+ readBuffer := make([]byte, MaxDHCPLen)
+ n, source, err := c.ReadFromUDP(readBuffer)
+ if source != nil {
+ return readBuffer[:n], source.IP, err
+ } else {
+ return readBuffer[:n], net.IP{}, err
+ }
+}
+
+func (c *inetSock) SetReadTimeout(t time.Duration) error {
+ return c.SetReadDeadline(time.Now().Add(t))
+}
--- /dev/null
+package dhcp4client
+
+import (
+ "math/rand"
+ "time"
+)
+
+func init() {
+ rand.Seed(time.Now().Unix())
+}
--- /dev/null
+package dhcp4client
+
+import (
+ "crypto/rand"
+ "encoding/binary"
+ "net"
+ "time"
+
+ "golang.org/x/sys/unix"
+)
+
+const (
+ minIPHdrLen = 20
+ maxIPHdrLen = 60
+ udpHdrLen = 8
+ ip4Ver = 0x40
+ ttl = 16
+ srcPort = 68
+ dstPort = 67
+)
+
+var (
+ bcastMAC = []byte{255, 255, 255, 255, 255, 255}
+)
+
+// abstracts AF_PACKET
+type packetSock struct {
+ fd int
+ ifindex int
+}
+
+func NewPacketSock(ifindex int) (*packetSock, error) {
+ fd, err := unix.Socket(unix.AF_PACKET, unix.SOCK_DGRAM, int(swap16(unix.ETH_P_IP)))
+ if err != nil {
+ return nil, err
+ }
+
+ addr := unix.SockaddrLinklayer{
+ Ifindex: ifindex,
+ Protocol: swap16(unix.ETH_P_IP),
+ }
+
+ if err = unix.Bind(fd, &addr); err != nil {
+ return nil, err
+ }
+
+ return &packetSock{
+ fd: fd,
+ ifindex: ifindex,
+ }, nil
+}
+
+func (pc *packetSock) Close() error {
+ return unix.Close(pc.fd)
+}
+
+func (pc *packetSock) Write(packet []byte) error {
+ lladdr := unix.SockaddrLinklayer{
+ Ifindex: pc.ifindex,
+ Protocol: swap16(unix.ETH_P_IP),
+ Halen: uint8(len(bcastMAC)),
+ }
+ copy(lladdr.Addr[:], bcastMAC)
+
+ pkt := make([]byte, minIPHdrLen+udpHdrLen+len(packet))
+
+ fillIPHdr(pkt[0:minIPHdrLen], udpHdrLen+uint16(len(packet)))
+ fillUDPHdr(pkt[minIPHdrLen:minIPHdrLen+udpHdrLen], uint16(len(packet)))
+
+ // payload
+ copy(pkt[minIPHdrLen+udpHdrLen:len(pkt)], packet)
+
+ return unix.Sendto(pc.fd, pkt, 0, &lladdr)
+}
+
+func (pc *packetSock) ReadFrom() ([]byte, net.IP, error) {
+ pkt := make([]byte, maxIPHdrLen+udpHdrLen+MaxDHCPLen)
+ n, _, err := unix.Recvfrom(pc.fd, pkt, 0)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ // IP hdr len
+ ihl := int(pkt[0]&0x0F) * 4
+ // Source IP address
+ src := net.IP(pkt[12:16])
+
+ return pkt[ihl+udpHdrLen : n], src, nil
+}
+
+func (pc *packetSock) SetReadTimeout(t time.Duration) error {
+
+ tv := unix.NsecToTimeval(t.Nanoseconds())
+ return unix.SetsockoptTimeval(pc.fd, unix.SOL_SOCKET, unix.SO_RCVTIMEO, &tv)
+}
+
+// compute's 1's complement checksum
+func chksum(p []byte, csum []byte) {
+ cklen := len(p)
+ s := uint32(0)
+ for i := 0; i < (cklen - 1); i += 2 {
+ s += uint32(p[i+1])<<8 | uint32(p[i])
+ }
+ if cklen&1 == 1 {
+ s += uint32(p[cklen-1])
+ }
+ s = (s >> 16) + (s & 0xffff)
+ s = s + (s >> 16)
+ s = ^s
+
+ csum[0] = uint8(s & 0xff)
+ csum[1] = uint8(s >> 8)
+}
+
+func fillIPHdr(hdr []byte, payloadLen uint16) {
+ // version + IHL
+ hdr[0] = ip4Ver | (minIPHdrLen / 4)
+ // total length
+ binary.BigEndian.PutUint16(hdr[2:4], uint16(len(hdr))+payloadLen)
+ // identification
+ if _, err := rand.Read(hdr[4:5]); err != nil {
+ panic(err)
+ }
+ // TTL
+ hdr[8] = 16
+ // Protocol
+ hdr[9] = unix.IPPROTO_UDP
+ // dst IP
+ copy(hdr[16:20], net.IPv4bcast.To4())
+ // compute IP hdr checksum
+ chksum(hdr[0:len(hdr)], hdr[10:12])
+}
+
+func fillUDPHdr(hdr []byte, payloadLen uint16) {
+ // src port
+ binary.BigEndian.PutUint16(hdr[0:2], srcPort)
+ // dest port
+ binary.BigEndian.PutUint16(hdr[2:4], dstPort)
+ // length
+ binary.BigEndian.PutUint16(hdr[4:6], udpHdrLen+payloadLen)
+}
+
+func swap16(x uint16) uint16 {
+ var b [2]byte
+ binary.BigEndian.PutUint16(b[:], x)
+ return binary.LittleEndian.Uint16(b[:])
+}
git://git.halfball.org / plugins.git / commitdiff