packet

type ArpPacket ¶

type ArpPacket struct {
	HardwareType   uint16
	ProtocolType   uint16
	HardwareLen    uint8
	IPLen          uint8
	Operation      uint16
	SendHardware   HardwareAddr
	SendIP         IPv4
	TargetHardware HardwareAddr
	TargetIP       IPv4
}

    Ethernet transmission layer (not necessarily accessible to the user):
    // 14.byte  EthernetPacket
	2.byte  16.bit: (ar$hrd) Hardware address space (e.g., Ethernet, Packet Radio Net.)
	2.byte  16.bit: (ar$pro) Protocol address space.  For Ethernet hardware, this is from the set of type fields ether_typ$<protocol>.
	1.byte   8.bit: (ar$hln) byte length of each hardware address
	1.byte   8.bit: (ar$pln) byte length of each protocol address
	2.byte  16.bit: (ar$op)  opcode (ares_op$REQUEST | ares_op$REPLY)
	        nbytes: (ar$sha) Hardware address of sender of this packet, n from the ar$hln field.
	        mbytes: (ar$spa) Protocol address of sender of this packet, m from the ar$pln field.
	        nbytes: (ar$tha) Hardware address of target of this packet (if known).
	        mbytes: (ar$tpa) Protocol address of target.

func NewArpPacket(b [SizeofArpPacket]byte) (arp ArpPacket)

func (arp ArpPacket) String() string

func (arp ArpPacket) WireFormat() []byte

type DHCP_IPv4_TYPE ¶

type DHCP_IPv4_TYPE uint8

3.3. Subnet Mask

The subnet mask option specifies the client's subnet mask as per RFC
950 [5].

If both the subnet mask and the router option are specified in a DHCP
reply, the subnet mask option MUST be first.
The code for the subnet mask option is 1, and its length is 4 octets.

Code   Len        Subnet Mask
+-----+-----+-----+-----+-----+-----+
|  1  |  4  |  m1 |  m2 |  m3 |  m4 |
+-----+-----+-----+-----+-----+-----+

3.5. Router Option

The router option specifies a list of IP addresses for routers on the
client's subnet.  Routers SHOULD be listed in order of preference.

The code for the router option is 3.  The minimum length for the
router option is 4 octets, and the length MUST always be a multiple
of 4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  3  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

3.6. Time Server Option

The time server option specifies a list of RFC 868 [6] time servers
available to the client.  Servers SHOULD be listed in order of
preference.

The code for the time server option is 4.  The minimum length for
this option is 4 octets, and the length MUST always be a multiple of
4.
Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  4  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

3.7. Name Server Option

The name server option specifies a list of IEN 116 [7] name servers
available to the client.  Servers SHOULD be listed in order of
preference.

The code for the name server option is 5.  The minimum length for
this option is 4 octets, and the length MUST always be a multiple of
4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  5  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

3.8. Domain Name Server Option

The domain name server option specifies a list of Domain Name System
(STD 13, RFC 1035 [8]) name servers available to the client.  Servers
SHOULD be listed in order of preference.

The code for the domain name server option is 6.  The minimum length
for this option is 4 octets, and the length MUST always be a multiple
of 4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  6  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

3.9. Log Server Option

The log server option specifies a list of MIT-LCS UDP log servers
available to the client.  Servers SHOULD be listed in order of
preference.

The code for the log server option is 7.  The minimum length for this
option is 4 octets, and the length MUST always be a multiple of 4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  7  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

3.10. Cookie Server Option

The cookie server option specifies a list of RFC 865 [9] cookie
servers available to the client.  Servers SHOULD be listed in order
of preference.

The code for the log server option is 8.  The minimum length for this
option is 4 octets, and the length MUST always be a multiple of 4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  8  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

3.11. LPR Server Option

The LPR server option specifies a list of RFC 1179 [10] line printer
servers available to the client.  Servers SHOULD be listed in order
of preference.

The code for the LPR server option is 9.  The minimum length for this
option is 4 octets, and the length MUST always be a multiple of 4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  9  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

3.12. Impress Server Option

The Impress server option specifies a list of Imagen Impress servers
available to the client.  Servers SHOULD be listed in order of
preference.

The code for the Impress server option is 10.  The minimum length for
this option is 4 octets, and the length MUST always be a multiple of
4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  10 |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

3.13. Resource Location Server Option

This option specifies a list of RFC 887 [11] Resource Location
servers available to the client.  Servers SHOULD be listed in order
of preference.

The code for this option is 11.  The minimum length for this option
is 4 octets, and the length MUST always be a multiple of 4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  11 |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

8.2. Network Information Servers Option

This option specifies a list of IP addresses indicating NIS servers
available to the client.  Servers SHOULD be listed in order of
preference.

The code for this option is 41.  Its minimum length is 4, and the
length MUST be a multiple of 4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  41 |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

8.3. Network Time Protocol Servers Option

This option specifies a list of IP addresses indicating NTP [18]
servers available to the client.  Servers SHOULD be listed in order
of preference.

The code for this option is 42.  Its minimum length is 4, and the
length MUST be a multiple of 4.
Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  42 |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

8.5. NetBIOS over TCP/IP Name Server Option

The NetBIOS name server (NBNS) option specifies a list of RFC
1001/1002 [19] [20] NBNS name servers listed in order of preference.

The code for this option is 44.  The minimum length of the option is
4 octets, and the length must always be a multiple of 4.

Code   Len           Address 1              Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----
|  44 |  n  |  a1 |  a2 |  a3 |  a4 |  b1 |  b2 |  b3 |  b4 | ...
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----

8.6. NetBIOS over TCP/IP Datagram Distribution Server Option

The NetBIOS datagram distribution server (NBDD) option specifies a
list of RFC 1001/1002 NBDD servers listed in order of preference. The
code for this option is 45.  The minimum length of the option is 4
octets, and the length must always be a multiple of 4.

Code   Len           Address 1              Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----
|  45 |  n  |  a1 |  a2 |  a3 |  a4 |  b1 |  b2 |  b3 |  b4 | ...
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+----

8.9. X Window System Font Server Option

This option specifies a list of X Window System [21] Font servers
available to the client. Servers SHOULD be listed in order of
preference.

The code for this option is 48.  The minimum length of this option is
4 octets, and the length MUST be a multiple of 4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+---
|  48 |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |   ...
+-----+-----+-----+-----+-----+-----+-----+-----+---

8.10. X Window System Display Manager Option

This option specifies a list of IP addresses of systems that are
running the X Window System Display Manager and are available to the
client.

Addresses SHOULD be listed in order of preference.
The code for the this option is 49. The minimum length of this option
is 4, and the length MUST be a multiple of 4.

Code   Len         Address 1               Address 2

+-----+-----+-----+-----+-----+-----+-----+-----+---
|  49 |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |   ...
+-----+-----+-----+-----+-----+-----+-----+-----+---

8.12. Network Information Service+ Servers Option

This option specifies a list of IP addresses indicating NIS+ servers
available to the client.  Servers SHOULD be listed in order of
preference.

The code for this option is 65.  Its minimum length is 4, and the
length MUST be a multiple of 4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
|  65 |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

8.13. Mobile IP Home Agent option

This option specifies a list of IP addresses indicating mobile IP
home agents available to the client.  Agents SHOULD be listed in
order of preference.

The code for this option is 68.  Its minimum length is 0 (indicating
no home agents are available) and the length MUST be a multiple of 4.
It is expected that the usual length will be four octets, containing
a single home agent's address.

Code Len    Home Agent Addresses (zero or more)
+-----+-----+-----+-----+-----+-----+--
| 68  |  n  | a1  | a2  | a3  | a4  | ...
+-----+-----+-----+-----+-----+-----+--

8.14. Simple Mail Transport Protocol (SMTP) Server Option

The SMTP server option specifies a list of SMTP servers available to
the client.  Servers SHOULD be listed in order of preference.

The code for the SMTP server option is 69.  The minimum length for
this option is 4 octets, and the length MUST always be a multiple of
4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
| 69  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

8.15. Post Office Protocol (POP3) Server Option

The POP3 server option specifies a list of POP3 available to the
client.  Servers SHOULD be listed in order of preference.

The code for the POP3 server option is 70.  The minimum length for
this option is 4 octets, and the length MUST always be a multiple of
4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
| 70  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

8.16. Network News Transport Protocol (NNTP) Server Option

The NNTP server option specifies a list of NNTP available to the
client.  Servers SHOULD be listed in order of preference.

The code for the NNTP server option is 71. The minimum length for
this option is 4 octets, and the length MUST always be a multiple of
4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
| 71  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

8.17. Default World Wide Web (WWW) Server Option

The WWW server option specifies a list of WWW available to the
client.  Servers SHOULD be listed in order of preference.

The code for the WWW server option is 72.  The minimum length for
this option is 4 octets, and the length MUST always be a multiple of
4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
| 72  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

8.18. Default Finger Server Option

The Finger server option specifies a list of Finger available to the
client.  Servers SHOULD be listed in order of preference.

The code for the Finger server option is 73.  The minimum length for
this option is 4 octets, and the length MUST always be a multiple of
4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
| 73  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

8.19. Default Internet Relay Chat (IRC) Server Option

The IRC server option specifies a list of IRC available to the
client.  Servers SHOULD be listed in order of preference.

The code for the IRC server option is 74.  The minimum length for
this option is 4 octets, and the length MUST always be a multiple of
4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
| 74  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

8.20. StreetTalk Server Option

The StreetTalk server option specifies a list of StreetTalk servers
available to the client.  Servers SHOULD be listed in order of
preference.

The code for the StreetTalk server option is 75.  The minimum length
for this option is 4 octets, and the length MUST always be a multiple
of 4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
| 75  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

8.21. StreetTalk Directory Assistance (STDA) Server Option

The StreetTalk Directory Assistance (STDA) server option specifies a
list of STDA servers available to the client.  Servers SHOULD be
listed in order of preference.

The code for the StreetTalk Directory Assistance server option is 76.
The minimum length for this option is 4 octets, and the length MUST
always be a multiple of 4.

Code   Len         Address 1               Address 2
+-----+-----+-----+-----+-----+-----+-----+-----+--
| 76  |  n  |  a1 |  a2 |  a3 |  a4 |  a1 |  a2 |  ...
+-----+-----+-----+-----+-----+-----+-----+-----+--

9.1. Requested IP Address

This option is used in a client request (DHCPDISCOVER) to allow the
client to request that a particular IP address be assigned.

The code for this option is 50, and its length is 4.

Code   Len          Address
+-----+-----+-----+-----+-----+-----+
|  50 |  4  |  a1 |  a2 |  a3 |  a4 |
+-----+-----+-----+-----+-----+-----+

9.7. Server Identifier

This option is used in DHCPOFFER and DHCPREQUEST messages, and may
optionally be included in the DHCPACK and DHCPNAK messages.  DHCP
servers include this option in the DHCPOFFER in order to allow the
client to distinguish between lease offers.  DHCP clients use the
contents of the 'server identifier' field as the destination address
for any DHCP messages unicast to the DHCP server.  DHCP clients also
indicate which of several lease offers is being accepted by including
this option in a DHCPREQUEST message.

The identifier is the IP address of the selected server.

The code for this option is 54, and its length is 4.

Code   Len            Address
+-----+-----+-----+-----+-----+-----+
|  54 |  4  |  a1 |  a2 |  a3 |  a4 |
+-----+-----+-----+-----+-----+-----+

const (
	DHCP_Subnet_Mask DHCP_IPv4_TYPE = iota + 1

	DHCP_Router
	DHCP_Time_Server
	DHCP_Name_Server
	DHCP_Domain_Name_Server
	DHCP_Log_Server
	DHCP_Cookie_Server
	DHCP_LPR_Server
	DHCP_Impress_Server
	DHCP_Resource_Location_Server
)

const (
	DHCP_Information_Servers DHCP_IPv4_TYPE = iota + 41
	DHCP_Protocol_Servers

	DHCP_NetBIOS_Name_Server
	DHCP_NetBIOS_Distribution_Server

	DHCP_Window_System_Server
	DHCP_Window_System_Display_Manager
	DHCP_Requested_IP_Address

	DHCP_Server_Identifier
)

const (
	DHCP_Network_Information_Service_Servers DHCP_IPv4_TYPE = iota + 65

	DHCP_Mobile_IP_Home_Agent
	DHCP_SMTP_Server
	DHCP_POP3_Server
	DHCP_NNTP_Server
	DHCP_WWW_Server
	DHCP_Default_Finger_Server
	DHCP_IRC_Server
	DHCP_StreetTalk_Server
	DHCP_STDA_Server
)

type DHCP_Message_Type ¶

type DHCP_Message_Type uint8

9.6. DHCP Message Type

This option is used to convey the type of the DHCP message.  The code
for this option is 53, and its length is 1.  Legal values for this
option are:

       Value   Message Type
       -----   ------------
         1     DHCPDISCOVER
         2     DHCPOFFER
         3     DHCPREQUEST
         4     DHCPDECLINE
         5     DHCPACK
         6     DHCPNAK
         7     DHCPRELEASE
         8     DHCPINFORM

const (
	DHCP_DISCOVER DHCP_Message_Type = iota + 1
	DHCP_OFFER
	DHCP_REQUEST
	DHCP_DECLINE
	DHCP_ACK
	DHCP_NAK
	DHCP_RELEASE
	DHCP_INFORM
)

type DHCP_NetBIOS_Node_Type ¶

type DHCP_NetBIOS_Node_Type uint8

8.7. NetBIOS over TCP/IP Node Type Option

The NetBIOS node type option allows NetBIOS over TCP/IP clients which
are configurable to be configured as described in RFC 1001/1002.  The
value is specified as a single octet which identifies the client type
as follows:

Value         Node Type
-----         ---------
0x1           B-node
0x2           P-node
0x4           M-node
0x8           H-node

const (
	DHCP_B_node DHCP_NetBIOS_Node_Type = iota + 1
	DHCP_P_node

	DHCP_M_node

	DHCP_H_node
)

type DHCP_STRING_TYPE ¶

type DHCP_STRING_TYPE uint8

8.1. Network Information Service Domain Option

This option specifies the name of the client's NIS [17] domain.  The
domain is formatted as a character string consisting of characters
from the NVT ASCII character set.

The code for this option is 40.  Its minimum length is 1.

Code   Len      NIS Domain Name
+-----+-----+-----+-----+-----+-----+---
|  40 |  n  |  n1 |  n2 |  n3 |  n4 | ...
+-----+-----+-----+-----+-----+-----+---

8.8. NetBIOS over TCP/IP Scope Option

The NetBIOS scope option specifies the NetBIOS over TCP/IP scope
parameter for the client as specified in RFC 1001/1002. See [19],
[20], and [8] for character-set restrictions.

The code for this option is 47.  The minimum length of this option is
1.

Code   Len       NetBIOS Scope
+-----+-----+-----+-----+-----+-----+----
|  47 |  n  |  s1 |  s2 |  s3 |  s4 | ...
+-----+-----+-----+-----+-----+-----+----

8.11. Network Information Service+ Domain Option

This option specifies the name of the client's NIS+ [17] domain.  The
domain is formatted as a character string consisting of characters
from the NVT ASCII character set.

The code for this option is 64.  Its minimum length is 1.

Code   Len      NIS Client Domain Name
+-----+-----+-----+-----+-----+-----+---
|  64 |  n  |  n1 |  n2 |  n3 |  n4 | ...
+-----+-----+-----+-----+-----+-----+---

9.4 TFTP server name

This option is used to identify a TFTP server when the 'sname' field
in the DHCP header has been used for DHCP options.

The code for this option is 66, and its minimum length is 1.

Code  Len   TFTP server
+-----+-----+-----+-----+-----+---
| 66  |  n  |  c1 |  c2 |  c3 | ...
+-----+-----+-----+-----+-----+---

9.5 Bootfile name

This option is used to identify a bootfile when the 'file' field in
the DHCP header has been used for DHCP options.

The code for this option is 67, and its minimum length is 1.

   Code  Len   Bootfile name
  +-----+-----+-----+-----+-----+---
  | 67  |  n  |  c1 |  c2 |  c3 | ...
  +-----+-----+-----+-----+-----+---

9.9. Message

This option is used by a DHCP server to provide an error message to a
DHCP client in a DHCPNAK message in the event of a failure. A client
may use this option in a DHCPDECLINE message to indicate the why the
client declined the offered parameters.  The message consists of n
octets of NVT ASCII text, which the client may display on an
available output device.

The code for this option is 56 and its minimum length is 1.

Code   Len     Text
+-----+-----+-----+-----+---
|  56 |  n  |  c1 |  c2 | ...
+-----+-----+-----+-----+---

9.13. Vendor class identifier

This option is used by DHCP clients to optionally identify the vendor
type and configuration of a DHCP client.  The information is a string
of n octets, interpreted by servers.  Vendors may choose to define
specific vendor class identifiers to convey particular configuration
or other identification information about a client.  For example, the
identifier may encode the client's hardware configuration.  Servers
not equipped to interpret the class-specific information sent by a
client MUST ignore it (although it may be reported). Servers that
respond SHOULD only use option 43 to return the vendor-specific
information to the client.

The code for this option is 60, and its minimum length is 1.

Code   Len   Vendor class Identifier
+-----+-----+-----+-----+---
|  60 |  n  |  i1 |  i2 | ...
+-----+-----+-----+-----+---

const (
	DHCP_Network_Information_Service_Domain  DHCP_STRING_TYPE = 40
	DHCP_NetBIOS_Scope                       DHCP_STRING_TYPE = 47
	DHCP_Network_Information_ServiceS_Domain DHCP_STRING_TYPE = 64
	DHCP_TFTP_Server_Name                    DHCP_STRING_TYPE = 66
	DHCP_Bootfile_Name                       DHCP_STRING_TYPE = 67
	DHCP_Error_Message                       DHCP_STRING_TYPE = 56
	DHCP_Vendor_Class_Identifier             DHCP_STRING_TYPE = 60
)

type DHCP_TIME_TYPE ¶

type DHCP_TIME_TYPE uint8

9.2. IP Address Lease Time

This option is used in a client request (DHCPDISCOVER or DHCPREQUEST)
to allow the client to request a lease time for the IP address.  In a
server reply (DHCPOFFER), a DHCP server uses this option to specify
the lease time it is willing to offer.

The time is in units of seconds, and is specified as a 32-bit
unsigned integer.

The code for this option is 51, and its length is 4.

Code   Len         Lease Time
+-----+-----+-----+-----+-----+-----+
|  51 |  4  |  t1 |  t2 |  t3 |  t4 |
+-----+-----+-----+-----+-----+-----+

9.11. Renewal (T1) Time Value

This option specifies the time interval from address assignment until
the client transitions to the RENEWING state.

The value is in units of seconds, and is specified as a 32-bit
unsigned integer.

The code for this option is 58, and its length is 4.

Code   Len         T1 Interval
+-----+-----+-----+-----+-----+-----+
|  58 |  4  |  t1 |  t2 |  t3 |  t4 |
+-----+-----+-----+-----+-----+-----+

9.12. Rebinding (T2) Time Value

This option specifies the time interval from address assignment until
the client transitions to the REBINDING state.

The value is in units of seconds, and is specified as a 32-bit
unsigned integer.

The code for this option is 59, and its length is 4.

Code   Len         T2 Interval
+-----+-----+-----+-----+-----+-----+
|  59 |  4  |  t1 |  t2 |  t3 |  t4 |
+-----+-----+-----+-----+-----+-----+

const (
	DHCP_Renewal_Time DHCP_TIME_TYPE = iota + 58
	DHCP_Rebinding_Time
	DHCP_IP_Address_Lease DHCP_TIME_TYPE = 51
)

type DUPPacket ¶ added in v0.1.0

type DUPPacket struct {
	SrcPort  uint16
	DstPort  uint16
	Len      uint16
	CheckSum uint16
}

func NewDUPPacket(b [SizeofDUPPacket]byte) (udp DUPPacket)

func (udp DUPPacket) WireFormat() []byte

type DhcpV4Packet ¶

type DhcpV4Packet struct {
	Op           uint8
	HardwareType uint8
	HardwareLen  uint8
	Hops         uint8
	XID          uint32
	Secs         uint16
	Flags        uint16
	CIAddr       IPv4
	YIAddr       IPv4
	SIAddr       IPv4
	GIAddr       IPv4
	ChHardware   [16]byte
	HostName     [64]byte
	FileName     [128]byte

	Options []OptionsPacket
	// contains filtered or unexported fields
}

// 14.byte EthernetPacket // 20.byte IPv4Packet

FIELD BYTES DESCRIPTION ----- ----- ----------- op 1 packet op code / message type. 1 = BOOTREQUEST, 2 = BOOTREPLY htype 1 hardware address type, see ARP section in "Assigned Numbers" RFC. '1' = 10mb ethernet hlen 1 hardware address length (eg '6' for 10mb ethernet). hops 1 client sets to zero, optionally used by gateways in cross-gateway booting. xid 4 transaction ID, a random number, used to match this boot request with the responses it generates. secs 2 filled in by client, seconds elapsed since client started trying to boot. -- 2 unused ciaddr 4 client IP address; filled in by client in bootrequest if known. yiaddr 4 'your' (client) IP address; filled by server if client doesn't know its own address (ciaddr was 0). siaddr 4 server IP address; returned in bootreply by server. giaddr 4 gateway IP address, used in optional cross-gateway booting. chaddr 16 client hardware address, filled in by client. sname 64 optional server host name, null terminated string. file 128 boot file name, null terminated string; 'generic' name or null in bootrequest, fully qualified directory-path name in bootreply. vend 64 optional vendor-specific area, e.g. could be hardware type/serial on request, or 'capability' / remote file system handle on reply. This info may be set aside for use by a third phase bootstrap or kernel.

func NewDhcpV4Packet(b []byte) (dhcp DhcpV4Packet)

func (dhcp DhcpV4Packet) WireFormat() []byte

type EthernetPacket ¶ added in v0.1.0

type EthernetPacket struct {
	HeadMAC   [2]HardwareAddr
	FrameType uint16
}

    Ethernet transmission layer (not necessarily accessible to the user):
	6.byte  48.bit: Ethernet address of destination
	6.byte  48.bit: Ethernet address of sender
	2.byte  16.bit: Protocol type = ether_type$ADDRESS_RESOLUTION Ethernet packet data:
	// N.byte packet

func NewEthernetPacket(b [SizeofEthernetPacket]byte) (eth EthernetPacket)

func (eth EthernetPacket) WireFormat() []byte

type HardwareAddr ¶

type HardwareAddr [6]byte

func (h HardwareAddr) String() string

type IPv4 ¶

type IPv4 [4]byte

func (v4 IPv4) String() string

type IPv4Packet ¶ added in v0.1.0

type IPv4Packet struct {
	Version  uint8
	TOS      uint8
	TotalLen uint16
	ID       uint16
	FragOff  uint16
	TTL      uint8
	Protocol uint8
	Checksum uint16
	Src      IPv4
	Dst      IPv4

	Flags   uint8
	IHL     uint8
	Options []byte
}

// 14.byte EthernetPacket

3.1. Internet Header Format

	A summary of the contents of the internet header follows:
    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Version|  IHL  |Type of Service|          Total Length         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |         Identification        |Flags|      Fragment Offset    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Time to Live |    Protocol   |         Header Checksum       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Source Address                          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Destination Address                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Options                    |    Padding    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                    Example Internet Datagram Header

                               Figure 4.

  Note that each tick mark represents one bit position.

  Version:  		4 bits
  IHL:  			4 bits
  Type of Service:  8 bits
  		its 0-2:  Precedence.
  		Bit    3:  0 = Normal Delay,      1 = Low Delay.
  		Bits   4:  0 = Normal Throughput, 1 = High Throughput.
  		Bits   5:  0 = Normal Relibility, 1 = High Relibility.
  		Bit  6-7:  Reserved for Future Use.

  Total Length:  	16 bits
  Identification:  	16 bits
  Flags:  			3 bits
  Fragment Offset:  13 bits
  Time to Live:  	8 bits
  Protocol:  		8 bits
  Header Checksum:  16 bits
  Source Address:  	32 bits
  Destination Address:  32 bits

func NewIPv4Packet(b []byte) (ipv4 IPv4Packet, next uint8)

func (ipv4 IPv4Packet) String() string

func (ipv4 IPv4Packet) WireFormat() []byte

type IfAddrmsg ¶

type IfAddrmsg syscall.IfAddrmsg

func NewIfAddrmsg(b [SizeofIfAddrmsg]byte) (addr *IfAddrmsg)

func (addr *IfAddrmsg) WireFormat() []byte

type IfInfomsg ¶

type IfInfomsg syscall.IfInfomsg

func NewIfInfomsg(b [SizeofIfInfomsg]byte) (info *IfInfomsg)

func (info *IfInfomsg) WireFormat() []byte

type NlMsgerr ¶

type NlMsgerr struct {
	Error int32
	Msg   NlMsghdr
}

func NewNlMsgerr(b [SizeofNlMsgerr]byte) (nlmsg *NlMsgerr)

func (nlmsg *NlMsgerr) WireFormat() []byte

type NlMsghdr ¶

type NlMsghdr syscall.NlMsghdr

func NewNlMsghdr(b [SizeofNlMsghdr]byte) (hdr *NlMsghdr)

func (hdr *NlMsghdr) WireFormat() []byte

func (hdr *NlMsghdr) WireFormatToByte(b *[SizeofNlMsghdr]byte)

type OptionsPacket ¶

type OptionsPacket struct {
	Code   uint8
	Length uint8
	Value  []byte
}

func NewOptionsPacket(b []byte) (list []OptionsPacket)

func SetDHCPIPv4(t DHCP_IPv4_TYPE, ip ...IPv4) OptionsPacket

func SetDHCPMaximumMessageSize(size uint16) OptionsPacket

This option specifies the maximum length DHCP message that it is
willing to accept.  The length is specified as an unsigned 16-bit
integer.  A client may use the maximum DHCP message size option in
DHCPDISCOVER or DHCPREQUEST messages, but should not use the option
in DHCPDECLINE messages.

The code for this option is 57, and its length is 2.  The minimum
legal value is 576 octets.

Code   Len     Length
+-----+-----+-----+-----+
|  57 |  2  |  l1 |  l2 |
+-----+-----+-----+-----+

func SetDHCPMessage(t DHCP_Message_Type) OptionsPacket

func SetDHCPNetBIOSNodeType(t DHCP_NetBIOS_Node_Type) OptionsPacket

func SetDHCPOptionsRequestList(codes ...uint8) OptionsPacket

This option is used by a DHCP client to request values for specified
configuration parameters.  The list of requested parameters is
specified as n octets, where each octet is a valid DHCP option code
as defined in this document.

The client MAY list the options in order of preference.  The DHCP
server is not required to return the options in the requested order,
but MUST try to insert the requested options in the order requested
by the client.

The code for this option is 55.  Its minimum length is 1.

Code   Len   Option Codes
+-----+-----+-----+-----+---
|  55 |  n  |  c1 |  c2 | ...
+-----+-----+-----+-----+---

func SetDHCPString(t DHCP_STRING_TYPE, s string) OptionsPacket

func SetDHCPTime(t DHCP_TIME_TYPE, d time.Duration) OptionsPacket

func (opp OptionsPacket) WireFormat() []byte

type RtMsg ¶

type RtMsg syscall.RtMsg

func NewRtMsg(b [SizeofRtMsg]byte) (rtmsg *RtMsg)

func (rtmsg *RtMsg) WireFormat() []byte

type TCPPacket ¶ added in v0.1.0

type TCPPacket struct {
	SrcPort  uint16
	DstPort  uint16
	Sequence uint32
	AckNum   uint32

	Window    uint16
	CheckSum  uint16
	UrgentPtr uint16

	DataOffset uint8
	Reserved   uint8
	URG        bool
	ACK        bool
	PSH        bool
	RST        bool
	SYN        bool
	FIN        bool
	Options    []byte
	// contains filtered or unexported fields
}

// 来源： https://support.huawei.com/enterprise/zh/doc/EDOC1100174722?section=j006

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-------------------------------+-------------------------------+
   |          Source Port          |       Destination Port        |
   +-------------------------------+-------------------------------+
   |                        Sequence Number                        |
   +---------------------------------------------------------------+
   |                    Acknowledgment Number                      |
   +-------+-----------+-+-+-+-+-+-+-------------------------------+
   |  Data |           |U|A|P|R|S|F|                               |
   | Offset| Reserved  |R|C|S|S|Y|I|            Window             |
   |       |           |G|K|H|T|N|N|                               |
   +-------+-----------+-+-+-+-+-+-+-------------------------------+
   |           Checksum            |         Urgent Pointer        |
   +-------------------------------+---------------+---------------+
   |                    Options                    |    Padding    |
   +-----------------------------------------------+---------------+
   |                             data                              |
   +---------------------------------------------------------------+

	字段				长度		含义

Source Port 16比特 源端口，标识哪个应用程序发送。 Destination Port 16比特 目的端口，标识哪个应用程序接收。 Sequence Number 32比特 序号字段。TCP链接中传输的数据流中每个字节都编上一个序号。序号字段的值指的是本报文段所发送的数据的第一个字节的序号。 Acknowledgment Number 32比特 确认号，是期望收到对方的下一个报文段的数据的第1个字节的序号，即上次已成功接收到的数据字节序号加1。只有ACK标识为1，此字段有效。 Data Offset 4比特 数据偏移，即首部长度，指出TCP报文段的数据起始处距离TCP报文段的起始处有多远，以32比特（4字节）为计算单位。最多有60字节的首部，若无选项字段，正常为20字节。 Reserved 6比特 保留，必须填0。 URG 1比特 紧急指针有效标识。它告诉系统此报文段中有紧急数据，应尽快传送（相当于高优先级的数据）。 ACK 1比特 确认序号有效标识。只有当ACK=1时确认号字段才有效。当ACK=0时，确认号无效。 PSH 1比特 标识接收方应该尽快将这个报文段交给应用层。接收到PSH = 1的TCP报文段，应尽快的交付接收应用进程，而不再等待整个缓存都填满了后再向上交付。 RST 1比特 重建连接标识。当RST=1时，表明TCP连接中出现严重错误（如由于主机崩溃或其他原因），必须释放连接，然后再重新建立连接。 SYN 1比特 同步序号标识，用来发起一个连接。SYN=1表示这是一个连接请求或连接接受请求。 FIN 1比特 发端完成发送任务标识。用来释放一个连接。FIN=1表明此报文段的发送端的数据已经发送完毕，并要求释放连接。 Window 16比特 窗口：TCP的流量控制，窗口起始于确认序号字段指明的值，这个值是接收端期望接收的字节数。窗口最大为65535字节。 Checksum 16比特 校验字段，包括TCP首部和TCP数据，是一个强制性的字段，一定是由发端计算和存储，并由收端进行验证。在计算检验和时，要在TCP报文段的前面加上12字节的伪首部。 Urgent Pointer 16比特 紧急指针，只有当URG标志置1时紧急指针才有效。TCP的紧急方式是发送端向另一端发送紧急数据的一种方式。紧急指针指出在本报文段中紧急数据共有多少个字节（紧急数据放在本报文段数据的最前面）。 Options 可变 选项字段。TCP协议最初只规定了一种选项，即最长报文段长度（只包含数据字段，不包括TCP首部），又称为MSS。MSS告诉对方TCP“我的缓存所能接收的报文段的数据字段的最大长度是MSS个字节”。

新的RFC规定有以下几种选型：选项表结束，空操作，最大报文段长度，窗口扩大因子，时间戳。
	选项表结束。
	空操作：没有特殊含义，一般用于将TCP选项的总长度填充为4字节的整数倍。
	最大报文段长度：又称为MSS，只包含数据字段，不包括TCP首部。
	窗口扩大因子：3字节，其中一个字节表示偏移值S。新的窗口值等于TCP首部中的窗口位数增大到（16+S），相当于把窗口值向左移动S位后获得实际的窗口大小。
	时间戳：10字节，其中最主要的字段是时间戳值（4字节）和时间戳回送应答字段（4字节）。

Padding 可变 填充字段，用来补位，使整个首部长度是4字节的整数倍。

func NewTCPPacket(b []byte) (tcp TCPPacket, next uint8)

func (tcp TCPPacket) WireFormat() []byte