Namespace inet

DhcpMessage

class

Represents a DHCP message. DHCP (Dynamic Host Configuration Protocol, RFC 2131) provides a framework for passing configuration information to hosts on a TCP/IP network.

See also: DhcpClient, DhcpServer

Extends

Name	Type	Description
FieldsChunk	(unknown -- not in documented files)

Fields

Name	Type	Description
op	DhcpOpcode	message op code / message type. 1 = BOOTREQUEST, 2 = BOOTREPLY
htype	int	hardware address type, see Arp section in "Assigned Numbers" RFC; e.g., '1' = 10mb ethernet
hlen	int	hardware address length (e.g. '6' for 10mb ethernet)
hops	int	client sets to zero, optionally used by relay agents when booting via a relay agent
xid	unsigned int	transaction ID, a random number chosen by the client, used by the client and server to associate messages and responses between a client and a server
secs	int	filled in by client, seconds elapsed since client began address acquisition or renewal process
broadcast	bool	the broadcast bit in the flags field
reserved	uint16_t	MUST BE ZERO (reserved for future use)
ciaddr	Ipv4Address	client IP address; only filled in if client is in BOUND, RENEW or REBINDING state and can respond to Arp requests
yiaddr	Ipv4Address	'your' (client) IP address
giaddr	Ipv4Address	relay agent IP address, used in booting via a relay agent
chaddr	MacAddress	client hardware address (MAC)
sname	string	optional server host name
file	string	boot file name (unused in the simulation)
options	DhcpOptions	holds DHCP options

Packet operations (observed)

action	module
insertAtBack	DhcpClient, DhcpServer
peekAtFront	DhcpClient, DhcpServer

Source code

//
// Represents a DHCP message. DHCP (Dynamic Host Configuration Protocol, RFC 2131)
// provides a framework for passing configuration information to hosts on a TCP/IP network.
//
// @see DhcpClient, DhcpServer
//
class DhcpMessage extends FieldsChunk
{
    DhcpOpcode op; // message op code / message type. 1 = BOOTREQUEST, 2 = BOOTREPLY
    int htype; // hardware address type, see Arp section in "Assigned Numbers" RFC; e.g., '1' = 10mb ethernet
    int hlen; // hardware address length (e.g.  '6' for 10mb ethernet)
    int hops; // client sets to zero, optionally used by relay agents when booting via a relay agent
    unsigned int xid; // transaction ID, a random number chosen by the client, used by the client and server to associate messages and responses between a client and a server
    int secs; // filled in by client, seconds elapsed since client began address acquisition or renewal process
    bool broadcast; // the broadcast bit in the flags field
    uint16_t reserved = 0; // MUST BE ZERO (reserved for future use)
    Ipv4Address ciaddr; // client IP address; only filled in if client is in BOUND, RENEW or REBINDING state and can respond to Arp requests
    Ipv4Address yiaddr; // 'your' (client) IP address
    Ipv4Address giaddr; // relay agent IP address, used in booting via a relay agent
    MacAddress chaddr; // client hardware address (MAC)
    string sname; // optional server host name
    string file; // boot file name (unused in the simulation)
    DhcpOptions options; // holds DHCP options
}

File: src/inet/applications/dhcp/DhcpMessage.msg