Dynamic Host Configuration Protocol. More...

#include <stdint.h>
#include <stdarg.h>
#include <ipxe/in.h>
#include <ipxe/list.h>
#include <ipxe/refcnt.h>
#include <ipxe/tables.h>
#include <ipxe/uuid.h>
#include <ipxe/netdevice.h>
#include <ipxe/uaccess.h>

Data Structures
struct	dhcp_pxe_boot_server
	PXE boot server. More...

struct	dhcp_pxe_boot_menu
	PXE boot menu. More...

struct	dhcp_pxe_boot_menu_prompt
	PXE boot menu prompt. More...

struct	dhcp_pxe_boot_menu_item
	PXE boot menu item. More...

struct	dhcp_client_id
	Client identifier. More...

struct	dhcp_client_architecture
	DHCP client architecture. More...

struct	dhcp_client_uuid
	UUID client identifier. More...

struct	dhcp_netdev_desc
	Network device descriptor. More...

struct	dhcp_option
	A DHCP option. More...

struct	dhcphdr
	A DHCP header. More...

Macros
#define	BOOTPS_PORT 67
	BOOTP/DHCP server port. More...

#define	BOOTPC_PORT 68
	BOOTP/DHCP client port. More...

#define	PXE_PORT 4011
	PXE server port. More...

#define	DHCP_ENCAP_OPT(encapsulator, encapsulated) ( ( (encapsulator) << 8 ) \| (encapsulated) )
	Construct a tag value for an encapsulated option. More...

#define	DHCP_ENCAPSULATOR(encap_opt) ( (encap_opt) >> 8 )
	Extract encapsulating option block tag from encapsulated tag value. More...

#define	DHCP_ENCAPSULATED(encap_opt) ( (encap_opt) & 0xff )
	Extract encapsulated option tag from encapsulated tag value. More...

#define	DHCP_IS_ENCAP_OPT(opt) DHCP_ENCAPSULATOR( opt )
	Option is encapsulated. More...

#define	DHCP_PAD 0
	Padding. More...

#define	DHCP_MIN_OPTION 1
	Minimum normal DHCP option. More...

#define	DHCP_SUBNET_MASK 1
	Subnet mask. More...

#define	DHCP_ROUTERS 3
	Routers. More...

#define	DHCP_DNS_SERVERS 6
	DNS servers. More...

#define	DHCP_LOG_SERVERS 7
	Syslog servers. More...

#define	DHCP_HOST_NAME 12
	Host name. More...

#define	DHCP_DOMAIN_NAME 15
	Domain name. More...

#define	DHCP_ROOT_PATH 17
	Root path. More...

#define	DHCP_MTU 26
	Maximum transmission unit. More...

#define	DHCP_NTP_SERVERS 42
	NTP servers. More...

#define	DHCP_VENDOR_ENCAP 43
	Vendor encapsulated options. More...

#define	DHCP_PXE_DISCOVERY_CONTROL DHCP_ENCAP_OPT ( DHCP_VENDOR_ENCAP, 6 )
	PXE boot server discovery control. More...

#define	DHCP_PXE_BOOT_SERVER_MCAST DHCP_ENCAP_OPT ( DHCP_VENDOR_ENCAP, 7 )
	PXE boot server multicast address. More...

#define	DHCP_PXE_BOOT_SERVERS DHCP_ENCAP_OPT ( DHCP_VENDOR_ENCAP, 8 )
	PXE boot servers. More...

#define	DHCP_PXE_BOOT_MENU DHCP_ENCAP_OPT ( DHCP_VENDOR_ENCAP, 9 )
	PXE boot menu. More...

#define	DHCP_PXE_BOOT_MENU_PROMPT DHCP_ENCAP_OPT ( DHCP_VENDOR_ENCAP, 10 )
	PXE boot menu prompt. More...

#define	DHCP_PXE_BOOT_MENU_ITEM DHCP_ENCAP_OPT ( DHCP_VENDOR_ENCAP, 71 )
	PXE boot menu item. More...

#define	DHCP_REQUESTED_ADDRESS 50
	Requested IP address. More...

#define	DHCP_LEASE_TIME 51
	Lease time. More...

#define	DHCP_OPTION_OVERLOAD 52
	Option overloading. More...

#define	DHCP_OPTION_OVERLOAD_FILE 1
	The "file" field is overloaded to contain extra DHCP options. More...

#define	DHCP_OPTION_OVERLOAD_SNAME 2
	The "sname" field is overloaded to contain extra DHCP options. More...

#define	DHCP_MESSAGE_TYPE 53
	DHCP message type. More...

#define	DHCPNONE 0

#define	DHCPDISCOVER 1

#define	DHCPOFFER 2

#define	DHCPREQUEST 3

#define	DHCPDECLINE 4

#define	DHCPACK 5

#define	DHCPNAK 6

#define	DHCPRELEASE 7

#define	DHCPINFORM 8

#define	DHCP_SERVER_IDENTIFIER 54
	DHCP server identifier. More...

#define	DHCP_PARAMETER_REQUEST_LIST 55
	Parameter request list. More...

#define	DHCP_MAX_MESSAGE_SIZE 57
	Maximum DHCP message size. More...

#define	DHCP_VENDOR_CLASS_ID 60
	Vendor class identifier. More...

#define	DHCP_VENDOR_PXECLIENT(arch, ndi)
	Vendor class identifier for PXE clients. More...

#define	DHCP_VENDOR_PXECLIENT_ARCH(arch)
	Vendor class identifier architecture for PXE clients. More...

#define	DHCP_VENDOR_PXECLIENT_UNDI(type, major, minor)
	Vendor class identifier UNDI version for PXE clients. More...

#define	DHCP_VENDOR_PXECLIENT_UNDI_VERSION(version)

#define	DHCP_CLIENT_ID 61
	Client identifier. More...

#define	DHCP_TFTP_SERVER_NAME 66
	TFTP server name. More...

#define	DHCP_BOOTFILE_NAME 67
	Bootfile name. More...

#define	DHCP_USER_CLASS_ID 77
	User class identifier. More...

#define	DHCP_CLIENT_ARCHITECTURE 93
	Client system architecture. More...

#define	DHCP_CLIENT_NDI 94
	Client network device interface. More...

#define	DHCP_CLIENT_UUID 97
	UUID client identifier. More...

#define	DHCP_CLIENT_UUID_TYPE 0

#define	DHCP_DOMAIN_SEARCH 119
	DNS domain search list. More...

#define	DHCP_EB_ENCAP 175
	Etherboot-specific encapsulated options. More...

#define	DHCP_EB_PRIORITY DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0x01 )
	Priority of this options block. More...

#define	DHCP_EB_YIADDR DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0x02 )
	"Your" IP address More...

#define	DHCP_EB_SIADDR DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0x03 )
	"Server" IP address More...

#define	DHCP_EB_KEEP_SAN DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0x08 )
	Keep SAN drive registered. More...

#define	DHCP_EB_SKIP_SAN_BOOT DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0x09 )
	Skip booting from SAN drive. More...

#define	DHCP_EB_SCRIPTLET DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0x51 )
	Scriptlet. More...

#define	DHCP_EB_SYSLOGS_SERVER DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0x55 )
	Encrypted syslog server. More...

#define	DHCP_EB_TRUST DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0x5a )
	Trusted root certficate fingerprints. More...

#define	DHCP_EB_CERT DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0x5b )
	Client certficate. More...

#define	DHCP_EB_KEY DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0x5c )
	Client private key. More...

#define	DHCP_EB_CROSS_CERT DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0x5d )
	Cross-signed certificate source. More...

#define	DHCP_EB_NO_PXEDHCP DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xb0 )
	Skip PXE DHCP protocol extensions such as ProxyDHCP. More...

#define	DHCP_EB_BUS_ID DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xb1 )
	Network device descriptor. More...

#define	DHCP_EB_USE_CACHED DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xb2 )
	Use cached network settings (obsolete; do not reuse this value) More...

#define	DHCP_EB_SAN_RETRY DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xbb )
	SAN retry count. More...

#define	DHCP_EB_SAN_FILENAME DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xbc )
	SAN filename. More...

#define	DHCP_EB_SAN_DRIVE DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xbd )
	SAN drive number. More...

#define	DHCP_EB_USERNAME DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xbe )
	Username. More...

#define	DHCP_EB_PASSWORD DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xbf )
	Password. More...

#define	DHCP_EB_REVERSE_USERNAME DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xc0 )
	Reverse username. More...

#define	DHCP_EB_REVERSE_PASSWORD DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xc1 )
	Reverse password. More...

#define	DHCP_EB_UID DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xc2 )
	User ID. More...

#define	DHCP_EB_GID DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xc3 )
	Group ID. More...

#define	DHCP_EB_VERSION DHCP_ENCAP_OPT ( DHCP_EB_ENCAP, 0xeb )
	iPXE version number More...

#define	DHCP_ISCSI_PRIMARY_TARGET_IQN 201
	iSCSI primary target IQN More...

#define	DHCP_ISCSI_SECONDARY_TARGET_IQN 202
	iSCSI secondary target IQN More...

#define	DHCP_ISCSI_INITIATOR_IQN 203
	iSCSI initiator IQN More...

#define	DHCP_MAX_OPTION 254
	Maximum normal DHCP option. More...

#define	DHCP_END 255
	End of options. More...

#define	DHCP_OPTION(...) VA_ARG_COUNT ( __VA_ARGS__ ), __VA_ARGS__
	Construct a DHCP option from a list of bytes. More...

#define	DHCP_STRING(...) DHCP_OPTION ( __VA_ARGS__ )
	Construct a DHCP option from a list of characters. More...

#define	DHCP_BYTE(value) DHCP_OPTION ( value )
	Construct a byte-valued DHCP option. More...

#define	DHCP_WORD(value)
	Construct a word-valued DHCP option. More...

#define	DHCP_DWORD(value)
	Construct a dword-valued DHCP option. More...

#define	DHCP_ENCAP(...) DHCP_OPTION ( __VA_ARGS__, DHCP_END )
	Construct a DHCP encapsulated options field. More...

#define	DHCP_OPTION_HEADER_LEN ( offsetof ( struct dhcp_option, data ) )
	Length of a DHCP option header. More...

#define	DHCP_MAX_LEN 0xff
	Maximum length for a single DHCP option. More...

#define	BOOTP_REQUEST 1
	Opcode for a request from client to server. More...

#define	BOOTP_REPLY 2
	Opcode for a reply from server to client. More...

#define	BOOTP_FL_BROADCAST 0x8000
	BOOTP reply must be broadcast. More...

#define	DHCP_MAGIC_COOKIE 0x63825363UL
	DHCP magic cookie. More...

#define	DHCP_MIN_LEN 552
	DHCP minimum packet length. More...

#define	DHCP_SETTINGS_NAME "dhcp"
	Settings block name used for DHCP responses. More...

#define	PROXYDHCP_SETTINGS_NAME "proxydhcp"
	Settings block name used for ProxyDHCP responses. More...

#define	PXEBS_SETTINGS_NAME "pxebs"
	Setting block name used for BootServerDHCP responses. More...

Enumerations
enum	dhcp_pxe_discovery_control { PXEBS_NO_BROADCAST = 1, PXEBS_NO_MULTICAST = 2, PXEBS_NO_UNKNOWN_SERVERS = 4, PXEBS_SKIP = 8 }
	PXE boot server discovery control bits. More...

enum	dhcp_client_architecture_values { DHCP_CLIENT_ARCHITECTURE_X86 = 0x0000, DHCP_CLIENT_ARCHITECTURE_PC98 = 0x0001, DHCP_CLIENT_ARCHITECTURE_IA64 = 0x0002, DHCP_CLIENT_ARCHITECTURE_ALPHA = 0x0003, DHCP_CLIENT_ARCHITECTURE_ARCX86 = 0x0004, DHCP_CLIENT_ARCHITECTURE_LC = 0x0005, DHCP_CLIENT_ARCHITECTURE_IA32 = 0x0006, DHCP_CLIENT_ARCHITECTURE_X86_64 = 0x0007, DHCP_CLIENT_ARCHITECTURE_XSCALE = 0x0008, DHCP_CLIENT_ARCHITECTURE_EFI = 0x0009, DHCP_CLIENT_ARCHITECTURE_ARM32 = 0x000a, DHCP_CLIENT_ARCHITECTURE_ARM64 = 0x000b, DHCP_CLIENT_ARCHITECTURE_RISCV32 = 0x0019, DHCP_CLIENT_ARCHITECTURE_RISCV64 = 0x001b, DHCP_CLIENT_ARCHITECTURE_RISCV128 = 0x001d, DHCP_CLIENT_ARCHITECTURE_MIPS32 = 0x0021, DHCP_CLIENT_ARCHITECTURE_MIPS64 = 0x0022, DHCP_CLIENT_ARCHITECTURE_SUNWAY32 = 0x0023, DHCP_CLIENT_ARCHITECTURE_SUNWAY64 = 0x0024, DHCP_CLIENT_ARCHITECTURE_LOONG32 = 0x0025, DHCP_CLIENT_ARCHITECTURE_LOONG64 = 0x0027 }
	DHCP client architecture values. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)

int	dhcp_create_packet (struct dhcp_packet dhcppkt, struct net_device netdev, uint8_t msgtype, uint32_t xid, const void options, size_t options_len, void data, size_t max_len)
	Create a DHCP packet. More...

int	dhcp_create_request (struct dhcp_packet dhcppkt, struct net_device netdev, unsigned int msgtype, uint32_t xid, struct in_addr ciaddr, void *data, size_t max_len)
	Create DHCP request packet. More...

int	start_dhcp (struct interface job, struct net_device netdev)
	Start DHCP state machine on a network device. More...

int	start_pxebs (struct interface job, struct net_device netdev, unsigned int pxe_type)
	Start PXE Boot Server Discovery on a network device. More...

Variables
uint32_t	dhcp_last_xid
	Most recent DHCP transaction ID. More...

Detailed Description

Dynamic Host Configuration Protocol.

Definition in file dhcp.h.

Macro Definition Documentation

◆ BOOTPS_PORT

#define BOOTPS_PORT 67

BOOTP/DHCP server port.

Definition at line 27 of file dhcp.h.

◆ BOOTPC_PORT

#define BOOTPC_PORT 68

BOOTP/DHCP client port.

Definition at line 30 of file dhcp.h.

◆ PXE_PORT

#define PXE_PORT 4011

PXE server port.

Definition at line 33 of file dhcp.h.

◆ DHCP_ENCAP_OPT

#define DHCP_ENCAP_OPT	(	encapsulator,
		encapsulated
	)	( ( (encapsulator) << 8 ) \| (encapsulated) )

Construct a tag value for an encapsulated option.

This tag value can be passed to Etherboot functions when searching for DHCP options in order to search for a tag within an encapsulated options block.

Definition at line 41 of file dhcp.h.

◆ DHCP_ENCAPSULATOR

#define DHCP_ENCAPSULATOR ( encap_opt ) ( (encap_opt) >> 8 )

Extract encapsulating option block tag from encapsulated tag value.

Definition at line 44 of file dhcp.h.

◆ DHCP_ENCAPSULATED

#define DHCP_ENCAPSULATED ( encap_opt ) ( (encap_opt) & 0xff )

Extract encapsulated option tag from encapsulated tag value.

Definition at line 46 of file dhcp.h.

◆ DHCP_IS_ENCAP_OPT

#define DHCP_IS_ENCAP_OPT ( opt ) DHCP_ENCAPSULATOR( opt )

Option is encapsulated.

Definition at line 48 of file dhcp.h.

◆ DHCP_OPTION

#define DHCP_OPTION ( ... ) VA_ARG_COUNT ( __VA_ARGS__ ), __VA_ARGS__

Construct a DHCP option from a list of bytes.

Definition at line 551 of file dhcp.h.

◆ DHCP_STRING

#define DHCP_STRING ( ... ) DHCP_OPTION ( __VA_ARGS__ )

Construct a DHCP option from a list of characters.

Definition at line 554 of file dhcp.h.

◆ DHCP_BYTE

#define DHCP_BYTE ( value ) DHCP_OPTION ( value )

Construct a byte-valued DHCP option.

Definition at line 557 of file dhcp.h.

◆ DHCP_WORD

#define DHCP_WORD ( value )

Value:

DHCP_OPTION ( ( ( (value) >> 8 ) & 0xff ), \

( ( (value) >> 0 ) & 0xff ) )

value

pseudo_bit_t value[0x00020]

Definition: arbel.h:13

DHCP_OPTION

#define DHCP_OPTION(...)

Construct a DHCP option from a list of bytes.

Definition: dhcp.h:551

Construct a word-valued DHCP option.

Definition at line 560 of file dhcp.h.

◆ DHCP_DWORD

#define DHCP_DWORD ( value )

Value:

DHCP_OPTION ( ( ( (value) >> 24 ) & 0xff ), \
                                          ( ( (value) >> 16 ) & 0xff ), \
                                          ( ( (value) >> 8  ) & 0xff ), \
                                          ( ( (value) >> 0  ) & 0xff ) )

Construct a dword-valued DHCP option.

Definition at line 564 of file dhcp.h.

◆ DHCP_ENCAP

#define DHCP_ENCAP ( ... ) DHCP_OPTION ( __VA_ARGS__, DHCP_END )

Construct a DHCP encapsulated options field.

Definition at line 570 of file dhcp.h.

◆ DHCP_OPTION_HEADER_LEN

#define DHCP_OPTION_HEADER_LEN ( offsetof ( struct dhcp_option, data ) )

Length of a DHCP option header.

The header is the portion excluding the data, i.e. the tag and the length.

Definition at line 604 of file dhcp.h.

◆ DHCP_MAX_LEN

#define DHCP_MAX_LEN 0xff

Maximum length for a single DHCP option.

Definition at line 607 of file dhcp.h.

◆ BOOTP_REQUEST

#define BOOTP_REQUEST 1

Opcode for a request from client to server.

Definition at line 685 of file dhcp.h.

◆ BOOTP_REPLY

#define BOOTP_REPLY 2

Opcode for a reply from server to client.

Definition at line 688 of file dhcp.h.

◆ BOOTP_FL_BROADCAST

#define BOOTP_FL_BROADCAST 0x8000

BOOTP reply must be broadcast.

Clients that cannot accept unicast BOOTP replies must set this flag.

Definition at line 695 of file dhcp.h.

◆ DHCP_MAGIC_COOKIE

#define DHCP_MAGIC_COOKIE 0x63825363UL

DHCP magic cookie.

Definition at line 698 of file dhcp.h.

◆ DHCP_MIN_LEN

#define DHCP_MIN_LEN 552

DHCP minimum packet length.

This is the mandated minimum packet length that a DHCP participant must be prepared to receive.

Definition at line 705 of file dhcp.h.

◆ DHCP_SETTINGS_NAME

#define DHCP_SETTINGS_NAME "dhcp"

Settings block name used for DHCP responses.

Definition at line 708 of file dhcp.h.

◆ PROXYDHCP_SETTINGS_NAME

#define PROXYDHCP_SETTINGS_NAME "proxydhcp"

Settings block name used for ProxyDHCP responses.

Definition at line 711 of file dhcp.h.

◆ PXEBS_SETTINGS_NAME

#define PXEBS_SETTINGS_NAME "pxebs"

Setting block name used for BootServerDHCP responses.

Definition at line 714 of file dhcp.h.

Function Documentation

◆ FILE_LICENCE()

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL )

◆ dhcp_create_packet()

int dhcp_create_packet	(	struct dhcp_packet *	dhcppkt,
		struct net_device *	netdev,
		uint8_t	msgtype,
		uint32_t	xid,
		const void *	options,
		size_t	options_len,
		void *	data,
		size_t	max_len
	)

Create a DHCP packet.

Parameters

dhcppkt	DHCP packet structure to fill in
netdev	Network device
msgtype	DHCP message type
xid	Transaction ID (in network-endian order)
options	Initial options to include (or NULL)
options_len	Length of initial options
data	Buffer for DHCP packet
max_len	Size of DHCP packet buffer

Return values

rc	Return status code

Creates a DHCP packet in the specified buffer, and initialise a DHCP packet structure.

Definition at line 944 of file dhcp.c.

                                                       {
         struct dhcphdr *dhcphdr = data;
         int rc;
 
         /* Sanity check */
         if ( max_len < ( sizeof ( *dhcphdr ) + options_len ) )
                 return -ENOSPC;
 
         /* Initialise DHCP packet content */
         memset ( dhcphdr, 0, max_len );
         dhcphdr->xid = xid;
         dhcphdr->magic = htonl ( DHCP_MAGIC_COOKIE );
         dhcphdr->htype = ntohs ( netdev->ll_protocol->ll_proto );
         dhcphdr->op = dhcp_op[msgtype];
         dhcphdr->hlen = netdev->ll_protocol->ll_addr_len;
         memcpy ( dhcphdr->chaddr, netdev->ll_addr,
                  netdev->ll_protocol->ll_addr_len );
         memcpy ( dhcphdr->options, options, options_len );
 
         /* If the local link-layer address functions only as a name
          * (i.e. cannot be used as a destination address), then
          * request broadcast responses.
          */
         if ( netdev->ll_protocol->flags & LL_NAME_ONLY )
                 dhcphdr->flags |= htons ( BOOTP_FL_BROADCAST );
 
         /* If the network device already has an IPv4 address then
          * unicast responses from the DHCP server may be rejected, so
          * request broadcast responses.
          */
         if ( ipv4_has_any_addr ( netdev ) )
                 dhcphdr->flags |= htons ( BOOTP_FL_BROADCAST );
 
         /* Initialise DHCP packet structure */
         memset ( dhcppkt, 0, sizeof ( *dhcppkt ) );
         dhcppkt_init ( dhcppkt, data, max_len );
         
         /* Set DHCP_MESSAGE_TYPE option */
         if ( ( rc = dhcppkt_store ( dhcppkt, DHCP_MESSAGE_TYPE,
                                     &msgtype, sizeof ( msgtype ) ) ) != 0 )
                 return rc;
 
         return 0;
 }

References BOOTP_FL_BROADCAST, dhcphdr::chaddr, data, DHCP_MAGIC_COOKIE, DHCP_MESSAGE_TYPE, dhcp_op, dhcppkt_init(), dhcppkt_store(), ENOSPC, ll_protocol::flags, dhcphdr::flags, dhcphdr::hlen, htonl, htons, dhcphdr::htype, ipv4_has_any_addr(), net_device::ll_addr, ll_protocol::ll_addr_len, LL_NAME_ONLY, ll_protocol::ll_proto, net_device::ll_protocol, dhcphdr::magic, max_len, memcpy(), memset(), netdev, ntohs, dhcphdr::op, options, dhcphdr::options, rc, and dhcphdr::xid.

Referenced by create_fakedhcpack(), create_fakepxebsack(), and dhcp_create_request().

◆ dhcp_create_request()

int dhcp_create_request	(	struct dhcp_packet *	dhcppkt,
		struct net_device *	netdev,
		unsigned int	msgtype,
		uint32_t	xid,
		struct in_addr	ciaddr,
		void *	data,
		size_t	max_len
	)

Create DHCP request packet.

Parameters

dhcppkt	DHCP packet structure to fill in
netdev	Network device
msgtype	DHCP message type
xid	Transaction ID (in network-endian order)
ciaddr	Client IP address
data	Buffer for DHCP packet
max_len	Size of DHCP packet buffer

Return values

rc	Return status code

Creates a DHCP request packet in the specified buffer, and initialise a DHCP packet structure.

Definition at line 1007 of file dhcp.c.

                                                        {
         struct dhcp_netdev_desc dhcp_desc;
         struct dhcp_client_id client_id;
         struct dhcp_client_uuid client_uuid;
         const struct setting *setting;
         uint8_t *dhcp_features;
         size_t dhcp_features_len;
         size_t ll_addr_len;
         void *raw;
         ssize_t len;
         unsigned int i;
         int rc;
 
         /* Create DHCP packet */
         if ( ( rc = dhcp_create_packet ( dhcppkt, netdev, msgtype, xid,
                                          dhcp_request_options_data,
                                          sizeof ( dhcp_request_options_data ),
                                          data, max_len ) ) != 0 ) {
                 DBG ( "DHCP could not create DHCP packet: %s\n",
                       strerror ( rc ) );
                 goto err_create_packet;
         }
 
         /* Set client IP address */
         dhcppkt->dhcphdr->ciaddr = ciaddr;
 
         /* Add options to identify the feature list */
         dhcp_features = table_start ( DHCP_FEATURES );
         dhcp_features_len = table_num_entries ( DHCP_FEATURES );
         if ( ( rc = dhcppkt_store ( dhcppkt, DHCP_EB_ENCAP, dhcp_features,
                                     dhcp_features_len ) ) != 0 ) {
                 DBG ( "DHCP could not set features list option: %s\n",
                       strerror ( rc ) );
                 goto err_store_features;
         }
 
         /* Add options to identify the network device */
         fetch_raw_setting ( netdev_settings ( netdev ), &busid_setting,
                             &dhcp_desc, sizeof ( dhcp_desc ) );
         if ( ( rc = dhcppkt_store ( dhcppkt, DHCP_EB_BUS_ID, &dhcp_desc,
                                     sizeof ( dhcp_desc ) ) ) != 0 ) {
                 DBG ( "DHCP could not set bus ID option: %s\n",
                       strerror ( rc ) );
                 goto err_store_busid;
         }
 
         /* Add DHCP client identifier.  Required for Infiniband, and
          * doesn't hurt other link layers.
          */
         client_id.ll_proto = ntohs ( netdev->ll_protocol->ll_proto );
         ll_addr_len = netdev->ll_protocol->ll_addr_len;
         assert ( ll_addr_len <= sizeof ( client_id.ll_addr ) );
         memcpy ( client_id.ll_addr, netdev->ll_addr, ll_addr_len );
         if ( ( rc = dhcppkt_store ( dhcppkt, DHCP_CLIENT_ID, &client_id,
                                     ( ll_addr_len + 1 ) ) ) != 0 ) {
                 DBG ( "DHCP could not set client ID: %s\n",
                       strerror ( rc ) );
                 goto err_store_client_id;
         }
 
         /* Add client UUID, if we have one.  Required for PXE.  The
          * PXE spec does not specify a byte ordering for UUIDs, but
          * RFC4578 suggests that it follows the EFI spec, in which the
          * first three fields are little-endian.
          */
         client_uuid.type = DHCP_CLIENT_UUID_TYPE;
         if ( ( len = fetch_uuid_setting ( NULL, &uuid_setting,
                                           &client_uuid.uuid ) ) >= 0 ) {
                 uuid_mangle ( &client_uuid.uuid );
                 if ( ( rc = dhcppkt_store ( dhcppkt, DHCP_CLIENT_UUID,
                                             &client_uuid,
                                             sizeof ( client_uuid ) ) ) != 0 ) {
                         DBG ( "DHCP could not set client UUID: %s\n",
                               strerror ( rc ) );
                         goto err_store_client_uuid;
                 }
         }
 
         /* Add request settings, if applicable */
         for ( i = 0 ; i < ( sizeof ( dhcp_request_settings ) /
                             sizeof ( dhcp_request_settings[0] ) ) ; i++ ) {
                 setting = dhcp_request_settings[i];
                 if ( ( len = fetch_raw_setting_copy ( NULL, setting,
                                                       &raw ) ) >= 0 ) {
                         rc = dhcppkt_store ( dhcppkt, setting->tag, raw, len );
                         free ( raw );
                         if ( rc != 0 ) {
                                 DBG ( "DHCP could not set %s: %s\n",
                                       setting->name, strerror ( rc ) );
                                 goto err_store_raw;
                         }
                 }
         }
 
  err_store_raw:
  err_store_client_uuid:
  err_store_client_id:
  err_store_busid:
  err_store_features:
  err_create_packet:
         return rc;
 }

References assert(), dhcphdr::ciaddr, data, DBG, DHCP_CLIENT_ID, DHCP_CLIENT_UUID, DHCP_CLIENT_UUID_TYPE, dhcp_create_packet(), DHCP_EB_BUS_ID, DHCP_EB_ENCAP, DHCP_FEATURES, dhcp_request_options_data, dhcp_request_settings, dhcp_packet::dhcphdr, dhcppkt_store(), fetch_raw_setting(), fetch_raw_setting_copy(), fetch_uuid_setting(), free, len, dhcp_client_id::ll_addr, net_device::ll_addr, ll_protocol::ll_addr_len, ll_protocol::ll_proto, dhcp_client_id::ll_proto, net_device::ll_protocol, max_len, memcpy(), setting::name, netdev, netdev_settings(), ntohs, NULL, raw, rc, strerror(), table_num_entries, table_start, setting::tag, dhcp_client_uuid::type, dhcp_client_uuid::uuid, and uuid_mangle().

Referenced by create_fakedhcpdiscover(), and dhcp_tx().

◆ start_dhcp()

int start_dhcp	(	struct interface *	job,
		struct net_device *	netdev
	)

Start DHCP state machine on a network device.

Parameters

job	Job control interface
netdev	Network device

Return values

rc	Return status code

Starts DHCP on the specified network device. If successful, the DHCPACK (and ProxyDHCPACK, if applicable) will be registered as option sources.

Definition at line 1357 of file dhcp.c.

                                                                     {
         struct dhcp_session *dhcp;
         int rc;
 
         /* Allocate and initialise structure */
         dhcp = zalloc ( sizeof ( *dhcp ) );
         if ( ! dhcp )
                 return -ENOMEM;
         ref_init ( &dhcp->refcnt, dhcp_free );
         intf_init ( &dhcp->job, &dhcp_job_desc, &dhcp->refcnt );
         intf_init ( &dhcp->xfer, &dhcp_xfer_desc, &dhcp->refcnt );
         timer_init ( &dhcp->timer, dhcp_timer_expired, &dhcp->refcnt );
         dhcp->netdev = netdev_get ( netdev );
         dhcp->local.sin_family = AF_INET;
         dhcp->local.sin_port = htons ( BOOTPC_PORT );
         dhcp->xid = random();
 
         /* Store DHCP transaction ID for fakedhcp code */
         dhcp_last_xid = dhcp->xid;
 
         /* Instantiate child objects and attach to our interfaces */
         if ( ( rc = xfer_open_socket ( &dhcp->xfer, SOCK_DGRAM, &dhcp_peer,
                                   ( struct sockaddr * ) &dhcp->local ) ) != 0 )
                 goto err;
 
         /* Enter DHCPDISCOVER state */
         dhcp_set_state ( dhcp, &dhcp_state_discover );
 
         /* Attach parent interface, mortalise self, and return */
         intf_plug_plug ( &dhcp->job, job );
         ref_put ( &dhcp->refcnt );
         return 0;
 
  err:
         dhcp_finished ( dhcp, rc );
         ref_put ( &dhcp->refcnt );
         return rc;
 }

References AF_INET, BOOTPC_PORT, dhcp_finished(), dhcp_free(), dhcp_job_desc, dhcp_last_xid, dhcp_peer, dhcp_set_state(), dhcp_state_discover, dhcp_timer_expired(), dhcp_xfer_desc, ENOMEM, htons, intf_init(), intf_plug_plug(), dhcp_session::job, dhcp_session::local, netdev, dhcp_session::netdev, netdev_get(), random(), rc, ref_init, ref_put, dhcp_session::refcnt, sockaddr_in::sin_family, sockaddr_in::sin_port, SOCK_DGRAM, dhcp_session::timer, dhcp_session::xfer, xfer_open_socket(), dhcp_session::xid, and zalloc().

◆ start_pxebs()

int start_pxebs	(	struct interface *	job,
		struct net_device *	netdev,
		unsigned int	pxe_type
	)

Start PXE Boot Server Discovery on a network device.

Parameters

job	Job control interface
netdev	Network device
pxe_type	PXE server type

Return values

rc	Return status code

Starts PXE Boot Server Discovery on the specified network device. If successful, the Boot Server ACK will be registered as an option source.

Definition at line 1447 of file dhcp.c.

                                           {
         struct setting pxe_discovery_control_setting =
                 { .tag = DHCP_PXE_DISCOVERY_CONTROL };
         struct setting pxe_boot_servers_setting =
                 { .tag = DHCP_PXE_BOOT_SERVERS };
         struct setting pxe_boot_server_mcast_setting =
                 { .tag = DHCP_PXE_BOOT_SERVER_MCAST };
         ssize_t pxebs_list_len;
         struct dhcp_session *dhcp;
         struct in_addr *ip;
         unsigned int pxe_discovery_control;
         int rc;
 
         /* Get upper bound for PXE boot server IP address list */
         pxebs_list_len = fetch_raw_setting ( NULL, &pxe_boot_servers_setting,
                                              NULL, 0 );
         if ( pxebs_list_len < 0 )
                 pxebs_list_len = 0;
 
         /* Allocate and initialise structure */
         dhcp = zalloc ( sizeof ( *dhcp ) + sizeof ( *ip ) /* mcast */ +
                         sizeof ( *ip ) /* bcast */ + pxebs_list_len +
                         sizeof ( *ip ) /* terminator */ );
         if ( ! dhcp )
                 return -ENOMEM;
         ref_init ( &dhcp->refcnt, dhcp_free );
         intf_init ( &dhcp->job, &dhcp_job_desc, &dhcp->refcnt );
         intf_init ( &dhcp->xfer, &dhcp_xfer_desc, &dhcp->refcnt );
         timer_init ( &dhcp->timer, dhcp_timer_expired, &dhcp->refcnt );
         dhcp->netdev = netdev_get ( netdev );
         dhcp->local.sin_family = AF_INET;
         fetch_ipv4_setting ( netdev_settings ( netdev ), &ip_setting,
                              &dhcp->local.sin_addr );
         dhcp->local.sin_port = htons ( BOOTPC_PORT );
         dhcp->pxe_type = cpu_to_le16 ( pxe_type );
 
         /* Construct PXE boot server IP address lists */
         pxe_discovery_control =
                 fetch_uintz_setting ( NULL, &pxe_discovery_control_setting );
         ip = ( ( ( void * ) dhcp ) + sizeof ( *dhcp ) );
         dhcp->pxe_attempt = ip;
         if ( ! ( pxe_discovery_control & PXEBS_NO_MULTICAST ) ) {
                 fetch_ipv4_setting ( NULL, &pxe_boot_server_mcast_setting, ip);
                 if ( ip->s_addr )
                         ip++;
         }
         if ( ! ( pxe_discovery_control & PXEBS_NO_BROADCAST ) )
                 (ip++)->s_addr = INADDR_BROADCAST;
         if ( pxe_discovery_control & PXEBS_NO_UNKNOWN_SERVERS )
                 dhcp->pxe_accept = ip;
         if ( pxebs_list_len ) {
                 uint8_t buf[pxebs_list_len];
 
                 fetch_raw_setting ( NULL, &pxe_boot_servers_setting,
                                     buf, sizeof ( buf ) );
                 pxebs_list ( dhcp, buf, sizeof ( buf ), ip );
         }
         if ( ! dhcp->pxe_attempt->s_addr ) {
                 DBGC ( dhcp, "DHCP %p has no PXE boot servers for type %04x\n",
                        dhcp, pxe_type );
                 rc = -EINVAL;
                 goto err;
         }
 
         /* Dump out PXE server lists */
         DBGC ( dhcp, "DHCP %p attempting", dhcp );
         for ( ip = dhcp->pxe_attempt ; ip->s_addr ; ip++ )
                 DBGC ( dhcp, " %s", inet_ntoa ( *ip ) );
         DBGC ( dhcp, "\n" );
         if ( dhcp->pxe_accept ) {
                 DBGC ( dhcp, "DHCP %p accepting", dhcp );
                 for ( ip = dhcp->pxe_accept ; ip->s_addr ; ip++ )
                         DBGC ( dhcp, " %s", inet_ntoa ( *ip ) );
                 DBGC ( dhcp, "\n" );
         }
 
         /* Instantiate child objects and attach to our interfaces */
         if ( ( rc = xfer_open_socket ( &dhcp->xfer, SOCK_DGRAM, &dhcp_peer,
                                   ( struct sockaddr * ) &dhcp->local ) ) != 0 )
                 goto err;
 
         /* Enter PXEBS state */
         dhcp_set_state ( dhcp, &dhcp_state_pxebs );
 
         /* Attach parent interface, mortalise self, and return */
         intf_plug_plug ( &dhcp->job, job );
         ref_put ( &dhcp->refcnt );
         return 0;
 
  err:
         dhcp_finished ( dhcp, rc );
         ref_put ( &dhcp->refcnt );
         return rc;
 }

References AF_INET, BOOTPC_PORT, cpu_to_le16, DBGC, dhcp_finished(), dhcp_free(), dhcp_job_desc, dhcp_peer, DHCP_PXE_BOOT_SERVER_MCAST, DHCP_PXE_BOOT_SERVERS, DHCP_PXE_DISCOVERY_CONTROL, dhcp_set_state(), dhcp_state_pxebs, dhcp_timer_expired(), dhcp_xfer_desc, EINVAL, ENOMEM, fetch_ipv4_setting(), fetch_raw_setting(), fetch_uintz_setting(), htons, INADDR_BROADCAST, inet_ntoa(), intf_init(), intf_plug_plug(), ip, dhcp_session::job, dhcp_session::local, netdev, dhcp_session::netdev, netdev_get(), netdev_settings(), NULL, dhcp_session::pxe_accept, dhcp_session::pxe_attempt, dhcp_session::pxe_type, pxebs_list(), PXEBS_NO_BROADCAST, PXEBS_NO_MULTICAST, PXEBS_NO_UNKNOWN_SERVERS, rc, ref_init, ref_put, dhcp_session::refcnt, in_addr::s_addr, sockaddr_in::sin_addr, sockaddr_in::sin_family, sockaddr_in::sin_port, SOCK_DGRAM, setting::tag, dhcp_session::timer, dhcp_session::xfer, xfer_open_socket(), and zalloc().

Referenced by pxebs().

Variable Documentation

◆ dhcp_last_xid

uint32_t dhcp_last_xid

Most recent DHCP transaction ID.

This is exposed for use by the fakedhcp code when reconstructing DHCP packets for PXE NBPs.

Definition at line 124 of file dhcp.c.

Referenced by create_fakedhcpack(), create_fakedhcpdiscover(), create_fakepxebsack(), and start_dhcp().

Data Structures

Macros

Enumerations

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ BOOTPS_PORT

◆ BOOTPC_PORT

◆ PXE_PORT

◆ DHCP_ENCAP_OPT

◆ DHCP_ENCAPSULATOR

◆ DHCP_ENCAPSULATED

◆ DHCP_IS_ENCAP_OPT

◆ DHCP_OPTION

◆ DHCP_STRING

◆ DHCP_BYTE

◆ DHCP_WORD

◆ DHCP_DWORD

◆ DHCP_ENCAP

◆ DHCP_OPTION_HEADER_LEN

◆ DHCP_MAX_LEN

◆ BOOTP_REQUEST

◆ BOOTP_REPLY

◆ BOOTP_FL_BROADCAST

◆ DHCP_MAGIC_COOKIE

◆ DHCP_MIN_LEN

◆ DHCP_SETTINGS_NAME

◆ PROXYDHCP_SETTINGS_NAME

◆ PXEBS_SETTINGS_NAME

Function Documentation

◆ FILE_LICENCE()

◆ dhcp_create_packet()

◆ dhcp_create_request()

◆ start_dhcp()

◆ start_pxebs()

Variable Documentation

◆ dhcp_last_xid