dhcppkt.h File Reference

DHCP packets. More...

#include <ipxe/dhcp.h>
#include <ipxe/dhcpopts.h>
#include <ipxe/refcnt.h>

Go to the source code of this file.

Data Structures
struct	dhcp_packet
	A DHCP packet. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static struct dhcp_packet *	dhcppkt_get (struct dhcp_packet *dhcppkt)
	Increment reference count on DHCP packet. More...
static void	dhcppkt_put (struct dhcp_packet *dhcppkt)
	Decrement reference count on DHCP packet. More...
static size_t	dhcppkt_len (struct dhcp_packet *dhcppkt)
	Get used length of DHCP packet. More...
int	dhcppkt_store (struct dhcp_packet *dhcppkt, unsigned int tag, const void *data, size_t len)
	Store value of DHCP packet setting. More...
int	dhcppkt_fetch (struct dhcp_packet *dhcppkt, unsigned int tag, void *data, size_t len)
	Fetch value of DHCP packet setting. More...
void	dhcppkt_init (struct dhcp_packet *dhcppkt, struct dhcphdr *data, size_t len)
	Initialise DHCP packet. More...

Detailed Description

DHCP packets.

Definition in file dhcppkt.h.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

dhcppkt_get()

static struct dhcp_packet* dhcppkt_get ( struct dhcp_packet *  dhcppkt )

inlinestatic

Increment reference count on DHCP packet.

Parameters

dhcppkt

DHCP packet

Return values

dhcppkt

DHCP packet

Definition at line 38 of file dhcppkt.h.

                                            {
        ref_get ( &dhcppkt->refcnt );
        return dhcppkt;
}

References ref_get, and dhcp_packet::refcnt.

Referenced by dhcp_discovery_rx().

dhcppkt_put()

static void dhcppkt_put ( struct dhcp_packet *  dhcppkt )

inlinestatic

Decrement reference count on DHCP packet.

Parameters

dhcppkt

DHCP packet

Definition at line 49 of file dhcppkt.h.

                                            {
        ref_put ( &dhcppkt->refcnt );
}

References ref_put, and dhcp_packet::refcnt.

Referenced by cachedhcp_free(), cachedhcp_record(), dhcp_deliver(), dhcp_discovery_rx(), and dhcp_free().

dhcppkt_len()

static size_t dhcppkt_len ( struct dhcp_packet *  dhcppkt )

inlinestatic

Get used length of DHCP packet.

Parameters

dhcppkt

DHCP packet

Return values

len	Used length

Definition at line 59 of file dhcppkt.h.

                                                                 {
        return ( offsetof ( struct dhcphdr, options ) +
                 dhcppkt->options.used_len );
}

References offsetof, dhcp_packet::options, options, and dhcp_options::used_len.

Referenced by cachedhcp_record(), dhcp_tx(), and efi_pxe_fake().

dhcppkt_store()

int dhcppkt_store	(	struct dhcp_packet *	dhcppkt,
		unsigned int	tag,
		const void *	data,
		size_t	len
	)

Store value of DHCP packet setting.

Parameters

dhcppkt	DHCP packet
tag	Setting tag number
data	Setting data, or NULL to clear setting
len	Length of setting data

Return values

rc	Return status code

Definition at line 164 of file dhcppkt.c.

                                                   {
        struct dhcp_packet_field *field;
        void *field_data;

        /* If this is a special field, fill it in */
        if ( ( field = find_dhcp_packet_field ( tag ) ) != NULL ) {
                if ( len > field->len )
                        return -ENOSPC;
                field_data = dhcp_packet_field ( dhcppkt->dhcphdr, field );
                memset ( field_data, 0, field->len );
                memcpy ( dhcp_packet_field ( dhcppkt->dhcphdr, field ),
                         data, len );
                /* Erase any equivalent option from the options block */
                dhcpopt_store ( &dhcppkt->options, tag, NULL, 0 );
                return 0;
        }

        /* Otherwise, use the generic options block */
        return dhcpopt_store ( &dhcppkt->options, tag, data, len );
}

References data, dhcp_packet_field(), dhcp_packet::dhcphdr, dhcpopt_store(), ENOSPC, find_dhcp_packet_field(), dhcp_packet_field::len, len, memcpy(), memset(), NULL, dhcp_packet::options, and tag.

Referenced by copy_encap_settings(), dhcp_create_packet(), dhcp_create_request(), dhcp_proxy_tx(), dhcp_pxebs_tx(), dhcp_request_tx(), and dhcppkt_settings_store().

dhcppkt_fetch()

int dhcppkt_fetch	(	struct dhcp_packet *	dhcppkt,
		unsigned int	tag,
		void *	data,
		size_t	len
	)

Fetch value of DHCP packet setting.

Parameters

dhcppkt	DHCP packet
tag	Setting tag number
data	Buffer to fill with setting data
len	Length of buffer

Return values

len	Length of setting data, or negative error

Definition at line 195 of file dhcppkt.c.

                                             {
        struct dhcp_packet_field *field;
        void *field_data;
        size_t field_len = 0;
        
        /* Identify special field, if any */
        if ( ( field = find_dhcp_packet_field ( tag ) ) != NULL ) {
                field_data = dhcp_packet_field ( dhcppkt->dhcphdr, field );
                field_len = field->used_len ( field_data, field->len );
        }

        /* Return special field, if it exists and is populated */
        if ( field_len ) {
                if ( len > field_len )
                        len = field_len;
                memcpy ( data, field_data, len );
                return field_len;
        }

        /* Otherwise, use the generic options block */
        return dhcpopt_fetch ( &dhcppkt->options, tag, data, len );
}

References data, dhcp_packet_field(), dhcp_packet::dhcphdr, dhcpopt_fetch(), find_dhcp_packet_field(), dhcp_packet_field::len, len, memcpy(), NULL, dhcp_packet::options, tag, and dhcp_packet_field::used_len.

Referenced by dhcp_deliver(), dhcp_discovery_rx(), dhcp_has_pxeopts(), dhcp_pxebs_rx(), and dhcppkt_settings_fetch().

dhcppkt_init()

void dhcppkt_init	(	struct dhcp_packet *	dhcppkt,
		struct dhcphdr *	data,
		size_t	len
	)

Initialise DHCP packet.

Parameters

dhcppkt	DHCP packet structure to fill in
data	DHCP packet raw data
max_len	Length of raw data buffer

Initialise a DHCP packet structure from a data buffer containing a DHCP packet.

Definition at line 300 of file dhcppkt.c.

                                 {
        ref_init ( &dhcppkt->refcnt, NULL );
        dhcppkt->dhcphdr = data;
        dhcpopt_init ( &dhcppkt->options, &dhcppkt->dhcphdr->options,
                       ( len - offsetof ( struct dhcphdr, options ) ),
                       dhcpopt_no_realloc );
        settings_init ( &dhcppkt->settings, &dhcppkt_settings_operations,
                        &dhcppkt->refcnt, NULL );
}

References data, dhcp_packet::dhcphdr, dhcpopt_init(), dhcpopt_no_realloc(), dhcppkt_settings_operations, len, NULL, offsetof, dhcp_packet::options, options, dhcphdr::options, ref_init, dhcp_packet::refcnt, dhcp_packet::settings, and settings_init().

Referenced by cachedhcp_record(), dhcp_create_packet(), dhcp_deliver(), and efi_pxe_fake().