dhcppkt.h File Reference

DHCP packets. More...

#include <gpxe/dhcp.h>
#include <gpxe/dhcpopts.h>
#include <gpxe/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)
static struct dhcp_packet *	dhcppkt_get (struct dhcp_packet *dhcppkt)
	Increment reference count on DHCP packet.
static void	dhcppkt_put (struct dhcp_packet *dhcppkt)
	Decrement reference count on DHCP packet.
int	dhcppkt_store (struct dhcp_packet *dhcppkt, unsigned int tag, const void *data, size_t len)
	Store value of DHCP packet setting.
int	dhcppkt_fetch (struct dhcp_packet *dhcppkt, unsigned int tag, void *data, size_t len)
	Fetch value of DHCP packet setting.
void	dhcppkt_init (struct dhcp_packet *dhcppkt, struct dhcphdr *data, size_t len)
	Initialise DHCP packet.

---

Detailed Description

DHCP packets.

Definition in file dhcppkt.h.

---

Function Documentation

FILE_LICENCE

(

GPL2_OR_LATER

)

static struct dhcp_packet* dhcppkt_get

(

struct dhcp_packet *

dhcppkt

)

[static, read]

Increment reference count on DHCP packet.

Parameters:

dhcppkt

DHCP packet

Return values:

dhcppkt

DHCP packet

Definition at line 42 of file dhcppkt.h.

References ref_get().

Referenced by dhcp_rx_offer().

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

static void dhcppkt_put

(

struct dhcp_packet *

dhcppkt

)

[inline, static]

Decrement reference count on DHCP packet.

Parameters:

dhcppkt

DHCP packet

Definition at line 53 of file dhcppkt.h.

References ref_put().

Referenced by dhcp_deliver_iob(), dhcp_free(), dhcp_rx_offer(), and store_cached_dhcpack().

                                            {
        ref_put ( &dhcppkt->refcnt );
}

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 146 of file dhcppkt.c.

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

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

                                                   {
        struct dhcp_packet_field *field;
        void *field_data;
        int rc;

        /* 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 */
        rc = dhcpopt_store ( &dhcppkt->options, tag, data, len );

        /* Update our used-length field */
        dhcppkt->len = ( offsetof ( struct dhcphdr, options ) +
                         dhcppkt->options.len );

        return rc;
}

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 184 of file dhcppkt.c.

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

Referenced by dhcp_deliver_iob(), dhcp_pxebs_rx(), dhcp_rx_offer(), and dhcppkt_settings_fetch().

                                             {
        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 );
}

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 272 of file dhcppkt.c.

References DHCP_SETTINGS_NAME, dhcp_packet::dhcphdr, dhcpopt_init(), dhcp_options::len, dhcp_packet::len, dhcp_packet::max_len, offsetof, options, dhcphdr::options, dhcp_packet::options, dhcp_packet::refcnt, dhcp_packet::settings, and settings_init().

Referenced by dhcp_create_packet(), dhcp_deliver_iob(), and store_cached_dhcpack().

                                 {
        dhcppkt->dhcphdr = data;
        dhcppkt->max_len = len;
        dhcpopt_init ( &dhcppkt->options, &dhcppkt->dhcphdr->options,
                       ( len - offsetof ( struct dhcphdr, options ) ) );
        dhcppkt->len = ( offsetof ( struct dhcphdr, options ) +
                         dhcppkt->options.len );
        settings_init ( &dhcppkt->settings,
                        &dhcppkt_settings_operations, &dhcppkt->refcnt,
                        DHCP_SETTINGS_NAME, 0 );
}