dhcpopts.h File Reference

DHCP options. More...

#include <stdint.h>

Go to the source code of this file.

Data Structures
struct	dhcp_options
	A DHCP options block. More...
Functions
	FILE_LICENCE (GPL2_OR_LATER)
int	dhcpopt_store (struct dhcp_options *options, unsigned int tag, const void *data, size_t len)
	Store value of DHCP option setting.
int	dhcpopt_extensible_store (struct dhcp_options *options, unsigned int tag, const void *data, size_t len)
	Store value of DHCP option setting, extending options block if necessary.
int	dhcpopt_fetch (struct dhcp_options *options, unsigned int tag, void *data, size_t len)
	Fetch value of DHCP option setting.
void	dhcpopt_init (struct dhcp_options *options, void *data, size_t max_len)
	Initialise prepopulated block of DHCP options.

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Detailed Description

DHCP options.

Definition in file dhcpopts.h.

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Function Documentation

FILE_LICENCE

(

GPL2_OR_LATER

)

int dhcpopt_store	(	struct dhcp_options *	options,
		unsigned int	tag,
		const void *	data,
		size_t	len
	)

Store value of DHCP option setting.

Parameters:

	options	DHCP option block
	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 340 of file dhcpopts.c.

References offset, and set_dhcp_option().

Referenced by dhcppkt_store(), and nvo_store().

                                                   {
        int offset;

        offset = set_dhcp_option ( options, tag, data, len, 0 );
        if ( offset < 0 )
                return offset;
        return 0;
}

int dhcpopt_extensible_store	(	struct dhcp_options *	options,
		unsigned int	tag,
		const void *	data,
		size_t	len
	)

Store value of DHCP option setting, extending options block if necessary.

Parameters:

	options	DHCP option block
	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 359 of file dhcpopts.c.

References offset, and set_dhcp_option().

                                                              {
        int offset;

        offset = set_dhcp_option ( options, tag, data, len, 1 );
        if ( offset < 0 )
                return offset;
        return 0;
}

int dhcpopt_fetch	(	struct dhcp_options *	options,
		unsigned int	tag,
		void *	data,
		size_t	len
	)

Fetch value of DHCP option setting.

Parameters:

	options	DHCP option block
	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 378 of file dhcpopts.c.

References dhcp_option::data, dhcp_option(), find_dhcp_option_with_encap(), dhcp_option::len, memcpy, NULL, and offset.

Referenced by dhcppkt_fetch(), and nvo_fetch().

                                             {
        int offset;
        struct dhcp_option *option;
        size_t option_len;

        offset = find_dhcp_option_with_encap ( options, tag, NULL );
        if ( offset < 0 )
                return offset;

        option = dhcp_option ( options, offset );
        option_len = option->len;
        if ( len > option_len )
                len = option_len;
        memcpy ( data, option->data, len );

        return option_len;
}

void dhcpopt_init	(	struct dhcp_options *	options,
		void *	data,
		size_t	max_len
	)

Initialise prepopulated block of DHCP options.

Parameters:

	options	Uninitialised DHCP option block
	data	Memory for DHCP option data
	max_len	Length of memory for DHCP option data

The memory content must already be filled with valid DHCP options. A zeroed block counts as a block of valid DHCP options.

Definition at line 435 of file dhcpopts.c.

References dhcp_options::data, DBGC, dhcpopt_update_len(), dhcp_options::len, and dhcp_options::max_len.

Referenced by dhcppkt_init(), and nvo_init_dhcpopts().

                                     {

        /* Fill in fields */
        options->data = data;
        options->max_len = max_len;

        /* Update length */
        dhcpopt_update_len ( options );

        DBGC ( options, "DHCPOPT %p created (data %p len %#zx max_len %#zx)\n",
               options, options->data, options->len, options->max_len );
}