nvo.c File Reference

Non-volatile stored options. More...

#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ipxe/dhcp.h>
#include <ipxe/nvs.h>
#include <ipxe/nvo.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static unsigned int	nvo_checksum (struct nvo_block *nvo)
	Calculate checksum over non-volatile stored options. More...
static int	nvo_realloc (struct nvo_block *nvo, size_t len)
	Reallocate non-volatile stored options block. More...
static int	nvo_realloc_dhcpopt (struct dhcp_options *options, size_t len)
	Reallocate non-volatile stored options DHCP option block. More...
static int	nvo_load (struct nvo_block *nvo)
	Load non-volatile stored options from non-volatile storage device. More...
static int	nvo_save (struct nvo_block *nvo)
	Save non-volatile stored options back to non-volatile storage device. More...
int	nvo_applies (struct settings *settings __unused, const struct setting *setting)
	Check applicability of NVO setting. More...
static int	nvo_store (struct settings *settings, const struct setting *setting, const void *data, size_t len)
	Store value of NVO setting. More...
static int	nvo_fetch (struct settings *settings, struct setting *setting, void *data, size_t len)
	Fetch value of NVO setting. More...
void	nvo_init (struct nvo_block *nvo, struct nvs_device *nvs, size_t address, size_t len, int(*resize)(struct nvo_block *nvo, size_t len), struct refcnt *refcnt)
	Initialise non-volatile stored options. More...
int	register_nvo (struct nvo_block *nvo, struct settings *parent)
	Register non-volatile stored options. More...
void	unregister_nvo (struct nvo_block *nvo)
	Unregister non-volatile stored options. More...

Variables
static struct settings_operations	nvo_settings_operations
	NVO settings operations. More...

Detailed Description

Non-volatile stored options.

Definition in file nvo.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

nvo_checksum()

static unsigned int nvo_checksum ( struct nvo_block *  nvo )

static

Calculate checksum over non-volatile stored options.

Parameters

nvo	Non-volatile options block

Return values

sum

Checksum

Definition at line 46 of file nvo.c.

                                                           {
        uint8_t *data = nvo->data;
        uint8_t sum = 0;
        unsigned int i;

        for ( i = 0 ; i < nvo->len ; i++ ) {
                sum += *(data++);
        }
        return sum;
}

References data, nvo_block::data, and nvo_block::len.

Referenced by nvo_load(), and nvo_save().

nvo_realloc()

static int nvo_realloc ( struct nvo_block *  nvo, size_t  len  )

static

Reallocate non-volatile stored options block.

Parameters

nvo	Non-volatile options block
len	New length

Return values

rc	Return status code

Definition at line 64 of file nvo.c.

                                                             {
        void *new_data;

        /* Reallocate data */
        new_data = realloc ( nvo->data, len );
        if ( ! new_data ) {
                DBGC ( nvo, "NVO %p could not allocate %zd bytes\n",
                       nvo, len );
                return -ENOMEM;
        }
        nvo->data = new_data;
        nvo->len = len;

        /* Update DHCP option block */
        if ( len ) {
                nvo->dhcpopts.data = ( nvo->data + 1 /* checksum */ );
                nvo->dhcpopts.alloc_len = ( len - 1 /* checksum */ );
        } else {
                nvo->dhcpopts.data = NULL;
                nvo->dhcpopts.used_len = 0;
                nvo->dhcpopts.alloc_len = 0;
        }

        return 0;
}

References dhcp_options::alloc_len, dhcp_options::data, nvo_block::data, DBGC, nvo_block::dhcpopts, ENOMEM, len, nvo_block::len, NULL, realloc(), and dhcp_options::used_len.

Referenced by nvo_realloc_dhcpopt(), register_nvo(), and unregister_nvo().

nvo_realloc_dhcpopt()

static int nvo_realloc_dhcpopt ( struct dhcp_options *  options, size_t  len  )

static

Reallocate non-volatile stored options DHCP option block.

Parameters

options	DHCP option block
len	New length

Return values

rc	Return status code

Definition at line 97 of file nvo.c.

                                                                            {
        struct nvo_block *nvo =
                container_of ( options, struct nvo_block, dhcpopts );
        int rc;

        /* Refuse to reallocate if we have no way to resize the block */
        if ( ! nvo->resize )
                return dhcpopt_no_realloc ( options, len );

        /* Allow one byte for the checksum (if any data is present) */
        if ( len )
                len += 1;

        /* Resize underlying non-volatile options block */
        if ( ( rc = nvo->resize ( nvo, len ) ) != 0 ) {
                DBGC ( nvo, "NVO %p could not resize to %zd bytes: %s\n",
                       nvo, len, strerror ( rc ) );
                return rc;
        }

        /* Reallocate in-memory options block */
        if ( ( rc = nvo_realloc ( nvo, len ) ) != 0 )
                return rc;

        return 0;
}

References container_of, DBGC, dhcpopt_no_realloc(), nvo_block::dhcpopts, len, nvo_realloc(), options, rc, nvo_block::resize, and strerror().

Referenced by nvo_init().

nvo_load()

static int nvo_load ( struct nvo_block *  nvo )

static

Load non-volatile stored options from non-volatile storage device.

Parameters

nvo	Non-volatile options block

Return values

rc	Return status code

Definition at line 130 of file nvo.c.

                                              {
        uint8_t *options_data = nvo->dhcpopts.data;
        int rc;

        /* Skip reading zero-length NVO fields */
        if ( nvo->len == 0 ) {
                DBGC ( nvo, "NVO %p is empty; skipping load\n", nvo );
                return 0;
        }

        /* Read data */
        if ( ( rc = nvs_read ( nvo->nvs, nvo->address, nvo->data,
                               nvo->len ) ) != 0 ) {
                DBGC ( nvo, "NVO %p could not read %zd bytes at %#04x: %s\n",
                       nvo, nvo->len, nvo->address, strerror ( rc ) );
                return rc;
        }

        /* If checksum fails, or options data starts with a zero,
         * assume the whole block is invalid.  This should capture the
         * case of random initial contents.
         */
        if ( ( nvo_checksum ( nvo ) != 0 ) || ( options_data[0] == 0 ) ) {
                DBGC ( nvo, "NVO %p has checksum %02x and initial byte %02x; "
                       "assuming empty\n", nvo, nvo_checksum ( nvo ),
                       options_data[0] );
                memset ( nvo->data, 0, nvo->len );
        }

        /* Rescan DHCP option block */
        dhcpopt_update_used_len ( &nvo->dhcpopts );

        DBGC ( nvo, "NVO %p loaded from non-volatile storage\n", nvo );
        return 0;
}

References nvo_block::address, dhcp_options::data, nvo_block::data, DBGC, dhcpopt_update_used_len(), nvo_block::dhcpopts, nvo_block::len, memset(), nvo_checksum(), nvo_block::nvs, nvs_read(), rc, and strerror().

Referenced by register_nvo().

nvo_save()

static int nvo_save ( struct nvo_block *  nvo )

static

Save non-volatile stored options back to non-volatile storage device.

Parameters

nvo	Non-volatile options block

Return values

rc	Return status code

Definition at line 172 of file nvo.c.

                                              {
        uint8_t *checksum = nvo->data;
        int rc;

        /* Recalculate checksum, if applicable */
        if ( nvo->len > 0 )
                *checksum -= nvo_checksum ( nvo );

        /* Write data */
        if ( ( rc = nvs_write ( nvo->nvs, nvo->address, nvo->data,
                                nvo->len ) ) != 0 ) {
                DBGC ( nvo, "NVO %p could not write %zd bytes at %#04x: %s\n",
                       nvo, nvo->len, nvo->address, strerror ( rc ) );
                return rc;
        }

        DBGC ( nvo, "NVO %p saved to non-volatile storage\n", nvo );
        return 0;
}

References nvo_block::address, checksum, nvo_block::data, DBGC, nvo_block::len, nvo_checksum(), nvo_block::nvs, nvs_write(), rc, and strerror().

Referenced by nvo_store().

nvo_applies()

int nvo_applies	(	struct settings *settings	__unused,
		const struct setting *	setting
	)

Check applicability of NVO setting.

Parameters

settings	Settings block
setting	Setting

Return values

applies

Setting applies within this settings block

Definition at line 199 of file nvo.c.

                                                  {

        return ( ( setting->scope == NULL ) &&
                 dhcpopt_applies ( setting->tag ) );
}

References dhcpopt_applies(), NULL, setting::scope, and setting::tag.

Referenced by efi_snp_hii_setting_applies().

nvo_store()

static int nvo_store ( struct settings *  settings, const struct setting *  setting, const void *  data, size_t  len  )

static

Store value of NVO setting.

Parameters

settings	Settings block
setting	Setting to store
data	Setting data, or NULL to clear setting
len	Length of setting data

Return values

rc	Return status code

Definition at line 215 of file nvo.c.

                                                      {
        struct nvo_block *nvo =
                container_of ( settings, struct nvo_block, settings );
        int rc;

        /* Update stored options */
        if ( ( rc = dhcpopt_store ( &nvo->dhcpopts, setting->tag,
                                    data, len ) ) != 0 ) {
                DBGC ( nvo, "NVO %p could not store %zd bytes: %s\n",
                       nvo, len, strerror ( rc ) );
                return rc;
        }

        /* Save updated options to NVS */
        if ( ( rc = nvo_save ( nvo ) ) != 0 )
                return rc;

        return 0;
}

References container_of, data, DBGC, dhcpopt_store(), nvo_block::dhcpopts, len, nvo_save(), rc, strerror(), and setting::tag.

nvo_fetch()

static int nvo_fetch ( struct settings *  settings, struct setting *  setting, void *  data, size_t  len  )

static

Fetch value of NVO setting.

Parameters

settings	Settings block
setting	Setting to fetch
data	Buffer to fill with setting data
len	Length of buffer

Return values

len	Length of setting data, or negative error

The actual length of the setting will be returned even if the buffer was too small.

Definition at line 248 of file nvo.c.

                                                {
        struct nvo_block *nvo =
                container_of ( settings, struct nvo_block, settings );

        return dhcpopt_fetch ( &nvo->dhcpopts, setting->tag, data, len );
}

References container_of, data, dhcpopt_fetch(), nvo_block::dhcpopts, len, and setting::tag.

nvo_init()

void nvo_init	(	struct nvo_block *	nvo,
		struct nvs_device *	nvs,
		size_t	address,
		size_t	len,
		int(*)(struct nvo_block *nvo, size_t len)	resize,
		struct refcnt *	refcnt
	)

Initialise non-volatile stored options.

Parameters

nvo	Non-volatile options block
nvs	Underlying non-volatile storage device
address	Address within NVS device
len	Length of non-volatile options data
resize	Resize method
refcnt	Containing object reference counter, or NULL

Definition at line 273 of file nvo.c.

                                        {
        nvo->nvs = nvs;
        nvo->address = address;
        nvo->len = len;
        nvo->resize = resize;
        dhcpopt_init ( &nvo->dhcpopts, NULL, 0, nvo_realloc_dhcpopt );
        settings_init ( &nvo->settings, &nvo_settings_operations,
                        refcnt, NULL );
}

References address, nvo_block::address, dhcpopt_init(), nvo_block::dhcpopts, len, nvo_block::len, NULL, nvo_realloc_dhcpopt(), nvo_settings_operations, nvo_block::nvs, nvo_block::resize, nvo_block::settings, and settings_init().

Referenced by falcon_probe_spi(), myri10ge_nv_init(), nvs_vpd_nvo_init(), and realtek_init_eeprom().

register_nvo()

int register_nvo	(	struct nvo_block *	nvo,
		struct settings *	parent
	)

Register non-volatile stored options.

Parameters

nvo	Non-volatile options block
parent	Parent settings block, or NULL

Return values

rc	Return status code

Definition at line 293 of file nvo.c.

                                                                    {
        int rc;

        /* Allocate memory for options */
        if ( ( rc = nvo_realloc ( nvo, nvo->len ) ) != 0 )
                goto err_realloc;

        /* Read data from NVS */
        if ( ( rc = nvo_load ( nvo ) ) != 0 )
                goto err_load;

        /* Register settings */
        if ( ( rc = register_settings ( &nvo->settings, parent,
                                        NVO_SETTINGS_NAME ) ) != 0 )
                goto err_register;

        DBGC ( nvo, "NVO %p registered\n", nvo );
        return 0;
        
 err_register:
 err_load:
        nvo_realloc ( nvo, 0 );
 err_realloc:
        return rc;
}

References DBGC, nvo_block::len, nvo_load(), nvo_realloc(), NVO_SETTINGS_NAME, rc, register_settings(), and nvo_block::settings.

Referenced by efab_probe(), hermon_register_netdev(), myri10ge_nv_init(), and realtek_probe().

unregister_nvo()

void unregister_nvo

(

struct nvo_block *

nvo

)

Unregister non-volatile stored options.

Parameters

nvo	Non-volatile options block

Definition at line 324 of file nvo.c.

                                              {
        unregister_settings ( &nvo->settings );
        nvo_realloc ( nvo, 0 );
        DBGC ( nvo, "NVO %p unregistered\n", nvo );
}

References DBGC, nvo_realloc(), nvo_block::settings, and unregister_settings().

Referenced by efab_remove(), hermon_register_netdev(), hermon_unregister_netdev(), myri10ge_nv_fini(), and realtek_remove().

Variable Documentation

nvo_settings_operations

struct settings_operations nvo_settings_operations

static

Initial value:

= {
        .applies = nvo_applies,
        .store = nvo_store,
        .fetch = nvo_fetch,
}

NVO settings operations.

Definition at line 257 of file nvo.c.

Referenced by nvo_init().