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- /*
- * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or any later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
- #include <stdint.h>
- #include <string.h>
- #include <gpxe/dhcp.h>
- #include <gpxe/nvs.h>
- #include <gpxe/nvo.h>
-
- /** @file
- *
- * Non-volatile stored options
- *
- */
-
- #warning "Temporary hack"
- struct nvo_block *ugly_nvo_hack = NULL;
-
- /**
- * Calculate checksum over non-volatile stored options
- *
- * @v nvo Non-volatile options block
- * @ret sum Checksum
- */
- static unsigned int nvo_checksum ( struct nvo_block *nvo ) {
- uint8_t *data = nvo->options->data;
- uint8_t sum = 0;
- unsigned int i;
-
- for ( i = 0 ; i < nvo->total_len ; i++ ) {
- sum += *(data++);
- }
- return sum;
- }
-
- /**
- * Load non-volatile stored options from non-volatile storage device
- *
- * @v nvo Non-volatile options block
- * @ret rc Return status code
- */
- static int nvo_load ( struct nvo_block *nvo ) {
- void *data = nvo->options->data;
- struct nvo_fragment *fragment;
- int rc;
-
- /* Read data a fragment at a time */
- for ( fragment = nvo->fragments ; fragment->len ; fragment++ ) {
- if ( ( rc = nvs_read ( nvo->nvs, fragment->address,
- data, fragment->len ) ) != 0 ) {
- DBG ( "NVO %p could not read %zd bytes at %#04x\n",
- nvo, fragment->len, fragment->address );
- return rc;
- }
- data += fragment->len;
- }
-
- DBG ( "NVO %p loaded from non-volatile storage\n", nvo );
- return 0;
- }
-
- /**
- * Save non-volatile stored options back to non-volatile storage device
- *
- * @v nvo Non-volatile options block
- * @ret rc Return status code
- */
- int nvo_save ( struct nvo_block *nvo ) {
- void *data = nvo->options->data;
- uint8_t *checksum = ( data + nvo->total_len - 1 );
- struct nvo_fragment *fragment;
- int rc;
-
- /* Recalculate checksum */
- *checksum -= nvo_checksum ( nvo );
-
- /* Write data a fragment at a time */
- for ( fragment = nvo->fragments ; fragment->len ; fragment++ ) {
- if ( ( rc = nvs_write ( nvo->nvs, fragment->address,
- data, fragment->len ) ) != 0 ) {
- DBG ( "NVO %p could not write %zd bytes at %#04x\n",
- nvo, fragment->len, fragment->address );
- return rc;
- }
- data += fragment->len;
- }
-
- DBG ( "NVO %p saved to non-volatile storage\n", nvo );
- return 0;
- }
-
- /**
- * Parse stored options
- *
- * @v nvo Non-volatile options block
- *
- * Verifies that the options data is valid, and configures the DHCP
- * options block. If the data is not valid, it is replaced with an
- * empty options block.
- */
- static void nvo_init_dhcp ( struct nvo_block *nvo ) {
- struct dhcp_option_block *options = nvo->options;
- struct dhcp_option *option;
-
- /* Steal one byte for the checksum */
- options->max_len = ( nvo->total_len - 1 );
-
- /* Verify checksum over whole block */
- if ( nvo_checksum ( nvo ) != 0 ) {
- DBG ( "NVO %p has bad checksum %02x; assuming empty\n",
- nvo, nvo_checksum ( nvo ) );
- goto empty;
- }
-
- /* Check that we don't just have a block full of zeroes */
- option = options->data;
- if ( option->tag == DHCP_PAD ) {
- DBG ( "NVO %p has bad start; assuming empty\n", nvo );
- goto empty;
- }
-
- /* Search for the DHCP_END tag */
- options->len = options->max_len;
- option = find_dhcp_option ( options, DHCP_END );
- if ( ! option ) {
- DBG ( "NVO %p has no end tag; assuming empty\n", nvo );
- goto empty;
- }
-
- /* Set correct length of DHCP options */
- options->len = ( ( void * ) option - options->data + 1 );
- DBG ( "NVO %p contains %zd bytes of options (maximum %zd)\n",
- nvo, options->len, options->max_len );
- return;
-
- empty:
- /* No options found; initialise an empty options block */
- option = options->data;
- option->tag = DHCP_END;
- options->len = 1;
- return;
- }
-
- /**
- * Register non-volatile stored options
- *
- * @v nvo Non-volatile options block
- * @ret rc Return status code
- */
- int nvo_register ( struct nvo_block *nvo ) {
- struct nvo_fragment *fragment = nvo->fragments;
- int rc;
-
- /* Calculate total length of all fragments */
- nvo->total_len = 0;
- for ( fragment = nvo->fragments ; fragment->len ; fragment++ ) {
- nvo->total_len += fragment->len;
- }
-
- /* Allocate memory for options and read in from NVS */
- nvo->options = alloc_dhcp_options ( nvo->total_len );
- if ( ! nvo->options ) {
- DBG ( "NVO %p could not allocate %zd bytes\n",
- nvo, nvo->total_len );
- rc = -ENOMEM;
- goto err;
- }
- if ( ( rc = nvo_load ( nvo ) ) != 0 )
- goto err;
-
- /* Verify and register options */
- nvo_init_dhcp ( nvo );
- register_dhcp_options ( nvo->options );
-
- ugly_nvo_hack = nvo;
-
- DBG ( "NVO %p registered\n", nvo );
- return 0;
-
- err:
- free_dhcp_options ( nvo->options );
- nvo->options = NULL;
- return rc;
- }
-
- /**
- * Unregister non-volatile stored options
- *
- * @v nvo Non-volatile options block
- */
- void nvo_unregister ( struct nvo_block *nvo ) {
-
- if ( nvo->options ) {
- unregister_dhcp_options ( nvo->options );
- free_dhcp_options ( nvo->options );
- nvo->options = NULL;
- }
-
- DBG ( "NVO %p unregistered\n", nvo );
-
- ugly_nvo_hack = NULL;
- }
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