1 files changed, 324 insertions, 0 deletions
diff --git a/roms/ipxe/src/core/nvo.c b/roms/ipxe/src/core/nvo.c
new file mode 100644
index 00000000..e135d2b4
--- /dev/null
+++ b/roms/ipxe/src/core/nvo.c
@@ -0,0 +1,324 @@
+/*
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <ipxe/dhcp.h>
+#include <ipxe/nvs.h>
+#include <ipxe/nvo.h>
+
+/** @file
+ *
+ * Non-volatile stored options
+ *
+ */
+
+/**
+ * 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->data;
+	uint8_t sum = 0;
+	unsigned int i;
+
+	for ( i = 0 ; i < nvo->len ; i++ ) {
+		sum += *(data++);
+	}
+	return sum;
+}
+
+/**
+ * Reallocate non-volatile stored options block
+ *
+ * @v nvo		Non-volatile options block
+ * @v len		New length
+ * @ret rc		Return status code
+ */
+static int nvo_realloc ( struct nvo_block *nvo, size_t len ) {
+	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;
+}
+
+/**
+ * Reallocate non-volatile stored options DHCP option block
+ *
+ * @v options		DHCP option block
+ * @v len		New length
+ * @ret rc		Return status code
+ */
+static int nvo_realloc_dhcpopt ( struct dhcp_options *options, size_t len ) {
+	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;
+}
+
+/**
+ * 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 ) {
+	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;
+}
+
+/**
+ * Save non-volatile stored options back to non-volatile storage device
+ *
+ * @v nvo		Non-volatile options block
+ * @ret rc		Return status code
+ */
+static int nvo_save ( struct nvo_block *nvo ) {
+	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;
+}
+
+/**
+ * Check applicability of NVO setting
+ *
+ * @v settings		Settings block
+ * @v setting		Setting
+ * @ret applies		Setting applies within this settings block
+ */
+int nvo_applies ( struct settings *settings __unused,
+		  const struct setting *setting ) {
+
+	return ( ( setting->scope == NULL ) &&
+		 dhcpopt_applies ( setting->tag ) );
+}
+
+/**
+ * Store value of NVO setting
+ *
+ * @v settings		Settings block
+ * @v setting		Setting to store
+ * @v data		Setting data, or NULL to clear setting
+ * @v len		Length of setting data
+ * @ret rc		Return status code
+ */
+static int nvo_store ( struct settings *settings, const struct setting *setting,
+		       const void *data, size_t len ) {
+	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;
+}
+
+/**
+ * Fetch value of NVO setting
+ *
+ * @v settings		Settings block
+ * @v setting		Setting to fetch
+ * @v data		Buffer to fill with setting data
+ * @v len		Length of buffer
+ * @ret len		Length of setting data, or negative error
+ *
+ * The actual length of the setting will be returned even if
+ * the buffer was too small.
+ */
+static int nvo_fetch ( struct settings *settings, struct setting *setting,
+		       void *data, size_t len ) {
+	struct nvo_block *nvo =
+		container_of ( settings, struct nvo_block, settings );
+
+	return dhcpopt_fetch ( &nvo->dhcpopts, setting->tag, data, len );
+}
+
+/** NVO settings operations */
+static struct settings_operations nvo_settings_operations = {
+	.applies = nvo_applies,
+	.store = nvo_store,
+	.fetch = nvo_fetch,
+};
+
+/**
+ * Initialise non-volatile stored options
+ *
+ * @v nvo		Non-volatile options block
+ * @v nvs		Underlying non-volatile storage device
+ * @v address		Address within NVS device
+ * @v len		Length of non-volatile options data
+ * @v resize		Resize method
+ * @v refcnt		Containing object reference counter, or NULL
+ */
+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 ) {
+	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 );
+}
+
+/**
+ * Register non-volatile stored options
+ *
+ * @v nvo		Non-volatile options block
+ * @v parent		Parent settings block, or NULL
+ * @ret rc		Return status code
+ */
+int register_nvo ( struct nvo_block *nvo, struct settings *parent ) {
+	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;
+}
+
+/**
+ * Unregister non-volatile stored options
+ *
+ * @v nvo		Non-volatile options block
+ */
+void unregister_nvo ( struct nvo_block *nvo ) {
+	unregister_settings ( &nvo->settings );
+	nvo_realloc ( nvo, 0 );
+	DBGC ( nvo, "NVO %p unregistered\n", nvo );
+}