[Settings] Introduce settings applicators.

Convert DHCP option applicators in dns.c and iscsi.c to settings
applicators.

Kill off DHCP option applicators.

src/core/settings.c

@@ -37,15 +37,21 @@
 
 /** Registered setting types */
 static struct setting_type setting_types[0]
-__table_start ( struct setting_type, setting_types );
+	__table_start ( struct setting_type, setting_types );
 static struct setting_type setting_types_end[0]
-__table_end ( struct setting_type, setting_types );
+	__table_end ( struct setting_type, setting_types );
 
 /** Registered named settings */
 static struct named_setting named_settings[0]
-__table_start ( struct named_setting, named_settings );
+	__table_start ( struct named_setting, named_settings );
 static struct named_setting named_settings_end[0]
-__table_end ( struct named_setting, named_settings );
+	__table_end ( struct named_setting, named_settings );
+
+/** Registered settings applicators */
+static struct settings_applicator settings_applicators[0]
+	__table_start ( struct settings_applicator, settings_applicators );
+static struct settings_applicator settings_applicators_end[0]
+	__table_end ( struct settings_applicator, settings_applicators );
 
 /**
  * Obtain printable version of a settings tag number
@@ -94,10 +100,6 @@ int simple_settings_fetch ( struct settings *settings, unsigned int tag,
 	return ( len ? len : 8 );
 }
 
-// Dummy routine just for testing
-static void apply_settings ( void ) {
-}
-
 /** Simple settings operations */
 struct settings_operations simple_settings_operations = {
 	.store = simple_settings_store,
@@ -113,6 +115,66 @@ struct settings settings_root = {
 	.op = &simple_settings_operations,
 };
 
+/**
+ * Apply all settings
+ *
+ * @ret rc		Return status code
+ */
+static int apply_settings ( void ) {
+	struct settings_applicator *applicator;
+	int rc;
+
+	/* Call all settings applicators */
+	for ( applicator = settings_applicators ;
+	      applicator < settings_applicators_end ; applicator++ ) {
+		if ( ( rc = applicator->apply() ) != 0 ) {
+			DBG ( "Could not apply settings using applicator "
+			      "%p: %s\n", applicator, strerror ( rc ) );
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * Reprioritise settings
+ *
+ * @v settings		Settings block
+ *
+ * Reorders the settings block amongst its siblings according to its
+ * priority.
+ */
+static void reprioritise_settings ( struct settings *settings ) {
+	struct settings *parent = settings->parent;
+	long priority;
+	struct settings *tmp;
+	long tmp_priority;
+
+	/* Stop when we reach the top of the tree */
+	if ( ! parent )
+		return;
+
+	/* Read priority, if present */
+	priority = 0;
+	fetch_int_setting ( settings, DHCP_EB_PRIORITY, &priority );
+
+	/* Remove from siblings list */
+	list_del ( &settings->siblings );
+
+	/* Reinsert after any existing blocks which have a higher priority */
+	list_for_each_entry ( tmp, &parent->children, siblings ) {
+		tmp_priority = 0;
+		fetch_int_setting ( tmp, DHCP_EB_PRIORITY, &tmp_priority );
+		if ( priority > tmp_priority )
+			break;
+	}
+	list_add_tail ( &settings->siblings, &tmp->siblings );
+
+	/* Recurse up the tree */
+	reprioritise_settings ( parent );
+}
+
 /**
  * Register settings block
  *
@@ -134,6 +196,9 @@ int register_settings ( struct settings *settings, struct settings *parent ) {
 	list_add_tail ( &settings->siblings, &parent->children );
 	DBGC ( settings, "Settings %p registered\n", settings );
 
+	/* Fix up settings priority */
+	reprioritise_settings ( settings );
+
 	/* Apply potentially-updated settings */
 	apply_settings();
 
@@ -206,6 +271,34 @@ struct settings * find_settings ( const char *name ) {
  ******************************************************************************
  */
 
+/**
+ * Store value of setting
+ *
+ * @v settings		Settings block
+ * @v tag		Setting tag number
+ * @v data		Setting data, or NULL to clear setting
+ * @v len		Length of setting data
+ * @ret rc		Return status code
+ */
+int store_setting ( struct settings *settings, unsigned int tag,
+		    const void *data, size_t len ) {
+	int rc;
+
+	/* Store setting */
+	if ( ( rc = settings->op->store ( settings, tag, data, len ) ) != 0 )
+		return rc;
+
+	/* Reprioritise settings if necessary */
+	if ( tag == DHCP_EB_PRIORITY )
+		reprioritise_settings ( settings );
+
+	/* Apply potentially-updated setting */
+	if ( ( rc = apply_settings() ) != 0 )
+		return rc;
+
+	return 0;
+}
+
 /**
  * Fetch value of setting
  *
@@ -288,7 +381,7 @@ int fetch_ipv4_setting ( struct settings *settings, unsigned int tag,
 	len = fetch_setting ( settings, tag, inp, sizeof ( *inp ) );
 	if ( len < 0 )
 		return len;
-	if ( len != sizeof ( *inp ) )
+	if ( len < ( int ) sizeof ( *inp ) )
 		return -ERANGE;
 	return len;
 }

src/include/gpxe/dhcp.h

@@ -489,23 +489,6 @@ struct dhcp_packet {
 	struct dhcp_option_block options;
 };
 
-/** A DHCP option applicator */
-struct dhcp_option_applicator {
-	/** DHCP option tag */
-	unsigned int tag;
-	/** Applicator
-	 *
-	 * @v tag	DHCP option tag
-	 * @v option	DHCP option
-	 * @ret rc	Return status code
-	 */
-	int ( * apply ) ( unsigned int tag, struct dhcp_option *option );
-};
-
-/** Declare a DHCP option applicator */
-#define __dhcp_applicator \
-	__table ( struct dhcp_option_applicator, dhcp_applicators, 01 )
-
 /**
  * Get reference to DHCP options block
  *

src/include/gpxe/settings.h

@@ -122,6 +122,22 @@ struct named_setting {
 /** Declare a configuration setting */
 #define	__named_setting __table ( struct named_setting, named_settings, 01 )
 
+/**
+ * A settings applicator
+ *
+ */
+struct settings_applicator {
+	/** Apply updated settings
+	 *
+	 * @ret rc		Return status code
+	 */
+	int ( * apply ) ( void );
+};
+
+/** Declare a settings applicator */
+#define __settings_applicator \
+	__table ( struct settings_applicator, settings_applicators, 01 )
+
 extern int simple_settings_store ( struct settings *settings, unsigned int tag,
 				   const void *data, size_t len );
 extern int simple_settings_fetch ( struct settings *settings, unsigned int tag,
@@ -131,6 +147,8 @@ extern struct settings_operations simple_settings_operations;
 extern int register_settings ( struct settings *settings,
 			       struct settings *parent );
 extern void unregister_settings ( struct settings *settings );
+extern int store_setting ( struct settings *settings, unsigned int tag,
+			   const void *data, size_t len );
 extern int fetch_setting ( struct settings *settings, unsigned int tag,
 			   void *data, size_t len );
 extern int fetch_setting_len ( struct settings *settings, unsigned int tag );
@@ -179,20 +197,6 @@ static inline void settings_init ( struct settings *settings,
 	settings->name = name;
 }
 
-/**
- * Store value of setting
- *
- * @v settings		Settings block
- * @v tag		Setting tag number
- * @v data		Setting data, or NULL to clear setting
- * @v len		Length of setting data
- * @ret rc		Return status code
- */
-static inline int store_setting ( struct settings *settings, unsigned int tag,
-				  const void *data, size_t len ) {
-	return settings->op->store ( settings, tag, data, len );
-}
-
 /**
  * Delete setting
  *

src/net/dhcpopts.c

@@ -37,12 +37,6 @@
 /** List of registered DHCP option blocks */
 LIST_HEAD ( dhcp_option_blocks );
 
-/** Registered DHCP option applicators */
-static struct dhcp_option_applicator dhcp_option_applicators[0]
-	__table_start ( struct dhcp_option_applicator, dhcp_applicators );
-static struct dhcp_option_applicator dhcp_option_applicators_end[0]
-	__table_end ( struct dhcp_option_applicator, dhcp_applicators );
-
 /**
  * Obtain printable version of a DHCP option tag
  *
@@ -578,13 +572,9 @@ void delete_dhcp_option ( struct dhcp_option_block *options,
  * @ret rc		Return status code
  */
 int apply_dhcp_options ( struct dhcp_option_block *options ) {
-	struct dhcp_option_applicator *applicator;
-	struct dhcp_option *option;
 	struct in_addr tftp_server;
 	struct uri *uri;
 	char uri_string[32];
-	unsigned int tag;
-	int rc;
 
 	/* Set current working URI based on TFTP server */
 	find_dhcp_ipv4_option ( options, DHCP_EB_SIADDR, &tftp_server );
@@ -596,20 +586,6 @@ int apply_dhcp_options ( struct dhcp_option_block *options ) {
 	churi ( uri );
 	uri_put ( uri );
 
-	/* Call all registered DHCP option applicators */
-	for ( applicator = dhcp_option_applicators ;
-	      applicator < dhcp_option_applicators_end ; applicator++ ) {
-		tag = applicator->tag;
-		option = find_dhcp_option ( options, tag );
-		if ( ! option )
-			continue;
-		if ( ( rc = applicator->apply ( tag, option ) ) != 0 ) {
-			DBG ( "Could not apply DHCP option %s: %s\n",
-			      dhcp_tag_name ( tag ), strerror ( rc ) );
-			return rc;
-		}
-	}
-
 	return 0;
 }
 

src/net/tcp/iscsi.c

@@ -31,7 +31,7 @@
 #include <gpxe/process.h>
 #include <gpxe/uaccess.h>
 #include <gpxe/tcpip.h>
-#include <gpxe/dhcp.h>
+#include <gpxe/settings.h>
 #include <gpxe/features.h>
 #include <gpxe/iscsi.h>
 
@@ -1591,80 +1591,109 @@ int iscsi_attach ( struct scsi_device *scsi, const char *root_path ) {
 
 /****************************************************************************
  *
- * DHCP option applicators
+ * Settings applicators
  *
  */
 
-/**
- * Apply DHCP iSCSI option
- *
- * @v tag		DHCP option tag
- * @v option		DHCP option
- * @ret rc		Return status code
- */
-static int apply_dhcp_iscsi_string ( unsigned int tag,
-				     struct dhcp_option *option ) {
-	char *prefix = "";
-	size_t prefix_len;
-	size_t len;
+/** An iSCSI string setting */
+struct iscsi_string_setting {
+	/** Setting tag number */
+	unsigned int tag;
+	/** String to update */
 	char **string;
-	char *p;
-
-	/* Identify string and prefix */
-	switch ( tag ) {
-	case DHCP_ISCSI_INITIATOR_IQN:
-		string = &iscsi_explicit_initiator_iqn;
-		break;
-	case DHCP_EB_USERNAME:
-		string = &iscsi_username;
-		break;
-	case DHCP_EB_PASSWORD:
-		string = &iscsi_password;
-		break;
-	case DHCP_HOST_NAME:
-		string = &iscsi_default_initiator_iqn;
-		prefix = "iqn.2000-09.org.etherboot:";
-		break;
-	default:
-		assert ( 0 );
-		return -EINVAL;
-	}
-
-	/* Free old string */
-	free ( *string );
-	*string = NULL;
-
-	/* Allocate and fill new string */
-	prefix_len = strlen ( prefix );
-	len = ( prefix_len + option->len + 1 );
-	p = *string = malloc ( len );
-	if ( ! p )
-		return -ENOMEM;
-	strcpy ( p, prefix );
-	dhcp_snprintf ( ( p + prefix_len ), ( len - prefix_len ), option );
-	return 0;
-}
+	/** String prefix */
+	const char *prefix;
+};
 
-/** DHCP iSCSI option applicators */
-struct dhcp_option_applicator dhcp_iscsi_applicators[] __dhcp_applicator = {
+/** iSCSI string settings */
+static struct iscsi_string_setting iscsi_string_settings[] = {
 	{
 		.tag = DHCP_ISCSI_INITIATOR_IQN,
-		.apply = apply_dhcp_iscsi_string,
+		.string = &iscsi_explicit_initiator_iqn,
+		.prefix = "",
 	},
 	{
 		.tag = DHCP_EB_USERNAME,
-		.apply = apply_dhcp_iscsi_string,
+		.string = &iscsi_username,
+		.prefix = "",
 	},
 	{
 		.tag = DHCP_EB_PASSWORD,
-		.apply = apply_dhcp_iscsi_string,
+		.string = &iscsi_password,
+		.prefix = "",
 	},
 	{
 		.tag = DHCP_HOST_NAME,
-		.apply = apply_dhcp_iscsi_string,
+		.string = &iscsi_default_initiator_iqn,
+		.prefix = "iqn.2000-09.org.etherboot:",
 	},
 };
 
+/**
+ * Apply iSCSI setting
+ *
+ * @v setting		iSCSI string setting
+ * @ret rc		Return status code
+ */
+static int apply_iscsi_string_setting ( struct iscsi_string_setting *setting ){
+	size_t prefix_len;
+	int setting_len;
+	size_t len;
+	int check_len;
+	char *p;
+
+	/* Free old string */
+	free ( *setting->string );
+	*setting->string = NULL;
+
+	/* Allocate new string */
+	prefix_len = strlen ( setting->prefix );
+	setting_len = fetch_setting_len ( NULL, setting->tag );
+	if ( setting_len < 0 )
+		return setting_len;
+	len = ( prefix_len + setting_len + 1 );
+	p = *setting->string = malloc ( len );
+	if ( ! p )
+		return -ENOMEM;
+
+	/* Fill new string */
+	strcpy ( p, setting->prefix );
+	check_len = fetch_string_setting ( NULL, setting->tag,
+					   ( p + prefix_len ),
+					   ( len - prefix_len ) );
+	assert ( check_len == setting_len );
+
+	return 0;
+}
+
+/**
+ * Apply iSCSI settings
+ *
+ * @ret rc		Return status code
+ */
+static int apply_iscsi_settings ( void ) {
+	struct iscsi_string_setting *setting;
+	unsigned int i;
+	int rc;
+
+	for ( i = 0 ; i < ( sizeof ( iscsi_string_settings ) /
+			    sizeof ( iscsi_string_settings[0] ) ) ; i++ ) {
+		setting = &iscsi_string_settings[i];
+		if ( ( rc = apply_iscsi_string_setting ( setting ) ) != 0 ) {
+			DBG ( "iSCSI could not apply setting %d\n",
+			      setting->tag );
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
+/** iSCSI settings applicator */
+struct settings_applicator iscsi_settings_applicator __settings_applicator = {
+	.apply = apply_iscsi_settings,
+};
+
 /****************************************************************************
  *
  * Initiator name

src/net/udp/dns.c

@@ -30,7 +30,7 @@
 #include <gpxe/resolv.h>
 #include <gpxe/retry.h>
 #include <gpxe/tcpip.h>
-#include <gpxe/dhcp.h>
+#include <gpxe/settings.h>
 #include <gpxe/features.h>
 #include <gpxe/dns.h>
 
@@ -507,27 +507,26 @@ struct resolver dns_resolver __resolver ( RESOLV_NORMAL ) = {
 };
 
 /**
- * Apply DHCP nameserver option
+ * Apply nameserver setting
  *
- * @v tag		DHCP option tag
- * @v option		DHCP option
+ * @ret rc		Return status code
  */
-static int apply_dhcp_nameserver ( unsigned int tag __unused,
-				   struct dhcp_option *option ) {
-	struct sockaddr_in *sin_nameserver;
-
-	sin_nameserver = ( struct sockaddr_in * ) &nameserver;
-	sin_nameserver->sin_family = AF_INET;
-	dhcp_ipv4_option ( option, &sin_nameserver->sin_addr );
-
-	DBG ( "DNS using nameserver %s\n",
-	      inet_ntoa ( sin_nameserver->sin_addr ) );
+static int apply_nameserver_setting ( void ) {
+	struct sockaddr_in *sin_nameserver =
+		( struct sockaddr_in * ) &nameserver;
+	int len;
+
+	if ( ( len = fetch_ipv4_setting ( NULL, DHCP_DNS_SERVERS,
+					  &sin_nameserver->sin_addr ) ) >= 0 ){
+		sin_nameserver->sin_family = AF_INET;
+		DBG ( "DNS using nameserver %s\n",
+		      inet_ntoa ( sin_nameserver->sin_addr ) );
+	}
 
 	return 0;
 }
 
-/** DHCP nameserver applicator */
-struct dhcp_option_applicator dhcp_nameserver_applicator __dhcp_applicator = {
-	.tag = DHCP_DNS_SERVERS,
-	.apply = apply_dhcp_nameserver,
+/** Nameserver setting applicator */
+struct settings_applicator nameserver_applicator __settings_applicator = {
+	.apply = apply_nameserver_setting,
 };