[settings] Allow for IPv6 setting types in non-IPv6 builds

Allow for the existence of references to IPv6 setting types without
dragging in the whole IPv6 stack, by placing the definition of
setting_type_ipv6 in core/settings.c and providing weak stub methods
for parse_ipv6_setting() and format_ipv6_setting().

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/settings.c

@@ -28,6 +28,8 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <errno.h>
 #include <assert.h>
 #include <ipxe/in.h>
+#include <ipxe/ip.h>
+#include <ipxe/ipv6.h>
 #include <ipxe/vsprintf.h>
 #include <ipxe/dhcp.h>
 #include <ipxe/uuid.h>
@@ -1648,7 +1650,7 @@ const struct setting_type setting_type_uristring __setting_type = {
 };
 
 /**
- * Parse IPv4 address setting value
+ * Parse IPv4 address setting value (when IPv4 support is not present)
  *
  * @v type		Setting type
  * @v value		Formatted setting value
@@ -1656,24 +1658,14 @@ const struct setting_type setting_type_uristring __setting_type = {
  * @v len		Length of buffer
  * @ret len		Length of raw value, or negative error
  */
-static int parse_ipv4_setting ( const struct setting_type *type __unused,
-				const char *value, void *buf, size_t len ) {
-	struct in_addr ipv4;
-
-	/* Parse IPv4 address */
-	if ( inet_aton ( value, &ipv4 ) == 0 )
-		return -EINVAL;
-
-	/* Copy to buffer */
-	if ( len > sizeof ( ipv4 ) )
-		len = sizeof ( ipv4 );
-	memcpy ( buf, &ipv4, len );
-
-	return ( sizeof ( ipv4 ) );
+__weak int parse_ipv4_setting ( const struct setting_type *type __unused,
+				const char *value __unused, void *buf __unused,
+				size_t len __unused ) {
+	return -ENOTSUP;
 }
 
 /**
- * Format IPv4 address setting value
+ * Format IPv4 address setting value (when IPv4 support is not present)
  *
  * @v type		Setting type
  * @v raw		Raw setting value
@@ -1682,14 +1674,11 @@ static int parse_ipv4_setting ( const struct setting_type *type __unused,
  * @v len		Length of buffer
  * @ret len		Length of formatted value, or negative error
  */
-static int format_ipv4_setting ( const struct setting_type *type __unused,
-				 const void *raw, size_t raw_len, char *buf,
-				 size_t len ) {
-	const struct in_addr *ipv4 = raw;
-
-	if ( raw_len < sizeof ( *ipv4 ) )
-		return -EINVAL;
-	return snprintf ( buf, len, "%s", inet_ntoa ( *ipv4 ) );
+__weak int format_ipv4_setting ( const struct setting_type *type __unused,
+				 const void *raw __unused,
+				 size_t raw_len __unused, char *buf __unused,
+				 size_t len __unused ) {
+	return -ENOTSUP;
 }
 
 /** An IPv4 address setting type */
@@ -1699,6 +1688,48 @@ const struct setting_type setting_type_ipv4 __setting_type = {
 	.format = format_ipv4_setting,
 };
 
+/**
+ * Parse IPv6 address setting value (when IPv6 support is not present)
+ *
+ * @v type		Setting type
+ * @v value		Formatted setting value
+ * @v buf		Buffer to contain raw value
+ * @v len		Length of buffer
+ * @ret len		Length of raw value, or negative error
+ */
+__weak int parse_ipv6_setting ( const struct setting_type *type __unused,
+				const char *value __unused, void *buf __unused,
+				size_t len __unused ) {
+	return -ENOTSUP;
+}
+
+/**
+ * Format IPv6 address setting value (when IPv6 support is not present)
+ *
+ * @v type		Setting type
+ * @v raw		Raw setting value
+ * @v raw_len		Length of raw setting value
+ * @v buf		Buffer to contain formatted value
+ * @v len		Length of buffer
+ * @ret len		Length of formatted value, or negative error
+ */
+__weak int format_ipv6_setting ( const struct setting_type *type __unused,
+				 const void *raw __unused,
+				 size_t raw_len __unused, char *buf __unused,
+				 size_t len __unused ) {
+	return -ENOTSUP;
+}
+
+/** An IPv6 address setting type */
+const struct setting_type setting_type_ipv6 __setting_type = {
+	.name = "ipv6",
+	.parse = parse_ipv6_setting,
+	.format = format_ipv6_setting,
+};
+
+/** IPv6 settings scope */
+const struct settings_scope ipv6_scope;
+
 /**
  * Integer setting type indices
  *

src/include/ipxe/ip.h

@@ -75,5 +75,10 @@ extern struct list_head ipv4_miniroutes;
 extern struct net_protocol ipv4_protocol __net_protocol;
 
 extern int ipv4_has_any_addr ( struct net_device *netdev );
+extern int parse_ipv4_setting ( const struct setting_type *type,
+				const char *value, void *buf, size_t len );
+extern int format_ipv4_setting ( const struct setting_type *type,
+				 const void *raw, size_t raw_len, char *buf,
+				 size_t len );
 
 #endif /* _IPXE_IP_H */

src/include/ipxe/ipv6.h

@@ -247,5 +247,10 @@ extern int ipv6_set_prefix ( struct net_device *netdev, struct in6_addr *prefix,
 			     unsigned int prefix_len, struct in6_addr *router );
 extern int ipv6_set_address ( struct net_device *netdev,
 			      struct in6_addr *address );
+extern int parse_ipv6_setting ( const struct setting_type *type,
+				const char *value, void *buf, size_t len );
+extern int format_ipv6_setting ( const struct setting_type *type,
+				 const void *raw, size_t raw_len, char *buf,
+				 size_t len );
 
 #endif /* _IPXE_IPV6_H */

src/include/ipxe/settings.h

@@ -62,16 +62,18 @@ struct setting {
 #define SETTING_NETDEV_EXTRA	02 /**< Network device additional settings */
 #define SETTING_IPv4		03 /**< IPv4 settings */
 #define SETTING_IPv4_EXTRA	04 /**< IPv4 additional settings */
-#define SETTING_BOOT		05 /**< Generic boot settings */
-#define SETTING_BOOT_EXTRA	06 /**< Generic boot additional settings */
-#define SETTING_SANBOOT		07 /**< SAN boot settings */
-#define SETTING_SANBOOT_EXTRA	08 /**< SAN boot additional settings */
-#define SETTING_HOST		09 /**< Host identity settings */
-#define SETTING_HOST_EXTRA	10 /**< Host identity additional settings */
-#define SETTING_AUTH		11 /**< Authentication settings */
-#define SETTING_AUTH_EXTRA	12 /**< Authentication additional settings */
-#define SETTING_CRYPTO		13 /**< Cryptography settings */
-#define SETTING_MISC		14 /**< Miscellaneous settings */
+#define SETTING_IPv6		05 /**< IPv6 settings */
+#define SETTING_IPv6_EXTRA	06 /**< IPv6 additional settings */
+#define SETTING_BOOT		07 /**< Generic boot settings */
+#define SETTING_BOOT_EXTRA	08 /**< Generic boot additional settings */
+#define SETTING_SANBOOT		09 /**< SAN boot settings */
+#define SETTING_SANBOOT_EXTRA	10 /**< SAN boot additional settings */
+#define SETTING_HOST		11 /**< Host identity settings */
+#define SETTING_HOST_EXTRA	12 /**< Host identity additional settings */
+#define SETTING_AUTH		13 /**< Authentication settings */
+#define SETTING_AUTH_EXTRA	14 /**< Authentication additional settings */
+#define SETTING_CRYPTO		15 /**< Cryptography settings */
+#define SETTING_MISC		16 /**< Miscellaneous settings */
 
 /** @} */
 
@@ -277,6 +279,9 @@ struct builtin_setting {
 /** Built-in setting scope */
 extern const struct settings_scope builtin_scope;
 
+/** IPv6 setting scope */
+extern const struct settings_scope ipv6_scope;
+
 /**
  * A generic settings block
  *

src/net/ipv4.c

@@ -590,6 +590,51 @@ struct sockaddr_converter ipv4_sockaddr_converter __sockaddr_converter = {
  ******************************************************************************
  */
 
+/**
+ * Parse IPv4 address setting value
+ *
+ * @v type		Setting type
+ * @v value		Formatted setting value
+ * @v buf		Buffer to contain raw value
+ * @v len		Length of buffer
+ * @ret len		Length of raw value, or negative error
+ */
+int parse_ipv4_setting ( const struct setting_type *type __unused,
+			 const char *value, void *buf, size_t len ) {
+	struct in_addr ipv4;
+
+	/* Parse IPv4 address */
+	if ( inet_aton ( value, &ipv4 ) == 0 )
+		return -EINVAL;
+
+	/* Copy to buffer */
+	if ( len > sizeof ( ipv4 ) )
+		len = sizeof ( ipv4 );
+	memcpy ( buf, &ipv4, len );
+
+	return ( sizeof ( ipv4 ) );
+}
+
+/**
+ * Format IPv4 address setting value
+ *
+ * @v type		Setting type
+ * @v raw		Raw setting value
+ * @v raw_len		Length of raw setting value
+ * @v buf		Buffer to contain formatted value
+ * @v len		Length of buffer
+ * @ret len		Length of formatted value, or negative error
+ */
+int format_ipv4_setting ( const struct setting_type *type __unused,
+			  const void *raw, size_t raw_len, char *buf,
+			  size_t len ) {
+	const struct in_addr *ipv4 = raw;
+
+	if ( raw_len < sizeof ( *ipv4 ) )
+		return -EINVAL;
+	return snprintf ( buf, len, "%s", inet_ntoa ( *ipv4 ) );
+}
+
 /** IPv4 address setting */
 const struct setting ip_setting __setting ( SETTING_IPv4 ) = {
 	.name = "ip",

src/net/ipv6.c

@@ -954,8 +954,8 @@ struct sockaddr_converter ipv6_sockaddr_converter __sockaddr_converter = {
  * @v len		Length of buffer
  * @ret len		Length of raw value, or negative error
  */
-static int parse_ipv6_setting ( const struct setting_type *type __unused,
-				const char *value, void *buf, size_t len ) {
+int parse_ipv6_setting ( const struct setting_type *type __unused,
+			 const char *value, void *buf, size_t len ) {
 	struct in6_addr ipv6;
 	int rc;
 
@@ -981,9 +981,9 @@ static int parse_ipv6_setting ( const struct setting_type *type __unused,
  * @v len		Length of buffer
  * @ret len		Length of formatted value, or negative error
  */
-static int format_ipv6_setting ( const struct setting_type *type __unused,
-				 const void *raw, size_t raw_len, char *buf,
-				 size_t len ) {
+int format_ipv6_setting ( const struct setting_type *type __unused,
+			  const void *raw, size_t raw_len, char *buf,
+			  size_t len ) {
 	const struct in6_addr *ipv6 = raw;
 
 	if ( raw_len < sizeof ( *ipv6 ) )
@@ -991,13 +991,6 @@ static int format_ipv6_setting ( const struct setting_type *type __unused,
 	return snprintf ( buf, len, "%s", inet6_ntoa ( ipv6 ) );
 }
 
-/** An IPv6 address setting type */
-const struct setting_type setting_type_ipv6 __setting_type = {
-	.name = "ipv6",
-	.parse = parse_ipv6_setting,
-	.format = format_ipv6_setting,
-};
-
 /**
  * Create IPv6 network device
  *

src/net/udp/dhcpv6.c

@@ -255,9 +255,6 @@ static int dhcpv6_iaaddr ( struct dhcpv6_option_list *options, uint32_t iaid,
  *
  */
 
-/** DHCPv6 settings scope */
-static const struct settings_scope dhcpv6_settings_scope;
-
 /** A DHCPv6 settings block */
 struct dhcpv6_settings {
 	/** Reference count */
@@ -278,7 +275,7 @@ struct dhcpv6_settings {
 static int dhcpv6_applies ( struct settings *settings __unused,
 			    const struct setting *setting ) {
 
-	return ( setting->scope == &dhcpv6_settings_scope );
+	return ( setting->scope == &ipv6_scope );
 }
 
 /**
@@ -339,7 +336,7 @@ static int dhcpv6_register ( struct dhcpv6_option_list *options,
 	}
 	ref_init ( &dhcpv6set->refcnt, NULL );
 	settings_init ( &dhcpv6set->settings, &dhcpv6_settings_operations,
-			&dhcpv6set->refcnt, &dhcpv6_settings_scope );
+			&dhcpv6set->refcnt, &ipv6_scope );
 	data = ( ( ( void * ) dhcpv6set ) + sizeof ( *dhcpv6set ) );
 	len = options->len;
 	memcpy ( data, options->data, len );