[ipv6] Add "ipv6" setting type

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

src/include/ipxe/settings.h

 extern struct setting_type setting_type_string __setting_type;
 extern struct setting_type setting_type_uristring __setting_type;
 extern struct setting_type setting_type_ipv4 __setting_type;
+extern struct setting_type setting_type_ipv6 __setting_type;
 extern struct setting_type setting_type_int8 __setting_type;
 extern struct setting_type setting_type_int16 __setting_type;
 extern struct setting_type setting_type_int32 __setting_type;

src/net/ipv6.c

 	.aton = ipv6_sock_aton,
 };
 
+/**
+ * Parse IPv6 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
+ */
+static int parse_ipv6_setting ( struct setting_type *type __unused,
+				const char *value, void *buf, size_t len ) {
+	struct in6_addr ipv6;
+	int rc;
+
+	/* Parse IPv6 address */
+	if ( ( rc = inet6_aton ( value, &ipv6 ) ) != 0 )
+		return rc;
+
+	/* Copy to buffer */
+	if ( len > sizeof ( ipv6 ) )
+		len = sizeof ( ipv6 );
+	memcpy ( buf, &ipv6, len );
+
+	return ( sizeof ( ipv6 ) );
+}
+
+/**
+ * Format IPv6 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
+ */
+static int format_ipv6_setting ( 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 ) )
+		return -EINVAL;
+	return snprintf ( buf, len, "%s", inet6_ntoa ( ipv6 ) );
+}
+
+/** An IPv6 address setting type */
+struct setting_type setting_type_ipv6 __setting_type = {
+	.name = "ipv6",
+	.parse = parse_ipv6_setting,
+	.format = format_ipv6_setting,
+};
+
 /**
  * Perform IPv6 stateless address autoconfiguration (SLAAC)
  *

src/tests/settings_test.c

 	.type = &setting_type_ipv4,
 };
 
+/** Test IPv6 address setting type */
+static struct setting test_ipv6_setting = {
+	.name = "test_ipv6",
+	.type = &setting_type_ipv6,
+};
+
 /** Test signed 8-bit integer setting type */
 static struct setting test_int8_setting = {
 	.name = "test_int8",
 	fetchf_ok ( &test_settings, &test_ipv4_setting,
 		    RAW ( 212, 13, 204, 60 ), "212.13.204.60" );
 
+	/* "ipv6" setting type */
+	storef_ok ( &test_settings, &test_ipv6_setting,
+		    "2001:ba8:0:1d4::6950:5845",
+		    RAW ( 0x20, 0x01, 0x0b, 0xa8, 0x00, 0x00, 0x01, 0xd4,
+			  0x00, 0x00, 0x00, 0x00, 0x69, 0x50, 0x58, 0x45 ) );
+	fetchf_ok ( &test_settings, &test_ipv6_setting,
+		    RAW ( 0xfe, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			  0x02, 0x0c, 0x29, 0xff, 0xfe, 0xc5, 0x39, 0xa1 ),
+		    "fe80::20c:29ff:fec5:39a1" );
+
 	/* Integer setting types (as formatted strings) */
 	storef_ok ( &test_settings, &test_int8_setting,
 		    "54", RAW ( 54 ) );