Add uri_base setting for getting the host:port portion of a URI.

This is useful for fetching relative URLs based on the DHCP server
provided file URI.

src/core/settings.c

@@ -697,6 +697,10 @@ int fetch_setting ( struct settings *settings, const struct setting *setting,
 		if ( ( ret = settings->op->fetch ( settings, &tmp,
 						   data, len ) ) >= 0 ) {
 
+			/* If incoming setting has a type, copy it over in
+			 * case it was overridden. */
+			if ( setting->type )
+				tmp.type = setting->type;
 			/* Default to string type, if not yet specified */
 			if ( ! tmp.type )
 				tmp.type = &setting_type_string;
@@ -1714,6 +1718,48 @@ const struct setting_type setting_type_uristring __setting_type = {
 	.format = format_uristring_setting,
 };
 
+/**
+ * Format a URI without the path, query, and fragment portions.
+ *
+ * @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_uribase_setting ( const struct setting_type *type __unused,
+				    const void *raw, size_t raw_len,
+				    char *buf, size_t len ) {
+	char *raw_str;
+	struct uri *base_uri;
+	size_t ret;
+	raw_str = strndup((const char*)raw, raw_len);
+	if (!raw_str) {
+		return -ENOMEM;
+	}
+	base_uri = parse_uri(raw_str);
+	if (!base_uri) {
+		ret = -ENOMEM;
+		goto  err_uri_parse;
+	}
+	base_uri->path = NULL;
+	base_uri->query = NULL;
+	base_uri->fragment = NULL;
+	ret = format_uri(base_uri, buf, len);
+	uri_put(base_uri);
+err_uri_parse:
+	free(raw_str);
+	return ret;
+}
+
+/** A setting to strip path, query, and fragment from a URI */
+const struct setting_type setting_type_uribase __setting_type = {
+	.name = "uribase",
+	.format = format_uribase_setting,
+};
+
+
 /**
  * Parse IPv4 address setting value (when IPv4 support is not present)
  *

src/include/ipxe/settings.h

@@ -413,6 +413,7 @@ extern char * expand_settings ( const char *string );
 
 extern const struct setting_type setting_type_string __setting_type;
 extern const struct setting_type setting_type_uristring __setting_type;
+extern const struct setting_type setting_type_uribase __setting_type;
 extern const struct setting_type setting_type_ipv4 __setting_type;
 extern const struct setting_type setting_type_ipv6 __setting_type;
 extern const struct setting_type setting_type_int8 __setting_type;

src/tests/settings_test.c

@@ -172,6 +172,12 @@ static struct setting test_uristring_setting = {
 	.type = &setting_type_uristring,
 };
 
+/** Test URI base setting */
+static struct setting test_uribase_setting = {
+	.name = "test_uribase",
+	.type = &setting_type_uribase,
+};
+
 /** Test IPv4 address setting type */
 static struct setting test_ipv4_setting = {
 	.name = "test_ipv4",
@@ -281,6 +287,13 @@ static void settings_test_exec ( void ) {
 		    RAW ( 0, ' ', '%', '/', '#', ':', '@', '?', '=', '&' ),
 		    "%00%20%25%2F%23%3A%40%3F%3D%26" );
 
+        /* "uribase" setting type (no store capability) */
+	fetchf_ok ( &test_settings, &test_uribase_setting,
+		    RAW ( 'h', 't', 't', 'p', ':', '/', '/', 's', 'o', 'm', 'e',
+                          '.', 's', 'e', 'r', 'v', 'e', 'r', ':', '1', '2', '3',
+                          '4', '/', 'p', 'a', 't', 'h', '?', 'q', '#', 'f'),
+                    "http://some.server:1234" );
+
 	/* "ipv4" setting type */
 	storef_ok ( &test_settings, &test_ipv4_setting, "192.168.0.1",
 		    RAW ( 192, 168, 0, 1 ) );