host: Add function to create two hosts from a range definition

src/libstrongswan/networking/host.c

@@ -525,6 +525,34 @@ host_t *host_create_from_chunk(int family, chunk_t address, u_int16_t port)
 	return &this->public;
 }
 
+/*
+ * Described in header.
+ */
+bool host_create_from_range(char *string, host_t **from, host_t **to)
+{
+	char *pos;
+
+	pos = strchr(string, '-');
+	if (!pos)
+	{
+		return FALSE;
+	}
+	*to = host_create_from_string(pos + 1, 0);
+	if (!*to)
+	{
+		return FALSE;
+	}
+	pos = strndup(string, pos - string);
+	*from = host_create_from_string_and_family(pos, (*to)->get_family(*to), 0);
+	free(pos);
+	if (!*from)
+	{
+		(*to)->destroy(*to);
+		return FALSE;
+	}
+	return TRUE;
+}
+
 /*
  * Described in header.
  */

src/libstrongswan/networking/host.h

@@ -180,6 +180,19 @@ host_t *host_create_from_chunk(int family, chunk_t address, u_int16_t port);
  */
 host_t *host_create_from_sockaddr(sockaddr_t *sockaddr);
 
+/**
+ * Parse a range definition (1.2.3.0-1.2.3.5), return the two hosts.
+ *
+ * The two hosts are not ordered, from is simply the first, to is the second,
+ * from is not necessarily smaller.
+ *
+ * @param string		string to parse
+ * @param from			returns the first address (out)
+ * @param to			returns the second address (out)
+ * @return				TRUE if parsed successfully, FALSE otherwise
+ */
+bool host_create_from_range(char *string, host_t **from, host_t **to);
+
 /**
  * Create a host from a CIDR subnet definition (1.2.3.0/24), return bits.
  *