WebNFS is an extension to the

Network File System Network File System (NFS) is a distributed file system protocol originally developed by Sun Microsystems (Sun) in 1984, allowing a user on a client computer to access files over a computer network much like local storage is accessed. NFS, li ...

(NFS) for allowing clients to access a

file system In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one lar ...

over the internet using a simplified, firewall-friendly protocol. WebNFS was developed to give

Java applet Java applets were small applications written in the Java programming language, or another programming language that compiles to Java bytecode, and delivered to users in the form of Java bytecode. The user launched the Java applet from a ...

s and other internet enabled applications a way of accessing filesystem services over the internet. While NFS provides applications on

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

with full filesystem semantics, not all of these might be needed in a distributed, read-only web environment. Conversely, access restrictions—such as requiring the use of restricted ports for originating requests—normally used in closed environments are not usually applicable in public distributed environments. WebNFS makes use of a well known port (port 2049 on both UDP and TCP) thus avoiding the overhead and unpredictability of using the ONC RPC

portmap The port mapper (''rpc.portmap'' or just ''portmap'', or ''rpcbind'') is an Open Network Computing Remote Procedure Call (ONC RPC) service that runs on network nodes that provide other ONC RPC services. Version 2 of the port mapper protocol maps O ...

protocol. WebNFS adds public filehandles and multicomponent lookups to the NFS protocol. WebNFS is specified by a number of RFCs: * : WebNFS Client * : WebNFS Server * : NFS URL Scheme * : Security negotiation for WebNFS In 2007,

Sun Microsystems Sun Microsystems, Inc. (Sun for short) was an American technology company that sold computers, computer components, software, and information technology services and created the Java programming language, the Solaris operating system, ZFS, ...

opensourced its WebNFS implementation. The name has since changed to YANFS (Yet Another NFS) to reflect the expanded scope of the project to include a server side implementation.

Legacy

While WebNFS itself did not gain much traction, several important WebNFS features later became part of NFSv4 – such as the usage of port 2049, or the concept of a fixed "root filehandle" (which evolved from WebNFS public filehandles and allows exported filesystems to be accessed without needing the MOUNT protocol to learn their individual root handles first), both together allowing NFSv4 to function without the portmap service.

References

{{Reflist

External links

YANFS website
Internet protocols Network file systems Internet Protocol based network software Unix file system-related software Application layer protocols