man(1) Manual page archive


     ATTACH(5)                                               ATTACH(5)

     NAME
          attach, session, nop - messages to initiate activity

     SYNOPSIS
          Tnop      tag[2]
          Rnop      tag[2]

          Tsession  tag[2]
          Rsession  tag[2]

          Tattach   tag[2] fid[2] uid[28] aname[28] auth[28]
          Rattach   tag[2] fid[2] qid[8]

     DESCRIPTION
          The nop request does nothing overt but may be used to syn-
          chronize the channel between two service hosts initially.

          The session request is used to initialize a connection
          between a client and a server.  All outstanding I/O on the
          connection is aborted.  The set of messages between session
          requests is called a session. Tags and fids must be unique
          per session.

          The tag should be NOTAG (value 0xFFFF) for a nop or session
          message.

          The attach message serves as a fresh introduction from a
          user on the client machine to a server.  The message identi-
          fies the user (uid) and may select the file tree to access
          (aname).  The auth argument contains authorization data
          derived from the chal field of an auth message; see auth(5)
          and auth(6).

          As a result of the attach transaction, the client will have
          a connection to the root directory of the desired file tree,
          represented by fid. An error is returned if fid is already
          in use.  The server's idea of the root of the file tree is
          represented by the returned qid.

     ENTRY POINTS
          An attach transaction will be generated for kernel devices
          (see intro(3)) when a system call evaluates a file name
          beginning with `#'.  Pipe(2) generates an attach on the ker-
          nel device pipe(3). Mount (see bind(2)) generates auth and
          attach messages to the remote file server.  When the kernel
          boots, an attach is made to the root device, root(3), and
          then an auth and an attach are made to the requested file
          server machine.

     SEE ALSO

     ATTACH(5)                                               ATTACH(5)

          auth(5), auth(6)