VFS_CHECKEXP(9)        FreeBSD Kernel Developer's Manual       VFS_CHECKEXP(9)

NAME
     VFS_CHECKEXP - check if a file system is exported to a client

SYNOPSIS
     #include <sys/param.h>
     #include <sys/mount.h>

     int
     VFS_CHECKEXP(struct mount *mp, struct sockaddr *nam, uint64_t *exflagsp,
         struct ucred **credanonp, int *numsecflavor, int *secflavors);

DESCRIPTION
     The VFS_CHECKEXP() macro is used by the NFS server to check if a mount
     point is exported to a client.

     The arguments it expects are:

     mp             The mount point to be checked.

     nam            An mbuf containing the network address of the client.

     exflagsp       Return parameter for the export flags for this client.

     credanonp      Return parameter for the anonymous credentials for this
                    client.

     numsecflavors  Return value for the number of security flavors for this
                    client.

     secflavors     Must be an array of size MAXSECFLAVORS, in which the
                    security flavors for this client are returned.

     The VFS_CHECKEXP() macro should be called on a file system's mount
     structure to determine if it is exported to a client whose address is
     contained in nam.

     It is called in the NFS server once a vnode for a file handle has been
     acquired, in order to determine what access the client is allowed on the
     file system the vnode resides in.  For NFSv4, it is also called whenever
     the lookup operation crosses a server file system mount point, to update
     the access information.

     The operation is file system specific, but is normally handled by the
     default ``vfs_stdcheckexp''.

RETURN VALUES
     The export flags, anonymous credentials and security flavors specific to
     the client will be returned in *exflagsp, *credanonp, *numsecflavors and
     *secflavors.

SEE ALSO
     VFS(9), VFS_FHTOVP(9), vnode(9), VOP_VPTOFH(9)

AUTHORS
     This manual page was written by Alfred Perlstein.

FreeBSD 13.1-RELEASE-p6          June 17, 2020         FreeBSD 13.1-RELEASE-p6