NFSSVC(2) BSD System Calls Manual NFSSVC(2)NAMEnfssvc — NFS services
SYNOPSIS
#include <unistd.h>
#include <nfs/nfs.h>
int
nfssvc(int flags, void *argstructp);
DESCRIPTION
The nfssvc() function is used by the NFS server daemon to pass informa‐
tion into and out of the kernel and also to enter the kernel as a server
daemon. The flags argument consists of several bits that show what
action is to be taken once in the kernel and the argstructp points to any
corresponding data that the action may require.
nfssvc() is called with the flag NFSSVC_NFSD and a NULL argstructp to
enter the kernel as an nfsd(8) daemon. The NFSSVC_NFSD action normally
does not return until the NFS server is stopped.
The nfsd(8) server daemon calls nfssvc() with the flag NFSSVC_ADDSOCK and
a pointer to a
struct nfsd_args {
int sock; /* Socket to serve */
caddr_t name; /* Client address for connection based sockets */
int namelen; /* Length of name */
};
to pass a server side NFS socket into the kernel for servicing by the
nfsd(8) daemons.
The nfsd(8) server daemon calls nfssvc() with the flag NFSSVC_EXPORT and
a pointer to a
struct nfs_export_args {
uint32_t nxa_fsid; /* export FS ID */
uint32_t nxa_expid; /* export ID */
char *nxa_fspath; /* export FS path */
char *nxa_exppath; /* export sub-path */
uint32_t nxa_flags; /* export arg flags */
uint32_t nxa_netcount; /* #entries in ex_nets array */
struct nfs_export_net_args *nxa_nets; /* array of net args */
};
to pass exported file system information into the kernel.
RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, -1 is
returned the global variable errno is set to specify the error.
ERRORS
[EPERM] The caller is not the super-user.
[EINVAL] The action specified by the flags argument was not
valid.
[EFAULT] argstructp points to an invalid address.
[ENOMEM] A memory allocation failure prevented the action from
completing.
[EEXIST] An attempt was made to add a UDP socket via the
NFSSVC_ADDSOCK action, but the UDP socket has already
been added.
SEE ALSOnfsd(8)HISTORY
The nfssvc function first appeared in 4.4BSD.
BUGS
The nfssvc system call is designed specifically for the NFS server dae‐
mons and as such is specific to their requirements. Several fields of
the argument structures are assumed to be valid, such that nfssvc must be
used with extreme care.
BSD January 9, 2007 BSD
