NFSSVC(2) OpenBSD Programmer's 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 NFS daemons to pass information into 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 one of two structures
depending on which bits are set in flags.
To enter an nfsd(8) daemon into the kernel, nfssvc() is called with the
flag NFSSVC_NFSD and a pointer to a structure:
struct nfsd_srvargs {
struct nfsd *nsd_nfsd; /* Pointer to in kernel nfsd struct */
uid_t nsd_uid; /* Effective uid mapped to cred */
u_int32_t nsd_haddr; /* IP address of client */
struct ucred nsd_cr; /* Cred. uid maps to */
int nsd_authlen; /* Length of auth string (ret) */
u_char *nsd_authstr; /* Auth string (ret) */
int nsd_verflen; /* and the verifier */
u_char *nsd_verfstr;
struct timeval nsd_timestamp; /* timestamp from verifier */
u_int32_t nsd_ttl; /* credential ttl (sec) */
NFSKERBKEY_T nsd_key; /* Session key */
};
To add further sockets for processing by the nfsd(8) server daemons the
master nfsd(8) daemon calls nfssvc() with the flag NFSSVC_ADDSOCK and a
pointer to a structure:
struct nfsd_args {
int sock; /* Socket to serve */
caddr_t name; /* Client address for connection based sockets */
int namelen; /* Length of name */
};
RETURN VALUES
Normally nfssvc does not return unless the server is terminated by a
signal when a value of 0 is returned. Otherwise, -1 is returned and the
global variable errno is set to specify the error.
ERRORS
[EPERM] The caller is not the superuser.
[EINVAL] The flag argument consisted of incompatible or otherwise
unsupported bits.
SEE ALSOmount_nfs(8), nfsd(8), sysctl(8)HISTORY
The nfssvc function first appeared in 4.4BSD.
BUGS
The nfssvc system call is designed specifically for the NFS support
daemons and as such is specific to their requirements. Several fields of
the argument structures are assumed to be valid and sometimes to be
unchanged from a previous call, such that nfssvc() must be used with
extreme care.
OpenBSD 4.9 May 31, 2007 OpenBSD 4.9
