Calls used by nfsd(8)

On the server side, nfssvc() is called with the flag NFSSVC_NFSD and a pointer to a

struct nfsd_srvargs {
	struct nfsd	*nsd_nfsd;	/* Pointer to in kernel nfsd struct */
	uid_t		nsd_uid;	/* Effective uid mapped to cred */
	u_long		nsd_haddr;	/* Ip address of client */
	struct ucred	nsd_cr;		/* Cred. uid maps to */
	int		nsd_authlen;	/* Length of auth string (ret) */
	char		*nsd_authstr;	/* Auth string (ret) */
};

to enter the kernel as an nfsd(8) daemon. Whenever an nfsd(8) daemon receives a Kerberos authentication ticket, it will return from nfssvc() with errno set to ENEEDAUTH. The nfsd(8) will attempt to authenticate the ticket and generate a set of credentials on the server for the “user id” specified in the field nsd_uid. This is done by first authenticating the Kerberos ticket and then mapping the Kerberos principal to a local name and getting a set of credentials for that user via getpwnam(3) and getgrouplist(3). If successful, the nfsd(8) will call nfssvc() with the NFSSVC_NFSD and NFSSVC_AUTHIN flags set to pass the credential mapping in nsd_cr into the kernel to be cached on the server socket for that client. If the authentication failed, nfsd(8) calls nfssvc() with the flags NFSSVC_NFSD and NFSSVC_AUTHINFAIL to denote an authentication failure.

The master 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.

Calls used by mountd(8)

The mountd(8) server daemon calls nfssvc() with the flag NFSSVC_REPLACEEXPORTSLIST and a pointer to a struct mountd_exports_list object to atomically replace the exports lists of a specific file system. This structure has the following fields:

const char *mel_path

Path to the file system that will have its exports list replaced by the one described in the other fields.

size_t mel_nexports

Number of valid entries in the mel_export field. If zero, the exports list will be cleared for the given file system.

struct export_args mel_export[AF_MAX]

Set of exports to be used for the given file system.