xref: /dragonfly/lib/libc/sys/nfssvc.2 (revision 279dd846)
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28.\"	@(#)nfssvc.2	8.1 (Berkeley) 6/9/93
29.\" $FreeBSD: src/lib/libc/sys/nfssvc.2,v 1.8.2.6 2002/12/29 16:35:34 schweikh Exp $
30.\" $DragonFly: src/lib/libc/sys/nfssvc.2,v 1.2 2003/06/17 04:26:47 dillon Exp $
31.\"
32.Dd June 9, 1993
33.Dt NFSSVC 2
34.Os
35.Sh NAME
36.Nm nfssvc
37.Nd NFS services
38.Sh LIBRARY
39.Lb libc
40.Sh SYNOPSIS
41.In sys/param.h
42.In sys/mount.h
43.In sys/time.h
44.In nfs/rpcv2.h
45.In nfs/nfs.h
46.In unistd.h
47.Ft int
48.Fn nfssvc "int flags" "void *argstructp"
49.Sh DESCRIPTION
50The
51.Fn nfssvc
52function is used by the NFS daemons to pass information into and out
53of the kernel and also to enter the kernel as a server daemon.
54The
55.Fa flags
56argument consists of several bits that show what action is to be taken
57once in the kernel and the
58.Fa argstructp
59points to one of three structures depending on which bits are set in
60flags.
61.Pp
62On the client side,
63.Xr nfsiod 8
64calls
65.Fn nfssvc
66with the
67.Fa flags
68argument set to
69.Dv NFSSVC_BIOD
70and
71.Fa argstructp
72set to
73.Dv NULL
74to enter the kernel as a block I/O server daemon.
75For
76.Nm NQNFS ,
77.Xr mount_nfs 8
78calls
79.Fn nfssvc
80with the
81.Dv NFSSVC_MNTD
82flag, optionally or'd with the flags
83.Dv NFSSVC_GOTAUTH
84and
85.Dv NFSSVC_AUTHINFAIL
86along with a pointer to a
87.Bd -literal
88struct nfsd_cargs {
89	char		*ncd_dirp;	/* Mount dir path */
90	uid_t		ncd_authuid;	/* Effective uid */
91	int		ncd_authtype;	/* Type of authenticator */
92	int		ncd_authlen;	/* Length of authenticator string */
93	u_char		*ncd_authstr;	/* Authenticator string */
94	int		ncd_verflen;	/* and the verifier */
95	u_char		*ncd_verfstr;
96	NFSKERBKEY_T	ncd_key;	/* Session key */
97};
98.Ed
99.Pp
100structure.
101The initial call has only the
102.Dv NFSSVC_MNTD
103flag set to specify service for the mount point.
104If the mount point is using Kerberos, then the
105.Xr mount_nfs 8
106daemon will return from
107.Fn nfssvc
108with
109.Va errno
110==
111.Er ENEEDAUTH
112whenever the client side requires an ``rcmd''
113authentication ticket for the user.
114.Xr Mount_nfs 8
115will attempt to get the Kerberos ticket, and if successful will call
116.Fn nfssvc
117with the flags
118.Dv NFSSVC_MNTD
119and
120.Dv NFSSVC_GOTAUTH
121after filling the ticket into the
122ncd_authstr field
123and
124setting the ncd_authlen and ncd_authtype
125fields of the nfsd_cargs structure.
126If
127.Xr mount_nfs 8
128failed to get the ticket,
129.Fn nfssvc
130will be called with the flags
131.Dv NFSSVC_MNTD ,
132.Dv NFSSVC_GOTAUTH
133and
134.Dv NFSSVC_AUTHINFAIL
135to denote a failed authentication attempt.
136.Pp
137On the server side,
138.Fn nfssvc
139is called with the flag
140.Dv NFSSVC_NFSD
141and a pointer to a
142.Bd -literal
143struct nfsd_srvargs {
144	struct nfsd	*nsd_nfsd;	/* Pointer to in kernel nfsd struct */
145	uid_t		nsd_uid;	/* Effective uid mapped to cred */
146	u_int32_t	nsd_haddr;	/* Ip address of client */
147	struct ucred	nsd_cr;		/* Cred. uid maps to */
148	int		nsd_authlen;	/* Length of auth string (ret) */
149	u_char		*nsd_authstr;	/* Auth string (ret) */
150	int		nsd_verflen;	/* and the verifier */
151	u_char		*nsd_verfstr;
152	struct timeval	nsd_timestamp;	/* timestamp from verifier */
153	u_int32_t	nsd_ttl;	/* credential ttl (sec) */
154	NFSKERBKEY_T	nsd_key;	/* Session key */
155};
156.Ed
157.Pp
158to enter the kernel as an
159.Xr nfsd 8
160daemon.
161Whenever an
162.Xr nfsd 8
163daemon receives a Kerberos authentication ticket, it will return from
164.Fn nfssvc
165with
166.Va errno
167==
168.Er ENEEDAUTH .
169The
170.Xr nfsd 8
171will attempt to authenticate the ticket and generate a set of credentials
172on the server for the ``user id'' specified in the field nsd_uid.
173This is done by first authenticating the Kerberos ticket and then mapping
174the Kerberos principal to a local name and getting a set of credentials for
175that user via.
176.Xr getpwnam 3
177and
178.Xr getgrouplist 3 .
179If successful, the
180.Xr nfsd 8
181will call
182.Fn nfssvc
183with the
184.Dv NFSSVC_NFSD
185and
186.Dv NFSSVC_AUTHIN
187flags set to pass the credential mapping in nsd_cr into the
188kernel to be cached on the server socket for that client.
189If the authentication failed,
190.Xr nfsd 8
191calls
192.Fn nfssvc
193with the flags
194.Dv NFSSVC_NFSD
195and
196.Dv NFSSVC_AUTHINFAIL
197to denote an authentication failure.
198.Pp
199The master
200.Xr nfsd 8
201server daemon calls
202.Fn nfssvc
203with the flag
204.Dv NFSSVC_ADDSOCK
205and a pointer to a
206.Bd -literal
207struct nfsd_args {
208	int	sock;	/* Socket to serve */
209	caddr_t	name;	/* Client address for connection based sockets */
210	int	namelen;/* Length of name */
211};
212.Ed
213.Pp
214to pass a server side
215.Tn NFS
216socket into the kernel for servicing by the
217.Xr nfsd 8
218daemons.
219.Sh RETURN VALUES
220Normally
221.Fn nfssvc
222does not return unless the server
223is terminated by a signal when a value of 0 is returned.
224Otherwise, -1 is returned and the global variable
225.Va errno
226is set to specify the error.
227.Sh ERRORS
228.Bl -tag -width Er
229.It Bq Er ENEEDAUTH
230This special error value
231is really used for authentication support, particularly Kerberos,
232as explained above.
233.It Bq Er EPERM
234The caller is not the super-user.
235.El
236.Sh SEE ALSO
237.Xr mount_nfs 8 ,
238.Xr nfsd 8 ,
239.Xr nfsiod 8
240.Sh HISTORY
241The
242.Fn nfssvc
243function first appeared in
244.Bx 4.4 .
245.Sh BUGS
246The
247.Fn nfssvc
248system call is designed specifically for the
249.Tn NFS
250support daemons and as such is specific to their requirements.
251It should really return values to indicate the need for authentication
252support, since
253.Er ENEEDAUTH
254is not really an error.
255Several fields of the argument structures are assumed to be valid and
256sometimes to be unchanged from a previous call, such that
257.Fn nfssvc
258must be used with extreme care.
259