.\" $NetBSD: nfssvc.2,v 1.9 1999/12/02 21:42:38 kleink Exp $ .\" .\" Copyright (c) 1989, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)nfssvc.2 8.1 (Berkeley) 6/9/93 .\" .Dd June 9, 1993 .Dt NFSSVC 2 .Os .Sh NAME .Nm nfssvc .Nd NFS services .Sh LIBRARY .Lb libc .Sh SYNOPSIS .Fd #include .Fd #include .Ft int .Fn nfssvc "int flags" "void *argstructp" .Sh DESCRIPTION The .Fn nfssvc function is used by the NFS daemons to pass information into and out of the kernel and also to enter the kernel as a server daemon. The .Fa flags argument consists of several bits that show what action is to be taken once in the kernel and the .Fa argstructp points to one of three structures depending on which bits are set in flags. .Pp On the client side, .Xr nfsiod 8 calls .Fn nfssvc with the .Fa flags argument set to .Dv NFSSVC_BIOD and .Fa argstructp set to .Dv NULL to enter the kernel as a block I/O server daemon. For .Nm NQNFS , .Xr mount_nfs 8 calls .Fn nfssvc with the .Dv NFSSVC_MNTD flag, optionally or'd with the flags .Dv NFSSVC_GOTAUTH and .Dv NFSSVC_AUTHINFAIL along with a pointer to a .Bd -literal struct nfsd_cargs { char *ncd_dirp; /* Mount dir path */ uid_t ncd_authuid; /* Effective uid */ int ncd_authtype; /* Type of authenticator */ int ncd_authlen; /* Length of authenticator string */ char *ncd_authstr; /* Authenticator string */ }; .Ed .sp structure. The initial call has only the .Dv NFSSVC_MNTD flag set to specify service for the mount point. If the mount point is using Kerberos, then the .Xr mount_nfs 8 daemon will return from .Fn nfssvc with errno == ENEEDAUTH whenever the client side requires an ``rcmd'' authentication ticket for the user. The .Xr mount_nfs 8 program will attempt to get the Kerberos ticket, and if successful will call .Fn nfssvc with the flags .Dv NFSSVC_MNTD and .Dv NFSSVC_GOTAUTH after filling the ticket into the ncd_authstr field and setting the ncd_authlen and ncd_authtype fields of the nfsd_cargs structure. If .Xr mount_nfs 8 failed to get the ticket, .Fn nfssvc will be called with the flags .Dv NFSSVC_MNTD , .Dv NFSSVC_GOTAUTH and .Dv NFSSVC_AUTHINFAIL to denote a failed authentication attempt. .Pp On the server side, .Fn nfssvc is called with the flag .Dv NFSSVC_NFSD and a pointer to a .Bd -literal 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) */ }; .Ed .sp to enter the kernel as an .Xr nfsd 8 daemon. Whenever an .Xr nfsd 8 daemon receives a Kerberos authentication ticket, it will return from .Fn nfssvc with errno == ENEEDAUTH. The .Xr 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. .Xr getpwnam 3 and .Xr getgrouplist 3 . If successful, the .Xr nfsd 8 will call .Fn nfssvc with the .Dv NFSSVC_NFSD and .Dv 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, .Xr nfsd 8 calls .Fn nfssvc with the flags .Dv NFSSVC_NFSD and .Dv NFSSVC_AUTHINFAIL to denote an authentication failure. .Pp The master .Xr nfsd 8 server daemon calls .Fn nfssvc with the flag .Dv NFSSVC_ADDSOCK and a pointer to a .Bd -literal struct nfsd_args { int sock; /* Socket to serve */ caddr_t name; /* Client address for connection based sockets */ int namelen; /* Length of name */ }; .Ed .sp to pass a server side .Tn NFS socket into the kernel for servicing by the .Xr nfsd 8 daemons. .Sh RETURN VALUES Normally .Nm 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 .Va errno is set to specify the error. .Sh ERRORS .Bl -tag -width Er .It Bq Er ENEEDAUTH This special error value is really used for authentication support, particularly Kerberos, as explained above. .It Bq Er EPERM The caller is not the super-user. .El .Sh SEE ALSO .Xr nfsd 8 , .Xr mount_nfs 8 , .Xr nfsiod 8 .Sh HISTORY The .Nm nfssvc function first appeared in .Bx 4.4 . .Sh BUGS The .Nm nfssvc system call is designed specifically for the .Tn NFS support daemons and as such is specific to their requirements. It should really return values to indicate the need for authentication support, since .Dv ENEEDAUTH is not really an error. Several fields of the argument structures are assumed to be valid and sometimes to be unchanged from a previous call, such that .Nm nfssvc must be used with extreme care.