minix/lib/libc/rpc/rpc.3

.\" @(#)rpc.3n 1.31 93/08/31 SMI; from SVr4
.\" Copyright 1989 AT&T
.\"	$NetBSD: rpc.3,v 1.22 2010/03/22 19:30:54 joerg Exp $
.Dd May 7, 1993
.Dt RPC 3
.Os
.Sh NAME
.Nm rpc
.Nd library routines for remote procedure calls
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In rpc/rpc.h
.In netconfig.h
.Sh DESCRIPTION
These
routines allow C language programs to make procedure
calls on other machines across a network.
First, the client sends a request to the server.
On receipt of the request, the server calls a dispatch routine
to perform the requested service, and then sends back a reply.
.Pp
All
RPC routines require the header
.In rpc/rpc.h .
Routines that take a
.Fa netconfig
structure also require that
.In netconfig.h
be included.
.Ss Nettype
Some of the high-level
RPC interface routines take a
.Fa nettype
string as one of the parameters
(for example,
.Fn clnt_create ,
.Fn svc_create ,
.Fn rpc_reg ,
.Fn rpc_call .
This string defines a class of transports which can be used
for a particular application.
.Pp
.Fa nettype
can be one of the following:
.Bl -tag -width datagram_v
.It netpath
Choose from the transports which have been
indicated by their token names in the
.Ev NETPATH
environment variable.
If
.Ev NETPATH
is unset or
.Dv NULL
, it defaults to
.Fa visible .
.Fa netpath
is the default
.Fa nettype .
.It visible
Choose the transports which have the visible flag (v)
set in the
.Pa /etc/netconfig
file.
.It circuit_v
This is same as
.Fa visible
except that it chooses only the connection oriented transports
(semantics
.Fa tpi_cots
or
.Fa tpi_cots_ord )
from the entries in the
.Pa /etc/netconfig
file.
.It datagram_v
This is same as
.Fa visible
except that it chooses only the connectionless datagram transports
(semantics
.Fa tpi_clts )
from the entries in the
.Pa /etc/netconfig
file.
.It circuit_n
This is same as
.Fa netpath
except that it chooses only the connection oriented datagram transports
(semantics
.Fa tpi_cots
or
.Fa tpi_cots_ord ) .
.It datagram_n
This is same as
.Fa netpath
except that it chooses only the connectionless datagram transports
(semantics
.Fa tpi_clts ) .
.It udp
This refers to Internet UDP, both version 4 and 6.
.It tcp
This refers to Internet TCP, both version 4 and 6.
.El
.Pp
If
.Fa nettype
is
.Dv NULL ,
it defaults to
.Fa netpath .
The transports are tried in left to right order in the
.Ev NETPATH
variable or in top to down order in the
.Pa /etc/netconfig
file.
.Ss Derived Types
The derived types used in the RPC interfaces are defined as follows:
.Bd -literal
	typedef uint32_t rpcprog_t;
	typedef uint32_t rpcvers_t;
	typedef uint32_t rpcproc_t;
	typedef uint32_t rpcprot_t;
	typedef uint32_t rpcport_t;
	typedef   int32_t rpc_inline_t;
.Ed
.Ss Data Structures
Some of the data structures used by the
RPC package are shown below.
.Ss The AUTH Structure
.Bd -literal
/*
 * Authentication info. Opaque to client.
 */
struct opaque_auth {
    enum_t    oa_flavor;    /* flavor of auth */
    caddr_t    oa_base;    /* address of more auth stuff */
    u_int    oa_length;    /* not to exceed MAX_AUTH_BYTES */
};

/*
 * Auth handle, interface to client side authenticators.
 */
typedef struct {
    struct    opaque_auth    ah_cred;
    struct    opaque_auth    ah_verf;
    struct auth_ops {
        void    (*ah_nextverf)(\|);
        int    (*ah_marshal)(\|);    /* nextverf \*[Am] serialize */
        int    (*ah_validate)(\|);    /* validate verifier */
        int    (*ah_refresh)(\|);    /* refresh credentials */
        void    (*ah_destroy)(\|);    /* destroy this structure */
    } *ah_ops;
    caddr_t ah_private;
} AUTH;
.Ed
.Ss The CLIENT Structure
.Bd -literal
/*
 * Client rpc handle.
 * Created by individual implementations.
 * Client is responsible for initializing auth.
 */

typedef struct {
    AUTH    *cl_auth;    /* authenticator */
    struct clnt_ops {
        enum clnt_stat    (*cl_call)();    /* call remote procedure */
        void    (*cl_abort)();        /* abort a call */
        void    (*cl_geterr)();        /* get specific error code */
        bool_t    (*cl_freeres)();    /* frees results */
        void    (*cl_destroy)();    /* destroy this structure */
        bool_t    (*cl_control)();    /* the ioctl() of rpc */
    } *cl_ops;
    caddr_t    cl_private;    /* private stuff */
    char    *cl_netid;    /* network identifier */
    char    *cl_tp;        /* device name */
} CLIENT;
.Ed
.Ss The SVCXPRT structure
.Bd -literal
enum xprt_stat {
    XPRT_DIED,
    XPRT_MOREREQS,
    XPRT_IDLE
};

/*
 * Server side transport handle
 */
typedef struct {
    int    xp_fd;    /* file descriptor for the server handle */
    u_short    xp_port;    /* obsolete */
    const struct xp_ops {
        bool_t    (*xp_recv)();    /* receive incoming requests */
        enum xprt_stat    (*xp_stat)();    /* get transport status */
        bool_t    (*xp_getargs)();    /* get arguments */
        bool_t    (*xp_reply)();      /* send reply */
        bool_t    (*xp_freeargs)(); /* free mem allocated for args */
        void    (*xp_destroy)();    /* destroy this struct */
    } *xp_ops;
    int    xp_addrlen;    /* length of remote addr.  Obsolete */
    struct sockaddr_in    xp_raddr; /* Obsolete */
    const struct xp_ops2 {
        bool_t    (*xp_control)();    /* catch-all function */
    } *xp_ops2;
    char    *xp_tp;    /* transport provider device name */
    char    *xp_netid;    /* network identifier */
    struct netbuf    xp_ltaddr;    /* local transport address */
    struct netbuf    xp_rtaddr;    /* remote transport address */
    struct opaque_auth    xp_verf;    /* raw response verifier */
    caddr_t    xp_p1;    /* private: for use by svc ops */
    caddr_t    xp_p2;    /* private: for use by svc ops */
    caddr_t    xp_p3;    /* private: for use by svc lib */
    int    xp_type    /* transport type */
} SVCXPRT;
.Ed
.Ss The svc_req structure
.Bd -literal
struct svc_req {
    rpcprog_t    rq_prog;    /* service program number */
    rpcvers_t    rq_vers;    /* service protocol version */
    rpcproc_t    rq_proc;    /* the desired procedure */
    struct opaque_auth    rq_cred;    /* raw creds from the wire */
    caddr_t    rq_clntcred;    /* read only cooked cred */
    SVCXPRT    *rq_xprt;    /* associated transport */
};
.Ed
.Ss The XDR structure
.Bd -literal
/*
 * XDR operations.
 * XDR_ENCODE causes the type to be encoded into the stream.
 * XDR_DECODE causes the type to be extracted from the stream.
 * XDR_FREE can be used to release the space allocated by an XDR_DECODE
 * request.
 */
enum xdr_op {
    XDR_ENCODE=0,
    XDR_DECODE=1,
    XDR_FREE=2
};
/*
 * This is the number of bytes per unit of external data.
 */
#define BYTES_PER_XDR_UNIT    (4)
#define RNDUP(x)  ((((x) + BYTES_PER_XDR_UNIT - 1) /
                   BYTES_PER_XDR_UNIT) \e * BYTES_PER_XDR_UNIT)

/*
 * A xdrproc_t exists for each data type which is to be encoded or
 * decoded.  The second argument to the xdrproc_t is a pointer to
 * an opaque pointer.  The opaque pointer generally points to a
 * structure of the data type to be decoded.  If this points to 0,
 * then the type routines should allocate dynamic storage of the
 * appropriate size and return it.
 * bool_t  (*xdrproc_t)(XDR *, caddr_t *);
 */
typedef  bool_t (*xdrproc_t)();

/*
 * The XDR handle.
 * Contains operation which is being applied to the stream,
 * an operations vector for the particular implementation
 */
typedef struct {
    enum xdr_op    x_op;    /* operation; fast additional param */
    struct xdr_ops {
        bool_t    (*x_getlong)();    /* get a long from underlying stream */
        bool_t    (*x_putlong)();    /* put a long to underlying stream */
        bool_t    (*x_getbytes)(); /* get bytes from underlying stream */
        bool_t    (*x_putbytes)(); /* put bytes to underlying stream */
        u_int    (*x_getpostn)(); /* returns bytes off from beginning */
        bool_t    (*x_setpostn)(); /* lets you reposition the stream */
        long *    (*x_inline)();    /* buf quick ptr to buffered data */
        void    (*x_destroy)();    /* free privates of this xdr_stream */
    } *x_ops;
    caddr_t    x_public;    /* users' data */
    caddr_t    x_private;    /* pointer to private data */
    caddr_t    x_base;    /* private used for position info */
    int    x_handy;    /* extra private word */
} XDR;

/*
 * The netbuf structure. This structure is defined in \*[Lt]xti.h\*[Gt] on SysV
 * systems, but NetBSD does not use XTI.
 *
 * Usually, buf will point to a struct sockaddr, and len and maxlen
 * will contain the length and maximum length of that socket address,
 * respectively.
 */
struct netbuf {
	unsigned int maxlen;
	unsigned int len;
	void *buf;
};

/*
 * The format of the address and options arguments of the XTI t_bind call.
 * Only provided for compatibility, it should not be used other than
 * as an argument to svc_tli_create().
 */

struct t_bind {
	struct netbuf   addr;
	unsigned int    qlen;
};
.Ed
.Ss Index to Routines
The following table lists RPC routines and the manual reference
pages on which they are described:
.Bl -column "authunix_create_default()" "rpc_clnt_create(3)"
.It Em "RPC Routine" Ta Em "Manual Reference Page"
.Pp
.It Fn auth_destroy Ta Xr rpc_clnt_auth 3 ,
.It Fn authdes_create Ta Xr rpc_soc 3 ,
.It Fn authnone_create Ta Xr rpc_clnt_auth 3 ,
.It Fn authsys_create Ta Xr rpc_clnt_auth 3 ,
.It Fn authsys_create_default Ta Xr rpc_clnt_auth 3 ,
.It Fn authunix_create Ta Xr rpc_soc 3 ,
.It Fn authunix_create_default Ta Xr rpc_soc 3 ,
.It Fn callrpc Ta Xr rpc_soc 3 ,
.It Fn clnt_broadcast Ta Xr rpc_soc 3 ,
.It Fn clnt_call Ta Xr rpc_clnt_calls 3 ,
.It Fn clnt_control Ta Xr rpc_clnt_create 3 ,
.It Fn clnt_create Ta Xr rpc_clnt_create 3 ,
.It Fn clnt_destroy Ta Xr rpc_clnt_create 3 ,
.It Fn clnt_dg_create Ta Xr rpc_clnt_create 3 ,
.It Fn clnt_freeres Ta Xr rpc_clnt_calls 3 ,
.It Fn clnt_geterr Ta Xr rpc_clnt_calls 3 ,
.It Fn clnt_pcreateerror Ta Xr rpc_clnt_create 3 ,
.It Fn clnt_perrno Ta Xr rpc_clnt_calls 3 ,
.It Fn clnt_perror Ta Xr rpc_clnt_calls 3 ,
.It Fn clnt_raw_create Ta Xr rpc_clnt_create 3 ,
.It Fn clnt_spcreateerror Ta Xr rpc_clnt_create 3 ,
.It Fn clnt_sperrno Ta Xr rpc_clnt_calls 3 ,
.It Fn clnt_sperror Ta Xr rpc_clnt_calls 3 ,
.It Fn clnt_tli_create Ta Xr rpc_clnt_create 3 ,
.It Fn clnt_tp_create Ta Xr rpc_clnt_create 3 ,
.It Fn clnt_udpcreate Ta Xr rpc_soc 3 ,
.It Fn clnt_vc_create Ta Xr rpc_clnt_create 3 ,
.It Fn clntraw_create Ta Xr rpc_soc 3 ,
.It Fn clnttcp_create Ta Xr rpc_soc 3 ,
.It Fn clntudp_bufcreate Ta Xr rpc_soc 3 ,
.It Fn get_myaddress Ta Xr rpc_soc 3 ,
.It Fn pmap_getmaps Ta Xr rpc_soc 3 ,
.It Fn pmap_getport Ta Xr rpc_soc 3 ,
.It Fn pmap_rmtcall Ta Xr rpc_soc 3 ,
.It Fn pmap_set Ta Xr rpc_soc 3 ,
.It Fn pmap_unset Ta Xr rpc_soc 3 ,
.It Fn registerrpc Ta Xr rpc_soc 3 ,
.It Fn rpc_broadcast Ta Xr rpc_clnt_calls 3 ,
.It Fn rpc_broadcast_exp Ta Xr rpc_clnt_calls 3 ,
.It Fn rpc_call Ta Xr rpc_clnt_calls 3 ,
.It Fn rpc_reg Ta Xr rpc_svc_calls 3 ,
.It Fn svc_create Ta Xr rpc_svc_create 3 ,
.It Fn svc_destroy Ta Xr rpc_svc_create 3 ,
.It Fn svc_dg_create Ta Xr rpc_svc_create 3 ,
.It Fn svc_dg_enablecache Ta Xr rpc_svc_calls 3 ,
.It Fn svc_fd_create Ta Xr rpc_svc_create 3 ,
.It Fn svc_fds Ta Xr rpc_soc 3 ,
.It Fn svc_freeargs Ta Xr rpc_svc_reg 3 ,
.It Fn svc_getargs Ta Xr rpc_svc_reg 3 ,
.It Fn svc_getcaller Ta Xr rpc_soc 3 ,
.It Fn svc_getreq Ta Xr rpc_soc 3 ,
.It Fn svc_getreqset Ta Xr rpc_svc_calls 3 ,
.It Fn svc_getrpccaller Ta Xr rpc_svc_calls 3 ,
.It Fn svc_kerb_reg Ta Xr kerberos_rpc 3 ,
.It Fn svc_raw_create Ta Xr rpc_svc_create 3 ,
.It Fn svc_reg Ta Xr rpc_svc_calls 3 ,
.It Fn svc_register Ta Xr rpc_soc 3 ,
.It Fn svc_run Ta Xr rpc_svc_reg 3 ,
.It Fn svc_sendreply Ta Xr rpc_svc_reg 3 ,
.It Fn svc_tli_create Ta Xr rpc_svc_create 3 ,
.It Fn svc_tp_create Ta Xr rpc_svc_create 3 ,
.It Fn svc_unreg Ta Xr rpc_svc_calls 3 ,
.It Fn svc_unregister Ta  Xr rpc_soc 3 ,
.It Fn svc_vc_create Ta Xr rpc_svc_create 3 ,
.It Fn svcerr_auth Ta Xr rpc_svc_err 3 ,
.It Fn svcerr_decode Ta Xr rpc_svc_err 3 ,
.It Fn svcerr_noproc Ta Xr rpc_svc_err 3 ,
.It Fn svcerr_noprog Ta Xr rpc_svc_err 3 ,
.It Fn svcerr_progvers Ta Xr rpc_svc_err 3 ,
.It Fn svcerr_systemerr Ta Xr rpc_svc_err 3 ,
.It Fn svcerr_weakauth Ta Xr rpc_svc_err 3 ,
.It Fn svcfd_create Ta Xr rpc_soc 3 ,
.It Fn svcraw_create Ta Xr rpc_soc 3 ,
.It Fn svctcp_create Ta Xr rpc_soc 3 ,
.It Fn svcudp_bufcreate Ta Xr rpc_soc 3 ,
.It Fn svcudp_create Ta Xr rpc_soc 3 ,
.It Fn xdr_accepted_reply Ta Xr rpc_xdr 3 ,
.It Fn xdr_authsys_parms Ta Xr rpc_xdr 3 ,
.It Fn xdr_authunix_parms Ta Xr rpc_soc 3 ,
.It Fn xdr_callhdr Ta Xr rpc_xdr 3 ,
.It Fn xdr_callmsg Ta Xr rpc_xdr 3 ,
.It Fn xdr_opaque_auth Ta Xr rpc_xdr 3 ,
.It Fn xdr_rejected_reply Ta Xr rpc_xdr 3 ,
.It Fn xdr_replymsg Ta Xr rpc_xdr 3 ,
.It Fn xprt_register Ta Xr rpc_svc_calls 3 ,
.It Fn xprt_unregister Ta Xr rpc_svc_calls 3 ,
.El
.Sh FILES
.Pa /etc/netconfig
.Sh SEE ALSO
.Xr getnetconfig 3 ,
.Xr getnetpath 3 ,
.Xr rpc_clnt_auth 3 ,
.Xr rpc_clnt_calls 3 ,
.Xr rpc_clnt_create 3 ,
.Xr rpc_svc_calls 3 ,
.Xr rpc_svc_create 3 ,
.Xr rpc_svc_err 3 ,
.Xr rpc_svc_reg 3 ,
.Xr rpc_xdr 3 ,
.Xr rpcbind 3 ,
.Xr xdr 3 ,
.Xr netconfig 5