RPC(3NSL) Networking Services Library Functions RPC(3NSL)


NAME


rpc - library routines for remote procedure calls

SYNOPSIS


cc [ flag ... ] file ... -lnsl [ library ... ]
#include <rpc/rpc.h>
#include <netconfig.h>


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.


All RPC routines require the header <rpc/rpc.h>. Routines that take a
netconfig structure also require that <netconfig.h> be included.
Applications using RPC and XDR routines should be linked with the
libnsl library.

Multithread Considerations


In the case of multithreaded applications, the -mt option must be
specified on the command line at compilation time to enable a thread-
specific version of rpc_createerr(). See rpc_clnt_create(3NSL) and
threads(5).


When used in multithreaded applications, client-side routines are MT-
Safe. CLIENT handles can be shared between threads; however, in this
implementation, requests by different threads are serialized (that is,
the first request will receive its results before the second request is
sent). See rpc_clnt_create(3NSL).


When used in multithreaded applications, server-side routines are usually
Unsafe. In this implementation the service transport handle, SVCXPRT
contains a single data area for decoding arguments and encoding results.
See rpc_svc_create(3NSL). Therefore, this structure cannot be freely
shared between threads that call functions that do this. Routines that
are affected by this restriction are marked as unsafe for MT
applications. See rpc_svc_calls(3NSL).

Nettype


Some of the high-level RPC interface routines take a nettype string as
one of the parameters (for example, clnt_create(), svc_create(),
rpc_reg(), rpc_call()). This string defines a class of transports which
can be used for a particular application.


nettype can be one of the following:

netpath
Choose from the transports which have been indicated by
their token names in the NETPATH environment variable. If
NETPATH is unset or NULL, it defaults to visible. netpath
is the default nettype.


visible
Choose the transports which have the visible flag (v) set
in the /etc/netconfig file.


circuit_v
This is same as visible except that it chooses only the
connection oriented transports (semantics tpi_cots or
tpi_cots_ord) from the entries in the /etc/netconfig file.


datagram_v
This is same as visible except that it chooses only the
connectionless datagram transports (semantics tpi_clts)
from the entries in the /etc/netconfig file.


circuit_n
This is same as netpath except that it chooses only the
connection oriented datagram transports (semantics tpi_cots
or tpi_cots_ord).


datagram_n
This is same as netpath except that it chooses only the
connectionless datagram transports (semantics tpi_clts).


udp
This refers to Internet UDP.


tcp
This refers to Internet TCP.


If nettype is NULL, it defaults to netpath. The transports are tried in
left to right order in the NETPATH variable or in top to down order in
the /etc/netconfig file.

Derived Types


In a 64-bit environment, the derived types are defined as follows:


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;


In a 32-bit environment, the derived types are defined as follows:


typedef unsigned long rpcprog_t;
typedef unsigned long rpcvers_t;
typedef unsigned long rpcproc_t;
typedef unsigned long rpcprot_t;
typedef unsigned long rpcport_t;
typedef long rpc_inline_t;


Data Structures


Some of the data structures used by the RPC package are shown below.

The AUTH Structure
union des_block {
struct {
u_int32 high;
u_int32 low;
} key;
char c[8];
};
typedef union des_block des_block;
extern bool_t xdr_des_block();
/*
* Authentication info. Opaque to client.
*/
struct opaque_auth {
enum_t oa_flavor; /* flavor of auth */
caddr_t oa_base; /* address of more auth stuff */
uint_t 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;
union des_block ah_key;
struct auth_ops {
void(*ah_nextverf)();
int(*ah_marshal)(); /* nextverf & serialize */
int(*ah_validate)(); /* validate verifier */
int(*ah_refresh)(); /* refresh credentials */
void(*ah_destroy)(); /* destroy this structure */
} *ah_ops;
caddr_t ah_private;
} AUTH;


The CLIENT Structure
/*
* 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 */
int (*cl_settimers)(); /* set rpc level timers */
} *cl_ops;
caddr_t cl_private; /* private stuff */
char *cl_netid; /* network identifier */
char *cl_tp; /* device name */
} CLIENT;


The SVCXPRT Structure
enum xprt_stat {
XPRT_DIED,
XPRT_MOREREQS,
XPRT_IDLE
};
/*
* Server side transport handle
*/
typedef struct {
int xp_fd; /* file descriptor for the
ushort_t xp_port; /* obsolete */
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 */
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 */
char xp_raddr[16]; /* remote address. Obsolete */
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;


The svc_reg Structure
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 */

};


The XDR Structure
/*
* 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) \ * 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 long from underlying stream */
bool_t (*x_putlong)(); /* put long to underlying stream */
bool_t (*x_getbytes)(); /* get bytes from underlying stream */
bool_t (*x_putbytes)(); /* put bytes to underlying stream */
uint_t (*x_getpostn)(); /* returns bytes off from beginning */
bool_t (*x_setpostn)(); /* reposition the stream */
rpc_inline_t *(*x_inline)(); /* buf quick ptr to buffered data */
void (*x_destroy)(); /* free privates of this xdr_stream */
bool_t (*x_control)(); /* changed/retrieve client object info*/
bool_t (*x_getint32)(); /* get int from underlying stream */
bool_t (*x_putint32)(); /* put int to underlying stream */

} *x_ops;

caddr_t x_public; /* users' data */
caddr_t x_priv /* pointer to private data */
caddr_t x_base; /* private used for position info */
int x_handy; /* extra private word */
XDR;


Index to Routines


The following table lists RPC routines and the manual reference pages on
which they are described:

RPC Routine
Manual Reference Page


auth_destroy
rpc_clnt_auth(3NSL)


authdes_create
rpc_soc(3NSL)


authdes_getucred
secure_rpc(3NSL)


authdes_seccreate
secure_rpc(3NSL)


authnone_create
rpc_clnt_auth(3NSL)


authsys_create
rpc_clnt_auth(3NSL)


authsys_create_default
rpc_clnt_auth(3NSL)


authunix_create
rpc_soc(3NSL)


authunix_create_default
rpc_soc(3NSL)


callrpc
rpc_soc(3NSL)


clnt_broadcast
rpc_soc(3NSL)


clnt_call
rpc_clnt_calls(3NSL)


clnt_control
rpc_clnt_create(3NSL)


clnt_create
rpc_clnt_create(3NSL)


clnt_destroy
rpc_clnt_create(3NSL)


clnt_dg_create
rpc_clnt_create(3NSL)


clnt_freeres
rpc_clnt_calls(3NSL)


clnt_geterr
rpc_clnt_calls(3NSL)


clnt_pcreateerror
rpc_clnt_create(3NSL)


clnt_perrno
rpc_clnt_calls(3NSL)


clnt_perror
rpc_clnt_calls(3NSL)


clnt_raw_create
rpc_clnt_create(3NSL)


clnt_spcreateerror
rpc_clnt_create(3NSL)


clnt_sperrno
rpc_clnt_calls(3NSL)


clnt_sperror
rpc_clnt_calls(3NSL)


clnt_tli_create
rpc_clnt_create(3NSL)


clnt_tp_create
rpc_clnt_create(3NSL)


clnt_vc_create
rpc_clnt_create(3NSL)


clntraw_create
rpc_soc(3NSL)


clnttcp_create
rpc_soc(3NSL)


clntudp_bufcreate
rpc_soc(3NSL)


clntudp_create
rpc_soc(3NSL)


get_myaddress
rpc_soc(3NSL)


getnetname
secure_rpc(3NSL)


host2netname
secure_rpc(3NSL)


key_decryptsession
secure_rpc(3NSL)


key_encryptsession
secure_rpc(3NSL)


key_gendes
secure_rpc(3NSL)


key_setsecret
secure_rpc(3NSL)


netname2host
secure_rpc(3NSL)


netname2user
secure_rpc(3NSL)


pmap_getmaps
rpc_soc(3NSL)


pmap_getport
rpc_soc(3NSL)


pmap_rmtcall
rpc_soc(3NSL)


pmap_set
rpc_soc(3NSL)


pmap_unset
rpc_soc(3NSL)


registerrpc
rpc_soc(3NSL)


rpc_broadcast
rpc_clnt_calls(3NSL)


rpc_broadcast_exp
rpc_clnt_calls(3NSL)


rpc_call
rpc_clnt_calls(3NSL)


rpc_reg
rpc_svc_reg(3NSL)


svc_create
rpc_svc_create(3NSL)


svc_destroy
rpc_svc_create(3NSL)


svc_dg_create
rpc_svc_create(3NSL)


svc_dg_enablecache
rpc_svc_calls(3NSL)


svc_fd_create
rpc_svc_create(3NSL)


svc_fds
rpc_soc(3NSL)


svc_freeargs
rpc_svc_calls(3NSL)


svc_getargs
rpc_svc_calls(3NSL)


svc_getcaller
rpc_soc(3NSL)


svc_getreq
rpc_soc(3NSL)


svc_getreqset
rpc_svc_calls(3NSL)


svc_getrpccaller
rpc_svc_calls(3NSL)


svc_raw_create
rpc_svc_create(3NSL)


svc_reg
rpc_svc_reg(3NSL)


svc_register
rpc_soc(3NSL)


svc_run
rpc_svc_calls(3NSL)


svc_sendreply
rpc_svc_calls(3NSL)


svc_tli_create
rpc_svc_create(3NSL)


svc_tp_create
rpc_svc_create(3NSL)


svc_unreg
rpc_svc_reg(3NSL)


svc_unregister
rpc_soc(3NSL)


svc_vc_create
rpc_svc_create(3NSL)


svcerr_auth
rpc_svc_err(3NSL)


svcerr_decode
rpc_svc_err(3NSL)


svcerr_noproc
rpc_svc_err(3NSL)


svcerr_noprog
rpc_svc_err(3NSL)


svcerr_progvers
rpc_svc_err(3NSL)


svcerr_systemerr
rpc_svc_err(3NSL)


svcerr_weakauth
rpc_svc_err(3NSL)


svcfd_create
rpc_soc(3NSL)


svcraw_create
rpc_soc(3NSL)


svctcp_create
rpc_soc(3NSL)


svcudp_bufcreate
rpc_soc(3NSL)


svcudp_create
rpc_soc(3NSL)


user2netname
secure_rpc(3NSL)


xdr_accepted_reply
rpc_xdr(3NSL)


xdr_authsys_parms
rpc_xdr(3NSL)


xdr_authunix_parms
rpc_soc(3NSL)


xdr_callhdr
rpc_xdr(3NSL)


xdr_callmsg
rpc_xdr(3NSL)


xdr_opaque_auth
rpc_xdr(3NSL)


xdr_rejected_reply
rpc_xdr(3NSL)


xdr_replymsg
rpc_xdr(3NSL)


xprt_register
rpc_svc_reg(3NSL)


xprt_unregister
rpc_svc_reg(3NSL)


FILES


/etc/netconfig

ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+---------------+-------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-------------------------+
|MT-Level | MT-Safe with exceptions |
+---------------+-------------------------+

SEE ALSO


getnetconfig(3NSL), getnetpath(3NSL), rpc_clnt_auth(3NSL),
rpc_clnt_calls(3NSL), rpc_clnt_create(3NSL), rpc_svc_calls(3NSL),
rpc_svc_create(3NSL), rpc_svc_err(3NSL), rpc_svc_reg(3NSL),
rpc_xdr(3NSL), rpcbind(3NSL), secure_rpc(3NSL), threads(5), xdr(3NSL),
netconfig(4), rpc(4), attributes(5), environ(5)


November 24, 2014 RPC(3NSL)