rpc_clnt_create(3N) rpc_clnt_create(3N)
NAME
rpc_clnt_create: clnt_control, clnt_create, clnt_destroy,
clnt_dg_create, clnt_pcreateerror, clnt_raw_create,
clnt_spcreateerror, clnt_tli_create, clnt_tp_create,
clnt_vc_create - library routines for dealing with creation
and manipulation of CLIENT handles
SYNOPSIS
cc [options] file -lnsl
#include <rpc/rpc.h>
bool_t clnt_control(CLIENT *clnt, const u_int req, char *info);
CLIENT *clnt_create(const char *host, const u_long prognum,
const u_long versnum, const char *nettype);
void clnt_destroy(CLIENT *clnt);
CLIENT *clnt_dg_create(const int fd, const struct netbut *svcaddr,
const u_long prognum, const u_long versnum,
const u_int sendsz, const u_int recvsz);
void clnt_pcreateerror(const char *s);
CLIENT *clnt_raw_create(const u_long prognum, const u_long versnum);
char *clnt_spcreateerror(const char *s);
CLIENT *clnt_tli_create(const int fd, const struct netconfig *netconf,
const struct netbuf *svcaddr, const u_long prognum,
const u_long versnum, const u_ini sendsz,
const u_int recvsz);
CLIENT *clnt_tp_create(const char *host, const u_long prognum,
const u_long versnum, const struct netconfig *netconf);
CLIENT *clnt_vc_create(const int fd, const struct netbuf * svcaddr,
const u_long prognum, const u_long versnum,
const u_int sendsz, const u_int recvsz);
DESCRIPTION
RPC library routines allow C language programs to make
procedure calls on other machines across the network. First a
CLIENT handle is created and then the client calls a procedure
to send a data packet to the server. Upon receipt of the
packet, the server calls a dispatch routine to perform the
requested service, and then sends back a reply.
Routines
See rpc(3N) for the definition of the CLIENT data structure.
bool_t
clnt_control(CLIENT *clnt, const u_int req, char *info);
A function macro used to change or retrieve various
information about a client object. req indicates the
type of operation, and info is a pointer to the
Copyright 1994 Novell, Inc. Page 1
rpc_clnt_create(3N) rpc_clnt_create(3N)
information. For both connectionless and connection-
oriented transports, the supported values of req and
their argument types and what they do are:
CLSET_TIMEOUT struct timevalset total timeout
CLGET_TIMEOUT struct timevalget total timeout
Note: if you set the timeout using clnt_control, the
timeout parameter passed to clnt_call will be ignored in
all future calls.
CLGET_FD int get the associated file descriptor
CLGET_SVC_ADDR struct netbufget servers address
CLSET_FD_CLOSE intclose the file descriptor when
destroying the client handle
[see clnt_destroy]
CLSET_FD_NCLOSE intdo not close the file
descriptor when destroying
the client handle
The following operations are valid for connectionless
transports only:
CLSET_RETRY_TIMEOUT struct timevalset the retry timeout
CLGET_RETRY_TIMEOUT struct timevalget the retry timeout
The retry timeout is the time that RPC waits for the
server to reply before retransmitting the request.
clnt_control returns 1 on success and 0 on failure.
CLIENT *
clnt_create(const char *host, const u_long prognum,
const u_long versnum, const char *nettype);
Generic client creation routine for program prognum and
version versnum. host identifies the name of the remote
host where the server is located. nettype indicates the
class of transport protocol to use. The transports are
tried in left to right order in NETPATH variable or in
top to down order in the netconfig database.
clnt_create tries all the transports of the nettype
class available from the NETPATH environment variable
and the netconfig database, and chooses the first
successful one. Default timeouts are set, but can be
modified using clnt_control.
Copyright 1994 Novell, Inc. Page 2
rpc_clnt_create(3N) rpc_clnt_create(3N)
void
clnt_destroy(CLIENT *clnt);
A function macro that destroys the client's RPC handle.
Destruction usually involves deallocation of private
data structures, including clnt itself. Use of clnt is
undefined after calling clnt_destroy. If the RPC
library opened the associated file descriptor, or
CLSET_FD_CLOSE was set using clnt_control, it will be
closed.
CLIENT *
clnt_dg_create(const int fd, const struct netbuf *svcaddr,
const u_long prognum, const u_long versnum,
const u_int sendsz, const u_int recvsz);
This routine creates an RPC client for the remote
program prognum and version versnum; the client uses a
connectionless transport. The remote program is located
at address svcaddr. The parameter fd is an open and
bound file descriptor. This routine will resend the
call message in intervals of 15 seconds until a response
is received or until the call times out. The total time
for the call to time out is specified by clnt_call [see
clnt_call in rpc_clnt_calls(3N)]. This routine returns
NULL if it fails. The retry time out and the total time
out periods can be changed using clnt_control. The user
may set the size of the send and receive buffers with
the parameters sendsz and recvsz; values of 0 choose
suitable defaults.
void
clnt_pcreateerror(const char *s);
Print a message to standard error indicating why a
client RPC handle could not be created. The message is
prepended with the string s and a colon, and appended
with a newline.
CLIENT *
clnt_raw_create(const u_long prognum, const u_long versnum);
This routine creates a toy RPC client for the remote
program prognum and version versnum. The transport used
to pass messages to the service is a buffer within the
process's address space, so the corresponding RPC server
Copyright 1994 Novell, Inc. Page 3
rpc_clnt_create(3N) rpc_clnt_create(3N)
should live in the same address space; [see
svc_raw_create in rpc_svc_create(3N)]. This allows
simulation of RPC and acquisition of RPC overheads, such
as round trip times, without any kernel interference.
This routine returns NULL if it fails. clnt_raw_create
should be called after svc_raw_create.
char *
clnt_spcreateerror(const char *s);
Like clnt_pcreateerror, except that it returns a string
instead of printing to the standard error. A newline is
not appended to the message in this case.
Note: returns a pointer to static data that is
overwritten on each call.
CLIENT *
clnt_tli_create(const int fd, const struct netconfig *netconf,
const struct netbuf *svcaddr, const u_long prognum,
const u_long versnum, const u_int sendsz,
const u_int recvsz);
This routine creates an RPC client handle for the remote
program prognum and version versnum. The remote program
is located at address svcaddr. If svcaddr is NULL and
it is connection-oriented, it is assumed that the file
descriptor is connected. For connectionless transports,
if svcaddr is NULL, RPC_UNKNOWNADDR error is set. fd is
a file descriptor which may be open, bound and
connected. If it is RPC_ANYFD, it opens a file
descriptor on the transport specified by netconf. If
netconf is NULL, a RPC_UNKNOWNPROTO error is set. If fd
is unbound, then it will attempt to bind the descriptor.
The user may specify the size of the buffers with the
parameters sendsz and recvsz; values of 0 choose
suitable defaults. Depending upon the type of the
transport (connection-oriented or connectionless),
clnt_tli_create calls appropriate client creation
routines. This routine returns NULL if it fails. The
clnt_pcreateerror routine can be used to print the
reason for failure. The remote rpcbind service [see
rpcbind(1M)] will not be consulted for the address of
the remote service.
Copyright 1994 Novell, Inc. Page 4
rpc_clnt_create(3N) rpc_clnt_create(3N)
CLIENT *
clnt_tp_create(const char *host, const u_long prognum,
const u_long versnum, const struct netconfig *netconf);
clnt_tp_create creates a client handle for the transport
specified by netconf. Default options are set, which
can be changed using clnt_control calls. The remote
rpcbind service on the host host is consulted for the
address of the remote service. This routine returns
NULL if it fails. The clnt_pcreateerror routine can be
used to print the reason for failure.
CLIENT *
clnt_vc_create(const int fd, const struct netbuf *svcaddr,
const u_long prognum, const u_long versnum,
const u_int sendsz, const u_int recvsz);
This routine creates an RPC client for the remote
program prognum and version versnum; the client uses a
connection-oriented transport. The remote program is
located at address svcaddr. The parameter fd is an open
and bound file descriptor. The user may specify the
size of the send and receive buffers with the parameters
sendsz and recvsz; values of 0 choose suitable defaults.
This routine returns NULL if it fails.
The address svcaddr should not be NULL and should point
to the actual address of the remote program.
clnt_vc_create will not consult the remote rpcbind
service for this information.
Files
/usr/lib/locale/locale/LC_MESSAGES/uxns1
REFERENCES
rpcbind(1M), rpc(3N), rpc_clnt_auth(3N), rpc_clnt_calls(3N)
Copyright 1994 Novell, Inc. Page 5