RPC_CLNT_CALLS(3)       NetBSD Library Functions Manual      RPC_CLNT_CALLS(3)

NAME
     rpc_clnt_calls, clnt_call, clnt_freeres, clnt_geterr, clnt_perrno,
     clnt_perror, clnt_sperrno, clnt_sperror, rpc_broadcast,
     rpc_broadcast_exp, rpc_call -- library routines for client side calls

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <rpc/rpc.h>

     enum clnt_stat
     clnt_call(CLIENT *clnt, const rpcproc_t procnum, const xdrproc_t inproc,
         const char *in, const xdrproc_t outproc, caddr_t out,
         const struct timeval tout);

     bool_t
     clnt_freeres(CLIENT *clnt, const xdrproc_t outproc, caddr_t out);

     void
     clnt_geterr(const CLIENT * clnt, struct rpc_err * errp);

     void
     clnt_perrno(const enum clnt_stat stat);

     void
     clnt_perror(const CLIENT * clnt, const char *s);

     char *
     clnt_sperrno(const enum clnt_stat stat);

     char *
     clnt_sperror(const CLIENT *clnt, const char * s);

     enum clnt_stat
     rpc_broadcast(const rpcprog_t prognum, const rpcvers_t versnum,
         const rpcproc_t procnum, const xdrproc_t inproc, const char *in,
         const xdrproc_t outproc, caddr_t out, const resultproc_t eachresult,
         const char *nettype);

     enum clnt_stat
     rpc_broadcast_exp(rpcprog_t prognum, const rpcvers_t versnum,
         const rpcproc_t procnum, const xdrproc_t xargs,
         caddr_t argsp, const xdrproc_t xresults, caddr_t resultsp,
         const int inittime, const int waittime,
         const resultproc_t eachresult, const char * nettype);

     enum clnt_stat
     rpc_call(const char *host, const rpcprog_t prognum,
         const rpcvers_t versnum,
         const rpcproc_t procnum, const xdrproc_t inproc, const char *in,
         const xdrproc_t outproc, char *out, const char *nettype);

DESCRIPTION
     RPC library routines allow C language programs to make procedure calls on
     other machines across the network.  First, the client calls a procedure
     to send a request to the server.  Upon receipt of the request, the server
     calls a dispatch routine to perform the requested service, and then sends
     back a reply.

     The clnt_call(), rpc_call(), and rpc_broadcast() routines handle the
     client side of the procedure call.  The remaining routines deal with
     error handling in the case of errors.

     Some of the routines take a CLIENT handle as one of the parameters.  A
     CLIENT handle can be created by an RPC creation routine such as
     clnt_create() (see rpc_clnt_create(3)).

     These routines are safe for use in multithreaded applications.  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).

ROUTINES
     See rpc(3) for the definition of the CLIENT data structure.

     clnt_call()
            A function macro that calls the remote procedure procnum associ-
            ated with the client handle, clnt, which is obtained with an RPC
            client creation routine such as clnt_create() (see
            rpc_clnt_create(3)).  The parameter inproc() is the XDR function
            used to encode the procedure's parameters, and outproc() is the
            XDR function used to decode the procedure's results; in() is the
            address of the procedure's argument(s), and out() is the address
            of where to place the result(s).  tout() is the time allowed for
            results to be returned, which is overridden by a time-out set
            explicitly through clnt_control(), see rpc_clnt_create(3).  If the
            remote call succeeds, the status returned is RPC_SUCCESS, other-
            wise an appropriate status is returned.

     clnt_freeres()
            A function macro that frees any data allocated by the RPC/XDR sys-
            tem when it decoded the results of an RPC call.  The parameter out
            is the address of the results, and outproc is the XDR routine
            describing the results.  This routine returns 1 if the results
            were successfully freed, and 0 otherwise.

     clnt_geterr()
            A function macro that copies the error structure out of the client
            handle to the structure at address errp.

     clnt_perrno()
            Print a message to standard error corresponding to the condition
            indicated by stat.  A newline is appended.  Normally used after a
            procedure call fails for a routine for which a client handle is
            not needed, for instance rpc_call().

     clnt_perror()
            Print a message to the standard error indicating why an RPC call
            failed; clnt is the handle used to do the call.  The message is
            prepended with string s and a colon.  A newline is appended.  Nor-
            mally used after a remote procedure call fails for a routine which
            requires a client handle, for instance clnt_call().

     clnt_sperrno()
            Take the same arguments as clnt_perrno(), but instead of sending a
            message to the standard error indicating why an RPC call failed,
            return a pointer to a string which contains the message.
            clnt_sperrno() is normally used instead of clnt_perrno() when the
            program does not have a standard error (as a program running as a
            server quite likely does not), or if the programmer does not want
            the message to be output with printf() (see printf(3)), or if a
            message format different than that supported by clnt_perrno() is
            to be used.  Note: unlike clnt_sperror() and clnt_spcreaterror()
            (see rpc_clnt_create(3)), clnt_sperrno() does not return pointer
            to static data so the result will not get overwritten on each
            call.

     clnt_sperror()
            Like clnt_perror(), except that (like clnt_sperrno()) it returns a
            string instead of printing to standard error.  However,
            clnt_sperror() does not append a newline at the end of the mes-
            sage.  Warning: returns pointer to a buffer that is overwritten on
            each call.

     rpc_broadcast()
            Like rpc_call(), except the call message is broadcast to all the
            connectionless transports specified by nettype.  If nettype is
            NULL, it defaults to ``netpath''.  Each time it receives a
            response, this routine calls eachresult(), whose form is: bool_t
            eachresult(caddr_t out, const struct netbuf * addr, const struct
            netconfig * netconf) where out is the same as out passed to
            rpc_broadcast(), except that the remote procedure's output is
            decoded there; addr points to the address of the machine that sent
            the results, and netconf is the netconfig structure of the trans-
            port on which the remote server responded.  If eachresult()
            returns 0, rpc_broadcast() waits for more replies; otherwise it
            returns with appropriate status.  Warning: broadcast file descrip-
            tors are limited in size to the maximum transfer size of that
            transport.  For Ethernet, this value is 1500 bytes.
            rpc_broadcast() uses AUTH_SYS credentials by default (see
            rpc_clnt_auth(3)).

     rpc_broadcast_exp()
            Like rpc_broadcast(), except that the initial timeout, inittime
            and the maximum timeout, waittime are specified in milliseconds.
            inittime is the initial time that rpc_broadcast_exp() waits before
            resending the request.  After the first resend, the re-transmis-
            sion interval increases exponentially until it exceeds waittime.

     rpc_call()
            Call the remote procedure associated with prognum, versnum, and
            procnum on the machine, host.  The parameter inproc is used to
            encode the procedure's parameters, and outproc is used to decode
            the procedure's results; in is the address of the procedure's
            argument(s), and out is the address of where to place the
            result(s).  nettype can be any of the values listed on rpc(3).
            This routine returns RPC_SUCCESS if it succeeds, or an appropriate
            status is returned.  Use the clnt_perrno() routine to translate
            failure status into error messages.  Warning: rpc_call() uses the
            first available transport belonging to the class nettype, on which
            it can create a connection.  You do not have control of timeouts
            or authentication using this routine.

SEE ALSO
     printf(3), rpc(3), rpc_clnt_auth(3), rpc_clnt_create(3)

NetBSD 5.0_STABLE              December 4, 2005              NetBSD 5.0_STABLE
