RPC(3)                    OpenBSD Programmer's Manual                   RPC(3)

NAME
     callrpc, clnt_broadcast, clnt_call, clnt_control, clnt_create,
     clnt_destroy, clnt_freeres, clnt_pcreateerror, clnt_perrno, clnt_perror,
     clnt_spcreateerror, clnt_sperrno, clnt_sperror, clntraw_create,
     clnttcp_create, clntudp_bufcreate, clntudp_create, clntudp_create,
     cnlt_geterr, get_myaddress, pmap_getmaps, pmap_getport, pmap_rmtcall,
     pmap_set, pmap_unset, registerrpc, rpc_createerr, svc_fdset,
     svc_freeargs, svc_getargs, svc_getcaller, svc_getreq, svc_getreqset,
     svc_register, svc_sendreply, svc_unregister, svcerr_auth, svcerr_decode,
     svcerr_noproc, svcerr_noprog, svcerr_progvers, svcerr_systemerr,
     svcerr_weakauth, svcfd_create, svctcp_create, svcudp_bufcreate,
     xdr_accepted_reply, xdr_authunix_parms, xdr_callhdr, xdr_callmsg,
     xdr_opaque_auth, xdr_pmap, xdr_pmaplist, xdr_rejected_reply,
     xdr_replymsg, xprt_register, xprt_unregister - library routines for re-
     mote procedure calls



SYNOPSIS
     #include <rpc/rpc.h>

     int
     callrpc(char *host, u_long prognum, u_long versnum, u_long procnum,
             xdrproc_t inproc, char *in, xdrproc_t outproc, char *out);

     enum clnt_stat
     clnt_broadcast(u_long prognum, u_long versnum, u_long procnum,
             xdrproc_t inproc, char *in, xdrproc_t outproc, char *out,
             resultproc_t eachresult);

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

     int
     clnt_destroy(CLIENT *clnt);

     CLIENT *
     clnt_create(char *host, u_long prog, u_long vers, char *proto);

     bool_t
     clnt_control(CLIENT *cl, int req, char *info);

     int
     clnt_freeres(CLIENT *clnt, xdrproc_t outproc, char *out);

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

     void
     clnt_pcreateerror(char *s);

     void
     clnt_perrno(enum clnt_stat stat);

     int
     clnt_perror(CLIENT *clnt, char *s);

     char *
     clnt_spcreateerror(char *s);

     char *
     clnt_sperrno(enum clnt_stat stat);

     char *
     clnt_sperror(CLIENT *rpch, char *s);

     CLIENT *
     clntraw_create(u_long prognum, u_long versnum);

     CLIENT *
     clnttcp_create(struct sockaddr_in *addr, u_long prognum, u_long versnum,
             int *sockp, u_int sendsz, u_int recvsz);

     CLIENT *
     clntudp_create(struct sockaddr_in *addr, u_long prognum, u_long versnum,
             struct timeval wait, int *sockp);

     CLIENT *
     clntudp_bufcreate(struct sockaddr_in *addr, u_long prognum,
             u_long versnum, struct timeval wait, int *sockp,
             unsigned int sendsize, unsigned int recosize);

     int
     get_myaddress(struct sockaddr_in *addr);

     struct pmaplist *
     pmap_getmaps(struct sockaddr_in *addr);

     u_short
     pmap_getport(struct sockaddr_in *addr, u_long prognum, u_long versnum,
             u_long protocol);

     enum clnt_stat
     pmap_rmtcall(struct sockaddr_in *, u_long prog, vers, proc,
             xdrproc_t inp, char *in, xdrproc_t outp, char *out,
             struct timeval tv, u_long *portp);

     int
     pmap_set(u_long prognum, u_long versnum, u_int protocol, u_short port);

     int
     pmap_unset(u_long prognum, u_long versnum);

     int
     registerrpc(u_long prognum, u_long versnum, u_long procnum,
             char *(*procname)(), xdrproc_t inproc, xdrproc_t outproc);

     struct rpc_createerr rpc_createerr;

     int
     svc_destroy(SVCXPRT *xprt);

     fd_set svc_fdset;

     fd_set *__svc_fdset;

     int __svc_fdsetsize;

     int svc_fds;

     int
     svc_freeargs(SVCXPRT *xprt, xdrproc_t inproc, char *in);

     int
     svc_getargs(SVCXPRT *xprt, xdrproc_t inproc, char *in);

     struct sockaddr_in *
     svc_getcaller(SVCXPRT *xprt);

     int
     svc_getreqset(fd_set *rdfds);

     int
     svc_getreq(int rdfds);

     int
     svc_register(SVCXPRT *xprt, u_long prognum, u_long versnum,
             void (*dispatch)(), u_long protocol);

     int
     svc_run(void);

     int
     svc_sendreply(SVCXPRT *xprt, xdrproc_t outproc, char *out);

     void
     svc_unregister(u_long prognum, u_long versnum);

     void
     svcerr_auth(SVCXPRT *xprt, enum auth_stat why);

     void
     svcerr_decode(SVCXPRT *xprt);

     void
     svcerr_noproc(SVCXPRT *xprt);

     void
     svcerr_noprog(SVCXPRT *xprt);

     void
     svcerr_progvers(SVCXPRT *xprt);

     void
     svcerr_systemerr(SVCXPRT *xprt);

     void
     svcerr_weakauth(SVCXPRT *xprt);

     SVCXPRT *
     svcraw_create(void);

     SVCXPRT *
     svctcp_create(int sock, u_int send_buf_size, u_int recv_buf_size);

     SVCXPRT *
     svcfd_create(int fd, u_int sendsize, u_int recvsize);

     SVCXPRT *
     svcudp_bufcreate(int sock);

     bool_t
     xdr_accepted_reply(XDR *xdrs, struct accepted_reply *ar);

     bool_t
     xdr_authunix_parms(XDR *xdrs, struct authunix_parms *aupp);

     void
     xdr_callhdr(XDR *xdrs, struct rpc_msg *chdr);

     int
     xdr_callmsg(XDR *xdrs, struct rpc_msg *cmsg);

     int
     xdr_opaque_auth(XDR *xdrs, struct opaque_auth *ap);

     int
     xdr_pmap(XDR *xdrs, struct pmap *regs);

     int
     xdr_pmaplist(XDR *xdrs, struct pmaplist **rp);

     int
     xdr_rejected_reply(XDR *xdrs, struct rejected_reply *rr);

     int
     xdr_replymsg(XDR *xdrs, struct rpc_msg *rmsg);

     void
     xprt_register(SVCXPRT *xprt);

     void
     xprt_unregister(SVCXPRT *xprt);

DESCRIPTION
     These routines allow C programs to make procedure calls on other machines
     across the network.  First, 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.  Finally, the procedure call returns to the client.

     callrpc() calls the remote procedure associated with prognum, versnum,
     and procnum on the machine, host. The parameter in is the address of the
     procedure's argument(s), and out is the address of where to place the re-
     sult(s); inproc is used to encode the procedure's parameters, and outproc
     is used to decode the procedure's results.  This routine returns zero if
     it succeeds, or the value of cast to an integer if it fails.  The routine
     clnt_perrno() is handy for translating failure statuses into messages.

     Warning: calling remote procedures with this routine uses UDP/IP as a
     transport; see clntudp_create() for restrictions.  You do not have con-
     trol of timeouts or authentication using this routine.

     clnt_broadcast() is like callrpc(), except the call message is broadcast
     to all locally connected broadcast nets. Each time it receives a re-
     sponse, this routine calls eachresult, whose form is:

           int
           eachresult(char *out, struct sockaddr_in *addr)

     where out is the same as out passed to clnt_broadcast(), except that the
     remote procedure's output is decoded there; addr points to the address of
     the machine that sent the results.  If eachresult returns zero,
     clnt_broadcast() waits for more replies; otherwise it returns with appro-
     priate status.

     Warning: broadcast sockets are limited in size to the maximum transfer
     unit of the data link. For Ethernet, this value is 1500 bytes.

     clnt_call() is a macro that calls the remote procedure procnum associated
     with the client handle, clnt, which is obtained with an RPC client cre-
     ation routine such as clnt_create().  The parameter in is the address of
     the procedure's argument(s), and out is the address of where to place the
     result(s); inproc is used to encode the procedure's parameters, and
     outproc is used to decode the procedure's results; tout is the time al-
     lowed for results to come back.

     clnt_destroy() is a macro that destroys the client's RPC handle. Destruc-
     tion 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 socket, it will close it also.
     Otherwise, the socket remains open.
     clnt_create() is a generic client creation routine.  host identifies the
     name of the remote host where the server is located.  proto indicates
     which kind of transport protocol to use. The currently supported values
     for this field are "udp" and "tcp".  Default timeouts are set, but can be
     modified using clnt_control().

     Warning: Using UDP has its shortcomings.  Since UDP-based RPC messages
     can only hold up to 8 Kbytes of encoded data, this transport cannot be
     used for procedures that take large arguments or return huge results.

     clnt_control() is a 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 information. For both UDP and TCP, the supported values
     of req and their argument types and what they do are:

           CLSET_TIMEOUT   struct timeval  set total timeout
           CLGET_TIMEOUT   struct timeval  get 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_SERVER_ADDR       struct sockaddr_in      get server's address

     The following operations are valid for UDP only:

           CLSET_RETRY_TIMEOUT struct timeval      set the retry timeout
           CLGET_RETRY_TIMEOUT struct timeval      get the retry timeout

     The retry timeout is the time that UDP RPC waits for the server to reply
     before retransmitting the request.

     clnt_freeres() is a macro that frees any data allocated by the RPC/XDR
     system 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 one if the results were successfully
     freed, and zero otherwise.

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

     clnt_pcreateerror() print a message to standard error indicating why a
     client RPC handle could not be created.  The message is prepended with
     string s and a colon.  Used when a clnt_create(), clntraw_create(),
     clnttcp_create(), or clntudp_create() call fails.

     clnt_perrno() prints a message to standard error corresponding to the
     condition indicated by stat. Used after callrpc().

     clnt_perror() prints a message to 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.  Used after clnt_call().

     clnt_spcreateerror() is like clnt_pcreateerror(), except that it returns
     a string instead of printing to the standard error.

     Bugs: returns pointer to static data that is overwritten on each call.

     clnt_sperrno() takes 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.  Unlike
     clnt_perror(), it does not append a NEWLINE to the end of the message.

     clnt_sperrno() is used instead of clnt_perrno() if 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(), or if a message format different than that supported by
     clnt_perrno() is to be used.

     Note: unlike clnt_sperror() and clnt_spcreaterror(), clnt_sperrno() re-
     turns pointer to static data, but the result will not get overwritten on
     each call.

     clnt_sperror() is like clnt_perror(), except that (like clnt_sperrno())
     it returns a string instead of printing to standard error.

     Bugs: returns pointer to static data that is overwritten on each call.

     clntraw_create() is a routine which creates a toy RPC client for the re-
     mote program prognum, version versnum. The transport used to pass mes-
     sages to the service is actually a buffer within the process's address
     space, so the corresponding RPC server should live in the same address
     space; see svcraw_create().  This allows simulation of RPC and acquisi-
     tion of RPC overheads, such as round trip times, without any kernel in-
     terference. This routine returns NULL if it fails.

     clnttcp_create() is a routine which creates an RPC client for the remote
     program prognum, version versnum; the client uses TCP/IP as a transport.
     The remote program is located at Internet address *addr. If
     addr->sin_port is zero, then it is set to the actual port that the remote
     program is listening on (the remote portmap(8) service is consulted for
     this information). The parameter sockp is a socket; if it is RPC_ANYSOCK,
     then this routine opens a new one and sets sockp. Since TCP-based RPC us-
     es buffered I/O, the user may specify the size of the send and receive
     buffers with the parameters sendsz and recvsz; values of zero choose
     suitable defaults.  This routine returns NULL if it fails.

     clntudp_create() is a routine which creates an RPC client for the remote
     program prognum, on versnum; the client uses use UDP/IP as a transport.
     The remote program is located at Internet address addr. If addr->sin_port
     is zero, then it is set to actual port that the remote program is listen-
     ing on (the remote portmap(8) service is consulted for this information).
     The parameter sockp is a socket; if it is RPC_ANYSOCK, then this routine
     opens a new one and sets sockp. The UDP transport resends the call mes-
     sage in intervals of wait time 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().

     This allows the user to specify the maximun packet size for sending and
     receiving UDP-based RPC messages.

     get_myaddress() stuffs the machine's IP address into *addr, without con-
     sulting the library routines that deal with /etc/hosts. The port number
     is always set to htons(PMAPPORT). Returns zero on success, non-zero on
     failure.

     pmap_getmaps() is a function interface to the portmap(8) service, which
     returns a list of the current RPC program-to-port mappings on the host
     located at IP address *addr. This routine can return NULL. The command `
     rpcinfo -p ' uses this routine.

     pmap_getport() is a user interface to the portmap(8) service, which re-
     turns the port number on which waits a service that supports program num-
     ber prognum, version versnum, and speaks the transport protocol associat-
     ed with protocol. The value of protocol is most likely IPPROTO_UDP or
     IPPROTO_TCP. A return value of zero means that the mapping does not exist
     or that the RPC system failured to contact the remote portmap(8) service.
     In the latter case, the global variable rpc_createerr() contains the RPC
     status.

     pmap_rmtcall() is a user interface to the portmap(8) service, which in-
     structs portmap(8) on the host at IP address *addr to make an RPC call on
     your behalf to a procedure on that host.  The parameter *portp will be
     modified to the program's port number if the procedure succeeds. The def-
     initions of other parameters are discussed in callrpc() and clnt_call().
     This procedure should be used for a "ping" and nothing else.  See also
     clnt_broadcast().

     pmap_set() is a user interface to the portmap(8) service, which estab-
     lishes a mapping between the triple [prognum, versnum, protocol] and port
     on the machine's portmap(8) service. The value of protocol is most likely
     IPPROTO_UDP or IPPROTO_TCP. This routine returns one if it succeeds, zero
     otherwise.  Automatically done by svc_register().

     pmap_unset() is a user interface to the portmap(8) service, which de-
     stroys all mapping between the triple [prognum, versnum, *] and ports on
     the machine's portmap(8) service. This routine returns one if it suc-
     ceeds, zero otherwise.

     registerrpc() will register a procedure procname with the RPC service
     package.  If a request arrives for program prognum, version versnum, and
     procedure procnum, procname is called with a pointer to its parameter(s);
     progname should return a pointer to its static result(s); inproc is used
     to decode the parameters while outproc is used to encode the results.
     This routine returns zero if the registration succeeded, -1 otherwise.

     Warning: remote procedures registered in this form are accessed using the
     UDP/IP transport; see svcudp_create() for restrictions.

     rpc_createerr is a global variable whose value is set by any RPC client
     creation routine that does not succeed.  Use the routine
     clnt_pcreateerror() to print the reason why.

     svc_destroy() is a macro that destroys the RPC service transport handle,
     xprt. Destruction usually involves deallocation of private data struc-
     tures, including xprt itself.  Use of xprt is undefined after calling
     this routine.

     __svc_fdset and __svc_fdsetsize are global variables reflecting the RPC
     service side's read file descriptor bit mask.  __svc_fdsetsize is a count
     of the number of checkable bits in __svc_fdset, and can expand to the
     full size that select(2) supports, hence exceeding FD_SETSIZE if re-
     quired.  These variables are only of interest if service implementors do
     not call svc_run(), but rather do their own asynchronous event process-
     ing.  This variable is read-only, and it may change after calls to
     svc_getreqset() or any creation routines.  Do not pass its address to
     select(2)!  Instead, pass the address of a copy.

     svc_fdset is similar to __svc_fdset but limited to FD_SETSIZE descrip-
     tors.  This is the preferred interface for portability though.  This is
     only of interest if service implementors do not call svc_run(), but
     rather do their own asynchronous event processing.  This variable is
     read-only, and it may change after calls to svc_getreqset() or any cre-
     ation routines.  Do not pass its address to select(2)!  Instead, pass the
     address of a copy.

     As well, note that if the process has descriptor limits which are extend-
     ed beyond FD_SETSIZE, this variable will only be usable for the first
     FD_SETSIZE descriptors.

     svc_fds is similar to svc_fedset, but limited to 32 descriptors. This in-
     terface is obsoleted by svc_fdset.

     svc_freeargs() is a macro that frees any data allocated by the RPC/XDR
     system when it decoded the arguments to a service procedure using
     svc_getargs().  This routine returns 1 if the results were successfully
     freed, and zero otherwise.

     svc_getargs() is a macro that decodes the arguments of an RPC request as-
     sociated with the RPC service transport handle, xprt. The parameter in is
     the address where the arguments will be placed; inproc is the XDR routine
     used to decode the arguments.  This routine returns one if decoding suc-
     ceeds, and zero otherwise.

     svc_getcaller() is the approved way of getting the network address of the
     caller of a procedure associated with the RPC service transport handle,
     xprt.

     svc_getreqset() is a routine which is only of interest if a service im-
     plementor does not call svc_run(), but instead implements custom asyn-
     chronous event processing.  It is called when the select(2) system call
     has determined that an RPC request has arrived on some RPC socket(s);
     rdfds is the resultant read file descriptor bit mask.  The routine re-
     turns when all sockets associated with the value of rdfds have been ser-
     viced.

     svc_getreq() is similar to svc_getreqset, but limited to 32 descriptors.
     This interface is obsoleted by svc_getreqset.

     svc_register() associates prognum and versnum with the service dispatch
     procedure, dispatch. If protocol is zero, the service is not registered
     with the portmap(8) service.  If protocol is non-zero, then a mapping of
     the triple [prognum, versnum, protocol] to xprt->xp_port is established
     with the local portmap(8) service (generally protocol is zero,
     IPPROTO_UDP or IPPROTO_TCP ).  The procedure dispatch has the following
     form: int dispatch(struct svc_req *request, SVCXPRT *xprt) The
     svc_register() routine returns one if it succeeds, and zero otherwise.

     svc_run() never returns. It waits for RPC requests to arrive, and calls
     the appropriate service procedure using svc_getreq() when one arrives.
     This procedure is usually waiting for a select(2) system call to return.

     svc_sendreply() is called by an RPC service's dispatch routine to send
     the results of a remote procedure call.  The parameter xprt is the re-
     quest's associated transport handle; outproc is the XDR routine which is
     used to encode the results; and out is the address of the results.  This
     routine returns one if it succeeds, zero otherwise.

     svc_unregister() removes all mapping of the double [prognum, versnum] to
     dispatch routines, and of the triple [prognum, versnum, *] to port num-
     ber.

     svcerr_auth() is called by a service dispatch routine that refuses to
     perform a remote procedure call due to an authentication error.

     svcerr_decode() is called by a service dispatch routine that cannot suc-
     cessfully decode its parameters. See also svc_getargs().

     svcerr_noproc() is called by a service dispatch routine that does not im-
     plement the procedure number that the caller requests.

     svcerr_noprog() is called when the desired program is not registered with
     the RPC package. Service implementors usually do not need this routine.

     svcerr_progvers() is called when the desired version of a program is not
     registered with the RPC package. Service implementors usually do not need
     this routine.

     svcerr_systemerr() is called by a service dispatch routine when it de-
     tects a system error not covered by any particular protocol.  For exam-
     ple, if a service can no longer allocate storage, it may call this rou-
     tine.

     svcerr_weakauth() is called by a service dispatch routine that refuses to
     perform a remote procedure call due to insufficient authentication param-
     eters.  The routine calls svcerr_auth(xprt, AUTH_TOOWEAK).

     svcraw_create() is a routine which creates a toy RPC service transport,
     to which it returns a pointer.  The transport is really a buffer within
     the process's address space, so the corresponding RPC client should live
     in the same address space; see clntraw_create().  This routine 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.

     svctcp_create() is a routine which creates a TCP/IP-based RPC service
     transport, to which it returns a pointer.  The transport is associated
     with the socket sock, which may be RPC_ANYSOCK, in which case a new sock-
     et is created.  If the socket is not bound to a local TCP port, then this
     routine binds it to an arbitrary port.  Upon completion, xprt->xp_sock is
     the transport's socket descriptor, and xprt->xp_port is the transport's
     port number.  This routine returns NULL if it fails. Since TCP-based RPC
     uses buffered I/O, users may specify the size of buffers; values of zero
     choose suitable defaults.

     svcfd_create() will create a service on top of any open descriptor. Typi-
     cally, this descriptor is a connected socket for a stream protocol such
     as TCP. sendsize and recvsize indicate sizes for the send and receive
     buffers.  If they are zero, a reasonable default is chosen.

     svcudp_bufcreate() is a routine which creates a UDP/IP-based RPC service
     transport, to which it returns a pointer.  The transport is associated
     with the socket sock, which may be RPC_ANYSOCK, in which case a new sock-
     et is created.  If the socket is not bound to a local UDP port, then this
     routine binds it to an arbitrary port. Upon completion, xprt->xp_sock is
     the transport's socket descriptor, and xprt->xp_port is the transport's
     port number.  This routine returns NULL if it fails.

     This allows the user to specify the maximun packet size for sending and
     receiving UDP-based RPC messages.

     xdr_accepted_reply() is used for encoding RPC reply messages. This rou-
     tine is useful for users who wish to generate RPC-style messages without
     using the RPC package.

     xdr_authunix_parms() is used for describing UNIX credentials. This rou-
     tine is useful for users who wish to generate these credentials without
     using the RPC authentication package.

     xdr_callhdr() is used for describing RPC call header messages.  This rou-
     tine is useful for users who wish to generate RPC-style messages without
     using the RPC package.

     xdr_callmsg() is used for describing RPC call messages.  This routine is
     useful for users who wish to generate RPC-style messages without using
     the RPC package.

     xdr_opaque_auth() is used for describing RPC authentication information
     messages.  This routine is useful for users who wish to generate RPC-
     style messages without using the RPC package.

     xdr_pmap() is used for describing parameters to various portmap(8) proce-
     dures, externally.  This routine is useful for users who wish to generate
     these parameters without using the pmap interface.

     xdr_pmaplist() is used for describing a list of port mappings, external-
     ly.  This routine is useful for users who wish to generate these parame-
     ters without using the pmap interface.

     xdr_rejected_reply() is used for describing RPC reply messages.  This
     routine is useful for users who wish to generate RPC-style messages with-
     out using the RPC package.

     xdr_replymsg() is used for describing RPC reply messages.  This routine
     is useful for users who wish to generate RPC style messages without using
     the RPC package.

     xprt_register() is used to register transport handles.  After RPC service
     transport handles are created, they should register themselves with the
     RPC service package.  This routine modifies the global variable svc_fds.
     Service implementors usually do not need this routine.

     xprt_unregister() is used to unregister a transport handle.  Before an
     RPC service transport handle is destroyed, it should unregister itself
     with the RPC service package.  This routine modifies the global variable
     svc_fds. Service implementors usually do not need this routine.

SEE ALSO
     rpcgen(1),  select(2),  getrpcent(3),  getrpcport(3),  rpcauth(3),
     xdr(3),  rpc(5),  portmap(8)

     The following manuals: Remote Procedure Calls: Protocol Specification;
     Remote Procedure Call Programming Guide; rpcgen Programming Guide; RPC:
     Remote Procedure Call Protocol Specification; RFC1050 Sun Microsystems,
     Inc., USC-ISI.,

OpenBSD 2.6                    February 16, 1988                            10