rpc(3N) rpc(3N)NAME auth_destroy, authnone_create, authdes_getucred, authunix_create, authunix_create_default, callrpc, clnt_broadcast, clnt_call, clnt_destroy, clnt_create, clnt_control, clnt_freeres, clnt_geterr, clnt_pcreateerror, clnt_perrno, clnt_spcreateerror, clnt_sperrno, clnt_sperror, clntraw_create, clnttcp_create, clntudp_create, hostname2netname, get_myaddress, getnetname, netname2host, netname2user, pmap_getmaps, pmap_getport, pmap_rmtcall, pmap_set, pmap_unset, registerrpc, svc_destroy, svc_freeargs, svc_getargs, svc_getcaller, svc_getreqset, svc_getreq, svc_register, svc_run, svc_sendreply, svc_unregister, svcerr_auth, svcerr_decode, svcerr_noproc, svcerr_noprog, svcerr_progvers, svcerr_systemerr, svcerr_weakauth, svcraw_create, svctcp_create, svcfd_create, svcudp_create, user2netname, 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 remote procedure calls SYNOPSIS #include <rpc/rpc.h> fd_set svc_fdset; int svc_fds; struct rpc_createerr rpc_createerr; void auth_destroy(auth) AUTH *auth; AUTH *authnone_create() authdes_getucred(adc, uid, gid, grouplen, groups) struct authdes_cred *adc; short *uid, *gid, *grouplen; int *groups; AUTH *authunix_create(host, uid, gid, len, aup_gids) char *host; int uid, gid, len, *aup.gids; AUTH *authunix_create_default() callrpc(host, prognum, versnum, procnum, inproc, in, outproc, out) char *host; u_long prognum, versnum, procnum; char *in, *out; January 1992 1
rpc(3N) rpc(3N)xdrproc_t inproc, outproc; enum clnt_stat clnt_broadcast(prognum, versnum, procnum, inproc, in, outproc, out, eachresult) u_long prognum, versnum, procnum; char *in, *out; xdrproc_t inproc, outproc; resultproc_t eachresult; enum clnt_stat clnt_call(clnt, procnum, inproc, in, outproc, out, tout) CLIENT *clnt; u_long procnum; xdrproc_t inproc, outproc; char *in, *out; struct timeval tout; clnt_destroy(clnt) CLIENT *clnt; CLIENT *clnt_create(host, prog, vers, proto) char *host; u_long prog, vers; char *proto; bool_t clnt_control(cl, req, info) CLIENT *cl; char *info; clnt_freeres(clnt, outproc, out) CLIENT *clnt; xdrproc_t outproc; char *out; void clnt_geterr(clnt, errp) CLIENT *clnt; struct rpc_err *errp; void clnt_pcreateerror(s) char *s; void clnt_perrno(stat) enum clnt_stat stat; clnt_perror(clnt, s) CLIENT *clnt; char *s; char *clnt_spcreateerror(s) char *s; 2 January 1992
rpc(3N) rpc(3N)char *clnt_sperrno(stat) enum clnt_stat stat; char *clnt_sperror(rpch, s) CLIENT *rpch; char *s; CLIENT *clntraw_create(prognum, versnum) u_long prognum, versnum; CLIENT *clnttcp_create(addr, prognum, versnum, sockp, sendsz, recvsz) struct sockaddr_in *addr; u_long prognum, versnum; int *sockp; u_int sendsz, recvsz; CLIENT *clntudp_create(addr, pronum, versnum, wait, sockp) struct sockaddr_in *addr; u_long prognum, versnum; struct timeval wait; int *sockp; host2netname(name, host, domain) char *name, *host, *domain; void get_myaddress(addr) struct sockaddr_in *addr; getnetname(name) char name[MAXNETNAMELEN]; netname2host(name, host, hostlen) char *name, *host; int hostlen; netname2user(name, uidp, gidp, gidlenp, gidlist) char *name; int *uidp, *gidp, *gidlenp, *gidlist; struct pmaplist *pmap_getmaps(addr) struct sockaddr_in *addr; u_short pmap_getport(addr, prognum, versnum, protocol) struct sockaddr_in *addr; u_long prognum, versnum, protocol; enum clnt_stat pmap_rmtcall(addr, prognum, versnum, procnum, inproc, in, outproc, out, tout, portp) January 1992 3
rpc(3N) rpc(3N)struct sockaddr_in *addr; u_long prognum, versnum, procnum; char *in, *out; xdrproc_t inproc, outproc; struct timeval tout; u_long *portp; pmap_set(prognum, versnum, protocol, port) u_long prognum, versnum, protocol; u_short port; pmap_unset(prognum, versnum) u_long prognum, versnum; registerrpc(prognum, versnum, procnum, procname, inproc, outproc) u_long prognum, versnum, procnum; char *(*procname) (); xdrproc_t inproc, outproc; svc_destroy(xprt) SVCXPRT *xprt; svc_freeargs(xprt, inproc, in) SVCXPRT *xprt; xdrproc_t inproc; char *in; svc_getargs(xprt, inproc, in) SVCXPRT *xprt; xdrproc_t inproc; char *in; struct sockaddr_in *svc_getcaller(xprt) SVCXPRT *xprt; svc_getreqset(rdfds) fd_set *rdfds; svc_getreq(rdfds) int rdfds; svc_register(xprt, prognum, versnum, dispatch, protocol) SVCXPRT *xprt; u_long prognum, versnum; void (*dispatch) (); u_long protocol; svc_run() 4 January 1992
rpc(3N) rpc(3N)svc_sendreply(xprt, outproc, out) SVCXPRT *xprt; xdrproc_t outproc; char *out; void svc_unregister(prognum, versnum) u_long prognum, versnum; void svcerr_auth(xprt, why) SVCXPRT *xprt; enum auth_stat why; void svcerr_decode(xprt) SVCXPRT *xprt; void svcerr_noproc(xprt) SVCXPRT *xprt; void svcerr_noprog(xprt) SVCXPRT *xprt; void svcerr_progvers(xprt) SVCXPRT *xprt; void svcerr_systemerr(xprt) SVCXPRT *xprt; void svcerr_weakauth(xprt) SVCXPRT *xprt; SVCXPRT *svcraw_create() SVCXPRT *svctcp_create(sock, send_buf_size, recv_buf_size) int sock; u_int send_buf_size, recv_buf_size; void svcfd_create(fd, sendsize, recvsize) int fd; u_int sendsize, recvsize; SVCXPRT *svcudp_create(sock) int sock; user2netname(name, uid, domain) char *name; int uid; char *domain; xdr_accepted_reply(xdrs, ar) XDR *xdrs; struct accepted_reply *ar; January 1992 5
rpc(3N) rpc(3N)xdr_authunix_parms(xdrs, aupp) XDR *xdrs; struct authunix_parms *aupp; void xdr_callhdr(xdrs, chdr) XDR *xdrs; struct rpc_msg *chdr; xdr_callmsg(xdrs, cmsg) XDR *xdrs; struct rpc_msg *cmsg; xdr_opaque_auth(xdrs, ap) XDR *xdrs; struct opaque_auth *ap; xdr_pmap(xdrs, regs) XDR *xdrs; struct pmap *regs; xdr_pmaplist(xdrs, rp) XDR *xdrs; struct pmaplist **rp; xdr_rejected_reply(xdrs, rr) XDR *xdrs; struct rejected_reply *rr; xdr_replymsg(xdrs, rmsg) XDR *xdrs; struct rpc_msg *rmsg; void xprt_register(xprt) SVCXPRT *xprt; void xprt_unregister(xprt) SVCXPRT *xprt; DESCRIPTION These routines allow C programs to make a remote procedure call (RPC) on other computers 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 sends back a reply. Finally, the procedure call returns to the client. auth_destroy() is a macro that destroys the authentication information associated with auth. Destruction usually involves deallocation of private data structures. The use of auth is undefined after calling auth_destroy(). 6 January 1992
rpc(3N) rpc(3N)authnone_create() creates and returns an RPC authentication handle that passes nonusable authentication information with each remote procedure call. This is the default authentication used by RPC. authdes_getucred() is one of two DES authentication routines. This routine is used on the server side for converting a DES credential, which is operating systemrindependent, into a UNIX credential. This routine differsfrom netname2user() in that authdes_getucred() pulls its information from a cache, and does not have to do a Network Information Service lookup every time it is called to get its information. authunix_create() creates and returns an RPC authentication handle that contains UNIX authentication information. The parameter host is the name of the machine on which the information was created; uid is the user's user ID; gid is the user's current group ID; len and aup_gids refer to a counted array of groups to which the user belongs. It is easy to impersonate a user. authunix_create_default() is a function that calls authunix_create() with the appropriate parameters. callrpc() calls the remote procedure associated with prognum, versnum, and procnum on the the computer specified by host. The parameter in is the address of the procedure's arguments, and out is the address of where to place the results; inproc is used to encode the procedure's parameters, and outproc is used to decode the procedure's results. This routine returns 0 if it succeeds, or the value of enum clnt_stat 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 control of timeouts or authentication using this routine. clnt_broadcast() is similar to callrpc(), except the call message is broadcast to all locally connected broadcast nets. Each time it receives a response, this routine calls eachresult(), whose form is: eachresult(out, addr) 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; January 1992 7
rpc(3N) rpc(3N)addr points to the address of the machine that sent the results. If eachresult() returns 0, clnt_broadcast() waits for more replies; otherwise it returns with appropriate 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 creation routine such as clnt_create(). The parameter in is the address of the procedure's arguments, and out is the address of where to place the results; inproc is used to encode the procedure's parameters, and outproc is used to decode the procedure's results; tout is the time allowed for results to come back. clnt_destroy() is a 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 socket, it will close it also. Otherwise, the socket remains open. clnt_create() is the generic client creation routine. The parameter 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. Because 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 a variety of information about a client object. The parameter 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: Value Argument typeResult CLSET_TIMEOUT struct timevalSets the total timeout. CLGET_TIMEOUT struct timevalGets the total timeout. CLGET_SERVER_ADDR struct sockaddrGets the server's address. CLSET_RETRY_TIMEOUT struct timevalSets the retry timeout. CLGET_RETRY_TIMEOUT struct timevalGets the retry timeout. 8 January 1992
rpc(3N) rpc(3N)If you use CLSET_TIMEOUT, the timeout parameter passed to clnt_call() is ignored in all future calls. CLSET_RETRY_TIMEOUT and CLGET_RETRY_TIMEOUT are valid for UDP operations only. 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 and External Data Representation (XDR) software 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() is a macro that copies the error structure out of the client handle to the structure at address errp. clnt_createerror() prints 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. This function is 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. This function is used after a call to clnt_call(). clnt_spcreateerror() is similar to clnt_pcreateerror() except that it returns a string instead of printing to the standard error. This routine 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, returns a pointer to a string which contains the message. The string ends with a newline character. 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), 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. Unlike clnt_sperror() and clnt_spcreaterror(), clnt_sperrno() does not return pointer to static data so the result is not overwritten on each call. January 1992 9
rpc(3N) rpc(3N)clnt_sperror() is similar to clnt_perror() except that (like clnt_sperrno()) it returns a string instead of printing to standard error. This routine returns pointer to static data that is overwritten on each call. clntraw_create() creates a toy RPC client for the remote program prognum, version versnum. The transport used to pass messages 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 acquisition of RPC overheads, such as round trip times, without any kernel interference. This routine returns NULL if it fails. clnttcp_create() 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 0, it is set to the actual port that the remote program is listening on (the remote portmap service is consulted for this information). The parameter sockp is a socket; if it is RPC_ANYSOCK, this routine opens a new one and sets sockp. Because TCP-based RPC uses buffered I/O, 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. clntudp_create() creates an RPC client for the remote program prognum, version versnum; the client uses use UDP/IP as a transport. The remote program is located at Internet address addr. If addr->sin_port is 0, it is set to actual port that the remote program is listening on (the remote portmap service is consulted for this information). The parameter sockp is a socket; if it is RPC_ANYSOCK, this routine opens a new one and sets sockp. The UDP transport resends the call message 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(). Warning: because 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. host2netname() converts from a domain-specific hostname to an operating-system independent netname. Returns TRUE if it succeeds and FALSE if it fails. This function is the inverse of netname2host(). get_myaddress() puts the machine's IP address into *addr without consulting the library routines that deal with /etc/hosts. The port number is always set to 10 January 1992
rpc(3N) rpc(3N)htons(PMAPPORT). getnetname() installs the unique, operating-system independent netname of the caller in the fixed-length array name. This function returns TRUE if it succeeds and FALSE if it fails. netname2host() converts from an operating-system independent netname to a domain-specific hostname. This function returns TRUE if it succeeds and FALSE if it fails. This function is inverse of host2netname(). netname2user() converts from an operating-system independent netname to a domain-specific user ID. Returns TRUE if it succeeds and FALSE if it fails. This function is the inverse of user2netname(). pmap_getmaps() is a user interface to the portmap service that 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 service that returns the port number on which waits a service that supports program number prognum, version versnum, and speaks the transport protocol associated with protocol. The value of protocol is most likely IPPROTO_UDP or IPPROTO_TCP. A return value of 0 means that the mapping does not exist or that the RPC system failed to contact the remote portmap service. In the latter case, the global variable rpc_createerr() contains the RPC status. pmap_rmtcall() is a user interface to the portmap service that instructs portmap running on the host specified by the IP address *addr to make an RPC call on your behalf to a procedure on that host. The parameter *portp is modified to the program's port number if the procedure succeeds. The definitions 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 service that establishes a mapping between the triple [prognum,versnum,protocol] and port on the computer's portmap service. The value of protocol is most likely IPPROTO_UDP or IPPROTO_TCP. This routine returns 1 if it succeeds, 0 otherwise. This routine is automatically called by svc_register(). pmap_unset() is a user interface to the portmap service that destroys all mapping between the triple [prognum,versnum,*] January 1992 11
rpc(3N) rpc(3N)and ports on the computer's portmap service. This routine returns 1 if it succeeds, 0 otherwise. registerrpc() registers the 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 parameters; progname should return a pointer to its static results; inproc is used to decode the parameters while outproc is used to encode the results. This routine returns 0 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 structures, including xprt itself. Use of xprt is undefined after calling this routine. svd_fdset is a global variable reflecting the RPC service side's read file descriptor bit mask; it is suitable as a parameter to the select system call. This is only of interest if a service implementor does not call svc_run(), but rather does his or her own asynchronous event processing. This variable is read-only and its address should not be passed to select(2N), yet it may change after calls to svc_getreqset() or any creation routines. svc_fds is similar to svc_fedset() but is limited to 32 descriptors. This interface is made obsolete 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 0 otherwise. svc_getargs() is a macro that decodes the arguments of an RPC request associated with the RPC service transport handle, xprt. The parameter in is the address where the arguments are to be placed; inproc is the XDR routine used to decode the arguments. This routine returns 1 if decoding succeeds, and 0 otherwise. svc_getcaller() is the approved way of getting the network address of the caller of a procedure associated with the RPC 12 January 1992
rpc(3N) rpc(3N)service transport handle, xprt. svc_getreqset() is only of interest if a service implementor does not call svc_run(), but instead implements custom asynchronous event processing. It is called when select(2N) has determined that an RPC request has arrived on some RPC sockets; rdfds is the resultant read file descriptor bit mask. The routine returns when all sockets associated with the value of rdfds have been serviced. svc_getreq() is similar to svc_getreqset() but is limited to 32 descriptors. This interface is made obsolete by svc_getreqset(). svc_register() associates prognum and versnum with the service dispatch procedure specified by dispatch. If protocol is 0, the service is not registered with the portmap service. If protocol is non-zero, a mapping of the triple [prognum,versnum,protocol] to xprt->xp_port is established with the local portmap service (generally protocol is 0, IPPROTO_UDP or IPPROTO_TCP). The procedure dispatch has the following form: dispatch(request, xprt) struct svc_req *request; SVCXPRT *xprt; The svc_register() routine returns 1 if it succeeds, and 0 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(2N) 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 request's associated transport handle; outproc is the XDR routine that is used to encode the results; and out is the address of the results. This routine returns 1 if it succeeds, 0 otherwise. svc_unregister() removes all mapping of the double [prognum,versnum] to dispatch routines, and of the triple [prognum,versnum,*] to port number. 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 successfully decode its parameters. See also January 1992 13
rpc(3N) rpc(3N)svc_getargs(). svcerr_noproc() is called by a service dispatch routine that does not implement 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 detects a system error not covered by any particular protocol. For example, if a service can no longer allocate storage, it may call this routine. svcerr_weakauth() is called by a service dispatch routine that refuses to perform a remote procedure call due to insufficient (but correct) authentication parameters. The routine calls svcerr_auth(xprt, AUTH_TOOWEAK). svcraw_create() 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 use 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() 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 socket is created. If the socket is not bound to a local TCP port, 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. Because TCP-based RPC uses buffered I/O, users may specify the size of buffers; values of 0 choose suitable defaults. svcfd_create() creates a service on top of any open descriptor. Typically, this descriptor is a connected socket for a stream protocol such as TCP. The parameters sendsize and recvsize indicate sizes for the send and receive buffers. If they are 0, a reasonable default is chosen. svcudp_create() creates a UDP/IP-based RPC service transport to which it returns a pointer. The transport is associated 14 January 1992
rpc(3N) rpc(3N)with the socket sock, which may be RPC_ANYSOCK, in which case a new socket is created. If the socket is not bound to a local UDP port, 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. Warning: because 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. user2netname() converts from a domain-specific username to an operating-system independent netname. This function returns TRUE if it succeeds and FALSE if it fails. This function is the inverse of netname2user(). xdr_accepted_reply() is used for encoding RPC reply messages. This routine 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 routine is useful for users who wish to generate these credentials without using the RPC authentication package. xdr_callhdr() is used for describing call header messages. This routine 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 externally describing parameters to various portmap procedures. This routine is useful for users who wish to generate these parameters without using the pmap interface. xdr_pmaplist() is used for externally describing a list of port mappings. This routine is useful for users who wish to generate these parameters 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 without using the RPC package. January 1992 15
rpc(3N) rpc(3N)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() modifies the global variable svc_fds() to register an RPC service transport handle with the RPC service package, which must be done after an RPC service transport handle is created. Service implementors usually do not need this routine. xprt_unregister() modifies the global variable svc_fds() to unregister an RPC service transport handle from the RPC service package, which must be done before an RPC service transport handle is destroyed. Service implementors usually do not need this routine. SEE ALSO xdr(3N) A/UX Network Applications Programming 16 January 1992