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.\" @(#)rpc.3n  2.4 88/08/08 4.0 RPCSRC; from 1.19 88/06/24 SMI
.\" $FreeBSD: src/lib/libc/rpc/rpc.3,v 1.11 2000/03/02 09:13:47 sheldonh Exp $
.\"
.TH RPC 3 "16 February 1988"
.SH NAME
rpc \- library routines for remote procedure calls
.SH SYNOPSIS AND 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.
.LP
Routines that are used for Secure RPC (DES authentication) are described in
.BR rpc_secure (3).
Secure RPC can be used only if DES encryption is available.
.LP
.ft B
.nf
.sp .5
#include <rpc/rpc.h>
.fi
.ft R
.br
.if t .ne 8
.LP
.ft B
.nf
.sp .5
void
auth_destroy(auth)
\s-1AUTH\s0 *auth;
.fi
.ft R
.IP
A macro that destroys the authentication information associated with
.IR auth .
Destruction usually involves deallocation of private data
structures.
The use of
.I auth
is undefined after calling
.BR auth_destroy(\|) .
.br
.if t .ne 6
.LP
.ft B
.nf
.sp .5
\s-1AUTH\s0 *
authnone_create(\|)
.fi
.ft R
.IP
Create and returns an
.SM RPC
authentication handle that passes nonusable authentication
information with each remote procedure call.
This is the
default authentication used by
.SM RPC.
.if t .ne 10
.LP
.ft B
.nf
.sp .5
\s-1AUTH\s0 *
authunix_create(host, uid, gid, len, aup_gids)
char *host;
int uid, gid, len, *aup.gids;
.fi
.ft R
.IP
Create and return an
.SM RPC
authentication handle that contains
.UX
authentication information.
The parameter
.I host
is the name of the machine on which the information was
created;
.I uid
is the user's user
.SM ID ;
.I gid
is the user's current group
.SM ID ;
.I len
and
.I aup_gids
refer to a counted array of groups to which the user belongs.
It is easy to impersonate a user.
.br
.if t .ne 5
.LP
.ft B
.nf
.sp .5
\s-1AUTH\s0 *
authunix_create_default(\|)
.fi
.ft R
.IP
Calls
.B authunix_create(\|)
with the appropriate parameters.
.br
.if t .ne 13
.LP
.ft B
.nf
.sp .5
callrpc(host, prognum, versnum, procnum, inproc, in, outproc, out)
char *host;
u_long prognum, versnum, procnum;
char *in, *out;
xdrproc_t inproc, outproc;
.fi
.ft R
.IP
Call the remote procedure associated with
.IR prognum ,
.IR versnum ,
and
.I procnum
on the machine,
.IR host .
The parameter
.I in
is the address of the procedure's argument(s), and
.I out
is the address of where to place the result(s);
.I inproc
is used to encode the procedure's parameters, and
.I outproc
is used to decode the procedure's results.
This routine returns zero if it succeeds, or the value of
.B "enum clnt_stat"
cast to an integer if it fails.
The routine
.B clnt_perrno(\|)
is handy for translating failure statuses into messages.
.IP
Warning: calling remote procedures with this routine
uses
.SM UDP/IP
as a transport; see
.B clntudp_create(\|)
for restrictions.
You do not have control of timeouts or authentication using
this routine.
.br
.if t .ne 16
.LP
.ft B
.nf
.sp .5
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;
.fi
.ft R
.IP
Like
.BR callrpc(\|) ,
except the call message is broadcast to all locally
connected broadcast nets.
Each time it receives a
response, this routine calls
.BR eachresult(\|) ,
whose form is:
.IP
.RS 1i
.ft B
.nf
eachresult(out, addr)
char *out;
struct sockaddr_in *addr;
.ft R
.fi
.RE
.IP
where
.I out
is the same as
.I out
passed to
.BR clnt_broadcast(\|) ,
except that the remote procedure's output is decoded there;
.I addr
points to the address of the machine that sent the results.
If
.B eachresult(\|)
returns zero,
.B clnt_broadcast(\|)
waits for more replies; otherwise it returns with appropriate
status.
.IP
Warning: broadcast sockets are limited in size to the
maximum transfer unit of the data link.
For ethernet,
this value is 1500 bytes.
.br
.if t .ne 13
.LP
.ft B
.nf
.sp .5
enum clnt_stat
clnt_call(clnt, procnum, inproc, in, outproc, out, tout)
\s-1CLIENT\s0 *clnt;
u_long
procnum;
xdrproc_t inproc, outproc;
char *in, *out;
struct timeval tout;
.fi
.ft R
.IP
A macro that calls the remote procedure
.I procnum
associated with the client handle,
.IR clnt ,
which is obtained with an
.SM RPC
client creation routine such as
.BR clnt_create(\|) .
The parameter
.I in
is the address of the procedure's argument(s), and
.I out
is the address of where to place the result(s);
.I inproc
is used to encode the procedure's parameters, and
.I outproc
is used to decode the procedure's results;
.I tout
is the time allowed for results to come back.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
clnt_destroy(clnt)
\s-1CLIENT\s0 *clnt;
.fi
.ft R
.IP
A macro that destroys the client's
.SM RPC
handle.
Destruction usually involves deallocation
of private data structures, including
.I clnt
itself.  Use of
.I clnt
is undefined after calling
.BR clnt_destroy(\|) .
If the
.SM RPC
library opened the associated socket, it will close it also.
Otherwise, the socket remains open.
.br
.if t .ne 10
.LP
.ft B
.nf
.sp .5
\s-1CLIENT\s0 *
clnt_create(host, prog, vers, proto)
char *host;
u_long prog, vers;
char *proto;
.fi
.ft R
.IP
Generic client creation routine.
.I host
identifies the name of the remote host where the server
is located.
.I proto
indicates which kind of transport protocol to use.
The
currently supported values for this field are \(lqudp\(rq
and \(lqtcp\(rq.
Default timeouts are set, but can be modified using
.BR clnt_control(\|) .
.IP
Warning: Using
.SM UDP
has its shortcomings.  Since
.SM UDP\s0-based
.SM 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.
.br
.if t .ne 10
.LP
.ft B
.nf
.sp .5
bool_t
clnt_control(cl, req, info)
\s-1CLIENT\s0 *cl;
u_int req;
char *info;
.fi
.ft R
.IP
A macro used to change or retrieve various information
about a client object.
.I req
indicates the type of operation, and
.I info
is a pointer to the information.
For both
.SM UDP
and
.SM TCP\s0,
the supported values of
.I req
and their argument types and what they do are:
.IP
.nf
.ta +2.0i +2.0i +2.0i
.SM CLSET_TIMEOUT\s0    struct timeval  set total timeout
.SM CLGET_TIMEOUT\s0    struct timeval  get total timeout
.fi
.IP
Note: if you set the timeout using
.BR clnt_control(\|) ,
the timeout parameter passed to
.B clnt_call(\|)
will be ignored in all future calls.
.IP
.nf
.SM CLGET_SERVER_ADDR\s0        struct sockaddr_in      get server's address
.fi
.br
.IP
The following operations are valid for
.SM UDP
only:
.IP
.nf
.ta +2.0i ; +2.0i ; +2.0i
.SM CLSET_RETRY_TIMEOUT\s0              struct timeval  set the retry timeout
.SM CLGET_RETRY_TIMEOUT\s0              struct timeval  get the retry timeout
.fi
.br
.IP
The retry timeout is the time that
.SM "UDP RPC"
waits for the server to reply before
retransmitting the request.
.br
.if t .ne 10
.LP
.ft B
.nf
.sp .5
clnt_freeres(clnt, outproc, out)
\s-1CLIENT\s0 *clnt;
xdrproc_t outproc;
char *out;
.fi
.ft R
.IP
A macro that frees any data allocated by the
.SM RPC/XDR
system when it decoded the results of an
.SM RPC
call.  The
parameter
.I out
is the address of the results, and
.I outproc
is the
.SM XDR
routine describing the results.
This routine returns one if the results were successfully
freed,
and zero otherwise.
.br
.if t .ne 6
.LP
.ft B
.nf
.sp .5
void
clnt_geterr(clnt, errp)
\s-1CLIENT\s0 *clnt;
struct rpc_err *errp;
.fi
.ft R
.IP
A macro that copies the error structure out of the client
handle
to the structure at address
.IR errp .
.br
.if t .ne 8
.LP
.ft B
.nf
.sp .5
void
clnt_pcreateerror(s)
char *s;
.fi
.ft R
.IP
Print a message to standard error indicating
why a client
.SM RPC
handle could not be created.
The message is prepended with string
.I s
and a colon.
Used when a
.BR clnt_create(\|) ,
.BR clntraw_create(\|) ,
.BR clnttcp_create(\|) ,
or
.B clntudp_create(\|)
call fails.
.br
.if t .ne 8
.LP
.ft B
.nf
.sp .5
void
clnt_perrno(stat)
enum clnt_stat stat;
.fi
.ft R
.IP
Print a message to standard error corresponding
to the condition indicated by
.IR stat .
Used after
.BR callrpc(\|) .
.br
.if t .ne 8
.LP
.ft B
.nf
.sp .5
clnt_perror(clnt, s)
\s-1CLIENT\s0 *clnt;
char *s;
.fi
.ft R
.IP
Print a message to standard error indicating why an
.SM RPC
call failed;
.I clnt
is the handle used to do the call.
The message is prepended with string
.I s
and a colon.
Used after
.BR clnt_call(\|) .
.br
.if t .ne 9
.LP
.ft B
.nf
.sp .5
char *
clnt_spcreateerror
char *s;
.fi
.ft R
.IP
Like
.BR clnt_pcreateerror(\|) ,
except that it returns a string
instead of printing to the standard error.
.IP
Bugs: returns pointer to static data that is overwritten
on each call.
.br
.if t .ne 9
.LP
.ft B
.nf
.sp .5
char *
clnt_sperrno(stat)
enum clnt_stat stat;
.fi
.ft R
.IP
Take the same arguments as
.BR clnt_perrno(\|) ,
but instead of sending a message to the standard error
indicating why an
.SM RPC
call failed, return a pointer to a string which contains
the message.  The string ends with a
.SM NEWLINE\s0.
.IP
.B clnt_sperrno(\|)
is used instead of
.B 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
.BR printf ,
or if a message format different from that supported by
.B clnt_perrno(\|)
is to be used.
Note: unlike
.B clnt_sperror(\|)
and
.BR clnt_spcreaterror(\|) ,
.B clnt_sperrno(\|)
returns pointer to static data, but the
result will not get overwritten on each call.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
char *
clnt_sperror(rpch, s)
\s-1CLIENT\s0 *rpch;
char *s;
.fi
.ft R
.IP
Like
.BR clnt_perror(\|) ,
except that (like
.BR clnt_sperrno(\|) )
it returns a string instead of printing to standard error.
.IP
Bugs: returns pointer to static data that is overwritten
on each call.
.br
.if t .ne 10
.LP
.ft B
.nf
.sp .5
\s-1CLIENT\s0 *
clntraw_create(prognum, versnum)
u_long prognum, versnum;
.fi
.ft R
.IP
This routine creates a toy
.SM RPC
client for the remote program
.IR prognum ,
version
.IR versnum .
The transport used to pass messages to the service is
actually a buffer within the process's address space, so the
corresponding
.SM RPC
server should live in the same address space; see
.BR svcraw_create(\|) .
This allows simulation of
.SM RPC
and acquisition of
.SM RPC
overheads, such as round trip times, without any
kernel interference.
This routine returns
.SM NULL
if it fails.
.br
.if t .ne 15
.LP
.ft B
.nf
.sp .5
\s-1CLIENT\s0 *
clnttcp_create(addr, prognum, versnum, sockp, sendsz, recvsz)
struct sockaddr_in *addr;
u_long prognum, versnum;
int *sockp;
u_int sendsz, recvsz;
.fi
.ft R
.IP
This routine creates an
.SM RPC
client for the remote program
.IR prognum ,
version
.IR versnum ;
the client uses
.SM TCP/IP
as a transport.
The remote program is located at Internet
address
.IR *addr .
If
.\"The following in-line font conversion is necessary for the hyphen indicator
\fB\%addr\->sin_port\fR
is zero, then it is set to the actual port that the remote
program is listening on (the remote
.B portmap
service is consulted for this information). The parameter
.I sockp
is a socket; if it is
.BR \s-1RPC_ANYSOCK\s0 ,
then this routine opens a new one and sets
.IR sockp .
Since
.SM TCP\s0-based
.SM RPC
uses buffered
.SM I/O ,
the user may specify the size of the send and receive buffers
with the parameters
.I sendsz
and
.IR recvsz ;
values of zero choose suitable defaults.
This routine returns
.SM NULL
if it fails.
.br
.if t .ne 15
.LP
.ft B
.nf
.sp .5
\s-1CLIENT\s0 *
clntudp_create(addr, prognum, versnum, wait, sockp)
struct sockaddr_in *addr;
u_long prognum, versnum;
struct timeval wait;
int *sockp;
.fi
.ft R
.IP
This routine creates an
.SM RPC
client for the remote program
.IR prognum ,
version
.IR versnum ;
the client uses
.SM UDP/IP
as a transport.
The remote program is located at Internet
address
.IR addr .
If
\fB\%addr\->sin_port\fR
is zero, then it is set to actual port that the remote
program is listening on (the remote
.B portmap
service is consulted for this information). The parameter
.I sockp
is a socket; if it is
.BR \s-1RPC_ANYSOCK\s0 ,
then this routine opens a new one and sets
.IR sockp .
The
.SM UDP
transport resends the call message in intervals of
.B 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
.BR clnt_call(\|) .
.IP
Warning: since
.SM UDP\s0-based
.SM 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.
.br
.if t .ne 8
.LP
.ft B
.nf
.sp .5
\s-1CLIENT\s0 *
clntudp_bufcreate(addr, prognum, versnum, wait, sockp, sendsize, recosize)
struct sockaddr_in *addr;
u_long prognum, versnum;
struct timeval wait;
int *sockp;
unsigned int sendsize;
unsigned int recosize;
.fi
.ft R
.IP
This routine creates an
.SM RPC
client for the remote program
.IR prognum ,
on
.IR versnum ;
the client uses
.SM UDP/IP
as a transport.
The remote program is located at Internet
address
.IR addr .
If
\fB\%addr\->sin_port\fR
is zero, then it is set to actual port that the remote
program is listening on (the remote
.B portmap
service is consulted for this information). The parameter
.I sockp
is a socket; if it is
.BR \s-1RPC_ANYSOCK\s0 ,
then this routine opens a new one and sets
.BR sockp .
The
.SM UDP
transport resends the call message in intervals of
.B 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
.BR clnt_call(\|) .
.IP
This allows the user to specify the maximum packet size for sending and receiving 
.SM UDP\s0-based
.SM RPC
messages.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
int
get_myaddress(addr)
struct sockaddr_in *addr;
.fi
.ft R
.IP
Stuff the machine's
.SM IP
address into
.IR *addr ,
without consulting the library routines that deal with
.BR /etc/hosts .
The port number is always set to
.BR htons(\s-1PMAPPORT\s0) .
Returns zero on success, non-zero on failure.
.br
.if t .ne 10
.LP
.ft B
.nf
.sp .5
struct pmaplist *
pmap_getmaps(addr)
struct sockaddr_in *addr;
.fi
.ft R
.IP
A user interface to the
.B portmap
service, which returns a list of the current
.SM RPC
program-to-port mappings
on the host located at
.SM IP
address
.IR *addr .
This routine can return
.SM NULL .
The command
.RB ` "rpcinfo \-p" '
uses this routine.
.br
.if t .ne 12
.LP
.ft B
.nf
.sp .5
u_short
pmap_getport(addr, prognum, versnum, protocol)
struct sockaddr_in *addr;
u_long prognum, versnum, protocol;
.fi
.ft R
.IP
A user interface to the
.B portmap
service, which returns the port number
on which waits a service that supports program number
.IR prognum ,
version
.IR versnum ,
and speaks the transport protocol associated with
.IR protocol .
The value of
.I protocol
is most likely
.B
.SM IPPROTO_UDP
or 
.BR \s-1IPPROTO_TCP\s0 .
A return value of zero means that the mapping does not exist
or that
the
.SM RPC
system failed to contact the remote
.B portmap
service.  In the latter case, the global variable
.B rpc_createerr(\|)
contains the
.SM RPC
status.
.br
.if t .ne 15
.LP
.ft B
.nf
.sp .5
enum clnt_stat
pmap_rmtcall(addr, prognum, versnum, procnum, inproc, in, outproc, out, tout, portp)
struct sockaddr_in *addr;
u_long prognum, versnum, procnum;
char *in, *out;
xdrproc_t inproc, outproc;
struct timeval tout;
u_long *portp;
.fi
.ft R
.IP
A user interface to the
.B portmap
service, which instructs
.B portmap
on the host at
.SM IP
address
.I *addr
to make an
.SM RPC
call on your behalf to a procedure on that host.
The parameter
.I *portp
will be modified to the program's port number if the
procedure
succeeds.
The definitions of other parameters are discussed
in
.B callrpc(\|)
and
.BR clnt_call(\|) .
This procedure should be used for a \(lqping\(rq and nothing
else.
See also
.BR clnt_broadcast(\|) .
.br
.if t .ne 9
.LP
.ft B
.nf
.sp .5
pmap_set(prognum, versnum, protocol, port)
u_long prognum, versnum, protocol;
u_short port;
.fi
.ft R
.IP
A user interface to the
.B portmap
service, which establishes a mapping between the triple
.RI [ prognum , versnum , protocol\fR]
and
.I port
on the machine's
.B portmap
service.
The value of
.I protocol
is most likely
.B
.SM IPPROTO_UDP
or 
.BR \s-1IPPROTO_TCP\s0 .
This routine returns one if it succeeds, zero otherwise.
Automatically done by
.BR svc_register(\|) .
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
pmap_unset(prognum, versnum)
u_long prognum, versnum;
.fi
.ft R
.IP
A user interface to the
.B portmap
service, which destroys all mapping between the triple
.RI [ prognum , versnum , *\fR]
and
.B ports
on the machine's
.B portmap
service.
This routine returns one if it succeeds, zero
otherwise.
.br
.if t .ne 15
.LP
.ft B
.nf
.sp .5
registerrpc(prognum, versnum, procnum, procname, inproc, outproc)
u_long prognum, versnum, procnum;
char *(*procname) (\|) ;
xdrproc_t inproc, outproc;
.fi
.ft R
.IP
Register procedure
.I procname
with the
.SM RPC
service package.  If a request arrives for program
.IR prognum ,
version
.IR versnum ,
and procedure
.IR procnum ,
.I procname
is called with a pointer to its parameter(s);
.I progname
should return a pointer to its static result(s);
.I inproc
is used to decode the parameters while
.I outproc
is used to encode the results.
This routine returns zero if the registration succeeded, \-1
otherwise.
.IP
Warning: remote procedures registered in this form
are accessed using the
.SM UDP/IP
transport; see
.B svcudp_create(\|)
for restrictions.
.br
.if t .ne 5
.LP
.ft B
.nf
.sp .5
struct rpc_createerr     rpc_createerr;
.fi
.ft R
.IP
A global variable whose value is set by any
.SM RPC
client creation routine
that does not succeed.  Use the routine
.B clnt_pcreateerror(\|)
to print the reason why.
.if t .ne 7
.LP
.ft B
.nf
.sp .5
svc_destroy(xprt)
\s-1SVCXPRT\s0 *
xprt;
.fi
.ft R
.IP
A macro that destroys the
.SM RPC
service transport handle,
.IR xprt .
Destruction usually involves deallocation
of private data structures, including
.I xprt
itself.  Use of
.I xprt
is undefined after calling this routine.
.br
.if t .ne 8
.LP
.ft B
.nf
.sp .5
fd_set svc_fdset;
.fi
.ft R
.IP
A global variable reflecting the
.SM RPC
service side's
read file descriptor bit mask; it is suitable as a template parameter
to the
.B select
system call.
This is only of interest
if a service implementor does not call
.BR svc_run(\|) ,
but rather does his own asynchronous event processing.
This variable is read-only (do not pass its address to
.BR select !),
yet it may change after calls to
.B svc_getreqset(\|)
or any creation routines.
.br
As well, note that if the process has descriptor limits
which are extended beyond
.BR FD_SETSIZE ,
this variable will only be usable for the first
.BR FD_SETSIZE
descriptors.
.br
.if t .ne 6
.LP
.ft B
.nf
.sp .5
int svc_fds;
.fi
.ft R
.IP
Similar to
.BR svc_fedset(\|) ,
but limited to 32 descriptors.
This
interface is obsoleted by
.BR svc_fdset(\|) .
.br
.if t .ne 9
.LP
.ft B
.nf
.sp .5
svc_freeargs(xprt, inproc, in)
\s-1SVCXPRT\s0 *xprt;
xdrproc_t inproc;
char *in;
.fi
.ft R
.IP
A macro that frees any data allocated by the
.SM RPC/XDR
system when it decoded the arguments to a service procedure
using
.BR svc_getargs(\|) .
This routine returns 1 if the results were successfully
freed,
and zero otherwise.
.br
.if t .ne 10
.LP
.ft B
.nf
.sp .5
svc_getargs(xprt, inproc, in)
\s-1SVCXPRT\s0 *xprt;
xdrproc_t inproc;
char *in;
.fi
.ft R
.IP
A macro that decodes the arguments of an
.SM RPC
request
associated with the
.SM RPC
service transport handle,
.IR xprt .
The parameter
.I in
is the address where the arguments will be placed;
.I inproc
is the
.SM XDR
routine used to decode the arguments.
This routine returns one if decoding succeeds, and zero
otherwise.
.br
.if t .ne 9
.LP
.ft B
.nf
.sp .5
struct sockaddr_in *
svc_getcaller(xprt)
\s-1SVCXPRT\s0 *xprt;
.fi
.ft R
.IP
The approved way of getting the network address of the caller
of a procedure associated with the
.SM RPC
service transport handle,
.IR xprt .
.br
.if t .ne 9
.LP
.ft B
.nf
.sp .5
svc_getreqset(rdfds)
fd_set *rdfds;
.fi
.ft R
.IP
This routine is only of interest if a service implementor
does not call
.BR svc_run(\|) ,
but instead implements custom asynchronous event processing.
It is called when the
.B select
system call has determined that an
.SM RPC
request has arrived on some
.SM RPC
.B socket(s) ;
.I rdfds
is the resultant read file descriptor bit mask.
The routine returns when all sockets associated with the
value of
.I rdfds
have been serviced.
.br
.if t .ne 6
.LP
.ft B
.nf
.sp .5
svc_getreq(rdfds)
int rdfds;
.fi
.ft R
.IP
Similar to
.BR svc_getreqset(\|) ,
but limited to 32 descriptors.
This interface is obsoleted by
.BR svc_getreqset(\|) .
.br
.if t .ne 17
.LP
.ft B
.nf
.sp .5
svc_register(xprt, prognum, versnum, dispatch, protocol)
\s-1SVCXPRT\s0 *xprt;
u_long prognum, versnum;
void (*dispatch) (\|);
u_long protocol;
.fi
.ft R
.IP
Associates
.I prognum
and
.I versnum
with the service dispatch procedure,
.IR dispatch .
If
.I protocol
is zero, the service is not registered with the
.B portmap
service.  If
.I protocol
is non-zero, then a mapping of the triple
.RI [ prognum , versnum , protocol\fR]
to
\fB\%xprt\->xp_port\fR
is established with the local
.B portmap
service (generally
.I protocol
is zero,
.B
.SM IPPROTO_UDP
or 
.B
.SM IPPROTO_TCP
).
The procedure
.I dispatch
has the following form:
.RS 1i
.ft B
.nf
dispatch(request, xprt)
struct svc_req *request;
\s-1SVCXPRT\s0 *xprt;
.ft R
.fi
.RE
.IP
The
.B svc_register(\|)
routine returns one if it succeeds, and zero otherwise.
.br
.if t .ne 6
.LP
.ft B
.nf
.sp .5
svc_run(\|)
.fi
.ft R
.IP
This routine never returns.
It waits for
.SM RPC
requests to arrive, and calls the appropriate service
procedure using
.B svc_getreq(\|)
when one arrives.
This procedure is usually waiting for a
.B select(\|)
system call to return.
.br
.if t .ne 9
.LP
.ft B
.nf
.sp .5
svc_sendreply(xprt, outproc, out)
\s-1SVCXPRT\s0 *xprt;
xdrproc_t outproc;
char *out;
.fi
.ft R
.IP
Called by an
.SM RPC
service's dispatch routine to send the results of a
remote procedure call.  The parameter
.I xprt
is the request's associated transport handle;
.I outproc
is the
.SM XDR
routine which is used to encode the results; and
.I out
is the address of the results.
This routine returns one if it succeeds, zero otherwise.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
void
svc_unregister(prognum, versnum)
u_long prognum, versnum;
.fi
.ft R
.IP
Remove all mapping of the double
.RI [ prognum , versnum ]
to dispatch routines, and of the triple
.RI [ prognum , versnum , *\fR]
to port number.
.br
.if t .ne 9
.LP
.ft B
.nf
.sp .5
void
svcerr_auth(xprt, why)
\s-1SVCXPRT\s0 *xprt;
enum auth_stat why;
.fi
.ft R
.IP
Called by a service dispatch routine that refuses to perform
a remote procedure call due to an authentication error.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
void
svcerr_decode(xprt)
\s-1SVCXPRT\s0 *xprt;
.fi
.ft R
.IP
Called by a service dispatch routine that cannot successfully
decode its parameters.
See also
.BR svc_getargs(\|) .
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
void
svcerr_noproc(xprt)
\s-1SVCXPRT\s0 *xprt;
.fi
.ft R
.IP
Called by a service dispatch routine that does not implement
the procedure number that the caller requests.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
void
svcerr_noprog(xprt)
\s-1SVCXPRT\s0 *xprt;
.fi
.ft R
.IP
Called when the desired program is not registered with the
.SM RPC
package.
Service implementors usually do not need this routine.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
void
svcerr_progvers(xprt)
\s-1SVCXPRT\s0 *xprt;
.fi
.ft R
.IP
Called when the desired version of a program is not registered
with the
.SM RPC
package.
Service implementors usually do not need this routine.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
void
svcerr_systemerr(xprt)
\s-1SVCXPRT\s0 *xprt;
.fi
.ft R
.IP
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.
.br
.if t .ne 8
.LP
.ft B
.nf
.sp .5
void
svcerr_weakauth(xprt)
\s-1SVCXPRT\s0 *xprt;
.fi
.ft R
.IP
Called by a service dispatch routine that refuses to perform
a remote procedure call due to insufficient
authentication parameters.  The routine calls
.BR "svcerr_auth(xprt, \s-1AUTH_TOOWEAK\s0)" .
.br
.if t .ne 11
.LP
.ft B
.nf
.sp .5
\s-1SVCXPRT\s0 *
svcraw_create(\|)
.fi
.ft R
.IP
This routine creates a toy
.SM RPC
service transport, to which it returns a pointer.  The
transport
is really a buffer within the process's address space,
so the corresponding
.SM RPC
client should live in the same
address space;
see
.BR clntraw_create(\|) .
This routine allows simulation of
.SM RPC
and acquisition of
.SM RPC
overheads (such as round trip times), without any kernel
interference.
This routine returns
.SM NULL
if it fails.
.br
.if t .ne 11
.LP
.ft B
.nf
.sp .5
\s-1SVCXPRT\s0 *
svctcp_create(sock, send_buf_size, recv_buf_size)
int sock;
u_int send_buf_size, recv_buf_size;
.fi
.ft R
.IP
This routine creates a
.SM TCP/IP\s0-based
.SM RPC
service transport, to which it returns a pointer.
The transport is associated with the socket
.IR sock ,
which may be
.BR \s-1RPC_ANYSOCK\s0 ,
in which case a new socket is created.
If the socket is not bound to a local
.SM TCP
port, then this routine binds it to an arbitrary port.  Upon
completion,
\fB\%xprt\->xp_sock\fR
is the transport's socket descriptor, and
\fB\%xprt\->xp_port\fR
is the transport's port number.
This routine returns
.SM NULL
if it fails.
Since
.SM TCP\s0-based
.SM RPC
uses buffered
.SM I/O ,
users may specify the size of buffers; values of zero
choose suitable defaults.
.br
.if t .ne 11
.LP
.ft B
.nf
.sp .5
\s-1SVCXPRT\s0 *
svcfd_create(fd, sendsize, recvsize)
int fd;
u_int sendsize;
u_int recvsize;
.fi
.ft R
.IP
Create a service on top of any open descriptor.
Typically,
this
descriptor is a connected socket for a stream protocol such
as
.SM TCP\s0.
.I sendsize
and
.I recvsize
indicate sizes for the send and receive buffers.  If they are
zero, a reasonable default is chosen.
.br
.if t .ne 10
.LP
.ft B
.nf
.sp .5
\s-1SVCXPRT\s0 *
svcudp_bufcreate(sock, sendsize, recosize)
int sock;
.fi
.ft R
.IP
This routine creates a
.SM UDP/IP\s0-based
.SM RPC
service transport, to which it returns a pointer.
The transport is associated with the socket
.IR sock ,
which may be
.B \s-1RPC_ANYSOCK\s0 ,
in which case a new socket is created.
If the socket is not bound to a local
.SM UDP
port, then this routine binds it to an arbitrary port.
Upon
completion,
\fB\%xprt\->xp_sock\fR
is the transport's socket descriptor, and
\fB\%xprt\->xp_port\fR
is the transport's port number.
This routine returns
.SM NULL
if it fails.
.IP
This allows the user to specify the maximum packet size for sending and 
receiving
.SM UDP\s0-based
.SM RPC messages.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
xdr_accepted_reply(xdrs, ar)
\s-1XDR\s0 *xdrs;
struct accepted_reply *ar;
.fi
.ft R
.IP
Used for encoding
.SM RPC
reply messages.
This routine is useful for users who
wish to generate
\s-1RPC\s0-style
messages without using the
.SM RPC
package.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
xdr_authunix_parms(xdrs, aupp)
\s-1XDR\s0 *xdrs;
struct authunix_parms *aupp;
.fi
.ft R
.IP
Used for describing
.SM UNIX
credentials.
This routine is useful for users
who wish to generate these credentials without using the
.SM RPC
authentication package.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
void
xdr_callhdr(xdrs, chdr)
\s-1XDR\s0 *xdrs;
struct rpc_msg *chdr;
.fi
.ft R
.IP
Used for describing
.SM RPC
call header messages.
This routine is useful for users who wish to generate
.SM RPC\s0-style
messages without using the
.SM RPC
package.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
xdr_callmsg(xdrs, cmsg)
\s-1XDR\s0 *xdrs;
struct rpc_msg *cmsg;
.fi
.ft R
.IP
Used for describing
.SM RPC
call messages.
This routine is useful for users who wish to generate
.SM RPC\s0-style
messages without using the
.SM RPC
package.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
xdr_opaque_auth(xdrs, ap)
\s-1XDR\s0 *xdrs;
struct opaque_auth *ap;
.fi
.ft R
.IP
Used for describing
.SM RPC
authentication information messages.
This routine is useful for users who wish to generate
.SM RPC\s0-style
messages without using the
.SM RPC
package.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
xdr_pmap(xdrs, regs)
\s-1XDR\s0 *xdrs;
struct pmap *regs;
.fi
.ft R
.IP
Used for describing parameters to various
.B portmap
procedures, externally.
This routine is useful for users who wish to generate
these parameters without using the
.B pmap
interface.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
xdr_pmaplist(xdrs, rp)
\s-1XDR\s0 *xdrs;
struct pmaplist **rp;
.fi
.ft R
.IP
Used for describing a list of port mappings, externally.
This routine is useful for users who wish to generate
these parameters without using the
.B pmap
interface.
.br
.if t .ne 7
.LP
.ft B
.nf
.sp .5
xdr_rejected_reply(xdrs, rr)
\s-1XDR\s0 *xdrs;
struct rejected_reply *rr;
.fi
.ft R
.IP
Used for describing
.SM RPC
reply messages.
This routine is useful for users who wish to generate
.SM RPC\s0-style
messages without using the
.SM RPC
package.
.br
.if t .ne 8
.LP
.ft B
.nf
.sp .5
xdr_replymsg(xdrs, rmsg)
\s-1XDR\s0 *xdrs;
struct rpc_msg *rmsg;
.fi
.ft R
.IP
Used for describing
.SM RPC
reply messages.
This routine is useful for users who wish to generate
.SM RPC
style messages without using the
.SM RPC
package.
.br
.if t .ne 8
.LP
.ft B
.nf
.sp .5
void
xprt_register(xprt)
\s-1SVCXPRT\s0 *xprt;
.fi
.ft R
.IP
After
.SM RPC
service transport handles are created,
they should register themselves with the
.SM RPC
service package.
This routine modifies the global variable
.BR svc_fds(\|) .
Service implementors usually do not need this routine.
.br
.if t .ne 8
.LP
.ft B
.nf
.sp .5
void
xprt_unregister(xprt)
\s-1SVCXPRT\s0 *xprt;
.fi
.ft R
.IP
Before an
.SM RPC
service transport handle is destroyed,
it should unregister itself with the
.SM RPC
service package.
This routine modifies the global variable
.BR svc_fds(\|) .
Service implementors usually do not need this routine.
.SH SEE ALSO
.BR rpc_secure (3),
.BR xdr (3)
.br
The following manuals:
.RS
.ft I
Remote Procedure Calls: Protocol Specification
.br
Remote Procedure Call Programming Guide
.br
rpcgen Programming Guide
.br
.ft R
.RE
.IR "\s-1RPC\s0: Remote Procedure Call Protocol Specification" ,
.SM RFC1050, Sun Microsystems, Inc.,
.SM USC-ISI\s0.