rpcgen(1N) rpcgen(1N)
NAME
rpcgen - an RPC protocol compiler
SYNOPSIS
rpcgen infile
rpcgen [-Dname[=value]] [-T] [-K secs] infile
rpcgen -c|-h|-l|-m|-t [-o outfile ] infile
rpcgen -s nettype [-o outfile] infile
rpcgen -n netid [-o outfile] infile
DESCRIPTION
rpcgen is a tool that generates C code to implement an RPC protocol.
The input to rpcgen is a language similar to C known as RPC Language
(Remote Procedure Call Language).
rpcgen is normally used as in the first synopsis where it takes an
input file and generates up to four output files. If the infile is
named proto.x, then rpcgen will generate a header file in proto.h,
XDR routines in protoxdr.c, server-side stubs in protosvc.c, and
client-side stubs in protoclnt.c. With the -T option, it will also
generate the RPC dispatch table in prototbl.i.
The server created can be started both by the port monitors (for
example, inetd or listen) or by itself. When it is started by a port
monitor, it creates servers only for the transport for which the file
descriptor 0 was passed. The name of the transport must be specified
by setting up the environmental variable PMTRANSPORT. When the
server generated by rpcgen is executed, it creates server handles for
all the transports specified in NETPATH environment variable, or if
it is unset, it creates server handles for all the visible transports
from /etc/netconfig file. Note: the transports are chosen at run
time and not at compile time. When the server is self-started, it
backgrounds itself by default. A special define symbol RPCSVCFG
can be used to run the server process in foreground.
The second synopsis provides special features which allow for the
creation of more sophisticated RPC servers. These features include
support for user provided #defines and RPC dispatch tables. The
entries in the RPC dispatch table contain:
⊕ pointers to the service routine corresponding to that
procedure,
⊕ a pointer to the input and output arguments
⊕ the size of these routines
A server can use the dispatch table to check authorization and then
to execute the service routine; a client library may use it to deal
with the details of storage management and XDR data conversion.
The other three synopses shown above are used when one does not want
to generate all the output files, but only a particular one. Some
examples of their usage is described in the EXAMPLE section below.
When rpcgen is executed with the -s option, it creates servers for
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that particular class of transports. When executed with the -n
option, it creates a server for the transport specified by netid. If
infile is not specified, rpcgen accepts the standard input.
The C preprocessor, cc -E [see cc(1)], is run on the input file
before it is actually interpreted by rpcgen. For each type of output
file, rpcgen defines a special preprocessor symbol for use by the
rpcgen programmer:
RPCHDR defined when compiling into header files
RPCXDR defined when compiling into XDR routines
RPCSVC defined when compiling into server-side stubs
RPCCLNT defined when compiling into client-side stubs
RPCTBL defined when compiling into RPC dispatch tables
Any line beginning with `%' is passed directly into the output file,
uninterpreted by rpcgen.
For every data type referred to in infile, rpcgen assumes that there
exists a routine with the string xdr prepended to the name of the
data type. If this routine does not exist in the RPC/XDR library, it
must be provided. Providing an undefined data type allows
customization of XDR routines.
The following options are available:
-c Compile into XDR routines.
-Dname[=value]
Define a symbol name. Equivalent to the #define directive in
the source. If no value is given, value is defined as 1. This
option may be specified more than once.
-h Compile into C data-definitions (a header file). -T option can
be used in conjunction to produce a header file which supports
RPC dispatch tables.
-K secs
By default, services created using rpcgen wait 120 seconds
after servicing a request before exiting. That interval can be
changed using the -K flag. To create a server that exits
immediately upon servicing a request, -K 0 can be used. To
create a server that never exits, the appropriate argument is
-K -1.
When monitoring for a server, some portmonitors, like
listen(1M), always spawn a new process in response to a service
request. If it is known that a server will be used with such a
monitor, the server should exit immediately on completion. For
such servers, rpcgen should be used with -K -1.
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-l Compile into client-side stubs.
-m Compile into server-side stubs, but do not generate a main
routine. This option is useful for doing callback-routines and
for users who need to write their own main routine to do
initialization.
-n netid
Compile into server-side stubs for the transport specified by
netid. There should be an entry for netid in the netconfig
database. This option may be specified more than once, so as
to compile a server that serves multiple transports.
-o outfile
Specify the name of the output file. If none is specified,
standard output is used (-c, -h, -l, -m, -n, -s and -t modes
only).
-s nettype
Compile into server-side stubs for all the transports belonging
to the class nettype. The supported classes are netpath,
visible, circuitn, circuitv, datagramn, datagramv, tcp, and
udp [see rpc(3N) for the meanings associated with these
classes]. This option may be specified more than once. Note:
the transports are chosen at run time and not at compile time.
-t Compile into RPC dispatch table.
-T Generate the code to support RPC dispatch tables.
The options -c, -h, -l, -m, -s and -t are used exclusively to
generate a particular type of file, while the options -D and -T are
global and can be used with the other options.
NOTES
The RPC Language does not support nesting of structures. As a work-
around, structures can be declared at the top-level, and their name
used inside other structures in order to achieve the same effect.
Name clashes can occur when using program definitions, since the
apparent scoping does not really apply. Most of these can be avoided
by giving unique names for programs, versions, procedures and types.
The server code generated with -n option refers to the transport
indicated by netid and hence is very site specific.
EXAMPLE
The following example:
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$ rpcgen -T prot.x
generates all the five files: prot.h, protclnt.c, protsvc.c,
protxdr.c and prottbl.i.
The following example sends the C data-definitions (header file) to
the standard output.
$ rpcgen -h prot.x
To send the test version of the -DTEST, server side stubs for all the
transport belonging to the class datagramn to standard output, use:
$ rpcgen -s datagramn -DTEST prot.x
To create the server side stubs for the transport indicated by netid
tcp, use:
$ rpcgen -n tcp -o protsvc.c prot.x
SEE ALSO
cc(1).
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