rpcgen - RPC protocol compiler
rpcgen [-aALTNbC] [-D [name[=value]]] [-K secs] [-i lines]
infile
rpcgen -c | -h | -l | -m | -t | -Sc | -Ss | [-o outfile]
[infile]
rpcgen -c | nettype [-o outfile] [infile]
rpcgen is a tool that generates C code to implement an RPC
protocol. The
input 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 proto_xdr.c, server-side stubs in
proto_svc.c,
and client-side stubs in proto_clnt.c. With the -T option,
it will also
generate the RPC dispatch table in proto_tbl.i. With the
-Sc option, it
will also generate sample code which would illustrate how to
use the remote
procedures on the client side. This code would be created in
proto_client.c. With the -Ss option, it will also generate
a sample
server code which would illustrate how to write the remote
procedures.
This code would be created in proto_server.c.
The server created can be started both by the port monitors
(for example,
inetd(8)) 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 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 RPC_SVC_FG can be used to run the
server process in
the 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 EXAMPLES section below.
When rpcgen
is executed with the -s option, it creates servers for 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, cpp(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:
RPC_HDR Defined when compiling into header files.
RPC_XDR Defined when compiling into XDR routines.
RPC_SVC Defined when compiling into server-side stubs.
RPC_CLNT Defined when compiling into client-side stubs.
RPC_TBL 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 options are as follows:
-a Generate all the files including sample code for
client and server
side.
-b This generates code for the SunOS4.1 style of RPC.
This is the
default.
-c Compile into XDR routines.
-C Generate code in ANSI C. This option also generates
code that
could be compiled with the C++ compiler.
-D name[=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).
The -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 port monitors, like
the SVR4 listen
utility, 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''.
-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.
-N Use the newstyle of rpcgen. This allows procedures
to have multiple
arguments. It also uses the style of parameter passing
that closely resembles C. So, when passing an argument to a remote
procedure you do not have to pass a pointer to
the argument
but the argument itself. This behaviour is different from the
oldstyle of rpcgen generated code. The newstyle is
not the default
case because of backward compatibility.
-o outfile
Specify the name of the output file. If none is
specified, standard
output is used (-c -h -l -m -n -s modes only).
-s nettype
Compile into server-side stubs for all the transports belonging
to the class nettype. The supported classes are
netpath,
visible, circuit_n, circuit_v, datagram_n,
datagram_v, tcp, and
udp [see rpc(3) for the meanings associated with
these classes.
Note: BSD currently supports only the tcp and udp
classes]. This
option may be specified more than once. Note: the
transports are
chosen at run time and not at compile time.
-Sc Generate sample code to show the use of remote procedure and how
to bind to the server before calling the client side
stubs generated
by rpcgen.
-Ss Generate skeleton code for the remote procedures on
the server
side. You would need to fill in the actual code for
the remote
procedures.
-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.
The command
$ rpcgen -T prot.x
generates the five files: prot.h, prot_clnt.c, prot_svc.c,
prot_xdr.c and
prot_tbl.i.
The following example sends the C data-definitions (header
file) to 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 datagram_n to standard output, use:
$ rpcgen -s datagram_n -DTEST prot.x
To create the server side stubs for the transport indicated
by netid tcp,
use:
$ rpcgen -n tcp -o prot_svc.c prot.x
The RPC Language does not support nesting of structures. As
a
workaround, 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.
cpp(1)
OpenBSD 3.6 June 11, 1995
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