RPCGEN(1) OpenBSD Reference Manual RPCGEN(1)NAMErpcgen - RPC protocol compiler
SYNOPSISrpcgen [-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]
DESCRIPTIONrpcgen 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.
EXAMPLES
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
NOTES
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.
SEE ALSOcpp(1)OpenBSD 4.9 September 19, 2010 OpenBSD 4.9
