RPCGEN(1) BSD General Commands Manual RPCGEN(1)
NAME
rpcgen -- Remote Procedure Call (RPC) protocol compiler
SYNOPSIS
rpcgen infile
rpcgen [-D [name=value]] [-A] [-M] [-T] [-K secs] infile
rpcgen [-L] -c | -h | -l | -m | -t | -Sc | -Ss | [-o outfile] [infile]
rpcgen -c | nettype [-o outfile] [infile]
rpcgen -s | 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 proto_xdr.c, server-side serverside
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 illus-trate illustrate
trate 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 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 environ-mental environmental
mental variable PM_TRANSPORT. When the server generated by rpcgen is executed, it creates server han-dles handles
dles 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 RPC_SVC_FG 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 dis-patch dispatch
patch 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 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 program-mer: programmer:
mer:
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.
OPTIONS
-a Generate all the files including sample code for client and server side.
-b This generates code for the SunOS 4.1 style of RPC. This is the default.
-C Generate code in ANSI C. This option also generates code that could be compiled with the C++
compiler.
-c Compile into XDR routines.
-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 imme-diately immediately
diately 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 AT&T System V.4 UNIX utility
listen(1), 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 Server errors will be sent to syslog instead of stderr.
-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 ini-tialization. initialization.
tialization.
-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.
-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 modes only)
-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.
-s nettype
Compile into server-side stubs for all the transports belonging to the class nettype. The sup-ported supported
ported 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.
-T Generate the code to support RPC dispatch tables.
-t Compile into RPC dispatch table.
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 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
SEE ALSO
cpp(1)
June 11, 1995
|