rpcgen(1) rpcgen(1)
NAME
rpcgen - an RPC protocol compiler
SYNOPSIS
rpcgen infile
rpcgen [-C cppcmd] [-Dname[=value]] [-T] [-P] [-I | -K secs] infile
rpcgen -c|-h|-l|-m|-t [-P] [-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.
rpcgen will produce file to be used with libc [see intro.3n(1)]. To
produce file to be used with libnsl see rpcgentli(1). 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 environment 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 not set, 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 symbol, RPCSVCFG, can be defined at compilation time to make
the server process run 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 that particular class
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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 cppcmd
Run the preprocessor command, cppcmd, instead of the default, cpp.
-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). The -T option can
be used in conjunction to produce a header file which supports RPC
dispatch tables.
-I Compile support for inetd(1M) in the server side stubs. Such
servers can be self-started or can be started by inetd. 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, or the user may simply compile without the -I option.
If there are no pending client requests, the inetd servers exit
after 120 seconds (default). The default can be changed with the -K
option. All the error messages for inetd servers are always logged
with syslog(3).
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Note: this option is supported for backward compatibility only. By
default, rpcgen generates servers that can be invoked through
portmonitors.
-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.
-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).
-P Generate prototyped XDR and stub function declarations and
definitions suitable for ANSI C and C++. The prototypes for the
client- and server-side stubs are different; their declarations in
the generated header file are conditionally-compiled with the values
_RPCGEN_CLNT or _RPCGEN_SVC. If you write your own client or server
code, you must define the appropriate value in your source files
before including the generated header file. Using the example above,
the file for client code should use:
#define _RPCGEN_CLNT
#include "proto.h"
and the file for server code should use:
#define _RPCGEN_SVC
#include "proto.h"
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-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, -P, 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:
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 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
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SEE ALSO
cc(1), rpgentli(1)
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