tools: Add xdrgen

Add a Python-based tool for translating XDR specifications into XDR
encoder and decoder functions written in the Linux kernel's C coding
style. The generator attempts to match the usual C coding style of
the Linux kernel's SunRPC consumers.

This approach is similar to the netlink code generator in
tools/net/ynl .

The maintainability benefits of machine-generated XDR code include:

- Stronger type checking
- Reduces the number of bugs introduced by human error
- Makes the XDR code easier to audit and analyze
- Enables rapid prototyping of new RPC-based protocols
- Hardens the layering between protocol logic and marshaling
- Makes it easier to add observability on demand
- Unit tests might be built for both the tool and (automatically)
  for the generated code

In addition, converting the XDR layer to use memory-safe languages
such as Rust will be easier if much of the code can be converted
automatically.

Tested-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/tools/net/sunrpc/xdrgen/templates/C/pointer/definition/basic.j2 b/tools/net/sunrpc/xdrgen/templates/C/pointer/definition/basic.j2
new file mode 100644
index 000000000000..b3430895f311
--- /dev/null
+++ b/tools/net/sunrpc/xdrgen/templates/C/pointer/definition/basic.j2
@@ -0,0 +1,5 @@
+{# SPDX-License-Identifier: GPL-2.0 #}
+{% if annotate %}
+	/* (basic) */
+{% endif %}
+	{{ classifier }}{{ type }} {{ name }};