[Openvpn-devel,v2] sample-plugins: Partially autotoolize the sample-plugins build

Message ID 20200914122721.14173-1-davids@openvpn.net
State Changes Requested
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Series
  • [Openvpn-devel,v2] sample-plugins: Partially autotoolize the sample-plugins build
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Commit Message

David Sommerseth Sept. 14, 2020, 12:27 p.m.
The sample-plugins have their own set of build/winbuild scripts in each
of these plugin directories.  This does not give a good way to reuse
various macros the autoconf/automake/configure process enables; which
can contain important macros to make some code build without errors or
warnings.

Normally we would embrace the full autoconf/automake approach. But this
is sample code which we only want to build per request and the built
code should not be installed anywhere via 'make install'.  But since we
do use libtool other plug-ins being installed and automake gets kind of
cranky when it comes to define certain build targets not following the
expected use cases, we try to only embrace just enough of automake to
get our main goals achieved.

This changeset kicks out the build scripts and replaces them with a
single Makefile.plugins file, which defines the plugins we want to build
by default when running 'make from the sample-plugins directory.
Neither of these plugins are otherwise built by default.  No sample-plugins
are being installed.  But we have enough strings attached to automake
to grab the CFLAGS and LDFLAGS used by the rest of the code.  This also
makes it easy to use #include "config.h" in sample code, to also get
various macros defined by the ./configure run.

This patch does not touch the winbuild scripts, as it seems building
these sample-plugins on Windows requires a bit different compile and
linking steps than *nix systems in general.

Signed-off-by: David Sommerseth <davids@openvpn.net>

---
v2 - Process README files with correct instructions and details
---
 configure.ac                                  |  1 +
 sample/sample-plugins/Makefile.am             | 28 ++++++++++++++
 sample/sample-plugins/Makefile.plugins        | 31 ++++++++++++++++
 sample/sample-plugins/README                  | 37 +++++++++++++++++++
 sample/sample-plugins/defer/README            | 16 --------
 sample/sample-plugins/defer/build             | 15 --------
 .../keying-material-exporter-demo/build       | 15 --------
 sample/sample-plugins/log/build               | 15 --------
 sample/sample-plugins/simple/README           | 16 --------
 sample/sample-plugins/simple/build            | 15 --------
 10 files changed, 97 insertions(+), 92 deletions(-)
 create mode 100644 sample/sample-plugins/Makefile.am
 create mode 100644 sample/sample-plugins/Makefile.plugins
 create mode 100644 sample/sample-plugins/README
 delete mode 100644 sample/sample-plugins/defer/README
 delete mode 100755 sample/sample-plugins/defer/build
 delete mode 100755 sample/sample-plugins/keying-material-exporter-demo/build
 delete mode 100755 sample/sample-plugins/log/build
 delete mode 100644 sample/sample-plugins/simple/README
 delete mode 100755 sample/sample-plugins/simple/build

Comments

Gert Doering Sept. 15, 2020, 10:22 a.m. | #1
Hi,

On Mon, Sep 14, 2020 at 02:27:21PM +0200, David Sommerseth wrote:
> The sample-plugins have their own set of build/winbuild scripts in each
> of these plugin directories.  This does not give a good way to reuse
> various macros the autoconf/automake/configure process enables; which
> can contain important macros to make some code build without errors or
> warnings.

This looks like a step in the right direction, but is not fully working
yet - I tried both an "in-tree" and "out of tree" build, and it fails
compilation with

sample-plugins$ gmake
test -d `dirname defer/simple.o` || ../../../openvpn/./install-sh -c -d `dirname defer/simple.o`; \
cc -c -o defer/simple.o -Wall -Wno-unused-parameter -Wno-unused-function -g -O2 -std=c99 -I../../../openvpn -fPIC ../../../openvpn/sample/sample-plugins/defer/simple.c
../../../openvpn/sample/sample-plugins/defer/simple.c:58:10: fatal error: 'openvpn-plugin.h' file
      not found
#include "openvpn-plugin.h"
         ^~~~~~~~~~~~~~~~~~
1 error generated.


openvpn-plugin.h is installed if you install openvpn first, but if
you only build in tree, it seems to need an extra 

  -I$(top_srcdir)/include

to find openvpn-plugin.h

It also needs gmake - running "make" will do "nothing at all", which
I found surprising, but did not investigate more closely.  This is likely
due to implicit rules that need to be written differently for BSD make.

I do not think this is a serious issue - just document it in the README,
and it's still better than 4 individual "build" files, half of it who
were missing the needed "-I" as well :-)

gert
David Sommerseth Sept. 15, 2020, 8:52 p.m. | #2
On 15/09/2020 12:22, Gert Doering wrote:
> Hi,
> 
> On Mon, Sep 14, 2020 at 02:27:21PM +0200, David Sommerseth wrote:
>> The sample-plugins have their own set of build/winbuild scripts in each
>> of these plugin directories.  This does not give a good way to reuse
>> various macros the autoconf/automake/configure process enables; which
>> can contain important macros to make some code build without errors or
>> warnings.
> 
> This looks like a step in the right direction, but is not fully working
> yet - I tried both an "in-tree" and "out of tree" build, and it fails
> compilation with
> 
> sample-plugins$ gmake
> test -d `dirname defer/simple.o` || ../../../openvpn/./install-sh -c -d `dirname defer/simple.o`; \
> cc -c -o defer/simple.o -Wall -Wno-unused-parameter -Wno-unused-function -g -O2 -std=c99 -I../../../openvpn -fPIC ../../../openvpn/sample/sample-plugins/defer/simple.c
> ../../../openvpn/sample/sample-plugins/defer/simple.c:58:10: fatal error: 'openvpn-plugin.h' file
>       not found
> #include "openvpn-plugin.h"
>          ^~~~~~~~~~~~~~~~~~
> 1 error generated.
> 
> 
> openvpn-plugin.h is installed if you install openvpn first, but if
> you only build in tree, it seems to need an extra 
> 
>   -I$(top_srcdir)/include
> 
> to find openvpn-plugin.h

Hmmm ... I would have expected that to be picked up automatically, but clearly
didn't watch the compile arguments carefully enough.

> It also needs gmake - running "make" will do "nothing at all", which
> I found surprising, but did not investigate more closely.  This is likely
> due to implicit rules that need to be written differently for BSD make.

Yikes ... I see potentially two issues here.  BSD Make seems to lack support
for $(foreach ...) and it does not grok '%.so : %.o' (which is Make "macro
magic" to simplify rule writing).  To avoid this and make it BSD Make
compatible, we would probably need to go full-fledged automake - pulling in
libtools (and the awkward .libs directories, .la/.lo files, etc, etc).

So if we're fine with reducing this to GNU Make only, the change is trivial.

> I do not think this is a serious issue - just document it in the README,
> and it's still better than 4 individual "build" files, half of it who
> were missing the needed "-I" as well :-)

New updated patch coming very soon.

Patch

diff --git a/configure.ac b/configure.ac
index f8279924..ebb32204 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1433,6 +1433,7 @@  AC_CONFIG_FILES([
 	doc/doxygen/Makefile
 	doc/doxygen/openvpn.doxyfile
 	include/Makefile
+	sample/sample-plugins/Makefile
 	src/Makefile
 	src/compat/Makefile
 	src/openvpn/Makefile
diff --git a/sample/sample-plugins/Makefile.am b/sample/sample-plugins/Makefile.am
new file mode 100644
index 00000000..d02abe48
--- /dev/null
+++ b/sample/sample-plugins/Makefile.am
@@ -0,0 +1,28 @@ 
+#
+#  OpenVPN -- An application to securely tunnel IP networks
+#             over a single UDP port, with support for SSL/TLS-based
+#             session authentication and key exchange,
+#             packet encryption, packet authentication, and
+#             packet compression.
+#
+#  Copyright (C) 2002-2020 OpenVPN Inc <sales@openvpn.net>
+#
+
+MAINTAINERCLEANFILES = \
+	$(srcdir)/Makefile.in
+
+# We don't want automake to pull in libtool for building these
+# sample-plugins.  Even though this breaks the conceptual ideas
+# around autoconf/automake/libtools ... these sample plug-ins
+# are just sample code, not to be installed or distributed outside
+# of the source tarball.  Not even built by default, by design.
+#
+# We only add this as a simple and convenient way to build all
+# these plug-ins with the same build parameters as the rest
+# of the OpenVPN code.
+#
+# All the plugins which will be built are processed in this
+# separate Makefile, which disconnects everything just enough
+# to achieve our goal.
+include Makefile.plugins
+
diff --git a/sample/sample-plugins/Makefile.plugins b/sample/sample-plugins/Makefile.plugins
new file mode 100644
index 00000000..76768dbe
--- /dev/null
+++ b/sample/sample-plugins/Makefile.plugins
@@ -0,0 +1,31 @@ 
+#  SPDX-License-Identifier: GPL-2.0-only
+#
+#  Copyright (C) 2020 OpenVPN Inc <sales@openvpn.net>
+#
+
+#
+# Plug-ins to build - listed entries should not carry any extensions
+#
+PLUGINS = \
+	defer/simple \
+	keying-material-exporter-demo/keyingmaterialexporter \
+	log/log log/log_v3 \
+	simple/base64 \
+	simple/simple
+
+# All the plugins to build - rewritten with .so extension
+all : $(foreach var, $(PLUGINS), $(var).so)
+
+# Compile step
+.c.o :
+	test -d `dirname $@` || $(MKDIR_P) `dirname $@`; \
+	$(CC) -c -o $@ $(CFLAGS) -I$(top_srcdir) -fPIC $<
+
+# Link step
+%.so : %.o
+	$(CC) $(LDFLAGS) -shared -fPIC -o $@ $<
+
+# Clean up all build object and shared object files
+clean :
+	rm -f $(foreach var, $(PLUGINS), $(var).o) \
+	$(foreach var, $(PLUGINS), $(var).so)
diff --git a/sample/sample-plugins/README b/sample/sample-plugins/README
new file mode 100644
index 00000000..167d8d32
--- /dev/null
+++ b/sample/sample-plugins/README
@@ -0,0 +1,37 @@ 
+OpenVPN plug-in examples.
+
+Examples provided:
+
+* authentication and logging
+simple/simple.c -- using the --auth-user-pass-verify callback, verify
+                   that the username/password is "foo"/"bar".
+defer/simple.c  -- using the --auth-user-pass-verify callback,
+                   test deferred authentication.
+log/log.c       -- Extended variant of simple/simple.c which adds more
+                   logging of what is happening inside the plug-in
+log/log_v3.c    -- A variant of log/log.c, which makes use of the
+                   OpenVPN plug-in v3 API.  This will also log even more
+                   information related to certificates in use.
+
+* cryptography related
+simple/base64.c -- Example using the OpenVPN exported base64 encode/decode
+                   functions
+keying-material-exporter-demo/keyingmaterialexporter.c
+                -- Example based on TLS Keying Material Exporters over HTTP [RFC-5705]
+                   (openvpn/doc/keying-material-exporter.txt).  For more details, see
+                   keying-material-exporter-demo/README
+
+
+To build on *BSD/Linux platforms:
+
+   make                   (builds a default set of plug-ins)
+   make simple/simple.so
+
+To build on Windows platform (MinGW):
+
+   cd simple; ./winbuild simple.so
+
+To use in OpenVPN, add to config file:
+
+  plugin simple.so (Linux/BSD/etc.)
+  plugin simple.dll
diff --git a/sample/sample-plugins/defer/README b/sample/sample-plugins/defer/README
deleted file mode 100644
index d8990f8b..00000000
--- a/sample/sample-plugins/defer/README
+++ /dev/null
@@ -1,16 +0,0 @@ 
-OpenVPN plugin examples.
-
-Examples provided:
-
-simple.c -- using the --auth-user-pass-verify callback,
-            test deferred authentication.
-
-To build:
-
-  ./build simple (Linux/BSD/etc.)
-  ./winbuild simple (MinGW on Windows)
-
-To use in OpenVPN, add to config file:
-
-  plugin simple.so (Linux/BSD/etc.)
-  plugin simple.dll (MinGW on Windows)
diff --git a/sample/sample-plugins/defer/build b/sample/sample-plugins/defer/build
deleted file mode 100755
index ba41a39f..00000000
--- a/sample/sample-plugins/defer/build
+++ /dev/null
@@ -1,15 +0,0 @@ 
-#!/bin/sh
-
-#
-# Build an OpenVPN plugin module on *nix.  The argument should
-# be the base name of the C source file (without the .c).
-#
-
-# This directory is where we will look for openvpn-plugin.h
-CPPFLAGS="${CPPFLAGS:--I../../../include}"
-
-CC="${CC:-gcc}"
-CFLAGS="${CFLAGS:--O2 -Wall -g}"
-
-$CC $CPPFLAGS $CFLAGS -fPIC -c $1.c && \
-$CC $CFLAGS -fPIC -shared ${LDFLAGS} -Wl,-soname,$1.so -o $1.so $1.o -lc
diff --git a/sample/sample-plugins/keying-material-exporter-demo/build b/sample/sample-plugins/keying-material-exporter-demo/build
deleted file mode 100755
index bbb05f7c..00000000
--- a/sample/sample-plugins/keying-material-exporter-demo/build
+++ /dev/null
@@ -1,15 +0,0 @@ 
-#!/bin/sh
-
-#
-# Build an OpenVPN plugin module on *nix.  The argument should
-# be the base name of the C source file (without the .c).
-#
-
-# This directory is where we will look for openvpn-plugin.h
-CPPFLAGS="${CPPFLAGS:--I../../..}"
-
-CC="${CC:-gcc}"
-CFLAGS="${CFLAGS:--O2 -Wall -g}"
-
-$CC $CPPFLAGS $CFLAGS -fPIC -c $1.c && \
-$CC $CFLAGS -fPIC -shared $LDFLAGS -Wl,-soname,$1.so -o $1.so $1.o -lc
diff --git a/sample/sample-plugins/log/build b/sample/sample-plugins/log/build
deleted file mode 100755
index c07ec408..00000000
--- a/sample/sample-plugins/log/build
+++ /dev/null
@@ -1,15 +0,0 @@ 
-#!/bin/sh
-
-#
-# Build an OpenVPN plugin module on *nix.  The argument should
-# be the base name of the C source file (without the .c).
-#
-
-# This directory is where we will look for openvpn-plugin.h
-CPPFLAGS="${CPPFLAGS:--I../../../include}"
-
-CC="${CC:-gcc}"
-CFLAGS="${CFLAGS:--O2 -Wall -g}"
-
-$CC $CPPFLAGS $CFLAGS -fPIC -c $1.c && \
-$CC $CFLAGS -fPIC -shared $LDFLAGS -Wl,-soname,$1.so -o $1.so $1.o -lc
diff --git a/sample/sample-plugins/simple/README b/sample/sample-plugins/simple/README
deleted file mode 100644
index 4400cd30..00000000
--- a/sample/sample-plugins/simple/README
+++ /dev/null
@@ -1,16 +0,0 @@ 
-OpenVPN plugin examples.
-
-Examples provided:
-
-simple.c -- using the --auth-user-pass-verify callback, verify
-            that the username/password is "foo"/"bar".
-
-To build:
-
-  ./build simple (Linux/BSD/etc.)
-  ./winbuild simple (MinGW on Windows)
-
-To use in OpenVPN, add to config file:
-
-  plugin simple.so (Linux/BSD/etc.)
-  plugin simple.dll (MinGW on Windows)
diff --git a/sample/sample-plugins/simple/build b/sample/sample-plugins/simple/build
deleted file mode 100755
index bbb05f7c..00000000
--- a/sample/sample-plugins/simple/build
+++ /dev/null
@@ -1,15 +0,0 @@ 
-#!/bin/sh
-
-#
-# Build an OpenVPN plugin module on *nix.  The argument should
-# be the base name of the C source file (without the .c).
-#
-
-# This directory is where we will look for openvpn-plugin.h
-CPPFLAGS="${CPPFLAGS:--I../../..}"
-
-CC="${CC:-gcc}"
-CFLAGS="${CFLAGS:--O2 -Wall -g}"
-
-$CC $CPPFLAGS $CFLAGS -fPIC -c $1.c && \
-$CC $CFLAGS -fPIC -shared $LDFLAGS -Wl,-soname,$1.so -o $1.so $1.o -lc