[PATCH/RFC 0/6] JNI bindings for libopenconnect

[Kevin Cernekee]

This patch series adds native Java API wrappers for current
libopenconnect functions.  The eventual goal is to be able to use
libopenconnect in an Android VpnService based client app, so it's
still a work in progress and there is much more left to be done.  I'm
posting this now to gather feedback and to compare notes with anyone
else who has been working on similar projects.

The "LibTest" command-line program is able to successfully complete
authentication and obtain VPN cookies through JNI.

My initial attempt was based on SWIG, but I quickly discovered that
SWIG was only helpful for the "easy" APIs like
openconnect_get_version().  In general the automated conversion tools
don't seem to cope well with variations on string allocation
(caller-allocated buffers, callee-allocated but caller-frees, etc.)
and they have no idea what to do with the four callback functions or
the auth form structs.  I also ran into problems with function name
translation (SWIG would either let me prune the openconnect_ prefix,
or re-capitalize the names into camelcase, but not both).  And I
couldn't seem to convince it to treat vpninfo as an instance variable
so that the callers wouldn't have to explicitly pass it into every
function.

It wouldn't be too surprising to find memory leaks in jni.c,
especially in the error paths, as I'm not 100% positive on the rules
for freeing strings and objects provided by the JVM.  Also, this code
hasn't been run under Android's CheckJNI yet.


The following changes since commit 6fc3a31095d02d03334fde283696f981a452638e:

  Tag version 5.01 (2013-06-01 21:21:19 +0100)

are available in the git repository at:

  git://github.com/cernekee/openconnect master

for you to fetch changes up to fb93f05172b220ff8070d022bb003c7137d748b3:

  JNI: Add demo program to illustrate library usage (2013-08-04 18:19:07 -0700)

----------------------------------------------------------------
Kevin Cernekee (6):
      Remove declaration for nonexistent openconnect_get_vpn_name()
      gitignore: Use absolute path for openconnect
      JNI: Initial commit of C and Java sources
      acinclude: Add AX_JNI_INCLUDE_DIR macro
      buildsys: Add JNI to libopenconnect build
      JNI: Add demo program to illustrate library usage

 .gitignore                                    |    2 +-
 Makefile.am                                   |    5 +
 acinclude.m4                                  |  119 ++++
 configure.ac                                  |   25 +
 jni.c                                         |  871 +++++++++++++++++++++++++
 libopenconnect.map.in                         |    5 +
 openconnect.h                                 |    1 -
 org/example/LibTest.java                      |  145 ++++
 org/infradead/openconnect/LibOpenConnect.java |  201 ++++++
 9 files changed, 1372 insertions(+), 2 deletions(-)
 create mode 100644 jni.c
 create mode 100644 org/example/LibTest.java
 create mode 100644 org/infradead/openconnect/LibOpenConnect.java

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1.7.9.5