Add python packaging for the bpf library

* Add tagging/git support
* Reorganize bpf py lib to be more pythonic
* Add pip installable builders
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Add simple single file example

Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Update license in source code to be Apache 2

Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Convert to using pyroute2 for tc

* Remove libbpf.c netlink
* Requires pyroute2 from source
 git clone https://github.com/svinota/pyroute2.git;
          cd pyroute2; sudo make install

Update: Remove references to mnl
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Rename files and a few functions

Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Add support for packet field write

* Rewrite LValue packet dereference to bpf_dins
* Add incr_csum as a macro
* Update names of a few functions
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Return 0 in lookup_or_init error path

Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Add packet read syntax to c parser

* C macro-based state machine
* Add lookup_or_init helper routine instead of array syntax
* Recognize references to protocol headers and translate into dext call
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Fix a python (version 2.7.3) error

Signed-off-by: Yonghong Song <yhs@plumgrid.com>

Fix for 2 tests

* name needed to be right ctype
* python runtime was complaining about dangling socket fd
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Fix for LLVM C++ api change

* IRBuilder::CreateCallN was deprecated, use the vector based mechanism
  for passing args instead
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Address comments and add tail_call example

* Cleanup some api names and definitions
* Add <table>.call() in C api, which maps to bpf_tail_call
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Address some of Issue #16

* Introduce Function object in bpf.py
 - prog load types (kprobe, socket, etc.) are independent
 - fd is a member of each function, to be used later (e.g. tail call table)
* Allow functions to be defined inline in the .py as a text argument
* Rename BPFProgram to BPFModule, which should make more sense
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Add clang support to bcc

* Frontend options: b and modified c languages
* Tests written for both languages
* Automatic kbuild integration
* Some cleanups and files moved
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

fix a typo

Signed-off-by: Yonghong Song <yhs@plumgrid.com>

Use clang as a lib to parse the helper file live

* Add clang as a library to the .so...this adds about 16M of stuff
* Compute the build flags for clang from the current kernel's header
  build tree. It generates a makefile on the fly and caches the minimal
  flags as an output.
* Followup to this would be to migrate bitops.c to be #include'd as well
  as the proto.d/kprobe.d stuff.
* For now, requires clang to be installed in /opt/local/llvm...see cmake
  files to override this.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Fix for Issue #8, pkt.rewrite_field

* This was unintentionally removed in the last cleanup, adding it back.
* Also adding support for $ip.dst = XXX style syntax
* This is an ugly commit, please bear with it until I figure out the
  structure of the language, especially w.r.t. proto:: type fields.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Reduce strength of clang requirement to 3.0

* All that is required is that clang binary IR is compatible
  with llvm 3.7.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

fix build with bison 2.5

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>