Update README.md examples and INSTALL.md

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

Update README with install info, few cleanups

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

* Add some examples to package
* Fix bpf_trace_printk bug not supporting 0 format args
* Make src_file arg loading a little bit more intelligent in BPF()
* Update README with Hello, World step-by-step
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Add multiple build support styles

* Add RPM and DEB packaging targets (using CPack from CMake) to build
  binary packages for Fedora and Ubuntu targets.
* Add Docker build scripts for each of the above that run the build in
  the right environment (assuming docker is available).
 - In Ubuntu, build against the LLVM 3.7 nightly snapshots
 - In Fedora, build against LLVM 3.7 from git (takes longer)
* Depending on packages installed on the build machine, it may be
  possible to cross-package for other targets without invoking Docker.
* Re-introduce src/cc/compat directory to keep the build stable for the
  time being. Similarly, it was necessary to #define some ugly constants
  that should eventually show up in libc.
* Add a few simple version checks to allow a partially working (really
  tracing only) libbcc in 4.1 kernels.

TODO (followup commit): Re-work the READMEs
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

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

* Install into lib64 instead of lib
* Pull 4.2 kernel from rawhide instead of building it
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Drop PROTO macro syntax and introduce alternative

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

* Feedback given by some external users was that the PROTO syntax was
  opaque and unintuitive. As such, drop that macro and introduce an
  alternative syntax.
* Convert all to use 'cursor_advance' macro API
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Automate bpf_probe_read

* Rewrite accesses to args beyond the first to use bpf_probe_read
 - Support struct access
 - Support POD type accesses
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Clean some brittle parts of clang rewriter

* Rewrites of text inside of a macro (even if just the arguments) is not
  support by clang. Convert macro definitions to pure rewrites instead.
* For packet field access, no longer require 'skb' named
  argument...instead, learn it from the function parameter list.
* Add a complex test case...supposedly this should have failed issue
  #10, but the C version does not exhibit the same failure as the B
  version.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Make tunnel example more user friendly

* Move files to separate directory
* Add README
* Run http server automatically from main.py
* Add setup.sh script to automate dependencies
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

use new get_table interface to avoid specify key/leaf type in py code

Add vxlan tunnel monitoring example

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

use "raw_input" instead "input" to avoid python 2.7 exception

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

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

* Example simulates many vxlan hosts ("hypervisors") with multiple clients per
  host. Some clients will be sending traffic to another client on a different
  host.
* Add vxlan header to proto.h
* Remove unused import line in vlan_learning
* NOTE: to display this demo, it is required to checkout the chord graph demo
  from https://github.com/drzaeus77/chord-transitions.git.
  Follow the instructions in that repo to get a simple http server up and
  running.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Rework vlan example to be 1:1, no mac learning

example that shows usages of maps, probe_read, get_current_pid helpers

$ ./task_switch.py

task_switch[ 2379->    0]=4
task_switch[ 3914->    0]=2
task_switch[ 3133->    0]=5
task_switch[10903->    0]=100  <-- 100 times python process switched into idle
task_switch[  116->    0]=1
task_switch[    0->   14]=1
task_switch[10803->    0]=1
task_switch[22292->    0]=1
task_switch[    0->22292]=1
task_switch[    0->10803]=1
task_switch[   30->    0]=1
task_switch[    0->10903]=100  <-- 100 times back into python
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>

* Use ifindex instead of src_mac to program egress table
* Remove the static arp programming
* Get the example to work in python2
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Move shared example code into simulation.py

* Create a class for the examples to share, helps with IPDB cleanup and
  namespace creation.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Remove update() call from vlan example

* Breakage from previous commit
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Make python table accesses more pythonic

* Add [] support in BPF.Table class
* Remove uses of lookup/update
* Add del support
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

add get_current_pid/tgid/uid/gid/comm helpers

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

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

Automatically compute sizeof in bpf_trace_printk

* Addresses issue #61
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>