Add option for custom log string to bpf_prog_load

bpf_prog_load was unconditionally printing the error from the kernel to
stderr. If libbpf is used in a library, that library may want to collect
the error to a custom location (a logfile). So, provide an option to
store the string elsewhere than stderr.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

import "input" from "builtins" for python v2/v3 compatibility

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

full mesh vxlan example without multicast

Run 'sudo python ./main.py mesh'
Signed-off-by: Wei-Chun Chao <weichunc@plumgrid.com>

Dist bridge

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

* Update compat.h
* Move bpf_clone_redirect to signed int, matching the implementation.
  This allows error codes to be compared to < 0.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Add index-based function references to c api

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

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

* Add the index based API so that an external api (bcc-fuse) can iterate
  through the maps and functions that were compiled in this program.
* Add a more unique section prefix to disambiguate exportable functions.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Include bcc headers in /usr/include

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

* Add wrapper bcc.h to include dependencies
* Add text bpf_module_create_* to list of exports
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

simply vlan_learning example with newer vlan_push/pop helpers

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

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

Cache function handles in BPF class

* This means repeated calls to get_func() are now allowed
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

use running linux version number for feature availability checking

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

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

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

Change to simulator arguments for readability

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

* Let one argument be optional
* Disable ipv6 for whole namespace once
* Python 2/3 compatibility fix
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Bugfix for simulation.py

* Ignore exceptions and continue cleanup of dead children
* Set loopback interface up
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Yhs dev

  o This way, process kill happens correctly.
Signed-off-by: Yonghong Song <yhs@plumgrid.com>

   o sometimes, NSPipe kill may not really kill the process
   o with the explicit kill, remove the cleanup for outer veth's
     associated with namespace
Signed-off-by: Yonghong Song <yhs@plumgrid.com>

    o make some long lines in python codes shorter
    o use python style unused variable name "_"
Signed-off-by: Yonghong Song <yhs@plumgrid.com>

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

   o disable ipv6 for newly-created net devices to avoid unaccountable pkt counting
   o explicitly enable ip_forward in router namespace
   o proper cleanup in case of validation failure
   o in test_brb, use different tc_index to differentiate the packet source (pem or router_ns)
   o change bpf program return value to 1 so that the packet will be dropped instead of being
     passed up to the stack
Signed-off-by: Yonghong Song <yhs@plumgrid.com>

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>