samples/bpf: use preferred getters/setters instead of deprecated ones

Use preferred setter and getter APIs instead of deprecated ones.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-7-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

samples: bpf: Fix 'unknown warning group' build warning on Clang

Clang doesn't have 'stringop-truncation' group like GCC does, and
complains about it when building samples which use xdp_sample_user
infra:

samples/bpf/xdp_sample_user.h:48:32: warning: unknown warning group '-Wstringop-truncation', ignored [-Wunknown-warning-option]
#pragma GCC diagnostic ignored "-Wstringop-truncation"
^
[ repeat ]

Those are harmless, but avoidable when guarding it with ifdef.
I could guard push/pop as well, but this would require one more
ifdef cruft around a single line which I don't think is reasonable.

Fixes: 156f886cf697 ("samples: bpf: Add basic infrastructure for XDP samples")
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20211203195004.5803-3-alexandr.lobakin@intel.com

samples: bpf: Convert xdp_redirect_map_multi to XDP samples helper

Use the libbpf skeleton facility and other utilities provided by XDP
samples helper. Also adapt to change of type of mac address map, so that
no resizing is required.

Add a new flag for sample mask that skips priting the
from_device->to_device heading for each line, as xdp_redirect_map_multi
may have two devices but the flow of data may be bidirectional, so the
output would be confusing.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-23-memxor@gmail.com

samples: bpf: Add devmap_xmit tracepoint statistics support

This adds support for retrieval and printing for devmap_xmit total and
mutli mode tracepoint. For multi mode, we keep a hash map entry for each
redirection stream, such that we can dynamically add and remove entries
on output.

The from_match and to_match will be set by individual samples when
setting up the XDP program on these devices.

The multi mode tracepoint is also handy for xdp_redirect_map_multi,
where up to 32 devices can be specified.

Also add samples_init_pre_load macro to finally set up the resized maps
and mmap them in place for low overhead stats retrieval.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-12-memxor@gmail.com

samples: bpf: Add cpumap tracepoint statistics support

This consolidates retrieval and printing into the XDP sample helper. For
the kthread stats, it expands xdp_stats separately with its own per-CPU
stats. For cpumap enqueue, we display FROM->TO stats also with its
per-CPU stats.

The help out explains in detail the various aspects of the output.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-10-memxor@gmail.com

samples: bpf: Add xdp_exception tracepoint statistics support

This implements the retrieval and printing, as well the help output.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-8-memxor@gmail.com

samples: bpf: Add redirect tracepoint statistics support

This implements per-errno reporting (for the ones we explicitly
recognize), adds some help output, and implements the stats retrieval
and printing functions.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-6-memxor@gmail.com

samples: bpf: Add basic infrastructure for XDP samples

This file implements some common helpers to consolidate differences in
features and functionality between the various XDP samples and give them
a consistent look, feel, and reporting capabilities.

This commit only adds support for receive statistics, which does not
rely on any tracepoint, but on the XDP program installed on the device
by each XDP redirect sample.

Some of the key features are:
* A concise output format accompanied by helpful text explaining its
fields.
* An elaborate output format building upon the concise one, and folding
out details in case of errors and staying out of view otherwise.
* Printing driver names for devices redirecting packets.
* Getting mac address for interface.
* Printing summarized total statistics for the entire session.
* Ability to dynamically switch between concise and verbose mode, using
SIGQUIT (Ctrl + \).

In later patches, the support will be extended for each tracepoint with
its own custom output in concise and verbose mode.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-4-memxor@gmail.com