Commit Graph

590 Commits

Author SHA1 Message Date
Luca Boccassi
d75fe9cb1d samples/bpf: Relicense bpf_insn.h as GPL-2.0-only OR BSD-2-Clause
libbpf and bpftool have been dual-licensed to facilitate inclusion in software
that is not compatible with GPL2-only (ie: Apache2), but the samples are still
GPL2-only.

Given these files are samples, they get naturally copied around. For example,
it is the case for samples/bpf/bpf_insn.h which was copied into the systemd
tree: https://github.com/systemd/systemd/blob/main/src/shared/linux/bpf_insn.h

Some more context on systemd's needs specifically:

  Most of systemd is (L)GPL2-or-later, which means there is no perceived
  incompatibility with Apache2 software and can thus be linked with
  OpenSSL 3.0. But given this GPL2-only header is included this is currently
  not possible. Dual-licensing this header solves this problem for us as we
  are scoping a move to OpenSSL 3.0, see:

  https://lists.freedesktop.org/archives/systemd-devel/2021-September/046882.html

Dual-license this header as GPL-2.0-only OR BSD-2-Clause to follow the same
licensing used by libbpf and bpftool:

  1bc38b8ff6 ("libbpf: relicense libbpf as LGPL-2.1 OR BSD-2-Clause")
  907b223651 ("tools: bpftool: dual license all files")

Signed-off-by: Luca Boccassi <bluca@debian.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Daniel Mack <daniel@zonque.org>
Acked-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Joe Stringer <joe@ovn.org>
Acked-by: Chenbo Feng <fengc@google.com>
Acked-by: Björn Töpel <bjorn@kernel.org>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Brendan Jackman <jackmanb@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210923000540.47344-1-luca.boccassi@gmail.com
2021-09-29 16:03:55 +02:00
Kumar Kartikeya Dwivedi
571fa247ab samples: bpf: Fix vmlinux.h generation for XDP samples
Generate vmlinux.h only from the in-tree vmlinux, and remove enum
declarations that would cause a build failure in case of version
mismatches.

There are now two options when building the samples:
1. Compile the kernel to use in-tree vmlinux for vmlinux.h
2. Override VMLINUX_BTF for samples using something like this:
   make VMLINUX_BTF=/sys/kernel/btf/vmlinux -C samples/bpf

This change was tested with relative builds, e.g. cases like:
 * make O=build -C samples/bpf
 * make KBUILD_OUTPUT=build -C samples/bpf
 * make -C samples/bpf
 * cd samples/bpf && make

When a suitable VMLINUX_BTF is not found, the following message is
printed:
/home/kkd/src/linux/samples/bpf/Makefile:333: *** Cannot find a vmlinux
for VMLINUX_BTF at any of "  ./vmlinux", build the kernel or set
VMLINUX_BTF variable.  Stop.

Fixes: 384b6b3bbf (samples: bpf: Add vmlinux.h generation support)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210928054608.1799021-1-memxor@gmail.com
2021-09-28 17:21:35 -07:00
Kumar Kartikeya Dwivedi
48b2e71c2e samples: bpf: Fix uninitialized variable in xdp_redirect_cpu
While at it, also improve help output when CPU number is greater than
possible.

Fixes: e531a220cc ("samples: bpf: Convert xdp_redirect_cpu to XDP samples helper")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210826120910.454081-1-memxor@gmail.com
2021-08-26 12:09:20 -07:00
Kumar Kartikeya Dwivedi
594a116b2a 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
2021-08-24 14:48:42 -07:00
Kumar Kartikeya Dwivedi
a29b3ca17e samples: bpf: Convert xdp_redirect_map_multi_kern.o to XDP samples helper
One of the notable changes is using a BPF_MAP_TYPE_HASH instead of array
map to store mac addresses of devices, as the resizing behavior was
based on max_ifindex, which unecessarily maximized the capacity of map
beyond what was needed.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-22-memxor@gmail.com
2021-08-24 14:48:42 -07:00
Kumar Kartikeya Dwivedi
bbe65865aa samples: bpf: Convert xdp_redirect_map to XDP samples helper
Use the libbpf skeleton facility and other utilities provided by XDP
samples helper.

Since get_mac_addr is already provided by XDP samples helper, we drop
it. Also convert to XDP samples helper similar to prior samples to
minimize duplication of code.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-21-memxor@gmail.com
2021-08-24 14:48:42 -07:00
Kumar Kartikeya Dwivedi
54af769db9 samples: bpf: Convert xdp_redirect_map_kern.o to XDP samples helper
Also update it to use consistent SEC("xdp") and SEC("xdp_devmap")
naming, and use global variable instead of BPF map for copying the mac
address.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-20-memxor@gmail.com
2021-08-24 14:48:42 -07:00
Kumar Kartikeya Dwivedi
e531a220cc samples: bpf: Convert xdp_redirect_cpu to XDP samples helper
Use the libbpf skeleton facility and other utilities provided by XDP
samples helper.

Similar to xdp_monitor, xdp_redirect_cpu was quite featureful except a
few minor omissions (e.g. redirect errno reporting). All of these have
been moved to XDP samples helper, hence drop the unneeded code and
convert to usage of helpers provided by it.

One of the important changes here is dropping of mprog-disable option,
as we make that the default. Also, we support built-in programs for some
common actions on the packet when it reaches kthread (pass, drop,
redirect to device). If the user still needs to install a custom
program, they can still supply a BPF object, however the program should
be suitably tagged with SEC("xdp_cpumap") annotation so that the
expected attach type is correct when updating our cpumap map element.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-19-memxor@gmail.com
2021-08-24 14:48:42 -07:00
Kumar Kartikeya Dwivedi
79ccf4529e samples: bpf: Convert xdp_redirect_cpu_kern.o to XDP samples helper
Similar to xdp_monitor_kern, a lot of these BPF programs have been
reimplemented properly consolidating missing features from other XDP
samples. Hence, drop the unneeded code and rename to .bpf.c suffix.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-18-memxor@gmail.com
2021-08-24 14:48:42 -07:00
Kumar Kartikeya Dwivedi
b926c55d85 samples: bpf: Convert xdp_redirect to XDP samples helper
Use the libbpf skeleton facility and other utilities provided by XDP
samples helper.

One important note:
The XDP samples helper handles ownership of installed XDP programs on
devices, including responding to SIGINT and SIGTERM, so drop the code
here and use the helpers we provide going forward for all xdp_redirect*
conversions.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-17-memxor@gmail.com
2021-08-24 14:48:42 -07:00
Kumar Kartikeya Dwivedi
66fc4ca85d samples: bpf: Convert xdp_redirect_kern.o to XDP samples helper
We moved swap_src_dst_mac to xdp_sample.bpf.h to be shared with other
potential users, so drop it while moving code to the new file.
Also, consistently use SEC("xdp") naming instead.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-16-memxor@gmail.com
2021-08-24 14:48:42 -07:00
Kumar Kartikeya Dwivedi
6e1051a54e samples: bpf: Convert xdp_monitor to XDP samples helper
Use the libbpf skeleton facility and other utilities provided by XDP
samples helper.

A lot of the code in xdp_monitor and xdp_redirect_cpu has been moved to
the xdp_sample_user.o helper, so we remove the duplicate functions here
that are no longer needed.

Thanks to BPF skeleton, we no longer depend on order of tracepoints to
uninstall them on startup. Instead, the sample mask is used to install
the needed tracepoints.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-15-memxor@gmail.com
2021-08-24 14:48:41 -07:00
Kumar Kartikeya Dwivedi
3f19956010 samples: bpf: Convert xdp_monitor_kern.o to XDP samples helper
We already moved all the functionality it provided in XDP samples helper
userspace and kernel BPF object, so just delete the unneeded code.

We also add generation of BPF skeleton and compilation using clang
-target bpf for files ending with .bpf.c suffix (to denote that they use
vmlinux.h).

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-14-memxor@gmail.com
2021-08-24 14:48:41 -07:00
Kumar Kartikeya Dwivedi
384b6b3bbf samples: bpf: Add vmlinux.h generation support
Also, take this opportunity to depend on in-tree bpftool, so that we can
use static linking support in subsequent commits for XDP samples BPF
helper object.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-13-memxor@gmail.com
2021-08-24 14:48:41 -07:00
Kumar Kartikeya Dwivedi
af93d58c27 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
2021-08-24 14:48:41 -07:00
Kumar Kartikeya Dwivedi
5f116212f4 samples: bpf: Add BPF support for devmap_xmit tracepoint
This adds support for the devmap_xmit tracepoint, and its multi device
variant that can be used to obtain streams for each individual
net_device to net_device redirection. This is useful for decomposing
total xmit stats in xdp_monitor.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-11-memxor@gmail.com
2021-08-24 14:48:41 -07:00
Kumar Kartikeya Dwivedi
d771e21750 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
2021-08-24 14:48:41 -07:00
Kumar Kartikeya Dwivedi
0cf3c2fc4b samples: bpf: Add BPF support for cpumap tracepoints
These are invoked in two places, when the XDP frame or SKB (for generic
XDP) enqueued to the ptr_ring (cpumap_enqueue) and when kthread processes
the frame after invoking the CPUMAP program for it (returning stats for
the batch).

We use cpumap_map_id to filter on the map_id as a way to avoid printing
incorrect stats for parallel sessions of xdp_redirect_cpu.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-9-memxor@gmail.com
2021-08-24 14:48:41 -07:00
Kumar Kartikeya Dwivedi
82c450803a 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
2021-08-24 14:48:41 -07:00
Kumar Kartikeya Dwivedi
451588764e samples: bpf: Add BPF support for xdp_exception tracepoint
This would allow us to store stats for each XDP action, including their
per-CPU counts. Consolidating this here allows all redirect samples to
detect xdp_exception events.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-7-memxor@gmail.com
2021-08-24 14:48:40 -07:00
Kumar Kartikeya Dwivedi
1d930fd2cd 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
2021-08-24 14:48:40 -07:00
Kumar Kartikeya Dwivedi
3231403894 samples: bpf: Add BPF support for redirect tracepoint
This adds the shared BPF file that will be used going forward for
sharing tracepoint programs among XDP redirect samples.

Since vmlinux.h conflicts with tools/include for READ_ONCE/WRITE_ONCE
and ARRAY_SIZE, they are copied in to xdp_sample.bpf.h along with other
helpers that will be required.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-5-memxor@gmail.com
2021-08-24 14:48:40 -07:00
Kumar Kartikeya Dwivedi
156f886cf6 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
2021-08-24 14:48:40 -07:00
Kumar Kartikeya Dwivedi
50b796e645 samples: bpf: Fix a couple of warnings
cookie_uid_helper_example.c: In function ‘main’:
cookie_uid_helper_example.c:178:69: warning: ‘ -j ACCEPT’ directive
	writing 10 bytes into a region of size between 8 and 58
	[-Wformat-overflow=]
  178 |  sprintf(rules, "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT",
      |								       ^~~~~~~~~~
/home/kkd/src/linux/samples/bpf/cookie_uid_helper_example.c:178:9: note:
	‘sprintf’ output between 53 and 103 bytes into a destination of size 100
  178 |  sprintf(rules, "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT",
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  179 |         file);
      |         ~~~~~

Fix by using snprintf and a sufficiently sized buffer.

tracex4_user.c:35:15: warning: ‘write’ reading 12 bytes from a region of
	size 11 [-Wstringop-overread]
   35 |         key = write(1, "\e[1;1H\e[2J", 12); /* clear screen */
      |               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Use size as 11.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210821002010.845777-2-memxor@gmail.com
2021-08-24 14:48:40 -07:00
Muhammad Falak R Wani
d1bf7c4d5d samples/bpf: Define MAX_ENTRIES instead of a magic number in offwaketime
Define MAX_ENTRIES instead of using 10000 as a magic number in various
places.

Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210815065013.15411-1-falakreyaz@gmail.com
2021-08-15 00:08:40 -07:00