Commit Graph

279 Commits

Author SHA1 Message Date
David Miller
1ad93ab10e bpf: Fix various lib and testsuite build failures on 32-bit.
Cannot cast a u64 to a pointer on 32-bit without an intervening (long)
cast otherwise GCC warns.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-28 16:10:59 -08:00
Andrey Ignatov
76d1b894c5 libbpf: Document API and ABI conventions
Document API and ABI for libbpf: naming convention, symbol visibility,
ABI versioning.

This is just a starting point. Documentation can be significantly
extended in the future to cover more topics.

ABI versioning section touches only a few basic points with a link to
more comprehensive documentation from Ulrich Drepper. This section can
be extended in the future when there is better understanding what works
well and what not so well in libbpf development process and production
usage.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-26 18:57:14 -08:00
Andrey Ignatov
306b267cb3 libbpf: Verify versioned symbols
Since ABI versioning info is kept separately from the code it's easy to
forget to update it while adding a new API.

Add simple verification that all global symbols exported with LIBBPF_API
are versioned in libbpf.map version script.

The idea is to check that number of global symbols in libbpf-in.o, that
is the input to the linker, matches with number of unique versioned
symbols in libbpf.so, that is the output of the linker. If these numbers
don't match, it may mean some symbol was not versioned and make will
fail.

"Unique" means that if a symbol is present in more than one version of
ABI due to ABI changes, it'll be counted once.

Another option to calculate number of global symbols in the "input"
could be to count number of LIBBPF_ABI entries in C headers but it seems
to be fragile.

Example of output when a symbol is missing in version script:

    ...
    LD       libbpf-in.o
    LINK     libbpf.a
    LINK     libbpf.so
  Warning: Num of global symbols in libbpf-in.o (115) does NOT match
  with num of versioned symbols in libbpf.so (114). Please make sure all
  LIBBPF_API symbols are versioned in libbpf.map.
  make: *** [check_abi] Error 1

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-26 18:57:14 -08:00
Andrey Ignatov
16192a771d libbpf: Add version script for DSO
More and more projects use libbpf and one day it'll likely be packaged
and distributed as DSO and that requires ABI versioning so that both
compatible and incompatible changes to ABI can be introduced in a safe
way in the future without breaking executables dynamically linked with a
previous version of the library.

Usual way to do ABI versioning is version script for the linker. Add
such a script for libbpf. All global symbols currently exported via
LIBBPF_API macro are added to the version script libbpf.map.

The version name LIBBPF_0.0.1 is constructed from the name of the
library + version specified by $(LIBBPF_VERSION) in Makefile.

Version script does not duplicate the work done by LIBBPF_API macro, it
rather complements it. The macro is used at compile time and can be used
by compiler to do optimization that can't be done at link time, it is
purely about global symbol visibility. The version script, in turn, is
used at link time and takes care of ABI versioning. Both techniques are
described in details in [1].

Whenever ABI is changed in the future, version script should be changed
appropriately.

[1] https://www.akkadia.org/drepper/dsohowto.pdf

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-26 18:57:14 -08:00
Martin KaFai Lau
1d2f44ca34 libbpf: Name changing for btf_get_from_id
s/btf_get_from_id/btf__get_from_id/ to restore the API naming convention.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-26 18:57:14 -08:00
Nikita V. Shirokov
47ae7e3d0b libbpf: make bpf_object__open default to UNSPEC
currently by default libbpf's bpf_object__open requires
bpf's program to specify  version in a code because of two things:
1) default prog type is set to KPROBE
2) KPROBE requires (in kernel/bpf/syscall.c) version to be specified

in this patch i'm changing default prog type to UNSPEC and also changing
requirments for version's section to be present in object file.
now it would reflect what we have today in kernel
(only KPROBE prog type requires for version to be explicitly set).

v1 -> v2:
 - RFC tag has been dropped

Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-23 22:27:05 +01:00
Nikita V. Shirokov
addb9fc90f bpf: adding support for map in map in libbpf
idea is pretty simple. for specified map (pointed by struct bpf_map)
we would provide descriptor of already loaded map, which is going to be
used as a prototype for inner map. proposed workflow:
1) open bpf's object (bpf_object__open)
2) create bpf's map which is going to be used as a prototype
3) find (by name) map-in-map which you want to load and update w/
descriptor of inner map w/ a new helper from this patch
4) load bpf program w/ bpf_object__load

Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21 23:33:21 +01:00
Stanislav Fomichev
5b32a23e1d bpf: libbpf: don't specify prog name if kernel doesn't support it
Use recently added capability check.

See commit 23499442c3 ("bpf: libbpf: retry map creation without
the name") for rationale.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21 23:26:14 +01:00
Stanislav Fomichev
94cb310cfa bpf: libbpf: remove map name retry from bpf_create_map_xattr
Instead, check for a newly created caps.name bpf_object capability.
If kernel doesn't support names, don't specify the attribute.

See commit 23499442c3 ("bpf: libbpf: retry map creation without
the name") for rationale.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21 23:26:04 +01:00
Stanislav Fomichev
47eff61777 bpf, libbpf: introduce bpf_object__probe_caps to test BPF capabilities
It currently only checks whether kernel supports map/prog names.
This capability check will be used in the next two commits to
skip setting prog/map names.

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21 23:25:33 +01:00
Stanislav Fomichev
8c4905b995 libbpf: make sure bpf headers are c++ include-able
Wrap headers in extern "C", to turn off C++ mangling.
This simplifies including libbpf in c++ and linking against it.

v2 changes:
* do the same for btf.h

v3 changes:
* test_libbpf.cpp to test for possible future c++ breakages

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21 23:15:41 +01:00
Yonghong Song
462c124c59 bpf: fix a libbpf loader issue
Commit 2993e0515b ("tools/bpf: add support to read .BTF.ext sections")
added support to read .BTF.ext sections from an object file, create
and pass prog_btf_fd and func_info to the kernel.

The program btf_fd (prog->btf_fd) is initialized to be -1 to please
zclose so we do not need special handling dur prog close.
Passing -1 to the kernel, however, will cause loading error.
Passing btf_fd 0 to the kernel if prog->btf_fd is invalid
fixed the problem.

Fixes: 2993e0515b ("tools/bpf: add support to read .BTF.ext sections")
Reported-by: Andrey Ignatov <rdna@fb.com>
Reported-by: Emre Cantimur <haydum@fb.com>
Tested-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21 22:22:17 +01:00
Yonghong Song
d7f5b5e051 tools/bpf: refactor to implement btf_get_from_id() in lib/bpf
The function get_btf() is implemented in tools/bpf/bpftool/map.c
to get a btf structure given a map_info. This patch
refactored this function to be function btf_get_from_id()
in tools/lib/bpf so that it can be used later.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-20 10:54:39 -08:00
Yonghong Song
2993e0515b tools/bpf: add support to read .BTF.ext sections
The .BTF section is already available to encode types.
These types can be used for map
pretty print. The whole .BTF will be passed to the
kernel as well for which kernel can verify and return
to the user space for pretty print etc.

The llvm patch at https://reviews.llvm.org/D53736
will generate .BTF section and one more section .BTF.ext.
The .BTF.ext section encodes function type
information and line information. Note that
this patch set only supports function type info.
The functionality is implemented in libbpf.

The .BTF section can be directly loaded into the
kernel, and the .BTF.ext section cannot. The loader
may need to do some relocation and merging,
similar to merging multiple code sections, before
loading into the kernel.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-20 10:54:39 -08:00
Yonghong Song
7e0d0fb552 tools/bpf: add new fields for program load in lib/bpf
The new fields are added for program load in lib/bpf so
application uses api bpf_load_program_xattr() is able
to load program with btf and func_info data.

This functionality will be used in next patch
by bpf selftest test_btf.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-20 10:54:39 -08:00
Martin KaFai Lau
78a2540e89 tools/bpf: Add tests for BTF_KIND_FUNC_PROTO and BTF_KIND_FUNC
This patch adds unit tests for BTF_KIND_FUNC_PROTO and
BTF_KIND_FUNC to test_btf.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-20 10:54:38 -08:00
Stanislav Fomichev
23499442c3 bpf: libbpf: retry map creation without the name
Since commit 88cda1c9da ("bpf: libbpf: Provide basic API support
to specify BPF obj name"), libbpf unconditionally sets bpf_attr->name
for maps. Pre v4.14 kernels don't know about map names and return an
error about unexpected non-zero data. Retry sys_bpf without a map
name to cover older kernels.

v2 changes:
* check for errno == EINVAL as suggested by Daniel Borkmann

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-20 00:49:32 +01:00
Martin KaFai Lau
a83d6e76a6 bpf: libbpf: Fix bpf_program__next() API
This patch restores the behavior in
commit eac7d84519 ("tools: libbpf: don't return '.text' as a program for multi-function programs")
such that bpf_program__next() does not return pseudo programs in ".text".

Fixes: 0c19a9fbc9 ("libbpf: cleanup after partial failure in bpf_object__pin")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-16 17:46:54 -08:00
Stanislav Fomichev
33a2c75c55 libbpf: add internal pin_name
pin_name is the same as section_name where '/' is replaced
by '_'. bpf_object__pin_programs is converted to use pin_name
to avoid the situation where section_name would require creating another
subdirectory for a pin (as, for example, when calling bpf_object__pin_programs
for programs in sections like "cgroup/connect6").

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-10 15:56:11 -08:00
Stanislav Fomichev
fd734c5cca libbpf: bpf_program__pin: add special case for instances.nr == 1
When bpf_program has only one instance, don't create a subdirectory with
per-instance pin files (<prog>/0). Instead, just create a single pin file
for that single instance. This simplifies object pinning by not creating
unnecessary subdirectories.

This can potentially break existing users that depend on the case
where '/0' is always created. However, I couldn't find any serious
usage of bpf_program__pin inside the kernel tree and I suppose there
should be none outside.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-10 15:56:10 -08:00
Stanislav Fomichev
0c19a9fbc9 libbpf: cleanup after partial failure in bpf_object__pin
bpftool will use bpf_object__pin in the next commits to pin all programs
and maps from the file; in case of a partial failure, we need to get
back to the clean state (undo previous program/map pins).

As part of a cleanup, I've added and exported separate routines to
pin all maps (bpf_object__pin_maps) and progs (bpf_object__pin_programs)
of an object.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-10 15:56:10 -08:00
Andrey Ignatov
3615353218 libbpf: Fix compile error in libbpf_attach_type_by_name
Arnaldo Carvalho de Melo reported build error in libbpf when clang
version 3.8.1-24 (tags/RELEASE_381/final) is used:

libbpf.c:2201:36: error: comparison of constant -22 with expression of
type 'const enum bpf_attach_type' is always false
[-Werror,-Wtautological-constant-out-of-range-compare]
                if (section_names[i].attach_type == -EINVAL)
                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^  ~~~~~~~
1 error generated.

Fix the error by keeping "is_attachable" property of a program in a
separate struct field instead of trying to use attach_type itself.

Fixes: 956b620fcf ("libbpf: Introduce libbpf_attach_type_by_name")
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-31 23:06:17 +01:00
Daniel Borkmann
3dca21156b bpf, libbpf: simplify and cleanup perf ring buffer walk
Simplify bpf_perf_event_read_simple() a bit and fix up some minor
things along the way: the return code in the header is not of type
int but enum bpf_perf_event_ret instead. Once callback indicated
to break the loop walking event data, it also needs to be consumed
in data_tail since it has been processed already.

Moreover, bpf_perf_event_print_t callback should avoid void * as
we actually get a pointer to struct perf_event_header and thus
applications can make use of container_of() to have type checks.
The walk also doesn't have to use modulo op since the ring size is
required to be power of two.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-20 23:13:32 -07:00
Daniel Borkmann
a64af0ef1c bpf, libbpf: use correct barriers in perf ring buffer walk
Given libbpf is a generic library and not restricted to x86-64 only,
the compiler barrier in bpf_perf_event_read_simple() after fetching
the head needs to be replaced with smp_rmb() at minimum. Also, writing
out the tail we should use WRITE_ONCE() to avoid store tearing.

Now that we have the logic in place in ring_buffer_read_head() and
ring_buffer_write_tail() helper also used by perf tool which would
select the correct and best variant for a given architecture (e.g.
x86-64 can avoid CPU barriers entirely), make use of these in order
to fix bpf_perf_event_read_simple().

Fixes: d0cabbb021 ("tools: bpf: move the event reading loop to libbpf")
Fixes: 39111695b1 ("samples: bpf: add bpf_perf_event_output example")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-19 13:43:08 -07:00
Mauricio Vasquez B
43b987d23d selftests/bpf: add test cases for queue and stack maps
test_maps:
Tests that queue/stack maps are behaving correctly even in corner cases

test_progs:
Tests new ebpf helpers

Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-19 13:24:31 -07:00
Andrey Ignatov
ab9e084821 libbpf: Per-symbol visibility for DSO
Make global symbols in libbpf DSO hidden by default with
-fvisibility=hidden and export symbols that are part of ABI explicitly
with __attribute__((visibility("default"))).

This is common practice that should prevent from accidentally exporting
a symbol, that is not supposed to be a part of ABI what, in turn,
improves both libbpf developer- and user-experiences. See [1] for more
details.

Export control becomes more important since more and more projects use
libbpf.

The patch doesn't export a bunch of netlink related functions since as
agreed in [2] they'll be reworked. That doesn't break bpftool since
bpftool links libbpf statically.

[1] https://www.akkadia.org/drepper/dsohowto.pdf (2.2 Export Control)
[2] https://www.mail-archive.com/netdev@vger.kernel.org/msg251434.html

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-16 15:16:47 -07:00
John Fastabend
c034a177d3 bpf: bpftool, add flag to allow non-compat map definitions
Multiple map definition structures exist and user may have non-zero
fields in their definition that are not recognized by bpftool and
libbpf. The normal behavior is to then fail loading the map. Although
this is a good default behavior users may still want to load the map
for debugging or other reasons. This patch adds a --mapcompat flag
that can be used to override the default behavior and allow loading
the map even when it has additional non-zero fields.

For now the only user is 'bpftool prog' we can switch over other
subcommands as needed. The library exposes an API that consumes
a flags field now but I kept the original API around also in case
users of the API don't want to expose this. The flags field is an
int in case we need more control over how the API call handles
errors/features/etc in the future.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-15 16:13:14 -07:00
Yonghong Song
438363c0fe tools/bpf: use proper type and uapi perf_event.h header for libbpf
Use __u32 instead u32 in libbpf.c and also use
uapi perf_event.h instead of tools/perf/perf-sys.h.

Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-09 22:03:28 -07:00
Alexei Starovoitov
1bc38b8ff6 libbpf: relicense libbpf as LGPL-2.1 OR BSD-2-Clause
libbpf is maturing as a library and gaining features that no other bpf libraries support
(BPF Type Format, bpf to bpf calls, etc)
Many Apache2 licensed projects (like bcc, bpftrace, gobpf, cilium, etc)
would like to use libbpf, but cannot do this yet, since Apache Foundation explicitly
states that LGPL is incompatible with Apache2.
Hence let's relicense libbpf as dual license LGPL-2.1 or BSD-2-Clause,
since BSD-2 is compatible with Apache2.
Dual LGPL or Apache2 is invalid combination.
Fix license mistake in Makefile as well.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Beckett <david.beckett@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Joe Stringer <joe@ovn.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-08 10:09:48 +02:00
Andrey Ignatov
e5b0863c20 libbpf: Use __u32 instead of u32 in bpf_program__load
Make bpf_program__load consistent with other interfaces: use __u32
instead of u32. That in turn fixes build of samples:

In file included from ./samples/bpf/trace_output_user.c:21:0:
./tools/lib/bpf/libbpf.h:132:9: error: unknown type name ‘u32’
         u32 kern_version);
         ^

Fixes: commit 29cd77f416 ("libbpf: Support loading individual progs")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-04 16:04:16 +02:00
Andrey Ignatov
eff8190880 libbpf: Make include guards consistent
Rename include guards to have consistent names "__LIBBPF_<header_name>".

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-04 16:04:16 +02:00
Andrey Ignatov
24d6a80842 libbpf: Consistent prefixes for interfaces in str_error.h.
libbpf is used more and more outside kernel tree. That means the library
should follow good practices in library design and implementation to
play well with third party code that uses it.

One of such practices is to have a common prefix (or a few) for every
interface, function or data structure, library provides. I helps to
avoid name conflicts with other libraries and keeps API consistent.

Inconsistent names in libbpf already cause problems in real life. E.g.
an application can't use both libbpf and libnl due to conflicting
symbols.

Having common prefix will help to fix current and avoid future problems.

libbpf already uses the following prefixes for its interfaces:
* bpf_ for bpf system call wrappers, program/map/elf-object
  abstractions and a few other things;
* btf_ for BTF related API;
* libbpf_ for everything else.

The patch renames function in str_error.h to have libbpf_ prefix since it
misses one and doesn't fit well into the first two categories.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-04 16:04:16 +02:00
Andrey Ignatov
f04bc8a436 libbpf: Consistent prefixes for interfaces in nlattr.h.
libbpf is used more and more outside kernel tree. That means the library
should follow good practices in library design and implementation to
play well with third party code that uses it.

One of such practices is to have a common prefix (or a few) for every
interface, function or data structure, library provides. I helps to
avoid name conflicts with other libraries and keeps API consistent.

Inconsistent names in libbpf already cause problems in real life. E.g.
an application can't use both libbpf and libnl due to conflicting
symbols.

Having common prefix will help to fix current and avoid future problems.

libbpf already uses the following prefixes for its interfaces:
* bpf_ for bpf system call wrappers, program/map/elf-object
  abstractions and a few other things;
* btf_ for BTF related API;
* libbpf_ for everything else.

The patch adds libbpf_ prefix to interfaces in nlattr.h that use none of
mentioned above prefixes and doesn't fit well into the first two
categories.

Since affected part of API is used in bpftool, the patch applies
corresponding change to bpftool as well. Having it in a separate patch
will cause a state of tree where bpftool is broken what may not be a
good idea.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-04 16:04:16 +02:00
Andrey Ignatov
aae5778010 libbpf: Consistent prefixes for interfaces in libbpf.h.
libbpf is used more and more outside kernel tree. That means the library
should follow good practices in library design and implementation to
play well with third party code that uses it.

One of such practices is to have a common prefix (or a few) for every
interface, function or data structure, library provides. I helps to
avoid name conflicts with other libraries and keeps API consistent.

Inconsistent names in libbpf already cause problems in real life. E.g.
an application can't use both libbpf and libnl due to conflicting
symbols.

Having common prefix will help to fix current and avoid future problems.

libbpf already uses the following prefixes for its interfaces:
* bpf_ for bpf system call wrappers, program/map/elf-object
  abstractions and a few other things;
* btf_ for BTF related API;
* libbpf_ for everything else.

The patch adds libbpf_ prefix to functions and typedef in libbpf.h that
use none of mentioned above prefixes and doesn't fit well into the first
two categories.

Since affected part of API is used in bpftool, the patch applies
corresponding change to bpftool as well. Having it in a separate patch
will cause a state of tree where bpftool is broken what may not be a
good idea.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-04 16:04:16 +02:00
Andrey Ignatov
434fe9d4b4 libbpf: Move __dump_nlmsg_t from API to implementation
This typedef is used only by implementation in netlink.c. Nothing uses
it in public API. Move it to netlink.c.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-04 16:04:15 +02:00
Joe Stringer
29cd77f416 libbpf: Support loading individual progs
Allow the individual program load to be invoked. This will help with
testing, where a single ELF may contain several sections, some of which
denote subprograms that are expected to fail verification, along with
some which are expected to pass verification. By allowing programs to be
iterated and individually loaded, each program can be independently
checked against its expected verification result.

Signed-off-by: Joe Stringer <joe@wand.net.nz>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-03 02:53:48 +02:00
Andrey Ignatov
c6f6851b28 libbpf: Support sk_skb/stream_{parser, verdict} section names
Add section names for BPF_SK_SKB_STREAM_PARSER and
BPF_SK_SKB_STREAM_VERDICT attach types to be able to identify them in
libbpf_attach_type_by_name.

"stream_parser" and "stream_verdict" are used instead of simple "parser"
and "verdict" just to avoid possible confusion in a place where attach
type is used alone (e.g. in bpftool's show sub-commands) since there is
another attach point that can be named as "verdict": BPF_SK_MSG_VERDICT.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-09-27 21:14:59 +02:00
Andrey Ignatov
bafa7afe63 libbpf: Support cgroup_skb/{e,in}gress section names
Add section names for BPF_CGROUP_INET_INGRESS and BPF_CGROUP_INET_EGRESS
attach types to be able to identify them in libbpf_attach_type_by_name.

"cgroup_skb" is used instead of "cgroup/skb" mostly to easy possible
unifying of how libbpf and bpftool works with section names:
* bpftool uses "cgroup_skb" to in "prog list" sub-command;
* bpftool uses "ingress" and "egress" in "cgroup list" sub-command;
* having two parts instead of three in a string like "cgroup_skb/ingress"
  can be leveraged to split it to prog_type part and attach_type part,
  or vise versa: use two parts to make a section name.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-09-27 21:14:59 +02:00
Andrey Ignatov
956b620fcf libbpf: Introduce libbpf_attach_type_by_name
There is a common use-case when ELF object contains multiple BPF
programs and every program has its own section name. If it's cgroup-bpf
then programs have to be 1) loaded and 2) attached to a cgroup.

It's convenient to have information necessary to load BPF program
together with program itself. This is where section name works fine in
conjunction with libbpf_prog_type_by_name that identifies prog_type and
expected_attach_type and these can be used with BPF_PROG_LOAD.

But there is currently no way to identify attach_type by section name
and it leads to messy code in user space that reinvents guessing logic
every time it has to identify attach type to use with BPF_PROG_ATTACH.

The patch introduces libbpf_attach_type_by_name that guesses attach type
by section name if a program can be attached.

The difference between expected_attach_type provided by
libbpf_prog_type_by_name and attach_type provided by
libbpf_attach_type_by_name is the former is used at BPF_PROG_LOAD time
and can be zero if a program of prog_type X has only one corresponding
attach type Y whether the latter provides specific attach type to use
with BPF_PROG_ATTACH.

No new section names were added to section_names array. Only existing
ones were reorganized and attach_type was added where appropriate.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-09-27 21:14:59 +02:00
David S. Miller
105bc1306e Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-09-25

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Allow for RX stack hardening by implementing the kernel's flow
   dissector in BPF. Idea was originally presented at netconf 2017 [0].
   Quote from merge commit:

     [...] Because of the rigorous checks of the BPF verifier, this
     provides significant security guarantees. In particular, the BPF
     flow dissector cannot get inside of an infinite loop, as with
     CVE-2013-4348, because BPF programs are guaranteed to terminate.
     It cannot read outside of packet bounds, because all memory accesses
     are checked. Also, with BPF the administrator can decide which
     protocols to support, reducing potential attack surface. Rarely
     encountered protocols can be excluded from dissection and the
     program can be updated without kernel recompile or reboot if a
     bug is discovered. [...]

   Also, a sample flow dissector has been implemented in BPF as part
   of this work, from Petar and Willem.

   [0] http://vger.kernel.org/netconf2017_files/rx_hardening_and_udp_gso.pdf

2) Add support for bpftool to list currently active attachment
   points of BPF networking programs providing a quick overview
   similar to bpftool's perf subcommand, from Yonghong.

3) Fix a verifier pruning instability bug where a union member
   from the register state was not cleared properly leading to
   branches not being pruned despite them being valid candidates,
   from Alexei.

4) Various smaller fast-path optimizations in XDP's map redirect
   code, from Jesper.

5) Enable to recognize BPF_MAP_TYPE_REUSEPORT_SOCKARRAY maps
   in bpftool, from Roman.

6) Remove a duplicate check in libbpf that probes for function
   storage, from Taeung.

7) Fix an issue in test_progs by avoid checking for errno since
   on success its value should not be checked, from Mauricio.

8) Fix unused variable warning in bpf_getsockopt() helper when
   CONFIG_INET is not configured, from Anders.

9) Fix a compilation failure in the BPF sample code's use of
   bpf_flow_keys, from Prashant.

10) Minor cleanups in BPF code, from Yue and Zhong.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-09-25 20:29:38 -07:00
Arnaldo Carvalho de Melo
6d41907c63 tools lib bpf: Provide wrapper for strerror_r to build in !_GNU_SOURCE systems
Same problem that got fixed in a similar fashion in tools/perf/ in
c8b5f2c96d ("tools: Introduce str_error_r()"), fix it in the same
way, licensing needs to be sorted out to libbpf to use libapi, so,
for this simple case, just get the same wrapper in tools/lib/bpf.

This makes libbpf and its users (bpftool, selftests, perf) to build
again in Alpine Linux 3.[45678] and edge.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Quentin Monnet <quentin.monnet@netronome.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Yonghong Song <yhs@fb.com>
Fixes: 1ce6a9fc15 ("bpf: fix build error in libbpf with EXTRA_CFLAGS="-Wp, -D_FORTIFY_SOURCE=2 -O2"")
Link: https://lkml.kernel.org/r/20180917151636.GA21790@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-09-18 10:16:18 -03:00
Petar Penkov
c22fbae76c bpf: support flow dissector in libbpf and bpftool
This patch extends libbpf and bpftool to work with programs of type
BPF_PROG_TYPE_FLOW_DISSECTOR.

Signed-off-by: Petar Penkov <ppenkov@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-09-14 12:04:33 -07:00
Yonghong Song
9d0b3c1f14 tools/bpf: fix a netlink recv issue
Commit f7010770fb ("tools/bpf: move bpf/lib netlink related
functions into a new file") introduced a while loop for the
netlink recv path. This while loop is needed since the
buffer in recv syscall may not be enough to hold all the
information and in such cases multiple recv calls are needed.

There is a bug introduced by the above commit as
the while loop may block on recv syscall if there is no
more messages are expected. The netlink message header
flag NLM_F_MULTI is used to indicate that more messages
are expected and this patch fixed the bug by doing
further recv syscall only if multipart message is expected.

The patch added another fix regarding to message length of 0.
When netlink recv returns message length of 0, there will be
no more messages for returning data so the while loop
can end.

Fixes: f7010770fb ("tools/bpf: move bpf/lib netlink related functions into a new file")
Reported-by: Björn Töpel <bjorn.topel@intel.com>
Tested-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-09-11 14:26:30 -07:00
Yonghong Song
36f1678d9e tools/bpf: add more netlink functionalities in lib/bpf
This patch added a few netlink attribute parsing functions
and the netlink API functions to query networking links, tc classes,
tc qdiscs and tc filters. For example, the following API is
to get networking links:
  int nl_get_link(int sock, unsigned int nl_pid,
                  dump_nlmsg_t dump_link_nlmsg,
                  void *cookie);

Note that when the API is called, the user also provided a
callback function with the following signature:
  int (*dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);

The "cookie" is the parameter the user passed to the API and will
be available for the callback function.
The "msg" is the information about the result, e.g., ifinfomsg or
tcmsg. The "tb" is the parsed netlink attributes.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-09-06 22:34:08 -07:00
Yonghong Song
f7010770fb tools/bpf: move bpf/lib netlink related functions into a new file
There are no functionality change for this patch.

In the subsequent patches, more netlink related library functions
will be added and a separate file is better than cluttering bpf.c.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-09-06 22:34:08 -07:00
Taeung Song
69495d2a52 libbpf: Remove the duplicate checking of function storage
After the commit eac7d84519 ("tools: libbpf: don't return '.text'
as a program for multi-function programs"), bpf_program__next()
in bpf_object__for_each_program skips the function storage such as .text,
so eliminate the duplicate checking.

Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-09-05 22:16:00 -07:00
David S. Miller
c1617fb4c5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-08-13

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add driver XDP support for veth. This can be used in conjunction with
   redirect of another XDP program e.g. sitting on NIC so the xdp_frame
   can be forwarded to the peer veth directly without modification,
   from Toshiaki.

2) Add a new BPF map type REUSEPORT_SOCKARRAY and prog type SK_REUSEPORT
   in order to provide more control and visibility on where a SO_REUSEPORT
   sk should be located, and the latter enables to directly select a sk
   from the bpf map. This also enables map-in-map for application migration
   use cases, from Martin.

3) Add a new BPF helper bpf_skb_ancestor_cgroup_id() that returns the id
   of cgroup v2 that is the ancestor of the cgroup associated with the
   skb at the ancestor_level, from Andrey.

4) Implement BPF fs map pretty-print support based on BTF data for regular
   hash table and LRU map, from Yonghong.

5) Decouple the ability to attach BTF for a map from the key and value
   pretty-printer in BPF fs, and enable further support of BTF for maps for
   percpu and LPM trie, from Daniel.

6) Implement a better BPF sample of using XDP's CPU redirect feature for
   load balancing SKB processing to remote CPU. The sample implements the
   same XDP load balancing as Suricata does which is symmetric hash based
   on IP and L4 protocol, from Jesper.

7) Revert adding NULL pointer check with WARN_ON_ONCE() in __xdp_return()'s
   critical path as it is ensured that the allocator is present, from Björn.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-13 10:07:23 -07:00
David S. Miller
6a92ef08a1 Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-11 17:52:00 -07:00
Martin KaFai Lau
91134d849a bpf: Test BPF_PROG_TYPE_SK_REUSEPORT
This patch add tests for the new BPF_PROG_TYPE_SK_REUSEPORT.

The tests cover:
- IPv4/IPv6 + TCP/UDP
- TCP syncookie
- TCP fastopen
- Cases when the bpf_sk_select_reuseport() returning errors
- Cases when the bpf prog returns SK_DROP
- Values from sk_reuseport_md
- outer_map => reuseport_array

The test depends on
commit 3eee1f75f2 ("bpf: fix bpf_skb_load_bytes_relative pkt length check")

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-11 01:58:46 +02:00
Martin KaFai Lau
6bc8529c41 bpf: test BPF_MAP_TYPE_REUSEPORT_SOCKARRAY
This patch adds tests for the new BPF_MAP_TYPE_REUSEPORT_SOCKARRAY.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-11 01:58:46 +02:00
David S. Miller
1ba982806c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-08-07

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add cgroup local storage for BPF programs, which provides a fast
   accessible memory for storing various per-cgroup data like number
   of transmitted packets, etc, from Roman.

2) Support bpf_get_socket_cookie() BPF helper in several more program
   types that have a full socket available, from Andrey.

3) Significantly improve the performance of perf events which are
   reported from BPF offload. Also convert a couple of BPF AF_XDP
   samples overto use libbpf, both from Jakub.

4) seg6local LWT provides the End.DT6 action, which allows to
   decapsulate an outer IPv6 header containing a Segment Routing Header.
   Adds this action now to the seg6local BPF interface, from Mathieu.

5) Do not mark dst register as unbounded in MOV64 instruction when
   both src and dst register are the same, from Arthur.

6) Define u_smp_rmb() and u_smp_wmb() to their respective barrier
   instructions on arm64 for the AF_XDP sample code, from Brian.

7) Convert the tcp_client.py and tcp_server.py BPF selftest scripts
   over from Python 2 to Python 3, from Jeremy.

8) Enable BTF build flags to the BPF sample code Makefile, from Taeung.

9) Remove an unnecessary rcu_read_lock() in run_lwt_bpf(), from Taehee.

10) Several improvements to the README.rst from the BPF documentation
    to make it more consistent with RST format, from Tobin.

11) Replace all occurrences of strerror() by calls to strerror_r()
    in libbpf and fix a FORTIFY_SOURCE build error along with it,
    from Thomas.

12) Fix a bug in bpftool's get_btf() function to correctly propagate
    an error via PTR_ERR(), from Yue.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-07 11:02:05 -07:00
Martin KaFai Lau
74682128c6 bpf: btf: Change tools/lib/bpf/btf to LGPL
This patch changes the tools/lib/bpf/btf.[ch] to LGPL which
is inline with libbpf also.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-08-06 08:44:48 +02:00
Jakub Kicinski
6534770d6f tools: bpf: fix BTF code added twice to different trees
commit 38d5d3b3d5 ("bpf: Introduce BPF_ANNOTATE_KV_PAIR")

added to the bpf and net trees what

commit 92b57121ca ("bpf: btf: export btf types and name by offset from lib")

has already added to bpf-next/net-next, but in slightly different
location.  Remove the duplicates (to fix build of libbpf).

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-02 19:45:14 -07:00
David S. Miller
89b1698c93 Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net
The BTF conflicts were simple overlapping changes.

The virtio_net conflict was an overlap of a fix of statistics counter,
happening alongisde a move over to a bonafide statistics structure
rather than counting value on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-02 10:55:32 -07:00
Thomas Richter
1ce6a9fc15 bpf: fix build error in libbpf with EXTRA_CFLAGS="-Wp, -D_FORTIFY_SOURCE=2 -O2"
Commit 531b014e7a ("tools: bpf: make use of reallocarray") causes
a compiler error when building the perf tool in the linux-next tree.
Compile file tools/lib/bpf/libbpf.c on a FEDORA 28 installation with
gcc compiler version: gcc (GCC) 8.0.1 20180324 (Red Hat 8.0.1-0.20)
shows this error message:

  [root@p23lp27] # make V=1 EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2"
  [...]
  make -f /home6/tmricht/linux-next/tools/build/Makefile.build
  	dir=./util/scripting-engines obj=libperf
  libbpf.c: In function ‘bpf_object__elf_collect’:
  libbpf.c:811:15: error: ignoring return value of ‘strerror_r’,
  		declared with attribute warn_unused_result [-Werror=unused-result]
       strerror_r(-err, errmsg, sizeof(errmsg));
                 ^
  cc1: all warnings being treated as errors
  mv: cannot stat './.libbpf.o.tmp': No such file or directory
  /home6/tmricht/linux-next/tools/build/Makefile.build:96: recipe for target 'libbpf.o' failed

Replace all occurrences of strerror() by calls to strerror_r(). To
keep the compiler quiet also use the return value from strerror_r()
otherwise a 'variable set but not use' warning which is treated as
error terminates the compile.

Fixes: 531b014e7a ("tools: bpf: make use of reallocarray")
Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-31 02:08:55 +02:00
Thomas Richter
b611da43b6 perf build: Build error in libbpf missing initialization
In linux-next tree compiling the perf tool with additional make flags
EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2" causes a compiler error.
It is the warning 'variable may be used uninitialized' which is treated
as error: I compile it using a FEDORA 28 installation, my gcc compiler
version: gcc (GCC) 8.0.1 20180324 (Red Hat 8.0.1-0.20). The file that
causes the error is tools/lib/bpf/libbpf.c.

  [root@p23lp27] # make V=1 EXTRA_CFLAGS="-Wp,-D_FORTIFY_SOURCE=2 -O2"
  [...]
  Makefile.config:849: No openjdk development package found, please
     install JDK package, e.g. openjdk-8-jdk, java-1.8.0-openjdk-devel
  Warning: Kernel ABI header at 'tools/include/uapi/linux/if_link.h'
          differs from latest version at 'include/uapi/linux/if_link.h'
    CC       libbpf.o
  libbpf.c: In function ‘bpf_perf_event_read_simple’:
  libbpf.c:2342:6: error: ‘ret’ may be used uninitialized in this
  			function [-Werror=maybe-uninitialized]
    int ret;
        ^
  cc1: all warnings being treated as errors
  mv: cannot stat './.libbpf.o.tmp': No such file or directory
  /home6/tmricht/linux-next/tools/build/Makefile.build:96: recipe for target 'libbpf.o' failed

Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-28 21:22:40 +02:00
Jakub Kicinski
6d4b198b0b tools: libbpf: add bpf_object__find_program_by_title()
Allow users to find programs by section names.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-27 07:18:44 +02:00
Jakub Kicinski
1e960043e8 tools: libbpf: handle NULL program gracefully in bpf_program__nth_fd()
bpf_map__fd() handles NULL map gracefully and returns -EINVAL.
bpf_program__fd() and bpf_program__nth_fd() crash in this case.
Make the behaviour more consistent by validating prog pointer
as well.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-27 07:18:44 +02:00
Martin KaFai Lau
38d5d3b3d5 bpf: Introduce BPF_ANNOTATE_KV_PAIR
This patch introduces BPF_ANNOTATE_KV_PAIR to signal the
bpf loader about the btf key_type and value_type of a bpf map.
Please refer to the changes in test_btf_haskv.c for its usage.
Both iproute2 and libbpf loader will then have the same
convention to find out the map's btf_key_type_id and
btf_value_type_id from a map's name.

Fixes: 8a138aed4a ("bpf: btf: Add BTF support to libbpf")
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25 06:57:55 +02:00
Martin KaFai Lau
5b891af7fc bpf: Replace [u]int32_t and [u]int64_t in libbpf
This patch replaces [u]int32_t and [u]int64_t usage with
__[su]32 and __[su]64.  The same change goes for [u]int16_t
and [u]int8_t.

Fixes: 8a138aed4a ("bpf: btf: Add BTF support to libbpf")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-25 06:57:55 +02:00
Jakub Kicinski
b4b5bffd6c tools: libbpf: remove libelf-getphdrnum feature detection
libbpf does not depend on libelf-getphdrnum feature, don't check it.

$ git grep HAVE_ELF_GETPHDRNUM_SUPPORT
tools/perf/Makefile.config:    CFLAGS += -DHAVE_ELF_GETPHDRNUM_SUPPORT
tools/perf/util/symbol-elf.c:#ifndef HAVE_ELF_GETPHDRNUM_SUPPORT

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-07-16 16:36:49 -07:00
Okash Khawaja
92b57121ca bpf: btf: export btf types and name by offset from lib
This patch introduces btf__resolve_type() function and exports two
existing functions from libbpf. btf__resolve_type follows modifier
types like const and typedef until it hits a type which actually takes
up memory, and then returns it. This function follows similar pattern
to btf__resolve_size but instead of computing size, it just returns
the type.

These  functions will be used in the followig patch which parses
information inside array of `struct btf_type *`. btf_name_by_offset is
used for printing variable names.

Signed-off-by: Okash Khawaja <osk@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-14 13:00:40 +02:00
Jakub Kicinski
26736eb9a4 tools: libbpf: allow map reuse
More advanced applications may want to only replace programs without
destroying associated maps.  Allow libbpf users to achieve that.
Instead of always creating all of the maps at load time, expose to
users an API to reconstruct the map object from already existing
map.

The map parameters are read from the kernel and replace the parameters
of the ELF map.  libbpf does not restrict the map replacement, i.e.
the reused map does not have to be compatible with the ELF map
definition.  We relay on the verifier for checking the compatibility
between maps and programs.  The ELF map definition is completely
overwritten by the information read from the kernel, to make sure
libbpf's view of map object corresponds to the actual map.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:34 +02:00
Jakub Kicinski
531b014e7a tools: bpf: make use of reallocarray
reallocarray() is a safer variant of realloc which checks for
multiplication overflow in case of array allocation.  Since it's
not available in Glibc < 2.26 import kernel's overflow.h and
add a static inline implementation when needed.  Use feature
detection to probe for existence of reallocarray.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:34 +02:00
Jakub Kicinski
8d13406c02 tools: libbpf: move library error code into a separate file
libbpf_strerror() depends on XSI-compliant (POSIX) version of
strerror_r(), which prevents us from using GNU-extensions in
libbpf.c, like reallocarray() or dup3().  Move error printing
code into a separate file to allow it to continue using POSIX
strerror_r().

No functional changes.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:34 +02:00
Jakub Kicinski
07f2d4eac2 tools: libbpf: add extended attributes version of bpf_object__open()
Similarly to bpf_prog_load() users of bpf_object__open() may need
to specify the expected program type.  Program type is needed at
open to avoid the kernel version check for program types which don't
require it.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:34 +02:00
Jakub Kicinski
f83fb22c6c tools: libbpf: recognize offload neutral maps
Add helper to libbpf for recognizing maps which should not have
ifindex set when program is loaded.  These maps only contain
host metadata and therefore are not marked for offload, e.g.
the perf event map.

Use this helper in bpf_prog_load_xattr().

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:34 +02:00
Jakub Kicinski
b60df2a0e1 tools: libbpf: expose the prog type guessing from section name logic
libbpf can guess program type based on ELF section names.  As libbpf
becomes more popular its association between section name strings and
types becomes more of a standard.  Allow libbpf users to use the same
logic for matching strings to types, e.g. when the string originates
from command line.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:33 +02:00
Jakub Kicinski
eac7d84519 tools: libbpf: don't return '.text' as a program for multi-function programs
Make bpf_program__next() skip over '.text' section if object file
has pseudo calls.  The '.text' section is hardly a program in that
case, it's more of a storage for code of functions other than main.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01 01:01:50 +02:00
Jakub Kicinski
9a94f277c4 tools: libbpf: restore the ability to load programs from .text section
libbpf used to be able to load programs from the default section
called '.text'.  It's not very common to leave sections unnamed,
but if it happens libbpf will fail to load the programs reporting
-EINVAL from the kernel.  The -EINVAL comes from bpf_obj_name_cpy()
because since 48cca7e44f ("libbpf: add support for bpf_call")
libbpf does not resolve program names for programs in '.text',
defaulting to '.text'.  '.text', however, does not pass the
(isalnum(*src) || *src == '_') check in bpf_obj_name_cpy().

With few extra lines of code we can limit the pseudo call
assumptions only to objects which actually contain code relocations.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01 01:01:50 +02:00
Jakub Kicinski
9aba36139a tools: libbpf: allow setting ifindex for programs and maps
Users of bpf_object__open()/bpf_object__load() APIs may want to
load the programs and maps onto a device for offload.  Allow
setting ifindex on those sub-objects.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01 01:01:50 +02:00
Jakub Kicinski
d9b683d746 tools: libbpf: add section names for missing program types
Specify default section names for BPF_PROG_TYPE_LIRC_MODE2
and BPF_PROG_TYPE_LWT_SEG6LOCAL, these are the only two
missing right now.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-01 01:01:50 +02:00
Sean Young
6bdd533cee bpf: add selftest for lirc_mode2 type program
This is simple test over rc-loopback.

Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-30 12:40:14 +02:00
Andrey Ignatov
72481f398c libbpf: Support guessing sendmsg{4,6} progs
libbpf can guess prog type and expected attach type based on section
name. Add hints for "cgroup/sendmsg4" and "cgroup/sendmsg6" section
names.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-28 17:41:03 +02:00
Andrey Ignatov
a493f5f9d8 libbpf: Install btf.h with libbpf
install_headers target should contain all headers that are part of
libbpf. Add missing btf.h

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-28 00:25:32 +02:00
David S. Miller
90fed9c946 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2018-05-24

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Björn Töpel cleans up AF_XDP (removes rebind, explicit cache alignment from uapi, etc).

2) David Ahern adds mtu checks to bpf_ipv{4,6}_fib_lookup() helpers.

3) Jesper Dangaard Brouer adds bulking support to ndo_xdp_xmit.

4) Jiong Wang adds support for indirect and arithmetic shifts to NFP

5) Martin KaFai Lau cleans up BTF uapi and makes the btf_header extensible.

6) Mathieu Xhonneux adds an End.BPF action to seg6local with BPF helpers allowing
   to edit/grow/shrink a SRH and apply on a packet generic SRv6 actions.

7) Sandipan Das adds support for bpf2bpf function calls in ppc64 JIT.

8) Yonghong Song adds BPF_TASK_FD_QUERY command for introspection of tracing events.

9) other misc fixes from Gustavo A. R. Silva, Sirio Balmelli, John Fastabend, and Magnus Karlsson
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-24 22:20:51 -04:00
Yonghong Song
30687ad94e tools/bpf: sync kernel header bpf.h and add bpf_task_fd_query in libbpf
Sync kernel header bpf.h to tools/include/uapi/linux/bpf.h and
implement bpf_task_fd_query() in libbpf. The test programs
in samples/bpf and tools/testing/selftests/bpf, and later bpftool
will use this libbpf function to query kernel.

Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-24 18:18:19 -07:00
Mathieu Xhonneux
004d4b274e ipv6: sr: Add seg6local action End.BPF
This patch adds the End.BPF action to the LWT seg6local infrastructure.
This action works like any other seg6local End action, meaning that an IPv6
header with SRH is needed, whose DA has to be equal to the SID of the
action. It will also advance the SRH to the next segment, the BPF program
does not have to take care of this.

Since the BPF program may not be a source of instability in the kernel, it
is important to ensure that the integrity of the packet is maintained
before yielding it back to the IPv6 layer. The hook hence keeps track if
the SRH has been altered through the helpers, and re-validates its
content if needed with seg6_validate_srh. The state kept for validation is
stored in a per-CPU buffer. The BPF program is not allowed to directly
write into the packet, and only some fields of the SRH can be altered
through the helper bpf_lwt_seg6_store_bytes.

Performances profiling has shown that the SRH re-validation does not induce
a significant overhead. If the altered SRH is deemed as invalid, the packet
is dropped.

This validation is also done before executing any action through
bpf_lwt_seg6_action, and will not be performed again if the SRH is not
modified after calling the action.

The BPF program may return 3 types of return codes:
    - BPF_OK: the End.BPF action will look up the next destination through
             seg6_lookup_nexthop.
    - BPF_REDIRECT: if an action has been executed through the
          bpf_lwt_seg6_action helper, the BPF program should return this
          value, as the skb's destination is already set and the default
          lookup should not be performed.
    - BPF_DROP : the packet will be dropped.

Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-24 11:57:36 +02:00
Sirio Balmelli
a1c818109c tools/lib/libbpf.c: fix string format to allow build on arm32
On arm32, 'cd tools/testing/selftests/bpf && make' fails with:

libbpf.c:80:10: error: format ‘%ld’ expects argument of type ‘long int’, but argument 4 has type ‘int64_t {aka long long int}’ [-Werror=format=]
   (func)("libbpf: " fmt, ##__VA_ARGS__); \
          ^
libbpf.c:83:30: note: in expansion of macro ‘__pr’
 #define pr_warning(fmt, ...) __pr(__pr_warning, fmt, ##__VA_ARGS__)
                              ^~~~
libbpf.c:1072:3: note: in expansion of macro ‘pr_warning’
   pr_warning("map:%s value_type:%s has BTF type_size:%ld != value_size:%u\n",

To fix, typecast 'key_size' and amend format string.

Signed-off-by: Sirio Balmelli <sirio@b-ad.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-23 20:18:00 +02:00
Martin KaFai Lau
61746dbe1a bpf: btf: Add tests for the btf uapi changes
This patch does the followings:
1. Modify libbpf and test_btf to reflect the uapi changes in btf
2. Add test for the btf_header changes
3. Add tests for array->index_type
4. Add err_str check to the tests
5. Fix a 4 bytes hole in "struct test #1" by swapping "m" and "n"

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-23 12:03:32 +02:00
David S. Miller
6f6e434aa2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
S390 bpf_jit.S is removed in net-next and had changes in 'net',
since that code isn't used any more take the removal.

TLS data structures split the TX and RX components in 'net-next',
put the new struct members from the bug fix in 'net' into the RX
part.

The 'net-next' tree had some reworking of how the ERSPAN code works in
the GRE tunneling code, overlapping with a one-line headroom
calculation fix in 'net'.

Overlapping changes in __sock_map_ctx_update_elem(), keep the bits
that read the prog members via READ_ONCE() into local variables
before using them.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-21 16:01:54 -04:00
David Beckett
f0307a7ed1 libbpf: add ifindex to enable offload support
BPF programs currently can only be offloaded using iproute2. This
patch will allow programs to be offloaded using libbpf calls.

Signed-off-by: David Beckett <david.beckett@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-17 00:54:26 +02:00
Jakub Kicinski
17387dd5ac tools: bpf: don't complain about no kernel version for networking code
BPF programs only have to specify the target kernel version for
tracing related hooks, in networking world that requirement does
not really apply.  Loosen the checks in libbpf to reflect that.

bpf_object__open() users will continue to see the error for backward
compatibility (and because prog_type is not available there).

Error code for NULL file name is changed from ENOENT to EINVAL,
as it seems more appropriate, hopefully, that's an OK change.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 01:40:52 +02:00
Jakub Kicinski
2eb57bb8f6 tools: bpf: improve comments in libbpf.h
Fix spelling mistakes, improve and clarify the language of comments
in libbpf.h.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 01:40:52 +02:00
Jakub Kicinski
d0cabbb021 tools: bpf: move the event reading loop to libbpf
There are two copies of event reading loop - in bpftool and
trace_helpers "library".  Consolidate them and move the code
to libbpf.  Return codes from trace_helpers are kept, but
renamed to include LIBBPF prefix.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 01:40:52 +02:00
Jakub Kicinski
3597683c9d tools: bpf: handle NULL return in bpf_prog_load_xattr()
bpf_object__open() can return error pointer as well as NULL.
Fix error handling in bpf_prog_load_xattr() (and indirectly
bpf_prog_load()).

Fixes: 6f6d33f3b3 ("bpf: selftests add sockmap tests")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 00:20:53 +02:00
Martin KaFai Lau
cd8b89280c bpf: btf: Tests for BPF_OBJ_GET_INFO_BY_FD and BPF_BTF_GET_FD_BY_ID
This patch adds test for BPF_BTF_GET_FD_BY_ID and the new
btf_id/btf_key_id/btf_value_id in the "struct bpf_map_info".

It also modifies the existing BPF_OBJ_GET_INFO_BY_FD test
to reflect the new "struct bpf_btf_info".

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-09 17:25:14 +02:00
John Fastabend
16962b2404 bpf: sockmap, add selftests
This adds a new test program test_sockmap which is the old sample
sockmap program. By moving the sample program here we can now run it
as part of the self tests suite. To support this a populate_progs()
routine is added to load programs and maps which was previously done
with load_bpf_file(). This is needed because self test libs do not
provide a similar routine. Also we now use the cgroup_helpers
routines to manage cgroup use instead of manually creating one and
supplying it to the CLI.

Notice we keep the CLI around though because it is useful for dbg
and specialized testing.

To run use ./test_sockmap and the result should be,

Summary 660 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-04-25 00:06:20 +02:00
Martin KaFai Lau
fbcf93ebca bpf: btf: Clean up btf.h in uapi
This patch cleans up btf.h in uapi:
1) Rename "name" to "name_off" to better reflect it is an offset to the
   string section instead of a char array.
2) Remove unused value BTF_FLAGS_COMPR and BTF_MAGIC_SWAP

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-04-23 11:32:01 +02:00
Björn Töpel
878a4d3281 libbpf: fixed build error for samples/bpf/
Commit 8a138aed4a ("bpf: btf: Add BTF support to libbpf") did not
include stdbool.h, so GCC complained when building samples/bpf/.

In file included from /home/btopel/src/ext/linux/samples/bpf/libbpf.h:6:0,
                 from /home/btopel/src/ext/linux/samples/bpf/test_lru_dist.c:24:
/home/btopel/src/ext/linux/tools/lib/bpf/bpf.h:105:4: error: unknown type name ‘bool’; did you mean ‘_Bool’?
    bool do_log);
    ^~~~
    _Bool

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-04-20 10:12:19 +02:00
Martin KaFai Lau
8a138aed4a bpf: btf: Add BTF support to libbpf
If the ".BTF" elf section exists, libbpf will try to create
a btf_fd (through BPF_BTF_LOAD).  If that fails, it will still
continue loading the bpf prog/map without the BTF.

If the bpf_object has a BTF loaded, it will create a map with the btf_fd.
libbpf will try to figure out the btf_key_id and btf_value_id of a map by
finding the BTF type with name "<map_name>_key" and "<map_name>_value".
If they cannot be found, it will continue without using the BTF.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-04-19 21:46:25 +02:00
Andrey Ignatov
e14c93fd5b libbpf: Type functions for raw tracepoints
Add missing pieces for BPF_PROG_TYPE_RAW_TRACEPOINT in libbpf:
* is- and set- functions;
* support guessing prog type.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-04-18 14:39:24 +02:00
Andrey Ignatov
81efee75c4 libbpf: Support guessing post_bind{4,6} progs
libbpf can guess prog type and expected attach type based on section
name. Add hints for "cgroup/post_bind4" and "cgroup/post_bind6" section
names.

Existing "cgroup/sock" is not changed, i.e. expected_attach_type for it
is not set to `BPF_CGROUP_INET_SOCK_CREATE`, for backward compatibility.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-04-18 14:39:24 +02:00
Andrey Ignatov
622adafb2a selftests/bpf: Selftest for sys_connect hooks
Add selftest for BPF_CGROUP_INET4_CONNECT and BPF_CGROUP_INET6_CONNECT
attach types.

Try to connect(2) to specified IP:port and test that:
* remote IP:port pair is overridden;
* local end of connection is bound to specified IP.

All combinations of IPv4/IPv6 and TCP/UDP are tested.

Example:
  # tcpdump -pn -i lo -w connect.pcap 2>/dev/null &
  [1] 478
  # strace -qqf -e connect -o connect.trace ./test_sock_addr.sh
  Wait for testing IPv4/IPv6 to become available ... OK
  Load bind4 with invalid type (can pollute stderr) ... REJECTED
  Load bind4 with valid type ... OK
  Attach bind4 with invalid type ... REJECTED
  Attach bind4 with valid type ... OK
  Load connect4 with invalid type (can pollute stderr) libbpf: load bpf \
    program failed: Permission denied
  libbpf: -- BEGIN DUMP LOG ---
  libbpf:
  0: (b7) r2 = 23569
  1: (63) *(u32 *)(r1 +24) = r2
  2: (b7) r2 = 16777343
  3: (63) *(u32 *)(r1 +4) = r2
  invalid bpf_context access off=4 size=4
  [ 1518.404609] random: crng init done

  libbpf: -- END LOG --
  libbpf: failed to load program 'cgroup/connect4'
  libbpf: failed to load object './connect4_prog.o'
  ... REJECTED
  Load connect4 with valid type ... OK
  Attach connect4 with invalid type ... REJECTED
  Attach connect4 with valid type ... OK
  Test case #1 (IPv4/TCP):
          Requested: bind(192.168.1.254, 4040) ..
             Actual: bind(127.0.0.1, 4444)
          Requested: connect(192.168.1.254, 4040) from (*, *) ..
             Actual: connect(127.0.0.1, 4444) from (127.0.0.4, 56068)
  Test case #2 (IPv4/UDP):
          Requested: bind(192.168.1.254, 4040) ..
             Actual: bind(127.0.0.1, 4444)
          Requested: connect(192.168.1.254, 4040) from (*, *) ..
             Actual: connect(127.0.0.1, 4444) from (127.0.0.4, 56447)
  Load bind6 with invalid type (can pollute stderr) ... REJECTED
  Load bind6 with valid type ... OK
  Attach bind6 with invalid type ... REJECTED
  Attach bind6 with valid type ... OK
  Load connect6 with invalid type (can pollute stderr) libbpf: load bpf \
    program failed: Permission denied
  libbpf: -- BEGIN DUMP LOG ---
  libbpf:
  0: (b7) r6 = 0
  1: (63) *(u32 *)(r1 +12) = r6
  invalid bpf_context access off=12 size=4

  libbpf: -- END LOG --
  libbpf: failed to load program 'cgroup/connect6'
  libbpf: failed to load object './connect6_prog.o'
  ... REJECTED
  Load connect6 with valid type ... OK
  Attach connect6 with invalid type ... REJECTED
  Attach connect6 with valid type ... OK
  Test case #3 (IPv6/TCP):
          Requested: bind(face:b00c:1234:5678::abcd, 6060) ..
             Actual: bind(::1, 6666)
          Requested: connect(face:b00c:1234:5678::abcd, 6060) from (*, *)
             Actual: connect(::1, 6666) from (::6, 37458)
  Test case #4 (IPv6/UDP):
          Requested: bind(face:b00c:1234:5678::abcd, 6060) ..
             Actual: bind(::1, 6666)
          Requested: connect(face:b00c:1234:5678::abcd, 6060) from (*, *)
             Actual: connect(::1, 6666) from (::6, 39315)
  ### SUCCESS
  # egrep 'connect\(.*AF_INET' connect.trace | \
  > egrep -vw 'htons\(1025\)' | fold -b -s -w 72
  502   connect(7, {sa_family=AF_INET, sin_port=htons(4040),
  sin_addr=inet_addr("192.168.1.254")}, 128) = 0
  502   connect(8, {sa_family=AF_INET, sin_port=htons(4040),
  sin_addr=inet_addr("192.168.1.254")}, 128) = 0
  502   connect(9, {sa_family=AF_INET6, sin6_port=htons(6060),
  inet_pton(AF_INET6, "face:b00c:1234:5678::abcd", &sin6_addr),
  sin6_flowinfo=0, sin6_scope_id=0}, 128) = 0
  502   connect(10, {sa_family=AF_INET6, sin6_port=htons(6060),
  inet_pton(AF_INET6, "face:b00c:1234:5678::abcd", &sin6_addr),
  sin6_flowinfo=0, sin6_scope_id=0}, 128) = 0
  # fg
  tcpdump -pn -i lo -w connect.pcap 2> /dev/null
  # tcpdump -r connect.pcap -n tcp | cut -c 1-72
  reading from file connect.pcap, link-type EN10MB (Ethernet)
  17:57:40.383533 IP 127.0.0.4.56068 > 127.0.0.1.4444: Flags [S], seq 1333
  17:57:40.383566 IP 127.0.0.1.4444 > 127.0.0.4.56068: Flags [S.], seq 112
  17:57:40.383589 IP 127.0.0.4.56068 > 127.0.0.1.4444: Flags [.], ack 1, w
  17:57:40.384578 IP 127.0.0.1.4444 > 127.0.0.4.56068: Flags [R.], seq 1,
  17:57:40.403327 IP6 ::6.37458 > ::1.6666: Flags [S], seq 406513443, win
  17:57:40.403357 IP6 ::1.6666 > ::6.37458: Flags [S.], seq 2448389240, ac
  17:57:40.403376 IP6 ::6.37458 > ::1.6666: Flags [.], ack 1, win 342, opt
  17:57:40.404263 IP6 ::1.6666 > ::6.37458: Flags [R.], seq 1, ack 1, win

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-31 02:16:14 +02:00
Andrey Ignatov
e50b0a6f08 selftests/bpf: Selftest for sys_bind hooks
Add selftest to work with bpf_sock_addr context from
`BPF_PROG_TYPE_CGROUP_SOCK_ADDR` programs.

Try to bind(2) on IP:port and apply:
* loads to make sure context can be read correctly, including narrow
  loads (byte, half) for IP and full-size loads (word) for all fields;
* stores to those fields allowed by verifier.

All combination from IPv4/IPv6 and TCP/UDP are tested.

Both scenarios are tested:
* valid programs can be loaded and attached;
* invalid programs can be neither loaded nor attached.

Test passes when expected data can be read from context in the
BPF-program, and after the call to bind(2) socket is bound to IP:port
pair that was written by BPF-program to the context.

Example:
  # ./test_sock_addr
  Attached bind4 program.
  Test case #1 (IPv4/TCP):
          Requested: bind(192.168.1.254, 4040) ..
             Actual: bind(127.0.0.1, 4444)
  Test case #2 (IPv4/UDP):
          Requested: bind(192.168.1.254, 4040) ..
             Actual: bind(127.0.0.1, 4444)
  Attached bind6 program.
  Test case #3 (IPv6/TCP):
          Requested: bind(face:b00c:1234:5678::abcd, 6060) ..
             Actual: bind(::1, 6666)
  Test case #4 (IPv6/UDP):
          Requested: bind(face:b00c:1234:5678::abcd, 6060) ..
             Actual: bind(::1, 6666)
  ### SUCCESS

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-31 02:15:30 +02:00
Andrey Ignatov
d7be143b67 libbpf: Support expected_attach_type at prog load
Support setting `expected_attach_type` at prog load time in both
`bpf/bpf.h` and `bpf/libbpf.h`.

Since both headers already have API to load programs, new functions are
added not to break backward compatibility for existing ones:
* `bpf_load_program_xattr()` is added to `bpf/bpf.h`;
* `bpf_prog_load_xattr()` is added to `bpf/libbpf.h`.

Both new functions accept structures, `struct bpf_load_program_attr` and
`struct bpf_prog_load_attr` correspondingly, where new fields can be
added in the future w/o changing the API.

Standard `_xattr` suffix is used to name the new API functions.

Since `bpf_load_program_name()` is not used as heavily as
`bpf_load_program()`, it was removed in favor of more generic
`bpf_load_program_xattr()`.

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-31 02:15:05 +02:00
Alexei Starovoitov
a0fe3e574b libbpf: add bpf_raw_tracepoint_open helper
add bpf_raw_tracepoint_open(const char *name, int prog_fd) api to libbpf

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-28 22:55:19 +02:00
John Fastabend
4c4c3c276c bpf: sockmap sample, add option to attach SK_MSG program
Add sockmap option to use SK_MSG program types.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-19 21:14:40 +01:00
Jeremy Cline
b1a2ce8257 tools/libbpf: Avoid possibly using uninitialized variable
Fixes a GCC maybe-uninitialized warning introduced by 48cca7e44f.
"text" is only initialized inside the if statement so only print debug
info there.

Fixes: 48cca7e44f ("libbpf: add support for bpf_call")
Signed-off-by: Jeremy Cline <jeremy@jcline.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-20 21:08:20 +01:00
Jesper Dangaard Brouer
e3d91b0ca5 tools/libbpf: handle issues with bpf ELF objects containing .eh_frames
V3: More generic skipping of relo-section (suggested by Daniel)

If clang >= 4.0.1 is missing the option '-target bpf', it will cause
llc/llvm to create two ELF sections for "Exception Frames", with
section names '.eh_frame' and '.rel.eh_frame'.

The BPF ELF loader library libbpf fails when loading files with these
sections.  The other in-kernel BPF ELF loader in samples/bpf/bpf_load.c,
handle this gracefully. And iproute2 loader also seems to work with these
"eh" sections.

The issue in libbpf is caused by bpf_object__elf_collect() skipping
some sections, and later when performing relocation it will be
pointing to a skipped section, as these sections cannot be found by
bpf_object__find_prog_by_idx() in bpf_object__collect_reloc().

This is a general issue that also occurs for other sections, like
debug sections which are also skipped and can have relo section.

As suggested by Daniel.  To avoid keeping state about all skipped
sections, instead perform a direct qlookup in the ELF object.  Lookup
the section that the relo-section points to and check if it contains
executable machine instructions (denoted by the sh_flags
SHF_EXECINSTR).  Use this check to also skip irrelevant relo-sections.

Note, for samples/bpf/ the '-target bpf' parameter to clang cannot be used
due to incompatibility with asm embedded headers, that some of the samples
include. This is explained in more details by Yonghong Song in bpf_devel_QA.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-09 00:25:12 +01:00