When the error code is EAGAIN, the kernel signals the user
space should retry the read() operation for bpf iterators.
Let us do it.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200818222312.2181675-1-yhs@fb.com
The comment in the code describes this in good details. Generate such a memory
layout that would work both on 32-bit and 64-bit architectures for user-space.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200813204945.1020225-9-andriin@fb.com
Fix few compilation warnings in bpftool when compiling in 32-bit mode.
Abstract away u64 to pointer conversion into a helper function.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200813204945.1020225-2-andriin@fb.com
Seems like C++17 standard mode doesn't recognize typeof() anymore. This can
be tested by compiling test_cpp test with -std=c++17 or -std=c++1z options.
The use of typeof in skeleton generated code is unnecessary, all types are
well-known at the time of code generation, so remove all typeof()'s to make
skeleton code more future-proof when interacting with C++ compilers.
Fixes: 985ead416d ("bpftool: Add skeleton codegen command")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200812025907.1371956-1-andriin@fb.com
Previous commit adjusted kernel uapi for map
element bpf iterator. This patch adjusted libbpf API
due to uapi change. bpftool and bpf_iter selftests
are also changed accordingly.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200805055058.1457623-1-yhs@fb.com
Use generic libbpf API to parse BTF data from file, instead of re-implementing
it in bpftool.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200802013219.864880-3-andriin@fb.com
In case of btf_id does not exist, a negative error code -ENOENT
should be returned.
Fixes: c93cc69004 ("bpftool: add ability to dump BTF types")
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200802111540.5384-1-tianjia.zhang@linux.alibaba.com
Add info on link detach sub-command to man page. Add detach to bash-completion
as well.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com.
Link: https://lore.kernel.org/bpf/20200731182830.286260-6-andriin@fb.com
Add ability to force-detach BPF link. Also add missing error message, if
specified link ID is wrong.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200731182830.286260-5-andriin@fb.com
Assign "lsm" as a printed name for BPF_PROG_TYPE_LSM in bpftool, so that
it can use it when listing programs loaded on the system or when probing
features.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200724090618.16378-3-quentin@isovalent.com
For probing program and map types, bpftool loops on type values and uses
the relevant type name in prog_type_name[] or map_type_name[]. To ensure
the name exists, we exit from the loop if we go over the size of the
array.
However, this is not enough in the case where the arrays have "holes" in
them, program or map types for which they have no name, but not at the
end of the list. This is currently the case for BPF_PROG_TYPE_LSM, not
known to bpftool and which name is a null string. When probing for
features, bpftool attempts to strlen() that name and segfaults.
Let's fix it by skipping probes for "unknown" program and map types,
with an informational message giving the numeral value in that case.
Fixes: 93a3545d81 ("tools/bpftool: Add name mappings for SK_LOOKUP prog and attach type")
Reported-by: Paul Chaignon <paul@cilium.io>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200724090618.16378-2-quentin@isovalent.com
The optional parameter "map MAP" can be added to "bpftool iter"
command to create a bpf iterator for map elements. For example,
bpftool iter pin ./prog.o /sys/fs/bpf/p1 map id 333
For map element bpf iterator "map MAP" parameter is required.
Otherwise, bpf link creation will return an error.
Quentin Monnet kindly provided bash-completion implementation
for new "map MAP" option.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200723184119.590799-1-yhs@fb.com
The bpftool sources include code to walk file trees, but use multiple
frameworks to do so: nftw and fts. While nftw conforms to POSIX/SUSv3 and
is widely available, fts is not conformant and less common, especially on
non-glibc systems. The inconsistent framework usage hampers maintenance
and portability of bpftool, in particular for embedded systems.
Standardize code usage by rewriting one fts-based function to use nftw and
clean up some related function warnings by extending use of "const char *"
arguments. This change helps in building bpftool against musl for OpenWrt.
Also fix an unsafe call to dirname() by duplicating the string to pass,
since some implementations may directly alter it. The same approach is
used in libbpf.c.
Signed-off-by: Tony Ambardar <Tony.Ambardar@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200721024817.13701-1-Tony.Ambardar@gmail.com
A handful of samples and selftests fail to build on s390, because
after commit 0ebeea8ca8 ("bpf: Restrict bpf_probe_read{, str}()
only to archs where they work") bpf_probe_read is not available
anymore.
Fix by using bpf_probe_read_kernel.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200720114806.88823-1-iii@linux.ibm.com
Make bpftool show human-friendly identifiers for newly introduced program
and attach type, BPF_PROG_TYPE_SK_LOOKUP and BPF_SK_LOOKUP, respectively.
Also, add the new prog type bash-completion, man page and help message.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200717103536.397595-14-jakub@cloudflare.com
Reliably remove all the type modifiers from read-only (.rodata) global
variable definitions, including cases of inner field const modifiers and
arrays of const values.
Also modify one of selftests to ensure that const volatile struct doesn't
prevent user-space from modifying .rodata variable.
Fixes: 985ead416d ("bpftool: Add skeleton codegen command")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200713232409.3062144-3-andriin@fb.com
Don't emit warning that bpftool was built without PID iterator support. This
error garbles JSON output of otherwise perfectly valid show commands.
Reported-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200710232605.20918-1-andriin@fb.com
emit_obj_refs_json needs to added the same as with emit_obj_refs_plain
to prevent segfaults, similar to Commit "8ae4121bd89e bpf: Fix bpftool
without skeleton code enabled"). See the error below:
# ./bpftool -p prog
{
"error": "bpftool built without PID iterator support"
},[{
"id": 2,
"type": "cgroup_skb",
"tag": "7be49e3934a125ba",
"gpl_compatible": true,
"loaded_at": 1594052789,
"uid": 0,
"bytes_xlated": 296,
"jited": true,
"bytes_jited": 203,
"bytes_memlock": 4096,
"map_ids": [2,3
Segmentation fault (core dumped)
The same happens for ./bpftool -p map, as well as ./bpftool -j prog/map.
Fixes: d53dee3fe0 ("tools/bpftool: Show info for processes holding BPF map/prog/link/btf FDs")
Signed-off-by: Louis Peens <louis.peens@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200708110827.7673-1-louis.peens@netronome.com
Support attaching to BPF_CGROUP_INET_SOCK_RELEASE and properly
display attach type upon prog dump.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200706230128.4073544-4-sdf@google.com
Daniel Borkmann says:
====================
pull-request: bpf-next 2020-07-04
The following pull-request contains BPF updates for your *net-next* tree.
We've added 73 non-merge commits during the last 17 day(s) which contain
a total of 106 files changed, 5233 insertions(+), 1283 deletions(-).
The main changes are:
1) bpftool ability to show PIDs of processes having open file descriptors
for BPF map/program/link/BTF objects, relying on BPF iterator progs
to extract this info efficiently, from Andrii Nakryiko.
2) Addition of BPF iterator progs for dumping TCP and UDP sockets to
seq_files, from Yonghong Song.
3) Support access to BPF map fields in struct bpf_map from programs
through BTF struct access, from Andrey Ignatov.
4) Add a bpf_get_task_stack() helper to be able to dump /proc/*/stack
via seq_file from BPF iterator progs, from Song Liu.
5) Make SO_KEEPALIVE and related options available to bpf_setsockopt()
helper, from Dmitry Yakunin.
6) Optimize BPF sk_storage selection of its caching index, from Martin
KaFai Lau.
7) Removal of redundant synchronize_rcu()s from BPF map destruction which
has been a historic leftover, from Alexei Starovoitov.
8) Several improvements to test_progs to make it easier to create a shell
loop that invokes each test individually which is useful for some CIs,
from Jesper Dangaard Brouer.
9) Fix bpftool prog dump segfault when compiled without skeleton code on
older clang versions, from John Fastabend.
10) Bunch of cleanups and minor improvements, from various others.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix segfault from bpftool by adding emit_obj_refs_plain when skeleton
code is disabled.
Tested by deleting BUILD_BPF_SKELS in Makefile. We found this doing
backports for Cilium when a testing image pulled in latest bpf-next
bpftool, but kept using an older clang-7.
# ./bpftool prog show
Error: bpftool built without PID iterator support
3: cgroup_skb tag 7be49e3934a125ba gpl
loaded_at 2020-07-01T08:01:29-0700 uid 0
Segmentation fault
Fixes: d53dee3fe0 ("tools/bpftool: Show info for processes holding BPF map/prog/link/btf FDs")
Reported-by: Joe Stringer <joe@wand.net.nz>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/159375071997.14984.17404504293832961401.stgit@john-XPS-13-9370
Turn off -Wnested-externs to avoid annoying warnings in BUILD_BUG_ON macro when
compiling bpftool:
In file included from /data/users/andriin/linux/tools/include/linux/build_bug.h:5,
from /data/users/andriin/linux/tools/include/linux/kernel.h:8,
from /data/users/andriin/linux/kernel/bpf/disasm.h:10,
from /data/users/andriin/linux/kernel/bpf/disasm.c:8:
/data/users/andriin/linux/kernel/bpf/disasm.c: In function ‘__func_get_name’:
/data/users/andriin/linux/tools/include/linux/compiler.h:37:38: warning: nested extern declaration of ‘__compiletime_assert_0’ [-Wnested-externs]
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^~~~~~~~~~~~~~~~~~~~~
/data/users/andriin/linux/tools/include/linux/compiler.h:16:15: note: in definition of macro ‘__compiletime_assert’
extern void prefix ## suffix(void) __compiletime_error(msg); \
^~~~~~
/data/users/andriin/linux/tools/include/linux/compiler.h:37:2: note: in expansion of macro ‘_compiletime_assert’
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^~~~~~~~~~~~~~~~~~~
/data/users/andriin/linux/tools/include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^~~~~~~~~~~~~~~~~~
/data/users/andriin/linux/tools/include/linux/build_bug.h:50:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
^~~~~~~~~~~~~~~~
/data/users/andriin/linux/kernel/bpf/disasm.c:20:2: note: in expansion of macro ‘BUILD_BUG_ON’
BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID);
^~~~~~~~~~~~
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200701212816.2072340-1-andriin@fb.com
In some build contexts (e.g., Travis CI build for outdated kernel), vmlinux.h,
generated from available kernel, doesn't contain all the types necessary for
BPF program compilation. For such set up, the most maintainable way to deal
with this problem is to keep pre-generated (almost up-to-date) vmlinux.h
checked in and use it for compilation purposes. bpftool after that can deal
with kernel missing some of the features in runtime with no problems.
To that effect, allow to specify path to custom vmlinux.h to bpftool's
Makefile with VMLINUX_H variable.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200630004759.521530-1-andriin@fb.com
Define attach_type_name in common.c instead of main.h so it is only
defined once. This leads to a slight decrease in the binary size of
bpftool.
Before:
text data bss dec hex filename
399024 11168 1573160 1983352 1e4378 bpftool
After:
text data bss dec hex filename
398256 10880 1573160 1982296 1e3f58 bpftool
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200624143154.13145-1-tklauser@distanz.ch
Define prog_type_name in prog.c instead of main.h so it is only defined
once. This leads to a slight decrease in the binary size of bpftool.
Before:
text data bss dec hex filename
401032 11936 1573160 1986128 1e4e50 bpftool
After:
text data bss dec hex filename
399024 11168 1573160 1983352 1e4378 bpftool
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200624143124.12914-1-tklauser@distanz.ch
Building bpftool yields the following complaint:
pids.c: In function 'emit_obj_refs_json':
pids.c:175:80: warning: declaration of 'json_wtr' shadows a global declaration [-Wshadow]
175 | void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, json_writer_t *json_wtr)
| ~~~~~~~~~~~~~~~^~~~~~~~
In file included from pids.c:11:
main.h:141:23: note: shadowed declaration is here
141 | extern json_writer_t *json_wtr;
| ^~~~~~~~
Let's rename the variable.
v2:
- Rename the variable instead of calling the global json_wtr directly.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200623213600.16643-1-quentin@isovalent.com
Currently, if the clang-bpf-co-re feature is not available, the build
fails with e.g.
CC prog.o
prog.c:1462:10: fatal error: profiler.skel.h: No such file or directory
1462 | #include "profiler.skel.h"
| ^~~~~~~~~~~~~~~~~
This is due to the fact that the BPFTOOL_WITHOUT_SKELETONS macro is not
defined, despite BUILD_BPF_SKELS not being set. Fix this by correctly
evaluating $(BUILD_BPF_SKELS) when deciding on whether to add
-DBPFTOOL_WITHOUT_SKELETONS to CFLAGS.
Fixes: 05aca6da3b ("tools/bpftool: Generalize BPF skeleton support and generate vmlinux.h")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200623103710.10370-1-tklauser@distanz.ch
Add statements about bpftool being able to discover process info, holding
reference to BPF map, prog, link, or BTF. Show example output as well.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200619231703.738941-10-andriin@fb.com
Adapt Makefile to support BPF skeleton generation beyond single profiler.bpf.c
case. Also add vmlinux.h generation and switch profiler.bpf.c to use it.
clang-bpf-global-var feature is extended and renamed to clang-bpf-co-re to
check for support of preserve_access_index attribute, which, together with BTF
for global variables, is the minimum requirement for modern BPF programs.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200619231703.738941-7-andriin@fb.com
Build minimal "bootstrap mode" bpftool to enable skeleton (and, later,
vmlinux.h generation), instead of building almost complete, but slightly
different (w/o skeletons, etc) bpftool to bootstrap complete bpftool build.
Current approach doesn't scale well (engineering-wise) when adding more BPF
programs to bpftool and other complicated functionality, as it requires
constant adjusting of the code to work in both bootstrapped mode and normal
mode.
So it's better to build only minimal bpftool version that supports only BPF
skeleton code generation and BTF-to-C conversion. Thankfully, this is quite
easy to accomplish due to internal modularity of bpftool commands. This will
also allow to keep adding new functionality to bpftool in general, without the
need to care about bootstrap mode for those new parts of bpftool.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200619231703.738941-6-andriin@fb.com
Move functions that parse map and prog by id/tag/name/etc outside of
map.c/prog.c, respectively. These functions are used outside of those files
and are generic enough to be in common. This also makes heavy-weight map.c and
prog.c more decoupled from the rest of bpftool files and facilitates more
lightweight bootstrap bpftool variant.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20200619231703.738941-5-andriin@fb.com
Relicense it to be compatible with the rest of bpftool files.
Suggested-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200619222024.519774-1-andriin@fb.com
Commit c34a06c56d ("tools/bpftool: Add ringbuf map to a list of known
map types") added the symbolic "ringbuf" name. Document it in the bpftool
map command docs and usage as well.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200616113303.8123-1-tklauser@distanz.ch
Add symbolic name "ringbuf" to map to BPF_MAP_TYPE_RINGBUF. Without this,
users will see "type 27" instead of "ringbuf" in `map show` output.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200615225355.366256-1-andriin@fb.com
Remove unnecessary check at the end of codegen() routine which makes codegen()
to always fail and exit bpftool with error code. Positive value of variable
n is not an indicator of a failure.
Fixes: 2c4779eff8 ("tools, bpftool: Exit on error in function codegen")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Tobias Klauser <tklauser@distanz.ch>
Link: https://lore.kernel.org/bpf/20200612201603.680852-1-andriin@fb.com
Currently, the codegen function might fail and return an error. But its
callers continue without checking its return value. Since codegen can
fail only in the unlikely case of the system running out of memory or
the static template being malformed, just exit(-1) directly from codegen
and make it void-returning.
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200611103341.21532-1-tklauser@distanz.ch
Free the memory allocated for the template on error paths in function
codegen.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200610130804.21423-1-tklauser@distanz.ch
When using make kselftest TARGETS=bpf, tools/bpf is built with
MAKEFLAGS=rR, which causes $(COMPILE.c) to be undefined, which in turn
causes the build to fail with
CC kselftest/bpf/tools/build/bpftool/map_perf_ring.o
/bin/sh: 1: -MMD: not found
Fix by using $(CC) $(CFLAGS) -c instead of $(COMPILE.c).
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200602175649.2501580-2-iii@linux.ibm.com
Code for printing link attach_type is duplicated in a couple of places, and
likely will be duplicated for future link types as well. Create helpers to
prevent duplication.
Suggested-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200531082846.2117903-8-jakub@cloudflare.com
btf__parse_raw and btf__parse_elf return negative error numbers wrapped
in an ERR_PTR, so the extracted value needs to be negated before passing
them to strerror which expects a positive error number.
Before:
Error: failed to load BTF from .../vmlinux: Unknown error -2
After:
Error: failed to load BTF from .../vmlinux: No such file or directory
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200525135421.4154-1-tklauser@distanz.ch
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Following the introduction of CAP_BPF, and the switch from CAP_SYS_ADMIN
to other capabilities for various BPF features, update the capability
checks (and potentially, drops) in bpftool for feature probes. Because
bpftool and/or the system might not know of CAP_BPF yet, some caution is
necessary:
- If compiled and run on a system with CAP_BPF, check CAP_BPF,
CAP_SYS_ADMIN, CAP_PERFMON, CAP_NET_ADMIN.
- Guard against CAP_BPF being undefined, to allow compiling bpftool from
latest sources on older systems. If the system where feature probes
are run does not know of CAP_BPF, stop checking after CAP_SYS_ADMIN,
as this should be the only capability required for all the BPF
probing.
- If compiled from latest sources on a system without CAP_BPF, but later
executed on a newer system with CAP_BPF knowledge, then we only test
CAP_SYS_ADMIN. Some probes may fail if the bpftool process has
CAP_SYS_ADMIN but misses the other capabilities. The alternative would
be to redefine the value for CAP_BPF in bpftool, but this does not
look clean, and the case sounds relatively rare anyway.
Note that libcap offers a cap_to_name() function to retrieve the name of
a given capability (e.g. "cap_sys_admin"). We do not use it because
deriving the names from the macros looks simpler than using
cap_to_name() (doing a strdup() on the string) + cap_free() + handling
the case of failed allocations, when we just want to use the name of the
capability in an error message.
The checks when compiling without libcap (i.e. root versus non-root) are
unchanged.
v2:
- Do not allocate cap_list dynamically.
- Drop BPF-related capabilities when running with "unprivileged", even
if we didn't have the full set in the first place (in v1, we would
skip dropping them in that case).
- Keep track of what capabilities we have, print the names of the
missing ones for privileged probing.
- Attempt to drop only the capabilities we actually have.
- Rename a couple variables.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200523010247.20654-1-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This is a clean-up for the formatting of the do_help functions for
bpftool's subcommands. The following fixes are included:
- Do not use argv[-2] for "iter" help message, as the help is shown by
default if no "iter" action is selected, resulting in messages looking
like "./bpftool bpftool pin...".
- Do not print unused HELP_SPEC_PROGRAM in help message for "bpftool
link".
- Andrii used argument indexing to avoid having multiple occurrences of
bin_name and argv[-2] in the fprintf() for the help message, for
"bpftool gen" and "bpftool link". Let's reuse this for all other help
functions. We can remove up to thirty arguments for the "bpftool map"
help message.
- Harmonise all functions, e.g. use ending quotes-comma on a separate
line.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200523010751.23465-1-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Make bpftool aware and add the new get{peer,sock}name attach types to its
cli, documentation and bash completion to allow attachment/detachment of
sock_addr programs there.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Link: https://lore.kernel.org/bpf/9765b3d03e4c29210c4df56a9cc7e52f5f7bb5ef.1589841594.git.daniel@iogearbox.net
In Cilium we've recently switched to make use of bpf_jiffies64() for
parts of our tc and XDP datapath since bpf_ktime_get_ns() is more
expensive and high-precision is not needed for our timeouts we have
anyway. Our agent has a probe manager which picks up the json of
bpftool's feature probe and we also use the macro output in our C
programs e.g. to have workarounds when helpers are not available on
older kernels.
Extend the kernel config info dump to also include the kernel's
CONFIG_HZ, and rework the probe_kernel_image_config() for allowing a
macro dump such that CONFIG_HZ can be propagated to BPF C code as a
simple define if available via config. Latter allows to have _compile-
time_ resolution of jiffies <-> sec conversion in our code since all
are propagated as known constants.
Given we cannot generally assume availability of kconfig everywhere,
we also have a kernel hz probe [0] as a fallback. Potentially, bpftool
could have an integrated probe fallback as well, although to derive it,
we might need to place it under 'bpftool feature probe full' or similar
given it would slow down the probing process overall. Yet 'full' doesn't
fit either for us since we don't want to pollute the kernel log with
warning messages from bpf_probe_write_user() and bpf_trace_printk() on
agent startup; I've left it out for the time being.
[0] https://github.com/cilium/cilium/blob/master/bpf/cilium-probe-kernel-hz.c
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200513075849.20868-1-daniel@iogearbox.net
Bring minor improvements to bpftool documentation. Fix or harmonise
formatting, update map types (including in interactive help), improve
description for "map create", fix a build warning due to a missing line
after the double-colon for the "bpftool prog profile" example,
complete/harmonise/sort the list of related bpftool man pages in
footers.
v2:
- Remove (instead of changing) mark-up on "value" in bpftool-map.rst,
when it does not refer to something passed on the command line.
- Fix an additional typo ("hexadeximal") in the same file.
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200511161536.29853-3-quentin@isovalent.com
Yonghong Song
Andrii Nakryiko
Tianjia Zhang
Quentin Monnet
Tony Ambardar
Ilya Leoshkevich
YueHaibing
Jakub Sitnicki
Louis Peens
Stanislav Fomichev
David S. Miller
John Fastabend
Tobias Klauser
Alexei Starovoitov
Daniel Borkmann