libbpf has three levels of priority for output messages: warn, info,
debug. By default, debug output is not printed to the console.
Add a new "--debug" (short name: "-d") option to bpftool to print libbpf
logs for all three levels.
Internally, we simply use the function provided by libbpf to replace the
default printing function by one that prints logs regardless of their
level.
v2:
- Remove the possibility to select the log-levels to use (v1 offered a
combination of "warn", "info" and "debug").
- Rename option and offer a short name: -d|--debug.
- Add option description to all bpftool manual pages (instead of
bpftool-prog.rst only), as all commands use libbpf.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Document usage and sample output format for `btf dump` sub-command.
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Manual pages would tell that option "-v" (lower case) would print the
version number for bpftool. This is wrong: the short name of the option
is "-V" (upper case). Fix the documentation accordingly.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
bpftool gained support for probing the current system in order to see
what program and map types, and what helpers are available on that
system. This patch adds the possibility to pass an interface index to
libbpf (and hence to the kernel) when trying to load the programs or to
create the maps, in order to see what items a given network device can
support.
A new keyword "dev <ifname>" can be used as an alternative to "kernel"
to indicate that the given device should be tested. If no target ("dev"
or "kernel") is specified bpftool defaults to probing the kernel.
Sample output:
# bpftool -p feature probe dev lo
{
"syscall_config": {
"have_bpf_syscall": true
},
"program_types": {
"have_sched_cls_prog_type": false,
"have_xdp_prog_type": false
},
...
}
As the target is a network device, /proc/ parameters and kernel
configuration are NOT dumped. Availability of the bpf() syscall is
still probed, so we can return early if that syscall is not usable
(since there is no point in attempting the remaining probes in this
case).
Among the program types, only the ones that can be offloaded are probed.
All map types are probed, as there is no specific rule telling which one
could or could not be supported by a device in the future. All helpers
are probed (but only for offload-able program types).
Caveat: as bpftool does not attempt to attach programs to the device at
the moment, probes do not entirely reflect what the device accepts:
typically, for Netronome's nfp, results will announce that TC cls
offload is available even if support has been deactivated (with e.g.
ethtool -K eth1 hw-tc-offload off).
v2:
- All helpers are probed, whereas previous version would only probe the
ones compatible with an offload-able program type. This is because we
do not keep a default compatible program type for each helper anymore.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Make bpftool able to dump a subset of the parameters collected by
probing the system as a listing of C-style #define macros, so that
external projects can reuse the result of this probing and build
BPF-based project in accordance with the features available on the
system.
The new "macros" keyword is used to select this output. An additional
"prefix" keyword is added so that users can select a custom prefix for
macro names, in order to avoid any namespace conflict.
Sample output:
# bpftool feature probe kernel macros prefix FOO_
/*** System call availability ***/
#define FOO_HAVE_BPF_SYSCALL
/*** eBPF program types ***/
#define FOO_HAVE_SOCKET_FILTER_PROG_TYPE
#define FOO_HAVE_KPROBE_PROG_TYPE
#define FOO_HAVE_SCHED_CLS_PROG_TYPE
...
/*** eBPF map types ***/
#define FOO_HAVE_HASH_MAP_TYPE
#define FOO_HAVE_ARRAY_MAP_TYPE
#define FOO_HAVE_PROG_ARRAY_MAP_TYPE
...
/*** eBPF helper functions ***/
/*
* Use FOO_HAVE_PROG_TYPE_HELPER(prog_type_name, helper_name)
* to determine if <helper_name> is available for <prog_type_name>,
* e.g.
* #if FOO_HAVE_PROG_TYPE_HELPER(xdp, bpf_redirect)
* // do stuff with this helper
* #elif
* // use a workaround
* #endif
*/
#define FOO_HAVE_PROG_TYPE_HELPER(prog_type, helper) \
FOO_BPF__PROG_TYPE_ ## prog_type ## __HELPER_ ## helper
...
#define FOO_BPF__PROG_TYPE_socket_filter__HELPER_bpf_probe_read 0
#define FOO_BPF__PROG_TYPE_socket_filter__HELPER_bpf_ktime_get_ns 1
#define FOO_BPF__PROG_TYPE_socket_filter__HELPER_bpf_trace_printk 1
...
v3:
- Change output for helpers again: add a
HAVE_PROG_TYPE_HELPER(type, helper) macro that can be used to tell
if <helper> is available for program <type>.
v2:
- #define-based output added as a distinct patch.
- "HAVE_" prefix appended to macro names.
- Output limited to bpf() syscall availability, BPF prog and map types,
helper functions. In this version kernel config options, procfs
parameter or kernel version are intentionally left aside.
- Following the change on helper probes, format for helper probes in
this output style has changed (now a list of compatible program
types).
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Similarly to what was done for program types and map types, add a set of
probes to test the availability of the different eBPF helper functions
on the current system.
For each known program type, all known helpers are tested, in order to
establish a compatibility matrix. Output is provided as a set of lists
of available helpers, one per program type.
Sample output:
# bpftool feature probe kernel
...
Scanning eBPF helper functions...
eBPF helpers supported for program type socket_filter:
- bpf_map_lookup_elem
- bpf_map_update_elem
- bpf_map_delete_elem
...
eBPF helpers supported for program type kprobe:
- bpf_map_lookup_elem
- bpf_map_update_elem
- bpf_map_delete_elem
...
# bpftool --json --pretty feature probe kernel
{
...
"helpers": {
"socket_filter_available_helpers": ["bpf_map_lookup_elem", \
"bpf_map_update_elem","bpf_map_delete_elem", ...
],
"kprobe_available_helpers": ["bpf_map_lookup_elem", \
"bpf_map_update_elem","bpf_map_delete_elem", ...
],
...
}
}
v5:
- In libbpf.map, move global symbol to the new LIBBPF_0.0.2 section.
v4:
- Use "enum bpf_func_id" instead of "__u32" in bpf_probe_helper()
declaration for the type of the argument used to pass the id of
the helper to probe.
- Undef BPF_HELPER_MAKE_ENTRY after using it.
v3:
- Do not pass kernel version from bpftool to libbpf probes (kernel
version for testing program with kprobes is retrieved directly from
libbpf).
- Dump one list of available helpers per program type (instead of one
list of compatible program types per helper).
v2:
- Move probes from bpftool to libbpf.
- Test all program types for each helper, print a list of working prog
types for each helper.
- Fall back on include/uapi/linux/bpf.h for names and ids of helpers.
- Remove C-style macros output from this patch.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a new component and command for bpftool, in order to probe the
system to dump a set of eBPF-related parameters so that users can know
what features are available on the system.
Parameters are dumped in plain or JSON output (with -j/-p options).
The current patch introduces probing of one simple parameter:
availability of the bpf() system call. Later commits
will add other probes.
Sample output:
# bpftool feature probe kernel
Scanning system call availability...
bpf() syscall is available
# bpftool --json --pretty feature probe kernel
{
"syscall_config": {
"have_bpf_syscall": true
}
}
The optional "kernel" keyword enforces probing of the current system,
which is the only possible behaviour at this stage. It can be safely
omitted.
The feature comes with the relevant man page, but bash completion will
come in a dedicated commit.
v3:
- Do not probe kernel version. Contrarily to what is written below for
v2, we can have the kernel version retrieved in libbpf instead of
bpftool (in the patch adding probing for program types).
v2:
- Remove C-style macros output from this patch.
- Even though kernel version is no longer needed for testing kprobes
availability, note that we still collect it in this patch so that
bpftool gets able to probe (in next patches) older kernels as well.
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
