Commit b12d6ec097 ("bpf: btf: add btf print functionality")
added btf pretty print functionality to bpftool.
There is a problem though in printing a bitfield whose type
has modifiers.
For example, for a type like
typedef int ___int;
struct tmp_t {
int a:3;
___int b:3;
};
Suppose we have a map
struct bpf_map_def SEC("maps") tmpmap = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(__u32),
.value_size = sizeof(struct tmp_t),
.max_entries = 1,
};
and the hash table is populated with one element with
key 0 and value (.a = 1 and .b = 2).
In BTF, the struct member "b" will have a type "typedef" which
points to an int type. The current implementation does not
pass the bit offset during transition from typedef to int type,
hence incorrectly print the value as
$ bpftool m d id 79
[{
"key": 0,
"value": {
"a": 0x1,
"b": 0x1
}
}
]
This patch fixed the issue by carrying bit_offset along the type
chain during bit_field print. The correct result can be printed as
$ bpftool m d id 76
[{
"key": 0,
"value": {
"a": 0x1,
"b": 0x2
}
}
]
The kernel pretty print is implemented correctly and does not
have this issue.
Fixes: b12d6ec097 ("bpf: btf: add btf print functionality")
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch fixes a possible null pointer dereference in
do_load, detected by the semantic patch deref_null.cocci,
with the following warning:
./tools/bpf/bpftool/prog.c:1021:23-25: ERROR: map_replace is NULL but dereferenced.
The following code has potential null pointer references:
881 map_replace = reallocarray(map_replace, old_map_fds + 1,
882 sizeof(*map_replace));
883 if (!map_replace) {
884 p_err("mem alloc failed");
885 goto err_free_reuse_maps;
886 }
...
1019 err_free_reuse_maps:
1020 for (i = 0; i < old_map_fds; i++)
1021 close(map_replace[i].fd);
1022 free(map_replace);
Fixes: 3ff5a4dc5d ("tools: bpftool: allow reuse of maps with bpftool prog load")
Co-developed-by: Wen Yang <wen.yang99@zte.com.cn>
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Update references to other bpftool man pages at the bottom of each
manual page. Also reference the "bpf(2)" and "bpf-helpers(7)" man pages.
References are sorted by number of man section, then by
"prog-and-map-go-first", the other pages in alphabetical order.
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>
Function open_obj_pinned() prints error messages when it fails to open a
link in the BPF virtual file system. However, in some occasions it is
not desirable to print an error, for example when we parse all links
under the bpffs root, and the error is due to some paths actually being
symbolic links.
Example output:
# ls -l /sys/fs/bpf/
lrwxrwxrwx 1 root root 0 Oct 18 19:00 ip -> /sys/fs/bpf/tc/
drwx------ 3 root root 0 Oct 18 19:00 tc
lrwxrwxrwx 1 root root 0 Oct 18 19:00 xdp -> /sys/fs/bpf/tc/
# bpftool --bpffs prog show
Error: bpf obj get (/sys/fs/bpf): Permission denied
Error: bpf obj get (/sys/fs/bpf): Permission denied
# strace -e bpf bpftool --bpffs prog show
bpf(BPF_OBJ_GET, {pathname="/sys/fs/bpf/ip", bpf_fd=0}, 72) = -1 EACCES (Permission denied)
Error: bpf obj get (/sys/fs/bpf): Permission denied
bpf(BPF_OBJ_GET, {pathname="/sys/fs/bpf/xdp", bpf_fd=0}, 72) = -1 EACCES (Permission denied)
Error: bpf obj get (/sys/fs/bpf): Permission denied
...
To fix it, pass a bool as a second argument to the function, and prevent
it from printing an error when the argument is set to true.
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>
Edit the documentation of the -f|--bpffs option to make it explicit that
it dumps paths of pinned programs when bpftool is used to list the
programs only, so that users do not believe they will see the name of
the newly pinned program with "bpftool prog pin" or "bpftool prog load".
Also fix the plain output: do not add a blank line after each program
block, in order to remain consistent with what bpftool does when the
option is not passed.
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>
Function getline() returns -1 on failure to read a line, thus creating
an infinite loop in get_fdinfo() if the key is not found. Fix it by
calling the function only as long as we get a strictly positive return
value.
Found by copying the code for a key which is not always present...
Fixes: 71bb428fe2 ("tools: bpf: add bpftool")
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>
When trying to complete "bpftool map update" commands, the call to
printf would print an error message that would show on the command line
if no map is found to complete the command line.
Fix it by making sure we have map ids to complete the line with, before
we try to print something.
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>
When batch mode is used and all commands succeeds, bpftool prints the
number of commands processed to stderr. There is no particular reason to
use stderr for this, we could as well use stdout. It would avoid getting
unnecessary output on stderr if the standard ouptut is redirected, for
example.
Reported-by: David Beckett <david.beckett@netronome.com>
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>
Names used to pin eBPF programs and maps under the eBPF virtual file
system cannot contain a dot character, which is reserved for future
extensions of this file system.
Document this in bpftool man pages to avoid users getting confused if
pinning fails because of a dot.
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>
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>
The nfp driver is currently always JITing the BPF for 4 context/thread
mode of the NFP flow processors. Tell this to the disassembler,
otherwise some registers may be incorrectly decoded.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Add a way of creating maps from user space. The command takes
as parameters most of the attributes of the map creation system
call command. After map is created its pinned to bpffs. This makes
it possible to easily and dynamically (without rebuilding programs)
test various corner cases related to map creation.
Map type names are taken from bpftool's array used for printing.
In general these days we try to make use of libbpf type names, but
there are no map type names in libbpf as of today.
As with most features I add the motivation is testing (offloads) :)
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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>
Sock map/hash introduce support for attaching programs to maps. To
date I have been doing this with custom tooling but this is less than
ideal as we shift to using bpftool as the single CLI for our BPF uses.
This patch adds new sub commands 'attach' and 'detach' to the 'prog'
command to attach programs to maps and then detach them.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding EXTRA_LDFLAGS allowing user to specify extra flags
for LD_FLAGS variable. Also adding LDFLAGS to build command
line.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Since map lookup error can be ENOENT or EOPNOTSUPP, let's print
strerror() as error message in normal and JSON output.
This patch adds helper function print_entry_error() to print
entry from lookup error occurs
Example: Following example dumps a map which does not support lookup.
Output before:
root# bpftool map -jp dump id 40
[
"key": ["0x0a","0x00","0x00","0x00"
],
"value": {
"error": "can\'t lookup element"
},
"key": ["0x0b","0x00","0x00","0x00"
],
"value": {
"error": "can\'t lookup element"
}
]
root# bpftool map dump id 40
can't lookup element with key:
0a 00 00 00
can't lookup element with key:
0b 00 00 00
Found 0 elements
Output after changes:
root# bpftool map dump -jp id 45
[
"key": ["0x0a","0x00","0x00","0x00"
],
"value": {
"error": "Operation not supported"
},
"key": ["0x0b","0x00","0x00","0x00"
],
"value": {
"error": "Operation not supported"
}
]
root# bpftool map dump id 45
key:
0a 00 00 00
value:
Operation not supported
key:
0b 00 00 00
value:
Operation not supported
Found 0 elements
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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>
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>
Print `bpftool net` output to stdout instead of stderr. Only errors
should be printed to stderr. Regular output should go to stdout and this
is what all other subcommands of bpftool do, including --json and
--pretty formats of `bpftool net` itself.
Fixes: commit f6f3bac08f ("tools/bpf: bpftool: add net support")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This is a followup patch for Commit f6f3bac08f
("tools/bpf: bpftool: add net support").
Some improvements are made for the bpftool net output.
Specially, plain output is more concise such that
per attachment should nicely fit in one line.
Compared to previous output, the prog tag is removed
since it can be easily obtained with program id.
Similar to xdp attachments, the device name is added
to tc attachments.
The bpf program attached through shared block
mechanism is supported as well.
$ ip link add dev v1 type veth peer name v2
$ tc qdisc add dev v1 ingress_block 10 egress_block 20 clsact
$ tc qdisc add dev v2 ingress_block 10 egress_block 20 clsact
$ tc filter add block 10 protocol ip prio 25 bpf obj bpf_shared.o sec ingress flowid 1:1
$ tc filter add block 20 protocol ip prio 30 bpf obj bpf_cyclic.o sec classifier flowid 1:1
$ bpftool net
xdp:
tc:
v2(7) clsact/ingress bpf_shared.o:[ingress] id 23
v2(7) clsact/egress bpf_cyclic.o:[classifier] id 24
v1(8) clsact/ingress bpf_shared.o:[ingress] id 23
v1(8) clsact/egress bpf_cyclic.o:[classifier] id 24
The documentation and "bpftool net help" are updated
to make it clear that current implementation only
supports xdp and tc attachments. For programs
attached to cgroups, "bpftool cgroup" can be used
to dump attachments. For other programs e.g.
sk_{filter,skb,msg,reuseport} and lwt/seg6,
iproute2 tools should be used.
The new output:
$ bpftool net
xdp:
eth0(2) driver id 198
tc:
eth0(2) clsact/ingress fbflow_icmp id 335 act [{icmp_action id 336}]
eth0(2) clsact/egress fbflow_egress id 334
$ bpftool -jp net
[{
"xdp": [{
"devname": "eth0",
"ifindex": 2,
"mode": "driver",
"id": 198
}
],
"tc": [{
"devname": "eth0",
"ifindex": 2,
"kind": "clsact/ingress",
"name": "fbflow_icmp",
"id": 335,
"act": [{
"name": "icmp_action",
"id": 336
}
]
},{
"devname": "eth0",
"ifindex": 2,
"kind": "clsact/egress",
"name": "fbflow_egress",
"id": 334
}
]
}
]
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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>
Yonghong Song
Jakub Kicinski
Quentin Monnet
Daniel Borkmann
John Fastabend
Jiri Olsa
Prashant Bhole
Andrey Ignatov
Roman Gushchin
Petar Penkov