Yaniv reported a compilation error after pulling latest libbpf:
[...]
../libbpf/src/root/usr/include/bpf/bpf_helpers.h:99:10: error:
unknown register name 'r0' in asm
: "r0", "r1", "r2", "r3", "r4", "r5");
[...]
The issue got triggered given Yaniv was compiling tracing programs with native
target (e.g. x86) instead of BPF target, hence no BTF generated vmlinux.h nor
CO-RE used, and later llc with -march=bpf was invoked to compile from LLVM IR
to BPF object file. Given that clang was expecting x86 inline asm and not BPF
one the error complained that these regs don't exist on the former.
Guard bpf_tail_call_static() with defined(__bpf__) where BPF inline asm is valid
to use. BPF tracing programs on more modern kernels use BPF target anyway and
thus the bpf_tail_call_static() function will be available for them. BPF inline
asm is supported since clang 7 (clang <= 6 otherwise throws same above error),
and __bpf_unreachable() since clang 8, therefore include the latter condition
in order to prevent compilation errors for older clang versions. Given even an
old Ubuntu 18.04 LTS has official LLVM packages all the way up to llvm-10, I did
not bother to special case the __bpf_unreachable() inside bpf_tail_call_static()
further.
Also, undo the sockex3_kern's use of bpf_tail_call_static() sample given they
still have the old hacky way to even compile networking progs with native instead
of BPF target so bpf_tail_call_static() won't be defined there anymore.
Fixes: 0e9f6841f6 ("bpf, libbpf: Add bpf_tail_call_static helper for bpf programs")
Reported-by: Yaniv Agman <yanivagman@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Tested-by: Yaniv Agman <yanivagman@gmail.com>
Link: https://lore.kernel.org/bpf/CAMy7=ZUk08w5Gc2Z-EKi4JFtuUCaZYmE4yzhJjrExXpYKR4L8w@mail.gmail.com
Link: https://lore.kernel.org/bpf/20201021203257.26223-1-daniel@iogearbox.net
Because the previous two commit replaced the bpf_load implementation of
the user program with libbpf, the corresponding kernel program's MAP
definition can be replaced with new BTF-defined map syntax.
This commit only updates the samples which uses libbpf API for loading
bpf program not with bpf_load.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200516040608.1377876-6-danieltimlee@gmail.com
Commit 5fbc220862 ("tools/libpf: Add offsetof/container_of macro
in bpf_helpers.h") added macros offsetof/container_of to
bpf_helpers.h. Unfortunately, it caused compilation warnings
below for a few samples/bpf programs:
In file included from /data/users/yhs/work/net-next/samples/bpf/sockex2_kern.c:4:
In file included from /data/users/yhs/work/net-next/include/uapi/linux/in.h:24:
In file included from /data/users/yhs/work/net-next/include/linux/socket.h:8:
In file included from /data/users/yhs/work/net-next/include/linux/uio.h:8:
/data/users/yhs/work/net-next/include/linux/kernel.h:992:9: warning: 'container_of' macro redefined [-Wmacro-redefined]
^
/data/users/yhs/work/net-next/tools/lib/bpf/bpf_helpers.h:46:9: note: previous definition is here
^
1 warning generated.
CLANG-bpf samples/bpf/sockex3_kern.o
In all these cases, bpf_helpers.h is included first, followed by other
standard headers. The macro container_of is defined unconditionally
in kernel.h, causing the compiler warning.
The fix is to move bpf_helpers.h after standard headers.
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/20200513180223.2949987-1-yhs@fb.com
Fix all files in samples/bpf to include libbpf header files with the bpf/
prefix, to be consistent with external users of the library. Also ensure
that all includes of exported libbpf header files (those that are exported
on 'make install' of the library) use bracketed includes instead of quoted.
To make sure no new files are introduced that doesn't include the bpf/
prefix in its include, remove tools/lib/bpf from the include path entirely,
and use tools/lib instead.
Fixes: 6910d7d386 ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk
Split off few legacy things from bpf_helpers.h into separate
bpf_legacy.h file:
- load_{byte|half|word};
- remove extra inner_idx and numa_node fields from bpf_map_def and
introduce bpf_map_def_legacy for use in samples;
- move BPF_ANNOTATE_KV_PAIR into bpf_legacy.h.
Adjust samples and selftests accordingly by either including
bpf_legacy.h and using bpf_map_def_legacy, or switching to BTF-defined
maps altogether.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-3-andriin@fb.com
following commit:
commit d58e468b11 ("flow_dissector: implements flow dissector BPF hook")
added struct bpf_flow_keys which conflicts with the struct with
same name in sockex2_kern.c and sockex3_kern.c
similar to commit:
commit 534e0e52bc ("samples/bpf: fix a compilation failure")
we tried the rename it "flow_keys" but it also conflicted with struct
having same name in include/net/flow_dissector.h. Hence renaming the
struct to "flow_key_record". Also, this commit doesn't fix the
compilation error completely because the similar struct is present in
sockex3_kern.c. Hence renaming it in both files sockex3_user.c and
sockex3_kern.c
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
These samples fail to compile as 'struct flow_keys' conflicts with
definition in net/flow_dissector.h. Fix the same by renaming the
structure used in the sample.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
allow programs read/write skb->mark, tc_index fields and
((struct qdisc_skb_cb *)cb)->data.
mark and tc_index are generically useful in TC.
cb[0]-cb[4] are primarily used to pass arguments from one
program to another called via bpf_tail_call() which can
be seen in sockex3_kern.c example.
All fields of 'struct __sk_buff' are readable to socket and tc_cls_act progs.
mark, tc_index are writeable from tc_cls_act only.
cb[0]-cb[4] are writeable by both sockets and tc_cls_act.
Add verifier tests and improve sample code.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Usage:
$ sudo ./sockex3
IP src.port -> dst.port bytes packets
127.0.0.1.42010 -> 127.0.0.1.12865 1568 8
127.0.0.1.59526 -> 127.0.0.1.33778 11422636 173070
127.0.0.1.33778 -> 127.0.0.1.59526 11260224828 341974
127.0.0.1.12865 -> 127.0.0.1.42010 1832 12
IP src.port -> dst.port bytes packets
127.0.0.1.42010 -> 127.0.0.1.12865 1568 8
127.0.0.1.59526 -> 127.0.0.1.33778 23198092 351486
127.0.0.1.33778 -> 127.0.0.1.59526 22972698518 698616
127.0.0.1.12865 -> 127.0.0.1.42010 1832 12
this example is similar to sockex2 in a way that it accumulates per-flow
statistics, but it does packet parsing differently.
sockex2 inlines full packet parser routine into single bpf program.
This sockex3 example have 4 independent programs that parse vlan, mpls, ip, ipv6
and one main program that starts the process.
bpf_tail_call() mechanism allows each program to be small and be called
on demand potentially multiple times, so that many vlan, mpls, ip in ip,
gre encapsulations can be parsed. These and other protocol parsers can
be added or removed at runtime. TLVs can be parsed in similar manner.
Note, tail_call_cnt dynamic check limits the number of tail calls to 32.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann