The tests would break without this patch, because at one point it calls
getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen)
This getsockopt receives the kernel-set -EINVAL. Prior to this patch
series, the eBPF getsockopt hook's -EPERM would override kernel's
-EINVAL, however, after this patch series, return 0's automatic
-EPERM will not; the eBPF prog has to explicitly bpf_set_retval(-EPERM)
if that is wanted.
I also removed the explicit mentions of EPERM in the comments in the
prog.
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/4f20b77cb46812dbc2bdcd7e3fa87c7573bde55e.1639619851.git.zhuyifei@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since there is no convenient way for bpf program to get PAGE_SIZE
from inside of the kernel, pass the value from userspace.
Zero-initialize the variable in bpf prog, otherwise it will cause
problems on some versions of Clang.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-3-yauheni.kaliuta@redhat.com
Switch the test to use BPF skeleton to save some boilerplate and
make it easy to access bpf program bss segment.
The latter will be used to pass PAGE_SIZE from userspace since there
is no convenient way for bpf program to get it from inside of the
kernel.
Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-2-yauheni.kaliuta@redhat.com
Add custom implementation of getsockopt hook for TCP_ZEROCOPY_RECEIVE.
We skip generic hooks for TCP_ZEROCOPY_RECEIVE and have a custom
call in do_tcp_getsockopt using the on-stack data. This removes
3% overhead for locking/unlocking the socket.
Without this patch:
3.38% 0.07% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt
|
--3.30%--__cgroup_bpf_run_filter_getsockopt
|
--0.81%--__kmalloc
With the patch applied:
0.52% 0.12% tcp_mmap [kernel.kallsyms] [k] __cgroup_bpf_run_filter_getsockopt_kern
Note, exporting uapi/tcp.h requires removing netinet/tcp.h
from test_progs.h because those headers have confliciting
definitions.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210115163501.805133-2-sdf@google.com
getsetsockopt() calls getsockopt() with optlen == 1, but then checks
the resulting int. It is ok on little endian, but not on big endian.
Fix by checking char instead.
Fixes: 8a027dc0d8 ("selftests/bpf: add sockopt test that exercises sk helpers")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200915113928.3768496-1-iii@linux.ibm.com
We are relying on the fact, that we can pass > sizeof(int) optvals
to the SOL_IP+IP_FREEBIND option (the kernel will take first 4 bytes).
In the BPF program we check that we can only touch PAGE_SIZE bytes,
but the real optlen is PAGE_SIZE * 2. In both cases, we override it to
some predefined value and trim the optlen.
Also, let's modify exiting IP_TOS usecase to test optlen=0 case
where BPF program just bypasses the data as is.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200617010416.93086-2-sdf@google.com
