can't run xdp_dump

[FrelDX]

[root@node01 xdp_dump]# go build

github.com/dropbox/goebpf

In file included from ../../../map.go:13:0:
./bpf_helpers.h:957:15: error: expected declaration specifiers or '...' before 'sizeof'
static_assert(sizeof(__u8) == 1, "wrong_u8_size");
^
./bpf_helpers.h:957:34: error: expected declaration specifiers or '...' before string constant
static_assert(sizeof(__u8) == 1, "wrong_u8_size");
^
./bpf_helpers.h:958:15: error: expected declaration specifiers or '...' before 'sizeof'
static_assert(sizeof(__u16) == 2, "wrong_u16_size");
^
./bpf_helpers.h:958:35: error: expected declaration specifiers or '...' before string constant
static_assert(sizeof(__u16) == 2, "wrong_u16_size");
^
./bpf_helpers.h:959:15: error: expected declaration specifiers or '...' before 'sizeof'
static_assert(sizeof(__u32) == 4, "wrong_u32_size");
^
./bpf_helpers.h:959:35: error: expected declaration specifiers or '...' before string constant
static_assert(sizeof(__u32) == 4, "wrong_u32_size");
^
./bpf_helpers.h:960:15: error: expected declaration specifiers or '...' before 'sizeof'
static_assert(sizeof(__u64) == 8, "wrong_u64_size");
^
./bpf_helpers.h:960:35: error: expected declaration specifiers or '...' before string constant
static_assert(sizeof(__u64) == 8, "wrong_u64_size");
^
[root@node01 xdp_dump]#

[FrelDX]

[root@node01 xdp_dump]# clang -v
clang version 5.0.1 (tags/RELEASE_501/final)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/rh/llvm-toolset-7/root/usr/bin
Found candidate GCC installation: /opt/rh/devtoolset-7/root/usr/lib/gcc/x86_64-redhat-linux/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.2
Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/4.8.5
Selected GCC installation: /opt/rh/devtoolset-7/root/usr/lib/gcc/x86_64-redhat-linux/7
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
[root@node01 xdp_dump]# go version
go version go1.15.14 linux/amd64
[root@node01 xdp_dump]# uname -a
Linux node01 5.4.171-1.el7.elrepo.x86_64 #1 SMP Mon Jan 10 18:01:24 EST 2022 x86_64 x86_64 x86_64 GNU/Linux
[root@node01 xdp_dump]#

[belyalov]

Sounds like your clang compiler is way old, try newer one?

[FrelDX]

https://github.com/dropbox/goebpf/tree/master/examples/xdp/xdp_dump

In this example, only TCP related data will be obtained. Is there an example of obtaining IP layer or Ethernet layer data

[belyalov]

There is no such example.
But you can modify this one a bit, move these lines

goebpf/examples/xdp/xdp_dump/ebpf_prog/xdp_dump.c

Lines 127 to 128 in 8a0799a

	__u64 flags = BPF_F_CURRENT_CPU | (packet_size << 32);
	bpf_perf_event_output(ctx, &perfmap, flags, &evt, sizeof(evt));

Up to somewhere

goebpf/examples/xdp/xdp_dump/ebpf_prog/xdp_dump.c

Lines 80 to 86 in 8a0799a

	// L2
	struct ethhdr *ether = data;
	if (data + sizeof(*ether) > data_end) {
	return XDP_ABORTED;
	}
	// L3

[FrelDX]

When I move the code to the specified location according to what you said, an error is reported, It seems that there are variables that are not defined, I don't understand C language. Can you give me a complete code

[FrelDX]

use of undeclared identifier evt