netlink/bpf_linux.go

54 lines
1.1 KiB
Go

package netlink
import (
"unsafe"
"golang.org/x/sys/unix"
)
type BpfProgType uint32
const (
BPF_PROG_TYPE_UNSPEC BpfProgType = iota
BPF_PROG_TYPE_SOCKET_FILTER
BPF_PROG_TYPE_KPROBE
BPF_PROG_TYPE_SCHED_CLS
BPF_PROG_TYPE_SCHED_ACT
BPF_PROG_TYPE_TRACEPOINT
BPF_PROG_TYPE_XDP
)
type BPFAttr struct {
ProgType uint32
InsnCnt uint32
Insns uintptr
License uintptr
LogLevel uint32
LogSize uint32
LogBuf uintptr
KernVersion uint32
}
// loadSimpleBpf loads a trivial bpf program for testing purposes.
func loadSimpleBpf(progType BpfProgType, ret uint32) (int, error) {
insns := []uint64{
0x00000000000000b7 | (uint64(ret) << 32),
0x0000000000000095,
}
license := []byte{'A', 'S', 'L', '2', '\x00'}
attr := BPFAttr{
ProgType: uint32(progType),
InsnCnt: uint32(len(insns)),
Insns: uintptr(unsafe.Pointer(&insns[0])),
License: uintptr(unsafe.Pointer(&license[0])),
}
fd, _, errno := unix.Syscall(unix.SYS_BPF,
5, /* bpf cmd */
uintptr(unsafe.Pointer(&attr)),
unsafe.Sizeof(attr))
if errno != 0 {
return 0, errno
}
return int(fd), nil
}