package internal import ( "fmt" "path/filepath" "runtime" "unsafe" "github.com/cilium/ebpf/internal/unix" ) //go:generate stringer -output syscall_string.go -type=BPFCmd // BPFCmd identifies a subcommand of the bpf syscall. type BPFCmd int // Well known BPF commands. const ( BPF_MAP_CREATE BPFCmd = iota BPF_MAP_LOOKUP_ELEM BPF_MAP_UPDATE_ELEM BPF_MAP_DELETE_ELEM BPF_MAP_GET_NEXT_KEY BPF_PROG_LOAD BPF_OBJ_PIN BPF_OBJ_GET BPF_PROG_ATTACH BPF_PROG_DETACH BPF_PROG_TEST_RUN BPF_PROG_GET_NEXT_ID BPF_MAP_GET_NEXT_ID BPF_PROG_GET_FD_BY_ID BPF_MAP_GET_FD_BY_ID BPF_OBJ_GET_INFO_BY_FD BPF_PROG_QUERY BPF_RAW_TRACEPOINT_OPEN BPF_BTF_LOAD BPF_BTF_GET_FD_BY_ID BPF_TASK_FD_QUERY BPF_MAP_LOOKUP_AND_DELETE_ELEM BPF_MAP_FREEZE BPF_BTF_GET_NEXT_ID BPF_MAP_LOOKUP_BATCH BPF_MAP_LOOKUP_AND_DELETE_BATCH BPF_MAP_UPDATE_BATCH BPF_MAP_DELETE_BATCH BPF_LINK_CREATE BPF_LINK_UPDATE BPF_LINK_GET_FD_BY_ID BPF_LINK_GET_NEXT_ID BPF_ENABLE_STATS BPF_ITER_CREATE ) // BPF wraps SYS_BPF. // // Any pointers contained in attr must use the Pointer type from this package. func BPF(cmd BPFCmd, attr unsafe.Pointer, size uintptr) (uintptr, error) { r1, _, errNo := unix.Syscall(unix.SYS_BPF, uintptr(cmd), uintptr(attr), size) runtime.KeepAlive(attr) var err error if errNo != 0 { err = errNo } return r1, err } type BPFProgAttachAttr struct { TargetFd uint32 AttachBpfFd uint32 AttachType uint32 AttachFlags uint32 ReplaceBpfFd uint32 } func BPFProgAttach(attr *BPFProgAttachAttr) error { _, err := BPF(BPF_PROG_ATTACH, unsafe.Pointer(attr), unsafe.Sizeof(*attr)) return err } type BPFProgDetachAttr struct { TargetFd uint32 AttachBpfFd uint32 AttachType uint32 } func BPFProgDetach(attr *BPFProgDetachAttr) error { _, err := BPF(BPF_PROG_DETACH, unsafe.Pointer(attr), unsafe.Sizeof(*attr)) return err } type bpfObjAttr struct { fileName Pointer fd uint32 fileFlags uint32 } const bpfFSType = 0xcafe4a11 // BPFObjPin wraps BPF_OBJ_PIN. func BPFObjPin(fileName string, fd *FD) error { dirName := filepath.Dir(fileName) var statfs unix.Statfs_t if err := unix.Statfs(dirName, &statfs); err != nil { return err } if uint64(statfs.Type) != bpfFSType { return fmt.Errorf("%s is not on a bpf filesystem", fileName) } value, err := fd.Value() if err != nil { return err } attr := bpfObjAttr{ fileName: NewStringPointer(fileName), fd: value, } _, err = BPF(BPF_OBJ_PIN, unsafe.Pointer(&attr), unsafe.Sizeof(attr)) if err != nil { return fmt.Errorf("pin object %s: %w", fileName, err) } return nil } // BPFObjGet wraps BPF_OBJ_GET. func BPFObjGet(fileName string) (*FD, error) { attr := bpfObjAttr{ fileName: NewStringPointer(fileName), } ptr, err := BPF(BPF_OBJ_GET, unsafe.Pointer(&attr), unsafe.Sizeof(attr)) if err != nil { return nil, fmt.Errorf("get object %s: %w", fileName, err) } return NewFD(uint32(ptr)), nil }