diff options
Diffstat (limited to 'vendor/github.com/cilium/ebpf/internal/syscall.go')
-rw-r--r-- | vendor/github.com/cilium/ebpf/internal/syscall.go | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/vendor/github.com/cilium/ebpf/internal/syscall.go b/vendor/github.com/cilium/ebpf/internal/syscall.go new file mode 100644 index 000000000..c80815131 --- /dev/null +++ b/vendor/github.com/cilium/ebpf/internal/syscall.go @@ -0,0 +1,179 @@ +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 BPFEnableStatsAttr struct { + StatsType uint32 +} + +func BPFEnableStats(attr *BPFEnableStatsAttr) (*FD, error) { + ptr, err := BPF(BPF_ENABLE_STATS, unsafe.Pointer(attr), unsafe.Sizeof(*attr)) + if err != nil { + return nil, fmt.Errorf("enable stats: %w", err) + } + return NewFD(uint32(ptr)), nil + +} + +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 +} + +type bpfObjGetInfoByFDAttr struct { + fd uint32 + infoLen uint32 + info Pointer +} + +// BPFObjGetInfoByFD wraps BPF_OBJ_GET_INFO_BY_FD. +// +// Available from 4.13. +func BPFObjGetInfoByFD(fd *FD, info unsafe.Pointer, size uintptr) error { + value, err := fd.Value() + if err != nil { + return err + } + + attr := bpfObjGetInfoByFDAttr{ + fd: value, + infoLen: uint32(size), + info: NewPointer(info), + } + _, err = BPF(BPF_OBJ_GET_INFO_BY_FD, unsafe.Pointer(&attr), unsafe.Sizeof(attr)) + if err != nil { + return fmt.Errorf("fd %v: %w", fd, err) + } + return nil +} |