mirror of https://github.com/k3s-io/k3s
140 lines
2.9 KiB
Go
140 lines
2.9 KiB
Go
package internal
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import (
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"fmt"
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"path/filepath"
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"runtime"
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"unsafe"
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"github.com/cilium/ebpf/internal/unix"
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)
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//go:generate stringer -output syscall_string.go -type=BPFCmd
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// BPFCmd identifies a subcommand of the bpf syscall.
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type BPFCmd int
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// Well known BPF commands.
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const (
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BPF_MAP_CREATE BPFCmd = iota
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BPF_MAP_LOOKUP_ELEM
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BPF_MAP_UPDATE_ELEM
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BPF_MAP_DELETE_ELEM
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BPF_MAP_GET_NEXT_KEY
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BPF_PROG_LOAD
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BPF_OBJ_PIN
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BPF_OBJ_GET
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BPF_PROG_ATTACH
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BPF_PROG_DETACH
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BPF_PROG_TEST_RUN
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BPF_PROG_GET_NEXT_ID
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BPF_MAP_GET_NEXT_ID
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BPF_PROG_GET_FD_BY_ID
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BPF_MAP_GET_FD_BY_ID
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BPF_OBJ_GET_INFO_BY_FD
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BPF_PROG_QUERY
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BPF_RAW_TRACEPOINT_OPEN
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BPF_BTF_LOAD
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BPF_BTF_GET_FD_BY_ID
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BPF_TASK_FD_QUERY
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BPF_MAP_LOOKUP_AND_DELETE_ELEM
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BPF_MAP_FREEZE
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BPF_BTF_GET_NEXT_ID
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BPF_MAP_LOOKUP_BATCH
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BPF_MAP_LOOKUP_AND_DELETE_BATCH
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BPF_MAP_UPDATE_BATCH
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BPF_MAP_DELETE_BATCH
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BPF_LINK_CREATE
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BPF_LINK_UPDATE
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BPF_LINK_GET_FD_BY_ID
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BPF_LINK_GET_NEXT_ID
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BPF_ENABLE_STATS
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BPF_ITER_CREATE
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)
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// BPF wraps SYS_BPF.
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//
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// Any pointers contained in attr must use the Pointer type from this package.
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func BPF(cmd BPFCmd, attr unsafe.Pointer, size uintptr) (uintptr, error) {
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r1, _, errNo := unix.Syscall(unix.SYS_BPF, uintptr(cmd), uintptr(attr), size)
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runtime.KeepAlive(attr)
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var err error
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if errNo != 0 {
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err = errNo
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}
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return r1, err
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}
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type BPFProgAttachAttr struct {
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TargetFd uint32
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AttachBpfFd uint32
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AttachType uint32
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AttachFlags uint32
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ReplaceBpfFd uint32
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}
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func BPFProgAttach(attr *BPFProgAttachAttr) error {
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_, err := BPF(BPF_PROG_ATTACH, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
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return err
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}
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type BPFProgDetachAttr struct {
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TargetFd uint32
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AttachBpfFd uint32
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AttachType uint32
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}
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func BPFProgDetach(attr *BPFProgDetachAttr) error {
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_, err := BPF(BPF_PROG_DETACH, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
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return err
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}
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type bpfObjAttr struct {
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fileName Pointer
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fd uint32
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fileFlags uint32
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}
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const bpfFSType = 0xcafe4a11
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// BPFObjPin wraps BPF_OBJ_PIN.
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func BPFObjPin(fileName string, fd *FD) error {
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dirName := filepath.Dir(fileName)
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var statfs unix.Statfs_t
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if err := unix.Statfs(dirName, &statfs); err != nil {
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return err
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}
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if uint64(statfs.Type) != bpfFSType {
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return fmt.Errorf("%s is not on a bpf filesystem", fileName)
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}
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value, err := fd.Value()
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if err != nil {
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return err
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}
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attr := bpfObjAttr{
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fileName: NewStringPointer(fileName),
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fd: value,
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}
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_, err = BPF(BPF_OBJ_PIN, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
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if err != nil {
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return fmt.Errorf("pin object %s: %w", fileName, err)
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}
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return nil
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}
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// BPFObjGet wraps BPF_OBJ_GET.
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func BPFObjGet(fileName string) (*FD, error) {
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attr := bpfObjAttr{
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fileName: NewStringPointer(fileName),
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}
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ptr, err := BPF(BPF_OBJ_GET, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
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if err != nil {
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return nil, fmt.Errorf("get object %s: %w", fileName, err)
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}
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return NewFD(uint32(ptr)), nil
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}
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