k3s/vendor/github.com/cilium/ebpf/syscalls.go
Brad Davidson 4fbc241679 Update to forked protobuf 1.4.3-k3s1
Signed-off-by: Brad Davidson <brad.davidson@rancher.com>
2021-04-14 14:51:42 -07:00

492 lines
12 KiB
Go

package ebpf
import (
"errors"
"fmt"
"unsafe"
"github.com/cilium/ebpf/internal"
"github.com/cilium/ebpf/internal/btf"
"github.com/cilium/ebpf/internal/unix"
)
// Generic errors returned by BPF syscalls.
var ErrNotExist = errors.New("requested object does not exist")
// bpfObjName is a null-terminated string made up of
// 'A-Za-z0-9_' characters.
type bpfObjName [unix.BPF_OBJ_NAME_LEN]byte
// newBPFObjName truncates the result if it is too long.
func newBPFObjName(name string) bpfObjName {
var result bpfObjName
copy(result[:unix.BPF_OBJ_NAME_LEN-1], name)
return result
}
// invalidBPFObjNameChar returns true if char may not appear in
// a BPF object name.
func invalidBPFObjNameChar(char rune) bool {
dotAllowed := objNameAllowsDot() == nil
switch {
case char >= 'A' && char <= 'Z':
return false
case char >= 'a' && char <= 'z':
return false
case char >= '0' && char <= '9':
return false
case dotAllowed && char == '.':
return false
case char == '_':
return false
default:
return true
}
}
type bpfMapCreateAttr struct {
mapType MapType
keySize uint32
valueSize uint32
maxEntries uint32
flags uint32
innerMapFd uint32 // since 4.12 56f668dfe00d
numaNode uint32 // since 4.14 96eabe7a40aa
mapName bpfObjName // since 4.15 ad5b177bd73f
mapIfIndex uint32
btfFd uint32
btfKeyTypeID btf.TypeID
btfValueTypeID btf.TypeID
}
type bpfMapOpAttr struct {
mapFd uint32
padding uint32
key internal.Pointer
value internal.Pointer
flags uint64
}
type bpfBatchMapOpAttr struct {
inBatch internal.Pointer
outBatch internal.Pointer
keys internal.Pointer
values internal.Pointer
count uint32
mapFd uint32
elemFlags uint64
flags uint64
}
type bpfMapInfo struct {
map_type uint32 // since 4.12 1e2709769086
id uint32
key_size uint32
value_size uint32
max_entries uint32
map_flags uint32
name bpfObjName // since 4.15 ad5b177bd73f
ifindex uint32 // since 4.16 52775b33bb50
btf_vmlinux_value_type_id uint32 // since 5.6 85d33df357b6
netns_dev uint64 // since 4.16 52775b33bb50
netns_ino uint64
btf_id uint32 // since 4.18 78958fca7ead
btf_key_type_id uint32 // since 4.18 9b2cf328b2ec
btf_value_type_id uint32
}
type bpfProgLoadAttr struct {
progType ProgramType
insCount uint32
instructions internal.Pointer
license internal.Pointer
logLevel uint32
logSize uint32
logBuf internal.Pointer
kernelVersion uint32 // since 4.1 2541517c32be
progFlags uint32 // since 4.11 e07b98d9bffe
progName bpfObjName // since 4.15 067cae47771c
progIfIndex uint32 // since 4.15 1f6f4cb7ba21
expectedAttachType AttachType // since 4.17 5e43f899b03a
progBTFFd uint32
funcInfoRecSize uint32
funcInfo internal.Pointer
funcInfoCnt uint32
lineInfoRecSize uint32
lineInfo internal.Pointer
lineInfoCnt uint32
attachBTFID btf.TypeID
attachProgFd uint32
}
type bpfProgInfo struct {
prog_type uint32
id uint32
tag [unix.BPF_TAG_SIZE]byte
jited_prog_len uint32
xlated_prog_len uint32
jited_prog_insns internal.Pointer
xlated_prog_insns internal.Pointer
load_time uint64 // since 4.15 cb4d2b3f03d8
created_by_uid uint32
nr_map_ids uint32
map_ids internal.Pointer
name bpfObjName // since 4.15 067cae47771c
ifindex uint32
gpl_compatible uint32
netns_dev uint64
netns_ino uint64
nr_jited_ksyms uint32
nr_jited_func_lens uint32
jited_ksyms internal.Pointer
jited_func_lens internal.Pointer
btf_id uint32
func_info_rec_size uint32
func_info internal.Pointer
nr_func_info uint32
nr_line_info uint32
line_info internal.Pointer
jited_line_info internal.Pointer
nr_jited_line_info uint32
line_info_rec_size uint32
jited_line_info_rec_size uint32
nr_prog_tags uint32
prog_tags internal.Pointer
run_time_ns uint64
run_cnt uint64
}
type bpfProgTestRunAttr struct {
fd uint32
retval uint32
dataSizeIn uint32
dataSizeOut uint32
dataIn internal.Pointer
dataOut internal.Pointer
repeat uint32
duration uint32
}
type bpfGetFDByIDAttr struct {
id uint32
next uint32
}
type bpfMapFreezeAttr struct {
mapFd uint32
}
type bpfObjGetNextIDAttr struct {
startID uint32
nextID uint32
openFlags uint32
}
func bpfProgLoad(attr *bpfProgLoadAttr) (*internal.FD, error) {
for {
fd, err := internal.BPF(internal.BPF_PROG_LOAD, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
// As of ~4.20 the verifier can be interrupted by a signal,
// and returns EAGAIN in that case.
if err == unix.EAGAIN {
continue
}
if err != nil {
return nil, err
}
return internal.NewFD(uint32(fd)), nil
}
}
func bpfProgTestRun(attr *bpfProgTestRunAttr) error {
_, err := internal.BPF(internal.BPF_PROG_TEST_RUN, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
return err
}
func bpfMapCreate(attr *bpfMapCreateAttr) (*internal.FD, error) {
fd, err := internal.BPF(internal.BPF_MAP_CREATE, unsafe.Pointer(attr), unsafe.Sizeof(*attr))
if err != nil {
return nil, err
}
return internal.NewFD(uint32(fd)), nil
}
var haveNestedMaps = internal.FeatureTest("nested maps", "4.12", func() error {
_, err := bpfMapCreate(&bpfMapCreateAttr{
mapType: ArrayOfMaps,
keySize: 4,
valueSize: 4,
maxEntries: 1,
// Invalid file descriptor.
innerMapFd: ^uint32(0),
})
if errors.Is(err, unix.EINVAL) {
return internal.ErrNotSupported
}
if errors.Is(err, unix.EBADF) {
return nil
}
return err
})
var haveMapMutabilityModifiers = internal.FeatureTest("read- and write-only maps", "5.2", func() error {
// This checks BPF_F_RDONLY_PROG and BPF_F_WRONLY_PROG. Since
// BPF_MAP_FREEZE appeared in 5.2 as well we don't do a separate check.
m, err := bpfMapCreate(&bpfMapCreateAttr{
mapType: Array,
keySize: 4,
valueSize: 4,
maxEntries: 1,
flags: unix.BPF_F_RDONLY_PROG,
})
if err != nil {
return internal.ErrNotSupported
}
_ = m.Close()
return nil
})
func bpfMapLookupElem(m *internal.FD, key, valueOut internal.Pointer) error {
fd, err := m.Value()
if err != nil {
return err
}
attr := bpfMapOpAttr{
mapFd: fd,
key: key,
value: valueOut,
}
_, err = internal.BPF(internal.BPF_MAP_LOOKUP_ELEM, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
return wrapMapError(err)
}
func bpfMapLookupAndDelete(m *internal.FD, key, valueOut internal.Pointer) error {
fd, err := m.Value()
if err != nil {
return err
}
attr := bpfMapOpAttr{
mapFd: fd,
key: key,
value: valueOut,
}
_, err = internal.BPF(internal.BPF_MAP_LOOKUP_AND_DELETE_ELEM, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
return wrapMapError(err)
}
func bpfMapUpdateElem(m *internal.FD, key, valueOut internal.Pointer, flags uint64) error {
fd, err := m.Value()
if err != nil {
return err
}
attr := bpfMapOpAttr{
mapFd: fd,
key: key,
value: valueOut,
flags: flags,
}
_, err = internal.BPF(internal.BPF_MAP_UPDATE_ELEM, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
return wrapMapError(err)
}
func bpfMapDeleteElem(m *internal.FD, key internal.Pointer) error {
fd, err := m.Value()
if err != nil {
return err
}
attr := bpfMapOpAttr{
mapFd: fd,
key: key,
}
_, err = internal.BPF(internal.BPF_MAP_DELETE_ELEM, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
return wrapMapError(err)
}
func bpfMapGetNextKey(m *internal.FD, key, nextKeyOut internal.Pointer) error {
fd, err := m.Value()
if err != nil {
return err
}
attr := bpfMapOpAttr{
mapFd: fd,
key: key,
value: nextKeyOut,
}
_, err = internal.BPF(internal.BPF_MAP_GET_NEXT_KEY, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
return wrapMapError(err)
}
func objGetNextID(cmd internal.BPFCmd, start uint32) (uint32, error) {
attr := bpfObjGetNextIDAttr{
startID: start,
}
_, err := internal.BPF(cmd, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
return attr.nextID, wrapObjError(err)
}
func bpfMapBatch(cmd internal.BPFCmd, m *internal.FD, inBatch, outBatch, keys, values internal.Pointer, count uint32, opts *BatchOptions) (uint32, error) {
fd, err := m.Value()
if err != nil {
return 0, err
}
attr := bpfBatchMapOpAttr{
inBatch: inBatch,
outBatch: outBatch,
keys: keys,
values: values,
count: count,
mapFd: fd,
}
if opts != nil {
attr.elemFlags = opts.ElemFlags
attr.flags = opts.Flags
}
_, err = internal.BPF(cmd, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
// always return count even on an error, as things like update might partially be fulfilled.
return attr.count, wrapMapError(err)
}
func wrapObjError(err error) error {
if err == nil {
return nil
}
if errors.Is(err, unix.ENOENT) {
return fmt.Errorf("%w", ErrNotExist)
}
return errors.New(err.Error())
}
func wrapMapError(err error) error {
if err == nil {
return nil
}
if errors.Is(err, unix.ENOENT) {
return ErrKeyNotExist
}
if errors.Is(err, unix.EEXIST) {
return ErrKeyExist
}
if errors.Is(err, unix.ENOTSUPP) {
return ErrNotSupported
}
return err
}
func bpfMapFreeze(m *internal.FD) error {
fd, err := m.Value()
if err != nil {
return err
}
attr := bpfMapFreezeAttr{
mapFd: fd,
}
_, err = internal.BPF(internal.BPF_MAP_FREEZE, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
return err
}
func bpfGetProgInfoByFD(fd *internal.FD) (*bpfProgInfo, error) {
var info bpfProgInfo
if err := internal.BPFObjGetInfoByFD(fd, unsafe.Pointer(&info), unsafe.Sizeof(info)); err != nil {
return nil, fmt.Errorf("can't get program info: %w", err)
}
return &info, nil
}
func bpfGetMapInfoByFD(fd *internal.FD) (*bpfMapInfo, error) {
var info bpfMapInfo
err := internal.BPFObjGetInfoByFD(fd, unsafe.Pointer(&info), unsafe.Sizeof(info))
if err != nil {
return nil, fmt.Errorf("can't get map info: %w", err)
}
return &info, nil
}
var haveObjName = internal.FeatureTest("object names", "4.15", func() error {
attr := bpfMapCreateAttr{
mapType: Array,
keySize: 4,
valueSize: 4,
maxEntries: 1,
mapName: newBPFObjName("feature_test"),
}
fd, err := bpfMapCreate(&attr)
if err != nil {
return internal.ErrNotSupported
}
_ = fd.Close()
return nil
})
var objNameAllowsDot = internal.FeatureTest("dot in object names", "5.2", func() error {
if err := haveObjName(); err != nil {
return err
}
attr := bpfMapCreateAttr{
mapType: Array,
keySize: 4,
valueSize: 4,
maxEntries: 1,
mapName: newBPFObjName(".test"),
}
fd, err := bpfMapCreate(&attr)
if err != nil {
return internal.ErrNotSupported
}
_ = fd.Close()
return nil
})
var haveBatchAPI = internal.FeatureTest("map batch api", "5.6", func() error {
var maxEntries uint32 = 2
attr := bpfMapCreateAttr{
mapType: Hash,
keySize: 4,
valueSize: 4,
maxEntries: maxEntries,
}
fd, err := bpfMapCreate(&attr)
if err != nil {
return internal.ErrNotSupported
}
defer fd.Close()
keys := []uint32{1, 2}
values := []uint32{3, 4}
kp, _ := marshalPtr(keys, 8)
vp, _ := marshalPtr(values, 8)
nilPtr := internal.NewPointer(nil)
_, err = bpfMapBatch(internal.BPF_MAP_UPDATE_BATCH, fd, nilPtr, nilPtr, kp, vp, maxEntries, nil)
if err != nil {
return internal.ErrNotSupported
}
return nil
})
func bpfObjGetFDByID(cmd internal.BPFCmd, id uint32) (*internal.FD, error) {
attr := bpfGetFDByIDAttr{
id: id,
}
ptr, err := internal.BPF(cmd, unsafe.Pointer(&attr), unsafe.Sizeof(attr))
return internal.NewFD(uint32(ptr)), wrapObjError(err)
}