bpf

package
v0.8.20 Latest Latest
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 Go to latest Published: Mar 14, 2023 License: Apache-2.0 Imports: 27 Imported by: 0

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Index

Constants

View Source 
const (
	PERF_TYPE_SOFTWARE = 1

	PERF_SAMPLE_RAW          = 1 << 10
	PERF_COUNT_SW_BPF_OUTPUT = 10

	// BPF map type constants. Must match enum bpf_map_type from linux/bpf.h
	BPF_MAP_TYPE_UNSPEC              = 0
	BPF_MAP_TYPE_HASH                = 1
	BPF_MAP_TYPE_ARRAY               = 2
	BPF_MAP_TYPE_PROG_ARRAY          = 3
	BPF_MAP_TYPE_PERF_EVENT_ARRAY    = 4
	BPF_MAP_TYPE_PERCPU_HASH         = 5
	BPF_MAP_TYPE_PERCPU_ARRAY        = 6
	BPF_MAP_TYPE_STACK_TRACE         = 7
	BPF_MAP_TYPE_CGROUP_ARRAY        = 8
	BPF_MAP_TYPE_LRU_HASH            = 9
	BPF_MAP_TYPE_LRU_PERCPU_HASH     = 10
	BPF_MAP_TYPE_LPM_TRIE            = 11
	BPF_MAP_TYPE_ARRAY_OF_MAPS       = 12
	BPF_MAP_TYPE_HASH_OF_MAPS        = 13
	BPF_MAP_TYPE_DEVMAP              = 14
	BPF_MAP_TYPE_SOCKMAP             = 15
	BPF_MAP_TYPE_CPUMAP              = 16
	BPF_MAP_TYPE_XSKMAP              = 17
	BPF_MAP_TYPE_SOCKHASH            = 18
	BPF_MAP_TYPE_CGROUP_STORAGE      = 19
	BPF_MAP_TYPE_REUSEPORT_SOCKARRAY = 20

	// BPF syscall command constants. Must match enum bpf_cmd from linux/bpf.h
	BPF_MAP_CREATE          = 0
	BPF_MAP_LOOKUP_ELEM     = 1
	BPF_MAP_UPDATE_ELEM     = 2
	BPF_MAP_DELETE_ELEM     = 3
	BPF_MAP_GET_NEXT_KEY    = 4
	BPF_PROG_LOAD           = 5
	BPF_OBJ_PIN             = 6
	BPF_OBJ_GET             = 7
	BPF_PROG_ATTACH         = 8
	BPF_PROG_DETACH         = 9
	BPF_PROG_TEST_RUN       = 10
	BPF_PROG_GET_NEXT_ID    = 11
	BPF_MAP_GET_NEXT_ID     = 12
	BPF_PROG_GET_FD_BY_ID   = 13
	BPF_MAP_GET_FD_BY_ID    = 14
	BPF_OBJ_GET_INFO_BY_FD  = 15
	BPF_PROG_QUERY          = 16
	BPF_RAW_TRACEPOINT_OPEN = 17
	BPF_BTF_LOAD            = 18
	BPF_BTF_GET_FD_BY_ID    = 19
	BPF_TASK_FD_QUERY       = 20

	// BPF syscall attach types
	BPF_CGROUP_INET_INGRESS     = 0
	BPF_CGROUP_INET_EGRESS      = 1
	BPF_CGROUP_INET_SOCK_CREATE = 2
	BPF_CGROUP_SOCK_OPS         = 3
	BPF_SK_SKB_STREAM_PARSER    = 4
	BPF_SK_SKB_STREAM_VERDICT   = 5
	BPF_CGROUP_DEVICE           = 6
	BPF_SK_MSG_VERDICT          = 7
	BPF_CGROUP_INET4_BIND       = 8
	BPF_CGROUP_INET6_BIND       = 9
	BPF_CGROUP_INET4_CONNECT    = 10
	BPF_CGROUP_INET6_CONNECT    = 11
	BPF_CGROUP_INET4_POST_BIND  = 12
	BPF_CGROUP_INET6_POST_BIND  = 13
	BPF_CGROUP_UDP4_SENDMSG     = 14
	BPF_CGROUP_UDP6_SENDMSG     = 15
	BPF_LIRC_MODE2              = 16
	BPF_FLOW_DISSECTOR          = 17
	BPF_CGROUP_SYSCTL           = 18
	BPF_CGROUP_UDP4_RECVMSG     = 19
	BPF_CGROUP_UDP6_RECVMSG     = 20

	// Flags for BPF_MAP_UPDATE_ELEM. Must match values from linux/bpf.h
	BPF_ANY     = 0
	BPF_NOEXIST = 1
	BPF_EXIST   = 2

	// Flags for BPF_MAP_CREATE. Must match values from linux/bpf.h
	BPF_F_NO_PREALLOC   = 1 << 0
	BPF_F_NO_COMMON_LRU = 1 << 1
	BPF_F_NUMA_NODE     = 1 << 2

	// Flags for BPF_PROG_QUERY
	BPF_F_QUERY_EFFECTVE = 1 << 0

	// Flags for accessing BPF object
	BPF_F_RDONLY = 1 << 3
	BPF_F_WRONLY = 1 << 4

	// Flag for stack_map, store build_id+offset instead of pointer
	BPF_F_STACK_BUILD_ID = 1 << 5

	// Build ID flags bit for perf_event_open
	PerfBitBuildId = unix.CBitFieldMaskBit34
)
View Source 
const (
	MAX_POLL_EVENTS = 32

	PossibleCPUSysfsPath = "/sys/devices/system/cpu/possible"
)

Variables

This section is empty.

Functions

func AttachTCIngress 

func AttachTCIngress(progFd int, linkName string, ingress bool) error

func CheckOrMountCgroup2 

func CheckOrMountCgroup2() error

func CheckOrMountDebugFS 

func CheckOrMountDebugFS() error

func CheckOrMountFS 

func CheckOrMountFS(bpfRoot string)

CheckOrMountFS checks or mounts the BPF filesystem and then opens/creates/deletes all maps which have previously been scheduled to be opened/created/deleted.

func ConfigureResourceLimits 

func ConfigureResourceLimits() error

func ConvertKeyValue 

func ConvertKeyValue(bKey []byte, bValue []byte, key MapKey, value MapValue) (MapKey, MapValue, error)

ConvertKeyValue converts key and value from bytes to given Golang struct pointers.

func Environment 

func Environment() []string

Environment returns a list of environment variables which are needed to make BPF programs and tc aware of the actual BPFFS mount path.

func GetFirstKey 

func GetFirstKey(fd int, nextKey unsafe.Pointer) error

GetFirstKey fetches the first key in the map.

func GetMapRoot 

func GetMapRoot() string

func GetNextKey 

func GetNextKey(fd int, key, nextKey unsafe.Pointer) error

GetNextKey stores, in nextKey, the next key after the key of the map in fd. Deprecated, use GetNextKeyFromPointers

func GetNextKeyFromPointers 

func GetNextKeyFromPointers(fd int, structPtr, sizeOfStruct uintptr) error

GetNextKeyFromPointers stores, in nextKey, the next key after the key of the map in fd.

func GetNumPossibleCPUs 

func GetNumPossibleCPUs() int

GetNumPossibleCPUs returns a total number of possible CPUS, i.e. CPUs that have been allocated resources and can be brought online if they are present. The number is retrieved by parsing /sys/device/system/cpu/possible.

See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/cpumask.h?h=v4.19#n50 for more details.

func HasBuildId 

func HasBuildId() bool

func HasKprobeMulti 

func HasKprobeMulti() bool

func HasOverrideHelper 

func HasOverrideHelper() bool

func LocalMapName 

func LocalMapName(name string, id uint16) string

LocalMapName returns the name for a BPF map that is local to the specified ID.

func LocalMapPath 

func LocalMapPath(name string, id uint16) string

LocalMapPath returns the path for a BPF map that is local to the specified ID.

func LookupElement 

func LookupElement(fd int, key, value unsafe.Pointer) error

LookupElement looks up for the map value stored in fd with the given key. The value is stored in the value unsafe.Pointer. Deprecated, use LookupElementFromPointers

func LookupElementFromPointers 

func LookupElementFromPointers(fd int, structPtr, sizeOfStruct uintptr) error

LookupElement looks up for the map value stored in fd with the given key. The value is stored in the value unsafe.Pointer.

func MapPath 

func MapPath(name string) string

MapPath returns a path for a BPF map with a given name.

func MapPrefixPath 

func MapPrefixPath() string

func ObjGet 

func ObjGet(pathname string) (int, error)

ObjGet reads the pathname and returns the map's fd read.

func QdiscTCInsert 

func QdiscTCInsert(linkName string, ingress bool) error

func SetMapPrefix 

func SetMapPrefix(path string)

func SetMapRoot 

func SetMapRoot(path string)

func UpdateElement 

func UpdateElement(fd int, key, value unsafe.Pointer, flags uint64) error

func UpdateElementFromPointers 

func UpdateElementFromPointers(fd int, structPtr, sizeOfStruct uintptr) error

Types

type DesiredAction 

type DesiredAction int

DesiredAction is the action to be performed on the BPF map 

const (
	// OK indicates that to further action is required and the entry is in
	// sync
	OK DesiredAction = iota

	// Insert indicates that the entry needs to be created or updated
	Insert

	// Delete indicates that the entry needs to be deleted
	Delete
)

type DumpCallback 

type DumpCallback func(m *Map, key MapKey, value MapValue)

type EPoll 

type EPoll struct {
	// contains filtered or unexported fields
}

func (*EPoll) AddFD 

func (ep *EPoll) AddFD(fd int, events uint32) error

func (*EPoll) Close 

func (ep *EPoll) Close()

func (*EPoll) Poll 

func (ep *EPoll) Poll(timeoutMillis int) (int, error)

type ErrorFunc 

type ErrorFunc func(msg *PerfEvent)

ErrorFunc is run when reading PerfEvent results in an error

type EventMap 

type EventMap struct {
	// contains filtered or unexported fields
}

func (*EventMap) Close 

func (e *EventMap) Close()

func (*EventMap) Update 

func (e *EventMap) Update(fd int, ubaPtr, sizeOf uintptr) error

type Feature 

type Feature struct {
	// contains filtered or unexported fields
}

type LostFunc 

type LostFunc func(msg *PerfEventLost, cpu int)

type Map 

type Map struct {
	MapInfo
	// contains filtered or unexported fields
}

func OpenMap 

func OpenMap(name string) (*Map, error)

OpenMap opens the given bpf map and generates the Map info based in the information stored in the bpf map. *Warning*: Calling this function requires the caller to properly setup the MapInfo.MapKey and MapInfo.MapValues fields as those structures are not stored in the bpf map.

func (*Map) Close 

func (m *Map) Close() error

func (*Map) Count 

func (m *Map) Count() (int, error)

Count returns the number of elements in the map by iterating over it with BPF_MAP_GET_NEXT_KEY.

func (*Map) DeleteKey 

func (m *Map) DeleteKey(key MapKey) error

deleteMapEntry deletes the map entry corresponding to the given key. If ignoreMissing is set to true and the entry is not found, then the error metric is not incremented for missing entries and nil error is returned.

func (*Map) Dump 

func (m *Map) Dump(hash map[string][]string) error

Dump returns the map (type map[string][]string) which contains all data stored in BPF map.

func (*Map) DumpIfExists 

func (m *Map) DumpIfExists(hash map[string][]string) error

DumpIfExists dumps the contents of the map into hash via Dump() if the map file exists

func (*Map) DumpWithCallback 

func (m *Map) DumpWithCallback(cb DumpCallback) error

DumpWithCallback iterates over the Map and calls the given callback function on each iteration. That callback function is receiving the actual key and value. The callback function should consider creating a deepcopy of the key and value on between each iterations to avoid memory corruption.

func (*Map) DumpWithCallbackIfExists 

func (m *Map) DumpWithCallbackIfExists(cb DumpCallback) error

DumpWithCallbackIfExists is similar to DumpWithCallback, but returns earlier if the given map does not exist.

func (*Map) GetFd 

func (m *Map) GetFd() int

func (*Map) Lookup 

func (m *Map) Lookup(key MapKey) (MapValue, error)

func (*Map) Name 

func (m *Map) Name() string

Name returns the basename of this map.

func (*Map) Open 

func (m *Map) Open() error

func (*Map) Path 

func (m *Map) Path() string

Path returns the path to this map on the filesystem.

func (*Map) Reopen 

func (m *Map) Reopen() error

Reopen attempts to close and re-open the received map.

func (*Map) Update 

func (m *Map) Update(key MapKey, value MapValue) error

type MapInfo 

type MapInfo struct {
	MapType  MapType
	MapKey   MapKey
	KeySize  uint32
	MapValue MapValue
	// ReadValueSize is the value size that is used to read from the BPF maps
	// this value an the ValueSize values can be different for BPF_MAP_TYPE_PERCPU_HASH
	// for example.
	ReadValueSize uint32
	ValueSize     uint32
	MaxEntries    uint32
	Flags         uint32
	InnerID       uint32
}

func GetMapInfo 

func GetMapInfo(pid int, fd int) (*MapInfo, error)

type MapKey 

type MapKey interface {
	fmt.Stringer

	// Returns pointer to start of key
	GetKeyPtr() unsafe.Pointer

	// Allocates a new value matching the key type
	NewValue() MapValue

	// DeepCopyMapKey returns a deep copy of the map key
	DeepCopyMapKey() MapKey
}

type MapType 

type MapType int

MapType is an enumeration for valid BPF map types 

const (
	MapTypeUnspec MapType = iota
	MapTypeHash
	MapTypeArray
	MapTypeProgArray
	MapTypePerfEventArray
	MapTypePerCPUHash
	MapTypePerCPUArray
	MapTypeStackTrace
	MapTypeCgroupArray
	MapTypeLRUHash
	MapTypeLRUPerCPUHash
	MapTypeLPMTrie
	MapTypeArrayOfMaps
	MapTypeHashOfMaps
	MapTypeDevMap
	MapTypeSockMap
	MapTypeCPUMap
	MapTypeXSKMap
	MapTypeSockHash
	// MapTypeMaximum is the maximum supported known map type.
	MapTypeMaximum
)

This enumeration must be in sync with enum bpf_prog_type in <linux/bpf.h>

func (MapType) String 

func (t MapType) String() string

type MapValidator 

type MapValidator func(path string) (bool, error)

type MapValue 

type MapValue interface {
	fmt.Stringer

	// Returns pointer to start of value
	GetValuePtr() unsafe.Pointer

	// DeepCopyMapValue returns a deep copy of the map value
	DeepCopyMapValue() MapValue
}

type PerCpuEvents 

type PerCpuEvents struct {
	Cpus     int
	Npages   int
	Pagesize int
	// contains filtered or unexported fields
}

func NewPerCpuEvents 

func NewPerCpuEvents(config *PerfEventConfig, log logrus.FieldLogger) (*PerCpuEvents, error)

func (*PerCpuEvents) CloseAll 

func (e *PerCpuEvents) CloseAll() error

func (*PerCpuEvents) Poll 

func (e *PerCpuEvents) Poll(timeoutMillis int) (int, error)

func (*PerCpuEvents) ReadAll 

func (e *PerCpuEvents) ReadAll(maxEvents int, receive ReceiveFunc, lost LostFunc, handleError ErrorFunc) error

ReadAll reads perf events

func (*PerCpuEvents) Stats 

func (e *PerCpuEvents) Stats() (uint64, uint64, uint64)

type PerfEvent 

type PerfEvent struct {
	Fd int
	// contains filtered or unexported fields
}

func PerfEventFromMemory 

func PerfEventFromMemory(page *PerfEventMmapPage, buf []byte) *PerfEvent

PerfEventFromMemory creates an in-memory PerfEvent object for testing and analysis purposes. No kernel interaction is made.

The caller MUST eventually call Disable() to free event resources.

func PerfEventOpen 

func PerfEventOpen(config *PerfEventConfig, pid int, cpu int, groupFD int, flags int) (*PerfEvent, error)

func (*PerfEvent) Close 

func (e *PerfEvent) Close()

func (*PerfEvent) Debug 

func (e *PerfEvent) Debug() string

Debug returns string with internal information about PerfEvent

func (*PerfEvent) DebugDump 

func (e *PerfEvent) DebugDump() string

func (*PerfEvent) Disable 

func (e *PerfEvent) Disable() error

func (*PerfEvent) Enable 

func (e *PerfEvent) Enable() error

func (*PerfEvent) Mmap 

func (e *PerfEvent) Mmap(pagesize int, npages int) error

func (*PerfEvent) Munmap 

func (e *PerfEvent) Munmap() error

func (*PerfEvent) Read 

func (e *PerfEvent) Read(maxEvents int, receive ReceiveFunc, lostFn LostFunc, err ErrorFunc) (nread int)

Read attempts to read at most 'maxEvents' events from the perf event buffer, calling one of the receive / lost functions for each event. receiveFn is called when the event is a valid sample; lostFn is called when the kernel has attempted to write an event into the ringbuffer but ran out of space for the event.

If all events are not read within a time period (default 20s), it will call errFn() and stop reading events.

Returns the number of events read from the ring.

type PerfEventConfig 

type PerfEventConfig struct {
	NumCpus      int
	NumPages     int
	MapName      string
	Type         int
	Config       int
	SampleType   int
	WakeupEvents int
}

func DefaultPerfEventConfig 

func DefaultPerfEventConfig() *PerfEventConfig

DefaultPerfEventConfig returns the default perf event configuration. It relies on the map root to be set.

type PerfEventHeader 

type PerfEventHeader struct {
	Type      uint32
	Misc      uint16
	TotalSize uint16
}

PerfEventHeader must match 'struct perf_event_header in <linux/perf_event.h>.

type PerfEventLost 

type PerfEventLost struct {
	PerfEventHeader
	Id   uint64
	Lost uint64
}

PerfEventLost must match 'struct perf_event_lost in kernel sources.

type PerfEventMmapPage 

type PerfEventMmapPage struct {
	Version       uint32 // version number of this structure
	CompatVersion uint32 // lowest version this is compat with

	Lock        uint32 // seqlock for synchronization
	Index       uint32 // hardware event identifier
	Offset      int64  // add to hardware event value
	TimeEnabled uint64 // time event active
	TimeRunning uint64 // time event on cpu
	//union {
	Capabilities uint64

	//		cap_user_rdpmc		: 1, /* The RDPMC instruction can be used to read counts */
	//		cap_user_time		: 1, /* The time_* fields are used */
	//		cap_user_time_zero	: 1, /* The time_zero field is used */
	//		cap_____res		: 59;
	//};
	//};
	PmcWidth uint16

	TimeShift  uint16
	TimeMult   uint32
	TimeOffset uint64
	TimeZero   uint64
	Size       uint32

	Reserved [118*8 + 4]uint8 // align to 1k.

	DataHead   uint64 // head in the data section
	DataTail   uint64 // user-space written tail
	DataOffset uint64 // where the buffer starts
	DataSize   uint64 // data buffer size

	AuxHead   uint64
	AuxTail   uint64
	AuxOffset uint64
	AuxSize   uint64
}

PerfEventMmapPage reflects the Linux 'struct perf_event_mmap_page'

func (*PerfEventMmapPage) Decode 

func (p *PerfEventMmapPage) Decode(reader io.ReadSeeker) error

Decode populates 'p' base on the bytes read from the specified reader.

This function should not be used from performance-sensitive code.

type PerfEventSample 

type PerfEventSample struct {
	PerfEventHeader
	Size uint32
	// contains filtered or unexported fields
}

PerfEventSample must match 'struct perf_event_sample in kernel sources.

func (*PerfEventSample) DataCopy 

func (e *PerfEventSample) DataCopy() []byte

func (*PerfEventSample) DataDirect 

func (e *PerfEventSample) DataDirect() []byte

type ReadState 

type ReadState struct {
	Base     uint64 // Actually a pointer
	RawSize  uint64
	LastSize uint64
}

ReadState is a golang reflection of C.struct_read_state{}

func (*ReadState) Decode 

func (r *ReadState) Decode(reader io.ReadSeeker) error

Decode populates 'r' based on the bytes read from the specified reader.

This function should not be used from performance-sensitive code.

type ReceiveFunc 

type ReceiveFunc func(msg *PerfEventSample, cpu int)

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