Documentation
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Overview ¶
Package event provides access to system-level event file descriptors that act as semaphores and notification mechanism to facilitate AF_PACKET network traffic capture. This is achieved either via conventional recvfrom() operations (per-packet retrieval in afpacket/afpacket) or via PPOLL and the kernel ring buffer (per-block retrieval in afpacket/afring). In the latter case, a highly optimized assembler implementation is used (for AMD64 / ARM64 architectures) in order to maximize throughput (by releasing resources as early as possible for the next poll operation).
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( // SignalUnblock ends any ongoing PPOLL syscall (similar to a timeout) SignalUnblock = EvtData{1, 0, 0, 0, 0, 0, 0, 0} // SignalStop causes the capture to stop SignalStop = EvtData{0, 0, 0, 0, 0, 0, 0, 1} )
Functions ¶
This section is empty.
Types ¶
type EvtFileDescriptor ¶
type EvtFileDescriptor int
EvtFileDescriptor denotes a system-level event file descriptor
func New ¶
func New() (EvtFileDescriptor, error)
New instantiates a new non-blocking event file descriptor
func (EvtFileDescriptor) ReadEvent ¶
func (e EvtFileDescriptor) ReadEvent() (EvtData, error)
ReadEvent reads the event data from the event file descriptor
func (EvtFileDescriptor) Signal ¶
func (e EvtFileDescriptor) Signal(data EvtData) error
Signal sends an event via the event file descriptor
type Handler ¶
type Handler struct {
// Efd denotes the event file descriptor of this handler
Efd EvtFileDescriptor
// Fd denotes the socket file descriptor of this handler
Fd socket.FileDescriptor
// contains filtered or unexported fields
}
Handler wraps a socket file descriptor and an event file descriptor in a single instance. In addition, a (unexported) mock file descriptor allows for mocking the entire handler without having to manipulate / distinguish from the caller side
func NewMockHandler ¶
func NewMockHandler() (*Handler, *socket.MockFileDescriptor, error)
NewMockHandler instantiates a new mock Handler (wrapping a regular one)
func (*Handler) GetSocketStats ¶
func (p *Handler) GetSocketStats() (socket.TPacketStats, error)
GetSocketStats returns (and resets) socket / traffic statistics
type MockHandler ¶
type MockHandler Handler
MockHandler wraps a regular Handler to allow defining new methods on top of it to facilitate mocking without having to rely on interfaces (and actually provide mocking as close to the original implementation as possible)
func ToMockHandler ¶
func ToMockHandler(h *Handler) *MockHandler
ToMockHandler converts an existing Handler pointer variable to an equivalent MockHandler
func (*MockHandler) HasPackets ¶
func (m *MockHandler) HasPackets() bool
HasPackets returns if there are packets in the underlying mock socket
func (*MockHandler) SignalAvailableData ¶
func (m *MockHandler) SignalAvailableData() error
SignalAvailableData sets the semaphore of the underlying event file descriptor, indicating that data is available (and releasing the block)
Source Files