Documentation
¶
Overview ¶
Package capture provides utilities for reading packets from network interfaces or files.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( // ErrNoSource is returned when neither a network interface nor a file // is specified to New. ErrNoSource = errors.New("must specify a network interface or file") // ErrAmbiguousSource is returned when both a network interface and a file // are specified to New. ErrAmbiguousSource = errors.New("cannot specify both network interface and file") )
var ( // ErrBytesFull is returned if the buffer cannot hold enough // data bytes to store this block. ErrBytesFull = errors.New("buffer out of space for more bytes") // ErrBlocksFull is returned if the buffer cannot hold another block. ErrBlocksFull = errors.New("buffer out of space for more packets") )
Functions ¶
This section is empty.
Types ¶
type BlockBuffer ¶
type BlockBuffer struct {
// contains filtered or unexported fields
}
BlockBuffer stores a sequence of byte slices in compact form.
func NewBlockBuffer ¶
func NewBlockBuffer(maxBlocks, maxBytes int) BlockBuffer
NewBlockBuffer creates a new BlockBuffer that can hold a maximum of maxBlocks slices or a total of at most maxBytes.
func (*BlockBuffer) Append ¶
func (b *BlockBuffer) Append(data []byte) error
Append adds data to the buffer as a new block. Makes a copy of data, which may be modified freely after Append returns. Returns ErrBytesFull or ErrBlocksFull if there is insufficient space.
func (*BlockBuffer) Block ¶
func (b *BlockBuffer) Block(n int) []byte
Block returns a slice referencing block n, indexed from 0. Any modifications to the returned slice modify the contents of the buffer.
func (*BlockBuffer) BlockLen ¶
func (b *BlockBuffer) BlockLen() int
BlockLen returns the number of blocks currently stored in the buffer.
func (*BlockBuffer) BytesRemaining ¶
func (b *BlockBuffer) BytesRemaining() int
BytesRemaining returns the number of additional bytes this buffer can hold.
type PacketBuffer ¶
type PacketBuffer struct {
BlockBuffer
// contains filtered or unexported fields
}
PacketBuffer stores captured packets in a compact format.
func NewPacketBuffer ¶
func NewPacketBuffer(maxPackets, maxBytes int) *PacketBuffer
NewPacketBuffer creates a PacketBuffer with the specified limits.
func (*PacketBuffer) Append ¶
func (pb *PacketBuffer) Append(pd PacketData) error
Append adds a packet to the PacketBuffer. Makes a copy of pd.Data, which may be modified after Append returns. Returns ErrBytesFull or ErrBlocksFull if there is insufficient space.
func (*PacketBuffer) Packet ¶
func (pb *PacketBuffer) Packet(n int) PacketData
Packet returns the packet at the specified index, which must be less than PacketLen. The Data field of the returned PacketData points into this PacketBuffer and must not be modified.
func (*PacketBuffer) PacketCap ¶
func (pb *PacketBuffer) PacketCap() int
PacketCap returns the capacity for packets in the PacketBuffer.
func (*PacketBuffer) PacketLen ¶
func (pb *PacketBuffer) PacketLen() int
PacketLen returns the number of packets in the PacketBuffer.
type PacketData ¶
type PacketData struct {
Info gopacket.CaptureInfo
Data []byte
}
PacketData represents a single packet's data plus metadata indicating when the packet was captured.
type PacketSource ¶
type PacketSource interface {
// CollectPackets fills pb with packets.
CollectPackets(pb *PacketBuffer) error
// DiscardPacket reads a single packet and discards its contents.
DiscardPacket() error
StatProvider
}
PacketSource is an abstract source of network packets.
func New ¶
func New(netInterface string, infile string, bufferSize int, noDelay bool, ports []int) (PacketSource, error)
New creates a PacketSource bound to the specified network interface or pcap file.
bufferSize determines the amount of kernel memory (in MiB) to allocate for temporary storage. A larger bufferSize can reduce dropped packets as revealed by Stats, but use caution as kernel memory is a precious resource.
type StatProvider ¶
type StatProvider interface {
// Stats returns statistics compatible with those from a pcap handle.
Stats() (*pcap.Stats, error)
}
StatProvider provides statistics on packet capture.
Source Files