1 files changed, 158 insertions, 0 deletions
diff --git a/vendor/github.com/google/gopacket/afpacket/header.go b/vendor/github.com/google/gopacket/afpacket/header.go
new file mode 100644
index 0000000..0b9918e
--- /dev/null
+++ b/vendor/github.com/google/gopacket/afpacket/header.go
@@ -0,0 +1,158 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+// +build linux
+
+package afpacket
+
+import (
+	"reflect"
+	"time"
+	"unsafe"
+)
+
+// #include <linux/if_packet.h>
+import "C"
+
+// Our model of handling all TPacket versions is a little hacky, to say the
+// least.  We use the header interface to handle interactions with the
+// tpacket1/tpacket2 packet header AND the tpacket3 block header.  The big
+// difference is that tpacket3's block header implements the next() call to get
+// the next packet within the block, while v1/v2 just always return false.
+
+type header interface {
+	// getStatus returns the TPacket status of the current header.
+	getStatus() int
+	// clearStatus clears the status of the current header, releasing its
+	// underlying data back to the kernel for future use with new packets.
+	// Using the header after calling clearStatus is an error.  clearStatus
+	// should only be called after next() returns false.
+	clearStatus()
+	// getTime returns the timestamp for the current packet pointed to by
+	// the header.
+	getTime() time.Time
+	// getData returns the packet data pointed to by the current header.
+	getData() []byte
+	// getLength returns the total length of the packet.
+	getLength() int
+	// getIfaceIndex returns the index of the network interface
+	// where the packet was seen. The index can later be translated to a name.
+	getIfaceIndex() int
+	// next moves this header to point to the next packet it contains,
+	// returning true on success (in which case getTime and getData will
+	// return values for the new packet) or false if there are no more
+	// packets (in which case clearStatus should be called).
+	next() bool
+}
+
+func tpAlign(x int) int {
+	return int((uint(x) + tpacketAlignment - 1) &^ (tpacketAlignment - 1))
+}
+
+type v1header C.struct_tpacket_hdr
+type v2header C.struct_tpacket2_hdr
+
+func makeSlice(start uintptr, length int) (data []byte) {
+	slice := (*reflect.SliceHeader)(unsafe.Pointer(&data))
+	slice.Data = start
+	slice.Len = length
+	slice.Cap = length
+	return
+}
+
+func (h *v1header) getStatus() int {
+	return int(h.tp_status)
+}
+func (h *v1header) clearStatus() {
+	h.tp_status = 0
+}
+func (h *v1header) getTime() time.Time {
+	return time.Unix(int64(h.tp_sec), int64(h.tp_usec)*1000)
+}
+func (h *v1header) getData() []byte {
+	return makeSlice(uintptr(unsafe.Pointer(h))+uintptr(h.tp_mac), int(h.tp_snaplen))
+}
+func (h *v1header) getLength() int {
+	return int(h.tp_len)
+}
+func (h *v1header) getIfaceIndex() int {
+	ll := (*C.struct_sockaddr_ll)(unsafe.Pointer(uintptr(unsafe.Pointer(h)) + uintptr(tpAlign(int(C.sizeof_struct_tpacket_hdr)))))
+	return int(ll.sll_ifindex)
+}
+func (h *v1header) next() bool {
+	return false
+}
+
+func (h *v2header) getStatus() int {
+	return int(h.tp_status)
+}
+func (h *v2header) clearStatus() {
+	h.tp_status = 0
+}
+func (h *v2header) getTime() time.Time {
+	return time.Unix(int64(h.tp_sec), int64(h.tp_nsec))
+}
+func (h *v2header) getData() []byte {
+	return makeSlice(uintptr(unsafe.Pointer(h))+uintptr(h.tp_mac), int(h.tp_snaplen))
+}
+func (h *v2header) getLength() int {
+	return int(h.tp_len)
+}
+func (h *v2header) getIfaceIndex() int {
+	ll := (*C.struct_sockaddr_ll)(unsafe.Pointer(uintptr(unsafe.Pointer(h)) + uintptr(tpAlign(int(C.sizeof_struct_tpacket2_hdr)))))
+	return int(ll.sll_ifindex)
+}
+func (h *v2header) next() bool {
+	return false
+}
+
+type v3wrapper struct {
+	block    *C.struct_tpacket_block_desc
+	blockhdr *C.struct_tpacket_hdr_v1
+	packet   *C.struct_tpacket3_hdr
+	used     C.__u32
+}
+
+func initV3Wrapper(block unsafe.Pointer) (w v3wrapper) {
+	w.block = (*C.struct_tpacket_block_desc)(block)
+	w.blockhdr = (*C.struct_tpacket_hdr_v1)(unsafe.Pointer(&w.block.hdr[0]))
+	w.packet = (*C.struct_tpacket3_hdr)(unsafe.Pointer(uintptr(block) + uintptr(w.blockhdr.offset_to_first_pkt)))
+	return
+}
+func (w *v3wrapper) getStatus() int {
+	return int(w.blockhdr.block_status)
+}
+func (w *v3wrapper) clearStatus() {
+	w.blockhdr.block_status = 0
+}
+func (w *v3wrapper) getTime() time.Time {
+	return time.Unix(int64(w.packet.tp_sec), int64(w.packet.tp_nsec))
+}
+func (w *v3wrapper) getData() []byte {
+	return makeSlice(uintptr(unsafe.Pointer(w.packet))+uintptr(w.packet.tp_mac), int(w.packet.tp_snaplen))
+}
+func (w *v3wrapper) getLength() int {
+	return int(w.packet.tp_len)
+}
+func (w *v3wrapper) getIfaceIndex() int {
+	ll := (*C.struct_sockaddr_ll)(unsafe.Pointer(uintptr(unsafe.Pointer(w.packet)) + uintptr(tpAlign(int(C.sizeof_struct_tpacket3_hdr)))))
+	return int(ll.sll_ifindex)
+}
+func (w *v3wrapper) next() bool {
+	w.used++
+	if w.used >= w.blockhdr.num_pkts {
+		return false
+	}
+
+	next := uintptr(unsafe.Pointer(w.packet))
+	if w.packet.tp_next_offset != 0 {
+		next += uintptr(w.packet.tp_next_offset)
+	} else {
+		next += uintptr(tpacketAlign(int(w.packet.tp_snaplen) + int(w.packet.tp_mac)))
+	}
+	w.packet = (*C.struct_tpacket3_hdr)(unsafe.Pointer(next))
+	return true
+}