Feature/queuestack

bcc/queuestack.go

@@ -0,0 +1,115 @@
+package bcc
+
+/*
+#cgo CFLAGS: -I/usr/include/bcc/compat
+#cgo LDFLAGS: -lbcc
+#include <linux/bpf.h>
+#include <bcc/bcc_common.h>
+#include <bcc/libbpf.h>
+*/
+import "C"
+import (
+	"fmt"
+	"unsafe"
+)
+
+// IsQueueStack determines if Table can be used as QueueStack
+func IsQueueStack(table *Table) bool {
+	ttype := C.bpf_table_type_id(table.module.p, table.id)
+	return ttype == C.BPF_MAP_TYPE_QUEUE || ttype == C.BPF_MAP_TYPE_STACK
+}
+
+// QueueStack wraps Table pointer with queue & stack specific methods
+type QueueStack struct {
+	*Table
+}
+
+// NewQueueStack creates a QueueStack wrapper
+func NewQueueStack(table *Table) *QueueStack {
+	return &QueueStack{Table: table}
+}
+
+// Push pushes a new element to a BPF queue or stack.
+// See https://github.com/iovisor/bcc/blob/master/docs/reference_guide.md#28-mappush for flags reference
+func (queue *QueueStack) Push(leaf []byte, flags int) error {
+	fd := C.bpf_table_fd_id(queue.Table.module.p, queue.Table.id)
+
+	leafP := unsafe.Pointer(&leaf[0])
+
+	r, err := C.bpf_update_elem(fd, nil, leafP, C.ulonglong(flags))
+	if r != 0 {
+		leafStr, errL := queue.Table.LeafBytesToStr(leaf)
+		if errL != nil {
+			leafStr = fmt.Sprintf("%v", leaf)
+		}
+
+		return fmt.Errorf("QueueStack.Push: %v: %v", leafStr, err)
+	}
+	return nil
+}
+
+// Pop pops an element from a BPF queue or stack and returns it as a byte array.
+// See https://github.com/iovisor/bcc/blob/master/docs/reference_guide.md#29-mappop for flags reference
+func (queue *QueueStack) Pop() ([]byte, error) {
+	fd := C.bpf_table_fd_id(queue.Table.module.p, queue.Table.id)
+
+	leafSize := C.bpf_table_leaf_size_id(queue.Table.module.p, queue.Table.id)
+
+	leaf := make([]byte, leafSize)
+	leafP := unsafe.Pointer(&leaf[0])
+
+	r, err := C.bpf_lookup_and_delete(fd, nil, leafP)
+	if r != 0 {
+		return nil, fmt.Errorf("QueueStack.Pop: %v", err)
+	}
+	return leaf, nil
+}
+
+// PopP pops an element from a BPF queue or stack and returns it as a unsafe.Pointer.
+// See https://github.com/iovisor/bcc/blob/master/docs/reference_guide.md#29-mappop for flags reference
+func (queue *QueueStack) PopP() (unsafe.Pointer, error) {
+	fd := C.bpf_table_fd_id(queue.Table.module.p, queue.Table.id)
+
+	leafSize := C.bpf_table_leaf_size_id(queue.Table.module.p, queue.Table.id)
+
+	leaf := make([]byte, leafSize)
+	leafP := unsafe.Pointer(&leaf[0])
+
+	r, err := C.bpf_lookup_and_delete(fd, nil, leafP)
+	if r != 0 {
+		return nil, fmt.Errorf("QueueStack.PopP: %v", err)
+	}
+	return leafP, nil
+}
+
+// Peek peeks an element from a BPF queue or stack and returns it as a byte array.
+func (queue *QueueStack) Peek() ([]byte, error) {
+	fd := C.bpf_table_fd_id(queue.Table.module.p, queue.Table.id)
+
+	leafSize := C.bpf_table_leaf_size_id(queue.Table.module.p, queue.Table.id)
+
+	leaf := make([]byte, leafSize)
+	leafP := unsafe.Pointer(&leaf[0])
+
+	r, err := C.bpf_lookup_elem(fd, nil, leafP)
+	if r != 0 {
+		return nil, fmt.Errorf("QueueStack.Peek: %v", err)
+	}
+	return leaf, nil
+}
+
+// PeekP peeks an element from a BPF queue or stack and returns it as an unsafe pointer.
+func (queue *QueueStack) PeekP() (unsafe.Pointer, error) {
+	fd := C.bpf_table_fd_id(queue.Table.module.p, queue.Table.id)
+
+	leafSize := C.bpf_table_leaf_size_id(queue.Table.module.p, queue.Table.id)
+
+	leaf := make([]byte, leafSize)
+	leafP := unsafe.Pointer(&leaf[0])
+
+	r, err := C.bpf_lookup_elem(fd, nil, leafP)
+	if r != 0 {
+		return nil, fmt.Errorf("QueueStack.Peek: %v", err)
+	}
+	return leafP, nil
+}

bcc/table.go

@@ -299,6 +299,9 @@ func (it *TableIterator) Next() bool {
 
 	if it.key == nil {
 		keySize := C.bpf_table_key_size_id(it.table.module.p, it.table.id)
+		if keySize == 0 {
+			return false
+		}
 
 		key := make([]byte, keySize)
 		keyP := unsafe.Pointer(&key[0])