add support for iterator programs

Author: brycekahle

probe.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/cilium/ebpf"
+	"github.com/cilium/ebpf/link"
 	"github.com/vishvananda/netlink"
 	"golang.org/x/sys/unix"
 
@@ -576,6 +577,22 @@ func (p *Probe) attach() error {
 	return nil
 }
 
+func (p *Probe) Iterator() (io.ReadCloser, error) {
+	p.stateLock.RLock()
+	defer p.stateLock.RUnlock()
+	if p.state <= paused || !p.Enabled {
+		return nil, ErrManagerNotStarted
+	}
+	if p.programSpec.AttachType != ebpf.AttachTraceIter {
+		return nil, fmt.Errorf("invalid program attach type %s", p.programSpec.AttachType)
+	}
+	it, ok := p.progLink.(*link.Iter)
+	if !ok {
+		return nil, fmt.Errorf("invalid program attach type %T", p.progLink)
+	}
+	return it.Open()
+}
+
 // cleanupProgramSpec - Cleans up the internal ProgramSpec attribute to free up some memory
 func (p *Probe) cleanupProgramSpec() {
 	if p.KeepProgramSpec {

tracing.go

@@ -3,15 +3,22 @@ package manager
 import (
 	"fmt"
 
+	"github.com/cilium/ebpf"
 	"github.com/cilium/ebpf/link"
 )
 
 func (p *Probe) attachTracing() error {
 	var err error
-	p.progLink, err = link.AttachTracing(link.TracingOptions{
-		Program:    p.program,
-		AttachType: p.programSpec.AttachType,
-	})
+	if p.programSpec.AttachType == ebpf.AttachTraceIter {
+		p.progLink, err = link.AttachIter(link.IterOptions{
+			Program: p.program,
+		})
+	} else {
+		p.progLink, err = link.AttachTracing(link.TracingOptions{
+			Program:    p.program,
+			AttachType: p.programSpec.AttachType,
+		})
+	}
 	if err != nil {
 		return fmt.Errorf("link tracing: %w", err)
 	}