Add selftest for setting attachments

Signed-off-by: grantseltzer <grantseltzer@gmail.com>

selftest/set-attach/Makefile

@@ -0,0 +1 @@
+../common/Makefile

selftest/set-attach/go.mod

@@ -0,0 +1,7 @@
+module github.com/aquasecurity/libbpfgo/selftest/perfbuffers
+
+go 1.16
+
+require github.com/aquasecurity/libbpfgo v0.2.1-libbpf-0.4.0
+
+replace github.com/aquasecurity/libbpfgo => ../../

selftest/set-attach/go.sum

@@ -0,0 +1,11 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/sys v0.0.0-20210514084401-e8d321eab015/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

selftest/set-attach/main.bpf.c

@@ -0,0 +1,32 @@
+//+build ignore
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#ifdef asm_inline
+#undef asm_inline
+#define asm_inline asm
+#endif
+
+struct {
+    __uint(type, BPF_MAP_TYPE_RINGBUF);
+    __uint(max_entries, 1 << 24);
+} events SEC(".maps");
+long ringbuffer_flags = 0;
+
+SEC("fentry/FUNC")
+int BPF_PROG(foobar)
+{
+    int *process;
+    // Reserve space on the ringbuffer for the sample
+    process = bpf_ringbuf_reserve(&events, sizeof(int), ringbuffer_flags);
+    if (!process) {
+        return 0;
+    }
+    *process = 2021;
+    bpf_ringbuf_submit(process, ringbuffer_flags);
+    return 0;
+}
+
+char LICENSE[] SEC("license") = "GPL";
+

selftest/set-attach/main.go

@@ -0,0 +1,80 @@
+package main
+
+import "C"
+
+import (
+	"encoding/binary"
+	"os"
+	"syscall"
+	"time"
+
+	"fmt"
+
+	bpf "github.com/aquasecurity/libbpfgo"
+)
+
+func main() {
+
+	bpfModule, err := bpf.NewModuleFromFile("main.bpf.o")
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(-1)
+	}
+	defer bpfModule.Close()
+
+	bpfModule.ListProgramNames()
+
+	prog, err := bpfModule.GetProgram("foobar")
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(-1)
+	}
+
+	prog.SetProgramType(bpf.BPFProgTypeTracing)
+	prog.SetAttachType(bpf.BPFAttachTypeTraceFentry)
+	err = prog.SetAttachTarget(0, "__x64_sys_mmap")
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(-1)
+	}
+	err = bpfModule.BPFLoadObject()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(-1)
+	}
+	_, err = prog.AttachGeneric()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(-1)
+	}
+
+	eventsChannel := make(chan []byte)
+	rb, err := bpfModule.InitRingBuf("events", eventsChannel)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(-1)
+	}
+
+	rb.Start()
+	numberOfEventsReceived := 0
+	go func() {
+		for {
+			syscall.Mmap(999, 999, 999, 1, 1)
+			time.Sleep(time.Second / 100)
+		}
+	}()
+recvLoop:
+	for {
+		b := <-eventsChannel
+		if binary.LittleEndian.Uint32(b) != 2021 {
+			fmt.Fprintf(os.Stderr, "invalid data retrieved\n")
+			os.Exit(-1)
+		}
+		numberOfEventsReceived++
+		if numberOfEventsReceived > 5 {
+			break recvLoop
+		}
+	}
+	rb.Stop()
+	rb.Close()
+}

selftest/set-attach/run.sh

@@ -0,0 +1 @@
+../common/run-5.8.sh

selftest/tracing/main.bpf.c

@@ -38,6 +38,5 @@ int BPF_PROG(commit_creds, struct cred *foobar)
     return 0;
 }
 
-
 char LICENSE[] SEC("license") = "GPL";
 

selftest/tracing/main.go

@@ -70,7 +70,7 @@ func main() {
 	go func() {
 		for {
 			syscall.Mmap(999, 999, 999, 1, 1)
-			time.Sleep(time.Second / 2)
+			time.Sleep(time.Second / 100)
 		}
 	}()
 recvLoop:
@@ -85,4 +85,7 @@ recvLoop:
 			break recvLoop
 		}
 	}
+
+	rb.Stop()
+	rb.Close()
 }