feature: Add AttachProgs/DetachProgs api for bpf object

Add AttachProgs/DetachProgs api for bpf object like api in libbpf:
bpf_object__attach_skeleton/bpf_object__detach_skeleton.
So we don't need to specify the program name to attach one by one.

Signed-off-by: Tao Chen <chen.dylane@gmail.com>

module.go

@@ -391,3 +391,33 @@ func (m *Module) Iterator() *BPFObjectIterator {
 		prevMap:  nil,
 	}
 }
+
+func (m *Module) AttachProgs() error {
+	iters := m.Iterator()
+	for {
+		prog := iters.NextProgram()
+		if prog == nil {
+			break
+		}
+		link, err := prog.AttachGeneric()
+		if err != nil {
+			return err
+		}
+		m.links = append(m.links, link)
+	}
+
+	return nil
+}
+
+func (m *Module) DetachProgs() error {
+	for _, link := range m.links {
+		if link.link != nil {
+			err := link.Destroy()
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}

selftest/module-attach-detach/Makefile

@@ -0,0 +1,87 @@
+BASEDIR = $(abspath ../../)
+
+OUTPUT = ../../output
+
+LIBBPF_SRC = $(abspath ../../libbpf/src)
+LIBBPF_OBJ = $(abspath $(OUTPUT)/libbpf.a)
+
+CLANG = clang
+CC = $(CLANG)
+GO = go
+
+ARCH := $(shell uname -m | sed 's/x86_64/amd64/g; s/aarch64/arm64/g')
+
+CFLAGS = -g -O2 -Wall -fpie -I$(abspath ../common)
+LDFLAGS =
+
+CGO_CFLAGS_STATIC = "-I$(abspath $(OUTPUT)) -I$(abspath ../common)"
+CGO_LDFLAGS_STATIC = "-lelf -lz $(LIBBPF_OBJ)"
+CGO_EXTLDFLAGS_STATIC = '-w -extldflags "-static"'
+
+CGO_CFLAGS_DYN = "-I. -I/usr/include/"
+CGO_LDFLAGS_DYN = "-lelf -lz -lbpf"
+
+MAIN = main
+
+.PHONY: $(MAIN)
+.PHONY: $(MAIN).go
+.PHONY: $(MAIN).bpf.c
+
+all: $(MAIN)-static
+
+.PHONY: libbpfgo
+.PHONY: libbpfgo-static
+.PHONY: libbpfgo-dynamic
+
+## libbpfgo
+
+libbpfgo-static:
+	$(MAKE) -C $(BASEDIR) libbpfgo-static
+
+libbpfgo-dynamic:
+	$(MAKE) -C $(BASEDIR) libbpfgo-dynamic
+
+outputdir:
+	$(MAKE) -C $(BASEDIR) outputdir
+
+## test bpf dependency
+
+$(MAIN).bpf.o: $(MAIN).bpf.c
+	$(CLANG) $(CFLAGS) -target bpf -D__TARGET_ARCH_$(ARCH) -I$(OUTPUT) -I$(abspath ../common) -c $< -o $@
+
+## test
+
+.PHONY: $(MAIN)-static
+.PHONY: $(MAIN)-dynamic
+
+$(MAIN)-static: libbpfgo-static | $(MAIN).bpf.o
+	CC=$(CLANG) \
+		CGO_CFLAGS=$(CGO_CFLAGS_STATIC) \
+		CGO_LDFLAGS=$(CGO_LDFLAGS_STATIC) \
+		GOOS=linux GOARCH=$(ARCH) \
+		$(GO) build \
+		-tags netgo -ldflags $(CGO_EXTLDFLAGS_STATIC) \
+		-o $(MAIN)-static ./$(MAIN).go
+
+$(MAIN)-dynamic: libbpfgo-dynamic | $(MAIN).bpf.o
+	CC=$(CLANG) \
+		CGO_CFLAGS=$(CGO_CFLAGS_DYN) \
+		CGO_LDFLAGS=$(CGO_LDFLAGS_DYN) \
+		$(GO) build -o ./$(MAIN)-dynamic ./$(MAIN).go
+
+## run
+
+.PHONY: run
+.PHONY: run-static
+.PHONY: run-dynamic
+
+run: run-static
+
+run-static: $(MAIN)-static
+	sudo ./run.sh $(MAIN)-static
+
+run-dynamic: $(MAIN)-dynamic
+	sudo ./run.sh $(MAIN)-dynamic
+
+clean:
+	rm -f *.o *-static *-dynamic

selftest/module-attach-detach/go.mod

@@ -0,0 +1,14 @@
+module github.com/aquasecurity/libbpfgo/selftest/module-attach-detach
+
+go 1.18
+
+require (
+	github.com/aquasecurity/libbpfgo v0.4.7-libbpf-1.2.0-b2e29a1
+	github.com/aquasecurity/libbpfgo/helpers v0.4.5
+)
+
+require golang.org/x/sys v0.7.0 // indirect
+
+replace github.com/aquasecurity/libbpfgo => ../../
+
+replace github.com/aquasecurity/libbpfgo/helpers => ../../helpers

selftest/module-attach-detach/go.sum

@@ -0,0 +1,6 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/stretchr/testify v1.8.2 h1:+h33VjcLVPDHtOdpUCuF+7gSuG3yGIftsP1YvFihtJ8=
+golang.org/x/sys v0.7.0 h1:3jlCCIQZPdOYu1h8BkNvLz8Kgwtae2cagcG/VamtZRU=
+golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

selftest/module-attach-detach/main.bpf.c

@@ -0,0 +1,58 @@
+//+build ignore
+
+#include <vmlinux.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct {
+    __uint(type, BPF_MAP_TYPE_RINGBUF);
+    __uint(max_entries, 1 << 24);
+} events SEC(".maps");
+long ringbuffer_flags = 0;
+
+#ifdef __TARGET_ARCH_amd64
+SEC("fentry/__x64_sys_mmap")
+#elif defined(__TARGET_ARCH_arm64)
+SEC("fentry/__arm64_sys_mmap")
+#endif
+int kprobe__sys_mmap(struct pt_regs *ctx)
+{
+    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;
+}
+
+#ifdef __TARGET_ARCH_amd64
+SEC("kprobe/__x64_sys_open")
+#elif defined(__TARGET_ARCH_arm64)
+SEC("kprobe/__arm64_sys_open")
+#endif
+int kprobe__sys_open(struct pt_regs *ctx)
+{
+    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/module-attach-detach/main.go

@@ -0,0 +1,85 @@
+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()
+
+	err = bpfModule.BPFLoadObject()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(-1)
+	}
+
+	err = bpfModule.AttachProgs()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, fmt.Sprintf("attach progs failed:%w", err))
+		os.Exit(-1)
+	}
+
+	err = bpfModule.DetachProgs()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, fmt.Sprintf("detach progs failed:%w", err))
+		os.Exit(-1)
+	}
+
+	// attach again
+	err = bpfModule.AttachProgs()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, fmt.Sprintf("attach progs failed:%w", 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.Poll(300)
+	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
+		}
+	}
+
+	err = bpfModule.DetachProgs()
+	if err != nil {
+		fmt.Fprintln(os.Stderr, fmt.Sprintf("detach progs failed:%w", err))
+		os.Exit(-1)
+	}
+
+	rb.Stop()
+	rb.Close()
+}

selftest/module-attach-detach/run.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+# SETTINGS
+
+TEST=$(dirname $0)/$1  # execute
+TIMEOUT=10             # seconds
+
+# COMMON
+
+COMMON="$(dirname $0)/../common/common.sh"
+[[ -f $COMMON ]] && { . $COMMON; } || { error "no common"; exit 1; }
+
+# MAIN
+
+kern_version ge 5.8
+
+check_build
+check_ppid
+test_exec
+test_finish
+
+exit 0