can dynamically load progs and tracepoints

2 files changed, 57 insertions, 3 deletions

diff --git a/internal/tracepoints/syscalls.go b/internal/tracepoints/syscalls.go
index ebc46af..51f4d94 100644
--- a/internal/tracepoints/syscalls.go
+++ b/internal/tracepoints/syscalls.go
@@ -2,20 +2,74 @@ package tracepoints
 
 import (
 	"fmt"
+	"log"
+	"os"
+	"regexp"
+	"strings"
 
 	bpf "github.com/aquasecurity/libbpfgo"
 )
 
-func AttachSyscalls(bpfModule *bpf.Module, names ...string) error {
-	for _, name := range names {
+// SEC("tracepoint/syscalls/sys_exit_openat")
+var syscallRe = regexp.MustCompile(`sys_((enter|exit).*)"\)`)
+
+func filterLines(lines []string) ([]string, error) {
+	var syscalls []string
+
+	for _, line := range lines {
+		matches := syscallRe.FindStringSubmatch(line)
+		if len(matches) < 1 {
+			continue
+		}
+		syscalls = append(syscalls, matches[1])
+	}
+
+	return syscalls, nil
+}
+
+func usedSyscalls() ([]string, error) {
+	var syscalls []string
+
+	files, err := os.ReadDir(".")
+	if err != nil {
+		return syscalls, err
+	}
+
+	for _, file := range files {
+		fileName := file.Name()
+		if !strings.HasSuffix(fileName, ".bpf.c") {
+			continue
+		}
+		content, err := os.ReadFile(fileName)
+		if err != nil {
+			return syscalls, err
+		}
+		syscalls_, err := filterLines(strings.Split(string(content), "\n"))
+		if err != nil {
+			return syscalls, err
+		}
+		syscalls = append(syscalls, syscalls_...)
+	}
+
+	return syscalls, nil
+}
+
+func AttachSyscalls(bpfModule *bpf.Module) error {
+	syscalls, err := usedSyscalls()
+	if err != nil {
+		return err
+	}
+	for _, name := range syscalls {
 		// Attach to tracepoint
 		prog, err := bpfModule.GetProgram(fmt.Sprintf("handle_%s", name))
 		if err != nil {
 			return fmt.Errorf("Failed to get BPF program handle_%s: %v", name, err)
 		}
+		log.Println("Attached prog handle_" + name)
 		if _, err = prog.AttachTracepoint("syscalls", fmt.Sprintf("sys_%s", name)); err != nil {
 			return fmt.Errorf("Failed to attach to sys_%s tracepoint: %v", name, err)
 		}
+		log.Println("Attached tracepoint sys_" + name)
 	}
 	return nil
 }
diff --git a/main.go b/main.go
index 1d1a99c..0f8342a 100644
--- a/main.go
+++ b/main.go
@@ -64,7 +64,7 @@ func main() {
 		os.Exit(-1)
 	}
 
-	if err := tracepoints.AttachSyscalls(bpfModule, "enter_openat", "exit_openat"); err != nil {
+	if err := tracepoints.AttachSyscalls(bpfModule); err != nil {
 		fmt.Fprintf(os.Stderr, err.Error())
 		os.Exit(-1)
 	}