add-bpf-capability (#1)

1) add-bpf-capability
2) Not so clean but for now it's okay to start with

Co-authored-by: Harshavardhan Musanalli <harshavmb@gmail.com>
Reviewed-on: #1

main.go

@@ -5,10 +5,107 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"os/exec"
+	"strconv"
 	"strings"
+	"syscall"
 )
 
+// checkRootPrivileges ensures the program is running as root
+func checkRootPrivileges() {
+	if os.Geteuid() != 0 {
+		fmt.Fprintf(os.Stderr, "❌ ERROR: This program must be run as root for eBPF functionality.\n")
+		fmt.Fprintf(os.Stderr, "Please run with: sudo %s\n", os.Args[0])
+		fmt.Fprintf(os.Stderr, "Reason: eBPF programs require root privileges to:\n")
+		fmt.Fprintf(os.Stderr, "  - Load programs into the kernel\n")
+		fmt.Fprintf(os.Stderr, "  - Attach to kernel functions and tracepoints\n")
+		fmt.Fprintf(os.Stderr, "  - Access kernel memory maps\n")
+		os.Exit(1)
+	}
+}
+
+// checkKernelVersionCompatibility ensures kernel version is 4.4 or higher
+func checkKernelVersionCompatibility() {
+	output, err := exec.Command("uname", "-r").Output()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "❌ ERROR: Cannot determine kernel version: %v\n", err)
+		os.Exit(1)
+	}
+
+	kernelVersion := strings.TrimSpace(string(output))
+
+	// Parse version (e.g., "5.15.0-56-generic" -> major=5, minor=15)
+	parts := strings.Split(kernelVersion, ".")
+	if len(parts) < 2 {
+		fmt.Fprintf(os.Stderr, "❌ ERROR: Cannot parse kernel version: %s\n", kernelVersion)
+		os.Exit(1)
+	}
+
+	major, err := strconv.Atoi(parts[0])
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "❌ ERROR: Cannot parse major kernel version: %s\n", parts[0])
+		os.Exit(1)
+	}
+
+	minor, err := strconv.Atoi(parts[1])
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "❌ ERROR: Cannot parse minor kernel version: %s\n", parts[1])
+		os.Exit(1)
+	}
+
+	// Check if kernel is 4.4 or higher
+	if major < 4 || (major == 4 && minor < 4) {
+		fmt.Fprintf(os.Stderr, "❌ ERROR: Kernel version %s is too old for eBPF.\n", kernelVersion)
+		fmt.Fprintf(os.Stderr, "Required: Linux kernel 4.4 or higher\n")
+		fmt.Fprintf(os.Stderr, "Current: %s\n", kernelVersion)
+		fmt.Fprintf(os.Stderr, "Reason: eBPF requires kernel features introduced in 4.4+:\n")
+		fmt.Fprintf(os.Stderr, "  - BPF system call support\n")
+		fmt.Fprintf(os.Stderr, "  - eBPF program types (kprobe, tracepoint)\n")
+		fmt.Fprintf(os.Stderr, "  - BPF maps and helper functions\n")
+		os.Exit(1)
+	}
+
+	fmt.Printf("✅ Kernel version %s is compatible with eBPF\n", kernelVersion)
+}
+
+// checkEBPFSupport validates eBPF subsystem availability
+func checkEBPFSupport() {
+	// Check if /sys/kernel/debug/tracing exists (debugfs mounted)
+	if _, err := os.Stat("/sys/kernel/debug/tracing"); os.IsNotExist(err) {
+		fmt.Fprintf(os.Stderr, "⚠️  WARNING: debugfs not mounted. Some eBPF features may not work.\n")
+		fmt.Fprintf(os.Stderr, "To fix: sudo mount -t debugfs debugfs /sys/kernel/debug\n")
+	}
+
+	// Check if we can access BPF syscall
+	fd, _, errno := syscall.Syscall(321, 0, 0, 0) // BPF syscall number on x86_64
+	if errno != 0 && errno != syscall.EINVAL {
+		fmt.Fprintf(os.Stderr, "❌ ERROR: BPF syscall not available (errno: %v)\n", errno)
+		fmt.Fprintf(os.Stderr, "This may indicate:\n")
+		fmt.Fprintf(os.Stderr, "  - Kernel compiled without BPF support\n")
+		fmt.Fprintf(os.Stderr, "  - BPF syscall disabled in kernel config\n")
+		os.Exit(1)
+	}
+	if fd > 0 {
+		syscall.Close(int(fd))
+	}
+
+	fmt.Printf("✅ eBPF syscall is available\n")
+}
+
 func main() {
+	fmt.Println("🔍 Linux eBPF-Enhanced Diagnostic Agent")
+	fmt.Println("=======================================")
+
+	// Perform system compatibility checks
+	fmt.Println("Performing system compatibility checks...")
+
+	checkRootPrivileges()
+	checkKernelVersionCompatibility()
+	checkEBPFSupport()
+
+	fmt.Println("✅ All system checks passed")
+	fmt.Println("")
+
 	// Initialize the agent
 	agent := NewLinuxDiagnosticAgent()
 
@@ -32,8 +129,8 @@ func main() {
 			continue
 		}
 
-		// Process the issue
-		if err := agent.DiagnoseIssue(input); err != nil {
+		// Process the issue with eBPF capabilities
+		if err := agent.DiagnoseWithEBPF(input); err != nil {
 			fmt.Printf("Error: %v\n", err)
 		}
 	}