func Tracer() { p := new(oz.Profile) if err := json.NewDecoder(os.Stdin).Decode(&p); err != nil { log.Error("unable to decode profile data: %v", err) os.Exit(1) } var proc_attr syscall.ProcAttr var sys_attr syscall.SysProcAttr sys_attr.Ptrace = true done := false proc_attr.Sys = &sys_attr cmd := os.Args[1] cmdArgs := os.Args[2:] log.Info("Tracer running command (%v) arguments (%v)\n", cmd, cmdArgs) c := exec.Command(cmd) c.SysProcAttr = &syscall.SysProcAttr{Ptrace: true} c.Env = os.Environ() c.Args = append(c.Args, cmdArgs...) pi, err := c.StdinPipe() if err != nil { fmt.Errorf("error creating stdin pipe for tracer process: %v", err) os.Exit(1) } jdata, err := json.Marshal(p) if err != nil { fmt.Errorf("Unable to marshal seccomp state: %+v", err) os.Exit(1) } io.Copy(pi, bytes.NewBuffer(jdata)) log.Info(string(jdata)) pi.Close() children := make(map[int]bool) if err := c.Start(); err == nil { children[c.Process.Pid] = true var s syscall.WaitStatus pid, err := syscall.Wait4(-1, &s, syscall.WALL, nil) children[pid] = true if err != nil { log.Error("Error (wait4): %v", err) } log.Info("Tracing child pid: %v\n", pid) for done == false { syscall.PtraceSetOptions(pid, unix.PTRACE_O_TRACESECCOMP|unix.PTRACE_O_TRACEFORK|unix.PTRACE_O_TRACEVFORK|unix.PTRACE_O_TRACECLONE|unix.PTRACE_O_TRACEEXIT) syscall.PtraceCont(pid, 0) pid, err = syscall.Wait4(-1, &s, syscall.WALL, nil) if err != nil { log.Error("Error (wait4): %v\n", err) if len(children) == 0 { done = true } continue } children[pid] = true if s.Exited() == true { delete(children, pid) log.Info("Child pid %v finished.\n", pid) if len(children) == 0 { done = true } continue } if uint32(s)>>8 == (uint32(unix.SIGTRAP) | (unix.PTRACE_EVENT_SECCOMP << 8)) { if err != nil { log.Error("Error (ptrace): %v", err) continue } var regs syscall.PtraceRegs err = syscall.PtraceGetRegs(pid, ®s) if err != nil { log.Error("Error (ptrace): %v", err) } systemcall, err := syscallByNum(int(regs.Orig_rax)) if err != nil { log.Error("Error: %v", err) continue } var callrep string = fmt.Sprintf("%s(", systemcall.name) var reg uint64 = 0 for arg := range systemcall.args { if systemcall.args[arg] == 0 { break } if arg > 0 { callrep += fmt.Sprintf(",") } switch arg { case 0: reg = regs.Rdi case 1: reg = regs.Rsi case 2: reg = regs.Rdx case 3: reg = regs.Rcx case 4: reg = regs.R8 case 5: reg = regs.R9 } if systemcall.args[arg] == STRINGARG { str, err := readStringArg(pid, uintptr(reg)) if err != nil { log.Error("Error: %v", err) } else { callrep += fmt.Sprintf("\"%s\"", str) } } else if systemcall.args[arg] == INTARG { callrep += fmt.Sprintf("%d", uint64(reg)) } else { /* Stringify pointers in writes to stdout/stderr */ write, err := syscallByName("write") if err != nil { log.Error("Error: %v", err) } if systemcall.num == write.num && (regs.Rdi == uint64(syscall.Stdout) || regs.Rdi == uint64(syscall.Stderr)) { str, err := readStringArg(pid, uintptr(reg)) if err != nil { log.Error("Error %v", err) } else { if isPrintableASCII(str) == true { callrep += fmt.Sprintf("\"%s\"", str) } else { callrep += fmt.Sprintf("0x%X", uintptr(reg)) } } } else { callrep += fmt.Sprintf("0x%X", uintptr(reg)) } } } callrep += ")" log.Info("==============================================\nseccomp hit on sandbox pid %v (%v) syscall %v (%v): \n\n%s\nI ==============================================\n\n", pid, getProcessCmdLine(pid), systemcall.name, regs.Orig_rax, callrep) } } } else { log.Error("Error: %v", err) } }
func Tracer() { p := new(oz.Profile) if err := json.NewDecoder(os.Stdin).Decode(&p); err != nil { log.Error("unable to decode profile data: %v", err) os.Exit(1) } var proc_attr syscall.ProcAttr var sys_attr syscall.SysProcAttr sys_attr.Ptrace = true done := false proc_attr.Sys = &sys_attr cmd := os.Args[1] cmdArgs := os.Args[2:] log.Info("Tracer running command (%v) arguments (%v)\n", cmd, cmdArgs) c := exec.Command(cmd) c.SysProcAttr = &syscall.SysProcAttr{Ptrace: true} c.Env = os.Environ() c.Args = append(c.Args, cmdArgs...) pi, err := c.StdinPipe() if err != nil { fmt.Errorf("error creating stdin pipe for tracer process: %v", err) os.Exit(1) } jdata, err := json.Marshal(p) if err != nil { fmt.Errorf("Unable to marshal seccomp state: %+v", err) os.Exit(1) } io.Copy(pi, bytes.NewBuffer(jdata)) log.Info(string(jdata)) pi.Close() children := make(map[int]bool) renderFunctions := getRenderingFunctions() if err := c.Start(); err == nil { children[c.Process.Pid] = true var s syscall.WaitStatus pid, err := syscall.Wait4(-1, &s, syscall.WALL, nil) children[pid] = true if err != nil { log.Error("Error (wait4) here first: %v %i", err, pid) } log.Info("Tracing child pid: %v\n", pid) for done == false { syscall.PtraceSetOptions(pid, unix.PTRACE_O_TRACESECCOMP|unix.PTRACE_O_TRACEFORK|unix.PTRACE_O_TRACEVFORK|unix.PTRACE_O_TRACECLONE) syscall.PtraceCont(pid, 0) pid, err = syscall.Wait4(-1, &s, syscall.WALL, nil) if err != nil { log.Error("Error (wait4) here: %v %i %v\n", err, pid, children) if len(children) == 0 { done = true } continue } children[pid] = true if s.Exited() == true { delete(children, pid) log.Info("Child pid %v finished.\n", pid) if len(children) == 0 { done = true } continue } if s.Signaled() == true { log.Error("Other pid signalled %v %v", pid, s) delete(children, pid) continue } switch uint32(s) >> 8 { case uint32(unix.SIGTRAP) | (unix.PTRACE_EVENT_SECCOMP << 8): if err != nil { log.Error("Error (ptrace): %v", err) continue } var regs syscall.PtraceRegs err = syscall.PtraceGetRegs(pid, ®s) if err != nil { log.Error("Error (ptrace): %v", err) } systemcall, err := syscallByNum(getSyscallNumber(regs)) if err != nil { log.Error("Error: %v", err) continue } /* Render the system call invocation */ r := getSyscallRegisterArgs(regs) call := "" if f, ok := renderFunctions[getSyscallNumber(regs)]; ok { call, err = f(pid, r) if err != nil { log.Info("%v", err) continue } } else { call = renderSyscallBasic(pid, systemcall, regs) } log.Info("==============================================\nseccomp hit on sandbox pid %v (%v) syscall %v (%v):\n\n%s\nI ==============================================\n\n", pid, getProcessCmdLine(pid), systemcall.name, systemcall.num, call) continue case uint32(unix.SIGTRAP) | (unix.PTRACE_EVENT_EXIT << 8): log.Error("Ptrace exit event detected pid %v (%s)", pid, getProcessCmdLine(pid)) case uint32(unix.SIGTRAP) | (unix.PTRACE_EVENT_CLONE << 8): log.Error("Ptrace clone event detected pid %v (%s)", pid, getProcessCmdLine(pid)) continue case uint32(unix.SIGTRAP) | (unix.PTRACE_EVENT_FORK << 8): log.Error("PTrace fork event detected pid %v (%s)", pid, getProcessCmdLine(pid)) continue case uint32(unix.SIGTRAP) | (unix.PTRACE_EVENT_VFORK << 8): log.Error("Ptrace vfork event detected pid %v (%s)", pid, getProcessCmdLine(pid)) continue case uint32(unix.SIGTRAP) | (unix.PTRACE_EVENT_VFORK_DONE << 8): log.Error("Ptrace vfork done event detected pid %v (%s)", pid, getProcessCmdLine(pid)) continue case uint32(unix.SIGTRAP) | (unix.PTRACE_EVENT_EXEC << 8): log.Error("Ptrace exec event detected pid %v (%s)", pid, getProcessCmdLine(pid)) continue case uint32(unix.SIGTRAP) | (unix.PTRACE_EVENT_STOP << 8): log.Error("Ptrace stop event detected pid %v (%s)", pid, getProcessCmdLine(pid)) continue case uint32(unix.SIGTRAP): log.Error("SIGTRAP detected in pid %v (%s)", pid, getProcessCmdLine(pid)) continue case uint32(unix.SIGCHLD): log.Error("SIGCHLD detected pid %v (%s)", pid, getProcessCmdLine(pid)) continue case uint32(unix.SIGSTOP): log.Error("SIGSTOP detected pid %v (%s)", pid, getProcessCmdLine(pid)) continue default: y := s.StopSignal() log.Error("Child stopped for unknown reasons pid %v status %v signal %i (%s)", pid, s, y, getProcessCmdLine(pid)) continue } } } }