execprog, stress, prog2c: unify flags to enable additional features

This change makes all syz-execprog, syz-prog2c and syz-stress accept
-enable and -disable flags to enable or disable additional features
(tun, net_dev, net_reset, cgroups and binfmt_misc) instead of having
a separate flag for each of them.

The default (without any flags) behavior isn't changed: syz-execprog
and syz-stress enabled all the features (provided the runtime supports
them) and syz-prog2c disables all of them.

4 files changed, 355 insertions, 168 deletions

diff --git a/pkg/csource/common.go b/pkg/csource/common.go
index 9de387952..a39d714e0 100644
--- a/pkg/csource/common.go
+++ b/pkg/csource/common.go
@@ -82,8 +82,9 @@ func defineList(p, mmapProg *prog.Prog, opts Options) (defines []string) {
 		"SYZ_FAULT_INJECTION":               opts.Fault,
 		"SYZ_TUN_ENABLE":                    opts.EnableTun,
 		"SYZ_ENABLE_CGROUPS":                opts.EnableCgroups,
-		"SYZ_ENABLE_NETDEV":                 opts.EnableNetdev,
-		"SYZ_RESET_NET_NAMESPACE":           opts.ResetNet,
+		"SYZ_ENABLE_NETDEV":                 opts.EnableNetDev,
+		"SYZ_RESET_NET_NAMESPACE":           opts.EnableNetReset,
+		"SYZ_ENABLE_BINFMT_MISC":            opts.EnableBinfmtMisc,
 		"SYZ_USE_TMP_DIR":                   opts.UseTmpDir,
 		"SYZ_HANDLE_SEGV":                   opts.HandleSegv,
 		"SYZ_REPRO":                         opts.Repro,
diff --git a/pkg/csource/generated.go b/pkg/csource/generated.go
index f58bf8e30..fbbd671bf 100644
--- a/pkg/csource/generated.go
+++ b/pkg/csource/generated.go
@@ -208,6 +208,7 @@ static int inject_fault(int nth)
 	return 0;
 }
 #endif
+
 #if SYZ_EXECUTOR
 static int fault_injected(int fail_fd)
 {
@@ -1051,7 +1052,7 @@ static int event_timedwait(event_t* ev, uint64 timeout)
 }
 #endif
 
-#if SYZ_EXECUTOR || SYZ_FAULT_INJECTION || SYZ_ENABLE_CGROUPS || SYZ_SANDBOX_NONE || \
+#if SYZ_EXECUTOR || SYZ_REPEAT || SYZ_TUN_ENABLE || SYZ_FAULT_INJECTION || SYZ_SANDBOX_NONE || \
     SYZ_SANDBOX_SETUID || SYZ_SANDBOX_NAMESPACE || SYZ_SANDBOX_ANDROID_UNTRUSTED_APP
 #include <errno.h>
 #include <fcntl.h>
@@ -3492,6 +3493,8 @@ static void reset_ebtables()
 static void checkpoint_net_namespace(void)
 {
 #if SYZ_EXECUTOR
+	if (!flag_enable_net_reset)
+		return;
 	if (flag_sandbox == sandbox_setuid)
 		return;
 #endif
@@ -3504,6 +3507,8 @@ static void checkpoint_net_namespace(void)
 static void reset_net_namespace(void)
 {
 #if SYZ_EXECUTOR
+	if (!flag_enable_net_reset)
+		return;
 	if (flag_sandbox == sandbox_setuid)
 		return;
 #endif
@@ -3514,7 +3519,7 @@ static void reset_net_namespace(void)
 }
 #endif
 
-#if SYZ_EXECUTOR || SYZ_ENABLE_CGROUPS
+#if SYZ_EXECUTOR || (SYZ_ENABLE_CGROUPS && (SYZ_SANDBOX_NONE || SYZ_SANDBOX_SETUID || SYZ_SANDBOX_NAMESPACE || SYZ_SANDBOX_ANDROID_UNTRUSTED_APP))
 #include <fcntl.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
@@ -3522,6 +3527,10 @@ static void reset_net_namespace(void)
 
 static void setup_cgroups()
 {
+#if SYZ_EXECUTOR
+	if (!flag_enable_cgroups)
+		return;
+#endif
 	if (mkdir("/syzcgroup", 0777)) {
 		debug("mkdir(/syzcgroup) failed: %d\n", errno);
 	}
@@ -3555,8 +3564,108 @@ static void setup_cgroups()
 		debug("chmod(/syzcgroup/net) failed: %d\n", errno);
 	}
 }
+
+#if SYZ_EXECUTOR || SYZ_REPEAT
+static void setup_cgroups_loop()
+{
+#if SYZ_EXECUTOR
+	if (!flag_enable_cgroups)
+		return;
+#endif
+	int pid = getpid();
+	char file[128];
+	char cgroupdir[64];
+	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid);
+	if (mkdir(cgroupdir, 0777)) {
+		debug("mkdir(%s) failed: %d\n", cgroupdir, errno);
+	}
+	snprintf(file, sizeof(file), "%s/pids.max", cgroupdir);
+	write_file(file, "32");
+	snprintf(file, sizeof(file), "%s/memory.low", cgroupdir);
+	write_file(file, "%d", 298 << 20);
+	snprintf(file, sizeof(file), "%s/memory.high", cgroupdir);
+	write_file(file, "%d", 299 << 20);
+	snprintf(file, sizeof(file), "%s/memory.max", cgroupdir);
+	write_file(file, "%d", 300 << 20);
+	snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir);
+	write_file(file, "%d", pid);
+	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/cpu/syz%llu", procid);
+	if (mkdir(cgroupdir, 0777)) {
+		debug("mkdir(%s) failed: %d\n", cgroupdir, errno);
+	}
+	snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir);
+	write_file(file, "%d", pid);
+	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/net/syz%llu", procid);
+	if (mkdir(cgroupdir, 0777)) {
+		debug("mkdir(%s) failed: %d\n", cgroupdir, errno);
+	}
+	snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir);
+	write_file(file, "%d", pid);
+}
+
+static void setup_cgroups_test()
+{
+#if SYZ_EXECUTOR
+	if (!flag_enable_cgroups)
+		return;
+#endif
+	char cgroupdir[64];
+	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid);
+	if (symlink(cgroupdir, "./cgroup")) {
+		debug("symlink(%s, ./cgroup) failed: %d\n", cgroupdir, errno);
+	}
+	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/cpu/syz%llu", procid);
+	if (symlink(cgroupdir, "./cgroup.cpu")) {
+		debug("symlink(%s, ./cgroup.cpu) failed: %d\n", cgroupdir, errno);
+	}
+	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/net/syz%llu", procid);
+	if (symlink(cgroupdir, "./cgroup.net")) {
+		debug("symlink(%s, ./cgroup.net) failed: %d\n", cgroupdir, errno);
+	}
+}
+#endif
+
+#if SYZ_EXECUTOR || SYZ_SANDBOX_NAMESPACE
+void initialize_cgroups()
+{
+#if SYZ_EXECUTOR
+	if (!flag_enable_cgroups)
+		return;
+#endif
+	if (mkdir("./syz-tmp/newroot/syzcgroup", 0700))
+		fail("mkdir failed");
+	if (mkdir("./syz-tmp/newroot/syzcgroup/unified", 0700))
+		fail("mkdir failed");
+	if (mkdir("./syz-tmp/newroot/syzcgroup/cpu", 0700))
+		fail("mkdir failed");
+	if (mkdir("./syz-tmp/newroot/syzcgroup/net", 0700))
+		fail("mkdir failed");
+	unsigned bind_mount_flags = MS_BIND | MS_REC | MS_PRIVATE;
+	if (mount("/syzcgroup/unified", "./syz-tmp/newroot/syzcgroup/unified", NULL, bind_mount_flags, NULL)) {
+		debug("mount(cgroup2, MS_BIND) failed: %d\n", errno);
+	}
+	if (mount("/syzcgroup/cpu", "./syz-tmp/newroot/syzcgroup/cpu", NULL, bind_mount_flags, NULL)) {
+		debug("mount(cgroup/cpu, MS_BIND) failed: %d\n", errno);
+	}
+	if (mount("/syzcgroup/net", "./syz-tmp/newroot/syzcgroup/net", NULL, bind_mount_flags, NULL)) {
+		debug("mount(cgroup/net, MS_BIND) failed: %d\n", errno);
+	}
+}
+#endif
+#endif
+
+#if SYZ_EXECUTOR || (SYZ_ENABLE_BINFMT_MISC && (SYZ_SANDBOX_NONE || SYZ_SANDBOX_SETUID || SYZ_SANDBOX_NAMESPACE || SYZ_SANDBOX_ANDROID_UNTRUSTED_APP))
+#include <fcntl.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
 static void setup_binfmt_misc()
 {
+#if SYZ_EXECUTOR
+	if (!flag_enable_binfmt_misc)
+		return;
+#endif
 	if (mount(0, "/proc/sys/fs/binfmt_misc", "binfmt_misc", 0, 0)) {
 		debug("mount(binfmt_misc) failed: %d\n", errno);
 	}
@@ -3576,6 +3685,8 @@ static void setup_common()
 	}
 #if SYZ_EXECUTOR || SYZ_ENABLE_CGROUPS
 	setup_cgroups();
+#endif
+#if SYZ_EXECUTOR || SYZ_ENABLE_BINFMT_MISC
 	setup_binfmt_misc();
 #endif
 }
@@ -3802,23 +3913,7 @@ static int namespace_sandbox_proc(void* arg)
 	if (mount("/sys", "./syz-tmp/newroot/sys", 0, bind_mount_flags, NULL))
 		fail("mount(sysfs) failed");
 #if SYZ_EXECUTOR || SYZ_ENABLE_CGROUPS
-	if (mkdir("./syz-tmp/newroot/syzcgroup", 0700))
-		fail("mkdir failed");
-	if (mkdir("./syz-tmp/newroot/syzcgroup/unified", 0700))
-		fail("mkdir failed");
-	if (mkdir("./syz-tmp/newroot/syzcgroup/cpu", 0700))
-		fail("mkdir failed");
-	if (mkdir("./syz-tmp/newroot/syzcgroup/net", 0700))
-		fail("mkdir failed");
-	if (mount("/syzcgroup/unified", "./syz-tmp/newroot/syzcgroup/unified", NULL, bind_mount_flags, NULL)) {
-		debug("mount(cgroup2, MS_BIND) failed: %d\n", errno);
-	}
-	if (mount("/syzcgroup/cpu", "./syz-tmp/newroot/syzcgroup/cpu", NULL, bind_mount_flags, NULL)) {
-		debug("mount(cgroup/cpu, MS_BIND) failed: %d\n", errno);
-	}
-	if (mount("/syzcgroup/net", "./syz-tmp/newroot/syzcgroup/net", NULL, bind_mount_flags, NULL)) {
-		debug("mount(cgroup/net, MS_BIND) failed: %d\n", errno);
-	}
+	initialize_cgroups();
 #endif
 	if (mkdir("./syz-tmp/pivot", 0777))
 		fail("mkdir failed");
@@ -4090,12 +4185,15 @@ retry:
 
 static int inject_fault(int nth)
 {
+#if SYZ_EXECUTOR
+	if (!flag_enable_fault_injection)
+		return 0;
+#endif
 	int fd;
-	char buf[16];
-
 	fd = open("/proc/thread-self/fail-nth", O_RDWR);
 	if (fd == -1)
 		exitf("failed to open /proc/thread-self/fail-nth");
+	char buf[16];
 	sprintf(buf, "%d", nth + 1);
 	if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf))
 		exitf("failed to write /proc/thread-self/fail-nth");
@@ -4106,6 +4204,8 @@ static int inject_fault(int nth)
 #if SYZ_EXECUTOR
 static int fault_injected(int fail_fd)
 {
+	if (!flag_enable_fault_injection)
+		return 0;
 	char buf[16];
 	int n = read(fail_fd, buf, sizeof(buf) - 1);
 	if (n <= 0)
@@ -4181,35 +4281,7 @@ static void kill_and_wait(int pid, int* status)
 static void setup_loop()
 {
 #if SYZ_EXECUTOR || SYZ_ENABLE_CGROUPS
-	int pid = getpid();
-	char cgroupdir[64];
-	char file[128];
-	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid);
-	if (mkdir(cgroupdir, 0777)) {
-		debug("mkdir(%s) failed: %d\n", cgroupdir, errno);
-	}
-	snprintf(file, sizeof(file), "%s/pids.max", cgroupdir);
-	write_file(file, "32");
-	snprintf(file, sizeof(file), "%s/memory.low", cgroupdir);
-	write_file(file, "%d", 298 << 20);
-	snprintf(file, sizeof(file), "%s/memory.high", cgroupdir);
-	write_file(file, "%d", 299 << 20);
-	snprintf(file, sizeof(file), "%s/memory.max", cgroupdir);
-	write_file(file, "%d", 300 << 20);
-	snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir);
-	write_file(file, "%d", pid);
-	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/cpu/syz%llu", procid);
-	if (mkdir(cgroupdir, 0777)) {
-		debug("mkdir(%s) failed: %d\n", cgroupdir, errno);
-	}
-	snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir);
-	write_file(file, "%d", pid);
-	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/net/syz%llu", procid);
-	if (mkdir(cgroupdir, 0777)) {
-		debug("mkdir(%s) failed: %d\n", cgroupdir, errno);
-	}
-	snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir);
-	write_file(file, "%d", pid);
+	setup_cgroups_loop();
 #endif
 #if SYZ_EXECUTOR || SYZ_RESET_NET_NAMESPACE
 	checkpoint_net_namespace();
@@ -4245,21 +4317,9 @@ static void setup_test()
 	prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
 	setpgrp();
 #if SYZ_EXECUTOR || SYZ_ENABLE_CGROUPS
-	char cgroupdir[64];
-	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid);
-	if (symlink(cgroupdir, "./cgroup")) {
-		debug("symlink(%s, ./cgroup) failed: %d\n", cgroupdir, errno);
-	}
-	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/cpu/syz%llu", procid);
-	if (symlink(cgroupdir, "./cgroup.cpu")) {
-		debug("symlink(%s, ./cgroup.cpu) failed: %d\n", cgroupdir, errno);
-	}
-	snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/net/syz%llu", procid);
-	if (symlink(cgroupdir, "./cgroup.net")) {
-		debug("symlink(%s, ./cgroup.net) failed: %d\n", cgroupdir, errno);
-	}
-	write_file("/proc/self/oom_score_adj", "1000");
+	setup_cgroups_test();
 #endif
+	write_file("/proc/self/oom_score_adj", "1000");
 #if SYZ_EXECUTOR || SYZ_TUN_ENABLE
 	flush_tun();
 #endif
diff --git a/pkg/csource/options.go b/pkg/csource/options.go
index 4a0cc9fbc..d82ff28bd 100644
--- a/pkg/csource/options.go
+++ b/pkg/csource/options.go
@@ -8,6 +8,8 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"sort"
+	"strings"
 
 	"github.com/google/syzkaller/pkg/mgrconfig"
 )
@@ -27,12 +29,14 @@ type Options struct {
 	FaultNth  int  `json:"fault_nth,omitempty"`
 
 	// These options allow for a more fine-tuned control over the generated C code.
-	EnableTun     bool `json:"tun,omitempty"`
-	UseTmpDir     bool `json:"tmpdir,omitempty"`
-	EnableCgroups bool `json:"cgroups,omitempty"`
-	EnableNetdev  bool `json:"netdev,omitempty"`
-	ResetNet      bool `json:"resetnet,omitempty"`
-	HandleSegv    bool `json:"segv,omitempty"`
+	EnableTun        bool `json:"tun,omitempty"`
+	EnableNetDev     bool `json:"netdev,omitempty"`
+	EnableNetReset   bool `json:"resetnet,omitempty"`
+	EnableCgroups    bool `json:"cgroups,omitempty"`
+	EnableBinfmtMisc bool `json:"binfmt_misc,omitempty"`
+
+	UseTmpDir  bool `json:"tmpdir,omitempty"`
+	HandleSegv bool `json:"segv,omitempty"`
 
 	// Generate code for use with repro package to prints log messages,
 	// which allows to detect hangs.
@@ -58,8 +62,8 @@ func (opts Options) Check(OS string) error {
 			// This does not affect generated code.
 			return errors.New("Procs>1 without Repeat")
 		}
-		if opts.ResetNet {
-			return errors.New("ResetNet without Repeat")
+		if opts.EnableNetReset {
+			return errors.New("EnableNetReset without Repeat")
 		}
 		if opts.RepeatTimes > 1 {
 			return errors.New("RepeatTimes without Repeat")
@@ -69,11 +73,14 @@ func (opts Options) Check(OS string) error {
 		if opts.EnableTun {
 			return errors.New("EnableTun without sandbox")
 		}
+		if opts.EnableNetDev {
+			return errors.New("EnableNetDev without sandbox")
+		}
 		if opts.EnableCgroups {
 			return errors.New("EnableCgroups without sandbox")
 		}
-		if opts.EnableNetdev {
-			return errors.New("EnableNetdev without sandbox")
+		if opts.EnableBinfmtMisc {
+			return errors.New("EnableBinfmtMisc without sandbox")
 		}
 	}
 	if opts.Sandbox == sandboxNamespace && !opts.UseTmpDir {
@@ -82,12 +89,12 @@ func (opts Options) Check(OS string) error {
 		// which will fail if procs>1 and on second run of the program.
 		return errors.New("Sandbox=namespace without UseTmpDir")
 	}
+	if opts.EnableNetReset && (opts.Sandbox == "" || opts.Sandbox == sandboxSetuid) {
+		return errors.New("EnableNetReset without sandbox")
+	}
 	if opts.EnableCgroups && !opts.UseTmpDir {
 		return errors.New("EnableCgroups without UseTmpDir")
 	}
-	if opts.ResetNet && (opts.Sandbox == "" || opts.Sandbox == sandboxSetuid) {
-		return errors.New("ResetNet without sandbox")
-	}
 	return opts.checkLinuxOnly(OS)
 }
 
@@ -98,14 +105,17 @@ func (opts Options) checkLinuxOnly(OS string) error {
 	if opts.EnableTun && !(OS == "openbsd" || OS == "freebsd") {
 		return fmt.Errorf("EnableTun is not supported on %v", OS)
 	}
+	if opts.EnableNetDev {
+		return fmt.Errorf("EnableNetDev is not supported on %v", OS)
+	}
+	if opts.EnableNetReset {
+		return fmt.Errorf("EnableNetReset is not supported on %v", OS)
+	}
 	if opts.EnableCgroups {
 		return fmt.Errorf("EnableCgroups is not supported on %v", OS)
 	}
-	if opts.EnableNetdev {
-		return fmt.Errorf("EnableNetdev is not supported on %v", OS)
-	}
-	if opts.ResetNet {
-		return fmt.Errorf("ResetNet is not supported on %v", OS)
+	if opts.EnableBinfmtMisc {
+		return fmt.Errorf("EnableBinfmtMisc is not supported on %v", OS)
 	}
 	if opts.Sandbox == sandboxNamespace ||
 		(opts.Sandbox == sandboxSetuid && !(OS == "openbsd" || OS == "freebsd")) ||
@@ -120,27 +130,29 @@ func (opts Options) checkLinuxOnly(OS string) error {
 
 func DefaultOpts(cfg *mgrconfig.Config) Options {
 	opts := Options{
-		Threaded:      true,
-		Collide:       true,
-		Repeat:        true,
-		Procs:         cfg.Procs,
-		Sandbox:       cfg.Sandbox,
-		EnableTun:     true,
-		EnableCgroups: true,
-		EnableNetdev:  true,
-		ResetNet:      true,
-		UseTmpDir:     true,
-		HandleSegv:    true,
-		Repro:         true,
+		Threaded:         true,
+		Collide:          true,
+		Repeat:           true,
+		Procs:            cfg.Procs,
+		Sandbox:          cfg.Sandbox,
+		EnableTun:        true,
+		EnableNetDev:     true,
+		EnableNetReset:   true,
+		EnableCgroups:    true,
+		EnableBinfmtMisc: true,
+		UseTmpDir:        true,
+		HandleSegv:       true,
+		Repro:            true,
 	}
 	if cfg.TargetOS != linux {
 		opts.EnableTun = false
+		opts.EnableNetDev = false
+		opts.EnableNetReset = false
 		opts.EnableCgroups = false
-		opts.EnableNetdev = false
-		opts.ResetNet = false
+		opts.EnableBinfmtMisc = false
 	}
 	if cfg.Sandbox == "" || cfg.Sandbox == "setuid" {
-		opts.ResetNet = false
+		opts.EnableNetReset = false
 	}
 	if err := opts.Check(cfg.TargetOS); err != nil {
 		panic(fmt.Sprintf("DefaultOpts created bad opts: %v", err))
@@ -198,3 +210,66 @@ func DeserializeOptions(data []byte) (Options, error) {
 	}
 	return opts, err
 }
+
+type Feature struct {
+	Description string
+	Enabled     bool
+}
+
+type Features map[string]Feature
+
+func defaultFeatures(value bool) Features {
+	return map[string]Feature{
+		"tun":         {"setup and use /dev/tun for packet injection", value},
+		"net_dev":     {"setup more network devices for testing", value},
+		"net_reset":   {"reset network namespace between programs", value},
+		"cgroups":     {"setup cgroups for testing", value},
+		"binfmt_misc": {"setup binfmt_misc for testing", value},
+	}
+}
+
+func ParseFeaturesFlags(enable string, disable string, defaultValue bool) (Features, error) {
+	if enable == "none" && disable == "none" {
+		return defaultFeatures(defaultValue), nil
+	}
+	if enable != "none" && disable != "none" {
+		return nil, fmt.Errorf("can't use -enable and -disable flags at the same time")
+	}
+	if enable == "all" || disable == "" {
+		return defaultFeatures(true), nil
+	}
+	if disable == "all" || enable == "" {
+		return defaultFeatures(false), nil
+	}
+	var items []string
+	var features Features
+	if enable != "none" {
+		items = strings.Split(enable, ",")
+		features = defaultFeatures(false)
+	} else {
+		items = strings.Split(disable, ",")
+		features = defaultFeatures(true)
+	}
+	for _, item := range items {
+		if _, ok := features[item]; !ok {
+			return nil, fmt.Errorf("unknown feature specified: %s", item)
+		}
+		feature := features[item]
+		feature.Enabled = (enable != "none")
+		features[item] = feature
+	}
+	return features, nil
+}
+
+func PrintAvailableFeaturesFlags() {
+	fmt.Printf("Available features for -enable and -disable:\n")
+	features := defaultFeatures(false)
+	var names []string
+	for name := range features {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	for _, name := range names {
+		fmt.Printf("  %s - %s\n", name, features[name].Description)
+	}
+}
diff --git a/pkg/csource/options_test.go b/pkg/csource/options_test.go
index d8e8a217e..0240208e0 100644
--- a/pkg/csource/options_test.go
+++ b/pkg/csource/options_test.go
@@ -31,86 +31,91 @@ func TestParseOptionsCanned(t *testing.T) {
 		"fault":true,"fault_call":1,"fault_nth":2,"tun":true,"tmpdir":true,"cgroups":true,
 		"netdev":true,"resetnet":true,
 		"segv":true,"waitrepeat":true,"debug":true,"repro":true}`: {
-			Threaded:      true,
-			Collide:       true,
-			Repeat:        true,
-			Procs:         10,
-			Sandbox:       "namespace",
-			Fault:         true,
-			FaultCall:     1,
-			FaultNth:      2,
-			EnableTun:     true,
-			UseTmpDir:     true,
-			EnableCgroups: true,
-			EnableNetdev:  true,
-			ResetNet:      true,
-			HandleSegv:    true,
-			Repro:         true,
+			Threaded:         true,
+			Collide:          true,
+			Repeat:           true,
+			Procs:            10,
+			Sandbox:          "namespace",
+			Fault:            true,
+			FaultCall:        1,
+			FaultNth:         2,
+			EnableTun:        true,
+			EnableNetDev:     true,
+			EnableNetReset:   true,
+			EnableCgroups:    true,
+			EnableBinfmtMisc: false,
+			UseTmpDir:        true,
+			HandleSegv:       true,
+			Repro:            true,
 		},
 		`{"threaded":true,"collide":true,"repeat":true,"procs":10,"sandbox":"android_untrusted_app",
 		"fault":true,"fault_call":1,"fault_nth":2,"tun":true,"tmpdir":true,"cgroups":true,
 		"netdev":true,"resetnet":true,
 		"segv":true,"waitrepeat":true,"debug":true,"repro":true}`: {
-			Threaded:      true,
-			Collide:       true,
-			Repeat:        true,
-			Procs:         10,
-			Sandbox:       "android_untrusted_app",
-			Fault:         true,
-			FaultCall:     1,
-			FaultNth:      2,
-			EnableTun:     true,
-			UseTmpDir:     true,
-			EnableCgroups: true,
-			EnableNetdev:  true,
-			ResetNet:      true,
-			HandleSegv:    true,
-			Repro:         true,
+			Threaded:         true,
+			Collide:          true,
+			Repeat:           true,
+			Procs:            10,
+			Sandbox:          "android_untrusted_app",
+			Fault:            true,
+			FaultCall:        1,
+			FaultNth:         2,
+			EnableTun:        true,
+			EnableNetDev:     true,
+			EnableNetReset:   true,
+			EnableCgroups:    true,
+			EnableBinfmtMisc: false,
+			UseTmpDir:        true,
+			HandleSegv:       true,
+			Repro:            true,
 		},
 		"{Threaded:true Collide:true Repeat:true Procs:1 Sandbox:none Fault:false FaultCall:-1 FaultNth:0 EnableTun:true UseTmpDir:true HandleSegv:true WaitRepeat:true Debug:false Repro:false}": {
-			Threaded:      true,
-			Collide:       true,
-			Repeat:        true,
-			Procs:         1,
-			Sandbox:       "none",
-			Fault:         false,
-			FaultCall:     -1,
-			FaultNth:      0,
-			EnableTun:     true,
-			UseTmpDir:     true,
-			EnableCgroups: false,
-			HandleSegv:    true,
-			Repro:         false,
+			Threaded:         true,
+			Collide:          true,
+			Repeat:           true,
+			Procs:            1,
+			Sandbox:          "none",
+			Fault:            false,
+			FaultCall:        -1,
+			FaultNth:         0,
+			EnableTun:        true,
+			EnableCgroups:    false,
+			EnableBinfmtMisc: false,
+			UseTmpDir:        true,
+			HandleSegv:       true,
+			Repro:            false,
 		},
 		"{Threaded:true Collide:true Repeat:true Procs:1 Sandbox: Fault:false FaultCall:-1 FaultNth:0 EnableTun:true UseTmpDir:true HandleSegv:true WaitRepeat:true Debug:false Repro:false}": {
-			Threaded:      true,
-			Collide:       true,
-			Repeat:        true,
-			Procs:         1,
-			Sandbox:       "",
-			Fault:         false,
-			FaultCall:     -1,
-			FaultNth:      0,
-			EnableTun:     true,
-			UseTmpDir:     true,
-			EnableCgroups: false,
-			HandleSegv:    true,
-			Repro:         false,
+			Threaded:         true,
+			Collide:          true,
+			Repeat:           true,
+			Procs:            1,
+			Sandbox:          "",
+			Fault:            false,
+			FaultCall:        -1,
+			FaultNth:         0,
+			EnableTun:        true,
+			EnableCgroups:    false,
+			EnableBinfmtMisc: false,
+			UseTmpDir:        true,
+			HandleSegv:       true,
+			Repro:            false,
 		},
 		"{Threaded:false Collide:true Repeat:true Procs:1 Sandbox:namespace Fault:false FaultCall:-1 FaultNth:0 EnableTun:true UseTmpDir:true EnableCgroups:true HandleSegv:true WaitRepeat:true Debug:false Repro:false}": {
-			Threaded:      false,
-			Collide:       true,
-			Repeat:        true,
-			Procs:         1,
-			Sandbox:       "namespace",
-			Fault:         false,
-			FaultCall:     -1,
-			FaultNth:      0,
-			EnableTun:     true,
-			UseTmpDir:     true,
-			EnableCgroups: true,
-			HandleSegv:    true,
-			Repro:         false,
+			Threaded:         false,
+			Collide:          true,
+			Repeat:           true,
+			Procs:            1,
+			Sandbox:          "namespace",
+			Fault:            false,
+			FaultCall:        -1,
+			FaultNth:         0,
+			EnableTun:        true,
+			EnableCgroups:    true,
+			EnableBinfmtMisc: false,
+			UseTmpDir:        true,
+			HandleSegv:       true,
+			Repro:            false,
 		},
 	}
 	for data, want := range canned {
@@ -194,3 +199,49 @@ func enumerateField(OS string, opt Options, field int) []Options {
 	}
 	return checked
 }
+
+func TestParseFeaturesFlags(t *testing.T) {
+	tests := []struct {
+		Enable   string
+		Disable  string
+		Default  bool
+		Features map[string]bool
+	}{
+		{"none", "none", true, map[string]bool{
+			"tun": true, "net_dev": true, "net_reset": true, "cgroups": true, "binfmt_misc": true,
+		}},
+		{"none", "none", false, map[string]bool{
+			"tun": false, "net_dev": false, "net_reset": false, "cgroups": false, "binfmt_misc": false,
+		}},
+		{"all", "none", true, map[string]bool{
+			"tun": true, "net_dev": true, "net_reset": true, "cgroups": true, "binfmt_misc": true,
+		}},
+		{"", "none", true, map[string]bool{
+			"tun": false, "net_dev": false, "net_reset": false, "cgroups": false, "binfmt_misc": false,
+		}},
+		{"none", "all", true, map[string]bool{
+			"tun": false, "net_dev": false, "net_reset": false, "cgroups": false, "binfmt_misc": false,
+		}},
+		{"none", "", true, map[string]bool{
+			"tun": true, "net_dev": true, "net_reset": true, "cgroups": true, "binfmt_misc": true,
+		}},
+		{"tun,net_dev", "none", true, map[string]bool{
+			"tun": true, "net_dev": true, "net_reset": false, "cgroups": false, "binfmt_misc": false,
+		}},
+		{"none", "cgroups,net_dev", true, map[string]bool{
+			"tun": true, "net_dev": false, "net_reset": true, "cgroups": false, "binfmt_misc": true,
+		}},
+	}
+	for i, test := range tests {
+		features, err := ParseFeaturesFlags(test.Enable, test.Disable, test.Default)
+		if err != nil {
+			t.Fatalf("failed to parse features flags: %v", err)
+		}
+		for name, feature := range features {
+			if feature.Enabled != test.Features[name] {
+				t.Fatalf("test #%v: invalid value for feature flag %s: got %v, want %v",
+					i, name, feature.Enabled, test.Features[name])
+			}
+		}
+	}
+}