[netif-posix] add an option to persistent interface (#8033)

src/posix/main.c

@@ -141,6 +141,7 @@ enum
     OT_POSIX_OPT_DRY_RUN                 = 'n',
     OT_POSIX_OPT_HELP                    = 'h',
     OT_POSIX_OPT_INTERFACE_NAME          = 'I',
+    OT_POSIX_OPT_PERSISTENT_INTERFACE    = 'p',
     OT_POSIX_OPT_TIME_SPEED              = 's',
     OT_POSIX_OPT_VERBOSE                 = 'v',
 
@@ -156,6 +157,7 @@ static const struct option kOptions[] = {
     {"dry-run", no_argument, NULL, OT_POSIX_OPT_DRY_RUN},
     {"help", no_argument, NULL, OT_POSIX_OPT_HELP},
     {"interface-name", required_argument, NULL, OT_POSIX_OPT_INTERFACE_NAME},
+    {"persistent-interface", no_argument, NULL, OT_POSIX_OPT_PERSISTENT_INTERFACE},
     {"radio-version", no_argument, NULL, OT_POSIX_OPT_RADIO_VERSION},
     {"real-time-signal", required_argument, NULL, OT_POSIX_OPT_REAL_TIME_SIGNAL},
     {"time-speed", required_argument, NULL, OT_POSIX_OPT_TIME_SPEED},
@@ -174,6 +176,7 @@ static void PrintUsage(const char *aProgramName, FILE *aStream, int aExitCode)
             "    -I  --interface-name name     Thread network interface name.\n"
             "    -n  --dry-run                 Just verify if arguments is valid and radio spinel is compatible.\n"
             "        --radio-version           Print radio firmware version.\n"
+            "    -p  --persistent-interface    Persistent the created thread network interface\n"
             "    -s  --time-speed factor       Time speed up factor.\n"
             "    -v  --verbose                 Also log to stderr.\n",
             aProgramName);
@@ -191,8 +194,9 @@ static void ParseArg(int aArgCount, char *aArgVector[], PosixConfig *aConfig)
 {
     memset(aConfig, 0, sizeof(*aConfig));
 
-    aConfig->mPlatformConfig.mSpeedUpFactor = 1;
+    aConfig->mPlatformConfig.mPersistentInterface = false;
-    aConfig->mLogLevel                      = OT_LOG_LEVEL_CRIT;
+    aConfig->mPlatformConfig.mSpeedUpFactor       = 1;
+    aConfig->mLogLevel                            = OT_LOG_LEVEL_CRIT;
 #ifdef __linux__
     aConfig->mPlatformConfig.mRealTimeSignal = SIGRTMIN;
 #endif
@@ -202,7 +206,7 @@ static void ParseArg(int aArgCount, char *aArgVector[], PosixConfig *aConfig)
     while (true)
     {
         int index  = 0;
-        int option = getopt_long(aArgCount, aArgVector, "B:d:hI:ns:v", kOptions, &index);
+        int option = getopt_long(aArgCount, aArgVector, "B:d:hI:nps:v", kOptions, &index);
 
         if (option == -1)
         {
@@ -220,6 +224,9 @@ static void ParseArg(int aArgCount, char *aArgVector[], PosixConfig *aConfig)
         case OT_POSIX_OPT_INTERFACE_NAME:
             aConfig->mPlatformConfig.mInterfaceName = optarg;
             break;
+        case OT_POSIX_OPT_PERSISTENT_INTERFACE:
+            aConfig->mPlatformConfig.mPersistentInterface = true;
+            break;
         case OT_POSIX_OPT_BACKBONE_INTERFACE_NAME:
             aConfig->mPlatformConfig.mBackboneInterfaceName = optarg;
             break;

src/posix/platform/include/openthread/openthread-system.h

@@ -80,6 +80,7 @@ typedef struct otPlatformConfig
     uint8_t     mRadioUrlNum;                                  ///< Number of Radio URLs.
     int         mRealTimeSignal;                               ///< The real-time signal for microsecond timer.
     uint32_t    mSpeedUpFactor;                                ///< Speed up factor.
+    bool        mPersistentInterface;                          ///< Whether persistent the interface
     bool        mDryRun;                                       ///< If 'DryRun' is set, the posix daemon will exit
                                                                ///< directly after initialization.
 } otPlatformConfig;

src/posix/platform/netif.cpp

@@ -533,12 +533,13 @@ exit:
     SuccessOrDie(error);
 }
 
-static void UpdateLink(otInstance *aInstance)
+static void SetLinkState(otInstance *aInstance, bool aState)
 {
+    OT_UNUSED_VARIABLE(aInstance);
+
     otError      error = OT_ERROR_NONE;
     struct ifreq ifr;
     bool         ifState = false;
-    bool         otState = false;
 
     assert(gInstance == aInstance);
 
@@ -548,14 +549,13 @@ static void UpdateLink(otInstance *aInstance)
     VerifyOrExit(ioctl(sIpFd, SIOCGIFFLAGS, &ifr) == 0, perror("ioctl"); error = OT_ERROR_FAILED);
 
     ifState = ((ifr.ifr_flags & IFF_UP) == IFF_UP) ? true : false;
-    otState = otIp6IsEnabled(aInstance);
 
-    otLogNotePlat("[netif] Changing interface state to %s%s.", otState ? "up" : "down",
+    otLogNotePlat("[netif] Changing interface state to %s%s.", aState ? "up" : "down",
-                  (ifState == otState) ? " (already done, ignoring)" : "");
+                  (ifState == aState) ? " (already done, ignoring)" : "");
 
-    if (ifState != otState)
+    if (ifState != aState)
     {
-        ifr.ifr_flags = otState ? (ifr.ifr_flags | IFF_UP) : (ifr.ifr_flags & ~IFF_UP);
+        ifr.ifr_flags = aState ? (ifr.ifr_flags | IFF_UP) : (ifr.ifr_flags & ~IFF_UP);
         VerifyOrExit(ioctl(sIpFd, SIOCSIFFLAGS, &ifr) == 0, perror("ioctl"); error = OT_ERROR_FAILED);
 #if defined(RTM_NEWLINK) && defined(RTM_DELLINK)
         // wait for RTM_NEWLINK event before processing notification from kernel to avoid infinite loop
@@ -570,6 +570,12 @@ exit:
     }
 }
 
+static void UpdateLink(otInstance *aInstance)
+{
+    assert(gInstance == aInstance);
+    SetLinkState(aInstance, otIp6IsEnabled(aInstance));
+}
+
 #if defined(__linux__)
 template <size_t N> otError AddRoute(const uint8_t (&aAddress)[N], uint8_t aPrefixLen, uint32_t aPriority)
 {
@@ -1597,21 +1603,27 @@ exit:
 
 #if defined(__linux__)
 // set up the tun device
-static void platformConfigureTunDevice(const char *aInterfaceName, char *deviceName, size_t deviceNameLen)
+static void platformConfigureTunDevice(otPlatformConfig *aPlatformConfig)
 {
     struct ifreq ifr;
+    const char * interfaceName;
 
     sTunFd = open(OPENTHREAD_POSIX_TUN_DEVICE, O_RDWR | O_CLOEXEC | O_NONBLOCK);
     VerifyOrDie(sTunFd >= 0, OT_EXIT_ERROR_ERRNO);
 
     memset(&ifr, 0, sizeof(ifr));
-    ifr.ifr_flags = IFF_TUN | IFF_NO_PI | static_cast<short>(IFF_TUN_EXCL);
+    ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
-
+    if (!aPlatformConfig->mPersistentInterface)
-    if (aInterfaceName)
     {
-        VerifyOrDie(strlen(aInterfaceName) < IFNAMSIZ, OT_EXIT_INVALID_ARGUMENTS);
+        ifr.ifr_flags |= static_cast<short>(IFF_TUN_EXCL);
+    }
 
-        strncpy(ifr.ifr_name, aInterfaceName, IFNAMSIZ);
+    interfaceName = aPlatformConfig->mInterfaceName;
+    if (interfaceName)
+    {
+        VerifyOrDie(strlen(interfaceName) < IFNAMSIZ, OT_EXIT_INVALID_ARGUMENTS);
+
+        strncpy(ifr.ifr_name, interfaceName, IFNAMSIZ);
     }
     else
     {
@@ -1619,9 +1631,18 @@ static void platformConfigureTunDevice(const char *aInterfaceName, char *deviceN
     }
 
     VerifyOrDie(ioctl(sTunFd, TUNSETIFF, static_cast<void *>(&ifr)) == 0, OT_EXIT_ERROR_ERRNO);
-    VerifyOrDie(ioctl(sTunFd, TUNSETLINK, ARPHRD_VOID) == 0, OT_EXIT_ERROR_ERRNO);
 
-    strncpy(deviceName, ifr.ifr_name, deviceNameLen);
+    strncpy(gNetifName, ifr.ifr_name, sizeof(gNetifName));
+
+    if (aPlatformConfig->mPersistentInterface)
+    {
+        VerifyOrDie(ioctl(sTunFd, TUNSETPERSIST, 1) == 0, OT_EXIT_ERROR_ERRNO);
+        // Set link down to reset the tun configuration.
+        // This will drop all existing IP addresses on the interface.
+        SetLinkState(gInstance, false);
+    }
+
+    VerifyOrDie(ioctl(sTunFd, TUNSETLINK, ARPHRD_VOID) == 0, OT_EXIT_ERROR_ERRNO);
 
     ifr.ifr_mtu = static_cast<int>(kMaxIp6Size);
     VerifyOrDie(ioctl(sIpFd, SIOCSIFMTU, static_cast<void *>(&ifr)) == 0, OT_EXIT_ERROR_ERRNO);
@@ -1629,9 +1650,9 @@ static void platformConfigureTunDevice(const char *aInterfaceName, char *deviceN
 #endif
 
 #if defined(__APPLE__) && (OPENTHREAD_POSIX_CONFIG_MACOS_TUN_OPTION == OT_POSIX_CONFIG_MACOS_UTUN)
-static void platformConfigureTunDevice(const char *aInterfaceName, char *deviceName, size_t deviceNameLen)
+static void platformConfigureTunDevice(otPlatformConfig *aPlatformConfig)
 {
-    (void)aInterfaceName;
+    (void)aPlatformConfig;
     int                 err = 0;
     struct sockaddr_ctl addr;
     struct ctl_info     info;
@@ -1654,11 +1675,11 @@ static void platformConfigureTunDevice(const char *aInterfaceName, char *deviceN
     VerifyOrDie(err == 0, OT_EXIT_ERROR_ERRNO);
 
     socklen_t devNameLen;
-    devNameLen = (socklen_t)deviceNameLen;
+    devNameLen = (socklen_t)sizeof(gNetifName);
-    err        = getsockopt(sTunFd, SYSPROTO_CONTROL, UTUN_OPT_IFNAME, deviceName, &devNameLen);
+    err        = getsockopt(sTunFd, SYSPROTO_CONTROL, UTUN_OPT_IFNAME, gNetifName, &devNameLen);
     VerifyOrDie(err == 0, OT_EXIT_ERROR_ERRNO);
 
-    otLogInfoPlat("[netif] Tunnel device name = '%s'", deviceName);
+    otLogInfoPlat("[netif] Tunnel device name = '%s'", gNetifName);
 }
 #endif
 
@@ -1681,14 +1702,14 @@ exit:
 #if defined(__NetBSD__) ||                                                                             \
     (defined(__APPLE__) && (OPENTHREAD_POSIX_CONFIG_MACOS_TUN_OPTION == OT_POSIX_CONFIG_MACOS_TUN)) || \
     defined(__FreeBSD__)
-static void platformConfigureTunDevice(const char *aInterfaceName, char *deviceName, size_t deviceNameLen)
+static void platformConfigureTunDevice(otPlatformConfig *aPlatformConfig)
 {
     int         flags = IFF_BROADCAST | IFF_MULTICAST;
     int         err;
     const char *last_slash;
     const char *path;
 
-    (void)aInterfaceName;
+    (void)aPlatformConfig;
 
     path = OPENTHREAD_POSIX_TUN_DEVICE;
 
@@ -1708,7 +1729,7 @@ static void platformConfigureTunDevice(const char *aInterfaceName, char *deviceN
     VerifyOrDie(last_slash != nullptr, OT_EXIT_ERROR_ERRNO);
     last_slash++;
 
-    strncpy(deviceName, last_slash, deviceNameLen);
+    strncpy(gNetifName, last_slash, sizeof(gNetifName));
 }
 #endif
 
@@ -1760,13 +1781,13 @@ static void platformConfigureNetLink(void)
 #endif // defined(__APPLE__) || defined(__NetBSD__) || defined(__FreeBSD__)
 }
 
-void platformNetifInit(const char *aInterfaceName)
+void platformNetifInit(otPlatformConfig *aPlatformConfig)
 {
     sIpFd = SocketWithCloseExec(AF_INET6, SOCK_DGRAM, IPPROTO_IP, kSocketNonBlock);
     VerifyOrDie(sIpFd >= 0, OT_EXIT_ERROR_ERRNO);
 
     platformConfigureNetLink();
-    platformConfigureTunDevice(aInterfaceName, gNetifName, sizeof(gNetifName));
+    platformConfigureTunDevice(aPlatformConfig);
 
     gNetifIndex = if_nametoindex(gNetifName);
     VerifyOrDie(gNetifIndex > 0, OT_EXIT_FAILURE);

src/posix/platform/platform-posix.h

@@ -244,7 +244,7 @@ void platformUartProcess(const fd_set *aReadFdSet, const fd_set *aWriteFdSet, co
  * @param[in]   aInterfaceName  A pointer to Thread network interface name.
  *
  */
-void platformNetifInit(const char *aInterfaceName);
+void platformNetifInit(otPlatformConfig *aPlatformConfig);
 
 /**
  * This function sets up platform netif.

src/posix/platform/system.cpp

@@ -154,7 +154,7 @@ void platformInit(otPlatformConfig *aPlatformConfig)
 #endif
 
 #if OPENTHREAD_CONFIG_PLATFORM_NETIF_ENABLE
-    platformNetifInit(aPlatformConfig->mInterfaceName);
+    platformNetifInit(aPlatformConfig);
 #endif
 
 #if OPENTHREAD_CONFIG_PLATFORM_UDP_ENABLE