Linux change only: add PPP support. (#1117)

Support for PPP connectivity via a cellular module is now added to the Linux platform.

cell/api/u_cell_time.h

@@ -251,6 +251,11 @@ typedef struct {
  * then it cannot also be used for CellTime and hence an error may be
  * returned if cellTimeOnly is set to false.
  *
+ * If you have compiled with U_CFG_PPP_ENABLE then calling this function,
+ * which necessarily disconnects from the network, will disconnect PPP
+ * and it will not be re-enabled until a new network connection is made,
+ * e.g. by calling uCellNetConnect().
+ *
  * @param cellHandle                 the handle of the cellular instance.
  * @param mode                       the mode that CellTime should operate in,
  *                                   must be one of #U_CELL_TIME_MODE_PULSE,

cell/src/u_cell_private.h

@@ -628,6 +628,14 @@ int32_t uCellPrivateCFunGet(const uCellPrivateInstance_t *pInstance);
  * uCellPrivateCFunMode() can be called subseqently to put it
  * back again.
  *
+ * Note: if you are calling this with a mode that powers the
+ * module down (e.g. 0 or 4) then make sure that the calling
+ * function calls uPortPppDisconnect(), _before_ it locks the
+ * cellular API mutex, in order to bring any PPP connections
+ * down first; must be before the API mutex is locked as the
+ * process of bringing down a PPP connection will call into the
+ * cellular API.
+ *
  * @param pInstance  pointer to the cellular instance.
  * @return           the previous mode or negative error code.
  */

cell/src/u_cell_pwr.c

@@ -1135,6 +1135,8 @@ static int32_t moduleConfigure(uCellPrivateInstance_t *pInstance,
                 uPortTaskBlock(1000);
             }
             uAtClientLock(atHandle);
+            // This can sometimes take a little longer than the norm
+            uAtClientTimeoutSet(atHandle, 15000);
             uAtClientCommandStart(atHandle, "AT+CFUN=");
             uAtClientWriteInt(atHandle,
                               pInstance->pModule->radioOffCfun);

cell/src/u_cell_time.c

@@ -47,6 +47,7 @@
 #include "u_port_os.h"
 #include "u_port_heap.h"
 #include "u_port_uart.h"
+#include "u_port_ppp.h"
 
 #include "u_time.h"
 
@@ -684,6 +685,12 @@ int32_t uCellTimeSyncCellEnable(uDeviceHandle_t cellHandle,
 
     if (gUCellPrivateMutex != NULL) {
 
+        // Since this function requires the normal radio
+        // operation of the module to be disabled, take any
+        // PPP connection down first (since we can't do so
+        // while the cellular API mutex is locked)
+        uPortPppDisconnect(cellHandle);
+
         U_PORT_MUTEX_LOCK(gUCellPrivateMutex);
 
         errorCode = (int32_t) U_ERROR_COMMON_INVALID_PARAMETER;

common/security/test/u_security_test.c

@@ -120,9 +120,6 @@ static uNetworkTestList_t *pStdPreamble()
 {
     uNetworkTestList_t *pList;
 
-    // In case a previous test failed
-    uNetworkTestCleanUp();
-
     U_PORT_TEST_ASSERT(uPortInit() == 0);
     U_PORT_TEST_ASSERT(uDeviceInit() == 0);
 
@@ -262,6 +259,10 @@ U_PORT_TEST_FUNCTION("[security]", "securitySeal")
     // Close the devices once more and free the list
     for (uNetworkTestList_t *pTmp = pList; pTmp != NULL; pTmp = pTmp->pNext) {
         if (*pTmp->pDevHandle != NULL) {
+            U_TEST_PRINT_LINE("taking down %s...",
+                              gpUNetworkTestTypeName[pTmp->networkType]);
+            U_PORT_TEST_ASSERT(uNetworkInterfaceDown(*pTmp->pDevHandle,
+                                                     pTmp->networkType) == 0);
             U_TEST_PRINT_LINE("closing device %s...",
                               gpUNetworkTestDeviceTypeName[pTmp->pDeviceCfg->deviceType]);
             U_PORT_TEST_ASSERT(uDeviceClose(*pTmp->pDevHandle, false) == 0);
@@ -400,6 +401,10 @@ U_PORT_TEST_FUNCTION("[security]", "securityPskGeneration")
     // Close the devices once more and free the list
     for (uNetworkTestList_t *pTmp = pList; pTmp != NULL; pTmp = pTmp->pNext) {
         if (*pTmp->pDevHandle != NULL) {
+            U_TEST_PRINT_LINE("taking down %s...",
+                              gpUNetworkTestTypeName[pTmp->networkType]);
+            U_PORT_TEST_ASSERT(uNetworkInterfaceDown(*pTmp->pDevHandle,
+                                                     pTmp->networkType) == 0);
             U_TEST_PRINT_LINE("closing device %s...",
                               gpUNetworkTestDeviceTypeName[pTmp->pDeviceCfg->deviceType]);
             U_PORT_TEST_ASSERT(uDeviceClose(*pTmp->pDevHandle, false) == 0);
@@ -526,6 +531,10 @@ U_PORT_TEST_FUNCTION("[security]", "securityZtp")
     // Close the devices once more and free the list
     for (uNetworkTestList_t *pTmp = pList; pTmp != NULL; pTmp = pTmp->pNext) {
         if (*pTmp->pDevHandle != NULL) {
+            U_TEST_PRINT_LINE("taking down %s...",
+                              gpUNetworkTestTypeName[pTmp->networkType]);
+            U_PORT_TEST_ASSERT(uNetworkInterfaceDown(*pTmp->pDevHandle,
+                                                     pTmp->networkType) == 0);
             U_TEST_PRINT_LINE("closing device %s...",
                               gpUNetworkTestDeviceTypeName[pTmp->pDeviceCfg->deviceType]);
             U_PORT_TEST_ASSERT(uDeviceClose(*pTmp->pDevHandle, false) == 0);

example/sockets/README.md

@@ -21,7 +21,6 @@ For the remainder of the \#defines (see "Using A xxx Module" below) you may eith
 Follow the instructions in the [port/platform/arduino](/port/platform/arduino) directory to create the Arduino library version of `ubxlib`, which will include the example here.
 
 # Using A Cellular Module
-
 `U_CFG_TEST_CELL_MODULE_TYPE`: consult [u_cell_module_type.h](/cell/api/u_cell_module_type.h) to determine the type name for the cellular module you intend to use.  For instance, to use SARA-R5 you would set `U_CFG_TEST_CELL_MODULE_TYPE` to `U_CELL_MODULE_TYPE_SARA_R5`.
 
 `U_CFG_APP_PIN_CELL_xxx`: the default values for the MCU pins connecting your cellular module to your MCU are \#defined in the file [port/platform](/port/platform)`/<platform>/mcu/<mcu>/cfg/cfg_app_platform_specific.h`.  You should check if these are correct for your board and, if not, override the values of the \#defines (where -1 means "not connected").
@@ -31,7 +30,6 @@ Follow the instructions in the [port/platform/arduino](/port/platform/arduino) d
 Obviously you will need a SIM in your board, an antenna connected and you may need to know the APN associated with the SIM (though accepting the network default often works).
 
 # Using A Wi-Fi Module
-
 `U_CFG_TEST_SHORT_RANGE_MODULE_TYPE`: consult [u_short_range_module_type.h](/common/short_range/api/u_short_range_module_type.h) to determine the type name for the short range module module you intend to use.  For instance, to use NINA-W13 you would set `U_CFG_TEST_SHORT_RANGE_MODULE_TYPE` to `U_SHORT_RANGE_MODULE_TYPE_NINA_W13`.
 
 `U_CFG_APP_PIN_SHORT_RANGE_xxx`: the default values for the MCU pins connecting your short range module to your MCU are \#defined in the file [port/platform](/port/platform)`/<platform>/mcu/<mcu>/cfg/cfg_app_platform_specific.h`.  You should check if these are correct for your board and, if not, override the values of the \#defines (where -1 means "not connected").
@@ -43,6 +41,7 @@ On the following platforms:
 
 - [ESP-IDF](/port/platform/esp-idf)
 - [Zephyr](/port/platform/zephyr)
+- [Linux](/port/platform/linux)
 
 ...and with following \[cellular\] modules: