Ethernet Cable Disconnect - No more Connection or Reconnection possible (STM32F407)

[JonasReich92]

Hello there,

i have some connection/re-connection problems with my opcua server, when i unplug the LAN cable.
Because of prevent memory problems i disable the most Options for the opcua Server. Perhaps in the Future i will try more options out.
But at first the Connection should be stable and when I unplug the LAN cable a re-connection should be possible again.
Perhaps you can help me here.

Hardware:
- STM32F407
- DP83826 (TI)
- etc.

Firmware:
- open62541 v1.3.6 (amalgamation)
- LwIP v2.2.0
- FreeRTOS v10.5.1
- etc.

Perhaps interesting Settings:
- Memory Management: Heap5

- lwipopts.h:

```
#define MEMP_NUM_NETBUF 4
#define MEMP_NUM_NETCONN 8

#define LWIP_COMPAT_MUTEX 1
#define LWIP_COMPAT_MUTEX_ALLOWED 1

#define LWIP_TCP_KEEPALIVE 1

/* STM32CubeMX Specific Parameters (not defined in opt.h) ---------------------*/
/* Parameters set in STM32CubeMX LwIP Configuration GUI -*/
/*----- WITH_RTOS enabled (Since FREERTOS is set) -----*/
#define WITH_RTOS 1

/*----- CHECKSUM_BY_HARDWARE enabled -----*/
#define CHECKSUM_BY_HARDWARE 1
/*-----------------------------------------------------------------------------*/

#define LWIP_TIMEVAL_PRIVATE 0 // Wenn 0, verwendet LWIP die standardmäßige time.h-Zeitstruktur
/* LwIP Stack Parameters (modified compared to initialization value in opt.h) -*/
/* Parameters set in STM32CubeMX LwIP Configuration GUI -*/
/*----- Value in opt.h for MEM_ALIGNMENT: 1 -----*/
#define MEM_ALIGNMENT 4
/*----- Value in opt.h for LWIP_ETHERNET: LWIP_ARP || PPPOE_SUPPORT -*/
#define LWIP_ETHERNET 1
/*----- Value in opt.h for LWIP_DNS_SECURE: (LWIP_DNS_SECURE_RAND_XID | LWIP_DNS_SECURE_NO_MULTIPLE_OUTSTANDING | LWIP_DNS_SECURE_RAND_SRC_PORT) -*/
#define LWIP_DNS_SECURE 7
#if 1 //jonas.reich define needed for open62541
#define LWIP_DNS 1
#endif
/*----- Value in opt.h for TCP_SND_QUEUELEN: (4*TCP_SND_BUF + (TCP_MSS - 1))/TCP_MSS -----*/
#define TCP_SND_QUEUELEN 9
/*----- Value in opt.h for TCP_SNDLOWAT: LWIP_MIN(LWIP_MAX(((TCP_SND_BUF)/2), (2 * TCP_MSS) + 1), (TCP_SND_BUF) - 1) -*/
#define TCP_SNDLOWAT 1071
/*----- Value in opt.h for TCP_SNDQUEUELOWAT: LWIP_MAX(TCP_SND_QUEUELEN)/2, 5) -*/
#define TCP_SNDQUEUELOWAT 5
/*----- Value in opt.h for TCP_WND_UPDATE_THRESHOLD: LWIP_MIN(TCP_WND/4, TCP_MSS*4) -----*/
#define TCP_WND_UPDATE_THRESHOLD 536
/*----- Value in opt.h for LWIP_NETIF_LINK_CALLBACK: 0 -----*/
#define LWIP_NETIF_LINK_CALLBACK 1
/*----- Value in opt.h for TCPIP_THREAD_STACKSIZE: 0 -----*/
#define TCPIP_THREAD_STACKSIZE 4048
/*----- Value in opt.h for TCPIP_THREAD_PRIO: 1 -----*/
#define TCPIP_THREAD_PRIO osPriorityNormal
/*----- Value in opt.h for TCPIP_MBOX_SIZE: 0 -----*/
#define TCPIP_MBOX_SIZE 6
/*----- Value in opt.h for SLIPIF_THREAD_STACKSIZE: 0 -----*/
#define SLIPIF_THREAD_STACKSIZE 1024
/*----- Value in opt.h for SLIPIF_THREAD_PRIO: 1 -----*/
#define SLIPIF_THREAD_PRIO 3
/*----- Value in opt.h for DEFAULT_THREAD_STACKSIZE: 0 -----*/
#define DEFAULT_THREAD_STACKSIZE 1024
/*----- Value in opt.h for DEFAULT_THREAD_PRIO: 1 -----*/
#define DEFAULT_THREAD_PRIO 3
/*----- Value in opt.h for DEFAULT_UDP_RECVMBOX_SIZE: 0 -----*/
#define DEFAULT_UDP_RECVMBOX_SIZE 6
/*----- Value in opt.h for DEFAULT_TCP_RECVMBOX_SIZE: 0 -----*/
#define DEFAULT_TCP_RECVMBOX_SIZE 6
/*----- Value in opt.h for DEFAULT_ACCEPTMBOX_SIZE: 0 -----*/
#define DEFAULT_ACCEPTMBOX_SIZE 6
/*----- Value in opt.h for LWIP_COMPAT_SOCKETS: 1 -----*/
#define LWIP_COMPAT_SOCKETS 0
/*----- Value in opt.h for LWIP_SOCKET_SET_ERRNO: 1 -----*/
#define LWIP_SOCKET_SET_ERRNO 0
/*----- Value in opt.h for RECV_BUFSIZE_DEFAULT: INT_MAX -----*/
#define RECV_BUFSIZE_DEFAULT 2000000000
/*----- Default Value for SO_REUSE: 0 ---*/
#define SO_REUSE 1 //Enables SO_REUSEADDR too
/*----- Value in opt.h for LWIP_STATS: 1 -----*/
#define LWIP_STATS 1
/*----- Value in opt.h for CHECKSUM_GEN_IP: 1 -----*/
#define CHECKSUM_GEN_IP 0
/*----- Value in opt.h for CHECKSUM_GEN_UDP: 1 -----*/
#define CHECKSUM_GEN_UDP 0
/*----- Value in opt.h for CHECKSUM_GEN_TCP: 1 -----*/
#define CHECKSUM_GEN_TCP 0
/*----- Value in opt.h for CHECKSUM_GEN_ICMP: 1 -----*/
#define CHECKSUM_GEN_ICMP 0
/*----- Value in opt.h for CHECKSUM_GEN_ICMP6: 1 -----*/
#define CHECKSUM_GEN_ICMP6 0
/*----- Value in opt.h for CHECKSUM_CHECK_IP: 1 -----*/
#define CHECKSUM_CHECK_IP 0
/*----- Value in opt.h for CHECKSUM_CHECK_UDP: 1 -----*/
#define CHECKSUM_CHECK_UDP 0
/*----- Value in opt.h for CHECKSUM_CHECK_TCP: 1 -----*/
#define CHECKSUM_CHECK_TCP 0
/*----- Value in opt.h for CHECKSUM_CHECK_ICMP: 1 -----*/
#define CHECKSUM_CHECK_ICMP 0
/*----- Value in opt.h for CHECKSUM_CHECK_ICMP6: 1 -----*/
#define CHECKSUM_CHECK_ICMP6 0
```

- open62541.h (options):
- the most options are disabled

```
#define UA_OPEN62541_VER_MAJOR 1
#define UA_OPEN62541_VER_MINOR 3
#define UA_OPEN62541_VER_PATCH 6
#define UA_OPEN62541_VER_LABEL "" /* Release candidate label, etc. */
#define UA_OPEN62541_VER_COMMIT "v1.3.6"
#define UA_OPEN62541_VERSION "v1.3.6"

/**
* Feature Options
* ---------------
* Changing the feature options has no effect on a pre-compiled library. */

#define UA_LOGLEVEL 700
#ifndef UA_ENABLE_AMALGAMATION
#define UA_ENABLE_AMALGAMATION
#endif
//#define UA_ENABLE_METHODCALLS
//#define UA_ENABLE_NODEMANAGEMENT
//#define UA_ENABLE_SUBSCRIPTIONS
//#define UA_ENABLE_PUBSUB
/* #undef UA_ENABLE_PUBSUB_ENCRYPTION */
/* #undef UA_ENABLE_PUBSUB_FILE_CONFIG */
/* #undef UA_ENABLE_PUBSUB_ETH_UADP */
/* #undef UA_ENABLE_PUBSUB_DELTAFRAMES */
//#define UA_ENABLE_PUBSUB_INFORMATIONMODEL
/* #undef UA_ENABLE_PUBSUB_INFORMATIONMODEL_METHODS */
//#define UA_ENABLE_DA
/* #undef UA_ENABLE_DIAGNOSTICS */
/* #undef UA_ENABLE_HISTORIZING */
//#define UA_ENABLE_PARSING
/* #undef UA_ENABLE_EXPERIMENTAL_HISTORIZING */
//#define UA_ENABLE_SUBSCRIPTIONS_EVENTS
/* #undef UA_ENABLE_JSON_ENCODING */
/* #undef UA_ENABLE_PUBSUB_MQTT */
/* #undef UA_ENABLE_MQTT_TLS */
/* #undef UA_ENABLE_MQTT_TLS_OPENSSL */
/* #undef UA_ENABLE_MQTT_TLS_MBEDTLS */
/* #undef UA_ENABLE_ENCRYPTION_MBEDTLS */
/* #undef UA_ENABLE_TPM2_SECURITY */
/* #undef UA_ENABLE_ENCRYPTION_OPENSSL */
/* #undef UA_ENABLE_ENCRYPTION_LIBRESSL */
#if defined(UA_ENABLE_ENCRYPTION_MBEDTLS) || defined(UA_ENABLE_ENCRYPTION_OPENSSL) || defined(UA_ENABLE_ENCRYPTION_LIBRESSL)
#define UA_ENABLE_ENCRYPTION
#endif
/* #undef UA_ENABLE_SUBSCRIPTIONS_ALARMS_CONDITIONS */

/* Multithreading */
/* #undef UA_ENABLE_IMMUTABLE_NODES */
#define UA_MULTITHREADING 0

/* Advanced Options */
//#define UA_ENABLE_STATUSCODE_DESCRIPTIONS
//#define UA_ENABLE_TYPEDESCRIPTION
//#define UA_ENABLE_NODESET_COMPILER_DESCRIPTIONS
/* #undef UA_ENABLE_DETERMINISTIC_RNG */
/* #undef UA_ENABLE_DISCOVERY */
/* #undef UA_ENABLE_DISCOVERY_MULTICAST */
/* #undef UA_ENABLE_WEBSOCKET_SERVER */
/* #undef UA_ENABLE_QUERY */
/* #undef UA_ENABLE_MALLOC_SINGLETON */
//#define UA_ENABLE_DISCOVERY_SEMAPHORE
/* #undef UA_ENABLE_UNIT_TEST_FAILURE_HOOKS */
/* #undef UA_ENABLE_VALGRIND_INTERACTIVE */
//#define UA_VALGRIND_INTERACTIVE_INTERVAL 1000
//#define UA_GENERATED_NAMESPACE_ZERO
/* #undef UA_GENERATED_NAMESPACE_ZERO_FULL */
/* #undef UA_ENABLE_PUBSUB_MONITORING */
/* #undef UA_ENABLE_PUBSUB_BUFMALLOC */

/* #undef UA_PACK_DEBIAN */

/* Options for Debugging */
/* #undef UA_DEBUG */
/* #undef UA_DEBUG_DUMP_PKGS */
/* #undef UA_DEBUG_FILE_LINE_INFO */
```

- OPCUA_TASK.c - Task to setup the server and start it:

```
/**
* Initialize the OPC UA Task
*/
void OpcUaTaskRun(void)
{
osThreadDef(opcuaTask, opcuaMain, osPriorityNormal, 0, 4*1024);
opcuaTaskHandle = osThreadCreate(osThread(opcuaTask), NULL);

}

/**
* The OPC UA task which initialize the OPC UA Server
*
* @PAram argument Task arguments
*/
void opcuaMain(void const * argument)
{
UA_StatusCode status;
char* address;
UA_UInt32 sendBufferSize = 8192; //64 KB was too much for my platform
UA_UInt32 recvBufferSize = 8192; //64 KB was too much for my platform
UA_UInt16 portNumber = 4840;
IPADDRESS_T IpAddress;
static BaseType_t notify_status;
uint32_t notificationValue;
UA_UInt16 timeout = 0;

notify_status = xTaskNotifyWait(0x00, 0xFFFFFFFF, &notificationValue, portMAX_DELAY);

IpAddress = GetIpSettings();

address = GetAddressChar(IpAddress.address);

UA_Server* mUaServer = UA_Server_new();

UA_ServerConfig *uaServerConfig = UA_Server_getConfig(mUaServer);

UA_ServerConfig_setMinimalCustomBuffer(uaServerConfig, portNumber, 0, sendBufferSize, recvBufferSize);

UA_ServerConfig_setCustomHostname(uaServerConfig, UA_STRING(address));

status = Init_Server_Nodes(mUaServer);

status = UA_Server_run(mUaServer, &running);

UNUSED(status);

UA_Server_delete(mUaServer);
}
```

[mbarg.1]

This bug is well known and was reported years ago.

As LWIP/FreeRtos was stopped in favour of AZRTOS/NetxDuo, no fix have been implemented.

LWIP/FreeRtos has many more bugs and I will suggest to have alook at AZRTOS/NetxDuo.

AZRTOS so far has proven to be reliable and stable.

NetXDuo is not bug free but many step better than LWIP.

Or read all  LWIP/FreeRtos code and fix yourself all bugs.

[Andrew Neil]

---

@mbarg.1 wrote:

This bug is well known and was reported years ago.

---

Have you got a reference for that?

Is it a general LWIP/FreeRtos issue, or something specific to STM32?

[mbarg.1]

I have to roll back to 2021/22 ...

I found several bugs, many more were in contributions from other developers -

Than I had a F2F meeting with STM developer and he refused to discuss FreeRtos bugs as AZRTOS was the only system with ongoing maintenance - my bug list was of no interest.

I remember that plugging/unplugging ethernet cable was one open issue.

I did not have checked recently in new releases but I did not see any announcement that FreeRtos has been fixed - same for LWIP.

Do you have some insider that FreeRTOS/LWIP is coming again?

[Andrew Neil]

---

@mbarg.1 wrote:

Do you have some insider that FreeRTOS/LWIP is coming again?

---

No - just wondering.

@JonasReich92 a forum search for "plug unplug ethernet" showed some possibly interesting hits...

https://community.st.com/t5/forums/searchpage/tab/message?advanced=false&allow_punctuation=false&q=plug%20unplug%20ethernet