Feature Request: TCP Keepalive in WiFiClientSecure

[mobizt]

Basic Infos

• This issue complies with the issue POLICY doc.
• I have read the documentation at readthedocs and the issue is not addressed there.
• I have tested that the issue is present in current master branch (aka latest git).
• I have searched the issue tracker for a similar issue.
• If there is a stack dump, I have decoded it.
• I have filled out all fields below.

Platform

• Core Version: latest (3.1.2)

Problem Description

The TCP Keepalive was already implemented in WiFiClient class but it was missing from WiFiClientSecure class.

Can you add support TCP Keepalive in WiFiClientSecure class?

Arduino/libraries/ESP8266WiFi/src/WiFiClient.cpp

Lines 417 to 440 in 57fa6cd

	void WiFiClient::keepAlive (uint16_t idle_sec, uint16_t intv_sec, uint8_t count)
	{
	_client->keepAlive(idle_sec, intv_sec, count);
	}
	bool WiFiClient::isKeepAliveEnabled () const
	{
	return _client->isKeepAliveEnabled();
	}
	uint16_t WiFiClient::getKeepAliveIdle () const
	{
	return _client->getKeepAliveIdle();
	}
	uint16_t WiFiClient::getKeepAliveInterval () const
	{
	return _client->getKeepAliveInterval();
	}
	uint8_t WiFiClient::getKeepAliveCount () const
	{
	return _client->getKeepAliveCount();
	}

[earlephilhower]

WiFiClientSecure already implements this through the magic of C++ inheritance, no? The following snippet builds fine:

#include <ESP8266WiFi.h>

void setup() {
  WiFiClientSecure s;
  s.keepAlive(1,2,3);
}

void loop() { }

[mobizt]

I test with your simple code and device crashed with this error in Serial monitor.

--------------- CUT HERE FOR EXCEPTION DECODER ---------------

Exception (28):
epc1=0x40207056 epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000000 depc=0x00000000

>>>stack>>>

ctx: cont
sp: 3ffffe30 end: 3fffffd0 offset: 0150
3fffff80:  40207558 00000000 00001388 feefeffe  
3fffff90:  00000000 00000000 00000000 3ffef504  
3fffffa0:  3ffef504 3fff0e1c feefeffe feefeffe  
3fffffb0:  feefeffe feefeffe 3ffee6f8 40204510  
3fffffc0:  feefeffe feefeffe 3fffdab0 40100c39  
<<<stack<<<

--------------- CUT HERE FOR EXCEPTION DECODER ---------------

 ets Jan  8 2013,rst cause:2, boot mode:(3,6)

load 0x4010f000, len 3424, room 16 
tail 0
chksum 0x2e
load 0x3fff20b8, len 40, room 8 
tail 0
chksum 0x2b
csum 0x2b
v0005c970
~ld

And this is the decoded stack trace.

Exception 28: LoadProhibited: A load referenced a page mapped with an attribute that does not permit loads
PC: 0x40207056
EXCVADDR: 0x00000000

Decoding stack results
0x40204510: loop_wrapper() at C:\Users\User\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\core_esp8266_main.cpp line 255

I think WiFiClientSecure should provide the public functions to calling this private WiFiClientSecure context.

Arduino/libraries/ESP8266WiFi/src/WiFiClientSecureBearSSL.h

Line 362 in 57fa6cd

std::shared_ptr<WiFiClientSecureCtx> _ctx;

[mobizt]

I have tested this before to make sure that we can't call keepAlive directly from WiFiClientSecure class. The error is the same as I post above.

I can call keepAlive from _ctx without error if I edit WiFiClientSecureBearSSL.h to make this public access.
std::shared_ptr<WiFiClientSecureCtx> _ctx;

That is why I request this feature here for WiFiClientSecure.

[earlephilhower]

Hmm, could be an issue with object slicing.

In any case, it looks like you have a solution in mind and a test case. Why not make a PR with the change?

[mobizt]

Ok, I will submit a PR for this.