Add Network Down event in EMACHandler Task

[kar-rahul-aws]

Description

This PR adds Network Down event in EMACHandler task.

Test Steps

Ran FreeRTOS+TCP Demo on STM32H7 NUCLEO Board.

Checklist:

• I have tested my changes. No regression in existing tests.
• I have modified and/or added unit-tests to cover the code changes in this Pull Request.

Related Issue

Forum Issue

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[ActoryOu]

Please share the verification steps and result.

[tony-josi-aws]

STM32H7 console logs while ETH cable is reconnected:

FreeRTOS_AddEndPoint: MAC: 44-47 IPv4: 192.168.2.114
vIPSetDHCP_RATimerEnableState: Off
prvCloseDHCPSocket[44-47]: closed, user count 0
PHY ID 7C130
xPhyReset: phyBMCR_RESET 0 ready
+TCP: advertise: 01E1 config 3100
prvEthernetUpdateConfig: LS mask 00 Force 1
Autonego ready: 00000004: full duplex 100 mbit high status
Network buffers: 60 lowest 60
Queue space: lowest 69
Link Status is high
DHCP-socket[44-47]: DHCP Socket Create
prvCreateDHCPSocket[44-47]: open, user count 1
vDHCP_RATimerReload: 250
Network buffers: 60 lowest 59
vDHCPProcess: offer 192.168.0.106 for MAC address 44-47
vDHCPProcess: offer 192.168.0.106 for MAC address 44-47
Started 1 / 1 tasks
IP-address : 192.168.0.106
Default IP : 192.168.2.114
End-point  : up = yes method DHCP
Net mask   : 255.255.255.0
GW         : 192.168.0.1
DNS-0      : 49.205.72.130
DNS-1      : 183.82.243.66
Broadcast  : 192.168.0.255
MAC address: 00-11-22-33-44-47

prvCloseDHCPSocket[44-47]: closed, user count 0
vDHCP_RATimerReload: 43200000
xPhyCheckLinkStatus: PHY LS now 00

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Link Status is high
DHCP-socket[44-47]: DHCP Socket Create
prvCreateDHCPSocket[44-47]: open, user count 1
vDHCP_RATimerReload: 250
Autonego ready: 00000004: full duplex 100 mbit high status
TX descriptors 1/4
vDHCPProcess: offer 192.168.0.106 for MAC address 44-47
vDHCPProcess: offer 192.168.0.106 for MAC address 44-47
IP-address : 192.168.0.106
Default IP : 192.168.2.114
End-point  : up = yes method DHCP
Net mask   : 255.255.255.0
GW         : 192.168.0.1
DNS-0      : 49.205.72.130
DNS-1      : 183.82.243.66
Broadcast  : 192.168.0.255
MAC address: 00-11-22-33-44-47

prvCloseDHCPSocket[44-47]: closed, user count 0
vDHCP_RATimerReload: 43200000

PING results while disconnected and then reconnected:

C:\Users\tonyjosi>ping 192.168.0.106

Pinging 192.168.0.106 with 32 bytes of data:
Reply from 192.168.0.105: Destination host unreachable.
Reply from 192.168.0.105: Destination host unreachable.
Reply from 192.168.0.105: Destination host unreachable.
Reply from 192.168.0.105: Destination host unreachable.

Ping statistics for 192.168.0.106:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

C:\Users\tonyjosi>ping 192.168.0.106

Pinging 192.168.0.106 with 32 bytes of data:
Reply from 192.168.0.106: bytes=32 time=2ms TTL=64
Reply from 192.168.0.106: bytes=32 time=1ms TTL=64
Reply from 192.168.0.106: bytes=32 time=1ms TTL=64
Reply from 192.168.0.106: bytes=32 time=2ms TTL=64

Ping statistics for 192.168.0.106:
    Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 1ms, Maximum = 2ms, Average = 1ms

C:\Users\tonyjosi>