Ping using ICMP ECHO_REQUEST

[nonameplum]

Hi, I'm quite a newbie in the ESP programming world.

I have searched the whole internet but couldn't find information if I can implement something similar to https://www.geeksforgeeks.org/ping-in-c/ (I don't need DNS lookup etc). The only thing I need is to check if the given IP address in local WiFi is reachable.

I implemented something similar using Ping by TCP but the downside is that there must be an open socket port on the IP that I try to PING or ping some external server e.g. http address on port 80.

[nonameplum]

I have found that on ESP-IDF this could be easily achieved by https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/protocols/icmp_echo.html.

[maxgerhardt]

According to the LwIP example apps/ping you can just open a raw socket (if LWIP_RAW is defined in the LwIP stack, that is) and construct the ICMP echo header and data yourself. Have you tried using that code?

[nonameplum]

@maxgerhardt I wasn't aware of the LwIP ping so what I have found is:

• ./esp-open-sdk/esp-open-lwip/include/lwip/app/ping.h
• ./esp-open-sdk/esp-open-lwip/lwip/app/ping.c

After some fight with the imports and different functions used in the esp-open-sdk I compiled it but I didn't run on the ESP8266 device yet. I will check it on Monday if all that work was worth it.

But anyway seems like your suggestion is far more superior as the implementation should be already compatible with esp-open-rtos.

You can take a look at my ping.c port here https://github.com/nonameplum/esp-homekit-demo/commit/60437fa101ca7eabd1faf6cdd29b360c599ebe3e

[nonameplum]

@maxgerhardt Do you have an idea how to use https://github.com/SuperHouse/esp-open-rtos/issues/738#issuecomment-562867728 it? I have made changes to my project and I able to build it with LwIP ping implementation but I'm not sure how to check if ping was send correctly, received etc. I made a new branch for LwIP ping usage https://github.com/nonameplum/esp-homekit-demo/tree/my_garage_lwip_ping

In the implementation of ping in esp-open-sdk I can easier assume how it might work as you can explicitly specify the callbacks. But still I have no idea if it will even work on the device.

[maxgerhardt]

The LwIP I referenced was that which is reference by esp-open-rtos in https://github.com/SuperHouse/esp-open-rtos/tree/master/lwip, not the one esp-open-sdk (which seems to be different?) uses.

I'll try to quickly build a minimal esp-open-rtos application which demonstrates and verifies the ping functionality.

[nonameplum]

Seems like in the project configuration that I have I don't have ping.h. I see that esp-open-rtos is pointing to https://github.com/SuperHouse/esp-open-rtos/tree/master/lwip which doesn't contain contrip part https://github.com/ourairquality/lwip/tree/d74e9ad2f7c9db996fb398cd41bf59ef463ae6fe

Btw: My project is based on https://github.com/maximkulkin/esp-homekit-demo

[nonameplum]

@maxgerhardt Thank you very much. I have no words to people like you for such a help.

[maxgerhardt]

I got my development setup working fine and I can compile the ping example. I'll write a small wrapper so that it's easiert to get just the "ping result". You just want an API to ping a hostname and the result to be like ping OK, ping timeout, destination unreachable, etc. right?

[nonameplum]

Yes I would like to only know if my router ip is accessible (gateway)

[maxgerhardt]

Yeah the code works, I'll upload it soon with a nice one-shot ping measurement wrapper.

Connecting.. status 1
ip:192.168.1.135,mask:255.255.255.0,gw:192.168.1.1
Connected
Got DHCP IP: 192.168.1.135
Got GW IP: 192.168.1.1
Got Netmask: 255.255.255.0
PING thread
ping: recv 192.168.1.1 5 ms
ping: recv 192.168.1.1 2 ms
ping: recv 192.168.1.1 15 ms
ping: recv 192.168.1.1 2 ms
ping: recv 192.168.1.1 19 ms
ping: recv 192.168.1.1 12 ms
ping: recv 192.168.1.1 27 ms

[nonameplum]

Wow. Sounds perfect

[maxgerhardt]

@nonameplum Hi, could you try this example please: https://github.com/maxgerhardt/esp-open-rtos-ping-example

[nonameplum]

Works perfect. Thanks again.