From rajeevsoni71 at gmail.com  Tue Aug  2 09:08:22 2022
From: rajeevsoni71 at gmail.com (Rajeev Soni)
Date: Tue, 2 Aug 2022 12:38:22 +0530
Subject: [Libwebsockets] Runtime Error in minimal-Mqtt-client example.
Message-ID: <CAGVds+qfk8-xr1b9VK+cVQkRRy9ZpmREzfmMRTiZBynQk9yFPQ@mail.gmail.com>

Hi Team,

I am trying to run Mqtt client from the below path..

Src Path
 : minimal-examples-lowlevel/mqtt-client/minimal-mqtt-client/minimal-mqtt-client.c
Compiled Path : libwebsockets/build/bin/lws-minimal-mqtt-client

When I am running this example binary without -s option it runs and able to
receive the published message only once and it exits with below message

------------------ Without -s Option Logs--------------
[2022/08/02 12:28:43:2254] U: LWS minimal MQTT client unencrypted
[-d<verbosity>][-s]
[2022/08/02 12:28:43:2262] N: lws_create_context: LWS:
4.3.99-v4.3.0-258-ge3ed2ba6, NET CLI SRV H1 H2 WS MQTT SS-JSON-POL ConMon
IPv6-absent
[2022/08/02 12:28:43:2263] N: __lws_lc_tag:  ++ [wsi|0|pipe] (1)
[2022/08/02 12:28:43:2264] N: __lws_lc_tag:  ++ [vh|0|netlink] (1)
[2022/08/02 12:28:43:2265] N: __lws_lc_tag:  ++ [vh|1|default||-1] (2)
[2022/08/02 12:28:43:3274] N: lws_mqtt_generate_id: User space provided a
client ID 'lwsMqttClient'
[2022/08/02 12:28:43:3274] N: __lws_lc_tag:  ++
[wsicli|0|MQTT/mqtt/default/localhost] (1)
[2022/08/02 12:28:43:3310] N: [wsicli|0|MQTT/mqtt/default/localhost]:
lws_client_connect_3_connect: trying 127.0.0.1
[2022/08/02 12:28:43:3323] N: __lws_lc_tag:  ++ [mux|0|default|mqtt_sid1]
(1)
[2022/08/02 12:28:43:3323] N: _lws_mqtt_rx_parser: migrated nwsi
[wsicli|0|MQTT/mqtt/default/localhost] to sid 1 [mux|0|default|mqtt_sid1]
[2022/08/02 12:28:43:3324] U: callback_mqtt: MQTT_CLIENT_ESTABLISHED
[2022/08/02 12:28:43:3324] U: callback_mqtt: WRITEABLE: Subscribing
[2022/08/02 12:28:43:3326] U: callback_mqtt: MQTT_SUBSCRIBED
[2022/08/02 12:28:43:3326] U: callback_mqtt: WRITEABLE: Publish
[2022/08/02 12:28:43:3327] U: callback_mqtt: MQTT_CLIENT_RX
[2022/08/02 12:28:43:3327] N:
[2022/08/02 12:28:43:3327] N: 0000: 74 65 73 74 2F 74 6F 70 69 63 30
            test/topic0
[2022/08/02 12:28:43:3327] N:
[2022/08/02 12:28:43:3328] N:
[2022/08/02 12:28:43:3328] N: 0000: E2 80 9C 68 65 6C 6C 6F E2 80 9D
            ...hello...
[2022/08/02 12:28:43:3328] N:
[2022/08/02 12:28:43:3328] U: callback_mqtt: WRITEABLE: Publish
[2022/08/02 12:28:43:3329] U: callback_mqtt: WRITEABLE: Publish
[2022/08/02 12:28:43:3329] U: callback_mqtt: WRITEABLE: Publish
[2022/08/02 12:28:43:3330] U: callback_mqtt: WRITEABLE: Publish
[2022/08/02 12:28:43:3330] U: callback_mqtt: MQTT_ACK
[2022/08/02 12:28:43:3331] U: callback_mqtt: WRITEABLE: Publish
[2022/08/02 12:28:43:3331] U: callback_mqtt: WRITEABLE: Publish
[2022/08/02 12:28:43:3332] U: callback_mqtt: WRITEABLE: Publish
[2022/08/02 12:28:43:3332] U: callback_mqtt: WRITEABLE: Publish
[2022/08/02 12:28:43:3333] U: callback_mqtt: WRITEABLE: Publish
[2022/08/02 12:28:43:3334] U: callback_mqtt: MQTT_ACK
[2022/08/02 12:28:43:3334] U: Completed: OK
[2022/08/02 12:28:43:3335] N: __lws_lc_untag:  -- [wsi|0|pipe] (0) 107.145ms
[2022/08/02 12:28:43:3335] U: callback_mqtt: CLIENT_CLOSED
[2022/08/02 12:28:43:3335] N: __lws_lc_untag:  -- [mux|0|default|mqtt_sid1]
(0) 1.189ms
[2022/08/02 12:28:43:3336] N: __lws_lc_untag:  -- [vh|1|default||-1] (1)
107.020ms
[2022/08/02 12:28:43:3336] N: __lws_lc_untag:  --
[wsicli|0|MQTT/mqtt/default/localhost] (0) 6.166ms
[2022/08/02 12:28:43:3336] N: __lws_lc_untag:  -- [vh|0|netlink] (0)
107.232ms
---------------------------------------------------------------

but as per the code it should wait for a new publish message,,,
And also I tried to execute it with -s option so that it will use a
different port number ex (8883).
but at runtime it throws the below error.

------------------WIth -s Option Logs ------------------
[2022/08/02 12:31:56:7527] U: LWS minimal MQTT client tls enabled
[-d<verbosity>][-s]
[2022/08/02 12:31:56:7536] N: lws_create_context: LWS:
4.3.99-v4.3.0-258-ge3ed2ba6, NET CLI SRV H1 H2 WS MQTT SS-JSON-POL ConMon
IPv6-absent
[2022/08/02 12:31:56:7537] N: __lws_lc_tag:  ++ [wsi|0|pipe] (1)
[2022/08/02 12:31:56:7538] N: __lws_lc_tag:  ++ [vh|0|netlink] (1)
[2022/08/02 12:31:56:7582] N: __lws_lc_tag:  ++ [vh|1|default||-1] (2)
[2022/08/02 12:31:56:8591] N: lws_mqtt_generate_id: User space provided a
client ID 'lwsMqttClient'
[2022/08/02 12:31:56:8592] N: __lws_lc_tag:  ++
[wsicli|0|MQTT/mqtt/default/localhost] (1)
[2022/08/02 12:31:56:8636] N: [wsicli|0|MQTT/mqtt/default/localhost]:
lws_client_connect_3_connect: trying 127.0.0.1
[2022/08/02 12:31:56:8651] E: callback_mqtt: CLIENT_CONNECTION_ERROR:
connect SYSCALL 104
[2022/08/02 12:31:56:8653] N: __lws_lc_untag:  --
[wsicli|0|MQTT/mqtt/default/localhost] (0) 6.106ms
[2022/08/02 12:31:56:8653] U: Completed: failed
[2022/08/02 12:31:56:8653] N: __lws_lc_untag:  -- [wsi|0|pipe] (0) 111.575ms
[2022/08/02 12:31:56:8654] N: __lws_lc_untag:  -- [vh|0|netlink] (1)
111.534ms
[2022/08/02 12:31:56:8654] N: __lws_lc_untag:  -- [vh|1|default||-1] (0)
107.250ms
---------------------------------------------------------------


--------------------Mosquitto broker Logs while using -s option in client
and -p 8883 option in broker-------------
1659423849: mosquitto version 2.0.14 starting
1659423849: Using default config.
1659423849: Starting in local only mode. Connections will only be possible
from clients running on this machine.
1659423849: Create a configuration file which defines a listener to allow
remote access.
1659423849: For more details see
https://mosquitto.org/documentation/authentication-methods/
1659423849: Opening ipv4 listen socket on port 8883.
1659423849: Opening ipv6 listen socket on port 8883.
1659423849: mosquitto version 2.0.14 running
1659423855: New connection from 127.0.0.1:35960 on port 8883.
1659423855: Client <unknown> disconnected due to malformed packet.
---------------------------------------------------------------------------------------------------------------------------------------------
Could you please help me to understand the runtime error and also execute
this code successfully.

Note:
I am running the mosquitto broker with the option below while using -s
option on the client side.
$mosquitto -p 8883

For libwebsockets i have followed below step to compile it with MQTT enable
feature

1. Download LibWebsockets:
$ git clone https://github.com/warmcat/libwebsockets.git

2. Building:
2.1. Install CMake 2.8 or greater:
http://cmake.org/cmake/resources/software.html
(Most Unix distributions comes with a packaged version also)

2.2. Install OpenSSL.

3 To enable the mqtt support.
$ cd libwebscokets
$ vim CMakeLists.txt
Turn On :   option(LWS_ROLE_MQTT "Build with support for MQTT client" ON)
Default:     option(LWS_ROLE_MQTT "Build with support for MQTT client" OFF)


4. Generate the build files (default is Make files):
```
$ cd /path/to/src
$ mkdir build
$ cd build
$ cmake ..
```

5. Finally you can build using the generated Makefile:
```
$ make && sudo make install

Thanks and regards
Rajeev Soni
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