Block ads on Kakaotalk client

The kakaotalk client on Mac is okay but the Windows client is full of ads: ads in friend list, ads in chat, ads in the corner of the screen, ad under your cursor.

It annoyed me to no end. So what’s the solution? Find a way to block it!

I used a nifty tool called TCP View (very old, but still works). It can resolve domains from IP address and is not as heavy as Wireshark 😉

I looked up the domains kakaotalk.exe connects to and found the following, so I added this to /Windows/System32/drivers/etc/hosts

#Block kakao ads
0.0.0.0 alea.adam.ad.daum.net
0.0.0.0 wat.ad.daum.net
0.0.0.0 display.ad.daum.net
0.0.0.0 analytics.ad.daum.net
0.0.0.0 ad.daum.net

And voilà! No more annoying ads!

To read: The twelve factor app

Introduction

In the modern era, software is commonly delivered as a service: called web apps, or software-as-a-service. The twelve-factor app is a methodology for building software-as-a-service apps that:

  • Use declarative formats for setup automation, to minimize time and cost for new developers joining the project;
  • Have a clean contract with the underlying operating system, offering maximum portability between execution environments;
  • Are suitable for deployment on modern cloud platforms, obviating the need for servers and systems administration;
  • Minimize divergence between development and production, enabling continuous deployment for maximum agility;
  • And can scale up without significant changes to tooling, architecture, or development practices.

The twelve-factor methodology can be applied to apps written in any programming language, and which use any combination of backing services (database, queue, memory cache, etc).

The twelve factors

I. Codebase

One codebase tracked in revision control, many deploys

II. Dependencies

Explicitly declare and isolate dependencies

III. Config

Store config in the environment

IV. Backing services

Treat backing services as attached resources

V. Build, release, run

Strictly separate build and run stages

VI. Processes

Execute the app as one or more stateless processes

VII. Port binding

Export services via port binding

VIII. Concurrency

Scale out via the process model

IX. Disposability

Maximize robustness with fast startup and graceful shutdown

X. Dev/prod parity

Keep development, staging, and production as similar as possible

XI. Logs

Treat logs as event streams

XII. Admin processes

Run admin/management tasks as one-off processes

How to write a C MQTT client using Mosquitto

Introduction

How to write a C MQTT client using Mosquitto The 2018 version, based upon this excellent post by Kevin Boone:

Writing an MQTT client C for ActiveMQ from the ground up

The article above is a good and easy starting point, but it hasn’t been updated for 2 years so when you run it with the latest version of Mosquitto, it doesn’t work – and it’s a bit hacky (using “sleep” to avoid a concurrency problem).

So I analyzed the latest mosquitto_pub code from mosquitto repository itself to see how it’s working, and this article is the result.

What’s changed

  • There’s a queue inside mosquitto, `mosquitto_loop` must be called for it to be processed. Alternatively, you can also use the `mosquitto_loop_start` and `mosquitto_loop_stop`
  • I added asynchronous (callback) processing to wait for calls to complete, instead of the ole’ sleep function
  • It’s 2018! Everyone is adopting HTTPS. Accordingly, your MQTT traffic shouldn’t be left bare for all to see! Let’s use TLS to encrypt the traffic

The code

How to use callback

I want to publish just once message, so my flow is the following

  • On connect complete -> publish a message
  • On publish complete -> start to disconnect
  • On disconnect complete -> exit the loop and return control to the main thread. If you don’t wait for this, data may not even get sent!

To do this, I set up 3 “hooks” (callback function), like this

mosquitto_connect_callback_set(mosq, my_connect_callback);

mosquitto_disconnect_callback_set(mosq, my_disconnect_callback);

mosquitto_publish_callback_set(mosq, my_publish_callback);
And then write the callback functions to execute my flow
void my_connect_callback(struct mosquitto *mosq, void *obj, int result)
{
    int rc = MOSQ_ERR_SUCCESS;
    if(!result){
        printf("Sending message...\n");
        rc = mosquitto_publish(mosq, &mid_sent, MQTT_TOPIC, strlen(text), text, qos, retain);
        if(rc){
            switch(rc){
                case MOSQ_ERR_INVAL:
                    fprintf(stderr, "Error: Invalid input. Does your topic contain '+' or '#'?\n");
                    break;
                case MOSQ_ERR_NOMEM:
                    fprintf(stderr, "Error: Out of memory when trying to publish message.\n");
                    break;
                case MOSQ_ERR_NO_CONN:
                    fprintf(stderr, "Error: Client not connected when trying to publish.\n");
                    break;
                case MOSQ_ERR_PROTOCOL:
                    fprintf(stderr, "Error: Protocol error when communicating with broker.\n");
                    break;
                case MOSQ_ERR_PAYLOAD_SIZE:
                    fprintf(stderr, "Error: Message payload is too large.\n");
                    break;
            }
            mosquitto_disconnect(mosq);
        }
    } else {
        if(result){
            fprintf(stderr, "%s\n", mosquitto_connack_string(result));
        }
    }
}

void my_disconnect_callback(struct mosquitto *mosq, void *obj, int rc)
{
    printf("Disconnected!\n");
    connected = false;
}

void my_publish_callback(struct mosquitto *mosq, void *obj, int mid)
{
    printf("Published!\n");
    if(disconnect_sent == false){
        mosquitto_disconnect(mosq);
        disconnect_sent = true;
    }
}

How to process the queue with mosquitto_loop

In the main trunk of your code, do this

int rc;
do {
//network동작 끝나기 전에 모스키토 동작을 막기위해 잠깐 딜레이가 필요
  rc = mosquitto_loop(mosq, -1, 1);
} while (rc == MOSQ_ERR_SUCCESS && connected);

How to add TLS to the connection process

Before connecting, set TLS options with mosquitto_tls_set

mosquitto_username_pw_set(mosq, MQTT_USERNAME, MQTT_PASSWORD);
mosquitto_tls_set(mosq, "ca-cert.pem", NULL, NULL, NULL, NULL);
int ret = mosquitto_connect(mosq, MQTT_HOSTNAME, MQTT_PORT, 0);

Complete publish – subscribe sample

Available at https://github.com/thanhphu/mosquitto-sample. Happy cloning!

 

Find and block unsafe content on your wordpress installation

For some reason, my WP installation decided to load some files via http instead of https

Screen Shot 2018-11-12 at 3.28.59 PM.png

To find out which file it is, I used the Javascript consoleScreen Shot 2018-11-12 at 3.29.39 PM.png

It’s wp-emoji in this case, and I don’t use emojis on my site, so I decided to block it by adding this to my theme’s functions.php

 

remove_action( 'wp_head', 'print_emoji_detection_script', 7 );
remove_action( 'wp_print_styles', 'print_emoji_styles' );