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Implement a DNS Resolver

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Implementation

Write a C program that builds a DNS query packet, sends it via UDP to 8.8.8.8 (Google Public DNS), and parses the response.

Requirements:

Create a UDP socket and connect to 8.8.8.8 on port 53
Build a DNS query packet with a valid header and question section
Encode the domain name using DNS label format (length-prefixed labels)
Set query type to A (1) and class to IN (1)
Send the packet and receive the response
Parse the response header to extract answer count
Skip the question section and parse at least one answer
Extract and display the IPv4 address from the answer
Print the raw packet bytes in hexadecimal for debugging
Print a clear message showing the resolved IP address

Why This Matters

This is exactly what glibc's res_query() and getaddrinfo() do internally against a resolver like 8.8.8.8 or 1.1.1.1, encoding names into DNS's length-prefixed label format before parsing the answer section. Dan Kaminsky's 2008 cache-poisoning attack exploited weak randomization in the very transaction ID field you set here, which is why modern resolvers randomize both the ID and the source port.

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