This directory contains DNS library which is a modified copy of Chromium's DNS code (net/dns). The current files are taken from milestone M88 of the code with the latest commit hash of
DNS library is used by:
It provides DNS functionalities of:
The code here is a modification of Chromium's DNS code. The modification is done to minimize the code imported. Currently, the necessary functions we want are:
DnsQuery::Parse(for parsing queries),
WriteAnswer, ... (for writing raw responses).
The modification process is done by importing only the necessary functions, followed by importing the minimal amount of code necessary to make the necessary functions work. For example, functionality of writing DNS queries and parsing DNS responses are removed.
Below are the changes made:
An alternative is to having a modified copy of the Chromium's DNS code is to port the DNS code to libchrome. Although it avoids having to copy and maintain duplicated code, it has the downsides of needing to continuously update the code alongside libchrome uprevs and having to include the whole DNS code.
Another option would be to use a low level library like libbind9. One disadvantage of going with this approach is introducing additional payload by adding the development package. The API of the library is also fairly complicated and prone to introducing semantic bugs.