Prevent Panic in DNS Socket by Truncating Server List #986
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- Truncate the servers list to DNS_MAX_SERVER_COUNT to prevent panics. - Ensure only the first `DNS_MAX_SERVER_COUNT` servers are used when constructing the `Socket`. - This prevents overflow issues when the provided server list is larger than the allowed maximum.
Dirbaio
approved these changes
Sep 12, 2024
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Summary
This PR addresses an issue in the Socket constructor where passing a server list longer than
DNS_MAX_SERVER_COUNTwould cause a panic. The number of DNS servers available is often dictated by the network configuration, especially when using DHCP, and is not something the developer can directly control. As such, the previous behaviour of panicking when more servers are provided than allowed feels like a landmine.The code now safely truncates the server list to ensure it does not exceed the maximum allowed number of servers, preventing any runtime panics.
Changes
Why This Fix?
This fix is essential for environments where the number of servers may dynamically change or where input server lists might inadvertently exceed the allowed limit. The developer cannot know ahead of time how many DNS servers might be available to a user, and although setting
DNS_MAX_SERVER_COUNTto a higher value limits the likelihood of this happening, it can still happen. The previous behaviour would result in a panic, whereas the new implementation gracefully handles the case by truncating the server list.