It’s been way too long since I wrote something here, but no writing does not equal no coding :)

I’ve finished of several quite large subsystems in mdnsd, including the cache and the record database (which is used for self-claimed records). This means that it’s able to receive and cache records, and able to read self-claimed records off a configuration file and add them to its database. Read the rest of this entry »

…or something like that.

I’ve been toying and experimenting with different data structures to represent the domain name cache in mdnsd.

These are the structures I’ve seriously considered

• Radix tree/trie – It’s attractive to do lookup in O(k), but with a key length of 255 bytes (utf8) the tree would be huge, 2040 bits. Not sure it would be effective even with all the compression techniques in the book.
• Splay tree (self-balancing binary tree), scales well but key comparisons must be strcmp().
• Hash table, well obviously fast but there could be scaling problems as collisions become lager.
• “Chained” hash table – Use the fact that domain names are separated in labels (label1.label2.tld) and use one hash table on each level.

Read the rest of this entry »

Last night (local time) I submitted my initial mDNS stack to p4, it forms the foundation of the responder daemon (mdnsd). The stack is more or less complete, but I’ll see how it works out once I integrate it with the rest of the application, there will probably be some more code re-factoring (and bug fixing). Read the rest of this entry »

I’ll be hacking on Multicast DNS and Service Discovery as a part of this years Summer of Code, my mentor is Bruce M. Simpson.

There are some initial information about the project on the FreeBSD wiki, I’ll try to keep it updated as time goes. The main priority is to get the responder running and to create a clean client API.

I already have some code, I just need to get the hang of perforce so I can submit it :)