API Bug of the Week: getsockname().

A “non-blocking” IPv6 connect() call was in fact, blocking.  Tracking that down made me realize the IPv6 address was mostly random garbage, which was caused by this function: bool get_fd_addr(int fd, struct protocol_net_address *addr) { union { struct sockaddr sa; struct sockaddr_in in; struct sockaddr_in6 in6; } u; socklen_t len = sizeof(len); if (getsockname(fd, &u.sa, …

Rusty Goes on Sabbatical, June to December

At linux.conf.au I spoke about my pre-alpha implementation of Pettycoin, but progress since then has been slow.  That’s partially due to yak shaving (like rewriting ccan/io library), partially reimplementation of parts I didn’t like, and partially due to the birth of my son, but mainly because I have a day job which involves working on …

Effects of packet/data sizes on various networks

I was thinking about peer-to-peer networking (in the context of Pettycoin, of course) and I wondered if sending ~1420 bytes of data is really any slower than sending 1 byte on real networks.  Similarly, is it worth going to extremes to avoid crossing over into two TCP packets? So I wrote a simple Linux TCP …

Legal Questions About Localbitcoins.com and Australia

As my previous post documented, I’ve experimented with localbitcoins.com.  Following the arrest of two Miami men for trading on localbitcoins, I decided to seek legal advice on the sitation in Australia. Online research led me to Nick Karagiannis of Kelly and Co, who was already familiar with Bitcoin: I guess it’s a rare opportunity for …

Pettycoin and working with limited visibility.

At linux.conf.au I gave a last-minute talk previewing my work on pettycoin (video, slides), an experiment to shard a bitcoin-like network.  The idea is to trade off some security and robustness in return for scale, but use it only for small amounts where fraud is less worthwhile.  On the bitcoin network today this is already …

linux.conf.au 2014: Rusty’s Must See List

Delightedly finished reading through the linux.conf.au program.  Some nasty clashes have me still arguing with myself, but here are my personal compulsory attendance talks.  Your preferences will no-doubt differ, so I’ve tried to explain my reasons:   Tridgell: Open Hardware Differential GPS – I spoke to Tridge about this, and the abstract completely undersells it. …