Flood protection patch

[fanf]

I've posted my rate limiting patch to the exim-users mailing list. You can see it at:

http://www.cus.cam.ac.uk/~fanf2/hermes/doc/antiforgery/exim-ratelimit.patch

Comments

[fanf]

gotchas

So long as you understand the options (especially the difference between strict and leaky) it should be straight-forward. One thing that's slightly poorly documented is exactly how the key is treated: it actually includes the all of the ratelimit options (m/p/opt/key), so if you tweak the configuration it effectively forgets the client's saved rate. Perhaps it shouldn't include m in the database key...

[fanf]

I've fixed the latter so that the limit is omitted from the lookup key; the period and options are still included because they change the meaning of the recorded state. This fix only matters if/when you change the limit, so you probably shouldn't change your plans.