Very nice!

Unfortunately, there’s many many reasons that could be the case. I’m just putting this out there since it’s easy to check for and mitigate against.

No, that’s just /api/v3/user which returns both posts and comments.

Good idea with the f2b integration.

I thought about that before just blocking unscoped requests to that endpoint in Nginx.

That was my thought, but also wasn’t sure since there might be a use-case I’m unfamiliar with. I vaguely recall seeing a feature request for Photon a while back to be able to just browse comments, so I assume that would be how it worked.

But yeah as it is now, it can be abused.

That’s my normal go-to, but more than once I’ve accidentally blocked locations that Let’s Encrypt uses for secondary validation, so I’ve had to be more precise with my firewall blocks

Lemmy. I added a comment above since LW wouldn’t let me edit the post.

Mine’s only extended with some WAF rules and I’ve got a massive laundry list of bot user agents that it blocks, but otherwise it’s pretty bog standard.

If instances have Anubis setup correctly (i.e. not in front of /api/...) then that might not help them since this is calling the API endpoint.

Can’t edit the post (Thanks Cloudflare! /s) but additional info:

• I truncated the log excerpts in the post. The user agent string in these requests isn’t shown here, but it is blank in the actual logs.
• This is for Lemmy admins only. It might apply to others in some form, but this seems to be specifically exploiting a Lemmy API endpoint
• My Nginx solution may have room for improvement; I was just trying to block that behavior without breaking comments in posts and move on with my day. Suggestions for improvement are welcome.

but I send you a PM

Oh, sorry. One of the new features in this dev branch is the ability to disable PMs and mentions. I’ve been running with those turned off. Seems like that feature is working lol.

I turned DMs back on and found the message - will try to join here when I’m back on desktop. Dunno how active I can be right now, but I am eventually going to start on Piefed so would be nice to have a sounding board.

Some of the devs are already working on shared logic/libraries between apps.

Nice!

Oh, I meant just if the instance isn’t know, I thought resolving would make it “aware” of that instance. I could be wrong. But yeah, the instance would have to federate with the other one for it to be able to resolve, though. e.g. it won’t resolve an object from an instance that is on the current instance’s “block” list.

I believe you can, yeah, and I also think that “bootstraps” that instance to yours if it doesn’t already know about it. But in that case, the way I have the search written, it’ll “fall back” to regular search which also does resolveObject. That just takes longer.

The ap_id check is just to short-circuit that behavior to avoid the lengthy, often unnecessary, search and quickly redirect you to your instance’s local copy.

Have had that working for about a week now, and it’s pretty nice. Please do steal this feature lol.

At startup, it calls /api/v3/federated_instances and stores the result to a lookup variable. Then I’ve got a couple of helper functions that accept either an instance ID or a domain name which looks them up from the lookup variable.

Email on your own domain: Yep, super easy.

Email from home IP or from the IPv4 you get assigned with a VPS: Super difficult

I think you would be better served by checking for the Link header

Can’t really do that, client-side, in a browser application. CORS is a perpetual cockblock (though I understand why it is), and I’d rather not make an internal API endpoint to do the lookup.

The application polls Lemmy’s getFederatedInstances API endpoint at startup, so it has a list of every activity pub server your instance knows about. That’s the first and primary check for the URL that’s being searched.

The second check is just to rule out non activity pub URLs that point to a federated instance (e…g. https://lemmy.world/modlog, https://lemm.world/pictrs/image/blah.webp, etc).

Goal isn’t to “catch 'em all” but to catch the most used ones. If there’s one I don’t account for, either by omission or because the federated platform didn’t exist when I made the patterns, then it will just fall back to a regular search which also includes trying to resolve it as a federated URL (which is the current behavior in all prior versions).

The goal is just to simply short-circuit the search behavior if the query is a known ap_id URL in order to avoid a lengthy search process and quickly redirect you to your instance’s local copy.

I’m making an “omnisearch” box.

Paste in an AP_ID into the search field, and it auto-resolves it and redirects you to your instance’s local copy (which is very fast) instead of going through the whole search process (which is slow). To prevent false positives, I’m matching the various ap_id formats and only doing the resolution on those; anything else gets passed to search.

Anything else that falls through the cracks just gets passed to search as usual (which also does a resolveObject lookup).

It’s to make life easier.

We’ve had this discussion :)

This application is written against the Lemmy API. It only speaks API. Eventually it’ll speak Piefed API as well, but right now, only Lemmy API.

Lemmy and Piefed only do server-to-server Activity Pub and not client-to-server AP. Clients have to use the API to interact with them. This is a Lemmy (and eventually Piefed) client.

Cool, thanks. I was close with /user guessing from memory.

I think the /users/.../post_id will be sufficient. It just needs to know that the given URL is an AP_ID before passing it off to the API call to resolveObject. Since it already knows instance.domain.tld is a federated instance, it just needs to see if the path is an AP_ID or the HTML (or something else). Thus, I don’t have to parse the whole thing, just check that enough of it matches.

Thanks!

If you have DB access, the values are in the local_site_rate_limit table. You’ll probably have to restart Lemmy’s API container to pick up any changes if you edit the values in the DB.

100 per second is what I had in my configuration, but you may bump that up to 250 or more if your instance is larger.

One of these days your mom’s gonna stop paying for your Mullvad subscription. Whaddya gonna do then?

Awesome! Win-win.