dummynet: Does not depend on ipfw

[kp]

Summary

Allow the dummynet module to be loaded without ipfw, as a first step
towards making pf use it for packet scheduling.

MFC after: 2 weeks
Sponsored by: Rubicon Communications, LLC ("Netgate")

[donner]

May this cause an unwanted effect on automatic module loading?
So may somebody depend on this dependency in the local setup?

[kp]

In D31903#719853, @donner wrote:

May this cause an unwanted effect on automatic module loading?
So may somebody depend on this dependency in the local setup?

Yes, that's a concern. Especially for merging it back to stable/13 and stable/12.
I'm planning to MFC pf/dummynet , but perhaps users in 12 and 13 are just going to have to live with the dummynet module autoloading ipfw. It's something to think about.

[melifaro]

In D31903#720341, @kp wrote:

In D31903#719853, @donner wrote:

May this cause an unwanted effect on automatic module loading?
So may somebody depend on this dependency in the local setup?

Yes, that's a concern. Especially for merging it back to stable/13 and stable/12.
I'm planning to MFC pf/dummynet , but perhaps users in 12 and 13 are just going to have to live with the dummynet module autoloading ipfw. It's something to think about.

With default to deny it might be not exactly the desired outcome. Do you think that a separate module w/ dummynet-for-pf (for 12/13) is too much of a hassle? Especially given ae@‘s plan to change dummynet for ipfw?

[kp]

In D31903#720346, @melifaro wrote:

Do you think that a separate module w/ dummynet-for-pf (for 12/13) is too much of a hassle?

That's an interesting idea. I'll give that a try. That may turn out to be the easiest fix.

Especially given ae@‘s plan to change dummynet for ipfw?

I'm hoping that we can move pf along to the new dummynet code at the same time as ipfw. Happily the interface between firewall and dummynet is pretty simple, so I don't really expect that to be a lot of work.

[kp]

In D31903#720423, @kp wrote:

In D31903#720346, @melifaro wrote:

Do you think that a separate module w/ dummynet-for-pf (for 12/13) is too much of a hassle?

That's an interesting idea. I'll give that a try. That may turn out to be the easiest fix.

https://reviews.freebsd.org/D32079

It introduced 'pfdummynet.ko', which depends on pf like dummynet.ko depends on ipfw. That's intended for stable/13 and stable/12. I'd do this for main, but not MFC it.
pfdummynet and dummynet can't be loaded at the same time, but that seems like a minor issue at most. Users will have to pick between doing dummynet with ipfw or doing it with pf.