CVS commit: src/sys/net

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Mon Aug 31 20:33:58 UTC 2020

Modified Files:
        src/sys/net: if_wg.c

Log Message:
wg: Simplify locking.

Summary: Access to a stable established session is still allowed via
psref; all other access to peer and session state is now serialized
by struct wg_peer::wgp_lock, with no dancing around a per-session
lock.  This way, the handshake paths are locked, while the data
transmission paths are pserialized.

- Eliminate struct wg_session::wgs_lock.

- Eliminate wg_get_unstable_session -- access to the unstable session
  is allowed only with struct wgp_peer::wgp_lock held.

- Push INIT_PASSIVE->ESTABLISHED transition down into a thread task.

- Push rekey down into a thread task.

- Allocate session indices only on transition from UNKNOWN and free
  them only on transition back to UNKNOWN.

- Be a little more explicit about allowed state transitions, and
  reject some nonsensical ones.

- Sprinkle assertions and comments.

- Reduce atomic r/m/w swap operations that can just as well be
  store-release.


To generate a diff of this commit:
cvs rdiff -u -r1.48 -r1.49 src/sys/net/if_wg.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.