CVSROOT: /cvs
Module name: src
Changes by: [email protected] 2025/12/11 00:26:02
Modified files:
sys/net : if_tun.c
Log message:
let tun pretend it's a softnet thread with it's own tun_input_process.
this largely reimplements if_vinput and if_input_process in tun so
packets pushed through the stack from a tun/tap write can operate
largely like they're being processed by a softnet thread.
there's a couple of important differences between tun/tap and softnet
thought. firstly, multiple threads/processes can write to a single
tun/tap descriptor concurrently, so each thread has its own netstack
struct on the stack. secondly, these tun/tap threads are not the
softnet threads, so they can't avoid taking real interface references
when processing requeued packets.
the alternative to this woudl be letting tun/tap writes queue packets
for processing in a softnet thread, but that adds latency and
requires a lot of thought about a backpressure mechanism when a
thread writes too fast for the stack to process.
