This is much better handled by a user-land tool.
Proposed on tech-net here:
https://mail-index.netbsd.org/tech-net/2020/04/22/msg007766.html
Note that the ioctl SIOCGIFINFO_IN6 no longer sets flags. That now
needs to be done using the pre-existing SIOCSIFINFO_FLAGS ioctl.
Compat is fully provided where it makes sense, but trying to turn on
RA handling will obviously throw an error as it no longer exists.
Note that if you use IPv6 temporary addresses, this now needs to be
turned on in dhcpcd.conf(5) rather than in sysctl.conf(5).
When rip_input() is called as inetsw[].pr_input, rip_iput() is always called
with holding softnet_lock, that is, in case of !defined(NET_MPSAFE) it is
acquired in ipintr(), otherwise(defined(NET_MPSAFE)) it is acquire in
PR_WRAP_INPUT macro.
However, some function calls rip_input() directly without holding softnet_lock.
That causes assertion failure in sbappendaddr().
rip6_input() and icmp6_rip6_input() are also required softnet_lock for the same
reason.
The benefits of this change are:
- The flow is consistent with IPv4 (and FreeBSD and OpenBSD)
- old: ip6_output => nd6_output (do ND if needed) => L2_output (lookup a stored cache)
- new: ip6_output => L2_output (lookup a cache. Do ND if cache not found)
- We can remove some workarounds in nd6_output
- We can move L2 specific operations to their own place
- The performance slightly improves because one cache lookup is reduced
- Don't hold softnet_lock in some functions if NET_MPSAFE
- Add softnet_lock to sysctl_net_inet_icmp_redirtimeout
- Add softnet_lock to expire_upcalls of ip_mroute.c
- Restore softnet_lock for in{,6}_pcbpurgeif{,0} if NET_MPSAFE
- Mark some softnet_lock for future work
The motivation is the same as the mbuf's rcvif case; avoid having a pointer
of an ifnet object in ip_moptions and ip6_moptions, which is not MP-safe.
ip_moptions and ip6_moptions can be stored in a PCB for inet or inet6
that's life time is different from ifnet one and so an ifnet object can be
disappeared anytime we get it via them. Thus we need to look up an ifnet
object by if_index every time for safe.
Having a pointer of an interface in a mbuf isn't safe if we remove big
kernel locks; an interface object (ifnet) can be destroyed anytime in any
packet processing and accessing such object via a pointer is racy. Instead
we have to get an object from the interface collection (ifindex2ifnet) via
an interface index (if_index) that is stored to a mbuf instead of an
pointer.
The change provides two APIs: m_{get,put}_rcvif_psref that use psref(9)
for sleep-able critical sections and m_{get,put}_rcvif that use
pserialize(9) for other critical sections. The change also adds another
API called m_get_rcvif_NOMPSAFE, that is NOT MP-safe and for transition
moratorium, i.e., it is intended to be used for places where are not
planned to be MP-ified soon.
The change adds some overhead due to psref to performance sensitive paths,
however the overhead is not serious, 2% down at worst.
Proposed on tech-kern and tech-net.
Some codes in sys/net* use time_second to manage time periods such as
cache expirations. However, time_second doesn't increase monotonically
and can leap by say settimeofday(2) according to time_second(9). We
should use time_uptime instead of it to avoid such time leaps.
This change replaces time_second with time_uptime. Additionally it
converts a time based on time_uptime to a time based on time_second
when the kernel passes the time to userland programs that expect
the latter, and vice versa.
Note that we shouldn't leak time_uptime to other hosts over the
netowrk. My investigation shows there is no such leak:
http://mail-index.netbsd.org/tech-net/2015/08/06/msg005332.html
Discussed on tech-kern and tech-net.
- Socket layer becomes MP safe.
- Unix protocols become MP safe.
- Allows protocol processing interrupts to safely block on locks.
- Fixes a number of race conditions.
With much feedback from matt@ and plunky@.
roy