The goal was to store in ipre_mlast the last mbuf of the chain, so that
m_cat could be called on it. But it's not needed, since m_cat already
does the equivalent of TRAVERSE itself.
If it were needed, there would be a bug, since we don't call TRAVERSE on
ipre_mlast when creating a new reassembly entry.
The source address or output interface can be specified by adding IP_PKTINFO
to the control part of the message on a SOCK_DGRAM or SOCK_RAW socket.
Reviewed by ozaki-r@ and christos@. thanks.
In the MP-safe world, a rtentry stemming from a rtcache can be freed at any
points. So we need to protect rtentries somehow say by reference couting or
passive references. Regardless of the method, we need to call some release
function of a rtentry after using it.
The change adds a new function rtcache_unref to release a rtentry. At this
point, this function does nothing because for now we don't add a reference
to a rtentry when we get one from a rtcache. We will add something useful
in a further commit.
This change is a part of changes for MP-safe routing table. It is separated
to avoid one big change that makes difficult to debug by bisecting.
In the fast-forward case, when the number of flows exceeds IPFLOW_MAX, the
performmance degraded to about 50% compared to the case less than IPFLOW_MAX
flows. This modification suppresses the degradation to 65%. Furthermore,
the modified kernel is about the same performance as the original kernel
when the number of flows is less than IPFLOW_MAX.
The original patch is implemented by ryo@n.o. Thanks.
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.
We no longer need to change rtentry below if_output.
The change makes it clear where rtentries are changed (or not)
and helps forthcoming locking (os psrefing) rtentries.
rt_gwroute of rtentry is a reference to a rtentry of the gateway
for a rtentry with RTF_GATEWAY. That was used by L2 (arp and ndp)
to look up L2 addresses. By separating L2 nexthop caches, we don't
need a route for the purpose and we can stop using rt_gwroute.
By doing so, we can reduce referencing and modifying rtentries,
which makes it easy to apply a lock (and/or psref) to the
routing table and rtentries.
One issue to do this is to keep RTF_REJECT behavior. It seems it
was broken when we moved rtalloc1 things from L2 output routines
(e.g., ether_output) to ip_hresolv_output, but (fortunately?)
it works unexpectedly. What we mistook are:
- RTF_REJECT was checked for any routes in L2 output routines,
but in ip_hresolv_output it is checked only when the route
is RTF_GATEWAY
- The RTF_REJECT check wasn't copied to IPv6 (nd6_output)
It seems that rt_gwroute checks hid the mistakes and it looked
work (unexpectedly) and removing rt_gwroute checks unveil the
issue. So we need to fix RTF_REJECT checks in ip_hresolv_output
and also add them to nd6_output.
One more point we have to care is returning an errno; we need
to mimic looutput behavior. Originally RTF_REJECT check was
done either in L2 output routines or in looutput. The latter is
applied when a reject route directs to a loopback interface.
However, now RTF_REJECT check is done before looutput so to keep
the original behavior we need to return an errno which looutput
chooses. Added rt_check_reject_route does such tweaks.
Route lookups for routes of RTF_GATEWAY were done in L2 output
routines such as ether_output, but they should be done in L3
i.e., before L2 output routines. This change places the lookups
between L3 output routines (say ip_output) and the L2 output
routines.
The change is based on dyoung's patch submitted in the thread:
https://mail-index.netbsd.org/tech-net/2013/02/01/msg003847.html
You can find out detailed investigations by dyoung about the
issue in there.
Note that the change introduces a workaround for MPLS. ether_output
knew that it needs to fill the ethertype of a frame as MPLS,
based on a tag of an original route (rtentry), but now we don't
pass it to ehter_output. So we have to tell that in another way.
We use mtag to do so for now, which introduces some overhead.
We should fix it somehow in the future.
Discussed on tech-kern and tech-net.
- Replace ipintrq and ip6intrq with the pktqueue mechanism.
- Eliminate kernel-lock from ipintr() and ip6intr().
- Some preparation work to push softnet_lock out of ipintr().
Discussed on tech-net.
lock to protect the hash table of multicast address records; also, make it
private and eliminate some macros. In the long term, the lookup path ought
to be optimised.
- ip_output: eliminate 7th variadic argument; IP_RETURNMTU is flag
always used to store MTU size into struct inpcb::inp_errormtu.
- Clean up these routines: reduce #ifdefs, variable scopes, etc.
where they belong to. Make some functions and variables static.
- ip_input.c: reduce some #ifdefs, cleanup a little.
- Move some sysctls into ip_flow.c as they belong there.
No functional change.
dismantling of pr_usrreq in the protocols; no functional change intended.
PRU_ATTACH/PRU_DETACH changes will follow soon.
Bump for struct protosw. Welcome to 6.99.62!
cleans up function and one small fix is that we now stop copying user
options to the mbuf when the _EOL is given, previously this function
would continue to copy options.
- Make ipflow_reap() private to ip_flow.c, and introduce ipflow_prune()
for external callers to use (avoids returning an ipflow * that is never
actually used anyway).
roy