use rwlock accessible via external functions
(IF_AFDATA_CFG_* -> if_afdata_cfg_*()) for all control plane tasks
use rmlock (IF_AFDATA_RUN_*) for fast-path lookups.
Update route MTU in case of ifnet MTU change.
Add new RTF_FIXEDMTU to track explicitly specified MTU.
Old behavior:
ifconfig em0 mtu 1500->9000 -> all routes traversing em0 do not change MTU.
User has to manually update all routes.
ifconfig em0 mtu 9000->1500 -> all routes traversing em0 do not change MTU.
However, if ip[6]_output finds route with rt_mtu > interface mtu, rt_mtu
gets updated.
New behavior:
ifconfig em0 mtu 1500->9000 -> all interface routes in all fibs gets updated
with new MTU unless RTF_FIXEDMTU flag set on them.
ifconfig em0 mtu 9000->1500 -> all routes in all fibs gets updated with new
MTU unless RTF_FIXEDMTU flag set on them AND rt_mtu is less than ifp mtu.
route add ... -mtu XXX automatically sets RTF_FIXEDMTU flag.
route change .. -mtu 0 automatically removes RTF_FIXEDMTU flag.
PR: 194238
MFC after: 1 month
CR: D1125
* struct llentry is now basically split into 2 pieces:
all fields within 64 bytes (amd64) are now protected by both
ifdata lock AND lle lock, e.g. you require both locks to be held
exclusively for modification. All data necessary for fast path
operations is kept here. Some fields were added:
- r_l3addr - makes lookup key liev within first 64 bytes.
- r_flags - flags, containing pre-compiled decision whether given
lle contains usable data or not. Current the only flag is RLLE_VALID.
- r_len - prepend data len, currently unused
- r_kick - used to provide feedback to control plane (see below).
All other fields are protected by lle lock.
* Add simple state machine for ARP to handle "about to expire" case:
Current model (for the fast path) is the following:
- rlock afdata
- find / rlock rte
- runlock afdata
- see if "expire time" is approaching
(time_uptime + la->la_preempt > la->la_expire)
- if true, call arprequest() and decrease la_preempt
- store MAC and runlock rte
New model (data plane):
- rlock afdata
- find rte
- check if it can be used using r_* fields only
- if true, store MAC
- if r_kick field != 0 set it to 0.
- runlock afdata
New mode (control plane):
- schedule arptimer to be called in (V_arpt_keep - V_arp_maxtries)
seconds instead of V_arpt_keep.
- on first timer invocation change state from ARP_LLINFO_REACHABLE
to ARP_LLINFO_VERIFY, sets r_kick to 1 and shedules next call in
V_arpt_rexmit (default to 1 sec).
- on subsequent timer invocations in ARP_LLINFO_VERIFY state, checks
for r_kick value: reschedule if not changed, and send arprequest()
if set to zero (e.g. entry was used).
* Convert IPv4 path to use new single-lock approach. IPv6 bits to follow.
* Slow down in_arpinput(): now valid reply will (in most cases) require
acquiring afdata WLOCK twice. This is requirement for storing changed
lle data. This change will be slightly optimized in future.
* Provide explicit hash link/unlink functions for both ipv4/ipv6 code.
This will probably be moved to generic lle code once we have per-AF
hashing callback inside lltable.
* Perform lle unlink on deletion immediately instead of delaying it to
the timer routine.
* Make r244183 more explicit: use new LLE_CALLOUTREF flag to indicate the
presence of lle reference used for safe callout calls.
lla_lookup(LLE_CREATE) -> lla_create
lla_lookup(LLE_DELETE) -> lla_delete
Assume lla_create to return LLE_EXCLUSIVE lock for lle.
* Rework lla_rt_output to perform all lle changes under afdata WLOCK.
* change arp_ifscrub() ackquire afdata WLOCK, the same as arp_ifinit().
have chosen different (and more traditional) stateless/statuful
NAT64 as translation mechanism. Last non-trivial commits to both
faith(4) and faithd(8) happened more than 12 years ago, so I assume
it is time to drop RFC3142 in FreeBSD.
No objections from: net@
gcc requires variables to be initialised in two places. One of them
is correctly used only under the same conditional though.
For module builds properly check if the kernel supports INET or INET6,
as otherwise various mips kernels without IPv6 support would fail to build.
Split it into two modules: if_gre(4) for GRE encapsulation and
if_me(4) for minimal encapsulation within IP.
gre(4) changes:
* convert to if_transmit;
* rework locking: protect access to softc with rmlock,
protect from concurrent ioctls with sx lock;
* correct interface accounting for outgoing datagramms (count only payload size);
* implement generic support for using IPv6 as delivery header;
* make implementation conform to the RFC 2784 and partially to RFC 2890;
* add support for GRE checksums - calculate for outgoing datagramms and check
for inconming datagramms;
* add support for sending sequence number in GRE header;
* remove support of cached routes. This fixes problem, when gre(4) doesn't
work at system startup. But this also removes support for having tunnels with
the same addresses for inner and outer header.
* deprecate support for various GREXXX ioctls, that doesn't used in FreeBSD.
Use our standard ioctls for tunnels.
me(4):
* implementation conform to RFC 2004;
* use if_transmit;
* use the same locking model as gre(4);
PR: 164475
Differential Revision: D1023
No objections from: net@
Relnotes: yes
Sponsored by: Yandex LLC
it, except Ethernet, where it carried ng_ether(4) pointer.
For now carry the pointer in if_l2com directly.
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
Some virtual if drivers has (ab)used ifa ifa_rtrequest hook to enforce
route MTU to be not bigger that interface MTU. While ifa_rtrequest hooking
might be an option in some situation, it is not feasible to do MTU checks
there: generic (or per-domain) routing code is perfectly capable of doing
this.
We currrently have 3 places where MTU is altered:
1) route addition.
In this case domain overrides radix _addroute callback (in[6]_addroute)
and all necessary checks/fixes are/can be done there.
2) route change (especially, GW change).
In this case, there are no explicit per-domain calls, but one can
override rte by setting ifa_rtrequest hook to domain handler
(inet6 does this).
3) ifconfig ifaceX mtu YYYY
In this case, we have no callbacks, but ip[6]_output performes runtime
checks and decreases rt_mtu if necessary.
Generally, the goals are to be able to handle all MTU changes in
control plane, not in runtime part, and properly deal with increased
interface MTU.
This commit changes the following:
* removes hooks setting MTU from drivers side
* adds proper per-doman MTU checks for case 1)
* adds generic MTU check for case 2)
* The latter is done by using new dom_ifmtu callback since
if_mtu denotes L3 interface MTU, e.g. maximum trasmitted _packet_ size.
However, IPv6 mtu might be different from if_mtu one (e.g. default 1280)
for some cases, so we need an abstract way to know maximum MTU size
for given interface and domain.
* moves rt_setmetrics() before MTU/ifa_rtrequest hooks since it copies
user-supplied data which must be checked.
* removes RT_LOCK_ASSERT() from other ifa_rtrequest hooks to be able to
use this functions on new non-inserted rte.
More changes will follow soon.
MFC after: 1 month
Sponsored by: Yandex LLC
