Commit Graph

76 Commits

Author SHA1 Message Date
asomers
d1b74add9a Constrain IPv6 routes to single FIBs when net.add_addr_allfibs=0
sys/netinet6/icmp6.c
	Use the interface's FIB for source address selection in ICMPv6 error
	responses.

sys/netinet6/in6.c
	In in6_newaddrmsg, announce arrival of local addresses on the
	interface's FIB only.  In in6_lltable_rtcheck, use a per-fib ND6
	cache instead of a single cache.

sys/netinet6/in6_src.c
	In in6_selectsrc, use the caller's fib instead of the default fib.
	In in6_selectsrc_socket, remove a superfluous check.

sys/netinet6/nd6.c
	In nd6_lle_event, use the interface's fib for routing socket
	messages.  In nd6_is_new_addr_neighbor, check all FIBs when trying
	to determine whether an address is a neighbor.  Also, simplify the
	code for point to point interfaces.

sys/netinet6/nd6.h
sys/netinet6/nd6.c
sys/netinet6/nd6_rtr.c
	Make defrouter_select fib-aware, and make all of its callers pass in
	the interface fib.

sys/netinet6/nd6_nbr.c
	When inputting a Neighbor Solicitation packet, consider the
	interface fib instead of the default fib for DAD.  Output NS and
	Neighbor Advertisement packets on the correct fib.

sys/netinet6/nd6_rtr.c
	Allow installing the same host route on different interfaces in
	different FIBs.  If rt_add_addr_allfibs=0, only install or delete
	the prefix route on the interface fib.

tests/sys/netinet/fibs_test.sh
	Clear some expected failures, but add a skip for the newly revealed
	BUG217871.

PR:		196361
Submitted by:	Erick Turnquist <jhujhiti@adjectivism.org>
Reported by:	Jason Healy <jhealy@logn.net>
Reviewed by:	asomers
MFC after:	3 weeks
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D9451
2017-03-17 16:50:37 +00:00
markj
0e9bbe2171 Lock the ND prefix list and add refcounting for prefixes.
This change extends the nd6 lock to protect the ND prefix list as well
as the list of advertising routers associated with each prefix. To handle
cases where the nd6 lock must be dropped while iterating over either the
prefix or default router lists, a generation counter is used to track
modifications to the lists. Additionally, a new mutex is used to serialize
prefix on-link/off-link transitions. This mutex must be acquired before
the nd6 lock and is held while updating the routing table in
nd6_prefix_onlink() and nd6_prefix_offlink().

Reviewed by:	ae, tuexen (SCTP bits)
Tested by:	Jason Wolfe <jason@llnw.com>,
		Larry Rosenman <ler@lerctr.org>
MFC after:	2 months
Differential Revision:	https://reviews.freebsd.org/D8125
2016-10-07 21:10:53 +00:00
markj
e89e3efaa6 Rename ndpr_refcnt to ndpr_addrcnt.
This field counts derived addresses and is not a true refcount for prefix
objects, so the previous name was misleading.

MFC after:	1 week
2016-09-24 01:14:25 +00:00
bz
7a1c0b1ad1 Get closer to a VIMAGE network stack teardown from top to bottom rather
than removing the network interfaces first. This change is rather larger
and convoluted as the ordering requirements cannot be separated.

Move the pfil(9) framework to SI_SUB_PROTO_PFIL, move Firewalls and
related modules to their own SI_SUB_PROTO_FIREWALL.
Move initialization of "physical" interfaces to SI_SUB_DRIVERS,
move virtual (cloned) interfaces to SI_SUB_PSEUDO.
Move Multicast to SI_SUB_PROTO_MC.

Re-work parts of multicast initialisation and teardown, not taking the
huge amount of memory into account if used as a module yet.

For interface teardown we try to do as many of them as we can on
SI_SUB_INIT_IF, but for some this makes no sense, e.g., when tunnelling
over a higher layer protocol such as IP. In that case the interface
has to go along (or before) the higher layer protocol is shutdown.

Kernel hhooks need to go last on teardown as they may be used at various
higher layers and we cannot remove them before we cleaned up the higher
layers.

For interface teardown there are multiple paths:
(a) a cloned interface is destroyed (inside a VIMAGE or in the base system),
(b) any interface is moved from a virtual network stack to a different
network stack ("vmove"), or (c) a virtual network stack is being shut down.
All code paths go through if_detach_internal() where we, depending on the
vmove flag or the vnet state, make a decision on how much to shut down;
in case we are destroying a VNET the individual protocol layers will
cleanup their own parts thus we cannot do so again for each interface as
we end up with, e.g., double-frees, destroying locks twice or acquiring
already destroyed locks.
When calling into protocol cleanups we equally have to tell them
whether they need to detach upper layer protocols ("ulp") or not
(e.g., in6_ifdetach()).

Provide or enahnce helper functions to do proper cleanup at a protocol
rather than at an interface level.

Approved by:		re (hrs)
Obtained from:		projects/vnet
Reviewed by:		gnn, jhb
Sponsored by:		The FreeBSD Foundation
MFC after:		2 weeks
Differential Revision:	https://reviews.freebsd.org/D6747
2016-06-21 13:48:49 +00:00
gnn
d75e0c471e This change re-adds L2 caching for TCP and UDP, as originally added in D4306
but removed due to other changes in the system. Restore the llentry pointer
to the "struct route", and use it to cache the L2 lookup (ARP or ND6) as
appropriate.

Submitted by:	Mike Karels
Differential Revision:	https://reviews.freebsd.org/D6262
2016-06-02 17:51:29 +00:00
markj
a09fd6097b Move IPv6 malloc tag definitions into the IPv6 code. 2016-05-20 04:45:08 +00:00
bz
d4cf530887 Mfp4 @180378:
Factor out nd6 and in6_attach initialization to their own files.
  Also move destruction into those files though still called from
  the central initialization.

  Sponsored by:	CK Software GmbH
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
Reviewed by:	gnn
Differential Revision:	https://reviews.freebsd.org/D5033
2016-03-22 15:43:47 +00:00
markj
8c873a2b1b Modify defrouter_remove() to perform the router lookup before removal.
This allows some simplification of its callers. No functional change
intended.

Tested by:	Larry Rosenman (as part of a larger change)
MFC after:	1 month
2016-03-17 19:01:44 +00:00
markj
9524b1b571 Lock the NDP default router list and count defrouter references.
This addresses a number of race conditions that can cause crashes as a
result of unsynchronized access to the list.

PR:		206904
Tested by:	Larry Rosenman <ler@lerctr.org>,
		Kevin Bowling <kevin.bowling@kev009.com>
MFC after:	2 months
Differential Revision: https://reviews.freebsd.org/D5315
2016-02-25 20:12:05 +00:00
markj
7f716b8a59 Remove a prototype for the non-existent prelist_del().
MFC after:	1 week
2016-02-17 23:53:24 +00:00
markj
9ec0a4438f Rename the flags field of struct nd_defrouter to "raflags".
This field contains the flags inherited from the corresponding router
advertisement message and is not for storing private state.

MFC after:	1 week
2016-02-12 21:15:57 +00:00
melifaro
93152c67c9 Implement interface link header precomputation API.
Add if_requestencap() interface method which is capable of calculating
  various link headers for given interface. Right now there is support
  for INET/INET6/ARP llheader calculation (IFENCAP_LL type request).
  Other types are planned to support more complex calculation
  (L2 multipath lagg nexthops, tunnel encap nexthops, etc..).

Reshape 'struct route' to be able to pass additional data (with is length)
  to prepend to mbuf.

These two changes permits routing code to pass pre-calculated nexthop data
  (like L2 header for route w/gateway) down to the stack eliminating the
  need for other lookups. It also brings us closer to more complex scenarios
  like transparently handling MPLS nexthops and tunnel interfaces.
  Last, but not least, it removes layering violation introduced by flowtable
  code (ro_lle) and simplifies handling of existing if_output consumers.

ARP/ND changes:
Make arp/ndp stack pre-calculate link header upon installing/updating lle
  record. Interface link address change are handled by re-calculating
  headers for all lles based on if_lladdr event. After these changes,
  arpresolve()/nd6_resolve() returns full pre-calculated header for
  supported interfaces thus simplifying if_output().
Move these lookups to separate ether_resolve_addr() function which ether
  returs error or fully-prepared link header. Add <arp|nd6_>resolve_addr()
  compat versions to return link addresses instead of pre-calculated data.

BPF changes:
Raw bpf writes occupied _two_ cases: AF_UNSPEC and pseudo_AF_HDRCMPLT.
Despite the naming, both of there have ther header "complete". The only
  difference is that interface source mac has to be filled by OS for
  AF_UNSPEC (controlled via BIOCGHDRCMPLT). This logic has to stay inside
  BPF and not pollute if_output() routines. Convert BPF to pass prepend data
  via new 'struct route' mechanism. Note that it does not change
  non-optimized if_output(): ro_prepend handling is purely optional.
Side note: hackish pseudo_AF_HDRCMPLT is supported for ethernet and FDDI.
  It is not needed for ethernet anymore. The only remaining FDDI user is
  dev/pdq mostly untouched since 2007. FDDI support was eliminated from
  OpenBSD in 2013 (sys/net/if_fddisubr.c rev 1.65).

Flowtable changes:
  Flowtable violates layering by saving (and not correctly managing)
  rtes/lles. Instead of passing lle pointer, pass pointer to pre-calculated
  header data from that lle.

Differential Revision:	https://reviews.freebsd.org/D4102
2015-12-31 05:03:27 +00:00
smh
45d5617154 Revert r292275 & r292379
glebius has concerns about these changes so reverting those can be discussed
and addressed.

Sponsored by:	Multiplay
2015-12-17 14:41:30 +00:00
smh
864cf18128 Fix lagg failover due to missing notifications
When using lagg failover mode neither Gratuitous ARP (IPv4) or Unsolicited
Neighbour Advertisements (IPv6) are sent to notify other nodes that the
address may have moved.

This results is slow failover, dropped packets and network outages for the
lagg interface when the primary link goes down.

We now use the new if_link_state_change_cond with the force param set to
allow lagg to force through link state changes and hence fire a
ifnet_link_event which are now monitored by rip and nd6.

Upon receiving these events each protocol trigger the relevant
notifications:
* inet4 => Gratuitous ARP
* inet6 => Unsolicited Neighbour Announce

This also fixes the carp IPv6 NA's that stopped working after r251584 which
added the ipv6_route__llma route.

The new behavour can be controlled using the sysctls:
* net.link.ether.inet.arp_on_link
* net.inet6.icmp6.nd6_on_link

Also removed unused param from lagg_port_state and added descriptions for the
sysctls while here.

PR:		156226
MFC after:	1 month
Sponsored by:	Multiplay
Differential Revision:	https://reviews.freebsd.org/D4111
2015-12-15 16:02:11 +00:00
melifaro
2bf2184989 Bring back the ability of passing cached route via nd6_output_ifp(). 2015-11-15 16:02:22 +00:00
melifaro
0dee60f8c8 Eliminate nd6_llinfo_settimer(). All consumers were converted to
use nd6_llinfo_settimer_locked() in r216022.
Make nd6_llinfo_settimer_locked() static: last external consumer was
converted in r288124.
2015-10-04 08:33:16 +00:00
melifaro
91b3356875 Eliminate nd6_nud_hint() and its TCP bindings.
Initially function was introduced in r53541 (KAME initial commit) to
  "provide hints from upper layer protocols that indicate a connection
  is making "forward progress"" (quote from RFC 2461 7.3.1 Reachability
  Confirmation).
However, it was converted to do nothing (e.g. just return) in r122922
  (tcp_hostcache implementation) back in 2003. Some defines were moved
  to tcp_var.h in r169541. Then, it was broken (for non-corner cases)
  by r186119 (L2<>L3 split) in 2008 (NULL ifp in nd6_lookup). So,
  right now this code is broken and has no "real" base users.

Differential Revision:	https://reviews.freebsd.org/D3699
2015-09-27 05:29:34 +00:00
melifaro
88b54de46b Use standard lle LLE_EXCLUSIVE request flags instead of
its redefined version.
2015-09-22 20:45:04 +00:00
melifaro
536c20752f Unify nd6 state switching by using newly-created nd6_llinfo_setstate()
function. The change is mostly mechanical with the following exception:
Last piece of nd6_resolve_slow() was refactored: ND6_LLINFO_PERMANENT
  condition was removed as always-true, explicit ND6_LLINFO_NOSTATE ->
  ND6_LLINFO_INCOMPLETE state transition was removed as duplicate.

Reviewed by:	ae
Sponsored by:	Yandex LLC
2015-09-21 11:19:53 +00:00
melifaro
493325342d Simplify the way of attaching IPv6 link-layer header.
Problem description:
How do we currently perform layer 2 resolution and header imposition:

For IPv4 we have the following chain:
  ip_output() -> (ether|atm|whatever)_output() -> arpresolve()

Lookup is done in proper place (link-layer output routine) and it is possible
  to provide cached lle data.

For IPv6 situation is more complex:
  ip6_output() -> nd6_output() -> nd6_output_ifp() -> (whatever)_output() ->
    nd6_storelladdr()

We have ip6_ouput() which calls nd6_output() instead of link output routine.
nd6_output() does the following:
  * checks if lle exists, creates it if needed (similar to arpresolve())
  * performes lle state transitions (similar to arpresolve())
  * calls nd6_output_ifp() which pushes packets to link output routine along
    with running SeND/MAC hooks regardless of lle state
    (e.g. works as run-hooks placeholder).

After that, iface output routine like ether_output() calls nd6_storelladdr()
  which performs lle lookup once again.

As a result, we perform lookup twice for each outgoing packet for most types
  of interfaces. We also need to maintain runtime-checked table of 'nd6-free'
  interfaces (see nd6_need_cache()).

Fix this behavior by eliminating first ND lookup. To be more specific:
  * make all nd6_output() consumers use nd6_output_ifp() instead
  * rename nd6_output[_slow]() to nd6_resolve_[slow]()
  * convert nd6_resolve() and nd6_resolve_slow() to arpresolve() semantics,
    e.g. copy L2 address to buffer instead of pushing packet towards lower
    layers
  * Make all nd6_storelladdr() users use nd6_resolve()
  * eliminate nd6_storelladdr()

The resulting callchain is the following:
  ip6_output() -> nd6_output_ifp() -> (whatever)_output() -> nd6_resolve()

Error handling:
Currently sending packet to non-existing la results in ip6_<output|forward>
  -> nd6_output() -> nd6_output _lle() which returns 0.
In new scenario packet is propagated to <ether|whatever>_output() ->
  nd6_resolve() which will return EWOULDBLOCK, and that result
  will be converted to 0.

(And EWOULDBLOCK is actually used by IB/TOE code).

Sponsored by:		Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D1469
2015-09-16 14:26:28 +00:00
melifaro
daa0d6c584 Constantify lookup key in several nd6_* functions. 2015-09-16 11:06:07 +00:00
melifaro
f6e576f283 Simplify nd6_cache_lladdr:
* Move isRouter calculation code to separate nd6_is_router() function.
* Make nd6_cache_lladdr() return void: its return value hasn't been used
  since r53541 KAME import in 1999.

Sponsored by:	Yandex LLC
2015-09-15 17:16:31 +00:00
melifaro
5ad1f2444d * Do more fine-grained locking: call eventhandlers/free_entry
without holding afdata wlock
* convert per-af delete_address callback to global lltable_delete_entry() and
  more low-level "delete this lle" per-af callback
* fix some bugs/inconsistencies in IPv4/IPv6 ifscrub procedures

Sponsored by:		Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D3573
2015-09-14 16:48:19 +00:00
melifaro
e31cc5ffc6 Do not pass lle to nd6_ns_output(). Use newly-added
nd6_llinfo_get_holdsrc() to extract desired IPv6 source
  from holdchain and pass it to the nd6_ns_output().
2015-09-05 14:14:03 +00:00
melifaro
54b3b78856 * Split allocation and table linking for lle's.
Before that, the logic besides lle_create() was the following:
  return existing if found, create if not. This behaviour was error-prone
  since we had to deal with 'sudden' static<>dynamic lle changes.
  This commit fixes bunch of different issues like:
  - refcount leak when lle is converted to static.
    Simple check case:
    console 1:
    while true;
      do for i in `arp -an|awk '$4~/incomp/{print$2}'|tr -d '()'`;
        do arp -s $i 00:22:44:66:88:00 ; arp -d $i;
      done;
    done
   console 2:
    ping -f any-dead-host-in-L2
   console 3:
    # watch for memory consumption:
    vmstat -m | awk '$1~/lltable/{print$2}'
  - possible problems in arptimer() / nd6_timer() when dropping/reacquiring
   lock.
  New logic explicitly handles use-or-create cases in every lla_create
  user. Basically, most of the changes are purely mechanical. However,
  we explicitly avoid using existing lle's for interface/static LLE records.
* While here, call lle_event handlers on all real table lle change.
* Create lltable_free_entry() calling existing per-lltable
  lle_free_t callback for entry deletion
2015-08-20 12:05:17 +00:00
melifaro
20bb5966e2 MFP r274553:
* Move lle creation/deletion from lla_lookup to separate functions:
  lla_lookup(LLE_CREATE) -> lla_create
  lla_lookup(LLE_DELETE) -> lla_delete
lla_create now returns with LLE_EXCLUSIVE lock for lle.
* Provide typedefs for new/existing lltable callbacks.

Reviewed by:	ae
2015-08-08 17:48:54 +00:00
hrs
64bd31eb61 - Remove ND6_IFF_IGNORELOOP. This functionality was useless in practice
because a link where looped back NS messages are permanently observed
  does not work with either NDP or ARP for IPv4.

- draft-ietf-6man-enhanced-dad is now RFC 7527.

Discussed with:	hiren
MFC after:	3 days
2015-05-12 03:31:57 +00:00
hrs
218de7f1d6 - Implement loopback probing state in enhanced DAD algorithm.
- Add no_dad and ignoreloop per-IF knob.  no_dad disables DAD completely,
  and ignoreloop is to prevent infinite loop in loopback probing state when
  loopback is permanently expected.
2015-03-05 21:27:49 +00:00
hrs
9d87f6a3c3 Implement Enhanced DAD algorithm for IPv6 described in
draft-ietf-6man-enhanced-dad-13.

This basically adds a random nonce option (RFC 3971) to NS messages
for DAD probe to detect a looped back packet.  This looped back packet
prevented DAD on some pseudo-interfaces which aggregates multiple L2 links
such as lagg(4).

The length of the nonce is set to 6 bytes.  This algorithm can be disabled by
setting net.inet6.ip6.dad_enhanced sysctl to 0 in a per-vnet basis.

Reported by:		hiren
Reviewed by:		ae
Differential Revision:	https://reviews.freebsd.org/D1835
2015-03-02 17:30:26 +00:00
melifaro
abec420f04 * Use newly-created nd6_grab_holdchain() function to retrieve lle
hold mbuf chain instead of calling full-blown nd6_output_lle()
  for each packet. This simplifies both callers and nd6_output_lle()
  implementation.
* Make nd6_output_lle() static and remove now-unused lle and chain
  arguments.
* Rename nd6_output_flush() -> nd6_flush_holdchain() to be consistent.
* Move all pre-send transmit hooks to newly-created nd6_output_ifp().
  Now nd6_output(), nd6_output_lle() and nd6_flush_holdchain() are using
  it to send mbufs to if_output.
* Remove SeND hook from nd6_na_input() because it was implemented
  incorrectly since the beginning (r211501):
  - it tagged initial input mbuf (m) instead of m_hold
  - tagging _all_ mbufs in holdchain seems to be wrong anyway.
2015-01-08 18:02:05 +00:00
markj
f0265d5d83 Add refcounting to IPv6 DAD objects and simplify the DAD code to fix a
number of races which could cause double frees or use-after-frees when
performing DAD on an address. In particular, an IPv6 address can now only be
marked as a duplicate from the DAD callout.

Differential Revision:	https://reviews.freebsd.org/D1258
Reviewed by:		ae, hrs
Reported by:		rstone
MFC after:		1 month
2014-12-08 04:44:40 +00:00
melifaro
95c680b9a3 Do not return unlocked/unreferenced lle in arpresolve/nd6_storelladdr -
return lle flags IFF needed.
Do not pass rte to arpresolve - pass is_gateway flag instead.
2014-11-27 23:06:25 +00:00
melifaro
89eb9b8cc2 * Make nd6_dad_duplicated() constant.
* Simplify refcounting by using nd6_dad_add() / nd6_dad_del().

Reviewed by:	ae
MFC after:	2 weeks
Sponsored by:	Yandex LLC
2014-11-10 16:01:39 +00:00
melifaro
94efd07208 Remove unused 'struct route *' argument from nd6_output_flush(). 2014-11-09 16:20:27 +00:00
melifaro
6ee59753ec Further rework netinet6 address handling code:
* Set ia address/mask values BEFORE attaching to address lists.
Inet6 address assignment is not atomic, so the simplest way to
do this atomically is to fill in ia before attach.
* Validate irfa->ia_addr field before use (we permit ANY sockaddr in old code).
* Do some renamings:
  in6_ifinit -> in6_notify_ifa (interaction with other subsystems is here)
  in6_setup_ifa -> in6_broadcast_ifa (LLE/Multicast/DaD code)
  in6_ifaddloop -> nd6_add_ifa_lle
  in6_ifremloop -> nd6_rem_ifa_lle
* Split working with LLE and route announce code for last two.
Add temporary in6_newaddrmsg() function to mimic current rtsock behaviour.
* Call device SIOCSIFADDR handler IFF we're adding first address.
In IPv4 we have to call it on every address change since ARP record
is installed by arp_ifinit() which is called by given handler.
IPv6 stack, on the opposite is responsible to call nd6_add_ifa_lle() so
there is no reason to call SIOCSIFADDR often.
2014-01-19 16:07:27 +00:00
glebius
b4bc270e8f Add const qualifier to the dst parameter of the ifnet if_output method. 2013-04-26 12:50:32 +00:00
ume
e33acd92c3 Add no_prefer_iface option.
It stops treating the address on the interface as special by source
address selection rule even when the interface is outgoing interface.
This is desired in some situation.

Requested by:	hrs
Reviewed by:	IHANet folks including hrs
MFC after:	1 week
2013-01-09 18:18:08 +00:00
delphij
3948ce713c Remove __P.
Submitted by:	kevlo
Reviewed by:	md5(1)
MFC after:	2 months
2012-10-22 21:49:56 +00:00
hrs
43a17c6d76 Remove "prefer_source" address selection option. FreeBSD has had an
implementation of RFC 3484 for this purpose for a long time and "prefer_source"
was never implemented actually.  ND6_IFF_PREFER_SOURCE macro is left intact.
2012-07-09 06:21:46 +00:00
bz
bfb18e3280 Mark a couple of file local functions static and stop exporting them.
MFC after:	1 week
2012-01-05 01:14:35 +00:00
jhb
7a0151720c Use queue(3) macros instead of home-rolled versions in several places in
the INET6 code.  This includes retiring the 'ndpr_next' and 'pfr_next'
macros.

Submitted by:	pluknet (earlier version)
Reviewed by:	pluknet
2011-12-29 18:25:18 +00:00
qingli
3b996bbc11 A default route learned from the RAs could be deleted manually
after its installation. This removal may be accidental and can
prevent the default route from being installed in the future if
the associated default router has the best preference. The cause
is the lack of status update in the default router on the state
of its route installation in the kernel FIB. This patch fixes
the described problem.

Reviewed by:	hrs, discussed with hrs
MFC after:	5 days
2011-11-11 23:22:38 +00:00
hrs
4c2206b625 - Accept Router Advertisement messages even when net.inet6.ip6.forwarding=1.
- A new per-interface knob IFF_ND6_NO_RADR and sysctl IPV6CTL_NO_RADR.
  This controls if accepting a route in an RA message as the default route.
  The default value for each interface can be set by net.inet6.ip6.no_radr.
  The system wide default value is 0.

- A new sysctl: net.inet6.ip6.norbit_raif.  This controls if setting R-bit in
  NA on RA accepting interfaces.  The default is 0 (R-bit is set based on
  net.inet6.ip6.forwarding).

Background:

 IPv6 host/router model suggests a router sends an RA and a host accepts it for
 router discovery.  Because of that, KAME implementation does not allow
 accepting RAs when net.inet6.ip6.forwarding=1.  Accepting RAs on a router can
 make the routing table confused since it can change the default router
 unintentionally.

 However, in practice there are cases where we cannot distinguish a host from
 a router clearly.  For example, a customer edge router often works as a host
 against the ISP, and as a router against the LAN at the same time.  Another
 example is a complex network configurations like an L2TP tunnel for IPv6
 connection to Internet over an Ethernet link with another native IPv6 subnet.
 In this case, the physical interface for the native IPv6 subnet works as a
 host, and the pseudo-interface for L2TP works as the default IP forwarding
 route.

Problem:

 Disabling processing RA messages when net.inet6.ip6.forwarding=1 and
 accepting them when net.inet6.ip6.forward=0 cause the following practical
 issues:

 - A router cannot perform SLAAC.  It becomes a problem if a box has
   multiple interfaces and you want to use SLAAC on some of them, for
   example.  A customer edge router for IPv6 Internet access service
   using an IPv6-over-IPv6 tunnel sometimes needs SLAAC on the
   physical interface for administration purpose; updating firmware
   and so on (link-local addresses can be used there, but GUAs by
   SLAAC are often used for scalability).

 - When a host has multiple IPv6 interfaces and it receives multiple RAs on
   them, controlling the default route is difficult.  Router preferences
   defined in RFC 4191 works only when the routers on the links are
   under your control.

Details of Implementation Changes:

 Router Advertisement messages will be accepted even when
 net.inet6.ip6.forwarding=1.  More precisely, the conditions are as
 follow:

 (ACCEPT_RTADV && !NO_RADR && !ip6.forwarding)
	=> Normal RA processing on that interface. (as IPv6 host)

 (ACCEPT_RTADV && (NO_RADR || ip6.forwarding))
	=> Accept RA but add the router to the defroute list with
	   rtlifetime=0 unconditionally.  This effectively prevents
	   from setting the received router address as the box's
	   default route.

 (!ACCEPT_RTADV)
	=> No RA processing on that interface.

 ACCEPT_RTADV and NO_RADR are per-interface knob.  In short, all interface
 are classified as "RA-accepting" or not.  An RA-accepting interface always
 processes RA messages regardless of ip6.forwarding.  The difference caused by
 NO_RADR or ip6.forwarding is whether the RA source address is considered as
 the default router or not.

 R-bit in NA on the RA accepting interfaces is set based on
 net.inet6.ip6.forwarding.  While RFC 6204 W-1 rule (for CPE case) suggests
 a router should disable the R-bit completely even when the box has
 net.inet6.ip6.forwarding=1, I believe there is no technical reason with
 doing so.  This behavior can be set by a new sysctl net.inet6.ip6.norbit_raif
 (the default is 0).

Usage:

 # ifconfig fxp0 inet6 accept_rtadv
	=> accept RA on fxp0
 # ifconfig fxp0 inet6 accept_rtadv no_radr
	=> accept RA on fxp0 but ignore default route information in it.
 # sysctl net.inet6.ip6.norbit_no_radr=1
	=> R-bit in NAs on RA accepting interfaces will always be set to 0.
2011-06-06 02:14:23 +00:00
bz
0a90ef1728 MFP4: @176978-176982, 176984, 176990-176994, 177441
"Whitspace" churn after the VIMAGE/VNET whirls.

Remove the need for some "init" functions within the network
stack, like pim6_init(), icmp_init() or significantly shorten
others like ip6_init() and nd6_init(), using static initialization
again where possible and formerly missed.

Move (most) variables back to the place they used to be before the
container structs and VIMAGE_GLOABLS (before r185088) and try to
reduce the diff to stable/7 and earlier as good as possible,
to help out-of-tree consumers to update from 6.x or 7.x to 8 or 9.

This also removes some header file pollution for putatively
static global variables.

Revert VIMAGE specific changes in ipfilter::ip_auth.c, that are
no longer needed.

Reviewed by:	jhb
Discussed with:	rwatson
Sponsored by:	The FreeBSD Foundation
Sponsored by:	CK Software GmbH
MFC after:	6 days
2010-04-29 11:52:42 +00:00
hrs
2eb62239d7 Improve flexibility of receiving Router Advertisement and
automatic link-local address configuration:

- Convert a sysctl net.inet6.ip6.accept_rtadv to one for the
  default value of a per-IF flag ND6_IFF_ACCEPT_RTADV, not a
  global knob.  The default value of the sysctl is 0.

- Add a new per-IF flag ND6_IFF_AUTO_LINKLOCAL and convert a
  sysctl net.inet6.ip6.auto_linklocal to one for its default
  value.  The default value of the sysctl is 1.

- Make ND6_IFF_IFDISABLED more robust.  It can be used to disable
  IPv6 functionality of an interface now.

- Receiving RA is allowed if ip6_forwarding==0 *and*
  ND6_IFF_ACCEPT_RTADV is set on that interface.  The former
  condition will be revisited later to support a "host + router" box
  like IPv6 CPE router.  The current behavior is compatible with
  the older releases of FreeBSD.

- The ifconfig(8) now supports these ND6 flags as well as "nud",
  "prefer_source", and "disabled" in ndp(8).  The ndp(8) now
  supports "auto_linklocal".

Discussed with:	bz and jinmei
Reviewed by:	bz
MFC after:	3 days
2009-09-12 22:08:20 +00:00
rwatson
88f8de4d40 Remove unused VNET_SET() and related macros; only VNET_GET() is
ever actually used.  Rename VNET_GET() to VNET() to shorten
variable references.

Discussed with:	bz, julian
Reviewed by:	bz
Approved by:	re (kensmith, kib)
2009-07-16 21:13:04 +00:00
rwatson
57ca4583e7 Build on Jeff Roberson's linker-set based dynamic per-CPU allocator
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator.  Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...).  This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack.  Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory.  Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy.  Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address.  When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by:  bz
Reviewed by:            bz, zec
Discussed with:         gnn, jamie, jeff, jhb, julian, sam
Suggested by:           peter
Approved by:            re (kensmith)
2009-07-14 22:48:30 +00:00
zec
8b1f38241a Introduce an infrastructure for dismantling vnet instances.
Vnet modules and protocol domains may now register destructor
functions to clean up and release per-module state.  The destructor
mechanisms can be triggered by invoking "vimage -d", or a future
equivalent command which will be provided via the new jail framework.

While this patch introduces numerous placeholder destructor functions,
many of those are currently incomplete, thus leaking memory or (even
worse) failing to stop all running timers.  Many of such issues are
already known and will be incrementaly fixed over the next weeks in
smaller incremental commits.

Apart from introducing new fields in structs ifnet, domain, protosw
and vnet_net, which requires the kernel and modules to be rebuilt, this
change should have no impact on nooptions VIMAGE builds, since vnet
destructors can only be called in VIMAGE kernels.  Moreover,
destructor functions should be in general compiled in only in
options VIMAGE builds, except for kernel modules which can be safely
kldunloaded at run time.

Bump __FreeBSD_version to 800097.
Reviewed by:	bz, julian
Approved by:	rwatson, kib (re), julian (mentor)
2009-06-08 17:15:40 +00:00
kmacy
24b38efdce Change if_output to take a struct route as its fourth argument in order
to allow passing a cached struct llentry * down to L2

Reviewed by:	rwatson
2009-04-16 20:30:28 +00:00
qingli
c6a0a000ca in6_clsroute() was applied to prefix routes causing some
of them to expire. in6_clsroute() was only applied to
cloned routes that are no longer applicable after the
arp-v2 commit.
2008-12-17 10:03:49 +00:00