Commit Graph

113 Commits

Author SHA1 Message Date
markj
f0215c1068 Do not perform DAD on stf(4) interfaces.
stf(4) interfaces are not multicast-capable so they can't perform DAD.
They also did not set IFF_DRV_RUNNING when an address was assigned, so
the logic in nd6_timer() would periodically flag such an address as
tentative, resulting in interface flapping.

Fix the problem by setting IFF_DRV_RUNNING when an address is assigned,
and do some related cleanup:
- In in6if_do_dad(), remove a redundant check for !UP || !RUNNING.
  There is only one caller in the tree, and it only looks at whether
  the return value is non-zero.
- Have in6if_do_dad() return false if the interface is not
  multicast-capable.
- Set ND6_IFF_NO_DAD when an address is assigned to an stf(4) interface
  and the interface goes UP as a result. Note that this is not
  sufficient to fix the problem because the new address is marked as
  tentative and DAD is started before in6_ifattach() is called.
  However, setting no_dad is formally correct.
- Change nd6_timer() to not flag addresses as tentative if no_dad is
  set.

This is based on a patch from Viktor Dukhovni.

Reported by:	Viktor Dukhovni <ietf-dane@dukhovni.org>
Reviewed by:	ae
MFC after:	3 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D19751
2019-03-30 18:00:44 +00:00
eugen
e425bdf9f7 Prevent stf(4) from panicing due to unprotected access to INADDR_HASH.
PR:			220078
MFC after:		1 month
Differential Revision:	https://reviews.freebsd.org/D12457
Tested-by:		Cassiano Peixoto and others
2018-10-27 04:45:28 +00:00
ae
dfbd18b5fe Rework IP encapsulation handling code.
Currently it has several disadvantages:
- it uses single mutex to protect internal structures. It is used by
  data- and control- path, thus there are no parallelism at all.
- it uses single list to keep encap handlers for both INET and INET6
  families.
- struct encaptab keeps unneeded information (src, dst, masks, protosw),
  that isn't used by code in the source tree.
- matches are prioritized and when many tunneling interfaces are
  registered, encapcheck handler of each interface is invoked for each
  packet. The search takes O(n) for n interfaces. All this work is done
  with exclusive lock held.

What this patch includes:
- the datapath is converted to be lockless using epoch(9) KPI.
- struct encaptab now linked using CK_LIST.
- all unused fields removed from struct encaptab. Several new fields
  addedr: min_length is the minimum packet length, that encapsulation
  handler expects to see; exact_match is maximum number of bits, that
  can return an encapsulation handler, when it wants to consume a packet.
- IPv6 and IPv4 handlers are stored in separate lists;
- added new "encap_lookup_t" method, that will be used later. It is
  targeted to speedup lookup of needed interface, when gif(4)/gre(4) have
  many interfaces.
- the need to use protosw structure is eliminated. The only pr_input
  method was used from this structure, so I don't see the need to keep
  using it.
- encap_input_t method changed to avoid using mbuf tags to store softc
  pointer. Now it is passed directly trough encap_input_t method.
  encap_getarg() funtions is removed.
- all sockaddr structures and code that uses them removed. We don't have
  any code in the tree that uses them. All consumers use encap_attach_func()
  method, that relies on invoking of encapcheck() to determine the needed
  handler.
- introduced struct encap_config, it contains parameters of encap handler
  that is going to be registered by encap_attach() function.
- encap handlers are stored in lists ordered by exact_match value, thus
  handlers that need more bits to match will be checked first, and if
  encapcheck method returns exact_match value, the search will be stopped.
- all current consumers changed to use new KPI.

Reviewed by:	mmacy
Sponsored by:	Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D15617
2018-06-05 20:51:01 +00:00
mmacy
0db6398617 net: fix set but not used 2018-05-19 05:27:49 +00:00
mmacy
7aeac9ef18 ifnet: Replace if_addr_lock rwlock with epoch + mutex
Run on LLNW canaries and tested by pho@

gallatin:
Using a 14-core, 28-HTT single socket E5-2697 v3 with a 40GbE MLX5
based ConnectX 4-LX NIC, I see an almost 12% improvement in received
packet rate, and a larger improvement in bytes delivered all the way
to userspace.

When the host receiving 64 streams of netperf -H $DUT -t UDP_STREAM -- -m 1,
I see, using nstat -I mce0 1 before the patch:

InMpps OMpps  InGbs  OGbs err TCP Est %CPU syscalls csw     irq GBfree
4.98   0.00   4.42   0.00 4235592     33   83.80 4720653 2149771   1235 247.32
4.73   0.00   4.20   0.00 4025260     33   82.99 4724900 2139833   1204 247.32
4.72   0.00   4.20   0.00 4035252     33   82.14 4719162 2132023   1264 247.32
4.71   0.00   4.21   0.00 4073206     33   83.68 4744973 2123317   1347 247.32
4.72   0.00   4.21   0.00 4061118     33   80.82 4713615 2188091   1490 247.32
4.72   0.00   4.21   0.00 4051675     33   85.29 4727399 2109011   1205 247.32
4.73   0.00   4.21   0.00 4039056     33   84.65 4724735 2102603   1053 247.32

After the patch

InMpps OMpps  InGbs  OGbs err TCP Est %CPU syscalls csw     irq GBfree
5.43   0.00   4.20   0.00 3313143     33   84.96 5434214 1900162   2656 245.51
5.43   0.00   4.20   0.00 3308527     33   85.24 5439695 1809382   2521 245.51
5.42   0.00   4.19   0.00 3316778     33   87.54 5416028 1805835   2256 245.51
5.42   0.00   4.19   0.00 3317673     33   90.44 5426044 1763056   2332 245.51
5.42   0.00   4.19   0.00 3314839     33   88.11 5435732 1792218   2499 245.52
5.44   0.00   4.19   0.00 3293228     33   91.84 5426301 1668597   2121 245.52

Similarly, netperf reports 230Mb/s before the patch, and 270Mb/s after the patch

Reviewed by:	gallatin
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D15366
2018-05-18 20:13:34 +00:00
pfg
4736ccfd9c sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00
loos
9d6de9853e Remove the unused mutex since r273220.
MFC after:	1 week
Sponsored by:	Rubicon Communications, LLC (Netgate)
2017-07-28 04:41:57 +00:00
ae
a968322d07 Remove now unneded cast. 2017-03-08 08:09:41 +00:00
loos
eaa049158f The stf(4) interface name does not conform with the default naming
convention for interfaces, because only one stf(4) interface can exist
in the system.

This disallow the use of unit numbers different than 0, however, it is
possible to create the clone without specify the unit number (wildcard).

In the wildcard case we must update the interface name before return.

This fix an infinite recursion in pf code that keeps track of network
interfaces and groups:

1 - a group for the cloned type of the interface is added (stf in this
    case);
2 - the system will now try to add an interface named stf (instead of
    stf0) to stf group;
3 - when pfi_kif_attach() tries to search for an already existing 'stf'
    interface, the 'stf' group is returned and thus the group is added
    as an interface of itself;

This will now cause a crash at the first attempt to traverse the groups
which the stf interface belongs (which loops over itself).

Obtained from:	pfSense
MFC after:	2 weeks
Sponsored by:	Rubicon Communications, LLC (Netgate)
2017-01-29 18:41:09 +00:00
melifaro
2d94c81db6 Convert if_stf(4) to new routing api. 2015-12-16 09:18:20 +00:00
ae
e9ba3ff9a6 Ansify if_stf.c 2015-07-31 09:04:22 +00:00
ae
6895fa8542 Build if_stf(4) module only when both INET and INET6 support are enabled. 2015-07-30 10:26:43 +00:00
ae
75425458ac Convert in_ifaddr_lock and in6_ifaddr_lock to rmlock.
Both are used to protect access to IP addresses lists and they can be
acquired for reading several times per packet. To reduce lock contention
it is better to use rmlock here.

Reviewed by:	gnn (previous version)
Obtained from:	Yandex LLC
Sponsored by:	Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D3149
2015-07-29 08:12:05 +00:00
ae
d6158111f9 Remove if_stf.h. It contains only one function declaration used by if_stf(4).
Also make in_stf_protosw structure static.
2014-12-23 20:54:59 +00:00
ae
3e1d0ef3ba Remove unneded check. No need to do m_pullup to the size that we prepended.
MFC after:	1 week
Sponsored by:	Yandex LLC
2014-12-02 05:41:03 +00:00
melifaro
11af63037f Make checks for rt_mtu generic:
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
2014-11-06 13:13:09 +00:00
melifaro
80a1a77bec * Remove route caching in if_stf.
* Copy necessary in6_ifa on stack instead of playing with refcounts.
2014-10-17 15:07:04 +00:00
glebius
f2cafe032f Mechanically convert to if_inc_counter(). 2014-09-19 10:39:58 +00:00
kevlo
dd40fa7e62 Change pr_output's prototype to avoid the need for explicit casts.
This is a follow up to r269699.

Phabric:	D564
Reviewed by:	jhb
2014-08-15 02:43:02 +00:00
kevlo
7727a3c215 Merge 'struct ip6protosw' and 'struct protosw' into one. Now we have
only one protocol switch structure that is shared between ipv4 and ipv6.

Phabric:	D476
Reviewed by:	jhb
2014-08-08 01:57:15 +00:00
hselasky
35b126e324 Pull in r267961 and r267973 again. Fix for issues reported will follow. 2014-06-28 03:56:17 +00:00
gjb
fc21f40567 Revert r267961, r267973:
These changes prevent sysctl(8) from returning proper output,
such as:

 1) no output from sysctl(8)
 2) erroneously returning ENOMEM with tools like truss(1)
    or uname(1)
 truss: can not get etype: Cannot allocate memory
2014-06-27 22:05:21 +00:00
hselasky
bd1ed65f0f Extend the meaning of the CTLFLAG_TUN flag to automatically check if
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.

Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.

MFC after:	2 weeks
Sponsored by:	Mellanox Technologies
2014-06-27 16:33:43 +00:00
glebius
8a3e4bbebb - Remove rt_metrics_lite and simply put its members into rtentry.
- Use counter(9) for rt_pksent (former rt_rmx.rmx_pksent). This
  removes another cache trashing ++ from packet forwarding path.
- Create zini/fini methods for the rtentry UMA zone. Via initialize
  mutex and counter in them.
- Fix reporting of rmx_pksent to routing socket.
- Fix netstat(1) to report "Use" both in kvm(3) and sysctl(3) mode.

The change is mostly targeted for stable/10 merge. For head,
rt_pksent is expected to just disappear.

Discussed with:		melifaro
Sponsored by:		Netflix
Sponsored by:		Nginx, Inc.
2014-03-05 01:17:47 +00:00
glebius
ff6e113f1b The r48589 promised to remove implicit inclusion of if_var.h soon. Prepare
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2013-10-26 17:58:36 +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
ae
f89408c03e Add an ability to set net.link.stf.permit_rfc1918 from the loader.
MFC after:	2 weeks
2012-12-27 21:26:08 +00:00
ae
6064718574 Add net.link.stf.permit_rfc1918 sysctl variable. It can be used to allow
the use of private IPv4 addresses with stf(4).

MFC after:	2 weeks
2012-12-27 20:59:22 +00:00
glebius
8e20fa5ae9 Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually
2012-12-05 08:04:20 +00:00
glebius
5cc3ac5902 Switch the entire IPv4 stack to keep the IP packet header
in network byte order. Any host byte order processing is
done in local variables and host byte order values are
never[1] written to a packet.

  After this change a packet processed by the stack isn't
modified at all[2] except for TTL.

  After this change a network stack hacker doesn't need to
scratch his head trying to figure out what is the byte order
at the given place in the stack.

[1] One exception still remains. The raw sockets convert host
byte order before pass a packet to an application. Probably
this would remain for ages for compatibility.

[2] The ip_input() still subtructs header len from ip->ip_len,
but this is planned to be fixed soon.

Reviewed by:	luigi, Maxim Dounin <mdounin mdounin.ru>
Tested by:	ray, Olivier Cochard-Labbe <olivier cochard.me>
2012-10-22 21:09:03 +00:00
glebius
05f24a6b77 Make the "struct if_clone" opaque to users of the cloning API. Users
now use function calls:

  if_clone_simple()
  if_clone_advanced()

to initialize a cloner, instead of macros that initialize if_clone
structure.

Discussed with:		brooks, bz, 1 year ago
2012-10-16 13:37:54 +00:00
kevlo
ceb08698f2 Revert previous commit...
Pointyhat to:	kevlo (myself)
2012-10-10 08:36:38 +00:00
kevlo
8747a46991 Prefer NULL over 0 for pointers 2012-10-09 08:27:40 +00:00
jhb
8f6ba08bcc Unexpand a couple of TAILQ_FOREACH()s. 2012-08-17 16:01:24 +00:00
melifaro
497943ec39 Permit changing MTU in 6to4 relay.
This behavior is recommended by RFC 4213 clause 3.2.

Sometimes fragmentation is the least evil.
For example, some Linux IPVS kernels forwards
ICMPv6 checksums to real servers incorrectly.

Reviewed by:      hrs(previous version)
Approved by:      kib(mentor)
MFC after:        1 week
2012-07-15 17:44:27 +00:00
ed
0c56cf839d Mark all SYSCTL_NODEs static that have no corresponding SYSCTL_DECLs.
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
2011-11-07 15:43:11 +00:00
bz
300a95bf76 Tag mbufs of all incoming frames or packets with the interface's FIB
setting (either default or if supported as set by SIOCSIFFIB, e.g.
from ifconfig).

Submitted by:	Alexander V. Chernikov (melifaro ipfw.ru)
Reviewed by:	julian
MFC after:	2 weeks
2011-07-03 16:08:38 +00:00
sobomax
213eac1f2c Add new tunable 'net.link.ifqmaxlen' to set default send interface
queue length. The default value for this parameter is 50, which is
quite low for many of today's uses and the only way to modify this
parameter right now is to edit if_var.h file. Also add read-only
sysctl with the same name, so that it's possible to retrieve the
current value.

MFC after:	1 month
2010-05-03 07:32:50 +00:00
rwatson
fb9ffed650 Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks.  Minor cleanups are done in the process,
and comments updated to reflect these changes.

Reviewed by:	bz
Approved by:	re (vimage blanket)
2009-08-01 19:26:27 +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
rwatson
3dffb5419c Update if_stf and if_tun to use if_addr_rlock()/if_addr_runlock() rather
than IF_ADDR_LOCK()/IF_ADDR_UNLOCK() when iterating ifp->if_addrhead.

MFC after:	6 weeks
2009-06-26 00:45:20 +00:00
rwatson
ea70a3542d Add a new global rwlock, in_ifaddr_lock, which will synchronize use of the
in_ifaddrhead and INADDR_HASH address lists.

Previously, these lists were used unsynchronized as they were effectively
never changed in steady state, but we've seen increasing reports of
writer-writer races on very busy VPN servers as core count has gone up
(and similar configurations where address lists change frequently and
concurrently).

For the time being, use rwlocks rather than rmlocks in order to take
advantage of their better lock debugging support.  As a result, we don't
enable ip_input()'s read-locking of INADDR_HASH until an rmlock conversion
is complete and a performance analysis has been done.  This means that one
class of reader-writer races still exists.

MFC after:      6 weeks
Reviewed by:    bz
2009-06-25 11:52:33 +00:00
rwatson
5972c25713 Make stf_getsrcifa6() return a reference to an in6_ifaddr rather than
a pointer, and dispose of the references when no longer needed.

MFC after:	6 weeks
2009-06-24 08:52:09 +00:00
rwatson
f4934662e5 Move "options MAC" from opt_mac.h to opt_global.h, as it's now in GENERIC
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.

Discussed with:	pjd
2009-06-05 14:55:22 +00:00
rwatson
d15e84d3bf Prefer ifa_link (structure field) to ifa_list (macro alias for it).
MFC after:	2 weeks
2009-04-20 22:41:19 +00:00
rwatson
dd96787bc7 Prefer if_addrhead (FreeBSD) to if_addrlist (BSD compat) naming for the
interface address list in if_stf.c.

Acquire interface address list locks around address list access.

MFC after:	2 months
2009-04-20 20:09:55 +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
bz
604d89458a Rather than using hidden includes (with cicular dependencies),
directly include only the header files needed. This reduces the
unneeded spamming of various headers into lots of files.

For now, this leaves us with very few modules including vnet.h
and thus needing to depend on opt_route.h.

Reviewed by:	brooks, gnn, des, zec, imp
Sponsored by:	The FreeBSD Foundation
2008-12-02 21:37:28 +00:00
zec
8797d4caec Step 1.5 of importing the network stack virtualization infrastructure
from the vimage project, as per plan established at devsummit 08/08:
http://wiki.freebsd.org/Image/Notes200808DevSummit

Introduce INIT_VNET_*() initializer macros, VNET_FOREACH() iterator
macros, and CURVNET_SET() context setting macros, all currently
resolving to NOPs.

Prepare for virtualization of selected SYSCTL objects by introducing a
family of SYSCTL_V_*() macros, currently resolving to their global
counterparts, i.e. SYSCTL_V_INT() == SYSCTL_INT().

Move selected #defines from sys/sys/vimage.h to newly introduced header
files specific to virtualized subsystems (sys/net/vnet.h,
sys/netinet/vinet.h etc.).

All the changes are verified to have zero functional impact at this
point in time by doing MD5 comparision between pre- and post-change
object files(*).

(*) netipsec/keysock.c did not validate depending on compile time options.

Implemented by:	julian, bz, brooks, zec
Reviewed by:	julian, bz, brooks, kris, rwatson, ...
Approved by:	julian (mentor)
Obtained from:	//depot/projects/vimage-commit2/...
X-MFC after:	never
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
2008-10-02 15:37:58 +00:00
dwmalone
af76980ef5 Some people's 6to4 routers seem to have been blowing up because of
the unlocked route caching in if_stf. Add a mutex that protects
access to cached route. This seemed to fix problems for Pekka Savola.

Nick Sayer had similar problems, and in his case completly disabling
the route cache seemed to help. Add a sysctl net.link.stf.route_cache
that can be used to turn off route caching in if_stf.

PR:		122283
MFC after:	2 weeks
Tested by:	Pekka Savola, Nick Sayer.
2008-09-25 12:35:01 +00:00