As we invalidate the inetpeer tree along with the routing cache now,
we don't need a genid to reset the redirect handling when the routing
cache is flushed.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We initialize the routing metrics with the values cached on the
inetpeer in rt_init_metrics(). So if we have the metrics cached on the
inetpeer, we ignore the user configured fib_metrics.
To fix this issue, we replace the old tree with a fresh initialized
inet_peer_base. The old tree is removed later with a delayed work queue.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the future the ipv4/ipv6 route gateway will take on two types
of values:
1) INADDR_ANY/IN6ADDR_ANY, for local network routes, and in this case
the neighbour must be obtained using the destination address in
ipv4/ipv6 header as the lookup key.
2) Everything else, the actual nexthop route address.
So if the gateway is not inaddr-any we use it, otherwise we must use
the packet's destination address.
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
net/bluetooth/l2cap_core.c
Just two overlapping changes, one added an initialization of
a local variable, and another change added a new local variable.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 2c8cec5c10 (ipv4: Cache learned PMTU information in inetpeer)
removed IP route cache garbage collector a bit too soon, as this gc was
responsible for expired routes cleanup, releasing their neighbour
reference.
As pointed out by Robert Gladewitz, recent kernels can fill and exhaust
their neighbour cache.
Reintroduce the garbage collection, since we'll have to wait our
neighbour lookups become refcount-less to not depend on this stuff.
Reported-by: Robert Gladewitz <gladewitz@gmx.de>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To reflect the fact that a refrence is not obtained to the
resulting neighbour entry.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Roland Dreier <roland@purestorage.com>
If ipv4_valdiate_peer() fails during a cached entry lookup,
we'll NULL derer since the loop iterator assumes rth is not
NULL.
Letting this be handled as a failure is just bogus, so just make it
not fail. If we have trouble getting a non-NULL neighbour for the
redirected gateway, just restore the original gateway and continue.
The very next use of this cached route will try again.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
__mkroute_output fails to work with the original tos
and uses value with stripped RTO_ONLINK bit. Make sure we put
the original TOS bits into rt_key_tos because it used to match
cached route.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Otherwise we won't notice the peer GENID change.
Reported-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of instantiating an entire new neigh_table instance
just for ATM handling, use the neigh device private facility.
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit f2c31e32b3 (fix NULL dereferences in check_peer_redir()),
dst_get_neighbour() should be guarded by rcu_read_lock() /
rcu_read_unlock() section.
Reported-by: Miles Lane <miles.lane@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now inetpeer is the place where we cache redirect information for ipv4
destinations, we must be able to invalidate informations when a route is
added/removed on host.
As inetpeer is not yet namespace aware, this patch adds a shared
redirect_genid, and a per inetpeer redirect_genid. This might be changed
later if inetpeer becomes ns aware.
Cache information for one inerpeer is valid as long as its
redirect_genid has the same value than global redirect_genid.
Reported-by: Arkadiusz Miśkiewicz <a.miskiewicz@gmail.com>
Tested-by: Arkadiusz Miśkiewicz <a.miskiewicz@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The pmtu informations on the inetpeer are visible for output and
input routes. On packet forwarding, we might propagate a learned
pmtu to the sender. As we update the pmtu informations of the
inetpeer on demand, the original sender of the forwarded packets
might never notice when the pmtu to that inetpeer increases.
So use the mtu of the outgoing device on packet forwarding instead
of the pmtu to the final destination.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We move all mtu handling from dst_mtu() down to the protocol
layer. So each protocol can implement the mtu handling in
a different manner.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We plan to invoke the dst_opt->default_mtu() method unconditioally
from dst_mtu(). So rename the method to dst_opt->mtu() to match
the name with the new meaning.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As it is, we return null as the default mtu of blackhole routes.
This may lead to a propagation of a bogus pmtu if the default_mtu
method of a blackhole route is invoked. So return dst->dev->mtu
as the default mtu instead.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit f39925dbde (ipv4: Cache learned redirect information in
inetpeer.) introduced a regression in ICMP redirect handling.
It assumed ipv4_dst_check() would be called because all possible routes
were attached to the inetpeer we modify in ip_rt_redirect(), but thats
not true.
commit 7cc9150ebe (route: fix ICMP redirect validation) tried to fix
this but solution was not complete. (It fixed only one route)
So we must lookup existing routes (including different TOS values) and
call check_peer_redir() on them.
Reported-by: Ivan Zahariev <famzah@icdsoft.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As we update the learned pmtu informations on demand, we might
report a nagative expiration time value to userspace if the
pmtu informations are already expired and we have not send a
packet to that inetpeer after expiration. With this patch we
send a expire time of null to userspace after expiration
until the next packet is send to that inetpeer.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In func ipv4_dst_check,check_peer_pmtu should be called only when peer is updated.
So,if the peer is not updated in ip_rt_frag_needed,we can not inc __rt_peer_genid.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The commit f39925dbde
(ipv4: Cache learned redirect information in inetpeer.)
removed some ICMP packet validations which are required by
RFC 1122, section 3.2.2.2:
...
A Redirect message SHOULD be silently discarded if the new
gateway address it specifies is not on the same connected
(sub-) net through which the Redirect arrived [INTRO:2,
Appendix A], or if the source of the Redirect is not the
current first-hop gateway for the specified destination (see
Section 3.3.1).
Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
removing obsoleted sysctl,
ip_rt_gc_interval variable no longer used since 2.6.38
Signed-off-by: Vasily Averin <vvs@sw.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
RCU api had been completed and rcu_access_pointer() or
rcu_dereference_protected() are better than generic
rcu_dereference_raw()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As rt_iif represents input device even for packets
coming from loopback with output route, it is not an unique
key specific to input routes. Now rt_route_iif has such role,
it was fl.iif in 2.6.38, so better to change the checks at
some places to save CPU cycles and to restore 2.6.38 semantics.
compare_keys:
- input routes: only rt_route_iif matters, rt_iif is same
- output routes: only rt_oif matters, rt_iif is not
used for matching in __ip_route_output_key
- now we are back to 2.6.38 state
ip_route_input_common:
- matching rt_route_iif implies input route
- compared to 2.6.38 we eliminated one rth->fl.oif check
because it was not needed even for 2.6.38
compare_hash_inputs:
Only the change here is not an optimization, it has
effect only for output routes. I assume I'm restoring
the original intention to ignore oif, it was using fl.iif
- now we are back to 2.6.38 state
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
compare_keys and ip_route_input_common rely on
rt_oif for distinguishing of input and output routes
with same keys values. But sometimes the input route has
also same hash chain (keyed by iif != 0) with the output
routes (keyed by orig_oif=0). Problem visible if running
with small number of rhash_entries.
Fix them to use rt_route_iif instead. By this way
input route can not be returned to users that request
output route.
The patch fixes the ip_rt_bug errors that were
reported in ip_local_out context, mostly for 255.255.255.255
destinations.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.
MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)
Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation. So the periodic
regeneration and 8-bit counter have been removed. We compute and
use a full 32-bit sequence number.
For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.
Reported-by: Dan Kaminsky <dan@doxpara.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Gergely Kalman reported crashes in check_peer_redir().
It appears commit f39925dbde (ipv4: Cache learned redirect
information in inetpeer.) added a race, leading to possible NULL ptr
dereference.
Since we can now change dst neighbour, we should make sure a reader can
safely use a neighbour.
Add RCU protection to dst neighbour, and make sure check_peer_redir()
can be called safely by different cpus in parallel.
As neighbours are already freed after one RCU grace period, this patch
should not add typical RCU penalty (cache cold effects)
Many thanks to Gergely for providing a pretty report pointing to the
bug.
Reported-by: Gergely Kalman <synapse@hippy.csoma.elte.hu>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rt_tos was changed to iph->tos but it must be filtered by RT_TOS
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the future dst entries will be neigh-less. In that environment we
need to have an easy transition point for current users of
dst->neighbour outside of the packet output fast path.
Signed-off-by: David S. Miller <davem@davemloft.net>
It's just taking on one of two possible values, either
neigh_ops->output or dev_queue_xmit(). And this is purely depending
upon whether nud_state has NUD_CONNECTED set or not.
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that there is a one-to-one correspondance between neighbour
and hh_cache entries, we no longer need:
1) dynamic allocation
2) attachment to dst->hh
3) refcounting
Initialization of the hh_cache entry is indicated by hh_len
being non-zero, and such initialization is always done with
the neighbour's lock held as a writer.
Signed-off-by: David S. Miller <davem@davemloft.net>
Get rid of all of the useless and costly indirection
by doing the neigh hash table lookup directly inside
of the neighbour binding.
Rename from arp_bind_neighbour to rt_bind_neighbour.
Use new helpers {__,}ipv4_neigh_lookup()
In rt_bind_neighbour() get rid of useless tests which
are never true in the context this function is called,
namely dev is never NULL and the dst->neighbour is
always NULL.
Signed-off-by: David S. Miller <davem@davemloft.net>
Make the case labels the same indent as the switch.
git diff -w shows no difference.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Knut Tidemann found that first packet of a multicast flow was not
correctly received, and bisected the regression to commit b23dd4fe42
(Make output route lookup return rtable directly.)
Special thanks to Knut, who provided a very nice bug report, including
sample programs to demonstrate the bug.
Reported-and-bisectedby: Knut Tidemann <knut.andre.tidemann@jotron.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The message size allocated for rtnl ifinfo dumps was limited to
a single page. This is not enough for additional interface info
available with devices that support SR-IOV and caused a bug in
which VF info would not be displayed if more than approximately
40 VFs were created per interface.
Implement a new function pointer for the rtnl_register service that will
calculate the amount of data required for the ifinfo dump and allocate
enough data to satisfy the request.
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
commit 2c8cec5c10 (ipv4: Cache learned PMTU information in inetpeer)
added some racy peer->pmtu_expires accesses.
As its value can be changed by another cpu/thread, we should be more
careful, reading its value once.
Add peer_pmtu_expired() and peer_pmtu_cleaned() helpers
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a stack backtrace to the ip_rt_bug path for debugging
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It's way past it's usefulness. And this gets rid of a bunch
of stray ->rt_{dst,src} references.
Even the comment documenting the macro was inaccurate (stated
default was 1 when it's 0).
If reintroduced, it should be done properly, with dynamic debug
facilities.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass in the sk_buff so that we can fetch the necessary keys from
the packet header when working with input routes.
Signed-off-by: David S. Miller <davem@davemloft.net>
To more accurately reflect that it is purely a routing
cache lookup key and is used in no other context.
Signed-off-by: David S. Miller <davem@davemloft.net>
Slow path output route resolution always makes sure that
->{saddr,daddr} are set, and also if we trigger into IPSEC resolution
we initialize them as well, because xfrm_lookup() expects them to be
fully resolved.
But if we hit the fast path and flowi4->flowi4_proto is zero, we won't
do this initialization.
Therefore, move the IPSEC path initialization to the route cache
lookup fast path to make sure these are always set.
Signed-off-by: David S. Miller <davem@davemloft.net>
Make dst_alloc() and it's users explicitly initialize the entire
entry.
The zero'ing done by kmem_cache_zalloc() was almost entirely
redundant.
Signed-off-by: David S. Miller <davem@davemloft.net>
Resolved logic conflicts causing a build failure due to
drivers/net/r8169.c changes using a patch from Stephen Rothwell.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fib_select_default() is a complete NOP, and completely pointless
to invoke, when we have no more than 1 default route installed.
And this is far and away the common case.
So remember how many prefixlen==0 routes we have in the routing
table, and elide the call when we have no more than one of those.
This cuts output route creation time by 157 cycles on Niagara2+.
In order to add the new int to fib_table, we have to correct the type
of ->tb_data[] to unsigned long, otherwise the private area will be
unaligned on 64-bit systems.
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (34 commits)
net: Add support for SMSC LAN9530, LAN9730 and LAN89530
mlx4_en: Restoring RX buffer pointer in case of failure
mlx4: Sensing link type at device initialization
ipv4: Fix "Set rt->rt_iif more sanely on output routes."
MAINTAINERS: add entry for Xen network backend
be2net: Fix suspend/resume operation
be2net: Rename some struct members for clarity
pppoe: drop PPPOX_ZOMBIEs in pppoe_flush_dev
dsa/mv88e6131: add support for mv88e6085 switch
ipv6: Enable RFS sk_rxhash tracking for ipv6 sockets (v2)
be2net: Fix a potential crash during shutdown.
bna: Fix for handling firmware heartbeat failure
can: mcp251x: Allow pass IRQ flags through platform data.
smsc911x: fix mac_lock acquision before calling smsc911x_mac_read
iwlwifi: accept EEPROM version 0x423 for iwl6000
rt2x00: fix cancelling uninitialized work
rtlwifi: Fix some warnings/bugs
p54usb: IDs for two new devices
wl12xx: fix potential buffer overflow in testmode nvs push
zd1211rw: reset rx idle timer from tasklet
...
This makes sk_buff available for other use in fib_validate_source().
Signed-off-by: Michael Smith <msmith@cbnco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 1018b5c016 ("Set rt->rt_iif more
sanely on output routes.") breaks rt_is_{output,input}_route.
This became the cause to return "IP_PKTINFO's ->ipi_ifindex == 0".
To fix it, this does:
1) Add "int rt_route_iif;" to struct rtable
2) For input routes, always set rt_route_iif to same value as rt_iif
3) For output routes, always set rt_route_iif to zero. Set rt_iif
as it is done currently.
4) Change rt_is_{output,input}_route() to test rt_route_iif
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Any operation that:
1) Brings up an interface
2) Adds an IP address to an interface
3) Deletes an IP address from an interface
can potentially invalidate the nh_saddr value, requiring
it to be recomputed.
Perform the recomputation lazily using a generation ID.
Reported-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 2c8cec5c10 (Cache learned PMTU information in inetpeer) added
an extra inet_putpeer() call in ip_rt_update_pmtu().
This results in various problems, since we can free one inetpeer, while
it is still in use.
Ref: http://www.spinics.net/lists/netdev/msg159121.html
Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ECN support incorrectly maps ECN BESTEFFORT packets to TC_PRIO_FILLER
(1) instead of TC_PRIO_BESTEFFORT (0)
This means ECN enabled flows are placed in pfifo_fast/prio low priority
band, giving ECN enabled flows [ECT(0) and CE codepoints] higher drop
probabilities.
This is rather unfortunate, given we would like ECN being more widely
used.
Ref : http://www.coverfire.com/archives/2011/03/13/pfifo_fast-and-ecn/
Signed-off-by: Dan Siemon <dan@coverfire.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dave Täht <d@taht.net>
Cc: Jonathan Morton <chromatix99@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On current net-next-2.6, when Linux receives ICMP Type: 3, Code: 4
(Destination unreachable (Fragmentation needed)),
icmp_unreach
-> ip_rt_frag_needed
(peer->pmtu_expires is set here)
-> tcp_v4_err
-> do_pmtu_discovery
-> ip_rt_update_pmtu
(peer->pmtu_expires is already set,
so check_peer_pmtu is skipped.)
-> check_peer_pmtu
check_peer_pmtu is skipped and MTU is not updated.
To fix this, let check_peer_pmtu execute unconditionally.
And some minor fixes
1) Avoid potential peer->pmtu_expires set to be zero.
2) In check_peer_pmtu, argument of time_before is reversed.
3) check_peer_pmtu expects peer->pmtu_orig is initialized as zero,
but not initialized.
Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To start doing these conversions, we need to add some temporary
flow4_* macros which will eventually go away when all the protocol
code paths are changed to work on AF specific flowi objects.
Signed-off-by: David S. Miller <davem@davemloft.net>
I intend to turn struct flowi into a union of AF specific flowi
structs. There will be a common structure that each variant includes
first, much like struct sock_common.
This is the first step to move in that direction.
Signed-off-by: David S. Miller <davem@davemloft.net>
All callers are under rcu_read_lock() protection already.
Rename to ip_check_mc_rcu() to make it even more clear.
Signed-off-by: David S. Miller <davem@davemloft.net>
Like in commit 44713b67db
("ipv4: Optimize flow initialization in output route lookup."
we can optimize the on-stack flow setup to only initialize
the members which are actually used.
Otherwise we bzero the entire structure, then initialize
explicitly the first half of it.
Signed-off-by: David S. Miller <davem@davemloft.net>
The only necessary parts are the src/dst addresses, the
interface indexes, the TOS, and the mark.
The rest is unnecessary bloat, which amounts to nearly
50 bytes on 64-bit.
Signed-off-by: David S. Miller <davem@davemloft.net>
rt->rt_iif is only ever inspected on input routes, for example DCCP
uses this to populate a route lookup flow key when generating replies
to another packet.
Therefore, setting it to anything other than zero on output routes
makes no sense.
Signed-off-by: David S. Miller <davem@davemloft.net>
We burn a lot of useless cycles, cpu store buffer traffic, and
memory operations memset()'ing the on-stack flow used to perform
output route lookups in __ip_route_output_key().
Only the first half of the flow object members even matter for
output route lookups in this context, specifically:
FIB rules matching cares about:
dst, src, tos, iif, oif, mark
FIB trie lookup cares about:
dst
FIB semantic match cares about:
tos, scope, oif
Therefore only initialize these specific members and elide the
memset entirely.
On Niagara2 this kills about ~300 cycles from the output route
lookup path.
Likely, we can take things further, since all callers of output
route lookups essentially throw away the on-stack flow they use.
So they don't care if we use it as a scratch-pad to compute the
final flow key.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Commit 0dbaee3b37 (net: Abstract default ADVMSS behind an
accessor.) introduced a possible crash in tcp_connect_init(), when
dst->default_advmss() is called from dst_metric_advmss()
Reported-by: George Spelvin <linux@horizon.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The only troublesome bit here is __mkroute_output which wants
to override res->fi and res->type, compute those in local
variables instead.
Signed-off-by: David S. Miller <davem@davemloft.net>
This allows avoiding multiple writes to the initial __refcnt.
The most simplest cases of wanting an initial reference of "1"
in ipv4 and ipv6 have been converted, the rest have been left
along and kept at the existing "0".
Signed-off-by: David S. Miller <davem@davemloft.net>
This also allows us to combine all the dst->flags settings and avoid
read/modify/write sequences to this struct member.
Signed-off-by: David S. Miller <davem@davemloft.net>
There's a lot of redundancy and unnecessary stack frames
in the output route creation path.
1) Make __mkroute_output() return error pointers.
2) Eliminate ip_mkroute_output() entirely, made possible by #1.
3) Call __mkroute_output() directly and handling the returning error
pointers in ip_route_output_slow().
Signed-off-by: David S. Miller <davem@davemloft.net>
Note that we do not generate the redirect netevent any longer,
because we don't create a new cached route.
Instead, once the new neighbour is bound to the cached route,
we emit a neigh update event instead.
Signed-off-by: David S. Miller <davem@davemloft.net>
The general idea is that if we learn new PMTU information, we
bump the peer genid.
This triggers the dst_ops->check() code to validate and if
necessary propagate the new PMTU value into the metrics.
Learned PMTU information self-expires.
This means that it is not necessary to kill a cached route
entry just because the PMTU information is too old.
As a consequence:
1) When the path appears unreachable (dst_ops->link_failure
or dst_ops->negative_advice) we unwind the PMTU state if
it is out of date, instead of killing the cached route.
A redirected route will still be invalidated in these
situations.
2) rt_check_expire(), rt_worker_func(), et al. are no longer
necessary at all.
Signed-off-by: David S. Miller <davem@davemloft.net>
If we didn't have a routing cache, we would not be able to properly
propagate certain kinds of dynamic path attributes, for example
PMTU information and redirects.
The reason is that if we didn't have a routing cache, then there would
be no way to lookup all of the active cached routes hanging off of
sockets, tunnels, IPSEC bundles, etc.
Consider the case where we created a cached route, but no inetpeer
entry existed and also we were not asked to pre-COW the route metrics
and therefore did not force the creation a new inetpeer entry.
If we later get a PMTU message, or a redirect, and store this
information in a new inetpeer entry, there is no way to teach that
cached route about the newly existing inetpeer entry.
The facilities implemented here handle this problem.
First we create a generation ID. When we create a cached route of any
kind, we remember the generation ID at the time of attachment. Any
time we force-create an inetpeer entry in response to new path
information, we bump that generation ID.
The dst_ops->check() callback is where the knowledge of this event
is propagated. If the global generation ID does not equal the one
stored in the cached route, and the cached route has not attached
to an inetpeer yet, we look it up and attach if one is found. Now
that we've updated the cached route's information, we update the
route's generation ID too.
This clears the way for implementing PMTU and redirects directly in
the inetpeer cache. There is absolutely no need to consult cached
route information in order to maintain this information.
At this point nothing bumps the inetpeer genids, that comes in the
later changes which handle PMTUs and redirects using inetpeers.
Signed-off-by: David S. Miller <davem@davemloft.net>
Like metrics, the ICMP rate limiting bits are cached state about
a destination. So move it into the inet_peer entries.
If an inet_peer cannot be bound (the reason is memory allocation
failure or similar), the policy is to allow.
Signed-off-by: David S. Miller <davem@davemloft.net>
Always lookup to see if we have an existing inetpeer entry for
a route. Let FLOWI_FLAG_PRECOW_METRICS merely influence the
"create" argument to rt_bind_peer().
Also, call rt_bind_peer() unconditionally since it is not
possible for rt->peer to be non-NULL at this point.
Signed-off-by: David S. Miller <davem@davemloft.net>
Both fib_trie and fib_hash have a local implementation of
fib_table_select_default(). This is completely unnecessary
code duplication.
Since we now remember the fib_table and the head of the fib
alias list of the default route, we can implement one single
generic version of this routine.
Looking at the fib_hash implementation you may get the impression
that it's possible for there to be multiple top-level routes in
the table for the default route. The truth is, it isn't, the
insert code will only allow one entry to exist in the zero
prefix hash table, because all keys evaluate to zero and all
keys in a hash table must be unique.
Signed-off-by: David S. Miller <davem@davemloft.net>
When an IPSEC SA is still being set up, __xfrm_lookup() will return
-EREMOTE and so ip_route_output_flow() will return a blackhole route.
This can happen in a sndmsg call, and after d33e455337 ("net: Abstract
default MTU metric calculation behind an accessor.") this leads to a
crash in ip_append_data() because the blackhole dst_ops have no
default_mtu() method and so dst_mtu() calls a NULL pointer.
Fix this by adding default_mtu() methods (that simply return 0, matching
the old behavior) to the blackhole dst_ops.
The IPv4 part of this patch fixes a crash that I saw when using an IPSEC
VPN; the IPv6 part is untested because I don't have an IPv6 VPN, but it
looks to be needed as well.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The fib metric memory in this case is static in the kernel image,
so we don't need to reference count it since it's never going
to go away on us.
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP is going to record metrics for the connection,
so pre-COW the route metrics at route cache entry
creation time.
This avoids several atomic operations that have to
occur if we COW the metrics after the entry reaches
global visibility.
Signed-off-by: David S. Miller <davem@davemloft.net>
Please note that the IPSEC dst entry metrics keep using
the generic metrics COW'ing mechanism using kmalloc/kfree.
This gives the IPSEC routes an opportunity to use metrics
which are unique to their encapsulated paths.
Signed-off-by: David S. Miller <davem@davemloft.net>
Routing metrics are now copy-on-write.
Initially a route entry points it's metrics at a read-only location.
If a routing table entry exists, it will point there. Else it will
point at the all zero metric place-holder called 'dst_default_metrics'.
The writeability state of the metrics is stored in the low bits of the
metrics pointer, we have two bits left to spare if we want to store
more states.
For the initial implementation, COW is implemented simply via kmalloc.
However future enhancements will change this to place the writable
metrics somewhere else, in order to increase sharing. Very likely
this "somewhere else" will be the inetpeer cache.
Note also that this means that metrics updates may transiently fail
if we cannot COW the metrics successfully.
But even by itself, this patch should decrease memory usage and
increase cache locality especially for routing workloads. In those
cases the read-only metric copies stay in place and never get written
to.
TCP workloads where metrics get updated, and those rare cases where
PMTU triggers occur, will take a very slight performance hit. But
that hit will be alleviated when the long-term writable metrics
move to a more sharable location.
Since the metrics storage went from a u32 array of RTAX_MAX entries to
what is essentially a pointer, some retooling of the dst_entry layout
was necessary.
Most importantly, we need to preserve the alignment of the reference
count so that it doesn't share cache lines with the read-mostly state,
as per Eric Dumazet's alignment assertion checks.
The only non-trivial bit here is the move of the 'flags' member into
the writeable cacheline. This is OK since we are always accessing the
flags around the same moment when we made a modification to the
reference count.
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix dependencies of netfilter realm match: it depends on NET_CLS_ROUTE,
which itself depends on NET_SCHED; this dependency is missing from netfilter.
Since matching on realms is also useful without having NET_SCHED enabled and
the option really only controls whether the tclassid member is included in
route and dst entries, rename the config option to IP_ROUTE_CLASSID and move
it outside of traffic scheduling context to get rid of the NET_SCHED dependeny.
Reported-by: Vladis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
The preferred source address is currently ignored for local routes,
which results in all local connections having a src address that is the
same as the local dst address. Fix this by respecting the preferred source
address when it is provided for local routes.
This bug can be demonstrated as follows:
# ifconfig dummy0 192.168.0.1
# ip route show table local | grep local.*dummy0
local 192.168.0.1 dev dummy0 proto kernel scope host src 192.168.0.1
# ip route change table local local 192.168.0.1 dev dummy0 \
proto kernel scope host src 127.0.0.1
# ip route show table local | grep local.*dummy0
local 192.168.0.1 dev dummy0 proto kernel scope host src 127.0.0.1
We now establish a local connection and verify the source IP
address selection:
# nc -l 192.168.0.1 3128 &
# nc 192.168.0.1 3128 &
# netstat -ant | grep 192.168.0.1:3128.*EST
tcp 0 0 192.168.0.1:3128 192.168.0.1:33228 ESTABLISHED
tcp 0 0 192.168.0.1:33228 192.168.0.1:3128 ESTABLISHED
Signed-off-by: Joel Sing <jsing@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In ip_route_output_slow(), instead of allowing a route to be created on
a not UPed device, report -ENETUNREACH immediately.
# ip tunnel add mode ipip remote 10.16.0.164 local
10.16.0.72 dev eth0
# (Note : tunl1 is down)
# ping -I tunl1 10.1.2.3
PING 10.1.2.3 (10.1.2.3) from 192.168.18.5 tunl1: 56(84) bytes of data.
(nothing)
# ./a.out tunl1
# ip tunnel del tunl1
Message from syslogd@shelby at Dec 22 10:12:08 ...
kernel: unregister_netdevice: waiting for tunl1 to become free.
Usage count = 3
After patch:
# ping -I tunl1 10.1.2.3
connect: Network is unreachable
Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Flush the routing cache only of entries that match the
network namespace in which the purge event occurred.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Like RTAX_ADVMSS, make the default calculation go through a dst_ops
method rather than caching the computation in the routing cache
entries.
Now dst metrics are pretty much left as-is when new entries are
created, thus optimizing metric sharing becomes a real possibility.
Signed-off-by: David S. Miller <davem@davemloft.net>
Make all RTAX_ADVMSS metric accesses go through a new helper function,
dst_metric_advmss().
Leave the actual default metric as "zero" in the real metric slot,
and compute the actual default value dynamically via a new dst_ops
AF specific callback.
For stacked IPSEC routes, we use the advmss of the path which
preserves existing behavior.
Unlike ipv4/ipv6, DecNET ties the advmss to the mtu and thus updates
advmss on pmtu updates. This inconsistency in advmss handling
results in more raw metric accesses than I wish we ended up with.
Signed-off-by: David S. Miller <davem@davemloft.net>
Always go through a new ip4_dst_hoplimit() helper, just like ipv6.
This allowed several simplifications:
1) The interim dst_metric_hoplimit() can go as it's no longer
userd.
2) The sysctl_ip_default_ttl entry no longer needs to use
ipv4_doint_and_flush, since the sysctl is not cached in
routing cache metrics any longer.
3) ipv4_doint_and_flush no longer needs to be exported and
therefore can be marked static.
When ipv4_doint_and_flush_strategy was removed some time ago,
the external declaration in ip.h was mistakenly left around
so kill that off too.
We have to move the sysctl_ip_default_ttl declaration into
ipv4's route cache definition header net/route.h, because
currently net/ip.h (where the declaration lives now) has
a back dependency on net/route.h
Signed-off-by: David S. Miller <davem@davemloft.net>
Use helper functions to hide all direct accesses, especially writes,
to dst_entry metrics values.
This will allow us to:
1) More easily change how the metrics are stored.
2) Implement COW for metrics.
In particular this will help us put metrics into the inetpeer
cache if that is what we end up doing. We can make the _metrics
member a pointer instead of an array, initially have it point
at the read-only metrics in the FIB, and then on the first set
grab an inetpeer entry and point the _metrics member there.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Use the macros defined for the members of flowi to clean the code up.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we test rt->fl.iif against zero, we're seeing if it's
an output or an input route.
Make that explicit with some helper functions.
Signed-off-by: David S. Miller <davem@davemloft.net>
It seems idev field in struct rtable has no special purpose, but adding
extra atomic ops.
We hold refcounts on the device itself (using percpu data, so pretty
cheap in current kernel).
infiniband case is solved using dst.dev instead of idev->dev
Removal of this field means routing without route cache is now using
shared data, percpu data, and only potential contention is a pair of
atomic ops on struct neighbour per forwarded packet.
About 5% speedup on routing test.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add __rcu annotations to :
(struct dst_entry)->rt_next
(struct rt_hash_bucket)->chain
And use appropriate rcu primitives to reduce sparse warnings if
CONFIG_SPARSE_RCU_POINTER=y
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no point using RCU for dst we allocate for a very short time
(used once).
Change dst_release() to take DST_NOCACHE into account, but also change
skb_dst_set_noref() to force a refcount increment for such dst.
This is a _huge_ gain, because we dont waste memory to store xx thousand
of dsts. Instead of queueing them to RCU, we can free them instantly.
CPU caches can stay hot, re-using same memory blocks to hold temporary
dsts.
Note : remove unneeded smp_mb__before_atomic_dec(); in dst_release(),
since atomic_dec_return() implies a full memory barrier.
Stress test, 160.000.000 udp frames sent, IP route cache disabled
(DDOS).
Before:
real 0m38.091s
user 0m13.189s
sys 7m53.018s
After:
real 0m29.946s
user 0m12.157s
sys 7m40.605s
For reference, if IP route cache was enabled :
real 0m32.030s
user 0m10.521s
sys 8m15.243s
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change a few checks against the hardcoded broadcast address,
0xffffffff, to ipv4_is_lbcast(). Remove some existing checks
using ipv4_is_lbcast() that are now obviously superfluous.
Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct dst_ops tracks number of allocated dst in an atomic_t field,
subject to high cache line contention in stress workload.
Switch to a percpu_counter, to reduce number of time we need to dirty a
central location. Place it on a separate cache line to avoid dirtying
read only fields.
Stress test :
(Sending 160.000.000 UDP frames,
IP route cache disabled, dual E5540 @2.53GHz,
32bit kernel, FIB_TRIE, SLUB/NUMA)
Before:
real 0m51.179s
user 0m15.329s
sys 10m15.942s
After:
real 0m45.570s
user 0m15.525s
sys 9m56.669s
With a small reordering of struct neighbour fields, subject of a
following patch, (to separate refcnt from other read mostly fields)
real 0m41.841s
user 0m15.261s
sys 8m45.949s
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit "fib: RCU conversion of fib_lookup()" removed rcu_read_lock() from
__mkroute_output but left a couple of calls to rcu_read_unlock() in there.
This causes lockdep to complain that the rcu_read_unlock() call in
__ip_route_output_key causes a lock inbalance and quickly crashes the
kernel. The below fixes this for me.
Signed-off-by: Dimitris Michailidis <dm@chelsio.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While doing stress tests with IP route cache disabled, and multi queue
devices, I noticed a very high contention on one rwlock used in
neighbour code.
When many cpus are trying to send frames (possibly using a high
performance multiqueue device) to the same neighbour, they fight for the
neigh->lock rwlock in order to call neigh_hh_init(), and fight on
hh->hh_refcnt (a pair of atomic_inc/atomic_dec_and_test())
But we dont need to call neigh_hh_init() for dst that are used only
once. It costs four atomic operations at least, on two contended cache
lines, plus the high contention on neigh->lock rwlock.
Introduce a new dst flag, DST_NOCACHE, that is set when dst was not
inserted in route cache.
With the stress test bench, sending 160000000 frames on one neighbour,
results are :
Before patch:
real 2m28.406s
user 0m11.781s
sys 36m17.964s
After patch:
real 1m26.532s
user 0m12.185s
sys 20m3.903s
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While doing stress tests with a disabled IP route cache, I found
__mkroute_output() was touching three times in_device atomic refcount.
Use RCU to touch it once to reduce cache line ping pongs.
Before patch
time to perform the test
real 1m42.009s
user 0m12.545s
sys 25m0.726s
Profile :
16109.00 26.4% ip_route_output_slow vmlinux
7434.00 12.2% dst_destroy vmlinux
3280.00 5.4% fib_rules_lookup vmlinux
3252.00 5.3% fib_semantic_match vmlinux
2622.00 4.3% fib_table_lookup vmlinux
2535.00 4.1% dst_alloc vmlinux
1750.00 2.9% _raw_read_lock vmlinux
1532.00 2.5% rt_set_nexthop vmlinux
After patch
real 1m36.503s
user 0m12.977s
sys 23m25.608s
14234.00 22.4% ip_route_output_slow vmlinux
8717.00 13.7% dst_destroy vmlinux
4052.00 6.4% fib_rules_lookup vmlinux
3951.00 6.2% fib_semantic_match vmlinux
3191.00 5.0% dst_alloc vmlinux
1764.00 2.8% fib_table_lookup vmlinux
1692.00 2.7% _raw_read_lock vmlinux
1605.00 2.5% rt_set_nexthop vmlinux
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv4 and IPv6 have separate neighbour tables, so
the warning messages should be distinguishable.
[ Add a suitable message prefix on the ipv4 side as well -DaveM ]
Signed-off-by: Ulrich Weber <uweber@astaro.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
__in_dev_get_rtnl(dev_out) is called while RTNL is not held, thus
triggers a lockdep fault.
At this point, we only perform a raw test of dev_out->ip_ptr being NULL,
we dont need to make sure ip_ptr cant changed right after.
We can use rcu_dereference_raw() for this.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change "return (EXPR);" to "return EXPR;"
return is not a function, parentheses are not required.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Blackhole routes are used when xfrm_lookup() returns -EREMOTE (error
triggered by IKE for example), hence this kind of route is always
temporary and so we should check if a better route exists for next
packets.
Bug has been introduced by commit d11a4dc18b.
Signed-off-by: Jianzhao Wang <jianzhao.wang@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now cmpxchg() is available on all arches, we can use it in
build_ehash_secret() and rt_bind_peer() instead of using spinlocks.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new rt attribute, RTA_MARK, and use it in
rt_fill_info()/inet_rtm_getroute() to support following commands :
ip route get 192.168.20.110 mark NUMBER
ip route get 192.168.20.108 from 192.168.20.110 iif eth1 mark NUMBER
ip route list cache [192.168.20.110] mark NUMBER
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
CodingStyle cleanups
EXPORT_SYMBOL should immediately follow the symbol declaration.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Addition of rcu_head to struct inet_peer added 16bytes on 64bit arches.
Thats a bit unfortunate, since old size was exactly 64 bytes.
This can be solved, using an union between this rcu_head an four fields,
that are normally used only when a refcount is taken on inet_peer.
rcu_head is used only when refcnt=-1, right before structure freeing.
Add a inet_peer_refcheck() function to check this assertion for a while.
We can bring back SLAB_HWCACHE_ALIGN qualifier in kmem cache creation.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
remove useless union keyword in rtable, rt6_info and dn_route.
Since there is only one member in a union, the union keyword isn't useful.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
in_dev_get() -> __in_dev_get_rcu() in a rcu protected function.
[ Fix build with CONFIG_IP_ROUTE_VERBOSE disabled. -DaveM ]
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Avoid two atomic ops on output device refcount
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Avoid two atomic ops on struct in_device refcount per incoming packet,
if slow path taken, (or route cache disabled)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Christoph Lameter mentioned that packets could be dropped in input path
because of rp_filter settings, without any SNMP counter being
incremented. System administrator can have a hard time to track the
problem.
This patch introduces a new counter, LINUX_MIB_IPRPFILTER, incremented
each time we drop a packet because Reverse Path Filter triggers.
(We receive an IPv4 datagram on a given interface, and find the route to
send an answer would use another interface)
netstat -s | grep IPReversePathFilter
IPReversePathFilter: 21714
Reported-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch saves 224 bytes of text on my machine.
__this_cpu_inc() generates a single instruction, using no scratch
registers :
65 ff 04 25 a8 30 01 00 incl %gs:0x130a8
instead of :
48 c7 c2 80 30 01 00 mov $0x13080,%rdx
65 48 8b 04 25 88 ea 00 00 mov %gs:0xea88,%rax
83 44 10 28 01 addl $0x1,0x28(%rax,%rdx,1)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ip_route_input() is the version returning a refcounted dst, while
ip_route_input_noref() returns a non refcounted one.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
