RAW sockets with hdrinc suffer from contention on rt_uncached_lock
spinlock.
One solution is to use percpu lists, since most routes are destroyed
by the cpu that created them.
It is unclear why we even have to put these routes in uncached_list,
as all outgoing packets should be freed when a device is dismantled.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: caacf05e5a ("ipv4: Properly purge netdev references on uncached routes.")
Signed-off-by: David S. Miller <davem@davemloft.net>
ip_rt_dump do nothing after IPv4 route caches removal, so we can remove it.
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While forwarding we should not use the protocol path mtu to calculate
the mtu for a forwarded packet but instead use the interface mtu.
We mark forwarded skbs in ip_forward with IPSKB_FORWARDED, which was
introduced for multicast forwarding. But as it does not conflict with
our usage in unicast code path it is perfect for reuse.
I moved the functions ip_sk_accept_pmtu, ip_sk_use_pmtu and ip_skb_dst_mtu
along with the new ip_dst_mtu_maybe_forward to net/ip.h to fix circular
dependencies because of IPSKB_FORWARDED.
Because someone might have written a software which does probe
destinations manually and expects the kernel to honour those path mtus
I introduced a new per-namespace "ip_forward_use_pmtu" knob so someone
can disable this new behaviour. We also still use mtus which are locked on a
route for forwarding.
The reason for this change is, that path mtus information can be injected
into the kernel via e.g. icmp_err protocol handler without verification
of local sockets. As such, this could cause the IPv4 forwarding path to
wrongfully emit fragmentation needed notifications or start to fragment
packets along a path.
Tunnel and ipsec output paths clear IPCB again, thus IPSKB_FORWARDED
won't be set and further fragmentation logic will use the path mtu to
determine the fragmentation size. They also recheck packet size with
help of path mtu discovery and report appropriate errors.
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: John Heffner <johnwheffner@gmail.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
FLOWI_FLAG_CAN_SLEEP was used to notify xfrm about the posibility
to sleep until the needed states are resolved. This code is gone,
so FLOWI_FLAG_CAN_SLEEP is not needed anymore.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Sockets marked with IP_PMTUDISC_INTERFACE won't do path mtu discovery,
their sockets won't accept and install new path mtu information and they
will always use the interface mtu for outgoing packets. It is guaranteed
that the packet is not fragmented locally. But we won't set the DF-Flag
on the outgoing frames.
Florian Weimer had the idea to use this flag to ensure DNS servers are
never generating outgoing fragments. They may well be fragmented on the
path, but the server never stores or usees path mtu values, which could
well be forged in an attack.
(The root of the problem with path MTU discovery is that there is
no reliable way to authenticate ICMP Fragmentation Needed But DF Set
messages because they are sent from intermediate routers with their
source addresses, and the IMCP payload will not always contain sufficient
information to identify a flow.)
Recent research in the DNS community showed that it is possible to
implement an attack where DNS cache poisoning is feasible by spoofing
fragments. This work was done by Amir Herzberg and Haya Shulman:
<https://sites.google.com/site/hayashulman/files/fragmentation-poisoning.pdf>
This issue was previously discussed among the DNS community, e.g.
<http://www.ietf.org/mail-archive/web/dnsext/current/msg01204.html>,
without leading to fixes.
This patch depends on the patch "ipv4: fix DO and PROBE pmtu mode
regarding local fragmentation with UFO/CORK" for the enforcement of the
non-fragmentable checks. If other users than ip_append_page/data should
use this semantic too, we have to add a new flag to IPCB(skb)->flags to
suppress local fragmentation and check for this in ip_finish_output.
Many thanks to Florian Weimer for the idea and feedback while implementing
this patch.
Cc: David S. Miller <davem@davemloft.net>
Suggested-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Half of the rt_cache_stat fields are no longer used after IP
route cache removal, lets shrink this per cpu area.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If IP_TOS or IP_TTL are specified as ancillary data, then sendmsg() sends out
packets with the specified TTL or TOS overriding the socket values specified
with the traditional setsockopt().
The struct inet_cork stores the values of TOS, TTL and priority that are
passed through the struct ipcm_cookie. If there are user-specified TOS
(tos != -1) or TTL (ttl != 0) in the struct ipcm_cookie, these values are
used to override the per-socket values. In case of TOS also the priority
is changed accordingly.
Two helper functions get_rttos and get_rtconn_flags are defined to take
into account the presence of a user specified TOS value when computing
RT_TOS and RT_CONN_FLAGS.
Signed-off-by: Francesco Fusco <ffusco@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are a mix of function prototypes with and without extern
in the kernel sources. Standardize on not using extern for
function prototypes.
Function prototypes don't need to be written with extern.
extern is assumed by the compiler. Its use is as unnecessary as
using auto to declare automatic/local variables in a block.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skb->sk socket can be of AF_INET or AF_INET6 address family. Thus we
always have to make sure we a referring to the correct interpretation
of skb->sk.
We only depend on header defines to query the mtu, so we don't introduce
a new dependency to ipv6 by this change.
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
We can save a test in ip_rt_put(), considering dst_release() accepts
a NULL parameter, and dst is first element in rtable.
Add a BUILD_BUG_ON() to catch any change that could break this
assertion.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Cong Wang <amwang@redhat.com>
Acked-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add new flag to remember when route is via gateway.
We will use it to allow rt_gateway to contain address of
directly connected host for the cases when DST_NOCACHE is
used or when the NH exception caches per-destination route
without DST_NOCACHE flag, i.e. when routes are not used for
other destinations. By this way we force the neighbour
resolving to work with the routed destination but we
can use different address in the packet, feature needed
for IPVS-DR where original packet for virtual IP is routed
via route to real IP.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since route cache deletion (89aef8921b), delay is no
more used. Remove it.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a device is unregistered, we have to purge all of the
references to it that may exist in the entire system.
If a route is uncached, we currently have no way of accomplishing
this.
So create a global list that is scanned when a network device goes
down. This mirrors the logic in net/core/dst.c's dst_ifdown().
Signed-off-by: David S. Miller <davem@davemloft.net>
With the routing cache removal we lost the "noref" code paths on
input, and this can kill some routing workloads.
Reinstate the noref path when we hit a cached route in the FIB
nexthops.
With help from Eric Dumazet.
Reported-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On input packet processing, rt->rt_iif will be zero if we should
use skb->dev->ifindex.
Since we access rt->rt_iif consistently via inet_iif(), that is
the only spot whose interpretation have to adjust.
Signed-off-by: David S. Miller <davem@davemloft.net>
It's not really needed.
We only grabbed a reference to the fib_info for the sake of fib_info
local metrics.
However, fib_info objects are freed using RCU, as are therefore their
private metrics (if any).
We would have triggered a route cache flush if we eliminated a
reference to a fib_info object in the routing tables.
Therefore, any existing cached routes will first check and see that
they have been invalidated before an errant reference to these
metric values would occur.
Signed-off-by: David S. Miller <davem@davemloft.net>
That is this value's only use, as a boolean to indicate whether
a route is an input route or not.
So implement it that way, using a u16 gap present in the struct
already.
Signed-off-by: David S. Miller <davem@davemloft.net>
Never actually used.
It was being set on output routes to the original OIF specified in the
flow key used for the lookup.
Adjust the only user, ipmr_rt_fib_lookup(), for greater correctness of
the flowi4_oif and flowi4_iif values, thanks to feedback from Julian
Anastasov.
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to allow prefixed routes, we have to adjust how rt_gateway
is set and interpreted.
The new interpretation is:
1) rt_gateway == 0, destination is on-link, nexthop is iph->daddr
2) rt_gateway != 0, destination requires a nexthop gateway
Abstract the fetching of the proper nexthop value using a new
inline helper, rt_nexthop(), as suggested by Joe Perches.
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Vijay Subramanian <subramanian.vijay@gmail.com>
They are always used in contexts where they can be reconstituted,
or where the finally resolved rt->rt_{src,dst} is semantically
equivalent.
Signed-off-by: David S. Miller <davem@davemloft.net>
The "noref" argument to ip_route_input_common() is now always ignored
because we do not cache routes, and in that case we must always grab
a reference to the resulting 'dst'.
Signed-off-by: David S. Miller <davem@davemloft.net>
The ipv4 routing cache is non-deterministic, performance wise, and is
subject to reasonably easy to launch denial of service attacks.
The routing cache works great for well behaved traffic, and the world
was a much friendlier place when the tradeoffs that led to the routing
cache's design were considered.
What it boils down to is that the performance of the routing cache is
a product of the traffic patterns seen by a system rather than being a
product of the contents of the routing tables. The former of which is
controllable by external entitites.
Even for "well behaved" legitimate traffic, high volume sites can see
hit rates in the routing cache of only ~%10.
Signed-off-by: David S. Miller <davem@davemloft.net>
No longer needed, as the protocol handlers now all properly
propagate the redirect back into the routing code.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass in the SKB rather than just the IP addresses, so that policy
and other aspects can reside in ip_rt_redirect() rather then
icmp_redirect().
Signed-off-by: David S. Miller <davem@davemloft.net>
No longer needed. TCP writes metrics, but now in it's own special
cache that does not dirty the route metrics. Therefore there is no
longer any reason to pre-cow metrics in this way.
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit c074da2810.
This change has several unwanted side effects:
1) Sockets will cache the DST_NOCACHE route in sk->sk_rx_dst and we'll
thus never create a real cached route.
2) All TCP traffic will use DST_NOCACHE and never use the routing
cache at all.
Signed-off-by: David S. Miller <davem@davemloft.net>
DDOS synflood attacks hit badly IP route cache.
On typical machines, this cache is allowed to hold up to 8 Millions dst
entries, 256 bytes for each, for a total of 2GB of memory.
rt_garbage_collect() triggers and tries to cleanup things.
Eventually route cache is disabled but machine is under fire and might
OOM and crash.
This patch exploits the new TCP early demux, to set a nocache
boolean in case incoming TCP frame is for a not yet ESTABLISHED or
TIMEWAIT socket.
This 'nocache' boolean is then used in case dst entry is not found in
route cache, to create an unhashed dst entry (DST_NOCACHE)
SYN-cookie-ACK sent use a similar mechanism (ipv4: tcp: dont cache
output dst for syncookies), so after this patch, a machine is able to
absorb a DDOS synflood attack without polluting its IP route cache.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With ip_rt_frag_needed() removed, we have to explicitly update PMTU
information in every ICMP error handler.
Create two helper functions to facilitate this.
1) ipv4_sk_update_pmtu()
This updates the PMTU when we have a socket context to
work with.
2) ipv4_update_pmtu()
Raw version, used when no socket context is available. For this
interface, we essentially just pass in explicit arguments for
the flow identity information we would have extracted from the
socket.
And you'll notice that ipv4_sk_update_pmtu() is simply implemented
in terms of ipv4_update_pmtu()
Note that __ip_route_output_key() is used, rather than something like
ip_route_output_flow() or ip_route_output_key(). This is because we
absolutely do not want to end up with a route that does IPSEC
encapsulation and the like. Instead, we only want the route that
would get us to the node described by the outermost IP header.
Reported-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
MAINTAINERS
drivers/net/wireless/iwlwifi/pcie/trans.c
The iwlwifi conflict was resolved by keeping the code added
in 'net' that turns off the buggy chip feature.
The MAINTAINERS conflict was merely overlapping changes, one
change updated all the wireless web site URLs and the other
changed some GIT trees to be Johannes's instead of John's.
Signed-off-by: David S. Miller <davem@davemloft.net>
If no peer actually gets attached (either because create is zero or
the peer allocation fails) we'll trigger a BUG because we
unconditionally do an rt{,6}_peer_ptr() afterwards.
Fix this by guarding it with the proper check.
Signed-off-by: David S. Miller <davem@davemloft.net>
There is zero point to this function.
It's only real substance is to perform an extremely outdated BSD4.2
ICMP check, which we can safely remove. If you really have a MTU
limited link being routed by a BSD4.2 derived system, here's a nickel
go buy yourself a real router.
The other actions of ip_rt_frag_needed(), checking and conditionally
updating the peer, are done by the per-protocol handlers of the ICMP
event.
TCP, UDP, et al. have a handler which will receive this event and
transmit it back into the associated route via dst_ops->update_pmtu().
This simplification is important, because it eliminates the one place
where we do not have a proper route context in which to make an
inetpeer lookup.
Signed-off-by: David S. Miller <davem@davemloft.net>
We encode the pointer(s) into an unsigned long with one state bit.
The state bit is used so we can store the inetpeer tree root to use
when resolving the peer later.
Later the peer roots will be per-FIB table, and this change works to
facilitate that.
Signed-off-by: David S. Miller <davem@davemloft.net>
If I build with W=1, for every file that includes <net/route.h>, I get the warning
include/net/route.h: In function 'ip_route_output':
include/net/route.h:135:3: warning: initialized field overwritten [-Woverride-init]
include/net/route.h:135:3: warning: (near initialization for 'fl4') [-Woverride-init]
(This is with "gcc (Debian 4.6.3-1) 4.6.3")
A fix seems pretty trivial: move the initialization of .flowi4_tos
earlier. As far as I can tell, this has no effect on code generation.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There's a lot of places that open-code rt{,6}_get_peer() only because
they want to set 'create' to one. So add an rt{,6}_get_peer_create()
for their sake.
There were also a few spots open-coding plain rt{,6}_get_peer() and
those are transformed here as well.
Signed-off-by: David S. Miller <davem@davemloft.net>
Use of "unsigned int" is preferred to bare "unsigned" in net tree.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet found that commit 813b3b5db8
(ipv4: Use caller's on-stack flowi as-is in output
route lookups.) that comes in 3.0 added a regression.
The problem appears to be that resulting flowi4_oif is
used incorrectly as input parameter to some routing lookups.
The result is that when connecting to local port without
listener if the IP address that is used is not on a loopback
interface we incorrectly assign RTN_UNICAST to the output
route because no route is matched by oif=lo. The RST packet
can not be sent immediately by tcp_v4_send_reset because
it expects RTN_LOCAL.
So, change ip_route_connect and ip_route_newports to
update the flowi4 fields that are input parameters because
we do not want unnecessary binding to oif.
To make it clear what are the input parameters that
can be modified during lookup and to show which fields of
floiw4 are reused add a new function to update the flowi4
structure: flowi4_update_output.
Thanks to Yurij M. Plotnikov for providing a bug report including a
program to reproduce the problem.
Thanks to Eric Dumazet for tracking the problem down to
tcp_v4_send_reset and providing initial fix.
Reported-by: Yurij M. Plotnikov <Yurij.Plotnikov@oktetlabs.ru>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
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>
First, make callers pass on-stack flowi4 to ip_route_output_gre()
so they can get at the fully resolved flow key.
Next, use that in ipgre_tunnel_xmit() to avoid the need to use
rt->rt_{dst,src}.
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>
Now that output route lookups update the flow with
source address et al. selections, the fl4->{saddr,daddr}
assignments here are no longer necessary.
Signed-off-by: David S. Miller <davem@davemloft.net>
It's not used by anything in the kernel, and defined in net/route.h so
never exported to userspace.
Therefore we can safely remove it.
Signed-off-by: David S. Miller <davem@davemloft.net>
These functions are used together as a unit for route resolution
during connect(). They address the chicken-and-egg problem that
exists when ports need to be allocated during connect() processing,
yet such port allocations require addressing information from the
routing code.
It's currently more heavy handed than it needs to be, and in
particular we allocate and initialize a flow object twice.
Let the callers provide the on-stack flow object. That way we only
need to initialize it once in the ip_route_connect() call.
Later, if ip_route_newports() needs to do anything, it re-uses that
flow object as-is except for the ports which it updates before the
route re-lookup.
Also, describe why this set of facilities are needed and how it works
in a big comment.
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
These header files are never installed to user consumption, so any
__KERNEL__ cpp checks are superfluous.
Projects should also not copy these files into their userland utility
sources and try to use them there. If they insist on doing so, the
onus is on them to sanitize the headers as needed.
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>
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>
When we set up the flow informations in ip_route_newports(), we take
the address informations from the the rt_key_src and rt_key_dst fields
of the rtable. They appear to be empty. So take the address
informations from rt_src and rt_dst instead. This issue was introduced
by commit 5e2b61f784 ("ipv4: Remove
flowi from struct rtable.")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Alex Sidorenko reported for problems with local
routes left after IP addresses are deleted. It happens
when same IPs are used in more than one subnet for the
device.
Fix fib_del_ifaddr to restrict the checks for duplicate
local and broadcast addresses only to the IFAs that use
our primary IFA or another primary IFA with same address.
And we expect the prefsrc to be matched when the routes
are deleted because it is possible they to differ only by
prefsrc. This patch prevents local and broadcast routes
to be leaked until their primary IP is deleted finally
from the box.
As the secondary address promotion needs to delete
the routes for all secondaries that used the old primary IFA,
add option to ignore these secondaries from the checks and
to assume they are already deleted, so that we can safely
delete the route while these IFAs are still on the device list.
Reported-by: Alex Sidorenko <alexandre.sidorenko@hp.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Create two sets of port member accessors, one set prefixed by fl4_*
and the other prefixed by fl6_*
This will let us to create AF optimal flow instances.
It will work because every context in which we access the ports,
we have to be fully aware of which AF the flowi is anyways.
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>
The idea here is this minimizes the number of places one has to edit
in order to make changes to how flows are defined and used.
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>
ip_route_newports() is the only place in the entire kernel that
cares about the port members in the routing cache entry's lookup
flow key.
Therefore the only reason we store an entire flow inside of the
struct rtentry is for this one special case.
Rewrite ip_route_newports() such that:
1) The caller passes in the original port values, so we don't need
to use the rth->fl.fl_ip_{s,d}port values to remember them.
2) The lookup flow is constructed by hand instead of being copied
from the routing cache entry's flow.
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>
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>
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>
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>
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 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>
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>
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>
Add __percpu sparse annotations to net.
These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors. This patch doesn't affect normal builds.
The macro and type tricks around snmp stats make things a bit
interesting. DEFINE/DECLARE_SNMP_STAT() macros mark the target field
as __percpu and SNMP_UPD_PO_STATS() macro is updated accordingly. All
snmp_mib_*() users which used to cast the argument to (void **) are
updated to cast it to (void __percpu **).
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Vlad Yasevich <vladislav.yasevich@hp.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
The motivation for an additional notifier in batched netdevice
notification (rt_do_flush) only needs to be called once per batch not
once per namespace.
For further batching improvements I need a guarantee that the
netdevices are unregistered in order allowing me to unregister an all
of the network devices in a network namespace at the same time with
the guarantee that the loopback device is really and truly
unregistered last.
Additionally it appears that we moved the route cache flush after
the final synchronize_net, which seems wrong and there was no
explanation. So I have restored the original location of the final
synchronize_net.
Cc: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This cleanup patch puts struct/union/enum opening braces,
in first line to ease grep games.
struct something
{
becomes :
struct something {
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Define skb_rtable(const struct sk_buff *skb) accessor to get rtable from skb
Delete skb->rtable field
Setting rtable is not allowed, just set dst instead as rtable is an alias.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Set FLOWI_FLAG_ANYSRC in flowi->flags if the socket has the
transparent socket option set. This way we selectively enable certain
connections with non-local source addresses to be routed.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
inet_iif() in inet_sock.h requires route.h. Since users of inet_iif()
usually require other route.h functionality anyway this patch moves
inet_iif() to route.h.
Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Piss-poor sysctl registration API strikes again, film at 11...
What we really need is _pathname_ required to be present in already
registered table, so that kernel could warn about bad order. That's the
next target for sysctl stuff (and generally saner and more explicit
order of initialization of ipv[46] internals wouldn't hurt either).
For the time being, here are full fixups required by ..._rotable()
stuff; we make per-net sysctl sets descendents of "ro" one and make sure
that sufficient skeleton is there before we start registering per-net
sysctls.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add struct net_device parameter to ip_rt_frag_needed() and update MTU to
cache entries where ifindex is specified. This is similar to what is
already done in ip_rt_redirect().
Signed-off-by: Timo Teras <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce per-sock inlines: sock_net(), sock_net_set()
and per-inet_timewait_sock inlines: twsk_net(), twsk_net_set().
Without CONFIG_NET_NS, no namespace other than &init_net exists.
Let's explicitly define them to help compiler optimizations.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Current ip route cache implementation is not suited to large caches.
We can consume a lot of CPU when cache must be invalidated, since we
currently need to evict all cache entries, and this eviction is
sometimes asynchronous. min_delay & max_delay can somewhat control this
asynchronism behavior, but whole thing is a kludge, regularly triggering
infamous soft lockup messages. When entries are still in use, this also
consumes a lot of ram, filling dst_garbage.list.
A better scheme is to use a generation identifier on each entry,
so that cache invalidation can be performed by changing the table
identifier, without having to scan all entries.
No more delayed flushing, no more stalling when secret_interval expires.
Invalidated entries will then be freed at GC time (controled by
ip_rt_gc_timeout or stress), or when an invalidated entry is found
in a chain when an insert is done.
Thus we keep a normal equilibrium.
This patch :
- renames rt_hash_rnd to rt_genid (and makes it an atomic_t)
- Adds a new rt_genid field to 'struct rtable' (filling a hole on 64bit)
- Checks entry->rt_genid at appropriate places :
A userspace program may wish to set the mark for each packets its send
without using the netfilter MARK target. Changing the mark can be used
for mark based routing without netfilter or for packet filtering.
It requires CAP_NET_ADMIN capability.
Signed-off-by: Laszlo Attila Toth <panther@balabit.hu>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
