/proc/net/ipv6_route reflects the contents of fib_table_hash. The proc
handler is installed in ip6_route_net_init() whereas fib_table_hash is
allocated in fib6_net_init() _after_ the proc handler has been installed.
This opens up a short time frame to access fib_table_hash with its pants
down.
Move the registration of the proc files to a later point in the init
order to avoid the race.
Tested :-)
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
net/ipv6/route.c
Pull in 'net' again to get the revert of Thomas's change
which introduced regressions.
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit 2a0c451ade.
It causes crashes, because now ip6_null_entry is used before
it is initialized.
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
net/ipv6/route.c
This deals with a merge conflict between the net-next addition of the
inetpeer network namespace ops, and Thomas Graf's bug fix in
2a0c451ade which makes sure we don't
register /proc/net/ipv6_route before it is actually safe to do so.
Signed-off-by: David S. Miller <davem@davemloft.net>
/proc/net/ipv6_route reflects the contents of fib_table_hash. The proc
handler is installed in ip6_route_net_init() whereas fib_table_hash is
allocated in fib6_net_init() _after_ the proc handler has been installed.
This opens up a short time frame to access fib_table_hash with its pants
down.
fib6_init() as a whole can't be moved to an earlier position as it also
registers the rtnetlink message handlers which should be registered at
the end. Therefore split it into fib6_init() which is run early and
fib6_init_late() to register the rtnetlink message handlers.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Reviewed-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
One tricky issue on the ipv6 side vs. ipv4 is that the ICMP callouts
to handle the error pass the 32-bit info cookie in network byte order
whereas ipv4 passes it around in host byte order.
Like the ipv4 side, we have two helper functions. One for when we
have a socket context and one for when we do not.
ip6ip6 tunnels are not handled here, because they handle PMTU events
by essentially relaying another ICMP packet-too-big message back to
the original sender.
This patch allows us to get rid of rt6_do_pmtu_disc(). It handles all
kinds of situations that simply cannot happen when we do the PMTU
update directly using a fully resolved route.
In fact, the "plen == 128" check in ip6_rt_update_pmtu() can very
likely be removed or changed into a BUG_ON() check. We should never
have a prefixed ipv6 route when we get there.
Another piece of strange history here is that TCP and DCCP, unlike in
ipv4, never invoke the update_pmtu() method from their ICMP error
handlers. This is incredibly astonishing since this is the context
where we have the most accurate context in which to make a PMTU
update, namely we have a fully connected socket and associated cached
socket route.
Signed-off-by: David S. Miller <davem@davemloft.net>
We handle NULL in rt{,6}_set_peer but then our caller will try to pass
that NULL pointer into inet_putpeer() which isn't ready for it.
Fix this by moving the NULL check one level up, and then remove the
now unnecessary NULL check from inetpeer_ptr_set_peer().
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
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>
We only need one interface for this operation, since we always know
which inetpeer root we want to flush.
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>
add struct net as a parameter of inet_getpeer_v[4,6],
use net to replace &init_net.
and modify some places to provide net for inet_getpeer_v[4,6]
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Mostly bool conversions, some inline removals and const additions.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add #define pr_fmt(fmt) as appropriate.
Add "IPv6: " to appropriate files.
Convert printk(KERN_<LEVEL> to pr_<level> (but not KERN_DEBUG).
Standardize on "%s: " not "%s(): " when emitting __func__.
Use "%s: ", __func__ instead of embedding function name.
Coalesce formats, align arguments.
ADDRCONF output is now prefixed with "IPv6: "
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Standardize the net core ratelimited logging functions.
Coalesce formats, align arguments.
Change a printk then vprintk sequence to use printf extension %pV.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/atheros/atlx/atl1.c
drivers/net/ethernet/atheros/atlx/atl1.h
Resolved a conflict between a DMA error bug fix and NAPI
support changes in the atl1 driver.
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>
If the ipv6 dst cache which copy from the dst generated by ICMPV6 RA packet.
this dst cache will not check expire because it has no RTF_EXPIRES flag.
So this dst cache will always be used until the dst gc run.
Change the struct dst_entry,add a union contains new pointer from and expires.
When rt6_info.rt6i_flags has no RTF_EXPIRES flag,the dst.expires has no use.
we can use this field to point to where the dst cache copy from.
The dst.from is only used in IPV6.
rt6_check_expired check if rt6_info.dst.from is expired.
ip6_rt_copy only set dst.from when the ort has flag RTF_ADDRCONF
and RTF_DEFAULT.then hold the ort.
ip6_dst_destroy release the ort.
Add some functions to operate the RTF_EXPIRES flag and expires(from) together.
and change the code to use these new adding functions.
Changes from v5:
modify ip6_route_add and ndisc_router_discovery to use new adding functions.
Only set dst.from when the ort has flag RTF_ADDRCONF
and RTF_DEFAULT.then hold the ort.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In 72331bc [ipv6: Fix RTM_GETROUTE's interpretation of RTA_IIF to be
consistent with ipv4] the code of 'inet6_rtm_getroute()' was re-ordered
such that the reference to 'rt->dst' is incremented prior skb
allocation.
Hence, if 'alloc_skb()' fails, must drop a reference from 'rt->dst'.
Add the missing 'dst_release()' call.
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These macros contain a hidden goto, and are thus extremely error
prone and make code hard to audit.
Signed-off-by: David S. Miller <davem@davemloft.net>
In IPv4, if an RTA_IIF attribute is specified within an RTM_GETROUTE
message, then a route is searched as if a packet was received on the
specified 'iif' interface.
However in IPv6, RTA_IIF is not interpreted in the same way:
'inet6_rtm_getroute()' always calls 'ip6_route_output()', regardless the
RTA_IIF attribute.
As a result, in IPv6 there's no way to use RTM_GETROUTE in order to look
for a route as if a packet was received on a specific interface.
Fix 'inet6_rtm_getroute()' so that RTA_IIF is interpreted as "lookup a
route as if a packet was received on the specified interface", similar
to IPv4's 'inet_rtm_getroute()' interpretation.
Reported-by: Ami Koren <amikoren@yahoo.com>
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit f2c31e32b3 (net: fix NULL dereferences in check_peer_redir() )
added a regression in rt6_fill_node(), leading to rcu_read_lock()
imbalance.
Thats because NLA_PUT() can make a jump to nla_put_failure label.
Fix this by using nla_put()
Many thanks to Ben Greear for his help
Reported-by: Ben Greear <greearb@candelatech.com>
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 87a115783 ( ipv6: Move xfrm_lookup() call down into
icmp6_dst_alloc().) forgot to convert one error path, leading
to crashes in mld_sendpack()
Many thanks to Dave Jones for providing a very complete bug report.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.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>
release idev when ip6_neigh_lookup failed in icmp6_dst_alloc
Signed-off-by: RongQing.Li <roy.qing.li@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
During some debugging I needed to look into how /proc/net/ipv6_route
operated and in my digging I found its calling fib6_clean_all() which uses
"write_lock_bh(&table->tb6_lock)" before doing the walk of the table. I
found this on 2.6.32, but reading the code I believe the same basic idea
exists currently. Looking at the rtnetlink code they are only calling
"read_lock_bh(&table->tb6_lock);" via fib6_dump_table(). While I realize
reading from proc isn't the recommended way of fetching the ipv6 route
table; taking a write lock seems unnecessary and would probably cause
network performance issues.
To verify this I loaded up the ipv6 route table and then ran iperf in 3
cases:
* doing nothing
* reading ipv6 route table via proc
(while :; do cat /proc/net/ipv6_route > /dev/null; done)
* reading ipv6 route table via rtnetlink
(while :; do ip -6 route show table all > /dev/null; done)
* Load the ipv6 route table up with:
* for ((i = 0;i < 4000;i++)); do ip route add unreachable 2000::$i; done
* iperf commands:
* client: iperf -i 1 -V -c <ipv6 addr>
* server: iperf -V -s
* iperf results - 3 runs each (in Mbits/sec)
* nothing: client: 927,927,927 server: 927,927,927
* proc: client: 179,97,96,113 server: 142,112,133
* iproute: client: 928,927,928 server: 927,927,927
lock_stat shows taking the write lock is causing the slowdown. Using this
info I decided to write a version of fib6_clean_all() which replaces
write_lock_bh(&table->tb6_lock) with read_lock_bh(&table->tb6_lock). With
this new function I see the same results as with my rtnetlink iperf test.
Signed-off-by: Josh Hunt <joshhunt00@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In some of the rt6_bind_neighbour() call sites, it hasn't hooked
up the rt->dst.dev pointer yet, so we'd deref a NULL pointer when
obtaining dev->ifindex for the neighbour hash function computation.
Just pass the netdevice explicitly in to fix this problem.
Reported-by: Bjarke Istrup Pedersen <gurligebis@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It just obscures that the netdevice pointer and the expires value are
implemented in the dst_entry sub-object of the ipv6 route.
And it makes grepping for dst_entry member uses much harder too.
Signed-off-by: David S. Miller <davem@davemloft.net>
Also, create and use an rt6_bind_neighbour() in net/ipv6/route.c to
consolidate some common logic.
Signed-off-by: David S. Miller <davem@davemloft.net>
RDBG() wasn't even used, and the messages printed by RT6_DEBUG() were
far from useful. Just get rid of all this stuff, we can replace it
with something more suitable if we want.
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit 8e2ec63917 ("ipv6: don't
use inetpeer to store metrics for routes.") the test in rt6_alloc_cow()
for setting the ANYCAST flag is now wrong.
'rt' will always now have a plen of 128, because it is set explicitly
to 128 by ip6_rt_copy.
So to restore the semantics of the test, check the destination prefix
length of 'ort'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Don't just succeed with a route that has a NULL neighbour attached.
This follows the behavior of addrconf_dst_alloc().
Allowing this kind of route to end up with a NULL neigh attached will
result in packet drops on output until the route is somehow
invalidated, since nothing will meanwhile try to lookup the neigh
again.
A statistic is bumped for the case where we see a neigh-less route on
output, but the resulting packet drop is otherwise silent in nature,
and frankly it's a hard error for this to happen and ipv6 should do
what ipv4 does which is say something in the kernel logs.
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>
like rt6_lookup, but allows caller to pass in flowi6 structure.
Will be used by the upcoming ipv6 netfilter reverse path filter
match.
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
It's only used in net/ipv6/route.c and the NULL device check is
superfluous for all of the existing call sites.
Just expand the __ndisc_lookup_errno() call at each location.
Signed-off-by: David S. Miller <davem@davemloft.net>
1) x == NULL --> !x
2) x != NULL --> x
3) (x&BIT) --> (x & BIT)
4) (BIT1|BIT2) --> (BIT1 | BIT2)
5) proper argument and struct member alignment
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>
C assignment can handle struct in6_addr copying.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The support for NLM_F_* flags at IPv6 routing requests.
Warn if NLM_F_CREATE flag is not defined for RTM_NEWROUTE request,
creating new table. Later NLM_F_CREATE may be required for
new route creation.
Patch created against linux-3.2-rc1
Signed-off-by: Matti Vaittinen <Mazziesaccount@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
These files are non modular, but need to export symbols using
the macros now living in export.h -- call out the include so
that things won't break when we remove the implicit presence
of module.h from everywhere.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
in func icmp6_dst_alloc,dst_metric_set call ipv6_cow_metrics to set metric.
ipv6_cow_metrics may will call rt6_bind_peer to set rt6_info->rt6i_peer.
So,we should move ipv6_addr_copy before dst_metric_set to make sure rt6_bind_peer success.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
return value of dst_alloc must be checked before use
Signed-off-by: Madalin Bucur <madalin.bucur@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Current IPv6 implementation uses inetpeer to store metrics for
routes. The problem of inetpeer is that it doesn't take subnet
prefix length in to consideration. If two routes have the same
address but different prefix length, they share same inetpeer.
So changing metrics of one route also affects the other. The
fix is to allocate separate metrics storage for each route.
Signed-off-by: Zheng Yan <zheng.z.yan@intel.com>
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>
We currently cow metrics a bit too soon in IPv6 case : All routes are
tied to a single inetpeer entry.
Change ip6_rt_copy() to get destination address as second argument, so
that we fill rt6i_dst before the dst_copy_metrics() call.
icmp6_dst_alloc() must set rt6i_dst before calling dst_metric_set(), or
else the cow is done while rt6i_dst is still NULL.
If orig route points to readonly metrics, we can share the pointer
instead of performing the memory allocation and copy.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
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 just makes it harder to see 1) what the code is doing
and 2) grep for all users of dst{->,.}neighbour
Signed-off-by: David S. Miller <davem@davemloft.net>
IPV6, unlike IPV4, doesn't have a routing cache.
Routing table entries, as well as clones made in response
to route lookup requests, all live in the same table. And
all of these things are together collected in the destination
cache table for ipv6.
This means that routing table entries count against the garbage
collection limits, even though such entries cannot ever be reclaimed
and are added explicitly by the administrator (rather than being
created in response to lookups).
Therefore it makes no sense to count ipv6 routing table entries
against the GC limits.
Add a DST_NOCOUNT destination cache entry flag, and skip the counting
if it is set. Use this flag bit in ipv6 when adding routing table
entries.
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 c3968a857a
('ipv6: RTA_PREFSRC support for ipv6 route source address selection')
added support for ipv6 prefsrc as an alternative to ipv6 addrlabels,
but it did not work because the prefsrc entry was not copied.
Cc: Daniel Walter <sahne@0x90.at>
Signed-off-by: Florian Westphal <fw@strlen.de>
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>
The changes introduced with git-commit a02e4b7d ("ipv6: Demark default
hoplimit as zero.") missed to remove the hoplimit initialization. As a
result, ipv6_get_mtu interprets the return value of dst_metric_raw
(-1) as 255 and answers ping6 with this hoplimit. This patche removes
the line such that ping6 is answered with the hoplimit value
configured via sysctl.
Signed-off-by: Thomas Egerer <thomas.egerer@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[ipv6] Add support for RTA_PREFSRC
This patch allows a user to select the preferred source address
for a specific IPv6-Route. It can be set via a netlink message
setting RTA_PREFSRC to a valid IPv6 address which must be
up on the device the route will be bound to.
Signed-off-by: Daniel Walter <dwalter@barracuda.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This avoids explicit cast to avoid 'discards qualifiers'
compiler warning in a netfilter patch that i've been working on.
Signed-off-by: Florian Westphal <fw@strlen.de>
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>
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=29252
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=30462
In commit d80bc0fd26 ("ipv6: Always
clone offlink routes.") we forced the kernel to always clone offlink
routes.
The reason we do that is to make sure we never bind an inetpeer to a
prefixed route.
The logic turned on here has existed in the tree for many years,
but was always off due to a protecting CPP define. So perhaps
it's no surprise that there is a logic bug here.
The problem is that we canot clone a route that is already a
host route (ie. has DST_HOST set). Because if we do, an identical
entry already exists in the routing tree and therefore the
ip6_rt_ins() call is going to fail.
This sets off a series of failures and high cpu usage, because when
ip6_rt_ins() fails we loop retrying this operation a few times in
order to handle a race between two threads trying to clone and insert
the same host route at the same time.
Fix this by simply using the route as-is when DST_HOST is set.
Reported-by: slash@ac.auone-net.jp
Reported-by: Ernst Sjöstrand <ernstp@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Return a dst pointer which is potentitally error encoded.
Don't pass original dst pointer by reference, pass a struct net
instead of a socket, and elide the flow argument since it is
unnecessary.
Signed-off-by: David S. Miller <davem@davemloft.net>
Before this patch issuing these commands:
fd = open("/proc/sys/net/ipv6/route/flush")
unshare(CLONE_NEWNET)
write(fd, "stuff")
would flush the newly created net, not the original one.
The equivalent ipv4 code is correct (stores the net inside ->extra1).
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
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>
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>
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>
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>
They are bogus. The basic idea is that I wanted to make sure
that prefixed routes never bind to peers.
The test I used was whether RTF_CACHE was set.
But first of all, the RTF_CACHE flag is set at different spots
depending upon which ip6_rt_copy() caller you're talking about.
I've validated all of the code paths, and even in the future
where we bind peers more aggressively (for route metric COW'ing)
we never bind to prefix'd routes, only fully specified ones.
This even applies when addrconf or icmp6 routes are allocated.
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>
Do not handle PMTU vs. route lookup creation any differently
wrt. offlink routes, always clone them.
Reported-by: PK <runningdoglackey@yahoo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove (unnecessary) casts to make code cleaner.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
