Eric W. Biederman reported a lockdep splat in inet_twsk_deschedule()
This is caused by inet_twsk_purge(), run from process context,
and commit 575f4cd5a5 (net: Use rcu lookups in inet_twsk_purge.)
removed the BH disabling that was necessary.
Add the BH disabling but fine grained, right before calling
inet_twsk_deschedule(), instead of whole function.
With help from Linus Torvalds and Eric W. Biederman
Reported-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Daniel Lezcano <daniel.lezcano@free.fr>
CC: Pavel Emelyanov <xemul@openvz.org>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
CC: stable <stable@kernel.org> (# 2.6.33+)
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>
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>
GCC emits all kinds of crazy zero extensions when we go from signed
int, to unsigned short, etc. etc.
This transformation has to be legal because:
1) In tkey_extract_bits() in mask_pfx(), the values are used to
perform shifts, on which negative values are undefined by C.
2) In fib_table_lookup() we perform comparisons with unsigned
values, constants, and additions. None of which should
encounter negative values.
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>
NETDEV_NOTIFY_PEER is an explicit request by the driver to send a link
notification while NETDEV_UP/NETDEV_CHANGEADDR generate link
notifications as a sort of side effect.
In the later cases the sysctl option is present because link
notification events can have undesired effects e.g. if the link is
flapping. I don't think this applies in the case of an explicit
request from a driver.
This patch makes NETDEV_NOTIFY_PEER unconditional, if preferred we
could add a new sysctl for this case which defaults to on.
This change causes Xen post-migration ARP notifications (which cause
switches to relearn their MAC tables etc) to be sent by default.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 0c838ff1ad (ipv4: Consolidate all default route selection
implementations.) forgot to remove one rcu_read_unlock() from
fib_select_default().
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 5811662b15 ("net: use the macros
defined for the members of flowi") accidentally removed the setting of
IPPROTO_GRE from the struct flowi in ipgre_tunnel_xmit. This patch
restores it.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
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>
Validity of the cached PMTU information is indicated by it's
expiration value being non-zero, just as per dst->expires.
The scheme we will use is that we will remember the pre-ICMP value
held in the metrics or route entry, and then at expiration time
we will restore that value.
In this way PMTU expiration does not kill off the cached route as is
done currently.
Redirect information is permanent, or at least until another redirect
is received.
Signed-off-by: David S. Miller <davem@davemloft.net>
Future changes will add caching information, and some of
these new elements will be addresses.
Since the family is implicit via the ->daddr.family member,
replicating the family in ever address we store is entirely
redundant.
Signed-off-by: David S. Miller <davem@davemloft.net>
The Linux IPv4 AH stack aligns the AH header on a 64 bit boundary
(like in IPv6). This is not RFC compliant (see RFC4302, Section
3.3.3.2.1), it should be aligned on 32 bits.
For most of the authentication algorithms, the ICV size is 96 bits.
The AH header alignment on 32 or 64 bits gives the same results.
However for SHA-256-128 for instance, the wrong 64 bit alignment results
in adding useless padding in IPv4 AH, which is forbidden by the RFC.
To avoid breaking backward compatibility, we use a new flag
(XFRM_STATE_ALIGN4) do change original behavior.
Initial patch from Dang Hongwu <hongwu.dang@6wind.com> and
Christophe Gouault <christophe.gouault@6wind.com>.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
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>
Commit 709b46e8d9 ("net: Add compat
ioctl support for the ipv4 multicast ioctl SIOCGETSGCNT") added the
correct plumbing to handle SIOCGETSGCNT properly.
However, whilst definiting a proper "struct compat_sioc_sg_req" it
isn't actually used in ipmr_compat_ioctl().
Correct this oversight.
Signed-off-by: David S. Miller <davem@davemloft.net>
If we end up including include/linux/node.h (either explicitly
or implicitly) that header has a definition of "structt node"
too.
So rename the one we use in fib_trie to "rt_trie_node" to avoid
the conflict.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
To avoid confusion with the recently deleted fib_hash.c
code, use "fib_info_hash_*" instead of plain "fib_hash_*".
Signed-off-by: David S. Miller <davem@davemloft.net>
The time has finally come to remove the hash based routing table
implementation in ipv4.
FIB Trie is mature, well tested, and I've done an audit of it's code
to confirm that it implements insert, delete, and lookup with the same
identical semantics as fib_hash did.
If there are any semantic differences found in fib_trie, we should
simply fix them.
I've placed the trie statistic config option under advanced router
configuration.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
In 135367b "netfilter: xtables: change xt_target.checkentry return type",
the type returned by checkentry was changed from boolean to int, but the
return values where not adjusted.
arptables: Input/output error
This broke arptables with the mangle target since it returns true
under success, which is interpreted by xtables as >0, thus
returning EIO.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.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>
This will be used later to implement fib_select_default() in a
completely generic manner, instead of the current situation where the
default route is re-looked up in the TRIE/HASH table and then the
available aliases are analyzed.
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>
SIOCGETSGCNT is not a unique ioctl value as it it maps tio SIOCPROTOPRIVATE +1,
which unfortunately means the existing infrastructure for compat networking
ioctls is insufficient. A trivial compact ioctl implementation would conflict
with:
SIOCAX25ADDUID
SIOCAIPXPRISLT
SIOCGETSGCNT_IN6
SIOCGETSGCNT
SIOCRSSCAUSE
SIOCX25SSUBSCRIP
SIOCX25SDTEFACILITIES
To make this work I have updated the compat_ioctl decode path to mirror the
the normal ioctl decode path. I have added an ipv4 inet_compat_ioctl function
so that I can have ipv4 specific compat ioctls. I have added a compat_ioctl
function into struct proto so I can break out ioctls by which kind of ip socket
I am using. I have added a compat_raw_ioctl function because SIOCGETSGCNT only
works on raw sockets. I have added a ipmr_compat_ioctl that mirrors the normal
ipmr_ioctl.
This was necessary because unfortunately the struct layout for the SIOCGETSGCNT
has unsigned longs in it so changes between 32bit and 64bit kernels.
This change was sufficient to run a 32bit ip multicast routing daemon on a
64bit kernel.
Reported-by: Bill Fenner <fenner@aristanetworks.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.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>
If there are no explicit metrics attached to a route, hook
fi->fib_info up to dst_default_metrics.
Signed-off-by: David S. Miller <davem@davemloft.net>
This is the initial gateway towards super-sharing metrics
if they are all set to zero for a route.
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>
Set the RTAX_LOCKED metric to INETPEER_METRICS_NEW (basically,
all ones) on fresh inetpeer entries.
This way code can determine if default metrics have been loaded
in from a routing table entry already.
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>
This patch fixes a bug that causes TCP RST packets to be generated
on otherwise correctly behaved applications, e.g., no unread data
on close,..., etc. To trigger the bug, at least two conditions must
be met:
1. The FIN flag is set on the last data packet, i.e., it's not on a
separate, FIN only packet.
2. The size of the last data chunk on the receive side matches
exactly with the size of buffer posted by the receiver, and the
receiver closes the socket without any further read attempt.
This bug was first noticed on our netperf based testbed for our IW10
proposal to IETF where a large number of RST packets were observed.
netperf's read side code meets the condition 2 above 100%.
Before the fix, tcp_data_queue() will queue the last skb that meets
condition 1 to sk_receive_queue even though it has fully copied out
(skb_copy_datagram_iovec()) the data. Then if condition 2 is also met,
tcp_recvmsg() often returns all the copied out data successfully
without actually consuming the skb, due to a check
"if ((chunk = len - tp->ucopy.len) != 0) {"
and
"len -= chunk;"
after tcp_prequeue_process() that causes "len" to become 0 and an
early exit from the big while loop.
I don't see any reason not to free the skb whose data have been fully
consumed in tcp_data_queue(), regardless of the FIN flag. We won't
get there if MSG_PEEK is on. Am I missing some arcane cases related
to urgent data?
Signed-off-by: H.K. Jerry Chu <hkchu@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Quoting Ben Hutchings: we presumably won't be defining features that
can only be enabled on 64-bit architectures.
Occurences found by `grep -r` on net/, drivers/net, include/
[ Move features and vlan_features next to each other in
struct netdev, as per Eric Dumazet's suggestion -DaveM ]
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit a8b690f98b (tcp: Fix slowness in read /proc/net/tcp)
introduced a bug in handling of SYN_RECV sockets.
st->offset represents number of sockets found since beginning of
listening_hash[st->bucket].
We should not reset st->offset when iterating through
syn_table[st->sbucket], or else if more than ~25 sockets (if
PAGE_SIZE=4096) are in SYN_RECV state, we exit from listening_get_next()
with a too small st->offset
Next time we enter tcp_seek_last_pos(), we are not able to seek past
already found sockets.
Reported-by: PK <runningdoglackey@yahoo.com>
CC: Tom Herbert <therbert@google.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Family was hard-coded to AF_INET but should be daddr->family.
This fixes crashes when unlinking ipv6 peer entries, since the
unlink code was looking up the base pointer properly.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
