Stephen Hemminger a écrit :
> On Thu, 12 Nov 2009 15:11:36 +0100
> Eric Dumazet <eric.dumazet@gmail.com> wrote:
>
>> When handling large number of netdevices, inet_dump_ifaddr()
>> is very slow because it has O(N^2) complexity.
>>
>> Instead of scanning one single list, we can use the NETDEV_HASHENTRIES
>> sub lists of the dev_index hash table, and RCU lookups.
>>
>> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
>
> You might be able to make RCU critical section smaller by moving
> it into loop.
>
Indeed. But we dump at most one skb (<= 8192 bytes ?), so rcu_read_lock
holding time is small, unless we meet many netdevices without
addresses. I wonder if its really common...
Thanks
[PATCH net-next-2.6] ipv4: speedup inet_dump_ifaddr()
When handling large number of netdevices, inet_dump_ifaddr()
is very slow because it has O(N2) complexity.
Instead of scanning one single list, we can use the NETDEV_HASHENTRIES
sub lists of the dev_index hash table, and RCU lookups.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need to use next_det_device_rcu() in RCU protected section.
We also can avoid in_dev_get()/in_dev_put() overhead (code size mainly)
in rcu_read_lock() sections.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Define two symbols needed in both kernel and user space.
Remove old (somewhat incorrect) kernel variant that wasn't used in
most cases. Default should apply to both RMSS and SMSS (RFC2581).
Replace numeric constants with defined symbols.
Stand-alone patch, originally developed for TCPCT.
Signed-off-by: William.Allen.Simpson@gmail.com
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This also needs to be optimized for large number of devices.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
UDP bind() can be O(N^2) in some pathological cases.
Thanks to secondary hash tables, we can make it O(N)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When skb_clone() fails, we should increment sk_drops and SNMP counters.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
UDP multicast rx path is a bit complex and can hold a spinlock
for a long time.
Using a small (32 or 64 entries) stack of socket pointers can help
to perform expensive operations (skb_clone(), udp_queue_rcv_skb())
outside of the lock, in most cases.
It's also a base for a future RCU conversion of multicast recption.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Lucian Adrian Grijincu <lgrijincu@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We first locate the (local port) hash chain head
If few sockets are in this chain, we proceed with previous lookup algo.
If too many sockets are listed, we take a look at the secondary
(port, address) hash chain we added in previous patch.
We choose the shortest chain and proceed with a RCU lookup on the elected chain.
But, if we chose (port, address) chain, and fail to find a socket on given address,
we must try another lookup on (port, INADDR_ANY) chain to find socket not bound
to a particular IP.
-> No extra cost for typical setups, where the first lookup will probabbly
be performed.
RCU lookups everywhere, we dont acquire spinlock.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Extends udp_table to contain a secondary hash table.
socket anchor for this second hash is free, because UDP
doesnt use skc_bind_node : We define an union to hold
both skc_bind_node & a new hlist_nulls_node udp_portaddr_node
udp_lib_get_port() inserts sockets into second hash chain
(additional cost of one atomic op)
udp_lib_unhash() deletes socket from second hash chain
(additional cost of one atomic op)
Note : No spinlock lockdep annotation is needed, because
lock for the secondary hash chain is always get after
lock for primary hash chain.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Union sk_hash with two u16 hashes for udp (no extra memory taken)
One 16 bits hash on (local port) value (the previous udp 'hash')
One 16 bits hash on (local address, local port) values, initialized
but not yet used. This second hash is using jenkin hash for better
distribution.
Because the 'port' is xored later, a partial hash is performed
on local address + net_hash_mix(net)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adds a counter in udp_hslot to keep an accurate count
of sockets present in chain.
This will permit to upcoming UDP lookup algo to chose
the shortest chain when secondary hash is added.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no good reason to not support userspace specifying the
network namespace during device creation, and it makes it easier
to create a network device and pass it to a child network namespace
with a well known name.
We have to be careful to ensure that the target network namespace
for the new device exists through the life of the call. To keep
that logic clear I have factored out the network namespace grabbing
logic into rtnl_link_get_net.
In addtion we need to continue to pass the source network namespace
to the rtnl_link_ops.newlink method so that we can find the base
device source network namespace.
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
RFC 2003 requires the outer header to have DF set if DF is set
on the inner header, even when PMTU discovery is off for the
tunnel. Our implementation does exactly that.
For this to work properly the IPIP gateway also needs to engate
in PMTU when the inner DF bit is set. As otherwise the original
host would not be able to carry out its PMTU successfully since
part of the path is only visible to the gateway.
Unfortunately when the tunnel PMTU discovery setting is off, we
do not collect the necessary soft state, resulting in blackholes
when the original host tries to perform PMTU discovery.
This problem is not reproducible on the IPIP gateway itself as
the inner packet usually has skb->local_df set. This is not
correctly cleared (an unrelated bug) when the packet passes
through the tunnel, which allows fragmentation to occur. For
hosts behind the IPIP gateway it is readily visible with a simple
ping.
This patch fixes the problem by performing PMTU discovery for
all packets with the inner DF bit set, regardless of the PMTU
discovery setting on the tunnel itself.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/usb/cdc_ether.c
All CDC ethernet devices of type USB_CLASS_COMM need to use
'&mbm_info'.
Signed-off-by: David S. Miller <davem@davemloft.net>
Vitezslav Samel discovered that since 2.6.30.4+ active FTP can not work
over NAT. The "cause" of the problem was a fix of unacknowledged data
detection with NAT (commit a3a9f79e36).
However, actually, that fix uncovered a long standing bug in TCP conntrack:
when NAT was enabled, we simply updated the max of the right edge of
the segments we have seen (td_end), by the offset NAT produced with
changing IP/port in the data. However, we did not update the other parameter
(td_maxend) which is affected by the NAT offset. Thus that could drift
away from the correct value and thus resulted breaking active FTP.
The patch below fixes the issue by *not* updating the conntrack parameters
from NAT, but instead taking into account the NAT offsets in conntrack in a
consistent way. (Updating from NAT would be more harder and expensive because
it'd need to re-calculate parameters we already calculated in conntrack.)
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
When sending fragmentation expiration ICMP V4/V6 messages,
we can avoid touching device refcount, thanks to RCU
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Before calling capable(CAP_NET_RAW) check if this operations is on behalf
of the kernel or on behalf of userspace. Do not do the security check if
it is on behalf of the kernel.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The generic __sock_create function has a kern argument which allows the
security system to make decisions based on if a socket is being created by
the kernel or by userspace. This patch passes that flag to the
net_proto_family specific create function, so it can do the same thing.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct can_proto had a capability field which wasn't ever used. It is
dropped entirely.
struct inet_protosw had a capability field which can be more clearly
expressed in the code by just checking if sock->type = SOCK_RAW.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Trying to parse the option of a SYN packet that we have
no route entry for should just use global wide defaults
for route entry options.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Tested-by: Valdis.Kletnieks@vt.edu
Signed-off-by: David S. Miller <davem@davemloft.net>
Calling IPv4 specific inet_csk_route_req in tcp_check_req
is a bad idea and crashes machine on IPv6 connections, as reported
by Valdis Kletnieks
Also, all we are really interested in is the timestamp
option in the header, so calling tcp_parse_options()
with the "estab" set to false flag is an overkill as
it tries to parse half a dozen other TCP options.
We know whether timestamp should be enabled or not
using data from request_sock.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Tested-by: Valdis.Kletnieks@vt.edu
Signed-off-by: David S. Miller <davem@davemloft.net>
As pointed by Stephen Rothwell, commit c6d14c84 added a warning :
net/ipv4/devinet.c: In function 'inet_select_addr':
net/ipv4/devinet.c:902: warning: label 'out' defined but not used
delete unused 'out' label and do some cleanups as well
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adds RCU management to the list of netdevices.
Convert some for_each_netdev() users to RCU version, if
it can avoid read_lock-ing dev_base_lock
Ie:
read_lock(&dev_base_loack);
for_each_netdev(net, dev)
some_action();
read_unlock(&dev_base_lock);
becomes :
rcu_read_lock();
for_each_netdev_rcu(net, dev)
some_action();
rcu_read_unlock();
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can avoid touching device refcount in icmp_send(),
using dev_get_by_index_rcu()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use dev_get_by_index_rcu() instead of __dev_get_by_index() and
dev_base_lock rwlock
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Nathan Neulinger noticed that gretap devices get their MAC address
from the local IP address, which results in invalid MAC addresses
half of the time.
This is because gretap is still using the tunnel netdev ops rather
than the correct tap netdev ops struct.
This patch also fixes changelink to not clobber the MAC address
for the gretap case.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Tested-by: Nathan Neulinger <nneul@mst.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
On UDP sockets, we must call skb_free_datagram() with socket locked,
or risk sk_forward_alloc corruption. This requirement is not respected
in SUNRPC.
Add a convenient helper, skb_free_datagram_locked() and use it in SUNRPC
Reported-by: Francis Moreau <francis.moro@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Policy routing is not looked up by mark on reverse path filtering.
This fixes it.
Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
proto_ops->getname implies copying protocol specific data
into storage unit (particulary to __kernel_sockaddr_storage).
So when we implement new protocol support we should keep such
a detail in mind (which is easy to forget about).
Lets introduce DECLARE_SOCKADDR helper which check if
storage unit is not overfowed at build time.
Eventually inet_getname is switched to use DECLARE_SOCKADDR
(to show example of usage).
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
optlen is unsigned so the `< 0' test is never true.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add and use no DSCAK bit in the features field.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add and use no window scale bit in the features field.
Note that this is not the same as setting a window scale of 0
as would happen with window limit on route.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement querying and acting upon the no timestamp bit in the feature
field.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement querying and acting upon the no sack bit in the features
field.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need tcp_parse_options to be aware of dst_entry to
take into account per dst_entry TCP options settings
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Sigend-off-by: Ori Finkelman <ori@comsleep.com>
Sigend-off-by: Yony Amit <yony@comsleep.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since we only use tcp_parse_options here to check for the exietence
of TCP timestamp option in the header, it is better to call with
the "established" flag on.
Signed-off-by: Gilad Ben-Yossef <gilad@codefidence.com>
Signed-off-by: Ori Finkelman <ori@comsleep.com>
Signed-off-by: Yony Amit <yony@comsleep.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Speedup module unloading by factorizing synchronize_rcu() calls
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Augment raw_send_hdrinc to correct for incorrect ip header length values
A series of oopses was reported to me recently. Apparently when using AF_RAW
sockets to send data to peers that were reachable via ipsec encapsulation,
people could panic or BUG halt their systems.
I've tracked the problem down to user space sending an invalid ip header over an
AF_RAW socket with IP_HDRINCL set to 1.
Basically what happens is that userspace sends down an ip frame that includes
only the header (no data), but sets the ip header ihl value to a large number,
one that is larger than the total amount of data passed to the sendmsg call. In
raw_send_hdrincl, we allocate an skb based on the size of the data in the msghdr
that was passed in, but assume the data is all valid. Later during ipsec
encapsulation, xfrm4_tranport_output moves the entire frame back in the skbuff
to provide headroom for the ipsec headers. During this operation, the
skb->transport_header is repointed to a spot computed by
skb->network_header + the ip header length (ihl). Since so little data was
passed in relative to the value of ihl provided by the raw socket, we point
transport header to an unknown location, resulting in various crashes.
This fix for this is pretty straightforward, simply validate the value of of
iph->ihl when sending over a raw socket. If (iph->ihl*4U) > user data buffer
size, drop the frame and return -EINVAL. I just confirmed this fixes the
reported crashes.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Corrected a spelling error in a function name.
Signed-off-by: Andreas Petlund <apetlund@simula.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Speedup module unloading by factorizing synchronize_rcu() calls
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Speedup module unloading by factorizing synchronize_rcu() calls
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
GRE tunnels use one rwlock to protect their hash tables.
This locking scheme can be converted to RCU for free, since netdevice
already must wait for a RCU grace period at dismantle time.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPIP tunnels use one rwlock to protect their hash tables.
This locking scheme can be converted to RCU for free, since netdevice
already must wait for a RCU grace period at dismantle time.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit b6b39e8f3f (tcp: Try to catch MSG_PEEK bug) added a printk()
to the WARN_ON() that's in tcp.c. This patch changes this combination
to WARN(); the advantage of WARN() is that the printk message shows up
inside the message, so that kerneloops.org will collect the message.
In addition, this gets rid of an extra if() statement.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dst_negative_advice() should check for changed dst and reset
sk_tx_queue_mapping accordingly. Pass sock to the callers of
dst_negative_advice.
(sk_reset_txq is defined just for use by dst_negative_advice. The
only way I could find to get around this is to move dst_negative_()
from dst.h to dst.c, include sock.h in dst.c, etc)
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch tries to print out more information when we hit the
MSG_PEEK bug in tcp_recvmsg. It's been around since at least
2005 and it's about time that we finally fix it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use symbols instead of magic constants while checking PMTU discovery
setsockopt.
Remove redundant test in ip_rt_frag_needed() (done by caller).
Signed-off-by: John Dykstra <john.dykstra1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
