This patch adds code to prevent us from attempting to allocate a tnode with
a size larger than what can be represented by size_t.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change updates the fib_table_lookup function so that it is in sync
with the fib_find_node function in terms of the explanation for the index
check based on the bits value.
I have also updated it from doing a mask to just doing a compare as I have
found that seems to provide more options to the compiler as I have seen it
turn this into a shift of the value and test under some circumstances.
In addition I addressed one minor issue in which we kept computing the key
^ n->key when checking the fib aliases. I pulled the xor out of the loop
in order to reduce the number of memory reads in the lookup. As a result
we should save a couple cycles since the xor is only done once much earlier
in the lookup.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The fib_table was wrapped in several places with an
rcu_read_lock/rcu_read_unlock however after looking over the code I found
several spots where the tables were being accessed as just standard
pointers without any protections. This change fixes that so that all of
the proper protections are in place when accessing the table to take RCU
replacement or removal of the table into account.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we are going to compact the leaf and tnode we first need to make sure
the fields are all in the same place. In that regard I am moving the leaf
pointer which represents the fib_alias hash list to occupy what is
currently the first key_vector pointer.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change makes it so that the insert and delete functions make use of
the tnode pointer returned in the fib_find_node call. By doing this we
will not have to rely on the parent pointer in the leaf which will be going
away soon.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change makes it so that the parent pointer is returned by reference in
fib_find_node. By doing this I can use it to find the parent node when I
am performing an insertion and I don't have to look for it again in
fib_insert_node.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change makes it so that leaf_walk_rcu takes a tnode and a key instead
of the trie and a leaf.
The main idea behind this is to avoid using the leaf parent pointer as that
can have additional overhead in the future as I am trying to reduce the
size of a leaf down to 16 bytes on 64b systems and 12b on 32b systems.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change makes it so that we only call resize on the tnodes, instead of
from each of the leaves. By doing this we can significantly reduce the
amount of time spent resizing as we can update all of the leaves in the
tnode first before we make any determinations about resizing. As a result
we can simply free the tnode in the case that all of the leaves from a
given tnode are flushed instead of resizing with each leaf removed.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While looking at the mpls code I found myself writing yet another
version of neigh_lookup_noref. We currently have __ipv4_lookup_noref
and __ipv6_lookup_noref.
So to make my work a little easier and to make it a smidge easier to
verify/maintain the mpls code in the future I stopped and wrote
___neigh_lookup_noref. Then I rewote __ipv4_lookup_noref and
__ipv6_lookup_noref in terms of this new function. I tested my new
version by verifying that the same code is generated in
ip_finish_output2 and ip6_finish_output2 where these functions are
inlined.
To get to ___neigh_lookup_noref I added a new neighbour cache table
function key_eq. So that the static size of the key would be
available.
I also added __neigh_lookup_noref for people who want to to lookup
a neighbour table entry quickly but don't know which neibhgour table
they are going to look up.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/rocker/rocker.c
The rocker commit was two overlapping changes, one to rename
the ->vport member to ->pport, and another making the bitmask
expression use '1ULL' instead of plain '1'.
Signed-off-by: David S. Miller <davem@davemloft.net>
If an over-MTU UDP datagram is sent through a SOCK_RAW socket to a
UFO-capable device, ip_ufo_append_data() sets skb->ip_summed to
CHECKSUM_PARTIAL unconditionally as all GSO code assumes transport layer
checksum is to be computed on segmentation. However, in this case,
skb->csum_start and skb->csum_offset are never set as raw socket
transmit path bypasses udp_send_skb() where they are usually set. As a
result, driver may access invalid memory when trying to calculate the
checksum and store the result (as observed in virtio_net driver).
Moreover, the very idea of modifying the userspace provided UDP header
is IMHO against raw socket semantics (I wasn't able to find a document
clearly stating this or the opposite, though). And while allowing
CHECKSUM_NONE in the UFO case would be more efficient, it would be a bit
too intrusive change just to handle a corner case like this. Therefore
disallowing UFO for packets from SOCK_DGRAM seems to be the best option.
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
- Add protocol to neigh_tbl so that dst->ops->protocol is not needed
- Acquire the device from neigh->dev
This results in a neigh_hh_init that will cache the samve values
regardless of the packets flowing through it.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are no more callers so kill this function.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The special case has been pushed out into ax25_neigh_construct so there
is no need to keep this code in arp.c
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After TIPC doesn't depend on iocb argument in its internal
implementations of sendmsg() and recvmsg() hooks defined in proto
structure, no any user is using iocb argument in them at all now.
Then we can drop the redundant iocb argument completely from kinds of
implementations of both sendmsg() and recvmsg() in the entire
networking stack.
Cc: Christoph Hellwig <hch@lst.de>
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As part of an effort to move skb->dropcount to skb->cb[] use a common
macro in protocol families using skb->cb[] for ancillary data to
validate available room in skb->cb[].
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp_fastopen_create_child() is static and should not be exported.
tcp4_gso_segment() and tcp6_gso_segment() should be static.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Another TCP issue is triggered by ECN.
Under pressure, receiver gets ECN marks, and send back ACK packets
with ECE TCP flag. Senders enter CA_CWR state.
In this state, tcp_tso_should_defer() is short cut :
if (icsk->icsk_ca_state != TCP_CA_Open)
goto send_now;
This means that about all ACK packets we receive are triggering
a partial send, and because cwnd is kept small, we can only send
a small amount of data for each incoming ACK,
which in return generate more ACK packets.
Allowing CA_Open and CA_CWR states to enable TSO defer in
tcp_tso_should_defer() brings performance back :
TSO autodefer has more chance to defer under pressure.
This patch increases TSO and LRO/GRO efficiency back to normal levels,
and does not impact overall ECN behavior.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With sysctl_tcp_min_tso_segs being 4, it is very possible
that tcp_tso_should_defer() decides not sending last 2 MSS
of initial window of 10 packets. This also applies if
autosizing decides to send X MSS per GSO packet, and cwnd
is not a multiple of X.
This patch implements an heuristic based on age of first
skb in write queue : If it was sent very recently (less than half srtt),
we can predict that no ACK packet will come in less than half rtt,
so deferring might cause an under utilization of our window.
This is visible on initial send (IW10) on web servers,
but more generally on some RPC, as the last part of the message
might need an extra RTT to get delivered.
Tested:
Ran following packetdrill test
// A simple server-side test that sends exactly an initial window (IW10)
// worth of packets.
`sysctl -e -q net.ipv4.tcp_min_tso_segs=4`
0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+0 bind(3, ..., ...) = 0
+0 listen(3, 1) = 0
+.1 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7>
+0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 6>
+.1 < . 1:1(0) ack 1 win 257
+0 accept(3, ..., ...) = 4
+0 write(4, ..., 14600) = 14600
+0 > . 1:5841(5840) ack 1 win 457
+0 > . 5841:11681(5840) ack 1 win 457
// Following packet should be sent right now.
+0 > P. 11681:14601(2920) ack 1 win 457
+.1 < . 1:1(0) ack 14601 win 257
+0 close(4) = 0
+0 > F. 14601:14601(0) ack 1
+.1 < F. 1:1(0) ack 14602 win 257
+0 > . 14602:14602(0) ack 2
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TSO relies on ability to defer sending a small amount of packets.
Heuristic is to wait for future ACKS in hope to send more packets at once.
Current algorithm uses a per socket tso_deferred field as a pseudo timer.
This pseudo timer relies on future ACK, but there is no guarantee
we receive them in time.
Fix would be to use a real timer, but cost of such timer is probably too
expensive for typical cases.
This patch changes the logic to test the time of last transmit,
because we should not add bursts of more than 1ms for any given flow.
We've used this patch for about two years at Google, before FQ/pacing
as it would reduce a fair amount of bursts.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
At this point the leaf_info hash is redundant. By adding the suffix length
to the fib_alias hash list we no longer have need of leaf_info as we can
determine the prefix length from fa_slen. So we can compress things by
dropping the leaf_info structure from fib_trie and instead directly connect
the leaves to the fib_alias hash list.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make use of an empty spot in the alias to store the suffix length so that
we don't need to pull that information from the leaf_info structure.
This patch also makes a slight change to the user statistics. Instead of
incrementing semantic_match_miss once per leaf_info miss we now just
increment it once per leaf if a match was not found.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This replaces the prefix length variable in the leaf_info structure with a
suffix length value, or host identifier length in bits. By doing this it
makes it easier to sort out since the tnodes and leaf are carrying this
value as well since it is compatible with the ->pos field in tnodes.
I also cleaned up one spot that had some list manipulation that could be
simplified. I basically updated it so that we just use hlist_add_head_rcu
instead of calling hlist_add_before_rcu on the first node in the list.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There isn't any advantage to having it as a list and by making it an hlist
we make the fib_alias more compatible with the list_info in terms of the
type of list used.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Joining multicast group on ethernet level via "ip maddr" command would
not work if we have an Ethernet switch that does igmp snooping since
the switch would not replicate multicast packets on ports that did not
have IGMP reports for the multicast addresses.
Linux vxlan interfaces created via "ip link add vxlan" have the group option
that enables then to do the required join.
By extending ip address command with option "autojoin" we can get similar
functionality for openvswitch vxlan interfaces as well as other tunneling
mechanisms that need to receive multicast traffic. The kernel code is
structured similar to how the vxlan driver does a group join / leave.
example:
ip address add 224.1.1.10/24 dev eth5 autojoin
ip address del 224.1.1.10/24 dev eth5
Signed-off-by: Madhu Challa <challa@noironetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the unlikely event that skb_get_hash is unable to deduce a hash
in udp_flow_src_port we use a consistent random value instead.
This is specified in GRE/UDP draft section 3.2.1:
https://tools.ietf.org/html/draft-ietf-tsvwg-gre-in-udp-encap-04
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp_should_expand_sndbuf() does not expand the send buffer if we have
filled the congestion window.
However, it should use tcp_packets_in_flight() instead of
tp->packets_out to make this check.
Testing has established that the difference matters a lot if there are
many SACKed packets, causing a needless performance shortfall.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is a need to perform igmp join/leave operations while RTNL is
held.
Make ip_mc_{join|leave}_group() wrappers around
__ip_mc_{join|leave}_group() to avoid the proliferation of work queues.
For example, vxlan_igmp_join() could possibly be removed.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skb_copy_bits() returns zero on success and negative value on error,
so it is needed to invert the condition in ip_check_defrag().
Fixes: 1bf3751ec9 ("ipv4: ip_check_defrag must not modify skb before unsharing")
Signed-off-by: Alexander Drozdov <al.drozdov@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This message isn't really needed it justs waits time/space.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking updates from David Miller:
1) Missing netlink attribute validation in nft_lookup, from Patrick
McHardy.
2) Restrict ipv6 partial checksum handling to UDP, since that's the
only case it works for. From Vlad Yasevich.
3) Clear out silly device table sentinal macros used by SSB and BCMA
drivers. From Joe Perches.
4) Make sure the remote checksum code never creates a situation where
the remote checksum is applied yet the tunneling metadata describing
the remote checksum transformation is still present. Otherwise an
external entity might see this and apply the checksum again. From
Tom Herbert.
5) Use msecs_to_jiffies() where applicable, from Nicholas Mc Guire.
6) Don't explicitly initialize timer struct fields, use setup_timer()
and mod_timer() instead. From Vaishali Thakkar.
7) Don't invoke tg3_halt() without the tp->lock held, from Jun'ichi
Nomura.
8) Missing __percpu annotation in ipvlan driver, from Eric Dumazet.
9) Don't potentially perform skb_get() on shared skbs, also from Eric
Dumazet.
10) Fix COW'ing of metrics for non-DST_HOST routes in ipv6, from Martin
KaFai Lau.
11) Fix merge resolution error between the iov_iter changes in vhost and
some bug fixes that occurred at the same time. From Jason Wang.
12) If rtnl_configure_link() fails we have to perform a call to
->dellink() before unregistering the device. From WANG Cong.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (39 commits)
net: dsa: Set valid phy interface type
rtnetlink: call ->dellink on failure when ->newlink exists
com20020-pci: add support for eae single card
vhost_net: fix wrong iter offset when setting number of buffers
net: spelling fixes
net/core: Fix warning while make xmldocs caused by dev.c
net: phy: micrel: disable NAND-tree for KSZ8021, KSZ8031, KSZ8051, KSZ8081
ipv6: fix ipv6_cow_metrics for non DST_HOST case
openvswitch: Fix key serialization.
r8152: restore hw settings
hso: fix rx parsing logic when skb allocation fails
tcp: make sure skb is not shared before using skb_get()
bridge: netfilter: Move sysctl-specific error code inside #ifdef
ipv6: fix possible deadlock in ip6_fl_purge / ip6_fl_gc
ipvlan: add a missing __percpu pcpu_stats
tg3: Hold tp->lock before calling tg3_halt() from tg3_init_one()
bgmac: fix device initialization on Northstar SoCs (condition typo)
qlcnic: Delete existing multicast MAC list before adding new
net/mlx5_core: Fix configuration of log_uar_page_sz
sunvnet: don't change gso data on clones
...
Spelling errors caught by codespell.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv6 can keep a copy of SYN message using skb_get() in
tcp_v6_conn_request() so that caller wont free the skb when calling
kfree_skb() later.
Therefore TCP fast open has to clone the skb it is queuing in
child->sk_receive_queue, as all skbs consumed from receive_queue are
freed using __kfree_skb() (ie assuming skb->users == 1)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Fixes: 5b7ed0892f ("tcp: move fastopen functions to tcp_fastopen.c")
Signed-off-by: David S. Miller <davem@davemloft.net>
Move memcg_socket_limit_enabled decrement to tcp_destroy_cgroup (called
from memcg_destroy_kmem -> mem_cgroup_sockets_destroy) and zap a bunch of
wrapper functions.
Although this patch moves static keys decrement from __mem_cgroup_free to
mem_cgroup_css_free, it does not introduce any functional changes, because
the keys are incremented on setting the limit (tcp or kmem), which can
only happen after successful mem_cgroup_css_online.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujtisu.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull security layer updates from James Morris:
"Highlights:
- Smack adds secmark support for Netfilter
- /proc/keys is now mandatory if CONFIG_KEYS=y
- TPM gets its own device class
- Added TPM 2.0 support
- Smack file hook rework (all Smack users should review this!)"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (64 commits)
cipso: don't use IPCB() to locate the CIPSO IP option
SELinux: fix error code in policydb_init()
selinux: add security in-core xattr support for pstore and debugfs
selinux: quiet the filesystem labeling behavior message
selinux: Remove unused function avc_sidcmp()
ima: /proc/keys is now mandatory
Smack: Repair netfilter dependency
X.509: silence asn1 compiler debug output
X.509: shut up about included cert for silent build
KEYS: Make /proc/keys unconditional if CONFIG_KEYS=y
MAINTAINERS: email update
tpm/tpm_tis: Add missing ifdef CONFIG_ACPI for pnp_acpi_device
smack: fix possible use after frees in task_security() callers
smack: Add missing logging in bidirectional UDS connect check
Smack: secmark support for netfilter
Smack: Rework file hooks
tpm: fix format string error in tpm-chip.c
char/tpm/tpm_crb: fix build error
smack: Fix a bidirectional UDS connect check typo
smack: introduce a special case for tmpfs in smack_d_instantiate()
...
The unified hierarchy interface for memory cgroups will no longer use "-1"
to mean maximum possible resource value. In preparation for this, make
the string an argument and let the caller supply it.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change remote checksum handling to set checksum partial as default
behavior. Added an iflink parameter to configure not using
checksum partial (calling csum_partial to update checksum).
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds infrastructure so that remote checksum offload can
set CHECKSUM_PARTIAL instead of calling csum_partial and writing
the modfied checksum field.
Add skb_remcsum_adjust_partial function to set an skb for using
CHECKSUM_PARTIAL with remote checksum offload. Changed
skb_remcsum_process and skb_gro_remcsum_process to take a boolean
argument to indicate if checksum partial can be set or the
checksum needs to be modified using the normal algorithm.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Properly set GSO types and skb->encapsulation in the UDP tunnel GRO
complete so that packets are properly represented for GSO. This sets
SKB_GSO_UDP_TUNNEL or SKB_GSO_UDP_TUNNEL_CSUM depending on whether
non-zero checksums were received, and sets SKB_GSO_TUNNEL_REMCSUM if
the remote checksum option was processed.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remote checksum offload processing is currently the same for both
the GRO and non-GRO path. When the remote checksum offload option
is encountered, the checksum field referred to is modified in
the packet. So in the GRO case, the packet is modified in the
GRO path and then the operation is skipped when the packet goes
through the normal path based on skb->remcsum_offload. There is
a problem in that the packet may be modified in the GRO path, but
then forwarded off host still containing the remote checksum option.
A remote host will again perform RCO but now the checksum verification
will fail since GRO RCO already modified the checksum.
To fix this, we ensure that GRO restores a packet to it's original
state before returning. In this model, when GRO processes a remote
checksum option it still changes the checksum per the algorithm
but on return from lower layer processing the checksum is restored
to its original value.
In this patch we add define gro_remcsum structure which is passed
to skb_gro_remcsum_process to save offset and delta for the checksum
being changed. After lower layer processing, skb_gro_remcsum_cleanup
is called to restore the checksum before returning from GRO.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Using the IPCB() macro to get the IPv4 options is convenient, but
unfortunately NetLabel often needs to examine the CIPSO option outside
of the scope of the IP layer in the stack. While historically IPCB()
worked above the IP layer, due to the inclusion of the inet_skb_param
struct at the head of the {tcp,udp}_skb_cb structs, recent commit
971f10ec ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
reordered the tcp_skb_cb struct and invalidated this IPCB() trick.
This patch fixes the problem by creating a new function,
cipso_v4_optptr(), which locates the CIPSO option inside the IP header
without calling IPCB(). Unfortunately, this isn't as fast as a simple
lookup so some additional tweaks were made to limit the use of this
new function.
Cc: <stable@vger.kernel.org> # 3.18
Reported-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Packetization Layer Path MTU Discovery works separately beside
Path MTU Discovery at IP level, different net namespace has
various requirements on which one to chose, e.g., a virutalized
container instance would require TCP PMTU to probe an usable
effective mtu for underlying tunnel, while the host would
employ classical ICMP based PMTU to function.
Hence making TCP PMTU mechanism per net namespace to decouple
two functionality. Furthermore the probe base MSS should also
be configured separately for each namespace.
Signed-off-by: Fan Du <fan.du@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a server has enabled Fast Open and it receives a pure SYN-data
packet (without a Fast Open option), it won't accept the data but it
incorrectly returns a SYN-ACK with a Fast Open cookie and also
increments the SNMP stat LINUX_MIB_TCPFASTOPENPASSIVEFAIL.
This patch makes the server include a Fast Open cookie in SYN-ACK
only if the SYN has some Fast Open option (i.e., when client
requests or presents a cookie).
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Receive Flow Steering is a nice solution but suffers from
hash collisions when a mix of connected and unconnected traffic
is received on the host, when flow hash table is populated.
Also, clearing flow in inet_release() makes RFS not very good
for short lived flows, as many packets can follow close().
(FIN , ACK packets, ...)
This patch extends the information stored into global hash table
to not only include cpu number, but upper part of the hash value.
I use a 32bit value, and dynamically split it in two parts.
For host with less than 64 possible cpus, this gives 6 bits for the
cpu number, and 26 (32-6) bits for the upper part of the hash.
Since hash bucket selection use low order bits of the hash, we have
a full hash match, if /proc/sys/net/core/rps_sock_flow_entries is big
enough.
If the hash found in flow table does not match, we fallback to RPS (if
it is enabled for the rxqueue).
This means that a packet for an non connected flow can avoid the
IPI through a unrelated/victim CPU.
This also means we no longer have to clear the table at socket
close time, and this helps short lived flows performance.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
encap.sport and encap.dport are __be16, use nla_{get,put}_be16 instead
of nla_{get,put}_u16.
Fixes the sparse warnings:
warning: incorrect type in assignment (different base types)
expected restricted __be32 [addressable] [usertype] o_key
got restricted __be16 [addressable] [usertype] i_flags
warning: incorrect type in assignment (different base types)
expected restricted __be16 [usertype] sport
got unsigned short
warning: incorrect type in assignment (different base types)
expected restricted __be16 [usertype] dport
got unsigned short
warning: incorrect type in argument 3 (different base types)
expected unsigned short [unsigned] [usertype] value
got restricted __be16 [usertype] sport
warning: incorrect type in argument 3 (different base types)
expected unsigned short [unsigned] [usertype] value
got restricted __be16 [usertype] dport
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ensure that in state FIN_WAIT2 or TIME_WAIT, where the connection is
represented by a tcp_timewait_sock, we rate limit dupacks in response
to incoming packets (a) with TCP timestamps that fail PAWS checks, or
(b) with sequence numbers that are out of the acceptable window.
We do not send a dupack in response to out-of-window packets if it has
been less than sysctl_tcp_invalid_ratelimit (default 500ms) since we
last sent a dupack in response to an out-of-window packet.
Reported-by: Avery Fay <avery@mixpanel.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ensure that in state ESTABLISHED, where the connection is represented
by a tcp_sock, we rate limit dupacks in response to incoming packets
(a) with TCP timestamps that fail PAWS checks, or (b) with sequence
numbers or ACK numbers that are out of the acceptable window.
We do not send a dupack in response to out-of-window packets if it has
been less than sysctl_tcp_invalid_ratelimit (default 500ms) since we
last sent a dupack in response to an out-of-window packet.
There is already a similar (although global) rate-limiting mechanism
for "challenge ACKs". When deciding whether to send a challence ACK,
we first consult the new per-connection rate limit, and then the
global rate limit.
Reported-by: Avery Fay <avery@mixpanel.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the SYN_RECV state, where the TCP connection is represented by
tcp_request_sock, we now rate-limit SYNACKs in response to a client's
retransmitted SYNs: we do not send a SYNACK in response to client SYN
if it has been less than sysctl_tcp_invalid_ratelimit (default 500ms)
since we last sent a SYNACK in response to a client's retransmitted
SYN.
This allows the vast majority of legitimate client connections to
proceed unimpeded, even for the most aggressive platforms, iOS and
MacOS, which actually retransmit SYNs 1-second intervals for several
times in a row. They use SYN RTO timeouts following the progression:
1,1,1,1,1,2,4,8,16,32.
Reported-by: Avery Fay <avery@mixpanel.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Helpers for mitigating ACK loops by rate-limiting dupacks sent in
response to incoming out-of-window packets.
This patch includes:
- rate-limiting logic
- sysctl to control how often we allow dupacks to out-of-window packets
- SNMP counter for cases where we rate-limited our dupack sending
The rate-limiting logic in this patch decides to not send dupacks in
response to out-of-window segments if (a) they are SYNs or pure ACKs
and (b) the remote endpoint is sending them faster than the configured
rate limit.
We rate-limit our responses rather than blocking them entirely or
resetting the connection, because legitimate connections can rely on
dupacks in response to some out-of-window segments. For example, zero
window probes are typically sent with a sequence number that is below
the current window, and ZWPs thus expect to thus elicit a dupack in
response.
We allow dupacks in response to TCP segments with data, because these
may be spurious retransmissions for which the remote endpoint wants to
receive DSACKs. This is safe because segments with data can't
realistically be part of ACK loops, which by their nature consist of
each side sending pure/data-less ACKs to each other.
The dupack interval is controlled by a new sysctl knob,
tcp_invalid_ratelimit, given in milliseconds, in case an administrator
needs to dial this upward in the face of a high-rate DoS attack. The
name and units are chosen to be analogous to the existing analogous
knob for ICMP, icmp_ratelimit.
The default value for tcp_invalid_ratelimit is 500ms, which allows at
most one such dupack per 500ms. This is chosen to be 2x faster than
the 1-second minimum RTO interval allowed by RFC 6298 (section 2, rule
2.4). We allow the extra 2x factor because network delay variations
can cause packets sent at 1 second intervals to be compressed and
arrive much closer.
Reported-by: Avery Fay <avery@mixpanel.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
