[ Upstream commit 86de5921a3 ]
Jean-Louis reported a TCP regression and bisected to recent SACK
compression.
After a loss episode (receiver not able to keep up and dropping
packets because its backlog is full), linux TCP stack is sending
a single SACK (DUPACK).
Sender waits a full RTO timer before recovering losses.
While RFC 6675 says in section 5, "Algorithm Details",
(2) If DupAcks < DupThresh but IsLost (HighACK + 1) returns true --
indicating at least three segments have arrived above the current
cumulative acknowledgment point, which is taken to indicate loss
-- go to step (4).
...
(4) Invoke fast retransmit and enter loss recovery as follows:
there are old TCP stacks not implementing this strategy, and
still counting the dupacks before starting fast retransmit.
While these stacks probably perform poorly when receivers implement
LRO/GRO, we should be a little more gentle to them.
This patch makes sure we do not enable SACK compression unless
3 dupacks have been sent since last rcv_nxt update.
Ideally we should even rearm the timer to send one or two
more DUPACK if no more packets are coming, but that will
be work aiming for linux-4.21.
Many thanks to Jean-Louis for bisecting the issue, providing
packet captures and testing this patch.
Fixes: 5d9f4262b7 ("tcp: add SACK compression")
Reported-by: Jean-Louis Dupond <jean-louis@dupond.be>
Tested-by: Jean-Louis Dupond <jean-louis@dupond.be>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8873c064d1 upstream.
syzkaller was able to hit the WARN_ON(sock_owned_by_user(sk));
in tcp_close()
While a socket is being closed, it is very possible other
threads find it in rtnetlink dump.
tcp_get_info() will acquire the socket lock for a short amount
of time (slow = lock_sock_fast(sk)/unlock_sock_fast(sk, slow);),
enough to trigger the warning.
Fixes: 67db3e4bfb ("tcp: no longer hold ehash lock while calling tcp_get_info()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0d5b9311ba ]
Multiple cpus might attempt to insert a new fragment in rhashtable,
if for example RPS is buggy, as reported by 배석진 in
https://patchwork.ozlabs.org/patch/994601/
We use rhashtable_lookup_get_insert_key() instead of
rhashtable_insert_fast() to let cpus losing the race
free their own inet_frag_queue and use the one that
was inserted by another cpu.
Fixes: 648700f76b ("inet: frags: use rhashtables for reassembly units")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: 배석진 <soukjin.bae@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit cadf9df27e ]
During tcp coalescing ensure that the skb hardware timestamp refers to the
highest sequence number data.
Previously only the software timestamp was updated during coalescing.
Signed-off-by: Stephen Mallon <stephen.mallon@sydney.edu.au>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 16f7eb2b77 ]
The various types of tunnels running over IPv4 can ask to set the DF
bit to do PMTU discovery. However, PMTU discovery is subject to the
threshold set by the net.ipv4.route.min_pmtu sysctl, and is also
disabled on routes with "mtu lock". In those cases, we shouldn't set
the DF bit.
This patch makes setting the DF bit conditional on the route's MTU
locking state.
This issue seems to be older than git history.
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 076ed3da0c upstream.
commit 40413955ee ("Cipso: cipso_v4_optptr enter infinite loop") fixed
a possible infinite loop in the IP option parsing of CIPSO. The fix
assumes that ip_options_compile filtered out all zero length options and
that no other one-byte options beside IPOPT_END and IPOPT_NOOP exist.
While this assumption currently holds true, add explicit checks for zero
length and invalid length options to be safe for the future. Even though
ip_options_compile should have validated the options, the introduction of
new one-byte options can still confuse this code without the additional
checks.
Signed-off-by: Stefan Nuernberger <snu@amazon.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Simon Veith <sveith@amazon.de>
Cc: stable@vger.kernel.org
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7de414a9dd ]
Most callers of pskb_trim_rcsum() simply drop the skb when
it fails, however, ip_check_defrag() still continues to pass
the skb up to stack. This is suspicious.
In ip_check_defrag(), after we learn the skb is an IP fragment,
passing the skb to callers makes no sense, because callers expect
fragments are defrag'ed on success. So, dropping the skb when we
can't defrag it is reasonable.
Note, prior to commit 88078d98d1, this is not a big problem as
checksum will be fixed up anyway. After it, the checksum is not
correct on failure.
Found this during code review.
Fixes: 88078d98d1 ("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends")
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 89ab066d42 ]
This reverts commit dd979b4df8.
This broke tcp_poll for SMC fallback: An AF_SMC socket establishes an
internal TCP socket for the initial handshake with the remote peer.
Whenever the SMC connection can not be established this TCP socket is
used as a fallback. All socket operations on the SMC socket are then
forwarded to the TCP socket. In case of poll, the file->private_data
pointer references the SMC socket because the TCP socket has no file
assigned. This causes tcp_poll to wait on the wrong socket.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit db4f1be3ca ]
Current handling of CHECKSUM_COMPLETE packets by the UDP stack is
incorrect for any packet that has an incorrect checksum value.
udp4/6_csum_init() will both make a call to
__skb_checksum_validate_complete() to initialize/validate the csum
field when receiving a CHECKSUM_COMPLETE packet. When this packet
fails validation, skb->csum will be overwritten with the pseudoheader
checksum so the packet can be fully validated by software, but the
skb->ip_summed value will be left as CHECKSUM_COMPLETE so that way
the stack can later warn the user about their hardware spewing bad
checksums. Unfortunately, leaving the SKB in this state can cause
problems later on in the checksum calculation.
Since the the packet is still marked as CHECKSUM_COMPLETE,
udp_csum_pull_header() will SUBTRACT the checksum of the UDP header
from skb->csum instead of adding it, leaving us with a garbage value
in that field. Once we try to copy the packet to userspace in the
udp4/6_recvmsg(), we'll make a call to skb_copy_and_csum_datagram_msg()
to checksum the packet data and add it in the garbage skb->csum value
to perform our final validation check.
Since the value we're validating is not the proper checksum, it's possible
that the folded value could come out to 0, causing us not to drop the
packet. Instead, we believe that the packet was checksummed incorrectly
by hardware since skb->ip_summed is still CHECKSUM_COMPLETE, and we attempt
to warn the user with netdev_rx_csum_fault(skb->dev);
Unfortunately, since this is the UDP path, skb->dev has been overwritten
by skb->dev_scratch and is no longer a valid pointer, so we end up
reading invalid memory.
This patch addresses this problem in two ways:
1) Do not use the dev pointer when calling netdev_rx_csum_fault()
from skb_copy_and_csum_datagram_msg(). Since this gets called
from the UDP path where skb->dev has been overwritten, we have
no way of knowing if the pointer is still valid. Also for the
sake of consistency with the other uses of
netdev_rx_csum_fault(), don't attempt to call it if the
packet was checksummed by software.
2) Add better CHECKSUM_COMPLETE handling to udp4/6_csum_init().
If we receive a packet that's CHECKSUM_COMPLETE that fails
verification (i.e. skb->csum_valid == 0), check who performed
the calculation. It's possible that the checksum was done in
software by the network stack earlier (such as Netfilter's
CONNTRACK module), and if that says the checksum is bad,
we can drop the packet immediately instead of waiting until
we try and copy it to userspace. Otherwise, we need to
mark the SKB as CHECKSUM_NONE, since the skb->csum field
no longer contains the full packet checksum after the
call to __skb_checksum_validate_complete().
Fixes: e6afc8ace6 ("udp: remove headers from UDP packets before queueing")
Fixes: c84d949057 ("udp: copy skb->truesize in the first cache line")
Cc: Sam Kumar <samanthakumar@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Sean Tranchetti <stranche@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the skb space ends in an unresolved entry while dumping we'll miss
some unresolved entries. The reason is due to zeroing the entry counter
between dumping resolved and unresolved mfc entries. We should just
keep counting until the whole table is dumped and zero when we move to
the next as we have a separate table counter.
Reported-by: Colin Ian King <colin.king@canonical.com>
Fixes: 8fb472c09b ("ipmr: improve hash scalability")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When an MTU update with PMTU smaller than net.ipv4.route.min_pmtu is
received, we must clamp its value. However, we can receive a PMTU
exception with PMTU < old_mtu < ip_rt_min_pmtu, which would lead to an
increase in PMTU.
To fix this, take the smallest of the old MTU and ip_rt_min_pmtu.
Before this patch, in case of an update, the exception's MTU would
always change. Now, an exception can have only its lock flag updated,
but not the MTU, so we need to add a check on locking to the following
"is this exception getting updated, or close to expiring?" test.
Fixes: d52e5a7e7c ("ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit 5aad1de5ea ("ipv4: use separate genid for next hop
exceptions"), exceptions get deprecated separately from cached
routes. In particular, administrative changes don't clear PMTU anymore.
As Stefano described in commit e9fa1495d7 ("ipv6: Reflect MTU changes
on PMTU of exceptions for MTU-less routes"), the PMTU discovered before
the local MTU change can become stale:
- if the local MTU is now lower than the PMTU, that PMTU is now
incorrect
- if the local MTU was the lowest value in the path, and is increased,
we might discover a higher PMTU
Similarly to what commit e9fa1495d7 did for IPv6, update PMTU in those
cases.
If the exception was locked, the discovered PMTU was smaller than the
minimal accepted PMTU. In that case, if the new local MTU is smaller
than the current PMTU, let PMTU discovery figure out if locking of the
exception is still needed.
To do this, we need to know the old link MTU in the NETDEV_CHANGEMTU
notifier. By the time the notifier is called, dev->mtu has been
changed. This patch adds the old MTU as additional information in the
notifier structure, and a new call_netdevice_notifiers_u32() function.
Fixes: 5aad1de5ea ("ipv4: use separate genid for next hop exceptions")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 2276f58ac5 ("udp: use a separate rx queue for packet reception")
turned static inline __skb_recv_udp() from being a trivial helper around
__skb_recv_datagram() into a UDP specific implementaion, making it
EXPORT_SYMBOL_GPL() at the same time.
There are external modules that got broken by __skb_recv_udp() not being
visible to them. Let's unbreak them by making __skb_recv_udp EXPORT_SYMBOL().
Rationale (one of those) why this is actually "technically correct" thing
to do: __skb_recv_udp() used to be an inline wrapper around
__skb_recv_datagram(), which itself (still, and correctly so, I believe)
is EXPORT_SYMBOL().
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Fixes: 2276f58ac5 ("udp: use a separate rx queue for packet reception")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Caching ip_hdr(skb) before a call to pskb_may_pull() is buggy,
do not do it.
Fixes: 2efd4fca70 ("ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Timer handlers do not imply rcu_read_lock(), so my recent fix
triggered a LOCKDEP warning when SYNACK is retransmit.
Lets add rcu_read_lock()/rcu_read_unlock() pairs around ireq->ireq_opt
usages instead of guessing what is done by callers, since it is
not worth the pain.
Get rid of ireq_opt_deref() helper since it hides the logic
without real benefit, since it is now a standard rcu_dereference().
Fixes: 1ad98e9d1b ("tcp/dccp: fix lockdep issue when SYN is backlogged")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Steffen Klassert says:
====================
pull request (net): ipsec 2018-10-01
1) Validate address prefix lengths in the xfrm selector,
otherwise we may hit undefined behaviour in the
address matching functions if the prefix is too
big for the given address family.
2) Fix skb leak on local message size errors.
From Thadeu Lima de Souza Cascardo.
3) We currently reset the transport header back to the network
header after a transport mode transformation is applied. This
leads to an incorrect transport header when multiple transport
mode transformations are applied. Reset the transport header
only after all transformations are already applied to fix this.
From Sowmini Varadhan.
4) We only support one offloaded xfrm, so reset crypto_done after
the first transformation in xfrm_input(). Otherwise we may call
the wrong input method for subsequent transformations.
From Sowmini Varadhan.
5) Fix NULL pointer dereference when skb_dst_force clears the dst_entry.
skb_dst_force does not really force a dst refcount anymore, it might
clear it instead. xfrm code did not expect this, add a check to not
dereference skb_dst() if it was cleared by skb_dst_force.
6) Validate xfrm template mode, otherwise we can get a stack-out-of-bounds
read in xfrm_state_find. From Sean Tranchetti.
Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
In normal SYN processing, packets are handled without listener
lock and in RCU protected ingress path.
But syzkaller is known to be able to trick us and SYN
packets might be processed in process context, after being
queued into socket backlog.
In commit 06f877d613 ("tcp/dccp: fix other lockdep splats
accessing ireq_opt") I made a very stupid fix, that happened
to work mostly because of the regular path being RCU protected.
Really the thing protecting ireq->ireq_opt is RCU read lock,
and the pseudo request refcnt is not relevant.
This patch extends what I did in commit 449809a66c ("tcp/dccp:
block BH for SYN processing") by adding an extra rcu_read_{lock|unlock}
pair in the paths that might be taken when processing SYN from
socket backlog (thus possibly in process context)
Fixes: 06f877d613 ("tcp/dccp: fix other lockdep splats accessing ireq_opt")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cong noted that we need the same checks introduced by commit 76c0ddd8c3
("ip6_tunnel: be careful when accessing the inner header")
even for ipv4 tunnels.
Fixes: c544193214 ("GRE: Refactor GRE tunneling code.")
Suggested-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 2abb7cdc0d ("udp: Add support for doing checksum
unnecessary conversion") left out the early demux path for
connected sockets. As a result IP_CMSG_CHECKSUM gives wrong
values for such socket when GRO is not enabled/available.
This change addresses the issue by moving the csum conversion to a
common helper and using such helper in both the default and the
early demux rx path.
Fixes: 2abb7cdc0d ("udp: Add support for doing checksum unnecessary conversion")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When splitting a GSO segment that consists of encapsulated packets, the
skb->mac_len of the segments can end up being set wrong, causing packet
drops in particular when using act_mirred and ifb interfaces in
combination with a qdisc that splits GSO packets.
This happens because at the time skb_segment() is called, network_header
will point to the inner header, throwing off the calculation in
skb_reset_mac_len(). The network_header is subsequently adjust by the
outer IP gso_segment handlers, but they don't set the mac_len.
Fix this by adding skb_reset_mac_len() calls to both the IPv4 and IPv6
gso_segment handlers, after they modify the network_header.
Many thanks to Eric Dumazet for his help in identifying the cause of
the bug.
Acked-by: Dave Taht <dave.taht@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
When processing icmp unreachable message for erspan tunnel, tunnel id
should be erspan_net_id instead of ipgre_net_id.
Fixes: 84e54fe0a5 ("gre: introduce native tunnel support for ERSPAN")
Cc: William Tu <u9012063@gmail.com>
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Acked-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If erspan tunnel hasn't been established, we'd better send icmp port
unreachable message after receive erspan packets.
Fixes: 84e54fe0a5 ("gre: introduce native tunnel support for ERSPAN")
Cc: William Tu <u9012063@gmail.com>
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Acked-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert pr_info to net_info_ratelimited to limit the total number of
synflood warnings.
Commit 946cedccbd ("tcp: Change possible SYN flooding messages")
rate limits synflood warnings to one per listener.
Workloads that open many listener sockets can still see a high rate of
log messages. Syzkaller is one frequent example.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for you net tree:
1) Remove duplicated include at the end of UDP conntrack, from Yue Haibing.
2) Restore conntrack dependency on xt_cluster, from Martin Willi.
3) Fix splat with GSO skbs from the checksum target, from Florian Westphal.
4) Rework ct timeout support, the template strategy to attach custom timeouts
is not correct since it will not work in conjunction with conntrack zones
and we have a possible free after use when removing the rule due to missing
refcounting. To fix these problems, do not use conntrack template at all
and set custom timeout on the already valid conntrack object. This
fix comes with a preparation patch to simplify timeout adjustment by
initializating the first position of the timeout array for all of the
existing trackers. Patchset from Florian Westphal.
5) Fix missing dependency on from IPv4 chain NAT type, from Florian.
6) Release chain reference counter from the flush path, from Taehee Yoo.
7) After flushing an iptables ruleset, conntrack hooks are unregistered
and entries are left stale to be cleaned up by the timeout garbage
collector. No TCP tracking is done on established flows by this time.
If ruleset is reloaded, then hooks are registered again and TCP
tracking is restored, which considers packets to be invalid. Clear
window tracking to exercise TCP flow pickup from the middle given that
history is lost for us. Again from Florian.
8) Fix crash from netlink interface with CONFIG_NF_CONNTRACK_TIMEOUT=y
and CONFIG_NF_CT_NETLINK_TIMEOUT=n.
9) Broken CT target due to returning incorrect type from
ctnl_timeout_find_get().
10) Solve conntrack clash on NF_REPEAT verdicts too, from Michal Vaner.
11) Missing conversion of hashlimit sysctl interface to new API, from
Cong Wang.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
According to the documentation in msg_zerocopy.rst, the SO_ZEROCOPY
flag was introduced because send(2) ignores unknown message flags and
any legacy application which was accidentally passing the equivalent of
MSG_ZEROCOPY earlier should not see any new behaviour.
Before commit f214f915e7 ("tcp: enable MSG_ZEROCOPY"), a send(2) call
which passed the equivalent of MSG_ZEROCOPY without setting SO_ZEROCOPY
would succeed. However, after that commit, it fails with -ENOBUFS. So
it appears that the SO_ZEROCOPY flag fails to fulfill its intended
purpose. Fix it.
Fixes: f214f915e7 ("tcp: enable MSG_ZEROCOPY")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A policy may have been set up with multiple transforms (e.g., ESP
and ipcomp). In this situation, the ingress IPsec processing
iterates in xfrm_input() and applies each transform in turn,
processing the nexthdr to find any additional xfrm that may apply.
This patch resets the transport header back to network header
only after the last transformation so that subsequent xfrms
can find the correct transport header.
Fixes: 7785bba299 ("esp: Add a software GRO codepath")
Suggested-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
After link down and up, i.e. when call ip_mc_up(), we doesn't init
im->unsolicit_count. So after igmp_timer_expire(), we will not start
timer again and only send one unsolicit report at last.
Fix it by initializing im->unsolicit_count in igmp_group_added(), so
we can respect igmp robustness value.
Fixes: 24803f38a5 ("igmp: do not remove igmp souce list info when set link down")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We should not start timer if im->unsolicit_count equal to 0 after decrease.
Or we will send one more unsolicit report message. i.e. 3 instead of 2 by
default.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
RFC 1337 says:
''Ignore RST segments in TIME-WAIT state.
If the 2 minute MSL is enforced, this fix avoids all three hazards.''
So with net.ipv4.tcp_rfc1337=1, expected behaviour is to have TIME-WAIT sk
expire rather than removing it instantly when a reset is received.
However, Linux will also re-start the TIME-WAIT timer.
This causes connect to fail when tying to re-use ports or very long
delays (until syn retry interval exceeds MSL).
packetdrill test case:
// Demonstrate bogus rearming of TIME-WAIT timer in rfc1337 mode.
`sysctl net.ipv4.tcp_rfc1337=1`
0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
0.000 bind(3, ..., ...) = 0
0.000 listen(3, 1) = 0
0.100 < S 0:0(0) win 29200 <mss 1460,nop,nop,sackOK,nop,wscale 7>
0.100 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7>
0.200 < . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4
// Receive first segment
0.310 < P. 1:1001(1000) ack 1 win 46
// Send one ACK
0.310 > . 1:1(0) ack 1001
// read 1000 byte
0.310 read(4, ..., 1000) = 1000
// Application writes 100 bytes
0.350 write(4, ..., 100) = 100
0.350 > P. 1:101(100) ack 1001
// ACK
0.500 < . 1001:1001(0) ack 101 win 257
// close the connection
0.600 close(4) = 0
0.600 > F. 101:101(0) ack 1001 win 244
// Our side is in FIN_WAIT_1 & waits for ack to fin
0.7 < . 1001:1001(0) ack 102 win 244
// Our side is in FIN_WAIT_2 with no outstanding data.
0.8 < F. 1001:1001(0) ack 102 win 244
0.8 > . 102:102(0) ack 1002 win 244
// Our side is now in TIME_WAIT state, send ack for fin.
0.9 < F. 1002:1002(0) ack 102 win 244
0.9 > . 102:102(0) ack 1002 win 244
// Peer reopens with in-window SYN:
1.000 < S 1000:1000(0) win 9200 <mss 1460,nop,nop,sackOK,nop,wscale 7>
// Therefore, reply with ACK.
1.000 > . 102:102(0) ack 1002 win 244
// Peer sends RST for this ACK. Normally this RST results
// in tw socket removal, but rfc1337=1 setting prevents this.
1.100 < R 1002:1002(0) win 244
// second syn. Due to rfc1337=1 expect another pure ACK.
31.0 < S 1000:1000(0) win 9200 <mss 1460,nop,nop,sackOK,nop,wscale 7>
31.0 > . 102:102(0) ack 1002 win 244
// .. and another RST from peer.
31.1 < R 1002:1002(0) win 244
31.2 `echo no timer restart;ss -m -e -a -i -n -t -o state TIME-WAIT`
// third syn after one minute. Time-Wait socket should have expired by now.
63.0 < S 1000:1000(0) win 9200 <mss 1460,nop,nop,sackOK,nop,wscale 7>
// so we expect a syn-ack & 3whs to proceed from here on.
63.0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 7>
Without this patch, 'ss' shows restarts of tw timer and last packet is
thus just another pure ack, more than one minute later.
This restores the original code from commit 283fd6cf0be690a83
("Merge in ANK networking jumbo patch") in netdev-vger-cvs.git .
For some reason the else branch was removed/lost in 1f28b683339f7
("Merge in TCP/UDP optimizations and [..]") and timer restart became
unconditional.
Reported-by: Michal Tesar <mtesar@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
NF_TABLES_IPV4 is now boolean so it is possible to set
NF_TABLES=m
NF_TABLES_IPV4=y
NFT_CHAIN_NAT_IPV4=y
which causes:
nft_chain_nat_ipv4.c:(.text+0x6d): undefined reference to `nft_do_chain'
Wrap NFT_CHAIN_NAT_IPV4 and related nat expressions with NF_TABLES to
restore the dependency.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Fixes: 02c7b25e5f ("netfilter: nf_tables: build-in filter chain type")
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
After erspan_ver is introudced, if erspan_ver is not set in iproute, its
value will be left 0 by default. Since Commit 02f99df187 ("erspan: fix
invalid erspan version."), it has broken the traffic due to the version
check in erspan_xmit if users are not aware of 'erspan_ver' param, like
using an old version of iproute.
To fix this compatibility problem, it sets erspan_ver to 1 by default
when adding an erspan dev in erspan_setup. Note that we can't do it in
ipgre_netlink_parms, as this function is also used by ipgre_changelink.
Fixes: 02f99df187 ("erspan: fix invalid erspan version.")
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit fixes a corner case where TCP BBR would enter PROBE_RTT
mode but not reduce its cwnd. If a TCP receiver ACKed less than one
full segment, the number of delivered/acked packets was 0, so that
bbr_set_cwnd() would short-circuit and exit early, without cutting
cwnd to the value we want for PROBE_RTT.
The fix is to instead make sure that even when 0 full packets are
ACKed, we do apply all the appropriate caps, including the cap that
applies in PROBE_RTT mode.
Fixes: 0f8782ea14 ("tcp_bbr: add BBR congestion control")
Signed-off-by: Kevin Yang <yyd@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fix the case where BBR does not exit PROBE_RTT mode when
it restarts from idle. When BBR restarts from idle and if BBR is in
PROBE_RTT mode, BBR should check if it's time to exit PROBE_RTT. If
yes, then BBR should exit PROBE_RTT mode and restore the cwnd to its
full value.
Fixes: 0f8782ea14 ("tcp_bbr: add BBR congestion control")
Signed-off-by: Kevin Yang <yyd@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch add a helper function bbr_check_probe_rtt_done() to
1. check the condition to see if bbr should exit probe_rtt mode;
2. process the logic of exiting probe_rtt mode.
Fixes: 0f8782ea14 ("tcp_bbr: add BBR congestion control")
Signed-off-by: Kevin Yang <yyd@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp uses per-cpu (and per namespace) sockets (net->ipv4.tcp_sk) internally
to send some control packets.
1) RST packets, through tcp_v4_send_reset()
2) ACK packets in SYN-RECV and TIME-WAIT state, through tcp_v4_send_ack()
These packets assert IP_DF, and also use the hashed IP ident generator
to provide an IPv4 ID number.
Geoff Alexander reported this could be used to build off-path attacks.
These packets should not be fragmented, since their size is smaller than
IPV4_MIN_MTU. Only some tunneled paths could eventually have to fragment,
regardless of inner IPID.
We really can use zero IPID, to address the flaw, and as a bonus,
avoid a couple of atomic operations in ip_idents_reserve()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Geoff Alexander <alexandg@cs.unm.edu>
Tested-by: Geoff Alexander <alexandg@cs.unm.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
I found that in BPF sockmap programs once we either delete a socket
from the map or we updated a map slot and the old socket was purged
from the map that these socket can never get reattached into a map
even though their related psock has been dropped entirely at that
point.
Reason is that tcp_cleanup_ulp() leaves the old icsk->icsk_ulp_ops
intact, so that on the next tcp_set_ulp_id() the kernel returns an
-EEXIST thinking there is still some active ULP attached.
BPF sockmap is the only one that has this issue as the other user,
kTLS, only calls tcp_cleanup_ulp() from tcp_v4_destroy_sock() whereas
sockmap semantics allow dropping the socket from the map with all
related psock state being cleaned up.
Fixes: 1aa12bdf1b ("bpf: sockmap, add sock close() hook to remove socks")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Lets not turn the TCP ULP lookup into an arbitrary module loader as
we only intend to load ULP modules through this mechanism, not other
unrelated kernel modules:
[root@bar]# cat foo.c
#include <sys/types.h>
#include <sys/socket.h>
#include <linux/tcp.h>
#include <linux/in.h>
int main(void)
{
int sock = socket(PF_INET, SOCK_STREAM, 0);
setsockopt(sock, IPPROTO_TCP, TCP_ULP, "sctp", sizeof("sctp"));
return 0;
}
[root@bar]# gcc foo.c -O2 -Wall
[root@bar]# lsmod | grep sctp
[root@bar]# ./a.out
[root@bar]# lsmod | grep sctp
sctp 1077248 4
libcrc32c 16384 3 nf_conntrack,nf_nat,sctp
[root@bar]#
Fix it by adding module alias to TCP ULP modules, so probing module
via request_module() will be limited to tcp-ulp-[name]. The existing
modules like kTLS will load fine given tcp-ulp-tls alias, but others
will fail to load:
[root@bar]# lsmod | grep sctp
[root@bar]# ./a.out
[root@bar]# lsmod | grep sctp
[root@bar]#
Sockmap is not affected from this since it's either built-in or not.
Fixes: 734942cc4e ("tcp: ULP infrastructure")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2018-08-13
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Add driver XDP support for veth. This can be used in conjunction with
redirect of another XDP program e.g. sitting on NIC so the xdp_frame
can be forwarded to the peer veth directly without modification,
from Toshiaki.
2) Add a new BPF map type REUSEPORT_SOCKARRAY and prog type SK_REUSEPORT
in order to provide more control and visibility on where a SO_REUSEPORT
sk should be located, and the latter enables to directly select a sk
from the bpf map. This also enables map-in-map for application migration
use cases, from Martin.
3) Add a new BPF helper bpf_skb_ancestor_cgroup_id() that returns the id
of cgroup v2 that is the ancestor of the cgroup associated with the
skb at the ancestor_level, from Andrey.
4) Implement BPF fs map pretty-print support based on BTF data for regular
hash table and LRU map, from Yonghong.
5) Decouple the ability to attach BTF for a map from the key and value
pretty-printer in BPF fs, and enable further support of BTF for maps for
percpu and LPM trie, from Daniel.
6) Implement a better BPF sample of using XDP's CPU redirect feature for
load balancing SKB processing to remote CPU. The sample implements the
same XDP load balancing as Suricata does which is symmetric hash based
on IP and L4 protocol, from Jesper.
7) Revert adding NULL pointer check with WARN_ON_ONCE() in __xdp_return()'s
critical path as it is ensured that the allocator is present, from Björn.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch changes the runtime behavior of IP defrag queue:
incoming in-order fragments are added to the end of the current
list/"run" of in-order fragments at the tail.
On some workloads, UDP stream performance is substantially improved:
RX: ./udp_stream -F 10 -T 2 -l 60
TX: ./udp_stream -c -H <host> -F 10 -T 5 -l 60
with this patchset applied on a 10Gbps receiver:
throughput=9524.18
throughput_units=Mbit/s
upstream (net-next):
throughput=4608.93
throughput_units=Mbit/s
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch introduces several helper functions/macros that will be
used in the follow-up patch. No runtime changes yet.
The new logic (fully implemented in the second patch) is as follows:
* Nodes in the rb-tree will now contain not single fragments, but lists
of consecutive fragments ("runs").
* At each point in time, the current "active" run at the tail is
maintained/tracked. Fragments that arrive in-order, adjacent
to the previous tail fragment, are added to this tail run without
triggering the re-balancing of the rb-tree.
* If a fragment arrives out of order with the offset _before_ the tail run,
it is inserted into the rb-tree as a single fragment.
* If a fragment arrives after the current tail fragment (with a gap),
it starts a new "tail" run, as is inserted into the rb-tree
at the end as the head of the new run.
skb->cb is used to store additional information
needed here (suggested by Eric Dumazet).
Reported-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
RFC 5681 sec 4.2:
To provide feedback to senders recovering from losses, the receiver
SHOULD send an immediate ACK when it receives a data segment that
fills in all or part of a gap in the sequence space.
When a gap is partially filled, __tcp_ack_snd_check already checks
the out-of-order queue and correctly send an immediate ACK. However
when a gap is fully filled, the previous implementation only resets
pingpong mode which does not guarantee an immediate ACK because the
quick ACK counter may be zero. This patch addresses this issue by
marking the one-time immediate ACK flag instead.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The recent fix of acking immediately in DCTCP on CE status change
has an undesirable side-effect: it also resets TCP ack timer and
disables pingpong mode (interactive session). But the CE status
change has nothing to do with them. This patch addresses that by
using the new one-time immediate ACK flag instead of calling
tcp_enter_quickack_mode().
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new flag to indicate a one-time immediate ACK. This flag is
occasionaly set under specific TCP protocol states in addition to
the more common quickack mechanism for interactive application.
In several cases in the TCP code we want to force an immediate ACK
but do not want to call tcp_enter_quickack_mode() because we do
not want to forget the icsk_ack.pingpong or icsk_ack.ato state.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows a BPF_PROG_TYPE_SK_REUSEPORT bpf prog to select a
SO_REUSEPORT sk from a BPF_MAP_TYPE_REUSEPORT_ARRAY introduced in
the earlier patch. "bpf_run_sk_reuseport()" will return -ECONNREFUSED
when the BPF_PROG_TYPE_SK_REUSEPORT prog returns SK_DROP.
The callers, in inet[6]_hashtable.c and ipv[46]/udp.c, are modified to
handle this case and return NULL immediately instead of continuing the
sk search from its hashtable.
It re-uses the existing SO_ATTACH_REUSEPORT_EBPF setsockopt to attach
BPF_PROG_TYPE_SK_REUSEPORT. The "sk_reuseport_attach_bpf()" will check
if the attaching bpf prog is in the new SK_REUSEPORT or the existing
SOCKET_FILTER type and then check different things accordingly.
One level of "__reuseport_attach_prog()" call is removed. The
"sk_unhashed() && ..." and "sk->sk_reuseport_cb" tests are pushed
back to "reuseport_attach_prog()" in sock_reuseport.c. sock_reuseport.c
seems to have more knowledge on those test requirements than filter.c.
In "reuseport_attach_prog()", after new_prog is attached to reuse->prog,
the old_prog (if any) is also directly freed instead of returning the
old_prog to the caller and asking the caller to free.
The sysctl_optmem_max check is moved back to the
"sk_reuseport_attach_filter()" and "sk_reuseport_attach_bpf()".
As of other bpf prog types, the new BPF_PROG_TYPE_SK_REUSEPORT is only
bounded by the usual "bpf_prog_charge_memlock()" during load time
instead of bounded by both bpf_prog_charge_memlock and sysctl_optmem_max.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch adds a BPF_PROG_TYPE_SK_REUSEPORT which can select
a SO_REUSEPORT sk from a BPF_MAP_TYPE_REUSEPORT_ARRAY. Like other
non SK_FILTER/CGROUP_SKB program, it requires CAP_SYS_ADMIN.
BPF_PROG_TYPE_SK_REUSEPORT introduces "struct sk_reuseport_kern"
to store the bpf context instead of using the skb->cb[48].
At the SO_REUSEPORT sk lookup time, it is in the middle of transiting
from a lower layer (ipv4/ipv6) to a upper layer (udp/tcp). At this
point, it is not always clear where the bpf context can be appended
in the skb->cb[48] to avoid saving-and-restoring cb[]. Even putting
aside the difference between ipv4-vs-ipv6 and udp-vs-tcp. It is not
clear if the lower layer is only ipv4 and ipv6 in the future and
will it not touch the cb[] again before transiting to the upper
layer.
For example, in udp_gro_receive(), it uses the 48 byte NAPI_GRO_CB
instead of IP[6]CB and it may still modify the cb[] after calling
the udp[46]_lib_lookup_skb(). Because of the above reason, if
sk->cb is used for the bpf ctx, saving-and-restoring is needed
and likely the whole 48 bytes cb[] has to be saved and restored.
Instead of saving, setting and restoring the cb[], this patch opts
to create a new "struct sk_reuseport_kern" and setting the needed
values in there.
The new BPF_PROG_TYPE_SK_REUSEPORT and "struct sk_reuseport_(kern|md)"
will serve all ipv4/ipv6 + udp/tcp combinations. There is no protocol
specific usage at this point and it is also inline with the current
sock_reuseport.c implementation (i.e. no protocol specific requirement).
In "struct sk_reuseport_md", this patch exposes data/data_end/len
with semantic similar to other existing usages. Together
with "bpf_skb_load_bytes()" and "bpf_skb_load_bytes_relative()",
the bpf prog can peek anywhere in the skb. The "bind_inany" tells
the bpf prog that the reuseport group is bind-ed to a local
INANY address which cannot be learned from skb.
The new "bind_inany" is added to "struct sock_reuseport" which will be
used when running the new "BPF_PROG_TYPE_SK_REUSEPORT" bpf prog in order
to avoid repeating the "bind INANY" test on
"sk_v6_rcv_saddr/sk->sk_rcv_saddr" every time a bpf prog is run. It can
only be properly initialized when a "sk->sk_reuseport" enabled sk is
adding to a hashtable (i.e. during "reuseport_alloc()" and
"reuseport_add_sock()").
The new "sk_select_reuseport()" is the main helper that the
bpf prog will use to select a SO_REUSEPORT sk. It is the only function
that can use the new BPF_MAP_TYPE_REUSEPORT_ARRAY. As mentioned in
the earlier patch, the validity of a selected sk is checked in
run time in "sk_select_reuseport()". Doing the check in
verification time is difficult and inflexible (consider the map-in-map
use case). The runtime check is to compare the selected sk's reuseport_id
with the reuseport_id that we want. This helper will return -EXXX if the
selected sk cannot serve the incoming request (e.g. reuseport_id
not match). The bpf prog can decide if it wants to do SK_DROP as its
discretion.
When the bpf prog returns SK_PASS, the kernel will check if a
valid sk has been selected (i.e. "reuse_kern->selected_sk != NULL").
If it does , it will use the selected sk. If not, the kernel
will select one from "reuse->socks[]" (as before this patch).
The SK_DROP and SK_PASS handling logic will be in the next patch.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
We accidentally removed the parentheses here, but they are required
because '!' has higher precedence than '&'.
Fixes: fa0f527358 ("ip: use rb trees for IP frag queue.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
