Conflicts:
net/ipv4/arp.c
The net/ipv4/arp.c conflict was one commit adding a new
local variable while another commit was deleting one.
Signed-off-by: David S. Miller <davem@davemloft.net>
SYNACK packets are sent on behalf on unlocked listeners
or fastopen sockets. Mark socket as const to catch future changes
that might break the assumption.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is done to make sure we do not change listener socket
while sending SYNACK packets while socket lock is not held.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This documents fact that listener lock might not be held
at the time SYNACK are sent.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
listener socket is not locked when tcp_make_synack() is called.
We better make sure no field is written.
There is one exception : Since SYNACK packets are attached to the listener
at this moment (or SYN_RECV child in case of Fast Open),
sock_wmalloc() needs to update sk->sk_wmem_alloc, but this is done using
atomic operations so this is safe.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SYNACK packets might be sent without holding socket lock.
For DCTCP/ECN sake, we should call INET_ECN_xmit() while
socket lock is owned, and only when we init/change congestion control.
This also fixies a bug if congestion module is changed from
dctcp to another one on a listener : we now clear ECN bits
properly.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This function is used to build and send SYNACK packets,
possibly on behalf of unlocked listener socket.
Make sure we did not miss a write by making this socket const.
We no longer can use ip_select_ident() and have to either
set iph->id to 0 or directly call __ip_select_ident()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When TCP new listener is done, these functions will be called
without socket lock being held. Make sure they don't change
anything.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is used by TCP listener core, and listener socket shall
not be modified by inet_csk_route_req().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Very soon, TCP stack might call inet_csk_route_req(), which
calls inet_csk_route_req() with an unlocked listener socket,
so we need to make sure ip_route_output_flow() is not trying to
change any field from its socket argument.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Soon, listener socket wont be locked when tcp_openreq_init_rwin()
is called. We need to read socket fields once, as their value
could change under us.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Soon, listener socket spinlock will no longer be held,
add const arguments to tcp_v[46]_init_req() to make clear these
functions can not mess socket fields.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Neal suggested to move sk_txhash init into tcp_create_openreq_child(),
called both from IPv4 and IPv6.
This opportunity was missed in commit 58d607d3e5 ("tcp: provide
skb->hash to synack packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The UDP tunnel config is asymmetric wrt. to the ports used. The source and
destination ports from one direction of the tunnel are not related to the
ports of the other direction. We need to be able to respond to ARP requests
using the correct ports without involving routing.
As the consequence, UDP ports need to be fixed property of the tunnel
interface and cannot be set per route. Remove the ability to set ports per
route. This is still okay to do, as no kernel has been released with these
attributes yet.
Note that the ability to specify source and destination ports is preserved
for other users of the lwtunnel API which don't use routes for tunnel key
specification (like openvswitch).
If in the future we rework ARP handling to allow port specification, the
attributes can be added back.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
When using ip lwtunnels, the additional data for xmit (basically, the actual
tunnel to use) are carried in ip_tunnel_info either in dst->lwtstate or in
metadata dst. When replying to ARP requests, we need to send the reply to
the same tunnel the request came from. This means we need to construct
proper metadata dst for ARP replies.
We could perform another route lookup to get a dst entry with the correct
lwtstate. However, this won't always ensure that the outgoing tunnel is the
same as the incoming one, and it won't work anyway for IPv4 duplicate
address detection.
The only thing to do is to "reverse" the ip_tunnel_info.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
RST packets sent on behalf of TCP connections with TS option (RFC 7323
TCP timestamps) have incorrect TS val (set to 0), but correct TS ecr.
A > B: Flags [S], seq 0, win 65535, options [mss 1000,nop,nop,TS val 100
ecr 0], length 0
B > A: Flags [S.], seq 2444755794, ack 1, win 28960, options [mss
1460,nop,nop,TS val 7264344 ecr 100], length 0
A > B: Flags [.], ack 1, win 65535, options [nop,nop,TS val 110 ecr
7264344], length 0
B > A: Flags [R.], seq 1, ack 1, win 28960, options [nop,nop,TS val 0
ecr 110], length 0
We need to call skb_mstamp_get() to get proper TS val,
derived from skb->skb_mstamp
Note that RFC 1323 was advocating to not send TS option in RST segment,
but RFC 7323 recommends the opposite :
Once TSopt has been successfully negotiated, that is both <SYN> and
<SYN,ACK> contain TSopt, the TSopt MUST be sent in every non-<RST>
segment for the duration of the connection, and SHOULD be sent in an
<RST> segment (see Section 5.2 for details)
Note this RFC recommends to send TS val = 0, but we believe it is
premature : We do not know if all TCP stacks are properly
handling the receive side :
When an <RST> segment is
received, it MUST NOT be subjected to the PAWS check by verifying an
acceptable value in SEG.TSval, and information from the Timestamps
option MUST NOT be used to update connection state information.
SEG.TSecr MAY be used to provide stricter <RST> acceptance checks.
In 5 years, if/when all TCP stack are RFC 7323 ready, we might consider
to decide to send TS val = 0, if it buys something.
Fixes: 7faee5c0d5 ("tcp: remove TCP_SKB_CB(skb)->when")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for your net-next tree
in this 4.4 development cycle, they are:
1) Schedule ICMP traffic to IPVS instances, this introduces a new schedule_icmp
proc knob to enable/disable it. By default is off to retain the old
behaviour. Patchset from Alex Gartrell.
I'm also including what Alex originally said for the record:
"The configuration of ipvs at Facebook is relatively straightforward. All
ipvs instances bgp advertise a set of VIPs and the network prefers the
nearest one or uses ECMP in the event of a tie. For the uninitiated, ECMP
deterministically and statelessly load balances by hashing the packet
(usually a 5-tuple of protocol, saddr, daddr, sport, and dport) and using
that number as an index (basic hash table type logic).
The problem is that ICMP packets (which contain really important
information like whether or not an MTU has been exceeded) will get a
different hash value and may end up at a different ipvs instance. With no
information about where to route these packets, they are dropped, creating
ICMP black holes and breaking Path MTU discovery. Suddenly, my mom's
pictures can't load and I'm fielding midday calls that I want nothing to do
with.
To address this, this patch set introduces the ability to schedule icmp
packets which is gated by a sysctl net.ipv4.vs.schedule_icmp. If set to 0,
the old behavior is maintained -- otherwise ICMP packets are scheduled."
2) Add another proc entry to ignore tunneled packets to avoid routing loops
from IPVS, also from Alex.
3) Fifteen patches from Eric Biederman to:
* Stop passing nf_hook_ops as parameter to the hook and use the state hook
object instead all around the netfilter code, so only the private data
pointer is passed to the registered hook function.
* Now that we've got state->net, propagate the netns pointer to netfilter hook
clients to avoid its computation over and over again. A good example of how
this has been simplified is the former TEE target (now nf_dup infrastructure)
since it has killed the ugly pick_net() function.
There's another round of netns updates from Eric Biederman making the line. To
avoid the patchbomb again to almost all the networking mailing list (that is 84
patches) I'd suggest we send you a pull request with no patches or let me know
if you prefer a better way.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Before allowing lockless LISTEN processing, we need to make
sure to arm the SYN_RECV timer before the req socket is visible
in hash tables.
Also, req->rsk_hash should be written before we set rsk_refcnt
to a non zero value.
Fixes: fa76ce7328 ("inet: get rid of central tcp/dccp listener timer")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ying Cai <ycai@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When creating a timewait socket, we need to arm the timer before
allowing other cpus to find it. The signal allowing cpus to find
the socket is setting tw_refcnt to non zero value.
As we set tw_refcnt in __inet_twsk_hashdance(), we therefore need to
call inet_twsk_schedule() first.
This also means we need to remove tw_refcnt changes from
inet_twsk_schedule() and let the caller handle it.
Note that because we use mod_timer_pinned(), we have the guarantee
the timer wont expire before we set tw_refcnt as we run in BH context.
To make things more readable I introduced inet_twsk_reschedule() helper.
When rearming the timer, we can use mod_timer_pending() to make sure
we do not rearm a canceled timer.
Note: This bug can possibly trigger if packets of a flow can hit
multiple cpus. This does not normally happen, unless flow steering
is broken somehow. This explains this bug was spotted ~5 months after
its introduction.
A similar fix is needed for SYN_RECV sockets in reqsk_queue_hash_req(),
but will be provided in a separate patch for proper tracking.
Fixes: 789f558cfb ("tcp/dccp: get rid of central timewait timer")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Ying Cai <ycai@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch makes TLP to use 1 sec timer by default when RTT is
not available due to SYN/ACK retransmission or SYN cookies.
Prior to this change, the lack of RTT prevents TLP so the first
data packets sent can only be recovered by fast recovery or RTO.
If the fast recovery fails to trigger the RTO is 3 second when
SYN/ACK is retransmitted. With this patch we can trigger fast
recovery in 1sec instead.
Note that we need to check Fast Open more properly. A Fast Open
connection could be (accepted then) closed before it receives
the final ACK of 3WHS so the state is FIN_WAIT_1. Without the
new check, TLP will retransmit FIN instead of SYN/ACK.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Nandita Dukkipati <nanditad@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently SYN/ACK RTT is measured in jiffies. For LAN the SYN/ACK
RTT is often measured as 0ms or sometimes 1ms, which would affect
RTT estimation and min RTT samping used by some congestion control.
This patch improves SYN/ACK RTT to be usec resolution if platform
supports it. While the timestamping of SYN/ACK is done in request
sock, the RTT measurement is carefully arranged to avoid storing
another u64 timestamp in tcp_sock.
For regular handshake w/o SYNACK retransmission, the RTT is sampled
right after the child socket is created and right before the request
sock is released (tcp_check_req() in tcp_minisocks.c)
For Fast Open the child socket is already created when SYN/ACK was
sent, the RTT is sampled in tcp_rcv_state_process() after processing
the final ACK an right before the request socket is released.
If the SYN/ACK was retransmistted or SYN-cookie was used, we rely
on TCP timestamps to measure the RTT. The sample is taken at the
same place in tcp_rcv_state_process() after the timestamp values
are validated in tcp_validate_incoming(). Note that we do not store
TS echo value in request_sock for SYN-cookies, because the value
is already stored in tp->rx_opt used by tcp_ack_update_rtt().
One side benefit is that the RTT measurement now happens before
initializing congestion control (of the passive side). Therefore
the congestion control can use the SYN/ACK RTT.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This was already done a long time ago in
commit 64194c31a0 ("inet: Make tunnel RX/TX byte counters more consistent")
but tx path was broken (at least since 3.10).
Before the patch the gre header was included on tx.
After the patch:
$ ping -c1 192.168.0.121 ; ip -s l ls dev gre1
PING 192.168.0.121 (192.168.0.121) 56(84) bytes of data.
64 bytes from 192.168.0.121: icmp_req=1 ttl=64 time=2.95 ms
--- 192.168.0.121 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 2.955/2.955/2.955/0.000 ms
7: gre1@NONE: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1468 qdisc noqueue state UNKNOWN mode DEFAULT group default
link/gre 10.16.0.249 peer 10.16.0.121
RX: bytes packets errors dropped overrun mcast
84 1 0 0 0 0
TX: bytes packets errors dropped carrier collsns
84 1 0 0 0 0
Reported-by: Julien Meunier <julien.meunier@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Man page of ip-route(8) says following about route types:
unreachable - these destinations are unreachable. Packets are dis‐
carded and the ICMP message host unreachable is generated. The local
senders get an EHOSTUNREACH error.
blackhole - these destinations are unreachable. Packets are dis‐
carded silently. The local senders get an EINVAL error.
prohibit - these destinations are unreachable. Packets are discarded
and the ICMP message communication administratively prohibited is
generated. The local senders get an EACCES error.
In the inet6 address family, this was correct, except the local senders
got ENETUNREACH error instead of EHOSTUNREACH in case of unreachable route.
In the inet address family, all three route types generated ICMP message
net unreachable, and the local senders got ENETUNREACH error.
In both address families all three route types now behave consistently
with documentation.
Signed-off-by: Nikola Forró <nforro@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller
David Ahern
Eric Dumazet
Jiri Benc
Yuchung Cheng
Nicolas Dichtel
Nikola Forró