Adding delays to TCP flows is crucial for studying behavior
of TCP stacks, including congestion control modules.
Linux offers netem module, but it has unpractical constraints :
- Need root access to change qdisc
- Hard to setup on egress if combined with non trivial qdisc like FQ
- Single delay for all flows.
EDT (Earliest Departure Time) adoption in TCP stack allows us
to enable a per socket delay at a very small cost.
Networking tools can now establish thousands of flows, each of them
with a different delay, simulating real world conditions.
This requires FQ packet scheduler or a EDT-enabled NIC.
This patchs adds TCP_TX_DELAY socket option, to set a delay in
usec units.
unsigned int tx_delay = 10000; /* 10 msec */
setsockopt(fd, SOL_TCP, TCP_TX_DELAY, &tx_delay, sizeof(tx_delay));
Note that FQ packet scheduler limits might need some tweaking :
man tc-fq
PARAMETERS
limit
Hard limit on the real queue size. When this limit is
reached, new packets are dropped. If the value is lowered,
packets are dropped so that the new limit is met. Default
is 10000 packets.
flow_limit
Hard limit on the maximum number of packets queued per
flow. Default value is 100.
Use of TCP_TX_DELAY option will increase number of skbs in FQ qdisc,
so packets would be dropped if any of the previous limit is hit.
Use of a jump label makes this support runtime-free, for hosts
never using the option.
Also note that TSQ (TCP Small Queues) limits are slightly changed
with this patch : we need to account that skbs artificially delayed
wont stop us providind more skbs to feed the pipe (netem uses
skb_orphan_partial() for this purpose, but FQ can not use this trick)
Because of that, using big delays might very well trigger
old bugs in TSO auto defer logic and/or sndbuf limited detection.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In case autoflowlabel is in action, skb_get_hash_flowi6()
derives a non zero skb->hash to the flowlabel.
If skb->hash is zero, a flow dissection is performed.
Since all TCP skbs sent from ESTABLISH state inherit their
skb->hash from sk->sk_txhash, we better keep a copy
of sk->sk_txhash into the TIME_WAIT socket.
After this patch, ACK or RST packets sent on behalf of
a TIME_WAIT socket have the flowlabel that was previously
used by the flow.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
syzbot found a crash in tcp_v6_send_reset() caused by my latest
change.
Problem is that if an skb has been queued to socket prequeue,
skb_dst(skb)->dev can not anymore point to the device.
Fortunately in this case the socket pointer is not NULL.
A similar issue has been fixed in commit 0f85feae6b ("tcp: fix
more NULL deref after prequeue changes"), I should have known better.
Fixes: 323a53c412 ("ipv6: tcp: enable flowlabel reflection in some RST packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some ISDN files that got removed in net-next had some changes
done in mainline, take the removals.
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit 1d13a96c74 ("ipv6: tcp: fix flowlabel value in ACK
messages"), we stored in tw_flowlabel the flowlabel, in the
case ACK packets needed to be sent on behalf of a TIME_WAIT socket.
We can use the same field so that RST packets sent from
TIME_WAIT state also use a consistent flowlabel.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
When RST packets are sent because no socket could be found,
it makes sense to use flowlabel_reflect sysctl to decide
if a reflection of the flowlabel is requested.
This extends commit 22b6722bfa ("ipv6: Add sysctl for per
namespace flow label reflection"), for some TCP RST packets.
In order to provide full control of this new feature,
flowlabel_reflect becomes a bitmask.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
So that we avoid another indirect call per RX packet, if
early demux is enabled.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
So that we avoid another indirect call per RX packet in the common
case.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It turns out that struct ipv6_pinfo is not located as we think.
inet6_sk_generic() and tcp_inet6_sk() disagree on 32bit kernels by 4-bytes,
because struct tcp_sock has 8-bytes alignment,
but ipv6_pinfo size is not a multiple of 8.
sizeof(struct ipv6_pinfo): 116 (not padded to 8)
I actually first coded tcp_inet6_sk() as this patch does, but thought
that "container_of(tcp_sk(sk), struct tcp6_sock, tcp)" was cleaner.
As Julian told me : Nobody should use tcp6_sock.inet6
directly, it should be accessed via tcp_inet6_sk() or inet6_sk().
This happened when we added the first u64 field in struct tcp_sock.
Fixes: 93a77c11ae ("tcp: add tcp_inet6_sk() helper")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Bisected-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Often times, recvmsg() system calls and BH handling for a particular
TCP socket are done on different cpus.
This means the incoming skb had to be allocated on a cpu,
but freed on another.
This incurs a high spinlock contention in slab layer for small rpc,
but also a high number of cache line ping pongs for larger packets.
A full size GRO packet might use 45 page fragments, meaning
that up to 45 put_page() can be involved.
More over performing the __kfree_skb() in the recvmsg() context
adds a latency for user applications, and increase probability
of trapping them in backlog processing, since the BH handler
might found the socket owned by the user.
This patch, combined with the prior one increases the rpc
performance by about 10 % on servers with large number of cores.
(tcp_rr workload with 10,000 flows and 112 threads reach 9 Mpps
instead of 8 Mpps)
This also increases single bulk flow performance on 40Gbit+ links,
since in this case there are often two cpus working in tandem :
- CPU handling the NIC rx interrupts, feeding the receive queue,
and (after this patch) freeing the skbs that were consumed.
- CPU in recvmsg() system call, essentially 100 % busy copying out
data to user space.
Having at most one skb in a per-socket cache has very little risk
of memory exhaustion, and since it is protected by socket lock,
its management is essentially free.
Note that if rps/rfs is used, we do not enable this feature, because
there is high chance that the same cpu is handling both the recvmsg()
system call and the TCP rx path, but that another cpu did the skb
allocations in the device driver right before the RPS/RFS logic.
To properly handle this case, it seems we would need to record
on which cpu skb was allocated, and use a different channel
to give skbs back to this cpu.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP ipv6 fast path dereferences a pointer to get to the inet6
part of a tcp socket, but given the fixed memory placement,
we can do better and avoid a possible cache line miss.
This also reduces register pressure, since we let the compiler
know about this memory placement.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a dual stack tcp listener accepts an ipv4 flow,
it should not attempt to use an ipv6 header or tcp_v6_iif() helper.
Fixes: 1397ed35f2 ("ipv6: add flowinfo for tcp6 pkt_options for all cases")
Fixes: df3687ffc6 ("ipv6: add the IPV6_FL_F_REFLECT flag to IPV6_FL_A_GET")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of using pingpong as a single bit information, we refactor the
code to treat it as a counter. When interactive session is detected,
we set pingpong count to TCP_PINGPONG_THRESH. And when pingpong count
is >= TCP_PINGPONG_THRESH, we consider the session in pingpong mode.
This patch is a pure refactor and sets foundation for the next patch.
This patch itself does not change any pingpong logic.
Signed-off-by: Wei Wang <weiwan@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>
A recent commit allows sockets bound to a VRF to receive ipv6 link local
packets. However, it only works for UDP and worse TCP connection attempts
to the LLA with the only listener bound to the VRF just hang where as
before the client gets a reset and connection refused. Fix by adjusting
ir_iif for LL addresses and packets received through a device enslaved
to a VRF.
Fixes: 6f12fa7755 ("vrf: mark skb for multicast or link-local as enslaved to VRF")
Reported-by: Donald Sharp <sharpd@cumulusnetworks.com>
Cc: Mike Manning <mmanning@vyatta.att-mail.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We'll need this to handle ICMP errors for tunnels without a sending socket
(i.e. FoU and GUE). There, we might have to look up different types of IP
tunnels, registered as network protocols, before we get a match, so we
want this for the error handlers of IPPROTO_IPIP and IPPROTO_IPV6 in both
inet_protos and inet6_protos. These error codes will be used in the next
patch.
For consistency, return sensible error codes in protocol error handlers
whenever handlers can't handle errors because, even if valid, they don't
match a protocol or any of its states.
This has no effect on existing error handling paths.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Example setup:
host: ip -6 addr add dev eth1 2001:db8:104::4
where eth1 is enslaved to a VRF
switch: ip -6 ro add 2001:db8:104::4/128 dev br1
where br1 only has an LLA
ping6 2001:db8:104::4
ssh 2001:db8:104::4
(NOTE: UDP works fine if the PKTINFO has the address set to the global
address and ifindex is set to the index of eth1 with a destination an
LLA).
For ICMP, icmp6_iif needs to be updated to check if skb->dev is an
L3 master. If it is then return the ifindex from rt6i_idev similar
to what is done for loopback.
For TCP, restore the original tcp_v6_iif definition which is needed in
most places and add a new tcp_v6_iif_l3_slave that considers the
l3_slave variability. This latter check is only needed for socket
lookups.
Fixes: 9ff7438460 ("net: vrf: Handle ipv6 multicast and link-local addresses")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 079096f103 ("tcp/dccp: install syn_recv requests into ehash
table") introduced an optimization for the handling of child sockets
created for a new TCP connection.
But this optimization passes any data associated with the last ACK of the
connection handshake up the stack without verifying its checksum, because it
calls tcp_child_process(), which in turn calls tcp_rcv_state_process()
directly. These lower-level processing functions do not do any checksum
verification.
Insert a tcp_checksum_complete call in the TCP_NEW_SYN_RECEIVE path to
fix this.
Fixes: 079096f103 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Balbir Singh <bsingharora@gmail.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking updates from David Miller:
1) Add Maglev hashing scheduler to IPVS, from Inju Song.
2) Lots of new TC subsystem tests from Roman Mashak.
3) Add TCP zero copy receive and fix delayed acks and autotuning with
SO_RCVLOWAT, from Eric Dumazet.
4) Add XDP_REDIRECT support to mlx5 driver, from Jesper Dangaard
Brouer.
5) Add ttl inherit support to vxlan, from Hangbin Liu.
6) Properly separate ipv6 routes into their logically independant
components. fib6_info for the routing table, and fib6_nh for sets of
nexthops, which thus can be shared. From David Ahern.
7) Add bpf_xdp_adjust_tail helper, which can be used to generate ICMP
messages from XDP programs. From Nikita V. Shirokov.
8) Lots of long overdue cleanups to the r8169 driver, from Heiner
Kallweit.
9) Add BTF ("BPF Type Format"), from Martin KaFai Lau.
10) Add traffic condition monitoring to iwlwifi, from Luca Coelho.
11) Plumb extack down into fib_rules, from Roopa Prabhu.
12) Add Flower classifier offload support to igb, from Vinicius Costa
Gomes.
13) Add UDP GSO support, from Willem de Bruijn.
14) Add documentation for eBPF helpers, from Quentin Monnet.
15) Add TLS tx offload to mlx5, from Ilya Lesokhin.
16) Allow applications to be given the number of bytes available to read
on a socket via a control message returned from recvmsg(), from
Soheil Hassas Yeganeh.
17) Add x86_32 eBPF JIT compiler, from Wang YanQing.
18) Add AF_XDP sockets, with zerocopy support infrastructure as well.
From Björn Töpel.
19) Remove indirect load support from all of the BPF JITs and handle
these operations in the verifier by translating them into native BPF
instead. From Daniel Borkmann.
20) Add GRO support to ipv6 gre tunnels, from Eran Ben Elisha.
21) Allow XDP programs to do lookups in the main kernel routing tables
for forwarding. From David Ahern.
22) Allow drivers to store hardware state into an ELF section of kernel
dump vmcore files, and use it in cxgb4. From Rahul Lakkireddy.
23) Various RACK and loss detection improvements in TCP, from Yuchung
Cheng.
24) Add TCP SACK compression, from Eric Dumazet.
25) Add User Mode Helper support and basic bpfilter infrastructure, from
Alexei Starovoitov.
26) Support ports and protocol values in RTM_GETROUTE, from Roopa
Prabhu.
27) Support bulking in ->ndo_xdp_xmit() API, from Jesper Dangaard
Brouer.
28) Add lots of forwarding selftests, from Petr Machata.
29) Add generic network device failover driver, from Sridhar Samudrala.
* ra.kernel.org:/pub/scm/linux/kernel/git/davem/net-next: (1959 commits)
strparser: Add __strp_unpause and use it in ktls.
rxrpc: Fix terminal retransmission connection ID to include the channel
net: hns3: Optimize PF CMDQ interrupt switching process
net: hns3: Fix for VF mailbox receiving unknown message
net: hns3: Fix for VF mailbox cannot receiving PF response
bnx2x: use the right constant
Revert "net: sched: cls: Fix offloading when ingress dev is vxlan"
net: dsa: b53: Fix for brcm tag issue in Cygnus SoC
enic: fix UDP rss bits
netdev-FAQ: clarify DaveM's position for stable backports
rtnetlink: validate attributes in do_setlink()
mlxsw: Add extack messages for port_{un, }split failures
netdevsim: Add extack error message for devlink reload
devlink: Add extack to reload and port_{un, }split operations
net: metrics: add proper netlink validation
ipmr: fix error path when ipmr_new_table fails
ip6mr: only set ip6mr_table from setsockopt when ip6mr_new_table succeeds
net: hns3: remove unused hclgevf_cfg_func_mta_filter
netfilter: provide udp*_lib_lookup for nf_tproxy
qed*: Utilize FW 8.37.2.0
...
This is additional to the
commit ea1627c20c ("tcp: minor optimizations around tcp_hdr() usage").
At this point, skb->data is same with tcp_hdr() as tcp header has not
been pulled yet. So use the less expensive one to get the tcp header.
Remove the third parameter of tcp_rcv_established() and put it into
the function body.
Furthermore, the local variables are listed as a reverse christmas tree :)
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Variants of proc_create{,_data} that directly take a struct seq_operations
and deal with network namespaces in ->open and ->release. All callers of
proc_create + seq_open_net converted over, and seq_{open,release}_net are
removed entirely.
Signed-off-by: Christoph Hellwig <hch@lst.de>
This version has some suggestions by Eric Dumazet:
- Use a local variable for the mark in IPv6 instead of ctl_sk to avoid SMP
races.
- Use the more elegant "IP4_REPLY_MARK(net, skb->mark) ?: sk->sk_mark"
statement.
- Factorize code as sk_fullsock() check is not necessary.
Aidan McGurn from Openwave Mobility systems reported the following bug:
"Marked routing is broken on customer deployment. Its effects are large
increase in Uplink retransmissions caused by the client never receiving
the final ACK to their FINACK - this ACK misses the mark and routes out
of the incorrect route."
Currently marks are added to sk_buffs for replies when the "fwmark_reflect"
sysctl is enabled. But not for TW sockets that had sk->sk_mark set via
setsockopt(SO_MARK..).
Fix this in IPv4/v6 by adding tw->tw_mark for TIME_WAIT sockets. Copy the the
original sk->sk_mark in __inet_twsk_hashdance() to the new tw->tw_mark location.
Then progate this so that the skb gets sent with the correct mark. Do the same
for resets. Give the "fwmark_reflect" sysctl precedence over sk->sk_mark so that
netfilter rules are still honored.
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
pull-request: bpf-next 2018-03-31
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Add raw BPF tracepoint API in order to have a BPF program type that
can access kernel internal arguments of the tracepoints in their
raw form similar to kprobes based BPF programs. This infrastructure
also adds a new BPF_RAW_TRACEPOINT_OPEN command to BPF syscall which
returns an anon-inode backed fd for the tracepoint object that allows
for automatic detach of the BPF program resp. unregistering of the
tracepoint probe on fd release, from Alexei.
2) Add new BPF cgroup hooks at bind() and connect() entry in order to
allow BPF programs to reject, inspect or modify user space passed
struct sockaddr, and as well a hook at post bind time once the port
has been allocated. They are used in FB's container management engine
for implementing policy, replacing fragile LD_PRELOAD wrapper
intercepting bind() and connect() calls that only works in limited
scenarios like glibc based apps but not for other runtimes in
containerized applications, from Andrey.
3) BPF_F_INGRESS flag support has been added to sockmap programs for
their redirect helper call bringing it in line with cls_bpf based
programs. Support is added for both variants of sockmap programs,
meaning for tx ULP hooks as well as recv skb hooks, from John.
4) Various improvements on BPF side for the nfp driver, besides others
this work adds BPF map update and delete helper call support from
the datapath, JITing of 32 and 64 bit XADD instructions as well as
offload support of bpf_get_prandom_u32() call. Initial implementation
of nfp packet cache has been tackled that optimizes memory access
(see merge commit for further details), from Jakub and Jiong.
5) Removal of struct bpf_verifier_env argument from the print_bpf_insn()
API has been done in order to prepare to use print_bpf_insn() soon
out of perf tool directly. This makes the print_bpf_insn() API more
generic and pushes the env into private data. bpftool is adjusted
as well with the print_bpf_insn() argument removal, from Jiri.
6) Couple of cleanups and prep work for the upcoming BTF (BPF Type
Format). The latter will reuse the current BPF verifier log as
well, thus bpf_verifier_log() is further generalized, from Martin.
7) For bpf_getsockopt() and bpf_setsockopt() helpers, IPv4 IP_TOS read
and write support has been added in similar fashion to existing
IPv6 IPV6_TCLASS socket option we already have, from Nikita.
8) Fixes in recent sockmap scatterlist API usage, which did not use
sg_init_table() for initialization thus triggering a BUG_ON() in
scatterlist API when CONFIG_DEBUG_SG was enabled. This adds and
uses a small helper sg_init_marker() to properly handle the affected
cases, from Prashant.
9) Let the BPF core follow IDR code convention and therefore use the
idr_preload() and idr_preload_end() helpers, which would also help
idr_alloc_cyclic() under GFP_ATOMIC to better succeed under memory
pressure, from Shaohua.
10) Last but not least, a spelling fix in an error message for the
BPF cookie UID helper under BPF sample code, from Colin.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
== The problem ==
See description of the problem in the initial patch of this patch set.
== The solution ==
The patch provides much more reliable in-kernel solution for the 2nd
part of the problem: making outgoing connecttion from desired IP.
It adds new attach types `BPF_CGROUP_INET4_CONNECT` and
`BPF_CGROUP_INET6_CONNECT` for program type
`BPF_PROG_TYPE_CGROUP_SOCK_ADDR` that can be used to override both
source and destination of a connection at connect(2) time.
Local end of connection can be bound to desired IP using newly
introduced BPF-helper `bpf_bind()`. It allows to bind to only IP though,
and doesn't support binding to port, i.e. leverages
`IP_BIND_ADDRESS_NO_PORT` socket option. There are two reasons for this:
* looking for a free port is expensive and can affect performance
significantly;
* there is no use-case for port.
As for remote end (`struct sockaddr *` passed by user), both parts of it
can be overridden, remote IP and remote port. It's useful if an
application inside cgroup wants to connect to another application inside
same cgroup or to itself, but knows nothing about IP assigned to the
cgroup.
Support is added for IPv4 and IPv6, for TCP and UDP.
IPv4 and IPv6 have separate attach types for same reason as sys_bind
hooks, i.e. to prevent reading from / writing to e.g. user_ip6 fields
when user passes sockaddr_in since it'd be out-of-bound.
== Implementation notes ==
The patch introduces new field in `struct proto`: `pre_connect` that is
a pointer to a function with same signature as `connect` but is called
before it. The reason is in some cases BPF hooks should be called way
before control is passed to `sk->sk_prot->connect`. Specifically
`inet_dgram_connect` autobinds socket before calling
`sk->sk_prot->connect` and there is no way to call `bpf_bind()` from
hooks from e.g. `ip4_datagram_connect` or `ip6_datagram_connect` since
it'd cause double-bind. On the other hand `proto.pre_connect` provides a
flexible way to add BPF hooks for connect only for necessary `proto` and
call them at desired time before `connect`. Since `bpf_bind()` is
allowed to bind only to IP and autobind in `inet_dgram_connect` binds
only port there is no chance of double-bind.
bpf_bind() sets `force_bind_address_no_port` to bind to only IP despite
of value of `bind_address_no_port` socket field.
bpf_bind() sets `with_lock` to `false` when calling to __inet_bind()
and __inet6_bind() since all call-sites, where bpf_bind() is called,
already hold socket lock.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations create and destroy net::ipv6.tcp_sk
socket, which is used in tcp_v6_send_response() only. It looks
like foreign pernet_operations don't want to set ipv6 connection
inside destroyed net, so this socket may be created in destroyed
in parallel with anything else. inet_twsk_purge() is also safe
for that, as described in patch for tcp_sk_ops. So, it's possible
to mark them as async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
배석진 reported that in some situations, packets for a given 5-tuple
end up being processed by different CPUS.
This involves RPS, and fragmentation.
배석진 is seeing packet drops when a SYN_RECV request socket is
moved into ESTABLISH state. Other states are protected by socket lock.
This is caused by a CPU losing the race, and simply not caring enough.
Since this seems to occur frequently, we can do better and perform
a second lookup.
Note that all needed memory barriers are already in the existing code,
thanks to the spin_lock()/spin_unlock() pair in inet_ehash_insert()
and reqsk_put(). The second lookup must find the new socket,
unless it has already been accepted and closed by another cpu.
Note that the fragmentation could be avoided in the first place by
use of a correct TCP MSS option in the SYN{ACK} packet, but this
does not mean we can not be more robust.
Many thanks to 배석진 for a very detailed analysis.
Reported-by: 배석진 <soukjin.bae@samsung.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tracepoint tcp_send_reset requires a full socket to work. However, it
may be called when in TCP_TIME_WAIT:
case TCP_TW_RST:
tcp_v6_send_reset(sk, skb);
inet_twsk_deschedule_put(inet_twsk(sk));
goto discard_it;
To avoid this problem, this patch checks the socket with sk_fullsock()
before calling trace_tcp_send_reset().
Fixes: c24b14c46b ("tcp: add tracepoint trace_tcp_send_reset")
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
/proc has been ignoring struct file_operations::owner field for 10 years.
Specifically, it started with commit 786d7e1612
("Fix rmmod/read/write races in /proc entries"). Notice the chunk where
inode->i_fop is initialized with proxy struct file_operations for
regular files:
- if (de->proc_fops)
- inode->i_fop = de->proc_fops;
+ if (de->proc_fops) {
+ if (S_ISREG(inode->i_mode))
+ inode->i_fop = &proc_reg_file_ops;
+ else
+ inode->i_fop = de->proc_fops;
+ }
VFS stopped pinning module at this point.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow a process bound to a VRF to connect to a linklocal address.
Currently, this fails because of a mismatch between the scope of the
linklocal address and the sk_bound_dev_if inherited by the VRF binding:
$ ssh -6 fe80::70b8:cff:fedd:ead8%eth1
ssh: connect to host fe80::70b8:cff:fedd:ead8%eth1 port 22: Invalid argument
Relax the scope check to allow the socket to be bound to the same L3
device as the scope id.
This makes ipv6 linklocal consistent with other relaxed checks enabled
by commits 1ff23beebd ("net: l3mdev: Allow send on enslaved interface")
and 7bb387c5ab ("net: Allow IP_MULTICAST_IF to set index to L3 slave").
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sk_state_load is only used by AF_INET/AF_INET6, so rename it to
inet_sk_state_load and move it into inet_sock.h.
sk_state_store is removed as it is not used any more.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MD5-key that belongs to a connection is identified by the peer's
IP-address. When we are in tcp_v4(6)_reqsk_send_ack(), we are replying
to an incoming segment from tcp_check_req() that failed the seq-number
checks.
Thus, to find the correct key, we need to use the skb's saddr and not
the daddr.
This bug seems to have been there since quite a while, but probably got
unnoticed because the consequences are not catastrophic. We will call
tcp_v4_reqsk_send_ack only to send a challenge-ACK back to the peer,
thus the connection doesn't really fail.
Fixes: 9501f97229 ("tcp md5sig: Let the caller pass appropriate key for tcp_v{4,6}_do_calc_md5_hash().")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tcp_v6_send_reset() expects to receive an skb with skb->cb[] layout as
used in TCP stack.
MD5 lookup uses tcp_v6_iif() and tcp_v6_sdif() and thus
TCP_SKB_CB(skb)->header.h6
This patch probably fixes RST packets sent on behalf of a timewait md5
ipv6 socket.
Before Florian patch, tcp_v6_restore_cb() was needed before jumping to
no_tcp_socket label.
Fixes: 271c3b9b7b ("tcp: honour SO_BINDTODEVICE for TW_RST case too")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Note that when a new netns is created, it inherits its
sysctl_tcp_rmem and sysctl_tcp_wmem from initial netns.
This change is needed so that we can refine TCP rcvbuf autotuning,
to take RTT into consideration.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
New tracepoint trace_tcp_send_reset is added and called from
tcp_v4_send_reset(), tcp_v6_send_reset() and tcp_send_active_reset().
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Notice that in some cases I placed the "fall through" comment
on its own line, which is what GCC is expecting to find.
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While the cited commit fixed a possible deadlock, it added a leak
of the request socket, since reqsk_put() must be called if the BPF
filter decided the ACK packet must be dropped.
Fixes: d624d276d1 ("tcp: fix possible deadlock in TCP stack vs BPF filter")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Twice patches trying to constify inet{6}_protocol have been reverted:
39294c3df2 ("Revert "ipv6: constify inet6_protocol structures"") to
revert 3a3a4e3054 and then 03157937fe ("Revert "ipv4: make
net_protocol const"") to revert aa8db499ea.
Add a comment that the structures can not be const because the
early_demux field can change based on a sysctl.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When SOF_TIMESTAMPING_RX_SOFTWARE is enabled for tcp sockets, return the
timestamp corresponding to the highest sequence number data returned.
Previously the skb->tstamp is overwritten when a TCP packet is placed
in the out of order queue. While the packet is in the ooo queue, save the
timestamp in the TCB_SKB_CB. This space is shared with the gso_*
options which are only used on the tx path, and a previously unused 4
byte hole.
When skbs are coalesced either in the sk_receive_queue or the
out_of_order_queue always choose the timestamp of the appended skb to
maintain the invariant of returning the timestamp of the last byte in
the recvmsg buffer.
Signed-off-by: Mike Maloney <maloney@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Filtering the ACK packet was not put at the right place.
At this place, we already allocated a child and put it
into accept queue.
We absolutely need to call tcp_child_process() to release
its spinlock, or we will deadlock at accept() or close() time.
Found by syzkaller team (Thanks a lot !)
Fixes: 8fac365f63 ("tcp: Add a tcp_filter hook before handle ack packet")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Chenbo Feng <fengc@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a second device index, sdif, to inet6 socket lookups. sdif is the
index for ingress devices enslaved to an l3mdev. It allows the lookups
to consider the enslaved device as well as the L3 domain when searching
for a socket.
TCP moves the data in the cb. Prior to tcp_v4_rcv (e.g., early demux) the
ingress index is obtained from IPCB using inet_sdif and after tcp_v4_rcv
tcp_v4_sdif is used.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit 3a3a4e3054.
inet6_add_protocol and inet6_del_protocol include casts that remove the
effect of the const annotation on their parameter, leading to possible
runtime crashes.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
prequeue is a tcp receive optimization that moves part of rx processing
from bh to process context.
This only works if the socket being processed belongs to a process that
is blocked in recv on that socket.
In practice, this doesn't happen anymore that often because nowadays
servers tend to use an event driven (epoll) model.
Even normal client applications (web browsers) commonly use many tcp
connections in parallel.
This has measureable impact only in netperf (which uses plain recv and
thus allows prequeue use) from host to locally running vm (~4%), however,
there were no changes when using netperf between two physical hosts with
ixgbe interfaces.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The inet6_protocol structure is only passed as the first argument to
inet6_add_protocol or inet6_del_protocol, both of which are declared as
const. Thus the inet6_protocol structure itself can be const.
Also drop __read_mostly where present on the newly const structures.
Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
The last (4th) argument of tcp_rcv_established() is redundant as it
always equals to skb->len and the skb itself is always passed as 2th
agrument. There is no reason to have it.
Signed-off-by: Ilya V. Matveychikov <matvejchikov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet