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[ Upstream commit e3d5ea2c011ecb16fb94c56a659364e6b30fac94 ]
If recv_actor() returns an incorrect value, tcp_read_sock()
might loop forever.
Instead, issue a one time warning and make sure to make progress.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20220302161723.3910001-2-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e0fecb289ad3fd2245cdc50bf450b97fcca39884 ]
A prior patch increased the size of struct tcp_zerocopy_receive
but did not update do_tcp_getsockopt() handling to properly account
for this.
This patch simply reintroduces content erroneously cut from the
referenced prior patch that handles the new struct size.
Fixes: 18fb76ed5386 ("net-zerocopy: Copy straggler unaligned data for TCP Rx. zerocopy.")
Signed-off-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 70701b83e208767f2720d8cd3e6a62cddafb3a30 ]
TCP Receive zerocopy iterates through the SKB queue via
tcp_recv_skb(), acquiring a pointer to an SKB and an offset within
that SKB to read from. From there, it iterates the SKB frags array to
determine which offset to start remapping pages from.
However, this is built on the assumption that the offset read so far
within the SKB is smaller than the SKB length. If this assumption is
violated, we can attempt to read an invalid frags array element, which
would cause a fault.
tcp_recv_skb() can cause such an SKB to be returned when the TCP FIN
flag is set. Therefore, we must guard against this occurrence inside
skb_advance_frag().
One way that we can reproduce this error follows:
1) In a receiver program, call getsockopt(TCP_ZEROCOPY_RECEIVE) with:
char some_array[32 * 1024];
struct tcp_zerocopy_receive zc = {
.copybuf_address = (__u64) &some_array[0],
.copybuf_len = 32 * 1024,
};
2) In a sender program, after a TCP handshake, send the following
sequence of packets:
i) Seq = [X, X+4000]
ii) Seq = [X+4000, X+5000]
iii) Seq = [X+4000, X+5000], Flags = FIN | URG, urgptr=1000
(This can happen without URG, if we have a signal pending, but URG is
a convenient way to reproduce the behaviour).
In this case, the following event sequence will occur on the receiver:
tcp_zerocopy_receive():
-> receive_fallback_to_copy() // copybuf_len >= inq
-> tcp_recvmsg_locked() // reads 5000 bytes, then breaks due to URG
-> tcp_recv_skb() // yields skb with skb->len == offset
-> tcp_zerocopy_set_hint_for_skb()
-> skb_advance_to_frag() // will returns a frags ptr. >= nr_frags
-> find_next_mappable_frag() // will dereference this bad frags ptr.
With this patch, skb_advance_to_frag() will no longer return an
invalid frags pointer, and will return NULL instead, fixing the issue.
Signed-off-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 05255b823a61 ("tcp: add TCP_ZEROCOPY_RECEIVE support for zerocopy receive")
Link: https://lore.kernel.org/r/20211111235215.2605384-1-arjunroy.kdev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7fba5309efe24e4f0284ef4b8663cdf401035e72 ]
Refactor skb frag fast-forwarding for tcp receive zerocopy. This is
part of a patch set that introduces short-circuited hybrid copies
for small receive operations, which results in roughly 33% fewer
syscalls for small RPC scenarios.
skb_advance_to_frag(), given a skb and an offset into the skb,
iterates from the first frag for the skb until we're at the frag
specified by the offset. Assuming the offset provided refers to how
many bytes in the skb are already read, the returned frag points to
the next frag we may read from, while offset_frag is set to the number
of bytes from this frag that we have already read.
If frag is not null and offset_frag is equal to 0, then we may be able
to map this frag's page into the process address space with
vm_insert_page(). However, if offset_frag is not equal to 0, then we
cannot do so.
Signed-off-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 18fb76ed53865c1b5d5f0157b1b825704590beb5 ]
When TCP receive zerocopy does not successfully map the entire
requested space, it outputs a 'hint' that the caller should recvmsg().
Augment zerocopy to accept a user buffer that it tries to copy this
hint into - if it is possible to copy the entire hint, it will do so.
This elides a recvmsg() call for received traffic that isn't exactly
page-aligned in size.
This was tested with RPC-style traffic of arbitrary sizes. Normally,
each received message required at least one getsockopt() call, and one
recvmsg() call for the remaining unaligned data.
With this change, almost all of the recvmsg() calls are eliminated,
leading to a savings of about 25%-50% in number of system calls
for RPC-style workloads.
Signed-off-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cf12e6f9124629b18a6182deefc0315f0a73a199 ]
v1: Implement a more general statement as recommended by Eric Dumazet. The
sequence number will be advanced, so this check will fix the FIN case and
other cases.
A customer reported sockets stuck in the CLOSING state. A Vmcore revealed that
the write_queue was not empty as determined by tcp_write_queue_empty() but the
sk_buff containing the FIN flag had been freed and the socket was zombied in
that state. Corresponding pcaps show no FIN from the Linux kernel on the wire.
Some instrumentation was added to the kernel and it was found that there is a
timing window where tcp_sendmsg() can run after tcp_send_fin().
tcp_sendmsg() will hit an error, for example:
1269 ▹ if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))↩
1270 ▹ ▹ goto do_error;↩
tcp_remove_empty_skb() will then free the FIN sk_buff as "skb->len == 0". The
TCP socket is now wedged in the FIN-WAIT-1 state because the FIN is never sent.
If the other side sends a FIN packet the socket will transition to CLOSING and
remain that way until the system is rebooted.
Fix this by checking for the FIN flag in the sk_buff and don't free it if that
is the case. Testing confirmed that fixed the issue.
Fixes: fdfc5c8594c2 ("tcp: remove empty skb from write queue in error cases")
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Reported-by: Monir Zouaoui <Monir.Zouaoui@mail.schwarz>
Reported-by: Simon Stier <simon.stier@mail.schwarz>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 19757cebf0c5016a1f36f7fe9810a9f0b33c0832 ]
Use of percpu_counter structure to track count of orphaned
sockets is causing problems on modern hosts with 256 cpus
or more.
Stefan Bach reported a serious spinlock contention in real workloads,
that I was able to reproduce with a netfilter rule dropping
incoming FIN packets.
53.56% server [kernel.kallsyms] [k] queued_spin_lock_slowpath
|
---queued_spin_lock_slowpath
|
--53.51%--_raw_spin_lock_irqsave
|
--53.51%--__percpu_counter_sum
tcp_check_oom
|
|--39.03%--__tcp_close
| tcp_close
| inet_release
| inet6_release
| sock_close
| __fput
| ____fput
| task_work_run
| exit_to_usermode_loop
| do_syscall_64
| entry_SYSCALL_64_after_hwframe
| __GI___libc_close
|
--14.48%--tcp_out_of_resources
tcp_write_timeout
tcp_retransmit_timer
tcp_write_timer_handler
tcp_write_timer
call_timer_fn
expire_timers
__run_timers
run_timer_softirq
__softirqentry_text_start
As explained in commit cf86a086a180 ("net/dst: use a smaller percpu_counter
batch for dst entries accounting"), default batch size is too big
for the default value of tcp_max_orphans (262144).
But even if we reduce batch sizes, there would still be cases
where the estimated count of orphans is beyond the limit,
and where tcp_too_many_orphans() has to call the expensive
percpu_counter_sum_positive().
One solution is to use plain per-cpu counters, and have
a timer to periodically refresh this cache.
Updating this cache every 100ms seems about right, tcp pressure
state is not radically changing over shorter periods.
percpu_counter was nice 15 years ago while hosts had less
than 16 cpus, not anymore by current standards.
v2: Fix the build issue for CONFIG_CRYPTO_DEV_CHELSIO_TLS=m,
reported by kernel test robot <lkp@intel.com>
Remove unused socket argument from tcp_too_many_orphans()
Fixes: dd24c00191d5 ("net: Use a percpu_counter for orphan_count")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Stefan Bach <sfb@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 358ed624207012f03318235017ac6fb41f8af592 upstream.
sk_wmem_schedule makes sure that sk_forward_alloc has enough
bytes for charging that is going to be done by sk_mem_charge.
In the transmit zerocopy path, there is sk_mem_charge but there was
no call to sk_wmem_schedule. This change adds that call.
Without this call to sk_wmem_schedule, sk_forward_alloc can go
negetive which is a bug because sk_forward_alloc is a per-socket
space that has been forward charged so this can't be negative.
Fixes: f214f915e7db ("tcp: enable MSG_ZEROCOPY")
Signed-off-by: Talal Ahmad <talalahmad@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Wei Wang <weiwan@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com>
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>
commit 2107d45f17bedd7dbf4178462da0ac223835a2a7 upstream.
getsockopt(TCP_ZEROCOPY_RECEIVE) has a bug where we read a
user-provided "len" field of type signed int, and then compare the
value to the result of an "offsetofend" operation, which is unsigned.
Negative values provided by the user will be promoted to large
positive numbers; thus checking that len < offsetofend() will return
false when the intention was that it return true.
Note that while len is originally checked for negative values earlier
on in do_tcp_getsockopt(), subsequent calls to get_user() re-read the
value from userspace which may have changed in the meantime.
Therefore, re-add the check for negative values after the call to
get_user in the handler code for TCP_ZEROCOPY_RECEIVE.
Fixes: c8856c051454 ("tcp-zerocopy: Return inq along with tcp receive zerocopy.")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Arjun Roy <arjunroy@google.com>
Link: https://lore.kernel.org/r/20210225232628.4033281-1-arjunroy.kdev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9d9b1ee0b2d1c9e02b2338c4a4b0a062d2d3edac upstream.
The TCP session does not terminate with TCP_USER_TIMEOUT when data
remain untransmitted due to zero window.
The number of unanswered zero-window probes (tcp_probes_out) is
reset to zero with incoming acks irrespective of the window size,
as described in tcp_probe_timer():
RFC 1122 4.2.2.17 requires the sender to stay open indefinitely
as long as the receiver continues to respond probes. We support
this by default and reset icsk_probes_out with incoming ACKs.
This counter, however, is the wrong one to be used in calculating the
duration that the window remains closed and data remain untransmitted.
Thanks to Jonathan Maxwell <jmaxwell37@gmail.com> for diagnosing the
actual issue.
In this patch a new timestamp is introduced for the socket in order to
track the elapsed time for the zero-window probes that have not been
answered with any non-zero window ack.
Fixes: 9721e709fa68 ("tcp: simplify window probe aborting on USER_TIMEOUT")
Reported-by: William McCall <william.mccall@gmail.com>
Co-developed-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Enke Chen <enchen@paloaltonetworks.com>
Reviewed-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20210115223058.GA39267@localhost.localdomain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With SO_RCVLOWAT, under memory pressure,
it is possible to enter a state where:
1. We have not received enough bytes to satisfy SO_RCVLOWAT.
2. We have not entered buffer pressure (see tcp_rmem_pressure()).
3. But, we do not have enough buffer space to accept more packets.
In this case, we advertise 0 rwnd (due to #3) but the application does
not drain the receive queue (no wakeup because of #1 and #2) so the
flow stalls.
Modify the heuristic for SO_RCVLOWAT so that, if we are advertising
rwnd<=rcv_mss, force a wakeup to prevent a stall.
Without this patch, setting tcp_rmem to 6143 and disabling TCP
autotune causes a stalled flow. With this patch, no stall occurs. This
is with RPC-style traffic with large messages.
Fixes: 03f45c883c6f ("tcp: avoid extra wakeups for SO_RCVLOWAT users")
Signed-off-by: Arjun Roy <arjunroy@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20201023184709.217614-1-arjunroy.kdev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Rejecting non-native endian BTF overlapped with the addition
of support for it.
The rest were more simple overlapping changes, except the
renesas ravb binding update, which had to follow a file
move as well as a YAML conversion.
Signed-off-by: David S. Miller <davem@davemloft.net>
commit a10674bf2406 ("tcp: detecting the misuse of .sendpage for Slab
objects") adds the checks for Slab pages, but the pages don't have
page_count are still missing from the check.
Network layer's sendpage method is not designed to send page_count 0
pages neither, therefore both PageSlab() and page_count() should be
both checked for the sending page. This is exactly what sendpage_ok()
does.
This patch uses sendpage_ok() in do_tcp_sendpages() to detect misused
.sendpage, to make the code more robust.
Fixes: a10674bf2406 ("tcp: detecting the misuse of .sendpage for Slab objects")
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Coly Li <colyli@suse.de>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: stable@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
TCP has been using it to work around the possibility of tcp_delack_timer()
finding the socket owned by user.
After commit 6f458dfb4092 ("tcp: improve latencies of timer triggered events")
we added TCP_DELACK_TIMER_DEFERRED atomic bit for more immediate recovery,
so we can get rid of icsk_ack.blocked
This frees space that following patch will reuse.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Alexei Starovoitov says:
====================
pull-request: bpf-next 2020-09-23
The following pull-request contains BPF updates for your *net-next* tree.
We've added 95 non-merge commits during the last 22 day(s) which contain
a total of 124 files changed, 4211 insertions(+), 2040 deletions(-).
The main changes are:
1) Full multi function support in libbpf, from Andrii.
2) Refactoring of function argument checks, from Lorenz.
3) Make bpf_tail_call compatible with functions (subprograms), from Maciej.
4) Program metadata support, from YiFei.
5) bpf iterator optimizations, from Yonghong.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
For EPOLLET, applications must call sendmsg until they get EAGAIN.
Otherwise, there is no guarantee that EPOLLOUT is sent if there was
a failure upon memory allocation.
As a result on high-speed NICs, userspace observes multiple small
sendmsgs after a partial sendmsg until EAGAIN, since TCP can send
1-2 TSOs in between two sendmsg syscalls:
// One large partial send due to memory allocation failure.
sendmsg(20MB) = 2MB
// Many small sends until EAGAIN.
sendmsg(18MB) = 64KB
sendmsg(17.9MB) = 128KB
sendmsg(17.8MB) = 64KB
...
sendmsg(...) = EAGAIN
// At this point, userspace can assume an EPOLLOUT.
To fix this, set the SOCK_NOSPACE on all partial sendmsg scenarios
to guarantee that we send EPOLLOUT after partial sendmsg.
After this commit userspace can assume that it will receive an EPOLLOUT
after the first partial sendmsg. This EPOLLOUT will benefit from
sk_stream_write_space() logic delaying the EPOLLOUT until significant
space is available in write queue.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If there was any event available on the TCP socket, tcp_poll()
will be called to retrieve all the events. In tcp_poll(), we call
sk_stream_is_writeable() which returns true as long as we are at least
one byte below notsent_lowat. This will result in quite a few
spurious EPLLOUT and frequent tiny sendmsg() calls as a result.
Similar to sk_stream_write_space(), use __sk_stream_is_writeable
with a wake value of 1, so that we set EPOLLOUT only if half the
space is available for write.
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
That is needed to let the subflows announce promptly when new
space is available in the receive buffer.
tcp_cleanup_rbuf() is currently a static function, drop the
scope modifier and add a declaration in the TCP header.
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that the previous patches ensure that all call sites for
tcp_set_congestion_control() want to initialize congestion control, we
can simplify tcp_set_congestion_control() by removing the reinit
argument and the code to support it.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Kevin Yang <yyd@google.com>
Cc: Lawrence Brakmo <brakmo@fb.com>
Change tcp_init_transfer() to only initialize congestion control if it
has not been initialized already.
With this new approach, we can arrange things so that if the EBPF code
sets the congestion control by calling setsockopt(TCP_CONGESTION) then
tcp_init_transfer() will not re-initialize the CC module.
This is an approach that has the following beneficial properties:
(1) This allows CC module customizations made by the EBPF called in
tcp_init_transfer() to persist, and not be wiped out by a later
call to tcp_init_congestion_control() in tcp_init_transfer().
(2) Does not flip the order of EBPF and CC init, to avoid causing bugs
for existing code upstream that depends on the current order.
(3) Does not cause 2 initializations for for CC in the case where the
EBPF called in tcp_init_transfer() wants to set the CC to a new CC
algorithm.
(4) Allows follow-on simplifications to the code in net/core/filter.c
and net/ipv4/tcp_cong.c, which currently both have some complexity
to special-case CC initialization to avoid double CC
initialization if EBPF sets the CC.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Kevin Yang <yyd@google.com>
Cc: Lawrence Brakmo <brakmo@fb.com>
This patch is adapted from Eric's patch in an earlier discussion [1].
The TCP_SAVE_SYN currently only stores the network header and
tcp header. This patch allows it to optionally store
the mac header also if the setsockopt's optval is 2.
It requires one more bit for the "save_syn" bit field in tcp_sock.
This patch achieves this by moving the syn_smc bit next to the is_mptcp.
The syn_smc is currently used with the TCP experimental option. Since
syn_smc is only used when CONFIG_SMC is enabled, this patch also puts
the "IS_ENABLED(CONFIG_SMC)" around it like the is_mptcp did
with "IS_ENABLED(CONFIG_MPTCP)".
The mac_hdrlen is also stored in the "struct saved_syn"
to allow a quick offset from the bpf prog if it chooses to start
getting from the network header or the tcp header.
[1]: https://lore.kernel.org/netdev/CANn89iLJNWh6bkH7DNhy_kmcAexuUCccqERqe7z2QsvPhGrYPQ@mail.gmail.com/
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/bpf/20200820190123.2886935-1-kafai@fb.com
This patch adds bpf_setsockopt(TCP_BPF_RTO_MIN) to allow bpf prog
to set the min rto of a connection. It could be used together
with the earlier patch which has added bpf_setsockopt(TCP_BPF_DELACK_MAX).
A later selftest patch will communicate the max delay ack in a
bpf tcp header option and then the receiving side can use
bpf_setsockopt(TCP_BPF_RTO_MIN) to set a shorter rto.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200820190027.2884170-1-kafai@fb.com
This change is mostly from an internal patch and adapts it from sysctl
config to the bpf_setsockopt setup.
The bpf_prog can set the max delay ack by using
bpf_setsockopt(TCP_BPF_DELACK_MAX). This max delay ack can be communicated
to its peer through bpf header option. The receiving peer can then use
this max delay ack and set a potentially lower rto by using
bpf_setsockopt(TCP_BPF_RTO_MIN) which will be introduced
in the next patch.
Another later selftest patch will also use it like the above to show
how to write and parse bpf tcp header option.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200820190021.2884000-1-kafai@fb.com
The TCP_SAVE_SYN has both the network header and tcp header.
The total length of the saved syn packet is currently stored in
the first 4 bytes (u32) of an array and the actual packet data is
stored after that.
A later patch will add a bpf helper that allows to get the tcp header
alone from the saved syn without the network header. It will be more
convenient to have a direct offset to a specific header instead of
re-parsing it. This requires to separately store the network hdrlen.
The total header length (i.e. network + tcp) is still needed for the
current usage in getsockopt. Although this total length can be obtained
by looking into the tcphdr and then get the (th->doff << 2), this patch
chooses to directly store the tcp hdrlen in the second four bytes of
this newly created "struct saved_syn". By using a new struct, it can
give a readable name to each individual header length.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200820190014.2883694-1-kafai@fb.com
When TFO keys are read back on big endian systems either via the global
sysctl interface or via getsockopt() using TCP_FASTOPEN_KEY, the values
don't match what was written.
For example, on s390x:
# echo "1-2-3-4" > /proc/sys/net/ipv4/tcp_fastopen_key
# cat /proc/sys/net/ipv4/tcp_fastopen_key
02000000-01000000-04000000-03000000
Instead of:
# cat /proc/sys/net/ipv4/tcp_fastopen_key
00000001-00000002-00000003-00000004
Fix this by converting to the correct endianness on read. This was
reported by Colin Ian King when running the 'tcp_fastopen_backup_key' net
selftest on s390x, which depends on the read value matching what was
written. I've confirmed that the test now passes on big and little endian
systems.
Signed-off-by: Jason Baron <jbaron@akamai.com>
Fixes: 438ac88009bc ("net: fastopen: robustness and endianness fixes for SipHash")
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Eric Dumazet <edumazet@google.com>
Reported-and-tested-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change adds TCP_NLA_EDT to SCM_TIMESTAMPING_OPT_STATS that reports
the earliest departure time(EDT) of the timestamped skb. By tracking EDT
values of the skb from different timestamps, we can observe when and how
much the value changed. This allows to measure the precise delay
injected on the sender host e.g. by a bpf-base throttler.
Signed-off-by: Yousuk Seung <ysseung@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sockptr_advance never properly worked. Replace it with _offset variants
of copy_from_sockptr and copy_to_sockptr.
Fixes: ba423fdaa589 ("net: add a new sockptr_t type")
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reported-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rework the remaining setsockopt code to pass a sockptr_t instead of a
plain user pointer. This removes the last remaining set_fs(KERNEL_DS)
outside of architecture specific code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> [ieee802154]
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Handle the few cases that need special treatment in-line using
in_compat_syscall(). This also removes all the now unused
compat_{get,set}sockopt methods.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This essentially reverts commit 721230326891 ("tcp: md5: reject TCP_MD5SIG
or TCP_MD5SIG_EXT on established sockets")
Mathieu reported that many vendors BGP implementations can
actually switch TCP MD5 on established flows.
Quoting Mathieu :
Here is a list of a few network vendors along with their behavior
with respect to TCP MD5:
- Cisco: Allows for password to be changed, but within the hold-down
timer (~180 seconds).
- Juniper: When password is initially set on active connection it will
reset, but after that any subsequent password changes no network
resets.
- Nokia: No notes on if they flap the tcp connection or not.
- Ericsson/RedBack: Allows for 2 password (old/new) to co-exist until
both sides are ok with new passwords.
- Meta-Switch: Expects the password to be set before a connection is
attempted, but no further info on whether they reset the TCP
connection on a change.
- Avaya: Disable the neighbor, then set password, then re-enable.
- Zebos: Would normally allow the change when socket connected.
We can revert my prior change because commit 9424e2e7ad93 ("tcp: md5: fix potential
overestimation of TCP option space") removed the leak of 4 kernel bytes to
the wire that was the main reason for my patch.
While doing my investigations, I found a bug when a MD5 key is changed, leading
to these commits that stable teams want to consider before backporting this revert :
Commit 6a2febec338d ("tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()")
Commit e6ced831ef11 ("tcp: md5: refine tcp_md5_do_add()/tcp_md5_hash_key() barriers")
Fixes: 721230326891 "tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets"
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
My prior fix went a bit too far, according to Herbert and Mathieu.
Since we accept that concurrent TCP MD5 lookups might see inconsistent
keys, we can use READ_ONCE()/WRITE_ONCE() instead of smp_rmb()/smp_wmb()
Clearing all key->key[] is needed to avoid possible KMSAN reports,
if key->keylen is increased. Since tcp_md5_do_add() is not fast path,
using __GFP_ZERO to clear all struct tcp_md5sig_key is simpler.
data_race() was added in linux-5.8 and will prevent KCSAN reports,
this can safely be removed in stable backports, if data_race() is
not yet backported.
v2: use data_race() both in tcp_md5_hash_key() and tcp_md5_do_add()
Fixes: 6a2febec338d ("tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Marco Elver <elver@google.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
MD5 keys are read with RCU protection, and tcp_md5_do_add()
might update in-place a prior key.
Normally, typical RCU updates would allocate a new piece
of memory. In this case only key->key and key->keylen might
be updated, and we do not care if an incoming packet could
see the old key, the new one, or some intermediate value,
since changing the key on a live flow is known to be problematic
anyway.
We only want to make sure that in the case key->keylen
is changed, cpus in tcp_md5_hash_key() wont try to use
uninitialized data, or crash because key->keylen was
read twice to feed sg_init_one() and ahash_request_set_crypt()
Fixes: 9ea88a153001 ("tcp: md5: check md5 signature without socket lock")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) Fix cfg80211 deadlock, from Johannes Berg.
2) RXRPC fails to send norigications, from David Howells.
3) MPTCP RM_ADDR parsing has an off by one pointer error, fix from
Geliang Tang.
4) Fix crash when using MSG_PEEK with sockmap, from Anny Hu.
5) The ucc_geth driver needs __netdev_watchdog_up exported, from
Valentin Longchamp.
6) Fix hashtable memory leak in dccp, from Wang Hai.
7) Fix how nexthops are marked as FDB nexthops, from David Ahern.
8) Fix mptcp races between shutdown and recvmsg, from Paolo Abeni.
9) Fix crashes in tipc_disc_rcv(), from Tuong Lien.
10) Fix link speed reporting in iavf driver, from Brett Creeley.
11) When a channel is used for XSK and then reused again later for XSK,
we forget to clear out the relevant data structures in mlx5 which
causes all kinds of problems. Fix from Maxim Mikityanskiy.
12) Fix memory leak in genetlink, from Cong Wang.
13) Disallow sockmap attachments to UDP sockets, it simply won't work.
From Lorenz Bauer.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (83 commits)
net: ethernet: ti: ale: fix allmulti for nu type ale
net: ethernet: ti: am65-cpsw-nuss: fix ale parameters init
net: atm: Remove the error message according to the atomic context
bpf: Undo internal BPF_PROBE_MEM in BPF insns dump
libbpf: Support pre-initializing .bss global variables
tools/bpftool: Fix skeleton codegen
bpf: Fix memlock accounting for sock_hash
bpf: sockmap: Don't attach programs to UDP sockets
bpf: tcp: Recv() should return 0 when the peer socket is closed
ibmvnic: Flush existing work items before device removal
genetlink: clean up family attributes allocations
net: ipa: header pad field only valid for AP->modem endpoint
net: ipa: program upper nibbles of sequencer type
net: ipa: fix modem LAN RX endpoint id
net: ipa: program metadata mask differently
ionic: add pcie_print_link_status
rxrpc: Fix race between incoming ACK parser and retransmitter
net/mlx5: E-Switch, Fix some error pointer dereferences
net/mlx5: Don't fail driver on failure to create debugfs
net/mlx5e: CT: Fix ipv6 nat header rewrite actions
...
Use vm_insert_pages() for tcp receive zerocopy. Spin lock cycles (as
reported by perf) drop from a couple of percentage points to a fraction of
a percent. This results in a roughly 6% increase in efficiency, measured
roughly as zerocopy receive count divided by CPU utilization.
The intention of this patchset is to reduce atomic ops for tcp zerocopy
receives, which normally hits the same spinlock multiple times
consecutively.
[akpm@linux-foundation.org: suppress gcc-7.2.0 warning]
Link: http://lkml.kernel.org/r/20200128025958.43490-3-arjunroy.kdev@gmail.com
Signed-off-by: Arjun Roy <arjunroy@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Cc: David Miller <davem@davemloft.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_KEEPCNT sockopt from kernel space
without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_KEEPINTVL sockopt from kernel space
without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_KEEP_IDLE sockopt from kernel
space without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_USER_TIMEOUT sockopt from kernel
space without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_SYNCNT sockopt from kernel space
without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_QUICKACK sockopt from kernel space
without going through a fake uaccess. Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_NODELAY sockopt from kernel space
without going through a fake uaccess. Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper to directly set the TCP_CORK sockopt from kernel space
without going through a fake uaccess. Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
