From: Jakub Sitnicki <jakub@cloudflare.com>
To: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, kernel-team@cloudflare.com,
Eric Dumazet <edumazet@google.com>,
John Fastabend <john.fastabend@gmail.com>,
Lorenz Bauer <lmb@cloudflare.com>,
Martin KaFai Lau <kafai@fb.com>
Subject: [PATCH bpf-next v2 00/11] Extend SOCKMAP to store listening sockets
Date: Fri, 10 Jan 2020 11:50:16 +0100 [thread overview]
Message-ID: <20200110105027.257877-1-jakub@cloudflare.com> (raw)
With the realization that properly cloning listening sockets that have
psock state/callbacks is tricky, comes the second version of patches.
The spirit of the patch set stays the same - make SOCKMAP a generic
collection for listening and established sockets. This would let us use the
SOCKMAP with reuseport today, and in the future hopefully with BPF programs
that run at socket lookup time [0]. For a bit more context, please see v1
cover letter [1].
The biggest change that happened since v1 is how we deal with clearing
psock state in a copy of parent socket when cloning it (patches 3 & 4).
As much as I did not want to touch icsk/tcp clone path, it seems
unavoidable. The changes were kept down to a minimum, with attention to not
break existing users. That said, a review from the TCP maintainer would be
invaluable (patches 3 & 4).
Patches 1 & 2 will conflict with recently posted "Fixes for sockmap/tls
from more complex BPF progs" series [0]. I'll adapt or split them out this
series once sockmap/tls fixes from John land in bpf-next branch.
Some food for thought - is mixing listening and established sockets in the
same BPF map a good idea? I don't know but I couldn't find a good reason to
restrict the user.
Considering how much the code evolved, I didn't carry over Acks from v1.
Thanks,
jkbs
[0] https://lore.kernel.org/bpf/157851776348.1732.12600714815781177085.stgit@ubuntu3-kvm2/T/#t
[1] https://lore.kernel.org/bpf/20191123110751.6729-1-jakub@cloudflare.com/
v1 -> v2:
- af_ops->syn_recv_sock callback is no longer overridden and burdened with
restoring sk_prot and clearing sk_user_data in the child socket. As child
socket is already hashed when syn_recv_sock returns, it is too late to
put it in the right state. Instead patches 3 & 4 restore sk_prot and
clear sk_user_data before we hash the child socket. (Pointed out by
Martin Lau)
- Annotate shared access to sk->sk_prot with READ_ONCE/WRITE_ONCE macros as
we write to it from sk_msg while socket might be getting cloned on
another CPU. (Suggested by John Fastabend)
- Convert tests for SOCKMAP holding listening sockets to return-on-error
style, and hook them up to test_progs. Also use BPF skeleton for setup.
Add new tests to cover the race scenario discovered during v1 review.
RFC -> v1:
- Switch from overriding proto->accept to af_ops->syn_recv_sock, which
happens earlier. Clearing the psock state after accept() does not work
for child sockets that become orphaned (never got accepted). v4-mapped
sockets need special care.
- Return the socket cookie on SOCKMAP lookup from syscall to be on par with
REUSEPORT_SOCKARRAY. Requires SOCKMAP to take u64 on lookup/update from
syscall.
- Make bpf_sk_redirect_map (ingress) and bpf_msg_redirect_map (egress)
SOCKMAP helpers fail when target socket is a listening one.
- Make bpf_sk_select_reuseport helper fail when target is a TCP established
socket.
- Teach libbpf to recognize SK_REUSEPORT program type from section name.
- Add a dedicated set of tests for SOCKMAP holding listening sockets,
covering map operations, overridden socket callbacks, and BPF helpers.
Jakub Sitnicki (11):
bpf, sk_msg: Don't reset saved sock proto on restore
net, sk_msg: Annotate lockless access to sk_prot on clone
net, sk_msg: Clear sk_user_data pointer on clone if tagged
tcp_bpf: Don't let child socket inherit parent protocol ops on copy
bpf, sockmap: Allow inserting listening TCP sockets into sockmap
bpf, sockmap: Don't set up sockmap progs for listening sockets
bpf, sockmap: Return socket cookie on lookup from syscall
bpf, sockmap: Let all kernel-land lookup values in SOCKMAP
bpf: Allow selecting reuseport socket from a SOCKMAP
selftests/bpf: Extend SK_REUSEPORT tests to cover SOCKMAP
selftests/bpf: Tests for SOCKMAP holding listening sockets
include/linux/skmsg.h | 14 +-
include/net/sock.h | 37 +-
include/net/tcp.h | 1 +
kernel/bpf/verifier.c | 6 +-
net/core/filter.c | 15 +-
net/core/skmsg.c | 2 +-
net/core/sock.c | 11 +-
net/core/sock_map.c | 120 +-
net/ipv4/tcp_bpf.c | 19 +-
net/ipv4/tcp_minisocks.c | 2 +
net/ipv4/tcp_ulp.c | 2 +-
net/tls/tls_main.c | 2 +-
.../bpf/prog_tests/select_reuseport.c | 60 +-
.../selftests/bpf/prog_tests/sockmap_listen.c | 1378 +++++++++++++++++
.../selftests/bpf/progs/test_sockmap_listen.c | 76 +
tools/testing/selftests/bpf/test_maps.c | 6 +-
16 files changed, 1696 insertions(+), 55 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/sockmap_listen.c
create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_listen.c
--
2.24.1
next reply other threads:[~2020-01-10 10:50 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-10 10:50 Jakub Sitnicki [this message]
2020-01-10 10:50 ` [PATCH bpf-next v2 01/11] bpf, sk_msg: Don't reset saved sock proto on restore Jakub Sitnicki
2020-01-11 22:50 ` John Fastabend
2020-01-10 10:50 ` [PATCH bpf-next v2 02/11] net, sk_msg: Annotate lockless access to sk_prot on clone Jakub Sitnicki
2020-01-11 23:14 ` John Fastabend
2020-01-13 15:09 ` Jakub Sitnicki
2020-01-14 3:14 ` John Fastabend
2020-01-20 17:00 ` John Fastabend
2020-01-20 18:11 ` Jakub Sitnicki
2020-01-21 12:42 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 03/11] net, sk_msg: Clear sk_user_data pointer on clone if tagged Jakub Sitnicki
2020-01-11 23:38 ` John Fastabend
2020-01-12 12:55 ` kbuild test robot
2020-01-13 20:15 ` Martin Lau
2020-01-14 16:04 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 04/11] tcp_bpf: Don't let child socket inherit parent protocol ops on copy Jakub Sitnicki
2020-01-11 2:42 ` kbuild test robot
2020-01-11 3:02 ` kbuild test robot
2020-01-11 23:48 ` John Fastabend
2020-01-13 22:31 ` Jakub Sitnicki
2020-01-13 22:23 ` Martin Lau
2020-01-13 22:42 ` Jakub Sitnicki
2020-01-13 23:23 ` Martin Lau
2020-01-10 10:50 ` [PATCH bpf-next v2 05/11] bpf, sockmap: Allow inserting listening TCP sockets into sockmap Jakub Sitnicki
2020-01-11 23:59 ` John Fastabend
2020-01-13 15:48 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 06/11] bpf, sockmap: Don't set up sockmap progs for listening sockets Jakub Sitnicki
2020-01-12 0:51 ` John Fastabend
2020-01-12 1:07 ` John Fastabend
2020-01-13 17:59 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 07/11] bpf, sockmap: Return socket cookie on lookup from syscall Jakub Sitnicki
2020-01-12 0:56 ` John Fastabend
2020-01-13 23:12 ` Martin Lau
2020-01-14 3:16 ` John Fastabend
2020-01-14 15:48 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 08/11] bpf, sockmap: Let all kernel-land lookup values in SOCKMAP Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 09/11] bpf: Allow selecting reuseport socket from a SOCKMAP Jakub Sitnicki
2020-01-12 1:00 ` John Fastabend
2020-01-13 23:45 ` Martin Lau
2020-01-15 12:41 ` Jakub Sitnicki
2020-01-13 23:51 ` Martin Lau
2020-01-15 12:57 ` Jakub Sitnicki
2020-01-10 10:50 ` [PATCH bpf-next v2 10/11] selftests/bpf: Extend SK_REUSEPORT tests to cover SOCKMAP Jakub Sitnicki
2020-01-12 1:01 ` John Fastabend
2020-01-10 10:50 ` [PATCH bpf-next v2 11/11] selftests/bpf: Tests for SOCKMAP holding listening sockets Jakub Sitnicki
2020-01-12 1:06 ` John Fastabend
2020-01-13 15:58 ` Jakub Sitnicki
2020-01-11 0:18 ` [PATCH bpf-next v2 00/11] Extend SOCKMAP to store " Alexei Starovoitov
2020-01-11 22:47 ` John Fastabend
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