From: Kuniyuki Iwashima <kuniyu@amazon.com>
To: Eric Dumazet <edumazet@google.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Paolo Abeni <pabeni@redhat.com>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>,
Kuniyuki Iwashima <kuni1840@gmail.com>, <bpf@vger.kernel.org>,
<netdev@vger.kernel.org>
Subject: [PATCH v7 bpf-next 3/6] bpf: tcp: Handle BPF SYN Cookie in skb_steal_sock().
Date: Thu, 21 Dec 2023 10:28:03 +0900 [thread overview]
Message-ID: <20231221012806.37137-4-kuniyu@amazon.com> (raw)
In-Reply-To: <20231221012806.37137-1-kuniyu@amazon.com>
We will support arbitrary SYN Cookie with BPF.
If BPF prog validates ACK and kfunc allocates a reqsk, it will
be carried to TCP stack as skb->sk with req->syncookie 1. Also,
the reqsk has its listener as req->rsk_listener with no refcnt
taken.
When the TCP stack looks up a socket from the skb, we steal
inet_reqsk(skb->sk)->rsk_listener in skb_steal_sock() so that
the skb will be processed in cookie_v[46]_check() with the
listener.
Note that we do not clear skb->sk and skb->destructor so that we
can carry the reqsk to cookie_v[46]_check().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
include/net/request_sock.h | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/include/net/request_sock.h b/include/net/request_sock.h
index 26c630c40abb..8839133d6f6b 100644
--- a/include/net/request_sock.h
+++ b/include/net/request_sock.h
@@ -101,10 +101,21 @@ static inline struct sock *skb_steal_sock(struct sk_buff *skb,
}
*prefetched = skb_sk_is_prefetched(skb);
- if (*prefetched)
+ if (*prefetched) {
+#if IS_ENABLED(CONFIG_SYN_COOKIES)
+ if (sk->sk_state == TCP_NEW_SYN_RECV && inet_reqsk(sk)->syncookie) {
+ struct request_sock *req = inet_reqsk(sk);
+
+ *refcounted = false;
+ sk = req->rsk_listener;
+ req->rsk_listener = NULL;
+ return sk;
+ }
+#endif
*refcounted = sk_is_refcounted(sk);
- else
+ } else {
*refcounted = true;
+ }
skb->destructor = NULL;
skb->sk = NULL;
--
2.30.2
next prev parent reply other threads:[~2023-12-21 1:29 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-21 1:28 [PATCH v7 bpf-next 0/6] bpf: tcp: Support arbitrary SYN Cookie at TC Kuniyuki Iwashima
2023-12-21 1:28 ` [PATCH v7 bpf-next 1/6] tcp: Move tcp_ns_to_ts() to tcp.h Kuniyuki Iwashima
2023-12-21 1:28 ` [PATCH v7 bpf-next 2/6] tcp: Move skb_steal_sock() to request_sock.h Kuniyuki Iwashima
2023-12-21 1:28 ` Kuniyuki Iwashima [this message]
2023-12-21 1:28 ` [PATCH v7 bpf-next 4/6] bpf: tcp: Handle BPF SYN Cookie in cookie_v[46]_check() Kuniyuki Iwashima
2023-12-21 1:28 ` [PATCH v7 bpf-next 5/6] bpf: tcp: Support arbitrary SYN Cookie Kuniyuki Iwashima
2024-01-12 1:44 ` Martin KaFai Lau
2024-01-15 20:13 ` Kuniyuki Iwashima
2023-12-21 1:28 ` [PATCH v7 bpf-next 6/6] selftest: bpf: Test bpf_sk_assign_tcp_reqsk() Kuniyuki Iwashima
2023-12-21 6:35 ` Martin KaFai Lau
2023-12-21 7:04 ` Kuniyuki Iwashima
2023-12-21 8:43 ` Kuniyuki Iwashima
2024-01-02 19:17 ` Yonghong Song
2023-12-21 16:44 ` Matthieu Baerts
2024-01-12 6:20 ` [PATCH v7 bpf-next 0/6] bpf: tcp: Support arbitrary SYN Cookie at TC Martin KaFai Lau
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231221012806.37137-4-kuniyu@amazon.com \
--to=kuniyu@amazon.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=edumazet@google.com \
--cc=kuni1840@gmail.com \
--cc=martin.lau@linux.dev \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).