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From: Florent Revest <revest@chromium.org>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	kpsingh@chromium.org, revest@google.com, jackmanb@chromium.org,
	linux-kernel@vger.kernel.org,
	Florent Revest <revest@chromium.org>,
	KP Singh <kpsingh@kernel.org>
Subject: [PATCH bpf-next v7 1/5] bpf: Be less specific about socket cookies guarantees
Date: Wed, 10 Feb 2021 12:14:02 +0100
Message-ID: <20210210111406.785541-1-revest@chromium.org> (raw)

Since "92acdc58ab11 bpf, net: Rework cookie generator as per-cpu one"
socket cookies are not guaranteed to be non-decreasing. The
bpf_get_socket_cookie helper descriptions are currently specifying that
cookies are non-decreasing but we don't want users to rely on that.

Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Florent Revest <revest@chromium.org>
Acked-by: KP Singh <kpsingh@kernel.org>
---
 include/uapi/linux/bpf.h       | 8 ++++----
 tools/include/uapi/linux/bpf.h | 8 ++++----
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index c001766adcbc..0b735c2729b2 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1656,22 +1656,22 @@ union bpf_attr {
  * 		networking traffic statistics as it provides a global socket
  * 		identifier that can be assumed unique.
  * 	Return
- * 		A 8-byte long non-decreasing number on success, or 0 if the
- * 		socket field is missing inside *skb*.
+ * 		A 8-byte long unique number on success, or 0 if the socket
+ * 		field is missing inside *skb*.
  *
  * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
  * 	Description
  * 		Equivalent to bpf_get_socket_cookie() helper that accepts
  * 		*skb*, but gets socket from **struct bpf_sock_addr** context.
  * 	Return
- * 		A 8-byte long non-decreasing number.
+ * 		A 8-byte long unique number.
  *
  * u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx)
  * 	Description
  * 		Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
  * 		*skb*, but gets socket from **struct bpf_sock_ops** context.
  * 	Return
- * 		A 8-byte long non-decreasing number.
+ * 		A 8-byte long unique number.
  *
  * u32 bpf_get_socket_uid(struct sk_buff *skb)
  * 	Return
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index c001766adcbc..0b735c2729b2 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1656,22 +1656,22 @@ union bpf_attr {
  * 		networking traffic statistics as it provides a global socket
  * 		identifier that can be assumed unique.
  * 	Return
- * 		A 8-byte long non-decreasing number on success, or 0 if the
- * 		socket field is missing inside *skb*.
+ * 		A 8-byte long unique number on success, or 0 if the socket
+ * 		field is missing inside *skb*.
  *
  * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
  * 	Description
  * 		Equivalent to bpf_get_socket_cookie() helper that accepts
  * 		*skb*, but gets socket from **struct bpf_sock_addr** context.
  * 	Return
- * 		A 8-byte long non-decreasing number.
+ * 		A 8-byte long unique number.
  *
  * u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx)
  * 	Description
  * 		Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
  * 		*skb*, but gets socket from **struct bpf_sock_ops** context.
  * 	Return
- * 		A 8-byte long non-decreasing number.
+ * 		A 8-byte long unique number.
  *
  * u32 bpf_get_socket_uid(struct sk_buff *skb)
  * 	Return
-- 
2.30.0.478.g8a0d178c01-goog


             reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-10 11:14 Florent Revest [this message]
2021-02-10 11:14 ` [PATCH bpf-next v7 2/5] bpf: Expose bpf_get_socket_cookie to tracing programs Florent Revest
2021-02-10 19:51   ` Andrii Nakryiko
2021-02-10 19:55     ` Florent Revest
2021-02-12  2:28   ` Alexei Starovoitov
2021-02-10 11:14 ` [PATCH bpf-next v7 3/5] selftests/bpf: Integrate the socket_cookie test to test_progs Florent Revest
2021-02-10 11:14 ` [PATCH bpf-next v7 4/5] selftests/bpf: Use vmlinux.h in socket_cookie_prog.c Florent Revest
2021-02-10 11:14 ` [PATCH bpf-next v7 5/5] selftests/bpf: Add a selftest for the tracing bpf_get_socket_cookie Florent Revest
2021-02-12  2:20 ` [PATCH bpf-next v7 1/5] bpf: Be less specific about socket cookies guarantees patchwork-bot+netdevbpf

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