From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-185.mta0.migadu.com (out-185.mta0.migadu.com [91.218.175.185]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 631DC4430 for ; Wed, 16 Oct 2024 00:10:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.185 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729037409; cv=none; b=K6cVRC7mwwG/jvbwhUtiAkswDQkCo69Ll1uLGuRk2pmetXUhl/XEfMHmiiW8kRzvci/cFb8jd0Byo5YTgjJTDNkzxnz+QOoHw/W9IbW5Fn3yv59AxBh5qdprhJ1tyknqjtr1A37R9An5+L0OXW3G2//rm0WyU2XmPB7OFtnhNjs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729037409; c=relaxed/simple; bh=p3bZseUDVA/nDqe1n2tXXoOhsEQBXev8IiHrPGGG05E=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=swqunCIyhBP1YG/XfYhM8SnOVgjgcXn3fV5Lj4iTfEpk9oCVoFKzPusiP9Wi68t3bQxQKaEoXJqLy9O+fTtXx4V4T7uDEeUsa7N3OAtIKJFl6fcxLgqGiJbt3lQgKIXpxu4IkoZ9KfAEAu4hoAv0kZbar98wm/EdM5wKpQOMSlo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=okK7cxd+; arc=none smtp.client-ip=91.218.175.185 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="okK7cxd+" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1729037405; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RzvOFbzdSfD6Z9mVAB7PkbmqAiWN+492BN4iUDdHU9A=; b=okK7cxd+vFjlgzPmhm1/ZuN26yx5A49IRNvX9wwM6PO1z1hdk1hA3hZNbXTto0k9jrdlrZ unPJG/hmuaKkljdZ7n+PoKIYd4UJKrkDHJex7jRziZxu3ScFK+JiU+cBe01ormP65KtVAX y3DgBnML1XAFep4UeKvciyWz+1gzsj0= Date: Tue, 15 Oct 2024 17:09:57 -0700 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH net-next v2 04/12] net-timestamp: add static key to control the whole bpf extension To: Jason Xing Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, willemdebruijn.kernel@gmail.com, willemb@google.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, bpf@vger.kernel.org, netdev@vger.kernel.org, Jason Xing References: <20241012040651.95616-1-kerneljasonxing@gmail.com> <20241012040651.95616-5-kerneljasonxing@gmail.com> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Martin KaFai Lau In-Reply-To: <20241012040651.95616-5-kerneljasonxing@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 10/11/24 9:06 PM, Jason Xing wrote: > From: Jason Xing > > Willem suggested that we use a static key to control. The advantage > is that we will not affect the existing applications at all if we > don't load BPF program. > > In this patch, except the static key, I also add one logic that is > used to test if the socket has enabled its tsflags in order to > support bpf logic to allow both cases to happen at the same time. > Or else, the skb carring related timestamp flag doesn't know which > way of printing is desirable. > > One thing important is this patch allows print from both applications > and bpf program at the same time. Now we have three kinds of print: > 1) only BPF program prints > 2) only application program prints > 3) both can print without side effect > > Signed-off-by: Jason Xing > --- > include/net/sock.h | 1 + > net/core/filter.c | 3 +++ > net/core/skbuff.c | 38 ++++++++++++++++++++++++++++++++++++++ > 3 files changed, 42 insertions(+) > > diff --git a/include/net/sock.h b/include/net/sock.h > index 66ecd78f1dfe..b7c51b95c92d 100644 > --- a/include/net/sock.h > +++ b/include/net/sock.h > @@ -2889,6 +2889,7 @@ static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif) > void sock_def_readable(struct sock *sk); > > int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk); > +DECLARE_STATIC_KEY_FALSE(bpf_tstamp_control); > void sock_set_timestamp(struct sock *sk, int optname, bool valbool); > int sock_get_timestamping(struct so_timestamping *timestamping, > sockptr_t optval, unsigned int optlen); > diff --git a/net/core/filter.c b/net/core/filter.c > index 996426095bd9..08135f538c99 100644 > --- a/net/core/filter.c > +++ b/net/core/filter.c > @@ -5204,6 +5204,8 @@ static const struct bpf_func_proto bpf_get_socket_uid_proto = { > .arg1_type = ARG_PTR_TO_CTX, > }; > > +DEFINE_STATIC_KEY_FALSE(bpf_tstamp_control); > + > static int bpf_sock_set_timestamping(struct sock *sk, > struct so_timestamping *timestamping) > { > @@ -5217,6 +5219,7 @@ static int bpf_sock_set_timestamping(struct sock *sk, > return -EINVAL; > > WRITE_ONCE(sk->sk_tsflags[BPFPROG_TS_REQUESTOR], flags); > + static_branch_enable(&bpf_tstamp_control); Not sure when is a good time to do static_branch_disable(). The bpf prog may be detached also. (IF) it ends up staying with the cgroup/sockops interface, it should depend on the existing static key in cgroup_bpf_enabled(CGROUP_SOCK_OPS) instead of adding another one. > > return 0; > } > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index f36eb9daa31a..d0f912f1ff7b 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -5540,6 +5540,29 @@ void skb_complete_tx_timestamp(struct sk_buff *skb, > } > EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp); > > +static bool sk_tstamp_tx_flags(struct sock *sk, u32 tsflags, int tstype) sk is unused. > +{ > + u32 testflag; > + > + switch (tstype) { > + case SCM_TSTAMP_SCHED: Instead of doing this translation, is it easier to directly store the bpf prog desired ts"type" (i.e. the SCM_TSTAMP_*) in the sk->sk_tsflags_bpf? or there is a specific need to keep the SOF_TIMESTAMPING_* value in sk->sk_tsflags_bpf? > + testflag = SOF_TIMESTAMPING_TX_SCHED; > + break; > + case SCM_TSTAMP_SND: > + testflag = SOF_TIMESTAMPING_TX_SOFTWARE; > + break; > + case SCM_TSTAMP_ACK: > + testflag = SOF_TIMESTAMPING_TX_ACK; > + break; > + default: > + return false; > + } > + if (tsflags & testflag) > + return true; > + > + return false; > +} > + > static void skb_tstamp_tx_output(struct sk_buff *orig_skb, > const struct sk_buff *ack_skb, > struct skb_shared_hwtstamps *hwtstamps, > @@ -5558,6 +5581,9 @@ static void skb_tstamp_tx_output(struct sk_buff *orig_skb, > if (!skb_may_tx_timestamp(sk, tsonly)) > return; > > + if (!sk_tstamp_tx_flags(sk, tsflags, tstype)) This is a new test. tsflags is the sk->sk_tsflags here if I read it correctly. My understanding is the sendmsg can provide SOF_TIMESTAMPING_* for individual skb. Would it break? Is it the similar case on the skb tx_flags that Willem has mentioned in the patch 0's thread? > + return; > + > if (tsonly) { > #ifdef CONFIG_INET > if ((tsflags & SOF_TIMESTAMPING_OPT_STATS) && > @@ -5593,6 +5619,15 @@ static void skb_tstamp_tx_output(struct sk_buff *orig_skb, > __skb_complete_tx_timestamp(skb, sk, tstype, opt_stats); > } > > +static void bpf_skb_tstamp_tx_output(struct sock *sk, int tstype) > +{ > + u32 tsflags; > + > + tsflags = READ_ONCE(sk->sk_tsflags[BPFPROG_TS_REQUESTOR]); > + if (!sk_tstamp_tx_flags(sk, tsflags, tstype)) > + return; > +} > + > void __skb_tstamp_tx(struct sk_buff *orig_skb, > const struct sk_buff *ack_skb, > struct skb_shared_hwtstamps *hwtstamps, > @@ -5601,6 +5636,9 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb, > if (!sk) > return; > > + if (static_branch_unlikely(&bpf_tstamp_control)) > + bpf_skb_tstamp_tx_output(sk, tstype); > + > skb_tstamp_tx_output(orig_skb, ack_skb, hwtstamps, sk, tstype); > } > EXPORT_SYMBOL_GPL(__skb_tstamp_tx);