From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-173.mta0.migadu.com (out-173.mta0.migadu.com [91.218.175.173]) (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 7E4B8189B84 for ; Mon, 7 Apr 2025 22:30:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744065015; cv=none; b=Mddu9sQ0SOH18Aw9upl+C2XPFMfJkNbICNSB9Sz4EY3RRD3WdlZYpXY14ZQ8xVxlHZlieymG14IuB2k5V2LV59D3swlFxNNtYhhoyjgIVm+rWK6fnOwQVDiaiEpPRyBoNs6dlc0DnnsUiRaRQwQMh1TkHCFTbB5u7230GsqvBNQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744065015; c=relaxed/simple; bh=VT5e2QPJpXKPCyt+xyHhkKuDO/O11DKdFu/Gm0y60i8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=bTeMGfFf5VQbL6YuSNly9GXWFnxHFFYm8Mcu8yVDsl7cNpoe6At/aLgoL+lnNTSvv6tZ+Q1j9ccYWxy1JdqN9UJLL78eCMdb+Dnrhw0QUSTiD/Gq4edEN840u8r0/l3JnjNuYZGyWmu7XFeipWqtGFN/ySCgTr4xOlJ9GoVDk1o= 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=ZjQcfVvQ; arc=none smtp.client-ip=91.218.175.173 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="ZjQcfVvQ" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1744065011; 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=1yvXU5VmWeqiR0pVuAEpxZIKJoqNCtLLKDriulf8zQ8=; b=ZjQcfVvQKYGxrfUAMfNwzHXmYQ6RCmx/NFE+B7cq67P0q/LGw1Wd8xTkUCSxKUYRpTxXld 85utElGLAoEcSGxmFLZ1ieGEePJNEHqKAfSTNh3FYwpreN0e4DHa6JydwRlPbq98rI5xFt /nr+38u12DjTy7RGq1sjZElYGI1yGaA= Date: Mon, 7 Apr 2025 15:30:06 -0700 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH 3/3] [RFC] Bluetooth: enable bpf TX timestamping To: Pauli Virtanen Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, linux-bluetooth@vger.kernel.org, willemdebruijn.kernel@gmail.com, kerneljasonxing@gmail.com References: <3546b79d-a09b-4971-abd7-ce18696a9536@linux.dev> 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: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 4/2/25 9:56 AM, Pauli Virtanen wrote: > Hi, > > ti, 2025-04-01 kello 18:34 -0700, Martin KaFai Lau kirjoitti: >> On 3/30/25 5:23 AM, Pauli Virtanen wrote: >>> Emit timestamps also for BPF timestamping. >>> >>> *** >>> >>> The tskey management here is not quite right: see cover letter. >>> --- >>> include/net/bluetooth/bluetooth.h | 1 + >>> net/bluetooth/hci_conn.c | 21 +++++++++++++++++++-- >>> 2 files changed, 20 insertions(+), 2 deletions(-) >>> >>> diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h >>> index bbefde319f95..3b2e59cedd2d 100644 >>> --- a/include/net/bluetooth/bluetooth.h >>> +++ b/include/net/bluetooth/bluetooth.h >>> @@ -383,6 +383,7 @@ struct bt_sock { >>> struct list_head accept_q; >>> struct sock *parent; >>> unsigned long flags; >>> + atomic_t bpf_tskey; >>> void (*skb_msg_name)(struct sk_buff *, void *, int *); >>> void (*skb_put_cmsg)(struct sk_buff *, struct msghdr *, struct sock *); >>> }; >>> diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c >>> index 95972fd4c784..7430df1c5822 100644 >>> --- a/net/bluetooth/hci_conn.c >>> +++ b/net/bluetooth/hci_conn.c >>> @@ -28,6 +28,7 @@ >>> #include >>> #include >>> #include >>> +#include >>> >>> #include >>> #include >>> @@ -3072,6 +3073,7 @@ void hci_setup_tx_timestamp(struct sk_buff *skb, size_t key_offset, >>> const struct sockcm_cookie *sockc) >>> { >>> struct sock *sk = skb ? skb->sk : NULL; >>> + bool have_tskey = false; >>> >>> /* This shall be called on a single skb of those generated by user >>> * sendmsg(), and only when the sendmsg() does not return error to >>> @@ -3096,6 +3098,20 @@ void hci_setup_tx_timestamp(struct sk_buff *skb, size_t key_offset, >>> >>> skb_shinfo(skb)->tskey = key - 1; >>> } >>> + have_tskey = true; >>> + } >>> + >>> + if (cgroup_bpf_enabled(CGROUP_SOCK_OPS) && >>> + SK_BPF_CB_FLAG_TEST(sk, SK_BPF_CB_TX_TIMESTAMPING)) { >>> + struct bt_sock *bt_sk = container_of(sk, struct bt_sock, sk); >>> + int key = atomic_inc_return(&bt_sk->bpf_tskey); >> >> I don't think it needs to add "atomic_t bpf_tskey". Allow the bpf to decide what >> the skb_shinfo(skb)->tskey should be if it is not set by the userspace. The idea was that the bpf prog can directly set the skb_shinfo(skb)->tskey if it is not used by the userspace. iirc, it is where the discussion left at during the earlier UDP support thread. > Ok. So if I understand correctly, the plan is that for UDP and > Bluetooth seqpacket sockets it works like this: > > bpf_sock_ops_enable_tx_tstamp() does not set tskey. The bpf_sock_ops_enable_tx_tstamp() has an used "u64 flags" argument. Potentially, it can use the higher 32bits to specify the tskey. > > Socket timestamping sets tskey the same way as previously. > > So when both are in play, it shall work like: > > * attach BPF timestamping > * setsockopt(SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_OPT_ID) > * sendmsg() CMSG SO_TIMESTAMPING = 0 > => tskey 0 (unset) > * sendmsg() CMSG SO_TIMESTAMPING = SOF_TIMESTAMPING_TX_SOFTWARE > => tskey 0 > * sendmsg() CMSG SO_TIMESTAMPING = SOF_TIMESTAMPING_TX_SOFTWARE > => tskey 1 > * sendmsg() CMSG SO_TIMESTAMPING = 0 > => tskey 0 (unset) > * sendmsg() CMSG SO_TIMESTAMPING = 0 > => tskey 0 (unset) > * sendmsg() CMSG SO_TIMESTAMPING = 0 > => tskey 0 (unset) > * sendmsg() CMSG SO_TIMESTAMPING = SOF_TIMESTAMPING_TX_SOFTWARE > => tskey 2 > > and BPF program has to handle the (unset) cases itself. > >> >>> + >>> + if (!have_tskey) >>> + skb_shinfo(skb)->tskey = key - 1; >>> + >>> + bpf_skops_tx_timestamping(sk, skb, >>> + BPF_SOCK_OPS_TSTAMP_SENDMSG_CB); >>> + >>> } >>> } >>> >> >> >