From patchwork Mon Nov 7 23:04:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin KaFai Lau X-Patchwork-Id: 13035420 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C9F3C43219 for ; Mon, 7 Nov 2022 23:04:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232841AbiKGXEc (ORCPT ); Mon, 7 Nov 2022 18:04:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232830AbiKGXEa (ORCPT ); Mon, 7 Nov 2022 18:04:30 -0500 Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 804D125C5A; Mon, 7 Nov 2022 15:04:29 -0800 (PST) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1667862268; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=z9d5E8cFGQW2JMKOQlKfEy4HjJCwGUnDk0RP9tD6S5Q=; b=kIBmDGPbNg0XfirwQ8ttdHP4zBFbUkkYZL2cp7fiPm/lPzRqcTF7fArZa4zlHBiidfplle HYyur5bsnr8qUEoVkxbekorDPFioSxo+0u7R4CtQnS2Nz9OfPfUmyOtc/dZJm5qY5m8f0k YUWBjb65NLNfCOlzoK6RbbnyhnEqF8Q= From: Martin KaFai Lau To: bpf@vger.kernel.org Cc: 'Alexei Starovoitov ' , 'Andrii Nakryiko ' , 'Daniel Borkmann ' , netdev@vger.kernel.org, kernel-team@meta.com Subject: [PATCH v2 bpf-next 1/3] bpf: Add hwtstamp field for the sockops prog Date: Mon, 7 Nov 2022 15:04:18 -0800 Message-Id: <20221107230420.4192307-2-martin.lau@linux.dev> In-Reply-To: <20221107230420.4192307-1-martin.lau@linux.dev> References: <20221107230420.4192307-1-martin.lau@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Martin KaFai Lau The bpf-tc prog has already been able to access the skb_hwtstamps(skb)->hwtstamp. This patch extends the same hwtstamp access to the sockops prog. In sockops, the skb is also available to the bpf prog during the BPF_SOCK_OPS_PARSE_HDR_OPT_CB event. There is a use case that the hwtstamp will be useful to the sockops prog to better measure the one-way-delay when the sender has put the tx timestamp in the tcp header option. Signed-off-by: Martin KaFai Lau --- include/uapi/linux/bpf.h | 1 + net/core/filter.c | 39 +++++++++++++++++++++++++++------- tools/include/uapi/linux/bpf.h | 1 + 3 files changed, 33 insertions(+), 8 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 94659f6b3395..fb4c911d2a03 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -6445,6 +6445,7 @@ struct bpf_sock_ops { * the outgoing header has not * been written yet. */ + __u64 skb_hwtstamp; }; /* Definitions for bpf_sock_ops_cb_flags */ diff --git a/net/core/filter.c b/net/core/filter.c index cb3b635e35be..cd667cdbdb26 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -8925,6 +8925,10 @@ static bool sock_ops_is_valid_access(int off, int size, bpf_ctx_record_field_size(info, size_default); return bpf_ctx_narrow_access_ok(off, size, size_default); + case offsetof(struct bpf_sock_ops, skb_hwtstamp): + if (size != sizeof(__u64)) + return false; + break; default: if (size != size_default) return false; @@ -9108,21 +9112,21 @@ static struct bpf_insn *bpf_convert_tstamp_type_read(const struct bpf_insn *si, return insn; } -static struct bpf_insn *bpf_convert_shinfo_access(const struct bpf_insn *si, +static struct bpf_insn *bpf_convert_shinfo_access(__u8 dst_reg, __u8 skb_reg, struct bpf_insn *insn) { /* si->dst_reg = skb_shinfo(SKB); */ #ifdef NET_SKBUFF_DATA_USES_OFFSET *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, end), - BPF_REG_AX, si->src_reg, + BPF_REG_AX, skb_reg, offsetof(struct sk_buff, end)); *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, head), - si->dst_reg, si->src_reg, + dst_reg, skb_reg, offsetof(struct sk_buff, head)); - *insn++ = BPF_ALU64_REG(BPF_ADD, si->dst_reg, BPF_REG_AX); + *insn++ = BPF_ALU64_REG(BPF_ADD, dst_reg, BPF_REG_AX); #else *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, end), - si->dst_reg, si->src_reg, + dst_reg, skb_reg, offsetof(struct sk_buff, end)); #endif @@ -9515,7 +9519,7 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type, break; case offsetof(struct __sk_buff, gso_segs): - insn = bpf_convert_shinfo_access(si, insn); + insn = bpf_convert_shinfo_access(si->dst_reg, si->src_reg, insn); *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct skb_shared_info, gso_segs), si->dst_reg, si->dst_reg, bpf_target_off(struct skb_shared_info, @@ -9523,7 +9527,7 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type, target_size)); break; case offsetof(struct __sk_buff, gso_size): - insn = bpf_convert_shinfo_access(si, insn); + insn = bpf_convert_shinfo_access(si->dst_reg, si->src_reg, insn); *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct skb_shared_info, gso_size), si->dst_reg, si->dst_reg, bpf_target_off(struct skb_shared_info, @@ -9550,7 +9554,7 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type, BUILD_BUG_ON(sizeof_field(struct skb_shared_hwtstamps, hwtstamp) != 8); BUILD_BUG_ON(offsetof(struct skb_shared_hwtstamps, hwtstamp) != 0); - insn = bpf_convert_shinfo_access(si, insn); + insn = bpf_convert_shinfo_access(si->dst_reg, si->src_reg, insn); *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, bpf_target_off(struct skb_shared_info, @@ -10400,6 +10404,25 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, tcp_flags), si->dst_reg, si->dst_reg, off); break; + case offsetof(struct bpf_sock_ops, skb_hwtstamp): { + struct bpf_insn *jmp_on_null_skb; + + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sock_ops_kern, + skb), + si->dst_reg, si->src_reg, + offsetof(struct bpf_sock_ops_kern, + skb)); + /* Reserve one insn to test skb == NULL */ + jmp_on_null_skb = insn++; + insn = bpf_convert_shinfo_access(si->dst_reg, si->dst_reg, insn); + *insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg, + bpf_target_off(struct skb_shared_info, + hwtstamps, 8, + target_size)); + *jmp_on_null_skb = BPF_JMP_IMM(BPF_JEQ, si->dst_reg, 0, + insn - jmp_on_null_skb - 1); + break; + } } return insn - insn_buf; } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 94659f6b3395..fb4c911d2a03 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -6445,6 +6445,7 @@ struct bpf_sock_ops { * the outgoing header has not * been written yet. */ + __u64 skb_hwtstamp; }; /* Definitions for bpf_sock_ops_cb_flags */