From patchwork Wed Mar 9 09:05:09 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: 12774847 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 52591C433F5 for ; Wed, 9 Mar 2022 09:05:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231765AbiCIJGN (ORCPT ); Wed, 9 Mar 2022 04:06:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36126 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231739AbiCIJGL (ORCPT ); Wed, 9 Mar 2022 04:06:11 -0500 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2726C16BCC1 for ; Wed, 9 Mar 2022 01:05:13 -0800 (PST) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 2298Pb6H017411 for ; Wed, 9 Mar 2022 01:05:13 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : content-type : content-transfer-encoding : mime-version; s=facebook; bh=Jkb0WnMSoZHBo/dvQJTwSL5k62C3Sas1WgGkzfhYHJk=; b=NxIXuZUi8Ib3z0Ky34/1BjRtKmRd22BNphInieba1MkmM9HhumkHlDoy32oH2osbNBua 0huhCBemIXY9lveXLzk6UaJGU/ccgs714imhLiK3YG+SYk8OtcY0+BtzqmGKNSML5+LB RxWm6InIkQfTUoRcv09d4bktDORLKlpRluI= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3ep52tqre4-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 09 Mar 2022 01:05:12 -0800 Received: from twshared27297.14.frc2.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:11d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Wed, 9 Mar 2022 01:05:11 -0800 Received: by devbig933.frc1.facebook.com (Postfix, from userid 6611) id 427BA1ADC5F2; Wed, 9 Mar 2022 01:05:09 -0800 (PST) From: Martin KaFai Lau To: CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , , Subject: [PATCH bpf-next 4/5] bpf: Remove BPF_SKB_DELIVERY_TIME_NONE and rename s/delivery_time_/tstamp_/ Date: Wed, 9 Mar 2022 01:05:09 -0800 Message-ID: <20220309090509.3712315-1-kafai@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220309090444.3710464-1-kafai@fb.com> References: <20220309090444.3710464-1-kafai@fb.com> X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: 4v3cmlhjC0BEJg-Mjw4JhCE2g5whJxRg X-Proofpoint-GUID: 4v3cmlhjC0BEJg-Mjw4JhCE2g5whJxRg X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.816,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-03-09_04,2022-03-04_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This patch is to simplify the uapi bpf.h regarding to the tstamp type and use a similar way as the kernel to describe the value stored in __sk_buff->tstamp. My earlier thought was to avoid describing the semantic and clock base for the rcv timestamp until there is more clarity on the use case, so the __sk_buff->delivery_time_type naming instead of __sk_buff->tstamp_type. With some thoughts, it can reuse the UNSPEC naming. This patch first removes BPF_SKB_DELIVERY_TIME_NONE and also rename BPF_SKB_DELIVERY_TIME_UNSPEC to BPF_SKB_TSTAMP_UNSPEC and BPF_SKB_DELIVERY_TIME_MONO to BPF_SKB_TSTAMP_DELIVERY_MONO. The semantic of BPF_SKB_TSTAMP_DELIVERY_MONO is the same: __sk_buff->tstamp has delivery time in mono clock base. BPF_SKB_TSTAMP_UNSPEC means __sk_buff->tstamp has the (rcv) tstamp at ingress and the delivery time at egress. At egress, the clock base could be found from skb->sk->sk_clockid. __sk_buff->tstamp == 0 naturally means NONE, so NONE is not needed. With BPF_SKB_TSTAMP_UNSPEC for the rcv tstamp at ingress, the __sk_buff->delivery_time_type is also renamed to __sk_buff->tstamp_type which was also suggested in the earlier discussion: https://lore.kernel.org/bpf/b181acbe-caf8-502d-4b7b-7d96b9fc5d55@iogearbox.net/ The above will then make __sk_buff->tstamp and __sk_buff->tstamp_type the same as its kernel skb->tstamp and skb->mono_delivery_time counter part. The internal kernel function bpf_skb_convert_dtime_type_read() is then renamed to bpf_skb_convert_tstamp_type_read() and it can be simplified with the BPF_SKB_DELIVERY_TIME_NONE gone. A BPF_ALU32_IMM(BPF_AND) insn is also saved by using BPF_JMP32_IMM(BPF_JSET). The bpf helper bpf_skb_set_delivery_time() is also renamed to bpf_skb_set_tstamp(). The arg name is changed from dtime to tstamp also. It only allows setting tstamp 0 for BPF_SKB_TSTAMP_UNSPEC and it could be relaxed later if there is use case to change mono delivery time to non mono. prog->delivery_time_access is also renamed to prog->tstamp_type_access. Signed-off-by: Martin KaFai Lau --- include/linux/filter.h | 2 +- include/uapi/linux/bpf.h | 40 ++++++++-------- net/core/filter.c | 88 +++++++++++++--------------------- tools/include/uapi/linux/bpf.h | 40 ++++++++-------- 4 files changed, 77 insertions(+), 93 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 9bf26307247f..05ed9bd31b45 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -573,7 +573,7 @@ struct bpf_prog { enforce_expected_attach_type:1, /* Enforce expected_attach_type checking at attach time */ call_get_stack:1, /* Do we call bpf_get_stack() or bpf_get_stackid() */ call_get_func_ip:1, /* Do we call get_func_ip() */ - delivery_time_access:1; /* Accessed __sk_buff->delivery_time_type */ + tstamp_type_access:1; /* Accessed __sk_buff->tstamp_type */ enum bpf_prog_type type; /* Type of BPF program */ enum bpf_attach_type expected_attach_type; /* For some prog types */ u32 len; /* Number of filter blocks */ diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 4eebea830613..65871bdbb9c8 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5087,23 +5087,22 @@ union bpf_attr { * 0 on success, or a negative error in case of failure. On error * *dst* buffer is zeroed out. * - * long bpf_skb_set_delivery_time(struct sk_buff *skb, u64 dtime, u32 dtime_type) + * long bpf_skb_set_tstamp(struct sk_buff *skb, u64 tstamp, u32 tstamp_type) * Description - * Set a *dtime* (delivery time) to the __sk_buff->tstamp and also - * change the __sk_buff->delivery_time_type to *dtime_type*. + * Change the __sk_buff->tstamp_type to *tstamp_type* + * and set *tstamp* to the __sk_buff->tstamp together. * - * When setting a delivery time (non zero *dtime*) to - * __sk_buff->tstamp, only BPF_SKB_DELIVERY_TIME_MONO *dtime_type* - * is supported. It is the only delivery_time_type that will be - * kept after bpf_redirect_*(). - * - * If there is no need to change the __sk_buff->delivery_time_type, - * the delivery time can be directly written to __sk_buff->tstamp + * If there is no need to change the __sk_buff->tstamp_type, + * the tstamp value can be directly written to __sk_buff->tstamp * instead. * - * *dtime* 0 and *dtime_type* BPF_SKB_DELIVERY_TIME_NONE - * can be used to clear any delivery time stored in - * __sk_buff->tstamp. + * BPF_SKB_TSTAMP_DELIVERY_MONO is the only tstamp that + * will be kept during bpf_redirect_*(). A non zero + * *tstamp* must be used with the BPF_SKB_TSTAMP_DELIVERY_MONO + * *tstamp_type*. + * + * A BPF_SKB_TSTAMP_UNSPEC *tstamp_type* can only be used + * with a zero *tstamp*. * * Only IPv4 and IPv6 skb->protocol are supported. * @@ -5116,7 +5115,7 @@ union bpf_attr { * Return * 0 on success. * **-EINVAL** for invalid input - * **-EOPNOTSUPP** for unsupported delivery_time_type and protocol + * **-EOPNOTSUPP** for unsupported protocol */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5311,7 +5310,7 @@ union bpf_attr { FN(xdp_load_bytes), \ FN(xdp_store_bytes), \ FN(copy_from_user_task), \ - FN(skb_set_delivery_time), \ + FN(skb_set_tstamp), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper @@ -5502,9 +5501,12 @@ union { \ } __attribute__((aligned(8))) enum { - BPF_SKB_DELIVERY_TIME_NONE, - BPF_SKB_DELIVERY_TIME_UNSPEC, - BPF_SKB_DELIVERY_TIME_MONO, + BPF_SKB_TSTAMP_UNSPEC, + BPF_SKB_TSTAMP_DELIVERY_MONO, /* tstamp has mono delivery time */ + /* For any BPF_SKB_TSTAMP_* that the bpf prog cannot handle, + * the bpf prog should handle it like BPF_SKB_TSTAMP_UNSPEC + * and try to deduce it by ingress, egress or skb->sk->sk_clockid. + */ }; /* user accessible mirror of in-kernel sk_buff. @@ -5547,7 +5549,7 @@ struct __sk_buff { __u32 gso_segs; __bpf_md_ptr(struct bpf_sock *, sk); __u32 gso_size; - __u8 delivery_time_type; + __u8 tstamp_type; __u32 :24; /* Padding, future use. */ __u64 hwtstamp; }; diff --git a/net/core/filter.c b/net/core/filter.c index f914e4b13b18..03655f2074ae 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -7388,36 +7388,36 @@ static const struct bpf_func_proto bpf_sock_ops_reserve_hdr_opt_proto = { .arg3_type = ARG_ANYTHING, }; -BPF_CALL_3(bpf_skb_set_delivery_time, struct sk_buff *, skb, - u64, dtime, u32, dtime_type) +BPF_CALL_3(bpf_skb_set_tstamp, struct sk_buff *, skb, + u64, tstamp, u32, tstamp_type) { /* skb_clear_delivery_time() is done for inet protocol */ if (skb->protocol != htons(ETH_P_IP) && skb->protocol != htons(ETH_P_IPV6)) return -EOPNOTSUPP; - switch (dtime_type) { - case BPF_SKB_DELIVERY_TIME_MONO: - if (!dtime) + switch (tstamp_type) { + case BPF_SKB_TSTAMP_DELIVERY_MONO: + if (!tstamp) return -EINVAL; - skb->tstamp = dtime; + skb->tstamp = tstamp; skb->mono_delivery_time = 1; break; - case BPF_SKB_DELIVERY_TIME_NONE: - if (dtime) + case BPF_SKB_TSTAMP_UNSPEC: + if (tstamp) return -EINVAL; skb->tstamp = 0; skb->mono_delivery_time = 0; break; default: - return -EOPNOTSUPP; + return -EINVAL; } return 0; } -static const struct bpf_func_proto bpf_skb_set_delivery_time_proto = { - .func = bpf_skb_set_delivery_time, +static const struct bpf_func_proto bpf_skb_set_tstamp_proto = { + .func = bpf_skb_set_tstamp, .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_PTR_TO_CTX, @@ -7786,8 +7786,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_tcp_gen_syncookie_proto; case BPF_FUNC_sk_assign: return &bpf_sk_assign_proto; - case BPF_FUNC_skb_set_delivery_time: - return &bpf_skb_set_delivery_time_proto; + case BPF_FUNC_skb_set_tstamp: + return &bpf_skb_set_tstamp_proto; #endif default: return bpf_sk_base_func_proto(func_id); @@ -8127,9 +8127,9 @@ static bool bpf_skb_is_valid_access(int off, int size, enum bpf_access_type type return false; info->reg_type = PTR_TO_SOCK_COMMON_OR_NULL; break; - case offsetof(struct __sk_buff, delivery_time_type): + case offsetof(struct __sk_buff, tstamp_type): return false; - case offsetofend(struct __sk_buff, delivery_time_type) ... offsetof(struct __sk_buff, hwtstamp) - 1: + case offsetofend(struct __sk_buff, tstamp_type) ... offsetof(struct __sk_buff, hwtstamp) - 1: /* Explicitly prohibit access to padding in __sk_buff. */ return false; default: @@ -8484,14 +8484,14 @@ static bool tc_cls_act_is_valid_access(int off, int size, break; case bpf_ctx_range_till(struct __sk_buff, family, local_port): return false; - case offsetof(struct __sk_buff, delivery_time_type): + case offsetof(struct __sk_buff, tstamp_type): /* The convert_ctx_access() on reading and writing * __sk_buff->tstamp depends on whether the bpf prog - * has used __sk_buff->delivery_time_type or not. - * Thus, we need to set prog->delivery_time_access + * has used __sk_buff->tstamp_type or not. + * Thus, we need to set prog->tstamp_type_access * earlier during is_valid_access() here. */ - ((struct bpf_prog *)prog)->delivery_time_access = 1; + ((struct bpf_prog *)prog)->tstamp_type_access = 1; return size == sizeof(__u8); } @@ -8888,42 +8888,22 @@ static u32 flow_dissector_convert_ctx_access(enum bpf_access_type type, return insn - insn_buf; } -static struct bpf_insn *bpf_convert_dtime_type_read(const struct bpf_insn *si, - struct bpf_insn *insn) +static struct bpf_insn *bpf_convert_tstamp_type_read(const struct bpf_insn *si, + struct bpf_insn *insn) { __u8 value_reg = si->dst_reg; __u8 skb_reg = si->src_reg; + /* AX is needed because src_reg and dst_reg could be the same */ __u8 tmp_reg = BPF_REG_AX; *insn++ = BPF_LDX_MEM(BPF_B, tmp_reg, skb_reg, PKT_VLAN_PRESENT_OFFSET); - *insn++ = BPF_ALU32_IMM(BPF_AND, tmp_reg, - SKB_MONO_DELIVERY_TIME_MASK); - *insn++ = BPF_JMP32_IMM(BPF_JEQ, tmp_reg, 0, 2); - /* value_reg = BPF_SKB_DELIVERY_TIME_MONO */ - *insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_DELIVERY_TIME_MONO); - *insn++ = BPF_JMP_A(IS_ENABLED(CONFIG_NET_CLS_ACT) ? 10 : 5); - - *insn++ = BPF_LDX_MEM(BPF_DW, tmp_reg, skb_reg, - offsetof(struct sk_buff, tstamp)); - *insn++ = BPF_JMP_IMM(BPF_JNE, tmp_reg, 0, 2); - /* value_reg = BPF_SKB_DELIVERY_TIME_NONE */ - *insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_DELIVERY_TIME_NONE); - *insn++ = BPF_JMP_A(IS_ENABLED(CONFIG_NET_CLS_ACT) ? 6 : 1); - -#ifdef CONFIG_NET_CLS_ACT - *insn++ = BPF_LDX_MEM(BPF_B, tmp_reg, skb_reg, PKT_VLAN_PRESENT_OFFSET); - *insn++ = BPF_ALU32_IMM(BPF_AND, tmp_reg, TC_AT_INGRESS_MASK); - *insn++ = BPF_JMP32_IMM(BPF_JEQ, tmp_reg, 0, 2); - /* At ingress, value_reg = 0 */ - *insn++ = BPF_MOV32_IMM(value_reg, 0); + *insn++ = BPF_JMP32_IMM(BPF_JSET, tmp_reg, + SKB_MONO_DELIVERY_TIME_MASK, 2); + *insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_TSTAMP_UNSPEC); *insn++ = BPF_JMP_A(1); -#endif - - /* value_reg = BPF_SKB_DELIVERYT_TIME_UNSPEC */ - *insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_DELIVERY_TIME_UNSPEC); + *insn++ = BPF_MOV32_IMM(value_reg, BPF_SKB_TSTAMP_DELIVERY_MONO); - /* 15 insns with CONFIG_NET_CLS_ACT */ return insn; } @@ -8956,11 +8936,11 @@ static struct bpf_insn *bpf_convert_tstamp_read(const struct bpf_prog *prog, __u8 skb_reg = si->src_reg; #ifdef CONFIG_NET_CLS_ACT - /* If the delivery_time_type is read, + /* If the tstamp_type is read, * the bpf prog is aware the tstamp could have delivery time. - * Thus, read skb->tstamp as is if delivery_time_access is true. + * Thus, read skb->tstamp as is if tstamp_type_access is true. */ - if (!prog->delivery_time_access) { + if (!prog->tstamp_type_access) { /* AX is needed because src_reg and dst_reg could be the same */ __u8 tmp_reg = BPF_REG_AX; @@ -8990,13 +8970,13 @@ static struct bpf_insn *bpf_convert_tstamp_write(const struct bpf_prog *prog, __u8 skb_reg = si->dst_reg; #ifdef CONFIG_NET_CLS_ACT - /* If the delivery_time_type is read, + /* If the tstamp_type is read, * the bpf prog is aware the tstamp could have delivery time. - * Thus, write skb->tstamp as is if delivery_time_access is true. + * Thus, write skb->tstamp as is if tstamp_type_access is true. * Otherwise, writing at ingress will have to clear the * mono_delivery_time bit also. */ - if (!prog->delivery_time_access) { + if (!prog->tstamp_type_access) { __u8 tmp_reg = BPF_REG_AX; *insn++ = BPF_LDX_MEM(BPF_B, tmp_reg, skb_reg, PKT_VLAN_PRESENT_OFFSET); @@ -9329,8 +9309,8 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type, insn = bpf_convert_tstamp_read(prog, si, insn); break; - case offsetof(struct __sk_buff, delivery_time_type): - insn = bpf_convert_dtime_type_read(si, insn); + case offsetof(struct __sk_buff, tstamp_type): + insn = bpf_convert_tstamp_type_read(si, insn); break; case offsetof(struct __sk_buff, gso_segs): diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 4eebea830613..65871bdbb9c8 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5087,23 +5087,22 @@ union bpf_attr { * 0 on success, or a negative error in case of failure. On error * *dst* buffer is zeroed out. * - * long bpf_skb_set_delivery_time(struct sk_buff *skb, u64 dtime, u32 dtime_type) + * long bpf_skb_set_tstamp(struct sk_buff *skb, u64 tstamp, u32 tstamp_type) * Description - * Set a *dtime* (delivery time) to the __sk_buff->tstamp and also - * change the __sk_buff->delivery_time_type to *dtime_type*. + * Change the __sk_buff->tstamp_type to *tstamp_type* + * and set *tstamp* to the __sk_buff->tstamp together. * - * When setting a delivery time (non zero *dtime*) to - * __sk_buff->tstamp, only BPF_SKB_DELIVERY_TIME_MONO *dtime_type* - * is supported. It is the only delivery_time_type that will be - * kept after bpf_redirect_*(). - * - * If there is no need to change the __sk_buff->delivery_time_type, - * the delivery time can be directly written to __sk_buff->tstamp + * If there is no need to change the __sk_buff->tstamp_type, + * the tstamp value can be directly written to __sk_buff->tstamp * instead. * - * *dtime* 0 and *dtime_type* BPF_SKB_DELIVERY_TIME_NONE - * can be used to clear any delivery time stored in - * __sk_buff->tstamp. + * BPF_SKB_TSTAMP_DELIVERY_MONO is the only tstamp that + * will be kept during bpf_redirect_*(). A non zero + * *tstamp* must be used with the BPF_SKB_TSTAMP_DELIVERY_MONO + * *tstamp_type*. + * + * A BPF_SKB_TSTAMP_UNSPEC *tstamp_type* can only be used + * with a zero *tstamp*. * * Only IPv4 and IPv6 skb->protocol are supported. * @@ -5116,7 +5115,7 @@ union bpf_attr { * Return * 0 on success. * **-EINVAL** for invalid input - * **-EOPNOTSUPP** for unsupported delivery_time_type and protocol + * **-EOPNOTSUPP** for unsupported protocol */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5311,7 +5310,7 @@ union bpf_attr { FN(xdp_load_bytes), \ FN(xdp_store_bytes), \ FN(copy_from_user_task), \ - FN(skb_set_delivery_time), \ + FN(skb_set_tstamp), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper @@ -5502,9 +5501,12 @@ union { \ } __attribute__((aligned(8))) enum { - BPF_SKB_DELIVERY_TIME_NONE, - BPF_SKB_DELIVERY_TIME_UNSPEC, - BPF_SKB_DELIVERY_TIME_MONO, + BPF_SKB_TSTAMP_UNSPEC, + BPF_SKB_TSTAMP_DELIVERY_MONO, /* tstamp has mono delivery time */ + /* For any BPF_SKB_TSTAMP_* that the bpf prog cannot handle, + * the bpf prog should handle it like BPF_SKB_TSTAMP_UNSPEC + * and try to deduce it by ingress, egress or skb->sk->sk_clockid. + */ }; /* user accessible mirror of in-kernel sk_buff. @@ -5547,7 +5549,7 @@ struct __sk_buff { __u32 gso_segs; __bpf_md_ptr(struct bpf_sock *, sk); __u32 gso_size; - __u8 delivery_time_type; + __u8 tstamp_type; __u32 :24; /* Padding, future use. */ __u64 hwtstamp; };