From patchwork Sun Sep 11 08:46:07 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shmulik Ladkani X-Patchwork-Id: 12972788 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 018D5ECAAA1 for ; Sun, 11 Sep 2022 08:46:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229952AbiIKIqg (ORCPT ); Sun, 11 Sep 2022 04:46:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229947AbiIKIqf (ORCPT ); Sun, 11 Sep 2022 04:46:35 -0400 Received: from mail-ej1-x631.google.com (mail-ej1-x631.google.com [IPv6:2a00:1450:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6269D326FC for ; Sun, 11 Sep 2022 01:46:34 -0700 (PDT) Received: by mail-ej1-x631.google.com with SMTP id go34so13679940ejc.2 for ; Sun, 11 Sep 2022 01:46:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=metanetworks.com; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date; bh=cFumHqq0pLb6AlXpm3FchEhhiFTYVLSEGo+Z3jKzfGY=; b=eekVlLfCLAKr7KAH680LfD+MaG7H7witq3vAK19/h4gqycLB3euaKQEWpusKzMcTZq UXSOF+9GDuY65yflcrI5ZiLOD+f0Txm9hcL/9gRB1MdNlPTKSRUrNG7hUNckWwBGg+V5 FgG/qJzzRMbDn/eMFdXw5h+gHmgpXHaWEPg5k= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=cFumHqq0pLb6AlXpm3FchEhhiFTYVLSEGo+Z3jKzfGY=; b=cpInLRi0HWsgeXSzdA+M7j4KW1nX9uzU/MZYN3M30hPsWiaijsvG5BtIMJXmiTliYr vU3/nxYVB26JsXTffnOrsx+LfZQt4byh4UyOt7VenNOEiR9ZT/K8O5cYj8Y0J/zFB82c adi14U0MC8ZWQq1v1X4lqsmR6FRb1hzfNyQ4abYN+KbIp8xewoemU3JF2sq8sqJTGp8Q 8SscBXXDUcL1c7bAQRZ4s1JP96HYJcNP5cJ8aRBxDZjY3TsbHVf/HmJtw2I3KAxMxXm5 jEfFjXKr3M2LAUlwab/KPadDa1R8WZuCcHsuCVP3nJQvZp7aObnHKJT9Ubweyqc5rK8k EmUg== X-Gm-Message-State: ACgBeo02wNT4zO/ayp1PAyzZ9eHBW8q9fPiAAH8JhAKAbKevbkzmr89a CEHyPD+s8oXwq2+gd04TxZAD1XgXpb5yPT0iz7RUT1tI7Z3jlysroyT+AKZ7697ikVoQiuhxWFd 51+tlCbeSLLnRXFrWW9hadvgYIth9yYTnvj4+3D9TBLwABGdQ6Tzk6mrDVImu55B81NC3HPPegI w= X-Google-Smtp-Source: AA6agR7xKDGBgs3XbZP61oAPUQ8TxmvzSHJrLMekf3JpU4nP/Wgbad6sxQc2uWSrqsH3qB1eoqsdEA== X-Received: by 2002:a17:907:869e:b0:74f:2465:82a8 with SMTP id qa30-20020a170907869e00b0074f246582a8mr15527275ejc.729.1662885992521; Sun, 11 Sep 2022 01:46:32 -0700 (PDT) Received: from localhost.localdomain ([141.226.162.95]) by smtp.gmail.com with ESMTPSA id q10-20020a170906360a00b007309a570bacsm2713591ejb.176.2022.09.11.01.46.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 11 Sep 2022 01:46:32 -0700 (PDT) From: Shmulik Ladkani X-Google-Original-From: Shmulik Ladkani To: bpf@vger.kernel.org, Daniel Borkmann , John Fastabend , Joanne Koong , Andrii Nakryiko Cc: Alexei Starovoitov , Paul Chaignon , Shmulik Ladkani Subject: [PATCH v6 bpf-next 2/4] bpf: Support setting variable-length tunnel options Date: Sun, 11 Sep 2022 11:46:07 +0300 Message-Id: <20220911084609.102519-3-shmulik.ladkani@gmail.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220911084609.102519-1-shmulik.ladkani@gmail.com> References: <20220911084609.102519-1-shmulik.ladkani@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Existing 'bpf_skb_set_tunnel_opt' allows setting tunnel options given an option buffer (ARG_PTR_TO_MEM) and the compile-time fixed buffer size (ARG_CONST_SIZE). However, in certain cases we wish to set tunnel options of dynamic length. For example, we have an ebpf program that gets geneve options on incoming packets, stores them into a map (using a key representing the incoming flow), and later needs to assign *same* options to reply packets (belonging to same flow). This is currently imposssible without knowing sender's exact geneve options length, which unfortunately is dymamic. Introduce 'bpf_skb_set_tunnel_opt_dynptr'. This is a variant of 'bpf_skb_set_tunnel_opt' which gets a bpf dynamic pointer (ARG_PTR_TO_DYNPTR) parameter whose data points to the options buffer to set. Signed-off-by: Shmulik Ladkani Reported-by: kernel test robot Reported-by: kernel test robot --- v3: Avoid 'inline' for the __bpf_skb_set_tunopt helper function v4: change API to be based on bpf_dynptr, suggested by John Fastabend v6: Remove superfluous 'len' from bpf_skb_set_tunnel_opt_dynptr API (rely on dynptr's internal size), suggested by Andrii Nakryiko --- include/uapi/linux/bpf.h | 11 +++++++++++ net/core/filter.c | 31 +++++++++++++++++++++++++++++-- tools/include/uapi/linux/bpf.h | 11 +++++++++++ 3 files changed, 51 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 3df78c56c1bf..ba12f7e1ccb6 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5387,6 +5387,16 @@ union bpf_attr { * Return * Current *ktime*. * + * long bpf_skb_set_tunnel_opt_dynptr(struct sk_buff *skb, struct bpf_dynptr *opt) + * Description + * Set tunnel options metadata for the packet associated to *skb* + * to the option data pointed to by the *opt* dynptr. + * + * See also the description of the **bpf_skb_get_tunnel_opt**\ () + * helper for additional information. + * Return + * 0 on success, or a negative error in case of failure. + * */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5598,6 +5608,7 @@ union bpf_attr { FN(tcp_raw_check_syncookie_ipv4), \ FN(tcp_raw_check_syncookie_ipv6), \ FN(ktime_get_tai_ns), \ + FN(skb_set_tunnel_opt_dynptr), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/net/core/filter.c b/net/core/filter.c index e872f45399b0..1c652936ef86 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4674,8 +4674,7 @@ static const struct bpf_func_proto bpf_skb_set_tunnel_key_proto = { .arg4_type = ARG_ANYTHING, }; -BPF_CALL_3(bpf_skb_set_tunnel_opt, struct sk_buff *, skb, - const u8 *, from, u32, size) +static u64 __bpf_skb_set_tunopt(struct sk_buff *skb, const u8 *from, u32 size) { struct ip_tunnel_info *info = skb_tunnel_info(skb); const struct metadata_dst *md = this_cpu_ptr(md_dst); @@ -4690,6 +4689,22 @@ BPF_CALL_3(bpf_skb_set_tunnel_opt, struct sk_buff *, skb, return 0; } +BPF_CALL_3(bpf_skb_set_tunnel_opt, struct sk_buff *, skb, + const u8 *, from, u32, size) +{ + return __bpf_skb_set_tunopt(skb, from, size); +} + +BPF_CALL_2(bpf_skb_set_tunnel_opt_dynptr, struct sk_buff *, skb, + struct bpf_dynptr_kern *, ptr) +{ + const u8 *from = bpf_dynptr_get_data(ptr); + + if (unlikely(!from)) + return -EFAULT; + return __bpf_skb_set_tunopt(skb, from, bpf_dynptr_get_size(ptr)); +} + static const struct bpf_func_proto bpf_skb_set_tunnel_opt_proto = { .func = bpf_skb_set_tunnel_opt, .gpl_only = false, @@ -4699,6 +4714,14 @@ static const struct bpf_func_proto bpf_skb_set_tunnel_opt_proto = { .arg3_type = ARG_CONST_SIZE, }; +static const struct bpf_func_proto bpf_skb_set_tunnel_opt_dynptr_proto = { + .func = bpf_skb_set_tunnel_opt_dynptr, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL, +}; + static const struct bpf_func_proto * bpf_get_skb_set_tunnel_proto(enum bpf_func_id which) { @@ -4719,6 +4742,8 @@ bpf_get_skb_set_tunnel_proto(enum bpf_func_id which) return &bpf_skb_set_tunnel_key_proto; case BPF_FUNC_skb_set_tunnel_opt: return &bpf_skb_set_tunnel_opt_proto; + case BPF_FUNC_skb_set_tunnel_opt_dynptr: + return &bpf_skb_set_tunnel_opt_dynptr_proto; default: return NULL; } @@ -7798,6 +7823,7 @@ tc_cls_act_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_skb_get_tunnel_opt: return &bpf_skb_get_tunnel_opt_proto; case BPF_FUNC_skb_set_tunnel_opt: + case BPF_FUNC_skb_set_tunnel_opt_dynptr: return bpf_get_skb_set_tunnel_proto(func_id); case BPF_FUNC_redirect: return &bpf_redirect_proto; @@ -8145,6 +8171,7 @@ lwt_xmit_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_skb_get_tunnel_opt: return &bpf_skb_get_tunnel_opt_proto; case BPF_FUNC_skb_set_tunnel_opt: + case BPF_FUNC_skb_set_tunnel_opt_dynptr: return bpf_get_skb_set_tunnel_proto(func_id); case BPF_FUNC_redirect: return &bpf_redirect_proto; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 3df78c56c1bf..ba12f7e1ccb6 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5387,6 +5387,16 @@ union bpf_attr { * Return * Current *ktime*. * + * long bpf_skb_set_tunnel_opt_dynptr(struct sk_buff *skb, struct bpf_dynptr *opt) + * Description + * Set tunnel options metadata for the packet associated to *skb* + * to the option data pointed to by the *opt* dynptr. + * + * See also the description of the **bpf_skb_get_tunnel_opt**\ () + * helper for additional information. + * Return + * 0 on success, or a negative error in case of failure. + * */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5598,6 +5608,7 @@ union bpf_attr { FN(tcp_raw_check_syncookie_ipv4), \ FN(tcp_raw_check_syncookie_ipv6), \ FN(ktime_get_tai_ns), \ + FN(skb_set_tunnel_opt_dynptr), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper