From patchwork Tue Aug 23 13:30:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shmulik Ladkani X-Patchwork-Id: 12952290 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 DF308C32772 for ; Tue, 23 Aug 2022 16:59:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245691AbiHWQ74 (ORCPT ); Tue, 23 Aug 2022 12:59:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343560AbiHWQ73 (ORCPT ); Tue, 23 Aug 2022 12:59:29 -0400 Received: from mail-wr1-x42c.google.com (mail-wr1-x42c.google.com [IPv6:2a00:1450:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E223814CAC8 for ; Tue, 23 Aug 2022 06:30:42 -0700 (PDT) Received: by mail-wr1-x42c.google.com with SMTP id u5so9213294wrt.11 for ; Tue, 23 Aug 2022 06:30:42 -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; bh=10PDRhn4F3my8zVIsQ09j340gbFrNOpjbWkUgvpRj7M=; b=Ffk/NMqgiBkdyLphqpPOVg8cMVKI8RvRggHzLbLrWIbaU0wAQzgO+Q34cWthMKV9PR QHUFT+TA+BqBmj2COH6Gn5NYysEqJ5mPijwTk/UJXVSG5TCDvP8QFMHR0ZggHThUXO3l JbZe1oE3VxIloUoJMGC8DVTeYyapNMNiMLKAg= 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; bh=10PDRhn4F3my8zVIsQ09j340gbFrNOpjbWkUgvpRj7M=; b=a7Bwb4HDdayIxN/U8kFt5grZq32pvumCZBZhhyXTlqQrJQRLZ+ib1xrvorIWh6+/fd KISNt9FdmXRhUY7efsKJunFxkX7mugt+kogIS458phGN/U0QUhXhg826OipdJHOIN2lp Heq+GbwvZGEXW2/S5zvZrdidg4AJU9khQz0RIRxihfTi1Ddu7flhniQhMytRiENuDDgV qFj4zHivHs9TC2qJmcLUCNK5dP56/d2BzV7ypCN9GvVSQuFf7Mswng3n7bRPjrk+dGox y32sAroWs+eCtIy2YJMEpbvDEM5CccMqyC8Zp5i8ane/Y4CbRXPCc9UmLBQ529PWT8Ft Av/A== X-Gm-Message-State: ACgBeo3kfavexUIpnsXpnyr1fhVscGLtg0GNHh9HX02sicZ9w8mlhgOG MDqmKqR1tmHiVZRlf3zYCUm+W8Do5hLpn6Yx+jOkEYTViUgpAlfbh140j0DaRohpWHthXbLRP5L ZO1FxvBLVmElIf3Y5GM3V8u/fD7rtYgumXbtpJXiQ0HhV6SPWYxrYGUvrAXGytH3Cy24gLRI5 X-Google-Smtp-Source: AA6agR6KJh9QcLqzsoFPxQVog3j/NAfwlFixMGXFc9SJ0uabckvyHUnaPjCVq9jSsHdbSwf2SPI45Q== X-Received: by 2002:adf:e18b:0:b0:225:644c:59c2 with SMTP id az11-20020adfe18b000000b00225644c59c2mr2676449wrb.673.1661261440968; Tue, 23 Aug 2022 06:30:40 -0700 (PDT) Received: from blondie.home ([94.230.83.151]) by smtp.gmail.com with ESMTPSA id t9-20020a05600c198900b003a4efb794d7sm19264891wmq.36.2022.08.23.06.30.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Aug 2022 06:30:40 -0700 (PDT) From: Shmulik Ladkani X-Google-Original-From: Shmulik Ladkani To: bpf@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , John Fastabend Cc: Andrii Nakryiko , Paul Chaignon , Shmulik Ladkani Subject: [PATCH v4 bpf-next 2/4] bpf: Support setting variable-length tunnel options Date: Tue, 23 Aug 2022 16:30:18 +0300 Message-Id: <20220823133020.73872-3-shmulik.ladkani@gmail.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823133020.73872-1-shmulik.ladkani@gmail.com> References: <20220823133020.73872-1-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 'ptr' whose data points to the options buffer, and 'len', the byte length of options data caller wishes to copy into ip_tunnnel_info. 'len' must never exceed the dynptr's internal size, o/w EINVAL is returned. Signed-off-by: Shmulik Ladkani --- v3: Avoid 'inline' for the __bpf_skb_set_tunopt helper function v4: change API to be based on bpf_dynptr, suggested by John Fastabend --- include/uapi/linux/bpf.h | 12 ++++++++++++ net/core/filter.c | 36 ++++++++++++++++++++++++++++++++-- tools/include/uapi/linux/bpf.h | 12 ++++++++++++ 3 files changed, 58 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 934a2a8beb87..6d7eedf3644e 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5355,6 +5355,17 @@ union bpf_attr { * Return * Current *ktime*. * + * long bpf_skb_set_tunnel_opt_dynptr(struct sk_buff *skb, struct bpf_dynptr *opt, u32 len) + * Description + * Set tunnel options metadata for the packet associated to *skb* + * to the variable length *len* bytes of option data pointed to + * by the *opts* 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), \ @@ -5566,6 +5577,7 @@ 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 1acfaffeaf32..406ed0c50149 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4669,8 +4669,7 @@ 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); @@ -4685,6 +4684,26 @@ 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_3(bpf_skb_set_tunnel_opt_dynptr, struct sk_buff *, skb, + struct bpf_dynptr_kern *, ptr, u32, len) +{ + const u8 *from; + u32 avail; + + from = bpf_dynptr_get_data(ptr, &avail); + if (unlikely(!from)) + return -EFAULT; + if (unlikely(len > avail)) + return -EINVAL; + return __bpf_skb_set_tunopt(skb, from, len); +} + static const struct bpf_func_proto bpf_skb_set_tunnel_opt_proto = { .func = bpf_skb_set_tunnel_opt, .gpl_only = false, @@ -4694,6 +4713,15 @@ 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, + .arg3_type = ARG_ANYTHING, +}; + static const struct bpf_func_proto * bpf_get_skb_set_tunnel_proto(enum bpf_func_id which) { @@ -4714,6 +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; } @@ -7826,6 +7856,7 @@ 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; @@ -8169,6 +8200,7 @@ 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 1d6085e15fc8..b9bbccd1e5fa 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5355,6 +5355,17 @@ union bpf_attr { * Return * Current *ktime*. * + * long bpf_skb_set_tunnel_opt_dynptr(struct sk_buff *skb, struct bpf_dynptr *opt, u32 len) + * Description + * Set tunnel options metadata for the packet associated to *skb* + * to the variable length *len* bytes of option data pointed to + * by the *opts* 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), \ @@ -5566,6 +5577,7 @@ 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