From patchwork Mon Aug 22 05:21:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shmulik Ladkani X-Patchwork-Id: 12950194 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 F3414C28D13 for ; Mon, 22 Aug 2022 05:22:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232252AbiHVFWM (ORCPT ); Mon, 22 Aug 2022 01:22:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54340 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231500AbiHVFWL (ORCPT ); Mon, 22 Aug 2022 01:22:11 -0400 Received: from mail-wr1-x435.google.com (mail-wr1-x435.google.com [IPv6:2a00:1450:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 102CE25596 for ; Sun, 21 Aug 2022 22:22:10 -0700 (PDT) Received: by mail-wr1-x435.google.com with SMTP id b5so7485125wrr.5 for ; Sun, 21 Aug 2022 22:22:09 -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=ovk2dLdgVovDMaKK+ISMk7hpEgxuG91JBtNJ8DlajTw=; b=WP0D+b7WSX/ulcWOPq47UzRWx/7BWTbbQCfLnxGAUQsuf1ic6X+3Zt/2rnYpB5UvTD X4e98+4ibJBZJ5ATNKXuN/PSKCqqjGxNKEQa+ciZT+6xNpY9JxSVRwVzUG5r3IWLyTNF 6ksBc9gg3P+38xQxbvff2isTepcC6KoG8fKME= 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=ovk2dLdgVovDMaKK+ISMk7hpEgxuG91JBtNJ8DlajTw=; b=U992TzskCfMOJ9USSQCdl4yqppBf78GTa3xDe4mckT2HjEvIVjF80rdYgpROteaoKt SSbsuNulrxMpSElp4nat9kQk9vSO5QpphourZeslvuy2VUml1CLZC6u6e2vCx6u4OVUF oWrtG0V961wP+VOZeEtS6AehT7dJH/Rqe19So22dyL6uLDQQhFbdc/Kv6ThqcXqrTu9y 2MMvEKwaetDrvD3cQ8kEIbkuYq2QWhtV7g5SRpYnRTdS6pJy0UR1mTfZB5RTZXbf/wJ0 Uo6W83Op6vn+pcHWk7MIZ5JHEM25aA/RLsPeJi0dX9JLKR+4nMhskxFOGP8KG9ScY1f0 j1fw== X-Gm-Message-State: ACgBeo3Bz3jk5xgmyROyeLnkg95sxOc6CkovdQ7GIA3/9pep9ffSNzuW J0PtAFlmuL+HWlEpWRqYnxer07xkr4NQz/GE5pY5ZHfb+8qOtrriqMP8yAG4sCCPyX46+g8OZHg n/LZlIjbNVOLlW0p1ehFO7X4EuRvBgrxHCjDre7qCsyIOiua9qUsAN+OrSoKvA6hmISFl+b3B X-Google-Smtp-Source: AA6agR7cbRbKONXug9k0v9kUJEbJd9etEKh6wuY7xlCl6MKbzJQhlfKdZk82YcGwhegEH4fLb8EZ+A== X-Received: by 2002:adf:fb0e:0:b0:21a:34a2:5ca9 with SMTP id c14-20020adffb0e000000b0021a34a25ca9mr9902486wrr.472.1661145728179; Sun, 21 Aug 2022 22:22:08 -0700 (PDT) Received: from blondie.home ([94.230.83.151]) by smtp.gmail.com with ESMTPSA id z24-20020a1cf418000000b003a5dadcf1a8sm13163173wma.19.2022.08.21.22.22.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 21 Aug 2022 22:22:07 -0700 (PDT) From: Shmulik Ladkani X-Google-Original-From: Shmulik Ladkani To: bpf@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann Cc: Andrii Nakryiko , Paul Chaignon , Shmulik Ladkani Subject: [PATCH v3 bpf-next 1/3] bpf: Support setting variable-length tunnel options Date: Mon, 22 Aug 2022 08:21:50 +0300 Message-Id: <20220822052152.378622-2-shmulik.ladkani@gmail.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220822052152.378622-1-shmulik.ladkani@gmail.com> References: <20220822052152.378622-1-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|MEM_RDONLY) 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 imposssibly without knowing sender's exact geneve options length, which unfortunately is dymamic. Introduce 'skb_set_var_tunnel_opt'. This is a variant of 'bpf_skb_set_tunnel_opt' which gets an *additional* parameter 'len', which is the byte length from 'opt' buffer to copy into ip_tunnnel_info. The 'size' parameter is kept ARG_CONST_SIZE. This way, verifier can still safe-guard buffer access. 'len' must never exceed 'size', o/w EINVAL is returned. Signed-off-by: Shmulik Ladkani --- v3: Avoid 'inline' for the __bpf_skb_set_tunopt helper function --- include/uapi/linux/bpf.h | 12 ++++++++++++ net/core/filter.c | 34 +++++++++++++++++++++++++++++++--- tools/include/uapi/linux/bpf.h | 12 ++++++++++++ 3 files changed, 55 insertions(+), 3 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 934a2a8beb87..1b965dfd0c80 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_var_tunnel_opt(struct sk_buff *skb, void *opt, u32 size, u32 len) + * Description + * Set tunnel options metadata for the packet associated to *skb* + * to the variable length *len* bytes of option data contained in + * the raw buffer *opt* sized *size*. + * + * 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_var_tunnel_opt), \ /* */ /* 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..02161a3344fd 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4669,8 +4669,8 @@ 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, u32 len) { struct ip_tunnel_info *info = skb_tunnel_info(skb); const struct metadata_dst *md = this_cpu_ptr(md_dst); @@ -4679,12 +4679,26 @@ BPF_CALL_3(bpf_skb_set_tunnel_opt, struct sk_buff *, skb, return -EINVAL; if (unlikely(size > IP_TUNNEL_OPTS_MAX)) return -ENOMEM; + if (unlikely(len > size)) + return -EINVAL; - ip_tunnel_info_opts_set(info, from, size, TUNNEL_OPTIONS_PRESENT); + ip_tunnel_info_opts_set(info, from, len, TUNNEL_OPTIONS_PRESENT); 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, size); +} + +BPF_CALL_4(bpf_skb_set_var_tunnel_opt, struct sk_buff *, skb, + const u8 *, from, u32, size, u32, len) +{ + return __bpf_skb_set_tunopt(skb, from, size, len); +} + static const struct bpf_func_proto bpf_skb_set_tunnel_opt_proto = { .func = bpf_skb_set_tunnel_opt, .gpl_only = false, @@ -4694,6 +4708,16 @@ 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_var_tunnel_opt_proto = { + .func = bpf_skb_set_var_tunnel_opt, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, + .arg3_type = ARG_CONST_SIZE, + .arg4_type = ARG_ANYTHING, +}; + static const struct bpf_func_proto * bpf_get_skb_set_tunnel_proto(enum bpf_func_id which) { @@ -4714,6 +4738,8 @@ 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_var_tunnel_opt: + return &bpf_skb_set_var_tunnel_opt_proto; default: return NULL; } @@ -7826,6 +7852,7 @@ 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_var_tunnel_opt: return bpf_get_skb_set_tunnel_proto(func_id); case BPF_FUNC_redirect: return &bpf_redirect_proto; @@ -8169,6 +8196,7 @@ 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_var_tunnel_opt: 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..1a1083db5b7a 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_var_tunnel_opt(struct sk_buff *skb, void *opt, u32 size, u32 len) + * Description + * Set tunnel options metadata for the packet associated to *skb* + * to the variable length *len* bytes of option data contained in + * the raw buffer *opt* sized *size*. + * + * 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_var_tunnel_opt), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper