From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19FC2C3F2D1 for ; Tue, 3 Mar 2020 20:05:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E04E32073B for ; Tue, 3 Mar 2020 20:05:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UrAE/WeJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728787AbgCCUFU (ORCPT ); Tue, 3 Mar 2020 15:05:20 -0500 Received: from mail-qt1-f195.google.com ([209.85.160.195]:41694 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728002AbgCCUFU (ORCPT ); Tue, 3 Mar 2020 15:05:20 -0500 Received: by mail-qt1-f195.google.com with SMTP id l21so3844180qtr.8; Tue, 03 Mar 2020 12:05:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=bSttz86+BMap7bbbGIPBZrmCtfnqk5FnhF3Vjoje2Qk=; b=UrAE/WeJtiDhtqfem+oRHag/ihR/uga7dD87ZNTL0ec/y41bVVWB96vUYQuFuxB24t LZ+C1fBpFYcbDk2h5LyNf+PoRk1RLa9PG8QkuIn23l0VAnmzBHmquxc0f9ZI990tX5Ja f5LB2xgPRkiN1PSYNP5IK6a8EA0N6pOGz8GdQp2dD2kQzjnEcLg+KDpPp+aaw9jias4P T4BsQD0C2NvXknQvB2Dn5iiwtDKLBtjjqvpptwQ2DlxVNdnbXykIXt3M63vdODIU4uHe WgHAa6eqrIEqUaRQYVTmUdHhYTt+46O4AL+lRBPK9f+wMezdO9LDirB4FCdrKd0JzpV+ zBBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bSttz86+BMap7bbbGIPBZrmCtfnqk5FnhF3Vjoje2Qk=; b=o/LQ/k573pJPzZFvj/53WB6AAKKVBCSeDdH7qZ3PvL+eQUaG8mIsCG2Aa6jx9J95LK bbHPQ/wkoxffoWPY4xb9lVRpMVGcNvFVpGJlmu9Z4J/3TK43/WbyfMHK8dgV35EAnU4k JPUN1FBG1vlOeXNiLv935bGR598bu+IaCghRvG1HUGmaFGGtPaxZnjkkiyM5k+sZfNuY XQV7ifZX6KFcn3wtwaB/vn/Elg7R4U5wx+nSMaEtl7riLSz5JY2zUwgBLMqA4O/3miOL dpKtemtGBNlljjs8IosUaRB+EuFF80V6bByIROwtz+2Z+CsOAFaHjW2d15cWwr1fPmYN ibJg== X-Gm-Message-State: ANhLgQ193icpxAr/1qrfEU/VFYT3sENfOKPJ9aBYj0FJeqqzFqo8aCca FHrc7yEMyuYA5/IJAyE4xHIj5aeL X-Google-Smtp-Source: ADFU+vvDVdPHOJJuvJbYgRHA/zZs/zMAzy/Fk6uyA0wHAFbX60ik6iRcIi791V0gDMLGy5sVuATryA== X-Received: by 2002:ac8:3533:: with SMTP id y48mr6074110qtb.380.1583265918919; Tue, 03 Mar 2020 12:05:18 -0800 (PST) Received: from willemb.nyc.corp.google.com ([2620:0:1003:312:37b5:dd03:b905:30ea]) by smtp.gmail.com with ESMTPSA id d7sm9846281qkg.62.2020.03.03.12.05.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Mar 2020 12:05:18 -0800 (PST) From: Willem de Bruijn To: bpf@vger.kernel.org Cc: netdev@vger.kernel.org, daniel@iogearbox.net, ast@kernel.org, Willem de Bruijn Subject: [PATCH bpf-next 1/3] bpf: add gso_size to __sk_buff Date: Tue, 3 Mar 2020 15:05:01 -0500 Message-Id: <20200303200503.226217-2-willemdebruijn.kernel@gmail.com> X-Mailer: git-send-email 2.25.0.265.gbab2e86ba0-goog In-Reply-To: <20200303200503.226217-1-willemdebruijn.kernel@gmail.com> References: <20200303200503.226217-1-willemdebruijn.kernel@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Willem de Bruijn BPF programs may want to know whether an skb is gso. The canonical answer is skb_is_gso(skb), which tests that gso_size != 0. Expose this field in the same manner as gso_segs. That field itself is not a sufficient signal, as the comment in skb_shared_info makes clear: gso_segs may be zero, e.g., from dodgy sources. Also prepare net/bpf/test_run for upcoming BPF_PROG_TEST_RUN tests of the feature. Signed-off-by: Willem de Bruijn --- include/uapi/linux/bpf.h | 1 + net/bpf/test_run.c | 7 +++++++ net/core/filter.c | 44 +++++++++++++++++++++++++++------------- 3 files changed, 38 insertions(+), 14 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 8e98ced0963b..180337fae97e 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3176,6 +3176,7 @@ struct __sk_buff { __u32 wire_len; __u32 gso_segs; __bpf_md_ptr(struct bpf_sock *, sk); + __u32 gso_size; }; struct bpf_tunnel_key { diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index 562443f94133..1cd7a1c2f8b2 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -277,6 +277,12 @@ static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb) /* gso_segs is allowed */ if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_segs), + offsetof(struct __sk_buff, gso_size))) + return -EINVAL; + + /* gso_size is allowed */ + + if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_size), sizeof(struct __sk_buff))) return -EINVAL; @@ -297,6 +303,7 @@ static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb) if (__skb->gso_segs > GSO_MAX_SEGS) return -EINVAL; skb_shinfo(skb)->gso_segs = __skb->gso_segs; + skb_shinfo(skb)->gso_size = __skb->gso_size; return 0; } diff --git a/net/core/filter.c b/net/core/filter.c index 4a08c9fb2be7..cd0a532db4e7 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -7139,6 +7139,27 @@ static u32 flow_dissector_convert_ctx_access(enum bpf_access_type type, return insn - insn_buf; } +static struct bpf_insn *bpf_convert_shinfo_access(const struct bpf_insn *si, + 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, + offsetof(struct sk_buff, end)); + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, head), + si->dst_reg, si->src_reg, + offsetof(struct sk_buff, head)); + *insn++ = BPF_ALU64_REG(BPF_ADD, si->dst_reg, BPF_REG_AX); +#else + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, end), + si->dst_reg, si->src_reg, + offsetof(struct sk_buff, end)); +#endif + + return insn; +} + static u32 bpf_convert_ctx_access(enum bpf_access_type type, const struct bpf_insn *si, struct bpf_insn *insn_buf, @@ -7461,26 +7482,21 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type, break; case offsetof(struct __sk_buff, gso_segs): - /* 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, - offsetof(struct sk_buff, end)); - *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, head), - si->dst_reg, si->src_reg, - offsetof(struct sk_buff, head)); - *insn++ = BPF_ALU64_REG(BPF_ADD, si->dst_reg, BPF_REG_AX); -#else - *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct sk_buff, end), - si->dst_reg, si->src_reg, - offsetof(struct sk_buff, end)); -#endif + insn = bpf_convert_shinfo_access(si, 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, gso_segs, 2, target_size)); break; + case offsetof(struct __sk_buff, gso_size): + insn = bpf_convert_shinfo_access(si, 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, + gso_size, 2, + target_size)); + break; case offsetof(struct __sk_buff, wire_len): BUILD_BUG_ON(sizeof_field(struct qdisc_skb_cb, pkt_len) != 4); -- 2.25.0.265.gbab2e86ba0-goog