From patchwork Fri Jul 21 20:22:45 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Xu X-Patchwork-Id: 13322510 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A3DC23BEA; Fri, 21 Jul 2023 20:24:31 +0000 (UTC) Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com [64.147.123.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0E1D4487; Fri, 21 Jul 2023 13:24:00 -0700 (PDT) Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailout.west.internal (Postfix) with ESMTP id 2745332009DD; Fri, 21 Jul 2023 16:23:06 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Fri, 21 Jul 2023 16:23:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dxuuu.xyz; h=cc :cc:content-transfer-encoding:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to; s=fm2; t=1689970985; x= 1690057385; bh=U14PeO4+rXqVyLZW6g7EGR1pARLExleSWSzTTiiVnD0=; b=O 9AZpXGtG1+nbrF+df1ZkaI9sWVwjcMNZ2tkAmkrxfA94xjQyGO0K20UAfn217jkW wQ2RA1c8r5pcVvEQixsI4JiOxoRxKYc+sJ6Gt9uruj+xxi0ASYkN2gDsOH4uDCjt xl0sJbM7l3bMnBbxeuZB5regErt4SjBHnLWU3/EeNlpNd4vuagxXYNmOcsfSD5Jx oyLBB8+d5/0BxL/dZzJHMVbw8nwMCtEJjUbcfQhoJ27+q0U+RjYBQ6ufFX4dsnxM R0z5zJaMN8Fpd/CDuw4yEvq/KMCNfNBqxLasG0qWzx+79C/3gCa7DqpJAhtO0cX7 tAtSF/JbNf/tBV0MGuk9w== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:feedback-id:feedback-id:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm3; t=1689970985; x= 1690057385; bh=U14PeO4+rXqVyLZW6g7EGR1pARLExleSWSzTTiiVnD0=; b=r D8J1ZMVLa6cetBxRc5F8peayoVjio3BOb1j+qdaIv1zePCJTRIoPreevyCF/pcNP qDbmsOs5GlpQiXIklu36WYRxQ2+qzVMh6SUfNvy9huXo5TneAyOewLeqVrM3r/Ey cqfNyPwDvgYXNt6iuNh4QulmnEwVkrBN8r0mqdZ83f06yIrOM5tbOlRPe4JjrcBD ObUk3OU08pZnKpttN/hH8ladIUxqXqkzIbtv6Mw1fqEBM7JOf/d/cZMfWae38W+/ m8Q1qPZDu9Wv1z4l0Fj1xI9dXBpXJxy7k/6CqyTBP7z4sNDIMNA20v4PqxocrH9U 55IFaW0wUnFnr1vQyoSVw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedviedrhedvgddugeefucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucgfrhhlucfvnfffucdljedtmdenucfjughrpefhvf evufffkffojghfggfgsedtkeertdertddtnecuhfhrohhmpeffrghnihgvlhcuighuuceo ugiguhesugiguhhuuhdrgiihiieqnecuggftrfgrthhtvghrnhepgfefgfegjefhudeike dvueetffelieefuedvhfehjeeljeejkefgffeghfdttdetnecuvehluhhsthgvrhfuihii vgeptdenucfrrghrrghmpehmrghilhhfrhhomhepugiguhesugiguhhuuhdrgiihii X-ME-Proxy: Feedback-ID: i6a694271:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 21 Jul 2023 16:23:04 -0400 (EDT) From: Daniel Xu To: kadlec@netfilter.org, edumazet@google.com, fw@strlen.de, kuba@kernel.org, pabeni@redhat.com, pablo@netfilter.org, dsahern@kernel.org, davem@davemloft.net, alexei.starovoitov@gmail.com, daniel@iogearbox.net Cc: netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH bpf-next v6 1/5] netfilter: defrag: Add glue hooks for enabling/disabling defrag Date: Fri, 21 Jul 2023 14:22:45 -0600 Message-ID: X-Mailer: git-send-email 2.41.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_PASS,SPF_PASS, T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net We want to be able to enable/disable IP packet defrag from core bpf/netfilter code. In other words, execute code from core that could possibly be built as a module. To help avoid symbol resolution errors, use glue hooks that the modules will register callbacks with during module init. Signed-off-by: Daniel Xu Reviewed-by: Florian Westphal --- include/linux/netfilter.h | 10 ++++++++++ net/ipv4/netfilter/nf_defrag_ipv4.c | 17 ++++++++++++++++- net/ipv6/netfilter/nf_defrag_ipv6_hooks.c | 11 +++++++++++ net/netfilter/core.c | 6 ++++++ 4 files changed, 43 insertions(+), 1 deletion(-) diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index d4fed4c508ca..d68644b7c299 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -481,6 +482,15 @@ struct nfnl_ct_hook { }; extern const struct nfnl_ct_hook __rcu *nfnl_ct_hook; +struct nf_defrag_hook { + struct module *owner; + int (*enable)(struct net *net); + void (*disable)(struct net *net); +}; + +extern const struct nf_defrag_hook __rcu *nf_defrag_v4_hook; +extern const struct nf_defrag_hook __rcu *nf_defrag_v6_hook; + /* * nf_skb_duplicated - TEE target has sent a packet * diff --git a/net/ipv4/netfilter/nf_defrag_ipv4.c b/net/ipv4/netfilter/nf_defrag_ipv4.c index e61ea428ea18..a9ba7de092c4 100644 --- a/net/ipv4/netfilter/nf_defrag_ipv4.c +++ b/net/ipv4/netfilter/nf_defrag_ipv4.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -113,17 +114,31 @@ static void __net_exit defrag4_net_exit(struct net *net) } } +static const struct nf_defrag_hook defrag_hook = { + .owner = THIS_MODULE, + .enable = nf_defrag_ipv4_enable, + .disable = nf_defrag_ipv4_disable, +}; + static struct pernet_operations defrag4_net_ops = { .exit = defrag4_net_exit, }; static int __init nf_defrag_init(void) { - return register_pernet_subsys(&defrag4_net_ops); + int err; + + err = register_pernet_subsys(&defrag4_net_ops); + if (err) + return err; + + rcu_assign_pointer(nf_defrag_v4_hook, &defrag_hook); + return err; } static void __exit nf_defrag_fini(void) { + rcu_assign_pointer(nf_defrag_v4_hook, NULL); unregister_pernet_subsys(&defrag4_net_ops); } diff --git a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c index cb4eb1d2c620..d59b296b4f51 100644 --- a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c +++ b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include @@ -96,6 +97,12 @@ static void __net_exit defrag6_net_exit(struct net *net) } } +static const struct nf_defrag_hook defrag_hook = { + .owner = THIS_MODULE, + .enable = nf_defrag_ipv6_enable, + .disable = nf_defrag_ipv6_disable, +}; + static struct pernet_operations defrag6_net_ops = { .exit = defrag6_net_exit, }; @@ -114,6 +121,9 @@ static int __init nf_defrag_init(void) pr_err("nf_defrag_ipv6: can't register pernet ops\n"); goto cleanup_frag6; } + + rcu_assign_pointer(nf_defrag_v6_hook, &defrag_hook); + return ret; cleanup_frag6: @@ -124,6 +134,7 @@ static int __init nf_defrag_init(void) static void __exit nf_defrag_fini(void) { + rcu_assign_pointer(nf_defrag_v6_hook, NULL); unregister_pernet_subsys(&defrag6_net_ops); nf_ct_frag6_cleanup(); } diff --git a/net/netfilter/core.c b/net/netfilter/core.c index 5f76ae86a656..ef4e76e5aef9 100644 --- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -680,6 +680,12 @@ EXPORT_SYMBOL_GPL(nfnl_ct_hook); const struct nf_ct_hook __rcu *nf_ct_hook __read_mostly; EXPORT_SYMBOL_GPL(nf_ct_hook); +const struct nf_defrag_hook __rcu *nf_defrag_v4_hook __read_mostly; +EXPORT_SYMBOL_GPL(nf_defrag_v4_hook); + +const struct nf_defrag_hook __rcu *nf_defrag_v6_hook __read_mostly; +EXPORT_SYMBOL_GPL(nf_defrag_v6_hook); + #if IS_ENABLED(CONFIG_NF_CONNTRACK) u8 nf_ctnetlink_has_listener; EXPORT_SYMBOL_GPL(nf_ctnetlink_has_listener); From patchwork Fri Jul 21 20:22:46 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Xu X-Patchwork-Id: 13322511 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AA4B524162; Fri, 21 Jul 2023 20:24:35 +0000 (UTC) Received: from wnew4-smtp.messagingengine.com (wnew4-smtp.messagingengine.com [64.147.123.18]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 128293AA4; Fri, 21 Jul 2023 13:24:05 -0700 (PDT) Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailnew.west.internal (Postfix) with ESMTP id 0B4E52B00099; Fri, 21 Jul 2023 16:23:09 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Fri, 21 Jul 2023 16:23:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dxuuu.xyz; h=cc :cc:content-transfer-encoding:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to; s=fm2; t=1689970989; x= 1689978189; bh=EDxNOEbgLa8gl3gQjxhLoql3OoSwDYrcv1iI2rkEv7M=; b=R fjH50xHMAbUDPOitQFnWW5wwBq+p26rzbpmbRTQLR7te6zNMEhe8/ZgwHq27tRIx 86cxMdLxYSeq/pTpwfMToIC87tuEhpoEu3Y7yB56pJBbSTcNFtQY7eqaHo9O6Tct eo4Fxyxsz/DG+UM8aLiI2d2T07xc0c0qamUDYFkJOjRreEfsC9Xj0T3S8QxsEwyh xcPOu3tVi7bDAnSiW2FbNN5WkngIMclfNsKpICXYXe+nGiypKRXt4dbYKbf5esgw N/HNd7SgT6+1zeoNCMpa31E9b5fWvE+27lxdyxHConI5l1JswITUXq09+/1OcHQY KUqB9ZkIUo7eCuy17fIVw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:feedback-id:feedback-id:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm3; t=1689970989; x= 1689978189; bh=EDxNOEbgLa8gl3gQjxhLoql3OoSwDYrcv1iI2rkEv7M=; b=E wQACD6msiaD0YiqTcFqfZdknIE2HimtT1Ynj1nG8d9Ss3wQ/Vd4J3L7xiO1nSWnU bPWWRUwE7bwLtkLR6Xp/5Ykz92T48wAnKghjQSS7Z4j8nb0KMxjdEncIGirn+NGX uKMkRUbMQ1BcFeyiHl3ZLwMkCXONFxZ3MdMIM/TG8f1/GOuUcq1Rx/5H1QBoXpoQ I5zvPMlYFN8nw9dnLLfaVdN5S3pt32zEa5NZNijrP/UxfEJNB5xuvbkrt5WAQR/m ijRsadTgyjWhYaogvUPp9IrxcxDmv3/ZOs99J+nwKwR9Yjo64wwcw/JqYsdLkqTF cSt2Y3kuCBHzduvDwChsw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedviedrhedvgddugeefucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucgfrhhlucfvnfffucdljedtmdenucfjughrpefhvf evufffkffojghfggfgsedtkeertdertddtnecuhfhrohhmpeffrghnihgvlhcuighuuceo ugiguhesugiguhhuuhdrgiihiieqnecuggftrfgrthhtvghrnhepjeegveeljeehvdevud duffffleelveejueegjedvhedvhedvheethfejgedtieeinecuffhomhgrihhnpehnvght fhhilhhtvghrrdhpfhenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrih hlfhhrohhmpegugihusegugihuuhhurdighiii X-ME-Proxy: Feedback-ID: i6a694271:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 21 Jul 2023 16:23:07 -0400 (EDT) From: Daniel Xu To: daniel@iogearbox.net, kadlec@netfilter.org, edumazet@google.com, ast@kernel.org, fw@strlen.de, kuba@kernel.org, pabeni@redhat.com, pablo@netfilter.org, andrii@kernel.org, davem@davemloft.net, alexei.starovoitov@gmail.com Cc: martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, dsahern@kernel.org Subject: [PATCH bpf-next v6 2/5] netfilter: bpf: Support BPF_F_NETFILTER_IP_DEFRAG in netfilter link Date: Fri, 21 Jul 2023 14:22:46 -0600 Message-ID: <5cff26f97e55161b7d56b09ddcf5f8888a5add1d.1689970773.git.dxu@dxuuu.xyz> X-Mailer: git-send-email 2.41.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_LOW,SPF_HELO_PASS, SPF_PASS,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net This commit adds support for enabling IP defrag using pre-existing netfilter defrag support. Basically all the flag does is bump a refcnt while the link the active. Checks are also added to ensure the prog requesting defrag support is run _after_ netfilter defrag hooks. We also take care to avoid any issues w.r.t. module unloading -- while defrag is active on a link, the module is prevented from unloading. Signed-off-by: Daniel Xu Reviewed-by: Florian Westphal --- include/uapi/linux/bpf.h | 5 ++ net/netfilter/nf_bpf_link.c | 123 +++++++++++++++++++++++++++++---- tools/include/uapi/linux/bpf.h | 5 ++ 3 files changed, 118 insertions(+), 15 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 739c15906a65..12a5480314a2 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1187,6 +1187,11 @@ enum bpf_perf_event_type { */ #define BPF_F_KPROBE_MULTI_RETURN (1U << 0) +/* link_create.netfilter.flags used in LINK_CREATE command for + * BPF_PROG_TYPE_NETFILTER to enable IP packet defragmentation. + */ +#define BPF_F_NETFILTER_IP_DEFRAG (1U << 0) + /* When BPF ldimm64's insn[0].src_reg != 0 then this can have * the following extensions: * diff --git a/net/netfilter/nf_bpf_link.c b/net/netfilter/nf_bpf_link.c index c36da56d756f..8fe594bbc7e2 100644 --- a/net/netfilter/nf_bpf_link.c +++ b/net/netfilter/nf_bpf_link.c @@ -1,6 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 #include #include +#include +#include #include #include @@ -23,8 +25,88 @@ struct bpf_nf_link { struct nf_hook_ops hook_ops; struct net *net; u32 dead; + const struct nf_defrag_hook *defrag_hook; }; +static const struct nf_defrag_hook * +get_proto_defrag_hook(struct bpf_nf_link *link, + const struct nf_defrag_hook __rcu *global_hook, + const char *mod) +{ + const struct nf_defrag_hook *hook; + int err; + + /* RCU protects us from races against module unloading */ + rcu_read_lock(); + hook = rcu_dereference(global_hook); + if (!hook) { + rcu_read_unlock(); + err = request_module(mod); + if (err) + return ERR_PTR(err < 0 ? err : -EINVAL); + + rcu_read_lock(); + hook = rcu_dereference(global_hook); + } + + if (hook && try_module_get(hook->owner)) { + /* Once we have a refcnt on the module, we no longer need RCU */ + hook = rcu_pointer_handoff(hook); + } else { + WARN_ONCE(!hook, "%s has bad registration", mod); + hook = ERR_PTR(-ENOENT); + } + rcu_read_unlock(); + + if (!IS_ERR(hook)) { + err = hook->enable(link->net); + if (err) { + module_put(hook->owner); + hook = ERR_PTR(err); + } + } + + return hook; +} + +static int bpf_nf_enable_defrag(struct bpf_nf_link *link) +{ + const struct nf_defrag_hook __maybe_unused *hook; + + switch (link->hook_ops.pf) { +#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) + case NFPROTO_IPV4: + hook = get_proto_defrag_hook(link, nf_defrag_v4_hook, "nf_defrag_ipv4"); + if (IS_ERR(hook)) + return PTR_ERR(hook); + + link->defrag_hook = hook; + return 0; +#endif +#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) + case NFPROTO_IPV6: + hook = get_proto_defrag_hook(link, nf_defrag_v6_hook, "nf_defrag_ipv6"); + if (IS_ERR(hook)) + return PTR_ERR(hook); + + link->defrag_hook = hook; + return 0; +#endif + default: + return -EAFNOSUPPORT; + } +} + +static void bpf_nf_disable_defrag(struct bpf_nf_link *link) +{ + const struct nf_defrag_hook *hook = link->defrag_hook; + + if (!hook) + return; + hook->disable(link->net); + module_put(hook->owner); +} + static void bpf_nf_link_release(struct bpf_link *link) { struct bpf_nf_link *nf_link = container_of(link, struct bpf_nf_link, link); @@ -32,11 +114,11 @@ static void bpf_nf_link_release(struct bpf_link *link) if (nf_link->dead) return; - /* prevent hook-not-found warning splat from netfilter core when - * .detach was already called - */ - if (!cmpxchg(&nf_link->dead, 0, 1)) + /* do not double release in case .detach was already called */ + if (!cmpxchg(&nf_link->dead, 0, 1)) { nf_unregister_net_hook(nf_link->net, &nf_link->hook_ops); + bpf_nf_disable_defrag(nf_link); + } } static void bpf_nf_link_dealloc(struct bpf_link *link) @@ -92,6 +174,8 @@ static const struct bpf_link_ops bpf_nf_link_lops = { static int bpf_nf_check_pf_and_hooks(const union bpf_attr *attr) { + int prio; + switch (attr->link_create.netfilter.pf) { case NFPROTO_IPV4: case NFPROTO_IPV6: @@ -102,19 +186,18 @@ static int bpf_nf_check_pf_and_hooks(const union bpf_attr *attr) return -EAFNOSUPPORT; } - if (attr->link_create.netfilter.flags) + if (attr->link_create.netfilter.flags & ~BPF_F_NETFILTER_IP_DEFRAG) return -EOPNOTSUPP; - /* make sure conntrack confirm is always last. - * - * In the future, if userspace can e.g. request defrag, then - * "defrag_requested && prio before NF_IP_PRI_CONNTRACK_DEFRAG" - * should fail. - */ - switch (attr->link_create.netfilter.priority) { - case NF_IP_PRI_FIRST: return -ERANGE; /* sabotage_in and other warts */ - case NF_IP_PRI_LAST: return -ERANGE; /* e.g. conntrack confirm */ - } + /* make sure conntrack confirm is always last */ + prio = attr->link_create.netfilter.priority; + if (prio == NF_IP_PRI_FIRST) + return -ERANGE; /* sabotage_in and other warts */ + else if (prio == NF_IP_PRI_LAST) + return -ERANGE; /* e.g. conntrack confirm */ + else if ((attr->link_create.netfilter.flags & BPF_F_NETFILTER_IP_DEFRAG) && + prio <= NF_IP_PRI_CONNTRACK_DEFRAG) + return -ERANGE; /* cannot use defrag if prog runs before nf_defrag */ return 0; } @@ -149,6 +232,7 @@ int bpf_nf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) link->net = net; link->dead = false; + link->defrag_hook = NULL; err = bpf_link_prime(&link->link, &link_primer); if (err) { @@ -156,8 +240,17 @@ int bpf_nf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) return err; } + if (attr->link_create.netfilter.flags & BPF_F_NETFILTER_IP_DEFRAG) { + err = bpf_nf_enable_defrag(link); + if (err) { + bpf_link_cleanup(&link_primer); + return err; + } + } + err = nf_register_net_hook(net, &link->hook_ops); if (err) { + bpf_nf_disable_defrag(link); bpf_link_cleanup(&link_primer); return err; } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 739c15906a65..12a5480314a2 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1187,6 +1187,11 @@ enum bpf_perf_event_type { */ #define BPF_F_KPROBE_MULTI_RETURN (1U << 0) +/* link_create.netfilter.flags used in LINK_CREATE command for + * BPF_PROG_TYPE_NETFILTER to enable IP packet defragmentation. + */ +#define BPF_F_NETFILTER_IP_DEFRAG (1U << 0) + /* When BPF ldimm64's insn[0].src_reg != 0 then this can have * the following extensions: * From patchwork Fri Jul 21 20:22:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Xu X-Patchwork-Id: 13322512 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EF2A12416A for ; Fri, 21 Jul 2023 20:24:35 +0000 (UTC) Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com [64.147.123.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 57FE33AAA; Fri, 21 Jul 2023 13:24:07 -0700 (PDT) Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.west.internal (Postfix) with ESMTP id 663DC32009DE; Fri, 21 Jul 2023 16:23:14 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute5.internal (MEProxy); Fri, 21 Jul 2023 16:23:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dxuuu.xyz; h=cc :cc:content-transfer-encoding:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to; s=fm2; t=1689970993; x= 1690057393; bh=C5gTyD3ZK69kBeMGtv3ULDgMyW30wlIrQqdN4DdpOCA=; b=M r9lwz78/xU1bSmpNST9J0dqZqO5ngRibRoBWppfwe6I6Fzc9EeX2INch8yl2gzTB f/RlTJDyW6K5ykuTGv1lO2YxRoGh+IuvW1OdDCnfGXSzAqKMzFZASfT6ncddniYk c46Qf+G7Fngn2Q2hoov+akTMH478atdQKrxYD0B5Oq7oh3Vn7iTiYX5dkQURZ5Lu p7sZpM9MZ8RCJX6u4j23DqTQR5E9QUxQu6rWJ/8On9LsXXhmbRLPA/qNdBzOWOED cLcmr1QrqsHUV8Otso3sQk3icVchJIhLdMl2N21NYl8bbfZe9u0Sm/sL4z3EqchG BjaZNZQjIOMGf6hFiPcDQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:feedback-id:feedback-id:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm3; t=1689970993; x= 1690057393; bh=C5gTyD3ZK69kBeMGtv3ULDgMyW30wlIrQqdN4DdpOCA=; b=E LwJaZ4dIvF/aTyE+ZtU+1nRXJDExp9MjPNU7m/zy/k39NQ7ulS5Tbgwv6ciH/tJF J8YvXcA3UiY5nvHXV6TJPCQIGwmFZ23uQ2HsGqpXqxscXmHMcpJJ16E71Xy77hzp vcIWr9lbB/zP8cdrIOTZKK04s+Xz58zUoRhpQ3Shc1d4PUiiXXKzxSlE6qCd9cfY 8jkMO4mhQ9sSC6KJAqY/IP7dM0cE85MSxKTz9z5BqE6e1xLgX8aTKs6sCw14lMhc OjrEWXXQqsKNyJCp/d4wRoPnuHwr0v5/kf3QE7IP79jKdQ4HGSuW6b0uDpJ1feQh a02L8Qf8GSkKJT8w45O/g== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedviedrhedvgddugedvucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucgfrhhlucfvnfffucdljedtmdenucfjughrpefhvf evufffkffojghfggfgsedtkeertdertddtnecuhfhrohhmpeffrghnihgvlhcuighuuceo ugiguhesugiguhhuuhdrgiihiieqnecuggftrfgrthhtvghrnhepgfefgfegjefhudeike dvueetffelieefuedvhfehjeeljeejkefgffeghfdttdetnecuvehluhhsthgvrhfuihii vgeptdenucfrrghrrghmpehmrghilhhfrhhomhepugiguhesugiguhhuuhdrgiihii X-ME-Proxy: Feedback-ID: i6a694271:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 21 Jul 2023 16:23:12 -0400 (EDT) From: Daniel Xu To: ast@kernel.org, daniel@iogearbox.net, shuah@kernel.org, andrii@kernel.org, alexei.starovoitov@gmail.com, fw@strlen.de Cc: mykolal@fb.com, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, dsahern@kernel.org Subject: [PATCH bpf-next v6 3/5] bpf: selftests: Support not connecting client socket Date: Fri, 21 Jul 2023 14:22:47 -0600 Message-ID: <525c13d66dac2d640a1db922546842c051c6f2e6.1689970773.git.dxu@dxuuu.xyz> X-Mailer: git-send-email 2.41.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_PASS,SPF_PASS, T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net For connectionless protocols or raw sockets we do not want to actually connect() to the server. Signed-off-by: Daniel Xu --- tools/testing/selftests/bpf/network_helpers.c | 5 +++-- tools/testing/selftests/bpf/network_helpers.h | 1 + 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c index a105c0cd008a..d5c78c08903b 100644 --- a/tools/testing/selftests/bpf/network_helpers.c +++ b/tools/testing/selftests/bpf/network_helpers.c @@ -301,8 +301,9 @@ int connect_to_fd_opts(int server_fd, const struct network_helper_opts *opts) strlen(opts->cc) + 1)) goto error_close; - if (connect_fd_to_addr(fd, &addr, addrlen, opts->must_fail)) - goto error_close; + if (!opts->noconnect) + if (connect_fd_to_addr(fd, &addr, addrlen, opts->must_fail)) + goto error_close; return fd; diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h index 694185644da6..87894dc984dd 100644 --- a/tools/testing/selftests/bpf/network_helpers.h +++ b/tools/testing/selftests/bpf/network_helpers.h @@ -21,6 +21,7 @@ struct network_helper_opts { const char *cc; int timeout_ms; bool must_fail; + bool noconnect; }; /* ipv4 test vector */ From patchwork Fri Jul 21 20:22:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Xu X-Patchwork-Id: 13322514 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4DE5223BDB for ; Fri, 21 Jul 2023 20:24:43 +0000 (UTC) Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com [64.147.123.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2ED9D35AB; Fri, 21 Jul 2023 13:24:16 -0700 (PDT) Received: from compute2.internal (compute2.nyi.internal [10.202.2.46]) by mailout.west.internal (Postfix) with ESMTP id ABBED32009F4; Fri, 21 Jul 2023 16:23:18 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute2.internal (MEProxy); Fri, 21 Jul 2023 16:23:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dxuuu.xyz; h=cc :cc:content-transfer-encoding:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to; s=fm2; t=1689970998; x= 1690057398; bh=jCzr01pZ2u8uI49LnXSVMw7KSVSfUH7qENNmnpv8K+w=; b=c b7zG3oFExMrI+w/UD1VGWjgW5chkIuAAXY/y2j/H/l63N/stHHvn/6vIuu9LJBY0 9sHl42fhagWhf+uXgpjN9EEAc8mxPcnh5rwUzkz8uhsAOMUFGLsdsG8VGldSf5k8 tQ95cy8/TMCgsqcrfWOyHuars8Cl59z95aRpEmusTYLnLBCX+SG2WwyZrPTmEwTd 9wOWEnLVPST7HciRZgAVwyYXmGYCzHqdmWXX8ye4qZ4BHQD0npj43aia/Tx1/awj dq4GTs1l7cMBovSJvHhrIMEtdfK5DE3oVBwyt6lTF/kyBi0WHSEyv4qMExKL5I/3 MnLdgPWANxgqqt0e1Xc+Q== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:feedback-id:feedback-id:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm3; t=1689970998; x= 1690057398; bh=jCzr01pZ2u8uI49LnXSVMw7KSVSfUH7qENNmnpv8K+w=; b=w 2JHpA304gdG9nI944Wg40kvf95XMXjx1IzUVd8LAz3hMeukCqOxSqQOO06aJvCb1 Gh9z42jOpFb9vOtCfGiJLtQEKZybTYAnXUb2ZlgwYugZX1cFCW3eLUnNwUCUA6BT P9zYAiCeY8jrukjCtt1eJEID04rFQf8m++AnmnI5kYHw4TfmtIskQgi+x77qC5+n jEBvXTIHm5mSscCfU5g5/d0xGkeGeRYoUty60R83j/WqqZi4qINsIxN6rkzAYmeD fAwXii8dilm2wYWy+yfZrRtXB8+v843uhfb7Gw25jSTX/WsdyoDOaw2TSXQh3jqA XpH2wNzKqYlbFP8etHjVA== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedviedrhedvgddugeefucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucgfrhhlucfvnfffucdljedtmdenucfjughrpefhvf evufffkffojghfggfgsedtkeertdertddtnecuhfhrohhmpeffrghnihgvlhcuighuuceo ugiguhesugiguhhuuhdrgiihiieqnecuggftrfgrthhtvghrnhepgfefgfegjefhudeike dvueetffelieefuedvhfehjeeljeejkefgffeghfdttdetnecuvehluhhsthgvrhfuihii vgeptdenucfrrghrrghmpehmrghilhhfrhhomhepugiguhesugiguhhuuhdrgiihii X-ME-Proxy: Feedback-ID: i6a694271:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 21 Jul 2023 16:23:16 -0400 (EDT) From: Daniel Xu To: andrii@kernel.org, daniel@iogearbox.net, shuah@kernel.org, ast@kernel.org, alexei.starovoitov@gmail.com, fw@strlen.de Cc: mykolal@fb.com, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, dsahern@kernel.org Subject: [PATCH bpf-next v6 4/5] bpf: selftests: Support custom type and proto for client sockets Date: Fri, 21 Jul 2023 14:22:48 -0600 Message-ID: <9067db539efdfd608aa86a2b143c521337c111fc.1689970773.git.dxu@dxuuu.xyz> X-Mailer: git-send-email 2.41.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_PASS,SPF_PASS, T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net Extend connect_to_fd_opts() to take optional type and protocol parameters for the client socket. These parameters are useful when opening a raw socket to send IP fragments. Signed-off-by: Daniel Xu --- tools/testing/selftests/bpf/network_helpers.c | 21 +++++++++++++------ tools/testing/selftests/bpf/network_helpers.h | 2 ++ 2 files changed, 17 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c index d5c78c08903b..910d5d0470e6 100644 --- a/tools/testing/selftests/bpf/network_helpers.c +++ b/tools/testing/selftests/bpf/network_helpers.c @@ -270,14 +270,23 @@ int connect_to_fd_opts(int server_fd, const struct network_helper_opts *opts) opts = &default_opts; optlen = sizeof(type); - if (getsockopt(server_fd, SOL_SOCKET, SO_TYPE, &type, &optlen)) { - log_err("getsockopt(SOL_TYPE)"); - return -1; + + if (opts->type) { + type = opts->type; + } else { + if (getsockopt(server_fd, SOL_SOCKET, SO_TYPE, &type, &optlen)) { + log_err("getsockopt(SOL_TYPE)"); + return -1; + } } - if (getsockopt(server_fd, SOL_SOCKET, SO_PROTOCOL, &protocol, &optlen)) { - log_err("getsockopt(SOL_PROTOCOL)"); - return -1; + if (opts->proto) { + protocol = opts->proto; + } else { + if (getsockopt(server_fd, SOL_SOCKET, SO_PROTOCOL, &protocol, &optlen)) { + log_err("getsockopt(SOL_PROTOCOL)"); + return -1; + } } addrlen = sizeof(addr); diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/selftests/bpf/network_helpers.h index 87894dc984dd..5eccc67d1a99 100644 --- a/tools/testing/selftests/bpf/network_helpers.h +++ b/tools/testing/selftests/bpf/network_helpers.h @@ -22,6 +22,8 @@ struct network_helper_opts { int timeout_ms; bool must_fail; bool noconnect; + int type; + int proto; }; /* ipv4 test vector */ From patchwork Fri Jul 21 20:22:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Xu X-Patchwork-Id: 13322513 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8AF3B23BDB for ; Fri, 21 Jul 2023 20:24:40 +0000 (UTC) Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com [64.147.123.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5654C3C0A; Fri, 21 Jul 2023 13:24:12 -0700 (PDT) Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailout.west.internal (Postfix) with ESMTP id BE81232009FB; Fri, 21 Jul 2023 16:23:22 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Fri, 21 Jul 2023 16:23:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dxuuu.xyz; h=cc :cc:content-transfer-encoding:content-type:date:date:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to; s=fm2; t=1689971002; x= 1690057402; bh=pHJ3WM/f5mvNC37sOGI/E//Q68KS1biWJ3itF/VHnw8=; b=O uoJNnf34WwsAPkw6mzNQYULcBmjrFy+Z8mk2VtgWhc+4SNWq2O6IPTTRLDQ2eypz G0udQScB4NziS22A90Xme1eYr10N7xp0QdI9dmV+G14GOtJtGLS/Q8kg2CzKWIa7 xPALvjwxjwf/3k73s+xNAJBwAehX1zG0m5OT8K1tLd+KzHAVi7VoGJgNyJt0nXZL tdiCBVJpQsQCcMJJdELoDqu2VrEUI27PFIiLC8ExQeV75gYzm2t4RMsgdGHUTjY8 zyfYqrm0KEDwv+t+LUuretHVu9QKtEsJ61vaVvRuFUcA+Ykyxpn0DGpOA16LmWEe r66/LlQQfwa6kJulnDvEA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:feedback-id:feedback-id:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm3; t=1689971002; x= 1690057402; bh=pHJ3WM/f5mvNC37sOGI/E//Q68KS1biWJ3itF/VHnw8=; b=b E5SmHQAyh7e+bL0itHK3jfU95pHx2k0IfcXCRApDYSfne3LdPBRBKBYRPOHN/OwN zTRL6OPzFsiZst5S+6NyGk8xnP6S+Sz6H3NtJOcGRd9v018XYeRQd5qnNhSN4A1x fajdJjm76KT/6IUjZsoLklLlfn26yWtMgRSOLWiOlRYvMx8BJAvImbrZCeDJ5rmV tHyO9RY/OPNx3XUdpPee7l9eun/ztHXWhga84nZYFsA0yeUJj+0SNRPjIXtmFzeb hza/tD3+geG9YLwrOxHmqTQIJ6CSP0B76WJuLgI1MLhU14ouZlDC6+LwFD5Adr13 X61UZez4EAn3F1TpwzIXw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedviedrhedvgddugeefucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucgfrhhlucfvnfffucdljedtmdenucfjughrpefhvf evufffkffojghfggfgsedtkeertdertddtnecuhfhrohhmpeffrghnihgvlhcuighuuceo ugiguhesugiguhhuuhdrgiihiieqnecuggftrfgrthhtvghrnhepgfefgfegjefhudeike dvueetffelieefuedvhfehjeeljeejkefgffeghfdttdetnecuvehluhhsthgvrhfuihii vgepudenucfrrghrrghmpehmrghilhhfrhhomhepugiguhesugiguhhuuhdrgiihii X-ME-Proxy: Feedback-ID: i6a694271:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 21 Jul 2023 16:23:20 -0400 (EDT) From: Daniel Xu To: andrii@kernel.org, daniel@iogearbox.net, shuah@kernel.org, ast@kernel.org, alexei.starovoitov@gmail.com, fw@strlen.de Cc: mykolal@fb.com, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, netfilter-devel@vger.kernel.org, dsahern@kernel.org Subject: [PATCH bpf-next v6 5/5] bpf: selftests: Add defrag selftests Date: Fri, 21 Jul 2023 14:22:49 -0600 Message-ID: <33e40fdfddf43be93f2cb259303f132f46750953.1689970773.git.dxu@dxuuu.xyz> X-Mailer: git-send-email 2.41.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_PASS,SPF_PASS, T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net These selftests tests 2 major scenarios: the BPF based defragmentation can successfully be done and that packet pointers are invalidated after calls to the kfunc. The logic is similar for both ipv4 and ipv6. In the first scenario, we create a UDP client and UDP echo server. The the server side is fairly straightforward: we attach the prog and simply echo back the message. The on the client side, we send fragmented packets to and expect the reassembled message back from the server. Signed-off-by: Daniel Xu --- tools/testing/selftests/bpf/Makefile | 4 +- .../selftests/bpf/generate_udp_fragments.py | 90 ++++++ .../selftests/bpf/ip_check_defrag_frags.h | 57 ++++ .../bpf/prog_tests/ip_check_defrag.c | 283 ++++++++++++++++++ .../selftests/bpf/progs/ip_check_defrag.c | 104 +++++++ 5 files changed, 536 insertions(+), 2 deletions(-) create mode 100755 tools/testing/selftests/bpf/generate_udp_fragments.py create mode 100644 tools/testing/selftests/bpf/ip_check_defrag_frags.h create mode 100644 tools/testing/selftests/bpf/prog_tests/ip_check_defrag.c create mode 100644 tools/testing/selftests/bpf/progs/ip_check_defrag.c diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 882be03b179f..619df497fce5 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -565,8 +565,8 @@ TRUNNER_EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c \ network_helpers.c testing_helpers.c \ btf_helpers.c flow_dissector_load.h \ cap_helpers.c test_loader.c xsk.c disasm.c \ - json_writer.c unpriv_helpers.c - + json_writer.c unpriv_helpers.c \ + ip_check_defrag_frags.h TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read $(OUTPUT)/bpf_testmod.ko \ $(OUTPUT)/liburandom_read.so \ $(OUTPUT)/xdp_synproxy \ diff --git a/tools/testing/selftests/bpf/generate_udp_fragments.py b/tools/testing/selftests/bpf/generate_udp_fragments.py new file mode 100755 index 000000000000..2b8a1187991c --- /dev/null +++ b/tools/testing/selftests/bpf/generate_udp_fragments.py @@ -0,0 +1,90 @@ +#!/bin/env python3 +# SPDX-License-Identifier: GPL-2.0 + +""" +This script helps generate fragmented UDP packets. + +While it is technically possible to dynamically generate +fragmented packets in C, it is much harder to read and write +said code. `scapy` is relatively industry standard and really +easy to read / write. + +So we choose to write this script that generates a valid C +header. Rerun script and commit generated file after any +modifications. +""" + +import argparse +import os + +from scapy.all import * + + +# These constants must stay in sync with `ip_check_defrag.c` +VETH1_ADDR = "172.16.1.200" +VETH0_ADDR6 = "fc00::100" +VETH1_ADDR6 = "fc00::200" +CLIENT_PORT = 48878 +SERVER_PORT = 48879 +MAGIC_MESSAGE = "THIS IS THE ORIGINAL MESSAGE, PLEASE REASSEMBLE ME" + + +def print_header(f): + f.write("// SPDX-License-Identifier: GPL-2.0\n") + f.write("/* DO NOT EDIT -- this file is generated */\n") + f.write("\n") + f.write("#ifndef _IP_CHECK_DEFRAG_FRAGS_H\n") + f.write("#define _IP_CHECK_DEFRAG_FRAGS_H\n") + f.write("\n") + f.write("#include \n") + f.write("\n") + + +def print_frags(f, frags, v6): + for idx, frag in enumerate(frags): + # 10 bytes per line to keep width in check + chunks = [frag[i : i + 10] for i in range(0, len(frag), 10)] + chunks_fmted = [", ".join([str(hex(b)) for b in chunk]) for chunk in chunks] + suffix = "6" if v6 else "" + + f.write(f"static uint8_t frag{suffix}_{idx}[] = {{\n") + for chunk in chunks_fmted: + f.write(f"\t{chunk},\n") + f.write(f"}};\n") + + +def print_trailer(f): + f.write("\n") + f.write("#endif /* _IP_CHECK_DEFRAG_FRAGS_H */\n") + + +def main(f): + # srcip of 0 is filled in by IP_HDRINCL + sip = "0.0.0.0" + sip6 = VETH0_ADDR6 + dip = VETH1_ADDR + dip6 = VETH1_ADDR6 + sport = CLIENT_PORT + dport = SERVER_PORT + payload = MAGIC_MESSAGE.encode() + + # Disable UDPv4 checksums to keep code simpler + pkt = IP(src=sip,dst=dip) / UDP(sport=sport,dport=dport,chksum=0) / Raw(load=payload) + # UDPv6 requires a checksum + # Also pin the ipv6 fragment header ID, otherwise it's a random value + pkt6 = IPv6(src=sip6,dst=dip6) / IPv6ExtHdrFragment(id=0xBEEF) / UDP(sport=sport,dport=dport) / Raw(load=payload) + + frags = [f.build() for f in pkt.fragment(24)] + frags6 = [f.build() for f in fragment6(pkt6, 72)] + + print_header(f) + print_frags(f, frags, False) + print_frags(f, frags6, True) + print_trailer(f) + + +if __name__ == "__main__": + dir = os.path.dirname(os.path.realpath(__file__)) + header = f"{dir}/ip_check_defrag_frags.h" + with open(header, "w") as f: + main(f) diff --git a/tools/testing/selftests/bpf/ip_check_defrag_frags.h b/tools/testing/selftests/bpf/ip_check_defrag_frags.h new file mode 100644 index 000000000000..70ab7e9fa22b --- /dev/null +++ b/tools/testing/selftests/bpf/ip_check_defrag_frags.h @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 +/* DO NOT EDIT -- this file is generated */ + +#ifndef _IP_CHECK_DEFRAG_FRAGS_H +#define _IP_CHECK_DEFRAG_FRAGS_H + +#include + +static uint8_t frag_0[] = { + 0x45, 0x0, 0x0, 0x2c, 0x0, 0x1, 0x20, 0x0, 0x40, 0x11, + 0xac, 0xe8, 0x0, 0x0, 0x0, 0x0, 0xac, 0x10, 0x1, 0xc8, + 0xbe, 0xee, 0xbe, 0xef, 0x0, 0x3a, 0x0, 0x0, 0x54, 0x48, + 0x49, 0x53, 0x20, 0x49, 0x53, 0x20, 0x54, 0x48, 0x45, 0x20, + 0x4f, 0x52, 0x49, 0x47, +}; +static uint8_t frag_1[] = { + 0x45, 0x0, 0x0, 0x2c, 0x0, 0x1, 0x20, 0x3, 0x40, 0x11, + 0xac, 0xe5, 0x0, 0x0, 0x0, 0x0, 0xac, 0x10, 0x1, 0xc8, + 0x49, 0x4e, 0x41, 0x4c, 0x20, 0x4d, 0x45, 0x53, 0x53, 0x41, + 0x47, 0x45, 0x2c, 0x20, 0x50, 0x4c, 0x45, 0x41, 0x53, 0x45, + 0x20, 0x52, 0x45, 0x41, +}; +static uint8_t frag_2[] = { + 0x45, 0x0, 0x0, 0x1e, 0x0, 0x1, 0x0, 0x6, 0x40, 0x11, + 0xcc, 0xf0, 0x0, 0x0, 0x0, 0x0, 0xac, 0x10, 0x1, 0xc8, + 0x53, 0x53, 0x45, 0x4d, 0x42, 0x4c, 0x45, 0x20, 0x4d, 0x45, +}; +static uint8_t frag6_0[] = { + 0x60, 0x0, 0x0, 0x0, 0x0, 0x20, 0x2c, 0x40, 0xfc, 0x0, + 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x1, 0x0, 0xfc, 0x0, 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, + 0x11, 0x0, 0x0, 0x1, 0x0, 0x0, 0xbe, 0xef, 0xbe, 0xee, + 0xbe, 0xef, 0x0, 0x3a, 0xd0, 0xf8, 0x54, 0x48, 0x49, 0x53, + 0x20, 0x49, 0x53, 0x20, 0x54, 0x48, 0x45, 0x20, 0x4f, 0x52, + 0x49, 0x47, +}; +static uint8_t frag6_1[] = { + 0x60, 0x0, 0x0, 0x0, 0x0, 0x20, 0x2c, 0x40, 0xfc, 0x0, + 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x1, 0x0, 0xfc, 0x0, 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, + 0x11, 0x0, 0x0, 0x19, 0x0, 0x0, 0xbe, 0xef, 0x49, 0x4e, + 0x41, 0x4c, 0x20, 0x4d, 0x45, 0x53, 0x53, 0x41, 0x47, 0x45, + 0x2c, 0x20, 0x50, 0x4c, 0x45, 0x41, 0x53, 0x45, 0x20, 0x52, + 0x45, 0x41, +}; +static uint8_t frag6_2[] = { + 0x60, 0x0, 0x0, 0x0, 0x0, 0x12, 0x2c, 0x40, 0xfc, 0x0, + 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x1, 0x0, 0xfc, 0x0, 0x0, 0x0, 0x0, 0x0, + 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, + 0x11, 0x0, 0x0, 0x30, 0x0, 0x0, 0xbe, 0xef, 0x53, 0x53, + 0x45, 0x4d, 0x42, 0x4c, 0x45, 0x20, 0x4d, 0x45, +}; + +#endif /* _IP_CHECK_DEFRAG_FRAGS_H */ diff --git a/tools/testing/selftests/bpf/prog_tests/ip_check_defrag.c b/tools/testing/selftests/bpf/prog_tests/ip_check_defrag.c new file mode 100644 index 000000000000..57c814f5f6a7 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/ip_check_defrag.c @@ -0,0 +1,283 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include "ip_check_defrag.skel.h" +#include "ip_check_defrag_frags.h" + +/* + * This selftest spins up a client and an echo server, each in their own + * network namespace. The client will send a fragmented message to the server. + * The prog attached to the server will shoot down any fragments. Thus, if + * the server is able to correctly echo back the message to the client, we will + * have verified that netfilter is reassembling packets for us. + * + * Topology: + * ========= + * NS0 | NS1 + * | + * client | server + * ---------- | ---------- + * | veth0 | --------- | veth1 | + * ---------- peer ---------- + * | + * | with bpf + */ + +#define NS0 "defrag_ns0" +#define NS1 "defrag_ns1" +#define VETH0 "veth0" +#define VETH1 "veth1" +#define VETH0_ADDR "172.16.1.100" +#define VETH0_ADDR6 "fc00::100" +/* The following constants must stay in sync with `generate_udp_fragments.py` */ +#define VETH1_ADDR "172.16.1.200" +#define VETH1_ADDR6 "fc00::200" +#define CLIENT_PORT 48878 +#define SERVER_PORT 48879 +#define MAGIC_MESSAGE "THIS IS THE ORIGINAL MESSAGE, PLEASE REASSEMBLE ME" + +static int setup_topology(bool ipv6) +{ + bool up; + int i; + + SYS(fail, "ip netns add " NS0); + SYS(fail, "ip netns add " NS1); + SYS(fail, "ip link add " VETH0 " netns " NS0 " type veth peer name " VETH1 " netns " NS1); + if (ipv6) { + SYS(fail, "ip -6 -net " NS0 " addr add " VETH0_ADDR6 "/64 dev " VETH0 " nodad"); + SYS(fail, "ip -6 -net " NS1 " addr add " VETH1_ADDR6 "/64 dev " VETH1 " nodad"); + } else { + SYS(fail, "ip -net " NS0 " addr add " VETH0_ADDR "/24 dev " VETH0); + SYS(fail, "ip -net " NS1 " addr add " VETH1_ADDR "/24 dev " VETH1); + } + SYS(fail, "ip -net " NS0 " link set dev " VETH0 " up"); + SYS(fail, "ip -net " NS1 " link set dev " VETH1 " up"); + + /* Wait for up to 5s for links to come up */ + for (i = 0; i < 5; ++i) { + if (ipv6) + up = !system("ip netns exec " NS0 " ping -6 -c 1 -W 1 " VETH1_ADDR6 " &>/dev/null"); + else + up = !system("ip netns exec " NS0 " ping -c 1 -W 1 " VETH1_ADDR " &>/dev/null"); + + if (up) + break; + } + + return 0; +fail: + return -1; +} + +static void cleanup_topology(void) +{ + SYS_NOFAIL("test -f /var/run/netns/" NS0 " && ip netns delete " NS0); + SYS_NOFAIL("test -f /var/run/netns/" NS1 " && ip netns delete " NS1); +} + +static int attach(struct ip_check_defrag *skel, bool ipv6) +{ + LIBBPF_OPTS(bpf_netfilter_opts, opts, + .pf = ipv6 ? NFPROTO_IPV6 : NFPROTO_IPV4, + .priority = 42, + .flags = BPF_F_NETFILTER_IP_DEFRAG); + struct nstoken *nstoken; + int err = -1; + + nstoken = open_netns(NS1); + + skel->links.defrag = bpf_program__attach_netfilter(skel->progs.defrag, &opts); + if (!ASSERT_OK_PTR(skel->links.defrag, "program attach")) + goto out; + + err = 0; +out: + close_netns(nstoken); + return err; +} + +static int send_frags(int client) +{ + struct sockaddr_storage saddr; + struct sockaddr *saddr_p; + socklen_t saddr_len; + int err; + + saddr_p = (struct sockaddr *)&saddr; + err = make_sockaddr(AF_INET, VETH1_ADDR, SERVER_PORT, &saddr, &saddr_len); + if (!ASSERT_OK(err, "make_sockaddr")) + return -1; + + err = sendto(client, frag_0, sizeof(frag_0), 0, saddr_p, saddr_len); + if (!ASSERT_GE(err, 0, "sendto frag_0")) + return -1; + + err = sendto(client, frag_1, sizeof(frag_1), 0, saddr_p, saddr_len); + if (!ASSERT_GE(err, 0, "sendto frag_1")) + return -1; + + err = sendto(client, frag_2, sizeof(frag_2), 0, saddr_p, saddr_len); + if (!ASSERT_GE(err, 0, "sendto frag_2")) + return -1; + + return 0; +} + +static int send_frags6(int client) +{ + struct sockaddr_storage saddr; + struct sockaddr *saddr_p; + socklen_t saddr_len; + int err; + + saddr_p = (struct sockaddr *)&saddr; + /* Port needs to be set to 0 for raw ipv6 socket for some reason */ + err = make_sockaddr(AF_INET6, VETH1_ADDR6, 0, &saddr, &saddr_len); + if (!ASSERT_OK(err, "make_sockaddr")) + return -1; + + err = sendto(client, frag6_0, sizeof(frag6_0), 0, saddr_p, saddr_len); + if (!ASSERT_GE(err, 0, "sendto frag6_0")) + return -1; + + err = sendto(client, frag6_1, sizeof(frag6_1), 0, saddr_p, saddr_len); + if (!ASSERT_GE(err, 0, "sendto frag6_1")) + return -1; + + err = sendto(client, frag6_2, sizeof(frag6_2), 0, saddr_p, saddr_len); + if (!ASSERT_GE(err, 0, "sendto frag6_2")) + return -1; + + return 0; +} + +void test_bpf_ip_check_defrag_ok(bool ipv6) +{ + struct network_helper_opts rx_opts = { + .timeout_ms = 1000, + .noconnect = true, + }; + struct network_helper_opts tx_ops = { + .timeout_ms = 1000, + .type = SOCK_RAW, + .proto = IPPROTO_RAW, + .noconnect = true, + }; + struct sockaddr_storage caddr; + struct ip_check_defrag *skel; + struct nstoken *nstoken; + int client_tx_fd = -1; + int client_rx_fd = -1; + socklen_t caddr_len; + int srv_fd = -1; + char buf[1024]; + int len, err; + + skel = ip_check_defrag__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + if (!ASSERT_OK(setup_topology(ipv6), "setup_topology")) + goto out; + + if (!ASSERT_OK(attach(skel, ipv6), "attach")) + goto out; + + /* Start server in ns1 */ + nstoken = open_netns(NS1); + if (!ASSERT_OK_PTR(nstoken, "setns ns1")) + goto out; + srv_fd = start_server(ipv6 ? AF_INET6 : AF_INET, SOCK_DGRAM, NULL, SERVER_PORT, 0); + close_netns(nstoken); + if (!ASSERT_GE(srv_fd, 0, "start_server")) + goto out; + + /* Open tx raw socket in ns0 */ + nstoken = open_netns(NS0); + if (!ASSERT_OK_PTR(nstoken, "setns ns0")) + goto out; + client_tx_fd = connect_to_fd_opts(srv_fd, &tx_ops); + close_netns(nstoken); + if (!ASSERT_GE(client_tx_fd, 0, "connect_to_fd_opts")) + goto out; + + /* Open rx socket in ns0 */ + nstoken = open_netns(NS0); + if (!ASSERT_OK_PTR(nstoken, "setns ns0")) + goto out; + client_rx_fd = connect_to_fd_opts(srv_fd, &rx_opts); + close_netns(nstoken); + if (!ASSERT_GE(client_rx_fd, 0, "connect_to_fd_opts")) + goto out; + + /* Bind rx socket to a premeditated port */ + memset(&caddr, 0, sizeof(caddr)); + nstoken = open_netns(NS0); + if (!ASSERT_OK_PTR(nstoken, "setns ns0")) + goto out; + if (ipv6) { + struct sockaddr_in6 *c = (struct sockaddr_in6 *)&caddr; + + c->sin6_family = AF_INET6; + inet_pton(AF_INET6, VETH0_ADDR6, &c->sin6_addr); + c->sin6_port = htons(CLIENT_PORT); + err = bind(client_rx_fd, (struct sockaddr *)c, sizeof(*c)); + } else { + struct sockaddr_in *c = (struct sockaddr_in *)&caddr; + + c->sin_family = AF_INET; + inet_pton(AF_INET, VETH0_ADDR, &c->sin_addr); + c->sin_port = htons(CLIENT_PORT); + err = bind(client_rx_fd, (struct sockaddr *)c, sizeof(*c)); + } + close_netns(nstoken); + if (!ASSERT_OK(err, "bind")) + goto out; + + /* Send message in fragments */ + if (ipv6) { + if (!ASSERT_OK(send_frags6(client_tx_fd), "send_frags6")) + goto out; + } else { + if (!ASSERT_OK(send_frags(client_tx_fd), "send_frags")) + goto out; + } + + if (!ASSERT_EQ(skel->bss->shootdowns, 0, "shootdowns")) + goto out; + + /* Receive reassembled msg on server and echo back to client */ + caddr_len = sizeof(caddr); + len = recvfrom(srv_fd, buf, sizeof(buf), 0, (struct sockaddr *)&caddr, &caddr_len); + if (!ASSERT_GE(len, 0, "server recvfrom")) + goto out; + len = sendto(srv_fd, buf, len, 0, (struct sockaddr *)&caddr, caddr_len); + if (!ASSERT_GE(len, 0, "server sendto")) + goto out; + + /* Expect reassembed message to be echoed back */ + len = recvfrom(client_rx_fd, buf, sizeof(buf), 0, NULL, NULL); + if (!ASSERT_EQ(len, sizeof(MAGIC_MESSAGE) - 1, "client short read")) + goto out; + +out: + if (client_rx_fd != -1) + close(client_rx_fd); + if (client_tx_fd != -1) + close(client_tx_fd); + if (srv_fd != -1) + close(srv_fd); + cleanup_topology(); + ip_check_defrag__destroy(skel); +} + +void test_bpf_ip_check_defrag(void) +{ + if (test__start_subtest("v4")) + test_bpf_ip_check_defrag_ok(false); + if (test__start_subtest("v6")) + test_bpf_ip_check_defrag_ok(true); +} diff --git a/tools/testing/selftests/bpf/progs/ip_check_defrag.c b/tools/testing/selftests/bpf/progs/ip_check_defrag.c new file mode 100644 index 000000000000..1c2b6c1616b0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/ip_check_defrag.c @@ -0,0 +1,104 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include "vmlinux.h" +#include +#include +#include "bpf_tracing_net.h" + +#define NF_DROP 0 +#define NF_ACCEPT 1 +#define ETH_P_IP 0x0800 +#define ETH_P_IPV6 0x86DD +#define IP_MF 0x2000 +#define IP_OFFSET 0x1FFF +#define NEXTHDR_FRAGMENT 44 + +extern int bpf_dynptr_from_skb(struct sk_buff *skb, __u64 flags, + struct bpf_dynptr *ptr__uninit) __ksym; +extern void *bpf_dynptr_slice(const struct bpf_dynptr *ptr, uint32_t offset, + void *buffer, uint32_t buffer__sz) __ksym; + +volatile int shootdowns = 0; + +static bool is_frag_v4(struct iphdr *iph) +{ + int offset; + int flags; + + offset = bpf_ntohs(iph->frag_off); + flags = offset & ~IP_OFFSET; + offset &= IP_OFFSET; + offset <<= 3; + + return (flags & IP_MF) || offset; +} + +static bool is_frag_v6(struct ipv6hdr *ip6h) +{ + /* Simplifying assumption that there are no extension headers + * between fixed header and fragmentation header. This assumption + * is only valid in this test case. It saves us the hassle of + * searching all potential extension headers. + */ + return ip6h->nexthdr == NEXTHDR_FRAGMENT; +} + +static int handle_v4(struct sk_buff *skb) +{ + struct bpf_dynptr ptr; + u8 iph_buf[20] = {}; + struct iphdr *iph; + + if (bpf_dynptr_from_skb(skb, 0, &ptr)) + return NF_DROP; + + iph = bpf_dynptr_slice(&ptr, 0, iph_buf, sizeof(iph_buf)); + if (!iph) + return NF_DROP; + + /* Shootdown any frags */ + if (is_frag_v4(iph)) { + shootdowns++; + return NF_DROP; + } + + return NF_ACCEPT; +} + +static int handle_v6(struct sk_buff *skb) +{ + struct bpf_dynptr ptr; + struct ipv6hdr *ip6h; + u8 ip6h_buf[40] = {}; + + if (bpf_dynptr_from_skb(skb, 0, &ptr)) + return NF_DROP; + + ip6h = bpf_dynptr_slice(&ptr, 0, ip6h_buf, sizeof(ip6h_buf)); + if (!ip6h) + return NF_DROP; + + /* Shootdown any frags */ + if (is_frag_v6(ip6h)) { + shootdowns++; + return NF_DROP; + } + + return NF_ACCEPT; +} + +SEC("netfilter") +int defrag(struct bpf_nf_ctx *ctx) +{ + struct sk_buff *skb = ctx->skb; + + switch (bpf_ntohs(skb->protocol)) { + case ETH_P_IP: + return handle_v4(skb); + case ETH_P_IPV6: + return handle_v6(skb); + default: + return NF_ACCEPT; + } +} + +char _license[] SEC("license") = "GPL";