From patchwork Fri Mar 27 15:58:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Borkmann X-Patchwork-Id: 221714 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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 A3242C2D0E5 for ; Fri, 27 Mar 2020 15:59:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84C3A2072F for ; Fri, 27 Mar 2020 15:59:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727769AbgC0P70 (ORCPT ); Fri, 27 Mar 2020 11:59:26 -0400 Received: from www62.your-server.de ([213.133.104.62]:50934 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727585AbgC0P7P (ORCPT ); Fri, 27 Mar 2020 11:59:15 -0400 Received: from 98.186.195.178.dynamic.wline.res.cust.swisscom.ch ([178.195.186.98] helo=localhost) by www62.your-server.de with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1jHrO5-0007nK-Il; Fri, 27 Mar 2020 16:59:13 +0100 From: Daniel Borkmann To: alexei.starovoitov@gmail.com Cc: m@lambda.lt, joe@wand.net.nz, bpf@vger.kernel.org, netdev@vger.kernel.org, Daniel Borkmann Subject: [PATCH bpf-next 4/7] bpf: allow to retrieve cgroup v1 classid from v2 hooks Date: Fri, 27 Mar 2020 16:58:53 +0100 Message-Id: <555e1c69db7376c0947007b4951c260e1074efc3.1585323121.git.daniel@iogearbox.net> X-Mailer: git-send-email 2.21.0 In-Reply-To: References: MIME-Version: 1.0 X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.102.2/25764/Fri Mar 27 14:11:26 2020) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Today, Kubernetes is still operating on cgroups v1, however, it is possible to retrieve the task's classid based on 'current' out of connect(), sendmsg(), recvmsg() and bind-related hooks for orchestrators which attach to the root cgroup v2 hook in a mixed env like in case of Cilium, for example, in order to then correlate certain pod traffic and use it as part of the key for BPF map lookups. Signed-off-by: Daniel Borkmann --- include/net/cls_cgroup.h | 7 ++++++- net/core/filter.c | 21 +++++++++++++++++++++ 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/include/net/cls_cgroup.h b/include/net/cls_cgroup.h index 4295de3e6a4b..7e78e7d6f015 100644 --- a/include/net/cls_cgroup.h +++ b/include/net/cls_cgroup.h @@ -45,9 +45,14 @@ static inline void sock_update_classid(struct sock_cgroup_data *skcd) sock_cgroup_set_classid(skcd, classid); } +static inline u32 __task_get_classid(struct task_struct *task) +{ + return task_cls_state(task)->classid; +} + static inline u32 task_get_classid(const struct sk_buff *skb) { - u32 classid = task_cls_state(current)->classid; + u32 classid = __task_get_classid(current); /* Due to the nature of the classifier it is required to ignore all * packets originating from softirq context as accessing `current' diff --git a/net/core/filter.c b/net/core/filter.c index e249a499cbe5..3083c7746ee0 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2642,6 +2642,19 @@ static const struct bpf_func_proto bpf_msg_pop_data_proto = { .arg4_type = ARG_ANYTHING, }; +#ifdef CONFIG_CGROUP_NET_CLASSID +BPF_CALL_0(bpf_get_cgroup_classid_curr) +{ + return __task_get_classid(current); +} + +static const struct bpf_func_proto bpf_get_cgroup_classid_curr_proto = { + .func = bpf_get_cgroup_classid_curr, + .gpl_only = false, + .ret_type = RET_INTEGER, +}; +#endif + BPF_CALL_1(bpf_get_cgroup_classid, const struct sk_buff *, skb) { return task_get_classid(skb); @@ -6005,6 +6018,10 @@ sock_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_netns_cookie_sock_proto; case BPF_FUNC_perf_event_output: return &bpf_event_output_data_proto; +#ifdef CONFIG_CGROUP_NET_CLASSID + case BPF_FUNC_get_cgroup_classid: + return &bpf_get_cgroup_classid_curr_proto; +#endif default: return bpf_base_func_proto(func_id); } @@ -6035,6 +6052,10 @@ sock_addr_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_local_storage_proto; case BPF_FUNC_perf_event_output: return &bpf_event_output_data_proto; +#ifdef CONFIG_CGROUP_NET_CLASSID + case BPF_FUNC_get_cgroup_classid: + return &bpf_get_cgroup_classid_curr_proto; +#endif #ifdef CONFIG_INET case BPF_FUNC_sk_lookup_tcp: return &bpf_sock_addr_sk_lookup_tcp_proto;