From patchwork Thu Apr 25 21:37:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 1091092 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="eqv1h9xY"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44qrBR4c0Nz9s6w for ; Fri, 26 Apr 2019 07:37:35 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731280AbfDYVh2 (ORCPT ); Thu, 25 Apr 2019 17:37:28 -0400 Received: from mail-pg1-f202.google.com ([209.85.215.202]:56019 "EHLO mail-pg1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731255AbfDYVh1 (ORCPT ); Thu, 25 Apr 2019 17:37:27 -0400 Received: by mail-pg1-f202.google.com with SMTP id a8so538788pgq.22 for ; Thu, 25 Apr 2019 14:37:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=UAjPdvqWg5Vcpy6WjhUujOLut6fOmfM18+jDIqTl8yU=; b=eqv1h9xYKqx2Mt2qm6D6gIVR9ld1O0wDmWr4VM1uIynlztZbuPt+8YaPYkp8m5887e nMexZyQLyNgPgCkalsCjTwDdccazQsozzRA/Doc8jgsaIqQmbU41gWwb02MaE95QfEWN T5iuXbOFMn0eQ6Z0xcRcjP2DSZx3v7Ag+gfoOuLGHM2bZ4Bp1f6m6GX785ak3/NYWQt+ qLDqM20oqfeVmyoKyJprc12P59YMCh8jMRekTCneLPmeWpe/smw6u6XUJX2Vg7KeZD/+ UFtyULlkotN7FcKvv+xVRXdHwF5pRFfIwfQtg7lwdtTqrdv7AUhQYVNEQBdZOUzAZC0z V0mw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=UAjPdvqWg5Vcpy6WjhUujOLut6fOmfM18+jDIqTl8yU=; b=m+/yPCaiA/K2Kd4vDeLHguK61hua6ASZaIeC2wm1Y9rjqhHcReZRXibG5tMh4Ooir/ MlUWSoQt/PfxdDMY75y9/VjQq/nS60S/hnA1A3HQO7fSadx7Jvjj7L5cf7//x8zylwaL wBOpPOJZwYMlBSa1pVIkg5u/eN+zRZOejmZjD494D/43ILqOfowBJXK+7dnPp5jbGzpR F3efHbHGNCdU0t1R4X4OmXSc23ezUyAG0566C3fpX6KkmgVQyhojthe4Nc3oPiH0k4n5 FtPVHgJyGMPxog3+xvz7jv7hpRlL0is7bpRSU/HbsJ3vVqBiFHbVNkvs8wwgDJDV/lhw 2NhA== X-Gm-Message-State: APjAAAVfO6etgew4xXmE7RV20D9L94nVPXhZEnEmX9MIYlhNjaKra2gX +3lhErS6Q4gFzBpgSxdTXz2N75o= X-Google-Smtp-Source: APXvYqxP6GJBeiLkNqCfAvmX5JUUDmol9S8qtksSnCsECoAI8fFcavhIa9IwVvU7cWcY1u4FKTH2nBg= X-Received: by 2002:a63:f26:: with SMTP id e38mr40563801pgl.290.1556228247069; Thu, 25 Apr 2019 14:37:27 -0700 (PDT) Date: Thu, 25 Apr 2019 14:37:23 -0700 Message-Id: <20190425213724.25056-1-sdf@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.21.0.593.g511ec345e18-goog Subject: [PATCH bpf-next v5 1/2] bpf: support BPF_PROG_QUERY for BPF_FLOW_DISSECTOR attach_type From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, Stanislav Fomichev , Jann Horn Sender: bpf-owner@vger.kernel.org Precedence: bulk List-Id: netdev.vger.kernel.org target_fd is target namespace. If there is a flow dissector BPF program attached to that namespace, its (single) id is returned. v5: * drop net ref right after rcu unlock (Daniel Borkmann) v4: * add missing put_net (Jann Horn) v3: * add missing inline to skb_flow_dissector_prog_query static def (kbuild test robot ) v2: * don't sleep in rcu critical section (Jakub Kicinski) * check input prog_cnt (exit early) Cc: Jann Horn Signed-off-by: Stanislav Fomichev --- include/linux/skbuff.h | 8 ++++++++ kernel/bpf/syscall.c | 2 ++ net/core/flow_dissector.c | 39 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 49 insertions(+) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 998256c2820b..6d58fa8a65fd 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1258,11 +1258,19 @@ void skb_flow_dissector_init(struct flow_dissector *flow_dissector, unsigned int key_count); #ifdef CONFIG_NET +int skb_flow_dissector_prog_query(const union bpf_attr *attr, + union bpf_attr __user *uattr); int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog); int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr); #else +static inline int skb_flow_dissector_prog_query(const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + return -EOPNOTSUPP; +} + static inline int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog) { diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 92c9b8a32b50..b0de49598341 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2009,6 +2009,8 @@ static int bpf_prog_query(const union bpf_attr *attr, break; case BPF_LIRC_MODE2: return lirc_prog_query(attr, uattr); + case BPF_FLOW_DISSECTOR: + return skb_flow_dissector_prog_query(attr, uattr); default: return -EINVAL; } diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index fac712cee9d5..9ca784c592ac 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -65,6 +65,45 @@ void skb_flow_dissector_init(struct flow_dissector *flow_dissector, } EXPORT_SYMBOL(skb_flow_dissector_init); +int skb_flow_dissector_prog_query(const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids); + u32 prog_id, prog_cnt = 0, flags = 0; + struct bpf_prog *attached; + struct net *net; + + if (attr->query.query_flags) + return -EINVAL; + + net = get_net_ns_by_fd(attr->query.target_fd); + if (IS_ERR(net)) + return PTR_ERR(net); + + rcu_read_lock(); + attached = rcu_dereference(net->flow_dissector_prog); + if (attached) { + prog_cnt = 1; + prog_id = attached->aux->id; + } + rcu_read_unlock(); + + put_net(net); + + if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags))) + return -EFAULT; + if (copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt))) + return -EFAULT; + + if (!attr->query.prog_cnt || !prog_ids || !prog_cnt) + return 0; + + if (copy_to_user(prog_ids, &prog_id, sizeof(u32))) + return -EFAULT; + + return 0; +} + int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr, struct bpf_prog *prog) {