From patchwork Wed Apr 5 16:11:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 1765623 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=netfilter-devel-owner@vger.kernel.org; receiver=) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4Ps8lh6xdKz1yY8 for ; Thu, 6 Apr 2023 02:12:00 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233752AbjDEQL7 (ORCPT ); Wed, 5 Apr 2023 12:11:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232501AbjDEQLx (ORCPT ); Wed, 5 Apr 2023 12:11:53 -0400 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:237:300::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4759010F1; Wed, 5 Apr 2023 09:11:42 -0700 (PDT) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1pk5jY-0007lm-Oo; Wed, 05 Apr 2023 18:11:40 +0200 From: Florian Westphal To: Cc: netfilter-devel@vger.kernel.org, bpf@vger.kernel.org, dxu@dxuuu.xyz, qde@naccy.de, Florian Westphal Subject: [PATCH bpf-next 3/6] netfilter: nfnetlink hook: dump bpf prog id Date: Wed, 5 Apr 2023 18:11:13 +0200 Message-Id: <20230405161116.13565-4-fw@strlen.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230405161116.13565-1-fw@strlen.de> References: <20230405161116.13565-1-fw@strlen.de> MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_MED,SPF_HELO_PASS,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org This allows userspace ("nft list hooks") to show which bpf program is attached to which hook. Without this, user only knows bpf prog is attached at prio x, y, z at INPUT and FORWARD, but can't tell which program is where. Signed-off-by: Florian Westphal --- include/uapi/linux/netfilter/nfnetlink_hook.h | 20 ++++- net/netfilter/nfnetlink_hook.c | 81 ++++++++++++++++--- 2 files changed, 87 insertions(+), 14 deletions(-) diff --git a/include/uapi/linux/netfilter/nfnetlink_hook.h b/include/uapi/linux/netfilter/nfnetlink_hook.h index bbcd285b22e1..63b7dbddf0b1 100644 --- a/include/uapi/linux/netfilter/nfnetlink_hook.h +++ b/include/uapi/linux/netfilter/nfnetlink_hook.h @@ -32,8 +32,12 @@ enum nfnl_hook_attributes { /** * enum nfnl_hook_chain_info_attributes - chain description * - * NFNLA_HOOK_INFO_DESC: nft chain and table name (enum nft_table_attributes) (NLA_NESTED) + * NFNLA_HOOK_INFO_DESC: nft chain and table name (NLA_NESTED) * NFNLA_HOOK_INFO_TYPE: chain type (enum nfnl_hook_chaintype) (NLA_U32) + * + * NFNLA_HOOK_INFO_DESC depends on NFNLA_HOOK_INFO_TYPE value: + * NFNL_HOOK_TYPE_NFTABLES: enum nft_table_attributes + * NFNL_HOOK_TYPE_BPF: enum nfnl_hook_bpf_info_attributes */ enum nfnl_hook_chain_info_attributes { NFNLA_HOOK_INFO_UNSPEC, @@ -56,9 +60,23 @@ enum nfnl_hook_chain_desc_attributes { * enum nfnl_hook_chaintype - chain type * * @NFNL_HOOK_TYPE_NFTABLES nf_tables base chain + * @NFNL_HOOK_TYPE_BPF bpf program */ enum nfnl_hook_chaintype { NFNL_HOOK_TYPE_NFTABLES = 0x1, + NFNL_HOOK_TYPE_BPF, +}; + +/** + * enum nfnl_hook_bpf_info_attributes - bpf prog description + * + * NFNLA_BPF_INFO_ID: bpf program id (NLA_U32) + */ +enum nfnl_hook_bpf_attributes { + NFNLA_HOOK_BPF_UNSPEC, + NFNLA_HOOK_BPF_ID, + __NFNLA_HOOK_BPF_MAX, }; +#define NFNLA_HOOK_BPF_MAX (__NFNLA_HOOK_BPF_MAX - 1) #endif /* _NFNL_HOOK_H */ diff --git a/net/netfilter/nfnetlink_hook.c b/net/netfilter/nfnetlink_hook.c index 8120aadf6a0f..ade8ee1988b1 100644 --- a/net/netfilter/nfnetlink_hook.c +++ b/net/netfilter/nfnetlink_hook.c @@ -5,6 +5,7 @@ * Author: Florian Westphal */ +#include #include #include #include @@ -57,35 +58,76 @@ struct nfnl_dump_hook_data { u8 hook; }; +static struct nlattr *nfnl_start_info_type(struct sk_buff *nlskb, enum nfnl_hook_chaintype t) +{ + struct nlattr *nest = nla_nest_start(nlskb, NFNLA_HOOK_CHAIN_INFO); + int ret; + + if (!nest) + return NULL; + + ret = nla_put_be32(nlskb, NFNLA_HOOK_INFO_TYPE, htonl(t)); + if (ret == 0) + return nest; + + nla_nest_cancel(nlskb, nest); + return NULL; +} + +static int nfnl_hook_put_bpf_prog_info(struct sk_buff *nlskb, + const struct nfnl_dump_hook_data *ctx, + unsigned int seq, + const struct bpf_prog *prog) +{ + struct nlattr *nest, *nest2; + int ret; + + if (!IS_ENABLED(CONFIG_NETFILTER_BPF_LINK)) + return 0; + + if (WARN_ON_ONCE(!prog)) + return 0; + + nest = nfnl_start_info_type(nlskb, NFNL_HOOK_TYPE_BPF); + if (!nest) + return -EMSGSIZE; + + nest2 = nla_nest_start(nlskb, NFNLA_HOOK_INFO_DESC); + if (!nest2) + goto cancel_nest; + + ret = nla_put_be32(nlskb, NFNLA_HOOK_BPF_ID, htonl(prog->aux->id)); + if (ret) + goto cancel_nest; + + nla_nest_end(nlskb, nest2); + nla_nest_end(nlskb, nest); + return 0; + +cancel_nest: + nla_nest_cancel(nlskb, nest); + return -EMSGSIZE; +} + static int nfnl_hook_put_nft_chain_info(struct sk_buff *nlskb, const struct nfnl_dump_hook_data *ctx, unsigned int seq, - const struct nf_hook_ops *ops) + struct nft_chain *chain) { struct net *net = sock_net(nlskb->sk); struct nlattr *nest, *nest2; - struct nft_chain *chain; int ret = 0; - if (ops->hook_ops_type != NF_HOOK_OP_NF_TABLES) - return 0; - - chain = ops->priv; if (WARN_ON_ONCE(!chain)) return 0; if (!nft_is_active(net, chain)) return 0; - nest = nla_nest_start(nlskb, NFNLA_HOOK_CHAIN_INFO); + nest = nfnl_start_info_type(nlskb, NFNL_HOOK_TYPE_NFTABLES); if (!nest) return -EMSGSIZE; - ret = nla_put_be32(nlskb, NFNLA_HOOK_INFO_TYPE, - htonl(NFNL_HOOK_TYPE_NFTABLES)); - if (ret) - goto cancel_nest; - nest2 = nla_nest_start(nlskb, NFNLA_HOOK_INFO_DESC); if (!nest2) goto cancel_nest; @@ -171,7 +213,20 @@ static int nfnl_hook_dump_one(struct sk_buff *nlskb, if (ret) goto nla_put_failure; - ret = nfnl_hook_put_nft_chain_info(nlskb, ctx, seq, ops); + switch (ops->hook_ops_type) { + case NF_HOOK_OP_NF_TABLES: + ret = nfnl_hook_put_nft_chain_info(nlskb, ctx, seq, ops->priv); + break; + case NF_HOOK_OP_BPF: + ret = nfnl_hook_put_bpf_prog_info(nlskb, ctx, seq, ops->priv); + break; + case NF_HOOK_OP_UNDEFINED: + break; + default: + WARN_ON_ONCE(1); + break; + } + if (ret) goto nla_put_failure;