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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A94BC433FE for ; Thu, 4 Nov 2021 01:08:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7195E611C4 for ; Thu, 4 Nov 2021 01:08:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232286AbhKDBK4 (ORCPT ); Wed, 3 Nov 2021 21:10:56 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:27173 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230233AbhKDBKz (ORCPT ); Wed, 3 Nov 2021 21:10:55 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.55]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Hl57l6HbFzTgHJ; Thu, 4 Nov 2021 09:06:43 +0800 (CST) Received: from dggpeml500011.china.huawei.com (7.185.36.84) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Thu, 4 Nov 2021 09:08:13 +0800 Received: from localhost.localdomain (10.175.101.6) by dggpeml500011.china.huawei.com (7.185.36.84) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Thu, 4 Nov 2021 09:08:12 +0800 From: Di Zhu To: , , , , , , , , , CC: , , Subject: [PATCH bpf-next v5 1/2] bpf: support BPF_PROG_QUERY for progs attached to sockmap Date: Thu, 4 Nov 2021 09:07:44 +0800 Message-ID: <20211104010745.1177032-1-zhudi2@huawei.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500011.china.huawei.com (7.185.36.84) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Right now there is no way to query whether BPF programs are attached to a sockmap or not. we can use the standard interface in libbpf to query, such as: bpf_prog_query(mapFd, BPF_SK_SKB_STREAM_PARSER, 0, NULL, ...); the mapFd is the fd of sockmap. Signed-off-by: Di Zhu --- /* v2 */ - John Fastabend - add selftest code /* v3 */ - avoid sleeping caused by copy_to_user() in rcu critical zone /* v4 */ - Alexei Starovoitov -split into two patches, one for core code and one for selftest. /* v5 */ - Yonghong Song -Some naming and formatting changes --- include/linux/bpf.h | 9 ++++++ kernel/bpf/syscall.c | 5 +++ net/core/sock_map.c | 74 +++++++++++++++++++++++++++++++++++++++----- 3 files changed, 81 insertions(+), 7 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index d604c8251d88..235ea7fc5fd8 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1961,6 +1961,9 @@ int bpf_prog_test_run_syscall(struct bpf_prog *prog, int sock_map_get_from_fd(const union bpf_attr *attr, struct bpf_prog *prog); int sock_map_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype); int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value, u64 flags); +int sock_map_bpf_prog_query(const union bpf_attr *attr, + union bpf_attr __user *uattr); + void sock_map_unhash(struct sock *sk); void sock_map_close(struct sock *sk, long timeout); #else @@ -2014,6 +2017,12 @@ static inline int sock_map_update_elem_sys(struct bpf_map *map, void *key, void { return -EOPNOTSUPP; } + +static inline int sock_map_bpf_prog_query(const union bpf_attr *attr, + union bpf_attr __user *uattr) +{ + return -EINVAL; +} #endif /* CONFIG_BPF_SYSCALL */ #endif /* CONFIG_NET && CONFIG_BPF_SYSCALL */ diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 4e50c0bfdb7d..748102c3e0c9 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3275,6 +3275,11 @@ static int bpf_prog_query(const union bpf_attr *attr, case BPF_FLOW_DISSECTOR: case BPF_SK_LOOKUP: return netns_bpf_prog_query(attr, uattr); + case BPF_SK_SKB_STREAM_PARSER: + case BPF_SK_SKB_STREAM_VERDICT: + case BPF_SK_MSG_VERDICT: + case BPF_SK_SKB_VERDICT: + return sock_map_bpf_prog_query(attr, uattr); default: return -EINVAL; } diff --git a/net/core/sock_map.c b/net/core/sock_map.c index e252b8ec2b85..0320d27550fe 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -1412,38 +1412,50 @@ static struct sk_psock_progs *sock_map_progs(struct bpf_map *map) return NULL; } -static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, - struct bpf_prog *old, u32 which) +static int sock_map_prog_lookup(struct bpf_map *map, struct bpf_prog ***pprog, + u32 which) { struct sk_psock_progs *progs = sock_map_progs(map); - struct bpf_prog **pprog; if (!progs) return -EOPNOTSUPP; switch (which) { case BPF_SK_MSG_VERDICT: - pprog = &progs->msg_parser; + *pprog = &progs->msg_parser; break; #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) case BPF_SK_SKB_STREAM_PARSER: - pprog = &progs->stream_parser; + *pprog = &progs->stream_parser; break; #endif case BPF_SK_SKB_STREAM_VERDICT: if (progs->skb_verdict) return -EBUSY; - pprog = &progs->stream_verdict; + *pprog = &progs->stream_verdict; break; case BPF_SK_SKB_VERDICT: if (progs->stream_verdict) return -EBUSY; - pprog = &progs->skb_verdict; + *pprog = &progs->skb_verdict; break; default: return -EOPNOTSUPP; } + return 0; +} + +static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, + struct bpf_prog *old, u32 which) +{ + struct bpf_prog **pprog; + int ret; + + ret = sock_map_prog_lookup(map, &pprog, which); + if (ret) + return ret; + if (old) return psock_replace_prog(pprog, prog, old); @@ -1451,6 +1463,54 @@ static int sock_map_prog_update(struct bpf_map *map, struct bpf_prog *prog, return 0; } +int sock_map_bpf_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_cnt = 0, flags = 0, ufd = attr->target_fd; + struct bpf_prog **pprog; + struct bpf_prog *prog; + struct bpf_map *map; + struct fd f; + u32 id = 0; + int ret; + + if (attr->query.query_flags) + return -EINVAL; + + f = fdget(ufd); + map = __bpf_map_get(f); + if (IS_ERR(map)) + return PTR_ERR(map); + + rcu_read_lock(); + + ret = sock_map_prog_lookup(map, &pprog, attr->query.attach_type); + if (ret) + goto end; + + prog = *pprog; + prog_cnt = (!prog) ? 0 : 1; + + if (!attr->query.prog_cnt || !prog_ids || !prog_cnt) + goto end; + + id = prog->aux->id; + if (id == 0) + prog_cnt = 0; + +end: + rcu_read_unlock(); + + if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)) || + (id != 0 && copy_to_user(prog_ids, &id, sizeof(u32))) || + copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt))) + ret = -EFAULT; + + fdput(f); + return ret; +} + static void sock_map_unlink(struct sock *sk, struct sk_psock_link *link) { switch (link->map->map_type) { -- 2.27.0