From patchwork Wed Aug 19 09:24:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenz Bauer X-Patchwork-Id: 1347642 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=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=cloudflare.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=cloudflare.com header.i=@cloudflare.com header.a=rsa-sha256 header.s=google header.b=Rfhvso3N; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BWjQ25Y6Mz9sTW for ; Wed, 19 Aug 2020 19:38:18 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727113AbgHSJiP (ORCPT ); Wed, 19 Aug 2020 05:38:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727772AbgHSJhz (ORCPT ); Wed, 19 Aug 2020 05:37:55 -0400 Received: from mail-wm1-x342.google.com (mail-wm1-x342.google.com [IPv6:2a00:1450:4864:20::342]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79C18C061757 for ; Wed, 19 Aug 2020 02:37:53 -0700 (PDT) Received: by mail-wm1-x342.google.com with SMTP id x5so1402704wmi.2 for ; Wed, 19 Aug 2020 02:37:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Ue3HR4wod0zNE7CrQUQ6Ehp/OR8t+fJlFQGIBrnJpsQ=; b=Rfhvso3NOUQY38ai/WyXwxP2YDeNCMIDRXmyKlgbLBMHkJMlOQqpezKRmyPSc8yE5l AByj7j2lupGigIB1Sbv2NCH5gmhw9szstkADVs3B8XOOH4xvAL/1WJbu6Y1Q492zCM3C Kga7QxNepaIpc5TzhWJpd+NO3oPe+g4sBseQo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Ue3HR4wod0zNE7CrQUQ6Ehp/OR8t+fJlFQGIBrnJpsQ=; b=pGPfaJPEZDxe6yJ7ju2hctie28nVuOlhaSafl6w8gpaoy+fZCeeOx6kt0heiI75+NY MDE01hIuygj9D7Pd+e/ZFybgufNaOdTj3c7bvWvUrhcKhTUkOT/n1nsZEH+sHcNpHq8W o7ihdqujyfGWwvEwLAv6zp3sAGWPhlTakvo4SQkpwAhzC0Cn0G2rBD4TFcU41HzGhUw2 IkTjR+qIEeiNQxWNeNjRJO9ezhVnNG4kagDurdGj//5ZqjODJhf1SzQ7XLDdMUnpoKUZ 62d5h+ZF+2WqYpOII7cI2R7p35rNHymgbm5KPlvSJHf3xo3Hc7f3n86dqJ6TVpQ++SQ3 PhpA== X-Gm-Message-State: AOAM530Q33TNIWAsWCkDUWXiC74jIG8ISuyt2h3QsKD2yeu7GMvEH8lz RVuRbwcpLbK+fmj8JkXg0xMniA== X-Google-Smtp-Source: ABdhPJyfOTr3NfoG4pa7vgJMAO71CXb8trGz1d/9B8xOJxYcpPa2cnYahVhVGBZH7ZVo9P+QPxqnTA== X-Received: by 2002:a1c:4e10:: with SMTP id g16mr3787777wmh.146.1597829872125; Wed, 19 Aug 2020 02:37:52 -0700 (PDT) Received: from antares.lan (c.d.0.4.4.2.3.3.e.9.1.6.6.d.0.6.f.f.6.2.a.5.a.7.0.b.8.0.1.0.0.2.ip6.arpa. [2001:8b0:7a5a:26ff:60d6:619e:3324:40dc]) by smtp.gmail.com with ESMTPSA id 3sm4204565wms.36.2020.08.19.02.37.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Aug 2020 02:37:51 -0700 (PDT) From: Lorenz Bauer To: jakub@cloudflare.com, john.fastabend@gmail.com, Alexei Starovoitov , Daniel Borkmann , Lorenz Bauer , "David S. Miller" , Jakub Kicinski Cc: kernel-team@cloudflare.com, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf-next 5/6] bpf: sockmap: allow update from BPF Date: Wed, 19 Aug 2020 10:24:35 +0100 Message-Id: <20200819092436.58232-6-lmb@cloudflare.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200819092436.58232-1-lmb@cloudflare.com> References: <20200819092436.58232-1-lmb@cloudflare.com> MIME-Version: 1.0 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Allow calling bpf_map_update_elem on sockmap and sockhash from a BPF context. The synchronization required for this is a bit fiddly: we need to prevent the socket from changing it's state while we add it to the sockmap, since we rely on getting a callback via sk_prot->unhash. However, we can't just lock_sock like in sock_map_sk_acquire because that might sleep. So instead we disable softirq processing and use bh_lock_sock to prevent further modification. Signed-off-by: Lorenz Bauer Acked-by: Yonghong Song --- kernel/bpf/verifier.c | 6 ++++-- net/core/sock_map.c | 24 ++++++++++++++++++++++++ 2 files changed, 28 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 47f9b94bb9d4..421fccf18dea 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4254,7 +4254,8 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, func_id != BPF_FUNC_map_delete_elem && func_id != BPF_FUNC_msg_redirect_map && func_id != BPF_FUNC_sk_select_reuseport && - func_id != BPF_FUNC_map_lookup_elem) + func_id != BPF_FUNC_map_lookup_elem && + func_id != BPF_FUNC_map_update_elem) goto error; break; case BPF_MAP_TYPE_SOCKHASH: @@ -4263,7 +4264,8 @@ static int check_map_func_compatibility(struct bpf_verifier_env *env, func_id != BPF_FUNC_map_delete_elem && func_id != BPF_FUNC_msg_redirect_hash && func_id != BPF_FUNC_sk_select_reuseport && - func_id != BPF_FUNC_map_lookup_elem) + func_id != BPF_FUNC_map_lookup_elem && + func_id != BPF_FUNC_map_update_elem) goto error; break; case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY: diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 018367fb889f..b2c886c34566 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -603,6 +603,28 @@ int sock_map_update_elem_sys(struct bpf_map *map, void *key, return ret; } +static int sock_map_update_elem(struct bpf_map *map, void *key, + void *value, u64 flags) +{ + struct sock *sk = (struct sock *)value; + int ret; + + if (!sock_map_sk_is_suitable(sk)) + return -EOPNOTSUPP; + + local_bh_disable(); + bh_lock_sock(sk); + if (!sock_map_sk_state_allowed(sk)) + ret = -EOPNOTSUPP; + else if (map->map_type == BPF_MAP_TYPE_SOCKMAP) + ret = sock_map_update_common(map, *(u32 *)key, sk, flags); + else + ret = sock_hash_update_common(map, key, sk, flags); + bh_unlock_sock(sk); + local_bh_enable(); + return ret; +} + BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, sops, struct bpf_map *, map, void *, key, u64, flags) { @@ -687,6 +709,7 @@ const struct bpf_map_ops sock_map_ops = { .map_free = sock_map_free, .map_get_next_key = sock_map_get_next_key, .map_lookup_elem_sys_only = sock_map_lookup_sys, + .map_update_elem = sock_map_update_elem, .map_delete_elem = sock_map_delete_elem, .map_lookup_elem = sock_map_lookup, .map_release_uref = sock_map_release_progs, @@ -1180,6 +1203,7 @@ const struct bpf_map_ops sock_hash_ops = { .map_alloc = sock_hash_alloc, .map_free = sock_hash_free, .map_get_next_key = sock_hash_get_next_key, + .map_update_elem = sock_map_update_elem, .map_delete_elem = sock_hash_delete_elem, .map_lookup_elem = sock_hash_lookup, .map_lookup_elem_sys_only = sock_hash_lookup_sys,