From patchwork Wed Feb 10 12:04:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenz Bauer X-Patchwork-Id: 1438940 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@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=sparclinux-owner@vger.kernel.org; receiver=) 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=syPwiZlF; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DbJZR4fqJz9rx8 for ; Wed, 10 Feb 2021 23:13:35 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229898AbhBJMNN (ORCPT ); Wed, 10 Feb 2021 07:13:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231671AbhBJMKn (ORCPT ); Wed, 10 Feb 2021 07:10:43 -0500 Received: from mail-wm1-x32e.google.com (mail-wm1-x32e.google.com [IPv6:2a00:1450:4864:20::32e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4C2DC061A27 for ; Wed, 10 Feb 2021 04:04:39 -0800 (PST) Received: by mail-wm1-x32e.google.com with SMTP id o24so1615710wmh.5 for ; Wed, 10 Feb 2021 04:04:39 -0800 (PST) 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=7YlFkcwEzuK8xj1bqWFb4J+pbM9jNy7GJX0y3deB8As=; b=syPwiZlFCfO6MHc40aH33LzcMM6KfDmzRv+D2pLSH5QhqhfJeAI8pcSdpGXIuefrhT QANrLqzWqVKdKDRMI9LkGu7/nHBiH+rC1ieNTWfFHSmkspO5VBaxfKVXb2X2Squ8dPwc gqbcZAWKlW0ioCr6UjiF2eRNBO1Q7kMUruhv0= 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=7YlFkcwEzuK8xj1bqWFb4J+pbM9jNy7GJX0y3deB8As=; b=MFUp+ASRoV0zpZJgWQKaqdI3KTTLXN6OY0GHdzxM2O0VYTtWEw8KyHe36PqvoTIrey dmrQkXk8/Di4lYkZIdTJKHO6o2htR3c1brB683s6IsHOs9sxhrcqSpjyFu2658hzgem+ c54g25CSSO/AvXjcuCnFLlN2lAmtEhCfOOufLNBp8rFYg6BWX2QaOMxuab6QzjcfVDeK xf0hpcn4KweGQ9m+XZpq3zF6a0OiD/vvDQurYl7tnGQ2GpWdW7ifG/Tf7n5uS95Ph5Az T4JJua3SeE+TvXvU/eeNjb78AYFP3zFR5ljNIzSpYHdEv52S+MwFtp3LoDZiE2b6tDBx 9z9Q== X-Gm-Message-State: AOAM531GDCxe121tA2tUdUv19eXIlZE/qp1uW6tTPPTm9jFi2KmuTaGu /Ehl8FVBx3RqDsLtf8AmdKNA4Q== X-Google-Smtp-Source: ABdhPJzWH8Tw+178GsaKwHlgz0XiwPg9erze0gT5N1I/sfwQGjRhxr9XRlOCiSD9NdzdTDxtpCscUA== X-Received: by 2002:a1c:f70c:: with SMTP id v12mr2614677wmh.77.1612958678358; Wed, 10 Feb 2021 04:04:38 -0800 (PST) Received: from antares.lan (c.3.c.9.d.d.c.e.0.a.6.8.a.9.e.c.f.f.6.2.a.5.a.7.0.b.8.0.1.0.0.2.ip6.arpa. [2001:8b0:7a5a:26ff:ce9a:86a0:ecdd:9c3c]) by smtp.gmail.com with ESMTPSA id j7sm2837854wrp.72.2021.02.10.04.04.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Feb 2021 04:04:38 -0800 (PST) From: Lorenz Bauer To: Richard Henderson , Ivan Kokshaysky , Matt Turner , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , "David S. Miller" , Arnd Bergmann , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Jakub Kicinski Cc: kernel-team@cloudflare.com, Lorenz Bauer , linux-api@vger.kernel.org, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH bpf 1/4] net: add SO_NETNS_COOKIE socket option Date: Wed, 10 Feb 2021 12:04:22 +0000 Message-Id: <20210210120425.53438-2-lmb@cloudflare.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210210120425.53438-1-lmb@cloudflare.com> References: <20210210120425.53438-1-lmb@cloudflare.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: sparclinux@vger.kernel.org We need to distinguish which network namespace a socket belongs to. BPF has the useful bpf_get_netns_cookie helper for this, but accessing it from user space isn't possible. Add a read-only socket option that returns the netns cookie, similar to SO_COOKIE. If network namespaces are disabled, SO_NETNS_COOKIE returns the cookie of init_net. The BPF helpers change slightly: instead of returning 0 when network namespaces are disabled we return the init_net cookie as for the socket option. Cc: linux-api@vger.kernel.org Signed-off-by: Lorenz Bauer --- arch/alpha/include/uapi/asm/socket.h | 2 ++ arch/mips/include/uapi/asm/socket.h | 2 ++ arch/parisc/include/uapi/asm/socket.h | 2 ++ arch/sparc/include/uapi/asm/socket.h | 2 ++ include/linux/sock_diag.h | 20 ++++++++++++++++++++ include/uapi/asm-generic/socket.h | 2 ++ net/core/filter.c | 9 ++++----- net/core/sock.c | 7 +++++++ 8 files changed, 41 insertions(+), 5 deletions(-) diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index 57420356ce4c..6b3daba60987 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -127,6 +127,8 @@ #define SO_PREFER_BUSY_POLL 69 #define SO_BUSY_POLL_BUDGET 70 +#define SO_NETNS_COOKIE 71 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index 2d949969313b..cdf404a831b2 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -138,6 +138,8 @@ #define SO_PREFER_BUSY_POLL 69 #define SO_BUSY_POLL_BUDGET 70 +#define SO_NETNS_COOKIE 71 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index f60904329bbc..5b5351cdcb33 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -119,6 +119,8 @@ #define SO_PREFER_BUSY_POLL 0x4043 #define SO_BUSY_POLL_BUDGET 0x4044 +#define SO_NETNS_COOKIE 0x4045 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index 848a22fbac20..ff79db753dce 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -120,6 +120,8 @@ #define SO_PREFER_BUSY_POLL 0x0048 #define SO_BUSY_POLL_BUDGET 0x0049 +#define SO_NETNS_COOKIE 0x004a + #if !defined(__KERNEL__) diff --git a/include/linux/sock_diag.h b/include/linux/sock_diag.h index 0b9ecd8cf979..6e88436097b1 100644 --- a/include/linux/sock_diag.h +++ b/include/linux/sock_diag.h @@ -38,6 +38,26 @@ static inline u64 sock_gen_cookie(struct sock *sk) return cookie; } +static inline u64 __sock_gen_netns_cookie(struct sock *sk) +{ +#ifdef CONFIG_NET_NS + return __net_gen_cookie(sk->sk_net.net); +#else + return __net_gen_cookie(&init_net); +#endif +} + +static inline u64 sock_gen_netns_cookie(struct sock *sk) +{ + u64 cookie; + + preempt_disable(); + cookie = __sock_gen_netns_cookie(sk); + preempt_enable(); + + return cookie; +} + int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie); void sock_diag_save_cookie(struct sock *sk, __u32 *cookie); diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index 4dcd13d097a9..d588c244ec2f 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -122,6 +122,8 @@ #define SO_PREFER_BUSY_POLL 69 #define SO_BUSY_POLL_BUDGET 70 +#define SO_NETNS_COOKIE 71 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__)) diff --git a/net/core/filter.c b/net/core/filter.c index e15d4741719a..51f47b6913f1 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4645,11 +4645,10 @@ static const struct bpf_func_proto bpf_get_socket_cookie_sock_ops_proto = { static u64 __bpf_get_netns_cookie(struct sock *sk) { -#ifdef CONFIG_NET_NS - return __net_gen_cookie(sk ? sk->sk_net.net : &init_net); -#else - return 0; -#endif + if (sk) + return __sock_gen_netns_cookie(sk); + + return __net_gen_cookie(&init_net); } BPF_CALL_1(bpf_get_netns_cookie_sock, struct sock *, ctx) diff --git a/net/core/sock.c b/net/core/sock.c index bbcd4b97eddd..2db201c210ca 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1606,6 +1606,13 @@ int sock_getsockopt(struct socket *sock, int level, int optname, v.val = sk->sk_bound_dev_if; break; + case SO_NETNS_COOKIE: + lv = sizeof(u64); + if (len < lv) + return -EINVAL; + v.val64 = sock_gen_netns_cookie(sk); + break; + default: /* We implement the SO_SNDLOWAT etc to not be settable * (1003.1g 7).