From patchwork Thu Apr 13 13:33:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Mikhalitsyn X-Patchwork-Id: 13210317 X-Patchwork-Delegate: kuba@kernel.org 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40A74C77B76 for ; Thu, 13 Apr 2023 13:38:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231604AbjDMNiN (ORCPT ); Thu, 13 Apr 2023 09:38:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230179AbjDMNh3 (ORCPT ); Thu, 13 Apr 2023 09:37:29 -0400 Received: from smtp-relay-internal-1.canonical.com (smtp-relay-internal-1.canonical.com [185.125.188.123]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5249FD50B for ; Thu, 13 Apr 2023 06:35:17 -0700 (PDT) Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-internal-1.canonical.com (Postfix) with ESMTPS id 140FE3F22C for ; Thu, 13 Apr 2023 13:34:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1681392880; bh=tINNpmFGgSXRr6eO7vUL42OoLzt52EnFT+KFr84tTSM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=vXuHbTaguN6pcwIN0GLuFfgJTjdb1O6y8CKyKKXkJmr119QbBG8uVK9l2YRiCm7wD QPD+uccYtvPjGiT5xwqLN/eLCwXsaIWuPGtQ8jMSdC4K6Dxkjave2VoiuuFe+G8q0t UUY38spWLVMMA4iT1OYkAUS6fVpJBfkH6eMj4+BJx3uaKJG/bwDdBD4xn+jHiHd3Re XVY9mjwC6JAfyPsfxDOwS+MneJL6NlM0iIhpaU/tj3+Fo4BQYaoV1UV+4p95NJ7pMI jYDYMNaUj75MixPZf7cPpPyLpvTXPVzC56uNJcQ/LX7j0pWHgnQBufU/bCzThxURzv 4JoZ9NAm89ROw== Received: by mail-ed1-f69.google.com with SMTP id e20-20020a50d4d4000000b00505059e6162so2629770edj.11 for ; Thu, 13 Apr 2023 06:34:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681392879; x=1683984879; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=tINNpmFGgSXRr6eO7vUL42OoLzt52EnFT+KFr84tTSM=; b=XIzwy53XHquowS/uBdPeWYHPkrSDjqAsjuko9DtcjuCkQ+IM37h5hInPJ4lxoLRZWS RrACNEJ33dFncdTt6Oq3ZMzNyjbjh3Oig31peAXmWIlYlkDzrMQhDgey8O002ZnmWto2 aQXN/szADtdJnPPPH7xte/g2o9+ND/XIBQKpnjz3VmvCvYf1qRDiVEbxHisFtL6Py5L8 31itPdW2CPjK5ZbWn1SaRp6A4l19Ay0yQPXh/wdAbWqx7C6w7rh/tYJnTpUruXL6QpB1 VXImo3pCsHQ/ZSlBIyPFfLnHzEED9RPBtGyVvZvDa/v2XNfPYCbKKdjXbbCz67PtUqoU t6LQ== X-Gm-Message-State: AAQBX9eWD3idfEwd8/PumjiSM3c4X/tbrNOVNquauskMGkjR/5EZFvsC GhwT7oOtih76LLybCqlsTyQNQTk6KweBu/IybAMEGacowU+3Zx9jiS6VYwrUuCDpdrickv9T2fP JoVtKaeIbRkgHhtreDtweyDDl5xfoH/PG2g== X-Received: by 2002:a17:906:57d0:b0:94a:62e7:70e1 with SMTP id u16-20020a17090657d000b0094a62e770e1mr2718796ejr.68.1681392879594; Thu, 13 Apr 2023 06:34:39 -0700 (PDT) X-Google-Smtp-Source: AKy350bWyh1fpNfKciV+c7c09q66s0vrF8zu0AQeMYpVtpd/3rM0AMu+N1JJw82j5x6TBlII2M7uJA== X-Received: by 2002:a17:906:57d0:b0:94a:62e7:70e1 with SMTP id u16-20020a17090657d000b0094a62e770e1mr2718777ejr.68.1681392879298; Thu, 13 Apr 2023 06:34:39 -0700 (PDT) Received: from amikhalitsyn.. ([95.91.208.118]) by smtp.gmail.com with ESMTPSA id et22-20020a170907295600b0094a966330fdsm976806ejc.211.2023.04.13.06.34.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Apr 2023 06:34:38 -0700 (PDT) From: Alexander Mikhalitsyn To: davem@davemloft.net Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, daniel@iogearbox.net, Alexander Mikhalitsyn , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Leon Romanovsky , David Ahern , Arnd Bergmann , Kees Cook , Christian Brauner , Kuniyuki Iwashima , Lennart Poettering , Luca Boccassi , linux-arch@vger.kernel.org Subject: [PATCH net-next v4 3/4] net: core: add getsockopt SO_PEERPIDFD Date: Thu, 13 Apr 2023 15:33:54 +0200 Message-Id: <20230413133355.350571-4-aleksandr.mikhalitsyn@canonical.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230413133355.350571-1-aleksandr.mikhalitsyn@canonical.com> References: <20230413133355.350571-1-aleksandr.mikhalitsyn@canonical.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Add SO_PEERPIDFD which allows to get pidfd of peer socket holder pidfd. This thing is direct analog of SO_PEERCRED which allows to get plain PID. Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: Leon Romanovsky Cc: David Ahern Cc: Arnd Bergmann Cc: Kees Cook Cc: Christian Brauner Cc: Kuniyuki Iwashima Cc: Lennart Poettering Cc: Luca Boccassi Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-arch@vger.kernel.org Tested-by: Luca Boccassi Signed-off-by: Alexander Mikhalitsyn Reviewed-by: Christian Brauner --- v4: - return -ESRCH if sk->sk_peer_pid is NULL from getsockopt() syscall - return errors from pidfd_prepare() as it is from getsockopt() syscall v3: - fixed possible fd leak (thanks to Christian Brauner) v2: According to review comments from Kuniyuki Iwashima and Christian Brauner: - use pidfd_create(..) retval as a result - whitespace change --- arch/alpha/include/uapi/asm/socket.h | 1 + arch/mips/include/uapi/asm/socket.h | 1 + arch/parisc/include/uapi/asm/socket.h | 1 + arch/sparc/include/uapi/asm/socket.h | 1 + include/uapi/asm-generic/socket.h | 1 + net/core/sock.c | 33 +++++++++++++++++++++++++ net/socket.c | 7 ++++++ tools/include/uapi/asm-generic/socket.h | 1 + 8 files changed, 46 insertions(+) diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index ff310613ae64..e94f621903fe 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -138,6 +138,7 @@ #define SO_RCVMARK 75 #define SO_PASSPIDFD 76 +#define SO_PEERPIDFD 77 #if !defined(__KERNEL__) diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index 762dcb80e4ec..60ebaed28a4c 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -149,6 +149,7 @@ #define SO_RCVMARK 75 #define SO_PASSPIDFD 76 +#define SO_PEERPIDFD 77 #if !defined(__KERNEL__) diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index df16a3e16d64..be264c2b1a11 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -130,6 +130,7 @@ #define SO_RCVMARK 0x4049 #define SO_PASSPIDFD 0x404A +#define SO_PEERPIDFD 0x404B #if !defined(__KERNEL__) diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index 6e2847804fea..682da3714686 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -131,6 +131,7 @@ #define SO_RCVMARK 0x0054 #define SO_PASSPIDFD 0x0055 +#define SO_PEERPIDFD 0x0056 #if !defined(__KERNEL__) diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index b76169fdb80b..8ce8a39a1e5f 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -133,6 +133,7 @@ #define SO_RCVMARK 75 #define SO_PASSPIDFD 76 +#define SO_PEERPIDFD 77 #if !defined(__KERNEL__) diff --git a/net/core/sock.c b/net/core/sock.c index 3f974246ba3e..49531c0dc57f 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1763,6 +1763,39 @@ int sk_getsockopt(struct sock *sk, int level, int optname, goto lenout; } + case SO_PEERPIDFD: + { + struct pid *peer_pid; + struct file *pidfd_file = NULL; + int pidfd; + + if (len > sizeof(pidfd)) + len = sizeof(pidfd); + + spin_lock(&sk->sk_peer_lock); + peer_pid = get_pid(sk->sk_peer_pid); + spin_unlock(&sk->sk_peer_lock); + + if (!peer_pid) + return -ESRCH; + + pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file); + put_pid(peer_pid); + if (pidfd < 0) + return pidfd; + + if (copy_to_sockptr(optval, &pidfd, len) || + copy_to_sockptr(optlen, &len, sizeof(int))) { + put_unused_fd(pidfd); + fput(pidfd_file); + + return -EFAULT; + } + + fd_install(pidfd, pidfd_file); + return 0; + } + case SO_PEERGROUPS: { const struct cred *cred; diff --git a/net/socket.c b/net/socket.c index 9c1ef11de23f..505b85489354 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2248,6 +2248,13 @@ static bool sockopt_installs_fd(int level, int optname) default: return false; } + } else if (level == SOL_SOCKET) { + switch (optname) { + case SO_PEERPIDFD: + return true; + default: + return false; + } } return false; diff --git a/tools/include/uapi/asm-generic/socket.h b/tools/include/uapi/asm-generic/socket.h index fbbc4bf53ee3..54d9c8bf7c55 100644 --- a/tools/include/uapi/asm-generic/socket.h +++ b/tools/include/uapi/asm-generic/socket.h @@ -122,6 +122,7 @@ #define SO_RCVMARK 75 #define SO_PASSPIDFD 76 +#define SO_PEERPIDFD 77 #if !defined(__KERNEL__)