From nobody Mon Feb 9 11:33:51 2026 Received: from sonic313-20.consmr.mail.gq1.yahoo.com (sonic313-20.consmr.mail.gq1.yahoo.com [98.137.65.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ABEFB28E5 for ; Sat, 1 Nov 2025 17:33:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=98.137.65.83 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762018438; cv=none; b=mmokwVbuMU0NhD49zqyBlOnaQ6oU5v1yWASOANljjPGhzUtXecFAq3EzmR3gUWmSCiW8tBSv6T0AqNHTthbNDPskQpuVVvQpx3eDVIZ+S/WfH+QI6oGgR5hRaop8wICuq510B2jPyjE2mL9m6RsArLtJXM6wzqcbnrL0zbjK+kg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762018438; c=relaxed/simple; bh=e8ZL1LyoygB8SkFsYZxPEgVD1qzn7F0jji+VxJfTDmo=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type: References; b=IHqIjuIoSWqDqr1Zg5xfRs7KCRxkhJK/Met/wHx71khieB8sYOwPwtca73YrFjXjR1DRN+bWMYwMuqX8e2BDEaiVDQz/qEl5b4USSh0B/TlKe7bK7aDxjeg6tzLADIjGd0phGADersU7jTZePb+KBHKQS4LJtmN4Y20/YBn8OG0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=yahoo.com; spf=pass smtp.mailfrom=yahoo.com; dkim=pass (2048-bit key) header.d=yahoo.com header.i=@yahoo.com header.b=B4a84l28; arc=none smtp.client-ip=98.137.65.83 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=yahoo.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=yahoo.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=yahoo.com header.i=@yahoo.com header.b="B4a84l28" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1762018435; bh=Yk4tqq1qBX5rpgljBx4Mh6L84HEjoDVO45tWqTdErbw=; h=From:To:Cc:Subject:Date:References:From:Subject:Reply-To; b=B4a84l28kAxsKzkaDtCb6TyB43u5FEK58hEI336i4riHanrDYH8/3S3vdcwMH09ZdVLymZ5RLVZmntRcYj2DJC1K0XwOrUt85nsMLNDDzeq/ha4Wj94lvZVzi2q++NrVoc2xgv4fBusjuwKevACEH09YtJ/jh+fHBBeNfFH3jkPtWy7kEOId+tGrjDAfItnYv5c4ZQnlAV598JnFBcC+zp+Dl1WCoTNsE4keeAKO6j12x0yESipB+VxfXwfPq8Tc6xQxogzdbqNz6myEQ72Tr5rDbVx/Qn7V+UyOlNF16ndEDQBsdIMSoX5NJKM5gfMTtS9dTDwfz1v108QSrU/syw== X-SONIC-DKIM-SIGN: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s2048; t=1762018435; bh=rdBfNTTiLppXIeGBrE8VyK4P2fnpzVQZfN0ElSCt/c0=; h=X-Sonic-MF:From:To:Subject:Date:From:Subject; b=AAtAhft3ZI23JSVGEZfhKrLMKBg5VleyNajjl8yxn5nURG2ZNWWvaA8QZEM9O2lPNWYQx0r1qq+awhZrNoZeAvzRpVyqFvK7SxAKjae1y1TheFmn9is0R3vYv1VkglJr1MlIZtzP25S5yeYqRw6tQIQRWr9wSmzzU0Acpr7XZLcrBouYOe2brfMhaCO5eVvcFYmU7N7Mi5bQM6JFe13ao8nkZen5TO47Ynwi+LfDvAQ2F0QzsWwNhy15zWi9lX7gLUaEdheU3tINaB4WfJQGHXLRUiwgaUMugN+fnCWUvUOKNa/NAnLhl01j9IeZ5RRS/njW4gOV23HjkD3Kl1b+xw== X-YMail-OSG: cxGA.asVM1llPaQ4xJFPgaiQLfRshjmjJpvlGliUpT9wHdxvbx81mFyAu1ZtAkC WaxkgVIqGOujmxXj14boktK..vB30pNRx0bnD5648vn1fBDaTtGEozkoeRVXZMcZ5kHIH28nEZE_ IWXpmfNu6HK4WrzECd691IcVhsgkYMI9DgDc9OsYkZdQjfAhC6DVXRnYxJavzxgTxwKkSkRq2lgS lAq8H5n4u6K0GwFBqbp73WT0kgQQqH.xDixG1oQqabHzh4J9ELzppmGZu.8z3W8PbSe2l4hmHf3A DHNadRWCezq54L5POAwBWlWdQ4gkBUYx7gCPPq2LiWCA0bI3D_eNEVgtQVzk7dNLmL6X8gFcJ4DQ I4JWXbfZe4PK.RsKClX8f8oBlZR5Air.4ffKQkcrtaaUxj1Zu7bIK8FkRfvK56_g8QJfdBw_fcV5 RbBJmP4p40wCgb8iZQpaOX4YOqu0b4ijJXxkSi6M0ftEILvlVRVnmp4L3Qjo7mYydXBJ2Bm_yGtt ksrOKFVyy5st9R7CoO3hf.Wh17cB0gq1Yje.8y8riEMbaOiy5m_IAdDUQcMxgXd.BcWqTVpJPiCq WBg_eZYhwf8nBlurcdtHax3Cjh.12clx9ym8kEzahgIW30aM47JHAc2yJCq8XyA2onQ7oTV0MmaP GxLTafsSxWbKgXEMYsFCbPofQJCtp5wAaA.D1WkbtZ9LEOQjn95eKxH3g4lagB8DzMTqGJYfnfTr Nu7rTd_GdXVf6CZogWr6Afrt_RkNCFIk.GkMp4a7nrvVau5L9akFo__DCL.W.wshtQ.aobF_lpbV _J4r_3z70nTY2rAxCGagN.XGiOtx8rqyPpSULMZtmbakD9b_Z9_yO9Dws8EUxXxECihuALbLWTA5 kmHLX69U6ro05zBxSMvcuEyByfoKlZoLD5LHKw_2x0IUaGOoW2Hj1VdZHp_YMAPqm1GyAq4LDtQx tUk78pkLC8MPLaeU6.hIDgdgsUphhOSpmXPCjhaI4ni7dJvccjndhs_o2cZOmaLPplQ5pyXmHIWx ebLe7_E55d9Eawlj4RHWyL2ip1YBPGGFmonjPK9zA46Io90nEaqse0kBU51xgBh7fzN.mCoVNJmb pSt45Fs5Lox5E4_jwqdfAsYb7VJif3HZdUvV7Oq5I3ieupJ9Afg3xNxGIryhjwp34HTePHtDdtZn UkpNC47_XbaRyuU6NrXH7S5gJsrM7g2yp.7eti42nM8bvixyVuFlCAKyGLjtOuLfIvYZIl_XliHv .h81Y1tmQl05tJdl2RJfEhsjXkrJntvuE3uXI6i.22kjpUGxDLXe36_Xg2JTbyufssfWYzI6aBhS BBmG70qOdgaSSg9TYtWYiFuS4.FIKVVZvHxozQlUz9dDKELrPDBEO2UtAhiASseP3MKZhv.Venp1 JNygxfY9BuvU53296Q2TbVYcxO01A7JHhOvyJ14wTR3_ygqzoREhgdZ9UMM6WbHntSs8OAbK2mUo FXsuaUWat49AqdKe1BVhJTanhmJO7zkDPyJ8aqUVPDFv86PHO9uSdxNkT4pjDI0x0r_ItO2jqbha ZKQfL6cZTOoaTwgtBPNPYXf2Dwuw3RROTrjqe8G0f4TrSbYuENRgcZ55.ExuAZ95PaPwnbv9jlXH SOhspyqKdlPAKiNzlRYWY4Os6B_cunV3MvXscUXfOOJKqq5JaDps8mIvdRY7DJxM5VL_N1ldxht5 IIi.9G6VY61Qs.fd_NTRY7aziSriYN1jrqtPzeEImbhXZxEoLGDKF687CwfUGGKyNIr2QDVL2Qgu Ib9EuvSbg9d0ov3M3EQeMd8QoqlR.788ux1mPnUjN3rw_npKD7bnB_1.ATiY.4Xjuaqh28abQQlQ T3syO3wvK29W1vsB00woAz1kbvu2GGQC2kF3RHXY.dhzi6Qb0cPzubpdtrvHHlQeWDoUFjJoB_HV 84LHzHEMQ621CW6aO55XnyE0mxSQTlT.7NENKTfm96.CE1eeStPVTOyCy_voP0mCzS3lQvf9ezGc flkSaPtK9mHdCZi8pojbaj6jydENP0EsJVi0eDvOJW59E6cjvfGKyoYhoa0BC_8OQ2Tu5F.MzNjX Mj.5hAk6y7SHzxyWrO_KOZNNxhupqed_uB7A7DV0lSuUPARd89rpNsb.RIbjAv28hiKbZ4n3RCwD WV993nmj3xBluyJayaKUVhi__iIhYP6SyX7fbqc99r0544enwEny5c9vcDfZj_Wvpx5k0lnv0fAh cB2ylzqG2kfN6WfiMuODQqcV06esTC8gjC_pqS9vrOr8sjHvNbtcR8UY_Fqrxht1_xPu84UPQHIX yzpNjkMtLjZqnL8_E5F_1Dj08M0th2S0yam8- X-Sonic-MF: X-Sonic-ID: 24fd7ac0-5fe7-458f-af33-a32fc4a479e1 Received: from sonic.gate.mail.ne1.yahoo.com by sonic313.consmr.mail.gq1.yahoo.com with HTTP; Sat, 1 Nov 2025 17:33:55 +0000 Received: by hermes--production-bf1-58477f5468-2sh44 (Yahoo Inc. Hermes SMTP Server) with ESMTPA ID 9f9d36950ad92c3931718f2bdffb5879; Sat, 01 Nov 2025 17:23:44 +0000 (UTC) From: Sunday Adelodun To: kuniyu@google.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, shuah@kernel.org Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, skhan@linuxfoundation.org, david.hunter.linux@gmail.com, linux-kernel-mentees@lists.linuxfoundation.org, Sunday Adelodun Subject: [PATCH v3] selftests: af_unix: Add tests for ECONNRESET and EOF semantics Date: Sat, 1 Nov 2025 18:22:30 +0100 Message-ID: <20251101172230.10179-1-adelodunolaoluwa@yahoo.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable References: <20251101172230.10179-1-adelodunolaoluwa.ref@yahoo.com> Add selftests to verify and document Linux=E2=80=99s intended behaviour for UNIX domain sockets (SOCK_STREAM and SOCK_DGRAM) when a peer closes. The tests verify that: 1. SOCK_STREAM returns EOF when the peer closes normally. 2. SOCK_STREAM returns ECONNRESET if the peer closes with unread data. 3. SOCK_SEQPACKET returns EOF when the peer closes normally. 4. SOCK_SEQPACKET returns ECONNRESET if the peer closes with unread data. 5. SOCK_DGRAM does not return ECONNRESET when the peer closes. This follows up on review feedback suggesting a selftest to clarify Linux=E2=80=99s semantics. Suggested-by: Kuniyuki Iwashima Signed-off-by: Sunday Adelodun --- tools/testing/selftests/net/af_unix/Makefile | 1 + .../selftests/net/af_unix/unix_connreset.c | 179 ++++++++++++++++++ 2 files changed, 180 insertions(+) create mode 100644 tools/testing/selftests/net/af_unix/unix_connreset.c diff --git a/tools/testing/selftests/net/af_unix/Makefile b/tools/testing/s= elftests/net/af_unix/Makefile index de805cbbdf69..5826a8372451 100644 --- a/tools/testing/selftests/net/af_unix/Makefile +++ b/tools/testing/selftests/net/af_unix/Makefile @@ -7,6 +7,7 @@ TEST_GEN_PROGS :=3D \ scm_pidfd \ scm_rights \ unix_connect \ + unix_connreset \ # end of TEST_GEN_PROGS =20 include ../../lib.mk diff --git a/tools/testing/selftests/net/af_unix/unix_connreset.c b/tools/t= esting/selftests/net/af_unix/unix_connreset.c new file mode 100644 index 000000000000..6f43435d96e2 --- /dev/null +++ b/tools/testing/selftests/net/af_unix/unix_connreset.c @@ -0,0 +1,179 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Selftest for AF_UNIX socket close and ECONNRESET behaviour. + * + * This test verifies: + * 1. SOCK_STREAM returns EOF when the peer closes normally. + * 2. SOCK_STREAM returns ECONNRESET if peer closes with unread data. + * 3. SOCK_SEQPACKET returns EOF when the peer closes normally. + * 4. SOCK_SEQPACKET returns ECONNRESET if the peer closes with unread da= ta. + * 5. SOCK_DGRAM does not return ECONNRESET when the peer closes. + * + * These tests document the intended Linux behaviour. + * + */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include "../../kselftest_harness.h" + +#define SOCK_PATH "/tmp/af_unix_connreset.sock" + +static void remove_socket_file(void) +{ + unlink(SOCK_PATH); +} + +FIXTURE(unix_sock) +{ + int server; + int client; + int child; +}; + +FIXTURE_VARIANT(unix_sock) +{ + int socket_type; + const char *name; +}; + +/* Define variants: stream and datagram */ +FIXTURE_VARIANT_ADD(unix_sock, stream) { + .socket_type =3D SOCK_STREAM, + .name =3D "SOCK_STREAM", +}; + +FIXTURE_VARIANT_ADD(unix_sock, dgram) { + .socket_type =3D SOCK_DGRAM, + .name =3D "SOCK_DGRAM", +}; + +FIXTURE_VARIANT_ADD(unix_sock, seqpacket) { + .socket_type =3D SOCK_SEQPACKET, + .name =3D "SOCK_SEQPACKET", +}; + +FIXTURE_SETUP(unix_sock) +{ + struct sockaddr_un addr =3D {}; + int err; + + addr.sun_family =3D AF_UNIX; + strcpy(addr.sun_path, SOCK_PATH); + remove_socket_file(); + + self->server =3D socket(AF_UNIX, variant->socket_type, 0); + ASSERT_LT(-1, self->server); + + err =3D bind(self->server, (struct sockaddr *)&addr, sizeof(addr)); + ASSERT_EQ(0, err); + + if (variant->socket_type =3D=3D SOCK_STREAM || + variant->socket_type =3D=3D SOCK_SEQPACKET) { + err =3D listen(self->server, 1); + ASSERT_EQ(0, err); + + self->client =3D socket(AF_UNIX, variant->socket_type, 0); + ASSERT_LT(-1, self->client); + + err =3D connect(self->client, (struct sockaddr *)&addr, sizeof(addr)); + ASSERT_EQ(0, err); + + self->child =3D accept(self->server, NULL, NULL); + ASSERT_LT(-1, self->child); + } else { + /* Datagram: bind and connect only */ + self->client =3D socket(AF_UNIX, SOCK_DGRAM | SOCK_NONBLOCK, 0); + ASSERT_LT(-1, self->client); + + err =3D connect(self->client, (struct sockaddr *)&addr, sizeof(addr)); + ASSERT_EQ(0, err); + } +} + +FIXTURE_TEARDOWN(unix_sock) +{ + if (variant->socket_type =3D=3D SOCK_STREAM || + variant->socket_type =3D=3D SOCK_SEQPACKET) + close(self->child); + + close(self->client); + close(self->server); + remove_socket_file(); +} + +/* Test 1: peer closes normally */ +TEST_F(unix_sock, eof) +{ + char buf[16] =3D {}; + ssize_t n; + + /* Peer closes normally */ + if (variant->socket_type =3D=3D SOCK_STREAM || + variant->socket_type =3D=3D SOCK_SEQPACKET) + close(self->child); + else + close(self->server); + + n =3D recv(self->client, buf, sizeof(buf), 0); + TH_LOG("%s: recv=3D%zd errno=3D%d (%s)", variant->name, n, errno, strerro= r(errno)); + if (variant->socket_type =3D=3D SOCK_STREAM || + variant->socket_type =3D=3D SOCK_SEQPACKET) { + ASSERT_EQ(0, n); + } else { + ASSERT_EQ(-1, n); + ASSERT_EQ(EAGAIN, errno); + } +} + +/* Test 2: peer closes with unread data */ +TEST_F(unix_sock, reset_unread) +{ + char buf[16] =3D {}; + ssize_t n; + + /* Send data that will remain unread by client */ + send(self->client, "hello", 5, 0); + close(self->child); + + n =3D recv(self->client, buf, sizeof(buf), 0); + TH_LOG("%s: recv=3D%zd errno=3D%d (%s)", variant->name, n, errno, strerro= r(errno)); + if (variant->socket_type =3D=3D SOCK_STREAM || + variant->socket_type =3D=3D SOCK_SEQPACKET) { + ASSERT_EQ(-1, n); + ASSERT_EQ(ECONNRESET, errno); + } else { + ASSERT_EQ(-1, n); + ASSERT_EQ(EAGAIN, errno); + } +} + +/* Test 3: SOCK_DGRAM peer close */ +TEST_F(unix_sock, dgram_reset) +{ + char buf[16] =3D {}; + ssize_t n; + + send(self->client, "hello", 5, 0); + close(self->server); + + n =3D recv(self->client, buf, sizeof(buf), 0); + TH_LOG("%s: recv=3D%zd errno=3D%d (%s)", variant->name, n, errno, strerro= r(errno)); + if (variant->socket_type =3D=3D SOCK_STREAM || + variant->socket_type =3D=3D SOCK_SEQPACKET) { + ASSERT_EQ(-1, n); + ASSERT_EQ(ECONNRESET, errno); + } else { + ASSERT_EQ(-1, n); + ASSERT_EQ(EAGAIN, errno); + } +} + +TEST_HARNESS_MAIN + --=20 2.43.0