From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794423330; b=jqfVRiCHCLhDBs2y1a4ZHGugAbT+NngwUrussUkzDnScl9EkFROm511tYR5qWkQajTg6 hIJgTmFQv6MTvs8feQ5MP0GkFiNpjKI4B3QUYhMFn/VpOWpilmnJL/Keq4KXWPvsZNTmN j/8uSW4e3z8bvjT4Ktq1Aq94bKpmIpsk9NtkoTSTr+sK6mSQYaeGZXKUbCRw61PMRnr7e /DTDAHG3L0AkeFE4kTSrm3MNnADz/tcQhyFG1vIGC6jJ2PB82ED2esX6GxLIuFphXOQov w8aq6IC2I3lW8CF178sczs3OtwrJrSMbC4qdkV3M0W9XjnOudMDeAybVMgFKeXNfbRw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794423330; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=TJnpY6z257kJGBN7tvSkztLwnehqtcXSCGdheXOa9oE=; b=pVgpalh1Bbbh2He+Kz2N908WGVIYb5B4XWOdWW2KzrR9HP8YN1Vt0cb42t6X+fhQnxm/ HwdtkLreVDjGlxqzEjNXsYw85va+GGoPenZibqMYEx0rgLqIed2ZC1ncTeeo8B+43Bz2O DIcRjLIIe54ecaftLTGrZCN3E9ET1/NlZgkqNOrOMIccbJc1REvH0iJvRxT7bKzSXTQAg BJI6bo74BdCeUCs9oPWs2pcJ1fIV4XDn5OOUNvapKoUaJVue3uABu6P59nxINp9RuadmH HW1zp3LZnXDXkNa1I015rdbtIUHmOlPvc9E2spgyuohJJHgY34BL4MCpXWQQpFUUhng== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=VEtkbqgy; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 45AD9606A890; Wed, 11 Nov 2026 18:55:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=VEtkbqgy Received: by smtp.kernel.org (Postfix) with ESMTPSA id B53A11F00A07; Wed, 11 Nov 2026 18:55:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794423330; bh=TJnpY6z257kJGBN7tvSkztLwnehqtcXSCGdheXOa9oE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VEtkbqgyWq0glFkTXYHaCPSxfC2yZ0JPPiy+CgMw7/TSBddisd3xuVLDR32N43irC 7otReJDp+Co1KxCbax7eOX+UTfe+j4NrMenseB5nHab1KdmvqieMutPd6N8DrukG41 K9UnOKDpLFnJpRklqSAOvKGdHoZQVk5vSf2T/t44nP4bDRW5tVUwfU6tPwGuAaKCSq DU0PhPf6dsTeOWHE5L8VoEGMCz4VQO6Kl3u6EpJjEFEM7wQzn8u8ZsgOTCaeShcoI0 UDfZm21yX+0qIvvxnBNyx19pez5aXTOrCNeESMaA64wo0ZCjt2eZpR7Sp+D5Mmi9my YxDirRJSprBWA== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, sd@queasysnail.net, john.fastabend@gmail.com, shuah@kernel.org, cel@kernel.org, linux-kselftest@vger.kernel.org, Jakub Kicinski Subject: [PATCH net v2 5/5] selftests: tls: Cover the cap on consecutive empty records Date: Wed, 11 Nov 2026 10:55:22 -0800 Message-ID: <20261111185522.2859004-6-kuba@kernel.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261111185522.2859004-1-kuba@kernel.org> References: <20261111185522.2859004-1-kuba@kernel.org> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Check through both recv() and splice() that a run of 128 empty data records is consumed and the data record behind it is delivered, and that a run of 129 breaks the connection with EBADMSG before the data record can be read. Two runs of 128 with a read returning EAGAIN in between must not break the connection, the cap applies to a burst the reader cannot keep up with, not to the connection as a whole. kTLS cannot send an empty record. A TLS 1.3 record of type 0 whose only byte is the data content type decrypts to one, since the receiver strips the 0 as padding. Reviewed-by: Chuck Lever Signed-off-by: Jakub Kicinski --- v2: no change v1: https://lore.kernel.org/20261109175836.1246840-6-kuba@kernel.org --- tools/testing/selftests/net/tls.c | 124 ++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) diff --git a/tools/testing/selftests/net/tls.c b/tools/testing/selftests/net/tls.c index c505508afde5..bd2797f9f619 100644 --- a/tools/testing/selftests/net/tls.c +++ b/tools/testing/selftests/net/tls.c @@ -2894,6 +2894,130 @@ TEST_F(zero_len_splice, test) close(p[1]); } +FIXTURE(zero_len_run) +{ + int fd, cfd; + bool notls; +}; + +/* Before each of two reads, send n[i] empty records followed by a data + * record if data[i] is set. ret[i] is the result of the read. + */ +FIXTURE_VARIANT(zero_len_run) +{ + unsigned int n[2]; + bool data[2]; + int ret[2]; +}; + +FIXTURE_VARIANT_ADD(zero_len_run, 128) +{ + .n = { 128, 0, }, + .data = { true, false, }, + .ret = { 4, -EAGAIN, }, +}; + +/* More than 128 consecutive empty records break the connection */ +FIXTURE_VARIANT_ADD(zero_len_run, 129) +{ + .n = { 129, 0, }, + .data = { true, false, }, + .ret = { -EBADMSG, -EAGAIN, }, +}; + +/* The count starts over on every read */ +FIXTURE_VARIANT_ADD(zero_len_run, 128_128) +{ + .n = { 128, 128, }, + .data = { false, true, }, + .ret = { -EAGAIN, 4, }, +}; + +FIXTURE_SETUP(zero_len_run) +{ + struct tls_crypto_info_keys tls13; + int ret; + + tls_crypto_info_init(TLS_1_3_VERSION, TLS_CIPHER_AES_GCM_128, + &tls13, 0); + + ulp_sock_pair(_metadata, &self->fd, &self->cfd, &self->notls); + if (self->notls) + return; + + ret = setsockopt(self->fd, SOL_TLS, TLS_TX, &tls13, tls13.len); + ASSERT_EQ(ret, 0); + ret = setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls13, tls13.len); + ASSERT_EQ(ret, 0); +} + +FIXTURE_TEARDOWN(zero_len_run) +{ + close(self->fd); + close(self->cfd); +} + +static void zero_len_run_send(struct __test_metadata *_metadata, int fd, + const FIXTURE_VARIANT(zero_len_run) *variant, + int i) +{ + /* kTLS cannot send an empty record. Send the data content type as + * the only byte of a record of type 0 instead, the receiver strips + * the 0 as padding and sees an empty data record. + */ + char data_type = 0x17; + unsigned int j; + + for (j = 0; j < variant->n[i]; j++) + ASSERT_EQ(tls_send_cmsg(fd, 0, &data_type, 1, 0), 1); + if (variant->data[i]) + ASSERT_EQ(send(fd, "data", 4, 0), 4); +} + +static void zero_len_run_expect(struct __test_metadata *_metadata, + ssize_t ret, int expected) +{ + EXPECT_EQ(ret, expected >= 0 ? expected : -1); + if (expected < 0) + EXPECT_EQ(errno, -expected); +} + +TEST_F(zero_len_run, recv) +{ + char buf[16]; + int i; + + if (self->notls) + SKIP(return, "no TLS support"); + + for (i = 0; i < 2; i++) { + zero_len_run_send(_metadata, self->fd, variant, i); + zero_len_run_expect(_metadata, + recv(self->cfd, buf, sizeof(buf), + MSG_DONTWAIT), + variant->ret[i]); + } +} + +TEST_F(zero_len_run, splice) +{ + int i, p[2]; + + if (self->notls) + SKIP(return, "no TLS support"); + + ASSERT_GE(pipe(p), 0); + for (i = 0; i < 2; i++) { + zero_len_run_send(_metadata, self->fd, variant, i); + zero_len_run_expect(_metadata, + splice(self->cfd, NULL, p[1], NULL, 16, + SPLICE_F_NONBLOCK), + variant->ret[i]); + } + close(p[0]); + close(p[1]); +} + FIXTURE(tls_err) { int fd, cfd; -- 2.56.0