lib/tsocket: Add tests for loop on EAGAIN

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15202

Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>

Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>

4 files changed, 641 insertions, 0 deletions

diff --git a/lib/tsocket/tests/socketpair_tcp.c b/lib/tsocket/tests/socketpair_tcp.c
new file mode 100644
index 00000000000..251b8bc0212
--- /dev/null
+++ b/lib/tsocket/tests/socketpair_tcp.c
@@ -0,0 +1,89 @@
+/*
+   Unix SMB/CIFS implementation.
+   Samba utility functions
+   Copyright (C) Andrew Tridgell 1992-1998
+   Copyright (C) Tim Potter      2000-2001
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "system/network.h"
+#include "socketpair_tcp.h"
+
+/*******************************************************************
+this is like socketpair but uses tcp. It is used by the Samba
+regression test code
+The function guarantees that nobody else can attach to the socket,
+or if they do that this function fails and the socket gets closed
+returns 0 on success, -1 on failure
+the resulting file descriptors are symmetrical
+ ******************************************************************/
+int socketpair_tcp(int fd[2])
+{
+	int listener;
+	struct sockaddr_in sock;
+	struct sockaddr_in sock2;
+	socklen_t socklen = sizeof(sock);
+	int connect_done = 0;
+
+	fd[0] = fd[1] = listener = -1;
+
+	memset(&sock, 0, sizeof(sock));
+
+	if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
+
+	memset(&sock2, 0, sizeof(sock2));
+#ifdef HAVE_SOCK_SIN_LEN
+	sock2.sin_len = sizeof(sock2);
+#endif
+	sock2.sin_family = PF_INET;
+
+	if (bind(listener, (struct sockaddr *)&sock2, sizeof(sock2)) != 0) goto failed;
+
+	if (listen(listener, 1) != 0) goto failed;
+
+	if (getsockname(listener, (struct sockaddr *)&sock, &socklen) != 0) goto failed;
+
+	if ((fd[1] = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed;
+
+	set_blocking(fd[1], 0);
+
+	sock.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+	if (connect(fd[1], (struct sockaddr *)&sock, socklen) == -1) {
+		if (errno != EINPROGRESS) goto failed;
+	} else {
+		connect_done = 1;
+	}
+
+	if ((fd[0] = accept(listener, (struct sockaddr *)&sock, &socklen)) == -1) goto failed;
+
+	if (connect_done == 0) {
+		if (connect(fd[1], (struct sockaddr *)&sock, socklen) != 0
+		    && errno != EISCONN) goto failed;
+	}
+	close(listener);
+
+	set_blocking(fd[1], 1);
+
+	/* all OK! */
+	return 0;
+
+ failed:
+	if (fd[0] != -1) close(fd[0]);
+	if (fd[1] != -1) close(fd[1]);
+	if (listener != -1) close(listener);
+	return -1;
+}
diff --git a/lib/tsocket/tests/socketpair_tcp.h b/lib/tsocket/tests/socketpair_tcp.h
new file mode 100644
index 00000000000..dbee4efec70
--- /dev/null
+++ b/lib/tsocket/tests/socketpair_tcp.h
@@ -0,0 +1,29 @@
+/*
+   Unix SMB/CIFS implementation.
+   Samba utility functions
+   Copyright (C) Andrew Tridgell 1992-1998
+   Copyright (C) Tim Potter      2000-2001
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*******************************************************************
+this is like socketpair but uses tcp. It is used by the Samba
+regression test code
+The function guarantees that nobody else can attach to the socket,
+or if they do that this function fails and the socket gets closed
+returns 0 on success, -1 on failure
+the resulting file descriptors are symmetrical
+ ******************************************************************/
+int socketpair_tcp(int fd[2]);
diff --git a/lib/tsocket/tests/test_tstream.c b/lib/tsocket/tests/test_tstream.c
new file mode 100644
index 00000000000..a920e671cda
--- /dev/null
+++ b/lib/tsocket/tests/test_tstream.c
@@ -0,0 +1,517 @@
+/*
+ * Unix SMB/CIFS implementation.
+ *
+ * Copyright (C) 2022      Andrew Bartlett <abartlet@samba.org>
+ * Copyright (C) 2021      Andreas Schneider <asn@samba.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <setjmp.h>
+#include <cmocka.h>
+#include "includes.h"
+#include "system/network.h"
+#include "socketpair_tcp.h"
+#include "tsocket.h"
+
+enum socket_pair_selector {
+	SOCKET_SERVER = 0,
+	SOCKET_CLIENT = 1,
+};
+
+struct socket_pair {
+	struct tevent_context *ev;
+	int socket_server;
+	int socket_client;
+
+	/* for tstream tests */
+	int rc;
+	int sys_errno;
+	int expected_errno;
+	struct timeval endtime;
+	size_t max_loops;
+	size_t num_loops;
+};
+
+/* If this is too large, we get EPIPE rather than EAGAIN */
+static const uint8_t TEST_STRING[128] = { 0 };
+
+static int sigpipe_setup(void **state)
+{
+	BlockSignals(true, SIGPIPE);
+	return 0;
+}
+
+static int setup_socketpair_tcp_context(void **state)
+{
+	int fd[2];
+	struct socket_pair *sp = talloc_zero(NULL, struct socket_pair);
+	assert_non_null(sp);
+
+	/* Set up a socketpair over TCP to test with */
+	assert_return_code(socketpair_tcp(fd), errno);
+
+	sp->socket_server = fd[SOCKET_SERVER];
+	sp->socket_client = fd[SOCKET_CLIENT];
+
+	sp->ev = tevent_context_init(sp);
+	assert_non_null(sp->ev);
+
+	*state = sp;
+	return 0;
+}
+
+static int setup_socketpair_context(void **state)
+{
+	int fd[2];
+	struct socket_pair *sp = talloc_zero(NULL, struct socket_pair);
+	assert_non_null(sp);
+
+	/* Set up a socketpair over TCP to test with */
+	assert_return_code(socketpair(AF_UNIX, SOCK_STREAM, 0, fd), errno);
+
+	sp->socket_server = fd[SOCKET_SERVER];
+	sp->socket_client = fd[SOCKET_CLIENT];
+
+	sp->ev = tevent_context_init(sp);
+	assert_non_null(sp->ev);
+
+	*state = sp;
+	return 0;
+}
+
+static int teardown_socketpair_context(void **state)
+{
+	struct socket_pair *sp = *state;
+	struct socket_pair sp_save = *sp;
+
+	TALLOC_FREE(sp);
+
+	/*
+	 * Close these after the TALLOC_FREE() to allow clean shutdown
+	 * of epoll() in tstream
+	 */
+	if (sp_save.socket_client != -1) {
+		close(sp_save.socket_client);
+	}
+	if (sp_save.socket_server != -1) {
+		close(sp_save.socket_server);
+	}
+	return 0;
+}
+
+
+/* Test socket behaviour */
+static void test_simple_socketpair(void **state) {
+
+	struct socket_pair *sp = *state;
+
+	char buf[sizeof(TEST_STRING)];
+
+	assert_int_equal(write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING)),
+			 sizeof(TEST_STRING));
+	assert_int_equal(read(sp->socket_client, buf, sizeof(buf)),
+			 sizeof(buf));
+
+
+}
+
+/* Test socket behaviour */
+static void test_read_client_after_close_server_socket(void **state) {
+
+	struct socket_pair *sp = *state;
+	int rc;
+	char buf[sizeof(TEST_STRING)];
+
+	rc = write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING));
+	assert_return_code(rc, errno);
+	assert_int_equal(rc, sizeof(TEST_STRING));
+
+	assert_return_code(close(sp->socket_server), 0);
+
+	rc = read(sp->socket_client, buf, sizeof(buf));
+
+	assert_return_code(rc, errno);
+	assert_int_equal(rc, sizeof(buf));
+}
+
+static void test_write_server_after_close_client_socket(void **state) {
+
+	struct socket_pair *sp = *state;
+	int rc;
+
+	assert_return_code(close(sp->socket_client), 0);
+	sp->socket_client = -1;
+
+	rc = write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING));
+	assert_return_code(rc, errno);
+	assert_int_equal(rc, sizeof(TEST_STRING));
+}
+
+static void test_fill_socket(int sock)
+{
+	size_t num_busy = 0;
+	int rc;
+
+	while (true) {
+		rc = write(sock, TEST_STRING, sizeof(TEST_STRING));
+		if (rc == -1 && errno == EAGAIN) {
+			/*
+			 * This makes sure we write until we get a whole second
+			 * only with EAGAIN every 50 ms (20 times)
+			 *
+			 * Otherwise the tests are not reliable...
+			 */
+			num_busy++;
+			if (num_busy > 20) {
+				break;
+			}
+			smb_msleep(50);
+			continue;
+		}
+		/* try again next time */
+		num_busy = 0;
+	}
+
+	assert_int_equal(rc, -1);
+	assert_int_equal(errno, EAGAIN);
+}
+
+static void test_big_write_server(void **state) {
+
+	struct socket_pair *sp = *state;
+	int rc;
+
+	rc = write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING));
+	assert_return_code(rc, errno);
+	assert_int_equal(rc, sizeof(TEST_STRING));
+
+	rc = set_blocking(sp->socket_server, 0);
+	assert_return_code(rc, errno);
+
+	test_fill_socket(sp->socket_server);
+}
+
+static void test_big_write_server_close_write(void **state) {
+
+	struct socket_pair *sp = *state;
+	int rc;
+
+	rc = write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING));
+	assert_return_code(rc, errno);
+	assert_int_equal(rc, sizeof(TEST_STRING));
+
+	rc = set_blocking(sp->socket_server, 0);
+	assert_return_code(rc, errno);
+
+	test_fill_socket(sp->socket_server);
+
+	assert_return_code(close(sp->socket_client), 0);
+	sp->socket_client = -1;
+
+	rc = write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING));
+	assert_int_equal(errno, ECONNRESET);
+
+}
+
+static void test_big_write_server_shutdown_wr_write(void **state) {
+
+	struct socket_pair *sp = *state;
+	int rc;
+
+	rc = write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING));
+	assert_return_code(rc, errno);
+	assert_int_equal(rc, sizeof(TEST_STRING));
+
+	rc = set_blocking(sp->socket_server, 0);
+	assert_return_code(rc, errno);
+
+	test_fill_socket(sp->socket_server);
+
+	assert_return_code(shutdown(sp->socket_client, SHUT_WR), 0);
+	sp->socket_client = -1;
+
+	rc = write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING));
+	assert_int_equal(rc, -1);
+	assert_int_equal(errno, EAGAIN);
+}
+
+static void test_big_write_server_shutdown_rd_write(void **state) {
+
+	struct socket_pair *sp = *state;
+	int rc;
+
+	rc = write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING));
+	assert_return_code(rc, errno);
+	assert_int_equal(rc, sizeof(TEST_STRING));
+
+	rc = set_blocking(sp->socket_server, 0);
+	assert_return_code(rc, errno);
+
+	test_fill_socket(sp->socket_server);
+
+	assert_return_code(shutdown(sp->socket_client, SHUT_RD), 0);
+	sp->socket_client = -1;
+
+	rc = write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING));
+	assert_int_equal(rc, -1);
+	assert_int_equal(errno, EAGAIN);
+}
+
+static void test_call_writev_done(struct tevent_req *subreq)
+{
+	struct socket_pair *sp =
+		tevent_req_callback_data(subreq,
+		struct socket_pair);
+	int rc;
+
+	rc = tstream_writev_recv(subreq, &sp->sys_errno);
+	TALLOC_FREE(subreq);
+
+	sp->rc = rc;
+}
+
+static void test_tstream_server_spin_client_shutdown(struct socket_pair *sp)
+{
+	int rc;
+
+	rc = shutdown(sp->socket_client, SHUT_WR);
+	assert_return_code(rc, errno);
+	/*
+	 * It should only take a few additional loop to realise that this socket is
+	 * in CLOSE_WAIT
+	 */
+	sp->max_loops = sp->num_loops + 2;
+	sp->expected_errno = ECONNRESET;
+}
+
+static void test_tstream_server_spin_client_write(struct socket_pair *sp)
+{
+	int rc;
+	int timeout = 5000;
+
+	sp->endtime = timeval_current_ofs_msec(timeout);
+
+	rc = write(sp->socket_client, TEST_STRING, sizeof(TEST_STRING));
+	assert_return_code(rc, errno);
+	sp->expected_errno = ETIMEDOUT;
+}
+
+static void test_tstream_server_spin_client_tcp_user_timeout(struct socket_pair *sp)
+{
+	int rc;
+	int timeout = 5000;
+
+	rc = setsockopt(sp->socket_server, IPPROTO_TCP, TCP_USER_TIMEOUT, &timeout, sizeof(timeout));
+	assert_return_code(rc, errno);
+
+	rc = write(sp->socket_client, TEST_STRING, sizeof(TEST_STRING));
+	assert_return_code(rc, errno);
+	sp->expected_errno = ETIMEDOUT;
+	sp->max_loops = 15;
+}
+
+static void test_tstream_server_spin_client_both_timer(struct tevent_context *ev,
+						       struct tevent_timer *te,
+						       struct timeval current_time,
+						       void *private_data)
+{
+	struct socket_pair *sp =
+		talloc_get_type_abort(private_data,
+		struct socket_pair);
+
+	test_tstream_server_spin_client_shutdown(sp);
+}
+
+static void test_tstream_server_spin_client_both(struct socket_pair *sp)
+{
+	struct tevent_timer *te = NULL;
+	struct timeval endtime;
+
+	test_tstream_server_spin_client_write(sp);
+
+	endtime = timeval_current_ofs_msec(2500);
+
+	te = tevent_add_timer(sp->ev,
+			      sp,
+			      endtime,
+			      test_tstream_server_spin_client_both_timer,
+			      sp);
+	assert_non_null(te);
+	sp->expected_errno = ENXIO;
+}
+
+static void test_tstream_server_spin(struct socket_pair *sp,
+				     void (*client_fn)(struct socket_pair *sp))
+{
+	struct tstream_context *stream = NULL;
+	struct tevent_req *req = NULL;
+	struct iovec iov;
+	int rc;
+
+	rc = write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING));
+	assert_return_code(rc, errno);
+	assert_int_equal(rc, sizeof(TEST_STRING));
+
+	rc = set_blocking(sp->socket_server, 0);
+	assert_return_code(rc, errno);
+
+	test_fill_socket(sp->socket_server);
+
+	/*
+	 * by default we don't expect more then 2 loop iterations
+	 * for a timeout of 5 seconds.
+	 */
+	sp->max_loops = 10;
+
+	client_fn(sp);
+
+	rc = write(sp->socket_server, TEST_STRING, sizeof(TEST_STRING));
+	assert_int_equal(rc, -1);
+	assert_int_equal(errno, EAGAIN);
+
+	/* OK, so we now know the socket is in CLOSE_WAIT */
+
+	rc = tstream_bsd_existing_socket(sp->ev, sp->socket_server, &stream);
+	assert_return_code(rc, errno);
+	sp->socket_server = -1;
+
+	iov.iov_base = discard_const_p(char, TEST_STRING);
+	iov.iov_len = sizeof(TEST_STRING);
+
+	req = tstream_writev_send(stream, sp->ev, stream, &iov, 1);
+	assert_non_null(req);
+	if (!timeval_is_zero(&sp->endtime)) {
+		assert_true(tevent_req_set_endtime(req, sp->ev, sp->endtime));
+	}
+	tevent_req_set_callback(req, test_call_writev_done, sp);
+
+	while (tevent_req_is_in_progress(req)) {
+		if (sp->num_loops >= sp->max_loops) {
+			assert_int_not_equal(sp->num_loops, sp->max_loops);
+			assert_int_equal(sp->num_loops, sp->max_loops);
+		}
+		sp->num_loops += 1;
+
+		rc = tevent_loop_once(sp->ev);
+		assert_int_equal(rc, 0);
+	}
+
+	assert_int_equal(sp->rc, -1);
+	assert_int_equal(sp->sys_errno, sp->expected_errno);
+	return;
+}
+
+/*
+ * We need two names to run this with the two different setup
+ * routines
+ */
+static void test_tstream_disconnected_tcp_client_spin(void **state)
+{
+	struct socket_pair *sp = *state;
+	test_tstream_server_spin(sp, test_tstream_server_spin_client_shutdown);
+}
+
+static void test_tstream_disconnected_unix_client_spin(void **state)
+{
+	struct socket_pair *sp = *state;
+	test_tstream_server_spin(sp, test_tstream_server_spin_client_shutdown);
+}
+
+static void test_tstream_more_tcp_client_spin(void **state)
+{
+	struct socket_pair *sp = *state;
+	test_tstream_server_spin(sp, test_tstream_server_spin_client_write);
+}
+
+static void test_tstream_more_unix_client_spin(void **state)
+{
+	struct socket_pair *sp = *state;
+	test_tstream_server_spin(sp, test_tstream_server_spin_client_write);
+}
+
+static void test_tstream_more_disconnect_tcp_client_spin(void **state)
+{
+	struct socket_pair *sp = *state;
+	test_tstream_server_spin(sp, test_tstream_server_spin_client_both);
+}
+
+static void test_tstream_more_disconnect_unix_client_spin(void **state)
+{
+	struct socket_pair *sp = *state;
+	test_tstream_server_spin(sp, test_tstream_server_spin_client_both);
+}
+
+static void test_tstream_more_tcp_user_timeout_spin(void **state)
+{
+	struct socket_pair *sp = *state;
+	if (socket_wrapper_enabled()) {
+		skip();
+	}
+	test_tstream_server_spin(sp, test_tstream_server_spin_client_tcp_user_timeout);
+}
+
+int main(void) {
+	const struct CMUnitTest tests[] = {
+		cmocka_unit_test_setup_teardown(test_simple_socketpair,
+						setup_socketpair_tcp_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_read_client_after_close_server_socket,
+						setup_socketpair_tcp_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_write_server_after_close_client_socket,
+						setup_socketpair_tcp_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_big_write_server,
+						setup_socketpair_tcp_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_big_write_server_close_write,
+						setup_socketpair_tcp_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_big_write_server_shutdown_wr_write,
+						setup_socketpair_tcp_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_big_write_server_shutdown_rd_write,
+						setup_socketpair_tcp_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_tstream_disconnected_tcp_client_spin,
+						setup_socketpair_tcp_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_tstream_disconnected_unix_client_spin,
+						setup_socketpair_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_tstream_more_tcp_client_spin,
+						setup_socketpair_tcp_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_tstream_more_unix_client_spin,
+						setup_socketpair_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_tstream_more_disconnect_tcp_client_spin,
+						setup_socketpair_tcp_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_tstream_more_disconnect_unix_client_spin,
+						setup_socketpair_context,
+						teardown_socketpair_context),
+		cmocka_unit_test_setup_teardown(test_tstream_more_tcp_user_timeout_spin,
+						setup_socketpair_tcp_context,
+						teardown_socketpair_context),
+	};
+
+	cmocka_set_message_output(CM_OUTPUT_SUBUNIT);
+
+	return cmocka_run_group_tests(tests, sigpipe_setup, NULL);
+}
diff --git a/lib/tsocket/wscript_build b/lib/tsocket/wscript_build
index 8fe83f16f11..73adcb9628d 100644
--- a/lib/tsocket/wscript_build
+++ b/lib/tsocket/wscript_build
@@ -13,3 +13,9 @@ bld.SAMBA_BINARY('test_tsocket_bsd_addr',
                  local_include=False,
                  for_selftest=True)
 
+bld.SAMBA_BINARY('test_tstream',
+                 source='tests/test_tstream.c tests/socketpair_tcp.c',
+                 deps='cmocka replace LIBTSOCKET',
+                 local_include=False,
+                 for_selftest=True)
+