1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2024 Gleb Smirnoff <glebius@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/socket.h>
29#include <sys/un.h>
30#include <assert.h>
31#include <errno.h>
32#include <pthread.h>
33#include <unistd.h>
34#include <netinet/in.h>
35
36#include <atf-c.h>
37
38/*
39 * shutdown(2) on SOCK_DGRAM shall return ENOTCONN per POSIX.  However, there
40 * is historical behavior of the shutdown(2) also unblocking any ongoing
41 * recv(2) syscall on the socket.  It is known that some programs rely on this
42 * behavior, but exact list of programs isn't known.  Neither we know if the
43 * "feature" is required on PF_UNIX sockets or on PF_INET/INET6 sockets or
44 * on both kinds.  Feel free to improve this comment if you know any details.
45 *
46 * List of relevant commits, bug reports and reviews:
47 * 63649db04205
48 * https://reviews.freebsd.org/D10351
49 * b114aa79596c (regresses)
50 * https://reviews.freebsd.org/D3039 (regresses)
51 * kern/84761 c5cff17017f9 aada5cccd878
52 */
53
54
55static void *
56blocking_thread(void *arg)
57{
58	int *s = arg;
59	char buf[1];
60	int error, rv;
61
62	rv = recv(*s, buf, sizeof(buf), 0);
63	error = (rv == -1) ? errno : 0;
64
65	return ((void *)(uintptr_t)error);
66}
67
68static void
69shutdown_thread(int s)
70{
71	pthread_t t;
72	int rv;
73
74	ATF_REQUIRE(pthread_create(&t, NULL, blocking_thread, &s) == 0);
75	usleep(1000);
76	ATF_REQUIRE(shutdown(s, SHUT_RD) == -1);
77	ATF_REQUIRE(errno == ENOTCONN);
78	ATF_REQUIRE(pthread_join(t, (void *)&rv) == 0);
79	ATF_REQUIRE(rv == 0);
80	close(s);
81}
82
83ATF_TC_WITHOUT_HEAD(unblock);
84ATF_TC_BODY(unblock, tc)
85{
86	static const struct sockaddr_un sun = {
87		.sun_family = AF_LOCAL,
88		.sun_len = sizeof(sun),
89		.sun_path = "shutdown-dgram-test-sock",
90	};
91	int s;
92
93	ATF_REQUIRE((s = socket(PF_UNIX, SOCK_DGRAM, 0)) >= 0);
94	ATF_REQUIRE(bind(s, (struct sockaddr *)&sun, sizeof(sun)) == 0);
95	shutdown_thread(s);
96
97	static const struct sockaddr_in sin = {
98		.sin_family = AF_INET,
99		.sin_len = sizeof(sin),
100	};
101	ATF_REQUIRE((s = socket(PF_INET, SOCK_DGRAM, 0)) >= 0);
102	ATF_REQUIRE(bind(s, (struct sockaddr *)&sin, sizeof(sin)) == 0);
103	shutdown_thread(s);
104}
105
106ATF_TP_ADD_TCS(tp)
107{
108	ATF_TP_ADD_TC(tp, unblock);
109
110	return (atf_no_error());
111}
112