1/*
2 * Check decoding of msg_name* fields of struct msghdr array argument
3 * of sendmmsg and recvmmsg syscalls.
4 *
5 * Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include "tests.h"
32
33#include <errno.h>
34#include <limits.h>
35#include <stddef.h>
36#include <stdio.h>
37#include <string.h>
38#include <unistd.h>
39#include <sys/un.h>
40
41#include "msghdr.h"
42
43#define DEFAULT_STRLEN 32
44
45#define IOV_MAX1 (IOV_MAX + 1)
46
47#ifndef TEST_NAME
48# define TEST_NAME "mmsg_name"
49#endif
50
51static void
52print_msghdr(const struct msghdr *const msg, const int user_msg_namelen)
53{
54	const struct sockaddr_un *const un = msg->msg_name;
55	const int offsetof_sun_path = offsetof(struct sockaddr_un, sun_path);
56
57	printf("{msg_name=");
58	if (!un)
59		printf("NULL");
60	else if (user_msg_namelen < offsetof_sun_path) {
61		printf("%p", un);
62	} else {
63		printf("{sa_family=AF_UNIX");
64		if (user_msg_namelen > offsetof_sun_path) {
65			int len = user_msg_namelen < (int) msg->msg_namelen ?
66				  user_msg_namelen : (int) msg->msg_namelen;
67			len -= offsetof_sun_path;
68			if (len > (int) sizeof(un->sun_path))
69				len = sizeof(un->sun_path);
70			printf(", sun_path=\"%.*s\"", len, un->sun_path);
71		}
72		printf("}");
73	}
74	printf(", msg_namelen=");
75	if (user_msg_namelen != (int) msg->msg_namelen) {
76		printf("%d->", user_msg_namelen);
77	}
78	printf("%d, msg_iov=[{iov_base=\"%c\", iov_len=1}]"
79	       ", msg_iovlen=1, msg_controllen=0, msg_flags=0}",
80	       (int) msg->msg_namelen, * (char *) msg->msg_iov[0].iov_base);
81}
82
83static void
84test_mmsg_name(const int send_fd, const int recv_fd)
85{
86	struct sockaddr_un *const send_addr =
87		tail_alloc(sizeof(*send_addr) * IOV_MAX1);
88	char *const send_buf = tail_alloc(sizeof(*send_buf) * IOV_MAX1);
89	struct iovec *const send_iov = tail_alloc(sizeof(*send_iov) * IOV_MAX1);
90	struct mmsghdr *const send_mh = tail_alloc(sizeof(*send_mh) * IOV_MAX1);
91
92	int i, rc;
93
94	for (i = 0; i < IOV_MAX1; ++i) {
95		int sun_len = i + 1 > (int) sizeof(send_addr[i].sun_path)
96				    ? (int) sizeof(send_addr[i].sun_path)
97				    : i + 1;
98
99		send_addr[i].sun_family = AF_UNIX;
100		memset(send_addr[i].sun_path, 'a' + i % 26, sun_len);
101
102		send_buf[i] = '0' + i % 10;
103
104		send_iov[i].iov_base = &send_buf[i];
105		send_iov[i].iov_len = sizeof(*send_buf);
106
107		send_mh[i].msg_hdr.msg_iov = &send_iov[i];
108		send_mh[i].msg_hdr.msg_iovlen = 1;
109		send_mh[i].msg_hdr.msg_name = &send_addr[i];
110		send_mh[i].msg_hdr.msg_namelen = i + 1;
111		send_mh[i].msg_hdr.msg_control = 0;
112		send_mh[i].msg_hdr.msg_controllen = 0;
113		send_mh[i].msg_hdr.msg_flags = 0;
114	}
115
116	rc = send_mmsg(send_fd, send_mh, IOV_MAX1, MSG_DONTWAIT);
117	int saved_errno = errno;
118
119	printf("sendmmsg(%d, [", send_fd);
120	for (i = 0; i < IOV_MAX1; ++i) {
121		if (i)
122			printf(", ");
123		if (i >= IOV_MAX
124# if !VERBOSE
125			|| i >= DEFAULT_STRLEN
126# endif
127		   ) {
128			printf("...");
129			break;
130		}
131		printf("{msg_hdr=");
132		print_msghdr(&send_mh[i].msg_hdr, i + 1);
133		printf("}");
134	}
135	errno = saved_errno;
136	printf("], %u, MSG_DONTWAIT) = %d %s (%m)\n",
137	       IOV_MAX1, rc, errno2name());
138
139	for (i = 0; i < IOV_MAX1; ++i) {
140		send_mh[i].msg_hdr.msg_name = 0;
141		send_mh[i].msg_hdr.msg_namelen = 0;
142	}
143
144	/*
145	 * When recvmmsg is called with a valid descriptor
146	 * but inaccessible memory, it causes segfaults on some architectures.
147	 * As in these cases we test decoding of failed recvmmsg calls,
148	 * it's ok to fail recvmmsg with any reason as long as
149	 * it doesn't read that inaccessible memory.
150	 */
151	rc = send_mmsg(-1, &send_mh[IOV_MAX], 2, MSG_DONTWAIT);
152	saved_errno = errno;
153	printf("sendmmsg(-1, [{msg_hdr=");
154	print_msghdr(&send_mh[IOV_MAX].msg_hdr, 0);
155	errno = saved_errno;
156	printf("}, %p], %u, MSG_DONTWAIT) = %d %s (%m)\n",
157	       &send_mh[IOV_MAX1], 2, rc, errno2name());
158
159	rc = send_mmsg(send_fd, send_mh, IOV_MAX1, MSG_DONTWAIT);
160	if (rc < 0)
161		perror_msg_and_skip("sendmmsg");
162
163	printf("sendmmsg(%d, [", send_fd);
164	for (i = 0; i < IOV_MAX1; ++i) {
165		if (i)
166			printf(", ");
167		if (i >= IOV_MAX
168#if !VERBOSE
169			|| i >= DEFAULT_STRLEN
170#endif
171		   ) {
172			printf("...");
173			break;
174		}
175		printf("{msg_hdr=");
176		print_msghdr(&send_mh[i].msg_hdr, 0);
177		printf("%s}", i < rc ? ", msg_len=1" : "");
178	}
179	printf("], %u, MSG_DONTWAIT) = %d\n", IOV_MAX1, rc);
180
181	struct sockaddr_un *const recv_addr =
182		tail_alloc(sizeof(*recv_addr) * IOV_MAX1);
183	char *const recv_buf = tail_alloc(sizeof(*recv_buf) * IOV_MAX1);
184	struct iovec *const recv_iov = tail_alloc(sizeof(*recv_iov) * IOV_MAX1);
185	struct mmsghdr *const recv_mh = tail_alloc(sizeof(*recv_mh) * IOV_MAX1);
186
187	for (i = 0; i < IOV_MAX1; ++i) {
188		recv_iov[i].iov_base = &recv_buf[i];
189		recv_iov[i].iov_len = sizeof(*recv_buf);
190
191		recv_mh[i].msg_hdr.msg_name = &recv_addr[i];
192		recv_mh[i].msg_hdr.msg_namelen = i;
193		recv_mh[i].msg_hdr.msg_iov = &recv_iov[i];
194		recv_mh[i].msg_hdr.msg_iovlen = 1;
195		recv_mh[i].msg_hdr.msg_control = 0;
196		recv_mh[i].msg_hdr.msg_controllen = 0;
197		recv_mh[i].msg_hdr.msg_flags = 0;
198	}
199
200	rc = recv_mmsg(recv_fd, recv_mh, IOV_MAX1, MSG_DONTWAIT, 0);
201	if (rc < 0)
202		perror_msg_and_skip("recvmmsg");
203
204	printf("recvmmsg(%d, [", recv_fd);
205	for (i = 0; i < rc; ++i) {
206		if (i)
207			printf(", ");
208#if !VERBOSE
209		if (i >= DEFAULT_STRLEN) {
210			printf("...");
211			break;
212		}
213#endif
214		printf("{msg_hdr=");
215		print_msghdr(&recv_mh[i].msg_hdr, i);
216		printf(", msg_len=1}");
217	}
218	printf("], %u, MSG_DONTWAIT, NULL) = %d\n", IOV_MAX1, rc);
219}
220
221int
222main(void)
223{
224	int fds[2];
225	if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds))
226		perror_msg_and_skip("socketpair");
227
228	const struct sockaddr_un un = {
229		.sun_family = AF_UNIX,
230		.sun_path = TEST_NAME "-recvmmsg.test.send.socket"
231	};
232
233	(void) unlink(un.sun_path);
234	if (bind(fds[1], (const void *) &un, sizeof(un)))
235		perror_msg_and_skip("bind");
236	(void) unlink(un.sun_path);
237
238	test_mmsg_name(fds[1], fds[0]);
239
240	puts("+++ exited with 0 +++");
241	return 0;
242}
243