unfdpass.c revision 1.1 
1/*	$NetBSD: unfdpass.c,v 1.3 1998/06/24 23:51:30 thorpej Exp $	*/
2
3/*-
4 * Copyright (c) 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 *    must display the following acknowledgement:
21 *	This product includes software developed by the NetBSD
22 *	Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 *    contributors may be used to endorse or promote products derived
25 *    from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40/*
41 * Test passing of file descriptors and credentials over Unix domain sockets.
42 */
43
44#include <sys/param.h>
45#include <sys/socket.h>
46#include <sys/time.h>
47#include <sys/wait.h>
48#include <sys/un.h>
49#include <err.h>
50#include <errno.h>
51#include <fcntl.h>
52#include <signal.h>
53#include <stdio.h>
54#include <string.h>
55#include <unistd.h>
56
57#define	SOCK_NAME	"test-sock"
58
59int	main __P((int, char *[]));
60void	child __P((void));
61void	catch_sigchld __P((int));
62
63struct fdcmessage {
64	struct cmsghdr cm;
65	int files[2];
66};
67
68struct crcmessage {
69	struct cmsghdr cm;
70	char creds[SOCKCREDSIZE(NGROUPS)];
71};
72
73/* ARGSUSED */
74int
75main(argc, argv)
76	int argc;
77	char *argv[];
78{
79	struct msghdr msg;
80	int listensock, sock, fd, i, status;
81	char fname[16], buf[64];
82	struct cmsghdr *cmp;
83	struct {
84		struct fdcmessage fdcm;
85		struct crcmessage crcm;
86	} message;
87	int *files = NULL;
88	struct sockcred *sc = NULL;
89	struct sockaddr_un sun, csun;
90	int csunlen;
91	fd_set oob;
92	pid_t pid;
93
94	/*
95	 * Create the test files.
96	 */
97	for (i = 0; i < 2; i++) {
98		(void) sprintf(fname, "file%d", i + 1);
99		if ((fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) == -1)
100			err(1, "open %s", fname);
101		(void) sprintf(buf, "This is file %d.\n", i + 1);
102		if (write(fd, buf, strlen(buf)) != strlen(buf))
103			err(1, "write %s", fname);
104		(void) close(fd);
105	}
106
107	/*
108	 * Create the listen socket.
109	 */
110	if ((listensock = socket(PF_LOCAL, SOCK_STREAM, 0)) == -1)
111		err(1, "socket");
112
113	(void) unlink(SOCK_NAME);
114	(void) memset(&sun, 0, sizeof(sun));
115	sun.sun_family = AF_LOCAL;
116	(void) strcpy(sun.sun_path, SOCK_NAME);
117	sun.sun_len = SUN_LEN(&sun);
118
119	i = 1;
120	if (setsockopt(listensock, 0, LOCAL_CREDS, &i, sizeof(i)) == -1)
121		err(1, "setsockopt");
122
123	if (bind(listensock, (struct sockaddr *)&sun, sizeof(sun)) == -1)
124		err(1, "bind");
125
126	if (listen(listensock, 1) == -1)
127		err(1, "listen");
128
129	/*
130	 * Create the sender.
131	 */
132	(void) signal(SIGCHLD, catch_sigchld);
133	pid = fork();
134	switch (pid) {
135	case -1:
136		err(1, "fork");
137		/* NOTREACHED */
138
139	case 0:
140		child();
141		/* NOTREACHED */
142	}
143
144	/*
145	 * Wait for the sender to connect.
146	 */
147	if ((sock = accept(listensock, (struct sockaddr *)&csun,
148	    &csunlen)) == -1)
149		err(1, "accept");
150
151	/*
152	 * Give sender a chance to run.  We will get going again
153	 * once the SIGCHLD arrives.
154	 */
155	(void) sleep(10);
156
157	/*
158	 * Grab the descriptors and credentials passed to us.
159	 */
160	(void) memset(&msg, 0, sizeof(msg));
161	msg.msg_control = (caddr_t) &message;
162	msg.msg_controllen = sizeof(message);
163
164	if (recvmsg(sock, &msg, 0) < 0)
165		err(1, "recvmsg");
166
167	(void) close(sock);
168
169	if (msg.msg_controllen == 0)
170		errx(1, "no control messages received");
171
172	if (msg.msg_flags & MSG_CTRUNC)
173		errx(1, "lost control message data");
174
175	cmp = CMSG_FIRSTHDR(&msg);
176	for (cmp = CMSG_FIRSTHDR(&msg); cmp != NULL;
177	    cmp = CMSG_NXTHDR(&msg, cmp)) {
178		if (cmp->cmsg_level != SOL_SOCKET)
179			errx(1, "bad control message level %d",
180			    cmp->cmsg_level);
181
182		switch (cmp->cmsg_type) {
183		case SCM_RIGHTS:
184			if (cmp->cmsg_len != sizeof(message.fdcm))
185				errx(1, "bad fd control message length");
186
187			files = (int *)CMSG_DATA(cmp);
188			break;
189
190		case SCM_CREDS:
191			if (cmp->cmsg_len < sizeof(struct sockcred))
192				errx(1, "bad cred control message length");
193
194			sc = (struct sockcred *)CMSG_DATA(cmp);
195			break;
196
197		default:
198			errx(1, "unexpected control message");
199			/* NOTREACHED */
200		}
201	}
202
203	/*
204	 * Read the files and print their contents.
205	 */
206	if (files == NULL)
207		warnx("didn't get fd control message");
208	else {
209		for (i = 0; i < 2; i++) {
210			(void) memset(buf, 0, sizeof(buf));
211			if (read(files[i], buf, sizeof(buf)) <= 0)
212				err(1, "read file %d", i + 1);
213			printf("%s", buf);
214		}
215	}
216
217	/*
218	 * Double-check credentials.
219	 */
220	if (sc == NULL)
221		warnx("didn't get cred control message");
222	else {
223		if (sc->sc_uid == getuid() &&
224		    sc->sc_euid == geteuid() &&
225		    sc->sc_gid == getgid() &&
226		    sc->sc_egid == getegid())
227			printf("Credentials match.\n");
228		else
229			printf("Credentials do NOT match.\n");
230	}
231
232	/*
233	 * All done!
234	 */
235	exit(0);
236}
237
238void
239catch_sigchld(sig)
240	int sig;
241{
242	int status;
243
244	(void) wait(&status);
245}
246
247void
248child()
249{
250	struct msghdr msg;
251	char fname[16], buf[64];
252	struct cmsghdr *cmp;
253	struct fdcmessage fdcm;
254	int i, fd, sock;
255	struct sockaddr_un sun;
256
257	/*
258	 * Create socket and connect to the receiver.
259	 */
260	if ((sock = socket(PF_LOCAL, SOCK_STREAM, 0)) == -1)
261		errx(1, "child socket");
262
263	(void) memset(&sun, 0, sizeof(sun));
264	sun.sun_family = AF_LOCAL;
265	(void) strcpy(sun.sun_path, SOCK_NAME);
266	sun.sun_len = SUN_LEN(&sun);
267
268	if (connect(sock, (struct sockaddr *)&sun, sizeof(sun)) == -1)
269		err(1, "child connect");
270
271	/*
272	 * Open the files again, and pass them to the child over the socket.
273	 */
274	for (i = 0; i < 2; i++) {
275		(void) sprintf(fname, "file%d", i + 1);
276		if ((fd = open(fname, O_RDONLY, 0666)) == -1)
277			err(1, "child open %s", fname);
278		fdcm.files[i] = fd;
279	}
280
281	(void) memset(&msg, 0, sizeof(msg));
282	msg.msg_control = (caddr_t) &fdcm;
283	msg.msg_controllen = sizeof(fdcm);
284
285	cmp = CMSG_FIRSTHDR(&msg);
286	cmp->cmsg_len = sizeof(fdcm);
287	cmp->cmsg_level = SOL_SOCKET;
288	cmp->cmsg_type = SCM_RIGHTS;
289
290	if (sendmsg(sock, &msg, 0))
291		err(1, "child sendmsg");
292
293	/*
294	 * All done!
295	 */
296	exit(0);
297}
298