1 /* $NetBSD: t_kill.c,v 1.1 2011/07/07 06:57:53 jruoho Exp $ */
2 
3 /*-
4  * Copyright (c) 2011 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jukka Ruohonen.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 #include <sys/cdefs.h>
32 __RCSID("$NetBSD: t_kill.c,v 1.1 2011/07/07 06:57:53 jruoho Exp $");
33 
34 #include <sys/wait.h>
35 
36 #include <errno.h>
37 #include <limits.h>
38 #include <pwd.h>
39 #include <signal.h>
40 #include <stdlib.h>
41 #include <unistd.h>
42 
43 #include <atf-c.h>
44 
45 ATF_TC(kill_basic);
46 ATF_TC_HEAD(kill_basic, tc)
47 {
48 	atf_tc_set_md_var(tc, "descr", "Test that kill(2) works");
49 }
50 
51 ATF_TC_BODY(kill_basic, tc)
52 {
53 	const int sig[] = { SIGHUP, SIGINT, SIGKILL, SIGTERM };
54 	pid_t pid;
55 	size_t i;
56 	int sta;
57 
58 	for (i = 0; i < __arraycount(sig); i++) {
59 
60 		pid = fork();
61 		ATF_REQUIRE(pid >= 0);
62 
63 		switch (pid) {
64 
65 		case 0:
66 			pause();
67 			break;
68 
69 		default:
70 			ATF_REQUIRE(kill(pid, sig[i]) == 0);
71 		}
72 
73 		(void)wait(&sta);
74 
75 		if (WIFSIGNALED(sta) == 0 || WTERMSIG(sta) != sig[i])
76 			atf_tc_fail("kill(2) failed to kill child");
77 	}
78 }
79 
80 ATF_TC(kill_err);
81 ATF_TC_HEAD(kill_err, tc)
82 {
83 	atf_tc_set_md_var(tc, "descr", "Test error conditions of kill(2)");
84 }
85 
86 ATF_TC_BODY(kill_err, tc)
87 {
88 	int rv, sta;
89 	pid_t pid;
90 
91 	pid = fork();
92 	ATF_REQUIRE(pid >= 0);
93 
94 	if (pid == 0) {
95 
96 		errno = 0;
97 		rv = kill(getpid(), -1);
98 
99 		if (rv == 0 || errno != EINVAL)
100 			_exit(EINVAL);
101 
102 		errno = 0;
103 		rv = kill(INT_MAX, SIGUSR1);
104 
105 		if (rv == 0 || errno != ESRCH)
106 			_exit(ESRCH);
107 
108 		_exit(EXIT_SUCCESS);
109 	}
110 
111 	(void)wait(&sta);
112 
113 	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS) {
114 
115 		if (WEXITSTATUS(sta) == EINVAL)
116 			atf_tc_fail("expected EINVAL, but kill(2) succeeded");
117 
118 		if (WEXITSTATUS(sta) == ESRCH)
119 			atf_tc_fail("expected ESRCH, but kill(2) succeeded");
120 
121 		atf_tc_fail("unknown error from kill(2)");
122 	}
123 }
124 
125 ATF_TC(kill_perm);
126 ATF_TC_HEAD(kill_perm, tc)
127 {
128 	atf_tc_set_md_var(tc, "descr", "Test kill(2) permissions");
129 	atf_tc_set_md_var(tc, "require.user", "root");
130 }
131 
132 ATF_TC_BODY(kill_perm, tc)
133 {
134 	struct passwd *pw;
135 	pid_t cpid, ppid;
136 	uid_t cuid = 0;
137 	uid_t puid = 0;
138 	int sta;
139 
140 	/*
141 	 * Test that kill(2) fails when called
142 	 * for a PID owned by another user.
143 	 */
144 	pw = getpwnam("operator");
145 
146 	if (pw != NULL)
147 		cuid = pw->pw_uid;
148 
149 	pw = getpwnam("nobody");
150 
151 	if (pw != NULL)
152 		puid = pw->pw_uid;
153 
154 	if (cuid == 0 || puid == 0 || cuid == puid)
155 		atf_tc_fail("getpwnam(3) failed");
156 
157 	ppid = fork();
158 
159 	if (ppid < 0)
160 		_exit(EXIT_FAILURE);
161 
162 	if (ppid == 0) {
163 
164 		cpid = fork();
165 
166 		if (cpid < 0)
167 			_exit(EXIT_FAILURE);
168 
169 		if (cpid == 0) {
170 
171 			if (setuid(cuid) < 0)
172 				_exit(EXIT_FAILURE);
173 			else {
174 				(void)sleep(1);
175 			}
176 
177 			_exit(EXIT_SUCCESS);
178 		}
179 
180 		/*
181 		 * Try to kill the child after having
182 		 * set the real and effective UID.
183 		 */
184 		if (setuid(puid) != 0)
185 			_exit(EXIT_FAILURE);
186 
187 		errno = 0;
188 
189 		if (kill(cpid, SIGKILL) == 0)
190 			_exit(EPERM);
191 
192 		if (errno != EPERM)
193 			_exit(EPERM);
194 
195 		(void)waitpid(cpid, &sta, 0);
196 
197 		_exit(EXIT_SUCCESS);
198 	}
199 
200 	(void)waitpid(ppid, &sta, 0);
201 
202 	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) == EPERM)
203 		atf_tc_fail("killed a process of another user");
204 
205 	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
206 		atf_tc_fail("unknown error from kill(2)");
207 }
208 
209 ATF_TC(kill_pgrp_neg);
210 ATF_TC_HEAD(kill_pgrp_neg, tc)
211 {
212 	atf_tc_set_md_var(tc, "descr", "Test kill(2) with process group, #2");
213 }
214 
215 ATF_TC_BODY(kill_pgrp_neg, tc)
216 {
217 	const int maxiter = 3;
218 	pid_t cpid, ppid;
219 	int i, sta;
220 
221 	ppid = fork();
222 	ATF_REQUIRE(ppid >= 0);
223 
224 	if (ppid == 0) {
225 
226 		ATF_REQUIRE(setpgid(0, 0) == 0);
227 
228 		for (i = 0; i < maxiter; i++) {
229 
230 			cpid = fork();
231 			ATF_REQUIRE(cpid >= 0);
232 
233 			if (cpid == 0)
234 				pause();
235 		}
236 
237 		/*
238 		 * Test the variant of killpg(3); if the process number
239 		 * is negative but not -1, the signal should be sent to
240 		 * all processes whose process group ID is equal to the
241 		 * absolute value of the process number.
242 		 */
243 		ATF_REQUIRE(kill(-getpgrp(), SIGKILL) == 0);
244 
245 		(void)sleep(1);
246 
247 		_exit(EXIT_SUCCESS);
248 	}
249 
250 	(void)waitpid(ppid, &sta, 0);
251 
252 	if (WIFSIGNALED(sta) == 0 || WTERMSIG(sta) != SIGKILL)
253 		atf_tc_fail("failed to kill(2) a process group");
254 }
255 
256 ATF_TC(kill_pgrp_zero);
257 ATF_TC_HEAD(kill_pgrp_zero, tc)
258 {
259 	atf_tc_set_md_var(tc, "descr", "Test kill(2) with process group, #1");
260 }
261 
262 ATF_TC_BODY(kill_pgrp_zero, tc)
263 {
264 	const int maxiter = 3;
265 	pid_t cpid, ppid;
266 	int i, sta;
267 
268 	ppid = fork();
269 	ATF_REQUIRE(ppid >= 0);
270 
271 	if (ppid == 0) {
272 
273 		ATF_REQUIRE(setpgid(0, 0) == 0);
274 
275 		for (i = 0; i < maxiter; i++) {
276 
277 			cpid = fork();
278 			ATF_REQUIRE(cpid >= 0);
279 
280 			if (cpid == 0)
281 				pause();
282 		}
283 
284 		/*
285 		 * If the supplied process number is zero,
286 		 * the signal should be sent to all processes
287 		 * under the current process group.
288 		 */
289 		ATF_REQUIRE(kill(0, SIGKILL) == 0);
290 
291 		(void)sleep(1);
292 
293 		_exit(EXIT_SUCCESS);
294 	}
295 
296 	(void)waitpid(ppid, &sta, 0);
297 
298 	if (WIFSIGNALED(sta) == 0 || WTERMSIG(sta) != SIGKILL)
299 		atf_tc_fail("failed to kill(2) a process group");
300 }
301 
302 ATF_TP_ADD_TCS(tp)
303 {
304 
305 	ATF_TP_ADD_TC(tp, kill_basic);
306 	ATF_TP_ADD_TC(tp, kill_err);
307 	ATF_TP_ADD_TC(tp, kill_perm);
308 	ATF_TP_ADD_TC(tp, kill_pgrp_neg);
309 	ATF_TP_ADD_TC(tp, kill_pgrp_zero);
310 
311 	return atf_no_error();
312 }
313