1 /*
2  *   Copyright (C) Bull S.A. 1996
3  *   Copyright (c) International Business Machines  Corp., 2001
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18  */
19 /*---------------------------------------------------------------------+
20 |                          signal_test_02                              |
21 | ==================================================================== |
22 |                                                                      |
23 | Description:  Simplistic test to verify the signal system function   |
24 |               calls:                                                 |
25 |                                                                      |
26 |               o  Setup a signal-catching function for every possible |
27 |                  signal.                                             |
28 |               o  Send signals to the process and verify that they    |
29 |                  were received by the signal-catching function.      |
30 |               o  Block a few signals by changing the process signal  |
31 |                  mask.  Send signals to the process and verify that  |
32 |                  they indeed were blocked.                           |
33 |               o  Add additional signals to the process signal mask.  |
34 |                  Verify that they were blocked too.                  |
35 |               o  Change the process signal mask to unblock one       |
36 |                  signal and suspend execution of the process until   |
37 |                  the signal is received.  Verify that the unblocked  |
38 |                  signal is received.                                 |
39 |                                                                      |
40 | System calls: The following system calls are tested:                 |
41 |                                                                      |
42 |               sigprocmask () - Sets the current signal mask          |
43 |               sigemptyset () - Creates and manipulates signal masks  |
44 |               sigfillset () - Creates and manipulates signal masks   |
45 |               sigaddset () - Creates and manipulates signal masks    |
46 |               sigdelset () - Creates and manipulates signal masks    |
47 |               sigsuspend () - Atomically changes the set of blocked  |
48 |                               signals and waits for a signal         |
49 |               sigaction () - Specifies the action to take upon       |
50 |                              delivery of a signal                    |
51 |               kill () - Sends a signal to a process                  |
52 |                                                                      |
53 | Usage:        signal_test_03                                         |
54 |                                                                      |
55 | To compile:   cc -o signal_test_03 signal_test_03                    |
56 |                                                                      |
57 | Last update:   Ver. 1.2, 2/7/94 23:17:48                             |
58 |                                                                      |
59 | Change Activity                                                      |
60 |                                                                      |
61 |   Version  Date    Name  Reason                                      |
62 |    0.1     050689  CTU   Initial version                             |
63 |    0.2     112293  DJK   Rewrite for AIX version 4.1                 |
64 |    1.2     020794  DJK   Move to "prod" directory                    |
65 |    1.3     060501  VHM   Port to work in linux                       |
66 |                                                                      |
67 +---------------------------------------------------------------------*/
68 
69 #define SIGMAX 64		/* What should this number really be? _NSIG from bits/signum.h maybe? */
70 
71 #include <stdio.h>
72 #include <stdlib.h>
73 #include <errno.h>
74 #include <signal.h>
75 #include <string.h>
76 #include <unistd.h>
77 #include <sys/types.h>
78 
79 /* Macro for specifying signal masks */
80 #define MASK(sig)  (1 << ((sig) - 1))
81 
82 #include "signals.h"
83 
84 /* Function prototypes */
85 void init_sig();
86 void handler(int sig);		//, int code, struct sigcontext *);
87 void reset_valid_sig();
88 void sys_error(const char *, int);
89 void error(const char *, int);
90 
91 /* Define an array for verifying received signals */
92 int valid_sig[SIGMAX + 1];
93 
94 /*---------------------------------------------------------------------+
95 |                               main ()                                |
96 | ==================================================================== |
97 |                                                                      |
98 | Function:  Main program  (see prolog for more details)               |
99 |                                                                      |
100 +---------------------------------------------------------------------*/
main(int argc,char ** argv)101 int main(int argc, char **argv)
102 {
103 	sigset_t setsig,	/* Initial signal mask */
104 	 newsetsig;		/* Second signal mask */
105 	pid_t pid = getpid();	/* Process ID (of this process) */
106 
107 	/* Print out program header */
108 	printf("%s: IPC TestSuite program\n\n", *argv);
109 
110 	/*
111 	 * Establish signal handler for each signal & reset "valid signals"
112 	 * array
113 	 */
114 	init_sig();
115 	reset_valid_sig();
116 
117 	sigemptyset(&setsig);
118 	if (sigprocmask(SIG_SETMASK, &setsig, NULL) < 0)
119 		sys_error("sigprocmask failed", __LINE__);
120 
121 	/*
122 	 * Send SIGILL, SIGALRM & SIGIOT signals to this process:
123 	 *
124 	 * First indicate which signals the signal handler should expect
125 	 * by setting the corresponding valid_sig[] array fields.
126 	 *
127 	 * Then send the signals to this process.
128 	 *
129 	 * And finally verify that the signals were caught by the signal
130 	 * handler by checking to see if the corresponding valid_sig[] array
131 	 * fields were reset.
132 	 */
133 	printf("\tSend SIGILL, SIGALRM, SIGIOT signals to process\n");
134 	valid_sig[SIGILL] = 1;
135 	valid_sig[SIGALRM] = 1;
136 	valid_sig[SIGIOT] = 1;
137 
138 	kill(pid, SIGILL);
139 	kill(pid, SIGALRM);
140 	kill(pid, SIGIOT);
141 
142 	if (valid_sig[SIGILL])
143 		error("failed to receive SIGILL signal!", __LINE__);
144 	if (valid_sig[SIGALRM])
145 		error("failed to receive SIGALRM signal!", __LINE__);
146 	if (valid_sig[SIGIOT])
147 		error("failed to receive SIGIOT signal!", __LINE__);
148 
149 	/*
150 	 * Block SIGILL, SIGALRM & SIGIOT signals:
151 	 *
152 	 * First initialize the signal set so that all signals are excluded,
153 	 * then individually add the signals to block to the signal set.
154 	 *
155 	 * Then change the process signal mask with sigprocmask (SIG_SETMASK).
156 	 *
157 	 * Verify that the desired signals are blocked from interrupting the
158 	 * process, by sending both blocked and unblocked signals to the
159 	 * process.  Only the unblocked signals should interrupt the process.
160 	 */
161 	printf("\n\tBlock SIGILL, SIGALRM, SIGIOT signals, "
162 	       "and resend signals + others\n");
163 	sigemptyset(&setsig);
164 
165 	if (sigaddset(&setsig, SIGIOT) < 0)
166 		sys_error("sigaddset (SIGIOT) failed", __LINE__);
167 	if (sigaddset(&setsig, SIGILL) < 0)
168 		sys_error("sigaddset (SIGILL) failed", __LINE__);
169 	if (sigaddset(&setsig, SIGALRM) < 0)
170 		sys_error("sigaddset (SIGALRM) failed", __LINE__);
171 
172 	if (sigprocmask(SIG_SETMASK, &setsig, NULL) < 0)
173 		sys_error("sigaddset (SIGALRM) failed", __LINE__);
174 
175 	valid_sig[SIGFPE] = 1;
176 	valid_sig[SIGTERM] = 1;
177 	valid_sig[SIGINT] = 1;
178 
179 	kill(pid, SIGILL);
180 	kill(pid, SIGALRM);
181 	kill(pid, SIGIOT);
182 	kill(pid, SIGFPE);
183 	kill(pid, SIGTERM);
184 	kill(pid, SIGINT);
185 
186 	if (valid_sig[SIGFPE])
187 		sys_error("failed to receive SIGFPE signal!", __LINE__);
188 	if (valid_sig[SIGTERM])
189 		sys_error("failed to receive SIGTERM signal!", __LINE__);
190 	if (valid_sig[SIGINT])
191 		sys_error("failed to receive SIGINT signal!", __LINE__);
192 
193 	/*
194 	 * Block additional SIGFPE, SIGTERM & SIGINT signals:
195 	 *
196 	 * Create an other signal set to contain the additional signals to block
197 	 * and add the signals to block to the signal set.
198 	 *
199 	 * Change the process signal mask to block the additional signals
200 	 * with the sigprocmask (SIG_BLOCK) function.
201 	 *
202 	 * Verify that all of the desired signals are now blocked from
203 	 * interrupting the process.  None of the specified signals should
204 	 * interrupt the process until the process signal mask is changed.
205 	 */
206 	printf("\n\tBlock rest of signals\n");
207 	sigemptyset(&newsetsig);
208 
209 	sigaddset(&newsetsig, SIGFPE);
210 	sigaddset(&newsetsig, SIGTERM);
211 	sigaddset(&newsetsig, SIGINT);
212 
213 	if (sigprocmask(SIG_BLOCK, &newsetsig, &setsig) < 0)
214 		sys_error("sigprocmask failed", __LINE__);
215 
216 	kill(pid, SIGILL);
217 	kill(pid, SIGALRM);
218 	kill(pid, SIGIOT);
219 	kill(pid, SIGFPE);
220 	kill(pid, SIGTERM);
221 	kill(pid, SIGINT);
222 
223 	/*
224 	 * Wait two seconds just to make sure that none of the specified
225 	 * signals interrupt the process (They should all be blocked).
226 	 */
227 	sleep(2);
228 
229 	/*
230 	 * Change the process signal mask:
231 	 *
232 	 * Now specifiy a new process signal set to allow the SIGINT signal
233 	 * to interrupt the process.  Create the signal set by initializing
234 	 * the signal set with sigfillset () so that all signals are included
235 	 * in the signal set, then remove the SIGINT signal from the set with
236 	 * sigdelset ().
237 	 *
238 	 * Force the  process to suspend execution until delivery of an
239 	 * unblocked signal (SIGINT in this case) with sigsuspend ().
240 	 *
241 	 * Additionally, verify that the SIGINT signal was received.
242 	 */
243 	valid_sig[SIGINT] = 1;
244 
245 	printf
246 	    ("\n\tChange signal mask & wait until signal interrupts process\n");
247 	if (sigfillset(&setsig) < 0)
248 		sys_error("sigfillset failed", __LINE__);
249 	if (sigdelset(&setsig, SIGINT) < 0)
250 		sys_error("sigdelset failed", __LINE__);
251 	if (sigsuspend(&setsig) != -1 || errno != 4)
252 		sys_error("sigsuspend failed", __LINE__);
253 
254 	if (valid_sig[SIGINT])
255 		error("failed to receive SIGIOT signal!", __LINE__);
256 
257 	/* Program completed successfully -- exit */
258 	printf("\nsuccessful!\n");
259 
260 	return (0);
261 }
262 
263 /*---------------------------------------------------------------------+
264 |                             init_sig ()                              |
265 | ==================================================================== |
266 |                                                                      |
267 | Function:  Initialize the signal vector for ALL possible signals     |
268 |            (as defined in /usr/include/sys/signal.h) except for      |
269 |            the following signals which cannot be caught or ignored:  |
270 |                                                                      |
271 |              o  SIGKILL (9)                                          |
272 |              o  SIGSTOP (17)                                         |
273 |              o  SIGCONT (19)                                         |
274 |                                                                      |
275 | Returns:   n/a                                                       |
276 |                                                                      |
277 +---------------------------------------------------------------------*/
init_sig()278 void init_sig()
279 {
280 	struct sigaction invec;
281 	char msg[256];		/* Buffer for error message */
282 	int i;
283 
284 	for (i = 1; i <= SIGMAX; i++) {
285 
286 		/* Cannot catch or ignore the following signals */
287 #ifdef _IA64			/* SIGWAITING not supported, RESERVED */
288 		if ((i == SIGKILL) || (i == SIGSTOP) ||
289 		    (i == SIGCONT) || (i == SIGWAITING))
290 			continue;
291 #else
292 #ifdef _LINUX_
293 		if ((i == SIGKILL) || (i == SIGSTOP)
294 		    || ((i >= 32) && (i <= 34)))
295 			continue;
296 #else
297 		if (i == SIGKILL || i == SIGSTOP || i == SIGCONT)
298 			continue;
299 #endif
300 #endif
301 
302 		invec.sa_handler = (void (*)(int))handler;
303 		sigemptyset(&invec.sa_mask);
304 		invec.sa_flags = 0;
305 
306 		if (sigaction(i, &invec, NULL) < 0) {
307 			sprintf(msg, "sigaction failed on signal %d", i);
308 			error(msg, __LINE__);
309 		}
310 	}
311 }
312 
313 /*---------------------------------------------------------------------+
314 |                             handler ()                               |
315 | ==================================================================== |
316 |                                                                      |
317 | Function:  Signal catching function.  As specified in init_sig_vec() |
318 |            this function is automatically called each time a signal  |
319 |            is received by the process.                               |
320 |                                                                      |
321 |            Once receiving the signal, verify that the corresponding  |
322 |            signal was expected.                                      |
323 |                                                                      |
324 | Returns:   Aborts program if an unexpected signal was received.      |
325 |                                                                      |
326 +---------------------------------------------------------------------*/
handler(int sig)327 void handler(int sig)		//, int code, struct sigcontext *scp)
328 {
329 	char msg[256];
330 
331 	/* Check to insure that expected signal was received */
332 	if (valid_sig[sig]) {
333 		valid_sig[sig] = 0;
334 		printf("\treceived signal: (%s)\n", signames[sig]);
335 	} else {
336 		sprintf(msg, "unexpected signal (%d,%s)", sig,
337 			(sig < 32) ? signames[sig] : "unknown signal");
338 		error(msg, __LINE__);
339 	}
340 }
341 
342 /*---------------------------------------------------------------------+
343 |                         reset_valid_sig ()                           |
344 | ==================================================================== |
345 |                                                                      |
346 | Function:  Reset the valid "signal" array                            |
347 |                                                                      |
348 | Returns:   n/a                                                       |
349 |                                                                      |
350 +---------------------------------------------------------------------*/
reset_valid_sig()351 void reset_valid_sig()
352 {
353 	int i;
354 
355 	for (i = 0; i < (SIGMAX + 1); i++)
356 		valid_sig[i] = 0;
357 }
358 
359 /*---------------------------------------------------------------------+
360 |                             sys_error ()                             |
361 | ==================================================================== |
362 |                                                                      |
363 | Function:  Creates system error message and calls error ()           |
364 |                                                                      |
365 +---------------------------------------------------------------------*/
sys_error(const char * msg,int line)366 void sys_error(const char *msg, int line)
367 {
368 	char syserr_msg[256];
369 
370 	sprintf(syserr_msg, "%s: %s\n", msg, strerror(errno));
371 	error(syserr_msg, line);
372 }
373 
374 /*---------------------------------------------------------------------+
375 |                               error ()                               |
376 | ==================================================================== |
377 |                                                                      |
378 | Function:  Prints out message and exits...                           |
379 |                                                                      |
380 +---------------------------------------------------------------------*/
error(const char * msg,int line)381 void error(const char *msg, int line)
382 {
383 	fprintf(stderr, "ERROR [line: %d] %s\n", line, msg);
384 	exit(-1);
385 }
386