xref: /openbsd-src/usr.bin/script/script.c (revision ae3cb403620ab940fbaabb3055fac045a63d56b7)
1 /*	$OpenBSD: script.c,v 1.33 2017/04/12 14:49:05 deraadt Exp $	*/
2 /*	$NetBSD: script.c,v 1.3 1994/12/21 08:55:43 jtc Exp $	*/
3 
4 /*
5  * Copyright (c) 2001 Theo de Raadt
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  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * Copyright (c) 1980, 1992, 1993
31  *	The Regents of the University of California.  All rights reserved.
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  * 1. Redistributions of source code must retain the above copyright
37  *    notice, this list of conditions and the following disclaimer.
38  * 2. Redistributions in binary form must reproduce the above copyright
39  *    notice, this list of conditions and the following disclaimer in the
40  *    documentation and/or other materials provided with the distribution.
41  * 3. Neither the name of the University nor the names of its contributors
42  *    may be used to endorse or promote products derived from this software
43  *    without specific prior written permission.
44  *
45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55  * SUCH DAMAGE.
56  */
57 
58 #include <sys/types.h>
59 #include <sys/wait.h>
60 #include <sys/stat.h>
61 #include <sys/ioctl.h>
62 #include <sys/time.h>
63 
64 #include <errno.h>
65 #include <fcntl.h>
66 #include <paths.h>
67 #include <signal.h>
68 #include <stdio.h>
69 #include <stdlib.h>
70 #include <string.h>
71 #include <termios.h>
72 #include <unistd.h>
73 
74 #include <util.h>
75 #include <err.h>
76 
77 FILE	*fscript;
78 int	master, slave;
79 volatile sig_atomic_t child;
80 pid_t	subchild;
81 char	*fname;
82 
83 volatile sig_atomic_t dead;
84 volatile sig_atomic_t sigdeadstatus;
85 volatile sig_atomic_t flush;
86 
87 struct	termios tt;
88 int		istty;
89 
90 __dead void done(int);
91 void dooutput(void);
92 void doshell(void);
93 void fail(void);
94 void finish(int);
95 void scriptflush(int);
96 void handlesigwinch(int);
97 
98 int
99 main(int argc, char *argv[])
100 {
101 	extern char *__progname;
102 	struct sigaction sa;
103 	struct winsize win;
104 	char ibuf[BUFSIZ];
105 	ssize_t cc, off;
106 	int aflg, ch;
107 
108 	aflg = 0;
109 	while ((ch = getopt(argc, argv, "a")) != -1)
110 		switch(ch) {
111 		case 'a':
112 			aflg = 1;
113 			break;
114 		default:
115 			fprintf(stderr, "usage: %s [-a] [file]\n", __progname);
116 			exit(1);
117 		}
118 	argc -= optind;
119 	argv += optind;
120 
121 	if (argc > 0)
122 		fname = argv[0];
123 	else
124 		fname = "typescript";
125 
126 	if ((fscript = fopen(fname, aflg ? "a" : "w")) == NULL)
127 		err(1, "%s", fname);
128 
129 	if (isatty(0)) {
130 		if (tcgetattr(STDIN_FILENO, &tt) == 0 &&
131 		    ioctl(STDIN_FILENO, TIOCGWINSZ, &win) == 0)
132 			istty = 1;
133 	}
134 	if (openpty(&master, &slave, NULL, &tt, &win) == -1)
135 		err(1, "openpty");
136 
137 	(void)printf("Script started, output file is %s\n", fname);
138 	if (istty) {
139 		struct termios rtt = tt;
140 
141 		cfmakeraw(&rtt);
142 		rtt.c_lflag &= ~ECHO;
143 		(void)tcsetattr(STDIN_FILENO, TCSAFLUSH, &rtt);
144 	}
145 
146 	bzero(&sa, sizeof sa);
147 	sigemptyset(&sa.sa_mask);
148 	sa.sa_handler = handlesigwinch;
149 	sa.sa_flags = SA_RESTART;
150 	(void)sigaction(SIGWINCH, &sa, NULL);
151 
152 	child = fork();
153 	if (child < 0) {
154 		warn("fork");
155 		fail();
156 	}
157 	if (child == 0) {
158 		subchild = child = fork();
159 		if (child < 0) {
160 			warn("fork");
161 			fail();
162 		}
163 		if (child)
164 			dooutput();
165 		else
166 			doshell();
167 	}
168 
169 	bzero(&sa, sizeof sa);
170 	sigemptyset(&sa.sa_mask);
171 	sa.sa_handler = finish;
172 	(void)sigaction(SIGCHLD, &sa, NULL);
173 
174 	if (pledge("stdio proc tty", NULL) == -1)
175 		err(1, "pledge");
176 
177 	(void)fclose(fscript);
178 	while (1) {
179 		if (dead)
180 			break;
181 		cc = read(STDIN_FILENO, ibuf, BUFSIZ);
182 		if (cc == -1 && errno == EINTR)
183 			continue;
184 		if (cc <= 0)
185 			break;
186 		for (off = 0; off < cc; ) {
187 			ssize_t n = write(master, ibuf + off, cc - off);
188 			if (n == -1 && errno != EAGAIN)
189 				break;
190 			if (n == 0)
191 				break;	/* skip writing */
192 			if (n > 0)
193 				off += n;
194 		}
195 	}
196 	done(sigdeadstatus);
197 }
198 
199 /* ARGSUSED */
200 void
201 finish(int signo)
202 {
203 	int save_errno = errno;
204 	int status, e = 1;
205 	pid_t pid;
206 
207 	while ((pid = wait3(&status, WNOHANG, 0)) > 0) {
208 		if (pid == (pid_t)child) {
209 			if (WIFEXITED(status))
210 				e = WEXITSTATUS(status);
211 		}
212 	}
213 	dead = 1;
214 	sigdeadstatus = e;
215 	errno = save_errno;
216 }
217 
218 /* ARGSUSED */
219 void
220 handlesigwinch(int signo)
221 {
222 	int save_errno = errno;
223 	struct winsize win;
224 	pid_t pgrp;
225 
226 	if (ioctl(STDIN_FILENO, TIOCGWINSZ, &win) != -1) {
227 		ioctl(slave, TIOCSWINSZ, &win);
228 		if (ioctl(slave, TIOCGPGRP, &pgrp) != -1)
229 			killpg(pgrp, SIGWINCH);
230 	}
231 	errno = save_errno;
232 }
233 
234 void
235 dooutput(void)
236 {
237 	struct sigaction sa;
238 	struct itimerval value;
239 	sigset_t blkalrm;
240 	char obuf[BUFSIZ];
241 	time_t tvec;
242 	ssize_t outcc = 0, cc, off;
243 
244 	(void)close(STDIN_FILENO);
245 	tvec = time(NULL);
246 	(void)fprintf(fscript, "Script started on %s", ctime(&tvec));
247 
248 	sigemptyset(&blkalrm);
249 	sigaddset(&blkalrm, SIGALRM);
250 	bzero(&sa, sizeof sa);
251 	sigemptyset(&sa.sa_mask);
252 	sa.sa_handler = scriptflush;
253 	(void)sigaction(SIGALRM, &sa, NULL);
254 
255 	bzero(&sa, sizeof sa);
256 	sigemptyset(&sa.sa_mask);
257 	sa.sa_handler = SIG_IGN;
258 	(void)sigaction(SIGCHLD, &sa, NULL);
259 
260 	if (pledge("stdio proc", NULL) == -1)
261 		err(1, "pledge");
262 
263 	value.it_interval.tv_sec = 30;
264 	value.it_interval.tv_usec = 0;
265 	value.it_value = value.it_interval;
266 	(void)setitimer(ITIMER_REAL, &value, NULL);
267 	for (;;) {
268 		if (flush) {
269 			if (outcc) {
270 				(void)fflush(fscript);
271 				outcc = 0;
272 			}
273 			flush = 0;
274 		}
275 		cc = read(master, obuf, sizeof (obuf));
276 		if (cc == -1 && errno == EINTR)
277 			continue;
278 		if (cc <= 0)
279 			break;
280 		sigprocmask(SIG_BLOCK, &blkalrm, NULL);
281 		for (off = 0; off < cc; ) {
282 			ssize_t n = write(STDOUT_FILENO, obuf + off, cc - off);
283 			if (n == -1 && errno != EAGAIN)
284 				break;
285 			if (n == 0)
286 				break;	/* skip writing */
287 			if (n > 0)
288 				off += n;
289 		}
290 		(void)fwrite(obuf, 1, cc, fscript);
291 		outcc += cc;
292 		sigprocmask(SIG_UNBLOCK, &blkalrm, NULL);
293 	}
294 	done(0);
295 }
296 
297 /* ARGSUSED */
298 void
299 scriptflush(int signo)
300 {
301 	flush = 1;
302 }
303 
304 void
305 doshell(void)
306 {
307 	char *shell;
308 
309 	shell = getenv("SHELL");
310 	if (shell == NULL)
311 		shell = _PATH_BSHELL;
312 
313 	(void)close(master);
314 	(void)fclose(fscript);
315 	login_tty(slave);
316 	execl(shell, shell, "-i", (char *)NULL);
317 	warn("%s", shell);
318 	fail();
319 }
320 
321 void
322 fail(void)
323 {
324 
325 	(void)kill(0, SIGTERM);
326 	done(1);
327 }
328 
329 void
330 done(int eval)
331 {
332 	time_t tvec;
333 
334 	if (subchild) {
335 		tvec = time(NULL);
336 		(void)fprintf(fscript,"\nScript done on %s", ctime(&tvec));
337 		(void)fclose(fscript);
338 		(void)close(master);
339 	} else {
340 		if (istty)
341 			(void)tcsetattr(STDIN_FILENO, TCSAFLUSH, &tt);
342 		(void)printf("Script done, output file is %s\n", fname);
343 	}
344 	exit(eval);
345 }
346