xref: /openbsd-src/usr.bin/tmux/job.c (revision 4e1ee0786f11cc571bd0be17d38e46f635c719fc)
1 /* $OpenBSD: job.c,v 1.65 2021/10/11 10:55:30 nicm Exp $ */
2 
3 /*
4  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/ioctl.h>
21 #include <sys/socket.h>
22 #include <sys/wait.h>
23 
24 #include <fcntl.h>
25 #include <paths.h>
26 #include <signal.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30 #include <util.h>
31 
32 #include "tmux.h"
33 
34 /*
35  * Job scheduling. Run queued commands in the background and record their
36  * output.
37  */
38 
39 static void	job_read_callback(struct bufferevent *, void *);
40 static void	job_write_callback(struct bufferevent *, void *);
41 static void	job_error_callback(struct bufferevent *, short, void *);
42 
43 /* A single job. */
44 struct job {
45 	enum {
46 		JOB_RUNNING,
47 		JOB_DEAD,
48 		JOB_CLOSED
49 	} state;
50 
51 	int			 flags;
52 
53 	char			*cmd;
54 	pid_t			 pid;
55 	char		         tty[TTY_NAME_MAX];
56 	int			 status;
57 
58 	int			 fd;
59 	struct bufferevent	*event;
60 
61 	job_update_cb		 updatecb;
62 	job_complete_cb		 completecb;
63 	job_free_cb		 freecb;
64 	void			*data;
65 
66 	LIST_ENTRY(job)		 entry;
67 };
68 
69 /* All jobs list. */
70 static LIST_HEAD(joblist, job) all_jobs = LIST_HEAD_INITIALIZER(all_jobs);
71 
72 /* Start a job running. */
73 struct job *
74 job_run(const char *cmd, int argc, char **argv, struct environ *e, struct session *s,
75     const char *cwd, job_update_cb updatecb, job_complete_cb completecb,
76     job_free_cb freecb, void *data, int flags, int sx, int sy)
77 {
78 	struct job	 *job;
79 	struct environ	 *env;
80 	pid_t		  pid;
81 	int		  nullfd, out[2], master;
82 	const char	 *home;
83 	sigset_t	  set, oldset;
84 	struct winsize	  ws;
85 	char		**argvp, tty[TTY_NAME_MAX];
86 
87 	/*
88 	 * Do not set TERM during .tmux.conf, it is nice to be able to use
89 	 * if-shell to decide on default-terminal based on outside TERM.
90 	 */
91 	env = environ_for_session(s, !cfg_finished);
92 	if (e != NULL) {
93 		environ_copy(e, env);
94 	}
95 
96 	sigfillset(&set);
97 	sigprocmask(SIG_BLOCK, &set, &oldset);
98 
99 	if (flags & JOB_PTY) {
100 		memset(&ws, 0, sizeof ws);
101 		ws.ws_col = sx;
102 		ws.ws_row = sy;
103 		pid = fdforkpty(ptm_fd, &master, tty, NULL, &ws);
104 	} else {
105 		if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, out) != 0)
106 			goto fail;
107 		pid = fork();
108 	}
109 	if (cmd == NULL) {
110 		cmd_log_argv(argc, argv, "%s:", __func__);
111 		log_debug("%s: cwd=%s", __func__, cwd == NULL ? "" : cwd);
112 	} else {
113 		log_debug("%s: cmd=%s, cwd=%s", __func__, cmd,
114 		    cwd == NULL ? "" : cwd);
115 	}
116 
117 	switch (pid) {
118 	case -1:
119 		if (~flags & JOB_PTY) {
120 			close(out[0]);
121 			close(out[1]);
122 		}
123 		goto fail;
124 	case 0:
125 		proc_clear_signals(server_proc, 1);
126 		sigprocmask(SIG_SETMASK, &oldset, NULL);
127 
128 		if ((cwd == NULL || chdir(cwd) != 0) &&
129 		    ((home = find_home()) == NULL || chdir(home) != 0) &&
130 		    chdir("/") != 0)
131 			fatal("chdir failed");
132 
133 		environ_push(env);
134 		environ_free(env);
135 
136 		if (~flags & JOB_PTY) {
137 			if (dup2(out[1], STDIN_FILENO) == -1)
138 				fatal("dup2 failed");
139 			if (dup2(out[1], STDOUT_FILENO) == -1)
140 				fatal("dup2 failed");
141 			if (out[1] != STDIN_FILENO && out[1] != STDOUT_FILENO)
142 				close(out[1]);
143 			close(out[0]);
144 
145 			nullfd = open(_PATH_DEVNULL, O_RDWR, 0);
146 			if (nullfd == -1)
147 				fatal("open failed");
148 			if (dup2(nullfd, STDERR_FILENO) == -1)
149 				fatal("dup2 failed");
150 			if (nullfd != STDERR_FILENO)
151 				close(nullfd);
152 		}
153 		closefrom(STDERR_FILENO + 1);
154 
155 		if (cmd != NULL) {
156 			execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
157 			fatal("execl failed");
158 		} else {
159 			argvp = cmd_copy_argv(argc, argv);
160 			execvp(argvp[0], argvp);
161 			fatal("execvp failed");
162 		}
163 	}
164 
165 	sigprocmask(SIG_SETMASK, &oldset, NULL);
166 	environ_free(env);
167 
168 	job = xmalloc(sizeof *job);
169 	job->state = JOB_RUNNING;
170 	job->flags = flags;
171 
172 	if (cmd != NULL)
173 		job->cmd = xstrdup(cmd);
174 	else
175 		job->cmd = cmd_stringify_argv(argc, argv);
176 	job->pid = pid;
177 	strlcpy(job->tty, tty, sizeof job->tty);
178 	job->status = 0;
179 
180 	LIST_INSERT_HEAD(&all_jobs, job, entry);
181 
182 	job->updatecb = updatecb;
183 	job->completecb = completecb;
184 	job->freecb = freecb;
185 	job->data = data;
186 
187 	if (~flags & JOB_PTY) {
188 		close(out[1]);
189 		job->fd = out[0];
190 	} else
191 		job->fd = master;
192 	setblocking(job->fd, 0);
193 
194 	job->event = bufferevent_new(job->fd, job_read_callback,
195 	    job_write_callback, job_error_callback, job);
196 	if (job->event == NULL)
197 		fatalx("out of memory");
198 	bufferevent_enable(job->event, EV_READ|EV_WRITE);
199 
200 	log_debug("run job %p: %s, pid %ld", job, job->cmd, (long) job->pid);
201 	return (job);
202 
203 fail:
204 	sigprocmask(SIG_SETMASK, &oldset, NULL);
205 	environ_free(env);
206 	return (NULL);
207 }
208 
209 /* Take job's file descriptor and free the job. */
210 int
211 job_transfer(struct job *job, pid_t *pid, char *tty, size_t ttylen)
212 {
213 	int	fd = job->fd;
214 
215 	log_debug("transfer job %p: %s", job, job->cmd);
216 
217 	if (pid != NULL)
218 		*pid = job->pid;
219 	if (tty != NULL)
220 		strlcpy(tty, job->tty, ttylen);
221 
222 	LIST_REMOVE(job, entry);
223 	free(job->cmd);
224 
225 	if (job->freecb != NULL && job->data != NULL)
226 		job->freecb(job->data);
227 
228 	if (job->event != NULL)
229 		bufferevent_free(job->event);
230 
231 	free(job);
232 	return (fd);
233 }
234 
235 /* Kill and free an individual job. */
236 void
237 job_free(struct job *job)
238 {
239 	log_debug("free job %p: %s", job, job->cmd);
240 
241 	LIST_REMOVE(job, entry);
242 	free(job->cmd);
243 
244 	if (job->freecb != NULL && job->data != NULL)
245 		job->freecb(job->data);
246 
247 	if (job->pid != -1)
248 		kill(job->pid, SIGTERM);
249 	if (job->event != NULL)
250 		bufferevent_free(job->event);
251 	if (job->fd != -1)
252 		close(job->fd);
253 
254 	free(job);
255 }
256 
257 /* Resize job. */
258 void
259 job_resize(struct job *job, u_int sx, u_int sy)
260 {
261 	struct winsize	 ws;
262 
263 	if (job->fd == -1 || (~job->flags & JOB_PTY))
264 		return;
265 
266 	log_debug("resize job %p: %ux%u", job, sx, sy);
267 
268 	memset(&ws, 0, sizeof ws);
269 	ws.ws_col = sx;
270 	ws.ws_row = sy;
271 	if (ioctl(job->fd, TIOCSWINSZ, &ws) == -1)
272 		fatal("ioctl failed");
273 }
274 
275 /* Job buffer read callback. */
276 static void
277 job_read_callback(__unused struct bufferevent *bufev, void *data)
278 {
279 	struct job	*job = data;
280 
281 	if (job->updatecb != NULL)
282 		job->updatecb(job);
283 }
284 
285 /*
286  * Job buffer write callback. Fired when the buffer falls below watermark
287  * (default is empty). If all the data has been written, disable the write
288  * event.
289  */
290 static void
291 job_write_callback(__unused struct bufferevent *bufev, void *data)
292 {
293 	struct job	*job = data;
294 	size_t		 len = EVBUFFER_LENGTH(EVBUFFER_OUTPUT(job->event));
295 
296 	log_debug("job write %p: %s, pid %ld, output left %zu", job, job->cmd,
297 	    (long) job->pid, len);
298 
299 	if (len == 0 && (~job->flags & JOB_KEEPWRITE)) {
300 		shutdown(job->fd, SHUT_WR);
301 		bufferevent_disable(job->event, EV_WRITE);
302 	}
303 }
304 
305 /* Job buffer error callback. */
306 static void
307 job_error_callback(__unused struct bufferevent *bufev, __unused short events,
308     void *data)
309 {
310 	struct job	*job = data;
311 
312 	log_debug("job error %p: %s, pid %ld", job, job->cmd, (long) job->pid);
313 
314 	if (job->state == JOB_DEAD) {
315 		if (job->completecb != NULL)
316 			job->completecb(job);
317 		job_free(job);
318 	} else {
319 		bufferevent_disable(job->event, EV_READ);
320 		job->state = JOB_CLOSED;
321 	}
322 }
323 
324 /* Job died (waitpid() returned its pid). */
325 void
326 job_check_died(pid_t pid, int status)
327 {
328 	struct job	*job;
329 
330 	LIST_FOREACH(job, &all_jobs, entry) {
331 		if (pid == job->pid)
332 			break;
333 	}
334 	if (job == NULL)
335 		return;
336 	if (WIFSTOPPED(status)) {
337 		if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU)
338 			return;
339 		killpg(job->pid, SIGCONT);
340 		return;
341 	}
342 	log_debug("job died %p: %s, pid %ld", job, job->cmd, (long) job->pid);
343 
344 	job->status = status;
345 
346 	if (job->state == JOB_CLOSED) {
347 		if (job->completecb != NULL)
348 			job->completecb(job);
349 		job_free(job);
350 	} else {
351 		job->pid = -1;
352 		job->state = JOB_DEAD;
353 	}
354 }
355 
356 /* Get job status. */
357 int
358 job_get_status(struct job *job)
359 {
360 	return (job->status);
361 }
362 
363 /* Get job data. */
364 void *
365 job_get_data(struct job *job)
366 {
367 	return (job->data);
368 }
369 
370 /* Get job event. */
371 struct bufferevent *
372 job_get_event(struct job *job)
373 {
374 	return (job->event);
375 }
376 
377 /* Kill all jobs. */
378 void
379 job_kill_all(void)
380 {
381 	struct job	*job;
382 
383 	LIST_FOREACH(job, &all_jobs, entry) {
384 		if (job->pid != -1)
385 			kill(job->pid, SIGTERM);
386 	}
387 }
388 
389 /* Are any jobs still running? */
390 int
391 job_still_running(void)
392 {
393 	struct job	*job;
394 
395 	LIST_FOREACH(job, &all_jobs, entry) {
396 		if ((~job->flags & JOB_NOWAIT) && job->state == JOB_RUNNING)
397 			return (1);
398 	}
399 	return (0);
400 }
401 
402 /* Print job summary. */
403 void
404 job_print_summary(struct cmdq_item *item, int blank)
405 {
406 	struct job	*job;
407 	u_int		 n = 0;
408 
409 	LIST_FOREACH(job, &all_jobs, entry) {
410 		if (blank) {
411 			cmdq_print(item, "%s", "");
412 			blank = 0;
413 		}
414 		cmdq_print(item, "Job %u: %s [fd=%d, pid=%ld, status=%d]",
415 		    n, job->cmd, job->fd, (long)job->pid, job->status);
416 		n++;
417 	}
418 }
419