xref: /openbsd-src/usr.bin/tmux/job.c (revision 1ad61ae0a79a724d2d3ec69e69c8e1d1ff6b53a0)
1 /* $OpenBSD: job.c,v 1.67 2022/02/01 12:05:42 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 	sigfillset(&set);
96 	sigprocmask(SIG_BLOCK, &set, &oldset);
97 
98 	if (flags & JOB_PTY) {
99 		memset(&ws, 0, sizeof ws);
100 		ws.ws_col = sx;
101 		ws.ws_row = sy;
102 		pid = fdforkpty(ptm_fd, &master, tty, NULL, &ws);
103 	} else {
104 		if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, out) != 0)
105 			goto fail;
106 		pid = fork();
107 	}
108 	if (cmd == NULL) {
109 		cmd_log_argv(argc, argv, "%s:", __func__);
110 		log_debug("%s: cwd=%s", __func__, cwd == NULL ? "" : cwd);
111 	} else {
112 		log_debug("%s: cmd=%s, cwd=%s", __func__, cmd,
113 		    cwd == NULL ? "" : cwd);
114 	}
115 
116 	switch (pid) {
117 	case -1:
118 		if (~flags & JOB_PTY) {
119 			close(out[0]);
120 			close(out[1]);
121 		}
122 		goto fail;
123 	case 0:
124 		proc_clear_signals(server_proc, 1);
125 		sigprocmask(SIG_SETMASK, &oldset, NULL);
126 
127 		if ((cwd == NULL || chdir(cwd) != 0) &&
128 		    ((home = find_home()) == NULL || chdir(home) != 0) &&
129 		    chdir("/") != 0)
130 			fatal("chdir failed");
131 
132 		environ_push(env);
133 		environ_free(env);
134 
135 		if (~flags & JOB_PTY) {
136 			if (dup2(out[1], STDIN_FILENO) == -1)
137 				fatal("dup2 failed");
138 			if (dup2(out[1], STDOUT_FILENO) == -1)
139 				fatal("dup2 failed");
140 			if (out[1] != STDIN_FILENO && out[1] != STDOUT_FILENO)
141 				close(out[1]);
142 			close(out[0]);
143 
144 			nullfd = open(_PATH_DEVNULL, O_RDWR);
145 			if (nullfd == -1)
146 				fatal("open failed");
147 			if (dup2(nullfd, STDERR_FILENO) == -1)
148 				fatal("dup2 failed");
149 			if (nullfd != STDERR_FILENO)
150 				close(nullfd);
151 		}
152 		closefrom(STDERR_FILENO + 1);
153 
154 		if (cmd != NULL) {
155 			execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
156 			fatal("execl failed");
157 		} else {
158 			argvp = cmd_copy_argv(argc, argv);
159 			execvp(argvp[0], argvp);
160 			fatal("execvp failed");
161 		}
162 	}
163 
164 	sigprocmask(SIG_SETMASK, &oldset, NULL);
165 	environ_free(env);
166 
167 	job = xmalloc(sizeof *job);
168 	job->state = JOB_RUNNING;
169 	job->flags = flags;
170 
171 	if (cmd != NULL)
172 		job->cmd = xstrdup(cmd);
173 	else
174 		job->cmd = cmd_stringify_argv(argc, argv);
175 	job->pid = pid;
176 	strlcpy(job->tty, tty, sizeof job->tty);
177 	job->status = 0;
178 
179 	LIST_INSERT_HEAD(&all_jobs, job, entry);
180 
181 	job->updatecb = updatecb;
182 	job->completecb = completecb;
183 	job->freecb = freecb;
184 	job->data = data;
185 
186 	if (~flags & JOB_PTY) {
187 		close(out[1]);
188 		job->fd = out[0];
189 	} else
190 		job->fd = master;
191 	setblocking(job->fd, 0);
192 
193 	job->event = bufferevent_new(job->fd, job_read_callback,
194 	    job_write_callback, job_error_callback, job);
195 	if (job->event == NULL)
196 		fatalx("out of memory");
197 	bufferevent_enable(job->event, EV_READ|EV_WRITE);
198 
199 	log_debug("run job %p: %s, pid %ld", job, job->cmd, (long) job->pid);
200 	return (job);
201 
202 fail:
203 	sigprocmask(SIG_SETMASK, &oldset, NULL);
204 	environ_free(env);
205 	return (NULL);
206 }
207 
208 /* Take job's file descriptor and free the job. */
209 int
210 job_transfer(struct job *job, pid_t *pid, char *tty, size_t ttylen)
211 {
212 	int	fd = job->fd;
213 
214 	log_debug("transfer job %p: %s", job, job->cmd);
215 
216 	if (pid != NULL)
217 		*pid = job->pid;
218 	if (tty != NULL)
219 		strlcpy(tty, job->tty, ttylen);
220 
221 	LIST_REMOVE(job, entry);
222 	free(job->cmd);
223 
224 	if (job->freecb != NULL && job->data != NULL)
225 		job->freecb(job->data);
226 
227 	if (job->event != NULL)
228 		bufferevent_free(job->event);
229 
230 	free(job);
231 	return (fd);
232 }
233 
234 /* Kill and free an individual job. */
235 void
236 job_free(struct job *job)
237 {
238 	log_debug("free job %p: %s", job, job->cmd);
239 
240 	LIST_REMOVE(job, entry);
241 	free(job->cmd);
242 
243 	if (job->freecb != NULL && job->data != NULL)
244 		job->freecb(job->data);
245 
246 	if (job->pid != -1)
247 		kill(job->pid, SIGTERM);
248 	if (job->event != NULL)
249 		bufferevent_free(job->event);
250 	if (job->fd != -1)
251 		close(job->fd);
252 
253 	free(job);
254 }
255 
256 /* Resize job. */
257 void
258 job_resize(struct job *job, u_int sx, u_int sy)
259 {
260 	struct winsize	 ws;
261 
262 	if (job->fd == -1 || (~job->flags & JOB_PTY))
263 		return;
264 
265 	log_debug("resize job %p: %ux%u", job, sx, sy);
266 
267 	memset(&ws, 0, sizeof ws);
268 	ws.ws_col = sx;
269 	ws.ws_row = sy;
270 	if (ioctl(job->fd, TIOCSWINSZ, &ws) == -1)
271 		fatal("ioctl failed");
272 }
273 
274 /* Job buffer read callback. */
275 static void
276 job_read_callback(__unused struct bufferevent *bufev, void *data)
277 {
278 	struct job	*job = data;
279 
280 	if (job->updatecb != NULL)
281 		job->updatecb(job);
282 }
283 
284 /*
285  * Job buffer write callback. Fired when the buffer falls below watermark
286  * (default is empty). If all the data has been written, disable the write
287  * event.
288  */
289 static void
290 job_write_callback(__unused struct bufferevent *bufev, void *data)
291 {
292 	struct job	*job = data;
293 	size_t		 len = EVBUFFER_LENGTH(EVBUFFER_OUTPUT(job->event));
294 
295 	log_debug("job write %p: %s, pid %ld, output left %zu", job, job->cmd,
296 	    (long) job->pid, len);
297 
298 	if (len == 0 && (~job->flags & JOB_KEEPWRITE)) {
299 		shutdown(job->fd, SHUT_WR);
300 		bufferevent_disable(job->event, EV_WRITE);
301 	}
302 }
303 
304 /* Job buffer error callback. */
305 static void
306 job_error_callback(__unused struct bufferevent *bufev, __unused short events,
307     void *data)
308 {
309 	struct job	*job = data;
310 
311 	log_debug("job error %p: %s, pid %ld", job, job->cmd, (long) job->pid);
312 
313 	if (job->state == JOB_DEAD) {
314 		if (job->completecb != NULL)
315 			job->completecb(job);
316 		job_free(job);
317 	} else {
318 		bufferevent_disable(job->event, EV_READ);
319 		job->state = JOB_CLOSED;
320 	}
321 }
322 
323 /* Job died (waitpid() returned its pid). */
324 void
325 job_check_died(pid_t pid, int status)
326 {
327 	struct job	*job;
328 
329 	LIST_FOREACH(job, &all_jobs, entry) {
330 		if (pid == job->pid)
331 			break;
332 	}
333 	if (job == NULL)
334 		return;
335 	if (WIFSTOPPED(status)) {
336 		if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU)
337 			return;
338 		killpg(job->pid, SIGCONT);
339 		return;
340 	}
341 	log_debug("job died %p: %s, pid %ld", job, job->cmd, (long) job->pid);
342 
343 	job->status = status;
344 
345 	if (job->state == JOB_CLOSED) {
346 		if (job->completecb != NULL)
347 			job->completecb(job);
348 		job_free(job);
349 	} else {
350 		job->pid = -1;
351 		job->state = JOB_DEAD;
352 	}
353 }
354 
355 /* Get job status. */
356 int
357 job_get_status(struct job *job)
358 {
359 	return (job->status);
360 }
361 
362 /* Get job data. */
363 void *
364 job_get_data(struct job *job)
365 {
366 	return (job->data);
367 }
368 
369 /* Get job event. */
370 struct bufferevent *
371 job_get_event(struct job *job)
372 {
373 	return (job->event);
374 }
375 
376 /* Kill all jobs. */
377 void
378 job_kill_all(void)
379 {
380 	struct job	*job;
381 
382 	LIST_FOREACH(job, &all_jobs, entry) {
383 		if (job->pid != -1)
384 			kill(job->pid, SIGTERM);
385 	}
386 }
387 
388 /* Are any jobs still running? */
389 int
390 job_still_running(void)
391 {
392 	struct job	*job;
393 
394 	LIST_FOREACH(job, &all_jobs, entry) {
395 		if ((~job->flags & JOB_NOWAIT) && job->state == JOB_RUNNING)
396 			return (1);
397 	}
398 	return (0);
399 }
400 
401 /* Print job summary. */
402 void
403 job_print_summary(struct cmdq_item *item, int blank)
404 {
405 	struct job	*job;
406 	u_int		 n = 0;
407 
408 	LIST_FOREACH(job, &all_jobs, entry) {
409 		if (blank) {
410 			cmdq_print(item, "%s", "");
411 			blank = 0;
412 		}
413 		cmdq_print(item, "Job %u: %s [fd=%d, pid=%ld, status=%d]",
414 		    n, job->cmd, job->fd, (long)job->pid, job->status);
415 		n++;
416 	}
417 }
418