xref: /openbsd-src/usr.bin/tmux/job.c (revision 824adb5411e4389b29bae28eba5c2c2bbd147f34)
1 /* $OpenBSD: job.c,v 1.64 2021/10/05 12:49:37 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 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 
93 	sigfillset(&set);
94 	sigprocmask(SIG_BLOCK, &set, &oldset);
95 
96 	if (flags & JOB_PTY) {
97 		memset(&ws, 0, sizeof ws);
98 		ws.ws_col = sx;
99 		ws.ws_row = sy;
100 		pid = fdforkpty(ptm_fd, &master, tty, NULL, &ws);
101 	} else {
102 		if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, out) != 0)
103 			goto fail;
104 		pid = fork();
105 	}
106 	if (cmd == NULL) {
107 		cmd_log_argv(argc, argv, "%s:", __func__);
108 		log_debug("%s: cwd=%s", __func__, cwd == NULL ? "" : cwd);
109 	} else {
110 		log_debug("%s: cmd=%s, cwd=%s", __func__, cmd,
111 		    cwd == NULL ? "" : cwd);
112 	}
113 
114 	switch (pid) {
115 	case -1:
116 		if (~flags & JOB_PTY) {
117 			close(out[0]);
118 			close(out[1]);
119 		}
120 		goto fail;
121 	case 0:
122 		proc_clear_signals(server_proc, 1);
123 		sigprocmask(SIG_SETMASK, &oldset, NULL);
124 
125 		if ((cwd == NULL || chdir(cwd) != 0) &&
126 		    ((home = find_home()) == NULL || chdir(home) != 0) &&
127 		    chdir("/") != 0)
128 			fatal("chdir failed");
129 
130 		environ_push(env);
131 		environ_free(env);
132 
133 		if (~flags & JOB_PTY) {
134 			if (dup2(out[1], STDIN_FILENO) == -1)
135 				fatal("dup2 failed");
136 			if (dup2(out[1], STDOUT_FILENO) == -1)
137 				fatal("dup2 failed");
138 			if (out[1] != STDIN_FILENO && out[1] != STDOUT_FILENO)
139 				close(out[1]);
140 			close(out[0]);
141 
142 			nullfd = open(_PATH_DEVNULL, O_RDWR, 0);
143 			if (nullfd == -1)
144 				fatal("open failed");
145 			if (dup2(nullfd, STDERR_FILENO) == -1)
146 				fatal("dup2 failed");
147 			if (nullfd != STDERR_FILENO)
148 				close(nullfd);
149 		}
150 		closefrom(STDERR_FILENO + 1);
151 
152 		if (cmd != NULL) {
153 			execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
154 			fatal("execl failed");
155 		} else {
156 			argvp = cmd_copy_argv(argc, argv);
157 			execvp(argvp[0], argvp);
158 			fatal("execvp failed");
159 		}
160 	}
161 
162 	sigprocmask(SIG_SETMASK, &oldset, NULL);
163 	environ_free(env);
164 
165 	job = xmalloc(sizeof *job);
166 	job->state = JOB_RUNNING;
167 	job->flags = flags;
168 
169 	if (cmd != NULL)
170 		job->cmd = xstrdup(cmd);
171 	else
172 		job->cmd = cmd_stringify_argv(argc, argv);
173 	job->pid = pid;
174 	strlcpy(job->tty, tty, sizeof job->tty);
175 	job->status = 0;
176 
177 	LIST_INSERT_HEAD(&all_jobs, job, entry);
178 
179 	job->updatecb = updatecb;
180 	job->completecb = completecb;
181 	job->freecb = freecb;
182 	job->data = data;
183 
184 	if (~flags & JOB_PTY) {
185 		close(out[1]);
186 		job->fd = out[0];
187 	} else
188 		job->fd = master;
189 	setblocking(job->fd, 0);
190 
191 	job->event = bufferevent_new(job->fd, job_read_callback,
192 	    job_write_callback, job_error_callback, job);
193 	if (job->event == NULL)
194 		fatalx("out of memory");
195 	bufferevent_enable(job->event, EV_READ|EV_WRITE);
196 
197 	log_debug("run job %p: %s, pid %ld", job, job->cmd, (long) job->pid);
198 	return (job);
199 
200 fail:
201 	sigprocmask(SIG_SETMASK, &oldset, NULL);
202 	environ_free(env);
203 	return (NULL);
204 }
205 
206 /* Take job's file descriptor and free the job. */
207 int
208 job_transfer(struct job *job, pid_t *pid, char *tty, size_t ttylen)
209 {
210 	int	fd = job->fd;
211 
212 	log_debug("transfer job %p: %s", job, job->cmd);
213 
214 	if (pid != NULL)
215 		*pid = job->pid;
216 	if (tty != NULL)
217 		strlcpy(tty, job->tty, ttylen);
218 
219 	LIST_REMOVE(job, entry);
220 	free(job->cmd);
221 
222 	if (job->freecb != NULL && job->data != NULL)
223 		job->freecb(job->data);
224 
225 	if (job->event != NULL)
226 		bufferevent_free(job->event);
227 
228 	free(job);
229 	return (fd);
230 }
231 
232 /* Kill and free an individual job. */
233 void
234 job_free(struct job *job)
235 {
236 	log_debug("free job %p: %s", job, job->cmd);
237 
238 	LIST_REMOVE(job, entry);
239 	free(job->cmd);
240 
241 	if (job->freecb != NULL && job->data != NULL)
242 		job->freecb(job->data);
243 
244 	if (job->pid != -1)
245 		kill(job->pid, SIGTERM);
246 	if (job->event != NULL)
247 		bufferevent_free(job->event);
248 	if (job->fd != -1)
249 		close(job->fd);
250 
251 	free(job);
252 }
253 
254 /* Resize job. */
255 void
256 job_resize(struct job *job, u_int sx, u_int sy)
257 {
258 	struct winsize	 ws;
259 
260 	if (job->fd == -1 || (~job->flags & JOB_PTY))
261 		return;
262 
263 	log_debug("resize job %p: %ux%u", job, sx, sy);
264 
265 	memset(&ws, 0, sizeof ws);
266 	ws.ws_col = sx;
267 	ws.ws_row = sy;
268 	if (ioctl(job->fd, TIOCSWINSZ, &ws) == -1)
269 		fatal("ioctl failed");
270 }
271 
272 /* Job buffer read callback. */
273 static void
274 job_read_callback(__unused struct bufferevent *bufev, void *data)
275 {
276 	struct job	*job = data;
277 
278 	if (job->updatecb != NULL)
279 		job->updatecb(job);
280 }
281 
282 /*
283  * Job buffer write callback. Fired when the buffer falls below watermark
284  * (default is empty). If all the data has been written, disable the write
285  * event.
286  */
287 static void
288 job_write_callback(__unused struct bufferevent *bufev, void *data)
289 {
290 	struct job	*job = data;
291 	size_t		 len = EVBUFFER_LENGTH(EVBUFFER_OUTPUT(job->event));
292 
293 	log_debug("job write %p: %s, pid %ld, output left %zu", job, job->cmd,
294 	    (long) job->pid, len);
295 
296 	if (len == 0 && (~job->flags & JOB_KEEPWRITE)) {
297 		shutdown(job->fd, SHUT_WR);
298 		bufferevent_disable(job->event, EV_WRITE);
299 	}
300 }
301 
302 /* Job buffer error callback. */
303 static void
304 job_error_callback(__unused struct bufferevent *bufev, __unused short events,
305     void *data)
306 {
307 	struct job	*job = data;
308 
309 	log_debug("job error %p: %s, pid %ld", job, job->cmd, (long) job->pid);
310 
311 	if (job->state == JOB_DEAD) {
312 		if (job->completecb != NULL)
313 			job->completecb(job);
314 		job_free(job);
315 	} else {
316 		bufferevent_disable(job->event, EV_READ);
317 		job->state = JOB_CLOSED;
318 	}
319 }
320 
321 /* Job died (waitpid() returned its pid). */
322 void
323 job_check_died(pid_t pid, int status)
324 {
325 	struct job	*job;
326 
327 	LIST_FOREACH(job, &all_jobs, entry) {
328 		if (pid == job->pid)
329 			break;
330 	}
331 	if (job == NULL)
332 		return;
333 	if (WIFSTOPPED(status)) {
334 		if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU)
335 			return;
336 		killpg(job->pid, SIGCONT);
337 		return;
338 	}
339 	log_debug("job died %p: %s, pid %ld", job, job->cmd, (long) job->pid);
340 
341 	job->status = status;
342 
343 	if (job->state == JOB_CLOSED) {
344 		if (job->completecb != NULL)
345 			job->completecb(job);
346 		job_free(job);
347 	} else {
348 		job->pid = -1;
349 		job->state = JOB_DEAD;
350 	}
351 }
352 
353 /* Get job status. */
354 int
355 job_get_status(struct job *job)
356 {
357 	return (job->status);
358 }
359 
360 /* Get job data. */
361 void *
362 job_get_data(struct job *job)
363 {
364 	return (job->data);
365 }
366 
367 /* Get job event. */
368 struct bufferevent *
369 job_get_event(struct job *job)
370 {
371 	return (job->event);
372 }
373 
374 /* Kill all jobs. */
375 void
376 job_kill_all(void)
377 {
378 	struct job	*job;
379 
380 	LIST_FOREACH(job, &all_jobs, entry) {
381 		if (job->pid != -1)
382 			kill(job->pid, SIGTERM);
383 	}
384 }
385 
386 /* Are any jobs still running? */
387 int
388 job_still_running(void)
389 {
390 	struct job	*job;
391 
392 	LIST_FOREACH(job, &all_jobs, entry) {
393 		if ((~job->flags & JOB_NOWAIT) && job->state == JOB_RUNNING)
394 			return (1);
395 	}
396 	return (0);
397 }
398 
399 /* Print job summary. */
400 void
401 job_print_summary(struct cmdq_item *item, int blank)
402 {
403 	struct job	*job;
404 	u_int		 n = 0;
405 
406 	LIST_FOREACH(job, &all_jobs, entry) {
407 		if (blank) {
408 			cmdq_print(item, "%s", "");
409 			blank = 0;
410 		}
411 		cmdq_print(item, "Job %u: %s [fd=%d, pid=%ld, status=%d]",
412 		    n, job->cmd, job->fd, (long)job->pid, job->status);
413 		n++;
414 	}
415 }
416