xref: /openbsd-src/usr.bin/tmux/job.c (revision 097a140d792de8b2bbe59ad827d39eabf9b4280a)
1 /* $OpenBSD: job.c,v 1.60 2021/03/02 10:56:45 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 	int			 status;
56 
57 	int			 fd;
58 	struct bufferevent	*event;
59 
60 	job_update_cb		 updatecb;
61 	job_complete_cb		 completecb;
62 	job_free_cb		 freecb;
63 	void			*data;
64 
65 	LIST_ENTRY(job)		 entry;
66 };
67 
68 /* All jobs list. */
69 static LIST_HEAD(joblist, job) all_jobs = LIST_HEAD_INITIALIZER(all_jobs);
70 
71 /* Start a job running. */
72 struct job *
73 job_run(const char *cmd, int argc, char **argv, struct session *s,
74     const char *cwd, job_update_cb updatecb, job_complete_cb completecb,
75     job_free_cb freecb, void *data, int flags, int sx, int sy)
76 {
77 	struct job	 *job;
78 	struct environ	 *env;
79 	pid_t		  pid;
80 	int		  nullfd, out[2], master;
81 	const char	 *home;
82 	sigset_t	  set, oldset;
83 	struct winsize	  ws;
84 	char		**argvp;
85 
86 	/*
87 	 * Do not set TERM during .tmux.conf, it is nice to be able to use
88 	 * if-shell to decide on default-terminal based on outside TERM.
89 	 */
90 	env = environ_for_session(s, !cfg_finished);
91 
92 	sigfillset(&set);
93 	sigprocmask(SIG_BLOCK, &set, &oldset);
94 
95 	if (flags & JOB_PTY) {
96 		memset(&ws, 0, sizeof ws);
97 		ws.ws_col = sx;
98 		ws.ws_row = sy;
99 		pid = fdforkpty(ptm_fd, &master, NULL, NULL, &ws);
100 	} else {
101 		if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, out) != 0)
102 			goto fail;
103 		pid = fork();
104 	}
105 	if (cmd == NULL) {
106 		cmd_log_argv(argc, argv, "%s:", __func__);
107 		log_debug("%s: cwd=%s", __func__, cwd == NULL ? "" : cwd);
108 	} else {
109 		log_debug("%s: cmd=%s, cwd=%s", __func__, cmd,
110 		    cwd == NULL ? "" : cwd);
111 	}
112 
113 	switch (pid) {
114 	case -1:
115 		if (~flags & JOB_PTY) {
116 			close(out[0]);
117 			close(out[1]);
118 		}
119 		goto fail;
120 	case 0:
121 		proc_clear_signals(server_proc, 1);
122 		sigprocmask(SIG_SETMASK, &oldset, NULL);
123 
124 		if ((cwd == NULL || chdir(cwd) != 0) &&
125 		    ((home = find_home()) == NULL || chdir(home) != 0) &&
126 		    chdir("/") != 0)
127 			fatal("chdir failed");
128 
129 		environ_push(env);
130 		environ_free(env);
131 
132 		if (~flags & JOB_PTY) {
133 			if (dup2(out[1], STDIN_FILENO) == -1)
134 				fatal("dup2 failed");
135 			if (dup2(out[1], STDOUT_FILENO) == -1)
136 				fatal("dup2 failed");
137 			if (out[1] != STDIN_FILENO && out[1] != STDOUT_FILENO)
138 				close(out[1]);
139 			close(out[0]);
140 
141 			nullfd = open(_PATH_DEVNULL, O_RDWR, 0);
142 			if (nullfd == -1)
143 				fatal("open failed");
144 			if (dup2(nullfd, STDERR_FILENO) == -1)
145 				fatal("dup2 failed");
146 			if (nullfd != STDERR_FILENO)
147 				close(nullfd);
148 		}
149 		closefrom(STDERR_FILENO + 1);
150 
151 		if (cmd != NULL) {
152 			execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
153 			fatal("execl failed");
154 		} else {
155 			argvp = cmd_copy_argv(argc, argv);
156 			execvp(argvp[0], argvp);
157 			fatal("execvp failed");
158 		}
159 	}
160 
161 	sigprocmask(SIG_SETMASK, &oldset, NULL);
162 	environ_free(env);
163 
164 	job = xmalloc(sizeof *job);
165 	job->state = JOB_RUNNING;
166 	job->flags = flags;
167 
168 	if (cmd != NULL)
169 		job->cmd = xstrdup(cmd);
170 	else
171 		job->cmd = cmd_stringify_argv(argc, argv);
172 	job->pid = pid;
173 	job->status = 0;
174 
175 	LIST_INSERT_HEAD(&all_jobs, job, entry);
176 
177 	job->updatecb = updatecb;
178 	job->completecb = completecb;
179 	job->freecb = freecb;
180 	job->data = data;
181 
182 	if (~flags & JOB_PTY) {
183 		close(out[1]);
184 		job->fd = out[0];
185 	} else
186 		job->fd = master;
187 	setblocking(job->fd, 0);
188 
189 	job->event = bufferevent_new(job->fd, job_read_callback,
190 	    job_write_callback, job_error_callback, job);
191 	if (job->event == NULL)
192 		fatalx("out of memory");
193 	bufferevent_enable(job->event, EV_READ|EV_WRITE);
194 
195 	log_debug("run job %p: %s, pid %ld", job, job->cmd, (long) job->pid);
196 	return (job);
197 
198 fail:
199 	sigprocmask(SIG_SETMASK, &oldset, NULL);
200 	environ_free(env);
201 	return (NULL);
202 }
203 
204 /* Kill and free an individual job. */
205 void
206 job_free(struct job *job)
207 {
208 	log_debug("free job %p: %s", job, job->cmd);
209 
210 	LIST_REMOVE(job, entry);
211 	free(job->cmd);
212 
213 	if (job->freecb != NULL && job->data != NULL)
214 		job->freecb(job->data);
215 
216 	if (job->pid != -1)
217 		kill(job->pid, SIGTERM);
218 	if (job->event != NULL)
219 		bufferevent_free(job->event);
220 	if (job->fd != -1)
221 		close(job->fd);
222 
223 	free(job);
224 }
225 
226 /* Resize job. */
227 void
228 job_resize(struct job *job, u_int sx, u_int sy)
229 {
230 	struct winsize	 ws;
231 
232 	if (job->fd == -1 || (~job->flags & JOB_PTY))
233 		return;
234 
235 	log_debug("resize job %p: %ux%u", job, sx, sy);
236 
237 	memset(&ws, 0, sizeof ws);
238 	ws.ws_col = sx;
239 	ws.ws_row = sy;
240 	if (ioctl(job->fd, TIOCSWINSZ, &ws) == -1)
241 		fatal("ioctl failed");
242 }
243 
244 /* Job buffer read callback. */
245 static void
246 job_read_callback(__unused struct bufferevent *bufev, void *data)
247 {
248 	struct job	*job = data;
249 
250 	if (job->updatecb != NULL)
251 		job->updatecb(job);
252 }
253 
254 /*
255  * Job buffer write callback. Fired when the buffer falls below watermark
256  * (default is empty). If all the data has been written, disable the write
257  * event.
258  */
259 static void
260 job_write_callback(__unused struct bufferevent *bufev, void *data)
261 {
262 	struct job	*job = data;
263 	size_t		 len = EVBUFFER_LENGTH(EVBUFFER_OUTPUT(job->event));
264 
265 	log_debug("job write %p: %s, pid %ld, output left %zu", job, job->cmd,
266 	    (long) job->pid, len);
267 
268 	if (len == 0 && (~job->flags & JOB_KEEPWRITE)) {
269 		shutdown(job->fd, SHUT_WR);
270 		bufferevent_disable(job->event, EV_WRITE);
271 	}
272 }
273 
274 /* Job buffer error callback. */
275 static void
276 job_error_callback(__unused struct bufferevent *bufev, __unused short events,
277     void *data)
278 {
279 	struct job	*job = data;
280 
281 	log_debug("job error %p: %s, pid %ld", job, job->cmd, (long) job->pid);
282 
283 	if (job->state == JOB_DEAD) {
284 		if (job->completecb != NULL)
285 			job->completecb(job);
286 		job_free(job);
287 	} else {
288 		bufferevent_disable(job->event, EV_READ);
289 		job->state = JOB_CLOSED;
290 	}
291 }
292 
293 /* Job died (waitpid() returned its pid). */
294 void
295 job_check_died(pid_t pid, int status)
296 {
297 	struct job	*job;
298 
299 	LIST_FOREACH(job, &all_jobs, entry) {
300 		if (pid == job->pid)
301 			break;
302 	}
303 	if (job == NULL)
304 		return;
305 	if (WIFSTOPPED(status)) {
306 		if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU)
307 			return;
308 		killpg(job->pid, SIGCONT);
309 		return;
310 	}
311 	log_debug("job died %p: %s, pid %ld", job, job->cmd, (long) job->pid);
312 
313 	job->status = status;
314 
315 	if (job->state == JOB_CLOSED) {
316 		if (job->completecb != NULL)
317 			job->completecb(job);
318 		job_free(job);
319 	} else {
320 		job->pid = -1;
321 		job->state = JOB_DEAD;
322 	}
323 }
324 
325 /* Get job status. */
326 int
327 job_get_status(struct job *job)
328 {
329 	return (job->status);
330 }
331 
332 /* Get job data. */
333 void *
334 job_get_data(struct job *job)
335 {
336 	return (job->data);
337 }
338 
339 /* Get job event. */
340 struct bufferevent *
341 job_get_event(struct job *job)
342 {
343 	return (job->event);
344 }
345 
346 /* Kill all jobs. */
347 void
348 job_kill_all(void)
349 {
350 	struct job	*job;
351 
352 	LIST_FOREACH(job, &all_jobs, entry) {
353 		if (job->pid != -1)
354 			kill(job->pid, SIGTERM);
355 	}
356 }
357 
358 /* Are any jobs still running? */
359 int
360 job_still_running(void)
361 {
362 	struct job	*job;
363 
364 	LIST_FOREACH(job, &all_jobs, entry) {
365 		if ((~job->flags & JOB_NOWAIT) && job->state == JOB_RUNNING)
366 			return (1);
367 	}
368 	return (0);
369 }
370 
371 /* Print job summary. */
372 void
373 job_print_summary(struct cmdq_item *item, int blank)
374 {
375 	struct job	*job;
376 	u_int		 n = 0;
377 
378 	LIST_FOREACH(job, &all_jobs, entry) {
379 		if (blank) {
380 			cmdq_print(item, "%s", "");
381 			blank = 0;
382 		}
383 		cmdq_print(item, "Job %u: %s [fd=%d, pid=%ld, status=%d]",
384 		    n, job->cmd, job->fd, (long)job->pid, job->status);
385 		n++;
386 	}
387 }
388