xref: /openbsd/usr.bin/tmux/job.c (revision 668a68ad)
1 /* $OpenBSD: job.c,v 1.69 2024/09/30 07:54:51 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 *
job_run(const char * cmd,int argc,char ** argv,struct environ * e,struct session * s,const char * cwd,job_update_cb updatecb,job_complete_cb completecb,job_free_cb freecb,void * data,int flags,int sx,int sy)74 job_run(const char *cmd, int argc, char **argv, struct environ *e,
75     struct session *s, const char *cwd, job_update_cb updatecb,
76     job_complete_cb completecb, job_free_cb freecb, void *data, int flags,
77     int sx, int sy)
78 {
79 	struct job	 *job;
80 	struct environ	 *env;
81 	pid_t		  pid;
82 	int		  nullfd, out[2], master;
83 	const char	 *home, *shell;
84 	sigset_t	  set, oldset;
85 	struct winsize	  ws;
86 	char		**argvp, tty[TTY_NAME_MAX], *argv0;
87 	struct options	 *oo;
88 
89 	/*
90 	 * Do not set TERM during .tmux.conf (second argument here), it is nice
91 	 * to be able to use if-shell to decide on default-terminal based on
92 	 * outside TERM.
93 	 */
94 	env = environ_for_session(s, !cfg_finished);
95 	if (e != NULL)
96 		environ_copy(e, env);
97 
98 	if (~flags & JOB_DEFAULTSHELL)
99 		shell = _PATH_BSHELL;
100 	else {
101 		if (s != NULL)
102 			oo = s->options;
103 		else
104 			oo = global_s_options;
105 		shell = options_get_string(oo, "default-shell");
106 		if (!checkshell(shell))
107 			shell = _PATH_BSHELL;
108 	}
109 	argv0 = shell_argv0(shell, 0);
110 
111 	sigfillset(&set);
112 	sigprocmask(SIG_BLOCK, &set, &oldset);
113 
114 	if (flags & JOB_PTY) {
115 		memset(&ws, 0, sizeof ws);
116 		ws.ws_col = sx;
117 		ws.ws_row = sy;
118 		pid = fdforkpty(ptm_fd, &master, tty, NULL, &ws);
119 	} else {
120 		if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, out) != 0)
121 			goto fail;
122 		pid = fork();
123 	}
124 	if (cmd == NULL) {
125 		cmd_log_argv(argc, argv, "%s:", __func__);
126 		log_debug("%s: cwd=%s, shell=%s", __func__,
127 		    cwd == NULL ? "" : cwd, shell);
128 	} else {
129 		log_debug("%s: cmd=%s, cwd=%s, shell=%s", __func__, cmd,
130 		    cwd == NULL ? "" : cwd, shell);
131 	}
132 
133 	switch (pid) {
134 	case -1:
135 		if (~flags & JOB_PTY) {
136 			close(out[0]);
137 			close(out[1]);
138 		}
139 		goto fail;
140 	case 0:
141 		proc_clear_signals(server_proc, 1);
142 		sigprocmask(SIG_SETMASK, &oldset, NULL);
143 
144 		if ((cwd == NULL || chdir(cwd) != 0) &&
145 		    ((home = find_home()) == NULL || chdir(home) != 0) &&
146 		    chdir("/") != 0)
147 			fatal("chdir failed");
148 
149 		environ_push(env);
150 		environ_free(env);
151 
152 		if (~flags & JOB_PTY) {
153 			if (dup2(out[1], STDIN_FILENO) == -1)
154 				fatal("dup2 failed");
155 			if (dup2(out[1], STDOUT_FILENO) == -1)
156 				fatal("dup2 failed");
157 			if (out[1] != STDIN_FILENO && out[1] != STDOUT_FILENO)
158 				close(out[1]);
159 			close(out[0]);
160 
161 			nullfd = open(_PATH_DEVNULL, O_RDWR);
162 			if (nullfd == -1)
163 				fatal("open failed");
164 			if (dup2(nullfd, STDERR_FILENO) == -1)
165 				fatal("dup2 failed");
166 			if (nullfd != STDERR_FILENO)
167 				close(nullfd);
168 		}
169 		closefrom(STDERR_FILENO + 1);
170 
171 		if (cmd != NULL) {
172 			setenv("SHELL", shell, 1);
173 			execl(shell, argv0, "-c", cmd, (char *)NULL);
174 			fatal("execl failed");
175 		} else {
176 			argvp = cmd_copy_argv(argc, argv);
177 			execvp(argvp[0], argvp);
178 			fatal("execvp failed");
179 		}
180 	}
181 
182 	sigprocmask(SIG_SETMASK, &oldset, NULL);
183 	environ_free(env);
184 	free(argv0);
185 
186 	job = xmalloc(sizeof *job);
187 	job->state = JOB_RUNNING;
188 	job->flags = flags;
189 
190 	if (cmd != NULL)
191 		job->cmd = xstrdup(cmd);
192 	else
193 		job->cmd = cmd_stringify_argv(argc, argv);
194 	job->pid = pid;
195 	strlcpy(job->tty, tty, sizeof job->tty);
196 	job->status = 0;
197 
198 	LIST_INSERT_HEAD(&all_jobs, job, entry);
199 
200 	job->updatecb = updatecb;
201 	job->completecb = completecb;
202 	job->freecb = freecb;
203 	job->data = data;
204 
205 	if (~flags & JOB_PTY) {
206 		close(out[1]);
207 		job->fd = out[0];
208 	} else
209 		job->fd = master;
210 	setblocking(job->fd, 0);
211 
212 	job->event = bufferevent_new(job->fd, job_read_callback,
213 	    job_write_callback, job_error_callback, job);
214 	if (job->event == NULL)
215 		fatalx("out of memory");
216 	bufferevent_enable(job->event, EV_READ|EV_WRITE);
217 
218 	log_debug("run job %p: %s, pid %ld", job, job->cmd, (long)job->pid);
219 	return (job);
220 
221 fail:
222 	sigprocmask(SIG_SETMASK, &oldset, NULL);
223 	environ_free(env);
224 	free(argv0);
225 	return (NULL);
226 }
227 
228 /* Take job's file descriptor and free the job. */
229 int
job_transfer(struct job * job,pid_t * pid,char * tty,size_t ttylen)230 job_transfer(struct job *job, pid_t *pid, char *tty, size_t ttylen)
231 {
232 	int	fd = job->fd;
233 
234 	log_debug("transfer job %p: %s", job, job->cmd);
235 
236 	if (pid != NULL)
237 		*pid = job->pid;
238 	if (tty != NULL)
239 		strlcpy(tty, job->tty, ttylen);
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->event != NULL)
248 		bufferevent_free(job->event);
249 
250 	free(job);
251 	return (fd);
252 }
253 
254 /* Kill and free an individual job. */
255 void
job_free(struct job * job)256 job_free(struct job *job)
257 {
258 	log_debug("free job %p: %s", job, job->cmd);
259 
260 	LIST_REMOVE(job, entry);
261 	free(job->cmd);
262 
263 	if (job->freecb != NULL && job->data != NULL)
264 		job->freecb(job->data);
265 
266 	if (job->pid != -1)
267 		kill(job->pid, SIGTERM);
268 	if (job->event != NULL)
269 		bufferevent_free(job->event);
270 	if (job->fd != -1)
271 		close(job->fd);
272 
273 	free(job);
274 }
275 
276 /* Resize job. */
277 void
job_resize(struct job * job,u_int sx,u_int sy)278 job_resize(struct job *job, u_int sx, u_int sy)
279 {
280 	struct winsize	 ws;
281 
282 	if (job->fd == -1 || (~job->flags & JOB_PTY))
283 		return;
284 
285 	log_debug("resize job %p: %ux%u", job, sx, sy);
286 
287 	memset(&ws, 0, sizeof ws);
288 	ws.ws_col = sx;
289 	ws.ws_row = sy;
290 	if (ioctl(job->fd, TIOCSWINSZ, &ws) == -1)
291 		fatal("ioctl failed");
292 }
293 
294 /* Job buffer read callback. */
295 static void
job_read_callback(__unused struct bufferevent * bufev,void * data)296 job_read_callback(__unused struct bufferevent *bufev, void *data)
297 {
298 	struct job	*job = data;
299 
300 	if (job->updatecb != NULL)
301 		job->updatecb(job);
302 }
303 
304 /*
305  * Job buffer write callback. Fired when the buffer falls below watermark
306  * (default is empty). If all the data has been written, disable the write
307  * event.
308  */
309 static void
job_write_callback(__unused struct bufferevent * bufev,void * data)310 job_write_callback(__unused struct bufferevent *bufev, void *data)
311 {
312 	struct job	*job = data;
313 	size_t		 len = EVBUFFER_LENGTH(EVBUFFER_OUTPUT(job->event));
314 
315 	log_debug("job write %p: %s, pid %ld, output left %zu", job, job->cmd,
316 	    (long) job->pid, len);
317 
318 	if (len == 0 && (~job->flags & JOB_KEEPWRITE)) {
319 		shutdown(job->fd, SHUT_WR);
320 		bufferevent_disable(job->event, EV_WRITE);
321 	}
322 }
323 
324 /* Job buffer error callback. */
325 static void
job_error_callback(__unused struct bufferevent * bufev,__unused short events,void * data)326 job_error_callback(__unused struct bufferevent *bufev, __unused short events,
327     void *data)
328 {
329 	struct job	*job = data;
330 
331 	log_debug("job error %p: %s, pid %ld", job, job->cmd, (long) job->pid);
332 
333 	if (job->state == JOB_DEAD) {
334 		if (job->completecb != NULL)
335 			job->completecb(job);
336 		job_free(job);
337 	} else {
338 		bufferevent_disable(job->event, EV_READ);
339 		job->state = JOB_CLOSED;
340 	}
341 }
342 
343 /* Job died (waitpid() returned its pid). */
344 void
job_check_died(pid_t pid,int status)345 job_check_died(pid_t pid, int status)
346 {
347 	struct job	*job;
348 
349 	LIST_FOREACH(job, &all_jobs, entry) {
350 		if (pid == job->pid)
351 			break;
352 	}
353 	if (job == NULL)
354 		return;
355 	if (WIFSTOPPED(status)) {
356 		if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU)
357 			return;
358 		killpg(job->pid, SIGCONT);
359 		return;
360 	}
361 	log_debug("job died %p: %s, pid %ld", job, job->cmd, (long) job->pid);
362 
363 	job->status = status;
364 
365 	if (job->state == JOB_CLOSED) {
366 		if (job->completecb != NULL)
367 			job->completecb(job);
368 		job_free(job);
369 	} else {
370 		job->pid = -1;
371 		job->state = JOB_DEAD;
372 	}
373 }
374 
375 /* Get job status. */
376 int
job_get_status(struct job * job)377 job_get_status(struct job *job)
378 {
379 	return (job->status);
380 }
381 
382 /* Get job data. */
383 void *
job_get_data(struct job * job)384 job_get_data(struct job *job)
385 {
386 	return (job->data);
387 }
388 
389 /* Get job event. */
390 struct bufferevent *
job_get_event(struct job * job)391 job_get_event(struct job *job)
392 {
393 	return (job->event);
394 }
395 
396 /* Kill all jobs. */
397 void
job_kill_all(void)398 job_kill_all(void)
399 {
400 	struct job	*job;
401 
402 	LIST_FOREACH(job, &all_jobs, entry) {
403 		if (job->pid != -1)
404 			kill(job->pid, SIGTERM);
405 	}
406 }
407 
408 /* Are any jobs still running? */
409 int
job_still_running(void)410 job_still_running(void)
411 {
412 	struct job	*job;
413 
414 	LIST_FOREACH(job, &all_jobs, entry) {
415 		if ((~job->flags & JOB_NOWAIT) && job->state == JOB_RUNNING)
416 			return (1);
417 	}
418 	return (0);
419 }
420 
421 /* Print job summary. */
422 void
job_print_summary(struct cmdq_item * item,int blank)423 job_print_summary(struct cmdq_item *item, int blank)
424 {
425 	struct job	*job;
426 	u_int		 n = 0;
427 
428 	LIST_FOREACH(job, &all_jobs, entry) {
429 		if (blank) {
430 			cmdq_print(item, "%s", "");
431 			blank = 0;
432 		}
433 		cmdq_print(item, "Job %u: %s [fd=%d, pid=%ld, status=%d]",
434 		    n, job->cmd, job->fd, (long)job->pid, job->status);
435 		n++;
436 	}
437 }
438