xref: /openbsd-src/usr.bin/tmux/job.c (revision 4c1e55dc91edd6e69ccc60ce855900fbc12cf34f)
1 /* $OpenBSD: job.c,v 1.27 2012/07/10 11:53:01 nicm Exp $ */
2 
3 /*
4  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
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/socket.h>
21 
22 #include <fcntl.h>
23 #include <paths.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 
28 #include "tmux.h"
29 
30 /*
31  * Job scheduling. Run queued commands in the background and record their
32  * output.
33  */
34 
35 void	job_callback(struct bufferevent *, short, void *);
36 
37 /* All jobs list. */
38 struct joblist	all_jobs = LIST_HEAD_INITIALIZER(all_jobs);
39 
40 /* Start a job running, if it isn't already. */
41 struct job *
42 job_run(const char *cmd,
43     void (*callbackfn)(struct job *), void (*freefn)(void *), void *data)
44 {
45 	struct job	*job;
46 	struct environ	 env;
47 	pid_t		 pid;
48 	int		 nullfd, out[2];
49 
50 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, out) != 0)
51 		return (NULL);
52 
53 	environ_init(&env);
54 	environ_copy(&global_environ, &env);
55 	server_fill_environ(NULL, &env);
56 
57 	switch (pid = fork()) {
58 	case -1:
59 		environ_free(&env);
60 		return (NULL);
61 	case 0:		/* child */
62 		clear_signals(1);
63 
64 		environ_push(&env);
65 		environ_free(&env);
66 
67 		if (dup2(out[1], STDOUT_FILENO) == -1)
68 			fatal("dup2 failed");
69 		if (out[1] != STDOUT_FILENO)
70 			close(out[1]);
71 		close(out[0]);
72 
73 		nullfd = open(_PATH_DEVNULL, O_RDWR, 0);
74 		if (nullfd < 0)
75 			fatal("open failed");
76 		if (dup2(nullfd, STDIN_FILENO) == -1)
77 			fatal("dup2 failed");
78 		if (dup2(nullfd, STDERR_FILENO) == -1)
79 			fatal("dup2 failed");
80 		if (nullfd != STDIN_FILENO && nullfd != STDERR_FILENO)
81 			close(nullfd);
82 
83 		closefrom(STDERR_FILENO + 1);
84 
85 		execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
86 		fatal("execl failed");
87 	}
88 
89 	/* parent */
90 	environ_free(&env);
91 	close(out[1]);
92 
93 	job = xmalloc(sizeof *job);
94 	job->cmd = xstrdup(cmd);
95 	job->pid = pid;
96 	job->status = 0;
97 
98 	LIST_INSERT_HEAD(&all_jobs, job, lentry);
99 
100 	job->callbackfn = callbackfn;
101 	job->freefn = freefn;
102 	job->data = data;
103 
104 	job->fd = out[0];
105 	setblocking(job->fd, 0);
106 
107 	job->event = bufferevent_new(job->fd, NULL, NULL, job_callback, job);
108 	bufferevent_enable(job->event, EV_READ);
109 
110 	log_debug("run job %p: %s, pid %ld", job, job->cmd, (long) job->pid);
111 	return (job);
112 }
113 
114 /* Kill and free an individual job. */
115 void
116 job_free(struct job *job)
117 {
118 	log_debug("free job %p: %s", job, job->cmd);
119 
120 	LIST_REMOVE(job, lentry);
121 	free(job->cmd);
122 
123 	if (job->freefn != NULL && job->data != NULL)
124 		job->freefn(job->data);
125 
126 	if (job->pid != -1)
127 		kill(job->pid, SIGTERM);
128 	if (job->event != NULL)
129 		bufferevent_free(job->event);
130 	if (job->fd != -1)
131 		close(job->fd);
132 
133 	free(job);
134 }
135 
136 /* Job buffer error callback. */
137 /* ARGSUSED */
138 void
139 job_callback(unused struct bufferevent *bufev, unused short events, void *data)
140 {
141 	struct job	*job = data;
142 
143 	log_debug("job error %p: %s, pid %ld", job, job->cmd, (long) job->pid);
144 
145 	if (job->pid == -1) {
146 		if (job->callbackfn != NULL)
147 			job->callbackfn(job);
148 		job_free(job);
149 	} else {
150 		bufferevent_disable(job->event, EV_READ);
151 		close(job->fd);
152 		job->fd = -1;
153 	}
154 }
155 
156 /* Job died (waitpid() returned its pid). */
157 void
158 job_died(struct job *job, int status)
159 {
160 	log_debug("job died %p: %s, pid %ld", job, job->cmd, (long) job->pid);
161 
162 	job->status = status;
163 
164 	if (job->fd == -1) {
165 		if (job->callbackfn != NULL)
166 			job->callbackfn(job);
167 		job_free(job);
168 	} else
169 		job->pid = -1;
170 }
171