1 /* Id */
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 <stdlib.h>
24 #include <string.h>
25 #include <unistd.h>
26
27 #include "tmux.h"
28
29 /*
30 * Job scheduling. Run queued commands in the background and record their
31 * output.
32 */
33
34 void job_callback(struct bufferevent *, short, void *);
35 void job_write_callback(struct bufferevent *, 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 *
job_run(const char * cmd,struct session * s,void (* callbackfn)(struct job *),void (* freefn)(void *),void * data)42 job_run(const char *cmd, struct session *s,
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 if (s != NULL)
56 environ_copy(&s->environ, &env);
57 server_fill_environ(s, &env);
58
59 switch (pid = fork()) {
60 case -1:
61 environ_free(&env);
62 return (NULL);
63 case 0: /* child */
64 clear_signals(1);
65
66 environ_push(&env);
67 environ_free(&env);
68
69 if (dup2(out[1], STDIN_FILENO) == -1)
70 fatal("dup2 failed");
71 if (dup2(out[1], STDOUT_FILENO) == -1)
72 fatal("dup2 failed");
73 if (out[1] != STDIN_FILENO && out[1] != STDOUT_FILENO)
74 close(out[1]);
75 close(out[0]);
76
77 nullfd = open(_PATH_DEVNULL, O_RDWR, 0);
78 if (nullfd < 0)
79 fatal("open failed");
80 if (dup2(nullfd, STDERR_FILENO) == -1)
81 fatal("dup2 failed");
82 if (nullfd != STDERR_FILENO)
83 close(nullfd);
84
85 closefrom(STDERR_FILENO + 1);
86
87 execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL);
88 fatal("execl failed");
89 }
90
91 /* parent */
92 environ_free(&env);
93 close(out[1]);
94
95 job = xmalloc(sizeof *job);
96 job->cmd = xstrdup(cmd);
97 job->pid = pid;
98 job->status = 0;
99
100 LIST_INSERT_HEAD(&all_jobs, job, lentry);
101
102 job->callbackfn = callbackfn;
103 job->freefn = freefn;
104 job->data = data;
105
106 job->fd = out[0];
107 setblocking(job->fd, 0);
108
109 job->event = bufferevent_new(job->fd, NULL, job_write_callback,
110 job_callback, job);
111 bufferevent_enable(job->event, EV_READ|EV_WRITE);
112
113 log_debug("run job %p: %s, pid %ld", job, job->cmd, (long) job->pid);
114 return (job);
115 }
116
117 /* Kill and free an individual job. */
118 void
job_free(struct job * job)119 job_free(struct job *job)
120 {
121 log_debug("free job %p: %s", job, job->cmd);
122
123 LIST_REMOVE(job, lentry);
124 free(job->cmd);
125
126 if (job->freefn != NULL && job->data != NULL)
127 job->freefn(job->data);
128
129 if (job->pid != -1)
130 kill(job->pid, SIGTERM);
131 if (job->event != NULL)
132 bufferevent_free(job->event);
133 if (job->fd != -1)
134 close(job->fd);
135
136 free(job);
137 }
138
139 /* Called when output buffer falls below low watermark (default is 0). */
140 void
job_write_callback(unused struct bufferevent * bufev,void * data)141 job_write_callback(unused struct bufferevent *bufev, void *data)
142 {
143 struct job *job = data;
144 size_t len = EVBUFFER_LENGTH(EVBUFFER_OUTPUT(job->event));
145
146 log_debug("job write %p: %s, pid %ld, output left %zu", job, job->cmd,
147 (long) job->pid, len);
148
149 if (len == 0) {
150 shutdown(job->fd, SHUT_WR);
151 bufferevent_disable(job->event, EV_WRITE);
152 }
153 }
154
155 /* Job buffer error callback. */
156 void
job_callback(unused struct bufferevent * bufev,unused short events,void * data)157 job_callback(unused struct bufferevent *bufev, unused short events, void *data)
158 {
159 struct job *job = data;
160
161 log_debug("job error %p: %s, pid %ld", job, job->cmd, (long) job->pid);
162
163 if (job->pid == -1) {
164 if (job->callbackfn != NULL)
165 job->callbackfn(job);
166 job_free(job);
167 } else {
168 bufferevent_disable(job->event, EV_READ);
169 close(job->fd);
170 job->fd = -1;
171 }
172 }
173
174 /* Job died (waitpid() returned its pid). */
175 void
job_died(struct job * job,int status)176 job_died(struct job *job, int status)
177 {
178 log_debug("job died %p: %s, pid %ld", job, job->cmd, (long) job->pid);
179
180 job->status = status;
181
182 if (job->fd == -1) {
183 if (job->callbackfn != NULL)
184 job->callbackfn(job);
185 job_free(job);
186 } else
187 job->pid = -1;
188 }
189