job.c

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