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 <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 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 }