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 /* All jobs list. */
  35 struct joblist  all_jobs = SLIST_HEAD_INITIALIZER(all_jobs);
  36
  37 RB_GENERATE(jobs, job, entry, job_cmp);
  38
  39 void    job_callback(struct bufferevent *, short, void *);
  40
  41 int
  42 job_cmp(struct job *job1, struct job *job2)
  43 {
  44         return (strcmp(job1->cmd, job2->cmd));
  45 }
  46
  47 /* Initialise job tree. */
  48 void
  49 job_tree_init(struct jobs *jobs)
  50 {
  51         RB_INIT(jobs);
  52 }
  53
  54 /* Destroy a job tree. */
  55 void
  56 job_tree_free(struct jobs *jobs)
  57 {
  58         struct job      *job;
  59
  60         while (!RB_EMPTY(jobs)) {
  61                 job = RB_ROOT(jobs);
  62                 RB_REMOVE(jobs, jobs, job);
  63                 job_free(job);
  64         }
  65 }
  66
  67 /* Find a job and return it. */
  68 struct job *
  69 job_get(struct jobs *jobs, const char *cmd)
  70 {
  71         struct job      job;
  72
  73         job.cmd = (char *) cmd;
  74         return (RB_FIND(jobs, jobs, &job));
  75 }
  76
  77 /* Add a job. */
  78 struct job *
  79 job_add(struct jobs *jobs, int flags, struct client *c, const char *cmd,
  80     void (*callbackfn)(struct job *), void (*freefn)(void *), void *data)
  81 {
  82         struct job      *job;
  83
  84         job = xmalloc(sizeof *job);
  85         job->cmd = xstrdup(cmd);
  86         job->pid = -1;
  87         job->status = 0;
  88
  89         job->client = c;
  90
  91         job->fd = -1;
  92         job->event = NULL;
  93
  94         job->callbackfn = callbackfn;
  95         job->freefn = freefn;
  96         job->data = data;
  97
  98         job->flags = flags;
  99
 100         if (jobs != NULL)
 101                 RB_INSERT(jobs, jobs, job);
 102         SLIST_INSERT_HEAD(&all_jobs, job, lentry);
 103
 104         return (job);
 105 }
 106
 107 /* Remove job from tree and free. */
 108 void
 109 job_remove(struct jobs *jobs, struct job *job)
 110 {
 111         if (jobs != NULL)
 112                 RB_REMOVE(jobs, jobs, job);
 113         job_free(job);
 114 }
 115
 116 /* Kill and free an individual job. */
 117 void
 118 job_free(struct job *job)
 119 {
 120         job_kill(job);
 121
 122         SLIST_REMOVE(&all_jobs, job, job, lentry);
 123         xfree(job->cmd);
 124
 125         if (job->freefn != NULL && job->data != NULL)
 126                 job->freefn(job->data);
 127
 128         if (job->fd != -1)
 129                 close(job->fd);
 130         if (job->event != NULL)
 131                 bufferevent_free(job->event);
 132
 133         xfree(job);
 134 }
 135
 136 /* Start a job running, if it isn't already. */
 137 int
 138 job_run(struct job *job)
 139 {
 140         int     nullfd, out[2], mode;
 141
 142         if (job->fd != -1 || job->pid != -1)
 143                 return (0);
 144
 145         if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, out) != 0)
 146                 return (-1);
 147
 148         switch (job->pid = fork()) {
 149         case -1:
 150                 return (-1);
 151         case 0:         /* child */
 152                 clear_signals();
 153
 154                 environ_push(&global_environ);
 155
 156                 if (dup2(out[1], STDOUT_FILENO) == -1)
 157                         fatal("dup2 failed");
 158                 if (out[1] != STDOUT_FILENO)
 159                         close(out[1]);
 160                 close(out[0]);
 161
 162                 nullfd = open(_PATH_DEVNULL, O_RDWR, 0);
 163                 if (nullfd < 0)
 164                         fatal("open failed");
 165                 if (dup2(nullfd, STDIN_FILENO) == -1)
 166                         fatal("dup2 failed");
 167                 if (dup2(nullfd, STDERR_FILENO) == -1)
 168                         fatal("dup2 failed");
 169                 if (nullfd != STDIN_FILENO && nullfd != STDERR_FILENO)
 170                         close(nullfd);
 171
 172                 execl(_PATH_BSHELL, "sh", "-c", job->cmd, (char *) NULL);
 173                 fatal("execl failed");
 174         default:        /* parent */
 175                 close(out[1]);
 176
 177                 job->fd = out[0];
 178                 if ((mode = fcntl(job->fd, F_GETFL)) == -1)
 179                         fatal("fcntl failed");
 180                 if (fcntl(job->fd, F_SETFL, mode|O_NONBLOCK) == -1)
 181                         fatal("fcntl failed");
 182                 if (fcntl(job->fd, F_SETFD, FD_CLOEXEC) == -1)
 183                         fatal("fcntl failed");
 184
 185                 if (job->event != NULL)
 186                         bufferevent_free(job->event);
 187                 job->event =
 188                     bufferevent_new(job->fd, NULL, NULL, job_callback, job);
 189                 bufferevent_enable(job->event, EV_READ);
 190
 191                 return (0);
 192         }
 193 }
 194
 195 /* Job buffer error callback. */
 196 /* ARGSUSED */
 197 void
 198 job_callback(unused struct bufferevent *bufev, unused short events, void *data)
 199 {
 200         struct job      *job = data;
 201
 202         bufferevent_disable(job->event, EV_READ);
 203         close(job->fd);
 204         job->fd = -1;
 205
 206         if (job->pid == -1) {
 207                 if (job->callbackfn != NULL)
 208                         job->callbackfn(job);
 209                 if ((!job->flags & JOB_PERSIST))
 210                         job_free(job);
 211         }
 212 }
 213
 214 /* Job died (waitpid() returned its pid). */
 215 void
 216 job_died(struct job *job, int status)
 217 {
 218         job->status = status;
 219         job->pid = -1;
 220
 221         if (job->fd == -1) {
 222                 if (job->callbackfn != NULL)
 223                         job->callbackfn(job);
 224                 if ((!job->flags & JOB_PERSIST))
 225                         job_free(job);
 226         }
 227 }
 228
 229 /* Kill a job. */
 230 void
 231 job_kill(struct job *job)
 232 {
 233         if (job->pid == -1)
 234                 return;
 235         kill(job->pid, SIGTERM);
 236         job->pid = -1;
 237 }