1 /* $OpenBSD: job.c,v 1.33 2014/04/14 22:27:30 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 void job_write_callback(struct bufferevent *, void *); 37 38 /* All jobs list. */ 39 struct joblist all_jobs = LIST_HEAD_INITIALIZER(all_jobs); 40 41 /* Start a job running, if it isn't already. */ 42 struct job * 43 job_run(const char *cmd, struct session *s, 44 void (*callbackfn)(struct job *), void (*freefn)(void *), void *data) 45 { 46 struct job *job; 47 struct environ env; 48 pid_t pid; 49 int nullfd, out[2]; 50 51 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, out) != 0) 52 return (NULL); 53 54 environ_init(&env); 55 environ_copy(&global_environ, &env); 56 if (s != NULL) 57 environ_copy(&s->environ, &env); 58 server_fill_environ(s, &env); 59 60 switch (pid = fork()) { 61 case -1: 62 environ_free(&env); 63 close(out[0]); 64 close(out[1]); 65 return (NULL); 66 case 0: /* child */ 67 clear_signals(1); 68 69 environ_push(&env); 70 environ_free(&env); 71 72 if (dup2(out[1], STDIN_FILENO) == -1) 73 fatal("dup2 failed"); 74 if (dup2(out[1], STDOUT_FILENO) == -1) 75 fatal("dup2 failed"); 76 if (out[1] != STDIN_FILENO && out[1] != STDOUT_FILENO) 77 close(out[1]); 78 close(out[0]); 79 80 nullfd = open(_PATH_DEVNULL, O_RDWR, 0); 81 if (nullfd < 0) 82 fatal("open failed"); 83 if (dup2(nullfd, STDERR_FILENO) == -1) 84 fatal("dup2 failed"); 85 if (nullfd != STDERR_FILENO) 86 close(nullfd); 87 88 closefrom(STDERR_FILENO + 1); 89 90 execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL); 91 fatal("execl failed"); 92 } 93 94 /* parent */ 95 environ_free(&env); 96 close(out[1]); 97 98 job = xmalloc(sizeof *job); 99 job->cmd = xstrdup(cmd); 100 job->pid = pid; 101 job->status = 0; 102 103 LIST_INSERT_HEAD(&all_jobs, job, lentry); 104 105 job->callbackfn = callbackfn; 106 job->freefn = freefn; 107 job->data = data; 108 109 job->fd = out[0]; 110 setblocking(job->fd, 0); 111 112 job->event = bufferevent_new(job->fd, NULL, job_write_callback, 113 job_callback, job); 114 bufferevent_enable(job->event, EV_READ|EV_WRITE); 115 116 log_debug("run job %p: %s, pid %ld", job, job->cmd, (long) job->pid); 117 return (job); 118 } 119 120 /* Kill and free an individual job. */ 121 void 122 job_free(struct job *job) 123 { 124 log_debug("free job %p: %s", job, job->cmd); 125 126 LIST_REMOVE(job, lentry); 127 free(job->cmd); 128 129 if (job->freefn != NULL && job->data != NULL) 130 job->freefn(job->data); 131 132 if (job->pid != -1) 133 kill(job->pid, SIGTERM); 134 if (job->event != NULL) 135 bufferevent_free(job->event); 136 if (job->fd != -1) 137 close(job->fd); 138 139 free(job); 140 } 141 142 /* Called when output buffer falls below low watermark (default is 0). */ 143 void 144 job_write_callback(unused struct bufferevent *bufev, void *data) 145 { 146 struct job *job = data; 147 size_t len = EVBUFFER_LENGTH(EVBUFFER_OUTPUT(job->event)); 148 149 log_debug("job write %p: %s, pid %ld, output left %zu", job, job->cmd, 150 (long) job->pid, len); 151 152 if (len == 0) { 153 shutdown(job->fd, SHUT_WR); 154 bufferevent_disable(job->event, EV_WRITE); 155 } 156 } 157 158 /* Job buffer error callback. */ 159 void 160 job_callback(unused struct bufferevent *bufev, unused short events, void *data) 161 { 162 struct job *job = data; 163 164 log_debug("job error %p: %s, pid %ld", job, job->cmd, (long) job->pid); 165 166 if (job->pid == -1) { 167 if (job->callbackfn != NULL) 168 job->callbackfn(job); 169 job_free(job); 170 } else { 171 bufferevent_disable(job->event, EV_READ); 172 close(job->fd); 173 job->fd = -1; 174 } 175 } 176 177 /* Job died (waitpid() returned its pid). */ 178 void 179 job_died(struct job *job, int status) 180 { 181 log_debug("job died %p: %s, pid %ld", job, job->cmd, (long) job->pid); 182 183 job->status = status; 184 185 if (job->fd == -1) { 186 if (job->callbackfn != NULL) 187 job->callbackfn(job); 188 job_free(job); 189 } else 190 job->pid = -1; 191 } 192