1 /* $OpenBSD$ */ 2 3 /* 4 * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com> 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 <signal.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, const char *cwd, 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 const char *home; 51 52 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, out) != 0) 53 return (NULL); 54 55 env = environ_create(); 56 environ_copy(global_environ, env); 57 if (s != NULL) 58 environ_copy(s->environ, env); 59 server_fill_environ(s, env); 60 61 switch (pid = fork()) { 62 case -1: 63 environ_free(env); 64 close(out[0]); 65 close(out[1]); 66 return (NULL); 67 case 0: /* child */ 68 clear_signals(1); 69 70 if (cwd == NULL || chdir(cwd) != 0) { 71 if ((home = find_home()) == NULL || chdir(home) != 0) 72 chdir("/"); 73 } 74 75 environ_push(env); 76 environ_free(env); 77 78 if (dup2(out[1], STDIN_FILENO) == -1) 79 fatal("dup2 failed"); 80 if (dup2(out[1], STDOUT_FILENO) == -1) 81 fatal("dup2 failed"); 82 if (out[1] != STDIN_FILENO && out[1] != STDOUT_FILENO) 83 close(out[1]); 84 close(out[0]); 85 86 nullfd = open(_PATH_DEVNULL, O_RDWR, 0); 87 if (nullfd < 0) 88 fatal("open failed"); 89 if (dup2(nullfd, STDERR_FILENO) == -1) 90 fatal("dup2 failed"); 91 if (nullfd != STDERR_FILENO) 92 close(nullfd); 93 94 closefrom(STDERR_FILENO + 1); 95 96 execl(_PATH_BSHELL, "sh", "-c", cmd, (char *) NULL); 97 fatal("execl failed"); 98 } 99 100 /* parent */ 101 environ_free(env); 102 close(out[1]); 103 104 job = xmalloc(sizeof *job); 105 job->state = JOB_RUNNING; 106 107 job->cmd = xstrdup(cmd); 108 job->pid = pid; 109 job->status = 0; 110 111 LIST_INSERT_HEAD(&all_jobs, job, lentry); 112 113 job->callbackfn = callbackfn; 114 job->freefn = freefn; 115 job->data = data; 116 117 job->fd = out[0]; 118 setblocking(job->fd, 0); 119 120 job->event = bufferevent_new(job->fd, NULL, job_write_callback, 121 job_callback, job); 122 bufferevent_enable(job->event, EV_READ|EV_WRITE); 123 124 log_debug("run job %p: %s, pid %ld", job, job->cmd, (long) job->pid); 125 return (job); 126 } 127 128 /* Kill and free an individual job. */ 129 void 130 job_free(struct job *job) 131 { 132 log_debug("free job %p: %s", job, job->cmd); 133 134 LIST_REMOVE(job, lentry); 135 free(job->cmd); 136 137 if (job->freefn != NULL && job->data != NULL) 138 job->freefn(job->data); 139 140 if (job->pid != -1) 141 kill(job->pid, SIGTERM); 142 if (job->event != NULL) 143 bufferevent_free(job->event); 144 if (job->fd != -1) 145 close(job->fd); 146 147 free(job); 148 } 149 150 /* Called when output buffer falls below low watermark (default is 0). */ 151 void 152 job_write_callback(__unused struct bufferevent *bufev, void *data) 153 { 154 struct job *job = data; 155 size_t len = EVBUFFER_LENGTH(EVBUFFER_OUTPUT(job->event)); 156 157 log_debug("job write %p: %s, pid %ld, output left %zu", job, job->cmd, 158 (long) job->pid, len); 159 160 if (len == 0) { 161 shutdown(job->fd, SHUT_WR); 162 bufferevent_disable(job->event, EV_WRITE); 163 } 164 } 165 166 /* Job buffer error callback. */ 167 void 168 job_callback(__unused struct bufferevent *bufev, __unused short events, 169 void *data) 170 { 171 struct job *job = data; 172 173 log_debug("job error %p: %s, pid %ld", job, job->cmd, (long) job->pid); 174 175 if (job->state == JOB_DEAD) { 176 if (job->callbackfn != NULL) 177 job->callbackfn(job); 178 job_free(job); 179 } else { 180 bufferevent_disable(job->event, EV_READ); 181 job->state = JOB_CLOSED; 182 } 183 } 184 185 /* Job died (waitpid() returned its pid). */ 186 void 187 job_died(struct job *job, int status) 188 { 189 log_debug("job died %p: %s, pid %ld", job, job->cmd, (long) job->pid); 190 191 job->status = status; 192 193 if (job->state == JOB_CLOSED) { 194 if (job->callbackfn != NULL) 195 job->callbackfn(job); 196 job_free(job); 197 } else { 198 job->pid = -1; 199 job->state = JOB_DEAD; 200 } 201 } 202