.Op Fl b not .Fl b for run-shell synopsis, from Ben Boeckel.
[tmux-openbsd.git] / client.c
blob0c8657eb470992bec3ae20bc116ec7629281e72c
1 /* $OpenBSD$ */
3 /*
4 * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
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.
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.
19 #include <sys/types.h>
20 #include <sys/file.h>
21 #include <sys/socket.h>
22 #include <sys/stat.h>
23 #include <sys/un.h>
24 #include <sys/wait.h>
26 #include <errno.h>
27 #include <event.h>
28 #include <fcntl.h>
29 #include <pwd.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <unistd.h>
34 #include "tmux.h"
36 struct imsgbuf client_ibuf;
37 struct event client_event;
38 struct event client_stdin;
39 enum {
40 CLIENT_EXIT_NONE,
41 CLIENT_EXIT_DETACHED,
42 CLIENT_EXIT_DETACHED_HUP,
43 CLIENT_EXIT_LOST_TTY,
44 CLIENT_EXIT_TERMINATED,
45 CLIENT_EXIT_LOST_SERVER,
46 CLIENT_EXIT_EXITED,
47 CLIENT_EXIT_SERVER_EXITED,
48 } client_exitreason = CLIENT_EXIT_NONE;
49 int client_exitval;
50 enum msgtype client_exittype;
51 int client_attached;
53 int client_get_lock(char *);
54 int client_connect(char *, int);
55 void client_send_identify(int);
56 void client_send_environ(void);
57 void client_write_server(enum msgtype, void *, size_t);
58 void client_update_event(void);
59 void client_signal(int, short, void *);
60 void client_stdin_callback(int, short, void *);
61 void client_write(int, const char *, size_t);
62 void client_callback(int, short, void *);
63 int client_dispatch_attached(void);
64 int client_dispatch_wait(void *);
65 const char *client_exit_message(void);
68 * Get server create lock. If already held then server start is happening in
69 * another client, so block until the lock is released and return -1 to
70 * retry. Ignore other errors - just continue and start the server without the
71 * lock.
73 int
74 client_get_lock(char *lockfile)
76 int lockfd;
78 if ((lockfd = open(lockfile, O_WRONLY|O_CREAT, 0600)) == -1)
79 fatal("open failed");
81 if (lockf(lockfd, F_TLOCK, 0) == -1 && errno == EAGAIN) {
82 while (lockf(lockfd, F_LOCK, 0) == -1 && errno == EINTR)
83 /* nothing */;
84 close(lockfd);
85 return (-1);
88 return (lockfd);
91 /* Connect client to server. */
92 int
93 client_connect(char *path, int start_server)
95 struct sockaddr_un sa;
96 size_t size;
97 int fd, lockfd;
98 char *lockfile;
100 memset(&sa, 0, sizeof sa);
101 sa.sun_family = AF_UNIX;
102 size = strlcpy(sa.sun_path, path, sizeof sa.sun_path);
103 if (size >= sizeof sa.sun_path) {
104 errno = ENAMETOOLONG;
105 return (-1);
108 retry:
109 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
110 fatal("socket failed");
112 if (connect(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) == -1) {
113 if (errno != ECONNREFUSED && errno != ENOENT)
114 goto failed;
115 if (!start_server)
116 goto failed;
117 close(fd);
119 xasprintf(&lockfile, "%s.lock", path);
120 if ((lockfd = client_get_lock(lockfile)) == -1)
121 goto retry;
122 if (unlink(path) != 0 && errno != ENOENT)
123 return (-1);
124 fd = server_start(lockfd, lockfile);
125 free(lockfile);
126 close(lockfd);
129 setblocking(fd, 0);
130 return (fd);
132 failed:
133 close(fd);
134 return (-1);
137 /* Get exit string from reason number. */
138 const char *
139 client_exit_message(void)
141 switch (client_exitreason) {
142 case CLIENT_EXIT_NONE:
143 break;
144 case CLIENT_EXIT_DETACHED:
145 return ("detached");
146 case CLIENT_EXIT_DETACHED_HUP:
147 return ("detached and SIGHUP");
148 case CLIENT_EXIT_LOST_TTY:
149 return ("lost tty");
150 case CLIENT_EXIT_TERMINATED:
151 return ("terminated");
152 case CLIENT_EXIT_LOST_SERVER:
153 return ("lost server");
154 case CLIENT_EXIT_EXITED:
155 return ("exited");
156 case CLIENT_EXIT_SERVER_EXITED:
157 return ("server exited");
159 return ("unknown reason");
162 /* Client main loop. */
164 client_main(int argc, char **argv, int flags)
166 struct cmd *cmd;
167 struct cmd_list *cmdlist;
168 struct msg_command_data cmddata;
169 int cmdflags, fd;
170 pid_t ppid;
171 enum msgtype msg;
172 char *cause;
173 struct termios tio, saved_tio;
175 /* Set up the initial command. */
176 cmdflags = 0;
177 if (shell_cmd != NULL) {
178 msg = MSG_SHELL;
179 cmdflags = CMD_STARTSERVER;
180 } else if (argc == 0) {
181 msg = MSG_COMMAND;
182 cmdflags = CMD_STARTSERVER|CMD_SENDENVIRON|CMD_CANTNEST;
183 } else {
184 msg = MSG_COMMAND;
187 * It sucks parsing the command string twice (in client and
188 * later in server) but it is necessary to get the start server
189 * flag.
191 cmdlist = cmd_list_parse(argc, argv, NULL, 0, &cause);
192 if (cmdlist == NULL) {
193 fprintf(stderr, "%s\n", cause);
194 return (1);
196 cmdflags &= ~CMD_STARTSERVER;
197 TAILQ_FOREACH(cmd, &cmdlist->list, qentry) {
198 if (cmd->entry->flags & CMD_STARTSERVER)
199 cmdflags |= CMD_STARTSERVER;
200 if (cmd->entry->flags & CMD_SENDENVIRON)
201 cmdflags |= CMD_SENDENVIRON;
202 if (cmd->entry->flags & CMD_CANTNEST)
203 cmdflags |= CMD_CANTNEST;
205 cmd_list_free(cmdlist);
209 * Check if this could be a nested session, if the command can't nest:
210 * if the socket path matches $TMUX, this is probably the same server.
212 if (shell_cmd == NULL && environ_path != NULL &&
213 (cmdflags & CMD_CANTNEST) &&
214 strcmp(socket_path, environ_path) == 0) {
215 fprintf(stderr, "sessions should be nested with care, "
216 "unset $TMUX to force\n");
217 return (1);
220 /* Initialise the client socket and start the server. */
221 fd = client_connect(socket_path, cmdflags & CMD_STARTSERVER);
222 if (fd == -1) {
223 fprintf(stderr, "failed to connect to server\n");
224 return (1);
227 /* Set process title, log and signals now this is the client. */
228 setproctitle("client (%s)", socket_path);
229 logfile("client");
231 /* Create imsg. */
232 imsg_init(&client_ibuf, fd);
233 event_set(&client_event, fd, EV_READ, client_callback, shell_cmd);
235 /* Create stdin handler. */
236 setblocking(STDIN_FILENO, 0);
237 event_set(&client_stdin, STDIN_FILENO, EV_READ|EV_PERSIST,
238 client_stdin_callback, NULL);
239 if (flags & IDENTIFY_TERMIOS) {
240 if (tcgetattr(STDIN_FILENO, &saved_tio) != 0) {
241 fprintf(stderr, "tcgetattr failed: %s\n",
242 strerror(errno));
243 return (1);
245 cfmakeraw(&tio);
246 tio.c_iflag = ICRNL|IXANY;
247 tio.c_oflag = OPOST|ONLCR;
248 tio.c_lflag = NOKERNINFO;
249 tio.c_cflag = CREAD|CS8|HUPCL;
250 tio.c_cc[VMIN] = 1;
251 tio.c_cc[VTIME] = 0;
252 cfsetispeed(&tio, cfgetispeed(&saved_tio));
253 cfsetospeed(&tio, cfgetospeed(&saved_tio));
254 tcsetattr(STDIN_FILENO, TCSANOW, &tio);
257 /* Establish signal handlers. */
258 set_signals(client_signal);
260 /* Send initial environment. */
261 if (cmdflags & CMD_SENDENVIRON)
262 client_send_environ();
263 client_send_identify(flags);
265 /* Send first command. */
266 if (msg == MSG_COMMAND) {
267 /* Fill in command line arguments. */
268 cmddata.pid = environ_pid;
269 cmddata.session_id = environ_session_id;
271 /* Prepare command for server. */
272 cmddata.argc = argc;
273 if (cmd_pack_argv(
274 argc, argv, cmddata.argv, sizeof cmddata.argv) != 0) {
275 fprintf(stderr, "command too long\n");
276 return (1);
279 client_write_server(msg, &cmddata, sizeof cmddata);
280 } else if (msg == MSG_SHELL)
281 client_write_server(msg, NULL, 0);
283 /* Set the event and dispatch. */
284 client_update_event();
285 event_dispatch();
287 /* Print the exit message, if any, and exit. */
288 if (client_attached) {
289 if (client_exitreason != CLIENT_EXIT_NONE && !login_shell)
290 printf("[%s]\n", client_exit_message());
292 ppid = getppid();
293 if (client_exittype == MSG_DETACHKILL && ppid > 1)
294 kill(ppid, SIGHUP);
295 } else if (flags & IDENTIFY_TERMIOS) {
296 if (flags & IDENTIFY_CONTROL) {
297 if (client_exitreason != CLIENT_EXIT_NONE)
298 printf("%%exit %s\n", client_exit_message());
299 else
300 printf("%%exit\n");
301 printf("\033\\");
303 tcsetattr(STDOUT_FILENO, TCSAFLUSH, &saved_tio);
305 setblocking(STDIN_FILENO, 1);
306 return (client_exitval);
309 /* Send identify message to server with the file descriptors. */
310 void
311 client_send_identify(int flags)
313 struct msg_identify_data data;
314 char *term;
315 int fd;
317 data.flags = flags;
319 if (getcwd(data.cwd, sizeof data.cwd) == NULL)
320 *data.cwd = '\0';
322 term = getenv("TERM");
323 if (term == NULL ||
324 strlcpy(data.term, term, sizeof data.term) >= sizeof data.term)
325 *data.term = '\0';
327 if ((fd = dup(STDIN_FILENO)) == -1)
328 fatal("dup failed");
329 imsg_compose(&client_ibuf,
330 MSG_IDENTIFY, PROTOCOL_VERSION, -1, fd, &data, sizeof data);
331 client_update_event();
334 /* Forward entire environment to server. */
335 void
336 client_send_environ(void)
338 struct msg_environ_data data;
339 char **var;
341 for (var = environ; *var != NULL; var++) {
342 if (strlcpy(data.var, *var, sizeof data.var) >= sizeof data.var)
343 continue;
344 client_write_server(MSG_ENVIRON, &data, sizeof data);
348 /* Write a message to the server without a file descriptor. */
349 void
350 client_write_server(enum msgtype type, void *buf, size_t len)
352 imsg_compose(&client_ibuf, type, PROTOCOL_VERSION, -1, -1, buf, len);
353 client_update_event();
356 /* Update client event based on whether it needs to read or read and write. */
357 void
358 client_update_event(void)
360 short events;
362 event_del(&client_event);
363 events = EV_READ;
364 if (client_ibuf.w.queued > 0)
365 events |= EV_WRITE;
366 event_set(
367 &client_event, client_ibuf.fd, events, client_callback, shell_cmd);
368 event_add(&client_event, NULL);
371 /* Callback to handle signals in the client. */
372 void
373 client_signal(int sig, unused short events, unused void *data)
375 struct sigaction sigact;
376 int status;
378 if (!client_attached) {
379 switch (sig) {
380 case SIGCHLD:
381 waitpid(WAIT_ANY, &status, WNOHANG);
382 break;
383 case SIGTERM:
384 event_loopexit(NULL);
385 break;
387 } else {
388 switch (sig) {
389 case SIGHUP:
390 client_exitreason = CLIENT_EXIT_LOST_TTY;
391 client_exitval = 1;
392 client_write_server(MSG_EXITING, NULL, 0);
393 break;
394 case SIGTERM:
395 client_exitreason = CLIENT_EXIT_TERMINATED;
396 client_exitval = 1;
397 client_write_server(MSG_EXITING, NULL, 0);
398 break;
399 case SIGWINCH:
400 client_write_server(MSG_RESIZE, NULL, 0);
401 break;
402 case SIGCONT:
403 memset(&sigact, 0, sizeof sigact);
404 sigemptyset(&sigact.sa_mask);
405 sigact.sa_flags = SA_RESTART;
406 sigact.sa_handler = SIG_IGN;
407 if (sigaction(SIGTSTP, &sigact, NULL) != 0)
408 fatal("sigaction failed");
409 client_write_server(MSG_WAKEUP, NULL, 0);
410 break;
414 client_update_event();
417 /* Callback for client imsg read events. */
418 void
419 client_callback(unused int fd, short events, void *data)
421 ssize_t n;
422 int retval;
424 if (events & EV_READ) {
425 if ((n = imsg_read(&client_ibuf)) == -1 || n == 0)
426 goto lost_server;
427 if (client_attached)
428 retval = client_dispatch_attached();
429 else
430 retval = client_dispatch_wait(data);
431 if (retval != 0) {
432 event_loopexit(NULL);
433 return;
437 if (events & EV_WRITE) {
438 if (msgbuf_write(&client_ibuf.w) < 0)
439 goto lost_server;
442 client_update_event();
443 return;
445 lost_server:
446 client_exitreason = CLIENT_EXIT_LOST_SERVER;
447 client_exitval = 1;
448 event_loopexit(NULL);
451 /* Callback for client stdin read events. */
452 void
453 client_stdin_callback(unused int fd, unused short events, unused void *data1)
455 struct msg_stdin_data data;
457 data.size = read(STDIN_FILENO, data.data, sizeof data.data);
458 if (data.size < 0 && (errno == EINTR || errno == EAGAIN))
459 return;
461 client_write_server(MSG_STDIN, &data, sizeof data);
462 if (data.size <= 0)
463 event_del(&client_stdin);
464 client_update_event();
467 /* Force write to file descriptor. */
468 void
469 client_write(int fd, const char *data, size_t size)
471 ssize_t used;
473 while (size != 0) {
474 used = write(fd, data, size);
475 if (used == -1) {
476 if (errno == EINTR || errno == EAGAIN)
477 continue;
478 break;
480 data += used;
481 size -= used;
485 /* Dispatch imsgs when in wait state (before MSG_READY). */
487 client_dispatch_wait(void *data)
489 struct imsg imsg;
490 ssize_t n, datalen;
491 struct msg_shell_data shelldata;
492 struct msg_exit_data exitdata;
493 struct msg_stdout_data stdoutdata;
494 struct msg_stderr_data stderrdata;
495 const char *shellcmd = data;
497 for (;;) {
498 if ((n = imsg_get(&client_ibuf, &imsg)) == -1)
499 fatalx("imsg_get failed");
500 if (n == 0)
501 return (0);
502 datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
504 log_debug("got %d from server", imsg.hdr.type);
505 switch (imsg.hdr.type) {
506 case MSG_EXIT:
507 case MSG_SHUTDOWN:
508 if (datalen != sizeof exitdata) {
509 if (datalen != 0)
510 fatalx("bad MSG_EXIT size");
511 } else {
512 memcpy(&exitdata, imsg.data, sizeof exitdata);
513 client_exitval = exitdata.retcode;
515 imsg_free(&imsg);
516 return (-1);
517 case MSG_READY:
518 if (datalen != 0)
519 fatalx("bad MSG_READY size");
521 event_del(&client_stdin);
522 client_attached = 1;
523 client_write_server(MSG_RESIZE, NULL, 0);
524 break;
525 case MSG_STDIN:
526 if (datalen != 0)
527 fatalx("bad MSG_STDIN size");
529 event_add(&client_stdin, NULL);
530 break;
531 case MSG_STDOUT:
532 if (datalen != sizeof stdoutdata)
533 fatalx("bad MSG_STDOUT");
534 memcpy(&stdoutdata, imsg.data, sizeof stdoutdata);
536 client_write(STDOUT_FILENO, stdoutdata.data, stdoutdata.size);
537 break;
538 case MSG_STDERR:
539 if (datalen != sizeof stderrdata)
540 fatalx("bad MSG_STDERR");
541 memcpy(&stderrdata, imsg.data, sizeof stderrdata);
543 client_write(STDERR_FILENO, stderrdata.data, stderrdata.size);
544 break;
545 case MSG_VERSION:
546 if (datalen != 0)
547 fatalx("bad MSG_VERSION size");
549 fprintf(stderr, "protocol version mismatch "
550 "(client %u, server %u)\n", PROTOCOL_VERSION,
551 imsg.hdr.peerid);
552 client_exitval = 1;
554 imsg_free(&imsg);
555 return (-1);
556 case MSG_SHELL:
557 if (datalen != sizeof shelldata)
558 fatalx("bad MSG_SHELL size");
559 memcpy(&shelldata, imsg.data, sizeof shelldata);
560 shelldata.shell[(sizeof shelldata.shell) - 1] = '\0';
562 clear_signals(0);
564 shell_exec(shelldata.shell, shellcmd);
565 /* NOTREACHED */
566 case MSG_DETACH:
567 client_write_server(MSG_EXITING, NULL, 0);
568 break;
569 case MSG_EXITED:
570 imsg_free(&imsg);
571 return (-1);
572 default:
573 fatalx("unexpected message");
576 imsg_free(&imsg);
580 /* Dispatch imsgs in attached state (after MSG_READY). */
582 client_dispatch_attached(void)
584 struct imsg imsg;
585 struct msg_lock_data lockdata;
586 struct sigaction sigact;
587 ssize_t n, datalen;
589 for (;;) {
590 if ((n = imsg_get(&client_ibuf, &imsg)) == -1)
591 fatalx("imsg_get failed");
592 if (n == 0)
593 return (0);
594 datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
596 log_debug("got %d from server", imsg.hdr.type);
597 switch (imsg.hdr.type) {
598 case MSG_DETACHKILL:
599 case MSG_DETACH:
600 if (datalen != 0)
601 fatalx("bad MSG_DETACH size");
603 client_exittype = imsg.hdr.type;
604 if (imsg.hdr.type == MSG_DETACHKILL)
605 client_exitreason = CLIENT_EXIT_DETACHED_HUP;
606 else
607 client_exitreason = CLIENT_EXIT_DETACHED;
608 client_write_server(MSG_EXITING, NULL, 0);
609 break;
610 case MSG_EXIT:
611 if (datalen != 0 &&
612 datalen != sizeof (struct msg_exit_data))
613 fatalx("bad MSG_EXIT size");
615 client_write_server(MSG_EXITING, NULL, 0);
616 client_exitreason = CLIENT_EXIT_EXITED;
617 break;
618 case MSG_EXITED:
619 if (datalen != 0)
620 fatalx("bad MSG_EXITED size");
622 imsg_free(&imsg);
623 return (-1);
624 case MSG_SHUTDOWN:
625 if (datalen != 0)
626 fatalx("bad MSG_SHUTDOWN size");
628 client_write_server(MSG_EXITING, NULL, 0);
629 client_exitreason = CLIENT_EXIT_SERVER_EXITED;
630 client_exitval = 1;
631 break;
632 case MSG_SUSPEND:
633 if (datalen != 0)
634 fatalx("bad MSG_SUSPEND size");
636 memset(&sigact, 0, sizeof sigact);
637 sigemptyset(&sigact.sa_mask);
638 sigact.sa_flags = SA_RESTART;
639 sigact.sa_handler = SIG_DFL;
640 if (sigaction(SIGTSTP, &sigact, NULL) != 0)
641 fatal("sigaction failed");
642 kill(getpid(), SIGTSTP);
643 break;
644 case MSG_LOCK:
645 if (datalen != sizeof lockdata)
646 fatalx("bad MSG_LOCK size");
647 memcpy(&lockdata, imsg.data, sizeof lockdata);
649 lockdata.cmd[(sizeof lockdata.cmd) - 1] = '\0';
650 system(lockdata.cmd);
651 client_write_server(MSG_UNLOCK, NULL, 0);
652 break;
653 default:
654 fatalx("unexpected message");
657 imsg_free(&imsg);