[b18544]: client.c Maximize Restore History

Download this file

client.c    691 lines (604 with data), 16.8 kB

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
/* $OpenBSD$ */
/*
* Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <errno.h>
#include <event.h>
#include <fcntl.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "tmux.h"
struct imsgbuf client_ibuf;
struct event client_event;
struct event client_stdin;
enum {
CLIENT_EXIT_NONE,
CLIENT_EXIT_DETACHED,
CLIENT_EXIT_DETACHED_HUP,
CLIENT_EXIT_LOST_TTY,
CLIENT_EXIT_TERMINATED,
CLIENT_EXIT_LOST_SERVER,
CLIENT_EXIT_EXITED,
CLIENT_EXIT_SERVER_EXITED,
} client_exitreason = CLIENT_EXIT_NONE;
int client_exitval;
enum msgtype client_exittype;
const char *client_exitsession;
int client_attached;
int client_get_lock(char *);
int client_connect(char *, int);
void client_send_identify(int);
int client_write_one(enum msgtype, int, const void *, size_t);
int client_write_server(enum msgtype, const void *, size_t);
void client_update_event(void);
void client_signal(int, short, void *);
void client_stdin_callback(int, short, void *);
void client_write(int, const char *, size_t);
void client_callback(int, short, void *);
int client_dispatch_attached(void);
int client_dispatch_wait(void *);
const char *client_exit_message(void);
/*
* Get server create lock. If already held then server start is happening in
* another client, so block until the lock is released and return -1 to
* retry. Ignore other errors - just continue and start the server without the
* lock.
*/
int
client_get_lock(char *lockfile)
{
int lockfd;
if ((lockfd = open(lockfile, O_WRONLY|O_CREAT, 0600)) == -1)
fatal("open failed");
if (lockf(lockfd, F_TLOCK, 0) == -1 && errno == EAGAIN) {
while (lockf(lockfd, F_LOCK, 0) == -1 && errno == EINTR)
/* nothing */;
close(lockfd);
return (-1);
}
return (lockfd);
}
/* Connect client to server. */
int
client_connect(char *path, int start_server)
{
struct sockaddr_un sa;
size_t size;
int fd, lockfd;
char *lockfile;
memset(&sa, 0, sizeof sa);
sa.sun_family = AF_UNIX;
size = strlcpy(sa.sun_path, path, sizeof sa.sun_path);
if (size >= sizeof sa.sun_path) {
errno = ENAMETOOLONG;
return (-1);
}
retry:
if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
fatal("socket failed");
if (connect(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) == -1) {
if (errno != ECONNREFUSED && errno != ENOENT)
goto failed;
if (!start_server)
goto failed;
close(fd);
xasprintf(&lockfile, "%s.lock", path);
if ((lockfd = client_get_lock(lockfile)) == -1) {
free(lockfile);
goto retry;
}
if (unlink(path) != 0 && errno != ENOENT) {
free(lockfile);
close(lockfd);
return (-1);
}
fd = server_start(lockfd, lockfile);
free(lockfile);
close(lockfd);
}
setblocking(fd, 0);
return (fd);
failed:
close(fd);
return (-1);
}
/* Get exit string from reason number. */
const char *
client_exit_message(void)
{
static char msg[256];
switch (client_exitreason) {
case CLIENT_EXIT_NONE:
break;
case CLIENT_EXIT_DETACHED:
if (client_exitsession != NULL) {
xsnprintf(msg, sizeof msg, "detached "
"(from session %s)", client_exitsession);
return (msg);
}
return ("detached");
case CLIENT_EXIT_DETACHED_HUP:
if (client_exitsession != NULL) {
xsnprintf(msg, sizeof msg, "detached and SIGHUP "
"(from session %s)", client_exitsession);
return (msg);
}
return ("detached and SIGHUP");
case CLIENT_EXIT_LOST_TTY:
return ("lost tty");
case CLIENT_EXIT_TERMINATED:
return ("terminated");
case CLIENT_EXIT_LOST_SERVER:
return ("lost server");
case CLIENT_EXIT_EXITED:
return ("exited");
case CLIENT_EXIT_SERVER_EXITED:
return ("server exited");
}
return ("unknown reason");
}
/* Client main loop. */
int
client_main(int argc, char **argv, int flags)
{
struct cmd *cmd;
struct cmd_list *cmdlist;
struct msg_command_data *data;
int cmdflags, fd, i;
pid_t ppid;
enum msgtype msg;
char *cause;
struct termios tio, saved_tio;
size_t size;
/* Set up the initial command. */
cmdflags = 0;
if (shell_cmd != NULL) {
msg = MSG_SHELL;
cmdflags = CMD_STARTSERVER;
} else if (argc == 0) {
msg = MSG_COMMAND;
cmdflags = CMD_STARTSERVER|CMD_CANTNEST;
} else {
msg = MSG_COMMAND;
/*
* It sucks parsing the command string twice (in client and
* later in server) but it is necessary to get the start server
* flag.
*/
cmdlist = cmd_list_parse(argc, argv, NULL, 0, &cause);
if (cmdlist == NULL) {
fprintf(stderr, "%s\n", cause);
return (1);
}
cmdflags &= ~CMD_STARTSERVER;
TAILQ_FOREACH(cmd, &cmdlist->list, qentry) {
if (cmd->entry->flags & CMD_STARTSERVER)
cmdflags |= CMD_STARTSERVER;
if (cmd->entry->flags & CMD_CANTNEST)
cmdflags |= CMD_CANTNEST;
}
cmd_list_free(cmdlist);
}
/*
* Check if this could be a nested session, if the command can't nest:
* if the socket path matches $TMUX, this is probably the same server.
*/
if (shell_cmd == NULL && environ_path != NULL &&
(cmdflags & CMD_CANTNEST) &&
strcmp(socket_path, environ_path) == 0) {
fprintf(stderr, "sessions should be nested with care, "
"unset $TMUX to force\n");
return (1);
}
/* Initialise the client socket and start the server. */
fd = client_connect(socket_path, cmdflags & CMD_STARTSERVER);
if (fd == -1) {
fprintf(stderr, "failed to connect to server: %s\n",
strerror(errno));
return (1);
}
/* Set process title, log and signals now this is the client. */
setproctitle("client (%s)", socket_path);
logfile("client");
/* Create imsg. */
imsg_init(&client_ibuf, fd);
event_set(&client_event, fd, EV_READ, client_callback, shell_cmd);
/* Create stdin handler. */
setblocking(STDIN_FILENO, 0);
event_set(&client_stdin, STDIN_FILENO, EV_READ|EV_PERSIST,
client_stdin_callback, NULL);
if (flags & CLIENT_CONTROLCONTROL) {
if (tcgetattr(STDIN_FILENO, &saved_tio) != 0) {
fprintf(stderr, "tcgetattr failed: %s\n",
strerror(errno));
return (1);
}
cfmakeraw(&tio);
tio.c_iflag = ICRNL|IXANY;
tio.c_oflag = OPOST|ONLCR;
tio.c_lflag = NOKERNINFO;
tio.c_cflag = CREAD|CS8|HUPCL;
tio.c_cc[VMIN] = 1;
tio.c_cc[VTIME] = 0;
cfsetispeed(&tio, cfgetispeed(&saved_tio));
cfsetospeed(&tio, cfgetospeed(&saved_tio));
tcsetattr(STDIN_FILENO, TCSANOW, &tio);
}
/* Establish signal handlers. */
set_signals(client_signal);
/* Send identify messages. */
client_send_identify(flags);
/* Send first command. */
if (msg == MSG_COMMAND) {
/* How big is the command? */
size = 0;
for (i = 0; i < argc; i++)
size += strlen(argv[i]) + 1;
data = xmalloc((sizeof *data) + size);
/* Prepare command for server. */
data->argc = argc;
if (cmd_pack_argv(argc, argv, (char*)(data + 1), size) != 0) {
fprintf(stderr, "command too long\n");
free(data);
return (1);
}
size += sizeof *data;
/* Send the command. */
if (client_write_server(msg, data, size) != 0) {
fprintf(stderr, "failed to send command\n");
free(data);
return (1);
}
free(data);
} else if (msg == MSG_SHELL)
client_write_server(msg, NULL, 0);
/* Set the event and dispatch. */
client_update_event();
event_dispatch();
/* Print the exit message, if any, and exit. */
if (client_attached) {
if (client_exitreason != CLIENT_EXIT_NONE && !login_shell)
printf("[%s]\n", client_exit_message());
ppid = getppid();
if (client_exittype == MSG_DETACHKILL && ppid > 1)
kill(ppid, SIGHUP);
} else if (flags & CLIENT_CONTROLCONTROL) {
if (client_exitreason != CLIENT_EXIT_NONE)
printf("%%exit %s\n", client_exit_message());
else
printf("%%exit\n");
printf("\033\\");
tcsetattr(STDOUT_FILENO, TCSAFLUSH, &saved_tio);
}
setblocking(STDIN_FILENO, 1);
return (client_exitval);
}
/* Send identify messages to server. */
void
client_send_identify(int flags)
{
const char *s;
char **ss;
int fd;
client_write_one(MSG_IDENTIFY_FLAGS, -1, &flags, sizeof flags);
if ((s = getenv("TERM")) == NULL)
s = "";
client_write_one(MSG_IDENTIFY_TERM, -1, s, strlen(s) + 1);
if ((s = ttyname(STDIN_FILENO)) == NULL)
s = "";
client_write_one(MSG_IDENTIFY_TTYNAME, -1, s, strlen(s) + 1);
if ((fd = open(".", O_RDONLY)) == -1)
fd = open("/", O_RDONLY);
client_write_one(MSG_IDENTIFY_CWD, fd, NULL, 0);
if ((fd = dup(STDIN_FILENO)) == -1)
fatal("dup failed");
client_write_one(MSG_IDENTIFY_STDIN, fd, NULL, 0);
for (ss = environ; *ss != NULL; ss++)
client_write_one(MSG_IDENTIFY_ENVIRON, -1, *ss, strlen(*ss) + 1);
client_write_one(MSG_IDENTIFY_DONE, -1, NULL, 0);
client_update_event();
}
/* Helper to send one message. */
int
client_write_one(enum msgtype type, int fd, const void *buf, size_t len)
{
int retval;
retval = imsg_compose(&client_ibuf, type, PROTOCOL_VERSION, -1, fd,
(void*)buf, len);
if (retval != 1)
return (-1);
return (0);
}
/* Write a message to the server without a file descriptor. */
int
client_write_server(enum msgtype type, const void *buf, size_t len)
{
int retval;
retval = client_write_one(type, -1, buf, len);
if (retval == 0)
client_update_event();
return (retval);
}
/* Update client event based on whether it needs to read or read and write. */
void
client_update_event(void)
{
short events;
event_del(&client_event);
events = EV_READ;
if (client_ibuf.w.queued > 0)
events |= EV_WRITE;
event_set(
&client_event, client_ibuf.fd, events, client_callback, shell_cmd);
event_add(&client_event, NULL);
}
/* Callback to handle signals in the client. */
void
client_signal(int sig, unused short events, unused void *data)
{
struct sigaction sigact;
int status;
if (!client_attached) {
switch (sig) {
case SIGCHLD:
waitpid(WAIT_ANY, &status, WNOHANG);
break;
case SIGTERM:
event_loopexit(NULL);
break;
}
} else {
switch (sig) {
case SIGHUP:
client_exitreason = CLIENT_EXIT_LOST_TTY;
client_exitval = 1;
client_write_server(MSG_EXITING, NULL, 0);
break;
case SIGTERM:
client_exitreason = CLIENT_EXIT_TERMINATED;
client_exitval = 1;
client_write_server(MSG_EXITING, NULL, 0);
break;
case SIGWINCH:
client_write_server(MSG_RESIZE, NULL, 0);
break;
case SIGCONT:
memset(&sigact, 0, sizeof sigact);
sigemptyset(&sigact.sa_mask);
sigact.sa_flags = SA_RESTART;
sigact.sa_handler = SIG_IGN;
if (sigaction(SIGTSTP, &sigact, NULL) != 0)
fatal("sigaction failed");
client_write_server(MSG_WAKEUP, NULL, 0);
break;
}
}
client_update_event();
}
/* Callback for client imsg read events. */
void
client_callback(unused int fd, short events, void *data)
{
ssize_t n;
int retval;
if (events & EV_READ) {
if ((n = imsg_read(&client_ibuf)) == -1 || n == 0)
goto lost_server;
if (client_attached)
retval = client_dispatch_attached();
else
retval = client_dispatch_wait(data);
if (retval != 0) {
event_loopexit(NULL);
return;
}
}
if (events & EV_WRITE) {
if (msgbuf_write(&client_ibuf.w) < 0 && errno != EAGAIN)
goto lost_server;
}
client_update_event();
return;
lost_server:
client_exitreason = CLIENT_EXIT_LOST_SERVER;
client_exitval = 1;
event_loopexit(NULL);
}
/* Callback for client stdin read events. */
void
client_stdin_callback(unused int fd, unused short events, unused void *data1)
{
struct msg_stdin_data data;
data.size = read(STDIN_FILENO, data.data, sizeof data.data);
if (data.size < 0 && (errno == EINTR || errno == EAGAIN))
return;
client_write_server(MSG_STDIN, &data, sizeof data);
if (data.size <= 0)
event_del(&client_stdin);
client_update_event();
}
/* Force write to file descriptor. */
void
client_write(int fd, const char *data, size_t size)
{
ssize_t used;
while (size != 0) {
used = write(fd, data, size);
if (used == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
break;
}
data += used;
size -= used;
}
}
/* Dispatch imsgs when in wait state (before MSG_READY). */
int
client_dispatch_wait(void *data0)
{
struct imsg imsg;
char *data;
ssize_t n, datalen;
struct msg_stdout_data stdoutdata;
struct msg_stderr_data stderrdata;
int retval;
for (;;) {
if ((n = imsg_get(&client_ibuf, &imsg)) == -1)
fatalx("imsg_get failed");
if (n == 0)
return (0);
data = imsg.data;
datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
log_debug("got %d from server", imsg.hdr.type);
switch (imsg.hdr.type) {
case MSG_EXIT:
case MSG_SHUTDOWN:
if (datalen != sizeof retval && datalen != 0)
fatalx("bad MSG_EXIT size");
if (datalen == sizeof retval) {
memcpy(&retval, data, sizeof retval);
client_exitval = retval;
}
imsg_free(&imsg);
return (-1);
case MSG_READY:
if (datalen != 0)
fatalx("bad MSG_READY size");
event_del(&client_stdin);
client_attached = 1;
client_write_server(MSG_RESIZE, NULL, 0);
break;
case MSG_STDIN:
if (datalen != 0)
fatalx("bad MSG_STDIN size");
event_add(&client_stdin, NULL);
break;
case MSG_STDOUT:
if (datalen != sizeof stdoutdata)
fatalx("bad MSG_STDOUT size");
memcpy(&stdoutdata, data, sizeof stdoutdata);
client_write(STDOUT_FILENO, stdoutdata.data,
stdoutdata.size);
break;
case MSG_STDERR:
if (datalen != sizeof stderrdata)
fatalx("bad MSG_STDERR size");
memcpy(&stderrdata, data, sizeof stderrdata);
client_write(STDERR_FILENO, stderrdata.data,
stderrdata.size);
break;
case MSG_VERSION:
if (datalen != 0)
fatalx("bad MSG_VERSION size");
fprintf(stderr, "protocol version mismatch "
"(client %u, server %u)\n", PROTOCOL_VERSION,
imsg.hdr.peerid);
client_exitval = 1;
imsg_free(&imsg);
return (-1);
case MSG_SHELL:
if (datalen == 0 || data[datalen - 1] != '\0')
fatalx("bad MSG_SHELL string");
clear_signals(0);
shell_exec(data, data0);
/* NOTREACHED */
case MSG_DETACH:
case MSG_DETACHKILL:
client_write_server(MSG_EXITING, NULL, 0);
break;
case MSG_EXITED:
imsg_free(&imsg);
return (-1);
}
imsg_free(&imsg);
}
}
/* Dispatch imsgs in attached state (after MSG_READY). */
int
client_dispatch_attached(void)
{
struct imsg imsg;
struct sigaction sigact;
char *data;
ssize_t n, datalen;
for (;;) {
if ((n = imsg_get(&client_ibuf, &imsg)) == -1)
fatalx("imsg_get failed");
if (n == 0)
return (0);
data = imsg.data;
datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
log_debug("got %d from server", imsg.hdr.type);
switch (imsg.hdr.type) {
case MSG_DETACH:
case MSG_DETACHKILL:
if (datalen == 0 || data[datalen - 1] != '\0')
fatalx("bad MSG_DETACH string");
client_exitsession = xstrdup(data);
client_exittype = imsg.hdr.type;
if (imsg.hdr.type == MSG_DETACHKILL)
client_exitreason = CLIENT_EXIT_DETACHED_HUP;
else
client_exitreason = CLIENT_EXIT_DETACHED;
client_write_server(MSG_EXITING, NULL, 0);
break;
case MSG_EXIT:
if (datalen != 0 && datalen != sizeof (int))
fatalx("bad MSG_EXIT size");
client_write_server(MSG_EXITING, NULL, 0);
client_exitreason = CLIENT_EXIT_EXITED;
break;
case MSG_EXITED:
if (datalen != 0)
fatalx("bad MSG_EXITED size");
imsg_free(&imsg);
return (-1);
case MSG_SHUTDOWN:
if (datalen != 0)
fatalx("bad MSG_SHUTDOWN size");
client_write_server(MSG_EXITING, NULL, 0);
client_exitreason = CLIENT_EXIT_SERVER_EXITED;
client_exitval = 1;
break;
case MSG_SUSPEND:
if (datalen != 0)
fatalx("bad MSG_SUSPEND size");
memset(&sigact, 0, sizeof sigact);
sigemptyset(&sigact.sa_mask);
sigact.sa_flags = SA_RESTART;
sigact.sa_handler = SIG_DFL;
if (sigaction(SIGTSTP, &sigact, NULL) != 0)
fatal("sigaction failed");
kill(getpid(), SIGTSTP);
break;
case MSG_LOCK:
if (datalen == 0 || data[datalen - 1] != '\0')
fatalx("bad MSG_LOCK string");
system(data);
client_write_server(MSG_UNLOCK, NULL, 0);
break;
}
imsg_free(&imsg);
}
}