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Commit | Line | Data |
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4ba93280 LP |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2010-2013 Lennart Poettering | |
5 | ||
6 | systemd is free software; you can redistribute it and/or modify it | |
7 | under the terms of the GNU Lesser General Public License as published by | |
8 | the Free Software Foundation; either version 2.1 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | systemd is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public License | |
17 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
18 | ***/ | |
19 | ||
a8fbdf54 | 20 | #include <errno.h> |
cf0fbc49 | 21 | #include <limits.h> |
a8fbdf54 TA |
22 | #include <signal.h> |
23 | #include <stddef.h> | |
24 | #include <stdint.h> | |
25 | #include <stdlib.h> | |
26 | #include <string.h> | |
4ba93280 | 27 | #include <sys/epoll.h> |
4ba93280 | 28 | #include <sys/ioctl.h> |
a8fbdf54 | 29 | #include <sys/time.h> |
4ba93280 | 30 | #include <termios.h> |
a8fbdf54 TA |
31 | #include <unistd.h> |
32 | ||
33 | #include "sd-event.h" | |
4ba93280 | 34 | |
b5efdb8a | 35 | #include "alloc-util.h" |
3ffd4af2 | 36 | #include "fd-util.h" |
a8fbdf54 TA |
37 | #include "log.h" |
38 | #include "macro.h" | |
4ba93280 | 39 | #include "ptyfwd.h" |
a8fbdf54 | 40 | #include "time-util.h" |
4ba93280 | 41 | |
023fb90b LP |
42 | struct PTYForward { |
43 | sd_event *event; | |
04d39279 | 44 | |
023fb90b LP |
45 | int master; |
46 | ||
ae3dde80 LP |
47 | PTYForwardFlags flags; |
48 | ||
023fb90b LP |
49 | sd_event_source *stdin_event_source; |
50 | sd_event_source *stdout_event_source; | |
51 | sd_event_source *master_event_source; | |
52 | ||
53 | sd_event_source *sigwinch_event_source; | |
54 | ||
55 | struct termios saved_stdin_attr; | |
56 | struct termios saved_stdout_attr; | |
57 | ||
58 | bool saved_stdin:1; | |
59 | bool saved_stdout:1; | |
60 | ||
61 | bool stdin_readable:1; | |
62 | bool stdin_hangup:1; | |
63 | bool stdout_writable:1; | |
64 | bool stdout_hangup:1; | |
65 | bool master_readable:1; | |
66 | bool master_writable:1; | |
67 | bool master_hangup:1; | |
68 | ||
ae3dde80 | 69 | bool read_from_master:1; |
9b15b784 LP |
70 | |
71 | bool last_char_set:1; | |
72 | char last_char; | |
73 | ||
023fb90b LP |
74 | char in_buffer[LINE_MAX], out_buffer[LINE_MAX]; |
75 | size_t in_buffer_full, out_buffer_full; | |
76 | ||
77 | usec_t escape_timestamp; | |
78 | unsigned escape_counter; | |
79 | }; | |
80 | ||
81 | #define ESCAPE_USEC (1*USEC_PER_SEC) | |
82 | ||
83 | static bool look_for_escape(PTYForward *f, const char *buffer, size_t n) { | |
04d39279 LP |
84 | const char *p; |
85 | ||
023fb90b | 86 | assert(f); |
04d39279 LP |
87 | assert(buffer); |
88 | assert(n > 0); | |
89 | ||
90 | for (p = buffer; p < buffer + n; p++) { | |
91 | ||
92 | /* Check for ^] */ | |
93 | if (*p == 0x1D) { | |
94 | usec_t nw = now(CLOCK_MONOTONIC); | |
95 | ||
023fb90b LP |
96 | if (f->escape_counter == 0 || nw > f->escape_timestamp + ESCAPE_USEC) { |
97 | f->escape_timestamp = nw; | |
98 | f->escape_counter = 1; | |
04d39279 | 99 | } else { |
023fb90b | 100 | (f->escape_counter)++; |
04d39279 | 101 | |
023fb90b | 102 | if (f->escape_counter >= 3) |
04d39279 LP |
103 | return true; |
104 | } | |
105 | } else { | |
023fb90b LP |
106 | f->escape_timestamp = 0; |
107 | f->escape_counter = 0; | |
04d39279 LP |
108 | } |
109 | } | |
110 | ||
111 | return false; | |
112 | } | |
113 | ||
ae3dde80 LP |
114 | static bool ignore_vhangup(PTYForward *f) { |
115 | assert(f); | |
116 | ||
117 | if (f->flags & PTY_FORWARD_IGNORE_VHANGUP) | |
118 | return true; | |
119 | ||
120 | if ((f->flags & PTY_FORWARD_IGNORE_INITIAL_VHANGUP) && !f->read_from_master) | |
121 | return true; | |
122 | ||
123 | return false; | |
124 | } | |
125 | ||
023fb90b LP |
126 | static int shovel(PTYForward *f) { |
127 | ssize_t k; | |
4ba93280 | 128 | |
023fb90b | 129 | assert(f); |
4ba93280 | 130 | |
023fb90b LP |
131 | while ((f->stdin_readable && f->in_buffer_full <= 0) || |
132 | (f->master_writable && f->in_buffer_full > 0) || | |
133 | (f->master_readable && f->out_buffer_full <= 0) || | |
134 | (f->stdout_writable && f->out_buffer_full > 0)) { | |
4ba93280 | 135 | |
023fb90b | 136 | if (f->stdin_readable && f->in_buffer_full < LINE_MAX) { |
4ba93280 | 137 | |
023fb90b LP |
138 | k = read(STDIN_FILENO, f->in_buffer + f->in_buffer_full, LINE_MAX - f->in_buffer_full); |
139 | if (k < 0) { | |
4ba93280 | 140 | |
023fb90b LP |
141 | if (errno == EAGAIN) |
142 | f->stdin_readable = false; | |
143 | else if (errno == EIO || errno == EPIPE || errno == ECONNRESET) { | |
144 | f->stdin_readable = false; | |
145 | f->stdin_hangup = true; | |
4ba93280 | 146 | |
023fb90b LP |
147 | f->stdin_event_source = sd_event_source_unref(f->stdin_event_source); |
148 | } else { | |
56f64d95 | 149 | log_error_errno(errno, "read(): %m"); |
023fb90b LP |
150 | return sd_event_exit(f->event, EXIT_FAILURE); |
151 | } | |
152 | } else if (k == 0) { | |
153 | /* EOF on stdin */ | |
154 | f->stdin_readable = false; | |
155 | f->stdin_hangup = true; | |
156 | ||
157 | f->stdin_event_source = sd_event_source_unref(f->stdin_event_source); | |
158 | } else { | |
159 | /* Check if ^] has been | |
160 | * pressed three times within | |
161 | * one second. If we get this | |
162 | * we quite immediately. */ | |
163 | if (look_for_escape(f, f->in_buffer + f->in_buffer_full, k)) | |
164 | return sd_event_exit(f->event, EXIT_FAILURE); | |
165 | ||
166 | f->in_buffer_full += (size_t) k; | |
167 | } | |
4ba93280 LP |
168 | } |
169 | ||
023fb90b | 170 | if (f->master_writable && f->in_buffer_full > 0) { |
4ba93280 | 171 | |
023fb90b LP |
172 | k = write(f->master, f->in_buffer, f->in_buffer_full); |
173 | if (k < 0) { | |
4ba93280 | 174 | |
023fb90b LP |
175 | if (errno == EAGAIN || errno == EIO) |
176 | f->master_writable = false; | |
177 | else if (errno == EPIPE || errno == ECONNRESET) { | |
178 | f->master_writable = f->master_readable = false; | |
179 | f->master_hangup = true; | |
4ba93280 | 180 | |
023fb90b LP |
181 | f->master_event_source = sd_event_source_unref(f->master_event_source); |
182 | } else { | |
56f64d95 | 183 | log_error_errno(errno, "write(): %m"); |
023fb90b LP |
184 | return sd_event_exit(f->event, EXIT_FAILURE); |
185 | } | |
186 | } else { | |
187 | assert(f->in_buffer_full >= (size_t) k); | |
188 | memmove(f->in_buffer, f->in_buffer + k, f->in_buffer_full - k); | |
189 | f->in_buffer_full -= k; | |
190 | } | |
4ba93280 LP |
191 | } |
192 | ||
023fb90b | 193 | if (f->master_readable && f->out_buffer_full < LINE_MAX) { |
4ba93280 | 194 | |
023fb90b LP |
195 | k = read(f->master, f->out_buffer + f->out_buffer_full, LINE_MAX - f->out_buffer_full); |
196 | if (k < 0) { | |
4ba93280 | 197 | |
da054c37 LP |
198 | /* Note that EIO on the master device |
199 | * might be caused by vhangup() or | |
200 | * temporary closing of everything on | |
201 | * the other side, we treat it like | |
202 | * EAGAIN here and try again, unless | |
203 | * ignore_vhangup is off. */ | |
4ba93280 | 204 | |
ae3dde80 | 205 | if (errno == EAGAIN || (errno == EIO && ignore_vhangup(f))) |
023fb90b | 206 | f->master_readable = false; |
da054c37 | 207 | else if (errno == EPIPE || errno == ECONNRESET || errno == EIO) { |
023fb90b LP |
208 | f->master_readable = f->master_writable = false; |
209 | f->master_hangup = true; | |
4ba93280 | 210 | |
023fb90b | 211 | f->master_event_source = sd_event_source_unref(f->master_event_source); |
04d39279 | 212 | } else { |
56f64d95 | 213 | log_error_errno(errno, "read(): %m"); |
023fb90b | 214 | return sd_event_exit(f->event, EXIT_FAILURE); |
04d39279 | 215 | } |
ae3dde80 LP |
216 | } else { |
217 | f->read_from_master = true; | |
023fb90b | 218 | f->out_buffer_full += (size_t) k; |
ae3dde80 | 219 | } |
023fb90b | 220 | } |
4ba93280 | 221 | |
023fb90b | 222 | if (f->stdout_writable && f->out_buffer_full > 0) { |
4ba93280 | 223 | |
023fb90b LP |
224 | k = write(STDOUT_FILENO, f->out_buffer, f->out_buffer_full); |
225 | if (k < 0) { | |
4ba93280 | 226 | |
023fb90b LP |
227 | if (errno == EAGAIN) |
228 | f->stdout_writable = false; | |
229 | else if (errno == EIO || errno == EPIPE || errno == ECONNRESET) { | |
230 | f->stdout_writable = false; | |
231 | f->stdout_hangup = true; | |
232 | f->stdout_event_source = sd_event_source_unref(f->stdout_event_source); | |
4ba93280 | 233 | } else { |
56f64d95 | 234 | log_error_errno(errno, "write(): %m"); |
023fb90b | 235 | return sd_event_exit(f->event, EXIT_FAILURE); |
4ba93280 | 236 | } |
4ba93280 | 237 | |
023fb90b | 238 | } else { |
9b15b784 LP |
239 | |
240 | if (k > 0) { | |
241 | f->last_char = f->out_buffer[k-1]; | |
242 | f->last_char_set = true; | |
243 | } | |
244 | ||
023fb90b LP |
245 | assert(f->out_buffer_full >= (size_t) k); |
246 | memmove(f->out_buffer, f->out_buffer + k, f->out_buffer_full - k); | |
247 | f->out_buffer_full -= k; | |
4ba93280 | 248 | } |
023fb90b LP |
249 | } |
250 | } | |
251 | ||
252 | if (f->stdin_hangup || f->stdout_hangup || f->master_hangup) { | |
253 | /* Exit the loop if any side hung up and if there's | |
254 | * nothing more to write or nothing we could write. */ | |
4ba93280 | 255 | |
023fb90b LP |
256 | if ((f->out_buffer_full <= 0 || f->stdout_hangup) && |
257 | (f->in_buffer_full <= 0 || f->master_hangup)) | |
258 | return sd_event_exit(f->event, EXIT_SUCCESS); | |
259 | } | |
4ba93280 | 260 | |
023fb90b LP |
261 | return 0; |
262 | } | |
4ba93280 | 263 | |
023fb90b LP |
264 | static int on_master_event(sd_event_source *e, int fd, uint32_t revents, void *userdata) { |
265 | PTYForward *f = userdata; | |
4ba93280 | 266 | |
023fb90b LP |
267 | assert(f); |
268 | assert(e); | |
269 | assert(e == f->master_event_source); | |
270 | assert(fd >= 0); | |
271 | assert(fd == f->master); | |
04d39279 | 272 | |
023fb90b LP |
273 | if (revents & (EPOLLIN|EPOLLHUP)) |
274 | f->master_readable = true; | |
04d39279 | 275 | |
023fb90b LP |
276 | if (revents & (EPOLLOUT|EPOLLHUP)) |
277 | f->master_writable = true; | |
04d39279 | 278 | |
023fb90b LP |
279 | return shovel(f); |
280 | } | |
04d39279 | 281 | |
023fb90b LP |
282 | static int on_stdin_event(sd_event_source *e, int fd, uint32_t revents, void *userdata) { |
283 | PTYForward *f = userdata; | |
04d39279 | 284 | |
023fb90b LP |
285 | assert(f); |
286 | assert(e); | |
287 | assert(e == f->stdin_event_source); | |
288 | assert(fd >= 0); | |
289 | assert(fd == STDIN_FILENO); | |
04d39279 | 290 | |
023fb90b LP |
291 | if (revents & (EPOLLIN|EPOLLHUP)) |
292 | f->stdin_readable = true; | |
04d39279 | 293 | |
023fb90b LP |
294 | return shovel(f); |
295 | } | |
04d39279 | 296 | |
023fb90b LP |
297 | static int on_stdout_event(sd_event_source *e, int fd, uint32_t revents, void *userdata) { |
298 | PTYForward *f = userdata; | |
04d39279 | 299 | |
023fb90b LP |
300 | assert(f); |
301 | assert(e); | |
302 | assert(e == f->stdout_event_source); | |
303 | assert(fd >= 0); | |
304 | assert(fd == STDOUT_FILENO); | |
04d39279 | 305 | |
023fb90b LP |
306 | if (revents & (EPOLLOUT|EPOLLHUP)) |
307 | f->stdout_writable = true; | |
04d39279 | 308 | |
023fb90b LP |
309 | return shovel(f); |
310 | } | |
04d39279 | 311 | |
023fb90b LP |
312 | static int on_sigwinch_event(sd_event_source *e, const struct signalfd_siginfo *si, void *userdata) { |
313 | PTYForward *f = userdata; | |
314 | struct winsize ws; | |
04d39279 | 315 | |
023fb90b LP |
316 | assert(f); |
317 | assert(e); | |
318 | assert(e == f->sigwinch_event_source); | |
319 | ||
320 | /* The window size changed, let's forward that. */ | |
321 | if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) >= 0) | |
679bc6cb | 322 | (void) ioctl(f->master, TIOCSWINSZ, &ws); |
023fb90b LP |
323 | |
324 | return 0; | |
4ba93280 | 325 | } |
04d39279 | 326 | |
9c857b9d LP |
327 | int pty_forward_new( |
328 | sd_event *event, | |
329 | int master, | |
ae3dde80 | 330 | PTYForwardFlags flags, |
9c857b9d LP |
331 | PTYForward **ret) { |
332 | ||
023fb90b | 333 | _cleanup_(pty_forward_freep) PTYForward *f = NULL; |
04d39279 LP |
334 | struct winsize ws; |
335 | int r; | |
336 | ||
023fb90b LP |
337 | f = new0(PTYForward, 1); |
338 | if (!f) | |
339 | return -ENOMEM; | |
340 | ||
ae3dde80 | 341 | f->flags = flags; |
9b15b784 | 342 | |
023fb90b LP |
343 | if (event) |
344 | f->event = sd_event_ref(event); | |
345 | else { | |
346 | r = sd_event_default(&f->event); | |
347 | if (r < 0) | |
348 | return r; | |
349 | } | |
350 | ||
ae3dde80 | 351 | if (!(flags & PTY_FORWARD_READ_ONLY)) { |
9c857b9d LP |
352 | r = fd_nonblock(STDIN_FILENO, true); |
353 | if (r < 0) | |
354 | return r; | |
023fb90b | 355 | |
9c857b9d LP |
356 | r = fd_nonblock(STDOUT_FILENO, true); |
357 | if (r < 0) | |
358 | return r; | |
359 | } | |
023fb90b LP |
360 | |
361 | r = fd_nonblock(master, true); | |
362 | if (r < 0) | |
363 | return r; | |
364 | ||
365 | f->master = master; | |
366 | ||
eaf73b06 | 367 | if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) >= 0) |
dc751688 | 368 | (void) ioctl(master, TIOCSWINSZ, &ws); |
04d39279 | 369 | |
ae3dde80 | 370 | if (!(flags & PTY_FORWARD_READ_ONLY)) { |
9c857b9d LP |
371 | if (tcgetattr(STDIN_FILENO, &f->saved_stdin_attr) >= 0) { |
372 | struct termios raw_stdin_attr; | |
023fb90b | 373 | |
9c857b9d | 374 | f->saved_stdin = true; |
90d14d20 | 375 | |
9c857b9d LP |
376 | raw_stdin_attr = f->saved_stdin_attr; |
377 | cfmakeraw(&raw_stdin_attr); | |
378 | raw_stdin_attr.c_oflag = f->saved_stdin_attr.c_oflag; | |
379 | tcsetattr(STDIN_FILENO, TCSANOW, &raw_stdin_attr); | |
380 | } | |
023fb90b | 381 | |
9c857b9d LP |
382 | if (tcgetattr(STDOUT_FILENO, &f->saved_stdout_attr) >= 0) { |
383 | struct termios raw_stdout_attr; | |
023fb90b | 384 | |
9c857b9d | 385 | f->saved_stdout = true; |
04d39279 | 386 | |
9c857b9d LP |
387 | raw_stdout_attr = f->saved_stdout_attr; |
388 | cfmakeraw(&raw_stdout_attr); | |
389 | raw_stdout_attr.c_iflag = f->saved_stdout_attr.c_iflag; | |
390 | raw_stdout_attr.c_lflag = f->saved_stdout_attr.c_lflag; | |
391 | tcsetattr(STDOUT_FILENO, TCSANOW, &raw_stdout_attr); | |
392 | } | |
04d39279 | 393 | |
9c857b9d LP |
394 | r = sd_event_add_io(f->event, &f->stdin_event_source, STDIN_FILENO, EPOLLIN|EPOLLET, on_stdin_event, f); |
395 | if (r < 0 && r != -EPERM) | |
396 | return r; | |
397 | } | |
023fb90b LP |
398 | |
399 | r = sd_event_add_io(f->event, &f->stdout_event_source, STDOUT_FILENO, EPOLLOUT|EPOLLET, on_stdout_event, f); | |
400 | if (r == -EPERM) | |
401 | /* stdout without epoll support. Likely redirected to regular file. */ | |
402 | f->stdout_writable = true; | |
403 | else if (r < 0) | |
404 | return r; | |
405 | ||
9c857b9d LP |
406 | r = sd_event_add_io(f->event, &f->master_event_source, master, EPOLLIN|EPOLLOUT|EPOLLET, on_master_event, f); |
407 | if (r < 0) | |
408 | return r; | |
409 | ||
023fb90b | 410 | r = sd_event_add_signal(f->event, &f->sigwinch_event_source, SIGWINCH, on_sigwinch_event, f); |
679bc6cb LP |
411 | if (r < 0) |
412 | return r; | |
023fb90b LP |
413 | |
414 | *ret = f; | |
415 | f = NULL; | |
416 | ||
417 | return 0; | |
418 | } | |
419 | ||
420 | PTYForward *pty_forward_free(PTYForward *f) { | |
421 | ||
422 | if (f) { | |
423 | sd_event_source_unref(f->stdin_event_source); | |
424 | sd_event_source_unref(f->stdout_event_source); | |
425 | sd_event_source_unref(f->master_event_source); | |
3c747da3 | 426 | sd_event_source_unref(f->sigwinch_event_source); |
023fb90b LP |
427 | sd_event_unref(f->event); |
428 | ||
429 | if (f->saved_stdout) | |
430 | tcsetattr(STDOUT_FILENO, TCSANOW, &f->saved_stdout_attr); | |
431 | if (f->saved_stdin) | |
432 | tcsetattr(STDIN_FILENO, TCSANOW, &f->saved_stdin_attr); | |
433 | ||
434 | free(f); | |
435 | } | |
04d39279 | 436 | |
d60473c7 LP |
437 | /* STDIN/STDOUT should not be nonblocking normally, so let's |
438 | * unconditionally reset it */ | |
439 | fd_nonblock(STDIN_FILENO, false); | |
440 | fd_nonblock(STDOUT_FILENO, false); | |
441 | ||
023fb90b | 442 | return NULL; |
04d39279 | 443 | } |
9b15b784 | 444 | |
0ec5543c | 445 | int pty_forward_get_last_char(PTYForward *f, char *ch) { |
9b15b784 LP |
446 | assert(f); |
447 | assert(ch); | |
448 | ||
449 | if (!f->last_char_set) | |
450 | return -ENXIO; | |
451 | ||
452 | *ch = f->last_char; | |
453 | return 0; | |
454 | } | |
0ec5543c | 455 | |
ae3dde80 | 456 | int pty_forward_set_ignore_vhangup(PTYForward *f, bool b) { |
0ec5543c LP |
457 | int r; |
458 | ||
459 | assert(f); | |
460 | ||
ae3dde80 | 461 | if (!!(f->flags & PTY_FORWARD_IGNORE_VHANGUP) == b) |
0ec5543c LP |
462 | return 0; |
463 | ||
ae3dde80 LP |
464 | if (b) |
465 | f->flags |= PTY_FORWARD_IGNORE_VHANGUP; | |
466 | else | |
467 | f->flags &= ~PTY_FORWARD_IGNORE_VHANGUP; | |
468 | ||
469 | if (!ignore_vhangup(f)) { | |
0ec5543c | 470 | |
da054c37 LP |
471 | /* We shall now react to vhangup()s? Let's check |
472 | * immediately if we might be in one */ | |
0ec5543c LP |
473 | |
474 | f->master_readable = true; | |
475 | r = shovel(f); | |
476 | if (r < 0) | |
477 | return r; | |
478 | } | |
479 | ||
480 | return 0; | |
481 | } | |
482 | ||
da054c37 | 483 | int pty_forward_get_ignore_vhangup(PTYForward *f) { |
0ec5543c LP |
484 | assert(f); |
485 | ||
ae3dde80 | 486 | return !!(f->flags & PTY_FORWARD_IGNORE_VHANGUP); |
0ec5543c | 487 | } |