2 This file is part of systemd.
4 Copyright 2010-2013 Lennart Poettering
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.
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.
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/>.
27 #include <sys/epoll.h>
28 #include <sys/ioctl.h>
35 #include "alloc-util.h"
40 #include "time-util.h"
47 PTYForwardFlags flags
;
49 sd_event_source
*stdin_event_source
;
50 sd_event_source
*stdout_event_source
;
51 sd_event_source
*master_event_source
;
53 sd_event_source
*sigwinch_event_source
;
55 struct termios saved_stdin_attr
;
56 struct termios saved_stdout_attr
;
61 bool stdin_readable
:1;
63 bool stdout_writable
:1;
65 bool master_readable
:1;
66 bool master_writable
:1;
69 bool read_from_master
:1;
74 char in_buffer
[LINE_MAX
], out_buffer
[LINE_MAX
];
75 size_t in_buffer_full
, out_buffer_full
;
77 usec_t escape_timestamp
;
78 unsigned escape_counter
;
81 #define ESCAPE_USEC (1*USEC_PER_SEC)
83 static bool look_for_escape(PTYForward
*f
, const char *buffer
, size_t n
) {
90 for (p
= buffer
; p
< buffer
+ n
; p
++) {
94 usec_t nw
= now(CLOCK_MONOTONIC
);
96 if (f
->escape_counter
== 0 || nw
> f
->escape_timestamp
+ ESCAPE_USEC
) {
97 f
->escape_timestamp
= nw
;
98 f
->escape_counter
= 1;
100 (f
->escape_counter
)++;
102 if (f
->escape_counter
>= 3)
106 f
->escape_timestamp
= 0;
107 f
->escape_counter
= 0;
114 static bool ignore_vhangup(PTYForward
*f
) {
117 if (f
->flags
& PTY_FORWARD_IGNORE_VHANGUP
)
120 if ((f
->flags
& PTY_FORWARD_IGNORE_INITIAL_VHANGUP
) && !f
->read_from_master
)
126 static int shovel(PTYForward
*f
) {
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)) {
136 if (f
->stdin_readable
&& f
->in_buffer_full
< LINE_MAX
) {
138 k
= read(STDIN_FILENO
, f
->in_buffer
+ f
->in_buffer_full
, LINE_MAX
- f
->in_buffer_full
);
142 f
->stdin_readable
= false;
143 else if (errno
== EIO
|| errno
== EPIPE
|| errno
== ECONNRESET
) {
144 f
->stdin_readable
= false;
145 f
->stdin_hangup
= true;
147 f
->stdin_event_source
= sd_event_source_unref(f
->stdin_event_source
);
149 log_error_errno(errno
, "read(): %m");
150 return sd_event_exit(f
->event
, EXIT_FAILURE
);
154 f
->stdin_readable
= false;
155 f
->stdin_hangup
= true;
157 f
->stdin_event_source
= sd_event_source_unref(f
->stdin_event_source
);
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
);
166 f
->in_buffer_full
+= (size_t) k
;
170 if (f
->master_writable
&& f
->in_buffer_full
> 0) {
172 k
= write(f
->master
, f
->in_buffer
, f
->in_buffer_full
);
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;
181 f
->master_event_source
= sd_event_source_unref(f
->master_event_source
);
183 log_error_errno(errno
, "write(): %m");
184 return sd_event_exit(f
->event
, EXIT_FAILURE
);
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
;
193 if (f
->master_readable
&& f
->out_buffer_full
< LINE_MAX
) {
195 k
= read(f
->master
, f
->out_buffer
+ f
->out_buffer_full
, LINE_MAX
- f
->out_buffer_full
);
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. */
205 if (errno
== EAGAIN
|| (errno
== EIO
&& ignore_vhangup(f
)))
206 f
->master_readable
= false;
207 else if (errno
== EPIPE
|| errno
== ECONNRESET
|| errno
== EIO
) {
208 f
->master_readable
= f
->master_writable
= false;
209 f
->master_hangup
= true;
211 f
->master_event_source
= sd_event_source_unref(f
->master_event_source
);
213 log_error_errno(errno
, "read(): %m");
214 return sd_event_exit(f
->event
, EXIT_FAILURE
);
217 f
->read_from_master
= true;
218 f
->out_buffer_full
+= (size_t) k
;
222 if (f
->stdout_writable
&& f
->out_buffer_full
> 0) {
224 k
= write(STDOUT_FILENO
, f
->out_buffer
, f
->out_buffer_full
);
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
);
234 log_error_errno(errno
, "write(): %m");
235 return sd_event_exit(f
->event
, EXIT_FAILURE
);
241 f
->last_char
= f
->out_buffer
[k
-1];
242 f
->last_char_set
= true;
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
;
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. */
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
);
264 static int on_master_event(sd_event_source
*e
, int fd
, uint32_t revents
, void *userdata
) {
265 PTYForward
*f
= userdata
;
269 assert(e
== f
->master_event_source
);
271 assert(fd
== f
->master
);
273 if (revents
& (EPOLLIN
|EPOLLHUP
))
274 f
->master_readable
= true;
276 if (revents
& (EPOLLOUT
|EPOLLHUP
))
277 f
->master_writable
= true;
282 static int on_stdin_event(sd_event_source
*e
, int fd
, uint32_t revents
, void *userdata
) {
283 PTYForward
*f
= userdata
;
287 assert(e
== f
->stdin_event_source
);
289 assert(fd
== STDIN_FILENO
);
291 if (revents
& (EPOLLIN
|EPOLLHUP
))
292 f
->stdin_readable
= true;
297 static int on_stdout_event(sd_event_source
*e
, int fd
, uint32_t revents
, void *userdata
) {
298 PTYForward
*f
= userdata
;
302 assert(e
== f
->stdout_event_source
);
304 assert(fd
== STDOUT_FILENO
);
306 if (revents
& (EPOLLOUT
|EPOLLHUP
))
307 f
->stdout_writable
= true;
312 static int on_sigwinch_event(sd_event_source
*e
, const struct signalfd_siginfo
*si
, void *userdata
) {
313 PTYForward
*f
= userdata
;
318 assert(e
== f
->sigwinch_event_source
);
320 /* The window size changed, let's forward that. */
321 if (ioctl(STDOUT_FILENO
, TIOCGWINSZ
, &ws
) >= 0)
322 (void) ioctl(f
->master
, TIOCSWINSZ
, &ws
);
330 PTYForwardFlags flags
,
333 _cleanup_(pty_forward_freep
) PTYForward
*f
= NULL
;
337 f
= new0(PTYForward
, 1);
344 f
->event
= sd_event_ref(event
);
346 r
= sd_event_default(&f
->event
);
351 if (!(flags
& PTY_FORWARD_READ_ONLY
)) {
352 r
= fd_nonblock(STDIN_FILENO
, true);
356 r
= fd_nonblock(STDOUT_FILENO
, true);
361 r
= fd_nonblock(master
, true);
367 if (ioctl(STDOUT_FILENO
, TIOCGWINSZ
, &ws
) >= 0)
368 (void) ioctl(master
, TIOCSWINSZ
, &ws
);
370 if (!(flags
& PTY_FORWARD_READ_ONLY
)) {
371 if (tcgetattr(STDIN_FILENO
, &f
->saved_stdin_attr
) >= 0) {
372 struct termios raw_stdin_attr
;
374 f
->saved_stdin
= true;
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
);
382 if (tcgetattr(STDOUT_FILENO
, &f
->saved_stdout_attr
) >= 0) {
383 struct termios raw_stdout_attr
;
385 f
->saved_stdout
= true;
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
);
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
)
399 r
= sd_event_add_io(f
->event
, &f
->stdout_event_source
, STDOUT_FILENO
, EPOLLOUT
|EPOLLET
, on_stdout_event
, f
);
401 /* stdout without epoll support. Likely redirected to regular file. */
402 f
->stdout_writable
= true;
406 r
= sd_event_add_io(f
->event
, &f
->master_event_source
, master
, EPOLLIN
|EPOLLOUT
|EPOLLET
, on_master_event
, f
);
410 r
= sd_event_add_signal(f
->event
, &f
->sigwinch_event_source
, SIGWINCH
, on_sigwinch_event
, f
);
420 PTYForward
*pty_forward_free(PTYForward
*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
);
426 sd_event_source_unref(f
->sigwinch_event_source
);
427 sd_event_unref(f
->event
);
430 tcsetattr(STDOUT_FILENO
, TCSANOW
, &f
->saved_stdout_attr
);
432 tcsetattr(STDIN_FILENO
, TCSANOW
, &f
->saved_stdin_attr
);
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);
445 int pty_forward_get_last_char(PTYForward
*f
, char *ch
) {
449 if (!f
->last_char_set
)
456 int pty_forward_set_ignore_vhangup(PTYForward
*f
, bool b
) {
461 if (!!(f
->flags
& PTY_FORWARD_IGNORE_VHANGUP
) == b
)
465 f
->flags
|= PTY_FORWARD_IGNORE_VHANGUP
;
467 f
->flags
&= ~PTY_FORWARD_IGNORE_VHANGUP
;
469 if (!ignore_vhangup(f
)) {
471 /* We shall now react to vhangup()s? Let's check
472 * immediately if we might be in one */
474 f
->master_readable
= true;
483 int pty_forward_get_ignore_vhangup(PTYForward
*f
) {
486 return !!(f
->flags
& PTY_FORWARD_IGNORE_VHANGUP
);