1 /* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
2 *
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to
5 * deal in the Software without restriction, including without limitation the
6 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
7 * sell copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
9 *
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
19 * IN THE SOFTWARE.
20 */
21
22 #include "uv.h"
23 #include "internal.h"
24
25 #include <stdatomic.h>
26 #include <stdlib.h>
27 #include <assert.h>
28 #include <unistd.h>
29 #include <termios.h>
30 #include <errno.h>
31 #include <sys/ioctl.h>
32
33 #if defined(__MVS__) && !defined(IMAXBEL)
34 #define IMAXBEL 0
35 #endif
36
37 #if defined(__PASE__)
38 /* On IBM i PASE, for better compatibility with running interactive programs in
39 * a 5250 environment, isatty() will return true for the stdin/stdout/stderr
40 * streams created by QSH/QP2TERM.
41 *
42 * For more, see docs on PASE_STDIO_ISATTY in
43 * https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_74/apis/pase_environ.htm
44 *
45 * This behavior causes problems for Node as it expects that if isatty() returns
46 * true that TTY ioctls will be supported by that fd (which is not an
47 * unreasonable expectation) and when they don't it crashes with assertion
48 * errors.
49 *
50 * Here, we create our own version of isatty() that uses ioctl() to identify
51 * whether the fd is *really* a TTY or not.
52 */
isreallyatty(int file)53 static int isreallyatty(int file) {
54 int rc;
55
56 rc = !ioctl(file, TXISATTY + 0x81, NULL);
57 if (!rc && errno != EBADF)
58 errno = ENOTTY;
59
60 return rc;
61 }
62 #define isatty(fd) isreallyatty(fd)
63 #endif
64
65 static int orig_termios_fd = -1;
66 static struct termios orig_termios;
67 static _Atomic int termios_spinlock;
68
uv__tcsetattr(int fd,int how,const struct termios * term)69 int uv__tcsetattr(int fd, int how, const struct termios *term) {
70 int rc;
71
72 do
73 rc = tcsetattr(fd, how, term);
74 while (rc == -1 && errno == EINTR);
75
76 if (rc == -1)
77 return UV__ERR(errno);
78
79 return 0;
80 }
81
uv__tty_is_slave(const int fd)82 static int uv__tty_is_slave(const int fd) {
83 int result;
84 #if defined(__linux__) || defined(__FreeBSD__)
85 int dummy;
86
87 result = ioctl(fd, TIOCGPTN, &dummy) != 0;
88 #elif defined(__APPLE__)
89 char dummy[256];
90
91 result = ioctl(fd, TIOCPTYGNAME, &dummy) != 0;
92 #elif defined(__NetBSD__)
93 /*
94 * NetBSD as an extension returns with ptsname(3) and ptsname_r(3) the slave
95 * device name for both descriptors, the master one and slave one.
96 *
97 * Implement function to compare major device number with pts devices.
98 *
99 * The major numbers are machine-dependent, on NetBSD/amd64 they are
100 * respectively:
101 * - master tty: ptc - major 6
102 * - slave tty: pts - major 5
103 */
104
105 struct stat sb;
106 /* Lookup device's major for the pts driver and cache it. */
107 static devmajor_t pts = NODEVMAJOR;
108
109 if (pts == NODEVMAJOR) {
110 pts = getdevmajor("pts", S_IFCHR);
111 if (pts == NODEVMAJOR)
112 abort();
113 }
114
115 /* Lookup stat structure behind the file descriptor. */
116 if (uv__fstat(fd, &sb) != 0)
117 abort();
118
119 /* Assert character device. */
120 if (!S_ISCHR(sb.st_mode))
121 abort();
122
123 /* Assert valid major. */
124 if (major(sb.st_rdev) == NODEVMAJOR)
125 abort();
126
127 result = (pts == major(sb.st_rdev));
128 #else
129 /* Fallback to ptsname
130 */
131 result = ptsname(fd) == NULL;
132 #endif
133 return result;
134 }
135
uv_tty_init(uv_loop_t * loop,uv_tty_t * tty,int fd,int unused)136 int uv_tty_init(uv_loop_t* loop, uv_tty_t* tty, int fd, int unused) {
137 uv_handle_type type;
138 int flags;
139 int newfd;
140 int r;
141 int saved_flags;
142 int mode;
143 char path[256];
144 (void)unused; /* deprecated parameter is no longer needed */
145
146 /* File descriptors that refer to files cannot be monitored with epoll.
147 * That restriction also applies to character devices like /dev/random
148 * (but obviously not /dev/tty.)
149 */
150 type = uv_guess_handle(fd);
151 if (type == UV_FILE || type == UV_UNKNOWN_HANDLE)
152 return UV_EINVAL;
153
154 flags = 0;
155 newfd = -1;
156
157 /* Save the fd flags in case we need to restore them due to an error. */
158 do
159 saved_flags = fcntl(fd, F_GETFL);
160 while (saved_flags == -1 && errno == EINTR);
161
162 if (saved_flags == -1)
163 return UV__ERR(errno);
164 mode = saved_flags & O_ACCMODE;
165
166 /* Reopen the file descriptor when it refers to a tty. This lets us put the
167 * tty in non-blocking mode without affecting other processes that share it
168 * with us.
169 *
170 * Example: `node | cat` - if we put our fd 0 in non-blocking mode, it also
171 * affects fd 1 of `cat` because both file descriptors refer to the same
172 * struct file in the kernel. When we reopen our fd 0, it points to a
173 * different struct file, hence changing its properties doesn't affect
174 * other processes.
175 */
176 if (type == UV_TTY) {
177 /* Reopening a pty in master mode won't work either because the reopened
178 * pty will be in slave mode (*BSD) or reopening will allocate a new
179 * master/slave pair (Linux). Therefore check if the fd points to a
180 * slave device.
181 */
182 if (uv__tty_is_slave(fd) && ttyname_r(fd, path, sizeof(path)) == 0)
183 r = uv__open_cloexec(path, mode | O_NOCTTY);
184 else
185 r = -1;
186
187 if (r < 0) {
188 /* fallback to using blocking writes */
189 if (mode != O_RDONLY)
190 flags |= UV_HANDLE_BLOCKING_WRITES;
191 goto skip;
192 }
193
194 newfd = r;
195
196 r = uv__dup2_cloexec(newfd, fd);
197 if (r < 0 && r != UV_EINVAL) {
198 /* EINVAL means newfd == fd which could conceivably happen if another
199 * thread called close(fd) between our calls to isatty() and open().
200 * That's a rather unlikely event but let's handle it anyway.
201 */
202 uv__close(newfd);
203 return r;
204 }
205
206 fd = newfd;
207 }
208
209 skip:
210 uv__stream_init(loop, (uv_stream_t*) tty, UV_TTY);
211
212 /* If anything fails beyond this point we need to remove the handle from
213 * the handle queue, since it was added by uv__handle_init in uv_stream_init.
214 */
215
216 if (!(flags & UV_HANDLE_BLOCKING_WRITES))
217 uv__nonblock(fd, 1);
218
219 #if defined(__APPLE__)
220 r = uv__stream_try_select((uv_stream_t*) tty, &fd);
221 if (r) {
222 int rc = r;
223 if (newfd != -1)
224 uv__close(newfd);
225 uv__queue_remove(&tty->handle_queue);
226 do
227 r = fcntl(fd, F_SETFL, saved_flags);
228 while (r == -1 && errno == EINTR);
229 return rc;
230 }
231 #endif
232
233 if (mode != O_WRONLY)
234 flags |= UV_HANDLE_READABLE;
235 if (mode != O_RDONLY)
236 flags |= UV_HANDLE_WRITABLE;
237
238 uv__stream_open((uv_stream_t*) tty, fd, flags);
239 tty->mode = UV_TTY_MODE_NORMAL;
240
241 return 0;
242 }
243
uv__tty_make_raw(struct termios * tio)244 static void uv__tty_make_raw(struct termios* tio) {
245 assert(tio != NULL);
246
247 #if defined __sun || defined __MVS__
248 /*
249 * This implementation of cfmakeraw for Solaris and derivatives is taken from
250 * http://www.perkin.org.uk/posts/solaris-portability-cfmakeraw.html.
251 */
252 tio->c_iflag &= ~(IMAXBEL | IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR |
253 IGNCR | ICRNL | IXON);
254 tio->c_oflag &= ~OPOST;
255 tio->c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
256 tio->c_cflag &= ~(CSIZE | PARENB);
257 tio->c_cflag |= CS8;
258
259 /*
260 * By default, most software expects a pending read to block until at
261 * least one byte becomes available. As per termio(7I), this requires
262 * setting the MIN and TIME parameters appropriately.
263 *
264 * As a somewhat unfortunate artifact of history, the MIN and TIME slots
265 * in the control character array overlap with the EOF and EOL slots used
266 * for canonical mode processing. Because the EOF character needs to be
267 * the ASCII EOT value (aka Control-D), it has the byte value 4. When
268 * switching to raw mode, this is interpreted as a MIN value of 4; i.e.,
269 * reads will block until at least four bytes have been input.
270 *
271 * Other platforms with a distinct MIN slot like Linux and FreeBSD appear
272 * to default to a MIN value of 1, so we'll force that value here:
273 */
274 tio->c_cc[VMIN] = 1;
275 tio->c_cc[VTIME] = 0;
276 #else
277 cfmakeraw(tio);
278 #endif /* #ifdef __sun */
279 }
280
uv_tty_set_mode(uv_tty_t * tty,uv_tty_mode_t mode)281 int uv_tty_set_mode(uv_tty_t* tty, uv_tty_mode_t mode) {
282 struct termios tmp;
283 int expected;
284 int fd;
285 int rc;
286
287 if (tty->mode == (int) mode)
288 return 0;
289
290 fd = uv__stream_fd(tty);
291 if (tty->mode == UV_TTY_MODE_NORMAL && mode != UV_TTY_MODE_NORMAL) {
292 do
293 rc = tcgetattr(fd, &tty->orig_termios);
294 while (rc == -1 && errno == EINTR);
295
296 if (rc == -1)
297 return UV__ERR(errno);
298
299 /* This is used for uv_tty_reset_mode() */
300 do
301 expected = 0;
302 while (!atomic_compare_exchange_strong(&termios_spinlock, &expected, 1));
303
304 if (orig_termios_fd == -1) {
305 orig_termios = tty->orig_termios;
306 orig_termios_fd = fd;
307 }
308
309 atomic_store(&termios_spinlock, 0);
310 }
311
312 tmp = tty->orig_termios;
313 switch (mode) {
314 case UV_TTY_MODE_NORMAL:
315 break;
316 case UV_TTY_MODE_RAW:
317 tmp.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
318 tmp.c_oflag |= (ONLCR);
319 tmp.c_cflag |= (CS8);
320 tmp.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
321 tmp.c_cc[VMIN] = 1;
322 tmp.c_cc[VTIME] = 0;
323 break;
324 case UV_TTY_MODE_IO:
325 uv__tty_make_raw(&tmp);
326 break;
327 }
328
329 /* Apply changes after draining */
330 rc = uv__tcsetattr(fd, TCSADRAIN, &tmp);
331 if (rc == 0)
332 tty->mode = mode;
333
334 return rc;
335 }
336
337
uv_tty_get_winsize(uv_tty_t * tty,int * width,int * height)338 int uv_tty_get_winsize(uv_tty_t* tty, int* width, int* height) {
339 struct winsize ws;
340 int err;
341
342 do
343 err = ioctl(uv__stream_fd(tty), TIOCGWINSZ, &ws);
344 while (err == -1 && errno == EINTR);
345
346 if (err == -1)
347 return UV__ERR(errno);
348
349 *width = ws.ws_col;
350 *height = ws.ws_row;
351
352 return 0;
353 }
354
355
uv_guess_handle(uv_file file)356 uv_handle_type uv_guess_handle(uv_file file) {
357 struct sockaddr_storage ss;
358 struct stat s;
359 socklen_t len;
360 int type;
361
362 if (file < 0)
363 return UV_UNKNOWN_HANDLE;
364
365 if (isatty(file))
366 return UV_TTY;
367
368 if (uv__fstat(file, &s)) {
369 #if defined(__PASE__)
370 /* On ibmi receiving RST from TCP instead of FIN immediately puts fd into
371 * an error state. fstat will return EINVAL, getsockname will also return
372 * EINVAL, even if sockaddr_storage is valid. (If file does not refer to a
373 * socket, ENOTSOCK is returned instead.)
374 * In such cases, we will permit the user to open the connection as uv_tcp
375 * still, so that the user can get immediately notified of the error in
376 * their read callback and close this fd.
377 */
378 len = sizeof(ss);
379 if (getsockname(file, (struct sockaddr*) &ss, &len)) {
380 if (errno == EINVAL)
381 return UV_TCP;
382 }
383 #endif
384 return UV_UNKNOWN_HANDLE;
385 }
386
387 if (S_ISREG(s.st_mode))
388 return UV_FILE;
389
390 if (S_ISCHR(s.st_mode))
391 return UV_FILE; /* XXX UV_NAMED_PIPE? */
392
393 if (S_ISFIFO(s.st_mode))
394 return UV_NAMED_PIPE;
395
396 if (!S_ISSOCK(s.st_mode))
397 return UV_UNKNOWN_HANDLE;
398
399 len = sizeof(ss);
400 if (getsockname(file, (struct sockaddr*) &ss, &len)) {
401 #if defined(_AIX)
402 /* On aix receiving RST from TCP instead of FIN immediately puts fd into
403 * an error state. In such case getsockname will return EINVAL, even if
404 * sockaddr_storage is valid.
405 * In such cases, we will permit the user to open the connection as uv_tcp
406 * still, so that the user can get immediately notified of the error in
407 * their read callback and close this fd.
408 */
409 if (errno == EINVAL) {
410 return UV_TCP;
411 }
412 #endif
413 return UV_UNKNOWN_HANDLE;
414 }
415
416 len = sizeof(type);
417 if (getsockopt(file, SOL_SOCKET, SO_TYPE, &type, &len))
418 return UV_UNKNOWN_HANDLE;
419
420 if (type == SOCK_DGRAM)
421 if (ss.ss_family == AF_INET || ss.ss_family == AF_INET6)
422 return UV_UDP;
423
424 if (type == SOCK_STREAM) {
425 #if defined(_AIX) || defined(__DragonFly__)
426 /* on AIX/DragonFly the getsockname call returns an empty sa structure
427 * for sockets of type AF_UNIX. For all other types it will
428 * return a properly filled in structure.
429 */
430 if (len == 0)
431 return UV_NAMED_PIPE;
432 #endif /* defined(_AIX) || defined(__DragonFly__) */
433
434 if (ss.ss_family == AF_INET || ss.ss_family == AF_INET6)
435 return UV_TCP;
436 if (ss.ss_family == AF_UNIX)
437 return UV_NAMED_PIPE;
438 }
439
440 return UV_UNKNOWN_HANDLE;
441 }
442
443
444 /* This function is async signal-safe, meaning that it's safe to call from
445 * inside a signal handler _unless_ execution was inside uv_tty_set_mode()'s
446 * critical section when the signal was raised.
447 */
uv_tty_reset_mode(void)448 int uv_tty_reset_mode(void) {
449 int saved_errno;
450 int err;
451
452 saved_errno = errno;
453
454 if (atomic_exchange(&termios_spinlock, 1))
455 return UV_EBUSY; /* In uv_tty_set_mode(). */
456
457 err = 0;
458 if (orig_termios_fd != -1)
459 err = uv__tcsetattr(orig_termios_fd, TCSANOW, &orig_termios);
460
461 atomic_store(&termios_spinlock, 0);
462 errno = saved_errno;
463
464 return err;
465 }
466
uv_tty_set_vterm_state(uv_tty_vtermstate_t state)467 void uv_tty_set_vterm_state(uv_tty_vtermstate_t state) {
468 }
469
uv_tty_get_vterm_state(uv_tty_vtermstate_t * state)470 int uv_tty_get_vterm_state(uv_tty_vtermstate_t* state) {
471 return UV_ENOTSUP;
472 }
473
