xref: /haiku/src/apps/terminal/Shell.cpp (revision b55a57da7173b9af0432bd3e148d03f06161d036)
1 /*
2  * Copyright 2007-2009, Haiku, Inc. All rights reserved.
3  * Copyright (c) 2003-4 Kian Duffy <myob@users.sourceforge.net>
4  * Copyright (c) 2004 Daniel Furrer <assimil8or@users.sourceforge.net>
5  * Parts Copyright (C) 1998,99 Kazuho Okui and Takashi Murai.
6  *
7  * Distributed under the terms of the MIT license.
8  *
9  */
10 
11 #include "Shell.h"
12 
13 #include <dirent.h>
14 #include <errno.h>
15 #include <fcntl.h>
16 #include <new>
17 #include <signal.h>
18 #include <string.h>
19 #include <stdlib.h>
20 #include <stddef.h>
21 #include <stdio.h>
22 #include <sys/param.h>
23 #include <sys/stat.h>
24 #include <sys/wait.h>
25 #include <termios.h>
26 #include <time.h>
27 #include <unistd.h>
28 
29 #include <OS.h>
30 
31 #include "TermConst.h"
32 #include "TermParse.h"
33 #include "TerminalBuffer.h"
34 
35 
36 #ifndef CEOF
37 #define CEOF ('D'&037)
38 #endif
39 #ifndef CSUSP
40 #define CSUSP ('Z'&037)
41 #endif
42 #ifndef CQUIT
43 #define CQUIT ('\\'&037)
44 #endif
45 #ifndef CEOL
46 #define CEOL 0
47 #endif
48 #ifndef CSTOP
49 #define CSTOP ('Q'&037)
50 #endif
51 #ifndef CSTART
52 #define CSTART ('S'&037)
53 #endif
54 #ifndef CSWTCH
55 #define CSWTCH 0
56 #endif
57 
58 
59 /*
60  * Set environment variable.
61  */
62 #if defined(HAIKU_TARGET_PLATFORM_BEOS) || \
63 	defined(HAIKU_TARGET_PLATFORM_BONE) || \
64 	defined(HAIKU_TARGET_PLATFORM_LIBBE_TEST)
65 
66 extern char **environ;
67 
68 static int setenv(const char *var, const char *value, bool overwrite);
69 
70 static int
71 setenv(const char *var, const char *value, bool overwrite)
72 {
73 	int envindex = 0;
74 	const int len = strlen(var);
75 	const int val_len = strlen (value);
76 
77 	while (environ[envindex] != NULL) {
78 		if (!strncmp(environ[envindex], var, len)) {
79 			/* found it */
80 			if (overwrite) {
81 				environ[envindex] = (char *)malloc((unsigned)len + val_len + 2);
82 				sprintf(environ[envindex], "%s=%s", var, value);
83 			}
84 			return 0;
85 		}
86 		envindex++;
87 	}
88 
89 	environ[envindex] = (char *)malloc((unsigned)len + val_len + 2);
90 	sprintf(environ[envindex], "%s=%s", var, value);
91 	environ[++envindex] = NULL;
92 	return 0;
93 }
94 #endif
95 
96 
97 /* handshake interface */
98 typedef struct
99 {
100 	int status;		/* status of child */
101 	char msg[128];	/* error message */
102 	int row;		/* terminal rows */
103 	int col;		/* Terminal columns */
104 } handshake_t;
105 
106 /* status of handshake */
107 #define PTY_OK	0	/* pty open and set termios OK */
108 #define PTY_NG	1	/* pty open or set termios NG */
109 #define PTY_WS	2	/* pty need WINSIZE (row and col ) */
110 
111 
112 Shell::Shell()
113 	:
114 	fFd(-1),
115 	fProcessID(-1),
116 	fTermParse(NULL),
117 	fAttached(false)
118 {
119 }
120 
121 
122 Shell::~Shell()
123 {
124 	Close();
125 }
126 
127 
128 status_t
129 Shell::Open(int row, int col, const char *encoding, int argc, const char **argv)
130 {
131 	if (fFd >= 0)
132 		return B_ERROR;
133 
134 	status_t status = _Spawn(row, col, encoding, argc, argv);
135 	if (status < B_OK)
136 		return status;
137 
138 	fTermParse = new (std::nothrow) TermParse(fFd);
139 	if (fTermParse == NULL) {
140 		Close();
141 		return B_NO_MEMORY;
142 	}
143 
144 	return B_OK;
145 }
146 
147 
148 void
149 Shell::Close()
150 {
151 	delete fTermParse;
152 	fTermParse = NULL;
153 
154 	if (fFd >= 0) {
155 		close(fFd);
156 		kill(-fProcessID, SIGHUP);
157 		fProcessID = -1;
158 		int status;
159 		wait(&status);
160 		fFd = -1;
161 	}
162 }
163 
164 
165 const char *
166 Shell::TTYName() const
167 {
168 	return ttyname(fFd);
169 }
170 
171 
172 ssize_t
173 Shell::Read(void *buffer, size_t numBytes) const
174 {
175 	if (fFd < 0)
176 		return B_NO_INIT;
177 
178 	return read(fFd, buffer, numBytes);
179 }
180 
181 
182 ssize_t
183 Shell::Write(const void *buffer, size_t numBytes)
184 {
185 	if (fFd < 0)
186 		return B_NO_INIT;
187 
188 	return write(fFd, buffer, numBytes);
189 }
190 
191 
192 status_t
193 Shell::UpdateWindowSize(int rows, int columns)
194 {
195 	struct winsize winSize;
196 	winSize.ws_row = rows;
197 	winSize.ws_col = columns;
198 	if (ioctl(fFd, TIOCSWINSZ, &winSize) != 0)
199 		return errno;
200 	return B_OK;
201 }
202 
203 
204 status_t
205 Shell::GetAttr(struct termios &attr) const
206 {
207 	if (tcgetattr(fFd, &attr) < 0)
208 		return errno;
209 	return B_OK;
210 }
211 
212 
213 status_t
214 Shell::SetAttr(struct termios &attr)
215 {
216 	if (tcsetattr(fFd, TCSANOW, &attr) < 0)
217 		return errno;
218 	return B_OK;
219 }
220 
221 
222 int
223 Shell::FD() const
224 {
225 	return fFd;
226 }
227 
228 
229 status_t
230 Shell::AttachBuffer(TerminalBuffer *buffer)
231 {
232 	if (fAttached)
233 		return B_ERROR;
234 
235 	fAttached = true;
236 
237 	return fTermParse->StartThreads(buffer);
238 }
239 
240 
241 void
242 Shell::DetachBuffer()
243 {
244 	if (fAttached)
245 		fTermParse->StopThreads();
246 }
247 
248 
249 // private
250 static status_t
251 send_handshake_message(thread_id target, const handshake_t& handshake)
252 {
253 	return send_data(target, 0, &handshake, sizeof(handshake_t));
254 }
255 
256 
257 static void
258 receive_handshake_message(handshake_t& handshake)
259 {
260 	thread_id sender;
261 	receive_data(&sender, &handshake, sizeof(handshake_t));
262 }
263 
264 
265 static void
266 initialize_termios(struct termios &tio)
267 {
268 	/*
269 	 * Set Terminal interface.
270 	 */
271 
272 	tio.c_line = 0;
273 	tio.c_lflag |= ECHOE;
274 
275 	/* input: nl->nl, cr->nl */
276 	tio.c_iflag &= ~(INLCR|IGNCR);
277 	tio.c_iflag |= ICRNL;
278 	tio.c_iflag &= ~ISTRIP;
279 
280 	/* output: cr->cr, nl in not retrun, no delays, ln->cr/ln */
281 	tio.c_oflag &= ~(OCRNL|ONLRET|NLDLY|CRDLY|TABDLY|BSDLY|VTDLY|FFDLY);
282 	tio.c_oflag |= ONLCR;
283 	tio.c_oflag |= OPOST;
284 
285 	/* baud rate is 19200 (equal beterm) */
286 	tio.c_cflag &= ~(CBAUD);
287 	tio.c_cflag |= B19200;
288 
289 	tio.c_cflag &= ~CSIZE;
290 	tio.c_cflag |= CS8;
291 	tio.c_cflag |= CREAD;
292 
293 	tio.c_cflag |= HUPCL;
294 	tio.c_iflag &= ~(IGNBRK|BRKINT);
295 
296 	/*
297 	 * enable signals, canonical processing (erase, kill, etc), echo.
298 	*/
299 	tio.c_lflag |= ISIG|ICANON|ECHO|ECHOE|ECHONL;
300 	tio.c_lflag &= ~(ECHOK | IEXTEN);
301 
302 	/* set control characters. */
303 	tio.c_cc[VINTR]  = 'C' & 0x1f;	/* '^C'	*/
304 	tio.c_cc[VQUIT]  = CQUIT;		/* '^\'	*/
305 	tio.c_cc[VERASE] = 0x7f;		/* '^?'	*/
306 	tio.c_cc[VKILL]  = 'U' & 0x1f;	/* '^U'	*/
307 	tio.c_cc[VEOF]   = CEOF;		/* '^D' */
308 	tio.c_cc[VEOL]   = CEOL;		/* '^@' */
309 	tio.c_cc[VMIN]   = 4;
310 	tio.c_cc[VTIME]  = 0;
311 	tio.c_cc[VEOL2]  = CEOL;		/* '^@' */
312 	tio.c_cc[VSWTCH] = CSWTCH;		/* '^@' */
313 	tio.c_cc[VSTART] = CSTART;		/* '^S' */
314 	tio.c_cc[VSTOP]  = CSTOP;		/* '^Q' */
315 	tio.c_cc[VSUSP]  = CSUSP;		/* '^Z' */
316 }
317 
318 
319 status_t
320 Shell::_Spawn(int row, int col, const char *encoding, int argc, const char **argv)
321 {
322 	const char *kDefaultShellCommand[] = { "/bin/sh", "--login", NULL };
323 
324 	if (argv == NULL || argc == 0) {
325 		argv = kDefaultShellCommand;
326 		argc = 2;
327 	}
328 
329 	signal(SIGTTOU, SIG_IGN);
330 
331 #ifdef __HAIKU__
332 	// get a pseudo-tty
333 	int master = posix_openpt(O_RDWR | O_NOCTTY);
334 	const char *ttyName;
335 #else /* __HAIKU__ */
336 	/*
337 	 * Get a pseudo-tty. We do this by cycling through files in the
338 	 * directory. The operating system will not allow us to open a master
339 	 * which is already in use, so we simply go until the open succeeds.
340 	 */
341 	char ttyName[B_PATH_NAME_LENGTH];
342 	int master = -1;
343 	DIR *dir = opendir("/dev/pt/");
344 	if (dir != NULL) {
345 		struct dirent *dirEntry;
346 		while ((dirEntry = readdir(dir)) != NULL) {
347 			// skip '.' and '..'
348 			if (dirEntry->d_name[0] == '.')
349 				continue;
350 
351 			char ptyName[B_PATH_NAME_LENGTH];
352 			snprintf(ptyName, sizeof(ptyName), "/dev/pt/%s", dirEntry->d_name);
353 
354 			master = open(ptyName, O_RDWR);
355 			if (master >= 0) {
356 				// Set the tty that corresponds to the pty we found
357 				snprintf(ttyName, sizeof(ttyName), "/dev/tt/%s", dirEntry->d_name);
358 				break;
359 			} else {
360 				// B_BUSY is a normal case
361 				if (errno != B_BUSY)
362 					fprintf(stderr, "could not open %s: %s\n", ptyName, strerror(errno));
363 			}
364 		}
365 		closedir(dir);
366 	}
367 #endif /* __HAIKU__ */
368 
369 	if (master < 0) {
370     	fprintf(stderr, "Didn't find any available pseudo ttys.");
371     	return errno;
372 	}
373 
374 #ifdef __HAIKU__
375 	if (grantpt(master) != 0 || unlockpt(master) != 0
376 		|| (ttyName = ptsname(master)) == NULL) {
377 		close(master);
378     	fprintf(stderr, "Failed to init pseudo tty.");
379 		return errno;
380 	}
381 #endif /* __HAIKU__ */
382 
383 	/*
384 	 * Get the modes of the current terminal. We will duplicates these
385 	 * on the pseudo terminal.
386 	 */
387 
388 	thread_id terminalThread = find_thread(NULL);
389 
390 	/* Fork a child process. */
391 	if ((fProcessID = fork()) < 0) {
392 		close(master);
393 		return B_ERROR;
394 	}
395 
396 	handshake_t handshake;
397 
398 	if (fProcessID == 0) {
399 		// Now in child process.
400 
401 		/*
402 		 * Make our controlling tty the pseudo tty. This hapens because
403 		 * we cleared our original controlling terminal above.
404 		 */
405 
406 		/* Set process session leader */
407 		if (setsid() < 0) {
408 			handshake.status = PTY_NG;
409 			snprintf(handshake.msg, sizeof(handshake.msg),
410 				"could not set session leader.");
411 			send_handshake_message(terminalThread, handshake);
412 			exit(1);
413 		}
414 
415 		/* open slave pty */
416 		int slave = -1;
417 		if ((slave = open(ttyName, O_RDWR)) < 0) {
418 			handshake.status = PTY_NG;
419 			snprintf(handshake.msg, sizeof(handshake.msg),
420 				"can't open tty (%s).", ttyName);
421 			send_handshake_message(terminalThread, handshake);
422 			exit(1);
423 		}
424 
425 		/* set signal default */
426 		signal(SIGCHLD, SIG_DFL);
427 		signal(SIGHUP, SIG_DFL);
428 		signal(SIGQUIT, SIG_DFL);
429 		signal(SIGTERM, SIG_DFL);
430 		signal(SIGINT, SIG_DFL);
431 		signal(SIGTTOU, SIG_DFL);
432 
433 		struct termios tio;
434 		/* get tty termios (not necessary).
435 		 * TODO: so why are we doing it ?
436 		 */
437 		tcgetattr(slave, &tio);
438 
439 		initialize_termios(tio);
440 
441 		/*
442 		 * change control tty.
443 		 */
444 
445 		dup2(slave, 0);
446 		dup2(slave, 1);
447 		dup2(slave, 2);
448 
449 		/* close old slave fd. */
450 		if (slave > 2)
451 			close(slave);
452 
453 		/*
454 		 * set terminal interface.
455 		 */
456 		if (tcsetattr(0, TCSANOW, &tio) == -1) {
457 			handshake.status = PTY_NG;
458 			snprintf(handshake.msg, sizeof(handshake.msg),
459 				"failed set terminal interface (TERMIOS).");
460 			send_handshake_message(terminalThread, handshake);
461 			exit(1);
462 		}
463 
464 		/*
465 		 * set window size.
466 		 */
467 
468 		handshake.status = PTY_WS;
469 		send_handshake_message(terminalThread, handshake);
470 		receive_handshake_message(handshake);
471 
472 		if (handshake.status != PTY_WS) {
473 			handshake.status = PTY_NG;
474 			snprintf(handshake.msg, sizeof(handshake.msg),
475 				"mismatch handshake.");
476 			send_handshake_message(terminalThread, handshake);
477 			exit(1);
478 		}
479 
480 		struct winsize ws = { handshake.row, handshake.col };
481 
482 		ioctl(0, TIOCSWINSZ, &ws);
483 
484 		tcsetpgrp(0, getpgrp());
485 			// set this process group ID as the controlling terminal
486 #ifndef __HAIKU__
487 		ioctl(0, 'pgid', getpid());
488 #endif
489 		set_thread_priority(find_thread(NULL), B_NORMAL_PRIORITY);
490 
491 		/* pty open and set termios successful. */
492 		handshake.status = PTY_OK;
493 		send_handshake_message(terminalThread, handshake);
494 
495 		/*
496 		 * setenv TERM and TTY.
497 		 */
498 		setenv("TERM", "xterm", true);
499 		setenv("TTY", ttyName, true);
500 		setenv("TTYPE", encoding, true);
501 		setenv("SHELL", argv[0], true);
502 
503 		execve(argv[0], (char * const *)argv, environ);
504 
505 		/*
506 		 * Exec failed.
507 		 * TODO: This doesn't belong here.
508 		 */
509 
510 		sleep(1);
511 		const char *spawnAlertMessage = "alert --stop "
512 						"'Cannot execute \"%s\":\n"
513 						"\t%s' "
514 						"'Use default shell' 'Abort'";
515 		char errorMessage[256];
516 		snprintf(errorMessage, sizeof(errorMessage), spawnAlertMessage, argv[0], strerror(errno));
517 
518 		int returnValue = system(errorMessage);
519 		if (returnValue == 0)
520 			execl(kDefaultShellCommand[0], kDefaultShellCommand[0],
521 				kDefaultShellCommand[1], NULL);
522 
523 		exit(1);
524 	}
525 
526 	/*
527 	 * In parent Process, Set up the input and output file pointers so
528 	 * that they can write and read the pseudo terminal.
529 	 */
530 
531 	/*
532 	 * close parent control tty.
533 	 */
534 
535 	int done = 0;
536 	while (!done) {
537 		receive_handshake_message(handshake);
538 
539 		switch (handshake.status) {
540 			case PTY_OK:
541 				done = 1;
542 				break;
543 
544 			case PTY_NG:
545 				fprintf(stderr, "%s\n", handshake.msg);
546 				done = -1;
547 				break;
548 
549 			case PTY_WS:
550 				handshake.row = row;
551 				handshake.col = col;
552 				handshake.status = PTY_WS;
553 				send_handshake_message(fProcessID, handshake);
554 				break;
555 		}
556 	}
557 
558 	if (done <= 0)
559 		return B_ERROR;
560 
561 	fFd = master;
562 
563 	return B_OK;
564 }
565 
566