xref: /openbsd/usr.bin/mail/tty.c (revision 78b63d65)
1 /*	$OpenBSD: tty.c,v 1.16 2001/11/28 01:04:34 millert Exp $	*/
2 /*	$NetBSD: tty.c,v 1.7 1997/07/09 05:25:46 mikel Exp $	*/
3 
4 /*
5  * Copyright (c) 1980, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #ifndef lint
38 #if 0
39 static const char sccsid[] = "@(#)tty.c	8.2 (Berkeley) 4/20/95";
40 #else
41 static const char rcsid[] = "$OpenBSD: tty.c,v 1.16 2001/11/28 01:04:34 millert Exp $";
42 #endif
43 #endif /* not lint */
44 
45 /*
46  * Mail -- a mail program
47  *
48  * Generally useful tty stuff.
49  */
50 
51 #include "rcv.h"
52 #include "extern.h"
53 #include <sys/ioctl.h>
54 #include <errno.h>
55 
56 static	cc_t		c_erase;	/* Current erase char */
57 static	cc_t		c_kill;		/* Current kill char */
58 #ifndef TIOCSTI
59 static	int		ttyset;		/* We must now do erase/kill */
60 #endif
61 static	volatile sig_atomic_t	ttysignal;	/* Interrupted by a signal? */
62 
63 /*
64  * Read all relevant header fields.
65  */
66 int
67 grabh(struct header *hp, int gflags)
68 {
69 	struct termios ttybuf;
70 #ifndef TIOCSTI
71 	struct sigaction savequit;
72 #else
73 # ifdef	TIOCEXT
74 	int extproc;
75 	int flag;
76 # endif /* TIOCEXT */
77 #endif
78 	struct sigaction savetstp;
79 	struct sigaction savettou;
80 	struct sigaction savettin;
81 	struct sigaction act;
82 	char *s;
83 	int error;
84 
85 	sigemptyset(&act.sa_mask);
86 	act.sa_flags = SA_RESTART;
87 	act.sa_handler = SIG_DFL;
88 	(void)sigaction(SIGTSTP, &act, &savetstp);
89 	(void)sigaction(SIGTTOU, &act, &savettou);
90 	(void)sigaction(SIGTTIN, &act, &savettin);
91 	error = 1;
92 #ifndef TIOCSTI
93 	ttyset = 0;
94 #endif
95 	if (tcgetattr(fileno(stdin), &ttybuf) < 0) {
96 		warn("tcgetattr");
97 		return(-1);
98 	}
99 	c_erase = ttybuf.c_cc[VERASE];
100 	c_kill = ttybuf.c_cc[VKILL];
101 #ifndef TIOCSTI
102 	ttybuf.c_cc[VERASE] = 0;
103 	ttybuf.c_cc[VKILL] = 0;
104 	act.sa_handler = SIG_IGN;
105 	if (sigaction(SIGQUIT, &act, &savequit) == 0 &&
106 	    savequit.sa_handler == SIG_DFL)
107 		(void)sigaction(SIGQUIT, &savequit, NULL);
108 #else
109 # ifdef	TIOCEXT
110 	extproc = ((ttybuf.c_lflag & EXTPROC) ? 1 : 0);
111 	if (extproc) {
112 		flag = 0;
113 		if (ioctl(fileno(stdin), TIOCEXT, &flag) < 0)
114 			warn("TIOCEXT: off");
115 	}
116 # endif /* TIOCEXT */
117 #endif
118 	if (gflags & GTO) {
119 #ifndef TIOCSTI
120 		if (!ttyset && hp->h_to != NULL)
121 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
122 #endif
123 		s = readtty("To: ", detract(hp->h_to, 0));
124 		if (s == NULL)
125 			goto out;
126 		hp->h_to = extract(s, GTO);
127 	}
128 	if (gflags & GSUBJECT) {
129 #ifndef TIOCSTI
130 		if (!ttyset && hp->h_subject != NULL)
131 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
132 #endif
133 		s = readtty("Subject: ", hp->h_subject);
134 		if (s == NULL)
135 			goto out;
136 		hp->h_subject = s;
137 	}
138 	if (gflags & GCC) {
139 #ifndef TIOCSTI
140 		if (!ttyset && hp->h_cc != NULL)
141 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
142 #endif
143 		s = readtty("Cc: ", detract(hp->h_cc, 0));
144 		if (s == NULL)
145 			goto out;
146 		hp->h_cc = extract(s, GCC);
147 	}
148 	if (gflags & GBCC) {
149 #ifndef TIOCSTI
150 		if (!ttyset && hp->h_bcc != NULL)
151 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
152 #endif
153 		s = readtty("Bcc: ", detract(hp->h_bcc, 0));
154 		if (s == NULL)
155 			goto out;
156 		hp->h_bcc = extract(s, GBCC);
157 	}
158 	error = 0;
159 out:
160 	(void)sigaction(SIGTSTP, &savetstp, NULL);
161 	(void)sigaction(SIGTTOU, &savettou, NULL);
162 	(void)sigaction(SIGTTIN, &savettin, NULL);
163 #ifndef TIOCSTI
164 	ttybuf.c_cc[VERASE] = c_erase;
165 	ttybuf.c_cc[VKILL] = c_kill;
166 	if (ttyset)
167 		tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
168 	(void)sigaction(SIGQUIT, &savequit, NULL);
169 #else
170 # ifdef	TIOCEXT
171 	if (extproc) {
172 		flag = 1;
173 		if (ioctl(fileno(stdin), TIOCEXT, &flag) < 0)
174 			warn("TIOCEXT: on");
175 	}
176 # endif /* TIOCEXT */
177 #endif
178 	return(error);
179 }
180 
181 /*
182  * Read up a header from standard input.
183  * The source string has the preliminary contents to
184  * be read.
185  *
186  */
187 char *
188 readtty(char *pr, char *src)
189 {
190 	struct sigaction act, saveint;
191 	char ch, canonb[BUFSIZ];
192 	char *cp, *cp2;
193 	sigset_t oset;
194 	int c;
195 
196 	fputs(pr, stdout);
197 	fflush(stdout);
198 	if (src != NULL && strlen(src) > BUFSIZ - 2) {
199 		puts("too long to edit");
200 		return(src);
201 	}
202 #ifndef TIOCSTI
203 	if (src != NULL)
204 		cp = copy(src, canonb);	/* safe, bounds checked above */
205 	else
206 		cp = copy("", canonb);
207 	fputs(canonb, stdout);
208 	fflush(stdout);
209 #else
210 	cp = src == NULL ? "" : src;
211 	while ((c = *cp++) != '\0') {
212 		if ((c_erase != _POSIX_VDISABLE && c == c_erase) ||
213 		    (c_kill != _POSIX_VDISABLE && c == c_kill)) {
214 			ch = '\\';
215 			ioctl(0, TIOCSTI, &ch);
216 		}
217 		ch = c;
218 		ioctl(0, TIOCSTI, &ch);
219 	}
220 	cp = canonb;
221 	*cp = 0;
222 #endif
223 	cp2 = cp;
224 	while (cp2 < canonb + BUFSIZ)
225 		*cp2++ = 0;
226 	cp2 = cp;
227 	sigemptyset(&act.sa_mask);
228 	act.sa_flags = 0;		/* Note: will not restart syscalls */
229 	act.sa_handler = ttyint;
230 	(void)sigaction(SIGINT, &act, &saveint);
231 	act.sa_handler = ttystop;
232 	(void)sigaction(SIGTSTP, &act, NULL);
233 	(void)sigaction(SIGTTOU, &act, NULL);
234 	(void)sigaction(SIGTTIN, &act, NULL);
235 	(void)sigprocmask(SIG_UNBLOCK, &intset, &oset);
236 	clearerr(stdin);
237 	while (cp2 < canonb + BUFSIZ) {
238 		c = getc(stdin);
239 		switch (ttysignal) {
240 			case SIGINT:
241 				ttysignal = 0;
242 				cp2 = NULL;
243 				c = EOF;
244 				/* FALLTHROUGH */
245 			case 0:
246 				break;
247 			default:
248 				ttysignal = 0;
249 				goto redo;
250 		}
251 		if (c == EOF || c == '\n')
252 			break;
253 		*cp2++ = c;
254 	}
255 	act.sa_handler = SIG_DFL;
256 	sigemptyset(&act.sa_mask);
257 	act.sa_flags = SA_RESTART;
258 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
259 	(void)sigaction(SIGTSTP, &act, NULL);
260 	(void)sigaction(SIGTTOU, &act, NULL);
261 	(void)sigaction(SIGTTIN, &act, NULL);
262 	(void)sigaction(SIGINT, &saveint, NULL);
263 	if (cp2 == NULL)
264 		return(NULL);			/* user hit ^C */
265 	*cp2 = '\0';
266 	if (c == EOF && ferror(stdin)) {
267 redo:
268 		cp = strlen(canonb) > 0 ? canonb : NULL;
269 		clearerr(stdin);
270 		/* XXX - make iterative, not recursive */
271 		return(readtty(pr, cp));
272 	}
273 #ifndef TIOCSTI
274 	if (cp == NULL || *cp == '\0')
275 		return(src);
276 	cp2 = cp;
277 	if (!ttyset)
278 		return(strlen(canonb) > 0 ? savestr(canonb) : NULL);
279 	while (*cp != '\0') {
280 		c = *cp++;
281 		if (c_erase != _POSIX_VDISABLE && c == c_erase) {
282 			if (cp2 == canonb)
283 				continue;
284 			if (cp2[-1] == '\\') {
285 				cp2[-1] = c;
286 				continue;
287 			}
288 			cp2--;
289 			continue;
290 		}
291 		if (c_kill != _POSIX_VDISABLE && c == c_kill) {
292 			if (cp2 == canonb)
293 				continue;
294 			if (cp2[-1] == '\\') {
295 				cp2[-1] = c;
296 				continue;
297 			}
298 			cp2 = canonb;
299 			continue;
300 		}
301 		*cp2++ = c;
302 	}
303 	*cp2 = '\0';
304 #endif
305 	if (equal("", canonb))
306 		return("");
307 	return(savestr(canonb));
308 }
309 
310 /*
311  * Receipt continuation.
312  */
313 void
314 ttystop(int s)
315 {
316 	struct sigaction act, oact;
317 	sigset_t nset;
318 	int save_errno;
319 
320 	/*
321 	 * Save old handler and set to default.
322 	 * Unblock receipt of 's' and then resend it.
323 	 */
324 	save_errno = errno;
325 	(void)sigemptyset(&act.sa_mask);
326 	act.sa_flags = SA_RESTART;
327 	act.sa_handler = SIG_DFL;
328 	(void)sigaction(s, &act, &oact);
329 	(void)sigemptyset(&nset);
330 	(void)sigaddset(&nset, s);
331 	(void)sigprocmask(SIG_UNBLOCK, &nset, NULL);
332 	(void)kill(0, s);
333 	(void)sigprocmask(SIG_BLOCK, &nset, NULL);
334 	(void)sigaction(s, &oact, NULL);
335 	ttysignal = s;
336 	errno = save_errno;
337 }
338 
339 /*ARGSUSED*/
340 void
341 ttyint(int s)
342 {
343 
344 	ttysignal = s;
345 }
346