xref: /openbsd/usr.bin/mail/tty.c (revision cca36db2)
1 /*	$OpenBSD: tty.c,v 1.19 2009/10/27 23:59:40 deraadt 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. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Mail -- a mail program
35  *
36  * Generally useful tty stuff.
37  */
38 
39 #include "rcv.h"
40 #include "extern.h"
41 #include <sys/ioctl.h>
42 #include <errno.h>
43 
44 static	cc_t		c_erase;	/* Current erase char */
45 static	cc_t		c_kill;		/* Current kill char */
46 #ifndef TIOCSTI
47 static	int		ttyset;		/* We must now do erase/kill */
48 #endif
49 static	volatile sig_atomic_t	ttysignal;	/* Interrupted by a signal? */
50 
51 /*
52  * Read all relevant header fields.
53  */
54 int
55 grabh(struct header *hp, int gflags)
56 {
57 	struct termios ttybuf;
58 #ifndef TIOCSTI
59 	struct sigaction savequit;
60 #else
61 # ifdef	TIOCEXT
62 	int extproc;
63 	int flag;
64 # endif /* TIOCEXT */
65 #endif
66 	struct sigaction savetstp;
67 	struct sigaction savettou;
68 	struct sigaction savettin;
69 	struct sigaction act;
70 	char *s;
71 	int error;
72 
73 	sigemptyset(&act.sa_mask);
74 	act.sa_flags = SA_RESTART;
75 	act.sa_handler = SIG_DFL;
76 	(void)sigaction(SIGTSTP, &act, &savetstp);
77 	(void)sigaction(SIGTTOU, &act, &savettou);
78 	(void)sigaction(SIGTTIN, &act, &savettin);
79 	error = 1;
80 #ifndef TIOCSTI
81 	ttyset = 0;
82 #endif
83 	if (tcgetattr(fileno(stdin), &ttybuf) < 0) {
84 		warn("tcgetattr");
85 		return(-1);
86 	}
87 	c_erase = ttybuf.c_cc[VERASE];
88 	c_kill = ttybuf.c_cc[VKILL];
89 #ifndef TIOCSTI
90 	ttybuf.c_cc[VERASE] = 0;
91 	ttybuf.c_cc[VKILL] = 0;
92 	act.sa_handler = SIG_IGN;
93 	if (sigaction(SIGQUIT, &act, &savequit) == 0 &&
94 	    savequit.sa_handler == SIG_DFL)
95 		(void)sigaction(SIGQUIT, &savequit, NULL);
96 #else
97 # ifdef	TIOCEXT
98 	extproc = ((ttybuf.c_lflag & EXTPROC) ? 1 : 0);
99 	if (extproc) {
100 		flag = 0;
101 		if (ioctl(fileno(stdin), TIOCEXT, &flag) < 0)
102 			warn("TIOCEXT: off");
103 	}
104 # endif /* TIOCEXT */
105 #endif
106 	if (gflags & GTO) {
107 #ifndef TIOCSTI
108 		if (!ttyset && hp->h_to != NULL)
109 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
110 #endif
111 		s = readtty("To: ", detract(hp->h_to, 0));
112 		if (s == NULL)
113 			goto out;
114 		hp->h_to = extract(s, GTO);
115 	}
116 	if (gflags & GSUBJECT) {
117 #ifndef TIOCSTI
118 		if (!ttyset && hp->h_subject != NULL)
119 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
120 #endif
121 		s = readtty("Subject: ", hp->h_subject);
122 		if (s == NULL)
123 			goto out;
124 		hp->h_subject = s;
125 	}
126 	if (gflags & GCC) {
127 #ifndef TIOCSTI
128 		if (!ttyset && hp->h_cc != NULL)
129 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
130 #endif
131 		s = readtty("Cc: ", detract(hp->h_cc, 0));
132 		if (s == NULL)
133 			goto out;
134 		hp->h_cc = extract(s, GCC);
135 	}
136 	if (gflags & GBCC) {
137 #ifndef TIOCSTI
138 		if (!ttyset && hp->h_bcc != NULL)
139 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
140 #endif
141 		s = readtty("Bcc: ", detract(hp->h_bcc, 0));
142 		if (s == NULL)
143 			goto out;
144 		hp->h_bcc = extract(s, GBCC);
145 	}
146 	error = 0;
147 out:
148 	(void)sigaction(SIGTSTP, &savetstp, NULL);
149 	(void)sigaction(SIGTTOU, &savettou, NULL);
150 	(void)sigaction(SIGTTIN, &savettin, NULL);
151 #ifndef TIOCSTI
152 	ttybuf.c_cc[VERASE] = c_erase;
153 	ttybuf.c_cc[VKILL] = c_kill;
154 	if (ttyset)
155 		tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
156 	(void)sigaction(SIGQUIT, &savequit, NULL);
157 #else
158 # ifdef	TIOCEXT
159 	if (extproc) {
160 		flag = 1;
161 		if (ioctl(fileno(stdin), TIOCEXT, &flag) < 0)
162 			warn("TIOCEXT: on");
163 	}
164 # endif /* TIOCEXT */
165 #endif
166 	return(error);
167 }
168 
169 /*
170  * Read up a header from standard input.
171  * The source string has the preliminary contents to
172  * be read.
173  *
174  */
175 char *
176 readtty(char *pr, char *src)
177 {
178 	struct sigaction act, saveint;
179 	char ch, canonb[BUFSIZ];
180 	char *cp, *cp2;
181 	sigset_t oset;
182 	int c;
183 
184 	fputs(pr, stdout);
185 	fflush(stdout);
186 	if (src != NULL && strlen(src) > sizeof(canonb) - 2) {
187 		puts("too long to edit");
188 		return(src);
189 	}
190 #ifndef TIOCSTI
191 	if (src != NULL)
192 		cp = copy(src, canonb);	/* safe, bounds checked above */
193 	else
194 		cp = copy("", canonb);
195 	fputs(canonb, stdout);
196 	fflush(stdout);
197 #else
198 	cp = src == NULL ? "" : src;
199 	while ((c = *cp++) != '\0') {
200 		if ((c_erase != _POSIX_VDISABLE && c == c_erase) ||
201 		    (c_kill != _POSIX_VDISABLE && c == c_kill)) {
202 			ch = '\\';
203 			ioctl(0, TIOCSTI, &ch);
204 		}
205 		ch = c;
206 		ioctl(0, TIOCSTI, &ch);
207 	}
208 	cp = canonb;
209 	*cp = 0;
210 #endif
211 	sigemptyset(&act.sa_mask);
212 	act.sa_flags = 0;		/* Note: will not restart syscalls */
213 	act.sa_handler = ttyint;
214 	(void)sigaction(SIGINT, &act, &saveint);
215 	act.sa_handler = ttystop;
216 	(void)sigaction(SIGTSTP, &act, NULL);
217 	(void)sigaction(SIGTTOU, &act, NULL);
218 	(void)sigaction(SIGTTIN, &act, NULL);
219 	(void)sigprocmask(SIG_UNBLOCK, &intset, &oset);
220 	clearerr(stdin);
221 	memset(cp, 0, canonb + sizeof(canonb) - cp);
222 	for (cp2 = cp; cp2 < canonb + sizeof(canonb) - 1; ) {
223 		c = getc(stdin);
224 		switch (ttysignal) {
225 			case SIGINT:
226 				ttysignal = 0;
227 				cp2 = NULL;
228 				c = EOF;
229 				/* FALLTHROUGH */
230 			case 0:
231 				break;
232 			default:
233 				ttysignal = 0;
234 				goto redo;
235 		}
236 		if (c == EOF || c == '\n')
237 			break;
238 		*cp2++ = c;
239 	}
240 	act.sa_handler = SIG_DFL;
241 	sigemptyset(&act.sa_mask);
242 	act.sa_flags = SA_RESTART;
243 	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
244 	(void)sigaction(SIGTSTP, &act, NULL);
245 	(void)sigaction(SIGTTOU, &act, NULL);
246 	(void)sigaction(SIGTTIN, &act, NULL);
247 	(void)sigaction(SIGINT, &saveint, NULL);
248 	if (cp2 == NULL)
249 		return(NULL);			/* user hit ^C */
250 	*cp2 = '\0';
251 	if (c == EOF && ferror(stdin)) {
252 redo:
253 		cp = strlen(canonb) > 0 ? canonb : NULL;
254 		clearerr(stdin);
255 		/* XXX - make iterative, not recursive */
256 		return(readtty(pr, cp));
257 	}
258 #ifndef TIOCSTI
259 	if (cp == NULL || *cp == '\0')
260 		return(src);
261 	cp2 = cp;
262 	if (!ttyset)
263 		return(strlen(canonb) > 0 ? savestr(canonb) : NULL);
264 	while (*cp != '\0') {
265 		c = *cp++;
266 		if (c_erase != _POSIX_VDISABLE && c == c_erase) {
267 			if (cp2 == canonb)
268 				continue;
269 			if (cp2[-1] == '\\') {
270 				cp2[-1] = c;
271 				continue;
272 			}
273 			cp2--;
274 			continue;
275 		}
276 		if (c_kill != _POSIX_VDISABLE && c == c_kill) {
277 			if (cp2 == canonb)
278 				continue;
279 			if (cp2[-1] == '\\') {
280 				cp2[-1] = c;
281 				continue;
282 			}
283 			cp2 = canonb;
284 			continue;
285 		}
286 		*cp2++ = c;
287 	}
288 	*cp2 = '\0';
289 #endif
290 	if (equal("", canonb))
291 		return("");
292 	return(savestr(canonb));
293 }
294 
295 /*
296  * Receipt continuation.
297  */
298 void
299 ttystop(int s)
300 {
301 	struct sigaction act, oact;
302 	sigset_t nset;
303 	int save_errno;
304 
305 	/*
306 	 * Save old handler and set to default.
307 	 * Unblock receipt of 's' and then resend it.
308 	 */
309 	save_errno = errno;
310 	(void)sigemptyset(&act.sa_mask);
311 	act.sa_flags = SA_RESTART;
312 	act.sa_handler = SIG_DFL;
313 	(void)sigaction(s, &act, &oact);
314 	(void)sigemptyset(&nset);
315 	(void)sigaddset(&nset, s);
316 	(void)sigprocmask(SIG_UNBLOCK, &nset, NULL);
317 	(void)kill(0, s);
318 	(void)sigprocmask(SIG_BLOCK, &nset, NULL);
319 	(void)sigaction(s, &oact, NULL);
320 	ttysignal = s;
321 	errno = save_errno;
322 }
323 
324 /*ARGSUSED*/
325 void
326 ttyint(int s)
327 {
328 
329 	ttysignal = s;
330 }
331