xref: /freebsd/usr.bin/mail/tty.c (revision 61ba55bcf70f2340f9c943c9571113b3fd8eda69)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1980, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 #if 0
34 static char sccsid[] = "@(#)tty.c	8.2 (Berkeley) 6/6/93";
35 #endif
36 #endif /* not lint */
37 #include <sys/cdefs.h>
38 /*
39  * Mail -- a mail program
40  *
41  * Generally useful tty stuff.
42  */
43 
44 #include "rcv.h"
45 #include "extern.h"
46 
47 static	cc_t	c_erase;		/* Current erase char */
48 static	cc_t	c_kill;			/* Current kill char */
49 static	jmp_buf	rewrite;		/* Place to go when continued */
50 static	jmp_buf	intjmp;			/* Place to go when interrupted */
51 #ifndef TIOCSTI
52 static	int	ttyset;			/* We must now do erase/kill */
53 #endif
54 
55 /*
56  * Read all relevant header fields.
57  */
58 
59 int
60 grabh(struct header *hp, int gflags)
61 {
62 	struct termios ttybuf;
63 	sig_t saveint;
64 	sig_t savetstp;
65 	sig_t savettou;
66 	sig_t savettin;
67 	int errs;
68 #ifndef TIOCSTI
69 	sig_t savequit;
70 #else
71 # ifdef TIOCEXT
72 	int extproc, flag;
73 # endif /* TIOCEXT */
74 #endif /* TIOCSTI */
75 
76 	savetstp = signal(SIGTSTP, SIG_DFL);
77 	savettou = signal(SIGTTOU, SIG_DFL);
78 	savettin = signal(SIGTTIN, SIG_DFL);
79 	errs = 0;
80 #ifndef TIOCSTI
81 	ttyset = 0;
82 #endif
83 	if (tcgetattr(fileno(stdin), &ttybuf) < 0) {
84 		warn("tcgetattr(stdin)");
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] = _POSIX_VDISABLE;
91 	ttybuf.c_cc[VKILL] = _POSIX_VDISABLE;
92 	if ((saveint = signal(SIGINT, SIG_IGN)) == SIG_DFL)
93 		(void)signal(SIGINT, SIG_DFL);
94 	if ((savequit = signal(SIGQUIT, SIG_IGN)) == SIG_DFL)
95 		(void)signal(SIGQUIT, SIG_DFL);
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 	if (setjmp(intjmp))
106 		goto out;
107 	saveint = signal(SIGINT, ttyint);
108 #endif
109 	if (gflags & GTO) {
110 #ifndef TIOCSTI
111 		if (!ttyset && hp->h_to != NULL)
112 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
113 #endif
114 		hp->h_to =
115 			extract(readtty("To: ", detract(hp->h_to, 0)), GTO);
116 	}
117 	if (gflags & GSUBJECT) {
118 #ifndef TIOCSTI
119 		if (!ttyset && hp->h_subject != NULL)
120 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
121 #endif
122 		hp->h_subject = readtty("Subject: ", hp->h_subject);
123 	}
124 	if (gflags & GCC) {
125 #ifndef TIOCSTI
126 		if (!ttyset && hp->h_cc != NULL)
127 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
128 #endif
129 		hp->h_cc =
130 			extract(readtty("Cc: ", detract(hp->h_cc, 0)), GCC);
131 	}
132 	if (gflags & GBCC) {
133 #ifndef TIOCSTI
134 		if (!ttyset && hp->h_bcc != NULL)
135 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
136 #endif
137 		hp->h_bcc =
138 			extract(readtty("Bcc: ", detract(hp->h_bcc, 0)), GBCC);
139 	}
140 #ifdef TIOCSTI
141 out:
142 #endif
143 	(void)signal(SIGTSTP, savetstp);
144 	(void)signal(SIGTTOU, savettou);
145 	(void)signal(SIGTTIN, savettin);
146 #ifndef TIOCSTI
147 	ttybuf.c_cc[VERASE] = c_erase;
148 	ttybuf.c_cc[VKILL] = c_kill;
149 	if (ttyset)
150 		tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
151 	(void)signal(SIGQUIT, savequit);
152 #else
153 # ifdef		TIOCEXT
154 	if (extproc) {
155 		flag = 1;
156 		if (ioctl(fileno(stdin), TIOCEXT, &flag) < 0)
157 			warn("TIOCEXT: on");
158 	}
159 # endif	/* TIOCEXT */
160 #endif
161 	(void)signal(SIGINT, saveint);
162 	return (errs);
163 }
164 
165 /*
166  * Read up a header from standard input.
167  * The source string has the preliminary contents to
168  * be read.
169  *
170  */
171 
172 char *
173 readtty(const char *pr, char src[])
174 {
175 	char canonb[BUFSIZ];
176 #ifdef TIOCSTI
177 	char ch;
178 #endif
179 	int c;
180 	char *cp, *cp2;
181 
182 	fputs(pr, stdout);
183 	(void)fflush(stdout);
184 	if (src != NULL && strlen(src) > BUFSIZ - 2) {
185 		printf("too long to edit\n");
186 		return (src);
187 	}
188 #ifndef TIOCSTI
189 	if (src != NULL)
190 		strlcpy(canonb, src, sizeof(canonb));
191 	else
192 		*canonb = '\0';
193 	fputs(canonb, stdout);
194 	(void)fflush(stdout);
195 #else
196 	cp = src == NULL ? "" : src;
197 	while ((c = *cp++) != '\0') {
198 		if ((c_erase != _POSIX_VDISABLE && c == c_erase) ||
199 		    (c_kill != _POSIX_VDISABLE && c == c_kill)) {
200 			ch = '\\';
201 			ioctl(0, TIOCSTI, &ch);
202 		}
203 		ch = c;
204 		ioctl(0, TIOCSTI, &ch);
205 	}
206 	cp = canonb;
207 	*cp = '\0';
208 #endif
209 	cp2 = cp;
210 	while (cp2 < canonb + BUFSIZ)
211 		*cp2++ = '\0';
212 	cp2 = cp;
213 	if (setjmp(rewrite))
214 		goto redo;
215 	(void)signal(SIGTSTP, ttystop);
216 	(void)signal(SIGTTOU, ttystop);
217 	(void)signal(SIGTTIN, ttystop);
218 	clearerr(stdin);
219 	while (cp2 < canonb + BUFSIZ) {
220 		c = getc(stdin);
221 		if (c == EOF || c == '\n')
222 			break;
223 		*cp2++ = c;
224 	}
225 	*cp2 = '\0';
226 	(void)signal(SIGTSTP, SIG_DFL);
227 	(void)signal(SIGTTOU, SIG_DFL);
228 	(void)signal(SIGTTIN, SIG_DFL);
229 	if (c == EOF && ferror(stdin)) {
230 redo:
231 		cp = strlen(canonb) > 0 ? canonb : NULL;
232 		clearerr(stdin);
233 		return (readtty(pr, cp));
234 	}
235 #ifndef TIOCSTI
236 	if (cp == NULL || *cp == '\0')
237 		return (src);
238 	cp2 = cp;
239 	if (!ttyset)
240 		return (strlen(canonb) > 0 ? savestr(canonb) : NULL);
241 	while (*cp != '\0') {
242 		c = *cp++;
243 		if (c_erase != _POSIX_VDISABLE && c == c_erase) {
244 			if (cp2 == canonb)
245 				continue;
246 			if (cp2[-1] == '\\') {
247 				cp2[-1] = c;
248 				continue;
249 			}
250 			cp2--;
251 			continue;
252 		}
253 		if (c_kill != _POSIX_VDISABLE && c == c_kill) {
254 			if (cp2 == canonb)
255 				continue;
256 			if (cp2[-1] == '\\') {
257 				cp2[-1] = c;
258 				continue;
259 			}
260 			cp2 = canonb;
261 			continue;
262 		}
263 		*cp2++ = c;
264 	}
265 	*cp2 = '\0';
266 #endif
267 	if (equal("", canonb))
268 		return (NULL);
269 	return (savestr(canonb));
270 }
271 
272 /*
273  * Receipt continuation.
274  */
275 void
276 ttystop(int s)
277 {
278 	sig_t old_action = signal(s, SIG_DFL);
279 	sigset_t nset;
280 
281 	(void)sigemptyset(&nset);
282 	(void)sigaddset(&nset, s);
283 	(void)sigprocmask(SIG_BLOCK, &nset, NULL);
284 	kill(0, s);
285 	(void)sigprocmask(SIG_UNBLOCK, &nset, NULL);
286 	(void)signal(s, old_action);
287 	longjmp(rewrite, 1);
288 }
289 
290 void
291 ttyint(int s __unused)
292 {
293 	longjmp(intjmp, 1);
294 }
295