xref: /freebsd/usr.bin/mail/tty.c (revision 3c4ba5f55438f7afd4f4b0b56f88f2bb505fd6a6)
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 __FBSDID("$FreeBSD$");
39 
40 /*
41  * Mail -- a mail program
42  *
43  * Generally useful tty stuff.
44  */
45 
46 #include "rcv.h"
47 #include "extern.h"
48 
49 static	cc_t	c_erase;		/* Current erase char */
50 static	cc_t	c_kill;			/* Current kill char */
51 static	jmp_buf	rewrite;		/* Place to go when continued */
52 static	jmp_buf	intjmp;			/* Place to go when interrupted */
53 #ifndef TIOCSTI
54 static	int	ttyset;			/* We must now do erase/kill */
55 #endif
56 
57 /*
58  * Read all relevant header fields.
59  */
60 
61 int
62 grabh(struct header *hp, int gflags)
63 {
64 	struct termios ttybuf;
65 	sig_t saveint;
66 	sig_t savetstp;
67 	sig_t savettou;
68 	sig_t savettin;
69 	int errs;
70 #ifndef TIOCSTI
71 	sig_t savequit;
72 #else
73 # ifdef TIOCEXT
74 	int extproc, flag;
75 # endif /* TIOCEXT */
76 #endif /* TIOCSTI */
77 
78 	savetstp = signal(SIGTSTP, SIG_DFL);
79 	savettou = signal(SIGTTOU, SIG_DFL);
80 	savettin = signal(SIGTTIN, SIG_DFL);
81 	errs = 0;
82 #ifndef TIOCSTI
83 	ttyset = 0;
84 #endif
85 	if (tcgetattr(fileno(stdin), &ttybuf) < 0) {
86 		warn("tcgetattr(stdin)");
87 		return (-1);
88 	}
89 	c_erase = ttybuf.c_cc[VERASE];
90 	c_kill = ttybuf.c_cc[VKILL];
91 #ifndef TIOCSTI
92 	ttybuf.c_cc[VERASE] = _POSIX_VDISABLE;
93 	ttybuf.c_cc[VKILL] = _POSIX_VDISABLE;
94 	if ((saveint = signal(SIGINT, SIG_IGN)) == SIG_DFL)
95 		(void)signal(SIGINT, SIG_DFL);
96 	if ((savequit = signal(SIGQUIT, SIG_IGN)) == SIG_DFL)
97 		(void)signal(SIGQUIT, SIG_DFL);
98 #else
99 # ifdef		TIOCEXT
100 	extproc = ((ttybuf.c_lflag & EXTPROC) ? 1 : 0);
101 	if (extproc) {
102 		flag = 0;
103 		if (ioctl(fileno(stdin), TIOCEXT, &flag) < 0)
104 			warn("TIOCEXT: off");
105 	}
106 # endif	/* TIOCEXT */
107 	if (setjmp(intjmp))
108 		goto out;
109 	saveint = signal(SIGINT, ttyint);
110 #endif
111 	if (gflags & GTO) {
112 #ifndef TIOCSTI
113 		if (!ttyset && hp->h_to != NULL)
114 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
115 #endif
116 		hp->h_to =
117 			extract(readtty("To: ", detract(hp->h_to, 0)), GTO);
118 	}
119 	if (gflags & GSUBJECT) {
120 #ifndef TIOCSTI
121 		if (!ttyset && hp->h_subject != NULL)
122 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
123 #endif
124 		hp->h_subject = readtty("Subject: ", hp->h_subject);
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 		hp->h_cc =
132 			extract(readtty("Cc: ", detract(hp->h_cc, 0)), GCC);
133 	}
134 	if (gflags & GBCC) {
135 #ifndef TIOCSTI
136 		if (!ttyset && hp->h_bcc != NULL)
137 			ttyset++, tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
138 #endif
139 		hp->h_bcc =
140 			extract(readtty("Bcc: ", detract(hp->h_bcc, 0)), GBCC);
141 	}
142 #ifdef TIOCSTI
143 out:
144 #endif
145 	(void)signal(SIGTSTP, savetstp);
146 	(void)signal(SIGTTOU, savettou);
147 	(void)signal(SIGTTIN, savettin);
148 #ifndef TIOCSTI
149 	ttybuf.c_cc[VERASE] = c_erase;
150 	ttybuf.c_cc[VKILL] = c_kill;
151 	if (ttyset)
152 		tcsetattr(fileno(stdin), TCSADRAIN, &ttybuf);
153 	(void)signal(SIGQUIT, savequit);
154 #else
155 # ifdef		TIOCEXT
156 	if (extproc) {
157 		flag = 1;
158 		if (ioctl(fileno(stdin), TIOCEXT, &flag) < 0)
159 			warn("TIOCEXT: on");
160 	}
161 # endif	/* TIOCEXT */
162 #endif
163 	(void)signal(SIGINT, saveint);
164 	return (errs);
165 }
166 
167 /*
168  * Read up a header from standard input.
169  * The source string has the preliminary contents to
170  * be read.
171  *
172  */
173 
174 char *
175 readtty(const char *pr, char src[])
176 {
177 	char canonb[BUFSIZ];
178 #ifdef TIOCSTI
179 	char ch;
180 #endif
181 	int c;
182 	char *cp, *cp2;
183 
184 	fputs(pr, stdout);
185 	(void)fflush(stdout);
186 	if (src != NULL && strlen(src) > BUFSIZ - 2) {
187 		printf("too long to edit\n");
188 		return (src);
189 	}
190 #ifndef TIOCSTI
191 	if (src != NULL)
192 		strlcpy(canonb, src, sizeof(canonb));
193 	else
194 		*canonb = '\0';
195 	fputs(canonb, stdout);
196 	(void)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 	cp2 = cp;
212 	while (cp2 < canonb + BUFSIZ)
213 		*cp2++ = '\0';
214 	cp2 = cp;
215 	if (setjmp(rewrite))
216 		goto redo;
217 	(void)signal(SIGTSTP, ttystop);
218 	(void)signal(SIGTTOU, ttystop);
219 	(void)signal(SIGTTIN, ttystop);
220 	clearerr(stdin);
221 	while (cp2 < canonb + BUFSIZ) {
222 		c = getc(stdin);
223 		if (c == EOF || c == '\n')
224 			break;
225 		*cp2++ = c;
226 	}
227 	*cp2 = '\0';
228 	(void)signal(SIGTSTP, SIG_DFL);
229 	(void)signal(SIGTTOU, SIG_DFL);
230 	(void)signal(SIGTTIN, SIG_DFL);
231 	if (c == EOF && ferror(stdin)) {
232 redo:
233 		cp = strlen(canonb) > 0 ? canonb : NULL;
234 		clearerr(stdin);
235 		return (readtty(pr, cp));
236 	}
237 #ifndef TIOCSTI
238 	if (cp == NULL || *cp == '\0')
239 		return (src);
240 	cp2 = cp;
241 	if (!ttyset)
242 		return (strlen(canonb) > 0 ? savestr(canonb) : NULL);
243 	while (*cp != '\0') {
244 		c = *cp++;
245 		if (c_erase != _POSIX_VDISABLE && c == c_erase) {
246 			if (cp2 == canonb)
247 				continue;
248 			if (cp2[-1] == '\\') {
249 				cp2[-1] = c;
250 				continue;
251 			}
252 			cp2--;
253 			continue;
254 		}
255 		if (c_kill != _POSIX_VDISABLE && c == c_kill) {
256 			if (cp2 == canonb)
257 				continue;
258 			if (cp2[-1] == '\\') {
259 				cp2[-1] = c;
260 				continue;
261 			}
262 			cp2 = canonb;
263 			continue;
264 		}
265 		*cp2++ = c;
266 	}
267 	*cp2 = '\0';
268 #endif
269 	if (equal("", canonb))
270 		return (NULL);
271 	return (savestr(canonb));
272 }
273 
274 /*
275  * Receipt continuation.
276  */
277 void
278 ttystop(int s)
279 {
280 	sig_t old_action = signal(s, SIG_DFL);
281 	sigset_t nset;
282 
283 	(void)sigemptyset(&nset);
284 	(void)sigaddset(&nset, s);
285 	(void)sigprocmask(SIG_BLOCK, &nset, NULL);
286 	kill(0, s);
287 	(void)sigprocmask(SIG_UNBLOCK, &nset, NULL);
288 	(void)signal(s, old_action);
289 	longjmp(rewrite, 1);
290 }
291 
292 void
293 ttyint(int s __unused)
294 {
295 	longjmp(intjmp, 1);
296 }
297