xref: /openbsd-src/usr.bin/cu/cu.c (revision 4c1e55dc91edd6e69ccc60ce855900fbc12cf34f)
1 /* $OpenBSD: cu.c,v 1.11 2012/07/13 14:45:24 halex Exp $ */
2 
3 /*
4  * Copyright (c) 2012 Nicholas Marriott <nicm@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/param.h>
20 #include <sys/ioctl.h>
21 
22 #include <ctype.h>
23 #include <err.h>
24 #include <event.h>
25 #include <fcntl.h>
26 #include <getopt.h>
27 #include <paths.h>
28 #include <pwd.h>
29 #include <signal.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <termios.h>
34 #include <unistd.h>
35 
36 #include "cu.h"
37 
38 extern char		*__progname;
39 
40 FILE			*record_file;
41 struct termios		 saved_tio;
42 struct bufferevent	*input_ev;
43 struct bufferevent	*output_ev;
44 int			 line_fd;
45 struct bufferevent	*line_ev;
46 struct event		 sigterm_ev;
47 struct event		 sighup_ev;
48 enum {
49 	STATE_NONE,
50 	STATE_NEWLINE,
51 	STATE_TILDE
52 } last_state = STATE_NEWLINE;
53 
54 __dead void	usage(void);
55 void		signal_event(int, short, void *);
56 void		stream_read(struct bufferevent *, void *);
57 void		stream_error(struct bufferevent *, short, void *);
58 void		line_read(struct bufferevent *, void *);
59 void		line_error(struct bufferevent *, short, void *);
60 
61 __dead void
62 usage(void)
63 {
64 	fprintf(stderr, "usage: %s [-l line] [-s speed | -speed]\n",
65 	    __progname);
66 	exit(1);
67 }
68 
69 int
70 main(int argc, char **argv)
71 {
72 	const char	*line, *errstr;
73 	char		*tmp;
74 	int		 opt, speed, i;
75 
76 	line = "/dev/cua00";
77 	speed = 9600;
78 
79 	/*
80 	 * Convert obsolescent -### speed to modern -s### syntax which getopt()
81 	 * can handle.
82 	 */
83 	for (i = 1; i < argc; i++) {
84 		if (strcmp("--", argv[i]) == 0)
85 			break;
86 		if (argv[i][0] != '-' || !isdigit(argv[i][1]))
87 			continue;
88 
89 		if (asprintf(&argv[i], "-s%s", &argv[i][1]) == -1)
90 			errx(1, "speed asprintf");
91 	}
92 
93 	while ((opt = getopt(argc, argv, "l:s:")) != -1) {
94 		switch (opt) {
95 		case 'l':
96 			line = optarg;
97 			break;
98 		case 's':
99 			speed = strtonum(optarg, 0, UINT_MAX, &errstr);
100 			if (errstr != NULL)
101 				errx(1, "speed is %s: %s", errstr, optarg);
102 			break;
103 		default:
104 			usage();
105 		}
106 	}
107 	argc -= optind;
108 	argv += optind;
109 	if (argc != 0)
110 		usage();
111 
112 	if (strchr(line, '/') == NULL) {
113 		if (asprintf(&tmp, "%s%s", _PATH_DEV, line) == -1)
114 			err(1, "asprintf");
115 		line = tmp;
116 	}
117 
118 	line_fd = open(line, O_RDWR);
119 	if (line_fd < 0)
120 		err(1, "open(\"%s\")", line);
121 	if (ioctl(line_fd, TIOCEXCL) != 0)
122 		err(1, "ioctl(TIOCEXCL)");
123 
124 	if (set_line(speed) != 0)
125 		err(1, "tcsetattr");
126 
127 	if (isatty(STDIN_FILENO) && tcgetattr(STDIN_FILENO, &saved_tio) != 0)
128 		err(1, "tcgetattr");
129 
130 	event_init();
131 
132 	signal_set(&sigterm_ev, SIGTERM, signal_event, NULL);
133 	signal_add(&sigterm_ev, NULL);
134 	signal_set(&sighup_ev, SIGHUP, signal_event, NULL);
135 	signal_add(&sighup_ev, NULL);
136 	if (signal(SIGINT, SIG_IGN) == SIG_ERR)
137 		err(1, "signal");
138 	if (signal(SIGQUIT, SIG_IGN) == SIG_ERR)
139 		err(1, "signal");
140 
141 	set_termios(); /* after this use cu_err and friends */
142 
143 	/* stdin and stdout get separate events */
144 	input_ev = bufferevent_new(STDIN_FILENO, stream_read, NULL,
145 	    stream_error, NULL);
146 	bufferevent_enable(input_ev, EV_READ);
147 	output_ev = bufferevent_new(STDOUT_FILENO, NULL, NULL, stream_error,
148 	    NULL);
149 	bufferevent_enable(output_ev, EV_WRITE);
150 
151 	line_ev = bufferevent_new(line_fd, line_read, NULL, line_error,
152 	    NULL);
153 	bufferevent_enable(line_ev, EV_READ|EV_WRITE);
154 
155 	printf("Connected (speed %u)\r\n", speed);
156 	event_dispatch();
157 
158 	restore_termios();
159 	printf("\r\n[EOT]\n");
160 
161 	exit(0);
162 }
163 
164 void
165 signal_event(int fd, short events, void *data)
166 {
167 	restore_termios();
168 	printf("\r\n[SIG%s]\n", sys_signame[fd]);
169 
170 	exit(0);
171 }
172 
173 void
174 set_termios(void)
175 {
176 	struct termios tio;
177 
178 	if (!isatty(STDIN_FILENO))
179 		return;
180 
181 	memcpy(&tio, &saved_tio, sizeof(tio));
182 	tio.c_lflag &= ~(ICANON|IEXTEN|ECHO);
183 	tio.c_iflag &= ~(INPCK|ICRNL);
184 	tio.c_oflag &= ~OPOST;
185 	tio.c_cc[VMIN] = 1;
186 	tio.c_cc[VTIME] = 0;
187 	tio.c_cc[VDISCARD] = _POSIX_VDISABLE;
188 	tio.c_cc[VDSUSP] = _POSIX_VDISABLE;
189 	tio.c_cc[VINTR] = _POSIX_VDISABLE;
190 	tio.c_cc[VLNEXT] = _POSIX_VDISABLE;
191 	tio.c_cc[VQUIT] = _POSIX_VDISABLE;
192 	tio.c_cc[VSUSP] = _POSIX_VDISABLE;
193 	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &tio) != 0)
194 		cu_err(1, "tcsetattr");
195 }
196 
197 void
198 restore_termios(void)
199 {
200 	if (isatty(STDIN_FILENO))
201 		tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_tio);
202 }
203 
204 int
205 set_line(int speed)
206 {
207 	struct termios	 tio;
208 
209 	cfmakeraw(&tio);
210 	tio.c_iflag = 0;
211 	tio.c_oflag = 0;
212 	tio.c_lflag = 0;
213 	tio.c_cflag = CREAD|CS8|CLOCAL;
214 	tio.c_cc[VMIN] = 1;
215 	tio.c_cc[VTIME] = 0;
216 	cfsetspeed(&tio, speed);
217 	if (tcsetattr(line_fd, TCSAFLUSH, &tio) != 0)
218 		return (-1);
219 	return (0);
220 }
221 
222 void
223 stream_read(struct bufferevent *bufev, void *data)
224 {
225 	char	*new_data, *ptr;
226 	size_t	 new_size;
227 	int	 state_change;
228 
229 	new_data = EVBUFFER_DATA(input_ev->input);
230 	new_size = EVBUFFER_LENGTH(input_ev->input);
231 	if (new_size == 0)
232 		return;
233 
234 	state_change = isatty(STDIN_FILENO);
235 	for (ptr = new_data; ptr < new_data + new_size; ptr++) {
236 		switch (last_state) {
237 		case STATE_NONE:
238 			if (state_change && *ptr == '\r')
239 				last_state = STATE_NEWLINE;
240 			break;
241 		case STATE_NEWLINE:
242 			if (state_change && *ptr == '~') {
243 				last_state = STATE_TILDE;
244 				continue;
245 			}
246 			if (*ptr != '\r')
247 				last_state = STATE_NONE;
248 			break;
249 		case STATE_TILDE:
250 			do_command(*ptr);
251 			last_state = STATE_NEWLINE;
252 			continue;
253 		}
254 
255 		bufferevent_write(line_ev, ptr, 1);
256 	}
257 
258 	evbuffer_drain(input_ev->input, new_size);
259 }
260 
261 void
262 stream_error(struct bufferevent *bufev, short what, void *data)
263 {
264 	event_loopexit(NULL);
265 }
266 
267 void
268 line_read(struct bufferevent *bufev, void *data)
269 {
270 	char	*new_data;
271 	size_t	 new_size;
272 
273 	new_data = EVBUFFER_DATA(line_ev->input);
274 	new_size = EVBUFFER_LENGTH(line_ev->input);
275 	if (new_size == 0)
276 		return;
277 
278 	if (record_file != NULL)
279 		fwrite(new_data, 1, new_size, record_file);
280 	bufferevent_write(output_ev, new_data, new_size);
281 
282 	evbuffer_drain(line_ev->input, new_size);
283 }
284 
285 void
286 line_error(struct bufferevent *bufev, short what, void *data)
287 {
288 	event_loopexit(NULL);
289 }
290 
291 /* Expands tildes in the file name. Based on code from ssh/misc.c. */
292 char *
293 tilde_expand(const char *filename1)
294 {
295 	const char	*filename, *path;
296 	char		 user[128], ret[MAXPATHLEN], *out;
297 	struct passwd	*pw;
298 	u_int		 len, slash;
299 
300 	if (*filename1 != '~')
301 		goto no_change;
302 	filename = filename1 + 1;
303 
304 	path = strchr(filename, '/');
305 	if (path != NULL && path > filename) {		/* ~user/path */
306 		slash = path - filename;
307 		if (slash > sizeof(user) - 1)
308 			goto no_change;
309 		memcpy(user, filename, slash);
310 		user[slash] = '\0';
311 		if ((pw = getpwnam(user)) == NULL)
312 			goto no_change;
313 	} else if ((pw = getpwuid(getuid())) == NULL)	/* ~/path */
314 		goto no_change;
315 
316 	if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
317 		goto no_change;
318 
319 	/* Make sure directory has a trailing '/' */
320 	len = strlen(pw->pw_dir);
321 	if ((len == 0 || pw->pw_dir[len - 1] != '/') &&
322 	    strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
323 		goto no_change;
324 
325 	/* Skip leading '/' from specified path */
326 	if (path != NULL)
327 		filename = path + 1;
328 	if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
329 		goto no_change;
330 
331 	out = strdup(ret);
332 	if (out == NULL)
333 		cu_err(1, "strdup");
334 	return (out);
335 
336 no_change:
337 	out = strdup(filename1);
338 	if (out == NULL)
339 		cu_err(1, "strdup");
340 	return (out);
341 }
342