xref: /freebsd/usr.sbin/watch/watch.c (revision 17ee9d00bc1ae1e598c38f25826f861e4bc6c3ce)
1 /*
2  * Copyright (c) 1995 Ugen J.S.Antsilevich
3  *
4  * Redistribution and use in source forms, with and without modification,
5  * are permitted provided that this entire comment appears intact.
6  *
7  * Redistribution in binary form may occur without any restrictions.
8  * Obviously, it would be nice if you gave credit where credit is due
9  * but requiring it would be too onerous.
10  *
11  * This software is provided ``AS IS'' without any warranties of any kind.
12  *
13  * Snoop stuff.
14  */
15 
16 #include <stdio.h>
17 #include <unistd.h>
18 #include <stdlib.h>
19 #include <signal.h>
20 #include <sys/types.h>
21 #include <sys/time.h>
22 #include <sys/select.h>
23 #include <sys/fcntl.h>
24 #include <sys/ioctl.h>
25 #include <sys/ioctl_compat.h>
26 #include <sys/snoop.h>
27 
28 
29 #define MSG_INIT	"Snoop started."
30 #define MSG_OFLOW	"Snoop stopped due to overflow.Reconnecting."
31 #define MSG_CLOSED	"Snoop stopped due to tty close.Reconnecting."
32 #define MSG_CHANGE	"Snoop device change by user request."
33 
34 
35 #define DEV_NAME_LEN	12	/* for /dev/ttyXX++ */
36 #define MIN_SIZE	256
37 
38 #define CHR_SWITCH	24	/* Ctrl+X	 */
39 #define CHR_CLEAR	23	/* Ctrl+V	 */
40 
41 
42 int             opt_reconn_close = 0;
43 int             opt_reconn_oflow = 0;
44 int             opt_interactive = 1;
45 int             opt_timestamp = 0;
46 
47 char            dev_name[DEV_NAME_LEN];
48 int             snp_io;
49 struct snptty   snp_tty;
50 int             std_in = 0, std_out = 1;
51 
52 
53 int             clear_ok = 0;
54 struct sgttyb   sgo;
55 char            tbuf[1024], buf[1024];
56 
57 
58 void
59 clear()
60 {
61 	if (clear_ok)
62 		tputs(buf, 1, putchar);
63 	fflush(stdout);
64 }
65 
66 void
67 timestamp(buf)
68 	char           *buf;
69 {
70 	time_t          t;
71 	char            btmp[1024];
72 	clear();
73 	printf("\n---------------------------------------------\n");
74 	t = time(NULL);
75 	strftime(btmp, 1024, "Time: %d %b %H:%M", localtime(&t));
76 	printf("%s\n", btmp);
77 	printf("%s\n", buf);
78 	printf("---------------------------------------------\n");
79 	fflush(stdout);
80 }
81 
82 void
83 set_tty()
84 {
85 	struct sgttyb   sgn;
86 	ioctl(std_in, TIOCGETP, &sgo);
87 	/* bcopy(&sgn, &sgo, sizeof(struct sgttyb)); */
88 	sgn = sgo;
89 	sgn.sg_flags |= CBREAK;
90 	sgn.sg_flags &= ~ECHO;
91 	ioctl(std_in, TIOCSETP, &sgn);
92 }
93 
94 void
95 unset_tty()
96 {
97 	ioctl(std_in, TIOCSETP, &sgo);
98 }
99 
100 
101 void
102 fatal(buf)
103 	char           *buf;
104 {
105 	unset_tty();
106 	if (buf)
107 		fprintf(stderr, "Fatal: %s\n", buf);
108 	exit(1);
109 }
110 
111 int
112 open_snp()
113 {
114 	char            snp[DEV_NAME_LEN] = "/dev/snpX";
115 	char            c;
116 	int             f;
117 	for (c = '0'; c <= '9'; c++) {
118 		snp[8] = c;
119 		if ((f = open(snp, O_RDONLY)) < 0)
120 			continue;
121 		return f;
122 	}
123 	fatal("Cannot open snoop device.");
124 }
125 
126 
127 void
128 cleanup()
129 {
130 	if (opt_timestamp)
131 		timestamp("Logging Exited.");
132 	close(snp_io);
133 	unset_tty();
134 	exit(0);
135 }
136 
137 
138 void
139 show_usage()
140 {
141 	printf("watch -[ciot] [tty name]\n");
142 	exit(1);
143 }
144 
145 void
146 setup_scr()
147 {
148 	char           *cbuf = buf, *term;
149 	if (!opt_interactive)
150 		return;
151 	if ((term = getenv("TERM")))
152 		if (tgetent(tbuf, term) == 1)
153 			if (tgetstr("cl", &cbuf))
154 				clear_ok = 1;
155 	clear();
156 	set_tty();
157 }
158 
159 
160 int
161 ctoh(c)
162 	char            c;
163 {
164 	if (c >= '0' && c <= '9')
165 		return (int) (c - '0');
166 
167 	if (c >= 'a' && c <= 'f')
168 		return (int) (c - 'a' + 10);
169 
170 	fatal("Bad tty number.");
171 }
172 
173 
174 void
175 detach_snp()
176 {
177 	struct snptty   st;
178 	st.st_type = -1;
179 	st.st_unit = -1;
180 	ioctl(snp_io, SNPSTTY, &st);
181 }
182 
183 void
184 attach_snp()
185 {
186 	if (ioctl(snp_io, SNPSTTY, &snp_tty) != 0)
187 		fatal("Cannot attach to tty.");
188 	if (opt_timestamp)
189 		timestamp("Logging Started.");
190 }
191 
192 
193 void
194 set_dev(name)
195 	char           *name;
196 {
197 	char            buf[DEV_NAME_LEN], num[DEV_NAME_LEN];
198 	int             unitbase = 0;
199 
200 	if (strlen(name) > 5 && !strncmp(name, "/dev/", 5))
201 		strcpy(buf, &(name[5]));
202 	else
203 		strcpy(buf, name);
204 
205 	if (strlen(buf) < 4)
206 		fatal("Bad tty name.");
207 
208 	if (!strncmp(buf, "tty", 3))
209 		switch (buf[3]) {
210 		case 'v':
211 			snp_tty.st_unit = ctoh(buf[4]);
212 			snp_tty.st_type = ST_VTY;
213 			goto got_num;
214 		case 'r':
215 			unitbase += 16;
216 		case 'q':
217 			unitbase += 16;
218 		case 'p':
219 			snp_tty.st_unit = ctoh(buf[4]) + unitbase;
220 			snp_tty.st_type = ST_PTY;
221 			goto got_num;
222 		case '0':
223 		case 'd':
224 			snp_tty.st_unit = ctoh(buf[4]);
225 			snp_tty.st_type = ST_SIO;
226 			goto got_num;
227 		default:
228 			fatal("Bad tty name.");
229 
230 		}
231 
232 
233 	if (!strncmp(buf, "vty", 3)) {
234 		strcpy(num, &(buf[3]));
235 		snp_tty.st_unit = atoi(num);
236 		snp_tty.st_type = ST_VTY;
237 		goto got_num;
238 	}
239 	if (!strncmp(buf, "pty", 3)) {
240 		strcpy(num, &(buf[3]));
241 		snp_tty.st_unit = atoi(num);
242 		snp_tty.st_type = ST_PTY;
243 		goto got_num;
244 	}
245 	if (!strncmp(buf, "sio", 3) || !strncmp(buf, "cua", 3)) {
246 		strcpy(num, &(buf[3]));
247 		snp_tty.st_unit = atoi(num);
248 		snp_tty.st_type = ST_SIO;
249 		goto got_num;
250 	}
251 	fatal("Bad tty name.");
252 got_num:
253 	attach_snp();
254 }
255 
256 void
257 ask_dev(dev_name, msg)
258 	char           *dev_name, *msg;
259 {
260 	char            buf[DEV_NAME_LEN];
261 	int             len;
262 
263 	clear();
264 	unset_tty();
265 
266 	if (msg)
267 		printf("%s\n", msg);
268 	if (dev_name)
269 		printf("Enter device name [%s]:", dev_name);
270 	else
271 		printf("Enter device name:");
272 
273 	if (fgets(buf, DEV_NAME_LEN - 1, stdin)) {
274 		len = strlen(buf);
275 		if (buf[len - 1] == '\n')
276 			buf[len - 1] = '\0';
277 		if (buf[0] != '\0' && buf[0] != ' ')
278 			strcpy(dev_name, buf);
279 	}
280 	set_tty();
281 }
282 
283 
284 void
285 main(ac, av)
286 	int             ac;
287 	char          **av;
288 {
289 	int             res, nread, b_size = MIN_SIZE;
290 	extern int      optind;
291 	char            ch, *buf;
292 	fd_set          fd_s;
293 
294 	if (getuid() != 0)
295 		fatal(NULL);
296 
297 	if (isatty(std_out))
298 		opt_interactive = 1;
299 	else
300 		opt_interactive = 0;
301 
302 
303 	while ((ch = getopt(ac, av, "ciot")) != EOF)
304 		switch (ch) {
305 		case 'c':
306 			opt_reconn_close = 1;
307 			break;
308 		case 'i':
309 			opt_interactive = 1;
310 			break;
311 		case 'o':
312 			opt_reconn_oflow = 1;
313 			break;
314 		case 't':
315 			opt_timestamp = 1;
316 			break;
317 		case '?':
318 		default:
319 			show_usage();
320 			exit(1);
321 		}
322 
323 	signal(SIGINT, cleanup);
324 
325 	setup_scr();
326 	snp_io = open_snp();
327 
328 	if (*(av += optind) == NULL) {
329 		if (opt_interactive)
330 			ask_dev(dev_name, MSG_INIT);
331 		else
332 			fatal("No device name given.");
333 	} else
334 		strncpy(dev_name, *av, DEV_NAME_LEN);
335 
336 	set_dev(dev_name);
337 
338 	if (!(buf = (char *) malloc(b_size)))
339 		fatal("Cannot malloc().");
340 
341 	FD_ZERO(&fd_s);
342 
343 	while (1) {
344 		if (opt_interactive)
345 			FD_SET(std_in, &fd_s);
346 		FD_SET(snp_io, &fd_s);
347 		res = select(snp_io + 1, &fd_s, NULL, NULL, NULL);
348 		if (opt_interactive && FD_ISSET(std_in, &fd_s)) {
349 			switch (ch = getchar()) {
350 			case CHR_CLEAR:
351 				clear();
352 				break;
353 			case CHR_SWITCH:
354 				/* detach_snp(); */
355 				ask_dev(dev_name, MSG_CHANGE);
356 				set_dev(dev_name);
357 				break;
358 			default:
359 			}
360 		}
361 		if (!FD_ISSET(snp_io, &fd_s))
362 			continue;
363 
364 		if ((res = ioctl(snp_io, FIONREAD, &nread)) != 0)
365 			fatal("ioctl() failed.");
366 
367 		switch (nread) {
368 		case SNP_OFLOW:
369 			if (opt_reconn_oflow)
370 				attach_snp();
371 			else if (opt_interactive) {
372 				ask_dev(dev_name, MSG_OFLOW);
373 				set_dev(dev_name);
374 			} else
375 				cleanup();
376 		case SNP_DETACH:
377 		case SNP_TTYCLOSE:
378 			if (opt_reconn_close)
379 				attach_snp();
380 			else if (opt_interactive) {
381 				ask_dev(dev_name, MSG_CLOSED);
382 				set_dev(dev_name);
383 			} else
384 				cleanup();
385 		default:
386 			if (nread < (b_size / 2) && (b_size / 2) > MIN_SIZE) {
387 				free(buf);
388 				if (!(buf = (char *) malloc(b_size / 2)))
389 					fatal("Cannot malloc()");
390 				b_size = b_size / 2;
391 			}
392 			if (nread > b_size) {
393 				b_size = (nread % 2) ? (nread + 1) : (nread);
394 				free(buf);
395 				if (!(buf = (char *) malloc(b_size)))
396 					fatal("Cannot malloc()");
397 			}
398 			if (read(snp_io, buf, nread) < nread)
399 				fatal("read failed.");
400 			if (write(std_out, buf, nread) < nread)
401 				fatal("write failed.");
402 		}
403 	}			/* While */
404 }
405