summaryrefslogtreecommitdiffstats
path: root/usr.sbin/watch/watch.c
blob: 388614e08c18618189b2ac2b6a6bef53ffc40ac2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
/*
 * Copyright (c) 1995 Ugen J.S.Antsilevich
 *
 * Redistribution and use in source forms, with and without modification,
 * are permitted provided that this entire comment appears intact.
 *
 * Redistribution in binary form may occur without any restrictions.
 * Obviously, it would be nice if you gave credit where credit is due
 * but requiring it would be too onerous.
 *
 * This software is provided ``AS IS'' without any warranties of any kind.
 *
 * Snoop stuff.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/fcntl.h>
#include <sys/filio.h>
#include <sys/snoop.h>
#include <sys/stat.h>
#include <sys/linker.h>
#include <sys/module.h>

#include <err.h>
#include <errno.h>
#include <locale.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <termcap.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>

#define MSG_INIT	"Snoop started."
#define MSG_OFLOW	"Snoop stopped due to overflow. Reconnecting."
#define MSG_CLOSED	"Snoop stopped due to tty close. Reconnecting."
#define MSG_CHANGE	"Snoop device change by user request."
#define MSG_NOWRITE	"Snoop device change due to write failure."


#define DEV_NAME_LEN	1024	/* for /dev/ttyXX++ */
#define MIN_SIZE	256

#define CHR_SWITCH	24	/* Ctrl+X	 */
#define CHR_CLEAR	23	/* Ctrl+V	 */

static void	clear(void);
static void	timestamp(const char *);
static void	set_tty(void);
static void	unset_tty(void);
static void	fatal(int, const char *);
static int	open_snp(void);
static void	cleanup(int);
static void	usage(void) __dead2;
static void	setup_scr(void);
static void	attach_snp(void);
static void	detach_snp(void);
static void	set_dev(const char *);
static void	ask_dev(char *, const char *);

int             opt_reconn_close = 0;
int             opt_reconn_oflow = 0;
int             opt_interactive = 1;
int             opt_timestamp = 0;
int		opt_write = 0;
int		opt_no_switch = 0;
const char	*opt_snpdev;

char            dev_name[DEV_NAME_LEN];
int             snp_io;
int             std_in = 0, std_out = 1;


int             clear_ok = 0;
struct termios  otty;
char            tbuf[1024], gbuf[1024];


static void
clear(void)
{
	if (clear_ok)
		tputs(gbuf, 1, putchar);
	fflush(stdout);
}

static void
timestamp(const char *buf)
{
	time_t          t;
	char            btmp[1024];
	clear();
	printf("\n---------------------------------------------\n");
	t = time(NULL);
	strftime(btmp, 1024, "Time: %d %b %H:%M", localtime(&t));
	printf("%s\n", btmp);
	printf("%s\n", buf);
	printf("---------------------------------------------\n");
	fflush(stdout);
}

static void
set_tty(void)
{
	struct termios  ntty;

	tcgetattr (std_in, &otty);
	ntty = otty;
	ntty.c_lflag &= ~ICANON;    /* disable canonical operation  */
	ntty.c_lflag &= ~ECHO;
#ifdef FLUSHO
	ntty.c_lflag &= ~FLUSHO;
#endif
#ifdef PENDIN
	ntty.c_lflag &= ~PENDIN;
#endif
#ifdef IEXTEN
	ntty.c_lflag &= ~IEXTEN;
#endif
	ntty.c_cc[VMIN] = 1;        /* minimum of one character */
	ntty.c_cc[VTIME] = 0;       /* timeout value        */

	ntty.c_cc[VINTR] = 07;   /* ^G */
	ntty.c_cc[VQUIT] = 07;   /* ^G */
	tcsetattr (std_in, TCSANOW, &ntty);
}

static void
unset_tty(void)
{
	tcsetattr (std_in, TCSANOW, &otty);
}


static void
fatal(int error, const char *buf)
{
	unset_tty();
	if (buf)
		errx(error, "fatal: %s", buf);
	else
		exit(error);
}

static int
open_snp(void)
{
	int		f, mode;

	if (opt_write)
		mode = O_RDWR;
	else
		mode = O_RDONLY;

	if (opt_snpdev == NULL)
		f = open(_PATH_DEV "snp", mode);
	else
		f = open(opt_snpdev, mode);
	if (f == -1)
		fatal(EX_OSFILE, "cannot open snoop device");

	return (f);
}


static void
cleanup(int signo __unused)
{
	if (opt_timestamp)
		timestamp("Logging Exited.");
	close(snp_io);
	unset_tty();
	exit(EX_OK);
}


static void
usage(void)
{
	fprintf(stderr, "usage: watch [-ciotnW] [tty name]\n");
	exit(EX_USAGE);
}

static void
setup_scr(void)
{
	char           *cbuf = gbuf, *term;
	if (!opt_interactive)
		return;
	if ((term = getenv("TERM")))
		if (tgetent(tbuf, term) == 1)
			if (tgetstr("cl", &cbuf))
				clear_ok = 1;
	set_tty();
	clear();
}

static void
detach_snp(void)
{
	int		fd;

	fd = -1;
	ioctl(snp_io, SNPSTTY, &fd);
}

static void
attach_snp(void)
{
	int		snp_tty;

	snp_tty = open(dev_name, O_RDONLY | O_NONBLOCK);
	if (snp_tty < 0)
		fatal(EX_DATAERR, "can't open device");
	if (ioctl(snp_io, SNPSTTY, &snp_tty) != 0)
		fatal(EX_UNAVAILABLE, "cannot attach to tty");
	close(snp_tty);
	if (opt_timestamp)
		timestamp("Logging Started.");
}


static void
set_dev(const char *name)
{
	char            buf[DEV_NAME_LEN];
	struct stat	sb;

	if (strlen(name) > 5 && !strncmp(name, _PATH_DEV, sizeof _PATH_DEV - 1)) {
		snprintf(buf, sizeof buf, "%s", name);
	} else {
		if (strlen(name) == 2)
			sprintf(buf, "%s%s", _PATH_TTY, name);
		else
			sprintf(buf, "%s%s", _PATH_DEV, name);
	}

	if (*name == '\0' || stat(buf, &sb) < 0)
		fatal(EX_DATAERR, "bad device name");

	if ((sb.st_mode & S_IFMT) != S_IFCHR)
		fatal(EX_DATAERR, "must be a character device");

	strncpy(dev_name, buf, DEV_NAME_LEN);

	attach_snp();
}

void
ask_dev(char *dbuf, const char *msg)
{
	char            buf[DEV_NAME_LEN];
	int             len;

	clear();
	unset_tty();

	if (msg)
		printf("%s\n", msg);
	if (dbuf)
		printf("Enter device name [%s]:", dbuf);
	else
		printf("Enter device name:");

	if (fgets(buf, DEV_NAME_LEN - 1, stdin)) {
		len = strlen(buf);
		if (buf[len - 1] == '\n')
			buf[len - 1] = '\0';
		if (buf[0] != '\0' && buf[0] != ' ')
			strcpy(dbuf, buf);
	}
	set_tty();
}

#define READB_LEN	5

int
main(int ac, char *av[])
{
	int             ch, res, rv, nread;
	size_t		b_size = MIN_SIZE;
	char            *buf, chb[READB_LEN];
	fd_set          fd_s;

	(void) setlocale(LC_TIME, "");

	if (isatty(std_out))
		opt_interactive = 1;
	else
		opt_interactive = 0;


	while ((ch = getopt(ac, av, "Wciotnf:")) != -1)
		switch (ch) {
		case 'W':
			opt_write = 1;
			break;
		case 'c':
			opt_reconn_close = 1;
			break;
		case 'i':
			opt_interactive = 1;
			break;
		case 'o':
			opt_reconn_oflow = 1;
			break;
		case 't':
			opt_timestamp = 1;
			break;
		case 'n':
			opt_no_switch = 1;
			break;
		case 'f':
			opt_snpdev = optarg;
			break;
		case '?':
		default:
			usage();
		}

	if (modfind("snp") == -1)
		if (kldload("snp") == -1 || modfind("snp") == -1)
			warn("snp module not available");

	signal(SIGINT, cleanup);

	snp_io = open_snp();
	setup_scr();

	if (*(av += optind) == NULL) {
		if (opt_interactive && !opt_no_switch)
			ask_dev(dev_name, MSG_INIT);
		else
			fatal(EX_DATAERR, "no device name given");
	} else
		strncpy(dev_name, *av, DEV_NAME_LEN);

	set_dev(dev_name);

	if (!(buf = (char *) malloc(b_size)))
		fatal(EX_UNAVAILABLE, "malloc failed");

	FD_ZERO(&fd_s);

	while (1) {
		if (opt_interactive)
			FD_SET(std_in, &fd_s);
		FD_SET(snp_io, &fd_s);
		res = select(snp_io + 1, &fd_s, NULL, NULL, NULL);
		if (opt_interactive && FD_ISSET(std_in, &fd_s)) {

			if ((res = ioctl(std_in, FIONREAD, &nread)) != 0)
				fatal(EX_OSERR, "ioctl(FIONREAD)");
			if (nread > READB_LEN)
				nread = READB_LEN;
			rv = read(std_in, chb, nread);
			if (rv == -1 || rv != nread)
				fatal(EX_IOERR, "read (stdin) failed");

			switch (chb[0]) {
			case CHR_CLEAR:
				clear();
				break;
			case CHR_SWITCH:
				if (!opt_no_switch) {
					detach_snp();
					ask_dev(dev_name, MSG_CHANGE);
					set_dev(dev_name);
					break;
				}
			default:
				if (opt_write) {
					rv = write(snp_io, chb, nread);
					if (rv == -1 || rv != nread) {
						detach_snp();
						if (opt_no_switch)
							fatal(EX_IOERR,
							  "write failed");
						ask_dev(dev_name, MSG_NOWRITE);
						set_dev(dev_name);
					}
				}

			}
		}
		if (!FD_ISSET(snp_io, &fd_s))
			continue;

		if ((res = ioctl(snp_io, FIONREAD, &nread)) != 0)
			fatal(EX_OSERR, "ioctl(FIONREAD)");

		switch (nread) {
		case SNP_OFLOW:
			if (opt_reconn_oflow)
				attach_snp();
			else if (opt_interactive && !opt_no_switch) {
				ask_dev(dev_name, MSG_OFLOW);
				set_dev(dev_name);
			} else
				cleanup(-1);
			break;
		case SNP_DETACH:
		case SNP_TTYCLOSE:
			if (opt_reconn_close)
				attach_snp();
			else if (opt_interactive && !opt_no_switch) {
				ask_dev(dev_name, MSG_CLOSED);
				set_dev(dev_name);
			} else
				cleanup(-1);
			break;
		default:
			if (nread < (b_size / 2) && (b_size / 2) > MIN_SIZE) {
				free(buf);
				if (!(buf = (char *) malloc(b_size / 2)))
					fatal(EX_UNAVAILABLE, "malloc failed");
				b_size = b_size / 2;
			}
			if (nread > b_size) {
				b_size = (nread % 2) ? (nread + 1) : (nread);
				free(buf);
				if (!(buf = (char *) malloc(b_size)))
					fatal(EX_UNAVAILABLE, "malloc failed");
			}
			rv = read(snp_io, buf, nread);
			if (rv == -1 || rv != nread)
				fatal(EX_IOERR, "read failed");
			rv = write(std_out, buf, nread);
			if (rv == -1 || rv != nread)
				fatal(EX_IOERR, "write failed");
		}
	}			/* While */
	return(0);
}

OpenPOWER on IntegriCloud