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authorPascal Bellard <pascal.bellard@ads-lu.com>2010-06-21 02:17:29 +0200
committerDenys Vlasenko <vda.linux@googlemail.com>2010-06-21 02:17:29 +0200
commita8b594fda7cbfcc2aadf9779ee40b264eeec86b2 (patch)
tree09be4efc8b552668b1db3542549559c1f804fe53
parentd2b738a6d27ceab834c35382100948a2fdd55b44 (diff)
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conspy: new applet
Signed-off-by: Pascal Bellard <pascal.bellard@ads-lu.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat
-rw-r--r--miscutils/conspy.c472
1 files changed, 472 insertions, 0 deletions
diff --git a/miscutils/conspy.c b/miscutils/conspy.c
new file mode 100644
index 000000000..7ba7959a2
--- /dev/null
+++ b/miscutils/conspy.c
@@ -0,0 +1,472 @@
1/* vi: set sw=4 ts=4: */
2/*
3 * A text-mode VNC like program for Linux virtual terminals.
4 *
5 * pascal.bellard@ads-lu.com
6 *
7 * Based on Russell Stuart's conspy.c
8 * http://ace-host.stuart.id.au/russell/files/conspy.c
9 *
10 * Licensed under GPLv2 or later, see file License in this tarball for details.
11 *
12 * example : conspy num shared access to console num
13 * or conspy -d num screenshot of console num
14 * or conspy -cs num poor man's GNU screen like
15 */
16
17//applet:IF_CONSPY(APPLET(conspy, _BB_DIR_BIN, _BB_SUID_DROP))
18
19//kbuild:lib-$(CONFIG_CONSPY) += conspy.o
20
21//config:config CONSPY
22//config: bool "conspy"
23//config: default n
24//config: help
25//config: A text-mode VNC like program for Linux virtual terminals.
26//config: example : conspy num shared access to console num
27//config: or conspy -d num screenshot of console num
28//config: or conspy -cs num poor man's GNU screen like
29
30//usage:#define conspy_trivial_usage
31//usage: "[-vcsndf] [-x ROW] [-y LINE] [CONSOLE_NO]"
32//usage:#define conspy_full_usage "\n\n"
33//usage: "A text-mode VNC like program for Linux virtual consoles."
34//usage: "\nTo exit, quickly press ESC 3 times."
35//usage: "\n"
36//usage: "\nOptions:"
37//usage: "\n -v Don't send keystrokes to the console"
38//usage: "\n -c Create missing devices in /dev"
39//usage: "\n -s Open a SHELL session"
40//usage: "\n -n Black & white"
41//usage: "\n -d Dump console to stdout"
42//usage: "\n -f Follow cursor"
43//usage: "\n -x ROW Starting row"
44//usage: "\n -y LINE Starting line"
45
46#include "libbb.h"
47#include <sys/kd.h>
48
49struct screen_info {
50 unsigned char lines, rows, cursor_x, cursor_y;
51};
52
53#define CHAR(x) ((x)[0])
54#define ATTR(x) ((x)[1])
55#define NEXT(x) ((x)+=2)
56#define DATA(x) (* (short *) (x))
57
58struct globals {
59 char* data;
60 int size;
61 int x, y;
62 int kbd_fd;
63 unsigned width;
64 unsigned height;
65 char mask;
66 char last_attr;
67 struct screen_info info;
68 struct termios term_orig;
69};
70
71#define G (*ptr_to_globals)
72#define INIT_G() do { \
73 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
74} while (0)
75
76static void screen_read_close(int fd, char *data)
77{
78 unsigned i, j;
79
80 xread(fd, data, G.size);
81 G.last_attr = 0;
82 for (i = 0; i < G.info.lines; i++) {
83 for (j = 0; j < G.info.rows; j++, NEXT(data)) {
84 unsigned x = j - G.x; // if will catch j < G.x too
85 unsigned y = i - G.y; // if will catch i < G.y too
86
87 if (CHAR(data) < ' ')
88 CHAR(data) = ' ';
89 if (y >= G.height || x >= G.width)
90 DATA(data) = 0;
91 }
92 }
93 close(fd);
94}
95
96static void screen_char(char *data)
97{
98 if (((G.last_attr - ATTR(data)) & G.mask) != 0) {
99 // BLGCRMOW
100 static const char color[8] = "04261537";
101
102 printf("\033[%c;4%c;3%cm",
103 (ATTR(data) & 8) ? '1' // bold
104 : '0', // defaults
105 color[(ATTR(data) >> 4) & 7], color[ATTR(data) & 7]);
106 G.last_attr = ATTR(data);
107 }
108 bb_putchar(CHAR(data));
109}
110
111#define clrscr() printf("\033[1;1H" "\033[0J")
112#define curoff() printf("\033[?25l")
113
114static void curon(void)
115{
116 printf("\033[?25h");
117}
118
119static void gotoxy(int row, int line)
120{
121 printf("\033[%u;%uH", line + 1, row + 1);
122}
123
124static void screen_dump(char *data)
125{
126 int space, linefeed, line, row;
127 int linecnt = G.info.lines - G.y;
128
129 data += 2 * G.y * G.info.rows;
130 for (linefeed = line = 0; line < linecnt && line < G.height; line++) {
131 for (space = row = 0; row < G.info.rows; row++, NEXT(data)) {
132 unsigned tty_row = row - G.x; // if will catch row < G.x too
133
134 if (tty_row >= G.width)
135 continue;
136 space++;
137 if (((G.last_attr - ATTR(data)) & G.mask) && CHAR(data) == ' ')
138 continue;
139 while (linefeed != 0) {
140 bb_putchar('\r');
141 bb_putchar('\n');
142 linefeed--;
143 }
144 while (--space)
145 bb_putchar(' ');
146 screen_char(data);
147 }
148 linefeed++;
149 }
150}
151
152static void curmove(void)
153{
154 unsigned cx = G.info.cursor_x - G.x;
155 unsigned cy = G.info.cursor_y - G.y;
156
157 if (cx >= G.width || cy >= G.height) {
158 curoff();
159 } else {
160 curon();
161 gotoxy(cx, cy);
162 }
163 fflush_all();
164}
165
166static void cleanup(int code)
167{
168 curon();
169 fflush_all();
170 tcsetattr(G.kbd_fd, TCSANOW, &G.term_orig);
171 if (ENABLE_FEATURE_CLEAN_UP) {
172 free(ptr_to_globals);
173 close(G.kbd_fd);
174 }
175 // Reset attributes
176 if (G.mask != 0)
177 printf("\033[0m");
178 bb_putchar('\n');
179 if (code > 1)
180 kill_myself_with_sig(code); // does not return
181 exit(code);
182}
183
184static void get_initial_data(const char* vcsa_name)
185{
186 int size;
187 int fd = xopen(vcsa_name, O_RDONLY);
188 xread(fd, &G.info, 4);
189 G.size = size = G.info.rows * G.info.lines * 2;
190 G.width = G.height = UINT_MAX;
191 G.data = xzalloc(2 * size);
192 screen_read_close(fd, G.data);
193}
194
195static void create_cdev_if_doesnt_exist(const char* name, dev_t dev)
196{
197 int fd = open(name, O_RDONLY);
198 if (fd != -1)
199 close(fd);
200 else if (errno == ENOENT)
201 mknod(name, S_IFCHR | 0660, dev);
202}
203
204static NOINLINE void start_shell_in_child(const char* tty_name)
205{
206 int pid = vfork();
207 if (pid < 0) {
208 bb_perror_msg_and_die("vfork");
209 }
210 if (pid == 0) {
211 struct termios termchild;
212 char *shell = getenv("SHELL");
213
214 if (!shell)
215 shell = (char *) DEFAULT_SHELL;
216 signal(SIGHUP, SIG_IGN);
217 // set tty as a controlling tty
218 setsid();
219 // make tty to be input, output, error
220 close(0);
221 xopen(tty_name, O_RDWR); // uses fd 0
222 xdup2(0, 1);
223 xdup2(0, 2);
224 ioctl(0, TIOCSCTTY, 1);
225 tcsetpgrp(0, getpid());
226 tcgetattr(0, &termchild);
227 termchild.c_lflag |= ECHO;
228 termchild.c_oflag |= ONLCR | XTABS;
229 termchild.c_iflag |= ICRNL;
230 termchild.c_iflag &= ~IXOFF;
231 tcsetattr_stdin_TCSANOW(&termchild);
232 execl(shell, shell, "-i", (char *) NULL);
233 bb_simple_perror_msg_and_die(shell);
234 }
235}
236
237enum {
238 FLAG_v, // view only
239 FLAG_c, // create device if need
240 FLAG_s, // session
241 FLAG_n, // no colors
242 FLAG_d, // dump screen
243 FLAG_f, // follow cursor
244};
245#define FLAG(x) (1 << FLAG_##x)
246
247int conspy_main(int argc UNUSED_PARAM, char **argv) MAIN_EXTERNALLY_VISIBLE;
248int conspy_main(int argc UNUSED_PARAM, char **argv)
249{
250 char *buffer[2];
251 char vcsa_name[sizeof("/dev/vcsa") + 2];
252 char tty_name[sizeof("/dev/tty") + 2];
253#define keybuf bb_common_bufsiz1
254 struct termios termbuf;
255 unsigned opts;
256 unsigned ttynum;
257 int poll_timeout_ms;
258 int current;
259 int ioerror_count;
260 int key_count;
261 int escape_count;
262 int nokeys;
263#if ENABLE_LONG_OPTS
264 static const char getopt_longopts[] ALIGN1 =
265 "viewonly\0" No_argument "v"
266 "createdevice\0" No_argument "c"
267 "session\0" No_argument "s"
268 "nocolors\0" No_argument "n"
269 "dump\0" No_argument "d"
270 "follow\0" No_argument "f"
271 ;
272
273 applet_long_options = getopt_longopts;
274#endif
275 INIT_G();
276 strcpy(vcsa_name, "/dev/vcsa");
277
278 opt_complementary = "x+:y+"; // numeric params
279 opts = getopt32(argv, "vcsndfx:y:", &G.x, &G.y);
280 argv += optind;
281 ttynum = 0;
282 if (argv[0]) {
283 ttynum = xatou_range(argv[0], 0, 63);
284 sprintf(vcsa_name + sizeof("/dev/vcsa")-1, "%u", ttynum);
285 }
286 sprintf(tty_name, "%s%u", "/dev/tty", ttynum);
287 if (!(opts & FLAG(n)))
288 G.mask = 0xff;
289 if (opts & FLAG(c)) {
290 if ((opts & (FLAG(s)|FLAG(v))) != FLAG(v))
291 create_cdev_if_doesnt_exist(tty_name, makedev(4, ttynum));
292 create_cdev_if_doesnt_exist(vcsa_name, makedev(7, 128 + ttynum));
293 }
294 if ((opts & FLAG(s)) && ttynum) {
295 start_shell_in_child(tty_name);
296 }
297
298 get_initial_data(vcsa_name);
299 G.kbd_fd = xopen(CURRENT_TTY, O_RDONLY);
300 if (opts & FLAG(d)) {
301 screen_dump(G.data);
302 bb_putchar('\n');
303 if (ENABLE_FEATURE_CLEAN_UP) {
304 free(ptr_to_globals);
305 close(G.kbd_fd);
306 }
307 return 0;
308 }
309
310 bb_signals(BB_FATAL_SIGS, cleanup);
311 // All characters must be passed through to us unaltered
312 tcgetattr(G.kbd_fd, &G.term_orig);
313 termbuf = G.term_orig;
314 termbuf.c_iflag &= ~(BRKINT|INLCR|ICRNL|IXON|IXOFF|IUCLC|IXANY|IMAXBEL);
315 termbuf.c_oflag &= ~(OPOST);
316 termbuf.c_lflag &= ~(ISIG|ICANON|ECHO);
317 termbuf.c_cc[VMIN] = 1;
318 termbuf.c_cc[VTIME] = 0;
319 tcsetattr(G.kbd_fd, TCSANOW, &termbuf);
320 buffer[0] = G.data;
321 buffer[1] = G.data + G.size;
322 poll_timeout_ms = 250;
323 ioerror_count = key_count = escape_count = nokeys = current = 0;
324 while (1) {
325 struct pollfd pfd;
326 int vcsa_handle;
327 int bytes_read;
328 int i, j;
329 int next = 1 - current;
330 char *data = buffer[next];
331 char *old = buffer[current];
332
333 // Close & re-open vcsa in case they have
334 // swapped virtual consoles
335 vcsa_handle = xopen(vcsa_name, O_RDONLY);
336 xread(vcsa_handle, &G.info, 4);
337 if (G.size != (G.info.rows * G.info.lines * 2)) {
338 cleanup(1);
339 }
340 i = G.width;
341 j = G.height;
342 get_terminal_width_height(G.kbd_fd, &G.width, &G.height);
343 if ((option_mask32 & FLAG(f))) {
344 int nx = G.info.cursor_x - G.width + 1;
345 int ny = G.info.cursor_y - G.height + 1;
346
347 if (G.info.cursor_x < G.x) {
348 G.x = G.info.cursor_x;
349 i = 0; // force refresh
350 }
351 if (nx > G.x) {
352 G.x = nx;
353 i = 0; // force refresh
354 }
355 if (G.info.cursor_y < G.y) {
356 G.y = G.info.cursor_y;
357 i = 0; // force refresh
358 }
359 if (ny > G.y) {
360 G.y = ny;
361 i = 0; // force refresh
362 }
363 }
364
365 // Scan console data and redraw our tty where needed
366 screen_read_close(vcsa_handle, data);
367 if (i != G.width || j != G.height) {
368 clrscr();
369 screen_dump(data);
370 }
371 else for (i = 0; i < G.info.lines; i++) {
372 char *last = last;
373 char *first = NULL;
374 int iy = i - G.y;
375
376 if (iy >= (int) G.height)
377 break;
378 for (j = 0; j < G.info.rows; j++) {
379 last = data;
380 if (DATA(data) != DATA(old) && iy >= 0) {
381 unsigned jx = j - G.x;
382
383 last = NULL;
384 if (first == NULL && jx < G.width) {
385 first = data;
386 gotoxy(jx, iy);
387 }
388 }
389 NEXT(old);
390 NEXT(data);
391 }
392 if (first == NULL)
393 continue;
394 if (last == NULL)
395 last = data;
396
397 // Write the data to the screen
398 for (; first < last; NEXT(first))
399 screen_char(first);
400 }
401 current = next;
402 curmove();
403
404 // Wait for local user keypresses
405 pfd.fd = G.kbd_fd;
406 pfd.events = POLLIN;
407 bytes_read = 0;
408 switch (poll(&pfd, 1, poll_timeout_ms)) {
409 case -1:
410 if (errno != EINTR)
411 cleanup(1);
412 break;
413 case 0:
414 if (++nokeys >= 4)
415 nokeys = escape_count = 0;
416 break;
417 default:
418 // Read the keys pressed
419 bytes_read = read(G.kbd_fd, keybuf + key_count,
420 sizeof(keybuf) - key_count);
421 if (bytes_read < 0)
422 cleanup(1);
423
424 // Do exit processing
425 for (i = 0; i < bytes_read; i++) {
426 if (keybuf[key_count + i] != '\033')
427 escape_count = 0;
428 else if (++escape_count >= 3)
429 cleanup(0);
430 }
431 }
432 poll_timeout_ms = 250;
433
434 // Insert all keys pressed into the virtual console's input
435 // buffer. Don't do this if the virtual console is in scan
436 // code mode - giving ASCII characters to a program expecting
437 // scan codes will confuse it.
438 if (!(option_mask32 & FLAG(v)) && escape_count == 0) {
439 int handle, result;
440 long kbd_mode;
441
442 key_count += bytes_read;
443 handle = xopen(tty_name, O_WRONLY);
444 result = ioctl(handle, KDGKBMODE, &kbd_mode);
445 if (result == -1)
446 /* nothing */;
447 else if (kbd_mode != K_XLATE && kbd_mode != K_UNICODE)
448 key_count = 0; // scan code mode
449 else {
450 for (i = 0; i < key_count && result != -1; i++)
451 result = ioctl(handle, TIOCSTI, keybuf + i);
452 key_count -= i;
453 if (key_count)
454 memmove(keybuf, keybuf + i, key_count);
455 // If there is an application on console which reacts
456 // to keypresses, we need to make our first sleep
457 // shorter to quickly redraw whatever it printed there.
458 poll_timeout_ms = 20;
459 }
460 // Close & re-open tty in case they have
461 // swapped virtual consoles
462 close(handle);
463
464 // We sometimes get spurious IO errors on the TTY
465 // as programs close and re-open it
466 if (result != -1)
467 ioerror_count = 0;
468 else if (errno != EIO || ++ioerror_count > 4)
469 cleanup(1);
470 }
471 }
472}
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