Contents of /trunk/mkinitrd-magellan/busybox/miscutils/conspy.c
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Wed Aug 18 21:56:57 2010 UTC (13 years, 10 months ago) by niro
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Wed Aug 18 21:56:57 2010 UTC (13 years, 10 months ago) by niro
File MIME type: text/plain
File size: 13526 byte(s)
-updated to busybox-1.17.1
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 | |
13 | //applet:IF_CONSPY(APPLET(conspy, _BB_DIR_BIN, _BB_SUID_DROP)) |
14 | |
15 | //kbuild:lib-$(CONFIG_CONSPY) += conspy.o |
16 | |
17 | //config:config CONSPY |
18 | //config: bool "conspy" |
19 | //config: default n |
20 | //config: help |
21 | //config: A text-mode VNC like program for Linux virtual terminals. |
22 | //config: example: conspy NUM shared access to console num |
23 | //config: or conspy -nd NUM screenshot of console num |
24 | //config: or conspy -cs NUM poor man's GNU screen like |
25 | |
26 | //usage:#define conspy_trivial_usage |
27 | //usage: "[-vcsndf] [-x COL] [-y LINE] [CONSOLE_NO]" |
28 | //usage:#define conspy_full_usage "\n\n" |
29 | //usage: "A text-mode VNC like program for Linux virtual consoles." |
30 | //usage: "\nTo exit, quickly press ESC 3 times." |
31 | //usage: "\n" |
32 | //usage: "\nOptions:" |
33 | //usage: "\n -v Don't send keystrokes to the console" |
34 | //usage: "\n -c Create missing devices in /dev" |
35 | //usage: "\n -s Open a SHELL session" |
36 | //usage: "\n -n Black & white" |
37 | //usage: "\n -d Dump console to stdout" |
38 | //usage: "\n -f Follow cursor" |
39 | //usage: "\n -x COL Starting column" |
40 | //usage: "\n -y LINE Starting line" |
41 | |
42 | #include "libbb.h" |
43 | #include <sys/kd.h> |
44 | |
45 | struct screen_info { |
46 | unsigned char lines, cols, cursor_x, cursor_y; |
47 | }; |
48 | |
49 | #define CHAR(x) (*(uint8_t*)(x)) |
50 | #define ATTR(x) (((uint8_t*)(x))[1]) |
51 | #define NEXT(x) ((x) += 2) |
52 | #define DATA(x) (*(uint16_t*)(x)) |
53 | |
54 | struct globals { |
55 | char* data; |
56 | int size; |
57 | int x, y; |
58 | int kbd_fd; |
59 | int ioerror_count; |
60 | int key_count; |
61 | int escape_count; |
62 | int nokeys; |
63 | int current; |
64 | int first_line_offset; |
65 | int last_attr; |
66 | // cached local tty parameters |
67 | unsigned width; |
68 | unsigned height; |
69 | unsigned col; |
70 | unsigned line; |
71 | smallint curoff; // unknown:0 cursor on:-1 cursor off:1 |
72 | char attrbuf[sizeof("\033[0;1;5;30;40m")]; |
73 | // remote console |
74 | struct screen_info remote; |
75 | // saved local tty terminfo |
76 | struct termios term_orig; |
77 | char vcsa_name[sizeof("/dev/vcsaNN")]; |
78 | }; |
79 | |
80 | #define G (*ptr_to_globals) |
81 | #define INIT_G() do { \ |
82 | SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \ |
83 | G.attrbuf[0] = '\033'; \ |
84 | G.attrbuf[1] = '['; \ |
85 | G.width = G.height = UINT_MAX; \ |
86 | G.last_attr--; \ |
87 | } while (0) |
88 | |
89 | enum { |
90 | FLAG_v, // view only |
91 | FLAG_c, // create device if need |
92 | FLAG_s, // session |
93 | FLAG_n, // no colors |
94 | FLAG_d, // dump screen |
95 | FLAG_f, // follow cursor |
96 | }; |
97 | #define FLAG(x) (1 << FLAG_##x) |
98 | #define BW (option_mask32 & FLAG(n)) |
99 | |
100 | static void clrscr(void) |
101 | { |
102 | // Home, clear till end of screen |
103 | fputs("\033[1;1H" "\033[J", stdout); |
104 | G.col = G.line = 0; |
105 | } |
106 | |
107 | static void set_cursor(int state) |
108 | { |
109 | if (G.curoff != state) { |
110 | G.curoff = state; |
111 | fputs("\033[?25", stdout); |
112 | bb_putchar("h?l"[1 + state]); |
113 | } |
114 | } |
115 | |
116 | static void gotoxy(int col, int line) |
117 | { |
118 | if (G.col != col || G.line != line) { |
119 | G.col = col; |
120 | G.line = line; |
121 | printf("\033[%u;%uH", line + 1, col + 1); |
122 | } |
123 | } |
124 | |
125 | static void cleanup(int code) |
126 | { |
127 | set_cursor(-1); // cursor on |
128 | tcsetattr(G.kbd_fd, TCSANOW, &G.term_orig); |
129 | if (ENABLE_FEATURE_CLEAN_UP) { |
130 | close(G.kbd_fd); |
131 | } |
132 | // Reset attributes |
133 | if (!BW) |
134 | fputs("\033[0m", stdout); |
135 | bb_putchar('\n'); |
136 | if (code > 1) |
137 | kill_myself_with_sig(code); |
138 | exit(code); |
139 | } |
140 | |
141 | static void screen_read_close(void) |
142 | { |
143 | unsigned i, j; |
144 | int vcsa_fd; |
145 | char *data; |
146 | |
147 | // Close & re-open vcsa in case they have swapped virtual consoles |
148 | vcsa_fd = xopen(G.vcsa_name, O_RDONLY); |
149 | xread(vcsa_fd, &G.remote, 4); |
150 | i = G.remote.cols * 2; |
151 | G.first_line_offset = G.y * i; |
152 | i *= G.remote.lines; |
153 | if (G.data == NULL) { |
154 | G.size = i; |
155 | G.data = xzalloc(2 * i); |
156 | } |
157 | else if (G.size != i) { |
158 | cleanup(1); |
159 | } |
160 | data = G.data + G.current; |
161 | xread(vcsa_fd, data, G.size); |
162 | close(vcsa_fd); |
163 | for (i = 0; i < G.remote.lines; i++) { |
164 | for (j = 0; j < G.remote.cols; j++, NEXT(data)) { |
165 | unsigned x = j - G.x; // if will catch j < G.x too |
166 | unsigned y = i - G.y; // if will catch i < G.y too |
167 | |
168 | if (CHAR(data) < ' ') |
169 | CHAR(data) = ' '; |
170 | if (y >= G.height || x >= G.width) |
171 | DATA(data) = 0; |
172 | } |
173 | } |
174 | } |
175 | |
176 | static void screen_char(char *data) |
177 | { |
178 | if (!BW) { |
179 | uint8_t attr = ATTR(data); |
180 | //uint8_t attr = ATTR(data) >> 1; // for framebuffer console |
181 | uint8_t attr_diff = G.last_attr ^ attr; |
182 | |
183 | if (attr_diff) { |
184 | // Attribute layout for VGA compatible text videobuffer: |
185 | // blinking text |
186 | // |red bkgd |
187 | // ||green bkgd |
188 | // |||blue bkgd |
189 | // vvvv |
190 | // 00000000 <- lsb bit on the right |
191 | // bold text / text 8th bit |
192 | // red text |
193 | // green text |
194 | // blue text |
195 | // TODO: apparently framebuffer-based console uses different layout |
196 | // (bug? attempt to get 8th text bit in better position?) |
197 | // red bkgd |
198 | // |green bkgd |
199 | // ||blue bkgd |
200 | // vvv |
201 | // 00000000 <- lsb bit on the right |
202 | // bold text |
203 | // red text |
204 | // green text |
205 | // blue text |
206 | // text 8th bit |
207 | // converting RGB color bit triad to BGR: |
208 | static const char color[8] = "04261537"; |
209 | const uint8_t fg_mask = 0x07, bold_mask = 0x08; |
210 | const uint8_t bg_mask = 0x70, blink_mask = 0x80; |
211 | char *ptr; |
212 | |
213 | ptr = G.attrbuf + 2; // skip "ESC [" |
214 | |
215 | // (G.last_attr & ~attr) has 1 only where |
216 | // G.last_attr has 1 but attr has 0. |
217 | // Here we check whether we have transition |
218 | // bold->non-bold or blink->non-blink: |
219 | if (G.last_attr < 0 // initial value |
220 | || ((G.last_attr & ~attr) & (bold_mask | blink_mask)) != 0 |
221 | ) { |
222 | *ptr++ = '0'; // "reset all attrs" |
223 | *ptr++ = ';'; |
224 | // must set fg & bg, maybe need to set bold or blink: |
225 | attr_diff = attr | ~(bold_mask | blink_mask); |
226 | } |
227 | G.last_attr = attr; |
228 | if (attr_diff & bold_mask) { |
229 | *ptr++ = '1'; |
230 | *ptr++ = ';'; |
231 | } |
232 | if (attr_diff & blink_mask) { |
233 | *ptr++ = '5'; |
234 | *ptr++ = ';'; |
235 | } |
236 | if (attr_diff & fg_mask) { |
237 | *ptr++ = '3'; |
238 | *ptr++ = color[attr & fg_mask]; |
239 | *ptr++ = ';'; |
240 | } |
241 | if (attr_diff & bg_mask) { |
242 | *ptr++ = '4'; |
243 | *ptr++ = color[(attr & bg_mask) >> 4]; |
244 | *ptr++ = ';'; |
245 | } |
246 | if (ptr != G.attrbuf + 2) { |
247 | ptr[-1] = 'm'; |
248 | *ptr = '\0'; |
249 | fputs(G.attrbuf, stdout); |
250 | } |
251 | } |
252 | } |
253 | putchar(CHAR(data)); |
254 | G.col++; |
255 | } |
256 | |
257 | static void screen_dump(void) |
258 | { |
259 | int linefeed_cnt; |
260 | int line, col; |
261 | int linecnt = G.remote.lines - G.y; |
262 | char *data = G.data + G.current + G.first_line_offset; |
263 | |
264 | linefeed_cnt = 0; |
265 | for (line = 0; line < linecnt && line < G.height; line++) { |
266 | int space_cnt = 0; |
267 | for (col = 0; col < G.remote.cols; col++, NEXT(data)) { |
268 | unsigned tty_col = col - G.x; // if will catch col < G.x too |
269 | |
270 | if (tty_col >= G.width) |
271 | continue; |
272 | space_cnt++; |
273 | if (BW && CHAR(data) == ' ') |
274 | continue; |
275 | while (linefeed_cnt != 0) { |
276 | //bb_putchar('\r'); - tty driver does it for us |
277 | bb_putchar('\n'); |
278 | linefeed_cnt--; |
279 | } |
280 | while (--space_cnt) |
281 | bb_putchar(' '); |
282 | screen_char(data); |
283 | } |
284 | linefeed_cnt++; |
285 | } |
286 | } |
287 | |
288 | static void curmove(void) |
289 | { |
290 | unsigned cx = G.remote.cursor_x - G.x; |
291 | unsigned cy = G.remote.cursor_y - G.y; |
292 | int cursor = 1; |
293 | |
294 | if (cx < G.width && cy < G.height) { |
295 | gotoxy(cx, cy); |
296 | cursor = -1; |
297 | } |
298 | set_cursor(cursor); |
299 | } |
300 | |
301 | static void create_cdev_if_doesnt_exist(const char* name, dev_t dev) |
302 | { |
303 | int fd = open(name, O_RDONLY); |
304 | if (fd != -1) |
305 | close(fd); |
306 | else if (errno == ENOENT) |
307 | mknod(name, S_IFCHR | 0660, dev); |
308 | } |
309 | |
310 | static NOINLINE void start_shell_in_child(const char* tty_name) |
311 | { |
312 | int pid = xvfork(); |
313 | if (pid == 0) { |
314 | struct termios termchild; |
315 | char *shell = getenv("SHELL"); |
316 | |
317 | if (!shell) |
318 | shell = (char *) DEFAULT_SHELL; |
319 | signal(SIGHUP, SIG_IGN); |
320 | // set tty as a controlling tty |
321 | setsid(); |
322 | // make tty to be input, output, error |
323 | close(0); |
324 | xopen(tty_name, O_RDWR); // uses fd 0 |
325 | xdup2(0, 1); |
326 | xdup2(0, 2); |
327 | ioctl(0, TIOCSCTTY, 1); |
328 | tcsetpgrp(0, getpid()); |
329 | tcgetattr(0, &termchild); |
330 | termchild.c_lflag |= ECHO; |
331 | termchild.c_oflag |= ONLCR | XTABS; |
332 | termchild.c_iflag |= ICRNL; |
333 | termchild.c_iflag &= ~IXOFF; |
334 | tcsetattr_stdin_TCSANOW(&termchild); |
335 | execl(shell, shell, "-i", (char *) NULL); |
336 | bb_simple_perror_msg_and_die(shell); |
337 | } |
338 | } |
339 | |
340 | int conspy_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
341 | int conspy_main(int argc UNUSED_PARAM, char **argv) |
342 | { |
343 | char tty_name[sizeof("/dev/ttyNN")]; |
344 | #define keybuf bb_common_bufsiz1 |
345 | struct termios termbuf; |
346 | unsigned opts; |
347 | unsigned ttynum; |
348 | int poll_timeout_ms; |
349 | #if ENABLE_LONG_OPTS |
350 | static const char getopt_longopts[] ALIGN1 = |
351 | "viewonly\0" No_argument "v" |
352 | "createdevice\0" No_argument "c" |
353 | "session\0" No_argument "s" |
354 | "nocolors\0" No_argument "n" |
355 | "dump\0" No_argument "d" |
356 | "follow\0" No_argument "f" |
357 | ; |
358 | |
359 | applet_long_options = getopt_longopts; |
360 | #endif |
361 | INIT_G(); |
362 | strcpy(G.vcsa_name, "/dev/vcsa"); |
363 | |
364 | opt_complementary = "x+:y+"; // numeric params |
365 | opts = getopt32(argv, "vcsndfx:y:", &G.x, &G.y); |
366 | argv += optind; |
367 | ttynum = 0; |
368 | if (argv[0]) { |
369 | ttynum = xatou_range(argv[0], 0, 63); |
370 | sprintf(G.vcsa_name + sizeof("/dev/vcsa")-1, "%u", ttynum); |
371 | } |
372 | sprintf(tty_name, "%s%u", "/dev/tty", ttynum); |
373 | if (opts & FLAG(c)) { |
374 | if ((opts & (FLAG(s)|FLAG(v))) != FLAG(v)) |
375 | create_cdev_if_doesnt_exist(tty_name, makedev(4, ttynum)); |
376 | create_cdev_if_doesnt_exist(G.vcsa_name, makedev(7, 128 + ttynum)); |
377 | } |
378 | if ((opts & FLAG(s)) && ttynum) { |
379 | start_shell_in_child(tty_name); |
380 | } |
381 | |
382 | screen_read_close(); |
383 | if (opts & FLAG(d)) { |
384 | screen_dump(); |
385 | bb_putchar('\n'); |
386 | return 0; |
387 | } |
388 | |
389 | bb_signals(BB_FATAL_SIGS, cleanup); |
390 | |
391 | // All characters must be passed through to us unaltered |
392 | G.kbd_fd = xopen(CURRENT_TTY, O_RDONLY); |
393 | tcgetattr(G.kbd_fd, &G.term_orig); |
394 | termbuf = G.term_orig; |
395 | termbuf.c_iflag &= ~(BRKINT|INLCR|ICRNL|IXON|IXOFF|IUCLC|IXANY|IMAXBEL); |
396 | //termbuf.c_oflag &= ~(OPOST); - no, we still want \n -> \r\n |
397 | termbuf.c_lflag &= ~(ISIG|ICANON|ECHO); |
398 | termbuf.c_cc[VMIN] = 1; |
399 | termbuf.c_cc[VTIME] = 0; |
400 | tcsetattr(G.kbd_fd, TCSANOW, &termbuf); |
401 | |
402 | poll_timeout_ms = 250; |
403 | while (1) { |
404 | struct pollfd pfd; |
405 | int bytes_read; |
406 | int i, j; |
407 | char *data, *old; |
408 | |
409 | // in the first loop G.width = G.height = 0: refresh |
410 | i = G.width; |
411 | j = G.height; |
412 | get_terminal_width_height(G.kbd_fd, &G.width, &G.height); |
413 | if (option_mask32 & FLAG(f)) { |
414 | int nx = G.remote.cursor_x - G.width + 1; |
415 | int ny = G.remote.cursor_y - G.height + 1; |
416 | |
417 | if (G.remote.cursor_x < G.x) { |
418 | G.x = G.remote.cursor_x; |
419 | i = 0; // force refresh |
420 | } |
421 | if (nx > G.x) { |
422 | G.x = nx; |
423 | i = 0; // force refresh |
424 | } |
425 | if (G.remote.cursor_y < G.y) { |
426 | G.y = G.remote.cursor_y; |
427 | i = 0; // force refresh |
428 | } |
429 | if (ny > G.y) { |
430 | G.y = ny; |
431 | i = 0; // force refresh |
432 | } |
433 | } |
434 | |
435 | // Scan console data and redraw our tty where needed |
436 | old = G.data + G.current; |
437 | G.current = G.size - G.current; |
438 | data = G.data + G.current; |
439 | screen_read_close(); |
440 | if (i != G.width || j != G.height) { |
441 | clrscr(); |
442 | screen_dump(); |
443 | } else { |
444 | // For each remote line |
445 | old += G.first_line_offset; |
446 | data += G.first_line_offset; |
447 | for (i = G.y; i < G.remote.lines; i++) { |
448 | char *first = NULL; // first char which needs updating |
449 | char *last = last; // last char which needs updating |
450 | unsigned iy = i - G.y; |
451 | |
452 | if (iy >= G.height) |
453 | break; |
454 | for (j = 0; j < G.remote.cols; j++, NEXT(old), NEXT(data)) { |
455 | unsigned jx = j - G.x; // if will catch j >= G.x too |
456 | |
457 | if (jx < G.width && DATA(data) != DATA(old)) { |
458 | last = data; |
459 | if (!first) { |
460 | first = data; |
461 | gotoxy(jx, iy); |
462 | } |
463 | } |
464 | } |
465 | if (first) { |
466 | // Rewrite updated data on the local screen |
467 | for (; first <= last; NEXT(first)) |
468 | screen_char(first); |
469 | } |
470 | } |
471 | } |
472 | curmove(); |
473 | |
474 | // Wait for local user keypresses |
475 | fflush_all(); |
476 | pfd.fd = G.kbd_fd; |
477 | pfd.events = POLLIN; |
478 | bytes_read = 0; |
479 | switch (poll(&pfd, 1, poll_timeout_ms)) { |
480 | char *k; |
481 | case -1: |
482 | if (errno != EINTR) |
483 | cleanup(1); |
484 | break; |
485 | case 0: |
486 | if (++G.nokeys >= 4) |
487 | G.nokeys = G.escape_count = 0; |
488 | break; |
489 | default: |
490 | // Read the keys pressed |
491 | k = keybuf + G.key_count; |
492 | bytes_read = read(G.kbd_fd, k, sizeof(keybuf) - G.key_count); |
493 | if (bytes_read < 0) |
494 | cleanup(1); |
495 | |
496 | // Do exit processing |
497 | for (i = 0; i < bytes_read; i++) { |
498 | if (k[i] != '\033') |
499 | G.escape_count = 0; |
500 | else if (++G.escape_count >= 3) |
501 | cleanup(0); |
502 | } |
503 | } |
504 | poll_timeout_ms = 250; |
505 | |
506 | // Insert all keys pressed into the virtual console's input |
507 | // buffer. Don't do this if the virtual console is in scan |
508 | // code mode - giving ASCII characters to a program expecting |
509 | // scan codes will confuse it. |
510 | if (!(option_mask32 & FLAG(v)) && G.escape_count == 0) { |
511 | int handle, result; |
512 | long kbd_mode; |
513 | |
514 | G.key_count += bytes_read; |
515 | handle = xopen(tty_name, O_WRONLY); |
516 | result = ioctl(handle, KDGKBMODE, &kbd_mode); |
517 | if (result >= 0) { |
518 | char *p = keybuf; |
519 | |
520 | if (kbd_mode != K_XLATE && kbd_mode != K_UNICODE) { |
521 | G.key_count = 0; // scan code mode |
522 | } |
523 | for (; G.key_count != 0; p++, G.key_count--) { |
524 | result = ioctl(handle, TIOCSTI, p); |
525 | if (result < 0) { |
526 | memmove(keybuf, p, G.key_count); |
527 | break; |
528 | } |
529 | // If there is an application on console which reacts |
530 | // to keypresses, we need to make our first sleep |
531 | // shorter to quickly redraw whatever it printed there. |
532 | poll_timeout_ms = 20; |
533 | } |
534 | } |
535 | // Close & re-open tty in case they have |
536 | // swapped virtual consoles |
537 | close(handle); |
538 | |
539 | // We sometimes get spurious IO errors on the TTY |
540 | // as programs close and re-open it |
541 | if (result >= 0) |
542 | G.ioerror_count = 0; |
543 | else if (errno != EIO || ++G.ioerror_count > 4) |
544 | cleanup(1); |
545 | } |
546 | } /* while (1) */ |
547 | } |