src/cons.handler.c

   1 /* Client interface for General purpose Linux console save/restore server
   2    Copyright (C) 1994, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
   3    2006, 2007 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software
  17    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  18
  19 /** \file cons.handler.c
  20  *  \brief Source: client %interface for General purpose Linux console save/restore server
  21  */
  22
  23 #include <config.h>
  24
  25 #include <stdlib.h>
  26 #include <sys/wait.h>
  27 #include <signal.h>
  28 #include <stdio.h>
  29 #include <fcntl.h>
  30 #include <sys/types.h>
  31 #ifdef __FreeBSD__
  32 #include <sys/consio.h>
  33 #include <sys/ioctl.h>
  34 #endif
  35 #include <unistd.h>
  36
  37 #include "lib/global.h"
  38
  39 #include "lib/tty/tty.h"
  40 #include "lib/skin.h"           /* tty_set_normal_attrs */
  41 #include "lib/tty/win.h"
  42 #include "lib/util.h"           /* concat_dir_and_file() */
  43
  44 #include "consaver/cons.saver.h"
  45
  46 /*** global variables ****************************************************************************/
  47
  48 signed char console_flag = 0;
  49
  50 #ifdef __linux__
  51 int cons_saver_pid = 1;
  52 #endif /* __linux__ */
  53
  54 /*** file scope macro definitions ****************************************************************/
  55
  56 #if defined(__FreeBSD__)
  57 #define FD_OUT 1
  58 #define cursor_to(x, y) \
  59 do \
  60 { \
  61     printf("\x1B[%d;%df", (y) + 1, (x) + 1); \
  62     fflush(stdout); \
  63 } while (0)
  64 #endif /* __linux__ */
  65
  66 /*** file scope type declarations ****************************************************************/
  67
  68 /*** file scope variables ************************************************************************/
  69
  70 #ifdef __linux__
  71 /* The cons saver can't have a pid of 1, used to prevent bunches of
  72  * #ifdef linux */
  73 static int pipefd1[2] = { -1, -1 };
  74 static int pipefd2[2] = { -1, -1 };
  75 #elif defined(__FreeBSD__)
  76 static struct scrshot screen_shot;
  77 static struct vid_info screen_info;
  78 #endif /* __linux__ */
  79
  80 /*** file scope functions ************************************************************************/
  81 /* --------------------------------------------------------------------------------------------- */
  82
  83 #ifdef __linux__
  84 static void
  85 show_console_contents_linux (int starty, unsigned char begin_line, unsigned char end_line)
  86 {
  87     unsigned char message = 0;
  88     unsigned short bytes = 0;
  89     int i;
  90     ssize_t ret;
  91
  92     /* Is tty console? */
  93     if (!console_flag)
  94         return;
  95     /* Paranoid: Is the cons.saver still running? */
  96     if (cons_saver_pid < 1 || kill (cons_saver_pid, SIGCONT))
  97     {
  98         cons_saver_pid = 0;
  99         console_flag = 0;
 100         return;
 101     }
 102
 103     /* Send command to the console handler */
 104     message = CONSOLE_CONTENTS;
 105     ret = write (pipefd1[1], &message, 1);
 106     /* Check for outdated cons.saver */
 107     ret = read (pipefd2[0], &message, 1);
 108     if (message != CONSOLE_CONTENTS)
 109         return;
 110
 111     /* Send the range of lines that we want */
 112     ret = write (pipefd1[1], &begin_line, 1);
 113     ret = write (pipefd1[1], &end_line, 1);
 114     /* Read the corresponding number of bytes */
 115     ret = read (pipefd2[0], &bytes, 2);
 116
 117     /* Read the bytes and output them */
 118     for (i = 0; i < bytes; i++)
 119     {
 120         if ((i % COLS) == 0)
 121             tty_gotoyx (starty + (i / COLS), 0);
 122         ret = read (pipefd2[0], &message, 1);
 123         tty_print_char (message);
 124     }
 125
 126     /* Read the value of the console_flag */
 127     ret = read (pipefd2[0], &message, 1);
 128 }
 129
 130 /* --------------------------------------------------------------------------------------------- */
 131
 132 static void
 133 handle_console_linux (unsigned char action)
 134 {
 135     char *tty_name;
 136     char *mc_conssaver;
 137     int status;
 138
 139     switch (action)
 140     {
 141     case CONSOLE_INIT:
 142         /* Close old pipe ends in case it is the 2nd time we run cons.saver */
 143         status = close (pipefd1[1]);
 144         status = close (pipefd2[0]);
 145         /* Create two pipes for communication */
 146         if (!((pipe (pipefd1) == 0) && ((pipe (pipefd2)) == 0)))
 147         {
 148             console_flag = 0;
 149             break;
 150         }
 151         /* Get the console saver running */
 152         cons_saver_pid = fork ();
 153         if (cons_saver_pid < 0)
 154         {
 155             /* Cannot fork */
 156             /* Delete pipes */
 157             status = close (pipefd1[1]);
 158             status = close (pipefd1[0]);
 159             status = close (pipefd2[1]);
 160             status = close (pipefd2[0]);
 161             console_flag = 0;
 162         }
 163         else if (cons_saver_pid > 0)
 164         {
 165             /* Parent */
 166             /* Close the extra pipe ends */
 167             status = close (pipefd1[0]);
 168             status = close (pipefd2[1]);
 169             /* Was the child successful? */
 170             status = read (pipefd2[0], &console_flag, 1);
 171             if (!console_flag)
 172             {
 173                 pid_t ret;
 174                 status = close (pipefd1[1]);
 175                 status = close (pipefd2[0]);
 176                 ret = waitpid (cons_saver_pid, &status, 0);
 177             }
 178         }
 179         else
 180         {
 181             /* Child */
 182             /* Close the extra pipe ends */
 183             status = close (pipefd1[1]);
 184             status = close (pipefd2[0]);
 185             tty_name = ttyname (0);
 186             /* Bind the pipe 0 to the standard input */
 187             do
 188             {
 189                 if (dup2 (pipefd1[0], 0) == -1)
 190                     break;
 191                 status = close (pipefd1[0]);
 192                 /* Bind the pipe 1 to the standard output */
 193                 if (dup2 (pipefd2[1], 1) == -1)
 194                     break;
 195
 196                 status = close (pipefd2[1]);
 197                 /* Bind standard error to /dev/null */
 198                 status = open ("/dev/null", O_WRONLY);
 199                 if (dup2 (status, 2) == -1)
 200                     break;
 201                 status = close (status);
 202                 if (tty_name)
 203                 {
 204                     /* Exec the console save/restore handler */
 205                     mc_conssaver = concat_dir_and_file (SAVERDIR, "cons.saver");
 206                     execl (mc_conssaver, "cons.saver", tty_name, (char *) NULL);
 207                 }
 208                 /* Console is not a tty or execl() failed */
 209             }
 210             while (0);
 211             console_flag = 0;
 212             status = write (1, &console_flag, 1);
 213             _exit (3);
 214         }                       /* if (cons_saver_pid ...) */
 215         break;
 216
 217     case CONSOLE_DONE:
 218     case CONSOLE_SAVE:
 219     case CONSOLE_RESTORE:
 220         /* Is tty console? */
 221         if (!console_flag)
 222             return;
 223         /* Paranoid: Is the cons.saver still running? */
 224         if (cons_saver_pid < 1 || kill (cons_saver_pid, SIGCONT))
 225         {
 226             cons_saver_pid = 0;
 227             console_flag = 0;
 228             return;
 229         }
 230         /* Send command to the console handler */
 231         status = write (pipefd1[1], &action, 1);
 232         if (action != CONSOLE_DONE)
 233         {
 234             /* Wait the console handler to do its job */
 235             status = read (pipefd2[0], &console_flag, 1);
 236         }
 237         if (action == CONSOLE_DONE || !console_flag)
 238         {
 239             /* We are done -> Let's clean up */
 240             pid_t ret;
 241             close (pipefd1[1]);
 242             close (pipefd2[0]);
 243             ret = waitpid (cons_saver_pid, &status, 0);
 244             console_flag = 0;
 245         }
 246         break;
 247     }
 248 }
 249
 250 #elif defined(__FreeBSD__)
 251
 252 /* --------------------------------------------------------------------------------------------- */
 253 /**
 254  * FreeBSD support copyright (C) 2003 Alexander Serkov <serkov@ukrpost.net>.
 255  * Support for screenmaps by Max Khon <fjoe@FreeBSD.org>
 256  */
 257
 258 static void
 259 console_init (void)
 260 {
 261     if (console_flag)
 262         return;
 263
 264     screen_info.size = sizeof (screen_info);
 265     if (ioctl (FD_OUT, CONS_GETINFO, &screen_info) == -1)
 266         return;
 267
 268     memset (&screen_shot, 0, sizeof (screen_shot));
 269     screen_shot.xsize = screen_info.mv_csz;
 270     screen_shot.ysize = screen_info.mv_rsz;
 271     screen_shot.buf = g_try_malloc (screen_info.mv_csz * screen_info.mv_rsz * 2);
 272     if (screen_shot.buf != NULL)
 273         console_flag = 1;
 274 }
 275
 276 /* --------------------------------------------------------------------------------------------- */
 277
 278 static void
 279 set_attr (unsigned attr)
 280 {
 281     /*
 282      * Convert color indices returned by SCRSHOT (red=4, green=2, blue=1)
 283      * to indices for ANSI sequences (red=1, green=2, blue=4).
 284      */
 285     static const int color_map[8] = { 0, 4, 2, 6, 1, 5, 3, 7 };
 286     int bc, tc;
 287
 288     tc = attr & 0xF;
 289     bc = (attr >> 4) & 0xF;
 290
 291     printf ("\x1B[%d;%d;3%d;4%dm", (bc & 8) ? 5 : 25, (tc & 8) ? 1 : 22,
 292             color_map[tc & 7], color_map[bc & 7]);
 293 }
 294
 295 /* --------------------------------------------------------------------------------------------- */
 296
 297 static void
 298 console_restore (void)
 299 {
 300     int i, last;
 301
 302     if (!console_flag)
 303         return;
 304
 305     cursor_to (0, 0);
 306
 307     /* restoring all content up to cursor position */
 308     last = screen_info.mv_row * screen_info.mv_csz + screen_info.mv_col;
 309     for (i = 0; i < last; ++i)
 310     {
 311         set_attr ((screen_shot.buf[i] >> 8) & 0xFF);
 312         putc (screen_shot.buf[i] & 0xFF, stdout);
 313     }
 314
 315     /* restoring cursor color */
 316     set_attr ((screen_shot.buf[last] >> 8) & 0xFF);
 317
 318     fflush (stdout);
 319 }
 320
 321 /* --------------------------------------------------------------------------------------------- */
 322
 323 static void
 324 console_shutdown (void)
 325 {
 326     if (!console_flag)
 327         return;
 328
 329     g_free (screen_shot.buf);
 330
 331     console_flag = 0;
 332 }
 333
 334 /* --------------------------------------------------------------------------------------------- */
 335
 336 static void
 337 console_save (void)
 338 {
 339     int i;
 340     scrmap_t map;
 341     scrmap_t revmap;
 342
 343     if (!console_flag)
 344         return;
 345
 346     /* screen_info.size is already set in console_init() */
 347     if (ioctl (FD_OUT, CONS_GETINFO, &screen_info) == -1)
 348     {
 349         console_shutdown ();
 350         return;
 351     }
 352
 353     /* handle console resize */
 354     if (screen_info.mv_csz != screen_shot.xsize || screen_info.mv_rsz != screen_shot.ysize)
 355     {
 356         console_shutdown ();
 357         console_init ();
 358     }
 359
 360     if (ioctl (FD_OUT, CONS_SCRSHOT, &screen_shot) == -1)
 361     {
 362         console_shutdown ();
 363         return;
 364     }
 365
 366     if (ioctl (FD_OUT, GIO_SCRNMAP, &map) == -1)
 367     {
 368         console_shutdown ();
 369         return;
 370     }
 371
 372     for (i = 0; i < 256; i++)
 373     {
 374         char *p = memchr (map.scrmap, i, 256);
 375         revmap.scrmap[i] = p ? p - map.scrmap : i;
 376     }
 377
 378     for (i = 0; i < screen_shot.xsize * screen_shot.ysize; i++)
 379     {
 380         screen_shot.buf[i] =
 381             (screen_shot.buf[i] & 0xff00) | (unsigned char) revmap.
 382             scrmap[screen_shot.buf[i] & 0xff];
 383     }
 384 }
 385
 386 /* --------------------------------------------------------------------------------------------- */
 387
 388 static void
 389 show_console_contents_freebsd (int starty, unsigned char begin_line, unsigned char end_line)
 390 {
 391     int col, line;
 392     char c;
 393
 394     if (!console_flag)
 395         return;
 396
 397     for (line = begin_line; line <= end_line; line++)
 398     {
 399         tty_gotoyx (starty + line - begin_line, 0);
 400         for (col = 0; col < min (COLS, screen_info.mv_csz); col++)
 401         {
 402             c = screen_shot.buf[line * screen_info.mv_csz + col] & 0xFF;
 403             tty_print_char (c);
 404         }
 405     }
 406 }
 407
 408 /* --------------------------------------------------------------------------------------------- */
 409
 410 static void
 411 handle_console_freebsd (unsigned char action)
 412 {
 413     switch (action)
 414     {
 415     case CONSOLE_INIT:
 416         console_init ();
 417         break;
 418
 419     case CONSOLE_DONE:
 420         console_shutdown ();
 421         break;
 422
 423     case CONSOLE_SAVE:
 424         console_save ();
 425         break;
 426
 427     case CONSOLE_RESTORE:
 428         console_restore ();
 429         break;
 430     }
 431 }
 432 #endif /* __FreeBSD__ */
 433
 434 /* --------------------------------------------------------------------------------------------- */
 435 /*** public functions ****************************************************************************/
 436 /* --------------------------------------------------------------------------------------------- */
 437
 438 void
 439 show_console_contents (int starty, unsigned char begin_line, unsigned char end_line)
 440 {
 441     tty_set_normal_attrs ();
 442
 443     if (look_for_rxvt_extensions ())
 444     {
 445         show_rxvt_contents (starty, begin_line, end_line);
 446         return;
 447     }
 448 #ifdef __linux__
 449     show_console_contents_linux (starty, begin_line, end_line);
 450 #elif defined (__FreeBSD__)
 451     show_console_contents_freebsd (starty, begin_line, end_line);
 452 #else
 453     console_flag = 0;
 454 #endif
 455 }
 456
 457 /* --------------------------------------------------------------------------------------------- */
 458
 459 void
 460 handle_console (unsigned char action)
 461 {
 462     (void) action;
 463
 464     if (look_for_rxvt_extensions ())
 465         return;
 466
 467 #ifdef __linux__
 468     handle_console_linux (action);
 469 #elif defined (__FreeBSD__)
 470     handle_console_freebsd (action);
 471 #endif
 472 }
 473
 474 /* --------------------------------------------------------------------------------------------- */