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
  43 #include "consaver/cons.saver.h"
  44
  45 signed char console_flag = 0;
  46
  47 #ifdef __linux__
  48
  49 /* The cons saver can't have a pid of 1, used to prevent bunches of
  50  * #ifdef linux */
  51
  52 int cons_saver_pid = 1;
  53 static int pipefd1[2] = { -1, -1 };
  54 static int pipefd2[2] = { -1, -1 };
  55
  56 static void
  57 show_console_contents_linux (int starty, unsigned char begin_line,
  58                              unsigned char end_line)
  59 {
  60     unsigned char message = 0;
  61     unsigned short bytes = 0;
  62     int i;
  63
  64     /* Is tty console? */
  65     if (!console_flag)
  66         return;
  67     /* Paranoid: Is the cons.saver still running? */
  68     if (cons_saver_pid < 1 || kill (cons_saver_pid, SIGCONT)) {
  69         cons_saver_pid = 0;
  70         console_flag = 0;
  71         return;
  72     }
  73
  74     /* Send command to the console handler */
  75     message = CONSOLE_CONTENTS;
  76     write (pipefd1[1], &message, 1);
  77     /* Check for outdated cons.saver */
  78     read (pipefd2[0], &message, 1);
  79     if (message != CONSOLE_CONTENTS)
  80         return;
  81
  82     /* Send the range of lines that we want */
  83     write (pipefd1[1], &begin_line, 1);
  84     write (pipefd1[1], &end_line, 1);
  85     /* Read the corresponding number of bytes */
  86     read (pipefd2[0], &bytes, 2);
  87
  88     /* Read the bytes and output them */
  89     for (i = 0; i < bytes; i++) {
  90         if ((i % COLS) == 0)
  91             tty_gotoyx (starty + (i / COLS), 0);
  92         read (pipefd2[0], &message, 1);
  93         tty_print_char (message);
  94     }
  95
  96     /* Read the value of the console_flag */
  97     read (pipefd2[0], &message, 1);
  98 }
  99
 100 static void
 101 handle_console_linux (unsigned char action)
 102 {
 103     char *tty_name;
 104     char *mc_conssaver;
 105     int status;
 106
 107     switch (action) {
 108     case CONSOLE_INIT:
 109         /* Close old pipe ends in case it is the 2nd time we run cons.saver */
 110         close (pipefd1[1]);
 111         close (pipefd2[0]);
 112         /* Create two pipes for communication */
 113         pipe (pipefd1);
 114         pipe (pipefd2);
 115         /* Get the console saver running */
 116         cons_saver_pid = fork ();
 117         if (cons_saver_pid < 0) {
 118             /* Cannot fork */
 119             /* Delete pipes */
 120             close (pipefd1[1]);
 121             close (pipefd1[0]);
 122             close (pipefd2[1]);
 123             close (pipefd2[0]);
 124             console_flag = 0;
 125         } else if (cons_saver_pid > 0) {
 126             /* Parent */
 127             /* Close the extra pipe ends */
 128             close (pipefd1[0]);
 129             close (pipefd2[1]);
 130             /* Was the child successful? */
 131             read (pipefd2[0], &console_flag, 1);
 132             if (!console_flag) {
 133                 close (pipefd1[1]);
 134                 close (pipefd2[0]);
 135                 waitpid (cons_saver_pid, &status, 0);
 136             }
 137         } else {
 138             /* Child */
 139             /* Close the extra pipe ends */
 140             close (pipefd1[1]);
 141             close (pipefd2[0]);
 142             tty_name = ttyname (0);
 143             /* Bind the pipe 0 to the standard input */
 144             close (0);
 145             dup (pipefd1[0]);
 146             close (pipefd1[0]);
 147             /* Bind the pipe 1 to the standard output */
 148             close (1);
 149             dup (pipefd2[1]);
 150             close (pipefd2[1]);
 151             /* Bind standard error to /dev/null */
 152             close (2);
 153             open ("/dev/null", O_WRONLY);
 154             if (tty_name) {
 155                 /* Exec the console save/restore handler */
 156                 mc_conssaver = concat_dir_and_file (SAVERDIR, "cons.saver");
 157                 execl (mc_conssaver, "cons.saver", tty_name, (char *) NULL);
 158             }
 159             /* Console is not a tty or execl() failed */
 160             console_flag = 0;
 161             write (1, &console_flag, 1);
 162             _exit (3);
 163         }                       /* if (cons_saver_pid ...) */
 164         break;
 165
 166     case CONSOLE_DONE:
 167     case CONSOLE_SAVE:
 168     case CONSOLE_RESTORE:
 169         /* Is tty console? */
 170         if (!console_flag)
 171             return;
 172         /* Paranoid: Is the cons.saver still running? */
 173         if (cons_saver_pid < 1 || kill (cons_saver_pid, SIGCONT)) {
 174             cons_saver_pid = 0;
 175             console_flag = 0;
 176             return;
 177         }
 178         /* Send command to the console handler */
 179         write (pipefd1[1], &action, 1);
 180         if (action != CONSOLE_DONE) {
 181             /* Wait the console handler to do its job */
 182             read (pipefd2[0], &console_flag, 1);
 183         }
 184         if (action == CONSOLE_DONE || !console_flag) {
 185             /* We are done -> Let's clean up */
 186             close (pipefd1[1]);
 187             close (pipefd2[0]);
 188             waitpid (cons_saver_pid, &status, 0);
 189             console_flag = 0;
 190         }
 191         break;
 192     }
 193 }
 194
 195 #elif defined(__FreeBSD__)
 196
 197 /*
 198  * FreeBSD support copyright (C) 2003 Alexander Serkov <serkov@ukrpost.net>.
 199  * Support for screenmaps by Max Khon <fjoe@FreeBSD.org>
 200  */
 201
 202 #define FD_OUT 1
 203
 204 static struct scrshot screen_shot;
 205 static struct vid_info screen_info;
 206
 207 static void
 208 console_init (void)
 209 {
 210     if (console_flag)
 211         return;
 212
 213     screen_info.size = sizeof (screen_info);
 214     if (ioctl (FD_OUT, CONS_GETINFO, &screen_info) == -1)
 215         return;
 216
 217     memset (&screen_shot, 0, sizeof (screen_shot));
 218     screen_shot.xsize = screen_info.mv_csz;
 219     screen_shot.ysize = screen_info.mv_rsz;
 220     screen_shot.buf = g_try_malloc (screen_info.mv_csz * screen_info.mv_rsz * 2);
 221     if (screen_shot.buf != NULL)
 222         console_flag = 1;
 223 }
 224
 225 static void
 226 set_attr (unsigned attr)
 227 {
 228     /*
 229      * Convert color indices returned by SCRSHOT (red=4, green=2, blue=1)
 230      * to indices for ANSI sequences (red=1, green=2, blue=4).
 231      */
 232     static const int color_map[8] = { 0, 4, 2, 6, 1, 5, 3, 7 };
 233     int bc, tc;
 234
 235     tc = attr & 0xF;
 236     bc = (attr >> 4) & 0xF;
 237
 238     printf ("\x1B[%d;%d;3%d;4%dm", (bc & 8) ? 5 : 25, (tc & 8) ? 1 : 22,
 239             color_map[tc & 7], color_map[bc & 7]);
 240 }
 241
 242 #define cursor_to(x, y) do {                            \
 243         printf("\x1B[%d;%df", (y) + 1, (x) + 1);        \
 244         fflush(stdout);                                 \
 245 } while (0)
 246
 247 static void
 248 console_restore (void)
 249 {
 250     int i, last;
 251
 252     if (!console_flag)
 253         return;
 254
 255     cursor_to (0, 0);
 256
 257     /* restoring all content up to cursor position */
 258     last = screen_info.mv_row * screen_info.mv_csz + screen_info.mv_col;
 259     for (i = 0; i < last; ++i) {
 260         set_attr ((screen_shot.buf[i] >> 8) & 0xFF);
 261         putc (screen_shot.buf[i] & 0xFF, stdout);
 262     }
 263
 264     /* restoring cursor color */
 265     set_attr ((screen_shot.buf[last] >> 8) & 0xFF);
 266
 267     fflush (stdout);
 268 }
 269
 270 static void
 271 console_shutdown (void)
 272 {
 273     if (!console_flag)
 274         return;
 275
 276     g_free (screen_shot.buf);
 277
 278     console_flag = 0;
 279 }
 280
 281 static void
 282 console_save (void)
 283 {
 284     int i;
 285     scrmap_t map;
 286     scrmap_t revmap;
 287
 288     if (!console_flag)
 289         return;
 290
 291     /* screen_info.size is already set in console_init() */
 292     if (ioctl (FD_OUT, CONS_GETINFO, &screen_info) == -1) {
 293         console_shutdown ();
 294         return;
 295     }
 296
 297     /* handle console resize */
 298     if (screen_info.mv_csz != screen_shot.xsize
 299         || screen_info.mv_rsz != screen_shot.ysize) {
 300         console_shutdown ();
 301         console_init ();
 302     }
 303
 304     if (ioctl (FD_OUT, CONS_SCRSHOT, &screen_shot) == -1) {
 305         console_shutdown ();
 306         return;
 307     }
 308
 309     if (ioctl (FD_OUT, GIO_SCRNMAP, &map) == -1) {
 310         console_shutdown ();
 311         return;
 312     }
 313
 314     for (i = 0; i < 256; i++) {
 315         char *p = memchr (map.scrmap, i, 256);
 316         revmap.scrmap[i] = p ? p - map.scrmap : i;
 317     }
 318
 319     for (i = 0; i < screen_shot.xsize * screen_shot.ysize; i++) {
 320         screen_shot.buf[i] =
 321             (screen_shot.buf[i] & 0xff00) | (unsigned char) revmap.
 322             scrmap[screen_shot.buf[i] & 0xff];
 323     }
 324 }
 325
 326 static void
 327 show_console_contents_freebsd (int starty, unsigned char begin_line,
 328                                unsigned char end_line)
 329 {
 330     int col, line;
 331     char c;
 332
 333     if (!console_flag)
 334         return;
 335
 336     for (line = begin_line; line <= end_line; line++) {
 337         tty_gotoyx (starty + line - begin_line, 0);
 338         for (col = 0; col < min (COLS, screen_info.mv_csz); col++) {
 339             c = screen_shot.buf[line * screen_info.mv_csz + col] & 0xFF;
 340             tty_print_char (c);
 341         }
 342     }
 343 }
 344
 345 static void
 346 handle_console_freebsd (unsigned char action)
 347 {
 348     switch (action) {
 349     case CONSOLE_INIT:
 350         console_init ();
 351         break;
 352
 353     case CONSOLE_DONE:
 354         console_shutdown ();
 355         break;
 356
 357     case CONSOLE_SAVE:
 358         console_save ();
 359         break;
 360
 361     case CONSOLE_RESTORE:
 362         console_restore ();
 363         break;
 364     }
 365 }
 366 #endif                          /* __FreeBSD__ */
 367
 368 void
 369 show_console_contents (int starty, unsigned char begin_line,
 370                        unsigned char end_line)
 371 {
 372     tty_set_normal_attrs ();
 373
 374     if (look_for_rxvt_extensions ()) {
 375         show_rxvt_contents (starty, begin_line, end_line);
 376         return;
 377     }
 378 #ifdef __linux__
 379     show_console_contents_linux (starty, begin_line, end_line);
 380 #elif defined (__FreeBSD__)
 381     show_console_contents_freebsd (starty, begin_line, end_line);
 382 #else
 383     console_flag = 0;
 384 #endif
 385 }
 386
 387 void
 388 handle_console (unsigned char action)
 389 {
 390     (void) action;
 391
 392     if (look_for_rxvt_extensions ())
 393         return;
 394
 395 #ifdef __linux__
 396     handle_console_linux (action);
 397 #elif defined (__FreeBSD__)
 398     handle_console_freebsd (action);
 399 #endif
 400 }