Emeric Vigier | 2f62582 | 2012-08-06 11:09:52 -0400 | [diff] [blame] | 1 | /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ |
| 2 | /* dbus-launch.h dbus-launch utility |
| 3 | * |
| 4 | * Copyright (C) 2006 Thiago Macieira <thiago@kde.org> |
| 5 | * |
| 6 | * Licensed under the Academic Free License version 2.1 |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | * |
| 22 | */ |
| 23 | |
| 24 | #include <config.h> |
| 25 | #include "dbus-launch.h" |
| 26 | |
| 27 | #ifdef DBUS_BUILD_X11 |
| 28 | #include <stdlib.h> |
| 29 | #include <sys/types.h> |
| 30 | #include <sys/stat.h> |
| 31 | #include <unistd.h> |
| 32 | #include <fcntl.h> |
| 33 | #include <errno.h> |
| 34 | #include <stdio.h> |
| 35 | #include <string.h> |
| 36 | #include <pwd.h> |
| 37 | #include <X11/Xlib.h> |
| 38 | #include <X11/Xatom.h> |
| 39 | |
| 40 | Display *xdisplay = NULL; |
| 41 | static Atom selection_atom; |
| 42 | static Atom address_atom; |
| 43 | static Atom pid_atom; |
| 44 | |
| 45 | static int |
| 46 | x_io_error_handler (Display *xdisplay) |
| 47 | { |
| 48 | verbose ("X IO error\n"); |
| 49 | kill_bus_and_exit (0); |
| 50 | return 0; |
| 51 | } |
| 52 | |
| 53 | static void |
| 54 | remove_prefix (char *s, |
| 55 | char *prefix) |
| 56 | { |
| 57 | int plen; |
| 58 | |
| 59 | plen = strlen (prefix); |
| 60 | |
| 61 | if (strncmp (s, prefix, plen) == 0) |
| 62 | { |
| 63 | memmove (s, s + plen, strlen (s) - plen + 1); |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | static const char* |
| 68 | get_homedir (void) |
| 69 | { |
| 70 | const char *home; |
| 71 | |
| 72 | home = getenv ("HOME"); |
| 73 | if (home == NULL) |
| 74 | { |
| 75 | /* try from the user database */ |
| 76 | struct passwd *user = getpwuid (getuid()); |
| 77 | if (user != NULL) |
| 78 | home = user->pw_dir; |
| 79 | } |
| 80 | |
| 81 | if (home == NULL) |
| 82 | { |
| 83 | fprintf (stderr, "Can't get user home directory\n"); |
| 84 | exit (1); |
| 85 | } |
| 86 | |
| 87 | return home; |
| 88 | } |
| 89 | |
| 90 | #define DBUS_DIR ".dbus" |
| 91 | #define DBUS_SESSION_BUS_DIR "session-bus" |
| 92 | |
| 93 | static char * |
| 94 | get_session_file (void) |
| 95 | { |
| 96 | static const char prefix[] = "/" DBUS_DIR "/" DBUS_SESSION_BUS_DIR "/"; |
| 97 | const char *machine; |
| 98 | const char *home; |
| 99 | char *display; |
| 100 | char *result; |
| 101 | char *p; |
| 102 | |
| 103 | machine = get_machine_uuid (); |
| 104 | if (machine == NULL) |
| 105 | return NULL; |
| 106 | |
| 107 | display = xstrdup (getenv ("DISPLAY")); |
| 108 | if (display == NULL) |
| 109 | { |
| 110 | verbose ("X11 integration disabled because X11 is not running\n"); |
| 111 | return NULL; |
| 112 | } |
| 113 | |
| 114 | /* remove the screen part of the display name */ |
| 115 | p = strrchr (display, ':'); |
| 116 | if (p != NULL) |
| 117 | { |
| 118 | for ( ; *p; ++p) |
| 119 | { |
| 120 | if (*p == '.') |
| 121 | { |
| 122 | *p = '\0'; |
| 123 | break; |
| 124 | } |
| 125 | } |
| 126 | } |
| 127 | |
| 128 | /* Note that we leave the hostname in the display most of the |
| 129 | * time. The idea is that we want to be per-(machine,display,user) |
| 130 | * triplet to be extra-sure we get a bus we can connect to. Ideally |
| 131 | * we'd recognize when the hostname matches the machine we're on in |
| 132 | * all cases; we do try to drop localhost and localhost.localdomain |
| 133 | * as a special common case so that alternate spellings of DISPLAY |
| 134 | * don't result in extra bus instances. |
| 135 | * |
| 136 | * We also kill the ":" if there's nothing in front of it. This |
| 137 | * avoids an ugly double underscore in the filename. |
| 138 | */ |
| 139 | remove_prefix (display, "localhost.localdomain:"); |
| 140 | remove_prefix (display, "localhost:"); |
| 141 | remove_prefix (display, ":"); |
| 142 | |
| 143 | /* replace the : in the display with _ if the : is still there. |
| 144 | * use _ instead of - since it can't be in hostnames. |
| 145 | */ |
| 146 | for (p = display; *p; ++p) |
| 147 | { |
| 148 | if (*p == ':') |
| 149 | *p = '_'; |
| 150 | } |
| 151 | |
| 152 | home = get_homedir (); |
| 153 | |
| 154 | result = malloc (strlen (home) + strlen (prefix) + strlen (machine) + |
| 155 | strlen (display) + 2); |
| 156 | if (result == NULL) |
| 157 | { |
| 158 | /* out of memory */ |
| 159 | free (display); |
| 160 | return NULL; |
| 161 | } |
| 162 | |
| 163 | strcpy (result, home); |
| 164 | strcat (result, prefix); |
| 165 | strcat (result, machine); |
| 166 | strcat (result, "-"); |
| 167 | strcat (result, display); |
| 168 | free (display); |
| 169 | |
| 170 | verbose ("session file: %s\n", result); |
| 171 | return result; |
| 172 | } |
| 173 | |
| 174 | static void |
| 175 | ensure_session_directory (void) |
| 176 | { |
| 177 | const char *home; |
| 178 | char *dir; |
| 179 | |
| 180 | home = get_homedir (); |
| 181 | |
| 182 | /* be sure we have space for / and nul */ |
| 183 | dir = malloc (strlen (home) + strlen (DBUS_DIR) + strlen (DBUS_SESSION_BUS_DIR) + 3); |
| 184 | if (dir == NULL) |
| 185 | { |
| 186 | fprintf (stderr, "no memory\n"); |
| 187 | exit (1); |
| 188 | } |
| 189 | |
| 190 | strcpy (dir, home); |
| 191 | strcat (dir, "/"); |
| 192 | strcat (dir, DBUS_DIR); |
| 193 | |
| 194 | if (mkdir (dir, 0700) < 0) |
| 195 | { |
| 196 | /* only print a warning here, writing the session file itself will fail later */ |
| 197 | if (errno != EEXIST) |
| 198 | fprintf (stderr, "Unable to create %s\n", dir); |
| 199 | } |
| 200 | |
| 201 | strcat (dir, "/"); |
| 202 | strcat (dir, DBUS_SESSION_BUS_DIR); |
| 203 | |
| 204 | if (mkdir (dir, 0700) < 0) |
| 205 | { |
| 206 | /* only print a warning here, writing the session file itself will fail later */ |
| 207 | if (errno != EEXIST) |
| 208 | fprintf (stderr, "Unable to create %s\n", dir); |
| 209 | } |
| 210 | |
| 211 | free (dir); |
| 212 | } |
| 213 | |
| 214 | static Display * |
| 215 | open_x11 (void) |
| 216 | { |
| 217 | if (xdisplay != NULL) |
| 218 | return xdisplay; |
| 219 | |
| 220 | xdisplay = XOpenDisplay (NULL); |
| 221 | if (xdisplay != NULL) |
| 222 | { |
| 223 | verbose ("Connected to X11 display '%s'\n", DisplayString (xdisplay)); |
| 224 | XSetIOErrorHandler (x_io_error_handler); |
| 225 | } |
| 226 | return xdisplay; |
| 227 | } |
| 228 | |
| 229 | static int |
| 230 | init_x_atoms (Display *display) |
| 231 | { |
| 232 | static const char selection_prefix[] = "_DBUS_SESSION_BUS_SELECTION_"; |
| 233 | static const char address_prefix[] = "_DBUS_SESSION_BUS_ADDRESS"; |
| 234 | static const char pid_prefix[] = "_DBUS_SESSION_BUS_PID"; |
| 235 | static int init = FALSE; |
| 236 | char *atom_name; |
| 237 | const char *machine; |
| 238 | char *user_name; |
| 239 | struct passwd *user; |
| 240 | |
| 241 | if (init) |
| 242 | return TRUE; |
| 243 | |
| 244 | machine = get_machine_uuid (); |
| 245 | if (machine == NULL) |
| 246 | return FALSE; |
| 247 | |
| 248 | user = getpwuid (getuid ()); |
| 249 | if (user == NULL) |
| 250 | { |
| 251 | verbose ("Could not determine the user informations; aborting X11 integration.\n"); |
| 252 | return FALSE; |
| 253 | } |
| 254 | user_name = xstrdup(user->pw_name); |
| 255 | |
| 256 | atom_name = malloc (strlen (machine) + strlen (user_name) + 2 + |
| 257 | MAX (strlen (selection_prefix), |
| 258 | MAX (strlen (address_prefix), |
| 259 | strlen (pid_prefix)))); |
| 260 | if (atom_name == NULL) |
| 261 | { |
| 262 | verbose ("Could not create X11 atoms; aborting X11 integration.\n"); |
| 263 | free (user_name); |
| 264 | return FALSE; |
| 265 | } |
| 266 | |
| 267 | /* create the selection atom */ |
| 268 | strcpy (atom_name, selection_prefix); |
| 269 | strcat (atom_name, user_name); |
| 270 | strcat (atom_name, "_"); |
| 271 | strcat (atom_name, machine); |
| 272 | selection_atom = XInternAtom (display, atom_name, FALSE); |
| 273 | |
| 274 | /* create the address property atom */ |
| 275 | strcpy (atom_name, address_prefix); |
| 276 | address_atom = XInternAtom (display, atom_name, FALSE); |
| 277 | |
| 278 | /* create the PID property atom */ |
| 279 | strcpy (atom_name, pid_prefix); |
| 280 | pid_atom = XInternAtom (display, atom_name, FALSE); |
| 281 | |
| 282 | free (atom_name); |
| 283 | free (user_name); |
| 284 | init = TRUE; |
| 285 | return TRUE; |
| 286 | } |
| 287 | |
| 288 | /* |
| 289 | * Gets the daemon address from the X11 display. |
| 290 | * Returns FALSE if there was an error. Returning |
| 291 | * TRUE does not mean the address exists. |
| 292 | */ |
| 293 | int |
| 294 | x11_get_address (char **paddress, pid_t *pid, long *wid) |
| 295 | { |
| 296 | Atom type; |
| 297 | Window owner; |
| 298 | int format; |
| 299 | unsigned long items; |
| 300 | unsigned long after; |
| 301 | char *data; |
| 302 | |
| 303 | *paddress = NULL; |
| 304 | |
| 305 | /* locate the selection owner */ |
| 306 | owner = XGetSelectionOwner (xdisplay, selection_atom); |
| 307 | if (owner == None) |
| 308 | return TRUE; /* no owner */ |
| 309 | if (wid != NULL) |
| 310 | *wid = (long) owner; |
| 311 | |
| 312 | /* get the bus address */ |
| 313 | XGetWindowProperty (xdisplay, owner, address_atom, 0, 1024, False, |
| 314 | XA_STRING, &type, &format, &items, &after, |
| 315 | (unsigned char **) &data); |
| 316 | if (type == None || after != 0 || data == NULL || format != 8) |
| 317 | return FALSE; /* error */ |
| 318 | |
| 319 | *paddress = xstrdup (data); |
| 320 | XFree (data); |
| 321 | |
| 322 | /* get the PID */ |
| 323 | if (pid != NULL) |
| 324 | { |
| 325 | *pid = 0; |
| 326 | XGetWindowProperty (xdisplay, owner, pid_atom, 0, sizeof pid, False, |
| 327 | XA_CARDINAL, &type, &format, &items, &after, |
| 328 | (unsigned char **) &data); |
| 329 | if (type != None && after == 0 && data != NULL && format == 32) |
| 330 | *pid = (pid_t) *(long*) data; |
| 331 | XFree (data); |
| 332 | } |
| 333 | |
| 334 | return TRUE; /* success */ |
| 335 | } |
| 336 | |
| 337 | /* |
| 338 | * Saves the address in the X11 display. Returns 0 on success. |
| 339 | * If an error occurs, returns -1. If the selection already exists, |
| 340 | * returns 1. (i.e. another daemon is already running) |
| 341 | */ |
| 342 | static Window |
| 343 | set_address_in_x11(char *address, pid_t pid) |
| 344 | { |
| 345 | char *current_address; |
| 346 | Window wid = None; |
| 347 | unsigned long pid32; /* Xlib property functions want _long_ not 32-bit for format "32" */ |
| 348 | |
| 349 | /* lock the X11 display to make sure we're doing this atomically */ |
| 350 | XGrabServer (xdisplay); |
| 351 | |
| 352 | if (!x11_get_address (¤t_address, NULL, NULL)) |
| 353 | { |
| 354 | /* error! */ |
| 355 | goto out; |
| 356 | } |
| 357 | |
| 358 | if (current_address != NULL) |
| 359 | { |
| 360 | /* someone saved the address in the meantime */ |
| 361 | free (current_address); |
| 362 | goto out; |
| 363 | } |
| 364 | |
| 365 | /* Create our window */ |
| 366 | wid = XCreateWindow (xdisplay, RootWindow (xdisplay, 0), -20, -20, 10, 10, |
| 367 | 0, CopyFromParent, InputOnly, CopyFromParent, |
| 368 | 0, NULL); |
| 369 | verbose ("Created window %d\n", wid); |
| 370 | |
| 371 | /* Save the property in the window */ |
| 372 | XChangeProperty (xdisplay, wid, address_atom, XA_STRING, 8, PropModeReplace, |
| 373 | (unsigned char *)address, strlen (address)); |
| 374 | pid32 = pid; |
| 375 | XChangeProperty (xdisplay, wid, pid_atom, XA_CARDINAL, 32, PropModeReplace, |
| 376 | (unsigned char *)&pid32, 1); |
| 377 | |
| 378 | /* Now grab the selection */ |
| 379 | XSetSelectionOwner (xdisplay, selection_atom, wid, CurrentTime); |
| 380 | |
| 381 | out: |
| 382 | /* Ungrab the server to let other people use it too */ |
| 383 | XUngrabServer (xdisplay); |
| 384 | |
| 385 | /* And make sure that the ungrab gets sent to X11 */ |
| 386 | XFlush (xdisplay); |
| 387 | |
| 388 | return wid; |
| 389 | } |
| 390 | |
| 391 | /* |
| 392 | * Saves the session address in session file. Returns TRUE on |
| 393 | * success, FALSE if an error occurs. |
| 394 | */ |
| 395 | static int |
| 396 | set_address_in_file (char *address, pid_t pid, Window wid) |
| 397 | { |
| 398 | char *session_file; |
| 399 | FILE *f; |
| 400 | |
| 401 | ensure_session_directory (); |
| 402 | session_file = get_session_file(); |
| 403 | if (session_file == NULL) |
| 404 | return FALSE; |
| 405 | |
| 406 | f = fopen (session_file, "w"); |
| 407 | if (f == NULL) |
| 408 | return FALSE; /* some kind of error */ |
| 409 | fprintf (f, |
| 410 | "# This file allows processes on the machine with id %s using \n" |
| 411 | "# display %s to find the D-Bus session bus with the below address.\n" |
| 412 | "# If the DBUS_SESSION_BUS_ADDRESS environment variable is set, it will\n" |
| 413 | "# be used rather than this file.\n" |
| 414 | "# See \"man dbus-launch\" for more details.\n" |
| 415 | "DBUS_SESSION_BUS_ADDRESS=%s\n" |
| 416 | "DBUS_SESSION_BUS_PID=%ld\n" |
| 417 | "DBUS_SESSION_BUS_WINDOWID=%ld\n", |
| 418 | get_machine_uuid (), |
| 419 | getenv ("DISPLAY"), |
| 420 | address, (long)pid, (long)wid); |
| 421 | |
| 422 | fclose (f); |
| 423 | free (session_file); |
| 424 | |
| 425 | return TRUE; |
| 426 | } |
| 427 | |
| 428 | int |
| 429 | x11_save_address (char *address, pid_t pid, long *wid) |
| 430 | { |
| 431 | Window id = set_address_in_x11 (address, pid); |
| 432 | if (id != None) |
| 433 | { |
| 434 | if (!set_address_in_file (address, pid, id)) |
| 435 | return FALSE; |
| 436 | |
| 437 | if (wid != NULL) |
| 438 | *wid = (long) id; |
| 439 | return TRUE; |
| 440 | } |
| 441 | return FALSE; |
| 442 | } |
| 443 | |
| 444 | int |
| 445 | x11_init (void) |
| 446 | { |
| 447 | return open_x11 () != NULL && init_x_atoms (xdisplay); |
| 448 | } |
| 449 | |
| 450 | void |
| 451 | x11_handle_event (void) |
| 452 | { |
| 453 | if (xdisplay != NULL) |
| 454 | { |
| 455 | while (XPending (xdisplay)) |
| 456 | { |
| 457 | XEvent ignored; |
| 458 | XNextEvent (xdisplay, &ignored); |
| 459 | } |
| 460 | } |
| 461 | } |
| 462 | |
| 463 | #else |
| 464 | void dummy_dbus_launch_x11 (void); |
| 465 | |
| 466 | void dummy_dbus_launch_x11 (void) { } |
| 467 | #endif |