i3
ipc.c
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1 #undef I3__FILE__
2 #define I3__FILE__ "ipc.c"
3 /*
4  * vim:ts=4:sw=4:expandtab
5  *
6  * i3 - an improved dynamic tiling window manager
7  * © 2009-2012 Michael Stapelberg and contributors (see also: LICENSE)
8  *
9  * ipc.c: UNIX domain socket IPC (initialization, client handling, protocol).
10  *
11  */
12 #include "all.h"
13 #include "yajl_utils.h"
14 
15 #include <sys/socket.h>
16 #include <sys/un.h>
17 #include <fcntl.h>
18 #include <libgen.h>
19 #include <ev.h>
20 #include <yajl/yajl_gen.h>
21 #include <yajl/yajl_parse.h>
22 
23 char *current_socketpath = NULL;
24 
25 TAILQ_HEAD(ipc_client_head, ipc_client) all_clients = TAILQ_HEAD_INITIALIZER(all_clients);
26 
27 /*
28  * Puts the given socket file descriptor into non-blocking mode or dies if
29  * setting O_NONBLOCK failed. Non-blocking sockets are a good idea for our
30  * IPC model because we should by no means block the window manager.
31  *
32  */
33 static void set_nonblock(int sockfd) {
34  int flags = fcntl(sockfd, F_GETFL, 0);
35  flags |= O_NONBLOCK;
36  if (fcntl(sockfd, F_SETFL, flags) < 0)
37  err(-1, "Could not set O_NONBLOCK");
38 }
39 
40 /*
41  * Emulates mkdir -p (creates any missing folders)
42  *
43  */
44 static bool mkdirp(const char *path) {
45  if (mkdir(path, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) == 0)
46  return true;
47  if (errno != ENOENT) {
48  ELOG("mkdir(%s) failed: %s\n", path, strerror(errno));
49  return false;
50  }
51  char *copy = sstrdup(path);
52  /* strip trailing slashes, if any */
53  while (copy[strlen(copy)-1] == '/')
54  copy[strlen(copy)-1] = '\0';
55 
56  char *sep = strrchr(copy, '/');
57  if (sep == NULL) {
58  FREE(copy);
59  return false;
60  }
61  *sep = '\0';
62  bool result = false;
63  if (mkdirp(copy))
64  result = mkdirp(path);
65  free(copy);
66 
67  return result;
68 }
69 
70 /*
71  * Sends the specified event to all IPC clients which are currently connected
72  * and subscribed to this kind of event.
73  *
74  */
75 void ipc_send_event(const char *event, uint32_t message_type, const char *payload) {
76  ipc_client *current;
77  TAILQ_FOREACH(current, &all_clients, clients) {
78  /* see if this client is interested in this event */
79  bool interested = false;
80  for (int i = 0; i < current->num_events; i++) {
81  if (strcasecmp(current->events[i], event) != 0)
82  continue;
83  interested = true;
84  break;
85  }
86  if (!interested)
87  continue;
88 
89  ipc_send_message(current->fd, strlen(payload), message_type, (const uint8_t*)payload);
90  }
91 }
92 
93 /*
94  * Calls shutdown() on each socket and closes it. This function to be called
95  * when exiting or restarting only!
96  *
97  */
98 void ipc_shutdown(void) {
99  ipc_client *current;
100  while (!TAILQ_EMPTY(&all_clients)) {
101  current = TAILQ_FIRST(&all_clients);
102  shutdown(current->fd, SHUT_RDWR);
103  close(current->fd);
104  TAILQ_REMOVE(&all_clients, current, clients);
105  free(current);
106  }
107 }
108 
109 /*
110  * Executes the command and returns whether it could be successfully parsed
111  * or not (at the moment, always returns true).
112  *
113  */
114 IPC_HANDLER(command) {
115  /* To get a properly terminated buffer, we copy
116  * message_size bytes out of the buffer */
117  char *command = scalloc(message_size + 1);
118  strncpy(command, (const char*)message, message_size);
119  LOG("IPC: received: *%s*\n", command);
120  struct CommandResult *command_output = parse_command((const char*)command);
121  free(command);
122 
123  if (command_output->needs_tree_render)
124  tree_render();
125 
126  const unsigned char *reply;
127  ylength length;
128  yajl_gen_get_buf(command_output->json_gen, &reply, &length);
129 
130  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_COMMAND,
131  (const uint8_t*)reply);
132 
133  yajl_gen_free(command_output->json_gen);
134 }
135 
136 static void dump_rect(yajl_gen gen, const char *name, Rect r) {
137  ystr(name);
138  y(map_open);
139  ystr("x");
140  y(integer, r.x);
141  ystr("y");
142  y(integer, r.y);
143  ystr("width");
144  y(integer, r.width);
145  ystr("height");
146  y(integer, r.height);
147  y(map_close);
148 }
149 
150 void dump_node(yajl_gen gen, struct Con *con, bool inplace_restart) {
151  y(map_open);
152  ystr("id");
153  y(integer, (long int)con);
154 
155  ystr("type");
156  y(integer, con->type);
157 
158  /* provided for backwards compatibility only. */
159  ystr("orientation");
160  if (!con_is_split(con))
161  ystr("none");
162  else {
163  if (con_orientation(con) == HORIZ)
164  ystr("horizontal");
165  else ystr("vertical");
166  }
167 
168  ystr("scratchpad_state");
169  switch (con->scratchpad_state) {
170  case SCRATCHPAD_NONE:
171  ystr("none");
172  break;
173  case SCRATCHPAD_FRESH:
174  ystr("fresh");
175  break;
176  case SCRATCHPAD_CHANGED:
177  ystr("changed");
178  break;
179  }
180 
181  ystr("percent");
182  if (con->percent == 0.0)
183  y(null);
184  else y(double, con->percent);
185 
186  ystr("urgent");
187  y(bool, con->urgent);
188 
189  if (con->mark != NULL) {
190  ystr("mark");
191  ystr(con->mark);
192  }
193 
194  ystr("focused");
195  y(bool, (con == focused));
196 
197  ystr("layout");
198  switch (con->layout) {
199  case L_DEFAULT:
200  DLOG("About to dump layout=default, this is a bug in the code.\n");
201  assert(false);
202  break;
203  case L_SPLITV:
204  ystr("splitv");
205  break;
206  case L_SPLITH:
207  ystr("splith");
208  break;
209  case L_STACKED:
210  ystr("stacked");
211  break;
212  case L_TABBED:
213  ystr("tabbed");
214  break;
215  case L_DOCKAREA:
216  ystr("dockarea");
217  break;
218  case L_OUTPUT:
219  ystr("output");
220  break;
221  }
222 
223  ystr("workspace_layout");
224  switch (con->workspace_layout) {
225  case L_DEFAULT:
226  ystr("default");
227  break;
228  case L_STACKED:
229  ystr("stacked");
230  break;
231  case L_TABBED:
232  ystr("tabbed");
233  break;
234  default:
235  DLOG("About to dump workspace_layout=%d (none of default/stacked/tabbed), this is a bug.\n", con->workspace_layout);
236  assert(false);
237  break;
238  }
239 
240  ystr("last_split_layout");
241  switch (con->layout) {
242  case L_SPLITV:
243  ystr("splitv");
244  break;
245  default:
246  ystr("splith");
247  break;
248  }
249 
250  ystr("border");
251  switch (con->border_style) {
252  case BS_NORMAL:
253  ystr("normal");
254  break;
255  case BS_NONE:
256  ystr("none");
257  break;
258  case BS_PIXEL:
259  ystr("pixel");
260  break;
261  }
262 
263  ystr("current_border_width");
264  y(integer, con->current_border_width);
265 
266  dump_rect(gen, "rect", con->rect);
267  dump_rect(gen, "window_rect", con->window_rect);
268  dump_rect(gen, "geometry", con->geometry);
269 
270  ystr("name");
271  if (con->window && con->window->name)
272  ystr(i3string_as_utf8(con->window->name));
273  else
274  ystr(con->name);
275 
276  if (con->type == CT_WORKSPACE) {
277  ystr("num");
278  y(integer, con->num);
279  }
280 
281  ystr("window");
282  if (con->window)
283  y(integer, con->window->id);
284  else y(null);
285 
286  ystr("nodes");
287  y(array_open);
288  Con *node;
289  if (con->type != CT_DOCKAREA || !inplace_restart) {
290  TAILQ_FOREACH(node, &(con->nodes_head), nodes) {
291  dump_node(gen, node, inplace_restart);
292  }
293  }
294  y(array_close);
295 
296  ystr("floating_nodes");
297  y(array_open);
298  TAILQ_FOREACH(node, &(con->floating_head), floating_windows) {
299  dump_node(gen, node, inplace_restart);
300  }
301  y(array_close);
302 
303  ystr("focus");
304  y(array_open);
305  TAILQ_FOREACH(node, &(con->focus_head), focused) {
306  y(integer, (long int)node);
307  }
308  y(array_close);
309 
310  ystr("fullscreen_mode");
311  y(integer, con->fullscreen_mode);
312 
313  ystr("floating");
314  switch (con->floating) {
315  case FLOATING_AUTO_OFF:
316  ystr("auto_off");
317  break;
318  case FLOATING_AUTO_ON:
319  ystr("auto_on");
320  break;
321  case FLOATING_USER_OFF:
322  ystr("user_off");
323  break;
324  case FLOATING_USER_ON:
325  ystr("user_on");
326  break;
327  }
328 
329  ystr("swallows");
330  y(array_open);
331  Match *match;
332  TAILQ_FOREACH(match, &(con->swallow_head), matches) {
333  if (match->dock != -1) {
334  y(map_open);
335  ystr("dock");
336  y(integer, match->dock);
337  ystr("insert_where");
338  y(integer, match->insert_where);
339  y(map_close);
340  }
341 
342  /* TODO: the other swallow keys */
343  }
344 
345  if (inplace_restart) {
346  if (con->window != NULL) {
347  y(map_open);
348  ystr("id");
349  y(integer, con->window->id);
350  ystr("restart_mode");
351  y(bool, true);
352  y(map_close);
353  }
354  }
355  y(array_close);
356 
357  y(map_close);
358 }
359 
360 IPC_HANDLER(tree) {
361  setlocale(LC_NUMERIC, "C");
362  yajl_gen gen = ygenalloc();
363  dump_node(gen, croot, false);
364  setlocale(LC_NUMERIC, "");
365 
366  const unsigned char *payload;
367  ylength length;
368  y(get_buf, &payload, &length);
369 
370  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_TREE, payload);
371  y(free);
372 }
373 
374 
375 /*
376  * Formats the reply message for a GET_WORKSPACES request and sends it to the
377  * client
378  *
379  */
380 IPC_HANDLER(get_workspaces) {
381  yajl_gen gen = ygenalloc();
382  y(array_open);
383 
384  Con *focused_ws = con_get_workspace(focused);
385 
386  Con *output;
387  TAILQ_FOREACH(output, &(croot->nodes_head), nodes) {
388  if (con_is_internal(output))
389  continue;
390  Con *ws;
391  TAILQ_FOREACH(ws, &(output_get_content(output)->nodes_head), nodes) {
392  assert(ws->type == CT_WORKSPACE);
393  y(map_open);
394 
395  ystr("num");
396  if (ws->num == -1)
397  y(null);
398  else y(integer, ws->num);
399 
400  ystr("name");
401  ystr(ws->name);
402 
403  ystr("visible");
404  y(bool, workspace_is_visible(ws));
405 
406  ystr("focused");
407  y(bool, ws == focused_ws);
408 
409  ystr("rect");
410  y(map_open);
411  ystr("x");
412  y(integer, ws->rect.x);
413  ystr("y");
414  y(integer, ws->rect.y);
415  ystr("width");
416  y(integer, ws->rect.width);
417  ystr("height");
418  y(integer, ws->rect.height);
419  y(map_close);
420 
421  ystr("output");
422  ystr(output->name);
423 
424  ystr("urgent");
425  y(bool, ws->urgent);
426 
427  y(map_close);
428  }
429  }
430 
431  y(array_close);
432 
433  const unsigned char *payload;
434  ylength length;
435  y(get_buf, &payload, &length);
436 
437  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_WORKSPACES, payload);
438  y(free);
439 }
440 
441 /*
442  * Formats the reply message for a GET_OUTPUTS request and sends it to the
443  * client
444  *
445  */
446 IPC_HANDLER(get_outputs) {
447  yajl_gen gen = ygenalloc();
448  y(array_open);
449 
450  Output *output;
451  TAILQ_FOREACH(output, &outputs, outputs) {
452  y(map_open);
453 
454  ystr("name");
455  ystr(output->name);
456 
457  ystr("active");
458  y(bool, output->active);
459 
460  ystr("primary");
461  y(bool, output->primary);
462 
463  ystr("rect");
464  y(map_open);
465  ystr("x");
466  y(integer, output->rect.x);
467  ystr("y");
468  y(integer, output->rect.y);
469  ystr("width");
470  y(integer, output->rect.width);
471  ystr("height");
472  y(integer, output->rect.height);
473  y(map_close);
474 
475  ystr("current_workspace");
476  Con *ws = NULL;
477  if (output->con && (ws = con_get_fullscreen_con(output->con, CF_OUTPUT)))
478  ystr(ws->name);
479  else y(null);
480 
481  y(map_close);
482  }
483 
484  y(array_close);
485 
486  const unsigned char *payload;
487  ylength length;
488  y(get_buf, &payload, &length);
489 
490  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_OUTPUTS, payload);
491  y(free);
492 }
493 
494 /*
495  * Formats the reply message for a GET_MARKS request and sends it to the
496  * client
497  *
498  */
499 IPC_HANDLER(get_marks) {
500  yajl_gen gen = ygenalloc();
501  y(array_open);
502 
503  Con *con;
505  if (con->mark != NULL)
506  ystr(con->mark);
507 
508  y(array_close);
509 
510  const unsigned char *payload;
511  ylength length;
512  y(get_buf, &payload, &length);
513 
514  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_MARKS, payload);
515  y(free);
516 }
517 
518 /*
519  * Returns the version of i3
520  *
521  */
522 IPC_HANDLER(get_version) {
523  yajl_gen gen = ygenalloc();
524  y(map_open);
525 
526  ystr("major");
527  y(integer, MAJOR_VERSION);
528 
529  ystr("minor");
530  y(integer, MINOR_VERSION);
531 
532  ystr("patch");
533  y(integer, PATCH_VERSION);
534 
535  ystr("human_readable");
536  ystr(I3_VERSION);
537 
538  y(map_close);
539 
540  const unsigned char *payload;
541  ylength length;
542  y(get_buf, &payload, &length);
543 
544  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_VERSION, payload);
545  y(free);
546 }
547 
548 /*
549  * Formats the reply message for a GET_BAR_CONFIG request and sends it to the
550  * client.
551  *
552  */
553 IPC_HANDLER(get_bar_config) {
554  yajl_gen gen = ygenalloc();
555 
556  /* If no ID was passed, we return a JSON array with all IDs */
557  if (message_size == 0) {
558  y(array_open);
559  Barconfig *current;
560  TAILQ_FOREACH(current, &barconfigs, configs) {
561  ystr(current->id);
562  }
563  y(array_close);
564 
565  const unsigned char *payload;
566  ylength length;
567  y(get_buf, &payload, &length);
568 
569  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_BAR_CONFIG, payload);
570  y(free);
571  return;
572  }
573 
574  /* To get a properly terminated buffer, we copy
575  * message_size bytes out of the buffer */
576  char *bar_id = scalloc(message_size + 1);
577  strncpy(bar_id, (const char*)message, message_size);
578  LOG("IPC: looking for config for bar ID \"%s\"\n", bar_id);
579  Barconfig *current, *config = NULL;
580  TAILQ_FOREACH(current, &barconfigs, configs) {
581  if (strcmp(current->id, bar_id) != 0)
582  continue;
583 
584  config = current;
585  break;
586  }
587 
588  y(map_open);
589 
590  if (!config) {
591  /* If we did not find a config for the given ID, the reply will contain
592  * a null 'id' field. */
593  ystr("id");
594  y(null);
595  } else {
596  ystr("id");
597  ystr(config->id);
598 
599  if (config->num_outputs > 0) {
600  ystr("outputs");
601  y(array_open);
602  for (int c = 0; c < config->num_outputs; c++)
603  ystr(config->outputs[c]);
604  y(array_close);
605  }
606 
607 #define YSTR_IF_SET(name) \
608  do { \
609  if (config->name) { \
610  ystr( # name); \
611  ystr(config->name); \
612  } \
613  } while (0)
614 
615  YSTR_IF_SET(tray_output);
616  YSTR_IF_SET(socket_path);
617 
618  ystr("mode");
619  if (config->mode == M_HIDE)
620  ystr("hide");
621  else ystr("dock");
622 
623  ystr("modifier");
624  switch (config->modifier) {
625  case M_CONTROL:
626  ystr("ctrl");
627  break;
628  case M_SHIFT:
629  ystr("shift");
630  break;
631  case M_MOD1:
632  ystr("Mod1");
633  break;
634  case M_MOD2:
635  ystr("Mod2");
636  break;
637  case M_MOD3:
638  ystr("Mod3");
639  break;
640  /*
641  case M_MOD4:
642  ystr("Mod4");
643  break;
644  */
645  case M_MOD5:
646  ystr("Mod5");
647  break;
648  default:
649  ystr("Mod4");
650  break;
651  }
652 
653  ystr("position");
654  if (config->position == P_BOTTOM)
655  ystr("bottom");
656  else ystr("top");
657 
658  YSTR_IF_SET(status_command);
659  YSTR_IF_SET(font);
660 
661  ystr("workspace_buttons");
662  y(bool, !config->hide_workspace_buttons);
663 
664  ystr("verbose");
665  y(bool, config->verbose);
666 
667 #undef YSTR_IF_SET
668 #define YSTR_IF_SET(name) \
669  do { \
670  if (config->colors.name) { \
671  ystr( # name); \
672  ystr(config->colors.name); \
673  } \
674  } while (0)
675 
676  ystr("colors");
677  y(map_open);
678  YSTR_IF_SET(background);
679  YSTR_IF_SET(statusline);
680  YSTR_IF_SET(focused_workspace_border);
681  YSTR_IF_SET(focused_workspace_bg);
682  YSTR_IF_SET(focused_workspace_text);
683  YSTR_IF_SET(active_workspace_border);
684  YSTR_IF_SET(active_workspace_bg);
685  YSTR_IF_SET(active_workspace_text);
686  YSTR_IF_SET(inactive_workspace_border);
687  YSTR_IF_SET(inactive_workspace_bg);
688  YSTR_IF_SET(inactive_workspace_text);
689  YSTR_IF_SET(urgent_workspace_border);
690  YSTR_IF_SET(urgent_workspace_bg);
691  YSTR_IF_SET(urgent_workspace_text);
692  y(map_close);
693 
694 #undef YSTR_IF_SET
695  }
696 
697  y(map_close);
698 
699  const unsigned char *payload;
700  ylength length;
701  y(get_buf, &payload, &length);
702 
703  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_BAR_CONFIG, payload);
704  y(free);
705 }
706 
707 /*
708  * Callback for the YAJL parser (will be called when a string is parsed).
709  *
710  */
711 static int add_subscription(void *extra, const unsigned char *s,
712  ylength len) {
713  ipc_client *client = extra;
714 
715  DLOG("should add subscription to extra %p, sub %.*s\n", client, (int)len, s);
716  int event = client->num_events;
717 
718  client->num_events++;
719  client->events = realloc(client->events, client->num_events * sizeof(char*));
720  /* We copy the string because it is not null-terminated and strndup()
721  * is missing on some BSD systems */
722  client->events[event] = scalloc(len+1);
723  memcpy(client->events[event], s, len);
724 
725  DLOG("client is now subscribed to:\n");
726  for (int i = 0; i < client->num_events; i++)
727  DLOG("event %s\n", client->events[i]);
728  DLOG("(done)\n");
729 
730  return 1;
731 }
732 
733 /*
734  * Subscribes this connection to the event types which were given as a JSON
735  * serialized array in the payload field of the message.
736  *
737  */
738 IPC_HANDLER(subscribe) {
739  yajl_handle p;
740  yajl_callbacks callbacks;
741  yajl_status stat;
742  ipc_client *current, *client = NULL;
743 
744  /* Search the ipc_client structure for this connection */
745  TAILQ_FOREACH(current, &all_clients, clients) {
746  if (current->fd != fd)
747  continue;
748 
749  client = current;
750  break;
751  }
752 
753  if (client == NULL) {
754  ELOG("Could not find ipc_client data structure for fd %d\n", fd);
755  return;
756  }
757 
758  /* Setup the JSON parser */
759  memset(&callbacks, 0, sizeof(yajl_callbacks));
760  callbacks.yajl_string = add_subscription;
761 
762  p = yalloc(&callbacks, (void*)client);
763  stat = yajl_parse(p, (const unsigned char*)message, message_size);
764  if (stat != yajl_status_ok) {
765  unsigned char *err;
766  err = yajl_get_error(p, true, (const unsigned char*)message,
767  message_size);
768  ELOG("YAJL parse error: %s\n", err);
769  yajl_free_error(p, err);
770 
771  const char *reply = "{\"success\":false}";
772  ipc_send_message(fd, strlen(reply), I3_IPC_REPLY_TYPE_SUBSCRIBE, (const uint8_t*)reply);
773  yajl_free(p);
774  return;
775  }
776  yajl_free(p);
777  const char *reply = "{\"success\":true}";
778  ipc_send_message(fd, strlen(reply), I3_IPC_REPLY_TYPE_SUBSCRIBE, (const uint8_t*)reply);
779 }
780 
781 /* The index of each callback function corresponds to the numeric
782  * value of the message type (see include/i3/ipc.h) */
784  handle_command,
785  handle_get_workspaces,
786  handle_subscribe,
787  handle_get_outputs,
788  handle_tree,
789  handle_get_marks,
790  handle_get_bar_config,
791  handle_get_version,
792 };
793 
794 /*
795  * Handler for activity on a client connection, receives a message from a
796  * client.
797  *
798  * For now, the maximum message size is 2048. I’m not sure for what the
799  * IPC interface will be used in the future, thus I’m not implementing a
800  * mechanism for arbitrarily long messages, as it seems like overkill
801  * at the moment.
802  *
803  */
804 static void ipc_receive_message(EV_P_ struct ev_io *w, int revents) {
805  char buf[2048];
806  int n = read(w->fd, buf, sizeof(buf));
807 
808  /* On error or an empty message, we close the connection */
809  if (n <= 0) {
810 #if 0
811  /* FIXME: I get these when closing a client socket,
812  * therefore we just treat them as an error. Is this
813  * correct? */
814  if (errno == EAGAIN || errno == EWOULDBLOCK)
815  return;
816 #endif
817 
818  /* If not, there was some kind of error. We don’t bother
819  * and close the connection */
820  close(w->fd);
821 
822  /* Delete the client from the list of clients */
823  ipc_client *current;
824  TAILQ_FOREACH(current, &all_clients, clients) {
825  if (current->fd != w->fd)
826  continue;
827 
828  for (int i = 0; i < current->num_events; i++)
829  free(current->events[i]);
830  /* We can call TAILQ_REMOVE because we break out of the
831  * TAILQ_FOREACH afterwards */
832  TAILQ_REMOVE(&all_clients, current, clients);
833  free(current);
834  break;
835  }
836 
837  ev_io_stop(EV_A_ w);
838  free(w);
839 
840  DLOG("IPC: client disconnected\n");
841  return;
842  }
843 
844  /* Terminate the message correctly */
845  buf[n] = '\0';
846 
847  /* Check if the message starts with the i3 IPC magic code */
848  if (n < strlen(I3_IPC_MAGIC)) {
849  DLOG("IPC: message too short, ignoring\n");
850  return;
851  }
852 
853  if (strncmp(buf, I3_IPC_MAGIC, strlen(I3_IPC_MAGIC)) != 0) {
854  DLOG("IPC: message does not start with the IPC magic\n");
855  return;
856  }
857 
858  uint8_t *message = (uint8_t*)buf;
859  while (n > 0) {
860  DLOG("IPC: n = %d\n", n);
861  message += strlen(I3_IPC_MAGIC);
862  n -= strlen(I3_IPC_MAGIC);
863 
864  /* The next 32 bit after the magic are the message size */
865  uint32_t message_size;
866  memcpy(&message_size, (uint32_t*)message, sizeof(uint32_t));
867  message += sizeof(uint32_t);
868  n -= sizeof(uint32_t);
869 
870  if (message_size > n) {
871  DLOG("IPC: Either the message size was wrong or the message was not read completely, dropping\n");
872  return;
873  }
874 
875  /* The last 32 bits of the header are the message type */
876  uint32_t message_type;
877  memcpy(&message_type, (uint32_t*)message, sizeof(uint32_t));
878  message += sizeof(uint32_t);
879  n -= sizeof(uint32_t);
880 
881  if (message_type >= (sizeof(handlers) / sizeof(handler_t)))
882  DLOG("Unhandled message type: %d\n", message_type);
883  else {
884  handler_t h = handlers[message_type];
885  h(w->fd, message, n, message_size, message_type);
886  }
887  n -= message_size;
888  message += message_size;
889  }
890 }
891 
892 /*
893  * Handler for activity on the listening socket, meaning that a new client
894  * has just connected and we should accept() him. Sets up the event handler
895  * for activity on the new connection and inserts the file descriptor into
896  * the list of clients.
897  *
898  */
899 void ipc_new_client(EV_P_ struct ev_io *w, int revents) {
900  struct sockaddr_un peer;
901  socklen_t len = sizeof(struct sockaddr_un);
902  int client;
903  if ((client = accept(w->fd, (struct sockaddr*)&peer, &len)) < 0) {
904  if (errno == EINTR)
905  return;
906  else perror("accept()");
907  return;
908  }
909 
910  /* Close this file descriptor on exec() */
911  (void)fcntl(client, F_SETFD, FD_CLOEXEC);
912 
913  set_nonblock(client);
914 
915  struct ev_io *package = scalloc(sizeof(struct ev_io));
916  ev_io_init(package, ipc_receive_message, client, EV_READ);
917  ev_io_start(EV_A_ package);
918 
919  DLOG("IPC: new client connected on fd %d\n", w->fd);
920 
921  ipc_client *new = scalloc(sizeof(ipc_client));
922  new->fd = client;
923 
924  TAILQ_INSERT_TAIL(&all_clients, new, clients);
925 }
926 
927 /*
928  * Creates the UNIX domain socket at the given path, sets it to non-blocking
929  * mode, bind()s and listen()s on it.
930  *
931  */
932 int ipc_create_socket(const char *filename) {
933  int sockfd;
934 
936 
937  char *resolved = resolve_tilde(filename);
938  DLOG("Creating IPC-socket at %s\n", resolved);
939  char *copy = sstrdup(resolved);
940  const char *dir = dirname(copy);
941  if (!path_exists(dir))
942  mkdirp(dir);
943  free(copy);
944 
945  /* Unlink the unix domain socket before */
946  unlink(resolved);
947 
948  if ((sockfd = socket(AF_LOCAL, SOCK_STREAM, 0)) < 0) {
949  perror("socket()");
950  free(resolved);
951  return -1;
952  }
953 
954  (void)fcntl(sockfd, F_SETFD, FD_CLOEXEC);
955 
956  struct sockaddr_un addr;
957  memset(&addr, 0, sizeof(struct sockaddr_un));
958  addr.sun_family = AF_LOCAL;
959  strncpy(addr.sun_path, resolved, sizeof(addr.sun_path) - 1);
960  if (bind(sockfd, (struct sockaddr*)&addr, sizeof(struct sockaddr_un)) < 0) {
961  perror("bind()");
962  free(resolved);
963  return -1;
964  }
965 
966  set_nonblock(sockfd);
967 
968  if (listen(sockfd, 5) < 0) {
969  perror("listen()");
970  free(resolved);
971  return -1;
972  }
973 
974  current_socketpath = resolved;
975  return sockfd;
976 }