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 
14 #include <sys/socket.h>
15 #include <sys/un.h>
16 #include <fcntl.h>
17 #include <libgen.h>
18 #include <ev.h>
19 #include <yajl/yajl_gen.h>
20 #include <yajl/yajl_parse.h>
21 #include <yajl/yajl_version.h>
22 
23 char *current_socketpath = NULL;
24 
25 /* Shorter names for all those yajl_gen_* functions */
26 #define y(x, ...) yajl_gen_ ## x (gen, ##__VA_ARGS__)
27 #define ystr(str) yajl_gen_string(gen, (unsigned char*)str, strlen(str))
28 
29 TAILQ_HEAD(ipc_client_head, ipc_client) all_clients = TAILQ_HEAD_INITIALIZER(all_clients);
30 
31 /*
32  * Puts the given socket file descriptor into non-blocking mode or dies if
33  * setting O_NONBLOCK failed. Non-blocking sockets are a good idea for our
34  * IPC model because we should by no means block the window manager.
35  *
36  */
37 static void set_nonblock(int sockfd) {
38  int flags = fcntl(sockfd, F_GETFL, 0);
39  flags |= O_NONBLOCK;
40  if (fcntl(sockfd, F_SETFL, flags) < 0)
41  err(-1, "Could not set O_NONBLOCK");
42 }
43 
44 /*
45  * Emulates mkdir -p (creates any missing folders)
46  *
47  */
48 static bool mkdirp(const char *path) {
49  if (mkdir(path, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) == 0)
50  return true;
51  if (errno != ENOENT) {
52  ELOG("mkdir(%s) failed: %s\n", path, strerror(errno));
53  return false;
54  }
55  char *copy = strdup(path);
56  /* strip trailing slashes, if any */
57  while (copy[strlen(copy)-1] == '/')
58  copy[strlen(copy)-1] = '\0';
59 
60  char *sep = strrchr(copy, '/');
61  if (sep == NULL) {
62  FREE(copy);
63  return false;
64  }
65  *sep = '\0';
66  bool result = false;
67  if (mkdirp(copy))
68  result = mkdirp(path);
69  free(copy);
70 
71  return result;
72 }
73 
74 /*
75  * Sends the specified event to all IPC clients which are currently connected
76  * and subscribed to this kind of event.
77  *
78  */
79 void ipc_send_event(const char *event, uint32_t message_type, const char *payload) {
80  ipc_client *current;
81  TAILQ_FOREACH(current, &all_clients, clients) {
82  /* see if this client is interested in this event */
83  bool interested = false;
84  for (int i = 0; i < current->num_events; i++) {
85  if (strcasecmp(current->events[i], event) != 0)
86  continue;
87  interested = true;
88  break;
89  }
90  if (!interested)
91  continue;
92 
93  ipc_send_message(current->fd, strlen(payload), message_type, (const uint8_t*)payload);
94  }
95 }
96 
97 /*
98  * Calls shutdown() on each socket and closes it. This function to be called
99  * when exiting or restarting only!
100  *
101  */
102 void ipc_shutdown(void) {
103  ipc_client *current;
104  while (!TAILQ_EMPTY(&all_clients)) {
105  current = TAILQ_FIRST(&all_clients);
106  shutdown(current->fd, SHUT_RDWR);
107  close(current->fd);
108  TAILQ_REMOVE(&all_clients, current, clients);
109  free(current);
110  }
111 }
112 
113 /*
114  * Executes the command and returns whether it could be successfully parsed
115  * or not (at the moment, always returns true).
116  *
117  */
118 IPC_HANDLER(command) {
119  /* To get a properly terminated buffer, we copy
120  * message_size bytes out of the buffer */
121  char *command = scalloc(message_size + 1);
122  strncpy(command, (const char*)message, message_size);
123  LOG("IPC: received: *%s*\n", command);
124  struct CommandResult *command_output = parse_command((const char*)command);
125  free(command);
126 
127  if (command_output->needs_tree_render)
128  tree_render();
129 
130  const unsigned char *reply;
131 #if YAJL_MAJOR >= 2
132  size_t length;
133 #else
134  unsigned int length;
135 #endif
136  yajl_gen_get_buf(command_output->json_gen, &reply, &length);
137 
138  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_COMMAND,
139  (const uint8_t*)reply);
140 
141  yajl_gen_free(command_output->json_gen);
142 }
143 
144 static void dump_rect(yajl_gen gen, const char *name, Rect r) {
145  ystr(name);
146  y(map_open);
147  ystr("x");
148  y(integer, r.x);
149  ystr("y");
150  y(integer, r.y);
151  ystr("width");
152  y(integer, r.width);
153  ystr("height");
154  y(integer, r.height);
155  y(map_close);
156 }
157 
158 void dump_node(yajl_gen gen, struct Con *con, bool inplace_restart) {
159  y(map_open);
160  ystr("id");
161  y(integer, (long int)con);
162 
163  ystr("type");
164  y(integer, con->type);
165 
166  /* provided for backwards compatibility only. */
167  ystr("orientation");
168  if (!con->split)
169  ystr("none");
170  else {
171  if (con_orientation(con) == HORIZ)
172  ystr("horizontal");
173  else ystr("vertical");
174  }
175 
176  ystr("scratchpad_state");
177  switch (con->scratchpad_state) {
178  case SCRATCHPAD_NONE:
179  ystr("none");
180  break;
181  case SCRATCHPAD_FRESH:
182  ystr("fresh");
183  break;
184  case SCRATCHPAD_CHANGED:
185  ystr("changed");
186  break;
187  }
188 
189  ystr("percent");
190  if (con->percent == 0.0)
191  y(null);
192  else y(double, con->percent);
193 
194  ystr("urgent");
195  y(bool, con->urgent);
196 
197  if (con->mark != NULL) {
198  ystr("mark");
199  ystr(con->mark);
200  }
201 
202  ystr("focused");
203  y(bool, (con == focused));
204 
205  ystr("split");
206  y(bool, con->split);
207 
208  ystr("layout");
209  switch (con->layout) {
210  case L_DEFAULT:
211  DLOG("About to dump layout=default, this is a bug in the code.\n");
212  assert(false);
213  break;
214  case L_SPLITV:
215  ystr("splitv");
216  break;
217  case L_SPLITH:
218  ystr("splith");
219  break;
220  case L_STACKED:
221  ystr("stacked");
222  break;
223  case L_TABBED:
224  ystr("tabbed");
225  break;
226  case L_DOCKAREA:
227  ystr("dockarea");
228  break;
229  case L_OUTPUT:
230  ystr("output");
231  break;
232  }
233 
234  ystr("workspace_layout");
235  switch (con->workspace_layout) {
236  case L_DEFAULT:
237  ystr("default");
238  break;
239  case L_STACKED:
240  ystr("stacked");
241  break;
242  case L_TABBED:
243  ystr("tabbed");
244  break;
245  default:
246  DLOG("About to dump workspace_layout=%d (none of default/stacked/tabbed), this is a bug.\n", con->workspace_layout);
247  assert(false);
248  break;
249  }
250 
251  ystr("last_split_layout");
252  switch (con->layout) {
253  case L_SPLITV:
254  ystr("splitv");
255  break;
256  default:
257  ystr("splith");
258  break;
259  }
260 
261  ystr("border");
262  switch (con->border_style) {
263  case BS_NORMAL:
264  ystr("normal");
265  break;
266  case BS_NONE:
267  ystr("none");
268  break;
269  case BS_1PIXEL:
270  ystr("1pixel");
271  break;
272  }
273 
274  dump_rect(gen, "rect", con->rect);
275  dump_rect(gen, "window_rect", con->window_rect);
276  dump_rect(gen, "geometry", con->geometry);
277 
278  ystr("name");
279  if (con->window && con->window->name)
280  ystr(i3string_as_utf8(con->window->name));
281  else
282  ystr(con->name);
283 
284  if (con->type == CT_WORKSPACE) {
285  ystr("num");
286  y(integer, con->num);
287  }
288 
289  ystr("window");
290  if (con->window)
291  y(integer, con->window->id);
292  else y(null);
293 
294  ystr("nodes");
295  y(array_open);
296  Con *node;
297  if (con->type != CT_DOCKAREA || !inplace_restart) {
298  TAILQ_FOREACH(node, &(con->nodes_head), nodes) {
299  dump_node(gen, node, inplace_restart);
300  }
301  }
302  y(array_close);
303 
304  ystr("floating_nodes");
305  y(array_open);
306  TAILQ_FOREACH(node, &(con->floating_head), floating_windows) {
307  dump_node(gen, node, inplace_restart);
308  }
309  y(array_close);
310 
311  ystr("focus");
312  y(array_open);
313  TAILQ_FOREACH(node, &(con->focus_head), focused) {
314  y(integer, (long int)node);
315  }
316  y(array_close);
317 
318  ystr("fullscreen_mode");
319  y(integer, con->fullscreen_mode);
320 
321  ystr("floating");
322  switch (con->floating) {
323  case FLOATING_AUTO_OFF:
324  ystr("auto_off");
325  break;
326  case FLOATING_AUTO_ON:
327  ystr("auto_on");
328  break;
329  case FLOATING_USER_OFF:
330  ystr("user_off");
331  break;
332  case FLOATING_USER_ON:
333  ystr("user_on");
334  break;
335  }
336 
337  ystr("swallows");
338  y(array_open);
339  Match *match;
340  TAILQ_FOREACH(match, &(con->swallow_head), matches) {
341  if (match->dock != -1) {
342  y(map_open);
343  ystr("dock");
344  y(integer, match->dock);
345  ystr("insert_where");
346  y(integer, match->insert_where);
347  y(map_close);
348  }
349 
350  /* TODO: the other swallow keys */
351  }
352 
353  if (inplace_restart) {
354  if (con->window != NULL) {
355  y(map_open);
356  ystr("id");
357  y(integer, con->window->id);
358  ystr("restart_mode");
359  y(bool, true);
360  y(map_close);
361  }
362  }
363  y(array_close);
364 
365  y(map_close);
366 }
367 
368 IPC_HANDLER(tree) {
369  setlocale(LC_NUMERIC, "C");
370 #if YAJL_MAJOR >= 2
371  yajl_gen gen = yajl_gen_alloc(NULL);
372 #else
373  yajl_gen gen = yajl_gen_alloc(NULL, NULL);
374 #endif
375  dump_node(gen, croot, false);
376  setlocale(LC_NUMERIC, "");
377 
378  const unsigned char *payload;
379 #if YAJL_MAJOR >= 2
380  size_t length;
381 #else
382  unsigned int length;
383 #endif
384  y(get_buf, &payload, &length);
385 
386  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_TREE, payload);
387  y(free);
388 }
389 
390 
391 /*
392  * Formats the reply message for a GET_WORKSPACES request and sends it to the
393  * client
394  *
395  */
396 IPC_HANDLER(get_workspaces) {
397 #if YAJL_MAJOR >= 2
398  yajl_gen gen = yajl_gen_alloc(NULL);
399 #else
400  yajl_gen gen = yajl_gen_alloc(NULL, NULL);
401 #endif
402  y(array_open);
403 
404  Con *focused_ws = con_get_workspace(focused);
405 
406  Con *output;
407  TAILQ_FOREACH(output, &(croot->nodes_head), nodes) {
408  if (output->name[0] == '_' && output->name[1] == '_')
409  continue;
410  Con *ws;
411  TAILQ_FOREACH(ws, &(output_get_content(output)->nodes_head), nodes) {
412  assert(ws->type == CT_WORKSPACE);
413  y(map_open);
414 
415  ystr("num");
416  if (ws->num == -1)
417  y(null);
418  else y(integer, ws->num);
419 
420  ystr("name");
421  ystr(ws->name);
422 
423  ystr("visible");
424  y(bool, workspace_is_visible(ws));
425 
426  ystr("focused");
427  y(bool, ws == focused_ws);
428 
429  ystr("rect");
430  y(map_open);
431  ystr("x");
432  y(integer, ws->rect.x);
433  ystr("y");
434  y(integer, ws->rect.y);
435  ystr("width");
436  y(integer, ws->rect.width);
437  ystr("height");
438  y(integer, ws->rect.height);
439  y(map_close);
440 
441  ystr("output");
442  ystr(output->name);
443 
444  ystr("urgent");
445  y(bool, ws->urgent);
446 
447  y(map_close);
448  }
449  }
450 
451  y(array_close);
452 
453  const unsigned char *payload;
454 #if YAJL_MAJOR >= 2
455  size_t length;
456 #else
457  unsigned int length;
458 #endif
459  y(get_buf, &payload, &length);
460 
461  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_WORKSPACES, payload);
462  y(free);
463 }
464 
465 /*
466  * Formats the reply message for a GET_OUTPUTS request and sends it to the
467  * client
468  *
469  */
470 IPC_HANDLER(get_outputs) {
471 #if YAJL_MAJOR >= 2
472  yajl_gen gen = yajl_gen_alloc(NULL);
473 #else
474  yajl_gen gen = yajl_gen_alloc(NULL, NULL);
475 #endif
476  y(array_open);
477 
478  Output *output;
479  TAILQ_FOREACH(output, &outputs, outputs) {
480  y(map_open);
481 
482  ystr("name");
483  ystr(output->name);
484 
485  ystr("active");
486  y(bool, output->active);
487 
488  ystr("primary");
489  y(bool, output->primary);
490 
491  ystr("rect");
492  y(map_open);
493  ystr("x");
494  y(integer, output->rect.x);
495  ystr("y");
496  y(integer, output->rect.y);
497  ystr("width");
498  y(integer, output->rect.width);
499  ystr("height");
500  y(integer, output->rect.height);
501  y(map_close);
502 
503  ystr("current_workspace");
504  Con *ws = NULL;
505  if (output->con && (ws = con_get_fullscreen_con(output->con, CF_OUTPUT)))
506  ystr(ws->name);
507  else y(null);
508 
509  y(map_close);
510  }
511 
512  y(array_close);
513 
514  const unsigned char *payload;
515 #if YAJL_MAJOR >= 2
516  size_t length;
517 #else
518  unsigned int length;
519 #endif
520  y(get_buf, &payload, &length);
521 
522  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_OUTPUTS, payload);
523  y(free);
524 }
525 
526 /*
527  * Formats the reply message for a GET_MARKS request and sends it to the
528  * client
529  *
530  */
531 IPC_HANDLER(get_marks) {
532 #if YAJL_MAJOR >= 2
533  yajl_gen gen = yajl_gen_alloc(NULL);
534 #else
535  yajl_gen gen = yajl_gen_alloc(NULL, NULL);
536 #endif
537  y(array_open);
538 
539  Con *con;
541  if (con->mark != NULL)
542  ystr(con->mark);
543 
544  y(array_close);
545 
546  const unsigned char *payload;
547 #if YAJL_MAJOR >= 2
548  size_t length;
549 #else
550  unsigned int length;
551 #endif
552  y(get_buf, &payload, &length);
553 
554  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_MARKS, payload);
555  y(free);
556 }
557 
558 /*
559  * Returns the version of i3
560  *
561  */
562 IPC_HANDLER(get_version) {
563 #if YAJL_MAJOR >= 2
564  yajl_gen gen = yajl_gen_alloc(NULL);
565 #else
566  yajl_gen gen = yajl_gen_alloc(NULL, NULL);
567 #endif
568  y(map_open);
569 
570  ystr("major");
571  y(integer, MAJOR_VERSION);
572 
573  ystr("minor");
574  y(integer, MINOR_VERSION);
575 
576  ystr("patch");
577  y(integer, PATCH_VERSION);
578 
579  ystr("human_readable");
580  ystr(I3_VERSION);
581 
582  y(map_close);
583 
584  const unsigned char *payload;
585 #if YAJL_MAJOR >= 2
586  size_t length;
587 #else
588  unsigned int length;
589 #endif
590  y(get_buf, &payload, &length);
591 
592  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_VERSION, payload);
593  y(free);
594 }
595 
596 /*
597  * Formats the reply message for a GET_BAR_CONFIG request and sends it to the
598  * client.
599  *
600  */
601 IPC_HANDLER(get_bar_config) {
602 #if YAJL_MAJOR >= 2
603  yajl_gen gen = yajl_gen_alloc(NULL);
604 #else
605  yajl_gen gen = yajl_gen_alloc(NULL, NULL);
606 #endif
607 
608  /* If no ID was passed, we return a JSON array with all IDs */
609  if (message_size == 0) {
610  y(array_open);
611  Barconfig *current;
612  TAILQ_FOREACH(current, &barconfigs, configs) {
613  ystr(current->id);
614  }
615  y(array_close);
616 
617  const unsigned char *payload;
618 #if YAJL_MAJOR >= 2
619  size_t length;
620 #else
621  unsigned int length;
622 #endif
623  y(get_buf, &payload, &length);
624 
625  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_BAR_CONFIG, payload);
626  y(free);
627  return;
628  }
629 
630  /* To get a properly terminated buffer, we copy
631  * message_size bytes out of the buffer */
632  char *bar_id = scalloc(message_size + 1);
633  strncpy(bar_id, (const char*)message, message_size);
634  LOG("IPC: looking for config for bar ID \"%s\"\n", bar_id);
635  Barconfig *current, *config = NULL;
636  TAILQ_FOREACH(current, &barconfigs, configs) {
637  if (strcmp(current->id, bar_id) != 0)
638  continue;
639 
640  config = current;
641  break;
642  }
643 
644  y(map_open);
645 
646  if (!config) {
647  /* If we did not find a config for the given ID, the reply will contain
648  * a null 'id' field. */
649  ystr("id");
650  y(null);
651  } else {
652  ystr("id");
653  ystr(config->id);
654 
655  if (config->num_outputs > 0) {
656  ystr("outputs");
657  y(array_open);
658  for (int c = 0; c < config->num_outputs; c++)
659  ystr(config->outputs[c]);
660  y(array_close);
661  }
662 
663 #define YSTR_IF_SET(name) \
664  do { \
665  if (config->name) { \
666  ystr( # name); \
667  ystr(config->name); \
668  } \
669  } while (0)
670 
671  YSTR_IF_SET(tray_output);
672  YSTR_IF_SET(socket_path);
673 
674  ystr("mode");
675  if (config->mode == M_HIDE)
676  ystr("hide");
677  else ystr("dock");
678 
679  ystr("modifier");
680  switch (config->modifier) {
681  case M_CONTROL:
682  ystr("ctrl");
683  break;
684  case M_SHIFT:
685  ystr("shift");
686  break;
687  case M_MOD1:
688  ystr("Mod1");
689  break;
690  case M_MOD2:
691  ystr("Mod2");
692  break;
693  case M_MOD3:
694  ystr("Mod3");
695  break;
696  /*
697  case M_MOD4:
698  ystr("Mod4");
699  break;
700  */
701  case M_MOD5:
702  ystr("Mod5");
703  break;
704  default:
705  ystr("Mod4");
706  break;
707  }
708 
709  ystr("position");
710  if (config->position == P_BOTTOM)
711  ystr("bottom");
712  else ystr("top");
713 
714  YSTR_IF_SET(status_command);
715  YSTR_IF_SET(font);
716 
717  ystr("workspace_buttons");
718  y(bool, !config->hide_workspace_buttons);
719 
720  ystr("verbose");
721  y(bool, config->verbose);
722 
723 #undef YSTR_IF_SET
724 #define YSTR_IF_SET(name) \
725  do { \
726  if (config->colors.name) { \
727  ystr( # name); \
728  ystr(config->colors.name); \
729  } \
730  } while (0)
731 
732  ystr("colors");
733  y(map_open);
734  YSTR_IF_SET(background);
735  YSTR_IF_SET(statusline);
736  YSTR_IF_SET(focused_workspace_border);
737  YSTR_IF_SET(focused_workspace_bg);
738  YSTR_IF_SET(focused_workspace_text);
739  YSTR_IF_SET(active_workspace_border);
740  YSTR_IF_SET(active_workspace_bg);
741  YSTR_IF_SET(active_workspace_text);
742  YSTR_IF_SET(inactive_workspace_border);
743  YSTR_IF_SET(inactive_workspace_bg);
744  YSTR_IF_SET(inactive_workspace_text);
745  YSTR_IF_SET(urgent_workspace_border);
746  YSTR_IF_SET(urgent_workspace_bg);
747  YSTR_IF_SET(urgent_workspace_text);
748  y(map_close);
749 
750 #undef YSTR_IF_SET
751  }
752 
753  y(map_close);
754 
755  const unsigned char *payload;
756 #if YAJL_MAJOR >= 2
757  size_t length;
758 #else
759  unsigned int length;
760 #endif
761  y(get_buf, &payload, &length);
762 
763  ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_BAR_CONFIG, payload);
764  y(free);
765 }
766 
767 /*
768  * Callback for the YAJL parser (will be called when a string is parsed).
769  *
770  */
771 #if YAJL_MAJOR < 2
772 static int add_subscription(void *extra, const unsigned char *s,
773  unsigned int len) {
774 #else
775 static int add_subscription(void *extra, const unsigned char *s,
776  size_t len) {
777 #endif
778  ipc_client *client = extra;
779 
780  DLOG("should add subscription to extra %p, sub %.*s\n", client, (int)len, s);
781  int event = client->num_events;
782 
783  client->num_events++;
784  client->events = realloc(client->events, client->num_events * sizeof(char*));
785  /* We copy the string because it is not null-terminated and strndup()
786  * is missing on some BSD systems */
787  client->events[event] = scalloc(len+1);
788  memcpy(client->events[event], s, len);
789 
790  DLOG("client is now subscribed to:\n");
791  for (int i = 0; i < client->num_events; i++)
792  DLOG("event %s\n", client->events[i]);
793  DLOG("(done)\n");
794 
795  return 1;
796 }
797 
798 /*
799  * Subscribes this connection to the event types which were given as a JSON
800  * serialized array in the payload field of the message.
801  *
802  */
803 IPC_HANDLER(subscribe) {
804  yajl_handle p;
805  yajl_callbacks callbacks;
806  yajl_status stat;
807  ipc_client *current, *client = NULL;
808 
809  /* Search the ipc_client structure for this connection */
810  TAILQ_FOREACH(current, &all_clients, clients) {
811  if (current->fd != fd)
812  continue;
813 
814  client = current;
815  break;
816  }
817 
818  if (client == NULL) {
819  ELOG("Could not find ipc_client data structure for fd %d\n", fd);
820  return;
821  }
822 
823  /* Setup the JSON parser */
824  memset(&callbacks, 0, sizeof(yajl_callbacks));
825  callbacks.yajl_string = add_subscription;
826 
827 #if YAJL_MAJOR >= 2
828  p = yajl_alloc(&callbacks, NULL, (void*)client);
829 #else
830  p = yajl_alloc(&callbacks, NULL, NULL, (void*)client);
831 #endif
832  stat = yajl_parse(p, (const unsigned char*)message, message_size);
833  if (stat != yajl_status_ok) {
834  unsigned char *err;
835  err = yajl_get_error(p, true, (const unsigned char*)message,
836  message_size);
837  ELOG("YAJL parse error: %s\n", err);
838  yajl_free_error(p, err);
839 
840  const char *reply = "{\"success\":false}";
841  ipc_send_message(fd, strlen(reply), I3_IPC_REPLY_TYPE_SUBSCRIBE, (const uint8_t*)reply);
842  yajl_free(p);
843  return;
844  }
845  yajl_free(p);
846  const char *reply = "{\"success\":true}";
847  ipc_send_message(fd, strlen(reply), I3_IPC_REPLY_TYPE_SUBSCRIBE, (const uint8_t*)reply);
848 }
849 
850 /* The index of each callback function corresponds to the numeric
851  * value of the message type (see include/i3/ipc.h) */
853  handle_command,
854  handle_get_workspaces,
855  handle_subscribe,
856  handle_get_outputs,
857  handle_tree,
858  handle_get_marks,
859  handle_get_bar_config,
860  handle_get_version,
861 };
862 
863 /*
864  * Handler for activity on a client connection, receives a message from a
865  * client.
866  *
867  * For now, the maximum message size is 2048. I’m not sure for what the
868  * IPC interface will be used in the future, thus I’m not implementing a
869  * mechanism for arbitrarily long messages, as it seems like overkill
870  * at the moment.
871  *
872  */
873 static void ipc_receive_message(EV_P_ struct ev_io *w, int revents) {
874  char buf[2048];
875  int n = read(w->fd, buf, sizeof(buf));
876 
877  /* On error or an empty message, we close the connection */
878  if (n <= 0) {
879 #if 0
880  /* FIXME: I get these when closing a client socket,
881  * therefore we just treat them as an error. Is this
882  * correct? */
883  if (errno == EAGAIN || errno == EWOULDBLOCK)
884  return;
885 #endif
886 
887  /* If not, there was some kind of error. We don’t bother
888  * and close the connection */
889  close(w->fd);
890 
891  /* Delete the client from the list of clients */
892  ipc_client *current;
893  TAILQ_FOREACH(current, &all_clients, clients) {
894  if (current->fd != w->fd)
895  continue;
896 
897  for (int i = 0; i < current->num_events; i++)
898  free(current->events[i]);
899  /* We can call TAILQ_REMOVE because we break out of the
900  * TAILQ_FOREACH afterwards */
901  TAILQ_REMOVE(&all_clients, current, clients);
902  free(current);
903  break;
904  }
905 
906  ev_io_stop(EV_A_ w);
907  free(w);
908 
909  DLOG("IPC: client disconnected\n");
910  return;
911  }
912 
913  /* Terminate the message correctly */
914  buf[n] = '\0';
915 
916  /* Check if the message starts with the i3 IPC magic code */
917  if (n < strlen(I3_IPC_MAGIC)) {
918  DLOG("IPC: message too short, ignoring\n");
919  return;
920  }
921 
922  if (strncmp(buf, I3_IPC_MAGIC, strlen(I3_IPC_MAGIC)) != 0) {
923  DLOG("IPC: message does not start with the IPC magic\n");
924  return;
925  }
926 
927  uint8_t *message = (uint8_t*)buf;
928  while (n > 0) {
929  DLOG("IPC: n = %d\n", n);
930  message += strlen(I3_IPC_MAGIC);
931  n -= strlen(I3_IPC_MAGIC);
932 
933  /* The next 32 bit after the magic are the message size */
934  uint32_t message_size;
935  memcpy(&message_size, (uint32_t*)message, sizeof(uint32_t));
936  message += sizeof(uint32_t);
937  n -= sizeof(uint32_t);
938 
939  if (message_size > n) {
940  DLOG("IPC: Either the message size was wrong or the message was not read completely, dropping\n");
941  return;
942  }
943 
944  /* The last 32 bits of the header are the message type */
945  uint32_t message_type;
946  memcpy(&message_type, (uint32_t*)message, sizeof(uint32_t));
947  message += sizeof(uint32_t);
948  n -= sizeof(uint32_t);
949 
950  if (message_type >= (sizeof(handlers) / sizeof(handler_t)))
951  DLOG("Unhandled message type: %d\n", message_type);
952  else {
953  handler_t h = handlers[message_type];
954  h(w->fd, message, n, message_size, message_type);
955  }
956  n -= message_size;
957  message += message_size;
958  }
959 }
960 
961 /*
962  * Handler for activity on the listening socket, meaning that a new client
963  * has just connected and we should accept() him. Sets up the event handler
964  * for activity on the new connection and inserts the file descriptor into
965  * the list of clients.
966  *
967  */
968 void ipc_new_client(EV_P_ struct ev_io *w, int revents) {
969  struct sockaddr_un peer;
970  socklen_t len = sizeof(struct sockaddr_un);
971  int client;
972  if ((client = accept(w->fd, (struct sockaddr*)&peer, &len)) < 0) {
973  if (errno == EINTR)
974  return;
975  else perror("accept()");
976  return;
977  }
978 
979  /* Close this file descriptor on exec() */
980  (void)fcntl(client, F_SETFD, FD_CLOEXEC);
981 
982  set_nonblock(client);
983 
984  struct ev_io *package = scalloc(sizeof(struct ev_io));
985  ev_io_init(package, ipc_receive_message, client, EV_READ);
986  ev_io_start(EV_A_ package);
987 
988  DLOG("IPC: new client connected on fd %d\n", w->fd);
989 
990  ipc_client *new = scalloc(sizeof(ipc_client));
991  new->fd = client;
992 
993  TAILQ_INSERT_TAIL(&all_clients, new, clients);
994 }
995 
996 /*
997  * Creates the UNIX domain socket at the given path, sets it to non-blocking
998  * mode, bind()s and listen()s on it.
999  *
1000  */
1001 int ipc_create_socket(const char *filename) {
1002  int sockfd;
1003 
1005 
1006  char *resolved = resolve_tilde(filename);
1007  DLOG("Creating IPC-socket at %s\n", resolved);
1008  char *copy = sstrdup(resolved);
1009  const char *dir = dirname(copy);
1010  if (!path_exists(dir))
1011  mkdirp(dir);
1012  free(copy);
1013 
1014  /* Unlink the unix domain socket before */
1015  unlink(resolved);
1016 
1017  if ((sockfd = socket(AF_LOCAL, SOCK_STREAM, 0)) < 0) {
1018  perror("socket()");
1019  free(resolved);
1020  return -1;
1021  }
1022 
1023  (void)fcntl(sockfd, F_SETFD, FD_CLOEXEC);
1024 
1025  struct sockaddr_un addr;
1026  memset(&addr, 0, sizeof(struct sockaddr_un));
1027  addr.sun_family = AF_LOCAL;
1028  strncpy(addr.sun_path, resolved, sizeof(addr.sun_path) - 1);
1029  if (bind(sockfd, (struct sockaddr*)&addr, sizeof(struct sockaddr_un)) < 0) {
1030  perror("bind()");
1031  free(resolved);
1032  return -1;
1033  }
1034 
1035  set_nonblock(sockfd);
1036 
1037  if (listen(sockfd, 5) < 0) {
1038  perror("listen()");
1039  free(resolved);
1040  return -1;
1041  }
1042 
1043  current_socketpath = resolved;
1044  return sockfd;
1045 }