4 * i3 - an improved dynamic tiling window manager
6 * © 2009-2010 Michael Stapelberg and contributors
8 * See file LICENSE for license information.
10 * ipc.c: Everything about the UNIX domain sockets for IPC
13 #include <sys/socket.h>
17 #include <yajl/yajl_gen.h>
18 #include <yajl/yajl_parse.h>
22 /* Shorter names for all those yajl_gen_* functions */
23 #define y(x, ...) yajl_gen_ ## x (gen, ##__VA_ARGS__)
24 #define ystr(str) yajl_gen_string(gen, (unsigned char*)str, strlen(str))
26 TAILQ_HEAD(ipc_client_head, ipc_client) all_clients = TAILQ_HEAD_INITIALIZER(all_clients);
29 * Puts the given socket file descriptor into non-blocking mode or dies if
30 * setting O_NONBLOCK failed. Non-blocking sockets are a good idea for our
31 * IPC model because we should by no means block the window manager.
34 static void set_nonblock(int sockfd) {
35 int flags = fcntl(sockfd, F_GETFL, 0);
37 if (fcntl(sockfd, F_SETFL, flags) < 0)
38 err(-1, "Could not set O_NONBLOCK");
41 static void ipc_send_message(int fd, const unsigned char *payload,
42 int message_type, int message_size) {
43 int buffer_size = strlen("i3-ipc") + sizeof(uint32_t) +
44 sizeof(uint32_t) + message_size;
45 char msg[buffer_size];
48 strcpy(walk, "i3-ipc");
49 walk += strlen("i3-ipc");
50 memcpy(walk, &message_size, sizeof(uint32_t));
51 walk += sizeof(uint32_t);
52 memcpy(walk, &message_type, sizeof(uint32_t));
53 walk += sizeof(uint32_t);
54 memcpy(walk, payload, message_size);
57 int bytes_to_go = buffer_size;
58 while (sent_bytes < bytes_to_go) {
59 int n = write(fd, msg + sent_bytes, bytes_to_go);
61 DLOG("write() failed: %s\n", strerror(errno));
71 * Sends the specified event to all IPC clients which are currently connected
72 * and subscribed to this kind of event.
75 void ipc_send_event(const char *event, uint32_t message_type, const char *payload) {
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)
89 ipc_send_message(current->fd, (const unsigned char*)payload,
90 message_type, strlen(payload));
95 * Calls shutdown() on each socket and closes it. This function to be called
96 * when exiting or restarting only!
101 TAILQ_FOREACH(current, &all_clients, clients) {
102 shutdown(current->fd, SHUT_RDWR);
108 * Executes the command and returns whether it could be successfully parsed
109 * or not (at the moment, always returns true).
112 IPC_HANDLER(command) {
113 /* To get a properly terminated buffer, we copy
114 * message_size bytes out of the buffer */
115 char *command = scalloc(message_size);
116 strncpy(command, (const char*)message, message_size);
117 parse_cmd((const char*)command);
120 /* For now, every command gets a positive acknowledge
121 * (will change with the new command parser) */
122 const char *reply = "{\"success\":true}";
123 ipc_send_message(fd, (const unsigned char*)reply,
124 I3_IPC_REPLY_TYPE_COMMAND, strlen(reply));
127 void dump_node(yajl_gen gen, struct Con *con, bool inplace_restart) {
130 y(integer, (long int)con);
133 y(integer, con->type);
136 y(integer, con->orientation);
139 y(integer, con->layout);
144 y(integer, con->rect.x);
146 y(integer, con->rect.y);
148 y(integer, con->rect.width);
150 y(integer, con->rect.height);
158 y(integer, con->window->id);
164 TAILQ_FOREACH(leaf, &(con->nodes_head), nodes) {
165 dump_node(gen, leaf, inplace_restart);
171 TAILQ_FOREACH(leaf, &(con->nodes_head), nodes) {
172 y(integer, (long int)leaf);
176 ystr("fullscreen_mode");
177 y(integer, con->fullscreen_mode);
179 if (inplace_restart) {
180 if (con->window != NULL) {
185 y(integer, con->window->id);
196 yajl_gen gen = yajl_gen_alloc(NULL, NULL);
197 dump_node(gen, croot, false);
199 const unsigned char *payload;
201 y(get_buf, &payload, &length);
203 ipc_send_message(fd, payload, I3_IPC_REPLY_TYPE_TREE, length);
210 * Formats the reply message for a GET_WORKSPACES request and sends it to the
214 IPC_HANDLER(get_workspaces) {
217 Client *last_focused = SLIST_FIRST(&(c_ws->focus_stack));
218 if (last_focused == SLIST_END(&(c_ws->focus_stack)))
221 yajl_gen gen = yajl_gen_alloc(NULL, NULL);
224 TAILQ_FOREACH(ws, workspaces, workspaces) {
225 if (ws->output == NULL)
230 y(integer, ws->num + 1);
236 y(bool, ws->output->current_workspace == ws);
244 y(integer, ws->rect.x);
246 y(integer, ws->rect.y);
248 y(integer, ws->rect.width);
250 y(integer, ws->rect.height);
254 ystr(ws->output->name);
264 const unsigned char *payload;
266 y(get_buf, &payload, &length);
268 ipc_send_message(fd, payload, I3_IPC_REPLY_TYPE_WORKSPACES, length);
273 * Formats the reply message for a GET_OUTPUTS request and sends it to the
277 IPC_HANDLER(get_outputs) {
280 yajl_gen gen = yajl_gen_alloc(NULL, NULL);
283 TAILQ_FOREACH(output, &outputs, outputs) {
290 y(bool, output->active);
295 y(integer, output->rect.x);
297 y(integer, output->rect.y);
299 y(integer, output->rect.width);
301 y(integer, output->rect.height);
304 ystr("current_workspace");
305 if (output->current_workspace == NULL)
307 else y(integer, output->current_workspace->num + 1);
314 const unsigned char *payload;
316 y(get_buf, &payload, &length);
318 ipc_send_message(fd, payload, I3_IPC_REPLY_TYPE_OUTPUTS, length);
323 * Callback for the YAJL parser (will be called when a string is parsed).
326 static int add_subscription(void *extra, const unsigned char *s,
328 ipc_client *client = extra;
330 DLOG("should add subscription to extra %p, sub %.*s\n", client, len, s);
331 int event = client->num_events;
333 client->num_events++;
334 client->events = realloc(client->events, client->num_events * sizeof(char*));
335 /* We copy the string because it is not null-terminated and strndup()
336 * is missing on some BSD systems */
337 client->events[event] = scalloc(len+1);
338 memcpy(client->events[event], s, len);
340 DLOG("client is now subscribed to:\n");
341 for (int i = 0; i < client->num_events; i++)
342 DLOG("event %s\n", client->events[i]);
349 * Subscribes this connection to the event types which were given as a JSON
350 * serialized array in the payload field of the message.
353 IPC_HANDLER(subscribe) {
355 yajl_callbacks callbacks;
357 ipc_client *current, *client = NULL;
359 /* Search the ipc_client structure for this connection */
360 TAILQ_FOREACH(current, &all_clients, clients) {
361 if (current->fd != fd)
368 if (client == NULL) {
369 ELOG("Could not find ipc_client data structure for fd %d\n", fd);
373 /* Setup the JSON parser */
374 memset(&callbacks, 0, sizeof(yajl_callbacks));
375 callbacks.yajl_string = add_subscription;
377 p = yajl_alloc(&callbacks, NULL, NULL, (void*)client);
378 stat = yajl_parse(p, (const unsigned char*)message, message_size);
379 if (stat != yajl_status_ok) {
381 err = yajl_get_error(p, true, (const unsigned char*)message,
383 ELOG("YAJL parse error: %s\n", err);
384 yajl_free_error(p, err);
386 const char *reply = "{\"success\":false}";
387 ipc_send_message(fd, (const unsigned char*)reply,
388 I3_IPC_REPLY_TYPE_SUBSCRIBE, strlen(reply));
393 const char *reply = "{\"success\":true}";
394 ipc_send_message(fd, (const unsigned char*)reply,
395 I3_IPC_REPLY_TYPE_SUBSCRIBE, strlen(reply));
399 /* The index of each callback function corresponds to the numeric
400 * value of the message type (see include/i3/ipc.h) */
401 handler_t handlers[2] = {
407 * Handler for activity on a client connection, receives a message from a
410 * For now, the maximum message size is 2048. I’m not sure for what the
411 * IPC interface will be used in the future, thus I’m not implementing a
412 * mechanism for arbitrarily long messages, as it seems like overkill
416 static void ipc_receive_message(EV_P_ struct ev_io *w, int revents) {
418 int n = read(w->fd, buf, sizeof(buf));
420 /* On error or an empty message, we close the connection */
423 /* FIXME: I get these when closing a client socket,
424 * therefore we just treat them as an error. Is this
426 if (errno == EAGAIN || errno == EWOULDBLOCK)
430 /* If not, there was some kind of error. We don’t bother
431 * and close the connection */
434 /* Delete the client from the list of clients */
436 TAILQ_FOREACH(current, &all_clients, clients) {
437 if (current->fd != w->fd)
440 for (int i = 0; i < current->num_events; i++)
441 free(current->events[i]);
442 /* We can call TAILQ_REMOVE because we break out of the
443 * TAILQ_FOREACH afterwards */
444 TAILQ_REMOVE(&all_clients, current, clients);
450 DLOG("IPC: client disconnected\n");
454 /* Terminate the message correctly */
457 /* Check if the message starts with the i3 IPC magic code */
458 if (n < strlen(I3_IPC_MAGIC)) {
459 DLOG("IPC: message too short, ignoring\n");
463 if (strncmp(buf, I3_IPC_MAGIC, strlen(I3_IPC_MAGIC)) != 0) {
464 DLOG("IPC: message does not start with the IPC magic\n");
468 uint8_t *message = (uint8_t*)buf;
470 DLOG("IPC: n = %d\n", n);
471 message += strlen(I3_IPC_MAGIC);
472 n -= strlen(I3_IPC_MAGIC);
474 /* The next 32 bit after the magic are the message size */
475 uint32_t message_size = *((uint32_t*)message);
476 message += sizeof(uint32_t);
477 n -= sizeof(uint32_t);
479 if (message_size > n) {
480 DLOG("IPC: Either the message size was wrong or the message was not read completely, dropping\n");
484 /* The last 32 bits of the header are the message type */
485 uint32_t message_type = *((uint32_t*)message);
486 message += sizeof(uint32_t);
487 n -= sizeof(uint32_t);
489 if (message_type >= (sizeof(handlers) / sizeof(handler_t)))
490 DLOG("Unhandled message type: %d\n", message_type);
492 handler_t h = handlers[message_type];
493 h(w->fd, message, n, message_size, message_type);
496 message += message_size;
501 * Handler for activity on the listening socket, meaning that a new client
502 * has just connected and we should accept() him. Sets up the event handler
503 * for activity on the new connection and inserts the file descriptor into
504 * the list of clients.
507 void ipc_new_client(EV_P_ struct ev_io *w, int revents) {
508 struct sockaddr_un peer;
509 socklen_t len = sizeof(struct sockaddr_un);
511 if ((client = accept(w->fd, (struct sockaddr*)&peer, &len)) < 0) {
514 else perror("accept()");
518 set_nonblock(client);
520 struct ev_io *package = scalloc(sizeof(struct ev_io));
521 ev_io_init(package, ipc_receive_message, client, EV_READ);
522 ev_io_start(EV_A_ package);
524 DLOG("IPC: new client connected\n");
526 ipc_client *new = scalloc(sizeof(ipc_client));
529 TAILQ_INSERT_TAIL(&all_clients, new, clients);
533 * Creates the UNIX domain socket at the given path, sets it to non-blocking
534 * mode, bind()s and listen()s on it.
537 int ipc_create_socket(const char *filename) {
540 /* Unlink the unix domain socket before */
543 if ((sockfd = socket(AF_LOCAL, SOCK_STREAM, 0)) < 0) {
548 (void)fcntl(sockfd, F_SETFD, FD_CLOEXEC);
550 struct sockaddr_un addr;
551 memset(&addr, 0, sizeof(struct sockaddr_un));
552 addr.sun_family = AF_LOCAL;
553 strcpy(addr.sun_path, filename);
554 if (bind(sockfd, (struct sockaddr*)&addr, sizeof(struct sockaddr_un)) < 0) {
559 set_nonblock(sockfd);
561 if (listen(sockfd, 5) < 0) {