/* * vim:ts=8:expandtab * * i3 - an improved dynamic tiling window manager * * © 2009 Michael Stapelberg and contributors * * See file LICENSE for license information. * * ipc.c: Everything about the UNIX domain sockets for IPC * */ #include #include #include #include #include #include #include #include #include #include #include #include #include "queue.h" #include "i3/ipc.h" #include "i3.h" #include "util.h" #include "commands.h" #include "log.h" typedef struct ipc_client { int fd; TAILQ_ENTRY(ipc_client) clients; } ipc_client; TAILQ_HEAD(ipc_client_head, ipc_client) all_clients = TAILQ_HEAD_INITIALIZER(all_clients); /* * Puts the given socket file descriptor into non-blocking mode or dies if * setting O_NONBLOCK failed. Non-blocking sockets are a good idea for our * IPC model because we should by no means block the window manager. * */ static void set_nonblock(int sockfd) { int flags = fcntl(sockfd, F_GETFL, 0); flags |= O_NONBLOCK; if (fcntl(sockfd, F_SETFL, flags) < 0) err(-1, "Could not set O_NONBLOCK"); } #if 0 void broadcast(EV_P_ struct ev_timer *t, int revents) { ipc_client *current; TAILQ_FOREACH(current, &all_clients, clients) { write(current->fd, "hi there!\n", strlen("hi there!\n")); } } #endif /* * Decides what to do with the received message. * * message is the raw packet, as received from the UNIX domain socket. size * is the remaining size of bytes for this packet. * * message_size is the size of the message as the sender specified it. * message_type is the type of the message as the sender specified it. * */ static void ipc_handle_message(uint8_t *message, int size, uint32_t message_size, uint32_t message_type) { DLOG("handling message of size %d\n", size); DLOG("sender specified size %d\n", message_size); DLOG("sender specified type %d\n", message_type); DLOG("payload as a string = %s\n", message); switch (message_type) { case I3_IPC_MESSAGE_TYPE_COMMAND: { /* To get a properly terminated buffer, we copy * message_size bytes out of the buffer */ char *command = scalloc(message_size); strncpy(command, (const char*)message, message_size); parse_command(global_conn, (const char*)command); free(command); break; } default: DLOG("unhandled ipc message\n"); break; } } /* * Handler for activity on a client connection, receives a message from a * client. * * For now, the maximum message size is 2048. I’m not sure for what the * IPC interface will be used in the future, thus I’m not implementing a * mechanism for arbitrarily long messages, as it seems like overkill * at the moment. * */ static void ipc_receive_message(EV_P_ struct ev_io *w, int revents) { char buf[2048]; int n = read(w->fd, buf, sizeof(buf)); /* On error or an empty message, we close the connection */ if (n <= 0) { #if 0 /* FIXME: I get these when closing a client socket, * therefore we just treat them as an error. Is this * correct? */ if (errno == EAGAIN || errno == EWOULDBLOCK) return; #endif /* If not, there was some kind of error. We don’t bother * and close the connection */ close(w->fd); /* Delete the client from the list of clients */ struct ipc_client *current; TAILQ_FOREACH(current, &all_clients, clients) { if (current->fd != w->fd) continue; /* We can call TAILQ_REMOVE because we break out of the * TAILQ_FOREACH afterwards */ TAILQ_REMOVE(&all_clients, current, clients); break; } ev_io_stop(EV_A_ w); DLOG("IPC: client disconnected\n"); return; } /* Terminate the message correctly */ buf[n] = '\0'; /* Check if the message starts with the i3 IPC magic code */ if (n < strlen(I3_IPC_MAGIC)) { DLOG("IPC: message too short, ignoring\n"); return; } if (strncmp(buf, I3_IPC_MAGIC, strlen(I3_IPC_MAGIC)) != 0) { DLOG("IPC: message does not start with the IPC magic\n"); return; } uint8_t *message = (uint8_t*)buf; while (n > 0) { DLOG("IPC: n = %d\n", n); message += strlen(I3_IPC_MAGIC); n -= strlen(I3_IPC_MAGIC); /* The next 32 bit after the magic are the message size */ uint32_t message_size = *((uint32_t*)message); message += sizeof(uint32_t); n -= sizeof(uint32_t); if (message_size > n) { DLOG("IPC: Either the message size was wrong or the message was not read completely, dropping\n"); return; } /* The last 32 bits of the header are the message type */ uint32_t message_type = *((uint32_t*)message); message += sizeof(uint32_t); n -= sizeof(uint32_t); ipc_handle_message(message, n, message_size, message_type); n -= message_size; message += message_size; } } /* * Handler for activity on the listening socket, meaning that a new client * has just connected and we should accept() him. Sets up the event handler * for activity on the new connection and inserts the file descriptor into * the list of clients. * */ void ipc_new_client(EV_P_ struct ev_io *w, int revents) { struct sockaddr_un peer; socklen_t len = sizeof(struct sockaddr_un); int client; if ((client = accept(w->fd, (struct sockaddr*)&peer, &len)) < 0) { if (errno == EINTR) return; else perror("accept()"); return; } set_nonblock(client); struct ev_io *package = calloc(sizeof(struct ev_io), 1); ev_io_init(package, ipc_receive_message, client, EV_READ); ev_io_start(EV_A_ package); DLOG("IPC: new client connected\n"); struct ipc_client *new = calloc(sizeof(struct ipc_client), 1); new->fd = client; TAILQ_INSERT_TAIL(&all_clients, new, clients); } /* * Creates the UNIX domain socket at the given path, sets it to non-blocking * mode, bind()s and listen()s on it. * */ int ipc_create_socket(const char *filename) { int sockfd; /* Unlink the unix domain socket before */ unlink(filename); if ((sockfd = socket(AF_LOCAL, SOCK_STREAM, 0)) < 0) { perror("socket()"); return -1; } (void)fcntl(sockfd, F_SETFD, FD_CLOEXEC); struct sockaddr_un addr; memset(&addr, 0, sizeof(struct sockaddr_un)); addr.sun_family = AF_LOCAL; strcpy(addr.sun_path, filename); if (bind(sockfd, (struct sockaddr*)&addr, sizeof(struct sockaddr_un)) < 0) { perror("bind()"); return -1; } set_nonblock(sockfd); if (listen(sockfd, 5) < 0) { perror("listen()"); return -1; } return sockfd; }