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