/* Example of Local-Namespace Sockets Copyright (C) 1991-2016 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, if not, see <http://www.gnu.org/licenses/>. */ #include <stddef.h> #include <stdio.h> #include <errno.h> #include <stdlib.h> #include <string.h> #include <sys/socket.h> #include <sys/un.h> int make_named_socket (const char *filename) { struct sockaddr_un name; int sock; size_t size; /* Create the socket. */ sock = socket (PF_LOCAL, SOCK_DGRAM, 0); if (sock < 0) { perror ("socket"); exit (EXIT_FAILURE); } /* Bind a name to the socket. */ name.sun_family = AF_LOCAL; strncpy (name.sun_path, filename, sizeof (name.sun_path)); name.sun_path[sizeof (name.sun_path) - 1] = '\0'; /* The size of the address is the offset of the start of the filename, plus its length (not including the terminating null byte). Alternatively you can just do: size = SUN_LEN (&name); */ size = (offsetof (struct sockaddr_un, sun_path) + strlen (name.sun_path)); if (bind (sock, (struct sockaddr *) &name, size) < 0) { perror ("bind"); exit (EXIT_FAILURE); } return sock; }