1 /* $NetBSD: unix_dgram_listen.c,v 1.3 2022/10/08 16:12:50 christos Exp $ */
2
3 /*++
4 /* NAME
5 /* unix_dgram_listen 3
6 /* SUMMARY
7 /* listen to UNIX-domain datagram server
8 /* SYNOPSIS
9 /* #include <listen.h>
10 /*
11 /* int unix_dgram_listen(
12 /* const char *path,
13 /* int block_mode)
14 /* DESCRIPTION
15 /* unix_dgram_listen() binds to the specified UNIX-domain
16 /* datagram endpoint, and returns the resulting file descriptor.
17 /*
18 /* Arguments:
19 /* .IP path
20 /* Null-terminated string with connection destination.
21 /* .IP backlog
22 /* Either NON_BLOCKING for a non-blocking socket, or BLOCKING for
23 /* blocking mode.
24 /* DIAGNOSTICS
25 /* Fatal errors: path too large, can't create socket.
26 /* LICENSE
27 /* .ad
28 /* .fi
29 /* The Secure Mailer license must be distributed with this software.
30 /* AUTHOR(S)
31 /* Wietse Venema
32 /* Google, Inc.
33 /* 111 8th Avenue
34 /* New York, NY 10011, USA
35 /*--*/
36
37 /*
38 * System library.
39 */
40 #include <sys_defs.h>
41 #include <sys/socket.h>
42 #include <sys/un.h>
43 #include <sys/stat.h>
44 #include <unistd.h>
45 #include <string.h>
46 #include <errno.h>
47
48 /*
49 * Utility library.
50 */
51 #include <iostuff.h>
52 #include <listen.h>
53 #include <msg.h>
54
55 /* unix_dgram_listen - bind to UNIX-domain datagram endpoint */
56
unix_dgram_listen(const char * path,int block_mode)57 int unix_dgram_listen(const char *path, int block_mode)
58 {
59 const char myname[] = "unix_dgram_listen";
60 #undef sun
61 struct sockaddr_un sun;
62 ssize_t path_len;
63 int sock;
64
65 /*
66 * Translate address information to internal form.
67 */
68 if ((path_len = strlen(path)) >= sizeof(sun.sun_path))
69 msg_fatal("%s: unix-domain name too long: %s", myname, path);
70 memset((void *) &sun, 0, sizeof(sun));
71 sun.sun_family = AF_UNIX;
72 #ifdef HAS_SUN_LEN
73 sun.sun_len = path_len + 1;
74 #endif
75 memcpy(sun.sun_path, path, path_len + 1);
76
77 /*
78 * Create a 'server' socket.
79 */
80 if ((sock = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0)
81 msg_fatal("%s: socket: %m", myname);
82 if (unlink(path) < 0 && errno != ENOENT)
83 msg_fatal( "remove %s: %m", path);
84 if (bind(sock, (struct sockaddr *) & sun, sizeof(sun)) < 0)
85 msg_fatal( "bind: %s: %m", path);
86 #ifdef FCHMOD_UNIX_SOCKETS
87 if (fchmod(sock, 0666) < 0)
88 msg_fatal("fchmod socket %s: %m", path);
89 #else
90 if (chmod(path, 0666) < 0)
91 msg_fatal("chmod socket %s: %m", path);
92 #endif
93 non_blocking(sock, block_mode);
94 return (sock);
95 }
96