1 /* $NetBSD: unix_listen.c,v 1.2 2017/02/14 01:16:49 christos Exp $ */
2
3 /*++
4 /* NAME
5 /* unix_listen 3
6 /* SUMMARY
7 /* start UNIX-domain listener
8 /* SYNOPSIS
9 /* #include <listen.h>
10 /*
11 /* int unix_listen(addr, backlog, block_mode)
12 /* const char *addr;
13 /* int backlog;
14 /* int block_mode;
15 /*
16 /* int unix_accept(fd)
17 /* int fd;
18 /* DESCRIPTION
19 /* The \fBunix_listen\fR() routine starts a listener in the UNIX domain
20 /* on the specified address, with the specified backlog, and returns
21 /* the resulting file descriptor.
22 /*
23 /* unix_accept() accepts a connection and sanitizes error results.
24 /*
25 /* Arguments:
26 /* .IP addr
27 /* Null-terminated string with connection destination.
28 /* .IP backlog
29 /* This argument is passed on to the \fIlisten(2)\fR routine.
30 /* .IP block_mode
31 /* Either NON_BLOCKING for a non-blocking socket, or BLOCKING for
32 /* blocking mode.
33 /* .IP fd
34 /* File descriptor returned by unix_listen().
35 /* DIAGNOSTICS
36 /* Fatal errors: unix_listen() aborts upon any system call failure.
37 /* unix_accept() leaves all error handling up to the caller.
38 /* LICENSE
39 /* .ad
40 /* .fi
41 /* The Secure Mailer license must be distributed with this software.
42 /* AUTHOR(S)
43 /* Wietse Venema
44 /* IBM T.J. Watson Research
45 /* P.O. Box 704
46 /* Yorktown Heights, NY 10598, USA
47 /*--*/
48
49 /* System interfaces. */
50
51 #include <sys_defs.h>
52 #include <sys/socket.h>
53 #include <sys/un.h>
54 #include <string.h>
55 #include <unistd.h>
56 #include <sys/stat.h>
57 #include <errno.h>
58
59 /* Utility library. */
60
61 #include "msg.h"
62 #include "iostuff.h"
63 #include "listen.h"
64 #include "sane_accept.h"
65
66 /* unix_listen - create UNIX-domain listener */
67
unix_listen(const char * addr,int backlog,int block_mode)68 int unix_listen(const char *addr, int backlog, int block_mode)
69 {
70 #undef sun
71 struct sockaddr_un sun;
72 ssize_t len = strlen(addr);
73 int sock;
74
75 /*
76 * Translate address information to internal form.
77 */
78 if (len >= sizeof(sun.sun_path))
79 msg_fatal("unix-domain name too long: %s", addr);
80 memset((void *) &sun, 0, sizeof(sun));
81 sun.sun_family = AF_UNIX;
82 #ifdef HAS_SUN_LEN
83 sun.sun_len = len + 1;
84 #endif
85 memcpy(sun.sun_path, addr, len + 1);
86
87 /*
88 * Create a listener socket. Do whatever we can so we don't run into
89 * trouble when this process is restarted after crash.
90 */
91 if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
92 msg_fatal("socket: %m");
93 if (unlink(addr) < 0 && errno != ENOENT)
94 msg_fatal("remove %s: %m", addr);
95 if (bind(sock, (struct sockaddr *) &sun, sizeof(sun)) < 0)
96 msg_fatal("bind: %s: %m", addr);
97 #ifdef FCHMOD_UNIX_SOCKETS
98 if (fchmod(sock, 0666) < 0)
99 msg_fatal("fchmod socket %s: %m", addr);
100 #else
101 if (chmod(addr, 0666) < 0)
102 msg_fatal("chmod socket %s: %m", addr);
103 #endif
104 non_blocking(sock, block_mode);
105 if (listen(sock, backlog) < 0)
106 msg_fatal("listen: %m");
107 return (sock);
108 }
109
110 /* unix_accept - accept connection */
111
unix_accept(int fd)112 int unix_accept(int fd)
113 {
114 return (sane_accept(fd, (struct sockaddr *) 0, (SOCKADDR_SIZE *) 0));
115 }
116