blob: eb2cfea06ad96b491034844626212b49cd736d35 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
|
/*++
/* NAME
/* get_hostname 3
/* SUMMARY
/* network name lookup
/* SYNOPSIS
/* #include <get_hostname.h>
/*
/* const char *get_hostname()
/* DESCRIPTION
/* get_hostname() returns the local hostname as obtained
/* via gethostname() or its moral equivalent. This routine
/* goes to great length to avoid dependencies on any network
/* services.
/* DIAGNOSTICS
/* Fatal errors: no hostname, invalid hostname.
/* SEE ALSO
/* valid_hostname(3)
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <sys/param.h>
#include <string.h>
#include <unistd.h>
#if (MAXHOSTNAMELEN < 256)
#undef MAXHOSTNAMELEN
#define MAXHOSTNAMELEN 256
#endif
/* Utility library. */
#include "mymalloc.h"
#include "msg.h"
#include "valid_hostname.h"
#include "get_hostname.h"
/* Local stuff. */
static char *my_host_name;
/* get_hostname - look up my host name */
const char *get_hostname(void)
{
char namebuf[MAXHOSTNAMELEN + 1];
/*
* The gethostname() call is not (or not yet) in ANSI or POSIX, but it is
* part of the socket interface library. We avoid the more politically-
* correct uname() routine because that has no portable way of dealing
* with long (FQDN) hostnames.
*
* DO NOT CALL GETHOSTBYNAME FROM THIS FUNCTION. IT BREAKS MAILDIR DELIVERY
* AND OTHER THINGS WHEN THE MACHINE NAME IS NOT FOUND IN /ETC/HOSTS OR
* CAUSES PROCESSES TO HANG WHEN THE NETWORK IS DISCONNECTED.
*
* POSTFIX NO LONGER NEEDS A FULLY QUALIFIED HOSTNAME. INSTEAD POSTFIX WILL
* USE A DEFAULT DOMAIN NAME "LOCALDOMAIN".
*/
if (my_host_name == 0) {
/* DO NOT CALL GETHOSTBYNAME FROM THIS FUNCTION */
if (gethostname(namebuf, sizeof(namebuf)) < 0)
msg_fatal("gethostname: %m");
namebuf[MAXHOSTNAMELEN] = 0;
/* DO NOT CALL GETHOSTBYNAME FROM THIS FUNCTION */
if (valid_hostname(namebuf, DO_GRIPE) == 0)
msg_fatal("unable to use my own hostname");
/* DO NOT CALL GETHOSTBYNAME FROM THIS FUNCTION */
my_host_name = mystrdup(namebuf);
}
return (my_host_name);
}
|
