mirror of
https://github.com/sheumann/hush.git
synced 2024-12-21 23:29:34 +00:00
54 lines
1.8 KiB
C
54 lines
1.8 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* Safe gethostname implementation for busybox
|
|
*
|
|
* Copyright (C) 2008 Tito Ragusa <farmatito@tiscali.it>
|
|
*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
|
|
*/
|
|
|
|
/*
|
|
* SUSv2 guarantees that "Host names are limited to 255 bytes"
|
|
* POSIX.1-2001 guarantees that "Host names (not including the terminating
|
|
* null byte) are limited to HOST_NAME_MAX bytes" (64 bytes on my box).
|
|
*
|
|
* RFC1123 says:
|
|
*
|
|
* The syntax of a legal Internet host name was specified in RFC-952
|
|
* [DNS:4]. One aspect of host name syntax is hereby changed: the
|
|
* restriction on the first character is relaxed to allow either a
|
|
* letter or a digit. Host software MUST support this more liberal
|
|
* syntax.
|
|
*
|
|
* Host software MUST handle host names of up to 63 characters and
|
|
* SHOULD handle host names of up to 255 characters.
|
|
*/
|
|
|
|
#include "libbb.h"
|
|
#include <sys/utsname.h>
|
|
|
|
/*
|
|
* On success return the current malloced and NUL terminated hostname.
|
|
* On error return malloced and NUL terminated string "?".
|
|
* This is an illegal first character for a hostname.
|
|
* The returned malloced string must be freed by the caller.
|
|
*/
|
|
char *safe_gethostname(void)
|
|
{
|
|
struct utsname uts;
|
|
|
|
/* The length of the arrays in a struct utsname is unspecified;
|
|
* the fields are terminated by a null byte.
|
|
* Note that there is no standard that says that the hostname
|
|
* set by sethostname(2) is the same string as the nodename field of the
|
|
* struct returned by uname (indeed, some systems allow a 256-byte host-
|
|
* name and an 8-byte nodename), but this is true on Linux. The same holds
|
|
* for setdomainname(2) and the domainname field.
|
|
*/
|
|
|
|
/* Uname can fail only if you pass a bad pointer to it. */
|
|
uname(&uts);
|
|
|
|
return xstrndup(!*(uts.nodename) ? "?" : uts.nodename, sizeof(uts.nodename));
|
|
}
|