1 /***************************************************************************
3 * Project ___| | | | _ \| |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
8 * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.haxx.se/docs/copyright.html.
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
21 ***************************************************************************/
23 #include "curl_setup.h"
25 #include "curl_gethostname.h"
28 * Curl_gethostname() is a wrapper around gethostname() which allows
29 * overriding the host name that the function would normally return.
30 * This capability is used by the test suite to verify exact matching
31 * of NTLM authentication, which exercises libcurl's MD4 and DES code
32 * as well as by the SMTP module when a hostname is not provided.
34 * For libcurl debug enabled builds host name overriding takes place
35 * when environment variable CURL_GETHOSTNAME is set, using the value
36 * held by the variable to override returned host name.
38 * Note: The function always returns the un-qualified hostname rather
39 * than being provider dependent.
41 * For libcurl shared library release builds the test suite preloads
42 * another shared library named libhostname using the LD_PRELOAD
43 * mechanism which intercepts, and might override, the gethostname()
44 * function call. In this case a given platform must support the
45 * LD_PRELOAD mechanism and additionally have environment variable
46 * CURL_GETHOSTNAME set in order to override the returned host name.
48 * For libcurl static library release builds no overriding takes place.
51 int Curl_gethostname(char *name, GETHOSTNAME_TYPE_ARG2 namelen) {
53 #ifndef HAVE_GETHOSTNAME
55 /* Allow compilation and return failure when unavailable */
66 /* Override host name when environment variable CURL_GETHOSTNAME is set */
67 const char *force_hostname = getenv("CURL_GETHOSTNAME");
69 strncpy(name, force_hostname, namelen);
74 err = gethostname(name, namelen);
77 #else /* DEBUGBUILD */
79 /* The call to system's gethostname() might get intercepted by the
80 libhostname library when libcurl is built as a non-debug shared
81 library when running the test suite. */
83 err = gethostname(name, namelen);
87 name[namelen - 1] = '\0';
92 /* Truncate domain, leave only machine name */
93 dot = strchr(name, '.');