1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
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.se/docs/copyright.html.
13 *
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.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24
25 #include "curl_setup.h"
26
27 #include "curl_gethostname.h"
28
29 /*
30 * Curl_gethostname() is a wrapper around gethostname() which allows
31 * overriding the hostname that the function would normally return.
32 * This capability is used by the test suite to verify exact matching
33 * of NTLM authentication, which exercises libcurl's MD4 and DES code
34 * as well as by the SMTP module when a hostname is not provided.
35 *
36 * For libcurl debug enabled builds hostname overriding takes place
37 * when environment variable CURL_GETHOSTNAME is set, using the value
38 * held by the variable to override returned hostname.
39 *
40 * Note: The function always returns the un-qualified hostname rather
41 * than being provider dependent.
42 */
43
Curl_gethostname(char * const name,GETHOSTNAME_TYPE_ARG2 namelen)44 int Curl_gethostname(char * const name, GETHOSTNAME_TYPE_ARG2 namelen)
45 {
46 #ifndef HAVE_GETHOSTNAME
47
48 /* Allow compilation and return failure when unavailable */
49 (void) name;
50 (void) namelen;
51 return -1;
52
53 #else
54 int err;
55 char *dot;
56
57 #ifdef DEBUGBUILD
58
59 /* Override hostname when environment variable CURL_GETHOSTNAME is set */
60 const char *force_hostname = getenv("CURL_GETHOSTNAME");
61 if(force_hostname) {
62 if(strlen(force_hostname) < (size_t)namelen)
63 strcpy(name, force_hostname);
64 else
65 return 1; /* can't do it */
66 err = 0;
67 }
68 else {
69 name[0] = '\0';
70 err = gethostname(name, namelen);
71 }
72
73 #else /* DEBUGBUILD */
74
75 name[0] = '\0';
76 err = gethostname(name, namelen);
77
78 #endif
79
80 name[namelen - 1] = '\0';
81
82 if(err)
83 return err;
84
85 /* Truncate domain, leave only machine name */
86 dot = strchr(name, '.');
87 if(dot)
88 *dot = '\0';
89
90 return 0;
91 #endif
92
93 }
94
