1 | /*************************************************************************** |
2 | * _ _ ____ _ |
3 | * Project ___| | | | _ \| | |
4 | * / __| | | | |_) | | |
5 | * | (__| |_| | _ <| |___ |
6 | * \___|\___/|_| \_\_____| |
7 | * |
8 | * Copyright (C) 1998 - 2016, 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.haxx.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 | ***************************************************************************/ |
22 | |
23 | #include "curl_setup.h" |
24 | |
25 | #include "curl_gethostname.h" |
26 | |
27 | /* |
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. |
33 | * |
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. |
37 | * |
38 | * Note: The function always returns the un-qualified hostname rather |
39 | * than being provider dependent. |
40 | * |
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. |
47 | * |
48 | * For libcurl static library release builds no overriding takes place. |
49 | */ |
50 | |
51 | int Curl_gethostname(char *name, GETHOSTNAME_TYPE_ARG2 namelen) |
52 | { |
53 | #ifndef HAVE_GETHOSTNAME |
54 | |
55 | /* Allow compilation and return failure when unavailable */ |
56 | (void) name; |
57 | (void) namelen; |
58 | return -1; |
59 | |
60 | #else |
61 | int err; |
62 | char *dot; |
63 | |
64 | #ifdef DEBUGBUILD |
65 | |
66 | /* Override host name when environment variable CURL_GETHOSTNAME is set */ |
67 | const char *force_hostname = getenv("CURL_GETHOSTNAME" ); |
68 | if(force_hostname) { |
69 | strncpy(name, force_hostname, namelen); |
70 | err = 0; |
71 | } |
72 | else { |
73 | name[0] = '\0'; |
74 | err = gethostname(name, namelen); |
75 | } |
76 | |
77 | #else /* DEBUGBUILD */ |
78 | |
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. */ |
82 | name[0] = '\0'; |
83 | err = gethostname(name, namelen); |
84 | |
85 | #endif |
86 | |
87 | name[namelen - 1] = '\0'; |
88 | |
89 | if(err) |
90 | return err; |
91 | |
92 | /* Truncate domain, leave only machine name */ |
93 | dot = strchr(name, '.'); |
94 | if(dot) |
95 | *dot = '\0'; |
96 | |
97 | return 0; |
98 | #endif |
99 | |
100 | } |
101 | |