1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel (at) 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
