1/*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2010, 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 http://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 "setup.h" 24 25#ifdef HAVE_UNISTD_H 26# include <unistd.h> 27#endif 28 29#include "curl_gethostname.h" 30 31/* 32 * Curl_gethostname() is a wrapper around gethostname() which allows 33 * overriding the host name that the function would normally return. 34 * This capability is used by the test suite to verify exact matching 35 * of NTLM authentication, which exercises libcurl's MD4 and DES code 36 * as well as by the SMTP module when a hostname is not provided. 37 * 38 * For libcurl debug enabled builds host name overriding takes place 39 * when environment variable CURL_GETHOSTNAME is set, using the value 40 * held by the variable to override returned host name. 41 * 42 * Note: The function always returns the un-qualified hostname rather 43 * than being provider dependent. 44 * 45 * For libcurl shared library release builds the test suite preloads 46 * another shared library named libhostname using the LD_PRELOAD 47 * mechanism which intercepts, and might override, the gethostname() 48 * function call. In this case a given platform must support the 49 * LD_PRELOAD mechanism and additionally have environment variable 50 * CURL_GETHOSTNAME set in order to override the returned host name. 51 * 52 * For libcurl static library release builds no overriding takes place. 53 */ 54 55int Curl_gethostname(char *name, GETHOSTNAME_TYPE_ARG2 namelen) { 56 57#ifndef HAVE_GETHOSTNAME 58 59 /* Allow compilation and return failure when unavailable */ 60 (void) name; 61 (void) namelen; 62 return -1; 63 64#else 65 int err; 66 char* dot; 67 68#ifdef DEBUGBUILD 69 70 /* Override host name when environment variable CURL_GETHOSTNAME is set */ 71 const char *force_hostname = getenv("CURL_GETHOSTNAME"); 72 if(force_hostname) { 73 strncpy(name, force_hostname, namelen); 74 err = 0; 75 } 76 else { 77 name[0] = '\0'; 78 err = gethostname(name, namelen); 79 } 80 81#else /* DEBUGBUILD */ 82 83 /* The call to system's gethostname() might get intercepted by the 84 libhostname library when libcurl is built as a non-debug shared 85 library when running the test suite. */ 86 name[0] = '\0'; 87 err = gethostname(name, namelen); 88 89#endif 90 91 name[namelen - 1] = '\0'; 92 93 if(err) 94 return err; 95 96 /* Truncate domain, leave only machine name */ 97 dot = strchr(name, '.'); 98 if(dot) 99 *dot = '\0'; 100 101 return 0; 102#endif 103 104} 105