curl/lib/curl_gethostname.c

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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
build: fix circular header inclusion with other packages This commit renames lib/setup.h to lib/curl_setup.h and renames lib/setup_once.h to lib/curl_setup_once.h. Removes the need and usage of a header inclusion guard foreign to libcurl. [1] Removes the need and presence of an alarming notice we carried in old setup_once.h [2] ---------------------------------------- 1 - lib/setup_once.h used __SETUP_ONCE_H macro as header inclusion guard up to commit ec691ca3 which changed this to HEADER_CURL_SETUP_ONCE_H, this single inclusion guard is enough to ensure that inclusion of lib/setup_once.h done from lib/setup.h is only done once. Additionally lib/setup.h has always used __SETUP_ONCE_H macro to protect inclusion of setup_once.h even after commit ec691ca3, this was to avoid a circular header inclusion triggered when building a c-ares enabled version with c-ares sources available which also has a setup_once.h header. Commit ec691ca3 exposes the real nature of __SETUP_ONCE_H usage in lib/setup.h, it is a header inclusion guard foreign to libcurl belonging to c-ares's setup_once.h The renaming this commit does, fixes the circular header inclusion, and as such removes the need and usage of a header inclusion guard foreign to libcurl. Macro __SETUP_ONCE_H no longer used in libcurl. 2 - Due to the circular interdependency of old lib/setup_once.h and the c-ares setup_once.h header, old file lib/setup_once.h has carried back from 2006 up to now days an alarming and prominent notice about the need of keeping libcurl's and c-ares's setup_once.h in sync. Given that this commit fixes the circular interdependency, the need and presence of mentioned notice is removed. All mentioned interdependencies come back from now old days when the c-ares project lived inside a curl subdirectory. This commit removes last traces of such fact.
2013-01-07 02:06:49 +08:00
#include "curl_setup.h"
#include "curl_gethostname.h"
/*
* Curl_gethostname() is a wrapper around gethostname() which allows
* overriding the host name that the function would normally return.
* This capability is used by the test suite to verify exact matching
* of NTLM authentication, which exercises libcurl's MD4 and DES code
* as well as by the SMTP module when a hostname is not provided.
*
* For libcurl debug enabled builds host name overriding takes place
* when environment variable CURL_GETHOSTNAME is set, using the value
* held by the variable to override returned host name.
*
* Note: The function always returns the un-qualified hostname rather
* than being provider dependent.
*
* For libcurl shared library release builds the test suite preloads
* another shared library named libhostname using the LD_PRELOAD
* mechanism which intercepts, and might override, the gethostname()
* function call. In this case a given platform must support the
* LD_PRELOAD mechanism and additionally have environment variable
* CURL_GETHOSTNAME set in order to override the returned host name.
*
* For libcurl static library release builds no overriding takes place.
*/
int Curl_gethostname(char *name, GETHOSTNAME_TYPE_ARG2 namelen)
{
#ifndef HAVE_GETHOSTNAME
/* Allow compilation and return failure when unavailable */
(void) name;
(void) namelen;
return -1;
#else
int err;
char *dot;
#ifdef DEBUGBUILD
/* Override host name when environment variable CURL_GETHOSTNAME is set */
const char *force_hostname = getenv("CURL_GETHOSTNAME");
if(force_hostname) {
strncpy(name, force_hostname, namelen);
err = 0;
}
else {
name[0] = '\0';
err = gethostname(name, namelen);
}
#else /* DEBUGBUILD */
/* The call to system's gethostname() might get intercepted by the
libhostname library when libcurl is built as a non-debug shared
library when running the test suite. */
name[0] = '\0';
err = gethostname(name, namelen);
#endif
name[namelen - 1] = '\0';
if(err)
return err;
/* Truncate domain, leave only machine name */
dot = strchr(name, '.');
if(dot)
*dot = '\0';
return 0;
#endif
}