curl/lib/getenv.c
Daniel Stenberg ae647a7941
tests: strict torture mode, warn on alloc after limit
In order to better track down cases where we don't exit cleanly and
directly on OOM errors, this mode warns if there is another memory
operation found *after* the torture limit was reached.

runtests sets this strict mode.

memdebug adds two new helper functions needed to make this work.

curl_dbg_overlook() lets the code mark a memory allocation as fine to
not notice and yet do another one after even if this one returns error.

curl_dbg_restart() marks the code as - at this point the code ignores
the OOM status and it is fine to do another memory call afterwards
without it being considered a problem.
2025-11-24 08:17:49 +01:00

81 lines
2.3 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 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.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.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "curl_setup.h"
#include <curl/curl.h>
#include "curl_memory.h"
#include "memdebug.h"
static char *GetEnv(const char *variable)
{
#if defined(CURL_WINDOWS_UWP) || \
defined(__ORBIS__) || defined(__PROSPERO__) /* PlayStation 4 and 5 */
(void)variable;
return NULL;
#elif defined(_WIN32)
/* This uses Windows API instead of C runtime getenv() to get the environment
variable since some changes are not always visible to the latter. #4774 */
char *buf = NULL;
char *tmp;
DWORD bufsize;
DWORD rc = 1;
const DWORD max = 32768; /* max env var size from MSCRT source */
for(;;) {
tmp = realloc(buf, rc);
if(!tmp) {
free(buf);
return NULL;
}
buf = tmp;
bufsize = rc;
/* it is possible for rc to be 0 if the variable was found but empty.
Since getenv does not make that distinction we ignore it as well. */
rc = GetEnvironmentVariableA(variable, buf, bufsize);
if(!rc || rc == bufsize || rc > max) {
free(buf);
return NULL;
}
/* if rc < bufsize then rc is bytes written not including null */
if(rc < bufsize)
return buf;
/* else rc is bytes needed, try again */
}
#else
char *env = getenv(variable);
curl_dbg_overlook(1);
return (env && env[0]) ? strdup(env) : NULL;
#endif
}
char *curl_getenv(const char *v)
{
return GetEnv(v);
}