php-src/main/fopen_wrappers.c
2024-06-24 19:52:55 +02:00

842 lines
23 KiB
C

/*
+----------------------------------------------------------------------+
| Copyright (c) The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| https://www.php.net/license/3_01.txt |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Rasmus Lerdorf <rasmus@lerdorf.on.ca> |
| Jim Winstead <jimw@php.net> |
+----------------------------------------------------------------------+
*/
/* {{{ includes */
#include "php.h"
#include "php_globals.h"
#include "SAPI.h"
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#ifdef PHP_WIN32
#define O_RDONLY _O_RDONLY
#include "win32/param.h"
#else
#include <sys/param.h>
#endif
#include "ext/standard/head.h"
#include "ext/standard/php_standard.h"
#include "zend_compile.h"
#include "php_network.h"
#if HAVE_PWD_H
#include <pwd.h>
#endif
#include <sys/types.h>
#if HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef PHP_WIN32
#include <winsock2.h>
#else
#include <netinet/in.h>
#include <netdb.h>
#if HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#endif
#if defined(PHP_WIN32) || defined(__riscos__)
#undef AF_UNIX
#endif
#if defined(AF_UNIX)
#include <sys/un.h>
#endif
/* }}} */
/* {{{ OnUpdateBaseDir
Allows any change to open_basedir setting in during Startup and Shutdown events,
or a tightening during activation/runtime/deactivation */
PHPAPI ZEND_INI_MH(OnUpdateBaseDir)
{
char **p = (char **) ZEND_INI_GET_ADDR();
char *pathbuf, *ptr, *end;
if (stage == PHP_INI_STAGE_STARTUP || stage == PHP_INI_STAGE_SHUTDOWN || stage == PHP_INI_STAGE_ACTIVATE || stage == PHP_INI_STAGE_DEACTIVATE) {
/* We're in a PHP_INI_SYSTEM context, no restrictions */
*p = new_value ? ZSTR_VAL(new_value) : NULL;
return SUCCESS;
}
/* Otherwise we're in runtime */
if (!*p || !**p) {
/* open_basedir not set yet, go ahead and give it a value */
*p = ZSTR_VAL(new_value);
return SUCCESS;
}
/* Shortcut: When we have a open_basedir and someone tries to unset, we know it'll fail */
if (!new_value || !*ZSTR_VAL(new_value)) {
return FAILURE;
}
/* Is the proposed open_basedir at least as restrictive as the current setting? */
ptr = pathbuf = estrdup(ZSTR_VAL(new_value));
while (ptr && *ptr) {
end = strchr(ptr, DEFAULT_DIR_SEPARATOR);
if (end != NULL) {
*end = '\0';
end++;
}
if (ptr[0] == '.' && ptr[1] == '.' && (ptr[2] == '\0' || IS_SLASH(ptr[2]))) {
/* Don't allow paths with a leading .. path component to be set at runtime */
efree(pathbuf);
return FAILURE;
}
if (php_check_open_basedir_ex(ptr, 0) != 0) {
/* At least one portion of this open_basedir is less restrictive than the prior one, FAIL */
efree(pathbuf);
return FAILURE;
}
ptr = end;
}
efree(pathbuf);
/* Everything checks out, set it */
*p = ZSTR_VAL(new_value);
return SUCCESS;
}
/* }}} */
/* {{{ php_check_specific_open_basedir
When open_basedir is not NULL, check if the given filename is located in
open_basedir. Returns -1 if error or not in the open_basedir, else 0.
When open_basedir is NULL, always return 0.
*/
PHPAPI int php_check_specific_open_basedir(const char *basedir, const char *path)
{
char resolved_name[MAXPATHLEN + 1];
char resolved_basedir[MAXPATHLEN + 1];
char local_open_basedir[MAXPATHLEN];
char path_tmp[MAXPATHLEN + 1];
char *path_file;
size_t resolved_basedir_len;
size_t resolved_name_len;
size_t path_len;
int nesting_level = 0;
/* Special case basedir==".": Use script-directory */
if (strcmp(basedir, ".") || !VCWD_GETCWD(local_open_basedir, MAXPATHLEN)) {
/* Else use the unmodified path */
strlcpy(local_open_basedir, basedir, sizeof(local_open_basedir));
}
path_len = strlen(path);
if (path_len > (MAXPATHLEN - 1)) {
/* empty and too long paths are invalid */
return -1;
}
/* normalize and expand path */
if (expand_filepath(path, resolved_name) == NULL) {
return -1;
}
path_len = strlen(resolved_name);
memcpy(path_tmp, resolved_name, path_len + 1); /* safe */
while (VCWD_REALPATH(path_tmp, resolved_name) == NULL) {
#if defined(PHP_WIN32) || defined(HAVE_SYMLINK)
if (nesting_level == 0) {
ssize_t ret;
char buf[MAXPATHLEN];
ret = php_sys_readlink(path_tmp, buf, MAXPATHLEN - 1);
if (ret == -1) {
/* not a broken symlink, move along.. */
} else {
/* put the real path into the path buffer */
memcpy(path_tmp, buf, ret);
path_tmp[ret] = '\0';
}
}
#endif
#ifdef PHP_WIN32
path_file = strrchr(path_tmp, DEFAULT_SLASH);
if (!path_file) {
path_file = strrchr(path_tmp, '/');
}
#else
path_file = strrchr(path_tmp, DEFAULT_SLASH);
#endif
if (!path_file) {
/* none of the path components exist. definitely not in open_basedir.. */
return -1;
} else {
path_len = path_file - path_tmp + 1;
#ifdef PHP_WIN32
if (path_len > 1 && path_tmp[path_len - 2] == ':') {
if (path_len != 3) {
return -1;
}
/* this is c:\ */
path_tmp[path_len] = '\0';
} else {
path_tmp[path_len - 1] = '\0';
}
#else
path_tmp[path_len - 1] = '\0';
#endif
}
if (*path_tmp == '\0') {
/* Do not pass an empty string to realpath(), as this will resolve to CWD. */
break;
}
nesting_level++;
}
/* Resolve open_basedir to resolved_basedir */
if (expand_filepath(local_open_basedir, resolved_basedir) != NULL) {
size_t basedir_len = strlen(basedir);
/* Handler for basedirs that end with a / */
resolved_basedir_len = strlen(resolved_basedir);
#ifdef PHP_WIN32
if (basedir[basedir_len - 1] == PHP_DIR_SEPARATOR || basedir[basedir_len - 1] == '/') {
#else
if (basedir[basedir_len - 1] == PHP_DIR_SEPARATOR) {
#endif
if (resolved_basedir[resolved_basedir_len - 1] != PHP_DIR_SEPARATOR) {
resolved_basedir[resolved_basedir_len] = PHP_DIR_SEPARATOR;
resolved_basedir[++resolved_basedir_len] = '\0';
}
} else {
resolved_basedir[resolved_basedir_len++] = PHP_DIR_SEPARATOR;
resolved_basedir[resolved_basedir_len] = '\0';
}
resolved_name_len = strlen(resolved_name);
if (path_tmp[path_len - 1] == PHP_DIR_SEPARATOR) {
if (resolved_name[resolved_name_len - 1] != PHP_DIR_SEPARATOR) {
resolved_name[resolved_name_len] = PHP_DIR_SEPARATOR;
resolved_name[++resolved_name_len] = '\0';
}
}
/* Check the path */
#ifdef PHP_WIN32
if (strncasecmp(resolved_basedir, resolved_name, resolved_basedir_len) == 0) {
#else
if (strncmp(resolved_basedir, resolved_name, resolved_basedir_len) == 0) {
#endif
if (resolved_name_len > resolved_basedir_len &&
resolved_name[resolved_basedir_len - 1] != PHP_DIR_SEPARATOR) {
return -1;
} else {
/* File is in the right directory */
return 0;
}
} else {
/* /openbasedir/ and /openbasedir are the same directory */
if (resolved_basedir_len == (resolved_name_len + 1) && resolved_basedir[resolved_basedir_len - 1] == PHP_DIR_SEPARATOR) {
#ifdef PHP_WIN32
if (strncasecmp(resolved_basedir, resolved_name, resolved_name_len) == 0) {
#else
if (strncmp(resolved_basedir, resolved_name, resolved_name_len) == 0) {
#endif
return 0;
}
}
return -1;
}
} else {
/* Unable to resolve the real path, return -1 */
return -1;
}
}
/* }}} */
PHPAPI int php_check_open_basedir(const char *path)
{
return php_check_open_basedir_ex(path, 1);
}
/* {{{ php_check_open_basedir */
PHPAPI int php_check_open_basedir_ex(const char *path, int warn)
{
/* Only check when open_basedir is available */
if (PG(open_basedir) && *PG(open_basedir)) {
char *pathbuf;
char *ptr;
char *end;
/* Check if the path is too long so we can give a more useful error
* message. */
if (strlen(path) > (MAXPATHLEN - 1)) {
php_error_docref(NULL, E_WARNING, "File name is longer than the maximum allowed path length on this platform (%d): %s", MAXPATHLEN, path);
errno = EINVAL;
return -1;
}
pathbuf = estrdup(PG(open_basedir));
ptr = pathbuf;
while (ptr && *ptr) {
end = strchr(ptr, DEFAULT_DIR_SEPARATOR);
if (end != NULL) {
*end = '\0';
end++;
}
if (php_check_specific_open_basedir(ptr, path) == 0) {
efree(pathbuf);
return 0;
}
ptr = end;
}
if (warn) {
php_error_docref(NULL, E_WARNING, "open_basedir restriction in effect. File(%s) is not within the allowed path(s): (%s)", path, PG(open_basedir));
}
efree(pathbuf);
errno = EPERM; /* we deny permission to open it */
return -1;
}
/* Nothing to check... */
return 0;
}
/* }}} */
/* {{{ php_fopen_and_set_opened_path */
static FILE *php_fopen_and_set_opened_path(const char *path, const char *mode, zend_string **opened_path)
{
FILE *fp;
if (php_check_open_basedir((char *)path)) {
return NULL;
}
fp = VCWD_FOPEN(path, mode);
if (fp && opened_path) {
//TODO :avoid reallocation
char *tmp = expand_filepath_with_mode(path, NULL, NULL, 0, CWD_EXPAND);
if (tmp) {
*opened_path = zend_string_init(tmp, strlen(tmp), 0);
efree(tmp);
}
}
return fp;
}
/* }}} */
/* {{{ php_fopen_primary_script */
PHPAPI int php_fopen_primary_script(zend_file_handle *file_handle)
{
char *path_info;
zend_string *filename = NULL;
zend_string *resolved_path = NULL;
size_t length;
bool orig_display_errors;
memset(file_handle, 0, sizeof(zend_file_handle));
path_info = SG(request_info).request_uri;
#if HAVE_PWD_H
if (PG(user_dir) && *PG(user_dir) && path_info && '/' == path_info[0] && '~' == path_info[1]) {
char *s = strchr(path_info + 2, '/');
if (s) { /* if there is no path name after the file, do not bother */
char user[32]; /* to try open the directory */
length = s - (path_info + 2);
if (length > sizeof(user) - 1) {
length = sizeof(user) - 1;
}
memcpy(user, path_info + 2, length);
user[length] = '\0';
struct passwd *pw;
#if defined(ZTS) && defined(HAVE_GETPWNAM_R) && defined(_SC_GETPW_R_SIZE_MAX)
struct passwd pwstruc;
long pwbuflen = sysconf(_SC_GETPW_R_SIZE_MAX);
char *pwbuf;
int err;
if (pwbuflen < 1) {
pwbuflen = 1024;
}
# if ZEND_DEBUG
/* Test retry logic */
pwbuflen = 1;
# endif
pwbuf = emalloc(pwbuflen);
try_again:
err = getpwnam_r(user, &pwstruc, pwbuf, pwbuflen, &pw);
if (err) {
if (err == ERANGE) {
pwbuflen *= 2;
pwbuf = erealloc(pwbuf, pwbuflen);
goto try_again;
}
efree(pwbuf);
return FAILURE;
}
#else
pw = getpwnam(user);
#endif
if (pw && pw->pw_dir) {
filename = zend_strpprintf(0, "%s%c%s%c%s", pw->pw_dir, PHP_DIR_SEPARATOR, PG(user_dir), PHP_DIR_SEPARATOR, s + 1); /* Safe */
} else if (SG(request_info).path_translated) {
filename = zend_string_init(SG(request_info).path_translated,
strlen(SG(request_info).path_translated), 0);
}
#if defined(ZTS) && defined(HAVE_GETPWNAM_R) && defined(_SC_GETPW_R_SIZE_MAX)
efree(pwbuf);
#endif
}
} else
#endif
if (PG(doc_root) && path_info && (length = strlen(PG(doc_root))) &&
IS_ABSOLUTE_PATH(PG(doc_root), length)) {
size_t path_len = strlen(path_info);
filename = zend_string_alloc(length + path_len + 2, 0);
memcpy(ZSTR_VAL(filename), PG(doc_root), length);
if (!IS_SLASH(ZSTR_VAL(filename)[length - 1])) { /* length is never 0 */
ZSTR_VAL(filename)[length++] = PHP_DIR_SEPARATOR;
}
if (IS_SLASH(path_info[0])) {
length--;
}
strncpy(ZSTR_VAL(filename) + length, path_info, path_len + 1);
ZSTR_LEN(filename) = length + path_len;
} else if (SG(request_info).path_translated) {
filename = zend_string_init(SG(request_info).path_translated,
strlen(SG(request_info).path_translated), 0);
}
if (filename) {
resolved_path = zend_resolve_path(filename);
}
if (!resolved_path) {
if (filename) {
zend_string_release(filename);
}
/* we have to free SG(request_info).path_translated here because
* php_destroy_request_info assumes that it will get
* freed when the include_names hash is emptied, but
* we're not adding it in this case */
if (SG(request_info).path_translated) {
efree(SG(request_info).path_translated);
SG(request_info).path_translated = NULL;
}
return FAILURE;
}
zend_string_release_ex(resolved_path, 0);
orig_display_errors = PG(display_errors);
PG(display_errors) = 0;
zend_stream_init_filename_ex(file_handle, filename);
file_handle->primary_script = 1;
if (filename) {
zend_string_delref(filename);
}
if (zend_stream_open(file_handle) == FAILURE) {
PG(display_errors) = orig_display_errors;
if (SG(request_info).path_translated) {
efree(SG(request_info).path_translated);
SG(request_info).path_translated = NULL;
}
return FAILURE;
}
PG(display_errors) = orig_display_errors;
return SUCCESS;
}
/* }}} */
static zend_string *tsrm_realpath_str(const char *path) {
char *realpath = tsrm_realpath(path, NULL);
if (!realpath) {
return NULL;
}
zend_string *realpath_str = zend_string_init(realpath, strlen(realpath), 0);
efree(realpath);
return realpath_str;
}
/* {{{ php_resolve_path
* Returns the realpath for given filename according to include path
*/
PHPAPI zend_string *php_resolve_path(const char *filename, size_t filename_length, const char *path)
{
zend_string *resolved_path;
char trypath[MAXPATHLEN];
const char *ptr, *end, *p;
const char *actual_path;
php_stream_wrapper *wrapper;
zend_string *exec_filename;
if (!filename || CHECK_NULL_PATH(filename, filename_length)) {
return NULL;
}
/* Don't resolve paths which contain protocol (except of file://) */
for (p = filename; isalnum((int)*p) || *p == '+' || *p == '-' || *p == '.'; p++);
if ((*p == ':') && (p - filename > 1) && (p[1] == '/') && (p[2] == '/')) {
wrapper = php_stream_locate_url_wrapper(filename, &actual_path, STREAM_OPEN_FOR_INCLUDE);
if (wrapper == &php_plain_files_wrapper) {
if ((resolved_path = tsrm_realpath_str(actual_path))) {
return resolved_path;
}
}
return NULL;
}
if ((*filename == '.' &&
(IS_SLASH(filename[1]) ||
((filename[1] == '.') && IS_SLASH(filename[2])))) ||
IS_ABSOLUTE_PATH(filename, filename_length) ||
#ifdef PHP_WIN32
/* This should count as an absolute local path as well, however
IS_ABSOLUTE_PATH doesn't care about this path form till now. It
might be a big thing to extend, thus just a local handling for
now. */
filename_length >=2 && IS_SLASH(filename[0]) && !IS_SLASH(filename[1]) ||
#endif
!path ||
!*path) {
return tsrm_realpath_str(filename);
}
ptr = path;
while (ptr && *ptr) {
/* Check for stream wrapper */
int is_stream_wrapper = 0;
for (p = ptr; isalnum((int)*p) || *p == '+' || *p == '-' || *p == '.'; p++);
if ((*p == ':') && (p - ptr > 1) && (p[1] == '/') && (p[2] == '/')) {
/* .:// or ..:// is not a stream wrapper */
if (p[-1] != '.' || p[-2] != '.' || p - 2 != ptr) {
p += 3;
is_stream_wrapper = 1;
}
}
end = strchr(p, DEFAULT_DIR_SEPARATOR);
if (end) {
if (filename_length > (MAXPATHLEN - 2) || (end-ptr) > MAXPATHLEN || (end-ptr) + 1 + filename_length + 1 >= MAXPATHLEN) {
ptr = end + 1;
continue;
}
memcpy(trypath, ptr, end-ptr);
trypath[end-ptr] = '/';
memcpy(trypath+(end-ptr)+1, filename, filename_length+1);
ptr = end+1;
} else {
size_t len = strlen(ptr);
if (filename_length > (MAXPATHLEN - 2) || len > MAXPATHLEN || len + 1 + filename_length + 1 >= MAXPATHLEN) {
break;
}
memcpy(trypath, ptr, len);
trypath[len] = '/';
memcpy(trypath+len+1, filename, filename_length+1);
ptr = NULL;
}
actual_path = trypath;
if (is_stream_wrapper) {
wrapper = php_stream_locate_url_wrapper(trypath, &actual_path, STREAM_OPEN_FOR_INCLUDE);
if (!wrapper) {
continue;
} else if (wrapper != &php_plain_files_wrapper) {
if (wrapper->wops->url_stat) {
php_stream_statbuf ssb;
if (SUCCESS == wrapper->wops->url_stat(wrapper, trypath, PHP_STREAM_URL_STAT_QUIET, &ssb, NULL)) {
return zend_string_init(trypath, strlen(trypath), 0);
}
if (EG(exception)) {
return NULL;
}
}
continue;
}
}
if ((resolved_path = tsrm_realpath_str(actual_path))) {
return resolved_path;
}
} /* end provided path */
/* check in calling scripts' current working directory as a fall back case
*/
if (zend_is_executing() &&
(exec_filename = zend_get_executed_filename_ex()) != NULL) {
const char *exec_fname = ZSTR_VAL(exec_filename);
size_t exec_fname_length = ZSTR_LEN(exec_filename);
while ((--exec_fname_length < SIZE_MAX) && !IS_SLASH(exec_fname[exec_fname_length]));
if (exec_fname_length > 0 &&
filename_length < (MAXPATHLEN - 2) &&
exec_fname_length + 1 + filename_length + 1 < MAXPATHLEN) {
memcpy(trypath, exec_fname, exec_fname_length + 1);
memcpy(trypath+exec_fname_length + 1, filename, filename_length+1);
actual_path = trypath;
/* Check for stream wrapper */
for (p = trypath; isalnum((int)*p) || *p == '+' || *p == '-' || *p == '.'; p++);
if ((*p == ':') && (p - trypath > 1) && (p[1] == '/') && (p[2] == '/')) {
wrapper = php_stream_locate_url_wrapper(trypath, &actual_path, STREAM_OPEN_FOR_INCLUDE);
if (!wrapper) {
return NULL;
} else if (wrapper != &php_plain_files_wrapper) {
if (wrapper->wops->url_stat) {
php_stream_statbuf ssb;
if (SUCCESS == wrapper->wops->url_stat(wrapper, trypath, PHP_STREAM_URL_STAT_QUIET, &ssb, NULL)) {
return zend_string_init(trypath, strlen(trypath), 0);
}
if (EG(exception)) {
return NULL;
}
}
return NULL;
}
}
return tsrm_realpath_str(actual_path);
}
}
return NULL;
}
/* }}} */
/* {{{ php_fopen_with_path
* Tries to open a file with a PATH-style list of directories.
* If the filename starts with "." or "/", the path is ignored.
*/
PHPAPI FILE *php_fopen_with_path(const char *filename, const char *mode, const char *path, zend_string **opened_path)
{
char *pathbuf, *ptr, *end;
char trypath[MAXPATHLEN];
FILE *fp;
size_t filename_length;
zend_string *exec_filename;
if (opened_path) {
*opened_path = NULL;
}
if (!filename) {
return NULL;
}
filename_length = strlen(filename);
#ifndef PHP_WIN32
(void) filename_length;
#endif
/* Relative path open */
if ((*filename == '.')
/* Absolute path open */
|| IS_ABSOLUTE_PATH(filename, filename_length)
|| (!path || !*path)
) {
return php_fopen_and_set_opened_path(filename, mode, opened_path);
}
/* check in provided path */
/* append the calling scripts' current working directory
* as a fall back case
*/
if (zend_is_executing() &&
(exec_filename = zend_get_executed_filename_ex()) != NULL) {
const char *exec_fname = ZSTR_VAL(exec_filename);
size_t exec_fname_length = ZSTR_LEN(exec_filename);
while ((--exec_fname_length < SIZE_MAX) && !IS_SLASH(exec_fname[exec_fname_length]));
if ((exec_fname && exec_fname[0] == '[') || exec_fname_length <= 0) {
/* [no active file] or no path */
pathbuf = estrdup(path);
} else {
size_t path_length = strlen(path);
pathbuf = (char *) emalloc(exec_fname_length + path_length + 1 + 1);
memcpy(pathbuf, path, path_length);
pathbuf[path_length] = DEFAULT_DIR_SEPARATOR;
memcpy(pathbuf + path_length + 1, exec_fname, exec_fname_length);
pathbuf[path_length + exec_fname_length + 1] = '\0';
}
} else {
pathbuf = estrdup(path);
}
ptr = pathbuf;
while (ptr && *ptr) {
end = strchr(ptr, DEFAULT_DIR_SEPARATOR);
if (end != NULL) {
*end = '\0';
end++;
}
if (snprintf(trypath, MAXPATHLEN, "%s/%s", ptr, filename) >= MAXPATHLEN) {
php_error_docref(NULL, E_NOTICE, "%s/%s path was truncated to %d", ptr, filename, MAXPATHLEN);
}
fp = php_fopen_and_set_opened_path(trypath, mode, opened_path);
if (fp) {
efree(pathbuf);
return fp;
}
ptr = end;
} /* end provided path */
efree(pathbuf);
return NULL;
}
/* }}} */
/* {{{ php_strip_url_passwd */
PHPAPI char *php_strip_url_passwd(char *url)
{
char *p, *url_start;
if (url == NULL) {
return "";
}
p = url;
while (*p) {
if (*p == ':' && *(p + 1) == '/' && *(p + 2) == '/') {
/* found protocol */
url_start = p = p + 3;
while (*p) {
if (*p == '@') {
int i;
for (i = 0; i < 3 && url_start < p; i++, url_start++) {
*url_start = '.';
}
for (; *p; p++) {
*url_start++ = *p;
}
*url_start=0;
break;
}
p++;
}
return url;
}
p++;
}
return url;
}
/* }}} */
/* {{{ expand_filepath */
PHPAPI char *expand_filepath(const char *filepath, char *real_path)
{
return expand_filepath_ex(filepath, real_path, NULL, 0);
}
/* }}} */
/* {{{ expand_filepath_ex */
PHPAPI char *expand_filepath_ex(const char *filepath, char *real_path, const char *relative_to, size_t relative_to_len)
{
return expand_filepath_with_mode(filepath, real_path, relative_to, relative_to_len, CWD_FILEPATH);
}
/* }}} */
/* {{{ expand_filepath_use_realpath */
PHPAPI char *expand_filepath_with_mode(const char *filepath, char *real_path, const char *relative_to, size_t relative_to_len, int realpath_mode)
{
cwd_state new_state;
char cwd[MAXPATHLEN];
size_t copy_len;
size_t path_len;
if (!filepath[0]) {
return NULL;
}
path_len = strlen(filepath);
if (IS_ABSOLUTE_PATH(filepath, path_len)) {
cwd[0] = '\0';
} else {
const char *iam = SG(request_info).path_translated;
const char *result;
if (relative_to) {
if (relative_to_len > MAXPATHLEN-1U) {
return NULL;
}
result = relative_to;
memcpy(cwd, relative_to, relative_to_len+1U);
} else {
result = VCWD_GETCWD(cwd, MAXPATHLEN);
}
if (!result && (iam != filepath)) {
int fdtest = -1;
fdtest = VCWD_OPEN(filepath, O_RDONLY);
if (fdtest != -1) {
/* return a relative file path if for any reason
* we cannot cannot getcwd() and the requested,
* relatively referenced file is accessible */
copy_len = path_len > MAXPATHLEN - 1 ? MAXPATHLEN - 1 : path_len;
if (real_path) {
memcpy(real_path, filepath, copy_len);
real_path[copy_len] = '\0';
} else {
real_path = estrndup(filepath, copy_len);
}
close(fdtest);
return real_path;
} else {
cwd[0] = '\0';
}
} else if (!result) {
cwd[0] = '\0';
}
}
new_state.cwd = estrdup(cwd);
new_state.cwd_length = strlen(cwd);
if (virtual_file_ex(&new_state, filepath, NULL, realpath_mode)) {
efree(new_state.cwd);
return NULL;
}
if (real_path) {
copy_len = new_state.cwd_length > MAXPATHLEN - 1 ? MAXPATHLEN - 1 : new_state.cwd_length;
memcpy(real_path, new_state.cwd, copy_len);
real_path[copy_len] = '\0';
} else {
real_path = estrndup(new_state.cwd, new_state.cwd_length);
}
efree(new_state.cwd);
return real_path;
}
/* }}} */