link.c

Go to the documentation of this file.

/*
   +----------------------------------------------------------------------+
   | 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.               |
   +----------------------------------------------------------------------+
   | Author:                                                              |
   +----------------------------------------------------------------------+
 */
 
#include "php.h"
 
#if defined(HAVE_SYMLINK) || defined(PHP_WIN32)
 
#ifdef PHP_WIN32
#include <WinBase.h>
#endif
 
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifndef PHP_WIN32
#include <sys/stat.h>
#endif
#include <string.h>
#ifdef HAVE_PWD_H
#ifdef PHP_WIN32
#include "win32/pwd.h"
#else
#include <pwd.h>
#endif
#endif
#ifdef HAVE_GRP_H
# include <grp.h>
#endif
#include <errno.h>
#include <ctype.h>
 
#include "php_string.h"
 
#ifndef VOLUME_NAME_NT
#define VOLUME_NAME_NT 0x2
#endif
 
#ifndef VOLUME_NAME_DOS
#define VOLUME_NAME_DOS 0x0
#endif
 
/* {{{ Return the target of a symbolic link */
PHP_FUNCTION(readlink)
{
    char *link;
    size_t link_len;
    char buff[MAXPATHLEN];
    ssize_t ret;
 
    ZEND_PARSE_PARAMETERS_START(1, 1)
        Z_PARAM_PATH(link, link_len)
    ZEND_PARSE_PARAMETERS_END();
 
    if (php_check_open_basedir(link)) {
        RETURN_FALSE;
    }
 
    ret = php_sys_readlink(link, buff, MAXPATHLEN-1);
 
    if (ret == -1) {
#ifdef PHP_WIN32
        php_error_docref(NULL, E_WARNING, "readlink failed to read the symbolic link (%s), error %d", link, GetLastError());
#else
        php_error_docref(NULL, E_WARNING, "%s", strerror(errno));
#endif
        RETURN_FALSE;
    }
    /* Append NULL to the end of the string */
    buff[ret] = '\0';
 
    RETURN_STRINGL(buff, ret);
}
/* }}} */
 
/* {{{ Returns the st_dev field of the UNIX C stat structure describing the link */
PHP_FUNCTION(linkinfo)
{
    char *link;
    char *dirname;
    size_t link_len;
    zend_stat_t sb = {0};
    int ret;
 
    ZEND_PARSE_PARAMETERS_START(1, 1)
        Z_PARAM_PATH(link, link_len)
    ZEND_PARSE_PARAMETERS_END();
 
    // TODO Check for empty string
    dirname = estrndup(link, link_len);
    zend_dirname(dirname, link_len);
 
    if (php_check_open_basedir(dirname)) {
        efree(dirname);
        RETURN_FALSE;
    }
 
    ret = VCWD_LSTAT(link, &sb);
    if (ret == -1) {
        php_error_docref(NULL, E_WARNING, "%s", strerror(errno));
        efree(dirname);
        RETURN_LONG(Z_L(-1));
    }
 
    efree(dirname);
    RETURN_LONG((zend_long) sb.st_dev);
}
/* }}} */
 
/* {{{ Create a symbolic link */
PHP_FUNCTION(symlink)
{
    char *topath, *frompath;
    size_t topath_len, frompath_len;
    int ret;
    char source_p[MAXPATHLEN];
    char dest_p[MAXPATHLEN];
    char dirname[MAXPATHLEN];
    size_t len;
 
    ZEND_PARSE_PARAMETERS_START(2, 2)
        Z_PARAM_PATH(topath, topath_len)
        Z_PARAM_PATH(frompath, frompath_len)
    ZEND_PARSE_PARAMETERS_END();
 
    if (!expand_filepath(frompath, source_p)) {
        php_error_docref(NULL, E_WARNING, "No such file or directory");
        RETURN_FALSE;
    }
 
    memcpy(dirname, source_p, sizeof(source_p));
    len = zend_dirname(dirname, strlen(dirname));
 
    if (!expand_filepath_ex(topath, dest_p, dirname, len)) {
        php_error_docref(NULL, E_WARNING, "No such file or directory");
        RETURN_FALSE;
    }
 
    if (php_stream_locate_url_wrapper(source_p, NULL, STREAM_LOCATE_WRAPPERS_ONLY) ||
        php_stream_locate_url_wrapper(dest_p, NULL, STREAM_LOCATE_WRAPPERS_ONLY) )
    {
        php_error_docref(NULL, E_WARNING, "Unable to symlink to a URL");
        RETURN_FALSE;
    }
 
    if (php_check_open_basedir(dest_p)) {
        RETURN_FALSE;
    }
 
    if (php_check_open_basedir(source_p)) {
        RETURN_FALSE;
    }
 
    /* For the source, an expanded path must be used (in ZTS an other thread could have changed the CWD).
     * For the target the exact string given by the user must be used, relative or not, existing or not.
     * The target is relative to the link itself, not to the CWD. */
    ret = php_sys_symlink(topath, source_p);
 
    if (ret == -1) {
        php_error_docref(NULL, E_WARNING, "%s", strerror(errno));
        RETURN_FALSE;
    }
 
    RETURN_TRUE;
}
/* }}} */
 
/* {{{ Create a hard link */
PHP_FUNCTION(link)
{
    char *topath, *frompath;
    size_t topath_len, frompath_len;
    int ret;
    char source_p[MAXPATHLEN];
    char dest_p[MAXPATHLEN];
 
    ZEND_PARSE_PARAMETERS_START(2, 2)
        Z_PARAM_PATH(topath, topath_len)
        Z_PARAM_PATH(frompath, frompath_len)
    ZEND_PARSE_PARAMETERS_END();
 
    if (!expand_filepath(frompath, source_p) || !expand_filepath(topath, dest_p)) {
        php_error_docref(NULL, E_WARNING, "No such file or directory");
        RETURN_FALSE;
    }
 
    if (php_stream_locate_url_wrapper(source_p, NULL, STREAM_LOCATE_WRAPPERS_ONLY) ||
        php_stream_locate_url_wrapper(dest_p, NULL, STREAM_LOCATE_WRAPPERS_ONLY) )
    {
        php_error_docref(NULL, E_WARNING, "Unable to link to a URL");
        RETURN_FALSE;
    }
 
    if (php_check_open_basedir(dest_p)) {
        RETURN_FALSE;
    }
 
    if (php_check_open_basedir(source_p)) {
        RETURN_FALSE;
    }
 
#ifndef ZTS
    ret = php_sys_link(topath, frompath);
#else
    ret = php_sys_link(dest_p, source_p);
#endif
    if (ret == -1) {
        php_error_docref(NULL, E_WARNING, "%s", strerror(errno));
        RETURN_FALSE;
    }
 
    RETURN_TRUE;
}
/* }}} */
 
#endif