php-src/ext/session/mod_files.c
2015-02-03 14:02:58 +09:00

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/*
+----------------------------------------------------------------------+
| PHP Version 5 |
+----------------------------------------------------------------------+
| Copyright (c) 1997-2015 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: |
| http://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: Sascha Schumann <sascha@schumann.cx> |
+----------------------------------------------------------------------+
*/
/* $Id$ */
#include "php.h"
#include <sys/stat.h>
#include <sys/types.h>
#if HAVE_SYS_FILE_H
#include <sys/file.h>
#endif
#if HAVE_DIRENT_H
#include <dirent.h>
#endif
#ifdef PHP_WIN32
#include "win32/readdir.h"
#endif
#include <time.h>
#include <fcntl.h>
#include <errno.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "php_session.h"
#include "mod_files.h"
#include "ext/standard/flock_compat.h"
#include "php_open_temporary_file.h"
#define FILE_PREFIX "sess_"
#ifdef PHP_WIN32
# ifndef O_NOFOLLOW
# define O_NOFOLLOW 0
# endif
#endif
typedef struct {
int fd;
char *lastkey;
char *basedir;
size_t basedir_len;
size_t dirdepth;
size_t st_size;
int filemode;
} ps_files;
ps_module ps_mod_files = {
PS_MOD_SID(files)
};
static char *ps_files_path_create(char *buf, size_t buflen, ps_files *data, const char *key)
{
size_t key_len;
const char *p;
int i;
int n;
key_len = strlen(key);
if (key_len <= data->dirdepth ||
buflen < (strlen(data->basedir) + 2 * data->dirdepth + key_len + 5 + sizeof(FILE_PREFIX))) {
return NULL;
}
p = key;
memcpy(buf, data->basedir, data->basedir_len);
n = data->basedir_len;
buf[n++] = PHP_DIR_SEPARATOR;
for (i = 0; i < (int)data->dirdepth; i++) {
buf[n++] = *p++;
buf[n++] = PHP_DIR_SEPARATOR;
}
memcpy(buf + n, FILE_PREFIX, sizeof(FILE_PREFIX) - 1);
n += sizeof(FILE_PREFIX) - 1;
memcpy(buf + n, key, key_len);
n += key_len;
buf[n] = '\0';
return buf;
}
#ifndef O_BINARY
# define O_BINARY 0
#endif
static void ps_files_close(ps_files *data)
{
if (data->fd != -1) {
#ifdef PHP_WIN32
/* On Win32 locked files that are closed without being explicitly unlocked
will be unlocked only when "system resources become available". */
flock(data->fd, LOCK_UN);
#endif
close(data->fd);
data->fd = -1;
}
}
static void ps_files_open(ps_files *data, const char *key TSRMLS_DC)
{
char buf[MAXPATHLEN];
struct stat sbuf;
int ret;
if (data->fd < 0 || !data->lastkey || strcmp(key, data->lastkey)) {
if (data->lastkey) {
efree(data->lastkey);
data->lastkey = NULL;
}
ps_files_close(data);
if (php_session_valid_key(key) == FAILURE) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "The session id is too long or contains illegal characters, valid characters are a-z, A-Z, 0-9 and '-,'");
return;
}
if (!ps_files_path_create(buf, sizeof(buf), data, key)) {
return;
}
data->lastkey = estrdup(key);
/* O_NOFOLLOW to prevent us from following evil symlinks */
#ifdef O_NOFOLLOW
data->fd = VCWD_OPEN_MODE(buf, O_CREAT | O_RDWR | O_BINARY | O_NOFOLLOW, data->filemode);
#else
/* Check to make sure that the opened file is not outside of allowable dirs.
This is not 100% safe but it's hard to do something better without O_NOFOLLOW */
if(PG(open_basedir) && lstat(buf, &sbuf) == 0 && S_ISLNK(sbuf.st_mode) && php_check_open_basedir(buf TSRMLS_CC)) {
return;
}
data->fd = VCWD_OPEN_MODE(buf, O_CREAT | O_RDWR | O_BINARY, data->filemode);
#endif
if (data->fd != -1) {
#ifndef PHP_WIN32
/* check that this session file was created by us or root we
don't want to end up accepting the sessions of another webapp */
if (fstat(data->fd, &sbuf) || (sbuf.st_uid != 0 && sbuf.st_uid != getuid() && sbuf.st_uid != geteuid())) {
close(data->fd);
data->fd = -1;
return;
}
#endif
do {
ret = flock(data->fd, LOCK_EX);
} while (ret == -1 && errno == EINTR);
#ifdef F_SETFD
# ifndef FD_CLOEXEC
# define FD_CLOEXEC 1
# endif
if (fcntl(data->fd, F_SETFD, FD_CLOEXEC)) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "fcntl(%d, F_SETFD, FD_CLOEXEC) failed: %s (%d)", data->fd, strerror(errno), errno);
}
#endif
} else {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "open(%s, O_RDWR) failed: %s (%d)", buf, strerror(errno), errno);
}
}
}
static int ps_files_cleanup_dir(const char *dirname, int maxlifetime TSRMLS_DC)
{
DIR *dir;
char dentry[sizeof(struct dirent) + MAXPATHLEN];
struct dirent *entry = (struct dirent *) &dentry;
struct stat sbuf;
char buf[MAXPATHLEN];
time_t now;
int nrdels = 0;
size_t dirname_len;
dir = opendir(dirname);
if (!dir) {
php_error_docref(NULL TSRMLS_CC, E_NOTICE, "ps_files_cleanup_dir: opendir(%s) failed: %s (%d)", dirname, strerror(errno), errno);
return (0);
}
time(&now);
dirname_len = strlen(dirname);
/* Prepare buffer (dirname never changes) */
memcpy(buf, dirname, dirname_len);
buf[dirname_len] = PHP_DIR_SEPARATOR;
while (php_readdir_r(dir, (struct dirent *) dentry, &entry) == 0 && entry) {
/* does the file start with our prefix? */
if (!strncmp(entry->d_name, FILE_PREFIX, sizeof(FILE_PREFIX) - 1)) {
size_t entry_len = strlen(entry->d_name);
/* does it fit into our buffer? */
if (entry_len + dirname_len + 2 < MAXPATHLEN) {
/* create the full path.. */
memcpy(buf + dirname_len + 1, entry->d_name, entry_len);
/* NUL terminate it and */
buf[dirname_len + entry_len + 1] = '\0';
/* check whether its last access was more than maxlifetime ago */
if (VCWD_STAT(buf, &sbuf) == 0 &&
(now - sbuf.st_mtime) > maxlifetime) {
VCWD_UNLINK(buf);
nrdels++;
}
}
}
}
closedir(dir);
return (nrdels);
}
static int ps_files_key_exists(ps_files *data, const char *key TSRMLS_DC)
{
char buf[MAXPATHLEN];
struct stat sbuf;
if (!key || !ps_files_path_create(buf, sizeof(buf), data, key)) {
return FAILURE;
}
if (VCWD_STAT(buf, &sbuf)) {
return FAILURE;
}
return SUCCESS;
}
#define PS_FILES_DATA ps_files *data = PS_GET_MOD_DATA()
PS_OPEN_FUNC(files)
{
ps_files *data;
const char *p, *last;
const char *argv[3];
int argc = 0;
size_t dirdepth = 0;
int filemode = 0600;
if (*save_path == '\0') {
/* if save path is an empty string, determine the temporary dir */
save_path = php_get_temporary_directory(TSRMLS_C);
if (php_check_open_basedir(save_path TSRMLS_CC)) {
return FAILURE;
}
}
/* split up input parameter */
last = save_path;
p = strchr(save_path, ';');
while (p) {
argv[argc++] = last;
last = ++p;
p = strchr(p, ';');
if (argc > 1) break;
}
argv[argc++] = last;
if (argc > 1) {
errno = 0;
dirdepth = (size_t) strtol(argv[0], NULL, 10);
if (errno == ERANGE) {
php_error(E_WARNING, "The first parameter in session.save_path is invalid");
return FAILURE;
}
}
if (argc > 2) {
errno = 0;
filemode = strtol(argv[1], NULL, 8);
if (errno == ERANGE || filemode < 0 || filemode > 07777) {
php_error(E_WARNING, "The second parameter in session.save_path is invalid");
return FAILURE;
}
}
save_path = argv[argc - 1];
data = ecalloc(1, sizeof(*data));
data->fd = -1;
data->dirdepth = dirdepth;
data->filemode = filemode;
data->basedir_len = strlen(save_path);
data->basedir = estrndup(save_path, data->basedir_len);
if (PS_GET_MOD_DATA()) {
ps_close_files(mod_data TSRMLS_CC);
}
PS_SET_MOD_DATA(data);
return SUCCESS;
}
PS_CLOSE_FUNC(files)
{
PS_FILES_DATA;
ps_files_close(data);
if (data->lastkey) {
efree(data->lastkey);
}
efree(data->basedir);
efree(data);
*mod_data = NULL;
return SUCCESS;
}
PS_READ_FUNC(files)
{
long n;
struct stat sbuf;
PS_FILES_DATA;
/* If strict mode, check session id existence */
if (PS(use_strict_mode) &&
ps_files_key_exists(data, key TSRMLS_CC) == FAILURE) {
/* key points to PS(id), but cannot change here. */
if (key) {
efree(PS(id));
PS(id) = NULL;
}
PS(id) = PS(mod)->s_create_sid((void **)&data, NULL TSRMLS_CC);
if (!PS(id)) {
return FAILURE;
}
if (PS(use_cookies)) {
PS(send_cookie) = 1;
}
php_session_reset_id(TSRMLS_C);
PS(session_status) = php_session_active;
}
ps_files_open(data, PS(id) TSRMLS_CC);
if (data->fd < 0) {
return FAILURE;
}
if (fstat(data->fd, &sbuf)) {
return FAILURE;
}
data->st_size = *vallen = sbuf.st_size;
if (sbuf.st_size == 0) {
*val = STR_EMPTY_ALLOC();
return SUCCESS;
}
*val = emalloc(sbuf.st_size);
#if defined(HAVE_PREAD)
n = pread(data->fd, *val, sbuf.st_size, 0);
#else
lseek(data->fd, 0, SEEK_SET);
n = read(data->fd, *val, sbuf.st_size);
#endif
if (n != sbuf.st_size) {
if (n == -1) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "read failed: %s (%d)", strerror(errno), errno);
} else {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "read returned less bytes than requested");
}
efree(*val);
return FAILURE;
}
return SUCCESS;
}
PS_WRITE_FUNC(files)
{
long n;
PS_FILES_DATA;
ps_files_open(data, key TSRMLS_CC);
if (data->fd < 0) {
return FAILURE;
}
/* Truncate file if the amount of new data is smaller than the existing data set. */
if (vallen < (int)data->st_size) {
php_ignore_value(ftruncate(data->fd, 0));
}
#if defined(HAVE_PWRITE)
n = pwrite(data->fd, val, vallen, 0);
#else
lseek(data->fd, 0, SEEK_SET);
n = write(data->fd, val, vallen);
#endif
if (n != vallen) {
if (n == -1) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "write failed: %s (%d)", strerror(errno), errno);
} else {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "write wrote less bytes than requested");
}
return FAILURE;
}
return SUCCESS;
}
PS_DESTROY_FUNC(files)
{
char buf[MAXPATHLEN];
PS_FILES_DATA;
if (!ps_files_path_create(buf, sizeof(buf), data, key)) {
return FAILURE;
}
if (data->fd != -1) {
ps_files_close(data);
if (VCWD_UNLINK(buf) == -1) {
/* This is a little safety check for instances when we are dealing with a regenerated session
* that was not yet written to disk. */
if (!VCWD_ACCESS(buf, F_OK)) {
return FAILURE;
}
}
}
return SUCCESS;
}
PS_GC_FUNC(files)
{
PS_FILES_DATA;
/* we don't perform any cleanup, if dirdepth is larger than 0.
we return SUCCESS, since all cleanup should be handled by
an external entity (i.e. find -ctime x | xargs rm) */
if (data->dirdepth == 0) {
*nrdels = ps_files_cleanup_dir(data->basedir, maxlifetime TSRMLS_CC);
}
return SUCCESS;
}
PS_CREATE_SID_FUNC(files)
{
char *sid;
int maxfail = 3;
PS_FILES_DATA;
do {
sid = php_session_create_id((void **)&data, newlen TSRMLS_CC);
/* Check collision */
if (data && ps_files_key_exists(data, sid TSRMLS_CC) == SUCCESS) {
if (sid) {
efree(sid);
sid = NULL;
}
if (!(maxfail--)) {
return NULL;
}
}
} while(!sid);
return sid;
}
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
* vim600: sw=4 ts=4 fdm=marker
* vim<600: sw=4 ts=4
*/