ext/session/mod

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This source file includes following definitions.
ps_files_path_create
ps_files_close
ps_files_open
ps_files_cleanup_dir
ps_files_key_exists
PS_OPEN_FUNC
PS_CLOSE_FUNC
PS_READ_FUNC
PS_WRITE_FUNC
PS_DESTROY_FUNC
PS_GC_FUNC
PS_CREATE_SID_FUNC
   1 /*
   2    +----------------------------------------------------------------------+
   3    | PHP Version 5                                                        |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 1997-2016 The PHP Group                                |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15    | Author: Sascha Schumann <sascha@schumann.cx>                         |
  16    +----------------------------------------------------------------------+
  17  */
  18 
  19 /* $Id$ */
  20 
  21 #include "php.h"
  22 
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 
  26 #if HAVE_SYS_FILE_H
  27 #include <sys/file.h>
  28 #endif
  29 
  30 #if HAVE_DIRENT_H
  31 #include <dirent.h>
  32 #endif
  33 
  34 #ifdef PHP_WIN32
  35 #include "win32/readdir.h"
  36 #endif
  37 #include <time.h>
  38 
  39 #include <fcntl.h>
  40 #include <errno.h>
  41 
  42 #if HAVE_UNISTD_H
  43 #include <unistd.h>
  44 #endif
  45 
  46 #include "php_session.h"
  47 #include "mod_files.h"
  48 #include "ext/standard/flock_compat.h"
  49 #include "php_open_temporary_file.h"
  50 
  51 #define FILE_PREFIX "sess_"
  52 
  53 #ifdef PHP_WIN32
  54 # ifndef O_NOFOLLOW
  55 #  define O_NOFOLLOW 0
  56 # endif
  57 #endif
  58 
  59 typedef struct {
  60         int fd;
  61         char *lastkey;
  62         char *basedir;
  63         size_t basedir_len;
  64         size_t dirdepth;
  65         size_t st_size;
  66         int filemode;
  67 } ps_files;
  68 
  69 ps_module ps_mod_files = {
  70         PS_MOD_SID(files)
  71 };
  72 
  73 
  74 static char *ps_files_path_create(char *buf, size_t buflen, ps_files *data, const char *key)
  75 {
  76         size_t key_len;
  77         const char *p;
  78         int i;
  79         int n;
  80 
  81         key_len = strlen(key);
  82         if (key_len <= data->dirdepth ||
  83                 buflen < (strlen(data->basedir) + 2 * data->dirdepth + key_len + 5 + sizeof(FILE_PREFIX))) {
  84                 return NULL;
  85         }
  86 
  87         p = key;
  88         memcpy(buf, data->basedir, data->basedir_len);
  89         n = data->basedir_len;
  90         buf[n++] = PHP_DIR_SEPARATOR;
  91         for (i = 0; i < (int)data->dirdepth; i++) {
  92                 buf[n++] = *p++;
  93                 buf[n++] = PHP_DIR_SEPARATOR;
  94         }
  95         memcpy(buf + n, FILE_PREFIX, sizeof(FILE_PREFIX) - 1);
  96         n += sizeof(FILE_PREFIX) - 1;
  97         memcpy(buf + n, key, key_len);
  98         n += key_len;
  99         buf[n] = '\0';
 100 
 101         return buf;
 102 }
 103 
 104 #ifndef O_BINARY
 105 # define O_BINARY 0
 106 #endif
 107 
 108 static void ps_files_close(ps_files *data)
 109 {
 110         if (data->fd != -1) {
 111 #ifdef PHP_WIN32
 112                 /* On Win32 locked files that are closed without being explicitly unlocked
 113                    will be unlocked only when "system resources become available". */
 114                 flock(data->fd, LOCK_UN);
 115 #endif
 116                 close(data->fd);
 117                 data->fd = -1;
 118         }
 119 }
 120 
 121 static void ps_files_open(ps_files *data, const char *key TSRMLS_DC)
 122 {
 123         char buf[MAXPATHLEN];
 124         struct stat sbuf;
 125         int ret;
 126 
 127         if (data->fd < 0 || !data->lastkey || strcmp(key, data->lastkey)) {
 128                 if (data->lastkey) {
 129                         efree(data->lastkey);
 130                         data->lastkey = NULL;
 131                 }
 132 
 133                 ps_files_close(data);
 134 
 135                 if (php_session_valid_key(key) == FAILURE) {
 136                         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 '-,'");
 137                         return;
 138                 }
 139 
 140                 if (!ps_files_path_create(buf, sizeof(buf), data, key)) {
 141                         return;
 142                 }
 143 
 144                 data->lastkey = estrdup(key);
 145 
 146                 /* O_NOFOLLOW to prevent us from following evil symlinks */
 147 #ifdef O_NOFOLLOW
 148                 data->fd = VCWD_OPEN_MODE(buf, O_CREAT | O_RDWR | O_BINARY | O_NOFOLLOW, data->filemode);
 149 #else
 150                 /* Check to make sure that the opened file is not outside of allowable dirs. 
 151                    This is not 100% safe but it's hard to do something better without O_NOFOLLOW */
 152                 if(PG(open_basedir) && lstat(buf, &sbuf) == 0 && S_ISLNK(sbuf.st_mode) && php_check_open_basedir(buf TSRMLS_CC)) {
 153                         return;
 154                 }
 155                 data->fd = VCWD_OPEN_MODE(buf, O_CREAT | O_RDWR | O_BINARY, data->filemode);
 156 #endif
 157 
 158                 if (data->fd != -1) {
 159 #ifndef PHP_WIN32
 160                         /* check that this session file was created by us or root – we
 161                            don't want to end up accepting the sessions of another webapp */
 162                         if (fstat(data->fd, &sbuf) || (sbuf.st_uid != 0 && sbuf.st_uid != getuid() && sbuf.st_uid != geteuid())) {
 163                                 close(data->fd);
 164                                 data->fd = -1;
 165                                 return;
 166                         }
 167 #endif
 168                         do {
 169                                 ret = flock(data->fd, LOCK_EX);
 170                         } while (ret == -1 && errno == EINTR);
 171 
 172 #ifdef F_SETFD
 173 # ifndef FD_CLOEXEC
 174 #  define FD_CLOEXEC 1
 175 # endif
 176                         if (fcntl(data->fd, F_SETFD, FD_CLOEXEC)) {
 177                                 php_error_docref(NULL TSRMLS_CC, E_WARNING, "fcntl(%d, F_SETFD, FD_CLOEXEC) failed: %s (%d)", data->fd, strerror(errno), errno);
 178                         }
 179 #endif
 180                 } else {
 181                         php_error_docref(NULL TSRMLS_CC, E_WARNING, "open(%s, O_RDWR) failed: %s (%d)", buf, strerror(errno), errno);
 182                 }
 183         }
 184 }
 185 
 186 static int ps_files_cleanup_dir(const char *dirname, int maxlifetime TSRMLS_DC)
 187 {
 188         DIR *dir;
 189         char dentry[sizeof(struct dirent) + MAXPATHLEN];
 190         struct dirent *entry = (struct dirent *) &dentry;
 191         struct stat sbuf;
 192         char buf[MAXPATHLEN];
 193         time_t now;
 194         int nrdels = 0;
 195         size_t dirname_len;
 196 
 197         dir = opendir(dirname);
 198         if (!dir) {
 199                 php_error_docref(NULL TSRMLS_CC, E_NOTICE, "ps_files_cleanup_dir: opendir(%s) failed: %s (%d)", dirname, strerror(errno), errno);
 200                 return (0);
 201         }
 202 
 203         time(&now);
 204 
 205         dirname_len = strlen(dirname);
 206 
 207         /* Prepare buffer (dirname never changes) */
 208         memcpy(buf, dirname, dirname_len);
 209         buf[dirname_len] = PHP_DIR_SEPARATOR;
 210 
 211         while (php_readdir_r(dir, (struct dirent *) dentry, &entry) == 0 && entry) {
 212                 /* does the file start with our prefix? */
 213                 if (!strncmp(entry->d_name, FILE_PREFIX, sizeof(FILE_PREFIX) - 1)) {
 214                         size_t entry_len = strlen(entry->d_name);
 215 
 216                         /* does it fit into our buffer? */
 217                         if (entry_len + dirname_len + 2 < MAXPATHLEN) {
 218                                 /* create the full path.. */
 219                                 memcpy(buf + dirname_len + 1, entry->d_name, entry_len);
 220 
 221                                 /* NUL terminate it and */
 222                                 buf[dirname_len + entry_len + 1] = '\0';
 223 
 224                                 /* check whether its last access was more than maxlifetime ago */
 225                                 if (VCWD_STAT(buf, &sbuf) == 0 &&
 226                                                 (now - sbuf.st_mtime) > maxlifetime) {
 227                                         VCWD_UNLINK(buf);
 228                                         nrdels++;
 229                                 }
 230                         }
 231                 }
 232         }
 233 
 234         closedir(dir);
 235 
 236         return (nrdels);
 237 }
 238 
 239 static int ps_files_key_exists(ps_files *data, const char *key TSRMLS_DC)
 240 {
 241         char buf[MAXPATHLEN];
 242         struct stat sbuf;
 243 
 244         if (!key || !ps_files_path_create(buf, sizeof(buf), data, key)) {
 245                 return FAILURE;
 246         }
 247         if (VCWD_STAT(buf, &sbuf)) {
 248                 return FAILURE;
 249         }
 250         return SUCCESS;
 251 }
 252 
 253 
 254 #define PS_FILES_DATA ps_files *data = PS_GET_MOD_DATA()
 255 
 256 PS_OPEN_FUNC(files)
 257 {
 258         ps_files *data;
 259         const char *p, *last;
 260         const char *argv[3];
 261         int argc = 0;
 262         size_t dirdepth = 0;
 263         int filemode = 0600;
 264 
 265         if (*save_path == '\0') {
 266                 /* if save path is an empty string, determine the temporary dir */
 267                 save_path = php_get_temporary_directory(TSRMLS_C);
 268 
 269                 if (php_check_open_basedir(save_path TSRMLS_CC)) {
 270                         return FAILURE;
 271                 }
 272         }
 273 
 274         /* split up input parameter */
 275         last = save_path;
 276         p = strchr(save_path, ';');
 277         while (p) {
 278                 argv[argc++] = last;
 279                 last = ++p;
 280                 p = strchr(p, ';');
 281                 if (argc > 1) break;
 282         }
 283         argv[argc++] = last;
 284 
 285         if (argc > 1) {
 286                 errno = 0;
 287                 dirdepth = (size_t) strtol(argv[0], NULL, 10);
 288                 if (errno == ERANGE) {
 289                         php_error(E_WARNING, "The first parameter in session.save_path is invalid");
 290                         return FAILURE;
 291                 }
 292         }
 293 
 294         if (argc > 2) {
 295                 errno = 0;
 296                 filemode = strtol(argv[1], NULL, 8);
 297                 if (errno == ERANGE || filemode < 0 || filemode > 07777) {
 298                         php_error(E_WARNING, "The second parameter in session.save_path is invalid");
 299                         return FAILURE;
 300                 }
 301         }
 302         save_path = argv[argc - 1];
 303 
 304         data = ecalloc(1, sizeof(*data));
 305 
 306         data->fd = -1;
 307         data->dirdepth = dirdepth;
 308         data->filemode = filemode;
 309         data->basedir_len = strlen(save_path);
 310         data->basedir = estrndup(save_path, data->basedir_len);
 311 
 312         if (PS_GET_MOD_DATA()) {
 313                 ps_close_files(mod_data TSRMLS_CC);
 314         }
 315         PS_SET_MOD_DATA(data);
 316 
 317         return SUCCESS;
 318 }
 319 
 320 PS_CLOSE_FUNC(files)
 321 {
 322         PS_FILES_DATA;
 323 
 324         ps_files_close(data);
 325 
 326         if (data->lastkey) {
 327                 efree(data->lastkey);
 328                 data->lastkey = NULL;
 329         }
 330 
 331         efree(data->basedir);
 332         efree(data);
 333         *mod_data = NULL;
 334 
 335         return SUCCESS;
 336 }
 337 
 338 PS_READ_FUNC(files)
 339 {
 340         long n;
 341         struct stat sbuf;
 342         PS_FILES_DATA;
 343 
 344         /* If strict mode, check session id existence */
 345         if (PS(use_strict_mode) &&
 346                 ps_files_key_exists(data, key TSRMLS_CC) == FAILURE) {
 347                 /* key points to PS(id), but cannot change here. */
 348                 if (key) {
 349                         efree(PS(id));
 350                         PS(id) = NULL;
 351                 }
 352                 PS(id) = PS(mod)->s_create_sid((void **)&data, NULL TSRMLS_CC);
 353                 if (!PS(id)) {
 354                         return FAILURE;
 355                 }
 356                 if (PS(use_cookies)) {
 357                         PS(send_cookie) = 1;
 358                 }
 359                 php_session_reset_id(TSRMLS_C);
 360                 PS(session_status) = php_session_active;
 361         }
 362 
 363         if (!PS(id)) {
 364                 return FAILURE;
 365         }
 366 
 367         ps_files_open(data, PS(id) TSRMLS_CC);
 368         if (data->fd < 0) {
 369                 return FAILURE;
 370         }
 371 
 372         if (fstat(data->fd, &sbuf)) {
 373                 return FAILURE;
 374         }
 375 
 376         data->st_size = *vallen = sbuf.st_size;
 377 
 378         if (sbuf.st_size == 0) {
 379                 *val = STR_EMPTY_ALLOC();
 380                 return SUCCESS;
 381         }
 382 
 383         *val = emalloc(sbuf.st_size);
 384 
 385 #if defined(HAVE_PREAD)
 386         n = pread(data->fd, *val, sbuf.st_size, 0);
 387 #else
 388         lseek(data->fd, 0, SEEK_SET);
 389         n = read(data->fd, *val, sbuf.st_size);
 390 #endif
 391 
 392         if (n != sbuf.st_size) {
 393                 if (n == -1) {
 394                         php_error_docref(NULL TSRMLS_CC, E_WARNING, "read failed: %s (%d)", strerror(errno), errno);
 395                 } else {
 396                         php_error_docref(NULL TSRMLS_CC, E_WARNING, "read returned less bytes than requested");
 397                 }
 398                 efree(*val);
 399                 return FAILURE;
 400         }
 401 
 402         return SUCCESS;
 403 }
 404 
 405 PS_WRITE_FUNC(files)
 406 {
 407         long n;
 408         PS_FILES_DATA;
 409 
 410         ps_files_open(data, key TSRMLS_CC);
 411         if (data->fd < 0) {
 412                 return FAILURE;
 413         }
 414 
 415         /* Truncate file if the amount of new data is smaller than the existing data set. */
 416 
 417         if (vallen < (int)data->st_size) {
 418                 php_ignore_value(ftruncate(data->fd, 0));
 419         }
 420 
 421 #if defined(HAVE_PWRITE)
 422         n = pwrite(data->fd, val, vallen, 0);
 423 #else
 424         lseek(data->fd, 0, SEEK_SET);
 425         n = write(data->fd, val, vallen);
 426 #endif
 427 
 428         if (n != vallen) {
 429                 if (n == -1) {
 430                         php_error_docref(NULL TSRMLS_CC, E_WARNING, "write failed: %s (%d)", strerror(errno), errno);
 431                 } else {
 432                         php_error_docref(NULL TSRMLS_CC, E_WARNING, "write wrote less bytes than requested");
 433                 }
 434                 return FAILURE;
 435         }
 436 
 437         return SUCCESS;
 438 }
 439 
 440 PS_DESTROY_FUNC(files)
 441 {
 442         char buf[MAXPATHLEN];
 443         PS_FILES_DATA;
 444 
 445         if (!ps_files_path_create(buf, sizeof(buf), data, key)) {
 446                 return FAILURE;
 447         }
 448 
 449         if (data->fd != -1) {
 450                 ps_files_close(data);
 451 
 452                 if (VCWD_UNLINK(buf) == -1) {
 453                         /* This is a little safety check for instances when we are dealing with a regenerated session
 454                          * that was not yet written to disk. */
 455                         if (!VCWD_ACCESS(buf, F_OK)) {
 456                                 return FAILURE;
 457                         }
 458                 }
 459         }
 460 
 461         return SUCCESS;
 462 }
 463 
 464 PS_GC_FUNC(files)
 465 {
 466         PS_FILES_DATA;
 467 
 468         /* we don't perform any cleanup, if dirdepth is larger than 0.
 469            we return SUCCESS, since all cleanup should be handled by
 470            an external entity (i.e. find -ctime x | xargs rm) */
 471 
 472         if (data->dirdepth == 0) {
 473                 *nrdels = ps_files_cleanup_dir(data->basedir, maxlifetime TSRMLS_CC);
 474         }
 475 
 476         return SUCCESS;
 477 }
 478 
 479 PS_CREATE_SID_FUNC(files)
 480 {
 481         char *sid;
 482         int maxfail = 3;
 483         PS_FILES_DATA;
 484 
 485         do {
 486                 sid = php_session_create_id((void **)&data, newlen TSRMLS_CC);
 487                 /* Check collision */
 488                 if (data && ps_files_key_exists(data, sid TSRMLS_CC) == SUCCESS) {
 489                         if (sid) {
 490                                 efree(sid);
 491                                 sid = NULL;
 492                         }
 493                         if (!(maxfail--)) {
 494                                 return NULL;
 495                         }
 496                 }
 497         } while(!sid);
 498 
 499         return sid;
 500 }
 501 
 502 
 503 /*
 504  * Local variables:
 505  * tab-width: 4
 506  * c-basic-offset: 4
 507  * End:
 508  * vim600: sw=4 ts=4 fdm=marker
 509  * vim<600: sw=4 ts=4
 510  */
/* [<][>][^][v][top][bottom][index][help] */
root/ext/session/mod_files.c

DEFINITIONS
