1 /*
2 +----------------------------------------------------------------------+
3 | PHP Version 7 |
4 +----------------------------------------------------------------------+
5 | Copyright (c) 1997-2018 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 #ifdef HAVE_LIBMM
24
25 #include <unistd.h>
26 #include <mm.h>
27 #include <time.h>
28 #include <sys/stat.h>
29 #include <sys/types.h>
30 #include <fcntl.h>
31
32 #include "php_stdint.h"
33 #include "php_session.h"
34 #include "mod_mm.h"
35 #include "SAPI.h"
36
37 #ifdef ZTS
38 # error mm is not thread-safe
39 #endif
40
41 #define PS_MM_FILE "session_mm_"
42
43 /* This list holds all data associated with one session. */
44
45 typedef struct ps_sd {
46 struct ps_sd *next;
47 uint32_t hv; /* hash value of key */
48 time_t ctime; /* time of last change */
49 void *data;
50 size_t datalen; /* amount of valid data */
51 size_t alloclen; /* amount of allocated memory for data */
52 char key[1]; /* inline key */
53 } ps_sd;
54
55 typedef struct {
56 MM *mm;
57 ps_sd **hash;
58 uint32_t hash_max;
59 uint32_t hash_cnt;
60 pid_t owner;
61 } ps_mm;
62
63 static ps_mm *ps_mm_instance = NULL;
64
65 #if 0
66 # define ps_mm_debug(a) printf a
67 #else
68 # define ps_mm_debug(a)
69 #endif
70
ps_sd_hash(const char * data,int len)71 static inline uint32_t ps_sd_hash(const char *data, int len)
72 {
73 uint32_t h;
74 const char *e = data + len;
75
76 for (h = 2166136261U; data < e; ) {
77 h *= 16777619;
78 h ^= *data++;
79 }
80
81 return h;
82 }
83
hash_split(ps_mm * data)84 static void hash_split(ps_mm *data)
85 {
86 uint32_t nmax;
87 ps_sd **nhash;
88 ps_sd **ohash, **ehash;
89 ps_sd *ps, *next;
90
91 nmax = ((data->hash_max + 1) << 1) - 1;
92 nhash = mm_calloc(data->mm, nmax + 1, sizeof(*data->hash));
93
94 if (!nhash) {
95 /* no further memory to expand hash table */
96 return;
97 }
98
99 ehash = data->hash + data->hash_max + 1;
100 for (ohash = data->hash; ohash < ehash; ohash++) {
101 for (ps = *ohash; ps; ps = next) {
102 next = ps->next;
103 ps->next = nhash[ps->hv & nmax];
104 nhash[ps->hv & nmax] = ps;
105 }
106 }
107 mm_free(data->mm, data->hash);
108
109 data->hash = nhash;
110 data->hash_max = nmax;
111 }
112
ps_sd_new(ps_mm * data,const char * key)113 static ps_sd *ps_sd_new(ps_mm *data, const char *key)
114 {
115 uint32_t hv, slot;
116 ps_sd *sd;
117 int keylen;
118
119 keylen = strlen(key);
120
121 sd = mm_malloc(data->mm, sizeof(ps_sd) + keylen);
122 if (!sd) {
123
124 php_error_docref(NULL, E_WARNING, "mm_malloc failed, avail %ld, err %s", mm_available(data->mm), mm_error());
125 return NULL;
126 }
127
128 hv = ps_sd_hash(key, keylen);
129 slot = hv & data->hash_max;
130
131 sd->ctime = 0;
132 sd->hv = hv;
133 sd->data = NULL;
134 sd->alloclen = sd->datalen = 0;
135
136 memcpy(sd->key, key, keylen + 1);
137
138 sd->next = data->hash[slot];
139 data->hash[slot] = sd;
140
141 data->hash_cnt++;
142
143 if (!sd->next) {
144 if (data->hash_cnt >= data->hash_max) {
145 hash_split(data);
146 }
147 }
148
149 ps_mm_debug(("inserting %s(%p) into slot %d\n", key, sd, slot));
150
151 return sd;
152 }
153
ps_sd_destroy(ps_mm * data,ps_sd * sd)154 static void ps_sd_destroy(ps_mm *data, ps_sd *sd)
155 {
156 uint32_t slot;
157
158 slot = ps_sd_hash(sd->key, strlen(sd->key)) & data->hash_max;
159
160 if (data->hash[slot] == sd) {
161 data->hash[slot] = sd->next;
162 } else {
163 ps_sd *prev;
164
165 /* There must be some entry before the one we want to delete */
166 for (prev = data->hash[slot]; prev->next != sd; prev = prev->next);
167 prev->next = sd->next;
168 }
169
170 data->hash_cnt--;
171
172 if (sd->data) {
173 mm_free(data->mm, sd->data);
174 }
175
176 mm_free(data->mm, sd);
177 }
178
ps_sd_lookup(ps_mm * data,const char * key,int rw)179 static ps_sd *ps_sd_lookup(ps_mm *data, const char *key, int rw)
180 {
181 uint32_t hv, slot;
182 ps_sd *ret, *prev;
183
184 hv = ps_sd_hash(key, strlen(key));
185 slot = hv & data->hash_max;
186
187 for (prev = NULL, ret = data->hash[slot]; ret; prev = ret, ret = ret->next) {
188 if (ret->hv == hv && !strcmp(ret->key, key)) {
189 break;
190 }
191 }
192
193 if (ret && rw && ret != data->hash[slot]) {
194 /* Move the entry to the top of the linked list */
195 if (prev) {
196 prev->next = ret->next;
197 }
198
199 ret->next = data->hash[slot];
200 data->hash[slot] = ret;
201 }
202
203 ps_mm_debug(("lookup(%s): ret=%p,hv=%u,slot=%d\n", key, ret, hv, slot));
204
205 return ret;
206 }
207
ps_mm_key_exists(ps_mm * data,const char * key)208 static int ps_mm_key_exists(ps_mm *data, const char *key)
209 {
210 ps_sd *sd;
211
212 if (!key) {
213 return FAILURE;
214 }
215 sd = ps_sd_lookup(data, key, 0);
216 if (sd) {
217 return SUCCESS;
218 }
219 return FAILURE;
220 }
221
222 ps_module ps_mod_mm = {
223 PS_MOD_SID(mm)
224 };
225
226 #define PS_MM_DATA ps_mm *data = PS_GET_MOD_DATA()
227
ps_mm_initialize(ps_mm * data,const char * path)228 static int ps_mm_initialize(ps_mm *data, const char *path)
229 {
230 data->owner = getpid();
231 data->mm = mm_create(0, path);
232 if (!data->mm) {
233 return FAILURE;
234 }
235
236 data->hash_cnt = 0;
237 data->hash_max = 511;
238 data->hash = mm_calloc(data->mm, data->hash_max + 1, sizeof(ps_sd *));
239 if (!data->hash) {
240 mm_destroy(data->mm);
241 return FAILURE;
242 }
243
244 return SUCCESS;
245 }
246
ps_mm_destroy(ps_mm * data)247 static void ps_mm_destroy(ps_mm *data)
248 {
249 int h;
250 ps_sd *sd, *next;
251
252 /* This function is called during each module shutdown,
253 but we must not release the shared memory pool, when
254 an Apache child dies! */
255 if (data->owner != getpid()) {
256 return;
257 }
258
259 for (h = 0; h < data->hash_max + 1; h++) {
260 for (sd = data->hash[h]; sd; sd = next) {
261 next = sd->next;
262 ps_sd_destroy(data, sd);
263 }
264 }
265
266 mm_free(data->mm, data->hash);
267 mm_destroy(data->mm);
268 free(data);
269 }
270
PHP_MINIT_FUNCTION(ps_mm)271 PHP_MINIT_FUNCTION(ps_mm)
272 {
273 int save_path_len = strlen(PS(save_path));
274 int mod_name_len = strlen(sapi_module.name);
275 int euid_len;
276 char *ps_mm_path, euid[30];
277 int ret;
278
279 ps_mm_instance = calloc(sizeof(*ps_mm_instance), 1);
280 if (!ps_mm_instance) {
281 return FAILURE;
282 }
283
284 if (!(euid_len = slprintf(euid, sizeof(euid), "%d", geteuid()))) {
285 free(ps_mm_instance);
286 ps_mm_instance = NULL;
287 return FAILURE;
288 }
289
290 /* Directory + '/' + File + Module Name + Effective UID + \0 */
291 ps_mm_path = emalloc(save_path_len + 1 + (sizeof(PS_MM_FILE) - 1) + mod_name_len + euid_len + 1);
292
293 memcpy(ps_mm_path, PS(save_path), save_path_len);
294 if (save_path_len && PS(save_path)[save_path_len - 1] != DEFAULT_SLASH) {
295 ps_mm_path[save_path_len] = DEFAULT_SLASH;
296 save_path_len++;
297 }
298 memcpy(ps_mm_path + save_path_len, PS_MM_FILE, sizeof(PS_MM_FILE) - 1);
299 save_path_len += sizeof(PS_MM_FILE) - 1;
300 memcpy(ps_mm_path + save_path_len, sapi_module.name, mod_name_len);
301 save_path_len += mod_name_len;
302 memcpy(ps_mm_path + save_path_len, euid, euid_len);
303 ps_mm_path[save_path_len + euid_len] = '\0';
304
305 ret = ps_mm_initialize(ps_mm_instance, ps_mm_path);
306
307 efree(ps_mm_path);
308
309 if (ret != SUCCESS) {
310 free(ps_mm_instance);
311 ps_mm_instance = NULL;
312 return FAILURE;
313 }
314
315 php_session_register_module(&ps_mod_mm);
316 return SUCCESS;
317 }
318
PHP_MSHUTDOWN_FUNCTION(ps_mm)319 PHP_MSHUTDOWN_FUNCTION(ps_mm)
320 {
321 if (ps_mm_instance) {
322 ps_mm_destroy(ps_mm_instance);
323 return SUCCESS;
324 }
325 return FAILURE;
326 }
327
PS_OPEN_FUNC(mm)328 PS_OPEN_FUNC(mm)
329 {
330 ps_mm_debug(("open: ps_mm_instance=%p\n", ps_mm_instance));
331
332 if (!ps_mm_instance) {
333 return FAILURE;
334 }
335 PS_SET_MOD_DATA(ps_mm_instance);
336
337 return SUCCESS;
338 }
339
PS_CLOSE_FUNC(mm)340 PS_CLOSE_FUNC(mm)
341 {
342 PS_SET_MOD_DATA(NULL);
343
344 return SUCCESS;
345 }
346
PS_READ_FUNC(mm)347 PS_READ_FUNC(mm)
348 {
349 PS_MM_DATA;
350 ps_sd *sd;
351 int ret = FAILURE;
352
353 mm_lock(data->mm, MM_LOCK_RD);
354
355 /* If there is an ID and strict mode, verify existence */
356 if (PS(use_strict_mode)
357 && ps_mm_key_exists(data, key->val) == FAILURE) {
358 /* key points to PS(id), but cannot change here. */
359 if (key) {
360 efree(PS(id));
361 PS(id) = NULL;
362 }
363 PS(id) = PS(mod)->s_create_sid((void **)&data);
364 if (!PS(id)) {
365 return FAILURE;
366 }
367 if (PS(use_cookies)) {
368 PS(send_cookie) = 1;
369 }
370 php_session_reset_id();
371 PS(session_status) = php_session_active;
372 }
373
374 sd = ps_sd_lookup(data, PS(id)->val, 0);
375 if (sd) {
376 *val = zend_string_init(sd->data, sd->datalen, 0);
377 ret = SUCCESS;
378 }
379
380 mm_unlock(data->mm);
381
382 return ret;
383 }
384
PS_WRITE_FUNC(mm)385 PS_WRITE_FUNC(mm)
386 {
387 PS_MM_DATA;
388 ps_sd *sd;
389
390 mm_lock(data->mm, MM_LOCK_RW);
391
392 sd = ps_sd_lookup(data, key->val, 1);
393 if (!sd) {
394 sd = ps_sd_new(data, key->val);
395 ps_mm_debug(("new entry for %s\n", key->val));
396 }
397
398 if (sd) {
399 if (val->len >= sd->alloclen) {
400 if (data->mm) {
401 mm_free(data->mm, sd->data);
402 }
403 sd->alloclen = val->len + 1;
404 sd->data = mm_malloc(data->mm, sd->alloclen);
405
406 if (!sd->data) {
407 ps_sd_destroy(data, sd);
408 php_error_docref(NULL, E_WARNING, "cannot allocate new data segment");
409 sd = NULL;
410 }
411 }
412 if (sd) {
413 sd->datalen = val->len;
414 memcpy(sd->data, val->val, val->len);
415 time(&sd->ctime);
416 }
417 }
418
419 mm_unlock(data->mm);
420
421 return sd ? SUCCESS : FAILURE;
422 }
423
PS_DESTROY_FUNC(mm)424 PS_DESTROY_FUNC(mm)
425 {
426 PS_MM_DATA;
427 ps_sd *sd;
428
429 mm_lock(data->mm, MM_LOCK_RW);
430
431 sd = ps_sd_lookup(data, key->val, 0);
432 if (sd) {
433 ps_sd_destroy(data, sd);
434 }
435
436 mm_unlock(data->mm);
437
438 return SUCCESS;
439 }
440
PS_GC_FUNC(mm)441 PS_GC_FUNC(mm)
442 {
443 PS_MM_DATA;
444 time_t limit;
445 ps_sd **ohash, **ehash;
446 ps_sd *sd, *next;
447
448 *nrdels = 0;
449 ps_mm_debug(("gc\n"));
450
451 time(&limit);
452
453 limit -= maxlifetime;
454
455 mm_lock(data->mm, MM_LOCK_RW);
456
457 ehash = data->hash + data->hash_max + 1;
458 for (ohash = data->hash; ohash < ehash; ohash++) {
459 for (sd = *ohash; sd; sd = next) {
460 next = sd->next;
461 if (sd->ctime < limit) {
462 ps_mm_debug(("purging %s\n", sd->key));
463 ps_sd_destroy(data, sd);
464 (*nrdels)++;
465 }
466 }
467 }
468
469 mm_unlock(data->mm);
470
471 return nrdels;
472 }
473
PS_CREATE_SID_FUNC(mm)474 PS_CREATE_SID_FUNC(mm)
475 {
476 zend_string *sid;
477 int maxfail = 3;
478 PS_MM_DATA;
479
480 do {
481 sid = php_session_create_id((void **)&data);
482 /* Check collision */
483 if (ps_mm_key_exists(data, sid->val) == SUCCESS) {
484 if (sid) {
485 zend_string_release(sid);
486 sid = NULL;
487 }
488 if (!(maxfail--)) {
489 return NULL;
490 }
491 }
492 } while(!sid);
493
494 return sid;
495 }
496
497 #endif
498
499 /*
500 * Local variables:
501 * tab-width: 4
502 * c-basic-offset: 4
503 * End:
504 * vim600: sw=4 ts=4 fdm=marker
505 * vim<600: sw=4 ts=4
506 */
507
