1 /*
2 +----------------------------------------------------------------------+
3 | PHP Version 7 |
4 +----------------------------------------------------------------------+
5 | Copyright (c) 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 #include "php.h"
20
21 #ifdef HAVE_LIBMM
22
23 #include <unistd.h>
24 #include <mm.h>
25 #include <time.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <fcntl.h>
29
30 #include "php_stdint.h"
31 #include "php_session.h"
32 #include "mod_mm.h"
33 #include "SAPI.h"
34
35 #ifdef ZTS
36 # error mm is not thread-safe
37 #endif
38
39 #define PS_MM_FILE "session_mm_"
40
41 /* This list holds all data associated with one session. */
42
43 typedef struct ps_sd {
44 struct ps_sd *next;
45 uint32_t hv; /* hash value of key */
46 time_t ctime; /* time of last change */
47 void *data;
48 size_t datalen; /* amount of valid data */
49 size_t alloclen; /* amount of allocated memory for data */
50 char key[1]; /* inline key */
51 } ps_sd;
52
53 typedef struct {
54 MM *mm;
55 ps_sd **hash;
56 uint32_t hash_max;
57 uint32_t hash_cnt;
58 pid_t owner;
59 } ps_mm;
60
61 static ps_mm *ps_mm_instance = NULL;
62
63 #if 0
64 # define ps_mm_debug(a) printf a
65 #else
66 # define ps_mm_debug(a)
67 #endif
68
ps_sd_hash(const char * data,int len)69 static inline uint32_t ps_sd_hash(const char *data, int len)
70 {
71 uint32_t h;
72 const char *e = data + len;
73
74 for (h = 2166136261U; data < e; ) {
75 h *= 16777619;
76 h ^= *data++;
77 }
78
79 return h;
80 }
81
hash_split(ps_mm * data)82 static void hash_split(ps_mm *data)
83 {
84 uint32_t nmax;
85 ps_sd **nhash;
86 ps_sd **ohash, **ehash;
87 ps_sd *ps, *next;
88
89 nmax = ((data->hash_max + 1) << 1) - 1;
90 nhash = mm_calloc(data->mm, nmax + 1, sizeof(*data->hash));
91
92 if (!nhash) {
93 /* no further memory to expand hash table */
94 return;
95 }
96
97 ehash = data->hash + data->hash_max + 1;
98 for (ohash = data->hash; ohash < ehash; ohash++) {
99 for (ps = *ohash; ps; ps = next) {
100 next = ps->next;
101 ps->next = nhash[ps->hv & nmax];
102 nhash[ps->hv & nmax] = ps;
103 }
104 }
105 mm_free(data->mm, data->hash);
106
107 data->hash = nhash;
108 data->hash_max = nmax;
109 }
110
ps_sd_new(ps_mm * data,const char * key)111 static ps_sd *ps_sd_new(ps_mm *data, const char *key)
112 {
113 uint32_t hv, slot;
114 ps_sd *sd;
115 int keylen;
116
117 keylen = strlen(key);
118
119 sd = mm_malloc(data->mm, sizeof(ps_sd) + keylen);
120 if (!sd) {
121
122 php_error_docref(NULL, E_WARNING, "mm_malloc failed, avail %ld, err %s", mm_available(data->mm), mm_error());
123 return NULL;
124 }
125
126 hv = ps_sd_hash(key, keylen);
127 slot = hv & data->hash_max;
128
129 sd->ctime = 0;
130 sd->hv = hv;
131 sd->data = NULL;
132 sd->alloclen = sd->datalen = 0;
133
134 memcpy(sd->key, key, keylen + 1);
135
136 sd->next = data->hash[slot];
137 data->hash[slot] = sd;
138
139 data->hash_cnt++;
140
141 if (!sd->next) {
142 if (data->hash_cnt >= data->hash_max) {
143 hash_split(data);
144 }
145 }
146
147 ps_mm_debug(("inserting %s(%p) into slot %d\n", key, sd, slot));
148
149 return sd;
150 }
151
ps_sd_destroy(ps_mm * data,ps_sd * sd)152 static void ps_sd_destroy(ps_mm *data, ps_sd *sd)
153 {
154 uint32_t slot;
155
156 slot = ps_sd_hash(sd->key, strlen(sd->key)) & data->hash_max;
157
158 if (data->hash[slot] == sd) {
159 data->hash[slot] = sd->next;
160 } else {
161 ps_sd *prev;
162
163 /* There must be some entry before the one we want to delete */
164 for (prev = data->hash[slot]; prev->next != sd; prev = prev->next);
165 prev->next = sd->next;
166 }
167
168 data->hash_cnt--;
169
170 if (sd->data) {
171 mm_free(data->mm, sd->data);
172 }
173
174 mm_free(data->mm, sd);
175 }
176
ps_sd_lookup(ps_mm * data,const char * key,int rw)177 static ps_sd *ps_sd_lookup(ps_mm *data, const char *key, int rw)
178 {
179 uint32_t hv, slot;
180 ps_sd *ret, *prev;
181
182 hv = ps_sd_hash(key, strlen(key));
183 slot = hv & data->hash_max;
184
185 for (prev = NULL, ret = data->hash[slot]; ret; prev = ret, ret = ret->next) {
186 if (ret->hv == hv && !strcmp(ret->key, key)) {
187 break;
188 }
189 }
190
191 if (ret && rw && ret != data->hash[slot]) {
192 /* Move the entry to the top of the linked list */
193 if (prev) {
194 prev->next = ret->next;
195 }
196
197 ret->next = data->hash[slot];
198 data->hash[slot] = ret;
199 }
200
201 ps_mm_debug(("lookup(%s): ret=%p,hv=%u,slot=%d\n", key, ret, hv, slot));
202
203 return ret;
204 }
205
ps_mm_key_exists(ps_mm * data,const char * key)206 static int ps_mm_key_exists(ps_mm *data, const char *key)
207 {
208 ps_sd *sd;
209
210 if (!key) {
211 return FAILURE;
212 }
213 sd = ps_sd_lookup(data, key, 0);
214 if (sd) {
215 return SUCCESS;
216 }
217 return FAILURE;
218 }
219
220 const ps_module ps_mod_mm = {
221 PS_MOD_SID(mm)
222 };
223
224 #define PS_MM_DATA ps_mm *data = PS_GET_MOD_DATA()
225
ps_mm_initialize(ps_mm * data,const char * path)226 static int ps_mm_initialize(ps_mm *data, const char *path)
227 {
228 data->owner = getpid();
229 data->mm = mm_create(0, path);
230 if (!data->mm) {
231 return FAILURE;
232 }
233
234 data->hash_cnt = 0;
235 data->hash_max = 511;
236 data->hash = mm_calloc(data->mm, data->hash_max + 1, sizeof(ps_sd *));
237 if (!data->hash) {
238 mm_destroy(data->mm);
239 return FAILURE;
240 }
241
242 return SUCCESS;
243 }
244
ps_mm_destroy(ps_mm * data)245 static void ps_mm_destroy(ps_mm *data)
246 {
247 int h;
248 ps_sd *sd, *next;
249
250 /* This function is called during each module shutdown,
251 but we must not release the shared memory pool, when
252 an Apache child dies! */
253 if (data->owner != getpid()) {
254 return;
255 }
256
257 for (h = 0; h < data->hash_max + 1; h++) {
258 for (sd = data->hash[h]; sd; sd = next) {
259 next = sd->next;
260 ps_sd_destroy(data, sd);
261 }
262 }
263
264 mm_free(data->mm, data->hash);
265 mm_destroy(data->mm);
266 free(data);
267 }
268
PHP_MINIT_FUNCTION(ps_mm)269 PHP_MINIT_FUNCTION(ps_mm)
270 {
271 int save_path_len = strlen(PS(save_path));
272 int mod_name_len = strlen(sapi_module.name);
273 int euid_len;
274 char *ps_mm_path, euid[30];
275 int ret;
276
277 ps_mm_instance = calloc(sizeof(*ps_mm_instance), 1);
278 if (!ps_mm_instance) {
279 return FAILURE;
280 }
281
282 if (!(euid_len = slprintf(euid, sizeof(euid), "%d", geteuid()))) {
283 free(ps_mm_instance);
284 ps_mm_instance = NULL;
285 return FAILURE;
286 }
287
288 /* Directory + '/' + File + Module Name + Effective UID + \0 */
289 ps_mm_path = emalloc(save_path_len + 1 + (sizeof(PS_MM_FILE) - 1) + mod_name_len + euid_len + 1);
290
291 memcpy(ps_mm_path, PS(save_path), save_path_len);
292 if (save_path_len && PS(save_path)[save_path_len - 1] != DEFAULT_SLASH) {
293 ps_mm_path[save_path_len] = DEFAULT_SLASH;
294 save_path_len++;
295 }
296 memcpy(ps_mm_path + save_path_len, PS_MM_FILE, sizeof(PS_MM_FILE) - 1);
297 save_path_len += sizeof(PS_MM_FILE) - 1;
298 memcpy(ps_mm_path + save_path_len, sapi_module.name, mod_name_len);
299 save_path_len += mod_name_len;
300 memcpy(ps_mm_path + save_path_len, euid, euid_len);
301 ps_mm_path[save_path_len + euid_len] = '\0';
302
303 ret = ps_mm_initialize(ps_mm_instance, ps_mm_path);
304
305 efree(ps_mm_path);
306
307 if (ret != SUCCESS) {
308 free(ps_mm_instance);
309 ps_mm_instance = NULL;
310 return FAILURE;
311 }
312
313 php_session_register_module(&ps_mod_mm);
314 return SUCCESS;
315 }
316
PHP_MSHUTDOWN_FUNCTION(ps_mm)317 PHP_MSHUTDOWN_FUNCTION(ps_mm)
318 {
319 if (ps_mm_instance) {
320 ps_mm_destroy(ps_mm_instance);
321 return SUCCESS;
322 }
323 return FAILURE;
324 }
325
PS_OPEN_FUNC(mm)326 PS_OPEN_FUNC(mm)
327 {
328 ps_mm_debug(("open: ps_mm_instance=%p\n", ps_mm_instance));
329
330 if (!ps_mm_instance) {
331 return FAILURE;
332 }
333 PS_SET_MOD_DATA(ps_mm_instance);
334
335 return SUCCESS;
336 }
337
PS_CLOSE_FUNC(mm)338 PS_CLOSE_FUNC(mm)
339 {
340 PS_SET_MOD_DATA(NULL);
341
342 return SUCCESS;
343 }
344
PS_READ_FUNC(mm)345 PS_READ_FUNC(mm)
346 {
347 PS_MM_DATA;
348 ps_sd *sd;
349 int ret = FAILURE;
350
351 mm_lock(data->mm, MM_LOCK_RD);
352
353 /* If there is an ID and strict mode, verify existence */
354 if (PS(use_strict_mode)
355 && ps_mm_key_exists(data, key->val) == FAILURE) {
356 /* key points to PS(id), but cannot change here. */
357 if (key) {
358 efree(PS(id));
359 PS(id) = NULL;
360 }
361 PS(id) = PS(mod)->s_create_sid((void **)&data);
362 if (!PS(id)) {
363 return FAILURE;
364 }
365 if (PS(use_cookies)) {
366 PS(send_cookie) = 1;
367 }
368 php_session_reset_id();
369 PS(session_status) = php_session_active;
370 }
371
372 sd = ps_sd_lookup(data, PS(id)->val, 0);
373 if (sd) {
374 *val = zend_string_init(sd->data, sd->datalen, 0);
375 ret = SUCCESS;
376 }
377
378 mm_unlock(data->mm);
379
380 return ret;
381 }
382
PS_WRITE_FUNC(mm)383 PS_WRITE_FUNC(mm)
384 {
385 PS_MM_DATA;
386 ps_sd *sd;
387
388 mm_lock(data->mm, MM_LOCK_RW);
389
390 sd = ps_sd_lookup(data, key->val, 1);
391 if (!sd) {
392 sd = ps_sd_new(data, key->val);
393 ps_mm_debug(("new entry for %s\n", key->val));
394 }
395
396 if (sd) {
397 if (val->len >= sd->alloclen) {
398 if (data->mm) {
399 mm_free(data->mm, sd->data);
400 }
401 sd->alloclen = val->len + 1;
402 sd->data = mm_malloc(data->mm, sd->alloclen);
403
404 if (!sd->data) {
405 ps_sd_destroy(data, sd);
406 php_error_docref(NULL, E_WARNING, "cannot allocate new data segment");
407 sd = NULL;
408 }
409 }
410 if (sd) {
411 sd->datalen = val->len;
412 memcpy(sd->data, val->val, val->len);
413 time(&sd->ctime);
414 }
415 }
416
417 mm_unlock(data->mm);
418
419 return sd ? SUCCESS : FAILURE;
420 }
421
PS_DESTROY_FUNC(mm)422 PS_DESTROY_FUNC(mm)
423 {
424 PS_MM_DATA;
425 ps_sd *sd;
426
427 mm_lock(data->mm, MM_LOCK_RW);
428
429 sd = ps_sd_lookup(data, key->val, 0);
430 if (sd) {
431 ps_sd_destroy(data, sd);
432 }
433
434 mm_unlock(data->mm);
435
436 return SUCCESS;
437 }
438
PS_GC_FUNC(mm)439 PS_GC_FUNC(mm)
440 {
441 PS_MM_DATA;
442 time_t limit;
443 ps_sd **ohash, **ehash;
444 ps_sd *sd, *next;
445
446 *nrdels = 0;
447 ps_mm_debug(("gc\n"));
448
449 time(&limit);
450
451 limit -= maxlifetime;
452
453 mm_lock(data->mm, MM_LOCK_RW);
454
455 ehash = data->hash + data->hash_max + 1;
456 for (ohash = data->hash; ohash < ehash; ohash++) {
457 for (sd = *ohash; sd; sd = next) {
458 next = sd->next;
459 if (sd->ctime < limit) {
460 ps_mm_debug(("purging %s\n", sd->key));
461 ps_sd_destroy(data, sd);
462 (*nrdels)++;
463 }
464 }
465 }
466
467 mm_unlock(data->mm);
468
469 return *nrdels;
470 }
471
PS_CREATE_SID_FUNC(mm)472 PS_CREATE_SID_FUNC(mm)
473 {
474 zend_string *sid;
475 int maxfail = 3;
476 PS_MM_DATA;
477
478 do {
479 sid = php_session_create_id((void **)&data);
480 /* Check collision */
481 if (ps_mm_key_exists(data, sid->val) == SUCCESS) {
482 if (sid) {
483 zend_string_release_ex(sid, 0);
484 sid = NULL;
485 }
486 if (!(maxfail--)) {
487 return NULL;
488 }
489 }
490 } while(!sid);
491
492 return sid;
493 }
494
495 #endif
496
