lib/liblwip/core/memp.c

   1 /**
   2  * @file
   3  * Dynamic pool memory manager
   4  *
   5  * lwIP has dedicated pools for many structures (netconn, protocol control blocks,
   6  * packet buffers, ...). All these pools are managed here.
   7  */
   8
   9 /*
  10  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
  11  * All rights reserved.
  12  *
  13  * Redistribution and use in source and binary forms, with or without modification,
  14  * are permitted provided that the following conditions are met:
  15  *
  16  * 1. Redistributions of source code must retain the above copyright notice,
  17  *    this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright notice,
  19  *    this list of conditions and the following disclaimer in the documentation
  20  *    and/or other materials provided with the distribution.
  21  * 3. The name of the author may not be used to endorse or promote products
  22  *    derived from this software without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  25  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  27  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  28  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  29  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  32  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  33  * OF SUCH DAMAGE.
  34  *
  35  * This file is part of the lwIP TCP/IP stack.
  36  *
  37  * Author: Adam Dunkels <adam@sics.se>
  38  *
  39  */
  40
  41 #include "lwip/opt.h"
  42
  43 #include "lwip/memp.h"
  44 #include "lwip/pbuf.h"
  45 #include "lwip/udp.h"
  46 #include "lwip/raw.h"
  47 #include "lwip/tcp_impl.h"
  48 #include "lwip/igmp.h"
  49 #include "lwip/api.h"
  50 #include "lwip/api_msg.h"
  51 #include "lwip/tcpip.h"
  52 #include "lwip/sys.h"
  53 #include "lwip/timers.h"
  54 #include "lwip/stats.h"
  55 #include "netif/etharp.h"
  56 #include "lwip/ip_frag.h"
  57 #include "lwip/snmp_structs.h"
  58 #include "lwip/snmp_msg.h"
  59 #include "lwip/dns.h"
  60 #include "netif/ppp_oe.h"
  61
  62 #include <string.h>
  63
  64 #if !MEMP_MEM_MALLOC /* don't build if not configured for use in lwipopts.h */
  65
  66 struct memp {
  67   struct memp *next;
  68 #if MEMP_OVERFLOW_CHECK
  69   const char *file;
  70   int line;
  71 #endif /* MEMP_OVERFLOW_CHECK */
  72 };
  73
  74 #if MEMP_OVERFLOW_CHECK
  75 /* if MEMP_OVERFLOW_CHECK is turned on, we reserve some bytes at the beginning
  76  * and at the end of each element, initialize them as 0xcd and check
  77  * them later. */
  78 /* If MEMP_OVERFLOW_CHECK is >= 2, on every call to memp_malloc or memp_free,
  79  * every single element in each pool is checked!
  80  * This is VERY SLOW but also very helpful. */
  81 /* MEMP_SANITY_REGION_BEFORE and MEMP_SANITY_REGION_AFTER can be overridden in
  82  * lwipopts.h to change the amount reserved for checking. */
  83 #ifndef MEMP_SANITY_REGION_BEFORE
  84 #define MEMP_SANITY_REGION_BEFORE  16
  85 #endif /* MEMP_SANITY_REGION_BEFORE*/
  86 #if MEMP_SANITY_REGION_BEFORE > 0
  87 #define MEMP_SANITY_REGION_BEFORE_ALIGNED    LWIP_MEM_ALIGN_SIZE(MEMP_SANITY_REGION_BEFORE)
  88 #else
  89 #define MEMP_SANITY_REGION_BEFORE_ALIGNED    0
  90 #endif /* MEMP_SANITY_REGION_BEFORE*/
  91 #ifndef MEMP_SANITY_REGION_AFTER
  92 #define MEMP_SANITY_REGION_AFTER   16
  93 #endif /* MEMP_SANITY_REGION_AFTER*/
  94 #if MEMP_SANITY_REGION_AFTER > 0
  95 #define MEMP_SANITY_REGION_AFTER_ALIGNED     LWIP_MEM_ALIGN_SIZE(MEMP_SANITY_REGION_AFTER)
  96 #else
  97 #define MEMP_SANITY_REGION_AFTER_ALIGNED     0
  98 #endif /* MEMP_SANITY_REGION_AFTER*/
  99
 100 /* MEMP_SIZE: save space for struct memp and for sanity check */
 101 #define MEMP_SIZE          (LWIP_MEM_ALIGN_SIZE(sizeof(struct memp)) + MEMP_SANITY_REGION_BEFORE_ALIGNED)
 102 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x) + MEMP_SANITY_REGION_AFTER_ALIGNED)
 103
 104 #else /* MEMP_OVERFLOW_CHECK */
 105
 106 /* No sanity checks
 107  * We don't need to preserve the struct memp while not allocated, so we
 108  * can save a little space and set MEMP_SIZE to 0.
 109  */
 110 #define MEMP_SIZE           0
 111 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x))
 112
 113 #endif /* MEMP_OVERFLOW_CHECK */
 114
 115 /** This array holds the first free element of each pool.
 116  *  Elements form a linked list. */
 117 static struct memp *memp_tab[MEMP_MAX];
 118
 119 #else /* MEMP_MEM_MALLOC */
 120
 121 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x))
 122
 123 #endif /* MEMP_MEM_MALLOC */
 124
 125 /** This array holds the element sizes of each pool. */
 126 #if !MEM_USE_POOLS && !MEMP_MEM_MALLOC
 127 static
 128 #endif
 129 const u16_t memp_sizes[MEMP_MAX] = {
 130 #define LWIP_MEMPOOL(name,num,size,desc)  LWIP_MEM_ALIGN_SIZE(size),
 131 #include "lwip/memp_std.h"
 132 };
 133
 134 #if !MEMP_MEM_MALLOC /* don't build if not configured for use in lwipopts.h */
 135
 136 /** This array holds the number of elements in each pool. */
 137 static const u16_t memp_num[MEMP_MAX] = {
 138 #define LWIP_MEMPOOL(name,num,size,desc)  (num),
 139 #include "lwip/memp_std.h"
 140 };
 141
 142 /** This array holds a textual description of each pool. */
 143 #ifdef LWIP_DEBUG
 144 static const char *memp_desc[MEMP_MAX] = {
 145 #define LWIP_MEMPOOL(name,num,size,desc)  (desc),
 146 #include "lwip/memp_std.h"
 147 };
 148 #endif /* LWIP_DEBUG */
 149
 150 #if MEMP_SEPARATE_POOLS
 151
 152 /** This creates each memory pool. These are named memp_memory_XXX_base (where
 153  * XXX is the name of the pool defined in memp_std.h).
 154  * To relocate a pool, declare it as extern in cc.h. Example for GCC:
 155  *   extern u8_t __attribute__((section(".onchip_mem"))) memp_memory_UDP_PCB_base[];
 156  */
 157 #define LWIP_MEMPOOL(name,num,size,desc) u8_t memp_memory_ ## name ## _base \
 158   [((num) * (MEMP_SIZE + MEMP_ALIGN_SIZE(size)))];
 159 #include "lwip/memp_std.h"
 160
 161 /** This array holds the base of each memory pool. */
 162 static u8_t *const memp_bases[] = {
 163 #define LWIP_MEMPOOL(name,num,size,desc) memp_memory_ ## name ## _base,
 164 #include "lwip/memp_std.h"
 165 };
 166
 167 #else /* MEMP_SEPARATE_POOLS */
 168
 169 /** This is the actual memory used by the pools (all pools in one big block). */
 170 static u8_t memp_memory[MEM_ALIGNMENT - 1
 171 #define LWIP_MEMPOOL(name,num,size,desc) + ( (num) * (MEMP_SIZE + MEMP_ALIGN_SIZE(size) ) )
 172 #include "lwip/memp_std.h"
 173 ];
 174
 175 #endif /* MEMP_SEPARATE_POOLS */
 176
 177 #if MEMP_SANITY_CHECK
 178 /**
 179  * Check that memp-lists don't form a circle
 180  */
 181 static int
 182 memp_sanity(void)
 183 {
 184   s16_t i, c;
 185   struct memp *m, *n;
 186
 187   for (i = 0; i < MEMP_MAX; i++) {
 188     for (m = memp_tab[i]; m != NULL; m = m->next) {
 189       c = 1;
 190       for (n = memp_tab[i]; n != NULL; n = n->next) {
 191         if (n == m && --c < 0) {
 192           return 0;
 193         }
 194       }
 195     }
 196   }
 197   return 1;
 198 }
 199 #endif /* MEMP_SANITY_CHECK*/
 200 #if MEMP_OVERFLOW_CHECK
 201 #if defined(LWIP_DEBUG) && MEMP_STATS
 202 static const char * memp_overflow_names[] = {
 203 #define LWIP_MEMPOOL(name,num,size,desc) "/"desc,
 204 #include "lwip/memp_std.h"
 205   };
 206 #endif
 207
 208 /**
 209  * Check if a memp element was victim of an overflow
 210  * (e.g. the restricted area after it has been altered)
 211  *
 212  * @param p the memp element to check
 213  * @param memp_type the pool p comes from
 214  */
 215 static void
 216 memp_overflow_check_element_overflow(struct memp *p, u16_t memp_type)
 217 {
 218   u16_t k;
 219   u8_t *m;
 220 #if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
 221   m = (u8_t*)p + MEMP_SIZE + memp_sizes[memp_type];
 222   for (k = 0; k < MEMP_SANITY_REGION_AFTER_ALIGNED; k++) {
 223     if (m[k] != 0xcd) {
 224       char errstr[128] = "detected memp overflow in pool ";
 225       char digit[] = "0";
 226       if(memp_type >= 10) {
 227         digit[0] = '0' + (memp_type/10);
 228         strcat(errstr, digit);
 229       }
 230       digit[0] = '0' + (memp_type%10);
 231       strcat(errstr, digit);
 232 #if defined(LWIP_DEBUG) && MEMP_STATS
 233       strcat(errstr, memp_overflow_names[memp_type]);
 234 #endif
 235       LWIP_ASSERT(errstr, 0);
 236     }
 237   }
 238 #endif
 239 }
 240
 241 /**
 242  * Check if a memp element was victim of an underflow
 243  * (e.g. the restricted area before it has been altered)
 244  *
 245  * @param p the memp element to check
 246  * @param memp_type the pool p comes from
 247  */
 248 static void
 249 memp_overflow_check_element_underflow(struct memp *p, u16_t memp_type)
 250 {
 251   u16_t k;
 252   u8_t *m;
 253 #if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
 254   m = (u8_t*)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
 255   for (k = 0; k < MEMP_SANITY_REGION_BEFORE_ALIGNED; k++) {
 256     if (m[k] != 0xcd) {
 257       char errstr[128] = "detected memp underflow in pool ";
 258       char digit[] = "0";
 259       if(memp_type >= 10) {
 260         digit[0] = '0' + (memp_type/10);
 261         strcat(errstr, digit);
 262       }
 263       digit[0] = '0' + (memp_type%10);
 264       strcat(errstr, digit);
 265 #if defined(LWIP_DEBUG) && MEMP_STATS
 266       strcat(errstr, memp_overflow_names[memp_type]);
 267 #endif
 268       LWIP_ASSERT(errstr, 0);
 269     }
 270   }
 271 #endif
 272 }
 273
 274 /**
 275  * Do an overflow check for all elements in every pool.
 276  *
 277  * @see memp_overflow_check_element for a description of the check
 278  */
 279 static void
 280 memp_overflow_check_all(void)
 281 {
 282   u16_t i, j;
 283   struct memp *p;
 284
 285   p = (struct memp *)LWIP_MEM_ALIGN(memp_memory);
 286   for (i = 0; i < MEMP_MAX; ++i) {
 287     p = p;
 288     for (j = 0; j < memp_num[i]; ++j) {
 289       memp_overflow_check_element_overflow(p, i);
 290       p = (struct memp*)((u8_t*)p + MEMP_SIZE + memp_sizes[i] + MEMP_SANITY_REGION_AFTER_ALIGNED);
 291     }
 292   }
 293   p = (struct memp *)LWIP_MEM_ALIGN(memp_memory);
 294   for (i = 0; i < MEMP_MAX; ++i) {
 295     p = p;
 296     for (j = 0; j < memp_num[i]; ++j) {
 297       memp_overflow_check_element_underflow(p, i);
 298       p = (struct memp*)((u8_t*)p + MEMP_SIZE + memp_sizes[i] + MEMP_SANITY_REGION_AFTER_ALIGNED);
 299     }
 300   }
 301 }
 302
 303 /**
 304  * Initialize the restricted areas of all memp elements in every pool.
 305  */
 306 static void
 307 memp_overflow_init(void)
 308 {
 309   u16_t i, j;
 310   struct memp *p;
 311   u8_t *m;
 312
 313   p = (struct memp *)LWIP_MEM_ALIGN(memp_memory);
 314   for (i = 0; i < MEMP_MAX; ++i) {
 315     p = p;
 316     for (j = 0; j < memp_num[i]; ++j) {
 317 #if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
 318       m = (u8_t*)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
 319       memset(m, 0xcd, MEMP_SANITY_REGION_BEFORE_ALIGNED);
 320 #endif
 321 #if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
 322       m = (u8_t*)p + MEMP_SIZE + memp_sizes[i];
 323       memset(m, 0xcd, MEMP_SANITY_REGION_AFTER_ALIGNED);
 324 #endif
 325       p = (struct memp*)((u8_t*)p + MEMP_SIZE + memp_sizes[i] + MEMP_SANITY_REGION_AFTER_ALIGNED);
 326     }
 327   }
 328 }
 329 #endif /* MEMP_OVERFLOW_CHECK */
 330
 331 /**
 332  * Initialize this module.
 333  *
 334  * Carves out memp_memory into linked lists for each pool-type.
 335  */
 336 void
 337 memp_init(void)
 338 {
 339   struct memp *memp;
 340   u16_t i, j;
 341
 342   for (i = 0; i < MEMP_MAX; ++i) {
 343     MEMP_STATS_AVAIL(used, i, 0);
 344     MEMP_STATS_AVAIL(max, i, 0);
 345     MEMP_STATS_AVAIL(err, i, 0);
 346     MEMP_STATS_AVAIL(avail, i, memp_num[i]);
 347   }
 348
 349 #if !MEMP_SEPARATE_POOLS
 350   memp = (struct memp *)LWIP_MEM_ALIGN(memp_memory);
 351 #endif /* !MEMP_SEPARATE_POOLS */
 352   /* for every pool: */
 353   for (i = 0; i < MEMP_MAX; ++i) {
 354     memp_tab[i] = NULL;
 355 #if MEMP_SEPARATE_POOLS
 356     memp = (struct memp*)memp_bases[i];
 357 #endif /* MEMP_SEPARATE_POOLS */
 358     /* create a linked list of memp elements */
 359     for (j = 0; j < memp_num[i]; ++j) {
 360       memp->next = memp_tab[i];
 361       memp_tab[i] = memp;
 362       memp = (struct memp *)(void *)((u8_t *)memp + MEMP_SIZE + memp_sizes[i]
 363 #if MEMP_OVERFLOW_CHECK
 364         + MEMP_SANITY_REGION_AFTER_ALIGNED
 365 #endif
 366       );
 367     }
 368   }
 369 #if MEMP_OVERFLOW_CHECK
 370   memp_overflow_init();
 371   /* check everything a first time to see if it worked */
 372   memp_overflow_check_all();
 373 #endif /* MEMP_OVERFLOW_CHECK */
 374 }
 375
 376 /**
 377  * Get an element from a specific pool.
 378  *
 379  * @param type the pool to get an element from
 380  *
 381  * the debug version has two more parameters:
 382  * @param file file name calling this function
 383  * @param line number of line where this function is called
 384  *
 385  * @return a pointer to the allocated memory or a NULL pointer on error
 386  */
 387 void *
 388 #if !MEMP_OVERFLOW_CHECK
 389 memp_malloc(memp_t type)
 390 #else
 391 memp_malloc_fn(memp_t type, const char* file, const int line)
 392 #endif
 393 {
 394   struct memp *memp;
 395   SYS_ARCH_DECL_PROTECT(old_level);
 396
 397   LWIP_ERROR("memp_malloc: type < MEMP_MAX", (type < MEMP_MAX), return NULL;);
 398
 399   SYS_ARCH_PROTECT(old_level);
 400 #if MEMP_OVERFLOW_CHECK >= 2
 401   memp_overflow_check_all();
 402 #endif /* MEMP_OVERFLOW_CHECK >= 2 */
 403
 404   memp = memp_tab[type];
 405
 406   if (memp != NULL) {
 407     memp_tab[type] = memp->next;
 408 #if MEMP_OVERFLOW_CHECK
 409     memp->next = NULL;
 410     memp->file = file;
 411     memp->line = line;
 412 #endif /* MEMP_OVERFLOW_CHECK */
 413     MEMP_STATS_INC_USED(used, type);
 414     LWIP_ASSERT("memp_malloc: memp properly aligned",
 415                 ((mem_ptr_t)memp % MEM_ALIGNMENT) == 0);
 416     memp = (struct memp*)(void *)((u8_t*)memp + MEMP_SIZE);
 417   } else {
 418     LWIP_DEBUGF(MEMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("memp_malloc: out of memory in pool %s\n", memp_desc[type]));
 419     MEMP_STATS_INC(err, type);
 420   }
 421
 422   SYS_ARCH_UNPROTECT(old_level);
 423
 424   return memp;
 425 }
 426
 427 /**
 428  * Put an element back into its pool.
 429  *
 430  * @param type the pool where to put mem
 431  * @param mem the memp element to free
 432  */
 433 void
 434 memp_free(memp_t type, void *mem)
 435 {
 436   struct memp *memp;
 437   SYS_ARCH_DECL_PROTECT(old_level);
 438
 439   if (mem == NULL) {
 440     return;
 441   }
 442   LWIP_ASSERT("memp_free: mem properly aligned",
 443                 ((mem_ptr_t)mem % MEM_ALIGNMENT) == 0);
 444
 445   memp = (struct memp *)(void *)((u8_t*)mem - MEMP_SIZE);
 446
 447   SYS_ARCH_PROTECT(old_level);
 448 #if MEMP_OVERFLOW_CHECK
 449 #if MEMP_OVERFLOW_CHECK >= 2
 450   memp_overflow_check_all();
 451 #else
 452   memp_overflow_check_element_overflow(memp, type);
 453   memp_overflow_check_element_underflow(memp, type);
 454 #endif /* MEMP_OVERFLOW_CHECK >= 2 */
 455 #endif /* MEMP_OVERFLOW_CHECK */
 456
 457   MEMP_STATS_DEC(used, type);
 458
 459   memp->next = memp_tab[type];
 460   memp_tab[type] = memp;
 461
 462 #if MEMP_SANITY_CHECK
 463   LWIP_ASSERT("memp sanity", memp_sanity());
 464 #endif /* MEMP_SANITY_CHECK */
 465
 466   SYS_ARCH_UNPROTECT(old_level);
 467 }
 468
 469 #endif /* MEMP_MEM_MALLOC */