memp.c

00001 /**
00002  * @file
00003  * Dynamic pool memory manager
00004  *
00005  * lwIP has dedicated pools for many structures (netconn, protocol control blocks,
00006  * packet buffers, ...). All these pools are managed here.
00007  */
00008 
00009 /*
00010  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00011  * All rights reserved. 
00012  * 
00013  * Redistribution and use in source and binary forms, with or without modification, 
00014  * are permitted provided that the following conditions are met:
00015  *
00016  * 1. Redistributions of source code must retain the above copyright notice,
00017  *    this list of conditions and the following disclaimer.
00018  * 2. Redistributions in binary form must reproduce the above copyright notice,
00019  *    this list of conditions and the following disclaimer in the documentation
00020  *    and/or other materials provided with the distribution.
00021  * 3. The name of the author may not be used to endorse or promote products
00022  *    derived from this software without specific prior written permission. 
00023  *
00024  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
00025  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
00026  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
00027  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
00028  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
00029  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
00030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
00031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
00032  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
00033  * OF SUCH DAMAGE.
00034  *
00035  * This file is part of the lwIP TCP/IP stack.
00036  * 
00037  * Author: Adam Dunkels <adam@sics.se>
00038  *
00039  */
00040 
00041 #include "lwip/opt.h"
00042 
00043 #include "lwip/memp.h"
00044 #include "lwip/pbuf.h"
00045 #include "lwip/udp.h"
00046 #include "lwip/raw.h"
00047 #include "lwip/tcp.h"
00048 #include "lwip/igmp.h"
00049 #include "lwip/api.h"
00050 #include "lwip/api_msg.h"
00051 #include "lwip/tcpip.h"
00052 #include "lwip/sys.h"
00053 #include "lwip/stats.h"
00054 #include "netif/etharp.h"
00055 #include "lwip/ip_frag.h"
00056 
00057 #include <string.h>
00058 
00059 #if !MEMP_MEM_MALLOC /* don't build if not configured for use in lwipopts.h */
00060 
00061 struct memp {
00062   struct memp *next;
00063 #if MEMP_OVERFLOW_CHECK
00064   const char *file;
00065   int line;
00066 #endif /* MEMP_OVERFLOW_CHECK */
00067 };
00068 
00069 #if MEMP_OVERFLOW_CHECK
00070 /* if MEMP_OVERFLOW_CHECK is turned on, we reserve some bytes at the beginning
00071  * and at the end of each element, initialize them as 0xcd and check
00072  * them later. */
00073 /* If MEMP_OVERFLOW_CHECK is >= 2, on every call to memp_malloc or memp_free,
00074  * every single element in each pool is checked!
00075  * This is VERY SLOW but also very helpful. */
00076 /* MEMP_SANITY_REGION_BEFORE and MEMP_SANITY_REGION_AFTER can be overridden in
00077  * lwipopts.h to change the amount reserved for checking. */
00078 #ifndef MEMP_SANITY_REGION_BEFORE
00079 #define MEMP_SANITY_REGION_BEFORE  16
00080 #endif /* MEMP_SANITY_REGION_BEFORE*/
00081 #if MEMP_SANITY_REGION_BEFORE > 0
00082 #define MEMP_SANITY_REGION_BEFORE_ALIGNED    LWIP_MEM_ALIGN_SIZE(MEMP_SANITY_REGION_BEFORE)
00083 #else
00084 #define MEMP_SANITY_REGION_BEFORE_ALIGNED    0
00085 #endif /* MEMP_SANITY_REGION_BEFORE*/
00086 #ifndef MEMP_SANITY_REGION_AFTER
00087 #define MEMP_SANITY_REGION_AFTER   16
00088 #endif /* MEMP_SANITY_REGION_AFTER*/
00089 #if MEMP_SANITY_REGION_AFTER > 0
00090 #define MEMP_SANITY_REGION_AFTER_ALIGNED     LWIP_MEM_ALIGN_SIZE(MEMP_SANITY_REGION_AFTER)
00091 #else
00092 #define MEMP_SANITY_REGION_AFTER_ALIGNED     0
00093 #endif /* MEMP_SANITY_REGION_AFTER*/
00094 
00095 /* MEMP_SIZE: save space for struct memp and for sanity check */
00096 #define MEMP_SIZE          (LWIP_MEM_ALIGN_SIZE(sizeof(struct memp)) + MEMP_SANITY_REGION_BEFORE_ALIGNED)
00097 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x) + MEMP_SANITY_REGION_AFTER_ALIGNED)
00098 
00099 #else /* MEMP_OVERFLOW_CHECK */
00100 
00101 /* No sanity checks
00102  * We don't need to preserve the struct memp while not allocated, so we
00103  * can save a little space and set MEMP_SIZE to 0.
00104  */
00105 #define MEMP_SIZE           0
00106 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x))
00107 
00108 #endif /* MEMP_OVERFLOW_CHECK */
00109 
00110 /** This array holds the first free element of each pool.
00111  *  Elements form a linked list. */
00112 static struct memp *memp_tab[MEMP_MAX];
00113 
00114 #else /* MEMP_MEM_MALLOC */
00115 
00116 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x))
00117 
00118 #endif /* MEMP_MEM_MALLOC */
00119 
00120 /** This array holds the element sizes of each pool. */
00121 #if !MEM_USE_POOLS && !MEMP_MEM_MALLOC
00122 static
00123 #endif
00124 const u16_t memp_sizes[MEMP_MAX] = {
00125 #define LWIP_MEMPOOL(name,num,size,desc)  LWIP_MEM_ALIGN_SIZE(size),
00126 #include "lwip/memp_std.h"
00127 };
00128 
00129 #if !MEMP_MEM_MALLOC /* don't build if not configured for use in lwipopts.h */
00130 
00131 /** This array holds the number of elements in each pool. */
00132 static const u16_t memp_num[MEMP_MAX] = {
00133 #define LWIP_MEMPOOL(name,num,size,desc)  (num),
00134 #include "lwip/memp_std.h"
00135 };
00136 
00137 /** This array holds a textual description of each pool. */
00138 #ifdef LWIP_DEBUG
00139 static const char *memp_desc[MEMP_MAX] = {
00140 #define LWIP_MEMPOOL(name,num,size,desc)  (desc),
00141 #include "lwip/memp_std.h"
00142 };
00143 #endif /* LWIP_DEBUG */
00144 
00145 /** This is the actual memory used by the pools. */
00146 static u8_t memp_memory[MEM_ALIGNMENT - 1 
00147 #define LWIP_MEMPOOL(name,num,size,desc) + ( (num) * (MEMP_SIZE + MEMP_ALIGN_SIZE(size) ) )
00148 #include "lwip/memp_std.h"
00149 ];
00150 
00151 #if MEMP_SANITY_CHECK
00152 /**
00153  * Check that memp-lists don't form a circle
00154  */
00155 static int
00156 memp_sanity(void)
00157 {
00158   s16_t i, c;
00159   struct memp *m, *n;
00160 
00161   for (i = 0; i < MEMP_MAX; i++) {
00162     for (m = memp_tab[i]; m != NULL; m = m->next) {
00163       c = 1;
00164       for (n = memp_tab[i]; n != NULL; n = n->next) {
00165         if (n == m && --c < 0) {
00166           return 0;
00167         }
00168       }
00169     }
00170   }
00171   return 1;
00172 }
00173 #endif /* MEMP_SANITY_CHECK*/
00174 #if MEMP_OVERFLOW_CHECK
00175 /**
00176  * Check if a memp element was victim of an overflow
00177  * (e.g. the restricted area after it has been altered)
00178  *
00179  * @param p the memp element to check
00180  * @param memp_size the element size of the pool p comes from
00181  */
00182 static void
00183 memp_overflow_check_element(struct memp *p, u16_t memp_size)
00184 {
00185   u16_t k;
00186   u8_t *m;
00187 #if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
00188   m = (u8_t*)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
00189   for (k = 0; k < MEMP_SANITY_REGION_BEFORE_ALIGNED; k++) {
00190     if (m[k] != 0xcd) {
00191       LWIP_ASSERT("detected memp underflow!", 0);
00192     }
00193   }
00194 #endif
00195 #if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
00196   m = (u8_t*)p + MEMP_SIZE + memp_size;
00197   for (k = 0; k < MEMP_SANITY_REGION_AFTER_ALIGNED; k++) {
00198     if (m[k] != 0xcd) {
00199       LWIP_ASSERT("detected memp overflow!", 0);
00200     }
00201   }
00202 #endif
00203 }
00204 
00205 /**
00206  * Do an overflow check for all elements in every pool.
00207  *
00208  * @see memp_overflow_check_element for a description of the check
00209  */
00210 static void
00211 memp_overflow_check_all(void)
00212 {
00213   u16_t i, j;
00214   struct memp *p;
00215 
00216   p = LWIP_MEM_ALIGN(memp_memory);
00217   for (i = 0; i < MEMP_MAX; ++i) {
00218     p = p;
00219     for (j = 0; j < memp_num[i]; ++j) {
00220       memp_overflow_check_element(p, memp_sizes[i]);
00221       p = (struct memp*)((u8_t*)p + MEMP_SIZE + memp_sizes[i] + MEMP_SANITY_REGION_AFTER_ALIGNED);
00222     }
00223   }
00224 }
00225 
00226 /**
00227  * Initialize the restricted areas of all memp elements in every pool.
00228  */
00229 static void
00230 memp_overflow_init(void)
00231 {
00232   u16_t i, j;
00233   struct memp *p;
00234   u8_t *m;
00235 
00236   p = LWIP_MEM_ALIGN(memp_memory);
00237   for (i = 0; i < MEMP_MAX; ++i) {
00238     p = p;
00239     for (j = 0; j < memp_num[i]; ++j) {
00240 #if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
00241       m = (u8_t*)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
00242       memset(m, 0xcd, MEMP_SANITY_REGION_BEFORE_ALIGNED);
00243 #endif
00244 #if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
00245       m = (u8_t*)p + MEMP_SIZE + memp_sizes[i];
00246       memset(m, 0xcd, MEMP_SANITY_REGION_AFTER_ALIGNED);
00247 #endif
00248       p = (struct memp*)((u8_t*)p + MEMP_SIZE + memp_sizes[i] + MEMP_SANITY_REGION_AFTER_ALIGNED);
00249     }
00250   }
00251 }
00252 #endif /* MEMP_OVERFLOW_CHECK */
00253 
00254 /**
00255  * Initialize this module.
00256  * 
00257  * Carves out memp_memory into linked lists for each pool-type.
00258  */
00259 void
00260 memp_init(void)
00261 {
00262   struct memp *memp;
00263   u16_t i, j;
00264 
00265   for (i = 0; i < MEMP_MAX; ++i) {
00266     MEMP_STATS_AVAIL(used, i, 0);
00267     MEMP_STATS_AVAIL(max, i, 0);
00268     MEMP_STATS_AVAIL(err, i, 0);
00269     MEMP_STATS_AVAIL(avail, i, memp_num[i]);
00270   }
00271 
00272   memp = LWIP_MEM_ALIGN(memp_memory);
00273   /* for every pool: */
00274   for (i = 0; i < MEMP_MAX; ++i) {
00275     memp_tab[i] = NULL;
00276     /* create a linked list of memp elements */
00277     for (j = 0; j < memp_num[i]; ++j) {
00278       memp->next = memp_tab[i];
00279       memp_tab[i] = memp;
00280       memp = (struct memp *)((u8_t *)memp + MEMP_SIZE + memp_sizes[i]
00281 #if MEMP_OVERFLOW_CHECK
00282         + MEMP_SANITY_REGION_AFTER_ALIGNED
00283 #endif
00284       );
00285     }
00286   }
00287 #if MEMP_OVERFLOW_CHECK
00288   memp_overflow_init();
00289   /* check everything a first time to see if it worked */
00290   memp_overflow_check_all();
00291 #endif /* MEMP_OVERFLOW_CHECK */
00292 }
00293 
00294 /**
00295  * Get an element from a specific pool.
00296  *
00297  * @param type the pool to get an element from
00298  *
00299  * the debug version has two more parameters:
00300  * @param file file name calling this function
00301  * @param line number of line where this function is called
00302  *
00303  * @return a pointer to the allocated memory or a NULL pointer on error
00304  */
00305 void *
00306 #if !MEMP_OVERFLOW_CHECK
00307 memp_malloc(memp_t type)
00308 #else
00309 memp_malloc_fn(memp_t type, const char* file, const int line)
00310 #endif
00311 {
00312   struct memp *memp;
00313   SYS_ARCH_DECL_PROTECT(old_level);
00314  
00315   LWIP_ERROR("memp_malloc: type < MEMP_MAX", (type < MEMP_MAX), return NULL;);
00316 
00317   SYS_ARCH_PROTECT(old_level);
00318 #if MEMP_OVERFLOW_CHECK >= 2
00319   memp_overflow_check_all();
00320 #endif /* MEMP_OVERFLOW_CHECK >= 2 */
00321 
00322   memp = memp_tab[type];
00323   
00324   if (memp != NULL) {
00325     memp_tab[type] = memp->next;
00326 #if MEMP_OVERFLOW_CHECK
00327     memp->next = NULL;
00328     memp->file = file;
00329     memp->line = line;
00330 #endif /* MEMP_OVERFLOW_CHECK */
00331     MEMP_STATS_INC_USED(used, type);
00332     LWIP_ASSERT("memp_malloc: memp properly aligned",
00333                 ((mem_ptr_t)memp % MEM_ALIGNMENT) == 0);
00334     memp = (struct memp*)((u8_t*)memp + MEMP_SIZE);
00335   } else {
00336     LWIP_DEBUGF(MEMP_DEBUG | 2, ("memp_malloc: out of memory in pool %s\n", memp_desc[type]));
00337     MEMP_STATS_INC(err, type);
00338   }
00339 
00340   SYS_ARCH_UNPROTECT(old_level);
00341 
00342   return memp;
00343 }
00344 
00345 /**
00346  * Put an element back into its pool.
00347  *
00348  * @param type the pool where to put mem
00349  * @param mem the memp element to free
00350  */
00351 void
00352 memp_free(memp_t type, void *mem)
00353 {
00354   struct memp *memp;
00355   SYS_ARCH_DECL_PROTECT(old_level);
00356 
00357   if (mem == NULL) {
00358     return;
00359   }
00360   LWIP_ASSERT("memp_free: mem properly aligned",
00361                 ((mem_ptr_t)mem % MEM_ALIGNMENT) == 0);
00362 
00363   memp = (struct memp *)((u8_t*)mem - MEMP_SIZE);
00364 
00365   SYS_ARCH_PROTECT(old_level);
00366 #if MEMP_OVERFLOW_CHECK
00367 #if MEMP_OVERFLOW_CHECK >= 2
00368   memp_overflow_check_all();
00369 #else
00370   memp_overflow_check_element(memp, memp_sizes[type]);
00371 #endif /* MEMP_OVERFLOW_CHECK >= 2 */
00372 #endif /* MEMP_OVERFLOW_CHECK */
00373 
00374   MEMP_STATS_DEC(used, type); 
00375   
00376   memp->next = memp_tab[type]; 
00377   memp_tab[type] = memp;
00378 
00379 #if MEMP_SANITY_CHECK
00380   LWIP_ASSERT("memp sanity", memp_sanity());
00381 #endif /* MEMP_SANITY_CHECK */
00382 
00383   SYS_ARCH_UNPROTECT(old_level);
00384 }
00385 
00386 #endif /* MEMP_MEM_MALLOC */