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_impl.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/timers.h"
00054 #include "lwip/stats.h"
00055 #include "netif/etharp.h"
00056 #include "lwip/ip_frag.h"
00057 #include "lwip/snmp_structs.h"
00058 #include "lwip/snmp_msg.h"
00059 #include "lwip/dns.h"
00060 
00061 #include <string.h>
00062 
00063 #if !MEMP_MEM_MALLOC /* don't build if not configured for use in lwipopts.h */
00064 
00065 struct memp {
00066   struct memp *next;
00067 #if MEMP_OVERFLOW_CHECK
00068   const char *file;
00069   int line;
00070 #endif /* MEMP_OVERFLOW_CHECK */
00071 };
00072 
00073 #if MEMP_OVERFLOW_CHECK
00074 /* if MEMP_OVERFLOW_CHECK is turned on, we reserve some bytes at the beginning
00075  * and at the end of each element, initialize them as 0xcd and check
00076  * them later. */
00077 /* If MEMP_OVERFLOW_CHECK is >= 2, on every call to memp_malloc or memp_free,
00078  * every single element in each pool is checked!
00079  * This is VERY SLOW but also very helpful. */
00080 /* MEMP_SANITY_REGION_BEFORE and MEMP_SANITY_REGION_AFTER can be overridden in
00081  * lwipopts.h to change the amount reserved for checking. */
00082 #ifndef MEMP_SANITY_REGION_BEFORE
00083 #define MEMP_SANITY_REGION_BEFORE  16
00084 #endif /* MEMP_SANITY_REGION_BEFORE*/
00085 #if MEMP_SANITY_REGION_BEFORE > 0
00086 #define MEMP_SANITY_REGION_BEFORE_ALIGNED    LWIP_MEM_ALIGN_SIZE(MEMP_SANITY_REGION_BEFORE)
00087 #else
00088 #define MEMP_SANITY_REGION_BEFORE_ALIGNED    0
00089 #endif /* MEMP_SANITY_REGION_BEFORE*/
00090 #ifndef MEMP_SANITY_REGION_AFTER
00091 #define MEMP_SANITY_REGION_AFTER   16
00092 #endif /* MEMP_SANITY_REGION_AFTER*/
00093 #if MEMP_SANITY_REGION_AFTER > 0
00094 #define MEMP_SANITY_REGION_AFTER_ALIGNED     LWIP_MEM_ALIGN_SIZE(MEMP_SANITY_REGION_AFTER)
00095 #else
00096 #define MEMP_SANITY_REGION_AFTER_ALIGNED     0
00097 #endif /* MEMP_SANITY_REGION_AFTER*/
00098 
00099 /* MEMP_SIZE: save space for struct memp and for sanity check */
00100 #define MEMP_SIZE          (LWIP_MEM_ALIGN_SIZE(sizeof(struct memp)) + MEMP_SANITY_REGION_BEFORE_ALIGNED)
00101 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x) + MEMP_SANITY_REGION_AFTER_ALIGNED)
00102 
00103 #else /* MEMP_OVERFLOW_CHECK */
00104 
00105 /* No sanity checks
00106  * We don't need to preserve the struct memp while not allocated, so we
00107  * can save a little space and set MEMP_SIZE to 0.
00108  */
00109 #define MEMP_SIZE           0
00110 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x))
00111 
00112 #endif /* MEMP_OVERFLOW_CHECK */
00113 
00114 /** This array holds the first free element of each pool.
00115  *  Elements form a linked list. */
00116 static struct memp *memp_tab[MEMP_MAX] MEM_POSITION;
00117 
00118 #else /* MEMP_MEM_MALLOC */
00119 
00120 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x))
00121 
00122 #endif /* MEMP_MEM_MALLOC */
00123 
00124 /** This array holds the element sizes of each pool. */
00125 #if !MEM_USE_POOLS && !MEMP_MEM_MALLOC
00126 static
00127 #endif
00128 const u16_t memp_sizes[MEMP_MAX] = {
00129 #define LWIP_MEMPOOL(name,num,size,desc)  LWIP_MEM_ALIGN_SIZE(size),
00130 #include "lwip/memp_std.h"
00131 };
00132 
00133 #if !MEMP_MEM_MALLOC /* don't build if not configured for use in lwipopts.h */
00134 
00135 /** This array holds the number of elements in each pool. */
00136 static const u16_t memp_num[MEMP_MAX] = {
00137 #define LWIP_MEMPOOL(name,num,size,desc)  (num),
00138 #include "lwip/memp_std.h"
00139 };
00140 
00141 /** This array holds a textual description of each pool. */
00142 #ifdef LWIP_DEBUG
00143 static const char *memp_desc[MEMP_MAX] = {
00144 #define LWIP_MEMPOOL(name,num,size,desc)  (desc),
00145 #include "lwip/memp_std.h"
00146 };
00147 #endif /* LWIP_DEBUG */
00148 
00149 #if MEMP_SEPARATE_POOLS
00150 
00151 /** This creates each memory pool. These are named memp_memory_XXX_base (where
00152  * XXX is the name of the pool defined in memp_std.h).
00153  * To relocate a pool, declare it as extern in cc.h. Example for GCC:
00154  *   extern u8_t __attribute__((section(".onchip_mem"))) memp_memory_UDP_PCB_base[];
00155  */
00156 #define LWIP_MEMPOOL(name,num,size,desc) u8_t memp_memory_ ## name ## _base \
00157   [((num) * (MEMP_SIZE + MEMP_ALIGN_SIZE(size)))];   
00158 #include "lwip/memp_std.h"
00159 
00160 /** This array holds the base of each memory pool. */
00161 static u8_t *const memp_bases[] = { 
00162 #define LWIP_MEMPOOL(name,num,size,desc) memp_memory_ ## name ## _base,   
00163 #include "lwip/memp_std.h"
00164 } MEM_POSITION;
00165 
00166 #else /* MEMP_SEPARATE_POOLS */
00167 
00168 /** This is the actual memory used by the pools (all pools in one big block). */
00169 static u8_t memp_memory[MEM_ALIGNMENT - 1 
00170 #define LWIP_MEMPOOL(name,num,size,desc) + ( (num) * (MEMP_SIZE + MEMP_ALIGN_SIZE(size) ) )
00171 #include "lwip/memp_std.h"
00172 ] MEM_POSITION;
00173 
00174 #endif /* MEMP_SEPARATE_POOLS */
00175 
00176 #if MEMP_SANITY_CHECK
00177 /**
00178  * Check that memp-lists don't form a circle
00179  */
00180 static int
00181 memp_sanity(void)
00182 {
00183   s16_t i, c;
00184   struct memp *m, *n;
00185 
00186   for (i = 0; i < MEMP_MAX; i++) {
00187     for (m = memp_tab[i]; m != NULL; m = m->next) {
00188       c = 1;
00189       for (n = memp_tab[i]; n != NULL; n = n->next) {
00190         if (n == m && --c < 0) {
00191           return 0;
00192         }
00193       }
00194     }
00195   }
00196   return 1;
00197 }
00198 #endif /* MEMP_SANITY_CHECK*/
00199 #if MEMP_OVERFLOW_CHECK
00200 /**
00201  * Check if a memp element was victim of an overflow
00202  * (e.g. the restricted area after it has been altered)
00203  *
00204  * @param p the memp element to check
00205  * @param memp_size the element size of the pool p comes from
00206  */
00207 static void
00208 memp_overflow_check_element(struct memp *p, u16_t memp_size)
00209 {
00210   u16_t k;
00211   u8_t *m;
00212 #if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
00213   m = (u8_t*)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
00214   for (k = 0; k < MEMP_SANITY_REGION_BEFORE_ALIGNED; k++) {
00215     if (m[k] != 0xcd) {
00216       LWIP_ASSERT("detected memp underflow!", 0);
00217     }
00218   }
00219 #endif
00220 #if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
00221   m = (u8_t*)p + MEMP_SIZE + memp_size;
00222   for (k = 0; k < MEMP_SANITY_REGION_AFTER_ALIGNED; k++) {
00223     if (m[k] != 0xcd) {
00224       LWIP_ASSERT("detected memp overflow!", 0);
00225     }
00226   }
00227 #endif
00228 }
00229 
00230 /**
00231  * Do an overflow check for all elements in every pool.
00232  *
00233  * @see memp_overflow_check_element for a description of the check
00234  */
00235 static void
00236 memp_overflow_check_all(void)
00237 {
00238   u16_t i, j;
00239   struct memp *p;
00240 
00241   p = LWIP_MEM_ALIGN(memp_memory);
00242   for (i = 0; i < MEMP_MAX; ++i) {
00243     p = p;
00244     for (j = 0; j < memp_num[i]; ++j) {
00245       memp_overflow_check_element(p, memp_sizes[i]);
00246       p = (struct memp*)((u8_t*)p + MEMP_SIZE + memp_sizes[i] + MEMP_SANITY_REGION_AFTER_ALIGNED);
00247     }
00248   }
00249 }
00250 
00251 /**
00252  * Initialize the restricted areas of all memp elements in every pool.
00253  */
00254 static void
00255 memp_overflow_init(void)
00256 {
00257   u16_t i, j;
00258   struct memp *p;
00259   u8_t *m;
00260 
00261   p = LWIP_MEM_ALIGN(memp_memory);
00262   for (i = 0; i < MEMP_MAX; ++i) {
00263     p = p;
00264     for (j = 0; j < memp_num[i]; ++j) {
00265 #if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
00266       m = (u8_t*)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
00267       memset(m, 0xcd, MEMP_SANITY_REGION_BEFORE_ALIGNED);
00268 #endif
00269 #if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
00270       m = (u8_t*)p + MEMP_SIZE + memp_sizes[i];
00271       memset(m, 0xcd, MEMP_SANITY_REGION_AFTER_ALIGNED);
00272 #endif
00273       p = (struct memp*)((u8_t*)p + MEMP_SIZE + memp_sizes[i] + MEMP_SANITY_REGION_AFTER_ALIGNED);
00274     }
00275   }
00276 }
00277 #endif /* MEMP_OVERFLOW_CHECK */
00278 
00279 /**
00280  * Initialize this module.
00281  * 
00282  * Carves out memp_memory into linked lists for each pool-type.
00283  */
00284 void
00285 memp_init(void)
00286 {
00287   struct memp *memp;
00288   u16_t i, j;
00289 
00290   for (i = 0; i < MEMP_MAX; ++i) {
00291     MEMP_STATS_AVAIL(used, i, 0);
00292     MEMP_STATS_AVAIL(max, i, 0);
00293     MEMP_STATS_AVAIL(err, i, 0);
00294     MEMP_STATS_AVAIL(avail, i, memp_num[i]);
00295   }
00296 
00297 #if !MEMP_SEPARATE_POOLS
00298   memp = (struct memp *)LWIP_MEM_ALIGN(memp_memory);
00299 #endif /* !MEMP_SEPARATE_POOLS */
00300   /* for every pool: */
00301   for (i = 0; i < MEMP_MAX; ++i) {
00302     memp_tab[i] = NULL;
00303 #if MEMP_SEPARATE_POOLS
00304     memp = (struct memp*)memp_bases[i];
00305 #endif /* MEMP_SEPARATE_POOLS */
00306     /* create a linked list of memp elements */
00307     for (j = 0; j < memp_num[i]; ++j) {
00308       memp->next = memp_tab[i];
00309       memp_tab[i] = memp;
00310       memp = (struct memp *)(void *)((u8_t *)memp + MEMP_SIZE + memp_sizes[i]
00311 #if MEMP_OVERFLOW_CHECK
00312         + MEMP_SANITY_REGION_AFTER_ALIGNED
00313 #endif
00314       );
00315     }
00316   }
00317 #if MEMP_OVERFLOW_CHECK
00318   memp_overflow_init();
00319   /* check everything a first time to see if it worked */
00320   memp_overflow_check_all();
00321 #endif /* MEMP_OVERFLOW_CHECK */
00322 }
00323 
00324 /**
00325  * Get an element from a specific pool.
00326  *
00327  * @param type the pool to get an element from
00328  *
00329  * the debug version has two more parameters:
00330  * @param file file name calling this function
00331  * @param line number of line where this function is called
00332  *
00333  * @return a pointer to the allocated memory or a NULL pointer on error
00334  */
00335 void *
00336 #if !MEMP_OVERFLOW_CHECK
00337 memp_malloc(memp_t type)
00338 #else
00339 memp_malloc_fn(memp_t type, const char* file, const int line)
00340 #endif
00341 {
00342   struct memp *memp;
00343   SYS_ARCH_DECL_PROTECT(old_level);
00344  
00345   LWIP_ERROR("memp_malloc: type < MEMP_MAX", (type < MEMP_MAX), return NULL;);
00346 
00347   SYS_ARCH_PROTECT(old_level);
00348 #if MEMP_OVERFLOW_CHECK >= 2
00349   memp_overflow_check_all();
00350 #endif /* MEMP_OVERFLOW_CHECK >= 2 */
00351 
00352   memp = memp_tab[type];
00353   
00354   if (memp != NULL) {
00355     memp_tab[type] = memp->next;
00356 #if MEMP_OVERFLOW_CHECK
00357     memp->next = NULL;
00358     memp->file = file;
00359     memp->line = line;
00360 #endif /* MEMP_OVERFLOW_CHECK */
00361     MEMP_STATS_INC_USED(used, type);
00362     LWIP_ASSERT("memp_malloc: memp properly aligned",
00363                 ((mem_ptr_t)memp % MEM_ALIGNMENT) == 0);
00364     memp = (struct memp*)(void *)((u8_t*)memp + MEMP_SIZE);
00365   } else {
00366     LWIP_DEBUGF(MEMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("memp_malloc: out of memory in pool %s\n", memp_desc[type]));
00367     MEMP_STATS_INC(err, type);
00368   }
00369 
00370   SYS_ARCH_UNPROTECT(old_level);
00371 
00372   return memp;
00373 }
00374 
00375 /**
00376  * Put an element back into its pool.
00377  *
00378  * @param type the pool where to put mem
00379  * @param mem the memp element to free
00380  */
00381 void
00382 memp_free(memp_t type, void *mem)
00383 {
00384   struct memp *memp;
00385   SYS_ARCH_DECL_PROTECT(old_level);
00386 
00387   if (mem == NULL) {
00388     return;
00389   }
00390   LWIP_ASSERT("memp_free: mem properly aligned",
00391                 ((mem_ptr_t)mem % MEM_ALIGNMENT) == 0);
00392 
00393   memp = (struct memp *)(void *)((u8_t*)mem - MEMP_SIZE);
00394 
00395   SYS_ARCH_PROTECT(old_level);
00396 #if MEMP_OVERFLOW_CHECK
00397 #if MEMP_OVERFLOW_CHECK >= 2
00398   memp_overflow_check_all();
00399 #else
00400   memp_overflow_check_element(memp, memp_sizes[type]);
00401 #endif /* MEMP_OVERFLOW_CHECK >= 2 */
00402 #endif /* MEMP_OVERFLOW_CHECK */
00403 
00404   MEMP_STATS_DEC(used, type); 
00405   
00406   memp->next = memp_tab[type]; 
00407   memp_tab[type] = memp;
00408 
00409 #if MEMP_SANITY_CHECK
00410   LWIP_ASSERT("memp sanity", memp_sanity());
00411 #endif /* MEMP_SANITY_CHECK */
00412 
00413   SYS_ARCH_UNPROTECT(old_level);
00414 }
00415 
00416 #endif /* MEMP_MEM_MALLOC */