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 #include "netif/ppp_oe.h"
00061 
00062 #include <string.h>
00063 
00064 #if !MEMP_MEM_MALLOC /* don't build if not configured for use in lwipopts.h */
00065 
00066 struct memp {
00067   struct memp *next;
00068 #if MEMP_OVERFLOW_CHECK
00069   const char *file;
00070   int line;
00071 #endif /* MEMP_OVERFLOW_CHECK */
00072 };
00073 
00074 #if MEMP_OVERFLOW_CHECK
00075 /* if MEMP_OVERFLOW_CHECK is turned on, we reserve some bytes at the beginning
00076  * and at the end of each element, initialize them as 0xcd and check
00077  * them later. */
00078 /* If MEMP_OVERFLOW_CHECK is >= 2, on every call to memp_malloc or memp_free,
00079  * every single element in each pool is checked!
00080  * This is VERY SLOW but also very helpful. */
00081 /* MEMP_SANITY_REGION_BEFORE and MEMP_SANITY_REGION_AFTER can be overridden in
00082  * lwipopts.h to change the amount reserved for checking. */
00083 #ifndef MEMP_SANITY_REGION_BEFORE
00084 #define MEMP_SANITY_REGION_BEFORE  16
00085 #endif /* MEMP_SANITY_REGION_BEFORE*/
00086 #if MEMP_SANITY_REGION_BEFORE > 0
00087 #define MEMP_SANITY_REGION_BEFORE_ALIGNED    LWIP_MEM_ALIGN_SIZE(MEMP_SANITY_REGION_BEFORE)
00088 #else
00089 #define MEMP_SANITY_REGION_BEFORE_ALIGNED    0
00090 #endif /* MEMP_SANITY_REGION_BEFORE*/
00091 #ifndef MEMP_SANITY_REGION_AFTER
00092 #define MEMP_SANITY_REGION_AFTER   16
00093 #endif /* MEMP_SANITY_REGION_AFTER*/
00094 #if MEMP_SANITY_REGION_AFTER > 0
00095 #define MEMP_SANITY_REGION_AFTER_ALIGNED     LWIP_MEM_ALIGN_SIZE(MEMP_SANITY_REGION_AFTER)
00096 #else
00097 #define MEMP_SANITY_REGION_AFTER_ALIGNED     0
00098 #endif /* MEMP_SANITY_REGION_AFTER*/
00099 
00100 /* MEMP_SIZE: save space for struct memp and for sanity check */
00101 #define MEMP_SIZE          (LWIP_MEM_ALIGN_SIZE(sizeof(struct memp)) + MEMP_SANITY_REGION_BEFORE_ALIGNED)
00102 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x) + MEMP_SANITY_REGION_AFTER_ALIGNED)
00103 
00104 #else /* MEMP_OVERFLOW_CHECK */
00105 
00106 /* No sanity checks
00107  * We don't need to preserve the struct memp while not allocated, so we
00108  * can save a little space and set MEMP_SIZE to 0.
00109  */
00110 #define MEMP_SIZE           0
00111 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x))
00112 
00113 #endif /* MEMP_OVERFLOW_CHECK */
00114 
00115 /** This array holds the first free element of each pool.
00116  *  Elements form a linked list. */
00117 static struct memp *memp_tab[MEMP_MAX];
00118 
00119 #else /* MEMP_MEM_MALLOC */
00120 
00121 #define MEMP_ALIGN_SIZE(x) (LWIP_MEM_ALIGN_SIZE(x))
00122 
00123 #endif /* MEMP_MEM_MALLOC */
00124 
00125 /** This array holds the element sizes of each pool. */
00126 #if !MEM_USE_POOLS && !MEMP_MEM_MALLOC
00127 static
00128 #endif
00129 const u16_t memp_sizes[MEMP_MAX] = {
00130 #define LWIP_MEMPOOL(name,num,size,desc)  LWIP_MEM_ALIGN_SIZE(size),
00131 #include "lwip/memp_std.h"
00132 };
00133 
00134 #if !MEMP_MEM_MALLOC /* don't build if not configured for use in lwipopts.h */
00135 
00136 /** This array holds the number of elements in each pool. */
00137 static const u16_t memp_num[MEMP_MAX] = {
00138 #define LWIP_MEMPOOL(name,num,size,desc)  (num),
00139 #include "lwip/memp_std.h"
00140 };
00141 
00142 /** This array holds a textual description of each pool. */
00143 #ifdef LWIP_DEBUG
00144 static const char *memp_desc[MEMP_MAX] = {
00145 #define LWIP_MEMPOOL(name,num,size,desc)  (desc),
00146 #include "lwip/memp_std.h"
00147 };
00148 #endif /* LWIP_DEBUG */
00149 
00150 #if MEMP_SEPARATE_POOLS
00151 
00152 /** This creates each memory pool. These are named memp_memory_XXX_base (where
00153  * XXX is the name of the pool defined in memp_std.h).
00154  * To relocate a pool, declare it as extern in cc.h. Example for GCC:
00155  *   extern u8_t __attribute__((section(".onchip_mem"))) memp_memory_UDP_PCB_base[];
00156  */
00157 #define LWIP_MEMPOOL(name,num,size,desc) u8_t memp_memory_ ## name ## _base \
00158   [((num) * (MEMP_SIZE + MEMP_ALIGN_SIZE(size)))];   
00159 #include "lwip/memp_std.h"
00160 
00161 /** This array holds the base of each memory pool. */
00162 static u8_t *const memp_bases[] = { 
00163 #define LWIP_MEMPOOL(name,num,size,desc) memp_memory_ ## name ## _base,   
00164 #include "lwip/memp_std.h"
00165 };
00166 
00167 #else /* MEMP_SEPARATE_POOLS */
00168 
00169 /** This is the actual memory used by the pools (all pools in one big block). */
00170 static u8_t memp_memory[MEM_ALIGNMENT - 1 
00171 #define LWIP_MEMPOOL(name,num,size,desc) + ( (num) * (MEMP_SIZE + MEMP_ALIGN_SIZE(size) ) )
00172 #include "lwip/memp_std.h"
00173 ];
00174 
00175 #endif /* MEMP_SEPARATE_POOLS */
00176 
00177 #if MEMP_SANITY_CHECK
00178 /**
00179  * Check that memp-lists don't form a circle, using "Floyd's cycle-finding algorithm".
00180  */
00181 static int
00182 memp_sanity(void)
00183 {
00184   s16_t i;
00185   struct memp *t, *h;
00186 
00187   for (i = 0; i < MEMP_MAX; i++) {
00188     t = memp_tab[i];
00189     if(t != NULL) {
00190       for (h = t->next; (t != NULL) && (h != NULL); t = t->next,
00191         h = (((h->next != NULL) && (h->next->next != NULL)) ? h->next->next : NULL)) {
00192         if (t == h) {
00193           return 0;
00194         }
00195       }
00196     }
00197   }
00198   return 1;
00199 }
00200 #endif /* MEMP_SANITY_CHECK*/
00201 #if MEMP_OVERFLOW_CHECK
00202 #if defined(LWIP_DEBUG) && MEMP_STATS
00203 static const char * memp_overflow_names[] = {
00204 #define LWIP_MEMPOOL(name,num,size,desc) "/"desc,
00205 #include "lwip/memp_std.h"
00206   };
00207 #endif
00208 
00209 /**
00210  * Check if a memp element was victim of an overflow
00211  * (e.g. the restricted area after it has been altered)
00212  *
00213  * @param p the memp element to check
00214  * @param memp_type the pool p comes from
00215  */
00216 static void
00217 memp_overflow_check_element_overflow(struct memp *p, u16_t memp_type)
00218 {
00219   u16_t k;
00220   u8_t *m;
00221 #if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
00222   m = (u8_t*)p + MEMP_SIZE + memp_sizes[memp_type];
00223   for (k = 0; k < MEMP_SANITY_REGION_AFTER_ALIGNED; k++) {
00224     if (m[k] != 0xcd) {
00225       char errstr[128] = "detected memp overflow in pool ";
00226       char digit[] = "0";
00227       if(memp_type >= 10) {
00228         digit[0] = '0' + (memp_type/10);
00229         strcat(errstr, digit);
00230       }
00231       digit[0] = '0' + (memp_type%10);
00232       strcat(errstr, digit);
00233 #if defined(LWIP_DEBUG) && MEMP_STATS
00234       strcat(errstr, memp_overflow_names[memp_type]);
00235 #endif
00236       LWIP_ASSERT(errstr, 0);
00237     }
00238   }
00239 #endif
00240 }
00241 
00242 /**
00243  * Check if a memp element was victim of an underflow
00244  * (e.g. the restricted area before it has been altered)
00245  *
00246  * @param p the memp element to check
00247  * @param memp_type the pool p comes from
00248  */
00249 static void
00250 memp_overflow_check_element_underflow(struct memp *p, u16_t memp_type)
00251 {
00252   u16_t k;
00253   u8_t *m;
00254 #if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
00255   m = (u8_t*)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
00256   for (k = 0; k < MEMP_SANITY_REGION_BEFORE_ALIGNED; k++) {
00257     if (m[k] != 0xcd) {
00258       char errstr[128] = "detected memp underflow in pool ";
00259       char digit[] = "0";
00260       if(memp_type >= 10) {
00261         digit[0] = '0' + (memp_type/10);
00262         strcat(errstr, digit);
00263       }
00264       digit[0] = '0' + (memp_type%10);
00265       strcat(errstr, digit);
00266 #if defined(LWIP_DEBUG) && MEMP_STATS
00267       strcat(errstr, memp_overflow_names[memp_type]);
00268 #endif
00269       LWIP_ASSERT(errstr, 0);
00270     }
00271   }
00272 #endif
00273 }
00274 
00275 /**
00276  * Do an overflow check for all elements in every pool.
00277  *
00278  * @see memp_overflow_check_element for a description of the check
00279  */
00280 static void
00281 memp_overflow_check_all(void)
00282 {
00283   u16_t i, j;
00284   struct memp *p;
00285 
00286   p = (struct memp *)LWIP_MEM_ALIGN(memp_memory);
00287   for (i = 0; i < MEMP_MAX; ++i) {
00288     p = p;
00289     for (j = 0; j < memp_num[i]; ++j) {
00290       memp_overflow_check_element_overflow(p, i);
00291       p = (struct memp*)((u8_t*)p + MEMP_SIZE + memp_sizes[i] + MEMP_SANITY_REGION_AFTER_ALIGNED);
00292     }
00293   }
00294   p = (struct memp *)LWIP_MEM_ALIGN(memp_memory);
00295   for (i = 0; i < MEMP_MAX; ++i) {
00296     p = p;
00297     for (j = 0; j < memp_num[i]; ++j) {
00298       memp_overflow_check_element_underflow(p, i);
00299       p = (struct memp*)((u8_t*)p + MEMP_SIZE + memp_sizes[i] + MEMP_SANITY_REGION_AFTER_ALIGNED);
00300     }
00301   }
00302 }
00303 
00304 /**
00305  * Initialize the restricted areas of all memp elements in every pool.
00306  */
00307 static void
00308 memp_overflow_init(void)
00309 {
00310   u16_t i, j;
00311   struct memp *p;
00312   u8_t *m;
00313 
00314   p = (struct memp *)LWIP_MEM_ALIGN(memp_memory);
00315   for (i = 0; i < MEMP_MAX; ++i) {
00316     p = p;
00317     for (j = 0; j < memp_num[i]; ++j) {
00318 #if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
00319       m = (u8_t*)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
00320       memset(m, 0xcd, MEMP_SANITY_REGION_BEFORE_ALIGNED);
00321 #endif
00322 #if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
00323       m = (u8_t*)p + MEMP_SIZE + memp_sizes[i];
00324       memset(m, 0xcd, MEMP_SANITY_REGION_AFTER_ALIGNED);
00325 #endif
00326       p = (struct memp*)((u8_t*)p + MEMP_SIZE + memp_sizes[i] + MEMP_SANITY_REGION_AFTER_ALIGNED);
00327     }
00328   }
00329 }
00330 #endif /* MEMP_OVERFLOW_CHECK */
00331 
00332 /**
00333  * Initialize this module.
00334  * 
00335  * Carves out memp_memory into linked lists for each pool-type.
00336  */
00337 void
00338 memp_init(void)
00339 {
00340   struct memp *memp;
00341   u16_t i, j;
00342 
00343   for (i = 0; i < MEMP_MAX; ++i) {
00344     MEMP_STATS_AVAIL(used, i, 0);
00345     MEMP_STATS_AVAIL(max, i, 0);
00346     MEMP_STATS_AVAIL(err, i, 0);
00347     MEMP_STATS_AVAIL(avail, i, memp_num[i]);
00348   }
00349 
00350 #if !MEMP_SEPARATE_POOLS
00351   memp = (struct memp *)LWIP_MEM_ALIGN(memp_memory);
00352 #endif /* !MEMP_SEPARATE_POOLS */
00353   /* for every pool: */
00354   for (i = 0; i < MEMP_MAX; ++i) {
00355     memp_tab[i] = NULL;
00356 #if MEMP_SEPARATE_POOLS
00357     memp = (struct memp*)memp_bases[i];
00358 #endif /* MEMP_SEPARATE_POOLS */
00359     /* create a linked list of memp elements */
00360     for (j = 0; j < memp_num[i]; ++j) {
00361       memp->next = memp_tab[i];
00362       memp_tab[i] = memp;
00363       memp = (struct memp *)(void *)((u8_t *)memp + MEMP_SIZE + memp_sizes[i]
00364 #if MEMP_OVERFLOW_CHECK
00365         + MEMP_SANITY_REGION_AFTER_ALIGNED
00366 #endif
00367       );
00368     }
00369   }
00370 #if MEMP_OVERFLOW_CHECK
00371   memp_overflow_init();
00372   /* check everything a first time to see if it worked */
00373   memp_overflow_check_all();
00374 #endif /* MEMP_OVERFLOW_CHECK */
00375 }
00376 
00377 /**
00378  * Get an element from a specific pool.
00379  *
00380  * @param type the pool to get an element from
00381  *
00382  * the debug version has two more parameters:
00383  * @param file file name calling this function
00384  * @param line number of line where this function is called
00385  *
00386  * @return a pointer to the allocated memory or a NULL pointer on error
00387  */
00388 void *
00389 #if !MEMP_OVERFLOW_CHECK
00390 memp_malloc(memp_t type)
00391 #else
00392 memp_malloc_fn(memp_t type, const char* file, const int line)
00393 #endif
00394 {
00395   struct memp *memp;
00396   SYS_ARCH_DECL_PROTECT(old_level);
00397  
00398   LWIP_ERROR("memp_malloc: type < MEMP_MAX", (type < MEMP_MAX), return NULL;);
00399 
00400   SYS_ARCH_PROTECT(old_level);
00401 #if MEMP_OVERFLOW_CHECK >= 2
00402   memp_overflow_check_all();
00403 #endif /* MEMP_OVERFLOW_CHECK >= 2 */
00404 
00405   memp = memp_tab[type];
00406   
00407   if (memp != NULL) {
00408     memp_tab[type] = memp->next;
00409 #if MEMP_OVERFLOW_CHECK
00410     memp->next = NULL;
00411     memp->file = file;
00412     memp->line = line;
00413 #endif /* MEMP_OVERFLOW_CHECK */
00414     MEMP_STATS_INC_USED(used, type);
00415     LWIP_ASSERT("memp_malloc: memp properly aligned",
00416                 ((mem_ptr_t)memp % MEM_ALIGNMENT) == 0);
00417     memp = (struct memp*)(void *)((u8_t*)memp + MEMP_SIZE);
00418   } else {
00419     LWIP_DEBUGF(MEMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("memp_malloc: out of memory in pool %s\n", memp_desc[type]));
00420     MEMP_STATS_INC(err, type);
00421   }
00422 
00423   SYS_ARCH_UNPROTECT(old_level);
00424 
00425   return memp;
00426 }
00427 
00428 /**
00429  * Put an element back into its pool.
00430  *
00431  * @param type the pool where to put mem
00432  * @param mem the memp element to free
00433  */
00434 void
00435 memp_free(memp_t type, void *mem)
00436 {
00437   struct memp *memp;
00438   SYS_ARCH_DECL_PROTECT(old_level);
00439 
00440   if (mem == NULL) {
00441     return;
00442   }
00443   LWIP_ASSERT("memp_free: mem properly aligned",
00444                 ((mem_ptr_t)mem % MEM_ALIGNMENT) == 0);
00445 
00446   memp = (struct memp *)(void *)((u8_t*)mem - MEMP_SIZE);
00447 
00448   SYS_ARCH_PROTECT(old_level);
00449 #if MEMP_OVERFLOW_CHECK
00450 #if MEMP_OVERFLOW_CHECK >= 2
00451   memp_overflow_check_all();
00452 #else
00453   memp_overflow_check_element_overflow(memp, type);
00454   memp_overflow_check_element_underflow(memp, type);
00455 #endif /* MEMP_OVERFLOW_CHECK >= 2 */
00456 #endif /* MEMP_OVERFLOW_CHECK */
00457 
00458   MEMP_STATS_DEC(used, type); 
00459   
00460   memp->next = memp_tab[type]; 
00461   memp_tab[type] = memp;
00462 
00463 #if MEMP_SANITY_CHECK
00464   LWIP_ASSERT("memp sanity", memp_sanity());
00465 #endif /* MEMP_SANITY_CHECK */
00466 
00467   SYS_ARCH_UNPROTECT(old_level);
00468 }
00469 
00470 #endif /* MEMP_MEM_MALLOC */