The Tcpdump Group git mirrors - tcpdump/blob - netdissect-alloc.c

   1 /*
   2  * Copyright (c) 2018 The TCPDUMP project
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code
   7  * distributions retain the above copyright notice and this paragraph
   8  * in its entirety, and (2) distributions including binary code include
   9  * the above copyright notice and this paragraph in its entirety in
  10  * the documentation or other materials provided with the distribution.
  11  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
  12  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
  13  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  14  * FOR A PARTICULAR PURPOSE.
  15  */
  16
  17 #include <stdlib.h>
  18 #include "netdissect-alloc.h"
  19
  20 /*
  21  * nd_free_all() is intended to be used after a packet printing
  22  */
  23
  24 /* Add a memory chunk in allocation linked list */
  25 void
  26 nd_add_alloc_list(netdissect_options *ndo, nd_mem_chunk_t *chunkp)
  27 {
  28         if (ndo->ndo_last_mem_p == NULL)        /* first memory allocation */
  29                 chunkp->prev_mem_p = NULL;
  30         else                                    /* previous memory allocation */
  31                 chunkp->prev_mem_p = ndo->ndo_last_mem_p;
  32         ndo->ndo_last_mem_p = chunkp;
  33 }
  34
  35 /* malloc replacement, with tracking in a linked list */
  36 void *
  37 nd_malloc(netdissect_options *ndo, size_t size)
  38 {
  39         nd_mem_chunk_t *chunkp = malloc(sizeof(nd_mem_chunk_t) + size);
  40         if (chunkp == NULL)
  41                 return NULL;
  42         nd_add_alloc_list(ndo, chunkp);
  43         return chunkp + 1;
  44 }
  45
  46 /* Free chunks in allocation linked list from last to first */
  47 void
  48 nd_free_all(netdissect_options *ndo)
  49 {
  50         nd_mem_chunk_t *current, *previous;
  51         current = ndo->ndo_last_mem_p;
  52         while (current != NULL) {
  53                 previous = current->prev_mem_p;
  54                 free(current);
  55                 current = previous;
  56         }
  57         ndo->ndo_last_mem_p = NULL;
  58 }