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 #ifdef HAVE_CONFIG_H
  18 #include <config.h>
  19 #endif
  20
  21 #include <stdlib.h>
  22 #include "netdissect-alloc.h"
  23
  24 static void nd_add_alloc_list(netdissect_options *, nd_mem_chunk_t *);
  25
  26 /*
  27  * nd_free_all() is intended to be used after a packet printing
  28  */
  29
  30 /* Add a memory chunk in allocation linked list */
  31 static void
  32 nd_add_alloc_list(netdissect_options *ndo, nd_mem_chunk_t *chunkp)
  33 {
  34         if (ndo->ndo_last_mem_p == NULL)        /* first memory allocation */
  35                 chunkp->prev_mem_p = NULL;
  36         else                                    /* previous memory allocation */
  37                 chunkp->prev_mem_p = ndo->ndo_last_mem_p;
  38         ndo->ndo_last_mem_p = chunkp;
  39 }
  40
  41 /* malloc replacement, with tracking in a linked list */
  42 void *
  43 nd_malloc(netdissect_options *ndo, size_t size)
  44 {
  45         nd_mem_chunk_t *chunkp = malloc(sizeof(nd_mem_chunk_t) + size);
  46         if (chunkp == NULL)
  47                 return NULL;
  48         nd_add_alloc_list(ndo, chunkp);
  49         return chunkp + 1;
  50 }
  51
  52 /* Free chunks in allocation linked list from last to first */
  53 void
  54 nd_free_all(netdissect_options *ndo)
  55 {
  56         nd_mem_chunk_t *current, *previous;
  57         current = ndo->ndo_last_mem_p;
  58         while (current != NULL) {
  59                 previous = current->prev_mem_p;
  60                 free(current);
  61                 current = previous;
  62         }
  63         ndo->ndo_last_mem_p = NULL;
  64 }