xref: /freebsd/contrib/tcpdump/netdissect-alloc.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
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 }
65