Add a malloc/free process with garbage collector

Use it in the PPP printer.

1 files changed, 58 insertions, 0 deletions

diff --git a/netdissect-alloc.c b/netdissect-alloc.c
new file mode 100644
index 00000000..1a40b09c
--- /dev/null
+++ b/netdissect-alloc.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2018 The TCPDUMP project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that: (1) source code
+ * distributions retain the above copyright notice and this paragraph
+ * in its entirety, and (2) distributions including binary code include
+ * the above copyright notice and this paragraph in its entirety in
+ * the documentation or other materials provided with the distribution.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
+ * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
+ * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE.
+ */
+
+#include <stdlib.h>
+#include "netdissect-alloc.h"
+
+/*
+ * nd_free_all() is intended to be used after a packet printing
+ */
+
+/* Add a memory chunk in allocation linked list */
+void
+nd_add_alloc_list(netdissect_options *ndo, nd_mem_chunk_t *chunkp)
+{
+	if (ndo->ndo_last_mem_p == NULL)	/* first memory allocation */
+		chunkp->prev_mem_p = NULL;
+	else					/* previous memory allocation */
+		chunkp->prev_mem_p = ndo->ndo_last_mem_p;
+	ndo->ndo_last_mem_p = chunkp;
+}
+
+/* malloc replacement, with tracking in a linked list */
+void *
+nd_malloc(netdissect_options *ndo, size_t size)
+{
+	nd_mem_chunk_t *chunkp = malloc(sizeof(nd_mem_chunk_t) + size);
+	if (chunkp == NULL)
+		return NULL;
+	nd_add_alloc_list(ndo, chunkp);
+	return chunkp + 1;
+}
+
+/* Free chunks in allocation linked list from last to first */
+void
+nd_free_all(netdissect_options *ndo)
+{
+	nd_mem_chunk_t *current, *previous;
+	current = ndo->ndo_last_mem_p;
+	while (current != NULL) {
+		previous = current->prev_mem_p;
+		free(current);
+		current = previous;
+	}
+	ndo->ndo_last_mem_p = NULL;
+}