Fix a typo; this fixes bug 1854436.

[libpcap] / optimize.c

diff --git a/optimize.c b/optimize.c
index fb46ceefa922783cd8bae2ee8a4076553a445c0e..260faa21c5c9657d22c187f3a0020ca9331100b2 100644 (file)
--- a/optimize.c
+++ b/optimize.c
@@ -22,7 +22,7 @@
  */
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/optimize.c,v 1.85.2.1 2007-06-11 09:52:05 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/optimize.c,v 1.85.2.3 2007-09-12 21:29:45 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -1972,7 +1972,7 @@ opt_init(root)
         */
        unMarkAll();
        n = count_blocks(root);
-       blocks = (struct block **)malloc(n * sizeof(*blocks));
+       blocks = (struct block **)calloc(n, sizeof(*blocks));
        if (blocks == NULL)
                bpf_error("malloc");
        unMarkAll();
@@ -1980,14 +1980,14 @@ opt_init(root)
        number_blks_r(root);
 
        n_edges = 2 * n_blocks;
-       edges = (struct edge **)malloc(n_edges * sizeof(*edges));
+       edges = (struct edge **)calloc(n_edges, sizeof(*edges));
        if (edges == NULL)
                bpf_error("malloc");
 
        /*
         * The number of levels is bounded by the number of nodes.
         */
-       levels = (struct block **)malloc(n_blocks * sizeof(*levels));
+       levels = (struct block **)calloc(n_blocks, sizeof(*levels));
        if (levels == NULL)
                bpf_error("malloc");
 
@@ -2034,8 +2034,8 @@ opt_init(root)
         * we'll need.
         */
        maxval = 3 * max_stmts;
-       vmap = (struct vmapinfo *)malloc(maxval * sizeof(*vmap));
-       vnode_base = (struct valnode *)malloc(maxval * sizeof(*vnode_base));
+       vmap = (struct vmapinfo *)calloc(maxval, sizeof(*vmap));
+       vnode_base = (struct valnode *)calloc(maxval, sizeof(*vnode_base));
        if (vmap == NULL || vnode_base == NULL)
                bpf_error("malloc");
 }
@@ -2216,6 +2216,20 @@ filled:
 /*
  * Convert flowgraph intermediate representation to the
  * BPF array representation.  Set *lenp to the number of instructions.
+ *
+ * This routine does *NOT* leak the memory pointed to by fp.  It *must
+ * not* do free(fp) before returning fp; doing so would make no sense,
+ * as the BPF array pointed to by the return value of icode_to_fcode()
+ * must be valid - it's being returned for use in a bpf_program structure.
+ *
+ * If it appears that icode_to_fcode() is leaking, the problem is that
+ * the program using pcap_compile() is failing to free the memory in
+ * the BPF program when it's done - the leak is in the program, not in
+ * the routine that happens to be allocating the memory.  (By analogy, if
+ * a program calls fopen() without ever calling fclose() on the FILE *,
+ * it will leak the FILE structure; the leak is not in fopen(), it's in
+ * the program.)  Change the program to use pcap_freecode() when it's
+ * done with the filter program.  See the pcap man page.
  */
 struct bpf_insn *
 icode_to_fcode(root, lenp)