fix memory leak associated with compiled BPF program, sync'd from tcpdump.org. ok itojun@

4 files changed, 34 insertions, 10 deletions

diff --git a/lib/libpcap/gencode.c b/lib/libpcap/gencode.c
index 60eb842b4b9..9f494914ba1 100644
--- a/lib/libpcap/gencode.c
+++ b/lib/libpcap/gencode.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gencode.c,v 1.13 2001/06/25 23:03:32 provos Exp $	*/
+/*	$OpenBSD: gencode.c,v 1.14 2001/12/17 22:29:47 dugsong Exp $	*/
 
 /*
  * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998
@@ -22,7 +22,7 @@
  */
 #ifndef lint
 static const char rcsid[] =
-    "@(#) $Header: /home/cvs/src/lib/libpcap/gencode.c,v 1.13 2001/06/25 23:03:32 provos Exp $ (LBL)";
+    "@(#) $Header: /home/cvs/src/lib/libpcap/gencode.c,v 1.14 2001/12/17 22:29:47 dugsong Exp $ (LBL)";
 #endif
 
 #include <sys/types.h>
@@ -363,6 +363,20 @@ pcap_compile_nopcap(int snaplen_arg, int linktype_arg,
 }
 
 /*
+ * Clean up a "struct bpf_program" by freeing all the memory allocated
+ * in it.
+ */
+void
+pcap_freecode(struct bpf_program *program)
+{
+	program->bf_len = 0;
+	if (program->bf_insns != NULL) {
+		free((char *)program->bf_insns);
+		program->bf_insns = NULL;
+	}
+}
+
+/*
  * Backpatch the blocks in 'list' to 'target'.  The 'sense' field indicates
  * which of the jt and jf fields has been resolved and which is a pointer
  * back to another unresolved block (or nil).  At least one of the fields
diff --git a/lib/libpcap/pcap.3 b/lib/libpcap/pcap.3
index c2b4565c8f6..0570a9fe705 100644
--- a/lib/libpcap/pcap.3
+++ b/lib/libpcap/pcap.3
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: pcap.3,v 1.21 2001/12/06 02:50:46 millert Exp $
+.\"	$OpenBSD: pcap.3,v 1.22 2001/12/17 22:29:47 dugsong Exp $
 .\"
 .\" Copyright (c) 1994, 1996, 1997
 .\"	The Regents of the University of California.  All rights reserved.
@@ -49,6 +49,8 @@
 .Fn pcap_compile "pcap_t *p" "struct bpf_program *fp" "char *str" "int optimize" "bpf_u_int32 netmask"
 .Ft int
 .Fn pcap_setfilter "pcap_t *p" "struct bpf_program *fp"
+.Ft void
+.Fn pcap_freecode "struct bpf_program *fp"
 .Ft "u_char *"
 .Fn pcap_next "pcap_t *p" "struct pcap_pkthdr *h"
 .Ft int
@@ -251,6 +253,15 @@ is returned on failure;
 0
 is returned on success.
 .Pp
+.Fn pcap_freecode
+is used to free up allocated memory pointed to by a
+.Fa bpf_program
+struct generated by
+.Fn pcap_compile
+when that BPF program is no longer needed, for example after it has
+been made the filter program for a pcap structure by a call to
+.Fn pcap_setfilter .
+.Pp
 .Fn pcap_loop
 is similar to
 .Fn pcap_dispatch
diff --git a/lib/libpcap/pcap.c b/lib/libpcap/pcap.c
index 0fd1adb9213..6e75ef90b10 100644
--- a/lib/libpcap/pcap.c
+++ b/lib/libpcap/pcap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcap.c,v 1.6 1999/07/20 04:49:55 deraadt Exp $	*/
+/*	$OpenBSD: pcap.c,v 1.7 2001/12/17 22:29:47 dugsong Exp $	*/
 
 /*
  * Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998
@@ -35,7 +35,7 @@
 
 #ifndef lint
 static const char rcsid[] =
-    "@(#) $Header: /home/cvs/src/lib/libpcap/pcap.c,v 1.6 1999/07/20 04:49:55 deraadt Exp $ (LBL)";
+    "@(#) $Header: /home/cvs/src/lib/libpcap/pcap.c,v 1.7 2001/12/17 22:29:47 dugsong Exp $ (LBL)";
 #endif
 
 #include <sys/types.h>
@@ -202,6 +202,6 @@ pcap_close(pcap_t *p)
 	if (p->md.device != NULL)
 		free(p->md.device);
 #endif
-
+	pcap_freecode(&p->fcode);
 	free(p);
 }
diff --git a/lib/libpcap/pcap.h b/lib/libpcap/pcap.h
index 1ef558d9b5f..65aafb0cb14 100644
--- a/lib/libpcap/pcap.h
+++ b/lib/libpcap/pcap.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcap.h,v 1.9 2001/10/02 18:04:35 deraadt Exp $	*/
+/*	$OpenBSD: pcap.h,v 1.10 2001/12/17 22:29:47 dugsong Exp $	*/
 
 /*
  * Copyright (c) 1993, 1994, 1995, 1996, 1997
@@ -32,7 +32,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * @(#) $Header: /home/cvs/src/lib/libpcap/pcap.h,v 1.9 2001/10/02 18:04:35 deraadt Exp $ (LBL)
+ * @(#) $Header: /home/cvs/src/lib/libpcap/pcap.h,v 1.10 2001/12/17 22:29:47 dugsong Exp $ (LBL)
  */
 
 #ifndef lib_pcap_h
@@ -119,8 +119,7 @@ int	pcap_compile(pcap_t *, struct bpf_program *, char *, int,
 	    bpf_u_int32);
 int	pcap_compile_nopcap(int, int, struct bpf_program *,
 	    char *, int, bpf_u_int32);
-/* XXX */
-int	pcap_freecode(pcap_t *, struct bpf_program *);
+void	pcap_freecode(struct bpf_program *);
 int	pcap_datalink(pcap_t *);
 int	pcap_snapshot(pcap_t *);
 int	pcap_is_swapped(pcap_t *);