Now that WinPcap is a DLL, I can load it at run-time rather than load-time.

That means that I no longer need to distribute capture and non-capture
versions of Ethereal for Win32; one version (compiled with WinPcap headers)
can run on systems with or without WinPcap.

For systems that don't have WinPcap, instead of disabling the Capture
menu, Capture|Start brings up a dialogue informing the user that wpcap.dll
was not loadable, and gives a URL to the WinPcap home page.

svn path=/trunk/; revision=3249

1 files changed, 205 insertions, 0 deletions

diff --git a/capture-wpcap.c b/capture-wpcap.c
new file mode 100644
index 0000000000..843a63fc4c
--- /dev/null
+++ b/capture-wpcap.c
@@ -0,0 +1,205 @@
+/* capture-wpcap.c
+ * Try to load WinPcap DLL at run-time.
+ *
+ * $Id: capture-wpcap.c,v 1.1 2001/04/03 05:26:26 gram Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@zing.org>
+ * Copyright 2001 Gerald Combs
+ *
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <glib.h>
+#include <gmodule.h>
+
+#ifdef HAVE_LIBPCAP
+#include <pcap.h>
+#endif
+
+/* XXX - yes, I know, I should move cppmagic.h to a generic location. */
+#include "tools/lemon/cppmagic.h"
+
+gboolean has_wpcap = FALSE;
+
+#ifdef HAVE_LIBPCAP
+
+
+static char*   (*p_pcap_lookupdev) (char *);
+static void    (*p_pcap_close) (pcap_t *);
+static int     (*p_pcap_stats) (pcap_t *, struct pcap_stat *);
+static int     (*p_pcap_dispatch) (pcap_t *, int, pcap_handler, u_char *);
+static int     (*p_pcap_snapshot) (pcap_t *);
+static int     (*p_pcap_datalink) (pcap_t *);
+static int     (*p_pcap_setfilter) (pcap_t *, struct bpf_program *);
+static char*   (*p_pcap_geterr) (pcap_t *);
+static int     (*p_pcap_compile) (pcap_t *, struct bpf_program *, char *, int,
+			bpf_u_int32);
+static int     (*p_pcap_lookupnet) (char *, bpf_u_int32 *, bpf_u_int32 *,
+			char *);
+static pcap_t* (*p_pcap_open_live) (char *, int, int, int, char *);
+static int     (*p_pcap_loop) (pcap_t *, int, pcap_handler, u_char *);
+
+typedef struct {
+	const char	*name;
+	gpointer	*ptr;
+} symbol_table_t;
+
+#define SYM(x)	STRINGIFY(x) , (gpointer) &CONCAT(p_,x)
+
+void
+load_wpcap(void)
+{
+
+	/* These are the symbols I need from Wpcap */
+	symbol_table_t	symbols[] = {
+		SYM(pcap_lookupdev),
+		SYM(pcap_close),
+		SYM(pcap_stats),
+		SYM(pcap_dispatch),
+		SYM(pcap_snapshot),
+		SYM(pcap_datalink),
+		SYM(pcap_setfilter),
+		SYM(pcap_geterr),
+		SYM(pcap_compile),
+		SYM(pcap_lookupnet),
+		SYM(pcap_open_live),
+		SYM(pcap_loop),
+		NULL, NULL
+	};
+
+	GModule		*wh; /* wpcap handle */
+	symbol_table_t	*sym;
+
+	wh = g_module_open("wpcap", 0);
+
+	if (!wh) {
+		return;
+	}
+
+	sym = symbols;
+	while (sym && sym->name) {
+		if (!g_module_symbol(wh, sym->name, sym->ptr)) {
+			return;
+		}
+		sym++;
+	}
+
+
+	has_wpcap = TRUE;
+}
+
+char*
+pcap_lookupdev (char *a)
+{
+	g_assert(has_wpcap);
+	return p_pcap_lookupdev(a);
+}
+
+void
+pcap_close(pcap_t *a)
+{
+	g_assert(has_wpcap);
+	p_pcap_close(a);
+}
+
+int
+pcap_stats(pcap_t *a, struct pcap_stat *b)
+{
+	g_assert(has_wpcap);
+	return p_pcap_stats(a, b);
+}
+
+int
+pcap_dispatch(pcap_t *a, int b, pcap_handler c, u_char *d)
+{
+	g_assert(has_wpcap);
+	return p_pcap_dispatch(a, b, c, d);
+}
+
+
+int
+pcap_snapshot(pcap_t *a)
+{
+	g_assert(has_wpcap);
+	return p_pcap_snapshot(a);
+}
+
+
+int
+pcap_datalink(pcap_t *a)
+{
+	g_assert(has_wpcap);
+	return p_pcap_datalink(a);
+}
+
+int
+pcap_setfilter(pcap_t *a, struct bpf_program *b)
+{
+	g_assert(has_wpcap);
+	return p_pcap_setfilter(a, b);
+}
+
+char*
+pcap_geterr(pcap_t *a)
+{
+	g_assert(has_wpcap);
+	return p_pcap_geterr(a);
+}
+
+int
+pcap_compile(pcap_t *a, struct bpf_program *b, char *c, int d,
+            bpf_u_int32 e)
+{
+	g_assert(has_wpcap);
+	return p_pcap_compile(a, b, c, d, e);
+}
+
+int
+pcap_lookupnet(char *a, bpf_u_int32 *b, bpf_u_int32 *c, char *d)
+{
+	g_assert(has_wpcap);
+	return p_pcap_lookupnet(a, b, c, d);
+}
+
+pcap_t*
+pcap_open_live(char *a, int b, int c, int d, char *e)
+{
+	g_assert(has_wpcap);
+	return p_pcap_open_live(a, b, c, d, e);
+}
+
+int
+pcap_loop(pcap_t *a, int b, pcap_handler c, u_char *d)
+{
+	g_assert(has_wpcap);
+	return p_pcap_loop(a, b, c, d);
+}
+
+#else /* HAVE_LIBPCAP */
+
+void
+load_wpcap(void)
+{
+	return;
+}
+
+
+#endif /* HAVE_LIBPCAP */