Berkeley Packet Filter support

1 files changed, 91 insertions, 0 deletions

diff --git a/common/bpf.c b/common/bpf.c
new file mode 100644
index 00000000..87ff51b5
--- /dev/null
+++ b/common/bpf.c
@@ -0,0 +1,91 @@
+/* bpf.c
+
+   BPF socket interface code, originally contributed by Archie Cobbs. */
+
+/*
+ * Copyright (c) 1995, 1996 The Internet Software Consortium.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#ifndef lint
+static char copyright[] =
+"@(#) Copyright (c) 1995 The Internet Software Consortium.  All rights reserved.\n";
+#endif /* not lint */
+
+#include "dhcpd.h"
+#include <sys/ioctl.h>
+
+#include <net/bpf.h>
+#include <net/if.h>
+#include <net/if_arp.h>
+#include <net/if_dl.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netinet/udp.h>
+#include <netinet/if_ether.h>
+
+/* Called by get_interface_list for each interface that's discovered.
+   Opens a packet filter for each interface and adds it to the select
+   mask. */
+
+void if_register (info, ifp)
+	struct interface_info *addr;
+	struct ifreq *ifp;
+{
+	int b;
+	char filename[50];
+	struct sockaddr_in sock;
+
+	/* Open a BPF device */
+	for (b = 0; 1; b++) {
+		snprintf(filename, sizeof(filename), "/dev/bpf%d", b);
+		info -> wfdesc = .bpf = open(filename, O_RDWR, 0);
+		if (info -> rfdesc < 0) {
+			if (errno == EBUSY) {
+				continue;
+			} else {
+				error ("Can't find free bpf: %m");
+			}
+		} else {
+			break;
+		}
+	}
+
+	/* Set the BPF device to point at this interface. */
+	if (ioctl(info -> rfdesc, BIOCSETIF, ifp) < 0)
+		error ("Can't BIOCSETIF on bpf: %m");
+}
+