--- /dev/null
+/* lpf.c
+
+ Linux packet filter code, contributed by Brian Murrel at Interlinx
+ Support Services in Vancouver, B.C. */
+
+/*
+ * Copyright (c) 1995, 1996, 1998 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[] =
+"$Id: lpf.c,v 1.1 1998/12/22 22:34:54 mellon Exp $ Copyright (c) 1995, 1996, 1998 The Internet Software Consortium. All rights reserved.\n";
+#endif /* not lint */
+
+#include "dhcpd.h"
+#if defined (USE_LPF_SEND) || defined (USE_LPF_RECEIVE)
+#include <sys/ioctl.h>
+#include <sys/uio.h>
+
+#include <net/bpf.h>
+#include <netinet/in_systm.h>
+#include "includes/netinet/ip.h"
+#include "includes/netinet/udp.h"
+#include "includes/netinet/if_ether.h"
+
+/* Reinitializes the specified interface after an address change. This
+ is not required for packet-filter APIs. */
+
+#ifdef USE_LPF_SEND
+void if_reinitialize_send (info)
+ struct interface_info *info;
+{
+}
+#endif
+
+#ifdef USE_LPF_RECEIVE
+void if_reinitialize_receive (info)
+ struct interface_info *info;
+{
+}
+#endif
+
+/* 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. */
+
+int if_register_lpf (info)
+ struct interface_info *info;
+{
+ int sock;
+ char filename[50];
+ int b;
+ struct sockaddr sa;
+
+ /* Make an LPF socket. */
+ if ((sock = socket(PF_INET, SOCK_PACKET, htons(ETH_P_ALL))) < 0)
+ error("Open a socket for LPF: %m");
+
+ /* Bind to the interface name */
+ memset (&sa, 0, sizeof sa);
+ sa.sa_family = AF_INET;
+ strncpy (sa.sa_data, (const char *)info -> ifp, sizeof sa.sa_data);
+ if (bind (sock, &sa, sizeof sa))
+ error("Bind socket to interface: %m");
+
+ return sock;
+}
+#endif /* USE_LPF_SEND || USE_LPF_RECEIVE */
+
+#ifdef USE_LPF_SEND
+void if_register_send (info)
+ struct interface_info *info;
+{
+ /* If we're using the lpf API for sending and receiving,
+ we don't need to register this interface twice. */
+#ifndef USE_LPF_RECEIVE
+ info -> wfdesc = if_register_lpf (info, interface);
+#else
+ info -> wfdesc = info -> rfdesc;
+#endif
+ if (!quiet_interface_discovery)
+ note ("Sending on LPF/%s/%s/%s",
+ info -> name,
+ print_hw_addr (info -> hw_address.htype,
+ info -> hw_address.hlen,
+ info -> hw_address.haddr),
+ (info -> shared_network ?
+ info -> shared_network -> name : "unattached"));
+}
+#endif /* USE_LPF_SEND */
+
+#ifdef USE_LPF_RECEIVE
+/* Defined in bpf.c. We can't extern these in dhcpd.h without pulling
+ in bpf includes... */
+extern struct bpf_insn dhcp_bpf_filter [];
+extern int dhcp_bpf_filter_len;
+
+void if_register_receive (info)
+ struct interface_info *info;
+{
+ /* Open a LPF device and hang it on this interface... */
+ info -> rfdesc = if_register_lpf (info);
+
+ /* Set up the bpf filter program structure. This is defined in
+ bpf.c */
+ p.bf_len = dhcp_bpf_filter_len;
+ p.bf_insns = dhcp_bpf_filter;
+
+ /* Patch the server port into the LPF program...
+ XXX changes to filter program may require changes
+ to the insn number(s) used below! XXX */
+ dhcp_bpf_filter [8].k = ntohs (local_port);
+
+ if (setsockopt (info -> rfdesc, SOL_SOCKET, SO_ATTACH_FILTER, &p,
+ sizeof p) < 0)
+ error ("Can't install packet filter program: %m");
+ if (!quiet_interface_discovery)
+ note ("Listening on LPF/%s/%s/%s",
+ info -> name,
+ print_hw_addr (info -> hw_address.htype,
+ info -> hw_address.hlen,
+ info -> hw_address.haddr),
+ (info -> shared_network ?
+ info -> shared_network -> name : "unattached"));
+}
+#endif /* USE_LPF_RECEIVE */
+
+#ifdef USE_LPF_SEND
+ssize_t send_packet (interface, packet, raw, len, from, to, hto)
+ struct interface_info *interface;
+ struct packet *packet;
+ struct dhcp_packet *raw;
+ size_t len;
+ struct in_addr from;
+ struct sockaddr_in *to;
+ struct hardware *hto;
+{
+ int bufp = 0;
+ unsigned char buf [1500];
+
+ if (!strcmp (interface -> name, "fallback"))
+ return send_fallback (interface, packet, raw,
+ len, from, to, hto);
+
+ /* Assemble the headers... */
+ assemble_hw_header (interface, buf, &bufp, hto);
+ assemble_udp_ip_header (interface, buf, &bufp, from.s_addr,
+ to -> sin_addr.s_addr, to -> sin_port,
+ (unsigned char *)raw, len);
+ memcpy (buf + bufp, raw, len);
+ return send (interface -> wfdesc, buf, bufp + len, 0);
+}
+#endif /* USE_LPF_SEND */
+
+#ifdef USE_LPF_RECEIVE
+ssize_t receive_packet (interface, buf, len, from, hfrom)
+ struct interface_info *interface;
+ unsigned char *buf;
+ size_t len;
+ struct sockaddr_in *from;
+ struct hardware *hfrom;
+{
+ int nread;
+ int length = 0;
+ int offset = 0;
+ unsigned char ibuf [1500 + sizeof (struct enstamp)];
+ int bufix = 0;
+
+ length = read (interface -> rfdesc, ibuf, sizeof ibuf);
+ if (length <= 0)
+ return length;
+
+ bufix = sizeof (struct enstamp);
+ /* Decode the physical header... */
+ offset = decode_hw_header (interface, ibuf, bufix, hfrom);
+
+ /* If a physical layer checksum failed (dunno of any
+ physical layer that supports this, but WTH), skip this
+ packet. */
+ if (offset < 0) {
+ return 0;
+ }
+
+ bufix += offset;
+ length -= offset;
+
+ /* Decode the IP and UDP headers... */
+ offset = decode_udp_ip_header (interface, ibuf, bufix,
+ from, (unsigned char *)0, length);
+
+ /* If the IP or UDP checksum was bad, skip the packet... */
+ if (offset < 0)
+ return 0;
+
+ bufix += offset;
+ length -= offset;
+
+ /* Copy out the data in the packet... */
+ memcpy (buf, &ibuf [bufix], length);
+ return length;
+}
+
+int can_unicast_without_arp ()
+{
+ return 1;
+}
+
+void maybe_setup_fallback ()
+{
+ struct interface_info *fbi;
+ fbi = setup_fallback ();
+ if (fbi) {
+ if_register_fallback (fbi);
+ add_protocol ("fallback", fallback_interface -> wfdesc,
+ fallback_discard, fallback_interface);
+ }
+}
+#endif
projects / thirdparty / dhcp.git / commitdiff
