299 lines
8.9 KiB
C
299 lines
8.9 KiB
C
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/* upf.c
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Ultrix PacketFilter interface code.
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/*
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* Copyright (c) 1995, 1996, 1997 The Internet Software Consortium.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of The Internet Software Consortium nor the names
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* of its contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
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* CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* This software has been written for the Internet Software Consortium
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* by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
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* Enterprises. To learn more about the Internet Software Consortium,
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* see ``http://www.vix.com/isc''. To learn more about Vixie
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* Enterprises, see ``http://www.vix.com''.
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*/
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#ifndef lint
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static char copyright[] =
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"$Id: upf.c,v 1.3 1997/10/20 21:47:15 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium. All rights reserved.\n";
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#endif /* not lint */
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#include "dhcpd.h"
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#if defined (USE_UPF_SEND) || defined (USE_UPF_RECEIVE)
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#include <sys/ioctl.h>
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#include <sys/uio.h>
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#include <net/pfilt.h>
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#include <netinet/in_systm.h>
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#include "includes/netinet/ip.h"
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#include "includes/netinet/udp.h"
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#include "includes/netinet/if_ether.h"
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/* Reinitializes the specified interface after an address change. This
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is not required for packet-filter APIs. */
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#ifdef USE_UPF_SEND
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void if_reinitialize_send (info)
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struct interface_info *info;
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{
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}
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#endif
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#ifdef USE_UPF_RECEIVE
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void if_reinitialize_receive (info)
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struct interface_info *info;
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{
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}
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#endif
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/* Called by get_interface_list for each interface that's discovered.
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Opens a packet filter for each interface and adds it to the select
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mask. */
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int if_register_upf (info)
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struct interface_info *info;
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{
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int sock;
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char filename[50];
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int b;
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struct endevp param;
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/* Open a UPF device */
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for (b = 0; 1; b++) {
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#ifndef NO_SNPRINTF
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snprintf(filename, sizeof(filename), "/dev/pf/pfilt%d", b);
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#else
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sprintf(filename, "/dev/pf/pfilt%d", b);
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#endif
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sock = open (filename, O_RDWR, 0);
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if (sock < 0) {
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if (errno == EBUSY) {
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continue;
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} else {
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error ("Can't find free upf: %m");
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}
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} else {
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break;
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}
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}
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/* Set the UPF device to point at this interface. */
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if (ioctl (sock, EIOCSETIF, info -> ifp) < 0)
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error ("Can't attach interface %s to upf device %s: %m",
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info -> name, filename);
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/* Get the hardware address. */
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if (ioctl (sock, EIOCDEVP, ¶m) < 0)
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error ("Can't get interface %s hardware address: %m",
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info -> name);
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/* We only know how to do ethernet. */
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if (param.end_dev_type != ENDT_10MB)
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error ("Invalid device type on network interface %s: %d",
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info -> name, param.end_dev_type);
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if (param.end_addr_len != 6)
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error ("Invalid hardware address length on %s: %d",
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info -> name, param.end_addr_len);
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info -> hw_address.hlen = 6;
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info -> hw_address.htype = ARPHRD_ETHER;
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memcpy (&info -> hw_address.haddr [0], param.end_addr, 6);
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return sock;
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}
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#endif /* USE_UPF_SEND || USE_UPF_RECEIVE */
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#ifdef USE_UPF_SEND
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void if_register_send (info)
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struct interface_info *info;
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{
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/* If we're using the upf API for sending and receiving,
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we don't need to register this interface twice. */
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#ifndef USE_UPF_RECEIVE
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info -> wfdesc = if_register_upf (info, interface);
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#else
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info -> wfdesc = info -> rfdesc;
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#endif
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if (!quiet_interface_discovery)
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note ("Sending on UPF/%s/%s/%s",
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info -> name,
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print_hw_addr (info -> hw_address.htype,
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info -> hw_address.hlen,
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info -> hw_address.haddr),
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(info -> shared_network ?
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info -> shared_network -> name : "unattached"));
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}
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#endif /* USE_UPF_SEND */
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#ifdef USE_UPF_RECEIVE
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/* Packet filter program...
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XXX Changes to the filter program may require changes to the constant
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offsets used in if_register_send to patch the UPF program! XXX */
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void if_register_receive (info)
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struct interface_info *info;
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{
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int flag = 1;
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u_int32_t addr;
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struct enfilter pf;
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u_int32_t bits;
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/* Open a UPF device and hang it on this interface... */
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info -> rfdesc = if_register_upf (info);
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/* Allow the copyall flag to be set... */
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if (ioctl(info -> rfdesc, EIOCALLOWCOPYALL, &flag) < 0)
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error ("Can't set ALLOWCOPYALL: %m");
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/* Clear all the packet filter mode bits first... */
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flag = (ENHOLDSIG | ENBATCH | ENTSTAMP | ENPROMISC |
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ENNONEXCL | ENCOPYALL);
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if (ioctl (info -> rfdesc, EIOCMBIC, &flag) < 0)
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error ("Can't clear pfilt bits: %m");
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/* Set the ENBATCH and ENCOPYALL bits... */
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bits = ENBATCH | ENCOPYALL;
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if (ioctl (info -> rfdesc, EIOCMBIS, &bits) < 0)
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error ("Can't set ENBATCH|ENCOPYALL: %m");
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/* Set up the UPF filter program. */
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/* XXX Unlike the BPF filter program, this one won't work if the
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XXX IP packet is fragmented or if there are options on the IP
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XXX header. */
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pf.enf_Priority = 0;
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pf.enf_FilterLen = 0;
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pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 6;
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pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_CAND;
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pf.enf_Filter [pf.enf_FilterLen++] = htons (ETHERTYPE_IP);
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pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT;
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pf.enf_Filter [pf.enf_FilterLen++] = htons (IPPROTO_UDP);
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pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 11;
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pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_AND;
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pf.enf_Filter [pf.enf_FilterLen++] = htons (0xFF);
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pf.enf_Filter [pf.enf_FilterLen++] = ENF_CAND;
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pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 18;
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pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_CAND;
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pf.enf_Filter [pf.enf_FilterLen++] = local_port;
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if (ioctl (info -> rfdesc, EIOCSETF, &pf) < 0)
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error ("Can't install packet filter program: %m");
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if (!quiet_interface_discovery)
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note ("Listening on UPF/%s/%s/%s",
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info -> name,
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print_hw_addr (info -> hw_address.htype,
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info -> hw_address.hlen,
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info -> hw_address.haddr),
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(info -> shared_network ?
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info -> shared_network -> name : "unattached"));
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}
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#endif /* USE_UPF_RECEIVE */
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#ifdef USE_UPF_SEND
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ssize_t send_packet (interface, packet, raw, len, from, to, hto)
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struct interface_info *interface;
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struct packet *packet;
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struct dhcp_packet *raw;
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size_t len;
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struct in_addr from;
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struct sockaddr_in *to;
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struct hardware *hto;
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{
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int bufp = 0;
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unsigned char buf [256];
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struct iovec iov [2];
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/* Assemble the headers... */
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assemble_hw_header (interface, buf, &bufp, hto);
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assemble_udp_ip_header (interface, buf, &bufp, from.s_addr,
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to -> sin_addr.s_addr, to -> sin_port,
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(unsigned char *)raw, len);
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/* Fire it off */
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iov [0].iov_base = (char *)buf;
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iov [0].iov_len = bufp;
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iov [1].iov_base = (char *)raw;
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iov [1].iov_len = len;
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return writev(interface -> wfdesc, iov, 2);
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}
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#endif /* USE_UPF_SEND */
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#ifdef USE_UPF_RECEIVE
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ssize_t receive_packet (interface, buf, len, from, hfrom)
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struct interface_info *interface;
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unsigned char *buf;
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size_t len;
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struct sockaddr_in *from;
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struct hardware *hfrom;
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{
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int nread;
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int length = 0;
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int offset = 0;
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unsigned char ibuf [1500 + sizeof (struct enstamp)];
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int bufix = 0;
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length = read (interface -> rfdesc, ibuf, sizeof ibuf);
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if (length <= 0)
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return length;
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bufix = sizeof (struct enstamp);
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/* Decode the physical header... */
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offset = decode_hw_header (interface, ibuf, bufix, hfrom);
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/* If a physical layer checksum failed (dunno of any
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physical layer that supports this, but WTH), skip this
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packet. */
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if (offset < 0) {
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return 0;
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}
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bufix += offset;
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length -= offset;
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/* Decode the IP and UDP headers... */
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offset = decode_udp_ip_header (interface, ibuf, bufix,
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from, (unsigned char *)0, length);
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/* If the IP or UDP checksum was bad, skip the packet... */
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if (offset < 0)
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return 0;
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bufix += offset;
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length -= offset;
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/* Copy out the data in the packet... */
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memcpy (buf, &ibuf [bufix], length);
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return length;
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}
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#endif
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