freebsd-dev/contrib/isc-dhcp/common/upf.c
1999-05-02 09:03:51 +00:00

331 lines
9.6 KiB
C

/* upf.c
Ultrix PacketFilter interface code. */
/*
* Copyright (c) 1995, 1996, 1997, 1998, 1999
* 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: upf.c,v 1.3.2.5 1999/03/29 22:07:13 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998, 1999 The Internet Software Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
#if defined (USE_UPF_SEND) || defined (USE_UPF_RECEIVE)
#include <sys/ioctl.h>
#include <sys/uio.h>
#include <net/pfilt.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_UPF_SEND
void if_reinitialize_send (info)
struct interface_info *info;
{
}
#endif
#ifdef USE_UPF_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_upf (info)
struct interface_info *info;
{
int sock;
char filename[50];
int b;
struct endevp param;
/* Open a UPF device */
for (b = 0; 1; b++) {
#ifndef NO_SNPRINTF
snprintf(filename, sizeof(filename), "/dev/pf/pfilt%d", b);
#else
sprintf(filename, "/dev/pf/pfilt%d", b);
#endif
sock = open (filename, O_RDWR, 0);
if (sock < 0) {
if (errno == EBUSY) {
continue;
} else {
error ("Can't find free upf: %m");
}
} else {
break;
}
}
/* Set the UPF device to point at this interface. */
if (ioctl (sock, EIOCSETIF, info -> ifp) < 0)
error ("Can't attach interface %s to upf device %s: %m",
info -> name, filename);
/* Get the hardware address. */
if (ioctl (sock, EIOCDEVP, &param) < 0)
error ("Can't get interface %s hardware address: %m",
info -> name);
/* We only know how to do ethernet. */
if (param.end_dev_type != ENDT_10MB)
error ("Invalid device type on network interface %s: %d",
info -> name, param.end_dev_type);
if (param.end_addr_len != 6)
error ("Invalid hardware address length on %s: %d",
info -> name, param.end_addr_len);
info -> hw_address.hlen = 6;
info -> hw_address.htype = ARPHRD_ETHER;
memcpy (&info -> hw_address.haddr [0], param.end_addr, 6);
return sock;
}
#endif /* USE_UPF_SEND || USE_UPF_RECEIVE */
#ifdef USE_UPF_SEND
void if_register_send (info)
struct interface_info *info;
{
/* If we're using the upf API for sending and receiving,
we don't need to register this interface twice. */
#ifndef USE_UPF_RECEIVE
info -> wfdesc = if_register_upf (info, interface);
#else
info -> wfdesc = info -> rfdesc;
#endif
if (!quiet_interface_discovery)
note ("Sending on UPF/%s/%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 ?
info -> shared_network -> name : ""));
}
#endif /* USE_UPF_SEND */
#ifdef USE_UPF_RECEIVE
/* Packet filter program...
XXX Changes to the filter program may require changes to the constant
offsets used in if_register_send to patch the UPF program! XXX */
void if_register_receive (info)
struct interface_info *info;
{
int flag = 1;
u_int32_t addr;
struct enfilter pf;
u_int32_t bits;
/* Open a UPF device and hang it on this interface... */
info -> rfdesc = if_register_upf (info);
/* Allow the copyall flag to be set... */
if (ioctl(info -> rfdesc, EIOCALLOWCOPYALL, &flag) < 0)
error ("Can't set ALLOWCOPYALL: %m");
/* Clear all the packet filter mode bits first... */
flag = (ENHOLDSIG | ENBATCH | ENTSTAMP | ENPROMISC |
ENNONEXCL | ENCOPYALL);
if (ioctl (info -> rfdesc, EIOCMBIC, &flag) < 0)
error ("Can't clear pfilt bits: %m");
/* Set the ENBATCH and ENCOPYALL bits... */
bits = ENBATCH | ENCOPYALL;
if (ioctl (info -> rfdesc, EIOCMBIS, &bits) < 0)
error ("Can't set ENBATCH|ENCOPYALL: %m");
/* Set up the UPF filter program. */
/* XXX Unlike the BPF filter program, this one won't work if the
XXX IP packet is fragmented or if there are options on the IP
XXX header. */
pf.enf_Priority = 0;
pf.enf_FilterLen = 0;
pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 6;
pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_CAND;
pf.enf_Filter [pf.enf_FilterLen++] = htons (ETHERTYPE_IP);
pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT;
pf.enf_Filter [pf.enf_FilterLen++] = htons (IPPROTO_UDP);
pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 11;
pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_AND;
pf.enf_Filter [pf.enf_FilterLen++] = htons (0xFF);
pf.enf_Filter [pf.enf_FilterLen++] = ENF_CAND;
pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 18;
pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_CAND;
pf.enf_Filter [pf.enf_FilterLen++] = local_port;
if (ioctl (info -> rfdesc, EIOCSETF, &pf) < 0)
error ("Can't install packet filter program: %m");
if (!quiet_interface_discovery)
note ("Listening on UPF/%s/%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 ?
info -> shared_network -> name : ""));
}
#endif /* USE_UPF_RECEIVE */
#ifdef USE_UPF_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 [256];
struct iovec iov [2];
int result;
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);
/* Fire it off */
iov [0].iov_base = (char *)buf;
iov [0].iov_len = bufp;
iov [1].iov_base = (char *)raw;
iov [1].iov_len = len;
result = writev(interface -> wfdesc, iov, 2);
if (result < 0)
warn ("send_packet: %m");
return result;
}
#endif /* USE_UPF_SEND */
#ifdef USE_UPF_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;
}
int can_receive_unicast_unconfigured (ip)
struct interface_info *ip;
{
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