430 lines
12 KiB
C
430 lines
12 KiB
C
/* nit.c
|
|
|
|
Network Interface Tap (NIT) network interface code, by Ted Lemon
|
|
with one crucial tidbit of help from Stu Grossmen. */
|
|
|
|
/*
|
|
* Copyright (c) 1996-2000 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 in cooperation with Vixie Enterprises and Nominum, Inc.
|
|
* To learn more about the Internet Software Consortium, see
|
|
* ``http://www.isc.org/''. To learn more about Vixie Enterprises,
|
|
* see ``http://www.vix.com''. To learn more about Nominum, Inc., see
|
|
* ``http://www.nominum.com''.
|
|
*/
|
|
|
|
#ifndef lint
|
|
static char copyright[] =
|
|
"$Id: nit.c,v 1.1.1.1 2001/08/03 11:35:32 drochner Exp $ Copyright (c) 1996-2000 The Internet Software Consortium. All rights reserved.\n";
|
|
#endif /* not lint */
|
|
|
|
#include "dhcpd.h"
|
|
#if defined (USE_NIT_SEND) || defined (USE_NIT_RECEIVE)
|
|
#include <sys/ioctl.h>
|
|
#include <sys/uio.h>
|
|
|
|
#include <sys/time.h>
|
|
#include <net/nit.h>
|
|
#include <net/nit_if.h>
|
|
#include <net/nit_pf.h>
|
|
#include <net/nit_buf.h>
|
|
#include <sys/stropts.h>
|
|
#include <net/packetfilt.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_NIT_SEND
|
|
void if_reinitialize_send (info)
|
|
struct interface_info *info;
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#ifdef USE_NIT_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_nit (info)
|
|
struct interface_info *info;
|
|
{
|
|
int sock;
|
|
char filename[50];
|
|
struct ifreq ifr;
|
|
struct strioctl sio;
|
|
|
|
/* Open a NIT device */
|
|
sock = open ("/dev/nit", O_RDWR);
|
|
if (sock < 0)
|
|
log_fatal ("Can't open NIT device for %s: %m", info -> name);
|
|
|
|
/* Set the NIT device to point at this interface. */
|
|
sio.ic_cmd = NIOCBIND;
|
|
sio.ic_len = sizeof *(info -> ifp);
|
|
sio.ic_dp = (char *)(info -> ifp);
|
|
sio.ic_timout = INFTIM;
|
|
if (ioctl (sock, I_STR, &sio) < 0)
|
|
log_fatal ("Can't attach interface %s to nit device: %m",
|
|
info -> name);
|
|
|
|
/* Get the low-level address... */
|
|
sio.ic_cmd = SIOCGIFADDR;
|
|
sio.ic_len = sizeof ifr;
|
|
sio.ic_dp = (char *)𝔦
|
|
sio.ic_timout = INFTIM;
|
|
if (ioctl (sock, I_STR, &sio) < 0)
|
|
log_fatal ("Can't get physical layer address for %s: %m",
|
|
info -> name);
|
|
|
|
/* XXX code below assumes ethernet interface! */
|
|
info -> hw_address.hlen = 7;
|
|
info -> hw_address.hbuf [0] = ARPHRD_ETHER;
|
|
memcpy (&info -> hw_address.hbuf [1],
|
|
ifr.ifr_ifru.ifru_addr.sa_data, 6);
|
|
|
|
if (ioctl (sock, I_PUSH, "pf") < 0)
|
|
log_fatal ("Can't push packet filter onto NIT for %s: %m",
|
|
info -> name);
|
|
|
|
return sock;
|
|
}
|
|
#endif /* USE_NIT_SEND || USE_NIT_RECEIVE */
|
|
|
|
#ifdef USE_NIT_SEND
|
|
void if_register_send (info)
|
|
struct interface_info *info;
|
|
{
|
|
/* If we're using the nit API for sending and receiving,
|
|
we don't need to register this interface twice. */
|
|
#ifndef USE_NIT_RECEIVE
|
|
struct packetfilt pf;
|
|
struct strioctl sio;
|
|
|
|
info -> wfdesc = if_register_nit (info);
|
|
|
|
pf.Pf_Priority = 0;
|
|
pf.Pf_FilterLen = 1;
|
|
pf.Pf_Filter [0] = ENF_PUSHZERO;
|
|
|
|
/* Set up an NIT filter that rejects everything... */
|
|
sio.ic_cmd = NIOCSETF;
|
|
sio.ic_len = sizeof pf;
|
|
sio.ic_dp = (char *)&pf;
|
|
sio.ic_timout = INFTIM;
|
|
if (ioctl (info -> wfdesc, I_STR, &sio) < 0)
|
|
log_fatal ("Can't set NIT filter: %m");
|
|
#else
|
|
info -> wfdesc = info -> rfdesc;
|
|
#endif
|
|
if (!quiet_interface_discovery)
|
|
log_info ("Sending on NIT/%s%s%s",
|
|
print_hw_addr (info -> hw_address.hbuf [0],
|
|
info -> hw_address.hlen - 1,
|
|
&info -> hw_address.hbuf [1]),
|
|
(info -> shared_network ? "/" : ""),
|
|
(info -> shared_network ?
|
|
info -> shared_network -> name : ""));
|
|
}
|
|
|
|
void if_deregister_send (info)
|
|
struct interface_info *info;
|
|
{
|
|
/* If we're using the nit API for sending and receiving,
|
|
we don't need to register this interface twice. */
|
|
#ifndef USE_NIT_RECEIVE
|
|
close (info -> wfdesc);
|
|
#endif
|
|
info -> wfdesc = -1;
|
|
if (!quiet_interface_discovery)
|
|
log_info ("Disabling output on NIT/%s%s%s",
|
|
print_hw_addr (info -> hw_address.hbuf [0],
|
|
info -> hw_address.hlen - 1,
|
|
&info -> hw_address.hbuf [1]),
|
|
(info -> shared_network ? "/" : ""),
|
|
(info -> shared_network ?
|
|
info -> shared_network -> name : ""));
|
|
}
|
|
#endif /* USE_NIT_SEND */
|
|
|
|
#ifdef USE_NIT_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 NIT program! XXX */
|
|
|
|
void if_register_receive (info)
|
|
struct interface_info *info;
|
|
{
|
|
int flag = 1;
|
|
u_int32_t x;
|
|
struct packetfilt pf;
|
|
struct strioctl sio;
|
|
u_int16_t addr [2];
|
|
struct timeval t;
|
|
|
|
/* Open a NIT device and hang it on this interface... */
|
|
info -> rfdesc = if_register_nit (info);
|
|
|
|
/* Set the snap length to 0, which means always take the whole
|
|
packet. */
|
|
x = 0;
|
|
if (ioctl (info -> rfdesc, NIOCSSNAP, &x) < 0)
|
|
log_fatal ("Can't set NIT snap length on %s: %m", info -> name);
|
|
|
|
/* Set the stream to byte stream mode */
|
|
if (ioctl (info -> rfdesc, I_SRDOPT, RMSGN) != 0)
|
|
log_info ("I_SRDOPT failed on %s: %m", info -> name);
|
|
|
|
#if 0
|
|
/* Push on the chunker... */
|
|
if (ioctl (info -> rfdesc, I_PUSH, "nbuf") < 0)
|
|
log_fatal ("Can't push chunker onto NIT STREAM: %m");
|
|
|
|
/* Set the timeout to zero. */
|
|
t.tv_sec = 0;
|
|
t.tv_usec = 0;
|
|
if (ioctl (info -> rfdesc, NIOCSTIME, &t) < 0)
|
|
log_fatal ("Can't set chunk timeout: %m");
|
|
#endif
|
|
|
|
/* Ask for no header... */
|
|
x = 0;
|
|
if (ioctl (info -> rfdesc, NIOCSFLAGS, &x) < 0)
|
|
log_fatal ("Can't set NIT flags on %s: %m", info -> name);
|
|
|
|
/* Set up the NIT 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.Pf_Priority = 0;
|
|
pf.Pf_FilterLen = 0;
|
|
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHWORD + 6;
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT + ENF_CAND;
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = htons (ETHERTYPE_IP);
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT;
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = htons (IPPROTO_UDP);
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHWORD + 11;
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT + ENF_AND;
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = htons (0xFF);
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_CAND;
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHWORD + 18;
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = ENF_PUSHLIT + ENF_CAND;
|
|
pf.Pf_Filter [pf.Pf_FilterLen++] = local_port;
|
|
|
|
/* Install the filter... */
|
|
sio.ic_cmd = NIOCSETF;
|
|
sio.ic_len = sizeof pf;
|
|
sio.ic_dp = (char *)&pf;
|
|
sio.ic_timout = INFTIM;
|
|
if (ioctl (info -> rfdesc, I_STR, &sio) < 0)
|
|
log_fatal ("Can't set NIT filter on %s: %m", info -> name);
|
|
|
|
if (!quiet_interface_discovery)
|
|
log_info ("Listening on NIT/%s%s%s",
|
|
print_hw_addr (info -> hw_address.hbuf [0],
|
|
info -> hw_address.hlen - 1,
|
|
&info -> hw_address.hbuf [1]),
|
|
(info -> shared_network ? "/" : ""),
|
|
(info -> shared_network ?
|
|
info -> shared_network -> name : ""));
|
|
}
|
|
|
|
void if_deregister_receive (info)
|
|
struct interface_info *info;
|
|
{
|
|
/* If we're using the nit API for sending and receiving,
|
|
we don't need to register this interface twice. */
|
|
close (info -> rfdesc);
|
|
info -> rfdesc = -1;
|
|
|
|
if (!quiet_interface_discovery)
|
|
log_info ("Disabling input on NIT/%s%s%s",
|
|
print_hw_addr (info -> hw_address.hbuf [0],
|
|
info -> hw_address.hlen - 1,
|
|
&info -> hw_address.hbuf [1]),
|
|
(info -> shared_network ? "/" : ""),
|
|
(info -> shared_network ?
|
|
info -> shared_network -> name : ""));
|
|
}
|
|
#endif /* USE_NIT_RECEIVE */
|
|
|
|
#ifdef USE_NIT_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;
|
|
{
|
|
unsigned hbufp, ibufp;
|
|
double hh [16];
|
|
double ih [1536 / sizeof (double)];
|
|
unsigned char *buf = (unsigned char *)ih;
|
|
struct sockaddr *junk;
|
|
struct strbuf ctl, data;
|
|
struct sockaddr_in foo;
|
|
int result;
|
|
|
|
if (!strcmp (interface -> name, "fallback"))
|
|
return send_fallback (interface, packet, raw,
|
|
len, from, to, hto);
|
|
|
|
/* Start with the sockaddr struct... */
|
|
junk = (struct sockaddr *)&hh [0];
|
|
hbufp = (((unsigned char *)&junk -> sa_data [0]) -
|
|
(unsigned char *)&hh[0]);
|
|
ibufp = 0;
|
|
|
|
/* Assemble the headers... */
|
|
assemble_hw_header (interface, (unsigned char *)junk, &hbufp, hto);
|
|
assemble_udp_ip_header (interface, buf, &ibufp,
|
|
from.s_addr, to -> sin_addr.s_addr,
|
|
to -> sin_port, (unsigned char *)raw, len);
|
|
|
|
/* Copy the data into the buffer (yuk). */
|
|
memcpy (buf + ibufp, raw, len);
|
|
|
|
/* Set up the sockaddr structure... */
|
|
#if USE_SIN_LEN
|
|
junk -> sa_len = hbufp - 2; /* XXX */
|
|
#endif
|
|
junk -> sa_family = AF_UNSPEC;
|
|
|
|
/* Set up the msg_buf structure... */
|
|
ctl.buf = (char *)&hh [0];
|
|
ctl.maxlen = ctl.len = hbufp;
|
|
data.buf = (char *)&ih [0];
|
|
data.maxlen = data.len = ibufp + len;
|
|
|
|
result = putmsg (interface -> wfdesc, &ctl, &data, 0);
|
|
if (result < 0)
|
|
log_error ("send_packet: %m");
|
|
return result;
|
|
}
|
|
#endif /* USE_NIT_SEND */
|
|
|
|
#ifdef USE_NIT_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 [1536];
|
|
int bufix = 0;
|
|
|
|
length = read (interface -> rfdesc, ibuf, sizeof ibuf);
|
|
if (length <= 0)
|
|
return length;
|
|
|
|
/* 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 (ip)
|
|
struct interface_info *ip;
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
int can_receive_unicast_unconfigured (ip)
|
|
struct interface_info *ip;
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
int supports_multiple_interfaces (ip)
|
|
struct interface_info *ip;
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
void maybe_setup_fallback ()
|
|
{
|
|
isc_result_t status;
|
|
struct interface_info *fbi = (struct interface_info *)0;
|
|
if (setup_fallback (&fbi, MDL)) {
|
|
if_register_fallback (fbi);
|
|
status = omapi_register_io_object ((omapi_object_t *)fbi,
|
|
if_readsocket, 0,
|
|
fallback_discard, 0, 0);
|
|
if (status != ISC_R_SUCCESS)
|
|
log_fatal ("Can't register I/O handle for %s: %s",
|
|
fbi -> name, isc_result_totext (status));
|
|
interface_dereference (&fbi, MDL);
|
|
}
|
|
}
|
|
#endif
|