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/* nit.c
Network Interface Tap (NIT) network interface code, by Ted Lemon
with one crucial tidbit of help from Stu Grossmen. */
/*
* Copyright (c) 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[] =
"$Id: nit.c,v 1.14 1997/06/08 03:18:07 mellon Exp $ Copyright (c) 1996 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)
error ("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)
error ("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)
error ("Can't get physical layer address for %s: %m",
info -> name);
/* XXX code below assumes ethernet interface! */
info -> hw_address.hlen = 6;
info -> hw_address.htype = ARPHRD_ETHER;
memcpy (info -> hw_address.haddr, ifr.ifr_ifru.ifru_addr.sa_data, 6);
if (ioctl (sock, I_PUSH, "pf") < 0)
error ("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)
error ("Can't set NIT filter: %m");
#else
info -> wfdesc = info -> rfdesc;
#endif
note ("Sending on NIT/%s/%s",
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_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)
error ("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)
note ("I_SRDOPT failed on %s: %m", info -> name);
#if 0
/* Push on the chunker... */
if (ioctl (info -> rfdesc, I_PUSH, "nbuf") < 0)
error ("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)
error ("Can't set chunk timeout: %m");
#endif
/* Ask for no header... */
x = 0;
if (ioctl (info -> rfdesc, NIOCSFLAGS, &x) < 0)
error ("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)
error ("Can't set NIT filter on %s: %m", info -> name);
note ("Listening on NIT/%s/%s",
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_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;
{
int bufp;
unsigned char buf [1536 + sizeof (struct sockaddr)];
struct sockaddr *junk;
struct strbuf ctl, data;
int hw_end;
struct sockaddr_in foo;
/* Start with the sockaddr struct... */
junk = (struct sockaddr *)&buf [0];
bufp = ((unsigned char *)&junk -> sa_data [0]) - &buf [0];
/* Assemble the headers... */
assemble_hw_header (interface, buf, &bufp, hto);
hw_end = bufp;
assemble_udp_ip_header (interface, buf, &bufp, from.s_addr,
to -> sin_addr.s_addr, to -> sin_port,
raw, len);
/* Copy the data into the buffer (yuk). */
memcpy (buf + bufp, raw, len);
/* Set up the sockaddr structure... */
#if USE_SIN_LEN
junk -> sa_len = hw_end - 2; /* XXX */
#endif
junk -> sa_family = AF_UNSPEC;
#if 0 /* Already done. */
memcpy (junk.sa_data, buf, hw_len);
#endif
/* Set up the msg_buf structure... */
ctl.buf = (char *)&buf [0];
ctl.maxlen = ctl.len = hw_end;
data.buf = (char *)&buf [hw_end];
data.maxlen = data.len = bufp + len - hw_end;
return putmsg (interface -> wfdesc, &ctl, &data, 0);
}
#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;
}
#endif
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.