1 files changed, 347 insertions, 0 deletions
diff --git a/usr.sbin/dhcp/common/nit.c b/usr.sbin/dhcp/common/nit.c
new file mode 100644
index 00000000000..296c17a3a1c
--- /dev/null
+++ b/usr.sbin/dhcp/common/nit.c
@@ -0,0 +1,347 @@
+/* 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 1.1 1998/08/18 03:43:26 deraadt 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 *)&ifr;
+	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
+        if (!quiet_interface_discovery)
+		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);
+
+        if (!quiet_interface_discovery)
+		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