Virgin import of ISC-DHCP v2.0

7 files changed, 517 insertions, 54 deletions

diff --git a/contrib/isc-dhcp/common/bpf.c b/contrib/isc-dhcp/common/bpf.c
index d1c3b1a..e204dfe 100644
--- a/contrib/isc-dhcp/common/bpf.c
+++ b/contrib/isc-dhcp/common/bpf.c
@@ -42,7 +42,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: bpf.c,v 1.19.2.9 1999/03/29 22:07:12 mellon Exp $ Copyright (c) 1995, 1996, 1998, 1999 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: bpf.c,v 1.19.2.10 1999/05/27 17:44:51 mellon Exp $ Copyright (c) 1995, 1996, 1998, 1999 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -186,6 +186,20 @@ struct bpf_insn dhcp_bpf_filter [] = {
 };
 
 int dhcp_bpf_filter_len = sizeof dhcp_bpf_filter / sizeof (struct bpf_insn);
+
+struct bpf_insn dhcp_bpf_tr_filter [] = {
+        /* accept all token ring packets due to variable length header */
+        /* if we want to get clever, insert the program here */
+
+	/* If we passed all the tests, ask for the whole packet. */
+	BPF_STMT(BPF_RET+BPF_K, (u_int)-1),
+
+	/* Otherwise, drop it. */
+	BPF_STMT(BPF_RET+BPF_K, 0),
+};
+
+int dhcp_bpf_tr_filter_len = (sizeof dhcp_bpf_tr_filter /
+			      sizeof (struct bpf_insn));
 #endif
 
 #if defined (USE_BPF_RECEIVE)
diff --git a/contrib/isc-dhcp/common/ethernet.c b/contrib/isc-dhcp/common/ethernet.c
new file mode 100644
index 0000000..311c3c9
--- /dev/null
+++ b/contrib/isc-dhcp/common/ethernet.c
@@ -0,0 +1,110 @@
+/* packet.c
+
+   Packet assembly code, originally contributed by Archie Cobbs. */
+
+/*
+ * Copyright (c) 1995, 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: ethernet.c,v 1.1.2.1 1999/05/27 17:35:47 mellon Exp $ Copyright (c) 1996 The Internet Software Consortium.  All rights reserved.\n";
+#endif /* not lint */
+
+#include "dhcpd.h"
+
+#if defined (PACKET_ASSEMBLY) || defined (PACKET_DECODING)
+#include "includes/netinet/if_ether.h"
+#endif /* PACKET_ASSEMBLY || PACKET_DECODING */
+
+#if defined (PACKET_ASSEMBLY)
+/* Assemble an hardware header... */
+/* XXX currently only supports ethernet; doesn't check for other types. */
+
+void assemble_ethernet_header (interface, buf, bufix, to)
+	struct interface_info *interface;
+	unsigned char *buf;
+	int *bufix;
+	struct hardware *to;
+{
+	struct ether_header eh;
+
+	if (to && to -> hlen == 6) /* XXX */
+		memcpy (eh.ether_dhost, to -> haddr, sizeof eh.ether_dhost);
+	else
+		memset (eh.ether_dhost, 0xff, sizeof (eh.ether_dhost));
+	if (interface -> hw_address.hlen == sizeof (eh.ether_shost))
+		memcpy (eh.ether_shost, interface -> hw_address.haddr,
+			sizeof (eh.ether_shost));
+	else
+		memset (eh.ether_shost, 0x00, sizeof (eh.ether_shost));
+
+#ifdef BROKEN_FREEBSD_BPF /* Fixed in FreeBSD 2.2 */
+	eh.ether_type = ETHERTYPE_IP;
+#else
+	eh.ether_type = htons (ETHERTYPE_IP);
+#endif
+
+	memcpy (&buf [*bufix], &eh, sizeof eh);
+	*bufix += sizeof eh;
+}
+#endif /* PACKET_ASSEMBLY */
+
+#ifdef PACKET_DECODING
+/* Decode a hardware header... */
+
+ssize_t decode_ethernet_header (interface, buf, bufix, from)
+     struct interface_info *interface;
+     unsigned char *buf;
+     int bufix;
+     struct hardware *from;
+{
+  struct ether_header eh;
+
+  memcpy (&eh, buf + bufix, sizeof eh);
+
+#ifdef USERLAND_FILTER
+  if (ntohs (eh.ether_type) != ETHERTYPE_IP)
+	  return -1;
+#endif
+  memcpy (from -> haddr, eh.ether_shost, sizeof (eh.ether_shost));
+  from -> htype = ARPHRD_ETHER;
+  from -> hlen = sizeof eh.ether_shost;
+
+  return sizeof eh;
+}
+#endif /* PACKET_DECODING */
diff --git a/contrib/isc-dhcp/common/lpf.c b/contrib/isc-dhcp/common/lpf.c
index 4deecf8..9e56684 100644
--- a/contrib/isc-dhcp/common/lpf.c
+++ b/contrib/isc-dhcp/common/lpf.c
@@ -43,7 +43,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: lpf.c,v 1.1.2.8 1999/03/29 22:07:13 mellon Exp $ Copyright (c) 1995, 1996, 1998, 1999 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: lpf.c,v 1.1.2.9 1999/05/27 17:44:52 mellon Exp $ Copyright (c) 1995, 1996, 1998, 1999 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -59,6 +59,9 @@ static char copyright[] =
 #include "includes/netinet/udp.h"
 #include "includes/netinet/if_ether.h"
 
+static void lpf_gen_filter_setup PROTO ((struct interface_info *));
+static void lpf_tr_filter_setup PROTO ((struct interface_info *));
+
 /* Reinitializes the specified interface after an address change.   This
    is not required for packet-filter APIs. */
 
@@ -149,15 +152,36 @@ void if_register_send (info)
    in bpf includes... */
 extern struct sock_filter dhcp_bpf_filter [];
 extern int dhcp_bpf_filter_len;
+extern struct sock_filter dhcp_bpf_tr_filter [];
+extern int dhcp_bpf_tr_filter_len;
 
 void if_register_receive (info)
 	struct interface_info *info;
 {
-	struct sock_fprog p;
-
 	/* Open a LPF device and hang it on this interface... */
 	info -> rfdesc = if_register_lpf (info);
 
+	if (info -> hw_address.htype == HTYPE_IEEE802)
+		lpf_tr_filter_setup (info);
+	else
+		lpf_gen_filter_setup (info);
+
+	if (!quiet_interface_discovery)
+		note ("Listening on LPF/%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 : ""));
+}
+
+static void lpf_gen_filter_setup (info)
+	struct interface_info *info;
+{
+	struct sock_fprog p;
+
 	/* Set up the bpf filter program structure.    This is defined in
 	   bpf.c */
 	p.len = dhcp_bpf_filter_len;
@@ -178,15 +202,35 @@ void if_register_receive (info)
 			       "in your kernel configuration");
 		error ("Can't install packet filter program: %m");
 	}
-	if (!quiet_interface_discovery)
-		note ("Listening on LPF/%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 : ""));
+}
+
+static void lpf_tr_filter_setup (info)
+	struct interface_info *info;
+{
+	struct sock_fprog p;
+
+	/* Set up the bpf filter program structure.    This is defined in
+	   bpf.c */
+	p.len = dhcp_bpf_tr_filter_len;
+	p.filter = dhcp_bpf_tr_filter;
+
+        /* Patch the server port into the LPF  program...
+	   XXX changes to filter program may require changes
+	   XXX to the insn number(s) used below!
+	   XXX Token ring filter is null - when/if we have a filter 
+	   XXX that's not, we'll need this code.
+	   XXX dhcp_bpf_filter [?].k = ntohs (local_port); */
+
+	if (setsockopt (info -> rfdesc, SOL_SOCKET, SO_ATTACH_FILTER, &p,
+			sizeof p) < 0) {
+		if (errno == ENOPROTOOPT || errno == EPROTONOSUPPORT ||
+		    errno == ESOCKTNOSUPPORT || errno == EPFNOSUPPORT ||
+		    errno == EAFNOSUPPORT)
+			error ("socket: %m - make sure %s %s!",
+			       "CONFIG_PACKET and CONFIG_FILTER are defined",
+			       "in your kernel configuration");
+		error ("Can't install packet filter program: %m");
+	}
 }
 #endif /* USE_LPF_RECEIVE */
 
diff --git a/contrib/isc-dhcp/common/memory.c b/contrib/isc-dhcp/common/memory.c
index 871fe07..c293217 100644
--- a/contrib/isc-dhcp/common/memory.c
+++ b/contrib/isc-dhcp/common/memory.c
@@ -42,7 +42,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: memory.c,v 1.35.2.3 1998/11/24 22:32:43 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: memory.c,v 1.35.2.4 1999/05/27 17:47:43 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -527,7 +527,6 @@ int supersede_lease (comp, lease, commit)
 
 		/* Copy the data files, but not the linkages. */
 		comp -> starts = lease -> starts;
-		comp -> timestamp = lease -> timestamp;
 		if (lease -> uid) {
 			if (lease -> uid_len < sizeof (lease -> uid_buf)) {
 				memcpy (comp -> uid_buf,
diff --git a/contrib/isc-dhcp/common/options.c b/contrib/isc-dhcp/common/options.c
index b1c463f..21e1359 100644
--- a/contrib/isc-dhcp/common/options.c
+++ b/contrib/isc-dhcp/common/options.c
@@ -42,11 +42,12 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: options.c,v 1.26.2.7 1999/03/30 02:57:47 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: options.c,v 1.26.2.10 1999/05/06 21:54:34 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #define DHCP_OPTION_DATA
 #include "dhcpd.h"
+#include <ctype.h>
 
 /* Parse all available options out of the specified packet. */
 
@@ -439,7 +440,7 @@ char *pretty_print_option (code, data, len, emit_commas, emit_quotes)
 	int numhunk = -1;
 	int numelem = 0;
 	char fmtbuf [32];
-	int i, j;
+	int i, j, k;
 	char *op = optbuf;
 	unsigned char *dp = data;
 	struct in_addr foo;
@@ -471,11 +472,21 @@ char *pretty_print_option (code, data, len, emit_commas, emit_quotes)
 			numhunk = 0;
 			break;
 		      case 'X':
-			fmtbuf [i] = 'x';
+			for (k = 0; k < len; k++) {
+				if (!isascii (data [k]) ||
+				    !isprint (data [k]))
+					break;
+			}
+			if (k == len) {
+				fmtbuf [i] = 't';
+				numhunk = -2;
+			} else {
+				fmtbuf [i] = 'x';
+				hunksize++;
+				comma = ':';
+				numhunk = 0;
+			}
 			fmtbuf [i + 1] = 0;
-			hunksize++;
-			numhunk = 0;
-			comma = ':';
 			break;
 		      case 't':
 			fmtbuf [i] = 't';
diff --git a/contrib/isc-dhcp/common/packet.c b/contrib/isc-dhcp/common/packet.c
index b5ad427..6a15fcf 100644
--- a/contrib/isc-dhcp/common/packet.c
+++ b/contrib/isc-dhcp/common/packet.c
@@ -3,7 +3,7 @@
    Packet assembly code, originally contributed by Archie Cobbs. */
 
 /*
- * Copyright (c) 1995, 1996 The Internet Software Consortium.
+ * Copyright (c) 1995, 1996, 1999 The Internet Software Consortium.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -42,7 +42,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: packet.c,v 1.18.2.4 1999/04/24 15:31:47 mellon Exp $ Copyright (c) 1996 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: packet.c,v 1.18.2.6 1999/06/10 00:58:16 mellon Exp $ Copyright (c) 1996 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -50,7 +50,6 @@ static char copyright[] =
 #if defined (PACKET_ASSEMBLY) || defined (PACKET_DECODING)
 #include "includes/netinet/ip.h"
 #include "includes/netinet/udp.h"
-#include "includes/netinet/if_ether.h"
 #endif /* PACKET_ASSEMBLY || PACKET_DECODING */
 
 /* Compute the easy part of the checksum on a range of bytes. */
@@ -122,26 +121,13 @@ void assemble_hw_header (interface, buf, bufix, to)
 	int *bufix;
 	struct hardware *to;
 {
-	struct ether_header eh;
-
-	if (to && to -> hlen == 6) /* XXX */
-		memcpy (eh.ether_dhost, to -> haddr, sizeof eh.ether_dhost);
-	else
-		memset (eh.ether_dhost, 0xff, sizeof (eh.ether_dhost));
-	if (interface -> hw_address.hlen == sizeof (eh.ether_shost))
-		memcpy (eh.ether_shost, interface -> hw_address.haddr,
-			sizeof (eh.ether_shost));
+#if defined (HAVE_TR_SUPPORT)
+	if (interface -> hw_address.htype == HTYPE_IEEE802)
+		assemble_tr_header (interface, buf, bufix, to);
 	else
-		memset (eh.ether_shost, 0x00, sizeof (eh.ether_shost));
-
-#ifdef BROKEN_FREEBSD_BPF /* Fixed in FreeBSD 2.2 */
-	eh.ether_type = ETHERTYPE_IP;
-#else
-	eh.ether_type = htons (ETHERTYPE_IP);
 #endif
+		assemble_ethernet_header (interface, buf, bufix, to);
 
-	memcpy (&buf [*bufix], &eh, sizeof eh);
-	*bufix += sizeof eh;
 }
 
 /* UDP header and IP header assembled together for convenience. */
@@ -207,7 +193,6 @@ void assemble_udp_ip_header (interface, buf, bufix,
 
 #ifdef PACKET_DECODING
 /* Decode a hardware header... */
-/* XXX currently only supports ethernet; doesn't check for other types. */
 
 ssize_t decode_hw_header (interface, buf, bufix, from)
      struct interface_info *interface;
@@ -215,19 +200,12 @@ ssize_t decode_hw_header (interface, buf, bufix, from)
      int bufix;
      struct hardware *from;
 {
-  struct ether_header eh;
-
-  memcpy (&eh, buf + bufix, sizeof eh);
-
-#ifdef USERLAND_FILTER
-  if (ntohs (eh.ether_type) != ETHERTYPE_IP)
-	  return -1;
+#if defined (HAVE_TR_SUPPORT)
+	if (interface -> hw_address.htype == HTYPE_IEEE802)
+		return decode_tr_header (interface, buf, bufix, from);
+	else
 #endif
-  memcpy (from -> haddr, eh.ether_shost, sizeof (eh.ether_shost));
-  from -> htype = ARPHRD_ETHER;
-  from -> hlen = sizeof eh.ether_shost;
-
-  return sizeof eh;
+		return decode_ethernet_header (interface, buf, bufix, from);
 }
 
 /* UDP header and IP header decoded together for convenience. */
diff --git a/contrib/isc-dhcp/common/tr.c b/contrib/isc-dhcp/common/tr.c
new file mode 100644
index 0000000..b19c183
--- /dev/null
+++ b/contrib/isc-dhcp/common/tr.c
@@ -0,0 +1,307 @@
+/*
+ * packet_tr.c - token ring interface code, contributed in May of 1999
+ * by Andrew Chittenden
+ */
+
+#include "dhcpd.h"
+
+#if defined (HAVE_TR_SUPPORT) && \
+	(defined (PACKET_ASSEMBLY) || defined (PACKET_DECODING))
+#include "includes/netinet/ip.h"
+#include "includes/netinet/udp.h"
+#include "includes/netinet/if_ether.h"
+#include "netinet/if_tr.h"
+#include <sys/time.h>
+
+/*
+ * token ring device handling subroutines.  These are required as token-ring
+ * does not have a simple on-the-wire header but requires the use of
+ * source routing
+ */
+
+static int insert_source_routing PROTO ((struct trh_hdr *trh, struct interface_info* interface));
+static void save_source_routing PROTO ((struct trh_hdr *trh, struct interface_info* interface));
+static void expire_routes PROTO ((void));
+
+/*
+ * As we keep a list of interesting routing information only, a singly
+ * linked list is all we need
+ */
+struct routing_entry {
+        struct routing_entry *next;
+        unsigned char addr[TR_ALEN];
+        unsigned char iface[5];
+        __u16 rcf;                      /* route control field */
+        __u16 rseg[8];                  /* routing registers */
+        unsigned long access_time;      /* time we last used this entry */
+};
+
+static struct routing_entry *routing_info = NULL;
+
+static int routing_timeout = 10;
+static struct timeval routing_timer;
+
+void assemble_tr_header (interface, buf, bufix, to)
+	struct interface_info *interface;
+	unsigned char *buf;
+	int *bufix;
+	struct hardware *to;
+{
+        struct trh_hdr *trh;
+        int hdr_len;
+        struct trllc *llc;
+
+
+        /* set up the token header */
+        trh = (struct trh_hdr *) &buf[*bufix];
+        if (interface -> hw_address.hlen == sizeof (trh->saddr))
+                memcpy (trh->saddr, interface -> hw_address.haddr,
+                                    sizeof (trh->saddr));
+        else
+                memset (trh->saddr, 0x00, sizeof (trh->saddr));
+
+        if (to && to -> hlen == 6) /* XXX */
+                memcpy (trh->daddr, to -> haddr, sizeof trh->daddr);
+        else
+                memset (trh->daddr, 0xff, sizeof (trh->daddr));
+
+	hdr_len = insert_source_routing (trh, interface);
+
+        trh->ac = AC;
+        trh->fc = LLC_FRAME;
+
+        /* set up the llc header for snap encoding after the tr header */
+        llc = (struct trllc *)(buf + *bufix + hdr_len);
+        llc->dsap = EXTENDED_SAP;
+        llc->ssap = EXTENDED_SAP;
+        llc->llc = UI_CMD;
+        llc->protid[0] = 0;
+        llc->protid[1] = 0;
+        llc->protid[2] = 0;
+        llc->ethertype = htons(ETHERTYPE_IP);
+
+        hdr_len += sizeof(struct trllc);
+
+        *bufix += hdr_len;
+}
+
+
+static unsigned char tr_broadcast[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+
+/*
+ * decoding the token header is a bit complex as you can see here. It is
+ * further complicated by the linux kernel stripping off some valuable
+ * information (see comment below) even though we've asked for the raw
+ * packets.
+ */
+ssize_t decode_tr_header (interface, buf, bufix, from)
+        struct interface_info *interface;
+        unsigned char *buf;
+        int bufix;
+        struct hardware *from;
+{
+        struct trh_hdr *trh = (struct trh_hdr *) buf + bufix;
+        struct trllc *llc;
+	struct ip *ip;
+	struct udphdr *udp;
+        unsigned int route_len = 0;
+        ssize_t hdr_len;
+        struct timeval now;
+
+        /* see whether any source routing information has expired */
+        gettimeofday(&now, NULL);
+
+	if (routing_timer.tv_sec == 0)
+                routing_timer.tv_sec = now.tv_sec + routing_timeout;
+        else if ((now.tv_sec - routing_timer.tv_sec) > 0)
+                expire_routes();
+
+        /* the kernel might have stripped off the source
+         * routing bit. We try a heuristic to determine whether
+         * this is the case and put it back on if so
+         */
+        route_len = (ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8;
+        llc = (struct trllc *)(buf + bufix + sizeof(struct trh_hdr)-TR_MAXRIFLEN+route_len);
+        if (llc->dsap == EXTENDED_SAP
+                        && llc->ssap == EXTENDED_SAP
+                        && llc->llc == UI_CMD
+                        && llc->protid[0] == 0
+                        && llc->protid[1] == 0
+                        && llc->protid[2] == 0) {
+                /* say there is source routing information present */
+                trh->saddr[0] |= TR_RII;	
+        }
+
+	if (trh->saddr[0] & TR_RII)
+                route_len = (ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8;
+        else
+                route_len = 0;
+
+        hdr_len = sizeof (struct trh_hdr) - TR_MAXRIFLEN + route_len;
+
+        /* now filter out unwanted packets: this is based on the packet
+         * filter code in bpf.c */
+        llc = (struct trllc *)(buf + bufix + hdr_len);
+        ip = (struct ip *) (llc + 1);
+        udp = (struct udphdr *) ((unsigned char*) ip + ip->ip_hl * 4);
+
+        /* make sure it is a snap encoded, IP, UDP, unfragmented packet sent
+         * to our port */
+        if (llc->dsap != EXTENDED_SAP
+                        || ntohs(llc->ethertype) != ETHERTYPE_IP
+                        || ip->ip_p != IPPROTO_UDP
+                        || (ip->ip_off & IP_OFFMASK) != 0
+                        || udp->uh_dport != local_port)
+                return -1;
+
+        /* only save source routing information for packets from valued hosts */
+        save_source_routing(trh, interface);
+
+        return hdr_len + sizeof (struct trllc);
+}
+
+/* insert_source_routing inserts source route information into the token ring
+ * header
+ */
+static int insert_source_routing (trh, interface)
+        struct trh_hdr *trh;
+        struct interface_info* interface;
+{
+	struct routing_entry *rover;
+        struct timeval now;
+        unsigned int route_len = 0;
+
+        gettimeofday(&now, NULL);
+
+	/* single route broadcasts as per rfc 1042 */
+	if (memcmp(trh->daddr, tr_broadcast,TR_ALEN) == 0) {
+		trh->saddr[0] |= TR_RII;
+		trh->rcf = ((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK;  
+                trh->rcf |= (TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST);
+		trh->rcf = htons(trh->rcf);
+	} else {
+		/* look for a routing entry */
+                for (rover = routing_info; rover != NULL; rover = rover->next) {
+                        if (memcmp(rover->addr, trh->daddr, TR_ALEN) == 0)
+                                break;
+                }
+
+		if (rover != NULL) {
+                        /* success: route that frame */
+                        if ((rover->rcf & TR_RCF_LEN_MASK) >> 8) {
+                                __u16 rcf = rover->rcf;
+				memcpy(trh->rseg,rover->rseg,sizeof(trh->rseg));
+				rcf ^= TR_RCF_DIR_BIT;	
+				rcf &= ~TR_RCF_BROADCAST_MASK;
+                                trh->rcf = htons(rcf);
+				trh->saddr[0] |= TR_RII;
+			}
+			rover->access_time = now.tv_sec;
+		} else {
+                        /* we don't have any routing information so send a
+                         * limited broadcast */
+                        trh->saddr[0] |= TR_RII;
+                        trh->rcf = ((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK;  
+                        trh->rcf |= (TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST);
+                        trh->rcf = htons(trh->rcf);
+		}
+	}
+
+	/* return how much of the header we've actually used */
+	if (trh->saddr[0] & TR_RII)
+                route_len = (ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8;
+        else
+                route_len = 0;
+
+        return sizeof (struct trh_hdr) - TR_MAXRIFLEN + route_len;
+}
+
+/*
+ * save any source routing information
+ */
+static void save_source_routing(trh, interface)
+        struct trh_hdr *trh;
+        struct interface_info *interface;
+{
+        struct routing_entry *rover;
+        struct timeval now;
+        unsigned char saddr[TR_ALEN];
+        __u16 rcf = 0;
+
+        gettimeofday(&now, NULL);
+
+        memcpy(saddr, trh->saddr, sizeof(saddr));
+        saddr[0] &= 0x7f;   /* strip off source routing present flag */
+
+        /* scan our table to see if we've got it */
+        for (rover = routing_info; rover != NULL; rover = rover->next) {
+                if (memcmp(&rover->addr[0], &saddr[0], TR_ALEN) == 0)
+                        break;
+        }
+
+        /* found an entry so update it with fresh information */
+        if (rover != NULL) {
+                if ((trh->saddr[0] & TR_RII)
+		    && (((ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8) > 2)) {
+                        rcf = ntohs(trh->rcf);
+                        rcf &= ~TR_RCF_BROADCAST_MASK;
+                        memcpy(rover->rseg, trh->rseg, sizeof(rover->rseg));
+                }
+                rover->rcf = rcf;
+                rover->access_time = now.tv_sec;
+                return;     /* that's all folks */
+        }
+
+        /* no entry found, so create one */
+        rover = malloc(sizeof(struct routing_entry));
+        if (rover == NULL) {
+                fprintf(stderr,
+			"%s: unable to save source routing information\n",
+			__FILE__);
+                return;
+        }
+
+        memcpy(rover->addr, saddr, sizeof(rover->addr));
+        memcpy(rover->iface, interface->name, 5);
+        rover->access_time = now.tv_sec;
+        if (trh->saddr[0] & TR_RII) {
+                if (((ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8) > 2) {
+                        rcf = ntohs(trh->rcf);
+                        rcf &= ~TR_RCF_BROADCAST_MASK;
+                        memcpy(rover->rseg, trh->rseg, sizeof(rover->rseg));
+                }
+                rover->rcf = rcf;
+        }
+
+        /* insert into list */
+        rover->next = routing_info;
+        routing_info = rover;
+
+        return;
+}
+
+/*
+ * get rid of old routes
+ */
+static void expire_routes()
+{
+        struct routing_entry *rover;
+        struct routing_entry **prover = &routing_info;
+        struct timeval now;
+
+        gettimeofday(&now, NULL);
+
+        while((rover = *prover) != NULL) {
+                if ((now.tv_sec - rover->access_time) > routing_timeout) {
+                        *prover = rover->next;
+                        free(rover);
+                } else
+                        prover = &rover->next;
+        }
+
+        /* Reset the timer */
+        routing_timer.tv_sec = now.tv_sec + routing_timeout;
+        routing_timer.tv_usec = now.tv_usec;
+}
+
+#endif