diff -urNb mpd-3.18/src/iface.c mpd-3.18.patched/src/iface.c
--- mpd-3.18/src/iface.c	Tue May  4 22:12:28 2004
+++ mpd-3.18.patched/src/iface.c	Fri Jan 21 16:49:54 2005
@@ -28,6 +28,7 @@
 #include <netgraph/ng_message.h>
 #include <netgraph/ng_iface.h>
 #include <netgraph/ng_bpf.h>
+#include <netgraph/ng_tee.h>
 
 /*
  * DEFINITIONS
@@ -279,7 +280,12 @@
 
     /* Reset bpf node statistics */
     memset(&iface->idleStats, 0, sizeof(iface->idleStats));
+    if (gEnableTee) {
+      snprintf(path, sizeof(path), "%s:%s.%s", iface->ifname,
+        NG_IFACE_HOOK_INET, NG_TEE_HOOK_RIGHT);
+    } else {
     snprintf(path, sizeof(path), "%s:%s", iface->ifname, NG_IFACE_HOOK_INET);
+    }
     if (NgSendMsg(bund->csock, path, NGM_BPF_COOKIE,
 	NGM_BPF_CLR_STATS, BPF_HOOK_IFACE, sizeof(BPF_HOOK_IFACE)) < 0)
       Log(LG_ERR, ("[%s] can't clear %s stats: %s",
@@ -832,7 +838,12 @@
 
   /* Get updated bpf node traffic statistics */
   oldStats = iface->idleStats;
+  if (gEnableTee) {
+    snprintf(path, sizeof(path), "%s:%s.%s", iface->ifname,
+      NG_IFACE_HOOK_INET, NG_TEE_HOOK_RIGHT);
+  } else {
   snprintf(path, sizeof(path), "%s:%s", iface->ifname, NG_IFACE_HOOK_INET);
+  }
   if (NgSendMsg(bund->csock, path, NGM_BPF_COOKIE,
       NGM_BPF_GET_STATS, BPF_HOOK_IFACE, sizeof(BPF_HOOK_IFACE)) < 0) {
     Log(LG_ERR, ("[%s] can't get %s stats: %s",
diff -urNb mpd-3.18/src/main.c mpd-3.18.patched/src/main.c
--- mpd-3.18/src/main.c	Tue May  4 22:12:28 2004
+++ mpd-3.18.patched/src/main.c	Fri Jan 21 16:49:54 2005
@@ -64,6 +64,8 @@
 				"Show version information"	},
     { 0, 'h',	"help",		"",
 				"Show usage information"	},
+    { 0, 't',	"tee",		"",
+                                "Insert ng_tee into netgraph"	},
   };
 
   #define OPTLIST_SIZE		(sizeof(OptList) / sizeof(*OptList))
@@ -81,6 +83,7 @@
   Bund			*gBundles;
   int			gNumLinks;
   int			gNumBundles;
+  int			gEnableTee = FALSE;
 
   const char		*gConfigFile = CONF_FILE;
   const char		*gConfDirectory = PATH_CONF_DIR;
@@ -514,6 +517,9 @@
       exit(EX_NORMAL);
     case 'h':
       Usage(EX_NORMAL);
+    case 't':
+      gEnableTee = TRUE;
+      return(0);
     default:
       assert(0);
   }
diff -urNb mpd-3.18/src/ngfunc.c mpd-3.18.patched/src/ngfunc.c
--- mpd-3.18/src/ngfunc.c	Tue May  4 22:12:28 2004
+++ mpd-3.18.patched/src/ngfunc.c	Fri Jan 21 19:39:35 2005
@@ -28,6 +28,7 @@
 #include <netgraph/ng_ppp.h>
 #include <netgraph/ng_vjc.h>
 #include <netgraph/ng_bpf.h>
+#include <netgraph/ng_tee.h>
 
 /*
  * DEFINITIONS
@@ -249,17 +250,30 @@
     goto fail;
   }
 
-  /* Connect the other side of the bpf node to the iface node */
+  /* Connect the other side of the bpf node to the iface or tee node */
   snprintf(path, sizeof(path), "%s.%s", MPD_HOOK_PPP, NG_PPP_HOOK_INET);
+  if (gEnableTee) {
+    snprintf(cn.path, sizeof(cn.path), "%s:%s",
+      b->iface.ifname, NG_IFACE_HOOK_INET);
+    snprintf(cn.peerhook, sizeof(cn.peerhook), "%s", NG_TEE_HOOK_RIGHT);
+  } else {
   snprintf(cn.path, sizeof(cn.path), "%s:", b->iface.ifname);
-  snprintf(cn.ourhook, sizeof(cn.ourhook), "%s", BPF_HOOK_IFACE);
   snprintf(cn.peerhook, sizeof(cn.peerhook), "%s", NG_IFACE_HOOK_INET);
+  }
+  snprintf(cn.ourhook, sizeof(cn.ourhook), "%s", BPF_HOOK_IFACE);
+
   if (NgSendMsg(b->csock, path,
       NGM_GENERIC_COOKIE, NGM_CONNECT, &cn, sizeof(cn)) < 0) {
+    if (gEnableTee) {
+      Log(LG_ERR, ("[%s] can't connect %s and %s: %s",
+        b->name, BPF_HOOK_IFACE, NG_TEE_HOOK_RIGHT, strerror(errno)));
+      goto fail;
+    } else {
     Log(LG_ERR, ("[%s] can't connect %s and %s: %s",
       b->name, BPF_HOOK_IFACE, NG_IFACE_HOOK_INET, strerror(errno)));
     goto fail;
   }
+  }
 
   /* Connect a hook from the bpf node to our socket node */
   snprintf(cn.path, sizeof(cn.path), "%s.%s", MPD_HOOK_PPP, NG_PPP_HOOK_INET);
@@ -390,6 +404,7 @@
   struct nodeinfo	*const ni = (struct nodeinfo *)(void *)u.reply.data;
   struct ngm_rmhook	rm;
   struct ngm_mkpeer	mp;
+  struct ngm_connect	cn;
   int			rtn = 0;
 
   /* If ifname is not null, create interfaces until it gets created */
@@ -441,6 +456,38 @@
   snprintf(buf, max, "%s", ni->name);
 
 done:
+
+  /* Disconnect temporary hook */
+  snprintf(rm.ourhook, sizeof(rm.ourhook), "%s", TEMPHOOK);
+  if (NgSendMsg(b->csock, ".",
+      NGM_GENERIC_COOKIE, NGM_RMHOOK, &rm, sizeof(rm)) < 0) {
+    Log(LG_ERR, ("[%s] can't remove hook %s: %s",
+      b->name, TEMPHOOK, strerror(errno)));
+    rtn = -1;
+  }
+
+  /* Add netgraph tee node to created iface if configured */
+  if (gEnableTee && (rtn != -1)) {
+    /* Create tee node (as a temporary peer of the socket node) */
+    snprintf(mp.type, sizeof(mp.type), "%s", NG_TEE_NODE_TYPE);
+    snprintf(mp.ourhook, sizeof(mp.ourhook), "%s", TEMPHOOK);
+    snprintf(mp.peerhook, sizeof(mp.peerhook), "%s", NG_TEE_HOOK_RIGHT);
+    if (NgSendMsg(b->csock, ".",
+        NGM_GENERIC_COOKIE, NGM_MKPEER, &mp, sizeof(mp)) < 0) {
+      Log(LG_ERR, ("[%s] can't create %s node: %s",
+        b->name, NG_TEE_NODE_TYPE, strerror(errno)));
+      return(-1);
+    }
+    /* Connect tee and iface nodes */
+    snprintf(cn.path, sizeof(cn.path), "%s:", ni->name);
+    snprintf(cn.ourhook, sizeof(cn.ourhook), "%s", NG_TEE_HOOK_LEFT);
+    snprintf(cn.peerhook, sizeof(cn.peerhook), "%s", NG_IFACE_HOOK_INET);
+    if (NgSendMsg(b->csock, TEMPHOOK,
+        NGM_GENERIC_COOKIE, NGM_CONNECT, &cn, sizeof(cn)) < 0) {
+      Log(LG_ERR, ("[%s] can't connect %s and %s: %s",
+        b->name, NG_TEE_HOOK_LEFT, NG_IFACE_HOOK_INET, strerror(errno)));
+      rtn = -1;
+    }
   /* Disconnect temporary hook */
   snprintf(rm.ourhook, sizeof(rm.ourhook), "%s", TEMPHOOK);
   if (NgSendMsg(b->csock, ".",
@@ -449,6 +496,7 @@
       b->name, TEMPHOOK, strerror(errno)));
     rtn = -1;
   }
+  }
 
   /* Done */
   return(rtn);
@@ -473,7 +521,12 @@
   char				path[NG_PATHLEN + 1];
 
   /* Get absolute path to bpf node */
+  if (gEnableTee) {
+    snprintf(path, sizeof(path), "%s:%s.%s", b->iface.ifname,
+      NG_IFACE_HOOK_INET, NG_TEE_HOOK_RIGHT);
+  } else {
   snprintf(path, sizeof(path), "%s:%s", b->iface.ifname, NG_IFACE_HOOK_INET);
+  }
 
   /* First, configure the hook on the interface node side of the BPF node */
   memset(&u, 0, sizeof(u));
@@ -590,10 +643,23 @@
   Bund	bund_save;
   Link	lnk_save;
   int	k;
+  struct ngm_rmhook rm;
 
   if (iface) {
+    if (gEnableTee) {
+      /* Disconnect tee:right hook */
+      snprintf(path, sizeof(path), "%s:%s",
+        b->iface.ifname, NG_IFACE_HOOK_INET);
+      snprintf(rm.ourhook, sizeof(rm.ourhook), "%s", NG_TEE_HOOK_RIGHT);
+      if (NgSendMsg(b->csock, path,
+        NGM_GENERIC_COOKIE, NGM_RMHOOK, &rm, sizeof(rm)) < 0) {
+          Log(LG_ERR, ("[%s] can't remove hook %s: %s",
+            b->name, NG_TEE_HOOK_RIGHT, strerror(errno)));
+      }
+    } else {
     snprintf(path, sizeof(path), "%s:", b->iface.ifname);
     NgFuncShutdownNode(b, b->name, path);
+    }
   }
   lnk_save = lnk;
   bund_save = bund;
diff -urNb mpd-3.18/src/ppp.h mpd-3.18.patched/src/ppp.h
--- mpd-3.18/src/ppp.h	Tue May  4 22:12:28 2004
+++ mpd-3.18.patched/src/ppp.h	Fri Jan 21 16:49:54 2005
@@ -84,6 +84,7 @@
 
   extern int		gNumLinks;		/* Total number of links */
   extern int		gNumBundles;		/* Total number of bundles */
+  extern int		gEnableTee;		/* Insert ng_tee into netgraph */
 
   extern Bund		bund;			/* Current bundle */
   extern Link		lnk;			/* Current link */