Index: /trunk/src/VBox/Devices/Network/slirp/tcp_output.c
===================================================================
--- /trunk/src/VBox/Devices/Network/slirp/tcp_output.c	(revision 22895)
+++ /trunk/src/VBox/Devices/Network/slirp/tcp_output.c	(revision 22896)
@@ -76,5 +76,5 @@
     register long len, win;
     int off, flags, error;
-    register struct mbuf *m;
+    register struct mbuf *m = NULL;
     register struct tcpiphdr *ti;
     u_char opt[MAX_TCPOPTLEN];
@@ -371,5 +371,10 @@
         }
 
+#ifndef VBOX_WITH_SLIRP_BSD_MBUF
         m = m_get(pData);
+#else
+        m = m_gethdr(pData, M_NOWAIT, MT_HEADER);
+        /* @todo (r=vvl) should we append other bufs here ???*/
+#endif
         if (m == NULL)
         {
@@ -378,6 +383,8 @@
             goto out;
         }
+#ifndef VBOX_WITH_SLIRP_BSD_MBUF
         m->m_data += if_maxlinkhdr;
         m->m_len = hdrlen;
+#endif
 
         /*
@@ -389,6 +396,11 @@
         {
 #endif
+#ifndef VBOX_WITH_SLIRP_BSD_MBUF
             sbcopy(&so->so_snd, off, (int) len, mtod(m, caddr_t) + hdrlen);
             m->m_len += len;
+#else
+            sbcopy(pData, &so->so_snd, off, (int) len, m);
+            m = m_prepend(pData, m, sizeof (struct tcpiphdr), M_DONTWAIT);
+#endif
 #if 0
         }
@@ -420,4 +432,5 @@
             tcpstat.tcps_sndwinup++;
 
+#ifndef VBOX_WITH_SLIRP_BSD_MBUF
         m = m_get(pData);
         if (m == NULL)
@@ -429,9 +442,25 @@
         m->m_data += if_maxlinkhdr;
         m->m_len = hdrlen;
-    }
-
+#else
+        m = m_gethdr(pData, M_NOWAIT, MT_HEADER);
+        if (m == NULL)
+        {
+/*          error = ENOBUFS; */
+            error = 1;
+            goto out;
+        }
+#endif
+    }
+
+#ifndef VBOX_WITH_SLIRP_BSD_MBUF
     ti = mtod(m, struct tcpiphdr *);
 
     memcpy((caddr_t)ti, &tp->t_template, sizeof (struct tcpiphdr));
+#else
+    /*already copied header from template */
+
+    m_copyback(pData, m, 0, sizeof (struct tcpiphdr), &tp->t_template);
+    ti = mtod(m, struct tcpiphdr *);
+#endif
 
     /*
@@ -464,5 +493,9 @@
     if (optlen)
     {
+#ifndef VBOX_WITH_SLIRP_BSD_MBUF
         memcpy((caddr_t)(ti + 1), (caddr_t)opt, optlen);
+#else
+        m_append(pData, m,  optlen, opt);
+#endif
         ti->ti_off = (sizeof (struct tcphdr) + optlen) >> 2;
     }
@@ -575,11 +608,20 @@
      * the template, but need a way to checksum without them.
      */
+#ifndef VBOX_WITH_SLIRP_BSD_MBUF
     Assert(m->m_len == (hdrlen + len));
     m->m_len = hdrlen + len; /* XXX Needed? m_len should be correct */
-
-    {
+#else
+    M_ASSERTPKTHDR(m);
+    m->m_pkthdr.header = mtod(m, void *);
+#endif
+
+    {
+#ifndef VBOX_WITH_SLIRP_BSD_MBUF
         ((struct ip *)ti)->ip_len = m->m_len;
+#else
+       ((struct ip *)ti)->ip_len = m_length(m, NULL);
+#endif
         ((struct ip *)ti)->ip_ttl = ip_defttl;
-        ((struct ip *)ti)->ip_tos = so->so_iptos;
+       ((struct ip *)ti)->ip_tos = so->so_iptos;
 
         /* #if BSD >= 43 */
@@ -589,6 +631,8 @@
                          so->so_options & SO_DONTROUTE, 0);
 #endif
+#ifndef VBOX_WITH_SLIRP_BSD_MBUF
         if(so->so_la != NULL)
             m->m_la = so->so_la;
+#endif
         error = ip_output(pData, so, m);