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[qemu.git] / slirp / tcp_input.c
index eeee9859725377235cf38efe02fa8e5061c14e8c..f946db8dc07eaed24fa0f9ffffdd12a88c32ce76 100644 (file)
  * 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. All advertising materials mentioning features or use of this software
- *    must display the following acknowledgement:
- *     This product includes software developed by the University of
- *     California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
+ * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
 /*
  * Changes and additions relating to SLiRP
  * Copyright (c) 1995 Danny Gasparovski.
- * 
- * Please read the file COPYRIGHT for the 
+ *
+ * Please read the file COPYRIGHT for the
  * terms and conditions of the copyright.
  */
 
 #include <slirp.h>
 #include "ip_icmp.h"
 
-struct socket tcb;
-
-#define min(x,y) ((x) < (y) ? (x) : (y))
-#define max(x,y) ((x) > (y) ? (x) : (y))
-
-int    tcprexmtthresh = 3;
-struct socket *tcp_last_so = &tcb;
-
-tcp_seq tcp_iss;                /* tcp initial send seq # */
+#define        TCPREXMTTHRESH 3
 
 #define TCP_PAWS_IDLE  (24 * 24 * 60 * 60 * PR_SLOWHZ)
 
@@ -74,7 +62,7 @@ tcp_seq tcp_iss;                /* tcp initial send seq # */
 #ifdef TCP_ACK_HACK
 #define TCP_REASS(tp, ti, m, so, flags) {\
        if ((ti)->ti_seq == (tp)->rcv_nxt && \
-           (tp)->seg_next == (tcpiphdrp_32)(tp) && \
+           tcpfrag_list_empty(tp) && \
            (tp)->t_state == TCPS_ESTABLISHED) {\
                if (ti->ti_flags & TH_PUSH) \
                        tp->t_flags |= TF_ACKNOW; \
@@ -82,13 +70,10 @@ tcp_seq tcp_iss;                /* tcp initial send seq # */
                        tp->t_flags |= TF_DELACK; \
                (tp)->rcv_nxt += (ti)->ti_len; \
                flags = (ti)->ti_flags & TH_FIN; \
-               tcpstat.tcps_rcvpack++;\
-               tcpstat.tcps_rcvbyte += (ti)->ti_len;\
                if (so->so_emu) { \
                       if (tcp_emu((so),(m))) sbappend((so), (m)); \
               } else \
                       sbappend((so), (m)); \
-/*               sorwakeup(so); */ \
        } else {\
                (flags) = tcp_reass((tp), (ti), (m)); \
                tp->t_flags |= TF_ACKNOW; \
@@ -97,47 +82,45 @@ tcp_seq tcp_iss;                /* tcp initial send seq # */
 #else
 #define        TCP_REASS(tp, ti, m, so, flags) { \
        if ((ti)->ti_seq == (tp)->rcv_nxt && \
-           (tp)->seg_next == (tcpiphdrp_32)(tp) && \
+        tcpfrag_list_empty(tp) && \
            (tp)->t_state == TCPS_ESTABLISHED) { \
                tp->t_flags |= TF_DELACK; \
                (tp)->rcv_nxt += (ti)->ti_len; \
                flags = (ti)->ti_flags & TH_FIN; \
-               tcpstat.tcps_rcvpack++;\
-               tcpstat.tcps_rcvbyte += (ti)->ti_len;\
                if (so->so_emu) { \
                        if (tcp_emu((so),(m))) sbappend(so, (m)); \
                } else \
                        sbappend((so), (m)); \
-/*             sorwakeup(so); */ \
        } else { \
                (flags) = tcp_reass((tp), (ti), (m)); \
                tp->t_flags |= TF_ACKNOW; \
        } \
 }
 #endif
+static void tcp_dooptions(struct tcpcb *tp, u_char *cp, int cnt,
+                          struct tcpiphdr *ti);
+static void tcp_xmit_timer(register struct tcpcb *tp, int rtt);
 
-int
-tcp_reass(tp, ti, m)
-       register struct tcpcb *tp;
-       register struct tcpiphdr *ti;
-       struct mbuf *m;
+static int
+tcp_reass(register struct tcpcb *tp, register struct tcpiphdr *ti,
+          struct mbuf *m)
 {
        register struct tcpiphdr *q;
        struct socket *so = tp->t_socket;
        int flags;
-       
+
        /*
-        * Call with ti==0 after become established to
+        * Call with ti==NULL after become established to
         * force pre-ESTABLISHED data up to user socket.
         */
-       if (ti == 0)
+        if (ti == NULL)
                goto present;
 
        /*
         * Find a segment which begins after this one does.
         */
-       for (q = (struct tcpiphdr *)tp->seg_next; q != (struct tcpiphdr *)tp;
-           q = (struct tcpiphdr *)q->ti_next)
+       for (q = tcpfrag_list_first(tp); !tcpfrag_list_end(q, tp);
+            q = tcpiphdr_next(q))
                if (SEQ_GT(q->ti_seq, ti->ti_seq))
                        break;
 
@@ -146,16 +129,14 @@ tcp_reass(tp, ti, m)
         * our data already.  If so, drop the data from the incoming
         * segment.  If it provides all of our data, drop us.
         */
-       if ((struct tcpiphdr *)q->ti_prev != (struct tcpiphdr *)tp) {
+       if (!tcpfrag_list_end(tcpiphdr_prev(q), tp)) {
                register int i;
-               q = (struct tcpiphdr *)q->ti_prev;
+               q = tcpiphdr_prev(q);
                /* conversion to int (in i) handles seq wraparound */
                i = q->ti_seq + q->ti_len - ti->ti_seq;
                if (i > 0) {
                        if (i >= ti->ti_len) {
-                               tcpstat.tcps_rcvduppack++;
-                               tcpstat.tcps_rcvdupbyte += ti->ti_len;
-                               m_freem(m);
+                               m_free(m);
                                /*
                                 * Try to present any queued data
                                 * at the left window edge to the user.
@@ -168,36 +149,34 @@ tcp_reass(tp, ti, m)
                        ti->ti_len -= i;
                        ti->ti_seq += i;
                }
-               q = (struct tcpiphdr *)(q->ti_next);
+               q = tcpiphdr_next(q);
        }
-       tcpstat.tcps_rcvoopack++;
-       tcpstat.tcps_rcvoobyte += ti->ti_len;
-       REASS_MBUF(ti) = (mbufp_32) m;          /* XXX */
+       ti->ti_mbuf = m;
 
        /*
         * While we overlap succeeding segments trim them or,
         * if they are completely covered, dequeue them.
         */
-       while (q != (struct tcpiphdr *)tp) {
+       while (!tcpfrag_list_end(q, tp)) {
                register int i = (ti->ti_seq + ti->ti_len) - q->ti_seq;
                if (i <= 0)
                        break;
                if (i < q->ti_len) {
                        q->ti_seq += i;
                        q->ti_len -= i;
-                       m_adj((struct mbuf *) REASS_MBUF(q), i);
+                       m_adj(q->ti_mbuf, i);
                        break;
                }
-               q = (struct tcpiphdr *)q->ti_next;
-               m = (struct mbuf *) REASS_MBUF((struct tcpiphdr *)q->ti_prev);
-               remque_32((void *)(q->ti_prev));
-               m_freem(m);
+               q = tcpiphdr_next(q);
+               m = tcpiphdr_prev(q)->ti_mbuf;
+               remque(tcpiphdr2qlink(tcpiphdr_prev(q)));
+               m_free(m);
        }
 
        /*
         * Stick new segment in its place.
         */
-       insque_32(ti, (void *)(q->ti_prev));
+       insque(tcpiphdr2qlink(ti), tcpiphdr2qlink(tcpiphdr_prev(q)));
 
 present:
        /*
@@ -206,20 +185,19 @@ present:
         */
        if (!TCPS_HAVEESTABLISHED(tp->t_state))
                return (0);
-       ti = (struct tcpiphdr *) tp->seg_next;
-       if (ti == (struct tcpiphdr *)tp || ti->ti_seq != tp->rcv_nxt)
+       ti = tcpfrag_list_first(tp);
+       if (tcpfrag_list_end(ti, tp) || ti->ti_seq != tp->rcv_nxt)
                return (0);
        if (tp->t_state == TCPS_SYN_RECEIVED && ti->ti_len)
                return (0);
        do {
                tp->rcv_nxt += ti->ti_len;
                flags = ti->ti_flags & TH_FIN;
-               remque_32(ti);
-               m = (struct mbuf *) REASS_MBUF(ti); /* XXX */
-               ti = (struct tcpiphdr *)ti->ti_next;
-/*             if (so->so_state & SS_FCANTRCVMORE) */
+               remque(tcpiphdr2qlink(ti));
+               m = ti->ti_mbuf;
+               ti = tcpiphdr_next(ti);
                if (so->so_state & SS_FCANTSENDMORE)
-                       m_freem(m);
+                       m_free(m);
                else {
                        if (so->so_emu) {
                                if (tcp_emu(so,m)) sbappend(so, m);
@@ -227,7 +205,6 @@ present:
                                sbappend(so, m);
                }
        } while (ti != (struct tcpiphdr *)tp && ti->ti_seq == tp->rcv_nxt);
-/*     sorwakeup(so); */
        return (flags);
 }
 
@@ -236,49 +213,46 @@ present:
  * protocol specification dated September, 1981 very closely.
  */
 void
-tcp_input(m, iphlen, inso)
-       register struct mbuf *m;
-       int iphlen;
-       struct socket *inso;
+tcp_input(struct mbuf *m, int iphlen, struct socket *inso)
 {
        struct ip save_ip, *ip;
        register struct tcpiphdr *ti;
        caddr_t optp = NULL;
        int optlen = 0;
        int len, tlen, off;
-       register struct tcpcb *tp = 0;
+        register struct tcpcb *tp = NULL;
        register int tiflags;
-       struct socket *so = 0;
+        struct socket *so = NULL;
        int todrop, acked, ourfinisacked, needoutput = 0;
-/*     int dropsocket = 0; */
        int iss = 0;
        u_long tiwin;
        int ret;
-/*     int ts_present = 0; */
+    struct ex_list *ex_ptr;
+    Slirp *slirp;
 
        DEBUG_CALL("tcp_input");
-       DEBUG_ARGS((dfd," m = %8lx  iphlen = %2d  inso = %lx\n", 
+       DEBUG_ARGS((dfd, " m = %8lx  iphlen = %2d  inso = %lx\n",
                    (long )m, iphlen, (long )inso ));
-       
+
        /*
         * If called with m == 0, then we're continuing the connect
         */
        if (m == NULL) {
                so = inso;
-               
+               slirp = so->slirp;
+
                /* Re-set a few variables */
                tp = sototcpcb(so);
                m = so->so_m;
-               so->so_m = 0;
+                so->so_m = NULL;
                ti = so->so_ti;
                tiwin = ti->ti_win;
                tiflags = ti->ti_flags;
-               
+
                goto cont_conn;
        }
-       
-       
-       tcpstat.tcps_rcvtotal++;
+       slirp = m->slirp;
+
        /*
         * Get IP and TCP header together in first mbuf.
         * Note: IP leaves IP header in first mbuf.
@@ -289,29 +263,26 @@ tcp_input(m, iphlen, inso)
          iphlen=sizeof(struct ip );
        }
        /* XXX Check if too short */
-       
+
 
        /*
         * Save a copy of the IP header in case we want restore it
         * for sending an ICMP error message in response.
         */
        ip=mtod(m, struct ip *);
-       save_ip = *ip; 
+       save_ip = *ip;
        save_ip.ip_len+= iphlen;
 
        /*
         * Checksum extended TCP header and data.
         */
        tlen = ((struct ip *)ti)->ip_len;
-       ti->ti_next = ti->ti_prev = 0;
+        tcpiphdr2qlink(ti)->next = tcpiphdr2qlink(ti)->prev = NULL;
+        memset(&ti->ti_i.ih_mbuf, 0 , sizeof(struct mbuf_ptr));
        ti->ti_x1 = 0;
-       ti->ti_len = htons((u_int16_t)tlen);
+       ti->ti_len = htons((uint16_t)tlen);
        len = sizeof(struct ip ) + tlen;
-       /* keep checksum for ICMP reply
-        * ti->ti_sum = cksum(m, len); 
-        * if (ti->ti_sum) { */
        if(cksum(m, len)) {
-         tcpstat.tcps_rcvbadsum++;
          goto drop;
        }
 
@@ -321,7 +292,6 @@ tcp_input(m, iphlen, inso)
         */
        off = ti->ti_off << 2;
        if (off < sizeof (struct tcphdr) || off > tlen) {
-         tcpstat.tcps_rcvbadoff++;
          goto drop;
        }
        tlen -= off;
@@ -329,28 +299,9 @@ tcp_input(m, iphlen, inso)
        if (off > sizeof (struct tcphdr)) {
          optlen = off - sizeof (struct tcphdr);
          optp = mtod(m, caddr_t) + sizeof (struct tcpiphdr);
-
-               /* 
-                * Do quick retrieval of timestamp options ("options
-                * prediction?").  If timestamp is the only option and it's
-                * formatted as recommended in RFC 1323 appendix A, we
-                * quickly get the values now and not bother calling
-                * tcp_dooptions(), etc.
-                */
-/*             if ((optlen == TCPOLEN_TSTAMP_APPA ||
- *                  (optlen > TCPOLEN_TSTAMP_APPA &&
- *                     optp[TCPOLEN_TSTAMP_APPA] == TCPOPT_EOL)) &&
- *                  *(u_int32_t *)optp == htonl(TCPOPT_TSTAMP_HDR) &&
- *                  (ti->ti_flags & TH_SYN) == 0) {
- *                     ts_present = 1;
- *                     ts_val = ntohl(*(u_int32_t *)(optp + 4));
- *                     ts_ecr = ntohl(*(u_int32_t *)(optp + 8));
- *                     optp = NULL;   / * we've parsed the options * /
- *             }
- */
        }
        tiflags = ti->ti_flags;
-       
+
        /*
         * Convert TCP protocol specific fields to host format.
         */
@@ -364,21 +315,20 @@ tcp_input(m, iphlen, inso)
         */
        m->m_data += sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
        m->m_len  -= sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr);
-       
+
        /*
         * Locate pcb for segment.
         */
 findso:
-       so = tcp_last_so;
+       so = slirp->tcp_last_so;
        if (so->so_fport != ti->ti_dport ||
            so->so_lport != ti->ti_sport ||
            so->so_laddr.s_addr != ti->ti_src.s_addr ||
            so->so_faddr.s_addr != ti->ti_dst.s_addr) {
-               so = solookup(&tcb, ti->ti_src, ti->ti_sport,
+               so = solookup(&slirp->tcb, ti->ti_src, ti->ti_sport,
                               ti->ti_dst, ti->ti_dport);
                if (so)
-                       tcp_last_so = so;
-               ++tcpstat.tcps_socachemiss;
+                       slirp->tcp_last_so = so;
        }
 
        /*
@@ -388,41 +338,54 @@ findso:
         * but should either do a listen or a connect soon.
         *
         * state == CLOSED means we've done socreate() but haven't
-        * attached it to a protocol yet... 
-        * 
+        * attached it to a protocol yet...
+        *
         * XXX If a TCB does not exist, and the TH_SYN flag is
         * the only flag set, then create a session, mark it
         * as if it was LISTENING, and continue...
         */
-       if (so == 0) {
+        if (so == NULL) {
+          if (slirp->restricted) {
+            /* Any hostfwds will have an existing socket, so we only get here
+             * for non-hostfwd connections. These should be dropped, unless it
+             * happens to be a guestfwd.
+             */
+            for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
+                if (ex_ptr->ex_fport == ti->ti_dport &&
+                    ti->ti_dst.s_addr == ex_ptr->ex_addr.s_addr) {
+                    break;
+                }
+            }
+            if (!ex_ptr) {
+                goto dropwithreset;
+            }
+          }
+
          if ((tiflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK)) != TH_SYN)
            goto dropwithreset;
-               
-         if ((so = socreate()) == NULL)
+
+         if ((so = socreate(slirp)) == NULL)
            goto dropwithreset;
          if (tcp_attach(so) < 0) {
            free(so); /* Not sofree (if it failed, it's not insqued) */
            goto dropwithreset;
          }
-               
-         sbreserve(&so->so_snd, tcp_sndspace);
-         sbreserve(&so->so_rcv, tcp_rcvspace);
-         
-         /*            tcp_last_so = so; */  /* XXX ? */
-         /*            tp = sototcpcb(so);    */
-               
+
+         sbreserve(&so->so_snd, TCP_SNDSPACE);
+         sbreserve(&so->so_rcv, TCP_RCVSPACE);
+
          so->so_laddr = ti->ti_src;
          so->so_lport = ti->ti_sport;
          so->so_faddr = ti->ti_dst;
          so->so_fport = ti->ti_dport;
-               
+
          if ((so->so_iptos = tcp_tos(so)) == 0)
            so->so_iptos = ((struct ip *)ti)->ip_tos;
-               
+
          tp = sototcpcb(so);
          tp->t_state = TCPS_LISTEN;
        }
-           
+
         /*
          * If this is a still-connecting socket, this probably
          * a retransmit of the SYN.  Whether it's a retransmit SYN
@@ -432,40 +395,33 @@ findso:
                 goto drop;
 
        tp = sototcpcb(so);
-       
+
        /* XXX Should never fail */
-       if (tp == 0)
+        if (tp == NULL)
                goto dropwithreset;
        if (tp->t_state == TCPS_CLOSED)
                goto drop;
-       
-       /* Unscale the window into a 32-bit value. */
-/*     if ((tiflags & TH_SYN) == 0)
- *             tiwin = ti->ti_win << tp->snd_scale;
- *     else
- */
-               tiwin = ti->ti_win;
+
+       tiwin = ti->ti_win;
 
        /*
         * Segment received on connection.
         * Reset idle time and keep-alive timer.
         */
        tp->t_idle = 0;
-       if (so_options)
-          tp->t_timer[TCPT_KEEP] = tcp_keepintvl;
+       if (SO_OPTIONS)
+          tp->t_timer[TCPT_KEEP] = TCPTV_KEEPINTVL;
        else
-          tp->t_timer[TCPT_KEEP] = tcp_keepidle;
+          tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_IDLE;
 
        /*
         * Process options if not in LISTEN state,
         * else do it below (after getting remote address).
         */
        if (optp && tp->t_state != TCPS_LISTEN)
-               tcp_dooptions(tp, (u_char *)optp, optlen, ti); 
-/* , */
-/*                     &ts_present, &ts_val, &ts_ecr); */
+               tcp_dooptions(tp, (u_char *)optp, optlen, ti);
 
-       /* 
+       /*
         * Header prediction: check for the two common cases
         * of a uni-directional data xfer.  If the packet has
         * no control flags, is in-sequence, the window didn't
@@ -485,20 +441,9 @@ findso:
         */
        if (tp->t_state == TCPS_ESTABLISHED &&
            (tiflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK)) == TH_ACK &&
-/*         (!ts_present || TSTMP_GEQ(ts_val, tp->ts_recent)) && */
            ti->ti_seq == tp->rcv_nxt &&
            tiwin && tiwin == tp->snd_wnd &&
            tp->snd_nxt == tp->snd_max) {
-               /* 
-                * If last ACK falls within this segment's sequence numbers,
-                *  record the timestamp.
-                */
-/*             if (ts_present && SEQ_LEQ(ti->ti_seq, tp->last_ack_sent) &&
- *                SEQ_LT(tp->last_ack_sent, ti->ti_seq + ti->ti_len)) {
- *                     tp->ts_recent_age = tcp_now;
- *                     tp->ts_recent = ts_val;
- *             }
- */
                if (ti->ti_len == 0) {
                        if (SEQ_GT(ti->ti_ack, tp->snd_una) &&
                            SEQ_LEQ(ti->ti_ack, tp->snd_max) &&
@@ -506,19 +451,13 @@ findso:
                                /*
                                 * this is a pure ack for outstanding data.
                                 */
-                               ++tcpstat.tcps_predack;
-/*                             if (ts_present)
- *                                     tcp_xmit_timer(tp, tcp_now-ts_ecr+1);
- *                             else 
- */                                 if (tp->t_rtt &&
-                                           SEQ_GT(ti->ti_ack, tp->t_rtseq))
+                               if (tp->t_rtt &&
+                                   SEQ_GT(ti->ti_ack, tp->t_rtseq))
                                        tcp_xmit_timer(tp, tp->t_rtt);
                                acked = ti->ti_ack - tp->snd_una;
-                               tcpstat.tcps_rcvackpack++;
-                               tcpstat.tcps_rcvackbyte += acked;
                                sbdrop(&so->so_snd, acked);
                                tp->snd_una = ti->ti_ack;
-                               m_freem(m);
+                               m_free(m);
 
                                /*
                                 * If all outstanding data are acked, stop
@@ -534,14 +473,7 @@ findso:
                                else if (tp->t_timer[TCPT_PERSIST] == 0)
                                        tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
 
-                               /* 
-                                * There's room in so_snd, sowwakup will read()
-                                * from the socket if we can
-                                */
-/*                             if (so->so_snd.sb_flags & SB_NOTIFY)
- *                                     sowwakeup(so);
- */
-                               /* 
+                               /*
                                 * This is called because sowwakeup might have
                                 * put data into so_snd.  Since we don't so sowwakeup,
                                 * we don't need this.. XXX???
@@ -552,17 +484,14 @@ findso:
                                return;
                        }
                } else if (ti->ti_ack == tp->snd_una &&
-                   tp->seg_next == (tcpiphdrp_32)tp &&
+                   tcpfrag_list_empty(tp) &&
                    ti->ti_len <= sbspace(&so->so_rcv)) {
                        /*
                         * this is a pure, in-sequence data packet
                         * with nothing on the reassembly queue and
                         * we have enough buffer space to take it.
                         */
-                       ++tcpstat.tcps_preddat;
                        tp->rcv_nxt += ti->ti_len;
-                       tcpstat.tcps_rcvpack++;
-                       tcpstat.tcps_rcvbyte += ti->ti_len;
                        /*
                         * Add data to socket buffer.
                         */
@@ -570,41 +499,17 @@ findso:
                                if (tcp_emu(so,m)) sbappend(so, m);
                        } else
                                sbappend(so, m);
-                       
-                       /* 
-                        * XXX This is called when data arrives.  Later, check
-                        * if we can actually write() to the socket
-                        * XXX Need to check? It's be NON_BLOCKING
-                        */
-/*                     sorwakeup(so); */
-                       
+
                        /*
                         * If this is a short packet, then ACK now - with Nagel
                         *      congestion avoidance sender won't send more until
                         *      he gets an ACK.
-                        * 
-                        * Here are 3 interpretations of what should happen.
-                        * The best (for me) is to delay-ack everything except
-                        * if it's a one-byte packet containing an ESC
-                        * (this means it's an arrow key (or similar) sent using
-                        * Nagel, hence there will be no echo)
-                        * The first of these is the original, the second is the
-                        * middle ground between the other 2
-                        */ 
-/*                     if (((unsigned)ti->ti_len < tp->t_maxseg)) {
- */                         
-/*                     if (((unsigned)ti->ti_len < tp->t_maxseg && 
- *                          (so->so_iptos & IPTOS_LOWDELAY) == 0) ||
- *                         ((so->so_iptos & IPTOS_LOWDELAY) && 
- *                          ((struct tcpiphdr_2 *)ti)->first_char == (char)27)) {
- */
-                       if ((unsigned)ti->ti_len == 1 &&
-                           ((struct tcpiphdr_2 *)ti)->first_char == (char)27) {
-                               tp->t_flags |= TF_ACKNOW;
-                               tcp_output(tp);
-                       } else {
-                               tp->t_flags |= TF_DELACK;
-                       }
+                        *
+                        * It is better to not delay acks at all to maximize
+                        * TCP throughput.  See RFC 2581.
+                        */
+                       tp->t_flags |= TF_ACKNOW;
+                       tcp_output(tp);
                        return;
                }
        } /* header prediction */
@@ -644,54 +549,49 @@ findso:
            goto dropwithreset;
          if ((tiflags & TH_SYN) == 0)
            goto drop;
-               
+
          /*
           * This has way too many gotos...
           * But a bit of spaghetti code never hurt anybody :)
           */
-         
+
          /*
           * If this is destined for the control address, then flag to
           * tcp_ctl once connected, otherwise connect
           */
-         if ((so->so_faddr.s_addr&htonl(0xffffff00)) == special_addr.s_addr) {
-           int lastbyte=ntohl(so->so_faddr.s_addr) & 0xff;
-           if (lastbyte!=CTL_ALIAS && lastbyte!=CTL_DNS) {
-#if 0
-             if(lastbyte==CTL_CMD || lastbyte==CTL_EXEC) {
-               /* Command or exec adress */
-               so->so_state |= SS_CTL;
-             } else {
+         if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
+             slirp->vnetwork_addr.s_addr) {
+           if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr &&
+               so->so_faddr.s_addr != slirp->vnameserver_addr.s_addr) {
                /* May be an add exec */
-               struct ex_list *ex_ptr;
-
-               for(ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
-                 if(ex_ptr->ex_fport == so->so_fport && 
-                    lastbyte == ex_ptr->ex_addr) {
+               for (ex_ptr = slirp->exec_list; ex_ptr;
+                    ex_ptr = ex_ptr->ex_next) {
+                 if(ex_ptr->ex_fport == so->so_fport &&
+                    so->so_faddr.s_addr == ex_ptr->ex_addr.s_addr) {
                    so->so_state |= SS_CTL;
                    break;
                  }
                }
-             }
-             if(so->so_state & SS_CTL) goto cont_input;
-#endif
+               if (so->so_state & SS_CTL) {
+                   goto cont_input;
+               }
            }
            /* CTL_ALIAS: Do nothing, tcp_fconnect will be called on it */
          }
-         
+
          if (so->so_emu & EMU_NOCONNECT) {
            so->so_emu &= ~EMU_NOCONNECT;
            goto cont_input;
          }
-         
-         if(tcp_fconnect(so) == -1 && errno != EINPROGRESS) {
+
+         if((tcp_fconnect(so) == -1) && (errno != EINPROGRESS) && (errno != EWOULDBLOCK)) {
            u_char code=ICMP_UNREACH_NET;
-           DEBUG_MISC((dfd," tcp fconnect errno = %d-%s\n",
+           DEBUG_MISC((dfd, " tcp fconnect errno = %d-%s\n",
                        errno,strerror(errno)));
            if(errno == ECONNREFUSED) {
              /* ACK the SYN, send RST to refuse the connection */
              tcp_respond(tp, ti, m, ti->ti_seq+1, (tcp_seq)0,
-                         TH_RST|TH_ACK); 
+                         TH_RST|TH_ACK);
            } else {
              if(errno == EHOSTUNREACH) code=ICMP_UNREACH_HOST;
              HTONL(ti->ti_seq);             /* restore tcp header */
@@ -703,7 +603,7 @@ findso:
              *ip=save_ip;
              icmp_error(m, ICMP_UNREACH,code, 0,strerror(errno));
            }
-           tp = tcp_close(tp);
+            tcp_close(tp);
            m_free(m);
          } else {
            /*
@@ -716,40 +616,38 @@ findso:
            so->so_ti = ti;
            tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
            tp->t_state = TCPS_SYN_RECEIVED;
+           tcp_template(tp);
          }
          return;
 
-       cont_conn:     
-         /* m==NULL 
+       cont_conn:
+         /* m==NULL
           * Check if the connect succeeded
           */
          if (so->so_state & SS_NOFDREF) {
            tp = tcp_close(tp);
            goto dropwithreset;
          }
-       cont_input:             
+       cont_input:
          tcp_template(tp);
-         
+
          if (optp)
            tcp_dooptions(tp, (u_char *)optp, optlen, ti);
-         /* , */
-         /*                            &ts_present, &ts_val, &ts_ecr); */
-         
+
          if (iss)
            tp->iss = iss;
-         else 
-           tp->iss = tcp_iss;
-         tcp_iss += TCP_ISSINCR/2;
+         else
+           tp->iss = slirp->tcp_iss;
+         slirp->tcp_iss += TCP_ISSINCR/2;
          tp->irs = ti->ti_seq;
          tcp_sendseqinit(tp);
          tcp_rcvseqinit(tp);
          tp->t_flags |= TF_ACKNOW;
          tp->t_state = TCPS_SYN_RECEIVED;
          tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
-         tcpstat.tcps_accepts++;
          goto trimthenstep6;
        } /* case TCPS_LISTEN */
-       
+
        /*
         * If the state is SYN_SENT:
         *      if seg contains an ACK, but not for our SYN, drop the input.
@@ -769,8 +667,9 @@ findso:
                        goto dropwithreset;
 
                if (tiflags & TH_RST) {
-                       if (tiflags & TH_ACK)
-                               tp = tcp_drop(tp,0); /* XXX Check t_softerror! */
+                        if (tiflags & TH_ACK) {
+                                tcp_drop(tp, 0); /* XXX Check t_softerror! */
+                        }
                        goto drop;
                }
 
@@ -787,17 +686,9 @@ findso:
                tcp_rcvseqinit(tp);
                tp->t_flags |= TF_ACKNOW;
                if (tiflags & TH_ACK && SEQ_GT(tp->snd_una, tp->iss)) {
-                       tcpstat.tcps_connects++;
                        soisfconnected(so);
                        tp->t_state = TCPS_ESTABLISHED;
-                       
-                       /* Do window scaling on this connection? */
-/*                     if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) ==
- *                             (TF_RCVD_SCALE|TF_REQ_SCALE)) {
- *                             tp->snd_scale = tp->requested_s_scale;
- *                             tp->rcv_scale = tp->request_r_scale;
- *                     }
- */
+
                        (void) tcp_reass(tp, (struct tcpiphdr *)0,
                                (struct mbuf *)0);
                        /*
@@ -821,8 +712,6 @@ trimthenstep6:
                        m_adj(m, -todrop);
                        ti->ti_len = tp->rcv_wnd;
                        tiflags &= ~TH_FIN;
-                       tcpstat.tcps_rcvpackafterwin++;
-                       tcpstat.tcps_rcvbyteafterwin += todrop;
                }
                tp->snd_wl1 = ti->ti_seq - 1;
                tp->rcv_up = ti->ti_seq;
@@ -830,46 +719,16 @@ trimthenstep6:
        } /* switch tp->t_state */
        /*
         * States other than LISTEN or SYN_SENT.
-        * First check timestamp, if present.
-        * Then check that at least some bytes of segment are within 
+        * Check that at least some bytes of segment are within
         * receive window.  If segment begins before rcv_nxt,
         * drop leading data (and SYN); if nothing left, just ack.
-        * 
-        * RFC 1323 PAWS: If we have a timestamp reply on this segment
-        * and it's less than ts_recent, drop it.
         */
-/*     if (ts_present && (tiflags & TH_RST) == 0 && tp->ts_recent &&
- *         TSTMP_LT(ts_val, tp->ts_recent)) {
- *
- */            /* Check to see if ts_recent is over 24 days old.  */
-/*             if ((int)(tcp_now - tp->ts_recent_age) > TCP_PAWS_IDLE) {
- */                    /*
- *                      * Invalidate ts_recent.  If this segment updates
- *                      * ts_recent, the age will be reset later and ts_recent
- *                      * will get a valid value.  If it does not, setting
- *                      * ts_recent to zero will at least satisfy the
- *                      * requirement that zero be placed in the timestamp
- *                      * echo reply when ts_recent isn't valid.  The
- *                      * age isn't reset until we get a valid ts_recent
- *                      * because we don't want out-of-order segments to be
- *                      * dropped when ts_recent is old.
- *                      */
-/*                     tp->ts_recent = 0;
- *             } else {
- *                     tcpstat.tcps_rcvduppack++;
- *                     tcpstat.tcps_rcvdupbyte += ti->ti_len;
- *                     tcpstat.tcps_pawsdrop++;
- *                     goto dropafterack;
- *             }
- *     }
- */
-
        todrop = tp->rcv_nxt - ti->ti_seq;
        if (todrop > 0) {
                if (tiflags & TH_SYN) {
                        tiflags &= ~TH_SYN;
                        ti->ti_seq++;
-                       if (ti->ti_urp > 1) 
+                       if (ti->ti_urp > 1)
                                ti->ti_urp--;
                        else
                                tiflags &= ~TH_URG;
@@ -886,18 +745,13 @@ trimthenstep6:
                         * of sequence; drop it.
                         */
                        tiflags &= ~TH_FIN;
-                       
+
                        /*
                         * Send an ACK to resynchronize and drop any data.
                         * But keep on processing for RST or ACK.
                         */
                        tp->t_flags |= TF_ACKNOW;
                        todrop = ti->ti_len;
-                       tcpstat.tcps_rcvduppack++;
-                       tcpstat.tcps_rcvdupbyte += todrop;
-               } else {
-                       tcpstat.tcps_rcvpartduppack++;
-                       tcpstat.tcps_rcvpartdupbyte += todrop;
                }
                m_adj(m, todrop);
                ti->ti_seq += todrop;
@@ -916,7 +770,6 @@ trimthenstep6:
        if ((so->so_state & SS_NOFDREF) &&
            tp->t_state > TCPS_CLOSE_WAIT && ti->ti_len) {
                tp = tcp_close(tp);
-               tcpstat.tcps_rcvafterclose++;
                goto dropwithreset;
        }
 
@@ -926,9 +779,7 @@ trimthenstep6:
         */
        todrop = (ti->ti_seq+ti->ti_len) - (tp->rcv_nxt+tp->rcv_wnd);
        if (todrop > 0) {
-               tcpstat.tcps_rcvpackafterwin++;
                if (todrop >= ti->ti_len) {
-                       tcpstat.tcps_rcvbyteafterwin += ti->ti_len;
                        /*
                         * If a new connection request is received
                         * while in TIME_WAIT, drop the old connection
@@ -951,28 +802,15 @@ trimthenstep6:
                         */
                        if (tp->rcv_wnd == 0 && ti->ti_seq == tp->rcv_nxt) {
                                tp->t_flags |= TF_ACKNOW;
-                               tcpstat.tcps_rcvwinprobe++;
-                       } else
+                       } else {
                                goto dropafterack;
-               } else
-                       tcpstat.tcps_rcvbyteafterwin += todrop;
+                       }
+               }
                m_adj(m, -todrop);
                ti->ti_len -= todrop;
                tiflags &= ~(TH_PUSH|TH_FIN);
        }
 
-       /*
-        * If last ACK falls within this segment's sequence numbers,
-        * record its timestamp.
-        */
-/*     if (ts_present && SEQ_LEQ(ti->ti_seq, tp->last_ack_sent) &&
- *         SEQ_LT(tp->last_ack_sent, ti->ti_seq + ti->ti_len +
- *                ((tiflags & (TH_SYN|TH_FIN)) != 0))) {
- *             tp->ts_recent_age = tcp_now;
- *             tp->ts_recent = ts_val;
- *     }
- */
-
        /*
         * If the RST bit is set examine the state:
         *    SYN_RECEIVED STATE:
@@ -986,24 +824,18 @@ trimthenstep6:
        if (tiflags&TH_RST) switch (tp->t_state) {
 
        case TCPS_SYN_RECEIVED:
-/*             so->so_error = ECONNREFUSED; */
-               goto close;
-
        case TCPS_ESTABLISHED:
        case TCPS_FIN_WAIT_1:
        case TCPS_FIN_WAIT_2:
        case TCPS_CLOSE_WAIT:
-/*             so->so_error = ECONNRESET; */
-       close:
                tp->t_state = TCPS_CLOSED;
-               tcpstat.tcps_drops++;
-               tp = tcp_close(tp);
+                tcp_close(tp);
                goto drop;
 
        case TCPS_CLOSING:
        case TCPS_LAST_ACK:
        case TCPS_TIME_WAIT:
-               tp = tcp_close(tp);
+                tcp_close(tp);
                goto drop;
        }
 
@@ -1035,14 +867,13 @@ trimthenstep6:
                if (SEQ_GT(tp->snd_una, ti->ti_ack) ||
                    SEQ_GT(ti->ti_ack, tp->snd_max))
                        goto dropwithreset;
-               tcpstat.tcps_connects++;
                tp->t_state = TCPS_ESTABLISHED;
-               /* 
-                * The sent SYN is ack'ed with our sequence number +1 
-                * The first data byte already in the buffer will get 
+               /*
+                * The sent SYN is ack'ed with our sequence number +1
+                * The first data byte already in the buffer will get
                 * lost if no correction is made.  This is only needed for
                 * SS_CTL since the buffer is empty otherwise.
-                * tp->snd_una++; or:     
+                * tp->snd_una++; or:
                 */
                tp->snd_una=ti->ti_ack;
                if (so->so_state & SS_CTL) {
@@ -1052,7 +883,8 @@ trimthenstep6:
                    soisfconnected(so);
                    so->so_state &= ~SS_CTL;   /* success XXX */
                  } else if (ret == 2) {
-                   so->so_state = SS_NOFDREF; /* CTL_CMD */
+                   so->so_state &= SS_PERSISTENT_MASK;
+                   so->so_state |= SS_NOFDREF; /* CTL_CMD */
                  } else {
                    needoutput = 1;
                    tp->t_state = TCPS_FIN_WAIT_1;
@@ -1060,14 +892,7 @@ trimthenstep6:
                } else {
                  soisfconnected(so);
                }
-               
-               /* Do window scaling? */
-/*             if ((tp->t_flags & (TF_RCVD_SCALE|TF_REQ_SCALE)) ==
- *                     (TF_RCVD_SCALE|TF_REQ_SCALE)) {
- *                     tp->snd_scale = tp->requested_s_scale;
- *                     tp->rcv_scale = tp->request_r_scale;
- *             }
- */
+
                (void) tcp_reass(tp, (struct tcpiphdr *)0, (struct mbuf *)0);
                tp->snd_wl1 = ti->ti_seq - 1;
                /* Avoid ack processing; snd_una==ti_ack  =>  dup ack */
@@ -1092,8 +917,7 @@ trimthenstep6:
 
                if (SEQ_LEQ(ti->ti_ack, tp->snd_una)) {
                        if (ti->ti_len == 0 && tiwin == tp->snd_wnd) {
-                         tcpstat.tcps_rcvdupack++;
-                         DEBUG_MISC((dfd," dup ack  m = %lx  so = %lx \n",
+                         DEBUG_MISC((dfd, " dup ack  m = %lx  so = %lx\n",
                                      (long )m, (long )so));
                                /*
                                 * If we have outstanding data (other than
@@ -1114,7 +938,7 @@ trimthenstep6:
                                 * the new ssthresh).
                                 *
                                 * Dup acks mean that packets have left the
-                                * network (they're now cached at the receiver) 
+                                * network (they're now cached at the receiver)
                                 * so bump cwnd by the amount in the receiver
                                 * to keep a constant cwnd packets in the
                                 * network.
@@ -1122,7 +946,7 @@ trimthenstep6:
                                if (tp->t_timer[TCPT_REXMT] == 0 ||
                                    ti->ti_ack != tp->snd_una)
                                        tp->t_dupacks = 0;
-                               else if (++tp->t_dupacks == tcprexmtthresh) {
+                               else if (++tp->t_dupacks == TCPREXMTTHRESH) {
                                        tcp_seq onxt = tp->snd_nxt;
                                        u_int win =
                                            min(tp->snd_wnd, tp->snd_cwnd) / 2 /
@@ -1141,7 +965,7 @@ trimthenstep6:
                                        if (SEQ_GT(onxt, tp->snd_nxt))
                                                tp->snd_nxt = onxt;
                                        goto drop;
-                               } else if (tp->t_dupacks > tcprexmtthresh) {
+                               } else if (tp->t_dupacks > TCPREXMTTHRESH) {
                                        tp->snd_cwnd += tp->t_maxseg;
                                        (void) tcp_output(tp);
                                        goto drop;
@@ -1155,32 +979,23 @@ trimthenstep6:
                 * If the congestion window was inflated to account
                 * for the other side's cached packets, retract it.
                 */
-               if (tp->t_dupacks > tcprexmtthresh &&
+               if (tp->t_dupacks > TCPREXMTTHRESH &&
                    tp->snd_cwnd > tp->snd_ssthresh)
                        tp->snd_cwnd = tp->snd_ssthresh;
                tp->t_dupacks = 0;
                if (SEQ_GT(ti->ti_ack, tp->snd_max)) {
-                       tcpstat.tcps_rcvacktoomuch++;
                        goto dropafterack;
                }
                acked = ti->ti_ack - tp->snd_una;
-               tcpstat.tcps_rcvackpack++;
-               tcpstat.tcps_rcvackbyte += acked;
 
                /*
-                * If we have a timestamp reply, update smoothed
-                * round trip time.  If no timestamp is present but
-                * transmit timer is running and timed sequence
+                * If transmit timer is running and timed sequence
                 * number was acked, update smoothed round trip time.
                 * Since we now have an rtt measurement, cancel the
                 * timer backoff (cf., Phil Karn's retransmit alg.).
                 * Recompute the initial retransmit timer.
                 */
-/*             if (ts_present)
- *                     tcp_xmit_timer(tp, tcp_now-ts_ecr+1);
- *             else
- */                 
-                    if (tp->t_rtt && SEQ_GT(ti->ti_ack, tp->t_rtseq))
+               if (tp->t_rtt && SEQ_GT(ti->ti_ack, tp->t_rtseq))
                        tcp_xmit_timer(tp,tp->t_rtt);
 
                /*
@@ -1218,13 +1033,6 @@ trimthenstep6:
                        tp->snd_wnd -= acked;
                        ourfinisacked = 0;
                }
-               /*
-                * XXX sowwakup is called when data is acked and there's room for
-                * for more data... it should read() the socket 
-                */
-/*             if (so->so_snd.sb_flags & SB_NOTIFY)
- *                     sowwakeup(so);
- */
                tp->snd_una = ti->ti_ack;
                if (SEQ_LT(tp->snd_nxt, tp->snd_una))
                        tp->snd_nxt = tp->snd_una;
@@ -1246,8 +1054,7 @@ trimthenstep6:
                                 * we'll hang forever.
                                 */
                                if (so->so_state & SS_FCANTRCVMORE) {
-                                       soisfdisconnected(so);
-                                       tp->t_timer[TCPT_2MSL] = tcp_maxidle;
+                                       tp->t_timer[TCPT_2MSL] = TCP_MAXIDLE;
                                }
                                tp->t_state = TCPS_FIN_WAIT_2;
                        }
@@ -1264,7 +1071,6 @@ trimthenstep6:
                                tp->t_state = TCPS_TIME_WAIT;
                                tcp_canceltimers(tp);
                                tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
-                               soisfdisconnected(so);
                        }
                        break;
 
@@ -1276,7 +1082,7 @@ trimthenstep6:
                 */
                case TCPS_LAST_ACK:
                        if (ourfinisacked) {
-                               tp = tcp_close(tp);
+                                tcp_close(tp);
                                goto drop;
                        }
                        break;
@@ -1298,13 +1104,9 @@ step6:
         * Don't look at window if no ACK: TAC's send garbage on first SYN.
         */
        if ((tiflags & TH_ACK) &&
-           (SEQ_LT(tp->snd_wl1, ti->ti_seq) || 
+           (SEQ_LT(tp->snd_wl1, ti->ti_seq) ||
            (tp->snd_wl1 == ti->ti_seq && (SEQ_LT(tp->snd_wl2, ti->ti_ack) ||
            (tp->snd_wl2 == ti->ti_ack && tiwin > tp->snd_wnd))))) {
-               /* keep track of pure window updates */
-               if (ti->ti_len == 0 &&
-                   tp->snd_wl2 == ti->ti_ack && tiwin > tp->snd_wnd)
-                       tcpstat.tcps_rcvwinupd++;
                tp->snd_wnd = tiwin;
                tp->snd_wl1 = ti->ti_seq;
                tp->snd_wl2 = ti->ti_ack;
@@ -1333,14 +1135,14 @@ step6:
                 * If this segment advances the known urgent pointer,
                 * then mark the data stream.  This should not happen
                 * in CLOSE_WAIT, CLOSING, LAST_ACK or TIME_WAIT STATES since
-                * a FIN has been received from the remote side. 
+                * a FIN has been received from the remote side.
                 * In these states we ignore the URG.
                 *
                 * According to RFC961 (Assigned Protocols),
                 * the urgent pointer points to the last octet
                 * of urgent data.  We continue, however,
                 * to consider it to indicate the first octet
-                * of data past the urgent section as the original 
+                * of data past the urgent section as the original
                 * spec states (in one of two places).
                 */
                if (SEQ_GT(ti->ti_seq+ti->ti_urp, tp->rcv_up)) {
@@ -1348,7 +1150,7 @@ step6:
                        so->so_urgc =  so->so_rcv.sb_cc +
                                (tp->rcv_up - tp->rcv_nxt); /* -1; */
                        tp->rcv_up = ti->ti_seq + ti->ti_urp;
-        
+
                }
        } else
                /*
@@ -1360,6 +1162,16 @@ step6:
                        tp->rcv_up = tp->rcv_nxt;
 dodata:
 
+       /*
+        * If this is a small packet, then ACK now - with Nagel
+        *      congestion avoidance sender won't send more until
+        *      he gets an ACK.
+        */
+       if (ti->ti_len && (unsigned)ti->ti_len <= 5 &&
+           ((struct tcpiphdr_2 *)ti)->first_char == (char)27) {
+               tp->t_flags |= TF_ACKNOW;
+       }
+
        /*
         * Process the segment text, merging it into the TCP sequencing queue,
         * and arranging for acknowledgment of receipt if necessary.
@@ -1371,12 +1183,6 @@ dodata:
        if ((ti->ti_len || (tiflags&TH_FIN)) &&
            TCPS_HAVERCVDFIN(tp->t_state) == 0) {
                TCP_REASS(tp, ti, m, so, tiflags);
-               /*
-                * Note the amount of data that peer has sent into
-                * our window, in order to estimate the sender's
-                * buffer size.
-                */
-               len = so->so_rcv.sb_datalen - (tp->rcv_adv - tp->rcv_nxt);
        } else {
                m_free(m);
                tiflags &= ~TH_FIN;
@@ -1397,9 +1203,8 @@ dodata:
                         * will got to TCPS_LAST_ACK, and use tcp_output()
                         * to send the FIN.
                         */
-/*                     sofcantrcvmore(so); */
                        sofwdrain(so);
-                       
+
                        tp->t_flags |= TF_ACKNOW;
                        tp->rcv_nxt++;
                }
@@ -1413,7 +1218,7 @@ dodata:
                case TCPS_ESTABLISHED:
                  if(so->so_emu == EMU_CTL)        /* no shutdown on socket */
                    tp->t_state = TCPS_LAST_ACK;
-                 else 
+                 else
                    tp->t_state = TCPS_CLOSE_WAIT;
                  break;
 
@@ -1427,14 +1232,13 @@ dodata:
 
                /*
                 * In FIN_WAIT_2 state enter the TIME_WAIT state,
-                * starting the time-wait timer, turning off the other 
+                * starting the time-wait timer, turning off the other
                 * standard timers.
                 */
                case TCPS_FIN_WAIT_2:
                        tp->t_state = TCPS_TIME_WAIT;
                        tcp_canceltimers(tp);
                        tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL;
-                       soisfdisconnected(so);
                        break;
 
                /*
@@ -1446,25 +1250,6 @@ dodata:
                }
        }
 
-       /*
-        * If this is a small packet, then ACK now - with Nagel
-        *      congestion avoidance sender won't send more until
-        *      he gets an ACK.
-        * 
-        * See above.
-        */
-/*     if (ti->ti_len && (unsigned)ti->ti_len < tp->t_maxseg) {
- */
-/*     if ((ti->ti_len && (unsigned)ti->ti_len < tp->t_maxseg &&
- *             (so->so_iptos & IPTOS_LOWDELAY) == 0) ||
- *            ((so->so_iptos & IPTOS_LOWDELAY) &&
- *            ((struct tcpiphdr_2 *)ti)->first_char == (char)27)) {
- */
-       if (ti->ti_len && (unsigned)ti->ti_len <= 5 &&
-           ((struct tcpiphdr_2 *)ti)->first_char == (char)27) {
-               tp->t_flags |= TF_ACKNOW;
-       }
-
        /*
         * Return any desired output.
         */
@@ -1480,7 +1265,7 @@ dropafterack:
         */
        if (tiflags & TH_RST)
                goto drop;
-       m_freem(m);
+       m_free(m);
        tp->t_flags |= TF_ACKNOW;
        (void) tcp_output(tp);
        return;
@@ -1502,26 +1287,16 @@ drop:
         * Drop space held by incoming segment and return.
         */
        m_free(m);
-
-       return;
 }
 
- /* , ts_present, ts_val, ts_ecr) */
-/*     int *ts_present;
- *     u_int32_t *ts_val, *ts_ecr;
- */
-void
-tcp_dooptions(tp, cp, cnt, ti)
-       struct tcpcb *tp;
-       u_char *cp;
-       int cnt;
-       struct tcpiphdr *ti;
+static void
+tcp_dooptions(struct tcpcb *tp, u_char *cp, int cnt, struct tcpiphdr *ti)
 {
-       u_int16_t mss;
+       uint16_t mss;
        int opt, optlen;
 
        DEBUG_CALL("tcp_dooptions");
-       DEBUG_ARGS((dfd," tp = %lx  cnt=%i \n", (long )tp, cnt));
+       DEBUG_ARGS((dfd, " tp = %lx  cnt=%i\n", (long)tp, cnt));
 
        for (; cnt > 0; cnt -= optlen, cp += optlen) {
                opt = cp[0];
@@ -1548,35 +1323,6 @@ tcp_dooptions(tp, cp, cnt, ti)
                        NTOHS(mss);
                        (void) tcp_mss(tp, mss);        /* sets t_maxseg */
                        break;
-
-/*             case TCPOPT_WINDOW:
- *                     if (optlen != TCPOLEN_WINDOW)
- *                             continue;
- *                     if (!(ti->ti_flags & TH_SYN))
- *                             continue;
- *                     tp->t_flags |= TF_RCVD_SCALE;
- *                     tp->requested_s_scale = min(cp[2], TCP_MAX_WINSHIFT);
- *                     break;
- */
-/*             case TCPOPT_TIMESTAMP:
- *                     if (optlen != TCPOLEN_TIMESTAMP)
- *                             continue;
- *                     *ts_present = 1;
- *                     memcpy((char *) ts_val, (char *)cp + 2, sizeof(*ts_val));
- *                     NTOHL(*ts_val);
- *                     memcpy((char *) ts_ecr, (char *)cp + 6, sizeof(*ts_ecr));
- *                     NTOHL(*ts_ecr);
- *
- */                    /* 
- *                      * A timestamp received in a SYN makes
- *                      * it ok to send timestamp requests and replies.
- *                      */
-/*                     if (ti->ti_flags & TH_SYN) {
- *                             tp->t_flags |= TF_RCVD_TSTMP;
- *                             tp->ts_recent = *ts_val;
- *                             tp->ts_recent_age = tcp_now;
- *                     }
- */                    break;
                }
        }
 }
@@ -1598,7 +1344,7 @@ tcp_pulloutofband(so, ti, m)
        register struct mbuf *m;
 {
        int cnt = ti->ti_urp - 1;
-       
+
        while (cnt >= 0) {
                if (m->m_len > cnt) {
                        char *cp = mtod(m, caddr_t) + cnt;
@@ -1625,18 +1371,15 @@ tcp_pulloutofband(so, ti, m)
  * and update averages and current timeout.
  */
 
-void
-tcp_xmit_timer(tp, rtt)
-       register struct tcpcb *tp;
-       int rtt;
+static void
+tcp_xmit_timer(register struct tcpcb *tp, int rtt)
 {
        register short delta;
 
        DEBUG_CALL("tcp_xmit_timer");
        DEBUG_ARG("tp = %lx", (long)tp);
        DEBUG_ARG("rtt = %d", rtt);
-       
-       tcpstat.tcps_rttupdated++;
+
        if (tp->t_srtt != 0) {
                /*
                 * srtt is stored as fixed point with 3 bits after the
@@ -1664,7 +1407,7 @@ tcp_xmit_timer(tp, rtt)
                if ((tp->t_rttvar += delta) <= 0)
                        tp->t_rttvar = 1;
        } else {
-               /* 
+               /*
                 * No rtt measurement yet - use the unsmoothed rtt.
                 * Set the variance to half the rtt (so our first
                 * retransmit happens at 3*rtt).
@@ -1688,7 +1431,7 @@ tcp_xmit_timer(tp, rtt)
         */
        TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
            (short)tp->t_rttmin, TCPTV_REXMTMAX); /* XXX */
-       
+
        /*
         * We received an ack for a packet that wasn't retransmitted;
         * it is probably safe to discard any error indications we've
@@ -1716,30 +1459,32 @@ tcp_xmit_timer(tp, rtt)
  */
 
 int
-tcp_mss(tp, offer)
-        register struct tcpcb *tp;
-        u_int offer;
+tcp_mss(struct tcpcb *tp, u_int offer)
 {
        struct socket *so = tp->t_socket;
        int mss;
-       
+
        DEBUG_CALL("tcp_mss");
        DEBUG_ARG("tp = %lx", (long)tp);
        DEBUG_ARG("offer = %d", offer);
-       
-       mss = min(if_mtu, if_mru) - sizeof(struct tcpiphdr);
+
+       mss = min(IF_MTU, IF_MRU) - sizeof(struct tcpiphdr);
        if (offer)
                mss = min(mss, offer);
        mss = max(mss, 32);
        if (mss < tp->t_maxseg || offer != 0)
           tp->t_maxseg = mss;
-       
+
        tp->snd_cwnd = mss;
-       
-       sbreserve(&so->so_snd, tcp_sndspace+((tcp_sndspace%mss)?(mss-(tcp_sndspace%mss)):0));
-       sbreserve(&so->so_rcv, tcp_rcvspace+((tcp_rcvspace%mss)?(mss-(tcp_rcvspace%mss)):0));
-       
+
+       sbreserve(&so->so_snd, TCP_SNDSPACE + ((TCP_SNDSPACE % mss) ?
+                                               (mss - (TCP_SNDSPACE % mss)) :
+                                               0));
+       sbreserve(&so->so_rcv, TCP_RCVSPACE + ((TCP_RCVSPACE % mss) ?
+                                               (mss - (TCP_RCVSPACE % mss)) :
+                                               0));
+
        DEBUG_MISC((dfd, " returning mss = %d\n", mss));
-       
+
        return mss;
 }