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-rw-r--r--slirp/src/tcp_subr.c987
1 files changed, 0 insertions, 987 deletions
diff --git a/slirp/src/tcp_subr.c b/slirp/src/tcp_subr.c
deleted file mode 100644
index fde9207b0c..0000000000
--- a/slirp/src/tcp_subr.c
+++ /dev/null
@@ -1,987 +0,0 @@
-/* SPDX-License-Identifier: BSD-3-Clause */
-/*
- * Copyright (c) 1982, 1986, 1988, 1990, 1993
- *	The Regents of the University of California.  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 University 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 REGENTS 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 REGENTS 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.
- *
- *	@(#)tcp_subr.c	8.1 (Berkeley) 6/10/93
- * tcp_subr.c,v 1.5 1994/10/08 22:39:58 phk Exp
- */
-
-/*
- * Changes and additions relating to SLiRP
- * Copyright (c) 1995 Danny Gasparovski.
- */
-
-#include "slirp.h"
-
-/* patchable/settable parameters for tcp */
-/* Don't do rfc1323 performance enhancements */
-#define TCP_DO_RFC1323 0
-
-/*
- * Tcp initialization
- */
-void
-tcp_init(Slirp *slirp)
-{
-    slirp->tcp_iss = 1;		/* wrong */
-    slirp->tcb.so_next = slirp->tcb.so_prev = &slirp->tcb;
-    slirp->tcp_last_so = &slirp->tcb;
-}
-
-void tcp_cleanup(Slirp *slirp)
-{
-    while (slirp->tcb.so_next != &slirp->tcb) {
-        tcp_close(sototcpcb(slirp->tcb.so_next));
-    }
-}
-
-/*
- * Create template to be used to send tcp packets on a connection.
- * Call after host entry created, fills
- * in a skeletal tcp/ip header, minimizing the amount of work
- * necessary when the connection is used.
- */
-void
-tcp_template(struct tcpcb *tp)
-{
-	struct socket *so = tp->t_socket;
-	register struct tcpiphdr *n = &tp->t_template;
-
-	n->ti_mbuf = NULL;
-	memset(&n->ti, 0, sizeof(n->ti));
-	n->ti_x0 = 0;
-	switch (so->so_ffamily) {
-	case AF_INET:
-	    n->ti_pr = IPPROTO_TCP;
-	    n->ti_len = htons(sizeof(struct tcphdr));
-	    n->ti_src = so->so_faddr;
-	    n->ti_dst = so->so_laddr;
-	    n->ti_sport = so->so_fport;
-	    n->ti_dport = so->so_lport;
-	    break;
-
-	case AF_INET6:
-	    n->ti_nh6 = IPPROTO_TCP;
-	    n->ti_len = htons(sizeof(struct tcphdr));
-	    n->ti_src6 = so->so_faddr6;
-	    n->ti_dst6 = so->so_laddr6;
-	    n->ti_sport = so->so_fport6;
-	    n->ti_dport = so->so_lport6;
-	    break;
-
-	default:
-	    g_assert_not_reached();
-	}
-
-	n->ti_seq = 0;
-	n->ti_ack = 0;
-	n->ti_x2 = 0;
-	n->ti_off = 5;
-	n->ti_flags = 0;
-	n->ti_win = 0;
-	n->ti_sum = 0;
-	n->ti_urp = 0;
-}
-
-/*
- * Send a single message to the TCP at address specified by
- * the given TCP/IP header.  If m == 0, then we make a copy
- * of the tcpiphdr at ti and send directly to the addressed host.
- * This is used to force keep alive messages out using the TCP
- * template for a connection tp->t_template.  If flags are given
- * then we send a message back to the TCP which originated the
- * segment ti, and discard the mbuf containing it and any other
- * attached mbufs.
- *
- * In any case the ack and sequence number of the transmitted
- * segment are as specified by the parameters.
- */
-void
-tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
-            tcp_seq ack, tcp_seq seq, int flags, unsigned short af)
-{
-	register int tlen;
-	int win = 0;
-
-	DEBUG_CALL("tcp_respond");
-	DEBUG_ARG("tp = %p", tp);
-	DEBUG_ARG("ti = %p", ti);
-	DEBUG_ARG("m = %p", m);
-	DEBUG_ARG("ack = %u", ack);
-	DEBUG_ARG("seq = %u", seq);
-	DEBUG_ARG("flags = %x", flags);
-
-	if (tp)
-		win = sbspace(&tp->t_socket->so_rcv);
-        if (m == NULL) {
-		if (!tp || (m = m_get(tp->t_socket->slirp)) == NULL)
-			return;
-		tlen = 0;
-		m->m_data += IF_MAXLINKHDR;
-		*mtod(m, struct tcpiphdr *) = *ti;
-		ti = mtod(m, struct tcpiphdr *);
-		switch (af) {
-		case AF_INET:
-		    ti->ti.ti_i4.ih_x1 = 0;
-		    break;
-		case AF_INET6:
-		    ti->ti.ti_i6.ih_x1 = 0;
-		    break;
-		default:
-		    g_assert_not_reached();
-		}
-		flags = TH_ACK;
-	} else {
-		/*
-		 * ti points into m so the next line is just making
-		 * the mbuf point to ti
-		 */
-		m->m_data = (char *)ti;
-
-		m->m_len = sizeof (struct tcpiphdr);
-		tlen = 0;
-#define xchg(a,b,type) { type t; t=a; a=b; b=t; }
-		switch (af) {
-		case AF_INET:
-		    xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, uint32_t);
-		    xchg(ti->ti_dport, ti->ti_sport, uint16_t);
-		    break;
-		case AF_INET6:
-		    xchg(ti->ti_dst6, ti->ti_src6, struct in6_addr);
-		    xchg(ti->ti_dport, ti->ti_sport, uint16_t);
-		    break;
-		default:
-		    g_assert_not_reached();
-		}
-#undef xchg
-	}
-	ti->ti_len = htons((uint16_t)(sizeof (struct tcphdr) + tlen));
-	tlen += sizeof (struct tcpiphdr);
-	m->m_len = tlen;
-
-	ti->ti_mbuf = NULL;
-	ti->ti_x0 = 0;
-	ti->ti_seq = htonl(seq);
-	ti->ti_ack = htonl(ack);
-	ti->ti_x2 = 0;
-	ti->ti_off = sizeof (struct tcphdr) >> 2;
-	ti->ti_flags = flags;
-	if (tp)
-		ti->ti_win = htons((uint16_t) (win >> tp->rcv_scale));
-	else
-		ti->ti_win = htons((uint16_t)win);
-	ti->ti_urp = 0;
-	ti->ti_sum = 0;
-	ti->ti_sum = cksum(m, tlen);
-
-	struct tcpiphdr tcpiph_save = *(mtod(m, struct tcpiphdr *));
-	struct ip *ip;
-	struct ip6 *ip6;
-
-	switch (af) {
-	case AF_INET:
-	    m->m_data += sizeof(struct tcpiphdr) - sizeof(struct tcphdr)
-	                                         - sizeof(struct ip);
-	    m->m_len  -= sizeof(struct tcpiphdr) - sizeof(struct tcphdr)
-	                                         - sizeof(struct ip);
-	    ip = mtod(m, struct ip *);
-	    ip->ip_len = m->m_len;
-	    ip->ip_dst = tcpiph_save.ti_dst;
-	    ip->ip_src = tcpiph_save.ti_src;
-	    ip->ip_p = tcpiph_save.ti_pr;
-
-	    if (flags & TH_RST) {
-	        ip->ip_ttl = MAXTTL;
-	    } else {
-	        ip->ip_ttl = IPDEFTTL;
-	    }
-
-	    ip_output(NULL, m);
-	    break;
-
-	case AF_INET6:
-	    m->m_data += sizeof(struct tcpiphdr) - sizeof(struct tcphdr)
-	                                         - sizeof(struct ip6);
-	    m->m_len  -= sizeof(struct tcpiphdr) - sizeof(struct tcphdr)
-	                                         - sizeof(struct ip6);
-	    ip6 = mtod(m, struct ip6 *);
-	    ip6->ip_pl = tcpiph_save.ti_len;
-	    ip6->ip_dst = tcpiph_save.ti_dst6;
-	    ip6->ip_src = tcpiph_save.ti_src6;
-	    ip6->ip_nh = tcpiph_save.ti_nh6;
-
-	    ip6_output(NULL, m, 0);
-	    break;
-
-	default:
-	    g_assert_not_reached();
-	}
-}
-
-/*
- * Create a new TCP control block, making an
- * empty reassembly queue and hooking it to the argument
- * protocol control block.
- */
-struct tcpcb *
-tcp_newtcpcb(struct socket *so)
-{
-	register struct tcpcb *tp;
-
-	tp = (struct tcpcb *)malloc(sizeof(*tp));
-	if (tp == NULL)
-		return ((struct tcpcb *)0);
-
-	memset((char *) tp, 0, sizeof(struct tcpcb));
-	tp->seg_next = tp->seg_prev = (struct tcpiphdr*)tp;
-	tp->t_maxseg = (so->so_ffamily == AF_INET) ? TCP_MSS : TCP6_MSS;
-
-	tp->t_flags = TCP_DO_RFC1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0;
-	tp->t_socket = so;
-
-	/*
-	 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
-	 * rtt estimate.  Set rttvar so that srtt + 2 * rttvar gives
-	 * reasonable initial retransmit time.
-	 */
-	tp->t_srtt = TCPTV_SRTTBASE;
-	tp->t_rttvar = TCPTV_SRTTDFLT << 2;
-	tp->t_rttmin = TCPTV_MIN;
-
-	TCPT_RANGESET(tp->t_rxtcur,
-	    ((TCPTV_SRTTBASE >> 2) + (TCPTV_SRTTDFLT << 2)) >> 1,
-	    TCPTV_MIN, TCPTV_REXMTMAX);
-
-	tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
-	tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
-	tp->t_state = TCPS_CLOSED;
-
-	so->so_tcpcb = tp;
-
-	return (tp);
-}
-
-/*
- * Drop a TCP connection, reporting
- * the specified error.  If connection is synchronized,
- * then send a RST to peer.
- */
-struct tcpcb *tcp_drop(struct tcpcb *tp, int err)
-{
-	DEBUG_CALL("tcp_drop");
-	DEBUG_ARG("tp = %p", tp);
-	DEBUG_ARG("errno = %d", errno);
-
-	if (TCPS_HAVERCVDSYN(tp->t_state)) {
-		tp->t_state = TCPS_CLOSED;
-		(void) tcp_output(tp);
-	}
-	return (tcp_close(tp));
-}
-
-/*
- * Close a TCP control block:
- *	discard all space held by the tcp
- *	discard internet protocol block
- *	wake up any sleepers
- */
-struct tcpcb *
-tcp_close(struct tcpcb *tp)
-{
-	register struct tcpiphdr *t;
-	struct socket *so = tp->t_socket;
-	Slirp *slirp = so->slirp;
-	register struct mbuf *m;
-
-	DEBUG_CALL("tcp_close");
-	DEBUG_ARG("tp = %p", tp);
-
-	/* free the reassembly queue, if any */
-	t = tcpfrag_list_first(tp);
-	while (!tcpfrag_list_end(t, tp)) {
-		t = tcpiphdr_next(t);
-		m = tcpiphdr_prev(t)->ti_mbuf;
-		remque(tcpiphdr2qlink(tcpiphdr_prev(t)));
-		m_free(m);
-	}
-	free(tp);
-        so->so_tcpcb = NULL;
-	/* clobber input socket cache if we're closing the cached connection */
-	if (so == slirp->tcp_last_so)
-		slirp->tcp_last_so = &slirp->tcb;
-	so->slirp->cb->unregister_poll_fd(so->s, so->slirp->opaque);
-	closesocket(so->s);
-	sbfree(&so->so_rcv);
-	sbfree(&so->so_snd);
-	sofree(so);
-	return ((struct tcpcb *)0);
-}
-
-/*
- * TCP protocol interface to socket abstraction.
- */
-
-/*
- * User issued close, and wish to trail through shutdown states:
- * if never received SYN, just forget it.  If got a SYN from peer,
- * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
- * If already got a FIN from peer, then almost done; go to LAST_ACK
- * state.  In all other cases, have already sent FIN to peer (e.g.
- * after PRU_SHUTDOWN), and just have to play tedious game waiting
- * for peer to send FIN or not respond to keep-alives, etc.
- * We can let the user exit from the close as soon as the FIN is acked.
- */
-void
-tcp_sockclosed(struct tcpcb *tp)
-{
-
-	DEBUG_CALL("tcp_sockclosed");
-	DEBUG_ARG("tp = %p", tp);
-
-	if (!tp) {
-		return;
-	}
-
-	switch (tp->t_state) {
-
-	case TCPS_CLOSED:
-	case TCPS_LISTEN:
-	case TCPS_SYN_SENT:
-		tp->t_state = TCPS_CLOSED;
-		tp = tcp_close(tp);
-		break;
-
-	case TCPS_SYN_RECEIVED:
-	case TCPS_ESTABLISHED:
-		tp->t_state = TCPS_FIN_WAIT_1;
-		break;
-
-	case TCPS_CLOSE_WAIT:
-		tp->t_state = TCPS_LAST_ACK;
-		break;
-	}
-	tcp_output(tp);
-}
-
-/*
- * Connect to a host on the Internet
- * Called by tcp_input
- * Only do a connect, the tcp fields will be set in tcp_input
- * return 0 if there's a result of the connect,
- * else return -1 means we're still connecting
- * The return value is almost always -1 since the socket is
- * nonblocking.  Connect returns after the SYN is sent, and does
- * not wait for ACK+SYN.
- */
-int tcp_fconnect(struct socket *so, unsigned short af)
-{
-  int ret=0;
-
-  DEBUG_CALL("tcp_fconnect");
-  DEBUG_ARG("so = %p", so);
-
-  ret = so->s = slirp_socket(af, SOCK_STREAM, 0);
-  if (ret >= 0) {
-    int opt, s=so->s;
-    struct sockaddr_storage addr;
-
-    slirp_set_nonblock(s);
-    so->slirp->cb->register_poll_fd(so->s, so->slirp->opaque);
-    slirp_socket_set_fast_reuse(s);
-    opt = 1;
-    setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
-    opt = 1;
-    setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt));
-
-    addr = so->fhost.ss;
-    DEBUG_CALL(" connect()ing");
-    sotranslate_out(so, &addr);
-
-    /* We don't care what port we get */
-    ret = connect(s, (struct sockaddr *)&addr, sockaddr_size(&addr));
-
-    /*
-     * If it's not in progress, it failed, so we just return 0,
-     * without clearing SS_NOFDREF
-     */
-    soisfconnecting(so);
-  }
-
-  return(ret);
-}
-
-/*
- * Accept the socket and connect to the local-host
- *
- * We have a problem. The correct thing to do would be
- * to first connect to the local-host, and only if the
- * connection is accepted, then do an accept() here.
- * But, a) we need to know who's trying to connect
- * to the socket to be able to SYN the local-host, and
- * b) we are already connected to the foreign host by
- * the time it gets to accept(), so... We simply accept
- * here and SYN the local-host.
- */
-void tcp_connect(struct socket *inso)
-{
-    Slirp *slirp = inso->slirp;
-    struct socket *so;
-    struct sockaddr_storage addr;
-    socklen_t addrlen = sizeof(struct sockaddr_storage);
-    struct tcpcb *tp;
-    int s, opt;
-
-    DEBUG_CALL("tcp_connect");
-    DEBUG_ARG("inso = %p", inso);
-
-    /*
-     * If it's an SS_ACCEPTONCE socket, no need to socreate()
-     * another socket, just use the accept() socket.
-     */
-    if (inso->so_state & SS_FACCEPTONCE) {
-        /* FACCEPTONCE already have a tcpcb */
-        so = inso;
-    } else {
-        so = socreate(slirp);
-        if (tcp_attach(so) < 0) {
-            g_free(so); /* NOT sofree */
-            return;
-        }
-        so->lhost = inso->lhost;
-        so->so_ffamily = inso->so_ffamily;
-    }
-
-    tcp_mss(sototcpcb(so), 0);
-
-    s = accept(inso->s, (struct sockaddr *)&addr, &addrlen);
-    if (s < 0) {
-        tcp_close(sototcpcb(so)); /* This will sofree() as well */
-        return;
-    }
-    slirp_set_nonblock(s);
-    so->slirp->cb->register_poll_fd(so->s, so->slirp->opaque);
-    slirp_socket_set_fast_reuse(s);
-    opt = 1;
-    setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(int));
-    slirp_socket_set_nodelay(s);
-
-    so->fhost.ss = addr;
-    sotranslate_accept(so);
-
-    /* Close the accept() socket, set right state */
-    if (inso->so_state & SS_FACCEPTONCE) {
-        /* If we only accept once, close the accept() socket */
-        so->slirp->cb->unregister_poll_fd(so->s, so->slirp->opaque);
-        closesocket(so->s);
-
-        /* Don't select it yet, even though we have an FD */
-        /* if it's not FACCEPTONCE, it's already NOFDREF */
-        so->so_state = SS_NOFDREF;
-    }
-    so->s = s;
-    so->so_state |= SS_INCOMING;
-
-    so->so_iptos = tcp_tos(so);
-    tp = sototcpcb(so);
-
-    tcp_template(tp);
-
-    tp->t_state = TCPS_SYN_SENT;
-    tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
-    tp->iss = slirp->tcp_iss;
-    slirp->tcp_iss += TCP_ISSINCR/2;
-    tcp_sendseqinit(tp);
-    tcp_output(tp);
-}
-
-/*
- * Attach a TCPCB to a socket.
- */
-int
-tcp_attach(struct socket *so)
-{
-	if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
-	   return -1;
-
-	insque(so, &so->slirp->tcb);
-
-	return 0;
-}
-
-/*
- * Set the socket's type of service field
- */
-static const struct tos_t tcptos[] = {
-	  {0, 20, IPTOS_THROUGHPUT, 0},	/* ftp data */
-	  {21, 21, IPTOS_LOWDELAY,  EMU_FTP},	/* ftp control */
-	  {0, 23, IPTOS_LOWDELAY, 0},	/* telnet */
-	  {0, 80, IPTOS_THROUGHPUT, 0},	/* WWW */
-	  {0, 513, IPTOS_LOWDELAY, EMU_RLOGIN|EMU_NOCONNECT},	/* rlogin */
-	  {0, 544, IPTOS_LOWDELAY, EMU_KSH},		/* kshell */
-	  {0, 543, IPTOS_LOWDELAY, 0},	/* klogin */
-	  {0, 6667, IPTOS_THROUGHPUT, EMU_IRC},	/* IRC */
-	  {0, 6668, IPTOS_THROUGHPUT, EMU_IRC},	/* IRC undernet */
-	  {0, 7070, IPTOS_LOWDELAY, EMU_REALAUDIO }, /* RealAudio control */
-	  {0, 113, IPTOS_LOWDELAY, EMU_IDENT }, /* identd protocol */
-	  {0, 0, 0, 0}
-};
-
-static struct emu_t *tcpemu = NULL;
-
-/*
- * Return TOS according to the above table
- */
-uint8_t
-tcp_tos(struct socket *so)
-{
-	int i = 0;
-	struct emu_t *emup;
-
-	while(tcptos[i].tos) {
-		if ((tcptos[i].fport && (ntohs(so->so_fport) == tcptos[i].fport)) ||
-		    (tcptos[i].lport && (ntohs(so->so_lport) == tcptos[i].lport))) {
-			so->so_emu = tcptos[i].emu;
-			return tcptos[i].tos;
-		}
-		i++;
-	}
-
-	/* Nope, lets see if there's a user-added one */
-	for (emup = tcpemu; emup; emup = emup->next) {
-		if ((emup->fport && (ntohs(so->so_fport) == emup->fport)) ||
-		    (emup->lport && (ntohs(so->so_lport) == emup->lport))) {
-			so->so_emu = emup->emu;
-			return emup->tos;
-		}
-	}
-
-	return 0;
-}
-
-/*
- * Emulate programs that try and connect to us
- * This includes ftp (the data connection is
- * initiated by the server) and IRC (DCC CHAT and
- * DCC SEND) for now
- *
- * NOTE: It's possible to crash SLiRP by sending it
- * unstandard strings to emulate... if this is a problem,
- * more checks are needed here
- *
- * XXX Assumes the whole command came in one packet
- *
- * XXX Some ftp clients will have their TOS set to
- * LOWDELAY and so Nagel will kick in.  Because of this,
- * we'll get the first letter, followed by the rest, so
- * we simply scan for ORT instead of PORT...
- * DCC doesn't have this problem because there's other stuff
- * in the packet before the DCC command.
- *
- * Return 1 if the mbuf m is still valid and should be
- * sbappend()ed
- *
- * NOTE: if you return 0 you MUST m_free() the mbuf!
- */
-int
-tcp_emu(struct socket *so, struct mbuf *m)
-{
-	Slirp *slirp = so->slirp;
-	unsigned n1, n2, n3, n4, n5, n6;
-        char buff[257];
-	uint32_t laddr;
-	unsigned lport;
-	char *bptr;
-
-	DEBUG_CALL("tcp_emu");
-	DEBUG_ARG("so = %p", so);
-	DEBUG_ARG("m = %p", m);
-
-	switch(so->so_emu) {
-		int x, i;
-
-        /* TODO: IPv6 */
-	 case EMU_IDENT:
-		/*
-		 * Identification protocol as per rfc-1413
-		 */
-
-		{
-			struct socket *tmpso;
-			struct sockaddr_in addr;
-			socklen_t addrlen = sizeof(struct sockaddr_in);
-			struct sbuf *so_rcv = &so->so_rcv;
-
-			if (m->m_len > so_rcv->sb_datalen
-					- (so_rcv->sb_wptr - so_rcv->sb_data)) {
-			    return 1;
-			}
-
-			memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
-			so_rcv->sb_wptr += m->m_len;
-			so_rcv->sb_rptr += m->m_len;
-			m->m_data[m->m_len] = 0; /* NULL terminate */
-			if (strchr(m->m_data, '\r') || strchr(m->m_data, '\n')) {
-				if (sscanf(so_rcv->sb_data, "%u%*[ ,]%u", &n1, &n2) == 2) {
-					HTONS(n1);
-					HTONS(n2);
-					/* n2 is the one on our host */
-					for (tmpso = slirp->tcb.so_next;
-					     tmpso != &slirp->tcb;
-					     tmpso = tmpso->so_next) {
-						if (tmpso->so_laddr.s_addr == so->so_laddr.s_addr &&
-						    tmpso->so_lport == n2 &&
-						    tmpso->so_faddr.s_addr == so->so_faddr.s_addr &&
-						    tmpso->so_fport == n1) {
-							if (getsockname(tmpso->s,
-								(struct sockaddr *)&addr, &addrlen) == 0)
-							   n2 = addr.sin_port;
-							break;
-						}
-					}
-					NTOHS(n1);
-					NTOHS(n2);
-					so_rcv->sb_cc = snprintf(so_rcv->sb_data,
-								 so_rcv->sb_datalen,
-								 "%d,%d\r\n", n1, n2);
-					so_rcv->sb_rptr = so_rcv->sb_data;
-					so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
-				}
-			}
-			m_free(m);
-			return 0;
-		}
-
-        case EMU_FTP: /* ftp */
-                *(m->m_data+m->m_len) = 0; /* NUL terminate for strstr */
-		if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
-			/*
-			 * Need to emulate the PORT command
-			 */
-			x = sscanf(bptr, "ORT %u,%u,%u,%u,%u,%u\r\n%256[^\177]",
-				   &n1, &n2, &n3, &n4, &n5, &n6, buff);
-			if (x < 6)
-			   return 1;
-
-			laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
-			lport = htons((n5 << 8) | (n6));
-
-			if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
-			                     lport, SS_FACCEPTONCE)) == NULL) {
-			   return 1;
-			}
-			n6 = ntohs(so->so_fport);
-
-			n5 = (n6 >> 8) & 0xff;
-			n6 &= 0xff;
-
-			laddr = ntohl(so->so_faddr.s_addr);
-
-			n1 = ((laddr >> 24) & 0xff);
-			n2 = ((laddr >> 16) & 0xff);
-			n3 = ((laddr >> 8)  & 0xff);
-			n4 =  (laddr & 0xff);
-
-			m->m_len = bptr - m->m_data; /* Adjust length */
-                        m->m_len += snprintf(bptr, m->m_size - m->m_len,
-                                             "ORT %d,%d,%d,%d,%d,%d\r\n%s",
-                                             n1, n2, n3, n4, n5, n6, x==7?buff:"");
-			return 1;
-		} else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
-			/*
-			 * Need to emulate the PASV response
-			 */
-			x = sscanf(bptr, "27 Entering Passive Mode (%u,%u,%u,%u,%u,%u)\r\n%256[^\177]",
-				   &n1, &n2, &n3, &n4, &n5, &n6, buff);
-			if (x < 6)
-			   return 1;
-
-			laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
-			lport = htons((n5 << 8) | (n6));
-
-			if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
-			                     lport, SS_FACCEPTONCE)) == NULL) {
-			   return 1;
-			}
-			n6 = ntohs(so->so_fport);
-
-			n5 = (n6 >> 8) & 0xff;
-			n6 &= 0xff;
-
-			laddr = ntohl(so->so_faddr.s_addr);
-
-			n1 = ((laddr >> 24) & 0xff);
-			n2 = ((laddr >> 16) & 0xff);
-			n3 = ((laddr >> 8)  & 0xff);
-			n4 =  (laddr & 0xff);
-
-			m->m_len = bptr - m->m_data; /* Adjust length */
-			m->m_len += snprintf(bptr, m->m_size - m->m_len,
-                                             "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
-                                             n1, n2, n3, n4, n5, n6, x==7?buff:"");
-
-			return 1;
-		}
-
-		return 1;
-
-	 case EMU_KSH:
-		/*
-		 * The kshell (Kerberos rsh) and shell services both pass
-		 * a local port port number to carry signals to the server
-		 * and stderr to the client.  It is passed at the beginning
-		 * of the connection as a NUL-terminated decimal ASCII string.
-		 */
-		so->so_emu = 0;
-		for (lport = 0, i = 0; i < m->m_len-1; ++i) {
-			if (m->m_data[i] < '0' || m->m_data[i] > '9')
-				return 1;       /* invalid number */
-			lport *= 10;
-			lport += m->m_data[i] - '0';
-		}
-		if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
-		    (so = tcp_listen(slirp, INADDR_ANY, 0, so->so_laddr.s_addr,
-		                     htons(lport), SS_FACCEPTONCE)) != NULL)
-                    m->m_len = snprintf(m->m_data, m->m_size, "%d",
-                                        ntohs(so->so_fport)) + 1;
-		return 1;
-
-	 case EMU_IRC:
-		/*
-		 * Need to emulate DCC CHAT, DCC SEND and DCC MOVE
-		 */
-		*(m->m_data+m->m_len) = 0; /* NULL terminate the string for strstr */
-		if ((bptr = (char *)strstr(m->m_data, "DCC")) == NULL)
-			 return 1;
-
-		/* The %256s is for the broken mIRC */
-		if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) {
-			if ((so = tcp_listen(slirp, INADDR_ANY, 0,
-			                     htonl(laddr), htons(lport),
-			                     SS_FACCEPTONCE)) == NULL) {
-				return 1;
-			}
-			m->m_len = bptr - m->m_data; /* Adjust length */
-                        m->m_len += snprintf(bptr, m->m_size,
-                                             "DCC CHAT chat %lu %u%c\n",
-                                             (unsigned long)ntohl(so->so_faddr.s_addr),
-                                             ntohs(so->so_fport), 1);
-		} else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
-			if ((so = tcp_listen(slirp, INADDR_ANY, 0,
-			                     htonl(laddr), htons(lport),
-			                     SS_FACCEPTONCE)) == NULL) {
-				return 1;
-			}
-			m->m_len = bptr - m->m_data; /* Adjust length */
-                        m->m_len += snprintf(bptr, m->m_size,
-                                             "DCC SEND %s %lu %u %u%c\n", buff,
-                                             (unsigned long)ntohl(so->so_faddr.s_addr),
-                                             ntohs(so->so_fport), n1, 1);
-		} else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
-			if ((so = tcp_listen(slirp, INADDR_ANY, 0,
-			                     htonl(laddr), htons(lport),
-			                     SS_FACCEPTONCE)) == NULL) {
-				return 1;
-			}
-			m->m_len = bptr - m->m_data; /* Adjust length */
-                        m->m_len += snprintf(bptr, m->m_size,
-                                             "DCC MOVE %s %lu %u %u%c\n", buff,
-                                             (unsigned long)ntohl(so->so_faddr.s_addr),
-                                             ntohs(so->so_fport), n1, 1);
-		}
-		return 1;
-
-	 case EMU_REALAUDIO:
-                /*
-		 * RealAudio emulation - JP. We must try to parse the incoming
-		 * data and try to find the two characters that contain the
-		 * port number. Then we redirect an udp port and replace the
-		 * number with the real port we got.
-		 *
-		 * The 1.0 beta versions of the player are not supported
-		 * any more.
-		 *
-		 * A typical packet for player version 1.0 (release version):
-		 *
-		 * 0000:50 4E 41 00 05
-		 * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 ........g.l.c..P
-		 * 0010:4E 43 4C 49 45 4E 54 20 31 30 31 20 41 4C 50 48 NCLIENT 101 ALPH
-		 * 0020:41 6C 00 00 52 00 17 72 61 66 69 6C 65 73 2F 76 Al..R..rafiles/v
-		 * 0030:6F 61 2F 65 6E 67 6C 69 73 68 5F 2E 72 61 79 42 oa/english_.rayB
-		 *
-		 * Now the port number 0x1BD7 is found at offset 0x04 of the
-		 * Now the port number 0x1BD7 is found at offset 0x04 of the
-		 * second packet. This time we received five bytes first and
-		 * then the rest. You never know how many bytes you get.
-		 *
-		 * A typical packet for player version 2.0 (beta):
-		 *
-		 * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA.............
-		 * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .gux.c..Win2.0.0
-		 * 0020:2E 35 6C 00 00 52 00 1C 72 61 66 69 6C 65 73 2F .5l..R..rafiles/
-		 * 0030:77 65 62 73 69 74 65 2F 32 30 72 65 6C 65 61 73 website/20releas
-		 * 0040:65 2E 72 61 79 53 00 00 06 36 42                e.rayS...6B
-		 *
-		 * Port number 0x1BC1 is found at offset 0x0d.
-		 *
-		 * This is just a horrible switch statement. Variable ra tells
-		 * us where we're going.
-		 */
-
-		bptr = m->m_data;
-		while (bptr < m->m_data + m->m_len) {
-			uint16_t p;
-			static int ra = 0;
-			char ra_tbl[4];
-
-			ra_tbl[0] = 0x50;
-			ra_tbl[1] = 0x4e;
-			ra_tbl[2] = 0x41;
-			ra_tbl[3] = 0;
-
-			switch (ra) {
-			 case 0:
-			 case 2:
-			 case 3:
-				if (*bptr++ != ra_tbl[ra]) {
-					ra = 0;
-					continue;
-				}
-				break;
-
-			 case 1:
-				/*
-				 * We may get 0x50 several times, ignore them
-				 */
-				if (*bptr == 0x50) {
-					ra = 1;
-					bptr++;
-					continue;
-				} else if (*bptr++ != ra_tbl[ra]) {
-					ra = 0;
-					continue;
-				}
-				break;
-
-			 case 4:
-				/*
-				 * skip version number
-				 */
-				bptr++;
-				break;
-
-			 case 5:
-				/*
-				 * The difference between versions 1.0 and
-				 * 2.0 is here. For future versions of
-				 * the player this may need to be modified.
-				 */
-				if (*(bptr + 1) == 0x02)
-				   bptr += 8;
-				else
-				   bptr += 4;
-				break;
-
-			 case 6:
-				/* This is the field containing the port
-				 * number that RA-player is listening to.
-				 */
-				lport = (((uint8_t*)bptr)[0] << 8)
-				+ ((uint8_t *)bptr)[1];
-				if (lport < 6970)
-				   lport += 256;   /* don't know why */
-				if (lport < 6970 || lport > 7170)
-				   return 1;       /* failed */
-
-				/* try to get udp port between 6970 - 7170 */
-				for (p = 6970; p < 7071; p++) {
-					if (udp_listen(slirp, INADDR_ANY,
-						       htons(p),
-						       so->so_laddr.s_addr,
-						       htons(lport),
-						       SS_FACCEPTONCE)) {
-						break;
-					}
-				}
-				if (p == 7071)
-				   p = 0;
-				*(uint8_t *)bptr++ = (p >> 8) & 0xff;
-                                *(uint8_t *)bptr = p & 0xff;
-				ra = 0;
-				return 1;   /* port redirected, we're done */
-				break;
-
-			 default:
-				ra = 0;
-			}
-			ra++;
-		}
-		return 1;
-
-	 default:
-		/* Ooops, not emulated, won't call tcp_emu again */
-		so->so_emu = 0;
-		return 1;
-	}
-}
-
-/*
- * Do misc. config of SLiRP while its running.
- * Return 0 if this connections is to be closed, 1 otherwise,
- * return 2 if this is a command-line connection
- */
-int tcp_ctl(struct socket *so)
-{
-    Slirp *slirp = so->slirp;
-    struct sbuf *sb = &so->so_snd;
-    struct gfwd_list *ex_ptr;
-
-    DEBUG_CALL("tcp_ctl");
-    DEBUG_ARG("so = %p", so);
-
-    /* TODO: IPv6 */
-    if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr) {
-        /* Check if it's pty_exec */
-        for (ex_ptr = slirp->guestfwd_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) {
-                if (ex_ptr->write_cb) {
-                    so->s = -1;
-                    so->guestfwd = ex_ptr;
-                    return 1;
-                }
-                DEBUG_MISC(" executing %s", ex_ptr->ex_exec);
-                return fork_exec(so, ex_ptr->ex_exec);
-            }
-        }
-    }
-    sb->sb_cc =
-        snprintf(sb->sb_wptr, sb->sb_datalen - (sb->sb_wptr - sb->sb_data),
-                 "Error: No application configured.\r\n");
-    sb->sb_wptr += sb->sb_cc;
-    return 0;
-}