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slirp/tcp_subr.c 34.9 KB
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/*
 * 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. 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
 *    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.
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 *
 * Please read the file COPYRIGHT for the
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 * terms and conditions of the copyright.
 */

#define WANT_SYS_IOCTL_H
#include <slirp.h>

/* patchable/settable parameters for tcp */
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/* Don't do rfc1323 performance enhancements */
#define TCP_DO_RFC1323 0
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/*
 * Tcp initialization
 */
void
tcp_init()
{
	tcp_iss = 1;		/* wrong */
	tcb.so_next = tcb.so_prev = &tcb;
}

/*
 * 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.
 */
/* struct tcpiphdr * */
void
tcp_template(tp)
	struct tcpcb *tp;
{
	struct socket *so = tp->t_socket;
	register struct tcpiphdr *n = &tp->t_template;

	n->ti_next = n->ti_prev = 0;
	n->ti_x1 = 0;
	n->ti_pr = IPPROTO_TCP;
	n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip));
	n->ti_src = so->so_faddr;
	n->ti_dst = so->so_laddr;
	n->ti_sport = so->so_fport;
	n->ti_dport = so->so_lport;
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	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(tp, ti, m, ack, seq, flags)
	struct tcpcb *tp;
	register struct tcpiphdr *ti;
	register struct mbuf *m;
	tcp_seq ack, seq;
	int flags;
{
	register int tlen;
	int win = 0;

	DEBUG_CALL("tcp_respond");
	DEBUG_ARG("tp = %lx", (long)tp);
	DEBUG_ARG("ti = %lx", (long)ti);
	DEBUG_ARG("m = %lx", (long)m);
	DEBUG_ARG("ack = %u", ack);
	DEBUG_ARG("seq = %u", seq);
	DEBUG_ARG("flags = %x", flags);
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	if (tp)
		win = sbspace(&tp->t_socket->so_rcv);
	if (m == 0) {
		if ((m = m_get()) == NULL)
			return;
#ifdef TCP_COMPAT_42
		tlen = 1;
#else
		tlen = 0;
#endif
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		m->m_data += IF_MAXLINKHDR;
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		*mtod(m, struct tcpiphdr *) = *ti;
		ti = mtod(m, struct tcpiphdr *);
		flags = TH_ACK;
	} else {
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		/*
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		 * ti points into m so the next line is just making
		 * the mbuf point to ti
		 */
		m->m_data = (caddr_t)ti;
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		m->m_len = sizeof (struct tcpiphdr);
		tlen = 0;
#define xchg(a,b,type) { type t; t=a; a=b; b=t; }
		xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, u_int32_t);
		xchg(ti->ti_dport, ti->ti_sport, u_int16_t);
#undef xchg
	}
	ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen));
	tlen += sizeof (struct tcpiphdr);
	m->m_len = tlen;

	ti->ti_next = ti->ti_prev = 0;
	ti->ti_x1 = 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((u_int16_t) (win >> tp->rcv_scale));
	else
		ti->ti_win = htons((u_int16_t)win);
	ti->ti_urp = 0;
	ti->ti_sum = 0;
	ti->ti_sum = cksum(m, tlen);
	((struct ip *)ti)->ip_len = tlen;
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	if(flags & TH_RST)
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	  ((struct ip *)ti)->ip_ttl = MAXTTL;
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	else
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	  ((struct ip *)ti)->ip_ttl = IPDEFTTL;
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	(void) ip_output((struct socket *)0, m);
}

/*
 * Create a new TCP control block, making an
 * empty reassembly queue and hooking it to the argument
 * protocol control block.
 */
struct tcpcb *
tcp_newtcpcb(so)
	struct socket *so;
{
	register struct tcpcb *tp;
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	tp = (struct tcpcb *)malloc(sizeof(*tp));
	if (tp == NULL)
		return ((struct tcpcb *)0);
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	memset((char *) tp, 0, sizeof(struct tcpcb));
	tp->seg_next = tp->seg_prev = (tcpiphdrp_32)tp;
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	tp->t_maxseg = TCP_MSS;
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	tp->t_flags = TCP_DO_RFC1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0;
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	tp->t_socket = so;
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	/*
	 * 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;
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	tp->t_rttvar = TCPTV_SRTTDFLT << 2;
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	tp->t_rttmin = TCPTV_MIN;
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	TCPT_RANGESET(tp->t_rxtcur,
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	    ((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;
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	so->so_tcpcb = tp;

	return (tp);
}

/*
 * Drop a TCP connection, reporting
 * the specified error.  If connection is synchronized,
 * then send a RST to peer.
 */
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struct tcpcb *tcp_drop(struct tcpcb *tp, int err)
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{
/* tcp_drop(tp, errno)
	register struct tcpcb *tp;
	int errno;
{
*/

	DEBUG_CALL("tcp_drop");
	DEBUG_ARG("tp = %lx", (long)tp);
	DEBUG_ARG("errno = %d", errno);
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	if (TCPS_HAVERCVDSYN(tp->t_state)) {
		tp->t_state = TCPS_CLOSED;
		(void) tcp_output(tp);
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		STAT(tcpstat.tcps_drops++);
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	} else
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		STAT(tcpstat.tcps_conndrops++);
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/*	if (errno == ETIMEDOUT && tp->t_softerror)
 *		errno = tp->t_softerror;
 */
/*	so->so_error = errno; */
	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(tp)
	register struct tcpcb *tp;
{
	register struct tcpiphdr *t;
	struct socket *so = tp->t_socket;
	register struct mbuf *m;

	DEBUG_CALL("tcp_close");
	DEBUG_ARG("tp = %lx", (long )tp);
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	/* free the reassembly queue, if any */
	t = (struct tcpiphdr *) tp->seg_next;
	while (t != (struct tcpiphdr *)tp) {
		t = (struct tcpiphdr *)t->ti_next;
		m = (struct mbuf *) REASS_MBUF((struct tcpiphdr *)t->ti_prev);
		remque_32((struct tcpiphdr *) t->ti_prev);
		m_freem(m);
	}
	/* It's static */
/*	if (tp->t_template)
 *		(void) m_free(dtom(tp->t_template));
 */
/*	free(tp, M_PCB);  */
	free(tp);
	so->so_tcpcb = 0;
	soisfdisconnected(so);
	/* clobber input socket cache if we're closing the cached connection */
	if (so == tcp_last_so)
		tcp_last_so = &tcb;
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	closesocket(so->s);
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	sbfree(&so->so_rcv);
	sbfree(&so->so_snd);
	sofree(so);
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	STAT(tcpstat.tcps_closed++);
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	return ((struct tcpcb *)0);
}
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#ifdef notdef
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void
tcp_drain()
{
	/* XXX */
}

/*
 * When a source quench is received, close congestion window
 * to one segment.  We will gradually open it again as we proceed.
 */
void
tcp_quench(i, errno)

	int errno;
{
	struct tcpcb *tp = intotcpcb(inp);

	if (tp)
		tp->snd_cwnd = tp->t_maxseg;
}

#endif /* notdef */

/*
 * 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(tp)
	struct tcpcb *tp;
{

	DEBUG_CALL("tcp_sockclosed");
	DEBUG_ARG("tp = %lx", (long)tp);
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	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;
	}
/*	soisfdisconnecting(tp->t_socket); */
	if (tp && tp->t_state >= TCPS_FIN_WAIT_2)
		soisfdisconnected(tp->t_socket);
	if (tp)
		tcp_output(tp);
}
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/*
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 * 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
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 * nonblocking.  Connect returns after the SYN is sent, and does
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 * not wait for ACK+SYN.
 */
int tcp_fconnect(so)
     struct socket *so;
{
  int ret=0;
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  DEBUG_CALL("tcp_fconnect");
  DEBUG_ARG("so = %lx", (long )so);

  if( (ret=so->s=socket(AF_INET,SOCK_STREAM,0)) >= 0) {
    int opt, s=so->s;
    struct sockaddr_in addr;

    fd_nonblock(s);
    opt = 1;
    setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(opt ));
    opt = 1;
    setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(opt ));
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    addr.sin_family = AF_INET;
    if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) {
      /* It's an alias */
      switch(ntohl(so->so_faddr.s_addr) & 0xff) {
      case CTL_DNS:
	addr.sin_addr = dns_addr;
	break;
      case CTL_ALIAS:
      default:
	addr.sin_addr = loopback_addr;
	break;
      }
    } else
      addr.sin_addr = so->so_faddr;
    addr.sin_port = so->so_fport;
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    DEBUG_MISC((dfd, " connect()ing, addr.sin_port=%d, "
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		"addr.sin_addr.s_addr=%.16s\n",
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		ntohs(addr.sin_port), inet_ntoa(addr.sin_addr)));
    /* We don't care what port we get */
    ret = connect(s,(struct sockaddr *)&addr,sizeof (addr));
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    /*
     * 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
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 *
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 * 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.
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 * But, a) we need to know who's trying to connect
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 * 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.
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 */
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void
tcp_connect(inso)
	struct socket *inso;
{
	struct socket *so;
	struct sockaddr_in addr;
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	socklen_t addrlen = sizeof(struct sockaddr_in);
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	struct tcpcb *tp;
	int s, opt;

	DEBUG_CALL("tcp_connect");
	DEBUG_ARG("inso = %lx", (long)inso);
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	/*
	 * 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 {
		if ((so = socreate()) == NULL) {
			/* If it failed, get rid of the pending connection */
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			closesocket(accept(inso->s,(struct sockaddr *)&addr,&addrlen));
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			return;
		}
		if (tcp_attach(so) < 0) {
			free(so); /* NOT sofree */
			return;
		}
		so->so_laddr = inso->so_laddr;
		so->so_lport = inso->so_lport;
	}
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	(void) tcp_mss(sototcpcb(so), 0);

	if ((s = accept(inso->s,(struct sockaddr *)&addr,&addrlen)) < 0) {
		tcp_close(sototcpcb(so)); /* This will sofree() as well */
		return;
	}
	fd_nonblock(s);
	opt = 1;
	setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
	opt = 1;
	setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
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	opt = 1;
	setsockopt(s,IPPROTO_TCP,TCP_NODELAY,(char *)&opt,sizeof(int));
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	so->so_fport = addr.sin_port;
	so->so_faddr = addr.sin_addr;
	/* Translate connections from localhost to the real hostname */
	if (so->so_faddr.s_addr == 0 || so->so_faddr.s_addr == loopback_addr.s_addr)
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	   so->so_faddr = alias_addr;
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	/* Close the accept() socket, set right state */
	if (inso->so_state & SS_FACCEPTONCE) {
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		closesocket(so->s); /* If we only accept once, close the accept() socket */
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		so->so_state = SS_NOFDREF; /* Don't select it yet, even though we have an FD */
					   /* if it's not FACCEPTONCE, it's already NOFDREF */
	}
	so->s = s;
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	so->so_iptos = tcp_tos(so);
	tp = sototcpcb(so);

	tcp_template(tp);
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	/* Compute window scaling to request.  */
/*	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
 *		(TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
 *		tp->request_r_scale++;
 */

/*	soisconnecting(so); */ /* NOFDREF used instead */
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	STAT(tcpstat.tcps_connattempt++);
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	tp->t_state = TCPS_SYN_SENT;
	tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
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	tp->iss = tcp_iss;
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	tcp_iss += TCP_ISSINCR/2;
	tcp_sendseqinit(tp);
	tcp_output(tp);
}

/*
 * Attach a TCPCB to a socket.
 */
int
tcp_attach(so)
	struct socket *so;
{
	if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
	   return -1;
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	insque(so, &tcb);

	return 0;
}

/*
 * Set the socket's type of service field
 */
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static const struct tos_t tcptos[] = {
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	  {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, 514, IPTOS_LOWDELAY, EMU_RSH|EMU_NOCONNECT},	/* shell */
	  {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}
};
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#ifdef CONFIG_QEMU
static
#endif
struct emu_t *tcpemu = 0;
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/*
 * Return TOS according to the above table
 */
u_int8_t
tcp_tos(so)
	struct socket *so;
{
	int i = 0;
	struct emu_t *emup;
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578
579
580
581
582
583
584
	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++;
	}
585
586
587
588
589
590
591
592
593
	/* 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;
		}
	}
594
595
596
597
	return 0;
}
598
#if 0
599
int do_echo = -1;
600
#endif
601
602
603
604
605
606

/*
 * 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
607
 *
608
609
610
611
612
 * 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
613
 *
614
615
616
617
618
619
 * 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.
620
621
 *
 * Return 1 if the mbuf m is still valid and should be
622
 * sbappend()ed
623
 *
624
625
626
627
628
629
630
631
 * NOTE: if you return 0 you MUST m_free() the mbuf!
 */
int
tcp_emu(so, m)
	struct socket *so;
	struct mbuf *m;
{
	u_int n1, n2, n3, n4, n5, n6;
632
        char buff[257];
633
634
635
	u_int32_t laddr;
	u_int lport;
	char *bptr;
636
637
638
639
	DEBUG_CALL("tcp_emu");
	DEBUG_ARG("so = %lx", (long)so);
	DEBUG_ARG("m = %lx", (long)m);
640
641
642
	switch(so->so_emu) {
		int x, i;
643
644
645
646
647
	 case EMU_IDENT:
		/*
		 * Identification protocol as per rfc-1413
		 */
648
649
650
651
		{
			struct socket *tmpso;
			struct sockaddr_in addr;
652
			socklen_t addrlen = sizeof(struct sockaddr_in);
653
			struct sbuf *so_rcv = &so->so_rcv;
654
655
656
657
658
659
			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')) {
660
				if (sscanf(so_rcv->sb_data, "%u%*[ ,]%u", &n1, &n2) == 2) {
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
					HTONS(n1);
					HTONS(n2);
					/* n2 is the one on our host */
					for (tmpso = tcb.so_next; tmpso != &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 = ntohs(addr.sin_port);
							break;
						}
					}
				}
676
677
678
                                so_rcv->sb_cc = snprintf(so_rcv->sb_data,
                                                         so_rcv->sb_datalen,
                                                         "%d,%d\r\n", n1, n2);
679
680
681
682
683
684
				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;
		}
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
#if 0
	 case EMU_RLOGIN:
		/*
		 * Rlogin emulation
		 * First we accumulate all the initial option negotiation,
		 * then fork_exec() rlogin according to the  options
		 */
		{
			int i, i2, n;
			char *ptr;
			char args[100];
			char term[100];
			struct sbuf *so_snd = &so->so_snd;
			struct sbuf *so_rcv = &so->so_rcv;
700
701
702
703
704
705
706
707
708
709
710
			/* First check if they have a priveladged port, or too much data has arrived */
			if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
			    (m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
				memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
				so_snd->sb_wptr += 18;
				so_snd->sb_cc += 18;
				tcp_sockclosed(sototcpcb(so));
				m_free(m);
				return 0;
			}
711
712
713
714
715
716
			/* Append the current data */
			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_free(m);
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
			/*
			 * Check if we have all the initial options,
			 * and build argument list to rlogin while we're here
			 */
			n = 0;
			ptr = so_rcv->sb_data;
			args[0] = 0;
			term[0] = 0;
			while (ptr < so_rcv->sb_wptr) {
				if (*ptr++ == 0) {
					n++;
					if (n == 2) {
						sprintf(args, "rlogin -l %s %s",
							ptr, inet_ntoa(so->so_faddr));
					} else if (n == 3) {
						i2 = so_rcv->sb_wptr - ptr;
						for (i = 0; i < i2; i++) {
							if (ptr[i] == '/') {
								ptr[i] = 0;
#ifdef HAVE_SETENV
								sprintf(term, "%s", ptr);
#else
								sprintf(term, "TERM=%s", ptr);
#endif
								ptr[i] = '/';
								break;
							}
						}
					}
				}
			}
749
750
751
			if (n != 4)
			   return 0;
752
753
754
755
756
757
758
759
760
761
			/* We have it, set our term variable and fork_exec() */
#ifdef HAVE_SETENV
			setenv("TERM", term, 1);
#else
			putenv(term);
#endif
			fork_exec(so, args, 2);
			term[0] = 0;
			so->so_emu = 0;
762
763
764
765
766
			/* And finally, send the client a 0 character */
			so_snd->sb_wptr[0] = 0;
			so_snd->sb_wptr++;
			so_snd->sb_cc++;
767
768
769
			return 0;
		}
770
771
772
773
774
775
776
777
778
779
780
781
782
783
	 case EMU_RSH:
		/*
		 * rsh emulation
		 * First we accumulate all the initial option negotiation,
		 * then rsh_exec() rsh according to the  options
		 */
		{
			int  n;
			char *ptr;
			char *user;
			char *args;
			struct sbuf *so_snd = &so->so_snd;
			struct sbuf *so_rcv = &so->so_rcv;
784
785
786
787
788
789
790
791
792
793
794
			/* First check if they have a priveladged port, or too much data has arrived */
			if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
			    (m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
				memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
				so_snd->sb_wptr += 18;
				so_snd->sb_cc += 18;
				tcp_sockclosed(sototcpcb(so));
				m_free(m);
				return 0;
			}
795
796
797
798
799
800
			/* Append the current data */
			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_free(m);
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
			/*
			 * Check if we have all the initial options,
			 * and build argument list to rlogin while we're here
			 */
			n = 0;
			ptr = so_rcv->sb_data;
			user="";
			args="";
			if (so->extra==NULL) {
				struct socket *ns;
				struct tcpcb* tp;
				int port=atoi(ptr);
				if (port <= 0) return 0;
                if (port > 1023 || port < 512) {
                  memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
                  so_snd->sb_wptr += 18;
                  so_snd->sb_cc += 18;
                  tcp_sockclosed(sototcpcb(so));
                  return 0;
                }
				if ((ns=socreate()) == NULL)
                  return 0;
				if (tcp_attach(ns)<0) {
                  free(ns);
                  return 0;
				}

				ns->so_laddr=so->so_laddr;
				ns->so_lport=htons(port);

				(void) tcp_mss(sototcpcb(ns), 0);

				ns->so_faddr=so->so_faddr;
				ns->so_fport=htons(IPPORT_RESERVED-1); /* Use a fake port. */
837
				if (ns->so_faddr.s_addr == 0 ||
838
					ns->so_faddr.s_addr == loopback_addr.s_addr)
839
                  ns->so_faddr = alias_addr;
840
841
842

				ns->so_iptos = tcp_tos(ns);
				tp = sototcpcb(ns);
843
844
				tcp_template(tp);
845
846
847
848
849
850
851
852
853
				/* Compute window scaling to request.  */
				/*	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
				 *		(TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
				 *		tp->request_r_scale++;
				 */

                /*soisfconnecting(ns);*/
854
				STAT(tcpstat.tcps_connattempt++);
855
856
857
				tp->t_state = TCPS_SYN_SENT;
				tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
858
				tp->iss = tcp_iss;
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
				tcp_iss += TCP_ISSINCR/2;
				tcp_sendseqinit(tp);
				tcp_output(tp);
				so->extra=ns;
			}
			while (ptr < so_rcv->sb_wptr) {
              if (*ptr++ == 0) {
                n++;
                if (n == 2) {
                  user=ptr;
                } else if (n == 3) {
                  args=ptr;
                }
              }
			}
874
875
876
			if (n != 4)
              return 0;
877
878
879
880
			rsh_exec(so,so->extra, user, inet_ntoa(so->so_faddr), args);
			so->so_emu = 0;
			so->extra=NULL;
881
882
883
884
885
			/* And finally, send the client a 0 character */
			so_snd->sb_wptr[0] = 0;
			so_snd->sb_wptr++;
			so_snd->sb_cc++;
886
887
888
889
890
891
892
893
894
			return 0;
		}

	 case EMU_CTL:
		{
			int num;
			struct sbuf *so_snd = &so->so_snd;
			struct sbuf *so_rcv = &so->so_rcv;
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
			/*
			 * If there is binary data here, we save it in so->so_m
			 */
			if (!so->so_m) {
			  int rxlen;
			  char *rxdata;
			  rxdata=mtod(m, char *);
			  for (rxlen=m->m_len; rxlen; rxlen--) {
			    if (*rxdata++ & 0x80) {
			      so->so_m = m;
			      return 0;
			    }
			  }
			} /* if(so->so_m==NULL) */
910
911
912
913
914
			/*
			 * Append the line
			 */
			sbappendsb(so_rcv, m);
915
916
917
918
			/* To avoid going over the edge of the buffer, we reset it */
			if (so_snd->sb_cc == 0)
			   so_snd->sb_wptr = so_snd->sb_rptr = so_snd->sb_data;
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
			/*
			 * A bit of a hack:
			 * If the first packet we get here is 1 byte long, then it
			 * was done in telnet character mode, therefore we must echo
			 * the characters as they come.  Otherwise, we echo nothing,
			 * because in linemode, the line is already echoed
			 * XXX two or more control connections won't work
			 */
			if (do_echo == -1) {
				if (m->m_len == 1) do_echo = 1;
				else do_echo = 0;
			}
			if (do_echo) {
			  sbappendsb(so_snd, m);
			  m_free(m);
			  tcp_output(sototcpcb(so)); /* XXX */
			} else
			  m_free(m);
938
939
940
941
942
943
			num = 0;
			while (num < so->so_rcv.sb_cc) {
				if (*(so->so_rcv.sb_rptr + num) == '\n' ||
				    *(so->so_rcv.sb_rptr + num) == '\r') {
					int n;
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
					*(so_rcv->sb_rptr + num) = 0;
					if (ctl_password && !ctl_password_ok) {
						/* Need a password */
						if (sscanf(so_rcv->sb_rptr, "pass %256s", buff) == 1) {
							if (strcmp(buff, ctl_password) == 0) {
								ctl_password_ok = 1;
								n = sprintf(so_snd->sb_wptr,
									    "Password OK.\r\n");
								goto do_prompt;
							}
						}
						n = sprintf(so_snd->sb_wptr,
					 "Error: Password required, log on with \"pass PASSWORD\"\r\n");
						goto do_prompt;
					}
					cfg_quitting = 0;
					n = do_config(so_rcv->sb_rptr, so, PRN_SPRINTF);
					if (!cfg_quitting) {
						/* Register the printed data */
do_prompt:
						so_snd->sb_cc += n;
						so_snd->sb_wptr += n;
						/* Add prompt */
						n = sprintf(so_snd->sb_wptr, "Slirp> ");
						so_snd->sb_cc += n;
						so_snd->sb_wptr += n;
					}
					/* Drop so_rcv data */
					so_rcv->sb_cc = 0;
					so_rcv->sb_wptr = so_rcv->sb_rptr = so_rcv->sb_data;
					tcp_output(sototcpcb(so)); /* Send the reply */
				}
				num++;
			}
			return 0;
		}
981
#endif
982
983
984
985
986
        case EMU_FTP: /* ftp */
		*(m->m_data+m->m_len) = 0; /* NULL terminate for strstr */
		if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
			/*
			 * Need to emulate the PORT command
987
			 */
988
			x = sscanf(bptr, "ORT %u,%u,%u,%u,%u,%u\r\n%256[^\177]",
989
990
991
				   &n1, &n2, &n3, &n4, &n5, &n6, buff);
			if (x < 6)
			   return 1;
992
993
994
			laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
			lport = htons((n5 << 8) | (n6));
995
996
997
			if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL)
			   return 1;
998
999
			n6 = ntohs(so->so_fport);
1000
1001
1002
			n5 = (n6 >> 8) & 0xff;
			n6 &= 0xff;
1003
1004
			laddr = ntohl(so->so_faddr.s_addr);
1005
1006
1007
1008
1009
			n1 = ((laddr >> 24) & 0xff);
			n2 = ((laddr >> 16) & 0xff);
			n3 = ((laddr >> 8)  & 0xff);
			n4 =  (laddr & 0xff);
1010
1011
			m->m_len = bptr - m->m_data; /* Adjust length */
1012
1013
1014
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
                                             "ORT %d,%d,%d,%d,%d,%d\r\n%s",
                                             n1, n2, n3, n4, n5, n6, x==7?buff:"");
1015
1016
1017
1018
1019
			return 1;
		} else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
			/*
			 * Need to emulate the PASV response
			 */
1020
			x = sscanf(bptr, "27 Entering Passive Mode (%u,%u,%u,%u,%u,%u)\r\n%256[^\177]",
1021
1022
1023
				   &n1, &n2, &n3, &n4, &n5, &n6, buff);
			if (x < 6)
			   return 1;
1024
1025
1026
			laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
			lport = htons((n5 << 8) | (n6));
1027
1028
1029
			if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL)
			   return 1;
1030
1031
			n6 = ntohs(so->so_fport);
1032
1033
1034
			n5 = (n6 >> 8) & 0xff;
			n6 &= 0xff;
1035
1036
			laddr = ntohl(so->so_faddr.s_addr);
1037
1038
1039
1040
1041
			n1 = ((laddr >> 24) & 0xff);
			n2 = ((laddr >> 16) & 0xff);
			n3 = ((laddr >> 8)  & 0xff);
			n4 =  (laddr & 0xff);
1042
1043
			m->m_len = bptr - m->m_data; /* Adjust length */
1044
1045
1046
			m->m_len += snprintf(bptr, m->m_hdr.mh_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:"");
1047
1048
1049
			return 1;
		}
1050
1051
		return 1;
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
	 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 = solisten(0, so->so_laddr.s_addr, htons(lport), SS_FACCEPTONCE)) != NULL)
1069
1070
                    m->m_len = snprintf(m->m_data, m->m_hdr.mh_size, "%d",
                                        ntohs(so->so_fport)) + 1;
1071
		return 1;
1072
1073
1074
1075
1076
1077
1078
1079
	 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;
1080
1081
1082
1083
1084
		/* The %256s is for the broken mIRC */
		if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) {
			if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
				return 1;
1085
1086
			m->m_len = bptr - m->m_data; /* Adjust length */
1087
1088
1089
1090
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
                                             "DCC CHAT chat %lu %u%c\n",
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
                                             ntohs(so->so_fport), 1);
1091
1092
1093
		} else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
			if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
				return 1;
1094
1095
			m->m_len = bptr - m->m_data; /* Adjust length */
1096
1097
1098
1099
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
                                             "DCC SEND %s %lu %u %u%c\n", buff,
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
                                             ntohs(so->so_fport), n1, 1);
1100
1101
1102
		} else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
			if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
				return 1;
1103
1104
			m->m_len = bptr - m->m_data; /* Adjust length */
1105
1106
1107
1108
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
                                             "DCC MOVE %s %lu %u %u%c\n", buff,
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
                                             ntohs(so->so_fport), n1, 1);
1109
1110
1111
1112
		}
		return 1;

	 case EMU_REALAUDIO:
1113
                /*
1114
1115
1116
1117
1118
1119
1120
		 * 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.
1121
		 *
1122
		 * A typical packet for player version 1.0 (release version):
1123
		 *
1124
		 * 0000:50 4E 41 00 05
1125
1126
1127
1128
		 * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 .....ร—..gรฆlรœc..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
1129
		 *
1130
1131
1132
1133
1134
1135
		 * 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):
1136
		 *
1137
1138
1139
1140
1141
		 * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA...........ร.
		 * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .guxรตc..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
1142
		 *
1143
		 * Port number 0x1BC1 is found at offset 0x0d.
1144
		 *
1145
1146
1147
		 * This is just a horrible switch statement. Variable ra tells
		 * us where we're going.
		 */
1148
1149
1150
1151
1152
		bptr = m->m_data;
		while (bptr < m->m_data + m->m_len) {
			u_short p;
			static int ra = 0;
1153
			char ra_tbl[4];
1154
1155
1156
1157
1158
			ra_tbl[0] = 0x50;
			ra_tbl[1] = 0x4e;
			ra_tbl[2] = 0x41;
			ra_tbl[3] = 0;
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
			switch (ra) {
			 case 0:
			 case 2:
			 case 3:
				if (*bptr++ != ra_tbl[ra]) {
					ra = 0;
					continue;
				}
				break;
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
			 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;
1183
1184
1185
			 case 4:
				/*
1186
1187
1188
1189
				 * skip version number
				 */
				bptr++;
				break;
1190
1191
			 case 5:
1192
1193
1194
1195
1196
1197
1198
1199
1200
				/*
				 * 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;
1201
1202
				break;
1203
1204
1205
1206
			 case 6:
				/* This is the field containing the port
				 * number that RA-player is listening to.
				 */
1207
				lport = (((u_char*)bptr)[0] << 8)
1208
				+ ((u_char *)bptr)[1];
1209
				if (lport < 6970)
1210
1211
1212
				   lport += 256;   /* don't know why */
				if (lport < 6970 || lport > 7170)
				   return 1;       /* failed */
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
				/* try to get udp port between 6970 - 7170 */
				for (p = 6970; p < 7071; p++) {
					if (udp_listen( htons(p),
						       so->so_laddr.s_addr,
						       htons(lport),
						       SS_FACCEPTONCE)) {
						break;
					}
				}
				if (p == 7071)
				   p = 0;
				*(u_char *)bptr++ = (p >> 8) & 0xff;
				*(u_char *)bptr++ = p & 0xff;
1227
				ra = 0;
1228
				return 1;   /* port redirected, we're done */
1229
1230
				break;
1231
			 default:
1232
				ra = 0;
1233
1234
1235
			}
			ra++;
		}
1236
1237
		return 1;
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
	 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(so)
	struct socket *so;
{
	struct sbuf *sb = &so->so_snd;
	int command;
 	struct ex_list *ex_ptr;
	int do_pty;
bellard authored
1258
        //	struct socket *tmpso;
1259
1260
1261
	DEBUG_CALL("tcp_ctl");
	DEBUG_ARG("so = %lx", (long )so);
1262
1263
#if 0
1264
1265
1266
1267
1268
1269
1270
1271
	/*
	 * Check if they're authorised
	 */
	if (ctl_addr.s_addr && (ctl_addr.s_addr == -1 || (so->so_laddr.s_addr != ctl_addr.s_addr))) {
		sb->sb_cc = sprintf(sb->sb_wptr,"Error: Permission denied.\r\n");
		sb->sb_wptr += sb->sb_cc;
		return 0;
	}
1272
#endif
1273
	command = (ntohl(so->so_faddr.s_addr) & 0xff);
1274
1275
1276
	switch(command) {
	default: /* Check for exec's */
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
		/*
		 * Check if it's pty_exec
		 */
		for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
			if (ex_ptr->ex_fport == so->so_fport &&
			    command == ex_ptr->ex_addr) {
				do_pty = ex_ptr->ex_pty;
				goto do_exec;
			}
		}
1288
1289
1290
1291
1292
		/*
		 * Nothing bound..
		 */
		/* tcp_fconnect(so); */
1293
1294
1295
		/* FALLTHROUGH */
	case CTL_ALIAS:
1296
1297
          sb->sb_cc = snprintf(sb->sb_wptr, sb->sb_datalen - (sb->sb_wptr - sb->sb_data),
                               "Error: No application configured.\r\n");
1298
1299
1300
1301
1302
1303
	  sb->sb_wptr += sb->sb_cc;
	  return(0);

	do_exec:
		DEBUG_MISC((dfd, " executing %s \n",ex_ptr->ex_exec));
		return(fork_exec(so, ex_ptr->ex_exec, do_pty));
1304
1305
#if 0
1306
1307
	case CTL_CMD:
	   for (tmpso = tcb.so_next; tmpso != &tcb; tmpso = tmpso->so_next) {
1308
1309
	     if (tmpso->so_emu == EMU_CTL &&
		 !(tmpso->so_tcpcb?
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
		   (tmpso->so_tcpcb->t_state & (TCPS_TIME_WAIT|TCPS_LAST_ACK))
		   :0)) {
	       /* Ooops, control connection already active */
	       sb->sb_cc = sprintf(sb->sb_wptr,"Sorry, already connected.\r\n");
	       sb->sb_wptr += sb->sb_cc;
	       return 0;
	     }
	   }
	   so->so_emu = EMU_CTL;
	   ctl_password_ok = 0;
	   sb->sb_cc = sprintf(sb->sb_wptr, "Slirp command-line ready (type \"help\" for help).\r\nSlirp> ");
	   sb->sb_wptr += sb->sb_cc;
	   do_echo=-1;
	   return(2);
#endif
1325
	}
1326
}