| /* | 
 |  * 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. | 
 |  * | 
 |  * Please read the file COPYRIGHT for the | 
 |  * terms and conditions of the copyright. | 
 |  */ | 
 |  | 
 | #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; | 
 | 	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; | 
 |  | 
 | 	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) | 
 | { | 
 | 	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); | 
 |  | 
 | 	if (tp) | 
 | 		win = sbspace(&tp->t_socket->so_rcv); | 
 |         if (m == NULL) { | 
 | 		if ((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 *); | 
 | 		flags = TH_ACK; | 
 | 	} else { | 
 | 		/* | 
 | 		 * ti points into m so the next line is just making | 
 | 		 * the mbuf point to ti | 
 | 		 */ | 
 | 		m->m_data = (caddr_t)ti; | 
 |  | 
 | 		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, uint32_t); | 
 | 		xchg(ti->ti_dport, ti->ti_sport, uint16_t); | 
 | #undef xchg | 
 | 	} | 
 | 	ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen)); | 
 | 	tlen += sizeof (struct tcpiphdr); | 
 | 	m->m_len = tlen; | 
 |  | 
 |         ti->ti_mbuf = NULL; | 
 | 	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((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 ip *)ti)->ip_len = tlen; | 
 |  | 
 | 	if(flags & TH_RST) | 
 | 	  ((struct ip *)ti)->ip_ttl = MAXTTL; | 
 | 	else | 
 | 	  ((struct ip *)ti)->ip_ttl = IPDEFTTL; | 
 |  | 
 | 	(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(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 = TCP_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 = %lx", (long)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 = %lx", (long )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; | 
 | 	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 = %lx", (long)tp); | 
 |  | 
 | 	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; | 
 | 	} | 
 | 	if (tp) | 
 | 		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) | 
 | { | 
 |   Slirp *slirp = so->slirp; | 
 |   int ret=0; | 
 |  | 
 |   DEBUG_CALL("tcp_fconnect"); | 
 |   DEBUG_ARG("so = %lx", (long )so); | 
 |  | 
 |   if( (ret = so->s = qemu_socket(AF_INET,SOCK_STREAM,0)) >= 0) { | 
 |     int opt, s=so->s; | 
 |     struct sockaddr_in addr; | 
 |  | 
 |     socket_set_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 )); | 
 |  | 
 |     addr.sin_family = AF_INET; | 
 |     if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) == | 
 |         slirp->vnetwork_addr.s_addr) { | 
 |       /* It's an alias */ | 
 |       if (so->so_faddr.s_addr == slirp->vnameserver_addr.s_addr) { | 
 | 	if (get_dns_addr(&addr.sin_addr) < 0) | 
 | 	  addr.sin_addr = loopback_addr; | 
 |       } else { | 
 | 	addr.sin_addr = loopback_addr; | 
 |       } | 
 |     } else | 
 |       addr.sin_addr = so->so_faddr; | 
 |     addr.sin_port = so->so_fport; | 
 |  | 
 |     DEBUG_MISC((dfd, " connect()ing, addr.sin_port=%d, " | 
 | 		"addr.sin_addr.s_addr=%.16s\n", | 
 | 		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)); | 
 |  | 
 |     /* | 
 |      * 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_in addr; | 
 | 	socklen_t addrlen = sizeof(struct sockaddr_in); | 
 | 	struct tcpcb *tp; | 
 | 	int s, opt; | 
 |  | 
 | 	DEBUG_CALL("tcp_connect"); | 
 | 	DEBUG_ARG("inso = %lx", (long)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 { | 
 | 		if ((so = socreate(slirp)) == NULL) { | 
 | 			/* If it failed, get rid of the pending connection */ | 
 | 			closesocket(accept(inso->s,(struct sockaddr *)&addr,&addrlen)); | 
 | 			return; | 
 | 		} | 
 | 		if (tcp_attach(so) < 0) { | 
 | 			free(so); /* NOT sofree */ | 
 | 			return; | 
 | 		} | 
 | 		so->so_laddr = inso->so_laddr; | 
 | 		so->so_lport = inso->so_lport; | 
 | 	} | 
 |  | 
 | 	(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; | 
 | 	} | 
 | 	socket_set_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)); | 
 | 	opt = 1; | 
 | 	setsockopt(s,IPPROTO_TCP,TCP_NODELAY,(char *)&opt,sizeof(int)); | 
 |  | 
 | 	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) | 
 | 	   so->so_faddr = slirp->vhost_addr; | 
 |  | 
 | 	/* Close the accept() socket, set right state */ | 
 | 	if (inso->so_state & SS_FACCEPTONCE) { | 
 | 		closesocket(so->s); /* If we only accept once, close the accept() socket */ | 
 | 		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; | 
 | 	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, 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} | 
 | }; | 
 |  | 
 | 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; | 
 | 	u_int n1, n2, n3, n4, n5, n6; | 
 |         char buff[257]; | 
 | 	uint32_t laddr; | 
 | 	u_int lport; | 
 | 	char *bptr; | 
 |  | 
 | 	DEBUG_CALL("tcp_emu"); | 
 | 	DEBUG_ARG("so = %lx", (long)so); | 
 | 	DEBUG_ARG("m = %lx", (long)m); | 
 |  | 
 | 	switch(so->so_emu) { | 
 | 		int x, i; | 
 |  | 
 | 	 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; | 
 |  | 
 | 			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 = ntohs(addr.sin_port); | 
 | 							break; | 
 | 						} | 
 | 					} | 
 | 				} | 
 |                                 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_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:""); | 
 | 			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_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:""); | 
 |  | 
 | 			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_hdr.mh_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_hdr.mh_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_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); | 
 | 		} 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_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); | 
 | 		} | 
 | 		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) { | 
 | 			u_short 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 = (((u_char*)bptr)[0] << 8) | 
 | 				+ ((u_char *)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; | 
 | 				*(u_char *)bptr++ = (p >> 8) & 0xff; | 
 |                                 *(u_char *)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 ex_list *ex_ptr; | 
 |     int do_pty; | 
 |  | 
 |     DEBUG_CALL("tcp_ctl"); | 
 |     DEBUG_ARG("so = %lx", (long )so); | 
 |  | 
 |     if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr) { | 
 |         /* Check if it's pty_exec */ | 
 |         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) { | 
 |                 if (ex_ptr->ex_pty == 3) { | 
 |                     so->s = -1; | 
 |                     so->extra = (void *)ex_ptr->ex_exec; | 
 |                     return 1; | 
 |                 } | 
 |                 do_pty = ex_ptr->ex_pty; | 
 |                 DEBUG_MISC((dfd, " executing %s\n", ex_ptr->ex_exec)); | 
 |                 return fork_exec(so, ex_ptr->ex_exec, do_pty); | 
 |             } | 
 |         } | 
 |     } | 
 |     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; | 
 | } |