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1 /*
2  * Copyright (c) 1982, 1986, 1988, 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)tcp_subr.c	8.1 (Berkeley) 6/10/93
30  * tcp_subr.c,v 1.5 1994/10/08 22:39:58 phk Exp
31  */
32 
33 /*
34  * Changes and additions relating to SLiRP
35  * Copyright (c) 1995 Danny Gasparovski.
36  *
37  * Please read the file COPYRIGHT for the
38  * terms and conditions of the copyright.
39  */
40 
41 #include <slirp.h>
42 
43 /* patchable/settable parameters for tcp */
44 /* Don't do rfc1323 performance enhancements */
45 #define TCP_DO_RFC1323 0
46 
47 /*
48  * Tcp initialization
49  */
50 void
tcp_init(void)51 tcp_init(void)
52 {
53 	tcp_iss = 1;		/* wrong */
54 	tcb.so_next = tcb.so_prev = &tcb;
55 }
56 
57 /*
58  * Create template to be used to send tcp packets on a connection.
59  * Call after host entry created, fills
60  * in a skeletal tcp/ip header, minimizing the amount of work
61  * necessary when the connection is used.
62  */
63 /* struct tcpiphdr * */
64 void
tcp_template(struct tcpcb * tp)65 tcp_template(struct tcpcb *tp)
66 {
67 	struct socket *so = tp->t_socket;
68 	register struct tcpiphdr *n = &tp->t_template;
69 
70 	n->ti_mbuf = NULL;
71 	n->ti_x1 = 0;
72 	n->ti_pr = IPPROTO_TCP;
73 	n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip));
74 	n->ti_src = so->so_faddr;
75 	n->ti_dst = so->so_laddr;
76 	n->ti_sport = so->so_fport;
77 	n->ti_dport = so->so_lport;
78 
79 	n->ti_seq = 0;
80 	n->ti_ack = 0;
81 	n->ti_x2 = 0;
82 	n->ti_off = 5;
83 	n->ti_flags = 0;
84 	n->ti_win = 0;
85 	n->ti_sum = 0;
86 	n->ti_urp = 0;
87 }
88 
89 /*
90  * Send a single message to the TCP at address specified by
91  * the given TCP/IP header.  If m == 0, then we make a copy
92  * of the tcpiphdr at ti and send directly to the addressed host.
93  * This is used to force keep alive messages out using the TCP
94  * template for a connection tp->t_template.  If flags are given
95  * then we send a message back to the TCP which originated the
96  * segment ti, and discard the mbuf containing it and any other
97  * attached mbufs.
98  *
99  * In any case the ack and sequence number of the transmitted
100  * segment are as specified by the parameters.
101  */
102 void
tcp_respond(struct tcpcb * tp,struct tcpiphdr * ti,struct mbuf * m,tcp_seq ack,tcp_seq seq,int flags)103 tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
104             tcp_seq ack, tcp_seq seq, int flags)
105 {
106 	register int tlen;
107 	int win = 0;
108 
109 	DEBUG_CALL("tcp_respond");
110 	DEBUG_ARG("tp = %lx", (long)tp);
111 	DEBUG_ARG("ti = %lx", (long)ti);
112 	DEBUG_ARG("m = %lx", (long)m);
113 	DEBUG_ARG("ack = %u", ack);
114 	DEBUG_ARG("seq = %u", seq);
115 	DEBUG_ARG("flags = %x", flags);
116 
117 	if (tp)
118 		win = sbspace(&tp->t_socket->so_rcv);
119         if (m == NULL) {
120 		if ((m = m_get()) == NULL)
121 			return;
122 #ifdef TCP_COMPAT_42
123 		tlen = 1;
124 #else
125 		tlen = 0;
126 #endif
127 		m->m_data += IF_MAXLINKHDR;
128 		*mtod(m, struct tcpiphdr *) = *ti;
129 		ti = mtod(m, struct tcpiphdr *);
130 		flags = TH_ACK;
131 	} else {
132 		/*
133 		 * ti points into m so the next line is just making
134 		 * the mbuf point to ti
135 		 */
136 		m->m_data = (caddr_t)ti;
137 
138 		m->m_len = sizeof (struct tcpiphdr);
139 		tlen = 0;
140 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
141 		xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, u_int32_t);
142 		xchg(ti->ti_dport, ti->ti_sport, u_int16_t);
143 #undef xchg
144 	}
145 	ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen));
146 	tlen += sizeof (struct tcpiphdr);
147 	m->m_len = tlen;
148 
149         ti->ti_mbuf = NULL;
150 	ti->ti_x1 = 0;
151 	ti->ti_seq = htonl(seq);
152 	ti->ti_ack = htonl(ack);
153 	ti->ti_x2 = 0;
154 	ti->ti_off = sizeof (struct tcphdr) >> 2;
155 	ti->ti_flags = flags;
156 	if (tp)
157 		ti->ti_win = htons((u_int16_t) (win >> tp->rcv_scale));
158 	else
159 		ti->ti_win = htons((u_int16_t)win);
160 	ti->ti_urp = 0;
161 	ti->ti_sum = 0;
162 	ti->ti_sum = cksum(m, tlen);
163 	((struct ip *)ti)->ip_len = tlen;
164 
165 	if(flags & TH_RST)
166 	  ((struct ip *)ti)->ip_ttl = MAXTTL;
167 	else
168 	  ((struct ip *)ti)->ip_ttl = IPDEFTTL;
169 
170 	(void) ip_output((struct socket *)0, m);
171 }
172 
173 /*
174  * Create a new TCP control block, making an
175  * empty reassembly queue and hooking it to the argument
176  * protocol control block.
177  */
178 struct tcpcb *
tcp_newtcpcb(struct socket * so)179 tcp_newtcpcb(struct socket *so)
180 {
181 	register struct tcpcb *tp;
182 
183 	tp = (struct tcpcb *)malloc(sizeof(*tp));
184 	if (tp == NULL)
185 		return ((struct tcpcb *)0);
186 
187 	memset((char *) tp, 0, sizeof(struct tcpcb));
188 	tp->seg_next = tp->seg_prev = (struct tcpiphdr*)tp;
189 	tp->t_maxseg = TCP_MSS;
190 
191 	tp->t_flags = TCP_DO_RFC1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0;
192 	tp->t_socket = so;
193 
194 	/*
195 	 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
196 	 * rtt estimate.  Set rttvar so that srtt + 2 * rttvar gives
197 	 * reasonable initial retransmit time.
198 	 */
199 	tp->t_srtt = TCPTV_SRTTBASE;
200 	tp->t_rttvar = TCPTV_SRTTDFLT << 2;
201 	tp->t_rttmin = TCPTV_MIN;
202 
203 	TCPT_RANGESET(tp->t_rxtcur,
204 	    ((TCPTV_SRTTBASE >> 2) + (TCPTV_SRTTDFLT << 2)) >> 1,
205 	    TCPTV_MIN, TCPTV_REXMTMAX);
206 
207 	tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
208 	tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
209 	tp->t_state = TCPS_CLOSED;
210 
211 	so->so_tcpcb = tp;
212 
213 	return (tp);
214 }
215 
216 /*
217  * Drop a TCP connection, reporting
218  * the specified error.  If connection is synchronized,
219  * then send a RST to peer.
220  */
tcp_drop(struct tcpcb * tp,int err)221 struct tcpcb *tcp_drop(struct tcpcb *tp, int err)
222 {
223 /* tcp_drop(tp, errno)
224 	register struct tcpcb *tp;
225 	int errno;
226 {
227 */
228 
229 	DEBUG_CALL("tcp_drop");
230 	DEBUG_ARG("tp = %lx", (long)tp);
231 	DEBUG_ARG("errno = %d", errno);
232 
233 	if (TCPS_HAVERCVDSYN(tp->t_state)) {
234 		tp->t_state = TCPS_CLOSED;
235 		(void) tcp_output(tp);
236 		STAT(tcpstat.tcps_drops++);
237 	} else
238 		STAT(tcpstat.tcps_conndrops++);
239 /*	if (errno == ETIMEDOUT && tp->t_softerror)
240  *		errno = tp->t_softerror;
241  */
242 /*	so->so_error = errno; */
243 	return (tcp_close(tp));
244 }
245 
246 /*
247  * Close a TCP control block:
248  *	discard all space held by the tcp
249  *	discard internet protocol block
250  *	wake up any sleepers
251  */
252 struct tcpcb *
tcp_close(struct tcpcb * tp)253 tcp_close(struct tcpcb *tp)
254 {
255 	register struct tcpiphdr *t;
256 	struct socket *so = tp->t_socket;
257 	register struct mbuf *m;
258 
259 	DEBUG_CALL("tcp_close");
260 	DEBUG_ARG("tp = %lx", (long )tp);
261 
262 	/* free the reassembly queue, if any */
263 	t = tcpfrag_list_first(tp);
264 	while (!tcpfrag_list_end(t, tp)) {
265 		t = tcpiphdr_next(t);
266 		m = tcpiphdr_prev(t)->ti_mbuf;
267 		remque(tcpiphdr2qlink(tcpiphdr_prev(t)));
268 		m_freem(m);
269 	}
270 	/* It's static */
271 /*	if (tp->t_template)
272  *		(void) m_free(dtom(tp->t_template));
273  */
274 /*	free(tp, M_PCB);  */
275 	free(tp);
276         so->so_tcpcb = NULL;
277 	soisfdisconnected(so);
278 	/* clobber input socket cache if we're closing the cached connection */
279 	if (so == tcp_last_so)
280 		tcp_last_so = &tcb;
281 	closesocket(so->s);
282 	sbfree(&so->so_rcv);
283 	sbfree(&so->so_snd);
284 	sofree(so);
285 	STAT(tcpstat.tcps_closed++);
286 	return ((struct tcpcb *)0);
287 }
288 
289 #ifdef notdef
290 void
tcp_drain()291 tcp_drain()
292 {
293 	/* XXX */
294 }
295 
296 /*
297  * When a source quench is received, close congestion window
298  * to one segment.  We will gradually open it again as we proceed.
299  */
300 void
tcp_quench(i,errno)301 tcp_quench(i, errno)
302 
303 	int errno;
304 {
305 	struct tcpcb *tp = intotcpcb(inp);
306 
307 	if (tp)
308 		tp->snd_cwnd = tp->t_maxseg;
309 }
310 
311 #endif /* notdef */
312 
313 /*
314  * TCP protocol interface to socket abstraction.
315  */
316 
317 /*
318  * User issued close, and wish to trail through shutdown states:
319  * if never received SYN, just forget it.  If got a SYN from peer,
320  * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
321  * If already got a FIN from peer, then almost done; go to LAST_ACK
322  * state.  In all other cases, have already sent FIN to peer (e.g.
323  * after PRU_SHUTDOWN), and just have to play tedious game waiting
324  * for peer to send FIN or not respond to keep-alives, etc.
325  * We can let the user exit from the close as soon as the FIN is acked.
326  */
327 void
tcp_sockclosed(struct tcpcb * tp)328 tcp_sockclosed(struct tcpcb *tp)
329 {
330 
331 	DEBUG_CALL("tcp_sockclosed");
332 	DEBUG_ARG("tp = %lx", (long)tp);
333 
334 	switch (tp->t_state) {
335 
336 	case TCPS_CLOSED:
337 	case TCPS_LISTEN:
338 	case TCPS_SYN_SENT:
339 		tp->t_state = TCPS_CLOSED;
340 		tp = tcp_close(tp);
341 		break;
342 
343 	case TCPS_SYN_RECEIVED:
344 	case TCPS_ESTABLISHED:
345 		tp->t_state = TCPS_FIN_WAIT_1;
346 		break;
347 
348 	case TCPS_CLOSE_WAIT:
349 		tp->t_state = TCPS_LAST_ACK;
350 		break;
351 	}
352 /*	soisfdisconnecting(tp->t_socket); */
353 	if (tp && tp->t_state >= TCPS_FIN_WAIT_2)
354 		soisfdisconnected(tp->t_socket);
355 	if (tp)
356 		tcp_output(tp);
357 }
358 
359 /*
360  * Connect to a host on the Internet
361  * Called by tcp_input
362  * Only do a connect, the tcp fields will be set in tcp_input
363  * return 0 if there's a result of the connect,
364  * else return -1 means we're still connecting
365  * The return value is almost always -1 since the socket is
366  * nonblocking.  Connect returns after the SYN is sent, and does
367  * not wait for ACK+SYN.
368  */
tcp_fconnect(struct socket * so)369 int tcp_fconnect(struct socket *so)
370 {
371   int ret=0;
372 
373   DEBUG_CALL("tcp_fconnect");
374   DEBUG_ARG("so = %lx", (long )so);
375 
376   if( (ret=so->s=socket(AF_INET,SOCK_STREAM,0)) >= 0) {
377     int opt, s=so->s;
378     struct sockaddr_in addr;
379 
380     fd_nonblock(s);
381     opt = 1;
382     setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(opt ));
383     opt = 1;
384     setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(opt ));
385 
386     addr.sin_family = AF_INET;
387     if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) {
388       /* It's an alias */
389       switch(ntohl(so->so_faddr.s_addr) & 0xff) {
390       case CTL_DNS:
391 	addr.sin_addr = dns_addr;
392 	break;
393       case CTL_ALIAS:
394       default:
395 	addr.sin_addr = loopback_addr;
396 	break;
397       }
398     } else
399       addr.sin_addr = so->so_faddr;
400     addr.sin_port = so->so_fport;
401 
402     DEBUG_MISC((dfd, " connect()ing, addr.sin_port=%d, "
403 		"addr.sin_addr.s_addr=%.16s\n",
404 		ntohs(addr.sin_port), inet_ntoa(addr.sin_addr)));
405     /* We don't care what port we get */
406     ret = connect(s,(struct sockaddr *)&addr,sizeof (addr));
407 
408     /*
409      * If it's not in progress, it failed, so we just return 0,
410      * without clearing SS_NOFDREF
411      */
412     soisfconnecting(so);
413   }
414 
415   return(ret);
416 }
417 
418 /*
419  * Accept the socket and connect to the local-host
420  *
421  * We have a problem. The correct thing to do would be
422  * to first connect to the local-host, and only if the
423  * connection is accepted, then do an accept() here.
424  * But, a) we need to know who's trying to connect
425  * to the socket to be able to SYN the local-host, and
426  * b) we are already connected to the foreign host by
427  * the time it gets to accept(), so... We simply accept
428  * here and SYN the local-host.
429  */
430 void
tcp_connect(struct socket * inso)431 tcp_connect(struct socket *inso)
432 {
433 	struct socket *so;
434 	struct sockaddr_in addr;
435 	socklen_t addrlen = sizeof(struct sockaddr_in);
436 	struct tcpcb *tp;
437 	int s, opt;
438 
439 	DEBUG_CALL("tcp_connect");
440 	DEBUG_ARG("inso = %lx", (long)inso);
441 
442 	/*
443 	 * If it's an SS_ACCEPTONCE socket, no need to socreate()
444 	 * another socket, just use the accept() socket.
445 	 */
446 	if (inso->so_state & SS_FACCEPTONCE) {
447 		/* FACCEPTONCE already have a tcpcb */
448 		so = inso;
449 	} else {
450 		if ((so = socreate()) == NULL) {
451 			/* If it failed, get rid of the pending connection */
452 			closesocket(accept(inso->s,(struct sockaddr *)&addr,&addrlen));
453 			return;
454 		}
455 		if (tcp_attach(so) < 0) {
456 			free(so); /* NOT sofree */
457 			return;
458 		}
459 		so->so_laddr = inso->so_laddr;
460 		so->so_lport = inso->so_lport;
461 	}
462 
463 	(void) tcp_mss(sototcpcb(so), 0);
464 
465 	if ((s = accept(inso->s,(struct sockaddr *)&addr,&addrlen)) < 0) {
466 		tcp_close(sototcpcb(so)); /* This will sofree() as well */
467 		return;
468 	}
469 	fd_nonblock(s);
470 	opt = 1;
471 	setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
472 	opt = 1;
473 	setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
474 	opt = 1;
475 	setsockopt(s,IPPROTO_TCP,TCP_NODELAY,(char *)&opt,sizeof(int));
476 
477 	so->so_fport = addr.sin_port;
478 	so->so_faddr = addr.sin_addr;
479 	/* Translate connections from localhost to the real hostname */
480 	if (so->so_faddr.s_addr == 0 || so->so_faddr.s_addr == loopback_addr.s_addr)
481 	   so->so_faddr = alias_addr;
482 
483 	/* Close the accept() socket, set right state */
484 	if (inso->so_state & SS_FACCEPTONCE) {
485 		closesocket(so->s); /* If we only accept once, close the accept() socket */
486 		so->so_state = SS_NOFDREF; /* Don't select it yet, even though we have an FD */
487 					   /* if it's not FACCEPTONCE, it's already NOFDREF */
488 	}
489 	so->s = s;
490 
491 	so->so_iptos = tcp_tos(so);
492 	tp = sototcpcb(so);
493 
494 	tcp_template(tp);
495 
496 	/* Compute window scaling to request.  */
497 /*	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
498  *		(TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
499  *		tp->request_r_scale++;
500  */
501 
502 /*	soisconnecting(so); */ /* NOFDREF used instead */
503 	STAT(tcpstat.tcps_connattempt++);
504 
505 	tp->t_state = TCPS_SYN_SENT;
506 	tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
507 	tp->iss = tcp_iss;
508 	tcp_iss += TCP_ISSINCR/2;
509 	tcp_sendseqinit(tp);
510 	tcp_output(tp);
511 }
512 
513 /*
514  * Attach a TCPCB to a socket.
515  */
516 int
tcp_attach(struct socket * so)517 tcp_attach(struct socket *so)
518 {
519 	if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
520 	   return -1;
521 
522 	insque(so, &tcb);
523 
524 	return 0;
525 }
526 
527 /*
528  * Set the socket's type of service field
529  */
530 static const struct tos_t tcptos[] = {
531 	  {0, 20, IPTOS_THROUGHPUT, 0},	/* ftp data */
532 	  {21, 21, IPTOS_LOWDELAY,  EMU_FTP},	/* ftp control */
533 	  {0, 23, IPTOS_LOWDELAY, 0},	/* telnet */
534 	  {0, 80, IPTOS_THROUGHPUT, 0},	/* WWW */
535 	  {0, 513, IPTOS_LOWDELAY, EMU_RLOGIN|EMU_NOCONNECT},	/* rlogin */
536 	  {0, 514, IPTOS_LOWDELAY, EMU_RSH|EMU_NOCONNECT},	/* shell */
537 	  {0, 544, IPTOS_LOWDELAY, EMU_KSH},		/* kshell */
538 	  {0, 543, IPTOS_LOWDELAY, 0},	/* klogin */
539 	  {0, 6667, IPTOS_THROUGHPUT, EMU_IRC},	/* IRC */
540 	  {0, 6668, IPTOS_THROUGHPUT, EMU_IRC},	/* IRC undernet */
541 	  {0, 7070, IPTOS_LOWDELAY, EMU_REALAUDIO }, /* RealAudio control */
542 	  {0, 113, IPTOS_LOWDELAY, EMU_IDENT }, /* identd protocol */
543 	  {0, 0, 0, 0}
544 };
545 
546 #ifdef CONFIG_QEMU
547 static
548 #endif
549 struct emu_t *tcpemu = NULL;
550 
551 /*
552  * Return TOS according to the above table
553  */
554 u_int8_t
tcp_tos(struct socket * so)555 tcp_tos(struct socket *so)
556 {
557 	int i = 0;
558 	struct emu_t *emup;
559 
560 	while(tcptos[i].tos) {
561 		if ((tcptos[i].fport && (ntohs(so->so_fport) == tcptos[i].fport)) ||
562 		    (tcptos[i].lport && (ntohs(so->so_lport) == tcptos[i].lport))) {
563 			so->so_emu = tcptos[i].emu;
564 			return tcptos[i].tos;
565 		}
566 		i++;
567 	}
568 
569 	/* Nope, lets see if there's a user-added one */
570 	for (emup = tcpemu; emup; emup = emup->next) {
571 		if ((emup->fport && (ntohs(so->so_fport) == emup->fport)) ||
572 		    (emup->lport && (ntohs(so->so_lport) == emup->lport))) {
573 			so->so_emu = emup->emu;
574 			return emup->tos;
575 		}
576 	}
577 
578 	return 0;
579 }
580 
581 #if 0
582 int do_echo = -1;
583 #endif
584 
585 /*
586  * Emulate programs that try and connect to us
587  * This includes ftp (the data connection is
588  * initiated by the server) and IRC (DCC CHAT and
589  * DCC SEND) for now
590  *
591  * NOTE: It's possible to crash SLiRP by sending it
592  * unstandard strings to emulate... if this is a problem,
593  * more checks are needed here
594  *
595  * XXX Assumes the whole command came in one packet
596  *
597  * XXX Some ftp clients will have their TOS set to
598  * LOWDELAY and so Nagel will kick in.  Because of this,
599  * we'll get the first letter, followed by the rest, so
600  * we simply scan for ORT instead of PORT...
601  * DCC doesn't have this problem because there's other stuff
602  * in the packet before the DCC command.
603  *
604  * Return 1 if the mbuf m is still valid and should be
605  * sbappend()ed
606  *
607  * NOTE: if you return 0 you MUST m_free() the mbuf!
608  */
609 int
tcp_emu(struct socket * so,struct mbuf * m)610 tcp_emu(struct socket *so, struct mbuf *m)
611 {
612 	u_int n1, n2, n3, n4, n5, n6;
613         char buff[257];
614 	u_int32_t laddr;
615 	u_int lport;
616 	char *bptr;
617 
618 	DEBUG_CALL("tcp_emu");
619 	DEBUG_ARG("so = %lx", (long)so);
620 	DEBUG_ARG("m = %lx", (long)m);
621 
622 	switch(so->so_emu) {
623 		int x, i;
624 
625 	 case EMU_IDENT:
626 		/*
627 		 * Identification protocol as per rfc-1413
628 		 */
629 
630 		{
631 			struct socket *tmpso;
632 			struct sockaddr_in addr;
633 			socklen_t addrlen = sizeof(struct sockaddr_in);
634 			struct sbuf *so_rcv = &so->so_rcv;
635 
636 			memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
637 			so_rcv->sb_wptr += m->m_len;
638 			so_rcv->sb_rptr += m->m_len;
639 			m->m_data[m->m_len] = 0; /* NULL terminate */
640 			if (strchr(m->m_data, '\r') || strchr(m->m_data, '\n')) {
641 				if (sscanf(so_rcv->sb_data, "%u%*[ ,]%u", &n1, &n2) == 2) {
642 					HTONS(n1);
643 					HTONS(n2);
644 					/* n2 is the one on our host */
645 					for (tmpso = tcb.so_next; tmpso != &tcb; tmpso = tmpso->so_next) {
646 						if (tmpso->so_laddr.s_addr == so->so_laddr.s_addr &&
647 						    tmpso->so_lport == n2 &&
648 						    tmpso->so_faddr.s_addr == so->so_faddr.s_addr &&
649 						    tmpso->so_fport == n1) {
650 							if (getsockname(tmpso->s,
651 								(struct sockaddr *)&addr, &addrlen) == 0)
652 							   n2 = ntohs(addr.sin_port);
653 							break;
654 						}
655 					}
656 				}
657                                 so_rcv->sb_cc = snprintf(so_rcv->sb_data,
658                                                          so_rcv->sb_datalen,
659                                                          "%d,%d\r\n", n1, n2);
660 				so_rcv->sb_rptr = so_rcv->sb_data;
661 				so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
662 			}
663 			m_free(m);
664 			return 0;
665 		}
666 
667 #if 0
668 	 case EMU_RLOGIN:
669 		/*
670 		 * Rlogin emulation
671 		 * First we accumulate all the initial option negotiation,
672 		 * then fork_exec() rlogin according to the  options
673 		 */
674 		{
675 			int i, i2, n;
676 			char *ptr;
677 			char args[100];
678 			char term[100];
679 			struct sbuf *so_snd = &so->so_snd;
680 			struct sbuf *so_rcv = &so->so_rcv;
681 
682 			/* First check if they have a priveladged port, or too much data has arrived */
683 			if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
684 			    (m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
685 				memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
686 				so_snd->sb_wptr += 18;
687 				so_snd->sb_cc += 18;
688 				tcp_sockclosed(sototcpcb(so));
689 				m_free(m);
690 				return 0;
691 			}
692 
693 			/* Append the current data */
694 			memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
695 			so_rcv->sb_wptr += m->m_len;
696 			so_rcv->sb_rptr += m->m_len;
697 			m_free(m);
698 
699 			/*
700 			 * Check if we have all the initial options,
701 			 * and build argument list to rlogin while we're here
702 			 */
703 			n = 0;
704 			ptr = so_rcv->sb_data;
705 			args[0] = 0;
706 			term[0] = 0;
707 			while (ptr < so_rcv->sb_wptr) {
708 				if (*ptr++ == 0) {
709 					n++;
710 					if (n == 2) {
711 						sprintf(args, "rlogin -l %s %s",
712 							ptr, inet_ntoa(so->so_faddr));
713 					} else if (n == 3) {
714 						i2 = so_rcv->sb_wptr - ptr;
715 						for (i = 0; i < i2; i++) {
716 							if (ptr[i] == '/') {
717 								ptr[i] = 0;
718 #ifdef HAVE_SETENV
719 								sprintf(term, "%s", ptr);
720 #else
721 								sprintf(term, "TERM=%s", ptr);
722 #endif
723 								ptr[i] = '/';
724 								break;
725 							}
726 						}
727 					}
728 				}
729 			}
730 
731 			if (n != 4)
732 			   return 0;
733 
734 			/* We have it, set our term variable and fork_exec() */
735 #ifdef HAVE_SETENV
736 			setenv("TERM", term, 1);
737 #else
738 			putenv(term);
739 #endif
740 			fork_exec(so, args, 2);
741 			term[0] = 0;
742 			so->so_emu = 0;
743 
744 			/* And finally, send the client a 0 character */
745 			so_snd->sb_wptr[0] = 0;
746 			so_snd->sb_wptr++;
747 			so_snd->sb_cc++;
748 
749 			return 0;
750 		}
751 
752 	 case EMU_RSH:
753 		/*
754 		 * rsh emulation
755 		 * First we accumulate all the initial option negotiation,
756 		 * then rsh_exec() rsh according to the  options
757 		 */
758 		{
759 			int  n;
760 			char *ptr;
761 			char *user;
762 			char *args;
763 			struct sbuf *so_snd = &so->so_snd;
764 			struct sbuf *so_rcv = &so->so_rcv;
765 
766 			/* First check if they have a priveladged port, or too much data has arrived */
767 			if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
768 			    (m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
769 				memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
770 				so_snd->sb_wptr += 18;
771 				so_snd->sb_cc += 18;
772 				tcp_sockclosed(sototcpcb(so));
773 				m_free(m);
774 				return 0;
775 			}
776 
777 			/* Append the current data */
778 			memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
779 			so_rcv->sb_wptr += m->m_len;
780 			so_rcv->sb_rptr += m->m_len;
781 			m_free(m);
782 
783 			/*
784 			 * Check if we have all the initial options,
785 			 * and build argument list to rlogin while we're here
786 			 */
787 			n = 0;
788 			ptr = so_rcv->sb_data;
789 			user="";
790 			args="";
791 			if (so->extra==NULL) {
792 				struct socket *ns;
793 				struct tcpcb* tp;
794 				int port=atoi(ptr);
795 				if (port <= 0) return 0;
796                 if (port > 1023 || port < 512) {
797                   memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
798                   so_snd->sb_wptr += 18;
799                   so_snd->sb_cc += 18;
800                   tcp_sockclosed(sototcpcb(so));
801                   return 0;
802                 }
803 				if ((ns=socreate()) == NULL)
804                   return 0;
805 				if (tcp_attach(ns)<0) {
806                   free(ns);
807                   return 0;
808 				}
809 
810 				ns->so_laddr=so->so_laddr;
811 				ns->so_lport=htons(port);
812 
813 				(void) tcp_mss(sototcpcb(ns), 0);
814 
815 				ns->so_faddr=so->so_faddr;
816 				ns->so_fport=htons(IPPORT_RESERVED-1); /* Use a fake port. */
817 
818 				if (ns->so_faddr.s_addr == 0 ||
819 					ns->so_faddr.s_addr == loopback_addr.s_addr)
820                   ns->so_faddr = alias_addr;
821 
822 				ns->so_iptos = tcp_tos(ns);
823 				tp = sototcpcb(ns);
824 
825 				tcp_template(tp);
826 
827 				/* Compute window scaling to request.  */
828 				/*	while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
829 				 *		(TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
830 				 *		tp->request_r_scale++;
831 				 */
832 
833                 /*soisfconnecting(ns);*/
834 
835 				STAT(tcpstat.tcps_connattempt++);
836 
837 				tp->t_state = TCPS_SYN_SENT;
838 				tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
839 				tp->iss = tcp_iss;
840 				tcp_iss += TCP_ISSINCR/2;
841 				tcp_sendseqinit(tp);
842 				tcp_output(tp);
843 				so->extra=ns;
844 			}
845 			while (ptr < so_rcv->sb_wptr) {
846               if (*ptr++ == 0) {
847                 n++;
848                 if (n == 2) {
849                   user=ptr;
850                 } else if (n == 3) {
851                   args=ptr;
852                 }
853               }
854 			}
855 
856 			if (n != 4)
857               return 0;
858 
859 			rsh_exec(so,so->extra, user, inet_ntoa(so->so_faddr), args);
860 			so->so_emu = 0;
861 			so->extra=NULL;
862 
863 			/* And finally, send the client a 0 character */
864 			so_snd->sb_wptr[0] = 0;
865 			so_snd->sb_wptr++;
866 			so_snd->sb_cc++;
867 
868 			return 0;
869 		}
870 
871 	 case EMU_CTL:
872 		{
873 			int num;
874 			struct sbuf *so_snd = &so->so_snd;
875 			struct sbuf *so_rcv = &so->so_rcv;
876 
877 			/*
878 			 * If there is binary data here, we save it in so->so_m
879 			 */
880 			if (!so->so_m) {
881 			  int rxlen;
882 			  char *rxdata;
883 			  rxdata=mtod(m, char *);
884 			  for (rxlen=m->m_len; rxlen; rxlen--) {
885 			    if (*rxdata++ & 0x80) {
886 			      so->so_m = m;
887 			      return 0;
888 			    }
889 			  }
890 			} /* if(so->so_m==NULL) */
891 
892 			/*
893 			 * Append the line
894 			 */
895 			sbappendsb(so_rcv, m);
896 
897 			/* To avoid going over the edge of the buffer, we reset it */
898 			if (so_snd->sb_cc == 0)
899 			   so_snd->sb_wptr = so_snd->sb_rptr = so_snd->sb_data;
900 
901 			/*
902 			 * A bit of a hack:
903 			 * If the first packet we get here is 1 byte long, then it
904 			 * was done in telnet character mode, therefore we must echo
905 			 * the characters as they come.  Otherwise, we echo nothing,
906 			 * because in linemode, the line is already echoed
907 			 * XXX two or more control connections won't work
908 			 */
909 			if (do_echo == -1) {
910 				if (m->m_len == 1) do_echo = 1;
911 				else do_echo = 0;
912 			}
913 			if (do_echo) {
914 			  sbappendsb(so_snd, m);
915 			  m_free(m);
916 			  tcp_output(sototcpcb(so)); /* XXX */
917 			} else
918 			  m_free(m);
919 
920 			num = 0;
921 			while (num < so->so_rcv.sb_cc) {
922 				if (*(so->so_rcv.sb_rptr + num) == '\n' ||
923 				    *(so->so_rcv.sb_rptr + num) == '\r') {
924 					int n;
925 
926 					*(so_rcv->sb_rptr + num) = 0;
927 					if (ctl_password && !ctl_password_ok) {
928 						/* Need a password */
929 						if (sscanf(so_rcv->sb_rptr, "pass %256s", buff) == 1) {
930 							if (strcmp(buff, ctl_password) == 0) {
931 								ctl_password_ok = 1;
932 								n = sprintf(so_snd->sb_wptr,
933 									    "Password OK.\r\n");
934 								goto do_prompt;
935 							}
936 						}
937 						n = sprintf(so_snd->sb_wptr,
938 					 "Error: Password required, log on with \"pass PASSWORD\"\r\n");
939 						goto do_prompt;
940 					}
941 					cfg_quitting = 0;
942 					n = do_config(so_rcv->sb_rptr, so, PRN_SPRINTF);
943 					if (!cfg_quitting) {
944 						/* Register the printed data */
945 do_prompt:
946 						so_snd->sb_cc += n;
947 						so_snd->sb_wptr += n;
948 						/* Add prompt */
949 						n = sprintf(so_snd->sb_wptr, "Slirp> ");
950 						so_snd->sb_cc += n;
951 						so_snd->sb_wptr += n;
952 					}
953 					/* Drop so_rcv data */
954 					so_rcv->sb_cc = 0;
955 					so_rcv->sb_wptr = so_rcv->sb_rptr = so_rcv->sb_data;
956 					tcp_output(sototcpcb(so)); /* Send the reply */
957 				}
958 				num++;
959 			}
960 			return 0;
961 		}
962 #endif
963         case EMU_FTP: /* ftp */
964                 *(m->m_data+m->m_len) = 0; /* NUL terminate for strstr */
965 		if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
966 			/*
967 			 * Need to emulate the PORT command
968 			 */
969 			x = sscanf(bptr, "ORT %u,%u,%u,%u,%u,%u\r\n%256[^\177]",
970 				   &n1, &n2, &n3, &n4, &n5, &n6, buff);
971 			if (x < 6)
972 			   return 1;
973 
974 			laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
975 			lport = htons((n5 << 8) | (n6));
976 
977 			if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL)
978 			   return 1;
979 
980 			n6 = ntohs(so->so_fport);
981 
982 			n5 = (n6 >> 8) & 0xff;
983 			n6 &= 0xff;
984 
985 			laddr = ntohl(so->so_faddr.s_addr);
986 
987 			n1 = ((laddr >> 24) & 0xff);
988 			n2 = ((laddr >> 16) & 0xff);
989 			n3 = ((laddr >> 8)  & 0xff);
990 			n4 =  (laddr & 0xff);
991 
992 			m->m_len = bptr - m->m_data; /* Adjust length */
993                         m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
994                                              "ORT %d,%d,%d,%d,%d,%d\r\n%s",
995                                              n1, n2, n3, n4, n5, n6, x==7?buff:"");
996 			return 1;
997 		} else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
998 			/*
999 			 * Need to emulate the PASV response
1000 			 */
1001 			x = sscanf(bptr, "27 Entering Passive Mode (%u,%u,%u,%u,%u,%u)\r\n%256[^\177]",
1002 				   &n1, &n2, &n3, &n4, &n5, &n6, buff);
1003 			if (x < 6)
1004 			   return 1;
1005 
1006 			laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
1007 			lport = htons((n5 << 8) | (n6));
1008 
1009 			if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL)
1010 			   return 1;
1011 
1012 			n6 = ntohs(so->so_fport);
1013 
1014 			n5 = (n6 >> 8) & 0xff;
1015 			n6 &= 0xff;
1016 
1017 			laddr = ntohl(so->so_faddr.s_addr);
1018 
1019 			n1 = ((laddr >> 24) & 0xff);
1020 			n2 = ((laddr >> 16) & 0xff);
1021 			n3 = ((laddr >> 8)  & 0xff);
1022 			n4 =  (laddr & 0xff);
1023 
1024 			m->m_len = bptr - m->m_data; /* Adjust length */
1025 			m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
1026                                              "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
1027                                              n1, n2, n3, n4, n5, n6, x==7?buff:"");
1028 
1029 			return 1;
1030 		}
1031 
1032 		return 1;
1033 
1034 	 case EMU_KSH:
1035 		/*
1036 		 * The kshell (Kerberos rsh) and shell services both pass
1037 		 * a local port port number to carry signals to the server
1038 		 * and stderr to the client.  It is passed at the beginning
1039 		 * of the connection as a NUL-terminated decimal ASCII string.
1040 		 */
1041 		so->so_emu = 0;
1042 		for (lport = 0, i = 0; i < m->m_len-1; ++i) {
1043 			if (m->m_data[i] < '0' || m->m_data[i] > '9')
1044 				return 1;       /* invalid number */
1045 			lport *= 10;
1046 			lport += m->m_data[i] - '0';
1047 		}
1048 		if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
1049 		    (so = solisten(0, so->so_laddr.s_addr, htons(lport), SS_FACCEPTONCE)) != NULL)
1050                     m->m_len = snprintf(m->m_data, m->m_hdr.mh_size, "%d",
1051                                         ntohs(so->so_fport)) + 1;
1052 		return 1;
1053 
1054 	 case EMU_IRC:
1055 		/*
1056 		 * Need to emulate DCC CHAT, DCC SEND and DCC MOVE
1057 		 */
1058 		*(m->m_data+m->m_len) = 0; /* NULL terminate the string for strstr */
1059 		if ((bptr = (char *)strstr(m->m_data, "DCC")) == NULL)
1060 			 return 1;
1061 
1062 		/* The %256s is for the broken mIRC */
1063 		if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) {
1064 			if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1065 				return 1;
1066 
1067 			m->m_len = bptr - m->m_data; /* Adjust length */
1068                         m->m_len += snprintf(bptr, m->m_hdr.mh_size,
1069                                              "DCC CHAT chat %lu %u%c\n",
1070                                              (unsigned long)ntohl(so->so_faddr.s_addr),
1071                                              ntohs(so->so_fport), 1);
1072 		} else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
1073 			if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1074 				return 1;
1075 
1076 			m->m_len = bptr - m->m_data; /* Adjust length */
1077                         m->m_len += snprintf(bptr, m->m_hdr.mh_size,
1078                                              "DCC SEND %s %lu %u %u%c\n", buff,
1079                                              (unsigned long)ntohl(so->so_faddr.s_addr),
1080                                              ntohs(so->so_fport), n1, 1);
1081 		} else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
1082 			if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1083 				return 1;
1084 
1085 			m->m_len = bptr - m->m_data; /* Adjust length */
1086                         m->m_len += snprintf(bptr, m->m_hdr.mh_size,
1087                                              "DCC MOVE %s %lu %u %u%c\n", buff,
1088                                              (unsigned long)ntohl(so->so_faddr.s_addr),
1089                                              ntohs(so->so_fport), n1, 1);
1090 		}
1091 		return 1;
1092 
1093 	 case EMU_REALAUDIO:
1094                 /*
1095 		 * RealAudio emulation - JP. We must try to parse the incoming
1096 		 * data and try to find the two characters that contain the
1097 		 * port number. Then we redirect an udp port and replace the
1098 		 * number with the real port we got.
1099 		 *
1100 		 * The 1.0 beta versions of the player are not supported
1101 		 * any more.
1102 		 *
1103 		 * A typical packet for player version 1.0 (release version):
1104 		 *
1105 		 * 0000:50 4E 41 00 05
1106 		 * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 .....�..g�l�c..P
1107 		 * 0010:4E 43 4C 49 45 4E 54 20 31 30 31 20 41 4C 50 48 NCLIENT 101 ALPH
1108 		 * 0020:41 6C 00 00 52 00 17 72 61 66 69 6C 65 73 2F 76 Al..R..rafiles/v
1109 		 * 0030:6F 61 2F 65 6E 67 6C 69 73 68 5F 2E 72 61 79 42 oa/english_.rayB
1110 		 *
1111 		 * Now the port number 0x1BD7 is found at offset 0x04 of the
1112 		 * Now the port number 0x1BD7 is found at offset 0x04 of the
1113 		 * second packet. This time we received five bytes first and
1114 		 * then the rest. You never know how many bytes you get.
1115 		 *
1116 		 * A typical packet for player version 2.0 (beta):
1117 		 *
1118 		 * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA...........�.
1119 		 * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .gux�c..Win2.0.0
1120 		 * 0020:2E 35 6C 00 00 52 00 1C 72 61 66 69 6C 65 73 2F .5l..R..rafiles/
1121 		 * 0030:77 65 62 73 69 74 65 2F 32 30 72 65 6C 65 61 73 website/20releas
1122 		 * 0040:65 2E 72 61 79 53 00 00 06 36 42                e.rayS...6B
1123 		 *
1124 		 * Port number 0x1BC1 is found at offset 0x0d.
1125 		 *
1126 		 * This is just a horrible switch statement. Variable ra tells
1127 		 * us where we're going.
1128 		 */
1129 
1130 		bptr = m->m_data;
1131 		while (bptr < m->m_data + m->m_len) {
1132 			u_short p;
1133 			static int ra = 0;
1134 			char ra_tbl[4];
1135 
1136 			ra_tbl[0] = 0x50;
1137 			ra_tbl[1] = 0x4e;
1138 			ra_tbl[2] = 0x41;
1139 			ra_tbl[3] = 0;
1140 
1141 			switch (ra) {
1142 			 case 0:
1143 			 case 2:
1144 			 case 3:
1145 				if (*bptr++ != ra_tbl[ra]) {
1146 					ra = 0;
1147 					continue;
1148 				}
1149 				break;
1150 
1151 			 case 1:
1152 				/*
1153 				 * We may get 0x50 several times, ignore them
1154 				 */
1155 				if (*bptr == 0x50) {
1156 					ra = 1;
1157 					bptr++;
1158 					continue;
1159 				} else if (*bptr++ != ra_tbl[ra]) {
1160 					ra = 0;
1161 					continue;
1162 				}
1163 				break;
1164 
1165 			 case 4:
1166 				/*
1167 				 * skip version number
1168 				 */
1169 				bptr++;
1170 				break;
1171 
1172 			 case 5:
1173 				/*
1174 				 * The difference between versions 1.0 and
1175 				 * 2.0 is here. For future versions of
1176 				 * the player this may need to be modified.
1177 				 */
1178 				if (*(bptr + 1) == 0x02)
1179 				   bptr += 8;
1180 				else
1181 				   bptr += 4;
1182 				break;
1183 
1184 			 case 6:
1185 				/* This is the field containing the port
1186 				 * number that RA-player is listening to.
1187 				 */
1188 				lport = (((u_char*)bptr)[0] << 8)
1189 				+ ((u_char *)bptr)[1];
1190 				if (lport < 6970)
1191 				   lport += 256;   /* don't know why */
1192 				if (lport < 6970 || lport > 7170)
1193 				   return 1;       /* failed */
1194 
1195 				/* try to get udp port between 6970 - 7170 */
1196 				for (p = 6970; p < 7071; p++) {
1197 					if (udp_listen( htons(p),
1198 						       so->so_laddr.s_addr,
1199 						       htons(lport),
1200 						       SS_FACCEPTONCE)) {
1201 						break;
1202 					}
1203 				}
1204 				if (p == 7071)
1205 				   p = 0;
1206 				*(u_char *)bptr++ = (p >> 8) & 0xff;
1207 				*(u_char *)bptr++ = p & 0xff;
1208 				ra = 0;
1209 				return 1;   /* port redirected, we're done */
1210 				break;
1211 
1212 			 default:
1213 				ra = 0;
1214 			}
1215 			ra++;
1216 		}
1217 		return 1;
1218 
1219 	 default:
1220 		/* Ooops, not emulated, won't call tcp_emu again */
1221 		so->so_emu = 0;
1222 		return 1;
1223 	}
1224 }
1225 
1226 /*
1227  * Do misc. config of SLiRP while its running.
1228  * Return 0 if this connections is to be closed, 1 otherwise,
1229  * return 2 if this is a command-line connection
1230  */
1231 int
tcp_ctl(struct socket * so)1232 tcp_ctl(struct socket *so)
1233 {
1234 	struct sbuf *sb = &so->so_snd;
1235 	int command;
1236  	struct ex_list *ex_ptr;
1237 	int do_pty;
1238         //	struct socket *tmpso;
1239 
1240 	DEBUG_CALL("tcp_ctl");
1241 	DEBUG_ARG("so = %lx", (long )so);
1242 
1243 #if 0
1244 	/*
1245 	 * Check if they're authorised
1246 	 */
1247 	if (ctl_addr.s_addr && (ctl_addr.s_addr == -1 || (so->so_laddr.s_addr != ctl_addr.s_addr))) {
1248 		sb->sb_cc = sprintf(sb->sb_wptr,"Error: Permission denied.\r\n");
1249 		sb->sb_wptr += sb->sb_cc;
1250 		return 0;
1251 	}
1252 #endif
1253 	command = (ntohl(so->so_faddr.s_addr) & 0xff);
1254 
1255 	switch(command) {
1256 	default: /* Check for exec's */
1257 
1258 		/*
1259 		 * Check if it's pty_exec
1260 		 */
1261 		for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
1262 			if (ex_ptr->ex_fport == so->so_fport &&
1263 			    command == ex_ptr->ex_addr) {
1264 				if (ex_ptr->ex_pty == 3) {
1265 					so->s = -1;
1266 					so->extra = (void *)ex_ptr->ex_exec;
1267 					return 1;
1268 				}
1269 				do_pty = ex_ptr->ex_pty;
1270 				goto do_exec;
1271 			}
1272 		}
1273 
1274 		/*
1275 		 * Nothing bound..
1276 		 */
1277 		/* tcp_fconnect(so); */
1278 
1279 		/* FALLTHROUGH */
1280 	case CTL_ALIAS:
1281           sb->sb_cc = snprintf(sb->sb_wptr, sb->sb_datalen - (sb->sb_wptr - sb->sb_data),
1282                                "Error: No application configured.\r\n");
1283 	  sb->sb_wptr += sb->sb_cc;
1284 	  return(0);
1285 
1286 	do_exec:
1287 		DEBUG_MISC((dfd, " executing %s \n",ex_ptr->ex_exec));
1288 		return(fork_exec(so, ex_ptr->ex_exec, do_pty));
1289 
1290 #if 0
1291 	case CTL_CMD:
1292 	   for (tmpso = tcb.so_next; tmpso != &tcb; tmpso = tmpso->so_next) {
1293 	     if (tmpso->so_emu == EMU_CTL &&
1294 		 !(tmpso->so_tcpcb?
1295 		   (tmpso->so_tcpcb->t_state & (TCPS_TIME_WAIT|TCPS_LAST_ACK))
1296 		   :0)) {
1297 	       /* Ooops, control connection already active */
1298 	       sb->sb_cc = sprintf(sb->sb_wptr,"Sorry, already connected.\r\n");
1299 	       sb->sb_wptr += sb->sb_cc;
1300 	       return 0;
1301 	     }
1302 	   }
1303 	   so->so_emu = EMU_CTL;
1304 	   ctl_password_ok = 0;
1305 	   sb->sb_cc = sprintf(sb->sb_wptr, "Slirp command-line ready (type \"help\" for help).\r\nSlirp> ");
1306 	   sb->sb_wptr += sb->sb_cc;
1307 	   do_echo=-1;
1308 	   return(2);
1309 #endif
1310 	}
1311 }
1312