linux-user: stack_base is now mandatory on all targets
[qemu.git] / slirp / tcp_subr.c
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
51 tcp_init(Slirp *slirp)
52 {
53 slirp->tcp_iss = 1; /* wrong */
54 slirp->tcb.so_next = slirp->tcb.so_prev = &slirp->tcb;
55 slirp->tcp_last_so = &slirp->tcb;
56 }
57
58 /*
59 * Create template to be used to send tcp packets on a connection.
60 * Call after host entry created, fills
61 * in a skeletal tcp/ip header, minimizing the amount of work
62 * necessary when the connection is used.
63 */
64 void
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
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(tp->t_socket->slirp)) == NULL)
121 return;
122 tlen = 0;
123 m->m_data += IF_MAXLINKHDR;
124 *mtod(m, struct tcpiphdr *) = *ti;
125 ti = mtod(m, struct tcpiphdr *);
126 flags = TH_ACK;
127 } else {
128 /*
129 * ti points into m so the next line is just making
130 * the mbuf point to ti
131 */
132 m->m_data = (caddr_t)ti;
133
134 m->m_len = sizeof (struct tcpiphdr);
135 tlen = 0;
136 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
137 xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, uint32_t);
138 xchg(ti->ti_dport, ti->ti_sport, uint16_t);
139 #undef xchg
140 }
141 ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen));
142 tlen += sizeof (struct tcpiphdr);
143 m->m_len = tlen;
144
145 ti->ti_mbuf = NULL;
146 ti->ti_x1 = 0;
147 ti->ti_seq = htonl(seq);
148 ti->ti_ack = htonl(ack);
149 ti->ti_x2 = 0;
150 ti->ti_off = sizeof (struct tcphdr) >> 2;
151 ti->ti_flags = flags;
152 if (tp)
153 ti->ti_win = htons((uint16_t) (win >> tp->rcv_scale));
154 else
155 ti->ti_win = htons((uint16_t)win);
156 ti->ti_urp = 0;
157 ti->ti_sum = 0;
158 ti->ti_sum = cksum(m, tlen);
159 ((struct ip *)ti)->ip_len = tlen;
160
161 if(flags & TH_RST)
162 ((struct ip *)ti)->ip_ttl = MAXTTL;
163 else
164 ((struct ip *)ti)->ip_ttl = IPDEFTTL;
165
166 (void) ip_output((struct socket *)0, m);
167 }
168
169 /*
170 * Create a new TCP control block, making an
171 * empty reassembly queue and hooking it to the argument
172 * protocol control block.
173 */
174 struct tcpcb *
175 tcp_newtcpcb(struct socket *so)
176 {
177 register struct tcpcb *tp;
178
179 tp = (struct tcpcb *)malloc(sizeof(*tp));
180 if (tp == NULL)
181 return ((struct tcpcb *)0);
182
183 memset((char *) tp, 0, sizeof(struct tcpcb));
184 tp->seg_next = tp->seg_prev = (struct tcpiphdr*)tp;
185 tp->t_maxseg = TCP_MSS;
186
187 tp->t_flags = TCP_DO_RFC1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0;
188 tp->t_socket = so;
189
190 /*
191 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
192 * rtt estimate. Set rttvar so that srtt + 2 * rttvar gives
193 * reasonable initial retransmit time.
194 */
195 tp->t_srtt = TCPTV_SRTTBASE;
196 tp->t_rttvar = TCPTV_SRTTDFLT << 2;
197 tp->t_rttmin = TCPTV_MIN;
198
199 TCPT_RANGESET(tp->t_rxtcur,
200 ((TCPTV_SRTTBASE >> 2) + (TCPTV_SRTTDFLT << 2)) >> 1,
201 TCPTV_MIN, TCPTV_REXMTMAX);
202
203 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
204 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
205 tp->t_state = TCPS_CLOSED;
206
207 so->so_tcpcb = tp;
208
209 return (tp);
210 }
211
212 /*
213 * Drop a TCP connection, reporting
214 * the specified error. If connection is synchronized,
215 * then send a RST to peer.
216 */
217 struct tcpcb *tcp_drop(struct tcpcb *tp, int err)
218 {
219 DEBUG_CALL("tcp_drop");
220 DEBUG_ARG("tp = %lx", (long)tp);
221 DEBUG_ARG("errno = %d", errno);
222
223 if (TCPS_HAVERCVDSYN(tp->t_state)) {
224 tp->t_state = TCPS_CLOSED;
225 (void) tcp_output(tp);
226 }
227 return (tcp_close(tp));
228 }
229
230 /*
231 * Close a TCP control block:
232 * discard all space held by the tcp
233 * discard internet protocol block
234 * wake up any sleepers
235 */
236 struct tcpcb *
237 tcp_close(struct tcpcb *tp)
238 {
239 register struct tcpiphdr *t;
240 struct socket *so = tp->t_socket;
241 Slirp *slirp = so->slirp;
242 register struct mbuf *m;
243
244 DEBUG_CALL("tcp_close");
245 DEBUG_ARG("tp = %lx", (long )tp);
246
247 /* free the reassembly queue, if any */
248 t = tcpfrag_list_first(tp);
249 while (!tcpfrag_list_end(t, tp)) {
250 t = tcpiphdr_next(t);
251 m = tcpiphdr_prev(t)->ti_mbuf;
252 remque(tcpiphdr2qlink(tcpiphdr_prev(t)));
253 m_free(m);
254 }
255 free(tp);
256 so->so_tcpcb = NULL;
257 /* clobber input socket cache if we're closing the cached connection */
258 if (so == slirp->tcp_last_so)
259 slirp->tcp_last_so = &slirp->tcb;
260 closesocket(so->s);
261 sbfree(&so->so_rcv);
262 sbfree(&so->so_snd);
263 sofree(so);
264 return ((struct tcpcb *)0);
265 }
266
267 /*
268 * TCP protocol interface to socket abstraction.
269 */
270
271 /*
272 * User issued close, and wish to trail through shutdown states:
273 * if never received SYN, just forget it. If got a SYN from peer,
274 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
275 * If already got a FIN from peer, then almost done; go to LAST_ACK
276 * state. In all other cases, have already sent FIN to peer (e.g.
277 * after PRU_SHUTDOWN), and just have to play tedious game waiting
278 * for peer to send FIN or not respond to keep-alives, etc.
279 * We can let the user exit from the close as soon as the FIN is acked.
280 */
281 void
282 tcp_sockclosed(struct tcpcb *tp)
283 {
284
285 DEBUG_CALL("tcp_sockclosed");
286 DEBUG_ARG("tp = %lx", (long)tp);
287
288 switch (tp->t_state) {
289
290 case TCPS_CLOSED:
291 case TCPS_LISTEN:
292 case TCPS_SYN_SENT:
293 tp->t_state = TCPS_CLOSED;
294 tp = tcp_close(tp);
295 break;
296
297 case TCPS_SYN_RECEIVED:
298 case TCPS_ESTABLISHED:
299 tp->t_state = TCPS_FIN_WAIT_1;
300 break;
301
302 case TCPS_CLOSE_WAIT:
303 tp->t_state = TCPS_LAST_ACK;
304 break;
305 }
306 if (tp)
307 tcp_output(tp);
308 }
309
310 /*
311 * Connect to a host on the Internet
312 * Called by tcp_input
313 * Only do a connect, the tcp fields will be set in tcp_input
314 * return 0 if there's a result of the connect,
315 * else return -1 means we're still connecting
316 * The return value is almost always -1 since the socket is
317 * nonblocking. Connect returns after the SYN is sent, and does
318 * not wait for ACK+SYN.
319 */
320 int tcp_fconnect(struct socket *so)
321 {
322 Slirp *slirp = so->slirp;
323 int ret=0;
324
325 DEBUG_CALL("tcp_fconnect");
326 DEBUG_ARG("so = %lx", (long )so);
327
328 if( (ret = so->s = qemu_socket(AF_INET,SOCK_STREAM,0)) >= 0) {
329 int opt, s=so->s;
330 struct sockaddr_in addr;
331
332 fd_nonblock(s);
333 opt = 1;
334 setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(opt ));
335 opt = 1;
336 setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(opt ));
337
338 addr.sin_family = AF_INET;
339 if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
340 slirp->vnetwork_addr.s_addr) {
341 /* It's an alias */
342 if (so->so_faddr.s_addr == slirp->vnameserver_addr.s_addr) {
343 if (get_dns_addr(&addr.sin_addr) < 0)
344 addr.sin_addr = loopback_addr;
345 } else {
346 addr.sin_addr = loopback_addr;
347 }
348 } else
349 addr.sin_addr = so->so_faddr;
350 addr.sin_port = so->so_fport;
351
352 DEBUG_MISC((dfd, " connect()ing, addr.sin_port=%d, "
353 "addr.sin_addr.s_addr=%.16s\n",
354 ntohs(addr.sin_port), inet_ntoa(addr.sin_addr)));
355 /* We don't care what port we get */
356 ret = connect(s,(struct sockaddr *)&addr,sizeof (addr));
357
358 /*
359 * If it's not in progress, it failed, so we just return 0,
360 * without clearing SS_NOFDREF
361 */
362 soisfconnecting(so);
363 }
364
365 return(ret);
366 }
367
368 /*
369 * Accept the socket and connect to the local-host
370 *
371 * We have a problem. The correct thing to do would be
372 * to first connect to the local-host, and only if the
373 * connection is accepted, then do an accept() here.
374 * But, a) we need to know who's trying to connect
375 * to the socket to be able to SYN the local-host, and
376 * b) we are already connected to the foreign host by
377 * the time it gets to accept(), so... We simply accept
378 * here and SYN the local-host.
379 */
380 void
381 tcp_connect(struct socket *inso)
382 {
383 Slirp *slirp = inso->slirp;
384 struct socket *so;
385 struct sockaddr_in addr;
386 socklen_t addrlen = sizeof(struct sockaddr_in);
387 struct tcpcb *tp;
388 int s, opt;
389
390 DEBUG_CALL("tcp_connect");
391 DEBUG_ARG("inso = %lx", (long)inso);
392
393 /*
394 * If it's an SS_ACCEPTONCE socket, no need to socreate()
395 * another socket, just use the accept() socket.
396 */
397 if (inso->so_state & SS_FACCEPTONCE) {
398 /* FACCEPTONCE already have a tcpcb */
399 so = inso;
400 } else {
401 if ((so = socreate(slirp)) == NULL) {
402 /* If it failed, get rid of the pending connection */
403 closesocket(accept(inso->s,(struct sockaddr *)&addr,&addrlen));
404 return;
405 }
406 if (tcp_attach(so) < 0) {
407 free(so); /* NOT sofree */
408 return;
409 }
410 so->so_laddr = inso->so_laddr;
411 so->so_lport = inso->so_lport;
412 }
413
414 (void) tcp_mss(sototcpcb(so), 0);
415
416 if ((s = accept(inso->s,(struct sockaddr *)&addr,&addrlen)) < 0) {
417 tcp_close(sototcpcb(so)); /* This will sofree() as well */
418 return;
419 }
420 fd_nonblock(s);
421 opt = 1;
422 setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
423 opt = 1;
424 setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
425 opt = 1;
426 setsockopt(s,IPPROTO_TCP,TCP_NODELAY,(char *)&opt,sizeof(int));
427
428 so->so_fport = addr.sin_port;
429 so->so_faddr = addr.sin_addr;
430 /* Translate connections from localhost to the real hostname */
431 if (so->so_faddr.s_addr == 0 || so->so_faddr.s_addr == loopback_addr.s_addr)
432 so->so_faddr = slirp->vhost_addr;
433
434 /* Close the accept() socket, set right state */
435 if (inso->so_state & SS_FACCEPTONCE) {
436 closesocket(so->s); /* If we only accept once, close the accept() socket */
437 so->so_state = SS_NOFDREF; /* Don't select it yet, even though we have an FD */
438 /* if it's not FACCEPTONCE, it's already NOFDREF */
439 }
440 so->s = s;
441 so->so_state |= SS_INCOMING;
442
443 so->so_iptos = tcp_tos(so);
444 tp = sototcpcb(so);
445
446 tcp_template(tp);
447
448 tp->t_state = TCPS_SYN_SENT;
449 tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
450 tp->iss = slirp->tcp_iss;
451 slirp->tcp_iss += TCP_ISSINCR/2;
452 tcp_sendseqinit(tp);
453 tcp_output(tp);
454 }
455
456 /*
457 * Attach a TCPCB to a socket.
458 */
459 int
460 tcp_attach(struct socket *so)
461 {
462 if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
463 return -1;
464
465 insque(so, &so->slirp->tcb);
466
467 return 0;
468 }
469
470 /*
471 * Set the socket's type of service field
472 */
473 static const struct tos_t tcptos[] = {
474 {0, 20, IPTOS_THROUGHPUT, 0}, /* ftp data */
475 {21, 21, IPTOS_LOWDELAY, EMU_FTP}, /* ftp control */
476 {0, 23, IPTOS_LOWDELAY, 0}, /* telnet */
477 {0, 80, IPTOS_THROUGHPUT, 0}, /* WWW */
478 {0, 513, IPTOS_LOWDELAY, EMU_RLOGIN|EMU_NOCONNECT}, /* rlogin */
479 {0, 514, IPTOS_LOWDELAY, EMU_RSH|EMU_NOCONNECT}, /* shell */
480 {0, 544, IPTOS_LOWDELAY, EMU_KSH}, /* kshell */
481 {0, 543, IPTOS_LOWDELAY, 0}, /* klogin */
482 {0, 6667, IPTOS_THROUGHPUT, EMU_IRC}, /* IRC */
483 {0, 6668, IPTOS_THROUGHPUT, EMU_IRC}, /* IRC undernet */
484 {0, 7070, IPTOS_LOWDELAY, EMU_REALAUDIO }, /* RealAudio control */
485 {0, 113, IPTOS_LOWDELAY, EMU_IDENT }, /* identd protocol */
486 {0, 0, 0, 0}
487 };
488
489 static struct emu_t *tcpemu = NULL;
490
491 /*
492 * Return TOS according to the above table
493 */
494 uint8_t
495 tcp_tos(struct socket *so)
496 {
497 int i = 0;
498 struct emu_t *emup;
499
500 while(tcptos[i].tos) {
501 if ((tcptos[i].fport && (ntohs(so->so_fport) == tcptos[i].fport)) ||
502 (tcptos[i].lport && (ntohs(so->so_lport) == tcptos[i].lport))) {
503 so->so_emu = tcptos[i].emu;
504 return tcptos[i].tos;
505 }
506 i++;
507 }
508
509 /* Nope, lets see if there's a user-added one */
510 for (emup = tcpemu; emup; emup = emup->next) {
511 if ((emup->fport && (ntohs(so->so_fport) == emup->fport)) ||
512 (emup->lport && (ntohs(so->so_lport) == emup->lport))) {
513 so->so_emu = emup->emu;
514 return emup->tos;
515 }
516 }
517
518 return 0;
519 }
520
521 /*
522 * Emulate programs that try and connect to us
523 * This includes ftp (the data connection is
524 * initiated by the server) and IRC (DCC CHAT and
525 * DCC SEND) for now
526 *
527 * NOTE: It's possible to crash SLiRP by sending it
528 * unstandard strings to emulate... if this is a problem,
529 * more checks are needed here
530 *
531 * XXX Assumes the whole command came in one packet
532 *
533 * XXX Some ftp clients will have their TOS set to
534 * LOWDELAY and so Nagel will kick in. Because of this,
535 * we'll get the first letter, followed by the rest, so
536 * we simply scan for ORT instead of PORT...
537 * DCC doesn't have this problem because there's other stuff
538 * in the packet before the DCC command.
539 *
540 * Return 1 if the mbuf m is still valid and should be
541 * sbappend()ed
542 *
543 * NOTE: if you return 0 you MUST m_free() the mbuf!
544 */
545 int
546 tcp_emu(struct socket *so, struct mbuf *m)
547 {
548 Slirp *slirp = so->slirp;
549 u_int n1, n2, n3, n4, n5, n6;
550 char buff[257];
551 uint32_t laddr;
552 u_int lport;
553 char *bptr;
554
555 DEBUG_CALL("tcp_emu");
556 DEBUG_ARG("so = %lx", (long)so);
557 DEBUG_ARG("m = %lx", (long)m);
558
559 switch(so->so_emu) {
560 int x, i;
561
562 case EMU_IDENT:
563 /*
564 * Identification protocol as per rfc-1413
565 */
566
567 {
568 struct socket *tmpso;
569 struct sockaddr_in addr;
570 socklen_t addrlen = sizeof(struct sockaddr_in);
571 struct sbuf *so_rcv = &so->so_rcv;
572
573 memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
574 so_rcv->sb_wptr += m->m_len;
575 so_rcv->sb_rptr += m->m_len;
576 m->m_data[m->m_len] = 0; /* NULL terminate */
577 if (strchr(m->m_data, '\r') || strchr(m->m_data, '\n')) {
578 if (sscanf(so_rcv->sb_data, "%u%*[ ,]%u", &n1, &n2) == 2) {
579 HTONS(n1);
580 HTONS(n2);
581 /* n2 is the one on our host */
582 for (tmpso = slirp->tcb.so_next;
583 tmpso != &slirp->tcb;
584 tmpso = tmpso->so_next) {
585 if (tmpso->so_laddr.s_addr == so->so_laddr.s_addr &&
586 tmpso->so_lport == n2 &&
587 tmpso->so_faddr.s_addr == so->so_faddr.s_addr &&
588 tmpso->so_fport == n1) {
589 if (getsockname(tmpso->s,
590 (struct sockaddr *)&addr, &addrlen) == 0)
591 n2 = ntohs(addr.sin_port);
592 break;
593 }
594 }
595 }
596 so_rcv->sb_cc = snprintf(so_rcv->sb_data,
597 so_rcv->sb_datalen,
598 "%d,%d\r\n", n1, n2);
599 so_rcv->sb_rptr = so_rcv->sb_data;
600 so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
601 }
602 m_free(m);
603 return 0;
604 }
605
606 case EMU_FTP: /* ftp */
607 *(m->m_data+m->m_len) = 0; /* NUL terminate for strstr */
608 if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
609 /*
610 * Need to emulate the PORT command
611 */
612 x = sscanf(bptr, "ORT %u,%u,%u,%u,%u,%u\r\n%256[^\177]",
613 &n1, &n2, &n3, &n4, &n5, &n6, buff);
614 if (x < 6)
615 return 1;
616
617 laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
618 lport = htons((n5 << 8) | (n6));
619
620 if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
621 lport, SS_FACCEPTONCE)) == NULL) {
622 return 1;
623 }
624 n6 = ntohs(so->so_fport);
625
626 n5 = (n6 >> 8) & 0xff;
627 n6 &= 0xff;
628
629 laddr = ntohl(so->so_faddr.s_addr);
630
631 n1 = ((laddr >> 24) & 0xff);
632 n2 = ((laddr >> 16) & 0xff);
633 n3 = ((laddr >> 8) & 0xff);
634 n4 = (laddr & 0xff);
635
636 m->m_len = bptr - m->m_data; /* Adjust length */
637 m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
638 "ORT %d,%d,%d,%d,%d,%d\r\n%s",
639 n1, n2, n3, n4, n5, n6, x==7?buff:"");
640 return 1;
641 } else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
642 /*
643 * Need to emulate the PASV response
644 */
645 x = sscanf(bptr, "27 Entering Passive Mode (%u,%u,%u,%u,%u,%u)\r\n%256[^\177]",
646 &n1, &n2, &n3, &n4, &n5, &n6, buff);
647 if (x < 6)
648 return 1;
649
650 laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
651 lport = htons((n5 << 8) | (n6));
652
653 if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
654 lport, SS_FACCEPTONCE)) == NULL) {
655 return 1;
656 }
657 n6 = ntohs(so->so_fport);
658
659 n5 = (n6 >> 8) & 0xff;
660 n6 &= 0xff;
661
662 laddr = ntohl(so->so_faddr.s_addr);
663
664 n1 = ((laddr >> 24) & 0xff);
665 n2 = ((laddr >> 16) & 0xff);
666 n3 = ((laddr >> 8) & 0xff);
667 n4 = (laddr & 0xff);
668
669 m->m_len = bptr - m->m_data; /* Adjust length */
670 m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
671 "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
672 n1, n2, n3, n4, n5, n6, x==7?buff:"");
673
674 return 1;
675 }
676
677 return 1;
678
679 case EMU_KSH:
680 /*
681 * The kshell (Kerberos rsh) and shell services both pass
682 * a local port port number to carry signals to the server
683 * and stderr to the client. It is passed at the beginning
684 * of the connection as a NUL-terminated decimal ASCII string.
685 */
686 so->so_emu = 0;
687 for (lport = 0, i = 0; i < m->m_len-1; ++i) {
688 if (m->m_data[i] < '0' || m->m_data[i] > '9')
689 return 1; /* invalid number */
690 lport *= 10;
691 lport += m->m_data[i] - '0';
692 }
693 if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
694 (so = tcp_listen(slirp, INADDR_ANY, 0, so->so_laddr.s_addr,
695 htons(lport), SS_FACCEPTONCE)) != NULL)
696 m->m_len = snprintf(m->m_data, m->m_hdr.mh_size, "%d",
697 ntohs(so->so_fport)) + 1;
698 return 1;
699
700 case EMU_IRC:
701 /*
702 * Need to emulate DCC CHAT, DCC SEND and DCC MOVE
703 */
704 *(m->m_data+m->m_len) = 0; /* NULL terminate the string for strstr */
705 if ((bptr = (char *)strstr(m->m_data, "DCC")) == NULL)
706 return 1;
707
708 /* The %256s is for the broken mIRC */
709 if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) {
710 if ((so = tcp_listen(slirp, INADDR_ANY, 0,
711 htonl(laddr), htons(lport),
712 SS_FACCEPTONCE)) == NULL) {
713 return 1;
714 }
715 m->m_len = bptr - m->m_data; /* Adjust length */
716 m->m_len += snprintf(bptr, m->m_hdr.mh_size,
717 "DCC CHAT chat %lu %u%c\n",
718 (unsigned long)ntohl(so->so_faddr.s_addr),
719 ntohs(so->so_fport), 1);
720 } else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
721 if ((so = tcp_listen(slirp, INADDR_ANY, 0,
722 htonl(laddr), htons(lport),
723 SS_FACCEPTONCE)) == NULL) {
724 return 1;
725 }
726 m->m_len = bptr - m->m_data; /* Adjust length */
727 m->m_len += snprintf(bptr, m->m_hdr.mh_size,
728 "DCC SEND %s %lu %u %u%c\n", buff,
729 (unsigned long)ntohl(so->so_faddr.s_addr),
730 ntohs(so->so_fport), n1, 1);
731 } else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
732 if ((so = tcp_listen(slirp, INADDR_ANY, 0,
733 htonl(laddr), htons(lport),
734 SS_FACCEPTONCE)) == NULL) {
735 return 1;
736 }
737 m->m_len = bptr - m->m_data; /* Adjust length */
738 m->m_len += snprintf(bptr, m->m_hdr.mh_size,
739 "DCC MOVE %s %lu %u %u%c\n", buff,
740 (unsigned long)ntohl(so->so_faddr.s_addr),
741 ntohs(so->so_fport), n1, 1);
742 }
743 return 1;
744
745 case EMU_REALAUDIO:
746 /*
747 * RealAudio emulation - JP. We must try to parse the incoming
748 * data and try to find the two characters that contain the
749 * port number. Then we redirect an udp port and replace the
750 * number with the real port we got.
751 *
752 * The 1.0 beta versions of the player are not supported
753 * any more.
754 *
755 * A typical packet for player version 1.0 (release version):
756 *
757 * 0000:50 4E 41 00 05
758 * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 ........g.l.c..P
759 * 0010:4E 43 4C 49 45 4E 54 20 31 30 31 20 41 4C 50 48 NCLIENT 101 ALPH
760 * 0020:41 6C 00 00 52 00 17 72 61 66 69 6C 65 73 2F 76 Al..R..rafiles/v
761 * 0030:6F 61 2F 65 6E 67 6C 69 73 68 5F 2E 72 61 79 42 oa/english_.rayB
762 *
763 * Now the port number 0x1BD7 is found at offset 0x04 of the
764 * Now the port number 0x1BD7 is found at offset 0x04 of the
765 * second packet. This time we received five bytes first and
766 * then the rest. You never know how many bytes you get.
767 *
768 * A typical packet for player version 2.0 (beta):
769 *
770 * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA.............
771 * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .gux.c..Win2.0.0
772 * 0020:2E 35 6C 00 00 52 00 1C 72 61 66 69 6C 65 73 2F .5l..R..rafiles/
773 * 0030:77 65 62 73 69 74 65 2F 32 30 72 65 6C 65 61 73 website/20releas
774 * 0040:65 2E 72 61 79 53 00 00 06 36 42 e.rayS...6B
775 *
776 * Port number 0x1BC1 is found at offset 0x0d.
777 *
778 * This is just a horrible switch statement. Variable ra tells
779 * us where we're going.
780 */
781
782 bptr = m->m_data;
783 while (bptr < m->m_data + m->m_len) {
784 u_short p;
785 static int ra = 0;
786 char ra_tbl[4];
787
788 ra_tbl[0] = 0x50;
789 ra_tbl[1] = 0x4e;
790 ra_tbl[2] = 0x41;
791 ra_tbl[3] = 0;
792
793 switch (ra) {
794 case 0:
795 case 2:
796 case 3:
797 if (*bptr++ != ra_tbl[ra]) {
798 ra = 0;
799 continue;
800 }
801 break;
802
803 case 1:
804 /*
805 * We may get 0x50 several times, ignore them
806 */
807 if (*bptr == 0x50) {
808 ra = 1;
809 bptr++;
810 continue;
811 } else if (*bptr++ != ra_tbl[ra]) {
812 ra = 0;
813 continue;
814 }
815 break;
816
817 case 4:
818 /*
819 * skip version number
820 */
821 bptr++;
822 break;
823
824 case 5:
825 /*
826 * The difference between versions 1.0 and
827 * 2.0 is here. For future versions of
828 * the player this may need to be modified.
829 */
830 if (*(bptr + 1) == 0x02)
831 bptr += 8;
832 else
833 bptr += 4;
834 break;
835
836 case 6:
837 /* This is the field containing the port
838 * number that RA-player is listening to.
839 */
840 lport = (((u_char*)bptr)[0] << 8)
841 + ((u_char *)bptr)[1];
842 if (lport < 6970)
843 lport += 256; /* don't know why */
844 if (lport < 6970 || lport > 7170)
845 return 1; /* failed */
846
847 /* try to get udp port between 6970 - 7170 */
848 for (p = 6970; p < 7071; p++) {
849 if (udp_listen(slirp, INADDR_ANY,
850 htons(p),
851 so->so_laddr.s_addr,
852 htons(lport),
853 SS_FACCEPTONCE)) {
854 break;
855 }
856 }
857 if (p == 7071)
858 p = 0;
859 *(u_char *)bptr++ = (p >> 8) & 0xff;
860 *(u_char *)bptr = p & 0xff;
861 ra = 0;
862 return 1; /* port redirected, we're done */
863 break;
864
865 default:
866 ra = 0;
867 }
868 ra++;
869 }
870 return 1;
871
872 default:
873 /* Ooops, not emulated, won't call tcp_emu again */
874 so->so_emu = 0;
875 return 1;
876 }
877 }
878
879 /*
880 * Do misc. config of SLiRP while its running.
881 * Return 0 if this connections is to be closed, 1 otherwise,
882 * return 2 if this is a command-line connection
883 */
884 int tcp_ctl(struct socket *so)
885 {
886 Slirp *slirp = so->slirp;
887 struct sbuf *sb = &so->so_snd;
888 struct ex_list *ex_ptr;
889 int do_pty;
890
891 DEBUG_CALL("tcp_ctl");
892 DEBUG_ARG("so = %lx", (long )so);
893
894 if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr) {
895 /* Check if it's pty_exec */
896 for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
897 if (ex_ptr->ex_fport == so->so_fport &&
898 so->so_faddr.s_addr == ex_ptr->ex_addr.s_addr) {
899 if (ex_ptr->ex_pty == 3) {
900 so->s = -1;
901 so->extra = (void *)ex_ptr->ex_exec;
902 return 1;
903 }
904 do_pty = ex_ptr->ex_pty;
905 DEBUG_MISC((dfd, " executing %s\n", ex_ptr->ex_exec));
906 return fork_exec(so, ex_ptr->ex_exec, do_pty);
907 }
908 }
909 }
910 sb->sb_cc =
911 snprintf(sb->sb_wptr, sb->sb_datalen - (sb->sb_wptr - sb->sb_data),
912 "Error: No application configured.\r\n");
913 sb->sb_wptr += sb->sb_cc;
914 return 0;
915 }