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 #include "tcp2unix.h"
43
44 /* patchable/settable parameters for tcp */
45 /* Don't do rfc1323 performance enhancements */
46 #define TCP_DO_RFC1323 0
47
48 /*
49 * Tcp initialization
50 */
51 void
tcp_init(Slirp * slirp)52 tcp_init(Slirp *slirp)
53 {
54 slirp->tcp_iss = 1; /* wrong */
55 slirp->tcb.so_next = slirp->tcb.so_prev = &slirp->tcb;
56 slirp->tcp_last_so = &slirp->tcb;
57 }
58
59 /*
60 * Create template to be used to send tcp packets on a connection.
61 * Call after host entry created, fills
62 * in a skeletal tcp/ip header, minimizing the amount of work
63 * necessary when the connection is used.
64 */
65 void
tcp_template(struct tcpcb * tp)66 tcp_template(struct tcpcb *tp)
67 {
68 struct socket *so = tp->t_socket;
69 register struct tcpiphdr *n = &tp->t_template;
70
71 n->ti_mbuf = NULL;
72 n->ti_x1 = 0;
73 n->ti_pr = IPPROTO_TCP;
74 n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip));
75 n->ti_src = so->so_faddr;
76 n->ti_dst = so->so_laddr;
77 n->ti_sport = so->so_fport;
78 n->ti_dport = so->so_lport;
79
80 n->ti_seq = 0;
81 n->ti_ack = 0;
82 n->ti_x2 = 0;
83 n->ti_off = 5;
84 n->ti_flags = 0;
85 n->ti_win = 0;
86 n->ti_sum = 0;
87 n->ti_urp = 0;
88 }
89
90 /*
91 * Send a single message to the TCP at address specified by
92 * the given TCP/IP header. If m == 0, then we make a copy
93 * of the tcpiphdr at ti and send directly to the addressed host.
94 * This is used to force keep alive messages out using the TCP
95 * template for a connection tp->t_template. If flags are given
96 * then we send a message back to the TCP which originated the
97 * segment ti, and discard the mbuf containing it and any other
98 * attached mbufs.
99 *
100 * In any case the ack and sequence number of the transmitted
101 * segment are as specified by the parameters.
102 */
103 void
tcp_respond(struct tcpcb * tp,struct tcpiphdr * ti,struct mbuf * m,tcp_seq ack,tcp_seq seq,int flags)104 tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
105 tcp_seq ack, tcp_seq seq, int flags)
106 {
107 register int tlen;
108 int win = 0;
109
110 DEBUG_CALL("tcp_respond");
111 DEBUG_ARG("tp = %lx", (long)tp);
112 DEBUG_ARG("ti = %lx", (long)ti);
113 DEBUG_ARG("m = %lx", (long)m);
114 DEBUG_ARG("ack = %u", ack);
115 DEBUG_ARG("seq = %u", seq);
116 DEBUG_ARG("flags = %x", flags);
117
118 if (tp)
119 win = sbspace(&tp->t_socket->so_rcv);
120 if (m == NULL) {
121 if ((m = m_get(tp->t_socket->slirp)) == NULL)
122 return;
123 tlen = 0;
124 m->m_data += IF_MAXLINKHDR;
125 *mtod(m, struct tcpiphdr *) = *ti;
126 ti = mtod(m, struct tcpiphdr *);
127 flags = TH_ACK;
128 } else {
129 /*
130 * ti points into m so the next line is just making
131 * the mbuf point to ti
132 */
133 m->m_data = (caddr_t)ti;
134
135 m->m_len = sizeof (struct tcpiphdr);
136 tlen = 0;
137 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
138 xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, u_int32_t);
139 xchg(ti->ti_dport, ti->ti_sport, u_int16_t);
140 #undef xchg
141 }
142 ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen));
143 tlen += sizeof (struct tcpiphdr);
144 m->m_len = tlen;
145
146 ti->ti_mbuf = NULL;
147 ti->ti_x1 = 0;
148 ti->ti_seq = htonl(seq);
149 ti->ti_ack = htonl(ack);
150 ti->ti_x2 = 0;
151 ti->ti_off = sizeof (struct tcphdr) >> 2;
152 ti->ti_flags = flags;
153 if (tp)
154 ti->ti_win = htons((u_int16_t) (win >> tp->rcv_scale));
155 else
156 ti->ti_win = htons((u_int16_t)win);
157 ti->ti_urp = 0;
158 ti->ti_sum = 0;
159 ti->ti_sum = cksum(m, tlen);
160 ((struct ip *)ti)->ip_len = tlen;
161
162 if(flags & TH_RST)
163 ((struct ip *)ti)->ip_ttl = MAXTTL;
164 else
165 ((struct ip *)ti)->ip_ttl = IPDEFTTL;
166
167 (void) ip_output((struct socket *)0, m);
168 }
169
170 /*
171 * Create a new TCP control block, making an
172 * empty reassembly queue and hooking it to the argument
173 * protocol control block.
174 */
175 struct tcpcb *
tcp_newtcpcb(struct socket * so)176 tcp_newtcpcb(struct socket *so)
177 {
178 register struct tcpcb *tp;
179
180 tp = (struct tcpcb *)malloc(sizeof(*tp));
181 if (tp == NULL)
182 return ((struct tcpcb *)0);
183
184 memset((char *) tp, 0, sizeof(struct tcpcb));
185 tp->seg_next = tp->seg_prev = (struct tcpiphdr*)tp;
186 tp->t_maxseg = TCP_MSS;
187
188 tp->t_flags = TCP_DO_RFC1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0;
189 tp->t_socket = so;
190
191 /*
192 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
193 * rtt estimate. Set rttvar so that srtt + 2 * rttvar gives
194 * reasonable initial retransmit time.
195 */
196 tp->t_srtt = TCPTV_SRTTBASE;
197 tp->t_rttvar = TCPTV_SRTTDFLT << 2;
198 tp->t_rttmin = TCPTV_MIN;
199
200 TCPT_RANGESET(tp->t_rxtcur,
201 ((TCPTV_SRTTBASE >> 2) + (TCPTV_SRTTDFLT << 2)) >> 1,
202 TCPTV_MIN, TCPTV_REXMTMAX);
203
204 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
205 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
206 tp->t_state = TCPS_CLOSED;
207
208 so->so_tcpcb = tp;
209
210 return (tp);
211 }
212
213 /*
214 * Drop a TCP connection, reporting
215 * the specified error. If connection is synchronized,
216 * then send a RST to peer.
217 */
tcp_drop(struct tcpcb * tp,int err)218 struct tcpcb *tcp_drop(struct tcpcb *tp, int err)
219 {
220 DEBUG_CALL("tcp_drop");
221 DEBUG_ARG("tp = %lx", (long)tp);
222 DEBUG_ARG("errno = %d", errno);
223
224 if (TCPS_HAVERCVDSYN(tp->t_state)) {
225 tp->t_state = TCPS_CLOSED;
226 (void) tcp_output(tp);
227 }
228 return (tcp_close(tp));
229 }
230
231 /*
232 * Close a TCP control block:
233 * discard all space held by the tcp
234 * discard internet protocol block
235 * wake up any sleepers
236 */
237 struct tcpcb *
tcp_close(struct tcpcb * tp)238 tcp_close(struct tcpcb *tp)
239 {
240 register struct tcpiphdr *t;
241 struct socket *so = tp->t_socket;
242 Slirp *slirp = so->slirp;
243 register struct mbuf *m;
244
245 DEBUG_CALL("tcp_close");
246 DEBUG_ARG("tp = %lx", (long )tp);
247
248 /* free the reassembly queue, if any */
249 t = tcpfrag_list_first(tp);
250 while (!tcpfrag_list_end(t, tp)) {
251 t = tcpiphdr_next(t);
252 m = tcpiphdr_prev(t)->ti_mbuf;
253 remque(tcpiphdr2qlink(tcpiphdr_prev(t)));
254 m_freem(m);
255 }
256 free(tp);
257 so->so_tcpcb = NULL;
258 /* clobber input socket cache if we're closing the cached connection */
259 if (so == slirp->tcp_last_so)
260 slirp->tcp_last_so = &slirp->tcb;
261 closesocket(so->s);
262 sbfree(&so->so_rcv);
263 sbfree(&so->so_snd);
264 sofree(so);
265 return ((struct tcpcb *)0);
266 }
267
268 /*
269 * TCP protocol interface to socket abstraction.
270 */
271
272 /*
273 * User issued close, and wish to trail through shutdown states:
274 * if never received SYN, just forget it. If got a SYN from peer,
275 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
276 * If already got a FIN from peer, then almost done; go to LAST_ACK
277 * state. In all other cases, have already sent FIN to peer (e.g.
278 * after PRU_SHUTDOWN), and just have to play tedious game waiting
279 * for peer to send FIN or not respond to keep-alives, etc.
280 * We can let the user exit from the close as soon as the FIN is acked.
281 */
282 void
tcp_sockclosed(struct tcpcb * tp)283 tcp_sockclosed(struct tcpcb *tp)
284 {
285
286 DEBUG_CALL("tcp_sockclosed");
287 DEBUG_ARG("tp = %lx", (long)tp);
288
289 switch (tp->t_state) {
290
291 case TCPS_CLOSED:
292 case TCPS_LISTEN:
293 case TCPS_SYN_SENT:
294 tp->t_state = TCPS_CLOSED;
295 tp = tcp_close(tp);
296 break;
297
298 case TCPS_SYN_RECEIVED:
299 case TCPS_ESTABLISHED:
300 tp->t_state = TCPS_FIN_WAIT_1;
301 break;
302
303 case TCPS_CLOSE_WAIT:
304 tp->t_state = TCPS_LAST_ACK;
305 break;
306 }
307 if (tp)
308 tcp_output(tp);
309 }
310
311 /*
312 * Connect to a host on the Internet
313 * Called by tcp_input
314 * Only do a connect, the tcp fields will be set in tcp_input
315 * return 0 if there's a result of the connect,
316 * else return -1 means we're still connecting
317 * The return value is almost always -1 since the socket is
318 * nonblocking. Connect returns after the SYN is sent, and does
319 * not wait for ACK+SYN.
320 */
tcp_fconnect(struct socket * so)321 int tcp_fconnect(struct socket *so)
322 {
323 Slirp *slirp = so->slirp;
324 int ret=0;
325 char *path;
326
327 DEBUG_CALL("tcp_fconnect");
328 DEBUG_ARG("so = %lx", (long )so);
329
330 //fprintf(stderr,"fconnect %d %s\n",ntohs(so->so_fport), inet_ntoa(so->so_faddr));
331 if (__builtin_expect(tcp2unix_check,0) &&
332 (so->so_faddr.s_addr == slirp->vhost_addr.s_addr) &&
333 (path=tcp2unix_search(ntohs(so->so_fport)))!=NULL ) {
334 if ( (ret=so->s=socket(AF_UNIX,SOCK_STREAM,0)) >= 0) {
335 /*int opt;*/
336 int s=so->s;
337 struct sockaddr_un addr;
338
339 fd_nonblock(s);
340 addr.sun_family = AF_UNIX;
341 strncpy(addr.sun_path,path,UNIX_PATH_MAX);
342 ret = connect(s,(struct sockaddr *)&addr,sizeof (addr));
343 soisfconnecting(so);
344 }
345 } else
346 if( (ret = so->s = qemu_socket(AF_INET,SOCK_STREAM,0)) >= 0) {
347 int opt, s=so->s;
348 struct sockaddr_in addr;
349
350 fd_nonblock(s);
351 opt = 1;
352 setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(opt ));
353 opt = 1;
354 setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(opt ));
355
356 addr.sin_family = AF_INET;
357 if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
358 slirp->vnetwork_addr.s_addr) {
359 /* It's an alias */
360 if (so->so_faddr.s_addr == slirp->vnameserver_addr.s_addr) {
361 if (get_dns_addr(&addr.sin_addr) < 0)
362 addr.sin_addr = loopback_addr;
363 } else {
364 addr.sin_addr = loopback_addr;
365 }
366 } else
367 addr.sin_addr = so->so_faddr;
368 addr.sin_port = so->so_fport;
369
370 DEBUG_MISC((dfd, " connect()ing, addr.sin_port=%d, "
371 "addr.sin_addr.s_addr=%.16s\n",
372 ntohs(addr.sin_port), inet_ntoa(addr.sin_addr)));
373 /* We don't care what port we get */
374 ret = connect(s,(struct sockaddr *)&addr,sizeof (addr));
375
376 /*
377 * If it's not in progress, it failed, so we just return 0,
378 * without clearing SS_NOFDREF
379 */
380 soisfconnecting(so);
381 }
382
383 return(ret);
384 }
385
386 /*
387 * Accept the socket and connect to the local-host
388 *
389 * We have a problem. The correct thing to do would be
390 * to first connect to the local-host, and only if the
391 * connection is accepted, then do an accept() here.
392 * But, a) we need to know who's trying to connect
393 * to the socket to be able to SYN the local-host, and
394 * b) we are already connected to the foreign host by
395 * the time it gets to accept(), so... We simply accept
396 * here and SYN the local-host.
397 */
398 void
tcp_connect(struct socket * inso)399 tcp_connect(struct socket *inso)
400 {
401 Slirp *slirp = inso->slirp;
402 struct socket *so;
403 struct sockaddr_in addr;
404 socklen_t addrlen = sizeof(struct sockaddr_in);
405 struct tcpcb *tp;
406 int s, opt;
407
408 DEBUG_CALL("tcp_connect");
409 DEBUG_ARG("inso = %lx", (long)inso);
410
411 /*
412 * If it's an SS_ACCEPTONCE socket, no need to socreate()
413 * another socket, just use the accept() socket.
414 */
415 if (inso->so_state & SS_FACCEPTONCE) {
416 /* FACCEPTONCE already have a tcpcb */
417 so = inso;
418 } else {
419 if ((so = socreate(slirp)) == NULL) {
420 /* If it failed, get rid of the pending connection */
421 closesocket(accept(inso->s,(struct sockaddr *)&addr,&addrlen));
422 return;
423 }
424 if (tcp_attach(so) < 0) {
425 free(so); /* NOT sofree */
426 return;
427 }
428 so->so_laddr = inso->so_laddr;
429 so->so_lport = inso->so_lport;
430 }
431
432 (void) tcp_mss(sototcpcb(so), 0);
433
434 if ((s = accept(inso->s,(struct sockaddr *)&addr,&addrlen)) < 0) {
435 tcp_close(sototcpcb(so)); /* This will sofree() as well */
436 return;
437 }
438 fd_nonblock(s);
439 opt = 1;
440 setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
441 opt = 1;
442 setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
443 opt = 1;
444 setsockopt(s,IPPROTO_TCP,TCP_NODELAY,(char *)&opt,sizeof(int));
445
446 so->so_fport = addr.sin_port;
447 so->so_faddr = addr.sin_addr;
448 /* Translate connections from localhost to the real hostname */
449 if (so->so_faddr.s_addr == 0 || so->so_faddr.s_addr == loopback_addr.s_addr)
450 so->so_faddr = slirp->vhost_addr;
451
452 /* Close the accept() socket, set right state */
453 if (inso->so_state & SS_FACCEPTONCE) {
454 closesocket(so->s); /* If we only accept once, close the accept() socket */
455 so->so_state = SS_NOFDREF; /* Don't select it yet, even though we have an FD */
456 /* if it's not FACCEPTONCE, it's already NOFDREF */
457 }
458 so->s = s;
459 so->so_state |= SS_INCOMING;
460
461 so->so_iptos = tcp_tos(so);
462 tp = sototcpcb(so);
463
464 tcp_template(tp);
465
466 tp->t_state = TCPS_SYN_SENT;
467 tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
468 tp->iss = slirp->tcp_iss;
469 slirp->tcp_iss += TCP_ISSINCR/2;
470 tcp_sendseqinit(tp);
471 tcp_output(tp);
472 }
473
474 /*
475 * Attach a TCPCB to a socket.
476 */
477 int
tcp_attach(struct socket * so)478 tcp_attach(struct socket *so)
479 {
480 if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
481 return -1;
482
483 insque(so, &so->slirp->tcb);
484
485 return 0;
486 }
487
488 /*
489 * Set the socket's type of service field
490 */
491 static const struct tos_t tcptos[] = {
492 {0, 20, IPTOS_THROUGHPUT, 0}, /* ftp data */
493 {21, 21, IPTOS_LOWDELAY, EMU_FTP}, /* ftp control */
494 {0, 23, IPTOS_LOWDELAY, 0}, /* telnet */
495 {0, 80, IPTOS_THROUGHPUT, 0}, /* WWW */
496 {0, 513, IPTOS_LOWDELAY, EMU_RLOGIN|EMU_NOCONNECT}, /* rlogin */
497 {0, 514, IPTOS_LOWDELAY, EMU_RSH|EMU_NOCONNECT}, /* shell */
498 {0, 544, IPTOS_LOWDELAY, EMU_KSH}, /* kshell */
499 {0, 543, IPTOS_LOWDELAY, 0}, /* klogin */
500 {0, 6667, IPTOS_THROUGHPUT, EMU_IRC}, /* IRC */
501 {0, 6668, IPTOS_THROUGHPUT, EMU_IRC}, /* IRC undernet */
502 {0, 7070, IPTOS_LOWDELAY, EMU_REALAUDIO }, /* RealAudio control */
503 {0, 113, IPTOS_LOWDELAY, EMU_IDENT }, /* identd protocol */
504 {0, 0, 0, 0}
505 };
506
507 static struct emu_t *tcpemu = NULL;
508
509 /*
510 * Return TOS according to the above table
511 */
512 u_int8_t
tcp_tos(struct socket * so)513 tcp_tos(struct socket *so)
514 {
515 int i = 0;
516 struct emu_t *emup;
517
518 while(tcptos[i].tos) {
519 if ((tcptos[i].fport && (ntohs(so->so_fport) == tcptos[i].fport)) ||
520 (tcptos[i].lport && (ntohs(so->so_lport) == tcptos[i].lport))) {
521 so->so_emu = tcptos[i].emu;
522 return tcptos[i].tos;
523 }
524 i++;
525 }
526
527 /* Nope, lets see if there's a user-added one */
528 for (emup = tcpemu; emup; emup = emup->next) {
529 if ((emup->fport && (ntohs(so->so_fport) == emup->fport)) ||
530 (emup->lport && (ntohs(so->so_lport) == emup->lport))) {
531 so->so_emu = emup->emu;
532 return emup->tos;
533 }
534 }
535
536 return 0;
537 }
538
539 /*
540 * Emulate programs that try and connect to us
541 * This includes ftp (the data connection is
542 * initiated by the server) and IRC (DCC CHAT and
543 * DCC SEND) for now
544 *
545 * NOTE: It's possible to crash SLiRP by sending it
546 * unstandard strings to emulate... if this is a problem,
547 * more checks are needed here
548 *
549 * XXX Assumes the whole command came in one packet
550 *
551 * XXX Some ftp clients will have their TOS set to
552 * LOWDELAY and so Nagel will kick in. Because of this,
553 * we'll get the first letter, followed by the rest, so
554 * we simply scan for ORT instead of PORT...
555 * DCC doesn't have this problem because there's other stuff
556 * in the packet before the DCC command.
557 *
558 * Return 1 if the mbuf m is still valid and should be
559 * sbappend()ed
560 *
561 * NOTE: if you return 0 you MUST m_free() the mbuf!
562 */
563 int
tcp_emu(struct socket * so,struct mbuf * m)564 tcp_emu(struct socket *so, struct mbuf *m)
565 {
566 Slirp *slirp = so->slirp;
567 u_int n1, n2, n3, n4, n5, n6;
568 char buff[257];
569 u_int32_t laddr;
570 u_int lport;
571 char *bptr;
572
573 DEBUG_CALL("tcp_emu");
574 DEBUG_ARG("so = %lx", (long)so);
575 DEBUG_ARG("m = %lx", (long)m);
576
577 switch(so->so_emu) {
578 int x, i;
579
580 case EMU_IDENT:
581 /*
582 * Identification protocol as per rfc-1413
583 */
584
585 {
586 struct socket *tmpso;
587 struct sockaddr_in addr;
588 socklen_t addrlen = sizeof(struct sockaddr_in);
589 struct sbuf *so_rcv = &so->so_rcv;
590
591 memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
592 so_rcv->sb_wptr += m->m_len;
593 so_rcv->sb_rptr += m->m_len;
594 m->m_data[m->m_len] = 0; /* NULL terminate */
595 if (strchr(m->m_data, '\r') || strchr(m->m_data, '\n')) {
596 if (sscanf(so_rcv->sb_data, "%u%*[ ,]%u", &n1, &n2) == 2) {
597 HTONS(n1);
598 HTONS(n2);
599 /* n2 is the one on our host */
600 for (tmpso = slirp->tcb.so_next;
601 tmpso != &slirp->tcb;
602 tmpso = tmpso->so_next) {
603 if (tmpso->so_laddr.s_addr == so->so_laddr.s_addr &&
604 tmpso->so_lport == n2 &&
605 tmpso->so_faddr.s_addr == so->so_faddr.s_addr &&
606 tmpso->so_fport == n1) {
607 if (getsockname(tmpso->s,
608 (struct sockaddr *)&addr, &addrlen) == 0)
609 n2 = ntohs(addr.sin_port);
610 break;
611 }
612 }
613 }
614 so_rcv->sb_cc = snprintf(so_rcv->sb_data,
615 so_rcv->sb_datalen,
616 "%d,%d\r\n", n1, n2);
617 so_rcv->sb_rptr = so_rcv->sb_data;
618 so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
619 }
620 m_free(m);
621 return 0;
622 }
623
624 case EMU_FTP: /* ftp */
625 *(m->m_data+m->m_len) = 0; /* NUL terminate for strstr */
626 if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
627 /*
628 * Need to emulate the PORT command
629 */
630 x = sscanf(bptr, "ORT %u,%u,%u,%u,%u,%u\r\n%256[^\177]",
631 &n1, &n2, &n3, &n4, &n5, &n6, buff);
632 if (x < 6)
633 return 1;
634
635 laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
636 lport = htons((n5 << 8) | (n6));
637
638 if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
639 lport, SS_FACCEPTONCE)) == NULL) {
640 return 1;
641 }
642 n6 = ntohs(so->so_fport);
643
644 n5 = (n6 >> 8) & 0xff;
645 n6 &= 0xff;
646
647 laddr = ntohl(so->so_faddr.s_addr);
648
649 n1 = ((laddr >> 24) & 0xff);
650 n2 = ((laddr >> 16) & 0xff);
651 n3 = ((laddr >> 8) & 0xff);
652 n4 = (laddr & 0xff);
653
654 m->m_len = bptr - m->m_data; /* Adjust length */
655 m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
656 "ORT %d,%d,%d,%d,%d,%d\r\n%s",
657 n1, n2, n3, n4, n5, n6, x==7?buff:"");
658 return 1;
659 } else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
660 /*
661 * Need to emulate the PASV response
662 */
663 x = sscanf(bptr, "27 Entering Passive Mode (%u,%u,%u,%u,%u,%u)\r\n%256[^\177]",
664 &n1, &n2, &n3, &n4, &n5, &n6, buff);
665 if (x < 6)
666 return 1;
667
668 laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
669 lport = htons((n5 << 8) | (n6));
670
671 if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
672 lport, SS_FACCEPTONCE)) == NULL) {
673 return 1;
674 }
675 n6 = ntohs(so->so_fport);
676
677 n5 = (n6 >> 8) & 0xff;
678 n6 &= 0xff;
679
680 laddr = ntohl(so->so_faddr.s_addr);
681
682 n1 = ((laddr >> 24) & 0xff);
683 n2 = ((laddr >> 16) & 0xff);
684 n3 = ((laddr >> 8) & 0xff);
685 n4 = (laddr & 0xff);
686
687 m->m_len = bptr - m->m_data; /* Adjust length */
688 m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
689 "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
690 n1, n2, n3, n4, n5, n6, x==7?buff:"");
691
692 return 1;
693 }
694
695 return 1;
696
697 case EMU_KSH:
698 /*
699 * The kshell (Kerberos rsh) and shell services both pass
700 * a local port port number to carry signals to the server
701 * and stderr to the client. It is passed at the beginning
702 * of the connection as a NUL-terminated decimal ASCII string.
703 */
704 so->so_emu = 0;
705 for (lport = 0, i = 0; i < m->m_len-1; ++i) {
706 if (m->m_data[i] < '0' || m->m_data[i] > '9')
707 return 1; /* invalid number */
708 lport *= 10;
709 lport += m->m_data[i] - '0';
710 }
711 if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
712 (so = tcp_listen(slirp, INADDR_ANY, 0, so->so_laddr.s_addr,
713 htons(lport), SS_FACCEPTONCE)) != NULL)
714 m->m_len = snprintf(m->m_data, m->m_hdr.mh_size, "%d",
715 ntohs(so->so_fport)) + 1;
716 return 1;
717
718 case EMU_IRC:
719 /*
720 * Need to emulate DCC CHAT, DCC SEND and DCC MOVE
721 */
722 *(m->m_data+m->m_len) = 0; /* NULL terminate the string for strstr */
723 if ((bptr = (char *)strstr(m->m_data, "DCC")) == NULL)
724 return 1;
725
726 /* The %256s is for the broken mIRC */
727 if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) {
728 if ((so = tcp_listen(slirp, INADDR_ANY, 0,
729 htonl(laddr), htons(lport),
730 SS_FACCEPTONCE)) == NULL) {
731 return 1;
732 }
733 m->m_len = bptr - m->m_data; /* Adjust length */
734 m->m_len += snprintf(bptr, m->m_hdr.mh_size,
735 "DCC CHAT chat %lu %u%c\n",
736 (unsigned long)ntohl(so->so_faddr.s_addr),
737 ntohs(so->so_fport), 1);
738 } else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
739 if ((so = tcp_listen(slirp, INADDR_ANY, 0,
740 htonl(laddr), htons(lport),
741 SS_FACCEPTONCE)) == NULL) {
742 return 1;
743 }
744 m->m_len = bptr - m->m_data; /* Adjust length */
745 m->m_len += snprintf(bptr, m->m_hdr.mh_size,
746 "DCC SEND %s %lu %u %u%c\n", buff,
747 (unsigned long)ntohl(so->so_faddr.s_addr),
748 ntohs(so->so_fport), n1, 1);
749 } else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
750 if ((so = tcp_listen(slirp, INADDR_ANY, 0,
751 htonl(laddr), htons(lport),
752 SS_FACCEPTONCE)) == NULL) {
753 return 1;
754 }
755 m->m_len = bptr - m->m_data; /* Adjust length */
756 m->m_len += snprintf(bptr, m->m_hdr.mh_size,
757 "DCC MOVE %s %lu %u %u%c\n", buff,
758 (unsigned long)ntohl(so->so_faddr.s_addr),
759 ntohs(so->so_fport), n1, 1);
760 }
761 return 1;
762
763 case EMU_REALAUDIO:
764 /*
765 * RealAudio emulation - JP. We must try to parse the incoming
766 * data and try to find the two characters that contain the
767 * port number. Then we redirect an udp port and replace the
768 * number with the real port we got.
769 *
770 * The 1.0 beta versions of the player are not supported
771 * any more.
772 *
773 * A typical packet for player version 1.0 (release version):
774 *
775 * 0000:50 4E 41 00 05
776 * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 ........g.l.c..P
777 * 0010:4E 43 4C 49 45 4E 54 20 31 30 31 20 41 4C 50 48 NCLIENT 101 ALPH
778 * 0020:41 6C 00 00 52 00 17 72 61 66 69 6C 65 73 2F 76 Al..R..rafiles/v
779 * 0030:6F 61 2F 65 6E 67 6C 69 73 68 5F 2E 72 61 79 42 oa/english_.rayB
780 *
781 * Now the port number 0x1BD7 is found at offset 0x04 of the
782 * Now the port number 0x1BD7 is found at offset 0x04 of the
783 * second packet. This time we received five bytes first and
784 * then the rest. You never know how many bytes you get.
785 *
786 * A typical packet for player version 2.0 (beta):
787 *
788 * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA.............
789 * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .gux.c..Win2.0.0
790 * 0020:2E 35 6C 00 00 52 00 1C 72 61 66 69 6C 65 73 2F .5l..R..rafiles/
791 * 0030:77 65 62 73 69 74 65 2F 32 30 72 65 6C 65 61 73 website/20releas
792 * 0040:65 2E 72 61 79 53 00 00 06 36 42 e.rayS...6B
793 *
794 * Port number 0x1BC1 is found at offset 0x0d.
795 *
796 * This is just a horrible switch statement. Variable ra tells
797 * us where we're going.
798 */
799
800 bptr = m->m_data;
801 while (bptr < m->m_data + m->m_len) {
802 u_short p;
803 static int ra = 0;
804 char ra_tbl[4];
805
806 ra_tbl[0] = 0x50;
807 ra_tbl[1] = 0x4e;
808 ra_tbl[2] = 0x41;
809 ra_tbl[3] = 0;
810
811 switch (ra) {
812 case 0:
813 case 2:
814 case 3:
815 if (*bptr++ != ra_tbl[ra]) {
816 ra = 0;
817 continue;
818 }
819 break;
820
821 case 1:
822 /*
823 * We may get 0x50 several times, ignore them
824 */
825 if (*bptr == 0x50) {
826 ra = 1;
827 bptr++;
828 continue;
829 } else if (*bptr++ != ra_tbl[ra]) {
830 ra = 0;
831 continue;
832 }
833 break;
834
835 case 4:
836 /*
837 * skip version number
838 */
839 bptr++;
840 break;
841
842 case 5:
843 /*
844 * The difference between versions 1.0 and
845 * 2.0 is here. For future versions of
846 * the player this may need to be modified.
847 */
848 if (*(bptr + 1) == 0x02)
849 bptr += 8;
850 else
851 bptr += 4;
852 break;
853
854 case 6:
855 /* This is the field containing the port
856 * number that RA-player is listening to.
857 */
858 lport = (((u_char*)bptr)[0] << 8)
859 + ((u_char *)bptr)[1];
860 if (lport < 6970)
861 lport += 256; /* don't know why */
862 if (lport < 6970 || lport > 7170)
863 return 1; /* failed */
864
865 /* try to get udp port between 6970 - 7170 */
866 for (p = 6970; p < 7071; p++) {
867 if (udp_listen(slirp, INADDR_ANY,
868 htons(p),
869 so->so_laddr.s_addr,
870 htons(lport),
871 SS_FACCEPTONCE)) {
872 break;
873 }
874 }
875 if (p == 7071)
876 p = 0;
877 *(u_char *)bptr++ = (p >> 8) & 0xff;
878 *(u_char *)bptr++ = p & 0xff;
879 ra = 0;
880 return 1; /* port redirected, we're done */
881 break;
882
883 default:
884 ra = 0;
885 }
886 ra++;
887 }
888 return 1;
889
890 default:
891 /* Ooops, not emulated, won't call tcp_emu again */
892 so->so_emu = 0;
893 return 1;
894 }
895 }
896
897 /*
898 * Do misc. config of SLiRP while its running.
899 * Return 0 if this connections is to be closed, 1 otherwise,
900 * return 2 if this is a command-line connection
901 */
tcp_ctl(struct socket * so)902 int tcp_ctl(struct socket *so)
903 {
904 #if 0
905 Slirp *slirp = so->slirp;
906 struct sbuf *sb = &so->so_snd;
907 struct ex_list *ex_ptr;
908 int do_pty;
909
910 DEBUG_CALL("tcp_ctl");
911 DEBUG_ARG("so = %lx", (long )so);
912
913 if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr) {
914 /* Check if it's pty_exec */
915 for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
916 if (ex_ptr->ex_fport == so->so_fport &&
917 so->so_faddr.s_addr == ex_ptr->ex_addr.s_addr) {
918 if (ex_ptr->ex_pty == 3) {
919 so->s = -1;
920 so->extra = (void *)ex_ptr->ex_exec;
921 return 1;
922 }
923 do_pty = ex_ptr->ex_pty;
924 DEBUG_MISC((dfd, " executing %s \n",ex_ptr->ex_exec));
925 return fork_exec(so, ex_ptr->ex_exec, do_pty);
926 }
927 }
928 }
929 sb->sb_cc =
930 snprintf(sb->sb_wptr, sb->sb_datalen - (sb->sb_wptr - sb->sb_data),
931 "Error: No application configured.\r\n");
932 sb->sb_wptr += sb->sb_cc;
933 #endif
934 return 0;
935 }
936