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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
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
9
 *    notice, this list of conditions and the following disclaimer.
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 * 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
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
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 * 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
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 * 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
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 * SUCH DAMAGE.
28
 *
29
 *        @(#)tcp_subr.c        8.1 (Berkeley) 6/10/93
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 * 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(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
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()) == 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 *
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
 */
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 *
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
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
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
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
 */
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 & vnetwork_mask.s_addr) == vnetwork_addr.s_addr) {
388
      /* It's an alias */
389
      if (so->so_faddr.s_addr == vnameserver_addr.s_addr) {
390
        addr.sin_addr = dns_addr;
391
      } else {
392
        addr.sin_addr = loopback_addr;
393
      }
394
    } else
395
      addr.sin_addr = so->so_faddr;
396
    addr.sin_port = so->so_fport;
397

    
398
    DEBUG_MISC((dfd, " connect()ing, addr.sin_port=%d, "
399
                "addr.sin_addr.s_addr=%.16s\n",
400
                ntohs(addr.sin_port), inet_ntoa(addr.sin_addr)));
401
    /* We don't care what port we get */
402
    ret = connect(s,(struct sockaddr *)&addr,sizeof (addr));
403

    
404
    /*
405
     * If it's not in progress, it failed, so we just return 0,
406
     * without clearing SS_NOFDREF
407
     */
408
    soisfconnecting(so);
409
  }
410

    
411
  return(ret);
412
}
413

    
414
/*
415
 * Accept the socket and connect to the local-host
416
 *
417
 * We have a problem. The correct thing to do would be
418
 * to first connect to the local-host, and only if the
419
 * connection is accepted, then do an accept() here.
420
 * But, a) we need to know who's trying to connect
421
 * to the socket to be able to SYN the local-host, and
422
 * b) we are already connected to the foreign host by
423
 * the time it gets to accept(), so... We simply accept
424
 * here and SYN the local-host.
425
 */
426
void
427
tcp_connect(struct socket *inso)
428
{
429
        struct socket *so;
430
        struct sockaddr_in addr;
431
        socklen_t addrlen = sizeof(struct sockaddr_in);
432
        struct tcpcb *tp;
433
        int s, opt;
434

    
435
        DEBUG_CALL("tcp_connect");
436
        DEBUG_ARG("inso = %lx", (long)inso);
437

    
438
        /*
439
         * If it's an SS_ACCEPTONCE socket, no need to socreate()
440
         * another socket, just use the accept() socket.
441
         */
442
        if (inso->so_state & SS_FACCEPTONCE) {
443
                /* FACCEPTONCE already have a tcpcb */
444
                so = inso;
445
        } else {
446
                if ((so = socreate()) == NULL) {
447
                        /* If it failed, get rid of the pending connection */
448
                        closesocket(accept(inso->s,(struct sockaddr *)&addr,&addrlen));
449
                        return;
450
                }
451
                if (tcp_attach(so) < 0) {
452
                        free(so); /* NOT sofree */
453
                        return;
454
                }
455
                so->so_laddr = inso->so_laddr;
456
                so->so_lport = inso->so_lport;
457
        }
458

    
459
        (void) tcp_mss(sototcpcb(so), 0);
460

    
461
        if ((s = accept(inso->s,(struct sockaddr *)&addr,&addrlen)) < 0) {
462
                tcp_close(sototcpcb(so)); /* This will sofree() as well */
463
                return;
464
        }
465
        fd_nonblock(s);
466
        opt = 1;
467
        setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
468
        opt = 1;
469
        setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
470
        opt = 1;
471
        setsockopt(s,IPPROTO_TCP,TCP_NODELAY,(char *)&opt,sizeof(int));
472

    
473
        so->so_fport = addr.sin_port;
474
        so->so_faddr = addr.sin_addr;
475
        /* Translate connections from localhost to the real hostname */
476
        if (so->so_faddr.s_addr == 0 || so->so_faddr.s_addr == loopback_addr.s_addr)
477
           so->so_faddr = vhost_addr;
478

    
479
        /* Close the accept() socket, set right state */
480
        if (inso->so_state & SS_FACCEPTONCE) {
481
                closesocket(so->s); /* If we only accept once, close the accept() socket */
482
                so->so_state = SS_NOFDREF; /* Don't select it yet, even though we have an FD */
483
                                           /* if it's not FACCEPTONCE, it's already NOFDREF */
484
        }
485
        so->s = s;
486
        so->so_state |= SS_INCOMING;
487

    
488
        so->so_iptos = tcp_tos(so);
489
        tp = sototcpcb(so);
490

    
491
        tcp_template(tp);
492

    
493
        /* Compute window scaling to request.  */
494
/*        while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
495
 *                (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
496
 *                tp->request_r_scale++;
497
 */
498

    
499
/*        soisconnecting(so); */ /* NOFDREF used instead */
500
        STAT(tcpstat.tcps_connattempt++);
501

    
502
        tp->t_state = TCPS_SYN_SENT;
503
        tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
504
        tp->iss = tcp_iss;
505
        tcp_iss += TCP_ISSINCR/2;
506
        tcp_sendseqinit(tp);
507
        tcp_output(tp);
508
}
509

    
510
/*
511
 * Attach a TCPCB to a socket.
512
 */
513
int
514
tcp_attach(struct socket *so)
515
{
516
        if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
517
           return -1;
518

    
519
        insque(so, &tcb);
520

    
521
        return 0;
522
}
523

    
524
/*
525
 * Set the socket's type of service field
526
 */
527
static const struct tos_t tcptos[] = {
528
          {0, 20, IPTOS_THROUGHPUT, 0},        /* ftp data */
529
          {21, 21, IPTOS_LOWDELAY,  EMU_FTP},        /* ftp control */
530
          {0, 23, IPTOS_LOWDELAY, 0},        /* telnet */
531
          {0, 80, IPTOS_THROUGHPUT, 0},        /* WWW */
532
          {0, 513, IPTOS_LOWDELAY, EMU_RLOGIN|EMU_NOCONNECT},        /* rlogin */
533
          {0, 514, IPTOS_LOWDELAY, EMU_RSH|EMU_NOCONNECT},        /* shell */
534
          {0, 544, IPTOS_LOWDELAY, EMU_KSH},                /* kshell */
535
          {0, 543, IPTOS_LOWDELAY, 0},        /* klogin */
536
          {0, 6667, IPTOS_THROUGHPUT, EMU_IRC},        /* IRC */
537
          {0, 6668, IPTOS_THROUGHPUT, EMU_IRC},        /* IRC undernet */
538
          {0, 7070, IPTOS_LOWDELAY, EMU_REALAUDIO }, /* RealAudio control */
539
          {0, 113, IPTOS_LOWDELAY, EMU_IDENT }, /* identd protocol */
540
          {0, 0, 0, 0}
541
};
542

    
543
#ifdef CONFIG_QEMU
544
static
545
#endif
546
struct emu_t *tcpemu = NULL;
547

    
548
/*
549
 * Return TOS according to the above table
550
 */
551
u_int8_t
552
tcp_tos(struct socket *so)
553
{
554
        int i = 0;
555
        struct emu_t *emup;
556

    
557
        while(tcptos[i].tos) {
558
                if ((tcptos[i].fport && (ntohs(so->so_fport) == tcptos[i].fport)) ||
559
                    (tcptos[i].lport && (ntohs(so->so_lport) == tcptos[i].lport))) {
560
                        so->so_emu = tcptos[i].emu;
561
                        return tcptos[i].tos;
562
                }
563
                i++;
564
        }
565

    
566
        /* Nope, lets see if there's a user-added one */
567
        for (emup = tcpemu; emup; emup = emup->next) {
568
                if ((emup->fport && (ntohs(so->so_fport) == emup->fport)) ||
569
                    (emup->lport && (ntohs(so->so_lport) == emup->lport))) {
570
                        so->so_emu = emup->emu;
571
                        return emup->tos;
572
                }
573
        }
574

    
575
        return 0;
576
}
577

    
578
#if 0
579
int do_echo = -1;
580
#endif
581

    
582
/*
583
 * Emulate programs that try and connect to us
584
 * This includes ftp (the data connection is
585
 * initiated by the server) and IRC (DCC CHAT and
586
 * DCC SEND) for now
587
 *
588
 * NOTE: It's possible to crash SLiRP by sending it
589
 * unstandard strings to emulate... if this is a problem,
590
 * more checks are needed here
591
 *
592
 * XXX Assumes the whole command came in one packet
593
 *
594
 * XXX Some ftp clients will have their TOS set to
595
 * LOWDELAY and so Nagel will kick in.  Because of this,
596
 * we'll get the first letter, followed by the rest, so
597
 * we simply scan for ORT instead of PORT...
598
 * DCC doesn't have this problem because there's other stuff
599
 * in the packet before the DCC command.
600
 *
601
 * Return 1 if the mbuf m is still valid and should be
602
 * sbappend()ed
603
 *
604
 * NOTE: if you return 0 you MUST m_free() the mbuf!
605
 */
606
int
607
tcp_emu(struct socket *so, struct mbuf *m)
608
{
609
        u_int n1, n2, n3, n4, n5, n6;
610
        char buff[257];
611
        u_int32_t laddr;
612
        u_int lport;
613
        char *bptr;
614

    
615
        DEBUG_CALL("tcp_emu");
616
        DEBUG_ARG("so = %lx", (long)so);
617
        DEBUG_ARG("m = %lx", (long)m);
618

    
619
        switch(so->so_emu) {
620
                int x, i;
621

    
622
         case EMU_IDENT:
623
                /*
624
                 * Identification protocol as per rfc-1413
625
                 */
626

    
627
                {
628
                        struct socket *tmpso;
629
                        struct sockaddr_in addr;
630
                        socklen_t addrlen = sizeof(struct sockaddr_in);
631
                        struct sbuf *so_rcv = &so->so_rcv;
632

    
633
                        memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
634
                        so_rcv->sb_wptr += m->m_len;
635
                        so_rcv->sb_rptr += m->m_len;
636
                        m->m_data[m->m_len] = 0; /* NULL terminate */
637
                        if (strchr(m->m_data, '\r') || strchr(m->m_data, '\n')) {
638
                                if (sscanf(so_rcv->sb_data, "%u%*[ ,]%u", &n1, &n2) == 2) {
639
                                        HTONS(n1);
640
                                        HTONS(n2);
641
                                        /* n2 is the one on our host */
642
                                        for (tmpso = tcb.so_next; tmpso != &tcb; tmpso = tmpso->so_next) {
643
                                                if (tmpso->so_laddr.s_addr == so->so_laddr.s_addr &&
644
                                                    tmpso->so_lport == n2 &&
645
                                                    tmpso->so_faddr.s_addr == so->so_faddr.s_addr &&
646
                                                    tmpso->so_fport == n1) {
647
                                                        if (getsockname(tmpso->s,
648
                                                                (struct sockaddr *)&addr, &addrlen) == 0)
649
                                                           n2 = ntohs(addr.sin_port);
650
                                                        break;
651
                                                }
652
                                        }
653
                                }
654
                                so_rcv->sb_cc = snprintf(so_rcv->sb_data,
655
                                                         so_rcv->sb_datalen,
656
                                                         "%d,%d\r\n", n1, n2);
657
                                so_rcv->sb_rptr = so_rcv->sb_data;
658
                                so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
659
                        }
660
                        m_free(m);
661
                        return 0;
662
                }
663

    
664
#if 0
665
         case EMU_RLOGIN:
666
                /*
667
                 * Rlogin emulation
668
                 * First we accumulate all the initial option negotiation,
669
                 * then fork_exec() rlogin according to the  options
670
                 */
671
                {
672
                        int i, i2, n;
673
                        char *ptr;
674
                        char args[100];
675
                        char term[100];
676
                        struct sbuf *so_snd = &so->so_snd;
677
                        struct sbuf *so_rcv = &so->so_rcv;
678

679
                        /* First check if they have a priveladged port, or too much data has arrived */
680
                        if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
681
                            (m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
682
                                memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
683
                                so_snd->sb_wptr += 18;
684
                                so_snd->sb_cc += 18;
685
                                tcp_sockclosed(sototcpcb(so));
686
                                m_free(m);
687
                                return 0;
688
                        }
689

690
                        /* Append the current data */
691
                        memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
692
                        so_rcv->sb_wptr += m->m_len;
693
                        so_rcv->sb_rptr += m->m_len;
694
                        m_free(m);
695

696
                        /*
697
                         * Check if we have all the initial options,
698
                         * and build argument list to rlogin while we're here
699
                         */
700
                        n = 0;
701
                        ptr = so_rcv->sb_data;
702
                        args[0] = 0;
703
                        term[0] = 0;
704
                        while (ptr < so_rcv->sb_wptr) {
705
                                if (*ptr++ == 0) {
706
                                        n++;
707
                                        if (n == 2) {
708
                                                sprintf(args, "rlogin -l %s %s",
709
                                                        ptr, inet_ntoa(so->so_faddr));
710
                                        } else if (n == 3) {
711
                                                i2 = so_rcv->sb_wptr - ptr;
712
                                                for (i = 0; i < i2; i++) {
713
                                                        if (ptr[i] == '/') {
714
                                                                ptr[i] = 0;
715
#ifdef HAVE_SETENV
716
                                                                sprintf(term, "%s", ptr);
717
#else
718
                                                                sprintf(term, "TERM=%s", ptr);
719
#endif
720
                                                                ptr[i] = '/';
721
                                                                break;
722
                                                        }
723
                                                }
724
                                        }
725
                                }
726
                        }
727

    
728
                        if (n != 4)
729
                           return 0;
730

    
731
                        /* We have it, set our term variable and fork_exec() */
732
#ifdef HAVE_SETENV
733
                        setenv("TERM", term, 1);
734
#else
735
                        putenv(term);
736
#endif
737
                        fork_exec(so, args, 2);
738
                        term[0] = 0;
739
                        so->so_emu = 0;
740

    
741
                        /* And finally, send the client a 0 character */
742
                        so_snd->sb_wptr[0] = 0;
743
                        so_snd->sb_wptr++;
744
                        so_snd->sb_cc++;
745

    
746
                        return 0;
747
                }
748

    
749
         case EMU_RSH:
750
                /*
751
                 * rsh emulation
752
                 * First we accumulate all the initial option negotiation,
753
                 * then rsh_exec() rsh according to the  options
754
                 */
755
                {
756
                        int  n;
757
                        char *ptr;
758
                        char *user;
759
                        char *args;
760
                        struct sbuf *so_snd = &so->so_snd;
761
                        struct sbuf *so_rcv = &so->so_rcv;
762

    
763
                        /* First check if they have a priveladged port, or too much data has arrived */
764
                        if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
765
                            (m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
766
                                memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
767
                                so_snd->sb_wptr += 18;
768
                                so_snd->sb_cc += 18;
769
                                tcp_sockclosed(sototcpcb(so));
770
                                m_free(m);
771
                                return 0;
772
                        }
773

    
774
                        /* Append the current data */
775
                        memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
776
                        so_rcv->sb_wptr += m->m_len;
777
                        so_rcv->sb_rptr += m->m_len;
778
                        m_free(m);
779

    
780
                        /*
781
                         * Check if we have all the initial options,
782
                         * and build argument list to rlogin while we're here
783
                         */
784
                        n = 0;
785
                        ptr = so_rcv->sb_data;
786
                        user="";
787
                        args="";
788
                        if (so->extra==NULL) {
789
                                struct socket *ns;
790
                                struct tcpcb* tp;
791
                                int port=atoi(ptr);
792
                                if (port <= 0) return 0;
793
                if (port > 1023 || port < 512) {
794
                  memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
795
                  so_snd->sb_wptr += 18;
796
                  so_snd->sb_cc += 18;
797
                  tcp_sockclosed(sototcpcb(so));
798
                  return 0;
799
                }
800
                                if ((ns=socreate()) == NULL)
801
                  return 0;
802
                                if (tcp_attach(ns)<0) {
803
                  free(ns);
804
                  return 0;
805
                                }
806

    
807
                                ns->so_laddr=so->so_laddr;
808
                                ns->so_lport=htons(port);
809

    
810
                                (void) tcp_mss(sototcpcb(ns), 0);
811

    
812
                                ns->so_faddr=so->so_faddr;
813
                                ns->so_fport=htons(IPPORT_RESERVED-1); /* Use a fake port. */
814

    
815
                                if (ns->so_faddr.s_addr == 0 ||
816
                                        ns->so_faddr.s_addr == loopback_addr.s_addr)
817
                  ns->so_faddr = alias_addr;
818

    
819
                                ns->so_iptos = tcp_tos(ns);
820
                                tp = sototcpcb(ns);
821

    
822
                                tcp_template(tp);
823

    
824
                                /* Compute window scaling to request.  */
825
                                /*        while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
826
                                 *                (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
827
                                 *                tp->request_r_scale++;
828
                                 */
829

    
830
                /*soisfconnecting(ns);*/
831

    
832
                                STAT(tcpstat.tcps_connattempt++);
833

    
834
                                tp->t_state = TCPS_SYN_SENT;
835
                                tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
836
                                tp->iss = tcp_iss;
837
                                tcp_iss += TCP_ISSINCR/2;
838
                                tcp_sendseqinit(tp);
839
                                tcp_output(tp);
840
                                so->extra=ns;
841
                        }
842
                        while (ptr < so_rcv->sb_wptr) {
843
              if (*ptr++ == 0) {
844
                n++;
845
                if (n == 2) {
846
                  user=ptr;
847
                } else if (n == 3) {
848
                  args=ptr;
849
                }
850
              }
851
                        }
852

    
853
                        if (n != 4)
854
              return 0;
855

    
856
                        rsh_exec(so,so->extra, user, inet_ntoa(so->so_faddr), args);
857
                        so->so_emu = 0;
858
                        so->extra=NULL;
859

    
860
                        /* And finally, send the client a 0 character */
861
                        so_snd->sb_wptr[0] = 0;
862
                        so_snd->sb_wptr++;
863
                        so_snd->sb_cc++;
864

    
865
                        return 0;
866
                }
867

    
868
         case EMU_CTL:
869
                {
870
                        int num;
871
                        struct sbuf *so_snd = &so->so_snd;
872
                        struct sbuf *so_rcv = &so->so_rcv;
873

    
874
                        /*
875
                         * If there is binary data here, we save it in so->so_m
876
                         */
877
                        if (!so->so_m) {
878
                          int rxlen;
879
                          char *rxdata;
880
                          rxdata=mtod(m, char *);
881
                          for (rxlen=m->m_len; rxlen; rxlen--) {
882
                            if (*rxdata++ & 0x80) {
883
                              so->so_m = m;
884
                              return 0;
885
                            }
886
                          }
887
                        } /* if(so->so_m==NULL) */
888

    
889
                        /*
890
                         * Append the line
891
                         */
892
                        sbappendsb(so_rcv, m);
893

    
894
                        /* To avoid going over the edge of the buffer, we reset it */
895
                        if (so_snd->sb_cc == 0)
896
                           so_snd->sb_wptr = so_snd->sb_rptr = so_snd->sb_data;
897

    
898
                        /*
899
                         * A bit of a hack:
900
                         * If the first packet we get here is 1 byte long, then it
901
                         * was done in telnet character mode, therefore we must echo
902
                         * the characters as they come.  Otherwise, we echo nothing,
903
                         * because in linemode, the line is already echoed
904
                         * XXX two or more control connections won't work
905
                         */
906
                        if (do_echo == -1) {
907
                                if (m->m_len == 1) do_echo = 1;
908
                                else do_echo = 0;
909
                        }
910
                        if (do_echo) {
911
                          sbappendsb(so_snd, m);
912
                          m_free(m);
913
                          tcp_output(sototcpcb(so)); /* XXX */
914
                        } else
915
                          m_free(m);
916

    
917
                        num = 0;
918
                        while (num < so->so_rcv.sb_cc) {
919
                                if (*(so->so_rcv.sb_rptr + num) == '\n' ||
920
                                    *(so->so_rcv.sb_rptr + num) == '\r') {
921
                                        int n;
922

    
923
                                        *(so_rcv->sb_rptr + num) = 0;
924
                                        if (ctl_password && !ctl_password_ok) {
925
                                                /* Need a password */
926
                                                if (sscanf(so_rcv->sb_rptr, "pass %256s", buff) == 1) {
927
                                                        if (strcmp(buff, ctl_password) == 0) {
928
                                                                ctl_password_ok = 1;
929
                                                                n = sprintf(so_snd->sb_wptr,
930
                                                                            "Password OK.\r\n");
931
                                                                goto do_prompt;
932
                                                        }
933
                                                }
934
                                                n = sprintf(so_snd->sb_wptr,
935
                                         "Error: Password required, log on with \"pass PASSWORD\"\r\n");
936
                                                goto do_prompt;
937
                                        }
938
                                        cfg_quitting = 0;
939
                                        n = do_config(so_rcv->sb_rptr, so, PRN_SPRINTF);
940
                                        if (!cfg_quitting) {
941
                                                /* Register the printed data */
942
do_prompt:
943
                                                so_snd->sb_cc += n;
944
                                                so_snd->sb_wptr += n;
945
                                                /* Add prompt */
946
                                                n = sprintf(so_snd->sb_wptr, "Slirp> ");
947
                                                so_snd->sb_cc += n;
948
                                                so_snd->sb_wptr += n;
949
                                        }
950
                                        /* Drop so_rcv data */
951
                                        so_rcv->sb_cc = 0;
952
                                        so_rcv->sb_wptr = so_rcv->sb_rptr = so_rcv->sb_data;
953
                                        tcp_output(sototcpcb(so)); /* Send the reply */
954
                                }
955
                                num++;
956
                        }
957
                        return 0;
958
                }
959
#endif
960
        case EMU_FTP: /* ftp */
961
                *(m->m_data+m->m_len) = 0; /* NUL terminate for strstr */
962
                if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
963
                        /*
964
                         * Need to emulate the PORT command
965
                         */
966
                        x = sscanf(bptr, "ORT %u,%u,%u,%u,%u,%u\r\n%256[^\177]",
967
                                   &n1, &n2, &n3, &n4, &n5, &n6, buff);
968
                        if (x < 6)
969
                           return 1;
970

    
971
                        laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
972
                        lport = htons((n5 << 8) | (n6));
973

    
974
                        if ((so = tcp_listen(INADDR_ANY, 0, laddr, lport, SS_FACCEPTONCE)) == NULL)
975
                           return 1;
976

    
977
                        n6 = ntohs(so->so_fport);
978

    
979
                        n5 = (n6 >> 8) & 0xff;
980
                        n6 &= 0xff;
981

    
982
                        laddr = ntohl(so->so_faddr.s_addr);
983

    
984
                        n1 = ((laddr >> 24) & 0xff);
985
                        n2 = ((laddr >> 16) & 0xff);
986
                        n3 = ((laddr >> 8)  & 0xff);
987
                        n4 =  (laddr & 0xff);
988

    
989
                        m->m_len = bptr - m->m_data; /* Adjust length */
990
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
991
                                             "ORT %d,%d,%d,%d,%d,%d\r\n%s",
992
                                             n1, n2, n3, n4, n5, n6, x==7?buff:"");
993
                        return 1;
994
                } else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
995
                        /*
996
                         * Need to emulate the PASV response
997
                         */
998
                        x = sscanf(bptr, "27 Entering Passive Mode (%u,%u,%u,%u,%u,%u)\r\n%256[^\177]",
999
                                   &n1, &n2, &n3, &n4, &n5, &n6, buff);
1000
                        if (x < 6)
1001
                           return 1;
1002

    
1003
                        laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
1004
                        lport = htons((n5 << 8) | (n6));
1005

    
1006
                        if ((so = tcp_listen(INADDR_ANY, 0, laddr, lport, SS_FACCEPTONCE)) == NULL)
1007
                           return 1;
1008

    
1009
                        n6 = ntohs(so->so_fport);
1010

    
1011
                        n5 = (n6 >> 8) & 0xff;
1012
                        n6 &= 0xff;
1013

    
1014
                        laddr = ntohl(so->so_faddr.s_addr);
1015

    
1016
                        n1 = ((laddr >> 24) & 0xff);
1017
                        n2 = ((laddr >> 16) & 0xff);
1018
                        n3 = ((laddr >> 8)  & 0xff);
1019
                        n4 =  (laddr & 0xff);
1020

    
1021
                        m->m_len = bptr - m->m_data; /* Adjust length */
1022
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
1023
                                             "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
1024
                                             n1, n2, n3, n4, n5, n6, x==7?buff:"");
1025

    
1026
                        return 1;
1027
                }
1028

    
1029
                return 1;
1030

    
1031
         case EMU_KSH:
1032
                /*
1033
                 * The kshell (Kerberos rsh) and shell services both pass
1034
                 * a local port port number to carry signals to the server
1035
                 * and stderr to the client.  It is passed at the beginning
1036
                 * of the connection as a NUL-terminated decimal ASCII string.
1037
                 */
1038
                so->so_emu = 0;
1039
                for (lport = 0, i = 0; i < m->m_len-1; ++i) {
1040
                        if (m->m_data[i] < '0' || m->m_data[i] > '9')
1041
                                return 1;       /* invalid number */
1042
                        lport *= 10;
1043
                        lport += m->m_data[i] - '0';
1044
                }
1045
                if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
1046
                    (so = tcp_listen(INADDR_ANY, 0, so->so_laddr.s_addr, htons(lport), SS_FACCEPTONCE)) != NULL)
1047
                    m->m_len = snprintf(m->m_data, m->m_hdr.mh_size, "%d",
1048
                                        ntohs(so->so_fport)) + 1;
1049
                return 1;
1050

    
1051
         case EMU_IRC:
1052
                /*
1053
                 * Need to emulate DCC CHAT, DCC SEND and DCC MOVE
1054
                 */
1055
                *(m->m_data+m->m_len) = 0; /* NULL terminate the string for strstr */
1056
                if ((bptr = (char *)strstr(m->m_data, "DCC")) == NULL)
1057
                         return 1;
1058

    
1059
                /* The %256s is for the broken mIRC */
1060
                if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) {
1061
                        if ((so = tcp_listen(INADDR_ANY, 0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1062
                                return 1;
1063

    
1064
                        m->m_len = bptr - m->m_data; /* Adjust length */
1065
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
1066
                                             "DCC CHAT chat %lu %u%c\n",
1067
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
1068
                                             ntohs(so->so_fport), 1);
1069
                } else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
1070
                        if ((so = tcp_listen(INADDR_ANY, 0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1071
                                return 1;
1072

    
1073
                        m->m_len = bptr - m->m_data; /* Adjust length */
1074
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
1075
                                             "DCC SEND %s %lu %u %u%c\n", buff,
1076
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
1077
                                             ntohs(so->so_fport), n1, 1);
1078
                } else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
1079
                        if ((so = tcp_listen(INADDR_ANY, 0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1080
                                return 1;
1081

    
1082
                        m->m_len = bptr - m->m_data; /* Adjust length */
1083
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
1084
                                             "DCC MOVE %s %lu %u %u%c\n", buff,
1085
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
1086
                                             ntohs(so->so_fport), n1, 1);
1087
                }
1088
                return 1;
1089

    
1090
         case EMU_REALAUDIO:
1091
                /*
1092
                 * RealAudio emulation - JP. We must try to parse the incoming
1093
                 * data and try to find the two characters that contain the
1094
                 * port number. Then we redirect an udp port and replace the
1095
                 * number with the real port we got.
1096
                 *
1097
                 * The 1.0 beta versions of the player are not supported
1098
                 * any more.
1099
                 *
1100
                 * A typical packet for player version 1.0 (release version):
1101
                 *
1102
                 * 0000:50 4E 41 00 05
1103
                 * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 .....?..g?l?c..P
1104
                 * 0010:4E 43 4C 49 45 4E 54 20 31 30 31 20 41 4C 50 48 NCLIENT 101 ALPH
1105
                 * 0020:41 6C 00 00 52 00 17 72 61 66 69 6C 65 73 2F 76 Al..R..rafiles/v
1106
                 * 0030:6F 61 2F 65 6E 67 6C 69 73 68 5F 2E 72 61 79 42 oa/english_.rayB
1107
                 *
1108
                 * Now the port number 0x1BD7 is found at offset 0x04 of the
1109
                 * Now the port number 0x1BD7 is found at offset 0x04 of the
1110
                 * second packet. This time we received five bytes first and
1111
                 * then the rest. You never know how many bytes you get.
1112
                 *
1113
                 * A typical packet for player version 2.0 (beta):
1114
                 *
1115
                 * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA...........?.
1116
                 * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .gux?c..Win2.0.0
1117
                 * 0020:2E 35 6C 00 00 52 00 1C 72 61 66 69 6C 65 73 2F .5l..R..rafiles/
1118
                 * 0030:77 65 62 73 69 74 65 2F 32 30 72 65 6C 65 61 73 website/20releas
1119
                 * 0040:65 2E 72 61 79 53 00 00 06 36 42                e.rayS...6B
1120
                 *
1121
                 * Port number 0x1BC1 is found at offset 0x0d.
1122
                 *
1123
                 * This is just a horrible switch statement. Variable ra tells
1124
                 * us where we're going.
1125
                 */
1126

    
1127
                bptr = m->m_data;
1128
                while (bptr < m->m_data + m->m_len) {
1129
                        u_short p;
1130
                        static int ra = 0;
1131
                        char ra_tbl[4];
1132

    
1133
                        ra_tbl[0] = 0x50;
1134
                        ra_tbl[1] = 0x4e;
1135
                        ra_tbl[2] = 0x41;
1136
                        ra_tbl[3] = 0;
1137

    
1138
                        switch (ra) {
1139
                         case 0:
1140
                         case 2:
1141
                         case 3:
1142
                                if (*bptr++ != ra_tbl[ra]) {
1143
                                        ra = 0;
1144
                                        continue;
1145
                                }
1146
                                break;
1147

    
1148
                         case 1:
1149
                                /*
1150
                                 * We may get 0x50 several times, ignore them
1151
                                 */
1152
                                if (*bptr == 0x50) {
1153
                                        ra = 1;
1154
                                        bptr++;
1155
                                        continue;
1156
                                } else if (*bptr++ != ra_tbl[ra]) {
1157
                                        ra = 0;
1158
                                        continue;
1159
                                }
1160
                                break;
1161

    
1162
                         case 4:
1163
                                /*
1164
                                 * skip version number
1165
                                 */
1166
                                bptr++;
1167
                                break;
1168

    
1169
                         case 5:
1170
                                /*
1171
                                 * The difference between versions 1.0 and
1172
                                 * 2.0 is here. For future versions of
1173
                                 * the player this may need to be modified.
1174
                                 */
1175
                                if (*(bptr + 1) == 0x02)
1176
                                   bptr += 8;
1177
                                else
1178
                                   bptr += 4;
1179
                                break;
1180

    
1181
                         case 6:
1182
                                /* This is the field containing the port
1183
                                 * number that RA-player is listening to.
1184
                                 */
1185
                                lport = (((u_char*)bptr)[0] << 8)
1186
                                + ((u_char *)bptr)[1];
1187
                                if (lport < 6970)
1188
                                   lport += 256;   /* don't know why */
1189
                                if (lport < 6970 || lport > 7170)
1190
                                   return 1;       /* failed */
1191

    
1192
                                /* try to get udp port between 6970 - 7170 */
1193
                                for (p = 6970; p < 7071; p++) {
1194
                                        if (udp_listen(INADDR_ANY,
1195
                                                       htons(p),
1196
                                                       so->so_laddr.s_addr,
1197
                                                       htons(lport),
1198
                                                       SS_FACCEPTONCE)) {
1199
                                                break;
1200
                                        }
1201
                                }
1202
                                if (p == 7071)
1203
                                   p = 0;
1204
                                *(u_char *)bptr++ = (p >> 8) & 0xff;
1205
                                *(u_char *)bptr++ = p & 0xff;
1206
                                ra = 0;
1207
                                return 1;   /* port redirected, we're done */
1208
                                break;
1209

    
1210
                         default:
1211
                                ra = 0;
1212
                        }
1213
                        ra++;
1214
                }
1215
                return 1;
1216

    
1217
         default:
1218
                /* Ooops, not emulated, won't call tcp_emu again */
1219
                so->so_emu = 0;
1220
                return 1;
1221
        }
1222
}
1223

    
1224
/*
1225
 * Do misc. config of SLiRP while its running.
1226
 * Return 0 if this connections is to be closed, 1 otherwise,
1227
 * return 2 if this is a command-line connection
1228
 */
1229
int tcp_ctl(struct socket *so)
1230
{
1231
    struct sbuf *sb = &so->so_snd;
1232
    struct ex_list *ex_ptr;
1233
    int do_pty;
1234

    
1235
    DEBUG_CALL("tcp_ctl");
1236
    DEBUG_ARG("so = %lx", (long )so);
1237

    
1238
    if (so->so_faddr.s_addr != vhost_addr.s_addr) {
1239
        /* Check if it's pty_exec */
1240
        for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
1241
            if (ex_ptr->ex_fport == so->so_fport &&
1242
                so->so_faddr.s_addr == ex_ptr->ex_addr.s_addr) {
1243
                if (ex_ptr->ex_pty == 3) {
1244
                    so->s = -1;
1245
                    so->extra = (void *)ex_ptr->ex_exec;
1246
                    return 1;
1247
                }
1248
                do_pty = ex_ptr->ex_pty;
1249
                DEBUG_MISC((dfd, " executing %s \n",ex_ptr->ex_exec));
1250
                return fork_exec(so, ex_ptr->ex_exec, do_pty);
1251
            }
1252
        }
1253
    }
1254
    sb->sb_cc =
1255
        snprintf(sb->sb_wptr, sb->sb_datalen - (sb->sb_wptr - sb->sb_data),
1256
                 "Error: No application configured.\r\n");
1257
    sb->sb_wptr += sb->sb_cc;
1258
    return 0;
1259
}