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/*
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:
8
 * 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
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 *    documentation and/or other materials provided with the distribution.
13
 * 3. All advertising materials mentioning features or use of this software
14
 *    must display the following acknowledgement:
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 *        This product includes software developed by the University of
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 *        California, Berkeley and its contributors.
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 * 4. Neither the name of the University nor the names of its contributors
18
 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
20
 *
21
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31
 * SUCH DAMAGE.
32
 *
33
 *        @(#)tcp_subr.c        8.1 (Berkeley) 6/10/93
34
 * tcp_subr.c,v 1.5 1994/10/08 22:39:58 phk Exp
35
 */
36

    
37
/*
38
 * Changes and additions relating to SLiRP
39
 * Copyright (c) 1995 Danny Gasparovski.
40
 * 
41
 * Please read the file COPYRIGHT for the 
42
 * terms and conditions of the copyright.
43
 */
44

    
45
#define WANT_SYS_IOCTL_H
46
#include <slirp.h>
47

    
48
/* patchable/settable parameters for tcp */
49
int         tcp_mssdflt = TCP_MSS;
50
int         tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ;
51
int        tcp_do_rfc1323 = 0;        /* Don't do rfc1323 performance enhancements */
52
int        tcp_rcvspace;        /* You may want to change this */
53
int        tcp_sndspace;        /* Keep small if you have an error prone link */
54

    
55
/*
56
 * Tcp initialization
57
 */
58
void
59
tcp_init()
60
{
61
        tcp_iss = 1;                /* wrong */
62
        tcb.so_next = tcb.so_prev = &tcb;
63
        
64
        /* tcp_rcvspace = our Window we advertise to the remote */
65
        tcp_rcvspace = TCP_RCVSPACE;
66
        tcp_sndspace = TCP_SNDSPACE;
67
        
68
        /* Make sure tcp_sndspace is at least 2*MSS */
69
        if (tcp_sndspace < 2*(min(if_mtu, if_mru) - sizeof(struct tcpiphdr)))
70
                tcp_sndspace = 2*(min(if_mtu, if_mru) - sizeof(struct tcpiphdr));
71
}
72

    
73
/*
74
 * Create template to be used to send tcp packets on a connection.
75
 * Call after host entry created, fills
76
 * in a skeletal tcp/ip header, minimizing the amount of work
77
 * necessary when the connection is used.
78
 */
79
/* struct tcpiphdr * */
80
void
81
tcp_template(tp)
82
        struct tcpcb *tp;
83
{
84
        struct socket *so = tp->t_socket;
85
        register struct tcpiphdr *n = &tp->t_template;
86

    
87
        n->ti_next = n->ti_prev = 0;
88
        n->ti_x1 = 0;
89
        n->ti_pr = IPPROTO_TCP;
90
        n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip));
91
        n->ti_src = so->so_faddr;
92
        n->ti_dst = so->so_laddr;
93
        n->ti_sport = so->so_fport;
94
        n->ti_dport = so->so_lport;
95
        
96
        n->ti_seq = 0;
97
        n->ti_ack = 0;
98
        n->ti_x2 = 0;
99
        n->ti_off = 5;
100
        n->ti_flags = 0;
101
        n->ti_win = 0;
102
        n->ti_sum = 0;
103
        n->ti_urp = 0;
104
}
105

    
106
/*
107
 * Send a single message to the TCP at address specified by
108
 * the given TCP/IP header.  If m == 0, then we make a copy
109
 * of the tcpiphdr at ti and send directly to the addressed host.
110
 * This is used to force keep alive messages out using the TCP
111
 * template for a connection tp->t_template.  If flags are given
112
 * then we send a message back to the TCP which originated the
113
 * segment ti, and discard the mbuf containing it and any other
114
 * attached mbufs.
115
 *
116
 * In any case the ack and sequence number of the transmitted
117
 * segment are as specified by the parameters.
118
 */
119
void
120
tcp_respond(tp, ti, m, ack, seq, flags)
121
        struct tcpcb *tp;
122
        register struct tcpiphdr *ti;
123
        register struct mbuf *m;
124
        tcp_seq ack, seq;
125
        int flags;
126
{
127
        register int tlen;
128
        int win = 0;
129

    
130
        DEBUG_CALL("tcp_respond");
131
        DEBUG_ARG("tp = %lx", (long)tp);
132
        DEBUG_ARG("ti = %lx", (long)ti);
133
        DEBUG_ARG("m = %lx", (long)m);
134
        DEBUG_ARG("ack = %u", ack);
135
        DEBUG_ARG("seq = %u", seq);
136
        DEBUG_ARG("flags = %x", flags);
137
        
138
        if (tp)
139
                win = sbspace(&tp->t_socket->so_rcv);
140
        if (m == 0) {
141
                if ((m = m_get()) == NULL)
142
                        return;
143
#ifdef TCP_COMPAT_42
144
                tlen = 1;
145
#else
146
                tlen = 0;
147
#endif
148
                m->m_data += if_maxlinkhdr;
149
                *mtod(m, struct tcpiphdr *) = *ti;
150
                ti = mtod(m, struct tcpiphdr *);
151
                flags = TH_ACK;
152
        } else {
153
                /* 
154
                 * ti points into m so the next line is just making
155
                 * the mbuf point to ti
156
                 */
157
                m->m_data = (caddr_t)ti;
158
                
159
                m->m_len = sizeof (struct tcpiphdr);
160
                tlen = 0;
161
#define xchg(a,b,type) { type t; t=a; a=b; b=t; }
162
                xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, u_int32_t);
163
                xchg(ti->ti_dport, ti->ti_sport, u_int16_t);
164
#undef xchg
165
        }
166
        ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen));
167
        tlen += sizeof (struct tcpiphdr);
168
        m->m_len = tlen;
169

    
170
        ti->ti_next = ti->ti_prev = 0;
171
        ti->ti_x1 = 0;
172
        ti->ti_seq = htonl(seq);
173
        ti->ti_ack = htonl(ack);
174
        ti->ti_x2 = 0;
175
        ti->ti_off = sizeof (struct tcphdr) >> 2;
176
        ti->ti_flags = flags;
177
        if (tp)
178
                ti->ti_win = htons((u_int16_t) (win >> tp->rcv_scale));
179
        else
180
                ti->ti_win = htons((u_int16_t)win);
181
        ti->ti_urp = 0;
182
        ti->ti_sum = 0;
183
        ti->ti_sum = cksum(m, tlen);
184
        ((struct ip *)ti)->ip_len = tlen;
185

    
186
        if(flags & TH_RST) 
187
          ((struct ip *)ti)->ip_ttl = MAXTTL;
188
        else 
189
          ((struct ip *)ti)->ip_ttl = ip_defttl;
190
        
191
        (void) ip_output((struct socket *)0, m);
192
}
193

    
194
/*
195
 * Create a new TCP control block, making an
196
 * empty reassembly queue and hooking it to the argument
197
 * protocol control block.
198
 */
199
struct tcpcb *
200
tcp_newtcpcb(so)
201
        struct socket *so;
202
{
203
        register struct tcpcb *tp;
204
        
205
        tp = (struct tcpcb *)malloc(sizeof(*tp));
206
        if (tp == NULL)
207
                return ((struct tcpcb *)0);
208
        
209
        memset((char *) tp, 0, sizeof(struct tcpcb));
210
        tp->seg_next = tp->seg_prev = (tcpiphdrp_32)tp;
211
        tp->t_maxseg = tcp_mssdflt;
212
        
213
        tp->t_flags = tcp_do_rfc1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0;
214
        tp->t_socket = so;
215
        
216
        /*
217
         * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
218
         * rtt estimate.  Set rttvar so that srtt + 2 * rttvar gives
219
         * reasonable initial retransmit time.
220
         */
221
        tp->t_srtt = TCPTV_SRTTBASE;
222
        tp->t_rttvar = tcp_rttdflt * PR_SLOWHZ << 2;
223
        tp->t_rttmin = TCPTV_MIN;
224

    
225
        TCPT_RANGESET(tp->t_rxtcur, 
226
            ((TCPTV_SRTTBASE >> 2) + (TCPTV_SRTTDFLT << 2)) >> 1,
227
            TCPTV_MIN, TCPTV_REXMTMAX);
228

    
229
        tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
230
        tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
231
        tp->t_state = TCPS_CLOSED;
232
        
233
        so->so_tcpcb = tp;
234

    
235
        return (tp);
236
}
237

    
238
/*
239
 * Drop a TCP connection, reporting
240
 * the specified error.  If connection is synchronized,
241
 * then send a RST to peer.
242
 */
243
struct tcpcb *tcp_drop(struct tcpcb *tp, int err) 
244
{
245
/* tcp_drop(tp, errno)
246
        register struct tcpcb *tp;
247
        int errno;
248
{
249
*/
250

    
251
        DEBUG_CALL("tcp_drop");
252
        DEBUG_ARG("tp = %lx", (long)tp);
253
        DEBUG_ARG("errno = %d", errno);
254
        
255
        if (TCPS_HAVERCVDSYN(tp->t_state)) {
256
                tp->t_state = TCPS_CLOSED;
257
                (void) tcp_output(tp);
258
                tcpstat.tcps_drops++;
259
        } else
260
                tcpstat.tcps_conndrops++;
261
/*        if (errno == ETIMEDOUT && tp->t_softerror)
262
 *                errno = tp->t_softerror;
263
 */
264
/*        so->so_error = errno; */
265
        return (tcp_close(tp));
266
}
267

    
268
/*
269
 * Close a TCP control block:
270
 *        discard all space held by the tcp
271
 *        discard internet protocol block
272
 *        wake up any sleepers
273
 */
274
struct tcpcb *
275
tcp_close(tp)
276
        register struct tcpcb *tp;
277
{
278
        register struct tcpiphdr *t;
279
        struct socket *so = tp->t_socket;
280
        register struct mbuf *m;
281

    
282
        DEBUG_CALL("tcp_close");
283
        DEBUG_ARG("tp = %lx", (long )tp);
284
        
285
        /* free the reassembly queue, if any */
286
        t = (struct tcpiphdr *) tp->seg_next;
287
        while (t != (struct tcpiphdr *)tp) {
288
                t = (struct tcpiphdr *)t->ti_next;
289
                m = (struct mbuf *) REASS_MBUF((struct tcpiphdr *)t->ti_prev);
290
                remque_32((struct tcpiphdr *) t->ti_prev);
291
                m_freem(m);
292
        }
293
        /* It's static */
294
/*        if (tp->t_template)
295
 *                (void) m_free(dtom(tp->t_template));
296
 */
297
/*        free(tp, M_PCB);  */
298
        free(tp);
299
        so->so_tcpcb = 0;
300
        soisfdisconnected(so);
301
        /* clobber input socket cache if we're closing the cached connection */
302
        if (so == tcp_last_so)
303
                tcp_last_so = &tcb;
304
        close(so->s);
305
        sbfree(&so->so_rcv);
306
        sbfree(&so->so_snd);
307
        sofree(so);
308
        tcpstat.tcps_closed++;
309
        return ((struct tcpcb *)0);
310
}
311

    
312
void
313
tcp_drain()
314
{
315
        /* XXX */
316
}
317

    
318
/*
319
 * When a source quench is received, close congestion window
320
 * to one segment.  We will gradually open it again as we proceed.
321
 */
322

    
323
#ifdef notdef
324

    
325
void
326
tcp_quench(i, errno)
327

    
328
        int errno;
329
{
330
        struct tcpcb *tp = intotcpcb(inp);
331

    
332
        if (tp)
333
                tp->snd_cwnd = tp->t_maxseg;
334
}
335

    
336
#endif /* notdef */
337

    
338
/*
339
 * TCP protocol interface to socket abstraction.
340
 */
341

    
342
/*
343
 * User issued close, and wish to trail through shutdown states:
344
 * if never received SYN, just forget it.  If got a SYN from peer,
345
 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
346
 * If already got a FIN from peer, then almost done; go to LAST_ACK
347
 * state.  In all other cases, have already sent FIN to peer (e.g.
348
 * after PRU_SHUTDOWN), and just have to play tedious game waiting
349
 * for peer to send FIN or not respond to keep-alives, etc.
350
 * We can let the user exit from the close as soon as the FIN is acked.
351
 */
352
void
353
tcp_sockclosed(tp)
354
        struct tcpcb *tp;
355
{
356

    
357
        DEBUG_CALL("tcp_sockclosed");
358
        DEBUG_ARG("tp = %lx", (long)tp);
359
        
360
        switch (tp->t_state) {
361

    
362
        case TCPS_CLOSED:
363
        case TCPS_LISTEN:
364
        case TCPS_SYN_SENT:
365
                tp->t_state = TCPS_CLOSED;
366
                tp = tcp_close(tp);
367
                break;
368

    
369
        case TCPS_SYN_RECEIVED:
370
        case TCPS_ESTABLISHED:
371
                tp->t_state = TCPS_FIN_WAIT_1;
372
                break;
373

    
374
        case TCPS_CLOSE_WAIT:
375
                tp->t_state = TCPS_LAST_ACK;
376
                break;
377
        }
378
/*        soisfdisconnecting(tp->t_socket); */
379
        if (tp && tp->t_state >= TCPS_FIN_WAIT_2)
380
                soisfdisconnected(tp->t_socket);
381
        if (tp)
382
                tcp_output(tp);
383
}
384

    
385
/* 
386
 * Connect to a host on the Internet
387
 * Called by tcp_input
388
 * Only do a connect, the tcp fields will be set in tcp_input
389
 * return 0 if there's a result of the connect,
390
 * else return -1 means we're still connecting
391
 * The return value is almost always -1 since the socket is
392
 * nonblocking.  Connect returns after the SYN is sent, and does 
393
 * not wait for ACK+SYN.
394
 */
395
int tcp_fconnect(so)
396
     struct socket *so;
397
{
398
  int ret=0;
399
  
400
  DEBUG_CALL("tcp_fconnect");
401
  DEBUG_ARG("so = %lx", (long )so);
402

    
403
  if( (ret=so->s=socket(AF_INET,SOCK_STREAM,0)) >= 0) {
404
    int opt, s=so->s;
405
    struct sockaddr_in addr;
406

    
407
    fd_nonblock(s);
408
    opt = 1;
409
    setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(opt ));
410
    opt = 1;
411
    setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(opt ));
412
    
413
    addr.sin_family = AF_INET;
414
    if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) {
415
      /* It's an alias */
416
      switch(ntohl(so->so_faddr.s_addr) & 0xff) {
417
      case CTL_DNS:
418
        addr.sin_addr = dns_addr;
419
        break;
420
      case CTL_ALIAS:
421
      default:
422
        addr.sin_addr = loopback_addr;
423
        break;
424
      }
425
    } else
426
      addr.sin_addr = so->so_faddr;
427
    addr.sin_port = so->so_fport;
428
    
429
    DEBUG_MISC((dfd, " connect()ing, addr.sin_port=%d, "
430
                "addr.sin_addr.s_addr=%.16s\n", 
431
                ntohs(addr.sin_port), inet_ntoa(addr.sin_addr)));
432
    /* We don't care what port we get */
433
    ret = connect(s,(struct sockaddr *)&addr,sizeof (addr));
434
    
435
    /*
436
     * If it's not in progress, it failed, so we just return 0,
437
     * without clearing SS_NOFDREF
438
     */
439
    soisfconnecting(so);
440
  }
441

    
442
  return(ret);
443
}
444

    
445
/*
446
 * Accept the socket and connect to the local-host
447
 * 
448
 * We have a problem. The correct thing to do would be
449
 * to first connect to the local-host, and only if the
450
 * connection is accepted, then do an accept() here.
451
 * But, a) we need to know who's trying to connect 
452
 * to the socket to be able to SYN the local-host, and
453
 * b) we are already connected to the foreign host by
454
 * the time it gets to accept(), so... We simply accept
455
 * here and SYN the local-host.
456
 */ 
457
void
458
tcp_connect(inso)
459
        struct socket *inso;
460
{
461
        struct socket *so;
462
        struct sockaddr_in addr;
463
        int addrlen = sizeof(struct sockaddr_in);
464
        struct tcpcb *tp;
465
        int s, opt;
466

    
467
        DEBUG_CALL("tcp_connect");
468
        DEBUG_ARG("inso = %lx", (long)inso);
469
        
470
        /*
471
         * If it's an SS_ACCEPTONCE socket, no need to socreate()
472
         * another socket, just use the accept() socket.
473
         */
474
        if (inso->so_state & SS_FACCEPTONCE) {
475
                /* FACCEPTONCE already have a tcpcb */
476
                so = inso;
477
        } else {
478
                if ((so = socreate()) == NULL) {
479
                        /* If it failed, get rid of the pending connection */
480
                        close(accept(inso->s,(struct sockaddr *)&addr,&addrlen));
481
                        return;
482
                }
483
                if (tcp_attach(so) < 0) {
484
                        free(so); /* NOT sofree */
485
                        return;
486
                }
487
                so->so_laddr = inso->so_laddr;
488
                so->so_lport = inso->so_lport;
489
        }
490
        
491
        (void) tcp_mss(sototcpcb(so), 0);
492

    
493
        if ((s = accept(inso->s,(struct sockaddr *)&addr,&addrlen)) < 0) {
494
                tcp_close(sototcpcb(so)); /* This will sofree() as well */
495
                return;
496
        }
497
        fd_nonblock(s);
498
        opt = 1;
499
        setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
500
        opt = 1;
501
        setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
502
        
503
        so->so_fport = addr.sin_port;
504
        so->so_faddr = addr.sin_addr;
505
        /* Translate connections from localhost to the real hostname */
506
        if (so->so_faddr.s_addr == 0 || so->so_faddr.s_addr == loopback_addr.s_addr)
507
           so->so_faddr = our_addr;
508
        
509
        /* Close the accept() socket, set right state */
510
        if (inso->so_state & SS_FACCEPTONCE) {
511
                close(so->s); /* If we only accept once, close the accept() socket */
512
                so->so_state = SS_NOFDREF; /* Don't select it yet, even though we have an FD */
513
                                           /* if it's not FACCEPTONCE, it's already NOFDREF */
514
        }
515
        so->s = s;
516
        
517
        so->so_iptos = tcp_tos(so);
518
        tp = sototcpcb(so);
519

    
520
        tcp_template(tp);
521
        
522
        /* Compute window scaling to request.  */
523
/*        while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
524
 *                (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
525
 *                tp->request_r_scale++;
526
 */
527

    
528
/*        soisconnecting(so); */ /* NOFDREF used instead */
529
        tcpstat.tcps_connattempt++;
530
        
531
        tp->t_state = TCPS_SYN_SENT;
532
        tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
533
        tp->iss = tcp_iss; 
534
        tcp_iss += TCP_ISSINCR/2;
535
        tcp_sendseqinit(tp);
536
        tcp_output(tp);
537
}
538

    
539
/*
540
 * Attach a TCPCB to a socket.
541
 */
542
int
543
tcp_attach(so)
544
        struct socket *so;
545
{
546
        if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
547
           return -1;
548
        
549
        insque(so, &tcb);
550

    
551
        return 0;
552
}
553

    
554
/*
555
 * Set the socket's type of service field
556
 */
557
struct tos_t tcptos[] = {
558
          {0, 20, IPTOS_THROUGHPUT, 0},        /* ftp data */
559
          {21, 21, IPTOS_LOWDELAY,  EMU_FTP},        /* ftp control */
560
          {0, 23, IPTOS_LOWDELAY, 0},        /* telnet */
561
          {0, 80, IPTOS_THROUGHPUT, 0},        /* WWW */
562
          {0, 513, IPTOS_LOWDELAY, EMU_RLOGIN|EMU_NOCONNECT},        /* rlogin */
563
          {0, 514, IPTOS_LOWDELAY, EMU_RSH|EMU_NOCONNECT},        /* shell */
564
          {0, 544, IPTOS_LOWDELAY, EMU_KSH},                /* kshell */
565
          {0, 543, IPTOS_LOWDELAY, 0},        /* klogin */
566
          {0, 6667, IPTOS_THROUGHPUT, EMU_IRC},        /* IRC */
567
          {0, 6668, IPTOS_THROUGHPUT, EMU_IRC},        /* IRC undernet */
568
          {0, 7070, IPTOS_LOWDELAY, EMU_REALAUDIO }, /* RealAudio control */
569
          {0, 113, IPTOS_LOWDELAY, EMU_IDENT }, /* identd protocol */
570
          {0, 0, 0, 0}
571
};
572

    
573
struct emu_t *tcpemu = 0;
574
                
575
/*
576
 * Return TOS according to the above table
577
 */
578
u_int8_t
579
tcp_tos(so)
580
        struct socket *so;
581
{
582
        int i = 0;
583
        struct emu_t *emup;
584
        
585
        while(tcptos[i].tos) {
586
                if ((tcptos[i].fport && (ntohs(so->so_fport) == tcptos[i].fport)) ||
587
                    (tcptos[i].lport && (ntohs(so->so_lport) == tcptos[i].lport))) {
588
                        so->so_emu = tcptos[i].emu;
589
                        return tcptos[i].tos;
590
                }
591
                i++;
592
        }
593
        
594
        /* Nope, lets see if there's a user-added one */
595
        for (emup = tcpemu; emup; emup = emup->next) {
596
                if ((emup->fport && (ntohs(so->so_fport) == emup->fport)) ||
597
                    (emup->lport && (ntohs(so->so_lport) == emup->lport))) {
598
                        so->so_emu = emup->emu;
599
                        return emup->tos;
600
                }
601
        }
602
        
603
        return 0;
604
}
605

    
606
int do_echo = -1;
607

    
608
/*
609
 * Emulate programs that try and connect to us
610
 * This includes ftp (the data connection is
611
 * initiated by the server) and IRC (DCC CHAT and
612
 * DCC SEND) for now
613
 * 
614
 * NOTE: It's possible to crash SLiRP by sending it
615
 * unstandard strings to emulate... if this is a problem,
616
 * more checks are needed here
617
 *
618
 * XXX Assumes the whole command came in one packet
619
 *                                            
620
 * XXX Some ftp clients will have their TOS set to
621
 * LOWDELAY and so Nagel will kick in.  Because of this,
622
 * we'll get the first letter, followed by the rest, so
623
 * we simply scan for ORT instead of PORT...
624
 * DCC doesn't have this problem because there's other stuff
625
 * in the packet before the DCC command.
626
 * 
627
 * Return 1 if the mbuf m is still valid and should be 
628
 * sbappend()ed
629
 * 
630
 * NOTE: if you return 0 you MUST m_free() the mbuf!
631
 */
632
int
633
tcp_emu(so, m)
634
        struct socket *so;
635
        struct mbuf *m;
636
{
637
        u_int n1, n2, n3, n4, n5, n6;
638
        char buff[256];
639
        u_int32_t laddr;
640
        u_int lport;
641
        char *bptr;
642
        
643
        DEBUG_CALL("tcp_emu");
644
        DEBUG_ARG("so = %lx", (long)so);
645
        DEBUG_ARG("m = %lx", (long)m);
646
        
647
        switch(so->so_emu) {
648
                int x, i;
649
                
650
         case EMU_IDENT:
651
                /*
652
                 * Identification protocol as per rfc-1413
653
                 */
654
                
655
                {
656
                        struct socket *tmpso;
657
                        struct sockaddr_in addr;
658
                        int addrlen = sizeof(struct sockaddr_in);
659
                        struct sbuf *so_rcv = &so->so_rcv;
660
                        
661
                        memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
662
                        so_rcv->sb_wptr += m->m_len;
663
                        so_rcv->sb_rptr += m->m_len;
664
                        m->m_data[m->m_len] = 0; /* NULL terminate */
665
                        if (strchr(m->m_data, '\r') || strchr(m->m_data, '\n')) {
666
                                if (sscanf(so_rcv->sb_data, "%d%*[ ,]%d", &n1, &n2) == 2) {
667
                                        HTONS(n1);
668
                                        HTONS(n2);
669
                                        /* n2 is the one on our host */
670
                                        for (tmpso = tcb.so_next; tmpso != &tcb; tmpso = tmpso->so_next) {
671
                                                if (tmpso->so_laddr.s_addr == so->so_laddr.s_addr &&
672
                                                    tmpso->so_lport == n2 &&
673
                                                    tmpso->so_faddr.s_addr == so->so_faddr.s_addr &&
674
                                                    tmpso->so_fport == n1) {
675
                                                        if (getsockname(tmpso->s,
676
                                                                (struct sockaddr *)&addr, &addrlen) == 0)
677
                                                           n2 = ntohs(addr.sin_port);
678
                                                        break;
679
                                                }
680
                                        }
681
                                }
682
                                so_rcv->sb_cc = sprintf(so_rcv->sb_data, "%d,%d\r\n", n1, n2);
683
                                so_rcv->sb_rptr = so_rcv->sb_data;
684
                                so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
685
                        }
686
                        m_free(m);
687
                        return 0;
688
                }
689
                
690
#if 0
691
         case EMU_RLOGIN:
692
                /*
693
                 * Rlogin emulation
694
                 * First we accumulate all the initial option negotiation,
695
                 * then fork_exec() rlogin according to the  options
696
                 */
697
                {
698
                        int i, i2, n;
699
                        char *ptr;
700
                        char args[100];
701
                        char term[100];
702
                        struct sbuf *so_snd = &so->so_snd;
703
                        struct sbuf *so_rcv = &so->so_rcv;
704
                        
705
                        /* First check if they have a priveladged port, or too much data has arrived */
706
                        if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
707
                            (m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
708
                                memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
709
                                so_snd->sb_wptr += 18;
710
                                so_snd->sb_cc += 18;
711
                                tcp_sockclosed(sototcpcb(so));
712
                                m_free(m);
713
                                return 0;
714
                        }
715
                        
716
                        /* Append the current data */
717
                        memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
718
                        so_rcv->sb_wptr += m->m_len;
719
                        so_rcv->sb_rptr += m->m_len;
720
                        m_free(m);
721
                        
722
                        /*
723
                         * Check if we have all the initial options,
724
                         * and build argument list to rlogin while we're here
725
                         */
726
                        n = 0;
727
                        ptr = so_rcv->sb_data;
728
                        args[0] = 0;
729
                        term[0] = 0;
730
                        while (ptr < so_rcv->sb_wptr) {
731
                                if (*ptr++ == 0) {
732
                                        n++;
733
                                        if (n == 2) {
734
                                                sprintf(args, "rlogin -l %s %s",
735
                                                        ptr, inet_ntoa(so->so_faddr));
736
                                        } else if (n == 3) {
737
                                                i2 = so_rcv->sb_wptr - ptr;
738
                                                for (i = 0; i < i2; i++) {
739
                                                        if (ptr[i] == '/') {
740
                                                                ptr[i] = 0;
741
#ifdef HAVE_SETENV
742
                                                                sprintf(term, "%s", ptr);
743
#else
744
                                                                sprintf(term, "TERM=%s", ptr);
745
#endif
746
                                                                ptr[i] = '/';
747
                                                                break;
748
                                                        }
749
                                                }
750
                                        }
751
                                }
752
                        }
753
                        
754
                        if (n != 4)
755
                           return 0;
756
                        
757
                        /* We have it, set our term variable and fork_exec() */
758
#ifdef HAVE_SETENV
759
                        setenv("TERM", term, 1);
760
#else
761
                        putenv(term);
762
#endif
763
                        fork_exec(so, args, 2);
764
                        term[0] = 0;
765
                        so->so_emu = 0;
766
                        
767
                        /* And finally, send the client a 0 character */
768
                        so_snd->sb_wptr[0] = 0;
769
                        so_snd->sb_wptr++;
770
                        so_snd->sb_cc++;
771
                        
772
                        return 0;
773
                }
774
                
775
         case EMU_RSH:
776
                /*
777
                 * rsh emulation
778
                 * First we accumulate all the initial option negotiation,
779
                 * then rsh_exec() rsh according to the  options
780
                 */
781
                {
782
                        int  n;
783
                        char *ptr;
784
                        char *user;
785
                        char *args;
786
                        struct sbuf *so_snd = &so->so_snd;
787
                        struct sbuf *so_rcv = &so->so_rcv;
788
                        
789
                        /* First check if they have a priveladged port, or too much data has arrived */
790
                        if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
791
                            (m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
792
                                memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
793
                                so_snd->sb_wptr += 18;
794
                                so_snd->sb_cc += 18;
795
                                tcp_sockclosed(sototcpcb(so));
796
                                m_free(m);
797
                                return 0;
798
                        }
799
                        
800
                        /* Append the current data */
801
                        memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
802
                        so_rcv->sb_wptr += m->m_len;
803
                        so_rcv->sb_rptr += m->m_len;
804
                        m_free(m);
805
                        
806
                        /*
807
                         * Check if we have all the initial options,
808
                         * and build argument list to rlogin while we're here
809
                         */
810
                        n = 0;
811
                        ptr = so_rcv->sb_data;
812
                        user="";
813
                        args="";
814
                        if (so->extra==NULL) {
815
                                struct socket *ns;
816
                                struct tcpcb* tp;
817
                                int port=atoi(ptr);
818
                                if (port <= 0) return 0;
819
                if (port > 1023 || port < 512) {
820
                  memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
821
                  so_snd->sb_wptr += 18;
822
                  so_snd->sb_cc += 18;
823
                  tcp_sockclosed(sototcpcb(so));
824
                  return 0;
825
                }
826
                                if ((ns=socreate()) == NULL)
827
                  return 0;
828
                                if (tcp_attach(ns)<0) {
829
                  free(ns);
830
                  return 0;
831
                                }
832

    
833
                                ns->so_laddr=so->so_laddr;
834
                                ns->so_lport=htons(port);
835

    
836
                                (void) tcp_mss(sototcpcb(ns), 0);
837

    
838
                                ns->so_faddr=so->so_faddr;
839
                                ns->so_fport=htons(IPPORT_RESERVED-1); /* Use a fake port. */
840

    
841
                                if (ns->so_faddr.s_addr == 0 || 
842
                                        ns->so_faddr.s_addr == loopback_addr.s_addr)
843
                  ns->so_faddr = our_addr;
844

    
845
                                ns->so_iptos = tcp_tos(ns);
846
                                tp = sototcpcb(ns);
847
                
848
                                tcp_template(tp);
849
                
850
                                /* Compute window scaling to request.  */
851
                                /*        while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
852
                                 *                (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
853
                                 *                tp->request_r_scale++;
854
                                 */
855

    
856
                /*soisfconnecting(ns);*/
857

    
858
                                tcpstat.tcps_connattempt++;
859
                                        
860
                                tp->t_state = TCPS_SYN_SENT;
861
                                tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
862
                                tp->iss = tcp_iss; 
863
                                tcp_iss += TCP_ISSINCR/2;
864
                                tcp_sendseqinit(tp);
865
                                tcp_output(tp);
866
                                so->extra=ns;
867
                        }
868
                        while (ptr < so_rcv->sb_wptr) {
869
              if (*ptr++ == 0) {
870
                n++;
871
                if (n == 2) {
872
                  user=ptr;
873
                } else if (n == 3) {
874
                  args=ptr;
875
                }
876
              }
877
                        }
878
                        
879
                        if (n != 4)
880
              return 0;
881
                        
882
                        rsh_exec(so,so->extra, user, inet_ntoa(so->so_faddr), args);
883
                        so->so_emu = 0;
884
                        so->extra=NULL;
885
                        
886
                        /* And finally, send the client a 0 character */
887
                        so_snd->sb_wptr[0] = 0;
888
                        so_snd->sb_wptr++;
889
                        so_snd->sb_cc++;
890
                        
891
                        return 0;
892
                }
893

    
894
         case EMU_CTL:
895
                {
896
                        int num;
897
                        struct sbuf *so_snd = &so->so_snd;
898
                        struct sbuf *so_rcv = &so->so_rcv;
899
                        
900
                        /*
901
                         * If there is binary data here, we save it in so->so_m
902
                         */
903
                        if (!so->so_m) {
904
                          int rxlen;
905
                          char *rxdata;
906
                          rxdata=mtod(m, char *);
907
                          for (rxlen=m->m_len; rxlen; rxlen--) {
908
                            if (*rxdata++ & 0x80) {
909
                              so->so_m = m;
910
                              return 0;
911
                            }
912
                          }
913
                        } /* if(so->so_m==NULL) */
914
                        
915
                        /*
916
                         * Append the line
917
                         */
918
                        sbappendsb(so_rcv, m);
919
                        
920
                        /* To avoid going over the edge of the buffer, we reset it */
921
                        if (so_snd->sb_cc == 0)
922
                           so_snd->sb_wptr = so_snd->sb_rptr = so_snd->sb_data;
923
                        
924
                        /*
925
                         * A bit of a hack:
926
                         * If the first packet we get here is 1 byte long, then it
927
                         * was done in telnet character mode, therefore we must echo
928
                         * the characters as they come.  Otherwise, we echo nothing,
929
                         * because in linemode, the line is already echoed
930
                         * XXX two or more control connections won't work
931
                         */
932
                        if (do_echo == -1) {
933
                                if (m->m_len == 1) do_echo = 1;
934
                                else do_echo = 0;
935
                        }
936
                        if (do_echo) {
937
                          sbappendsb(so_snd, m);
938
                          m_free(m);
939
                          tcp_output(sototcpcb(so)); /* XXX */
940
                        } else
941
                          m_free(m);
942
                        
943
                        num = 0;
944
                        while (num < so->so_rcv.sb_cc) {
945
                                if (*(so->so_rcv.sb_rptr + num) == '\n' ||
946
                                    *(so->so_rcv.sb_rptr + num) == '\r') {
947
                                        int n;
948
                                        
949
                                        *(so_rcv->sb_rptr + num) = 0;
950
                                        if (ctl_password && !ctl_password_ok) {
951
                                                /* Need a password */
952
                                                if (sscanf(so_rcv->sb_rptr, "pass %256s", buff) == 1) {
953
                                                        if (strcmp(buff, ctl_password) == 0) {
954
                                                                ctl_password_ok = 1;
955
                                                                n = sprintf(so_snd->sb_wptr,
956
                                                                            "Password OK.\r\n");
957
                                                                goto do_prompt;
958
                                                        }
959
                                                }
960
                                                n = sprintf(so_snd->sb_wptr,
961
                                         "Error: Password required, log on with \"pass PASSWORD\"\r\n");
962
                                                goto do_prompt;
963
                                        }
964
                                        cfg_quitting = 0;
965
                                        n = do_config(so_rcv->sb_rptr, so, PRN_SPRINTF);
966
                                        if (!cfg_quitting) {
967
                                                /* Register the printed data */
968
do_prompt:
969
                                                so_snd->sb_cc += n;
970
                                                so_snd->sb_wptr += n;
971
                                                /* Add prompt */
972
                                                n = sprintf(so_snd->sb_wptr, "Slirp> ");
973
                                                so_snd->sb_cc += n;
974
                                                so_snd->sb_wptr += n;
975
                                        }
976
                                        /* Drop so_rcv data */
977
                                        so_rcv->sb_cc = 0;
978
                                        so_rcv->sb_wptr = so_rcv->sb_rptr = so_rcv->sb_data;
979
                                        tcp_output(sototcpcb(so)); /* Send the reply */
980
                                }
981
                                num++;
982
                        }
983
                        return 0;
984
                }
985
#endif                
986
        case EMU_FTP: /* ftp */
987
                *(m->m_data+m->m_len) = 0; /* NULL terminate for strstr */
988
                if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
989
                        /*
990
                         * Need to emulate the PORT command
991
                         */                        
992
                        x = sscanf(bptr, "ORT %d,%d,%d,%d,%d,%d\r\n%256[^\177]", 
993
                                   &n1, &n2, &n3, &n4, &n5, &n6, buff);
994
                        if (x < 6)
995
                           return 1;
996
                        
997
                        laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
998
                        lport = htons((n5 << 8) | (n6));
999
                        
1000
                        if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL)
1001
                           return 1;
1002
                        
1003
                        n6 = ntohs(so->so_fport);
1004
                        
1005
                        n5 = (n6 >> 8) & 0xff;
1006
                        n6 &= 0xff;
1007
                        
1008
                        laddr = ntohl(so->so_faddr.s_addr);
1009
                        
1010
                        n1 = ((laddr >> 24) & 0xff);
1011
                        n2 = ((laddr >> 16) & 0xff);
1012
                        n3 = ((laddr >> 8)  & 0xff);
1013
                        n4 =  (laddr & 0xff);
1014
                        
1015
                        m->m_len = bptr - m->m_data; /* Adjust length */
1016
                        m->m_len += sprintf(bptr,"ORT %d,%d,%d,%d,%d,%d\r\n%s", 
1017
                                            n1, n2, n3, n4, n5, n6, x==7?buff:"");
1018
                        return 1;
1019
                } else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
1020
                        /*
1021
                         * Need to emulate the PASV response
1022
                         */
1023
                        x = sscanf(bptr, "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%256[^\177]",
1024
                                   &n1, &n2, &n3, &n4, &n5, &n6, buff);
1025
                        if (x < 6)
1026
                           return 1;
1027
                        
1028
                        laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
1029
                        lport = htons((n5 << 8) | (n6));
1030
                        
1031
                        if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL)
1032
                           return 1;
1033
                        
1034
                        n6 = ntohs(so->so_fport);
1035
                        
1036
                        n5 = (n6 >> 8) & 0xff;
1037
                        n6 &= 0xff;
1038
                        
1039
                        laddr = ntohl(so->so_faddr.s_addr);
1040
                        
1041
                        n1 = ((laddr >> 24) & 0xff);
1042
                        n2 = ((laddr >> 16) & 0xff);
1043
                        n3 = ((laddr >> 8)  & 0xff);
1044
                        n4 =  (laddr & 0xff);
1045
                        
1046
                        m->m_len = bptr - m->m_data; /* Adjust length */
1047
                        m->m_len += sprintf(bptr,"27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
1048
                                            n1, n2, n3, n4, n5, n6, x==7?buff:"");
1049
                        
1050
                        return 1;
1051
                }
1052
                
1053
                return 1;
1054
                                   
1055
         case EMU_KSH:
1056
                /*
1057
                 * The kshell (Kerberos rsh) and shell services both pass
1058
                 * a local port port number to carry signals to the server
1059
                 * and stderr to the client.  It is passed at the beginning
1060
                 * of the connection as a NUL-terminated decimal ASCII string.
1061
                 */
1062
                so->so_emu = 0;
1063
                for (lport = 0, i = 0; i < m->m_len-1; ++i) {
1064
                        if (m->m_data[i] < '0' || m->m_data[i] > '9')
1065
                                return 1;       /* invalid number */
1066
                        lport *= 10;
1067
                        lport += m->m_data[i] - '0';
1068
                }
1069
                if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
1070
                    (so = solisten(0, so->so_laddr.s_addr, htons(lport), SS_FACCEPTONCE)) != NULL)
1071
                        m->m_len = sprintf(m->m_data, "%d", ntohs(so->so_fport))+1;
1072
                return 1;
1073
                
1074
         case EMU_IRC:
1075
                /*
1076
                 * Need to emulate DCC CHAT, DCC SEND and DCC MOVE
1077
                 */
1078
                *(m->m_data+m->m_len) = 0; /* NULL terminate the string for strstr */
1079
                if ((bptr = (char *)strstr(m->m_data, "DCC")) == NULL)
1080
                         return 1;
1081
                
1082
                /* The %256s is for the broken mIRC */
1083
                if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) {
1084
                        if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1085
                                return 1;
1086
                        
1087
                        m->m_len = bptr - m->m_data; /* Adjust length */
1088
                        m->m_len += sprintf(bptr, "DCC CHAT chat %lu %u%c\n",
1089
                             (unsigned long)ntohl(so->so_faddr.s_addr),
1090
                             ntohs(so->so_fport), 1);
1091
                } else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
1092
                        if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1093
                                return 1;
1094
                        
1095
                        m->m_len = bptr - m->m_data; /* Adjust length */
1096
                        m->m_len += sprintf(bptr, "DCC SEND %s %lu %u %u%c\n", 
1097
                              buff, (unsigned long)ntohl(so->so_faddr.s_addr),
1098
                              ntohs(so->so_fport), n1, 1);
1099
                } else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
1100
                        if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1101
                                return 1;
1102
                        
1103
                        m->m_len = bptr - m->m_data; /* Adjust length */
1104
                        m->m_len += sprintf(bptr, "DCC MOVE %s %lu %u %u%c\n",
1105
                              buff, (unsigned long)ntohl(so->so_faddr.s_addr),
1106
                              ntohs(so->so_fport), n1, 1);
1107
                }
1108
                return 1;
1109

    
1110
         case EMU_REALAUDIO:
1111
                /* 
1112
                 * RealAudio emulation - JP. We must try to parse the incoming
1113
                 * data and try to find the two characters that contain the
1114
                 * port number. Then we redirect an udp port and replace the
1115
                 * number with the real port we got.
1116
                 *
1117
                 * The 1.0 beta versions of the player are not supported
1118
                 * any more.
1119
                 * 
1120
                 * A typical packet for player version 1.0 (release version):
1121
                 *        
1122
                 * 0000:50 4E 41 00 05 
1123
                 * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 .....?..g?l?c..P
1124
                 * 0010:4E 43 4C 49 45 4E 54 20 31 30 31 20 41 4C 50 48 NCLIENT 101 ALPH
1125
                 * 0020:41 6C 00 00 52 00 17 72 61 66 69 6C 65 73 2F 76 Al..R..rafiles/v
1126
                 * 0030:6F 61 2F 65 6E 67 6C 69 73 68 5F 2E 72 61 79 42 oa/english_.rayB
1127
                 *         
1128
                 * Now the port number 0x1BD7 is found at offset 0x04 of the
1129
                 * Now the port number 0x1BD7 is found at offset 0x04 of the
1130
                 * second packet. This time we received five bytes first and
1131
                 * then the rest. You never know how many bytes you get.
1132
                 *
1133
                 * A typical packet for player version 2.0 (beta):
1134
                 *        
1135
                 * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA...........?.
1136
                 * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .gux?c..Win2.0.0
1137
                 * 0020:2E 35 6C 00 00 52 00 1C 72 61 66 69 6C 65 73 2F .5l..R..rafiles/
1138
                 * 0030:77 65 62 73 69 74 65 2F 32 30 72 65 6C 65 61 73 website/20releas
1139
                 * 0040:65 2E 72 61 79 53 00 00 06 36 42                e.rayS...6B
1140
                 *        
1141
                 * Port number 0x1BC1 is found at offset 0x0d.
1142
                 *      
1143
                 * This is just a horrible switch statement. Variable ra tells
1144
                 * us where we're going.
1145
                 */
1146
                
1147
                bptr = m->m_data;
1148
                while (bptr < m->m_data + m->m_len) {
1149
                        u_short p;
1150
                        static int ra = 0;
1151
                        char ra_tbl[4]; 
1152
                        
1153
                        ra_tbl[0] = 0x50;
1154
                        ra_tbl[1] = 0x4e;
1155
                        ra_tbl[2] = 0x41;
1156
                        ra_tbl[3] = 0;
1157
                        
1158
                        switch (ra) {
1159
                         case 0:
1160
                         case 2:
1161
                         case 3:
1162
                                if (*bptr++ != ra_tbl[ra]) {
1163
                                        ra = 0;
1164
                                        continue;
1165
                                }
1166
                                break;
1167
                                
1168
                         case 1:
1169
                                /*
1170
                                 * We may get 0x50 several times, ignore them
1171
                                 */
1172
                                if (*bptr == 0x50) {
1173
                                        ra = 1;
1174
                                        bptr++;
1175
                                        continue;
1176
                                } else if (*bptr++ != ra_tbl[ra]) {
1177
                                        ra = 0;
1178
                                        continue;
1179
                                }
1180
                                break;
1181
                                
1182
                         case 4: 
1183
                                /* 
1184
                                 * skip version number
1185
                                 */
1186
                                bptr++;
1187
                                break;
1188
                                
1189
                         case 5: 
1190
                                /*
1191
                                 * The difference between versions 1.0 and
1192
                                 * 2.0 is here. For future versions of
1193
                                 * the player this may need to be modified.
1194
                                 */
1195
                                if (*(bptr + 1) == 0x02)
1196
                                   bptr += 8;
1197
                                else
1198
                                   bptr += 4;
1199
                                break;                          
1200
                                
1201
                         case 6:
1202
                                /* This is the field containing the port
1203
                                 * number that RA-player is listening to.
1204
                                 */
1205
                                lport = (((u_char*)bptr)[0] << 8) 
1206
                                + ((u_char *)bptr)[1];
1207
                                if (lport < 6970)      
1208
                                   lport += 256;   /* don't know why */
1209
                                if (lport < 6970 || lport > 7170)
1210
                                   return 1;       /* failed */
1211
                                
1212
                                /* try to get udp port between 6970 - 7170 */
1213
                                for (p = 6970; p < 7071; p++) {
1214
                                        if (udp_listen( htons(p),
1215
                                                       so->so_laddr.s_addr,
1216
                                                       htons(lport),
1217
                                                       SS_FACCEPTONCE)) {
1218
                                                break;
1219
                                        }
1220
                                }
1221
                                if (p == 7071)
1222
                                   p = 0;
1223
                                *(u_char *)bptr++ = (p >> 8) & 0xff;
1224
                                *(u_char *)bptr++ = p & 0xff;
1225
                                ra = 0; 
1226
                                return 1;   /* port redirected, we're done */
1227
                                break;  
1228
                                
1229
                         default:
1230
                                ra = 0;                         
1231
                        }
1232
                        ra++;
1233
                }
1234
                return 1;                                
1235
                
1236
         default:
1237
                /* Ooops, not emulated, won't call tcp_emu again */
1238
                so->so_emu = 0;
1239
                return 1;
1240
        }
1241
}
1242

    
1243
/*
1244
 * Do misc. config of SLiRP while its running.
1245
 * Return 0 if this connections is to be closed, 1 otherwise,
1246
 * return 2 if this is a command-line connection
1247
 */
1248
int
1249
tcp_ctl(so)
1250
        struct socket *so;
1251
{
1252
#if 0
1253
        struct sbuf *sb = &so->so_snd;
1254
        int command;
1255
         struct ex_list *ex_ptr;
1256
        int do_pty;
1257
        struct socket *tmpso;
1258
        
1259
        DEBUG_CALL("tcp_ctl");
1260
        DEBUG_ARG("so = %lx", (long )so);
1261
        
1262
        /*
1263
         * Check if they're authorised
1264
         */
1265
        if (ctl_addr.s_addr && (ctl_addr.s_addr == -1 || (so->so_laddr.s_addr != ctl_addr.s_addr))) {
1266
                sb->sb_cc = sprintf(sb->sb_wptr,"Error: Permission denied.\r\n");
1267
                sb->sb_wptr += sb->sb_cc;
1268
                return 0;
1269
        }
1270
        
1271
        command = (ntohl(so->so_faddr.s_addr) & 0xff);
1272
        
1273
        switch(command) {
1274
        default: /* Check for exec's */
1275
                
1276
                /*
1277
                 * Check if it's pty_exec
1278
                 */
1279
                for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
1280
                        if (ex_ptr->ex_fport == so->so_fport &&
1281
                            command == ex_ptr->ex_addr) {
1282
                                do_pty = ex_ptr->ex_pty;
1283
                                goto do_exec;
1284
                        }
1285
                }
1286
                
1287
                /*
1288
                 * Nothing bound..
1289
                 */
1290
                /* tcp_fconnect(so); */
1291
                
1292
                /* FALLTHROUGH */
1293
        case CTL_ALIAS:
1294
          sb->sb_cc = sprintf(sb->sb_wptr,
1295
                              "Error: No application configured.\r\n");
1296
          sb->sb_wptr += sb->sb_cc;
1297
          return(0);
1298

1299
        do_exec:
1300
                DEBUG_MISC((dfd, " executing %s \n",ex_ptr->ex_exec));
1301
                return(fork_exec(so, ex_ptr->ex_exec, do_pty));
1302
                
1303
        case CTL_CMD:
1304
           for (tmpso = tcb.so_next; tmpso != &tcb; tmpso = tmpso->so_next) {
1305
             if (tmpso->so_emu == EMU_CTL && 
1306
                 !(tmpso->so_tcpcb? 
1307
                   (tmpso->so_tcpcb->t_state & (TCPS_TIME_WAIT|TCPS_LAST_ACK))
1308
                   :0)) {
1309
               /* Ooops, control connection already active */
1310
               sb->sb_cc = sprintf(sb->sb_wptr,"Sorry, already connected.\r\n");
1311
               sb->sb_wptr += sb->sb_cc;
1312
               return 0;
1313
             }
1314
           }
1315
           so->so_emu = EMU_CTL;
1316
           ctl_password_ok = 0;
1317
           sb->sb_cc = sprintf(sb->sb_wptr, "Slirp command-line ready (type \"help\" for help).\r\nSlirp> ");
1318
           sb->sb_wptr += sb->sb_cc;
1319
           do_echo=-1;
1320
           return(2);
1321
        }
1322
#else
1323
        return 0;
1324
#endif
1325
}