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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
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 * 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
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 *    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.
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 * 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
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * 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)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 *
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 *        @(#)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 */
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#define TCP_DO_RFC1323 0
46

    
47
/*
48
 * Tcp initialization
49
 */
50
void
51
tcp_init(Slirp *slirp)
52
{
53
    slirp->tcp_iss = 1;                /* wrong */
54
    slirp->tcb.so_next = slirp->tcb.so_prev = &slirp->tcb;
55
    slirp->tcp_last_so = &slirp->tcb;
56
}
57

    
58
void tcp_cleanup(Slirp *slirp)
59
{
60
    while (slirp->tcb.so_next != &slirp->tcb) {
61
        tcp_close(sototcpcb(slirp->tcb.so_next));
62
    }
63
}
64

    
65
/*
66
 * Create template to be used to send tcp packets on a connection.
67
 * Call after host entry created, fills
68
 * in a skeletal tcp/ip header, minimizing the amount of work
69
 * necessary when the connection is used.
70
 */
71
void
72
tcp_template(struct tcpcb *tp)
73
{
74
        struct socket *so = tp->t_socket;
75
        register struct tcpiphdr *n = &tp->t_template;
76

    
77
        n->ti_mbuf = NULL;
78
        n->ti_x1 = 0;
79
        n->ti_pr = IPPROTO_TCP;
80
        n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip));
81
        n->ti_src = so->so_faddr;
82
        n->ti_dst = so->so_laddr;
83
        n->ti_sport = so->so_fport;
84
        n->ti_dport = so->so_lport;
85

    
86
        n->ti_seq = 0;
87
        n->ti_ack = 0;
88
        n->ti_x2 = 0;
89
        n->ti_off = 5;
90
        n->ti_flags = 0;
91
        n->ti_win = 0;
92
        n->ti_sum = 0;
93
        n->ti_urp = 0;
94
}
95

    
96
/*
97
 * Send a single message to the TCP at address specified by
98
 * the given TCP/IP header.  If m == 0, then we make a copy
99
 * of the tcpiphdr at ti and send directly to the addressed host.
100
 * This is used to force keep alive messages out using the TCP
101
 * template for a connection tp->t_template.  If flags are given
102
 * then we send a message back to the TCP which originated the
103
 * segment ti, and discard the mbuf containing it and any other
104
 * attached mbufs.
105
 *
106
 * In any case the ack and sequence number of the transmitted
107
 * segment are as specified by the parameters.
108
 */
109
void
110
tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
111
            tcp_seq ack, tcp_seq seq, int flags)
112
{
113
        register int tlen;
114
        int win = 0;
115

    
116
        DEBUG_CALL("tcp_respond");
117
        DEBUG_ARG("tp = %p", tp);
118
        DEBUG_ARG("ti = %p", ti);
119
        DEBUG_ARG("m = %p", m);
120
        DEBUG_ARG("ack = %u", ack);
121
        DEBUG_ARG("seq = %u", seq);
122
        DEBUG_ARG("flags = %x", flags);
123

    
124
        if (tp)
125
                win = sbspace(&tp->t_socket->so_rcv);
126
        if (m == NULL) {
127
                if ((m = m_get(tp->t_socket->slirp)) == NULL)
128
                        return;
129
                tlen = 0;
130
                m->m_data += IF_MAXLINKHDR;
131
                *mtod(m, struct tcpiphdr *) = *ti;
132
                ti = mtod(m, struct tcpiphdr *);
133
                flags = TH_ACK;
134
        } else {
135
                /*
136
                 * ti points into m so the next line is just making
137
                 * the mbuf point to ti
138
                 */
139
                m->m_data = (caddr_t)ti;
140

    
141
                m->m_len = sizeof (struct tcpiphdr);
142
                tlen = 0;
143
#define xchg(a,b,type) { type t; t=a; a=b; b=t; }
144
                xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, uint32_t);
145
                xchg(ti->ti_dport, ti->ti_sport, uint16_t);
146
#undef xchg
147
        }
148
        ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen));
149
        tlen += sizeof (struct tcpiphdr);
150
        m->m_len = tlen;
151

    
152
        ti->ti_mbuf = NULL;
153
        ti->ti_x1 = 0;
154
        ti->ti_seq = htonl(seq);
155
        ti->ti_ack = htonl(ack);
156
        ti->ti_x2 = 0;
157
        ti->ti_off = sizeof (struct tcphdr) >> 2;
158
        ti->ti_flags = flags;
159
        if (tp)
160
                ti->ti_win = htons((uint16_t) (win >> tp->rcv_scale));
161
        else
162
                ti->ti_win = htons((uint16_t)win);
163
        ti->ti_urp = 0;
164
        ti->ti_sum = 0;
165
        ti->ti_sum = cksum(m, tlen);
166
        ((struct ip *)ti)->ip_len = tlen;
167

    
168
        if(flags & TH_RST)
169
          ((struct ip *)ti)->ip_ttl = MAXTTL;
170
        else
171
          ((struct ip *)ti)->ip_ttl = IPDEFTTL;
172

    
173
        (void) ip_output((struct socket *)0, m);
174
}
175

    
176
/*
177
 * Create a new TCP control block, making an
178
 * empty reassembly queue and hooking it to the argument
179
 * protocol control block.
180
 */
181
struct tcpcb *
182
tcp_newtcpcb(struct socket *so)
183
{
184
        register struct tcpcb *tp;
185

    
186
        tp = (struct tcpcb *)malloc(sizeof(*tp));
187
        if (tp == NULL)
188
                return ((struct tcpcb *)0);
189

    
190
        memset((char *) tp, 0, sizeof(struct tcpcb));
191
        tp->seg_next = tp->seg_prev = (struct tcpiphdr*)tp;
192
        tp->t_maxseg = TCP_MSS;
193

    
194
        tp->t_flags = TCP_DO_RFC1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0;
195
        tp->t_socket = so;
196

    
197
        /*
198
         * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
199
         * rtt estimate.  Set rttvar so that srtt + 2 * rttvar gives
200
         * reasonable initial retransmit time.
201
         */
202
        tp->t_srtt = TCPTV_SRTTBASE;
203
        tp->t_rttvar = TCPTV_SRTTDFLT << 2;
204
        tp->t_rttmin = TCPTV_MIN;
205

    
206
        TCPT_RANGESET(tp->t_rxtcur,
207
            ((TCPTV_SRTTBASE >> 2) + (TCPTV_SRTTDFLT << 2)) >> 1,
208
            TCPTV_MIN, TCPTV_REXMTMAX);
209

    
210
        tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
211
        tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
212
        tp->t_state = TCPS_CLOSED;
213

    
214
        so->so_tcpcb = tp;
215

    
216
        return (tp);
217
}
218

    
219
/*
220
 * Drop a TCP connection, reporting
221
 * the specified error.  If connection is synchronized,
222
 * then send a RST to peer.
223
 */
224
struct tcpcb *tcp_drop(struct tcpcb *tp, int err)
225
{
226
        DEBUG_CALL("tcp_drop");
227
        DEBUG_ARG("tp = %lx", (long)tp);
228
        DEBUG_ARG("errno = %d", errno);
229

    
230
        if (TCPS_HAVERCVDSYN(tp->t_state)) {
231
                tp->t_state = TCPS_CLOSED;
232
                (void) tcp_output(tp);
233
        }
234
        return (tcp_close(tp));
235
}
236

    
237
/*
238
 * Close a TCP control block:
239
 *        discard all space held by the tcp
240
 *        discard internet protocol block
241
 *        wake up any sleepers
242
 */
243
struct tcpcb *
244
tcp_close(struct tcpcb *tp)
245
{
246
        register struct tcpiphdr *t;
247
        struct socket *so = tp->t_socket;
248
        Slirp *slirp = so->slirp;
249
        register struct mbuf *m;
250

    
251
        DEBUG_CALL("tcp_close");
252
        DEBUG_ARG("tp = %lx", (long )tp);
253

    
254
        /* free the reassembly queue, if any */
255
        t = tcpfrag_list_first(tp);
256
        while (!tcpfrag_list_end(t, tp)) {
257
                t = tcpiphdr_next(t);
258
                m = tcpiphdr_prev(t)->ti_mbuf;
259
                remque(tcpiphdr2qlink(tcpiphdr_prev(t)));
260
                m_free(m);
261
        }
262
        free(tp);
263
        so->so_tcpcb = NULL;
264
        /* clobber input socket cache if we're closing the cached connection */
265
        if (so == slirp->tcp_last_so)
266
                slirp->tcp_last_so = &slirp->tcb;
267
        closesocket(so->s);
268
        sbfree(&so->so_rcv);
269
        sbfree(&so->so_snd);
270
        sofree(so);
271
        return ((struct tcpcb *)0);
272
}
273

    
274
/*
275
 * TCP protocol interface to socket abstraction.
276
 */
277

    
278
/*
279
 * User issued close, and wish to trail through shutdown states:
280
 * if never received SYN, just forget it.  If got a SYN from peer,
281
 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
282
 * If already got a FIN from peer, then almost done; go to LAST_ACK
283
 * state.  In all other cases, have already sent FIN to peer (e.g.
284
 * after PRU_SHUTDOWN), and just have to play tedious game waiting
285
 * for peer to send FIN or not respond to keep-alives, etc.
286
 * We can let the user exit from the close as soon as the FIN is acked.
287
 */
288
void
289
tcp_sockclosed(struct tcpcb *tp)
290
{
291

    
292
        DEBUG_CALL("tcp_sockclosed");
293
        DEBUG_ARG("tp = %lx", (long)tp);
294

    
295
        switch (tp->t_state) {
296

    
297
        case TCPS_CLOSED:
298
        case TCPS_LISTEN:
299
        case TCPS_SYN_SENT:
300
                tp->t_state = TCPS_CLOSED;
301
                tp = tcp_close(tp);
302
                break;
303

    
304
        case TCPS_SYN_RECEIVED:
305
        case TCPS_ESTABLISHED:
306
                tp->t_state = TCPS_FIN_WAIT_1;
307
                break;
308

    
309
        case TCPS_CLOSE_WAIT:
310
                tp->t_state = TCPS_LAST_ACK;
311
                break;
312
        }
313
        if (tp)
314
                tcp_output(tp);
315
}
316

    
317
/*
318
 * Connect to a host on the Internet
319
 * Called by tcp_input
320
 * Only do a connect, the tcp fields will be set in tcp_input
321
 * return 0 if there's a result of the connect,
322
 * else return -1 means we're still connecting
323
 * The return value is almost always -1 since the socket is
324
 * nonblocking.  Connect returns after the SYN is sent, and does
325
 * not wait for ACK+SYN.
326
 */
327
int tcp_fconnect(struct socket *so)
328
{
329
  Slirp *slirp = so->slirp;
330
  int ret=0;
331

    
332
  DEBUG_CALL("tcp_fconnect");
333
  DEBUG_ARG("so = %lx", (long )so);
334

    
335
  if( (ret = so->s = qemu_socket(AF_INET,SOCK_STREAM,0)) >= 0) {
336
    int opt, s=so->s;
337
    struct sockaddr_in addr;
338

    
339
    socket_set_nonblock(s);
340
    opt = 1;
341
    setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(opt ));
342
    opt = 1;
343
    setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(opt ));
344

    
345
    addr.sin_family = AF_INET;
346
    if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
347
        slirp->vnetwork_addr.s_addr) {
348
      /* It's an alias */
349
      if (so->so_faddr.s_addr == slirp->vnameserver_addr.s_addr) {
350
        if (get_dns_addr(&addr.sin_addr) < 0)
351
          addr.sin_addr = loopback_addr;
352
      } else {
353
        addr.sin_addr = loopback_addr;
354
      }
355
    } else
356
      addr.sin_addr = so->so_faddr;
357
    addr.sin_port = so->so_fport;
358

    
359
    DEBUG_MISC((dfd, " connect()ing, addr.sin_port=%d, "
360
                "addr.sin_addr.s_addr=%.16s\n",
361
                ntohs(addr.sin_port), inet_ntoa(addr.sin_addr)));
362
    /* We don't care what port we get */
363
    ret = connect(s,(struct sockaddr *)&addr,sizeof (addr));
364

    
365
    /*
366
     * If it's not in progress, it failed, so we just return 0,
367
     * without clearing SS_NOFDREF
368
     */
369
    soisfconnecting(so);
370
  }
371

    
372
  return(ret);
373
}
374

    
375
/*
376
 * Accept the socket and connect to the local-host
377
 *
378
 * We have a problem. The correct thing to do would be
379
 * to first connect to the local-host, and only if the
380
 * connection is accepted, then do an accept() here.
381
 * But, a) we need to know who's trying to connect
382
 * to the socket to be able to SYN the local-host, and
383
 * b) we are already connected to the foreign host by
384
 * the time it gets to accept(), so... We simply accept
385
 * here and SYN the local-host.
386
 */
387
void
388
tcp_connect(struct socket *inso)
389
{
390
        Slirp *slirp = inso->slirp;
391
        struct socket *so;
392
        struct sockaddr_in addr;
393
        socklen_t addrlen = sizeof(struct sockaddr_in);
394
        struct tcpcb *tp;
395
        int s, opt;
396

    
397
        DEBUG_CALL("tcp_connect");
398
        DEBUG_ARG("inso = %lx", (long)inso);
399

    
400
        /*
401
         * If it's an SS_ACCEPTONCE socket, no need to socreate()
402
         * another socket, just use the accept() socket.
403
         */
404
        if (inso->so_state & SS_FACCEPTONCE) {
405
                /* FACCEPTONCE already have a tcpcb */
406
                so = inso;
407
        } else {
408
                if ((so = socreate(slirp)) == NULL) {
409
                        /* If it failed, get rid of the pending connection */
410
                        closesocket(accept(inso->s,(struct sockaddr *)&addr,&addrlen));
411
                        return;
412
                }
413
                if (tcp_attach(so) < 0) {
414
                        free(so); /* NOT sofree */
415
                        return;
416
                }
417
                so->so_laddr = inso->so_laddr;
418
                so->so_lport = inso->so_lport;
419
        }
420

    
421
        (void) tcp_mss(sototcpcb(so), 0);
422

    
423
        if ((s = accept(inso->s,(struct sockaddr *)&addr,&addrlen)) < 0) {
424
                tcp_close(sototcpcb(so)); /* This will sofree() as well */
425
                return;
426
        }
427
        socket_set_nonblock(s);
428
        opt = 1;
429
        setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
430
        opt = 1;
431
        setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
432
        opt = 1;
433
        setsockopt(s,IPPROTO_TCP,TCP_NODELAY,(char *)&opt,sizeof(int));
434

    
435
        so->so_fport = addr.sin_port;
436
        so->so_faddr = addr.sin_addr;
437
        /* Translate connections from localhost to the real hostname */
438
        if (so->so_faddr.s_addr == 0 ||
439
            (so->so_faddr.s_addr & loopback_mask) ==
440
            (loopback_addr.s_addr & loopback_mask)) {
441
            so->so_faddr = slirp->vhost_addr;
442
        }
443

    
444
        /* Close the accept() socket, set right state */
445
        if (inso->so_state & SS_FACCEPTONCE) {
446
                closesocket(so->s); /* If we only accept once, close the accept() socket */
447
                so->so_state = SS_NOFDREF; /* Don't select it yet, even though we have an FD */
448
                                           /* if it's not FACCEPTONCE, it's already NOFDREF */
449
        }
450
        so->s = s;
451
        so->so_state |= SS_INCOMING;
452

    
453
        so->so_iptos = tcp_tos(so);
454
        tp = sototcpcb(so);
455

    
456
        tcp_template(tp);
457

    
458
        tp->t_state = TCPS_SYN_SENT;
459
        tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
460
        tp->iss = slirp->tcp_iss;
461
        slirp->tcp_iss += TCP_ISSINCR/2;
462
        tcp_sendseqinit(tp);
463
        tcp_output(tp);
464
}
465

    
466
/*
467
 * Attach a TCPCB to a socket.
468
 */
469
int
470
tcp_attach(struct socket *so)
471
{
472
        if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
473
           return -1;
474

    
475
        insque(so, &so->slirp->tcb);
476

    
477
        return 0;
478
}
479

    
480
/*
481
 * Set the socket's type of service field
482
 */
483
static const struct tos_t tcptos[] = {
484
          {0, 20, IPTOS_THROUGHPUT, 0},        /* ftp data */
485
          {21, 21, IPTOS_LOWDELAY,  EMU_FTP},        /* ftp control */
486
          {0, 23, IPTOS_LOWDELAY, 0},        /* telnet */
487
          {0, 80, IPTOS_THROUGHPUT, 0},        /* WWW */
488
          {0, 513, IPTOS_LOWDELAY, EMU_RLOGIN|EMU_NOCONNECT},        /* rlogin */
489
          {0, 514, IPTOS_LOWDELAY, EMU_RSH|EMU_NOCONNECT},        /* shell */
490
          {0, 544, IPTOS_LOWDELAY, EMU_KSH},                /* kshell */
491
          {0, 543, IPTOS_LOWDELAY, 0},        /* klogin */
492
          {0, 6667, IPTOS_THROUGHPUT, EMU_IRC},        /* IRC */
493
          {0, 6668, IPTOS_THROUGHPUT, EMU_IRC},        /* IRC undernet */
494
          {0, 7070, IPTOS_LOWDELAY, EMU_REALAUDIO }, /* RealAudio control */
495
          {0, 113, IPTOS_LOWDELAY, EMU_IDENT }, /* identd protocol */
496
          {0, 0, 0, 0}
497
};
498

    
499
static struct emu_t *tcpemu = NULL;
500

    
501
/*
502
 * Return TOS according to the above table
503
 */
504
uint8_t
505
tcp_tos(struct socket *so)
506
{
507
        int i = 0;
508
        struct emu_t *emup;
509

    
510
        while(tcptos[i].tos) {
511
                if ((tcptos[i].fport && (ntohs(so->so_fport) == tcptos[i].fport)) ||
512
                    (tcptos[i].lport && (ntohs(so->so_lport) == tcptos[i].lport))) {
513
                        so->so_emu = tcptos[i].emu;
514
                        return tcptos[i].tos;
515
                }
516
                i++;
517
        }
518

    
519
        /* Nope, lets see if there's a user-added one */
520
        for (emup = tcpemu; emup; emup = emup->next) {
521
                if ((emup->fport && (ntohs(so->so_fport) == emup->fport)) ||
522
                    (emup->lport && (ntohs(so->so_lport) == emup->lport))) {
523
                        so->so_emu = emup->emu;
524
                        return emup->tos;
525
                }
526
        }
527

    
528
        return 0;
529
}
530

    
531
/*
532
 * Emulate programs that try and connect to us
533
 * This includes ftp (the data connection is
534
 * initiated by the server) and IRC (DCC CHAT and
535
 * DCC SEND) for now
536
 *
537
 * NOTE: It's possible to crash SLiRP by sending it
538
 * unstandard strings to emulate... if this is a problem,
539
 * more checks are needed here
540
 *
541
 * XXX Assumes the whole command came in one packet
542
 *
543
 * XXX Some ftp clients will have their TOS set to
544
 * LOWDELAY and so Nagel will kick in.  Because of this,
545
 * we'll get the first letter, followed by the rest, so
546
 * we simply scan for ORT instead of PORT...
547
 * DCC doesn't have this problem because there's other stuff
548
 * in the packet before the DCC command.
549
 *
550
 * Return 1 if the mbuf m is still valid and should be
551
 * sbappend()ed
552
 *
553
 * NOTE: if you return 0 you MUST m_free() the mbuf!
554
 */
555
int
556
tcp_emu(struct socket *so, struct mbuf *m)
557
{
558
        Slirp *slirp = so->slirp;
559
        u_int n1, n2, n3, n4, n5, n6;
560
        char buff[257];
561
        uint32_t laddr;
562
        u_int lport;
563
        char *bptr;
564

    
565
        DEBUG_CALL("tcp_emu");
566
        DEBUG_ARG("so = %lx", (long)so);
567
        DEBUG_ARG("m = %lx", (long)m);
568

    
569
        switch(so->so_emu) {
570
                int x, i;
571

    
572
         case EMU_IDENT:
573
                /*
574
                 * Identification protocol as per rfc-1413
575
                 */
576

    
577
                {
578
                        struct socket *tmpso;
579
                        struct sockaddr_in addr;
580
                        socklen_t addrlen = sizeof(struct sockaddr_in);
581
                        struct sbuf *so_rcv = &so->so_rcv;
582

    
583
                        memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
584
                        so_rcv->sb_wptr += m->m_len;
585
                        so_rcv->sb_rptr += m->m_len;
586
                        m->m_data[m->m_len] = 0; /* NULL terminate */
587
                        if (strchr(m->m_data, '\r') || strchr(m->m_data, '\n')) {
588
                                if (sscanf(so_rcv->sb_data, "%u%*[ ,]%u", &n1, &n2) == 2) {
589
                                        HTONS(n1);
590
                                        HTONS(n2);
591
                                        /* n2 is the one on our host */
592
                                        for (tmpso = slirp->tcb.so_next;
593
                                             tmpso != &slirp->tcb;
594
                                             tmpso = tmpso->so_next) {
595
                                                if (tmpso->so_laddr.s_addr == so->so_laddr.s_addr &&
596
                                                    tmpso->so_lport == n2 &&
597
                                                    tmpso->so_faddr.s_addr == so->so_faddr.s_addr &&
598
                                                    tmpso->so_fport == n1) {
599
                                                        if (getsockname(tmpso->s,
600
                                                                (struct sockaddr *)&addr, &addrlen) == 0)
601
                                                           n2 = ntohs(addr.sin_port);
602
                                                        break;
603
                                                }
604
                                        }
605
                                }
606
                                so_rcv->sb_cc = snprintf(so_rcv->sb_data,
607
                                                         so_rcv->sb_datalen,
608
                                                         "%d,%d\r\n", n1, n2);
609
                                so_rcv->sb_rptr = so_rcv->sb_data;
610
                                so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
611
                        }
612
                        m_free(m);
613
                        return 0;
614
                }
615

    
616
        case EMU_FTP: /* ftp */
617
                *(m->m_data+m->m_len) = 0; /* NUL terminate for strstr */
618
                if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
619
                        /*
620
                         * Need to emulate the PORT command
621
                         */
622
                        x = sscanf(bptr, "ORT %u,%u,%u,%u,%u,%u\r\n%256[^\177]",
623
                                   &n1, &n2, &n3, &n4, &n5, &n6, buff);
624
                        if (x < 6)
625
                           return 1;
626

    
627
                        laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
628
                        lport = htons((n5 << 8) | (n6));
629

    
630
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
631
                                             lport, SS_FACCEPTONCE)) == NULL) {
632
                           return 1;
633
                        }
634
                        n6 = ntohs(so->so_fport);
635

    
636
                        n5 = (n6 >> 8) & 0xff;
637
                        n6 &= 0xff;
638

    
639
                        laddr = ntohl(so->so_faddr.s_addr);
640

    
641
                        n1 = ((laddr >> 24) & 0xff);
642
                        n2 = ((laddr >> 16) & 0xff);
643
                        n3 = ((laddr >> 8)  & 0xff);
644
                        n4 =  (laddr & 0xff);
645

    
646
                        m->m_len = bptr - m->m_data; /* Adjust length */
647
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
648
                                             "ORT %d,%d,%d,%d,%d,%d\r\n%s",
649
                                             n1, n2, n3, n4, n5, n6, x==7?buff:"");
650
                        return 1;
651
                } else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
652
                        /*
653
                         * Need to emulate the PASV response
654
                         */
655
                        x = sscanf(bptr, "27 Entering Passive Mode (%u,%u,%u,%u,%u,%u)\r\n%256[^\177]",
656
                                   &n1, &n2, &n3, &n4, &n5, &n6, buff);
657
                        if (x < 6)
658
                           return 1;
659

    
660
                        laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
661
                        lport = htons((n5 << 8) | (n6));
662

    
663
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
664
                                             lport, SS_FACCEPTONCE)) == NULL) {
665
                           return 1;
666
                        }
667
                        n6 = ntohs(so->so_fport);
668

    
669
                        n5 = (n6 >> 8) & 0xff;
670
                        n6 &= 0xff;
671

    
672
                        laddr = ntohl(so->so_faddr.s_addr);
673

    
674
                        n1 = ((laddr >> 24) & 0xff);
675
                        n2 = ((laddr >> 16) & 0xff);
676
                        n3 = ((laddr >> 8)  & 0xff);
677
                        n4 =  (laddr & 0xff);
678

    
679
                        m->m_len = bptr - m->m_data; /* Adjust length */
680
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
681
                                             "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
682
                                             n1, n2, n3, n4, n5, n6, x==7?buff:"");
683

    
684
                        return 1;
685
                }
686

    
687
                return 1;
688

    
689
         case EMU_KSH:
690
                /*
691
                 * The kshell (Kerberos rsh) and shell services both pass
692
                 * a local port port number to carry signals to the server
693
                 * and stderr to the client.  It is passed at the beginning
694
                 * of the connection as a NUL-terminated decimal ASCII string.
695
                 */
696
                so->so_emu = 0;
697
                for (lport = 0, i = 0; i < m->m_len-1; ++i) {
698
                        if (m->m_data[i] < '0' || m->m_data[i] > '9')
699
                                return 1;       /* invalid number */
700
                        lport *= 10;
701
                        lport += m->m_data[i] - '0';
702
                }
703
                if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
704
                    (so = tcp_listen(slirp, INADDR_ANY, 0, so->so_laddr.s_addr,
705
                                     htons(lport), SS_FACCEPTONCE)) != NULL)
706
                    m->m_len = snprintf(m->m_data, m->m_hdr.mh_size, "%d",
707
                                        ntohs(so->so_fport)) + 1;
708
                return 1;
709

    
710
         case EMU_IRC:
711
                /*
712
                 * Need to emulate DCC CHAT, DCC SEND and DCC MOVE
713
                 */
714
                *(m->m_data+m->m_len) = 0; /* NULL terminate the string for strstr */
715
                if ((bptr = (char *)strstr(m->m_data, "DCC")) == NULL)
716
                         return 1;
717

    
718
                /* The %256s is for the broken mIRC */
719
                if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) {
720
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0,
721
                                             htonl(laddr), htons(lport),
722
                                             SS_FACCEPTONCE)) == NULL) {
723
                                return 1;
724
                        }
725
                        m->m_len = bptr - m->m_data; /* Adjust length */
726
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
727
                                             "DCC CHAT chat %lu %u%c\n",
728
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
729
                                             ntohs(so->so_fport), 1);
730
                } else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
731
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0,
732
                                             htonl(laddr), htons(lport),
733
                                             SS_FACCEPTONCE)) == NULL) {
734
                                return 1;
735
                        }
736
                        m->m_len = bptr - m->m_data; /* Adjust length */
737
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
738
                                             "DCC SEND %s %lu %u %u%c\n", buff,
739
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
740
                                             ntohs(so->so_fport), n1, 1);
741
                } else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
742
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0,
743
                                             htonl(laddr), htons(lport),
744
                                             SS_FACCEPTONCE)) == NULL) {
745
                                return 1;
746
                        }
747
                        m->m_len = bptr - m->m_data; /* Adjust length */
748
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
749
                                             "DCC MOVE %s %lu %u %u%c\n", buff,
750
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
751
                                             ntohs(so->so_fport), n1, 1);
752
                }
753
                return 1;
754

    
755
         case EMU_REALAUDIO:
756
                /*
757
                 * RealAudio emulation - JP. We must try to parse the incoming
758
                 * data and try to find the two characters that contain the
759
                 * port number. Then we redirect an udp port and replace the
760
                 * number with the real port we got.
761
                 *
762
                 * The 1.0 beta versions of the player are not supported
763
                 * any more.
764
                 *
765
                 * A typical packet for player version 1.0 (release version):
766
                 *
767
                 * 0000:50 4E 41 00 05
768
                 * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 ........g.l.c..P
769
                 * 0010:4E 43 4C 49 45 4E 54 20 31 30 31 20 41 4C 50 48 NCLIENT 101 ALPH
770
                 * 0020:41 6C 00 00 52 00 17 72 61 66 69 6C 65 73 2F 76 Al..R..rafiles/v
771
                 * 0030:6F 61 2F 65 6E 67 6C 69 73 68 5F 2E 72 61 79 42 oa/english_.rayB
772
                 *
773
                 * Now the port number 0x1BD7 is found at offset 0x04 of the
774
                 * Now the port number 0x1BD7 is found at offset 0x04 of the
775
                 * second packet. This time we received five bytes first and
776
                 * then the rest. You never know how many bytes you get.
777
                 *
778
                 * A typical packet for player version 2.0 (beta):
779
                 *
780
                 * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA.............
781
                 * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .gux.c..Win2.0.0
782
                 * 0020:2E 35 6C 00 00 52 00 1C 72 61 66 69 6C 65 73 2F .5l..R..rafiles/
783
                 * 0030:77 65 62 73 69 74 65 2F 32 30 72 65 6C 65 61 73 website/20releas
784
                 * 0040:65 2E 72 61 79 53 00 00 06 36 42                e.rayS...6B
785
                 *
786
                 * Port number 0x1BC1 is found at offset 0x0d.
787
                 *
788
                 * This is just a horrible switch statement. Variable ra tells
789
                 * us where we're going.
790
                 */
791

    
792
                bptr = m->m_data;
793
                while (bptr < m->m_data + m->m_len) {
794
                        u_short p;
795
                        static int ra = 0;
796
                        char ra_tbl[4];
797

    
798
                        ra_tbl[0] = 0x50;
799
                        ra_tbl[1] = 0x4e;
800
                        ra_tbl[2] = 0x41;
801
                        ra_tbl[3] = 0;
802

    
803
                        switch (ra) {
804
                         case 0:
805
                         case 2:
806
                         case 3:
807
                                if (*bptr++ != ra_tbl[ra]) {
808
                                        ra = 0;
809
                                        continue;
810
                                }
811
                                break;
812

    
813
                         case 1:
814
                                /*
815
                                 * We may get 0x50 several times, ignore them
816
                                 */
817
                                if (*bptr == 0x50) {
818
                                        ra = 1;
819
                                        bptr++;
820
                                        continue;
821
                                } else if (*bptr++ != ra_tbl[ra]) {
822
                                        ra = 0;
823
                                        continue;
824
                                }
825
                                break;
826

    
827
                         case 4:
828
                                /*
829
                                 * skip version number
830
                                 */
831
                                bptr++;
832
                                break;
833

    
834
                         case 5:
835
                                /*
836
                                 * The difference between versions 1.0 and
837
                                 * 2.0 is here. For future versions of
838
                                 * the player this may need to be modified.
839
                                 */
840
                                if (*(bptr + 1) == 0x02)
841
                                   bptr += 8;
842
                                else
843
                                   bptr += 4;
844
                                break;
845

    
846
                         case 6:
847
                                /* This is the field containing the port
848
                                 * number that RA-player is listening to.
849
                                 */
850
                                lport = (((u_char*)bptr)[0] << 8)
851
                                + ((u_char *)bptr)[1];
852
                                if (lport < 6970)
853
                                   lport += 256;   /* don't know why */
854
                                if (lport < 6970 || lport > 7170)
855
                                   return 1;       /* failed */
856

    
857
                                /* try to get udp port between 6970 - 7170 */
858
                                for (p = 6970; p < 7071; p++) {
859
                                        if (udp_listen(slirp, INADDR_ANY,
860
                                                       htons(p),
861
                                                       so->so_laddr.s_addr,
862
                                                       htons(lport),
863
                                                       SS_FACCEPTONCE)) {
864
                                                break;
865
                                        }
866
                                }
867
                                if (p == 7071)
868
                                   p = 0;
869
                                *(u_char *)bptr++ = (p >> 8) & 0xff;
870
                                *(u_char *)bptr = p & 0xff;
871
                                ra = 0;
872
                                return 1;   /* port redirected, we're done */
873
                                break;
874

    
875
                         default:
876
                                ra = 0;
877
                        }
878
                        ra++;
879
                }
880
                return 1;
881

    
882
         default:
883
                /* Ooops, not emulated, won't call tcp_emu again */
884
                so->so_emu = 0;
885
                return 1;
886
        }
887
}
888

    
889
/*
890
 * Do misc. config of SLiRP while its running.
891
 * Return 0 if this connections is to be closed, 1 otherwise,
892
 * return 2 if this is a command-line connection
893
 */
894
int tcp_ctl(struct socket *so)
895
{
896
    Slirp *slirp = so->slirp;
897
    struct sbuf *sb = &so->so_snd;
898
    struct ex_list *ex_ptr;
899
    int do_pty;
900

    
901
    DEBUG_CALL("tcp_ctl");
902
    DEBUG_ARG("so = %lx", (long )so);
903

    
904
    if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr) {
905
        /* Check if it's pty_exec */
906
        for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
907
            if (ex_ptr->ex_fport == so->so_fport &&
908
                so->so_faddr.s_addr == ex_ptr->ex_addr.s_addr) {
909
                if (ex_ptr->ex_pty == 3) {
910
                    so->s = -1;
911
                    so->extra = (void *)ex_ptr->ex_exec;
912
                    return 1;
913
                }
914
                do_pty = ex_ptr->ex_pty;
915
                DEBUG_MISC((dfd, " executing %s\n", ex_ptr->ex_exec));
916
                return fork_exec(so, ex_ptr->ex_exec, do_pty);
917
            }
918
        }
919
    }
920
    sb->sb_cc =
921
        snprintf(sb->sb_wptr, sb->sb_datalen - (sb->sb_wptr - sb->sb_data),
922
                 "Error: No application configured.\r\n");
923
    sb->sb_wptr += sb->sb_cc;
924
    return 0;
925
}