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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:
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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.
13
 * 3. Neither the name of the University nor the names of its contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19
 * 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.
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 *
37
 * Please read the file COPYRIGHT for the
38
 * terms and conditions of the copyright.
39
 */
40

    
41
#include <slirp.h>
42

    
43
/* patchable/settable parameters for tcp */
44
/* Don't do rfc1323 performance enhancements */
45
#define TCP_DO_RFC1323 0
46

    
47
/*
48
 * Tcp initialization
49
 */
50
void
51
tcp_init(Slirp *slirp)
52
{
53
    slirp->tcp_iss = 1;                /* wrong */
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    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 (!tp || (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 tcp_connect(struct socket *inso)
388
{
389
    Slirp *slirp = inso->slirp;
390
    struct socket *so;
391
    struct sockaddr_in addr;
392
    socklen_t addrlen = sizeof(struct sockaddr_in);
393
    struct tcpcb *tp;
394
    int s, opt;
395

    
396
    DEBUG_CALL("tcp_connect");
397
    DEBUG_ARG("inso = %lx", (long)inso);
398

    
399
    /*
400
     * If it's an SS_ACCEPTONCE socket, no need to socreate()
401
     * another socket, just use the accept() socket.
402
     */
403
    if (inso->so_state & SS_FACCEPTONCE) {
404
        /* FACCEPTONCE already have a tcpcb */
405
        so = inso;
406
    } else {
407
        so = socreate(slirp);
408
        if (so == 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
    tcp_mss(sototcpcb(so), 0);
422

    
423
    s = accept(inso->s, (struct sockaddr *)&addr, &addrlen);
424
    if (s < 0) {
425
        tcp_close(sototcpcb(so)); /* This will sofree() as well */
426
        return;
427
    }
428
    socket_set_nonblock(s);
429
    opt = 1;
430
    setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&opt, sizeof(int));
431
    opt = 1;
432
    setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (char *)&opt, sizeof(int));
433
    opt = 1;
434
    setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (char *)&opt, sizeof(int));
435

    
436
    so->so_fport = addr.sin_port;
437
    so->so_faddr = addr.sin_addr;
438
    /* Translate connections from localhost to the real hostname */
439
    if (so->so_faddr.s_addr == 0 ||
440
        (so->so_faddr.s_addr & loopback_mask) ==
441
        (loopback_addr.s_addr & loopback_mask)) {
442
        so->so_faddr = slirp->vhost_addr;
443
    }
444

    
445
    /* Close the accept() socket, set right state */
446
    if (inso->so_state & SS_FACCEPTONCE) {
447
        /* If we only accept once, close the accept() socket */
448
        closesocket(so->s);
449

    
450
        /* Don't select it yet, even though we have an FD */
451
        /* if it's not FACCEPTONCE, it's already NOFDREF */
452
        so->so_state = SS_NOFDREF;
453
    }
454
    so->s = s;
455
    so->so_state |= SS_INCOMING;
456

    
457
    so->so_iptos = tcp_tos(so);
458
    tp = sototcpcb(so);
459

    
460
    tcp_template(tp);
461

    
462
    tp->t_state = TCPS_SYN_SENT;
463
    tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
464
    tp->iss = slirp->tcp_iss;
465
    slirp->tcp_iss += TCP_ISSINCR/2;
466
    tcp_sendseqinit(tp);
467
    tcp_output(tp);
468
}
469

    
470
/*
471
 * Attach a TCPCB to a socket.
472
 */
473
int
474
tcp_attach(struct socket *so)
475
{
476
        if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
477
           return -1;
478

    
479
        insque(so, &so->slirp->tcb);
480

    
481
        return 0;
482
}
483

    
484
/*
485
 * Set the socket's type of service field
486
 */
487
static const struct tos_t tcptos[] = {
488
          {0, 20, IPTOS_THROUGHPUT, 0},        /* ftp data */
489
          {21, 21, IPTOS_LOWDELAY,  EMU_FTP},        /* ftp control */
490
          {0, 23, IPTOS_LOWDELAY, 0},        /* telnet */
491
          {0, 80, IPTOS_THROUGHPUT, 0},        /* WWW */
492
          {0, 513, IPTOS_LOWDELAY, EMU_RLOGIN|EMU_NOCONNECT},        /* rlogin */
493
          {0, 514, IPTOS_LOWDELAY, EMU_RSH|EMU_NOCONNECT},        /* shell */
494
          {0, 544, IPTOS_LOWDELAY, EMU_KSH},                /* kshell */
495
          {0, 543, IPTOS_LOWDELAY, 0},        /* klogin */
496
          {0, 6667, IPTOS_THROUGHPUT, EMU_IRC},        /* IRC */
497
          {0, 6668, IPTOS_THROUGHPUT, EMU_IRC},        /* IRC undernet */
498
          {0, 7070, IPTOS_LOWDELAY, EMU_REALAUDIO }, /* RealAudio control */
499
          {0, 113, IPTOS_LOWDELAY, EMU_IDENT }, /* identd protocol */
500
          {0, 0, 0, 0}
501
};
502

    
503
static struct emu_t *tcpemu = NULL;
504

    
505
/*
506
 * Return TOS according to the above table
507
 */
508
uint8_t
509
tcp_tos(struct socket *so)
510
{
511
        int i = 0;
512
        struct emu_t *emup;
513

    
514
        while(tcptos[i].tos) {
515
                if ((tcptos[i].fport && (ntohs(so->so_fport) == tcptos[i].fport)) ||
516
                    (tcptos[i].lport && (ntohs(so->so_lport) == tcptos[i].lport))) {
517
                        so->so_emu = tcptos[i].emu;
518
                        return tcptos[i].tos;
519
                }
520
                i++;
521
        }
522

    
523
        /* Nope, lets see if there's a user-added one */
524
        for (emup = tcpemu; emup; emup = emup->next) {
525
                if ((emup->fport && (ntohs(so->so_fport) == emup->fport)) ||
526
                    (emup->lport && (ntohs(so->so_lport) == emup->lport))) {
527
                        so->so_emu = emup->emu;
528
                        return emup->tos;
529
                }
530
        }
531

    
532
        return 0;
533
}
534

    
535
/*
536
 * Emulate programs that try and connect to us
537
 * This includes ftp (the data connection is
538
 * initiated by the server) and IRC (DCC CHAT and
539
 * DCC SEND) for now
540
 *
541
 * NOTE: It's possible to crash SLiRP by sending it
542
 * unstandard strings to emulate... if this is a problem,
543
 * more checks are needed here
544
 *
545
 * XXX Assumes the whole command came in one packet
546
 *
547
 * XXX Some ftp clients will have their TOS set to
548
 * LOWDELAY and so Nagel will kick in.  Because of this,
549
 * we'll get the first letter, followed by the rest, so
550
 * we simply scan for ORT instead of PORT...
551
 * DCC doesn't have this problem because there's other stuff
552
 * in the packet before the DCC command.
553
 *
554
 * Return 1 if the mbuf m is still valid and should be
555
 * sbappend()ed
556
 *
557
 * NOTE: if you return 0 you MUST m_free() the mbuf!
558
 */
559
int
560
tcp_emu(struct socket *so, struct mbuf *m)
561
{
562
        Slirp *slirp = so->slirp;
563
        u_int n1, n2, n3, n4, n5, n6;
564
        char buff[257];
565
        uint32_t laddr;
566
        u_int lport;
567
        char *bptr;
568

    
569
        DEBUG_CALL("tcp_emu");
570
        DEBUG_ARG("so = %lx", (long)so);
571
        DEBUG_ARG("m = %lx", (long)m);
572

    
573
        switch(so->so_emu) {
574
                int x, i;
575

    
576
         case EMU_IDENT:
577
                /*
578
                 * Identification protocol as per rfc-1413
579
                 */
580

    
581
                {
582
                        struct socket *tmpso;
583
                        struct sockaddr_in addr;
584
                        socklen_t addrlen = sizeof(struct sockaddr_in);
585
                        struct sbuf *so_rcv = &so->so_rcv;
586

    
587
                        memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
588
                        so_rcv->sb_wptr += m->m_len;
589
                        so_rcv->sb_rptr += m->m_len;
590
                        m->m_data[m->m_len] = 0; /* NULL terminate */
591
                        if (strchr(m->m_data, '\r') || strchr(m->m_data, '\n')) {
592
                                if (sscanf(so_rcv->sb_data, "%u%*[ ,]%u", &n1, &n2) == 2) {
593
                                        HTONS(n1);
594
                                        HTONS(n2);
595
                                        /* n2 is the one on our host */
596
                                        for (tmpso = slirp->tcb.so_next;
597
                                             tmpso != &slirp->tcb;
598
                                             tmpso = tmpso->so_next) {
599
                                                if (tmpso->so_laddr.s_addr == so->so_laddr.s_addr &&
600
                                                    tmpso->so_lport == n2 &&
601
                                                    tmpso->so_faddr.s_addr == so->so_faddr.s_addr &&
602
                                                    tmpso->so_fport == n1) {
603
                                                        if (getsockname(tmpso->s,
604
                                                                (struct sockaddr *)&addr, &addrlen) == 0)
605
                                                           n2 = ntohs(addr.sin_port);
606
                                                        break;
607
                                                }
608
                                        }
609
                                }
610
                                so_rcv->sb_cc = snprintf(so_rcv->sb_data,
611
                                                         so_rcv->sb_datalen,
612
                                                         "%d,%d\r\n", n1, n2);
613
                                so_rcv->sb_rptr = so_rcv->sb_data;
614
                                so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
615
                        }
616
                        m_free(m);
617
                        return 0;
618
                }
619

    
620
        case EMU_FTP: /* ftp */
621
                *(m->m_data+m->m_len) = 0; /* NUL terminate for strstr */
622
                if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
623
                        /*
624
                         * Need to emulate the PORT command
625
                         */
626
                        x = sscanf(bptr, "ORT %u,%u,%u,%u,%u,%u\r\n%256[^\177]",
627
                                   &n1, &n2, &n3, &n4, &n5, &n6, buff);
628
                        if (x < 6)
629
                           return 1;
630

    
631
                        laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
632
                        lport = htons((n5 << 8) | (n6));
633

    
634
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
635
                                             lport, SS_FACCEPTONCE)) == NULL) {
636
                           return 1;
637
                        }
638
                        n6 = ntohs(so->so_fport);
639

    
640
                        n5 = (n6 >> 8) & 0xff;
641
                        n6 &= 0xff;
642

    
643
                        laddr = ntohl(so->so_faddr.s_addr);
644

    
645
                        n1 = ((laddr >> 24) & 0xff);
646
                        n2 = ((laddr >> 16) & 0xff);
647
                        n3 = ((laddr >> 8)  & 0xff);
648
                        n4 =  (laddr & 0xff);
649

    
650
                        m->m_len = bptr - m->m_data; /* Adjust length */
651
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
652
                                             "ORT %d,%d,%d,%d,%d,%d\r\n%s",
653
                                             n1, n2, n3, n4, n5, n6, x==7?buff:"");
654
                        return 1;
655
                } else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
656
                        /*
657
                         * Need to emulate the PASV response
658
                         */
659
                        x = sscanf(bptr, "27 Entering Passive Mode (%u,%u,%u,%u,%u,%u)\r\n%256[^\177]",
660
                                   &n1, &n2, &n3, &n4, &n5, &n6, buff);
661
                        if (x < 6)
662
                           return 1;
663

    
664
                        laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
665
                        lport = htons((n5 << 8) | (n6));
666

    
667
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
668
                                             lport, SS_FACCEPTONCE)) == NULL) {
669
                           return 1;
670
                        }
671
                        n6 = ntohs(so->so_fport);
672

    
673
                        n5 = (n6 >> 8) & 0xff;
674
                        n6 &= 0xff;
675

    
676
                        laddr = ntohl(so->so_faddr.s_addr);
677

    
678
                        n1 = ((laddr >> 24) & 0xff);
679
                        n2 = ((laddr >> 16) & 0xff);
680
                        n3 = ((laddr >> 8)  & 0xff);
681
                        n4 =  (laddr & 0xff);
682

    
683
                        m->m_len = bptr - m->m_data; /* Adjust length */
684
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
685
                                             "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
686
                                             n1, n2, n3, n4, n5, n6, x==7?buff:"");
687

    
688
                        return 1;
689
                }
690

    
691
                return 1;
692

    
693
         case EMU_KSH:
694
                /*
695
                 * The kshell (Kerberos rsh) and shell services both pass
696
                 * a local port port number to carry signals to the server
697
                 * and stderr to the client.  It is passed at the beginning
698
                 * of the connection as a NUL-terminated decimal ASCII string.
699
                 */
700
                so->so_emu = 0;
701
                for (lport = 0, i = 0; i < m->m_len-1; ++i) {
702
                        if (m->m_data[i] < '0' || m->m_data[i] > '9')
703
                                return 1;       /* invalid number */
704
                        lport *= 10;
705
                        lport += m->m_data[i] - '0';
706
                }
707
                if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
708
                    (so = tcp_listen(slirp, INADDR_ANY, 0, so->so_laddr.s_addr,
709
                                     htons(lport), SS_FACCEPTONCE)) != NULL)
710
                    m->m_len = snprintf(m->m_data, m->m_hdr.mh_size, "%d",
711
                                        ntohs(so->so_fport)) + 1;
712
                return 1;
713

    
714
         case EMU_IRC:
715
                /*
716
                 * Need to emulate DCC CHAT, DCC SEND and DCC MOVE
717
                 */
718
                *(m->m_data+m->m_len) = 0; /* NULL terminate the string for strstr */
719
                if ((bptr = (char *)strstr(m->m_data, "DCC")) == NULL)
720
                         return 1;
721

    
722
                /* The %256s is for the broken mIRC */
723
                if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) {
724
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0,
725
                                             htonl(laddr), htons(lport),
726
                                             SS_FACCEPTONCE)) == NULL) {
727
                                return 1;
728
                        }
729
                        m->m_len = bptr - m->m_data; /* Adjust length */
730
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
731
                                             "DCC CHAT chat %lu %u%c\n",
732
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
733
                                             ntohs(so->so_fport), 1);
734
                } else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
735
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0,
736
                                             htonl(laddr), htons(lport),
737
                                             SS_FACCEPTONCE)) == NULL) {
738
                                return 1;
739
                        }
740
                        m->m_len = bptr - m->m_data; /* Adjust length */
741
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
742
                                             "DCC SEND %s %lu %u %u%c\n", buff,
743
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
744
                                             ntohs(so->so_fport), n1, 1);
745
                } else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
746
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0,
747
                                             htonl(laddr), htons(lport),
748
                                             SS_FACCEPTONCE)) == NULL) {
749
                                return 1;
750
                        }
751
                        m->m_len = bptr - m->m_data; /* Adjust length */
752
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
753
                                             "DCC MOVE %s %lu %u %u%c\n", buff,
754
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
755
                                             ntohs(so->so_fport), n1, 1);
756
                }
757
                return 1;
758

    
759
         case EMU_REALAUDIO:
760
                /*
761
                 * RealAudio emulation - JP. We must try to parse the incoming
762
                 * data and try to find the two characters that contain the
763
                 * port number. Then we redirect an udp port and replace the
764
                 * number with the real port we got.
765
                 *
766
                 * The 1.0 beta versions of the player are not supported
767
                 * any more.
768
                 *
769
                 * A typical packet for player version 1.0 (release version):
770
                 *
771
                 * 0000:50 4E 41 00 05
772
                 * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 ........g.l.c..P
773
                 * 0010:4E 43 4C 49 45 4E 54 20 31 30 31 20 41 4C 50 48 NCLIENT 101 ALPH
774
                 * 0020:41 6C 00 00 52 00 17 72 61 66 69 6C 65 73 2F 76 Al..R..rafiles/v
775
                 * 0030:6F 61 2F 65 6E 67 6C 69 73 68 5F 2E 72 61 79 42 oa/english_.rayB
776
                 *
777
                 * Now the port number 0x1BD7 is found at offset 0x04 of the
778
                 * Now the port number 0x1BD7 is found at offset 0x04 of the
779
                 * second packet. This time we received five bytes first and
780
                 * then the rest. You never know how many bytes you get.
781
                 *
782
                 * A typical packet for player version 2.0 (beta):
783
                 *
784
                 * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA.............
785
                 * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .gux.c..Win2.0.0
786
                 * 0020:2E 35 6C 00 00 52 00 1C 72 61 66 69 6C 65 73 2F .5l..R..rafiles/
787
                 * 0030:77 65 62 73 69 74 65 2F 32 30 72 65 6C 65 61 73 website/20releas
788
                 * 0040:65 2E 72 61 79 53 00 00 06 36 42                e.rayS...6B
789
                 *
790
                 * Port number 0x1BC1 is found at offset 0x0d.
791
                 *
792
                 * This is just a horrible switch statement. Variable ra tells
793
                 * us where we're going.
794
                 */
795

    
796
                bptr = m->m_data;
797
                while (bptr < m->m_data + m->m_len) {
798
                        u_short p;
799
                        static int ra = 0;
800
                        char ra_tbl[4];
801

    
802
                        ra_tbl[0] = 0x50;
803
                        ra_tbl[1] = 0x4e;
804
                        ra_tbl[2] = 0x41;
805
                        ra_tbl[3] = 0;
806

    
807
                        switch (ra) {
808
                         case 0:
809
                         case 2:
810
                         case 3:
811
                                if (*bptr++ != ra_tbl[ra]) {
812
                                        ra = 0;
813
                                        continue;
814
                                }
815
                                break;
816

    
817
                         case 1:
818
                                /*
819
                                 * We may get 0x50 several times, ignore them
820
                                 */
821
                                if (*bptr == 0x50) {
822
                                        ra = 1;
823
                                        bptr++;
824
                                        continue;
825
                                } else if (*bptr++ != ra_tbl[ra]) {
826
                                        ra = 0;
827
                                        continue;
828
                                }
829
                                break;
830

    
831
                         case 4:
832
                                /*
833
                                 * skip version number
834
                                 */
835
                                bptr++;
836
                                break;
837

    
838
                         case 5:
839
                                /*
840
                                 * The difference between versions 1.0 and
841
                                 * 2.0 is here. For future versions of
842
                                 * the player this may need to be modified.
843
                                 */
844
                                if (*(bptr + 1) == 0x02)
845
                                   bptr += 8;
846
                                else
847
                                   bptr += 4;
848
                                break;
849

    
850
                         case 6:
851
                                /* This is the field containing the port
852
                                 * number that RA-player is listening to.
853
                                 */
854
                                lport = (((u_char*)bptr)[0] << 8)
855
                                + ((u_char *)bptr)[1];
856
                                if (lport < 6970)
857
                                   lport += 256;   /* don't know why */
858
                                if (lport < 6970 || lport > 7170)
859
                                   return 1;       /* failed */
860

    
861
                                /* try to get udp port between 6970 - 7170 */
862
                                for (p = 6970; p < 7071; p++) {
863
                                        if (udp_listen(slirp, INADDR_ANY,
864
                                                       htons(p),
865
                                                       so->so_laddr.s_addr,
866
                                                       htons(lport),
867
                                                       SS_FACCEPTONCE)) {
868
                                                break;
869
                                        }
870
                                }
871
                                if (p == 7071)
872
                                   p = 0;
873
                                *(u_char *)bptr++ = (p >> 8) & 0xff;
874
                                *(u_char *)bptr = p & 0xff;
875
                                ra = 0;
876
                                return 1;   /* port redirected, we're done */
877
                                break;
878

    
879
                         default:
880
                                ra = 0;
881
                        }
882
                        ra++;
883
                }
884
                return 1;
885

    
886
         default:
887
                /* Ooops, not emulated, won't call tcp_emu again */
888
                so->so_emu = 0;
889
                return 1;
890
        }
891
}
892

    
893
/*
894
 * Do misc. config of SLiRP while its running.
895
 * Return 0 if this connections is to be closed, 1 otherwise,
896
 * return 2 if this is a command-line connection
897
 */
898
int tcp_ctl(struct socket *so)
899
{
900
    Slirp *slirp = so->slirp;
901
    struct sbuf *sb = &so->so_snd;
902
    struct ex_list *ex_ptr;
903
    int do_pty;
904

    
905
    DEBUG_CALL("tcp_ctl");
906
    DEBUG_ARG("so = %lx", (long )so);
907

    
908
    if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr) {
909
        /* Check if it's pty_exec */
910
        for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
911
            if (ex_ptr->ex_fport == so->so_fport &&
912
                so->so_faddr.s_addr == ex_ptr->ex_addr.s_addr) {
913
                if (ex_ptr->ex_pty == 3) {
914
                    so->s = -1;
915
                    so->extra = (void *)ex_ptr->ex_exec;
916
                    return 1;
917
                }
918
                do_pty = ex_ptr->ex_pty;
919
                DEBUG_MISC((dfd, " executing %s\n", ex_ptr->ex_exec));
920
                return fork_exec(so, ex_ptr->ex_exec, do_pty);
921
            }
922
        }
923
    }
924
    sb->sb_cc =
925
        snprintf(sb->sb_wptr, sb->sb_datalen - (sb->sb_wptr - sb->sb_data),
926
                 "Error: No application configured.\r\n");
927
    sb->sb_wptr += sb->sb_cc;
928
    return 0;
929
}