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/*
2
 * Copyright (c) 1982, 1986, 1988, 1990, 1993
3
 *        The Regents of the University of California.  All rights reserved.
4
 *
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 * 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
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 *    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
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 * 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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 *
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 * Please read the file COPYRIGHT for the
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 * 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 */
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    slirp->tcb.so_next = slirp->tcb.so_prev = &slirp->tcb;
55
    slirp->tcp_last_so = &slirp->tcb;
56
}
57

    
58
/*
59
 * Create template to be used to send tcp packets on a connection.
60
 * Call after host entry created, fills
61
 * in a skeletal tcp/ip header, minimizing the amount of work
62
 * necessary when the connection is used.
63
 */
64
void
65
tcp_template(struct tcpcb *tp)
66
{
67
        struct socket *so = tp->t_socket;
68
        register struct tcpiphdr *n = &tp->t_template;
69

    
70
        n->ti_mbuf = NULL;
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        n->ti_x1 = 0;
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        n->ti_pr = IPPROTO_TCP;
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        n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip));
74
        n->ti_src = so->so_faddr;
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        n->ti_dst = so->so_laddr;
76
        n->ti_sport = so->so_fport;
77
        n->ti_dport = so->so_lport;
78

    
79
        n->ti_seq = 0;
80
        n->ti_ack = 0;
81
        n->ti_x2 = 0;
82
        n->ti_off = 5;
83
        n->ti_flags = 0;
84
        n->ti_win = 0;
85
        n->ti_sum = 0;
86
        n->ti_urp = 0;
87
}
88

    
89
/*
90
 * Send a single message to the TCP at address specified by
91
 * the given TCP/IP header.  If m == 0, then we make a copy
92
 * of the tcpiphdr at ti and send directly to the addressed host.
93
 * This is used to force keep alive messages out using the TCP
94
 * template for a connection tp->t_template.  If flags are given
95
 * then we send a message back to the TCP which originated the
96
 * segment ti, and discard the mbuf containing it and any other
97
 * attached mbufs.
98
 *
99
 * In any case the ack and sequence number of the transmitted
100
 * segment are as specified by the parameters.
101
 */
102
void
103
tcp_respond(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m,
104
            tcp_seq ack, tcp_seq seq, int flags)
105
{
106
        register int tlen;
107
        int win = 0;
108

    
109
        DEBUG_CALL("tcp_respond");
110
        DEBUG_ARG("tp = %lx", (long)tp);
111
        DEBUG_ARG("ti = %lx", (long)ti);
112
        DEBUG_ARG("m = %lx", (long)m);
113
        DEBUG_ARG("ack = %u", ack);
114
        DEBUG_ARG("seq = %u", seq);
115
        DEBUG_ARG("flags = %x", flags);
116

    
117
        if (tp)
118
                win = sbspace(&tp->t_socket->so_rcv);
119
        if (m == NULL) {
120
                if ((m = m_get(tp->t_socket->slirp)) == NULL)
121
                        return;
122
                tlen = 0;
123
                m->m_data += IF_MAXLINKHDR;
124
                *mtod(m, struct tcpiphdr *) = *ti;
125
                ti = mtod(m, struct tcpiphdr *);
126
                flags = TH_ACK;
127
        } else {
128
                /*
129
                 * ti points into m so the next line is just making
130
                 * the mbuf point to ti
131
                 */
132
                m->m_data = (caddr_t)ti;
133

    
134
                m->m_len = sizeof (struct tcpiphdr);
135
                tlen = 0;
136
#define xchg(a,b,type) { type t; t=a; a=b; b=t; }
137
                xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, uint32_t);
138
                xchg(ti->ti_dport, ti->ti_sport, uint16_t);
139
#undef xchg
140
        }
141
        ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen));
142
        tlen += sizeof (struct tcpiphdr);
143
        m->m_len = tlen;
144

    
145
        ti->ti_mbuf = NULL;
146
        ti->ti_x1 = 0;
147
        ti->ti_seq = htonl(seq);
148
        ti->ti_ack = htonl(ack);
149
        ti->ti_x2 = 0;
150
        ti->ti_off = sizeof (struct tcphdr) >> 2;
151
        ti->ti_flags = flags;
152
        if (tp)
153
                ti->ti_win = htons((uint16_t) (win >> tp->rcv_scale));
154
        else
155
                ti->ti_win = htons((uint16_t)win);
156
        ti->ti_urp = 0;
157
        ti->ti_sum = 0;
158
        ti->ti_sum = cksum(m, tlen);
159
        ((struct ip *)ti)->ip_len = tlen;
160

    
161
        if(flags & TH_RST)
162
          ((struct ip *)ti)->ip_ttl = MAXTTL;
163
        else
164
          ((struct ip *)ti)->ip_ttl = IPDEFTTL;
165

    
166
        (void) ip_output((struct socket *)0, m);
167
}
168

    
169
/*
170
 * Create a new TCP control block, making an
171
 * empty reassembly queue and hooking it to the argument
172
 * protocol control block.
173
 */
174
struct tcpcb *
175
tcp_newtcpcb(struct socket *so)
176
{
177
        register struct tcpcb *tp;
178

    
179
        tp = (struct tcpcb *)malloc(sizeof(*tp));
180
        if (tp == NULL)
181
                return ((struct tcpcb *)0);
182

    
183
        memset((char *) tp, 0, sizeof(struct tcpcb));
184
        tp->seg_next = tp->seg_prev = (struct tcpiphdr*)tp;
185
        tp->t_maxseg = TCP_MSS;
186

    
187
        tp->t_flags = TCP_DO_RFC1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0;
188
        tp->t_socket = so;
189

    
190
        /*
191
         * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
192
         * rtt estimate.  Set rttvar so that srtt + 2 * rttvar gives
193
         * reasonable initial retransmit time.
194
         */
195
        tp->t_srtt = TCPTV_SRTTBASE;
196
        tp->t_rttvar = TCPTV_SRTTDFLT << 2;
197
        tp->t_rttmin = TCPTV_MIN;
198

    
199
        TCPT_RANGESET(tp->t_rxtcur,
200
            ((TCPTV_SRTTBASE >> 2) + (TCPTV_SRTTDFLT << 2)) >> 1,
201
            TCPTV_MIN, TCPTV_REXMTMAX);
202

    
203
        tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
204
        tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
205
        tp->t_state = TCPS_CLOSED;
206

    
207
        so->so_tcpcb = tp;
208

    
209
        return (tp);
210
}
211

    
212
/*
213
 * Drop a TCP connection, reporting
214
 * the specified error.  If connection is synchronized,
215
 * then send a RST to peer.
216
 */
217
struct tcpcb *tcp_drop(struct tcpcb *tp, int err)
218
{
219
        DEBUG_CALL("tcp_drop");
220
        DEBUG_ARG("tp = %lx", (long)tp);
221
        DEBUG_ARG("errno = %d", errno);
222

    
223
        if (TCPS_HAVERCVDSYN(tp->t_state)) {
224
                tp->t_state = TCPS_CLOSED;
225
                (void) tcp_output(tp);
226
        }
227
        return (tcp_close(tp));
228
}
229

    
230
/*
231
 * Close a TCP control block:
232
 *        discard all space held by the tcp
233
 *        discard internet protocol block
234
 *        wake up any sleepers
235
 */
236
struct tcpcb *
237
tcp_close(struct tcpcb *tp)
238
{
239
        register struct tcpiphdr *t;
240
        struct socket *so = tp->t_socket;
241
        Slirp *slirp = so->slirp;
242
        register struct mbuf *m;
243

    
244
        DEBUG_CALL("tcp_close");
245
        DEBUG_ARG("tp = %lx", (long )tp);
246

    
247
        /* free the reassembly queue, if any */
248
        t = tcpfrag_list_first(tp);
249
        while (!tcpfrag_list_end(t, tp)) {
250
                t = tcpiphdr_next(t);
251
                m = tcpiphdr_prev(t)->ti_mbuf;
252
                remque(tcpiphdr2qlink(tcpiphdr_prev(t)));
253
                m_freem(m);
254
        }
255
        free(tp);
256
        so->so_tcpcb = NULL;
257
        /* clobber input socket cache if we're closing the cached connection */
258
        if (so == slirp->tcp_last_so)
259
                slirp->tcp_last_so = &slirp->tcb;
260
        closesocket(so->s);
261
        sbfree(&so->so_rcv);
262
        sbfree(&so->so_snd);
263
        sofree(so);
264
        return ((struct tcpcb *)0);
265
}
266

    
267
/*
268
 * TCP protocol interface to socket abstraction.
269
 */
270

    
271
/*
272
 * User issued close, and wish to trail through shutdown states:
273
 * if never received SYN, just forget it.  If got a SYN from peer,
274
 * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
275
 * If already got a FIN from peer, then almost done; go to LAST_ACK
276
 * state.  In all other cases, have already sent FIN to peer (e.g.
277
 * after PRU_SHUTDOWN), and just have to play tedious game waiting
278
 * for peer to send FIN or not respond to keep-alives, etc.
279
 * We can let the user exit from the close as soon as the FIN is acked.
280
 */
281
void
282
tcp_sockclosed(struct tcpcb *tp)
283
{
284

    
285
        DEBUG_CALL("tcp_sockclosed");
286
        DEBUG_ARG("tp = %lx", (long)tp);
287

    
288
        switch (tp->t_state) {
289

    
290
        case TCPS_CLOSED:
291
        case TCPS_LISTEN:
292
        case TCPS_SYN_SENT:
293
                tp->t_state = TCPS_CLOSED;
294
                tp = tcp_close(tp);
295
                break;
296

    
297
        case TCPS_SYN_RECEIVED:
298
        case TCPS_ESTABLISHED:
299
                tp->t_state = TCPS_FIN_WAIT_1;
300
                break;
301

    
302
        case TCPS_CLOSE_WAIT:
303
                tp->t_state = TCPS_LAST_ACK;
304
                break;
305
        }
306
        if (tp)
307
                tcp_output(tp);
308
}
309

    
310
/*
311
 * Connect to a host on the Internet
312
 * Called by tcp_input
313
 * Only do a connect, the tcp fields will be set in tcp_input
314
 * return 0 if there's a result of the connect,
315
 * else return -1 means we're still connecting
316
 * The return value is almost always -1 since the socket is
317
 * nonblocking.  Connect returns after the SYN is sent, and does
318
 * not wait for ACK+SYN.
319
 */
320
int tcp_fconnect(struct socket *so)
321
{
322
  Slirp *slirp = so->slirp;
323
  int ret=0;
324

    
325
  DEBUG_CALL("tcp_fconnect");
326
  DEBUG_ARG("so = %lx", (long )so);
327

    
328
  if( (ret = so->s = qemu_socket(AF_INET,SOCK_STREAM,0)) >= 0) {
329
    int opt, s=so->s;
330
    struct sockaddr_in addr;
331

    
332
    fd_nonblock(s);
333
    opt = 1;
334
    setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(opt ));
335
    opt = 1;
336
    setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(opt ));
337

    
338
    addr.sin_family = AF_INET;
339
    if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
340
        slirp->vnetwork_addr.s_addr) {
341
      /* It's an alias */
342
      if (so->so_faddr.s_addr == slirp->vnameserver_addr.s_addr) {
343
        if (get_dns_addr(&addr.sin_addr) < 0)
344
          addr.sin_addr = loopback_addr;
345
      } else {
346
        addr.sin_addr = loopback_addr;
347
      }
348
    } else
349
      addr.sin_addr = so->so_faddr;
350
    addr.sin_port = so->so_fport;
351

    
352
    DEBUG_MISC((dfd, " connect()ing, addr.sin_port=%d, "
353
                "addr.sin_addr.s_addr=%.16s\n",
354
                ntohs(addr.sin_port), inet_ntoa(addr.sin_addr)));
355
    /* We don't care what port we get */
356
    ret = connect(s,(struct sockaddr *)&addr,sizeof (addr));
357

    
358
    /*
359
     * If it's not in progress, it failed, so we just return 0,
360
     * without clearing SS_NOFDREF
361
     */
362
    soisfconnecting(so);
363
  }
364

    
365
  return(ret);
366
}
367

    
368
/*
369
 * Accept the socket and connect to the local-host
370
 *
371
 * We have a problem. The correct thing to do would be
372
 * to first connect to the local-host, and only if the
373
 * connection is accepted, then do an accept() here.
374
 * But, a) we need to know who's trying to connect
375
 * to the socket to be able to SYN the local-host, and
376
 * b) we are already connected to the foreign host by
377
 * the time it gets to accept(), so... We simply accept
378
 * here and SYN the local-host.
379
 */
380
void
381
tcp_connect(struct socket *inso)
382
{
383
        Slirp *slirp = inso->slirp;
384
        struct socket *so;
385
        struct sockaddr_in addr;
386
        socklen_t addrlen = sizeof(struct sockaddr_in);
387
        struct tcpcb *tp;
388
        int s, opt;
389

    
390
        DEBUG_CALL("tcp_connect");
391
        DEBUG_ARG("inso = %lx", (long)inso);
392

    
393
        /*
394
         * If it's an SS_ACCEPTONCE socket, no need to socreate()
395
         * another socket, just use the accept() socket.
396
         */
397
        if (inso->so_state & SS_FACCEPTONCE) {
398
                /* FACCEPTONCE already have a tcpcb */
399
                so = inso;
400
        } else {
401
                if ((so = socreate(slirp)) == NULL) {
402
                        /* If it failed, get rid of the pending connection */
403
                        closesocket(accept(inso->s,(struct sockaddr *)&addr,&addrlen));
404
                        return;
405
                }
406
                if (tcp_attach(so) < 0) {
407
                        free(so); /* NOT sofree */
408
                        return;
409
                }
410
                so->so_laddr = inso->so_laddr;
411
                so->so_lport = inso->so_lport;
412
        }
413

    
414
        (void) tcp_mss(sototcpcb(so), 0);
415

    
416
        if ((s = accept(inso->s,(struct sockaddr *)&addr,&addrlen)) < 0) {
417
                tcp_close(sototcpcb(so)); /* This will sofree() as well */
418
                return;
419
        }
420
        fd_nonblock(s);
421
        opt = 1;
422
        setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
423
        opt = 1;
424
        setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
425
        opt = 1;
426
        setsockopt(s,IPPROTO_TCP,TCP_NODELAY,(char *)&opt,sizeof(int));
427

    
428
        so->so_fport = addr.sin_port;
429
        so->so_faddr = addr.sin_addr;
430
        /* Translate connections from localhost to the real hostname */
431
        if (so->so_faddr.s_addr == 0 || so->so_faddr.s_addr == loopback_addr.s_addr)
432
           so->so_faddr = slirp->vhost_addr;
433

    
434
        /* Close the accept() socket, set right state */
435
        if (inso->so_state & SS_FACCEPTONCE) {
436
                closesocket(so->s); /* If we only accept once, close the accept() socket */
437
                so->so_state = SS_NOFDREF; /* Don't select it yet, even though we have an FD */
438
                                           /* if it's not FACCEPTONCE, it's already NOFDREF */
439
        }
440
        so->s = s;
441
        so->so_state |= SS_INCOMING;
442

    
443
        so->so_iptos = tcp_tos(so);
444
        tp = sototcpcb(so);
445

    
446
        tcp_template(tp);
447

    
448
        tp->t_state = TCPS_SYN_SENT;
449
        tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
450
        tp->iss = slirp->tcp_iss;
451
        slirp->tcp_iss += TCP_ISSINCR/2;
452
        tcp_sendseqinit(tp);
453
        tcp_output(tp);
454
}
455

    
456
/*
457
 * Attach a TCPCB to a socket.
458
 */
459
int
460
tcp_attach(struct socket *so)
461
{
462
        if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
463
           return -1;
464

    
465
        insque(so, &so->slirp->tcb);
466

    
467
        return 0;
468
}
469

    
470
/*
471
 * Set the socket's type of service field
472
 */
473
static const struct tos_t tcptos[] = {
474
          {0, 20, IPTOS_THROUGHPUT, 0},        /* ftp data */
475
          {21, 21, IPTOS_LOWDELAY,  EMU_FTP},        /* ftp control */
476
          {0, 23, IPTOS_LOWDELAY, 0},        /* telnet */
477
          {0, 80, IPTOS_THROUGHPUT, 0},        /* WWW */
478
          {0, 513, IPTOS_LOWDELAY, EMU_RLOGIN|EMU_NOCONNECT},        /* rlogin */
479
          {0, 514, IPTOS_LOWDELAY, EMU_RSH|EMU_NOCONNECT},        /* shell */
480
          {0, 544, IPTOS_LOWDELAY, EMU_KSH},                /* kshell */
481
          {0, 543, IPTOS_LOWDELAY, 0},        /* klogin */
482
          {0, 6667, IPTOS_THROUGHPUT, EMU_IRC},        /* IRC */
483
          {0, 6668, IPTOS_THROUGHPUT, EMU_IRC},        /* IRC undernet */
484
          {0, 7070, IPTOS_LOWDELAY, EMU_REALAUDIO }, /* RealAudio control */
485
          {0, 113, IPTOS_LOWDELAY, EMU_IDENT }, /* identd protocol */
486
          {0, 0, 0, 0}
487
};
488

    
489
static struct emu_t *tcpemu = NULL;
490

    
491
/*
492
 * Return TOS according to the above table
493
 */
494
uint8_t
495
tcp_tos(struct socket *so)
496
{
497
        int i = 0;
498
        struct emu_t *emup;
499

    
500
        while(tcptos[i].tos) {
501
                if ((tcptos[i].fport && (ntohs(so->so_fport) == tcptos[i].fport)) ||
502
                    (tcptos[i].lport && (ntohs(so->so_lport) == tcptos[i].lport))) {
503
                        so->so_emu = tcptos[i].emu;
504
                        return tcptos[i].tos;
505
                }
506
                i++;
507
        }
508

    
509
        /* Nope, lets see if there's a user-added one */
510
        for (emup = tcpemu; emup; emup = emup->next) {
511
                if ((emup->fport && (ntohs(so->so_fport) == emup->fport)) ||
512
                    (emup->lport && (ntohs(so->so_lport) == emup->lport))) {
513
                        so->so_emu = emup->emu;
514
                        return emup->tos;
515
                }
516
        }
517

    
518
        return 0;
519
}
520

    
521
/*
522
 * Emulate programs that try and connect to us
523
 * This includes ftp (the data connection is
524
 * initiated by the server) and IRC (DCC CHAT and
525
 * DCC SEND) for now
526
 *
527
 * NOTE: It's possible to crash SLiRP by sending it
528
 * unstandard strings to emulate... if this is a problem,
529
 * more checks are needed here
530
 *
531
 * XXX Assumes the whole command came in one packet
532
 *
533
 * XXX Some ftp clients will have their TOS set to
534
 * LOWDELAY and so Nagel will kick in.  Because of this,
535
 * we'll get the first letter, followed by the rest, so
536
 * we simply scan for ORT instead of PORT...
537
 * DCC doesn't have this problem because there's other stuff
538
 * in the packet before the DCC command.
539
 *
540
 * Return 1 if the mbuf m is still valid and should be
541
 * sbappend()ed
542
 *
543
 * NOTE: if you return 0 you MUST m_free() the mbuf!
544
 */
545
int
546
tcp_emu(struct socket *so, struct mbuf *m)
547
{
548
        Slirp *slirp = so->slirp;
549
        u_int n1, n2, n3, n4, n5, n6;
550
        char buff[257];
551
        uint32_t laddr;
552
        u_int lport;
553
        char *bptr;
554

    
555
        DEBUG_CALL("tcp_emu");
556
        DEBUG_ARG("so = %lx", (long)so);
557
        DEBUG_ARG("m = %lx", (long)m);
558

    
559
        switch(so->so_emu) {
560
                int x, i;
561

    
562
         case EMU_IDENT:
563
                /*
564
                 * Identification protocol as per rfc-1413
565
                 */
566

    
567
                {
568
                        struct socket *tmpso;
569
                        struct sockaddr_in addr;
570
                        socklen_t addrlen = sizeof(struct sockaddr_in);
571
                        struct sbuf *so_rcv = &so->so_rcv;
572

    
573
                        memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
574
                        so_rcv->sb_wptr += m->m_len;
575
                        so_rcv->sb_rptr += m->m_len;
576
                        m->m_data[m->m_len] = 0; /* NULL terminate */
577
                        if (strchr(m->m_data, '\r') || strchr(m->m_data, '\n')) {
578
                                if (sscanf(so_rcv->sb_data, "%u%*[ ,]%u", &n1, &n2) == 2) {
579
                                        HTONS(n1);
580
                                        HTONS(n2);
581
                                        /* n2 is the one on our host */
582
                                        for (tmpso = slirp->tcb.so_next;
583
                                             tmpso != &slirp->tcb;
584
                                             tmpso = tmpso->so_next) {
585
                                                if (tmpso->so_laddr.s_addr == so->so_laddr.s_addr &&
586
                                                    tmpso->so_lport == n2 &&
587
                                                    tmpso->so_faddr.s_addr == so->so_faddr.s_addr &&
588
                                                    tmpso->so_fport == n1) {
589
                                                        if (getsockname(tmpso->s,
590
                                                                (struct sockaddr *)&addr, &addrlen) == 0)
591
                                                           n2 = ntohs(addr.sin_port);
592
                                                        break;
593
                                                }
594
                                        }
595
                                }
596
                                so_rcv->sb_cc = snprintf(so_rcv->sb_data,
597
                                                         so_rcv->sb_datalen,
598
                                                         "%d,%d\r\n", n1, n2);
599
                                so_rcv->sb_rptr = so_rcv->sb_data;
600
                                so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
601
                        }
602
                        m_free(m);
603
                        return 0;
604
                }
605

    
606
        case EMU_FTP: /* ftp */
607
                *(m->m_data+m->m_len) = 0; /* NUL terminate for strstr */
608
                if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
609
                        /*
610
                         * Need to emulate the PORT command
611
                         */
612
                        x = sscanf(bptr, "ORT %u,%u,%u,%u,%u,%u\r\n%256[^\177]",
613
                                   &n1, &n2, &n3, &n4, &n5, &n6, buff);
614
                        if (x < 6)
615
                           return 1;
616

    
617
                        laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
618
                        lport = htons((n5 << 8) | (n6));
619

    
620
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
621
                                             lport, SS_FACCEPTONCE)) == NULL) {
622
                           return 1;
623
                        }
624
                        n6 = ntohs(so->so_fport);
625

    
626
                        n5 = (n6 >> 8) & 0xff;
627
                        n6 &= 0xff;
628

    
629
                        laddr = ntohl(so->so_faddr.s_addr);
630

    
631
                        n1 = ((laddr >> 24) & 0xff);
632
                        n2 = ((laddr >> 16) & 0xff);
633
                        n3 = ((laddr >> 8)  & 0xff);
634
                        n4 =  (laddr & 0xff);
635

    
636
                        m->m_len = bptr - m->m_data; /* Adjust length */
637
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
638
                                             "ORT %d,%d,%d,%d,%d,%d\r\n%s",
639
                                             n1, n2, n3, n4, n5, n6, x==7?buff:"");
640
                        return 1;
641
                } else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
642
                        /*
643
                         * Need to emulate the PASV response
644
                         */
645
                        x = sscanf(bptr, "27 Entering Passive Mode (%u,%u,%u,%u,%u,%u)\r\n%256[^\177]",
646
                                   &n1, &n2, &n3, &n4, &n5, &n6, buff);
647
                        if (x < 6)
648
                           return 1;
649

    
650
                        laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
651
                        lport = htons((n5 << 8) | (n6));
652

    
653
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr,
654
                                             lport, SS_FACCEPTONCE)) == NULL) {
655
                           return 1;
656
                        }
657
                        n6 = ntohs(so->so_fport);
658

    
659
                        n5 = (n6 >> 8) & 0xff;
660
                        n6 &= 0xff;
661

    
662
                        laddr = ntohl(so->so_faddr.s_addr);
663

    
664
                        n1 = ((laddr >> 24) & 0xff);
665
                        n2 = ((laddr >> 16) & 0xff);
666
                        n3 = ((laddr >> 8)  & 0xff);
667
                        n4 =  (laddr & 0xff);
668

    
669
                        m->m_len = bptr - m->m_data; /* Adjust length */
670
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len,
671
                                             "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
672
                                             n1, n2, n3, n4, n5, n6, x==7?buff:"");
673

    
674
                        return 1;
675
                }
676

    
677
                return 1;
678

    
679
         case EMU_KSH:
680
                /*
681
                 * The kshell (Kerberos rsh) and shell services both pass
682
                 * a local port port number to carry signals to the server
683
                 * and stderr to the client.  It is passed at the beginning
684
                 * of the connection as a NUL-terminated decimal ASCII string.
685
                 */
686
                so->so_emu = 0;
687
                for (lport = 0, i = 0; i < m->m_len-1; ++i) {
688
                        if (m->m_data[i] < '0' || m->m_data[i] > '9')
689
                                return 1;       /* invalid number */
690
                        lport *= 10;
691
                        lport += m->m_data[i] - '0';
692
                }
693
                if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
694
                    (so = tcp_listen(slirp, INADDR_ANY, 0, so->so_laddr.s_addr,
695
                                     htons(lport), SS_FACCEPTONCE)) != NULL)
696
                    m->m_len = snprintf(m->m_data, m->m_hdr.mh_size, "%d",
697
                                        ntohs(so->so_fport)) + 1;
698
                return 1;
699

    
700
         case EMU_IRC:
701
                /*
702
                 * Need to emulate DCC CHAT, DCC SEND and DCC MOVE
703
                 */
704
                *(m->m_data+m->m_len) = 0; /* NULL terminate the string for strstr */
705
                if ((bptr = (char *)strstr(m->m_data, "DCC")) == NULL)
706
                         return 1;
707

    
708
                /* The %256s is for the broken mIRC */
709
                if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) {
710
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0,
711
                                             htonl(laddr), htons(lport),
712
                                             SS_FACCEPTONCE)) == NULL) {
713
                                return 1;
714
                        }
715
                        m->m_len = bptr - m->m_data; /* Adjust length */
716
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
717
                                             "DCC CHAT chat %lu %u%c\n",
718
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
719
                                             ntohs(so->so_fport), 1);
720
                } else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
721
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0,
722
                                             htonl(laddr), htons(lport),
723
                                             SS_FACCEPTONCE)) == NULL) {
724
                                return 1;
725
                        }
726
                        m->m_len = bptr - m->m_data; /* Adjust length */
727
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
728
                                             "DCC SEND %s %lu %u %u%c\n", buff,
729
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
730
                                             ntohs(so->so_fport), n1, 1);
731
                } else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
732
                        if ((so = tcp_listen(slirp, INADDR_ANY, 0,
733
                                             htonl(laddr), htons(lport),
734
                                             SS_FACCEPTONCE)) == NULL) {
735
                                return 1;
736
                        }
737
                        m->m_len = bptr - m->m_data; /* Adjust length */
738
                        m->m_len += snprintf(bptr, m->m_hdr.mh_size,
739
                                             "DCC MOVE %s %lu %u %u%c\n", buff,
740
                                             (unsigned long)ntohl(so->so_faddr.s_addr),
741
                                             ntohs(so->so_fport), n1, 1);
742
                }
743
                return 1;
744

    
745
         case EMU_REALAUDIO:
746
                /*
747
                 * RealAudio emulation - JP. We must try to parse the incoming
748
                 * data and try to find the two characters that contain the
749
                 * port number. Then we redirect an udp port and replace the
750
                 * number with the real port we got.
751
                 *
752
                 * The 1.0 beta versions of the player are not supported
753
                 * any more.
754
                 *
755
                 * A typical packet for player version 1.0 (release version):
756
                 *
757
                 * 0000:50 4E 41 00 05
758
                 * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 ........g.l.c..P
759
                 * 0010:4E 43 4C 49 45 4E 54 20 31 30 31 20 41 4C 50 48 NCLIENT 101 ALPH
760
                 * 0020:41 6C 00 00 52 00 17 72 61 66 69 6C 65 73 2F 76 Al..R..rafiles/v
761
                 * 0030:6F 61 2F 65 6E 67 6C 69 73 68 5F 2E 72 61 79 42 oa/english_.rayB
762
                 *
763
                 * Now the port number 0x1BD7 is found at offset 0x04 of the
764
                 * Now the port number 0x1BD7 is found at offset 0x04 of the
765
                 * second packet. This time we received five bytes first and
766
                 * then the rest. You never know how many bytes you get.
767
                 *
768
                 * A typical packet for player version 2.0 (beta):
769
                 *
770
                 * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA.............
771
                 * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .gux.c..Win2.0.0
772
                 * 0020:2E 35 6C 00 00 52 00 1C 72 61 66 69 6C 65 73 2F .5l..R..rafiles/
773
                 * 0030:77 65 62 73 69 74 65 2F 32 30 72 65 6C 65 61 73 website/20releas
774
                 * 0040:65 2E 72 61 79 53 00 00 06 36 42                e.rayS...6B
775
                 *
776
                 * Port number 0x1BC1 is found at offset 0x0d.
777
                 *
778
                 * This is just a horrible switch statement. Variable ra tells
779
                 * us where we're going.
780
                 */
781

    
782
                bptr = m->m_data;
783
                while (bptr < m->m_data + m->m_len) {
784
                        u_short p;
785
                        static int ra = 0;
786
                        char ra_tbl[4];
787

    
788
                        ra_tbl[0] = 0x50;
789
                        ra_tbl[1] = 0x4e;
790
                        ra_tbl[2] = 0x41;
791
                        ra_tbl[3] = 0;
792

    
793
                        switch (ra) {
794
                         case 0:
795
                         case 2:
796
                         case 3:
797
                                if (*bptr++ != ra_tbl[ra]) {
798
                                        ra = 0;
799
                                        continue;
800
                                }
801
                                break;
802

    
803
                         case 1:
804
                                /*
805
                                 * We may get 0x50 several times, ignore them
806
                                 */
807
                                if (*bptr == 0x50) {
808
                                        ra = 1;
809
                                        bptr++;
810
                                        continue;
811
                                } else if (*bptr++ != ra_tbl[ra]) {
812
                                        ra = 0;
813
                                        continue;
814
                                }
815
                                break;
816

    
817
                         case 4:
818
                                /*
819
                                 * skip version number
820
                                 */
821
                                bptr++;
822
                                break;
823

    
824
                         case 5:
825
                                /*
826
                                 * The difference between versions 1.0 and
827
                                 * 2.0 is here. For future versions of
828
                                 * the player this may need to be modified.
829
                                 */
830
                                if (*(bptr + 1) == 0x02)
831
                                   bptr += 8;
832
                                else
833
                                   bptr += 4;
834
                                break;
835

    
836
                         case 6:
837
                                /* This is the field containing the port
838
                                 * number that RA-player is listening to.
839
                                 */
840
                                lport = (((u_char*)bptr)[0] << 8)
841
                                + ((u_char *)bptr)[1];
842
                                if (lport < 6970)
843
                                   lport += 256;   /* don't know why */
844
                                if (lport < 6970 || lport > 7170)
845
                                   return 1;       /* failed */
846

    
847
                                /* try to get udp port between 6970 - 7170 */
848
                                for (p = 6970; p < 7071; p++) {
849
                                        if (udp_listen(slirp, INADDR_ANY,
850
                                                       htons(p),
851
                                                       so->so_laddr.s_addr,
852
                                                       htons(lport),
853
                                                       SS_FACCEPTONCE)) {
854
                                                break;
855
                                        }
856
                                }
857
                                if (p == 7071)
858
                                   p = 0;
859
                                *(u_char *)bptr++ = (p >> 8) & 0xff;
860
                                *(u_char *)bptr = p & 0xff;
861
                                ra = 0;
862
                                return 1;   /* port redirected, we're done */
863
                                break;
864

    
865
                         default:
866
                                ra = 0;
867
                        }
868
                        ra++;
869
                }
870
                return 1;
871

    
872
         default:
873
                /* Ooops, not emulated, won't call tcp_emu again */
874
                so->so_emu = 0;
875
                return 1;
876
        }
877
}
878

    
879
/*
880
 * Do misc. config of SLiRP while its running.
881
 * Return 0 if this connections is to be closed, 1 otherwise,
882
 * return 2 if this is a command-line connection
883
 */
884
int tcp_ctl(struct socket *so)
885
{
886
    Slirp *slirp = so->slirp;
887
    struct sbuf *sb = &so->so_snd;
888
    struct ex_list *ex_ptr;
889
    int do_pty;
890

    
891
    DEBUG_CALL("tcp_ctl");
892
    DEBUG_ARG("so = %lx", (long )so);
893

    
894
    if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr) {
895
        /* Check if it's pty_exec */
896
        for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
897
            if (ex_ptr->ex_fport == so->so_fport &&
898
                so->so_faddr.s_addr == ex_ptr->ex_addr.s_addr) {
899
                if (ex_ptr->ex_pty == 3) {
900
                    so->s = -1;
901
                    so->extra = (void *)ex_ptr->ex_exec;
902
                    return 1;
903
                }
904
                do_pty = ex_ptr->ex_pty;
905
                DEBUG_MISC((dfd, " executing %s \n",ex_ptr->ex_exec));
906
                return fork_exec(so, ex_ptr->ex_exec, do_pty);
907
            }
908
        }
909
    }
910
    sb->sb_cc =
911
        snprintf(sb->sb_wptr, sb->sb_datalen - (sb->sb_wptr - sb->sb_data),
912
                 "Error: No application configured.\r\n");
913
    sb->sb_wptr += sb->sb_cc;
914
    return 0;
915
}