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root/cebix/BasiliskII/src/slirp/tcp_subr.c
Revision: 1.3
Committed: 2007-01-22T14:48:40Z (17 years, 10 months ago) by asvitkine
Content type: text/plain
Branch: MAIN
Changes since 1.2: +1 -0 lines
Log Message:
fix compile warnings w/ slirp caused by not including stdlib

File Contents

# User Rev Content
1 gbeauche 1.1 /*
2     * Copyright (c) 1982, 1986, 1988, 1990, 1993
3     * The Regents of the University of California. All rights reserved.
4     *
5     * Redistribution and use in source and binary forms, with or without
6     * modification, are permitted provided that the following conditions
7     * are met:
8     * 1. Redistributions of source code must retain the above copyright
9     * notice, this list of conditions and the following disclaimer.
10     * 2. Redistributions in binary form must reproduce the above copyright
11     * notice, this list of conditions and the following disclaimer in the
12     * documentation and/or other materials provided with the distribution.
13     * 3. All advertising materials mentioning features or use of this software
14     * must display the following acknowledgement:
15     * This product includes software developed by the University of
16     * California, Berkeley and its contributors.
17     * 4. Neither the name of the University nor the names of its contributors
18     * may be used to endorse or promote products derived from this software
19     * without specific prior written permission.
20     *
21     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24     * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31     * SUCH DAMAGE.
32     *
33     * @(#)tcp_subr.c 8.1 (Berkeley) 6/10/93
34     * tcp_subr.c,v 1.5 1994/10/08 22:39:58 phk Exp
35     */
36    
37     /*
38     * Changes and additions relating to SLiRP
39     * Copyright (c) 1995 Danny Gasparovski.
40     *
41     * Please read the file COPYRIGHT for the
42     * terms and conditions of the copyright.
43     */
44    
45     #define WANT_SYS_IOCTL_H
46 asvitkine 1.3 #include <stdlib.h>
47 gbeauche 1.1 #include <slirp.h>
48    
49     /* patchable/settable parameters for tcp */
50     int tcp_mssdflt = TCP_MSS;
51     int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ;
52     int tcp_do_rfc1323 = 0; /* Don't do rfc1323 performance enhancements */
53     int tcp_rcvspace; /* You may want to change this */
54     int tcp_sndspace; /* Keep small if you have an error prone link */
55    
56     /*
57     * Tcp initialization
58     */
59     void
60     tcp_init()
61     {
62     tcp_iss = 1; /* wrong */
63     tcb.so_next = tcb.so_prev = &tcb;
64    
65     /* tcp_rcvspace = our Window we advertise to the remote */
66     tcp_rcvspace = TCP_RCVSPACE;
67     tcp_sndspace = TCP_SNDSPACE;
68    
69     /* Make sure tcp_sndspace is at least 2*MSS */
70     if (tcp_sndspace < 2*(min(if_mtu, if_mru) - sizeof(struct tcpiphdr)))
71     tcp_sndspace = 2*(min(if_mtu, if_mru) - sizeof(struct tcpiphdr));
72     }
73    
74     /*
75     * Create template to be used to send tcp packets on a connection.
76     * Call after host entry created, fills
77     * in a skeletal tcp/ip header, minimizing the amount of work
78     * necessary when the connection is used.
79     */
80     /* struct tcpiphdr * */
81     void
82     tcp_template(tp)
83     struct tcpcb *tp;
84     {
85     struct socket *so = tp->t_socket;
86     register struct tcpiphdr *n = &tp->t_template;
87    
88     n->ti_next = n->ti_prev = 0;
89     n->ti_x1 = 0;
90     n->ti_pr = IPPROTO_TCP;
91     n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip));
92     n->ti_src = so->so_faddr;
93     n->ti_dst = so->so_laddr;
94     n->ti_sport = so->so_fport;
95     n->ti_dport = so->so_lport;
96    
97     n->ti_seq = 0;
98     n->ti_ack = 0;
99     n->ti_x2 = 0;
100     n->ti_off = 5;
101     n->ti_flags = 0;
102     n->ti_win = 0;
103     n->ti_sum = 0;
104     n->ti_urp = 0;
105     }
106    
107     /*
108     * Send a single message to the TCP at address specified by
109     * the given TCP/IP header. If m == 0, then we make a copy
110     * of the tcpiphdr at ti and send directly to the addressed host.
111     * This is used to force keep alive messages out using the TCP
112     * template for a connection tp->t_template. If flags are given
113     * then we send a message back to the TCP which originated the
114     * segment ti, and discard the mbuf containing it and any other
115     * attached mbufs.
116     *
117     * In any case the ack and sequence number of the transmitted
118     * segment are as specified by the parameters.
119     */
120     void
121     tcp_respond(tp, ti, m, ack, seq, flags)
122     struct tcpcb *tp;
123     register struct tcpiphdr *ti;
124     register struct mbuf *m;
125     tcp_seq ack, seq;
126     int flags;
127     {
128     register int tlen;
129     int win = 0;
130    
131     DEBUG_CALL("tcp_respond");
132     DEBUG_ARG("tp = %lx", (long)tp);
133     DEBUG_ARG("ti = %lx", (long)ti);
134     DEBUG_ARG("m = %lx", (long)m);
135     DEBUG_ARG("ack = %u", ack);
136     DEBUG_ARG("seq = %u", seq);
137     DEBUG_ARG("flags = %x", flags);
138    
139     if (tp)
140     win = sbspace(&tp->t_socket->so_rcv);
141     if (m == 0) {
142     if ((m = m_get()) == NULL)
143     return;
144     #ifdef TCP_COMPAT_42
145     tlen = 1;
146     #else
147     tlen = 0;
148     #endif
149     m->m_data += if_maxlinkhdr;
150     *mtod(m, struct tcpiphdr *) = *ti;
151     ti = mtod(m, struct tcpiphdr *);
152     flags = TH_ACK;
153     } else {
154     /*
155     * ti points into m so the next line is just making
156     * the mbuf point to ti
157     */
158     m->m_data = (caddr_t)ti;
159    
160     m->m_len = sizeof (struct tcpiphdr);
161     tlen = 0;
162     #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
163     xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, u_int32_t);
164     xchg(ti->ti_dport, ti->ti_sport, u_int16_t);
165     #undef xchg
166     }
167     ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen));
168     tlen += sizeof (struct tcpiphdr);
169     m->m_len = tlen;
170    
171     ti->ti_next = ti->ti_prev = 0;
172     ti->ti_x1 = 0;
173     ti->ti_seq = htonl(seq);
174     ti->ti_ack = htonl(ack);
175     ti->ti_x2 = 0;
176     ti->ti_off = sizeof (struct tcphdr) >> 2;
177     ti->ti_flags = flags;
178     if (tp)
179     ti->ti_win = htons((u_int16_t) (win >> tp->rcv_scale));
180     else
181     ti->ti_win = htons((u_int16_t)win);
182     ti->ti_urp = 0;
183     ti->ti_sum = 0;
184     ti->ti_sum = cksum(m, tlen);
185     ((struct ip *)ti)->ip_len = tlen;
186    
187     if(flags & TH_RST)
188     ((struct ip *)ti)->ip_ttl = MAXTTL;
189     else
190     ((struct ip *)ti)->ip_ttl = ip_defttl;
191    
192     (void) ip_output((struct socket *)0, m);
193     }
194    
195     /*
196     * Create a new TCP control block, making an
197     * empty reassembly queue and hooking it to the argument
198     * protocol control block.
199     */
200     struct tcpcb *
201     tcp_newtcpcb(so)
202     struct socket *so;
203     {
204     register struct tcpcb *tp;
205    
206     tp = (struct tcpcb *)malloc(sizeof(*tp));
207     if (tp == NULL)
208     return ((struct tcpcb *)0);
209    
210     memset((char *) tp, 0, sizeof(struct tcpcb));
211     tp->seg_next = tp->seg_prev = (tcpiphdrp_32)tp;
212     tp->t_maxseg = tcp_mssdflt;
213    
214     tp->t_flags = tcp_do_rfc1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0;
215     tp->t_socket = so;
216    
217     /*
218     * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
219     * rtt estimate. Set rttvar so that srtt + 2 * rttvar gives
220     * reasonable initial retransmit time.
221     */
222     tp->t_srtt = TCPTV_SRTTBASE;
223     tp->t_rttvar = tcp_rttdflt * PR_SLOWHZ << 2;
224     tp->t_rttmin = TCPTV_MIN;
225    
226     TCPT_RANGESET(tp->t_rxtcur,
227     ((TCPTV_SRTTBASE >> 2) + (TCPTV_SRTTDFLT << 2)) >> 1,
228     TCPTV_MIN, TCPTV_REXMTMAX);
229    
230     tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
231     tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
232     tp->t_state = TCPS_CLOSED;
233    
234     so->so_tcpcb = tp;
235    
236     return (tp);
237     }
238    
239     /*
240     * Drop a TCP connection, reporting
241     * the specified error. If connection is synchronized,
242     * then send a RST to peer.
243     */
244     struct tcpcb *tcp_drop(struct tcpcb *tp, int err)
245     {
246     /* tcp_drop(tp, errno)
247     register struct tcpcb *tp;
248     int errno;
249     {
250     */
251    
252     DEBUG_CALL("tcp_drop");
253     DEBUG_ARG("tp = %lx", (long)tp);
254     DEBUG_ARG("errno = %d", errno);
255    
256     if (TCPS_HAVERCVDSYN(tp->t_state)) {
257     tp->t_state = TCPS_CLOSED;
258     (void) tcp_output(tp);
259     tcpstat.tcps_drops++;
260     } else
261     tcpstat.tcps_conndrops++;
262     /* if (errno == ETIMEDOUT && tp->t_softerror)
263     * errno = tp->t_softerror;
264     */
265     /* so->so_error = errno; */
266     return (tcp_close(tp));
267     }
268    
269     /*
270     * Close a TCP control block:
271     * discard all space held by the tcp
272     * discard internet protocol block
273     * wake up any sleepers
274     */
275     struct tcpcb *
276     tcp_close(tp)
277     register struct tcpcb *tp;
278     {
279     register struct tcpiphdr *t;
280     struct socket *so = tp->t_socket;
281     register struct mbuf *m;
282    
283     DEBUG_CALL("tcp_close");
284     DEBUG_ARG("tp = %lx", (long )tp);
285    
286     /* free the reassembly queue, if any */
287     t = (struct tcpiphdr *) tp->seg_next;
288     while (t != (struct tcpiphdr *)tp) {
289     t = (struct tcpiphdr *)t->ti_next;
290     m = (struct mbuf *) REASS_MBUF((struct tcpiphdr *)t->ti_prev);
291     remque_32((struct tcpiphdr *) t->ti_prev);
292     m_freem(m);
293     }
294     /* It's static */
295     /* if (tp->t_template)
296     * (void) m_free(dtom(tp->t_template));
297     */
298     /* free(tp, M_PCB); */
299     free(tp);
300     so->so_tcpcb = 0;
301     soisfdisconnected(so);
302     /* clobber input socket cache if we're closing the cached connection */
303     if (so == tcp_last_so)
304     tcp_last_so = &tcb;
305     closesocket(so->s);
306     sbfree(&so->so_rcv);
307     sbfree(&so->so_snd);
308     sofree(so);
309     tcpstat.tcps_closed++;
310     return ((struct tcpcb *)0);
311     }
312    
313     void
314     tcp_drain()
315     {
316     /* XXX */
317     }
318    
319     /*
320     * When a source quench is received, close congestion window
321     * to one segment. We will gradually open it again as we proceed.
322     */
323    
324     #ifdef notdef
325    
326     void
327     tcp_quench(i, errno)
328    
329     int errno;
330     {
331     struct tcpcb *tp = intotcpcb(inp);
332    
333     if (tp)
334     tp->snd_cwnd = tp->t_maxseg;
335     }
336    
337     #endif /* notdef */
338    
339     /*
340     * TCP protocol interface to socket abstraction.
341     */
342    
343     /*
344     * User issued close, and wish to trail through shutdown states:
345     * if never received SYN, just forget it. If got a SYN from peer,
346     * but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
347     * If already got a FIN from peer, then almost done; go to LAST_ACK
348     * state. In all other cases, have already sent FIN to peer (e.g.
349     * after PRU_SHUTDOWN), and just have to play tedious game waiting
350     * for peer to send FIN or not respond to keep-alives, etc.
351     * We can let the user exit from the close as soon as the FIN is acked.
352     */
353     void
354     tcp_sockclosed(tp)
355     struct tcpcb *tp;
356     {
357    
358     DEBUG_CALL("tcp_sockclosed");
359     DEBUG_ARG("tp = %lx", (long)tp);
360    
361     switch (tp->t_state) {
362    
363     case TCPS_CLOSED:
364     case TCPS_LISTEN:
365     case TCPS_SYN_SENT:
366     tp->t_state = TCPS_CLOSED;
367     tp = tcp_close(tp);
368     break;
369    
370     case TCPS_SYN_RECEIVED:
371     case TCPS_ESTABLISHED:
372     tp->t_state = TCPS_FIN_WAIT_1;
373     break;
374    
375     case TCPS_CLOSE_WAIT:
376     tp->t_state = TCPS_LAST_ACK;
377     break;
378     }
379     /* soisfdisconnecting(tp->t_socket); */
380     if (tp && tp->t_state >= TCPS_FIN_WAIT_2)
381     soisfdisconnected(tp->t_socket);
382     if (tp)
383     tcp_output(tp);
384     }
385    
386     /*
387     * Connect to a host on the Internet
388     * Called by tcp_input
389     * Only do a connect, the tcp fields will be set in tcp_input
390     * return 0 if there's a result of the connect,
391     * else return -1 means we're still connecting
392     * The return value is almost always -1 since the socket is
393     * nonblocking. Connect returns after the SYN is sent, and does
394     * not wait for ACK+SYN.
395     */
396     int tcp_fconnect(so)
397     struct socket *so;
398     {
399     int ret=0;
400    
401     DEBUG_CALL("tcp_fconnect");
402     DEBUG_ARG("so = %lx", (long )so);
403    
404     if( (ret=so->s=socket(AF_INET,SOCK_STREAM,0)) >= 0) {
405     int opt, s=so->s;
406     struct sockaddr_in addr;
407    
408     fd_nonblock(s);
409     opt = 1;
410     setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(opt ));
411     opt = 1;
412     setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(opt ));
413    
414     addr.sin_family = AF_INET;
415     if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) {
416     /* It's an alias */
417     switch(ntohl(so->so_faddr.s_addr) & 0xff) {
418     case CTL_DNS:
419     addr.sin_addr = dns_addr;
420     break;
421     case CTL_ALIAS:
422     default:
423     addr.sin_addr = loopback_addr;
424     break;
425     }
426     } else
427     addr.sin_addr = so->so_faddr;
428     addr.sin_port = so->so_fport;
429    
430     DEBUG_MISC((dfd, " connect()ing, addr.sin_port=%d, "
431     "addr.sin_addr.s_addr=%.16s\n",
432     ntohs(addr.sin_port), inet_ntoa(addr.sin_addr)));
433     /* We don't care what port we get */
434     ret = connect(s,(struct sockaddr *)&addr,sizeof (addr));
435    
436     /*
437     * If it's not in progress, it failed, so we just return 0,
438     * without clearing SS_NOFDREF
439     */
440     soisfconnecting(so);
441     }
442    
443     return(ret);
444     }
445    
446     /*
447     * Accept the socket and connect to the local-host
448     *
449     * We have a problem. The correct thing to do would be
450     * to first connect to the local-host, and only if the
451     * connection is accepted, then do an accept() here.
452     * But, a) we need to know who's trying to connect
453     * to the socket to be able to SYN the local-host, and
454     * b) we are already connected to the foreign host by
455     * the time it gets to accept(), so... We simply accept
456     * here and SYN the local-host.
457     */
458     void
459     tcp_connect(inso)
460     struct socket *inso;
461     {
462     struct socket *so;
463     struct sockaddr_in addr;
464 cebix 1.2 socklen_t addrlen = sizeof(struct sockaddr_in);
465 gbeauche 1.1 struct tcpcb *tp;
466     int s, opt;
467    
468     DEBUG_CALL("tcp_connect");
469     DEBUG_ARG("inso = %lx", (long)inso);
470    
471     /*
472     * If it's an SS_ACCEPTONCE socket, no need to socreate()
473     * another socket, just use the accept() socket.
474     */
475     if (inso->so_state & SS_FACCEPTONCE) {
476     /* FACCEPTONCE already have a tcpcb */
477     so = inso;
478     } else {
479     if ((so = socreate()) == NULL) {
480     /* If it failed, get rid of the pending connection */
481     closesocket(accept(inso->s,(struct sockaddr *)&addr,&addrlen));
482     return;
483     }
484     if (tcp_attach(so) < 0) {
485     free(so); /* NOT sofree */
486     return;
487     }
488     so->so_laddr = inso->so_laddr;
489     so->so_lport = inso->so_lport;
490     }
491    
492     (void) tcp_mss(sototcpcb(so), 0);
493    
494     if ((s = accept(inso->s,(struct sockaddr *)&addr,&addrlen)) < 0) {
495     tcp_close(sototcpcb(so)); /* This will sofree() as well */
496     return;
497     }
498     fd_nonblock(s);
499     opt = 1;
500     setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
501     opt = 1;
502     setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
503    
504     so->so_fport = addr.sin_port;
505     so->so_faddr = addr.sin_addr;
506     /* Translate connections from localhost to the real hostname */
507     if (so->so_faddr.s_addr == 0 || so->so_faddr.s_addr == loopback_addr.s_addr)
508     so->so_faddr = our_addr;
509    
510     /* Close the accept() socket, set right state */
511     if (inso->so_state & SS_FACCEPTONCE) {
512     closesocket(so->s); /* If we only accept once, close the accept() socket */
513     so->so_state = SS_NOFDREF; /* Don't select it yet, even though we have an FD */
514     /* if it's not FACCEPTONCE, it's already NOFDREF */
515     }
516     so->s = s;
517    
518     so->so_iptos = tcp_tos(so);
519     tp = sototcpcb(so);
520    
521     tcp_template(tp);
522    
523     /* Compute window scaling to request. */
524     /* while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
525     * (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
526     * tp->request_r_scale++;
527     */
528    
529     /* soisconnecting(so); */ /* NOFDREF used instead */
530     tcpstat.tcps_connattempt++;
531    
532     tp->t_state = TCPS_SYN_SENT;
533     tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
534     tp->iss = tcp_iss;
535     tcp_iss += TCP_ISSINCR/2;
536     tcp_sendseqinit(tp);
537     tcp_output(tp);
538     }
539    
540     /*
541     * Attach a TCPCB to a socket.
542     */
543     int
544     tcp_attach(so)
545     struct socket *so;
546     {
547     if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
548     return -1;
549    
550     insque(so, &tcb);
551    
552     return 0;
553     }
554    
555     /*
556     * Set the socket's type of service field
557     */
558     struct tos_t tcptos[] = {
559     {0, 20, IPTOS_THROUGHPUT, 0}, /* ftp data */
560     {21, 21, IPTOS_LOWDELAY, EMU_FTP}, /* ftp control */
561     {0, 23, IPTOS_LOWDELAY, 0}, /* telnet */
562     {0, 80, IPTOS_THROUGHPUT, 0}, /* WWW */
563     {0, 513, IPTOS_LOWDELAY, EMU_RLOGIN|EMU_NOCONNECT}, /* rlogin */
564     {0, 514, IPTOS_LOWDELAY, EMU_RSH|EMU_NOCONNECT}, /* shell */
565     {0, 544, IPTOS_LOWDELAY, EMU_KSH}, /* kshell */
566     {0, 543, IPTOS_LOWDELAY, 0}, /* klogin */
567     {0, 6667, IPTOS_THROUGHPUT, EMU_IRC}, /* IRC */
568     {0, 6668, IPTOS_THROUGHPUT, EMU_IRC}, /* IRC undernet */
569     {0, 7070, IPTOS_LOWDELAY, EMU_REALAUDIO }, /* RealAudio control */
570     {0, 113, IPTOS_LOWDELAY, EMU_IDENT }, /* identd protocol */
571     {0, 0, 0, 0}
572     };
573    
574     struct emu_t *tcpemu = 0;
575    
576     /*
577     * Return TOS according to the above table
578     */
579     u_int8_t
580     tcp_tos(so)
581     struct socket *so;
582     {
583     int i = 0;
584     struct emu_t *emup;
585    
586     while(tcptos[i].tos) {
587     if ((tcptos[i].fport && (ntohs(so->so_fport) == tcptos[i].fport)) ||
588     (tcptos[i].lport && (ntohs(so->so_lport) == tcptos[i].lport))) {
589     so->so_emu = tcptos[i].emu;
590     return tcptos[i].tos;
591     }
592     i++;
593     }
594    
595     /* Nope, lets see if there's a user-added one */
596     for (emup = tcpemu; emup; emup = emup->next) {
597     if ((emup->fport && (ntohs(so->so_fport) == emup->fport)) ||
598     (emup->lport && (ntohs(so->so_lport) == emup->lport))) {
599     so->so_emu = emup->emu;
600     return emup->tos;
601     }
602     }
603    
604     return 0;
605     }
606    
607     int do_echo = -1;
608    
609     /*
610     * Emulate programs that try and connect to us
611     * This includes ftp (the data connection is
612     * initiated by the server) and IRC (DCC CHAT and
613     * DCC SEND) for now
614     *
615     * NOTE: It's possible to crash SLiRP by sending it
616     * unstandard strings to emulate... if this is a problem,
617     * more checks are needed here
618     *
619     * XXX Assumes the whole command came in one packet
620     *
621     * XXX Some ftp clients will have their TOS set to
622     * LOWDELAY and so Nagel will kick in. Because of this,
623     * we'll get the first letter, followed by the rest, so
624     * we simply scan for ORT instead of PORT...
625     * DCC doesn't have this problem because there's other stuff
626     * in the packet before the DCC command.
627     *
628     * Return 1 if the mbuf m is still valid and should be
629     * sbappend()ed
630     *
631     * NOTE: if you return 0 you MUST m_free() the mbuf!
632     */
633     int
634     tcp_emu(so, m)
635     struct socket *so;
636     struct mbuf *m;
637     {
638     u_int n1, n2, n3, n4, n5, n6;
639     char buff[256];
640     u_int32_t laddr;
641     u_int lport;
642     char *bptr;
643    
644     DEBUG_CALL("tcp_emu");
645     DEBUG_ARG("so = %lx", (long)so);
646     DEBUG_ARG("m = %lx", (long)m);
647    
648     switch(so->so_emu) {
649     int x, i;
650    
651     case EMU_IDENT:
652     /*
653     * Identification protocol as per rfc-1413
654     */
655    
656     {
657     struct socket *tmpso;
658     struct sockaddr_in addr;
659 cebix 1.2 socklen_t addrlen = sizeof(struct sockaddr_in);
660 gbeauche 1.1 struct sbuf *so_rcv = &so->so_rcv;
661    
662     memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
663     so_rcv->sb_wptr += m->m_len;
664     so_rcv->sb_rptr += m->m_len;
665     m->m_data[m->m_len] = 0; /* NULL terminate */
666     if (strchr(m->m_data, '\r') || strchr(m->m_data, '\n')) {
667     if (sscanf(so_rcv->sb_data, "%d%*[ ,]%d", &n1, &n2) == 2) {
668     HTONS(n1);
669     HTONS(n2);
670     /* n2 is the one on our host */
671     for (tmpso = tcb.so_next; tmpso != &tcb; tmpso = tmpso->so_next) {
672     if (tmpso->so_laddr.s_addr == so->so_laddr.s_addr &&
673     tmpso->so_lport == n2 &&
674     tmpso->so_faddr.s_addr == so->so_faddr.s_addr &&
675     tmpso->so_fport == n1) {
676     if (getsockname(tmpso->s,
677     (struct sockaddr *)&addr, &addrlen) == 0)
678     n2 = ntohs(addr.sin_port);
679     break;
680     }
681     }
682     }
683     so_rcv->sb_cc = sprintf(so_rcv->sb_data, "%d,%d\r\n", n1, n2);
684     so_rcv->sb_rptr = so_rcv->sb_data;
685     so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
686     }
687     m_free(m);
688     return 0;
689     }
690    
691     #if 0
692     case EMU_RLOGIN:
693     /*
694     * Rlogin emulation
695     * First we accumulate all the initial option negotiation,
696     * then fork_exec() rlogin according to the options
697     */
698     {
699     int i, i2, n;
700     char *ptr;
701     char args[100];
702     char term[100];
703     struct sbuf *so_snd = &so->so_snd;
704     struct sbuf *so_rcv = &so->so_rcv;
705    
706     /* First check if they have a priveladged port, or too much data has arrived */
707     if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
708     (m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
709     memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
710     so_snd->sb_wptr += 18;
711     so_snd->sb_cc += 18;
712     tcp_sockclosed(sototcpcb(so));
713     m_free(m);
714     return 0;
715     }
716    
717     /* Append the current data */
718     memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
719     so_rcv->sb_wptr += m->m_len;
720     so_rcv->sb_rptr += m->m_len;
721     m_free(m);
722    
723     /*
724     * Check if we have all the initial options,
725     * and build argument list to rlogin while we're here
726     */
727     n = 0;
728     ptr = so_rcv->sb_data;
729     args[0] = 0;
730     term[0] = 0;
731     while (ptr < so_rcv->sb_wptr) {
732     if (*ptr++ == 0) {
733     n++;
734     if (n == 2) {
735     sprintf(args, "rlogin -l %s %s",
736     ptr, inet_ntoa(so->so_faddr));
737     } else if (n == 3) {
738     i2 = so_rcv->sb_wptr - ptr;
739     for (i = 0; i < i2; i++) {
740     if (ptr[i] == '/') {
741     ptr[i] = 0;
742     #ifdef HAVE_SETENV
743     sprintf(term, "%s", ptr);
744     #else
745     sprintf(term, "TERM=%s", ptr);
746     #endif
747     ptr[i] = '/';
748     break;
749     }
750     }
751     }
752     }
753     }
754    
755     if (n != 4)
756     return 0;
757    
758     /* We have it, set our term variable and fork_exec() */
759     #ifdef HAVE_SETENV
760     setenv("TERM", term, 1);
761     #else
762     putenv(term);
763     #endif
764     fork_exec(so, args, 2);
765     term[0] = 0;
766     so->so_emu = 0;
767    
768     /* And finally, send the client a 0 character */
769     so_snd->sb_wptr[0] = 0;
770     so_snd->sb_wptr++;
771     so_snd->sb_cc++;
772    
773     return 0;
774     }
775    
776     case EMU_RSH:
777     /*
778     * rsh emulation
779     * First we accumulate all the initial option negotiation,
780     * then rsh_exec() rsh according to the options
781     */
782     {
783     int n;
784     char *ptr;
785     char *user;
786     char *args;
787     struct sbuf *so_snd = &so->so_snd;
788     struct sbuf *so_rcv = &so->so_rcv;
789    
790     /* First check if they have a priveladged port, or too much data has arrived */
791     if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
792     (m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
793     memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
794     so_snd->sb_wptr += 18;
795     so_snd->sb_cc += 18;
796     tcp_sockclosed(sototcpcb(so));
797     m_free(m);
798     return 0;
799     }
800    
801     /* Append the current data */
802     memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
803     so_rcv->sb_wptr += m->m_len;
804     so_rcv->sb_rptr += m->m_len;
805     m_free(m);
806    
807     /*
808     * Check if we have all the initial options,
809     * and build argument list to rlogin while we're here
810     */
811     n = 0;
812     ptr = so_rcv->sb_data;
813     user="";
814     args="";
815     if (so->extra==NULL) {
816     struct socket *ns;
817     struct tcpcb* tp;
818     int port=atoi(ptr);
819     if (port <= 0) return 0;
820     if (port > 1023 || port < 512) {
821     memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
822     so_snd->sb_wptr += 18;
823     so_snd->sb_cc += 18;
824     tcp_sockclosed(sototcpcb(so));
825     return 0;
826     }
827     if ((ns=socreate()) == NULL)
828     return 0;
829     if (tcp_attach(ns)<0) {
830     free(ns);
831     return 0;
832     }
833    
834     ns->so_laddr=so->so_laddr;
835     ns->so_lport=htons(port);
836    
837     (void) tcp_mss(sototcpcb(ns), 0);
838    
839     ns->so_faddr=so->so_faddr;
840     ns->so_fport=htons(IPPORT_RESERVED-1); /* Use a fake port. */
841    
842     if (ns->so_faddr.s_addr == 0 ||
843     ns->so_faddr.s_addr == loopback_addr.s_addr)
844     ns->so_faddr = our_addr;
845    
846     ns->so_iptos = tcp_tos(ns);
847     tp = sototcpcb(ns);
848    
849     tcp_template(tp);
850    
851     /* Compute window scaling to request. */
852     /* while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
853     * (TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
854     * tp->request_r_scale++;
855     */
856    
857     /*soisfconnecting(ns);*/
858    
859     tcpstat.tcps_connattempt++;
860    
861     tp->t_state = TCPS_SYN_SENT;
862     tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
863     tp->iss = tcp_iss;
864     tcp_iss += TCP_ISSINCR/2;
865     tcp_sendseqinit(tp);
866     tcp_output(tp);
867     so->extra=ns;
868     }
869     while (ptr < so_rcv->sb_wptr) {
870     if (*ptr++ == 0) {
871     n++;
872     if (n == 2) {
873     user=ptr;
874     } else if (n == 3) {
875     args=ptr;
876     }
877     }
878     }
879    
880     if (n != 4)
881     return 0;
882    
883     rsh_exec(so,so->extra, user, inet_ntoa(so->so_faddr), args);
884     so->so_emu = 0;
885     so->extra=NULL;
886    
887     /* And finally, send the client a 0 character */
888     so_snd->sb_wptr[0] = 0;
889     so_snd->sb_wptr++;
890     so_snd->sb_cc++;
891    
892     return 0;
893     }
894    
895     case EMU_CTL:
896     {
897     int num;
898     struct sbuf *so_snd = &so->so_snd;
899     struct sbuf *so_rcv = &so->so_rcv;
900    
901     /*
902     * If there is binary data here, we save it in so->so_m
903     */
904     if (!so->so_m) {
905     int rxlen;
906     char *rxdata;
907     rxdata=mtod(m, char *);
908     for (rxlen=m->m_len; rxlen; rxlen--) {
909     if (*rxdata++ & 0x80) {
910     so->so_m = m;
911     return 0;
912     }
913     }
914     } /* if(so->so_m==NULL) */
915    
916     /*
917     * Append the line
918     */
919     sbappendsb(so_rcv, m);
920    
921     /* To avoid going over the edge of the buffer, we reset it */
922     if (so_snd->sb_cc == 0)
923     so_snd->sb_wptr = so_snd->sb_rptr = so_snd->sb_data;
924    
925     /*
926     * A bit of a hack:
927     * If the first packet we get here is 1 byte long, then it
928     * was done in telnet character mode, therefore we must echo
929     * the characters as they come. Otherwise, we echo nothing,
930     * because in linemode, the line is already echoed
931     * XXX two or more control connections won't work
932     */
933     if (do_echo == -1) {
934     if (m->m_len == 1) do_echo = 1;
935     else do_echo = 0;
936     }
937     if (do_echo) {
938     sbappendsb(so_snd, m);
939     m_free(m);
940     tcp_output(sototcpcb(so)); /* XXX */
941     } else
942     m_free(m);
943    
944     num = 0;
945     while (num < so->so_rcv.sb_cc) {
946     if (*(so->so_rcv.sb_rptr + num) == '\n' ||
947     *(so->so_rcv.sb_rptr + num) == '\r') {
948     int n;
949    
950     *(so_rcv->sb_rptr + num) = 0;
951     if (ctl_password && !ctl_password_ok) {
952     /* Need a password */
953     if (sscanf(so_rcv->sb_rptr, "pass %256s", buff) == 1) {
954     if (strcmp(buff, ctl_password) == 0) {
955     ctl_password_ok = 1;
956     n = sprintf(so_snd->sb_wptr,
957     "Password OK.\r\n");
958     goto do_prompt;
959     }
960     }
961     n = sprintf(so_snd->sb_wptr,
962     "Error: Password required, log on with \"pass PASSWORD\"\r\n");
963     goto do_prompt;
964     }
965     cfg_quitting = 0;
966     n = do_config(so_rcv->sb_rptr, so, PRN_SPRINTF);
967     if (!cfg_quitting) {
968     /* Register the printed data */
969     do_prompt:
970     so_snd->sb_cc += n;
971     so_snd->sb_wptr += n;
972     /* Add prompt */
973     n = sprintf(so_snd->sb_wptr, "Slirp> ");
974     so_snd->sb_cc += n;
975     so_snd->sb_wptr += n;
976     }
977     /* Drop so_rcv data */
978     so_rcv->sb_cc = 0;
979     so_rcv->sb_wptr = so_rcv->sb_rptr = so_rcv->sb_data;
980     tcp_output(sototcpcb(so)); /* Send the reply */
981     }
982     num++;
983     }
984     return 0;
985     }
986     #endif
987     case EMU_FTP: /* ftp */
988     *(m->m_data+m->m_len) = 0; /* NULL terminate for strstr */
989     if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
990     /*
991     * Need to emulate the PORT command
992     */
993     x = sscanf(bptr, "ORT %d,%d,%d,%d,%d,%d\r\n%256[^\177]",
994     &n1, &n2, &n3, &n4, &n5, &n6, buff);
995     if (x < 6)
996     return 1;
997    
998     laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
999     lport = htons((n5 << 8) | (n6));
1000    
1001     if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL)
1002     return 1;
1003    
1004     n6 = ntohs(so->so_fport);
1005    
1006     n5 = (n6 >> 8) & 0xff;
1007     n6 &= 0xff;
1008    
1009     laddr = ntohl(so->so_faddr.s_addr);
1010    
1011     n1 = ((laddr >> 24) & 0xff);
1012     n2 = ((laddr >> 16) & 0xff);
1013     n3 = ((laddr >> 8) & 0xff);
1014     n4 = (laddr & 0xff);
1015    
1016     m->m_len = bptr - m->m_data; /* Adjust length */
1017     m->m_len += sprintf(bptr,"ORT %d,%d,%d,%d,%d,%d\r\n%s",
1018     n1, n2, n3, n4, n5, n6, x==7?buff:"");
1019     return 1;
1020     } else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) {
1021     /*
1022     * Need to emulate the PASV response
1023     */
1024     x = sscanf(bptr, "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%256[^\177]",
1025     &n1, &n2, &n3, &n4, &n5, &n6, buff);
1026     if (x < 6)
1027     return 1;
1028    
1029     laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
1030     lport = htons((n5 << 8) | (n6));
1031    
1032     if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL)
1033     return 1;
1034    
1035     n6 = ntohs(so->so_fport);
1036    
1037     n5 = (n6 >> 8) & 0xff;
1038     n6 &= 0xff;
1039    
1040     laddr = ntohl(so->so_faddr.s_addr);
1041    
1042     n1 = ((laddr >> 24) & 0xff);
1043     n2 = ((laddr >> 16) & 0xff);
1044     n3 = ((laddr >> 8) & 0xff);
1045     n4 = (laddr & 0xff);
1046    
1047     m->m_len = bptr - m->m_data; /* Adjust length */
1048     m->m_len += sprintf(bptr,"27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s",
1049     n1, n2, n3, n4, n5, n6, x==7?buff:"");
1050    
1051     return 1;
1052     }
1053    
1054     return 1;
1055    
1056     case EMU_KSH:
1057     /*
1058     * The kshell (Kerberos rsh) and shell services both pass
1059     * a local port port number to carry signals to the server
1060     * and stderr to the client. It is passed at the beginning
1061     * of the connection as a NUL-terminated decimal ASCII string.
1062     */
1063     so->so_emu = 0;
1064     for (lport = 0, i = 0; i < m->m_len-1; ++i) {
1065     if (m->m_data[i] < '0' || m->m_data[i] > '9')
1066     return 1; /* invalid number */
1067     lport *= 10;
1068     lport += m->m_data[i] - '0';
1069     }
1070     if (m->m_data[m->m_len-1] == '\0' && lport != 0 &&
1071     (so = solisten(0, so->so_laddr.s_addr, htons(lport), SS_FACCEPTONCE)) != NULL)
1072     m->m_len = sprintf(m->m_data, "%d", ntohs(so->so_fport))+1;
1073     return 1;
1074    
1075     case EMU_IRC:
1076     /*
1077     * Need to emulate DCC CHAT, DCC SEND and DCC MOVE
1078     */
1079     *(m->m_data+m->m_len) = 0; /* NULL terminate the string for strstr */
1080     if ((bptr = (char *)strstr(m->m_data, "DCC")) == NULL)
1081     return 1;
1082    
1083     /* The %256s is for the broken mIRC */
1084     if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) {
1085     if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1086     return 1;
1087    
1088     m->m_len = bptr - m->m_data; /* Adjust length */
1089     m->m_len += sprintf(bptr, "DCC CHAT chat %lu %u%c\n",
1090     (unsigned long)ntohl(so->so_faddr.s_addr),
1091     ntohs(so->so_fport), 1);
1092     } else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
1093     if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1094     return 1;
1095    
1096     m->m_len = bptr - m->m_data; /* Adjust length */
1097     m->m_len += sprintf(bptr, "DCC SEND %s %lu %u %u%c\n",
1098     buff, (unsigned long)ntohl(so->so_faddr.s_addr),
1099     ntohs(so->so_fport), n1, 1);
1100     } else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) {
1101     if ((so = solisten(0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL)
1102     return 1;
1103    
1104     m->m_len = bptr - m->m_data; /* Adjust length */
1105     m->m_len += sprintf(bptr, "DCC MOVE %s %lu %u %u%c\n",
1106     buff, (unsigned long)ntohl(so->so_faddr.s_addr),
1107     ntohs(so->so_fport), n1, 1);
1108     }
1109     return 1;
1110    
1111     case EMU_REALAUDIO:
1112     /*
1113     * RealAudio emulation - JP. We must try to parse the incoming
1114     * data and try to find the two characters that contain the
1115     * port number. Then we redirect an udp port and replace the
1116     * number with the real port we got.
1117     *
1118     * The 1.0 beta versions of the player are not supported
1119     * any more.
1120     *
1121     * A typical packet for player version 1.0 (release version):
1122     *
1123     * 0000:50 4E 41 00 05
1124     * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 .....×..gælÜc..P
1125     * 0010:4E 43 4C 49 45 4E 54 20 31 30 31 20 41 4C 50 48 NCLIENT 101 ALPH
1126     * 0020:41 6C 00 00 52 00 17 72 61 66 69 6C 65 73 2F 76 Al..R..rafiles/v
1127     * 0030:6F 61 2F 65 6E 67 6C 69 73 68 5F 2E 72 61 79 42 oa/english_.rayB
1128     *
1129     * Now the port number 0x1BD7 is found at offset 0x04 of the
1130     * Now the port number 0x1BD7 is found at offset 0x04 of the
1131     * second packet. This time we received five bytes first and
1132     * then the rest. You never know how many bytes you get.
1133     *
1134     * A typical packet for player version 2.0 (beta):
1135     *
1136     * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA...........Á.
1137     * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .guxõc..Win2.0.0
1138     * 0020:2E 35 6C 00 00 52 00 1C 72 61 66 69 6C 65 73 2F .5l..R..rafiles/
1139     * 0030:77 65 62 73 69 74 65 2F 32 30 72 65 6C 65 61 73 website/20releas
1140     * 0040:65 2E 72 61 79 53 00 00 06 36 42 e.rayS...6B
1141     *
1142     * Port number 0x1BC1 is found at offset 0x0d.
1143     *
1144     * This is just a horrible switch statement. Variable ra tells
1145     * us where we're going.
1146     */
1147    
1148     bptr = m->m_data;
1149     while (bptr < m->m_data + m->m_len) {
1150     u_short p;
1151     static int ra = 0;
1152     char ra_tbl[4];
1153    
1154     ra_tbl[0] = 0x50;
1155     ra_tbl[1] = 0x4e;
1156     ra_tbl[2] = 0x41;
1157     ra_tbl[3] = 0;
1158    
1159     switch (ra) {
1160     case 0:
1161     case 2:
1162     case 3:
1163     if (*bptr++ != ra_tbl[ra]) {
1164     ra = 0;
1165     continue;
1166     }
1167     break;
1168    
1169     case 1:
1170     /*
1171     * We may get 0x50 several times, ignore them
1172     */
1173     if (*bptr == 0x50) {
1174     ra = 1;
1175     bptr++;
1176     continue;
1177     } else if (*bptr++ != ra_tbl[ra]) {
1178     ra = 0;
1179     continue;
1180     }
1181     break;
1182    
1183     case 4:
1184     /*
1185     * skip version number
1186     */
1187     bptr++;
1188     break;
1189    
1190     case 5:
1191     /*
1192     * The difference between versions 1.0 and
1193     * 2.0 is here. For future versions of
1194     * the player this may need to be modified.
1195     */
1196     if (*(bptr + 1) == 0x02)
1197     bptr += 8;
1198     else
1199     bptr += 4;
1200     break;
1201    
1202     case 6:
1203     /* This is the field containing the port
1204     * number that RA-player is listening to.
1205     */
1206     lport = (((u_char*)bptr)[0] << 8)
1207     + ((u_char *)bptr)[1];
1208     if (lport < 6970)
1209     lport += 256; /* don't know why */
1210     if (lport < 6970 || lport > 7170)
1211     return 1; /* failed */
1212    
1213     /* try to get udp port between 6970 - 7170 */
1214     for (p = 6970; p < 7071; p++) {
1215     if (udp_listen( htons(p),
1216     so->so_laddr.s_addr,
1217     htons(lport),
1218     SS_FACCEPTONCE)) {
1219     break;
1220     }
1221     }
1222     if (p == 7071)
1223     p = 0;
1224     *(u_char *)bptr++ = (p >> 8) & 0xff;
1225     *(u_char *)bptr++ = p & 0xff;
1226     ra = 0;
1227     return 1; /* port redirected, we're done */
1228     break;
1229    
1230     default:
1231     ra = 0;
1232     }
1233     ra++;
1234     }
1235     return 1;
1236    
1237     default:
1238     /* Ooops, not emulated, won't call tcp_emu again */
1239     so->so_emu = 0;
1240     return 1;
1241     }
1242     }
1243    
1244     /*
1245     * Do misc. config of SLiRP while its running.
1246     * Return 0 if this connections is to be closed, 1 otherwise,
1247     * return 2 if this is a command-line connection
1248     */
1249     int
1250     tcp_ctl(so)
1251     struct socket *so;
1252     {
1253     struct sbuf *sb = &so->so_snd;
1254     int command;
1255     struct ex_list *ex_ptr;
1256     int do_pty;
1257     // struct socket *tmpso;
1258    
1259     DEBUG_CALL("tcp_ctl");
1260     DEBUG_ARG("so = %lx", (long )so);
1261    
1262     #if 0
1263     /*
1264     * Check if they're authorised
1265     */
1266     if (ctl_addr.s_addr && (ctl_addr.s_addr == -1 || (so->so_laddr.s_addr != ctl_addr.s_addr))) {
1267     sb->sb_cc = sprintf(sb->sb_wptr,"Error: Permission denied.\r\n");
1268     sb->sb_wptr += sb->sb_cc;
1269     return 0;
1270     }
1271     #endif
1272     command = (ntohl(so->so_faddr.s_addr) & 0xff);
1273    
1274     switch(command) {
1275     default: /* Check for exec's */
1276    
1277     /*
1278     * Check if it's pty_exec
1279     */
1280     for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
1281     if (ex_ptr->ex_fport == so->so_fport &&
1282     command == ex_ptr->ex_addr) {
1283     do_pty = ex_ptr->ex_pty;
1284     goto do_exec;
1285     }
1286     }
1287    
1288     /*
1289     * Nothing bound..
1290     */
1291     /* tcp_fconnect(so); */
1292    
1293     /* FALLTHROUGH */
1294     case CTL_ALIAS:
1295     sb->sb_cc = sprintf(sb->sb_wptr,
1296     "Error: No application configured.\r\n");
1297     sb->sb_wptr += sb->sb_cc;
1298     return(0);
1299    
1300     do_exec:
1301     DEBUG_MISC((dfd, " executing %s \n",ex_ptr->ex_exec));
1302     return(fork_exec(so, ex_ptr->ex_exec, do_pty));
1303    
1304     #if 0
1305     case CTL_CMD:
1306     for (tmpso = tcb.so_next; tmpso != &tcb; tmpso = tmpso->so_next) {
1307     if (tmpso->so_emu == EMU_CTL &&
1308     !(tmpso->so_tcpcb?
1309     (tmpso->so_tcpcb->t_state & (TCPS_TIME_WAIT|TCPS_LAST_ACK))
1310     :0)) {
1311     /* Ooops, control connection already active */
1312     sb->sb_cc = sprintf(sb->sb_wptr,"Sorry, already connected.\r\n");
1313     sb->sb_wptr += sb->sb_cc;
1314     return 0;
1315     }
1316     }
1317     so->so_emu = EMU_CTL;
1318     ctl_password_ok = 0;
1319     sb->sb_cc = sprintf(sb->sb_wptr, "Slirp command-line ready (type \"help\" for help).\r\nSlirp> ");
1320     sb->sb_wptr += sb->sb_cc;
1321     do_echo=-1;
1322     return(2);
1323     #endif
1324     }
1325     }