xref: /netbsd-src/external/bsd/libpcap/dist/pcap-dos.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: pcap-dos.c,v 1.4 2017/01/24 22:29:28 christos Exp $	*/
2 
3 /*
4  *  This file is part of DOS-libpcap
5  *  Ported to DOS/DOSX by G. Vanem <gvanem@yahoo.no>
6  *
7  *  pcap-dos.c: Interface to PKTDRVR, NDIS2 and 32-bit pmode
8  *              network drivers.
9  */
10 
11 #include <stdio.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <signal.h>
15 #include <float.h>
16 #include <fcntl.h>
17 #include <io.h>
18 
19 #if defined(USE_32BIT_DRIVERS)
20   #include "msdos/pm_drvr/pmdrvr.h"
21   #include "msdos/pm_drvr/pci.h"
22   #include "msdos/pm_drvr/bios32.h"
23   #include "msdos/pm_drvr/module.h"
24   #include "msdos/pm_drvr/3c501.h"
25   #include "msdos/pm_drvr/3c503.h"
26   #include "msdos/pm_drvr/3c509.h"
27   #include "msdos/pm_drvr/3c59x.h"
28   #include "msdos/pm_drvr/3c515.h"
29   #include "msdos/pm_drvr/3c90x.h"
30   #include "msdos/pm_drvr/3c575_cb.h"
31   #include "msdos/pm_drvr/ne.h"
32   #include "msdos/pm_drvr/wd.h"
33   #include "msdos/pm_drvr/accton.h"
34   #include "msdos/pm_drvr/cs89x0.h"
35   #include "msdos/pm_drvr/rtl8139.h"
36   #include "msdos/pm_drvr/ne2k-pci.h"
37 #endif
38 
39 #include "pcap.h"
40 #include "pcap-dos.h"
41 #include "pcap-int.h"
42 #include "msdos/pktdrvr.h"
43 
44 #ifdef USE_NDIS2
45 #include "msdos/ndis2.h"
46 #endif
47 
48 #include <arpa/inet.h>
49 #include <net/if.h>
50 #include <net/if_arp.h>
51 #include <net/if_ether.h>
52 #include <net/if_packe.h>
53 #include <tcp.h>
54 
55 #if defined(USE_32BIT_DRIVERS)
56   #define FLUSHK()       do { _printk_safe = 1; _printk_flush(); } while (0)
57   #define NDIS_NEXT_DEV  &rtl8139_dev
58 
59   static char *rx_pool = NULL;
60   static void init_32bit (void);
61 
62   static int  pktq_init     (struct rx_ringbuf *q, int size, int num, char *pool);
63   static int  pktq_check    (struct rx_ringbuf *q);
64   static int  pktq_inc_out  (struct rx_ringbuf *q);
65   static int  pktq_in_index (struct rx_ringbuf *q) LOCKED_FUNC;
66   static void pktq_clear    (struct rx_ringbuf *q) LOCKED_FUNC;
67 
68   static struct rx_elem *pktq_in_elem  (struct rx_ringbuf *q) LOCKED_FUNC;
69   static struct rx_elem *pktq_out_elem (struct rx_ringbuf *q);
70 
71 #else
72   #define FLUSHK()      ((void)0)
73   #define NDIS_NEXT_DEV  NULL
74 #endif
75 
76 /*
77  * Internal variables/functions in Watt-32
78  */
79 extern WORD  _pktdevclass;
80 extern BOOL  _eth_is_init;
81 extern int   _w32_dynamic_host;
82 extern int   _watt_do_exit;
83 extern int   _watt_is_init;
84 extern int   _w32__bootp_on, _w32__dhcp_on, _w32__rarp_on, _w32__do_mask_req;
85 extern void (*_w32_usr_post_init) (void);
86 extern void (*_w32_print_hook)();
87 
88 extern void dbug_write (const char *);  /* Watt-32 lib, pcdbug.c */
89 extern int  pkt_get_mtu (void);
90 
91 static int ref_count = 0;
92 
93 static u_long mac_count    = 0;
94 static u_long filter_count = 0;
95 
96 static volatile BOOL exc_occured = 0;
97 
98 static struct device *handle_to_device [20];
99 
100 static int  pcap_activate_dos (pcap_t *p);
101 static int  pcap_read_dos (pcap_t *p, int cnt, pcap_handler callback,
102                            u_char *data);
103 static void pcap_cleanup_dos (pcap_t *p);
104 static int  pcap_stats_dos (pcap_t *p, struct pcap_stat *ps);
105 static int  pcap_sendpacket_dos (pcap_t *p, const void *buf, size_t len);
106 static int  pcap_setfilter_dos (pcap_t *p, struct bpf_program *fp);
107 
108 static int  ndis_probe (struct device *dev);
109 static int  pkt_probe  (struct device *dev);
110 
111 static void close_driver (void);
112 static int  init_watt32 (struct pcap *pcap, const char *dev_name, char *err_buf);
113 static int  first_init (const char *name, char *ebuf, int promisc);
114 
115 static void watt32_recv_hook (u_char *dummy, const struct pcap_pkthdr *pcap,
116                               const u_char *buf);
117 
118 /*
119  * These are the device we always support
120  */
121 static struct device ndis_dev = {
122               "ndis",
123               "NDIS2 LanManager",
124               0,
125               0,0,0,0,0,0,
126               NDIS_NEXT_DEV,  /* NULL or a 32-bit device */
127               ndis_probe
128             };
129 
130 static struct device pkt_dev = {
131               "pkt",
132               "Packet-Driver",
133               0,
134               0,0,0,0,0,0,
135               &ndis_dev,
136               pkt_probe
137             };
138 
139 static struct device *get_device (int fd)
140 {
141   if (fd <= 0 || fd >= sizeof(handle_to_device)/sizeof(handle_to_device[0]))
142      return (NULL);
143   return handle_to_device [fd-1];
144 }
145 
146 /*
147  * Private data for capturing on MS-DOS.
148  */
149 struct pcap_dos {
150 	void (*wait_proc)(void); /* call proc while waiting */
151 	struct pcap_stat stat;
152 };
153 
154 pcap_t *pcap_create_interface (const char *device _U_, char *ebuf)
155 {
156 	pcap_t *p;
157 
158 	p = pcap_create_common(ebuf, sizeof (struct pcap_dos));
159 	if (p == NULL)
160 		return (NULL);
161 
162 	p->activate_op = pcap_activate_dos;
163 	return (p);
164 }
165 
166 /*
167  * Open MAC-driver with name 'device_name' for live capture of
168  * network packets.
169  */
170 static int pcap_activate_dos (pcap_t *pcap)
171 {
172   if (pcap->opt.rfmon) {
173     /*
174      * No monitor mode on DOS.
175      */
176     return (PCAP_ERROR_RFMON_NOTSUP);
177   }
178 
179   if (pcap->snapshot < ETH_MIN+8)
180       pcap->snapshot = ETH_MIN+8;
181 
182   if (pcap->snapshot > ETH_MAX)   /* silently accept and truncate large MTUs */
183       pcap->snapshot = ETH_MAX;
184 
185   pcap->linktype          = DLT_EN10MB;  /* !! */
186   pcap->cleanup_op        = pcap_cleanup_dos;
187   pcap->read_op           = pcap_read_dos;
188   pcap->stats_op          = pcap_stats_dos;
189   pcap->inject_op         = pcap_sendpacket_dos;
190   pcap->setfilter_op      = pcap_setfilter_dos;
191   pcap->setdirection_op   = NULL;  /* Not implemented.*/
192   pcap->fd                = ++ref_count;
193 
194   pcap->bufsize = ETH_MAX+100;     /* add some margin */
195   pcap->buffer = calloc (pcap->bufsize, 1);
196 
197   if (pcap->fd == 1)  /* first time we're called */
198   {
199     if (!init_watt32(pcap, pcap->opt.device, pcap->errbuf) ||
200         !first_init(pcap->opt.device, pcap->errbuf, pcap->opt.promisc))
201     {
202       return (PCAP_ERROR);
203     }
204     atexit (close_driver);
205   }
206   else if (stricmp(active_dev->name,pcap->opt.device))
207   {
208     pcap_snprintf (pcap->errbuf, PCAP_ERRBUF_SIZE,
209                    "Cannot use different devices simultaneously "
210                    "(`%s' vs. `%s')", active_dev->name, pcap->opt.device);
211     return (PCAP_ERROR);
212   }
213   handle_to_device [pcap->fd-1] = active_dev;
214   return (0);
215 }
216 
217 /*
218  * Poll the receiver queue and call the pcap callback-handler
219  * with the packet.
220  */
221 static int
222 pcap_read_one (pcap_t *p, pcap_handler callback, u_char *data)
223 {
224   struct pcap_dos *pd = p->priv;
225   struct pcap_pkthdr pcap;
226   struct timeval     now, expiry = { 0,0 };
227   int    rx_len = 0;
228 
229   if (p->opt.timeout > 0)
230   {
231     gettimeofday2 (&now, NULL);
232     expiry.tv_usec = now.tv_usec + 1000UL * p->opt.timeout;
233     expiry.tv_sec  = now.tv_sec;
234     while (expiry.tv_usec >= 1000000L)
235     {
236       expiry.tv_usec -= 1000000L;
237       expiry.tv_sec++;
238     }
239   }
240 
241   while (!exc_occured)
242   {
243     volatile struct device *dev; /* might be reset by sig_handler */
244 
245     dev = get_device (p->fd);
246     if (!dev)
247        break;
248 
249     PCAP_ASSERT (dev->copy_rx_buf || dev->peek_rx_buf);
250     FLUSHK();
251 
252     /* If driver has a zero-copy receive facility, peek at the queue,
253      * filter it, do the callback and release the buffer.
254      */
255     if (dev->peek_rx_buf)
256     {
257       PCAP_ASSERT (dev->release_rx_buf);
258       rx_len = (*dev->peek_rx_buf) (&p->buffer);
259     }
260     else
261     {
262       rx_len = (*dev->copy_rx_buf) (p->buffer, p->snapshot);
263     }
264 
265     if (rx_len > 0)  /* got a packet */
266     {
267       mac_count++;
268 
269       FLUSHK();
270 
271       pcap.caplen = min (rx_len, p->snapshot);
272       pcap.len    = rx_len;
273 
274       if (callback &&
275           (!p->fcode.bf_insns || bpf_filter(p->fcode.bf_insns, p->buffer, pcap.len, pcap.caplen)))
276       {
277         filter_count++;
278 
279         /* Fix-me!! Should be time of arrival. Not time of
280          * capture.
281          */
282         gettimeofday2 (&pcap.ts, NULL);
283         (*callback) (data, &pcap, p->buffer);
284       }
285 
286       if (dev->release_rx_buf)
287         (*dev->release_rx_buf) (p->buffer);
288 
289       if (pcap_pkt_debug > 0)
290       {
291         if (callback == watt32_recv_hook)
292              dbug_write ("pcap_recv_hook\n");
293         else dbug_write ("pcap_read_op\n");
294       }
295       FLUSHK();
296       return (1);
297     }
298 
299     /* Has "pcap_breakloop()" been called?
300      */
301     if (p->break_loop) {
302       /*
303        * Yes - clear the flag that indicates that it
304        * has, and return -2 to indicate that we were
305        * told to break out of the loop.
306        */
307       p->break_loop = 0;
308       return (-2);
309     }
310 
311     /* If not to wait for a packet or pcap_cleanup_dos() called from
312      * e.g. SIGINT handler, exit loop now.
313      */
314     if (p->opt.timeout <= 0 || (volatile int)p->fd <= 0)
315        break;
316 
317     gettimeofday2 (&now, NULL);
318 
319     if (timercmp(&now, &expiry, >))
320        break;
321 
322 #ifndef DJGPP
323     kbhit();    /* a real CPU hog */
324 #endif
325 
326     if (pd->wait_proc)
327       (*pd->wait_proc)();     /* call yield func */
328   }
329 
330   if (rx_len < 0)            /* receive error */
331   {
332     pd->stat.ps_drop++;
333 #ifdef USE_32BIT_DRIVERS
334     if (pcap_pkt_debug > 1)
335        printk ("pkt-err %s\n", pktInfo.error);
336 #endif
337     return (-1);
338   }
339   return (0);
340 }
341 
342 static int
343 pcap_read_dos (pcap_t *p, int cnt, pcap_handler callback, u_char *data)
344 {
345   int rc, num = 0;
346 
347   while (num <= cnt || PACKET_COUNT_IS_UNLIMITED(cnt))
348   {
349     if (p->fd <= 0)
350        return (-1);
351     rc = pcap_read_one (p, callback, data);
352     if (rc > 0)
353        num++;
354     if (rc < 0)
355        break;
356     _w32_os_yield();  /* allow SIGINT generation, yield to Win95/NT */
357   }
358   return (num);
359 }
360 
361 /*
362  * Return network statistics
363  */
364 static int pcap_stats_dos (pcap_t *p, struct pcap_stat *ps)
365 {
366   struct net_device_stats *stats;
367   struct pcap_dos         *pd;
368   struct device           *dev = p ? get_device(p->fd) : NULL;
369 
370   if (!dev)
371   {
372     strcpy (p->errbuf, "illegal pcap handle");
373     return (-1);
374   }
375 
376   if (!dev->get_stats || (stats = (*dev->get_stats)(dev)) == NULL)
377   {
378     strcpy (p->errbuf, "device statistics not available");
379     return (-1);
380   }
381 
382   FLUSHK();
383 
384   pd = p->priv;
385   pd->stat.ps_recv   = stats->rx_packets;
386   pd->stat.ps_drop  += stats->rx_missed_errors;
387   pd->stat.ps_ifdrop = stats->rx_dropped +  /* queue full */
388                          stats->rx_errors;    /* HW errors */
389   if (ps)
390      *ps = pd->stat;
391 
392   return (0);
393 }
394 
395 /*
396  * Return detailed network/device statistics.
397  * May be called after 'dev->close' is called.
398  */
399 int pcap_stats_ex (pcap_t *p, struct pcap_stat_ex *se)
400 {
401   struct device *dev = p ? get_device (p->fd) : NULL;
402 
403   if (!dev || !dev->get_stats)
404   {
405     strlcpy (p->errbuf, "detailed device statistics not available",
406              PCAP_ERRBUF_SIZE);
407     return (-1);
408   }
409 
410   if (!strnicmp(dev->name,"pkt",3))
411   {
412     strlcpy (p->errbuf, "pktdrvr doesn't have detailed statistics",
413              PCAP_ERRBUF_SIZE);
414     return (-1);
415   }
416   memcpy (se, (*dev->get_stats)(dev), sizeof(*se));
417   return (0);
418 }
419 
420 /*
421  * Simply store the filter-code for the pcap_read_dos() callback
422  * Some day the filter-code could be handed down to the active
423  * device (pkt_rx1.s or 32-bit device interrupt handler).
424  */
425 static int pcap_setfilter_dos (pcap_t *p, struct bpf_program *fp)
426 {
427   if (!p)
428      return (-1);
429   p->fcode = *fp;
430   return (0);
431 }
432 
433 /*
434  * Return # of packets received in pcap_read_dos()
435  */
436 u_long pcap_mac_packets (void)
437 {
438   return (mac_count);
439 }
440 
441 /*
442  * Return # of packets passed through filter in pcap_read_dos()
443  */
444 u_long pcap_filter_packets (void)
445 {
446   return (filter_count);
447 }
448 
449 /*
450  * Close pcap device. Not called for offline captures.
451  */
452 static void pcap_cleanup_dos (pcap_t *p)
453 {
454   struct pcap_dos *pd;
455 
456   if (!exc_occured)
457   {
458     pd = p->priv;
459     if (pcap_stats(p,NULL) < 0)
460        pd->stat.ps_drop = 0;
461     if (!get_device(p->fd))
462        return;
463 
464     handle_to_device [p->fd-1] = NULL;
465     p->fd = 0;
466     if (ref_count > 0)
467         ref_count--;
468     if (ref_count > 0)
469        return;
470   }
471   close_driver();
472 }
473 
474 /*
475  * Return the name of the 1st network interface,
476  * or NULL if none can be found.
477  */
478 char *pcap_lookupdev (char *ebuf)
479 {
480   struct device *dev;
481 
482 #ifdef USE_32BIT_DRIVERS
483   init_32bit();
484 #endif
485 
486   for (dev = (struct device*)dev_base; dev; dev = dev->next)
487   {
488     PCAP_ASSERT (dev->probe);
489 
490     if ((*dev->probe)(dev))
491     {
492       FLUSHK();
493       probed_dev = (struct device*) dev; /* remember last probed device */
494       return (char*) dev->name;
495     }
496   }
497 
498   if (ebuf)
499      strcpy (ebuf, "No driver found");
500   return (NULL);
501 }
502 
503 /*
504  * Gets localnet & netmask from Watt-32.
505  */
506 int pcap_lookupnet (const char *device, bpf_u_int32 *localnet,
507                     bpf_u_int32 *netmask, char *errbuf)
508 {
509   DWORD mask, net;
510 
511   if (!_watt_is_init)
512   {
513     strcpy (errbuf, "pcap_open_offline() or pcap_activate() must be "
514                     "called first");
515     return (-1);
516   }
517 
518   mask  = _w32_sin_mask;
519   net = my_ip_addr & mask;
520   if (net == 0)
521   {
522     if (IN_CLASSA(*netmask))
523        net = IN_CLASSA_NET;
524     else if (IN_CLASSB(*netmask))
525        net = IN_CLASSB_NET;
526     else if (IN_CLASSC(*netmask))
527        net = IN_CLASSC_NET;
528     else
529     {
530       pcap_snprintf (errbuf, PCAP_ERRBUF_SIZE, "inet class for 0x%lx unknown", mask);
531       return (-1);
532     }
533   }
534   *localnet = htonl (net);
535   *netmask = htonl (mask);
536 
537   ARGSUSED (device);
538   return (0);
539 }
540 
541 /*
542  * Get a list of all interfaces that are present and that we probe okay.
543  * Returns -1 on error, 0 otherwise.
544  * The list, as returned through "alldevsp", may be NULL if no interfaces
545  * were up and could be opened.
546  */
547 int pcap_platform_finddevs  (pcap_if_t **alldevsp, char *errbuf)
548 {
549   struct device     *dev;
550   struct sockaddr_in sa_ll_1, sa_ll_2;
551   struct sockaddr   *addr, *netmask, *broadaddr, *dstaddr;
552   pcap_if_t *devlist = NULL;
553   int       ret = 0;
554   size_t    addr_size = sizeof(*addr);
555 
556   for (dev = (struct device*)dev_base; dev; dev = dev->next)
557   {
558     PCAP_ASSERT (dev->probe);
559 
560     if (!(*dev->probe)(dev))
561        continue;
562 
563     PCAP_ASSERT (dev->close);  /* set by probe routine */
564     FLUSHK();
565     (*dev->close) (dev);
566 
567     memset (&sa_ll_1, 0, sizeof(sa_ll_1));
568     memset (&sa_ll_2, 0, sizeof(sa_ll_2));
569     sa_ll_1.sin_family = AF_INET;
570     sa_ll_2.sin_family = AF_INET;
571 
572     addr      = (struct sockaddr*) &sa_ll_1;
573     netmask   = (struct sockaddr*) &sa_ll_1;
574     dstaddr   = (struct sockaddr*) &sa_ll_1;
575     broadaddr = (struct sockaddr*) &sa_ll_2;
576     memset (&sa_ll_2.sin_addr, 0xFF, sizeof(sa_ll_2.sin_addr));
577 
578     if (pcap_add_if(&devlist, dev->name, dev->flags,
579                     dev->long_name, errbuf) < 0)
580     {
581       ret = -1;
582       break;
583     }
584 #if 0   /* Pkt drivers should have no addresses */
585     if (add_addr_to_iflist(&devlist, dev->name, dev->flags, addr, addr_size,
586                            netmask, addr_size, broadaddr, addr_size,
587                            dstaddr, addr_size, errbuf) < 0)
588     {
589       ret = -1;
590       break;
591     }
592 #endif
593   }
594 
595   if (devlist && ret < 0)
596   {
597     pcap_freealldevs (devlist);
598     devlist = NULL;
599   }
600   else
601   if (!devlist)
602      strcpy (errbuf, "No drivers found");
603 
604   *alldevsp = devlist;
605   return (ret);
606 }
607 
608 /*
609  * pcap_assert() is mainly used for debugging
610  */
611 void pcap_assert (const char *what, const char *file, unsigned line)
612 {
613   FLUSHK();
614   fprintf (stderr, "%s (%u): Assertion \"%s\" failed\n",
615            file, line, what);
616   close_driver();
617   _exit (-1);
618 }
619 
620 /*
621  * For pcap_offline_read(): wait and yield between printing packets
622  * to simulate the pace packets where actually recorded.
623  */
624 void pcap_set_wait (pcap_t *p, void (*yield)(void), int wait)
625 {
626   if (p)
627   {
628     struct pcap_dos *pd = p->priv;
629 
630     pd->wait_proc  = yield;
631     p->opt.timeout = wait;
632   }
633 }
634 
635 /*
636  * Initialise a named network device.
637  */
638 static struct device *
639 open_driver (const char *dev_name, char *ebuf, int promisc)
640 {
641   struct device *dev;
642 
643   for (dev = (struct device*)dev_base; dev; dev = dev->next)
644   {
645     PCAP_ASSERT (dev->name);
646 
647     if (strcmp (dev_name,dev->name))
648        continue;
649 
650     if (!probed_dev)   /* user didn't call pcap_lookupdev() first */
651     {
652       PCAP_ASSERT (dev->probe);
653 
654       if (!(*dev->probe)(dev))    /* call the xx_probe() function */
655       {
656         pcap_snprintf (ebuf, PCAP_ERRBUF_SIZE, "failed to detect device `%s'", dev_name);
657         return (NULL);
658       }
659       probed_dev = dev;  /* device is probed okay and may be used */
660     }
661     else if (dev != probed_dev)
662     {
663       goto not_probed;
664     }
665 
666     FLUSHK();
667 
668     /* Select what traffic to receive
669      */
670     if (promisc)
671          dev->flags |=  (IFF_ALLMULTI | IFF_PROMISC);
672     else dev->flags &= ~(IFF_ALLMULTI | IFF_PROMISC);
673 
674     PCAP_ASSERT (dev->open);
675 
676     if (!(*dev->open)(dev))
677     {
678       pcap_snprintf (ebuf, PCAP_ERRBUF_SIZE, "failed to activate device `%s'", dev_name);
679       if (pktInfo.error && !strncmp(dev->name,"pkt",3))
680       {
681         strcat (ebuf, ": ");
682         strcat (ebuf, pktInfo.error);
683       }
684       return (NULL);
685     }
686 
687     /* Some devices need this to operate in promiscous mode
688      */
689     if (promisc && dev->set_multicast_list)
690        (*dev->set_multicast_list) (dev);
691 
692     active_dev = dev;   /* remember our active device */
693     break;
694   }
695 
696   /* 'dev_name' not matched in 'dev_base' list.
697    */
698   if (!dev)
699   {
700     pcap_snprintf (ebuf, PCAP_ERRBUF_SIZE, "device `%s' not supported", dev_name);
701     return (NULL);
702   }
703 
704 not_probed:
705   if (!probed_dev)
706   {
707     pcap_snprintf (ebuf, PCAP_ERRBUF_SIZE, "device `%s' not probed", dev_name);
708     return (NULL);
709   }
710   return (dev);
711 }
712 
713 /*
714  * Deinitialise MAC driver.
715  * Set receive mode back to default mode.
716  */
717 static void close_driver (void)
718 {
719   /* !!todo: loop over all 'handle_to_device[]' ? */
720   struct device *dev = active_dev;
721 
722   if (dev && dev->close)
723   {
724     (*dev->close) (dev);
725     FLUSHK();
726   }
727 
728   active_dev = NULL;
729 
730 #ifdef USE_32BIT_DRIVERS
731   if (rx_pool)
732   {
733     k_free (rx_pool);
734     rx_pool = NULL;
735   }
736   if (dev)
737      pcibios_exit();
738 #endif
739 }
740 
741 
742 #ifdef __DJGPP__
743 static void setup_signals (void (*handler)(int))
744 {
745   signal (SIGSEGV,handler);
746   signal (SIGILL, handler);
747   signal (SIGFPE, handler);
748 }
749 
750 static void exc_handler (int sig)
751 {
752 #ifdef USE_32BIT_DRIVERS
753   if (active_dev->irq > 0)    /* excludes IRQ 0 */
754   {
755     disable_irq (active_dev->irq);
756     irq_eoi_cmd (active_dev->irq);
757     _printk_safe = 1;
758   }
759 #endif
760 
761   switch (sig)
762   {
763     case SIGSEGV:
764          fputs ("Catching SIGSEGV.\n", stderr);
765          break;
766     case SIGILL:
767          fputs ("Catching SIGILL.\n", stderr);
768          break;
769     case SIGFPE:
770          _fpreset();
771          fputs ("Catching SIGFPE.\n", stderr);
772          break;
773     default:
774          fprintf (stderr, "Catching signal %d.\n", sig);
775   }
776   exc_occured = 1;
777   close_driver();
778 }
779 #endif  /* __DJGPP__ */
780 
781 
782 /*
783  * Open the pcap device for the first client calling pcap_activate()
784  */
785 static int first_init (const char *name, char *ebuf, int promisc)
786 {
787   struct device *dev;
788 
789 #ifdef USE_32BIT_DRIVERS
790   rx_pool = k_calloc (RECEIVE_BUF_SIZE, RECEIVE_QUEUE_SIZE);
791   if (!rx_pool)
792   {
793     strcpy (ebuf, "Not enough memory (Rx pool)");
794     return (0);
795   }
796 #endif
797 
798 #ifdef __DJGPP__
799   setup_signals (exc_handler);
800 #endif
801 
802 #ifdef USE_32BIT_DRIVERS
803   init_32bit();
804 #endif
805 
806   dev = open_driver (name, ebuf, promisc);
807   if (!dev)
808   {
809 #ifdef USE_32BIT_DRIVERS
810     k_free (rx_pool);
811     rx_pool = NULL;
812 #endif
813 
814 #ifdef __DJGPP__
815     setup_signals (SIG_DFL);
816 #endif
817     return (0);
818   }
819 
820 #ifdef USE_32BIT_DRIVERS
821   /*
822    * If driver is NOT a 16-bit "pkt/ndis" driver (having a 'copy_rx_buf'
823    * set in it's probe handler), initialise near-memory ring-buffer for
824    * the 32-bit device.
825    */
826   if (dev->copy_rx_buf == NULL)
827   {
828     dev->get_rx_buf     = get_rxbuf;
829     dev->peek_rx_buf    = peek_rxbuf;
830     dev->release_rx_buf = release_rxbuf;
831     pktq_init (&dev->queue, RECEIVE_BUF_SIZE, RECEIVE_QUEUE_SIZE, rx_pool);
832   }
833 #endif
834   return (1);
835 }
836 
837 #ifdef USE_32BIT_DRIVERS
838 static void init_32bit (void)
839 {
840   static int init_pci = 0;
841 
842   if (!_printk_file)
843      _printk_init (64*1024, NULL); /* calls atexit(printk_exit) */
844 
845   if (!init_pci)
846      (void)pci_init();             /* init BIOS32+PCI interface */
847   init_pci = 1;
848 }
849 #endif
850 
851 
852 /*
853  * Hook functions for using Watt-32 together with pcap
854  */
855 static char rxbuf [ETH_MAX+100]; /* rx-buffer with some margin */
856 static WORD etype;
857 static pcap_t pcap_save;
858 
859 static void watt32_recv_hook (u_char *dummy, const struct pcap_pkthdr *pcap,
860                               const u_char *buf)
861 {
862   /* Fix me: assumes Ethernet II only */
863   struct ether_header *ep = (struct ether_header*) buf;
864 
865   memcpy (rxbuf, buf, pcap->caplen);
866   etype = ep->ether_type;
867   ARGSUSED (dummy);
868 }
869 
870 #if (WATTCP_VER >= 0x0224)
871 /*
872  * This function is used by Watt-32 to poll for a packet.
873  * i.e. it's set to bypass _eth_arrived()
874  */
875 static void *pcap_recv_hook (WORD *type)
876 {
877   int len = pcap_read_dos (&pcap_save, 1, watt32_recv_hook, NULL);
878 
879   if (len < 0)
880      return (NULL);
881 
882   *type = etype;
883   return (void*) &rxbuf;
884 }
885 
886 /*
887  * This function is called by Watt-32 (via _eth_xmit_hook).
888  * If dbug_init() was called, we should trace packets sent.
889  */
890 static int pcap_xmit_hook (const void *buf, unsigned len)
891 {
892   int rc = 0;
893 
894   if (pcap_pkt_debug > 0)
895      dbug_write ("pcap_xmit_hook: ");
896 
897   if (active_dev && active_dev->xmit)
898      if ((*active_dev->xmit) (active_dev, buf, len) > 0)
899         rc = len;
900 
901   if (pcap_pkt_debug > 0)
902      dbug_write (rc ? "ok\n" : "fail\n");
903   return (rc);
904 }
905 #endif
906 
907 static int pcap_sendpacket_dos (pcap_t *p, const void *buf, size_t len)
908 {
909   struct device *dev = p ? get_device(p->fd) : NULL;
910 
911   if (!dev || !dev->xmit)
912      return (-1);
913   return (*dev->xmit) (dev, buf, len);
914 }
915 
916 /*
917  * This function is called by Watt-32 in tcp_post_init().
918  * We should prevent Watt-32 from using BOOTP/DHCP/RARP etc.
919  */
920 static void (*prev_post_hook) (void);
921 
922 static void pcap_init_hook (void)
923 {
924   _w32__bootp_on = _w32__dhcp_on = _w32__rarp_on = 0;
925   _w32__do_mask_req = 0;
926   _w32_dynamic_host = 0;
927   if (prev_post_hook)
928     (*prev_post_hook)();
929 }
930 
931 /*
932  * Supress PRINT message from Watt-32's sock_init()
933  */
934 static void null_print (void) {}
935 
936 /*
937  * To use features of Watt-32 (netdb functions and socket etc.)
938  * we must call sock_init(). But we set various hooks to prevent
939  * using normal PKTDRVR functions in pcpkt.c. This should hopefully
940  * make Watt-32 and pcap co-operate.
941  */
942 static int init_watt32 (struct pcap *pcap, const char *dev_name, char *err_buf)
943 {
944   char *env;
945   int   rc, MTU, has_ip_addr;
946   int   using_pktdrv = 1;
947 
948   /* If user called sock_init() first, we need to reinit in
949    * order to open debug/trace-file properly
950    */
951   if (_watt_is_init)
952      sock_exit();
953 
954   env = getenv ("PCAP_TRACE");
955   if (env && atoi(env) > 0 &&
956       pcap_pkt_debug < 0)   /* if not already set */
957   {
958     dbug_init();
959     pcap_pkt_debug = atoi (env);
960   }
961 
962   _watt_do_exit      = 0;    /* prevent sock_init() calling exit() */
963   prev_post_hook     = _w32_usr_post_init;
964   _w32_usr_post_init = pcap_init_hook;
965   _w32_print_hook    = null_print;
966 
967   if (dev_name && strncmp(dev_name,"pkt",3))
968      using_pktdrv = FALSE;
969 
970   rc = sock_init();
971   has_ip_addr = (rc != 8);  /* IP-address assignment failed */
972 
973   /* if pcap is using a 32-bit driver w/o a pktdrvr loaded, we
974    * just pretend Watt-32 is initialised okay.
975    *
976    * !! fix-me: The Watt-32 config isn't done if no pktdrvr
977    *            was found. In that case my_ip_addr + sin_mask
978    *            have default values. Should be taken from another
979    *            ini-file/environment in any case (ref. tcpdump.ini)
980    */
981   _watt_is_init = 1;
982 
983   if (!using_pktdrv || !has_ip_addr)  /* for now .... */
984   {
985     static const char myip[] = "192.168.0.1";
986     static const char mask[] = "255.255.255.0";
987 
988     printf ("Just guessing, using IP %s and netmask %s\n", myip, mask);
989     my_ip_addr    = aton (myip);
990     _w32_sin_mask = aton (mask);
991   }
992   else if (rc && using_pktdrv)
993   {
994     pcap_snprintf (err_buf, PCAP_ERRBUF_SIZE, "sock_init() failed, code %d", rc);
995     return (0);
996   }
997 
998   /* Set recv-hook for peeking in _eth_arrived().
999    */
1000 #if (WATTCP_VER >= 0x0224)
1001   _eth_recv_hook = pcap_recv_hook;
1002   _eth_xmit_hook = pcap_xmit_hook;
1003 #endif
1004 
1005   /* Free the pkt-drvr handle allocated in pkt_init().
1006    * The above hooks should thus use the handle reopened in open_driver()
1007    */
1008   if (using_pktdrv)
1009   {
1010     _eth_release();
1011 /*  _eth_is_init = 1; */  /* hack to get Rx/Tx-hooks in Watt-32 working */
1012   }
1013 
1014   memcpy (&pcap_save, pcap, sizeof(pcap_save));
1015   MTU = pkt_get_mtu();
1016   pcap_save.fcode.bf_insns = NULL;
1017   pcap_save.linktype       = _eth_get_hwtype (NULL, NULL);
1018   pcap_save.snapshot       = MTU > 0 ? MTU : ETH_MAX; /* assume 1514 */
1019 
1020 #if 1
1021   /* prevent use of resolve() and resolve_ip()
1022    */
1023   last_nameserver = 0;
1024 #endif
1025   return (1);
1026 }
1027 
1028 int EISA_bus = 0;  /* Where is natural place for this? */
1029 
1030 /*
1031  * Application config hooks to set various driver parameters.
1032  */
1033 
1034 static const struct config_table debug_tab[] = {
1035             { "PKT.DEBUG",       ARG_ATOI,   &pcap_pkt_debug    },
1036             { "PKT.VECTOR",      ARG_ATOX_W, NULL               },
1037             { "NDIS.DEBUG",      ARG_ATOI,   NULL               },
1038 #ifdef USE_32BIT_DRIVERS
1039             { "3C503.DEBUG",     ARG_ATOI,   &ei_debug          },
1040             { "3C503.IO_BASE",   ARG_ATOX_W, &el2_dev.base_addr },
1041             { "3C503.MEMORY",    ARG_ATOX_W, &el2_dev.mem_start },
1042             { "3C503.IRQ",       ARG_ATOI,   &el2_dev.irq       },
1043             { "3C505.DEBUG",     ARG_ATOI,   NULL               },
1044             { "3C505.BASE",      ARG_ATOX_W, NULL               },
1045             { "3C507.DEBUG",     ARG_ATOI,   NULL               },
1046             { "3C509.DEBUG",     ARG_ATOI,   &el3_debug         },
1047             { "3C509.ILOOP",     ARG_ATOI,   &el3_max_loop      },
1048             { "3C529.DEBUG",     ARG_ATOI,   NULL               },
1049             { "3C575.DEBUG",     ARG_ATOI,   &debug_3c575       },
1050             { "3C59X.DEBUG",     ARG_ATOI,   &vortex_debug      },
1051             { "3C59X.IFACE0",    ARG_ATOI,   &vortex_options[0] },
1052             { "3C59X.IFACE1",    ARG_ATOI,   &vortex_options[1] },
1053             { "3C59X.IFACE2",    ARG_ATOI,   &vortex_options[2] },
1054             { "3C59X.IFACE3",    ARG_ATOI,   &vortex_options[3] },
1055             { "3C90X.DEBUG",     ARG_ATOX_W, &tc90xbc_debug     },
1056             { "ACCT.DEBUG",      ARG_ATOI,   &ethpk_debug       },
1057             { "CS89.DEBUG",      ARG_ATOI,   &cs89_debug        },
1058             { "RTL8139.DEBUG",   ARG_ATOI,   &rtl8139_debug     },
1059         /*  { "RTL8139.FDUPLEX", ARG_ATOI,   &rtl8139_options   }, */
1060             { "SMC.DEBUG",       ARG_ATOI,   &ei_debug          },
1061         /*  { "E100.DEBUG",      ARG_ATOI,   &e100_debug        }, */
1062             { "PCI.DEBUG",       ARG_ATOI,   &pci_debug         },
1063             { "BIOS32.DEBUG",    ARG_ATOI,   &bios32_debug      },
1064             { "IRQ.DEBUG",       ARG_ATOI,   &irq_debug         },
1065             { "TIMER.IRQ",       ARG_ATOI,   &timer_irq         },
1066 #endif
1067             { NULL }
1068           };
1069 
1070 /*
1071  * pcap_config_hook() is an extension to application's config
1072  * handling. Uses Watt-32's config-table function.
1073  */
1074 int pcap_config_hook (const char *keyword, const char *value)
1075 {
1076   return parse_config_table (debug_tab, NULL, keyword, value);
1077 }
1078 
1079 /*
1080  * Linked list of supported devices
1081  */
1082 struct device       *active_dev = NULL;      /* the device we have opened */
1083 struct device       *probed_dev = NULL;      /* the device we have probed */
1084 const struct device *dev_base   = &pkt_dev;  /* list of network devices */
1085 
1086 /*
1087  * PKTDRVR device functions
1088  */
1089 int pcap_pkt_debug = -1;
1090 
1091 static void pkt_close (struct device *dev)
1092 {
1093   BOOL okay = PktExitDriver();
1094 
1095   if (pcap_pkt_debug > 1)
1096      fprintf (stderr, "pkt_close(): %d\n", okay);
1097 
1098   if (dev->priv)
1099      free (dev->priv);
1100   dev->priv = NULL;
1101 }
1102 
1103 static int pkt_open (struct device *dev)
1104 {
1105   PKT_RX_MODE mode;
1106 
1107   if (dev->flags & IFF_PROMISC)
1108        mode = PDRX_ALL_PACKETS;
1109   else mode = PDRX_BROADCAST;
1110 
1111   if (!PktInitDriver(mode))
1112      return (0);
1113 
1114   PktResetStatistics (pktInfo.handle);
1115   PktQueueBusy (FALSE);
1116   return (1);
1117 }
1118 
1119 static int pkt_xmit (struct device *dev, const void *buf, int len)
1120 {
1121   struct net_device_stats *stats = (struct net_device_stats*) dev->priv;
1122 
1123   if (pcap_pkt_debug > 0)
1124      dbug_write ("pcap_xmit\n");
1125 
1126   if (!PktTransmit(buf,len))
1127   {
1128     stats->tx_errors++;
1129     return (0);
1130   }
1131   return (len);
1132 }
1133 
1134 static void *pkt_stats (struct device *dev)
1135 {
1136   struct net_device_stats *stats = (struct net_device_stats*) dev->priv;
1137 
1138   if (!stats || !PktSessStatistics(pktInfo.handle))
1139      return (NULL);
1140 
1141   stats->rx_packets       = pktStat.inPackets;
1142   stats->rx_errors        = pktStat.lost;
1143   stats->rx_missed_errors = PktRxDropped();
1144   return (stats);
1145 }
1146 
1147 static int pkt_probe (struct device *dev)
1148 {
1149   if (!PktSearchDriver())
1150      return (0);
1151 
1152   dev->open           = pkt_open;
1153   dev->xmit           = pkt_xmit;
1154   dev->close          = pkt_close;
1155   dev->get_stats      = pkt_stats;
1156   dev->copy_rx_buf    = PktReceive;  /* farmem peek and copy routine */
1157   dev->get_rx_buf     = NULL;
1158   dev->peek_rx_buf    = NULL;
1159   dev->release_rx_buf = NULL;
1160   dev->priv           = calloc (sizeof(struct net_device_stats), 1);
1161   if (!dev->priv)
1162      return (0);
1163   return (1);
1164 }
1165 
1166 /*
1167  * NDIS device functions
1168  */
1169 static void ndis_close (struct device *dev)
1170 {
1171 #ifdef USE_NDIS2
1172   NdisShutdown();
1173 #endif
1174   ARGSUSED (dev);
1175 }
1176 
1177 static int ndis_open (struct device *dev)
1178 {
1179   int promis = (dev->flags & IFF_PROMISC);
1180 
1181 #ifdef USE_NDIS2
1182   if (!NdisInit(promis))
1183      return (0);
1184   return (1);
1185 #else
1186   ARGSUSED (promis);
1187   return (0);
1188 #endif
1189 }
1190 
1191 static void *ndis_stats (struct device *dev)
1192 {
1193   static struct net_device_stats stats;
1194 
1195   /* to-do */
1196   ARGSUSED (dev);
1197   return (&stats);
1198 }
1199 
1200 static int ndis_probe (struct device *dev)
1201 {
1202 #ifdef USE_NDIS2
1203   if (!NdisOpen())
1204      return (0);
1205 #endif
1206 
1207   dev->open           = ndis_open;
1208   dev->xmit           = NULL;
1209   dev->close          = ndis_close;
1210   dev->get_stats      = ndis_stats;
1211   dev->copy_rx_buf    = NULL;       /* to-do */
1212   dev->get_rx_buf     = NULL;       /* upcall is from rmode driver */
1213   dev->peek_rx_buf    = NULL;
1214   dev->release_rx_buf = NULL;
1215   return (0);
1216 }
1217 
1218 /*
1219  * Search & probe for supported 32-bit (pmode) pcap devices
1220  */
1221 #if defined(USE_32BIT_DRIVERS)
1222 
1223 struct device el2_dev LOCKED_VAR = {
1224               "3c503",
1225               "EtherLink II",
1226               0,
1227               0,0,0,0,0,0,
1228               NULL,
1229               el2_probe
1230             };
1231 
1232 struct device el3_dev LOCKED_VAR = {
1233               "3c509",
1234               "EtherLink III",
1235               0,
1236               0,0,0,0,0,0,
1237               &el2_dev,
1238               el3_probe
1239             };
1240 
1241 struct device tc515_dev LOCKED_VAR = {
1242               "3c515",
1243               "EtherLink PCI",
1244               0,
1245               0,0,0,0,0,0,
1246               &el3_dev,
1247               tc515_probe
1248             };
1249 
1250 struct device tc59_dev LOCKED_VAR = {
1251               "3c59x",
1252               "EtherLink PCI",
1253               0,
1254               0,0,0,0,0,0,
1255               &tc515_dev,
1256               tc59x_probe
1257             };
1258 
1259 struct device tc90xbc_dev LOCKED_VAR = {
1260               "3c90x",
1261               "EtherLink 90X",
1262               0,
1263               0,0,0,0,0,0,
1264               &tc59_dev,
1265               tc90xbc_probe
1266             };
1267 
1268 struct device wd_dev LOCKED_VAR = {
1269               "wd",
1270               "Westen Digital",
1271               0,
1272               0,0,0,0,0,0,
1273               &tc90xbc_dev,
1274               wd_probe
1275             };
1276 
1277 struct device ne_dev LOCKED_VAR = {
1278               "ne",
1279               "NEx000",
1280               0,
1281               0,0,0,0,0,0,
1282               &wd_dev,
1283               ne_probe
1284             };
1285 
1286 struct device acct_dev LOCKED_VAR = {
1287               "acct",
1288               "Accton EtherPocket",
1289               0,
1290               0,0,0,0,0,0,
1291               &ne_dev,
1292               ethpk_probe
1293             };
1294 
1295 struct device cs89_dev LOCKED_VAR = {
1296               "cs89",
1297               "Crystal Semiconductor",
1298               0,
1299               0,0,0,0,0,0,
1300               &acct_dev,
1301               cs89x0_probe
1302             };
1303 
1304 struct device rtl8139_dev LOCKED_VAR = {
1305               "rtl8139",
1306               "RealTek PCI",
1307               0,
1308               0,0,0,0,0,0,
1309               &cs89_dev,
1310               rtl8139_probe     /* dev->probe routine */
1311             };
1312 
1313 /*
1314  * Dequeue routine is called by polling.
1315  * NOTE: the queue-element is not copied, only a pointer is
1316  * returned at '*buf'
1317  */
1318 int peek_rxbuf (BYTE **buf)
1319 {
1320   struct rx_elem *tail, *head;
1321 
1322   PCAP_ASSERT (pktq_check (&active_dev->queue));
1323 
1324   DISABLE();
1325   tail = pktq_out_elem (&active_dev->queue);
1326   head = pktq_in_elem (&active_dev->queue);
1327   ENABLE();
1328 
1329   if (head != tail)
1330   {
1331     PCAP_ASSERT (tail->size < active_dev->queue.elem_size-4-2);
1332 
1333     *buf = &tail->data[0];
1334     return (tail->size);
1335   }
1336   *buf = NULL;
1337   return (0);
1338 }
1339 
1340 /*
1341  * Release buffer we peeked at above.
1342  */
1343 int release_rxbuf (BYTE *buf)
1344 {
1345 #ifndef NDEBUG
1346   struct rx_elem *tail = pktq_out_elem (&active_dev->queue);
1347 
1348   PCAP_ASSERT (&tail->data[0] == buf);
1349 #else
1350   ARGSUSED (buf);
1351 #endif
1352   pktq_inc_out (&active_dev->queue);
1353   return (1);
1354 }
1355 
1356 /*
1357  * get_rxbuf() routine (in locked code) is called from IRQ handler
1358  * to request a buffer. Interrupts are disabled and we have a 32kB stack.
1359  */
1360 BYTE *get_rxbuf (int len)
1361 {
1362   int idx;
1363 
1364   if (len < ETH_MIN || len > ETH_MAX)
1365      return (NULL);
1366 
1367   idx = pktq_in_index (&active_dev->queue);
1368 
1369 #ifdef DEBUG
1370   {
1371     static int fan_idx LOCKED_VAR = 0;
1372     writew ("-\\|/"[fan_idx++] | (15 << 8),      /* white on black colour */
1373             0xB8000 + 2*79);  /* upper-right corner, 80-col colour screen */
1374     fan_idx &= 3;
1375   }
1376 /* writew (idx + '0' + 0x0F00, 0xB8000 + 2*78); */
1377 #endif
1378 
1379   if (idx != active_dev->queue.out_index)
1380   {
1381     struct rx_elem *head = pktq_in_elem (&active_dev->queue);
1382 
1383     head->size = len;
1384     active_dev->queue.in_index = idx;
1385     return (&head->data[0]);
1386   }
1387 
1388   /* !!to-do: drop 25% of the oldest element
1389    */
1390   pktq_clear (&active_dev->queue);
1391   return (NULL);
1392 }
1393 
1394 /*
1395  *  Simple ring-buffer queue handler for reception of packets
1396  *  from network driver.
1397  */
1398 #define PKTQ_MARKER  0xDEADBEEF
1399 
1400 static int pktq_check (struct rx_ringbuf *q)
1401 {
1402 #ifndef NDEBUG
1403   int   i;
1404   char *buf;
1405 #endif
1406 
1407   if (!q || !q->num_elem || !q->buf_start)
1408      return (0);
1409 
1410 #ifndef NDEBUG
1411   buf = q->buf_start;
1412 
1413   for (i = 0; i < q->num_elem; i++)
1414   {
1415     buf += q->elem_size;
1416     if (*(DWORD*)(buf - sizeof(DWORD)) != PKTQ_MARKER)
1417        return (0);
1418   }
1419 #endif
1420   return (1);
1421 }
1422 
1423 static int pktq_init (struct rx_ringbuf *q, int size, int num, char *pool)
1424 {
1425   int i;
1426 
1427   q->elem_size = size;
1428   q->num_elem  = num;
1429   q->buf_start = pool;
1430   q->in_index  = 0;
1431   q->out_index = 0;
1432 
1433   PCAP_ASSERT (size >= sizeof(struct rx_elem) + sizeof(DWORD));
1434   PCAP_ASSERT (num);
1435   PCAP_ASSERT (pool);
1436 
1437   for (i = 0; i < num; i++)
1438   {
1439 #if 0
1440     struct rx_elem *elem = (struct rx_elem*) pool;
1441 
1442     /* assert dword aligned elements
1443      */
1444     PCAP_ASSERT (((unsigned)(&elem->data[0]) & 3) == 0);
1445 #endif
1446     pool += size;
1447     *(DWORD*) (pool - sizeof(DWORD)) = PKTQ_MARKER;
1448   }
1449   return (1);
1450 }
1451 
1452 /*
1453  * Increment the queue 'out_index' (tail).
1454  * Check for wraps.
1455  */
1456 static int pktq_inc_out (struct rx_ringbuf *q)
1457 {
1458   q->out_index++;
1459   if (q->out_index >= q->num_elem)
1460       q->out_index = 0;
1461   return (q->out_index);
1462 }
1463 
1464 /*
1465  * Return the queue's next 'in_index' (head).
1466  * Check for wraps.
1467  */
1468 static int pktq_in_index (struct rx_ringbuf *q)
1469 {
1470   volatile int index = q->in_index + 1;
1471 
1472   if (index >= q->num_elem)
1473       index = 0;
1474   return (index);
1475 }
1476 
1477 /*
1478  * Return the queue's head-buffer.
1479  */
1480 static struct rx_elem *pktq_in_elem (struct rx_ringbuf *q)
1481 {
1482   return (struct rx_elem*) (q->buf_start + (q->elem_size * q->in_index));
1483 }
1484 
1485 /*
1486  * Return the queue's tail-buffer.
1487  */
1488 static struct rx_elem *pktq_out_elem (struct rx_ringbuf *q)
1489 {
1490   return (struct rx_elem*) (q->buf_start + (q->elem_size * q->out_index));
1491 }
1492 
1493 /*
1494  * Clear the queue ring-buffer by setting head=tail.
1495  */
1496 static void pktq_clear (struct rx_ringbuf *q)
1497 {
1498   q->in_index = q->out_index;
1499 }
1500 
1501 /*
1502  * Symbols that must be linkable for "gcc -O0"
1503  */
1504 #undef __IOPORT_H
1505 #undef __DMA_H
1506 
1507 #define extern
1508 #define __inline__
1509 
1510 #include "msdos/pm_drvr/ioport.h"
1511 #include "msdos/pm_drvr/dma.h"
1512 
1513 #endif /* USE_32BIT_DRIVERS */
1514 
1515