src/Unix/ether_unix.cpp

/*
 *  ether_unix.cpp - Ethernet device driver, Unix specific stuff (Linux and FreeBSD)
 *
 *  Basilisk II (C) 1997-2001 Christian Bauer
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "sysdeps.h"

#include <sys/ioctl.h>
#include <sys/poll.h>
#include <pthread.h>
#include <semaphore.h>
#include <errno.h>
#include <stdio.h>

#if defined(__FreeBSD__)
#include <sys/socket.h>
#include <net/if.h>
#endif

#include "cpu_emulation.h"
#include "main.h"
#include "macos_util.h"
#include "prefs.h"
#include "user_strings.h"
#include "ether.h"
#include "ether_defs.h"

#define DEBUG 0
#include "debug.h"

#define MONITOR 0


// List of attached protocols
struct NetProtocol {
        NetProtocol *next;
        uint16 type;
        uint32 handler;
};

static NetProtocol *prot_list = NULL;


// Global variables
static int fd = -1;                                                     // fd of sheep_net device
static pthread_t ether_thread;                          // Packet reception thread
static pthread_attr_t ether_thread_attr;        // Packet reception thread attributes
static bool thread_active = false;                      // Flag: Packet reception thread installed
static sem_t int_ack;                                           // Interrupt acknowledge semaphore
static bool is_ethertap;                                        // Flag: Ethernet device is ethertap

// Prototypes
static void *receive_func(void *arg);


/*
 *  Find protocol in list
 */

static NetProtocol *find_protocol(uint16 type)
{
        // All 802.2 types are the same
        if (type <= 1500)
                type = 0;

        // Search list (we could use hashing here but there are usually only three
        // handlers installed: 0x0000 for AppleTalk and 0x0800/0x0806 for TCP/IP)
        NetProtocol *p = prot_list;
        while (p) {
                if (p->type == type)
                        return p;
                p = p->next;
        }
        return NULL;
}


/*
 *  Remove all protocols
 */

static void remove_all_protocols(void)
{
        NetProtocol *p = prot_list;
        while (p) {
                NetProtocol *next = p->next;
                delete p;
                p = next;
        }
        prot_list = NULL;
}


/*
 *  Initialization
 */

void EtherInit(void)
{
        int nonblock = 1;
        char str[256];

        // Do nothing if no Ethernet device specified
        const char *name = PrefsFindString("ether");
        if (name == NULL)
                return;

        // Is it Ethertap?
        is_ethertap = (strncmp(name, "tap", 3) == 0);

        // Open sheep_net or ethertap device
        char dev_name[16];
        if (is_ethertap)
                sprintf(dev_name, "/dev/%s", name);
        else
                strcpy(dev_name, "/dev/sheep_net");
        fd = open(dev_name, O_RDWR);
        if (fd < 0) {
                sprintf(str, GetString(STR_NO_SHEEP_NET_DRIVER_WARN), dev_name, strerror(errno));
                WarningAlert(str);
                goto open_error;
        }

#if defined(__linux__)
        // Attach sheep_net to selected Ethernet card
        if (!is_ethertap && ioctl(fd, SIOCSIFLINK, name) < 0) {
                sprintf(str, GetString(STR_SHEEP_NET_ATTACH_WARN), strerror(errno));
                WarningAlert(str);
                goto open_error;
        }
#endif

        // Set nonblocking I/O
        ioctl(fd, FIONBIO, &nonblock);

        // Get Ethernet address
        if (is_ethertap) {
                pid_t p = getpid();     // If configured for multicast, ethertap requires that the lower 32 bit of the Ethernet address are our PID
                ether_addr[0] = 0xfe;
                ether_addr[1] = 0xfd;
                ether_addr[2] = p >> 24;
                ether_addr[3] = p >> 16;
                ether_addr[4] = p >> 8;
                ether_addr[5] = p;
        } else
                ioctl(fd, SIOCGIFADDR, ether_addr);
        D(bug("Ethernet address %02x %02x %02x %02x %02x %02x\n", ether_addr[0], ether_addr[1], ether_addr[2], ether_addr[3], ether_addr[4], ether_addr[5]));

        // Start packet reception thread
        if (sem_init(&int_ack, 0, 0) < 0) {
                printf("WARNING: Cannot init semaphore");
                goto open_error;
        }
        pthread_attr_init(&ether_thread_attr);
#if defined(_POSIX_THREAD_PRIORITY_SCHEDULING)
        if (geteuid() == 0) {
                pthread_attr_setinheritsched(&ether_thread_attr, PTHREAD_EXPLICIT_SCHED);
                pthread_attr_setschedpolicy(&ether_thread_attr, SCHED_FIFO);
                struct sched_param fifo_param;
                fifo_param.sched_priority = (sched_get_priority_min(SCHED_FIFO) + sched_get_priority_max(SCHED_FIFO)) / 2 + 1;
                pthread_attr_setschedparam(&ether_thread_attr, &fifo_param);
        }
#endif
        thread_active = (pthread_create(&ether_thread, &ether_thread_attr, receive_func, NULL) == 0);
        if (!thread_active) {
                printf("WARNING: Cannot start Ethernet thread");
                goto open_error;
        }

        // Everything OK
        net_open = true;
        return;

open_error:
        if (thread_active) {
                pthread_cancel(ether_thread);
                pthread_join(ether_thread, NULL);
                sem_destroy(&int_ack);
                thread_active = false;
        }
        if (fd > 0) {
                close(fd);
                fd = -1;
        }
}


/*
 *  Deinitialization
 */

void EtherExit(void)
{
        // Stop reception thread
        if (thread_active) {
                pthread_cancel(ether_thread);
                pthread_join(ether_thread, NULL);
                sem_destroy(&int_ack);
                thread_active = false;
        }

        // Close sheep_net device
        if (fd > 0)
                close(fd);

        // Remove all protocols
        remove_all_protocols();
}


/*
 *  Reset
 */

void EtherReset(void)
{
        remove_all_protocols();
}


/*
 *  Add multicast address
 */

int16 ether_add_multicast(uint32 pb)
{
        if (ioctl(fd, SIOCADDMULTI, Mac2HostAddr(pb + eMultiAddr)) < 0) {
                D(bug("WARNING: Couldn't enable multicast address\n"));
                if (is_ethertap)
                        return noErr;
                else
                        return eMultiErr;
        } else
                return noErr;
}


/*
 *  Delete multicast address
 */

int16 ether_del_multicast(uint32 pb)
{
        if (ioctl(fd, SIOCDELMULTI, Mac2HostAddr(pb + eMultiAddr)) < 0) {
                D(bug("WARNING: Couldn't disable multicast address\n"));
                return eMultiErr;
        } else
                return noErr;
}


/*
 *  Attach protocol handler
 */

int16 ether_attach_ph(uint16 type, uint32 handler)
{
        // Already attached?
        NetProtocol *p = find_protocol(type);
        if (p != NULL)
                return lapProtErr;
        else {
                // No, create and attach
                p = new NetProtocol;
                p->next = prot_list;
                p->type = type;
                p->handler = handler;
                prot_list = p;
                return noErr;
        }
}


/*
 *  Detach protocol handler
 */

int16 ether_detach_ph(uint16 type)
{
        NetProtocol *p = find_protocol(type);
        if (p != NULL) {
                NetProtocol *q = prot_list;
                if (p == q) {
                        prot_list = p->next;
                        delete p;
                        return noErr;
                }
                while (q) {
                        if (q->next == p) {
                                q->next = p->next;
                                delete p;
                                return noErr;
                        }
                        q = q->next;
                }
                return lapProtErr;
        } else
                return lapProtErr;
}


/*
 *  Transmit raw ethernet packet
 */

int16 ether_write(uint32 wds)
{
        // Set source address
        uint32 hdr = ReadMacInt32(wds + 2);
        Host2Mac_memcpy(hdr + 6, ether_addr, 6);

        // Copy packet to buffer
        uint8 packet[1516], *p = packet;
        int len = 0;
#if defined(__linux__)
        if (is_ethertap) {
                *p++ = 0;       // Linux ethertap discards the first 2 bytes
                *p++ = 0;
                len += 2;
        }
#endif
        for (;;) {
                int w = ReadMacInt16(wds);
                if (w == 0)
                        break;
                Mac2Host_memcpy(p, ReadMacInt32(wds + 2), w);
                len += w;
                p += w;
                wds += 6;
        }

#if MONITOR
        bug("Sending Ethernet packet:\n");
        for (int i=0; i<len; i++) {
                bug("%02x ", packet[i]);
        }
        bug("\n");
#endif

        // Transmit packet
        if (write(fd, packet, len) < 0) {
                D(bug("WARNING: Couldn't transmit packet\n"));
                return excessCollsns;
        } else
                return noErr;
}


/*
 *  Packet reception thread
 */

static void *receive_func(void *arg)
{
        for (;;) {

                // Wait for packets to arrive
                struct pollfd pf = {fd, POLLIN, 0};
                int res = poll(&pf, 1, -1);
                if (res <= 0)
                        break;

                // Trigger Ethernet interrupt
                D(bug(" packet received, triggering Ethernet interrupt\n"));
                SetInterruptFlag(INTFLAG_ETHER);
                TriggerInterrupt();

                // Wait for interrupt acknowledge by EtherInterrupt()
                sem_wait(&int_ack);
        }
        return NULL;
}


/*
 *  Ethernet interrupt - activate deferred tasks to call IODone or protocol handlers
 */

void EtherInterrupt(void)
{
        D(bug("EtherIRQ\n"));

        // Call protocol handler for received packets
        uint8 packet[1516];
        for (;;) {

                // Read packet from sheep_net device
#if defined(__linux__)
                ssize_t length = read(fd, packet, is_ethertap ? 1516 : 1514);
#else
                ssize_t length = read(fd, packet, 1514);
#endif
                if (length < 14)
                        break;

#if MONITOR
                bug("Receiving Ethernet packet:\n");
                for (int i=0; i<length; i++) {
                        bug("%02x ", packet[i]);
                }
                bug("\n");
#endif

                // Pointer to packet data (Ethernet header)
                uint8 *p = packet;
#if defined(__linux__)
                if (is_ethertap) {
                        p += 2;                 // Linux ethertap has two random bytes before the packet
                        length -= 2;
                }
#endif

                // Get packet type
                uint16 type = ntohs(*(uint16 *)(p + 12));

                // Look for protocol
                NetProtocol *prot = find_protocol(type);
                if (prot == NULL)
                        continue;

                // No default handler
                if (prot->handler == 0)
                        continue;

                // Copy header to RHA
                Host2Mac_memcpy(ether_data + ed_RHA, p, 14);
                D(bug(" header %08lx%04lx %08lx%04lx %04lx\n", ReadMacInt32(ether_data + ed_RHA), ReadMacInt16(ether_data + ed_RHA + 4), ReadMacInt32(ether_data + ed_RHA + 6), ReadMacInt16(ether_data + ed_RHA + 10), ReadMacInt16(ether_data + ed_RHA + 12)));

                // Call protocol handler
                M68kRegisters r;
                r.d[0] = type;                                                                  // Packet type
                r.d[1] = length - 14;                                                   // Remaining packet length (without header, for ReadPacket)
                r.a[0] = (uint32)p + 14;                                                // Pointer to packet (host address, for ReadPacket)
                r.a[3] = ether_data + ed_RHA + 14;                              // Pointer behind header in RHA
                r.a[4] = ether_data + ed_ReadPacket;                    // Pointer to ReadPacket/ReadRest routines
                D(bug(" calling protocol handler %08lx, type %08lx, length %08lx, data %08lx, rha %08lx, read_packet %08lx\n", prot->handler, r.d[0], r.d[1], r.a[0], r.a[3], r.a[4]));
                Execute68k(prot->handler, &r);
        }

        // Acknowledge interrupt to reception thread
        D(bug(" EtherIRQ done\n"));
        sem_post(&int_ack);
}
Revision:	1.1
Committed:	2001-03-29T14:20:53Z (23 years, 3 months ago) by cebix
Branch:	MAIN
CVS Tags:	snapshot-29052001, release-0_9-1
Log Message:	- FreeBSD configure script cleanups [Michael Alyn Miller] - ether_linux.cpp moved and renamed to ether_unix.cpp, now also works with the tap driver under FreeBSD [Michael Alyn Miller] - fpu_x86_asm.h: fixed problem in with newer GCC pre-processors
#	Content
1	/*
2	* ether_unix.cpp - Ethernet device driver, Unix specific stuff (Linux and FreeBSD)
3	*
4	* Basilisk II (C) 1997-2001 Christian Bauer
5	*
6	* This program is free software; you can redistribute it and/or modify
7	* it under the terms of the GNU General Public License as published by
8	* the Free Software Foundation; either version 2 of the License, or
9	* (at your option) any later version.
10	*
11	* This program is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License
17	* along with this program; if not, write to the Free Software
18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19	*/
20
21	#include "sysdeps.h"
22
23	#include <sys/ioctl.h>
24	#include <sys/poll.h>
25	#include <pthread.h>
26	#include <semaphore.h>
27	#include <errno.h>
28	#include <stdio.h>
29
30	#if defined(__FreeBSD__)
31	#include <sys/socket.h>
32	#include <net/if.h>
33	#endif
34
35	#include "cpu_emulation.h"
36	#include "main.h"
37	#include "macos_util.h"
38	#include "prefs.h"
39	#include "user_strings.h"
40	#include "ether.h"
41	#include "ether_defs.h"
42
43	#define DEBUG 0
44	#include "debug.h"
45
46	#define MONITOR 0
47
48
49	// List of attached protocols
50	struct NetProtocol {
51	NetProtocol *next;
52	uint16 type;
53	uint32 handler;
54	};
55
56	static NetProtocol *prot_list = NULL;
57
58
59	// Global variables
60	static int fd = -1; // fd of sheep_net device
61	static pthread_t ether_thread; // Packet reception thread
62	static pthread_attr_t ether_thread_attr; // Packet reception thread attributes
63	static bool thread_active = false; // Flag: Packet reception thread installed
64	static sem_t int_ack; // Interrupt acknowledge semaphore
65	static bool is_ethertap; // Flag: Ethernet device is ethertap
66
67	// Prototypes
68	static void receive_func(void arg);
69
70
71	/*
72	* Find protocol in list
73	*/
74
75	static NetProtocol *find_protocol(uint16 type)
76	{
77	// All 802.2 types are the same
78	if (type <= 1500)
79	type = 0;
80
81	// Search list (we could use hashing here but there are usually only three
82	// handlers installed: 0x0000 for AppleTalk and 0x0800/0x0806 for TCP/IP)
83	NetProtocol *p = prot_list;
84	while (p) {
85	if (p->type == type)
86	return p;
87	p = p->next;
88	}
89	return NULL;
90	}
91
92
93	/*
94	* Remove all protocols
95	*/
96
97	static void remove_all_protocols(void)
98	{
99	NetProtocol *p = prot_list;
100	while (p) {
101	NetProtocol *next = p->next;
102	delete p;
103	p = next;
104	}
105	prot_list = NULL;
106	}
107
108
109	/*
110	* Initialization
111	*/
112
113	void EtherInit(void)
114	{
115	int nonblock = 1;
116	char str[256];
117
118	// Do nothing if no Ethernet device specified
119	const char *name = PrefsFindString("ether");
120	if (name == NULL)
121	return;
122
123	// Is it Ethertap?
124	is_ethertap = (strncmp(name, "tap", 3) == 0);
125
126	// Open sheep_net or ethertap device
127	char dev_name[16];
128	if (is_ethertap)
129	sprintf(dev_name, "/dev/%s", name);
130	else
131	strcpy(dev_name, "/dev/sheep_net");
132	fd = open(dev_name, O_RDWR);
133	if (fd < 0) {
134	sprintf(str, GetString(STR_NO_SHEEP_NET_DRIVER_WARN), dev_name, strerror(errno));
135	WarningAlert(str);
136	goto open_error;
137	}
138
139	#if defined(__linux__)
140	// Attach sheep_net to selected Ethernet card
141	if (!is_ethertap && ioctl(fd, SIOCSIFLINK, name) < 0) {
142	sprintf(str, GetString(STR_SHEEP_NET_ATTACH_WARN), strerror(errno));
143	WarningAlert(str);
144	goto open_error;
145	}
146	#endif
147
148	// Set nonblocking I/O
149	ioctl(fd, FIONBIO, &nonblock);
150
151	// Get Ethernet address
152	if (is_ethertap) {
153	pid_t p = getpid(); // If configured for multicast, ethertap requires that the lower 32 bit of the Ethernet address are our PID
154	ether_addr[0] = 0xfe;
155	ether_addr[1] = 0xfd;
156	ether_addr[2] = p >> 24;
157	ether_addr[3] = p >> 16;
158	ether_addr[4] = p >> 8;
159	ether_addr[5] = p;
160	} else
161	ioctl(fd, SIOCGIFADDR, ether_addr);
162	D(bug("Ethernet address %02x %02x %02x %02x %02x %02x\n", ether_addr[0], ether_addr[1], ether_addr[2], ether_addr[3], ether_addr[4], ether_addr[5]));
163
164	// Start packet reception thread
165	if (sem_init(&int_ack, 0, 0) < 0) {
166	printf("WARNING: Cannot init semaphore");
167	goto open_error;
168	}
169	pthread_attr_init(&ether_thread_attr);
170	#if defined(_POSIX_THREAD_PRIORITY_SCHEDULING)
171	if (geteuid() == 0) {
172	pthread_attr_setinheritsched(&ether_thread_attr, PTHREAD_EXPLICIT_SCHED);
173	pthread_attr_setschedpolicy(&ether_thread_attr, SCHED_FIFO);
174	struct sched_param fifo_param;
175	fifo_param.sched_priority = (sched_get_priority_min(SCHED_FIFO) + sched_get_priority_max(SCHED_FIFO)) / 2 + 1;
176	pthread_attr_setschedparam(&ether_thread_attr, &fifo_param);
177	}
178	#endif
179	thread_active = (pthread_create(&ether_thread, &ether_thread_attr, receive_func, NULL) == 0);
180	if (!thread_active) {
181	printf("WARNING: Cannot start Ethernet thread");
182	goto open_error;
183	}
184
185	// Everything OK
186	net_open = true;
187	return;
188
189	open_error:
190	if (thread_active) {
191	pthread_cancel(ether_thread);
192	pthread_join(ether_thread, NULL);
193	sem_destroy(&int_ack);
194	thread_active = false;
195	}
196	if (fd > 0) {
197	close(fd);
198	fd = -1;
199	}
200	}
201
202
203	/*
204	* Deinitialization
205	*/
206
207	void EtherExit(void)
208	{
209	// Stop reception thread
210	if (thread_active) {
211	pthread_cancel(ether_thread);
212	pthread_join(ether_thread, NULL);
213	sem_destroy(&int_ack);
214	thread_active = false;
215	}
216
217	// Close sheep_net device
218	if (fd > 0)
219	close(fd);
220
221	// Remove all protocols
222	remove_all_protocols();
223	}
224
225
226	/*
227	* Reset
228	*/
229
230	void EtherReset(void)
231	{
232	remove_all_protocols();
233	}
234
235
236	/*
237	* Add multicast address
238	*/
239
240	int16 ether_add_multicast(uint32 pb)
241	{
242	if (ioctl(fd, SIOCADDMULTI, Mac2HostAddr(pb + eMultiAddr)) < 0) {
243	D(bug("WARNING: Couldn't enable multicast address\n"));
244	if (is_ethertap)
245	return noErr;
246	else
247	return eMultiErr;
248	} else
249	return noErr;
250	}
251
252
253	/*
254	* Delete multicast address
255	*/
256
257	int16 ether_del_multicast(uint32 pb)
258	{
259	if (ioctl(fd, SIOCDELMULTI, Mac2HostAddr(pb + eMultiAddr)) < 0) {
260	D(bug("WARNING: Couldn't disable multicast address\n"));
261	return eMultiErr;
262	} else
263	return noErr;
264	}
265
266
267	/*
268	* Attach protocol handler
269	*/
270
271	int16 ether_attach_ph(uint16 type, uint32 handler)
272	{
273	// Already attached?
274	NetProtocol *p = find_protocol(type);
275	if (p != NULL)
276	return lapProtErr;
277	else {
278	// No, create and attach
279	p = new NetProtocol;
280	p->next = prot_list;
281	p->type = type;
282	p->handler = handler;
283	prot_list = p;
284	return noErr;
285	}
286	}
287
288
289	/*
290	* Detach protocol handler
291	*/
292
293	int16 ether_detach_ph(uint16 type)
294	{
295	NetProtocol *p = find_protocol(type);
296	if (p != NULL) {
297	NetProtocol *q = prot_list;
298	if (p == q) {
299	prot_list = p->next;
300	delete p;
301	return noErr;
302	}
303	while (q) {
304	if (q->next == p) {
305	q->next = p->next;
306	delete p;
307	return noErr;
308	}
309	q = q->next;
310	}
311	return lapProtErr;
312	} else
313	return lapProtErr;
314	}
315
316
317	/*
318	* Transmit raw ethernet packet
319	*/
320
321	int16 ether_write(uint32 wds)
322	{
323	// Set source address
324	uint32 hdr = ReadMacInt32(wds + 2);
325	Host2Mac_memcpy(hdr + 6, ether_addr, 6);
326
327	// Copy packet to buffer
328	uint8 packet[1516], *p = packet;
329	int len = 0;
330	#if defined(__linux__)
331	if (is_ethertap) {
332	*p++ = 0; // Linux ethertap discards the first 2 bytes
333	*p++ = 0;
334	len += 2;
335	}
336	#endif
337	for (;;) {
338	int w = ReadMacInt16(wds);
339	if (w == 0)
340	break;
341	Mac2Host_memcpy(p, ReadMacInt32(wds + 2), w);
342	len += w;
343	p += w;
344	wds += 6;
345	}
346
347	#if MONITOR
348	bug("Sending Ethernet packet:\n");
349	for (int i=0; i<len; i++) {
350	bug("%02x ", packet[i]);
351	}
352	bug("\n");
353	#endif
354
355	// Transmit packet
356	if (write(fd, packet, len) < 0) {
357	D(bug("WARNING: Couldn't transmit packet\n"));
358	return excessCollsns;
359	} else
360	return noErr;
361	}
362
363
364	/*
365	* Packet reception thread
366	*/
367
368	static void receive_func(void arg)
369	{
370	for (;;) {
371
372	// Wait for packets to arrive
373	struct pollfd pf = {fd, POLLIN, 0};
374	int res = poll(&pf, 1, -1);
375	if (res <= 0)
376	break;
377
378	// Trigger Ethernet interrupt
379	D(bug(" packet received, triggering Ethernet interrupt\n"));
380	SetInterruptFlag(INTFLAG_ETHER);
381	TriggerInterrupt();
382
383	// Wait for interrupt acknowledge by EtherInterrupt()
384	sem_wait(&int_ack);
385	}
386	return NULL;
387	}
388
389
390	/*
391	* Ethernet interrupt - activate deferred tasks to call IODone or protocol handlers
392	*/
393
394	void EtherInterrupt(void)
395	{
396	D(bug("EtherIRQ\n"));
397
398	// Call protocol handler for received packets
399	uint8 packet[1516];
400	for (;;) {
401
402	// Read packet from sheep_net device
403	#if defined(__linux__)
404	ssize_t length = read(fd, packet, is_ethertap ? 1516 : 1514);
405	#else
406	ssize_t length = read(fd, packet, 1514);
407	#endif
408	if (length < 14)
409	break;
410
411	#if MONITOR
412	bug("Receiving Ethernet packet:\n");
413	for (int i=0; i<length; i++) {
414	bug("%02x ", packet[i]);
415	}
416	bug("\n");
417	#endif
418
419	// Pointer to packet data (Ethernet header)
420	uint8 *p = packet;
421	#if defined(__linux__)
422	if (is_ethertap) {
423	p += 2; // Linux ethertap has two random bytes before the packet
424	length -= 2;
425	}
426	#endif
427
428	// Get packet type
429	uint16 type = ntohs((uint16 )(p + 12));
430
431	// Look for protocol
432	NetProtocol *prot = find_protocol(type);
433	if (prot == NULL)
434	continue;
435
436	// No default handler
437	if (prot->handler == 0)
438	continue;
439
440	// Copy header to RHA
441	Host2Mac_memcpy(ether_data + ed_RHA, p, 14);
442	D(bug(" header %08lx%04lx %08lx%04lx %04lx\n", ReadMacInt32(ether_data + ed_RHA), ReadMacInt16(ether_data + ed_RHA + 4), ReadMacInt32(ether_data + ed_RHA + 6), ReadMacInt16(ether_data + ed_RHA + 10), ReadMacInt16(ether_data + ed_RHA + 12)));
443
444	// Call protocol handler
445	M68kRegisters r;
446	r.d[0] = type; // Packet type
447	r.d[1] = length - 14; // Remaining packet length (without header, for ReadPacket)
448	r.a[0] = (uint32)p + 14; // Pointer to packet (host address, for ReadPacket)
449	r.a[3] = ether_data + ed_RHA + 14; // Pointer behind header in RHA
450	r.a[4] = ether_data + ed_ReadPacket; // Pointer to ReadPacket/ReadRest routines
451	D(bug(" calling protocol handler %08lx, type %08lx, length %08lx, data %08lx, rha %08lx, read_packet %08lx\n", prot->handler, r.d[0], r.d[1], r.a[0], r.a[3], r.a[4]));
452	Execute68k(prot->handler, &r);
453	}
454
455	// Acknowledge interrupt to reception thread
456	D(bug(" EtherIRQ done\n"));
457	sem_post(&int_ack);
458	}