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 <sys/socket.h>
#include <netinet/in.h>
#include <pthread.h>
#include <semaphore.h>
#include <errno.h>
#include <stdio.h>
#include <map>

#if defined(__FreeBSD__)
#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"

#ifndef NO_STD_NAMESPACE
using std::map;
#endif

#define DEBUG 0
#include "debug.h"

#define MONITOR 0


// 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
static bool udp_tunnel;                                         // Flag: UDP tunnelling active, fd is the socket descriptor

// Attached network protocols, maps protocol type to MacOS handler address
static map<uint16, uint32> net_protocols;

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


/*
 *  Start packet reception thread
 */

static bool start_thread(void)
{
        if (sem_init(&int_ack, 0, 0) < 0) {
                printf("WARNING: Cannot init semaphore");
                return false;
        }

        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");
                return false;
        }

        return true;
}


/*
 *  Stop packet reception thread
 */

static void stop_thread(void)
{
        if (thread_active) {
                pthread_cancel(ether_thread);
                pthread_join(ether_thread, NULL);
                sem_destroy(&int_ack);
                thread_active = false;
        }
}


/*
 *  Initialization
 */

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

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

        // 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 (!start_thread())
                goto open_error;

        // Everything OK
        return true;

open_error:
        stop_thread();

        if (fd > 0) {
                close(fd);
                fd = -1;
        }
        return false;
}


/*
 *  Deinitialization
 */

void ether_exit(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);
}


/*
 *  Reset
 */

void ether_reset(void)
{
        net_protocols.clear();
}


/*
 *  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)
{
        if (net_protocols.find(type) != net_protocols.end())
                return lapProtErr;
        net_protocols[type] = handler;
        return noErr;
}


/*
 *  Detach protocol handler
 */

int16 ether_detach_ph(uint16 type)
{
        if (net_protocols.erase(type) == 0)
                return lapProtErr;
        return noErr;
}


/*
 *  Transmit raw ethernet packet
 */

int16 ether_write(uint32 wds)
{
        // 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
        len += ether_wds_to_buffer(wds, p);

#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;
}


/*
 *  Start UDP packet reception thread
 */

bool ether_start_udp_thread(int socket_fd)
{
        fd = socket_fd;
        udp_tunnel = true;
        return start_thread();
}


/*
 *  Stop UDP packet reception thread
 */

void ether_stop_udp_thread(void)
{
        stop_thread();
        fd = -1;
}


/*
 *  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];
        ssize_t length;
        for (;;) {

                if (udp_tunnel) {

                        // Read packet from socket
                        struct sockaddr_in from;
                        socklen_t from_len = sizeof(from);
                        length = recvfrom(fd, packet, 1514, 0, (struct sockaddr *)&from, &from_len);
                        if (length < 14)
                                break;
                        ether_udp_read(packet, length, &from);

                } else {

                        // Read packet from sheep_net device
#if defined(__linux__)
                        length = read(fd, packet, is_ethertap ? 1516 : 1514);
#else
                        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 = (p[12] << 8) | p[13];

                        // Look for protocol
                        uint16 search_type = (type <= 1500 ? 0 : type);
                        if (net_protocols.find(search_type) == net_protocols.end())
                                continue;
                        uint32 handler = net_protocols[search_type];

                        // No default handler
                        if (handler == 0)
                                continue;

                        // Copy header to RHA
                        Host2Mac_memcpy(ether_data + ed_RHA, p, 14);
                        D(bug(" header %08x%04x %08x%04x %04x\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 %08x, type %08x, length %08x, data %08x, rha %08x, read_packet %08x\n", handler, r.d[0], r.d[1], r.a[0], r.a[3], r.a[4]));
                        Execute68k(handler, &r);
                }
        }

        // Acknowledge interrupt to reception thread
        D(bug(" EtherIRQ done\n"));
        sem_post(&int_ack);
}
Revision:	1.4
Committed:	2001-07-13T18:49:29Z (23 years ago) by cebix
Branch:	MAIN
Changes since 1.3:	+0 -4 lines
Log Message:	- outgoing packet source address is set in ether.cpp - UDP tunnelling sends packets to Ethernet broadcast address as IP broadcasts
#	User	Rev	Content
1	cebix	1.1	/*
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	cebix	1.3	#include <sys/socket.h>
26			#include <netinet/in.h>
27	cebix	1.1	#include <pthread.h>
28			#include <semaphore.h>
29			#include <errno.h>
30			#include <stdio.h>
31	cebix	1.3	#include <map>
32	cebix	1.2
33	cebix	1.1	#if defined(__FreeBSD__)
34			#include <net/if.h>
35			#endif
36
37			#include "cpu_emulation.h"
38			#include "main.h"
39			#include "macos_util.h"
40			#include "prefs.h"
41			#include "user_strings.h"
42			#include "ether.h"
43			#include "ether_defs.h"
44
45	cebix	1.3	#ifndef NO_STD_NAMESPACE
46			using std::map;
47			#endif
48
49	cebix	1.1	#define DEBUG 0
50			#include "debug.h"
51
52			#define MONITOR 0
53
54
55			// Global variables
56			static int fd = -1; // fd of sheep_net device
57			static pthread_t ether_thread; // Packet reception thread
58			static pthread_attr_t ether_thread_attr; // Packet reception thread attributes
59			static bool thread_active = false; // Flag: Packet reception thread installed
60			static sem_t int_ack; // Interrupt acknowledge semaphore
61			static bool is_ethertap; // Flag: Ethernet device is ethertap
62	cebix	1.2	static bool udp_tunnel; // Flag: UDP tunnelling active, fd is the socket descriptor
63	cebix	1.1
64	cebix	1.3	// Attached network protocols, maps protocol type to MacOS handler address
65			static map<uint16, uint32> net_protocols;
66
67	cebix	1.1	// Prototypes
68			static void receive_func(void arg);
69
70
71			/*
72	cebix	1.2	* Start packet reception thread
73			*/
74
75			static bool start_thread(void)
76			{
77			if (sem_init(&int_ack, 0, 0) < 0) {
78			printf("WARNING: Cannot init semaphore");
79			return false;
80			}
81
82			pthread_attr_init(&ether_thread_attr);
83			#if defined(_POSIX_THREAD_PRIORITY_SCHEDULING)
84			if (geteuid() == 0) {
85			pthread_attr_setinheritsched(&ether_thread_attr, PTHREAD_EXPLICIT_SCHED);
86			pthread_attr_setschedpolicy(&ether_thread_attr, SCHED_FIFO);
87			struct sched_param fifo_param;
88			fifo_param.sched_priority = (sched_get_priority_min(SCHED_FIFO) + sched_get_priority_max(SCHED_FIFO)) / 2 + 1;
89			pthread_attr_setschedparam(&ether_thread_attr, &fifo_param);
90			}
91			#endif
92
93			thread_active = (pthread_create(&ether_thread, &ether_thread_attr, receive_func, NULL) == 0);
94			if (!thread_active) {
95			printf("WARNING: Cannot start Ethernet thread");
96			return false;
97			}
98
99			return true;
100			}
101
102
103			/*
104			* Stop packet reception thread
105			*/
106
107			static void stop_thread(void)
108			{
109			if (thread_active) {
110			pthread_cancel(ether_thread);
111			pthread_join(ether_thread, NULL);
112			sem_destroy(&int_ack);
113			thread_active = false;
114			}
115			}
116
117
118			/*
119	cebix	1.1	* Initialization
120			*/
121
122	cebix	1.2	bool ether_init(void)
123	cebix	1.1	{
124			int nonblock = 1;
125			char str[256];
126
127			// Do nothing if no Ethernet device specified
128			const char *name = PrefsFindString("ether");
129			if (name == NULL)
130	cebix	1.2	return false;
131	cebix	1.1
132			// Is it Ethertap?
133			is_ethertap = (strncmp(name, "tap", 3) == 0);
134
135			// Open sheep_net or ethertap device
136			char dev_name[16];
137			if (is_ethertap)
138			sprintf(dev_name, "/dev/%s", name);
139			else
140			strcpy(dev_name, "/dev/sheep_net");
141			fd = open(dev_name, O_RDWR);
142			if (fd < 0) {
143			sprintf(str, GetString(STR_NO_SHEEP_NET_DRIVER_WARN), dev_name, strerror(errno));
144			WarningAlert(str);
145			goto open_error;
146			}
147
148			#if defined(__linux__)
149			// Attach sheep_net to selected Ethernet card
150			if (!is_ethertap && ioctl(fd, SIOCSIFLINK, name) < 0) {
151			sprintf(str, GetString(STR_SHEEP_NET_ATTACH_WARN), strerror(errno));
152			WarningAlert(str);
153			goto open_error;
154			}
155			#endif
156
157			// Set nonblocking I/O
158			ioctl(fd, FIONBIO, &nonblock);
159
160			// Get Ethernet address
161			if (is_ethertap) {
162			pid_t p = getpid(); // If configured for multicast, ethertap requires that the lower 32 bit of the Ethernet address are our PID
163			ether_addr[0] = 0xfe;
164			ether_addr[1] = 0xfd;
165			ether_addr[2] = p >> 24;
166			ether_addr[3] = p >> 16;
167			ether_addr[4] = p >> 8;
168			ether_addr[5] = p;
169			} else
170			ioctl(fd, SIOCGIFADDR, ether_addr);
171			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]));
172
173			// Start packet reception thread
174	cebix	1.2	if (!start_thread())
175	cebix	1.1	goto open_error;
176
177			// Everything OK
178	cebix	1.2	return true;
179	cebix	1.1
180			open_error:
181	cebix	1.2	stop_thread();
182
183	cebix	1.1	if (fd > 0) {
184			close(fd);
185			fd = -1;
186			}
187	cebix	1.2	return false;
188	cebix	1.1	}
189
190
191			/*
192			* Deinitialization
193			*/
194
195	cebix	1.2	void ether_exit(void)
196	cebix	1.1	{
197			// Stop reception thread
198			if (thread_active) {
199			pthread_cancel(ether_thread);
200			pthread_join(ether_thread, NULL);
201			sem_destroy(&int_ack);
202			thread_active = false;
203			}
204
205			// Close sheep_net device
206			if (fd > 0)
207			close(fd);
208			}
209
210
211			/*
212			* Reset
213			*/
214
215	cebix	1.3	void ether_reset(void)
216	cebix	1.1	{
217	cebix	1.3	net_protocols.clear();
218	cebix	1.1	}
219
220
221			/*
222			* Add multicast address
223			*/
224
225			int16 ether_add_multicast(uint32 pb)
226			{
227			if (ioctl(fd, SIOCADDMULTI, Mac2HostAddr(pb + eMultiAddr)) < 0) {
228			D(bug("WARNING: Couldn't enable multicast address\n"));
229			if (is_ethertap)
230			return noErr;
231			else
232			return eMultiErr;
233			} else
234			return noErr;
235			}
236
237
238			/*
239			* Delete multicast address
240			*/
241
242			int16 ether_del_multicast(uint32 pb)
243			{
244			if (ioctl(fd, SIOCDELMULTI, Mac2HostAddr(pb + eMultiAddr)) < 0) {
245			D(bug("WARNING: Couldn't disable multicast address\n"));
246			return eMultiErr;
247			} else
248			return noErr;
249			}
250
251
252			/*
253			* Attach protocol handler
254			*/
255
256			int16 ether_attach_ph(uint16 type, uint32 handler)
257			{
258	cebix	1.3	if (net_protocols.find(type) != net_protocols.end())
259	cebix	1.1	return lapProtErr;
260	cebix	1.3	net_protocols[type] = handler;
261			return noErr;
262	cebix	1.1	}
263
264
265			/*
266			* Detach protocol handler
267			*/
268
269			int16 ether_detach_ph(uint16 type)
270			{
271	cebix	1.3	if (net_protocols.erase(type) == 0)
272	cebix	1.1	return lapProtErr;
273	cebix	1.3	return noErr;
274	cebix	1.1	}
275
276
277			/*
278			* Transmit raw ethernet packet
279			*/
280
281			int16 ether_write(uint32 wds)
282			{
283			// Copy packet to buffer
284			uint8 packet[1516], *p = packet;
285			int len = 0;
286			#if defined(__linux__)
287			if (is_ethertap) {
288			*p++ = 0; // Linux ethertap discards the first 2 bytes
289			*p++ = 0;
290			len += 2;
291			}
292			#endif
293	cebix	1.2	len += ether_wds_to_buffer(wds, p);
294	cebix	1.1
295			#if MONITOR
296			bug("Sending Ethernet packet:\n");
297			for (int i=0; i<len; i++) {
298			bug("%02x ", packet[i]);
299			}
300			bug("\n");
301			#endif
302
303			// Transmit packet
304			if (write(fd, packet, len) < 0) {
305			D(bug("WARNING: Couldn't transmit packet\n"));
306			return excessCollsns;
307			} else
308			return noErr;
309			}
310
311
312			/*
313	cebix	1.2	* Start UDP packet reception thread
314			*/
315
316			bool ether_start_udp_thread(int socket_fd)
317			{
318			fd = socket_fd;
319			udp_tunnel = true;
320			return start_thread();
321			}
322
323
324			/*
325			* Stop UDP packet reception thread
326			*/
327
328			void ether_stop_udp_thread(void)
329			{
330			stop_thread();
331			fd = -1;
332			}
333
334
335			/*
336	cebix	1.1	* Packet reception thread
337			*/
338
339			static void receive_func(void arg)
340			{
341			for (;;) {
342
343			// Wait for packets to arrive
344			struct pollfd pf = {fd, POLLIN, 0};
345			int res = poll(&pf, 1, -1);
346			if (res <= 0)
347			break;
348
349			// Trigger Ethernet interrupt
350			D(bug(" packet received, triggering Ethernet interrupt\n"));
351			SetInterruptFlag(INTFLAG_ETHER);
352			TriggerInterrupt();
353
354			// Wait for interrupt acknowledge by EtherInterrupt()
355			sem_wait(&int_ack);
356			}
357			return NULL;
358			}
359
360
361			/*
362			* Ethernet interrupt - activate deferred tasks to call IODone or protocol handlers
363			*/
364
365			void EtherInterrupt(void)
366			{
367			D(bug("EtherIRQ\n"));
368
369			// Call protocol handler for received packets
370			uint8 packet[1516];
371	cebix	1.2	ssize_t length;
372	cebix	1.1	for (;;) {
373
374	cebix	1.2	if (udp_tunnel) {
375
376			// Read packet from socket
377			struct sockaddr_in from;
378			socklen_t from_len = sizeof(from);
379			length = recvfrom(fd, packet, 1514, 0, (struct sockaddr *)&from, &from_len);
380			if (length < 14)
381			break;
382			ether_udp_read(packet, length, &from);
383
384			} else {
385
386			// Read packet from sheep_net device
387	cebix	1.1	#if defined(__linux__)
388	cebix	1.2	length = read(fd, packet, is_ethertap ? 1516 : 1514);
389	cebix	1.1	#else
390	cebix	1.2	length = read(fd, packet, 1514);
391	cebix	1.1	#endif
392	cebix	1.2	if (length < 14)
393			break;
394	cebix	1.1
395			#if MONITOR
396	cebix	1.2	bug("Receiving Ethernet packet:\n");
397			for (int i=0; i<length; i++) {
398			bug("%02x ", packet[i]);
399			}
400			bug("\n");
401	cebix	1.1	#endif
402
403	cebix	1.2	// Pointer to packet data (Ethernet header)
404			uint8 *p = packet;
405	cebix	1.1	#if defined(__linux__)
406	cebix	1.2	if (is_ethertap) {
407			p += 2; // Linux ethertap has two random bytes before the packet
408			length -= 2;
409			}
410	cebix	1.1	#endif
411
412	cebix	1.2	// Get packet type
413			uint16 type = (p[12] << 8) \| p[13];
414	cebix	1.1
415	cebix	1.2	// Look for protocol
416	cebix	1.3	uint16 search_type = (type <= 1500 ? 0 : type);
417			if (net_protocols.find(search_type) == net_protocols.end())
418	cebix	1.2	continue;
419	cebix	1.3	uint32 handler = net_protocols[search_type];
420	cebix	1.2
421			// No default handler
422	cebix	1.3	if (handler == 0)
423	cebix	1.2	continue;
424
425			// Copy header to RHA
426			Host2Mac_memcpy(ether_data + ed_RHA, p, 14);
427			D(bug(" header %08x%04x %08x%04x %04x\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)));
428
429			// Call protocol handler
430			M68kRegisters r;
431			r.d[0] = type; // Packet type
432			r.d[1] = length - 14; // Remaining packet length (without header, for ReadPacket)
433			r.a[0] = (uint32)p + 14; // Pointer to packet (host address, for ReadPacket)
434			r.a[3] = ether_data + ed_RHA + 14; // Pointer behind header in RHA
435			r.a[4] = ether_data + ed_ReadPacket; // Pointer to ReadPacket/ReadRest routines
436	cebix	1.3	D(bug(" calling protocol handler %08x, type %08x, length %08x, data %08x, rha %08x, read_packet %08x\n", handler, r.d[0], r.d[1], r.a[0], r.a[3], r.a[4]));
437			Execute68k(handler, &r);
438	cebix	1.2	}
439	cebix	1.1	}
440
441			// Acknowledge interrupt to reception thread
442			D(bug(" EtherIRQ done\n"));
443			sem_post(&int_ack);
444			}