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>

#include <netinet/in.h>
#include <sys/socket.h>

#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"

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

// 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;
}


/*
 *  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);

        // 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
        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
                        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 %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", 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:	1.2
Committed:	2001-07-12T19:48:27Z (23 years, 4 months ago) by cebix
Branch:	MAIN
Changes since 1.1:	+137 -79 lines
Log Message:	- Implemented AppleTalk-over-UDP tunnelling, activated by setting "udptunnel" to "true". This uses the BSD socket API, so it's fairly portable (currently only imeplemented under Unix, though). This works by sending raw Ethernet packets as UDP packets to a fixed port number ("udpport", default is 6066), using IP broadcasts to simulate Ethernet broad- and multicasts. Currently only tested with AppleTalk.
#	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			#include <pthread.h>
26			#include <semaphore.h>
27			#include <errno.h>
28			#include <stdio.h>
29
30	cebix	1.2	#include <netinet/in.h>
31			#include <sys/socket.h>
32
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			#define DEBUG 0
46			#include "debug.h"
47
48			#define MONITOR 0
49
50
51			// List of attached protocols
52			struct NetProtocol {
53			NetProtocol *next;
54			uint16 type;
55			uint32 handler;
56			};
57
58			static NetProtocol *prot_list = NULL;
59
60
61			// Global variables
62			static int fd = -1; // fd of sheep_net device
63			static pthread_t ether_thread; // Packet reception thread
64			static pthread_attr_t ether_thread_attr; // Packet reception thread attributes
65			static bool thread_active = false; // Flag: Packet reception thread installed
66			static sem_t int_ack; // Interrupt acknowledge semaphore
67			static bool is_ethertap; // Flag: Ethernet device is ethertap
68	cebix	1.2	static bool udp_tunnel; // Flag: UDP tunnelling active, fd is the socket descriptor
69	cebix	1.1
70			// Prototypes
71			static void receive_func(void arg);
72
73
74			/*
75			* Find protocol in list
76			*/
77
78			static NetProtocol *find_protocol(uint16 type)
79			{
80			// All 802.2 types are the same
81			if (type <= 1500)
82			type = 0;
83
84			// Search list (we could use hashing here but there are usually only three
85			// handlers installed: 0x0000 for AppleTalk and 0x0800/0x0806 for TCP/IP)
86			NetProtocol *p = prot_list;
87			while (p) {
88			if (p->type == type)
89			return p;
90			p = p->next;
91			}
92			return NULL;
93			}
94
95
96			/*
97			* Remove all protocols
98			*/
99
100			static void remove_all_protocols(void)
101			{
102			NetProtocol *p = prot_list;
103			while (p) {
104			NetProtocol *next = p->next;
105			delete p;
106			p = next;
107			}
108			prot_list = NULL;
109			}
110
111
112			/*
113	cebix	1.2	* Start packet reception thread
114			*/
115
116			static bool start_thread(void)
117			{
118			if (sem_init(&int_ack, 0, 0) < 0) {
119			printf("WARNING: Cannot init semaphore");
120			return false;
121			}
122
123			pthread_attr_init(&ether_thread_attr);
124			#if defined(_POSIX_THREAD_PRIORITY_SCHEDULING)
125			if (geteuid() == 0) {
126			pthread_attr_setinheritsched(&ether_thread_attr, PTHREAD_EXPLICIT_SCHED);
127			pthread_attr_setschedpolicy(&ether_thread_attr, SCHED_FIFO);
128			struct sched_param fifo_param;
129			fifo_param.sched_priority = (sched_get_priority_min(SCHED_FIFO) + sched_get_priority_max(SCHED_FIFO)) / 2 + 1;
130			pthread_attr_setschedparam(&ether_thread_attr, &fifo_param);
131			}
132			#endif
133
134			thread_active = (pthread_create(&ether_thread, &ether_thread_attr, receive_func, NULL) == 0);
135			if (!thread_active) {
136			printf("WARNING: Cannot start Ethernet thread");
137			return false;
138			}
139
140			return true;
141			}
142
143
144			/*
145			* Stop packet reception thread
146			*/
147
148			static void stop_thread(void)
149			{
150			if (thread_active) {
151			pthread_cancel(ether_thread);
152			pthread_join(ether_thread, NULL);
153			sem_destroy(&int_ack);
154			thread_active = false;
155			}
156			}
157
158
159			/*
160	cebix	1.1	* Initialization
161			*/
162
163	cebix	1.2	bool ether_init(void)
164	cebix	1.1	{
165			int nonblock = 1;
166			char str[256];
167
168			// Do nothing if no Ethernet device specified
169			const char *name = PrefsFindString("ether");
170			if (name == NULL)
171	cebix	1.2	return false;
172	cebix	1.1
173			// Is it Ethertap?
174			is_ethertap = (strncmp(name, "tap", 3) == 0);
175
176			// Open sheep_net or ethertap device
177			char dev_name[16];
178			if (is_ethertap)
179			sprintf(dev_name, "/dev/%s", name);
180			else
181			strcpy(dev_name, "/dev/sheep_net");
182			fd = open(dev_name, O_RDWR);
183			if (fd < 0) {
184			sprintf(str, GetString(STR_NO_SHEEP_NET_DRIVER_WARN), dev_name, strerror(errno));
185			WarningAlert(str);
186			goto open_error;
187			}
188
189			#if defined(__linux__)
190			// Attach sheep_net to selected Ethernet card
191			if (!is_ethertap && ioctl(fd, SIOCSIFLINK, name) < 0) {
192			sprintf(str, GetString(STR_SHEEP_NET_ATTACH_WARN), strerror(errno));
193			WarningAlert(str);
194			goto open_error;
195			}
196			#endif
197
198			// Set nonblocking I/O
199			ioctl(fd, FIONBIO, &nonblock);
200
201			// Get Ethernet address
202			if (is_ethertap) {
203			pid_t p = getpid(); // If configured for multicast, ethertap requires that the lower 32 bit of the Ethernet address are our PID
204			ether_addr[0] = 0xfe;
205			ether_addr[1] = 0xfd;
206			ether_addr[2] = p >> 24;
207			ether_addr[3] = p >> 16;
208			ether_addr[4] = p >> 8;
209			ether_addr[5] = p;
210			} else
211			ioctl(fd, SIOCGIFADDR, ether_addr);
212			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]));
213
214			// Start packet reception thread
215	cebix	1.2	if (!start_thread())
216	cebix	1.1	goto open_error;
217
218			// Everything OK
219	cebix	1.2	return true;
220	cebix	1.1
221			open_error:
222	cebix	1.2	stop_thread();
223
224	cebix	1.1	if (fd > 0) {
225			close(fd);
226			fd = -1;
227			}
228	cebix	1.2	return false;
229	cebix	1.1	}
230
231
232			/*
233			* Deinitialization
234			*/
235
236	cebix	1.2	void ether_exit(void)
237	cebix	1.1	{
238			// Stop reception thread
239			if (thread_active) {
240			pthread_cancel(ether_thread);
241			pthread_join(ether_thread, NULL);
242			sem_destroy(&int_ack);
243			thread_active = false;
244			}
245
246			// Close sheep_net device
247			if (fd > 0)
248			close(fd);
249
250			// Remove all protocols
251			remove_all_protocols();
252			}
253
254
255			/*
256			* Reset
257			*/
258
259			void EtherReset(void)
260			{
261			remove_all_protocols();
262			}
263
264
265			/*
266			* Add multicast address
267			*/
268
269			int16 ether_add_multicast(uint32 pb)
270			{
271			if (ioctl(fd, SIOCADDMULTI, Mac2HostAddr(pb + eMultiAddr)) < 0) {
272			D(bug("WARNING: Couldn't enable multicast address\n"));
273			if (is_ethertap)
274			return noErr;
275			else
276			return eMultiErr;
277			} else
278			return noErr;
279			}
280
281
282			/*
283			* Delete multicast address
284			*/
285
286			int16 ether_del_multicast(uint32 pb)
287			{
288			if (ioctl(fd, SIOCDELMULTI, Mac2HostAddr(pb + eMultiAddr)) < 0) {
289			D(bug("WARNING: Couldn't disable multicast address\n"));
290			return eMultiErr;
291			} else
292			return noErr;
293			}
294
295
296			/*
297			* Attach protocol handler
298			*/
299
300			int16 ether_attach_ph(uint16 type, uint32 handler)
301			{
302			// Already attached?
303			NetProtocol *p = find_protocol(type);
304			if (p != NULL)
305			return lapProtErr;
306			else {
307			// No, create and attach
308			p = new NetProtocol;
309			p->next = prot_list;
310			p->type = type;
311			p->handler = handler;
312			prot_list = p;
313			return noErr;
314			}
315			}
316
317
318			/*
319			* Detach protocol handler
320			*/
321
322			int16 ether_detach_ph(uint16 type)
323			{
324			NetProtocol *p = find_protocol(type);
325			if (p != NULL) {
326			NetProtocol *q = prot_list;
327			if (p == q) {
328			prot_list = p->next;
329			delete p;
330			return noErr;
331			}
332			while (q) {
333			if (q->next == p) {
334			q->next = p->next;
335			delete p;
336			return noErr;
337			}
338			q = q->next;
339			}
340			return lapProtErr;
341			} else
342			return lapProtErr;
343			}
344
345
346			/*
347			* Transmit raw ethernet packet
348			*/
349
350			int16 ether_write(uint32 wds)
351			{
352			// Set source address
353			uint32 hdr = ReadMacInt32(wds + 2);
354			Host2Mac_memcpy(hdr + 6, ether_addr, 6);
355
356			// Copy packet to buffer
357			uint8 packet[1516], *p = packet;
358			int len = 0;
359			#if defined(__linux__)
360			if (is_ethertap) {
361			*p++ = 0; // Linux ethertap discards the first 2 bytes
362			*p++ = 0;
363			len += 2;
364			}
365			#endif
366	cebix	1.2	len += ether_wds_to_buffer(wds, p);
367	cebix	1.1
368			#if MONITOR
369			bug("Sending Ethernet packet:\n");
370			for (int i=0; i<len; i++) {
371			bug("%02x ", packet[i]);
372			}
373			bug("\n");
374			#endif
375
376			// Transmit packet
377			if (write(fd, packet, len) < 0) {
378			D(bug("WARNING: Couldn't transmit packet\n"));
379			return excessCollsns;
380			} else
381			return noErr;
382			}
383
384
385			/*
386	cebix	1.2	* Start UDP packet reception thread
387			*/
388
389			bool ether_start_udp_thread(int socket_fd)
390			{
391			fd = socket_fd;
392			udp_tunnel = true;
393			return start_thread();
394			}
395
396
397			/*
398			* Stop UDP packet reception thread
399			*/
400
401			void ether_stop_udp_thread(void)
402			{
403			stop_thread();
404			fd = -1;
405			}
406
407
408			/*
409	cebix	1.1	* Packet reception thread
410			*/
411
412			static void receive_func(void arg)
413			{
414			for (;;) {
415
416			// Wait for packets to arrive
417			struct pollfd pf = {fd, POLLIN, 0};
418			int res = poll(&pf, 1, -1);
419			if (res <= 0)
420			break;
421
422			// Trigger Ethernet interrupt
423			D(bug(" packet received, triggering Ethernet interrupt\n"));
424			SetInterruptFlag(INTFLAG_ETHER);
425			TriggerInterrupt();
426
427			// Wait for interrupt acknowledge by EtherInterrupt()
428			sem_wait(&int_ack);
429			}
430			return NULL;
431			}
432
433
434			/*
435			* Ethernet interrupt - activate deferred tasks to call IODone or protocol handlers
436			*/
437
438			void EtherInterrupt(void)
439			{
440			D(bug("EtherIRQ\n"));
441
442			// Call protocol handler for received packets
443			uint8 packet[1516];
444	cebix	1.2	ssize_t length;
445	cebix	1.1	for (;;) {
446
447	cebix	1.2	if (udp_tunnel) {
448
449			// Read packet from socket
450			struct sockaddr_in from;
451			socklen_t from_len = sizeof(from);
452			length = recvfrom(fd, packet, 1514, 0, (struct sockaddr *)&from, &from_len);
453			if (length < 14)
454			break;
455			ether_udp_read(packet, length, &from);
456
457			} else {
458
459			// Read packet from sheep_net device
460	cebix	1.1	#if defined(__linux__)
461	cebix	1.2	length = read(fd, packet, is_ethertap ? 1516 : 1514);
462	cebix	1.1	#else
463	cebix	1.2	length = read(fd, packet, 1514);
464	cebix	1.1	#endif
465	cebix	1.2	if (length < 14)
466			break;
467	cebix	1.1
468			#if MONITOR
469	cebix	1.2	bug("Receiving Ethernet packet:\n");
470			for (int i=0; i<length; i++) {
471			bug("%02x ", packet[i]);
472			}
473			bug("\n");
474	cebix	1.1	#endif
475
476	cebix	1.2	// Pointer to packet data (Ethernet header)
477			uint8 *p = packet;
478	cebix	1.1	#if defined(__linux__)
479	cebix	1.2	if (is_ethertap) {
480			p += 2; // Linux ethertap has two random bytes before the packet
481			length -= 2;
482			}
483	cebix	1.1	#endif
484
485	cebix	1.2	// Get packet type
486			uint16 type = (p[12] << 8) \| p[13];
487	cebix	1.1
488	cebix	1.2	// Look for protocol
489			NetProtocol *prot = find_protocol(type);
490			if (prot == NULL)
491			continue;
492
493			// No default handler
494			if (prot->handler == 0)
495			continue;
496
497			// Copy header to RHA
498			Host2Mac_memcpy(ether_data + ed_RHA, p, 14);
499			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)));
500
501			// Call protocol handler
502			M68kRegisters r;
503			r.d[0] = type; // Packet type
504			r.d[1] = length - 14; // Remaining packet length (without header, for ReadPacket)
505			r.a[0] = (uint32)p + 14; // Pointer to packet (host address, for ReadPacket)
506			r.a[3] = ether_data + ed_RHA + 14; // Pointer behind header in RHA
507			r.a[4] = ether_data + ed_ReadPacket; // Pointer to ReadPacket/ReadRest routines
508			D(bug(" calling protocol handler %08x, type %08x, length %08x, data %08x, rha %08x, read_packet %08x\n", prot->handler, r.d[0], r.d[1], r.a[0], r.a[3], r.a[4]));
509			Execute68k(prot->handler, &r);
510			}
511	cebix	1.1	}
512
513			// Acknowledge interrupt to reception thread
514			D(bug(" EtherIRQ done\n"));
515			sem_post(&int_ack);
516			}