This patch switches the MINIX3 ethernet driver stack from a port-based

model to an instance-based model. Each ethernet driver instance is now
responsible for exactly one network interface card. The port field in
/etc/inet.conf now acts as an instance field instead.

This patch also updates the data link protocol. This update:
- eliminates the concept of ports entirely;
- eliminates DL_GETNAME entirely;
- standardizes on using m_source for IPC and DL_ENDPT for safecopies;
- removes error codes from TASK/STAT replies, as they were unused;
- removes a number of other old or unused fields;
- names and renames a few other fields.

All ethernet drivers have been changed to:
- conform to the new protocol, and exactly that;
- take on an instance number based on a given "instance" argument;
- skip that number of PCI devices in probe iterations;
- use config tables and environment variables based on that number;
- no longer be limited to a predefined maximum of cards in any way;
- get rid of any leftover non-safecopy support and other ancient junk;
- have a correct banner protocol figure, or none at all.

Other changes:
* Inet.conf is now taken to be line-based, and supports #-comments.
  No existing installations are expected to be affected by this.
* A new, select-based asynchio library replaces the old one.
  Kindly contributed by Kees J. Bot.
* Inet now supports use of select() on IP devices.
  Combined, the last two changes together speed up dhcpd
  considerably in the presence of multiple interfaces.
* A small bug has been fixed in nonamed.

include/sys/asynchio.h

@@ -1,38 +1,42 @@
 /*	asynchio.h - Asynchronous I/O			Author: Kees J. Bot
- *								26 Jan 1995
- * This is just a fake async I/O library to be used for programs
- * written for Minix-vmd that must also run under standard Minix.
- * This limits the number of ugly #ifdefs somewhat.  The programs must
- * be restricted to performing just one service, of course.
+ *								7 Jul 1997
+ * Minix-vmd compatible asynchio(3) using BSD select(2).
  */
 #ifndef _SYS__ASYNCHIO_H
 #define _SYS__ASYNCHIO_H
 
-#ifndef _ANSI_H
-#include <ansi.h>
-#endif
+#include <sys/select.h>			/* for FD_SETSIZE */
 
-#include <sys/time.h>
+#define SEL_READ	0		/* Code for a read. */
+#define SEL_WRITE	1		/* Code for a write. */
+#define SEL_EXCEPT	2		/* Code for some exception. */
+#define SEL_NR		3		/* Number of codes. */
+
+struct _asynfd {
+	int		afd_seen;	/* Set if we manage this descriptor. */
+	int		afd_flags;	/* File flags by fcntl(fd, F_GETFL). */
+	int		afd_state[SEL_NR];  /* Operation state. */
+};
 
 typedef struct {
-	char	state;
-	char	op;
-	char	fd;
-	char	req;
-	void	*data;
-	ssize_t	count;
-	int	errno;
+	int		asyn_more;	/* Set if more to do before blocking. */
+	struct _asynfd	asyn_afd[FD_SETSIZE];
+	fd_set		asyn_fdset[SEL_NR];	/* Select() fd sets. */
 } asynchio_t;
 
-#define ASYN_NONBLOCK	0x01
+#define ASYN_INPROGRESS	EAGAIN		/* Errno code telling "nothing yet." */
+#define ASYN_NONBLOCK	0x01		/* If asyn_wait() mustn't block. */
 
-#define ASYN_INPROGRESS	EINPROGRESS
+struct timeval;
 
 void asyn_init(asynchio_t *_asyn);
 ssize_t asyn_read(asynchio_t *_asyn, int _fd, void *_buf, size_t _len);
 ssize_t asyn_write(asynchio_t *_asyn, int _fd, const void *_buf, size_t _len);
-int asyn_ioctl(asynchio_t *_asyn, int _fd, unsigned long _request, void *_data);
+int asyn_special(asynchio_t *_asyn, int _fd, int _op);
+int asyn_result(asynchio_t *_asyn, int _fd, int _op, int _result);
 int asyn_wait(asynchio_t *_asyn, int _flags, struct timeval *to);
+int asyn_cancel(asynchio_t *_asyn, int _fd, int _op);
+int asyn_pending(asynchio_t *_asyn, int _fd, int _op);
 int asyn_synch(asynchio_t *_asyn, int _fd);
 int asyn_close(asynchio_t *_asyn, int _fd);